Library

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • 1990-1994  (11,015)
  • 1970-1974  (4,907)
  • Analytical Chemistry and Spectroscopy  (9,591)
  • Engineering General  (3,633)
  • Industrial Chemistry  (1,923)
  • Electron microscopy
Source
Material
Years
Year
Keywords
  • 1
    Electronic Resource
    Electronic Resource
    Widespread aluminium deposition in extracerebral organ systems of patients with dialysis-associated encephalopathy (1994)
    Springer
    Virchows Archiv 424 (1994), S. 105-112 
    Details
    ISSN: 1432-2307
    Keywords: Silver staining ; Aluminium ; Laser microprobe ; Electron microscopy ; Dialysis-associated encephalopathy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract We have described new silver-staining methods for the demonstration of lesions in senile dementia of the Alzheimer type. The same procedure was used to visualize characteristic aluminium (Al)-containing inclusions in choroid epithelium, glia and neurons of the central nervous system in dialysis-associated encephalopathy (DAE). Here we describe the patterns and degree of Al deposition in extracerebral tissues of 12 DAE autopsy cases. Light microscopy of silver-stained paraffin sections demonstrated autonomic ganglion cells filled with numerous intracytoplasmic black-stained fine granular inclusions, which were also seen in endocrine tissues (pituitary, parathyroid and adrenal) and in Leydig cells. Heart, liver cells and the testicular tubules were involved, but decalcified bones, haematopoetic elements, hyperplastic epithelium and one case of malignant epithelium lacked inclusions. Laser microprobe mass analysis revealed prominent Al-related mass signals within the en-bloc silver-stained inclusions which were seen at low intensity in adjacent non-stained structures. Electron microscopy demonstrated accumulations of small electron-dense granules intermingling with lipopigments.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00197400
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Sarcoma of the pulmonary artery: report of four cases with electron microscopic and immunohistochemical examinations, and review of the literature (1994)
    Springer
    Virchows Archiv 424 (1994), S. 217-224 
    Details
    ISSN: 1432-2307
    Keywords: Pulmonary artery ; Neoplasm ; Sarcoma ; Immunohistochemistry ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Herein we report the clinicopathological features of four cases of pulmonary artery sarcoma that appeared at our institution during a period of 30 years. The patients, 2 males and 2 females, were 50–62 years old. Tumour was found in the pulmonary trunk and right pulmonary artery in all cases, in the pulmonary valve and left pulmonary artery in three of the four cases, and in the right ventricular outflow tract in one case. There was direct extension or metastases to the lungs in two cases, the heart in one case, mediastinum or lymph nodes in two cases and the pleura in one case. Ultrastructural examination in one case revealed cells with features of smooth muscle cells and myofibroblasts. Immunohistochemical examination of three cases gave the following results: vimentin and smooth muscle specific actin was positive in all three cases, desmin in one case and cytokeratin in one case. No positivity was found for Factor VIII. This and other studies indicate that histologically most pulmonary artery sarcomas are leiomyosarcomas or “undifferentiated spindle cell sarcomas”. Immunohistochemical and ultrastructural examinations favour an origin from myofibroblasts, probably derived from multipotent (undifferentiated) cells in the wall of the vessel. Most lesions show extensive intrathoracic growth although they rarely metastasize outside the thoracic cavity. They have a poor prognosis although some cases are currently being diagnosed during life.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00193503
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Ultrastructural localization of tissue factor on monocyte-derived macrophages and macrophage foam cells associated with atherosclerotic lesions (1994)
    Springer
    Virchows Archiv 425 (1994), S. 49-54 
    Details
    ISSN: 1432-2307
    Keywords: Thromboplastin ; Atherosclerosis ; Electron microscopy ; Cell culture
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The expression of tissue factor (TF) antigen by circulating monocytes, cultured macrophages, and macrophages associated with atherosclerotic lesions was ultrastructurally analysed using immunogold labeling. A subpopulation of macrophages associated with the intimal surface overlying lesions had a significant TF expression. Macrophages and macrophage foam cells that projected from the intima into the arterial lumen also expressed a high level of TF (14-fold increase over control). In contrast, circulating monocytes and macrophages in culture did not express TF above background control levels. This TF expression by macrophages in vivo but not by macrophages cultured from either normal or hypercholesterolemic animals suggests that monocyte activation and macrophage transition, as measured by TF expression, is lesion-dependent and not stimulated solely by intimal attachment, surface migration, or hypercholesterolemia. These results further suggest that macrophages and foam cells associated with early lesions of atherosclerosis can initiate fibrin formation, which could contribute to lesion complications and transition to a fibromuscular stage.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00193948
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Uptake and phototoxic effects of aluminum-chlorophthalocyanine (AISPc) in hurnan bladder carcinoma cells (1994)
    Springer
    Urological research 22 (1994), S. 79-83 
    Details
    ISSN: 1434-0879
    Keywords: Phototoxicity ; Aluminum-chlorophtalocyanine ; Electron microscopy ; DAB staining
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract In vitro experiments were performed on human bladder carcinoma cells to evaluate the uptake of aluminum-chlorophthalocyanine (AlSPc) and the subcellular target of phototoxicity. In order to quantify the correlation of intracellular uptake and incubation time and to identify the primary subcellular target of phototoxicity, fluorescence and absorption measurements have been carried out as well as electron microscopic studies. Absorption and fluorescence measurements showed the largest value after 24 h of incubation time. Fluorescence microscopic studies suggested the sensitizer to be located in a brighter patch within cytoplasm. Electron microscopic studies using DAB (3,3′ diaminobenzidine) staining showed that the mitochondria are the primary target of phototoxic activity of AlSPc and that the majority of vacuoles of treated cells were originally mitochondria.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00310996
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Madin-Darby canine kidney cells are injured by exposure to oxalate and to calcium oxalate crystals (1994)
    Springer
    Urological research 22 (1994), S. 197-203 
    Details
    ISSN: 1434-0879
    Keywords: MDCK ; Calcium oxalate ; Oxalate ; Scanning ; Electron microscopy ; Trypan blue ; Adenine
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The reaction of Madin-Darby canine kidney cells (MDCK) to potassium oxalate (KOx), calcium oxalate monohydrate (COM) crystals, or a combination of the two was studied. The most noticeable effect of exposure of the cells to either KOx or COM crystals was loss of cells from the monolayer ranging from 20% to 30%, depending upon the particular treatment. Cellular enzyme values in the media were elevated significantly by 12h of exposure, although in specific instances, elevated levels occurred at earlier time periods. As regards the monolayer, trypan blue exclusion was decreased significantly, although amounting to only a 4–5% reduction. Specific tritiated release occurred at 4 and 12 h after exposure to KOx and at 12 h after exposure to crystals. Structurally, COM-cell interactions were complex and extensive endocytosis was noted. Cells were released from culture either as cellcrystal complexes or from the intercellular spaces after exocytosis. When treatment were combined the effects were only slightly additive, but the two treatments potentiated each other: all media enzyme levels (with one exception) were elevated at 2 h, tritiated adenine release was present at 4 h, and there was more extensive cell loss from the culture monolayer. These data suggest that both KOx and COM crystals damage MDCK cells when applied alone, and in concert they act synergistically.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00541892
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Neuronal vacuole formation in the rat posterior cingulate/retrosplenial cortex after treatment with the N-methyl-d-aspartate (NMDA) antagonist MK-801 (dizocilpine maleate) (1994)
    Springer
    Acta neuropathologica 88 (1994), S. 511-519 
    Details
    ISSN: 1432-0533
    Keywords: Vacuolization ; Neurotoxicity ; Neuropathology ; Electron microscopy ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Cytoplasmic vacuoles appear in neurons of the posterior cingulate/retrosplenial cortex (PC/RS) of rats after treatment with N-methyl-d-aspartate (NMDA) receptor antagonists. Prominent dilatation of mitochondria and endoplasmic reticulum has been described within 2 h; however, the ultrastructural features of vacuole formation are unknown. To investigate this, the present study examined the PC/RS cortex of male rats (age 60–70 days) at 15, 30, 45, 60, 90, and 120 min after subcutaneous treatment with 1 mg/kg of the noncompetitive NMDA antagonist MK-801 (dizocilpine maleate, 5-methyl-10, 11-dihydro-5H-dibenzo [a,d] cyclohepten-5,10-imine). Subtle mitochondrial dilatation was identified in a few neurons as early as 15 min postdose (MPD). By 30 MPD, dilatation was more pronounced in mitochondria and also involved the endoplasmic reticulum and perinuclear space. Ribosomal disaggregation and degranulation were also evident by 30 MPD. At all subsequent time points, dilatation of mitochondria and endoplasmic reticulum progressed in severity. Although the relative involvement of mitochondria and endoplasmic reticulum varied, glia were not involved. These ultrastructural data suggest that after treatment with MK-801, mitochondrial dilatation precedes involvement of endoplasmic reticulum in vacuolization of susceptible PC/RS cortical neurons. The early mitochondrial effects identified in this study suggest an initial metabolic insult that rapidly progresses to affect endoplasmic reticulum and ribosomes. This strengthens the relationship between the ability of certain NMDA antagonists to induce energy perturbations and neuronal vacuoles in the same region of the rat cerebral cortex.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00296487
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Cytoplasmic inclusions of astrocytic elements of glial tumors: special reference to round granulated body and eosinophilic hyaline droplets (1994)
    Springer
    Acta neuropathologica 88 (1994), S. 501-510 
    Details
    ISSN: 1432-0533
    Keywords: Key words Round granulated body ; Eosinophilic ; hyaline droplets ; Astrocytic tumors ; Immunohistochemistry ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Round granulated body (RGB) and eosinophilic hyaline droplets (EHDs) have been described as cytoplasmic inclusions of certain astrocytic tumors. In the previous literature, however, these inclusions have been described using various terms or regarded as nosologically the same entity. Light microscopically, RGB appeared as a round discrete body filled with fine uniform granules, while EHDs demonstrated a cluster of bright eosinophilic, round objects of various size. They could be clearly distinguished even by conventional histochemical staining such as the Masson trichrome stain and the phosphotungstic acid hematoxylin preparation. Both RGB and EHDs expressed positive immunoreactions for glial fibrillary acidic protein, several lysosomal markers, and some stress-response proteins. The ultrastructural appearances of these inclusions were distinct, however, one common feature was that they consisted of aggregations of numerous membrane-bound electron-dense bodies. Thus, both inclusions appear to be produced by neoplastic astrocytes and are possibly related to the lysosomal system. We examined the presence of RGB and EHDs in 138 astrocytic tumors. Both inclusions occurred most frequently in pleomorphic xanthoastrocytomas, followed by gangliogliomas and pilocytic astrocytomas. Subependymal giant cell astrocytomas exhibited only RGBs. RGBs and EHDs were not seen in any abundance in glioblastomas, gliosarcomas, fibrillary astrocytomas, protoplasmic astrocytomas, or oligo-astrocytomas. Some glioblastomas, however, showed only EHDs in small numbers. Several anaplastic astrocytomas were associated with a large number of RGBs and/or EHDs, and they revealed only rare mitosis despite marked cellular pleomorphism. Although RGB and EHDs have different morphological features, the presence of these inclusions in abundance may represent either a degenerative change, a long-standing lesion, or an indolent growth of the astrocytic tumors.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00296486
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Neomyogenesis in neonatally de-efferented and postnatally denervated rat muscle spindles (1994)
    Springer
    Acta neuropathologica 89 (1994), S. 85-95 
    Details
    ISSN: 1432-0533
    Keywords: Key words     Neonatal de-efferentation ; Sensory denervation ; Electron microscopy ; Intrafusal muscle fibre types ; Postnatal myogenesis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract      The ultrastructure of muscle spindles de-efferented by the extirpation of the lumbosacral spinal cord at the age of 2 days and subsequently deprived of their sensory innervation by the section of the sciatic nerve at 3–4 weeks of age was studied in serial sections of 2-month-old rat hindlimb muscles. De-efferentation leaves the primary sensory neurons and their peripheral axons intact and capable of inducing the muscle spindle morphogenesis during the critical period of their development. In de-efferented and subsequently denervated muscle spindles, new supernumerary intrafusal muscle profiles (SIPs) appeared in the muscle spindle A region. They were formed in intimate spatial relation with the original intrafusal muscle fibres (IMFs) predominantly from activated satellite cells derived from both nuclear bag (larger diameter) and nuclear chain fibres. SIPs, however, lacked the typical nuclear accumulations, as well as other ultrastructural distinctions present in control IMFs. The majority of differentiated SIPs separated from original IMFs, whereas the less differentiated SIPs were usually closely apposed to the surface of the parent IMFs and both were covered by the common basal lamina. In some spindles, the original IMFs and/or new SIPs at different stages of their differentiation were found together and they formed clusters of variable shape and composition. In the majority of clusters, all profiles seemed to be isolated along their entire length, although in few clusters, occasional cytoplasmic connections of variable length between intrafusal profiles were found. This result is important for the interpretation of the forthcoming study of expression of muscle spindle-specific myosin heavy chain isoforms in denervated SIPs in rat muscle spindles gradually deprived of their motor and sensory innervation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004010050219
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Ontogeny of the endocrine cells of the stomach of sea bass (Dicentrarchus labrax L.): an ultrastructural study (1994)
    Springer
    Anatomy and embryology 190 (1994), S. 507-514 
    Details
    ISSN: 1432-0568
    Keywords: Endocrine cells ; Gut ; Ontogeny ; Electron microscopy ; Dicentrarchus labrax (Teleostei)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The endocrine cells present in the developing stomach of sea bass larvae have been characterized ultrastructurally. Only one endocrine cell type (type I) was found in the presumptive stomach of 9- and 12-day-old larvae, one (type II) and five (types III, IV, V, VI and VII) in the aglandular stomach of 32-, and of 39- to 46-day-old larvae, respectively, and five (types III, VIII, IX, X and XI) in the differentiated stomach of 55- and 60-day-old larvae. A maturation process was established for some of these cells. Types I, II and III and types IV and X were thought to be different maturational stages of the same endocrine cell type.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00235499
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Ontogeny of the endocrine cells of the intestine and rectum of sea bass (Dicentrarchus labrax L.): an ultrastructural study (1994)
    Springer
    Anatomy and embryology 190 (1994), S. 529-539 
    Details
    ISSN: 1432-0568
    Keywords: Endocrine cells ; Gut ; Ontogeny ; Electron microscopy ; Dicentrarchus labrax (Teleostei)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Several endocrine cell types were ultrastructurally characterized during the differentiation of the intestine and rectum of sea bass (Dicentrarchus labrax L.) larvae. Only one cell type (type I) was found in the posterior region of the undifferentiated gut of 5-day-old larvae (phase I). Types V and VI were found in both the intestine and rectum, types II, III and IV in the intestine, and types VII and VIII in the rectum of 9- and 12-day-old larvae (phase II), the rectum alone showing signs of functional differentiation. In phase III larvae, in which both the intestine and rectum were differentiated, types IX, X, XI, XII, XIII, XIV and XV were found in the intestine, only types X, XI and XII being seen in the rectum. Besides these, a new cell type, XVI, was observed in the intestine of 55- and 60-day-old larvae (phase IV), in which the digestive tract was completely differentiated. The endocrine cells appearing in phases I and II showed very scarce secretory granules and the ultrastructural features of undifferentiated cells. Some endocrine cell types in the earliest developmental stages were related to some of those found later. A maturational process of the endocrine cell types paralleled the differentiation of the intestine and rectum, with an apparent increase in the number of secretory granules accompanying organelle development.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00190103
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 11
    Electronic Resource
    Electronic Resource
    Immunocytochemical and ultrastructural studies of the motor cortex in amyotrophic lateral sclerosis (1994)
    Springer
    Acta neuropathologica 87 (1994), S. 578-585 
    Details
    ISSN: 1432-0533
    Keywords: Amyotrophic lateral sclerosis ; Motor cortex ; Betz cells ; Immunocytochemistry ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract This report concerns an immunocytochemical and ultrastructural study of the motor cortices of 11 patients with amyotrophic lateral sclerosis (ALS). Specimens from 12 normal individuals served as controls. Antibodies against phosphorylated neurofilament (PNF; 200 kDa), ubiquitin, glial fibrillary acidic protein (GFAP) and phosphorylated tau protein were used. The pyramidal cells of layer III of all ALS patients were stained, with varying intensities, by the antibody to PNF. By contrast, Betz cells reacted less frequently with this antibody. Staining for GFAP was noted in numerous astrocytes in layer III and at the transition between white matter and motor cortex of most patients. Ubiquitin-positive inclusions were only occasionally seen in Betz cell and pyramidal cell of layer V. These observations indicate that alterations of the motor cortex occur first in the pyramidal cells of layer III rather than in Betz cells. Pyramidal cells and Betz cells were not stained by the antibody to phosphorylated tau protein. In controls, pyramidal cells and Betz cells were less frequently stained with the anti-neurofilament antibody than those from ALS patients. Immunoreactivity of GFAP in layer III and at the junction of white matter and motor cortex was observed in only one patient. Ultrastructural examination revealed that the Betz cells of some ALS patients had Bunina bodies (BB), Lewy body-like inclusions (LBI) and skein-like inclusions (SI), as well as bundles of filaments that were thicker than neurofilaments; some of these filaments appeared to be constricted. The incidence of these inclusions was lower than that seen in anterior horn neurons. Cytoplasmic inclusions such as BB, LBI, and SI were not observed in any of the controls. Our findings suggest that the cytopathology of upper motor neurons is similar to that of lower motor neurons and that the changes seen in Betz cells appear to be a reflection of the lower motor neuron alterations.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00293318
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 12
    Electronic Resource
    Electronic Resource
    Astrocytic straight tubules in the brain of a patient with Pick's disease (1994)
    Springer
    Acta neuropathologica 88 (1994), S. 587-591 
    Details
    ISSN: 1432-0533
    Keywords: Astrocytes ; Electron microscopy ; Immunocytochemistry ; Pick's disease ; Straight tubules
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract This report concerns an immunohistochemical and ultrastructural study of cerebral astrocytes in a patient with Pick's disease of 20 years' duration. The autopsied brain was prominently small (710 g) with marked fronto-temporal lobar atrophy. Histological examination demonstrated profound neuronal loss and spongy changes with tau-positive Pick bodies in the frontal and temporal cortex. In addition, many glial cells in the temporal lobe white matter contained round to oval, argentophilic and slightly hematoxinophilic cytoplasmic inclusions that were also immunolabeled with the anti-tau antibody. On electron microscopy, the glial inclusions were observed in the perikarya of astrocytes that were recognized as such from intracytoplasmic glial filaments and the presence of gap junctions. The inclusions were free in the cytoplasm, without a limiting membrane, and mainly comprised irregular aggregations of bundles of about 15-nm straight tubules, which were indistinguishable from those of intraneuronal Pick bodies. Furthermore, various patterns of accumulation of the same straight tubules were frequently noted in perivascular astrocytic processes carrying a basal lamina. These findings indicate that in Pick's disease astrocytes are also affected by a similar insult to that which affects neurons.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00296498
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 13
    Electronic Resource
    Electronic Resource
    Neuronal vacuole formation in the rat posterior cingulate/retrosplenial cortex after treatment with the N -methyl-D-aspartate (NMDA) antagonist MK-801 (dizocilpine maleate) (1994)
    Springer
    Acta neuropathologica 88 (1994), S. 511-519 
    Details
    ISSN: 1432-0533
    Keywords: Key words Vacuolization ; Neurotoxicity ; Neuropathology ; Electron microscopy ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Cytoplasmic vacuoles appear in neurons of the posterior cingulate/retrosplenial cortex (PC/RS) of rats after treatment with N-methyl-D-aspartate (NMDA) receptor antagonists. Prominent dilatation of mitochondria and endoplasmic reticulum has been described within 2 h; however, the ultrastructural features of vacuole formation are unknown. To investigate this, the present study examined the PC/RS cortex of male rats (age 60 – 70 days) at 15, 30, 45, 60, 90, and 120 min after subcutaneous treatment with 1 mg/kg of the noncompetitive NMDA antagonist MK-801 (dizocilpine maleate, 5-methyl-10, 11-dihydro-5H-dibenzo [a,d] cyclohepten-5,10-imine). Subtle mitochondrial dilatation was identified in a few neurons as early as 15 min postdose (MPD). By 30 MPD, dilatation was more pronounced in mitochondria and also involved the endoplasmic reticulum and perinuclear space. Ribosomal disaggregation and degranulation were also evident by 30 MPD. At all subsequent time points, dilatation of mitochondria and endoplasmic reticulum progressed in severity. Although the relative involvement of mitochondria and endoplasmic reticulum varied, glia were not involved. These ultrastructural data suggest that after treatment with MK-801, mitochondrial dilatation precedes involvement of endoplasmic reticulum in vacuolization of susceptible PC/RS cortical neurons. The early mitochondrial effects identified in this study suggest an initial metabolic insult that rapidly progresses to affect endoplasmic reticulum and ribosomes. This strengthens the relationship between the ability of certain NMDA antagonists to induce energy perturbations and neuronal vacuoles in the same region of the rat cerebral cortex.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00296487
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 14
    Electronic Resource
    Electronic Resource
    An ultrastructural analysis of human post-infectious (allergic) encephalomyelitis (1994)
    Springer
    Acta neuropathologica 87 (1994), S. 541-544 
    Details
    ISSN: 1432-0533
    Keywords: Allergic Encephalomyelitis ; Astrocytes ; Demyelination ; Electron microscopy ; Multiple sclerosis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract A 6-year-old boy developed post-infectious encephalomyelitis and underwent a brain biopsy (10 days after the onset of neurologic symptoms). Electron microscopic analysis of brain showed demyelinated axons, thinly myelinated axons, aberrant remyelination, and numerous phagocytes containing myelin debris. Physical stripping of myeling by pseudopodial extensions of macrophages, as reported in experimental allergic encephalomyelitis, was noted. Hypertrophic and hyperplastic astrocytes were prominent among the phagocytic cells and played an unexpectedly active role in demyelination.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00294183
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 15
    Electronic Resource
    Electronic Resource
    Immunocytochemical and ultrastructural studies of the motor cortex in amyotrophic lateral sclerosis (1994)
    Springer
    Acta neuropathologica 87 (1994), S. 578-585 
    Details
    ISSN: 1432-0533
    Keywords: KeyWordsAmyotrophic lateral sclerosis ; Motor cortex Betz cells ; Immunocytochemistry ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract This report concerns an immunocytochemical and ultrastructural study of the motor cortices of 11 patients with amyotrophic lateral sclerosis (ALS). Specimens from 12 normal individuals served as con- trols. Antibodies against phosphorylated neurofilament (PNF; 200 kDa), ubiquitin, glial fibrillary acidic protein (GFAP) and phosphorylated tau protein were used. The pyramidal cells of layer III of all ALS patients were stained, with varying intensities, by the antibody to PNF. By contrast, Betz cells reacted less frequently with this antibody. Staining for GFAP was noted in numerous astrocytes in layer III and at the transition between white matter and motor cortex of most patients. Ubiquitin-positive inclusions were only occasionally seen in Betz cell and pyramidal cell of layer V. These observations indicate that alterations of the motor cortex occur first in the pyramidal cells of layer III rather than in Betz cells. Pyramidal cells and Betz cells were not stained by the antibody to phosphorylated tau protein. In controls, pyramidal cells and Betz cells were less frequently stained with the anti-neurofilament antibody than those from ALS patients. Immunoreactivity of GFAP in layer III and at the junction of white matter and motor cortex was observed in only one patient. Ultrastructural examination revealed that the Betz cells of some ALS patients had Bunina bodies (BB), Lewy body-like inclusions (LBI) and skein-like inclusions (SI), as well as bundles of filaments that were thicker than neurofilaments; some of these filaments appeared to be constricted. The incidence of these inclusions was lower than that seen in anterior horn neurons. Cytoplasmic inclusions such as BB, LBI, and SI were not observed in any of the controls. Our findings suggest that the cytopathology of upper motor neurons is similar to that of lower motor neurons and that the changes seen in Betz cells appear to be a reflection of the lower motor neuron alterations.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00293318
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 16
    Electronic Resource
    Electronic Resource
    Generalised nuclear and cytoplasmic inclusion disease: a rare case investigated by microscopy and immunohistochemistry (1994)
    Springer
    Acta neuropathologica 87 (1994), S. 648-654 
    Details
    ISSN: 1432-0533
    Keywords: Inclusion body disease ; Electron microscopy ; Immunohistochemistry ; Viral infection ; Primary metabolic disorder
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract A Caucasian female who was noted to be mildly microcephalic at birth was diagnosed as having cerebral palsy at the age of 1 year. Her development was delayed and she never walked or talked. She appeared relatively stable neurologically until the age of 17 years when she had an illness with fever thought to be due to a virus. She was noted to deteriorate from this time on until her death at the age of 19 years. Autopsy revealed intranuclear and cytoplasmic inclusions widespread throughout the brain and visceral organs. There was no evidence of inflammation. Immunohistochemistry revealed strong immunoreactivity for tau protein and neurofilament protein. Electron microscopy revealed the inclusions to be composed of homogeneous finely granular material. Scattered with the granular material in the cytoplasmic bodies were crystalline structures with a honeycomb appearance. The possibility of these changes representing an old viral infection or a primary metabolic disorder are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00293327
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 17
    Electronic Resource
    Electronic Resource
    Light and electron microscopic study of omental milky spots in New Zealand Black mice, with special reference to the extramedullary hematopoiesis (1994)
    Springer
    Anatomy and embryology 189 (1994), S. 215-226 
    Details
    ISSN: 1432-0568
    Keywords: Omental milky spot ; Megakaryocyte ; Myelopoiesis ; Electron microscopy ; New Zealand Black mouse
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Omental milky spots are especially large and numerous in New Zealand Black (NZB) mice, which are known to develop spontaneous autoimmune diseases. We investigated omental milky spots in NZB mice by light and electron microscopy. The milky spots were composed of abundant lymphocytes/plasma cells with macrophages, neutrophils, eosinophils, megakaryocytes, and various stromal cells. In addition, clustered neutrophils in various maturation stages with occasional mitotic figures were frequently present in the milky spots: apparent neutrophilic myelopoiesis was present. The presence of megakaryocytes was sporadic. Considering the giant size of megakaryocytes, their direct migration into the milky spots from the bone marrow or spleen seems improbable. Thus, the presence of megakaryocytes was interpreted as probable megakaryopoiesis. Erythroblasts were not contained in the milky spots. These findings seem to indicate that the milky spots in NZB mice represent a special type of lymphoid tissue with active neutrophilic myelopoiesis and probable megakaryopoiesis. Reticulum cells in the milky spots in NZB mice had well-developed dense bodies consisting of clustered parallel tubules that showed a hexagonal array. However, the biological significance of these cells remains unknown.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00239009
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 18
    Electronic Resource
    Electronic Resource
    Fiber composition of the lateral plantar and superficial peroneal nerves in the rat foot (1994)
    Springer
    Anatomy and embryology 189 (1994), S. 393-399 
    Details
    ISSN: 1432-0568
    Keywords: Rat ; Myelinated axons ; C-fibers ; Skin ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract This study examines the fiber composition of two nerves projecting to the rat hindpaw: the lateral plantar nerve (LPN), which innervates plantar glabrous skin and some plantar muscles, and the foot branch of the superficial peroneal nerve (fSPN), which projects to dorsal hairy skin. The LPN contains 872 (33%) myelinated axons with a size range of 1–7 μm and a peak at 4 μm. Some 200 of the myelinated axons are muscle efferents. There are 1,969 (67%) C-fibers. After neonatal capsaicin treatment, the number of C-fibers in the LPN is 61% below the normal level, but it is not significantly different from control levels after chemical sympathectomy with guanethidine. The fSPN is composed of 470 (20%) myelinated axons with a size range similar to that in the LPN. Virtually all myelinated fibers are sensory. There are 1,791 (80%) C-fibers. In neonatally capsaicin-treated animals, the occurrence of C-fibers is 65% below control levels. In chemically sympathectomized animals, the number of C-fibers in the fSPN is normal. This description of the fiber composition of the LPN and the fSPN in the rat provides a basis for future experimental studies.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00185434
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 19
    Electronic Resource
    Electronic Resource
    Astrocytic straight tubules in the brain of a patient with Pick's disease (1994)
    Springer
    Acta neuropathologica 88 (1994), S. 587-591 
    Details
    ISSN: 1432-0533
    Keywords: Key words Astrocytes ; Electron microscopy ; Immunocytochemistry ; Pick's disease ; Straight tubules
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract This report concerns an immunohistochemical and ultrastructural study of cerebral astrocytes in a patient with Pick's disease of 20 years' duration. The autopsied brain was prominently small (710   g) with marked fronto-temporal lobar atrophy. Histological examination demonstrated profound neuronal loss and spongy changes with tau-positive Pick bodies in the frontal and temporal cortex. In addition, many glial cells in the temporal lobe white matter contained round to oval, argentophilic and slightly hematoxinophilic cytoplasmic inclusions that were also immunolabeled with the anti-tau antibody. On electron microscopy, the glial inclusions were observed in the perikarya of astrocytes that were recognized as such from intracytoplasmic glial filaments and the presence of gap junctions. The inclusions were free in the cytoplasm, without a limiting membrane, and mainly comprised irregular aggregations of bundles of about 15-nm straight tubules, which were indistinguishable from those of intraneuronal Pick bodies. Furthermore, various patterns of accumulation of the same straight tubules were frequently noted in perivascular astrocytic processes carrying a basal lamina. These findings indicate that in Pick's disease astrocytes are also affected by a similar insult to that which affects neurons.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00296498
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 20
    Electronic Resource
    Electronic Resource
    Cytoplasmic inclusions of astrocytic elements of glial tumors: special reference to round granulated body and eosinophilic hyaline droplets (1994)
    Springer
    Acta neuropathologica 88 (1994), S. 501-510 
    Details
    ISSN: 1432-0533
    Keywords: Round granulated body ; Eosinophilic hyaline droplets ; Astrocytic tumors ; Immunohistochemistry ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Round granulated body (RGB) and eosinophilic hyaline droplets (EHDs) have been described as cytoplasmic inclusions of certain astrocytic tumors. In the previous literature, however, these inclusions have been described using various terms or regarded as nosologically the same entity. Light microscopically, RGB apeared as a round discrete body filled with fine uniform granules, while EHDs demonstrated a cluster of bright eosinophilic, round objects of various size. They could be clearly distinguished even by conventional histochemical staining such as the Masson trichrome stain and the phosphotungstic acid hematoxylin preparation. Both RGB and EHDs expressed positive immunoreactions for glial fibrillary acidic protein, several lysosomal markers, and some stress-response proteins. The ultrastructural appearances of these inclusions were distinct, however, one common feature was that they consisted of aggregations of numerous membrane-bound electron-dense bodies. Thus, both inclusions appear to be produced by neoplastic astrocytes and are possibly related to the lysosomal system. We examined the presence of RGB and EHDs in 138 astrocytic tumors. Both inclusions occurred most frequently in pleomorphic xanthoastrocytomas, followed by gangliogliomas and pilocytic astrocytomas. Subependymal giant cell astrocytomas exhibited only RGBs. RGBs and EHDs were not seen in any abundance in glioblastomas, gliosarcomas, fibrillary astrocytomas, protoplasmic astrocytomas, or oligo-astrocytomas. Some glioblastomas, however, showed only EHDs in small numbers. Several anaplastic astrocytomas were associated with a large number of RGBs and/or EHDs, and they revealed only rare mitosis despite marked cellular pleomorphism. Although RGB and EHDs have different morphological features, the presence of these inclusions in abundance may represent either a degenerative change, a long-standing lesion, or an indolent growth of the astrocytic tumors.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00296486
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 21
    Electronic Resource
    Electronic Resource
    Fine structure of the retinal pigment epithelium in the Port Jackson shark (Heterodontus phillipi) (1994)
    Springer
    Anatomy and embryology 190 (1994), S. 501-506 
    Details
    ISSN: 1432-0568
    Keywords: Retinal pigment epithelium (RPE) ; Electron microscopy ; Elasmobranch ; Heteterodontus phillipi
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The structure of the retinal epithelium (RPE), choriocapillaris and Bruch's membrane (complexus basalis) has been studied by light and electron microscopy in the Port Jackson shark (Heterodontus phillipi). In this elasmobranch the RPE consists of a single layer of low cuboidal cells which show basal (scleral) infoldings and apical (vitreal) processes that enclose photoreceptor outer segments. Laterally these epithelial cells are joined by a series of apically located tight junctions. The RPE cells display a large vesicular nucleus, abundant smooth endoplasmic reticulum as well as numerous polysomes and mitochondria. Phagosomes are present, rough endoplasmic reticulum is scarce and myeloid bodies were not observed. Melanosomes are absent over the choroidally located tapetum lucidum, but are not abundant even in extratapetal areas. This paucity of melanosomes probably makes retinomotor movements unimportant. Bruch's membrane or complexus basalis is a pentalaminate structure. The endothelium of the choriocapillaris is thin but minimally fenestrated.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00235498
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 22
    Electronic Resource
    Electronic Resource
    Fine structure of the choroidal tapetum lucidum in the Port Jackson shark (Heterodontus phillipi) (1994)
    Springer
    Anatomy and embryology 190 (1994), S. 591-596 
    Details
    ISSN: 1432-0568
    Keywords: Tapetum lucidum ; Electron microscopy ; Elasmobranch ; Heterodontus phillipi
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The choroidally located tapetum lucidum of the Port Jackson shark (Heterodontus phillipi) was examined by light and electron microscopy in light-adapted specimens. In this species the tapetum consists of a single layer of overlapping cells oriented at an angle of about 30° to the incoming light and situated immediately external to the choriocapillaris. These tapetal cells alternate with and are separated from one another by melanocytes which extend beyond the tapetal cells to intervene between the tapetal cells and the incoming light. The tapetal cells and the melanocytes are flattened plate-like cells with their widest dimension facing the retina. Internally the tapetal cells display a peripherally located vesicular nucleus with most organelles in a paranuclear location. The bulk of a tapetal cell is packed with regularly spaced crystals reported to be guanine. The size and spacing of these reflective crystals is commensurate with the principles of constructive interference. In light adaptation, the melanosomes of the intervening melanocytes are widely dispersed and for the most part block the passage of light to the tapetal cells. Although dark-adapted specimens were not available, it seems reasonable to assume that in dark adaptation these melanosomes will retreat to unmask the tapetum and allow it to function as a known reflective layer.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00190109
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 23
    Electronic Resource
    Electronic Resource
    Distribution of apoptosis-mediating Fas antigen in human skin and effects of anti-Fas monoclonal antibody on human epidermal keratinocyte and squamous cell carcinoma cell lines (1994)
    Springer
    Archives of dermatological research 286 (1994), S. 396-407 
    Details
    ISSN: 1432-069X
    Keywords: Fas antigen ; Immunohistochemical ; Skin disease ; Keratinocytes ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Fast antigen is a cell surface protein that mediates apoptosis. Using immunohistological, flow cytometry and electron microscopic analyses, we investigated the expression of Fas antigen on various skin tissues, and on cultured SV40-transformed human epidermal keratinocyte cell line KJD and human skin squamous cell carcinoma cell line HSC. The Fas antigen was widely distributed in skin components such as the keratinocytes in the lower portion of the epidermis, epidermal dendritic cells, endothelial cells, fibroblasts, apocrine glands, eccrine sweat glands, sebaceous glands, some normal melanocytes and infiltrating lymphoid cells. It was also strongly expressed on the keratinocytes of lichenoid eruptions seen in lupus erythematosus and lichen planus, and on the spongiotic or acanthotic epidermis seen in chronic eczema, adult T-cell leukaemia/lymphoma (ATLL) and atopic dermatitis. Its expression was closely correlated with lymphoid infiltrating cells and it was strongly expressed in lymphoid neoplastic cells, particularly ATLL cells, and fibroblasts seen in dermatofibroma. However, the antigen was not detected on basal cell epithelioma cells, some malignant melanomas or any junctional naevi. The cell lines KJD and HSC strongly expressed the Fas antigen, and crosslinking of the Fas antigen by an anti-Fas monoclonal antibody induced apoptosis of these cell lines. These results indicate that the apoptosis-mediating Fas antigen may play an important role in normal skin turnover and cell differentiation, in immune regulation of skin tumours, and in the pathogenesis of various skin diseases.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00371800
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 24
    Electronic Resource
    Electronic Resource
    Synaptic connectivity of serotonin graft efferents in the suprachiasmatic and supraoptic nuclei of the hypothalamus (1994)
    Springer
    Experimental brain research 101 (1994), S. 353-364 
    Details
    ISSN: 1432-1106
    Keywords: Transplantation ; Serotonin neurons ; Hypothalamus ; Electron microscopy ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract We have previously reported that a cell suspension from the rostral part of the embryonic raphe grafted to the basal hypothalamus of 5,7-dihydroxytryptamine-denervated rats produced incomplete serotonin (5-HT) re-innervation of the suprachiasmatic nucleus (SCN) as opposed to hyper-innervation of the supraoptic nucleus (SON). We took advantage of this experimental model to investigate whether the graft-derived, 5-HT fibres retained normal ultrastructural features, and, particularly, a normal density of synaptic junctions, irrespective of the extent of target re-innervation. The intrinsic features of immunostained, graft-derived 5-HT axonal varicosities in both the SCN (ventral portion) and the SON were essentially similar to those exhibited by the respective endogenous innervation. Analysis of well-preserved varicosities in uninterrupted series of thin sections allowed us to evaluate directly the proportions of junctional to non-junctional 5-HT varicosities in both regions. Synaptic incidences were also remarkably conserved after grafting (45.5% in the SCN versus 38.5% in the SON; 48% and 38% in normal rats, respectively). Synapses were primarily reestablished on dendritic shafts, which also were identified as the major post-synaptic targets of the normal 5-HT innervations. We noted, however, a tendency toward increased numbers of symmetrical versus asymmetrical synapses in both the SCN and SON of grafted rats. Thus, irrespective of whether hypo-or hyper-innervation patterns developed post-grafting, the transplanted 5-HT neurons essentially retained normal ultrastructural features in their target territories, with a normal incidence of synaptic junctions. The data provide further support to the hypothesis that the innervation territory is the major determinant of the frequency with which ingrowing 5-HT fibres make synaptic junctions.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00227329
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 25
    Electronic Resource
    Electronic Resource
    Ammonium-excreting Azospirillum sp. become intracellularly established in maize (Zea mays) para-nodules (1994)
    Springer
    Biology and fertility of soils 17 (1994), S. 1-8 
    Details
    ISSN: 1432-0789
    Keywords: Ammonium excretion ; Azospirillum brasilense ; Auxine ; 2,4-Dichlor-phenoxy-acetic acid ; Nitrogen fixation ; Paranodulation ; Maize ; Zea mays ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geosciences , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Maize seedlings develop nodule-like tumour knots (para-nodules) along primary roots when treated with the auxin 2,4-dichlor-phenoxy-acetic acid (2,4-D). Inoculated NH 4 + -excreting Azospirillum brasilense cells were shown to colonize these tumours, mostly intracellularly, promoting a high level of N2 fixation when microaerophilic conditions were imposed. The nitrogenase activity inside the para-nodules was less sensitive to free O2 than in non-para-nodulating roots. Both light and electron microscopy showed a dense bacterial population inside intact tumour cells, with the major part of the cell infection along a central tumour tissue. The bacteria colonized the cytoplasm with a close attachment to inner cell membranes. In an auxin-free growth medium, young 2,4-D-induced para-nodules grew further to become mature differentiated root organs in which introduced bacteria survived with a stable population. These results provide evidence that gramineous plants are potentially able to create a symbiosis with diazotrophic bacteria in which the NH 4 + -excreting symbiont will colonize para-nodule tissue intracellularly, thus becoming well protected.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00418663
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 26
    Electronic Resource
    Electronic Resource
    Ultrastructure of an extreme thermophilic hydrogen-oxidizing bacterium Calderobacterium hydrogenophilum (1994)
    Springer
    Archives of microbiology 162 (1994), S. 267-271 
    Details
    ISSN: 1432-072X
    Keywords: Key words     Extremely thermophilic eubacterium ; Calderobacterium hydrogenophilium ; Ultrastructure ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract       Calderobacterium hydrogenophilum is an extreme thermophilic, obligately chemoautotrophic, hydrogen-oxidizing bacterium. The cells were shown to be non-motile straight rods of average size 0.4 × 2.5 μm. After negative-staining of the whole cells, no flagella were observed. The multilayered cell wall was of type 1 and possessed a crystalline proteinaceous surface layer exhibiting p4 symmetry. The square unit cells had a lattice constant of approximately 11 nm. Cell division occurred by a constriction mechanism. C. hydrogenophilum differred from a similar hydrogen-oxidizing eubacterium, Hydrogenobacter thermophilus, by the absence of intracytoplasmic membrane structures in chemically fixed cells. However, an electron-dense intracytoplasmic hemispherical structure adhering to the inner membrane was frequently observed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00301849
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 27
    Electronic Resource
    Electronic Resource
    Ultrastructure of an extreme thermophilic hydrogen-oxidizing bacterium Calderobacterium hydrogenophilum (1994)
    Springer
    Archives of microbiology 162 (1994), S. 267-271 
    Details
    ISSN: 1432-072X
    Keywords: Extremely thermophilic eubacterium ; Calderobacterium hydrogenophilium ; Ultrastructure ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Calderobacterium hydrogenophilum is an extreme thermophilic, obligately chemoautotrophic, hydrogen-oxidizing bacterium. The cells were shown to be nonmotile straight rods of average size 0.4x2.5 μm. After negative-staining of the whole cells, no flagella were observed. The multilayered cell wall was of type 1 and possessed a crystalline proteinaceous surface layer exhibiting p4 symmetry. The square unit cells had a lattice constant of approximately 11 nm. Cell division occurred by a constriction mechanism. C. hydrogenophilum differred from a similar hydrogen-oxidizing eubacterium, Hydrogenobacter thermophilus, by the absence of intracytoplasmic membrane structures in chemically fixed cells. However, an electron-dense intracytoplasmic hemispherical structure adhering to the inner membrane was frequently observed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00301849
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 28
    Electronic Resource
    Electronic Resource
    Membrane topology of insulin receptors reconstituted into lipid vesicles (1994)
    Springer
    The journal of membrane biology 140 (1994), S. 215-223 
    Details
    ISSN: 1432-1424
    Keywords: Insulin receptor ; Membrane reconstitution ; Electron microscopy ; Quaternary structure ; Immunogold labeling
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Insulin receptors were incorporated into liposomes by two different procedures, one using dialysis and one using detergent removal by Bio-Beads. Receptor incorporation was analyzed by gradient centrifugation and electron microscopy. Reconstituted receptors projected up to 12 nm above the membrane and exhibited a T-shaped structure compatible with that previously described for the solubilized receptor. Insulin binding and autophosphorylation experiments indicated that approx. 50% of the receptors were incorporated right-side out. Such random orientation was confirmed by immunogold labeling of the α- and the β-subunit of the receptor. Immunogold labeling of the C-terminus of the β-subunit indicates that it resides about 6 nm off the membrane, while two α-subunit epitopes were labeled at about twice this distance, confirming that the α-subunit is harbored in the cross-bar of the T-structure.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00233710
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 29
    Electronic Resource
    Electronic Resource
    Astrocytes alter their polarity in organotypic slice cultures of rat visual cortex (1994)
    Springer
    Cell & tissue research 277 (1994), S. 557-564 
    Details
    ISSN: 1432-0878
    Keywords: Key words: Slice culture ; Cerebral cortex ; Astrocytes ; Orthogonal arrays of particles - Freeze-fracture ; Electron microscopy ; Rat (Lewis)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. The ultrastructure of astrocytes in an organotypic slice culture of the rat visual cortex was investigated using ultrathin sections and freeze-fracture replicas. After a culture period of 9–15 days, a glial scaffold formed that separated the bulk of the slice neuropil from the medium and the underlying plasma clot. However, the glial cells and processes did not build a dense barrier but allowed the outgrowth of neurites. A basal lamina covering the medium-oriented surface of the astrocytes was not found. In freeze-fracture replicas, orthogonal arrays of particles (OAP) were characteristic components of astrocytic membranes. The OAP density in membranes bordering the medium was 35±13 OAP/μm2, corresponding to 2.5% of this membrane area; the OAP density in membranes within the slice neuropil was 22±12 OAP/μm2, corresponding to 1.4% of this membrane area. Although the difference was significant, it was greatly reduced when comparing OAP densities in endfoot and non-endfoot membranes in vivo. Another mode of polarity was recognized in astrocytes of the organotypic slice culture. In membranes of astrocytes bordering upon the medium, the density of non-OAP intramembranous particles (IMP) was clearly higher (1130±136 IMP/μm2) than in membranes of astrocytes in the center of the slice (700±172 IMP/μm2). This pronounced IMP-related polarity was observed neither in vivo nor in cultured astrocytes. The present study suggests, together with data from the literature, that the distribution of astrocytic OAP across the cell surface is influenced by the existence of a basal lamina and neuronal activity, and that astrocytes possess a more remarkable plasticity of membrane structure than previously suspected.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00300229
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 30
    Electronic Resource
    Electronic Resource
    Organization of the endoplasmic reticulum in renal cell lines MDCK and LLC-PK1 (1994)
    Springer
    Cell & tissue research 277 (1994), S. 297-307 
    Details
    ISSN: 1432-0878
    Keywords: Endoplasmic reticulum ; Cellular transport ; Mitochondria ; Electron microscopy ; Contocal microscopy ; MDCK cells ; LLC-PK1 cells
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The spatial organization of the endoplasmic reticulum has been studied in two renal cell lines, MDCK and LLC-PK1, which originate from the distal and proximal portions of the mammalian nephron, respectively, and which form a polarized epithelium when they reach confluence in tissue culture. The two renal cell lines, grown to confluence on either solid or permeable supports, were investigated by fluorescence microscopy, confocal microscopy, and transmission electron microscopy. Fluorescence labeling of the endoplasmic reticulum was achieved using the cationic fluorescent dye DIOC6 (3). In order to differentiate fluorescent labeling of the endoplasmic reticulum from that of the mitochondria, cells were also labeled with rhodamine 123. For electron microscopy, the spatial organization of the endoplasmic reticulum was examined in thick sections using the long-duration osmium impregnation technique or the ferrocyanide/osmium technique. In both cell lines, the endoplasmic reticulum formed an abundant tubular network of canaliculi that frequently abutted the basolateral domain of the plasma membrane and occasionally the apical membrane. Elements of the endoplasmic reticulum were also found in close proximity to mitochondria that, as in the nephron, formed branched structures. Canaliculi appeared circular or flattened and had an inner diameter of 10–70 nm for MDCK cells and 20–90 nm for LLC-PK1 cells. Such a three-dimensional organization might facilitate the translocation of defined lipid species between the endoplasmic reticulum and the plasma membrane, and between the endoplasmic reticulum and mitochondria.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00327777
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 31
    Electronic Resource
    Electronic Resource
    Organization of the endoplasmic reticulum in renal cell lines MDCK and LLC-PK1 (1994)
    Springer
    Cell & tissue research 277 (1994), S. 297-307 
    Details
    ISSN: 1432-0878
    Keywords: Key words: Endoplasmic reticulum ; Cellular transport ; Mitochondria ; Electron microscopy ; Confocal microscopy ; MDCK cells ; LLC-PK1 cells
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. The spatial organization of the endoplasmic reticulum has been studied in two renal cell lines, MDCK and LLC-PK1, which originate from the distal and proximal portions of the mammalian nephron, respectively, and which form a polarized epithelium when they reach confluence in tissue culture. The two renal cell lines, grown to confluence on either solid or permeable supports, were investigated by fluorescence microscopy, confocal microscopy, and transmission electron microscopy. Fluorescence labeling of the endoplasmic reticulum was achieved using the cationic fluorescent dye DIOC6 (3). In order to differentiate fluorescent labeling of the endoplasmic reticulum from that of the mitochondria, cells were also labeled with rhodamine 123. For electron microscopy, the spatial organization of the endoplasmic reticulum was examined in thick sections using the long-duration osmium impregnation technique or the ferrocyanide/osmium technique. In both cell lines, the endoplasmic reticulum formed an abundant tubular network of canaliculi that frequently abutted the basolateral domain of the plasma membrane and occasionally the apical membrane. Elements of the endoplasmic reticulum were also found in close proximity to mitochondria that, as in the nephron, formed branched structures. Canaliculi appeared circular or flattened and had an inner diameter of 10–70 nm for MDCK cells and 20–90 nm for LLC-PK1 cells. Such a three-dimensional organization might facilitate the translocation of defined lipid species between the endoplasmic reticulum and the plasma membrane, and between the endoplasmic reticulum and mitochondria.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004410050156
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 32
    Electronic Resource
    Electronic Resource
    Progressive reorganization of the myenteric plexus during one year following reanastomosis of the ileum of the guinea pig (1994)
    Springer
    Cell & tissue research 277 (1994), S. 259-272 
    Details
    ISSN: 1432-0878
    Keywords: Key words: Ileum ; Transection ; Reanastomosis ; Myenteric plexus ; NADH diaphorase histochemistry ; Neuron-specific enolase ; Electron microscopy ; Guinea pig
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. The enteric nervous system appears to play a pivotal role in the functional recovery of the gastrointestinal tract after partial resection and reanastomosis, but the structural changes following surgery are not fully understood. The present study was designed to clarify the processes of myenteric plexus regeneration up to one year after transection and reanastomosis of the ileum of the guinea pig. The following techniques were used: nicotinamide adenine dinucleotide (NADH) diaphorase histochemistry, immunostaining of neuron-specific enolase (NSE) in whole-mount preparations, and transmission electron microscopy. Two months after transection and reanastomosis, myenteric ganglion cells with NADH diaphorase reactions were scarce in the center of the lesion, and were less numerous in adjacent areas (3 mm in width) than in the control ileum. In the areas adjacent to the lesion, a few large extraganglionic neurons that did not completely compensate for the loss of ganglion neurons were observed. The remaining ileum showed no changes in NADH diaphorase staining pattern at this stage. Two to 12 months after transection and reanastomosis, ectopic large neurons gradually increased in number not only in the areas adjacent to the lesion but also in part of the remaining ileum, up to 10 cm from the lesion. Concomitantly, large ganglion neurons decreased in number in these areas. In other ileal regions (more than 10 cm distant from the site of transection), no obvious changes in NADH diaphorase staining were noted throughout the observation period. The outgrowth of NSE-containing nerve fibers from the severed stumps was seen two weeks after transection. Six weeks later, numerous bundles of fine nerve fibers with NSE were shown to interconnect the oral and anal cut ends of the myenteric plexus, but they exhibited no subsequent alterations. Transmission electron microscopy revealed that regenerating nerve fiber bundles appeared initially among irregularly arranged smooth muscle cells eight weeks after the operation, as expected from light-microscopic observations. These findings suggest that myenteric ganglion cell bodies, unlike myenteric nerve fibers, require a longer term of reconstruction than previously believed after transection and reanastomosis of the ileum of the guinea pig.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s004410050153
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 33
    Electronic Resource
    Electronic Resource
    Progressive reorganization of the myenteric plexus during one year following reanastomosis of the ileum of the guinea pig (1994)
    Springer
    Cell & tissue research 277 (1994), S. 259-272 
    Details
    ISSN: 1432-0878
    Keywords: Ileum ; Transection ; Reanastomosis ; Myenteric plexus ; NADH diaphorase histochemistry ; Neuron-specific enolase ; Electron microscopy ; Guinea pig
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The enteric nervous system appears to play a pivotal role in the functional recovery of the gastrointestinal tract after partial resection and reanastomosis, but the structural changes following surgery are not fully understood. The present study was designed to clarify the processes of myenteric plexus regeneration up to one year after transection and reanastomosis of the ileum of the guinea pig. The following techniques were used: nicotinamide adenine dinucleotide (NADH) diaphorase histochemistry, immunostaining of neuron-specific enolase (NSE) in whole-mount preparations, and transmission electron microscopy. Two months after transection and reanastomosis, myenteric ganglion cells with NADH diaphorase reactions were scarce in the center of the lesion, and were less numerous in adjacent areas (3 mm in width) than in the control ileum. In the areas adjacent to the lesion, a few large extraganglionic neurons that did not completely compensate for the loss of ganglion neurons were observed. The remaining ileum showed no changes in NADH diaphorase staining pattern at this stage. Two to 12 months after transection and reanastomosis, ectopic large neurons gradually increased in number not only in the areas adjacent to the lesion but also in part of the remaining ileum, up to 10 cm from the lesion. Concomitantly, large ganglion neurons decreased in number in these areas. In other ileal regions (more than 10 cm distant from the site of transection), no obvious changes in NADH diaphorase staining were noted throughout the observation period. The outgrowth of NSE-containing nerve fibers from the severed stumps was seen two weeks after transection. Six weeks later, numerous bundles of fine nerve fibers with NSE were shown to interconnect the oral and anal cut ends of the myenteric plexus, but they exhibited no subsequent alterations. Transmission electron microscopy revealed that regenerating nerve fiber bundles appeared initially among irregularly arranged smooth muscle cells eight weeks after the operation, as expected from light-microscopic observations. These findings suggest that myenteric ganglion cell bodies, unlike myenteric nerve fibers, require a longer term of reconstruction than previously believed after transection and reanastomosis of the ileum of the guinea pig.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00327773
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 34
    Electronic Resource
    Electronic Resource
    Astrocytes alter their polarity in organotypic slice cultures of rat visual cortex (1994)
    Springer
    Cell & tissue research 277 (1994), S. 557-564 
    Details
    ISSN: 1432-0878
    Keywords: Slice culture ; Cerebral cortex ; Astrocytes ; Orthogonal arrays of particles ; Freeze-fracture ; Electron microscopy ; Rat (Lewis)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The ultrastructure of astrocytes in an organotypic slice culture of the rat visual cortex was investigated using ultrathin sections and freeze-fracture replicas. After a culture period of 9–15 days, a glial scaffold formed that separated the bulk of the slice neuropil from the medium and the underlying plasma clot. However, the glial cells and processes did not build a dense barrier but allowed the outgrowth of neurites. A basal lamina covering the medium-oriented surface of the astrocytes was not found. In freeze-fracture replicas, orthogonal arrays of particles (OAP) were characteristic components of astrocytic membranes. The OAP density in membranes bordering the medium was 35±13 OAP/μm2, corresponding to 2.5% of this membrane area; the OAP density in membranes within the slice neuropil was 22±12 OAP/μ2, corresponding to 1.4% of this membrane area. Although the difference was significant, it was greatly reduced when comparing OAP densities in endfoot and non-endfoot membranes in vivo. Another mode of polarity was recognized in astrocytes of the organotypic slice culture. In membranes of astrocytes bordering upon the medium, the density of non-OAP intramembranous particles (IMP) was clearly higher (1130±136 IMP/ μm2) than in membranes of astrocytes in the center of the slice (700±172 IMP/μm2). This pronounced IMP-related polarity was observed neither in vivo nor in cultured astrocytes. The present study suggests, together with data from the literature, that the distribution of astrocytic OAP across the cell surface is influenced by the existence of a basal lamina and neuronal activity, and that astrocytes possess a more remarkable plasticity of membrane structure than previously suspected.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00300229
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 35
    Electronic Resource
    Electronic Resource
    Fine structure and lectin histochemistry of the apical surface of the free neuromast of Lampetra japonica (1994)
    Springer
    Cell & tissue research 276 (1994), S. 245-252 
    Details
    ISSN: 1432-0878
    Keywords: Neuromast ; Hair cells ; Surface coat ; Electron microscopy ; Lectin histochemistry ; Lampetra japonica (Cyclostomata)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The surface coat, ciliary process, and microvilli of the lamprey neuromast were examined with electron microscopy after tannic acid prefixation and lectin histochemistry. The neuromast was found to exist in the form of a dermal mound with a furrow in the middle. On the bottom of the furrow, the hair cell was characterized by a kinocilium and 15–20 stereocilia, arranged along the longitudinal axis of the furrow. Spanning structures were demonstrated between the kinocilium and stereocilia as well as between stereocilia. The surface coat, enhanced by tannic acid prefixation, was particularly rich over the surface of the supporting cell; by contrast, it was thin over the hair cell. Some lectins (PNA, GS-I, SBA, WGA) showed affinity to the surface coat of the supporting cell as well as the hair cell, and the others (RCA-I, MPA, ConA) showed affinity only to the supporting cell. These differences in the structure and affinities of the surface coat suggest an extracellular milieu highly specialized for the hair cell in this particular form of the mechanoreceptor.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00306110
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 36
    Electronic Resource
    Electronic Resource
    Zona glomerulosa of the adrenal gland in a transgenic strain of rat: a morphologic and functional study (1994)
    Springer
    Cell & tissue research 278 (1994), S. 21-28 
    Details
    ISSN: 1432-0878
    Keywords: Adrenal cortex ; Renin-angiotensin system ; Steroidogenesis ; Electron microscopy ; Morphometry ; Rat, transgenic (mRen2) 27
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Transgenic rats for the murine Ren-2 gene display high blood pressure, low circulating levels of angiotensin II, and high renin content in the adrenal glands. Moreover, transgenic rats possess and increased aldosterone secretion (maximal from 6 to 18 weeks of age), paralleling the development of hypertension. To investigate further the cytophysiology of the adrenal glands of this strain of rats, we performed a combined morphometric and functional study of the zona glomerulosa of 10-week-old female transgenic rats. Morphometry did not reveal notable differences between zona glomerulosa cells of transgenic and age- and sex-matched Sprague-Dawley rats, with the exception of a marked accumulation of lipid droplets, in which cholesterol and cholesterol esters are stored. The volume of the lipid-droplet compartment underwent a significant decrease when transgenic rats were previously injected with angiotensin II or ACTH. Dispersed zona glomerulosa cells of transgenic rats showed a significantly higher basal aldosterone secretion, but their response to angiotensin II and ACTH was similar to that of Sprague-Dawley animals. Angiotensin II-receptor number and affinity were not dissimilar in zona glomerulosa cells of transgenic and Sprague-Dawley rats. These data suggest that the sustained stimulation of the adrenal renin-angiotensin system in transgenic animals causes an increase in the accumulation in zona glomerulosa cells of cholesterol available for steroidogenesis, as indicated by the expanded volume of the lipid-droplet compartment and the elevated basal steroidogenesis. However, the basal hyperfunction of the zona glomerulosa in transgenic animals does not appear to be coupled with an enhanced responsivity to its main secretagogues, at least in terms of aldosterone secretion.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00305774
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 37
    Electronic Resource
    Electronic Resource
    Morphological studies by light and electron microscopy of pancreatic acinar cells under the effect of Tityus serrulatus venom (1994)
    Springer
    Cell & tissue research 278 (1994), S. 255-264 
    Details
    ISSN: 1432-0878
    Keywords: Key words: Scorpion venom ; Exocrine pancreas ; Secretagogue ; Electron microscopy ; Pancreatitis ; cis-Golgi aggregates
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. We studied in vivo and in vitro morphological aspects of pancreatic acinar cells after treatment with Tityus serrulatus venom (TSV). After three hours in an in vitro system, positive secretagogue effects of the venom were identifiable both at the light-microscopic (LM) and the electron-microscopic (EM) levels. At 1 μg/ml TSV, maximal secretion (as measured in a concomitant radiolabeling dose-response experiment) of exocrine proteins at 58% was manifest as a discharge of most zymogen granules (ZG) and consequent appearance of secretory material in acinar lumina. At the supramaximal dose of 10 μg/ml TSV, exocytotic images were often observed also with secretory contents previously discharged. The lowest dose of venom at 0.01 μg/ml caused no stimulation of zymogen discharge above resting secretion levels; however, morphological changes were observed. At high doses of TSV, both in vivo and in vitro, large aggregates associated with the cis-Golgi develop between this region and the endoplasmic reticulum (ER). Since Tityus venoms have been associated with causation of pancreatitis, we were interested in comparisons of our experimental tissue with parameters attributed to development of the disease. Our studies have demonstrated considerable evidence that large intracellular vacuoles, discharged ZG, effaced acinar lumina with disappearance of microvilli and other manifestations of possible early events in pancreatitis are indeed frequently observed both in pancreatic lobules in vitro and in whole pancreas in vivo when exposed to TSV.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00414168
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 38
    Electronic Resource
    Electronic Resource
    Zona glomerulosa of the adrenal gland in a transgenic strain of rat: a morphologic and functional study (1994)
    Springer
    Cell & tissue research 278 (1994), S. 21-28 
    Details
    ISSN: 1432-0878
    Keywords: Key words: Adrenal cortex ; Renin-angiotensin system ; Steroidogenesis ; Electron microscopy ; Morphometry ; Rat ; transgenic (mRen2) 27
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract. Transgenic rats for the murine Ren-2 gene display high blood pressure, low circulating levels of angiotensin II, and high renin content in the adrenal glands. Moreover, transgenic rats possess an increased aldosterone secretion (maximal from 6 to 18 weeks of age), paralleling the development of hypertension. To investigate further the cytophysiology of the adrenal glands of this strain of rats, we performed a combined morphometric and functional study of the zona glomerulosa of 10-week-old female transgenic rats. Morphometry did not reveal notable differences between zona glomerulosa cells of transgenic and age- and sex-matched Sprague-Dawley rats, with the exception of a marked accumulation of lipid droplets, in which cholesterol and cholesterol esters are stored. The volume of the lipid-droplet compartment underwent a significant decrease when transgenic rats were previously injected with angiotensin II or ACTH. Dispersed zona glomerulosa cells of transgenic rats showed a significantly higher basal aldosterone secretion, but their response to angiotensin II and ACTH was similar to that of Sprague-Dawley animals. Angiotensin II-receptor number and affinity were not dissimilar in zona glomerulosa cells of transgenic and Sprague-Dawley rats. These data suggest that the sustained stimulation of the adrenal renin-angiotensin system in transgenic animals causes an increase in the accumulation in zona glomerulosa cells of cholesterol available for steroidogenesis, as indicated by the expanded volume of the lipid-droplet compartment and the elevated basal steroidogenesis. However, the basal hyperfunction of the zona glomerulosa in transgenic animals does not appear to be coupled with an enhanced responsivity to its main secretagogues, at least in terms of aldosterone secretion.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00305774
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 39
    Electronic Resource
    Electronic Resource
    Immunocytochemical localization of a growth-associated protein (GAP-43) in rat adrenal gland (1994)
    Springer
    Cell & tissue research 275 (1994), S. 555-566 
    Details
    ISSN: 1432-0878
    Keywords: Adrenal ; Autonomic nervous system ; Schwann cells ; Tyrosine hydroxylase ; GAP-43 ; Electron microscopy ; Immunohistochemistry ; Rat (Wistar)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract We have localized at light and electron-microscopic level the growth-associated protein GAP-43 in adrenal gland using single and double labelling immunocytochemistry. Clusters of GAP-43-immunofluorescent chromaffin cells and many immunofluorescent fibres were observed in the medulla. GAP-43-immunoreactive fibres also formed a plexus under the capsule, crossed the cortex and ramified in the zona reticulata. Double labelled sections showed the coexpression of GAP-43 with a subpopulation of tyrosine hydroxylase-and of dopamine-β-hydroxylase-immunoreactive chromaffin cells. Dual colour immunofluorescence for GAP-43 and calcitonin gene-related peptide (CGRP) revealed that some of the GAP-43-immunoreactive fibres also express CGRP. Pre-embedding electron microscopy showed GAP-43 immunoreactivity associated with the plasma membranes and cytoplasm of noradrenaline-producing chromaffin cells, and with processes of nonmyelin-forming Schwann cells. Immunoreactive unmyelinated axons and terminals were also observed. The immunostained terminals made symmetrical synaptic contacts with chromaffin cells. Immunoreactive unmyelinated fibres and small terminals were present in the cortex. Our results show that GAP-43 is expressed in noradrenergic chromaffin cells and in various types of nerve fibres that innervate the adrenal. Likely origins for these fibres include preganglionic sympathetic fibres which innervate chromaffin cells, postganglionic sympathetic fibres in the cortex, and CGRP containing sensory fibres.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00318824
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 40
    Electronic Resource
    Electronic Resource
    Light- and electron-microscopic study of electrophysiologically characterized neurons in the mediolateral part of the lateral septum of the guinea-pig (1994)
    Springer
    Cell & tissue research 275 (1994), S. 543-553 
    Details
    ISSN: 1432-0878
    Keywords: Lateral septum ; Intracellular injections ; Electron microscopy ; Somatie spines ; Guinea-pig
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract In slices of guinea-pig brains, 36 neurons located in the mediolateral part of the lateral septum were stained intracellularly with horseradish peroxidase (n=28) or biocytin (n=8) after electrophysiological characterization. These neurons belonged to class A neurons (n=23), which generated pronounced Ca++-dependent high-threshold spikes in control medium, or to class C neurons (n=9), which were recognized by the occurrence of small-amplitude sodic spikes followed by slower larger calcic spikes. The present results demonstrate that, despite the variety of individual cell types, the major morphological population (30/36 cells) was composed of a homogeneous class of large-sized neurons that displayed thick primary dendrites and abundant dendritic appendages. The remaining 6 cells were small-sized, poorly-spiny neurons. Somatic spines were observed on 5 out of the 30 large cells and on one out of the six smaller cells. Labeled axons were mainly oriented to the anterior commissure. The axons of nine cells richly collateralized near the perikaryon. Ultrastructural examination of 3 horseradish peroxidase-injected cells showed indented nuclei, classic organelles and somatic spines. Terminal boutons established symmetric synapses with the injected cells. These results describe the morphological features of electrophysiologically identified neurons and indicate that class A and class C neurons are distributed among morphological populations differing in perikaryal size. This suggests that the different electrical properties of class A and class C neurons reflect recordings from different parts of the neuron rather than from neurons of different types. Furthermore, the present findings demonstrate that, in the guinea-pig, electrical and morphological characteristics of somatospiny neurons are comparable with those of non-somatospiny neurons. Somatospiny neurons have a recognized integrative role in the hippocampo-septo-hypothalamic complex.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00318823
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 41
    Electronic Resource
    Electronic Resource
    Quantitative analysis of rod-cored vesicles and dense granules of large granular lymphocytes in the liver, spleen, and peripheral blood of rats (1994)
    Springer
    Cell & tissue research 276 (1994), S. 187-195 
    Details
    ISSN: 1432-0878
    Keywords: Rod-coredvesicles ; Granules ; Lymphocytes ; Liver ; Electron microscopy ; Rat (Fischer F344/NCR)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Large granular lymphocytes (LGL) comprise a natural defense system in the liver and exert an inhibitory effect on tumor cell metastasis. In order to demonstrate the maturation of LGL in the liver from the morphological aspect, we evaluated electron-microscopically the frequency of 0.2 μm vesicles (rod-cored and “empty” vesicles) and dense granules in LGL from the liver, spleen, and peripheral blood of the rat. Both of these cell organelles are characteristic to LGL and may relate to natural killer-mediated cytolysis. On the average, there were 12.7 of the 0.2 μm vesicles and 4.3 rod-cored vesicles (RCV) per cell section in the liver, 6.6 0.2 μm vesicles and 1.6 RCV in the spleen, and 8.6 0.2 μm vesicles and 0.9 RCV in the peripheral blood. The number of 0.2 μm vesicles per cell section ranged from 0 to 19 with the exception of a few higher instances. Therefore, LGL were divided into vesicle-rich(〉9 0.2 μm vesicles per cell section) and vesicle-poor (〈8 per cell section) populations. Hepatic LGL consisted mainly of a vesicle-rich population while splenic LGL consisted mainly of a vesicle-poor population, and peripheral blood contained equal proportions of both populations. In addition to diversity with regard to the number of 0.2 μm vesicles, LGL obtained from various organs also displayed heterogeneity in the number and size of dense granules. Since the number of dense granules per cell section usually ranged from 1 to 13, LGL were diveded into 2 populations, i.e., LGL with many (〉7 per cell section) granules and those with a few(〈6 per cell section) granules. Specifically, splenic LGL had a few small (average diameter, less than 400 nm) dense granules, while sections of LGL from the liver and peripheral blood displayed many small dense granules and a few large (〉400 nm) ones, respectively, in addition to the populations seen in the spleen. Thus, the present study has demonstrateda difference in the distribution of 0.2 μm vesicles in LGL based on the tissue of origin. The present study has revealed the difference in the distribution of 0.2 μm vesicles of LGL by tissue and indicated that immature LGL are predominant in the spleen, while hepatic LGL are generally more mature as defined by the number of vesicles. These data suggest that the microenvironment of the liver may contribute to the increased expression of these vesicles in LGL.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00354799
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 42
    Electronic Resource
    Electronic Resource
    Localization of GABAA receptors in the rabbit retina (1994)
    Springer
    Cell & tissue research 276 (1994), S. 295-307 
    Details
    ISSN: 1432-0878
    Keywords: GABAA receptors ; Light microscopy ; Electron microscopy ; α1 subunit ; β2/3 subunit ; γ2 subunit ; Immunocytochemistry ; Rabbit (New Zealand)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The distribution of gamma-aminobutyric acidA (GABAA) receptors in the rabbit retina is investigated and compared with the distribution of GABAergic neurons using immunocytochemical methods. Antibodies against the α1, β2/3, and γ2 subunits of the GABAA receptor label subpopulations of bipolar, amacrine and ganglion cells. Double labeling experiments show that the γ2 subunit is colocalized with the α1 and the β2/3 subunits in bipolar, amacrine and ganglion cells. Electron microscopy reveals that in the outer plexiform layer, GABAA receptor immunoreactivity is present on dendrites of cone bipolar cells adjacent to the cone pedicles. Bipolar cell dendrites are also receptor-positive at synapses from interplexiform cells. Some receptor immunoreactivity is found intracellularly in processes of horizontal cells. In the inner plexiform layer, GABAA receptor immunoreactivity is present on both rod bipolar and cone bipolar axon terminals at putative GABAergic input sites. Amacrine and ganglion cell processes in sublamina a and b are also labeled.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00306115
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 43
    Electronic Resource
    Electronic Resource
    Negatively-stained polysomes on rough microsome vesicles viewed by electron microscopy: further evidence regarding the orientation of attached ribosomes (1994)
    Springer
    Cell & tissue research 276 (1994), S. 439-444 
    Details
    ISSN: 1432-0878
    Keywords: Polysomes ; Ribosomes ; Subunits ; Liver ; Electron microscopy ; Negative stain ; Rat (Sprague-Dawley)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Rough microsomes, derived from rough endoplasmic reticulum of rat liver, were studied by electron microscopy after negative staining, to seek further information about the orientation of ribosomal small and large subunits in bound polysomes. Rough microsomal vesicles were fixed with 2% formaldehyde, centrifuged onto electron-microscopic grid membranes, and were then negatively-stained with 2% phosphotungstic acid. In these preparations, viewed with the electron microscope, flattened rough microsomal vesicles with bound polysomes were sometimes discernible, and the individual ribosomes in the polysomes occasionally showed small and large subunits. The small subunits were uniformly oriented toward the inside of the polysomal curve. The large and small subunits appeared to be alongside one another on the membrane, consistent with the orientation that has been described by Unwin and his co-workers. The boundary between the small and large subunits occurred at approximately the same level in the ribosome where inter-ribosomal strands have been described previously in surface views of bound polysomes in positively-stained electron-microscopic tissue sections. This further confirms the identity of the strands as messenger RNA.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00343942
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 44
    Electronic Resource
    Electronic Resource
    Morphological studies by light and electron microscopy of pancreatic acinar cells under the effect of Tityus serrulatus venom (1994)
    Springer
    Cell & tissue research 278 (1994), S. 255-264 
    Details
    ISSN: 1432-0878
    Keywords: Scorpion venom ; Exocrine pancreas ; Secretagogue ; Electron microscopy ; Pancreatitis ; cis-Golgi aggregates
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract We studied in vivo and in vitro morphological aspects of pancreatic acinar cells after treatment with Tityus serrulatus venom (TSV). After three hours in an in vitro system, positive secretagogue effects of the venom were identifiable both at the light-microscopic (LM) and the electron-microscopic (EM) levels. At 1 μg/ml TSV, maximal secretion (as measured in a concomitant radiolabeling dose-response experiment) of exocrine proteins at 58% was manifest as a discharge of most zymogen granules (ZG) and consequent appearance of secretory material in acinar lumina. At the supramaximal dose of 10 μg/ml TSV, exocytotic images were often observed also with secretory contents previously discharged. The lowest dose of venom at 0.01 μg/ml caused no stimulation of zymogen discharge above resting secretion levels; however, morphological changes were observed. At high doses of TSV, both in vivo and in vitro, large aggregates associated with the cis-Golgi develop between this region and the endoplasmic reticulum (ER). Since Tityus venoms have been associated with causation of pancreatitis, we were interested in comparisons of our experimental tissue with parameters attributed to development of the disease. Our studies have demonstrated considerable evidence that large intracellular vacuoles, discharged ZG, effaced acinar lumina with disappearance of microvilli and other manifestations of possible early events in pancreatitis are indeed frequently observed both in pancreatic lobules in vitro and in whole pancreas in vivo when exposed to TSV.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00414168
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 45
    Electronic Resource
    Electronic Resource
    Induction and formation ofCochliobolus sativus appressoria (1994)
    Springer
    Protoplasma 178 (1994), S. 34-47 
    Details
    ISSN: 1615-6102
    Keywords: Appressorium ; Cochliobolus sativus ; Electron microscopy ; Thigmotropism ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary GerminatingCochliobolus sativus spores were induced to form appressoria on a variety of artificial surfaces, including replicas of the barley leaf surface. Evidence was obtained for the involvement of chemical and topographic signals during induction of appressorium formation inC. sativus. Germ tube thigmotropism was also observed in vitro. Ultrastructure relevant to appressorium formation was observed, including the germ tube apex, apical swelling of the germ tube apex prior to appressorium formation, the appressorium with associated septation and the penetration peg. Cytochemical probes applied to germlings at the electron microscope level failed to detect α-D-mannan, α-D-glucan, β-D-galactan, D-glcNAc or D-galNAc polymers in the extracellular mucilage associated with the fungal germlings. The ultrastructure of hyphal apices from germlings grown under different nutritional conditions differed with respect to Spitzenkörper morphology, apex shape and in the quantity of associated extracellular mucilage. Experimental findings are discussed relative to current understanding of appressorium induction in more extensively studied systems.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01404119
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 46
    Electronic Resource
    Electronic Resource
    Morphology of sweat glands in determining time of death (1994)
    Springer
    International journal of legal medicine 107 (1994), S. 132-140 
    Details
    ISSN: 1437-1596
    Keywords: Time of death ; Sweat glands ; Immunohistochemistry ; Electron microscopy ; Todeszeit ; Schweißdrüsen Immunhistochemie ; Elektronenmikroskopie
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine , Law
    Description / Table of Contents: Zusammenfassung Diese Untersuchung zeigt postmortale autolytische Veränderungen in der Haut auf zellulärer und subzellulärer Ebene und identifiziert Parameter, welche helfen können, die Zeit des Todes in den ersten Stunden postmortem zu bestimmen. Hautproben von der Beugeseite des Arms wurden, 3, 6, 9 und 12. Stunden nach dem Tode von insgesamt 29 Leichen entnommen (verschiedene Altersklassen, keine Zeichen für Hauterkrankungen, verschiedene Todesursachen). Drei Arten der Untersuchungen wurden durchgeführt: zytochemisch (Hematoxylin-Eosin and Alcian-PAS), immunhistochemisch (S-100, CEA, Cytokeratin, ASM) und ultrastrukturell (Elektronenmikroskopie). Die Elektronenmikroskopie erwies sich als nützlich für die Identifizierung von Transformationen die für jeden chronologischen Schritt spezifisch waren: Reduktion des intrazellulären Glykogens in hellen Zellen und Reduktion der sekretorischen Granula in dunklen Zellen sind typische Zeichen für die erste Phase (3 Stunden) nach dem Tode; mitochondriale Dilatation und Rarifizierung der Cristae in hellen und dunklen Zellen sind typisch für die 2. Phase (6 Stunden); Rarifizierung der Microvilli in dunklen und hellen Zellen sind typisch für die 3. Phase (9 Stunden) und Kernpyknose von dunklen und hellen Zellen ist ein Zeichen der letzten Phase (12 Stunden). Zytochemie und Immunhistochemie sorgen für eine nützliche Information — dies gilt nicht für alle chronologischen Stadien, welche hier einbezogen wurden, aber für individuelle Phasen (3 Stunden für Hematoxylin-Eosin und 6 Stunden für Alcian-PAS). Es ist jedoch besonders wichtig, die Resultate von allen solchen Techniken simultan einzubeziehen, so daß die Frage der exakten Todeszeit innerhalb der ersten 12 Stunden postmortem genauer beantwortet werden kann.
    Notes: Abstract This study demonstrates post-mortem autolytic alterations in the skin at cellular and subcellular levels and identifies parameters which may assist in determining the time of death in the first few hours post-mortem. Serial skin samples from the ventral surface of the arm were taken at intervals of 3, 6, 9 and 12 h after death in 29 subjects of various ages, with no signs of skin disease; causes of death were various. Three types of tests were performed: cytochemical (hematoxylin-eosin and alcian-PAS), immunohistochemical (S-100, CEA, Cytokeratin, ASM) and ultrastructural (electron microscopy). Electron microscopy proved useful for identifying transformations which were found to be specific for each chronological step considered: reduction of intracellular glycogen in clear cells and reduction of secretory granules in dark cells are typcial signs of the first stage (3 h) after death; mitochondrial dilatation and rarefaction of cristae in clear and dark cells are typical of the second stage (6 h); rarefaction of microvilli in dark and clear cells is a sign of the last stage (12 h). Cytochemistry and immunohistochemistry supply useful information — not for all the chronological stage considered here, but for individual phases (3 h for hematoxylin-eosin and 6 h for alcian-PAS). However, it is particularly important to use the results from all such techniques simultaneously, so that the question of the exact time of death within the first 12 h post-mortem may be more accurately answered.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01225600
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 47
    Electronic Resource
    Electronic Resource
    Slowly progressive changes of the retina and retinal pigment epithelium in briard dogs with hereditary retinal dystrophy (1994)
    Springer
    Documenta ophthalmologica 87 (1994), S. 337-354 
    Details
    ISSN: 1573-2622
    Keywords: Animal model ; Briard dogs ; Electron microscopy ; Photoreceptors ; Retinal degeneration ; Retinal pigment epithelium
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Seven eyes from 2 generations of Briard dogs (5 weeks — 7 years old) with congenital night blindness and (in the second generation) impairment of day vision to varying degrees, were examined by light and electron microscopy. Specimens from 4 locations were studied: the central area, the midperiphery of the tapetal area, the upper periphery and the lower periphery. Disorientation of rod outer segment disc membranes was seen in the 5-week-old dog. Large electron-lucent inclusions were found in the RPE at 3.5 months of age. These inclusions occurred most frequently in the central and midperipheral-tapetal areas and seemed to increase in numbers and spread towards the periphery with increasing age. The content of these inclusions is not elucidated. Rod photoreceptor degeneration was apparent from 7 months of age and was most prominent in the peripheral areas. The cones were better preserved. The 7-year-old dog showed reduction of photoreceptors in the central and midperipheral-tapetal areas and almost complete photoreceptor degeneration in the periphery. This dog also showed severe changes of the inner retina in the peripheral fundus. It appears that these Briard dogs suffer from a very slowly progressive retinal degeneration, in which the photoreceptor degenerative changes do not correlate anatomically to the changes in the RPE cells. The disease seems to be different from the retinopathy described in the English Briards. It is not clear yet whether the lipid type of retinopathy found in American Briards is identical to the present disease.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01203343
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 48
    Electronic Resource
    Electronic Resource
    UV-B and early cortical and nuclear changes in the human lens (1994)
    Springer
    Documenta ophthalmologica 88 (1994), S. 255-261 
    Details
    ISSN: 1573-2622
    Keywords: UV-irradiation ; Human lens ; Ageing ; Defense mechanisms ; Biomicroscopy ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Experimental studies in mice and rats have shown that UV (B) irradiation leads to specific lens changes, viz. yellowing of the nucleus and a multilayered epithelium in the anterior pole with disrupted cortical fibres underneath. Biomicroscopic and ultrastructural studies on ageing human lenses revealed yellowing of the lens nucleus and locally ruptured membranes and small opcities in the equatorial cortex. No changes in the anterior pole were ever observed. This discrepancy between the human and animal lens, contraindicating UV as an important risk factor for human cataract, is discussed and may be due to several factors: (1) a difference between the high level acute and low level chronic irradiation; (2) species differences: nocturnal animals may be unable to cope with bright light exposure; (3) differences in scavenger and other defense mechanisms between humans and animals.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01203679
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 49
    Electronic Resource
    Electronic Resource
    Effects of aflatoxin B1 on in vitro cultures ofNicotiana tabacum var. Samsun (1994)
    Springer
    Mycopathologia 125 (1994), S. 93-105 
    Details
    ISSN: 1573-0832
    Keywords: Aflatoxin B1 ; Callus ; Differentiation ; Electron microscopy ; Organogenesis ; Tobacco
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Calli ofNicotiana tabacum (tobacco) were treated with two dose ranges of aflatoxin B1 (0.1–2.0 µg ml−1 - low does; 5–25 µg ml−1 aflatoxin B1). The ability of calli to recover following 3 weeks of toxin exposure was also investigated. The I50 (50% inhibition) value for fresh mass accumulation was approximately 2 µg ml−1 AFB1. Fresh mass accumulation was significantly lower than the control value from 0.5 µg ml−1 AFB1. Following 3 weeks growth without a toxin source, the growth of calli up to and including 10 µg ml−1 AFB1, was significantly greater than control calli, indicating reversibility of the toxic effects. With increasing toxin concentration, chlorophyll content of callus was inhibited from 0.5 µg ml−1. Transfer to a toxin-free medium resulted in a degree of recovery (up to 0.5 µg ml−1). In the dose range 5–25 µg ml−1, the levels of chlorophyll were drastically reduced, with no recovery following AFB1 removal. Electron microscopy revealed a disruption of chloroplast structure as an early deteriorative event in AFB1 exposure of callus cells. Protein levels were less sensitive, with inhibition manifested only in the high dose range. Shoot development occurred at all concentrations, but was significantly inhibited from 5 µg ml−1 AFB1. Recovery following toxin removal was minimal at these higher AFB1 concentrations. The number of necrotic calli increased progressively from 5 µg ml−1 as toxin levels increased.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01371098
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 50
    Electronic Resource
    Electronic Resource
    Electron microscopic and light scattering observation on a system with two iridescent phases (1994)
    Springer
    Colloid & polymer science 272 (1994), S. 604-611 
    Details
    ISSN: 1435-1536
    Keywords: Electron microscopy ; light scattering ; dodecyldimethylaminoxide/hexanol/water ; iridescent phase ; bicontinuous sponge phase ; vesicle phase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract Electron microscopic observations and classical light-scattering measurements have been carried out for dodecyldimethylaminoxide/hexanol/water mixtures in the concentration range where iridescent colors occur. This system has two different iridescent phases. The iridescent phase with more hexanol forms quickly, and the phase with less hexanol forms very slowly. Three different isotropic phases which show strong flow birefringence are found near both iridescent phases. The electron microscopic pictures show clearly that only one of these isotropic phases with strong flow birefringence is a bicontinuous sponge phase (L3h -phase). This is the phase which comes out by adding some alkanol to the upper lamellar phase. The flow birefringent phase below the lower lamellar phase forms unilamellar vesicles. The flow birefringent phase which occurs between both iridescent phases contains multilamellar vesicles and is shown to be a precursor of a lamellar phase.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00653228
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 51
    Electronic Resource
    Electronic Resource
    Ultrastructure of Reissner's membrane in the rabbit (1994)
    Springer
    European archives of oto-rhino-laryngology and head & neck 251 (1994), S. 249-256 
    Details
    ISSN: 1434-4726
    Keywords: Reissner's membrane ; Electron microscopy ; Tubulocisternal endoplasmic reticulum ; Subsurface cistern ; Rabbit
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The ultrastructure of Reissner's membrane in the rabbit is described following vascular perfusion-fixation of live, anesthetized and artificially respirated healthy animals. A new and improved technique of fixation is employed that includes a pressure feedback controlled peristaltic pump and an oxygen-carrying fixative. In ultrathin sections capillaries were observed between the two cell layers comprising Reissner's membrane. The mesothelial cells facing the scala vestibuli were connected by junctional complexes and neither pores nor discontinuities were observed in the cell layer. In the epithelial cells a well-developed tubulocisternal endoplasmic reticulum (TER) was noted. Computerized three-dimensional reconstruction documented the continuity of this TER, from prominent disc-shaped subsurface cisterns lining the luminal cell membrane to smaller subsurface cisterns lining the abluminal and lateral cell membranes, forming a transcellular canalicular pathway. The possible function of the TER in Reissner's membrane is discussed with reference to endolymph/perilymph homeostasis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00181879
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 52
    Electronic Resource
    Electronic Resource
    Morphological changes in the tectorial and basilar membranes of aged rats (1994)
    Springer
    European archives of oto-rhino-laryngology and head & neck 251 (1994), S. 357-360 
    Details
    ISSN: 1434-4726
    Keywords: Presbycusis ; Extracelluar matrix ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Using both light and transmission electron microscopy presbycusic degeneration of the cochlea was observed in particular in the tectorial and basilar membranes, in naturally aged rats. These animals showed a descending auditory pattern as determined by auditory brainstem response. Ultrastructurally, the number of collagen fibers in the tectorial membrane was reduced and straight type A fibers were increased relative to branched, coiled type B fibers. The basilar membrane in the basal turn was also thickened by an increased homogeneous ground substance. These findings indicate that the specificity of vibration of the tectorial and basal membranes is very different in aged and young rats.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00171545
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 53
    Electronic Resource
    Electronic Resource
    A note on chromatographic analysis of enantiomers by indirect method (1994)
    New York, NY : Wiley-Blackwell
    Biomedical Chromatography 8 (1994), S. 52-52 
    Details
    ISSN: 0269-3879
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bmc.1130080114
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 54
    Electronic Resource
    Electronic Resource
    Relations between blood pressure and plasma norepinephrine concentrations after administration of diltiazem to rats: HPLC-peroxyoxalate chemiluminescence determination on an individual basis (1994)
    New York, NY : Wiley-Blackwell
    Biomedical Chromatography 8 (1994), S. 19-21 
    Details
    ISSN: 0269-3879
    Keywords: Rat plasma norepinephrine ; HPLC ; ethylenediamine condensation ; peroxyoxalate chemiluminescence ; blood pressure reduction ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: A calcium antagonist, diltiazem, was infused continuously into Sprague-Dawley rats through the left femoral vein at four different flow rates. The mean arterial blood pressure and concentrations of plasma norepinephrine (NE) were measured in each single rat (n = 5) and the correlations between them were studied. Blood (150 μL) was collected 13 times during the infusion. Plasma NE was determined by HPLC-ethylenediamine condensation reaction-peroxyoxalate chemiluminescence detection system (HPLC-ED-PO-CL).In four cases from 5 rats, the blood pressure reduction caused by diltiazem was inversely correlated to logarithm of plasma NE concentration. The relation was expressed as Y = -α logX + m. The coefficients of correlation were -0.9506, -0.9293, -0.9341 and -0.8675, respectively. The correlation for the last rat was worse (r = -0.0799). The good correlation would imply that the sympathetic nervous system released NE to maintain blood pressure up to the normal level, responding to the blood pressure reduction caused by diltiazem.The present experiment proved the feasibility of the determination method of NE utilizing HPLC-ED-PO-CL detection in applying to the individual rats.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bmc.1130080105
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 55
    Electronic Resource
    Electronic Resource
    Experimental models for optimization of insulin separation on reversed phase columns (1994)
    New York, NY : Wiley-Blackwell
    Biomedical Chromatography 8 (1994), S. 32-36 
    Details
    ISSN: 0269-3879
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Experimentally defined relationships have been found to describe adequately the retention and separation of bovine and porcine insulins as well as their desamido products on reversed phases C4 30 nm and C18 10 nm pore diameter. The equations are valid for a region of initial acetonitrile concentrations from 16 to 31% and gradient rates from 0.04 to 0.60%/min. The peak heights showed an exact non-linear relationship with the time interval between the first and last peak of interest, independent of their retention time.The number of experiments required for obtaining the parametric estimates of the models depends on the particular task, but in all cases is less than eight.The relationships found permit the correct choice to be made in advance both for analysis conditions for a particular column and for different requirements of insulin analysis.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bmc.1130080109
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 56
    Electronic Resource
    Electronic Resource
    Masthead (1994)
    New York, NY : Wiley-Blackwell
    Biomedical Chromatography 8 (1994) 
    Details
    ISSN: 0269-3879
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bmc.1130080201
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 57
    Electronic Resource
    Electronic Resource
    Quantitative analysis of neuroactive amino acids in brain tissue by liquid chromatography using fluorescent pre-column labelling with o-phthalaldehyde and N-acetyl-L-cysteine (1994)
    New York, NY : Wiley-Blackwell
    Biomedical Chromatography 8 (1994), S. 114-118 
    Details
    ISSN: 0269-3879
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: A high-performance liquid chromatographic method for the determination of aspartic acid, glutamic acid, glutamine, glycine, taurine, and γ-aminobutyric acid in brain tissue is described. Amino acids were derivatized with o-phthalaldehyde/N-acetyl-L-cysteine, a fluorescent labelling mixture, in the presence of 0.1 M borate buffer pH 9.5. The derivatization reaction was sensitive to the pH and concentration of borate buffer. A drift in the fluorescent response less than 4% was obtained with the reported conditions after 4 h of reaction. The resolution of the amino acid derivatives was accomplished in a reversed-phase column with a methanol gradient in 50 mM acetate buffer pH 5.5. These conditions also allowed the separation of the major tissue free physiological amino acids. L-Norvaline was used as an internal standard for both peak identification and quantification. Within-day and between-day precision were less than 6.2%, and the accuracy ranged from 99.1 to 104%. The applicability of the method was demonstrated in a study in rats in which the levels of the assayed amino acids in discrete areas of brain were examined.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bmc.1130080304
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 58
    Electronic Resource
    Electronic Resource
    Glutathione and cysteine measurement in biological samples by HPLC with a glassy carbon working detector (1994)
    New York, NY : Wiley-Blackwell
    Biomedical Chromatography 8 (1994), S. 134-136 
    Details
    ISSN: 0269-3879
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: An HPLC method using a glassy carbon working detector for measuring cysteine and reduced glutathione (GSH) in biological samples was developed. Oxidized glutathione (GSSG) was also measured after reduction with glutathione reductase. This study was conducted in human plasma. Cysteine and GSH standard curves were linear in the physiological range, presenting detection limits of 22.0 pmol and 6.0 pmol respectively. Plasmatic results found were 43.92 ± 4.15, 4.50 ± 0.65, and 0.19 ± 0.12 mM (means ± SE), for cysteine, GSH and GSSG, respectively. Peak specificity for cysteine and reduced glutathione was certified by their disappearance after treatment with N-ethylmaleimide.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bmc.1130080308
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 59
    Electronic Resource
    Electronic Resource
    Masthead (1994)
    New York, NY : Wiley-Blackwell
    Biomedical Chromatography 8 (1994) 
    Details
    ISSN: 0269-3879
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bmc.1130080401
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 60
    Electronic Resource
    Electronic Resource
    Simultaneous determination of antidepressant drugs and metabolites by HPLC. Design and validation of a simple and reliable analytical procedure (1994)
    New York, NY : Wiley-Blackwell
    Biomedical Chromatography 8 (1994), S. 158-164 
    Details
    ISSN: 0269-3879
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: An analytical procedure suitable for routine use has been developed and validated for the simultaneous separation and quantification of most of the antidepressant drugs (bicyclic, tricyclic and tetracyclic) and their metabolites in human serum by reversed-phase high performance liquid chromatography with ultraviolet detection. The method has good sensitivity and specificity, without the need for long and complex extraction procedures. The results obtained with three different analytical columns were compared and an improvement in specificity by selection of column and detection wavelength used was achieved.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bmc.1130080403
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 61
    Electronic Resource
    Electronic Resource
    Gas chromatography-mass spectrometry determination of etodolac in human plasma following single epicutaneous administration (1994)
    New York, NY : Wiley-Blackwell
    Biomedical Chromatography 8 (1994), S. 180-183 
    Details
    ISSN: 0269-3879
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: A highly sensitive gas chromatographic-mass spectrometric method for the determination of etodolic acid, as methyl ester, in plasma was developed. The feasibility and specificity of the method was ascertained monitoring the concentration levels in plasma samples collected from 12 male healthy volunteers given epicutaneously 5 g of 10% etodolac gel formulation.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bmc.1130080407
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 62
    Electronic Resource
    Electronic Resource
    TLC - A rapid method for liposome characterization (1994)
    New York, NY : Wiley-Blackwell
    Biomedical Chromatography 8 (1994), S. 193-195 
    Details
    ISSN: 0269-3879
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: One of the most important problems for the use of liposomes as a drug delivery system is the modification of the vesicle induced by the liquid medium in which they are introduced (blood plasma for in vivo studies and the saline buffer solution for in vitro studies).Using thin-layer chromatography (TLC) we compared the behaviour of phosphatidylcholine (used for liposomes preparation) to that of the following unfilled liposomes: multilamellar liposomes (MLV); small unilamellar vesicles (SUV); and reverse phase evaporation vesicles (REV), before and after storage for 15 min in Krebs-Henseleit solution (37°C, pH 7.4, aereated continuously with 95% O2 + 5% CO2). All variants contained the same amount of phosphatidylcholine.Thin-layer chromatography was performed on silica gel 60 as adsorbant. Two types of solvents were tested: one based on chloroform/alcohol (n-butanol or n-propanol or methanol)/water mixture (in different ratios) and another based on alcohol/alcohol/water mixture (n-butanol/n-propanol/water in 4/3/3 volume ratio). In all variants of chloroform containing solvents no differences were found between phosphatidylcholine and all types of liposomes.When using as solvent n-butanol/n-propanol/water significant differences were found between all types of liposomes before and after storage in Krebs-Henseleit solution. Their presence, after TLC treatment, was shown in electron microscopy studies.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bmc.1130080410
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 63
    Electronic Resource
    Electronic Resource
    Improved resolution of tryptic digest fragments from haemoglobin variants using phytic acid in free zone capillary electrophoresis (1994)
    New York, NY : Wiley-Blackwell
    Biomedical Chromatography 8 (1994), S. 202-204 
    Details
    ISSN: 0269-3879
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Capillary electophoresis can be applied to the rapid characterization of tryptic digests of proteins. The addition of phytic acid to the separation buffer was found to improve resolution considerably when the technique was applied to differentiate between tryptic digests derived from variant haemoglobins. Moreover, analysis time was of the order of 15 min, which is considerably shorter than that obtained using gradient reversed-phase high-performance liquid chromatography or two-dimensional paper chromatography-electrophoresis.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bmc.1130080413
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 64
    Electronic Resource
    Electronic Resource
    A non-radioactive iothalamate and p-aminohippuric acid high-performance liquid chromatographic method for simultaneously measuring glomerular filtration rate and renal blood flow in the rat (1994)
    New York, NY : Wiley-Blackwell
    Biomedical Chromatography 8 (1994), S. 224-229 
    Details
    ISSN: 0269-3879
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: A high-performance liquid chromatographic (HPLC) assay method has been developed for the quantitative determination of iothalamate and p-aminohippuric acid (PAH) concentrations in serum and urine samples in the male rat. Glomerular filtration rate (GFR) was measured as clearance of iothalamate, while effective renal blood flow (ERBF) was measured as clearance of PAH. The method is simple, rapid and sensitive and detects iothalamate and PAH in rat serum and urine following administration of bolus doses and continuous infusions of iothalamate and PAH. Samples of serum and urine were deproteinized with two volumes of acetonitrile containing the internal standard, and an aliquot chromatographed on a C18 reversed-phase column. The mobile phase was comprised of 0.1 M sodium phosphate with 1.2 mM tetrabutylammonium phosphate: methanol, 85:15 (v/v), at a flow rate of 1.0 mL/min. The analytical column eluate was monitored with a UV detector at 254 nm with quantitation achieved using peak-height ratios. The precision of the method was 6.6 and 3.6% for iothalamate in serum and urine, and 5.6 and 4.9% for PAH in serum and urine, respectively. The lower limit of quantitation was 0.63 μg/mL for iothalamate and 1.25 μg/mL for PAH in serum, and 3.1 μg/mL for iothalamate and 1.5 μg/mL for PAH in urine. Recovery of iothalamate from serum and urine was 99.9 and 93.5%, respectively. Recovery of PAH from serum and urine was 99.8 and 92.6%, respectively.The present study demonstrated that non-radioactive iothalamate and PAH can be measured simultaneously using a HPLC assay to measure GFR and ERBF in the male rat.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bmc.1130080506
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 65
    Electronic Resource
    Electronic Resource
    Use of capillary electrophoresis for thalassaemia screening (1994)
    New York, NY : Wiley-Blackwell
    Biomedical Chromatography 8 (1994), S. 175-179 
    Details
    ISSN: 0269-3879
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: This paper describes the use of high-performance capillary electrophoresis (HPCE) for screening of thalassaemias. Preparation of globin was performed by adding 1mL of haemolysate to 20 volumes of cold acidified acetone. Separation of globins was accomplished in a 25 mM disodium phosphate buffer at pH 11.8 using an uncoated capillary column of 50 cm × 75 μm (i.d.). Distinct peaks of alpha, beta and gamma were resolved within 6min. The coefficient of variations for within-day and between-day runs were 4.7% and 6.37% respectively. Using this simple and rapid procedure up to 30 specimens could be analysed in a single day. This method appears to be reliable and can be used for mass screening of various haemoglobinopathies.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bmc.1130080406
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 66
    Electronic Resource
    Electronic Resource
    Measurement of theophylline metabolites produced by reaction with hepatic microsome by high performance liquid chromatography following solid phase extraction (1994)
    New York, NY : Wiley-Blackwell
    Biomedical Chromatography 8 (1994), S. 189-192 
    Details
    ISSN: 0269-3879
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: An analytical method has been developed with which to measure the microsomal enzyme activities responsible for oxidative theophylline metabolism. Three metabolites: 3-Methylxanthine (3-MX); 1-methylxanthine (1-MX); 1,3-dimethyluric acid (1,3-DMU), with acetaminophen as an internal standard (IS), were separated by solid phase extraction using a Sep-Pak C18 cartridge, followed by high performance liquid chromatography on a reversed-phase column with isocratic elution using 25 mM acetate buffer containing 4% acetonitrile and 2.5 mM tetra-n-butylammonium hydrogen sulphate (pH 5.25) as the mobile phase. The analytes were clearly resolved and no interference with foreign peaks was observed. A linear relationship was obtained for the metabolites over the concentration range of 0.5-5.0 μg/mL, and their analytical recovery was almost 100%. This method can be used to assess drug interactions involving alterations in the biotransformation of theophylline.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bmc.1130080409
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 67
    Electronic Resource
    Electronic Resource
    Editorial (1994)
    New York, NY : Wiley-Blackwell
    Biomedical Chromatography 8 (1994), S. 205-205 
    Details
    ISSN: 0269-3879
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bmc.1130080502
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 68
    Electronic Resource
    Electronic Resource
    A comparison of fluorescence versus chemiluminescence detection for analysis of the fluorescamine derivative of histamine by HPLC (1994)
    New York, NY : Wiley-Blackwell
    Biomedical Chromatography 8 (1994), S. 207-211 
    Details
    ISSN: 0269-3879
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Fluorescence and chemiluminescence detection were compared for HPLC analysis of the fluorescamine derivative of histamine. The kinetic behaviour of the chemiluminescent response for the derivative was characterized in a static system. An HPLC method was optimized for the derivative using fluorescence detection. Fluorescence detection was linear over the range of 166-1666 pg on column for the fluorescamine-histamine derivative with a limit of detection of 13 pg on column. Using a detector designed for optimal use with chemiluminescence, the chemiluminescence response of the fluorescamine derivative was linear over a range of 1.66-16.6 ng on column with a limit of detection of 1.0 ng on column. These results exemplify a case in which superior detectibility is provided by fluorescence over chemiluminescence, and contradicts many reports comparing fluorescence to chemiluminescence. The authors conclude that chemiluminescence should be considered when indicated by conditions established for separation that are favourable for the observation of chemiluminescence. These conditions include sufficiently low excitation energies corresponding to an excitation maximum greater than 400 nm, favourable dipole character of analytes, mobile phases of high organic content, and an appropriate pH of the mobile phase.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bmc.1130080503
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 69
    Electronic Resource
    Electronic Resource
    HPLC separation of pentazocine enantiomers in serum using an ovomucoid chiral stationary phase (1994)
    New York, NY : Wiley-Blackwell
    Biomedical Chromatography 8 (1994), S. 255-257 
    Details
    ISSN: 0269-3879
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: A stereospecific HPLC method was developed for the analysis of (-) and (+) pentazocine in human serum. Each enantiomer and the internal standard nalophine were isolated from serum using a liquid-liquid extraction procedure. Recoveries of 99.05 ± 5.37 and 97.42 ± 2.78% were obtained for (-) and (+) pentazocine, respectively. Resolution of the enantiomers was obtained by using an ovomucoid chiral stationary phase with a mobile phase of methanol: acetonitrile: 10 mM phosphate buffer, pH 5.8 (20:5.3:74.7 v/v/v). A resolution (Rs) value of 1.80 was obtained for the pentazocine enantiomers. Linear calibration curves were obtained in the 10-100 ng/mL range for each enantiomer in serum. The detection limit based on a signal-to-noise ratio of 3 was 5 ng/mL for each enantiomer in serum using fluorescence detection with excitation at 275 nm and emission set at 335 nm. The lowest quantifiable level was found to be 10 ng for each enantiomer. Precision and accuracy of the method were in the 3.8-4.8% and 1.3-4.2% ranges, respectively.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bmc.1130080512
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 70
    Electronic Resource
    Electronic Resource
    Determination of fluvoxamine concentration in plasma by reversed-phase liquid chromatography (1994)
    New York, NY : Wiley-Blackwell
    Biomedical Chromatography 8 (1994), S. 278-282 
    Details
    ISSN: 0269-3879
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Fluvoxamine, a serotonin re-uptake inhibitor, was quantified in plasma by modifying a previously published procedure for monitoring plasma concentrations of tricyclic antidepressants. Alkalinized plasma samples were extracted with n-hexane/isoamyl alcohol, followed by back-extraction with diluted phosphoric acid, The extracts were analysed by reversed-phase liquid chromatography using a C-18 column, with phosphate/acetonitrile as the mobile phase. The assay was linear from 10 to 800 μg/L. Precision studies showed within-run and day-to-day coefficients of variation to be 4.5 and 6.8%, respectively. Desipramine interfered with the detection of fluvoxamine. The assay was used to measure a total of 8 plasma samples from 4 alcohol-dependent patients medicated with fluvoxamine as an adjunct to relapse prevention psychotherapy. In these patients, the plasma concentrations ranged from 54 to 241 μg/L. Dosage of fluvoxamine, duration of treatment, interval between last dosage and blood collection were associated with effects on plasma concentrations that were consistent with the pharmacokinetic profile of fluvoxamine.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bmc.1130080605
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 71
    Electronic Resource
    Electronic Resource
    Simultaneous determination of p-aminobenzoic acid and its metabolites in urine by high performance liquid chromatography (1994)
    New York, NY : Wiley-Blackwell
    Biomedical Chromatography 8 (1994), S. 294-296 
    Details
    ISSN: 0269-3879
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: We developed a new HPLC method for the determination of p-aminobenzoic acid (PABA) and its metabolites (p-aminohippuric acid, N-acetyl-p-aminohippuric acid, N-acetyl-p-aminobenzoic acid) in urine. As the internal standard m-hydroxybenzoic acid was used. In the isocratic elution the mobile phase consisted of methanol and 0.02 M. ammonium acetate (20:80 v/v, pH 4.0). The separation was carried out on the C18, reversed-phase column, particle size 5 μm. The separated components were detected at 280 nm. The method can be used in the assessment of the response of pancrease (secretion of digestive enzymes) to soya feeding as well as in the diagnosis of the exocrine pancreatic diseases of animals.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bmc.1130080609
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 72
    Electronic Resource
    Electronic Resource
    Solid phase extraction and high performance liquid chromatographic determination of dobutamine in plasma of dialysed patients (1994)
    New York, NY : Wiley-Blackwell
    Biomedical Chromatography 8 (1994), S. 309-312 
    Details
    ISSN: 0269-3879
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: An isocratic reversed-phase high performance liquid chromatographic method has been developed for the determination of dobutamine in the plasma of dialysed patients. A solid phase extraction method with a Sep-Pak C18 cartridge was used to isolate the drug and isoxsuprine (internal standard) from plasma. The separation was carried out on an ODS-Hypersil column with 0.1 M phosphate buffer: acetonitrile: methanol (72 : 20 : 8 v/v/v) as the mobile phase. The recovery of dobutamine added to plasma by the extraction procedure was 87 ± 2.3% (mean ± SD). The accuracy and reproducibility of the method were within acceptable limits over the concentration range 0-1000 ng/ mL. Quantification was by fluorescence detection at 275 nm excitation and 310 nm emission wavelengths with a detection limit of 5 ng/ mL for dobutamine. This procedure was applied to ascertain the pharamacokinetics of dobutamine infusion in nine patients with cardiogenic shock and end-stage renal disease undergoing haemodialysis.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bmc.1130080613
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 73
    Electronic Resource
    Electronic Resource
    Simple determination of formaldehyde in dimedone adduct form in biological samples by high performance liquid chromatography (1994)
    New York, NY : Wiley-Blackwell
    Biomedical Chromatography 8 (1994), S. 313-314 
    Details
    ISSN: 0269-3879
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: A high performance liquid chromatographic method for the determination of endogenous formaldehyde in dimedone adduct form in biological samples is described. The simple procedure involves extraction of the formaldehyde of different binding force in biological samples with methanol containing dimedone as the capture molecule and separation on a C18 reversed phase column with methanol as eluent.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bmc.1130080614
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 74
    Electronic Resource
    Electronic Resource
    Identification and verification of the anabolic steroid boldenone in equine blood and urine by HPLC/ELIS (1994)
    New York, NY : Wiley-Blackwell
    Biomedical Chromatography 8 (1994), S. 63-68 
    Details
    ISSN: 0269-3879
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: An enzyme linked immunosorbent assay (ELISA) was developed to detect the anabolic steroid boldenone in equine blood and urine. The polyclonal antiserum was raised in rabbits, employing boldenone-17-hemisuccinate-bovine serum albumin as antigen. Boldenone-17-hemisuccinate-horseradish peroxidase served as enzyme conjugate. Sensitivity of the assay was 26.0 ± 3.0 pg/well. Among the endogenous steroids tested only progesterone and testosterone exhibited moderate cross-reactivities, 3.4 and 2.5%, respectively. These crossreactivities are of no importance for the boldenone assay. For the reduction of background levels, srceening for boldenone of equine serum was performed after extraction. Urine samples were determined directly after dilution, omitting hydrolysis of boldenone conjugates. Positive screening results were confirmed by means of two independent HPLC systems combined with off-line detection, employing the boldenone ELISA. Methandienone served as internal standard to ascertain retention factors. In horses treated with boldenone-17-undecylenate the presence of boldenone in serum was confirmed up to 28 days and in unhydrolysed urine up to 56 days post applicationem.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bmc.1130080204
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 75
    Electronic Resource
    Electronic Resource
    Automated HPLC analyses of drugs of abuse via direct injection of biological fluids followed by simultaneous solid-phase extraction and derivatization with fluorescence detection (1994)
    New York, NY : Wiley-Blackwell
    Biomedical Chromatography 8 (1994), S. 53-62 
    Details
    ISSN: 0269-3879
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: An automated system is described for the simultaneous extraction and derivatization of nucleophilic compounds from various biological media. The method includes the use of a solid-phase reagent containing a 9-fluorenylacetate activated ester. The reagent is based on a controlled pore, polystyrene divinylbenzene support prepared through a silica template procedure. An X-Y-Z robotic arm equipped with a needle is used in conjunction with a syringe pump for aspirating and dispensing samples and standards into the HPLC system. A precolumn cartridge containing the solid-phase reagent is put on-line in place of the fixed-volume injection loop. Injections of biological fluids such as urine or plasma with minimal sample treatment and handling are made directly into this reactor. The analytes are dervatized as they are extracted, allowing virtually unlimited sample volumes to be injected. The polymeric cartridge can be used for up to 100 injections without accruing unacceptable reductions in sensitivity. A detection limit of 500 p.p.t. (parts per trillion) of amphetamine in urine was achieved with this system.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bmc.1130080203
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 76
    Electronic Resource
    Electronic Resource
    Reversed-phase HPLC separation and chromatographic-spectral characterization of 17β-(2′-thiazolyl)androst-5-en-3β-ols and their acetates (1994)
    New York, NY : Wiley-Blackwell
    Biomedical Chromatography 8 (1994), S. 95-98 
    Details
    ISSN: 0269-3879
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Simple isocratic HPLC separation of a series of thiazolyl steroids with the 17β-2′ linkage is described. The chromatographic and spectral characterization utilizes both on-the-fly UV spectral maxima and absorbances changes.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bmc.1130080210
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 77
    Electronic Resource
    Electronic Resource
    Electrophoresis in practice: A guide to theory and practice. R. Westermeier VCH, Weinheim, 1993, ISBN 3-527-30012-0, £28.00 (1994)
    New York, NY : Wiley-Blackwell
    Biomedical Chromatography 8 (1994), S. 105-105 
    Details
    ISSN: 0269-3879
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bmc.1130080213
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 78
    Electronic Resource
    Electronic Resource
    A Novel electrophilic reagent, 4-(N-chloroformylmethyl-N-methyl)amino-7-N,N-dimethylaminosulphonyl-2, 1,3-benzoxadiazole (DBD-COCI) for fluorometric detection of alcohols, phenols, amines and thiols (1994)
    New York, NY : Wiley-Blackwell
    Biomedical Chromatography 8 (1994), S. 107-113 
    Details
    ISSN: 0269-3879
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: A novel electrophilic reagent for alcohols, phenols, amines and thiols, 4-(N-chloroformylmethyl-N-methyl)amino-7-N,N-dimethylaminosulphonyl-2, 1, 3-benzoxadiazole (DBD-COCI) was synthesized. The reactivity of the reagent to these nucleophiles was studied using high-performance liquid chromatography (HPLC) with precolumn derivatization techniques.DBD-COCI reacted in benzene solution at the room temperature or 60°C with androsterone (a representative of hydroxyls), (-)-mandelic and D,L-lactic acid (hydroxy acid), estrone (phenol), benzylamine (primary amine), phenetidine (aromatic amine) and α-mercapto-N,2-naphthylacetamide (thiol) to give fluorescent products bearing fluorescence wavelengths at between 543 nm and 555 nm (excitation at between 437 nm and 445 nm). The base catalyst, quinuclidine was required to complete the reaction with the nucleophiles except aromatic amines. The reaction solution was subjected to a reversed phase HPLC and the detection limits of the derivatives were at the femto mol range on column.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bmc.1130080303
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 79
    Electronic Resource
    Electronic Resource
    Proteinergic profiles in cerebrospinal fluid from alcoholic subjects (1994)
    New York, NY : Wiley-Blackwell
    Biomedical Chromatography 8 (1994), S. 137-141 
    Details
    ISSN: 0269-3879
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Minute amounts of cerebrospinal fluid samples from alcoholics were subjected to separation by HPLC-molecular sieving, combined with multispectral UV analysis of the acquired data. A significant difference in the protein/polypeptide pattern within the molecular weight range of 7-10 kDa has been observed between samples, taken directly after detoxification and 2 weeks later. Spectral analysis of the results suggests that the components are of peptidergic nature. On the other hand, albumin content did not differ significantly, suggesting that the blood-brain barrier was not affected. An enzyme marker, dynorphin converting enzyme, remained unchanged in both groups.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bmc.1130080309
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 80
    Electronic Resource
    Electronic Resource
    A need for a uniform approach for indexing data of the stereoisomers (1994)
    New York, NY : Wiley-Blackwell
    Biomedical Chromatography 8 (1994), S. 151-151 
    Details
    ISSN: 0269-3879
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bmc.1130080313
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 81
    Electronic Resource
    Electronic Resource
    Separation of vitamin B complex and folic acid using TLC plates impregnated with some transition metal ions (1994)
    New York, NY : Wiley-Blackwell
    Biomedical Chromatography 8 (1994), S. 196-198 
    Details
    ISSN: 0269-3879
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: The separation of Vitamin B complex and folic acid was achieved on silica gel layers impregnated with Mn++, Fe++, Co++, Ni++, Cu++, Cd++, Zn++ or Mg++ (0.1%, 0.2%, 0.3%, 0.4% of each ion). Three new solvent systems n-propanol: n-butanol: water: ammonia (7:5:1:2, by vol), n-propanol: n-butanol: water: ammonia (7:5:1:1.5, by vol), n-propanol: n-butanol: water: ammonia (7:5:0.75:2, by vol) were developed. The spots of vitamins were located by exposing the chromatoplate to iodine vapours.
    Additional Material: 4 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bmc.1130080411
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 82
    Electronic Resource
    Electronic Resource
    Masthead (1994)
    New York, NY : Wiley-Blackwell
    Biomedical Chromatography 8 (1994) 
    Details
    ISSN: 0269-3879
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bmc.1130080501
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 83
    Electronic Resource
    Electronic Resource
    Masthead (1994)
    New York, NY : Wiley-Blackwell
    Biomedical Chromatography 8 (1994) 
    Details
    ISSN: 0269-3879
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bmc.1130080601
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 84
    Electronic Resource
    Electronic Resource
    Interaction of carboxymethyl-γ-cyclodextrin with anticancer drugs studied by charge-transfer thin-layer chromatography (1994)
    New York, NY : Wiley-Blackwell
    Biomedical Chromatography 8 (1994), S. 267-272 
    Details
    ISSN: 0269-3879
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: The interaction between 22 anticancer drugs and carboxymethyl-γ-cyclodextrin (CM-γ-CD) was studied by reversed-phase charge-transfer thin-layer chromatography and the relative strenth of interaction was calculated. CM-γCD formed inclusion complexes with 11 compounds, the complex always being more hydrophilic than the uncomplexed drug. The inclusion forming capacity of drugs differed considerably according to their chemical structure. Both principal component analysis and cluster analysis found a relationship between the inclusion complex forming capacity and hydrophobicity parameters of anticancer drugs. This result suggests that the preponderant role of hydrophobic interactions is in inclusion complex formation.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bmc.1130080603
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 85
    Electronic Resource
    Electronic Resource
    Comparison of standard chromatographic procedures for the optimal purification of soluble human brain acetylcholinesterase (1994)
    New York, NY : Wiley-Blackwell
    Biomedical Chromatography 8 (1994), S. 259-266 
    Details
    ISSN: 0269-3879
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: With the view of purifying soluble human brain acetylcholinesterse (AChE) into its separate isoforms, various preparative chromatographic procedures were compared. Chromatofocusing of cerebrospinal fluid (CSF) AChE revealed two major activity peaks, whilst that of caudate nucleus AChE showed one major peak, Both CSF and caudate nucleus AChE eluted at isoelectric points (pI) of between 5.5 and 5.2 Chromatofocusing failed to separate AChE into its individual isoforms, based on qualitative isoelectric focusing. Preparative purification by affinity chromatography showed a better AChE yield with the use of procainamide as a ligand, vis-à-vis acridinium. Maximum recovery for CSF and caudate nucleus AChE was 10 and 43% using acridinium and procainamide, respectively. Qualitative analysis by SDS-PAGE of affinity-purified AChE revealed four major bands between 50 and 62kDa, corresponding to the catalytic subunits of AChE as verified by an anti-AChE polyclonal antibody. A size-exclusion column also allowed brain AChE purification, with the latter eluting at a putative molecular mass of 310 kDa. Unfortunately, cation-exchange using the state-of-the-art SMART system failed to separate AChE into its isoforms. AChE aggregation is given as one major obstacle precluding good resolution of isoforms.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bmc.1130080602
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 86
    Electronic Resource
    Electronic Resource
    Direct determination of free phenylacetic acid in human plasma and urine by column-switching high performance liquid chromatography with flurescence detection (1994)
    New York, NY : Wiley-Blackwell
    Biomedical Chromatography 8 (1994), S. 283-287 
    Details
    ISSN: 0269-3879
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: A simple and highly sensitive column-switching high performance liquid chromatographyic method with fluorescence detection for the determination of free phenylacetic acid (PAA) in human plasma and urine is described. The method is based on the direct derivatization of plasma and urine PAA with 6,7-dimethoxy-1-methyl-2(1H)-quinoxalinone-3-propionylcarboxylic acid hydrazide (DMEQ-hydrazide). The derivatization reaction proceeds in aqueous solution in the presence of pyridine and 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide at 37°C. The resulting DMEQ derivative of PAA is separated from endogenous interfering substances by a column-switching chromatographic system consisting of a precolumn (YMC-Pack C4) for sample clean-up and an analytical column (L-Column ODS) for the complete separation of the derivative. The derivative is detected fluorimetrically at 445 nm wih excitation at 367 nm. The detection limits (signal to noise ratio = 3) for PAA is 10 fmol in a 10 μL injection volume. The recoveries from plasma and urine are 75 and 96%, respectively. The present method is highly sensitive and simple compared to conventional liquid-liquid extraction procedures. The sensivity allows the direct determination of free PAA in an extremely small amount (5 μL) of plasma and urine.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bmc.1130080606
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 87
    Electronic Resource
    Electronic Resource
    Optical purity determination of thyroxine enantiomers in bulk materials by chiral thin layer chromatographyAccepted in part for presentation at the 5th International Symposium on Chiral Discrimination, 26-28 September 1994, Stockholm, Sweden. (1994)
    New York, NY : Wiley-Blackwell
    Biomedical Chromatography 8 (1994), S. 317-318 
    Details
    ISSN: 0269-3879
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: L-thyroxine and D-thyroxine were separated on ligand exchange chiral thin layer chromatographic plates, using a solvent system consisting of acetonitrile:methanol:water 60:15:15 v/v, at a wavelength of 254 nm. The methodology, chiral recognition mechanism (s) involved and its application are discussed.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bmc.1130080616
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 88
    Electronic Resource
    Electronic Resource
    Fluidized-bed receptor-affinity chromatography (1994)
    New York, NY : Wiley-Blackwell
    Biomedical Chromatography 8 (1994), S. 236-241 
    Details
    ISSN: 0269-3879
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: A multipurpose fluidized-bed receptor-affinity purification system based upon the biological recognition between an immobilized receptor and its soluble protein ligands is described. The fluidized affinity sorbent consists of a soluble form of interleukin-2 receptor chemically bonded to an aldehyde derivative of controlled pore glass beads, which have a pore diameter of 1000 Å and a particle density of 1.2-1.3 g/mL. The fluidized-bed separation device used in this study consists of a specially designed column fitted at the inlet end with a perforated distributor plate covered with a screen and the top outlet with an adjustable piston. The fluidized-bed consisting of a loose gel matrix permits the unimpeded passage of cell debris and particulate matter, while the target protein is captured by the affinity beads. Purification of the humanized-anti-Tac monoclonal antibody is used as a model system to determine the operational parameters. Also, fluidized-bed receptor-affinity chromatography has been successfully employed in the purification of recombinant interleukin-2 and single chain anti-Tac(Fv)-Pseudomonas exotoxin immunotoxin from unclarified inclusion body extracts. Overall, fluidized-bed receptor-affinity chromatography is found to be a productive affinity method suitable for the purification of recombinant human interleukin-2 and related molecules.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bmc.1130080508
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 89
    Electronic Resource
    Electronic Resource
    High performance liquid chromatographic analysis of polypeptide hormones in transplanted rat islets (1994)
    New York, NY : Wiley-Blackwell
    Biomedical Chromatography 8 (1994), S. 301-305 
    Details
    ISSN: 0269-3879
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: This report describes high performance liquid chromatographic analysis of transplanted pancreatic islets. A reversed phase ODS column made it possible to measure rat insulin I, II, rat C-peptide I, II and glucagon simultaneously in isolated rat islets without using radioisotopes. Freshly isolated islets contained 118.0 ± 9.7 ng (mean ± SE, n = 6) insulin and 3.01 ± 0.60 ng glucagon per islet. The insulin I/II ratio was 1.22 ± 0.03. Isolated islets were then cultured in vitro or transplanted into mice under the renal capsule. Transplantation induced mild hypoglycemia in the recipients. The graft mean survival time was 7.2 ± 0.4 days (n = 5). Both cultured (n = 7) and transplanted (n = 6) islets showed similar alterations of polypepide hormones on day 4. Insulin decreased to one third and glucagon remained unchanged. The insulin I/II ratio increased twofold. In conclusion, it was suggested that the general fate of isolated islets was caused by ischemia and denervation. Relatively, ischemia may not damage α cells but may damage β cells because α cells are peripherally located. Denervation may release β cells from a resting state under neural tonic inhibition. Mild hypoglycemia and an increased insulin I/II ratio were related to the accelerated insulin synthesis in the isolated islets.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bmc.1130080611
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 90
    Electronic Resource
    Electronic Resource
    Determination of nitrite by high-performance liquid chromatography system with electrochemical detector: Measurement of nitric oxide synthase activity in rat cerebellum cytosol (1994)
    New York, NY : Wiley-Blackwell
    Biomedical Chromatography 8 (1994), S. 14-18 
    Details
    ISSN: 0269-3879
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: A simple and sensitive assay method for NO synthase activity is described. Using glassy carbon as electrode and 30% methanol solution with 10 mM NH4Cl as mobile phase, NO2- can be measured without disturbing ECD-detectable substance in NO synthase assay mixture. The NO2- production in the assay mixture of rat cerebellum NO synthase increased with protein and in a time-dependent manner. The Km value for the substrate, L-arginine, was 1.25 μM. The enzyme activity was inhibited in a concentration-dependent manner by a NO synthase inhibitor, NNA. The Ki value for NNA was 0.166 ± 0.060 μM. This ECD-HPLC method for determining NO synthase activity has advantages compared with the diazo-coupling method of the Greiss reagent and the isotopic method in which the conversion of the substrate, [14C]L-arginine, to the product, [14C]L-citrulline is measured; it is simple, sensitive and is convenient for studying the NO synthase activity with various compounds as the substrate.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bmc.1130080104
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 91
    Electronic Resource
    Electronic Resource
    A liquid chromatographic method for the determination of fenoprofen in equine plasma and urine (1994)
    New York, NY : Wiley-Blackwell
    Biomedical Chromatography 8 (1994), S. 29-31 
    Details
    ISSN: 0269-3879
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: A high performance liquid chromatographic method to measure plasma and urine fenoprofen levels in equine biofluids is described. Liquid-liquid extraction with diethylether was used to isolate the drug from plasma and urine. The accuracy and reproducibility of the method were within acceptable limits over the concentration range 0-10 μg/mL and 0-20 μg/mL respectively from plasma and urine. Detection limits were 0.05 μg/mL (2 mL plasma) and 0.2 μg/mL (0.5 mL urine). This procedure was applied to ascertain the pharmacokinetics of a 3 g dose of fenoprofen calcium in a horse.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bmc.1130080108
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 92
    Electronic Resource
    Electronic Resource
    Masthead (1994)
    New York, NY : Wiley-Blackwell
    Biomedical Chromatography 8 (1994) 
    Details
    ISSN: 0269-3879
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bmc.1130080101
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 93
    Electronic Resource
    Electronic Resource
    A fully automated HPLC method for the determination of catecholamines in biological samples utilizing ethylenediamine condensation and peroxyoxalate chemiluminescence detection (1994)
    New York, NY : Wiley-Blackwell
    Biomedical Chromatography 8 (1994), S. 1-8 
    Details
    ISSN: 0269-3879
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: A fully automated in-line extraction reversed-phase high-performance liquid chromatography (HPLC) method with chemiluminescence detection was developed for the analysis of human and rat plasma catecholamines (CAs), norepinephrine (NE), epinephrine (E) and dopamine (DA). N-Methyldopamine (N-MeDA) was used as an internal standard. The method involves collection of plasma samples, which are first diluted with a sample dilution buffer containing N-MeDA, and in-line extraction of CAs using a carboxylic acid small resin precolumn (SERUMOUT-CEX). This pre-extraction process was coupled with an HPLC system including reversed-phase mode separation on an analytical column (TSK gel ODS-80Ts), fluorogenic derivatization with ethylenediamine (ED) and finally postcolumn peroxyoxalate chemiluminescence reaction detection using bis [4-nitro-2-(3,6,9-trioxadecyloxycarbonyl)phenyl]oxalate (TDPO) and hydrogen peroxide. The optimized mobile phase compositions, flow rates, operation timing for the adsorption and desorption of CAs in the precolumn, the separation in the analytical column and the optimum fluorogenic and chemiluminogenic reaction conditions were investigated.The detection limit for all the CAs was about 1 fmol (signal-to-noise ratio is 2). Excellent linearity of the calibration curves for CAs was observed in the range from 5 to 500 fmol for each CA using the internal standard. The relative standard deviations of the method for determining NE (183 fmol), E (23.6 fmol) and DA (6.1 fmol) in 50 μL of human plasma (n = 3) were 2.8, 2.7 and 3.1%, respectively, for the within-day assay and 5.0, 3.8 and 4.0%, respectively, for the between-day assay. The method was applicable to the determination of CAs in 25-50 μL of human or rat plasma.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bmc.1130080102
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 94
    Electronic Resource
    Electronic Resource
    Rapid assay of iopanoic acid in dog plasma using a Hisep column (1994)
    New York, NY : Wiley-Blackwell
    Biomedical Chromatography 8 (1994), S. 26-28 
    Details
    ISSN: 0269-3879
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: A rapid method for the determination of iopanoic acid (IOP) in dog plasma utilizing a Hisep column was developed. A mobile phase of 12% methanol, 88% 0.05 M phosphate buffer pH 3.4 yielded a k′ of 8.5 with no interference from proteins present in plasma. Recoveries of IOP from spiked plasma ranged from 97% to 103% at 270 μmol/L and 1.75 mmol/L respectively. Replication was ±2.8% at 1.75 mmol/L and ±6% at 21 μmol/L. A method utilizing 2,4,6-triiodobenzoic acid as internal standard was also developed for comparison.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bmc.1130080107
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 95
    Electronic Resource
    Electronic Resource
    Erratum (1994)
    New York, NY : Wiley-Blackwell
    Biomedical Chromatography 8 (1994), S. ii 
    Details
    ISSN: 0269-3879
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bmc.1130080202
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 96
    Electronic Resource
    Electronic Resource
    A new matrix for affinity chromatography and its application in the separation of a human monoclonal antibody (1994)
    New York, NY : Wiley-Blackwell
    Biomedical Chromatography 8 (1994), S. 142-144 
    Details
    ISSN: 0269-3879
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: A method for the preparation of a p-aminobenzene sulphonyl ethyl containing crosslinked Sepharose 4B (ABSE-Sepharose 4B-CL) is described. trypsin, bovine serum albumin (BSA) and concanavalin A (Con A) were immobilized onto this matrix by diazotization. Conditions for the coupling reaction were investigated. The activity of immobilized trypsin reached 1.4 × 104U/g, and 25 mg BSA can be coupled onto 1 g ABSE-Sepharose 4B-CL under the optimal conditions. An affinity medium with immobilized Con A as ligand was prepared by this method, and was used in the separation of a human monoclonal antibody.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bmc.1130080310
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 97
    Electronic Resource
    Electronic Resource
    Separation and identification of proteins obtained from Agkistrodon acutus snake venom by capillary zone electrophoresis and laser desorption/ionization mass monitoring (1994)
    New York, NY : Wiley-Blackwell
    Biomedical Chromatography 8 (1994), S. 148-150 
    Details
    ISSN: 0269-3879
    Keywords: Capillary zone electrophoresis ; laser desorption/ionization mass monitoring ; Agkistrodon Acutus snake venom ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Fractions of seven protein principles with fibrinolytic or thrombin-like activities obtained from Agkistrodon acutus snake venom purified by two steps of normal pressure chromatography were separated further by capillary zone electrophoresis (CZE). Mass determination for these fractions were achieved by performing laser desorption/ionization mass monitoring (LDIM). The comparative study between CZE and LDIM on the separation of these fractions was made.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bmc.1130080312
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 98
    Electronic Resource
    Electronic Resource
    Enantiospecific determination of ibuprofen in rat plasma using chiral fluorescence derivatization reagent, (-)-2-[4-(1-aminoethyl)-phenyl]-6-methoxybenzoxazole (1994)
    New York, NY : Wiley-Blackwell
    Biomedical Chromatography 8 (1994), S. 170-174 
    Details
    ISSN: 0269-3879
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: A highly sensitive and reversed-phase high-performance liquid chromatographic method for the determination of the enantiomeric composition of ibuprofen in rat plasma is described. The method is based on the resolution of the diastereomeric amides formed on reaction of the ibuprofen enantiomers with (-)-2-[4-(1-aminoethyl)phenyl]-6-methoxybenzoxazole ((-)-APMB) in the presence of 2,2′-dipyridyl disulphide (DPDS) and triphenylphosphine (TPP) in dichloromethane. The reaction mixture was allowed to stand at room temperature for 5 min, and the reaction was completed by evaporation with a stream of nitrogen at 40°C. The minimum quantifiable concentrations were 0.2 μg/mL and 0.4 μg/mL for S-ibuprofen and R-ibuprofen, respectively, in a 10 μL injection volume. The method was applied to the determination of enantiomeric ibuprofen in plasma after oral administration to rats.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bmc.1130080405
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 99
    Electronic Resource
    Electronic Resource
    Simultaneous determination of a mixture of organophosphorus and carbamate pesticides by high performance liquid chromatography (1994)
    New York, NY : Wiley-Blackwell
    Biomedical Chromatography 8 (1994), S. 153-157 
    Details
    ISSN: 0269-3879
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: A simple HPLC procedure has been developed for the simultaneous determination of a mixture of standard carbaryl, carbofuran, carbendazim, dimethoate, malathion and methyl parathion from a spiked agricultural soil sample. The pesticide mixture has been extracted using methanol-water. A concave gradient elution with acetonitrile-phosphate buffer for 15 min followed by linear elution for 5 min, using a wavelength of 224 nm for detection, has been found to resolve the mixture efficiently.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bmc.1130080402
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 100
    Electronic Resource
    Electronic Resource
    Measurement of amiloride in airway surface liquid utilizing HPLC and fluorescence detection (1994)
    New York, NY : Wiley-Blackwell
    Biomedical Chromatography 8 (1994), S. 219-223 
    Details
    ISSN: 0269-3879
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: A high-performance liquid chromatographic method for the determination of amiloride in airway surface liquid is described. It involves extraction of the drug with methanol from filter paper on which the sample is absorbed and chromatography on a Zorbax Rx column; the mobile phase is 25% acetonitrile in 0.05 M phosphate buffer; detection by fluorescence at 360/420 nm. Triamterene is used as an internal standard. The range of the assay is 2.0-2033.4 ng/sample, with adequate precision and accuracy. A power curve y = axb best describes the relationship between the peak-height ratio and concentration. Recovery of amiloride is non-linear, probably due to an adsorption process. Accuracy of the assay at lower amounts may be affected by the choice of filter paper a well as by presence of endogenous plasma components. The assay was used to measure amiloride amount in airway surface liquid after administration of 2.5 and 4.5 mg of nebulized amiloride.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bmc.1130080505
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...