460 research outputs found

    Effects of dietary phytoestrogens on plasma testosterone and triiodothyronine (T3) levels in male goat kids

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    <p>Abstract</p> <p>Background</p> <p>Exposure to xenoestrogens in humans and animals has gained increasing attention due to the effects of these compounds on reproduction. The present study was undertaken to investigate the influence of low-dose dietary phytoestrogen exposure, i.e. a mixture of genistein, daidzein, biochanin A and formononetin, on the establishment of testosterone production during puberty in male goat kids.</p> <p>Methods</p> <p>Goat kids at the age of 3 months received either a standard diet or a diet supplemented with phytoestrogens (3 - 4 mg/kg/day) for ~3 months. Plasma testosterone and total and free triiodothyronine (T<sub>3</sub>) concentrations were determined weekly. Testicular levels of testosterone and cAMP were measured at the end of the experiment. Repeated measurement analysis of variance using the MIXED procedure on the generated averages, according to the Statistical Analysis System program package (Release 6.12, 1996, SAS Institute Inc., Cary, NC, USA) was carried out.</p> <p>Results</p> <p>No significant difference in plasma testosterone concentration between the groups was detected during the first 7 weeks. However, at the age of 5 months (i.e. October 1, week 8) phytoestrogen-treated animals showed significantly higher testosterone concentrations than control animals (37.5 nmol/l vs 19.1 nmol/l). This elevation was preceded by a rise in plasma total T<sub>3 </sub>that occurred on September 17 (week 6). A slightly higher concentration of free T<sub>3 </sub>was detected in the phytoestrogen group at the same time point, but it was not until October 8 and 15 (week 9 and 10) that a significant difference was found between the groups. At the termination of the experiment, testicular cAMP levels were significantly lower in goats fed a phytoestrogen-supplemented diet. Phytoestrogen-fed animals also had lower plasma and testicular testosterone concentrations, but these differences were not statistically significant.</p> <p>Conclusion</p> <p>Our findings suggest that phytoestrogens can stimulate testosterone synthesis during puberty in male goats by increasing the secretion of T<sub>3</sub>; a hormone known to stimulate Leydig cell steroidogenesis. It is possible that feedback signalling underlies the tendency towards decreased steroid production at the end of the experiment.</p

    Early versus deferred endovenous ablation of superficial venous reflux in patients with venous ulceration: the EVRA RCT

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    Background Venous ulceration is a common and costly health-care issue worldwide, with poor healing rates greatly affecting patient quality of life. Compression bandaging has been shown to improve healing rates and reduce recurrence, but does not address the underlying cause, which is often superficial venous reflux. Surgical correction of the reflux reduces ulcer recurrence; however, the effect of early endovenous ablation of superficial venous reflux on ulcer healing is unclear. Objectives To determine the clinical effectiveness and cost-effectiveness of compression therapy with early endovenous ablation of superficial venous reflux compared with compression therapy with deferred endovenous ablation in patients with venous ulceration. Design A pragmatic, two-arm, multicentre, parallel-group, open randomised controlled trial with a health economic evaluation. Setting Secondary care vascular centres in England. Participants Patients aged ≥ 18 years with a venous leg ulcer of between 6 weeks’ and 6 months’ duration and an ankle–brachial pressure index of ≥ 0.8 who could tolerate compression and were deemed suitable for endovenous ablation of superficial venous reflux. Interventions Participants were randomised 1 : 1 to either early ablation (compression therapy and superficial endovenous ablation within 2 weeks of randomisation) or deferred ablation (compression therapy followed by endovenous ablation once the ulcer had healed). Main outcome measures The primary outcome measure was time from randomisation to ulcer healing, confirmed by blinded assessment. Secondary outcomes included 24-week ulcer healing rates, ulcer-free time, clinical success (in addition to quality of life), costs and quality-adjusted life-years (QALYs). All analyses were performed on an intention-to-treat basis. Results A total of 450 participants were recruited (224 to early and 226 to deferred superficial endovenous ablation). Baseline characteristics were similar between the two groups. Time to ulcer healing was shorter in participants randomised to early superficial endovenous ablation than in those randomised to deferred ablation [hazard ratio 1.38, 95% confidence interval (CI) 1.13 to 1.68; p = 0.001]. Median time to ulcer healing was 56 (95% CI 49 to 66) days in the early ablation group and 82 (95% CI 69 to 92) days in the deferred ablation group. The ulcer healing rate at 24 weeks was 85.6% in the early ablation group, compared with 76.3% in the deferred ablation group. Median ulcer-free time was 306 [interquartile range (IQR) 240–328] days in the early ablation group and 278 (IQR 175–324) days in the deferred endovenous ablation group (p = 0.002). The most common complications of superficial endovenous ablation were pain and deep-vein thrombosis. Differences in repeated measures of Aberdeen Varicose Vein Questionnaire scores (p < 0.001), EuroQol-5 Dimensions index values (p = 0.03) and Short Form questionnaire-36 items body pain (p = 0.05) over the follow-up period were observed, in favour of early ablation. The mean difference in total costs between the early ablation and deferred ablation groups was £163 [standard error (SE) £318; p = 0.607]; however, there was a substantial and statistically significant gain in QALY over 1 year [mean difference between groups 0.041 (SE 0.017) QALYs; p = 0.017]. The incremental cost-effectiveness ratio of early ablation at 1 year was £3976 per QALY, with a high probability (89%) of being more cost-effective than deferred ablation at conventional UK decision-making thresholds (currently £20,000 per QALY). Sensitivity analyses using alternative statistical models give qualitatively similar results. Limitations Only 7% of screened patients were recruited, treatment regimens varied significantly and technical success was assessed only in the early ablation group. Conclusions Early endovenous ablation of superficial venous reflux, in addition to compression therapy and wound dressings, reduces the time to healing of venous leg ulcers, increases ulcer-free time and is highly likely to be cost-effective. Future work Longer-term follow-up is ongoing and will determine if early ablation will affect recurrence rates in the medium and long term. Trial registration Current Controlled Trials ISRCTN02335796. Funding This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 23, No. 24. See the NIHR Journals Library website for further project information

    Genetic dissection of grain zinc concentration in spring wheat for mainstreaming biofortification in CIMMYT wheat breeding

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    Wheat is an important staple that acts as a primary source of dietary energy, protein, and essential micronutrients such as iron (Fe) and zinc (Zn) for the world’s population. Approximately two billion people suffer from micronutrient deficiency, thus breeders have crossed high Zn progenitors such as synthetic hexaploid wheat, T. dicoccum, T. spelta, and landraces to generate wheat varieties with competitive yield and enhanced grain Zn that are being adopted by farmers in South Asia. Here we report a genome-wide association study (GWAS) using the wheat Illumina iSelect 90 K Infinitum SNP array to characterize grain Zn concentrations in 330 bread wheat lines. Grain Zn phenotype of this HarvestPlus Association Mapping (HPAM) panel was evaluated across a range of environments in India and Mexico. GWAS analysis revealed 39 marker-trait associations for grain Zn. Two larger effect QTL regions were found on chromosomes 2 and 7. Candidate genes (among them zinc finger motif of transcription-factors and metal-ion binding genes) were associated with the QTL. The linked markers and associated candidate genes identified in this study are being validated in new biparental mapping populations for marker-assisted breeding

    Regulation of mammary gland branching morphogenesis by the extracellular matrix and its remodeling enzymes.

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    A considerable body of research indicates that mammary gland branching morphogenesis is dependent, in part, on the extracellular matrix (ECM), ECM-receptors, such as integrins and other ECM receptors, and ECM-degrading enzymes, including matrix metalloproteinases (MMPs) and their inhibitors, tissue inhibitors of metalloproteinases (TIMPs). There is some evidence that these ECM cues affect one or more of the following processes: cell survival, polarity, proliferation, differentiation, adhesion, and migration. Both three-dimensional culture models and genetic manipulations of the mouse mammary gland have been used to study the signaling pathways that affect these processes. However, the precise mechanisms of ECM-directed mammary morphogenesis are not well understood. Mammary morphogenesis involves epithelial 'invasion' of adipose tissue, a process akin to invasion by breast cancer cells, although the former is a highly regulated developmental process. How these morphogenic pathways are integrated in the normal gland and how they become dysregulated and subverted in the progression of breast cancer also remain largely unanswered questions

    Study of the reaction e^{+}e^{-} -->J/psi\pi^{+}\pi^{-} via initial-state radiation at BaBar

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    We study the process e+eJ/ψπ+πe^+e^-\to J/\psi\pi^{+}\pi^{-} with initial-state-radiation events produced at the PEP-II asymmetric-energy collider. The data were recorded with the BaBar detector at center-of-mass energies 10.58 and 10.54 GeV, and correspond to an integrated luminosity of 454 fb1\mathrm{fb^{-1}}. We investigate the J/ψπ+πJ/\psi \pi^{+}\pi^{-} mass distribution in the region from 3.5 to 5.5 GeV/c2\mathrm{GeV/c^{2}}. Below 3.7 GeV/c2\mathrm{GeV/c^{2}} the ψ(2S)\psi(2S) signal dominates, and above 4 GeV/c2\mathrm{GeV/c^{2}} there is a significant peak due to the Y(4260). A fit to the data in the range 3.74 -- 5.50 GeV/c2\mathrm{GeV/c^{2}} yields a mass value 4244±54244 \pm 5 (stat) ±4 \pm 4 (syst)MeV/c2\mathrm{MeV/c^{2}} and a width value 11415+16114 ^{+16}_{-15} (stat)±7 \pm 7(syst)MeV\mathrm{MeV} for this state. We do not confirm the report from the Belle collaboration of a broad structure at 4.01 GeV/c2\mathrm{GeV/c^{2}}. In addition, we investigate the π+π\pi^{+}\pi^{-} system which results from Y(4260) decay

    Versatility and Stereotypy of Free-Tailed Bat Songs

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    In mammals, complex songs are uncommon and few studies have examined song composition or the order of elements in songs, particularly with respect to regional and individual variation. In this study we examine how syllables and phrases are ordered and combined, ie “syntax”, of the song of Tadarida brasiliensis, the Brazilian free-tailed bat. Specifically, we test whether phrase and song composition differ among individuals and between two regions, we determine variability across renditions within individuals, and test whether phrases are randomly ordered and combined. We report three major findings. First, song phrases were highly stereotyped across two regions, so much so that some songs from the two colonies were almost indistinguishable. All males produced songs with the same four types of syllables and the same three types of phrases. Second, we found that although song construction was similar across regions, the number of syllables within phrases, and the number and order of phrases in songs varied greatly within and among individuals. Last, we determined that phrase order, although diverse, deviated from random models. We found broad scale phrase-order rules and certain higher order combinations that were highly preferred. We conclude that free-tailed bat songs are composed of highly stereotyped phrases hierarchically organized by a common set of syntactical rules. However, within global species-specific patterns, songs male free-tailed bats dynamically vary syllable number, phrase order, and phrase repetitions across song renditions

    Cofactor-mediated conformational control in the bifunctional kinase/RNase Ire1

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    <p>Abstract</p> <p>Background</p> <p>Ire1 is a signal transduction protein in the endoplasmic reticulum (ER) membrane that serves to adjust the protein-folding capacity of the ER according to the needs of the cell. Ire1 signals, in a transcriptional program, the unfolded protein response (UPR) via the coordinated action of its protein kinase and RNase domains. In this study, we investigated how the binding of cofactors to the kinase domain of Ire1 modulates its RNase activity.</p> <p>Results</p> <p>Our results suggest that the kinase domain of Ire1 initially binds cofactors without activation of the RNase domain. RNase is activated upon a subsequent conformational rearrangement of Ire1 governed by the chemical properties of bound cofactors. The conformational step can be selectively inhibited by chemical perturbations of cofactors. Substitution of a single oxygen atom in the terminal β-phosphate group of a potent cofactor ADP by sulfur results in ADPβS, a cofactor that binds to Ire1 as well as to ADP but does not activate RNase. RNase activity can be rescued by thiophilic metal ions such as Mn<sup>2+ </sup>and Cd<sup>2+</sup>, revealing a functional metal ion-phosphate interaction which controls the conformation and RNase activity of the Ire1 ADP complex. Mutagenesis of the kinase domain suggests that this rearrangement involves movement of the αC-helix, which is generally conserved among protein kinases. Using X-ray crystallography, we show that oligomerization of Ire1 is sufficient for placing the αC-helix in the active, cofactor-bound-like conformation, even in the absence of cofactors.</p> <p>Conclusions</p> <p>Our structural and biochemical evidence converges on a model that the cofactor-induced conformational change in Ire1 is coupled to oligomerization of the receptor, which, in turn, activates RNase. The data reveal that cofactor-Ire1 interactions occur in two independent steps: binding of a cofactor to Ire1 and subsequent rearrangement of Ire1 resulting in its self-association. The pronounced allosteric effect of cofactors on protein-protein interactions involving Ire1's kinase domain suggests that protein kinases and pseudokinases encoded in metazoan genomes may use ATP pocket-binding ligands similarly to exert signaling roles other than phosphoryl transfer.</p

    P2X receptor-mediated purinergic sensory pathways to the spinal cord dorsal horn

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    P2X receptors are expressed on different functional groups of primary afferent fibers. P2X receptor-mediated sensory inputs can be either innocuous or nociceptive, depending on which dorsal horn regions receive these inputs. We provide a brief review of P2X receptor-mediated purinergic sensory pathways to different regions in the dorsal horn. These P2X purinergic pathways are identified in normal animals, which provides insights into their physiological functions. Future studies on P2X purinergic pathways in animal models of pathological conditions may provide insights on how P2X receptors play a role in pathological pain states
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