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Biomedical subjects

G R Howe

Publications and source records attributed to G R Howe.

At least 163 records · Page 9Linked to original sources
PubMed1977

Artificial sweeteners and human bladder cancer.

A positive association between the use of artificial sweetners, particularly saccharin, and risk of bladder cancer in males has been observed in a case-control study of 480 men and 152 women in three Provinces in Canada. The risk ratio for ever versus never used is 1-6 for males (P=0-009, one-tailed test), and a significant dose-response relationship was obtained for both duration and frequency of use. The population attributable risk for males is estimated at 7%, though for diabetics, who have a similar risk ratio for artificial sweetner use as non-diabetics, the attributable risk is 33%.

British Columbia↗
PubMed1977

In vivo cholinergic stimulation of the rabbit oviductal musculature.

The in vivo activity of the rabbit oviductal musculature was evaluated in terms of constant rate perfusion resistance. Efforts to compare adrenergic and cholinergic stimulation showed that both pilocarpine and bethanechol chloride increased muscular activity 17-24% of that induced by epinephrine. The cholinergic stimulatory effect was reduced by adrenergic alpha blockade and completely abolished by cholinergic blockade or norepinephrine depletion. The data suggest that cholinergic stimulation of the tubal musculature is mediated, in part, via postganglionic adrenergic nerve fibers. It would appear that the oviductal musculature is not a primary target tissue for systemically administered autonomic agonists or antagonists.

Animals↗
PubMedDate not supplied

Cancer mortality among males in relation to exposures assessed through a job-exposure matrix.

To identify potential associations between workplace exposures and cancer mortality risks, job titles collected from 1965 to 1971 for 58,678 men (a subset of a large representative sample of the Canadian workforce) were transformed into probable chemical exposures using a job-exposure matrix developed in Montreal. Mortality follow-up was determined through computerized record linkage with the National Mortality Database in Canada for 1965-1991. Cancer mortality risk was evaluated at two levels of exposure, any and substantial, using Poisson regression controlling for age, calendar period, and social class. Among the 58,678 men, 3,160 died of cancer. Using a liberal reporting criterion, relative risk (RR) >1.0, five or more exposed cancer deaths, p < or = 0.100, several potential associations were identified, including: lung cancer and any exposure to abrasives dust (RR = 2.84), prostate cancer and any exposure to calcium carbonate (RR = 2.46), and prostate cancer and substantial exposure to metallic dust (RR = 2.13).

Adult↗
PubMedDate not supplied

The renal effects of sodium chlorite in the drinking water of C57L/J male mice.

The increasing concern over the possibility of adverse health effects due to the chlorination of drinking water has led to a search for alternative methods of disinfection. One potential alternative is chlorine dioxide which, when used, gives rise to the end product chlorite. This study investigated the potential of chlorite as a nephrotoxic agent when administered for various lengths of time (30, 90, and 180 days) in a series of concentrations (4, 20, and 100 ppm as sodium chlorite) to C57L/J male via drinking water. Examination by light and transmission electron microscopes did not reveal any evidence of renal pathologies. In addition, no evidence of significant mortality, water consumption differences, body weight change differences, kidney weight change differences, or differences in the percent kidney to body weight ratio was observed between the various levels of treatments.

Animals↗
PubMedDate not supplied

Pelvic inflammatory disease and the risk of epithelial ovarian cancer.

Infertility is a common complication of pelvic inflammatory disease (PID) and may result in decreased parity. Low parity and possibly infertility are risk factors for ovarian cancer. We therefore examined the association between ovarian cancer and history of PID in a case-control study conducted during 1989-1992 in metropolitan Toronto and nearby areas of Southern Ontario, Canada. In total, 450 histologically verified new primary epithelial ovarian cancer cases ages 35-79 years were interviewed concerning their reproduction history. Over the same period, 564 randomly selected population controls, frequently matched to the cases according to three 15-year age groups, were interviewed similarly. Continuous unconditional logistic regression methods were used for analysis. It was found that cases were more likely than controls to report having had one or more episodes of PID; adjusted for age, parity, duration of oral contraceptive use, and other factors the odds ratio (OR) was 1.53 [95% confidence interval (CI), 1.10-2.13; P = 0.012]. Higher risk was present for women with recurrent PID (OR, 1.88; 95% CI, 1.13-3.12; P = 0.014). The elevated risk associated with PID was seen particularly among women < 60 years of age at interview (OR, 1.60; 95% CI, 1.09-2.35; P = 0.016), for women of parity 0 or 1 (OR, 2.40; 95% CI, 1.39-4.15; P = 0.0017), among women who had never ever had infertility (OR, 3.74; 95% CI, 1.28-10.9; P = 0.016), and for the small number of women who reported having PID before age 20 (OR, 3.08; 95% CI, 1.17-8.13; P = 0.023).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗