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Pinealectomy or radical sham pinealectomy were performed on adult golden-mantled ground squirrels,Spermophilus (=Citellus) lateralis, approximately 1 month prior to the date of normal winter emergence. The first hibernatory period and subsequent active season were not different in either of the operated groups from intact animals. However, although the initiation of the second hibernatory period was not affected in the pinealectomized animals, this group failed to show the progressive increase in the length of heterothermic bouts that is characteristic of normal hibernation. Also, terminal arousal occurred approximately 6 weeks earlier in the second year after pinealectomy. Male squirrels showed a corresponding time compression in their annual gonadal cycle, as was assessed by testicular state.These results suggest that the pineal gland of the golden-mantled ground squirrel is involved in the expression of the annual hibernatory cycle. In the absence of the pineal gland the adult of this species is unable to sustain the normal depth and duration of hibernation in the second over-wintering period following pinealectomy.We have carried out additional experiments with young, laboratory-bornS. lateralis and with field-caught, adultS. richardsonii. The results of these studies also are described in this paper.Presented at the Ninth International Congress of Biometeorology, 23 Sept – 1 Oct 1981, Osnabrück and Hohenheim, FRG.  相似文献   
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During an ultrastructural study of small-intestinal mucosa from a patient suffering from alpha-chain disease organisms were identified within the epithelial cytoplasm which showed the fine structural features of the coccidian group. Though coccidiosis is well recognized as causing a diarrhoeal and often lethal illness in animals it has been neglected as a cause of disease in man. Thus this finding may be significant and warrants further investigation into its possible role in the pathogenesis of alpha-chain disease.  相似文献   
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A particulate fraction of adult rat brain (sucrose buoyant density 1.24 gm/ml) catalyzed the incorporation of [3H]dTTP into an acid-insoluble product in an endogenously templated reaction sensitive to ribonuclease pretreatment. Upon fractionation, this activity was identified in the cerebellum, pons, frontal lobes and base. The DNA polymerase present in these brain fractions exhibited a strong preference for the synthetic template dT12–18·poly rA rather than dT12–18·poly dA; dT10 was completely inactive. Purification and equilibrium Cs2SO4 gradient centrifugation of the [3H]DNA product-endogenous template complex suggested that RNA was serving as primer for endogenous DNA synthesis.  相似文献   
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