Capillary electrophoresis with (R)-(--)-N-(3,5-dinitrobenzoyl)-alpha-phenylglycine as chiral selector for separation of albendazole sulfoxide enantiomers and their analysis in human plasma.

The electrokinetic separation and analysis of the enantiomers of albendazole sulfoxide (ABZSO), a sulfoxide with a sulfur stereogenic center hepatically formed during therapy with the anthelmintic drug albendazole (ABZ), is reported. Using aqueous or nonaqueous alkaline background electrolytes, ABZSO enantiomers cannot be separated via single use of common neutral cyclodextrins and negatively charged carboxymethyl-beta-cyclodextrin. With the Pirkle-type (R)-(-)-N-(3,5-dinitrobenzoyl)-alpha-phenylglycine ((R)-DNBPG) chiral selector, however, ABZSO enantiomers do separate within a borate background electrolyte of pH 9.0-9.5 and can be detected by UV absorbance at 295 nm. Having untreated fused-silica capillaries and 50 mM (R)-DNBPG, enantiomeric resolution is dependent on capillary i.d., capillary length and operational temperature. Optimized separation is obtained for pH 9.25 and the lowest temperature setting. Preliminary data indicate that the same approach could be employed for analysis of the enantiomers of oxfenbendazole, a chiral anthelmintic sulfoxide employed in veterinary pharmacotherapy. Analysis of plasma extracts of patients under ABZ pharmacotherapy confirmed the known enantioselectivity in the sulfoxidation of ABZ with the (+)-ABZSO being the predominant enantiomer in blood. Commencing with 2 ml of plasma, enantiomers present at >1 microg/ml could be detected only, a limitation which is based upon the strong absorbance of the chiral selector. (R)-DNBPG and ABZSO are negatively charged at pH 9.0-9.5, which prevents the application of a partial filling technique. The mobility of (R)-DNBPG is significantly larger compared to that of ABZSO. A migrating plug-plug approach based upon a plug of (R)-DNBPG migrating across the sample plug in an electroosmosis free environment obtained via a dynamic coating produced by spermine is shown to provide chiral resolution but not increased sensitivity.     

Comparison of cryopreservation outcome following intracytoplasmic sperm injection and conventional in vitro fertilization

Purpose Our purpose was to compare the success rate of transferring frozen-thawed embryos generated from either intracytoplasmic sperm injection (ICSI) or conventional in vitro fertilization (IVF). Methods A retrospective review of all frozen—thawed embryo transfer (ET) cycles between January 1995 and April 1997 was performed. There were 83 and 204 transfer cycles of frozen — thawed multicellular embryos generated from conventional IVF (group A) and ICSI (group B), respectively. The survival rate of frozen — thawed embryos and the outcome following ET in both groups were assessed. Results The groups did not differ in age (31.7±4.6 and 30.6±6.0; mean±SD) or number of embryos transferred (3.5±1.1 and 3.8±1.3 for groups A and B, respectively). An acceptable pregnancy rate per ET was achieved in both groups, but the rate was significantly higher (P = 0.04) for group A than group B, 32.5 and 20%, respectively. Group A included frozen embryos of a higher quality than those of group B, but the proportion of embryos surviving after thawing was significantly higher for group B than group A (92.5 and 85.6%, respectively; P = 0.0004). The abortion rate did not differ between the two groups: 22 and 26.8% for groups A and B, respectively. Conclusions Although an overall high pregnancy rate was achieved following frozen-thawed ET, it was lower for cycles in which embryos had been generated from ICSI. This difference may be attributed to a lower prefreezing embryo quality in the ICSI group. Embryos originating from ICSI were not vulnerable to cryopreservation and, when implanted, resulted in a comparable abortion rate to thawed embryos of conventional IVF.     

Genetic sequence variations and <Emphasis Type="Italic">ADPRT</Emphasis> haplotype analysis in French Canadian families with high risk of breast cancer

The poly(ADP-ribose) polymerase (PARP/ADPRT) protein family catalyzes the synthesis of cellular poly(ADP-ribose) following DNA damage and is involved in genomic integrity by regulating cellular responses to DNA damage and apoptosis. Moreover, ADPRT inhibition contributes to a protective effect against cancer development. These findings render ADPRT an attractive candidate susceptibility gene for breast cancer, and thus the goal of this study was to evaluate the possible involvement of ADPRT sequence variations in breast cancer susceptibility. The complete sequence of the 23 exons and flanking intronic sequences of the ADPRT gene was analyzed in 54 affected individuals from distinct high-risk non-BRCA1/2 French Canadian families. No deleterious truncating mutation was identified in the coding region. However, 34 sequence variations were identified, among which seven are coding variants and seven are novel changes. All coding variants and intronic changes located in the vicinity of the coding variants identified in the case series were also analyzed in a cohort of 73 unrelated healthy French Canadian individuals. Interestingly, one missense variant (Pro377Ser) was observed in three different breast cancer cases but was not present among unaffected individuals. We have conducted here an exhaustive detailed mutation and haplotype tagging analysis of the ADPRT gene with regard to breast cancer, providing useful data for other large-scale association studies. Additional studies in other cohorts and other populations are however needed to further evaluate the implication of the Pro377Ser missense variant with regard to breast cancer susceptibility. Other members of INHERIT BRCAs involved in clinical aspects of the study are listed in the Appendix. J. Simard holds a Canada Research Chair in Oncogenetics.     

Effects of indomethacin on systemic and renal haemodynamics in conscious lambs

Both prostaglandins (PGs) PGE(2) and PGI(2) can act as renal vasodilators, these effects being exacerbated when the renin-angiotensin system is activated. Therefore, we hypothesized that PGs would play a more predominant role in modulating renal haemodynamics in the newborn period, when the renin-angiotensin system is activated. To this end, the role of endogenously produced PGs in modulating systemic and renal haemodynamics was investigated in two groups of conscious lambs aged approximately 1 and approximately 6 weeks. Arterial pressure, venous pressure and renal blood flow were measured for 5 min before (control) and for 20 min after intravenous injection of vehicle (experiment 1). Twenty-four hours later, this protocol was repeated with intravenous injection of the non-selective cyclo-oxygenase inhibitor indomethacin (1 mg kg(-1), experiment 2). Heart rate was calculated from the systolic peak of the arterial pressure waveform, and renal vascular resistance (RVR) was calculated from the measured variables. In response to indomethacin but not vehicle, in both age groups of lambs there was an increase in mean arterial pressure and pulse interval, as well as a marked increase in RVR. These responses to indomethacin were, however, transient, with baseline levels being resumed within minutes. Although the hypothesis that PGs play a greater role in modulating renal haemodynamics early in life is not supported, these data do provide evidence that endogenously produced PGs modulate systemic and renal haemodynamics during postnatal maturation. It is apparent, however, that other vasoactive factors must be rapidly recruited in order to buffer the circulatory responses to removal of vasodilatory PGs in the developing newborn.     

Supplementation with calcium + vitamin D enhances the beneficial effect of weight loss on plasma lipid and lipoprotein concentrations

BACKGROUND: Adequate calcium intake can have a favorable effect on some metabolic variables. OBJECTIVE: The objective of the study was to determine the effects of daily calcium intake and of supplementation with calcium and vitamin D (calcium+D) during a weight-loss intervention on blood pressures, plasma lipid and lipoprotein concentrations, and glucose and insulin concentrations in low calcium consumers. DESIGN: Healthy, overweight or obese women (n = 63) with a daily calcium intake of < 800 mg/d were randomly assigned in a double-blind manner to 1 of 2 groups: the group consuming 2 tablets/d of a calcium + vitamin D supplement (600 mg elemental calcium and 200 IU vitamin D/tablet) or the group consuming placebo; both groups observed a 700 kcal/d energy restriction. These 63 women then completed a 15-wk weight-loss intervention. RESULTS: Initial daily calcium intake was significantly correlated with plasma HDL cholesterol (r = 0.41, P < 0.001) and with 2-h postload glycemia (r = -0.29, P < 0.05) during an oral-glucose-tolerance test, independent of fat mass and waist circumference. After the 15-wk intervention, significantly greater decreases in total:LDL and LDL:HDL (P < 0.01 for both) and of LDL cholesterol (P < 0.05) were observed in the calcium+D group than in the placebo group. The differences in total:HDL and LDL:HDL were independent of changes in fat mass and in waist circumference. A tendency for more beneficial changes in HDL cholesterol, triacylglycerol, and total cholesterol was also observed in the calcium+D group (P = 0.08). CONCLUSION: Consumption of calcium+D during a weight-loss intervention enhanced the beneficial effect of body weight loss on the lipid and lipoprotein profile in overweight or obese women with usual low daily calcium intake.     

Cause-specific mortality in the unionized U.S. trucking industry

BACKGROUND: Occupational and population-based studies have related exposure to fine particulate air pollution, and specifically particulate matter from vehicle exhausts, to cardiovascular diseases and lung cancer. OBJECTIVES: We have established a large retrospective cohort to assess mortality in the unionized U.S. trucking industry. To provide insight into mortality patterns associated with job-specific exposures, we examined rates of cause-specific mortality compared with the general U.S. population. METHODS: We used records from four national trucking companies to identify 54,319 male employees employed in 1985. Cause-specific mortality was assessed through 2000 using the National Death Index. Expected numbers of all and cause-specific deaths were calculated stratifying by race, 10-year age group, and calendar period using U.S. national reference rates. Standardized mortality ratios (SMRs) and 95% confidence intervals (CIs) were calculated for the entire cohort and by job title. RESULTS: As expected in a working population, we found a deficit in overall and all-cancer mortality, likely due to the healthy worker effect. In contrast, compared with the general U.S. population, we observed elevated rates for lung cancer, ischemic heart disease, and transport-related accidents. Lung cancer rates were elevated among all drivers (SMR = 1.10; 95% CI, 1.02-1.19) and dockworkers (SMR = 1.10; 95% CI, 0.94-1.30); ischemic heart disease was also elevated among these groups of workers [drivers, SMR = 1.49 (95% CI, 1.40-1.59); dockworkers, SMR = 1.32 (95% CI, 1.15-1.52)], as well as among shop workers (SMR = 1.34; 95% CI, 1.05-1.72). CONCLUSIONS: In this detailed assessment of specific job categories in the U.S. trucking industry, we found an excess of mortality due to lung cancer and ischemic heart disease, particularly among drivers.     

Nutritional status of the adult population in Niterói, Rio de Janeiro, Brazil: the nutrition, physical activity, and health survey

A household survey was conducted to assess the nutritional status of the adult population in Niterói, Rio de Janeiro, Brazil. In the selected households, all adults (>or= 20 years) had their body mass and stature measured. Body mass index (BMI) was used to determine the nutritional status according to the World Health Organization classification. The population estimates showed low prevalence of underweight (BMI < 18.5kg/m(2)), while 45.8% of women and 49.6% of men were overweight/obese (BMI >or= 25kg/m(2)). Obesity prevalence varied from 5.6% to 19.3% in men and from 9.6% to 21.3% in women, according to age. The prevalence of overweight/obesity was not associated with income (in either men and women) or schooling (in men), but there was an inverse relationship between schooling and overweight/obesity in women. The prevalence of underweight decreased with increasing mean income in the census enumeration area. The authors conclude that overweight/obesity is the most prevalent nutritional disorder in both men and women in Niterói. This pattern resembles recent results for the adult population in Southeast Brazil as a whole, where Niterói is located.     

Deciding to resuscitate extremely premature babies: How do parents and neonatologists engage in the decision?

Parents at risk of delivering a baby at the threshold of viability are faced with a critical decision. When a child is born between 23 and 25 weeks of gestation, parents are asked to decide whether or not to resuscitate their child. In essence, they are faced with a choice between life and death. We conducted a qualitative study to explore how parents and neonatologists engage in decision-making in a context of imminent and unplanned delivery at the threshold of viability. Twelve parents and attending neonatologists in a specialized tertiary care centre in Montreal, Canada were separately interviewed immediately following neonatal consultation. Results highlight how neonatologists and parents engage in decision making from different standpoints: while neonatologists focus on the management of the unborn baby, parents have yet to fully conceptualize their infant as a distinct entity since they are in a process of grieving their pregnancy and their parenthood project. Moreover, in their attempt to ensure an informed decision, neonatologists adopt either of two models through provision of the most up-to-date and objective information available: "remaining as neutral as possible to allow parents to make their own decision", or, "formulating a proposal to which parents can choose or not to assent". Overall, if the provided information fits parents' expectations, they tend to feel confident with their decision. However, if it does not take their experience into account, their decision is experienced as a solitary process. Parents express the need to receive more than just factual information from neonatologists. They also require support and engagement from caregivers to manage the uncertainty. This brings into question the traditional concept of neutral informed consent and suggests the necessity of a shared decision-making model to ensure that the decision to resuscitate extremely premature babies, at the limits of viability, becomes a truly ethical task.     

alpha v beta3-dependent cross-presentation of matrix metalloproteinase-2 by melanoma cells gives rise to a new tumor antigen

A large array of antigens that are recognized by tumor-specific T cells has been identified and shown to be generated through various processes. We describe a new mechanism underlying T cell recognition of melanoma cells, which involves the generation of a major histocompatibility complex class I-restricted epitope after tumor-mediated uptake and processing of an extracellular protein--a process referred to as cross-presentation-which is believed to be restricted to immune cells. We show that melanoma cells cross-present, in an alpha v beta3-dependent manner, an antigen derived from secreted matrix metalloproteinase-2 (MMP-2) to human leukocyte antigen A*0201-restricted T cells. Because MMP-2 activity is critical for melanoma progression, the MMP-2 peptide should be cross-presented by most progressing melanomas and represents a unique antigen for vaccine therapy of these tumors.