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.     

Efficacy of smoking prevention program 'Smoke-free Kids': study protocol of a randomized controlled trial

Background  

A strong increase in smoking is noted especially among adolescents. In the Netherlands, about 5% of all 10-year olds, 25% of all 13-year olds and 62% of all 17-year olds report ever smoking. In the U.S., an intervention program called 'Smoke-free Kids' was developed to prevent children from smoking. The present study aims to assess the effects of this home-based smoking prevention program in the Netherlands.     

Behavioral and biochemical effects of chronic consumption of ethanol by hamsters

Male Syrian Golden-Hamsters consumed about 90% of their fluid as an ethanol-water solution when given a choice between water and ethanol-water solutions. This resulted in a daily alcohol intake of about 11 g/kg. After 53 days of alcohol ingestion there was no evidence of tolerance to the soporific effects of parenterally administered ethanol and removal of the ethanol solutions failed to produce any signs of alcohol withdrawal. However, after cessation of ethanol ingestion, the acquisition of escape responding from footshock was impaired in the alcohol group as compared to a control group. Biochemical and ultrastructural analyses demonstrated that chronic ethanol ingestion hepatic glycogen and plasma triglycerides without altering either the hepatic or plasma concentrations of phospholipids, free cholesterol or cholesterol esters. These results demonstrate that the hamster has an unusual metabolic response to ethanol. These findings are contrasted to the biochemical and behavioral effects of the drug in other species.     

The epidemiology of arm and hand swelling in premenopausal breast cancer survivors.

BACKGROUND: Breast cancer survivors suffer from lymphedema of the arm and/or hand. Accurate estimates of the incidence and prevalence of lymphedema are lacking, as are the effects of this condition on overall quality of life. METHODS: Six hundred twenty-two breast cancer survivors (age, 相似文献   

2′ deoxycoformycin (pentostatin) for refractory non-Hodgkin's lymphoma: A calgb phase II study

Seventy-six eligible patients with relapsed or refractory non-Hodgkin's lymphoma (NHL) were treated with 2′-deoxycoformycin (pentostatin) at a dose of 4 mg/m² intravenously weekly for three weeks and then every other week for a minimum of five total treatments. All patients had measurable disease, near normal hematologic, renal, and hepatic function, and a performance status of 0 or 1. Severe hematologic toxicity was observed in 13% of patients; severe renal or neurologic toxicity was observed in less than 5% of patients. There were no treatment-related deaths. Objective therapeutic responses were seen in 16% of patients (five complete response [CR] and seven partial response [PR]). However, in three of the patients achieving CR and one patient achieving PR, dexamethasone was employed as an anti-emetic, making the response of these patients to pentostatin difficult to evaluate. There were eight responses (3 CR) in patients with diffuse histologies and four responses (2 CR) in patients with nodular or mixed histologies. Three responses were in patients with a T-cell phenotype. Three of five patients with diffuse well-differentiated lymphoma (IWF A) responded. We conclude that 2′ deoxycoformycin is only minimally active at this dose and schedule against refractory or relapsed NHL. The possibility that low grade B- and T-cell malignancies are more sensitive to 2′ deoxycoformycin deserves further investigation.     

Allied health outcomes research using a collaborative distance approach

As part of an activity sponsored by the Coalition for Allied Health Leadership, individuals representing various allied health disciples formed a team to develop a presentation and bibliography on outcomes research in allied health. Team members worked with each other while geographically separated, and concluded that several factors contributed to the difficulty the team encountered in working together in a truly collaborative manner. However, the team's efforts did result in a viable presentation on outcomes research in allied health to include definition and parameters, a discussion of the multidimensional nature of treatment and its effects, suggested schema, and comparisons of several outcome-assessment instruments. In addition, a bibliography on outcomes research in allied health was produced.     

The effects of opiate antagonism on gonadotropin secretion in children and in women with hypothalamic amenorrhea

The effects of opiate antagonism [naloxone infusion, 1 mg/(m2 X h)] on gonadotropin secretion were examined in four children (one female and three males: two late prepubertal and two pubertal; chronologic age, range 11.8-15.9 yr; bone age, range 8.5-13.5 yr) and in four women with hypothalamic amenorrhea (two at normal body weight and two at low body weight). Naloxone had no effect on daytime gonadotropin secretion in three children who were biologically the youngest in the group, two late prepubertal and one early pubertal [plasma luteinizing hormone (LH) means +/- SE: control day, 1.2 +/- 0.1; control night, 4.5 +/- 0.4; and naloxone day, 1.3 +/- 0.1 mIU/ml]. In contrast, opiate blockade produced a slight but discernible increase in plasma LH in the child whose hypothalamic-pituitary-gonadal axis was the most mature, a boy at mid-puberty. Naloxone produced a striking increase in plasma LH in the amenorrheic women at normal body weight (LH, means +/- SE: control day, 3.4 +/- 0.3; control night, 7.0 +/- 1.0; and naloxone day, 7.4 +/- 0.7 mIU/ml) as well as in those at low body weight (LH, means +/- SE: control day, 3.5 +/- 0.3; control night, 2.8 +/- 0.2; naloxone day, 4.9 +/- 0.4; and naloxone night, 6.7 +/- 0.5 mIU/ml). Antagonism of endogenous opiate activity increased LH pulse frequency in all four women.(ABSTRACT TRUNCATED AT 250 WORDS)     

Risks to the public from historical releases of radionuclides and chemicals at the Rocky Flats Environmental Technology Site

This paper summarizes the methods and results of estimating risks of cancer incidence resulting from plutonium, carbon tetrachloride, and beryllium releases from operations at the Rocky Flats Environmental Technology Site, near Denver, Colorado, from 1953 through 1989. The key findings show that people who lived near the facility were exposed to plutonium mainly through inhalation during routine operations, from a major fire in 1957, and from plutonium resuspended from contaminated soil from an outdoor drum storage area, called the 903 Area. Results were presented for five exposure scenarios that were location-independent. Individuals described by the laborer scenario received the highest risk of all scenarios considered. Upper bound (95th percentile) incremental lifetime cancer incidence risks for the laborer scenario were in about the 10(-4) range (1 chance in 10,000) for developing cancer from Rocky Flats plutonium releases during a lifetime. At the 5th percentile level, the maximum cancer risk was about 10(-7) (1 chance in 10 million) for developing cancer during a lifetime. Estimated cancer risks at the 95th percentile level are within the range of for acceptable risks established by the US Environmental Protection Agency of 10(-6) to 10(-4). Carbon tetrachloride was found to be the chemical that presented the highest risk to the public. The 5th and 95th percentile risk values for exposure to carbon tetrachloride were 9.2x10(-7) and 2.5x10(-5), respectively.