Factors associated with the adoption of a smoking ban in Quebec households.

The home represents an important source of exposure to environmental tobacco smoke for non-smokers, including children, who live with smokers. Our goal is to identify the sociodemographic factors associated with the adoption of smoking bans in "smoker households" in Quebec. Selected associations are compared with three other Canadian provinces (Ontario, British Columbia and Nova Scotia). This is a cross-sectional study involving 2648 respondents. Logistic regression analysis is employed. Few smoker households in Quebec (21%) have a ban on smoking; the presence of a non-smoker is strongly linked to the existence of such a ban; the presence of a child under the age of 6 is less strongly associated with the adoption of a ban in Quebec than in the other provinces, and the presence of an adolescent shows no association whatsoever. In addition to the child health benefits of household smoking bans, greater emphasis should be placed on the impact that such bans can have on children's future smoking behaviour. One option from a health promotion standpoint might be to organize a campaign aimed at non-smokers who live with smokers, in order to urge them to be less tolerant of environmental tobacco smoke.

Multiple work-related accidents: tracing the role of hearing status and noise exposure.

OBJECTIVES: Our main purpose was to investigate any relationship between noise exposure levels in the workplace, degree of hearing loss (HL), and the relative risk of accident (OR of single or multiple events). METHODS: We conducted a retrospective study of 52 982 male workers aged 16-64 years with long-standing exposures to occupational noise over a 5-year period, using "hearing status" and "noise exposure" from the registry held by the Quebec National Institute of Public Health. Information on work-related accidents was obtained from the Quebec Workers' Compensation Board. Hearing threshold level measurements and noise exposures were regressed on the numbers of accidents after adjusting for age. RESULTS: Exposure to extremely noisy environments (L(eq8h) (equivalent noise level for 8 h exposure) > or =90 dBA) is associated with a higher relative risk of accident. The severity of hearing impairment (average bilateral hearing threshold levels at 3, 4 and 6 kHz) increases the relative risk of single and multiple events when threshold levels exceed 15 dB of hearing loss. The relative risk of multiple events (four or more) is approximately three times higher among severely hearing-impaired workers who are exposed to L(eq8h) > or =90 dBA. CONCLUSION: Single and multiple events are associated with high noise exposure and hearing status. This suggests that reducing noise exposure contributes to increased safety in noisy industries and prevents hearing loss. Hearing-impaired workers assigned to noisy workstations should be provided with assistive listening devices and efficient communication strategies should be implemented.

High blood cadmium levels are not associated with consumption of traditional food among the Inuit of Nunavik.

High levels of cadmium in the liver and kidneys of caribous and sea mammals of the Canadian Arctic have led to recommendations to remove such offal from the traditional diet. Blood cadmium levels have been found to be very high in samples of Inuit volunteers, hence the hypothesis that the Inuit might be exposed to cadmium through their diet. This survey of a population-based random sample of Nunavik residents (n = 518) confirms that blood cadmium of Inuit is indeed very high by comparison to published reports. Blood cadmium levels are closely associated with the current smoking status and are independent of dietary patterns among nonsmokers. Plasma omega-3 fatty acids concentrations have been used to assess the reliability of the dietary information collected by questionnaires and to test for any association of blood cadmium with the consumption of sea mammals. Blood cadmium levels are not related to the reported consumption of sea mammals. Blood cadmium levels are very high among smokers and are associated with levels of exposure to tobacco. Among nonsmoking Inuit, blood cadmium levels are comparable with those reported in nonsmokers elsewhere in the world. In reference to international standards, blood cadmium concentrations are high enough among the Inuit to warrant energetic public health interventions.

HIV-1 gp120/160 expressing cells upregulate HIV-1 LTR directed gene expression in a cell line transfected with HIV-1 LTR-reporter gene constructs.

The results described in this paper demonstrate that HIV-1 gp120 can upregulate gene expression directed by the HIV-1 LTR. Briefly, exposing responder CD4+CEM-T4 ID5 cells to stimulator CEMgp120/160 expressing cells (stably transfected with HIV-1 LTR-CAT and HIV-1 gp160, respectively) resulted in the increased synthesis of the CAT enzyme. Control non-transfected CEM-T4 cells did not induce the synthesis of CAT. In addition, when the responder cell line, U937-1C5 which also contains stably transfected HIV-1 LTR-CAT plasmid was exposed to irradiated CEM gp120/160 cells, there was no synthesis of the CAT enzyme. Neither recombinant gp120 nor gp160 were able to stimulate the synthesis of CAT in the responder cells. These results indicate that the mechanism by which gp120/160 expressed on transfected cells increase CAT synthesis in responder cells may be dependent on the manner which the protein is presented in association with accessory molecules. Moreover, recombinant soluble CD4 and anti-CD4 monoclonal antibodies inhibited CEM gp120/160 induced expression of HIV-1 LTR-directed expression in CEM-1D5 cells. Based on these results we hypothesize that HIV or its envelope protein, gp120, upon interaction with its receptor, the CD4 molecule on T helper cells, transduces a signal which translates into the upregulation of the gene expression directed by the HIV-1 LTR.

Regulated pre-employment medical examinations and their effect on the utilization of health services: the experience of 1,498 police cadets, Quebec, 1988.

Persons seeking employment in a police department must submit to a pre-induction medical screening after they have qualified on a compulsory test of physical stamina. The effect of this imposition on the utilization of health services was studied in a group of 1,498 police cadets whose use of medical and optometric services was monitored over a period of one year and compared with that of the general population of the same age and sex. Cadets have used about as much care as women of child-bearing age and were almost all exposed to physiological and radiological procedures that have no known utility in the medical surveillance of workers. It is estimated that the cost of providing the protection that is apparently sought by the regulation varies between $6,285 and $66,000 per person.

Unusually high blood cadmium associated with cigarette smoking among three subgroups of the general population, Quebec, Canada.

Blood cadmium levels were measured in 554 persons without any known professional exposure to this metal. They were grouped in three samples; one entirely of 142 Inuit, one of 212 caucasian city dwellers and one of 200 caucasian rural residents. While blood cadmium levels measured in non-smokers are comparable to those reported in published reports, those of current cigarette smokers were 10-20 times higher than non-smokers. These blood cadmium values stand in sharp contrast to what has been published so far and make the average smokers of Canadian-made cigarettes medically unfit for employment in jobs associated with potential cadmium exposure.

Blood and urinary cadmium levels in Inuit living in Kuujjuaq, Canada.

Blood and urine cadmium concentrations have been determined in a group of 85 Inuit residents of Kuujjuaq, Quebec, Canada, drawn from actively hunting households. Mean blood cadmium values are high at 39.4 nmol/l, varying between 6.6 in non-smokers and 60.3 in smokers. No association of blood cadmium with self-reported offal consumption could be found. Median urine cadmium concentrations are elevated at 2.3 mumol/mol creatinine and rise substantially with age: 0.9 in the 30-39 age group; 3.2 among the 40-59 age group; and 4.1 in the 60 and over.

[Clinical characteristics affecting the need for relining of class 1 and class 2 removable mandibular prostheses]. / Caractéristiques cliniques affectant le besoin de regarnissage des pièces de prothèses amovibles de classe 1 et 2 à la mandibule.

This study attempts to identify, from a sample of people wearing a class 1 or 2 removable prosthetic device on the lower jaw, the extent of the relining needs for these prostheses and their determining factors. Epidemiological methods were used to solve this problem. The relining needs increase with the amount of time elapsed since the prosthetic device was put in the mouth (p = 0.014). As for the other factors reviewed, i.e. class of device, type of retainers used, and occlusion, the authors have identified trends instead of real risk factors, since the impact of this study was significantly reduced due to the small number of people we were able to recruit. It was not always possible, therefore, to verify the statistical meaning of the associations observed. In clinical practice, the treatment plan should include a periodical evaluation of the relining needs. As it is now impossible to establish the approximate time when a prosthetic device may need relining, patients wearing one should be examined periodically and regularly.

Coping with low-back pain: Remaining disabilities 5 years after multidisciplinary rehabilitation.

The health status of 106 persons once affected with a chronic low back pain episode was compared to that of 115 referent subjects, category matched on sex, age, and time of episode about 5 years after their admission to a multidisciplinary treatment program in rehabilitation. The current health status of both groups was assessed with the Sickness Impact Profile (SIP). Results show that cases reported significantly more functional limitations in areas related to ambulation, body care and movements, home management activities, and employment. These limitations increased with age. The current distress of cases seemed comparable to that of patients with severely restricting diseases such as end-stage renal disease. This study underlines the duration and burden of personal suffering among workers with chronic low back pain.

Establishment and characterization of a thymic medullary epithelial cell clone.

Thymic stromal cells were cultured in conditions which select for epithelial cells. These were then transformed in vitro by contact with N-methyl-N'-nitro-N-nitrosoguanidine and cloned at limit dilution. One of the clones was characterized as being of medullary origin on the basis of its reactivity with a battery of antibodies previously shown to distinguish cortical from medullary thymic epithelial cells. The importance of this clone lies in the potential it offers to delineate how various T cell subpopulations acquire their distinct markers and function within the thymus.

Age- and sex-specific prevalence of scoliosis and the value of school screening programs.

A prevalence study of idiopathic scoliosis was conducted among 29,195 children of a community health district in the province of Quebec. The study was designed to determine whether a permanent screening program for idiopathic scoliosis was justified. The prevalence of the condition among school children aged 8 to 15 years was 42.0 per 1,000 in the screened population, 51.9 per 1,000 among girls, and 32.0 per 1,000 among boys. The positive predictive value of the bending test is estimated as 42.8 per cent for scolioses of 5 degrees or more; it is only 6.4 per cent when curves of 15 degrees or more are considered. The average cost of finding one child with a scoliosis of 5 degrees or more is $194. Mass screening for idiopathic scoliosis does not seem to be justified in the present state of knowledge of the disease.