Clinical Practice Guideline Recommendations in Pediatric Mild Traumatic Brain Injury: A Systematic Review

STUDY OBJECTIVE

Our primary objectives were to identify clinical practice guideline recommendations for children with acute mild traumatic brain injury (mTBI) presenting to an emergency department (ED), appraise their overall quality, and synthesize the quality of evidence and the strength of included recommendations.

METHODS

We searched MEDLINE, EMBASE, Cochrane Central, Web of Science, and medical association websites from January 2012 to May 2023 for clinical practice guidelines with at least 1 recommendation targeting pediatric mTBI populations presenting to the ED within 48 hours of injury for any diagnostic or therapeutic intervention in the acute phase of care (ED and inhospital). Pairs of reviewers independently assessed overall clinical practice guideline quality using the Appraisal of Guidelines Research and Evaluation (AGREE) II tool. The quality of evidence on recommendations was synthesized using a matrix based on the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) Evidence-to-Decision framework.

RESULTS

We included 11 clinical practice guidelines, of which 6 (55%) were rated high quality. These included 101 recommendations, of which 34 (34%) were based on moderate- to high-quality evidence, covering initial assessment, initial diagnostic imaging, monitoring/observation, therapeutic interventions, discharge advice, follow-up, and patient and family support. We did not identify any evidence-based recommendations in high-quality clinical practice guidelines for repeat imaging, neurosurgical consultation, or hospital admission. Lack of strategies and tools to aid implementation and editorial independence were the most common methodological weaknesses.

CONCLUSIONS

We identified 34 recommendations based on moderate- to high-quality evidence that may be considered for implementation in clinical settings. Our review highlights important areas for future research. This review also underlines the importance of providing strategies to facilitate the implementation of clinical practice guideline recommendations for pediatric mTBI.

Social determinants of health and disparities in pediatric trauma care: protocol for a systematic review and meta-analysis

BACKGROUND

Social determinants of health (SDH), including "the conditions in which individuals are born, grow, work, live and age" affect child health and well-being. Several studies have synthesized evidence about the influence of SDH on childhood injury risks and outcomes. However, there is no systematic evidence about the impact of SDH on accessing care and quality of care once a child has suffered an injury. We aim to evaluate the extent to which access to care and quality of care after injury are affected by children and adolescents' SDH.

METHODS

Using Cochrane methodology, we will conduct a systematic review including observational and experimental studies evaluating the association between social/material elements contributing to health disparities, using the PROGRESS-Plus framework: place of residence, race/ethnicity/culture/language, occupation, gender/sex, religion, education, socioeconomic status, and social capital and care received by children and adolescents (≤ 19 years of age) after injury. We will consult published literature using PubMed, EMBASE, CINAHL, PsycINFO, Web of Science, and Academic Search Premier and grey literature using Google Scholar from their inception to a maximum of 6 months prior to submission for publication. Two reviewers will independently perform study selection, data extraction, and risk of bias assessment for included studies. The risk of bias will be assessed using the ROBINS-E and ROB-2 tools respectively for observational and experimental study designs. We will analyze data to perform narrative syntheses, and if enough studies are identified, we will conduct a meta-analysis using random effects models.

DISCUSSION

This systematic review will provide a synthesis of evidence on the association between SDH and pediatric trauma care (access to care and quality of care) that clinicians and policymakers can use to better tailor care systems and promote equitable access and quality of care for all children. We will share our findings through clinical rounds, conferences, and publication in a peer-reviewed journal.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42023408467.

Clinical Practice Guideline Recommendations For Pediatric Multisystem Trauma Care: A Systematic Review

OBJECTIVE

To systematically review clinical practice guidelines (CPGs) for pediatric multisystem trauma, appraise their quality, synthesize the strength of recommendations and quality of evidence, and identify knowledge gaps.

BACKGROUND

Traumatic injuries are the leading cause of death and disability in children, who require a specific approach to injury care. Difficulties integrating CPG recommendations may cause observed practice and outcome variation in pediatric trauma care.

METHODS

We conducted a systematic review using Medline, Embase, Cochrane Library, Web of Science, ClinicalTrials, and grey literature, from January 2007 to November 2022. We included CPGs targeting pediatric multisystem trauma with recommendations on any acute care diagnostic or therapeutic interventions. Pairs of reviewers independently screened articles, extracted data, and evaluated the quality of CPGs using "Appraisal of Guidelines, Research, and Evaluation II."

RESULTS

We reviewed 19 CPGs, and 11 were considered high quality. Lack of stakeholder engagement and implementation strategies were weaknesses in guideline development. We extracted 64 recommendations: 6 (9%) on trauma readiness and patient transfer, 24 (38%) on resuscitation, 22 (34%) on diagnostic imaging, 3 (5%) on pain management, 6 (9%) on ongoing inpatient care, and 3 (5%) on patient and family support. Forty-two (66%) recommendations were strong or moderate, but only 5 (8%) were based on high-quality evidence. We did not identify recommendations on trauma survey assessment, spinal motion restriction, inpatient rehabilitation, mental health management, or discharge planning.

CONCLUSIONS

We identified 5 recommendations for pediatric multisystem trauma with high-quality evidence. Organizations could improve CPGs by engaging all relevant stakeholders and considering barriers to implementation. There is a need for robust pediatric trauma research, to support recommendations.

Clinical Practice Guideline Recommendations in Pediatric Orthopaedic Injury: A Systematic Review

BACKGROUND

Lack of adherence to recommendations on pediatric orthopaedic injury care may be driven by lack of knowledge of clinical practice guidelines (CPGs), heterogeneity in recommendations or concerns about their quality. We aimed to identify CPGs for pediatric orthopaedic injury care, appraise their quality, and synthesize the quality of evidence and the strength of associated recommendations.

METHODS

We searched Medline, Embase, Cochrane CENTRAL, Web of Science and websites of clinical organizations. CPGs including at least one recommendation targeting pediatric orthopaedic injury populations on any diagnostic or therapeutic intervention developed in the last 15 years were eligible. Pairs of reviewers independently extracted data and evaluated CPG quality using the Appraisal of Guidelines Research and Evaluation (AGREE) II tool. We synthesized recommendations from high-quality CPGs using a recommendations matrix based on the GRADE Evidence-to-Decision framework.

RESULTS

We included 13 eligible CPGs, of which 7 were rated high quality. Lack of stakeholder involvement and applicability (i.e., implementation strategies) were identified as weaknesses. We extracted 53 recommendations of which 19 were based on moderate or high-quality evidence.

CONCLUSIONS

We provide a synthesis of recommendations from high-quality CPGs that can be used by clinicians to guide treatment decisions. Future CPGs should aim to use a partnership approach with all key stakeholders and provide strategies to facilitate implementation. This study also highlights the need for more rigorous research on pediatric orthopaedic trauma.

LEVEL OF EVIDENCE

Level II-therapeutic study.

Pediatric Moderate and Severe Traumatic Brain Injury: A Systematic Review of Clinical Practice Guideline Recommendations

Traumatic brain injury (TBI) is the leading cause of death and disability in children. Many clinical practice guidelines (CPGs) have addressed pediatric TBI in the last decade but significant variability in the use of these guidelines persists. Here, we systematically review CPGs recommendations for pediatric moderate-to-severe TBI, evaluate the quality of CPGs, synthesize the quality of evidence and strength of included recommendations, and identify knowledge gaps. A systematic search was conducted in MEDLINE®, Embase, Cochrane CENTRAL, Web of Science, and Web sites of organizations publishing recommendations on pediatric injury care. We included CPGs developed in high-income countries from January 2012 to May 2023, with at least one recommendation targeting pediatric (≤ 19 years old) moderate-to-severe TBI populations. The quality of included clinical practice guidelines was assessed using the AGREE II tool. We synthesized evidence on recommendations using a matrix based on the Grading of Recommendations Assessment, Development and Evaluation (GRADE) framework. We identified 15 CPGs of which 9 were rated moderate to high quality using AGREE II. We identified 90 recommendations, of which 40 (45%) were evidence based. Eleven of these were based on moderate to high quality evidence and were graded as moderate or strong by at least one guideline. These included transfer, imaging, intracranial pressure control, and discharge advice. We identified gaps in evidence-based recommendations for red blood cell transfusion, plasma and platelet transfusion, thromboprophylaxis, surgical antimicrobial prophylaxis, early diagnosis of hypopituitarism, and mental health mangement. Many up-to-date CPGs are available, but there is a paucity of evidence to support recommendations, highlighting the urgent need for robust clinical research in this vulnerable population. Our results may be used by clinicians to identify recommendations based on the highest level of evidence, by healthcare administrators to inform guideline implementation in clinical settings, by researchers to identify areas where robust evidence is needed, and by guideline writing groups to inform the updating of existing guidelines or the development of new ones.

Pediatric vs Adult or Mixed Trauma Centers in Children Admitted to Hospitals Following Trauma: A Systematic Review and Meta-Analysis

Importance

Adult trauma centers (ATCs) have been shown to decrease injury mortality and morbidity in major trauma, but a synthesis of evidence for pediatric trauma centers (PTCs) is lacking.

Objective

To assess the effectiveness of PTCs compared with ATCs, combined trauma centers (CTCs), or nondesignated hospitals in reducing mortality and morbidity among children admitted to hospitals following trauma.

Data Sources

MEDLINE, Embase, and Web of Science through March 2023.

Study Selection

Studies comparing PTCs with ATCs, CTCs, or nondesignated hospitals for pediatric trauma populations (aged ≤19 years).

Data Extraction and Synthesis

This systematic review and meta-analysis was performed following the Preferred Reporting Items for Systematic Review and Meta-analysis and Meta-analysis of Observational Studies in Epidemiology guidelines. Pairs of reviewers independently extracted data and evaluated risk of bias using the Risk of Bias in Nonrandomized Studies of Interventions tool. A meta-analysis was conducted if more than 2 studies evaluated the same intervention-comparator-outcome and controlled minimally for age and injury severity. Subgroup analyses were planned for age, injury type and severity, trauma center designation level and verification body, country, and year of conduct. Grading of Recommendations Assessment, Development, and Evaluation (GRADE) was used to assess certainty of evidence.

Main Outcome(s) and Measure(s)

Primary outcomes were mortality, complications, functional status, discharge destination, and quality of life. Secondary outcomes were resource use and processes of care, including computed tomography (CT) and operative management of blunt solid organ injury (SOI).

Results

A total of 56 studies with 286 051 participants were included overall, and 34 were included in the meta-analysis. When compared with ATCs, PTCs were associated with a 41% lower risk of mortality (OR, 0.59; 95% CI, 0.46-0.76), a 52% lower risk of CT use (OR, 0.48; 95% CI, 0.26-0.89) and a 64% lower risk of operative management for blunt SOI (OR, 0.36; 95% CI, 0.23-0.57). The OR for complications was 0.80 (95% CI, 0.41-1.56). There was no association for mortality for older children (OR, 0.71; 95% CI, 0.47-1.06), and the association was closer to the null when PTCs were compared with CTCs (OR, 0.73; 95% CI, 0.53-0.99). Results remained similar for other subgroup analyses. GRADE certainty of evidence was very low for all outcomes.

Conclusions and Relevance

In this systematic review and meta-analysis, results suggested that PTCs were associated with lower odds of mortality, CT use, and operative management for SOI than ATCs for children admitted to hospitals following trauma, but certainty of evidence was very low. Future studies should strive to address selection and confounding biases.

Clinical practice guideline recommendations for pediatric solid organ injury care: A Systematic Review

BACKGROUND

Observed variations in the management of pediatric solid organ injuries (SOIs) may be due to difficulty in finding and integrating recommendations from multiple clinical practice guidelines (CPGs) with heterogeneous methodological approaches. We aimed to systematically review CPG recommendations for pediatric SOIs.

METHODS

We conducted a systematic review of CPGs including at least one recommendation targeting pediatric SOI populations, using Medical Analysis and Retrieval System Online, Excerpta Medica dataBASE, Web of Science, and websites of clinical organizations. Pairs of reviewers independently assessed eligibility, extracted data, and evaluated the quality of CPGs using the Appraisal of Guidelines Research and Evaluation II tool. We synthesized recommendations from moderate to high-quality CPGs using a recommendations matrix based on Grades of Recommendation, Assessment, Development, and Evaluation criteria.

RESULTS

We identified eight CPGs, including three rated moderate or high quality. Methodological weaknesses included lack of stakeholder involvement beyond surgeons, consideration of applicability (e.g., implementation tools), and clarity around the definition of pediatric populations. Five of the 15 recommendations from moderate to high-quality CPGs were based on moderate quality evidence or were rated as strong; these reflected nonoperative management and angioembolization for renal injuries and required length of stay for liver and spleen injuries.

CONCLUSION

We identified 15 recommendations on pediatric SOI management from 3 moderate or high-quality CPGs, but only one third were based on at least moderate-quality evidence or were rated as strong. Our results prompt the following recommendations for future CPG development or updates: (1) include all types of clinicians involved in the care of pediatric SOIs and patient and family representatives in the process, (2) develop clear definitions of the target population, and (3) provide advice and tools to promote implementation. Results also underline the urgent need for more rigorous research to support strong evidence-based recommendations in this population.

LEVEL OF EVIDENCE

Systematic Review/Meta-analysis; Level III.

Clinical practice guideline recommendations for pediatric injury care: protocol for a systematic review

INTRODUCTION

Evidence suggests the presence of deficiencies in the quality of care provided to up to half of all paediatric trauma patients in Canada, the USA and Australia. Lack of adherence to evidence-based recommendations may be driven by lack of knowledge of clinical practice guidelines (CPGs), heterogeneity in recommendations or concerns about their quality. We aim to systematically review CPG recommendations for paediatric injury care and appraise their quality.

METHODS AND ANALYSIS

We will identify CPG recommendations through a comprehensive search strategy including Medical Literature Analysis and Retrieval System Online, Excerpta Medica dataBASE, Cochrane library, Web of Science, ClinicalTrials and websites of organisations publishing recommendations on paediatric injury care. We will consider CPGs including at least one recommendation targeting paediatric injury populations on any diagnostic or therapeutic intervention from the acute phase of care with any comparator developed in high-income countries in the last 15 years (January 2007 to a maximum of 6 months prior to submission). Pairs of reviewers will independently screen titles, abstracts and full text of eligible articles, extract data and evaluate the quality of CPGs and their recommendations using Appraisal of Guidelines Research and Evaluation (AGREE) II and AGREE Recommendations Excellence instruments, respectively. We will synthesise evidence on recommendations using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) Evidence-to-Decision framework and present results within a recommendations matrix.

ETHICS AND DISSEMINATION

Ethics approval is not a requirement as this study is based on available published data. The results of this systematic review will be published in a peer-reviewed journal, presented at international scientific meetings and distributed to healthcare providers.

PROSPERO REGISTRATION NUMBER

International Prospective Register of Systematic Reviews (CRD42021226934).

Socio-demographic and substance use characteristics of unintentional injuries among Nunavik youth

This study described the distribution of unintentional injuries among Inuit youth in Nunavik, Quebec, Canada, and examined the relationship between socio-demographic factors, substance use and unintentional injuries.

A cross-sectional study design was used on data collected for the Nunavik Child Development Study (2013–2015) among eligible youth aged 16 to 21 years old. Unintentional injury occurrence and causes (last 12 months) were assessed through individual interviews. A multivariate logistic regression model tested the relationship between socio-demographic, substance use variables and unintentional injury occurrence.

Among the 199 youth who participated (94% response rate), thirty youth reported being unintentionally injured in the past 12 months , of which 50% were female. All-terrain vehicle collisions were the most frequent injuries reported (23%). The odds of being injured decreased by 62% for youth who were currently employed compared to those who were unemployed, adjusting for other socio-demographic variables (p-value = 0.04). Heavy alcohol drinking in the past 12 months was not significantly associated with unintentional injury.

This study highlights the burden of unintentional injuries among Nunavik youth and the need for future work to explore additional and diverse variables that may prevent or contribute to injuries in order to inform culturally and developmentally-appropriate injury prevention strategies.

Longitudinal cohort study of injury type, settings, treatment and costs in British Columbia youth, 2003-2013

BACKGROUND

In 2010 in British Columbia (BC), Canada, total injury costs per capita were higher among youth aged 15-24 years than in any other age group. Injury prevention efforts have targeted injuries with high mortality (transportation injuries) or morbidity (concussions). However, the profile and health costs of common youth injuries (types, locations, treatment choices and prevention strategies) and how these change from adolescence to young adulthood is not known.

METHODS

Participants (n=662) were a randomly recruited cohort of BC youth, aged 12-18, in 2003. They were followed biennially across a decade (six assessments).

RESULTS

Serious injuries (defined as serious enough to limit normal daily activities) in the last year were reported by 27%-41% of participants at each assessment. Most common injuries were sprains or strains, broken bones, cuts, punctures or animal bites, and severe bruises. Most occurred when playing a sport or from falling. Estimated total direct cost of treatment per injury was approximately $2500. In addition, 25% experienced serious injuries at three or more assessments, indicating possible differences that warrents further investigation.

CONCLUSIONS

The occurence and health cost of common injuries to youth and young adults are underestimated in this study but are nevertheless substantial. Ongoing surveillence, awareness raising, and prevention efforts may be needed to reduce these costs.

The Economics of Burn Injuries Among Children Aged 0 to 4 Years in British Columbia

Children under the age of 5 years have the highest rate of hospitalization and mortality from burns. Studies of costs associated with pediatric burns have included a limited number of patients and focused on inpatient and complication costs, limiting our understanding of the full economic burden of pediatric burns. This study aimed to develop a costing model for burn injuries among children to estimate the economic burden of child burns in British Columbia, Canada. Costs of services and resources used by children aged 0 to 4 years old who were treated at BC Children's Hospital (BCCH) between January 1, 2014 and March 15, 2018 for a burn injury were estimated and summed, using a micro-costing approach. The average cost of burn injuries per percentage of total body surface area (%TBSA) was then applied to the number of 0 to 4 years old children treated for a burn injury across British Columbia between January 1 and December 31, 2016. Based on 342 included children, a 1-5%, 6-10%, 11-20%, and >20% burn, respectively cost an average of $3338.80, $13,460.00, $20,228.80, and $109,881.00 to society. The societal cost of child burns in BC in 2016 totaled $2,711,255.01. In conclusion, pediatric burn injuries place an important, yet preventable economic burden on society. Preventing even a small number of severe pediatric burns or multiple small burns may have considerable economic impacts on society and allow for the reallocation of healthcare funds toward other clinical priorities.

State-of-the-art review: preventing child and youth pedestrian motor vehicle collisions: critical issues and future directions

Aim

To undertake a comprehensive review of the best available evidence related to risk factors for child pedestrian motor vehicle collision (PMVC), as well as identification of established and emerging prevention strategies.

Methods

Articles on risk factors were identified through a search of English language publications listed in Medline, Embase, Transport, SafetyLit, Web of Science, CINHAL, Scopus and PsycINFO within the last 30 years (~1989 onwards).

Results

This state-of-the-art review uses the road safety Safe System approach as a new lens to examine three risk factor domains affecting child pedestrian safety (built environment, drivers and vehicles) and four cross-cutting critical issues (reliable collision and exposure data, evaluation of interventions, evidence-based policy and intersectoral collaboration).

Conclusions

Research conducted over the past 30 years has reported extensively on child PMVC risk factors. The challenge facing us now is how to move these findings into action and intervene to reduce the child PMVC injury and fatality rates worldwide.

Inequities in Pediatric Abusive Head Trauma According to Neighborhood Social and Material Deprivation: A Population-Level Study in British Columbia, Canada

OBJECTIVES

To explore the relationship between neighborhood social and material deprivation and the rates of abusive head trauma (AHT), and whether it differs according to sex, and following the implementation of the Period of PURPLE Crying (PURPLE) program.

METHOD

A cross-sectional study design was applied to data from children 0 to 24 months old with a confirmed AHT diagnosis between 2005 and 2017 in British Columbia. Dissemination area-based social and material deprivation scores were assigned to residential areas, where AHT cases were recorded. Poisson regression models tested the relationship between deprivation scores and AHT rates, adding sex and pre-post program implementation as interaction terms.

RESULTS

With each increase in material and social deprivation quintiles, AHT rates increased by 42% (95% CI [1.18, 1.72]) and 25% (95% CI [1.06, 1.51]), respectively, following a social gradient. AHT rate disparities between neighborhoods did not change following the PURPLE program implementation.

CONCLUSIONS

This study stresses the need to provide additional AHT prevention services proportionately to the levels of neighborhood disadvantage, in addition to universal AHT programs, to successfully protect all children.

The lifetime costs of pediatric abusive head trauma and a cost-effectiveness analysis of the Period of Purple crying program in British Columbia, Canada

BACKGROUND

Abusive head trauma (AHT) is a severe form of child abuse causing devastating outcomes for children and families, but its economic costs in Canada has yet to be determined. The Period of PURPLE crying program (PURPLE) is an AHT prevention program implemented in British Columbia for which success in reducing AHT events was recently reported.

OBJECTIVE

This study estimated the lifetime costs to society of incidental AHT events and compared the benefits and associated costs of AHT before and after the implementation of the PURPLE program.

PARTICIPANTS AND SETTING

Children aged 0-24 months old with a definite diagnosis of AHT between 2002 and 2014 in British Columbia were included in this study.

METHODS

An incidence-based cost-of-illness analysis, using the human capital approach was used to quantify the lifetime costs of AHT events according to their severity (least severe, severe and fatal). A cost-effectiveness analysis of the PURPLE program was conducted from both a societal and a health services' perspectives using decision tree models.

RESULTS

There were sixty-four AHT events between 2002-2014, resulting in a total cost of $354,359,080 to society. The costs associated with fatal, severe and least severe AHT averaged $7,147,548, $6,057,761 and $1,675,099, respectively. The investment of $5 per newborn through the PURPLE program resulted in a $273.52 and $14.49 per child cost avoidance by society and by the healthcare system.

CONCLUSIONS

This study provides evidence to policymakers and health practitioners that investing upstream in well-developed AHT prevention programs, such as PURPLE, not only promote child safety and health, but also translates into avoided costs to society.

The geographic and demographic distribution of residential fires, related injuries, and deaths in four Canadian provinces

OBJECTIVE

A considerable number of Canadians are injured or killed every year as a result of residential fires. Until recently, the absence of representative national data limited our understanding of the current situation. This study used a novel dataset to describe the geographic and demographic distribution of residential fires and related casualties across 4 Canadian provinces and to explore changes over time.

METHODS

A cross-sectional study design was applied to data from the National Fire Information Database, which reported fire incidents, locations, and associated casualties attended by a fire service across 4 Canadian provinces between 2005 and 2015. Residential fire incident, injury, and death rates were described and compared between sex and age groups. Simple linear regressions were used to assess the trends of casualty rates per population and per fire incidents over time.

RESULTS

A total of 145,252 residential fires were reported for the provinces of British Columbia, Alberta, Manitoba, and Ontario, of which 5.5% resulted in casualties. Death and severe injury rates per population decreased significantly between 2005 and 2015, while casualties per 1000 house fires did not change. Death rates per house fire incidents were generally higher in urban than in remote areas but tended to increase as distance from city centres increased and moved closer to suburban areas. Injury rates were higher than death rates for all age groups and significantly higher for males than for females.

CONCLUSION

These findings represent an important step forward in identifying the most vulnerable municipalities and populations to inform evidence-based cross-provincial efforts to reduce the societal burden of residential fires.

Association between neighbourhood socioeconomic features and residential fire incidence, related casualties and children: a cross-sectional population-based study in 4 Canadian provinces

BACKGROUND

This study assessed whether socioeconomic factors affect the rates of residential fire incidence and fire-related injuries and deaths, and whether children are affected differently than the general population.

METHODS

We employed a cross-sectional study design using data for British Columbia, Alberta, Manitoba and Ontario from the National Fire Information Database, which includes fire incidents and losses reported by provincial fire marshals across Canada between 2005 and 2015. It also contains 2011 census subdivision social domain data from Statistics Canada based on fire location. Multivariable negative binomial regressions tested the significance of relations between census subdivision socioeconomic factors (average household size, educational attainment, median income and unemployment rate) and the rates of residential fires and casualties per person-year, and casualties per fire incident.

RESULTS

Census subdivisions with higher educational attainment and unemployment rates had higher rates of residential fires (incidence rate ratio [IRR] 1.07, 95% confidence interval [CI] 1.05-1.10, and IRR 1.24, 95% CI 1.18-1.31, respectively) and of residential fire casualties per person-year (IRR 1.09, 95% CI 1.05-1.13, and IRR 1.29, 95% CI 1.20-1.40, respectively). Census subdivisions with smaller average households had higher rates of residential fire casualties per person-year (IRR 0.43, 95% CI 0.22-0.83) and per fire incident (IRR 0.75, 95% CI 0.58-0.97), and the association was even stronger for children (IRR 0.17, 95% CI 0.08-0.36, and IRR 0.41, 95% CI 0.20-0.86, respectively).

INTERPRETATION

The results suggest that efforts to prevent residential fires should be prioritized in neighbourhoods with higher educational attainment and unemployment, whereas house fire safety programs should be intensified in neighbourhoods with smaller households to prevent fire casualties, especially among children, once a fire does occur.

Cord blood neutropenia is an independent predictor of early sepsis

OBJECTIVE

The significance of cord blood neutropenia as a screening tool for early-onset sepsis (EOS) is unclear. The objectives were to define reference values for cord blood neutrophil count and to determine the sensitivity and positive likelihood ratio of cord neutropenia for the detection of EOS.

STUDY DESIGN

This retrospective observational cohort study included all mother-infant pairs with deliveries between 2009 and 2014 for whom cord neutrophil counts were routinely done. EOS cases were identified by interrogation of electronic charts. Maternal and perinatal factors were assessed to determine reference values of cord neutrophil. The diagnostic value of neutropenia for detecting EOS was assessed. A nested case-control design was used to measure the value of neutropenia in the detection of EOS in comparison with other risk factors.

RESULTS

A total of 8,590 mother-infant pairs were included. We identified 84 sepsis cases. The neutrophil count was strongly associated with gestational age. Neutropenia adjusted for gestational age was strongly associated with EOS and had good specificity but poor sensitivity. The addition of neutropenia to other EOS risk factors increased sensitivity without decreasing specificity.

CONCLUSION

Cord blood neutropenia was significantly associated with EOS and the addition of cord neutropenia to current EOS risk factors increased the detection rate of EOS.

Evaluation of a Child Safety Program Based on the Safe Community Model in Canada

BACKGROUND: Despite national safety programs, unintentional injuries remain an important health problem in children and adolescents. Cycling, pedestrian and young drivers injuries are particularly influenced by specific community and city aspects. The World Health Organization (WHO) developed community based programs that have been effectively implemented as complements to national safety programs to prevent injuries.

OBJECTIVES: The aim of this study was to evaluate the effectiveness of a local program based on a WHO Safe Community model to reduce cycling, pedestrian and young drivers injuries.

DESIGN/METHODS: A population based quasi-experimental design was used. Pre-implementation and post-implementation data of cycling and pedestrian injury rates (0-15 years) and young drivers injury rates (16-24 years) were collected in the intervention area (Sherbrooke) and in two control communities (Trois-Rivières and Gatineau) in Québec, Canada. RESULTS: Sherbrooke, Gatineau and Trois-Rivières had respectively 69, 82 and 119 cycling and pedestrian injury rate per 100000 children-year in the pre implementation period. Despite its already lower pre-implementation rate, Sherbrooke showed a statistically significant reduction in the post-implementation injury rate compared to Trois-Rivières (Sherbrooke: 49:100000 children-year (OR comparing pre-post rates 0.70 ; 95%CI : 0.45-1.08) and Trois-Rivières 80:100000 children-year (OR comparing pre-post rates 0.68; 95%CI: 0.46-1.0). Gatineau showed a cycling and pedestrian post-implementation injury rate of 63:100000 (OR 0.77; 95%CI: 0.58-1.02). Sherbrooke had the largest young drivers injury reduction with rates of 2912:100000 young driver-year (pre) to 2121: 100000 young driver-year (post) (OR 0.73; 95%CI: 0.66-0.8). Gatineau and Trois-Rivieres showed respectively young drivers injury rate lowering from 2383: 100000 to 2099: 100000 young driver-year (OR 0.88; 95%CI: 0.81-0.95) and from 3447: 100000 to 3295: 100000 young driver-year (OR 0.96; 95%CI 0.87-1.05).

CONCLUSION: Safe Community program established in Sherbrooke was associated with favorable results in injury prevention. Despite its lower pedestrian and cycling injury rate before the intervention, post-implementation injury rate in Sherbrooke was significantly lower compared to Trois-Rivieres. Concerning young drivers injury rates, Sherbrooke showed the biggest reduction, compared to Trois-Riviere and Gatineau. In addition to national injury prevention programs, communities should be encouraged to adopt WHO safe community programs to reduce to a minimum unintentional injury rates in children and adolescents.

Glucocorticoid-induced leucine zipper governs the therapeutic potential of mesenchymal stem cells by inducing a switch from pathogenic to regulatory Th17 cells in a mouse model of collagen-induced arthritis

OBJECTIVE

Mesenchymal stem cells (MSCs) are potent immunosuppressive cells that have shown promise in the treatment of rheumatoid arthritis (RA). Deciphering the intrinsic characteristics of MSCs that correlate with their biologic activity will facilitate their clinical use. Recently, the role of glucocorticoid-induced leucine zipper (GILZ) in the development of RA has been documented. The aim of this study was to evaluate whether GILZ expression by MSCs may contribute to their therapeutic effect.

METHODS

MSCs were isolated from GILZ-deficient (GILZ(-/-) ) mice and wild-type mice. MSCs (1 × 10(6) cells) were injected twice via the tail vein into mice with collagen-induced arthritis (CIA).

RESULTS

In vitro, we showed that GILZ is a key factor involved in the immunosuppressive potential of MSCs. MSCs derived from GILZ(-/-) mice did not suppress the proliferation of CD4+ T cells and were less efficient than MSCs derived from WT mice in altering Th17 cell polarization. Thus, we investigated the role of GILZ in an experimental model of arthritis and demonstrated that although WT MSCs significantly reduced paw swelling in arthritic mice, GILZ(-/-) MSCs did not. Moreover, the magnitude of the effects of GILZ(-/-) MSCs on Th17 cell frequency was significantly lower than that of WT MSCs. The therapeutic effect of MSCs correlated with the generation of Treg cells bearing the CD4 + RORγt+IL-17(low) IL-10+ signature, and Th17 cell polarization was GILZ dependent.

CONCLUSION

This study demonstrates that GILZ has an essential role in the therapeutic effectiveness of MSCs in arthritis by favoring Th17 cell polarization toward a regulatory phenotype. Therefore, potentiation of GILZ expression in MSCs could represent a means to enhance their therapeutic effect in autoimmune diseases.

Adolescents' comfort answering questions about sexuality asked by their physicians

OBJECTIVE

To evaluate the attitudes of adolescents toward communicating with their doctor about different aspects of their sexuality.

METHODS

The present descriptive survey was conducted with the participation of teenagers from four high schools in Sherbrooke, Quebec. In each school, the students of two grade 8 classes (≤14 years of age) and two grade 10 classes (≥15 years of age) anonymously completed a self-administered questionnaire. Permission from the school board and parental consent for every participant was obtained.

RESULTS

A total of 387 adolescents completed the self-administered questionnaire. The response rate for the study was 98%. Only 27% of the respondents remembered being questioned by their doctor about sexuality, and 17% of the respondents had already brought up the topic of sexuality themselves with their doctor. More than one-half (57%) of the adolescents reported they would be moderately comfortable to totally comfortable discussing sexuality with their doctor if they felt the need to. Overall, when asked to evaluate their degree of comfort if questioned on specific questions about their sexuality, 73.8% to 99.5% believed they would be moderately to totally comfortable responding. Nevertheless, there was a statistically significant difference between age groups, with the older age group being more comfortable than the younger age group (P<0.001). There was no difference between the level of comfort among boys and girls answering the same questions. Respondents believed that their treating physician should discuss sexuality with them (73.8%) and, in the majority of cases (78%), that he/she should initiate the conversation.

CONCLUSION

Regardless of age or sex, teenagers considered themselves to be at ease discussing sexuality with their doctor and found it an important topic best brought up by their practitioner.

Chronic agomelatine administration modulates neuronal plasticity markers in the rat prefrontal cortex, hippocampus and amygdala

Neuronal plasticity alterations including cytoskeletal dynamics and synaptic markers have been recently associated with the treatment of major depression. Here we investigated the effects of agomelatine, a novel antidepressant with melatonergic (MT1/MT2) agonist and 5-HT2C receptor antagonist properties, on cytoskeletal microtubular proteins and synaptic markers in the rat hippocampus, prefrontal cortex (PFC) and amygdala.

Adult male Sprague Dawley rats received daily i.p. administration of hydroxyethylcellulose 1% (vehicle) or agomelatine (40mg/kg) for 22 days. The rats were then sacrificed and hippocampi, PFC and amygdala dissected for analyses of microtubule dynamics markers (Tyr/Glu-Tub, Delta2-Tub and Acet-Tub) and synaptic markers (synaptophysin, PSD-95 and spinophilin) by Western blot.

In the PFC, agomelatine decreased Tyr/Glu-Tub and the neuronal-specific Delta2-Tub, suggesting decreased microtubule dynamics. In contrast, in the hippocampus Tyr/Glu-Tub and Delta2-Tub were increased, indicative of enhanced microtubule dynamics. A similar pattern to those seen in the hippocampus, but of higher magnitude, was observed in the amygdala where an important increase of Tyr/Glu-Tub accompanied by a decrease of the stable form Acet-Tub was observed. These findings were paralleled by decreased hippocampal spinophilin (dendritic spines marker), increased synaptophysin (pre-synaptic marker) and spinophilin in the PFC and amygdala and increased PSD-95 (post-synaptic marker) in the amygdala, all consistent with synaptic remodelling phenomena.

Taken together, these data shown that chronic agomelatine induces a differential modulation of microtubule dynamics and synaptic markers in the rat hippocampus, PFC and amygdala. These findings may have a particular relevance considering the fundamental role of these three brain areas in depression.

Identification of a novel cell type-specific intronic enhancer of macrophage migration inhibitory factor (MIF) and its regulation by mithramycin

The aim of this study was to determine the genetic regulation of macrophage migration inhibitory factor (MIF). DNase I hypersensitivity was used to identify potential hypersensitive sites (HS) across the MIF gene locus. Reporter gene assays were performed in different human cell lines with constructs containing the native or mutated HS element. Following phylogenetic and transcription factor binding profiling, electrophoretic mobility shift assay (EMSA) and RNA interference were performed and the effects of incubation with mithramycin, an antibiotic that binds GC boxes, were also studied. An HS centred on the first intron of MIF was identified. The HS acted as an enhancer in human T lymphoblasts (CEMC7A), human embryonic kidney cells (HEK293T) and human monocytic cells (THP-1), but not in a fibroblast-like synoviocyte (FLS) cell line (SW982) or cultured FLS derived from rheumatoid arthritis (RA) patients. Two cis-elements within the first intron were found to be responsible for the enhancer activity. Mutation of the consensus Sp1 GC box on each cis-element abrogated enhancer activity and EMSA indicated Sp1 binding to one of the cis-elements contained in the intron. SiRNA knock-down of Sp1 alone or Sp1 and Sp3 together was incomplete and did not alter the enhancer activity. Mithramycin inhibited expression of MIF in CEMC7A cells. This effect was specific to the intronic enhancer and was not seen on the MIF promoter. These results identify a novel, cell type-specific enhancer of MIF. The enhancer appears to be driven by Sp1 or related Sp family members and is highly sensitive to inhibition via mithramycin.

Partnerships for better oral health

Improving oral health in populations who do not easily access the private dental office or the available community care site is a challenge to dental hygienists and others concerned with the health and well-being of all. Partnerships for improved oral health have been part of the community health efforts for many years and in many countries. With the knowledge, skills, and resources that are held by specific groups and organisations combined into a larger entity of a partnership or coalition, greater impact on oral health issue may be possible. Agencies and individuals interested in making improvements in oral health status in any particular target group may begin a process of working with others who have an interest in improving the health and well being of that target group. In a world that is increasingly synergistic and mutually dependent, improvements in oral health can be advanced by considering the elements of successful coalition building and forming partnerships with multiple organisations and individuals.

Expression of multidrug-resistance P-glycoprotein (MDR1) in human brain tumors

Multidrug resistance (MDR) is associated with the expression of P-glycoprotein (P-gp), an ATP-dependent transporter which expels anti-cancer drugs from cells. In the present study, MDR1 P-gp was immunodetected by Western blot analysis in 60 human brain tumors, including meningiomas, schwannomas, low-grade gliomas (astrocytomas, pilocytic astrocytomas) and high-grade gliomas (anaplastic astrocytomas, glioblastomas and anaplastic oligodendrogliomas). Most samples from primary tumors expressed P-gp at the same levels as normal brain tissue except for schwannomas, in which levels were reduced by 65%, and meningiomas, in which levels were more than 10-fold higher in 7 of 10 samples. P-gp levels were 70% and 95% lower in brain metastases from melanomas and lung adenocarcinomas, respectively, than in normal brain tissue. These results indicate that the majority of primary brain tumors express MDR1 P-gp and that its high expression levels in meningiomas may be a marker for this type of brain tumor.

Better oral health for infants and toddlers: a community based program

Effective partnerships between health professional educational institutions and social service community programs can result in improved health outcomes for the people of the community being served. Such partnerships also may contribute considerably to student maturation into compassionate providers who have an appreciation for how an individual's health and quality of life may be affected by societal factors. A dental hygiene program at a private university and an Early Head Start Program joined in partnership to develop, and implement successfully, a project that was highly productive and of reciprocal benefit. With a focus on infant oral care in general, and early childhood caries in particular, dental hygiene students were able to provide much needed oral health services to 45 families with children enrolled in the Early Head Start Program, at multiple rural locations in Maine. In addition to meeting the needs of the Early Head Start Program, the project created a foundation for student exchange on the issues of dental caries in very young children, and the complexity of the factors contributing to them. Professional dental hygienists may choose to adopt all or portions of this innovative project when planning for the delivery of dental hygiene care to specialized populations in community-based settings.

Dental hygiene public health supervision: changes in Maine law

The author analyzed data from a set of reports submitted to the Maine Board of Dental Examiners by dental hygienists practicing under a new supervision category entitled "Public Health Supervision" enacted in Maine in 1995. The data set included information on public health dental hygiene applicants and projects reported between May 1995 and November 1998. With mounting interest from dental hygienists seeking to serve the population with limited access to preventive dental care, the regulatory board created a public health dental hygiene supervision category in the Maine regulations. The analysis revealed that dental hygienists are seeking and receiving the public health supervision endorsement. Sixty percent of the public health projects were implemented by dental hygienists in public service agencies. Those who addressed a need in their own communities without the benefit of a public health organization accounted for 40% of the applications. Examples of projects are described. The report serves as a summary of three years of data from which to assess future trends.

Matrix proteinase inhibition by AE-941, a multifunctional antiangiogenic compound

BACKGROUND

Matrix metalloproteinases (MMPs) play an important role in tissue remodeling under normal physiological and pathological conditions and are thus attractive targets for both diagnostic and therapeutic purposes. Here, we examined the effect of AE-941, an orally bioavailable standardized extract made of cartilage that shows significant antiangiogenic and antimetastatic properties in vivo, on the activity of various members of the MMP family.

MATERIALS AND METHODS

The effect of AE-941 on the activity of MMPs was assessed by fluorimetric assays and by substrate gel zymography.

RESULTS

AE-941 markedly inhibits the gelatinolytic activity of MMP-2 and to a lesser extent those of MMP-1, MMP-7, MMP-9 and MMP-13. AE-941 also inhibited the elastinolytic activities of MMP-2 and MMP-9 as well as MMP-12 (metalloelastase), porcine pancreatic elastase (PPE), and human leukocyte elastase (HLE). Western blot analysis revealed the presence within AE-941 of immunoreactive TIMP-like proteins, suggesting that these proteins may be at least partly responsible for the observed MMP inhibition.

CONCLUSIONS

Taken together, these results demonstrate that AE-941 contains TIMP-like proteins that could be responsible for the specific inhibition of MMPs. Given the recent studies suggesting the presence within this compound of specific inhibitor(s) of endothelial cell proliferation, AE-941 appears as a pleotropic agent able to interfere with several biochemical steps leading to angiogenesis and to other physiopathological conditions. Since AE-941 is currently under Phase III clinical investigations, these findings are also of considerable importance for our understanding of its anticancer properties.

Expression of matrix metalloproteinases and their inhibitors in human brain tumors

Sixty human brain tumors, classified according to the New World Health Organization (WHO) classification including, grade I schwannomas, meningiomas and pilocytic astrocytomas, grade II astrocytomas, grade III anaplastic astrocytomas, grade IV glioblastomas, grade III anaplastic oligodendrogliomas and grade IV glioblastomas and lung and melanoma metastases were analyzed for the expression of three matrix metalloproteinases (MMPs), two tissue inhibitors of MMPs (TIMPs) and for MMP activity. Some correlation was found between MMP expression and the degree of malignancy. Western blotting analysis revealed a more uniform pattern of distribution of MMP-2 (gelatinase A) than of MMP-9 (gelatinase B) and MMP-12 (metalloelastase) among tumors. MMP-9 levels were found to be significantly higher in grade III anaplastic astrocytomas and anaplastic oligodendrogliomas than those in grade I schwannomas and meningiomas. Anaplastic astrocytomas and Grade IV glioblastomas expressed significantly higher levels MMP-12 than grade I meningiomas. All sixty tumors showed a similar pattern of activity in zymography, proMMP-9 being the major species detected. Interestingly, TIMP-1 and TIMP-2 expression levels were especially low in tumors of grade II and grade III but significantly higher in tumors of grade I, particularly in schwannomas. Taken together, these data suggest that: 1) a balance between MMPs and TIMPs has an important role to play in human brain tumors; 2) TIMP expression may be valuable markers for tumor malignancy.

Expression of matrix metalloproteinases and their inhibitors in human brain tumors

Sixty human brain tumors, classified according to the New World Health Organization (WHO) classification including, grade I schwannomas, meningiomas and pilocytic astrocytomas, grade II astrocytomas, grade III anaplastic astrocytomas, grade IV glioblastomas, grade III anaplastic oligodendrogliomas and grade IV glioblastomas and lung and melanoma metastases were analyzed for the expression of three matrix metalloproteinases (MMPs), two tissue inhibitors of MMPs (TIMPs) and for MMP activity. Some correlation was found between MMP expression and the degree of malignancy. Western blotting analysis revealed a more uniform pattern of distribution of MMP-2 (gelatinase A) than of MMP-9 (gelatinase B) and MMP-12 (metalloelastase) among tumors. MMP-9 levels were found to be significantly higher in grade III anaplastic astrocytomas and anaplastic oligodendrogliomas than those in grade I schwannomas and meningiomas. Anaplastic astrocytomas and Grade IV glioblastomas expressed significantly higher levels MMP-12 than grade I meningiomas. All sixty tumors showed a similar pattern of activity in zymography, proMMP-9 being the major species detected. Interestingly, TIMP-1 and TIMP-2 expression levels were especially low in tumors of grade II and grade III but significantly higher in tumors of grade I, particularly in schwannomas. Taken together, these data suggest that: 1) a balance between MMPs and TIMPs has an important role to play in human brain tumors; 2) TIMP expression may be valuable markers for tumor malignancy.

Identification of an immunodominant ABC transporter in methicillin-resistant Staphylococcus aureus infections

Immunoblotting sera from 26 patients with septicemia due to an epidemic strain of methicillin-resistant Staphylococcus aureus (EMRSA-15), 6 of whom died, revealed an immunodominant EMRSA-15 antigen at 61 kDa. There was a statistically significant correlate (P < 0.001) between survival and immunoglobulin G to the 61-kDa band. The antigen was identified by sequencing positive clones obtained by screening a genomic expression library of EMRSA-15 with pooled sera from patients taken after the septicemic episode. Eluted antibody reacted with the 61-kDa antigen on immunoblots. The amino terminus was obtained by searching the S. aureus NCTC 8325 and MRSA strain COL databases, and the whole protein was expressed in Escherichia coli TOP 10F'. The derived amino acid sequence showed homology with ABC transporters, with paired Walker A and Walker B motifs and 73% homology to YkpA from Bacillus subtilis. Epitope mapping of the derived amino acid sequence with sera from patients who had recovered from EMRSA-15 septicemia delineated seven epitopes. Three of these epitopes, represented by peptides 1 (KIKVYVGNYDFWYQS), 2 (TVIVVSHDRHFLYNNV), and 3 (TETFLRGFLGRMLFS), were synthesized and used to isolate human recombinant antibodies from a phage antibody display library. Recombinant antibodies against peptides 1 and 2 gave logarithmic reductions in organ colony counts, compared with control groups, in a mouse model of the infection. This study suggests the potential role of an ABC transporter as a target for immunotherapy.

Expression of matrix metalloproteinases and their inhibitors in human brain tumors

Sixty human brain tumors, including grade I meningiomas, schwannomas, and pilocytic astrocytomas, grade II astrocytomas, grade III anaplastic astrocytomas and oligodendrogliomas, and grade IV glioblastomas and lung and melanoma metastases were analyzed for expression of four matrix metalloproteinases (MMPs), two tissue inhibitors of MMPs (TIMPs), and MMP activity. No marked correlation was found between MMP expression and the degree of malignancy. Western blotting analysis revealed a more uniform pattern of distribution of MMP-2 (gelatinase A) than of MMP-9 (gelatinase B) and MMP-12 (metalloelastase) among tumors. All 60 tumors showed a similar pattern of activity in zymography, MMP-2 being the major species detected. Interestingly, TIMP-1 and TIMP-2 expression levels were low in tumors of grade III but significantly higher in tumors of grade I, particularly schwannomas. Altogether, these data suggest that: (1) the balance between MMP-2 and TIMP-2 is important in human brain tumors; and (2) TIMP expression may be a valuable marker for tumor malignancy.

Matrix metalloproteinases and their inhibitors in human pituitary tumors

OBJECTIVE

To determine the expression of matrix metalloproteinases (MMP)-1, -2, and -3 and the tissue inhibitors of metalloproteinases (TIMP)-1, -2, and -3 in 12 tissue samples from normal pituitary glands and in 28 human pituitary tumors ranging from Grade 0 to Grade IV, and to establish a correlation between the level of expression of MMPs and TIMPs and the tumor grade.

METHODS

The expression of MMPs and TIMPs was determined by Western blotting. MMP activity was detected by gelatin zymography.

RESULTS

MMPs were expressed in the majority of tumors, and their levels of expression were unrelated to tumor grade or to their invasive phenotype. Some correlation was observed between MMP activity detected by zymography and tumor grade. TIMP-2 and TIMP-3 were poorly expressed in high-grade tumors and strongly expressed in normal pituitary glands and in the majority of low-grade tumors.

CONCLUSION

No correlation could be established between the invasive potential of tumors and MMP-1, -2, and -3 expression levels. Some correlation was observed between MMP activity detected by zymography and tumor grade. A good inverse correlation was observed between TIMP-2 and TIMP-3 expression levels and tumor grade. These data suggest that monitoring the expression of TIMP-2 and TIMP-3 or gelatinolytic activity could be of prognostic value.

Inhibition of P-glycoprotein by cyclosporin A analogues and metabolites

The interaction between P-glycoprotein (P-gp) from membranes isolated from multidrug-resistant Chinese hamster ovary cells and cyclosporin A (CsA) analogues and its metabolites was characterized. Screening of these latter as chemosensitizers was performed using three different assays: (i) vinblastine uptake, (ii) photoaffinity labeling by [125I]iodoaryl azidoprazosin, and (iii) P-gp ATPase activity. Oxidation of the hydroxyl group at position I of CsA (200-096), CsG (215-834), or CsD (PSC-833) increased their inhibition of P-gp. CsA analogues (208-032, 208-183) modified at position 11 retained their ability to inhibit P-gp while analogues modified at position 2 (CsC and CsD) lost their efficiency. The inhibitions induced by metabolites of CsA were also compared to those obtained with CsG metabolites. From all the molecules tested, PSC-833 and 280-446 peptolide were the strongest inhibitors. Our results indicate that modifications of CsA analogues at position 1 and 2 are critical for their interaction with P-gp and that CsA metabolites retain a portion of the inhibitory activity of the parent drug.

Dexamethasone modulation of multidrug transporters in normal tissues

The expression of P-glycoprotein (P-gp) and canalicular multispecific organic anion transporter (cMOAT or Mrp2) was evaluated by Western blotting analysis of rat tissues isolated following daily administration (1 mg kg(-1) day(-1)) of dexamethasone over 4 days. Dexamethasone rapidly increased P-gp expression more than 4.5- and 2-fold in liver and lung, respectively, while it was decreased 40% in kidney. cMOAT expression was increased 2-fold in liver and kidney following dexamethasone treatment. The levels of both proteins returned to control values by 6 days after the conclusion of dexamethasone administration. These results indicate that dexamethasone can modulate P-gp and cMOAT expression in specific rat tissues and may have significant relevance for patients treated with dexamethasone as a single agent or in combination therapy with other drugs.

Immunodetection of a type III sodium-dependent phosphate cotransporter in tissues and OK cells

Polyclonal antibodies were raised in rabbits against a 14-amino acid portion of the gibbon ape leukemia virus human membrane receptor Glvr-1. This epitope also contained seven amino acids common to the receptor for the amphotropic murine retrovirus Ram-1. Antibody specificity and molecular size of Glvr-1/Ram-1-related proteins were assayed by Western blot. Using a standard Laemmli buffer system, under reducing conditions, a single band of approximately 85 kDa (designated p85) was immunodetected in membranes prepared from opossum kidney (OK) cells and in brain membranes from rat, rabbit and hamster. In mouse brain, p85 as well as a protein of 70-72 kDa were immunodetected. This protein was also present in several other mouse tissues. Limited proteolysis of p85 and the 70-72kDa-protein from mouse yielded similar peptide fragments, suggesting that both proteins are related. Fragments of the same molecular masses were also detected in OK cell membranes following proteolysis, showing that p85 in both models (mouse brain and OK cell) share a similar sequence. p85 is not N-glycosylated since an assay using endoglycosidase F/N-glycosidase F did not alter the electrophoretic mobility of p85. We also observed that regulation of phosphate transport by incubating OK cells without any phosphate or by PTH treatment occurs without any changes in the amount of p85. In conclusion, these data demonstrate for the first time a Western blot detection of a type III phosphate transporter using polyclonal antibodies. They also suggest that, conversely to type I and type II phosphate transporters which are localized in the kidney, this third type of transporter is ubiquitous and probably absorbs the readily available phosphate from interstitial fluid for normal cellular functions in many species and tissues, serving as a housekeeping Na+/Pi cotransport system. This is also the first report showing that p85 is not regulated in the same manner as type II phosphate transporters.

P-glycoprotein is strongly expressed in the luminal membranes of the endothelium of blood vessels in the brain

Luminal membranes of the vascular endothelium were isolated from brain, heart and lungs by modification of their density. The presence of P-glycoprotein (P-gp) was detected by Western blotting in luminal membranes from the endothelium of the three tissues. Strong enrichment in brain capillary luminal membranes, compared with brain capillaries (17-fold) and whole membranes (400-500-fold), indicates that P-gp is mainly located on the luminal side of the brain endothelium. Western blotting was also performed with antibodies directed against GLUT1, glial fibrillary acidic protein, adaptin, IP3R-3, integrins alphav and collagen IV as controls to determine whether the preparations were contaminated by other membranes. Strong enrichment of GLUT1 in brain capillary luminal membranes (9.9-fold) showed that the preparation consisted mainly of endothelial cell plasma membranes. Poor enrichment of glial fibrillary acidic protein (1.4-fold) and adaptin (2.4-fold) and a decreased level of IP3R-3, integrins alphav and collagen IV excludes the possibility of major contamination by astrocytes or internal and anti-luminal membranes. High levels of P-gp in the luminal membranes of brain capillary endothelial cells suggests that it may play an important role in limiting the access of anti-cancer drugs to the brain.

Various fructose-1,6-bisphosphatase mRNAs in mouse brain, liver, kidney and heart

The mouse fructose-1,6-bisphosphatase (FBPase) cDNA was previously cloned from testicular teratocarcinoma cultured cells (F9 cells). Using this published nucleotide sequence four primer sets were defined and used to amplify FBPase transcript from cerebral cortex, heart, kidney, liver and testis of male C57B1/6 mice. Only one primer set was efficient in all total RNA prepared from the various tissues. The restriction maps of these RNA amplification products suggested the existence of three different FBPase transcripts; this was confirmed by the nucleotide sequences of the FBPase transcripts and by the deduced amino acid sequences. These data are consistent with the existence of three different FBPase genes. This may be relevant in neurological disease in which abnormalities of brain glucose metabolism are involved.

Cyclosporin A treatment induces overexpression of P-glycoprotein in the kidney and other tissues

To see whether P-glycoprotein (PGP) expressed in renal brush-border membranes (BBM) could interact with compounds known as modulators of multidrug resistance (MDR), photoaffinity-labeling experiments were performed. A 145k-Da protein was photolabeled with [125I] iodoarylazidoprazosin, and this labeling was reduced in the presence of cyclosporin A (CsA) and PSC-833 (PSC). Interaction of CsA with PGP was further investigated by treating rats with daily subcutaneous injections of CsA (10 mg.kg-1.day-1). After this treatment, PGP expression levels were dramatically increased in renal BBM, intestine, liver, and many other tissues except the brain. This induction was a reversible process, since after cessation of CsA administration PGP levels declined to reach values similar to those of the control groups. The increase in PGP expression in the kidney was also detected in photolabeling experiments, suggesting the induction of a functional PGP. A higher dose of CsA (50 mg/kg) given as a bolus injection did not modify PGP expression] in renal BBM. These results demonstrate that CsA induces reversible overexpression of PGP in the rat. This may present significant relevance in the design of clinical trials using CsA as a chemosensitizing agent.

Molecular study of P-glycoprotein in multidrug resistance using surface plasmon resonance

P-Glycoprotein is an integral membrane protein which mediates the energy-dependent efflux of various antitumor agents from multidrug-resistant cancer cells. Surface plasmon resonance was used for the detection of P-glycoprotein after solubilization from drug-resistant and drug-sensitive Chinese hamster ovary cells and for the analysis of its interaction with cyclosporin A, a competitive inhibitor of drug efflux. Detection of P-glycoprotein relied on its binding to the monoclonal antibody C219 which was immobilized on a sensor chip. Binding of Zwittergent 3-14-solubilized P-glycoprotein to the antibody was concentration-dependent and reflected the relative abundance of P-glycoprotein in both cell lines. It was abolished when C219 was omitted or replaced by a rabbit anti-mouse IgG antibody and considerably reduced after precipitation of P-glycoprotein with wheat germ agglutinin. Preincubation of solubilized proteins with cyclosporin A increased the amount of protein bound to the antibody by approximately 30%. These results indicate that surface plasmon resonance is well suited to the detection of P-glycoprotein from biological samples and shows promise as a tool for the study of its interaction with different drugs.

P-glycoprotein of blood brain barrier: cross-reactivity of Mab C219 with a 190 kDa protein in bovine and rat isolated brain capillaries

P-glycoprotein (P-gp), an active efflux pump of antitumor drugs, is strongly expressed in endothelial cells of the blood brain barrier (BBB). Two proteins (155 and 190 kDa) were detected by Western blot analysis of beef and rat capillaries with the monoclonal antibody (MAb) C219. In order to characterize the nature of these proteins, their profile of solubilization by different detergents was established and compared with that of P-gp from the CHRC5 tumoral cell line. The 155 kDa protein (p155) of capillaries and the P-gp of CHRC5 cells were well solubilized by deoxycholate and Elugent, whereas the 190 kDa kDa protein (p190) was only solubilized by sodium dodecylsulfate (SDS). Both proteins have different patterns of extraction by Triton X-114, p155 partitioning as a membrane protein, while p190 was insoluble. Deglycosylation of capillary proteins resulted in a 27-28 kDa decrease in the apparent molecular weight of p155, similar to that observed for the P-gp of CHRC5 cells, but a decrease of only 7-8 for p190. Only p155 was immunoprecipitated by MAb C219. These results suggest that only p155 is the P-gp in BBB and that MAb C219 cross-reacts with a 190 kDa MDR-unrelated glycosylated protein. Consequently, the use of this antibody, which is frequently used to detect P-gp in tumors, could be a pitfall of immunohistochemistry screening for cancer tissues and lead to false positive in the diagnosis of MDR.