Search PubMed⌕ Search

Biomedical subjects

S M Tarlo

Publications and source records attributed to S M Tarlo.

At least 19 recordsLinked to original sources
PubMed2006

An ATS/ERS report: 100 key questions and needs in occupational asthma.

The second Jack Pepys Workshop on Occupational Asthma was held in Toronto, Canada, in May 2004. The present report summarises key questions and research needs as identified by the international participants. The audiotapes from the workshop discussions were summarised by the organising chairs of the Symposium and the resulting document was circulated for input from all invited workshop participants. In total, 100 key questions and research needs were identified. Identified needs included: provision of different definitions depending on the use of data; explanations for differences in frequency studies; and better characterisation of genetic and environmental determinants of occupational asthma. The role of irritants and the pathogenesis of various forms of work-related asthma need further research, and there are also questions and research needs for diagnosis, prevention and understanding of persistence and airway remodelling. In conclusion, although advances have been made in the understanding of occupational asthma and other work-related asthma, further key issues remain that need addressing.

Asthma↗
PubMed2003

Anaphylaxis from topical bovine thrombin (Thrombostat) during haemodialysis and evaluation of sensitization among a dialysis population.

BACKGROUND: Topical bovine thrombin (TBT) is used as a topical haemostatic agent in haemodialysis (HD) units and for surgical procedures. It has caused allergic reactions during surgical procedures, but no previous cases have been reported with dialysis usage. OBJECTIVE: A case is reported of anaphylaxis due to TBT in an HD patient. This led to a determination of whether HD patients exposed to TBT develop specific IgE and IgG antibodies to TBT and an assessment of the frequency of allergic symptoms in HD patients as compared with peritoneal dialysis (PD) patients. METHODS: A cross-sectional study of 100 HD and 52 PD patients was performed using a questionnaire to determine allergic symptoms. An ELISA assay was developed to determine TBT-specific IgE and IgG serum antibodies among HD patients. HD patients without TBT exposure and age- and gender-matched blood donors served as controls. RESULTS: Allergic symptoms temporally related to dialysis reported by a questionnaire were significantly more frequent for HD patients than for PD patients: rhinoconjuctivitis 11% vs. 2%, asthma symptoms 20% vs. 6%, urticaria 23% vs. 8% (P values <0.05). Positive TBT-specific IgE and IgG antibodies were more frequent among 65 exposed HD patients (28% for IgE and 26% for IgG) than for controls (4% and 9%), P<0.05. CONCLUSIONS: Results indicate the potential for sensitization and clinical allergic responses to beef thrombin when used for haemostasis in HD and suggest that other haemostatic methods should be considered.

Adult↗
PubMed2003

Physician diagnosed asthma, respiratory symptoms, and associations with workplace tasks among radiographers in Ontario, Canada.

BACKGROUND: Medical radiation technologists (MRTs) or radiographers have potential exposure to chemicals including sensitisers and irritants such as glutaraldehyde, formaldehyde, sulphur dioxide, and acetic acid. AIMS: To determine the prevalence of asthma and work related respiratory symptoms among MRTs compared with physiotherapists, and to identify work related factors in the darkroom environment that are associated with these outcomes. METHODS: As part of a two component study, we undertook a questionnaire mail survey of the members of the professional associations of MRTs and physiotherapists in Ontario, Canada, to ascertain the prevalence of physician diagnosed asthma, and the prevalence in the past 12 months of three or more of the nine respiratory symptoms (previously validated by Venables et al to be sensitive and specific for the presence of self reported asthma). Information on exposure factors during the past 12 months, such as ventilation conditions, processor leaks, cleanup activities, and use of personal protective equipment was also collected. RESULTS: The survey response rate was 63.9% among MRTs and 63.1% among physiotherapists. Most analyses were confined to 1110 MRTs and 1523 physiotherapists who never smoked. The prevalence of new onset asthma (since starting in the profession) was greater among never smoking MRTs than physiotherapists (6.4% v 3.95%), and this differed across gender: it was 30% greater among females but fivefold greater among males. Compared with physiotherapists, the prevalence of reporting three or more respiratory symptoms, two or more work related, and three or more work related respiratory symptoms in the past 12 months was more frequent among MRTs, with odds ratios (ORs) (and 95% confidence intervals) adjusted for age, gender, and childhood asthma, of 1.9 (1.5 to 2.3), 3.7 (2.6 to 5.3), and 3.2 (2.0 to 5.0), respectively. Analyses examining latex glove use indicated that this was not likely to account for these differences. Among MRTs, respiratory symptoms were associated with a number of workplace and exposure factors likely to generate aerosol or chemical exposures such as processors not having local ventilation, adjusted OR 2.0 (1.4 to 3.0); leaking processor in which clean up was delayed, 2.4 (1.6 to 3.5); floor drain clogged, 2.0 (1.2 to 3.2); freeing a film jam, 2.9 (1.8 to 4.8); unblocking a blocked processor drain, 2.4 (1.6 to 3.7); and cleaning up processor chemical spill, 2.8 (1.9 to 4.2). These outcomes were not associated with routine tasks unlikely to generate exposures, such as working outside primary workplace, loading film into processor, routine cleaning of processors, or removing processed film. Males reported that they carried out a number of tasks potentially associated with irritant exposures more frequently than females, consistent with the marked increase in risk for new onset asthma. CONCLUSIONS: These findings suggest an increase of work related asthma and respiratory symptoms shown to denote asthma among MRTs, which is consistent with previous surveys. The mechanism is not known but appears to be linked with workplace factors and may involve a role for irritant exposures.

Adult↗
PubMed2002

Natural rubber latex allergy in the occupational setting.

Over the last decade, the prevalence of natural rubber latex (NRL) allergy has reached epidemic proportions among workers who use or who are exposed to powdered latex products. NRL-associated occupational asthma is confined largely to those exposed to powdered latex glove use or other latex aerosols. The most frequent presenting symptom of NRL allergy is contact urticaria; inhalation may cause symptoms of allergic rhinitis and asthma. Skin prick testing is the most accurate tool for diagnosis of NRL allergy. The cornerstone of management is cessation of exposure; substitution with non-NRL or nonpowdered NRL gloves results in predictable rapid disappearance of latex aeroallergen.

Asthma↗
PubMed2002

Changes in rates and severity of compensation claims for asthma due to diisocyanates: a possible effect of medical surveillance measures.

OBJECTIVES: A medical surveillance programme was introduced into Ontario for workers exposed to diisocyanates in 1983, but no mandated surveillance programme is in effect in this province for other occupational respiratory sensitisers. This study assesses changes in incidence and severity of compensated claims for occupational asthma (OA) due to diisocyanates compared with other causes, which have occurred since the introduction of this surveillance programme. METHODS: New claims for OA compensated by the Ontario Workers' Compensation Board (WCB) between 1980 and 1993 were retrospectively reviewed. Linkage was made between these data and an Ontario Ministry of Health database to assess hospital admissions for asthma from the date of onset of OA until the end of 1996. RESULTS: Numbers of claims for OA induced by diisocyanates ranged from 9-15/year in 1980-83, increased up to 55-58 claims/year in 1988-90, then fell to 19-20 claims/year by 1992-93. By contrast yearly numbers of claims for OA due to other causes increased up to 1985-87 then remained relatively stable. Duration of symptoms for OA induced by diisocyanates was shorter than for other claims and there were fewer hospital admissions among those with OA induced by diisocyanates than among those with OA induced by other causes. Occupational asthma from all causes was diagnosed earlier in claims for 1987-93 compared with 1980-86, and indicators of severity of asthma were also milder in accepted claims during 1987-93 than in earlier claims. CONCLUSIONS: Although engineering and industrial hygiene measures may have contributed to these changes, our findings are also consistent with a beneficial contribution from the medical surveillance programme for workers exposed to diisocyanates.

Adult↗
PubMed2001

Natural rubber latex-related occupational asthma: association with interventions and glove changes over time.

BACKGROUND: Exposure to natural rubber latex (NRL) has been recognized as a cause of occupational asthma (OA), especially among health care workers (HCWs) associated with use of gloves. Little or no population-based data are available which chart the changes over time in the number of cases of OA as this problem was increasingly recognized and then interventions instituted. METHODS: We obtained the numbers of allowed asthma claims with exposure to latex by year in the province of Ontario, Canada from the Ontario Workplace Safety and Insurance Board; details of the cases from the largest teaching hospital were reviewed. Interventions included: (1) in 1996, the Board recommended in its focus for accommodation of sensitized workers, the reduction of aerosols of latex proteins and that hospital facilities use powder-free, low-protein or nonlatex gloves; and (2) hospitals instituted latex policies and glove changes at various dates. For example, at the largest teaching hospital, interventions included education and voluntary medical surveillance in 1994; substitution of low protein, "powder-free" NRL gloves for non-sterile powdered gloves in 1995; and replacement of powdered sterile NRL gloves by lower protein, "powder-free" NRL gloves in 1997. RESULTS: Through 1999, there were 60 allowed claims for asthma in Ontario with exposure to latex; of these 49 (82%) were among HCWs. The number of claims among HCWs changed from 0 to 2 per year up to 1990; increased to 7 to 11 per year between 1991-1994; and declined to 3 per year in 1995-1996 and 1 to 2 per year in 1997-1999. Of the ten institutions having two or more OA latex claims, all claims occurred in 1996 or earlier at 8 (80%). At the largest hospital, there were five accepted claims with year of diagnosis in 1993 (1 case), 1994 (3 cases), and 1995 (1 case). CONCLUSIONS: These findings suggest that, despite the effect of increasing recognition, the introduction of gloves with reduced powder and/or protein, as well as other interventions have been associated temporally with declines in the number of cases of latex OA.

Adult↗
PubMed2001

Psychological features of subjects with idiopathic environmental intolerance.

OBJECTIVES: Idiopathic environmental intolerance (IEI) is associated with unexplained symptoms attributed to non-noxious levels of environmental substances. Clinically, some of the symptoms of IEI overlap with those of panic disorder (PD). We have recently reported a link between IEI and panic responses to a single inhalation of 35% carbon dioxide (CO(2)), a reliable panic induction challenge. This study assessed depression, stress, anxiety, and agoraphobic symptoms among IEI subjects from our previous study versus healthy controls. METHODS: Thirty-six IEI and 37 control subjects with no preexisting psychiatric history were compared on self-report psychological questionnaires. RESULTS: IEI subjects scored significantly higher than controls on the Agoraphobic Cognitions Questionnaire (ACQ), Depression Anxiety Stress Scales (DASS), and Mobility Inventory for Agoraphobia (MI) (Student's t, P<.05). CONCLUSIONS: IEI subjects represent a group with morbidity significantly higher than a control population but less than what would be expected for a clinical psychiatric population.

Adult↗
PubMed2001

The role of symptomatic colds in asthma exacerbations: Influence of outdoor allergens and air pollutants.

BACKGROUND: Both air pollutants and respiratory viral infections have been recognized to be important triggers of asthma exacerbations, but the possible interaction of these has not been assessed in an epidemiologic study. OBJECTIVE: In this study, we aimed to assess the possible associations of symptomatic colds with outdoor allergens and air pollutants in exacerbating asthma. METHODS: A total of 57 adults and children with asthma participated in a 1-year study in Vancouver, British Columbia. Diary cards recording symptoms of asthma and colds, medication usage, and peak expiratory flow rates were completed twice daily. Outdoor air pollutant levels and levels of pollen and fungal spores were measured. Levels were examined for associations with exacerbations of asthma with symptoms of a cold, as compared with asthma exacerbations with no cold symptoms and colds in the absence of asthma exacerbations. RESULTS: Of 130 asthma exacerbations, 47% were associated with cold symptoms (accounting for 44% of episodes of colds). Asthma exacerbations with colds were associated with higher levels of sulfur dioxide, and nitric oxide during March to November in comparison with asthma exacerbations without cold symptoms (P <.018). Cold-symptom days overall were more common in winter and were significantly associated with lower temperatures, lower ozone levels, and higher sulfur dioxide, nitrogen dioxide, nitrogen oxide (NO and NO(x)), and carbon monoxide levels. CONCLUSIONS: Asthma exacerbations are commonly associated with cold symptoms. These episodes are associated with higher levels of sulfur dioxide and nitrogen oxides from March to November in comparison with asthma exacerbations without cold symptoms.

Adolescent↗
PubMed2001

Outcomes of a natural rubber latex control program in an Ontario teaching hospital.

BACKGROUND: Allergy to natural rubber latex (NRL) has been frequently reported in health care workers. However, there is little published evidence of the outcome of hospital intervention programs to reduce exposure and detect cases of sensitization early. OBJECTIVE: This study assesses the effects of intervention to reduce NRL allergy in an Ontario teaching hospital with approximately 8000 employees. METHODS: A retrospective review assessed annual numbers of employees visiting the occupational health clinic, allergy clinic, or both for manifestations of NRL allergy compared with the timing of introduction of intervention strategies, such as worker education, voluntary medical surveillance, and hospital conversion to low-protein, powder-free NRL gloves. RESULTS: The number of workers identified with NRL allergy rose annually, from 1 in 1988 to 6 in 1993. When worker education and voluntary medical surveillance were introduced in 1994, a further 25 workers were identified. Nonsterile gloves were changed to low-protein, powder-free NRL gloves in 1995: Diagnoses fell to 8 workers that year, and 2 of the 3 nurses who had been off work because of asthma-anaphylaxis were able to return to work with personal avoidance of NRL products. With a change to lower protein, powder-free NRL sterile gloves in 1997, allergy diagnoses fell to 3, and only 1 new case was identified subsequently up to May 1999. No increased glove costs were incurred as a result of consolidated glove purchases. CONCLUSIONS: This program to reduce NRL allergy in employees was effectively achieved without additional glove costs while reducing expenses from time off work and workers' compensation claims.

Gloves, Protective↗
PubMed2001

Natural rubber latex allergy and asthma.

Allergic responses to natural rubber latex (NRL) continue to be reported. In adults, the major exposure is in the occupational setting, especially in relation to NRL glove use by health care workers. Issues addressed over the past year include improving diagnostic methods for NRL allergy and characterization of NRL allergens relevant to various exposure groups and evaluating strategies for prevention and early detection of NRL allergy. Assessment of in vitro tests show good intertest correlation but lower sensitivity compared with skin test responses. NRL allergens have been further characterized as reported in the past year. Development of recombinant Hev b 3, a major NRL allergen relevant to children with spina bifida, enhances the likelihood for improved diagnostic reagents. Preliminary reports of primary preventive strategies suggest that avoidance of high-protein, powdered gloves in health care facilities can be cost-effective and is associated with a decline in sensitized workers.

Allergens↗
PubMed2001

Marked tachypnea in siblings with chronic beryllium disease due to copper-beryllium alloy.

Two biological sisters working at the same factory for > 9 years developed chronic beryllium disease (CBD) from a copper-beryllium alloy. Both had marked tachypnea (36 breaths/min and 45 breaths/min at rest, respectively), persisting over 8 years. Ventilation during exercise (assessed in one sibling) was grossly excessive (57 L/min, expected 23 L/min) with a respiratory rate of 64 breaths/min even with normal baseline routine pulmonary function tests. Blood beryllium lymphocyte transformation test and lung biopsies confirmed the diagnosis. No other cases of CBD have been reported from this plant among about 120 workers. These cases support the genetic basis for berylliosis and illustrate the marked tachypnea that may accompany this disease.

Alloys↗
PubMed2000

Carbon dioxide inhalation challenges in idiopathic environmental intolerance.

BACKGROUND: Idiopathic environmental intolerance (IEI) is associated with unexplained physical symptoms, which overlap considerably with those of panic disorder (PD). OBJECTIVE: This study tested the hypothesis that patients with symptoms to suggest IEI exhibit features of PD in response to nonnoxious environmental stimuli. METHODS: A single-blind, case-control 35% carbon dioxide inhalation challenge was conducted at a university-based occupational health unit with the use of standardized psychologic questionnaires involving 36 patients with IEI and 37 healthy control subjects. The main outcome measures included panic attack symptoms and scores on the Anxiety Sensitivity Index, a measure of panic-related anxiety. RESULTS: Patients with IEI scored significantly higher on the Anxiety Sensitivity Index than control subjects did (P <.05). Significantly more patients with IEI (71%) than control subjects (26%) fulfilled panic attack criteria after carbon dioxide (P <.001). Physiologic responses to the challenge were not significantly different between groups. CONCLUSIONS: Results suggest that, similar to patients with PD, patients with IEI display high anxiety sensitivity and in response to carbon dioxide inhalation tend to experience heightened anxiety and panic attacks.

Administration, Inhalation↗
PubMed2000

Induced sputum: comparison of postinfectious cough with allergic asthma in children.

BACKGROUND: Cough persisting after a respiratory infection is common in children and is often managed as asthma. However, little is known about the pathophysiologic mechanisms of such cough and how it compares with asthma. OBJECTIVE: We used the technique of induced sputum to examine the inflammatory index values associated with persistent cough or allergic asthma in children. We hypothesized that the sputum from children with persistent postinfectious cough would differ from that of children with allergic asthma in that the former would lack eosinophils compared with the latter. STUDY DESIGN: Sputum production was induced with hypertonic saline solution in 34 children: 12 with cough persisting for 1 month or more after an apparent respiratory tract infection, not treated with corticosteroid; 11 with untreated atopic asthma, not using inhaled corticosteroid; and 11 with treated atopic asthma using inhaled corticosteroid. RESULTS: The percentage of eosinophils in the sputum of children with cough was significantly lower than in the sputum of children with untreated allergic asthma (median 0.5% vs 14.5%, P <.0001). Similarly, the percentage of eosinophils in the sputum of children with asthma treated with inhaled steroids was significantly lower compared with untreated asthmatic children (1.5% vs 14.5%, P <.0001). The peripheral blood eosinophils, serum eosinophil cationic protein, and nasal percent eosinophils of the patients with cough were also significantly lower than those from patients with untreated asthma. Methacholine challenge in 6 of the 11 cough patients tested showed mild-to-moderate hyperresponsiveness, whereas the other 5 had a negative methacholine challenge. CONCLUSIONS: Children with persistent postinfectious cough do not have airway eosinophilia typical of untreated asthma. Despite the absence of eosinophilic inflammation, some of the patients with chronic cough had reactive airways. These results suggest that postinfectious cough in children has different pathophysiologic features than allergic asthma and probably represents a different disease.

Asthma↗
PubMed2000

Important issues in occupational asthma.

Although there has been a dramatic increase in awareness about the contributions of the work environment to asthma, many aspects of this illness remain to be explored in further detail. This article focuses on issues that need to be better understood. Data are reported that describe newly recognized agents in the workplace that have been shown in a sophisticated manner to induce asthma. In addition, data that further describe the mechanisms of occupational asthma and information regarding the management of occupational asthma are given. Important problems yet to be resolved include whether those who develop occupational asthma from different agents are likely to have different outcomes, whether screening is likely to have a significant effect on the outcome (and, if so, what is the best approach to screening), and identification of a clear definition of the role of immunologic-mediated parameters as they relate to the initiation of asthma attributable to low molecular weight agents and patient outcome. There is little information about "safe" levels of exposure that protect all workers. Data (such as underlying specific immunologic or genetic markers) are lacking that might aid in predicting which workers are likely to be sensitized by low molecular weight agents. This abbreviated list of unresolved issues makes the study of occupational asthma a fertile field for research.

Air Pollutants, Occupational↗
PubMed2000

Recent advances in occupational asthma.

In the past year, many advances were made in occupational asthma (OA). As in previous years, several new causes of OA were described and the prevalences of some causes of OA were studied. Animal studies suggested possible mechanisms for the induction of sensitization to low-molecular-weight chemicals, and a study in humans indicated the ability of diisocyanates to bind with lung epithelial cells and stimulate mononuclear cells in sensitized patients with OA. New diagnostic and research methods, such as induced-sputum assessment and measurement of exhaled nitric oxide, were evaluated. The effectiveness of protective respiratory devices in patients with OA was shown to be suboptimal (although these devices are necessary in some cases), and the need to prevent OA by reducing or eliminating exposures remains paramount.

Animals↗