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  • 1995-1999  (38)
  • 1980-1984  (1,156)
  • 1998  (38)
  • 1980  (1,156)
  • Inorganic Chemistry  (757)
  • Atomic, Molecular and Optical Physics  (277)
  • Ultrastructure
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  • 1995-1999  (38)
  • 1980-1984  (1,156)
Year
  • 1
    ISSN: 1432-2307
    Keywords: Key words Apoptosis ; Crescent-shaped spaces ; Ultrastructure ; Nivalenol ; Thymus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract  There have been many reports on the formation of apoptotic bodies, but little is known about the cellular pathological processes and the morphological changes involved. We induced apoptotic cell death by administering nivalenol (NIV), a trichothecene mycotoxin produced by Fusarium species, and investigated the ultrastructural process of formation of apoptotic bodies. The thymus was examined by electron microscopy 6, 12, and 18 h after administration. Apoptotic cell death was induced in the thymus of NIV-treated mice. The nuclei became invaginated and pinched off to give fragments, and crescent-shaped spaces (CSS) were found around the nuclear envelopes of these cells at quite an early stage. In some of these spaces, myelin figures were observed. We divided the process of formation into four stages and characterized each of them. These are easily recognized in morphological stages and are also useful for clarifying the apoptotic mechanism.
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  • 2
    ISSN: 1432-0533
    Keywords: Key words Brittany Spaniel dog ; Immunocytochemistry ; Purkinje cell ; Spinocerebellar degeneration ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Eight Brittany Spaniel dogs, seven females and one male, between 7 and 14 years old presented with clinical neurological signs of spinocerebellar disease of about 6 months to 4 years duration. Clinically the dogs had a dramatic forward “saluting” movement of the thoracic limbs, hypermetria of the pelvic limbs, cerebellar ataxia and intention tremors. Terminally, dogs crawled in a crouched thoracic posture with neck extension. Lesions were confined to cerebellum, medulla oblongata and spinal cord. The most severe lesion was diffuse Purkinje cell loss with massive neurofilament accumulation in degenerating cells. There was some bilateral neuronal degeneration in the dorsal horns of the spinal cord and in the gracilis and cuneate nuclei. There was bilateral sporadic axonal degeneration in the dorsal columns and lateral and ventromedial areas of the spinal cord. The etiology of this syndrome was not determined.
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Acta neuropathologica 95 (1998), S. 367-372 
    ISSN: 1432-0533
    Keywords: Key words Amyotrophic lateral sclerosis ; Heterotopic neuron ; Alpha motor neuron ; Immunocytochemistry ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract This report concerns a comparative immunocytochemical, ultrastructural and morphometric investigation on heterotopic neurons in the white matter of the spinal cords of 19 patients with amyotrophic lateral sclerosis (ALS) and 18 age-matched neurologically normal individuals. The study revealed that the heterotopic neurons were scattered in the white matter, often adjacent to gray matter, that they immunoreacted with the antibody to synaptophysin, and that there were synaptic apparatuses on the surface of their somata and their neuronal processes. Bunina bodies and ubiquitin-positive inclusions such as Lewy body-like inclusions and skein-like inclusions, characteristic of anterior horn neurons of ALS, were present in the cytoplasm of the patients’ heterotopic neurons in the anterior or lateral column of the white matter. These findings suggest that heterotopic neurons in the anterior or lateral column have the characteristics of alpha motor neurons. The average number of heterotopic neurons observed in ALS patients was generally less than in normal subjects. This reduction was correlated with the severity of neuronal loss. The heterotopic neurons in ALS were less susceptible to the degenerative process as compared with spinal cord anterior horn cells. We assume that in this disease the heterotopic neurons may be degenerated and their number diminished after or concomitantly with the depletion of anterior horn neurons.
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  • 4
    ISSN: 1432-0533
    Keywords: Key words Dentatorubral-pallidoluysian atrophy ; Nuclear inclusion ; Ubiquitin ; Immunohistochemistry ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract We examined the brains and spinal cords of seven patients with clinicopathologically and genetically confirmed hereditary dentatorubral-pallidoluysian atrophy (DRPLA) using an antibody against ubiquitin, and found small, round immunoreactive intranuclear inclusions in both neurons and glial cells in various brain regions. Ubiquitinated neuronal intranuclear inclusions (uNIIs) were consistently found in the striatum, the pontine nuclei, the inferior olivary complex, the cerebellar cortex and the dentate nucleus. Ubiquitinated glial intranuclear inclusions (uGIIs) were found less frequently than uNIIs. Most of the inclusion-bearing nuclei were of an astrocytic nature. Immunostaining with an antibody against DRPLA protein revealed similar immunoreactive neuronal and glial intranuclear inclusions, but in much smaller in numbers compared with uNIIs and uGIIs. Electron microscopy showed that such inclusions were composed of granular and filamentous structures. These findings strongly suggest that, in DRPLA, the occurrence of uNIIs and uGIIs is directly related to the causative gene abnormality (an expanded CAG repeat encoding polyglutamine), that neurons are affected much more widely than previously recognized and that glial cells are also involved in the disease process.
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  • 5
    ISSN: 1432-0533
    Keywords: Key words Congenital myopathy ; Muscle fibers ; Ultrastructure ; Myofibrillar disarray
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract A 44-year-old man presenting with dyspnoic attacks was found to be affected with congenital myopathy, rigid spine, restrictive respiratory insufficiency and cardiomyopathy. Muscle biopsy showed type 1 fiber predominance (65.7%) and hypotrophy, and characteristic changes in 43.9% of the type 1 fibers, consisting in alternating pale and dark staining on alkaline ATPase reacted sections in a mosaic pattern. Ultrastructural examination demonstrated bands of myofibrils at right angles or skew to the remaining myofibrils transversing the fibers. Myofibrillar disarray was always associated with loss of the Z-discs and actin filaments, and often with aggregation of mitochondria. The muscle biopsy findings in this patient suggest a new entity of congenital myopathy with clinical features of rigid spine, cardiomyopathy and restrictive respiratory insufficiency, characterized by peculiar abnormalities of ATPase staining in a mosaic pattern and, ultrastructurally, by zones of disorientation of the sarcomeres.
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  • 6
    ISSN: 1432-0568
    Keywords: Key words Adult-type Leydig cells ; Endothelium ; 3β-HSD ; Ultrastructure ; Differentiation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract  In the biosynthesis of steroid hormones 3β-hydroxysteroid dehydrogenase (3β-HSD) is a key enzyme. The present report describes the subcellular localization of the enzyme in the fetal-type Leydig cells, the fibroblast-like precursors of adult-type Leydig cells and in endothelial cells of interstitial capillaries. Histochemical methods for light microscopy and ultracytochemical methods for electron microscopy were used on rat testes of postnatal day 15. 3β-HSD reactivity was located at subcellular levels by means of the ferricyanide method. A specific, distinct localization of reaction product in the form of copper ferrocyanide precipitates was observed on the membranes of the smooth endoplasmic reticulum not only in the fetal-type Leydig cells and the fibroblast-like precursors of adult-type Leydig cells, but also focally in the endothelial cells of interstitial blood capillaries. Topographically, the 3β-HSD-positive precursors were most often found in the outer layer of the boundary tissue and surrounding interstitial blood vessels. The capillaries with 3β-HSD-positive endothelial cells were usually located in the vicinity of 3β-HSD-positive Leydig cells. For the first time, 3β-HSD has been located at the subcellular level in precursors of adult-type Leydig cells and focally in capillary endothelial cells associated with them. Due to the close association between 3β-HSD-positive vascular endothelial cells and Leydig cells a paracrine relationship between the two cell types may be involved in the acute regulation of steroidogenesis by blood-borne luteinizing hormone.
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  • 7
    ISSN: 1432-0533
    Keywords: Key words Anorexia nervosa ; Myopathy ; Muscle biopsy ; Ultrastructure ; Protein-energy malnutrition
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Protein-energy malnutrition in anorexia nervosa is an under-recognised cause of muscle dysfunction. To characterise the skeletal myopathy that occurs in patients with severe anorexia nervosa, muscle function and structure were comprehensively examined in eight young adult female patients with severe (40%) self-induced weight loss. All of the patients showed impaired muscle function on strength and exercise measurement. The maximum voluntary contraction force for the patient group was significantly less than predicted values. Electromyography revealed myopathy in five of the patients, four of whom also had electro-physiological evidence of neuropathy. However, muscle biopsy specimens consistently showed myopathic changes with severe type 2 fibre atrophy but with no evidence of neuropathic changes. Ultrastructurally, there was separation and segmental loss of myofibrils and most biopsy samples contained abundant glycogen granules; we have previously reported that one of the most consistent biochemical abnormalities in these patients is impaired ischaemic lactate responses to forearm exercise. The result of severe protein-energy malnutrition on the musculo-skeletal system is a metabolic myopathy. Although the patients admitted to a variety of abnormal dieting behaviours, such as over-exercising and self-induced vomiting, no association was found between any of these and quantitative histological changes in the muscle biopsy samples. It is recommended that myopathy in anorexia nervosa be treated by instituting an appropriate refeeding programme.
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    Springer
    Anatomy and embryology 197 (1998), S. 135-141 
    ISSN: 1432-0568
    Keywords: Key words Interstitial cells of Cajal ; Ultrastructure ; Gap junction ; Intestine ; Motility
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract  Interstitial cells forming many large gap junctions in the region of the deep muscular plexus of the rat small intestine were studied by electron microscopy and by three-dimensional cell models reconstructed from serial ultrathin sections. Two different profiles of cells were observed. Cells of the first profile are characterized by an elongated cell shape and by less electron-dense cytoplasm, containing many mitochondria, well-developed Golgi apparatus and free ribosomes. They mainly connect with smooth muscle cells of the main circular layer. In a three-dimensional cell model, the total area of the gap junctions occupies 1.3% of the cell surface. Cells of the second profile are characterized by the frequent occurrence of slender cytoplasmic processes, higher electron-dense cytoplasm, containing mitochondria, Golgie apparatus and well-developed rough endoplasmic reticulum, and numerous caveolae on the cell membrane. In this cell model, gap junctions occupy 0.8% of the cell surface. The ratio of gap junctions with the same profile of cells to the total gap junction area is 37.7%, which is more than three times greater than the 9.9% in cells of the first profile. These cells were closely associated with nerve terminals. It is likely that these cells with different profiles constitute subtypes with each other and cooperate for regulation of intestinal motility via the transmission of nerve signals.
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  • 9
    ISSN: 1432-0533
    Keywords: Key words Congenital myopathy ; morphometry ; Ultrastructure ; Fetal myogenesis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Centronuclear myopathy (CNM) is a congenital myopathy which manifests itself as a severe neonatal (also termed myotubular myopathy), early-onset, or adult form. The histological pattern of each is marked by a considerable number of nuclei of muscle fibers being internally placed. Owing to their remote resemblance to myotubes, and their expression of developmentally regulated proteins, most authors now favor the concept that myogenesis is arrested or delayed in this disease. We here present two muscle biopsy specimens of a patient with early-onset CNM, taken at the age of 5 months and 14 years, respectively. The first biopsy sample contained internally placed nuclei in 7% of the muscle fibers, abundant minute myotubes, and hypertrophic muscle fibers. The second biopsy sample showed internally placed nuclei in 40% of the muscle fibers, and hypotrophic fibers. We suggest that the histological findings in early-onset CNM are the result of a complex dynamic process, which includes a delay in maturation.
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  • 10
    ISSN: 1432-0533
    Keywords: Key words Aging ; Blood-brain barrier ; Horseradish peroxidase ; Senescence-accelerated mouse ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The ultrastructural features of microvessels showing increased permeability to intravenously injected horseradish peroxidase (HRP) were examined in the olfactory bulbs of senescence-accelerated prone mice (SAMP8), which showed age-related deficits in learning and memory, and senescence-accelerated resistant mice (SAMR1), which did not show the age-related deficits. HRP was visualized with tetramethyl benzidine (TMB) and diaminobenzidine (DAB) for light and electron microscopic examination, respectively. In the olfactory bulbs of 13-month-old SAMP8 mice, the staining reaction with TMB for HRP appeared in the neuropil of central area (granule cell layer and subependymal layer), in the pia mater and in the vascular wall. Some vessels located in the central area showed several changes observed at the ultrastructural level. The cytoplasm of the endothelial cells, especially in the arterioles, was segmentally thickened and contained numerous vesicles and vacuoles, some of which were HRP positive. The endothelial cell surface was occasionally undulated with microvillous protrusions. Membranous inclusions within the basal lamina, suggesting the cellular (presumably pericytal) degeneration, were frequently observed, especially in venules. The collagen deposits were occasionally observed in the subendothelial space of some vessels. Perivascular cells with vacuolated inclusions or lipid-like droplets were present around some vessels in the central area of the olfactory bulbs of aged SAMP8 mice. On the other hand, in the microvessels located in the areas negative for HRP-TMB reaction, except the vessel walls, the cytoplasm of the endothelial cells with smooth luminal surface was flattened and some vesicles located there contained HRP-DAB reaction product. Weak staining reaction with TMB for HRP appeared also in the central area of the olfactory bulbs of 3-month-old SAMP8 mice and 3- and 13-month-old SAMR1 mice. The cytoplasm of the endothelial cells in the olfactory bulbs of these mice was focally thickened and contained some cytoplasmic vesicles. Occasionally, the endothelial cell surface was moderately undulated with few microvillous protrusions. Membranous inclusions within the basal lamina were not observed in these animals. These findings indicate that the endothelial cells and pericytes in some vessels located in the central area of the olfactory bulb of aged SAMP8 mice, which show staining reaction with TMB for HRP, are ultrastructurally changed, suggesting their altered functions.
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  • 11
    ISSN: 1432-069X
    Keywords: Key words Barrier function ; pH ; Stratum corneum ; Lamellar body ; Lipid content ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Epidermal permeability barrier homeostasis requires the postsecretory processing of polar lipid precursors into nonpolar lipid products within the stratum corneum (SC) interstices by a family of lipid hydrolases. A specific requirement for β-glucocerebrosidase (β-GlcCer’ase), which exhibits a distinct acidic pH optimum, is particularly well documented. Therefore, we sought to determine whether the recovery of the barrier after acute insults requires acidification of the SC. We examined permeability barrier recovery by assessing changes in transepidermal water loss (TEWL), SC membrane ultrastructure utilizing ruthenium tetroxide (RuO 4 ) postfixation, and β-GlcCer’ase activity by in situ zymography at an acidic vs neutral pH. Barrier recovery proceeded normally when acetone-treated skin was exposed to solutions buffered to an acidic pH. In contrast, the initiation of barrier recovery was slowed when treated skin was exposed to neutral or alkaline pH, regardless of buffer composition. In addition, enhancement of the alkaline buffer-induced delay in barrier recovery occurred with Ca 2+ and K + inclusion in the buffer. Moreover, the pH-dependent alteration in barrier recovery appeared to occur through a mechanism that was independent of Ca 2+ - or K + -controlled lamellar body secretion, since both the formation and secretion of lamellar bodies proceeded comparably at pH 5.5 and pH 7.4. In contrast, exposure to pH 7.4 (but not pH 5.5) resulted in both the persistence of immature, extracellular lamellar membrane structures, and a marked decrease in the in situ activity of β-GlcCer’ase. These results suggest first that an acidic extracellular pH is necessary for the initiation of barrier recovery, and second that the delay in barrier recovery is a consequence of inhibition of postsecretory lipid processing.
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  • 12
    Electronic Resource
    Electronic Resource
    Springer
    Zeitschrift für Lebensmittel-Untersuchung und -Forschung 206 (1998), S. 38-43 
    ISSN: 1431-4630
    Keywords: Key words Starch ; Gels ; Kamaboko ; Surimi ; Gelatinization ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract  The purpose of this work was to study the changes undergone by starch during heat-induced surimi gel preparation either with or without added egg white, and their effects on the structure of gels using light and scanning electron microscopy. Gels were made from SA-grade Alaska pollack (Theragra chalcogramma) surimi with: (1) salt (3%, w/w); (2) salt and waxy corn starch (3% and 5%, respectively w/w); or (3) salt, waxy corn starch and egg white (3%, 5% and 5%, respectively, w/w). Final moisture was adjusted to 73% or 83%. The gels were prepared by prior setting (40°C, 30 min, followed by 90°C, 30 min) or cooking (90°C, 30 min). The prepared gel was frozen and stored at –20°C (±1°C) until analysis. Samples were observed by light and scanning electron microscopy. The results show that the starch granules alter according to the processing conditions, with the predominance of crystalline or amorphous morphology depending upon the availability of heat and water. Large cavities formed in the protein gel matrix during setting can trap water; as a result, water availability is limited for starch to swell and gelatinize even in the high-moisture gel.
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  • 13
    Electronic Resource
    Electronic Resource
    Springer
    Der Pathologe 19 (1998), S. 373-378 
    ISSN: 1432-1963
    Keywords: Schlüsselwörter Metaplastische Brustdrüsenkarzinome ; Plattenepithelmetaplasie ; Plattenepithelkarzinom ; Immunhistologie ; Elektronenmikroskopie ; Zytophotometrie ; Key words Pure squamous cell carcinoma ; Mammary gland ; Squamous metaplasia ; Immunohistology ; Cytophotometry ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Summary Squamous metaplasia can be demonstrated in about 4% of all invasive carcinomas of the breast. Primary squamous cell carcinomas of the breast are rare, since they occur in less than 1% of all primary invasive breast carcinomas. In order to classify a breast tumor as a primary squamous cell carcinoma one must exclude an epidermal origin, especially from the nipple region and the possibility of metastatic infiltration of the breast by a squamous cell carcnoma from a different location. Causative and formal pathogenesis of primary squamous cell carcinoma of the breast is not clear. A pluripotent embryonal stem cell origin is discussed, considering the phylogenetic descent of the mammary gland from skin appendages. Squamous metaplasia is also suggested to be a precursor of squamous cell carcinoma. Here endocrine stimulation and chronic inflammation may both play an inductive role. The number of published cases of squamous cell carcinomas developing years and decades after implantation of silicon prostheses has increased in recent years. These tumors probably develop on top of squamous metaplasia induced by the inflammatory pseudocapsule. Estimating the prognosis and therapeutic management in patients with squamous cell carcinoma of the breast should follow the same guidelines as for other squamous cell cancers.
    Notes: Zusammenfassung Plattenepithelmetaplasien werden bei etwa 4% aller invasiven Brustdrüsenkarzinome beschrieben. Reine Plattenepithelkarzinome der weiblichen Brustdrüse sind mit einem Anteil von wahrscheinlich unter 1% an allen invasiven epithelialen Tumoren der Mamma selten. Von einem primären Plattenepithelkarzinom der Brustdrüse darf nur gesprochen werden, wenn zum einen der Ursprung von der Epidermis, insbesondere auch im Bereich des Mamillentrichters ausgeschlossen ist und zum anderen keine metastatische Infiltration in die Brustdrüse durch ein Plattenepithelkarzinom anderer Organlokalisation vorliegt. Die kausale und formale Pathogenese der primären Plattenepithelkarzinome der Brustdrüse ist unklar. Zum einen wird ein Ursprung von pluripotenten embryonalen Stammzellen diskutiert, wobei bedacht wird, daß die Brustdrüse entwicklungsgeschichtlich ein Hautanhangsgebilde darstellt. Zum anderen werden Plattenepithelmetaplasien als Vorstufe der Plattenepithelkarzinome diskutiert, wobei neben einer endokrinen Induktion auch länger bestehende Entzündungsreize eine Rolle spielen sollen. In den letzten Jahren wird immer häufiger darüber berichtet, daß oft Jahrzehnte nach Implantation von Silikonprothesen periprothetische Plattenepithelkarzinome entstehen, die wahrscheinlich über die Stufe einer Plattenepithelmetaplasie der entzündlichen Prothesenpseudokapsel entstehen. Die Abschätzung der Prognose und therapeutische Maßnahmen bei primären Plattenepithelkarzinomen der Brustdrüse sollten an den Erfahrungen mit Plattenepithelkarzinomen anderer Organlokalisation ausgerichtet werden.
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  • 14
    ISSN: 1432-2145
    Keywords: Key words Abies ; Egg cell ; Plastid inheritance ; RFLP ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  The ultrastructure of egg cells in Abies alba was examined to elucidate the lack of maternal inheritance of plastids. Before fertilization, maternal plastids are absent in the perinuclar zone containing mainly mitochondria and smooth endoplasmic reticulum. During egg cell development the maternal plastids are transformed into large inclusions which are situated mostly towards the periphery of the egg cell, and finally disintegrate. As a consequence, they do not participate in zygote formation. RFLP analysis of cpDNA of parental trees and their F1 interspecific hybrids (A. alba×A. numidica, A. alba×A. nordmanniana, A. nordmanniana×A. Alba) using HindIII and BamHI showed a paternal mode of cpDNA inheritance. Paternal inheritance has also been found with PCR/RFLP analysis of cpDNA from parental trees and their hybrids (A. alba×A. pinsapo, A. pinsapo×A. alba, A. pinsapo×A. numidica) using ApaI and HaeIII digests, as well as in the crosses of A. cephalonica×A. nordmanniana, A. nordmanniana×A. cephalonica, A. cephalonica×A. numidica using TagI digests.
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  • 15
    Electronic Resource
    Electronic Resource
    Springer
    Sexual plant reproduction 11 (1998), S. 121-130 
    ISSN: 1432-2145
    Keywords: Key words Egg cell ; Parthenogenesis ; Synergid ; Ultrastructure ; Wheat ; Zygote
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  The ultrastructure of the egg apparatus of the sexual (aestivum)-Salmon line (aS) and the isogenic but alloplasmic (kotschyi)-Salmon line (kS) of the Salmon system of wheat was studied by transmission electron microscopy 3 days before and during anthesis. Additionally, the zygotic stage of aS, 17 h after pollination, was included. Metabolic activity of egg cells from the sexual line aS was low 3 days before anthesis and increased dramatically after pollination and fertilization. This timing of increased activity was evident because of changes occurring in the egg cell nucleus and nucleolus, polysomes, endoplasmic reticulum and Golgi apparatus, and the completion of the cell wall around the zygote. In contrast to the sexual line, the egg cell of the parthenogenetic line showed high activity 3 days before anthesis. The metabolic and ultrastructural characters observed in the nucleus and cytoplasm of the kS line 3 days before and during anthesis corresponded with those of the isogenic sexual line aS during anthesis and 17 h after pollination, respectively. High metabolic activity observed in the persistent synergid of kS may be connected with the occurrence of additional embryos in seeds (twins) of this line.
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  • 16
    ISSN: 1432-072X
    Keywords: Key words Magnetic bacteria ; Biomineralization ; Magnetite ; 16S rRNA ; In situ hybridization ; Ultrastructure ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Natural enrichments of magnetic bacteria from the Itaipu lagoon near Rio de Janeiro were dominated by coccoid-to-ovoid morphotypes that produced unusually large magnetosomes. To determine the phylogenetic position of these unusual microorganisms, 16S rRNA genes were retrieved from bacteria magnetically separated from sediment of the Itaipu lagoon by in vitro amplification and cloning of PCR products into a plasmid vector. Partial sequencing of the obtained clones revealed two clusters of closely related sequences affiliated to a distinct lineage consisting exclusively of magnetic bacteria within the α-subclass of Proteobacteria. For a detailed phylogenetic analysis, several almost complete sequences of the 16S rRNA genes were determined. One representative clone of each cluster provided a PCR template for the in vitro transcription of group-specific polynucleotide probes complementary to a variable region of the 16S rRNA molecule. At least three different morphotypes of magnetic bacteria were reliably identified by post-embedding hybridization of ultra-thin sections. Electron microscopic analyses of hybridized cells enabled for the first time a detailed description of the morphological variety and ultrastructure of phylogenetically identified, uncultured magnetic bacteria. Two distinct coccoid bacteria were identified by the transcript probe complementary to the 16S rRNA sequence mabrj12, whereas the probe complementary to the sequence mabrj58 allowed the identification of an ovoid morphotype that displayed magnetosomes with the largest volumes observed to date.
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  • 17
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 292 (1998), S. 275-282 
    ISSN: 1432-0878
    Keywords: Key words Interstitial cells (Cajal) ; Large intestine ; Fluorescent dyes ; Vital staining ; Ultrastructure ; Mouse (BALB/c)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  Interstitial cells of Cajal (ICCs) are believed to be a major element in generating the spontaneous rhythm of the gastrointestinal tract. A prominent problem in the study of these cells has been the difficulty in observing them in intact tissues. We used the lipophilic dye DiI to stain ICCs in the submucosal-circular muscle border of freshly dissected mouse colon. The placement of small DiI crystals in this area resulted in the labeling of ICC-like cells. Two main morphological cell types, viz., bipolar and multipolar, were noted. Bipolar cells had two primary processes emerging from the poles of an elongated soma. The mean length of these processes was 78.7 μm. These cells constituted 42.3% of the sample (n=105). Multipolar cells (54.3% of total) had a less elongated soma and extended 3–6 main processes whose mean length was 56.3 μm. These processes showed no preferred direction. The length of the primary processes of bipolar cells was 40% greater than that of multipolar cells (P〈0.02). Three cells (2.9%) had only one primary process. The DiI stain could be converted into a stable electron-opaque product. Electron-microscopic observations showed that these cells had the typical appearance of ICCs reported in previous studies. This staining method should be useful for physiological investigations of ICCs in gastrointestinal tissues.
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  • 18
    ISSN: 1432-0878
    Keywords: Key words Cutaneous scent glands ; Apocrine glands ; Myoepithelial cells ; Holocrine glands ; Ultrastructure ; Lectins ; Cytokeratins ; Impala ; Aepyceros melampus (Artiodactyla)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  The cutaneous glands of the forehead and the metatarsus were studied by histological and histochemical methods and electron microscopy in adult male and female impalas in various seasons of the year. All glandular areas consist of apocrine and holocrine glands, which, however, occur in different proportions. Our findings in the apocrine gland cells suggest (1) the synthesis and exocytosis of a glycoproteinaceous secretory product stored in secretory granules, (2) typical apocrine secretion of the transformed apical cytoplasm, and (3) transepithelial fluid transport. The Golgi apparatus and apical membrane have binding sites for several lectins (PNA, HPA, RCA I, WGA). Cytokeratins 7, 14 and 19 are expressed at various intracellular localizations, suggesting an active role in the secretory mechanisms. The glands of the male forehead show marked seasonal changes in activity that are correlated with the main phases of the reproductive cycle, with the highest cellular activity occurring during the rut in April/May. The female forehead glands are only moderately developed and do not undergo seasonal changes. The metatarsal glands are of equal size in males and females and show no seasonal changes in activity. This study supports the hypothesis that (1) forehead glands in the male have a signaling role in the rut and (2) the metatarsal glands have a more general, probably social role maintaining and restoring contact between herd members.
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  • 19
    Electronic Resource
    Electronic Resource
    Springer
    Cell & tissue research 293 (1998), S. 165-171 
    ISSN: 1432-0878
    Keywords: Key words Muscle injury ; Cytoskeleton ; Sarcomere organisation ; Immunohistochemistry ; Ultrastructure ; Rabbit (New Zealand White)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Immunohistochemical and electron-microscopic techniques were used to analyze the extensor digitorum longus muscles of New Zealand White rabbits 1 h, 1 day, 3, 7, and 28 days after repetitive eccentric contractions. Loss of the cytoskeletal protein desmin was the earliest manifestation of injury. Apart from 1 h post-exercise, all desmin-negative fibers stained positively with antibody to plasma fibronectin, indicating loss of cellular integrity accompanying cytoskeletal disruption. Fiber sizes were significantly increased from 1–7 days after exercise. The large (hyaline) fibers found in histological sections after repetitive eccentric contractions resulted from segmental hypercontraction of the fiber. This phenomenon occurred proximally and distally to plasma membrane lesions of the muscle fiber and necrosis and manifested itself as very short sarcomere lengths. Thus, in serial sections, staining characteristics, sizes and shapes of one and the same fiber often varied dramatically. We conclude that the following sequence of events occurs: cytoskeletal disruptions, loss of myofibrillar registry, i.e., Z-disk streaming and A-band disorganization, and loss of cell integrity as manifested by intracellular plasma fibronectin stain, hypercontracted regions, and invasion of cells. When a fiber is disrupted, the remaining intact fibers apparently take up the tension put on the muscle and later fewer fibers are subjected to eccentric contractions.
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  • 20
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    Cell & tissue research 294 (1998), S. 253-260 
    ISSN: 1432-0878
    Keywords: Key words P2X1 receptor ; Ultrastructure ; Cerebellum ; Rat (Wistar)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  The distribution of the P2X1 subtype of purinoceptors associated with the extracellular activities of ATP was studied in the rat cerebellum at the electron-microscope level. Receptors were labelled with peroxidase-antiperoxidase and the avidin-biotin-peroxidase complex for immunocytochemistry. Immunoreactivity to P2X1 receptors was localized in subpopulations of synapses between varicosities of parallel fibres of granule cells and dendritic spines of Purkinje cells. Unlabelled varicosities of parallel fibres formed asymmetric synapses with labelled dendritic spines, whereas labelled varicosities of parallel fibres formed asymmetric synapses with unlabelled dendritic spines. P2X1 immunoreactivity was also localized in some astrocyte processes. The functional significance of these findings is discussed.
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  • 21
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    Cell & tissue research 294 (1998), S. 367-375 
    ISSN: 1432-0878
    Keywords: Key words Neurons ; Glia ; Tracheae ; Wing ; Ultrastructure ; Moth ; Manduca sp.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  This ultrastructural examination of sensory nerves of the Manduca wing has revealed that extensive remodeling occurs among insect sensory neurons and their associated glial cells between pupation and adult emergence. Systematic counts of axons in particular wing nerves throughout adult development have shown that a decrease in axon number per nerve occurs after day 6. The neurons and glial cells that die are believed to be cells present at pupation that have no apparent sensory function but that probably function as guidance scaffolding for neurons and glia that are born after pupation. Despite the loss of several axons from each wing nerve, these nerves continue to grow in diameter during the latter half of adult development as some of the surviving axons increase severalfold in diameter. Each growing wing nerve in turn apparently functions as a scaffold for the proximal to distal growth of adult tracheae. A correspondence exists between adult nerve pathways and adult tracheal pathways, with each trachea maintaining intimate contact with a wing nerve along its entire length.
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  • 22
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    Cell & tissue research 291 (1998), S. 549-559 
    ISSN: 1432-0878
    Keywords: Key words Endolymphatic sac ; Ultrastructure ; Fluid transport ; Otoconia ; Newt ; Cynops pyrrhogaster (Urodela)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  The ultrastructure of the endolymphatic sac (ES) of the late stage larva of the Japanese red-bellied newt, Cynops pyrrhogaster (stage 57), was examined by light and transmission electron microscopy. The two endolymphatic sacs are located at the dorsal-medial side of the otic vesicle on the dorsal-lateral side of the midbrain in the cranial cavity. The wall of the sac is composed of a layer of cubical epithelial cells with loose, interposed intercellular spaces. The sac contains a large luminal cavity, in which endolymph and numerous otoconia are present. The epithelial cells of different portions of the sac have a similar structure. These cells contain an abundance of cytoplasmic organelles, including ribosomes, Golgi complexes, and numerous vesicles. Two types of vesicles are found in the epithelial cells: the “floccular” vesicle and the “granular” vesicle. The floccular vesicles are located in the supra- and lateral-nuclear cytoplasm and contain flocccular material. The granular vesicles have a fine granular substance and are usually situated apposed to the apical cell membrane. The granular vesicles are suggested to be secreted into the lumen, while the floccular vesicles are thought to be absorbed from the lumen and conveyed to the intercellular spaces by the epithelial cells. The apical surfaces of the epithelial cells bear numerous microvilli. Apparently floating cells, which bear long microvilli on the free surfaces, are observed in the lumen of the ES. Based on the fine structure, the function of the endolymphatic sac of the newt Cynops pyrrhogaster is discussed.
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  • 23
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    Cell & tissue research 293 (1998), S. 253-269 
    ISSN: 1432-0878
    Keywords: Key words Septate junctions ; Ultrastructure ; Permeability ; Ions ; Epithelium ; Photoreceptor ; Hirudo medicinalis (Hirudinea)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  The leech photoreceptor forms a unicellular epithelium: every cell surrounds an extracellular “vacuole” that is connected to the remaining extracellular space via narrow clefts containing pleated septate junctions. We analyzed the complete structural layout of all septa within the junctional complex in elastic brightfield stereo electron micrographs of semithin serial sections from photoreceptors infiltrated with colloidal lanthanum. The septa form tortuous interseptal corridors that are spatially continuous, and open ended basally and apically. Individual septa seem to be impermeable to lanthanum; interseptal corridors form the only diffusional pathway for this ion. The junctions form no diffusion barrier for the electron-dense tracer Ba2+, but they hinder the diffusion of various hydrophilic fluorescent dyes as demonstrated by confocal laser scanning microscopy (CLSM) of live cells. Even those dyes that penetrate gap junctions do not diffuse beyond the septate junctions. The aqueous diffusion pathway within the septal corridors is, therefore, less permeable than the gap-junctional pore. Our morphological results combined with published electrophysiological data suggest that the septa themselves are not completely tight for small physiologically relevant ions. We also examined, by CLSM, whether the septate junctions create a permeability barrier for the lateral diffusion of fluorescent lipophilic dyes incorporated into the peripheral membrane domain. AFC16, claimed to remain in the outer membrane leaflet, does not diffuse beyond the junctional region, whereas DiIC16, claimed to flip-flop, does. Thus, pleated septate junctions, like vertebrate tight junctions, contribute to the maintenance of cell polarity.
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  • 24
    ISSN: 1432-0878
    Keywords: Key words Angiogenesis ; Capillary growth ; Prazosin ; Shear stress ; Skeletal muscle ; Ultrastructure ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  Chronic vasodilatation represents a stimulus for capillary growth associated with increased luminal shear stress. We have examined the ultrastructure of more than 2000 capillaries to establish whether the sequence of angiogenesis in response to this stimulus is similar to that described during development and under pathological circumstances. Administration of the α1-blocker prazosin to rats for 2 weeks led to a greater capillary length density in extensor hallucis proprius muscles without any change in capillary tortuosity: J v(c,f)=262±54 compared with 350±17 mm–2, control compared with prazosin (P〈0.002). There were obvious signs of endothelial cell (EC) activation after prazosin treatment, including an increased proportion of capillaries with rough endoplasmic reticulum, large cytoplasmic vacuoles, thickened endothelium and an irregular luminal surface. Capillaries from control muscles had a maximum of three ECs in cross section, whereas four ECs were noted in 0.8+0.5% of capillaries after 1 week (n.s.) and 2.5±0.9% after 2 weeks (P〈0.01) of treatment. This could be due to elongation and/or migration of ECs, as cell proliferation has not been described at these time points. There was also an increase in the proportion of capillaries having a narrow, slit-like lumen (1.7±0.8% of controls; 7.1±1.9% at 1 week; 8.8±2.5% at 2 weeks; P〈0.02), some of which were smaller in size (less than 2 μm diameter) than in controls (3–5 μm) and/or “seamless”, i.e. lacking EC junctions. These may represent newly formed vessels. Focal discontinuity of the basement membrane and abluminal EC processes were rarely seen, and capillary growth by abluminal sprouting appeared to be very infrequent (less than 0.001% of profiles). Of more importance was growth starting from the luminal side. Significantly more thin cytoplasmic processes were observed protruding into the lumen of capillaries after 1 week (47.5±6.2%, P〈0.001) and 2 weeks of prazosin (34.2±5.5%, P〈0.05) than in control vessels (16.7±3.9%). Some of these traversed the entire lumen and connected with endothelium of the opposite side, probably involving membrane fusion, resulting in the appearance of a double lumen. Individual capillaries with a complete double lumen were observed after 2 weeks’ prazosin but comparatively rarely, in only four out of six muscles. These findings indicate a pattern of luminal growth which is completely different from intussusceptive growth previously described during development, and from the abluminal capillary sprouting seen under pathological circumstances.
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  • 25
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    Protoplasma 204 (1998), S. 155-169 
    ISSN: 1615-6102
    Keywords: Spores ; Ultrastructure ; Entorrhiza ; Microbotryum ; Tilletia ; Ustilago
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The concept and nomenclature for the elements of teliospore walls in smut fungi are presented and a survey of teliosporogenesis is given, as seen by light and transmission electron microscopy. Four developmental types are distinguished: the Ustilago, Microbotryum, Tilletia, and Entorrhiza type. In the Ustilago type, sporogenous hyphae are completely segmented into teliospore initials which are embedded in a hyaline matrix formed by gelatinised hyphal walls (found in species ofAnthracoidea, Cintractia, Heterotolyposporium, Kuntzeomyces, Macalpinomyces, Melanopsichium, Sporisorium, Testicularia, Tolyposporium junci, Trichocintractia, and species ofUstilago infecting members of the family Poaceae). In the Microbotryum type, septate sporogenous hyphae are also completely segmented into teliospore initials, however, they are not surrounded by a hyaline matrix (Microbotryum, Sphacelotheca, Ustilago spp. infecting dicotyledons). A yeast-like budding of teliosporogenic cells is observed for some species ofMicrobotryum, Sphacelotheca, andUstilago infecting dicotyledons. In the Tilletia type, teliospores differentiate locally in the sporogenous hyphae, in an apical or intercalary position, without a hyaline matrix (Conidiosporomyces, Doassinga, Entyloma, Erratomyces, Ingoldiomyces, Neovossia, Oberwinkleria, Rhamphospora, Tilletia). In all these types, the teliospore initials first develop a hyaline sheath under which the ornamentation, the exosporium, sometimes a middle layer, and the endosporium are successively deposited by the fungal cell. In the Entorrhiza type, the teliospores develop inside vital host cells with the wall of the sporogenous hypha included into the teliospore wall. The fungus develops a middle layer and an electron-transparent endosporium inside the hyphal wall while a layer forming the ornamentation is deposited onto the hyphal wall, probably by vesicles of dictyosomes of the host cell.
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  • 26
    ISSN: 1615-6102
    Keywords: Neck cell proliferation ; Binucleate ; Douglas fir ; Conifers ; Genetic instability ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary To study the effect of culturing on megagametophytes of Douglas fir (Pseudotsuga menziesii) and hybrid larch (Larix × eurolepis), cones were collected at the time of fertilization and the megagametophytes were removed, then placed on medium. We used a modified Murashige and Skoog medium supplemented with 5% lactose and 10% polyethylene glycol 4000. A variety of cell types proliferated including prothallial, neck, and jacket cells. Some of these multiplying cells showed a binucleate condition. The prothallial cells of the apex divided and expanded. The neck cells formed clusters composed of more cells than normally found in situ; though otherwise they showed ultrastructural similarity to neck cells in situ. These neck cells had large numbers of active Golgi complexes, numerous large and small vacuoles, coated vesicles, smooth vesicles, a well-developed endoplasmic reticulum, and thickened cell walls. These are the first reports of neck cell multiplication and induction of a binucleate state for gymnosperm megagametophyte cells in vitro.
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  • 27
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    Protoplasma 201 (1998), S. 30-37 
    ISSN: 1615-6102
    Keywords: Cell-to-cell communication ; Plasmodesmata ; Ultrastructure ; Wounding ; 2-Deoxy-D-glucose
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The transport of ions and metabolites through plasmodesmata has been thought to be controlled at the neck region where the cytoplasmic annulus is constricted and where callose has also been localised. In order to determine the possible structural and functional effects of callose, its deposition was inhibited through incubation of the plant tissue with 2-deoxy-D-glucose (DDG) for 1 h prior to fixation in 2.5% glutaraldehyde. The inhibition of callose formation was monitored through aniline blue-induced fluorescence of callose. The neck region of the plasmodesmata fromAllium cepa L. roots treated with DDG exhibited a funnel-shaped configuration. This is in contrast to the plasmodesmata from tissue not incubated with DDG, which exhibited constricted necks similar to those previously reported. Both initial dissection and glutaraldehyde fixation induced neck constriction in plasmodesmata, however, dissection of tissue increased the frequency of constrictions. The inhibition of callose formation by chemical means showed that the neck constrictions and raised collars in this area are artefacts due to physical wounding and glutaraldehyde fixation. The external electron-dense material observed when tannic acid is included in the primary fixative appears to be unrelated to the deposition of callose at the neck region.
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  • 28
    ISSN: 1615-6102
    Keywords: Chloroplast development ; Cotton ; Fluorescence induction kinetics ; Ultrastructure ; Immunocytochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Many of the studies of chloroplast ontogeny in higher plants have utilized suboptimal conditions of light and growth to assess development. In this study, we utilized structural, immunological, and physiological techniques to examine the development of the chloroplast in fieldgrown cotton (Gossypium hirsutum cv. “MD 51 ne”). Our youngest leaf sample developmentally was completely folded upon itself and about 0.5 cm in length; leaves of this same plastochron were followed for three weeks to the fully expanded leaf. The chloroplasts at the earliest stage monitored had almost all of the lamellae in small, relatively electron-opaque grana, with relatively few thylakoids which were not appressed on at least one surface. During the development of the thylakoids, the membranes increase in complexity, with considerable stroma lamellae development and an increase in the number of thylakoids per granum. Besides the increase in complexity, both the size and numbers of the chloroplast increase during the development of the leaf. Developmental changes in six thylakoid proteins, five stromal proteins, and one peroxisomal protein were monitored by quantitative immunocytochemistry. Even at the earliest stages of development, the plastids are equipped with the proteins required to carry out both light and dark reactions of photosynthesis. Several of the proteins follow three phases of accumulation: a relatively high density at early stages, a linear increase to keep step with chloroplast growth, and a final accumulation in the mature chloroplast. Photosystem-II(PS II)-related proteins are present at their highest densities early in development, with an accumulation of other parts of the photosynthetic apparatus at a latter stage. The early accumulation of PS-II-related proteins correlates with the much lower ratio of chlorophylla tob in the younger leaves and with the changes in fluorescence transients. These data indicate that some of the conclusions on chloroplast development based upon studies of intercalary meristems of monocots or the greening of etiolated plants may not be adequate to explain development of chloroplasts in leaves from apical meristems grown under natural conditions.
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  • 29
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    Protoplasma 201 (1998), S. 101-109 
    ISSN: 1615-6102
    Keywords: Kinetochore ; Kinetoplastida ; Intranuclear microtubules ; Mitosis ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The three-dimensional ultrastructural organization of the mitotic apparatus ofDimastigella mimosa was studied by computer-aided, serial-section reconstruction. The nuclear envelope remains intact during nuclear division. During mitosis, chromosomes do not condense, whereas intranuclear microtubules are found in close association with six pairs of kinetochores. No discrete microtubule-organizing centers, except kinetochore pairs, could be found within the nucleus. The intranuclear microtubules form six separate bundles oriented at different angles to each other. Each bundle contains up to 8 tightly packed microtubules which push the daughter kinetochores apart. At late anaphase only, midzones of these bundles align along an extended interzonal spindle within the narrow isthmus between segregating progeny nuclei. The nuclear division inD. mimosa can be described as closed intranuclear mitosis with acentric and separate microtubular bundles and weakly condensed chromosomes.
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  • 30
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    Plant systematics and evolution 210 (1998), S. 25-39 
    ISSN: 1615-6110
    Keywords: Cyanophyta ; Cyanobacteria ; Cyanothece ; Synechococcus ; Cyanobium ; Ultrastructure ; nucleoids ; taxonomy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The fine structure of the type species of the genusCyanothece Komárek 1976,C. aeruginosa, is described and compared with the main cytological characteristics of morphologically related members of the generaCyanobium, Cyanobacterium andSynechococcus. Several morphological features, such as cell walls with thick outer layers containing a special type of vesicles, position of thylakoids, “keritomy” (net-like appearance of protoplast caused by arrangement of thylakoids, net-like nucleoids and/or by tendency to form intrathylakoidal spaces) and a special structure of mucilaginous envelopes were found to be characteristic of this genus, supporting its separate position among coccal cyanoprokaryotes (cyanobacteria, cyanophytes). The taxonomic significance of ultrastructural features in all mentioned genera is discussed.
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  • 31
    ISSN: 1615-6102
    Keywords: Spore balls ; Germ areas ; Ultrastructure ; Phylogeny
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Special features of teliospores in smut fungi are described, including teliospore connections, appendages, and germ pores. Balls of teliospores in species of many different genera cohere by remnants of hyphal walls, sheaths, and sometimes interlocking ornamentation. Teliospores are connected in pairs in species ofMycosyrinx andGeminago by special local structures. Appendages can be formed locally by persistent material from the sheath (Cintractia, Anthracoidea, Sphacelotheca), thickened parts of the spore wall (e.g.,Georgefischeria, Jamesdicksonia, Rhamphospora, Tolyposporella), or persistent walls of sporogenous hyphae (Rhamphospora, genera of the Tilletia relationship). Species ofGeorgefischeria, Jamesdicksonia, andTolyposporella have teliospore walls composed of more than three layers of different electron density. “Germ areas” corresponding to thinner parts of the spore wall are known, e.g., for species ofAnthracoidea, Cintractia, andUstilago infecting members of the family Poaceae, while distinct germ pores, one per teliospore, are found in some species ofThecaphora, “Tolyposporium”, andSporisorium. Teliospores ofMycosyrinx cissi have a germination ring. Characteristics of teliospores are used to discuss the phylogeny of smut fungi. A phylogenetic tree in accordance with teliospore characteristics is compared to those obtained from ultrastructural characteristics of host-parasite interaction, of septal pores, and from sequence data. Aspects of teliospore development help to define taxa at a high systematic level (Entorrhizales, Ustilaginales, Tilletiales/Entylomatales, Microbotryaceae), while details of ornamentation ontogeny delimit groups of genera (e.g., genera related toUstilago on members of the Poaceae andSporisorium, Cintractia andAnthracoidea, Tilletia) or single genera (e.g.,Melanopsichium, Dermatosorus, Mycosyrinx, Doassinga, Rhamphospora). Types of ornamentation (warty, reticulate), middle layers, teliospore balls, and germ pores evolved repeatedly by convergence. The smut teliospore itself probably evolved independently at least twice, or perhaps three (or more) times, in the Microbotryales, in the Entorrhizales, and in a common ancestor of the remainder of the Ustilaginomycetes.
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  • 32
    ISSN: 1615-6102
    Keywords: Spores ; Ultrastructure ; Microbotryum ; Tilletia ; Tolyposporium ; Ustilago
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The walls of mature teliospores and the development of ornamentation, as seen by transmission electron microscopy, are described for 37 genera of smut fungi, based on observations of ca. 120 species and on literature. Structural diversity of mature teliospore walls is due to differences in spore wall layers forming the spore wall (endosporium, middle layer, exosporium, ornamentation) and to different elements forming the ornamentation (exosporium, ornaments, sheath, hyphal wall, adjacent fungal cells, material of the host). During teliosporogenesis the outer layers are usually deposited first. At the beginning of the formation of the ornamentation the plasma membrane may be smooth or undulated carrying the developing ornaments on its tips or in its depressions. The ornamentation of some genera appears similar when seen by scanning electron microscopy, but can be the product of different developmental patterns (e.g., warts of species ofFarysia, Tilletia, andUstilago), however, warty and reticulate ornamentation can both be produced by similar developmental processes (shown, e.g., for species ofCintractia andTilletia). Typical structures of the mature teliospore wall and developmental patterns based on homologous similarities are described for the following groups of genera or species:Macalpinomyces, Melanopsichium, Sporisorium, andUstilago infecting members of the family Poaceae;Kuntzeomyces, Testicularia, andTrichocintractia; Anthracoidea, Cintractia, Heterotolyposporium piluliforme, andTolyposporium junci; Glomosporium, Sorosporium, andThecaphora; Conidiosporomyces, Erratomyces, Ingoldiomyces, Neovossia, Oberwinkleria, andTilletia; Entyloma, and genera of the Doassansia group;Liroa, Microbotryum, Sphacelotheca, Ustilago infecting dicotyledons, andZundeliomyces; Aurantiosporium, Fulvisporium, andUstilentyloma. Special characteristics of the teliospore wall were observed for the generaDermatosorus, Doassinga, Entorrhha, Farysia, Mycosyrinx, Rhamphospora, and some species ofTolyposporium.
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  • 33
    ISSN: 1860-1499
    Keywords: Solitary fibrous tumor of the pleura ; Mesenchymal cell ; Immunohistochemistry ; CD 34 ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract A solitary fibrous tumor of the pleura (SFTP) in a 37-year-old woman was reported as a rare pleural tumor based on morphological, immunohistochemical, and electron microscopic studies. The results showed that the tumor was composed of spindle-shaped cells forming fascicular and interlacing patterns with a mixture of mature collagen. The tumor cells coexpressed vimentin and CD34 and lacked cytokeratin reactivity. Ultrastructurally, there were abundant collagenous fibrillae surrounding spindle-shaped cells in which the junctional complex, basement membrane-like structure, and microvilli were not seen. From literature review and observation of the morphological features around the tumor, we consider that the tumor originated from the stromal cells subjacent to the mesothelium.
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  • 34
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    Medical molecular morphology 31 (1998), S. 151-155 
    ISSN: 1860-1499
    Keywords: Serous adenocarcinoma ; Peritoneal neoplasm ; Immunohistochemistry ; Ultrastructure ; Case report
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Two cases of serous surface carcinoma of the peritoneum (SSCP) are discussed. The first patient was a 48-year-old Japanese woman with abdominal pain and fullness. The second patient was a 66-year-old Japanese woman with abdominal fullness. In both patients, laparotomy revealed many tumor nodules on the peritoneal surface. However, the ovaries, the uterus, and other intraperitoneal organs were free from tumors. The serum levels of CA125 were excessively elevated. The tumor cells were arranged in a papillotubular pattern. Mitoses were frequent. Diastaseresistant PAS-positive, and hyaluronidase-resistant alcian blue-positive materials were observed. In immunohistochemistry, the tumor cells showed positive reactions for cytokeratin, EMA, CA125, and HBME-1, and, in contrast, negative reactions for CEA, thrombomodulin, vimentin, and HHF35. In analysis for Ber-EP4, all tumor cells of case 1 were negative, and a few tumor cells of case 2 were positive. Ultrastructurally, hobnail-shaped tumor cells rested on a continuous basal lamina. Each cell was attached to short desmosomes. Microvilli were slender, straight, and short, and some had core rootlets. Many primary lysosomes were aggregated in the basal portion of the cytoplasm. A few well-differentiated ciliated cells were present. These two cases were diagnosed as SSCP.
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  • 35
    ISSN: 1860-1499
    Keywords: Restitution ; Ultrastructure ; Cell migration ; Colon ; Saponin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The superficial colonic epithelia of rats were exposed to 1.0% saponin solution for 3 min and fixed at various periods thereafter. The repair or restitution process was observed by light as well as by transmission and scanning electron microscopy. The exposure of the luminal surface to saponin resulted in uniform and extensive damage to the superficial epithelial cells without affecting the cells in the crypts. At 3 min after saponin treatment, the damaged epithelial cells exfoliated from the mucosa and the basal lamina was exposed. Within 15 min, most of the exposed basal lamina was covered by squamous to low-cuboidal epithelial cells, probably migrating from the crypts. These epithelial cells extended large lamellipodia over the denuded basal lamina. After 15 min the damaged surface was completely covered with epithelial cells, which became columnar at 1 h. Tight junction protein ZO-1 became positive along the restituted epithelium. Proliferating-cell nuclear antigen (PCNA) staining showed that proliferation of epithelial cells occurred after the restitution. These results suggest that saponin treatment serves as a good model system to study colonic restitution, which is carried out by rapid migration from the remaining crypt cells, followed by cellular proliferation. Rapid formation of tight junctions spanning the damaged regions allows rapid restoration of the barrier function of the colonic epithelium.
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  • 36
    ISSN: 1860-1499
    Keywords: Pancreas ; Peripheral nerve ; Cancer ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Nerve invasion is one of the biological features of pancreatic cancer, and its mechanism remains to be determined. In this paper, we report on 37 pancreatic cancer specimens observed by immunohistochemical and electron microscopical techniques. The results showed that pancreatic cancer directly invaded and destroyed the perineurium. At the early stage of disease, the peripheral nerve and synaptic membrane were easily destroyed by cancer cells, and invasion and metastasis continuously advanced along the perineural space and central side of nerves. These results suggest that the soft tissue and nerve plexus on the dorsal region of the pancreas may contribute to the recurrence of pancreatic cancer after duodenopancreatectomy.
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  • 37
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    Medical molecular morphology 31 (1998), S. 185-192 
    ISSN: 1860-1499
    Keywords: Rat fetal heart ; Capillary angiogenesis M ; Myocardial cleft ; Fibroblast ; Desmosome-like structure ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract To determine the course of capillary angiogenesis in the rat fetal heart, transmission electron microscopy was used to examine the development of both capillaries and cardiomyocytes. In the 15-day-old embryo, the coronary vessels had spread into the superficial space. In the 16-day-old embryo, the coronary vessels began to enter the myocardium. In the 17-day-old embryo, the terminal vascular bed had developed and a marked increase in the population of myocytes was evident. In capillaries entering the myocardium, the outgrowth of endothelial cells into the myocardial cleft was evident. These clefts were formed by intercalated disk and desmosome-like structures. The fibroblasts were always found close to the capillaries or in contact with endothelial cells during the fetal stage to the first neonatal week. In the interstition period, the fibroblasts were not found close to the capillaries. These results are discussed in relation to the role of myocardial clefts and the role of fibroblasts in fetal capillary angiogenesis.
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  • 38
    ISSN: 1860-1499
    Keywords: Malignant myoepithelioma ; Oral palate ; Immunohistochemistry ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Malignant myoepithelioma arising in the palatal gland is extremely rare. The present study demonstrated ultrastructural and immunohistochemical features of malignant myoepithelioma transformed from long-standing benign myoepithelioma occurring in the palatal gland. Microscopically, the tumor mass was composed of plasmacytoid cells and epitheloid cells. The malignant feature was seen only at the area adjacent to the bone. Immunohistochemically, most of the cells were S-100 positive, whereas vimentin and keratin were only partially positive. Glial fibrillary acid protein (GFAP) was positive at the peripheral cells of the solid nests and epitheloid cells with myxoid stroma. Ultrastructurally, filament-rich cells, tonofilament-rich cells, and filament-poor cells were observed. At the area adjacent to the bone, the cells implying malignancy were filament-poor cells in which the luminal structures could be detected. From these findings, a scarcity of filaments in myoepitheliomatous components may imply a malignancy.
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  • 39
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    European archives of oto-rhino-laryngology and head & neck 226 (1980), S. 239-250 
    ISSN: 1434-4726
    Keywords: Enchondrale Schicht ; Labyrinthknochen ; Ultrastruktur ; Vergleichende Anatomie ; Endochondral layer ; Labyrinthine bone ; Ultrastructure ; Comparative anatomy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Summary The endochondral layer of labyrinthine bone of dog (Canis f. intermedius Woldrich) is examined by means of light and transmission electron microscopy. The osteocytes of the fine-fibred, alamellar “embryonic skein bone” (Meyer 1927) are surrounded by a fibre-less matrix. They correspond to osteocytes in long bones. Some of them are producing microfibrils according to formation of preosseous tissue which is called “intraosseous osteogenesis” (Knese 1970). Others are characterized by signs of micropetrosis or indicate osteocytic osteolysis. In the perivascular mesenchym of some vessels giant cells are visible which according to their ultrastructural characteristics are identified as osteoclasts. The occurrence of an embryonic type of bone in endochondral layer of otic capsule throughout life is discussed considering oxygenation via perivascular canalizition as well as biomechanical aspects.
    Notes: Zusammenfassung Unseres Wissens ist dies die erste transmissionselektronenmikroskopische Untersuchung des normalen Labyrinthknochens. Hier wird die enchondrale Schicht beim Hund (Canis f. intermedius Woldrich) betrachtet, da menschliche Felsenbeine sich aufgrund postmortaler Veränderungen nicht für ultrastrukturelle Studien eignen. Im „zeitlebens embryonalen Strähnenknochen“ (Meyer 1927) sieht man Zellen, die in einem fibrillenfreien, perizellulären Hof unterschiedlicher Ausdehnung liegen. Diese entsprechen den Osteozyten in anderen Knochen. Einige dieser Zellen bilden Mikrofibrillen und sind zu einer „intraossären Osteogenese“ (Knese 1970) fähig. Andere Zellen bieten das Bild einer osteozytären Osteolyse. Auch kommt eine Mikropetrosis in nicht kanalisierten, perivaskulären Regionen vor. Im perivaskulären Mesenchym erkennt man vereinzelt Riesenzellen, die aufgrund ihrer Ultrastruktur als Osteoklasten zu bezeichnen sind. Das lebenslange Vorkommen des embryonalen Strähnenknochens in der Labyrinthkapsel wird unter Berücksichtigung biomechanischer Gesichtspunkte diskutiert. Dabei wird auch auf die perivaskuläre Kanalisierung des Strähnenknochens eingegangen.
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  • 40
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    Neurosurgical review 3 (1980), S. 151-158 
    ISSN: 1437-2320
    Keywords: Diffuse hypertrophy of the cerebellum ; Dysplastic cerebellar gangliocytoma ; Epilepsy ; Granule cell hypertrophy ; Hamartoma of the cerebellum ; Lhermitte-Duclos disease ; Megalencephaly ; Ultrastructure ; Diffuse Hypertrophie des Kleinhirns ; Dysplastisches Kleinhirn-Gangliozytom ; Epilepsie ; Granuläre Zellhypertrophie ; Hamartom des Kleinhirns ; Lhermitte-Duclos'sche Krankheit ; Megalencephalie ; Ultrastruktur
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Es wird über zwei Fälle von Lhermitte-Duclos'scher Erkrankung bzw. diffuser Hypertrophie des Kleinhirns berichtet. Histopathologisch handelt es sich dabei um umschriebene Dysmorphien des Kleinhirns, die so charakteristisch sind, daß sie bei chirurgischer Exploration vom bloßen Auge erkannt werden können. Die vergröberten, hypertrophen Kleinhirnläppchen heben sich zudem durch eine unterschiedliche Färbung vom normalen Kleinhirn ab (Fig. 1). An Stelle der Körnerschicht gibt es dicht beieinanderliegende, dysplastische Ganglienzellen verschiedenen Typs (Fig. 3), die myelinisierte Axone (Fig. 7) in die dadurch stark myelinisierte Molekularschicht schicken. Die Purkinjezellschicht fehlt, die Marklamellen sind stark verschmälert. Die Läsion wird als Hamartom aufgefaßt; klinisch kann sie als Raumforderung der hinteren Schädelgrube in Erscheinung treten. Die Mehrzahl der Patienten mit diffuser Kleinhirnhypertrophie haben zusätzlich andere gehäuft vorkommende Läsionen wie Megalencephalie, Schädelund Skelettanomalien, benigne und maligne extracerebrale Tumoren u. a. m. Bei dem ersten Fall handelt es sich um einen 39jährigen Mann, der neben der diffusen Kleinhirnhypertrophie ein megalencephales Gehirn (2320 g) hatte, und an einem metastasierenden Coloncarcinom ad exitum gekommen ist. Im Alter von 34 Jahren ist eine 540 g schwere Struma entfernt worden. Die Ganglienzellnatur der dysplastischen Zellen der Körnerschicht ließ sich anhand des Nachweises von Synapsen (Fig. 6) und großen Nisslschollen (Fig. 5) elektronenmikroskopisch beweisen. Bei dem zweiten Fall handelt es sich um eine 74jährige Frau, deren Kleinhirnläsion — wie im ersten Fall — klinisch nicht in Erscheinung getreten ist. Die Aetiopathologie ist nicht bekannt. Die organoide Struktur der cerebellären Läsion, die häufige Vergesellschaftung mit Megalencephalie und anderen Mißbildungen, sowie das Vorkommen von familiären Fällen macht es wahrscheinlich, daß es sich dabei um eine Entwicklungsstörung handelt. Die Lhermitte-Duclos'sche Erkrankung ist selten. Meines Wissens sind zur Zeit insgesamt 42 Fälle bekannt geworden.
    Notes: Summary Two cases of Lhermitte-Duclos disease or diffuse hypertrophy of the cerebellum are presented. This brings the total number of such cases reported in the literature to 42. Pathologically the disease is characterized by a circumscribed cerebellar lesion consisting of thickening of the cortex with closely packed dysplastic ganglion cells in the granular layer and with large myelinated axons in the molecular layer. Purkinje cells are missing and the central white matter is greatly reduced. The first patient, a man 39 years of age, had, in association to the cerebellar lesion, a megalencephalic brain (2320 g). He had suffered from epilepsy since he was 24-years-old and died with metastasizing colon carcinoma. An electron microscopic study of the cerebellar lesion disclosed perikarya containing large amounts of rough endoplasmic reticulum, cell processes filled with coated and dense core vesicles. In addition, there were numerous enlarged myelinated axons in the molecular layer. The second patient, a woman 74 years of age, had a small area of diffuse hypertrophy of the left cerebellar hemisphere measuring one centimeter in diameter. Specific symptoms were very scant in the first case and absent in the second one indicating a very slow evolution — if any — of the disease process. The etiology and pathogenesis remain unknown. However, the organoid structure of the lesion, the frequent association of megalencephaly and other congenital abnormalities, and the occurrence of familiar cases would favor the disease being basically a developmental disorder.
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  • 41
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    Archives of gynecology and obstetrics 230 (1980), S. 123-135 
    ISSN: 1432-0711
    Keywords: Clip ; Bleier-Clip ; Tube ; Histologie ; Sterilisation ; Ultrastruktur ; Clip ; Bleier clip ; Fallopian tube ; Histology ; Sterilization ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Summary A bilateral salpingectomy was performed at the time of vaginal hysterectomy in a pregnant patient sterilized 20 months earlier by application of Bleier clips to the fallopian tubes. Clip application to the left tube had been incomplete. Undisturbed tissue (left tube) and clipped tissue (right tube) were examined and compared by light and scanning electron microscopy. The segment of tube fully grasped by the clip had a completely detached lining epithelium with coarse and flattened mucosa, a loose stroma, and disorganized muscular bundles. The left tubal mucosa was normal, whereas the right tube was stenosed at the site of clip placement, with rigid walls and a 0.175 mm luminal diameter. With progressively greater stenosis toward the clip site, mucosal destruction increased. Polypoidal mucosal folds were seen, as well as fibrous adhesions between mucosal folds. These observations indicate that tissue damage is extensive enough after clip application to require excision of the damaged segment of tube and microsurgical re-anastomosis for reversal of sterilization.
    Notes: Zusammenfassung Das Untersuchungsgut, über welches hier eingehend berichtet wird, stammt von einer 37jährigen Schwangeren (8. Woche), bei welcher 20 Monate zuvor eine Sterilisation mit Bleier-Clips versucht worden war. Es ergab sich eine Indikation zur Hysterektomie mit bilateraler Salpingektomie, was uns erlaubte, die gewebliche Reaktion einer Tube, an der ein Bleier-Clip korrekt saß, mit der an der kontralateralen Tube, über welche die Schwangerschaft eingetreten war, zu vergleichen. Die Präparate wurden rasterelektronenmikroskopisch und anschließend an identischen Stellen desselben Blocks lichtmikroskopisch untersucht („post-scanning histology“). In der voll gefaßten rechten Tube war das luminale Epithel streckenweise von der Unterlage abgehoben, das Faltenrelief der Mucosa distal und proximal der Clipmarke vergröbert oder abgeflacht, das subepitheliale Bindegewebe aufgelockert und die Bündel der Muscularis auseinandergedrängt. Die nur partiell mitgefaßte und daher noch ausreichend durchgängige linke Tube war zwar stenosiert, jedoch abgesehen von Schwangerschaftszeichen ohne markante Veränderung des Epithels. In der durch der korrekt sitzenden Clip verschlossenen rechten Tube verengte sich die Stenose der Clipmarke trichterförmig von proximal wie von distal, ein solider Epithelstrang war lichtmikroskopisch jedoch durchgehend nachzuweisen. Schleimhautmikropolypen und narbige Überbrückungen des Faltenreliefs in unmittelbarer Nachbarschaft des korrekt sitzenden Clips veranschaulichen, ebenso wie die narbigen Veränderungen der Tubenwand, daß eine funktionsfähige Wiederherstellung der Tubenkontinenz nach Entfernung eines zur temporären Sterilisierung applizierten Bleier-Clip kaum anders als durch eine mikrochirurgische Reanastomosierung nach Resektion der narbigen Stenose erwartet werden kann.
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  • 42
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    Archives of gynecology and obstetrics 230 (1980), S. 49-75 
    ISSN: 1432-0711
    Keywords: Ovarian Sertoli-Leydig cell tumors ; Ultrastructure ; Histogenesis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Ovarian Sertoli-Leydig cell tumors are rare, most of them being endocrinologically active and causing virilization. Their histogenesis and nomenclature are still under discussion. Six such tumors were identified in the Laboratory for Histopathology of the University Women's Hospital, Zürich. The clinical data as well as the macroscopic, microscopic and ultrastructural features of these tumors are analysed and discussed. In an attempt to clarify their histogenesis, the ultrastructural features of these tumors have been compared with those of two granulosa cell tumors as well as with those of a testis in a patient with testicular feminization. Our own results and a study of published data suggest that Sertoli-Leydig cell tumors arise from ovarian stroma. Because of their obvious morphological similarities to testicular structures they should be termed “gonadal stromal tumors of android type”.
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  • 43
    ISSN: 1432-1106
    Keywords: Ventromedial thalamic nucleus ; Cerebellar degenerating boutons ; Ultrastructure ; Cat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Terminal degeneration of cerebellar afferents in the ventral medial thalamic nucleus (VM) was studied in cats at the ultrastructural level after uni- or bilateral lesions in the brachium conjunctivum (BC). To achieve discrete lesions within the BC, a new very accurate stereotaxic technique was used. Numerous large terminals belonging to a population of so-called LR boutons were observed degenerating in the VM. The boutons displayed a wide variety of degenerative changes. Some revealed the features of the classical neurofilamentous type of degeneration. Others, although containing a slightly increased number of neurofilaments, featured much more prominently large numbers of coated vesicle shells and heavy accumulations of a flocculent electrondense material. Degeneration in a third group of boutons similar to some extent to the light type of degeneration was characterized by tight clumping of enormously swollen or distorted synaptic vesicles within a light matrix. At later stages, however, all these boutons were believed to become shrunken and electron-dense since intermediate stages between the light- and dark-appearing boutons were observed. The degenerating cerebellar boutons formed asymmetrical synaptic contacts. Groups of 3 or 4 boutons terminated upon dendrites of projection neurons synapsing more frequently on spines than on dendritic stems. The synaptic contacts between cerebellar boutons and the vesicle-containing dendrites of local circuit neurons were encountered as often if not more than the contacts on projection neuron dendrites. Triads consisting of cerebellar boutons and dendrites of both types of neurons were observed very regularly. This synaptic arrangement provides the anatomical basis for the modification of cerebellar input in the VM by interneurons.
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  • 44
    ISSN: 1432-2307
    Keywords: Cortisol ; Myocardium ; Ultrastructure ; Morphometry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Male Wistar rats were treated with high cortisol doses for 1 week. The dose administered daily was 15 mg per animal in group 1 (7 animals) and 30 mg in group 2 (7 animals). 7 rats served as control group. After cortisol treatment the body weights decreased due to skeletal muscle catabolism and the heart weights increased. Morphometric analysis of the left ventricular posterior papillary muscles gave evidence that the increased heart weights resulted from an increased number of mitochondria and an increased volume of the cytoplasm, whereas the myofibrillar mass was not affected. The surface area of inner mitochondrial membranes (+cristae mitochondriales) per myofibrillar unit volume increased from 15.7 μ2/μ3 to 21.3 μ2/μ3 in group 1 and 21.4 μ2/μ3 in group 2. Ultrastructural changes indicating myocardial cell damage were absent. Similar quantitative results have been reported to occur in the early phase of cardiac overload. For elucidating the hemodynamic effects of glucocorticoid a second experiment was performed: 7 Wistar rats were treated with cortisol in the same way as group 1, 7 others of the same body weight served as control. The systolic arterial pressure was significantly elevated in the cortisol group. Though myocardial tissue is known to be able to accumulate large quantities of glucocorticoids our results indicate that the application of high cortisol doses for a short time does not produce myocardial cell damage and does not suppress the myocardial adaption to the glucocorticoid-induced hypertension, i.e. hypertrophy. On the contrary, it seems to be possible that the adaption process is itself facilitated or accelerated by the presence of high cortisol concentrations in the heart. This thesis is supported by the considerably higher relative heart weights in the cortisol groups and is in agreement with observations reported by other authors.
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  • 45
    ISSN: 1432-2307
    Keywords: Parathyroid carcinoma ; Tumour progession ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A case of parathyroid carcinoma in a 74-year-old female patient was studied by light and electron microscopy. The malignancy of the parathyroid tumour was confirmed by local recurrence and infiltration of adjacent structures. The tumour was composed of uniform chief cells without mitoses. Ultrastructurally, the cells were characterized by tortuous plasma membranes, numerous secretion granules, an extensive rough endoplasmic reticulum and lack of lipid vacuoles, all indicating hyperactivity, but not malignancy. At death, the autopsy revealed local recurrence of tumour tissue, but no distant metastases. Both light and electron microscopy showed that considerable dedifferentiation of the tumour tissue had occurred. The tumour cells were now characterized by a marked nuclear pleomorphism and a coarse clumping of the chromatin. The presence of secretion granules alone suggested a parathyroid origin. Thus, at death there was unequivocal histological evidence of a carcinoma, whereas no such diagnosis could be made from the early biopsy. The clinical course alone indicated the malignant nature of the lesion.
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  • 46
    ISSN: 1432-2307
    Keywords: Pituitary adenoma ; Prolactin ; Ultrastructure ; Immunohistochemistry ; Morphometry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Fifteen cases of pituitary adenoma, 14 of which were associated with hyperprolactinemia, were studied by observation and granule morphometry of electron micrographs, immunohistochemistry and sequential observation of in vitro release with regard to hormone production, storage and secretion. Adenoma cells of 6 cases with marked elevation of plasma prolactin were sparsely granulated, showed characteristic ultrastrucures including the presence of small secretory granules, well developed Golgi and rough membranes, misplaced exocytosis, and positive or negative immunostaining for prolactin. These adenomas also showed vigorous release of the hormone into the circulation and/or culture medium. In vitro studies showed that negative immunostaining of adenoma cells did not preclude the production and secretion of the hormone. One densely granulated adenoma containing cells with numerous lactotroph type granules showed moderate release of prolactin into the circulation. In an acromegalic case associated with both high plasma growth hormone and prolactin, some cells were shown by immunohistochemistry to store both hormones. There were 4 adenomas which could not be shown to produce, store and secrete prolactin by any method available.
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  • 47
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    Virchows Archiv 387 (1980), S. 279-288 
    ISSN: 1432-2307
    Keywords: Pituitary ; Ultrastructure ; Hypophysectomy ; Regeneration
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Male Wistar rats were partially hypophysectomized and sacrificed at intervals of from 2 days to 1 year following the operation. The resected material was examined under the light microscope and the residual pituitary under the light and electron microscope. Neither regeneration nor an anatomical restoration of the adenohypophysis occurred even one year after partial hypophysectomy. An increased number of small chromophobe stem cells and juvenile chromophil cells were found in the residual pituitary. The amount of mitoses were not significantly increased. The ACTH, FSH and prolactin producing cells demonstrated electron microscopically distinct changes which were interpreted as signs of intensified activity. This can be seen as a “functional regeneration” to maintain vital pituitary function for the organism.
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  • 48
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    Virchows Archiv 387 (1980), S. 353-369 
    ISSN: 1432-2307
    Keywords: Granulosa cell tumors ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The ultrastructural features of three granulosa cell tumors are presented. The neoplastic non-luteinized granulosa cells are characterized at sub-microscopical level by severely indented nuclei with prominent nucleoli, sparse to moderately developed predominantly granular endoplasmic reticulum, scanty lipids and lysosomes, small mitochondria with lamellar cristae and abundant intracytoplasmic filamentous material. The luteinized cells display a strongly developed tubular agranular endoplasmic reticulum and mitochondria with tubular cristae. These findings are compared with those of previous reports and discussed in relation to the well-known hormonal activity of these tumors.
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  • 49
    ISSN: 1432-2307
    Keywords: Eosinophilic granuloma ; Frontal lobe ; Histiocytosis-X ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The clinical symptoms, pathological findings and surgical treatment of a case of primary frontal lobe eosinophilic granuloma are presented. Initially a frontal mass was detected that clinically seemed like a low-growth tumor. After operation, the histological, cytochemical and ultrastructural studies showed positive acid phosphatase, α-naftil-esterase, oil-red and PAS reactions of tumoral cells and the presence of rod-shaped bodies in proliferative histiocytes, all which confirmed the pathological diagnosis of eosinophilic granuloma. Other osseous or visceral histiocytosis-X signs were not observed. The patient remains asymptomatic after a postoperative follow-up of 2 years.
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  • 50
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    Virchows Archiv 389 (1980), S. 1-11 
    ISSN: 1432-2307
    Keywords: Soft tissue sarcoma ; Myofibroblasts ; Ultrastructure ; Host response
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A series of 129 soft tissue sarcomas was examined ultrastructurally to determine in which neoplasms and to what extent myofibroblasts could be demonstrated. Twenty cases of fibromatosis and fasciitis served as controls. Myofibroblasts were identified in all 30 cases of malignant fibrous histiocytoma and all 4 cases of well-differentiated sclerosing liposarcoma. Though most numerous in areas of desmoplasia, in no instance did myofibroblasts constitute the dominant cellular constituent of either neoplasm. Myofibroblasts were identified with lesser frequency and in smaller numbers in fibrosarcoma, synovial sarcoma, malignant hemangiopericytoma and neuroblastoma. None were observed in a wide assortment of diverse sarcomas in which desmoplasia was not a feature. In comparison each lesion judged by light microscopy to represent either fibromatosis or fasciitis was composed principally of myofibroblasts. The demonstration of abundant myofibroblasts within a soft tissue lesion which has been subjected to wide sampling strongly suggests a benign proliferative process as opposed to a malignant neoplasm. It is hypothesized that myofibroblasts observed within collagenized regions of soft tissue sarcomas may constitute an expression of host response to neoplasia.
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  • 51
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    Virchows Archiv 389 (1980), S. 27-41 
    ISSN: 1432-2307
    Keywords: Chondrosarcoma ; Clear-cell chondrosarcoma ; Glucosaminoglycans ; Histochemistry ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Two cases of clear-cell chondrosarcoma located in the upper end of the right femur of men aged 30 and 40 years are reported. The roentgenologic appearances suggested a chondroblastoma. Both patients are alive, one and four years after surgical removal of the tumor. Glucosaminoglycans were studied with cationic dyes at different pH, with and without pretreatment with testicular hyaluronidase, and with the Scott technique at the light-microscopic level. Ultrastructurally, the glucosaminoglycans were studied with the high iron diamine and dialyzed iron techniques and glycogen with the PATCH-method. Light-microscopically, the tumors were characterized by clear vacuolated cells with distinct cytoplasm boundaries and scattered multinucleated giant cells of osteoclast type. Histochemical studies at the light-microscopic level indicate the presence of chondroitin 4- and 6-sulphate but no keratosulphate. Ultrastructurally, the predominant clear-cells showed features characteristic for chondroblasts. The cytoplasm showed areas lacking organelles and containing a low-density, finely granular matrix. These areas are considered to correspond to the clear cytoplasmic vacuoles seen under the light microscope. Most of the organelles were seen in the perinuclear region. The irregular tumor cells formed delicate protruding cytoplasmic extensions, which delineated intercellular spaces appearing as vacuoles under the light microscope. The benign multinucleated giant cells had an ultrastructural appearance typical of osteoclasts. Histochemical analysis at the electron-microscopic level showed the presence of sulphated glucosaminoglycans in the intercellular matrix and in association with the cytoplasmic membrane. Glycogen and non-sulphated acid glucosaminoglycans were found within the cytoplasm of the clear-cells.
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  • 52
    ISSN: 1432-2307
    Keywords: Congenital Nephrotic Syndrome of Finnish type ; Histochemical ; Placentomegaly ; Trophoblast basement membrane alteration ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary We have studied the morphological aspects of a thirty-six week gestational age placenta in the Congenital Nephrotic Syndrome of Finnish type. The study, conducted with histological, histochemical, morphometric and ultrastructural methods, demonstrates the presence of primary disorders of placentation consisting of persistent embryonic villi, arrested ramification and chorionangiomatosis. The villous development is compatible with the first-second trimester of pregnancy. Vasculo-syncytial membranes are quantitatively increased. Histochemical findings document placental immaturity further: Perls' reaction was positive for the trophoblast basement membrane (this is normally not observed beyond the second trimester), Alcian Blue positivity at pH 1 was also evident and was observed in three month gestational age placentae and in controls. Periodic Acid Silver Methenamine and Thioaldehyde Fuchsin documented abnormal thickenings of the trophoblast basement membrane. Electron microscopic observation reveals that the trophoblast basement membrane is thickened. Osmiophilic bodies are distributed throughout the trophoblast basement membrane and also within the basement membrane like material. Abundant microfibrils are present in the villous stroma. Lamination of basement membrane like material is observed in a subendothelial position. On the basis of their findings and in conjunction with the data in the literature regarding biochemical alterations of renal glomerular basement membranes in Congenital Nephrotic Syndrome Finnish type, the Authors suggest that a primitive membranopathy forms the basis for this pathological condition.
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  • 53
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    Virchows Archiv 389 (1980), S. 59-77 
    ISSN: 1432-2307
    Keywords: Ethanol ; Myocardium ; Ultrastructure ; Morphometry ; Mitochondria
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Male Wistar rats were fed with ethanol for 33 weeks. Ethanol was administered in a liquid diet containing 33% of the calories as ethanol. In the control group ethanol was isocalorically replaced by glucose. Light and electron microscopic investigation of the hearts did not indicate significant structural abnormalities, in contrast to the results of some other groups. Nevertheless, morphometric analysis revealed considerable quantitative changes. The number of mitochondria was remarkably reduced and the volume of an average single mitochondrion nearly doubled, whereas the volume fractions of mitochondria and myofibrils were unaltered. The analysis of the mitochondrial subcompartments indicated a slight decrease of the surface area of inner mitochondrial membranes per unit volume of mitochondria and a slight increase of the volume fraction of the mitochondrial matrix space. Myocardial cell hypertrophy or atrophy were not observed. We believe that the mitochondrial changes are the expression of an impaired biogenesis of these organelles. The increased number of capillaries in the ethanol-fed group is possibly caused by functional ethanol effects which may be partly similar to effects of chronic hypoxia. Ethanol- or acetaldehyde-induced damage of heart mitochondria may play an important role in the pathogenesis of alcoholic cardiomyopathy.
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  • 54
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    Virchows Archiv 389 (1980), S. 103-117 
    ISSN: 1432-2307
    Keywords: Gonadal dysgenesis ; H-Y antigen ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The gonads of 4 phenotypically female individuals with XY chromosomal constitution and signs of virilisation were examined by light microscopy. Electron microscopic examination was also performed in two cases. Serological analysis of H-Y antigen titer yielded positive results. The matrix of the gonads is shown to be ovarian stroma, in which tubular and follicular structures are embedded. The epithelia of the follicles resemble granulosa cells of the ovary, the tubular epithelia are resemble Sertoli cells. Tubules and follicles both show extensive regressive changes. A varying number of Leyding cells/stroma lutein cells were found in each gonad. The different degree of development of testicular and ovarian structures in the dysgenetic gonads might be explained by a defect of the gonadal specific receptor for the H-Y antigen, this defect varying in time of occurrence, duration and severity.
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  • 55
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    Virchows Archiv 389 (1980), S. 287-305 
    ISSN: 1432-2307
    Keywords: Myeloproliferative disease ; Osteomyelofibrosis ; Bone marrow biopsy ; Blast crisis ; Ultrastructure ; Basophilic leukaemia
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The clinical and morphological findings are presented in two patients suffering from myelofibrosis and osteomyelosclerosis which terminated in an acute blastic crisis. Clinical follow-up data and light microscopy of the bone marrow however, revealed a chronic megakaryocytic-granulocytic myelosis (CMGM) with progression into myelofibrosis during the course of disease. In one patient the blastic transformation involved predominantly basophils, and in the other, neutrophils, with an accompanying abnormal proliferation of megakaryocytes in both cases. Electron microscopy of this cell population demonstrated remarkable atypicalities of the neutrophilic, basophilic and megakaryocytic cell lines. These abnormalities consisted of a nuclear-cytoplasmic asynchrony and a partial arrest of maturation, sometimes resulting in bizarre cell forms. Our investigations support the hypothesis of a mixed cellularity type of myelosis with a gradual and insiduous progression into osteomyelofibrosis/-sclerosis and a potential blastic crisis. In the evolution of blastic crisis all cell lines may be transformed, but with predominance of one population — basophils and neutrophils in our two cases — in addition to atypicalities of megakaryocytes.
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  • 56
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    Virchows Archiv 385 (1980), S. 283-291 
    ISSN: 1432-2307
    Keywords: Hodgkin's disease ; Myofibroblasts ; Ultrastructure ; Nodular sclerosis ; Host response
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Ten cases of nodular sclerosing Hodgkin's disease involving lymph nodes were studied by electron microscopy to determine the ultrastructural composition of the nodule-stromal interphase and the collagenized regions. In addition to a few lymphocytes, rare eosinophils and neutrophils, abundant filamentous and granular electron dense material, collagen fibers and myofibroblasts were observed in all instances. Since myofibroblasts possess contractile and synthetic properties, it is likely they contribute to the retraction and sclerosis which together represent one of the morphologic hallmarks of the disease. The dense fibrosis and contractile state of such tissue may constitute a beneficial host response to contain and limit local and vascular invasion by the neoplastic cellular population, thus contributing to the relative benignity of this form of Hodgkin's disease.
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  • 57
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    Anatomy and embryology 158 (1980), S. 167-178 
    ISSN: 1432-0568
    Keywords: Placenta (human) ; Villous stroma ; Intercellular junctions ; Endothelium ; Ultrastructure ; Freeze-fracturing
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Intercellular junctions within the villous stroma and the cytotrophoblastic layer of the human full term placenta were investigated using thin sectioning and freeze-fracturing. Numerous maculae adherentes (desmosomes) were found between the cytotrophoblast cells and the syncytiotrophoblast. This junction type was also seen connecting adjacent cytotrophoblast cells. Large gap junctions were frequently observed in contact areas of perikarya or at processes of adjacent fibroblasts. They often exhibited a peculiar pattern of their particles on the P-face of the membrane. Small rows of junctional particles were found on the P-faces of interconnected smooth muscle cells and gap junctions frequently bridged myoendothelial and interendothelial contact zones. The significance of the junctional complexes is discussed in relation to functional systems within the villous stroma of the human full term placenta.
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  • 58
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    Acta neuropathologica 49 (1980), S. 43-49 
    ISSN: 1432-0533
    Keywords: Rat ; Peripheral nerve ; Macrophage ; Ultrastructure ; Histochemistry ; Acid phosphatase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The cellular content of the endoneurium in peripheral nerves of normal adult rats was studied. Endoneurial cells with high light-microscopical activity of acid phosphatase were usually located close to blood vessels or near the perineurium. Cells with the ultrastructural appearance of macrophages showed the same distribution and accounted for 2–4% of the endoneurial cell nuclei profiles. These cells rapidly endocytosed carbon particles after endoneurial administration of colloidal carbon in vitro.
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  • 59
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    Acta neuropathologica 51 (1980), S. 65-70 
    ISSN: 1432-0533
    Keywords: Morphometry ; Glial cells ; Portocaval anastomosis ; Ultrastructure ; Corpus striatum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The ultrastructure of astrocytes and oligodendrocytes was investigated in rats 10 days, 30 days, and 10 weeks after portocaval anastomosis (PCA). Cell and nuclear sizes were measured by planimetry on randomly sampled cells magnified×24,000. The volume fractions of mitochondria, glia fibrils, and lipofuscin granules were measured in astrocytes by electronic image analysis. The mitochondrial profile area distribution and oligodendrocyte mitochondrial content were likewise estimated. All PCA animals had an increased astrocyte cell and cytoplasmic area, and after correction for cytoplasmic edema all groups had an enhanced mitochondrial fraction and mitochondrial number. The mitochondrial sizes were increased in all PCA groups. The mitochondrial profile area distribution curves did not suggest more than one group of mitochondria. All PCA groups had increased fractions of lipofuscin granules and glia fibrils. The oligodendrocytes had a slight fall in cell, nuclear, and cytoplasmic area after 30 days of shunting, and the mitochondrial fraction was diminished. After 10 weeks of PCA, all changes were reversed to normal values. It is concluded that the astrocytes are the active cells in the brain metabolism of ammonium. The oligodendrocytes seem to be dependent on neuronal integrity and do not contribute to the brain ammonium metabolism. The increase in astrocyte lipofuscin granules content may be explained by a beginning neuronal loss.
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  • 60
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    Acta neuropathologica 51 (1980), S. 113-117 
    ISSN: 1432-0533
    Keywords: Peroxisomes ; Catalase ; d-amino-acid oxidase ; Glial tumors ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Morphologically and cytochemically defined peroxisomes (microbodies) were demonstrated in a series of 11 human glial tumors. The cytochemical methods used were the diaminobenzidine method for catalase and a tetrazolium salt-phenozine methosulfate method ford-amino-acid oxidase. Ultrastructurally, the peroxisomes were found as single membrane limited organelles with a granular matrix. Marginal plates as well as continuities with the smooth endoplasmic reticulum could be demonstrated. Peroxisomes were found most abundantly in subependymal giant cell astrocytomas, to a lesser number in astrocytomas and least abundantly in glioblastomas.
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  • 61
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    Acta neuropathologica 52 (1980), S. 157-159 
    ISSN: 1432-0533
    Keywords: Neurons ; Thalamus ; Inclusions ; Ultrastructure ; Myotonic dystrophy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Intracytoplasmic cosinophilic inclusions were found by light microscopy in the thalamic neurons of 35 consecutive normal adult brains and in a case of myotonic dystrophy, but not in six newborn children, including one with myotonic dystrophy. Histochemical tests suggested a protein composition. Ultrastructurally, the inclusions were composed of stacks of parallel alternating dark and light rectilinear profiles not surrounded by a limiting membrane. Such inclusions are a virtually constant finding in the adult human thalamus and probably represent sites of neuronal protein storage.
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  • 62
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    Acta neuropathologica 49 (1980), S. 75-78 
    ISSN: 1432-0533
    Keywords: Lamellar bodies ; Rough endoplasmic reticulum ; Purkinje neurons ; Adenohypophysis ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Lamellar bodies are stacks of parallel cisternae of approximately regular spacing derived from ergastoplasm. Their occurrence was studied in various nervous and epithelial cells of different animal species in both normal and diseased subjects. This organelle appears to be, at least for some cell types, a normal cytoplasmic feature. The number of lamellar bodies increases in some pathologic conditions and when the cell metabolism is elevated.
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  • 63
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    Acta neuropathologica 50 (1980), S. 81-83 
    ISSN: 1432-0533
    Keywords: Cerebral neuroblastoma ; Desmoplastic variant ; Dense core vesicles ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A desmoplastic primary cerebral neuroblastoma originating in the frontal lobe of a boy who died at the age of 6 years contained dense core vesicles within the cytoplasm of neoplastic cells as evidence of neuronal differentiation. Sarcomatous transformation had occurred at the time of recurrence. At autopsy, he also had cerebrospinal and extraneural metastases.
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  • 64
    ISSN: 1432-0533
    Keywords: Skeletal muscle ; Senescence ; 65 to 89-year-old people ; Histopathology ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Biopsies for histochemical and ultrastructural studies were taken from the M. vastus lateralis of 45 healthy sedentary men and women aged 65–89 years. With increasing age the histochemical reactions reveal changes in the fibre type distribution characterized by a decrease in the percentage and predominant atrophy of type II fibres. The most frequent changes in the oldest subjects are: targetoid fibres, type I fibre predominance, and type grouping phenomena; expressions of denervation. Myopathic alterations are observed unusually. Electron microscopic findings are characterized by myofibrillar disorder, streaming of Z line and rod formation, and dilatation and increase of sarcoplasmic reticulum. As the age increases, the fibres become richer in intracellular lipid droplets and lysosomes. Intramuscular microcirculatory alterations, consisting of arteriolosclerotic changes and increase in width of the capillary basement membrane, are also observed and discussed.
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  • 65
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    Anatomy and embryology 160 (1980), S. 11-27 
    ISSN: 1432-0568
    Keywords: Sertoli cells ; Rat ; Fetal and postnatal life ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Sertoli cells have various functions: mechanical (creation of two compartments in the seminiferous tubules, migration of germinal cells), secretory (secretion of anti-Müllerian hormone, inhibin, androgen-binding-protein and estrogen) and phagocytic. We report an ultrastructural study of the rat Sertoli cell during maturation and consider possible correlations between the acquisition of certain morphological characteristics and certain functions. During fetal life, the Sertoli cell possesses differentiated zones of junction with the gonocytes and seems to have a role in the migration of the gonocytes towards the periphery of the seminiferous tubule. The Sertoli cell performs the phagocytosis of the gonocytes which degenerate during their migration, and seems to be the site of production of protein granules, whose presence can be related to the synthesis of anti-Müllerian hormone. After birth and before puberty, when the inclusions resembling secretory granules disappear, the Sertoli cell membranes in contact with spermatocytes II and spermatids differentiate, forming, through the differentiated junctional complexes, two compartments (adluminal and luminal) in the seminiferous tubules. Finally, they acquire the characteristics of active secretory cells, capable, in particular, of steroid synthesis.
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  • 66
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    Anatomy and embryology 160 (1980), S. 275-284 
    ISSN: 1432-0568
    Keywords: Adenohypophyseal rudiment ; Follicular cells ; Ultrastructure ; Culture
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The epithelial rudiment of 4 day-old quail embryo adenohypophysis, cultivated in vitro under conditions allowing glandular differentiation, displays peripheral cells that progressively acquire follicular cell features. They elongate, develop numerous microvilli, junctional complexes, interlocking membranes and bundles of microfilaments. These follicular-like cells derive from peripheral epithelial cells that, in situ, become glandular. These results show that follicular cells can develop from undifferentiated cells. They undergo this pathway of development, in all likelihood, as a result of perturbations in their microenvironment.
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  • 67
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    Anatomy and embryology 159 (1980), S. 277-288 
    ISSN: 1432-0568
    Keywords: Megakaryocyte ; Bone marrow ; Steel mice ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The megakaryocytes in the bone marrow of steel mutant mice (Sl/Sld) and their normal littermates (+/+) were studied by light and electron microscopy with special emphasis on their maturity and distribution in the hematopoietic cords. A higher percentage of megakaryocytes lying against the sinus wall, a higher percentage of the sinus perimeter covered by megakaryocytes and a higher percentage of large megakaryocytes were found in Sl/Sld mice than in +/+ mice. In addition, more large megakaryocytes as well as senile megakaryocytes were observed in the spleen of Sl/Sld mice than in that of +/+ mice. These observations suggest that more platelets are produced in Sl/Sld mice than in +/+ mice on the basis of per unit area of the marrow tissue. Heretofore, the fate of the senile megakaryocytes in the marrow was not known. However, in Sl/Sld mice senile megakaryocytes were often found entering the marrow sinuses from the hematopoietic cords. They were also seen in the lung and the spleen where degradation of senile megakaryocytes was observed. These observations suggest that senile megakaryocytes in Sl/Sld mice leave the marrow and are removed by the reticuloendothelial system outside the marrow.
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  • 68
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    Anatomy and embryology 159 (1980), S. 289-305 
    ISSN: 1432-0568
    Keywords: Placenta (rat) ; Development ; Intercellular junctions ; Ultrastructure ; Freeze-fracturing
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The differentiation of chorionic layers II and III and alterations of intercellular junctions within the developing placental labyrinth were investigated in rats. Between the 14th and 16th day of gestation, the trabecular structures of the labyrinth alter and increasing numbers of primary, secondary, and tertiary lamellae develop. Trophoblastic layer I remains multicellular. Layer III rearranges and cytoplasmic fusions result in a continuous cytoplasmic barrier intervening between the already syncytial trophoblastic layer II and fetal capillaries. Simultaneously, most of the “undifferentiated” cells within the labyrinth disappear. Thin sectioning anf freeze-fracturing reveal multiple images of intercellular junctions, particularly gap and tight junctions in the cellular and syncytial parts of layers II and III. Continuous and regularly arranged tight junctions occur as well as fragmented structures which are spaced irregularly. Gap junctions are occasionally found between the juxtasinusoidal regions of layers II and III on the 14th day. More often they occur within restricted areas near the center of the trabeculae, integrated within extensive tight junctional strands. Gap junctions increase in later stages of pregnancy and eventually become distributed between the interfaces of layers II and III in the primary lamellae.
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  • 69
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    Archives of dermatological research 267 (1980), S. 275-282 
    ISSN: 1432-069X
    Keywords: Allergic contact dermatitis ; Epidermal cell changes ; Ultrastructure ; Allergische Kontaktdermatitis ; epidermale Zellveränderungen ; Ultrastruktur
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Frühe epidermale Veränderungen bei allergischer Kontaktdermatitis wurden im Elektronenmikroskop untersucht. Gesunde freiwillige Testpersonen wurden mit DNCB sensibilisiert und in der Folge Kontaktreaktionen hervorgerufen. Epidermale Zellveränderungen nach 3 h waren unter anderem: Auftreten kleiner Vakuolen mit oder ohne Membran, stellenweise Erweiterung des Intercellularraums und eine Veränderung des Tonofilaments in kurze, gehäufte Bündel. Nicht sensibilisierte Haut, auf die DNCB appliziert wurde, zeigte auch kleine Vacuolen mit oder ohne Membran. Monocyten drangen in den Intercellularraum ein, der nicht ausgedehnt wurde. Die benachbarten Tonofilamente der Keratinocyten blieben normal.
    Notes: Summary Early epidermal lesions of allergic contact dermatitis were examined by electron microscopy. Normal human volunteers were sensitized to DNCB, and contact reactions were elicited sequentially. Epidermal cell changes at 3 h included: the occurrence of small vacuoles with or without membrane, focal dilatation of intercellular spaces, and the alteration of tonofilaments into short, aggregated bundles. Non-sensitized skin to which DNCB was applied also showed small vacuoles with or without membrane. Monocytes infiltrated into the intercellular spaces which were not dilated, and the neighboring tonofilaments of keratinocytes remained normal.
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    Archives of dermatological research 267 (1980), S. 283-290 
    ISSN: 1432-069X
    Keywords: Allergic contact dermatitis ; Infiltrating cells ; Monocytes ; Lymphocytes ; Ultrastructure ; Allergische Kontaktdermatitis ; Infiltratzellen ; Monocyten ; Lymphocyten ; Ultrastruktur
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Die Art und Feinstruktur mononuklearer Zellen, die bei allergischer Kontaktdermatitis nach ungefähr 6 h in der Epidermis auftreten, wurden im Elektronenmikroskop untersucht. Es handelte sich um Monocyten und Lymphocyten, die in ungefähr gleicher Zahl auftraten. Die Ultrastruktur der Monocyten war die gleiche wie die normaler Monocyten im Blut. Offenbar in aktiver Bewegung, erweitern sie die intercellulären Verbindungen der Keratinocyten. Die Lymphocyten zeigten einen runden oder ovalen Kern mit einigem elektronendichten Cytoplasma, das Ribosomen und Polysomen enthielt, aber nur fallweise Mitochondrien und Golgi-Komplexe.
    Notes: Summary The kind and fine structure of mononuclear cells appearing in the epidermis at about 6 h of allergic contact dermatitis were examined by electron microscopy. They were monocytes and lymphocytes, the number being about equal. The ultrastructure of monocytes was that described for normal ones in blood, and apparently actively moving, streching the intercellular connections of the keratinocytes. Lymphocytes displayed a round or oval nucleus with some electron-dense cytoplasm which contained ribosomes and polysomes but only occasional mitochondria and Golgi complexes.
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  • 71
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    Acta neuropathologica 49 (1980), S. 225-230 
    ISSN: 1432-0533
    Keywords: Human pituitary adenomas ; Tissue culture ; Cell culture ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Pituitary adenomas of 120 patients were investigated in tissue and in cell cultures. Under different conditions of culture, the biopsies revealed different rates of growth. In tissue cultures 66% of the samples could be propagated while tumour specimens explanted in cell suspensions proliferated in 80% of the cases. Attempts to establish subcultures were also more successful when specimens were put into cell cultures primarily. Further differences of growth characteristics were observed in connection with the histological types of the parent tissues. According to the old terminology cells of mixed type adenomas had the longest life-span both in tissue and in cell cultures. Considering the proliferative activity, this type of tumour could be most frequently subcultured. Concerning the relationship of different cell components of the biopsies it was proven that survival and proliferation of adenoma cells may occur without fibroblasts. The appearance of fibroblast-like cells in older cultures is a morphological manifestation of the senescence of the specific cell types. Qualitative features of cultured adenoma cells showed that on the basis of cytomorphological properties “chromophobe” samples could be separated from the other types. Cells of acidophil and mixed type growths had the capacity of developing in vitro various migratory shapes, while “chromophobe” cells did not possess this ability. The histological diagnoses made independently from cultures confirmed the tissue culture findings. Differences of in vitro characteristics correlated also with the ultrastructural features of the cultured adenoma cells.
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  • 72
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    Acta neuropathologica 51 (1980), S. 249-250 
    ISSN: 1432-0533
    Keywords: Neurons ; Mitochondria ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Ultrastructural study of the cerebral cortex and spinal anterior horns disclosed periodically repeating processes located in the envelope space or in the intracristal space of neuronal mitochondria. The alteration was observed in postmortem cases in which fixation was delayed either voluntarity or involuntarily, but was not present in postmortem or surgical specimens in which fixation was prompt. The change is interpreted as an artifact due to delayed fixation.
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  • 73
    ISSN: 1432-0533
    Keywords: Aging ; Hypertension ; Blood-brain barrier ; Ultrastructure ; Blood vessels
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary This study demonstrates that markedly different patterns of age-related changes in blood pressure and body weight occur among normotensive Wistar-Kyoto (WKY) and Sprague-Dawley (SD) rats and spontaneously hypertensive rats (SHR). In addition, a variety of age-related structural alterations occurred in the walls of arterioles, capillaries, and venules of the frontal cortex. These changes include: (1) an increase in the thickness of the vascular wall by deposits of collagen and basal lamina which, in some cases, extended into the surrounding neuropil; (2) the presence of a flocculent material in the adventitia of intracerebral arterioles; (3) vesicular inclusions in perivascular macrophages, pericytes and smooth muscle cells which were labelled with i.v. administered horseradish peroxidase (HRP); (4) fragmentation of smooth muscle cells; and (5) accumulation of lipofuscin-like pigments in perivascular glial processes. The hypertensive rats exhibited these changes, but they were more advanced and more widely distributed throughout the cerebral cortex. The aged hypertensive rats occasionally had large bundles of 10 nm diameter, intermediate filaments in the endothelial cells. Whereas no change in blood-brain barrier permeability to HRP was observed in the aged normotensive rats, all age groups of the hypertensive rats exhibited increased permeability to HRP in the initial segment of penetrating arterioles in laminae I and II of the cerebral cortex.
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  • 74
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    Development genes and evolution 188 (1980), S. 65-73 
    ISSN: 1432-041X
    Keywords: Nuclear migration ; Cleavage ; Microtubules ; Ultrastructure ; Gall midge
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary In the eggs ofWachtliella persicariae the cleavage nuclei move relative to the surrounding ooplasm. This ‘active’ migration is caused by an organelle whose ultrastructure was studied throughout the mitotic cycle. It consists of a greatly enlarged polar cytaster derived from the mitotic apparatus, linked to the nucleus by 100 Å filaments. The microtubules of the cytaster were found only during periods of active nuclear migration, i.e., from the onset of anaphase to the early prophase of the next mitotic cycle. They are always solitary and follow the course of the astral rays, which are known to temporarily adhere to peripheral structures of the egg cell and to exert tractive forces. In contrast to the cytaster microtubules, the microtubules in the spindle are bundled and persist from early metaphase through late telophase. During ontogenesis the first migration cytaster is built up between 3 and 12 min after oviposition near the anterior egg pole, in the vicinity of the sperm nucleus. In non-inseminated eggs time lapse films show a migration cytaster to develop autonomously in a region free from nuclei, but it does not follow the normal path of the male pronucleus. In several cases the female pronucleus, which remains without a cytaster of its own, was observed to move to the cytaster generated in the absence of the male pronucleus. Whether or not it is adhering to a nucleus, the cytaster divides into two at the correct time, i.e, corresponding to the first cleavage division in fertilized eggs. In some non-inseminated eggs this type of ‘pseudocleavage’ has been observed to occur repeatedly, giving rise to an increasing number of anucleate cytasters.
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  • 75
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    Development genes and evolution 188 (1980), S. 163-177 
    ISSN: 1432-041X
    Keywords: Yolk sac ; Ultrastructure ; Embryogenesis ; Drosophila
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Changes at the ultrastructural level during germ band extension in the embryo ofDrosophila melanogaster are described. Cytoplasmic connections between cells and the yolk sac are present during initial cellular movements. At this time, a continuous system of microfilaments is present adjacent to the membranes in the connections and at the periphery of the yolk sac. As germ band extension progresses, this system becomes discontinuous, and microfilaments are apparent only in the immediate vicinity of the connections. Cytoplasmic connections are disassembled at approximately the midpoint of extension; at the same time, extensive membrane associations develop between germ band cells and between these cells and adjacent yolk sac membranes. Positioning and orientation of cytoplasmic connections suggest that the yolk sac, via these connections, is actively involved in the cellular movements of early germ band extension.
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  • 76
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    Calcified tissue international 31 (1980), S. 93-108 
    ISSN: 1432-0827
    Keywords: Calculus ; Ultrastructure ; Apatite ; Transmission ; Scanning
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Using transmission and scanning electron microscopy, we have studied the ultrastructure of a number of urinary calculi, mainly composed of calcium phosphate. Three fundamental kinds of calcium phosphates were detected: nonstoichiometric carbonate apatite, nonhexagonal octacalcium phosphate, and calcium-magnesium whitlockite. The influence that the organic matter, substitutions in the phosphate lattice of CO3 and Mg, and apatitic stoichiometry have on the ultrastructure of the calcium phosphate calculi has been detailed. An originating apatitic unity named U2 is assumed to be the responsible for all the different structures of calcium apatites appearing in renal calculi. On the basis of our observations, a mechanism whereby apatites grow is postulated; magnesium functions as an inhibitor for the growing mechanism.
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  • 77
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    Calcified tissue international 30 (1980), S. 27-34 
    ISSN: 1432-0827
    Keywords: Ultrastructure ; Calcium ; Cartilage ; Vesicles
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary The potassium pyroantimonate technique was utilized for the selective subcellular localization of calcium in the mandibular condylar cartilage of 1-day-old rats. Electron dense calcium pyroantimonate precipitates were localized principally in mitochondria and at the cell membrane of the chondrocytes. In addition, small intracellular vesicles 0.1–0.2µm in diameter were observed in proximity to the cell membrane of chondrocytes of the mid-hypertrophic zone. The results suggest that these vesicles were being extruded from the cell into the extracellular matrix. Energy-dispersive analysis by X-rays confirmed that calcium is the principal cation of the electron-dense precipitates.
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  • 78
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    European journal of pediatrics 134 (1980), S. 69-74 
    ISSN: 1432-1076
    Keywords: Achondrogenesis type I ; Ultrastructure ; Chondrocytes ; Cytoplasmic inclusions
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The light- and electron-microscopic structure of articular and costal cartilage in a case of achondrogenesis type I has been described. The most characteristic ultrastructural change in the chondrocytes was conspicuous dilatation of the rough endoplasmatic reticulum (RER) which contained amorphous electronopaque material. This change in the RER was accompanied by marked hypertrophy of the Golgi apparatus; the matrix was basically unchanged.
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  • 79
    ISSN: 1432-0738
    Keywords: Ultrastructure ; Morphometry ; Ageing ; Pentachlorophenol ; Liver
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Altersabhängige Unterschiede im Reaktionsverhalten der Leber bei männlichen Wistarratten nach intraperitonealer Applikation von 30 mg technischem Pentachlorphenol (PCP) pro Kilogramm Körpergewicht über 15 Tage wurden feinstrukturell-morphometrisch ausgewertet. Neben einer altersabhängigen Erhöhung des relativen Lebergewichts und einer Abnahme des Körpergewichts konnten umfangreiche Alterationen an den Hepatocytenzellkernen und Zellorganellen festgestellt werden. Die Ergebnisse belegen, da β PCP neben Veränderungen an den Mitochondrien und Microbodies eine Proliferation der Membranen des glatten ER und eine Verminderung von Membranen des rauhen ER hervorruft.
    Notes: Abstract Age-dependent effects of technical pentachlorophenol (PCP) on male rat livers were investigated after a 15 day treatment with PCP, 30 mg/kg/d body weight. The liver tissues were investigated morphometrically at light and electron microscopical levels. Statistically significant alterations of nuclei and organelles of the hepatocytes were described.
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  • 80
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    Journal of molecular medicine 58 (1980), S. 501-510 
    ISSN: 1432-1440
    Keywords: Primärer Hyperparathyreoidismus, klinische und klinisch-chemische Befunde ; Akuter Hyperparathyreoidismus ; Ultrastruktur ; Hypercalciämie ; Parathormonspiegel ; Primary hyperparathyroidism, clinical and laboratory findings ; Acute hyperparathyroidism ; Ultrastructure ; Hypercalcemia ; Parathormone, blood level
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Summary In a series of 6 patients out of 47 cases with extrarenal hyperparathyroidism we investigated the clinical, laboratory and ultrastructural peculiarities of acute hyperparathyroidism. It was found that there are characteristic differences between both entities which, however, are fluid. Clinically more severe were neuromuscular psychiatric and mental signs. In the laboratory parameters PTH determined by radio-immunoassay and calcium were higher whereas hemoglobin was lower. The weights of the adenomas did not differ in both groups and this was also true for light microscopy findings. Electron microscopy revealed accelerated hormone extrusion and autodigestion of retrieved membrane material in the cases of acute hyperparathyroidism similar to characteristics of parathyroid cells stimulated by hypocalcemia in tissue culture.
    Notes: Zusammenfassung Bei 6 Kranken mit akutem Hyperparathyreoidismus werden klinische Befunde, Labordaten und Besonderheiten in der Ultrastruktur der Nebenschilddrüsen den Daten von 47 Kranken mit extrarenalen Hyperparathyreoidismus gegenübergestellt. Typische Unterschiede konnten aufgezeigt werden, die Übergänge sind aber fließend. Beim klinischen Verlauf waren neuromuskuläre Zeichen, psychiatrische und Störungen des Bewußtseins deutlicher in der ersten Gruppe. Beim Vergleich der Labordaten war radioimmunchemisches Parathormon höher in der akuten Gruppe und das Hämoglobin niedriger. Das Gewicht der Adenome und die lichtmikroskopischen Befunde waren nicht unterschiedlich in beiden Gruppen. Die elektronenmikroskopischen Studien des Adenomgewebes zeigten eine erhöhte Hormonausschüttung mit einer deutlichen Beschleunigung der Autodigestion von Membranmaterial. Diese Veränderungen entsprechen etwa denen, wie sie an Nebenschilddrüsengewebe in der Gewebekultur nach Stimulation durch Hypocalciämie gefunden werden.
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  • 81
    ISSN: 1432-072X
    Keywords: Mating tube ; Microtubule ; Tremella ; Ultrastructure ; Yeast
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Ultrastructure of the mating tube formed in yeast haplont of the heterobasidiomycete Tremella mesenterica was studied by electron microscopy. Cell wall of the mating tube emerged as evagination of the inner layers, rupturing outer layers of the mother cell wall. Comparison with budding cells suggested that the tube emergence place at bud scar and the process of tube emergence was the same as that of bud emergence. Electron transparent vesicles of 0.1 μm diameter were scattered in the cytoplasm of the mating tube. Nucleus-associated organelle was located at one side of the nuclear envelope which extended towards the mating tube. A few microtubules were detected in the mating tube, but their association with a nucleus was not clear. The cytoplasmic structure of the mating tube was discussed in comparison with that of hyphae of the filamentous fungi.
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  • 82
    ISSN: 1432-072X
    Keywords: Claviceps purpurea ; Ultrastructure ; Development ; Sclerotium ; Oleosomes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The development of sclerotia of Claviceps purpurea was investigated by light and electron microscopy. During the first days after infection sterigma and conidiospores are formed. The spores show a moderately developed vacuolar system, they are thick walled and contain about 20% lipid (related to the cell volume) embedded in glycogen. The sterigma are cylindrical unicellular hyphae with electron dense cytoplasm and isolated strongly contrasted lipid droplets. In maturing sclerotia the hyphae become septated with increasingly thick cell walls and a large lipid content. The lipid forms small droplets in young cells, while in the mature sclerotium it occurs in the form of very large drops, occupying the major part of the cell. Simultaneously the composition of the lipid is changed. The mature cells have several nuclei. They are partially connected by osmiophilic substances, forming a network of intercellular spaces.
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  • 83
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    Virchows Archiv 389 (1980), S. 307-324 
    ISSN: 1432-2307
    Keywords: Polycythemia vera ; Secondary polycythemia ; Histopathology ; Ultrastructure ; Cytogenetics ; Bone marrow biopsy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Clinical and morphological studies including light microscopy, electron microscopy and karyotyping of the bone marrow, were performed on a total of 164 patients with polycythemic conditions. A final diagnosis was obtained from clinical findings and histopathology of plastic embedded core biopsies of the bone marrow including sequential examinations. 51 patients revealed a secondary polycythemia whereas 113 displayed polycythemia vera (P. vera). In this last group 83 cases have persisting P. vera. 30 showed a transgression towards chronic myeloid leukemia with or without accompanying myelofibrosis — osteomyelosclerosis (so called chronic megakaryocytic-granulocytic myelosis — CMGM). The histopathology of the bone marrow in P. vera revealed consistent alterations which are useful in distinguishing this disorder from secondary polycythemia (SP) and CMGM: depletion of iron storage, increased neutrophilic granulopoiesis but no gross atypia in maturation, polymorphism of megakaryocytes with conspicuous giant forms and dilatation and increased branchings of venous sinusoids. Electron microscopic findings were in agreement and showed further abnormalities of cytological maturation in the erythrocytic and granulocytic lineage. Cytogenetic studies in 27 non-treated patients with P. vera revealed the Philadelphia chromosomes in 2 cases, whereas in SP only minor chromosomal anomalies have been encountered in a few patients. It is concluded that histopathology of trephine biopsies of the bone marrow is an invaluable aid to establish a correct diagnosis, differentiating P. vera from the other potentially polycythemic disorders and helping to detect a possible progression towards leukemia at an early stage. Cytogenetic investigations may show early structural and numerical abnormalities of the karyotype and possibly precede a presumptive transgression towards myeloid leukemia (CMGM). A simultaneously performed histological and chromosomal examination of bone marrow samples is therefore desirable in each case of a polycythemic condition.
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  • 84
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    Virchows Archiv 389 (1980), S. 325-341 
    ISSN: 1432-2307
    Keywords: Polycythemia vera ; Myeloid leukemia ; Histopathology ; Ultrastructure ; Cytogenetics ; Survival
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Of 113 Patients with polycythemia vera (P. vera) who had been followed for the last 8 years, 30 cases (27%) developed myeloid leukemia with fibrosis of the bone marrow. Core biopsies of the bone marrow including sequential examinations in several cases revealed neoplastic proliferation of neutrophil granulopoiesis and an atypical megakaryopoiesis with accompanying fibrosis of varying degrees. These alterations were consistent with a subtype of chronic myeloid leukemia — the so called chronic megakaryocytic-granulocytic myelosis (CMGM) — and correspond to (agnogenic) myeloid metaplasia with osteomyelofibrosis/-sclerosis. 5 of those 30 patients showed spontaneous transgression into myeloid leukemia, none of them had received any ionizing radiation or cytostatic therapy. A blast crisis or so called acute leukemia in P. vera was seen only in one patient who was treated by an overdose of radioactive phosphorus and later evolved into osteomyelosclerosis with blastic transformation. These findings of a chronic leukemia or CMGM arising from P. vera was further confirmed by atypia of ultrastructure and particularly by our cytogenetic evaluation. Chromosomal studies showed a Ph′-chromosome to be present in 5 of 8 patients with CMGM and myelofibrosis. Clinical and statistical evaluation of survival times showed a median survival expectation of all P. vera patients of 15 years. Life expectancy of the patients who still displayed P. vera was more favorable than those cases with transformation into CMGM, disregarding any therapy. Transformation of P. vera into CMGM occurred about 8 years after the onset of disease and following transgression into leukemia, half of these patients were dead after 2.5 years. Our results demonstrate that P. vera represents a “panmyelosis” with an inherent malignant nature, or a neoplastic proliferation of all three cell lines. This concept is supported by several facts: atypia of cytological differentiation as observed by light- and electron microscopy of the bone marrow, chromosomal anomalies with aneuploidy and an infrequent Ph'-marker, spontaneous transgression into chronic myeloid leukemia or its subtype CMGM without relevant therapy and a clonal evolution as shown by enzymatic studies reported in the literature.
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  • 85
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    Cell & tissue research 206 (1980), S. 95-114 
    ISSN: 1432-0878
    Keywords: Lateral eyes ; Scorpion ; Ultrastructure ; Retina ; Arhabdomeric cells
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The dioptric apparatus of the lateral eyes of the scorpion, Androctonus austrails, consists of a cuticular lens, but lacks a vitreous body. The retina is formed by (1) retinula cells displaying a contiguous network of rhabdoms; (2) arhabdomeric cells bearing a distal dendrite that contacts retinula cells via numerous projections and ends before the rhabdomere of the retinula cells; (3) pigment cells that ensheath retinula and arhabdomeric cells with the exception of the contact regions; and (4) neurosecretory fibres possibly originating in the supraesophageal ganglion. The ratio of the number of retinula to arhabdomeric cells is determined to be close to 2 ∶ 1 in the three larger anterolateral eyes, in contrast to the median eyes where the ratio is 5 ∶ 1. The construction of the dioptric apparatus as well as the anatomy of the retina imply that in the lateral eyes of Androctonus australis visual acuity is reduced. A certain degree of spatial discrimination, however, may be retained by the presence of a relatively high number of arhabdomeric cells. It is suggested that the lateral eyes of A. australis mainly function as light detectors, e.g., for Zeitgeber stimuli.
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  • 86
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    Cell & tissue research 206 (1980), S. 123-138 
    ISSN: 1432-0878
    Keywords: Ultrastructure ; Sense organs ; Compound eyes ; Interfacetal mechanoreceptor ; Coleoptera
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The structure of the compound eyes of adult Cicindela tranquebarica Herbst was examined by use of light, scanning, and transmission electron microscopy. Each ommatidium of these photopic eyes is eucone and has a “subcorneal layer” situated between the corneal lens and crystalline cone. A distal rhabdomere consisting only of microvilli from retinula cell seven, a more proximal, rectangular, fused rhabdom formed from six retinula cells, and a basal, eighth retinula cell with a spherical rhabdomere comprise the light sensitive portions of the ommatidium. The “subcorneal layer” consists of lamellae of endocuticular microfibrils and, in surface view, shows 11 concave polygons. Proximal extensions of the crystalline thread form inter-retinular fibres containing microtubules between retinula cells 1/2, 3/4, 5/6, and 7/1. The primary pigment cells are devoid of pigment granules, but are rich in rough endoplasmic reticulum. Proximal to each retinula cell nucleus are two basal bodies, one perpendicular to the other. The more proximal basal body extends two fibrillar feet proximally which fuse to form a horizontally-banded ciliary rootlet extending the length of the retinula peripheral to the rhabdom. Each ommatidium is surrounded by 16 secondary pigment cells. Interfacetal mechanoreceptors between some adjacent lenses each have a single bipolar neuron, with a dendritic sheath, tubular body, cilium, outer and inner sheath cells, and an axon surrounded by a neurilemma sheath cell.
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  • 87
    ISSN: 1432-0878
    Keywords: Somatostatin cells ; Calcitonin cells ; Ontogeny ; Ultrastructure ; Thyroid (rat)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Calcitonin cells are relatively numerous in the thyroid gland of the rat. In contrast, somatostatin cells are very scarce except at the time of birth and a few days thereafter, when they are conspicuously numerous. Somatostatin cells of the thyroid gland, which are ultrastructurally similar to somatostatin cells in gut and pancreas, also contain immunoreactive calcitonin. It is not clear whether somatostatin cells in the rat thyroid gland produce calcitonin or accumulate calcitonin from the environment.
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  • 88
    ISSN: 1432-0878
    Keywords: Preputial glands ; Nude mice ; Ultrastructure ; Gas chromatography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The preputial glands of male nude (nu/nu) mice were analyzed by a combination of electron microscopy and gas chromatography to determine whether or not they are affected, like developing hairs and nails, by the nu/nu genotype. Results of the analyses revealed no differences between the glands of nude and normal male mice in either their ultrastructural characteristics or lipid secretory products.
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  • 89
    ISSN: 1432-0878
    Keywords: Rat ; Preovulatory follicle ; Ultrastructure ; Degeneration ; Atresia
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary To identify and describe ovarian follicles committed to undergo follicular degeneration (atresia), immature rats were primed with pregnant mare serum gonadotropin (PMSG). After PMSG treatment, preovulatory follicles develop but subsequently degenerate. Prior to the appearance of pyknotic nuclei (Stage I of atresia), degenerative changes were observed in focal areas of the granulosa cell layer. These changes include “blebbing” of the cytoplasm and alterations in the shape of the granulosa cells. The appearance of these degenerative changes coincides with a decrease in ovarian concentrations of estradiol and testosterone. Since estrogens and androgens maintain the follicle, the decline in estradiol and testosterone could be responsible for the further degenerative alterations that lead to complete deterioration of the preovulatory follicle. In Stage I atretic follicles, lysosome-derived autophagic vacuoles develop and macrophages invade both the thecal and granulosa cell layers. The combined actions of the autophagic vacuoles and macrophages could destroy both the granulosa-cell and thecal layers and thereby transform the preovulatory follicle into an ovarian cyst.
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  • 90
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    Cell & tissue research 212 (1980), S. 241-255 
    ISSN: 1432-0878
    Keywords: Glomerulogenesis ; Glomerular capillaries ; Kidney development ; Corrosion casts ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Kidneys of 2 to 10 day-old rats of Wistar and Sprague-Dawley strains were fixed with glutaraldehyde by retrograde vascular perfusion and then prepared for observation in TEM and SEM. In addition methacrylate casts of differentiating glomerular capillaries were examined by SEM. Although the glomerular vascular pattern differs from one glomerulus to another, its differentiation proceeds according to the following general plan. First the glomerular capillary splits longitudinally, finally to form 3 to 5 lobules consisting of a capillary network, sustained centrally by the mesangium. In the present study the differentiation of glomerular capillaries is described in five successive arbitrarily selected stages. At Stage I a capillary loop penetrates between the lower limb and the middle segment of the S-shaped body, the rudimentary nephron. At Stage II the capillary undergoes a first subdivision, establishing the primitive lobulation of the glomerulus. At Stage III the vascular and urinary poles differentiate. At Stage IV the glomerulus assumes the aspect of a spherical body, and the capillaries in each lobule undergo subdivision. In Stage V the glomerular vascular pattern approaches its adult appearance, although the maturation processes continue for an extended period of time. Hence in the 10 day-old rat the best-differentiated glomeruli are half the size of adult glomeruli, and their capillary loops are proportionally less well-developed. The capillaries of adjacent lobules may communicate with each other, but a direct vascular shunt between the afferent and efferent vessels cannot be demonstrated.
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  • 91
    ISSN: 1432-0878
    Keywords: Stannius bodies ; Secretory cell types ; Teleosts (Fundulus, Carassius) ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The Stannius bodies of killifish and goldfish were ultrastructurally investigated after exposure of the fish to media of different osmolality and calcium content. In both species two structurally different secretory cell types are found. Type-1 cells predominate. They contain an extensive granular endoplasmic reticulum, some large Golgi areas, and secretory granules with a mean diameter of about 0.4 μm. These cells are activated by transfer of freshwater fish to seawater, but not by transfer to low-calcium seawater. Type-2 cells often contain cytoplasmic processes that penetrate between the type-1 cells and are ending on the basal lamina. In this contact area granule release takes place. Type-2 cells contain some strands of granular endoplasmic reticulum, several small Golgi areas, and secretory granules with a mean diameter between 0.15 and 0.20 μm. Type-2 cells are not activated after transfer of fish to seawater. In killifish seawater exposure leads to a reduction of type-2 cells. The differences between the reactions of both cell types to different media point to functional differences between their secretory products. Type-1 cells may produce a hypocalcemic factor. It is concluded that type-2 cells are typical for freshwater fish or euryhaline fish spending part of their life cycle in freshwater. The proper function of these cells is unclear.
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  • 92
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    Cell & tissue research 212 (1980), S. 307-314 
    ISSN: 1432-0878
    Keywords: Thymus (Mammalia) ; Erythropoiesis ; Macrocytes ; Anaemia ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The thymus of wild young and adult bank voles (Clethrionomys glareolus) was examined by histological methods for the presence of developing erythroid cells. Nucleated erythroid cells were observed in 26% of the glands examined by light microscopy and in 69% of the glands examined by electron microscopy. The largest number of developing erythroid cells was observed in the thymus of pregnant females, also showing raised reticulocyte counts (3.1–10.2%). However, erythropoiesis could also be found in breeding and non-breeding, first year and older animals. Erythroid cells were mainly located in the cortex, sometimes in small groups interspersed between lymphoid cells, and also randomly scattered in the cortex. Occasionally, macrocytic erythroid cells were also present. Pyknotic cells were commonly present, and granulopoiesis was frequently observed.
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  • 93
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    Cell & tissue research 208 (1980), S. 123-133 
    ISSN: 1432-0878
    Keywords: Lesioned axons ; Ultrastructure ; Crayfish
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The distal stumps of severed medial giant axons (MGAs) and of non-giant axons (NGAs) in the CNS of the crayfish Procambarus clarkii show long-term (5–9 months) survival associated with disorientation of mitochondria and thickening of the glial sheath. However, the morphological responses of the two axonal types differ in that neither the proximal nor the distal stump of severed MGAs ever fills with mitochondria as is observed in some severed NGAs. Furthermore, the adaxonal glial layer never completely encircles portions of MGA axoplasm as occurs in many severed NGAs; in fact, ultrastructural changes in the adaxonal layer around severed MGAs are often difficult to detect. No multiple axonal profiles are ever seen within the glial sheath of the proximal or distal stumps of severed MGAs whereas these structures are easily located within severed NGAs.
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  • 94
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    Cell & tissue research 211 (1980), S. 223-234 
    ISSN: 1432-0878
    Keywords: Neurosecretion, insect ; Median neurosecretory cells ; Melanogryllus desertus ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Based on the nature of their granules, eight principal types of neurons, six of which are thought to be neurosecretory, are recognized in the median neurosecretory cell group of the brain of Melanogryllus desertus. Most of the neurosecretory cells contain granules with diameters of 200–300 nm. In a few the granules are smaller with diameters varying from 60–100 nm. Most of the cells have well developed Golgi areas and dense bodies of different sizes. Dense bodies are closely associated with neurosecretory granules. Accumulations of electron-dense granular material occur in expanded cisterns of endoplasmic reticulum, particularly in type-I cells.
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  • 95
    ISSN: 1432-0878
    Keywords: Ultrastructure ; Fluorescence histochemistry ; Prevertebral ganglia ; Ageing ; 5-hydroxydopamine
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Sympathetic post-ganglionic neurones in the coeliac-superior mesenteric ganglion (CSMG) complex of aged (24 month) rats have been studied by glyoxylic acid-induced fluorescence and electron microscopy. Comparisons have been made with the CSMG of young adult (4 month) rats. In the aged rats the noradrenaline fluorescence of the majority of neuronal perikarya was very low or absent and few intraganglionic fluorescent varicosities were seen. Lipofuscin pigment was very prominent at the nuclear pole region of neurones and also in dendrites and axonal processes. Ultrastructural studies revealed large accumulations of residual bodies at the nuclear poles and in axons and dendritic profiles. Within the perikarya many mitochondria were distorted or swollen, the rough endoplasmic reticulum was disarranged and much dilated as were Golgi cisternae. Primary lysosomes were encountered throughout the neurone perikaryon and its axonal or dendritic processes. In contrast to the young adult CSMG, no evidence for loading of transmitter storage vesicles with an identical dose level of 5-hydroxydopamine was detected in any part of the neurones of aged rats. This might reflect an impairment of the uptake mechanisms and/or storage of noradrenaline in aged sympathetic neurones and their axonal and dendritic processes.
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  • 96
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    Cell & tissue research 205 (1980), S. 273-287 
    ISSN: 1432-0878
    Keywords: Human neurohypophysis ; Ultrastructure ; Pituicytes ; Ependyma ; Choristoma
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The pars nervosa of the neurohypophysis from 12 patients undergoing hypophysectomy for palliative treatment of advanced carcinoma was studied electron microscopically. Special attention was given to the cellular elements, the pituicytes. Five different classes of pituicytes, with various transitional forms, were elucidated based on their ultrastructural characteristics: (1) The most common type, referred to as “major pituicytes”, is reminiscent of astrocytes. (2) “Dark pituicytes” are thought to represent different functional stages of the “major pituicytes”. (3) “Ependymal pituicytes” are believed to provide ultrastructural evidence that human pituicytes are phylogenetically derived from ependymal cells. (4) “Oncocytic pituicytes” were observed in all cases and are of unknown significance. (5) The ultrastructural features of “granular pituicytes” suggest the existence of an active uptake and catabolism of extracellular material by pituicytes, probably through “ultraphagocytosis” or “endocytosis”. These five classes of pituicytes are considered to represent different functional forms of one cell line that originates phylogenetically from the ependyma.
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  • 97
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    Cell & tissue research 205 (1980), S. 361-370 
    ISSN: 1432-0878
    Keywords: Enamel organ ; Human foetus ; Tooth germ ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The fine structure of external enamel epithelium, stellate reticulum and stratum intermedium in primary tooth germs (bell stage) from four human foetuses was investigated. Characteristically, the cells of the differentiated external enamel epithelium, stellate reticulum and stratum intermedium exhibit many free ribosomes, few rough endoplasmic reticulum cisterns, well-developed Golgi complexes, many coated and smooth vesicles, often in relation to the cell membranes, and many bundles of tonofilaments. The cells are connected by numerous desmosomes and gap junctions. A parallel differentiation of stratum intermedium — external enamel epithelium, and the ameloblast layer is demonstrated. The morphology of the cells of the three layers indicates that these have secretory, transport and supporting functions.
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  • 98
    ISSN: 1432-0878
    Keywords: Trophamnion ; Coelenterate, Polypodium hydriforme ; Ultrastructure ; Planula ; Parasitism
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The larval stage of Polypodium hydriforme is planuliform and parasitic inside the growing oocytes of acipenserid fishes. The larva has inverted germ layers and a special envelope, the trophamnion, surrounding it within the host oocyte. The trophamnion is a giant unicellular provisory structure derived from the second polar body and performing both protective and digestive functions, clearly a result of adaptation to parasitism. The trophamnion displays microvilli on its inner surface, and irregular protrusions anchoring it to the yolk on its outer surface. Its cytoplasm contains long nuclear fragments, ribosomes, mitochondria, microtubules, microfilaments, prominent Golgi bodies, primary lysosomes, and secondary lysosomes with partially digested inclusions. The cells of the larva proper are poorly differentiated. No muscular, glandular, neural, interstitial, or nematocyst-forming cells have been found. The entodermal (outer layer) cells bear flagella and contain rough endoplasmic reticulum; the ectodermal (inner layer) cells lack cilia and contain an apical layer of acid mucopolysaccharid granules. The cells of both layers contain mitochondria, microtubules, and Golgi bodies; their nuclei display large nucleoli with nucleolonema-like structure, decondensed chromatin, and some perichromatin granules. At their apical rims, the ectodermal cells form septate junctions; laterally, the cells of both layers form simple contacts and occasional interdigitations. The lateral surfaces of entodermal cells are strengthened by microtubules.
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  • 99
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    Cell & tissue research 210 (1980), S. 257-267 
    ISSN: 1432-0878
    Keywords: Ultrastructure ; Smooth muscle ; Connective tissue ; Portal vein ; Rabbit
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The smooth muscle of rabbit portal vein was studied by electron microscopy with particular emphasis on the mechanical linkage between the muscle cells and on the distribution of connective tissue. The media of this vein is composed of inner circular and outer longitudinal muscle layers which are orientated almost perpendicularly to each other. The muscle of the inner circular layer shows very irregular contours with much branching and anastomosing of the cytoplasmic processes, which often make membrane contacts with neighbouring cells to form an extensive network of cytoplasmic processes. The muscle cells of the outer longitudinal layer are arranged in densely packed bundles and are spindle-shaped, with no branching processes. Opposing dense areas from neighbouring cells, with variable gap distances (30–100 nm) and close membrane contacts (intermediate junctions) with a gap of 11 nm were observed in both circular and longitudinal muscle layers. In the terminal regions of muscle cells in both circular and longitudinal layers a specialized anchoring structure was present which was closely related to extracellular elastic tissue. Muscle cells in the longitudinal layer showed the most elaborate structure, the tapering end of the muscle cell showing a honeycomb-like structure penetrated by columns of connective tissue compounds. The functional implications of these structures are discussed.
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  • 100
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    Cell & tissue research 210 (1980), S. 339-347 
    ISSN: 1432-0878
    Keywords: Seasonal breeding ; Leydig cells ; Ultrastructure ; Bat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Leydig cells of the bat, Myotis adversus, have been examined by electron microscopy throughout fourteen months. During the breeding season the Leydig cells become hypertrophied and are characterised by prominent areas of agranular endoplasmic reticulum and numerous small, membrane-bound granules. Microperoxisomes are also observed. During the period of testicular regression. Leydig cell size and the number of membrane-bound granules are greatly reduced. Lipid droplets and dense bodies are more numerous.
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