Exposure of Adult Mice to Environmental Tobacco Smoke Fails to Enhance the Immune Response to Inhaled Antigen

Epidemiologic evidence supports a role for environmental tobacco smoke (ETS) in the occurrence and severity of allergies/asthma. However, neither the precise combination of ETS and allergen exposure nor the mechanism (or mechanisms) by which these factors interact and contribute to asthma induction is known. Animal model studies have failed to establish a convincing relationship between ETS exposure and asthma induction, perhaps because of methodological inadequacies. Here, we tested the hypothesis that ETS inhalation would provoke an asthmatic response by overcoming normal airway tolerance to inhaled antigens. Our protocol combined daily ETS exposure with nose-only sensitization to ovalbumin. Three strains of mice were tested, each with a different level of susceptibility to airway hypersensitivity. Immunological responses were assessed by immunoglobulin production. Airway inflammation was assessed by bronchoalveolar lavage differentials and lung histopathology. Airway hyperresponsiveness was determined by methacholine challenge. The mice produced ovalbumin-specific antibodies following ovalbumin exposure in a strain-dependent manner. Only the A/J mice produced detectable levels of ovalbumin-specific immunoglobulin (Ig) E. Both A/J and BALB/c mice produced ovalbumin-specific IgG1 antibodies. The C57Bl/6 mice did not produce detectable levels of antibodies. The A/J mice also exhibited airway inflammation following ovalbumin exposure. Neither the C57Bl/6 nor the BALB/c mice exhibited signs of airway inflammation. Exposure to ETS failed to enhance ovalbumin-specific antibody production, airway inflammation, or hyperresponsiveness. Together these results indicate that ETS exposure accompanied by nose-only allergen sensitization fails to overcome aerosol tolerance in adult mice.     

Suicide and deliberate self-harm in Oxford University students over a 30-year period

Purpose  

To determine whether rates of suicide and self-harm in university students differ from those in other young people.     

Membrane‐based therapeutic plasma exchange (mTPE): Technical and clinical experience

Therapeutic plasma exchange (TPE) has long been utilized to manage a variety of immune‐mediated diseases. The basic principle relies on removal of circulating pathogenic substances from the bloodstream. Methods of plasma separation include centrifuge (cTPE) and membrane (mTPE). Although mTPE has existed for a few decades, recent advances in developing highly permeable filters that are compatible with currently existing dialysis machines has opened a new frontier. Published data in the area of technical and clinical experience with mTPE is lacking. We report our single center experience of 998 inpatient mTPE treatments performed in 237 patients at a large tertiary care academic center. The most common treatment indication was neurologic. We found a very low incidence of patient‐reported complications. Filter clotting without the use of anticoagulation occurred in 7.7% of treatments. Laboratory parameters that significantly changed during the course of therapy included serum potassium, platelet count, and partial thromboplastin time. We found that mTPE can be safely and efficiently performed as an alternative to cTPE, and suggest an individualized approach when prescribing this therapy.     

Poverty status of worker compensation claimants with permanent impairments

Poverty levels have proven to be pernicious in Canada, with particular groups at heightened risk of poverty. Given that people with disabilities are consistently identified as among those ‘at risk’, we seek to determine the extent to which injured workers/worker compensation claimants who had sustained bodily impairments live in poverty. Employing two poverty indicators, we describe the poverty levels of Ontario injured workers with permanent impairments at an average of 52 months post-injury. For one indicator, we describe proximity to/depth of poverty; and in bivariate and multivariate analyses, we examine the factors associated with poverty in the post-injury period. Estimated poverty rates for the injured worker sample – ranging from 17 to 26% – compare unfavourably to published estimates of poverty in the general population of working-aged Canadians/Ontarians and equate to those of Canadians/Ontarians with disabilities. Pre-injury employment characteristics and income status only partly account for post-injury poverty, pre-injury health does not. Sample members in post-injury poverty were more likely to report having sustained multiple injuries at the workplace, were less likely to have returned to employment or to have recovered pre-injury earnings, and yet contributed significantly more to post-injury household incomes than those not in post-injury poverty. We discuss the implications of the findings for worker compensation boards that adjudicate and have final authority on worker claims for compensation for harms sustained in the workplace.