Bovine mastitis in Ontario due to Mycoplasma agalactiae subsp. bovis.
Bovine mastitis caused by Mycoplasma agalactiae subsp. bovis was first diagnosed in 16 of 55 cows in an Ontario herd in Feburary 1972. A total of 182 of 598 (30.4%) cows from 33 of 64 (51.5%) farms in widely separated areas of the province were culturally positive. Herd incidence varied from 15 to 40% with one closed herd having an incidence of 61%. Four herds were investigated culturally and serologically by the growth inhibition test for 15 months. In the acute phase the organism was present in the milk in extremely high numbers and could still be isolated from a few cows after eight to 12 months. The sera from 89.5% of the animals with clinical mycoplasma mastitis produced a zone of surface "film" and/or colony inhibition and some cows remained positive for six to 12 months. The disease was experimentally reproduced with a pure culture of the organism isolated from the milk of a cow from one of the herds. (+info)
Patterns of local and tourist use of an emergency department.
Illness patterns of local and tourist patients in an emergency department of a medium-sized Ontario city with a single hospital were compared. Frequencies of specific and broad categories of ailments and rates of admission to the hospital were similar in the two groups. However, non-Canadian tourists were admitted to hospital at a much lower rate than Canadian tourists. Rates of visits to the emergency department within certain age categories were remarkably similar, as were rates within the sexes. It is concluded that, in view of the striking similarity in the illness pattern of a group of patients not professionally referred to the hospital and that of local patients, who have potential contact with a more extensive medical network, public attitudes, rather than availability of health professionals, determine the pattern of illness observed in an emergency department. (+info)
Natural history of dysplasia of the uterine cervix.
BACKGROUND: A historical cohort of Toronto (Ontario, Canada) women whose Pap smear histories were recorded at a major cytopathology laboratory provided the opportunity to study progression and regression of cervical dysplasia in an era (1962-1980) during which cervical squamous lesions were managed conservatively. METHODS: Actuarial and Cox's survival analyses were used to estimate the rates and relative risks of progression and regression of mild (cervical intraepithelial neoplasia 1 [CIN1]) and moderate (CIN2) dysplasias. In addition, more than 17,000 women with a history of Pap smears between 1970 and 1980 inclusive and who were diagnosed as having mild, moderate, or severe dysplasia were linked to the Ontario Cancer Registry for the outcome of any subsequent cervical cancers occurring through 1989. RESULTS: Both mild and moderate dysplasias were more likely to regress than to progress. The risk of progression from mild to severe dysplasia or worse was only 1% per year, but the risk of progression from moderate dysplasia was 16% within 2 years and 25% within 5 years. Most of the excess risk of cervical cancer for severe and moderate dysplasias occurred within 2 years of the initial dysplastic smear. After 2 years, in comparison with mild dysplasia, the relative risks for progression from severe or moderate dysplasia to cervical cancer in situ or worse was 4.2 (95% confidence interval [CI] = 3.0-5.7) and 2.5 (95% CI = 2.2-3.0), respectively. CONCLUSION: The risk of progression for moderate dysplasia was intermediate between the risks for mild and severe dysplasia; thus, the moderate category may represent a clinically useful distinction. The majority of untreated mild dysplasias were recorded as regressing to yield a normal smear within 2 years. (+info)
Antimicrobial drug use and related management practices among Ontario swine producers.
A mail survey of swine producers in Ontario was undertaken during 1991 to describe the types, frequency, and motives for antimicrobial use. Two hundred operations that marketed fewer than 350 hogs per year, and 800 that marketed more than 350 per year were sent questionnaires, 63% of which were completed and returned. Most operations (86%) added antimicrobials to starter (weanling pig) rations, while fewer (29%) added these drugs to finisher pig rations. The most commonly used antimicrobials were tylosin, carbadox, and furazolidone in weanling pigs, and tylosin, lincomycin, and tetracycline in finishers. Water medication of grower-finisher pigs was practised on 25% of farms; 80% of farms had injected at least some grower-finisher pigs with antimicrobials in the 12 mo preceding the survey. Approximately 20% of operations that added antimicrobials to finisher rations did so for growth promotion purposes only, while others used them for disease treatment, prevention, control, or a combination of reasons. Among those not using antimicrobials in finisher rations, 83% did not believe they were necessary and 37% were concerned about the potential for residues in marketed hogs. (+info)
Relationships between environmental organochlorine contaminant residues, plasma corticosterone concentrations, and intermediary metabolic enzyme activities in Great Lakes herring gull embryos.
Experiments were conducted to survey and detect differences in plasma corticosterone concentrations and intermediary metabolic enzyme activities in herring gull (Larus argentatus) embryos environmentally exposed to organochlorine contaminants in ovo. Unincubated fertile herring gull eggs were collected from an Atlantic coast control site and various Great Lakes sites in 1997 and artificially incubated in the laboratory. Liver and/or kidney tissues from approximately half of the late-stage embryos were analyzed for the activities of various intermediary metabolic enzymes known to be regulated, at least in part, by corticosteroids. Basal plasma corticosterone concentrations were determined for the remaining embryos. Yolk sacs were collected from each embryo and a subset was analyzed for organochlorine contaminants. Regression analysis of individual yolk sac organochlorine residue concentrations, or 2,3,7,8-tetrachlorodibenzo-p-dioxin equivalents (TEQs), with individual basal plasma corticosterone concentrations indicated statistically significant inverse relationships for polychlorinated dibenzo-p-dioxins/polychlorinated dibenzofurans (PCDDs/PCDFs), total polychlorinated biphenyls (PCBs), non-ortho PCBs, and TEQs. Similarly, inverse relationships were observed for the activities of two intermediary metabolic enzymes (phosphoenolpyruvate carboxykinase and malic enzyme) when regressed against PCDDs/PCDFs. Overall, these data suggest that current levels of organochlorine contamination may be affecting the hypothalamo-pituitary-adrenal axis and associated intermediary metabolic pathways in environmentally exposed herring gull embryos in the Great Lakes. (+info)
Do students' attitudes toward women change during medical school?
BACKGROUND: Medical school has historically reinforced traditional views of women. This cohort study follows implementation of a revitalized curriculum and examines students' attitudes toward women on entry into an Ontario medical school, and 3 years later. METHODS: Of the 75 students entering first year at Queen's University medical school 70 completed the initial survey in September 1994 and 54 were resurveyed in May 1997. First-year students at 2 other Ontario medical schools were also surveyed in 1994, and these 166 respondents formed a comparison group. Changes in responses to statements about sex-role stereotypes, willingness to control decision-making of female patients, and conceptualization of women as "other" or "abnormal" because they are women were examined. Responses from the comparison group were used to indicate whether the Queen's group was representative. RESULTS: Attitudinal differences between the primary group and the comparison group were not significant. After 3 years of medical education students were somewhat less accepting of sex-role stereotypes and less controlling in the doctor-patient encounter. They continued, however, to equate adults with men and to see women as "not adult" or "other." Female students began and remained somewhat more open-minded in all areas studied. INTERPRETATION: A predicted trend toward conservatism was not seen as students became older, more aware and closer to completion of medical training, although they continued to equate adults with male and to see women as "other." Findings may validate new curricular approaches and increased attention to gender issues in the academic environment. (+info)
Why do patients seek family physicians' services for cold symptoms?
OBJECTIVE: To examine the frequency of presentation to family physicians' offices for cold symptoms, the reasons for presentation, and the duration of symptoms before presentation. DESIGN: Prospective cross-sectional survey. PARTICIPANTS: One hundred consecutive patient encounters in each of 15 family practices from January 27 to February 3, 1994, involving both academic and non-academic family physicians in the London region. Data were collected prospectively using a checklist attached to each chart. MAIN OUTCOME MEASURES: Proportion of patients presenting with cold symptoms, reasons for presentation, number of days patients had had symptoms, billing code. RESULTS: A total of 1421 checklists were analyzed, 822 from academic practices and 599 from community practices. Proportion of presentations for cold symptoms was 14.8%, but visits coded as common cold represented 5.7%. Median number of days patients waited before presentation was 7.0; older patients tended to wait longer. Many patients were worried about developing complications (51.0%) or were fed up with their symptoms (31.9%). Most patients were between the ages of 20 and 64 (44.6%), and 57.6% of all patients had developed complications requiring treatment. CONCLUSIONS: The proportion of visits coded as common cold was lower than Ontario averages. Most patients had complications rather than simple colds and had managed their symptoms on their own for a fairly long time. (+info)
Psychotropic drug use among women.
The consistent 2:1 ratio of women to men in the receipt of prescriptions for psychotropic drugs is reflected in the higher rates for women of neurotic illness, symptoms of both physical and mental discomfort, and help-seeking and drug-taking behaviour. Physicians' perceptions of the problems presented by their male and female patients influence their prescribing of these drugs. Recent statistics in Ontario indicate that greater use of physicians' services by women is an inadequate explanation of the higher rate of prescribing of psychotropic drugs to women. A longitudinal study of a large insured population in Ontario showed that almost twice the proportion of females, compared with males, received a prescription for psychotropic drugs in 1970-71 and in 1973-74, a higher proportion of females received multiple prescriptions for each drug class, and males were more likely than females to have received only one prescription in a year. (+info)