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991.
Theodore A. Henderson Robert W. Rhoades Carol A. Bennett-Clarke Pat A. Osborne Eugene M. Johnson Mark F. Jacquin 《The Journal of comparative neurology》1993,336(2):243-260
Prior studies indicate that neonatal nerve injury kills many trigeminal (V) first- and second-order cells, and interrupts pattern formation in the brainstem and cerebral cortex. Yet it is not known whether effects upon cell survival and pattern formation are causally related. To determine whether axotomized V ganglion cells can be rescued by an exogenous trophic agent, rats received 5 mg/kg of nerve growth factor (NGF) prior to, and every day after, infraorbital nerve section on the day of birth until sacrifice on postnatal day (PND) 1, 3, 5, 7, or 14. Other animals received identical lesions without NGF. Ganglion cell numbers were significantly reduced by PNDl in pups not given NGF, while NGF-treated rats displayed no significant cell loss through PND7. However, NGF did not permanently rescue V neurons because ganglion cell numbers were reliably reduced by PND14. Cell numbers in V nucleus principalis were reduced by PNDl in pups not given NGF, while NGF-treated animals displayed no cell loss through PND14. NGF's rescue of second-order cells is probably an indirect effect of NGF actions upon V ganglion cells because, in other newborns, NGF failed to maintain principalis cells after direct lesion of the left V ganglion. To determine whether preventing cell death permits whisker-related pattern formation, other rats also received NGF prior to and after infraorbital nerve section at birth. After 3–14 days, patterns were assessed in the brainstem and cortex with cytochrome oxidase histochemistry and serotonin immunocytochemistry. Whisker-related patterns failed to develop as in cases not given NGF. These data indicate that communication with the periphery is necessary for the maintenance of central whisker-related patterns. They also suggest that V ganglion cells can be rescued, albeit temporarily, from rapid injury-induced death by NGF, thereby delaying injury-induced cell death in nucleus principalis. However, the mechanism(s) responsible for injury-induced pattern alterations in the developing V system remains to be elucidated. © 1993 Wiley-Liss, Inc. 相似文献
992.
Hidemi Kaname Toshio Yoshihara Yuji Yaku Tetsuo Ishii 《Medical Electron Microscopy》1993,26(2):99-104
Primary squamous cell carcinoma of the submandibular gland is a rare tumor. In this report, the histological and ultrastructural
features of a case of primary squamous cell carcinoma arising in the left submandibular gland is presented. Light microscopically,
the tumor consisted of well differentiated keratinizing squamous cell nests. Ultrastructurally, the tumor cells were oval
or spindle-shaped, and several tumor cells had intracytoplasmic desmosome-like structures, resembling intercellular desmosomes.
The majority of the tumor cells contained a large number of intermediate filaments (tonofilaments). Intercellular desmosomes
were well developed. No secretory granules were found. These ultrastructural features may enable us to distinguish primary
squamous cell carcinoma from mucoepidermoid carcinoma which is often misdiagnosed as squamous cell carcinoma. 相似文献
993.
Ida-Marie Stender Takafumi Etoh Tetsuya Tsuchida Hidemi Nakagawa H. Randolph Byers Genji Imokawa Yasumasa Ishibashi 《The Journal of dermatology》1993,20(10):611-617
The ability of the human amelanotic melanoma cell line MM-RU to produce experimental metastases and to grow tumors at subcutaneous inoculation sites in 4-week-old nude mice was examined. After i.v. inoculation of 106 cells, all injected mice (n=21) developed consistent numbers of metastatic pulmonary colonies within 32 days. The coefficients of variation for the number of colonies were between 17%–23% in three independent experiments. Survival time after i.v. inoculation was 63 ± 7 days (mean ± SD) (n=20). Within 20 days, subcutaneous inoculation of 5 × 106 cells resulted in tumor growths of 13 ± 3 mm (mean ± SD) at the inoculation sites in all nude mice (n=12). The MM-RU cell line seems to be a simple, fast vehicle for testing the effect of melanoma growth modulators on experimental pulmonary metastases as well as on subcutaneously growing melanoma. 相似文献
994.
对流行性出血热病毒(EHFV)特异性转移因子(EHFV-TF)的制备、特性及在小鼠体内的活性作用进行了研究。其理化性状与普通 TF 非常相似,能激活淋巴细胞的 E 受体(激活率为65.54%),明显提高 Et-RFC 的形成率。E-HFV-TF 还具有特异性抗原依赖活性:①促进 BALB/C 小鼠和 NIH 裸鼠特异性抗体的产生;②促进 LACA 小鼠脾细胞对 EHFV 反应的特异性应答;③促进脾细胞在 EHVF 存在时对 PHA 诱导下的增殖反应(促时率为151.3%)。EHFV—TF可推迟动物感染 HEFV 后的发病期,延长病程和推迟死亡时间;减轻发病动物脑肺充血、出血、水肿现象和肝肾病理损害程度。结果表明 EHFV-TF 不仅具有提高细胞免疫的非特异活性,而且具有对 EHFV 抗原的依赖活性。本研究提示,E-HFV-TF 可用于 EHFV 感染病人的治疗。 相似文献
995.
996.
Summary The effects of the and anomers of D-glucose on insulin release were studied in a rat model of non-insulin-dependent diabetes, which was induced by streptozotocin injection at 2 days of age. Glucose tolerance of the streptozotocin-treated rats at 8–10 weeks of age was mildly diabetic. Insulin release from the isolated perfused pancreas of the diabetic rats in response to 10 mmol/l -D-glucose was markedly impaired, while insulin response to 10 mmol/l -D-glucose in the diabetic pancreas was only slightly reduced as compared to that in the control pancreas. 相似文献
997.
Summary This study was undertaken to elucidate the clinical and neuropathological effects of copper administration on the macular mutant mouse. Its hemizygote, which is considered to be a model of Menkes kinky hair disease (MKHD), was injected intraperitoneally four times with 10, 20, 20 and 30 g of cupric chloride on days 4, 6, 8 and 10, respectively. The hemizygote's curly whiskers gradually straightened and the frequent tonic seizures and ataxia disappeared after the injections. The body weight also gradually increased. In the cerebral cortex, the dendritic arborization of the pyramidal neurons in both the normal littermate and the treated hemizygote developed with time and reached the maximum around day 60. In the treated hemizygote, however, the arborization of the dendrites was significantly poor in comparison with that in the normal littermate from day 20 to 90. In the cerebellum of the treated hemizygote, the abnormal Purkinje cells with the few somal sprouts, thick stem dendrite and/or poor arborization, which were seen in the non-treated hemizygote, were improved by day 30, while their focal dendritic swellings remained even on day 60. These results indicate that the copper therapy improves not only the clinical manifestations but also the neuropathological changes, especially in the cerebellum.Supported in part by Grant no. 86-05-02 from the National Center of Neurology and Psychiatry of the Ministry of Health and Welfare, Japan 相似文献
998.
Cell production and cell deaths were determined in larval Rana pipiens both in control tecta and in tecta following unilateral eyeball removal in embryos and larvae. Such enucleations produce significantly reduced rates of cell division in the contralateral tecta for virtually the entire larval period (confirming studies with enucleation almost exclusively performed in embryos--Kollros: J. Exp. Zool. 123:153-187, '53, and J. Comp. Neurol. 205:171-178, '82). Significant numbers of cell deaths in all nonependymal tectal cell layers were also observed. Control cell division rates peak at stage X, while cell death peaks are reached in stages XIII-XX. Overall, about 10(6) nonependymal cells are produced in control tecta, and about 350,000 of them die by the end of metamorphosis. Control of cell numbers following enucleation is shown to depend mainly on reductions in cell division rates when the operation occurs early in development and mainly on increases in cell death rates when the operation occurs late in larval life. Such increases in death rates are invariably present within 1 day of the operation whereas the reduced division rates ordinarily require several more days to be seen. The modified rates, both of cell divisions and cell death, are limited to tectal areas to which optic nerve fibers have already extended. Maps of the positions of tectal cell divisions in many larval stages provide the basis for modifying the current dogma that tectal formation occurs as a series of newly formed mediocaudal wedges pushing previously produced wedges rostrolaterad. All such "old" wedges receive substantial cell additions for many stages, with the rate of addition decreasing rostrad earlier than caudad. 相似文献
999.
The cellular composition and in vitro development of glial cultures derived from the rat CNS has been well studied. However, less information is available on similar cultures from other species, particularly higher mammals. To study ovine glial development in vitro, cultures from 50-day fetal to adult animals were characterized with various immunocytochemical markers, which are frequently used to define neural cell subsets in rat cultures. As in rats, both A2B5+ and A2B5- astrocytes can be identified in ovine cultures. However, ovine A2B5+ and A2B5- could not be reliably differentiated by their morphology, which was more influenced by whether the cells were in serum-free or serum-containing media than by their A2B5-positive or -negative status. In addition, ovine A2B5+ astrocytes were present in cultures from early fetal brain before the development of identifiable oligodendrocytes, unlike rat type II astrocytes, which develop only after the appearance of oligodendrocytes. An A2B5+ cell, morphologically similar to the rat 02-A cell, can be found in cultures from fetal ovine cerebrum or cerebellum. A2B5+/glial fibrillary acidic protein (GFAP)- cells in cultures from 100- to 115-day ovine cerebellum appeared to differentiate into A2B5+ astrocytes in serum-containing media. However, in serum-free media, although the A2B5+ cells assumed a more "oligodendroglial-like" morphology, they did not express galactocerebroside or myelin basic protein, suggesting that these cells may not be bipotential as is the rat 02-A cell. Oligodendroglial differentiation was not induced by treatment with dibutyryl cyclic AMP or insulin-like growth factor I. Many cells in cultures from a variety of fetal ages did not label with any of the immunocytochemical markers used, suggesting the need for more cell-type-specific markers to identify neural cell subsets in higher mammals. 相似文献
1000.
Summary A retrospective evaluation of the prognostic value of different parameters available in patients affected by glial tumours and submitted to serial stereotactic biopsy is presented. The series investigated includes thirty-three untreated patients with proven brain gliomas submitted to stereotactic biopsy. All patients have been clinically and neuroradiologically monitored for three years. The factors investigated belong either to the preoperative data (clinical history and symptomatology, CT pattern and volume of the lesion) or to histological and biological data obtained after the stereotactic biopsy. The results suggest the need of a multimodal prognostic evaluation in glial tumours and particularly stressed is the accuracy of prognostic indications derived from cell kinetic studies.Presented at the European Congress of Neurosurgery, Barcelona, September 1987. 相似文献