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  • 1
    Electronic Resource
    Electronic Resource
    Characterization of B-cell lines from SLE patients and their relatives (1995)
    Springer
    Rheumatology international 15 (1995), S. 89-93 
    Details
    ISSN: 1437-160X
    Keywords: SLE Lupus ; BBV transformation ; Genetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Epstein-Barr-virus (EBV)-transformed lymphoblastoid B-cell lines were generated from peripheral blood lymphocytes of 55 patients with systemic lupus erythematosus (SLE) and 44 healthy relatives. All donors have previously been extensively characterized with regard to clinical, serologic, and genetic parameters. Here, peripheral blood lymphocytes and lines were characterized for cell surface antigens. Furthermore, autoantibody production and proliferation rate of the cell lines were monitored. A significant difference between patients and relatives was the lower proliferation rate of EBV-transformed cell lines of the SLE patients. All SLE cell lines are available for interested researches and can be obtained from the European Cell Bank, Salisbury, UK.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00302123
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  • 2
    Electronic Resource
    Electronic Resource
    Ultrastructural alterations and environmental exposure influence the opiate concentrations in hair of drug addicts (1995)
    Springer
    International journal of legal medicine 107 (1995), S. 301-305 
    Details
    ISSN: 1437-1596
    Keywords: Hair ; Opiates ; Drug monitoring ; Ultrastructure ; Environmental conditions ; Hair damage Cosmetic treatment
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine , Law
    Notes: Abstract Hair samples were taken at autopsy from the head of 1 male and 1 female subject both known as drug abusers. Some of the strands were bleached by in-vitro cosmetic treatment. The bleached hair as well as the original hair samples were partly exposed to water or soil prior to further investigations and drug monitoring. The exposure times were 4 weeks or 6 months for water and 6 months for soil. The hair fibers were examined by transmission electron microscope (TEM) and by scanning electron microscope (SEM) investigations. The electron microscope studies confirmed that all experimental conditions had produced morphological alterations in the hair fibers. After exposure to water or to soil for 6 months as well as after storage of the clipped bleached hair in tap water at room temperature for 4 weeks, drug monitoring of formerly positive hair samples gave negative results. After storage of natural hair in soil or in water for 4 weeks the opiate levels had dramatically decreased. The samples were screened by fluorescence polarization immunoassay after enzymatic digestion. The results were confirmed by GC/MS.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01246877
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  • 3
    Electronic Resource
    Electronic Resource
    Genetic mapping of adrenergic receptor genes in humans (1995)
    Springer
    Journal of molecular medicine 73 (1995), S. 299-306 
    Details
    ISSN: 1432-1440
    Keywords: Adrenergic receptors ; Human genetics ; Restriction fragment length polymorphism ; Chromosome mapping ; Linkage ; Genetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract We have genetically mapped the genes encoding four human adrenergic receptors (ARs) of subtypes α1C, α2A, α2B, and β1, which are prototypic G protein coupled receptors that mediate the physiological effects of neurotransmitters, hormones, and drugs. We placed these genes onto the Cooperative Human Linkage Center (CHLC) and Genethon framework maps, within confidence intervals with greater than 1000∶1 odds. With multipoint analysis the α1C gene (locus ADRA1C) mapped to the interval between NEFL and D8S283; α2-C4, the gene encoding the α2C AR (locus ADRA2C), mapped to the interval between D4S126 and D4S62; and the α2-C10 (α2A AR)/β1 haplotype (loci ADRA2A/ ADRB1) mapped to the interval between D10S259 and D10S187. A fifth AR gene, β2, yielded significant LOD scores with markers on the long arm of chromosome 5; however, this locus (ADRB2) could not be mapped to any specific interval with odds of greater than 1000∶1. The two AR genes that are completely linked, α2-C10 and β1, were oriented on their shared 225-kb genomic fragment relative to the direction of transcription, with β1 being 5′ to α2-C10. The positioning of these genes on high-density framework maps allows them to be tested as candidates in a spectrum of diseases that might involve AR dysfunction.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00231616
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  • 4
    Electronic Resource
    Electronic Resource
    Insertion/deletion polymorphism in the angiotensin-converting enzyme gene associated with macroangiopathy and blood pressure in patients with non-insulin-dependent diabetes mellitus (1995)
    Springer
    Journal of molecular medicine 73 (1995), S. 307-311 
    Details
    ISSN: 1432-1440
    Keywords: Atherosclerosis ; Hypertension ; Type 2 diabetes ; Genetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract In the search for new risk factors for diabetic macroangiopathy the insertion/deletion (I/D) polymorphism in the angiotensin-converting enzyme gene was studied in 237 consecutive patients (125 men and 112 women) with non-insulin-dependent diabetes. The female population showed an excess of ischemic electro-cardiographic changes or definite myocardial infarctions in the patients homozygous for the deletion [D/D; odds ratio (OR) 2.8; 95% confidence interval (CI) 1.4–5.3] and in the insertion/deletion heterozygotes (I/D; OR 1.8; CI 1.1–3.1) compared with the patients homozygous for the insertion (I/I). In the total series coronary heart disease, cerebrovascular disease, and claudication were more often observed in the patients with I/D (OR 1.5; CI 1.0–2.2) or the D/D genotype patients (OR 1.7; CI 1.1–2.6) than in those with the genotype I/I. The systolic blood pressure was lower in patients with genotype I/I (138±19 mmHg) than in those with the genotype I/D (149±22 mmHg) or D/D (150±21 mmHg; P〈0.02). The prevalence of hypertension and the median urinary albumin excretion rate also tended to be lowest in the I/I genotype patients. Multiple logistic analysis revealed that in women the angiotensin-converting enzyme D/D genotype is independently associated with coronary heart disease. Our findings suggest that variation at the angiotensin-converting enzyme gene locus is one of the factors involved in the predisposition of diabetic patients to the development of arterial disease and hypertension.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00231617
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  • 5
    Electronic Resource
    Electronic Resource
    A histological study on experimental autoimmune myocarditis with special reference to initiation of the disease and cardiac dendritic cells (1995)
    Springer
    Virchows Archiv 426 (1995), S. 493-500 
    Details
    ISSN: 1432-2307
    Keywords: Autoimmune myocarditis ; Cardiac myosin ; Dendritic cell ; Macrophage ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The precise mechanism of myosin-induced autoimmune myocarditis is unknown. The purpose of the present study was to define the immunohistological and ultrastructural characteristics of the infiltrating cells, especially in the initial phase of the myocarditis. It was demonstrated that OX6-positive dendritic cells first infiltrated the cardiocytes on day 13 after immunization. After day 17, OX6-positive cells, which possessed elongated irregular-shaped processes on the cell surface but contained few phago-lysosomes in the cytoplasm, were located at the margin of an inflammatory field and inserted their processes into the sarcoplasm of cardiocytes. The central portion of the inflammatory field was occupied by ED1-positive inflammatory macrophages, which were rich in phagosomes and which were in contact with degenerating cardiocytes. No evidence was obtained which suggested that lymphocytes directly injured the cardiocytes. These results demonstrated ultrastructural evidence that the type of infiltrating cell that first injures cardiocytes is the cardiac dendritic cell. Inflammatory macrophages thereafter serve as scavengers of degenerating cardiocytes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00193173
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  • 6
    Electronic Resource
    Electronic Resource
    Ultrastructure and immunoreactivity of dystrophic axons indicate a different pathogenesis of Hallervorden-Spatz disease and infantile neuroaxonal dystrophy (1995)
    Springer
    Virchows Archiv 427 (1995), S. 415-421 
    Details
    ISSN: 1432-2307
    Keywords: Hallervorden-Spatz disease ; Infantile neuroaxonal dystrophy ; Axonal dystrophy ; Ultrastructure ; Cytoskeletal proteins
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract An immunohistochemical and ultrastructural analysis of dystrophic axons (DAs) in the brain and peripheral nerve of a patient with familial infantile neuroaxonal dystrophy (INAD) and in the brain of a patient with familial Hallervorden-Spatz Disease (HSD) revealed prevalent membrano-tubular or granulo-vesicular profiles with a graded pattern of evolution in INAD, while dense bodies, vesicles and amorphous material were pressent in HSD. DAs immunoreactivity with τ-protein and 200 kDa-neurofilament antibodies was stronger in HSD than in INAD. In both cases immunohistochemistry was positive for ubiquitin and negative for β-tubulin and β-amyloid. Distinct ultrastructural features and immunoreactivity pattern of cytoskeletal components suggest different pathogenetic mechanisms.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00199391
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  • 7
    Electronic Resource
    Electronic Resource
    Gastrointestinal autonomic nerve tumours and their separation from other gastrointestinal stromal tumours: an ultrastructural and immunohistochemical study of seven cases (1995)
    Springer
    Virchows Archiv 426 (1995), S. 27-35 
    Details
    ISSN: 1432-2307
    Keywords: Gastrointestinal autonomic nerve tumours ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Gastrointestinal stromal tumours (GIST) represent a heterogeneous group whose classification frequently requires ultrastructural and immunohistochemical studies. In a retrospective study of the ultrastructural findings of 24 gastrointestinal stromal tumours, whose light microscopic study has yielded ambiguous results and in which accurate diagnosis had required ultrastructural support, seven were found to have the characteristics of gastrointestinal autonomic nerve (GAN) tumours. In all of them the diagnosis was based on the presence of dendritic processes with dense neuroendocrine granules. Immunohistochemically, the seven tumours were negative for smooth-muscle markers. All stained positively for vimentin. NSE, chromogranin, and synaptophysin were positive in most of them, while S-100 protein was positive only in two cases. We present the ultrastructural and immunohistochemical features of seven GANT against the background of the GISTs of our series. We conclude that GAN tumours cannot be diagnosed by light microscopy alone but this tumour group displays characteristic electron microscopic and immunohistochemical features and appears to represent a distinct type of GIST.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00194695
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  • 8
    Electronic Resource
    Electronic Resource
    Immunogold labelling of paired helical filaments and amyloid fibrils by specific monoclonal and polyclonal antibodies (1995)
    Springer
    Acta neuropathologica 90 (1995), S. 441-447 
    Details
    ISSN: 1432-0533
    Keywords: Key words Alzheimer's disease ; Neurofibrillary ; tangles ; Amyloid ; Ultrastructure ; Immunohistochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Senile plaque and paired helical filament (PHF) formation are characteristic of Alzheimer's disease, but the mechanisms leading to these lesions still remain unclear. To understand them better, we have performed different immunolabellings of amyloid protein and PHF. We describe a very specific immunodetection of PHF with AD2, a monoclonal antibody directed against a hyperphosphorylated epitope of PHF-tau, and use double immunolabelling to show that PHF and plaque amyloid are discretely labelled by different antibodies. We also discuss different mechanisms of PHF maturation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00294803
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  • 9
    Electronic Resource
    Electronic Resource
    Familial amyloid polyneuropathy associated with transthyretin Gly42 mutation: a quantitative light and electron microscopic study of the peripheral nervous system (1995)
    Springer
    Acta neuropathologica 90 (1995), S. 516-525 
    Details
    ISSN: 1432-0533
    Keywords: Key words Familial amyloid polyneuropathy ; Transthyretin ; Ultrastructure ; Lectin histochemistry ; Morphometry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract We performed extensive quantitative analyses of the peripheral nervous system (PNS) of two siblings with familial amyloid polyneuropathy (FAP) caused by a transthyretin (TTR) Gly42 mutation. Pronounced amyloid deposition was found in the sympathetic ganglia (SyG), dorsal root ganglia (DRG) and throughout the length of the peripheral nerve fibers with some accentuation in the more proximal portion. There was severe neuronal loss in the SyG and DRG together with nerve fiber depletion in the nerve trunk, while only a small amount of amyloid deposition with mild fiber loss was seen in the spinal roots. Sprouts of regenerating axons were very scanty even in the spinal nerves or roots. A teased fiber study mainly showed demyelinating fibers, but axonal degeneration was also present throughout peripheral nerves. An electron microscopic study showed fine amyloid fibrils in direct contact with the axoplasmic membrane of demyelinated axons and destruction of axons in some areas. Amyloid deposition within the PNS in this type of FAP resembled that in type I FAP (TTR Met30). However, direct axonal damage by amyloid fibrils appeared to be more prominent in our cases than in type I FAP. Lectin histochemistry using Ulex europaeus agglutinin I demonstrated preferential depletion of small neurons in the DRG and their primary afferent fibers in the spinal dorsal horn. Primary axonal degeneration and ganglionopathy due to amyloid deposition appear to be the pathogenetic mechanisms for peripheral neuropathy in this type of FAP.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00294814
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  • 10
    Electronic Resource
    Electronic Resource
    A monoclonal antibody that recognizes a carbohydrate epitope of human protoplasmic astrocytes (1995)
    Springer
    Acta neuropathologica 91 (1995), S. 23-30 
    Details
    ISSN: 1432-0533
    Keywords: Key words Protoplasmic astrocyte ; Secondary ; lysosome ; Immunohistochemistry ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract By hybridizing mouse myeloma cells with spleen cells from a BALB/c mouse immunized with the glial cell-rich fraction prepared from an autopsied human brain, we established a hybridoma that produces a monoclonal antibody to protoplasmic astrocytes (PA). The antibody, named PRAS-1, consistently labeled cytoplasm of PA with a granular pattern. In a few cases, the cytoplasmic processes of several astrocytes in gray and white matter were also stained. The immunoreactivity was lost after periodic acid treatment or methylation, showing that the epitope is composed of a carbohydrate. The cytoplasmic reaction was resistant to protease digestion and lost after incubation in an organic solvent, suggesting that a glycolipid is the antigen. On the other hand, the reaction in the processes disappeared upon protease digestion. Ultrastructurally, the immunoreaction was localized to secondary lysosomes. Cross-reactivity was noted on a small number of incidental neurons, corpora amylacea, hepatocytes and esophageal epithelial cells. A long period of formalin fixation did not deteriorate the antigenicity. PRAS-1 was demonstrated to detect PA immunohistochemically on paraffin sections, and may be applicable to further investigations into development or neoplasms of human astrocytes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004010050388
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  • 11
    Electronic Resource
    Electronic Resource
    Familial amyloid polyneuropathy associated with transthyretin Gly42 mutation: a quantitative light and electron microscopic study of the peripheral nervous system (1995)
    Springer
    Acta neuropathologica 90 (1995), S. 516-525 
    Details
    ISSN: 1432-0533
    Keywords: Familial amyloid polyneuropathy ; Transthyretin ; Ultrastructure ; Lectin histochemistry ; Morphometry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract We performed extensive quantitative analyses of the peripheral nervous system (PNS) of two siblings with familial amyloid polyneuropathy (FAP) caused by a transthyretin (TTR) Gly42 mutation. Pronounced amyloid deposition was found in the sympathetic ganglia (SyG), dorsal root ganglia (DRG) and throughout the length of the peripheral nerve fibers with some accentuation in the more proximal portion. There was severe neuronal loss in the SyG and DRG together with nerve fiber depletion in the nerve trunk, while only a small amount of amyloid deposition with mild fiber loss was seen in the spinal roots. Sprouts of regenerating axons were very scanty even in the spinal nerves or roots. A teased fiber study mainly showed demyelinating fibers, but axonal degeneration was also present throughout peripheral nerves. An electron microscopic study showed fine amyloid fibrils in direct contact with the axoplasmic membrane of demyelinated axons and destruction of axons in some areas. Amyloid deposition within the PNS in this type of FAP resembled that in type I FAP (TTR Met30). However, direct axonal damage by amyloid fibrils appeared to be more prominent in our cases than in type I FAP. Lectin histochemistry using Ulex europaeus agglutinin I demonstrated preferential depletion of small neurons in the DRG and their primary afferent fibers in the spinal dorsal horn. Primary axonal degeneration and ganglionopathy due to amyloid deposition appear to be the pathogenetic mechanisms for peripheral neuropathy in this type of FAP.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00294814
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  • 12
    Electronic Resource
    Electronic Resource
    Apoptotic process of cerebellar degeneration in experimental methylmercury intoxication of rats (1995)
    Springer
    Acta neuropathologica 91 (1995), S. 72-77 
    Details
    ISSN: 1432-0533
    Keywords: Key words Cerebellar degeneration ; Methylmercury ; intoxication ; Apoptosis ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract This report deals with the mechanism involved in the cerebellar degeneration following experimental methylmercury poisoning of male Wistar rats. The cerebellar granule cells of animals that exhibited typical hind leg paresis were shrunken and displayed marked nuclear pyknosis. At the ultrastructural level, the nuclei of these cells were condensed and fragmented, features which are characteristic of apoptosis. In situ staining for DNA strand breaks revealed that the pyknotic nuclei were positively labeled. DNA fragmentation was confirmed by agarose gel electrophoresis; a ladder pattern of multiples of approximately 200-base pair fragments, typical of apoptosis, was observed with the cerebellar DNA of the methylmercury-treated animals. These observations suggest that the degeneration of cerebellar granule cells by alkyl mercury compounds involves an apoptotic process.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004010050394
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  • 13
    Electronic Resource
    Electronic Resource
    Mixed desmoplastic primitive neuroepithelial tumor of infancy: a light microscopic, immunocytochemical, ultrastructural and genetic study (1995)
    Springer
    Acta neuropathologica 89 (1995), S. 99-104 
    Details
    ISSN: 1432-0533
    Keywords: Primitive neuroepithelial tumor ; Desmoplastic small cell tumor ; Brain tumor of infancy Immunocytochemistry ; Genetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract We describe a case of a desmoplastic brain tumor which was initially resected from the right fronto-temporal region in a 2 year-old boy. This nodular, calcified tumor was vascularized by the internal carotid artery and the middle meningeal artery branches. Grossly, it contained several mucoid cysts. Light microscopy showed cords or nests of small cuboidal cells surrounded by a loose connective tissue and desmoplasic areas containing fibers and spindle cells. The cuboidal cells expressed epithelial, neuronal and neuroendocrine markers. Some foci of spindle cells showed glial differentiation. The tumor recurred 16 months later and displayed some characteristics of the small cell neuroepithelial component, mitoses being conspicuous. Electron microscopy revealed undifferentiated clear cells, some containing neurosecretory granules. Karyotyping demonstrated the following formula: 〈 15 〉 46, t(8;11) (a13; q11). The chromosome 11 breakpoint was different from that described in Ewing's sarcoma. This isolated translocation has not been previously reported to our knowledge. These unusual features lead us to report this case and to discuss its pathogenesis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00294266
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  • 14
    Electronic Resource
    Electronic Resource
    Immunogold labelling of paired helical filaments and amyloid fibrils by specific monoclonal and polyclonal antibodies (1995)
    Springer
    Acta neuropathologica 90 (1995), S. 441-447 
    Details
    ISSN: 1432-0533
    Keywords: Alzheimer's disease ; Neurofibrillary tangles ; Amyloid ; Ultrastructure ; Immunohistochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Senile plaque and paired helical filament (PHF) formation are characteristic of Alzheimer's disease, but the mechanisms leading to these lesions still remain unclear. To understand them better, we have performed different immunolabellings of amyloid protein and PHF. We describe a very specific immunodetection of PHF with AD2, a monoclonal antibody directed against a hyperphosphorylated epitope of PHF-tau, and use double immunolabelling to show that PHF and plaque amyloid are discretely labbeled by different antibodies. We also discuss different mechanisms of PHF maturation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00294803
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  • 15
    Electronic Resource
    Electronic Resource
    Subcortical microtubule network separates the periplasm from the endoplasm and is responsible for maintaining the position of accessory nuclei in hymenopteran oocytes (1995)
    Springer
    Development genes and evolution 205 (1995), S. 54-61 
    Details
    ISSN: 1432-041X
    Keywords: Oogenesis ; Cytoskeleton ; Accessory nuclei ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Oocytes of hymenopterans are equipped with peculiar organelles termed accessory nuclei. These organelles originate from the germinal vesicle (oocyte nucleus) and gather preferentially at the anterior pole. To gain insight into the mechanism of uneven (asymmetrical) distribution of accessory nuclei, the organization of the microtubule cytoskeleton in the oocytes of two hymenopterans Chrysis ignita and Cosmoconus meridionator has been studied. It is shown that during late previtellogenesis two networks of microtubules are present along the contact zone between the oocyte and enveloping follicular epithelium. The external one is associated with belt desmosomes connecting neighbouring follicular cells. The internal network is composed of randomly orientated microtubules and separates transparent, organelle-free periplasm from the endoplasm. All cellular organelles and the germinal vesicle are localized in the endoplasm. Accessory nuclei are accumulated in the anterior endoplasm; they always lie in direct contact with the subcortical network. Treatment with colchicine results in the disappearance of the periplasm as well as in the redistribution of cellular organelles including accessory nuclei. Presented findings suggest that subcortical microtubules play an important role in the positioning of accessory nuclei throughout the ooplasm.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00188843
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  • 16
    Electronic Resource
    Electronic Resource
    Die hämatopoietische Stammzelle des Menschen Funktion und Morphologie* (1995)
    Springer
    Der Pathologe 16 (1995), S. 1-10 
    Details
    ISSN: 1432-1963
    Keywords: Schlüsselwörter Hämatopoietische Stammzellen ; CD 34+-Progenitorzellen ; Morphologie ; Ultrastruktur ; Antigenität ; Funktion ; Key words Haematopoietic stem cells ; CD 34+ progenitor cells ; Morphology ; Ultrastructure ; Antigen expression ; Function
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Summary Pluripotential haematopoietic stem cells and their progeny, the so-called committed precursor cells, i. e., progenitor cells which are already lineage-restricted, may be identified by the membrane-bound expression of CD 34. In accordance with this peculiar property it became possible to enrich and characterize primitive precursor cells by using different methods of cell separation techniques, which involved fluorescence staining or ferro-magnetic particles bound to CD 34 antibodies. Recently conducted studies demonstrate that CD 34-positive (CD 34+) stem cells of the peripheral blood represent a relatively uniform cell population with almost round nuclei, a finely dispersed chromatin pattern and a small portion of weakly basophilic cytoplasm. From the cytological viewpoint they resemble so-called large stimulated lymphocytes (virocytes). Ultrastructural studies are compatible with a paucity of organelles and a lymphoid character of these progenitors. In comparison, the stem cell population, derived from the bone marrow consists of more heterogeneous elements. These are generally larger and reveal an admixture of fairly immature as well as more differentiated cells, sharing bean-shaped or indented nuclei with prominent nucleoli and a more extended cytoplasm. CD 34+ progenitors from the peripheral blood and those from the bone marrow display a co-expression of CD 43 (MT1) and CD 45 (LCA). Furthermore, different subpopulations exhibit – dependent on their origin (blood/bone marrow) and to a various extent – lineage-restricted markers like CD 33, CD 38, CD 61, CD 20, CD 11a/c, glycophorin C und CD 15 (LeuM 1). The recently developed immuno- and ferromagnetic enrichment methods for CD 34+ progenitor cells are considered innovative tools for modern oncology. These techniques play an important role in the treatment of haematological malignancies and advanced tumours in the context of autologous and, although so far rarely applied, heterologous stem cell transplantation procedures.
    Notes: Zusammenfassung Hämatopoietische Stammzellen, d. h. Progenitorzellen, die bereits in Richtung einer bestimmten Zellreihe festgelegt sind, lassen sich immunzytochemisch durch Nachweis der membranständigen Expression von CD 34 darstellen. Aufgrund dieser Eigenschaft ist es möglich geworden, Vorläuferzellen durch unterschiedliche Zellseparationsverfahren anzureichern und genauer zu charakterisieren. Neuere Untersuchungen zeigen, daß CD 34-positive (CD 34+-) Stammzellen des Blutes einer relativ uniformen Zellpopulation angehören. Zytologisch deuten sie in Routinefärbungen Aspekte sog. lymphoider Reizformen bzw. Virozyten an. Ultrastrukturelle Untersuchungen bestätigen den relativ organellenarmen Charakter der Progenitorzellen. Vergleichsweise stellt sich die entsprechende Zellpopulation aus dem Knochenmark als wesentlich heterogeneres Zellgemisch dar. Sowohl die CD 34+-Stammzellen des Blutes wie des Knochenmarks weisen eine Expression von CD 43 (MT1) und CD 45 (LCA) auf. Weiterhin zeigen Subpopulationen in Abhängigkeit von ihrem Vorkommen (Peripherie/Knochenmark) und in unterschiedlicher Ausprägung linienspezifische Marker. Die kürzlich entwickelten, v. a. immunomagnetischen Anreicherungsverfahren für CD 34+-Stammzellen stellen bedeutende Perspektiven für die moderne Onkologie dar. Sie sind insbesondere für die Therapie hämatologischer Neoplasien und fortgeschrittener maligner Tumoren im Rahmen von Stammzelltransplantationen, von größter klinischer Bedeutung.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002920050070
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  • 17
    Electronic Resource
    Electronic Resource
    Sex segregation ratio and gender expression in the genus Actinidia (1995)
    Springer
    Sexual plant reproduction 8 (1995), S. 129-132 
    Details
    ISSN: 1432-2145
    Keywords: Sex control ; Disomic segregation ; Dioecy Kiwifruit ; Genetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The sex segregation ratio was checked in bi-parental families of Actinidia deliciosa (2n=6x=174) obtained by crossing four females (A12, Mo3, Br4, Hw1) with two males (T2, M1) and one fruiting male (M3h, subandroecious) according to a factorial mating design. The M3h fruiting male was also selfed. The sex ratio was checked in maternal families of A. kolomikta (2n=2x) and A. chinensis (2n=2x) as well as in A. deliciosa. Seedlings of both diploid species took 3–4 years to progress beyond juvenility, whereas a noticeable number of seedlings from biparental crosses of A. deliciosa involving A12 and Hw1 as seed parents were still non-flowering after seven growing seasons. Open-pollinated families of both diploid and hexaploid species as well as most families from biparental crosses showed a sex segregation ratio approaching 1∶1. Subandroecious lines with different degrees of ovary and pistil development appeared in proportions of 0–4.2%, depending on the cross, but only 6 of the 2567 male vines checked were capable of setting fruit. No case of self-fertility or apomixis was detected among 1866 bagged female vines. Selfed M3h progenies gave only female and male phenotypes in a ratio of 1 female to 3 males. No off-type vines were found among these progenies. The same disomic sex segregation ratio seems to be operating at different ploidy levels in the genus Actinidia. Since selfed fruiting males produced both female and male individuals, the male sex appears to be the heterogametic one. Such evidence indicates that a monofactorial system based on one or more linked genes or on an X/Y chromosome set must be controlling sex expression. How a monofactorial sex-determining mechanism could operate in polyploids to give a 1∶1 female: male ratio is discussed. Minor modifying gene(s) seem to be responsible for the feminization of males, and their expression appears enhanced by environmental conditions. Masculinizing gene(s) seem to be lacking in female genotypes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00242255
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  • 18
    Electronic Resource
    Electronic Resource
    Ultrastructural characterization of apospory in Panicum maximum (1995)
    Springer
    Sexual plant reproduction 8 (1995), S. 197-204 
    Details
    ISSN: 1432-2145
    Keywords: Apomixis ; Apospory ; Aposporous initial ; Aposporous embryo sac ; Ultrastructure ; Panicum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The nucellar ultrastructure of apomictic Panicum maximum was analyzed during the meiocytic stage and during aposporous embryo sac formation. At pachytene the megameiocyte shows a random cell organelle distribution and sometimes only an incomplete micropylar callose wall. The chalazal nucellar cells are meristematic until the tetrad stage. They can turn into initial cells of aposporous embryo sacs. The aposporous initials can be recognized by their increased cell size, large nucleus, and the presence of many vesicles. The cell wall is thin with few plasmodesmata. If only a sexual embryo sac is formed, the nucellar cells retain their meristematic character. The aposporous initial cell is somewhat comparable to a vacuolated functional megaspore. It shows large vacuoles around the central nucleus and is surrounded by a thick cell wall without plasmodesmata. In the mature aposporous embryo sac the structure of the cells of the egg apparatus is similar to each other. In the chalazal part of the egg apparatus the cell walls are thin and do not hamper the transfer of sperm cells. Structural and functional aspects of nucellar cell differentiation and aposporous and sexual embryo sac development are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00228937
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  • 19
    Electronic Resource
    Electronic Resource
    Opioid operant self-administration, analgesia, stimulation and respiratory depression inμ-deficient mice (1995)
    Springer
    Psychopharmacology 117 (1995), S. 23-31 
    Details
    ISSN: 1432-2072
    Keywords: Opioid ; Genetics ; Self-administration ; CXBK/ByJ ; Reinforcement
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract It is commonly thought thatμ-receptors play an important role in the reinforcing effects of opioids. In the present study, inbred strains widely divergent in CNS opiate receptor densities were used to investigate the influence of genetic variation in receptor concentration on opioid-reinforced behavior. In particular, the CXBK/ByJ mice were used as an investigative tool because of their significantly lower number of CNSμ opioid receptors. The behavioral pharmacology of opioids in theμ-deficient CXBK/ByJ mice was compared to other commonly used inbred mouse strains, C57BL/6J and BALB/cJ, and the opiate receptor rich CXBH/ByJ mice. Operant opioid reinforced behavior, opioid-induced locomotor stimulation, analgesia and respiratory depression were investigated in all four inbred strains. To assess the acquisition and maintenance of opioid reinforced behavior, oral self-administration of the potent benzimidazole opioid, etonitazene, was determined using an operant fixed-ratio schedule of reinforcement (FR 8). Acquisition of etonitazene-reinforced behavior was established in all four strains including theμ-deficient CXBK/ByJ mice. However, there were significant genetic differences in the amount of drug intake during the maintenance of opioid-reinforced behavior and extinction behavior following vehicle substitution. For example, drug intake was significantly greater in the BK versus BH mice during the maintenance phase and an extinction burst was seen in the BH but not the BK mice following vehicle substitution. Thus,μ-receptor density may not account for individual variability in the acquisition of opioid-reinforced behavior under these conditions. Sensitivity to etonitazene-induced respiratory depression, stimulation of locomotor activity and analgesia were unrelated to drug intake during self-administration sessions across these four inbred strains. These data indicate that inherited differences in CNSμ-opiate receptor concentrations do not affect acquisition of etonitazene-reinforced behavior.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02245094
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  • 20
    Electronic Resource
    Electronic Resource
    Chromosomal mapping of loci influencing sensitivity to cocaine-induced seizures in BXD recombinant inbred strains of mice (1995)
    Springer
    Psychopharmacology 117 (1995), S. 62-66 
    Details
    ISSN: 1432-2072
    Keywords: Cocaine ; Quantitative trait loci ; Seizure ; Recombinant inbred strains ; Genetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Among inbred mice, genetic factors mediate differences in sensitivity to the convulsant properties of cocaine; however, the gene(s) underlying cocaine's effects have not been identified. To help elucidate the gene(s) responsible for cocaine seizure susceptibility, we used recombinant inbred-quantitative trait loci (RI-QTL) analyses to identify chromosomal loci associated with cocaine-induced seizures. RI-QTL analyses seek to identify associations between a quantitative measure of a particular phenotype and one or more previously mapped marker genes across a panel of RI strains. This report describes an RI-QTL analysis of cocaine seizure susceptibility among 26 BXD RI strains. These strains showed a skewed, bimodal range of seizure susceptibility which could be the result of one or more modifying genes acting in concert with a major gene to influence cocaine sensitivity. Correlating the percent seizures displayed by each strain following 60 mg/kg cocaine with chromosomal marker data for these strains revealed a number of significant correlations clustered in two regions on chromosomes 12 and 6. This is the first identification of putative chromosomal loci associated with a cocaine-related phenotype and should facilitate identification of the gene(s) underlying cocaine toxicity and other cocaine-related phenotypes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02245099
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  • 21
    Electronic Resource
    Electronic Resource
    Genetic counselling on brittle grounds: recurring osteogenesis imperfecta due to parental mosaicism for a dominant mutation (1995)
    Springer
    European journal of pediatrics 154 (1995), S. 123-129 
    Details
    ISSN: 1432-1076
    Keywords: Key words Osteogenesis imperfecta ; Collagen I ; Mosaicism ; Genetics ; Recurrence risk
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Osteogenesis imperfecta (OI), a dominantly inherited connective tissue disorder, is usually caused by defects in collagen I. There is growing evidence for parental mosaicism that results in affected children born to unaffected parents. This situation poses a difficult task for the geneticist because a mosaic parent may appear clinically healthy while carrying the mutation in a fraction of her or his gonadal cells. To illustrate this problem, we report a Swiss couple whose first child was affected with severe OI. The unexpected recurrence of the disorder in the second child raised the suspicion of a recessive trait or, rather, of parental mosaicism. We identified the responsible collagen mutation in the COL1A2 gene (Gly688Ser in the α2(I)-chain) in both children and demonstrated the father to be a somatic mosaic for this mutation and to have subtle clinical signs such as soft skin and short stature that may be a result of his mosaic state.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004310050261
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  • 22
    Electronic Resource
    Electronic Resource
    Floating-Harbor syndrome: description of a further patient, review of the literature, and suggestion of autosomal dominant inheritance (1995)
    Springer
    European journal of pediatrics 154 (1995), S. 658-661 
    Details
    ISSN: 1432-1076
    Keywords: Floating-Harbor syndrome ; Growth retardation ; Dysmorphology ; Genetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Abstract The Floating-Harbor syndrome is a growth retardation syndrome with delayed bone age, speech development, and typical facial features. The face is triangular with deep-set eyes, long eyelashes, bulbous nose, wide columella, short philtrum, and thin lips. We present an additional patient and review 16 cases from the literature. The possible phenotype in the patient's mother suggests a dominant mode of inheritance for the syndrome. Conclusion The Floating Harbor syndrome is a growth deficiency syndrome characterized by proportionate short stature, characteristic face and delayed speech development. Inheritance is possibly autosomal dominant.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02079072
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  • 23
    Electronic Resource
    Electronic Resource
    Fetal brain disruption sequence in sisters (1995)
    Springer
    European journal of pediatrics 154 (1995), S. 654-657 
    Details
    ISSN: 1432-1076
    Keywords: Fetal development ; Brain diseases ; Genetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract We report two female siblings with the fetal brain disruption sequence. Extensive investigation of both children failed to define a definitive aetiology but clinical and laboratory findings are consistent with a hitherto unknown storage disease. We postulate that the accumulation of a neurotoxic metabolite may be responsible for the disease phenotype observed. This is the first report of recurrence of the fetal brain disruption sequence and supports the existence of a genetic form of this condition. Previous reports have emphasized possible environmental aetiologies. Infants with fetal brain disruption sequence should be investigated exhaustively and, in the absence of definitive evidence of an environmental cause, the possibility of a genetic aetiology should be considered. In some families the recurrence risk may be as high as one in four.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02079071
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  • 24
    Electronic Resource
    Electronic Resource
    Fetal brain disruption sequence in sisters (1995)
    Springer
    European journal of pediatrics 154 (1995), S. 654-657 
    Details
    ISSN: 1432-1076
    Keywords: Key words Fetal development ; Brain diseases ; Genetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract We report two female siblings with the fetal brain disruption sequence. Extensive investigation of both children failed to define a definitive aetiology but clinical and laboratory findings are consistent with a hitherto unknown storage disease. We postulate that the accumulation of a neurotoxic metabolite may be responsible for the disease phenotype observed. This is the first report of recurrence of the fetal brain disruption sequence and supports the existence of a genetic form of this condition. Previous reports have emphasized possible environmental aetiologies. Infants with fetal brain disruption sequence should be investigated exhaustively and, in the absence of definitive evidence of an environmental cause, the possibility of a genetic aetiology should be considered. In some families the recurrence risk may be as high as one in four.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004310050366
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  • 25
    Electronic Resource
    Electronic Resource
    Floating-Harbor syndrome: description of a further patient, review of the literature, and suggestion of autosomal dominant inheritance (1995)
    Springer
    European journal of pediatrics 154 (1995), S. 658-661 
    Details
    ISSN: 1432-1076
    Keywords: Key words Floating-Harbor ; syndrome ; Growth retardation ; Dysmorphology ; Genetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The Floating-Harbor syndrome is a growth retardation syndrome with delayed bone age, speech development, and typical facial features. The face is triangular with deep-set eyes, long eyelashes, bulbous nose, wide columella, short philtrum, and thin lips. We present an additional patient and review 16 cases from the literature. The possible phenotype in the patient's mother suggests a dominant mode of inheritance for the syndrome. Conclusion The Floating Harbor syndrome is a growth deficiency syndrome characterized by proportionate short stature, characteristic face and delayed speech development. Inheritance is possibly autosomal dominant.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004310050367
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  • 26
    Electronic Resource
    Electronic Resource
    A genetic study of idiopathic focal dystonias (1995)
    Springer
    Journal of neurology 242 (1995), S. 508-511 
    Details
    ISSN: 1432-1459
    Keywords: Dystonia ; Torticollis ; Blepharospasm ; Genetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The inheritance of focal dystonias was investigated in 43 families containing 43 index cases with torticollis (n = 21), blepharospasm (n = 18) and writer's cramp (n = 4). They generated a potential population of 235 first-degree relatives, and 168 out of 179 living first-degree relatives were examined. Ten relatives with dystonia were identified in ten families. Another two parents from two of the same group of ten families were affected according to the family history. The majority of the secondary cases (six patients, five siblings, and one child) were not aware of any dystonia. The tendency for affected relatives to have the same type of dystonia as index patients was observed only for torticollis. Overall, 23% of index patients had relatives with dystonia. Segregation analysis suggested the presence of an autosomal dominant gene or genes with reduced penetrante underlying focal dystonia.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00867421
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  • 27
    Electronic Resource
    Electronic Resource
    Genetische Faktoren bei der Entstehung und Progression maligner Melanome (1995)
    Springer
    Der Hautarzt 46 (1995), S. 394-399 
    Details
    ISSN: 1432-1173
    Keywords: Schlüsselwörter Malignes Melanom ; Genetische Instabilität ; Genetik ; Syndrom der dysplastischen Nävi ; Xeroderma pigmentosum ; Key words Malignant melanoma ; Genetic instability ; Genetics ; Dysplastic nevus syndrome ; Xeroderma pigmentosum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Summary Exposure of the skin to ultraviolet irradiation is an important risk factor for the development of malignant melanoma, with UVA possibly playing an important role. Hereditary factors are also relevant. In the dysplastic nevus syndrome a genetic instability has been shown by different methods. In xeroderma pigmentosum the DNA repair defect is thought to be responsible for the high incidence of malignant melanoma. Frequent and non-random changes in certain chromosomes have been demonstrated in melanoma cells. These might contain sequences that control melanoma growth or melanoma suppressor genes. Especially the short arm of chromosome 9 is thought to contain one of these genes. This hypothesis is supported by a genetic linkage analysis in melanoma families and the demonstration of a germ line deletion of the locus 9p21 in a patient with eight primary melanomas. Changes in known tumor suppressor genes and oncogenes have also been reported in melanoma, but no consistent sequence of genetic events is known.
    Notes: Zusammenfassung Die Exposition der Haut mit ultravioletten Strahlen ist ein wichtiger Risikofaktor für die Entwicklung eines malignen Melanoms. Möglicherweise spielt hierbei UVA-A eine besondere Rolle. Daneben sind hereditäre Faktoren von Bedeutung. Während beim Syndrom der dysplastischen Nävi eine genetische Instabilität mit verschiedenen Methoden nachgewiesen wurde, wird bei Xeroderma pigmentosum der DNA-Reparaturdefekt für die hohe Melanominzidenz verantwortlich gemacht. In Melanomzellen sind überzufällig häufig karyotypische Veränderungen in bestimmten Chromosomen gefunden worden. Diese enthalten möglicherweise Melanomwachstumsregulierende Sequenzen oder Melanom-Suppressorgene. Insbesondere der kurze Arm des Chromosoms 9 steht in Verdacht, eines dieser Gene zu enthalten. Diese Hypothese wird auch unterstützt durch eine genetische Kopplungsanalyse an Melanomfamilien und dem Nachweis einer Keimbahndeletion des Lokus 9p21 bei einer Patientin mit 8 primären Melanomen. Veränderungen an bereits bekannten Tumorsuppressorgenen oder Onkogenen sind ebenfalls in Melanomen beschrieben worden, ohne daß jedoch eine konsistente Reihenfolge von genetischen Ereignissen bekannt wäre.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s001050050272
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  • 28
    Electronic Resource
    Electronic Resource
    Myotonic dystrophy in a large Sicilian kinship: a case report (1995)
    Springer
    Child's nervous system 11 (1995), S. 453-455 
    Details
    ISSN: 1433-0350
    Keywords: Myotonic ; Dystrophy ; Muscle disease ; Genetics ; Case report
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract A large Sicilian kinship in which myotonic dystrophy (DM) affected spanning four generations is presented. The pedigree clearly illustrates the phenomenon of anticipation, and illustrates that this phenomenon is more marked when transmission occurs through an affected female rather than an affected male. The pedigree is interpreted in light of recent genetic advances in DM. Neurosurgeons and neurologists should consider a diagnosis of DM when asked to evaluate a floppy infant with enlarged lateral ventricles, and should be aware of special features regarding its inheritance pattern.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00334964
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  • 29
    Electronic Resource
    Electronic Resource
    Aluminium causes nutrient imbalance and structural changes in the needles of Scots pine without inducing clear root injuries (1995)
    Springer
    Trees 9 (1995), S. 134-142 
    Details
    ISSN: 1432-2285
    Keywords: Pinus sylvestris L. ; Aluminium ; Nutrients ; Mycorrhiza ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The effects of aluminium chloride (AICI3) treatments (50 and 150 mg/l) on 3-year-old Scots pine (Pinus sylvestris L.) seedlings were studied in a sand culture during 2 growing periods in an open field experiment. Even by the end of the first growing period, a decline was observed in the concentrations of Ca, Mg and P within the needles, and of Ca and Mg in the roots. After the second growing period, increased N and K concentrations were observed in the needles of Al-treated seedlings. Both the needles and roots of Al-treated seedlings showed, after the second growing period, a decline in growth and increased concentrations of AI as the amount of AICI3 in the nutrient solution increased. Al-induced changes in needle structure were found to be symptomatic of a nutrient imbalance, particularly of Mg and P. Al-stress did not result in any observable changes in root anatomy or in the number of mycorrhizas. Scots pine proved to be rather resistant to Al-stress, indicating that direct Al-injuries are not likely in the field, though Al-stress may be a contributing factor in the formation of nutrient imbalances.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02418202
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  • 30
    Electronic Resource
    Electronic Resource
    Observations of chemical processing in the circumstellar environment (1995)
    Springer
    Astrophysics and space science 224 (1995), S. 81-84 
    Details
    ISSN: 1572-946X
    Keywords: Chemistry ; Depletions ; Shocks ; IRAS 05338-0624 ; NGC 1333 IRAS 4
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract High resolution interferometer and single-dish observations of young, deeply embedded stellar systems reveal a complex chemistry in the circumstellar environments of low to intermediate mass stars. Depletions of gas-phase molecules, grain mantle evaporation, and shock interactions actively drive chemical processes in different regions around young stars. We present results for two systems, IRAS 05338-0624 and NGC 1333 IRAS 4, to illustrate the behavior found and to examine the physical processes at work.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00667826
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  • 31
    Electronic Resource
    Electronic Resource
    Characterization of Japanese families with early-onset type 2 (non-insulin dependent) diabetes mellitus and screening for mutations in the glucokinase and mitochondrial tRNALeu(UUR) genes (1995)
    Springer
    Acta diabetologica 32 (1995), S. 17-22 
    Details
    ISSN: 1432-5233
    Keywords: Maturity-onset diabetes of the young (MODY) ; Genetics ; Diabetes mellitus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Genetic linkage studies of families with earlyonset type 2 diabetes have facilitated the identification of diabetes-susceptibility genes. In order to assess the feasibility of using linkage approaches to identify genes responsible for the development of type 2 diabetes in Japanese subjects, we examined our clinical records for multigenerational families suitable for genetic studies. We identified 16 families in which at least one subject was diagnosed with type 2 diabetes before 25 years of age. Seven of these families had a pattern of inheritance consistent with a diagnosis of maturity-onset diabetes of the young (MODY) and nine families showed a complex pattern of inheritance of type 2 diabetes with transmission of diabetes-susceptibility genes from both parents. The glucokinase and mitochondrial tRNALeu(UUR) genes were screened for mutations in at least one affected subject from each family in order to assess the contribution of mutations in these genes to the development of the diabetes. No mutations were found, which suggests that the diabetes in these families resulted from mutations in other genes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00581039
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  • 32
    Electronic Resource
    Electronic Resource
    Mitochondrial abnormalities of muscle tissue in mice with juvenile visceral steatosis associated with systemic carnitine deficiency (1995)
    Springer
    Virchows Archiv 426 (1995), S. 271-279 
    Details
    ISSN: 1432-2307
    Keywords: JVS mouse ; Systemic carnitine deficiency ; Mitochondrial abnormality ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract A mouse with juvenile visceral steatosis (the JVS mouse) has been recognized as a novel animal model for systemic carnitine deficiency. We examined cardiac, skeletal and smooth muscle cells in JVS and control mice by light and electron microscopy. Cardiac and skeletal muscle cells of these mice at 4 weeks of age exhibited a ragged-red appearance after trichrome staining. Electron microscopy, demonstrated increased numbers of mitochondria and lipid droplets in the cells. Compression or distortion of the myofibril bundles, primarily due to the increased number of mitochondria, suggests the possible existence of a functional disturbance of the cardiac and skeletal muscle. In the urinary bladder, only one or two large lipid droplets and slightly increased number of mitochondria were recognized in the perinuclear region of the smooth muscle cells. At 8 weeks of age, the mouse enzyme histochemistry specific for mitochondria, such as cytochrome c oxidase and succinic dehydrogenase, and oil red O staining, confirmed further increases in the number of mitochondria and lipid droplets in the heart. However, the accumulation of these organelles in the skeletal and smooth muscle cells was no greater than that noted in JVS mice at 4 weeks of age. In the cardiac muscle cells, autolysosomes or autophagic vacuoles containing electron-dense membranous, lamellar or whorled structures closely associated with mitochondria and pseudoinclusion bodies in the nucleus were recognized, and bundles of myofibrils were buried under numerous mitochondria, suggesting the existence of disturbed contractile function in the heart of JVS mice. These results indicate that this murine strain associated with systemic carnitine deficiency exhibits a generalized mitochondrial abnormality in the muscle system especially in the heart.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00191365
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  • 33
    Electronic Resource
    Electronic Resource
    Ultrastructural changes in the lung in Niemann-Pick type C mouse (1995)
    Springer
    Virchows Archiv 427 (1995), S. 77-83 
    Details
    ISSN: 1432-2307
    Keywords: Niemann-Pick disease ; Mouse ; Lung ; Electron microscope ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The biochemical and morphological aspects of BALB/c mice with many features of the Niemann-Pick disease type C in man (NP-C mouse) have been studied extensively. However, the pulmonary pathology has not been studied extensively and we describe here some unique ultrastructural features of the lung in the NP-C mouse. Ultrastructurally, macrophages in younger mice contained osmiophilic dense granules and annulolamellar structures, but larger multilamellar concentric structures increased in the macrophages of older mice. In contrast, endothelial cells and type I pneumocytes showed membrane-bound bodies with dense granules and vesicular or vesiculogranular structures as well as amorphous materials. Type II pneumocytes were unremarkable throughout. Our study suggests that endothelial cells and type I pneumocytes are the major site of metabolic derangement resulting in pronounced morphological changes with granular and round membranous structures in the lungs of NP-C mouse. Alveolar macrophages with multilamellar concentric structures may be a result of disturbed disposal of surfactant material from type II pneumocytes rather than that from storage material of type I pneumocyte.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00203741
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  • 34
    Electronic Resource
    Electronic Resource
    Domestication via hybridization of the wild tetraploid oats Avena magna and A. murphyi (1995)
    Springer
    Theoretical and applied genetics 91 (1995), S. 639-646 
    Details
    ISSN: 1432-2242
    Keywords: Gene introgression ; Genetics ; Linkage ; Taxonomy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The wild tetraploid (2n=28) oat species Avena magna and A. murphyi have been domesticated by having been transferred from the common oat, A sativa (2n=42), the characteristics of non-shedding spikelets glabrous and yellow lemma, and reduced awn formation. Domestication has been achieved by crossing the common oat with either of the tetraploid species and then backcrossing the pentaploid hybrids with pollen of the tetraploid wild parent. Among the BC plants obtained only a few produced some seeds. Fertile tetraploids exhibiting the domesticated syndrome have been selected for in the F2 generation. Although morphologically they were almost indistinguishable from the common oat, they were tetraploids. Wild x domesticated A. magna hybrids were vigorous and fertile. They retained their spikelets at maturity, lemma color and pubescence were intermediate between the parental lines, and awns were formed only on the lower floret of the spikelet. Each of these characteristics segregated in a 3∶1 fashion, indicating single gene control, as in the common oat. These four characteristics formed a linkage group in one F2 family and two linkage groups in the other two families. The usefulness of the domesticated tetraploids for oat research and production has been discussed. Taxonomically, the domesticated tetraploids were ranked as subspecies: A. magna ssp. domestica, and A. murphyi ssp. rigida.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00223291
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  • 35
    Electronic Resource
    Electronic Resource
    Diallel analysis for mineral element absorption in tropical adapted soybeans [Glycine max (L.) Merrill] (1995)
    Springer
    Theoretical and applied genetics 90 (1995), S. 707-713 
    Details
    ISSN: 1432-2242
    Keywords: Mineral stress ; Nutrient efficiency ; Aluminium tolerance ; Inheritance ; Genetics ; Breeding
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The Brazilian tropical adapted soybeans contains, in addition to superior morphological characters, genetic factors for tolerance to cultivation in acidic, mineral-stressed soils. However, the selection process for these hindrances has been empirical, and information on the genetics of mineral element uptake by the plant is necessary. The objective of this investigation was to identify the mode of inheritance for the absorption of phosphorus, potassium, calcium, magnesium, iron, aluminium, manganese, zinc and copper in a 9 × 9 diallel cross. General combining ability (GCA) was higher than specific combining ability (SCA), with the exception of copper, manganese and zinc, indicating predominantly additive effects. The ratios of GCA/SCA varied between 3.4 (calcium) and 8.5 (magnesium). The regression of covariance (Wr) on variance (Vr) showed that the additive-dominance model explained the genetic differences in this germ plasm. However, the detection of overdominance could be related to possible heterozygosity in the parental varieties for mineral absorption. Broad-sense heritability values were higher than narrow sense heritability values for aluminium, iron, potassium, calcium and magnesium, being in the range of 67.9–86.9% and 42.0–56.6%, respectively. This is an indication that soybeans can be further improved to efficient utilisation of nutrients and to tolerate toxic factors in the soil.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00222137
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  • 36
    Electronic Resource
    Electronic Resource
    Allelic relationships between genes for resistance to tomato spotted wilt tospovirus in Capsicum chinense (1995)
    Springer
    Theoretical and applied genetics 90 (1995), S. 146-149 
    Details
    ISSN: 1432-2242
    Keywords: Capsicum chinense ; Resistance gene ; Genetics ; Pepper ; Tomato spotted wilt virus ; Tospoviruses
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Pepper (Capsicum chinense Jacq.) has been reported to be an important reservoir of resistance genes to tomato spotted wilt virus (TSWV). The genes for TSWV resistance present in three C. chinense lines (‘PI 152225’, ‘PI 159236’ and ‘Panca’) were investigated for allelism. All resistant lines were crossed with each other. Parents, F1, backcrosses and F2 populations (including reciprocals) developed from those crosses were mechanically inoculated with a highly virulent TSWV isolate. Susceptible C. annuum cv ‘Magda’ was used to check inoculum virulence. Fifty plants of the F1 hybrids; ‘Magda’ x ‘PI 152225’, ‘Magda’ x ‘PI 159236’, and ‘Magda’ x 'Panca, were also inoculated with the TSWV isolate. The resistance response in all C. chinense sources was associated with a localized, hypersensitive-like reaction that was phenotypically expressed as a prompt formation of large local lesions accompanied by premature leaf abscission. All F1 generations presented a final score of resistant; indicating that the expression of resistance to TSWV is conditioned by a dominant gene regardless of the source. The absence of segregation for resistance to TSWV that was observed in all generations of the crosses between C. chinense lines indicated that either a tightly linked group of genes exists or that the resistance is governed by the same single major gene (probably the already described Tsw gene). Previous reports have indicated that the Tsw gene is not effective against tospovirus members of serogroup II, i.e. tomato chlorotic spot virus (TCSV) and groundnut ring spot virus (GRSV). In the assay described here, all of the C. chinense lines showed, after mechanical inoculation, an identical susceptibility response to the TCSV and GRSV isolates.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00221009
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  • 37
    Electronic Resource
    Electronic Resource
    Identification of genomic regions affecting plant height in sorghum and maize (1995)
    Springer
    Theoretical and applied genetics 90 (1995), S. 380-388 
    Details
    ISSN: 1432-2242
    Keywords: Genetics ; Breeding ; Sorghum bicolor Zea mays
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The objective of this study was to use restriction fragment length polymorphisms (RFLPs) to determine the genetic location and effects of genomic regions controlling plant height in sorghum. F2 plants (152) from the cross CK60 x PI229828 were used. Genomic and cDNA clones (106) identified 111 loci distributed among ten linkage groups covering 1299 cM. Interval mapping identified four regions, each in a separate linkage group. These regions may correspond to loci (dw) previously identified by alleles with qualitative effects. Also, these regions identified in sorghum may be orthologous to those previously reported for plant height in maize. Gene effects and gene action varied among genomic regions. In each region, PI229828 alleles resulted in increased plant height. Each region accounted for 9.2–28.7% of the phenotypic variation. Positive, additive effects ranged from 15 to 32cm. Tallness was dominant or overdominant and conferred by alleles from PI229828 for three quantitative trait loci (QTL). At the fourth QTL, PI229828 contributed to increased plant height, but short stature was partially dominant. One digenic interaction was significant. The presence of a PI229828 allele at one region diminished the effects of the other region. A multiple model indicated that these four regions collectively accounted for 63.4% of the total phenotypic variation. The utility of this information for germplasm conversion through backcross breeding is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00221980
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  • 38
    Electronic Resource
    Electronic Resource
    Differences in synaptic output between excitatory and inhibitory motoneurons in a crayfish muscle (1995)
    Springer
    Cell & tissue research 280 (1995), S. 513-518 
    Details
    ISSN: 1432-0878
    Keywords: Key words: Axo-axonal synapse ; Neuromuscular synapse ; Motoneuron ; Ultrastructure ; Procambarus clarkii (Crustacea)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. A pair of antagonistic motoneurons, one excitatory and one inhibitory, innervates the distal accessory flexor muscle in the walking limb of the crayfish Pro- cambarus clarkii. The number and size of synapses formed by these two axons on the muscle fibers (neuromuscular synapses) and on each other (axo-axonal synapses) were estimated using thin-section electron microscopy. Although profiles of nerve terminals of the two axons occur in roughly equal proportions, the frequency of occurrence of neuromuscular synapses differed markedly: 73% were excitatory and 27% were inhibitory. However, inhibitory synapses were 4–5 times larger than excitatory ones, and consequently, the total contact areas devoted to neuromuscular synapses were similar for both axons. Axo-axonal synapses were predominantly from the inhibitory axon to the excitatory axon (86%), and a few were from the excitatory axon to the inhibitory axon (14%). The role of the inhibitory axo-axonal synapse is presynaptic inhibition, but that of the excitatory axo-axonal synapse is not known. The differences in size of neuromuscular synapses between the two axons may reflect intrinsic determinants of the neuron, while the similarity in total synaptic area may reflect retrograde influences from the muscle for regulating synapse number.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00318355
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  • 39
    Electronic Resource
    Electronic Resource
    Evolution and ultrastructure of the bovine spermatogonia precursor cell line (1995)
    Springer
    Cell & tissue research 281 (1995), S. 249-259 
    Details
    ISSN: 1432-0878
    Keywords: Key words: Stem cells ; Testis ; PGP 9.5 ; Ultrastructure ; Tubular whole-mounts ; Bovine
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. The spermatogonial stem cell line in prepubertal and adult bovine testis was studied by electron microscopy and protein gene product 9.5 immunohistochemistry. Three successive spermatogonia precursor cell configurations were observed. Small basal stem cells were found to possess a spherical shape and nuclei with two to three nucleoli. They were observed in prepubertal testes (25 and 30 weeks) and in low numbers during all the stages of the seminiferous epithelial cycle in the adult. Aggregated spermatogonia precursor cells are the dominating germ cell type in the 25-week-old and 30-week-old calf. In the adult seminiferous epithelium, they cause expansion of the basal tubular compartment as they form dense groups containing up to 15 cells. These groups are observed concomitantly with cycling A-spermatogonia and preleptotenes at the beginning of spermatocytogenesis. At the end of A-spermatogonia propagation, the aggregated spermatogonia precursor cells separate and intermingle with cycling A-spermatogonia. The spermatogonia precursor cells can later be found together with I-spermatogonia as members of an interconnected cellular network of medium-sized cells. When the I-spermatogonia divide to form the smaller B-spermatogonia, the precursor cells, which stay connected with the cycling spermatogonial population, pass through a growth phase. They can now be considered as committed spermatogonia precursor cells and are continuously being transformed into A1-spermatogonia to start a new round of spermatocytogenesis. Ultrastructurally, all members of the precursor cell line are similar. However, a number of features have been found to show a quantitative increase (endoplasmic reticulum, mitochondria) or to exhibit a rising degree of complexity (nucleolus) during the progression from basal stem cells to committed spermatogonia precursor cells.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00583394
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  • 40
    Electronic Resource
    Electronic Resource
    Evolution and ultrastructure of the bovine spermatogonia precursor cell line (1995)
    Springer
    Cell & tissue research 281 (1995), S. 249-259 
    Details
    ISSN: 1432-0878
    Keywords: Stem cells ; Testis ; PGP 9.5 ; Ultrastructure ; Tubular ; Whole-mounts ; Bovine
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The spermatogonial stem cell line in prepubertal and adult bovine testis was studied by electron microscopy and protein gene product 9.5 immunohistochemistry. Three successive spermatogonia precursor cell configurations were observed. Small basal stem cells were found to possess a spherical shape and nuclei with two to three nucleoli. They were observed in prepubertal testes (25 and 30 weeks) and in low numbers during all the stages of the seminiferous epithelial cycle in the adult. Aggregated spermatogonia precursor cells are the dominating germ cell type in the 25-week-old and 30-week-old calf. In the adult seminiferous epithelium, they cause expansion of the basal tubular compartment as they form dense groups containing up to 15 cells. These groups are observed concomitantly with cycling A-spermatogonia and preleptotenes at the beginning of spermatocytogenesis. At the end of A-spermatogonia propagation, the aggregated spermatogonia precursor cells separate and intermingle with cycling A-spermatogonia. The spermatogonia precursor cells can later be found together with I-spermatogonia as members of an interconnected cellular network of medium-sized cells. When the I-spermatogonia divide to form the smaller B-spermatogonia, the precursor cells, which stay connected with the cycling spermatogonial population, pass through a growth phase. They can now be considered as committed spermatogonia precursor cells and are continuously being transformed into A1-spermatogonia to start a new round of spermatocytogenesis. Ultrastructurally, all members of the precursor cell line are similar. However, a number of features have been found to show a quantitative increase (endoplasmic reticulum, mitochondria) or to exhibit a rising degree of complexity (nucleolus) during the progression from basal stem cells to committed spermatogonia precursor cells.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00583394
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  • 41
    Electronic Resource
    Electronic Resource
    Immunocytochemical characterization of a new marker of fibrous and reactive astrocytes (1995)
    Springer
    Cell & tissue research 283 (1995), S. 39-49 
    Details
    ISSN: 1432-0878
    Keywords: Key words: Mab 6.17 ; Reactive astrocyte ; Diencephalon ; Spinal cord ; Confocal microscopy ; Ultrastructure ; Rat (Sprague Dawley)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. A specific monoclonal antiserum (Mab 6.17) inducing a strong immunostaining of the neuromuscular junction has been used to detect the possible occurrence of the corresponding antigen throughout the intact or lesioned central nervous system of adult rats. In intact animals, 6.17-immunolabeling was essentially detected in astrocyte-like structures located in white matter fasciculi of the brain, such as the optic tract, corpus callosum, fornix, and in the white matter of the spinal cord. The astroglial nature of such 6.17-immunolabeled profiles was verified by performing double or triple immunofluorescent labeling with Mab 6.17 and with specific antisera against astrocytic markers, such as S100 protein, glial fibrillary acidic protein and vimentin. In the white matter, all the structures reactive to Mab 6.17 were also reactive to antibodies against S100 protein, glial fibrillary acidic protein and vimentin. On the other hand, astrocytes of the grey matter that were immunoreactive to S100 and glial fibrillary acidic protein but negative to vimentin, were devoid of 6.17-immunoreactivity. After lesions including stab wound through the diencephalon or transection of the spinal cord, a marked increase of 6.17-immunostaining was noted in the regions surrounding the lesions. In these regions, 6.17-immunolabeling was associated with S100-, GFAP- and vimentin-positive astrocytes constituting the glial scar. The ultrastructural localization of 6.17-immunoreactivity indicated that, similar to glial fibrillary acidic protein and vimentin, the recognized antigen was mainly associated with gliofilaments. These observations indicate that, in the central nervous system of adult rats, Mab 6.17 recognizes a molecule associated with gliofilaments, which is essentially associated to reactive astrocytes expressing high levels of vimentin.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004410050510
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  • 42
    Electronic Resource
    Electronic Resource
    Ultrastructural and time-lapse observations of intraepithelial lymphocytes in the small intestine of the guinea pig: their possible role in the removal of effete enterocytes (1995)
    Springer
    Cell & tissue research 280 (1995), S. 491-497 
    Details
    ISSN: 1432-0878
    Keywords: Key words: Intestine ; small ; Intraepithelial lymphocytes ; Microcinematography ; Ultrastructure ; Guinea pig
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. In previous ultrastructural studies we have shown that at the tip of intestinal villi in guinea pigs, effete enterocytes are separated into two portions: a thin apical cytoplasm to be exfoliated into the lumen and a major basal portion to be ingested by lamina propria macrophages. During this process, intraepithelially disposed, large granular lymphocytes interdigitate with enterocytes in a complex manner. In the present study, the relation between the enterocytes and the lymphocytes in the villous epithelium of the guinea pig small intestine is described by use of transmission and scanning electron microscopy in an attempt to visualize the roles and activities of the lymphocytes more clearly. The lymphocytes project numerous pointed processes into effete enterocytes, even piercing them. Enterocytes are deeply indented or perforated, probably as a result of the encroaching lymphocyte processes. Some enterocytes are separated into apical and basal portions by numerous large excavations in the cytoplasm. These findings indicate that repeated perforating penetration of the lymphocytes induces cell cleavage. Supporting this supposition, our microcinematographic observations demonstrate the alternate protrusion and withdrawal of processes of lymphocytes. The processes advance with a pointed end, and subsequently, retract with a rounded end in a cycle of 8–18 seconds.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00318353
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  • 43
    Electronic Resource
    Electronic Resource
    Ultrastructural studies of the myenteric plexus and smooth muscle in organotypic cultures of the guinea-pig small intestine (1995)
    Springer
    Cell & tissue research 280 (1995), S. 627-637 
    Details
    ISSN: 1432-0878
    Keywords: Key words: Myenteric plexus ; Smooth muscle ; Organotypic culture ; Ultrastructure ; Intestine ; small ; Guinea-pig
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. External muscle and myenteric plexus from the small intestine of adult guinea-pigs were maintained in vitro for 3 or 6 days. Myenteric neurons and smooth muscle cells from such organotypic cultures were examined at the electron-microscopic level. An intact basal lamina was found around the myenteric ganglia and internodal strands. Neuronal membranes, nuclei and subcellular organelles appeared to be well preserved in cultured tissues and ribosomes were abundant. Dogiel type-II neurons were distinguishable by their elongated electron-dense mitochondria, numerous lysosomes and high densities of ribosomes. Vesiculated nerve profiles contained combinations of differently shaped vesicles. Synaptic membrane specializations were found between vesiculated nerve profiles and nerve processes and cell bodies. The majority of nerve fibres were well preserved in the myenteric ganglia, in internodal strands and in bundles running between circular muscle cells. No detectable changes were found in the ultrastructure of the somata and processes of glial cells. Longitudinal and circular muscle cells from cultured tissue had clearly defined membranes with some close associations with neighbouring muscle cells. Caveolae occurred in rows that ran parallel to the long axis of the muscle cells. These results indicate that the ultrastructural features of enteric neurons and smooth muscle of the guinea-pig small intestine are well preserved in organotypic culture.
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    URL: http://dx.doi.org/10.1007/BF00318365
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  • 44
    Electronic Resource
    Electronic Resource
    Seasonal changes in hepatocyte ultrastructure correlated with the cyclic synthesis of secretory proteins in the winter flounder (Pleuronectes americanus) (1995)
    Springer
    Cell & tissue research 281 (1995), S. 153-161 
    Details
    ISSN: 1432-0878
    Keywords: Liver ; Ultrastructure ; Antifreeze ; Proteins ; Secretion ; Lipid ; Flounder, Pleuronectes americanus (Teleostei)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Liver tissue was sampled from flounder (Pleuronectes americanus) throughout the year with the intention of documenting changes in the ultrastructure coincident with the production and secretion of antifreeze proteins. In the winter, hepatocytes are dedicated to the production of these proteins and, in the female, also reproductive proteins. In both sexes, liver cells in the summer contain abundant lipid and glycogen stores. In the female, there is a conspicuous hepatocyte transformation from a fat-filled cell in the summer to one with well-developed rough endoplasmic reticulum in the winter. Large amounts of rough endoplasmic reticulum (11.2 mg/gm) were recovered after subcellular fractionation of female wintertime liver. The increased appearance of secretory organelles and the high number of nucleolar profiles observed in winter animals is consistent with the elevated demand for protein secretion and synthesis in both sexes. The fractional volumes occupied by lipid droplets and mitochondria were different when comparisons were made between sex and season. Females contained a greater volume of lipid than did males, and summer animals contained more lipid than those in winter.
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    URL: http://dx.doi.org/10.1007/BF00307969
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  • 45
    Electronic Resource
    Electronic Resource
    Glycosaminoglycans in porcine lung: an ultrastructural study using Cupromeronic Blue (1995)
    Springer
    Cell & tissue research 281 (1995), S. 473-483 
    Details
    ISSN: 1432-0878
    Keywords: Key words: Glycosaminoglycans ; Cupromeronic Blue ; Lung ; Connective tissue ; Ultrastructure ; Pig
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. Glycosaminoglycans (GAGs) are essential components of the extracellular matrix contributing to the mechanical properties of connective tissues as well as to cell recognition and growth regulation. The ultrastructural localization of GAGs in porcine lung was studied by means of the dye Cupromeronic Blue in the presence of 0.3 M MgCl2 according to Scott’s critical electrolyte concentration technique. GAGs were observed in locations described as follows. Pleura: Dermatan sulphate (DS) and chondroitin sulphate (CS) attached in the region of the d-band of collagen fibrils, interconnecting the fibrils; heparan sulphate (HS) at the surface of elastic fibers and in the basement membrane of the mesothelium and blood vessels. Bronchial cartilage: Abundant amounts of GAGs were observed in three zones: pericellular, in the intercellular matrix and at the perichondrial collagen. By enzyme digestion a superficial cartilage layer with predominantly CS could be distinguished from a deep zone with CS and keratan sulphate. The structure of the large aggregating cartilage proteoglycan was confirmed in situ. Airway epithelium: HS at the whole surface of cilia and microvilli and in the basement membrane of the epithelial cells. Alveolar wall: CS/DS at collagen fibrils, HS at the surface of elastic fibers and in the basement membranes of epithelium and endothelium.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004410050442
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  • 46
    Electronic Resource
    Electronic Resource
    Glycosaminoglycans in porcine lung: an ultrastructural study using Cupromeronic Blue (1995)
    Springer
    Cell & tissue research 281 (1995), S. 473-483 
    Details
    ISSN: 1432-0878
    Keywords: Glycosaminoglycans ; Cupromeronic Blue ; Lung ; Connective tissue ; Ultrastructure ; Pig
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Glycosaminoglycans (GAGs) are essential components of the extracellular matrix contributing to the mechanical properties of connective tissues as well as to cell recognition and growth regulation. The ultrastructural localization of GAGs in porcine lung was studied by means of the dye Cupromeronic Blue in the presence of 0.3 M MgCl2 according to Scott's critical electrolyte concentration technique. GAGs were observed in locations described as follows. Pleura: Dermatan sulphate (DS) and chondroitin sulphate (CS) attached in the region of the d-band of collagen fibrils, interconnecting the fibrils; heparan sulphate (HS) at the surface of elastic fibers and in the basement membrane of the mesothelium and blood vessels. Bronchial cartilage: Abundant amounts of GAGs were observed in three zones: pericellular, in the intercellular matrix and at the perichondrial collagen. By enzyme digestion a superficial cartilage layer with predominantly CS could be distinguished from a deep zone with CS and keratan sulphate. The structure of the large aggregating cartilage proteoglycan was confirmed in situ. Airway epithelium: HS at the whole surface of cilia and microvilli and in the basement membrane of the epithelial cells. Alveolar wall: CS/DS at collagen fibrils, HS at the surface of elastic fibers and in the basement membranes of epithelium and endothelium.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00417864
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  • 47
    Electronic Resource
    Electronic Resource
    The larval development of lateral musculature in gilthead sea bream Sparus aurata and sea bass Dicentrarchus labrax (1995)
    Springer
    Cell & tissue research 280 (1995), S. 217-224 
    Details
    ISSN: 1432-0878
    Keywords: Ultrastructure ; Muscle growth ; Hypertrophy ; Hyperplasia ; Histochemistry ; Fish ; Sparus aurata, Dicentrarchus labrax (Teleostei)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Fibre-type differentiation of the lateral musculature has been studied in Sparus aurata (L.) and Dicentrarchus labrax (L.) during larval development. Histochemical and ultrastructural techniques show two presumptive muscle layers and two germinative zones of presumptive myoblasts. At hatching, myotomal muscle consists of a monolayer of thin undifferentiated cells near the skin (first germinative zone) overlying another mono-layer of small diameter fibres extending hypaxially and epaxially away from the transverse septum. Below this, there is a much thicker, deep layer of fibres, generally large in diameter and polygonal in shape. The presumptive myoblasts are located between these two layers of fibres in the second germinative zone. Initially, the superficial and deep muscle fibres show high and low myosin ATPase activity, respectively. Both layers grow by generating new fibres from the two mentioned germinative zones. At the end of larval life, the superficial layer changes its histochemical profile from high to low myosin ATPase activity and, at the same time, intermediate or pink muscle fibres can be observed by oxidative activity (the NADH-TR reaction). Morphometric analysis shows a significant increase in mean fibre diameter during successive ages, as shown by the Student's t-test (hypertrophic growth). Skewness and kurtosis values of fibre diameters point to the generation of a new fibre population from the germinative zones (hyperplastic growth).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00307792
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  • 48
    Electronic Resource
    Electronic Resource
    Ultrastructural and time-lapse observations of intraepithelial lymphocytes in the small intestine of the guinea pig: their possible role in the removal of effete enterocytes (1995)
    Springer
    Cell & tissue research 280 (1995), S. 491-497 
    Details
    ISSN: 1432-0878
    Keywords: Intestine, small ; Intraepithelial lymphocytes ; Microcinematography ; Ultrastructure ; Guinea pig
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract In previous ultrastructural studies we have shown that at the tip of intestinal villi in guinea pigs, effete enterocytes are separated into two portions: a thin apical cytoplasm to be exfoliated into the lumen and a major basal portion to be ingested by lamina propria macrophages. During this process, intraepithelially disposed, large granular lymphocytes interdigitate with enterocytes in a complex manner. In the present study, the relation between the enterocytes and the lymphocytes in the villous epithelium of the guinea pig small intestine is described by use of transmission and scanning electron microscopy in an attempt to visualize the roles and activities of the lymphocytes more clearly. The lymphocytes project numerous pointed processes into effete enterocytes, even piercing them. Enterocytes are deeply indented or perforated, probably as a result of the encroaching lymphocyte processes. Some enterocytes are separated into apical and basal portions by numerous large excavations in the cytoplasm. These findings indicate that repeated perforating penetration of the lymphocytes induces cell cleavage. Supporting this supposition, our microcinematographic observations demonstrate the alternate protrusion and withdrawal of processes of lymphocytes. The processes advance with a pointed end, and subsequently, retract with a rounded end in a cycle of 8–18 seconds.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00318353
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  • 49
    Electronic Resource
    Electronic Resource
    Ultrastructural studies of the myenteric plexus and smooth muscle in organotypic cultures of the guinea-pig small intestine (1995)
    Springer
    Cell & tissue research 280 (1995), S. 627-637 
    Details
    ISSN: 1432-0878
    Keywords: Myenteric plexus ; Smooth muscle ; Organotypic culture ; Ultrastructure ; Intestine, small ; Guinea-pig
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract External muscle and myenteric plexus from the small intestine of adult guinea-pigs were maintained in vitro for 3 or 6 days. Myenteric neurons and smooth muscle cells from such organotypic cultures were examined at the electron-microscopic level. An intact basal lamina was found around the myenteric ganglia and internodal strands. Neuronal membranes, nuclei and subcellular organelles appeared to be well preserved in cultured tissues and ribosomes were abundant. Dogiel type-II neurons were distinguishable by their elongated electron-dense mitochondria, numerous lysosomes and high densities of ribosomes. Vesiculated nerve profiles contained combinations of differently shaped vesicles. Synaptic membrane specializations were found between vesiculated nerve profiles and nerve processes and cell bodies. The majority of nerve fibres were well preserved in the myenteric ganglia, in internodal strands and in bundles running between circular muscle cells. No detectable changes were found in the ultrastructure of the somata and processes of glial cells. Longitudinal and circular muscle cells from cultured tissue had clearly defined membranes with some close associations with neighbouring muscle cells. Caveolae occurred in rows that ran parallel to the long axis of the muscle cells. These results indicate that the ultrastructural features of enteric neurons and smooth muscle of the guinea-pig small intestine are well preserved in organotypic culture.
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    URL: http://dx.doi.org/10.1007/BF00318365
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  • 50
    Electronic Resource
    Electronic Resource
    Seasonal changes in hepatocyte ultrastructure correlated with the cyclic synthesis of secretory proteins in the winter flounder (Pleuronectes americanus) (1995)
    Springer
    Cell & tissue research 281 (1995), S. 153-161 
    Details
    ISSN: 1432-0878
    Keywords: Key words: Liver ; Ultrastructure ; Antifreeze ; Proteins ; Secretion ; Lipid ; Flounder ; Pleuronectes americanus (Teleostei)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. Liver tissue was sampled from flounder (Pleuronectes americanus) throughout the year with the in-tention of documenting changes in the ultrastructure coincident with the production and secretion of antifreeze proteins. In the winter, hepatocytes are dedicated to the production of these proteins and, in the female, also reproductive proteins. In both sexes, liver cells in the summer contain abundant lipid and glycogen stores. In the female, there is a conspicuous hepatocyte transformation from a fat-filled cell in the summer to one with well- developed rough endoplasmic reticulum in the winter. Large amounts of rough endoplasmic reticulum (11.2 mg/gm) were recovered after subcellular fractionation of female wintertime liver. The increased appearance of secretory organelles and the high number of nucleolar profiles observed in winter animals is consistent with the elevated demand for protein secretion and synthesis in both sexes. The fractional volumes occupied by lipid droplets and mitochondria were different when comparisons were made between sex and season. Females contained a greater volume of lipid than did males, and summer animals contained more lipid than those in winter.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00307969
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  • 51
    Electronic Resource
    Electronic Resource
    Ultrastructural characterization of the sexually dimorphic medial preoptic nucleus of male Japanese quail (1995)
    Springer
    Cell & tissue research 279 (1995), S. 517-527 
    Details
    ISSN: 1432-0878
    Keywords: Key words: Avian brain ; Preoptic nucleus ; Sexual behaviour ; Ultrastructure ; Sexual dimorphism ; Coturnix japonica (Aves ; Phasianiformes)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. The medial preoptic nucleus is a sexually dimorphic structure whose cytoarchitecture, afferent and efferent connections, and functions have been previously described. No detailed ultrastructural study has, however, been perfomed to date. Here we describe the ultrastructural organization of this important preoptic structure of the male quail. Neuronal cell bodies of the medial preoptic nucleus generally show extensive development of protein-synthesis-related organelles (rough endoplasmic reticulum, polysomes), and of secretory structures (Golgi complexes, secretory vesicles, dense bodies). Previous morphometrical studies at the light-microscopical level have demonstrated the presence of a medial and a lateral neuronal population distinguished by the size of their cell bodies (the medial neurons are smaller than the lateral neurons). The present ultrastructural investigation confirms the difference in size, but no difference has been observed in the ultrastructural organization of the neurons. In both the medial and the lateral part, the nucleus is characterized by a large variety of cell bodies, including some that, on the basis of their ultrastructure, can be considered as putative peptidergic neurons. Close contacts are frequently observed between adjacent cell bodies that are normally arranged in clusters. Various types of synaptic endings are also present, suggesting a rich supply of nerve fibers. A few glial cells are scattered within the nucleus. In view of the crucial role of this region in regulating quail sexual behavior, the large heterogeneity of neurons and of afferent nervous fibers suggest that this region might have an important role in the integration of information arriving from different brain regions.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004410050311
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  • 52
    Electronic Resource
    Electronic Resource
    Fine structural study of interstitial cells associated with the deep muscular plexus of the rat small intestine, with special reference to the intestinal pacemaker cells (1995)
    Springer
    Cell & tissue research 282 (1995), S. 129-134 
    Details
    ISSN: 1432-0878
    Keywords: Small intestine ; Pacemaker ; Interstitial cell ; Ultrastructure ; Rat (Wistar)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Two types of interstitial cells have been demonstrated in close association in the deep muscular plexus of rat small intestine, by electron microscopy. Cells of the first type are characterized by a fibroblastic ultrastructure, i.e. a well-developed granular endoplasmic reticulum, Golgi apparatus and absence of the basal lamina. They form a few small gap junctions with the circular muscle cells and show close contact with axon terminals containing many synaptic vesicles. They may play a role in conducting electrical signals in the muscle tissue. Cells of the second type are characterized by many large gap junctions that interconnect with each other and with the circular muscle cells. Their cytoplasm is rich in cell organells, including mitochondria, granular endoplasmic reticulum and Golgi apparatus. They show some resemblance to the smooth muscle cells and have an incomplete basal lamina, caveolae and subsurface cisterns. However, they do not contain an organized contractile apparatus, although many intermediate filaments are present in their processes. They also show close contacts with axon terminals containing synaptic vesicles. These gap-junction-rich cells may be regular components of the intestinal tract and may be involved in the pacemaking activity of intestinal movement.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00319139
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  • 53
    Electronic Resource
    Electronic Resource
    Ultrastructural study of the presence of vasoactive intestinal polypeptide and serotonin in mucosal nerve fibres and endocrine cells of the intestine of goldfish (Carassius auratus) and tilapia (Oreochromis mossambicus) (1995)
    Springer
    Cell & tissue research 283 (1995), S. 143-150 
    Details
    ISSN: 1432-0878
    Keywords: Key words: Vasoactive intestinal polypeptide (VIP) ; Serotonin ; Ultrastructure ; Immunogold label ; Mucosal nerves ; Goldfish ; Carassius auratus ; Tilapia ; Oreochromis mossambicus (Teleostei)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. In order to establish a possible role of vasoactive intestinal polypeptide (VIP) and serotonin as (neuro)transmitters involved in the regulation of fish intestinal epithelium, we studied the presence of VIP and serotonin at the ultrastructural level in the intestinal mucosa of tilapia and goldfish. A low percentage of varicosities near the basal membrane of the tilapia intestinal epithelium was found to label for VIP or for serotonin, whereas in the goldfish, this percentage was much higher. The varicosities usually contained large granular and small clear vesicles. Immunogold labeling indicated that serotonin and VIP were localized in the large granular vesicles. Unlabeled large granular vesicles and small clear vesicles were usually also present in varicosities with serotonin- or VIP-labeled vesicles. In the goldfish, the serotonin-labeled varicosities were close to the epithelial cells, and direct contacts between serotonin-labeled nerve fibres and epithelial cells could sometimes be visualized. However, synaptic membrane specializations were never observed. In tilapia, the distance between the VIP- or serotonin-labeled varicosities and the epithelial cells was large (more than 2 μm).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004410050522
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  • 54
    Electronic Resource
    Electronic Resource
    Fine structural study of interstitial cells associated with the deep muscular plexus of the rat small intestine, with special reference to the intestinal pacemaker cells (1995)
    Springer
    Cell & tissue research 282 (1995), S. 129-134 
    Details
    ISSN: 1432-0878
    Keywords: Key words: Small intestine ; Pacemaker ; Interstitial cell ; Ultrastructure ; Rat (Wistar)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. Two types of interstitial cells have been demonstrated in close association in the deep muscular plexus of rat small intestine, by electron microscopy. Cells of the first type are characterized by a fibroblastic ultrastructure, i.e. a well-developed granular endoplasmic reticulum, Golgi apparatus and absence of the basal lamina. They form a few small gap junctions with the circular muscle cells and show close contact with axon terminals containing many synaptic vesicles. They may play a role in conducting electrical signals in the muscle tissue. Cells of the second type are characterized by many large gap junctions that interconnect with each other and with the circular muscle cells. Their cytoplasm is rich in cell organells, including mitochondria, granular endoplasmic reticulum and Golgi apparatus. They show some resemblance to the smooth muscle cells and have an incomplete basal lamina, caveolae and subsurface cisterns. However, they do not contain an organized contractile apparatus, although many intermediate filaments are present in their processes. They also show close contacts with axon terminals containing synaptic vesicles. These gap-junction-rich cells may be regular components of the intestinal tract and may be involved in the pacemaking activity of intestinal movement.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00319139
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  • 55
    Electronic Resource
    Electronic Resource
    Differences in synaptic output between excitatory and inhibitory motoneurons in a crayfish muscle (1995)
    Springer
    Cell & tissue research 280 (1995), S. 513-518 
    Details
    ISSN: 1432-0878
    Keywords: Axo-axonal synapse ; Neuromuscular synapse ; Motoneuron ; Ultrastructure ; Procambarus clarkii (Crustacea)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract A pair of antagonistic motoneurons, one excitatory and one inhibitory, innervates the distal accessory flexor muscle in the walking limb of the crayfish Procambarus clarkii. The number and size of synapses formed by these two axons on the muscle fibers (neuromuscular synapses) and on each other (axo-axonal synapses) were estimated using thin-section electron microscopy. Although profiles of nerve terminals of the two axons occur in roughly equal proportions, the frequency of occurrence of neuromuscular synapses differed markedly: 73% were excitatory and 27% were inhibitory. However, inhibitory synapses were 4–5 times larger than excitatory ones, and consequently, the total contact areas devoted to neuromuscular synapses were similar for both axons. Axo-axonal synapses were predominantly from the inhibitory axon to the excitatory axon (86%), and a few were from the excitatory axon to the inhibitory axon (14%). The role of the inhibitory axo-axonal synapse is presynaptic inhibition, but that of the excitatory axo-axonal synapse is not known. The differences in size of neuromuscular synapses between the two axons may reflect intrinsic determinants of the neuron, while the similarity in total synaptic area may reflect retrograde influences from the muscle for regulating synapse number.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00318355
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  • 56
    Electronic Resource
    Electronic Resource
    Ultrastructural localisation of NADPH-diaphorase in the chick thymic medulla (1995)
    Springer
    Cell & tissue research 279 (1995), S. 405-409 
    Details
    ISSN: 1432-0878
    Keywords: NADPH-diaphorase ; Nitric oxide ; Thymic medulla ; Ultrastructure ; Chick
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Nicotinamide-adenine-dinucleotide phosphate-diaphorase positive cells in the chick thymus were studied at the electron-microscopic level. The formazan, a marker for the enzyme nitric oxide synthase, labelled cystic, undifferentiated, endocrine-like and myoid cells in the medulla. Some lymphoid and reticulo-epithelial cells were also lightly labelled. The reaction product was predominantly bound to the membranes of the endoplasmic reticulum in all the cells labelled and also to the nuclear envelope and outer membrane of mitochondria. The Golgi apparatus and the plasma membrane were free of the reaction product.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00318498
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  • 57
    Electronic Resource
    Electronic Resource
    Ultrastructural localisation of NADPH-diaphorase in the chick thymic medulla (1995)
    Springer
    Cell & tissue research 279 (1995), S. 405-409 
    Details
    ISSN: 1432-0878
    Keywords: Key words: NADPH-diaphorase ; Nitric oxide ; Thymic medulla ; Ultrastructure ; Chick
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. Nicotinamide-adenine-dinucleotide phosphate-diaphorase positive cells in the chick thymus were studied at the electron-microscopic level. The formazan, a marker for the enzyme nitric oxide synthase, labelled cystic, undifferentiated, endocrine-like and myoid cells in the medulla. Some lymphoid and reticulo-epithelial cells were also lightly labelled. The reaction product was predominantly bound to the membranes of the endoplasmic reticulum in all the cells labelled and also to the nuclear envelope and outer membrane of mitochondria. The Golgi apparatus and the plasma membrane were free of the reaction product.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004410050297
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  • 58
    Electronic Resource
    Electronic Resource
    Ultrastructural characterization of the sexually dimorphic medial preoptic nucleus of male Japanese quail (1995)
    Springer
    Cell & tissue research 279 (1995), S. 517-527 
    Details
    ISSN: 1432-0878
    Keywords: Avian brain ; Preoptic nucleus ; Sexual behaviour ; Ultrastructure ; Sexual dimorphism ; coturnix japonica (Aves, Phasianiformes)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The medial preoptic nucleus is a sexually dimorphic structure whose cytoarchitecture, afferent and efferent connections, and functions have been previously described. No detailed ultrastructural study has, however, been perfomed to date. Here we describe the ultrastructural organization of this important preoptic structure of the male quail. Neuronal cell bodies of the medial preoptic nucleus generally show extensive development of protein-synthesis-related organelles (rough endoplasmic reticulum, polysomes), and of secretory structures (Golgi complexes, secretory vesicles, dense bodies). Previous morphometrical studies at the light-microscopical level have demonstrated the presence of a medial and a lateral neuronal population distinguished by the size of their cell bodies (the medial neurons are smaller than the lateral neurons). The present ultrastructural investigation confirms the difference in size, but no difference has been observed in the ultrastructural organization of the neurons. In both the medial and the lateral part, the nucleus is characterized by a large variety of cell bodies, including some that, on the basis of their ultrastructure, can be considered as putative peptidergic neurons. Close contacts are frequently observed between adjacent cell bodies that are normally arranged in clusters. Various types of synaptic endings are also present, suggesting a rich supply of nerve fibers. A few glial cells are scattered within the nucleus. In view of the crucial role of this region in regulating quail sexual behavior, the large heterogeneity of neurons and of afferent nervous fibers suggest that this region might have an important role in the integration of information arriving from different brain regions.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00318164
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  • 59
    Electronic Resource
    Electronic Resource
    Immunogold labelling of estradiol receptor in MCF7 cells (1995)
    Springer
    Cell & tissue research 279 (1995), S. 445-452 
    Details
    ISSN: 1432-0878
    Keywords: Key words: Estradiol receptor ; Breast cancer cells ; Cell culture ; Ultrastructure ; Electron microscopy ; Immunohistochemistry ; Human
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. The distribution of estradiol receptor in serial sections of estradiol-deprived and estradiol-stimulated MCF7 cells was studied by using mouse monoclonal antibodies reacting with different domains of the receptor and goat-antimouse IgG/6 nm gold. In the nucleus and the cytoplasm of estradiol-deprived cells, the receptor was detected by all three monoclonals (13H2, HT 65 and MA1-310). The antibodies 13H2 and MA1-310 detected receptor associated to the microfilament bundles in the cytoplasm. Higher densities of antireceptor attachment to the nuclear areas were accompanied by a reduction in the attachment to the cytoplasm after estradiol stimulation of the cells. The results confirm earlier observations on the presence of cytoplasmic estrogen receptor in estradiol-deprived cells and support the premise of an es- tradiol-induced translocation of this ligand-dependent transcription regulator.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004410050303
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  • 60
    Electronic Resource
    Electronic Resource
    Immunogold labelling of estradiol receptor in MCF7 cells (1995)
    Springer
    Cell & tissue research 279 (1995), S. 445-452 
    Details
    ISSN: 1432-0878
    Keywords: Estradiol receptor ; Breast cancer cells ; Cell culture ; Ultrastructure ; Electron microscopy ; Immunohistochemistry ; Human
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The distribution of estradiol receptor in serial sections of estradiol-deprived and estradiol-stimulated MCF7 cells was studied by using mouse monoclonal antibodies reacting with different domains of the receptor and goat-antimouse IgG/6 nm gold. In the nucleus and the cytoplasm of estradiol-deprived cells, the receptor was detected by all three monoclonals (13H2, HT 65 and MA1-310). The antibodies 13H2 and MA1-310 detected receptor associated to the microfilament bundles in the cytoplasm. Higher densities of antireceptor attachment to the nuclear areas were accompanied by a reduction in the attachment to the cytoplasm after estradiol stimulation of the cells. The results confirm earlier observations on the presence of cytoplasmic estrogen receptor in estradiol-deprived cells and support the premise of an estradiol-induced translocation of this ligand-dependent transcription regulator.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00318156
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  • 61
    Electronic Resource
    Electronic Resource
    Cells of the photoreceptor line in the pineal organ of an adult marsupial, Didelphis albiventris (1995)
    Springer
    Cell & tissue research 282 (1995), S. 363-366 
    Details
    ISSN: 1432-0878
    Keywords: Pineal organ ; Pinealocytes ; Secretory rudimentary photoreceptors ; Ultrastructure ; Didelphis albiventris (Marsupialia)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract We report the presence of atypical pinealocytes as components of epiphyseal follicles in the adult South American opossum Didelphis albiventris. Their main characteristic is a bulbous-shaped apical cytoplasmic extension which protrudes towards the follicular lumen among the microvilli and cilia of neighbouring ependymal cells. They resemble the photoreceptor-like pinealocytes of sauropsids and developing photoreceptors in the retina of newborn mammals. Morphological characteristics enable us to classify them as cells of the receptor line.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00319126
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  • 62
    Electronic Resource
    Electronic Resource
    Cells of the photoreceptor line in the pineal organ of an adult marsupial, Didelphis albiventris (1995)
    Springer
    Cell & tissue research 282 (1995), S. 363-366 
    Details
    ISSN: 1432-0878
    Keywords: Key words: Pineal organ ; Pinealocytes ; Secretory rudimentary photoreceptors ; Ultrastructure ; Didelphis albiventris (Marsupialia)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. We report the presence of atypical pinealo-cytes as components of epiphyseal follicles in the adult South American opossum Didelphis albiventris. Their main characteristic is a bulbous-shaped apical cytoplasmic extension which protrudes towards the follicular lumen among the microvilli and cilia of neighbouring ependymal cells. They resemble the photoreceptor-like pinealocytes of sauropsids and developing photoreceptors in the retina of newborn mammals. Morphological characteristics enable us to classify them as cells of the receptor line.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004410050487
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  • 63
    Electronic Resource
    Electronic Resource
    Comparative anatomy and ultrastructure of active and dormant vascular cambium in rhizome ofBotrychium ternatum (1995)
    Springer
    Journal of plant research 108 (1995), S. 149-159 
    Details
    ISSN: 1618-0860
    Keywords: Anatomy ; Botrychium ternatum ; Rhizome ; Ultrastructure ; Vascular cambium
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Vascular cambium ofBotrychium ternatum rhizome varied according to age, position and season was studied by light and electron microscopy. Cambium at the 6th internode (6-year-old cambium) had the greatest number of active cambial cells in August and September, thus it was in the most active stage. The active cells were characterized by the presence of a large vacuole, few storage materials such as starch grains within plastids or lipid droplets, a thin tangential wall; and various cell organelles in the thin peripheral layer of cytoplasm. When the 6-year-old cambium reached its dormant season after November, the dormant cells were filled with numerous storage materials and had few cell organelles. Our observations suggested that the initiation and cessation of cambial activity may be correlated with the annual life cycle of this plant: the vegetative and reproductive leaves began to emerge in June and July, respectively, and the sporophyll withered in November after the spore dispersal. Most cambial cells at the 10th internode, which remained in a dormant state throughout the year, were filled with numerous storage materials. Our results indicated that the activity of vascular cambium in the 10th internode was determinate.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02344339
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  • 64
    Electronic Resource
    Electronic Resource
    Cellular changes during the acquisition of embryogenic potential in isolated pollen grains ofNicotiana tabacum (1995)
    Springer
    Protoplasma 186 (1995), S. 220-230 
    Details
    ISSN: 1615-6102
    Keywords: Embryogenesis ; In vitro culture ; Isolated pollen ; Nicotiana tabacum ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary We used electron microscopical techniques to study ultrastructural changes during the acquisition of embryogenic competence in immature pollen grains ofNicotiana tabacum, isolated at the early- or mid-bicellular stage and cultured in vitro under starvation conditions. Cytoplasmic and nuclear changes during the starvation treatment are reported. Dedifferentiation of plastids, dilation of the wall of the generative cell, the appearance of a large vacuole, loss of nuclear pores in the vegetative nucleus, changes in chromatin and nucleolar structure, and a decrease in the size of the nucleolus were observed. We suggest that these events are the first step in the switch from generative to vegetative generation during pollen embryogenesis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01281332
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  • 65
    Electronic Resource
    Electronic Resource
    Accumulation of vismione A in regenerated plants ofVismia guianensis DC (1995)
    Springer
    Protoplasma 189 (1995), S. 9-16 
    Details
    ISSN: 1615-6102
    Keywords: Metabolite accumulation ; Vismia guianensis ; Callus cultures ; Plant regeneration ; Ultrastructure ; Histochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The accumulation and tissue localization of antitumoral vismione A in the in vitro regenerated plants ofVismia guianensis DC. were investigated. Chemical and light and electron-microscope analyses revealed that vismione A, detected as phenolic black globules in the vacuoles, was accumulated in the leaf, mainly in the palisade, and in small amounts in the primary body of the stem (epidermis and first cortical layer). Vismione A is neither present in the secretory cavities and ducts of the leaf nor in the secretory ducts of the stem. In the leaves of the regenerated plants, the amount of vismione A reached 0.5% FW, compared to 0.1% in the leaves of the parent plant. The optimization of the in vitro regeneration of plants was obtained in MS medium enriched with BAP (1 ppm). The best results for the rooting of regenerated plants were achieved with MS medium containing half-strength salts and 10−5 MIBA.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01280287
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  • 66
    Electronic Resource
    Electronic Resource
    Low-density lipoproteins inhibit histamine and NaNO2 relaxations of the coronary vasculature and reduce contractile function in isolated rat hearts (1995)
    Springer
    Heart and vessels 10 (1995), S. 249-257 
    Details
    ISSN: 1615-2573
    Keywords: LDL ; Rat heart ; Ultrastructure ; Coronary vasculature ; Contractile function
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In the present study we examined the action of native and oxidized low-density lipoproteins (LDL) on coronary vascular and cardiac function and ultrastructure in rat hearts perfused isovolumically in the Langendorff mode. Responses of the coronary resistance vessels to the endothelium-dependent vasodilator, histamine, and the endothelium-independent vasodilator, NaNO2, were measured together with contractile function (rate-pressure product) before and after perfusion for 20 min with native — or oxidized-LDL at a concentration of 100 µg protein/ml. Ultrastructural damage was assessed via electron microscopy of perfusion-fixed heart specimens. When compared to findings in untreated, control hearts, both native and oxidized LDL significantly reduced the responsiveness of the coronary resistance vessels to histamine and NaNO2, by about 50%. The rate-pressure product was decreased more by oxidized-LDL (41%) than by native-LDL (26%). Electron microscopy showed no ultrastructural abnormalities in the vasculature or myocytes of control hearts. The administration of both native- and oxidized-LDL caused distortion of endothelial cells, increased levels of pinocytotic vesicles in both endothelial and smooth muscle cells, detachment of blood vessels from surrounding tissue, and some regions of myocyte injury with evidence of mitochondrial injury and fluid accumulation. Our results show that both native- and oxidized-LDL are toxic to the isolated heart preparation. They inhibit coronary vascular responsiveness to vasodilators, reduce contractile function, and produce damage to cardiac ultrastructure.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01744904
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  • 67
    Electronic Resource
    Electronic Resource
    Usefulness of electron microscopy in the diagnosis of cardiac sarcoidosis (1995)
    Springer
    Heart and vessels 10 (1995), S. 275-278 
    Details
    ISSN: 1615-2573
    Keywords: Sarcoidosis ; Heart ; Endomyocardial biopsy ; Epithelioid cell ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A 49-year-old man with cardiac sarcoidosis is presented. He suffered from congestive heart failure, and left ventricular asynergy and reduced function was evident by echocardiogram and left ventriculogram. A light microscopic examination of the endomyocardial biopsy revealed nonspecific myocarditis without giant cells or noncaseating granulomas. Under an electron microscope, however, several epithelioid cells were found in the specimen. The serum level of lysozyme was elevated. The patient had a past history of sarcoidosis of the eyes and lungs 22 years previously. Cardiac diseases presenting epithelioid cells other than sarcoidosis were clinically ruled out. Thus, the diagnosis of cardic sarcoidosis was made based on both clinical and ultrastructural findings, and corticosteroid therapy was initiated. In the second biopsy, performed 4 months later, a noncaseating granuloma was found. Generally, the incidence of histological diagnosis of cardiac sarcoidosis by light microscopy is relatively low in endomyocardial biopsy specimens. The present case suggests that the addition of an ultrastructural examination may improve the diagnostic usefulness of the endomyocardial biopsy in cardiac sarcoidosis, since electron microscopy can clearly identify the presence of even one epithelioid cell.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01744907
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  • 68
    Electronic Resource
    Electronic Resource
    Ultrastructural studies on the embryo sac ofViscum minimum I. Megasporogenesis (1995)
    Springer
    Protoplasma 185 (1995), S. 93-105 
    Details
    ISSN: 1615-6102
    Keywords: Embryo sac ; Embryogenesis ; Megasporogenesis ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Changes taking place during megasporogenesis of a mistletoe (Viscum minimum) were examined at both light and electron microscopy levels. No distinct ovules, integuments, or ovarian cavity are present at any stage of development. The multicellular archesporium originates in the center of a solid ovary. Several functional megasporocytes are developed from the archesporial cells, either adjacent to each other or separated by unspecialized cells. The megasporocyte is much larger than surrounding cells, is invested by a thick wall, and possesses a large nucleus and amyloplasts. Although plasmodesmata are absent even between the adjacent megasporocytes, cells enter meiosis simultaneously. Following meiosis a linear tetrad is formed. Double and treble linear tetrads are frequently observed. The development of the embryo sac conforms to the monosporic or Polygonum type of megasporogenesis. However, the bisporic or Allium type of development is occasionally observed in preparations. Factors determining the pattern of development are discussed. As in other plant species which follow the monosporic type of development, only one functional megaspore cell undergoes further development while others degenerate. Unlike the healthy functional megaspore cell, the degenerating cells have large starch grains and electron-dense cytoplasm. At a later stage of development, the degraded cells are absorbed by the surrounding tissue.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01272757
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  • 69
    Electronic Resource
    Electronic Resource
    Endoplasmic reticulum as a storage site for allergenic proteins in pollen grains of several Oleaceae (1995)
    Springer
    Protoplasma 187 (1995), S. 111-116 
    Details
    ISSN: 1615-6102
    Keywords: Allergenic protein ; Oleaceae ; Pollen ; Endoplasmic reticulum ; Immuno-localization ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The ultrastructure of mature pollen grains of several Oleaceae species (Olea europaea, Fraxinus excelsior, Syringa vulgaris, Ligustrum vulgare, andForsythia suspensa) was studied and the immunolocalization of Ole e I, the major allergen of olige pollen, was determined by immunogold labelling. The five Oleaceae pollens studied here showed different intensities of labelling. The Ole e I allergen was localized throughout the rough endoplasmic reticulum. The absence of gold particles in other cell compartments, such as nuclei, pastids, mitochondria, dictyosomes, lipid bodies, and cell wall, as well as the absence of labelling in control preparations, indicate the specificity of immunolocalization. We conclude that endoplasmic reticulum of the mature pollen grain is a storage site for allergenic proteins and is probably also involved in their synthesis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01280238
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  • 70
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    Electronic Resource
    Electron microscopic studies onNosema mesnili Paillot (Microsporidia: Nosematidae) infecting the Malpighian tubules ofPieris canidia larva (1995)
    Springer
    Protoplasma 186 (1995), S. 142-148 
    Details
    ISSN: 1615-6102
    Keywords: Pieris canidia ; Nosema mesnili ; Microsporidia ; Lepidoptera ; Pieridae ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The ultrastructure of a microsporidiumNosema mesnili found in the Malpighian tubules ofPieris canidia is described. The life cycle includes meronts, sporonts, sporoblasts, and spores, with typical diplokaryon in each stage. The first two stages are amorphous forms with the former having a thinner cell wall. The spore has 11 coils of the polar filament. This protozoan is a chronic pathogen to its insect host and might have potential as a biological control agent.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01281324
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    Ultrastructure of microsporogenesis and microgametogenesis inArabidopsis thaliana (L.) Heynh. ecotype Wassilewskija (Brassicaceae) (1995)
    Springer
    Protoplasma 185 (1995), S. 7-21 
    Details
    ISSN: 1615-6102
    Keywords: Arabidopsis thaliana ; Microgametogenesis ; Microsporogenesis ; Pollen development ; Tapetal cells ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The process of microsporogenesis and microgametogenesis was studied at the ultrastructural level in wild-typeArabidopsis thaliana ecotype Wassilewskija to provide a basis for comparison with nuclear male-sterile mutants of the same ecotype. From the earliest stage studied to mature pollen just prior to anther dehiscence, microsporocyte/microspore/pollen development follows the general pattern seen in most angiosperms. The tapetum is of the secretory type with loss of the tapetal cell walls beginning at about the time of microsporocyte meiosis. Wall loss exhibits polarity with the tapetal protoplasts becoming located at a distance from the inner tangential walls first, followed by an increase in distance from the radial walls beginning at the interior edge and progressing outward. The inner tangential and radial tapetal walls are completely degenerated by the microspore tetrad stage. Unlike other members of the Brassicaceae that have been studied, the tapetal cells ofA. thaliana Wassilewskija also lose their outer tangential walls, and secretion occurs from all sides of the cells. Exine wall precursors are secreted from the tapetal cells in a process that appears to involve dilation of individual endoplasmic reticulum cisternae that fuse with the tapetal cell membrane and release their contents into the locule. Following completion of the exine, the tapetal cell plastids develop membranebound inclusions with osmiophilic and electron-transparent regions. The plastids undergo ultrastructural changes that suggest breakdown of the inclusion membranes followed by release of their contents into the locule prior to the complete degeneration of the tapetal cells.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01272749
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    Early cellular events during induction of carrot explants with 2,4-D (1995)
    Springer
    Protoplasma 185 (1995), S. 28-36 
    Details
    ISSN: 1615-6102
    Keywords: Carrot hypocotyl explant ; Flow cytometry ; Somatic embryogenesis ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The cellular events occurring in carrot hypocotyl explants during long-term and pulse treatment with 2,4-D were followed using different techniques (light and transmission electron microscopy, flow cytometry, PCNA staining). Different morphogenetic pathways were induced under the various experimental conditions. Nevertheless, in the explants the activated cells were the same (provascular cells) and they showed very similar structural and ultrastructural changes. The long-term treatment with 2,4-D induced rapid re-activation of the cell cycle.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01272751
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  • 73
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    Cellular changes during heat shock induction and embryo development of cultured microspores ofBrassica napus cv. Topas (1995)
    Springer
    Protoplasma 185 (1995), S. 106-112 
    Details
    ISSN: 1615-6102
    Keywords: Brassica napus ; Embryogenesis ; Heat shock ; Induction ; Microspore embryogenesis ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Brassica napus cv. Topas microspores, isolated and cultured near the time of the first pollen mitosis and subjected to a heat treatment of 24 h, can be induced to develop into haploid embryos. This is a study of microspore structure during induction and embryo determination. Early during the 32.5 °C incubation period the nucleus moved away from the edge of the cell, and granules, 30 to 60 nm in diameter, appeared in the mitochondria and as a cluster in the cytoplasm. Cells divided symmetrically and at the end of the heat treatment, acquired the features of induced bicellular structures described previously. The features persisted as the cells divided randomly within the exine for 4–7 days following heat induction. Multicellular structures released from the exine underwent periclinal divisions resulting in protoderm differentiation of the globular embryo, thus determining embryo development. The cytoplasm of early heart-stage embryos contains abundant polyribosomes. Non-embryogenic development was indicated by large accumulations of starch and/or lipid and thickened cell walls or an unorganized pattern of cell division following release of the multicellular structures from the exine. Embryogenesis is discussed in terms of induction, embryo determination and development.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01272758
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  • 74
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    Disturbance of the secretory pathway inMicrasterias denticulata by tunicamycin and cyclopiazonic acid (1995)
    Springer
    Protoplasma 189 (1995), S. 173-179 
    Details
    ISSN: 1615-6102
    Keywords: Cyclopiazonic acid ; Golgi apparatus ; Micrasterias ; Secretory pathway ; Tunicamycin ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Both tunicamycin, an inhibitor of N-linked glycosylation of proteins, and cyclopiazonic acid, which inhibits the Ca2+-dependent ATPase in the ER, influence the secretory pathway at the ER level and lead to a cessation of cell growth inMicrasterias. Electron microscopical investigations reveal that the mode of action of the two inhibitors differs. While tunicamycin treatment results in a disintegration of the Golgi bodies into small vesicles, cyclopiazonic acid prevents products being supplied from the ER, resulting in the dilatation of ER cisternae and a reduction in the number of Golgi cisternae, combined with a loss of dictyosomal activity. The disturbed cell wall formation under tunicamycin indicates that N-linked glycosylation of proteins is required for normal cell growth inMicrasterias. Moreover, our studies reveal that changes in cytoplasmic free calcium concentration, as a consequence of ATPase inhibition in the ER by cyclopiazonic acid, may inhibit wall material secretion by interrupting the normal ER-dictyosome association.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01280171
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  • 75
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    Studies on turfgrass snow mold caused byTyphula ishikariensis. II. Microscopical observation of infected bentgrass leaves (1995)
    Springer
    Mycoscience 36 (1995), S. 179-185 
    Details
    ISSN: 1618-2545
    Keywords: Turfgrass snow mold ; Typhula ishikariensis ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Light and transmission electron microscopy revealed thatTyphula ishikariensis penetrated into bentgrass leaves either through cuticles or stomata either by single hyphae or infection cushions formed on host surfaces. Time course study on infected leaves showed that penetration through stomatal subsidiary cells and their adjacent cells seemed to occur earlier than that through epidermal cells located farther from stomata. More than 30% of epidermal cells were infected by 10 days after inoculation. When hyphae penetrated through an intact cuticle of epidermal cells, they seemed to dissolve host cell walls enzymatically at penetration sites. Physical pressure also seemed to be involved in penetration.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02268555
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  • 76
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    Plasticity of gonad development in hermaphroditic sparids: ovotestis ontogeny in a protandric species, Lithognathus mormyrus (1995)
    Springer
    Environmental biology of fishes 43 (1995), S. 255-267 
    Details
    ISSN: 1573-5133
    Keywords: Gonadogenesis ; Early germ cell ; Teleost ; Ultrastructure ; Fish
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Synopsis Heterosexual gonad development in a sparid species, Lithognathus mormyrus, was studied by histological and cytological examination, during the first three years of life. Gonad bisexuality is achieved after two months of development, according to the cytological dynamics known in sparids. In one-year-old fishes, a variability in the gonad morphology of the juvenile is shown: three different types of ovotestis have been identified within the same cohort: ovotestes with testicular prevalence (25%), testicular and ovarian equivalence (20%), and ovarian prevalence (55%). This morphological variability of the juvenille ovotestes was consistent with the histological analysis of the sexual structure of the adult stock at the first sexual maturity, which constituted 55.5% of functional males (stemming from the first types of ovotestis) and 44.5% of primary females (from the third type). The plasticity of sexual expression in sparids is emphasized, revealing the potentialities of the ovotestis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00005857
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    Industrial mycology and the new genetics (1995)
    Springer
    Journal of industrial microbiology and biotechnology 14 (1995), S. 355-364 
    Details
    ISSN: 1476-5535
    Keywords: Transformation ; Fungi ; Yeast ; Genetics ; Biotechnology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Summary The genetic investigation of fungi has been extended substantially by DNA-mediated transformation, providing a supplement to more conventional genetic approaches based upon sexual and parasexual processes. Initial transformation studies with the yeastSaccharomyces cerevisiae provided the model for transformation systems in other fungi with regard to methodology, vector construction and selection strategies. There are, however, certain differences betweenS. cerevisiae and filamentous fungi with regard to type of genomic insertion and the availability of shuttle vectors. Single-site linked insertions are common in yeast due to the high level of homology required for recombination between vectored and genomic sequences, whereas mycelial fungi often show a high frequency of heterologous and unlinked insertions, often in the form of random and multiple-site integrations. While extrachromosomally-maintained or replicative vectors are readily available for use with yeasts, such vectors have been difficult to construct for use with filamentous fungi. The development of vectors for replicative transformation with these fungi awaits further study. It is proposed that replicative vectors may be inherently less efficient for use with mycelial fungi relative to yeasts, since the mycelium, as an extended and semicontinuous network of cells, may delimit an adequate diffusion of the vector carrying the selectable gene, thus leading to a high frequency of abortive or unstable transformants.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01569951
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    Inverted ductal papilloma of minor salivary gland origin: morphological aspects and cytokeratin expression (1995)
    Springer
    European archives of oto-rhino-laryngology and head & neck 252 (1995), S. 370-373 
    Details
    ISSN: 1434-4726
    Keywords: Salivary gland tumors ; Inverted ductal papilloma ; Ultrastructure ; Cytokeratin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Ultrastructural features and cytokeratin expression of inverted ductal papillomas of minor salivary gland origin were studied. Under the electron microscope, an increased number of desmosomes and mucus-like granules in some cells were the most striking features. Immuno-histochemical study revealed that tumor cells displayed strongly positive reactions with cytokeratins 13 and 14, and less strong reactions with cytokeratins 7, 8, 18 and 5D3. These results support the hypothesis that an inverted ductal papilloma can be derived from the proximal portion of a salivary gland excretory duct.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00178280
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    Determination of viability of cryopreserved cartilage grafts (1995)
    Springer
    European archives of oto-rhino-laryngology and head & neck 252 (1995), S. 30-34 
    Details
    ISSN: 1434-4726
    Keywords: Cartilage grafting ; Cryopreservation ; Cell biology ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Although transplantation of preserved cartilage has assumed a role of great importance in reconstructive surgery, there are many divergent and contradictory opinions with regard to the outcome of cryopreserved cartilage. This study was formulated to assess the functional state of chondrocytes after cryopreservation. Freeze injury and survival were studied using the trypan blue dye exclusion test, functional assay for cell adhesion and transmission electron microscopy. The methods applied clearly proved that a greater part of the cartilage cells was irreversibly damaged by cryopreservation. Findings demonstrated that cryopreserved cartilage remained non-viable and was not ablt to originate new cartilage. Thus, such cartilage will be reconstruction of parts of the skeleton subject to mechanical stress. The feasibility of cryopreservation techniques for providing vital cartilage substitutes needs further evaluation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00171437
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    The importance of chemical data for the study of interstellar shocks (1995)
    Springer
    Astrophysics and space science 233 (1995), S. 125-137 
    Details
    ISSN: 1572-946X
    Keywords: Interstellar Medium ; Dark Clouds ; Chemistry ; Bistability ; C-shock Waves
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract Shock waves perturb the chemical state of the interstellar gas. We consider the effects of C-shocks on the composition of molecular clouds, for a range of values of the pre-shock gas density and magnetic induction. The time required to re-establish equilibrium in the post-shock gas depends on the initial conditions and can become very large. The significance of the two known chemical phases of dark clouds and of bistability is considered in this context.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00627340
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    Molecular diagnostics of diffusive boundary layers (1995)
    Springer
    Astrophysics and space science 233 (1995), S. 161-164 
    Details
    ISSN: 1572-946X
    Keywords: Stars ; Chemistry ; Diffusion
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract We have assessed the role of diffusion in determining chemical abundances in molecular interface regions. Chemical models have been developed which include the appropriate diffusion terms and that are appropriate to a narrow diffusion region (∼0.01pc) that may exist at the interface between a dark core and a hot, shocked T-Tauri wind. We have assumed pressure balance throughout and have calculated the chemical abundances as functions of time and position through the interface. The results show that significant enhancements of detectable molecules/transitions are expected (e.g. CO J=6→5, OH and CH). Using a realistic value of the diffusion coefficient a diffusive region of dimension 0.01pc may be established within about 104 years. In general it seems likely that diffusion processes are highly significant on these and smaller lengthscales.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00627344
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    Have fishes had their chips? The dilemma of threatened fishes (1995)
    Springer
    Environmental biology of fishes 43 (1995), S. 1-27 
    Details
    ISSN: 1573-5133
    Keywords: Conservation ; Extinction ; Rarity ; Biodiversity ; Breeding guilds ; Endemism ; Speciation ; Habitat degradation ; Environmental management ; Invasive fishes ; Genetics ; Ecology ; Stenotopy ; Captive propagation ; Legislation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Synopsis The conservation status and factors threatening fishes worldwide are reviewed in order to introduce a series of one-page articles on ‘Threatened fishes of the world’, and to encourage the incorporation of information on threatened fishes into international conservation programmes. Information on fish extinction and threat rates are compared with those of other animal groups, and the unique characteristics of fish conservation problems are highlighted. At present 979 species of fishes are listed as threatened in the IUCN Red List and at least 36 species and three subspecies are listed as recently extinct. It is argued that these figures are probably gross underestimates and that they may mislead conservation authorities and resource users about the seriousness of the situation. Freshwater fishes may be the most threatened group of vertebrates after the Amphibia. Urgent action is required to save many narrowly endemic, stenotopic species from extinction, especially in Africa, Asia and South America. The conservation of common species that drive essential ecological processes is also important. Anthropogenic pressures, especially habitat degradation, the introduction of invasive species and pollution, on inland and coastal waters are particularly severe and many major fish communities are threatened with elimination throughout the world. The conservation of marine fishes is complicated by the fact that it is difficult to ascertain their rarity. The importance of the retention of genetic variation is highlighted, and both orthodox and innovative conservation measures are encouraged. Further research on minimum viable populations, genetics, and the factors that cause fishes to become vulnerable to extinction, is urgently required.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00001812
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    Optimization of mechanical strength of reinforced composites. 1. Study on the effect of reactive bismaleimide on the mechanical performance of CaCo3-filled polypropylene (1995)
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 224 (1995), S. 9-20 
    Details
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Der Einfluß von 3-Phenylenbismaleimid auf die Werkstoffeigenschaften von CaCO3 gefüllten Polypropylen-Verbundstoffen wurde untersucht. Die Verarbeitungstemperatur spielte eine entscheidende Rolle bei der Herstellung der Verbundwerkstoffe. Bei Verarbeitungstemperaturen oberhalb der Bismaleimid-Zersetzungstemperatur zeigte die Bismaleimid-Verbindung einen positiven Effekt. Die chemische Zusammensetzung der modifizierten Verbunde wurde mit den mechanischen Eigenschaften korreliert. Basierend auf ESCA-Analysen werden Wechselwirkungen zwischen dem Polymeren und CaCO, diskutiert.
    Notes: The effect of 3-phenylene bismaleimide on the mechanical performance of an inorganic filler-based polypropylene composite was studied. The selection of processing temperature played a significant role in the preparation of such composites. A positive effect of the bismaleimide compound was obtained for a processing temperature above the decomposition temperature of bismaleimide. The chemical composition of the modified composite was correlated to its mechanical strength by experimentation involving a rotatable design. An interaction between polymer and CaCO3 has been proposed based on ESCA analysis.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/apmc.1995.052240102
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    The effect of the processing steps on the oxidative stability of polyethylene tubing crosslinked by irradiation (1995)
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 224 (1995), S. 33-48 
    Details
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Chemische und mechanische Eigenschaften von Zwischenprodukten der PE-Schrumpfschlauch-Produktion wurden bei unterschiedlichen Compound-Zusammensetzungen (PE, ein aromatisches Amin oder Phenolderivat als Antioxidans und in einigen Fällen ein Flammschutzmittel und/oder eine Elastomerkomponente) untersucht.Während der Herstellung, besonders während der durch Elektronenstrahlung initiierten Vernetzung, nimmt die thermooxidative Stabilität des Materials gegenüber der des compoundierten Granulats ab. Das aromatische Amin scheint bei gleicher Zusammensetzung das wirksamere und strahlungsbeständigere Antioxidans im Vergleich zum Phenolderivat zu sein. Die Oxidationsstabilität der hergestellten Schrumpfschläuche wird nicht von der Qualität des eingesetzten PE-Ausgangsgranulats beeinflußt.Durch die Alterung des Materials ändern sich die mechanischen Eigenschaften geringfügig. Die Elastomerzugabe bewirkt keine Änderung von Zugfestigkeit und Reißdehnung. Die Stabilität des Endprodukts ist bei weitem ausreichend, um den Spannungen, die beim Schrumpfen während des Gebrauchs auftreten, standzuhalten. Die gute Zugfestigkeit des Materials wird durch die Alterung ebenfalls nicht beeinträchtigt.Bei der Extrusion des Granulats tritt keine nennenswerte Änderung des Molekulargewichts bzw. der Molekulargewichtsverteilung auf. Durch die Bestrahlung wird das Material vernetzt und zu mehr als 50% unlöslich, und seine thermooxidativen Eigenschaften ändern sich deutlich gegenüber dem ursprünglichen PE und dem daraus compoundierten Material.
    Notes: Some chemical and mechanical properties of intermediate products obtained in the production of PE heat-shrinkable tubes were studied at different compositions of the material containing PE, antioxidant (aromatic amime or phenol) and, in some cases, flame retardant and/or an elastomer.In the course of the production phase, the thermooxidative stability decreases compared to that of compounded granulate. The greatest decrease is caused by irradiation. The aromatic amine seems to be a more effective antioxidant at similar compositions than the phenol derivative, and it shows a better resistance against irradiation. The oxidative stability of the finished shrinkable tubes is not affected by the quality of commercial granulate (initial polyethylene).Mechanical properties change slightly upon ageing, and the introduction of the elastomer did not alter the tensile strength and elongation at break. The remaining stability of the end product was still high enough to bear the stress of shrinking in use, and the good tensile strength of the material did not decrease upon thermal ageing either.In the extrusion of the granulated compound no significant change in the distribution and average molecular weight took place. Irradiation produced more than 50% insoluble fraction and the thermooxidative properties of the crosslinked sample changed significantly compared to the original PE and to the compound prepared from it.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/apmc.1995.052240104
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  • 85
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    Thermogravimetrie als brennbarkeitsbestimmungs-methode für lineare polyurethane (1995)
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 224 (1995), S. 89-96 
    Details
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: In the present work oxygen index (OI) measurements and thermogravimetric analysis (TG) for a series of polyurethanes based on diols and isocyanate were conducted. It was found that a correlation exists between some of the thermal degradation parameters obtained from TG and OI-values. Analysis of experimental results confirms that the amount of mass loss at 250°C is directly proportional to the OI-value. It was also found that the logarithmic temperatures of maximal decomposition rates are directly proportional to the OI-values.
    Notes: In der vorliegenden Arbeit wurden für eine Serie von Polyurethanen auf der Basis von Diol und Isocyanat der Sauerstoffindex (SI) gemessen und die thermische Zersetzung mittels thermogravimetrischer Analyse (TG) untersucht. Dabei wurde ein Zusammenhang zwischen einigen Parametern der thermischen Zersetzung und den SI-Werten gefunden. Die Auswertung der experimentellen Ergebnisse zeigte, daß die Höhe des Massenverlustes bei 250°C und die SI-Werte direkt proportional zueinander sind. Derselbe Zusammenhang besteht auch zwischen dem Logarithmus der Temperatur bei der maximalen Zersetzungsgeschwindigkeit und den SI-Werten.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/apmc.1995.052240109
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    Studies on thermal stability of modified polycarboxylate cements (1995)
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 224 (1995), S. 109-114 
    Details
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Poly(acrylsäre-co-acrylamid) wurde mit Zinkoxid und Kryolith (Na3AlF6) in unterschiedlichen Verhältnissen gemischt und bei Raumtemperatur zu Zahnzementen ausgehärtet. IPDT, Temperaturen bei maximaler Abbaugeschwindigkeit, Aktivierungsenergien und Frequenzfaktoren des thermischen Abbaus der Proben wurden aus thermogravimetrischen Messungen ermittelt. Die Probe mit 20 Gew.-% Kryolith in der Füllstoffmischung ist thermisch sehr stabil.
    Notes: Dental cement compositions made by mixing poly(acrylic acid-co-acrylamide) and mixtures of zinc oxide and cryolite (Na3AIF6) in various proportions of 10-50 wt.-% (w/w) were cured at room temperature. From thermogravimetric analyses of the samples, the integral procedural decomposition temperatures (IPDT), maximum decomposition temperatures, activation energies and frequency factors were evaluated. The cured cement sample containing 20 wt.-% cryolite in the filler mixture is thermally very stable.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/apmc.1995.052240111
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    Synthesis and characterization of water-soluble diazonium salts as contrast-enhancement materials (1995)
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 224 (1995), S. 133-144 
    Details
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Die wasserlöslichen aromatischen Diazonium-Doppelsalze p-Diazodiphenylaminchlorid/Zinkchlorid (DZS-1) und p-Diazoanisolchlorid/Zinkchlorid (DZS-2) wurden auf ihre Verwendbarkeit als photobleichbare Farbstoffe in der Kontrastverstärkungslithographie untersucht. Nach Untersuchung der Bleicheigenschaften der hergestellten Salze wurde DZS-1 in wäßrigen Lösungen mit Poly(vinylalkohol) als Kontrastverstärkungssystem eingesetzt. Die thermische Stabilität, der Resistkontrast, die Bestrahlungsparameter und andere Bleicheigenschaften wurden untersucht. Im Vergleich zu einem handelsüblichen i-Linien-Photoresist beträgt das Kontrastverhältnis der DZS-1/PVA CEL-Schicht 1,67.
    Notes: Water soluble aromatic diazonium double salts, p-diazodiphenylamine chloride zinc chloride (DZS-1) and p-diazoanisol chloride zinc chloride (DZS-2), have been evaluated as photobleachable dyes for contrast enhancement lithography. After testing the bleaching characteristics, aqueous solutions of DZS-1 and poly(vinyl alcohol) were used as a contrast enhancement material. Thermal stability, resist contrast, exposure parameters and other bleaching characteristics of the photobleachable membranes were investigated. A. commercial i-line photoresist was used to evaluate the contrast ratio of the DZS-1/PVA CEL layer. The contrast ratio obtained in this investigation is 1.67.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/apmc.1995.052240114
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    Comparison of the coupling behaviour of diisocyanate and bisoxazolines in modification of liquid crystalline poly(ethylene terephthalate-co-oxybenzoate)s (1995)
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 224 (1995), S. 167-178 
    Details
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Methylen-4,4′-diphenyldiisocyanat und zwei unterschiedliche Bisoxazoline wurden für Kopplungsreaktionen in mit Carboxygruppen terminierten flüssigkristallinen Poly(ethylenterephthalat-co-oxybenzoat)en eingesetzt. Um definierte Bedingungen zu gewährleisten, erfolgte die Synthese von Copolyestern mit unterschiedlichen Carboxygruppenkonzentrationen. Die Bestimmung des Carboxygruppengehalts wird beschrieben.Es erfolgt ein Vergleich des Kopplungsverhaltens beider Arten von Kettenverlängerern. Es konnte nachgewiesen werde, daß die Bisoxazoline bedeutend schneller reagieren als das Diisocyanat. Durch einen geringen Überschuß and Bisoxazolin in der Reaktionsmischung konnte einer thermischen Schädigung vorgebeugt werden. Abhängig von der Menge an zugegebenem Koppler wurden bei den modifizierten Copolyestern Oxazolinendgruppen beobachtet. Außerdem werden mögliche Vernetzungsreaktionen und die thermische Stabilität diskutiert.
    Notes: Methylene-4,4′-diphenyldiisocyanate and two different bisoxazolines were used for coupling reactions in carboxy-terminated liquid crystalline poly(ethylene terephthalate-co-oxybenzoate). In order to guarantee defined conditions, copolyesters with different carboxylic group concentrations were synthesized. The determination of the carboxylic group content is described.The coupling behaviour of both types of chain extenders has been compared. It was evidenced that the bisoxazolines reacted significantly faster than the diisocyanate. A slight excess of bisoxazoline in the reaction mixture prevented thermomechanical degradation. Depending on the amount of coupling agent added, an oxazoline termination of the copolyester was observed. Additionally, probable crosslinking reactions and the thermal stability have been discussed.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/apmc.1995.052240117
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  • 89
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    Announcements (1995)
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 224 (1995), S. 201-201 
    Details
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/apmc.1995.052240120
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  • 90
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    Optimization of mechanical strength of reinforced composites. 2. Reactive bismaleimide-modified polypropylene composites filled with talc and zeolitePart 1 cf.2. (1995)
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 225 (1995), S. 11-20 
    Details
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Der Einfluß von 3-Phenylenbismaleimid auf die Werkstoffeigenschaften von mit Talkum und Zeolith gefüllten Polypropylen-Verbundstoffen wurde untersucht. Durch geeignete Planung des Aufbaus kann die Produkteigenschaft optimiert werden. Die Kapazität zur Füllstoffaufnahme schwankt bei Polypropylen je nach Art des Füllstoffs. Ein hochbelastbarer Verbundstoff kann aus einem geeignet modifizierten, mit Zeolith gefüllten Polypropylen hergestellt werden, auch wenn der Füllstoff in der Verbundmatrix dominiert. Als Ursache dieser Verstärkung wird eine verbesserte Wechselwirkung zwischen dem Polymeren und dem Füllstoff angenommen.
    Notes: The effect of 3-phenylene bismaleimide as a modifier for talc and zeolite-filled polypropylene composites has been studied. The usefulness of the experimental design to assure best product properties has also been illustrated. Polypropylene shows a variable degree of filling capacity depending on the type of filler. A high-strength composite can be prepared with suitably modified zeolite-filled polypropylene even if filler is the dominant phase in the composite matrix. An improved interfacial interaction between polypropylene and filler is proposed to be the reason for this improvement of strength.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/apmc.1995.052250102
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  • 91
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    Oligomerization of 1-decene with Ziegler-Natta catalysts (1995)
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 225 (1995), S. 51-61 
    Details
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Die katalytische Oligomerisation von 1-Decen wurde mit Komplexverbindungen mehrerer Übergangsmetalle (Co(II), Co(III), Zr(IV), Ti(IV), Cr(III), V(V)) und Alkyl-aluminiumhalogeniden als Cokatalysatoren durchgeführt. Mit einem Chrom(III)-Et3Al2Cl3-Katalysatorsystem konnten Dimere (C20), Trimere (C30) und Tetramere (C40) von 1-Decen erhalten werden. Die kinematischen Viskositäten und Fließpunkte der hydrierten Oligomere wurden bestimmt und mit den Werten handelsüblicher Proben verglichen. Ein Mechanismus für die Oligomerisation von 1-Decen mit diesem Katalysatorsystem wird vorgeschlagen.
    Notes: The catalytic oligomerization of 1-decene has been carried out employing several transition metal complexes of Co(II), Co(III), Zr(IV), Ti(IV), Cr(III), V(V) in combination with alkyl aluminum halides as cocatalysts. The chromium(III)-Et3Al2Cl3 system exhibits good oligomerizing activity yielding dimers (C20), trimers (C30) and tetramers (C40) of 1-decene. The kinematic viscosities and pour points of hydrogenated oligomers have been determined and compared with those of commercial samples. The probable mechanism of oligomerization of 1-decene on this catalyst is described.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/apmc.1995.052250105
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  • 92
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    Zur Häurtung von Bisphenol-A-diglycidether mit Dicyandiamid in Gegenwart von Beschleuniger-Addukten (1995)
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 225 (1995), S. 99-107 
    Details
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Single-component formulations of epoxy resins with reactive accelerators must be storable. The preparation of several blocked accelerators is described. The basicity of tertiary amines, which correlates with accelerating effects, as well as acidity and structure of polyphenols and modified novolacs influences the extend of blocking. The curing process was investigated by measurements of gel time and viscosity.
    Notes: Einkomponentige Epoxidharzsysteme mit effizienten Reaktionsbeschleunigern müssen lagerstabil sein. Daher wurden Versuche unternommen, Beschleuniger auf Basis von tertiären Aminen mit modifizierten Phenolnovolaken zu blockieren. Das Ausmaß der Blockierung ist sowohl von der Basizität der Amine, die mit der beschleunigenden Wirkung korreliert, als auch von der Acidität und dem strukturellen Aufbau der modifizierten Phenole abhängig. Die Bewertung der Härtungseigenschaften erfolgte über Gelzeitbestimmungen und Viskositätsmessungen.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/apmc.1995.052250109
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  • 93
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    Comparison of the crack growth method and the crack stress whitening zone method for the fracture toughness determination of phenolphthalein poly(ether ketone)Key Project of the National Natural Science Foundation of China. (1995)
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 225 (1995), S. 131-138 
    Details
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Die Bruchzähigkeit von Phenolphthalein-Poly(etherketon) bei 190°C wurde mit zwei verschiedenen Methoden bestimmt, der konventionellen Rißwachstumsmethode und der „stress whitening zone“-Methode. Die gute Übereinstimmung der Ergebnisse zeigt, daß letztere Methode zur Bestimmung der Rißinitiierung einiger Polymerer herangezogen werden kann, für die das „blunting line concept“ nicht geeeignet ist.
    Notes: Fracture toughness values of phenolphthalein poly(ether ketone) (PEK-C) at 190°C were determined by two different methods, i.e. the conventional crack growth method and the crack stress whitening zone method, which show consistent results. This indicates that the crack stress whitening zone method can be used to determine the crack initiation of some polymers for which the blunting line concept is unsuitable.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/apmc.1995.052250112
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  • 94
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    Thermodynamic studies on some interpolymer interactions and stability of polycomplexes (1995)
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 226 (1995), S. 13-22 
    Details
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Stabilitätskonstanten und zugehörige thermodynamische Parameter (ΔH°, ΔS°) eines intermakromolekularen Komplexes aus Poly(acrylsäure-co-acrylamid), Poly(methacrylsäure-co-acrylamide) und Poly(N-vinylpyrrolidon) wurden mit bekannten Methoden bei verschiedenen Temperaturen bestimmt. Dabei wurde eine stufenweise Auflösung des Komplexes in Abhängigkeit von der Temperatur beobachtet, die mit den Stabilitätskonstanten und den thermodynamischen Parametern korreliert wurde.
    Notes: Stability constant and related thermodynamic parameters (ΔH° and ΔS°) of a multicomponent intermacromolecular complex consisting of poly(acrylic acid-coacrylamide), poly(methacrylic acid-co-acrylamide) and poly(N-vinylpyrrolidone) have been determined using known methods. A distinct stepwise disintegration of the complex at different temperatures has been observed, and this could be correlated with the stability constant and thermodynamic parameters calculated at various temperatures.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/apmc.1995.052260102
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  • 95
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    The effect of ultrasound in ethyl methacrylate polymerization and depolymerization reactions (1995)
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 226 (1995), S. 53-57 
    Details
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Der Einfluß von Ultraschall auf die Polymerisation und Depolymerisation von Ethylmethacrylat und der Mechanismus des Kettenabbruchs wurden untersucht. Der Polymerisationsumsatz war unabhängig von den verwendeten Ultraschallbedingungen (800 W, 35 kHz). Depolymerisationsversuche mit Ultraschall bei 20°C zeigten, daß Kettenabbruch im wesentlichen durch Disproportionierung stattfindet; dabei werden Molekulargewichte nicht unter ca. 500000 erreicht.
    Notes: The effect of ultrasound in ethyl methacrylate polymerization and depolymerization and the chain termination mechanism for ethyl methacrylate have been studied. Polymerization conversion at 60°C did not depend on energy (80 W) and frequency (35 kHz) of ultrasound applied. In ultrasound depolymerization studies at 20°C the governing termination mechanism was found to be disproportionation and the lower limiting molecular weight was Mn = 500 000.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/apmc.1995.052260106
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  • 96
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    Reaktive membrancopolymere auf acrylbasis (1995)
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 226 (1995), S. 71-87 
    Details
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: The copolymerization of acrylonitrile with maleic anhydride was investigated to synthesize acylic reactive polymers for manufacture of membranes that serve as support for covalent enzyme immobilization. The free-radical copolymer synthesis was carried out in solution (N,N-dimethylformamide (DMF), dimethylacetamide (DMAC), γ-butyrolactone, ethylene carbonate), by precipitation polymerization (dioxane) as well as bulk polymerization. The polymers were characterized using IR spectroscopy, elementary analysis, NMR spectroscopy, gel permeation chromatography, viscosity measurements, osmometry and potentiometry.The kinetic parameters were followed by dilatometric measurements up to high conversions. The anhydride content in the monomer mixtures showed a significant influence on the rate of polymerization and the molecular weight. With raised concentration of anhydride the polymerization rate and molecular weights decreased. Film forming polymers (M̄η 〉 30 000 g/mol) can be obtained by all copolymerization procedures with exception of solution polymerization in DMF and DMAC, respectively. The content of maleic anhydride in the membrane polymers did not exceed 5 mol-%, even though the maleic anhydride content in the monomer mixtures was raised up to the equimolar mixture. Nevertheless, such low maleic anhydride content of prepared membranes is enough for successful enzyme immobilization with amyloglucosidase (copolymer was prepared in γ-butyrolactone, M̄η = 49 000 g/mol, cPMSA = 0,3 mol-%).
    Notes: Die Copolymerisation des Acrylnitrils mit Maleinsäureanhydrid (MSA) wurde mit dem Ziel untersucht, acylfunktionalisierte Reaktivpolymere mit Filmbildungseigenschaften herzustellen, um diese in der Anwendung als Membran für kovalente Enzymfixierungen zu nutzen. Die radikalinitiierte Synthese der Copolymeren wurde in Lösung (Dimethylformamid (DMF), Dimethylacetamid (DMAC), γ-Butyrolacton, Ethylencarbonat), durch Fällungscopolymerisation (Dioxan) sowie in Substanz durchgeführt.Die Polymercharakterisierung erfolgte durch IR-Spektroskopie, Elementaranalyse, Kernresonanzspektroskopie, Gelpermeationschromatographie, Viskosimetrie, Osmometrie und Potentiometrie.Die Kinetik wurde durch dilatometrische Untersuchungen bis zu hohen Umsätzen verfolgt. Danach weist der Anhydridgehalt im Monomergemisch einen signifikanten Einfluß auf die Bruttopolymerisationsgeschwindigkeit und die Molmasse der Polymeren auf. Mit steigendem Anhydridanteil wird die Bruttopolymerisationsgeschwindigkeit herabgesetzt und eine Verringerung der Molmasse herbeigeführt. Die Copolymerisation von Acrylnitril und Maleinsäureanhydrid führt mit Ausnahme der Lösungspolymerisation in DMF bzw. DMAC zu Polymeren mit Molmassen oberhalb 30 000 g/mol, was ihre Anwendung als Membran ermöglicht. Die Einbaurate an Maleinsäureanhydrid in den Membranpolymeren ist bis einschließlich einer äquimolaren Zusammensetzung des Monomergemischs nicht größer als 5 mol-%. Derartig niedrige MSA-Reaktivgruppenanteile erweisen sich jedoch als ausreichend, um an einer aus einem Lösungspolymerisat (γ-Butyrolacton, M̄η = 49 000 g/mol, cPMSA = 0,3 mol-%) formierten Membran eine Enzymimmobilisierung mit Amyloglucosidase nachzuweisen.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/apmc.1995.052260108
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  • 97
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    Synthesis and characterization of photopolymers with azo units. Interfacial polyaddition, photolysis, photodegradation (1995)
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 226 (1995), S. 143-160 
    Details
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Die Synthesen einer Aryl-alkyl-azodiisocyanat-Verbindung und einer Azoharnstoff-Modellsubstanz werden beschrieben. Aus dem Azodiisocyanat wurden durch Grenzflächen-Polyaddition neuartige Azoharnstoff-Polymer hergestellt. Die zahlenmittleren Molekulargewichte, bestimmt mit der Gelpermeationschromatographie (GPC), lagen zwischen 6000 und 9000. Die Photolyse- und Thermolysereaktionen der Modellsubstanzen und der Polymeren wurden mittels UV-Spektroskopie und Differentialkalorimetrie (DSC) verfolgt und mit den Ergebnissen von ähnlichen Azoamiden verglichen. Der photochemische Polymerabbau wurde mittels GPC untersucht.
    Notes: The synthesis of an aryl alkyl azo diisocyanate and a model azo urea is described. From the azo diisocyanate new azo polyureas were created by interfacial polyaddition. Molecular weights Mn in the range of 6000 to 9000 were determined by gel permeation chromatography (GPC). Photolysis and thermolysis of both, model compounds and polymers, were studied by UV-spectroscopy and differential scanning calorimetry (DSC), respectively, and the results were compared with those of similar azo amides. Photochemical polymer degradation was followed by GPC.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/apmc.1995.052260113
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  • 98
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    Announcements (1995)
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 226 (1995), S. 219-219 
    Details
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/apmc.1995.052260120
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  • 99
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    Molecular structure of liquid-crystalline copolyesters of vanillic acid, 4-hydroxybenzoic acid and poly(ethylene terephthalate) (1995)
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 227 (1995), S. 69-85 
    Details
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Thermotrop flüssigkristalline Copolyester aus Vanillinsäure (V), 4-Hydroxybenzoesäure (B) und Polyethylenterephthalat (E) wurden mittels 1H-NMR-Spektroskopie und Gelpermeationschromatographie (GPC) untersucht. Die neun möglichen Diaden konnten detektiert und zugeordnet werden. Die Abfolge der Grundeinheiten der V/B/E-Copolyester ändert sich mit zunehmendem B-Anteil von statistischer Verteilung zur Blockbildung und ist außerdem geringfügig von der Katalysatorkonzentration und der Polykondensationsdauer abhängig. Die GPC-Ergebnisse deuten darauf hin, daß die V/B/E-Copolyester engere Molekulargewichtsverteilungen aufweisen als die B/E-Copolyester. Mit von 0 bis 5 mol-% steigendem V-Anteil verengt sich die Molekulargewichtsverteilung. Die Gelpermeationschromatogramme der meisten V/B/E-Copolyester weisen im Unterschied zu den Einzelsignalen der B/E-Copolyester Dublett-Peaks auf.
    Notes: Thermotropic liquid-crystalline copolyesters made from vanillic acid (V), 4-hydroxybenzoic acid (B) and poly(ethylene terephthalate) (E) were examined by 1H-NMR and GPC investigations. Nine possible diads could be identified and assigned. The sequence distribution of V/B/E copolyesters tends to change from random to block with an increase of B content in the copolyesters. The sequence distribution also varies slightly with catalyst concentration and polycondensation time. GPC results suggest that the V/B/E copolyesters have narrower molecular weight distribution (MWD) than B/E copolyesters. The MWD of the copolyesters narrows gradually with increasing V content from zero to 5 mol-%. The GPC chromatograms of the most V/B/E copolyesters show double peaks, which is different from the single peak of the GPC chromatograms of the B/E copolyesters.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/apmc.1995.052270108
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  • 100
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    Effect of pre-irradiation on radiation stability of co-polypropylene (1995)
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 227 (1995), S. 111-120 
    Details
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Die Strahlungsbeständigkeit von vorbestrahltem Polypropylen mit 2,5 Gew.-% Ethylenanteil wurde mitr einem Copolymeren aus Polypropylen und einem nukleierenden Agens im Hinblick auf die Strahlungssterilisation von medizinischen Geräten verglichen. Die Transparenz des Propylen-Ethylen-Copolymeren wurde durch die Vorbehandlung verbessert. Im Vergleich mit der ebenfalls verbesserten Transparenz des Copolymeren aus Polypropylen und dem nukleierenden Agens wurde durch die Vorbestrahlung die Strahlungsbeständigkeit während der Bestrahlung und bei der Lagerung des bestrahlten Materials verbessert. Dies wird auf die geringere Kristallinität des vorbestrahlten Polypropylens aufgrund von bei der Bestrahlung gebildeten Verzweigungen zurückgeführt.
    Notes: The radiation stability of the pre-irradiated copolymer of polypropylene containing 2.5 wt.-% ethylene units is compared with a copolymer of polypropylene with a nucleating agent with regard to radiation sterilization of medical devices. It is found that transparency property of the propylene-ethylene copolymer is improved through pre-irradiation processes. This finding was compared with the co-polypropylene with nucleating agent which also gives a better transparency property. In comparison, it is found that pre-irradiated copolymer exhibits better radiation stability during irradiation and during storage after irradiation. The radiation stability of the pre-irradiated copolymer is due to its lower crystallinity caused by the formation of branches during the pre-irradiation process.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/apmc.1995.052270111
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