Plasma organochlorine concentrations and bone ultrasound measurements: a cross-sectional study in peri-and postmenopausal Inuit women from Greenland

Background  

Inuit women are highly exposed through their traditional seafood based diet to organochlorine compounds, some of them displaying endocrine disrupting properties. We hypothesized that this exposure might be related to bone characteristics that are altered in osteoporosis, because hormone deficiency is a known risk factor for the disease.     

Pure-tone threshold description of an elderly French screened population.

OBJECTIVES: To describe the distribution of pure-tone hearing thresholds of a Caucasian population living in the south of France aged 70 years and older. To establish age- and sex-adjusted normative hearing thresholds based on results of subjects free of noise and ototoxic drug exposure and to compare them with hearing thresholds of exposed (E) subjects. DESIGN: Cross-sectional analysis of a longitudinal epidemiologic cohort study. SETTING: Montpellier suburb, south of France. PARTICIPANTS: A total of 778 subjects 70 years old and older were examined. Noise exposure, ototoxic medication use, and medical history were collected. Hearing thresholds were obtained via pure-tone audiometry. After excluding patients with ear-related disease, 659 subjects were further analyzed (270 men and 389 women). Noise or ototoxic medication exposure was found in 364 subjects (E subjects), whereas 295 had no exposure (nonexposed [NE] subjects). METHODS: Median pure-tone thresholds, lower deviation, and upper deviation were calculated for the NE subjects with a statistical method similar to the ISO 7029 norm and were compared with thresholds of E subjects. RESULTS: Hearing thresholds, especially in high frequencies, increased with age more for women than for men. Median thresholds of E subjects were significantly higher than those for the NE sample in men. CONCLUSION: Age- and sex-adjusted hearing thresholds could well be useful in the study of the impact of environmental and genetic factors on hearing loss in the elderly. The next step would be to quantify the impact of noise, ototoxic drug exposure, and genetics using these age- and sex-adjusted thresholds.     

Tensions superficielles de copolymères méthacryliques perfluoroalkylés

The surface properties of methacrylic copolymers with a random distribution of perfluoroalkyl pendent groups were studied by a tensiometric method and were found to depend on the concentration of fluorinated units (2-hydroxy-4,4,5,5,6,6,7,7,8,8,9,9,9-tridecafluorononyl methacrylate ( 1 )), and the nature of the non-fluorinated methacrylic ester (methyl, butyl, stearyl). The surface tensions estimated by various approaches (critical surface tension, geometric and harmonic mean approximations) are very low (11 mN · m^?1 < y < 12 mN · m^?1). The surface tension of the copolymers drops drastically when a few percent of fluorinated units are incorporated into the polymeric chain. The wetting hysteresis, observed particularly in the case of water, could be due to the mobility of macromolecular chains at the interface, leading to a reorganization of fluorinated groups in order to minimize the interfacial energy.     

Utilizing prognostic and predictive factors in breast cancer

Opinion statement In order to make optimal treatment recommendations for patients with early-stage breast cancer, it is essential to accurately determine the patient’s underlying risk of disease recurrence and choose a therapy to which the individual is most likely to respond. Lymph node status, tumor size, histopathologic features including tumor type and grade, and hormone receptor status are well-accepted prognostic factors related to breast cancer. In addition, hormone receptor status is a very strong predictor of response to hormonal therapy. However, our currently accepted prognostic and predictive factors fall short and there is a critical need to more accurately identify those most likely to require or benefit from particular therapies. Attention has therefore focused on the determination of novel prognostic and predictive factors. The most promising new factor is the level of urokinase plasminogen activator and its inhibitor plasminogen activator inhibitor. Other putative factors include proliferative rate, the presence of lymphatic or vascular invasion, human epidermal growth factor receptor 2 (HER-2/neu or erbB-2) positivity, the presence of micrometastases in lymph nodes or bone marrow, and gene expression profile by microarray analysis, and by RNA-based methodology. Data regarding potential new prognostic factors are constantly emerging. These studies are frequently challenging to interpret as they are often retrospective, based on relatively small numbers of patients, include a mix of treated and untreated women, and often do not control for other known prognostic factors. Therefore, new data must be interpreted with caution.     

Antidepressant-like effects of agomelatine,melatonin and the NK<Subscript>1</Subscript> receptor antagonist GR205171 in impulsive-related behaviour in rats

Rationale Substance P receptor [neurokinin₁ (NK₁-R)] antagonists and melatonin_1/2 receptor (MT_1/2-R) agonists have been claimed to be potential antidepressants (ADs). In animals, these compounds are active in validated models responsive to ADs, such as forced swimming test and chronic mild stress paradigms. Classical AD drugs are also known to be effective in pathologies characterized by an impulse control deficiency. In line with this clinical observation, previous studies demonstrated that classical ADs increased the capacity to wait for food reward in rats subjected to a paradigm aimed at assessing impulsive-related behaviour. Objectives This study was conducted to investigate the effects of two MT_1/2-R agonists, melatonin and agomelatine, and a NK₁-R antagonist, GR205171, on tolerance to delay of food reward in rats. Methods Fasting rats were trained in a T-maze and allowed to choose between two magnitudes of reward: immediate but small reward (two pellets) vs 25-s delayed but large reward (ten pellets). Under this alternative, vehicle-injected rats selected the large-but-delayed reinforcer in less than 40% of the trials. Results Like the established ADs clomipramine (8 mg kg⁻¹, i.p.) and fluvoxamine (4 mg kg⁻¹, i.p.), melatonin (3 and 10 mg kg⁻¹, i.p.), agomelatine (10 and 30 mg kg⁻¹, i.p.) and GR205171 (30 mg kg⁻¹ but not 10 mg kg⁻¹, s.c.) significantly increased the number of choices of the large-but-delayed reward. The effect of melatonin (3 mg kg⁻¹, i.p.) was not counteracted by the MT_1/2-R antagonist S22153 (40 mg kg⁻¹, i.p.) that exerted no effect on its own. Conclusion These results suggest that MT_1/2-R agonists and NK₁-R antagonists enhance rats' tolerance to delay of gratification, an effect which may reflect their ability to improve impulse control. Further investigations are necessary to clarify the neurobiological mechanisms responsible for this effect.     

Polyphenol levels in human urine after intake of six different polyphenol-rich beverages

Dietary polyphenols are suggested to participate in the prevention of CVD and cancer. It is essential for epidemiological studies to be able to compare intake of the main dietary polyphenols in populations. The present paper describes a fast method suitable for the analysis of polyphenols in urine, selected as potential biomarkers of intake. This method is applied to the estimation of polyphenol recovery after ingestion of six different polyphenol-rich beverages. Fifteen polyphenols including mammalian lignans (enterodiol and enterolactone), several phenolic acids (chlorogenic, caffeic, m-coumaric, gallic, and 4-O-methylgallic acids), phloretin and various flavonoids (catechin, epicatechin, quercetin, isorhamnetin, kaempferol, hesperetin, and naringenin) were simultaneously quantified in human urine by HPLC coupled with electrospray ionisation mass-MS (HPLC-electrospray-tandem mass spectrometry) with a run time of 6 min per sample. The method has been validated with regard to linearity, precision, and accuracy in intra- and inter-day assays. It was applied to urine samples collected from nine volunteers in the 24 h following consumption of either green tea, a grape-skin extract, cocoa beverage, coffee, grapefruit juice or orange juice. Levels of urinary excretion suggest that chlorogenic acid, gallic acid, epicatechin, naringenin or hesperetin could be used as specific biomarkers to evaluate the consumption of coffee, wine, tea or cocoa, and citrus juices respectively.     

Decreased plasma endothelin-1 levels in children with sickle cell disease treated with hydroxyurea

Plasma endothelin-1 (ET-1) is elevated in patients with sickle cell disease (SCD). Hydroxyurea (HU) is the only drug with demonstrated clinical efficacy in SCD. Here we show that treatment with HU results in a decreased concentration of circulating ET-1 which is not correlated with the HU-induced increase in HbF level. Blunting of the ET-1 vasoconstrictive stimulus could contribute to the beneficial effects of HU.