The cell and molecular basis of leukocyte common antigen (CD45)- triggered, lymphocyte function-associated antigen-1-/intercellular adhesion molecule-1-dependent, leukocyte adhesion

We recently reported that cross-linking the leukocyte common antigen (CD45) can rapidly induce aggregation of human peripheral blood mononuclear cells via lymphocyte function-associated antigen-1 (LFA-1) and intercellular adhesion molecule-1 (ICAM-1) interactions. Herein, we have examined both T-cell--monocyte cellular interactions and the molecular signaling that are involved in this phenomenon. Experiments using highly purified T lymphocytes showed that CD45-induced aggregation requires the presence of both T cells and monocytes. Cross- linking CD45 only on T lymphocytes, but not on monocytes, initiated cellular clustering after reconstituting to the respective untreated cell type. By several criteria, CD45-induced clustering of T cells to autologous monocytes was shown to be Fc-receptor--independent. When comparing intracellular signaling in leukocyte aggregation induced by CD45 cross-linking versus phorbol myristate-12-13-acetate (PMA) treatment, the former was found to be fivefold to 10-fold more sensitive to H-8, a reagent that effectively blocks cAMP- and cGMP- dependent protein kinases. On the other hand, reagents that increase intracellular cAMP levels (eg, dbcAMP, forskolin, and IBMX), protein kinase C (PKC) inhibitors (eg, staurosporine), and tyrosine kinase inhibitors (eg, herbimycin A and genistein) all readily inhibited PMA- induced, but not CD45 monoclonal antibody-induced, aggregation. We conclude that cross-linking the leukocyte common antigen on T cells induces LFA-1--/ICAM-1--dependent T-cell--monocyte aggregation through a unique signaling pathway independent of PKC, which involves instead cAMP-/cGMP-dependent protein kinases.     

Ethnicity, socioeconomic status, transfusions and risk of hepatitis B and hepatitis C infection

This study identifies the risk factors for hepatitis B virus (HBV) and hepatitis C virus (HCV) and measures the prevalence of hepatitis B surface antigen (HBsAg) and antibody to hepatitis C (anti-HCV) in the general population of Jakarta. A population-based sample of 985 people aged 15 and above was surveyed. Risk factors were identified through questionnaires and home visits. Serum was analysed for HBsAg, antibody to hepatitis B surface antigen (anti-HBs), anti-HCV, aspartate aminotransferase (AST) and alanine aminotransferase (ALT). The seroprevalence was: 4.0% (39/985) for HBsAg, 17.2% (170/985) for anti-HBs, and 3.9% (38/985) for anti-HCV. The risk factors for hepatitis B and hepatitis C infection had little in common. Low socioeconomic status was a strong risk factor for HBsAg (adjusted odds ratio (OR) 18.09; 95% confidence interval (CI) 2.35–139.50). In addition, the Chinese group has 2.97 higher risk of having HBV infection compared with the Malayan ethnic group (adjusted OR 2.97; 95% CI 1.22–7.83). There was moderate positive trend between family size and risk of HBsAg positivity (P= 0.130). Age over 50 (adjusted OR 14.72; 95% CI 4.35–49.89) and history of transfusion were significant risk factors for hepatitis C (adjusted OR 3.03; 95% CI 1.25–7.33). Hepatitis B and hepatitis C infections have different risk factors in Jakarta, a high risk in population for both diseases. Hepatitis B transmission is associated with low socioeconomic status, Chinese ethnic group and large family size, while hepatitis C is associated with an older age and a history of transfusions.     

浙江省4个地区60岁以上老人生活满意度的调查

目的:了解浙江省农村老年人生活满意度的现状及其有关影响因素。方法:于2005-07/10随机抽取浙江省乐清市北白象镇、白石镇、大荆镇,建德市的莲花镇及杭州下沙区和余杭区内能回答调查问卷的各项内容,同意参与该项调查的60岁以上老年人430名为调查对象。应用WHO推荐的生活满意度指数A量表,一般状况调查表,最满意和最不满意的事情调查表进行入户问卷调查。生活满意度指数A量表,包括20个项目,其中12个条目反映正性情感,8个条目反映负性情感。每项最高分为2分,总分最高分为40分。评分越高,生活质量越佳。一般状况调查表包括姓名、年龄、性别、职业、文化程度、婚姻、健康状况、医疗费用来源、住址和联系电话。结果:共发放问卷430份,收回有效问卷389份。①389名老年人生活满意度评分为25.8±7.2,与正常值(12.4±4.4)比较,差异有显著性意义(P<0.05)。②经多个独立样本的非参数检验,老年人的生活满意度评分性别差异无显著性(P>0.05),而在年龄、婚姻、文化程度、健康状况、职业、医疗费用来源和所在地区维度差异有显著性(P≤0.05)。③313人对“最满意和最不满意的事情”项目进行了回答,老年人最满意的事是“生活条件改善”和“家庭关系和睦”,有195人,占62.3%,最不满意的事主要是“家庭不和睦”(17.4%)、“社会发展不佳”(14.8%)、“身体状况差”(14.2%)、“生活条件差”(10.3%)。结论:浙江省农村老年人生活满意度较高,年龄、婚姻、文化程度、健康状况、职业、医疗费用来源、地区差异对老年人生活满意度有重要影响。     

Microbiologic contamination of peripheral blood progenitor cells collected for hematopoietic cell transplantation

BACKGROUND: Peripheral blood progenitor cells (PBPCs) rather than bone marrow are used increasingly to provide hematologic reconstitution when transfused after marrow-ablative chemotherapy. PBPCs often are collected via central venous catheters that have remained in place for long periods of time and that may become infected. STUDY DESIGN AND METHODS: The investigators reviewed their 5-year experience in collecting PBPCs for the prevalence of bacterial contamination. Except for cotrimoxazole therapy given to prevent Pneumocystis cariini pneumonia, patients were not given antibiotic prophylaxis. RESULTS: Each patient underwent a median of 7 (range, 2–21) PBPC collections; 0.2 percent (3/1040 collections) were culture positive for bacteria (two collections contained coagulase-negative staphylococci and one contained Serratia marcescens). All culture-positive collections were discarded; no PBPCs were culture positive at the time of thawing and transfusion. CONCLUSION: This contamination rate is below that previously reported for bone marrow harvests and platelet concentrate collections. Obtaining PBPCs through large-bore central venous catheters has not added to the risk of infection in transplant patients. A program of screening in vitro cultures and strict adherence to sterility techniques can result in very low microbiologic contamination and thus obviates the need for prophylactic antimicrobials in the PBPCs and in the patient.     

CLIMACTERIC SYMPTOMS IN HEALTHY MIDDLE-AGED WOMEN

SUMMARY The incidence of climacteric symptoms was determined in 247 healthy premenopausal women in a community setting. These volunteers had been recruited to a longitudinal study of bone density. Of these subjects, 46 ceased to menstruate during the study, and in this subgroup symptoms were compared before and after cessation of menstruation. Only hot flushes increased after cessation of menstruation in the longitudinal study and showed age correlation in the cross-sectional study. Hot flushes thus emerged as a true menopausal symptom. Although evidence for this is weaker, cold sweats and suffocation seem likely to be genuinely menopausal. Breast discomfort and the four mood symptoms of irritability, excitability, depression and poor concentration improved after cessation of menstruation, and this study gives no support for their being part of the menopausal syndrome; it suggests that these symptoms are more likely to be related to menstruation than to the menopause.     

Nonrandom chromosome abnormalities in acute leukemia and dysmyelopoietic syndromes in patients with previously treated malignant disease

Cytogenetic studies were performed on 26 patients who developed acute nonlymphocytic leukemia (ANLL) or a dysmyelopoietic syndrome after treatment of a primary malignancy. Fifteen patients had radiotherapy and chemotherapy, seven had only chemotherapy, and four had only radiotherapy. The median times from diagnosis of the initial disease to the development of bone marrow dysfunction for these treatment groups were 50, 46, and 49 mo, respectively. Twenty-five patients had an abnormal karyotype in myeloid cells. Loss of part or all of no. 5 and/or no. 7 was noted in 23 of 25 patients with aneuploidy. Loss of no. 5 was noted only in patients who previously had malignant lymphoma, whereas loss of no. 7 was seen in these patients as well as in those who had other malignancies. Abnormalities of both nos. 5 and 7 occurred in 53% of the patients treated with combined therapy and in only 27% of patients treated with either modality alone. Although these changes are distinctly different from those noted in lymphomas, they are similar to those seen in 25% of aneuploid patients with ANLL de novo.     

Hypoxic hepatitis in children after cardiac surgery

<正>To the Editor: Hypoxic hepatitis(HH), also known as ischemic hepatitis or shock liver, is a liver injury characterized by necrosis of centrilobular hepatocytes with a rapid increase in serum aminotransferase levels. The incidence rate of HH among patients in the intensive care unit(ICU) was found to be 0.9%-11.9% [1]. Occurrence of HH appears to have a significant impact on the clinical outcome.     

A voluntary serosurvey and behavioral risk assessment for human immunodeficiency virus infection among college students.

The authors conducted a voluntary serosurvey and educational campaign among 3394 undergraduate students attending the University of Maryland at College Park to determine the prevalence of and risk factors for human immunodeficiency virus type 1 (HIV-1) infection. Two students were seropositive (0.06%, 95% confidence interval 0-0.15%). Both were homosexual men with multiple sexual partners. Despite the low prevalence of infection, potential risk factors for transmission of HIV-1 were common, as assessed by a self-administered anonymous questionnaire. These included a previous sexually transmitted disease (12.6%), male homosexual intercourse (4.8% of men), heterosexual anal intercourse (25.3%), heterosexual intercourse with a person at risk (an HIV-1 infected person, a bisexual man, a parenteral drug user, a female prostitute, or a hemophiliac) (5.2%), multiple sexual partners (21% reported 10 or more lifetime partners), and intravenous drug use (1.3%). Assessment of the efficacy of our program by comparing responses on pre- and post-test questionnaires showed gains in knowledge about heterosexual transmission of HIV-1 and an increase in the reported frequency of condom use 1-2 months after participating in the survey. The authors conclude that HIV-1 infections are occurring among college students but in our study group remain confined to persons with known high-risk behavior; however, practices that may support transmission are common, and programs designed to diminish these behaviors among college students are needed.