Incidence of exertional right ventricular wall motion abnormalities in patients with coronary artery disease

To evaluate the role of analysis of right ventricular function with exercise in patients with presumed coronary artery disease referred for radionuclide ventriculography, the records of 55 patients referred to our laboratory over a 19-month period were reviewed. All underwent rest and exercise first-pass radionuclide stress testing and cardiac catheterization within a period of four months. Three groups were identified: (1) patients with normal exercise right ventricular function (n = 24); (2) patients with exercise-induced right ventricular regional wall motion abnormalities (n = 15); and, (3) patients with abnormal resting right ventricular function without new exercise abnormalities (n = 16). Patients in each group were similar in age, sex, baseline left ventricular function, medication usage, and indication for study. The incidence of right coronary artery disease was identical in the three groups, as was the incidence of left ventricular functional abnormalities with exercise. Patients with proximal right coronary artery disease were more likely to have reduced left ventricular ejection fraction and more extensive coronary artery disease than those without disease at this site. We conclude that: (1) analysis of rest and exercise right ventricular function does not allow prediction of coronary anatomy in an unselected group of patients; (2) normal right ventricular function with exercise is compatible with extensive coronary artery disease, including proximal right coronary artery disease; and (3) abnormal exercise right ventricular function may be due to exertional left ventricular dysfunction in the absence of proximal right coronary artery disease.     

Instability and translocation through nanopores of DNA interacting with single-layer materials

In this study, we use classical applied mathematical modelling to employ the 6–12 Lennard-Jones potential function along with the continuous approximation to investigate the interaction energies between a double-stranded deoxyribonucleic acid (dsDNA) molecule and two-dimensional nanomaterials, namely graphene (GRA), hexagonal boron nitride (h-BN), molybdenum disulphide (MoS₂), and tungsten disulphide (WS₂). Assuming that the dsDNA molecule has a perpendicular distance Δ above the nano-sheet surface, we calculated the molecular interaction energy and determined the relation between the location of the minimum energy and Δ. We also investigated the interaction of a dsDNA molecule with the surface of each nano-sheet in the presence of a circular hole simulating a nanopore. The radius of the nanopore that results in the minimum energy was determined. Our results show that the adsorption energies of the dsDNA molecule with GRA, h-BN, MoS₂, and WS₂ nano-sheets corresponding to the perpendicular distance Δ = 20 Å are approximately 70, 82, 28, and 26 (kcal mol⁻¹), respectively, and we observed that the dsDNA molecule moves through nanopores of radii greater than 12.2 Å.

Using classical applied mathematical modelling to employ the 6–12 Lennard-Jones potential function along with the continuous approximation to investigate the interaction energy between dsDNA and 2D-nanomaterials, namely GRA, h-BN, MoS₂ and WS₂ sheets.     

Vascular Management During Live Donor Nephrectomy: An Online Survey Among Transplant Surgeons

In 2006, a survey from the American Society of Transplant Surgeons disclosed significant and sometimes fatal hemorrhagic events in live donor nephrectomies (LDN) related to failure of clips, leading to the contraindication of the Weck® Hem‐o‐lok® clip for control of the renal artery during LDN. A survey regarding vascular control techniques, their perceived safety ratings and their failures was sent to 645 European Society for Organ Transplantation members who profiled their profession as “surgeon” and selected “kidney” as organ type. Two hundred forty‐three (41%) members responded, of whom 171 (63.3%) independently perform LDN. Their responses were analyzed. For arterial and venous vascular control, the GIA? and TA?stapler are used most frequently, and were rated the safest. Of the 121 reported hemorrhagic events, slippage and dislodgement of clips occurred at least 58 times, while stapler malfunction occurred at least 40 times. One donor death from hemorrhage related to clip dysfunction was reported. Hemorrhagic complications of LDN with fatal and non‐fatal outcomes still occur. Strikingly, many surgeons do not use the vascular closing technique that they consider most safe. Failure of non‐transfixion techniques is associated with greater risks for the donor. Control of major vessels in LDN must employ transfixion techniques for optimal donor safety.

     

HIV disclosure patterns, predictors, and psychosocial correlates among HIV positive women in Zimbabwe

Disclosure of positive HIV status in Sub-Saharan Africa has been associated with safer sexual practices and better antiretroviral therapy (ART) adherence, but associations with psychosocial function are unclear. We examined patterns and psychosocial correlates of disclosure in a Zimbabwean community. Two hundred HIV positive women at different stages of initiating ART participated in a cross-sectional study examining actual disclosures, disclosure beliefs, perceived stigma, self-esteem, depression, and quality of life. Ninety-seven percent of the women disclosed to at least one person, 78% disclosed to their current husband/partner, with an average disclosure of four persons per woman. The majority (85-98%) of disclosures occurred in a positive manner and 72-95% of the individuals reacted positively. Factors significantly correlated with HIV disclosure to partners included being married, later age at menses, longer duration of HIV since diagnosis, being on ART, being more symptomatic at baseline, ever having used condoms, and greater number of partners in the last year. In multivariate analysis, being married and age at menses predicted disclosure to partners. Positive disclosure beliefs, but not the total number of disclosures, significantly correlated with lower perceived stigma (ρ = 0.44 for personalized subscale and ρ = 0.51 for public subscale, both p<0.0001), higher self-esteem (ρ = 0.15, p=0.04), and fewer depressive symptoms (ρ = -0.14, p=0.05). In conclusion, disclosure of positive HIV status among Zimbabwean women is common and is frequently met with positive reactions. Moreover, positive disclosure beliefs correlate significantly with psychosocial measures, including lower perceived stigma, higher self-esteem, and lower depression.     

Enhanced prefrontal serotonin 2A receptor signaling in the subchronic phencyclidine mouse model of schizophrenia

Prefrontal serotonin 2A receptors (5‐HT_2ARs) have been linked to the pathogenesis and treatment of schizophrenia. Many antipsychotics fully occupy 5‐HT_2AR at clinical relevant doses, and activation of 5‐HT_2A receptors by lysergic acid diethylamide (LSD) and LSD‐like drugs induces a schizophrenia‐like psychosis in humans. Subchronic phencyclidine (PCP) administration is a well‐established model for schizophrenia‐like symptoms in rodents. The aim of the present study was to investigate whether subchronic PCP administration changes expression, binding, or functionality of cortical 5‐HT_2ARs. As a measure of 5‐HT_2AR functionality, we used the 5‐HT_2AR agonist 2,5‐dimethoxy‐4‐iodoamphetamine (DOI)‐induced head‐twitch response (HTR) and mRNA expression of the immediate‐early genes (IEGs) activity‐related cytoskeletal associated‐protein (Arc), c‐fos, and early growth response protein 2 (egr‐2) in the frontal cortex. Mice were treated with PCP (10 mg/kg) or saline for 10 days, followed by a 5‐day washout period. The PCP pretreatment increased the overall induction of HTR and frontal cortex IEG mRNA expression following a single challenge with DOI. These functional changes were not associated with changes in 5‐HT_2AR binding. Also, binding of the 5‐HT_1AR and the 5‐HT transporter was unaffected. Finally, basal mRNA level of Arc was increased in the prefrontal cortex after subchronic PCP administration as revealed with in situ hybridization. Together these findings indicate that PCP administration produces changes in the brain that result in an increase in the absolute effect of DOI. Therefore, neurotransmission involving the 5‐HT_2AR could contribute to the behavioral deficits observed after PCP treatment. © 2013 Wiley Periodicals, Inc.