Wolbachia wMel strain-mediated effects on dengue virus vertical transmission from Aedes aegypti to their offspring.

BACKGROUND: Dengue virus serotypes (DENV-1 to -4) can be transmitted vertically in Aedes aegpti mosquitoes. Whether infection with the wMel strain of the endosymbiont Wolbachia can reduce the incidence of vertical transmission of DENV from infected females to their offspring is not well understood. METHODS: A laboratory colony of Vietnamese Ae. aegypti, both with and without wMel infection, were infected with DENV-1 by intrathoracic injection (IT) to estimate the rate of vertical transmission (VT) of the virus. VT in the DENV-infected mosquitoes was calculated via the infection rate estimation from mosquito pool data using maximum likelihood estimation (MLE). RESULTS: In 6047 F1 Vietnamese wild-type Ae. aegypti, the MLE of DENV-1 infection was 1.49 per 1000 mosquitoes (95% confidence interval [CI] 0.73-2.74). In 5500 wMel-infected Ae. aegypti, the MLE infection rate was 0 (95% CI 0-0.69). The VT rates between mosquito lines showed a statistically significant difference. CONCLUSIONS: The results reinforce the view that VT is a rare event in wild-type mosquitoes and that infection with wMel is effective in reducing VT.

Learning meaningful latent space representations for patient risk stratification: Model development and validation for dengue and other acute febrile illness.

Background: Increased data availability has prompted the creation of clinical decision support systems. These systems utilise clinical information to enhance health care provision, both to predict the likelihood of specific clinical outcomes or evaluate the risk of further complications. However, their adoption remains low due to concerns regarding the quality of recommendations, and a lack of clarity on how results are best obtained and presented. Methods: We used autoencoders capable of reducing the dimensionality of complex datasets in order to produce a 2D representation denoted as latent space to support understanding of complex clinical data. In this output, meaningful representations of individual patient profiles are spatially mapped in an unsupervised manner according to their input clinical parameters. This technique was then applied to a large real-world clinical dataset of over 12,000 patients with an illness compatible with dengue infection in Ho Chi Minh City, Vietnam between 1999 and 2021. Dengue is a systemic viral disease which exerts significant health and economic burden worldwide, and up to 5% of hospitalised patients develop life-threatening complications. Results: The latent space produced by the selected autoencoder aligns with established clinical characteristics exhibited by patients with dengue infection, as well as features of disease progression. Similar clinical phenotypes are represented close to each other in the latent space and clustered according to outcomes broadly described by the World Health Organisation dengue guidelines. Balancing distance metrics and density metrics produced results covering most of the latent space, and improved visualisation whilst preserving utility, with similar patients grouped closer together. In this case, this balance is achieved by using the sigmoid activation function and one hidden layer with three neurons, in addition to the latent dimension layer, which produces the output (Pearson, 0.840; Spearman, 0.830; Procrustes, 0.301; GMM 0.321). Conclusion: This study demonstrates that when adequately configured, autoencoders can produce two-dimensional representations of a complex dataset that conserve the distance relationship between points. The output visualisation groups patients with clinically relevant features closely together and inherently supports user interpretability. Work is underway to incorporate these findings into an electronic clinical decision support system to guide individual patient management.

Precise visuomotor transformations underlying collective behavior in larval zebrafish.

Complex schooling behaviors result from local interactions among individuals. Yet, how sensory signals from neighbors are analyzed in the visuomotor stream of animals is poorly understood. Here, we studied aggregation behavior in larval zebrafish and found that over development larvae transition from overdispersed groups to tight shoals. Using a virtual reality assay, we characterized the algorithms fish use to transform visual inputs from neighbors into movement decisions. We found that young larvae turn away from virtual neighbors by integrating and averaging retina-wide visual occupancy within each eye, and by using a winner-take-all strategy for binocular integration. As fish mature, their responses expand to include attraction to virtual neighbors, which is based on similar algorithms of visual integration. Using model simulations, we show that the observed algorithms accurately predict group structure over development. These findings allow us to make testable predictions regarding the neuronal circuits underlying collective behavior in zebrafish.

Randomized Pilot Study: A Mobile Technology-based Self-management Intervention for Sickle Cell Pain.

Little is known about the effects of self-managed relaxation interventions on pain, stress, and autonomic responses in patients with sickle cell disease (SCD). This pre-post randomized controlled pilot study was conducted to determine the feasibility of using computer tablets for relaxation intervention delivery; acceptability of study procedures; and intervention effects on pain, stress, and indicators of relaxation. The 30 research participants ranged in age from 22 years to 59 years. All were African American; 53% were male. They were randomized to an experimental group that watched a relaxation video or a control group that discussed their disease. All participants completed the study, indicating feasibility. Acceptability rates were also high. Data were obtained for the intervention's immediate effect on pain, stress, respiration, pulse, finger skin temperature, and self-reported relaxation. These preliminary findings will guide future, higher-powered studies to determine the intervention's efficacy and mechanism in SCD.The ClinicalTrials.gov Identifier: NCT02729363.

Factors associated with a low prevalence of exclusive breastfeeding during hospital stay in urban and semi-rural areas of southern Vietnam.

BACKGROUND: There is a paucity of data regarding risk factors associated with suboptimal breastfeeding practices in urbanized areas of low-middle income countries (LMICs). METHODS: Through a large prospective birth cohort, which enrolled 6706 infants in Vietnam between 2009 and 2013, we investigated the practice of exclusive breastfeeding during hospital stay in urban and semi-rural populations and aimed to identify factors associated with suboptimal breastfeeding practices. Univariate and multivariable logistic regression were performed to determine factors associated with not exclusive breastfeeding during hospital stay. RESULTS: Of 6076 mothers, 33% (2187) breastfed their infant exclusively before hospital discharge; 9% (364/4248) in urban and 74% (1823/2458) in semi-rural areas. Exclusive breastfeeding up to 4 months was recorded in 15% (959/6210) of participants; this declined to < 1% (56/6093) at 6 months. Delivery by Caesarean section (Odds Ratio [OR] 0.07; 95% Confidence Interval [CI] 0.04, 0.11 and OR 0.05; 95% CI 0.03, 0.08) and neonatal complications (OR 0.2; 95% CI 0.07, 0.47 and OR 0.25; 95% CI 0.14, 0.46) were common and highly significant risk factors associated with a lack of exclusive breastfeeding during hospital stay in urban and semi-rural settings, respectively. CONCLUSIONS: To our knowledge, this is the first large-scale investigation aimed at identifying factors associated with exclusive breastfeeding during hospital stay in Vietnam. Breastfeeding promotion strategies should prioritize common risk factors in hospital, such as Caesarean section and neonatal complications, and other location specific factors associated with socioeconomics.

New primary malignancy masquerading as metastatic prostate adenocarcinoma.

In the management of patients with prostate cancer, the development of new radiographic findings can mimic progression of the disease, thereby triggering changes in treatment. Typically, clinicians evaluate additional parameters, such as symptoms and prostate specific antigen (PSA) levels, for further evidence of disease progression. In the absence of additional findings, for example, elevated PSA, the possibility of an additional malignancy should be considered and evaluated. We present three cases of patients undergoing treatment for prostate adenocarcinoma and discovered on imaging to have findings suggestive of disease progression, but ultimately found to be a new primary malignancy. Our cases suggest that, in patients with prostate cancer, the appearance of new lymphadenopathy or bone lesions cannot be assumed to solely represent progression of the prostate cancer and warrant further investigation, especially in the presence of stable PSA levels.

Crosstalk between oligodendrocytes and cerebral endothelium contributes to vascular remodeling after white matter injury.

After stroke and brain injury, cortical gray matter recovery involves mechanisms of neurovascular matrix remodeling. In white matter, however, the mechanisms of recovery remain unclear. In this study, we demonstrate that oligodendrocytes secrete matrix metalloproteinase-9 (MMP-9), which accelerates the angiogenic response after white matter injury. In primary oligodendrocyte cultures, treatment with the proinflammatory cytokine interleukin-1ß (IL-1ß) induced an upregulation and secretion of MMP-9. Conditioned media from IL-1ß-stimulated oligodendrocytes significantly amplified matrigel tube formation in brain endothelial cells, indicating that MMP-9 from oligodendrocytes can promote angiogenesis in vitro. Next, we asked whether similar signals and substrates operate after white matter injury in vivo. Focal white matter injury and demyelination was induced in mice via stereotactic injection of lysophosphatidylcholine into corpus callosum. Western blot analysis showed that IL-1ß expression was increased in damaged white matter. Immunostaining demonstrated MMP-9 signals in myelin-associated oligodendrocytic basic protein-positive oligodendrocytes. Treatment with an IL-1ß-neutralizing antibody suppressed the MMP-9 response in oligodendrocytes. Finally, we confirmed that the broad spectrum MMP inhibitor GM6001 inhibited angiogenesis around the injury area in this white matter injury model. In gray matter, a neurovascular niche promotes cortical recovery after brain injury. Our study suggests that an analogous oligovascular niche may mediate recovery in white matter.

Quebec breast cancer screening program: a study of the perceptions of physicians in Laval, Que.

OBJECTIVE: To identify physicians' perceptions of breast cancer prevention in order to generate strategies to increase women's participation in the Quebec breast cancer screening program (QBCSP). DESIGN: Qualitative study using archival data and in-depth interviews. SETTING: Laval, Que, a suburban city north of Montreal. PARTICIPANTS: Twenty family physicians and 1 gynecologist practising in Laval who had received at least 1 screening mammography report in 2004 or 2005. METHODS: Archival data were obtained in order to refine our understanding of the QBCSP. In-depth individual interviews were conducted with participating physicians until data saturation was reached in order to determine physicians' knowledge of, beliefs and attitudes about, and behaviour toward preventive breast cancer practices, as well as their suggestions for enhancing patient compliance. The interviews were recorded, transcribed, and coded, and the content was analyzed. MAIN FINDINGS: Respondents indicated that the screening age groups, the age for beginning clinical breast examination, and the instructions to patients about breast self-examination should be harmonized. Letters to patients should be shortened, simplified, and endorsed by physicians. Screening mammography reports should include more details and be clearer about patient follow-up. The need for patients to sign authorization forms for transmission of information related to their participation in the QBCSP should be reinforced by their physicians. Following abnormal mammogram results, services and procedures should be simplified and delays in appointments decreased. Referral for "orphan patients" (ie, patients without family physicians) should be supervised by nurse practitioners, with physician consultations when needed. CONCLUSION: This study provides a qualitative understanding of improvements or modifications needed in order to reach a screening mammography participation rate sufficient to reduce breast cancer mortality in women.

Why and according to what consultation profiles do female sex workers consult health care professionals? A study conducted in Laval, Québec.

We carried out a study to understand help-seeking behavior among female sex workers in order to bring adequate health care and services to this population at risk for sexually transmitted infection (STI) and human immunodeficiency virus (HIV) transmissions. Data were collected by means of questionnaires, focus groups, and in-depth individual interviews. Analysis reveals that the respondents are familiar with and have access to the health care system. Over 80% claimed to have consulted a health professional during the preceding 12 months. Gynecological, psychosocial, respiratory, digestive, and drug addiction problems were the most frequent. Only a third of the respondents received care and services related to STIs. Data are displayed as three consultation profiles, one of which only tends to foster continuity and comprehensive health care, including screening and treatment of STIs.

Sustainability of the impact of a public health intervention: lessons learned from the laval walking clubs experience.

To inform health promotion practice regarding the sustainability of public health interventions, the authors interviewed the directors of 13 new community-based organizations created through a practitioner-initiated public health intervention designed to promote physical activity at the community level. The purpose of the interviews was to uncover the factors that lead organization directors to become involved in the initiative and to maintain their involvement across an extended period of time. Results showed that there were 3 categories of positive outcomes associated with leading a walking club: maintaining and improving health, personal satisfaction, and group motivation. Difficulties associated with directing the club included high participant turnover rates, isolation of club directors, and lack of support from community organizations. Club directors indicated that sustainability would be enhanced through developing individual competencies, becoming more proficient at leading group dynamics, and developing better rootedness in the community. This information is interpreted in light of the six factors associated with sustainability.

Validation of an HPLC method on short columns to assay ketoconazole and formaldehyde in shampoo.

An HPLC method to determine simultaneously ketoconazole and formaldehyde in an anti-dandruff shampoo, originally developed on a long column, was transferred to two short columns with similar stationary phase properties, but with a length of at the most 30% of the initial one. Using the conventional column as reference, the fast HPLC methods on the short columns were validated. The validation characteristics consisted of selectivity, linearity range, precision (repeatability and time-different intermediate precision), bias and robustness. For the ketoconazole assay, linearity for peak area was found in the concentration range up to 0.20 mg/ml. For formaldehyde, two calibration ranges (0-10 x 10(-5) and 0-10 x 10(-4)%) were linear, both for peak area and height. The assays for both ketoconazole and formaldehyde in these ranges showed no bias and an acceptable precision, although the precision found with the short columns was slightly worse than with the long one. The robustness tests were performed applying a Plackett-Burman design. For the ketoconazole assay, 6 factors were examined in a 12 experiments design and for formaldehyde, 11 factors in 16 experiments. The methods were found to be robust. Despite the somewhat less good precision the transfer seems to be successful and the obtained assays on the short columns are applicable for fast routine analysis.

Evaluating the Fabreville Heart Health Program in Laval, Canada: a dialogue between two paradigms, positivism and constructivism.

As part of the Canadian Federal-Provincial Initiative in Heart Health, the goal of the Fabreville Heart Health Program was to sensitize a district of Laval, Quebec's second most populous city, to heart-healthy behaviours. The program was planned and implemented by a committee composed of Fabreville community leaders and professionals from the Public Health Department. Between 1992 and 1994, intervention objectives were defined by the department in terms of changing individual behaviours associated with cardiovascular risk factors, namely diet, sedentariness and smoking, as well as adapting physical and social environments to facilitate these changes. However, from 1994 to its conclusion in 1997, the program was re-oriented to engage the population in mobilizing their own community and taking charge of interventions themselves. Actions then became dependent on the interests and motivation of Fabreville residents to transform their lifestyles and aspects of their physical environment. The initial evaluation process, based on the positivist paradigm, was designed to measure changes in individual behaviours and certain physical environments, such as an increase in designated non-smoking areas. However, following the re-orientation towards community mobilization, it was decided that evaluation should go beyond the professional production of data to include a process of the collective construction of knowledge. Evaluation methodology then became based on the constructivist paradigm. Yet field constraints such as lack of community involvement in both leadership and process evaluation, and the need to ensure evaluation standards and fulfil sponsor obligations, compelled the Public Health Department to return to using a certain number of positivist methods. The ensuing inter-paradigm dialogue helped broaden the scope of evaluation and contributed to gaining a more in-depth understanding of the processes and outcomes of community mobilization.

[Behavior and beliefs in amateur open water activities. Study of beliefs and attitudes with respect to health risks]. / Comportements et croyances des amateurs d'activités nautiques et de plein air. Etude sur les croyances et les attitudes vis-à-vis des risques à la santé.

OBJECTIVE: The objective of this study was to explore beliefs, attitudes and suggestions concerning effective interventions to promote the use of sun protection, the use of personal flotation devices (PFDs) and the avoidance of contact with water unfit for swimming. METHOD: Interviews were conducted with 36 users and 2 river park activity coordinators on a river in the Greater Montreal area. RESULTS: The respondents recognized the existence of a certain number of negative beliefs and barriers associated with the adoption of safe behaviours, in particular the pointlessness and inconvenience of means of protection against the sun and the wearing of PFDs, the negligible effects of polluted water on health and the thrill of defying bans. To help change beliefs, attitudes and behaviours, the respondents suggested legislative, organizational and individual interventions. INTERPRETATION: The data gathered during this study will help to determine intervention strategies and to set up programs promoting behavioural change among the target population.