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  • 1980-1984  (5,483)
  • 1975-1979
  • 1930-1934
  • 1920-1924
  • 1890-1899
  • 1981  (5,483)
  • Polymer and Materials Science  (3,049)
  • Life and Medical Sciences  (842)
  • Inorganic Chemistry  (704)
  • Chemical Engineering  (460)
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  • Rat  (109)
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  • 1980-1984  (5,483)
  • 1975-1979
  • 1930-1934
  • 1920-1924
  • 1890-1899
Year
Keywords
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Rheumatology international 1 (1981), S. 21-28 
    ISSN: 1437-160X
    Keywords: Rheumatoid nodules ; Polymorphonuclear granulocytes ; Electron microscopy ; Collagen degradation products
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Necrotic areas of rheumatoid nodules were investigated electron microscopically. PMNs in different stages of disintegration were present in all cases. Granular material, sometimes in a fiberlike orientation, and small fibrils without periodicity were detected between the collagenous fibers. It is assumed that granular material and fibrillar remnants represent degraded collagen. Often these degradation products were present in the neighborhood of disintegrating PMNs. From this morphological relationship it is concluded that enzymes of PMNs may in part be responsible for the fibrinoid necrosis in rheumatoid nodules.
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 1432-0711
    Keywords: Ovary ; FSH ; Inhibin ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The effects of a highly purified preparation of human follicular fluid inhibin (hFF-Inhibin) on the ovary of immature rats have been studied. The highly purified preparation was obtained by gel and ion-exchange chromatography and ultrafiltration of the acetone dried extract of human follicular fluid. Administration of 5, 10, or 20 μg of inhibin daily for 10 days starting from day 11 postnatum resulted in (1) a significant reduction of basal FSH levels by the 20 μg dose but not by lower doses, (2) atresia of preantral and antral follicles in an apparently dose-related manner, (3) hyperplasia of the theca interna, and (4) degeneration of the granulosa cells, maximum damage being in the group treated with 20 μg. In inhibin-induced atretic follicles there were no signs of (a) granulosa cell-luteinisation, (b) connective tissue invasion, (c) hyalinisation of the basement membrane, or (d) vascularisation. Simultaneous administration of human menopausal gonadotrophin (hMG) led to luteinisation of the atretic follicles. However, the other structural alterations mentioned above (b-d), and those of the theca cells could not be overcome by hMG. In addition, there was no significant difference in the ovarian weight of animals treated with hMG when compared to those treated with inhibin and hMG, but the serum levels of the oestradiol in the latter were significantly lower. Our results suggest that hFF-inhibin acts not only at the pituitary, but also at the ovarian level.
    Type of Medium: Electronic Resource
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  • 3
    ISSN: 1432-2072
    Keywords: Cyclazocine ; Acute treatment ; Dopamine ; Noradrenaline ; Serotonin ; Monoamine metabolites ; Brain regional assay ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The effects of cyclazocine on the metabolism of dopamine (DA), noradrenaline (NA) and 5-hydroxytryptamine (5-HT) in regions of rat brain were studied by measuring changes in the levels of the monoamines and their major metabolites. Doses ranging from 4–32 mg/kg were tested. Rats were sacrificed 1 or 2 h after administration of the drug, according to the experiment. Administration of cyclazocine significantly decreased DA concentration and increased the levels of DOPAC and HVA in striatum. Cyclazocine decreased the levels of NA, and markedly increased the levels of MHPG-SO4 and 5-HIAA in cortex, hypothalamus, midbrain and pons-medulla, while little change in 5-HT concentration, except a decrease after the highest dose, was observed. These changes in the metabolism of the monoamines differed in their amplitude and temporal nature. The possible roles of dopaminergic, noradrenergic and serotoninergic neurons in different brain regions are discussed in relation to modifications of locomotor activity and the induction of bizarre behavior resulting from cyclazocine administration in rats. These investigations may add to the understanding of the mechanism of psychotomimetic effects produced in man by this drug.
    Type of Medium: Electronic Resource
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  • 4
    ISSN: 1432-2072
    Keywords: Ethanol tolerance ; Serotonin ; Norepinephrine ; Dopamine ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Rats were permanently depleted of brain dopamine (DA), serotonin (5-HT), 5-HT+norepinephrine (NE), or NE +DA by intraventricular injection of either 5,7-dihydroxytryptamine (5,7-DHT) or 6-hydroxydopamine (6-OHDA) with or without pretreatment with desmethylimipramine (DMI). Following 1 week of recovery from surgery, daily treatment with ethanol (5 g/kg, PO) or isocaloric sucrose was carried out for a period of 20–25 days. Testing at 5-day intervals showed that chronic ethanol treatment produced tolerance to the hypothermic and motor impairing effects of ethanol. Depletion of 5-HT alone retarded tolerance, while depletion of NE or DA alone produced no effect. Combined depletion of both NE and 5-HT, however, completely inhibited tolerance development. The inhibition of tolerance development by combined depletion of both NE and 5-HT is dicussed in terms of a reciprocal relationship between these two systems.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Psychopharmacology 75 (1981), S. 236-239 
    ISSN: 1432-2072
    Keywords: Water lick paradigm ; Punishment suppressed behaviour ; Conflict ; Anxiolytics ; Serotonin antagonism ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract A modified water-lick conflict paradigm is described, using trained rats for up to 35 weekly test sessions under 48 h of water deprivation. The rats rapidly became maximally suppressed by the punishment. This suppression was attenuated by the anxiolytics lorazepam, diazepam, phenobarbital, and meprobamate. The potentially anxiolytic drug CL 218872 and the anticonvulsant drug valproate sodium were also active. The antiserotonin drugs methysergide, cyproheptadine, cinanserin and parachlorophenylalanine were all inactive, as were several other distinct classes of psychotropic drugs including propranolol, clonidine, THIP, theophylline, chlorpromazine, paroxetine and ethanol. The paradigm proved reliable, reproducible and useful for large scale investigations. Furthermore, it may provide means for detailed neuropharmacological and anatomical studies.
    Type of Medium: Electronic Resource
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  • 6
    ISSN: 1432-2072
    Keywords: Ovariectomy ; Castration ; Chronic LiCl treatment ; Apomorphine ; Stereotyped behavior ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The effects of ovariectomy, castration, and chronic lithium chloride treatment on stereotyped behavior (SB) induced by apomorphine (APO) (0.3–0.6 mg/kg) were investigated in rats. Duration of stereotyped behavior (interval between APO injection and termination of SB) increased in ovariectomized rats compared to female control rats. Castration had no effect on the duration of stereotyped behavior. On the other hand, ovariectomized rats that were treated chronically with LiCl (2 mEq/kg daily) showed no difference in duration of stereotyped behavior compared to female controls chronically treated with LiCl. Neither treatment group showed a significantly altered intensity of stereotyped behavior compared with the appropriate control. These findings are consisten with the hypothesis that estrogen deficit contributes to a greater incidence of neuroleptic-induced tardive dyskinesia in postmenopausal women than in men of comparable age. Furthermore, LiCl may attenuate the symptoms associated with increased postsynaptic dopamine receptor sensitivity following ovariectomy.
    Type of Medium: Electronic Resource
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  • 7
    ISSN: 1432-2307
    Keywords: Liver biopsy ; Renal transplant recipients ; HBs and HBc Ag ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A prospective series of 45 liver biopsies taken from 22 renal transplant patients was investigated for the presence of hepatitis B antigen core (HBc) and surface (HBs) components by electron microscopy. At the time of each biopsy serum HBs Ag was sought by radioimmunoassay. Sections were taken for the detection of HBs Ag by immunofluorescence. In seropositive patients, intravesicular tubular structures resembling HBs Ag were found in 61% of biopsies while the intranuclear core HBc was present in 69%. No correlation could be made between the ultrastructural pattern of the viral components and the intensity of the histological liver damage. During the follow up, there was an accumulation of both HBs and HBc Ag even in a period as short as 1 year. The 9 liver specimens examined after three years of transplantation showed a marked accumulation of both antigens. Thus the expression of HB Ag at the hepatocellular level seems to correlate better with the duration of antigenaemia than with the histological pattern. Lastly, on matched semithin and ultrathin sections, the ground glass appearance of cytoplasm appeared to correlate with smooth endoplasmic reticulum distorsion, irrespective of the simultaneous presence or absence of intravesicular tubular structures. The sanded nuclei expressed a rare massive accumulation of core antigen.
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    Springer
    Virchows Archiv 391 (1981), S. 165-175 
    ISSN: 1432-2307
    Keywords: Dermatofibrosarcoma protuberans ; Tissue culture ; Electron microscopy ; Fibroblasts ; Fibrosarcoma
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Dermatofibrosarcoma protuberans has been considered to be of fibrohistiocytic or fibroblastic origin. The purpose of this paper is to identify the original cell strain from which this neoplasm derives, using tissue culture and electron microscopic methods. Thirteen cases of DFSP characterised by clinical, topographical, histological and behavioral criteria were explanted. The emigrating cells were bipolar with two opposed processed and showed a radial arrangement in respect to the expiants. After the second week the distal processes tended to curve back towards the cell body forming flame-like structures. This cell morphology and cellular orientation persisted during the whole life of the culture. Electron microscopy was performed in three cases; the newly grown cells maintained an electron microscopic picture similar to that found in the original tumors. This pattern of behaviour is characteristic of fibroblastic tumors and has been found in explants of normal fibroblasts, of fibromatosis and of fibrosarcomas used as controls. On this basis, we believe that DFSP is a fibrosarcoma of the skin of low grade malignancy.
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    Springer
    Virchows Archiv 390 (1981), S. 11-21 
    ISSN: 1432-2307
    Keywords: Electron microscopy ; Bladder neoplasms ; Measurement
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The ultrastructure of urothelium from 4 patients with no evidence of tumour was compared with that taken from 22 patients with bladder neoplasms of different grade and stage. Two features were quantified: the percentage of reduplication of the basal lamina and the percentage of discontinuous basal lamina. Tumours showed a lower percentage of reduplicated basal laminae than normal tissues, the difference being significant in 3 out of 4 types of tumours. The difference in frequency between normal tissues and non-recurring tumours was not significant, but there was a significant difference between normals and recurring tumours. All types of tumours showed discontinuities in the basal lamina, including 80% of those staged non-invasive by light microscopy. None of the normal tissues showed these. The percentage of discontinuities seen in non-recurrent tumours was half that seen in recurrent ones, but both groups were significantly higher than normals. Loss of continuity of the basement membrane distinguishes invasive from non-invasive tumours. However, there is a high probability of these being missed by light microscopy alone. Therefore, electron microscopic studies on recurrent bladder tumours would increase the accuracy of staging and prognosis.
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  • 10
    ISSN: 1432-2307
    Keywords: Microfold (membraneous) cells ; Tuft cells ; Electron microscopy ; Horseradish peroxidase ; Sequential uptake
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary 79 NMRI mice and Wistar rats were used for ultrastructural investigations of the sequential uptake of horseradish peroxidase (HRP) by M cells. In addition the ultrastructure of the so-called tuft-cells was reported. HRP, a foreign protein antigen, was applied either by injection (Owen 1977), or by stomach tube. After variable exposure times (5 min to 3 h) segments of the distal small intestine, containing Peyer's patches, mesenteric lymph nodes and liver tissue were removed. After fixation, they were reacted with H2O2-3,3′-diaminobenzidine tetrachloride and were examined by light and electron microscopy for HRP reaction products. The uptake of HRP mainly occurs through the M cells in the dome epithelium of Peyer's patches with a continual transport of the antigenic material into lymphoid cells, macrophages, and dendritic reticulum cells. In the 3 h specimens a few single HRP-positive lymphoid cells can be observed within the efferent lymphatics of Peyer's patches. In addition, a continual uptake of HRP by necrobiotic enterocytes was observed. It has also been shown that after 3 h HRP is located inside the Kupffer cells of the liver. These findings also support the presumption that antigenic material can be transmitted via the portal circulation. However, definite, quantitatively and permanently recorded uptake of HRP by brush border cells was not be observed. To exclude a toxic effect of the applied HRP on the enterocytic epithelium additional resorptive-physiological investigations were performed using the in vivo-perfusion-recirculation method and in vitro-accumulation of L-phenylalanine.
    Type of Medium: Electronic Resource
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  • 11
    Electronic Resource
    Electronic Resource
    Springer
    Virchows Archiv 391 (1981), S. 107-115 
    ISSN: 1432-2307
    Keywords: Hemangioendothelioma ; Esophagus ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The histology and electron-microscopy of a malignant hemangioendothelioma of the esophagus wall appearing in a 42 year old male is presented. By light microscopy the tumor is composed of vessels and capillary-like structures of an anastomosing nature covered by atypical endothelial cells. These cells infiltrate the intersticial spaces growing into the posterior mediastinal area. Electron microscopy confirms the endothelial nature of the neoplastic cells, showing characteristics of the cell type, as is the presence of Weibel-Palade bodies, filaments and active pinocytosis. Hemangioendothelioma should be differentiated from other vascular tumors (angiosarcoma) as are hemangiopericytoma or hemangioblastoma, being composed exclusively of malignantly transformed endothelial cells.
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  • 12
    ISSN: 1432-2307
    Keywords: Crohn's disease ; Electron microscopy ; Ultracytochemistry ; Immunohistology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Immunohisto- and ultracytochemical studies were carried out on surgical and biopsy specimens from 27 patients suffering from Crohn's disease of the ileum or colon. Control specimens were obtained from 16 patients with nonspecific proctitis or neoplastic disorders of the caecum or rectum. Our results suggest that the initial lesions in Crohn's disease are associated with a typical humoral immune response. In non-ulcerated mucosa a uniform increase of IgA-, IgG- and IgM-cells was found (numbers of IgA-cells: IgG-cells ∼14.4), whereas disproportional increases of IgG- and IgE-cells were observed in ulcerated mucosa (IgA:IgG ∼0.7). The IgE-cell multiplication in ulcerated areas suggests the possibility of local hypersensitivity reactions. Macrophages and granulocytes contained IgG, which was also demonstrated in multinucleated giant cells. The granulomas contained extracellular IgG, acid phosphatase and peroxidase. The finding of potentially harmful extracellular lysosomal enzymes may be of pathogenetic significance in view of the hypothesis of Weissmann (1964). Micro-ulcerations of the dome epithelium of hyperplastic Peyer's patches were seen by electron microscopy a finding which can be interpreted as an early lesion through which luminal antigens gain uncontrolled access to Peyer's patches. This could lead to (1.) overstimulation of the local immune system, (2.) disturbance of local immune homeostasis, (3.) imbalanced Ig-production with disproportional increases in IgG and IgE. We were not able to detect Clq or C3 bound to epithelial or vascular basement membranes, and no electron dense deposits were found. Viral particles or bacteria in any of the specimens were not demonstrated by electron microscopy. The type of immune response in Crohn's disease and its pathogenetic significance with remain unclear until more is known about the specificity of the locally produced antibodies.
    Type of Medium: Electronic Resource
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  • 13
    Electronic Resource
    Electronic Resource
    Springer
    Virchows Archiv 391 (1981), S. 291-299 
    ISSN: 1432-2307
    Keywords: Submandibular gland ; Rat ; Irradiation ; Enzyme histochemical study ; Ultrastructural study
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Single-dose cervical irradiation by cobalt 60 in rats induced lasting functional disturbances of the submandibular gland which were excessive when compaired with the relative integrity of the gland as seen under the light microscope. Enzyme histochemical and ultrastructural studies revealed severe damage shortly after exposure with appearance of karyolytic bodies and autophagosomes accompanied by increased hydrolase activity. Mitochondrial alterations were concomitant with diminished ductal oxidative enzyme activity. Although most of these alterations resolved rapidly as a result of acinar and ductal cell repair and regeneration originating in the intercalated ducts, secretory abnormalities were still observed two months after exposure as evidenced by the accumulation of granules in acinar cells and the heterogeneity of ductal cell granules. These anomalies, comparable to those observed in sialadenoses, probably result from persistent alterations of intralobular nerve endings.
    Type of Medium: Electronic Resource
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  • 14
    Electronic Resource
    Electronic Resource
    Springer
    Virchows Archiv 392 (1981), S. 135-145 
    ISSN: 1432-2307
    Keywords: Malignant fibrous histiocytoma ; Sarcoma ; Soft tissue neoplasms ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The ultrastructural findings in 17 cases of malignant fibrous histiocytoma (MFH) are described. The tumors consisted of fibroblast-like cells and histiocyte-like cells in different proportions in different cases. Intermediate, undifferentiated, xanthomatous and multinucleated giant cells were also identified. In 12 of 17 cases myofibroblasts were evident. Acid phosphatase activity was detected cytochemically in the Golgi zone, endoplasmic reticulum and lysosomes (GERL) mainly within histiocyte-like cells, in three cases. These observations indicate that the GERL of the tumor cells are engaged in the formation of lysosomes. The polymorphic cellular composition, including undifferentiated cells, lends support to the concept that the MFH originates from a primitive multipotent undifferentiated mesenchymal cell.
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  • 15
    Electronic Resource
    Electronic Resource
    Springer
    Virchows Archiv 392 (1981), S. 231-239 
    ISSN: 1432-2307
    Keywords: Bronchial gland adenoma ; Oncocytoma ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Benign adenomas derived from the bronchial mucous glands are uncommon. Probably the least common variety is the oncocytomatous adenoma, this case being the second known example. The tumour was situated in the right main bronchus in a man aged 75. An oncocytomatous adenoma should be clearly distinguished from the common oncocytomatous change which affects the normal bronchial mucous gland cells seen in adults. The eosinophilic, columnar tumour cells seen by light microscopy contained numerous and prominent mitochondria by electron microscopy and granules of serous secretion. Other tumour cells contained microfilaments and were perhaps of myoepithelial origin. The true oncocytomatous mucous gland adenoma needs to be distinguished from an oncocytomatous bronchial carcinoid tumour the cells of which contain dense core granules of neurosecretory type. The bronchial oncocytomatous adenoma appears to be a benign tumour with a close similarity to its counterpart occuring in the salivary glands.
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  • 16
    Electronic Resource
    Electronic Resource
    Springer
    Virchows Archiv 393 (1981), S. 333-343 
    ISSN: 1432-2307
    Keywords: NHMI ; Pathogenesis ; Lung tumors ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Male F344 rats were given 3 mg N-nitrosoheptamethyleneimine (NHMI) per 100 g in olive oil by gavage twice a week for a maximum of 20 weeks. They were killed at predetermined intervals after the start of treatment and the sequential development of NHMI-induced squamous carcinomas in the lungs was followed by light and electron microscopy. Hypertrophy of the endoplasmic reticulum in mucous and Clara cells seen in an initial study suggested that these cells were involved in metabolic activation of the nitrosamine. Basal cells were identified as the cell type that later responded by proliferation, hyperplasia, and squamous metaplasia. Only in the bronchioles, where basal cells are not found in the healthy rat, did these lesions progress further to form squamous cell carcinomas.
    Type of Medium: Electronic Resource
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  • 17
    Electronic Resource
    Electronic Resource
    Springer
    Virchows Archiv 394 (1981), S. 31-47 
    ISSN: 1432-2307
    Keywords: Blood vessel neoplasms ; Electron microscopy ; Histochemistry ; Angiosarcoma ; Breast neoplasms
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A total of five haemangiosarcomata and two benign haemangiomas arising in the mammary gland have been studied electron microscopically and by histochemical techniques. Malignant tumors were mainly composed of endothelial cells reactive to alkaline phosphatase and adenosine triphosphatase, and of pericytes and undifferentiated mesenchymal elements. A juvenile haemangioma showed a more structured wall with an increase of endoplasmic reticulum and filaments, and a diminution of membrane modulations and rod-like tubular bodies. A cavernous haemangioma showed an ultrastructure very similar to normal vessels. The ultrastructural and histochemical data suggest a blood vessel origin of mammary angiosarcomas and show that vascular neoplasms of the breast, benign or malignant, are composed of a combined proliferation of the different cell types present in the vessel wall, as described in other organs.
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  • 18
    ISSN: 1432-2072
    Keywords: Rat ; Hippocampus ; Dopaminergic receptors ; Apomorphine ; Haloperidol ; Memory consolidation ; Brightness discrimination
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Post-training intrahippocampal injection of the dopaminergic agonists apomorphine and ergometrine improved retention in a brightness discrimination task. The dopamine receptor blocker haloperidol caused an impairment of retention and antagonized improvement by apomorphine. An involvement of hippocampal dopaminergic mechanisms in memory consolidation processes was suggested.
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  • 19
    ISSN: 1432-2072
    Keywords: Hippocampal units ; Cortical EEG ; Ethanol ; Adrenergic antagonists ; GABAergic antagonists ; Cholinergic agonists ; Dopaminergic agonists ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The spontaneous activity of single unit populations in the dorsal hippocampus and the cortical EEG were monitored in the awake rat. Experiments consisted of three consecutive recording periods; a drug-free baseline period, a pretreatment period and an ethanol period. Pretreatment with doses of dopaminergic or cholinergic agonists, which produced decreases in unit rate and an awake EEG attenuated the inhibitory effect of ethanol on hippocampal unit activity and reduced the amount of high-amplitude, slow (HAS), drowsy-state activity. GABAergic and adrenergic antagonists, which increased hippocampal unit rate, did not attenuate and sometimes enhanced the ethanol-induced inhibition in firing rate but had little additional effect on the EEG. These results point to the involvement of hippocampal neurons in those behavioural aspects of ethanol intoxication mediated by activity in the neurotransmitter systems examined here.
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  • 20
    ISSN: 1432-2072
    Keywords: Postnatal treatment ; Haloperidol ; Apomorphine ; Stereotyped behaviour ; Locomotion ; Learning ; DOPAC ; HVA ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Rats were administered 0.5 mg/kg SC of haloperidol (H) or saline (S) daily from day 1 after birth until 20 days of age. At 60 days of age (40 days after the postnatal treatment with H or S was interrupted) the stereotyped behaviour and the effects on locomotor activity elicited by apomorphine in S- and H-pretreated rats were investigated. The intensity of apomorphine (0.5–1 mg/kg, SC)-induced stereotyped behaviour was significantly greater in the H-pretreated group than in S-pretreated animals and this was accompanied by a much more marked reduction of locomotor activity in H-pretreated than in S-pretreated rats. Finally, at 80 days of age (60 days after the postnatal treatment with H or S was interrupted) rats were subjected to a Differential Reinforcement of Low Rates schedule (DRL 15-s). The results indicate that the acquisition of the DRL task performance criterion (Rs/Rf≤2.5) was significantly more rapid in S-pretreated rats than in H-pretreated ones. In parallel biochemical experiments, acute H produced smaller increases in dopamine turnover in chronic H-treated rats compared with S-treated controls. These data indicate that H treatment in neonatal rats induces behavioural and biochemical changes which can be observed up to 60 days after H withdrawal.
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  • 21
    Electronic Resource
    Electronic Resource
    Springer
    Psychopharmacology 74 (1981), S. 374-378 
    ISSN: 1432-2072
    Keywords: Lithium ; Li+ disposition ; Na+-dependent Li+ countertransport process ; Guinea-pig ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Rats or guinea-pigs were given LiCl acutely (2 mmol/kg IP or intragastrically) or chronically (daily doses 0.6–4 mmol/kg) and plasma, erythrocytes, kidney, liver and brain were analysed for Li+. Generally, after acute LiCl, tissue Li+ levels followed changes in plasma Li+ levels. However, brain Li+ concentrations changed more slowly and in the rat, but not in the guinea-pig, paralleled erythrocyte Li+ concentrations. Li+ was absorbed more slowly from the gastrointestinal tract of the rat. After chronic LiCl, the erythrocyte: plasma Li+ ratio was about 0.1 in the guinea-pig and about 2 in the rat. Relative Li+ tissue concentrations were as follows: guinea-pig, plasma〉kidney〉liver〉brain〉 erythrocyte; rat≫erythrocyte=brain〉liver=plasma. A Na+-dependent Li+ efflux was demonstrated in the erythrocytes of the guinea-pig and human, but not the rat. This process was inhibited by phloretin (0.2 mM), but not frusemide (2.0 mM). The marked differences in the activity of the erythrocyte Na+-dependent Li+ countertransport process in the guinea-pig and rat could extend to other tissues and explain the observed interspecies differences in tissue Li+ distribution.
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  • 22
    Electronic Resource
    Electronic Resource
    Springer
    Psychopharmacology 75 (1981), S. 132-133 
    ISSN: 1432-2072
    Keywords: Morphine tolerance ; Log-dose/response curve flattening ; Naloxone prevention ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Male wistar rats, previously made tolerant to morphine by at least 3 weeks of daily intraperitoneal (IP) injections of 20 mg/kg morphine-SO4 (MS), were then given 200 mg/kg MS daily for 4 or 5 days. Tail immersion tests of antinociception, carried out before and after the 200 mg/kg MS treatment, indicated that the additional morphine treatment was followed by a large further decrease in opiate sensitivity, characterized by decreased slope of the log-dose/response curve (LDR curve flattening). The further decrease in opiate sensitivity was substantially reduced by naloxone-HCl (IP) in a dose of 10 mg/kg given 30 min before and 8 h after the 200 mg/kg MS injections, or a dose of 4 mg/kg given 45 min after the MS. It was concluded that LDR curve flattening produced by high doses of MS is mediated by specific opiate receptors, and is a true expression of a high degree of opiate tolerance in the intact rat.
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  • 23
    ISSN: 1432-2072
    Keywords: Cannabis ; catecholamines ; Hyperreactivity ; Hyperthermia ; Pimozide ; Atropine ; 6-OHDA ; Stereotypy ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The behavioral responses of the rat to an extract of Cannabis sativa were examined after IP injection of 5, 15 and 30 mg/kg (expressed as Δ 9 tetrahydrocannabinol). The lowest dose of the extract induced stereotyped behavior (rhythmic head movements, intermittent gnawing and sniffing) together with hypersensitivity to stimuli and hyperthermia. The administration of higher doses of the extract resulted, initially, in similar behavioral effects but of greater intensity, followed by a cataleptic state alternating with atonic muscular prostration; rectal temperature was decreased. Pre-treatment with 6-hydroxydopamine (6-OHDA, which produces degeneration of catecholamine-containing nerve terminals) or pimozide (blocker of dopamine receptors) significantly reduced both stereotypy and hyperreactivity. Thermic effects were also antagonized by 6-OHDA pre-treatment. Cannabis-induced catalepsy was enhanced by pimozide but reduced by atropine (3 mg/kg SC). These results support the hypothesis that catecholamines play an important role in the complex behavioral effects of cannabis.
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  • 24
    Electronic Resource
    Electronic Resource
    Springer
    Psychopharmacology 74 (1981), S. 275-279 
    ISSN: 1432-2072
    Keywords: Animal model ; Tremor intensity ; Quantification ; Physostigmine ; Atropine ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract A simple and accurate device for recording tremor intensity in unanaesthetized and unrestrained rats is described. The physical measures of tremor are shown to have several advantages over previous devices. First, the new apparatus, unlike some earlier ones, does not restrict the animal's movements to an unusually small cage, with weighty mechanical devices or with electrical leads. Second, most earlier methods for measuring tremor use a subjective rating scale. However, the present method uses objective and reliable measures. In a double-blind, illustrative experiment involving complete crossover, Wistar rats were randomly injected IP with physostigmine in doses of 0.2, 0.4, 0.6 and 0.8 mg/kg or the corresponding amount of 0.9% NaCl solution as control. The recorded tremor intensity showed a clear dose-response relationship for physostigmine. Moreover, linear regression of the dose-response relationship showed that tremor intensity increased linearly with increasing doses of physostigmine. The cholinergic antagonist atropine (0.3 mg/kg SC) antagonized physostigmine-induced tremor, whereas methylatropine (0.3 mg/kg SC) tended to potentiate it. These results show that the technique described is suitable for quantification of tremor intensity in rats and for testing drug interactions on physostigmine-induced tremor.
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  • 25
    ISSN: 1432-2072
    Keywords: Superior colliculus ; Oral stereotypy ; Picrotoxin ; Reactivity ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Lesions of the superior colliculus in rats attenuate the oral stereotypy produced by systemic administration of dopamine agonists. Current evidence suggests that such drugs affect the superior colliculus by reducing transmission in the inhibitory GABAergic nigrotectal pathway. To investigate whether the superior colliculus plays a direct role in producing stereotyped oral movements, the present experiment therefore examined the effects of collicular microinjections of the GABA antagonist picrotoxin on the behaviour of rats observed in an open-field. Gnawing was observed after injections of picrotoxin (25 ng) into sites in the intermediate and deep layers of the superior colliculus, consistent with the superior colliculus playing a direct part in producing the stereotyped gnawing seen after systemic administration of dopamine agonists. However, gnawing was only observed after a period in which the animal showed strong avoidance reactions, to stimuli that normally evoked orienting or little reaction. This change in reactivity was observed after injections of picrotoxin into all parts of the colliculus, but the most sensitive (responding to doses as low as 12.5 ng) were mainly in the superficial and intermediate layers. It appears that there may be more than one GABAergic system within the superior colliculus.
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  • 26
    ISSN: 1432-2072
    Keywords: 6-Hydroxydopamine ; Sensorimotor deficits ; Superior colliculus ; Picrotoxin ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Anatomical and biochemical investigations have suggested that GABA transmission in the superior colliculus consequent upon activity of the nigrotectal pathway is increased following 6-hydroxydopamine (6-OHDA) lesions of the ascending dopamine systems. Moreover, it has been proposed that this increase in inhibitory activity within the colliculus may be responsible for the sensory neglect commonly observed after dopamine denervation. The present experiment sought to test this proposal by examining the effects of injections of the GABA antagonist picrotoxin into the superior colliculus of 6-OHDA lesioned rats, in the hope that the neglect caused by the 6-OHDA would be reversed. However, in 33 of 36 cases studied intracollicular microinjections of picrotoxin produced no detectable improvements in orientation to sensory stimuli, although a wide range of other behavioural effects was observed. These included stereotyped exploratory movements (e.g. head waving, walking, sniffing and rearing) similar to those produced in the 6-OHDA treated rats by systemic injection of apomorphine (0.1 mg/kg). These data indicate that 6-OHDA lesions of substantia nigra and ventral midbrain areas do not produce sensory neglect simply by increasing GABA transmission within the nigrotectal pathway. Instead, such an increase in nigrotectal activity may impair production of particular kinds of movement, possibly related to exploratory behaviour.
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  • 27
    ISSN: 1432-2307
    Keywords: Labial salivary gland biopsy ; Gougerot-Sjögren's syndrome ; Clinico-pathology ; Histoenzymology ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary 119 cases of Sjögren's syndrome are described. Clinically, the female sex predominates (83% of cases); the average age is 56 years. Isolated sicca syndrome is noted in 31 % of cases; it is more often associated with rheumatoid polyarthritis (64%) or with another collagen disease (5%). In addition, in 5 patients, we have found a malignant lymphoproliferative disease in an accessory or a main salivary gland (4 non-Hodgkin malignant lymphomas, 1 chronic lymphoid leukaemia). In all cases, a biopsy from accessory labial glands or from a main salivary gland, corroborates the diagnosis. Histologically, epi-myoepithelial islets are always lacking in accessory glands. We classified labial gland injuries in three groups based on striated duct distention: first, some tubular ectasia with interstitial lymphoid cells; second, much ectasia associated with many lymphoid cells and the beginning of pericanalar sclerosis; third, intensive ectasia, scarce lymphocytes, severe peri- and intralobular sclerosis and extensive destruction of acini. This grading is positively correlated with that of parotid biopsies and also with abnormalies on numerous parotid sialographic radiograms performed simultaneously. The histoenzymological study demonstrates decreased activity of oxydative enzymes in striated duct epithelia and of ATPases in myoepithelial cells. The ultrastructural study confirms these findings. Even at an early stage of the disease, tubular alterations are observed: epithelial cell degeneration (vacuolated mitochondria, loss of cytoplasmic lateral membrane foldings) and myoepithelial cell damage (in particular disappearance of myofilaments). These findings explain tubular ectasia by the loss of contractile function. Simultaneously, intensive regeneration from the intercalated ducts by young “totipotent” cells, sometimes differentiating into epidermoid, secretory or myoepithelial cells, are observed. Lesions in acinar cells are less marked: conglomeration of secretory granules, some autophagosomes and rarely true necrosis. In the interstitial tissue, amongst lymphocytes, plasmocytes and mastocytes, numerous myoepithelial cells are present: young pseudo-fibroblastic cells with poor ergastoplasm and some myoid organelles (a few myofilaments, dark zones and endocytosis vacuoles on cell membrane; degenerated myoepithelial cells whose scanty dark cytoplasm is filled with lipid droplets). Thus, by analogy with the myoepithelial islets observed in parotid biopsies, the myoepithelial cell damage seems to have a specific signification in Sjögren's disease. Regeneration from the intercalated ducts fails to repair these cells and to restore their physiological contractile function. Furthermore, this leads to extratubular migration of young myoid cells which are responsible for progressive accumulation in the interstitial tissue of membranoid material and later collagen sclerosis.
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  • 28
    ISSN: 1434-0879
    Keywords: Dog prostate ; Stereological analysis ; Electron microscopy ; Oestrogen effect
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The stromal tissue of the prostate in normal castrated dogs and castrated and oestrogen treated dogs were studied by quantitative morphological methods. Quantitative morphological (=stereological) procedures provide values of volume, surface and number of tissue and cell components. The stereological data show an activation of the smooth muscle cell of the stromal tissue in the oestrogen treated dog compared with the control group; related to the unit volume of smooth muscle cell cytoplasm, a threefold increase of the endoplasmic reticulum was observed in castrated and oestrogen treated dogs.
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  • 29
    ISSN: 1433-8580
    Keywords: Stimulator ; Macrophages ; Rat ; Esberitox
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The influence of a preparation (Esberitox) which is claimed to be a non-specific stimulator of host resistance was examined in macrophages attaching to s.c. implanted coverslips in rats. Not only did this preparation significantly increase macrophage numbers but it also very significantly increased the proportion which were stimulated.
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  • 30
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    Research in experimental medicine 179 (1981), S. 269-274 
    ISSN: 1433-8580
    Keywords: Rat ; Alkaline phosphatase isoenzyme in serum and liver homogenate ; Cholestasis ; Bile duct ligation ; Intoxication with: ANIT, CCL4, phenobarbital
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Alkaline phosphatase isoenzymes (API) in serum of rats during cholestasis are investigated. For comparison different membrane systems in liver are damaged. Proliferation of bile canaliculi, sinusoidal area, and endoplasmic reticulum, respectively, is induced by different toxic conditions. It is found that in cholestasis an API5 in serum arises which is not present in serum of normal rats, but can be detected in normal rat liver. Thus, it is not a de novo synthesis of this API. Under the condition connected with a proliferation of bile canaliculi we find this API5 in serum. Under different conditions without proliferation of bile canaliculi we do not find an increase of this API5. We assume, therefore, that API5 in cholestasis is produced by cells of the bile canaliculi rather than by liver parenchymal cells in the sinusoidal area. No difference is found in intra- or extrahepatic cholestasis.
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  • 31
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    Research in experimental medicine 178 (1981), S. 165-175 
    ISSN: 1433-8580
    Keywords: Perfused rat pancreas ; Insulin secretion ; Uric acid ; Light microscopy ; Electron microscopy ; Rattenpankreasperfusion ; Insulinsekretion ; Harnsäure ; Lichtmikroskopie ; Elektronenmikroskopie
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Es ist bekannt, daß die Methylxanthine Coffein und Theophyllin die Insulinsekretion positiv beeinflussen. Im Rahmen von Perfusionsversuchen sollte untersucht werden, ob die Inselzellfunktion auch dem Einfluß der chemisch eng verwandten Harnsäure unterliegt. Zugleich sollte eine Destruktion von Inselzellstrukturen durch Harnsäure ausgeschlossen werden, da die chemisch ähnlich configurierte Substanz Alloxan bekanntlich Inselzellnekrosen verursacht. Dazu wurden isolierte Rattenbauchspeicheldrüsen mit Glukosekonzentrationen von 100 mg/100 ml und 300 mg/100 ml stimuliert. In einem Teil der Fälle wurde dem Perfusat Harnsäure in der Konzentration von 12 mg/100 ml zugegeben. Es zeigte sich, daß Harnsäure die Insulinsekretion bei Stimulation mit Glukose in der Konzentration von 100 mg/100 ml nicht beeinflußt. Werden die B-Zellen jedoch mit einer Glukosekonzentration von 300 mg/100 ml stimuliert, so steigert Harnsäure die Hormonfreisetzung im Sinne eines glukosepotenzierenden Effektes um mehr als 100%. Anhand charakteristischer Sekretionsphänomene sowie lichtoptischer und elektronenmikroskopischer Untersuchungen konnte nachgewiesen werden, daß es sich hierbei um eine echte Mehrsekretion handelt und nicht etwa um einen Auslaufeffekt als Folge einer Destruktion von Inselzellstrukturen durch eine alloxanähnliche Wirkung der Harnsäure.
    Notes: Summary Methylxanthines, such as caffeine and theophylline, show effects increasing the secretion of insulin. Perfusion experiments were intended to find out whether insulin secretion is even influenced by uric acid, which is chemically closely related. Besides, it was to be demonstrated that uric acid causes no damages to islet cell structures for it is well established that alloxan, which is chemically related to uric acid, produces necroses in B cells. Isolated rat pancreata were stimulated by glucose at concentrations of 100 mg/100 ml and 300 mg/100 ml. In part of the experiments uric acid was added to the perfusion medium at a concentration of 12 mg/100 ml. We found that uric acid has no influence on insulin secretion if it is stimulated by glucose at a concentration of 100 mg/100 ml. However, if B cells are stimulated by glucose at a concentration of 300 mg/100 ml insulin secretion is enhanced by the addition of uric acid by more than 100%. This indicates that this substance exhibits a glucose-potentiating effect. The characteristic dynamics of insulin secretion demonstrate together with light- and electron-microscopic investigations that uric acid causes a real additional secretion and no leaking of intracellular insulin as a result of destruction of islet cell structures by an effect of uric acid similar to that of alloxan.
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  • 32
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    Acta neuropathologica 54 (1981), S. 203-210 
    ISSN: 1432-0533
    Keywords: Retina ; Schwann cell ; Myelinated nerve fibers ; Nodes of Ranvier ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Myelination of axons in the nerve fiber layer (NFL) of the retina occurs as a sporadic abnormality in several mammalian species including man, monkey, cat and rat. All of these species have vascularized retinae and, in the latter three, ultrastructural studies have demonstrated the pattern of medullation to be similar to Schwann cell myelination in the peripheral nervous system. This contrasts with an oligodendrocytic pattern of myelination normally present in the avascular retina of the rabbit. One possible explanation for this difference is that the pattern of myelination is related to the presence or absence of retinal blood vessels. The present investigation provides the first evidence of NFL myelination in another avascular retina, that of the guinea pig. Myelination in the guinea pig retina was observed in a single bundle of axons and involved only large diameter fibers. With several axons, myelin sheaths terminated at hemi-nodes of Ranvier and in all such cases this occurred in association with marked paranodal infolding. Morphological characteristics of the myelination include (1) a one to one relationship between axon and myelinating cell, (2) cytoplasm between myelin sheath and plasma membrane, (3) basal lamina surrounding the myelinating cell, (4) collagen fibers in the adjacent extracellular space and (5) double intraperiod lines. These morphological features are characteristic of peripheral nerve myelination by Schwann cells. Thus, in all species so far described in which retinal medullation is abnormally present, the pattern of myelination has been Schwann cell in nature rather than oligodendrocytic. The reasons for this Schwann cell predominance remain undefined.
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  • 33
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    Acta neuropathologica 54 (1981), S. 233-237 
    ISSN: 1432-0533
    Keywords: Methylmercury ; Mice ; Golgi methods ; Electron microscopy ; Dendrites ; Purkinje cells ; Perivascular glia
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Neonatal C57BL/6J mice were injected with 5 mg/kg body weight of203Hg-labeled methylmercuric chloride on postnatal days 3, 4, and 5, totaling 15 mg/kg body weight per animal. The experimental and control animals were sacrificed on postnatal day 15. Whole body radioactivity of203Hg progressively increased during the 3-day injection period and reached the peak level and remained at peak levels until the time of sacrifice. This indicates a lack of clearance of203Hg by neonatal mice during the period examined in this study. Golgi preparations of cerebella of MeHg-treated animals revealed significant reduction in dendritic arborization of Purkinje cells. Ultrastructurally, the vascular endothelium showed attenuation with increased electron density and frequent vacuolization of cytoplasm. Marked swelling of perivascular glia was noted in most of the capillaries throughout the cerebella of MeHg-treated animals.
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  • 34
    ISSN: 1432-0533
    Keywords: Phrenic nerve ; Diaphragm muscle ; Rat ; Streptozotocin diabetes ; Morphology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary One year after beginning of the experiment six streptozotocin-injected Wistar rats and six controls were anesthetized and fixed by whole-body perfusion. The diaphragms were isolated and processed for light and electron microscopy. Both the intramuscular branches of the phrenic nerve and the muscle fibers were studied morphologically and morphometrically. Moreover, two diabetic and two control rats were killed by decapitation, the diaphragms were deep-frozen and studied histochemically for myofibrillar ATP-ase. A significant reduction of fiber cross section surface, due to reduction of both myelin and axon surfaces, was found in the phrenic nerves of diabetics. Lesions of Schwann and mesenchymal endoneural cells were the main ultrastructural changes. The diaphragm was much thinner in diabetics than in controls. In diabetics the number of lipid droplets found in red muscle fibers was increased and the white muscle fibers were hypotrophic. These findings were confirmed by the morphometric study. Ultrastructurally, various types of lipid droplets, streaming of Z line, organelle degeneration, invagination of nuclear membrane, and increase in number of satellite cells were found in red fibers of diabetic animals. Disorientation of the triads was the most frequent lesion in white fibers of diabetics. These results demonstrate that both neuropathy and myopathy are present in functionally related nerve and muscle from rats after 12 months of streptozotocin-induced diabetes. Both the dysmetabolic condition and the nervous lesions may have contributed to the muscular changes.
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  • 35
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    Acta neuropathologica 55 (1981), S. 77-80 
    ISSN: 1432-0533
    Keywords: Esthesioneuroepithelioma ; Olfactory neuroblastoma ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A rare case of esthesioneuroepithelioma infiltrating the right frontal lobe is reported in a 41-year-old man. This tumor composed of compact lobules with tubular arrangements, ultrastructurally showed two different cell types, both devoid of neurosecretory granules and reminiscent of neurons and sustentacular cells of the olfactory epithelium. These features are distinguished from those generally observed in olfactory neuroblastomas.
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  • 36
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    Acta neuropathologica 55 (1981), S. 89-95 
    ISSN: 1432-0533
    Keywords: Electron microscopy ; Morphometry ; Sorbitol pathway ; Diabetes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Galactose neuropathy is characterized by progressive endoneurial edema manifested by a gradual increase in endoneurial fluid pressure. Edema accumulates via a unique mechanism of osmotic force generated by products of the polyol pathway, synthesized within the endoneurial compartment. This paper presents morphologic findings showing firstly, that blood nerve barrier permeability to horseradish peroxidase complexes appears unchanged and secondly, peripheral nerve edema in this condition is restricted to extraganglionic endoneurium sparing the spinal ganglia and adjacent roots. Thirdly, mast cells accumulated in significant numbers and electron microscopy revealed degranulation. There was no evidence of edema in Schwann cell cytoplasm, the putative site of galactitol accumulation via the sorbitol pathway. These findings are discussed with respect to diabetic neuropathy for which galactose intoxication is a useful experimental model.
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  • 37
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    Acta neuropathologica 55 (1981), S. 167-172 
    ISSN: 1432-0533
    Keywords: Myopathy ; Pathology ; Rat ; Steroid
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The steroids triamcinolone, dexamethasone, beta-methasone, and cortisone were administered i.p. to adult rats for 14–63 days. The extensor digitorum longus (EDL, white muscle) and soleus (SOL, red muscle) muscles were examined histologically and histochemically. Triamcinolone was the most potent lesion-producing drug. Selective involvement of muscles, and of the fiber types within them was observed: Neerotic changes were seen only in the type 1 fibers of the SOL; atrophic fibers were observed in the type 2 fibers of both the SOL and the EDL.
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  • 38
    ISSN: 1432-0533
    Keywords: Postischemic recirculation ; Complete cerebral ischemia ; Ischemic neuronal injury ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The neuronal response to complete cerebral ischemia (CCI) of 5–15 min duration was evaluated at the light and electron microscopic level subsequent to postischemic recirculation periods of up to 60 min. Following postischemic reperfusion, the homogeneous neuronal changes characteristic of permanent CCI were modified into a heterogeneous pattern of selectively vulnerable neuronal responses. Four basic types of neuronal injury were represented within this heterogeneous neuronal population. The Type I neuronal response was most numerous and consisted of chromatin clumping, nucleolar condensation and a breakdown of polysomes. This response may represent a reversal of some of the neuronal changes observed after permanent CCI. In addition to the above changes, Type II neurons contained swollen mitochondria and Golgi saccules which appeared as microvacuoles under the light microscope. Type III neurons displayed varying degrees of neuronal shrinkage and numerous swollen mitochondria. Type IV neurons were markedly shrunken and electron-dense with few identifiable subcellular structures. The distribution of Type I neurons was random but the other neuronal responses occurred in “selectively vulnerable” brain regions. The number of Type II, III, and IV neurons increased with extended insult durations but were unaffected by the length of recirculation. Ten minutes of CCI represented the threshold for a significant increase in the number of severely altered neurons. These findings suggest that considerable neuronal injury may be present after 10–15 min of CCI, and the lack of a recirculation period following CCI appears to afford the brain parenchyma an extensive degree of structural protection.
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  • 39
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    Acta neuropathologica 53 (1981), S. 65-74 
    ISSN: 1432-0533
    Keywords: Hexachlorophene ; Central nervous system ; Mice ; Baboons ; Electron microscopy ; Neurotoxicology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A study on hexachlorophene encephalopathy in mice and baboons is reported. By light microscopy, a severe spongiform lesion of the central nervous system (CNS) was localized in the white matter, without myelin breakdown or cellular reaction. By electron microscopy, the myelin alteration was characterized by wide intralamellar spaces or “splitting” developed in the intraperiod line of compact sheaths. The acute changes described were induced by administration of the drug by the digestive or cutancous routes at various dosage levels in an aqueous solution or in talcum powder. The toxic effects depended on the age of the animals, the survival times and the concentrations of hexachlorophene, i.e., 6%, 3%, and 0.5%. The findings are compared with previous reports on the neurotoxicity of hexachlorophene and other chemicals in humans and experimental animals. Hexachlorophene cannot be recommended for use in young infants because of its neurotoxicity in very low doses as demonstrated in the present report.
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  • 40
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    Acta neuropathologica 53 (1981), S. 41-50 
    ISSN: 1432-0533
    Keywords: Giant axon swellings ; Rat ; Drug-induced lipidosis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary This study is concerned with the structure and topographic distribution of axonal alterations in the area postrema and in several adjacent nuclei of adult rats treated with different lipidosis-inducing drugs. The effects of three compounds (chloroquine, quinacrine, perhexiline) that seem to be largely excluded from most parts of the brain except circumventricular organs were compared with a reference compound (chlorphentermine) that has general access to the brain of adult rats. Only chlorphentermine caused generalized axonal alterations (intra-axonal accumulation of polymorphous osmiophilic materials, giant axonal swellings) in all inspected nuclei (area postrema, nucleus gracilis, nucleus tractus solitarii, nucleus nervi hypoglossi, nucleus dorsalis nervi vagi), with nucleus gracilis possessing the most vulnerable axons and axon terminals. The axonal effects of chloroquine were severe only in area postrema and in the closely adjacent neuropil of nucleus gracilis and nucleus tractus solitarii, whereas in the remaining regions axonal alterations were either moderate (lateral portions of nucleus gracilis) or absent. Axonal effects of quinacrine and perhexiline were confined to area postrema. The findings suggest that the topography of the severe axon alterations is greatly dependent on drug distribution. It is concluded that two factors have generally to be considered as responsible for the giant axon swellings found after application of lipidosis-inducing drugs: (a) local drug action upon the axon itself, and (b) lysosomal overloading in the corresponding perikaryon, with factor (a) probably being more potent than factor (b).
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  • 41
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    Acta neuropathologica 53 (1981), S. 99-106 
    ISSN: 1432-0533
    Keywords: Peripheral nerve ; Rat ; Streptozotocin diabetes ; Morphometry ; Morphology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary One year after beginning of the experiment seven streptozotocin-injected Wistar rats and seven controls were fixed by whole-body perfusion, the nervus radialis was dissected and processed for light and electron microscopy. After light-microscopic study standard photographs of nerve cross sections were measured by means of a semiautomatic image analyzer. The following measurements were obtained: (1) surface of fibers, axons, and myelin sheaths; (2) ratio of myelin to axon surface; and (3) percent of endoneural space. Group means and standard errors were calculated, and cumulated class distributions were made. Ultrathin sections from all animals considered morphometrically were studied qualitatively for ultrastructural changes. The quantitative study revealed in the diabetics reduction of average myelin surface, increase of endoneural space, and reduction of myelin/axon ratio. The main ultrastructural findings were lesions of Schwann and mesenchymal cells, followed by less frequent and less severe changes in axons and endothelium. These results suggest a primary Schwann cell lesion was responsible for the observed myelin reduction.
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  • 42
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    Acta neuropathologica 53 (1981), S. 165-168 
    ISSN: 1432-0533
    Keywords: Lewy body ; Neurofibrillary tangle ; Locus ceruleus ; Aged brain ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The presence of Lewy body and neurofibrillary tangle in the locus ceruleus neurons of aged brain is described. Ultrastructural study revealed that in some Lewy bodies the presence of “twisted tubules” or “paired helical filaments” amongst the filaments of the Lewy body. A quantitative analysis of serial sections of locus ceruleus from aged brain, incidences of the Lewy body and neurofibrillary change were 0.07% (9/11,515) and 6.6% (15/11,515), respectively. The incidence of neurons containing both structures was 0.008% (1/11,515).
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  • 43
    ISSN: 1432-0533
    Keywords: Fetal alcohol syndrome ; Rat ; Liquid diet ; Cerebellum ; Purkinje cells ; Rough endoplasmic reticulum ; Metabolism
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Alcohol was administed in a vitaminsupplemented liquid diet (Stardit) to Wistar rats 4 weeks before mating and during pregnancy. Of the daily calories 38–40% were supplied by alcohol and by isocaloric sucrose in the controls. Offspring of alcohol drinking dams showed a reduced birth weight and gained weight less rapidly than the controls. On day 3, 4, 7, 12, 17 and 21, experimental animals and controls were perfused for histological and electron microscopic investigations. Morphometric analysis of the cerebella (Fol. 5 and Fol. 8) showed no difference in the number of Purkinje cells. However, on day 7 the Purkinje cell nuclei of experimental pups were significantly smaller. This difference disappeared at day 12. Electron microscopic investigations in the 4, 7, and 12 days old experimental animals revealed a delayed cytoplasmic maturation of Purkinje cells which mainly involved the rough endoplasmic reticulum. At 17 days, there was no difference between the two groups. These data are discussed in relation to alcohol-induced metabolic changes in the brain.
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  • 44
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    Acta neuropathologica 54 (1981), S. 43-53 
    ISSN: 1432-0533
    Keywords: Uremia ; Kidney transplantation ; Polyneuropathy ; Light microscopy ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Eighteen patients, ten with clinical uremia and eight with functioning kidney transplants, were studied clinically for neuropathy and were subsequently subjected to a sural nerve biopsy. The biopsy specimens were studied using light and electron microscopic and morphometric methods. The clinical polyneuropathy was qualitatively and quantitatively most severe in the hemodialysis group. These results conformed with the light and electron microscopic observations. Clinical, morphological and morphometric indications of recovery from uremic neuropathy were observed in the transplant recipients. The pathophysiology of uremic peripheral neuropathy was marked axonal degeneration. Pathologic Schwann cells were also frequently found. Axonal degeneration and Schwann cell damage seemed to exist independently of each other. In morphometric analysis, axonal atrophy and abnormal myelin sheath thickness were observed in all patient groups. A close relationship was found between axonal atrophy and low conduction velocity. Unexpectedly low nerve conduction velocities were also observed, which cannot be explained by either loss of nerve fibers or demyelination. The findings of damaged endoneural blood capillaries supported the ischemic theory as one mechanism in the pathogenesis of uremic neuropathy.
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  • 45
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    Acta neuropathologica 54 (1981), S. 129-134 
    ISSN: 1432-0533
    Keywords: Peripheral nerve ; Rat ; Streptozotocin diabetes ; Morphometry ; Morphology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Eight streptozotocin-injected Wistar rats and eight controls were fixed by whole-body perfusion 4 months after beginning of the experiment, the nervus radialis was dissected and processed for light and electron microscopy. After light-microscopic study standard photographs of nerve cross sections were measured by means of a semiautomatic image analyzer. The following measurements were obtained: (1) surface of fibres, axons, and myelin sheaths, (2) ratio of myelin to axon surface, and (3) percent of endoneural space. Group means and standard deviations were calculated, and cumulated size class distributions were made. Representative nerve specimens from all animals were also studied by electron microscopy. The quantitative study revealed in the diabetics a severe reduction of the average myelin surface, a mild increase of axonal cross section and of endoneural space, a reduction of myelin/axon ratio and a mild reduction in cross section of the nerve. Ultrastructural lesions of minor degree were found in the cytoplasm of Schwann and mesenchymal cells, no lesion was observed in axons. These findings demonstrate the presence of neuropathy 4 months after induction of diabetes and support the pathogenetic role of the Schwann cell in our experimental model.
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  • 46
    ISSN: 1432-0568
    Keywords: Silver staining ; Neurons ; Nucleolus ; Supraoptic nucleus ; Hypothalamus ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The present paper describes a simple, efficient method for silver impregnation of supraoptic nuclei of the rat hypothalamus using a modification of the ammoniacal silver technique of Cajal (1903). This procedure, involving a silver-developer sequence in tissue blocks prior to plastic embedding, permits the simultaneous study of Ag-impregnated supraoptic neurons at both light and electron microscopic levels. Visualization of secretory magnocellular neurons impregnated by this technique using the electron microscope reveals a good preservation of nuclear structures. A selective accumulation of silver grains was observed over heterochromatin clumps and nucleoli, which allows the identification of the nucleolar fibrillar centers and also the dense fibrillar component as the main areas involved in the silver reaction. The meaning of such a silver-distribution pattern is discussed in the light of recent ultrastructural and biochemical data.
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  • 47
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    Anatomy and embryology 163 (1981), S. 71-75 
    ISSN: 1432-0568
    Keywords: Visual cortex ; Development ; Projections ; Layer I ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The development of the thalamic afferent projections to layer I of the visual cortex of the albino rat was studied using the retrograde transport of horseradish peroxidase. The results show that the projections to layer I which arise in the “nonspecific” thalamic nuclei (lateral posterior nucleus, posterior complex and ventromedial nucleus) develop earlier than the projection from the “specific” nucleus (dorsal lateral geniculate nucleus).
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  • 48
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    Anatomy and embryology 161 (1981), S. 419-431 
    ISSN: 1432-0568
    Keywords: Nuclei habenulae ; Biomathematical Analysis ; Fresh Volume ; Rat ; Spontaneous Nerve Cell Degeneration
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The growth of the nuclei habenulae medialis et lateralis of albino rats is described by monotonically increasing growth curves of fresh volumes during ontogenesis. The nucleus habenulae medialis matures earlier than the nucleus habenulae lateralis in the perinatal period. However, the two nuclei reach their final volume at about the same time. Simultaneous electron microscopic investigation reveals the phenomenon of spontaneous nerve cell degeneration within the nuclei habenulae during ontogenesis in spite of the non-overshooting growth curves for the habenular nuclei.
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  • 49
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    Anatomy and embryology 161 (1981), S. 433-451 
    ISSN: 1432-0568
    Keywords: Rhombencephalon, rat ; Subependymal cysts ; Morphogenesis ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A bilaterally symmetrical cystic cavity is situated in the subependymal neuropil of the rostral rhombencephalon of the rat during the perinatal period of ontogeny. These cysts are formed by the confluence of enlarged extracellular spaces in this region between E18 and E20. The cysts are present for about 2 weeks but disappear on about P15 without trace. They have a maximal volume of about 0.004 to 0.006 mm3 on P2, with a rostrocaudal extension of about 200 μm. Their shape is characterized by a medial convexity and a lateral concavity, and they have their maximal circumference at about the middle of the rostrocaudal axis. The caudal portion is juxtaposed to the subependyma, while the rostral part lies in the neuropil of the presumptive griseum centrale pontis. In the lumen and the wall of the cysts are found numerous macrophages, hlioblasts and some degenerating axons and dendrites. The significance of these cysts in the context of morphogenesis and the origin of the numerous macrophages within them are both unresolved.
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  • 50
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    Anatomy and embryology 162 (1981), S. 489-492 
    ISSN: 1432-0568
    Keywords: Visual cortex ; 6-hydroxydopamine ; Development ; Morphology ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The development of the visual cortex was examined in control rats and in littermates whose cortical noradrenergic innervation was removed with 6-hydroxydopamine. Qualitative and quantitative observations revealed no differences in the lamination, cytoarchitecture, cell density and size between the two groups of animals. These results suggest that the number, size, and distribution of cortical neurons are not significantly altered in the absence of noradrenergic afferents.
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  • 51
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    Archives of dermatological research 271 (1981), S. 275-282 
    ISSN: 1432-069X
    Keywords: Percutaneous absorption ; Griseofulvin ; Proquazone ; Rat ; Human skin ; Percutane Absorption ; Griseofulvin ; Proquazon ; Ratte ; menschliche Haut
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Salben mit Griseofulvin respektive Proquazon wurden aus Monoglyceriden mittlerer Kettenlänge und einem aprotischen Lösungsmittel, Glycerinformal, hergestellt und auf dem Rücken von Gallefistelratten appliziert. Die percutan resorbierten Mengen sowie die Permeabilitätskonstanten sind für beide Wirkstoffe wesentlich höher nach Applikation der Salben als nach Applikation von einfachen Wirkstofflösungen ohne Monoglyceride. Die Verteilung der markierten Wirkstoffe in Rattenhaut wurde durch Mikroautoradiographie kontrolliert. Die Konzentrationen der Wirkstoffe in den einzelnen Schichten von menschlicher Haut sowie die mittleren Penetrationsraten wurden 16 h nach Applikation der Salben auf isolierte menschliche Haut bestimmt. Monoglyceride mittlerer Kettenlänge erhöhen die Permeabilität des Stratum corneum für gelöste Wirkstoffe wesentlich.
    Notes: Summary Ointments containing griseofulvin and proquazone, respectively, were made up of monoglycerides of medium chain length and an aprotic solvent, glycerinformal. The ointments were applied topically on the back of bile cannulated rats. The total amount absorbed percutaneously and the permeability constants of both drugs were considerably higher for the ointments than for simple solutions of the drugs without monoglycerides. Distribution of the labeled drugs in rat skin has been demonstrated by microautoradiography. Concentrations of the drugs in the different layers of human skin together with the medium flow rates have been determined 16h after administration of the ointments onto isolated human skin. Monoglycerides of medium chain length enhance significantly the permeability of the stratum corneum for solutes.
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  • 52
    ISSN: 1432-0584
    Keywords: Immunoprecipitation ; Immature antigens ; Mouse ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Rabbit antisera directed against erythrocytes from anemic mice or from newborn rats, once absorbed on homologous normal adult erythrocytes, recognize antigens present respectively on immature erythrocytes from anemic adult mice or rats (Im M and Im R antigens). Using iodinated immature erythrocytes from both species, homologous sera precipitated two populations of antigens showing 230,000 D and 95,000 D molecular weights. Im M antigens (230,000 and 95,000 D) were partially precipitated using anti-Im R serum. After total absorption of the sample by anti-Im R serum, both 230,000 and 95,000 D antigens were still immunoprecipitated using anti-Im M serum. Similar results were obtained using Im R antigens and anti-Im M serum then anti-Im R serum. This demonstrates that some Im specificities are common to rat and mouse while others, showing identical molecular weights, are species-specific.
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  • 53
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    Acta neuropathologica 53 (1981), S. 237-248 
    ISSN: 1432-0533
    Keywords: Thyroxine effect on muscle ; Histochemistry ; Immunopathology ; Electron microscopy ; Diagnostic muscle pathology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Proximal myopathy and different types of neuromuscular syndromes are frequently observed in hyperthyroid patients with complicated thyrotoxicosis. Conflicting reports on the changes seen in muscle biopsies range from no abnormalities to muscle necrosis with the fibers being replaced by connective tissue and fat. On the basis of 21 skeletal muscle biopsies from chronic thyrotoxic myopathic patients, coupled with studies in experimentally induced triiodothyronine myopathy in rats, the histological, histochemical, immunofluorescent, and electron-microscopic findings diagnostic for thyrotoxic myopathy are defined. These criteria include: clumping of nuclei, los of cross-striation, vacuolar degeneration, and fatty infiltration of endo- and perimysium, presence of giant mitochondria, increased number of mitochondria, disorganization of contractile elements, swelling of transverse tubules, presence of microtubular aggregations, and a significant increase of lipofuscin granules. Both muscle fiber types or in some cases selective type II fibers display atrophy with signs of reinnervation. These alterations are polyfocal and polyphasic and, therefore, polychronous and stereotyped rather than pathognomonic. However, they are related to the severity of thyrotoxic myopathy and the duration of disease. The results of muscle biopsies have a predictive value in determining the reversibility or irreversibility of pathologic changes with therapeutic consequences.
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  • 54
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    Acta neuropathologica 53 (1981), S. 267-273 
    ISSN: 1432-0533
    Keywords: Rat ; Neck muscles ; Motoneurons ; Dendrites ; HRP
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The nuclei for the nerves of a dorsal (m. splenius) and a ventral (m. longus capitis) neck muscle of the rat were retrogradely labeled by applying horseradish peroxidase (HRP) to the respective cut muscle nerves. Motoneurons of both muscles were analyzed for their localization, diameter of perikarya, and area of dendritic arborization. The nucleus of m. longus capitis is situated dorsomedially, the nucleus of m. splenius ventromedially within the ventral horn. Thus, the relative positions of the two nuclei are inverse to those of their muscles, with the more ventral nucleus innervating the more dorsal muscle. In both nuclei the areas of dendritic arborization are very large, extending into the nuclei of other neck muscles, and also into the ipsilateral anterior funiculus. In addition, m. longus capitis motoneurons were found to send dendrites into the contralateral ventral horn, reaching the nucleus of the contralateral muscle. The size distribution of perikarya is bimodal for m. longus capitis motoneurons, but only unimodal in the case of m. splenius.
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  • 55
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    Acta neuropathologica 54 (1981), S. 121-127 
    ISSN: 1432-0533
    Keywords: Rat ; Protein deprivation ; Nerve fibre degeneration ; Central nervous system ; Peripheral nervous system
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Knowledge from previous reports that kwashiorkor in man may lead to nerve fibre degeneration prompted this study on rats. The rats were subjected to severe protein deprivation from 6 weeks of age. Protein deprivation was achieved by feeding the rats ad lib with a diet containing only 1.5% protein. Control rats received an iso-caloric diet with 14% protein. The vitamin content in both diets was well above normal requirements. In relation to body weight the protein-deprived rats did not consume less food than the control rats. Protein deprivation resulted in stunted body growth, markedly reduced values of serum albumin, and changes in the fur accompanied by areas of alopecia. Furthermore, the protein-deprived rats showed degeneration of nerve fibres in the medial parts of the posterior columns of the cervical but not the sacral part of the spinal cord and nerve fibre degeneration in the distal but not the proximal parts of the longitudinal tail nerves. Teased nerve fibre preparations of the tail nerves revealed changes consistent with the Wallerian type of degeneration. It is concluded that severe protein deprivation in young rats may lead to a “dying-back” type of neuropathy in the central and peripheral nervous systems.
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  • 56
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    Acta neuropathologica 55 (1981), S. 105-111 
    ISSN: 1432-0533
    Keywords: Brain tumor ; Brain edema ; Histology ; Cytology ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In this study an experimental intracerebral tumor has been investigated with special consideration of structures, which may be involved in edema production and/or resolution. For this purpose a cloned tumor cell line (RG1 2.2) has been injected stereotactically into the brain of BD-IX rats. The tumor has some characteristics in common with low differentiated oligodendroglioma in men. A honcycomb architecture may be seen in the center of the tumor. It is built up by rounded or elongated cells, which can be impregnated in parts. In the central area, cells exhibit a volominous digestive apparatus, composed of dictyosomes, vesicles, and some vacuoles with a membranaceous or homogeneous content. Tumor cells in the periphery show large processes and a small digestive apparatus. The sinusoidal tumor vessels are composed of an endothelium with many vesicles but no openings.
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  • 57
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    Acta neuropathologica 55 (1981), S. 143-149 
    ISSN: 1432-0533
    Keywords: Pineal parenchymal neoplasm ; Electron microscopy ; Primitive neuroectodermal cell ; Dense core vesicles
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The fine structure of two pineal parenchymal neoplasms has been described. The tumors contained a predominance of small, poorly differentiated cells with prominent nuclei and scanty cytoplasm. These cells were similar to those found in medulloblastomas, primitive cerebral neuroectodermal tumors, and fetal cerebellum and cerebrum. Some cells contained 9+0 cilia, dense core vesicles, and processes containing microtubules and numerous dense core and clear vesicles, suggesting neuronal differentiation. Astrocytic elements were also present. This study suggests that the predominant cells of these tumors are primitive neuroectodermal elements which have the potential to differentiate along several different lines.
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  • 58
    ISSN: 1432-0533
    Keywords: Immunochemistry ; Pituitary adenoma ; Electron microscopy ; Mixed eosinophilic-cromophobe ; Gonadotropin ; Thyrotropin-secretion
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Twenty-nine pituitary adenomas were studied by histologic, electron-microscopic, and immunohistochemical techniques. By conventional histological stains, 19 cases were considered chromophobe, five cosinophilic, and five mixed chromophobe and eosinophilic adenomas. Immunohistochemistry, with specific antibodies against human GH, PRL, FSHβ, LHβ, and TSHβ showed, clearly, secreting and non-secreting groups of tumors: growth hormone-secreting adenomas (four cases), prolactin-secreting adenomas (eight cases), thyrotropin and/or gonadotropin-producing tumors (seven cases), and non-secreting adenomas (ten cases). Electron microscopy showed secretory granules of varying numbers, sizes, and shapes in all tumor cells in all 29 cases. The endoplasmic reticulum appeared markedly increased in 5/8 of the prolactin producing tumors; mitochondria also appeared markedly increased in 3/7 of the thyrotropin-gonadotropin group. These three cases could be considered “oncocytomas” by electron-microscopic criteria. Patients with prolactin-secreting adenomas had high serum prolactin and typical clinical symptoms associated with such tumors. One patient with large numbers of TSH-containing cells in her tumor and some cells with growth hormone and FSH had overt thyrotoxicosis. Although the remaining six tumors stained specifically for one hormone or another, no clinical correlation was possible. Conventional electron microscopy has some value in the generic identification of puritary tumor cells, but no value in the recognition of specific secretory products or specific cell types. Conventional histopathology is the least reliable method to correctly identify a specific type of pituitary adenoma, beyond the identification of the adenomatous changes. This study demonstrates the existence of gonadotropin- and/or thyrotropin-secreting pituitary adenomas, among so-called chromophobe adenomas, or “undifferentiated adenomas”.
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  • 59
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    Acta neuropathologica 55 (1981), S. 307-318 
    ISSN: 1432-0533
    Keywords: Diphtheritic polyneuropathy ; Muscle biopsy ; Intramuscular nerves ; Electron microscopy ; Histochemistry ; Diphtherie-Polyneuropathie ; Muskelbiopsie ; intramuskuläre Nerven ; Elektronenmikroskopie ; Histochemie
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Biopsien aus Extremitätenmuskeln von vier Kranken mit schwerer tetraplegischer Form der Diphtherie-Polyneuropathie konnten nahe dem Höhepunkt der Erkrankung gewonnen und mit modernen Methoden einschließlich Histochemie, Elektronenmikroskopie und morphometrischer Verfahren untersucht werden. Vergleichbare Studien wurden bisher nicht veröffentlicht. Die Muskulatur bot vorwiegend neurogene Veränderungen mit disseminierten angulierten Fasern, eine besonders die Typ-2B-Fasern betreffende, mehr generaliierte Atrophie sowie Targetoidherde oder „Cores” in Typ-1-Fasern. Darüber hinaus fanden sich eindeutige myogene Veränderungen mit unterschiedlichen Degenerationsphänomenen bis zur totalen Nekrose, offenbar — wie am Herzmuskel —toxischer Herkunft. Das neurogen-myogene Mischbild entsprach den elektromyographischen Befunden. Die intramuskulären Gefäße waren unauffällig bis auf vereinzelte perivaskuläre, vorwiegend mononukleäre Zellinfiltrate mit reichlich zerebriformen lymphoiden Zellen, wahrscheinlich T-Lymphozyten. An 11 intramuskulären Nerven und zwei motorischen Endplatten waren eindeutig auf die Diphtherie zu beziehende Veränderungen nicht aufzudecken. Dies kann als Hinweis auf eine vorwiegend proximale Entmarkung bei der Diphtherie-Polyneuropathie des Menschen gedeutet werden, die damit eher der experimentellen Form des Kaninchens als der des Meerschweinchens entspricht.
    Notes: Summary Mucle biopsies from the lower extremities of four patients with severe tetraplegic form of diphtheritic polyneuropathy were examined by modern techniques including histochemistry, electron microscopy and morphometric procedures. Until now comparable studies have not been published. The biopsies were removed during the acute stage of the polyneuropathy. We found scattered small angulated muscle fibers beside a more generalized slight atrophy predominantly of type 2B fibers and targetoid-phenomenons or cores in type 1 fibers. Beside this neurogenic pattern there also were, corresponding with the results of electromyography, primary myogenic alterations with different degenerative phenomenons, suspicious of toxic origin as in cardiac muscle. The intramuscular vessels showed no abnormalities except some perivascular predominantly mononuclear cellular reactions with a remarkable number of cerebriform lymphoid cells, probably T-lymphocytes. No specific pathological alterations could be detected in 11 intramuscular nerves and two motor endplates. This may reflect the more proximal demyelination of human peripheral neurons by the diphtheria toxin as found in experimental diphtheria of the rabbit in contrast to the more distal type of the guinea pig.
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  • 60
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    Acta neuropathologica 54 (1981), S. 287-292 
    ISSN: 1432-0533
    Keywords: Mucopolysaccharidoses III ; Sanfilippo's syndrome ; Histochemistry ; Electron microscopy ; Lipofuscin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A histochemical and ultrastructural study was made on the brain of a 23-year-old man with Sanfilippo's syndrome. In accordance with previous reports the cortical nerve cells contained a PAS-positive lipid storage substance. This showed intense autofluorescence in UV-light and was positive with various stains for lipofuscin. The storage material appeared ultrastructurally as inclusion bodies composed of short lamellated membranes, granular material, and vacuoles. In addition, concentrically and transversely lamellated membranous cytoplasmic bodies were observed in the nerve cells. It is concluded that the PAS-positive lipid storage material in the neurons was composed partly of lipofuscin in addition to other lipids presumably glycosphingolipids.
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  • 61
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    Acta neuropathologica 55 (1981), S. 81-87 
    ISSN: 1432-0533
    Keywords: Canine CNS ; Myelination ; Hypomyelinogenesis ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The ultrastructure of myelin deficiency in Chow Chow dogs was studied in the spinal cord of a 15-month-old and a 3-year-old animal. It was found that myelination progresses with age in these dogs but is still deficient at the age of 3 years. The findings included axons with thin or uncompacted myelin sheaths, separated from each other by massive astrocytosis, and bizarre myelin formations. Normal numbers of morphologically normal oligodendrocytes were present in the myelin-deficient areas. The disease in these Chow Chow dogs consists of a strongly retarded myelination which is possibly due to a dysfunction or delay in glial maturation.
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  • 62
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    Archives of dermatological research 271 (1981), S. 171-182 
    ISSN: 1432-069X
    Keywords: Hypomelanotic macule ; Tuberous sclerosis ; Electron microscopy ; Hypomelanotische Macula ; tuberöse Hinrsklerose ; Elektronenmikroskopie
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Hypomelanotische Maculae der Haut bei der tuberösen Hirnsklerose (TS) werden verursacht durch einen komplizierten Prozeß, in den die Synthese und Reifung von Melanosomen verwickelt sind. Weil die Charakterisierung von Hautbiopsien aus hypomelanotischen Maculae bei TS-Patienten zur Zeit nicht ausreichend ist, haben wir eine quantitative Methode entwickelt, durch die die Reifung der Melanosomen in den Melanocyten erforscht wird. Diese Methode wurde anhand von Biopsien aus hypomelanotischer und der angrenzenden Haut von sechs Patienten mit erwiesener TS geprüft und mit bekannten Methoden verglichen. Bei allen sechs Patienten wurde in der hypomelanotischen Macula eine statistisch signifikant niedrigere Zahl von pigmentierten Melanosomen pro melanocytärem Perikaryon und dendritischem Zellprozeß festgestellt als in der angrenzenden Haut. Die relative Anzahl von Stadium III- und IV-Melanosomen hatte in der hypomelanotischen Macula abgenommen, die von Stadium II-Melanosomen zugenommen (auch statistisch signifikant). Durch Verwendung unserer Methode kann die Hypomelanose der TS zuverlässig charakterisiert werden, was möglicherweise aus diagnostischer Sicht wichtig ist. Die Resultate der Melanosomengrößenmessung oder die des DOPA-Verfahrens dagegen waren statistisch nicht signifikant.
    Notes: Summary Hypomelanotic macules of the skin in tuberous sclerosis (TS) are caused by a complex process, involving the synthesis and maturation of melanosomes. A quantitative method was developed to investigate the maturation of the melanosomes at the level of the melanocytes. The method was tested on biopsies of hypomelanotic and adjacent normomelanotic skin from six patients with definite TS, and compared with other methods. In all patients, a statistically significant lower number of pigmented melanosomes was found per cross-sectioned melanocytic perikaryon and dendritic cell process in the hypomelanotic as compared to the normomelanotic skin. The relative numbers of stage III and IV melanosomes were decreased, and of stage II melanosomes increased in the hypomelanotic macule (also statistically significant). This indicates that it is possible to characterize the hypomelanosis in TS reliably, which may have diagnostic importance. In our hands, assessment of the size of the melanosomes did not show a statistically significant difference between hypo- and normomelanotic skin; the difference found with the DOPA technique was more evident, although not statistically significant.
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    Calcified tissue international 33 (1981), S. 143-151 
    ISSN: 1432-0827
    Keywords: Calcium transport ; Cytochalasin B ; Dihydrocytochalasin B ; Colchicine ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary In vivo calcium absorption was studied in normal and rachitic chicks. Cytochalasin B (CB) at a concentration of 25 µg/ml added to the medium inside the duodenal lumen inhibited calcium absorption (20 min) from 82.5±1.9% of calcium absorbed in the controls to 59.2±3% in normal and from 70.0±2.3% to 47.0±2.1% in rachitic chicks. In vitro studies by everted ileal sacs of young rabbits also showed an inhibition of active transport of calcium due to CB. Whereas in the controls the ratio of45Ca concentrations in serosal and mucosal media (60 min) was 7.2±0.32, the ratios were 5.24±0.52; 4.40±0.36; 3.40±0.42; 5.77±0.52; 1.38±0.08; and 1.06±0.02 in the presence of CB at concentrations of 5, 10 and 25 µg/ml; colchicine 10−4M, Na citrate 0.02M, and heat-devitalized conditions, respectively.45Ca concentration in the mucosal scrapings was also affected. It showed an increase from controls (15,101±404 cpm/mg) and correlated with CB concentration: 17,378±489, 19,015±1000, and 20,201±362 at 5, 10, and 25 µg/ml, respectively. Dihydrocytochalasin B also inhibited active calcium transport and caused an increase in45Ca concentration in the mucosal scrapings. Correlated electron microscopic studies showed certain changes in the brush border, especially in some actin microfilaments in the terminal web region. It seems that these morphological alterations may be related to transcytoplasmic movement of calcium.
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  • 64
    ISSN: 1432-0827
    Keywords: Alcohol ; Electron microscopy ; Growth plate
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary We have previously demonstrated that ethanol has a direct toxic effect on the rat skeleton characterized by decreased trabecular bone volume. In the present study, we examined the ultrastructure of the distal radial epiphyseal growth plates in these same animals. Eight weeks of ethanol administration to 12 male rats results in serum alcohol levels of 140 mg/dl but did not alter the width or light microscopic appearance of the radial growth plate. Quantitative electron microscopy failed to demonstrate morphologic evidence of toxicity in the skeletal cells. We conclude that although ethanol appears to have a direct effect on rat bone characterized by enhanced resorption, toxicity is not attended by ultrastructural changes in the skeletal cells.
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  • 65
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    Calcified tissue international 33 (1981), S. 529-540 
    ISSN: 1432-0827
    Keywords: Bone cells ; Electron microscopy ; PTH ; PGE1
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Four different cell populations—designated PF, OB, OC, and PC—were isolated from calvaria of 18-day-old chick embryos for analysis of the effects of hormones on bone tissue. The cell populations were studied with histological and biochemical methods. Apart from the well-known cell types present in calvaria, a new cell type was found in the noncalcified organic matrix between the osteoblastic layer and the calcified matrix. These cells were provisionally called osteocytic osteoblasts. They represent the “transition state” between osteoblasts and osteocytes. On the basis of histological studies with light microscopy (LM), transmission electron microscopy (TEM) and scanning electron microscopy (SEM), the PF population was considered to originate primarily from the periosteal fibroblasts, the OB population from the osteoblasts and osteocytic osteoblasts. The population of cells still present in calvaria after removal of periosteal fibroblasts and osteoblasts was called the OC population. This cell population was very much enriched with osteocytes. The fourth isolated population (PC) was a mixed population of fibroblasts, osteoblasts, and preosteoblasts. On exposure to parathyroid hormone (PTH), all four cell populations showed increased lactate production, but only the OB and OC populations displayed increased cAMP production. Prostaglandin E1 (PGE1) stimulated cAMP production in both OB and PF cells. From the results of this study it was concluded that PTH receptors are present on all of the cell types studied, but that occupancy of the receptor induces adenylate cyclase stimulation only in osteocytes and fully differentiated osteoblasts.
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  • 66
    ISSN: 1432-0827
    Keywords: Connective Tissue ; Vitamin D deficiency ; Hydroxyproline excretion ; Glycosaminoglycan excretion ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary The urinary excretion of two connective tissue metabolites was studied in both control and vitamin D deficient rats. Hydroxyproline (HyPRO) excretion was determined after 2, 13 and 22 months (experiment I). It decreased with aging in animals receiving the control diet. On the contrary, this excretion increased as a function of age in vitamin D deficient animals. At the age of 22 months, HyPRO excretion was respectively 31 and 1708 µg a day in control and deficient animals. HyPRO and glycosaminoglycans (GAG) excretion was measured on a group of both control and vitamin D deficient rats at the age of 21 months (experiment II). These results confirm the high excretion of HyPRO in deficient animals. On the contrary, the GAG excretion was higher in control animals than in deficient ones, the mean excretion being respectively 412 and 234 µg a day.
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  • 67
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    Calcified tissue international 33 (1981), S. 223-231 
    ISSN: 1432-0827
    Keywords: Protein deficiency ; Bone formation ; Skeletal development ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Protein deficiency was produced by freely feeding young rats a 1% lactalbumin diet for 12 weeks in order to study the effects of protein-calorie malnutrition on skeletal development. During the experiment the food and caloric intake and weight of the experimental animals decreased, while those parameters of the control animals progressively increased. However, when gross caloric intake was expressed as a function of the metabolic size of the animal, the caloric consumption was similar for both groups of animals. The protein-deficient animals exhibited micro-radiographic and histological features of an abnormal pattern of endochondral bone formation. Appositional bone growth, as determined by the daily appositional rate and the percentage of endosteal surfaces undergoing active bone formation, was significantly decreased in these animals, as was the percentage of periosteal surfaces exhibiting resorption. Both chemical analyses of the whole bone and electron probe microanalysis in the specific area of actively calcifying bone revealed no significant differences between the mineral content of control and protein-deficient animals. This study distinguishes the effects of protein deficiency from that of combined protein-calorie deprivation and demonstrates that the abnormal skeletal development observed was the result of a decrease in the quantity of bone formed rather than an altered mineral content.
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  • 68
    ISSN: 1432-0827
    Keywords: Rat ; Incisor ; Amelogenesis ; Acid phosphatase ; Ferritin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary Acid phosphatase was localized in rat incisor ameloblasts without prior decalcification. Whenβ-glycerophosphate was used as the substrate, an intense reaction was observed in the supranuclear region of the secretory ameloblasts. But the reaction was dramatically reduced at the transitional stage and was very weak in the maturation ameloblasts. Whenp-nitrophenylphosphate was the substrate, the reaction product was consistently seen in the Golgi cisternae and the vesicular components of the ameloblasts at all stages of enamel development. These observations suggest that there are two acid phosphatases in ameloblasts. One is in the secretory ameloblasts and the other in the transition and maturation ameloblasts. X-ray micro-analyses for Fe and Pb showed that Fe and acid phosphatase were in the ferritin-containing vesicles at the later stage of enamel maturation. This evidence suggests that ferritin is digested in these vesicles for the release of the Fe pigment to the enamel. An increase in the number of intercellular bridges between ameloblasts was correlated with the dramatic decrease in height of ameloblasts at the pigment release stage. The ameloblast membranes were acid phosphatase positive at the intercellular bridges whenp-nitrophenylphosphate was the substrate. This activity may be involved in the reduction in the surface area of the ameloblast membranes.
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  • 69
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    Calcified tissue international 33 (1981), S. 119-124 
    ISSN: 1432-0827
    Keywords: Avian eggshell ; Microstructure ; Electron microscopy ; Electron diffraction ; Calcite growth
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Summary The eggshell of the domestic fowl has been studied by transmission electron microscopy and diffraction. Thin sections of shell were prepared by chemical and ion-beam thinning techniques. Each calcite column of the palisade layer consisted of crystallites of diameter 20 to 30 µm with some tendency for crystallite alignment within a single column. Evidence indicates that there was no significant preferred orientation in the palisade layer as a whole. Only in the surface layer was any preferred orientation detected, and here {1014} planes tended to lie parallel to the surface. The results are compared with previously published data, and calcite nucleation and growth are discussed.
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  • 70
    ISSN: 1432-1246
    Keywords: Diesel exhaust emission ; Liver ; Electron microscopy ; Freeze-fracture
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The livers of Syrian golden hamsters were examined with the light and electron microscope using the techniques of thin sectioning and freeze-fracture following 5 months of exposure to various concentrations of diluted diesel exhaust gases. The light microscopical examination showed enlarged sinusoides with activated Kupffer's cells and slight changes in the cell nuclei. In the electron microscopical examination the most striking changes were seen in the mitochondria, which frequently showed a loss in cristae. In addition, the mitochondria exhibited pleomorphic character. The microbodies were of the same size as mitochondria. An increase in the number of lysosomes was observed especially in the tissue surrounding the narrow bile canaliculi. The various alterations corresponding to the different concentrations of exhaust gases could be seen especially well in the sinusoides, the mitochondria and the microbodies. In general the hepatocytes appeared to be moderately enlarged. The zonulae occludentes showed a more irregular outline and large maculae tight junctions were found on the lateral region of the plasmalemma of hepatocytes. The gap junctions exhibited a wide range of structural diversity. The intramembranous particles on the P fracture face of the plasmalemma of hepatocytes are aggregated.
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  • 71
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    Experimental brain research 41 (1981), S. 135-145 
    ISSN: 1432-1106
    Keywords: Supraoptic nucleus ; Rat ; Antidromic ; Phasic ; Recurrent inhibition
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Antidromically identified neurones were recorded from the supraoptic neucleus of urethane-anaesthetised rats. In test periods of about 10 min, each recorded action potential was followed 1 ms later by a shock to the neural stalk. In phasically firing cells, this stimulation consistently modified the observed firing pattern: burst length was shortened but intraburst activity was unchanged. The stimulation invaded most supraoptic neurones antidromically, but antidromic spikes evoked in the recorded neurone were extinguished by collision. Thus, the observed changes in firing pattern were probably the consequence of interaction between the recorded unit and other neurones projecting to the neural stalk — most probably other supraoptic neurones. The behaviour of continuously firing supraoptic neurones was studied following single shocks and following trains of shocks. The results suggest that the widely reported evidence for recurrent inhibition in the rat supraoptic nucleus has been misinterpreted, and that inhibition cannot be demonstrated in most supraoptic neurones following single shocks to the neural stalk. However, the experiments using trains of shocks produced evidence consistent with a complex interaction between magnocellular neurosecretory cells involving both excitation and inhibition.
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  • 72
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    Experimental brain research 41 (1981), S. 184-187 
    ISSN: 1432-1106
    Keywords: Visual cortex ; Layer I ; Afferent connections ; HRP ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The afferent connections to layer I of the visual cortex, area 17, of the albino rat were studied using the retrograde transport of horseradish peroxidase (HRP). In all animals examined, the majority of labeled cells were observed in the dorsal lateral geniculate nucleus and in the lateral posterior nucleus. In addition, in one-half of the animals examined labeled cells were also present in the posterior complex of the thalamus and in the ventromedial nucleus. Finally, in three cases a few HRP-positive neurons were observed in the locus coeruleus and in the dorsal raphe nucleus.
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  • 73
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    Experimental brain research 41 (1981), S. 316-328 
    ISSN: 1432-1106
    Keywords: Orienting behavior ; Superior colliculus ; Visual cortex ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The effect of visual cortical and subcortical lesions on orienting behavior was assessed by examining the rats' ability to interrupt an ongoing response and perform appropriate head and postural adjustments to repeatedly presented auditory or apparently moving visual stimuli. Large lesions of the entire superior colliculus (SC) or the deep layers of the SC did not result in visual agnosia or the inability to perform the motor responses involved in orienting. Rather, the orienting response simply was not emitted to visual stimuli that the intact rat treated as less salient, but was to those it treated as more salient. Lesions of either the superficial layers of the SC or visual cortex also did not completely prevent orienting to very salient, apparently moving visual stimuli, but did produce changes in the number of responses made to such stimuli and in the occurrence of other components of orienting behavior. It was suggested that the SC and visual cortex play a modulatory role in orienting behavior and that stimulus characteristics must be considered in the development of neuronal models of orienting behavior.
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  • 74
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    Experimental brain research 41 (1981), S. 346-357 
    ISSN: 1432-1106
    Keywords: Rat ; Tryptophan deprivation ; Sleep circadian rhythm ; Serotonin metabolism
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary 1. A long-term (up to 16 weeks) tryp-tophan (TRP)-free diet was administered to chronically implanted adult rats in order to study the effects of a sustained reduction of endogenous brain serotonin (5-HT) levels on the sleep-waking cycle. Twentyfour hours polygraphic recordings were made either periodically on an EEG apparatus, or uninterruptedly over 50 days by a frequency analyser. Quantitative changes in wakefulness (W), slow wave sleep (SWS) and paradoxical sleep (PS), as well as the number and duration of these episodes, were studied over 24 h, with a dark period (DP) and a light period (LP). Biochemical changes in 5-HT metabolism were measured in both plasma and brain. 2. Under control conditions, the percentage of W was twice as great in DP as in LP, while the quantities of SWS and PS were twice as high in LP as in DP. Surprisingly, in spite of a decrease of about 50% in brain 5-HT under TRP-deprived conditions, no dramatic changes were observed in the qualitative or quantitative aspects of W, SWS or PS. The only electrocorticographic (ECoG) change was a disappearance of sleep spindles, which became total after 14 weeks. During the first month, there was a 7% increase in W accompanied by a 6% decrease in SWS and a 5–9% reduction in PS. Later, W and SWS returned to their control values, while the PS deficit persisted throughout the TRP-deprivation period. Despite the absence of severe quantitative disturbances over 24 h, an internal reorganization of the sleep cycle took place. This new balance, established after 2 months, was characterized by a tendency toward an equal distribution of the stages in DP and LP, resulting in the disappearance of the sleep circadian rhythm. 3. Our results are compared with those of other authors who lowered the endogenous 5-HT levels by various means, including ‘acute’ or partial TRP-deprivation. The present findings suggest that adaptive cerebral mechanisms are able to compensate for the disturbances in 5-HT metabolism, in structures responsible for W and SWS. They indicate that the neurohumoral processes underlying sleep circadian rhythm in the rat are serotoninergic and/or noradrenergic.
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  • 75
    ISSN: 1432-1106
    Keywords: Cat-spinocervical tract cells ; Intracellular staining ; Electron microscopy ; Synaptic vesicles
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Synaptic vesicles in initial collateral terminals of two feline Spinocervical tract cells have been investigated after intracellular staining with horseradish peroxidase. A total of 5325 vesicles in 52 axodendritic and 26 axo-somatic terminals were analysed after aldehyde-osmium fixation. The greatest length and longest perpendicular width of each vesicle were measured, and the ratio and geometric mean of the diameters (gm-diameters) were calculated. The vesicles were divided into classes with round, elliptical and flat organelles. The variations in vesicle length, gm-diameter, and diameter ratio were statistically analysed by means of one- and two-way analyses of variance and t-tests. The diameter ratio, the length of round vesicles, and the gm-diameters of round and elliptical vesicles differed significantly between the cells. The length and gm-diameter of the elliptical vesicles differed significantly between the groups of axo-dendritic and axo-somatic terminals of each cell. Round vesicles were significantly longer in the axosomatic than in the axo-dendritic terminals of each cell, and the gm-diameter showed this relation for both round and elliptical vesicles. It is assumed that a one-size vesicle could not account for all the measured profiles. The variability of synaptic vesicles within and between the functionally similar cells emphasize the difficulties in using the morphology of synaptic vesicles for a discrimination of axon terminals of different origin.
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  • 76
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    Experimental brain research 42 (1981), S. 467-474 
    ISSN: 1432-1106
    Keywords: Interocular transfer ; Rat ; Commissures
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The effect of sectioning the corpus callosum on interocular transfer of a brightness and a horizontal/vertical discrimination was examined in hooded rats. Lesions of the posterior portion of the callosum usually led to moderate transfer deficits, but considerable individual variation was found. Lesions involving only the anterior part of the callosum had little effect on transfer. This suggests a functional localisation in the corpus callosum of the rat similar to that seen in higher mammals. Section of the posterior and tectal commissures and the thalamic massa intermedia in addition to the callosum had no greater effect on transfer than callosal section alone. It is therefore unlikely that these structures play a crucial role in interocular transfer in the rat.
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  • 77
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    Experimental brain research 42 (1981), S. 362-370 
    ISSN: 1432-1106
    Keywords: Carotid baroreceptor ; Pain afferents ; Pontine neurone ; Rat ; Supraoptic nucleus neurone
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Effects of pressure stimulation of the isolated carotid sinus, of occlusion of the common carotid artery and of tail pinching on the discharge activity of dorsal pontine area neurones and antidromically identified supraoptic neurosecretory neurones were studied in male rats anaesthetized with urethane. Electrical stimulation of the supraoptic nucleus (SON) produced antidromically conducted action potentials in a small number (24/384) of the units recorded in the dorsal pontine area. Pressure pulse stimulation of the isolated carotid sinus inhibited and carotid occlusion facilitated discharge activity in some of the tested dorsal pontine area neurones. In these responsive pontine neurones a transient excitation of grouped discharges was occasionally observed to concur with a small, spontaneous depression of the arterial blood pressure. Tail pinching excited some of these pontine neurones. Histological examination revealed that these responsive neurones were located in the dorsal pontine area close, but ventral and lateral, to the locus coeruleus. Electrical stimulation of the dorsal pons evoked a synaptically mediated excitation in 20 and inhibition in the other seven of the 52 SON units which were identified antidromically after stimulation of the pituitary stalk. Pressure stimulation of the isolated carotid sinus evoked an inhibition of discharge activity in some of the SON units which were excited by dorsal pontine area stimulation. All of the six tested units which showed inhibition after dorsal pontine area stimulation were unresponsive to pressure stimulation. Based on these data, it was concluded that at least some of the neurones which mediate carotid baroreceptor inputs to SON neurosecretory neurones are located in the dorsal pontine area close, but ventral and lateral, to the locus coeruleus and that these dorsal pontine area neurones also mediate converging synaptic inputs originating from somatic pain receptors.
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  • 78
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    Experimental brain research 44 (1981), S. 97-100 
    ISSN: 1432-1106
    Keywords: Nucleo-cortical fibers ; Cerebellum ; Mossy terminals ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Intact mossy terminals observed in the granular layer of rat cerebella, two weeks after complete transection of all cerebellar peduncles, were identified as the endings of the intracerebellar nucleo-cortical afferents. A quantitative study of synaptic vesicle size spectra revealed clear differences between nucleo-cortical and true extracerebellar mossy afferents. These differences suggest that the nucleo-cortical afferents are recurrent collaterals of the projective nucleofugal fibers.
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  • 79
    ISSN: 1432-2013
    Keywords: Hepatic blood flow ; Hepatic clearance ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Two new methods are described to measure hepatic blood flow in the anaesthetized rat. These methods are based on the fractional clearance and extraction of indocyanine green, which is removed by hepatocytes, and of colloidal radiogold, which is removed by Kupffer cells. Hepatic blood flow was found to be 2.11±0.35 ml·min−1·g liver−1 (mean ±SD) and 2.01±0.31 ml·min−1·g liver−1, respectively, with these two substances (P〉0.80).
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  • 80
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    Pflügers Archiv 391 (1981), S. 200-207 
    ISSN: 1432-2013
    Keywords: Chronic stimulation ; Fast muscle ; Slow muscle ; Contractile properties ; Muscle fatigue ; Histochemistry ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Leg muscles of adult rats were stimulated chronically at a low-frequency, and the histochemical reactions of various enzymes (succinic dehydrogenase, mitochondrial α-glycerophosphate dehydrogenase, phosphorylase, alkali-ATPase and acid-ATPase), capillary density, resistance to fatigue, and contractile properties were studied. Following stimulation, the histochemical properties of muscle fibres in the fast extensor digitorum longus (EDL) and tibialis anterior (TA) muscles became similar to those of the majority of fibres in the slow soleus muscle. In the soleus muscle, the histochemical properties of the few fast type fibres became similar to the majority of ‘slow’ fibres so that its fibre composition was homogeneously ‘slow’. The stimulated fast muscles also had higher capillary density and were more resistant to fatigue than normal. Despite the prolonged stimulation, the twitch duration of the fast muscles was little changed. This result differs from the findings obtained previously for the rabbit and cat, which show that slowing of contraction can be achieved by low-frequency activity of similar duration. Thus it may be that there is a species difference regarding the readiness with which the transformation of fast to slow muscles can be brought about.
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  • 81
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    Pflügers Archiv 392 (1981), S. 34-39 
    ISSN: 1432-2013
    Keywords: Erythropoietin ; Erythropoiesis ; Kidney ; Hypoxia ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Controversial hypotheses exist as to whether hypoxic kidneys produce biologically active erythropoietin (Ep) or an inactive erythropoietic factor that generates Ep from plasma protein in the blood. To clarify the role of the kidney in Ep production we attempted to extract Ep from kidneys of normal and of hypoxia exposed (6 h at 0.42 atm) Sprague-Dawley rats. Ep was measured in the microsomal fraction of kidney homogenates, using the exhypoxic polycythemic mouse assay for Ep. The Ep content was also determined in kidneys that were flushed free of blood with isotonic phosphate-buffer prior to extirpation. We found 0.04 U Ep/g in blood-depleted kidneys of normal rats. Upon exposure of the animals to hypoxia the Ep level increased to 0.92 U/g kidney. Ep levels were significantly higher in the kidney cortex than in the medulla. The erythropoietic activity in renal extracts was not enhanced after incubation of samples with homologous serum. Ep extracted from hypoxic kidneys behaved identically with plasma-Ep in the following biochemical tests: heat stability, affinity chromatography with wheat germ lectin, ion exchange chromatography, molecular sieve chromatography and neuraminidase inactivation. These studies support the hypothesis that kidney cortex cells are capable of producing biologically active Ep.
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  • 82
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    European biophysics journal 7 (1981), S. 209-212 
    ISSN: 1432-1017
    Keywords: Photosynthetic bacteria ; Electron microscopy ; Planar lattices
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Physics
    Notes: Abstract The thylakoids of Rhodopseudomonas viridis have been studied by freeze-fracturing whole cells. Depending on growth conditions and treatment before freezing, three different types of particle arrangements in the photosynthetic membrane are reported: a random arrangement, an isometric (quadratic) lattice arrangement with a lattice constant of 12.5 ± 0.8 nm, and a hexagonal lattice arrangement with a lattice constant of 12.5 ± 0.8 nm.
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  • 83
    ISSN: 1432-0738
    Keywords: Methylmercury ; Protein synthesis ; Liver ; Adrenal ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract (1) A single injection of methylmercury chloride in the rat (10–50 mg/kg) increased both in vivo and in vitro rates of 14C-leucine incorporation into the protein of the post-mitochondrial supernatant fraction of the liver. In contrast, no stimulation of protein synthesis was observed in the brain of the methylmercury-treated rats. (2) Methylmercury administration also stimulated RNA polymerase activities in isolated hepatic nuclei, stimulation of Mg-dependent activity being higher than that of Mn-dependent activity. (3) In experiments with adrenalectomized rats, it was found that the stimulatory effect of methylmercury on protein and RNA synthesis in the liver was mediated partly through the adrenal gland. (4) Analysis of serum by starch-block electrophoresis revealed that synthesis of all serum proteins, including albumin and α-γ globulin fractions, was stimulated by methylmercury treatment. (5) These results suggest that the observed effects of methylmercury on the liver depend on mechanisms other than enhancement of the synthesis of acute-phase proteins.
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  • 84
    ISSN: 1432-0738
    Keywords: CO exposure ; Cardiovascular system ; Rat ; Histology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Regarding the potential impact of traffic-born air pollutants on public health, in recent years attention has increasingly been focused on the possible effects on the cardiovascular system. In order to investigate this problem further, the influence of long-term exhaust gas exposure on rats has been studied. One hundred Wistar rats of either sex were exposed 5 × 8 h/week up to 28 months to an atmosphere polluted by the emissions of an idling Otto engine, CO concentrations held constant at 90 ppm. A second group (50 rats) was exposed to 250 ppm for 6 months. Blood parameters and body weight were controlled. Specimens of CNS, heart, vessels, kidney etc. were investigated light microscopically. Focal necroses of the myocardium with inflammatory reactions as well as interstitial fibrosis were found in the heart muscle of the 90 ppm group. In the 250 ppm group endothelial proliferations, edema of the intima and deposits of proteoglycanes in the media were observed. We conclude that subtoxic concentrations of CO which only lead to slight morphologic changes may aggravate preexisting lesions caused by high risk conditions, e.g., hypertension or hypercholesteremia.
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    Archives of toxicology 48 (1981), S. 29-39 
    ISSN: 1432-0738
    Keywords: Copper ; Zinc ; Mercury ; Diethyldithiocarbamate ; Carbon disulphide ; Thiocarbamates ; Chelating agent ; Mouse ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Oral treatment of rats with tetramethylthiuram disulphide (TMTDS), 0.1% mixed in the food (corresponding to 20–30 μmol daily) for one week, increased the brain levels of endogenous copper and zinc to 120% and 170%, respectively, of the control levels. Mice injected with HgCl2 (2.5 μmol/kg) were used to study further the effect of DDC (diethyldithiocarbamate), disulfiram, TMTDS or CS2 on heavy metal distribution. The brain levels of Hg were significantly increased in mice given DDC or TMTDS. Disulfiram and CS2 increased the brain levels marginally. Pregnant rats exposed to HgCl2 (0.5 μmol/kg) were also included in the studies. Treatment with DDC (0.5 mmol/kg) immediately after the mercury injection, increased the maternal brain concentration of mercury considerably, as measured after 24 and 78 h. The kidney levels were also increased. In the foetuses, the brain and liver levels were transiently increased after treatment with diethyldithiocarbamate. The observations support the hypothesis that the neurotoxicity of diethyldithiocarbamate and other thiocarbamates may be related to changes in heavy metal metabolism.
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    Archives of toxicology 47 (1981), S. 191-196 
    ISSN: 1432-0738
    Keywords: Manganese ; l-Dopa ; Dopamine ; Corpus striatum ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The turnover rate of striatal dopamine (DA) and the effect of l-dopa treatment was investigated in rats after the daily oral administration of MnCl2 · 4H2O for a period of 30 days. The turnover rate of striatal DA, as determined by the administration of α-methyl-p-tyrosine, increased significantly in manganese-exposed rats. l-Dopa administration resulted in a significant elevation in the levels of DA and its metabolite, homovanillic acid, in manganese-exposed rats, but these neurochemical changes could not be correlated with the concentration of manganese in the striatum. We therefore advise that l-dopa therapy should not be tried in early manganese intoxication, as it may aggravate manic symptoms due to marked increase in brain DA.
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  • 87
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    Archives of toxicology 47 (1981), S. 233-239 
    ISSN: 1432-0738
    Keywords: Hexachlorobenzene ; Paraffin ; Squalane ; Pendular perfusion ; Intestinal excretion ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract 1. The intestinal excretion of hexachlorobenzene (HCB) was studied in rats using the method of pendular perfusion. One and four weeks after i.p. application of 100 mg HCB/kg body weight segments of jejunum, ileum and colon were perfused with light liquid paraffin or squalane for 5 h. 2. The highest amount of HCB was excreted into jejunum, followed by ileum and colon. After 5 h HCB concentration in jejunal perfusion medium equals that in plasma. 3. Serosal tissue of intestinal segments contained higher HCB concentrations as compared to mucosa. 4. Paraffin treatment decreased the HCB content in both serosal and mucosal tissue of jejunum and ileum but not of colon.
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  • 88
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    Archives of toxicology 48 (1981), S. 1-9 
    ISSN: 1432-0738
    Keywords: Placental transfer ; Organogenesis ; Rat ; Embryotoxicity ; Toxicokinetics ; Thiamphenicol
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Measurement of thiamphenicol transfer to the rat embryo during organogenesis was performed as one step of the determination of possible drug embryotoxicity in man. Extrapolation of data on animal embryotoxicity to man will only become possible when data on the toxicokinetic properties of the substance under investigation are available for both animal and man. 1) Thiamphenicol, given between day 11.5 and 14 of rat gestation, rapidly reached the embryo; 4–6 h after single i.v. or s.c. injection, embryonic and maternal thiamphenicol levels became equal and decreased from that time on at the same rate. 2) No evidence was found for development of a placental barrier with increasing placental function. The same dose applied at different developmental stages yielded the same embryonic drug concentrations. 3) Elimination via kidney (unchanged) or bile (glucuronide), may become rate-limiting for thiamphenicol excretion. Doses exceeding 50 mg/kg (i.v.) or approx. 100 mg/kg (s.c.) yielded thiamphenicol levels higher than those expected from linear dose-concentration relationships. 4) Drug concentrations (〉 3–5 μg/g wet weight) obtained with dosing regimens (〉 100 mg/kg/day) used for experimental induction of embryolethality in rats are equal to those necessary for inhibition of mitochondrial protein synthesis in vitro and to those necessary for treatment of bacterial infections in man.
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  • 89
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    Archives of toxicology 48 (1981), S. 41-50 
    ISSN: 1432-0738
    Keywords: Cyanide ; Zinc ; Copper ; Manganese ; Atomic absorption spectrophotometry ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Single doses of sodium cyanide (60 μmol/kg body weight s.c.) were administered to male Sprague-Dawley rats. The effect of this poison on the content of the trace elements zinc, copper and manganese was investigated in various organs after 30 min, 2 h, 24 h, 48 h and 1 week. The zinc content in the liver was elevated 24 h after this sublethal cyanide dose (by approximately 20%). In contrast, the copper content in the kidneys was lowered (by approximately 15%) at the same time. Almost similar changes were observed in the same organs after daily administration of the poison for 5 days. For comparison, another group of rats was allowed to respire for 30 min the air that contained only 10% oxygen. The above changes in the trace element concentrations were not observed under these conditions. After sublethal cyanide poisoning there seemed be slight but specific alterations in the trace element concentrations in the liver and kidneys of rats. On the other hand, there were no alterations in serum, heart, lung, brain, muscle, bone or testes. Up to now there is no clearcut explanation for the development and the possible biochemical importance of these results.
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  • 90
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    Archives of toxicology 48 (1981), S. 271-279 
    ISSN: 1432-0738
    Keywords: Thallium (I) ions ; Colonic secretion ; Voltage clamp ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract 1. Movement of thallium (I) ions across the mucosal epithelium of descending rat colon, stripped of the muscularis externa in vitro was determined under voltage clamp conditions. 2. The unidirectional fluxes of thallium (I) ions from mucosal to serosal side (M → S) and in the opposite direction (S → M) were measured at 0 mV. A net flux of thallium (I) ions was observed from serosal to mucosal side (0.216 nmoles · cm−2 · h−1) in other words, the mucosal epithelium is apparently asymmetric for the movement of thallium (I) ions. 3. The investigations were carried out on the range of −30 mV up to +30 mV from mucosal to serosal side. Thallium (I) ions move from mucosal to serosal side (M → S) by diffusion only (Pi = 0.119 cm · h−1), whereas into the opposite direction (S → M) thallium (I) ions in addition to a voltage-dependent component are transported against an electrical gradient.
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  • 91
    ISSN: 1432-0738
    Keywords: Methylmercury ; Neurotoxicity ; Sex difference ; Rat ; Cerebellar damage ; Coordination disorders
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Male and female rats were dosed daily by gastric gavage four or five times with 8.0 mg/kg Hg as methylmercury. Treatment lowered the body weight in relation to the body weight of untreated rats to the same extent in male and female rats but when body weight was related to the initial body weight, the effect of methylmercury was more pronounced in females than in males. The importance of differences in growth or loss of body weight is that in spite of the similar whole body clearance mercury concentrations were higher in females than in males. After identical doses the brains of females always contained more mercury than those of males and in both sexes the brain concentration of mercury showed a disproportionate elevation when the number of doses was increased from four to five. However, weight change alone does not explain the sex related difference in the brain concentration of mercury as this was evident even 72 h after a single dose. In agreement with the brain concentration of mercury, female rats developed more intensive co-ordination disorders and after five doses they had more extensive damage in the granular layer of the cerebellum than males.
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  • 92
    ISSN: 1432-0738
    Keywords: Polychlorinated paraffins and terphenyls ; Liver ; Cytochrome P-450 ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The polychlorinated terphenyl Aroclor 5460 and the polychlorinated paraffins Witaclor 171 P and Witaclor 149 increased to different degrees the total microsomal concentration of cytochrome P-450 in the rat liver after intraperitoneal injection of 0.3, 1.0, and 1.0 g · kg−1 body weight, respectively, each day for four days. The multiple forms of cytochrome P-450 were affected differently with an induction of RLvMc P-45050 and RLvMc P-45054 by all chemicals, and an additional induction of RLvMc P-45055 by the polychlorinated terphenyl. The rat liver weights were extensively increased after treatment with the polychlorinated paraffins. Alterations were found in the in vitro metabolism of biphenyl, benzo(a)pyrene and the steroid hormones, 4-androstene-3,17-dione and 5α-androstane-3α,17β-diol, after exposure to all chemicals. Changes in the in vitro formation of benzo(a)pyrene metabolites were found to correlate with changes in the multiple forms of cytochrome P-450. The present study demonstrate that only limited information can be obtained from alterations in the total concentration of cytochrome P-450 and show the importance of studying changes in the multiple forms and the metabolism of different substrates. Our results further indicate that exposure to any of the investigated polychlorinated chemicals may alter the biological effects of other environmental contaminants, drugs and endogenous substances which are metabolized by the cytochrome P-450 enzyme system.
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  • 93
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    Archives of toxicology 49 (1981), S. 1-13 
    ISSN: 1432-0738
    Keywords: Chlorinated paraffins ; Liver ; Rat ; Metabolism ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Short term effects of chlorinated paraffins with different length of the carbon chain and different degree of chlorination were investigated with respect to rat liver cytochrome P-450 mediated metabolism and liver cell morphology. When paraffins were administered by i.p. injection liver weights increased inversely with the length of the carbon chain. The short carbon chain paraffins with a high degree of chlorination increased the concentration of liver microsomal cytochrome P-450, inhibited the metabolism of 7-ethoxyresorufin but increased the metabolism of benzo(a)pyrene, especially the formation of the 4,5-diol metabolite. Short carbon chain paraffins gave rise to a proliferation of the smooth ER, increased the number of cytoplasmic fat droplets as well as the number and size of mitochondria and peroxisomes and finally induced the occurrence of autophagosomes and lysosomes. The fat droplets were preferentially degraded in lysosomes. In all respects the long carbon chain paraffins were less biologically active.
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  • 94
    ISSN: 1432-0738
    Keywords: Behavior ; Neurochemicals ; Manganese ; Lead ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Groups of rats were exposed simultaneously to manganese chloride (3 mg Mn2+/ml water) through drinking water and lead acetate intraperitoneally at dosages of 5.0, 8.0 and 12.0 mg Pb2+/kg daily for a period of 14 days. The magnitude of changes in the behavioral pattern, contents of biogenic amines and accumulation of lead in the brain of rats simultaneously exposed to the two metals was significantly greater than observed in rats after exposure to either of the metals alone. A definite dose-response relationship was, however, noticed only with the changes in the motoractivity, norepinephrine, 5-hydroxytryptamine levels and in the accumulation of lead in rats simultaneously exposed to manganese and lead. The lowering in the contents of norepinephrine after combined treatment was found to be related with the decrease in the motoractivity in the rats. The exact role of depression in the levels of dopamine and 5-hydroxytryptamine in inducing marked impairment in learning ability and increased aggressive behavior in rats after the combined exposure to manganese and lead could not be ascertained. The overall analysis of the data indicated that the simultaneous exposure to manganese and lead, particularly with highest dose of the latter, may produce serious derangements in the behavioral pattern and levels of biogenic amines in the brain of rats.
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  • 95
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    Archives of toxicology 47 (1981), S. 101-111 
    ISSN: 1432-0738
    Keywords: Cerebellar cortex ; Methylmercury ; Toxicity ; Rat ; Morphometry ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract A single dose of 10 mg methylmercury chloride per kg body weight was given to 30 days old rats and to adult rats (180–200 g). This resulted in brain levels of 1.4–2.2 μg Hg/g wet weight. In the young rats electron microscopic morphometry showed swelling of the granule cells. The extent of changes was more pronounced in the cerebellar hemispheres than in the vermais and flocculus. At 7 days after giving the methylmercury the granule cells appeared to have returned to normal. Methylmercury produced both light and electron microscopic changes in cerebellar neurons of adult (180–200 g) rats 3 days after dosing. 2.5–10% of the granule cells appeared dark and condensed in toluidine blue stained semithin sections of perfusion fixed and plastic embedded material. In control animals the comparable percentage never exceeded 1. By electron microscopic morphometry the dark cells proved to be shrunken to 70%, whereas the remaining light granule cells were swollen to 130% of the normal cell volume. The heterochromatin and mitochondrial volumes per cell remained constant in both dark and light cells from methylmercury treated animals. In the Purkinje cells from both young and adult rats, geometrical changes in the cisternae of the granulated endoplasmic reticulum were evident. The swelling and shrinkage of the granule cells is supposed to be due to impaired electrolyte control and the disorganized granulated endoplasmic reticulum of the Purkinje cells may be related to the deleterious effects on protein synthesis.
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  • 96
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    Journal of neurology 225 (1981), S. 67-72 
    ISSN: 1432-1459
    Keywords: Ewing sarcoma ; Epidural tumors ; Spinal cord compression ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Es wird ein Ewing-Sarcom, welches sich außerhalb des Skelettes bei einem Kind entwickelte, geschildert. Klinisch manifestierte es sich als epidurale Masse. Bei der chirurgischen Exploration zeigte sich ein brüchiges Gewebe, welches 2–3 cm lang war und nicht vom Knochen ausging. Lichtmikroskopisch und elektronenmikroskopisch ließ sich die Diagnose eines Ewing-Sarcoms stellen. Es werden morphologische Aspekte und differentialdiagnostische Überlegungen in Zusammenhang mit Tumoren des Epiduralraumes diskutiert.
    Notes: Summary The clinicopathological findings in a child with extraskeletal Ewing sarcoma are described. The patient complained of pain in the lower back and difficulty walking. An extraskeletal, epidural, friable tumor, 2–3 cm long was removed from the epidural space. It had no relationship with the bone structures. Light and electron microscopic examination of the tumor led to the diagnosis of Ewing sarcoma. The morphological aspects of this neoplasia and the problem of the differential diagnosis with other small cell tumors of the epidural space are discussed.
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  • 97
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    Journal of neurology 224 (1981), S. 171-182 
    ISSN: 1432-1459
    Keywords: Cerebral amyloidoma ; Congo red birefringence ; IgM immunofluorescence ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Eine fast walnußgroße, intra- und subcortical gelegene Masse von Congo-Rot-färbbarem Amyloid mit einigen umgebenden Lympho-Monozyten, Plasmazellen und mehrkernigen Elementen sowie doppelbrechenden plumpen Plaques und fein dispers verteilten Amyloidpräzipitaten innerhalb eines unmittelbar angrenzenden kleinen Rinden-Restgewebes wurde operativ aus dem Occipitallappen entfernt. Aufgrund der typischen grüngelblichen Doppelbrechung im Congo-Rot-Präparat, der Thioflavin-Fluoreszenz, der positiven PAS-Reaktion, Bindegewebsfaserfärbungen und des elektronenmikroskopischen Nachweises charakteristischer unverzweigter 10 nm-Fibrillen kann die Diagnose eines cerebralen Amyloidtumors (Amyloidom) gestellt werden. Bei nur schwacher Anfärbung des vielfach deutlich appositionell gewachsenen Substrates mit Anti-Bence-Jones-Proteinserum (λ-Kette) reagierten die Perikarya der mononukleären lymphoiden Zellen und der Plasmocyten im indirekten Immunfluoreszenztest besonders mit Anti-IgM (FITC-markiert). — Die Trägerin, eine 46jährige Hausfrau, hatte jahrelang recidivierende depressive Episoden und in den letzten 4 Jahren fortschreitende neurologische Symptome nach Art eines chronischen raumfordernden Prozesses ohne jegliche Anzeichen einer Systemerkrankung oder Gammopathie. Sie erholte sich nach der Operation ziemlich gut. Es wird angenommen, daß es sich — analog zum tumorförmigen Amyloid in Haut, Lunge oder anderen Organen — hier um eine isolierte cerebrale Form von Paramyloid oder nodulärer primärer Amyloidose (Amyloid L) im Sinne von Reimann et al. (1935), Cohen (1967), Azar (1973), Langer und Missmahl (1980), Glenner (1980) u. a. handelt.
    Notes: Summary An almost walnut-sized tumor was removed surgically from the left occipital lobe of a 46-year-old woman, who had suffered for 4 years from progressive visual loss with scotoma and finally from hemianopia, associated with attacks of headaches and recurrent episodes of depression each lasting for some weeks or months. Neuropathological examination, including polarization, thioflavine fluorescence, immunofluorescence staining, and electron microscopy, revealed an amyloidoma, which consisted of broad appositionally grown amyloid deposits surrounded by some plasma cells, monocytic or foreign body cell types. The massive accumulations, often associated not only with blood vessels or perivascular collagenous fibers but also lying in the cerebral tissue not unlike senile plaques in the cortical gray matter, corresponded to gradually growing masses as seen in the repeated CT scans. This unique lesion in the brain of a patient who did not show any evidence of systemic disorder, seems to confirm that the spontaneous tumor-like amyloid, which gave an immunofluorescent staining mainly with anti-IgM, is a special variant of primary amyloidosis (amyloid L) or of so-called paramyloid (Reimann et al. 1935; Cohen 1967; Azar 1973; Langer and Missmahl 1980).
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  • 98
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    Archives of microbiology 130 (1981), S. 125-128 
    ISSN: 1432-072X
    Keywords: Rhodospirillum rubrum ; Chromatophores ; Reaction centers ; Liposomes ; Electron microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract In freeze-fractures of chromatophores of Rhodospirillum rubrum the reaction centers are seen as hexagonal arranged particles of 13 nm diameter with a density of around 5,500 particles per μm2. Similar regions on the cytoplasmic membrane suggest that these parts are the prospective invagination sites. Isolated reaction centers are easily incorporated into liposomes. In freeze fractures of liposomes particles similar in shape and size, although less dense as in chromatophores are observed. In negative staining much smaller units of only 5 nm in diameter are found indicating that reaction centers occur in the membrane as tri- or tetramers. There is a strong correlation between particle density in chromatophores and titratable reaction centers remaining in these membranes after extraction of reaction centers by detergents; both values are in good agreement with the yield of reaction centers at a given detergent concentration.
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  • 99
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    Archives of microbiology 129 (1981), S. 129-134 
    ISSN: 1432-072X
    Keywords: Cockroach ; Hindgut ; Distribution ; Microbial morphotypes ; Transmission ; Electron microscopy ; Statistical analysis ; Eublaberus posticus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The relative numbers of fourteen microbial morphotypes in transmission electron micrographs of the hindgut of a cockroach, Eublaberus posticus, were counted and their distribution was analyzed statistically. The microbiota of three wall-associated regions (the anterior paunch, the posterior paunch, and the black band region) was clearly different from that of the gut lumen. The three wall fractions were also significantly different from each other. Only one of the fourteen types, prosthecate bacteria, appeared to be distributed randomly in the four fractions. The five main wall-associated morphotypes individually constituted up to 41% of the microbes in some micrographs. They included one type with the characteristic morphology of Methanospirillum. Six morphotypes rarely made up over 2% of the population, but were consistently present. The numbers of the remaining three morphotypes were quite variable between micrographs and between individual insects, but when present often made up 5–10% of the population.
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  • 100
    ISSN: 1432-072X
    Keywords: Biological control ; Cyanobacteria ; Electron microscopy ; Entrapment ; lysis ; Myxococcus ; Phormidium ; Spherule
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A Myxococcus xanthus isolate from a farm drainage ditch, designated strain PCO2, is capable of rapidly inducing lysis of both agar and liquid-grown cultures of the cyanobacterium, Phormidium luridum, var. olivacea. Microscopic studies of the predator-prey interaction demonstrate that lysis of the cyanobacterium occurs within clumps and spherules formed by the cells of M. xanthus PCO2. In the earliest stage, one sees the formation of irregular microclumps of bacteria and cyanobacterial filaments. As these clumps mature, colonies 1 to 6 mm in diameter develops. The center of these densely green colonies contains cyanohacteria in various stages of degradation, while the periphery is almost exclusively a tightly woven mass of myxobacterial cells. Electron microscopy shows that long extrusions from the outer membrane of the M. xanthus PCO2 cells are involved in the formation both of initial clumps and of mature colonial spherules. These extrusions appear to efficiently entangle the cyanobacterial filaments in the culture environment. Predator-to-prey ratios of 1/10, 1/100 and 1/1,000 have resulted in cyanobacterial lysis. Because the entrapment and lysis of P. luridum filaments by M. xanthus PCO2 appears to be independent of any other heterotrophic nutritional requirement, as well as of environmental agitation, this system has potential as a biological control technique for undesirable aquatic cyanobacteria.
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