Effect of uropathogens on in vitro encrustation of polyurethane double J ureteral stents

Polyurethane stents are used when there is an obstruction to the flow of urine. A majority of the patients with such stents are at the risk of urinary tract infection and salt encrustation. The present study is aimed at analyzing the in vitro encrustation of calcium oxalate and other salts in the presence of common uropathogens (E. coli and P. mirabilis) on films made from Tecoflex^®, a commercial grade polyurethane. In the absence of uropathogens, sodium ions and ammonia favor calcium adsorption whereas magnesium ions greatly depress it, resulting in increased hydrophillicity of the stent. With E. coli, Mg ions enhance the encrustation of calcium, whereas the other salts decrease its deposition. In case of P. mirabilis, irrespective of the type of salt, it enhances calcium encrustation except in the presence of sodium ions. Adhesion of uropathogens to the stent surface was higher in the presence of bovine serum albumin. Understanding the dynamics between various salts and microorganism in the urine, and urine–stent interface would aid in designing stents that are inert, resist encrustation and biofilm formation.     

Selective aldosterone blockade suppresses atrial tachyarrhythmias in heart failure

INTRODUCTION: Renin-angiotensin-aldosterone system activation may be involved in the pathogenesis of atrial arrhythmias in congestive heart failure (CHF). The effects of aldosterone blockade on atrial tachyarrhythmias have not been evaluated. This study's aim was to determine whether selective aldosterone blockade suppresses atrial tachyarrhythmia inducibility and modifies atrial electrical and/or structural remodeling in a canine model of rapid ventricular pacing (RVP)-induced CHF. METHODS AND RESULTS: Dogs were assigned randomly to treatment with oral placebo or eplerenone (50 mg/day) and divided into four groups: two sham-operated (no RVP) and two RVP groups. After 5 weeks of no RVP or RVP at 230 beats/min along with concurrent placebo or eplerenone treatment, dogs underwent electrophysiologic and echocardiographic studies. Sustained atrial tachyarrhythmia inducibility (>10-minute duration), atrial effective refractory periods (ERPs), systolic and diastolic function, and left atrial and left ventricular (LV) chamber sizes were assessed. Placebo-treated RVP dogs developed CHF with LV systolic and diastolic dysfunction, left atrial and LV enlargement, increased atrial ERPs, and inducible sustained atrial tachyarrhythmias. Eplerenone treatment in RVP dogs significantly suppressed sustained atrial tachyarrhythmia inducibility, nonuniformly prolonged atrial ERPs and attenuated LV diastolic dysfunction without modifying left atrial or LV dilation or ejection fractions in CHF. Isoproterenol (2-4 microg/min) reversed eplerenone's atrial antiarrhythmic and ERP prolonging effects in CHF. Eplerenone did not alter atrial ERPs in sham (no RVP) dogs without CHF. CONCLUSIONS: Eplerenone suppresses inducibility of sustained atrial tachyarrhythmias, selectively prolongs atrial ERPs, and attenuates LV diastolic remodeling in RVP-induced CHF. Aldosterone blockade may be a promising new approach for atrial tachyarrhythmia prevention in CHF.     

Properties of HTLV-I transformed CD8 T-cells in response to HIV-1 infection

HIV-1 infection studies of primary CD8⁺ T-cells are hampered by difficulty in obtaining a significant number of targets for infection and low levels of productive infection. Further, there exists a paucity of CD8-expressing T-cell lines to address questions pertaining to the study of CD8⁺ T-cells in the context of HIV-1 infection. In this study, a set of CD8⁺ T-cell clones were originated through HTLV-I transformation in vitro, and the properties of these cells were examined. The clones were susceptible to T-cell tropic strains of the virus and exhibited HIV-1 production 20-fold greater than primary CD4⁺ T-cells. Productive infection resulted in a decrease in expression of CD8 and CXCR4 molecules on the surface of the CD8⁺ T-cell clones and antibodies to these molecules abrogated viral binding and replication. These transformed cells provide an important tool in the study of CD8⁺ T-cells and may provide important insights into the mechanism(s) behind HIV-1 induced CD8⁺ T-cell dysfunction.     

Peer influences, body-image dissatisfaction, eating dysfunction and self-esteem in adolescent girls

A sample of 344 adolescent girls completed a variety of measures designed to index the associations among peer influences, body-image dissatisfaction, eating dysfunction and self-esteem. Results indicated that participants were significantly similar to their nominated friends on self-esteem, but not body image or eating disturbance. Peer measures were significantly associated with body dissatisfaction, eating problems and self-esteem. Peer suppression of feelings, internalization of the thin-ideal and appearance comparison were significant mediators in path analyses testing the direct and indirect role of peer influences on outcome variables. Implications for intervention and prevention programs are discussed.     

South Indian men with reduced CAG repeat length in the androgen receptor gene have an increased risk of prostate cancer

The androgen receptor (AR) gene possesses polymorphic CAG tandem repeats and the repeat length has been inversely related to the risk of prostate cancer (PCa). The distinct ethnic variation in the CAG repeat length may be correlated to differences in PCa risk in different populations. To evaluate the CAG repeat length in the AR gene and the implications for PCa, we screened 87 PCa patients and 120 control subjects from South India. The mean CAG repeat length in PCa patients was significantly smaller than that of controls (17.0 vs 20.7; P<0.001). Men with 19 CAG repeats had a significantly increased risk of cancer compared to those with >19 CAG repeats (age-adjusted OR=7.01; 95% CI=3.52–13.94; P<0.001). However, no significant association was observed between CAG repeats and age of onset or prostate-specific antigen levels. Although there was a trend towards shorter CAG repeat length in high grades of cancer, it was not significant (P=0.085). Thus, our results suggest an association between short CAG repeats in the AR gene and PCa risk in South Indian men. Further, we propose that CAG repeats could be used as a prognostic marker for PCa diagnosis.     

Orthodontic marketing through social media networks: The patient and practitioner's perspective

Objective:To (1) assess orthodontic patient and practitioner use of and preferences for social media and (2) investigate the potential benefit of social media in marketing and communication strategies in orthodontic practices.Materials and Methods:A survey was developed and randomly distributed to orthodontists via the American Association of Orthodontists and to patients/parents via private practices throughout the United States. Participants were asked to answer questions related to their use of social media and their perceptions of the use of social media in the orthodontic practice.Results:Of the participants, 76% of orthodontists and 89% of patients/parents use social media. Furthermore, Facebook was the social media platform that was most preferred. Social media use was more common in female and younger adult participants. Orthodontists posted information more often in the morning (40%) and afternoon (56%), and patients/parents used social media mainly in the evening (76%). The most commonly used marketing strategies in the orthodontic practices were social media (76%) and a practice website (59%). Social media and practice websites were positively related with new patient starts (P  =  .0376, P  =  .0035, respectively).Conclusions:Most orthodontists and patients/parents used social media. Social media may be an effective marketing and communication tool in an orthodontic practice.     

Serum leptin,thyroxine and thyroid-stimulating hormone levels interact to affect cognitive function among US adults: evidence from a large representative survey

Neuroanatomical connections point to possible interactions between areas influencing energy homeostasis and those influencing cognition. We assessed whether serum leptin, thyroxine, and thyroid stimulating hormone (TSH) levels are associated with and interact to influence cognitive performance among US adults. Data from the National Health and Nutrition Examination Survey III (1988–1994) were used. Measures included a battery of neuropsychological tests and serum leptin, thyroxine, and TSH levels (20–59-year-old: n = 1114–2665; 60–90-year-old: n = 1365–5519). Among those 20–59-year-old, the middle tertile of leptin (vs. first tertile) was inversely related to the number of errors on the symbol digits substitution test. Increased thyroxine level was associated with a poorer performance on the serial digits test in the 20–59-year-old, but a better performance on the math test in 60–90-year-old group. TSH was associated with poor performance on various tests in the 20–59-year-old, but better performance in the 60–90-year-old group. Significant antagonistic interactions were found in both age groups between thyroxine, TSH, and leptin for a number of tests, including between leptin and thyroxine in the 60–90-year-old group in their association with word recall-correct score. We found significant associations of our main exposures with cognitive function among US adults, going in opposite directions between age groups in the cases of thyroid hormonal levels, as well as some interactive effects between exposures. It is important to conduct prospective cohort studies to provide further insight into potential interventions that would assess interactive effects of various hormonal replacement regimens.