肿瘤坏死因子α诱导蜕膜细胞凋亡模型建立及黄芩苷对蜕膜细胞凋亡的影响

目的:探索建立肿瘤坏死因子诱导蜕膜细胞凋亡模型,观察黄芩苷对早孕蜕膜细胞凋亡的影响,初步分析黄芩清热安胎作用机制。方法:实验于2006-04/09在湖南中医药大学国家重点二级实验室病理生理实验室完成。取湖南中医药大学第一附属医院门诊人流手术室正常妊娠40d健康孕妇人流组织,患者知情同意。体外常规进行蜕膜细胞培养,选取经鉴定的4、5代细胞蜕膜细胞,用不同浓度(0.5,2.0,10.0,50.0μg/L,共设4组,并设空白对照组)的肿瘤坏死因子α作用于蜕膜细胞,四甲基偶氮唑盐比色实验分析肿瘤坏死因子α对蜕膜细胞活力的影响,荧光细胞染色观察确定蜕膜细胞凋亡模型的建立。选取适宜浓度的黄芩苷作用于正常蜕膜细胞及肿瘤坏死因子α诱导的凋亡蜕膜细胞(设肿瘤坏死因子α模型组,黄芩苷组,肿瘤坏死因子α加黄芩苷组,并设空白对照组),培养24h后,四甲基偶氮唑盐比色实验分析黄芩苷对蜕膜细胞活力的影响,流式细胞术检测细胞凋亡率。结果:实验成功获取足够量的细胞,经泌乳素免疫组化鉴定为较高纯度的蜕膜细胞。①肿瘤坏死因子α作用后的蜕膜细胞活性均低于空白对照组,并且随着肿瘤坏死因子α浓度越大,活力越小。10.0,50.0μg/L肿瘤坏死因子α作用后蜕膜细胞活性与空白对照组比较,差异有显著性意义[(0.196±0.040),(0.106±0.020),(0.317±0.020),P<0.05]。但50.0μg/L时经形态学观察有部分细胞漂浮、死亡。②肿瘤坏死因子α模型组蜕膜细胞活性低于黄芩苷组和肿瘤坏死因子α加黄芩苷组,差异具有显著性意义[(0.27±0.03),(0.49±0.01),(0.38±0.02),P<0.05]。③流式细胞术示空白对照组蜕膜细胞凋亡率低于其他各组,差异均有显著性意义[(1.48±0.45)%,(16.40±0.82)%,(9.78±0.26)%,(10.96±0.92)%,P<0.05]。在荧光显微镜下,肿瘤坏死因子α作用后凋亡的蜕膜细胞细胞核变小皱缩,可见致密强荧光。结论:肿瘤坏死因子α能明显抑制人蜕膜细胞增殖分裂的过程,诱导该细胞凋亡,可用于人蜕膜细胞凋亡模型的建立。而黄芩苷对肿瘤坏死因子α诱导的蜕膜细胞凋亡具有一定对抗抑制作用。     

Gastrointestinal bleeding during an ultramarathon

Digestive symptoms and gastrointestinal bleeding occur in endurance runners and may contribute to runner's anemia. The cause is unknown, but the frequency of fecal blood loss has been reported to be 8–23% of marathon runners (1–7). Races of longer distances have not been investigated. An ultramarathon is a race that is longer than the 26.2 miles of a marathon and commonly involves distances of 30–100 or more miles and can last 24 hr or more. It differs from the marathon in duration, pace, and intrarace diet. The Old Dominion One Hundred Mile Endurance Run is held in the mountains of Virginia each June. It is open only to experienced ultrarunners who have completed a 50-mile race in less than 9 hr. This race offers a unique opportunity to study highly trained individuals undergoing a tremendous stress to not only their cardiovascular and musculoskeletal systems but also to their gastrointestinal system. The purpose of this prospective study is to determine the incidence of Hemoccult positivity occurring in association with an ultramarathon and evaluating, by means of a questionnaire, cofactors contributing to the gastrointestinal bleeding.The opinions and assertions contained herein are those of the authors and are not to be construed as reflecting the views of Walter Reed Army Medical Center, the Department of the Army or the Department of Defense.     

Does review of peripheral blood smears help in the initial workup of common anemias?

Sixty-five physicians were tested to determine the effect of their reviews of red blood cell morphology on their subsequent diagnoses of and workup plans for common anemias. The subjects read clinical and laboratory data for six pairs of cases of anemia, reviewing the blood smear for one case in each pair. They correctly identified the presence or absence of morphologic features on the blood smears 82% of the time. In spite of excellent morphologic discrimination, the number of tests ordered was not affected by blood smear review. In fact, the quality of the physicians’ workup plans, measured by numbers of tests appropriately ordered and excluded, was slightly but significantly better when they did not review the smears (p<0.005). In addition, smear review did not significantly improve diagnostic accuracy for any of the common anemias studied. Significantly more correct diagnoses were made without smear review for vitamin B₁₂-folate deficiency anemia (p<0.015) and thalassemia (p<0.0001). Although routine review of blood smears by physicians in the management of common anemias may provide useful information, the authors were unable to demonstrate an improvement in the number or appropriateness of tests ordered or diagnostic accuracy in spite of excellent morphologic discrimination. Received from the Divisions of General Internal Medicine and Hematology, Department of Medicine, Walter Reed Army Medical Center, Washington, DC, and the Uniformed Services University of the Health Sciences, Bethesda, Maryland. Dr. Simmons is now Chief, Division of General Internal Medicine, Brooke Army Medical Center, San Antonio, Texas. Presented in part at the annual meeting of the American Federation of Clinical Research, Washington, DC, May 3, 1986. Supported by a grant from the Department of Clinical Investigation (WU 1013), Walter Reed Army Medical Center, Washington, DC 20307-5001. The opinions and assertions contained herein are the private ones of the authors and are not to be construed as official or as reflecting the views of the Department of Defense, the Department of the Army, or the Uniformed Services University of the Health Sciences.     

Management of alloimmune thrombocytopenia: antenatal diagnosis and in utero transfusion of maternal platelets

Neonatal alloimmune thrombocytopenia (NAIT) can cause severe bleeding in the central nervous system (CNS) and death or severe neurologic sequelae. The expression of the PLA1 antigen is detectable as early as 19 weeks of gestation. Alloimmunization can therefore lead to fetal thrombocytopenia very early in pregnancy. Until recently, we have had no means of detecting and assessing the severity of fetal thrombocytopenia during pregnancy. The level of the maternal antibody is not of a predictable value since 20% of the mothers had no circulating antibodies in our series. An alternative approach is to carry out investigations on fetal blood samplings. This management leads to an exact knowledge of the fetal status and antenatal diagnosis is feasible as early as the 21st week of gestation. Early diagnosis facilitates appropriate management and makes possible such therapeutic options as in utero maternal platelet transfusions. We report our experience in the antenatal diagnosis and management of nine cases with in utero transfusion in the six cases with severe thrombocytopenia. All neonates did well, with no signs of bleeding at birth. No side effects of therapy were noted after a period ranging from 6 months to 3 years.     

Effect of HLA Bw4/Bw6 compatibility on platelet transfusion responses of refractory thrombocytopenic patients

Platelet transfusions from donors matched for cross-reactive antigens have been shown to be effective in providing hemostasis in alloimmunized thrombocytopenic patients. A significant number of these transfusions, however, fail to provide posttransfusion platelet recoveries. We investigated incompatibility in the Bw4/bw6 system as a possible explanation for these failures. The Bw4/Bw6 system is a biallelic antigen system closely associated with HLA-B. HLA-B locus antigens that are cross-reactive frequently differ in their Bw4/Bw6 specificity. Posttransfusion platelet recoveries from 21 alloimmunized thrombocytopenic patients homozygous for Bw4 or Bw6 and transfused with both Bw4/Bw6 compatible and incompatible platelets were analyzed. The mean 1-hr posttransfusion recovery was 84% following Bw4/Bw6-compatible platelets versus 52% with Bw4/Bw6-incompatible platelets (p less than 0.02). Twenty-four hours following transfusion, mean recoveries were 44% and 24%, respectively, (p less than 0.01). A subgroup of 8 patients (38%) was identified who had markedly lower responses following Bw4/Bw6- incompatible transfusions as compared to Bw4/Bw6-compatible transfusions (mean recoveries: 1 hr--compatible 100%, incompatible 27%, p less than 0.001; 24 hr--compatible 45%, incompatible 7%, p less than 0.01). These data suggest that the Bw4/Bw6 antigen system has clinical significance for some patients requiring platelet transfusion therapy and, when appropriate, should be considered in the selection of donors.     

Neutrophil adhesiveness during prostacyclin and heparin hemodialysis

We evaluated neutrophil adhesive function in patients undergoing chronic hemodialysis using either prostacyclin or heparin as antithrombotic agents. Patients underwent successive hemodialyses with prostacyclin (4 ng/kg/min) and heparin. There were no significant differences noted in neutrophil adhesive function during either dialysis: transient neutropenia developed in each case; impaired neutrophil adhesiveness to plastic developed during both dialyses; neutrophil aggregation was diminished when compared to predialysis responses during both dialyses. Furthermore, the number of circulating Fc-receptor-bearing neutrophils fell significantly during both prostacyclin and heparin hemodialysis. Our study demonstrates that substitution of prostacyclin for heparin in doses that do not cause hypotension, does not prevent neutropenia or alter the diminished neutrophil adhesiveness that occurs during heparin hemodialysis.