Determination of some organochlorine compounds in herbal colouring agent henna (Lawsonia inermis) and in tea (Thea sinensis)

Henna (Lawsonia inermis) has been used for centuries as a herbal hair and skin dye, but very little is known about its additives and contaminants that could adversely affect human health. An analytical method was developed to determine organochlorine compounds in henna, as they are still widely used in the areas where henna is grown. Samples were sonicated with n-hexane, extracts cleansed on Florisil sorbent and analysed using gas chromatography with electron capture detection. The overall recoveries were 17-33 % with the extraction RSD 5-21%, while the levels of lindane (gamma-HCH), p,p'-DDT, and p,p'-DDE in henna samples were 7-157 microg kg(-1). The same procedure was successfully applied to analyse black tea samples for the same compounds, and which showed lower contamination.     

Multiple-marker screening in human immunodeficiency virus-positive pregnant women: Screen positivity rates with the triple and quad screens

OBJECTIVE: The study was undertaken to determine the screen-positive rates of multiple-marker screening tests in pregnant women who are positive for human immunodeficiency virus (HIV) at our institution for open neural tube defects and aneuploidy, for both triple (alpha-fetoprotein, human chorionic gonadotropin [hCG], unconjugated estriol) and quad (alpha-fetoprotein, hCG, unconjugated estriol, inhibin A) screens, and to compare these rates with a matched control group. STUDY DESIGN: A 1:1 matched case-control study was performed comparing multiple marker screening test results in 34 HIV-positive women with age- and race-matched HIV-negative controls. Individual serum markers and screen positive rates for both the triple and quad screens were compared among the cases and controls. RESULTS: In each group, there were 19 women with triple screens and 15 with quad screens. Serum hCG multiples of the median were significantly higher in the HIV-positive compared with the HIV-negative women (P=.033). There was no difference in screen positive rates between the cases and controls using the triple screen, but there was a significantly higher overall screen positive rate in the HIV-positive group when the quad screen was used (33% vs 7%, P=.046). CONCLUSION: There is a significantly higher rate of overall quad screen positivity on multiple-marker screening among HIV-positive women compared with a matched control group.     

Behavioral investigation of some possible effects of the central olivocochlear pathways in transgenic mice

This study investigated the auditory behaviors of transgenic mice with deletions of alpha9 nicotinic acetylcholine receptor subunits. In the normal mammalian cochlea, the mechanical properties of outer hair cells are modified by the release of acetylcholine from olivocochlear efferent terminals. Electrophysiological correlates of this efferent feedback have not been demonstrated in alpha9 knockout mice, presumably because they are mediated by alpha9 receptors. Previous studies have associated lesions of olivocochlear pathways with hearing impairments in background noise. The prediction that alpha9 knockout mice would show similar deficits was tested by collecting psychophysical thresholds for tone detection and intensity discrimination from knockout mice, within-strain control subjects, and CBA/CaJ mice. Comparable performance was observed for the subject groups in quiet and in continuous background noise. The preservation of auditory function in alpha9 knockout mice suggests that central efferent pathways work in combination with the peripheral olivocochlear system to enhance hearing in noise, and may compensate for profound manipulations of peripheral feedback in highly routine testing procedures. An intriguing possibility is that these central mechanisms include the brainstem collaterals of olivocochlear neurons since their post-synaptic targets do not express alpha9 receptors and therefore are likely to maintain their effects in alpha9 knockout mice.     

儿童癌症幸存者成年后的慢性疾病

由于治疗方法的进步,近80%的儿童和青少年癌症患者能够长期生存。在美国,约有270000例儿童癌症的幸存者,即每640名20至39岁成年人中就有一名幸存者。大量的幸存者有利于儿童癌症治疗后长期健康结果的研究。现在可以明确的是,化疗和放疗所致的儿童各器官系统损害在临床上可能潜伏多年。为了全面了解治疗儿童癌症而继发的健康问题,重要的是衡量三项长期结果:健康状况、死亡率和患病率。这三项中,关于前两项已有相当好的研究报道。在一项对20227例癌症5年生存者的回顾性分析中,Mertens等发现以下原因导致的超额死亡率具有统计学意义:继发癌症(…     

Mutations in Emery-Dreifuss muscular dystrophy and their effects on emerin protein expression

Seventeen families with Emery-Dreifuss muscular dystrophy (EDMD) have been studied both by DNA sequencing and by emerin protein expression. Fourteen had mutations in the X-linked emerin gene, while three showed evidence of autosomal inheritance. Twelve of the 14 emerin mutations caused early termination of translation. An in-frame deletion of six amino acids from the C-terminal transmembrane helix caused almost complete absence of emerin from muscle with no localization to the nuclear membrane, although mRNA levels were normal. This shows that mutant emerin proteins are unstable if they are unable to integrate into a membrane. A 22 bp deletion in the promoter region was expected to result in reduced emerin production, but normal amounts of emerin of normal size were found in leucocytes and lymphoblastoid cell lines. This shows that DNA analysis is necessary to exclude emerin mutations in suspected X-linked EDMD. Emerin levels in female carriers often deviated from the expected 50% and this was due, in at least two families, to skewed emerin mRNA expression from the normal and mutated alleles. In one family with a novel deletion of the last three exons of the emerin gene, a carrier had a cardiomyopathy and very low emerin levels (<5% of normal) due to skewed X-inactivation. In the three autosomal cases of EDMD, emerin was normal on western blots of blood cells, which suggests that autosomal EDMD is not caused by indirect reduction of emerin levels.      

World health system performance revisited: the impact of varying the relative importance of health system goals

Background

In 2002, the World Health Organization published a health system performance ranking for 191 member countries. The ranking was based on five indicators, with fixed weights common to all countries.

Methods

We investigate the feasibility and desirability of using mathematical programming techniques that allow weights to vary across countries to reflect their varying circumstances and objectives.

Results

By global distributional measures, scores and ranks are found to be not very sensitive to changes in weights, although differences can be large for individual countries.

Conclusions

Building the flexibility of variable weights into calculation of the performance index is a useful way to respond to the debates and criticisms appearing since publication of the ranking.