Neighbourhood Walkability and Its Influence on Physical Activity and Cardiometabolic Disease: A Cross-Sectional Study in a Caribbean Small Island Developing State.

Introduction Cities and neighborhoods may provide opportunities for population-level environmental interventions to reduce physical inactivity and cardiometabolic risk. In this study, we describe the association between neighborhood walkability, physical activity (PA), and cardiometabolic outcomes, by linking data from a nationally representative survey of adults (25 years and older) collected in 2012-2013 with spatial data on built environment features in Barbados. Methods We estimated a walkability index for 45 neighborhoods using objectively measured built environment features (residential density, street connectivity, and land use mix). We used the Recent Physical Activity Questionnaire to capture time spent in outdoor walking, active commuting, moderate-to-vigorous PA (MVPA), and total PA. Our primary cardiometabolic outcome was a predicted 10-year cardiovascular risk (CVD) score, estimated using the American College of Cardiology/American Heart Association pooled cohort equation. Our secondary cardiometabolic outcomes were hypertension and diabetes. We explored the effect of neighborhood walkability on PA and cardiometabolic outcomes using several multivariable regression models (tobit and linear and logistic multi-level mixed effects), with the model choice depending on the structure of the outcome.  Results The average time spent walking weekly for any purpose among participants was 75 minutes/week, time spent on active commuting was 15 minutes/week, and MVPA was 221 minutes/week. We estimated that the average 10-year CVD risk in the study population was 11.7% (95%CI 10.9-12.5). Our confounder-adjusted analyses showed positive linear relationships between neighborhood walkability and each PA outcome (p<0.05 in all cases), and a negative relationship between walkability and predicted 10-year CVD risk (p<0.001). Conclusion In our setting, adults residing in higher walkability neighborhoods spent more time engaged in PA, had a lower predicted 10-year CVD risk, and were less likely to have diabetes. Urban planners may consider shorter-term interventions, such as those on a microscale, which may provide additional ways to increase activity in a mostly fixed macroscale environment.

Preexposure Prophylaxis in Latin America and the Caribbean-The Barbados Experience.

This study explored oral pre-exposure prophylaxis (PrEP) awareness, and sexual behavior of gay, bisexual, and other men who have sex with men (gbMSM) in Barbados. Factors associated with PrEP use were examined using Pearson chi-square and logistic regression. Of the 171 male participants who completed the survey, 22% were under 25 years old, 70% identified as gay/homosexual, and 59% were single. PrEP awareness was 77%, and of these 29% were current PrEP users. Users were more likely to have stable living arrangements (p < .05) and to identify as gay/homosexual (p=.03). Uptake by current PrEP users was attributed to non-judgmental and confidential PrEP services. Barriers identified by former PrEP users included cost and risks of STIs. Since the PrEP program is free, as is general health care for STIs, this suggests that there may be a knowledge gap. Further studies are needed to explore perceived barriers to the program.

A biophysical framework for double-drugging kinases.

Orthosteric inhibition of kinases has been challenging due to the conserved active site architecture of kinases and emergence of resistance mutants. Simultaneous inhibition of distant orthosteric and allosteric sites, which we refer to as "double-drugging", has recently been shown to be effective in overcoming drug resistance. However, detailed biophysical characterization of the cooperative nature between orthosteric and allosteric modulators has not been undertaken. Here, we provide a quantitative framework for double-drugging of kinases employing isothermal titration calorimetry, Förster resonance energy transfer, coupled-enzyme assays, and X-ray crystallography. We discern positive and negative cooperativity for Aurora A kinase (AurA) and Abelson kinase (Abl) with different combinations of orthosteric and allosteric modulators. We find that a conformational equilibrium shift is the main principle governing this cooperative effect. Notably, for both kinases, we find a synergistic decrease of the required orthosteric and allosteric drug dosages when used in combination to inhibit kinase activities to clinically relevant inhibition levels. X-ray crystal structures of the doubledrugged kinase complexes reveal the molecular principles underlying the cooperative nature of double-drugging AurA and Abl with orthosteric and allosteric inhibitors. Finally, we observe the first fully-closed conformation of Abl when bound to a pair of positively cooperative orthosteric and allosteric modulators, shedding light onto the puzzling abnormality of previously solved closed Abl structures. Collectively, our data provide mechanistic and structural insights into rational design and evaluation of doubledrugging strategies.

COVID-19 and the social distribution of hunger in three Caribbean Small Island Developing States.

Objectives: To determine changes to income and livelihood, food consumption, and hunger due to coronavirus disease 2019 (COVID-19) in three Small Island Developing States (SIDS) in the Caribbean: Jamaica, St Kitts and Nevis, and St Vincent and the Grenadines. Methods: This was a cross-sectional study conducted in July 2020. Participants were selected using telephone directories and lists of mobile numbers. Data were collected through face-to-face and telephone interviews. Participants rated the impact of COVID-19 on their livelihoods and the Adult Food Security Module was used to assess hunger. To examine how these outcomes varied by sociodemographic group, multivariable logistic regression analysis was used, with odds ratios (OR) and 95% confidence intervals (CI) reported. Results: The analysis included 880 participants. Of these, 40% (344/871) reported some form of hunger, with 18% (153/871) classed as moderate-to-severe hunger. Almost three quarters of households reported some impact on their livelihood (640/880), with 28% (243/880) classifying this impact as moderate to severe. Women were 60% more likely to report that their livelihoods were moderately to severely affected by COVID-19 (OR 1.59; 95% CI 1.09, 2.31) and 70% more likely to experience moderate-to-severe hunger (OR 1.70; 95% CI 1.37, 2.09). The effects of COVID-19 on livelihood and hunger were greater in those with secondary-school and primary-school education compared with tertiary education. Conclusion: The COVID-19 pandemic is disproportionately affecting the most vulnerable segments of the population. Social protection programmes are a key component of efforts to alleviate the pandemic's consequences; however, equitable access must be ensured.

COVID-19 and the social distribution of hunger in three Caribbean Small Island Developing States

[ABSTRACT]. Objectives. To determine changes to income and livelihood, food consumption, and hunger due to coronavirus disease 2019 (COVID-19) in three Small Island Developing States (SIDS) in the Caribbean: Jamaica, St Kitts and Nevis, and St Vincent and the Grenadines. Methods. This was a cross-sectional study conducted in July 2020. Participants were selected using telephone directories and lists of mobile numbers. Data were collected through face-to-face and telephone interviews. Participants rated the impact of COVID-19 on their livelihoods and the Adult Food Security Module was used to assess hunger. To examine how these outcomes varied by sociodemographic group, multivariable logistic regression analysis was used, with odds ratios (OR) and 95% confidence intervals (CI) reported. Results. The analysis included 880 participants. Of these, 40% (344/871) reported some form of hunger, with 18% (153/871) classed as moderate-to-severe hunger. Almost three quarters of households reported some impact on their livelihood (640/880), with 28% (243/880) classifying this impact as moderate to severe. Women were 60% more likely to report that their livelihoods were moderately to severely affected by COVID-19 (OR 1.59; 95% CI 1.09, 2.31) and 70% more likely to experience moderate-to-severe hunger (OR 1.70; 95% CI 1.37, 2.09). The effects of COVID-19 on livelihood and hunger were greater in those with secondary-school and primary-school education compared with tertiary education. Conclusion. The COVID-19 pandemic is disproportionately affecting the most vulnerable segments of the population. Social protection programmes are a key component of efforts to alleviate the pandemic’s consequences; however, equitable access must be ensured.

[RESUMEN]. Objetivos. Determinar qué cambios ha ocasionado la enfermedad por el coronavirus del 2019 (COVID-19) en los ingresos y los medios de subsistencia, el consumo de alimentos y el hambre en tres pequeños Estados insulares en desarrollo del Caribe: Jamaica, Saint Kitts y Nevis, y San Vicente y las Granadinas. Métodos. En este estudio transversal realizado en julio del 2020, para seleccionar a los participantes se utilizaron guías telefónicas y listas de números de teléfono celular. Los datos se recopilaron mediante entrevistas en persona y por teléfono. Los participantes calificaron cuál había sido la repercusión de la COVID-19 en sus medios de subsistencia; el hambre se evaluó mediante la escala de la encuesta sobre seguridad alimentaria en los hogares “Adult Food Security Module”. Para estudiar cómo variaban los resultados según el grupo sociodemográfico, se realizó un análisis de regresión logística multivariable, con razones de probabilidades (odds ratios u OR) e intervalos de confianza de 95% (IC). Resultados. El análisis incluyó a 880 participantes. De estos, 40% (344/871) declararon haber pasado algún grado de hambre y 18% (153/871) lo calificaron de moderado a grave. Casi tres cuartos de los hogares informaron que sus medios de subsistencia habían tenido algún tipo de repercusión (640/880) y 28% (243/880) la calificaron de moderada a grave. Las mujeres tenían un 60% más de probabilidades de valorar la repercusión de la COVID-19 en sus medios de subsistencia de moderada a grave (OR 1,59; IC de 95% 1,09, 2,31) y un 70% más de probabilidades de haber tenido un nivel de hambre de moderado a grave (OR 1,70; IC de 95% 1,37, 2,09). Los efectos de la COVID-19 sobre los medios de subsistencia y el hambre fueron mayores en aquellos participantes con educación primaria y secundaria en comparación con aquellos con educación terciaria. Conclusión. La pandemia de COVID-19 está afectando desproporcionadamente a los segmentos más vulnerables de la población. Los programas de protección social son un componente clave de las iniciativas dirigidas a paliar las consecuencias de la pandemia; sin embargo, debe garantizarse que el acceso a estos programas es equitativo.

[RESUMO]. Objetivos. Determinar mudanças na renda e na subsistência, no consumo de alimentos e na fome devido à doença causada pelo coronavírus 2019 (COVID-19) em três pequenos Estados insulares em desenvolvimento (SIDS, na sigla em inglês) no Caribe: Jamaica, São Cristóvão e Névis, e São Vicente e Granadinas. Métodos. Este foi um estudo transversal realizado em julho de 2020. Os participantes foram selecionados por meio da utilização de listas telefônicas e números de celular. Os dados foram coletados por meio de entrevistas presenciais e telefônicas. Os participantes avaliaram o impacto da COVID-19 em seus meios de subsistência, e o módulo de segurança alimentar para adultos foi utilizado para avaliar a fome. Para examinar como esses resultados variavam por grupo sociodemográfico, foi utilizada a análise de regressão logística multivariável, com razões de chances (RC) e intervalos de confiança (IC) relatados de 95%. Resultados. A análise incluiu 880 participantes. Entre eles, 40% (344/871) relataram alguma forma de fome, com 18% (153/871) classificados como fome moderada a grave. Quase três quartos das famílias relataram algum impacto em sua subsistência (640/880), com 28% (243/880) classificando esse impacto como moderado a grave. As mulheres tiveram 60% mais probabilidade de relatar que seus meios de subsistência foram afetados moderada a gravemente pela COVID-19 (RC 1,59; IC 95% 1,09, 2,31) e 70% mais probabilidade de passar fome de moderada a grave (RC 1,70; IC 95% 1,37, 2,09). Os efeitos da COVID-19 sobre a subsistência e a fome foram maiores nas pessoas com ensino fundamental e médio, em comparação com o ensino superior. Conclusão. A pandemia de COVID-19 está afetando de forma desproporcional os segmentos mais vulneráveis da população. Programas de proteção social são um componente essencial dos esforços para aliviar as consequências da pandemia; entretanto, o acesso equitativo deve ser garantido.

Physical activity and disordered eating behaviours: Are Caribbean adolescents at risk?

Excessive physical activity (PA) has been linked to increased risk for disordered eating behaviours and eating disorders. This study investigates the relationship between PA and disordered eating behaviours and attitudes (DEBAs) among Jamaican adolescents. This cross-sectional study included 521 adolescents, 12-19 years. Anthropometric measurements were collected, and adolescents completed questionnaires on disordered eating behaviours (EAT-26), physical activity, self-esteem and affect. Associations were assessed using sex-specific mixed-effect linear and logistic regression models. Participants reported exercising an average of 3 days per week. Adolescents who exercised for a longer duration had greater odds of having elevated EAT-26 scores (at least 1 hour-OR = 2.04; 95% CI = 1.03, 4.06; p = .042), while a higher exercise frequency among males (3-5 days per week) was protective against DEBAs (OR 0.38; 95% CI = 0.16, 0.88; p = .025). Female adolescents reported higher prevalence of elevated EAT-26 scores than males (p < .01). Increased negative affect increased odds of an elevated EAT-26 score. Exercise duration and frequency play a role in disordered eating behaviours in Jamaican adolescents and vary by gender. Our findings have implications for weight management interventions and policies, encouraging healthcare providers to monitor PA levels as well as negative affect in adolescents who display disordered eating behaviours.

COVID-19 and the social distribution of hunger in three Caribbean Small Island Developing States / La COVID-19 y la distribución social del hambre en tres pequeños Estados insulares en desarrollo del Caribe / COVID-19 e a distribuição social da fome em três pequenos Estados insulares em desenvolvimento do Caribe

ABSTRACT Objectives. To determine changes to income and livelihood, food consumption, and hunger due to coronavirus disease 2019 (COVID-19) in three Small Island Developing States (SIDS) in the Caribbean: Jamaica, St Kitts and Nevis, and St Vincent and the Grenadines. Methods. This was a cross-sectional study conducted in July 2020. Participants were selected using telephone directories and lists of mobile numbers. Data were collected through face-to-face and telephone interviews. Participants rated the impact of COVID-19 on their livelihoods and the Adult Food Security Module was used to assess hunger. To examine how these outcomes varied by sociodemographic group, multivariable logistic regression analysis was used, with odds ratios (OR) and 95% confidence intervals (CI) reported. Results. The analysis included 880 participants. Of these, 40% (344/871) reported some form of hunger, with 18% (153/871) classed as moderate-to-severe hunger. Almost three quarters of households reported some impact on their livelihood (640/880), with 28% (243/880) classifying this impact as moderate to severe. Women were 60% more likely to report that their livelihoods were moderately to severely affected by COVID-19 (OR 1.59; 95% CI 1.09, 2.31) and 70% more likely to experience moderate-to-severe hunger (OR 1.70; 95% CI 1.37, 2.09). The effects of COVID-19 on livelihood and hunger were greater in those with secondary-school and primary-school education compared with tertiary education. Conclusion. The COVID-19 pandemic is disproportionately affecting the most vulnerable segments of the population. Social protection programmes are a key component of efforts to alleviate the pandemic's consequences; however, equitable access must be ensured.

RESUMEN Objetivos. Determinar qué cambios ha ocasionado la enfermedad por el coronavirus del 2019 (COVID-19) en los ingresos y los medios de subsistencia, el consumo de alimentos y el hambre en tres pequeños Estados insulares en desarrollo del Caribe: Jamaica, Saint Kitts y Nevis, y San Vicente y las Granadinas. Métodos. En este estudio transversal realizado en julio del 2020, para seleccionar a los participantes se utilizaron guías telefónicas y listas de números de teléfono celular. Los datos se recopilaron mediante entrevistas en persona y por teléfono. Los participantes calificaron cuál había sido la repercusión de la COVID-19 en sus medios de subsistencia; el hambre se evaluó mediante la escala de la encuesta sobre seguridad alimentaria en los hogares "Adult Food Security Module". Para estudiar cómo variaban los resultados según el grupo sociodemográfico, se realizó un análisis de regresión logística multivariable, con razones de probabilidades (odds ratios u OR) e intervalos de confianza de 95% (IC). Resultados. El análisis incluyó a 880 participantes. De estos, 40% (344/871) declararon haber pasado algún grado de hambre y 18% (153/871) lo calificaron de moderado a grave. Casi tres cuartos de los hogares informaron que sus medios de subsistencia habían tenido algún tipo de repercusión (640/880) y 28% (243/880) la calificaron de moderada a grave. Las mujeres tenían un 60% más de probabilidades de valorar la repercusión de la COVID-19 en sus medios de subsistencia de moderada a grave (OR 1,59; IC de 95% 1,09, 2,31) y un 70% más de probabilidades de haber tenido un nivel de hambre de moderado a grave (OR 1,70; IC de 95% 1,37, 2,09). Los efectos de la COVID-19 sobre los medios de subsistencia y el hambre fueron mayores en aquellos participantes con educación primaria y secundaria en comparación con aquellos con educación terciaria. Conclusión. La pandemia de COVID-19 está afectando desproporcionadamente a los segmentos más vulnerables de la población. Los programas de protección social son un componente clave de las iniciativas dirigidas a paliar las consecuencias de la pandemia; sin embargo, debe garantizarse que el acceso a estos programas es equitativo.

RESUMO Objetivos. Determinar mudanças na renda e na subsistência, no consumo de alimentos e na fome devido à doença causada pelo coronavírus 2019 (COVID-19) em três pequenos Estados insulares em desenvolvimento (SIDS, na sigla em inglês) no Caribe: Jamaica, São Cristóvão e Névis, e São Vicente e Granadinas. Métodos. Este foi um estudo transversal realizado em julho de 2020. Os participantes foram selecionados por meio da utilização de listas telefônicas e números de celular. Os dados foram coletados por meio de entrevistas presenciais e telefônicas. Os participantes avaliaram o impacto da COVID-19 em seus meios de subsistência, e o módulo de segurança alimentar para adultos foi utilizado para avaliar a fome. Para examinar como esses resultados variavam por grupo sociodemográfico, foi utilizada a análise de regressão logística multivariável, com razões de chances (RC) e intervalos de confiança (IC) relatados de 95%. Resultados. A análise incluiu 880 participantes. Entre eles, 40% (344/871) relataram alguma forma de fome, com 18% (153/871) classificados como fome moderada a grave. Quase três quartos das famílias relataram algum impacto em sua subsistência (640/880), com 28% (243/880) classificando esse impacto como moderado a grave. As mulheres tiveram 60% mais probabilidade de relatar que seus meios de subsistência foram afetados moderada a gravemente pela COVID-19 (RC 1,59; IC 95% 1,09, 2,31) e 70% mais probabilidade de passar fome de moderada a grave (RC 1,70; IC 95% 1,37, 2,09). Os efeitos da COVID-19 sobre a subsistência e a fome foram maiores nas pessoas com ensino fundamental e médio, em comparação com o ensino superior. Conclusão. A pandemia de COVID-19 está afetando de forma desproporcional os segmentos mais vulneráveis da população. Programas de proteção social são um componente essencial dos esforços para aliviar as consequências da pandemia; entretanto, o acesso equitativo deve ser garantido.

The Impact of a Ketogenic Dietary Intervention on the Quality of Life of Stage II and III Cancer Patients: A Randomized Controlled Trial in the Caribbean.

INTRODUCTION: This study sought to determine the impact of a ketogenic dietary intervention on the quality of life of stage II and III cancer patients. METHODS: A randomized controlled trial was implemented whereby patients in the treatment group followed a modified ketogenic diet (KD) utilizing medium chained triglyceride fats during a four-month period, while the control group followed an institutionalized standard traditional diet. Quality of life and mental health status was assessed using The European Organization for Research and Treatment of Cancer current core questionnaire and The Patient Health Questionnaire. Intervention effects were assessed using repeated measures ANCOVA and multiple linear regression models. RESULTS: The quality of life and mental health of the cancer patients in the treatment group were greatly increased and improved due to the utilization of the diet. Most of the persons in the treatment group attained and maintained ketosis after 2 weeks. Age, gender, and state of the disease seemed to affect the keto-adaptation period in terms of the time taken to keto-adapt. CONCLUSION: The KD was suitable for stage II and III cancer patients in improving their quality of life, nutritional, functional, and psychosocial statuses.

Colorectal Cancer Knowledge and Awareness Among University Students in a Caribbean Territory: a Cross-sectional Study.

INTRODUCTION: The burden of colorectal cancer (CRC) has been on the rise globally over the last decade. Several studies point to the fact that there is a lack of knowledge and awareness for CRC which may be attributed to the increase in the burden over time. Therefore, we aimed to assess the level and predictors for knowledge of CRC and its risk factors. METHODS: This study was a cross-sectional study conducted on the student population of the University of the West Indies, St. Augustine Campus, Trinidad. We assessed CRC knowledge using scales examining their level of knowledge for CRC and its risk factors. Lifestyle behaviors (smoking, physical activity, dietary behaviors, and alcohol consumption) and perceived risk for developing CRC were also collected using a standard survey. Predictors for CRC knowledge were assessed using forward stepwise linear and logistic regression models. RESULTS: The overall CRC knowledge was 54.740% ± 19.721%. Poor knowledge levels were seen among 36.23% while satisfactory/good knowledge was seen among 63.77%. Predictors of poor CRC knowledge were males (OR = 1.559; p = 0.003), frequent/excessive alcoholic drinkers (OR = 1.924; p = 0.029), and low physical activity (OR = 1.331; p = 0.042). Predictors of satisfactory/good CRC knowledge were those with higher scores for the prudent dietary pattern (OR = 0.893; p = 0.016), and compared with those who reported no risk, participants reporting low risk had an increased likelihood of obtaining good CRC knowledge scores (OR = 0.526; p = < 0.001) and high risk (0.310; p = < 0.001). CONCLUSION: The level of awareness/knowledge on CRC and its risk factors is low. Improvement of CRC awareness and healthy lifestyle campaigns among young adults is needed for the Caribbean region.

Disordered eating behaviours and attitudes among adolescents in a middle-income country.

PURPOSE: Adolescent-disordered eating behaviours and attitudes (DEBA) are noted to be increasing in prevalence internationally. The aim of this study was to explore the DEBAs among Jamaican adolescents and identify those adolescents most at risk. METHODS: 521 high school participants (females, n = 292), ages 11-19 years, completed measures assessing socio-demographic factors, self-esteem, symptoms of anxiety and depression, behavioural factors, and anthropometry. Weight-related behaviours and attitudes were explored using the Eating Attitudes Test (EAT-26). RESULTS: Thirty-one percent of participants reported engaging in at least one disordered eating behaviour, with bingeing as the most common. Female participants had significantly higher mean body mass index (p < 0.01) and mean EAT-26 score (p < 0.05) compared to males. Adolescents with EAT-26 score ≥ 20 were more desirous of being thinner (p < 0.01) and having a lighter skin complexion (p < 0.05). A greater proportion of adolescents with an EAT-26 score ≥ 20 had engaged in self-harm (p < 0.05), had smoked cigarettes (p < 0.05), had been sexually active (p < 0.01), and gave a history of sexual abuse (p < 0.01). Adolescents with overweight/obesity reported higher use of chemical weight manipulation (laxatives, diuretics, and diet pills) (p = 0.01). CONCLUSIONS: Our data are consistent with the global figures showing both male and female adolescents endorsing disordered eating behaviours and attitudes (DEBAs). While this study highlights weight and shape dissatisfaction and associated DEBAs, it also raises the concern of an association with skin bleaching and elevated EAT-26 scores among Jamaican adolescents. LEVEL OF EVIDENCE: Level V: cross-sectional descriptive study.

Mapping the electric field distribution of tightly focused cylindrical vector beams with gold nanorings.

In this paper gold nanorings (NRs) are applied as particularly well-suited sensing elements for mapping the radially symmetric electric fields in the high numerical aperture focus of cylindrical vector beams. The optical properties of gold nanorings are analyzed by a combination of extinction and single particle dark field spectroscopy as well as confocal photoluminescence (PL) imaging. The results are compared to numerical calculations. The in-plane components in the focus of the cylindrical vector beams are estimated through the PL intensity distributions of the NRs. The optimum overlap between the structure and excitation is visualized by a narrow centre spot in the far-field PL scan.

Parallel substrate supply and pH stabilization for optimal screening of E. coli with the membrane-based fed-batch shake flask.

BACKGROUND: Screening in the fed-batch operation mode is essential for biological cultivations facing challenges as oxygen limitation, osmotic inhibition, catabolite repression, substrate inhibition or overflow metabolism. As a screening tool on shake flask level, the membrane-based fed-batch shake flask was developed. While a controlled supply of a substrate was realized with the in-built membrane tip, the possibilities for replenishing nutrients and stabilizing pH values was not yet exploited. High buffer concentrations were initially used, shifting the medium osmolality out of the biological optimum. As the growth rate is predefined by the glucose release kinetics from the reservoir, the resulting medium acidification can be compensated with a controlled continuous supply of an alkaline compound. The focus of this research is to establish a simultaneous multi-component release of glucose and an alkaline compound from the reservoir to enable cultivations within the optimal physiological range of Escherichia coli. RESULTS: In combination with the Respiratory Activity MOnitoring System, the membrane-based fed-batch shake flask enabled the detection of an ammonium limitation. The multi-component release of ammonium carbonate along with glucose from the reservoir resulted not only in the replenishment of the nitrogen source but also in the stabilization of the pH value in the culture medium. A biomass concentration up to 25 g/L was achieved, which is one of the highest values obtained so far to the best of the author's knowledge with the utilization of a shake flask and a defined synthetic medium. Going a step further, the pH stabilization allowed the decrease of the required buffer amount to one-fourth establishing an optimal osmolality range for cultivation. As optimal physiological conditions were implemented with the multi-component release fed-batch cultivation, the supply of 0.2 g glucose in a 10 mL initial culture medium volume with 50 mM MOPS buffer resulted in a twofold higher biomass concentration than in a comparable batch cultivation. CONCLUSIONS: The newly introduced multi-component release with the membrane-based fed-batch shake flask serves a threefold purpose of replenishing depleted substrates in the culture medium, stabilizing the pH throughout the entire cultivation time and minimizing the necessary amount of buffer to maintain an optimal osmolality range. In comparison to a batch cultivation, these settings enable to achieve higher biomass and product concentrations.

Compact plasmonic optical biosensors based on nanostructured gradient index lenses integrated into microfluidic cells.

We report on a compact and cost-effective integrated label-free biosensor configuration which is based on the refractive index sensitivity of the localized surface plasmon resonance (LSPR) of gold nanostructures. Aiming for compactification and miniaturization of the sensor, arrays of nanodiscs were fabricated on the planar surface of a gradient index (GRIN) lens, which acts as a substrate as well as an imaging objective for the light scattered by the gold structures. Integration of the lens into a microfluidic flow cell enabled the controlled exchange of liquid media at the sensor surface. The light scattered by the nanostructures was investigated spatially and spectrally resolved making use of the imaging properties of the GRIN lens. Dynamic spectral analysis during refractive index changes was conducted, revealing high sensitivities of up to 372 nm per refractive index unit for the shift of the LSPR. Biosensing capabilities were demonstrated by the detection of binding of an analyte by means of a testosterone-immunoassay.

Systematic evaluation of characteristics of the membrane-based fed-batch shake flask.

BACKGROUND: The initial part of process development involves extensive screening programs to identify optimal biological systems and cultivation conditions. For a successful scale-up, the operation mode on screening and production scale must be as close as possible. To enable screening under fed-batch conditions, the membrane-based fed-batch shake flask was developed. It is a shake flask mounted with a central feed reservoir with an integrated rotating membrane tip for a controlled substrate release. Building on the previously provided proof of principle for this tool, this work extends its application by constructive modifications and improved methodology to ensure reproducible performance. RESULTS: The previously limited operation window was expanded by a systematic analysis of reservoir set-up variations for cultivations with the fast-growing organism Escherichia coli. Modifying the initial glucose concentration in the reservoir as well as interchanging the built-in membrane, resulted in glucose release rates and oxygen transfer rate levels during the fed-batch phase varying up to a factor of five. The range of utilizable membranes was extended from dialysis membranes to porous microfiltration membranes with the design of an appropriate membrane tip. The alteration of the membrane area, molecular weight cut-off and liquid volume in the reservoir offered additional parameters to fine-tune the duration of the initial batch phase, the oxygen transfer rate level of the fed-batch phase and the duration of feeding. It was shown that a homogeneous composition of the reservoir without a concentration gradient is ensured up to an initial glucose concentration of 750 g/L. Finally, the experimental validity of fed-batch shake flask cultivations was verified with comparable results obtained in a parallel fed-batch cultivation in a laboratory-scale stirred tank reactor. CONCLUSIONS: The membrane-based fed-batch shake flask is a reliable tool for small-scale screening under fed-batch conditions filling the gap between microtiter plates and scaled-down stirred tank reactors. The implemented reservoir system offers various set-up possibilities, which provide a wide range of process settings for diverse biological systems. As a screening tool, it accurately reflects the cultivation conditions in a fed-batch stirred tank reactor and enables a more efficient bioprocess development.

Autoimmune hemolytic anemia in systemic lupus erythematosus at diagnosis: differences between pediatric and adult patients.

Objective To determine the overall prevalence of autoimmune hemolytic anemia (AIHA), and to compare clinical and laboratory features in a large population of children and adult lupus patients at diagnosis. Methods This retrospective study evaluated the medical charts of 336 childhood-onset systemic lupus erythematosus (cSLE) and 1830 adult SLE (aSLE) patients followed in the same tertiary hospital. Demographic data, clinical features and disease activity were recorded. AIHA was defined according to the presence of anemia (hemoglobin <10 g/dL) and evidence of hemolysis (reticulocytosis and positive direct antiglobulin test (DAT)/Coombs test) at SLE diagnosis. Evans syndrome (ES) was defined by the combination of immune thrombocytopenia (platelet count <100,000/mm3) and AIHA. Results The frequency of AIHA at diagnosis was significantly higher in cSLE patients compared to aSLE (49/336 (14%) vs 49/1830 (3%), p = 0.0001), with similar frequency of ES (3/336 (0.9%) vs 10/1830 (0.5%), p = 0.438). The median of hemoglobin levels was reduced in cSLE vs aSLE patients (8.3 (2.2-10) vs 9.5 (6.6-10) g/dL, p = 0.002) with a higher frequency of multiple hemorrhagic manifestations (41% vs 7%, p = 0.041) and erythrocyte transfusion due to bleeding (24% vs 5%, p = 0.025). cSLE patients also had more often constitutional involvement (84% vs 31%, p < 0.001), fever (65% vs 26%, p < 0.001), weight loss > 2 kg (39% vs 6%, p < 0.001), reticuloendothelial manifestations (48% vs 8%, p < 0.001), hepatomegaly (25% vs 2%, p < 0.001) and splenomegaly (21% vs 2%, p = 0.004). Other major organ involvements were common but with similar frequencies in cSLE and aSLE ( p > 0.05). Median systemic lupus erythematosus disease activity index 2000 (SLEDAI-2 K) was comparable in cSLE and aSLE (p = 0.161). Conclusions We identified that AIHA was not a common condition in cSLE and aSLE, with distinct features characterized by a higher prevalence/severity in children and concomitant constitutional symptoms in the majority of them.

Free energy landscape of activation in a signalling protein at atomic resolution.

The interconversion between inactive and active protein states, traditionally described by two static structures, is at the heart of signalling. However, how folded states interconvert is largely unknown due to the inability to experimentally observe transition pathways. Here we explore the free energy landscape of the bacterial response regulator NtrC by combining computation and nuclear magnetic resonance, and discover unexpected features underlying efficient signalling. We find that functional states are defined purely in kinetic and not structural terms. The need of a well-defined conformer, crucial to the active state, is absent in the inactive state, which comprises a heterogeneous collection of conformers. The transition between active and inactive states occurs through multiple pathways, facilitated by a number of nonnative transient hydrogen bonds, thus lowering the transition barrier through both entropic and enthalpic contributions. These findings may represent general features for functional conformational transitions within the folded state.

[Lipid and fatty acid profiles of Pseudomonas aurantiaca DNA-bound lipids determined by mass spectrometry].

An approach used on investigation of the lipid composition of loosely (fraction 1) and tightly (fraction 2) DNA-bound lipids of Pseudomonas aurantiaca cells by electrospray ionization using mass spectrometry (ESI-LC-MS) was used for determination of the lipidom of a prokaryotic cell. Free fatty acids C16:0, C18:1 (fraction 1), C14:0, C16:0, and C18:2 (fraction 2) were detected. Both fractions of DNA-bound lipids were characterized by the presence of phosphatidylglycerol, phosphatidylserine, and lyso-phosphatidylinositol. The alcohol-soluble fraction 1 could also contain phosphatidylcholine and phosphatidylinositol, while fraction 2 probably contained triacylglycerides. Compared to gas chromatography, ESI-LC-MS provides new possibilities for investigation of the nucleoid lipidome, providing for more detailed investigation of DNA-bound lipids in bacterial cells.

WHO/ISH total risk approach for primary prevention of cardiovascular disease shows greater decrease in costs for women but not the elderly in Jamaica.

OBJECTIVES: To investigate cost savings from and implications of replacing the single risk with a total cardiovascular risk approach in primary prevention of cardiovascular disease (CVD). STUDY DESIGN AND SETTING: A cost analysis using data from the 2007-08 Jamaica Health and Lifestyle Survey of 1,432 persons aged 40 years and older with 10-year risk estimated from region-specific World Health Organization/International Society for Hypertension (WHO/ISH) CVD risk charts. The WHO/ISH and local treatment guidelines were used to cost lifestyle changes, medications, and provider visits. RESULTS: Use of the total cardiovascular risk approach was less costly regardless of age. Women showed greater cost disparity. However, if 10-year CVD risk was estimated without measured cholesterol, both approaches resulted in similar costs in men ≥60 years. The annual per capita cost of lifestyle recommendations, critical in the absence of pharmacotherapy, was estimated at US $869.05 for diet and US $80 for physical activity. This represents about a third of the annual income of a minimum wage earner. At the national level, implementation of the WHO/ISH total risk approach could reduce health care costs by US $5 million annually. CONCLUSION: Cost savings that mainly resulted from reduced care for women may lead to gender disparity in CVD outcomes.

Hedgehog/GLI and PI3K signaling in the initiation and maintenance of chronic lymphocytic leukemia.

The initiation and maintenance of a malignant phenotype requires complex and synergistic interactions of multiple oncogenic signals. The Hedgehog (HH)/GLI pathway has been implicated in a variety of cancer entities and targeted pathway inhibition is of therapeutic relevance. Signal cross-talk with other cancer pathways including PI3K/AKT modulates HH/GLI signal strength and its oncogenicity. In this study, we addressed the role of HH/GLI and its putative interaction with the PI3K/AKT cascade in the initiation and maintenance of chronic lymphocytic leukemia (CLL). Using transgenic mouse models, we show that B-cell-specific constitutive activation of HH/GLI signaling either at the level of the HH effector and drug target Smoothened or at the level of the GLI transcription factors does not suffice to initiate a CLL-like phenotype characterized by the accumulation of CD5(+) B cells in the lymphatic system and peripheral blood. Furthermore, Hh/Gli activation in Pten-deficient B cells with activated Pi3K/Akt signaling failed to enhance the expansion of leukemic CD5(+) B cells, suggesting that genetic or epigenetic alterations leading to aberrant HH/GLI signaling in B cells do not suffice to elicit a CLL-like phenotype in mice. By contrast, we identify a critical role of GLI and PI3K signaling for the survival of human primary CLL cells. We show that combined targeting of GLI and PI3K/AKT/mTOR signaling can have a synergistic therapeutic effect in cells from a subgroup of CLL patients, thereby providing a basis for the evaluation of future combination therapies targeting HH/GLI and PI3K signaling in this common hematopoietic malignancy.