Poly(β-Amino Ester)-Nanoparticle Mediated Transfection of Retinal Pigment Epithelial Cells In Vitro and In Vivo

A variety of genetic diseases in the retina, including retinitis pigmentosa and leber congenital amaurosis, might be excellent targets for gene delivery as treatment. A major challenge in non-viral gene delivery remains finding a safe and effective delivery system. Poly(beta-amino ester)s (PBAEs) have shown great potential as gene delivery reagents because they are easily synthesized and they transfect a wide variety of cell types with high efficacy in vitro. We synthesized a combinatorial library of PBAEs and evaluated them for transfection efficacy and toxicity in retinal pigment epithelial (ARPE-19) cells to identify lead polymer structures and transfection formulations. Our optimal polymer (B5-S5-E7 at 60 w/w polymer∶DNA ratio) transfected ARPE-19 cells with 44±5% transfection efficacy, significantly higher than with optimized formulations of leading commercially available reagents Lipofectamine 2000 (26±7%) and X-tremeGENE HP DNA (22±6%); (p<0.001 for both). Ten formulations exceeded 30% transfection efficacy. This high non-viral efficacy was achieved with comparable cytotoxicity (23±6%) to controls; optimized formulations of Lipofectamine 2000 and X-tremeGENE HP DNA showed 15±3% and 32±9% toxicity respectively (p>0.05 for both). Our optimal polymer was also significantly better than a gold standard polymeric transfection reagent, branched 25 kDa polyethyleneimine (PEI), which achieved only 8±1% transfection efficacy with 25±6% cytotoxicity. Subretinal injections using lyophilized GFP-PBAE nanoparticles resulted in 1.1±1×103-fold and 1.5±0.7×103-fold increased GFP expression in the retinal pigment epithelium (RPE)/choroid and neural retina respectively, compared to injection of DNA alone (p = 0.003 for RPE/choroid, p<0.001 for neural retina). The successful transfection of the RPE in vivo suggests that these nanoparticles could be used to study a number of genetic diseases in the laboratory with the potential to treat debilitating eye diseases

Patients’ willingness to attend the NHS cardiovascular health checks in primary care: A qualitative interview study

Background: The NHS Cardiovascular Health Check (NHSHC) programme was introduced in England in 2009 to reduce cardiovascular disease mortality and morbidity for all patients aged 40 to 74 years old. Programme cost-effectiveness was based on an assumed uptake of 75% but current estimates of uptake in primary care are less than 50%. The purpose of this study was to identify factors influencing patients’ willingness to attend an NHSHC. For those who attended, their views, experiences and their future willingness to engage in the programme were explored. Method: Telephone or face-to-face interviews were conducted with patients who had recently been invited for an NHSHC by a letter from four general practices in Torbay, England. Patients were purposefully sampled (by gender, age, attendance status). Interviews were audio recorded, transcribed verbatim and analysed thematically. Results: 17 attendees and 10 non-attendees were interviewed. Patients who attended an NHSHC viewed it as worthwhile. Proactive attitudes towards their health, a desire to prevent disease before they developed symptoms, and a willingness to accept screening and health check invitations motivated many individuals to attend. Non-attendees cited not seeing the NHSHC as a priority, or how it differed from regular monitoring already received for other conditions as barriers to attendance. Some non-attendees actively avoided GP practices when feeling well, while others did not want to waste health professionals’ time. Misunderstandings of what the NHSHC involved and negative views of what the likely outcome might be were common. Conclusion: While a minority of non-attendees simply had made an informed choice not to have an NHSHC, improving the clarity and brevity of invitational materials, better advertising, and simple administrative interventions such as sending reminder letters, have considerable potential to improve NHSHC uptake

Bayesian molecular clock dating of species divergences in the genomics era

It has been five decades since the proposal of the molecular clock hypothesis, which states that the rate of evolution at the molecular level is constant through time and among species. This hypothesis has become a powerful tool in evolutionary biology, making it possible to use molecular sequences to estimate the geological ages of species divergence events. With recent advances in Bayesian clock dating methodology and the explosive accumulation of genetic sequence data, molecular clock dating has found widespread applications, from tracking virus pandemics, to studying the macroevolutionary process of speciation and extinction, to estimating a timescale for Life on Earth

Riesgo cardiovascular en estudiantes de medicina del municipio Puerto Padre de Las Tunas

Introduction: cardiovascular diseases are the first cause of death in Cuba; as a result, the identification of cardiovascular risks from early ages allows the implementation of health promotion and prevention strategies to reduce their impact in the futureObjective: to identify the cardiovascular risk in medical students in Puerto Padre Municipality, Las Tunas province.Methods: an observational, descriptive and cross-sectional study was conducted. The target group included 545 medical students, 237 of whom were selected by means of a simple random sample. The body mass index and waist-hip ratio were studied. Descriptive statistics was applied.Results: the predominant age group was 18-21 years old (50,2 %). The 51,47 % of the students presented a high waist-hip ratio, 54,02 % a high abdominal circumference, 52,74 % a high body mass index, and in all groups 35,44 % presented blood pressure figures lower than 120/80 mmHg; 39 % had a cardiovascular risk.Conclusions: low percentages of cardiovascular risk were identified in medical students from Puerto Padre Municipality, Las Tunas province, determined by high values of waist-hip index, body mass index and abdominal circumference.Introducción: las enfermedades cardiovasculares constituyen la primera causa de mortalidad en Cuba; por lo cual la identificación de riesgos cardiovasculares desde edades tempranas permite implementar estrategias de promoción y prevención de salud para disminuir su impacto en el futuroObjetivo: identificar el riesgo cardiovascular en estudiantes de medicina del municipio Puerto Padre de Las Tunas.Método: se realizó un estudio observacional, descriptivo y transversal. El universo estuvo constituido por 545 estudiantes de medicina, seleccionándose 237 mediante un muestreo aleatorio simple. Se estudió el índice de masa corporal, la circunferencia abdominal y la índice cintura cadera. Se empleó estadística descriptiva.Resultados: se encontró predominio del grupo etario de 18 a 21 años (50,2 %). El 51,47 % de los estudiantes presentó un índice cintura-cadera alto, el 54,02 % una circunferencia abdominal alta, el 52,74 % un índice de masa corporal alta, así como en todos los grupos el 35,44 % presentó cifras de tensión arterial inferiores a 120/80 mmHg. El 39 % presentó riesgo cardiovascular.Conclusiones: se identificaron bajos porcientos de riesgo cardiovascular en los estudiantes de medicina del municipio Puerto Padre de Las Tunas, determinado por altos valores los índice cintura-cadera, índice de masa corporal y circunferencia abdominal

Association of Leisure-Time Physical Activity With Risk of 26 Types of Cancer in 1.44 Million Adults

Importance Leisure-time physical activity has been associated with lower risk of heart-disease and all-cause mortality, but its association with risk of cancer is not well understood. Objective To determine the association of leisure-time physical activity with incidence of common types of cancer and whether associations vary by body size and/or smoking. Design, Setting, and Participants We pooled data from 12 prospective US and European cohorts with self-reported physical activity (baseline, 1987-2004). We used multivariable Cox regression to estimate hazard ratios (HRs) and 95% confidence intervals for associations of leisure-time physical activity with incidence of 26 types of cancer. Leisure-time physical activity levels were modeled as cohort-specific percentiles on a continuous basis and cohort-specific results were synthesized by random-effects meta-analysis. Hazard ratios for high vs low levels of activity are based on a comparison of risk at the 90th vs 10th percentiles of activity. The data analysis was performed from January 1, 2014, to June 1, 2015. Exposures Leisure-time physical activity of a moderate to vigorous intensity. Main Outcomes and Measures Incident cancer during follow-up. Results A total of 1.44 million participants (median [range] age, 59 [19-98] years; 57% female) and 186 932 cancers were included. High vs low levels of leisure-time physical activity were associated with lower risks of 13 cancers: esophageal adenocarcinoma (HR, 0.58; 95% CI, 0.37-0.89), liver (HR, 0.73; 95% CI, 0.55-0.98), lung (HR, 0.74; 95% CI, 0.71-0.77), kidney (HR, 0.77; 95% CI, 0.70-0.85), gastric cardia (HR, 0.78; 95% CI, 0.64-0.95), endometrial (HR, 0.79; 95% CI, 0.68-0.92), myeloid leukemia (HR, 0.80; 95% CI, 0.70-0.92), myeloma (HR, 0.83; 95% CI, 0.72-0.95), colon (HR, 0.84; 95% CI, 0.77-0.91), head and neck (HR, 0.85; 95% CI, 0.78-0.93), rectal (HR, 0.87; 95% CI, 0.80-0.95), bladder (HR, 0.87; 95% CI, 0.82-0.92), and breast (HR, 0.90; 95% CI, 0.87-0.93). Body mass index adjustment modestly attenuated associations for several cancers, but 10 of 13 inverse associations remained statistically significant after this adjustment. Leisure-time physical activity was associated with higher risks of malignant melanoma (HR, 1.27; 95% CI, 1.16-1.40) and prostate cancer (HR, 1.05; 95% CI, 1.03-1.08). Associations were generally similar between overweight/obese and normal-weight individuals. Smoking status modified the association for lung cancer but not other smoking-related cancers. Conclusions and Relevance Leisure-time physical activity was associated with lower risks of many cancer types. Health care professionals counseling inactive adults should emphasize that most of these associations were evident regardless of body size or smoking history, supporting broad generalizability of findings