Telomere Length, Proviral Load and Neurologic Impairment in HTLV-1 and HTLV-2-Infected Subjects.

Short or damaged telomeres have been implicated in degenerative conditions. We hypothesized that analysis of telomere length (TL) in human T-cell lymphotropic virus (HTLV) infection and HTLV-associated neuropathy might provide clues to the etiology of HTLV-associated disease and viral dynamics. A subset of 45 human T-cell lymphotropic virus type 1 (HTLV-1), 45 human T-cell lymphotropic virus type 2 (HTLV-2), and 45 seronegative subjects was selected from the larger HTLV Outcomes Study (HOST) cohort, matched on age, sex and race/ethnicity. Telomere-to-single-copy gene (T/S) ratio (a measure of TL) and HTLV-1 and HTLV-2 proviral loads were measured in peripheral blood mononuclear cells (PBMCs) using quantitative PCR (qPCR). Vibration sensation measured by tuning fork during neurologic examinations performed as part of the HOST study allowed for an assessment of peripheral neuropathy. TL was compared between groups using t-tests, linear and logistic regression. Mean T/S ratio was 1.02 ± 0.16 in HTLV-1, 1.03 ± 0.17 in HTLV-2 and 0.99 ± 0.18 in HTLV seronegative subjects (p = 0.322). TL was not associated with HTLV-1 or -2 proviral load. Shorter TL was significantly associated with impaired vibration sense in the HTLV-2 positive group only. Overall, we found no evidence that telomere length was affected by chronic HTLV-1 and HTLV-2 infection. That TL was only associated with peripheral neuropathy in the HTLV-2-positive group is intriguing, but should be interpreted cautiously. Studies with larger sample size and telomere length measurement in lymphocyte subsets may clarify the relationship between TL and HTLV-infection

Relationship Between Glaucoma and Selenium Levels in Plasma and Aqueous Humor

Purpose: To determine the association of plasma and aqueous humor selenium with glaucoma; and to determine those factors influencing biological levels of selenium in patients with glaucoma and cataractMethods: 47 primary open angle glaucoma (POAG) cases and 54 controls were recruited from surgery patients at the University Physician's Ophthalmology Clinic in Tucson, Arizona. Aqueous humor and plasma selenium concentration was determined by high performance liquid chromatography ion channel plasma-mass spectrometry (HPLC ICP-MS). Potential confounders were assessed via questionnaire. Outcome measures included the odds of glaucoma in relation to plasma selenium and aqueous humor selenium. Factors driving plasma and aqueous humor selenium in the study population were determined via linear regression.Results: After adjustment for risk factors and multiple outcomes, the odds of glaucoma in the highest tertile of plasma selenium (OR = 13.51; p=.03) and the middle tertile of aqueous humor selenium (OR = 0.05; p=0.02) were significantly associated with glaucoma. Selenium concentration in plasma and aqueous humor was primarily driven by metabolic factors (cancer, DMII, and ARMD).Conclusions: Although a causal pathway cannot be inferred from the analysis, it may be prudent to explore these relations in a larger sample in varying areas of geographic selenium distribution. Such information could be helpful in examining a larger study population and comparing biological data. Evaluating a subject's selenium levels over time and in relation to glaucoma onset could also lend pertinent informationDriving forces behind selenium concentrations in this population are mainly metabolic in nature. Selenium levels fluctuate in most tissue as it is metabolized by the body. Selenium supplementation is a significant predictor but this effect is small and may be transient as supplementation only temporarily increases selenium pools. It is interesting to note that sex is a significant predictor of aqueous humor selenium but not of plasma selenium. In this model, female sex predicts a decrease in the selenium within the aqueous humor. This point should be explored in future studies that are powered to discern possibly subtle differences that sex plays in relation to selenium concentrations in plasma and aqueous humor and its possible role in glaucoma

Selenium's effects on MMP-2 and TIMP-1 secretion by human trabecular meshwork cells

PURPOSE. Because of the observed increase in incidence of glaucoma among some individuals taking selenium as a dietary supplement, the present study was undertaken to investigate mechanisms of selenium-induced changes in homeostasis of human trabecular meshwork (HTM) cells. Specifically, the impact of selenium on matrix metalloproteinases (MMPs), their inhibitors (tissue inhibitors of metalloproteinases; TIMPs), and the second messengers that regulate MMP expression was investigated in an HTM cell culture model. METHODS. HTM cell cultures were treated with an organic selenium compound (methyl seleninic acid), and changes in secretion and activity of MMPs and TIMPs were analyzed by Western blot and zymography. Changes in extracellular-signalrelated kinases 1 and 2 (ERK1/2) and phospho-ERK1/2 levels were monitored by Western blot analysis of whole-cell lysates prepared from selenium-treated cells. Photographs of cultures over time were used to document selenium-induced changes in cell morphology. RESULTS. Treatment of HTM cells with selenium for 24 hours at doses ranging from 1 to 10 M caused a dose-dependent decrease in the secretion of MMP-2 and TIMP-1. Treatment for 6 hours revealed a significant decrease in MMP-2 and TIMP-1 at the highest dose. MMP-1, -3, and -9 and TIMP-2 were either not detected or their secretion was not consistently influenced by selenium treatment. Selenium treatment caused a significant decrease in ERK1/2 phosphorylation, but no change in overall ERK protein levels. Selenium treatment resulted in dose-dependent, reversible changes in HTM cell-matrix associations. CONCLUSIONS. Selenium-induced changes in MMP-2/TIMP-1 secretion may alter the balance of extracellular matrix turnover in the conventional outflow pathway and cause an increase in intraocular pressure that eventually leads to glaucoma. (Invest Ophthalmol Vis Sci

Demographic determinants of syphilis seroprevalence among U.S. blood donors, 2011-2012.

BackgroundNo cases of transfusion-transmitted syphilis have been described for over four decades. While there is mandatory transfusion screening for syphilis, the absence of transmission is in part ascribed to a low prevalence of syphilis in the blood donor population, the concomitant use of antibiotics in a high proportion of transfusion recipients, allied with poor survival of T. pallidum during refrigerated storage of blood products.MethodsA cross-sectional retrospective data analysis was conducted to ascertain the prevalence of Treponema pallidum antibodies in U.S. blood donors by demography and geography. Routine blood donation testing data and demographics were extracted from the data warehouse of a large network of U.S. blood centers. Crude and adjusted prevalence of T. pallidum antibodies and active syphilis infection were calculated, and GIS mapping was used to illustrate geographic distribution.ResultsThe prevalence of T. pallidum seropositivity and active syphilis in first time donors was 162.6 (95% CI 145.5-181.2) per 100,000 donors and 15.8 (95% CI 10.8-22.3) per 100,000 donors, respectively. The odds of T. pallidum seropositivity were significantly elevated in African American (OR = 18.9, 95% CI 14.2-25.2), and Hispanic (OR = 2.8, 95% CI 2.0-3.8) as compared to Caucasian donors. Similarly, the odds of active T. pallidum infections were significantly higher in African American (OR 15.0, 95% CI 7.0-32.3) and Hispanic (OR = 5.8, 95% CI 2.9-11.6) as compared to Caucasian donors. Syphilis seropositivity was associated with first time blood donation, increasing age, lower education, birth outside the US, and positive tests for HIV and HCV. Geographically, T. pallidum seropositivity was increased in southern and western regions of the US.ConclusionsGiven the low seroprevalence of syphilis in blood donors, continued screening remains debatable; however it may provide a public health benefit through surveillance of at-risk populations

Water administration and the risk of syncope and presyncope during blood donation: a randomized clinical trial.

BackgroundBlood centers rely heavily on adolescent donors to meet blood demand, but presyncope and syncope are more frequent in younger donors. Studies have suggested administration of water before donation may reduce syncope and/or presyncope in this group.Study design and methodsWe conducted a randomized, controlled trial to establish the effect of preloading with 500 mL of water on the rate of syncope and presyncope in adolescent donors. School collection sites in Eastern Cape Province of South Africa were randomized to receive water or not. Incidence of syncope and presyncope was compared between randomization groups using multivariable logistic regression.ResultsOf 2464 study participants, 1337 received water and 1127 did not; groups differed slightly by sex and race. Syncope or presyncope was seen in 23 (1.7%) of the treatment and 18 (1.6%) of the control arm subjects. After adjusting for race, sex, age, and donation history, there was no difference in outcome between the water versus no water arms (adjusted odds ratio [OR], 0.80; 95% confidence interval [CI], 0.42-1.53). Black donors had sevenfold lower odds of syncope or presyncope than their white counterparts (adjusted OR, 0.14; 95% CI, 0.04-0.47).ConclusionPreloading adolescent donors with 500 mL of water did not have a major effect in reducing syncope and presyncope in South African adolescent donors. Our adolescent donors had lower overall syncope and presyncope rates than similar populations in the United States, limiting the statistical power of the study. We confirmed much lower rates of syncope and presyncope among young black donors

Demographic determinants of syphilis seroprevalence among U.S. blood donors, 2011-2012.

BackgroundNo cases of transfusion-transmitted syphilis have been described for over four decades. While there is mandatory transfusion screening for syphilis, the absence of transmission is in part ascribed to a low prevalence of syphilis in the blood donor population, the concomitant use of antibiotics in a high proportion of transfusion recipients, allied with poor survival of T. pallidum during refrigerated storage of blood products.MethodsA cross-sectional retrospective data analysis was conducted to ascertain the prevalence of Treponema pallidum antibodies in U.S. blood donors by demography and geography. Routine blood donation testing data and demographics were extracted from the data warehouse of a large network of U.S. blood centers. Crude and adjusted prevalence of T. pallidum antibodies and active syphilis infection were calculated, and GIS mapping was used to illustrate geographic distribution.ResultsThe prevalence of T. pallidum seropositivity and active syphilis in first time donors was 162.6 (95% CI 145.5-181.2) per 100,000 donors and 15.8 (95% CI 10.8-22.3) per 100,000 donors, respectively. The odds of T. pallidum seropositivity were significantly elevated in African American (OR = 18.9, 95% CI 14.2-25.2), and Hispanic (OR = 2.8, 95% CI 2.0-3.8) as compared to Caucasian donors. Similarly, the odds of active T. pallidum infections were significantly higher in African American (OR 15.0, 95% CI 7.0-32.3) and Hispanic (OR = 5.8, 95% CI 2.9-11.6) as compared to Caucasian donors. Syphilis seropositivity was associated with first time blood donation, increasing age, lower education, birth outside the US, and positive tests for HIV and HCV. Geographically, T. pallidum seropositivity was increased in southern and western regions of the US.ConclusionsGiven the low seroprevalence of syphilis in blood donors, continued screening remains debatable; however it may provide a public health benefit through surveillance of at-risk populations