Drawing the line between commensal and pathogenic <it>Gardnerella vaginalis </it>through genome analysis and virulence studies

<p>Abstract</p> <p>Background</p> <p>Worldwide, bacterial vaginosis (BV) is the most common vaginal disorder. It is associated with risk for preterm birth and HIV infection. The etiology of the condition has been debated for nearly half a century and the lack of knowledge about its cause and progression has stymied efforts to improve therapy and prevention. <it>Gardnerella vaginalis </it>was originally identified as the causative agent, but subsequent findings that it is commonly isolated from seemingly healthy women cast doubt on this claim. Recent studies shedding light on the virulence properties of <it>G. vaginalis</it>, however, have drawn the species back into the spotlight.</p> <p>Results</p> <p>In this study, we sequenced the genomes of a strain of <it>G. vaginalis </it>from a healthy woman, and one from a woman with bacterial vaginosis. Comparative analysis of the genomes revealed significant divergence and <it>in vitro </it>studies indicated disparities in the virulence potential of the two strains. The commensal isolate exhibited reduced cytotoxicity and yet the cytolysin proteins encoded by the two strains were nearly identical, differing at a single amino acid, and were transcribed at similar levels. The BV-associated strain encoded a different variant of a biofilm associated protein gene and demonstrated greater adherence, aggregation, and biofilm formation. Using filters with different pore sizes, we found that direct contact between the bacteria and epithelial cells is required for cytotoxicity.</p> <p>Conclusions</p> <p>The results indicated that contact is required for cytotoxicity and suggested that reduced cytotoxicity in the commensal isolate could be due to impaired adherence. This study outlines two distinct genotypic variants of <it>G. vaginalis</it>, one apparently commensal and one pathogenic, and presents evidence for disparate virulence potentials.</p

Elderly Men Have Low Levels of Anti-Müllerian Hormone and Inhibin B, but with High Interpersonal Variation: A Cross-Sectional Study of the Sertoli Cell Hormones in 615 Community-Dwelling Men

The Sertoli cells of the testes secrete anti-Müllerian hormone (Müllerian inhibiting Substance, AMH) and inhibin B (InhB). AMH triggers the degeneration of the uterine precursor in male embryos, whereas InhB is part of the gonadal-pituitary axis for the regulation of sperm production in adults. However, both hormones are also putative regulators of homeostasis, and age-related changes in these hormones may therefore be important to the health status of elderly men. The levels of AMH in elderly men are unknown, with limited information being available about age-related changes in InhB. We have therefore used ELISAs to measure Sertoli cell hormone levels in 3 cohorts of community-dwelling men in New Zealand. In total, 615 men were examined, 493 of which were aged 65 or older. Serum AMH and InhB levels inversely correlated with age in men older than 50 years (p<0.001) but not in the younger men. A minority of elderly men had undetectable levels of AMH and InhB. The variation in hormone levels between similarly aged men increased with the age of men. AMH and InhB partially correlated with each other as expected (r = 0.48, p<0.001). However, the ratio of the two Sertoli hormones varied significantly between men, with this variation increasing with age. Elderly men selected for the absence of cardiovascular disease had AMH levels similar to those of young men whereas their InhB levels did not differ from aged-matched controls. These data suggests that Sertoli cell number and function changes with age, but with the extent and nature of the changes varying between men

Therapy for prevention and treatment of skin ionizing radiation damage: A review

Purpose: Radiologic accidents or terrorist acts involving radioactive material, as well as radiation exposure in medical or industrial procedures are potential sources of risk for human health. All these risks share a common element, exposure to ionizing radiation. The extent of ionizing radiation injury will depend on a number of independent variables such as dose, type of radiation and tissue, etc. As a result of ionizing radiation exposure, biological effects can take place in acute or long term manner. As in the case of other self-renewing tissues (eg. hematopoietic system and intestinal epithelium), skin is also extremely sensitive to ionizing radiation. In this way, appropriate management of radiation skin effects might improve the therapeutic benefit of medical radiation therapy, as well as reduce the mortality associated with any radiological incident (eg. accident or terrorist attack). For this reason, current and potential future treatment approaches for skin radiation injury are reviewed in this work. Conclusions: Unfortunately, there is not sufficient evidence for establishing a standard treatment to prevent or mitigate radiation-induced cutaneous injury. Thus, continued research is necessary to achieve effective therapies to address this important health problem.This work was supported by the Spanish Ministry of Economy, Industry and Competitiveness (RTC-2016-5451-1) through the European Regional Development Funds (ERDF).info:eu-repo/semantics/publishedVersio