Evaluating the impact of the Community Helpers Program on adolescents 12-18 years old in Edmonton, Canada

INTERVENTION

Alberta Health Services (AHS) Community Helpers Program (CHP) to enhance mental health among youth.

RESEARCH QUESTION

Identifying the impact of CHP on mental illness-related acute care use among adolescents aged 12-18 years in Edmonton and determining cost avoidance.

METHODS

Using administrative data from AHS, public school catchment area data from the Edmonton Public School Board, and area-level socioeconomic deprivation status indicators from the Pampalon deprivation index, we applied geographical regression discontinuity design to estimate the effect of CHP implementation on depression-, anxiety-, and suicide-related acute care use (emergency department visits and inpatient admissions). Cost data were derived from Interactive Health Data Application of Alberta Health. The study period (2002-2022) included pre (2002-2011) and post (2012-2020) CHP implementation periods.

RESULTS

CHP had statistically significant impact when distance from the boundary (catchment area identifier to divide the sample into treated and control groups) was between 600 and 800 m. About 90 and 80 fewer anxiety- and depression-related visits (per 1000 visits) were observed among individuals aged 12-15 and 16-18 years, respectively, in catchment areas of the public schools where CHP was implemented. Impact of CHP on suicide-related visits was only statistically significant among individuals aged 12-15 years. Annual cost reduction ranged from $161,117 to $269,255 for anxiety- and depression-related visits.

CONCLUSION

Findings show contextual effect of CHP; i.e., being potentially exposed to the program reduced the likelihood of anxiety- and depression-related visits. Costs of CHP implementation could be compared with the avoided costs to assess economic benefits of implementing CHP.

Investigating associations between maternal stress, smoking and adverse birth outcomes: evidence from the All Our Families cohort

BACKGROUND

Independently, active maternal and environmental tobacco smoke exposure and maternal stress have been linked to an increased risk of preterm birth and low birth weight. An understudied relationship is the potential for interactive effects between these risk factors.

METHODS

Data was obtained from the All Our Families cohort, a study of 3,388 pregnant women < 25 weeks gestation recruited from those receiving prenatal care in Calgary, Canada between May 2008 and December 2010. We investigated the joint effects of active maternal smoking, total smoke exposure (active maternal smoking plus environmental tobacco smoke) and prenatal stress (Perceived Stress Scale, Spielberger State-Trait Anxiety Inventory), measured at two time points (< 25 weeks and 34-36 weeks gestation), on preterm birth and low birth weight.

RESULTS

A marginally significant association was observed with the interaction active maternal smoking and Spielberger State-Trait Anxiety Inventory scores in relation to low birth weight, after imputation (aOR = 1.02, 95%CI: 1.00-1.03, p = 0.06). No significant joint effects of maternal stress and either active maternal smoking or total smoke exposure with preterm birth were observed. Active maternal smoking, total smoke exposure, Perceived Stress Scores, and Spielberger State-Trait Anxiety Inventory scores were independently associated with preterm birth and/or low birth weight.

CONCLUSIONS

Findings indicate the role of independent effects of smoking and stress in terms of preterm birth and low birthweight. However, the etiology of preterm birth and low birth weight is complex and multifactorial. Further investigations of potential interactive effects may be useful in helping to identify women experiencing vulnerability and inform the development of targeted interventions.

Long-term health care use and diagnosis after hospitalization for COVID-19: a retrospective matched cohort study

BACKGROUND

Knowledge pertaining to the health and health care utilization of patients after recovery from acute COVID-19 is limited. We sought to assess the frequency of new diagnoses of disease and health care use after hospitalization with COVID-19.

METHODS

We included all patients hospitalized with COVID-19 in Alberta between Mar. 5 and Dec. 31, 2020. Additionally, 2 matched controls (SARS-CoV-2 negative) per case were included and followed up until Apr. 30, 2021. New diagnoses and health care use were identified from linked administrative health data. Repeated measures were made for the periods 1-30 days, 31-60 days, 61-90 days, 91-180 days, and 180 and more days from the index date. We used multivariable regression analysis to evaluate the association of COVID-19-related hospitalization with the number of physician visits during follow-up.

RESULTS

The study sample included 3397 cases and 6658 controls. Within the first 30 days of follow-up, the case group had 37.12% (95% confidence interval [CI] 35.44% to 38.80%) more patients with physician visits, 11.12% (95% CI 9.77% to 12.46%) more patients with emergency department visits and 2.92% (95% CI 2.08% to 3.76%) more patients with hospital admissions than the control group. New diagnoses involving multiple organ systems were more common in the case group. Regression results indicated that recovering from COVID-19-related hospitalization, admission to an intensive care unit, older age, greater number of comorbidities and more prior health care use were associated with increased physician visits.

INTERPRETATION

Patients recovered from the acute phase of COVID-19 continued to have greater health care use up to 6 months after hospital discharge. Research is required to further explore the effect of post-COVID-19 conditions, pre-existing health conditions and health-seeking behaviours on health care use.

Color coded health data: factors related to willingness to share health information in South Asian community members in Canada

Introduction

Data unavailability poses multiple challenges in many health fields, especially within ethnic subgroups in Canada, who may be hesitant to share their health data with researchers. Since health information availability is controlled by the participant, it is important to understand the willingness to share health information by an ethnic population to increase data availability within ethnocultural communities.

Methods

We employed a qualitative descriptive approach to better understand willingness to share health information by South Asian participants and operated through a lens that considered the cultural and sociodemographic aspect of ethnocultural communities. A total of 22 in-depth interviews were conducted between March and July 2020.

Results

The results of this study show that health researchers should aim to develop a mutually beneficial information-sharing partnership with communities, with an emphasis on the ethnocultural and socio-ecological aspects of health within populations.

Conclusion

The findings support the need for culturally sensitive and respectful engagement with the community, ethically sound research practices that make participants feel comfortable in sharing their information, and an easy sharing process to share health information feasibly.

Predictive profiling of gram-negative antibiotics in CagA oncoprotein inactivation: a molecular dynamics simulation approach

Gastric cancer (GC) is the fifth most prevalent form of cancer worldwide. CagA - positive Helicobacter pylori infects more than 60% of the human population. Moreover, chronic infection of CagA-positive H. pylori can directly affect GC incidence. In the current study, we have repurposed FDA-approved antibiotics that are viable alternatives to current regimens and can potentially be used as combination therapy against the CagA of H. pylori. The 100 FDA-approved gram negative antibiotics were screened against CagA protein using the AutoDock 4.2 tool. Further, top nine compounds were selected based on higher binding affinity with CagA. The trajectory analysis of MD simulations reflected that binding of these drugs with CagA stabilizes the system. Nonetheless, atomic density map and principal component analysis also support the notion of stable binding of antibiotics to the protein. The residues ASP96, GLN100, PRO184, and THR185 of compound cefpiramide, doxycycline, delafloxacin, metacycline, oxytetracycline, and ertapenem were involved in the binding with CagA protein. These residues are crucial for the CagA that aids in entry or pathogenesis of the bacterium. The screened FDA-approved antibiotics have a potential druggability to inhibit CagA and reduce the progression of H. pylori borne diseases.

Reasons and suggestions for improving low immunization uptake among children living in low socioeconomic status communities in Northern Alberta, Canada - A qualitative study

OBJECTIVE

Under-immunization increases the risk of acquiring vaccine-preventable diseases in children and the community. The targeted coverage rate for routine childhood immunization in Alberta, especially in disadvantaged communities in rural and remote geographic areas, has not been achieved for many years. This study was conducted to identify reasons for under-immunization in children in low socioeconomic status (SES) communities and propose suggestions to address issues/concerns identified by low SES parents for improving immunization coverage in their communities.

METHODS

Fourteen semi-structured phone interviews of low SES parents with under-immunized children living in rural and remote geographic areas in Northern Alberta were conducted. Transcripts were analyzed to identify relevant themes.

RESULTS

Busy lifestyles of many parents prevented them from taking their children to clinics for immunization, which were exacerbated by long distances to clinics, transportation issues, operating hours of clinics, and lack of reminders. Many disadvantaged parents also exhibited varying levels of vaccine hesitancy due to safety concerns, especially about newer vaccines, thereby causing some parents to delay immunizing their child intentionally.

CONCLUSION

Implementing procedures to alleviate access issues, such as offering extended operating hours, opening drop-in clinics/satellite clinics in distant areas, nurse visits to their homes, updating contact information of parents, frequent reminder options and addressing safety and effectiveness concerns about vaccines in plain language using evidence-based communication strategies can promote timely immunization among children of low SES parents.

Automating data collection methods in electronic health record systems: a Social Determinant of Health (SDOH) viewpoint

Social Determinant of Health (SDOH) data are important targets for research and innovation in Health Information Systems (HIS). The ways we envision SDOH in "smart" information systems will play a considerable role in shaping future population health landscapes. Current methods for data collection can capture wide ranges of SDOH factors, in standardised and non-standardised formats, from both primary and secondary sources. Advances in automating data linkage and text classification show particular promise for enhancing SDOH in HIS. One challenge is that social communication processes embedded in data collection are directly related to the inequalities that HIS attempt to measure and redress. To advance equity, it is imperative thatcare-providers, researchers, technicians, and administrators attend to power dynamics in HIS standards and practices. We recommend: 1. Investing in interdisciplinary and intersectoral knowledge generation and translation. 2. Developing novel methods for data discovery, linkage and analysis through participatory research. 3. Channelling information into upstream evidence-informed policy.

Predicting the Risk Factors Associated With Severe Outcomes Among COVID-19 Patients–Decision Tree Modeling Approach

Background

The COVID-19 pandemic has seen a large surge in case numbers over several waves, and has critically strained the health care system, with a significant number of cases requiring hospitalization and ICU admission. This study used a decision tree modeling approach to identify the most important predictors of severe outcomes among COVID-19 patients.

Methods

We identified a retrospective population-based cohort (n = 140,182) of adults who tested positive for COVID-19 between 5^th March 2020 and 31^st May 2021. Demographic information, symptoms and co-morbidities were extracted from a communicable disease and outbreak management information system and electronic medical records. Decision tree modeling involving conditional inference tree and random forest models were used to analyze and identify the key factors(s) associated with severe outcomes (hospitalization, ICU admission and death) following COVID-19 infection.

Results

In the study cohort, nearly 6.37% were hospitalized, 1.39% were admitted to ICU and 1.57% died due to COVID-19. Older age (>71Y) and breathing difficulties were the top two factors associated with a poor prognosis, predicting about 50% of severe outcomes in both models. Neurological conditions, diabetes, cardiovascular disease, hypertension, and renal disease were the top five pre-existing conditions that altogether predicted 29% of outcomes. 79% of the cases with poor prognosis were predicted based on the combination of variables. Age stratified models revealed that among younger adults (18–40 Y), obesity was among the top risk factors associated with adverse outcomes.

Conclusion

Decision tree modeling has identified key factors associated with a significant proportion of severe outcomes in COVID-19. Knowledge about these variables will aid in identifying high-risk groups and allocating health care resources.

Factors Associated With Willingness to Share Health Information: Rapid Review

Background

To expand research and strategies to prevent disease, comprehensive and real-time data are essential. Health data are increasingly available from platforms such as pharmaceuticals, genomics, health care imaging, medical procedures, wearable devices, and internet activity. Further, health data are integrated with an individual’s sociodemographic information, medical conditions, genetics, treatments, and health care. Ultimately, health information generation and flow are controlled by the patient or participant; however, there is a lack of understanding about the factors that influence willingness to share health information. A synthesis of the current literature on the multifactorial nature of health information sharing preferences is required to understand health information exchange.

Objective

The objectives of this review are to identify peer-reviewed literature that reported factors associated with health information sharing and to organize factors into cohesive themes and present a narrative synthesis of factors related to willingness to share health information.

Methods

This review uses a rapid review methodology to gather literature regarding willingness to share health information within the context of eHealth, which includes electronic health records, personal health records, mobile health information, general health information, or information on social determinants of health. MEDLINE and Google Scholar were searched using keywords such as electronic health records AND data sharing OR sharing preference OR willingness to share. The search was limited to any population that excluded health care workers or practitioners, and the participants aged ≥18 years within the US or Canadian context. The data abstraction process using thematic analysis where any factors associated with sharing health information were highlighted and coded inductively within each article. On the basis of shared meaning, the coded factors were collated into major themes.

Results

A total of 26 research articles met our inclusion criteria and were included in the qualitative analysis. The inductive thematic coding process revealed multiple major themes related to sharing health information.

Conclusions

This review emphasized the importance of data generators’ viewpoints and the complex systems of factors that shape their decision to share health information. The themes explored in this study emphasize the importance of trust at multiple levels to develop effective information exchange partnerships. In the case of improving precision health care, addressing the factors presented here that influence willingness to share information can improve sharing capacity for individuals and allow researchers to reorient their methods to address hesitation in sharing health information.

Radial Long Sheath Angioplasty for Proximal Severe Flow Limiting Radial Artery Spasm Utilizing the Dotter Technique

BACKGROUND

Although studies continue to demonstrate the advantages of transradial access (TRA) for neurointerventions, radial artery spasm (RAS) remains a frequent cause of TRA failure. Dotter initially described a technique to dilate areas of peripheral vascular stenosis by advancing sequentially larger catheters across the lesion over a wire. We present our institutional experience performing a modified Dotter technique utilizing long radial sheaths to dilate areas of proximal flow limiting RAS.

OBJECTIVE

To review the use of the Dotter technique for alleviating RAS in patients undergoing TRA for neurointerventions.

METHODS

A retrospective review of all patients undergoing TRA for neurointerventions at our institution from 2018-2020 was performed to identify patients with proximal flow limiting RAS. In identified patients, a modified Dotter technique was employed to dilate the stenosis. Demographic and periprocedural data were assessed to identify any adverse outcomes.

RESULTS

Four patients with severe proximal flow limiting RAS were identified. In each case, a hydrophilic long radial sheath and vascular dilator were sequentially advanced through the stenosis. In all cases, repeat angiography demonstrated improvement of the spasm and final radial angiograms demonstrated persistent improvement in caliber and regularity of the vessel. Each procedure was also completed via TRA with no periprocedural complications.

CONCLUSIONS

Our modified Dotter technique is effective in bypassing areas of severe proximal flow limiting RAS thus obviating the need for access site conversion. Additional studies are warranted to understand the implication of the angioplasty-like effects seen within the radial artery following removal of the long radial sheaths.

Respiratory and cardiovascular condition-related physician visits associated with wildfire smoke exposure in Calgary, Canada, in 2015: a population-based study

BACKGROUND

We studied the impact of fine particulate matter (PM2.5) exposure due to a remote wildfire event in the Pacific Northwest on daily outpatient respiratory and cardiovascular physician visits during wildfire (24-31 August, 2015) and post-wildfire period (1-30 September, 2015) relative to the pre-wildfire period (1-23 August, 2015) in the city of Calgary, Canada.

METHODS

A quasi-Poisson regression model was used for modelling daily counts of physician visits due to PM2.5 while adjusting for day of the week (weekday versus weekend or public holiday), wildfire exposure period (before, during, after), methane, relative humidity, and wind direction. A subgroup analysis of those with pre-existing diabetes or hypertension was performed.

RESULTS

An elevated risk of respiratory disease morbidity of 33% (relative risk: RR) [95% confidence interval (CI): 10%-59%] and 55% (95% CI: 42%-69%) was observed per 10µg/m3 increase in PM2.5 level during and after wildfire, respectively, relative to the pre-wildfire time period. Increased risk was observed for children aged 0-9 years during (RR = 1.57, 95% CI: 1.21-2.02) and after the wildfire (RR = 2.11, 95% CI: 1.86-2.40) especially for asthma, acute bronchitis and acute respiratory infection. The risk of physician visits among seniors increased by 11% (95% CI: 3%-21%), and 19% (95% CI: 7%-33%) post-wildfire for congestive heart failure and ischaemic heart disease, respectively. Individuals with pre-existing diabetes had an increased risk of both respiratory and cardiovascular morbidity in the post-wildfire period (RR = 1.35, 95% CI: 1.09-1.67; RR = 1.22, 95% CI: 1.01-1.46, respectively).

CONCLUSIONS

Wildfire-related PM2.5 exposure led to increased respiratory condition-related outpatient physician visits during and after wildfires, particularly for children. An increased risk of physician visits for congestive heart failure and ischaemic heart disease among seniors in the post-wildfire period was also observed.

Effective interventions to increase routine childhood immunization coverage in low socioeconomic status communities in developed countries: A systematic review and critical appraisal of peer-reviewed literature

OBJECTIVES

Childhood immunization coverage rates are known to be disproportionate according to population's socioeconomic status (SES). This systematic review examined and appraised quality of interventions deemed effective to increase routine childhood immunization uptake in low SES populations in developed countries.

METHODS

A literature search was conducted using Medline, Embase, CINAHL, EBMR, PsycInfo, PubMed, and Health STAR. We systematically searched and critically appraised articles published between January 1990 and December 2019 using the Effective Public Health Practice Project Quality Assessment tool. This systematic review provides a synthesis of the available evidence for childhood immunization interventions deemed effective for low SES parents or families of children ≤ 5 years of age.

SYNTHESIS

The search yielded 3317 records, of which 2975 studies met the inclusion criteria. From the 100 relevant studies, a total of 40 were included. The majority of effective and strongly rated studies synthesized consisted of multi-component interventions. Such interventions addressed access, community-based mobilization, outreach, appointment reminders, education, clinical tracking and incentives, and were language and health literacy appropriate to support low SES parents. Improving access to low SES parents was deemed effective in the vast majority of strongly rated studies. Incorrect contact information of low SES parents due to increased social mobility (i.e. household moves) rendered reminders ineffective, and therefore, updating contact information should be pursued proactively by front-line healthcare providers. In addition, plain language communication with low SES parents regarding immunization was deemed effective in improving immunization uptake.

CONCLUSION

Comprehensive multi-component interventions including improved access, appointment reminders, education and precision health communication are effective for addressing health inequities in immunization coverage amongst marginalized populations. Most low SES parents still believe that the benefits of immunization outweigh the risks.

Polymeric Micelles of Modified Chitosan Block Copolymer as Nanocarrier for Delivery of Paclitaxel

Background:

Polymeric micelles are being used as successful nanocarriers for the delivery of diverse drug molecules due to properties like solubilization, selective targeting, P-glycoprotein inhibition, altered drug internalization route and subcellular localization etc.

Objective:

The present investigation was planned to prepare and characterize novel polymeric micelles derived from self assembly of amphiphilic chitosan-bile salt derivative (CS-mPEG-DA) as nanocarrier and evaluate their potential in delivery of an anticancer drug, paclitaxel.

Method:

Paclitaxel, a diterpenoid compound, useful in clinical treatment of several solid tumors such as ovarian cancer, breast cancer and lung cancer suffers from limitations like low aqueous solubility and bioavailability and subsequently was used as the model drug.

Results:

Paclitaxel was successfully incorporated into polymeric micelles using dialysis and emulsion method with encapsulation efficiency up to 95% having particle size in nanometer range (<200 nm). Paclitaxel loaded micelles were found to release the drug in a sustained manner up to 96 h in PBS containing 0.1% (w/v) tween 80 at 37&#176;C. The micelles powders subjected to stability studies for a period of 90 days were found to be stable at 4 &#177; 2&#176;C with respect to particle size and drug content. In vivo cytotoxicity assay confirmed that paclitaxel encapsulated in polymeric micelles showed higher cytotoxicity against cultured MCF-7 breast cancer cells than paclitaxel alone.

Conclusion:

Polymeric micellar systems derived from copolymerization of chitosan exhibit a great potential in successful delivery of poorly water soluble or low bioavailable drugs like paclitaxel.

Maternal perceptions of childhood vaccination: explanations of reasons for and against vaccination

BACKGROUND

Understanding reasons for and against vaccination from the parental perspective is critical for designing vaccination campaigns and informing other interventions to increase vaccination uptake in Canada. The objective of this study was to understand maternal vaccination decision making for children.

METHODS

Mothers participating in a longitudinal community-based pregnancy cohort, the All Our Babies study in Calgary, Alberta, completed open-ended survey questions providing explanations for the vaccination status of their child by 24 months postpartum. Qualitative responses were linked to administrative vaccination records to examine survey responses and recorded child vaccination status.

RESULTS

There were 1560 open-ended responses available; 89% (n = 1391) provided explanations for vaccinating their children, 5% (n = 79) provided explanations for not vaccinating/delaying, and 6% (n = 90) provided explanations for both. Themes were similar for those vaccinating and not vaccinating/delaying; however, interpretations were different. Two broad themes were identified: Sources of influence and Deliberative Processes. Sources of influence on decision making included personal, family, and external experiences. Deliberative Processes included risk, research, effectiveness, and balancing risks/benefits. Under Deliberative Processes, responsibility was a category for those vaccinating; while choice, instrumental/practical, and health issues were categories for those not vaccinating/delaying. Mothers' levels of conviction and motivation provided a Context for understanding their decision making perspectives.

CONCLUSIONS

Vaccination decision making is complex and impacted by many factors that are similar but contribute to different decisions depending on mothers' perspectives. The results of this study indicate the need to examine new intervention approaches to increase uptake that recognize and address feelings of pressure and parental commitment to choice.

Using Artificial Intelligence Technology for Social Determinants and Risk Factors Surveillance

Session topic areaData science methods: machine learning in risk factor surveillance Overall objectives or goalBackgroundDecades of research have shown that factors such as living conditions, and not just medical treatments and lifestyles, are strongly associated with the health of individuals and populations. These distal factors (social, economic, cultural and environmental) are collectively called the social determinants of health (SDOH), and affect health inequities (i.e. differences in health outcomes that are avoidable, unfair and unjust). Gathering data on both risk factors (biomedical/clinical) and SDOH is of the utmost importance to quantify their contribution in disease causation at individual and population levels. Social determinants of health and biomedical/clinical risk factors surveillance (collectively termed as “risk factor surveillance”) refers to the monitoring of distal and proximal factors that impact the health of individuals and populations and health equity. It offers the opportunity to “forecast” population health, potential disease incidence, and guide intervention programs to prevent disease manifestation. However, current risk factor surveillance data is limited in geographical representation, completion, and content and time. Identifying novel methods of collecting risk factors and SDOH data can allow for opportunities for population health and disease forecasting using high quality, nationally-representative, real-time data. Recent breakthroughs in artificial intelligence (AI), such as speech and image recognition, offers new opportunities to develop novel methods to collect risk factor information at individual levels. Meanwhile, we can use intelligent computer systems to process vast amount of data and turn those data into actionable information and knowledge for improving population health. Collaborative Session ObjectiveThrough a CIHR-funded project, we are assembling a team of national and international experts including stakeholders, public health officers/physicians, and researchers, who will identify key gaps in risk factor surveillance and data collection technologies. Resulting projects will focus on using AI for risk factor surveillance, for the ultimate purpose of monitoring population health, guiding intervention programs, and preventing disease. Our projects will focus on discovering and refining innovative methods in data collection, management, as well as assessment of data quality (i.e. selection bias). We will engage scientists and knowledge users from the inception of the ideas to ensure the relevancy of the final projects. This project aims to link medical records, clinical information, and SDOH data, to alter the way we conduct surveillance and work with big data. Facilitators involved; home institutions Dr. Vineet Saini, University of Calgary; Alberta Health Services Dr. Mingkai Peng, University of Calgary Dr. Hude Quan, University of Calgary; World Health Organization Collaborating Centre for Classification, Measurement and Standardization Intended output or outcome Identify AI technologies for use in risk factor surveillance; innovative methods in data collection, management, as well as assessment of data quality (i.e. selection bias); uses for new data sources in improving health equity. Create partnerships between national and international experts in risk factor surveillance

Linking air pollution and administrative health databases to examine health effects of wildfire smoke exposure in Calgary, Canada in 2015

IntroductionWildfires are increasing in frequency and severity due to climate change. Fine particulate matter (PM2.5) in wildfire smoke is an important indicator of health effects of most combustion sources. The evidence based on adverse health impacts of PM2.5 from wildfire smoke are increasingly being studied but some gaps still remain. Objectives and ApproachWe examined the association of PM2.5 from Pacific Northwest wildfires with multiple respiratory and cardiovascular morbidity events related physician and emergency department visits, hospital admissions, health-link calls and medications dispensed among Calgary city population from August 1 – September 30, 2015. Physician billing claims, discharge abstract, Pharmaceutical Information Network, Health-link calls databases were linked with the air quality monitoring information database. Quasi-Poisson regression model for time lags of zero to five days and a three-day moving average, and conditional logistic regression model was used with adjustment for air pollutants and meteorological variables. Age and disease-specific stratified analyses were performed. ResultsCompared to the pre-wildfire period (Aug 1 – Aug 23), a 10 µg/m3 increase in PM2.5 increased the risk for respiratory physician visits by 54.8% (95% CI: 41.6% - 69.3%) and 32.6% (95% CI: 10.4% - 58.9%) in the respective post (Sep 1- Sep 30) and during (Aug 24 – Aug 31) wildfire periods. The strongest association of PM2.5 with respiratory physician visits was observed for children aged 0-9 years in the post-wildfire period (Relative Risk [RR] = 2.11, 95% CI: 1.86 - 2.39) compared to during wildfire period (RR = 1.56, 95% CI: 1.21 - 2.02) and was consistent for asthma, acute bronchitis and acute respiratory infection. Statistically significant effects of PM2.5 on cardiovascular hospitalizations, ED and physician visits were not observed during the wildfire period. Conclusion/ImplicationsWildfire-related PM2.5 led to increased physician visits due to respiratory morbidity during and after the wildfires, particularly for asthma, acute bronchitis and acute respiratory infections in children. The absence of cardiovascular health impact in general population during wildfires provides useful information for targeted public health messaging during adverse air quality events.

The impact of time since vaccination and study design on validity in parental recall of childhood vaccination status in the All Our Families cohort

INTRODUCTION

Parental reporting of childhood vaccination status is often used for policy and program evaluation and research purposes. Many factors can bias parental reporting of childhood vaccination status, however, to our knowledge, no analysis has assessed whether time since vaccination impacts reporting accuracy. Therefore, using the Calgary electronic vaccine registry (PHANTIM) as the gold standard, we aimed to test the accuracy of parental reporting of childhood vaccination status at three different time-points since vaccination.

METHODS

The All Our Families (AOF) cohort study asked parents to report their child's 2, 4, 6, 12 and 18 month vaccines (vaccination time-point) on questionnaires given when the child was 1, 2 and 3 years of age (survey time-point). We linked the AOF parental reporting of vaccination status to the PHANTIM registry and calculated the percent agreement and difference in coverage estimates between PHANTIM and AOF at each vaccination and survey time-point combination. Furthermore, we measured the sensitivity and specificity, and negative (NPV) and positive predictive values (PPV) of parental vaccine recall across time.

RESULTS

AOF parent reports of coverage rates were consistently higher than the PHANTIM estimates. While we saw significant differences in percent agreement for certain vaccination time-points, we saw no consistent directional difference by survey time-point, suggesting that parental accuracy did not change with time. We found a uniformly high sensitivity across all vaccination and survey time-points, and no consistent patterns in the specificity, PPV and NPV results.

CONCLUSION

Time since vaccination may not be the most important consideration when designing and implementing a vaccination survey. Other factors that may contribute to the bias associated with parental reporting of vaccination status include the complexity of the vaccine schedule, schedule changes over time, and the wording and structure of the questionnaires.

Invited review: Incidence, risk factors, and effects of clinical mastitis recurrence in dairy cows

Clinical mastitis (CM) is one of the most frequent and costly diseases in dairy cows. A frustrating aspect of CM is its recurrent nature. This review was conducted to synthesize knowledge on risk of repeated cases of CM, effects of recurrent CM cases, and risk factors for CM recurrence. A systematic review methodology was used to identify articles for this narrative review. Searches were performed to identify relevant scientific literature published after 1989 in English or French from 2 databases (PubMed and CAB Abstracts) and 1 search platform (Web of Science). Fifty-seven manuscripts were selected for qualitative synthesis according to the inclusion criteria. Among the 57 manuscripts selected in this review, a description of CM recurrence, its risk factors, and effects were investigated and reported in 33, 37, and 19 selected manuscripts, respectively. Meta-analysis and meta-regression analyses were used to compute risk ratio comparing risk of CM in cows that already had 1 CM event in the current lactation with risk of CM in healthy cows. For these analyses, 9 manuscripts that reported the total number of lactations followed and the number of lactations with ≤1 and ≤2 CM cases were used. When summarizing results from studies requiring ≥5 d between CM events to consider a CM event as a new case, we observed no significant change in CM susceptibility following a first CM case (risk ratio: 0.99; 95% confidence interval: 0.86-1.14). However, for studies using a more liberal CM recurrence definition (i.e., only 24 h between CM events to consider new CM cases), we observed a 1.54 times greater CM risk (95% confidence interval: 1.20-1.97) for cows that already had 1 CM event in the current lactation compared with healthy cows. The most important risk factors for CM recurrence were parity (i.e., higher risk in older cows), a higher milk production, pathogen species involved in the preceding case, and whether a bacteriological cure was observed following the preceding case. The most important effects of recurrent CM were the milk yield reduction following a recurrent CM case, which was reported to be similar to that of the first CM case, and the increased risk of culling and mortality, which were reported to surpass those of first CM cases.

Prevalence and Genetic Basis of Antimicrobial Resistance in Non-aureus Staphylococci Isolated from Canadian Dairy Herds

Emergence and spread of antimicrobial resistance is a major concern for the dairy industry worldwide. Objectives were to determine: (1) phenotypic and genotypic prevalence of drug-specific resistance for 25 species of non-aureus staphylococci, and (2) associations between presence of resistance determinants and antimicrobial resistance. Broth micro-dilution was used to determine resistance profiles for 1,702 isolates from 89 dairy herds. Additionally, 405 isolates were sequenced to screen for resistance determinants. Antimicrobial resistance was clearly species-dependent. Resistance to quinupristin/dalfopristin was common in Staphylococcus gallinarum (prevalence of 98%), whereas S. cohnii and S. arlettae were frequently resistant to erythromycin (prevalence of 63 and 100%, respectively). Prevalence of resistance was 10% against β-lactams and tetracyclines. In contrast, resistance to antimicrobials critically important for human medicine, namely vancomycin, fluoroquinolones, linezolid and daptomycin, was uncommon (< 1%). Genes encoding multidrug-resistance efflux pumps and resistance-associated residues in deducted amino acid sequences of the folP gene were the most frequent mechanisms of resistance, regardless of species. The estimated prevalence of the mecA gene was 17% for S. epidermidis. Several genes, including blaZ, mecA, fexA, erm, mphC, msrA, and tet were associated with drug-specific resistance, whereas other elements were not. There were specific residues in gyrB for all isolates of species intrinsically resistant to novobiocin. This study provided consensus protein sequences of key elements previously associated with resistance for 25 species of non-aureus staphylococci from dairy cattle. These results will be important for evaluating effects of interventions in antimicrobial use in Canadian dairy herds.

Measuring vaccine acceptance among Canadian parents: A survey of the Canadian Immunization Research Network

Parental decision making about childhood vaccinations is complex and multidimensional. There is a perception that the number of parents having concerns regarding childhood vaccinations has been increasing in Canada. The aim of this study was to explore vaccine hesitancy among Canadian parents and to examine factors associated with a parent's intention to vaccinate his/her child. Informed by the Theory of Planned Behaviour (TPB) this study assesses potential associations between parents' knowledge, attitudes and beliefs toward vaccination and their intention to vaccinate their child in the future. A national sample of Canadian parents of children aged 24-59 months (N = 2013) was surveyed using an online survey methodology. Half of the surveyed parents strongly intended to have their child vaccinated in the future. Parents' information needs and searches as well as parents' trust in different institutions were associated with intention to vaccinate. Parents who reported having frequently looked for vaccine information, who considered that it was their role as parents to question vaccines, or who had previously experienced difficulty accessing vaccination services were less likely to strongly intend to vaccinate their child in the future. Parents who had a high level of trust in doctors and public health were most likely to strongly intend to vaccinate their child. Results of the multivariate analysis showed that positive attitudes (aOR = 8.0; 95% CI: 6.0, 10.4), higher perceived social support (aOR = 3.0; 95% CI: 2.3, 3.93), and higher perceived behavioural control (aOR = 1.8; 95% CI: 1.4, 2.43) were associated with parents' intention to vaccinate their child. Findings of this study suggest that trust-building interventions that promote pro-vaccine social norms and that address negative attitudes toward vaccination could enhance vaccine acceptance among Canadian parents.

Comparison of treatment records and inventory of empty drug containers to quantify antimicrobial usage in dairy herds

Assessment of antimicrobial use (AMU) is vital for interpreting the origin of changes in antimicrobial resistance (AMR). The objectives of the present study were to estimate the association between AMU determined using on-farm treatment records (TR) and inventory of empty drug containers (INV). Herds were selected to represent Canadian dairy farms. Producers were asked to record animal health events and treatments on a standard General Health Event form. For inventory data, 40-L receptacles were placed at various locations considered convenient to deposit all empty drug containers. Antimicrobial defined-daily dosages (ADD) were calculated for 51 Canadian herds using the 2 methods. Estimation of AMU was 31,840 ADD using the INV and 14,487 ADD using the TR, indicating that for every TR entry, 2.20 times more treatments were observed using the INV. Mastitis, reproductive conditions, and dry cow therapy were the most frequent reasons for antimicrobial therapy when assessing TR. For all antimicrobials evaluated, mean ADD was higher using the INV versus TR. Regardless, a strong positive correlation (0.80) was observed between the 2 methods, indicating that herds with increased number of ADD recorded using the INV also had increased number of ADD recorded using TR. Furthermore, a positive association was observed for the 6 most commonly used antimicrobials. In comparison to methods used in surveillance programs on AMU in livestock that assume a constant use in all herds (i.e., sales data), INV provided a herd-level specific quantity of AMU positively correlated with AMU recorded at the animal level in general. The INV was easy to implement and provided a measure of total AMU in the herd. Availability of such information would be valuable for interpreting changes in AMR at the herd level and enabling evaluation of interventions for decreasing AMR.

Timeliness and completeness of routine childhood vaccinations in children by two years of age in Alberta, Canada

OBJECTIVES

Assessing timeliness and completeness of vaccine administration is important for evaluating the effectiveness of immunization programs. Few studies have reported timeliness, particularly in Canada. The objective of this study was to examine timeliness of the receipt of vaccination for each routine childhood recommended vaccine by 24 months of age among children in a community-based pregnancy cohort in Calgary, Alberta.

METHODS

Survey data from a community-based pregnancy cohort in Alberta were linked to Public Health vaccination records of children (n = 2763). The proportion of children receiving early, timely, delayed, or no vaccination was calculated. A dose was considered early if it was administered before the recommended age in days as per the vaccination schedule, timely if administered at any time from start of recommended age in days to age in days when delay counts were initiated, and delayed if it was administered on or after age in days when delay counts were initiated. Series completion rates were also calculated.

RESULTS

For multi-dose vaccines, over 80% of children had timely doses at 2, 4 and 6 months. By 12 months, this proportion decreased to 65% (95% CI: 63%-66%) for meningococcal conjugate group C, 61% (95% CI: 59%-62%) for measles antigen-containing vaccines and 64% (95% CI: 62%-65%) for varicella antigen-containing vaccines. At 18 months, only 55% (95% CI: 53%-56%) of the children had a timely 4th dose of diphtheria, acellular pertussis, tetanus, polio, and Haemophilus influenzae type b vaccine. Eventual series completion rate for all recommended vaccines was 77% (95% CI: 75%-79%).

CONCLUSION

The timeliness and completeness of routine childhood vaccination in preschool children in this community-based pregnancy cohort is lower than provincial targets. Data on timeliness of vaccination can inform further work on barriers and enablers to vaccination in order to meet provincial targets.

NEED OF IRON SUPPLEMENTATION IN GESTATIONAL DIABETES MELLITUS

Objective

Gestational diabetes mellitus (GDM) increases the foetal morbidity and mortality and there is also risk of development of type II diabetes for the mother. In pregnancy iron supplementations are given to all the females in India. Data are not available on the relationship between serum ferritin and GDM in Indian populations.

Material & Methods

Case control study was done on 90 women (30 GDM patients approx 28 weeks of gestation and 60 control subjects without GDM) referred to the tertiary care hospital at New Delhi. Ferritin was analysed by ELISA kit. They were analyzed for the correlation of ferritin with blood glucose in GDM patients.

Results

On comparison with blood glucose the levels of ferritin were statistically significantly high in GDM cases as compared to controls (p value 0.008). There was a negative correlation of ferritin with blood glucose level (r value -0.039, p value 0.794).

Discussion

Pregnancy is an equivalent of an inflammatory state and the high levels of ferritin can help in determining the need of iron supplementation given in pregnant females. Women who had high serum ferritin had the greatest risk of GDM.

Conclusion

This study suggests a possible link between elevated serum ferritin and low-grade inflammation. Further studies in larger populations are required to establish this study.

Understanding Vaccine Hesitancy in Canada: Results of a Consultation Study by the Canadian Immunization Research Network

"Vaccine hesitancy" is a concept now frequently used in vaccination discourse. The increased popularity of this concept in both academic and public health circles is challenging previously held perspectives that individual vaccination attitudes and behaviours are a simple dichotomy of accept or reject. A consultation study was designed to assess the opinions of experts and health professionals concerning the definition, scope, and causes of vaccine hesitancy in Canada. We sent online surveys to two panels (1- vaccination experts and 2- front-line vaccine providers). Two questionnaires were completed by each panel, with data from the first questionnaire informing the development of questions for the second. Our participants defined vaccine hesitancy as an attitude (doubts, concerns) as well as a behaviour (refusing some / many vaccines, delaying vaccination). Our findings also indicate that both vaccine experts and front-line vaccine providers have the perception that vaccine rates have been declining and consider vaccine hesitancy an important issue to address in Canada. Diffusion of negative information online and lack of knowledge about vaccines were identified as the key causes of vaccine hesitancy by the participants. A common understanding of vaccine hesitancy among researchers, public health experts, policymakers and health care providers will better guide interventions that can more effectively address vaccine hesitancy within Canada.

QSAR analyses of DDT analogues and their in silico validation using molecular docking study against voltage-gated sodium channel of Anopheles funestus

DDT has enjoyed the reputation of a successful pesticide in disease control programme and agricultural practices along with the serious opposition and ban later on due to its biomagnification and toxic action against non-target organisms. The present work was carried out to develop QSAR models for analysing DDT analogues for their pesticidal activity and in silico validation of these models. A 2D-QSAR model was generated using stepwise with multiple regression, and the model with a value of r(2) = 0.7324; q(2) = 0.6215; pred r(2) = 0.7038, containing five descriptors, was selected for further study. The 3D QSAR with CoMFA analysis showed that steric contribution of 21% and electrostatic contribution of about 79% were required for larvicidal activity of DDT analogues. A set of 3430 molecules was generated using the basic DDT skeleton as template, and these were evaluated for their mosquito larvicidal activity using the generated QSAR models and DDT as standard. Eleven molecules were selected for in silico validation of these models. For this, a docking study of the selected molecules against the homology-modelled voltage-gated sodium channel of Anopheles funestus was conducted. The study showed that the activities of these analogues as predicted by 2D-QSAR, 3D-QSAR with CoMFA and dock score were observed to be well correlated.

Knowledge and use of personal protective measures against mosquito borne diseases in a resettlement colony of delhi

Background:

Mosquito borne diseases (MBDs) are major public health problem in India. State of Delhi is endemic for dengue and other MBDs. The increasing incidence of MBDs in Delhi in recent years warrants a pro-active approach for their prevention. Knowledge and use of personal protective measures (PPMs) presents an effective strategy for prevention and control of MBDs.

Aim:

The present study was conducted to assess the knowledge and use of PPMs against MBDs in an urban resettlement colony of Delhi.

Subjects and Methods:

It was a cross-sectional study carried out in a resettlement colony of Delhi. A total of 100 families were selected by systematic random sampling. Data was collected using semi-structured questionnaire and supplemented by spot survey by the investigator in the community. The results were analyzed in SPSS version 16.0 (Chicago Illinios, USA).

Results:

Out of the 100 respondents, 65% (65/100), 58%(58/100) and 13% (13/100) had heard about dengue, malaria and chikungunya, respectively. Nearly, one-fifth (20/100; 20%) of the participants reported incorrect breeding sites for mosquitoes. The knowledge regarding PPMs was very high (93/100; 93%) and about (90/100; 90%) families were actually using at least one of the PPMs. However, very few families were using them correctly (1/90; 1.1%) and adequately (5/90; 5.6%). The most common PPM being used by the study population was liquid vaporizers (54/90; 60%). Nearly one-third (29/90; 32.2%) of the participants reported side-effects due to PPMs with irritation to smell being the most common reported side-effect. On house visit, adult mosquitoes were seen in 67% (67/100) of the houses, while potential mosquito breeding sites were found in and around 56% (56/100) houses.

Conclusions:

There were crucial gaps in knowledge and practices of participants with regard to prevention and control of MBDs. Thus, there is a need to intensify efforts toward creating public knowledge and mobilizing community about correct use of preventive measures against MBDs.

Ambient ozone concentrations and the risk of perforated and nonperforated appendicitis: a multicity case-crossover study

BACKGROUND

Environmental determinants of appendicitis are poorly understood. Past work suggests that air pollution may increase the risk of appendicitis.

OBJECTIVES

We investigated whether ambient ground-level ozone (O3) concentrations were associated with appendicitis and whether these associations varied between perforated and nonperforated appendicitis.

METHODS

We based this time-stratified case-crossover study on 35,811 patients hospitalized with appendicitis from 2004 to 2008 in 12 Canadian cities. Data from a national network of fixed-site monitors were used to calculate daily maximum O3 concentrations for each city. Conditional logistic regression was used to estimate city-specific odds ratios (ORs) relative to an interquartile range (IQR) increase in O3 adjusted for temperature and relative humidity. A random-effects meta-analysis was used to derive a pooled risk estimate. Stratified analyses were used to estimate associations separately for perforated and nonperforated appendicitis.

RESULTS

Overall, a 16-ppb increase in the 7-day cumulative average daily maximum O3 concentration was associated with all appendicitis cases across the 12 cities (pooled OR = 1.07; 95% CI: 1.02, 1.13). The association was stronger among patients presenting with perforated appendicitis for the 7-day average (pooled OR = 1.22; 95% CI: 1.09, 1.36) when compared with the corresponding estimate for nonperforated appendicitis [7-day average (pooled OR = 1.02, 95% CI: 0.95, 1.09)]. Heterogeneity was not statistically significant across cities for either perforated or nonperforated appendicitis (p > 0.20).

CONCLUSIONS

Higher levels of ambient O3 exposure may increase the risk of perforated appendicitis.

Antimicrobial resistance profiles of common mastitis pathogens on Canadian dairy farms

Monitoring of antimicrobial resistance (AMR) in bacteria has clinical and public health significance. The present study determined prevalence of AMR in common mastitis pathogens Staphylococcus aureus, including methicillin-resistant Staph. aureus (MRSA; n=1,810), Escherichia coli (n=394), and Klebsiella species (n=139), including extended-spectrum β-lactamase (ESBL)-producing E. coli and Klebsiella species, isolated from milk samples on 89 dairy farms in 6 Canadian provinces. Minimum inhibitory concentrations (MIC) were determined using the Sensititer bovine mastitis plate (Trek Diagnostic Systems Inc., Cleveland, OH) and a National Antimicrobial Resistance Monitoring System gram-negative panel containing antimicrobials commonly used for mastitis treatment and control. Denim blue chromogenic agar and real-time PCR were used to screen and confirm MRSA, respectively. Resistance proportion estimates ranged from 0% for cephalothin and oxacillin to 8.8% for penicillin in Staph. aureus isolates, and 15% of the resistant Staph. aureus isolates were multidrug resistant. One MRSA isolate was confirmed (prevalence: 0.05%). Resistance proportion estimates ranged from 0% for ceftriaxone and ciprofloxacin to 14.8% for tetracycline in E. coli, and 0% for amikacin, ceftiofur, ciprofloxacin, and nalidixic acid to 18.6% for tetracycline in Klebsiella species isolates. Further, 62.8 and 55% of the resistant E. coli and Klebsiella species isolates were multidrug resistant, respectively. Resistance to >5 and >2 antimicrobials was most common in E. coli and Klebsiella species isolates, respectively, and no ESBL producers were found. Prevalence of AMR in bovine mastitis pathogens was low. Most gram-negative udder pathogens were multidrug resistant; MRSA was rarely found, and ESBL E. coli and Klebsiella species isolates were absent in Canadian milk samples.

Antimicrobial use on Canadian dairy farms

Antimicrobial use (AMU) data are critical for formulating policies for containing antimicrobial resistance. The present study determined AMU on Canadian dairy farms and characterized variation in AMU based on herd-level factors such as milk production, somatic cell count, herd size, geographic region and housing type. Drug use data were collected on 89 dairy herds in 4 regions of Canada, Alberta, Ontario, Québec, and the Maritime provinces (Prince Edward Island, New Brunswick, and Nova Scotia) for an average of 540 d per herd. Dairy producers and farm personnel were asked to deposit empty drug containers into specially provided receptacles. Antimicrobial use was measured as antimicrobial drug use rate (ADUR), with the unit being number of animal defined-daily doses (ADD)/1,000 cow-days. Antimicrobial drug use rates were determined at farm, region, and national level. Combined ADUR of all antimicrobial classes was 14.35 ADD/1,000 cow-days nationally. National level ADUR of the 6 most commonly used antimicrobial drug classes, cephalosporins, penicillins, penicillin combinations, tetracyclines, trimethoprim-sulfonamide combinations, and lincosamides were 3.05, 2.56, 2.20, 1.83, 0.87, and 0.84 ADD/1,000 cow-days, respectively. Dairy herds in Ontario were higher users of third-generation cephalosporins (ceftiofur) than in Québec. Alberta dairy herds were higher users of tetracyclines in comparison to Maritimes. Antimicrobial drug use rate was higher via systemic route as compared with intramammary and other routes of administration (topical, oral, and intrauterine). The ADUR of antimicrobials used intramammarily was higher for clinical mastitis treatment than dry cow therapy. For dry cow therapy, penicillin ADUR was greater than ADUR of first-generation cephalosporins. For clinical mastitis treatment, ADUR of intramammary penicillin combinations was greater than ADUR of cephapirin. Herd-level milk production was positively associated with overall ADUR, ADUR of systemically administered ceftiofur, cephapirin administered for dry cow therapy, and pirlimycin administered for clinical mastitis treatment. Herd size and ADUR of systemically administered ceftiofur were also positively associated. In conclusion, β-lactams were most commonly used on Canadian dairy farms. Among antimicrobials of very high importance in human medicine, the use of fluoroquinolones was rare, whereas third-generation cephalosporins and penicillin combinations containing colistin were used very frequently on Canadian dairy farms.

Madurai Area Physicians Cardiovascular Health Evaluation Survey (MAPCHES)--an alarming status

BACKGROUND

Studies have shown that South Asians are highly susceptible to cardiovascular diseases (CVDs). There is very little information available about the prevalence of risk factors for CVD in the physician population, a group that might be expected to be more aware of cardiovascular risk and health status.

AIM

To evaluate the prevalence of cardiovascular risk factors - including metabolic, dietary and behavioural - among the physician population in southern India.

METHODS

Approximately 4000 physicians of differing specialties from eight southern districts in Tamilnadu, India, in and around the city of Madurai were listed. Of these, 1600 were randomly selected to participate in a cross-sectional survey, of which 1514 physicians agreed to participate. The survey included demographic questionnaires, objective measurements of blood pressure, fasting blood sugar, fasting lipids and waist circumference, and questionnaires about their dietary and behavioural habits.

RESULTS

Complete data were available for 1433 physicians. Using a blood pressure cut-off value of 130/85 mmHg or higher, the study recorded a prevalence of 41% among men and 23% among women. On applying the International Diabetes Federation criteria for the metabolic syndrome for the South Asian population, the present study identified 49% of female physicians and 41% of male physicians as having the metabolic syndrome. Only 17% were physically active. Less than one-half of them consumed vegetables. Nearly 31% of male physicians were smokers.

CONCLUSION

Analysis of these data suggests that the risk for CVD and stroke is at epidemic proportions in a cohort of well-educated physicians who are in the highest quintile of income.

Anti-inflammatory and anthelmintic activities of Solanum khasianum Clarke

In order to scientifically appraise some of the folkloric uses of Solanum khasianum Clarke (Solanaceae), the present study was undertaken to examine the anti-inflammatory and anthelmintic properties of the berries of ethanol extract. Anti-inflammatory activity was tested in carrageenan induced rat hind paw edema method at three dose level of 200, 300, and 400 mg kg(-1) respectively, Diclofenac sodium (100 mg kg(-1)) was used as the reference standard. The anti-inflammatory activity of the extract was compared with standard and control. The anthelmintic activity of the extract was tested on tape worm, liver fluke, thread worm, and hook worm using two different concentrations, 100 and 200 mg mL(-1) respectively. Time taken for the inhibition of motility was noted and compared with the standard drug, Piperazine citrate 15 mg mL. The plant extract significantly (p < 0.01) reduced the inflammation of the rats when compared to the control group. Also, the ethanol extract of the plant paralyzed the worms followed by death, which was comparable with that of the standard. This study supports the folk claim.

Tunable optical properties of colloidal quantum dots in electrolytic environments

The absorption spectra of colloidal cadmium sulfide quantum dots in electrolytic solutions are found to manifest a shift in the absorption threshold as the concentration of the electrolyte is varied. These results are consistent with a shift in the absorption threshold that would be caused by electrolytic screening of the field caused by the intrinsic spontaneous polarisation of these würtzite structured quantum dots. These electrolyte-dependent absorption properties provide a potential means of gaining insights on the variable extracellular and intracellular electrolytic concentrations that are present in biological systems.

Wood-smoke exposure: an unusual cause of miliary mottling on X-ray chest

A case of wood smoke inhalation related lung disease presenting with miliary mottling on radiography is described. Transbronchial lung biopsy showed the presence of coal macules.

Mediastinal widening in a patient of ulcerative colitis

A case of ulcertaive colitis on long-term corticosteroid therapy presenting with mediastinal widening and diagnosed to have mediastinal lipomatosis an thoracic computed tomography is presented.

Tuberculous parotitis: a series of five cases diagnosed on fine needle aspiration cytology

Parotid gland tuberculosis is still a rare entity and has mostly been diagnosed after parotidectomy. We present five cases which were diagnosed on fine needle aspiration cytology (FNAC) and managed medically avoiding surgical intervention.

Activation of the Ras-GRF/CDC25Mm exchange factor by lysophosphatidic acid

The Ras-GRF exchange factor can activate Ras-dependent responses following the activation of heterotrimeric G-protein and calcium signalling. In stable lines of NIH-3T3 fibroblasts that express Ras-GRF, the agonist lysophosphatidic acid (LPA) increases the phosphorylation state and activity of Ras-GRF. The stimulation of Ras-GRF can be demonstrated in vitro, in an assay using recombinant Ras substrate, and in situ, by a selective increase in the ability of LPA to stimulate mitogen-activated protein (MAP) kinase. The increase in Ras-GRF phosphorylation state, which occurs on serine residues, and the increase in exchange factor activity are blocked by pretreatment with pertussis toxin. Activation of Ras-GRF by LPA can also be inhibited by chelation of intracellular calcium and treatment of the Ras-GRF with protein phosphatase 1 (PP1), supporting a model in which Ras-GRF serves to integrate signals from multiple transduction pathways.

Poisoning in children: Indian scenario

The retrospective data on childhood poisoning from eight regional hospitals in India has been reviewed. The demographic features and types of poisonings encountered have been compared. The analysis of the data indicated that pediatric poisonings constituted 0.23-3.3% of the total poisoning. The mortality ranged from 0.64-11.6% with highest being from Shimla. Accidental poisoning was common involving 50-90% of children below 5 years of age and males outnumbered the females. Suicidal poisoning was seen after 13 years of age and was due to drugs and household chemicals. One of the hospitals in Delhi recorded a very high incidence (66.6%) of drug poisoning in children. The drugs consumed belonged to phenothiazines, antiepileptics and antipyretics. Iron poisoning was seen in younger children. Kerosene was one of the causes of accidental poisoning at all hospitals except Shimla and rural Maharashtra were probably wood charcoal is widely used. Pesticide poisoning was more prevalent in Punjab and West Bengal whereas plant poisoning was very common in Shimla. Significant number of snake envenomation has been recorded from rural Maharashtra. Other less common accidental poisonings in children included alcohol, corrosives, heavy metals, rodenticides, detergents and disinfectants. Thus various regions in the country showed some variation in types and frequency of childhood poisoning which could be attributed to different geographical and socio-economic background.