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991.
Nasopharyngeal carcinoma (NPC) provides a unique opportunity to evaluate distinctive epidemiologic features and a possible etiologic relationship with Epstein-Barr virus (EBV) in human malignancy. The lack of a uniformly accepted pathologic classification for NPC has limited the application of this data, although the World Health Organization (WHO) developed a classification that may solve this problem. Monoclonal keratin antibodies were used for staining of NPC for evaluation of its assistance in diagnosis and classification. In the present immunohistochemical study, monoclonal keratin antibodies, designated AE1, AE2, and AE3, and a polyclonal keratin antibody (RAK) were used for study of the presence of keratin in 121 cases of NPC obtained from China and the United States. AE1 monoclonal antibody, which recognizes keratin protein classes 56.5K, 50K, and 40K, was shown to be the most sensitive and specific for NPC tumor cells among the keratin antibodies studied. In addition, some different keratin expression patterns could be identified between different kinds of epithelium and different tumor groups, with possible relevance to the histogenesis of the histologic subtypes of NPC.  相似文献   
992.
Summary The appearance of myelinated axons and establishment of synaptic contacts in dissociated cells from rat embryo cerebral hemispheres grown on polylysine precoated surfaces were studied by light and electron microscopy. Typical myelin lamellae ensheathing axons were observed as early as the eighth day. Immature synaptic profiles exhibiting slight membrane thickening and few synaptic vesicles were observed after seven days. At 3 weeks, mature synapses containing many synaptic vesicles and the typical irregular membrane thickening could be seen. It is suggested that the presence of polylysine may provide a support which enhances the attachment and subsequent establishment of contacts between neuronal and glial cells, resulting in the early onset of myelin formation.  相似文献   
993.
An H  Yu Y  Zhang M  Xu H  Qi R  Yan X  Liu S  Wang W  Guo Z  Guo J  Qin Z  Cao X 《Immunology》2002,106(1):38-45
Toll-like receptors (TLR) are sentinel receptors capable of recognizing pathogen-associated molecule patterns (PAMP) such as lipopolysaccharide (LPS) and CpG-containing oligonucleotides (CpG ODN). TLR2 and TLR4 are major receptors for Gram-positive and Gram-negative bacterial cell wall components, respectively. TLR9 is necessary for CpG signalling. LPS or CpG ODN can activate immature dendritic cells (DC) and induce DC maturation characterized by production of cytokines, up-regulation of co-stimulatory molecules, and increased ability to activate T cells. However, little is known regarding the regulation of TLR gene expression in mouse DC. In this study, we investigated the regulation of TLR2, TLR4 and TLR9 gene expression by LPS in murine immature DC. TLR2, TLR4 and TLR9 mRNA were up-regulated following LPS stimulation. The up-regulation of TLR9 expression coincided with significantly increased production of tumour necrosis factor-alpha induced by LPS plus CpG ODN. While inhibition of extracellular signal-related kinase and NF-kappaB activation suppressed the up-regulation of the expression of TLR2, TLR4 and TLR9 mRNA, inhibition of p38 kinase prevented the up-regulation of TLR2 and TLR4 mRNA expression but enhanced the up-regulation of TLR9 expression. These results demonstrated that TLR2, TLR4 and TLR9 gene expression was differently regulated by LPS in mouse immature DC. Up-regulation of TLR2, TLR4 and TLR9 expression by LPS might promote the overall responses of DC to bacteria and help to explain the synergy between LPS and other bacterial products in the induction of cytokine production.  相似文献   
994.
BACKGROUND: The role of intravenous (IV) albumin administration in the prevention of ovarian hyperstimulation syndrome (OHSS) and in the improvement of IVF conception outcomes was evaluated in a prospective, randomized, placebo-controlled double blind study. METHODS: Ninety-eight women were enrolled in the study and were consecutively assigned to either a treatment group or a control group. Eleven patients were lost to follow-up after assignment. Of the remaining 87 women, 46 received albumin on the day of oocyte retrieval, and 41 received 0.9% sodium chloride solution as a placebo control. Outcome measures included OHSS incidence rates and pregnancy rates in the two trial groups. RESULTS: Four of the 46 patients in the study group developed severe OHSS and six developed moderate OHSS. In the control group, one of the 41 developed severe OHSS and five developed moderate OHSS. The difference in OHSS incidence rates between the two groups was not statistically significant [relative risk (RR) = 1.49, 95% CI = 0.59-3.73]. Fourteen patients (30%) in the intervention group conceived, compared with 16 patients (39%) in the control group. The difference in conception rates between the two groups was not statistically significant (RR = 0.78, 95% CI = 0.44-1.39). CONCLUSIONS: Albumin appears to have no positive effect on OHSS or conception rates, while its use carries the risk of undesirable side effects, including exacerbation of ascites in OHSS, nausea, vomiting, febrile reaction, allergic reaction, anaphylactic shock and risk of virus and prion transmission. We suggest that this form of treatment should not be included in the prevention of OHSS.  相似文献   
995.
This paper describes an 8-year-old girl with Klippel-Feil syndrome (KFS) associated with frontonasal dysplasia, Sprengel deformity and postaxial polydactyly. These findings are tentatively explained on the basis of a single mutant gene for KFS with broad action in the morphogenesis of the skeletal system.  相似文献   
996.
Dipyridamole at a concentration of 50 μM/ml displays no activity on adsorption and penetration of pseudorabies virus in chicken embryonal cells. Furthermore, first stages of virus replication take place within the nucleus, whereas incomplete virus cores defective in DNA content are found within the nucleoplasm at times when the regular viral replication has been finished in controls. Defective pseudorabies virus particles lacking in DNA-content of the core, can be observed at the end of normal replication time. Consequently, the antiviral activity of dipyridamole may be due to blocking of the synthesis or of the incoporation of infectious viral DNA into the virus core.  相似文献   
997.
By inducing delayed type hypersensitivity (DTH) responses under previously formed skin blisters we determined that cells which mediate natural killer (NK) like cytotoxicity are present in the DTH response in man. Similar levels of killing were not present in cells obtained from skin blisters not associated with positive DTH responses. The DTH response associated killer cell was found to be a mononuclear cell that had presumably undergone stimulation since it not only killed NK sensitive K-562 cells, but also NK resistant Daudi target cells.  相似文献   
998.
研究单次及长期维持血液透析时尿毒症患者血液流变性改变的影响。结果表明,单次血透后,红细胞比积明显升高,红细胞刚性明显降低;血浆粘度、红细胞聚集指数、Casson粘度、血液屈服应力及低切至高切的全血粘度无明显改变。维持血透患者的红细胞比积、血浆粘度、红细胞聚集指数、Casson粘度、血液屈服应力均无明显改变。进一步研究发现,单次血透后血浆渗透比明显降低.这可能是引起红细胞比积升高、红细胞刚性降低的原因之一。  相似文献   
999.
Neurotensin excitation of rat ventral tegmental neurones.   总被引:1,自引:1,他引:1       下载免费PDF全文
1. Whole-cell patch-clamp recordings were made from ventral tegmental area neurones in rat midbrain slices in vitro. In principal cells, which are presumed to contain dopamine, neurotensin (< or = 1 microM) caused an inward current at -60 mV in thirty of forty-seven neurones and had no effect on the remainder. In secondary neurones, neurotensin caused an inward current in twelve of thirty-three cells. 2. The inward current evoked by neurotensin reached a maximum amplitude of about 80 pA, and declined over several minutes when the application was discontinued. The current was most commonly accompanied by a decrease in membrane conductance and reversed polarity at a strongly hyperpolarized potential; this reversal potential was less negative in a higher extracellular potassium concentration. Neurotensin also caused an inward current even in potassium-free internal and external solutions; this current was accompanied by a conductance increase, reversed close to 0 mV and was inhibited by reduction of the extracellular sodium concentration (from 150 to 20 mM). 3. The inward current was associated with a large increase in noise; this persisted in calcium-free solutions but was inhibited by low sodium concentration. The increase in noise was more prominent at hyperpolarized potentials. The amplitude of the unitary current underlying the increase in noise was estimated from the ratio of the variance to the mean as about 1.5 pA at -100 mV. 4. When the recording was made with an electrode containing guanosine 5'-thio-triphosphate, the steady inward current evoked by neurotensin did not reverse when the application was discontinued. When the recording electrode contained pertussis toxin, the action of neurotensin was not different although outward currents evoked by dopamine and baclofen declined with time. 5. It is concluded that neurotensin excites ventral tegmental area neurones by activating a pertussis toxin-insensitive guanosine nucleotide-binding protein. This leads to a reduction in membrane potassium conductance and an increase in membrane sodium conductance, the relative contribution of which varies from cell to cell.  相似文献   
1000.
Morphologically and enzyme histochemically distinguishable tissue macrophages and stromal cells of human reactive lymph nodes were characterized by the cytoplasmic presence of the subunit A of factor XIII and by the expression of surface antigenic determinants reacting with monoclonal antibodies directed against monocyte/macrophage populations (Mo 1, Leu M3) and HLA-DR antigens. The distribution of F-XIIIa positive cells was studied on formaldehyde-fixed paraffin-embedded sections with immunoperoxidase techniques. established on cryostat section with double immunofluorescence. Alpha-Naphthyl acetate esterase (ANAE) reaction was The immunophenotype was established on cryostat sections with double immunofluorescence. Alpha-Naphthyl acetate esterase (ANAE) reaction was carried out on these cryostat sections to identify tissue macrophages. The antibody against F-XIIIa detected histiocytes in both intra- and extra-sinusoidal locations which were ANAE+, Mo 1+, Leu M3+ and HLA-DR-. F-XIIIa was also present in fibroblast-like mesenchymal cells with the following phenotypic characteristics: ANAE-, Mo 1+, Leu M3+ and HLA-DR+. The anti F-XIIIa antibody did not stain lymphoid cells, granulocytes, epithelial cells, endothelial cells and mast cells. The immunohistochemical detection of F-XIIIa works on formaldehyde-fixed paraffin-embedded sections. The most promising application seems to be the identification of histiocytes in lymphoid and histiocytic proliferations.  相似文献   
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