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  • 1980-1984  (6,680)
  • 1905-1909  (1,027)
  • Organic Chemistry  (4,433)
  • Physics  (2,657)
  • Rat  (616)
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  • 101
    ISSN: 1432-2072
    Keywords: Catecholamines ; Cerebroventricular perfusion ; Carbamazepine ; Imipramine ; Desmethylimipramine ; Tranylcypromine ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Concentrations of endogenous norepinephrine, dopamine and epinephrine in cerebroventricular perfusates were used to evaluate the effects of drugs on the availability of extracellular catecholamines in the intact rat brain. Administration of the antidepressant drugs imipramine, desmethylimipramine or tranylcypromine resulted in marked increases of both norepinephrine and dopamine concentrations while epinephrine levels were not affected. Treatment with a similar dose of carbamazepine — an anticonvulsant drug with antidepressant activity — resulted in a significant increase in dopamine concentrations without apparent effect on either norepinephrine or epinephrine. It is suggested that at the applied dose, carbamazepine may act to modify the uptake, release or metabolism of dopamine in brain areas adjacent to the cerebroventricular space without affecting the other catecholamines.
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  • 102
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    Journal of cancer research and clinical oncology 108 (1984), S. 56-59 
    ISSN: 1432-1335
    Keywords: DNA methylation ; Rat ; Procarbazine
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The cytostatic drug procarbazine has previously been shown to be a potent transplacental neurotropic carcinogen in rats. Following a single IP administration of (14C-methylprocarbazine (110 mg/kg) on day 22 of gestation, methylation products with cellular DNA were determined in fetal and maternal rat organs. The concentration of the major adduct N7-methylguanine was highest in the maternal liver (224 μmol/mol guanine). Fetal and nonhepatic maternal tissues exhibited significantly lower levels, but differed little from each other. In brain, lung, intestines, and placenta the O 6-methylguanine/N7-methylguanine ratio was close to 0.11, indicating that procarbazine, like other methylating carcinogens, initiates malignant transformation via methyldiazonium hydroxide as the ultimate reactant. Following a single dose of (14C-methyl)procarbazine to newborn animals, methylpurine values were 30–60 times lower than after prenatal administration. This suggests that DNA alkylation in nonhepatic tissues occurs by systemic distribution of a proximate carcinogen formed in the adult rat liver.
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  • 103
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    Journal of cancer research and clinical oncology 108 (1984), S. 114-120 
    ISSN: 1432-1335
    Keywords: Nasal cavities ; Rat ; DOPN
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Weekly SC administration of 2,2-dioxopropylnitosamine to 88 Sprague-Dawley rats resulted in the induction of 76 separate neoplasms in the respiratory region of the nasal cavities. No tumors of the olfactory region were found. Histologically there were 37 squamous papillomas, 17 transitional papillomas, and 22 squamous cell carcinomas. These tumors were compared with a selected group of 53 related human tumors of the nasal and paranasal cavities, consisting of 11 squamous cell papillomas, 13 transitional papillomas, and 29 squamous cell carcinomas. While the experimental squamous cell papillomas showed a striking histological resemblance with the squamous papillomas observed in man, none of the experimental transitional papillomas had evidence of the characteristics inverted pattern seen in humans: nevertheless, the experimental tumors showed signs of incomplete squamous metaplasia and preservation of intraepithelial secretory glands, features commonly seen in transitional papillomas of man. The squamous cell carcinomas of this experiment were very similar to the corresponding human tumors in morphology and sex incidence. In both species a significant number of squamous cell carcinomas were keretinizing and of a high grade of histological malignancy. In addition, 69% of the human squamous cell carcinomas occurred in the male sex, and 72% of the experimental carcinomas developed in males. This comparative study suggests that further studies investigating the significance of nitrosamines as suspected etiologic factors of nasal carcinogenesis in man may be useful.
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  • 104
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    Acta neuropathologica 63 (1984), S. 57-65 
    ISSN: 1432-0533
    Keywords: Fetal alcohol syndrome ; Rat ; Cerebellum ; Purkinje cells ; Synaptic maturation ; Metabolism
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Fetal alcohol syndrome was produced in rats by feeding an ethanol-enriched, vitamine-supplemented liquid diet over a period of 4 weeks before mating and throughout pregnancy. The amount of ethanol was equivalent to 38–40% of the daily calories; control animals were fed an isocaloric amount of sucrose. The offspring of experimental animals displayed a diminished birth weight. In contrast to previous experiments, the ethanol diet was also administered during the lactating period. On postnatal day 7, experimental animals and controls were killed by perfusion and the cerebella prepared for electron microscopy. Morphometric analysis showed a reduced number of Purkinje cells. On day 12, Purkinje cells of experimental animals displayed ultrastructurally fewer organelles. Furthermore, a delayed synaptogenesis in the molecular layer was demonstrated with osmiumzinc iodide and ethanolic phosphotungstic acid showing an immature appearance of the presynaptic grid and weaker stained synaptic cleft material. The following discussion deals with possible mechanisms underlying these alcohol-induced alterations of cerebellar synaptogenesis.
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  • 105
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    Acta neuropathologica 64 (1984), S. 192-202 
    ISSN: 1432-0533
    Keywords: Astrocytoma ; Blood-brain barrier ; HVEM ; Transendothelial channels ; Protein tracer ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Brain tumors, benign and malignant, are characteristically more permeable to various types of tracer molecules than the neuropil in which they are embedded. Impermeability of brain neuropil capillaries is imparted by the blood-brain barrier, the anatomic basis of which is the network of interendothelial zonulae occludentes that seal capillary endothelial cells. To explore both the vascular elements of brain neoplasms and the route of tracer extravasation from them, as well as the possible effects of brain tumors on the permeability of peritumoral neuropil capillaries, brain tumors were induced in newborn Wistar rats by intracerebral (i.c.) injection of C-6 astrocytoma cells. The protein tracer horseradish peroxidase (HRP) was injected systemically into both normal and tumorbearing rats to mark the pathway along which it flowed into the tumor parenchyma tissue spaces, and to signal any concomitant tracer loss from the tumor extracellular compartment or peritumoral brain capillaries, into the neuropil extracellular milieu. Electron-microscopic examination on thin plastic sections of tumor and peritumoral neuropil revealed massive extravasation of tracer into the tumor tissue spaces, but none was seen outside of the capillaries in the surrounding brain neuropil. Zonulae occludentes of both tumor capillary endothelium and brain capillary endothelium were devoid of tracer and judged tight (sealed). Tracer was seen in pinocytotic vesicles in the highly attenuated endothelium of tumor capillaries and also in cytoplasmic vesicles within the tumor cells. The peritumoral and contralateral neuropil capillary endothelium exhibited reaction product-filled pinocytotic vesicles and vesiculo-tubular conduits. Often, one end of a HRP-filled vesiculo-tubular channel appeared continuous with either the luminal or abluminal plasmalemma. High-voltage electron microscopy of these conduits often showed them to be continuous with both luminal and abluminal surfaces of the endothelium, thus forming a continuum across the capillary wall. In addition, these transendothelial channels, clearly constituted as chains of fused vesicles, were often seen in close proximity to, or fused with, dense bodies in the endothelial cytoplasm. In spite of the presence of HRP-filled structures in the peritumoral neuropil capillary endothelium of tumor-bearing rats, no evidence of tracer extravasation from these vessels was apparent. These results suggest that although peritumoral and contralateral neuropil capillaries possess the machinery for extravasation of tracer, likely as a response to the presence of the neoplasm, tracer is not lost but, instead, is degraded by endothelial enzymes. The extensive flooding of the tumor extracellular compartment with tracer may be achieved by transport of HRP across the very thin walls of tumor capillaries by single cytoplasmic vesicles which structurally and functionally play the role of transendothelial channels. Based on the results of this study, it is unlikely that molecules delivered systemically to treat brain neoplasms, will leak into the peritumor or contralateral neuropil, either from their own capillaries, or from the extracellular compartment of the tumor parenchyma.
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  • 106
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    Acta neuropathologica 62 (1984), S. 276-283 
    ISSN: 1432-0533
    Keywords: Rat ; Brain ; Lead intoxication ; Protein deprivation ; Growth and development
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Most studies on lead toxicity in the suckling rat have been performed with doses leading to growth retardation. In a previous paper (Sundström et al. 1983), the effects of different lead doses on normal suckling rats were described. The dose of 10 mg/kg body weight daily given on days 1–15 pp produced minute hemorrhagic lesions on day 15 in the cerebellum, whereas rats given 5 mg/kg body weight daily lacked microscopically discernible pathologic changes in the brain. None of these groups exhibited growth retardation. To further elucidate the association between lead encephalopathy and malnutrition, lead was administered to protein-deprived suckling rats. Protein deprivation was achieved by a diet with 50% reduction of protein content. The móthers of the pups were fed this diet from 2 weeks before conception throughout the experiment. Experimental animals were injected i.p. with 5 mg or 10 mg lead nitrate/kg b.wt. daily. Littermates, injected with vehicle without lead nitrate served as controls. Protein-deprived rats without either treatment were “external” controls. Animals were killed at 10, 15, and 20 days age for determination of lead content in blood and brain and for light-microscopic examination. The protein-deprived rats given 10 mg/kg b.wt. daily were growth-retarded as compared to unexposed protein-deprived rats. The mortality was almost 100% at 15–20 days pp. At 15 days, the cerebellum of these rats showed abundant hemorrhages, and the cerebrum was also hemorrhagically discolored. Protein-deprived rats given 5 mg/kg b.wt. daily did not differ significantly from unexposed protein-deprived rats with regard to body weight gain. They presented a mortality of about 20% on days 15–20. At 15 days, cerebellar hemorrhages were a regular finding, though not as devastating as in the animals given 10 mg lead nitrate/kg b.wt. daily. The results imply an increased vulnerability to lead in protein-deprived rats as compared to normal rats. The severe encephalopathy in protein-deprived rats was associated with higher blood lead levels than in normal rats exposed to an equivalent lead burden.
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  • 107
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    Acta neuropathologica 64 (1984), S. 139-147 
    ISSN: 1432-0533
    Keywords: Cerebral ischemia ; Cell death ; Endoplasmic reticulum ; Hippocampus ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary An unusual, slowly progressing neuronal damage has been reported to occur in the gerbil hippocampus following ischemia (Kirino 1982). Delayed neuronal death following ischemia has also been noticed in the rat four-vessel occlusion model (Pulsinelli et al. 1982). By light microscopy this slow neuronal injury in the rat was not different from the previously known neuronal ischemic cell change. This report lead us to the question as to whether neurons in the rat hippocampus are damaged rapidly following an initial latent period or deteriorate slowly and progressively until they display overt changes. To clarify this point, observation was done on the hippocampal CA1 sector of the rat following ischemia. Rats were subjected to four-vessel occlusion, and those which developed ischemic symptoms were perfusion-fixed. Although the change appeared very slowly and lacked microvacuolation of the cytoplasm, neuronal alteration was practically not different from classical ischemic cell change. By electron microscopy, however, the change was detectable when the neurons still appeared intact by light microscopy. An increase in the membranous organelles and deposition of dark substances were the initial manifestations. It seemed that the CA1 neurons deteriorated very slowly and progressively, and that they retained partial viability in the initial phase of the change. In spite of the difference in light-microscopic findings, the mechanisms underlying delayed neuronal death in the rat and gerbil hippocampus seemed to be identical.
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  • 108
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    Journal of chemical ecology 10 (1984), S. 1007-1018 
    ISSN: 1573-1561
    Keywords: Rat ; Rattus norvegicus sp. ; odorants ; stress ; behavior ; open field ; corticosterone ; fox dropping ; ketone ; sulfur ; compounds ; tans ; mercaptoketones ; repellent ; structure-activity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The stress for 12 sulfur-containing synthetized volatiles was evaluated in male Wistar rats and compared to that for fox-dropping extract concentrate. Stress behavior was analyzed by quantifying various stress responses in a standard open field and measuring the increase in plasma corticosterone concentration. Nine compounds induced stress—a dihydrothiazole, two cyclic polysulfides, five mercaptoketones, and a mercaptan. For the mercaptoketones, the following structure-activity relationships were observed. Size can vary considerably; the mercapto group can be either alpha or beta and either secondary or tertiary. The keto group is not essential, since a structurally related mercaptan remains active. The mercapto group is essential for activity in mercaptoketones, since conversion to a methyl sulfide resulted in a neutral response. This type of odorant could function as an allomone and may have potential in rat control as an area repellent.
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  • 109
    ISSN: 1435-2451
    Keywords: Hyperthermia ; Induced colonic carcinoma ; Rat ; Chemotherapy ; BCNU ; Ftorafur
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Hyperthermie zur Behandlung von Tumoren wird seit längerem in In-vitro- und In-vivo-Versuchen und auch in der Klinik in verschiedenen Anwendungsformen erprobt. Bei der Kombination von Hyperthermie mit Chemotherapie wird eine überadditive cytostatische Wirkung beschrieben. In einem klinisch orientierten, kontrolliert durchgeführten Tierversuch wurde an einem durch N-Nitrosoacetoxymethylmethylamin (AMMN) induzierten autochthonen Coloncarcinom bei Sprague-Dawley-Ratten eine lokale, moderate Hyperthermie (43,5°C, 3 × 60 min) und eine Kombinationsbehandlung von Hyperthermie und Polychemotherapie (BCNU und Ftorafur) durchgeführt unter endoskopischer Diagnosestellung und Verlaufskontrolle. Es konnte keine Überlebenszeitverlängerung durch die angewendeten Therapien und keine additive Wirkung der lokalen moderaten Hyperthermie in Kombination mit der Chemotherapie bei diesem „harten”, d. h. relativ chemotherapieresistenten, Tumormodell gesehen werden.
    Notes: Summary The use of hyperthermia for the treatment of tumors has been tested in in vitro and in vivo experiments as well as clinically for a long time. Combination of hyperthermia with chemotherapy was reported to result in overadditive cytostatic effects. In a clinically adapted, controlled animal experiment, local moderate hyperthermia (43.5°C, 3 × 60 min) alone and in combination with polychemotherapy (BCNU and Ftorafur) was used for the treatment of AMMN-(N-nitrosoacetoxymethyl-methylamine) induced autochthonous colonic carcinomas in Sprague-Dawley rats. Diagnosis and follow-up inspections were carried out endoscopically. The applied therapies did not result in prolonged survival times, nor was an additive effect seen after combined hyperthermia and chemotherapy in this “hard”, i. e. relatively chemotherapy-resistent, tumor model.
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  • 110
    ISSN: 1435-2451
    Keywords: Hyperthermia ; Yoshida sarcoma ; Chemotherapy ; BCNU ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Hyperthermie zur Cytostase von Malignomen ist in zahlreichen In-vitro- und In-vivo-Untersuchungen beschrieben worden. Die Kombination von Chemotherapie mit Hyperthermie soll zur Potenzierung der therapeutischen Wirkung führen. Ein Forschungsgegenstand ist der zeitliche Abstand zwischen beiden Therapiemodalitäten. Anhand eines Yoshida-ColonModells bei Sprague-Dawley-Ratten wurde eine lokale Hyperthermie (43°C, 60 min) im Abstand von 0, 3, 6, 9, 12 und 24 h nach einer Chemotherapie mit BCNU durchgeführt. Die Ergebnisse zeigten keine signifikante Steigerung der Heilungsrate durch die Hyperthermie. Angesichts unserer Ergebnisse sollten z.B. die mit groben Hoffnungen propagierten hyperthermen Peritoneallavagen erst im Tierexperiment einer kontrollierten Untersuchung unterzogen werden.
    Notes: Summary There are numerous reports on in vitro and in vivo investigations of hyperthermia for cytostasis of malignant tumors. Combination of chemotherapy and hyperthermia is to potentiate the therapeutic effect. The time interval between the two types of therapy was the main subject of the present investigation. Local hyperthermia (43°C, 60 min) following BCNU chemotherapy at intervals of 0, 3, 6, 9, 12, and 24 h, respectively, was studied in a colonic Yoshida sarcoma model in Sprague-Dawley rats. No significant increase in the curing rate resulted from hyperthermic treatment. The results suggest that the highly anticipated hyperthermic peritoneal lavages should be investigated in controlled animal experiments prior to clinical use.
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  • 111
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    European journal of applied physiology 52 (1984), S. 235-242 
    ISSN: 1439-6327
    Keywords: Collagen ; Fast and slow twitch fibres ; Skeletal muscle ; Rat ; Endurance training
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The appearance of collagen around individual fast twitch (FT) and slow twitch (ST) muscle fibres was investigated in skeletal muscles with different contractile properties using endurance trained and untrained rats as experimental animals. The collagenous connective tissue was analyzed by measuring hydroxyproline biochemically and by staining collagenous material histochemically in M. soleus (MS), M. rectus femoris (MRF), and M. gastrocnemius (MG). The concentration of hydroxyproline in the ST fibres dissected from MS (2.72±0.35 Μg·mg−1 d.w.) was significantly higher than that of the FT fibres dissected from MRF (1.52±0.33 Μg·mg−1 d.w.). Similarly, the concentration of hydroxyproline was higher in ST (2.54±0.51 ⧎g·mg−1 d.w.) than in FT fibres (1.60±0.43 Μg·mg−1 d.w.), when the fibres were dissected from the same muscle, MG. Histochemical staining of collagenous material agreed with the biochemical evidence that MS and the slow twitch area of MG are more collagenous than MRF and the fast twitch area of MG both at the level of perimysium and endomysium. The variables were not affected by endurance training. When discussing the role of collagen in the function of skeletal muscle it is suggested that the different functional demands of different skeletal muscles are also reflected in the structure of intramuscular connective tissue, even at the level of endomysial collagen. It is supposed that the known differences in the elastic properties of fast tetanic muscle compared to slow tonic muscle as, e.g., the higher compliance of fast muscle could at least partly be explained in terms of the amount, type, and structure of intramuscular collagen.
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  • 112
    ISSN: 1432-0878
    Keywords: Caldesmon ; Actin ; Immunocytochemistry ; Small intestine ; Smooth muscle ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The distribution of caldesmon (a calmodulin-binding, F-actin-interacting protein) (Sobue et al. 1982) and of actin was studied in the rat's small intestine by means of light-microscopic immunocytochemistry. Positive immunostaining for caldesmon was seen in smooth muscle cells of the intestinal wall, and of blood vessels, and in the apical portion of the absorptive epithelial cells. The immunoreactivity in goblet cells was difficult to recognize. The positive reaction to immunostaining for actin showed almost the same pattern as that for caldesmon. These results suggest that this calmodulin-binding protein may play an important role in the control of actin-myosin interaction in smooth muscle cells and in non-muscle cells.
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  • 113
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    Cell & tissue research 235 (1984), S. 485-489 
    ISSN: 1432-0878
    Keywords: Ventromedial nucleus ; Hypothalamus ; Ultra-structure ; Nucleoli ; Estrogen effects ; Chromatin ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Estrogen is accumulated from the blood by nerve cells in the ventromedial nucleus of the hypothalamus and can facilitate female reproductive behavior by acting on this region of the brain. This cell group was examined in ovariectomized female rats, given estrogen or control treatment, by use of light and electron microscopy. A significantly greater portion of the nerve cells in the estrogen-treated animals had protuberances on their nucleolar surfaces, apparent under the light microscope. The fine structure of such protuberances included dense, aggregated material, which is shown to contain DNA by the sodium tungstate staining technique. Because increased numbers of such protuberances were found in nuclei of cells of the experimental group where previous studies demonstrated a significant increase in ultrastructural signs of biosynthetic activity, they may be associated with increased RNA synthesis. Thus, they could indicate, ultrastructurally, increased synthetic rates for RNA in nerve cells through which estrogen promotes reproductive behavior.
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  • 114
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    Cell & tissue research 235 (1984), S. 669-673 
    ISSN: 1432-0878
    Keywords: Liver-cell heterogeneity ; Hepatic venous branches ; Karyometry ; Binucleate cells ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary In untreated adult male albino rats nuclear volume and the percentage of binucleate cells were determined in the first layer of hepatocytes adjacent to hepatic venous branches of varying diameters (〈40 μm, 40 μm–80 μm, 80 μm–120μm, 120 μm–160 μm, 〉160 μm), and in the third and fourth layer of hepatocytes in the remainder of the perivenous parenchyma. In the first layer of hepatocytes adjacent to the vascular structures means of nuclear volume are significantly lower and percentage of binucleate cells significantly higher than in the cells of the remainder of the perivenous parenchyma. Within each area measured distribution curves of nuclear volume classes were homogeneous but showed heterogeneity in comparison with each other. The morphometric data presented in this study strongly support the opinion of the heterogeneity of liver cells in the perivenous zone, as previously postulated on the basis of histochemical investigations.
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  • 115
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    Cell & tissue research 236 (1984), S. 305-315 
    ISSN: 1432-0878
    Keywords: Hepatocytes ; Rat ; Liver ; Circadian rhythm ; Morphometry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Subcellular structures of hepatocytes in periportal and perivenous zones were examined during 24 h. The volume, surface and numerical profile densities of cytoplasmic organelles were analysed morphometrically. Most subcellular structures in periportal and perivenous hepatocytes were subject to strong circadian variations. In hepatocytes from both zones, the volume densities of smooth endoplasmic reticulum (sER), mitochondria, lysosomes, peroxisomes, polysomes and lipid droplets demonstrated peak values at 16.00 h, 20.00 h or 00.00 h; trough values were at 04.00 h, 08.00 h, or 12.00 h, except for peroxisomes (16.00 h). However, the volume densities of glycogen granules and rough endoplasmic reticulum (rER) in periportal and perivenous hepatocytes exhibited maximal values at 04.00 h, 08.00 h or 12.00 h and minimal values at 20.00 h. The surface densities of sER, mitochondria, lysosomes and peroxisomes, and the numerical profile densities of mitochondria, lysosomes and peroxisomes in periportal and perivenous hepatocytes showed similar trends. These events suggest that membranes of the rER show a partial correlation with the sER, mitochondrial and lysosomal membranes during the 24-h span. This may involve the interaction between ribosomes and rER. Almost all cytoplasmic organelles examined displayed significant differences between periportal and perivenous hepatocytes, morphometrically and in fine structure, indicating that the morphofunctional variability of hepatocytes differs depending on the location in the liver acinus.
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  • 116
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    Cell & tissue research 236 (1984), S. 321-325 
    ISSN: 1432-0878
    Keywords: Triiodothyronine ; Radioautography ; Mitochondria ; Liver ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary To assess the distribution of the thyroid hormone triiodothyronine (T3) within intact living cells, freshly prepared dispersed rat hepatocytes were incubated with [125I]-T3 for periods of 5 min and 30 min. Lightand electron-microscopic (EM) radioautography was carried out to determine the distribution of grains over the isolated cells. Both procedures showed the grains distributed almost entirely over the cytoplasmic matrix rather than the nucleus. Grain counts under the EM were compared with expectation based on established quantitative methods. Only the mitochondria showed obvious and statistically significant grain counts, whereas the nucleus failed to accumulate grains in excess of expectations by chance alone based on area. The findings support the existence of mitochondrial binding of T3, presumably a prerequisite for its action in direct stimulation of the mitochondria.
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  • 117
    ISSN: 1432-0878
    Keywords: Lymph node ; Steroids ; Macrophages ; Intercellular junctions ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Intercellular junctions were often found between macrophages in sinuses of regional lymph nodes of the rat after injection of large doses of cholesterol, cortisone acetate, and estrone at the footpad. They were identified by subplasmalemmal densities, 20–50 nm in width, beneath the plasma membranes of apposed macrophages. No distinct filamentous structures were visible in those dense regions. Electron-dense amorphous materials are lined up at the center of the intercellular space in the junctional regions. Some macrophages form clusters with intercellular junctions. No significant difference in the effect of cholesterol, cortisone acetate, and estrone on the number of intercellular junctions betwene macrophages was found.
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  • 118
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    Cell & tissue research 236 (1984), S. 373-381 
    ISSN: 1432-0878
    Keywords: Merkel cell surface ; Quinacrine fluorescence ; Lectins ; Vibrissae ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Surface carbohydrates on the Merkel cell of the outer root sheath (ORS) were investigated in 1to 4-day-old rat vibrissae by use of rhodamine isothiocyanate (RITC)-conjugated lectins. The red fluorescence of RITC provided a convenient assay for lectin binding to the Merkel cell, which is itself identified by its green fluorescence following selective uptake of the dye quinacrine. In monolayers or suspensions of freshly dissociated ORS cells, the Merkel cell showed high affinity for the α-fucose-specific lectin, Ulex europeus agglutinin I (UEA-I), thus revealing a novel feature for a basally located cell. Other high-affinity lectins included concanavalin A (Con A), wheat germ agglutinin (WGA), soybean agglutinin (SBA), and Ricinus communis agglutinin I (RCA-I). In contrast, Dolichos biflorus (DBA), Bandeiraea simplicifolia I and II (BS-I and BS-II), and peanut agglutinin (PNA) virtually excluded the Merkel cell, though PNA-binding sites were unmasked after neuraminidase treatment. Other dispersed ORS cells had varying lectin affinities, and generally binding was inhibited by a competing haptenic sugar. The pattern of lectin binding seen in cryostat and paraffin sections of the vibrissa suggested that the Merkel cells share surface properties with their neighboring basal and/or spinous cells; however, unshared properties are likely to exist since ingrowing mechanosensory nerves recognize the Merkel cells, and not other epidermal cells, as their targets.
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  • 119
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    Cell & tissue research 236 (1984), S. 491-493 
    ISSN: 1432-0878
    Keywords: Brain vessels ; Basal lamina ; Pericytes ; Endothelial cells ; Glial cells ; Argyrophilic staining ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Vibratome sections obtained from perfusion-fixed rat brains were stained by means of silver impregnation and physical development according to Gailyas (1970). Small pieces of the cerebral cortex were postfixed with buffered osmium tetroxide solution and processed for electron microscopy to examine the localization of the silver deposit at the cellular level. The cell surfaces of pericytes and smooth muscle cells were completely outlined by silver grains. Endothelial cells and perivascular astrocytes, however, showed an asymmetric distribution of the silver deposit, i.e., the deposit was restricted to the abluminal endothelial surface and to the astrocytic membrane adjacent to the vessel wall, respectively. The method allowed a clear-cut distinction between perikarya of endothelial cells and pericytes as well as glial cells in perivascular position, even at the light-microscopic level.
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  • 120
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    Cell & tissue research 236 (1984), S. 561-566 
    ISSN: 1432-0878
    Keywords: Pituitary gland, pars intermedia ; Peptide hormones ; Dopamine ; Corticotropin-releasing hormone ; 6-Hydroxydopamine ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary When rats were injected with 6-hydroxydopamine the catecholaminergic nerve terminals in their intermediate lobes exhibited distinct signs of degeneration. Morphometric examination of the Golgi apparatus in cells of the intermediate lobe of these rats showed significant enlargement of Golgi cisternae. The release of adrenocorticotropin, β-endorphin/lipotropin and α-melanotropin from intermediate-lobe cells in vitro was measured by radioimmunoassay. The high basal peptide release was inhibited by dopamine and stimulated by methyl-isobutyl-xanthine. In contrast, γ-aminobutyric acid, serotonin, histamine and noradrenaline, or corticotropin-releasing hormone, rat hypothalamic extract and vasopressin had no or only very weak effects. These observations indicate that the synthetic apparatus of intermediate-lobe cells is constantly depressed by dopaminergic nerves. We were not able to stimulate peptide release from intermediate-lobe cells by use of the abovementioned endogenous agents.
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  • 121
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    Cell & tissue research 236 (1984), S. 711-715 
    ISSN: 1432-0878
    Keywords: Gastric antral mucosa ; Caerulein ; Gastrointestinal hormones ; Cholecystokinin ; Trophic effect ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The growth-promoting effect of caerulein on antral gastric mucosa was explored using Wistar rats. Implanted osmotic minipumps were used to administer submaximal doses of either caerulein or saline to normal rats for up to 4 days. In one group, reflux of bile and pancreatic juice into the stomach was avoided by previous surgical diversion of the distal common bile duct to the jejunum. DNA synthetic and mitotic activity in the antrum epithelium were estimated by 3H-thymidine pulse labelling and autoradiography during the administration of the peptide. The rate of cell migration was determined in animals killed 1, 2 and 3 days after the 3H-thymidine pulse. Administration of caerulein to normal rats provoked significant increases in both labelling and mitotic indices, and a significant acceleration of the upward cell migration in the glandular tubes. In the animals with distal diversion of bile and pancreatic secretions both labelling and mitotic indices were also increased over control values under the effect of the peptide. These data indicate that administration of caerulein stimulates cell proliferation in the antral gastric mucosa. This effect cannot be explained through increased reflux of pancreaticobiliary secretions in the stomach.
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  • 122
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    Cell & tissue research 236 (1984), S. 699-709 
    ISSN: 1432-0878
    Keywords: Testis ; Spermatogenic cycle ; Sertoli cell ; Lipid ; Morphometry ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The volume and surface area of lipid inclusions often present in the cytoplasm of rat Sertoli cells was measured directly from semi-thin sections of perfusion-fixed testicular tissues using an image analyser linked to a light microscope. Sertoli cell nuclei were used as a reference for comparing any variations in the measured parameters of lipid inclusions during the rat spermatogenic cycle. Volume density of Sertoli cell lipid inclusions was assessed by morphometric analysis of Sertoli cells photographically reconstructed from electron micrographs. Maximum lipid content in Sertoli cells occurred during stages IX–XIV of the spermatogenic cycle, then declined at stages I–III and remained low from stages IV–VIII. The persistence and increase in number of many large Sertoli cell lipid inclusions beyond the stage where spermatid residual bodies are phagocytosed within the Sertoli cells (stage IX) suggests that the synthesis and lipolysis of Sertoli cell lipid inclusions represents an intrinsic functional cycle of the Sertoli cells. Stage-dependent variations in the lipid content of rat Sertoli cells offers morphological evidence that the metabolic duties of the Sertoli cells are synchronised with the spermatogenic cycle to provide local coordination of the proliferation and maturation of the germ cells.
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  • 123
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    Cell & tissue research 236 (1984), S. 717-724 
    ISSN: 1432-0878
    Keywords: Ovary ; Ovarian follicle ; Atresia ; Immunoregulation ; Immune tolerance ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Thy-1+ cells, producing Thy-1+ material, have been demonstrated by the indirect immunoperoxidase technique in the theca of growing ovarian follicles of the rat. OX-2 antigen, known as the minor glycoprotein of rat thymocytes, was detected in granulosa cells of non-growing follicles. Ia+ cells of dendritic type and/or activated macrophages were identified in the granulosa of advanced degenerating follicles, and remnants of the zona pellucida exhibited immunoglobulins. In some ovaries immunoglobulins were also bound to the zona pellucida of oocytes of early degenerating antral follicles. Medium-sized antral follicles with degenerating granulosa were occasionally invaded by cells carrying antigens of cytotoxic T lymphocytes or other T lymphocyte subsets, while degenerating large antral follicles were sometimes invaded by cells exhibiting antigen of cells with natural killer function (but not antigens of T lymphocytes). Granulosa cells of some degenerating antral follicles exhibited class-I antigens derived from the major histocompatibility complex. We suggest that cell-mediated control mechanisms of antigen expression and metabolism of tissue cells during their differentiation and degeneration should be considered in addition to the well-documented hormonal dependence of some tissues.
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  • 124
    ISSN: 1432-0878
    Keywords: Exocrine pancreas ; Calcium pool ; Calcium release ; Electron microscopy ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary In an attempt to identify a cellular Ca2+-pool, from which calcium is released when secretagogues are applied, tissue fragments of the rat exocrine pancreas were incubated and fixed with glutaraldehyde in the presence of calcium. By means of this procedure electron-dense deposits were found on plasma membranes. X-ray microanalysis showed that these deposits contain calcium. Stimulation of tissue fragments with the use of the secretagogues carbachol or cholecystokinin reduced the number of deposits by about 80%. When the antagonist atropine was applied after carbachol stimulation, deposits reappeared on cell membranes, which then disappeared again after a second stimulation with cholecystokinin. In the presence of procaine, carbachol was inhibited and only slightly reduced the Ca2+-deposits on the plasma membranes. These results suggest that a calcium pool, from which calcium is released to induce enzyme secretion on stimulation, is located in the cell membrane
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  • 125
    ISSN: 1432-0878
    Keywords: Thyroid gland, fetal ; Cytoskeleton ; Cytocha lasin B ; Vinblastine ; Colchicine ; Follicular development (thyroid) ; Tissue culture ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Thyrotropic hormone (TSH) or cAMP accelerate the formation of follicular cavities in the explanted thyroid gland of the 15-day-old rat fetus. Cytochalasin B or vinblastine and nocodazole or colchicine, which disorganize microfilamental and microtubular structures respectively, inhibit or completely block in vitro-induced folliculogenesis. Exposure of the thyroid tissue to lumicolchicine, a structural isomer of colchicine deprived of antimicrotubular activity, does not inhibit the activation of folliculogenesis induced by TSH. These results are strong evidence for the supposition that microfilaments and microtubules are involved in the TSH-stimulated mechanisms resulting in thyroid folliculogenesis. Folliculogenesis requires the integrity of both microfilaments and microtubules.
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  • 126
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    Cell & tissue research 236 (1984), S. 171-180 
    ISSN: 1432-0878
    Keywords: Immunocytochemistry ; Ultrastructure ; Supraoptic nucleus ; Neuropil ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The neuropil located ventral to the SON was investigated by the use of immunoperoxidase staining for neurophysins, oxytocin and vasopressin, and electron miroscopy. The study was performed in six groups of rats: 1) control; 2) infusion of isotonic saline into the CSF; 3) infusion of hypertonic saline into the CSF; 4) drinking hypertonic saline for 4 days; 5) same as group 4 but injection of colchicine into the CSF on second day of dehydration; 6) salt loading for 3 months. In the control rats the ventral neuropil contained a few immunoreactive processes, the general morphology of which was completely different from that of the neurosecretory axons emerging from the SON at its dorsal aspect. In rats of groups 3 to 6 the ventral processes (VP) became loaded with neurosecretory granules, whereas the perikarya and axons were depleted. Based on their general morphology and reactivity pattern it is suggested that the VP are dendrites. Most of these “dendrites” were embedded in a glial cushion formed by the processes of a particular type of marginal glia. Some of these “dendrites” enveloped an arteriole penetrating the optic tract. All VP were rich in synaptic contacts. The possibility that the VP of neurosecretory cells may be functionally related to the subarachnoid CSF and the arteriolar blood flow is discussed.
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  • 127
    ISSN: 1432-0878
    Keywords: Sympathetic ganglion ; Development, ontogenetic ; Corticosteroid treatment ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Hydrocortisone injections into rats on postnatal days 3–9 caused an increase in the number of small granulecontaining cells in the superior cervical ganglia. These cells, corresponding to the small, intensely fluorescent cells, showed an extensive rough endoplasmic reticulum, a large Golgi apparatus and a very large number of granular vesicles. In addition to the granular vesicles, 70–160 nm in diameter, in which the dense core filled most of the vesicle, most cells of the hydrocortisone-injected rats contained also larger granular vesicles, up to 350 nm in diameter, in which the dense core was eccentrically located. A minority of the cells contained only granular vesicles 70–100 nm in diameter, which was the only type seen in the saline-treated control rats. Thirty days after discontinuation of the hydrocortisone treatment, most of the cells with large granular vesicles had disappeared, and only two profiles of such cells were seen on day 40. The other small cells contained only granular vesicles 70–160 nm in diameter, and these cells could not be distinguished from the small granule-containing cells of 40-day-old control rats treated early postnatally with saline. Hydrocortisone treatment, first on days 3–9 and subsequently on days 40–46, caused reappearance of the small granule-containing cells with large granular vesicles up to 350 nm in diameter, the dense core of which was eccentrically located. Hydrocortisone treatment on days 40–46 only was not followed by appearance of such cells in rats treated with saline on days 3–9.
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  • 128
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    Cell & tissue research 237 (1984), S. 103-109 
    ISSN: 1432-0878
    Keywords: Synapses ; Synaptogenesis ; Development fetal ; Olfactory cortex ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Electron microscopy was used to study synaptogenesis in prepyriform cortex of fetal rat pups during early stages of synapse formation. Of special interest is the frequent occurrence of unapposed, developing synaptic specializations in axon and growth cone profiles. The location and morphology of the unapposed specializations suggests that thay are presynaptic in nature. These presumably immature presynaptic specializations are found in the lateral olfactory tract and subjacent cortex. Intermediate forms between uncontacted presynaptic specializations and definitive synapses suggest a synaptogenic sequence in which initial development of an immature presynaptic specialization begins without apposition of a postsynaptic element at that location. This implies that initiation of presynaptic development is not dependent upon postsynaptic contact and also raises the question of whether synaptic contacts could be established via presynaptic induction of postsynaptic formation.
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  • 129
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    Cell & tissue research 237 (1984), S. 169-179 
    ISSN: 1432-0878
    Keywords: Foetal pancreas ; β Cells ; Insulin ; Fasting mothers ; Morphometry ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary After maternal fasting for 72 h the pancreatic β cells of 18-day-old foetal rats show a conspicuous enrichment in secretory material, with an increase of pancreatic insulin concentration and a marked development of the rough endoplasmic reticulum and the Golgi apparatus. The morphometric analysis shows that the intracytoplasmic migration of the secretory granules is inhibited, principally inside the cell web. Consequently the number of secretory granules fused with plasma membrane decreases and this is associated with a decreased foetal plasma insulin. The difference in the ultrastructural aspect of the β cells of foetuses from fasting mothers and of foetuses from fed mothers is less conspicuous at 19 days of gestation and progressively disappears at 20 and 21 days. The modifications in ultrastructural aspect and in functional state are discussed.
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  • 130
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    Cell & tissue research 237 (1984), S. 245-252 
    ISSN: 1432-0878
    Keywords: Pineal organ ; Interstitial cells ; Astrocytes ; Immunocytochemistry ; Rat ; Mouse
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Antigenic markers characteristic of astrocytes and their differentiative states (i.e., glial fibrillary acidic protein (GFAP), vimentin, and M1 and C1 antigens) were investigated in the pineal gland of mouse and rat using double immunolabeling techniques. In both species the socalled interstitial cells as characterized by TEM were shown to be astrocytes, since they expressed vimentin, but neither fibronectin (a marker for fibroblasts and endothelial cells) nor the neuron-specific L1 antigen or tetanus toxin receptors. Subpopulations of vimentin-positive pineal astrocytes were also GFAP- and C1- antigen-positive. M1- antigenpositive cells were not detected. It is concluded that a considerable proportion of interstitial cells in the pineal gland of rat and mouse are immature astrocytes which, in contrast to other parts of the central nervous system, persist into adulthood.
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  • 131
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    Cell & tissue research 238 (1984), S. 81-85 
    ISSN: 1432-0878
    Keywords: Retina ; Ibotenic acid ; Toxicity ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary After 2 h intraocular injections of 19 and 190 nmoles ibotenic acid in the rat retina produced an intensive vacuolization of the inner plexiform layer and cellular alterations, in the inner nuclear layer and ganglion cell layer. These alterations consisted of either cytoplasmic swelling accompanied by clumping of the nuclear chromatin or darkening of the cytoplasm along with nuclear condensation. A week later the retinas were thinner than the controls due to the disappearance of the affected cells. Pre-treatment with diazepam prevents the morphological alterations induced by 19 nmoles ibotenic acid; mainly the swelling, which was completely prevented, while the darkening was reduced drastically, although some vacuolization of the inner plexiform layer is still present.
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  • 132
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    Cell & tissue research 238 (1984), S. 191-195 
    ISSN: 1432-0878
    Keywords: Glial fibrillary acidic protein (GFAP) ; Pituicytes, neonatal ; Development, ontogenetic ; Immunofluorescence ; Organ culture ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The appearance and intracellular localisation of glial fibrillary acidic protein (GFAP) in pituicytes in neural lobe cultures of newborn rats aged 7 to 30 days were investigated by use of the indirect immunofluorescence method. GFAP-immunoreactive cells were observed mostly in the outgrowth zone. GFAP was localised in the perikaryal cytoplasm as well as in pituicyte processes. GFAP-positive pituicytes showed considerable morphological polymorphism. The presence of GFAP — astrocytic marker — in pituicytes in vitro and the evident morphological similarity to cultured astrocytes suggest the astroglial character of these cells.
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  • 133
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    Keywords: Cyclic guanosine monophosphate-phosphodiesterase (cGMP-PDEase) ; New cytochemical method ; Retina ; Rods, outer segments ; Light perception ; 5′GMPase ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Cyclic guanosine monophosphate-phosphodiesterase (cGMP-PDEase) activity was studied histo- and cytochemically in the retinal rods of the rat with the use of a newly developed technique. Intense activity of cGMP-PDEase was evenly distributed over the outer segments of the rods. Reaction product was observed on the plasmalemma and on the disk membranes of the outer segments. A weak reaction product occurred also on the plasmalemma of the inner segments; however, no precipitate was found in the perinuclear and synaptic portions of the rod cells. The enzyme activity was strongly inhibited by 2 mM theophilline and by 2 mM 3-isobutyl-1-methylxanthine (IBMX). To confirm the specificity of this new cGMP-PDEase method, the localization of 5′nucleotidase (5′GMPase) was also studied. In contrast to the activity of cGMP-PDEase, the activity of 5′GMPase was distributed on the plasma membrane of the photoreceptor cells extending over a wide range from the synaptic endings in the outer plexiform layer to the tip of the outer segments.
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  • 134
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    Cell & tissue research 238 (1984), S. 459-474 
    ISSN: 1432-0878
    Keywords: Meningeal compartment ; Perivascular space ; Brain intercellular compartment ; Cerebral cortex ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The intercellular clefts of the brain and the leptomeninges, and the perivascular spaces were studied with reference to the results obtained in a previous study (Krisch et al. 1983). The spatial relationships of these compartments were analyzed at the electron-microscopic level. Horse-radish peroxidase (HRP) was injected into the brain or into the contralateral ventricle. The pattern of distribution of HRP depends on the boundary situation in the individual compartments. The inner and outer pial layers accompany the vessels intruding into the brain. In the Virchow-Robin space the pial funnel obliterates within a short distance. The inner arachnoid layer is continuous with the outer arachnoid layer when it covers the vessels traversing the meningeal space. The perivascular compartment is not in communication with the arachnoid space; moreover, the pial funnel within the Virchow-Robin space is sealed off against the arachnoid space. Thus, blood vessels traversing the meningeal spaces and subsequently penetrating the brain surface are exposed to the common intercellular compartment represented by the intercellular clefts of the brain and the leptomeninges; this compartment does not communicate with the other compartments. The cerebrospinal fluid located in this intercellular compartment is preferentially drained into the upper cervical lymph nodes.
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  • 135
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    Keywords: S-100 ; Müller cell ; Astrocyte ; Development ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The rat retina was studied by immunohistochemistry with antibody to S-100 protein during the first three postnatal weeks. Immunoreactive astrocytes are first detected subjacent to the inner limiting membrane close to the optic disc. They gradually increase in number and spread toward the ora serrata along the inner surface of the retina as the development proceeds. S-100-immunostained Müller cells are first identified on the 12th postnatal day although their immunoreactivity is much weaker than that of astrocytes at the same stage. This differential intensity of the immunoreactivity of the two cell types facilitates observation of the entire shape of the astrocyte. This characteristic reveals that cellular investments of blood vessels in the inner retina are formed by astrocytic processes whereas those in the outer plexiform layer are derived from processes of Müller cells. The cellular investment becomes complete by the 18th postnatal day.
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  • 136
    ISSN: 1432-0878
    Keywords: CRF-neurons ; Hypothalamus ; Development, ontogenetic ; Rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Appearance of immunoreactive corticotropin-releasing factor (CRF)-containing neurons was studied in developing hypothalamus of the rat by use of antisera against rat- and ovine CRF. These neurons were first recognized in the lateral and paraventricular nuclei on days 15.5 and 16.5 of gestation, respectively, when antiserum against rat CRF was employed. Antiserum against ovine CRF revealed the cells two days later exclusively in the latter nucleus. In both nuclei, the neurons increased in number with development. The neurons in the paraventricular nucleus appeared to project their immunoreactive processes to the median eminence via the periventricular and lateral pathways. In the median eminence, the immunoreaction with antiserum to rat CRF was first recognized in its anterior portion in the form of dots on day 16.5 of gestation but as beaded fibers in the external layer on day 17.5; these structures increased in amount with development in rostro-caudal direction. Although antiserum to ovine CRF was less potent in immunostainability than antiserum to rat CRF, it also revealed the beaded fibers in the median eminence on day 17.5 of gestation. Since evidence is available that the paraventricular nucleus is involved in corticotropin release, it is concluded that, in rats, the hypothalamic regulatory mechanism controlling the release of corticotropin initially appears on days 16.5–17.5 of gestation.
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    Cell & tissue research 238 (1984), S. 559-564 
    ISSN: 1432-0878
    Keywords: Adrenal cortex ; Macrophages ; Ovariectomy ; Rat ; Estradiol administration
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Macrophages of the adrenal cortex were studied in normal male and female, ovariectomized and estradiol-injected rats. In normal male rats few macrophages with numerous granules were observed in the zona fasciculatazona reticularis border, and in the zona reticularis. Granules, identified as lysosomes, were limited by a single membrane with a heterogeneous matrix; they exhibited acid phosphatase- and aminotriazole-resistant peroxidatic activities. A larger number of macrophages had identical distributions in normal female rats. In ovariectomized and estradiol-injected rats the number and distribution of adrenal macrophages were similar to those in normal females; however, in spayed animals the number of these cells in the zona reticularis was higher than in the other experimental groups. Lysosomes in macrophages of treated animals were more numerous and their contents more complex than in normal male animals. These results indicate that the adrenal macrophage system is stimulated in experimental conditions involving high levels of circulating estrogens.
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  • 138
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    Journal für Praktische Chemie/Chemiker-Zeitung 326 (1984), S. 279-286 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Convenient Synthesis of 4-Oxo-tetrahydropyrimidinesEnamino-nitriles as 6 or 11 yield 4-oxo-pyrimidines (2; 2a; 10; 12a-c) on treatment with cyclohexanone in basic media. Analogous compounds are obtained using acetone, butyraldehyde, benzaldehyde or substituted benzaldehydes.
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  • 139
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The “Normalizing Factor” for the Tomato Mutant chloronerva. XV. Peptide Analogues of the Phytosiderophore NicotianamineSome peptide analogues of the phytosiderophore nicotianamine, (2S, 3′S, 3″S)-N-[3-(3-amino-3-carboxypropylamino)-3-carboxypropyl]-azetidine-2-carboxylic acid, have been synthesized from protected amino acids by the EEDQ or the DCC method. They exhibited no biological effect with regard to the phenotypical normalization of the tomato mutant chloronerva.
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  • 140
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: 2-Aza-3-chloro-2-propeniminium salts 5, which are easily available by the addition of formamide chlorides 1 to nitriles 2 react smoothly with hydrazines 9 giving rise to 1,3-disubstituted 1,2,4,-triazoles 11. When the 2-aza-3-chloro-2-propeniminium salts 5 are hydrolysed first the resulting N-acyl-formamidinium salts 6 react with hydrazines 9 to 1,5 disubstituted 1,2,4-triazoles 13 via isolable N-acyl-formamidrazones 12.
    Additional Material: 4 Tab.
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  • 141
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    Journal für Praktische Chemie/Chemiker-Zeitung 326 (1984), S. 303-310 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Quantum Chemical Investigations of the Molecular and Electronic Structure of Simple Azomethine Imines and Related CompoundsThe molecular and electronic structure of simple azomethinimines are investigated by means of MINDO/3 and CNDO/2 calculations. The calculated molecular geometry is compared with X-ray results obtained for these compounds. Except for the NN-bond lengths MINDO/3 satisfactorily describes the molecular structure of azomethinimine and related π-electronic systems. The charges at the atoms along the conjugated chain are alternating as in polymethines. The terminal carbon atom carries a negative charge. This charge brings about an appreciable shielding of this carbon atom such as found in the 13C-n.m.r. spectrum. This result does not contradict a stabilization of azomethinimines in the crystal via = CH…O=C interactions.
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  • 142
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    Journal für Praktische Chemie/Chemiker-Zeitung 326 (1984), S. 320-328 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Synthesis of Oligodeoxyribonucleotides on a Polystyrene Grafted Polytetrafluorethylene Support via Phosphotriester Intermediates
    Additional Material: 5 Ill.
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  • 143
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    Journal für Praktische Chemie/Chemiker-Zeitung 326 (1984), S. 342-348 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Quinazolincarboxylic Acids. I. Quinazolin-4-on(2,4-dion)-3-acetic Acids and Esters
    Additional Material: 6 Tab.
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  • 144
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    Journal für Praktische Chemie/Chemiker-Zeitung 326 (1984), S. 374-380 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The effects of temperature, structure and sulphuric acid concentration on the selectivity of the oxidation of aliphatic ketones (R1COR2) (1a-g) by thallic sulphate have been investigated. With increasing temperature the quantity of internal α-hydroxyketone (3a-d) decreases and the quantity of 1-hydroxyketone (2a-d) increases in the oxidation of methyl alkyl ketones (R2〉CH3) (1a-d). The same concerns to the oxidation products of hexan-3-one (1e): 2-hydroxy-hexan-3-one (2e) and 4-hydroxy-hexan-3-one (3e), respectively. “The inverse selectivity temperature” (IST) for oxidation of linear methyl alkyl ketones (1a-c) and hexan-3-one (1e) has been found. With the use of the linear free-energy relationship it has been found that the selectivity of the reaction decreases with increasing the polar and steric effects of substituents R1, R2. With increasing the sulphuric acid concentration the selectivity of the oxidation of methyl alkyl ketones (1a, 1d) increases.
    Additional Material: 3 Ill.
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  • 145
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    Journal für Praktische Chemie/Chemiker-Zeitung 326 (1984), S. 401-406 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Electrophilic Reactions on the Maleimide Double BondThe aminosubstituted maleimides 1 are deprotonated to the anions 2, which are reacted with various electrophiles. By this way with heterocumulenes, acid chlorides and vinylogous acid chlorides the new acylated maleimides 3-6, 9, 10 are isolated. This reaction presents a method of direct acylation on the maleimide double bond.
    Additional Material: 1 Tab.
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  • 146
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    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Light Induced Polymer and Polymerization Reactions. 14. Radical Photopolymerization by Potassium Trisoxalato Cobaltate Arylonium Salts Systems.The photopolymerization of acrylamide (AA) by trisoxalato cobaltate ([Co(ox)3]3⊖) is inefficient because the produced nucleophilic ·CO2⊖-radicals are oxidized or they terminate with polymer radicals. If onium compounds are added to this system the initiation efficiency is increased as follows : p-CH3OC6H4N2⊕〉Ph2I⊕〉PhCOCH2S(CH3)2⊕〉Ph3S⊕. By means of quantum yield measurements a mechanism was proposed including the electron transfer from ·CO2⊖ to onium compounds. The produced radicals also initiate the polymerization of AA. The exponent m of the polymerization rate (vp ≍ [AA]m) is decreased from 1.4 to 1.1 in the presence of Ph2I⊕, deciding the decrease of termination reaction between ·CO2⊖ and polymer radicals. In comparison with K3[Fx(ox)3] the corresponding cobalt complex possesses higher polymerization quantum yields for AA.
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  • 147
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    Journal für Praktische Chemie/Chemiker-Zeitung 326 (1984), S. 505-510 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Hammett-like Correlations between 13C-NMR Chemical Shifts and Substituent Constants on Aniles of p-Nitrocinnamaldehyde
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  • 148
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    Journal für Praktische Chemie/Chemiker-Zeitung 326 (1984), S. 849-852 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Cyanoethylation of HydroquinazolinonesBy the reaction of acrylonitrile with octahydroquinazolinone-spirocyclohexane (1), cyanoethyl-octahydroquinazolinone-spirocyclohexane (2) is formed. Compound 2 and hydrogen-peroxide yield 5a-cyanoethyl-5-oxo-perhydro-oxaziridino[3,2-j]-quinazolin-2-spirocyclohexane (5). 2-Phenyl-octahydroquinazolinone (7) and acrylonitrile form 3,5a-biscyanoethyl-2-phenyl-octahydroquinazolinone-(4) (8). Compound 8 and hydrogenperoxide yield 3-phenyl-4,5a-biscyanoethyl-4-oxoperhydro-oxaziridino[3,2-j]-quinazoline (9). Compound 9 rearranges with ferrous sulphate to 3,4a-bis-cyanoethyl-4-oxo-8a-hydroxy-2-phenyl-octahydro-quinazoline (10).
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  • 149
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    Journal für Praktische Chemie/Chemiker-Zeitung 326 (1984), S. 876-892 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: About the Photochromic and Thermochromic Effect of Benzil PhenylhydrazonesBenzil phenylhydrazone 1 synthesized from benzil and phenylhydrazine possesses s-trans-E configuration detected by means of quantum chemical calculations and its spectral data. Upon irradiation a photochromic process proceeds with a λ-shift Δ λ ≈ 80 nm. The photoproduct has an s-cis-Z configuration. The quantum yields of the EZ-isomerization measured by spectroscopic methods depend on solvent (ΦEZ= 0,077 in CH3OH, ΦEZ= 0,22 in n-hexane), but are independent of the excitation wavelengths and O2. Benzil N-methylphenylhydrazone 2 is inactive under stationary irradiation. Both the Z/E-isomerization of 1 and 2 are be sensitized by benzil and m-methoxyacetophenone. On the basis of kinetic measurements the quantum yields of sensitized reactions of 1 are calculated (ΦEZsens = 0,43; ΦZEsens = 0,57). In protic solvents benzil phenylhydrazone 1 has thermochromic properties caused by E/Z-isomerizations. The measured activation parameters of these reactions are small. It is assumed that both the photoinduced and thermal isomerizations proceed via azo intermediates, as indicated by flash photolysis experiments.
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  • 150
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    Journal für Praktische Chemie/Chemiker-Zeitung 326 (1984), S. 899-909 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Photooxidation of Leuco Dyes. VIII. Time Resolved Investigations of the Mechanism of the Photooxidation of Leucocrystal VioletThe photooxidation of leucocrystal violet has been reexamined by means of conventional and laser flash photolysis as well as spin trap experiments. Three radical transients have been observed and assigned to the cation radical (λmax ≈ 490, 530 nm), the neutral radical with one—NCH3—CH2 moiety (λmax ≈ 480 nm) and the triphenyl methyl radical derivative (λmax ≈ 400 nm).
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  • 151
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  • 152
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    Journal für Praktische Chemie/Chemiker-Zeitung 326 (1984), S. 360-366 
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    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Preparation of β-Substituted trans-Ethylene Diphenylphosphines and Sulphides by P(0) and P(S)-activated OlefinationMethylene bis-diphenylphosphine monoxide (3c) in tuluene reacts regiospecifically and stereoselectively with aldehydes in the presence of potassium tert-butoxide to ß-substituted transethylene diphenylphosphines 6, which can be oxidized to the sulphides 2 by sulphur in acetone. These sulphides 2 are to be obtained also directly from methylene bis-diphenylphosphine oxide sulphide 3b and methylene bis-diphenylphosphine disulphide 3d, respectively, under the same olefination conditions. But the yields are smaller and the purification of the raw products is much more difficult, if 3d is used.
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  • 153
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    Journal für Praktische Chemie/Chemiker-Zeitung 326 (1984), S. 599-604 
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    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The present work deals with the synthesis of 6-aryl-2-ethoxycarbonyl pyridazin-3(2H)-ones (2) as useful synthetic intermediates because they allow formation of a new hydrazides (3), hydrazidoyl chlorides (4) and the highly reactive nitrile imine species (5). Dimerization and reaction of the latter species with benzonitrile, benzaldehyde and their p-methoxy and p-nitro derivatives provides a convenient method for the synthesis of substituted 1, 2, 4, 5-tetrazines (6), 1, 2, 4-triazoles (7) and 1, 3, 4-oxadiazoles (8), respectively, with pyridazin-3(2H)-one moiety.
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  • 154
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    Journal für Praktische Chemie/Chemiker-Zeitung 326 (1984), S. 737-746 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Cyanic Acid Esters. 35. On Formation and Consecutive Reactions of N-Cyanato Phthalimide. New Specifically Activated and Blocked Isatoic Acid DerivativesDepending on the reaction conditions N-hydroxy-phthalimide affords on treatment with cyanogen bromide via N-cyanato phthalimide 2 the iminocarbonate 3 and isatoic acid derivatives 7 and 16. Both the latter react with nucleophiles as isatoic acid derivatives activated on the carboxylic group and protected on the carbamic group or vice versa, furnishing N,N-bis alkoxycarbonyl anthranilic acid amides 9, N-alkoxycarbonyl anthranilic acid amides 12, o-alkoxycarbonyl phenyl ureas 17 and the benzotriazepin-2,5-dione 14. The structures of the new compounds are proved by 1H-n.m.r. and 13C-n.m.r. measurements as well as independent synthesis.
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  • 155
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    Topics: Chemistry and Pharmacology
    Notes: Deactivation Behaviour of Arenes and Heteroarenes. XLI. Structural and Environmental Effects on the Intramolecular [π4s + π4s]- Photocycloaddition Reaction of α, ω-Bis-(9-acridiziniumyl) - alkanes.Fluorescence characteristics, including quantum yields and decay times, and quantum efficiencies for the reversible intramolecular [π4s + π4s]- photocycloaddition reaction for a series of α, ω-bis-(9-acridiziniumyl)-alkanes have been measured in several solvents and they have been compared with those of the model compounds acridizinium-ion. and 9-methyl-acridizinium-ion. These parameters of the bichromophores depend on the number of CH2-groups of chromophor linkage. The title compounds investigated were divided into groups of common behaviour, and differences are due to increasing bond angle strain and coulomb-repulsion in the photocyclomer state.
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  • 156
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    Journal für Praktische Chemie/Chemiker-Zeitung 326 (1984), S. 779-790 
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    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: On the Catalytic Dimerization of Acrylic Acid Derivatives by Palladium Complexes. IV. The Dimerization of Methyl Methacrylate.Methyl methacrylate has been dimerized to a mixture of 2.5-di(methoxycarbonyl)-hex-1-ene(1) and (E)-2.5-di(methoxycarbonyl)-hex-2-ene (2) by catalytic systems containing dichlorobis (nitrile)-palladium (II) complexes and silver tetrafluoroborate, Codimerization experiments with methyl acrylate show a lower reactivity of methyl methacrylate. Oxidative addition of ß-chloro methyl methacrylate to tetrakis (triphenylphosphine) palladium (O) gave ß-polladio methyl methacrylates (8, 9) suitable for model investigations of the catalytic reaction. A proposal is given for a mechanism via pd(IV) intermediates.
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  • 157
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    Journal für Praktische Chemie/Chemiker-Zeitung 326 (1984), S. 811-816 
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    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 7 Tab.
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    Journal für Praktische Chemie/Chemiker-Zeitung 326 (1984), S. 804-810 
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    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Mass Spectrometric Fragmentation of 4-Substituted 5-Hydroxynaphth[2,1-d]1,3-oxathiol-2-onesThe mass spectra of 5-hydroxynaphth[2,1-d]1,3-oxathiol-2-ones 1a-1x have been studied. They show characteristic fragmentations with participation of neighbouring groups. Investigations of isotopically labelled 4-alkyl and 4-acyl derivatives give evidence for the formation of cyclic ionic structures.
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  • 159
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    Journal für Praktische Chemie/Chemiker-Zeitung 326 (1984), S. 823-828 
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    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The Dependence of UV-Spectra of Substituted Naphthalenesulfonic Acids upon the pH-Value - A Contribution in Order to Elucidate the Structure of Acid Azo Dyes
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  • 160
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    Journal für Praktische Chemie/Chemiker-Zeitung 326 (1984), S. 910-916 
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    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A detailed kinetic analysis is presented of the transient sultone (A2) formation which proceeds thermally from a photogenerated intermediate species after flash excitation of bromo thymol blue and bromo xylenol blue in the presence of quinoline, pyridine and 4-methyl pyridine in toluene solution. The sultone ring cleavage is a bimolecular reaction with the base resulting in a hydrogen-bridged molecular complex (A1) which equilibrates consecutively with the most stable rotamer of the ion pair (A3). The rate constants for the latter reaction are controlled essentially by conformational changes rather than by the proper proton transfer.
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  • 161
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    Journal für Praktische Chemie/Chemiker-Zeitung 326 (1984), S. 924-934 
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    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Diels-Alder-Reactions. IX. On the Formation and the Thermolysis of Isomeric TricyclopentadienesThe formation of isomeric tricyclopentadienes by codimerisation of cyclopentadiene with endo- and exo-dicyclopentadiene between 100 and 140°C in the liquid phase, and the retrodiene reaction of the main isomeres of the tricyclopentadiene fraction by gas phase thermolysis were studied kinetically between 230 and 310°C. The rate constants and the parameters of activation were determined.
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    Journal für Praktische Chemie/Chemiker-Zeitung 326 (1984), S. 941-946 
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    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: 10β;-Chloro-estra-1,4-dienes as Intermediates of the Introduction of a 9(11)-Double Bond in Estra-1,3,5(10)-trienesThe synthesis of 9(11)-didehydro-estra-1,3,5(10)-trienes 5 starting from estra-1,3,5(10)-trienes 1 is described. 1 can be transformed into the ketals 2 and 3 by means of isocyanuric acid chloride and an alcohol such as methanol or ethylene glycol in the absence of moisture.The ketals 2 and 3 are sensitive against hydrolysis and react in the presence of water and traces of acid under formation of chlorodienone 4. Dehydrochlorination of 2, 3 and 4 with potassium-tert.-butylate in dimethylsulfoxide gives the 9(11)-didehydro compounds 5. The reaction mechanism of the electrophilic addition of positive chlorine and alcohol to the aromatic A-ring of 1 is discussed.
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    Journal für Praktische Chemie/Chemiker-Zeitung 326 (1984), S. 955-961 
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    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Pyrylium Compounds. XXV. Quantum Chemical Calculations Concerning the Valence Isomerization of 2-Amino-2H-pyran and -thiopyranThe equilibrium 2-amino-2H-pyran 6 ⇌ 5-amino-2,4-dien-1-one 7 was investigated using the semi-empirical MINDO/3 and MNDO methods. In accordance with experimental findings for the substituted derivatives 1/2a-d, the introduction of a methyl group into the position 3 of 6 or the exchange of oxygen by sulfur shifts the equilibrium towards the cyclic structures 8 and 10, respectively. Polar solvents, the influence of which was estimated applying the reaction field approach as well as the solvaton theory, and entropy effects are calculated to favour the ring-open valence isomer 7. These results also correspond to experimental results.
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  • 164
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    Notes: Photocatalytical Systems. LXIV. Theoretical Investigations of the Charge Transfer and of the Photochemical Reactivity of d6 Transition Metal Complexes with π Acceptor LigandsQuantum chemical investigations concerning the charge transfer interactions between a d6 complex fragment and heterocyclic nitrogen ligands are reported. The influence of inductive, mesomeric and steric effects on the π acceptor ability of the isolated ligand and on the electronic structure of the pentacyano-ferrate(II) mixed ligand compounds has been investigated and possibilities to sensitize spectrally the Fe(CN)5L3- system (L= pyridine-type ligand) with regard to their photochemical reactivity are discussed.
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  • 165
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    Notes: Investigations of the Photo-Fading of Tautomeric Azo Dyes. VI. The Photochemical Oxidation by Singlet Oxygen of Phenylazoacetylacetones and PhenylazopyrazolonesThe dye-sensitized photo-oxidation by singlet oxygen of phenylazoacetylacetones (1) and Phenylazopyrazolones (2) has been investigated. The photo-fading of dyes is accelerated in the presence of Methylene Blue, a sensitizer of singlet oxygen, in airsatured methanolAn excellent relationship exists between the fading-rate of a series of dyes (1) and Hammett-σ-constants. An unexpected trend was found for photo-fading of a series of dyes (2). The Hammett plot consists of two parts, with a negative slope derived from electron-releasing substituents and a positive slope derived from electron-withdrawing substituents. The anomalous photo-fading is due to an attack of singlet oxygen on the more reactive anion of the phenylazopyrazolones in the case of electron-withdrawing substituents. In methanol containing acetic acid the dyes (2) exist only as the hydrazone tautomers. Under these conditions the fading-rate show a linear relationship with σ-constants.
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    Journal für Praktische Chemie/Chemiker-Zeitung 326 (1984), S. 994-998 
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    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 3 Tab.
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    Journal für Praktische Chemie/Chemiker-Zeitung 326 (1984), S. 1008-1010 
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    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 2 Tab.
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    Journal für Praktische Chemie/Chemiker-Zeitung 326 (1984), S. 1016-1020 
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    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Prostaglandins and Prostaglandin Intermediates. XI. Synthesis of Optically Active Bicyclic Lactones - Convenient Intermediates for 8-Methyl Prostaglandins
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    Journal für Praktische Chemie/Chemiker-Zeitung 326 (1984), S. 1027-1033 
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    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Quinazoline Carboxylic Acids. III. Quinazolin-4-on-3-benzoic Acids and Esters
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    Journal für Praktische Chemie/Chemiker-Zeitung 326 (1984), S. 1034-1036 
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    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Fluorescence Properties of Polymethine Dyes with Bridged Chains
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    Journal für Praktische Chemie/Chemiker-Zeitung 326 (1984) 
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    Keywords: Chemistry ; Organic Chemistry
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    Journal für Praktische Chemie/Chemiker-Zeitung 326 (1984), S. 1-11 
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    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Complex Catalysis. XV. Cationic η3-Allyl-bis(triorganylphosphite)nickel(II) Complexes as Catalysts for the Stereoregular Butadiene PolymerisationSynthesis and catalytic properties of [C3H5NiL2]PF6 complexes 1a-f with L = tri-ethyl-, -isopropyl-, -phenyl-, -o-tolyl-, -thymyl- and o-biphenylylphosphite are described. It is shown how electronic and steric effects of the phosphite ligands in these complexes control their catalytic activity and selectivity in 1,4-polymerization of butadiene.
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    Journal für Praktische Chemie/Chemiker-Zeitung 326 (1984), S. 12-22 
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    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Polyfunctionalized N-Tensides. VII. Substitution and Elimination in the Reaction of 1,2-Dihalogenoalkanes with Amines1, 2-Dichloroalkanes, 1, 2-dibromoalkanes and mixtures of 1-bromo-2-chloroalkanes and 1-chloro-2-bromoalkanes react with primary or secondary amines and give both elimination and substitution products, often in a nearly 1:1 proportion.The elimination products are the cis and trans-1-halo-1-alkenes, the 2-halo-1-alkenes, the 1,3-and 2, 4-dienes and the 1-alkenes. The main substitution products are the 1, 2-bis-aminoalkanes. Physical dates, 1H-n.m.r.-spectra, surface tension values and CMC-dates are given.
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    Journal für Praktische Chemie/Chemiker-Zeitung 326 (1984), S. 23-28 
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    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Kinetik der Dimerisierung von Aminen durch Wasserstoffperoxid in Gegenwart von Fe(II)SO4 als KatalysatorDie Kinetik der Dimerisierung von Diethyl, n-Butyl- und tert.-Butylamin durch Wasserstoffperoxid in Gegenwart von Fe(II)-Ionen wurde untersucht. Die Reaktion ist bezüglich Fe(II)-Ionen und der Amine 1. Ordnung und 0. Ordnung betreffs Wasserstoffperoxid. Produkte der Dimerisierungsreaktionen sowie einige ihrer kristallinen Derivate wurden erhalten und identifiziert. Die Aktivierungsenergien für Diethyl-, n-Butyl- und tert.-Butylamin betragen 153, 130 bzw. 105 KJ mol-1. Ein Reaktionsmechanismus wurde aufgrund der experimentellen Beobachtungen vorgeschlagen.
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    Journal für Praktische Chemie/Chemiker-Zeitung 326 (1984), S. 29-34 
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    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Configurational Assignment of Steroids with Primary and Secondary Amino Groups by CD Measurements of the Copper Succinimidate complexesThe CD spectra of the copper succinimidate complexes of 9 different steroids with a primary and 3 steroids with a secondary amino group were investigated. A good correlation between the sign of the Cotton effects in visible range and the chirality of the immediate neighbourhood of the nitrogen atom was observed. The results obey the earlier established octant rule for this chromophor.
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    Journal für Praktische Chemie/Chemiker-Zeitung 326 (1984), S. 35-40 
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    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Thermitase - A Thermostable Serine Protease. I. Synthesis of Alanine Peptide Esters as Substrates of the EnzymeThe synthesis of N-acetylated and N-succinylated peptide esters of alanine is described. The peptides are built up from the Z-Abkürzung: Z = Benzyloxycarbonyl, Ac = Acetyl, Suc = Succinyl, OMe = Methylester, MA = Mischanhydridmethode, E = Ether, PE = Petrolether, Etac = Ethylacetat, AcOH = Essigsäure, Dibu = n-Dibutylether, DMSO = Dimethylsulfoxid, DMF = Dimethylformamid, TEA = Triethylamin, Ac2O = Essigsäureanhydrid protected peptides by liquid phase fragment condensation and by acylation of the deprotected peptide esters. The kinetic parameters K m and K cat of some compounds are presented.
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  • 178
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    Journal für Praktische Chemie/Chemiker-Zeitung 326 (1984), S. 41-47 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Thermitase - A Thermostable Serine Protease. II. Synthesis of Substrate Analogous Peptide Chloromethyl Ketones as Irreversibly Acting InhibitorsThe preparation of dipeptide to pentapeptide chloromethyl ketones of alanine wth variation of the amino acid in the P1 and P2 positionNomenklatur für die individuellen Aminosäurereste der Peptide nach I. Schechter u. A. C. Berger, Biochem. Biophys. Res. Commun. 27, 157 (1967). of the peptides is described. The synthesis is performed by fragment condensation of N-acylated amino acids or peptides with the unprotected chloromethyl ketone derivatives of amino acids and peptides, respectively. Some examples of enzyme inactivation by peptide chloromethyl ketones are discussed.
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  • 179
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    Journal für Praktische Chemie/Chemiker-Zeitung 326 (1984), S. 54-62 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: 13C-N.M.R. Investigation of Interannular Conjugation in Substituted PyrazolesThe correlation of the 13C-chemical shifts with the Hammet values for substituted 3-anilino-1, 5-diphenylpyrazoles (1a-k) and substituted 3-methyl-1, 5-diphenylpyrazoles (2a-g) provides evidence for extensive interannular conjugation only between the N-benzene-and the pyrazole rings, whereas in the capto-dative disubstituted system 1 extensive conjugation through the whole molecule is possible. The chemical shifts correlate well with the HMO-calculated π-electron densities. From a comparison of the chemical shifts of unsubstituted 1 and diphenylamine it can be concluded that the 1,5 -diphenylpyrazol-3-yl group has the same electronic effect as the phenyl group.
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  • 180
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    Journal für Praktische Chemie/Chemiker-Zeitung 326 (1984), S. 48-53 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Thermitase - A Thermostable Serine Protease. III. Synthesis of N-Acylated Peptide Methyl Ketones as Inhibitors Reversibly Bound to the EnzymeMethyl ketone derivatives of dipeptides to pentapeptides are used as suitable tools in the investigation of the non-covalent binding for subsite mapping of the active site of the enzyme. The synthesis is mainly performed by fragment condensation of N-acylated peptides or amino acids with methyl ketone derivatives of amino acids. These are prepared from the Z-protectedAbkürzungen: Ac = Acetyl, Z = Benzyloxycarbonyl, Boc = t-Butyloxycarbonyl, Suc = Succinyl, Glp = Pyroglutamyl, OBz = Benzylester, pNA = p-Nitranilid, CH3 = Methylketon, CH2Cl = Chlormethylketon, MA = Mischanhydridmethode, TEA = Triethylamin, NEM = N-Ethylmorpholin, CKEE = Chlorkohlensäureethylester, CKBE = Chlorkohlensäurebutylester, MeOH = Methanol, EtOH = Ethanol, AcOH = Essigsäure, Ac2O = Acetanhydrid, Etac = Ethylacetat, THF = Tetrahydrofuran, E = Ether, PE = Petrolether, DMF = Dimethylformamid, DMSO = Dimethylsulfoxid, DMAP = 4-(Dimethylamino)-pyridin cloromethyl ketones by catalytic hydrogenation. For the coupling steps the Z-protection is preferred. The peptide methyl ketones used in kinetic studies were N-protected by the Z, acetyl, Boc or pyroglutamyl residue.
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  • 181
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    Journal für Praktische Chemie/Chemiker-Zeitung 326 (1984), S. 73-80 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: In the autoxidations of 1-phenylprop-1-yne, 1-phenylbut-1-yne, and 1-phenyl-3-methylbut-1-yne a considerable attack at the C≡C triple bond takes place. Both products of the oxidative cleavage of the C≡C bond and products formed through the corresponding oxirenes were detected. The oxirenes rearrange via the isomeric ketocarbenes to ketenes, which yield the corresponding carboxylic acids or their esters. A part of the intermediate ketenes is oxidized with decarboxylation to lower ketones. All products were identified and quantitatively determined after LiAlH4 reduction to the corresponding alcohols.
    Additional Material: 8 Tab.
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  • 182
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    Journal für Praktische Chemie/Chemiker-Zeitung 326 (1984), S. 63-72 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Solvatochromism of 4′-Dialkylamino-α-Cyano-Stilbene-4-Diazonium-Salts4′-Dialkylamino-stilbene-4-diazonium-salts are deep coloured compounds and give strong solvatochromism. 4′-Diethylamino-α-cyano-stilbene-4-diazonium-tetrafluoroborate was investigated in 52 different solvents and 3 binary solvent mixtures. With increasing solvent basicity the longest wave lenght absorption maximum (\documentclass{article}\pagestyle{empty}\begin{document}$ \nu^{\hspace{-5pt}\sim}_{\rm max} $\end{document}) decrease. Complex formation by crown ethers causes a decrease of \documentclass{article}\pagestyle{empty}\begin{document}$ \nu^{\hspace{-5pt}\sim}_{\rm max}$\end{document}, too. In solvents with dielectricity constants higher than about 15 dissociation effects superpose solvatochromism. The summary of experimental dates support the approach of specific nucleophilic solvatation of diazonium ions.
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  • 183
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    Journal für Praktische Chemie/Chemiker-Zeitung 326 (1984), S. 81-86 
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    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Ionization and Dissociation of Triphenylmethyl Halides in MethylendichlorideThe Winstein scheme is valid for triphenylmethyl halides in methylendichloride. The equilibrium of ionization and dissociaton has been determined by investigation of the ratio between the sum of concentrations of ionic species and the covalent form. Tritylbromide in methylendichloride shows an exothermic ionization but endothermic dissociation. In the case of tritylchloride ionization and dissociation are nearly independent on the temperature.
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  • 184
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    Journal für Praktische Chemie/Chemiker-Zeitung 326 (1984), S. 87-91 
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    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Influence of Styren Addition on the Ionization-Dissociation Equilibrium of Trityl Halides in Methylene DichlorideThe ionization-dissociation equilibrium in solutions of trityl halides in methylene dichloride is effected by the addition of π-donors as a function of the temperature. The intensity of the trityl absorption of trityl fluoride and trityl chloride is decreased as it can be shown by u.v.-spectroscopy. The trityl absorption of trityl bromide solutions in methylene dichloride is very sensitive towards temperature changes. Measurements of the equilibrium constants for the ionization - dissociation-equilibrium, when styrene is added to the solution, indicate a specific solvation effect by the styrene molecules, however, a stabilization of ion pairs by specific solvation due to styrene molecules does not occur.
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  • 185
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    Journal für Praktische Chemie/Chemiker-Zeitung 326 (1984), S. 101-110 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A New Synthesis of 6H-1,3-ThiazinesA new method for the synthesis of 1,3-thiazines is described. The addition of nucleophiles to γ-isothiocyanatoallylchlorides (1a-j) leads to functionalisation and subsequent cyclisation (nucleophilic cyclofunctionalisation). Reaction of secondary amines or alcohols under catalysis by tert. amines gives numerous 2-dialkylamino- (3a-w) or 2-alkoxy-6H-1,3-thiazines (4a-p).
    Additional Material: 4 Tab.
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  • 186
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    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Photoinduced Electron Transfer-Reactions of Arenediazonium Ions Complexed with Crown EthersThe photolysis (full light of a medium pressure Hg-lamp) of p-methylbenzenediazonium-tetrafluoroborate in the presence of the crown ether 18-crown-6 (1) yields mainly the products of a heterolytic dediazoniation via arene cations as intermediates. The quantum yield ϕges of the photolysis from p-methoxybenzenediazonium-tetrafluoroborat in CH2Cl2 decreases in the presence of 18- crowns-6 (1) from 0.66 to 0.08. In contrast to 1, the photolysis of arenediazonium salts in the presence of dibenzo-18-crown-6 (3) yields mainly the products of a homolytic dediazoniation as a consequence of an electron transfer from 3 to the diazonium ion. ϕges of this reaction increases with decreasing wavelength of the exciting light from 0.09 (436 nm) to 0.32 (366 nm). this wavelength dependence is explained by formation of a correlated radical pair after excitation. In agreement with this situation a photo-CIDNP-effect is observed in the 15N-n.m.r.-spectra of isotopically labeled arenediazonium salts complexed by 3 and benzo-18-crown-6(2). No photo-CIDNP-effect is observed in the presence of 1. This different behaviour of the EDA-complexes formed by arenediazonium salts with the two different groups of crown ethers 1 and 2, 3 is discussed as a control of the electron transfer-reaction by the structure of the frontier orbitals.
    Additional Material: 3 Ill.
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  • 187
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    Journal für Praktische Chemie/Chemiker-Zeitung 326 (1984), S. 121-128 
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    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Dicyclopentadiene Oxidation. IV. Oxidation of 4,5- and 8,9-Dihydro-dicyclopentadieneA mixture of exo- and endo-4,5-dihydro-dicyclopentadiene 5 and also pure endo-8,9-dihydro-dicyclopentadiene 7 and pure exo-dicyclopentadiene 10 was oxidized in the absence and in the presence of catalysts. The compounds containing the norbornene structure mainly gave the corresponding exo-epoxides. No catalytic effects were observed in the formation of these nor-bornene epoxides. Compound 7 containing only the cyclopentene structure mainly yielded the corresponding hydroperoxide 9. In this case a catalytic effect of epoxidation catalysts was observed: in the presence of such catalysts the epoxide was increased.The results obtained prove the mechanism of dicyclopentadiene oxidation proposed by us.
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  • 188
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    Journal für Praktische Chemie/Chemiker-Zeitung 326 (1984), S. 129-138 
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    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Acylation of Heterocycles with Carbonic Acid Derivatives. IV. Reaction of Benzoxazolin-2-thione with Aryl Cyanates. Kinetics and MechanismThe arylcyanate benzoxazoline-2-thione (1) reaction in the presence and absence of the tertiary amines yields 1-aryloxyiminocarbonylbenzoxazoline-2-thione (2) and 2-thiocyanatobenzoxazole (4). A mechanism is proposed based on the influences of the reactants concentration, the concentration and basicity of tertiary amines, the solvent-water concentration, the arylcyanate substituents electronic effects on the reaction rate and the apparent activation parameters. This mechanism consists in the nucleophilic attack of the benzoxazoline-2-thione S-atom on the cyanate, followed by rearrangement through a four-center transition state.
    Additional Material: 8 Tab.
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  • 189
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    Journal für Praktische Chemie/Chemiker-Zeitung 326 (1984), S. 145-147 
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    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: INDO Calculation of 15N-13C Coupling Constants in Simple Cyanines and Merocyanines
    Additional Material: 1 Ill.
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  • 190
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    Journal für Praktische Chemie/Chemiker-Zeitung 326 (1984), S. 139-144 
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    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Quantum-Chemical Calculations on Allyl-Type Radicals: Cycloalkenyl- and Cycloalk-1-enylmethyl RadicalsThe ability of the MINDO/3-HE-method for predicting various molecular properties was tested for cycloalkenyl- (1 to 4), cycloalk-1-enylmethyl-(5 to 8), and for the resonance-stabilized cyclic radicals (9 to 12). Close by it was established that the calculated heats of formation are largely correct. The electronic distribution in the allylic part of 1 to 12 is evidently too levelled.Based on the defination of allyl resonance energy (ARE - SZWARC (1948)) a mean value for the ARE of 1 to 8 is derived to 55 ± 12 kJ · mol-1.
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  • 191
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    Journal für Praktische Chemie/Chemiker-Zeitung 326 (1984), S. 222-232 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Carbon-13 Nuclear Magnetic Resonance Spectra of PhenylfulgidesThe carbon-13 chemical shifts are determined in a series of phenylfulgides in order to investigate steric and electronic influences of substituents. By means of the shift differences between suitably substituted compounds results can be obtained as to the relative variation of the rotation angles of the phenyl rings as well as to te angle alterations between the exocyclic double bonds and the anhydride ring. Introducing 4-CH3O- and 4-NO2-groups at the phenyl rings the substituent induced alterations of the carbon-13 chemical shifts and the π-polarization effects related with it are discussed.
    Additional Material: 3 Ill.
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  • 192
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    Journal für Praktische Chemie/Chemiker-Zeitung 326 (1984), S. 233-247 
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    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Electronic and Steric Substituent Influences on the U.V./VIS-Absorption Spectra of Phenylfulgide IsomersThe u.v./vis spectral data of a large number of phenylfulgides (E-, Z-, E-E-, E-Z-, Z-E-, Z-Z-isomers, 1.8a-dihydronaphthalenes) are presented. An increase of the number of phenyl rings as well as substitution of the phenyl rings cause correlatable bathochromic spectral shifts. Steric influences became obvious by introducing methyl groups, by coplanarization of phenyl groups and in the series of isomers. By means of PPP calculations shifts in position and/or intensity of absorption bands are ascribed to the substituent effects.The calculated band polarization of E(E-E)-isomers are in agreement with the results of polarization spectra in oriented liquid crystal mesophases. The polarization spectra allow the assignment of the longwave absorption band to the S2 ← S0 and S1 ← S0 electronic transitions for E-E-Isomers with a C2v-symmetry.
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  • 193
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    Journal für Praktische Chemie/Chemiker-Zeitung 326 (1984), S. 248-252 
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    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: α-Cyanochalcone reacted with thiourea and guanidine to yield the corresponding pyrimidine derivatives 2 and 4. On the other hand, urea reacted with the same reagent under the same experimental conditions to yield the known urea derivatives 3. A new synthesis of polyfunction pyridine via reaction of 1a with malononitrile in presence of aniline could be developed. Similar to the behaviour of 1a, Compounds 1b, c reacted with malononitrile in presence of aniline to yield compounds 8 and 9. In contrast to the behaviour of compounds 1a-c, 1d reacted with malononitrile to yield the malononitrile derivatives 10 or 11 based on the reaction conditions. Mechanisms to account for formation of the reaction products were suggested.
    Additional Material: 2 Tab.
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  • 194
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    Journal für Praktische Chemie/Chemiker-Zeitung 326 (1984), S. 253-258 
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    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Gibberellins. CIII. Synthesis of 8-Amino-gibbanesFor investigations of the structure-activity relationships of gibberellin phytohormones the synthesis of 8-amino-gibbanes is described. The reaction pathway involves condensation of gibberellin C (1a) and its methylester 1b with primary amines to the corresponding azomethins 1c-11 followed by stereoselective NaBH4-reduction to 8α-amino gibbanes 2a-2r.
    Additional Material: 1 Ill.
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  • 195
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    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Studies on U.V./Vis Absorption Spectra of Azo Dyes. XI. General Relationships between Structure and Colour of Protonated Azo DyesThe U.V.-VIS spectra of a wide range of azo dyes having structural variations in both diazo and coupling components in acidic solution are discussed.The azonium cation can be regarded as a donor-acceptor chromophore. Thus, structural variations which give a bathochromic shift in λmax, are explained. The negative halochromism is also discussed with reference to this model.
    Additional Material: 1 Ill.
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  • 196
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    Journal für Praktische Chemie/Chemiker-Zeitung 326 (1984), S. 287-302 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Pyrylium Compounds. XXI. Structure and Tautomerism of Pseudobases of Unsymmetrically Substituted 2,4,6-Triarylpyrylium SaltsHydrolytic ring opening of unsymmetrically substituted 2,4,6-triarylpyrylium salts 11 results in a mixture of two tautomeric pseudobases, the penten-1,5-diones 13 and 14. In crystalline state as a rule one of these tautomers markedly predominates, whereas in solution a rapid equilibrium establishment occurs which can be followed by 1H-n.m.r. and u.v. spectroscopy (equilibrium ratio nearly 1:1). The 1H-n.m.r. spectroscopic structural assignment of the two isomeric forms was supported by u.v. spectroscopic studies using 1:1 mixtures of the chromophoric partial systems ArCOCH=CHPh and ArCOMe or the pseudobases 10 of symmetrically substituted 2,4,6-triarylpyrylium salts 9 as reference systems. From the mass spectra of the pseudobases 10 and 13/14 follows that - if hydrolysis of 11 is performed in media containing H218O - mass spectrometric isotopic analysis of the resulting 18O-labelled pseudobases allows no information to be made about the regioselectivity of the ring opening. - Novel starting pyrylium salts of type 9 and 11 are characterized by u.v./vis data and by transformation into the corresponding pyridine derivatives.
    Additional Material: 2 Ill.
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  • 197
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    Topics: Chemistry and Pharmacology
    Notes: 2, 2-Disubstituted Cyclopentane-1, 3-diones. IV. Synthesis of Prochiral Intermediates for the Synthesis of 8-Methyl-prostaglandin C2 by Alkylation of 2-Methyl-cyclopentane-1, 3-dione with 1-Bromo-alk-2-ynes.2-Methyl-cyclopentane-1, 3-dione (1) is preferentially C-alkylated by 1-bromo-alk-2-ynes in aqueous sodium hydroxide solution. By this method it is possible to prepare 2,2-disubstituted-1, 3-diones (3-8), which can be converted into prochiral intermediates for 8-methyl-PGC2, containing the complete carboxylic side chain.
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  • 198
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    Journal für Praktische Chemie/Chemiker-Zeitung 326 (1984), S. 457-466 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Synthesis and Properties of Liquid Crystalline Derivatives of RhodanineSubstituted benzylidene-rhodanines 3-8 were prepared both by condensation of 1 a-f with suitable aldehydes and by acylation of 2a-g with substituted benzoyl chlorides or cinnamoyl chlorid. The mesomorphic properties of the compounds are discussed in respect to molecular structure with the aid of i.r.-, Raman- and u.v./vis-spectra of 3d, 3k, 4, 5, 6g, 8a. We have investigated the dielectric and electrooptic behaviour of 31.
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  • 199
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    Journal für Praktische Chemie/Chemiker-Zeitung 326 (1984), S. 515-518 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 3 Ill.
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  • 200
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    Journal für Praktische Chemie/Chemiker-Zeitung 326 (1984), S. 524-528 
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    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Two Modified Pulse Sequences for the 13C NMR Spectroscopic Characterization of CHn Building Groups. An Effective Method for the Determination of n and for the Estimation of 1J(13C—1H)
    Additional Material: 3 Ill.
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