The Relationship Between Social Support,HIV Serostatus,and Perceived Likelihood of Being HIV Positive Among Self-Settled Female,Foreign Migrants in Cape Town,South Africa

Female cross-border migrants experience elevated risks for HIV, and migrants in South Africa may face additional risks due to the country’s underlying HIV prevalence. These risks may be mitigated by the receipt of social support. A behavioral risk-factor survey was administered using respondent-driven sampling. Multivariable regression models assessed the relationships between social support and two HIV outcomes: HIV serostatus and perceived HIV status. Low social support was not significantly associated with HIV status (aOR?=?1.03, 95?% CI 0.43–2.46), but was significantly related to a perception of being HIV positive (aPR?=?1.36, 95?% CI 1.04–1.78). Age, marital status, and education level were significantly associated with HIV serostatus. Illegal border-crossing, length of time in South Africa, anal sex, and transactional sex were significantly associated with aperception of being HIV positive. Future research should investigate how HIV risks and the receipt of social support change throughout the migration process.     

Versatility of gene therapy vectors through viruses

Several viruses have been engineered for gene therapy applications, and the specific properties of each viral vector have been exploited to target a variety of inherited and acquired diseases. Preclinical and clinical studies demonstrated that viral vectors are highly versatile tools capable of efficient transfer of foreign genetic information into almost all cell types and tissues. Gene therapy applications depend on vector characteristics, such as host range, cell- or tissue-specific targeting, genome integration, efficiency and duration of transgene expression, packaging capacity, and suitability for scale-up production. This review discusses the advances in the development of viral vectors, with particular emphasis on how knowledge of virus biology has been exploited to design a variety of vectors with improved safety characteristics and efficiency, potentially suitable for a large number of gene therapy applications.     

Convective flow increases lipoplex delivery rate to in vitro cellular monolayers

The mass transport characteristics of cationic, nonviral liposome-DNA plasmid complexes (lipoplexes) were evaluated over a range of fluid shear stresses. The typical case of stagnant flow transfection was expanded to include controlled fluid convection provided by constant flow through a parallel plate flow chamber. Equations describing the transport of lipoplex by sedimentation and convection were derived from theory and solved numerically. Instantaneous lipoplex delivery rate and total lipoplex surface delivery during a 72-h transfection were estimated for two shear stress levels and for static conditions. Theory predicted that lipoplex is delivered to the cell surface more than 12- to 19-fold faster through the addition of convection, at least for physiologic shear stresses of 2.3-9.7 dyn/cm2, respectively. These calculations were tested experimentally using a cell line (ECV-304) transfected with fluorescently labeled plasmid DNA formulated into a lipoplex. Transfections were conducted during cellular exposure to the same known, uniform levels of fluid shear stress presumed in theoretical calculations. Lipoplex delivery was increased by more than nine-fold at 2.3 dyn/cm2 compared to the static case as assessed by flow cytometric measurement. Lipoplex delivery was modestly reduced at the highest fluid shear stress, to six-fold of the static case, consistent with the disruption of lipoplex-cell binding mediated by hydrodynamic forces. The complicated relationship between fluid convection and lipoplex delivery has important implications for nonviral gene therapy.     

Glucose Lowering,Hypoglycemia, and Cardiovascular Disease Risk

Diabetes determines an increased risk of micro- and macrovascular complications, and is associated with a growing disability burden. Although the efficacy of intensive glycemic control in reducing the risk of microvascular complications has been firmly established, a lively debate continues on the relationship between intensive glucose control and macrovascular complications. Recently, the conflicting results of randomized controlled trials designed to evaluate the efficacy of intensive glucose control on cardiovascular disease fueled such debate. While the UKPDS post-trial study and the DCCT/EDIC showed an important “legacy effect” with persistent reductions in cardiovascular disease risk, ADVANCE and VADT found no effect of intensive glucose control on major cardiovascular events. The ACCORD study reported an increased risk for cardiovascular and total mortality associated with intensive glucose control. This review explores the value of intensive therapeutic strategies aimed at lowering indices of glycemic control to near-normal levels on the cardiovascular risk of patients with type 1 and 2 diabetes.     

Thyroid function and structure are affected in childhood obesity

OBJECTIVE: Alterations in thyroid function are reported in obesity, although no relevant data exist on the thyroid structure of these patients and the frequency of autoimmunity. The aim of our study was to evaluate the involvement of the thyroid gland in a large group of obese children. DESIGN: This was a cross-sectional study. METHODS: The study was conducted between March 2004 and December 2007 in 186 overweight and obese children. In all subjects, serum free T(3), free T(4), TSH, antithyroid antibodies, and a thyroid ultrasound were assessed. A total ot 40 healthy children matched for age and of normal weight for height served as controls. RESULTS: A total of 23 children (12.4%) showed antithyroid antibodies and an ultrasound pattern suggestive of Hashimoto's thyroiditis (group A). Of them, 20 (10.8%) showed antithyroid antibodies and normal ultrasound (group B). A total of 70 subjects (37.6%) showed absent antithyroid antibodies and an ultrasound pattern suggestive of Hashimoto's thyroiditis (group C), and 73 children (39.2%) showed no thyroid antibodies with normal ultrasound (group D). TSH was higher in groups A and C compared with groups B and C, and controls (P < 0.05). Mean free T(4) was lower in group B (P < 0.05) than in controls, whereas free T(3) was higher in group C than in controls (P < 0.05). TSH and body mass index sd scores were significantly correlated in group C (P < 0.001), and TSH was also significantly associated with the degree of thyroid structure alterations (P < 0.05). CONCLUSION: Obese children frequently show alterations of thyroid structure and function that are not completely explained by the presence of an autoimmune involvement.     

The risk profile for obstructive sleep apnea does not affect the recurrence of atrial fibrillation

BACKGROUND: Obstructive sleep apnea (OSA) has been linked to increased prevalence and recurrence of atrial fibrillation (AF). We hypothesized that OSA may aggravate AF in patients with pacemakers implanted for sinus bradycardia who had documented paroxysmal AF. METHODS: Seventy-two patients (36 M, aged 77 +/- 6 years) completed the study. All patients received a dual-chamber pacemaker equipped with diagnostic and preventive functions for AF. OSA was diagnosed with the Berlin Questionnaire, which is validated to identify patients with OSA. Four-month continuous pacemaker recordings were collected for all patients. RESULTS: OSA was diagnosed in 28% of patients. Patients at high risk for OSA (HR group) and patients at low risk for OSA (LR group) were equivalent for gender, age, and body mass index. The rate of hypertension was higher in HR than in LR group (90% vs 44%, P < 0.01). The prevalence of paroxysmal AF during the study period was similar in HR and LR group (53% vs 44%, P = NS). Overall number of AF episodes per month was not significantly different between HR and LR group (7 +/- 13 vs 36 +/- 122, P = NS). Similarly, AF burden (AF%) was not significantly different between HR and LR group (0.3 +/- 0.6 vs 2.0 +/- 4.8, P = NS). Circadian distribution of AF episodes was similar in both groups. CONCLUSION: Long-term pacemaker recording of AF recurrence, AF burden, and its circadian distribution is similar in patients with paroxysmal AF at high risk for OSA and those at low risk for OSA.     

Influence of hemolysis on routine clinical chemistry testing.

BACKGROUND: Preanalytical factors are the main source of variation in clinical chemistry testing and among the major determinants of preanalytical variability, sample hemolysis can exert a strong influence on result reliability. Hemolytic samples are a rather common and unfavorable occurrence in laboratory practice, as they are often considered unsuitable for routine testing due to biological and analytical interference. However, definitive indications on the analytical and clinical management of hemolyzed specimens are currently lacking. Therefore, the present investigation evaluated the influence of in vitro blood cell lysis on routine clinical chemistry testing. METHODS: Nine aliquots, prepared by serial dilutions of homologous hemolyzed samples collected from 12 different subjects and containing a final concentration of serum hemoglobin ranging from 0 to 20.6 g/L, were tested for the most common clinical chemistry analytes. Lysis was achieved by subjecting whole blood to an overnight freeze-thaw cycle. RESULTS: Hemolysis interference appeared to be approximately linearly dependent on the final concentration of blood-cell lysate in the specimen. This generated a consistent trend towards overestimation of alanine aminotransferase (ALT), aspartate aminotransferase (AST), creatinine, creatine kinase (CK), iron, lactate dehydrogenase (LDH), lipase, magnesium, phosphorus, potassium and urea, whereas mean values of albumin, alkaline phosphatase (ALP), chloride, gamma-glutamyltransferase (GGT), glucose and sodium were substantially decreased. Clinically meaningful variations of AST, chloride, LDH, potassium and sodium were observed in specimens displaying mild or almost undetectable hemolysis by visual inspection (serum hemoglobin < 0.6 g/L). The rather heterogeneous and unpredictable response to hemolysis observed for several parameters prevented the adoption of reliable statistic corrective measures for results on the basis of the degree of hemolysis. CONCLUSION: If hemolysis and blood cell lysis result from an in vitro cause, we suggest that the most convenient corrective solution might be quantification of free hemoglobin, alerting the clinicians and sample recollection.     

Dyspeptic symptoms and gastric emptying in the irritable bowel syndrome

OBJECTIVES: Irritable bowel syndrome (IBS) and dyspepsia often overlap. Delayed gastric emptying has been reported in IBS patients, although conflicting results exist. Whether overlapping dyspepsia correlates with gastric emptying abnormalities in IBS patients has not been clarified. This study aimed to evaluate gastric emptying of solids and its relationship with dyspeptic symptoms in IBS patients. METHODS: A total of 146 IBS outpatients seen in a referral center were evaluated for dyspeptic symptoms using a validated questionnaire. Gastric emptying of solids was evaluated scintigraphically in all patients and in 50 healthy controls. RESULTS: Overlapping dyspepsia was diagnosed in 96 (66%) IBS patients. On average, gastric emptying rates were lower in IBS patients (mean +/- SEM, 33% +/- 1%/h) compared with controls (40% +/- 2%/h; p < 0.01). Specifically, gastric emptying was delayed in IBS patients with overlapping dyspepsia (31% +/- 1%/h; p < 0.01), whereas IBS patients without dyspeptic complaints showed gastric emptying rates (37% +/- 2%/h) that were similar to those of healthy controls (40% +/- 2%/h). Relevant postprandial fullness (OR = 4.7, 95% CI = 1.8-12.5) and relevant nausea (OR = 3.3, 95% CI 1.2-9.3) were independently associated with delayed gastric emptying. CONCLUSIONS: IBS patients without overlapping dyspepsia have normal gastric emptying of solids. A significant association exists in IBS patients between delayed gastric emptying and overlapping relevant postprandial fullness and nausea.