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Biomedical subjects

R Steele

Publications and source records attributed to R Steele.

At least 19 recordsLinked to original sources

Human breast carcinoma cells transfected with the gene encoding a c-myc promoter-binding protein (MBP-1) inhibits tumors in nude mice.

We have identified previously a gene from a human cervical carcinoma cell (HeLa) cDNA expression library that encodes a M(r) approximately 37,000 c-myc promoter-binding protein (MBP-1), which binds to the TATA box sequences of c-myc P2 promoter and exerts a negative regulatory function by down-regulating c-myc expression. In normal human tissues, this cloned gene showed variable expression. In this study, we have demonstrated that introduction of the MBP-1 gene into human breast carcinoma cells reduced their ability to invade through a basement membrane matrix in vitro but did not alter their growth rate. Human breast carcinoma transfected with MBP-1 cells showed a loss of anchorage-independent growth and also suppressed tumor formation in athymic nude mice. These results suggest the possible involvement of MBP-1 as a tumor suppressor gene in human breast carcinoma cells.

Animals

Effect of L-thyroxine (LT4) and D-thyroxine (DT4) on cardiac function and high-energy phosphate metabolism: a 31P NMR study.

31P NMR spectroscopy was used to monitor the cardiac energy metabolism in hypothyroid rat hearts. Differential alterations in phosphocreatine and inorganic phosphate levels were observed upon treatment of hypothyroid animals with DT4 and LT4, while both agents were equipotent in reducing cholesterol. These results show potential for NMR spectroscopy as a technique to determine therapeutic selectivity.

Adenosine Triphosphate

Endobronchial zygomycosis.

Pulmonary zygomycosis is an uncommon opportunistic fungal infection. Diabetics have a tendency to develop major airway lesions. This can lead to invasion of the airway wall and hilar vessels with infarction and severe haemoptysis. Aggressive early surgery appears to offer the best chance of recovery.

Aged

Controversies in the management of non-small cell lung cancer: the results of an expert surrogate study.

Four hundred and sixty-one doctors who treat lung cancer in Canada and the United States answered a questionnaire in which they were asked how they would wish to be managed if they developed non-small cell lung cancer (NSCLC). There was no evidence of a consensus as to preferred treatment in either of two clinical situations described. Personal treatment preferences were significantly influenced by specialist training and each discipline showed a preference for its own modality of treatment. The personal treatment preferences of American and Canadian doctors differed significantly. In the United States, the role of surgery in NSCLC with extensive mediastinal disease was controversial, whereas in Canada, the major controversy was whether any active treatment was desirable in this situation if symptoms were absent. The role of chemotherapy in the treatment of NSCLC with painful bone metastases was controversial in the United States, but the vast majority of Canadian doctors would not wish any form of chemotherapy in this situation. Respondents were also asked what treatment they usually recommended for patients with NSCLC in the two situations described. Almost all these doctors recommended for their patients exactly the same treatment which they would choose for themselves. It was concluded that the personal treatment preferences of doctors are an important factor in determining how patients with NSCLC are treated. Doctors were also asked (a) if they would be willing to participate as patient-subjects in a number of clinical trials for which they would be eligible if they developed NSCLC, and (b) if they would be willing to ask their patients to participate in the same trials. There were significant differences in the perceived acceptability of the trials studied, but in each case a higher proportion of doctors would be willing to ask their patients to participate than would be prepared to consent themselves.

Attitude of Health Personnel

Ultrasonography in the differentiation of complicated and uncomplicated acute pyelonephritis.

Differentiation of uncomplicated pyelonephritis versus complicated pyelonephritis has always been problematic. No clear physical signs or symptoms are diagnostic. To study differences between the two, we retrospectively reviewed charts of patients admitted to Charity Hospital, New Orleans, with febrile urinary tract infections. Criteria for inclusion were pyuria, positive urinary culture, and signs or symptoms of pyelonephritis. All patients underwent renal ultrasonography (US) before other diagnostic tests. US identified a potential emergency (hydronephrosis or abscess) in 11 of 98 patients (11.2%). The only significant contributing factor was the presence of diabetes mellitus, which was present in five of 11 emergent conditions and eight of 73 of the remainder (P = 0.003). US is inexpensive, easily obtainable in the emergency room, and sensitive enough to screen patients with pyelonephritis for complications. However, we believe it is mandatory in diabetics, because of the high incidence of abnormalities in this population.

Acute Disease

A descriptive survey of black nursing faculty.

This descriptive study looks at the cohort of Black nursing faculty members teaching in baccalaureate and higher degree programs from a national perspective. The researchers were interested in how Black faculty members were faring in the halls of academe.

Adult

Tips for nursing faculty entering clinical practice.

Many nurse educators perceive a need to maintain clinical competence but encounter obstacles to pursuing ongoing clinical practice. This article identified five key steps for the educator entering clinical practice; expect culture shock, identify orientation needs, find a resource person, learn the institution's formal routine, and assess and use the institution's informal network. Implementing these strategies will alleviate stress and will help faculty members to update their clinical skills and earn the respect of their practice colleagues.

Adaptation, Psychological

Risk of bladder cancer by source and type of tobacco exposure: a case-control study.

The association between tobacco use and risk of bladder cancer was investigated in a population-based case-control study conducted in Alberta and south-central Ontario, Canada, between 1979 and 1982. In all, 826 histologically-confirmed cancer cases and 792 randomly selected controls, individually matched to cases for age, sex, and area of residence, were recruited into the study. Compared to those who had never smoked cigarettes, males and females who had ever smoked cigarettes had a statistically highly significant 2-fold increase in risk of bladder cancer; for ex-smokers, the risk was intermediate between that for current smokers and never-smokers. There was a dose-dependent increase in risk of bladder cancer with total lifetime cigarette consumption, of similar magnitude for males and females. In males, risk increased with self-reported degree of inhalation in ex-smokers and in current smokers (statistically significant trend), while in females there was no association in current smokers, and a statistically significant inverse association in ex-smokers. Overall, risks of bladder cancer associated with lifetime consumption of plain and filter cigarettes were similar, and there was little evidence to suggest that switching from plain to filter cigarettes was beneficial. Neither passive smoking nor other forms of tobacco consumption (pipes, cigars, chewing tobacco, or snuff) were associated with altered risk of bladder cancer. The population attributable risk for cigarette smoking was about 47% in males and about 33% in females.

Adult

DSM-III diagnoses of patients with myofascial pain syndrome (fibrositis).

Rheumatology centers report that chronic pain patients with myofascial pain (fibrositis) are prone to psychiatric pathology. However, the distribution of DSM-III diagnoses in this population is unknown. This distribution is reported for 238 chronic pain patients with fibrositis. Statistical comparisons of men and women were also made with regard to the prevalence of each diagnosis, and the results were compared to published DSM-III diagnoses prevalence data for mixed chronic pain patients and rheumatology fibrositis patients. In our sample, women with fibrositis were equally as likely as men with fibrositis to have current depression. Within the general chronic pain population, women are more likely to have current depression. The incidence of current major depression and current and past major depression was much lower in our fibrositis sample than that reported by rheumatology programs. These results indicate that there may be psychiatric differences between chronic pain patients with and without fibrositis. Fibrositis patients in rheumatology programs may also be psychiatrically different from chronic pain program patients with fibrositis.

Adult

Clinical trials in cancer: the role of surrogate patients in defining what constitutes an ethically acceptable clinical experiment.

Doctors who treat lung cancer in Ontario were previously asked how they would wish to be managed if they developed non-small cell lung cancer and whether they would consent to participate in six clinical trials for which they might be eligible. The proportion of these expert surrogate patients who would consent to each clinical trial ranged from 11 to 64%. The results of this study were transmitted to the same group of doctors who were asked to comment on the ethical acceptability of each trial in the light of this information. The majority of physicians said that those trials to which less than 50% of expert surrogates consented should not have been opened to patients. Sixty-nine per cent of doctors thought that new trials should be evaluated in this way. We also present the results of a survey of 400 lay people in Ontario who were asked to imagine that they had lung cancer and whether they would consent to participate in two of these same clinical trials. Fifty per cent of lay people consented to a randomised trial of lobectomy versus segmentectomy in early, operable disease (LCSC-821) compared to 64% of expert surrogates, and 48% of lay people consented to a randomised trial of five different forms of chemotherapy in metastatic disease (SWOG-8241) compared to 19% of doctors. It was concluded that the lay people were unable to discern differences in the acceptability of clinical trials which were clear to experts in the field. Subsequently, respondents were told about the decisions which doctors would make in the same circumstances and asked if this information would modify their previous decisions. There is no net change in the proportion of patients consenting to the surgery trial but the proportion of people consenting to the chemotherapy trial decreased by 40%. The majority of lay people said that they would wish to have access to this type of information before consenting to participate in a clinical trial.

Attitude of Health Personnel

Immune function in patients treated with phenytoin.

Multiple immunologic side effects have been ascribed to phenytoin. Numerous reports in the literature discuss the possible cellular and humoral abnormalities that appear to be present in patients given phenytoin. The most consistent finding is a reduction in serum IgA found in up to 20% of patients. To resolve some of the conflicting studies on cellular immune status, 191 patients taking phenytoin were evaluated initially with an serum IgA determination, and then further immune studies were done on the 11% with IgA values lower than two standard deviations below the mean. Data collected included total lymphocyte counts, lymphocyte population studies, and responses to in vitro mitogen stimulation. Only 2 of 191 patients had serum IgA values less than 5 mg/dL, which is an incidence not significantly different than that in the population at large. The patients with decreased serum IgA values did not have an increased incidence of autoimmune phenomena, allergic disorders, gastrointestinal manifestations, or recurrent upper respiratory tract infections. Their cellular immune status showed no significant variations from control values. Thus it appears that routine monitoring of patients on phenytoin with serum IgA determinations is of limited value, and the immunologic side effects of phenytoin are not expressed as a cellular abnormality.

Adolescent

Dietary factors and the incidence of cancer of the urinary bladder.

A case-control study of diet and bladder cancer was conducted during 1979-1982 in Edmonton, Calgary, Toronto, and Kingston, Canada. A total of 826 histologically verified cancer cases were individually matched by age, sex, and area of residence to 792 randomly selected population controls. Subjects were interviewed concerning their histories of exposure to a number of dietary factors, including table-top artificial sweeteners, low calorie foods and drinks, beverages containing caffeine or ethanol, and certain other food items. Also, subjects provided information on their past medical, occupational, and residential histories, in addition to their exposures to tobacco and other life-style factors. For the analysis, conditional logistic regression methods were used. Under adjustment for cumulative lifetime amount of cigarette smoking, the dietary factors, with little exception, were not associated with significant alteration of risk for bladder cancer. In particular, ever regular use of artificial sweeteners did not appear to be associated with increased risk, either among men (odds ratio = 0.95, p = 0.70) or among women (odds ratio = 1.15, p = 0.53). However, daily intake of cholesterol, calculated from reported frequencies of consumption of nine relevant food items, suggested a mild increase in risk; the odds ratio estimate of trend was 1.07/100 mg average daily intake (i.e., 1.07(5.5) = 1.45 for 550 mg cholesterol per day, as might be consumed in one egg; p = 0.009). A history of diabetes mellitus of onset after age 20 years also seemed to be associated with increased risk of bladder cancer (odds ratio = 1.65, p = 0.019), but this increase did not appear to be the result of use of insulin or other medications, or use of artificial sweeteners or low calorie foods. Thus, this study tends to confirm reports of a lack of association between use of artificial sweeteners and subsequent risk of bladder cancer.

Adult

Occupational factors and the incidence of cancer of the bladder in Canada.

During 1979-82, a case-control study of occupational factors and urinary bladder cancer was conducted in Edmonton, Calgary, Toronto, and Kingston, Canada. A total of 826 histologically verified cases of cancer were individually matched by sex, age, and area of residence to 792 randomly selected population controls. Subjects were specifically asked about employment in several industries thought relevant to risk of bladder cancer. Information was also obtained on lifelong occupational history, with special attention given regarding exposures to fumes, dusts, smoke, and chemicals. In addition, subjects provided data on past medical and residential history, on intake of certain dietary items, and on exposure to tobacco and other lifestyle factors. Conditional logistic regression methods were used for the analysis. Under adjustment for cumulative lifetime cigarette consumption, it appeared that for both men and women, most of the occupational factors examined were not associated with significant alteration in risk of bladder cancer. For exposures during the period eight to 28 years before diagnosis, however, raised risk was suggested for men employed at least six months in the chemicals industry (odds ratio = 2.37, p = 0.004), in dye manufacturing or the dyeing of cloth (OR = 3.62 and 4.63, p = 0.041 and 0.035, respectively), as tailors (OR = 3.85, p = 0.015), or in jobs in which contact with diesel or traffic fumes occurred (OR = 1.69, p = 0.0008). Increased risk was also seen for men occupationally exposed to tars or asphalt (OR = 3.11, p = 0.019). This study then, at least for men, supports perhaps a few of the suspect industries as related to risk of bladder cancer.

Adult