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671.
CT1 is a carbohydrate moiety of CD45 that is expressed on fetal thymocytes
in vivo. Examination of CT1 expression on thymocyte subsets revealed that
primarily pro-T cells (CD44+ CD25+) and pre-T cells (CD44- CD25+) expressed
CT1. Interestingly, non-T-lineage committed lymphoid progenitors (CD44+
CD25-) lacked CT1 indicating temporal regulation of expression of this
determinant in early T-lineage committed development. In addition, CT1 was
expressed by the majority of thymocytes in RAG-2(-/-) mice where thymocyte
development is blocked at the CD44- CD25+ stage. Since late pre-T cells
(CD44- CD25-) lacked the CT1 epitope we tested whether pre-TCR triggering
regulated CT1 expression. Injection of CD3epsilon-specific mAb into
RAG-2(-/-) mice induces differentiation of immature thymocytes to the
double-positive stage of thymocyte development. Using this system, we
demonstrated that expression of CT1 by RAG-2(-/-) thymocytes was rapidly
lost from pre-T cells following anti-CD3 mAb treatment. Furthermore, the
decline in CT1 expression induced by CD3 signaling paralleled a loss of
mRNA for the glycosyltransferase responsible for the addition of CT1 to
CD45. Flow cytometric analysis also revealed that the loss of the CT1
epitope was inversely correlated with an increase in peanut agglutinin
ligand expression, demonstrating a complex regulation of cell surface
glycosylation at a critical juncture in thymocyte development.
相似文献
672.
沙尘天气大气颗粒物对学龄儿童最大呼气流速的影响 总被引:1,自引:0,他引:1
目的 研究沙尘天气颗粒物浓度与学龄儿童最大呼气流速(PEFR)之间的关系.探讨沙尘天气颗粒物对儿童肺功能的影响.方法 于2006年4月27日-6月5日连续40d对内蒙古包头市1所小学107名四年级小学生进行每日3次PEFR的测定,同时监测和收集每日大气PM2.5、PM1O、NO2和SO2浓度以及气温和相对湿度,通过问卷调查了解儿童年龄、性别、身高、体重、哮喘病史、慢性呼吸系统疾病家族史、被动吸烟等情况.应用线性混合效应模型,在控制了个体特征、气象因素的情况下估计PM2.5和PM10对儿童PEFR的影响.结果 单污染物模型和多污染物模型均显示,PM2.5和PM10的日均浓度与沙尘天气当日及之后3 d内儿童的PEFR日均值都存在明显的负相关(P<0.01),其中以滞后1 d的效应最强.在多污染物模型中调整了NO2和SO2的影响之后,PM2.5和PM10的日均浓度每增加10μg/m3,儿童PEFR在沙尘天气1 d之后的日均值就分别降低0.245和0.121 L/min,有统计学意义(P<0.01).结论 学龄儿童PEFR日均值下降与包头市沙尘天气颗粒物浓度的升高有关. 相似文献
673.
David Fluck Christopher H. Fry Jonathan Robin Ellen Bull Andrea Lewis Jacqui Rees Gareth Jones Liz Taylor Thang S. Han 《International journal of mental health nursing》2023,32(4):1138-1147
We measured rates of hospital admissions for mental health disorders and self-poisoning during the pandemic in patients without COVID-19, compared to those admitted before the pandemic. Data were collected from 01/04/2019 to 31/03/2021, including the pandemic period from 01/03/2020. There were 10 173 (47.7% men) from the pre-pandemic and 11 019 (47.5% men) from the pandemic periods; mean age = 68.3 year. During the pandemic, admission rates for mental health disorders and self-poisoning were higher for any given age and sex. Self-poisoning was increased with toxic substances, sedatives and psychotropic drugs, but reduced with nonopioid analgesics. Patients admitted with mental health disorders had lower readmission rates within 28 days during the pandemic, but did not differ in other outcomes. Outcomes from self-poisoning did not change between the two study periods. 相似文献
674.
675.
H. Barry Waldman DDS MPH PhD Steven P. Perlman DDS MScD. DHL Allen Wong DS EdD 《Special care in dentistry》2017,37(4):159-163
A recent series of reports in Health Affairs reviewed the disparities in securing needed oral health services in the U.S. Despite an extensive oversight of the many issues involved, no direct mention is made of the particular conditions of the largest minority population in the U.S. unable to access dental care—the tens of millions of individuals with special health care needs. A review is provided of the particular barriers and conditions faced by this increasing population in its efforts to secure needed services. 相似文献
676.