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.

Magnetic resonance imaging in prostate cancer: the value of apparent diffusion coefficients for identifying malignant nodules.

The aim of this work was to determine the potential of diffusion weighted magnetic resonance imaging (DW-MRI) for identifying prostate cancer by comparing apparent diffusion coefficients (ADCs) from malignant peripheral zone (PZ) nodules with values from the non-malignant PZ and the predominantly benign central gland (CG). 33 patients with elevated prostate specific antigen (PSA) aged 52-78 years (30 patients with biopsy proven prostate cancer) underwent endorectal MRI with T2 weighted and echo planar diffusion weighting (b = 0 mm2 s(-1), 300 mm2 s(-1), 500 mm2 s(-1) and 800 mm2 s(-1)) sequences. ADCs were measured from 30 malignant PZ nodules (identified on T2 weigting and positive biopsy; median region of interest (ROI) size 41 mm2), 33 CG regions (predominantly benign nodules; median ROI size 218 mm2) and 18 non-malignant PZ regions (ipsilateral biopsies all benign; median ROI size 54.5 mm2). ADCs were (mean+/-standard deviation (SD); mm2 s(-1)): malignant PZ nodules 1.30+/-0.30x10(-3), CG 1.46+/-0.14x10(-3) and non-malignant PZ 1.71+/-0.16x10(-3). Differences between all three groups were statistically significant (p = 0.01 malignant PZ vs CG; p = 0.0001 malignant PZ vs non-malignant PZ and p = 0.0001 CG vs non-malignant PZ). Using receiver operating characteristic curves, cut-off values of 1.39x10(-3) mm2 s(-1) differentiated malignant PZ nodules from predominantly benign CG (sensitivity 60%, specificity 76%) and of 1.6x10(-3) mm2 s(-1) identified malignant from non-malignant PZ (sensitivity 86.7%, specificity 72.2%). These results suggest that DW-MRI has the potential to increase the specificity of prostate cancer detection because ADCs are significantly lower in malignant compared with non-malignant prostate tissue.

The 1993 General Social Survey II: alcohol problems in Canada.

Rates and correlates of problems associated with the use of alcohol are reported from the 1993 General Social Survey in Canada. Approximately 1 in 11 drinkers (9.2%) reported that drinking has had an adverse effect on his or her social life, physical health, happiness, home life or marriage, work, or finances in the past year. The most commonly reported problems concerned physical health (5.1%), and financial position (4.7%). Approximately one in eight drinkers (12.9%) had driven a car within an hour after consuming two or more drinks in the previous year. Furthermore, more than two of every five respondents reported that they had experienced some problem due to other people's drinking. In a multivariate analysis, age, marital status, gender, religious attendance and employment status were the strongest predictors of problem drinking. The number of heavy drinking occasions is a stronger predictor of drinking problems than is overall level of consumption.

The 1993 General Social Survey I: alcohol use in Canada.

Rates and correlates of alcohol use are reported from the 1993 General Social Survey, a household telephone survey of 10,385 Canadians carried out by Statistics Canada. Continuing a recent trend, alcohol use has declined. The portrait of the Canadian who is most likely to drink and drink heavily is that of a young adult male who is not married, relatively well-off, and rarely or never attends religious services. In a multivariate analysis of the combined impact of sociodemographic factors on drinking and drinking levels, it was found that the frequency of religious attendance and age were the strongest predictors of current drinking. Gender was the strongest predictor of volume of alcohol consumption, while religious attendance, age, marital status and employment status were also significant predictors.

Preventing alcohol problems: survey of Canadian medical schools.

In preparation for a national conference on medical education in the prevention of alcohol problems, a survey of conference participants was conducted. Participants were undergraduate and postgraduate representatives from each Canadian medical school and representatives from 11 provincial and territorial alcohol and other drug agencies. There was agreement that physicians and medical schools have important roles in prevention and treatment of alcohol problems, with "traditional" medical roles seen as the most important. Current training is variable and was seen as inadequate, with more time devoted to treatment than prevention. To correct this situation, renewed priorities and faculty leadership are needed. Respondents felt that there should be uniform standards for assessing undergraduate students' skills in dealing with alcohol problems. Provincial alcohol and other drug agencies are underused in medical education in the prevention and treatment of alcohol problems.

Drug problems among health professionals.

Available information on patterns of alcohol and drug abuse among health professionals, as well as information on abuse versus impairment, is reviewed. Past and present attitudes and approaches to helping the alcohol- or drug-impaired health professional in Ontario are examined.

Prevalence of alcohol and other drug problems among physicians.

Extreme statements regarding the prevalence of problems with alcohol and other drugs among physicians have often been made without firm empirical support. The data that are available can be categorized as follows: license and disciplinary actions, known or registered addicts, mortality rates, hospital admissions and treatment populations, and surveys of selected groups of physicians. Because of difficulties in interpreting each type of data, it must be concluded that the prevalence of drug problems among physicians is unknown. A previously unpublished survey of Ontario physicians found that the proportion who have been treated for problems with alcohol and other drugs is not greater than that in the general population. Indeed, when alcohol and other drugs are considered together, physicians may not be unusually likely to have such problems.

Alcohol and drug problems in ontario physicians: characteristics of the physician sample.

Thirty-six Ontario physicians who entered a treatment process for alcohol and drug problems were systematically assessed prior to treatment. The demographic and medical practice characteristics of this sample are delineated and, where possible, are compared to those of all Ontario physicians. Physicians with alcohol and drug problems were both similar to and different from all Ontario physicians. Further study is needed to explore the similarities and differences between the two groups, with a view to improving treatment, prevention and professional goverance.

Rhythms and responses.

Rhythms are fundamental to behavior, but the control mechanism for timed responses is not known. Many theorists have assumed that there is a central clock coordinating behavior in all sensory modalities and response modes. We tested this hypothesis using a rhythmic tapping task in which university undergraduates first attempted to synchronize responses with brief auditory, tactile, or visual stimuli and then continued to tap at the same rate on their own. Performance was most variable with visual stimuli and least variable with auditory stimuli. The detailed results suggest that performances are not based on a common clock, but, rather, different strategies are employed when the task is presented in different modalities. We reject the hypothesis of a single timing mechanism as controlling behavior and, in doing so, question the validity of information processing models that are formulated without regard to temporal relations among their conjectured processes.

Properties of adenoviral DNA bound to the nuclear matrix.

The association of adenoviral DNA with the high salt (2 M NaCl) resistant nuclear fraction, termed the nuclear matrix, has been investigated in HeLa cells at different times after infection with adenovirus type 5. When nuclear matrices were prepared in the absence of exogenously added nucleases, Ad5 DNA was quantitively associated with the matrix throughout the infection period (0-24 h). Moreover, early in infection (0-10 h) Ad5 DNA was severalfold enriched in DNase I digested nuclear matrices (8-15% of total nuclear DNA) compared to the high salt soluble chromatin fraction (85-90% of total nuclear DNA). At later times after infection, progressively more Ad5 DNA appeared in the chromatin fraction until, at 24 h, the nuclear matrix was strikingly depleted in Ad5 DNA. A large proportion of the Ad5 DNA in nuclear matrices prepared early in infection, e.g., 4 h, was full length in size. At later times (12-24 h) most of the viral DNA was fragmented to a size equivalent to total matrix DNA (100-1000 base pairs). The apparent switch of the matrix-associated viral DNA from a relatively DNase I resistant to sensitive state was initiated approximately at the time when viral DNA replication began (12 h). Since no discrete portion of the Ad5 genome was significantly enriched at the sites of attachment to the nuclear matrix throughout the infection period, the switch in DNase I sensitivity is not mediated by a change in DNA sequence attachment to the matrix.(ABSTRACT TRUNCATED AT 250 WORDS)

Tn9 and IS1 inserts in a ribosomal ribonucleic acid operon of Escherichia coli are incompletely polar.

Transcription is known to be coupled to translation in many or all bacterial operons which code for proteins. In these operons, nonsense codons which prevent normal translation often result in premature termination of transcription (polarity). However, efficient transcription of ribosomal ribonucleic acid operons (rrn operons) occurs, although rrn transcripts are not translated. It therefore seemed possible that insertion sequences and transposable elements which are polar in protein-coding operons might not be polar in rrn operons. Previously, it has been shown (E. A. Morgan, Cell 21:257-265, 1980) that Tn10 is incompletely polar in the rrnX operon. Here we show that the transposon Tn9 and the insertion sequence IS1 also incompletely polar in rrnX. In normal cells expression of sequences distal to the insertions can be detected by genetic methods. In ultraviolet-irradiated cells expression of distal sequences is about 80% of that observed in uninterrupted rrnX operons. These observations provide evidence that ribonucleic acid polymerase molecules beginning at rrnX promoters can read through Tn9 and IS1 and that, at least in ultraviolet-irradiated cells, read-through is very efficient.

Cocaine self-administration in monkeys by chewing and smoking.

Two rhesus monkeys self-administered cocaine hydrochloride in a gum base vehicle on a fixed ratio 10 schedule with performance characterized by frequent pauses and increased intertrial interval responding. Three other monkeys self-administered cocaine base in lettuce cigarette vehicles in smoking performance marked by shortened puff durations. Urinary benzoyl ecgnoine levels correlated with amount of cocaine chewed or smoked. Monkeys did not prefer cocaine gum in choice tests with plain or procaine gum, but did significantly prefer cocaine cigarettes to plain cigarettes. These preliminary results emphasize the importance of route of administration in determining reinforcement efficacy of human coca use and suggest animal models for their further experimental analysis.

The effects of hallucinogens on blind monkeys.

Two blind monkeys were studied with an observational profile that was previously shown to distinguish the effects of hallucinogens from those of other classes of drugs. Lysergic acid diethylamide and dimethyltryptamine could be distinguished from saline, chlorpromazine, d-amphetamine sulfate, and bromo-lysergic acid diethylamide by the increased frequency of spasms, stereotypy, bump, and tracking. The hallucinogens also produced dramatic increases in exploration and related behaviors normally seen only in response to real visual or auditory stimuli. These behaviors are discussed in terms of their similarity to behaviors observed with sighted monkeys in light and dark environments.

Observational determination of dose-response curves in hallucinogen-treated monkeys.

An objective behavioral profile that was previously shown to distinguish the effects of hallucinogens from those of other classes of drugs was used here to further study hallucinogenic behaviors. Saline, d-amphetamine sulfate and five doses of dimethyltryptamine (DMT) were administered to solitary adolescent rhesus monkeys in a totally dark environment and their behavior was observed via infrared monitors, videotaped, and scored in a number of categories. Scores in the following categories systematically increased with ascending doses of DMT; exploration, locomotion, stereotypy, spasm, tracking and duration of inappropriate behavior. In addition, some behaviors sensitive to hallucinogens occurred with greater frequency in the dark than in a previous study conducted in the light. Behaviors such as tracking and fear grimaces, usually associated with specific stimuli, emerged in the absence of such stimuli in the dark. These results suggested hallucinogen-induced changes in perceptual-motor systems, if not hallucinations per se.