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  • 1985-1989  (750)
  • 1975-1979
  • 1935-1939
  • 1987  (750)
  • Organic Chemistry  (684)
  • Electron microscopy
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Virchows Archiv 411 (1987), S. 311-314 
    ISSN: 1432-2307
    Keywords: Human pituitary adenomas ; Granules ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Light bodies are large cytoplasmic granules originally described in the gonadotrophic cells of the rat pituitary gland. In order to determine whether similar bodies occur in the human anterior pituitary gland, 89 pituitary adenomas and periadenomatous tissue from 20 cases were examined by transmission electron microscopy. Double membrane bound bodies with filamentous internal structure identical to rodent light bodies were identified in 10 hormone-producing adenomas: 5 PRL, 1 PRL-GH, 2 GH, and 2 ACTH-producing tumours. No light bodies were found in the remaining 79 tumours nor in the pituitary cells in periadenomatous tissue from 20 cases. These results show that some human pituitary adenomas may contain light bodies identical to those seen in gonadotrophs of rat pituitary.
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Virchows Archiv 410 (1987), S. 83-92 
    ISSN: 1432-2307
    Keywords: Buschke-Loewenstein tumour ; Giant condyloma ; Anogenital region ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Results on the light- and electron microscopic studies of six cases of Buschke-Loewenstein tumour are presented. The role of chronic irritation is emphasized in the aetiology of the tumour. Fistulas and abscesses arising in the tumour are dangerous as they give rise to chronic sepsis. In two perianal tumours, in situ or invasive carcinoma developed. Electron microscopy revealed varying degrees of differentiation of keratinocytes. As a result of the defective desmosomes, the tumour cell underwent segregation, with widened intercellular spaces containing oedema, erythrocytes and leucocytes. This phenomenon is probably responsible for frequent bleeding and fistula formation. The investigations disclosed that the Buschke-Loewenstein tumour is a special form of squamous carcinoma and therefore, radical surgical excision must be attempted even in case of a benign histological picture.
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  • 3
    ISSN: 1432-2307
    Keywords: Thrombocytopenic purpura ; Idiopathic thrombocytopenic purpura ; Liver sinusoidal fibrosis ; Electron microscopy ; Immunocytochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary 10 patients with thrombocytopenic purpura (TP) underwent splenectomy. Eight of these patients had idiopathic TP (certain or probable). All had normal liver function tests. Liver histology of the surgical biopsy was normal with the exception of a non specific mild portal infiltration in 6 cases. On Sirius red staining the perisinusoidal network was normal in 3 cases, mildly or moderately increased in 5 cases and often associated with perivenular fibrosis. Collagen types I, III, IV, laminin and fibronectin were increased in the 8 biopsies tested. On semi-thin sections, numerous Kupffer cells were observed. Under the electron microscope, sinusoidal abnormalities were very similar in all 7 patients studied: numerous Kupffer cells containing abundant lysosomes, numerous collagen bundles in the Disse space, active endothelial cells, transformation of some perisinusoidal cells into cells with some of the characteristics of fibroblasts (increased RER) and myofibroblasts (peripheral condensations of the filamentous network), increased fragments of basement membrane-like material. In two cases there was an increase in the number of perisinusoidal cells loaded with lipids. The similarity of the lesions and the absence of other fibrogenic causes (except in 2 cases) suggest that TP may represent another group of diseases with perisinusoidal fibrosis. The aetiology of fibrosis remains unknown but platelet derived growth factor and activated macrophages may play a major role.
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  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Journal of molecular evolution 26 (1987), S. 347-357 
    ISSN: 1432-1432
    Keywords: Ribosome structure ; Electron microscopy ; Image analysis ; Evolutionary lineages
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Multivariate statistical analysis and classification techniques are powerful tools in sorting noisy electron micrographs of single particles according to their principal features, enabling one to form average images with an enhanced signal-to-noise ratio and a better reproducible resolution. We apply this methodology here to determining the characteristic views of the large (50S) ribosomal subunits from the eubacteriumEscherichia coli and the archaebacteriaMethanococcus vannielii, Sulfolobus solfataricus, andHalobacterium marismortui. Average images were obtained of the subunit in the common crown and kidney projections, but views of the particle in orientations intermediate between these two extremes were also elucidated for all species. These averages show reproducible detail of up to 2.0 nm resolution, thus enabling the visualization and interspecies comparison of many structural features as a first step toward comparing the actual three-dimensional structures. Our results disprove evolutionary lineages recently postulated on the basis of electron microscopical images of ribosomal subunits.
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  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Journal of molecular medicine 65 (1987), S. 144-146 
    ISSN: 1432-1440
    Keywords: Campylobacter pyloridis ; Duodenal ulcer ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The ultrastructure of campylobacter-like organisms found within duodenal biopsy specimens from 7 of 24 patients (28%) with active duodenal ulcer is described. Their curved shape and variable size are similar to what has previously been reported in descriptions of light microscopies. The organisms were found at the edge of active duodenal ulcers exclusively near neutral-mucous producing antral cells, to which they can adhere. The presence of these bacteria within cells and in the intercellular fluid implies that they can penetrate through the cell membrane or through tight intercellular junctions. The occurrence of these bacteria as well as numerous polymorphonuclear leukocytes in the afflicted regions suggests that the bacteria originally described by Warren and Marshall are indeed pathogenic and that their influence on ulcer healing should be included in designing treatment protocols.
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  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Archives of toxicology 59 (1987), S. 385-390 
    ISSN: 1432-0738
    Keywords: Lung ; Methyl isocyanate ; Gas poisoning ; Electron microscopy ; Rats
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The static exposure of rats to 0.25 mg/l methyl isocyanate for 1 h resulted in damage to the epithelium of the proximal bronchioles and upper airways. Bronchiolar cells exhibited both nuclear and cytoplasmic damage; many epithelial cells, particularly in the bronchi and trachea, were killed and/or dislodged from the basement membrane. A “raft” of cell debris and fibrin lined most of the airways during the 1st week after exposure but repair to the underlying epithelium was well advanced within 2–3 days. The majority of airways were lined by a normal epithelium within 3 weeks of exposure, but isolated foci of hyperplasia and occluded airways probably accounted for continued respiratory impairment.
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  • 7
    ISSN: 1432-0738
    Keywords: Isopropyl alcohol ; Tracheal mucosa ; Ciliary activity ; Recovery process ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The toxicity of isopropyl alcohol (IPA) on the tracheal mucosa was studied experimentally with special reference to the recovery process of the organ. The results showed that 400 ppm IPA has an acute effect on the mucociliary system in the tracheal mucosa, and that recovery from such degeneration can occur in 2 weeks. When functional and morphological damage was induced by a higher level (5500 ppm) of IPA, recovery did not occur in 2 weeks. The conclusion is that the present allowable level of IPA is reasonable from the viewpoint of the effects of short-term exposure to IPA on the tracheal mucosa. In addition, a higher level of IPA exposure has longer-term effects on the tracheal mucosa, and workers exposed to such a higher level of IPA vapor should be given careful otolaryngological follow-up observations.
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  • 8
    Electronic Resource
    Electronic Resource
    Springer
    Acta neuropathologica 75 (1987), S. 116-122 
    ISSN: 1432-0533
    Keywords: Rat ; Lead ; Brain edema ; Electron microscopy ; Immunohistochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Newborn rats were exposed to daily intraperitoneal injections of 10 mg lead nitrate per kg body weight for the first 15 postnatal days. The growth and mortality of the lead-exposed animals did not differ from their control litter-mates, injected with vehicle only. In our previous studies, focal hemorrhages and spongy areas as well as breakdown of blood-brain barrier to plasma proteins were shown by light microscopy in the cerebellar parenchyma of 15-day-old rats exposed to this dose. In spite of these signs of edema, measurements of brain tissue specific gravity did not show increased water content. In the present investigation we examined the ultrastructure of the brain lesions in these rats with low-dose lead encephalopathy, focusing on signs of edema, and evaluated astroglial reaction by immunocytochemical staining for glial fibrillary acidic protein (GFAP). The electron microscopic findings were compatible with extracellular edema in the cerebellum of 15-day-old lead exposed rats. The number of GFAP-positive cell bodies in the gray substance of the cerebellar cortex was increased in the 15-day-old lead-exposed rats as compared with the controls of the same age, a finding which is presumably related to the leakage of plasma proteins. Both these findings were lacking at 20 days of age, suggesting reversibility of the lead-induced changes.
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  • 9
    ISSN: 1432-0533
    Keywords: Pleomorphic xanthoastrocytoma ; Epithelial properties ; Circumscribed growth ; Electron microscopy ; Immunohistochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Three cases of pleomorphic xanthoastrocytoma (PXA), one of which showed anaplastic evolution, are described. In all three the PXA tumors were well circumscribed and could be totally removed. Light-microscopically, pleomorphic tumor cells clustered gregariously and often formed alveolar structures. Electron microscopy revealed various epithelial properties, such as junctions and interdigitations between apposing tumor cells, and prominent basal laminae surrounding tumor nests. The circumscribed growth of PXA, as contrasted with an infiltrative growth of usual astrocytoma, can be attributed to the cellular cohesion based on the epithelial properties of the tumor cells. In the third patient, tumor recurred 6 months postoperatively. Although the recurrent tumor retained the alveolar structures, pleomorphism and various degenerative features of the tumor cells diminished with advance in the proliferative activities.
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  • 10
    Electronic Resource
    Electronic Resource
    Springer
    Anatomy and embryology 176 (1987), S. 251-258 
    ISSN: 1432-0568
    Keywords: Decidua ; Involution ; Electron microscopy ; Mouse
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Involution of the antimesometrial decidua was analysed by electron microscopy on days 9, 10 and 11 of pregnancy in the mouse. During this period, the width of the antimesometrial decidua decreases considerably. Involution begins in the decidual cells situated closest to the embryo (internal decidua) and proceeds towards the myometrium. The cells of the internal decidua showed signs of deterioration characterized by accumulation of clumps of chromatin in the nuclei and dilation of the perinuclear cisterna and endoplasmic reticulum cisternae. Autophagosomes and heterophagosomes accumulated in the cytoplasm of these cells. Cells particularly strongly affected became spherical and were devoid of their plasma membrane. Some cells near the trophoblast as well as the mature decidual cells situated farther from the embryo showed a normal morphology. The trophoblastic cells established close contact with healthy decidual cells and engulfed fragments of disorganized decidual cells. It is suggested that the death of decidual cells is a type of programmed cell death and that it is not due to a direct lytic action by the trophoblast.
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  • 11
    Electronic Resource
    Electronic Resource
    Springer
    Archives of dermatological research 279 (1987), S. S30 
    ISSN: 1432-069X
    Keywords: Cicatricial pemphigoid ; Vegetating lesions ; Immunopathology ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A case with widespread vegetating-pustular skin lesions, oral erosions, ulcerations and scarring, and conjunctival synechiae is reported. Clinically, histopathologically, and by immunofluorescence and electron microscopy this patient combined the features of pemphigoid vegetans, as described by Winkelmann and Su, and the mucocutaneous type of cicatricial pemphigoid. This observation suggests that a third subset of cicatricial pemphigoid can now be added to the two existing ones, the mucocutaneous and Brunsting-Perry types, and the designation vegetating cicatricial pemphigoid is proposed for this heretofore undescribed condition.
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  • 12
    Electronic Resource
    Electronic Resource
    Springer
    Acta neuropathologica 73 (1987), S. 370-378 
    ISSN: 1432-0533
    Keywords: Electron microscopy ; Factor VIII ; Glial fibrillary acidic protein ; Hemangioblastoma ; Tissue culture
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The histogenesis of stromal cells in capillary hemangioblastoma has been the subject of debate. The light and electron microscopic studies of hemangioblastomas presented here showed pericytic and leiomyoblastic features in stromal cells. Cells cultured by the monolayer method showed similar features to those of the original tumors. Immunohistochemical studies for glial fibrillary acidic protein and factor VIII/von Willebrand factor indicated that stromal cells were antigenically distinct from astrocytes and endothelial cells. These findings suggest that stromal cells are closely related to pericytes and smooth muscle cells, and support Rhodin's speculation that pericytes serve as a precursor to smooth muscle cells.
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  • 13
    ISSN: 1432-0533
    Keywords: Hypoglycemia ; Rat striatum ; Glutamate ; Excitotoxic nerve cell injury ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In rat striatum severe hypoglycemia causes an irreversible nerve cell injury, which does not become manifest until during the post-insult recovery period. This injury can be ameliorated by lesions of the glutamatergic cortico-striatal pathway, which suggests that an “excitotoxic” effect mediated by the glutamatergic input is the likely cause of the posthypoglycemic nerve cell destruction. In this paper we further characterize the protective effect of abolishing the glutamatergic innervation to striatum at the ultrastructural level. Two weeks after a unilateral cortical ablation rats were subjected to 30 min of severe hypoglycemia with isoelectric EEG and killed either immediately after the insult or following 60 min of recovery induced by restoring the blood glucose levels. Immediately after the hypoglycemic insult the structure of striatum was similar on both sides (except for the changes attributable to the ablation); i.e., the neurons and their dendrites had pale cytoplasm with condensed mitochondria, sparse RER and pinpoint ribosomes. After 60 min restitution numerous striatal neurons on the non-protected, non-ablated side had turned variably dark and condensed, whereas under-neath the ablation they remained similar as immediately after hypoglycemia. This sequence indicates that the most likely cause of nerve cell destruction on the non-protected side is the “excitotoxic” effect mediated by the glutamatergic innervation, which is superimposed on the action of the hypoglycemic insultper se. Furthermore, the primary condensation of neurons and their dendrites indicate existence of another type of acute “excitotoxic” nerve cell injury which differs from the previously described injury characterized by neuronal swelling.
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  • 14
    Electronic Resource
    Electronic Resource
    Springer
    Acta neuropathologica 75 (1987), S. 131-139 
    ISSN: 1432-0533
    Keywords: Cerebral ischemia ; Hyperglycemia ; Substantia nigra ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Preischemic hyperglycemia induced by feeding or glucose infusion worsens the brain damage and the clinical outcome following ischemia of a given duration and density, and characteristically causes postischemic seizure activity. Light microscopy has previously showed that, in the rat, transient hyperglycemic ischemia induced by bilateral carotid occlusion in combination with arterial hypotension causes a uni- or bilateral lesion in the pars reticulata of the substantia nigra. Since this region has a central role in preventing seizure discharges the present study was carried out to determine the ultrastructural characteristics of this lesion. In rats with 10 min of transient hyperglycemic ischemia followed by recirculation for 1 to 18 h, the pars reticulata of the substantia nigra showed signs of status spongiosus, as well as extensive nerve cell alterations. These changes were observed after all recovery periods studied. The spongiotic appearance was mainly caused by swelling of dendrites and, to a lesser degree, by astrocytic swelling. The dendrites were expanded at all recovery times but the severity increased during the later periods of recirculation. These swollen dendrites contained severely expanded mitochondrias and endoplasmic reticulum. The cytoskeletal elements showed disordered lining of microtubules. Two major types of nerve cell alterations were present: a “pale” and a “dark” variety. The pale type was the most frequent cell alteration. It occurred in all experimental groups and at all time points. Redistribution of the nuclear chromatin and of cytoplasmic organelles as well as swelling of the same type as in the dendrites were the essential changes. The dark neurons were much fewer in number and occupied a peripheral position in the pars reticulata. Astrocytic foot processes appeared to be dilated around the dark neurons. Swelling of astrocyte processes was most pronounced in the 1 h recovery animals. Both types of neurons showed severe mitochondrial alterations of the type observed in dendrites. Occasionally, mitochondrial alterations were found in astrocytic processes as well. Blood vessel alterations were lacking. Previous studies have shown that in this model of ischemia the substantia nigra has a relatively well-preserved blood perfusion. In view of this the extensive histopathological lesions are surprising. We speculate that the lesions primarily involve excitotoxic damage to dendrites, with pronounced lactic acidosis playing a contributory role in causing axonal and glial pathology as well.
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  • 15
    Electronic Resource
    Electronic Resource
    Springer
    Anatomy and embryology 176 (1987), S. 525-530 
    ISSN: 1432-0568
    Keywords: Placenta ; Guinea pig ; Labyrinth ; Syncytiotrophoblast ; Tracers ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The permeability of the materno-fetal barrier in the chorioallantoic placenta was studied in guinea pigs with gestation at term applying a variety of electron-opaque tracers via maternal circulation. None of the tracers tested was seen permeating the syncytiotrophoblast in the materno-fetal direction up to a 20 min interval when the fine structure of the placenta was satisfactorily preserved. The lanthanum chloride, cationized ferritin and horseradish peroxidase bound to the trophoblast surface, apparently due to electrostatic forces more than to specific receptors, and no uptake of these probes was detected in the cytoplasm. Albumin-colloidal gold complex, also used as a tracer, yielded similar results. As reported in other species with more complex syncytiotrophoblastic organization, this layer investing maternal lacunae is a highly selective permability barrier.
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  • 16
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    Springer
    Acta neuropathologica 74 (1987), S. 169-178 
    ISSN: 1432-0533
    Keywords: Cerebral gangliocytoma ; Parieto-frontal lobe ; Intracytoplasmic inclusion bodies ; No synapse ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary We report a case of cerebral gangliocytoma (GC) with a variety of unusual structures in the tumor cells. Light microscopically, the tumor consisted of typical ganglion cells, atypical cells which has argyrophilic granules in the cytoplasm, and a few astrocytes. Electron microscopically, the tumor cells showed typical gangliocytic features, which had abundant rough endoplasmic reticula, ribosomes and cored vesicles of 90–150 nm diameter, a few 50-nm-diametered non-cored vesicles, and other common organelles in their cytoplasm. Furthermore, neoplastic ganglion cells contained a variety of abnormal structures, including membranous cytoplasmic bodies (MCB), Zebra bodies (ZB), tubular structures, branched tubular structures (BTS), concentrical laminated bodies and curvilinear bodies (CB). The MCB, ZB and CB resembled those in GM2 gangliosidosis (GMG), and the BTS that in infantile neuroaxonal dystrophy (INAD). Although the significance of these inclusions is still unknown, it is considered that some common mechanism might play a role in the metabolism of both neoplastic neuronal cells and degenerating neurons (GMG and INAD). Synapses could not be observed anywhere despite complete neuronal differentiation of many tumor cells.
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  • 17
    Electronic Resource
    Electronic Resource
    Springer
    Anatomy and embryology 176 (1987), S. 145-154 
    ISSN: 1432-0568
    Keywords: Neurological mutant mice ; ‘Purkinje cell degeneration’ (pcd) ; Weaver ; Neural transplants ; Cerebellum ; Light microscopy ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Embryonic cerebellar grafts from genetically normal donors were implanted into the cerebellomedullary cistern of adult ‘Purkinje cell degeneration’ (pcd) and weaver mutant mice, which are respectively characterized by the selective loss of Purkinje and granule cells. Grafts placed into both mutant recipients exhibited a layered cellular organization reminiscent of the normal cerebellar cortex. Molecular, Purkinje, and granule cell layers were identifiable. Grafted Purkinje cells displayed characteristic cytological features, such as hypolemmal cisterns in association with mitochondria in the perikaryon, and lamellar structures in their axons. The cytological features of granule cell somata in the grafts appeared similar to those of mature granule cells. Electron microscopic examination of the molecular layer of the grafts revealed the presence of parallel fibers, which were not oriented in a parallel fashion; axon terminals of such fibers were often presynaptic to dendritic spines. The number of parallel fibers was markedly reduced in grafts implanted into both mutants compared to the normal cerebellar cortex; however, this phenomenon is commonly seen in cerebellum in tissue culture and in cerebellar transplants into normal hosts. It is concluded, therefore, that the environment of the mutant hosts does not affect the survival of Purkinje or granule cells and that transplantation of solid cerebellar grafts in the neurological mutants studied does not seem to pose any apparent limitations beyond those inherent to the process of cerebellar growth and differentiation outside its normal environment.
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  • 18
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    Springer
    Acta neurochirurgica 88 (1987), S. 142-146 
    ISSN: 0942-0940
    Keywords: Electron microscopy ; immunohistochemistry ; pituitary ; rhabdomyosarcoma
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Intracranial extension of rhabdomyosarcoma from the face, nasopharynx or middle ear is rare. A 16-year-old boy presented with deterioration of vision and headache. CT scan revealed a soft tissue mass occupying the sphenoid and ethmoid sinuses, extending to the suprasellar fossa and impinging on the optic chiasm. The tumour, mimicking pituitary carcinoma, was removed by transsphenoidal craniotomy. Morphologic studies, including immunohistochemistry and electron microscopy, revealed that the tumour was a rhabdomyosarcoma. This case stresses the value of immunohistochemical and ultrastructural studies in the diagnosis of tumours occurring in the region of the sella turcica. The origin of this tumour was thought to be the sphenoid or ethmoid sinus. The pituitary gland appeared intact.
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  • 19
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    Springer
    Acta neurochirurgica 85 (1987), S. 56-62 
    ISSN: 0942-0940
    Keywords: Electron microscopy ; erythropoietin ; haemangioblastoma ; immunohistochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Immunohistochemical studies for erythropoietin were carried out in six capillary haemangioblastomas, three of which were also studied by electron microscopy. The immunohistochemical studies showed that positively stained cells were scattered in the vicinity of capillaries, and that neither endothelial cells nor stromal cells were stained. In their morphology and distribution, the positively stained cells were identical to mast cells as observed by electron microscopy. In one case, erythropoietin was demonstrated in the cyst fluid of the tumour. These findings suggest that mast cells with abundant secreting granules in haemangioblastomas are capable of producing erythropoietin.
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  • 20
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    Springer
    Acta neuropathologica 72 (1987), S. 341-348 
    ISSN: 1432-0533
    Keywords: Carbon disulphide neuropathy ; Pacinian corpuscles ; Denervation and reinnervation ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Adult Wistar rats were exposed to carbon disulphide vapours at a concentration of 2.4 mg/l of air for 5 days a week (6 h a day), and the ultrastructure of Pacinian corpuscles and their nerve supply was investigated after 6 months of exposure. Both degenerative and regenerative changes were observed in sensory axons and the corpuscles. In a sample of corpuscles examined, 30% were denervated and about 60% showed clear signs of reinnervation. Some of the reinnervated corpuscles were supplied by unmyelinated axons. In others, one to three myelinated axons were already found at the nerve entry. The axons branched and formed three to eight terminals in the inner core. Due to continuous intoxication, most regenerated terminals were again undergoing degeneration. In peripheral nerves, the evidence of axonal regeneration has been reported in various toxic distal axonopathies. However, the reinnervation of Pacinian corpuscles has not been described before. It can be expected that reinnervation of Pacinian corpuscles and other end-organs also occurs in other axonopathies, if not during continuous poisoning, then at least after its cessation.
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  • 21
    ISSN: 1432-0983
    Keywords: Electron microscopy ; Replicative intermediates
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Some physicochemical properties of the mitochondrial DNAs (mtDNA) from plants of flax, broad bean and mung bean, and from tissue culture cells of jimson weed, soybean, petunia and tobacco were determined. Circular molecules were observed in electron microscope preparations of each mtDNA. In soybean, petunia, broad bean and mung bean mtDNAs, the circular molecules had a continuous distribution of lengths (ranges between 1 to 36 kb, and 1 to 126 kb), heavily skewed toward smaller molecules. Eighty-six percent of the flax circular molecules were from 27 to 54 kb in size, and 78% of the jimson weed circular molecules were from 4 to 15 kb. Replicative forms of 1.2–1.6 kb circular molecules were observed in electron microscope preparations of broad bean mtDNA.
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  • 22
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    Archives of dermatological research 279 (1987), S. 167-172 
    ISSN: 1432-069X
    Keywords: Morphometry ; Electron microscopy ; Cytological atypia ; Nevus cells ; Melanoma cells
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Cytological atypia, revealed in the course of routine light microscopy, is considered a valuable indicator of malignancy in melanocytic lesions. A clear definition of the term cytological atypia, however, is lacking. Therefore, by morphometric analysis of ultrathin sections of 11 malignant melanomas (7 invasive, 3 in situ, and 1 lentigo maligna melanoma) and 10 compound nevi, we evaluated the discriminating power of the various facets of cytological atypia, i. e., nuclear area, area of the nucleolus, area of the total cell, and nuclear irregularity. In each case, at least 50 intraepidermal melanocytic cells were examined. The two-sided U-test showed significant differences between intraepidermal nevus and melanoma cells, with regard to the mean values (x) and standard deviations (s) of the nuclear area (x and s, p=0.00011), area of the nucleolus (x, p=0.00043; s, p=0.00011), and area of the total cell (x, p=0.00011; s, p=0.00093). However, only the mean values and standard deviations of the nuclear area allowed a clear distinction in each individual case. The area of the nucleus can be estimated in the course of routine histology. We therefore think that the size and variation of the nuclear area should be considered in the histological differential diagnosis between malignant melanomas and benign nevi.
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  • 23
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    Archives of dermatological research 279 (1987), S. 308-314 
    ISSN: 1432-069X
    Keywords: Congenital cutis laxa ; Collagen synthesis ; Electron microscopy ; Morphometry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A case of congenital cutis laxa (CCL) of unclear mode of inheritance associated with multiple pulmonary artery branch stenosis was extensively investigated to assess possible correlations between clinical, ultrastructural, and biochemical features. Light microscopy revealed that elastic fibers were absent in the papillary dermis, while hypoplastic elsewhere. Transmission electron microscopy showed a poor elastin matrix content in some elastic fibers, variable diameters of collagen fibrils, and abundant glycogen granules in most dermal cells. Measurement of collagen fibril diameters, using an image analyzer, was carried out in the patient and two age- and site-matched controls. A biomodal distribution was found in the upper reticular dermis of the patient. In vitro analysis of collagen in skin fibroblast cultures of the patient showed increased collagen synthesis with a balanced production of type I and type III procollagens. Our study confirms that CCL represents a disorder both of collagen and elastic connective tissue.
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  • 24
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    Experimental brain research 66 (1987), S. 175-184 
    ISSN: 1432-1106
    Keywords: Dorsal column nuclei ; Gracile nucleus ; Inferior olive ; Dorsal accessory olive ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary This study examined the termination pattern within the dorsal accessory subdivision of the cat inferior olive of axons arising from the gracile nucleus. The gracile terminals were labeled by anterograde transport of wheat germ agglutinin complexed to horseradish peroxidase and visualized with tetramethyl benzidine. Gracile terminals were found to contain round synaptic vesicles and form asymmetric synaptic contacts. Of particular interest was the finding that gracile axons, like axons from the spinal cord, terminate primarily outside of synaptic glomeruli. Yet most of the gracile terminals did not synapse on isolated dendritic elements. Rather, the majority contacted distal dendrites which directly contacted other dendritic elements, forming simple complexes termed dendritic thickets. Typically the dendritic thickets were composed of two or three dendrites that received input from more than one round vesicle-containing synaptic terminal. Only one terminal per thicket was labeled by injections in the gracile nucleus. This clustering of pre-and postsynaptic elements within the thickets provides opportunities for many of the same interactions allowed by synaptic glomeruli, in particular divergence and convergence of information.
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  • 25
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    Experimental brain research 67 (1987), S. 380-390 
    ISSN: 1432-1106
    Keywords: Adrenal medulla ; Periaqueductal gray ; Neural implants ; Analgesia ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Recent findings in our laboratory indicate that adrenal medullary grafts produce significant alterations in pain sensitivity. Electron microscopic studies were undertaken to correlate these behavioral changes with the neural interactions of the host and graft tissue in the periaqueductal gray. A striking change found 8 weeks after transplantation is that pronounced myelination has taken place both in the graft and in the host tissue. The new myelin formation in the graft has the typical appearance of PNS myelination and, in the host the appearance of CNS myelination. The endothelial cells of the capillaries in the grafted tissue are attenuated and fenestrated in contrast to those of the surrounding parenchymal tissue of the host. By 8 weeks, the graft becomes heavily encapsulated with collagen, while the host CNS tissue develops layers of glial processes outlining the graft. However, collagen and glial layers apparently do not form an absolute barrier to either cellular or humoral interaction between the host and graft tissue. Chromaffin cells can be found protruding into the host CNS tissue and sometimes forming synapses with presumably the host neuronal processes. Grafted chromaffin cells may participate as both postsynaptic and, less often, as presynaptic components of synaptic junctions. The behavioral relevance of these synaptic contacts is unclear, since similar implants of adrenal medullary tissue into the dorsal spinal cord subarachnoid space, which also induce potent analgesia, do not contain synapses. Thus, it is more likely that behavioral changes are brought about by diffusion of neuroactive substances from grafted chromaffin cells to host receptors.
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  • 26
    ISSN: 1432-1106
    Keywords: Ventral mesencephalic grafts ; Electron microscopy ; Afferent synapses ; Tyrosine hydroxylase immunocytochemistry ; Dopaminergic neurons ; Dopaminergic boutons
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In adult rats with a unilateral 6-hydroxydopamine-induced lesion of the nigrostriatal dopamine pathway, grafts of embryonic ventral mesencephalon can establish extensive efferent connections with the previously denervated host neostriatum and can compensate for motor and sensorimotor asymmetries induced by the lesion. The object of this study was to examine the afferent synaptic inputs to grafted dopaminergic neurons, implanted into a cortical cavity overlying the previously denervated caudate-putamen, using electron microscopic immunocytochemistry. The dopaminergic neurons of the grafts in the same animals had previously been shown to re-innervate the host neostriatum, to form synaptic connections therein and to attenuate the lesion-induced motor asymmetry that occured in response to amphetamine (Freund et al. 1985). In the light microscope, the grafts were found to contain numerous tyrosine hydroxylase-immunoreactive perikarya, dendrites, axons and axonal swellings which had distinct distributions. In addition axons and axonal swellings that were immunoreactive for either substance P or glutamate decarboxylase were present. Electron microscopic analysis of the boutons contacting tyrosine hydroxylase-immunoreactive neurons in the grafts revealed the presence of at least five distinct types of afferent synaptic boutons based on their immunochemistry, morphology, or types of membrane specialization. One type was itself immunoreactive for tyrosine hydroxylase; such synapses are extremely rare in the intact substantia nigra, none were found in the contralateral substantia nigrae or the substantia nigra of a control rat. Three of the remaining types had ultrastructural features that were similar to synaptic terminals that were immunoreactive for substance P or glutamate decarboxylase. These synapses were similar to the types of synapses found contacting dopaminergic neurons in the substantia nigra contralateral to the graft or the substantia nigra of a control rat. The results demonstrate that, in the absence of the normal extrinsic afferent inputs, the intracortical mesencephalic grafts have a well-developed local synaptic circuitry. It is suggested that local circuit regulation of dopaminergic neurons within the graft may, at least in part, be responsible for the maintenance of a normal or close to normal functional activity.
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  • 27
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    Archives of dermatological research 279 (1987), S. 270-272 
    ISSN: 1432-069X
    Keywords: Atopic eczema ; Hyperlinear palms ; Autosomal dominant ichthyosis vulgaris ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
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  • 28
    ISSN: 1432-2013
    Keywords: Sugar transport ; Electron microscopy ; Chicken cecum and jejunum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract We have investigated the possible relation between the phloridzin-sensitive influx of α-methyl-D-glucoside (concentration 5 mmol/l) and the brush border surface area, in chicken isolated enterocytes. The intestinal regions studied were: jejunum and proximal cecum (both with high affinity sugar transport sites), medial cecum (with a low affinity transport system) and distal cecum (which lacks any transport ability). Cell apical surface measured by electron microscopy gave the following results; jejunal cells (0.41 μm2) 〉proximal cecal cells (0.23 μm2)〉medial cecal cells (0.15 μm2)=distal cecal cells (0.14 μm2). This parameter is mainly determined by the length of microvilli. Sugar influx studies showed that the concentration of the substrate in cell water (in mmol/l) was jejunum (7.1)〉proximal cecum (2.9) 〉medial cecum (1.7)〉distal cecum (not different from zero). The decline in influx rate from proximal to distal cecum may be explained both by changes in surface and by the different carriers involved (differentK m). Results of sugar concentration in the distal cecal cells do not correlate with the other segments studied since the substrate enters in these cells by a passive process. It is concluded that the degree of development of microvilli should be taken into account when estimating nutrient transport rates in different intestinal segments.
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  • 29
    ISSN: 1437-160X
    Keywords: Chondrocalcinosis ; Calcium pyrophosphate dihydrate crystals ; Polymorphonuclear leukocyte ; Articular cartilage ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Electron microscopy was used to investigate the characteristics of calcium pyrophosphate dihydrate (CPPD) crystals in chondrocalcinosis (pseudogout syndrome). Crystals in midzone cartilage were frequently seen adjacent to chondrocytes. Great variation in crystal size and shape was observed. Most of the pyrophosphate crystals that had been phagocytosed by polymorphonuclear leukocytes of synovial fluid from patients with acute pseudogout were small (≦1 μm), indicating that small crystals can cause intense inflammation. Large numbers of polymorphonuclear leukocytes became attached to the eroded articular surface and phagocytosed microcrystals. Interaction of polymorphonuclear leukocytes with CPPD crystals in the superficial region of articular cartilage may stimulate the release of inflammatory mediators.
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  • 30
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    Colloid & polymer science 265 (1987), S. 855-859 
    ISSN: 1435-1536
    Keywords: Electron microscopy ; polyethylenemelt ; fine structure ; artifact
    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 There are still two opinions on the fine structure of polymer melts and glasses: (a) that the structure is similarly homogeneous to that in lower molecular weight materials and (b) that the structure shows larger short-range order regions (2–20 nm), which consist of bundeled segments of the chain molecules. Whereas opinion a relies more on indirect methods of investigation, opinion b is based mainly on fine granular structures which become visible in electron microscope investigations of surfaces of glassy solidified polymers. Such a fine structure can now be observed directly in a polyethylene melt. However, the structure is exposed as an artifact, so opinion a is supported.
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  • 31
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    Journal of cancer research and clinical oncology 113 (1987), S. 392-399 
    ISSN: 1432-1335
    Keywords: Paget's disease of bone ; Osteosarcoma ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The authors report 12 cases (8 men and 4 women) of sarcomatous degeneration in Paget's bone disease, with an average age of 72.3 years. Sarcomatous degeneration occurred often in polyostotic Paget's disease, and osteitis deformans was seen in 4 cases. Femur and pelvis were the most affected bones. Pain was a constant feature, whereas tumefaction and fracture were less common. Osteolytic lesions were more frequent than condensed or mixed lesions and radiological signs of malignancy were usually found. Seven cases were histologically clasiified as osteogenic sarcoma and 3 cases as fibrosarcoma. Electron microscopy was performed on 2 osteogenic sarcomas and in 1 case revealed microcylindrical inclusion in Pagetic osteoclasts and in multinucleated giant tumor cells, but none in mononucleated tumor cells. The average survival time for the patients in this study was only 4.5 months.
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  • 32
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    European archives of oto-rhino-laryngology and head & neck 243 (1987), S. 361-365 
    ISSN: 1434-4726
    Keywords: Human inner ear ; Congenital anomalies ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary We performed light and electron microscopic studies on the temporal bones of a patient with genetic aplastic deafness, in which the right ear had a Mondini-type defect and the left ear a Michel-type anomaly. The round window of each ear was absent. The stapedial foot plate of the right ear was depressed at its central part and was covered by thin membrane. The course of the internal auditory meatus of the left ear was deviated ventrally. There was total aplasia of the cochlea in the left ear, while that of the right ear showed only three-quarters of a turn. In this ear, three sites of spherical bulging were found and were believed to represent outer hair cells. Other structures of the normal cochlear duct were not present. The modiolus of the left ear was round and dome-shaped, contained sparse nerve fibers and a primitive spiral ganglion. The saccule, utricle and semicircular canals of each ear were missing, so that a common cavity of the vestibular system was present. Several otoliths could be seen under the surface of the membrane covering the common cavity. No sensory cells or their related tissues could be found in either ear.
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  • 33
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    European archives of oto-rhino-laryngology and head & neck 243 (1987), S. 382-386 
    ISSN: 1434-4726
    Keywords: Experimental tympanosclerosis ; Calcium antagonists ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The effect of calcium antagonists in experimental tympanosclerosis following infection with Streptococcus pyogenes and vitamin D3 intoxication has been analyzed in a rat animal model. Compared with untreated animals, calcium antagonists exert a positive effect on the degenerative process and on secondary calcification in the subepithelial layer. This effect could be substantiated planimetrically.
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  • 34
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    European archives of oto-rhino-laryngology and head & neck 244 (1987), S. 180-184 
    ISSN: 1434-4726
    Keywords: Localized laryngeal amyloidosis ; Light microscopy ; Electron microscopy ; Immunohistochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary We performed light and electron microscopic studies in a case of localized supraglottic laryngeal amyloidosis involving a 55-year-old woman. Tissue specimens were stained with hematoxylin and eosin, and alkaline Congo red with or without permanganate (KMnO4) treatment, and were also examined with peroxidase-antiperoxidase immunohistochemistry. Biopsy specimens from the epiglottis showed diffuse replacement of the subepithelial region by amyloid, which showed a typical green birefringence under polarized light. Tissue affinity for Congo red was persistent after the KMnO4 treatment. However, the tissue sections showed a positive reaction only to the anti-P component antibody. Electron microscopic studies revealed some disorders of the plasma cells, suggesting that these cells play an important role in focal production of amyloid fibrils.
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  • 35
    ISSN: 1432-0533
    Keywords: Herpes simplex virus type 2 ; Genital infection ; Avidin-Biotin Method ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Mice were infected by the vaginal route with the MS strain of herpes simplex virus type 2 (HSV-2). Serial vaginal cultures were used to confirm infection and to select mice for this study. Two mice were killed by perfusion on days 2–6 post infection (p.i.) and lumbar and sacral cord with cauda were fixed and embedded for electron microscopy. Semithin Epon-sections were stained for viral antigen using a rabbit anti-HSV-2 antiserum and the Avidin-Biotin (ABC) method. Thin sections from antigen-positive blocks were examined by electron microscopy, and the number and types of infected cells detected by these two methods were compared. A good correlation was found between detection of infected cells by these methods. Infected cells included neurons of dorsal root ganglia and spinal cord, satellite cells of dorsal root ganglia, non-myelinating Schwann cells, astrocytes, oligodendrocytes and arachnoidal cells. Infected cells were first detected in the cauda on day 3 p.i. and in the spinal cord on day 5 p.i. The temporal and spatial distribution of infected cells was consistent with neural spread to and within the CNS. The pathological lesions showed a good correlation with the distribution and number of infected cells and are probably due to a direct virus effect. The similar sensitivity of the Epon-ABC method to electron microscopy in detecting infected cells indicates that this method may have useful applications in both experimental and diagnostic work.
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  • 36
    ISSN: 1432-0533
    Keywords: Cerebral calcification ; Fahr's disease ; Electron microscopy ; Histochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A case of idiopathic nonarteriosclerotic cerebral calcification was studied post mortem by histochemical and scanning and transmission electron microscopic methods. Calcification was found bilaterally in the basal ganglia, cerebral cortex, granular layer and white matter of the cerebellum. Histochemical examination revealed that deposits were composed of a mixture of glycoproteins, mucopolysaccharides, calcium salts and iron. Transmission electron microscopy revealed minute deposits mainly in the cytoplasm of adventitial cells of blood vessels and sometimes in the cytoplasmic processes of glial cells. Scanning electron microscopy showed that some of the spherical and hemispherical bodies, which were formed in the adventitial cells of blood vessels, were connected with filamentous cytoplasmic processes of surrounding cells. Small uncalcified deposits occurring in the cytoplasm of the adventitial cells had subsequently had minerals deposited in them. Some kind of impairment of the pericytes may play an important role at the onset of this disease.
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  • 37
    ISSN: 1432-0878
    Keywords: Mammary gland ; Tissue culture ; Collagen gel ; Electron microscopy ; Human
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Fragments of human breast epithelium, devoid of all stromal and basal lamina components, which maintain their in vivo topological organisation can be cultured for up to 28 days within a reconstituted rat-tail-derived collagen matrix. These organoids initially undergo a loss of structural and 3-dimensional organisation, typified by loss of lumina formed by epithelial cells, and myosin from myoepithelial cells. Their subsequent reorganisation is dependent on the presence of serum, insulin, hydrocortisone, and cholera toxin in tissue culture medium. After this preliminary phase, a reduction in the concentration of serum, insulin, hydrocortisone, and cholera toxin is necessary to allow the structural differentiation of epithelial and myoepithelial cells. The myoepithelial cells also regain their ability to produce the basal lamina component laminin. The use of bovine-dermal collagen as the matrix, rather than rat-tail-derived collagen is shown to result in more stable organisation and differentiation of the organoids. The successful use of single-cell pellets (derived by trypsinisation of the organoids) in place of organoids in such cultures illustrates that there is no requirement for pre-existing cell/ cell contact or topological organisation of cells prior to embedding within the collagen matrix.
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  • 38
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    Cell & tissue research 247 (1987), S. 457-459 
    ISSN: 1432-0878
    Keywords: Vomeronasal glands ; Autonomic innervation ; Electron microscopy ; Mouse
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The morphological evidence for a direct autonomic innervation of the mouse vomeronasal glands is presented. Axonal varicosities containing a few densecore vesicles and numerous clear vesicles (36–60 nm in diameter) make synaptic contacts with the secretory cells at the base of the glandular acini. The axonal presynaptic membrane is associated with a distinct dense material and it is separated from the secretory cell by a synaptic cleft of about 12–14 nm. At the postsynaptical level, coated vesicles can be found. Additional postsynaptical specializations have not been observed.
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  • 39
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    Cell & tissue research 248 (1987), S. 393-398 
    ISSN: 1432-0878
    Keywords: Adrenaline ; Phenylethanolamine-N-methyl transferase ; Immunocytochemistry ; Electron microscopy ; Central nervous system ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The fine structure of adrenergic axon terminals was examined in the paraventricular nucleus of the thalamus (PNT) and in the hypothalamic arcuate nucleus-median eminence (ARC-ME) complex by use of phenylethanolamine-N-methyl transferase (PNMT) immunocytochemistry. In the PNT, immunoreactive terminals formed a dense and well-circumscribed plexus. In the ARC, labeled varicosities were less numerous and more evenly distributed. In the ME, they were scarce and confined to the inner zone. In all these areas, the diameter of immunoreactive varicosities ranged between 0.2 and 1.3 μm; in the ME and in the transitional zone between the ARC and the ME, a population of larger boutons (〉2 μm) was also visible. All immunoreactive varicosities exhibited densely packed small, clear vesicles associated with a few large granular vesicles. In the PNT and the ARC, but not in the ME, they formed synaptic contacts with dendritic elements and were occasionally apposed to neuronal cell bodies. These axo-somatic appositions showed no junctional specializations. In the ME and transitional zone, immunoreactive terminals were frequently juxtaposed to, and occasionally established differentiated synaptic contacts with, tanycytes. These data support a transmitter role for adrenaline in the diencephalon and suggest that adrenaline plays a role in hypothalamo-hypophysiotropic regulation through interactions with neural and glial elements.
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  • 40
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    Cell & tissue research 248 (1987), S. 169-180 
    ISSN: 1432-0878
    Keywords: M-band structure ; Fibre type ; Skeletal muscle ; Cryo ultramicrotomy ; Electron microscopy ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The fine structure of the M-band in soleus (SOL) and extensor digitorum longus (EDL) muscles in newborn and four-week-old rats was studied using electron-microscopic techniques. In newborn rats, all myotubes and fibres in both muscles had an identical myofibrillar appearance. A five-line M-band pattern was seen in longitudinal sections and distinct M-bridges in cross-sections. The Z-discs were of medium width. On the other hand, in four-week-old rats, different muscle fibre types were observed on the basis of their myofibrillar pattern. In SOL two fibre types were distinguished in longitudinal sections. One had a four-line M-band pattern and very broad Z-discs, whereas the other type had five lines in the M-band and broad Z-discs. In EDL, three different myofibrillar patterns were observed. The M-bands were composed of three, four or five lines. Fibres had either thin, broad or medium Z-disc widths, respectively. In cross-sections of the SOL muscle one group of fibres showed indistinct M-bridges, whereas distinct M-bridges were seen in the other fibres and in all observed EDL muscle fibres. We conclude that initially there seems to be a single intrinsic program for M-band genesis; this program becomes modified upon the induction of functionally differentiated fibres.
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  • 41
    ISSN: 1432-0878
    Keywords: Human growth hormone-releasing factor (hGRF) ; Paraventricular nucleus ; Immunocytochemistry ; Electron microscopy ; Synapses ; Guinea pig
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary By means of a preembedding immuno-electronmicroscopic technique, a large number of nerve endings containing a substance related to human growth hormonereleasing factor (hGRF) have been demonstrated in the paraventricular nucleus of the guinea pig. They made synaptic contacts primarily with dendritic shafts: 80% of these contacts were symmetrical. The immunoprecipitate was located mainly in large granules and around small clear vesicles. These findings suggest that a peptide related to hGRF may play a role in neural communication in the paraventricular nucleus.
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  • 42
    ISSN: 1615-6102
    Keywords: Cytoskeleton ; Contractile proteins ; Lowicryl ; LR White ; Polyvinylalcohol ; Immunogold staining ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Three embedding media have been compared with respect to post-embedding immunolabeling of contractile and cytoskeletal antigens in aldehyde-fixed smooth muscle tissue: the methacrylate derivates lowicryl K4M (cured at −35 or 60°C) and LR White (cured at 0 or 60°C) and the water soluble resin, polyvinylalcohol (dried at 60°C). Measurements of intensity of labeling of ultrathin sections in the fluorescence microscope showed that five antigens (actin, myosin light chain, tropomyosin, filamin and vinculin) reacted more or less equally with their respective antibodies in all the embedding media, including those cured at 60°C. One antibody (anti-light meromyosin) reacted well only with polyvinylalcohol-embedded tissue. In contrast to the relative invariance of antibody reactivity between media clear differences in the preservation of ultrastructural integrity were observed. Embedding in polyvinylalcohol (dried at 60°C) and in Lowicryl (cured at −35°C) resulted in superior preservation as compared to Lowicryl or LR White cured at 60°C. Examples of uitrastructural immunocytochemistry with the antibodies against filamin and myosin light chain, using the immunogold staining procedure are presented: the sites of localization by these antibodies were the same with all the media tried. The relative merits of the different methods are discussed.
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  • 43
    ISSN: 1615-6102
    Keywords: Cytopathology ; Rhabdovirus ; Development ; Electron microscopy ; Cuscuta
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Electron microscopic examination ofCuscuta odorata, used for transmission trials, revealed mycoplasma-like organisms (MLO) as well as rhabdovirus-like particles, unknown toCuscuta. The virus infection is confined to certain phloem-parenchyma cells and a 1–2 cell thick layer of parenchyma cells with thickened walls surrounding the central cylinder. Virus particles, mostly bacilliform, could be detected mainly in the nucleus but also in the cytoplasm. They reach a length of 350–400 nm and a diameter of approximately 75 nm. Virus assembly takes place exclusively in the nucleus. Virus maturation occurs in membrane bound areas within the nucleus, which have no connection with the perinuclear space. Formation of nucleocapsids is always associated with a nuclear viroplasm. Envelopment of virus particles occurs in these membrane bound areas. Budding into the perinuclear space does not occur. Virus infection leads to degeneration and finally to death of the protoplast.
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  • 44
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    Protoplasma 140 (1987), S. 100-109 
    ISSN: 1615-6102
    Keywords: Actin ; Conifer ; Electron microscopy ; Picea glauca ; Somatic embryo ; Tissue culture ; Ultrastructure ; White spruce
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Somatic embryos in embryogenic callus cultures derived from Immature zygotic embryos ofPicea glauca (White spruce) were examined by light and electron microscopy. Somatic embryos consist of an embryonic region of small densely cytoplasmic cells subtended by a suspensor consisting of long highly vacuolated cells. Mitotic figures are frequent in the embryonic cells but are not observed in the suspensor. Cell divisions in the embryonic region apparently produce rows of cells which elongate to form the suspensor. The presence of abundant polysomes, coated membranes and dictyosomes in the cytoplasm of embryonic and upper suspensor cells suggests rapid growth of the embryo. In contrast the basipetal suspensor cells appear to be senescing. While only a few scattered microfilaments are present in the meristematic cells, the upper suspensor cells contain numerous bundles of longitudinally oriented microfilaments. These bundles correspond to actin cables observed in light microscope preparations stained with rhodamine labelled phalloidin and are oriented parallel to the direction of active streaming in these cells.
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  • 45
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    Child's nervous system 3 (1987), S. 74-80 
    ISSN: 1433-0350
    Keywords: Medulloblastoma ; GFAP-positivity ; Electron microscopy ; Postoperative follow-up
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Eighty-four cases of medulloblastoma were examined immunohistochemically and 12 by electron microscopy to assess differentiation in these tumors. Based upon the largest series of medulloblastoma studied to date, we demonstrated glial fibrillary acidic protein (GFAP) positivity, in 25% (21/84) of these tumors showing glial differentiation. GFAP-positive cells were seen more frequently in the desmoplastic variant of medulloblastoma (7/10). Under electron microscopy, the major part of the 12 tumors studied appeared primitive and undifferentiated. In 7 cases, groups of cells were found with primitive neuronal and/or glial features. GFAP positivity was confirmed at light microscopy level in all cases where cells showed glial differentiation in the form of glial-like filaments in cytoplasma. However, a follow-up questionnaire study of those patients who had received only surgical treatment revealed no difference in mean survival time between GFAP-positive and GFAP-negative medulloblastoma.
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  • 46
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    European archives of oto-rhino-laryngology and head & neck 244 (1987), S. 30-35 
    ISSN: 1434-4726
    Keywords: Central venous hemangioma ; Mandible ; Immunohistochemistry ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary To date, 96 cases of central hemangiomas of the jawbones have been described in the literature. Of these cases, the mandible has been more affected than the maxilla, while approximately 50% of all cases occur in the first and second decades of life. Histopathologically, cavernous and capillary types are often found, in contrast to the central venous type, which is rare. We have recently treated a 44-year-old man, who was found to have a central venous hemangioma in his mandible. Immunohistochemical studies were performed using factor-VIIIrelated antigen as well as various lectins as markers for tumor endothelial cells. Our results showed that four kinds of lectins (UEA-I, PNA, ConA, and DBA) were useful for the marker as factor-VIII-related antigen. Scanning electron microscopic findings of this tumor demonstrated that the lumina of the blood vessels were more rough, while the lining endothelial cells were more irregular when compared with those of the normal vascular system.
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  • 47
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    Cell & tissue research 247 (1987), S. 167-177 
    ISSN: 1432-0878
    Keywords: Arteriovenous anastomoses ; Autonomic innervation ; Synaptic vesicles ; Histochemistry ; Electron microscopy ; Tongue ; Dog
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The innervation of the arteriovenous anastomoses in the dog tongue has been investigated. At the lightmicroscopic level, the vessels were found to be densely supplied with adrenergic and AChE-positive nerve plexuses and less densely with the quinacrine-binding nerve plexus. At the electron-microscopic level, at least two apparently different types of axon profiles were identified: 1) Small vesicle-containing axons, characterized by many small granular vesicles, variable numbers of small clear vesicles and large granular vesicles. Storage of endogenous amines and uptake of exogenous amines into most small granular vesicles and many large granular vesicles was demonstrated. These axons stained only lightly with reaction products for AChE activity and thus seemed to be adrenergic in nature. Some axons contained numerous large granular vesicles, whose cores occasionally stained with uranyl ions; this suggests a co-localization of ATP or peptides as neurotransmitters. 2) Small granular vesicle-free axons, containing small clear vesicles and large granular vesicles in variable ratio. Most cores of these large granular vesicles were heavily stained with uranyl ions. No storage or uptake of amine into the synaptic vesicles was detected. Some axons appeared to be typically cholinergic, some, typically non-adrenergic, noncholinergic, and the rest, intermediate between the two. All axons stained heavily with reaction products for AChE activity, suggesting their cholinergic nature.
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  • 48
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    Cell & tissue research 247 (1987), S. 573-582 
    ISSN: 1432-0878
    Keywords: Seminal vesicle ; Histology ; Histochemistry ; Electron microscopy ; Physiology ; Clarias gariepinus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The seminal vesicle of the African catfish, Clarias gariepinus, consists of 36–44 fingerlike lobes built up of tubules in which a fluid is secreted containing acid polysaccharides, acid-, neutral- and basic proteins, and phospholipids. In this fluid sperm cells are stored. The seminal vesicle fluid immobilizes the sperm cells. After ejaculation, it prolongs the period of sperm activity. The seminal vesicle fluid is secreted by the epithelium lining the tubules. The tubules in the proximal part of the lobes are predominantly lined by a simple cylindrical and those of the distal part by a simple squamous epithelium. These epithelial cells contain enzymes involved in energy-liberating processes, the enzyme activites being proportional to the height of the cells. Interstitial cells between the tubules have enzyme-histochemical and ultrastructural features indicative of steroid biosynthesis. Similar characteristics are found in testicular interstitial cells. The most rostral seminal vesicle lobes and the most caudal testicular efferent tubules form a network of tubules that opens at the point where the paired parts of the sperm ducts fuse with each other. The tubules of most seminal vesicle lobes, however, form a complex system that fuses with the unpaired part of the sperm duct.
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  • 49
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    Cell & tissue research 248 (1987), S. 675-682 
    ISSN: 1432-0878
    Keywords: Molluscan muscles ; Innervation ; Chromatophores ; Cephalopods ; Electron microscopy ; Eledone cirrhosa
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Cephalopod chromatophores are made of a central pigment cell surrounded by 10 to 20 radially arranged muscle fibres under direct nervous control. Innervation of these muscle fibres was studied with anterograde cobalt fills of peripheral nerve bundles and light and electron microscopy. Individual axons branch repeatedly to innervate the muscles of chromatophores scattered over several millimeters. Axons contained in several dermal nerves converge to innervate the same chromatophores. Among the chromaophores, axons were found running either singly or in small bundles, often accompanied by sheath cells. Single chromatophore muscles were innervated by at least one axon running across or along its length. Since nerves terminating on chromatophore muscles are very rare, neuromuscular contact seems to be made “en passant”. Varicosities of the axons apposed to the muscles are thought to be presynaptic sites. However, morphological differentiations of the pre-or post-synaptic membranes were not visible. Two types of innervating processes were found containing either electron-clear or a mixture of electron-clear and dark-core synaptic vesicles.
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  • 50
    ISSN: 1432-0878
    Keywords: Microtubules ; Terminal web ; Small intestine ; Electron microscopy ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The terminal web (TW) region of mature absorptive cells in the small intestine of the rat contains an elaborate cytoskeleton which supports the apical microvillus membrane. In studies regarding the structural organization of the cytoskeleton and associated proteins in the small intestine, microtubules have not been mentioned as components of the TW. By transmission electron microscopy of conventional resin-embedded sections of rat small intestine, we observe many microtubule profiles in the TW of mature absorptive cells. These microtubules are found in various orientations, although most course parallel to the long axis of the cell, and many microtubule profiles are seen in close association with smooth-surfaced vesicles.
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  • 51
    ISSN: 1432-0878
    Keywords: Alpha-bungarotoxin ; Autoradiography ; Cholinergic receptors ; Electron microscopy ; Suprachiasmatic nucleus ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The distribution of (125I) alpha bungarotoxin (α-BTX) binding sites in the suprachiasmatic nucleus (SCN) of the adult female rat was examined by electron-microscopic autoradiography. The ultrastructural distribution of silver grains was analysed by line source, direct point count, and 50% probability circle methods. Real grain distribution was significantly different from that of randomly generated hypothetical grains. Line source analysis demonstrated two populations of sources: one associated with membranes, and one inside neuronal structures. Probability circle analysis of shared grains indicated that membrane-bound-radioactive sources were mainly asssociated with axo-dendritic appositions. Only a small proportion of labeled neuronal interfaces exhibited synaptic differentiations in the plane of section. However, the compartment containing synaptic terminals was the most enriched when comparing real to hypothetical grains. Probability circle analysis of exclusive grains demonstrated that sources that were not associated with neuronal plasma membranes were likely to be within nerve cell bodies and dendrites. It is concluded that the majority of specifically labeled α-BTX binding sites in the SCN is membrane bound, and may be associated with axodendritic synaptic transmission. The presence of a significant proportion of the label in the soma and dendrites of suprachiasmatic neurons 24 h after ventricular infusion suggests that some of the labeled binding sites (junctional or nonjunctional) may be internalized within these two compartments.
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  • 52
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Starting from (+)-5β-hydroxycyclopenten-2-yl-1β-acetic acid γ-lactone (1), (+)-1β-methoxycarbonylmethyl-2β, 3β-(p-nitrobenzylidene)-dioxycyclopentan-5-one (7) was prepared within 4 steps. Subsequent cleavage of the latter gives (-)-3β-hydroxy-1-methoxy-carbonylmethylcyclopent-1-en-5-one (8a). Hydroxylation of the lactone (1) was found to give (+)-2β,3β,5β-trihydroxycyclopentyl-1β-acetic acid γ-lactone (2a) with cis-oriented hydroxy groups in respect to the lactone ring. No formation of the trans-isomer, as has been reported earlier [4], was observed.
    Additional Material: 1 Ill.
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  • 53
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    Journal für Praktische Chemie/Chemiker-Zeitung 329 (1987), S. 337-342 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 4 Tab.
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  • 54
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    Journal für Praktische Chemie/Chemiker-Zeitung 329 (1987), S. 343-348 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: 3-Substituted 4H-Pyrazolo[5,1-c][1,4]benzoxazines by Intramolecular Nitrile Imine Addition
    Additional Material: 3 Tab.
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  • 55
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    Journal für Praktische Chemie/Chemiker-Zeitung 329 (1987), S. 348-348 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
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  • 56
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    Journal für Praktische Chemie/Chemiker-Zeitung 329 (1987), S. 359-364 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 1 Tab.
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  • 57
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    Journal für Praktische Chemie/Chemiker-Zeitung 329 (1987), S. 365-373 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Influence of Lewis Acids on the Absorption Behaviour of Substituted Metallotetraazaporphins
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  • 58
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    Journal für Praktische Chemie/Chemiker-Zeitung 329 (1987) 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
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  • 59
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    Journal für Praktische Chemie/Chemiker-Zeitung 329 (1987), S. 391-399 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Carbon-13 N.M.R. Studies on 4-Amino-2,6-dialkyl Pyrimidines and Their Sulfonamide DerivativesCarbon-13 n.m.r. studies on 4-amino-2,4-dialkyl pyrimidines and their sulfonamide derivatives have shown that the known additivity rules for the assignment of signals are not valid. The reason is a tautomerism as demonstrated by changes of the chemical shifts of the alkyl groups. The electronic influence of substituents at the amino group on the alkyl C-atoms are neglegible compared to changes due to tautomerism.
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  • 60
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The aldol reaction of suitably substituted cyclopentane carbaldehydes (1a-c, 4) with 2-heptanone affords β-hydroxy ketones (2a-c, 5) in yields up to 60%. These aldolization products can be dehydrated to known prostaglandin intermediates. Due to the difficulty to convert β,δ-dihydroxy ketones selectively into α,β-unsaturated δ-hydroxy ketones this reaction sequence for the construction of the (E)-3-oxooct-1-enyl side chain of prostaglandins seems to be especially advantageous for the synthesis of 11-deoxy-prostaglandins.
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  • 61
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    Journal für Praktische Chemie/Chemiker-Zeitung 329 (1987), S. 408-408 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
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  • 62
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    Journal für Praktische Chemie/Chemiker-Zeitung 329 (1987), S. 483-492 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Synthesis of Bipolar Ion Exchange ResinsSyntheses of weakly acid/strongly basic and weakly acid/weakly basic bipolar ion exchange resins with varying acid and basic capacities via subsequent introduction of the exchange active groups in suitable crosslinked skeletal polymers are described.Methylacrylate-styrene-divinylbenzene polymers of varying composition which can be quantitatively chloromethylated and subsequently fully aminated (trimethylamine) and partially saponified in one process step were used as starting polymers for weakly acid/strongly basic resins. The reverse route saponification of the ester groups first, followed by chloromethylation of the aromatic parts of the matrix and animation turned out to the possible, if at all, only for bipolar resins of strongly predominant basic character. The capacity parameters can be controlled through the composition of the matrix.Polymethylacrylates crosslinked with divinylbenzene served as polymer basis of the weakly acid/weakly basic bipolar ion exchange resins. The functionalization was achieved by partial aminolysis with polyamines (dimethylaminopropylamine, ethylenediamine, diethylenetriamine) and saponification with lyes. The number of basic and acid groups which can be introduced is governed primarily by the conditions of the aminolysis. The capacity parameters are controllable within a broad range by the procedures.
    Additional Material: 6 Tab.
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  • 63
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    Journal für Praktische Chemie/Chemiker-Zeitung 329 (1987), S. 499-510 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Pyrylium Compounds. 36. Substituted Benzoic Acid Esters from 2,4,6-Triarylpyrylium Salts and α-Ketocarboxylic Acid Esters2,4,6-Triarylpyrylium salts 1 react with α-ketocarboxylic acid esters 2 in the presence of two equivalents of an appropriate condensing agent (e.g. dialkylamine salts of weak acids, triethylamine/acetic acid, or sodium acetate) to give 2-aroyl-3,5-diarylbenzoic acid esters 3. However, using only one equivalent of the condensing agent, the formation of 3,5-diarylbenzoic acid esters 5 predominates. Alkaline saponification of the new esters 3 and 5 yields the corresponding substituted benzoic acids 4 and 6, respectively. - I.r., u.v., n.m.r. and mass spectroscopic data of the novel products 3-6 are reported.
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  • 64
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    Journal für Praktische Chemie/Chemiker-Zeitung 329 (1987), S. 681-698 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zwischen der Analytik einerseits und der Verarbeitungstechnologie des Erdöls andererseits besteht eine enge Wechselbeziehung. Insbesondere stellt die zunehmende Bedeutung der hochsiedenden Erdölbestandteile für die Erzeugung von leicht- und mittelsiedenden Produkten wachsende Anforderungen an die Analytik. Als Beitrag dazu soll hier eine UV-spektroskopische Methode zur Bestimmung des Aromatengehaltes sowie der Aromatenstrukturtypenverteilung in hydroraffinierten Erdölprodukten im Siedebereich 433-773 K vorgestellt werden.Grundlage für eine UV-spektroskopische Mehrkomponentenanalyse ist die genaue Kenntnis der Extinktionskoeffizienten, wobei für n-Komponenten mindestens n Meßstellen erforderlich sind, an welchen die Extinktionskoeffizienten der Einzelkomponenten bekannt oder bestimmbar sein müssen. Dieses klassische Verfahren wurde auch bereits für die Aromatenstrukturtypenanalyse von Erdölfraktionen angewandt, z.B. in [1-3]. Bei der Benutzung dieser Arbeiten haben wir allerdings erhebliche Abweichungen zu den Ergebnissen anderer Methoden (1H-NMR-Spektroskopie und Elutions-Adsorptions-Chromatographie) erhalten. Wir führen das darauf zurück, daß die verwendeten Extinktionskoeffizienten die zu analysierenden Strukturtypen ungenügend repräsentieren. Mit der allgemein zur Präparation reiner Strukturtypen eingesetzten Elutions-Adsorptions-Chromatographie ist eine genügend scharfe Trennung der einzelnen Typen bei Einsatz breiter Siedeschnitte auch kaum möglich. Davon ausgehend, wurden eigene Untersuchungen auf der Basis von 20 K-Siedeschnitten durchgeführt, deren Ergebnisse hier mitgeteilt werden sollen.
    Notes: Aromatic Structure Type Analysis of Hydrotreated Petroleum Fractions by U.V.-Spectroscopy20 K boiling cuts were produced from hydrotreated petroleum products by means of distillation. From such close fractions, defined pure aromatic types can be separated by preparative elution adsorption chromatography (EAC) on dual-packed (Silicagel-Alumina gel) columns. The extinction coefficients of the various separated types are measured at suitable wave lengths and used for calculating the average extinction coefficients of aromatic types for wide boiling fractions. Utilizing these values on quantitative u.v.-analysis of technical hydrotreated products, the results correspond well with those of EAC and 1H-n.m.r. spectroscopy.
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  • 65
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    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: N.M.R. and U.V.-VIS Spectroscopic Investigations on Push-pull Butadienes13C-n.m.r., d-n.m.r. and u.v.-vis spectroscopical data show that the push-pull character of the investigated butadienes is lowered by substitution at the carbon atom in 3-position of the butadiene chain.
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  • 66
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    Journal für Praktische Chemie/Chemiker-Zeitung 329 (1987), S. 731-731 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
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  • 67
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    Journal für Praktische Chemie/Chemiker-Zeitung 329 (1987), S. 780-786 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: It is shown that the anions of the enolate forms of 1, 2- and 1, 3-indandiones have antiaromatic character. This conclusion is reached after studying the geometry, the electron density distribution and the energy spectrum of the molecules.The anion of the 1,2-indandione enolate form is unstable because of strong electron-vibronic interaction.
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  • 68
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    Journal für Praktische Chemie/Chemiker-Zeitung 329 (1987), S. 775-779 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Me⊕ (Me = Na; K) cations in MeClO3 chlorates were complexed by crown ethers (CE): 12C4, 15C5 and 18C6 in solution. In the solid phase we could obtain only Na(15C5)ClO3 and K(18C6)ClO3 complexes significant shift in 35Cl-n.q.r. frequency with respect to the frequency of pure sodium and potassium chlorates was observed. The shifts at 77K were -2.879 MHz for Na(15C5)ClO3 and -1.004 for K (18C6)ClO3.For other reaction mixtures the 35Cl-n.q.r. frequencies observed were the same as for the appropriate pure chlorates which confirmed that the expected complexation in the solid phase had not occurred. The investigation described in this paper proved a rapid increase in selectivity of crown ethers at the transition from the solution to the solid state. Moreover, in the solid phase of Me(CE)ClO3 complexes a significant increase was found in the shielding effect of the Me⊕ cation by the surrounding crown ether.
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    Journal für Praktische Chemie/Chemiker-Zeitung 329 (1987), S. 811-816 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Organic Electron Conductors and Precursors. V. Synthesis of Poly (organylthio-acetylenes)Poly(bis-organylthio-acetylenes) 2 and poly(mono-organylthio-acetylenes) 3 have been synthesized by complex catalyzed polymerization of the corresponding acetylenes (4 resp. 5). Yields and properties of the polymers 2, 3 depend on reaction conditions, the catalyst and the nature of the acetylenes. Relations between these influence factors are discussed.
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    Journal für Praktische Chemie/Chemiker-Zeitung 329 (1987), S. 859-870 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Photochemistry of Aminoketones. X. Preparation and Diastereoselective Photocyclization of N-(β-Benzoylethyl)-N-tosyl-glycinamidesThe title compounds 4 were prepared by MICHAEL-like addition of N-tosylglycinamides to phenyl-vinyl-ketone, generated from ω-bromo-propiophenone. 300 nm Irradiation of 4a-c (CO-NH) in benzene and acetone, respectively, causes, n, π*-excitation and photocyclization to (3-ref-2-cis)-3-hydroxy-3-phenyl-N-tosylprolinamides 5. Under the same conditions 4d-h (CONAlk2) yield (3-ref-2-trans)-prolinamides 6. The difference in diastereoselectivity is explained by intramolecular dipolar interaction in 4* and intramolecular hydrogen bondings in the intermediate hydroxybiradicals.
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    Journal für Praktische Chemie/Chemiker-Zeitung 329 (1987), S. 871-876 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Reaction of O, O-Dimethyl Phosphoramidothioate with ChloralThe system O,O-dimethyl phosphoramidothioate (1)/chloral was investigated at room temperature. Two competing reactions occur: (A) formation of the 1:1 adduct 2, and (B) sulfur/oxygen exchange yielding the oxo compound 3, which subsequently forms a chloral adduct 4.
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    Journal für Praktische Chemie/Chemiker-Zeitung 329 (1987), S. 885-894 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: About the Catalysis of the PRILEŽAEV ReactionIt is shown that a catalysis of the PRILEŽAEV reaction exists. We investigated the influence of homogeneous molybdenum catalysts on the epoxidation reaction of olefins with percarboxylic acids kinetically. The second order reaction rate data show that the MoO2(acac)2 catalyzed cyclohexene epoxidation with peracetic acid runs two times faster than the uncatalyzed reaction and the same epoxidation of oct-1-ene runs 15 to 30 times faster. In the same way the reduction of activation parameters in the catalytic reaction proves the catalytic effect. An influence of catalyst concentration and a formation period at the beginning of the catalytic reaction were observed. The influence of the structure of olefin and of the kind of catalyst were investigated and discussed. A formulation of the transition state is given and discussed in relation to the uncatalyzed PRILEŽAEV reaction and to the Halcon reaction.
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    Journal für Praktische Chemie/Chemiker-Zeitung 329 (1987), S. 895-900 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Protonation and Solvation of Weak Organic Bases. III. U.V. and 1H-N.M.R. Spectroscopic Investigations of the Basicity of 1,3-DiketonesBy 1H-n.m.r. spectroscopy it is possible to determine separately the basicity parameters (H0)1/2 or pKBH⊕ and the solvation paramters m, φ or m* for the keto and the enol form of acetylacetone. By u.v. spectroscopy only brutto parameters of the equilibrium mixture for acetyl- and benzoylacetone as for dibenzoylmethane are available.
    Additional Material: 2 Ill.
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  • 74
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    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Oligosiloxanes with Functional Groups. II. Reaction of 1.4-Bis(trimethylsiloxy)-but-2-ene with H-Silanes in the Presence of Hexachloroplatinic AcidThe synthesis of silicon-modified butane-1.4-diol derivatives by the hydrosilylation of 1.4-bis (trimethylsiloxy) but-2-ene (1) is described. Under the conditions of the hydrosilylation 1 is isomerized with high selectivity. At a temperature above 150°C hydrosilylation and isomerization take place simultaneously.
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    Journal für Praktische Chemie/Chemiker-Zeitung 329 (1987), S. 915-922 
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    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
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    Journal für Praktische Chemie/Chemiker-Zeitung 329 (1987), S. 922-922 
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    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
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    Journal für Praktische Chemie/Chemiker-Zeitung 329 (1987), S. 923-926 
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    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Preparation of 4′-Alkanoylbenzo[15]-crown-5-Ethers
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    Journal für Praktische Chemie/Chemiker-Zeitung 329 (1987), S. 930-932 
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    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
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    Journal für Praktische Chemie/Chemiker-Zeitung 329 (1987), S. 937-944 
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    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Azomethines from Furancarboxaldehydes and α-Amino-N-heterocycles
    Additional Material: 1 Tab.
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  • 80
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    Journal für Praktische Chemie/Chemiker-Zeitung 329 (1987), S. 985-995 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Reaction of (Z/E)-1-Aryl-4-arylmethylene-pyrrolidine-2,3,5-triones with Enaminocarbonyl CompoundsTreatment of the α, β-unsaturated ketones (Z/E)-1a-e with alicyclic or aliphatic enamines afforded cyclic Michael adducts 2 and 3a-e, respectively. By dehydration of the N,O-hemiacetals 3b-d the corresponding 1,4-dihydropyridines 4a-c were obtained.The acid-catalyzed reaction of aminosubstituted maleimides with (Z/E)-1e, aldehydes or indan-1,2,3-trione led to 5a-c, 6a-c, 7a-c and 8. O-Methylation of the aryl-bis(maleinimidyl)methanes 5c, 6c by using diazomethane gave 5d, 6d, whereas 5a cyclized spontaneously to the 1,4-dihydropyridine 9a. Further 1,4-dihydropyridines were prepared by cyclocondensation of 6a, b in the presence of ammonium acetate and oxidized to the pyridine derivative 10.
    Additional Material: 5 Tab.
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  • 81
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Photochemical Primary Processes of Xanthene Dyes. VIII. Influence of Mixed Micelles on the Photochemical Primary Processes of Selenopyronine and Erythrosine and the Sensitized Photolysis of Diazonium SaltsThe influence of the nonionic detergent dodecyltriglycol (DTG) on the escape rate of dye ions from cationic and anionic micelles is investigated. The rate constant of the escape of selenopyronine ions (Sp⊕) from mixed micelles of sodium dodecylsulfate (NDS) and DTG (1:1) (kA ≍ 3,2 · 104 s-1) is, as a result of the lower charge density, higher by the factor 10 than that from clean NDS-micelles (kA ≍; 2,8 · 103 s-1). Erythrosine ions (Et2⊖) are tightly fixed to cetyltrimethylammoniumbromide (CTAB)-micelles (kA ≍; 0,25 · 103 s-1) and to mixed micelles of CTAB and DTG (1:1). This may be a result of the twofold negative charge of the erythrosine ions. Properties of the mixed micelles (polarity, average aggregation numbers) are determined by using the dyes and pyrene as probes. The sensitized photolysis of diazonium salts by electron transfer from photoexited selenopyronine under aerobic conditions is more effective by a factor of 3-5 in the presence of anionic micelles than when in a water solution.
    Additional Material: 3 Ill.
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  • 82
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The aldol reaction of the substituted cyclopentane carbaldehydes 1 with heptan-2-one was demonstrated to offer an effective alternative to the carbonyl olefinations generally used for the build-up of the (E)-3-oxooct-1-enyl side chain of 11-deoxyprostaglandins. In this case dimethyl 2-oxoheptylphosphonate can be substituted advantageously by the cheaper heptan-2-one as side chain precursor.
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  • 83
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    Journal für Praktische Chemie/Chemiker-Zeitung 329 (1987), S. 1038-1038 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
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  • 84
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    Journal für Praktische Chemie/Chemiker-Zeitung 329 (1987), S. 1045-1051 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Investigations on the Tautomerism of o,o'-Dihydroxy Azo Dyes of the Eriochrome TypeInvestigation of the u.v.-vis-, 1H- and 13C-n.m.r. spectra of the title substances and the isomers 3 and 3p at different pH-values and in different solvent mixtures as well as of O,O'-dimethyl derivatives of 2 and 3 show that in aqueous solution as well the monoanions as the trianions exist in the azo forms only. The dianions exist in dependence on the solvents as mixtures of tautomers. The results of PPP calculations for different prototropic structures are in good accordance with the experimental results.
    Additional Material: 4 Ill.
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  • 85
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A product study of the reaction between a number of aromatic amines substituted with widely different groups and paraformaldehyde in inert solvents was performed and found to yield 1,3,5-triaryl-1,3,5-hexahydrotriazines, 1,3,5,7-tetraaryl-1,3,5,7-tetrazocines and formaminals. It was not possible to correlate the product outcomes with the actual structure of the amine substrate. The X-ray diffraction structural determination of 1,3,5-tri-(t-butylphenyl)-(1b) and 1,3,5-tri-(m-fluorophenyl)-1,3,5-hexahydrotriazine (1c) showed the diaxial arrangement of the N-substituents.
    Additional Material: 2 Ill.
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  • 86
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    Journal für Praktische Chemie/Chemiker-Zeitung 329 (1987), S. 1071-1086 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The electrochemical reduction of some N-acylamino-, N-amino-, N-benzyl- and N-phenacyl-substituted pyridinium and triazolium ions is investigated in acetonitrile by voltammetric methods and potentiostatic electrolyses. The acylaminopyridinium ions 1 and the arylaminopyridinium ions 3 are cathodically cleaved into the pyridine derivative and the carboxylic amide or the aromatic amine. In the case of the 1-benzyl-4-acylaminotriazolium ions 5 the reductive formation of hydrogen from the acidic N-acylamino group is preferred and the corresponding ylide is formed, which reacts at more negative potential by splitting off the benzyl group. The reduction of the N-phenacylpyridinium ion 7d occurs with splitting off the phenacyl radical, which dimerizes to 1,2-dibenzoylethane in a good yield. In the case of N-benzyl- and N-p-cyanobenzylpyridinium ions the cathodic dimerization to the corresponding bisdihydropyridines was found, whereas the electrolysis of the N-nitrobenzylpyridinium ions occurs with cleavage of the N-substituent-bond, which is initiated by the primary formation of the nitrophenyl anion radical. It follows from electrogenerated chemiluminescence experiments that the cleavage of the cations 1 and 5 occurs with the uptake of one electron.
    Additional Material: 5 Ill.
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  • 87
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    Journal für Praktische Chemie/Chemiker-Zeitung 329 (1987), S. 1104-1110 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: EPR-Spectroscopic Characterization of Assoziating Cu(II)-complexes of Vinylogic AmidesThe e.s.r. spectra of glassy solutions of the Cu(II)-complexes with different enaminone-ligands were measured in dependence on substituents and solvent polarity.Cu—Cu distance and spatial angle α are calculated using the model of SMITH and PILBROW. In methylcylohexane only dimers could be detected. Two types of dimeric compounds were observed for which an interplane distance of r = 0.4 nm was calculated.In dimeric Cu-complexes of 4-anilinomethylen-δ2-pyrazolin-5-ones the Cu—Cu axis is perpendicular (α = 0°), in dimeric Cu-complexes of anilinomethylenpentan-2,4-diones the Cu—Cu-axis is inclined (α = 35°).
    Additional Material: 4 Ill.
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  • 88
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    Journal für Praktische Chemie/Chemiker-Zeitung 329 (1987), S. 1123-1130 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Synthesis of trans-4-(ω-Cyanalkyl)-cyclohexanols
    Additional Material: 6 Tab.
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  • 89
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    Journal für Praktische Chemie/Chemiker-Zeitung 329 (1987), S. 29-38 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Structure-Dependent Properties of Detergents as Studied at 2-Alkylsulphates, Phosphine-oxides, and ω-H-Perfluoroalkyl CompoundsCMC values from δ/lg c-curves were determined for the homologous series of 2-alkyl-branched alkylsulphates, dimethyl- an diethyl-phosphine-oxides and ω-H-perfluoroalkyl-sulfosuccinates. On this basis effective chainlengths were calculated and correlated with other properties as maximum of surface tension depression, wettability and foaming.
    Additional Material: 6 Ill.
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  • 90
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    Journal für Praktische Chemie/Chemiker-Zeitung 329 (1987), S. 55-61 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Intramolecular 1,3-Dipolar Cycloadditions of Aryl Azides with Alkynyl SubstituentsReaction of substituted 4-chlorobut-2-ynes 1 with 2-acetaminophenol and 2-aminothiophenol, respectively, leads to the corresponding ethers and thioethers 3 that can be converted into the alkynyl substituted aryl azides 4 by diazotation and reaction with sodium azide. Intramolecular 1,3-dipolar cycloaddition yields 4H-[1,2,3]triazolo [5,1-c] [1,4] benzoxazines and benzothiazines 5. In the same way 1,4-bis(2-acetaminophenoxy)but-2-yne 6 reacts to a 3-(2-azidophenoxy-methyl)-triazolobenzoxazine 9. Its thermal decomposition gives the azomethine 11.
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  • 91
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: On 1.2-Shift Reactions and C—H-Insertions of Acyclic Alkylidene CarbenesTwo series of acyclic terminal vinyl bromides (1…4 and 5…7) were tested in the reaction with potassium tert-butoxide as precursors of alkylidene carbenes. As expected 1 up to 4 only give 1-alkynes whereas the 2-methylated vinyl bromides 5, 6 and 7 yield 1-methylated cyclopentenes predominantly besides 2-alkynes. The formation of cyclopentenes indicates a reaction route via alkylidene carbenes and 1,5-C—H-insertion reactions, that of 2-alkynes is convincing evidence for 1,2-alkyl shift reactions in 2-methyl substituted alkylidene carbenes. The selectivity of 1,5-C—H-insertion depends on the degree of alkyl substitution of the C-5-atom. At 240°C the selectivity is 1°:2°:3° ≈ 1:54:240.
    Additional Material: 1 Tab.
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  • 92
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Quinoxalines. XXIV. Synthesis of 4-Substituted 1,2,3-Triazolo [1, 5-a] quinoxalines3-Substituted quinoxaline-2-carbaldehydes 1 react with tosylhydrazide to give 3-substituted quinoxaline-2-carbaldehyde tosylhydrazones 2. The treatment of 2 with a boiling solution of sodium methoxide or ethoxide - the so called Bamford-Stevens reaction - leads to 4-substituted 1,2,3-triazolo[1,5-a]quinoxalines 4 in high yields. Some of these compounds were also obtained by thermolysis of 2.
    Additional Material: 1 Tab.
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  • 93
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    Journal für Praktische Chemie/Chemiker-Zeitung 329 (1987), S. 126-130 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 3 Tab.
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  • 94
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    Journal für Praktische Chemie/Chemiker-Zeitung 329 (1987), S. 131-136 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Preparative Electrolytic Oxidàtion of Lower Aliphatic Alcohols
    Additional Material: 7 Ill.
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  • 95
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    Journal für Praktische Chemie/Chemiker-Zeitung 329 (1987), S. 141-144 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 1 Tab.
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  • 96
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Iminoformylation Reaction of Substituted Crotonnitriles. II. On the Reaction of Ylidenmalononitriles with Formamide Acetals in the Presence of Acetic Acid
    Additional Material: 1 Tab.
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  • 97
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    Journal für Praktische Chemie/Chemiker-Zeitung 329 (1987), S. 176-176 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
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  • 98
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    Journal für Praktische Chemie/Chemiker-Zeitung 329 (1987), S. 194-194 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
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  • 99
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    Journal für Praktische Chemie/Chemiker-Zeitung 329 (1987), S. 276-276 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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  • 100
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    Journal für Praktische Chemie/Chemiker-Zeitung 329 (1987), S. 277-282 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Wittig condensation of (Z)-2-pentenylidene triphenylphosphorane (14) and 7-tert.-butoxy-heptanal (13) under conditions of phase transfer catalysis and subsequent conversion into the corresponding acetate afforded a mixture of 28% 7(E),9(Z)-dodecadien-1-yl acetate, the sex pheromone of Lobesia botrana, along with the other geometrical isomers and 30% unidentified by-products. The synthons 14 and 13 were prepared starting with (Z)-2-butene-1,4-diol (1) and hexane-1,6-diol (9), respectively.
    Additional Material: 1 Tab.
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