Annexin V for flow cytometric detection of phosphatidylserine expression on B cells undergoing apoptosis

Apoptosis, or programmed cell death, is a general mechanism for removal of unwanted cells from the immune system. It is characterized by chromatin condensation, a reduction in cell volume, and endonuclease cleavage of DNA into oligonucleosomal length fragments. Apoptosis is also accompanied by a loss of membrane phospholipid asymmetry, resulting in the exposure of phosphatidylserine at the surface of the cell. Expression of phosphatidylserine at the cell surface plays an important role in the recognition and removal of apoptotic cells by macrophages. Here we describe a new method for the detection of apoptotic cells by flow cytometry, using the binding of fluorescein isothiocyanate-labeled annexin V to phosphatidylserine. When Burkitt lymphoma cell lines and freshly isolated germinal center B cells are cultured under apoptosis inducing conditions, all cells showing chromatin condensation strongly stain with annexin V, whereas normal cells are annexin V negative. Moreover, DNA fragmentation is only found in the annexin V-positive cells. The nonvital dye ethidium bromide was found to stain a subpopulation of the annexin V-positive apoptotic cells, increasing with time. Our results indicate that the phase in apoptosis that is characterized by chromatin condensation coincides with phosphatidylserine exposure. Importantly, it precedes membrane damage that might lead to release from the cells of enzymes that are harmful to the surrounding tissues. Annexin V may prove important in further unravelling the regulation of apoptosis.     

Multimodal Surgical Approach for Adult Patients With Chronic Intestinal Pseudo-Obstruction: Clinical and Psychosocial Long-term Outcomes

Background

Clinical and psychosocial outcomes of a multimodal surgical approach for chronic intestinal pseudo-obstruction were analyzed in 24 patients who were followed over a 2- to 12-year period in a single center after surgery or intestinal/multivisceral transplant (CTx).

Chronic lymphocytic leukemia B cells contain anomalous Lyn tyrosine kinase, a putative contribution to defective apoptosis

B cell chronic lymphocytic leukemia (B-CLL) is a neoplastic disorder characterized by accumulation of B lymphocytes due to uncontrolled growth and resistance to apoptosis. Analysis of B cells freshly isolated from 40 patients with chronic lymphocytic leukemia demonstrated that the Src kinase Lyn, the switch molecule that couples the B cell receptor to downstream signaling, displays anomalous properties. Lyn is remarkably overexpressed at the protein level in leukemic cells as compared with normal B lymphocytes, with a substantial aliquot of the kinase anomalously present in the cytosol. Whereas in normal B lymphocytes Lyn activation is dependent on B cell-receptor stimulation, in resting malignant cells, the constitutive activity of the kinase accounts for high basal protein tyrosine phosphorylation and low responsiveness to IgM ligation. Addition of the Lyn inhibitors PP2 and SU6656 to leukemic cell cultures restores cell apoptosis, and treatment of malignant cells with drugs that induce cell apoptosis decreases both activity and amount of the tyrosine kinase. These findings suggest a direct correlation between high basal Lyn activity and defects in the induction of apoptosis in leukemic cells. They also support a critical role for Lyn in B-CLL pathogenesis and identify this tyrosine kinase as a potential therapeutic target.     

Serologic test for syphilis as a surrogate marker for human immunodeficiency virus infection among United States blood donors

BACKGROUND: This study evaluated the usefulness of the serologic test for syphilis (STS) in preventing the transmission of human immunodeficiency virus (HIV), hepatitis B and C viruses, and human T- lymphotropic virus via the transfusion of seronegative, infectious window-period blood. STUDY DESIGN AND METHODS: Demographic and laboratory information on blood donations made between January 1992 and June 1994 in 18 American Red Cross regions was analyzed. It was assumed that the same proportion of HIV-positive and HIV-infectious window- period donations reacted on STS and were negative on other screening tests (hepatitis B and C viruses and human T-lymphotropic virus). This proportion multiplied by the estimated number of HIV-infectious window- period donations is the number of post-screening HIV-infectious donations removed by STS. RESULTS: Of 4,468,570 donations, 12,145 (0.27%) were STS positive and 377 (0.008%) were HIV positive. Among donations that were negative on other screening tests, STS-reactive donations were 12 times more likely to be HIV positive (odds ratio = 11.9; 95% CI = 5,26). However, of an estimated 13 infectious window- period donations, 0.2 would have been removed because of a reactive STS, at a cost of over $16 million. CONCLUSION: STS is a poor marker and a costly strategy for preventing post-screening HIV infections and other blood-borne diseases.     

Polycystic Kidney Disease Re-evaluated: A Population-based Study

A genetic register of all known cases of autosomal dominantpolycystic kidney disease occurring in South and Mid-Wales hasbeen established. In a population of 2.1 million, 209 familieswith affected members were identified, 303 of whom are currentlyalive, 70 on renal replacement therapy. An additional 551 caseswould be predicted amongst family members at 50 per cent and25 per cent risk, giving an apparent prevalence of 1:2459 inthe general population. Five possible new mutations were seenwhere adults with phenotypic autosomal dominant polycystic kidneydisease had both parents alive, age > 55 years with no cystsvisible on ultrasound. The take-on rate for renal replacementtherapy increased during 1970–79 but has apparently reacheda plateau of 4.8 cases per million population per year overthe last 8 years, despite a rapidly increasing acceptance ofuraemic patients as a whole (72/10⁶/year in 1988–89).Considerably more patients with autosomal dominant polycystickidney disease aged over 50 years were started on treatmentin 1980–89 than in 1970–79, but the survival overallimproved with time. All cases of autosomal dominant polycystickidney disease reaching end-stage renal disease are now beingtreated, but the apparent clinical prevalence of this conditionin our region is less than half the supposed gene frequency,suggesting that undiagnosed cases have a benign prognosis.     

Inhalational anesthetics inhibit spreading depression: relevance to migraine

Cortical spreading depression (SD) has not been shown in the human neocortex by direct cortical recordings. However, animal studies suggest that cortical injury, such as that occurring during neurosurgical procedures, should result in the initiation of SD. It is possible that inhibition of SD by volatile anesthetic agents may partially explain the failure to observe SD in the human neocortex during surgery. This study examines the effect of the anesthetic agents α-chloralose, halothane, nitrous oxide and isoflurane on the initiation of cortical SD in the cat neocortex. SD was seen in 100% of cats anesthetized with α-chloralose ( n = 15), in 3 of 7 (42%) animals anesthetized with isoflurane ( p < 0.05, χ² with Yates correction) and none of the animals ( n = 4, 6 hemispheric preparations) anesthetized with halothane ( p < 0.005, χ² with Yates correction, halothane vs α-chloralose group). In all cases this inhibitory effect was reversible. In four animals the administration of nitrous oxide (66%) reduced the inspired concentration of isoflurane required to inhibit SD by 0.75%. This study suggests that halothane, and to a lesser extent isoflurane and nitrous oxide, protect against the initiation of cortical SD. This observation may partially explain why SD has not been demonstrated in human neocortex during surgery. Further studies are needed to determine if SD may occur under pathological conditions, such as during migraine with aura, where the cortex may be predisposed to SD.     

Esophagogastric junction gastrointestinal stromal tumor: Resection vs enucleation

Esophageal gastrointestinal stromal tumors(GISTs) are extremely uncommon,representing approximately 5% of GISTs with the majority of esophageal GISTs occurring at the esophagogastric junction(EGJ).The treatment options available for these GISTs are fairly controversial.Many different options are nowadays at our disposal.From surgery to the target therapies we have the possibility to treat the majority of GISTs,including those which are defined as unresectable.The EGJ GISTs represent a stimulating challenge ...     

文献计量学分析我国双相情感障碍的发展趋势

目的通过分析我国双相情感障碍的文献分布,探讨我国双相情感障碍的发展趋势。方法采用文献计量学方法和MicrosoftExcel技术,通过利用中国生物医学文献数据库中收录的有关以双相情感障碍为主题的文献,从时间分布、单位分布、地域分布、期刊分布、第一作者分布和主要内容等方面,进行多角度文献分析。结果双相情感障碍文献的时间分布、单位分布、地域分布与地区经济发展密切相关;浙江常州全军精神卫生中心解放军第102医院、深圳市精神卫生研究所（深圳市精神卫生中心）、南京医科大学附属脑科医院及在以上单位工作的作者可视为该病的核心研究机构和研究者;《临床精神医学杂志》（6．67％）、《四川精神卫生》（5．14％）、《上海精神医学》（4．72％）、《中国神经精神疾病杂志》（4．16％）可视为该病研究的核心期刊;国内学者对该病的研究主要集中于临床药物治疗、临床诊断、临床病例报告（约占临床研究的61．98％）、流行病学调查（约占预防医学研究的63％）等方面,对于双相情感障碍预防方面（约占论文总数的28．97％）及合并外科疾病围手术期（约占临床研究的4．04％）的专题研究报道较少。结论双相情感障碍研究在国内尚处于初步研究阶段,各地区发展不平衡,对该病的预防和治疗认识不足。各地区应重视该病的防治工作,建立预警机制,制定相应防治措施,防止该病的流行和突发事件的发牛。     

儿童颈动脉内-中膜厚度与肥胖类型相关性的超声评价

目的应用超声手段探测儿童颈动脉内膜-中层厚度（IMT）,探讨其与儿童肥胖类型的关系。方法依体质指数（BMI）、腰围身高比（WHtR）标准,入组外周性肥胖组160名（A组）,内脏性肥胖150名（B组）,正常体重儿童160名（正常对照组）;应用超声手段探测各组儿童内脏脂肪厚度（VFT）和颈动脉内膜-中层厚度,比较3组间各项检测参数。结果内脏肥胖组VFT、IMT均高于外周性肥胖组及正常组,差异具有统计学意义（P〈0.05）;外周性肥胖组VFT、IMT与正常组相似,差异没有显著性。结论IMT与肥胖类型相关,内脏性肥胖儿童VFT、IMT增加。实时超声检查技术为研究儿童肥胖类型提供了一种新的检测手段。