Associations of obesogenic behaviors in mothers and obese children participating in a randomized trial

Relatively little research has assessed the association between obesogenic behaviors in parents and their children. The objective of the present analysis was to examine cross-sectional associations in television (TV)/video viewing, sugar-sweetened beverage intake, and fast food intake between mothers and their preschool aged children. We studied baseline data among 428 participants in High Five for Kids, a randomized controlled trial of behavior change among overweight and obese children of ages 2-6.9 years. The main exposures were whether mothers viewed TV/videos <1 h/day, drank <1 serving/day of sugar-sweetened beverages, and ate fast food <1 time/week. The main outcomes were whether children met these goals for the same behaviors. Using multivariate logistic regression adjusted for maternal and child characteristics, we estimated odds ratios of children meeting the behavioral goals. The majority of mothers ate fast food <1 time/week (73%) and drank <1 serving/day of sugar-sweetened beverages (73%), while few mothers viewed <1 h/day of TV/videos (31%). Most children met the fast food goal (68%), but not the goals for sugar-sweetened beverages (31%) or TV/video viewing (13%). In adjusted models, the odds ratios for a child meeting the goal were 3.2 (95% confidence interval (CI) 1.7, 6.2) for TV/video viewing, 5.8 (95% CI 2.8, 12.0) for sugar-sweetened beverage intake, and 17.5 (95% CI 9.8, 31.2) for fast food intake if their mothers met the goal for the same behavior. Obesogenic behaviors of mothers and preschool aged children were strongly associated. Our findings lend support to obesity prevention strategies that target parental behavior and the family environment.     

Apparent survival of tropical birds in a wet,premontane forest in Costa Rica

Despite the importance of tropical birds in the development of life history theory, we lack information about demographic rates and drivers of population dynamics for most species. We used a 7‐year (2007–2013) capture‐mark‐recapture dataset from an exceptionally wet premontane forest at mid‐elevation in Costa Rica to estimate apparent survival for seven species of tropical passerines. For four of these species, we provide the first published demographic parameters. Recapture probabilities ranged from 0.21 to 0.53, and annual estimates of apparent survival varied from 0.23 to 1.00. We also assessed the consequences of inter‐annual variation in rainfall on demographic rates. Our results are consistent with inter‐annual rainfall increasing estimates of apparent survival for two species and decreasing estimates for three species. For the three species where we could compare our estimates of apparent survival to estimates from drier regions, our estimates were not consistently higher or lower than those published previously. The temporal and spatial variability in demographic rates we document within and among species highlights the difficulties of generalizing life history characteristics across broad biogeographic gradients. Most importantly, this work emphasizes the context‐specific role of precipitation in shaping tropical avian demographic rates and underscores the need for mechanistic studies of environmental drivers of tropical life histories.     

Use of shopping centres in screening for hypertension

In two Edmonton shopping centres 9591 people were screened for hypertension: 3.3% were found to be normotensive but taking antihypertensive medication and another 8.8% were found to have elevated blood pressure. Systolic hypertension alone accounted for 45.3% of the hypertensive cases and diastolic hypertension, with or without systolic, for 54%. Of the group with elevated blood pressure 34.5% had been previously unaware of their condition, 18.7% had never received medication for it, 18.2% had received medication in the past but had discontinued it, 26.1% were still on medication and 2.5% were not taking antihypertensive medication and were uncertain if they had ever done so in the past. Eighty-eight percent of the hypertensives who were receiving no medication went to their physician; 41% were prescribed antihypertensive medication, and 87% were still on treatment three months later and 74% one year after detection. Eighteen percent of those started on treatment had their medication discontinued by their doctor over the next year and 8% stopped treatment on their own. Of those hypertensives already receiving medication 88% went to their doctor and 33% had their medication altered.Physician measurements of blood pressure tended to be lower than those recorded at the screening. At least part of the explanation for this discrepancy is that physicians often used blood pressure cuffs that were too wide for the patient''s arm; 25% of the people screened required cuffs narrower than the standard cuff used by most physicians.The prevalence of hypertension was similar among women taking oral contraceptives and women not taking these agents.     

Diagnostic performance of chest radiography measurements for the assessment of cardiac chamber enlargement

Background:The cardiothoracic ratio (CTR) is commonly assessed on chest radiography for detection of cardiac chamber enlargement, but the traditional cutpoint of 0.5 has low specificity. We sought to evaluate the diagnostic accuracy of new measurement techniques for the detection of cardiac enlargement on chest radiographs.Methods:We obtained retrospective cross-sectional data on consecutive patients who underwent both chest radiography and cardiac magnetic resonance imaging (MRI) within a 14-day interval between 2006 and 2016 at a large academic hospital network. We established the presence of cardiac chamber enlargement using cardiac MRI as the reference standard. We evaluated the diagnostic performance of different techniques for measuring heart size and CTR on frontal chest radiographs.Results:Of 152 patients included, 81 (53%) were men and the mean age was 52 years. Maximum heart diameter had the highest area under the receiver operating characteristic curve for detection of cardiac enlargement (0.827, 95% confidence interval 0.760–0.894). In the subgroup of posteroanterior chest radiography studies (n = 101), a CTR cutpoint of 0.50 had only moderate sensitivity (72%) and specificity (72%). In men, a maximum heart diameter cutpoint of 15 cm had a sensitivity of 86% and a negative likelihood ratio of 0.24, and a cutpoint of 19 cm had a specificity of 100% and a positive likelihood ratio of infinity. In women, a maximum heart diameter cutpoint of 13 cm had a sensitivity of 91% and a negative likelihood ratio of 0.15, and a cutpoint of 17 cm had a specificity of 91% and a positive likelihood ratio of 3.5.Interpretation:A traditional CTR cutpoint of 0.5 has limited diagnostic value. Simple heart diameter measurements have higher diagnostic performance measures than CTR.

Cardiac chamber enlargement is important to identify, given that it is a predictor of poor outcomes and may reflect potentially treatable underlying disease.¹ Cardiac chamber size can be assessed using multiple imaging modalities, including chest radiography, echocardiography, computed tomography and cardiac magnetic resonance imaging (MRI).^2–4 Although cardiac MRI is considered the reference standard for the evaluation of cardiac size and function, it is rarely performed as an initial investigation because of its relatively high cost and limited availability.⁵ On the other hand, chest radiography is frequently performed as the initial imaging investigation for suspected pulmonary and cardiac disease, including in patients presenting with shortness of breath and chest pain.^6,7 Therefore, accurate and reproducible measures of cardiac enlargement on chest radiography would help to identify patients with underlying cardiac disease who might benefit from further investigation.Cardiac enlargement is frequently evaluated on chest radiography using the cardiothoracic ratio (CTR), which was originally described in 1919.⁸ Although this sign is an accepted and frequently used marker of cardiac enlargement, it has not been validated against cardiac MRI or other contemporary methods of objectively assessing cardiac chamber size. Some studies have shown that the CTR, as assessed using the originally described cutpoint of 0.5, has low specificity and diagnostic accuracy for cardiac enlargement, and therefore may be of limited clinical utility.^9–11 The purpose of this study was to evaluate new measurement techniques and cutpoints for the detection of cardiac chamber enlargement on chest radiography in comparison with MRI.     

Theoretical analysis of excipient concentrations during the final ultrafiltration/diafiltration step of therapeutic antibody

Diafiltration of a protein solution into a new buffer is a common final step in biopharmaceutical manufacturing. However, the excipient concentrations in the retentate are not always equal to their corresponding concentrations in the new buffer (diafiltration buffer). This phenomenon was observed repeatedly during diafiltration of different therapeutic monoclonal antibodies in which the concentrations of histidine and either sorbitol or sucrose (depending on which was chosen for the diafiltration buffer) in the retentate were lower than in the diafiltration buffer. Experimental studies and theoretical analyses of the ultrafiltration/diafiltration (UF/DF) step were carried out to determine the primary causes of the phenomenon and to develop a mathematical model capable of predicting retentate excipient concentrations. The analyses showed that retentate histidine concentration was low primarily because of repulsive charge interactions between positively‐charged histidine molecules and positively‐charged protein molecules, and that volume exclusion effects were secondary for like‐charged molecules. The positively‐charged protein molecules generate an electrical potential that cause an uneven distribution of charged histidine molecules. This interaction was used to construct a mathematical model based on the Poisson‐Boltzmann equation. The model successfully predicted the final histidine concentration in the diafiltered product (retentate) from the UF/DF development and production runs, with good agreement across a wide range of protein and histidine concentrations for four therapeutic monoclonal antibodies. The concentrations of uncharged excipients (sorbitol or sucrose) were also successfully predicted using previously established models, with volume exclusion identified as the primary cause of differences in uncharged excipient concentrations in the retentate and diafiltration buffer. © 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2009     

Plasmodium falciparum gametocyte carriage, emergence, clearance and population sex ratios in anaemic and non-anaemic malarious children

Anaemia in falciparum malaria is associated with an increased risk of gametocyte carriage, but its effects on transmission have not been extensively evaluated in malarious children. Plasmodium falciparum gametocyte carriage, emergence, clearance, population sex ratios (SR) (defined as the proportion of gametocytes that are male), inbreeding rates and temporal changes in SR were evaluated in 840 malarious children. Gametocyte carriage pre-treatment was at a level of 8.1%. Anaemia at enrolment was an independent risk factor for gametocyte carriage post-treatment. The emergence of gametocytes seven days post-treatment was significantly more frequent in anaemic children (7/106 vs. 10/696, p = 0.002). In the initially detected gametocytes, the proportion of children with a male-biased SR (MBSR) (> 0.5) was significantly higher in anaemic children (6/7 vs. 3/10, p = 0.027). Pre-treatment SR and estimated inbreeding rates (proportion of a mother's daughters fertilised by her sons) were similar in anaemic and non-anaemic children. Pre-treatment SR became more female-biased in non-anaemic children following treatment. However, in anaemic children, SR became male-biased. Anaemia was shown to significantly increase gametocyte emergence and may significantly alter the SR of emerging gametocytes. If MBSR is more infective to mosquitoes at low gametocytaemia, then these findings may have significant implications for malaria control efforts in endemic settings where malaria-associated anaemia is common.     

Informing Comprehensive HIV Prevention: A Situational Analysis of the HIV Prevention and Care Context,North West Province South Africa

Objective

Building a successful combination prevention program requires understanding the community’s local epidemiological profile, the social community norms that shape vulnerability to HIV and access to care, and the available community resources. We carried out a situational analysis in order to shape a comprehensive HIV prevention program that address local barriers to care at multiple contextual levels in the North West Province of South Africa.

Method

The situational analysis was conducted in two sub-districts in 2012 and guided by an adaptation of WHO’s Strategic Approach, a predominantly qualitative method, including observation of service delivery points and in-depth interviews and focus groups with local leaders, providers, and community members, in order to recommend context-specific HIV prevention strategies. Analysis began during fieldwork with nightly discussions of findings and continued with coding original textual data from the fieldwork notebooks and a select number of recorded interviews.

Results

We conducted over 200 individual and group interviews and gleaned four principal social barriers to HIV prevention and care, including: HIV fatalism, traditional gender norms, HIV-related stigma, and challenges with communication around HIV, all of which fuel the HIV epidemic. At the different levels of response needed to stem the epidemic, we found evidence of national policies and programs that are mitigating the social risk factors but little community-based responses that address social risk factors to HIV.

Conclusions

Understanding social and structural barriers to care helped shape our comprehensive HIV prevention program, which address the four ‘themes’ identified into each component of the program. Activities are underway to engage communities, offer community-based testing in high transmission areas, community stigma reduction, and a positive health, dignity and prevention program for stigma reduction and improve communication skills. The situational analysis process successfully shaped key programmatic decisions and cultivated a deeper collaboration with local stakeholders to support program implementation.