Physical Activity and Health Outcomes Among HIV-Infected Men Who Have Sex with Men: A Longitudinal Mediational Analysis

Background

Low physical activity is associated with depression, which may, in turn, negatively impact antiretroviral therapy (ART) adherence among HIV-infected individuals; however, prior studies have not investigated the relationships between physical inactivity and ART non-adherence.

Purpose

The purpose of this study was to examine the association of physical inactivity, depression, ART non-adherence, and viral load in HIV-infected men who have sex with men.

Methods

The sample (N?=?860) was from a large, multicenter cohort of HIV-infected patients engaged in clinical care.

Results

Across time, depression mediated the relationship between physical inactivity and ART non-adherence (γ?=?0.075) and the relationship between physical inactivity and viral load (γ?=?0.05). ART non-adherence mediated the relationship between depression and viral load (γ?=?0.002) and the relationship between physical inactivity and viral load (γ?=?0.009).

Conclusions

Low levels of physical activity predicted increased depression and poor ART adherence over time, which subsequently predicted higher viral load.     

Paternal age and birth defects: how strong is the association

Sir, Yang et al. (2006) examined the association of paternal ageand birth defects, one of which was Down syndrome,     

High-dose-rate remote afterloaders for intraoperative radiation therapy

INTRAOPERATIVE RADIATION THERAPY (IORT) is a treatment option that directly irradiates a surgically exposed tumor or tumor bed while preventing radiation exposure of normal tissues.THIS ARTICLE DISCUSSES the high-dose-rate intraoperative radiation therapy (HDR-IORT) technique by reviewing the roles of IORT team members, discussing needed equipment and supplies, describing quality assurance processes, explaining the HDR-IORT treatment delivery procedure, and reviewing the post-treatment phase. AORN J 86 (November 2007) 827-836.     

Pubertal supplementation of lipotropes in female rats reduces mammary cancer risk by suppressing histone deacetylase 1

Purpose

The time from puberty to the first pregnancy is known to be important for a woman’s life-time breast cancer risk. Recent studies suggest that epigenetic mechanisms may involve pubertal maturation processes, which can affect the risk of breast cancer in later life. Epigenetic alterations are related to lipotropes (methionine, choline, folate, and vitamin B₁₂), which are methyl donors and cofactors. However, the effects of pubertal supplementation of lipotropes in breast cancer remain largely unknown.

Methods

Twenty female Sprague–Dawley rats, aged 6 weeks, were divided into two groups and fed a normal control diet or a lipotrope-fortified diet formulated to provide five times basal levels of lipotropes during puberty. All rats were injected intraperitoneally with N-nitroso-N-methylurea at 50 days of age to induce mammary tumors.

Results

Tumor multiplicity and tumor volume decreased significantly as a result of lipotrope supplementation. Interestingly, quantitative RT-PCR revealed significantly decreased expression of histone deacetylase 1 (Hdac1) and DNA methyltransferase 1 (Dnmt1) genes in tumor tissues of the rats supplemented with lipotrope-fortified diet, suggesting that reduced risk of breast cancer can be attributed, at least in part, to decreased expression of these two genes.

Conclusions

This study demonstrates that supplementation of lipotrope-fortified diet during puberty suppresses tumor growth, potentially through down-regulating Hdac1 and Dnmt1 gene expression. Our findings suggest that pubertal methyl diet plays an important role in the etiology of breast cancer, and further studies are warranted to develop preventative strategies against breast cancer.     

Ty1-copia-retrotransposon Behavior in a Polyploid Cotton

Retrotransposons constitute a ubiquitous and dynamic component of plant genomes. Intragenomic and intergenomic comparisons of related genomes offer potential insights into retrotransposon behavior and genomic effects. Here, we have used fluorescent in-situ hybridization to determine the chromosomal distributions of a Ty1-copia-like retrotransposon in the cotton AD-genome tetraploid Gossypium hirsutum and closely related putative A- and D-genome diploid ancestors. Retrotransposon clone A108 hybridized to all G. hirsutum chromosomes, approximately equal in intensity in the A- and D-subgenomes. Similar results were obtained by hybridization of A108 to the A-genome diploid G. arboreum, whereas no signal was detected on chromosomes of the D-genome diploid G. raimondii. The significance and potential causes of these observations are discussed.