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Increased frequency of rheumatoid factor precursor B lymphocytes after immunization of normal adults with tetanus toxoid. 总被引:21,自引:12,他引:21 下载免费PDF全文
Vaccination of normal adults with tetanus toxoid induced a two-three-fold rise in the frequency of IgM anti-IgG (rheumatoid factor, RF) B lymphocytes inducible by the polyclonal B cell activator, Epstein-Barr virus. The increase in IgM-RF precursors occurred earlier, was greater in magnitude, and was more sustained than the change in plasma IgM-RF. It was associated with a rise in total IgM levels, and correlated positively with the magnitude of the IgG anti-tetanus antibody response, but not with levels of circulating immune complexes. The ability of apparently innocuous infections and immunizations to increase the frequency of IgM-RF precursor B lymphocytes may be the reason for the previously noted expansion in this autoreactive B cell pool between birth and adulthood. 相似文献
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Multipotent, self-renewing stem and progenitor cells isolated from the mammalian central nervous system (CNS) have been shown to survive as allografts following transplantation to sites throughout the neuraxis. However, studies of this type shed little light upon the immunologic properties of the cells themselves, primarily because little is learned about the intrinsic immunogenic properties of a cell when it is grafted into an immune-privileged site. We have therefore investigated the immunogenic and antigenic properties of CNS progenitor cells by grafting them into a conventional (i.e., non-immune-privileged) site, namely, beneath the kidney capsule. Our results indicate that allogeneic CNS progenitor cells survive at least 4 weeks in a conventional site, during which time they neither sensitize their hosts nor express detectable levels of major histocompatibility complex (MHC) class I or II. These in vivo data are in accord with flow cytometric results showing that CNS progenitor cells do not express MHC class I or class II, either at baseline or upon differentiation in 10% serum. Exposure to interferon gamma, however, reversibly upregulates expression of these key transplantation antigens. Together, these results reveal CNS progenitor cells to possess inherent immune privilege. Since CNS progenitor cell allografts were rejected beneath the kidney capsule following specific sensitization of the host, CNS progenitor cells were able to display alloantigens, albeit not in an immunogenic form. 相似文献
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Fong Zhi Ven Sekigami Yurie Qadan Motaz Fernandez-del Castillo Carlos Warshaw Andrew L. Lillemoe Keith D. Ferrone Cristina R. 《Annals of surgical oncology》2021,28(8):4216-4224
Annals of Surgical Oncology - Long-term pancreatoduodenectomy (PD) survivors have previously reported favorable quality of life (QoL). However, there has been a paucity of studies utilizing... 相似文献
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7例尿毒症贫血患者在自发急性缺氧状态下,其血清红细胞生成素(EPO)浓度显著提高(平均7倍),且与PO2呈负相关。缺氧状态纠正后血清EPO浓度下降。提示尿毒症贫血患者的EPO氧依赖调控系统功能尚存在,但处于不敏感的低调状态。进一步了解其机遇,则可能通过促进内源性EPO的生成,有助于悄毒症贫血的治疗。 相似文献
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According to the 1990 census, the highly diverse Asian and Pacific Islander (API) American population has doubled in size from 1980 to 1990, and is now the nation's fastest growing minority group. Several studies have documented this population's comparative underuse of mental health services. A review of recent studies on the mental health of Asian and Pacific Island elders identifies a number of risk factors and protectors. Elder APIs appear to have poorer mental health compared to white counterparts, but not the poorest mental health within their own ethnic group. Within-group differences emerge, with recent immigrant groups and colonized populations appearing as most at-risk for mental health problems. A critical variable on this population's mental health status appears to be socioeconomic status,and yet an analysis of other demographic variables, notably nativity and gender, remain contradictory. A research agenda is proposed and implications for mental health administrators are suggested. 相似文献
19.
Jasmine green tea epicatechins are hypolipidemic in hamsters (Mesocricetus auratus) fed a high fat diet. 总被引:3,自引:0,他引:3
P T Chan W P Fong Y L Cheung Y Huang W K Ho Z Y Chen 《The Journal of nutrition》1999,129(6):1094-1101
These studies were designed to test the hypolipidemic activity of green tea epicatechins (GTE) isolated from jasmine green tea. In Experiment 1, three groups of hamsters were given a semisynthetic diet containing 200 g lard/kg and 1 g cholesterol/kg for 4 wk. The control group received distilled water, and the other two groups received either 15 g/L green tea water extract (GTWE) or 5.0 g/L GTE solution. Both the GTWE and GTE groups had lower concentrations of serum total cholesterol (TC) and triacylglycerols (TG) than the controls (P < 0.05). In Experiment 2, four groups of hamsters received tap water as the drinking fluid, but they were given the same high fat and cholesterol diet supplemented with 0 (control), 1.1, 3.4 or 5.7 g GTE/kg diet. The hypolipidemic effect of jasmine GTE was dose dependent. In Experiment 3, the time-course of changes in serum TC and TG was monitored in hamsters given the high fat diet supplemented with 5.7 g GTE/kg in comparison with that of controls. The hypolipidemic effects of dietary GTE were evident after feeding for 2 wk. Dietary supplementation of GTE did not affect liver fatty acid synthase. However, GTE-supplemented hamsters had higher fecal excretions of total fatty acids, neutral sterols and acidic sterols compared with the control group. In Experiment 4, hamsters were fed nonpurified diet; the control group drank distilled water, and the GTE group drank distilled water containing 5.0 g GTE/L. No differences in activities of 3-hydroxy-3-methyl glutaryl coenzyme A reductase and intestinal acyl CoA:cholesterol acyltransferase were observed. This study suggests that the hypolipidemic activity of GTE is not due to inhibition of synthesis of cholesterol or fatty acid but is most likely mediated by its influence on absorption of dietary fat and cholesterol. 相似文献
20.
Fong KW Ohlsson A Hannah ME Grisaru S Kingdom J Cohen H Ryan M Windrim R Foster G Amankwah K 《Radiology》1999,213(3):681-689
PURPOSE: To determine and compare the diagnostic performance of fetal middle cerebral (MCA), renal (RA), and umbilical (UA) arterial Doppler ultrasonography (US) for prediction of adverse perinatal outcome in suspected intrauterine growth restriction (IUGR). MATERIALS AND METHODS: Two hundred ninety-three small-for-gestational age fetuses (24-39 weeks at recruitment and US-estimated weight or abdominal circumference below 10th percentile) were prospectively examined with Doppler US of the UA, MCA, and RA. Clinicians were blinded to MCA and RA Doppler measurements. RESULTS: Seventy-six fetuses (25.9%) had at least one major or minor adverse perinatal outcome. Major outcomes included stillbirth, neonatal death, neurologic complication, and necrotizing enterocolitis. The MCA pulsatility index (PI), compared with the UA PI and RA PI, was more sensitive (72.4% vs 44.7% and 8.3%) but less specific (58.1% vs 86.6% and 92.6%) in predicting adverse outcome. The UA PI had the highest positive likelihood ratio (ratio, 3.3); the MCA PI had the lowest negative likelihood ratio (ratio, 0.48). When gestational age at the first Doppler US examination was less than 32 weeks, the MCA PI had a sensitivity of 95.5% and negative predictive value of 97.7% for major adverse outcome (negative likelihood ratio, 0.10). CONCLUSION: In suspected IUGR, while an abnormal UA PI is a better predictor of adverse perinatal outcome than an abnormal MCA or RA PI, a normal MCA PI may help to identify fetuses without major adverse perinatal outcome, especially before 32 weeks gestational age. 相似文献