微生物转化影响不同内源雌激素水平大鼠粪便雌马酚含量和菌群结构

雌马酚(Equol)是肠道中特定细菌转化大豆异黄酮的产物,与其前体大豆苷元(Daidzein)相比,雌马酚具有更强的生物学活性。【目的】研究口服雌马酚产生菌对大鼠转化大豆苷元能力的可能促进作用及内源雌激素对大鼠肠道菌群的可能影响。【方法】使用平均体重为211±9g的卵巢摘除和假手术雌性大鼠各30只,分别随机分为5组,并灌胃蒸馏水、雌二醇、大豆苷元、雌马酚和大豆苷元+雌马酚产生菌ZX7。【结果】从灌胃第2天开始,接受大豆苷元后大鼠粪样中始终具有较高水平的雌马酚,显著高于对照和雌二醇组(P<0.01);灌胃大豆苷元+雌马酚产生菌ZX7的大鼠和直接灌胃雌马酚的大鼠在粪样雌马酚含量上十分接近;DGGE图谱的PCA分析显示,卵巢摘除大鼠和假手术大鼠粪便菌群存在明显差异;大鼠粪便拟杆菌门细菌数量与粪样中雌马酚水平显著正相关。【结论】大鼠肠道固有菌群中可能存在能够将大豆苷元转化为雌马酚的细菌,利用外源菌株改变大鼠雌马酚产生能力具有一定的可行性,不同的内源雌激素水平可能影响大鼠肠道菌群结构,拟杆菌门细菌可能在大豆苷元的生物转化过程中起着十分重要的作用。     

(+/−)-Alashanoid N,Two Enantiomeric Sesquiterpenes from Syringa pinnatifolia

Two enantiomeric humulane sesquiterpenes, namely (+)-alashanoid N ( 1a ) and (−)-alashanoid N ( 1b ), along with two known analogs ((2R,3R,5R)-2,3-epoxy-6,9-humuladien-5-ol-8-one ( 2 ) and (2R,3S,5R)-2,3-epoxy-6,9-humuladien-5-ol-8-one ( 3 )), were described from the peeled stems of a folk Mongolian herbal medicine Syringa pinnatifolia. Their structures were characterized based on UV, IR, NMR, and HR-ESI-MS data analyses, and the absolute configurations were determined by data analysis of X-ray diffraction and quantum chemical calculations. (+/−)-Alashanoid N showed inhibition against NO production in RAW 264.7 macrophage cells with IC₅₀ values of 90.1 μM and 71.7 μM, and protective effect against oxygen-glucose deprivation injury to H9c2 cells at a concentration of 20 μM and 5 μM, respectively.     

Does obstructive sleep apnea correlate with Epworth Sleepiness Scale in an Indian population?

Sleep and Biological Rhythms - Various demographic and clinical predictors attributing to the severity of obstructive sleep apnea (OSA) in Indian subjects have not been extensively studied....     

Epibiotic bacteria associated with the recently discovered Yeti crab, Kiwa hirsuta

The Yeti crab, Kiwa hirsuta Macpherson et al., is the single known species in a recently discovered crab family Kiwaidae (Decapoda: Galatheoidea) from deep-sea hydrothermal vents. Its chelipeds, walking legs and the ventral surface of its cephalothorax are covered with dense setae that, in turn, are covered with clusters of filamentous bacteria, making the crab appear extraordinarily 'hairy'. Electron microscopy revealed dense bacterial clusters attached to the chitinous outer layer of the setae. Molecular phylogenetic analyses revealed the setae-associated bacteria to be dominated by epsilon-Proteobacteria ( approximately 56% of the recovered ribotypes), gamma-Proteobacteria ( approximately 25%) and Bacteroidetes ( approximately 10%). Fluorescence in situ microscopy confirmed the attachment of filamentous epsilon-Proteobacteria on setae, but no specialized morphological structures appeared to exist for bacterial attachment. Key enzymes involved in the reductive tricarboxylic acid cycle (ATP-dependent citrate lyase) and sulfite oxidation or dissimilatory sulfate reduction (bidirectional APS reductase) were detected. Consequently, the potential for carbon fixation and cycling of reduced and oxidized sulfur appear to exist in the dense microflora that grows on the crab's setae.     

Allometry of paracellular absorption in birds

Water-soluble nutrients can be absorbed across the intestinal epithelium by transcellular and paracellular processes. Recent studies suggest that small birds (<180 g) have more extensive paracellular absorption of glucose than nonflying mammals. This may be a feature that compensates for a reduced small intestine size because small birds have smaller mass-corrected intestinal length than do nonflying mammals, but the difference diminishes in larger birds. We hypothesized that if this explanation were correct, there would be a negative correlation between paracellular absorption and body mass in birds and that larger birds would have paracellular absorption comparable to that of nonflying mammals. We tested this hypothesis, using consistent methodology, by measuring the extent of absorption of a series of inert carbohydrate probes in heavier bird species (>300 g) selected from diverse taxa: American coots, mallards, pheasants, and pigeons. Absorption of carbohydrate probes was inversely related to body mass in birds, and absorption of these probes in large birds (>500 g) was comparable to absorption measurements in nonflying mammals. Higher paracellular uptake in the smaller avian species may offer a physiologically inexpensive means of nutrient absorption to compensate for a reduced small intestine size but may make those species more vulnerable to toxicant absorption.     

Color change and pigmentation in a color polymorphic cichlid fish

Hydrobiologia - In many haplochromine cichlids, body coloration is an important communication cue during social interactions. In some cichlids, individuals can change color, but we have little...     

Exercise and diet induced weight loss improves measures of oxidative stress and insulin sensitivity in adults with characteristics of the metabolic syndrome

Obesity and insulin resistance (IR) increase the risk for coronary heart disease; however, much of this risk is not attributable to traditional risk factors. We sought to determine whether weight loss associated with supervised aerobic exercise beneficially alters biomarkers of oxidative stress and whether these alterations are associated with improvements in measures of insulin resistance. Twenty-five sedentary and overweight to obese [body mass index (BMI) = 33.0 +/- 0.8 kg/m(2)] individuals, with characteristics of the metabolic syndrome, participated in a 4- to 7-mo weight loss program that consisted of energy restriction (reduced by approximately 500 kcal/day) and supervised aerobic exercise (5 days/wk, 45 min/day at 60% Vo(2 max); approximately 375 kcal/day). IR and insulin sensitivity were assessed by the calculation of the homeostasis model assessment (HOMA) and quantitative insulin sensitivity check index (QUICKI), respectively. Oxidative stress was assessed by oxidized LDL (oxLDL), myeloperoxidase (MPO), and low- and high- density lipoprotein (LDL and HDL) lipid hydroperoxide concentrations in serum. Indexes for antioxidative status included apolipoprotein A1 (apoA1) concentrations and paraoxonase-1 (PON1) activity and protein concentrations. Exercise- and diet-induced weight loss ( approximately 10%) significantly (P < 0.05) increased insulin sensitivity and reduced IR, oxLDL, and LDL lipid hydroperoxides but did not alter HDL lipid hydroperoxides or MPO concentrations. Lifestyle modification impacted systemic antioxidative status by increasing apoA1 concentrations and reducing serum PON1 protein and activity. Changes in oxidative stress were not associated with alterations in HOMA or QUICKI. Diet- and exercise-induced weight loss ( approximately 10%) improves measures of insulin sensitivity and beneficially alters biomarkers of oxidative status.     

Psychosocial impact of genetic testing for hemochromatosis in the HEIRS Study: a comparison of participants recruited in Canada and in the United States

The Hemochromatosis and Iron Overload Screening (HEIRS) Study screened 101,168 participants recruited from primary-care clinics in Canada and the United States. The present study investigated differences in the psychological effects of genetic screening for hemochromatosis (HFE mutation analysis) in participants from each country. Study participants comprised a subset of 2,654 individuals who donated blood for HFE mutation analysis. The initial screening and 1-month post-result questionnaires included measures of General Health, Mental Health (SF-36), and a measure of the percentage of individuals who experienced at least one example of worry in response to the genetic testing. Participants reported similar changes in general health and mental health, regardless of mutation result, or country. Although a significantly lower percentage of Canadian participants than U.S. participants indicated at least one negative emotional response to the genetic testing, greater than 50% of C282Y homozygote participants (the gene mutation most strongly associated with hemochromatosis) from both countries experienced such in response to testing. Thus, although not serious enough to affect individuals' mental or physical health, there was evidence of at least one element of negative emotional response to the genetic testing. These findings suggest that population screening for common HFE mutations associated with hemochromatosis risk has similar psychological effects on Canadian and U.S. individuals, although fewer Canadians may experience a negative response to such testing.