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Biomedical subjects

K R Smith

Publications and source records attributed to K R Smith.

204 records · Page 12Linked to original sources
PubMedDate not supplied

Ovarian cancer mortality among immigrants in Australia and Canada.

This study examined the impact of changing environments on ovarian cancer by comparing age-standardized mortality rates of numerous immigrants groups in Australia and Canada to those in the origin countries for the period 1984-1988. Mortality rates by length of residence in Australia (0-29 and 30+ years) were also calculated. In Australia, the mortality rates for all four immigrant groups from low-risk countries and 53.8% from high-risk countries (n = 13) shifted toward the rate of the native-born Australians. In Canada, rates for 88.9% of immigrant groups from low-risk countries (n = 9) and 30.0% from high-risk countries (n = 10) converged to the rate of native-born Canadians. Among individual immigrant groups there was not a consistent pattern of convergence with length of residence in Australia. There was evidence of convergence among the long-term residents of some of the groups and in the aggregate analysis. The increased mortality among the majority of immigrant groups is consistent with the reported inverse relationship between parity and ovarian cancer and the generally lower parity of immigrant women compared to those in their home country. The period of residence and analyses suggests that long-term environmental and lifestyle factors in the new place of residence may also influence ovarian cancer mortality.

Adult↗
PubMedDate not supplied

Hydrocarbon emissions and health risks from cookstoves in developing countries.

The nonmethane hydrocarbon emissions from several types of cookstoves commonly used in developing countries were measured in a pilot study conducted in Manila, the Philippines. Four types of fuel, i.e., wood, charcoal, kerosene, and liquefied petroleum gas (LPG), were tested. Because kerosene was burned in three different types of stoves, there were six fuel/stove combinations tested. Fifty-nine nonmethane hydrocarbons were identified frequently in emissions of these cookstoves, with emission ratios to CO2 up to 5.3 x 10(-3). The emissions were quantitated with emission factors on both a mass basis (emissions/kg fuel) and a task basis (emissions/cooking task). On a task basis, combustion of biomass fuels (wood and charcoal) generally produced higher emission factors than combustion of fossil fuels (kerosene and LPG). One type of kerosene stove (wick stove), however, still generated the greatest emissions of some individual and classes of hydrocarbons, indicating that emissions were dependent on not only fuel types but also combustion devices. Some hydrocarbons, e.g., benzene, 1,3-butadiene, styrene, and xylenes, were of concern because of their carcinogenic properties. The lifetime risk from exposures to these compounds emitted from cookstoves was tentatively estimated by using a simple exposure model and published cancer potencies.

Air Pollutants↗
PubMedDate not supplied

Influence of others in motivating women to obtain breast cancer screening.

PURPOSE: The purpose of this study was to examine the importance of influence of other people in getting women to obtain breast cancer screening. DESCRIPTION OF STUDY: A descriptive study of 129 women completed the researcher-developed, Likert-type scale-Influence of Others Scale. A self-report questionnaire was used to obtain frequency of breast cancer screening behaviors (breast self-examination, clinical breast examination, and mammography). RESULTS: The Influence of Others Scale had acceptable reliability scores. Comparison of the means and t-test analyses between those who performed the recommended screening behavior with those who had not revealed that the influence of family and friends and the influence of knowing someone with breast cancer were significant for each of the three screening behaviors. Regression analyses revealed that the influence of others was highly significant to the practice of breast self-examination and less so for mammography and clinical breast examination. CLINICAL IMPLICATIONS: These findings underscore the potential importance of using specific women's social networks to reinforce breast cancer screening.

Breast Neoplasms↗
PubMedDate not supplied

The safety, tolerability, and pharmacokinetics of fosphenytoin after intramuscular and intravenous administration in neurosurgery patients.

STUDY OBJECTIVE: To evaluate the safety, tolerability, and pharmacokinetic profile of fosphenytoin, a water-soluble phenytoin prodrug, after intramuscular and intravenous administration. DESIGN: Open-label study of intramuscular administration, and double-blind, randomized study of intravenous administration. SETTING: Six and ten hospitals throughout the United States for the intramuscular and intravenous multicenter studies, respectively. PATIENTS: Neurosurgical patients who required anticonvulsant prophylaxis or treatment. INTERVENTIONS: In the intramuscular study, 118 patients received loading doses ranging from 480-1500 mg phenytoin equivalents (PE) and daily maintenance doses ranging from 130-1250 mg PE for 3-14 days. In the intravenous study, 88 patients received fosphenytoin and 28 received phenytoin sodium for 3-14 days. Mean +/- SD loading doses and maintenance doses of intravenous fosphenytoin and phenytoin were 1082 +/- 299 mg PE and 411 +/- 221 mg PE, and 1082 +/- 299 mg and 422 +/- 197 mg, respectively. Trough phenytoin concentrations were measured daily in all patients. MEASUREMENTS AND MAIN RESULTS: Intramuscular fosphenytoin was safe and well tolerated, with no irritation found for 99% of all injection site evaluations. Adverse events associated with the drug occurred in 9% of patients, commonly those typical of the parent drug. For intravenous treatment, the frequency of mild irritation at the infusion site was significantly lower in the fosphenytoin group (6%) than in the phenytoin group (25%, p < 0.05). Reductions in infusion rates were required in 17% and 36% of fosphenytoin and phenytoin recipients, respectively. No significant difference was observed relative to adverse events or seizure frequency between the groups. Trough plasma phenytoin concentrations were approximately 10 micrograms/ml or greater in patients receiving at least 3 days of intramuscular and intravenous fosphenytoin. Trough phenytoin concentrations were similar between patients receiving intravenous phenytoin and fosphenytoin on all study days. CONCLUSION: Fosphenytoin can be administered intramuscularly and intravenously in neurosurgical patients to achieve and maintain therapeutic phenytoin concentrations for up to 14 days. Both routes are safe and well tolerated. Intravenous fosphenytoin is significantly better tolerated than intravenous phenytoin sodium in this patient subset.

Adolescent↗
PubMedDate not supplied

In vitro and in vivo effects of rifampin on Staphylococcus epidermidis graft infections.

Rifampin, bound in high concentrations to prosthetic grafts, has been proposed for the treatment of vascular graft infections. The optimum antibiotic concentration and duration of treatment for infected grafts is not known. This study compared the in vitro and in vivo efficacy of varying concentrations of rifampin against three different strains of slime producing Staphylococcus epidermidis (RP62A, KC2, and KB1) bound to the knitted Dacron at high and low concentrations at 10(4) and 10(7) CFU/cm2 of prosthetic. Time kill experiments were performed at 4, 18, and 42 hr, in which each Dacron bound bacterial strain was exposed in vitro to 4X, 64X, 100X, and 1,000X minimum inhibitory concentration (MIC) of rifampin. In vitro, the Dacron bound laboratory strain RP62A was implanted subcutaneously in the backs of male Swiss-Webster mice and exposed to 4X, 100X, and 1,000X the MIC of rifampin for similar time periods. In addition, systemic vancomycin (10 mg/kg) was assessed for synergy and prevention of rifampin resistance. In vitro, all concentrations of rifampin showed near total killing (< 1 log) of all bacterial strains at low initial concentrations (10(4) CFU/cm2) but not high (10(7) CFU/cm2) to 42 hr. Importantly, resistance was shown to develop in all three strains of S. epidermidis with high initial bacterial biofilm concentrations. In vivo, rifampin concentrations between 4X MIC and 100X MIC achieved a balance between optimal killing and prevention of resistance. Systemic vancomycin slightly improved bacterial clearance but did not alter the development of rifampin resistance at high local concentrations. Caution is advised with the use of antibiotic bonded grafts because resistance may develop even with the addition of systemic antibiotics.

Animals↗