Synthesis and Some Properties of Poly(Alkylene Phosphorothioate)s Prepared from the Corresponding Poly(Alkylene H-Phosphonate)s

Several high molecular weight poly(alkylene phosphorothioate)s were synthesized by reacting poly(H-phosphonate)s with sulfur. The molecular weight of the resulting polymers are similar to the respective starting poly(alkylene H-phosphonate)s indicating that during sulfurization process no chain degradation occurred. The structure of poly(alkylene phosphorothioate)s was confirmed by the analysis of 1H, 13C and 31P NMR spectra.

Lipid-modifying efficacy and tolerability of extended-release niacin/laropiprant in patients with primary hypercholesterolaemia or mixed dyslipidaemia

BACKGROUND

Improving lipids beyond low-density lipoprotein cholesterol (LDL-C) lowering with statin monotherapy may further reduce cardiovascular risk. Niacin has complementary lipid-modifying efficacy to statins and cardiovascular benefit, but is underutilised because of flushing, mediated primarily by prostaglandin D(2) (PGD(2)). Laropiprant (LRPT), a PGD(2) receptor (DP1) antagonist that reduces niacin-induced flushing has been combined with extended-release niacin (ERN) into a fixed-dose tablet.

METHODS AND RESULTS

Dyslipidaemic patients were randomised to ERN/LRPT 1 g (n = 800), ERN 1 g (n = 543) or placebo (n = 270) for 4 weeks. Doses were doubled (2 tablets/day; i.e. 2 g for active treatments) for 20 weeks. ERN/LRPT 2 g produced significant changes vs. placebo in LDL-C (-18.4%), high-density lipoprotein cholesterol (HDL-C; 20.0%), LDL-C:HDL-C (-31.2%), non-HDL-C (-19.8%), triglycerides (TG; -25.8%), apolipoprotein (Apo) B (-18.8%), Apo A-I (6.9%), total cholesterol (TC; -8.5%), TC:HDL-C (-23.1%) and lipoprotein(a) (-20.8%) across weeks 12-24. ERN/LRPT produced significantly less flushing than ERN during initiation (week 1) and maintenance (weeks 2-24) for all prespecified flushing end-points (incidence, intensity and discontinuation because of flushing). Except for flushing, ERN/LRPT had a safety/tolerability profile comparable with ERN.

CONCLUSION

Extended-release niacin/LRPT 2 g produced significant, durable improvements in multiple lipid/lipoprotein parameters. The improved tolerability of ERN/LRPT supports a simplified 1 g-->2 g dosing regimen of niacin, a therapy proven to reduce cardiovascular risk.

The socioeconomic characteristics of risky sexual behaviour among reproductive-age women in St Petersburg

AIMS

To examine the sexual behaviour of reproductive age women in St Petersburg and its variation according to socio-demographic characteristics.

METHODS

A cross-sectional survey with a self-administered questionnaire. A random sample of women aged 18-44 in two districts in St Petersburg in 2004 were invited to a woman's clinic to complete a questionnaire. Of those women who were contacted (n=1719), 67% completed the anonymous questionnaire either in a clinic or at home. Results were analyzed according to three age-groups (18-24, 25-34, 35-44 years). Predictive characteristics were studied by use of multivariate models.

RESULTS

Younger respondents had on average started sexual life much earlier than the oldest (mean age 17.6 and 19.7 years respectively). The use of contraception at first coitus had become more common for each consecutive generation, though 25% of women aged 18-25 used no contraception, and only 45% used reliable contraception at first intercourse. Around 16% of the women had had two or more sex partners during the previous year, 55% of the youngest and 43% of the oldest had used reliable contraceptive methods. Older women were less likely to use contraceptives in last intercourse. High personal income, having children and low education were related to early age at first intercourse. Being single (women over 24 years) or having high income (women in all ages) was correlated with having had multiple sexual partners.

CONCLUSIONS

In addition to youth, sexual education should be targeted to older women, many of whom practice risky sexual behaviour.

An oral selective M3 cholinergic receptor antagonist in COPD

Cholinergic antagonists have been used since the early 1900s as bronchodilators for chronic obstructive pulmonary disease (COPD). The present study investigated whether an oral muscarinic M3-selective anticholinergic agent (OrM3) would provide an improved therapeutic advantage compared with an inhaled anticholinergic agent in patients with COPD. A 6-week, multicentre, randomised, placebo- and active-controlled, parallel-group study was performed at 56 sites in the USA. In total, 412 male and female patients (aged 35-86 yrs) with a clinical history consistent with COPD were randomised to receive OrM3 0.5, 2, 3 or 4 mg orally once daily, ipratropium bromide 36 mug by inhalation four times daily or placebo. OrM3 demonstrated a significant dose-related improvement in serial forced expiratory volume in one second and a trend for dose-related improvement in patient-reported symptoms compared with placebo. However, at a dose that provided efficacy less than that of ipratropium, the incidence of dose-related, mechanism-based side-effects for OrM3 exceeded those observed for ipratropium. In patients with chronic obstructive pulmonary disease, the oral M3-selective agent did not offer a therapeutic advantage over inhaled ipratropium. These results do not support the hypothesis that high selectivity for muscarinic M3 receptors over airway neuronal M2 receptors will represent a more effective therapy than current inhaled anticholinergics in obstructive airway disease.

Interactions between simvastatin and troglitazone or pioglitazone in healthy subjects

Two randomized, two-period crossover studies were conducted to evaluate the effects of repeat oral dosing of troglitazone (Study I) and pioglitazone (Study II) on the pharmacokinetics of plasma HMG-CoA reductase inhibitors following multiple oral doses of simvastatin and of simvastatin on the plasma pharmacokinetics of troglitazone (Study I) in healthy subjects. In both studies, each subject received two treatments. Treatment A consisted of once-daily oral doses of troglitazone 400 mg (Study I) or pioglitazone 45 mg (Study II) for 24 days with coadministration of once-daily doses of simvastatin 40 mg (Study I) or 80 mg (Study II) on Days 15 through 24. Treatment B consisted of once-daily oral doses of simvastatin 40 mg (Study I) or 80 mg (Study II) for 10 days. In Study I, the area under the plasma concentration-time profiles (AUC) and maximum plasma concentrations (Cmax) of HMG-CoA reductase inhibitors in subjects who received both troglitazone and simvastatin were decreased modestly (by approximately 30% for Cmax and approximately 40% for AUC), but time to reach Cmax (tmax) did not change, as compared with those who received simvastatin alone. Simvastatin, administered orally as a 40 mg tablet daily for 10 days, did not affect the AUC or tmax (p > 0.5) but caused a small but clinically insignificant increase (approximately 25%) in Cmax for troglitazone. In Study II, pioglitazone, at the highest approved dose for clinical use, did not significantly alter any of the pharmacokinetic parameters (AUC, Cmax, and tmax) of simvastatin HMG-CoA reductase inhibitory activity. For all treatment regimens, side effects were mild and transient, suggesting that coadministration of simvastatin with either troglitazone or pioglitazone was well tolerated. The modest effect of troglitazone on simvastatin pharmacokinetics is in agreement with the suggestion that troglitazone is an inducer of CYP3A. The insignificant effect of simvastatin on troglitazone pharmacokinetics is consistent with the conclusion that simvastatin is not a significant inhibitor for drug-metabolizing enzymes. The lack of pharmacokinetic effect of pioglitazone on simvastatin supports the expectation that this combination may be used safely.

A novel approach to measuring circulating blood volume: the use of a hemoglobin-based oxygen carrier in a rabbit model

Hemoglobin-based oxygen carriers (HBOC) may be ideal for monitoring circulating plasma volume (CV-P) and circulating blood volume (CV-B). We used an HBOC (Hemoglobin glutamer-200 [bovine], Oxyglobin; Biopure, Cambridge, MA) as an indicator for relative CV-B in the rabbit model. Accuracy of the technique was determined by comparison with the Evans blue dye (EBD) dilution technique in 19 anesthetized female New Zealand rabbits weighing 2.0 to 10.6 kg. The measurements were performed at baseline, after hemorrhage (1/3 of CV-B), normovolemic hemodilution (replacement of 1/3 CV-B by Hextend; Abbot Laboratories, North Chicago, IL), and hypervolemic hemodilution (additional infusion of Hextend(R) in a volume equal to 1/3 of CV-B). Hemoglobin concentration was measured by using a HemoCue photometer (HemoCue AB, Angelholm, Sweden). EBD concentration was analyzed by using linear regression to estimate Time 0 concentration; Time 0 was defined as EBD injection time. The difference between CV-P values determined by EBD and HBOC dilution was independent from the magnitude of the CV-P value. The relative bias was 1.29 mL, and the precision (one SD) was 2.82 mL. The difference did not reach statistical significance.

IMPLICATIONS

Circulating plasma and blood volumes can be accurately estimated by plasma hemoglobin concentration measurements by using hemoglobin-based oxygen carrier infusion.

An application of an effective interdisciplinary health-focused cross-cultural collaboration

The phenomenon of cross-cultural collaboration is not new. What is lacking in the literature, however, is a discussion of how health professionals from various cultures, collaborating together, have addressed their patients' health care needs to improve their quality of life. Because of increased interest in global health issues, it seems logical that health professionals from various countries form collaborative partnerships to investigate and address these health issues. Although treatments to health problems are offered, it is not generally communicated in the literature how cross-cultural collaboration played a role in managing the process to solve the problem. By applying the concepts for global managers outlined by P. R. Harris and R. T. Moran (1996), this article describes how the investigators established a successful cross-cultural collaboration for conducting health research between teams in the United States and Russia.