Chlorinity determination in estuarine waters by physical measurement

The differential refractometer has been used as an effective instrument for chlorinity determination. Results obtained through its application have been compared with those derived from the use of less sensitive refractometers and with those obtained from specific conductivity measurements. The advantages of differential refractive-index measurements when applied to water in an estuarial brackish marsh basin are demonstrated...

The OECD Program to Validate the Rat Hershberger Bioassay to Screen Compounds for in Vivo Androgen and Antiandrogen Responses: Phase 2 Dose–Response Studies

OBJECTIVE: The Organisation for Economic Co-operation and Development (OECD) has completed phase 2 of an international program to validate the rodent Hershberger bioassay. DESIGN: The Hershberger bioassay is designed to identify suspected androgens and antiandrogens based on changes in the weights of five androgen-responsive tissues (ventral prostate, paired seminal vesicles and coagulating glands, the levator ani and bulbocavernosus muscles, the glans penis, and paired Cowper’s or bulbourethral glands). Protocol sensitivity and reproducibility were tested using two androgen agonists (17α-methyl testosterone and 17β-trenbolone), four antagonists [procymi-done, vinclozolin, linuron, and 1,1-dichoro-2,2-bis-(p-chlorophenyl)ethylene (p,p’-DDE)], and a 5α-reductase inhibitor (finasteride). Sixteen laboratories from seven countries participated in phase 2. RESULTS: In 40 of 41 studies, the laboratories successfully detected substance-related weight changes in one or more tissues. The one exception was with the weakest antiandrogen, linuron, in a laboratory with reduced sensitivity because of high coefficients of variation in all tissue weights. The protocols performed well under different experimental conditions (e.g., strain, diet, housing protocol, bedding, vehicle). There was good agreement and reproducibility among laboratories with regard to the lowest dose inducing significant effects on tissue weights. CONCLUSIONS: The results show that the OECD Hershberger bioassay protocol is reproducible and transferable across laboratories with androgen agonists, weak androgen antagonists, and a 5α-reductase inhibitor. The next validation phase will employ coded test substances, including positive substances and negative substances having no androgenic or antiandrogenic activity

Overexpression of grappa encoding a histone methyltransferase enhances stress resistance in Drosophila

Histone deacetylases, such as silent information regulator 2 (Sir2) and Rpd3 are involved in chromatin silencing and implicated in lifespan determination in several organisms. The yeast Dot1 gene encoding a histone methyltransferase affects localization of silencing proteins including Sir2, and plays an essential role in the repair of damaged DNA. However, it is not known whether an alteration of a histone methyltransferase activity influences lifespan or stress resistance, which is often associated with extended lifespan. Here we investigated whether the Drosophilagrappa (gpp) gene, a Dot1 homolog influences lifespan and stress resistance using transgenic flies overexpressing gpp and those bearing a partial loss-of-function mutation. Overexpression of gpp throughout the adult stage did not extend the lifespan, but significantly enhanced resistances when they were kept on medium containing 1% H(2)O(2), or those with poor nutrients. As well, gpp-overexpressing flies were behaviourally more active than control flies. We investigated whether gpp overexpression induced anti-oxidant genes, Catalase, Sod, Sod2, GstD2, dhd, TrxT and Trx-2. However, none of these genes was induced. A partial loss-of-function mutations in gpp dramatically reduced the lifespan under oxidative and caloric stresses. Taken together, these results demonstrated that gpp is required for normal lifespan and stress resistance, and that its overexpression increases stress resistance in Drosophila, without obvious induction of representative anti-oxidant genes

Assays to Detect β-Tubulin Codon 200 Polymorphism in Trichuris trichiura and Ascaris lumbricoides

The soil-transmitted helminths Ascaris lumbricoides and Trichuris trichiura are gastrointestinal nematodes causing many disabilities in tropical parts of the developing world. Control programs, such as “The Focussing Resources on Effective School Health” (FRESH) Partnership, have been implemented to remove human soil-transmitted nematodes through large-scale use of benzimidazole anthelmintic drugs for school-aged children in developing countries. The benzimidazole drugs albendazole and mebendazole are commonly used as a single annual treatment in areas where the burden is high. In veterinary nematodes, repeated use of these anthelmintics has selected for resistant populations. Resistance to benzimidazoles is commonly associated with a single amino acid substitution from phenylalanine to tyrosine in the β-tubulin gene at position 200. In this study, we have developed pyrosequencing assays for codon 200 in A. lumbricoides and T. trichiura to screen for this single nucleotide polymorphism (SNP) in β-tubulin. The 200Tyr SNP was detected at low frequency in T. trichiura from non-treated people from Kenya and at high frequency in T. trichiura from treated people from Panama. The presence of the resistance-associated SNP may play a role in the sometimes low and variable efficacy of benzimidazole anthelmintics against T. trichiura

Women's Education Level, Maternal Health Facilities, Abortion Legislation and Maternal Deaths: A Natural Experiment in Chile from 1957 to 2007

The aim of this study was to assess the main factors related to maternal mortality reduction in large time series available in Chile in context of the United Nations' Millennium Development Goals (MDGs).Time series of maternal mortality ratio (MMR) from official data (National Institute of Statistics, 1957-2007) along with parallel time series of education years, income per capita, fertility rate (TFR), birth order, clean water, sanitary sewer, and delivery by skilled attendants were analysed using autoregressive models (ARIMA). Historical changes on the mortality trend including the effect of different educational and maternal health policies implemented in 1965, and legislation that prohibited abortion in 1989 were assessed utilizing segmented regression techniques.During the 50-year study period, the MMR decreased from 293.7 to 18.2/100,000 live births, a decrease of 93.8%. Women's education level modulated the effects of TFR, birth order, delivery by skilled attendants, clean water, and sanitary sewer access. In the fully adjusted model, for every additional year of maternal education there was a corresponding decrease in the MMR of 29.3/100,000 live births. A rapid phase of decline between 1965 and 1981 (-13.29/100,000 live births each year) and a slow phase between 1981 and 2007 (-1.59/100,000 live births each year) were identified. After abortion was prohibited, the MMR decreased from 41.3 to 12.7 per 100,000 live births (-69.2%). The slope of the MMR did not appear to be altered by the change in abortion law.Increasing education level appears to favourably impact the downward trend in the MMR, modulating other key factors such as access and utilization of maternal health facilities, changes in women's reproductive behaviour and improvements of the sanitary system. Consequently, different MDGs can act synergistically to improve maternal health. The reduction in the MMR is not related to the legal status of abortion

Consenso salud materna para Chile en el nuevo milenio

Contexto: Chile presenta una tendencia secular hacia una sostenida mejoría en los principales indicadores materno-infantiles. Su situación constituye una experiencia positiva a nivel de la región de Latino-América y el Caribe. Sin embargo, esta tendencia se ha estancado en los últimos diez años lo que produce una situación inestable y preocupante desde el punto de vista de la salud pública materna. Esto motiva una reunión de expertos a nivel nacional e internacional para proponer estrategias para el alto nivel político orientadas a alcanzar los Objetivos 4 y 5 del Milenio. Conclusión: Este documento de consenso sobre mortalidad materna, sugiere un enfrentamiento en dos ejes: primero, enfrentar la nueva realidad epidemiológica desde la etapa pre-concepcional, esto incluye considerar la alta prevalencia de obesidad, hipertensión arterial, diabetes, hiperlipidemias e hipotiroidismo en la población, y por otro lado reforzar la seguridad de la asistencia del embarazo, parto y puerperio en los lugares más alejados y más vulnerables del país. Es necesario focalizar las intervenciones en los grupos de mayor riesgo vital (edades extremas de la vida fértil y portadoras de enfermedades médico-quirúrgicas severas, que se reflejan en el aumento proporcional de las causas indirectas de muerte materna), reforzar las actividades de auditorías de mortalidad/near miss, así como controlar el aumento alarmante de la tasa de partos por cesáreas