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Biomedical subjects

J Howland

Publications and source records attributed to J Howland.

At least 37 records · Page 2Linked to original sources
PubMed1996

Insulin and secretagogues differentially regulate fluid-phase pinocytosis in insulin-secreting beta-cells.

The physiological role of the beta-cell insulin receptor is unknown. To evaluate a candidate function, the insulin regulation of fluid-phase pinocytosis was investigated in a clonal insulinoma cell line (beta TC6-F7) and, for comparison, also in Chinese hamster ovary cells transfected with the human insulin receptor (CHO-T cells). In CHO-T cells, the net rate of fluid-phase pinocytosis was rapidly increased 3-4-fold over the basal rate by 100 nM insulin, with half-maximal stimulation at 2 nM insulin, as assayed by cellular uptake of horseradish peroxidase from the medium. Wortmannin, an inhibitor of phosphatidylinositol (PI)-3-kinase, blocked insulin-stimulated pinocytosis with an IC50 of 7.5 nM without affecting the basal rate of pinocytosis. In insulin-secreting beta TC6-F7 cells, the secretagogues glucose and carbachol (at maximally effective concentrations of 15 mM and 0.5 mM respectively) augmented fluid-phase pinocytosis 1.65-fold over the basal rate. Wortmannin also inhibited secretagogue-stimulated pinocytosis in these beta-cells with an IC50 of 7 nM but did not affect the basal rate of pinocytosis measured in the absence of secretagogues. Wortmannin did not influence either basal or secretagogue-induced insulin secretion. Although these beta TC6-F7 cells have cell-surface insulin receptors, adding exogenous insulin or insulin-like growth factor 1 did not affect their rate of fluid-phase pinocytosis, either in the absence or presence of secretagogues. From these observations, we conclude that: (1) in both insulin-secreting beta-cells and in conventional, insulin-responsive CHO-T cells, a common, wortmannin-sensitive reaction, which probably involves PI-3-kinase, regulates fluid-phase pinocytosis; (2) the insulin-receptor signal transduction pathway is dissociated from the regulation of fluid-phase pinocytosis in the insulin-secreting beta-cell line we studied; and (3) the enhancement of fluid-phase pinocytosis associated with secretagogue-induced insulin release in beta TC6-F7 cells is not attributable to autocrine activation of beta-cell surface insulin receptors.

Androstadienes↗
PubMed1996

Predicting radon testing among university employees.

To determine covariates of radon testing behavior, we surveyed by mail a random sample of all Boston University employees (N = 915) six to nine months after they had been informed of the availability of radon testing services through the University's medical center. The response rate was 58%. Analysis suggests blue collar workers were underrepresented within the response rate. Slightly more than half of the respondents (51%) were men. The majority (69%) were under the age of 45. Twenty-seven percent of the respondents (N = 143) had tested their homes for radon. Bivariate analysis revealed important differences between radon testers and nontesters. Testers were 12 times more likely to be home owners than renters (p = 0.00), and were more knowledgeable about radon's characteristics and testing procedures (p = 0.00). Testers were more likely to view radon as a serious problem (p = 0.00), to consider radon testing efficacious (p = 0.00), and to consider themselves susceptible to exposure (p = 0.00). Testers were also less likely to perceive barriers to radon testing. We used logistic regression to compare the usefulness of the Health Belief Model and the Diffusion of Innovations Model in predicting radon testing. We concluded that the knowledge deficits and barriers to radon testing identified in this study should be targeted in radon educational interventions.

Behavior↗
PubMed1996

Employee attitudes toward work-site alcohol testing.

Few studies have been published on how employees feel about work-site alcohol testing. By mail, we surveyed employees (n = 6370) at 16 corporate work sites stratified by type of work force, industrial setting, and managerial tolerance toward drinking. We queried respondents about their drinking on the job and support for work-site alcohol testing under three conditions: pre-employment testing, testing after an accident, and random testing. Sixty-five percent of respondents supported pre-employment testing, 81% supported testing after an accident, and 49% supported random testing. Support was relatively consistent across hierarchy (managers, supervisors, and workers) but different by age, education, occupation, type of work force, and perceived exposure to occupational hazards. Support for work-site alcohol testing was highest among blue-collar workers whose jobs involved manufacturing or exposure to work-site hazards.

Accidents, Occupational↗
PubMed1996

Worksite barriers to the effective management of alcohol problems.

The purpose of this analysis is to describe barriers to workplace interventions in cases of alcohol abuse. A survey of 7255 supervisors in 114 worksites across seven major corporations was completed (79% responded). Information about barriers to intervention was elicited by 12 questions. Cluster analysis revealed three analytically independent classes of barriers--Organizational, Interpersonal, and Individual. Most managers reported encountering some barriers to intervention: the extent of barriers perceived was related to characteristics of the worksite, job, and/or the environment. Barriers were greatest for female managers, managers in larger worksites, and the first-line supervisors. Barriers were also related to the form (formal vs informal) of intervention a manager was willing to make. Intervention strategies must take into account differences between company worksites and job levels, and not assume that policies are equally effective throughout the corporation.

Alcoholism↗
PubMed1996

Why are most drowning victims men? Sex differences in aquatic skills and behaviors.

Men have higher drowning rates than women for most age groups. Data from a 1991 national household survey (n = 3042) on aquatic activities were used to examine hypotheses about differential drowning rates by sex. Men and women were compared by (1) exposure to aquatic environments; (2) frequency of aquatic activities involving or potentially involving, submersion; (3) swimming training and ability; (4) aquatic risk-taking behaviors; and (5) alcohol use on or near the water. Men had elevated risks for exposure, risk taking, and alcohol use. It was concluded that several factors contribute to their relatively high drowning rates, including a possible interaction between overestimation of abilities and heavy alcohol use.

Adolescent↗
PubMed1996

Reducing alcohol-impaired driving in Massachusetts: the Saving Lives Program.

OBJECTIVES: The purpose of this study ws to assess whether a community program begun in March 1988 that organized multiple city departments and private citizens could reduce alcohol-impaired driving, related driving risks, and traffic deaths and injuries. METHODS: Trends in fatal crashes and injuries per 100 crashes were compared in Saving Lives Program cities and the rest of Massachusetts from March 1984 through February 1993. In annual roadside surveys conducted at randomly selected locations, safety belt use among occupants of 54577 vehicles and travel speeds of 118442 vehicles were observed. Four statewide telephone surveys (n = 15188) monitored self-reported driving after drinking. RESULTS: In program cities relative to the rest of Massachusetts during the 5 program years in comparison with the previous 5 years, fatal crashes declined 25%, from 178 to 120, and fatal crashes involving alcohol decreased 42%, from 69 to 36. Visible injuries per 100 crashes declined 5%, from 21.1 to 16.6. The proportions of vehicles observed speeding and teenagers who drove after drinking were cut in half. CONCLUSIONS: Interventions organized by multiple city departments and private citizens can reduce driving after drinking, related driving risks, and traffic deaths and injuries.

Accidents, Traffic↗
PubMed1996

Expression of insulin receptor mRNA and insulin receptor substrate 1 in pancreatic islet beta-cells.

The expression of insulin receptor mRNA was examined in rat pancreatic islet cells by single-cell reverse transcriptase (RT)-polymerase chain reaction (PCR). Single cells from disaggregated islets were individually isolated in a microcapillary pipet, and the beta-cells were identified by amplification of the mRNA for insulin. We found that in single beta-cells, the mRNA for the insulin receptor was also expressed. The fraction of single islet cells expressing both insulin receptor and insulin mRNAs corresponds closely to the fraction of beta-cells in the disaggregated islet cell preparation. These results indicate that normal beta-cells have the potential to express authentic insulin receptors. Immunohistochemical analysis was insufficiently sensitive for assaying insulin receptor protein; however, insulin receptor substrate 1 (IRS-1) was readily immunolocalized in islet beta-cells. Since IRS-1 links several cell surface receptors, including those for insulin and IGF-I, to distal signal transduction pathways, our observations indicate that hormonal regulation of islet beta-cells potentially involves the same signal transduction pathway that mediates insulin and growth factor signaling in peripheral insulin target tissue cell types.

Animals↗
PubMed1996

Work-site variation in managerial drinking.

To assess cross-work-site variation in the general drinking behaviors (on and off the job) of employees, we conducted a cross-sectional survey of managers (n = 7255) at 114 places of work located throughout the continental United States. The work-site mean for the total number of drinks consumed on a typical drinking day ranged from 1.4 to 3.17, a two-fold differential. Regression analysis showed an independent work-site effect, controlling for respondents demographics and type of work. This finding suggests that modifiable work-site characteristics could influence what employees drink on and off the job.

Administrative Personnel↗
PubMed1995

Laparoscopic assisted vaginal hysterectomy: an audit plus a word of caution.

Laparoscopic assisted vaginal hysterectomy (LAVH) performed in 109 cases has been reviewed. In this series the mean operative time was 89 minutes and mean inpatient hospitalization was 3.7 days. Throughout the review, 6 patients were considered to have major complications and each is discussed. The association of previous caesarean section and bladder damage is noted. LAVH widens the indications available for vaginal hysterectomy in younger women in whom the abdominal approach would previously be indicated, but extra caution is advised when this technique is first introduced to a gynaecological service.

Adult↗
PubMed1994

Evaluation of an office- and hospital-based intervention to increase the use of cloth diapers.

To evaluate an office-based educational intervention to promote the use of cloth diapers, we randomly assigned parents of 193 infants either to the intervention group or to a control group. The intervention consisted of physician advice and written material on cloth and disposable diapers at the 2-week office visit. Midway through the study, one of the birth hospitals switched to the exclusive use of cloth diapers. The results indicate that the diapering decisions of parents can be influenced by practices in hospitals and by office-based physician and nurse counseling.

Adult↗
PubMed1993

Alcohol and non-traffic unintended injuries.

In a review of the English language literature on alcohol and unintentional injury we identified 21 studies on falls, 36 on drownings and 32 on burns from 1947-1986. The proportion of fatal and non-fatal fall victims who had been drinking ranged from 21-77%, and 18-53% respectively. In three more recent studies, 35-63% of persons fatally injured in falls had been drinking. In five other studies 13-37% of persons injured in non fatal falls had been drinking. In our earlier review of drowning studies with complete ascertainment and duration of submergence specified, 27-47% of those who drowned had positive BAC's. In eight subsequent studies, alcohol was identified in 21-47% of drowning deaths. In our earlier review alcohol was involved in 9-86% of burn deaths. In five more recent US studies, alcohol was found in 12-61% of fatally injured burn victims. Case control studies are needed to establish whether alcohol increases the risk of trauma. Studies are also needed of interventions to reduce the proportion of these injuries where alcohol is involved.

Accidental Falls↗
PubMed1993

Fear of falling among the community-dwelling elderly.

To assess the incidence of falls and the prevalence, intensity, and covariates of fear of falling among community-dwelling elderly, the authors surveyed a random sample of 196 residents (> or = 58 years of age) of housing developments for the elderly in Brookline and Plymouth, Massachusetts. Forty-three percent reported having fallen in recent years, 28% in the last year. Of those who had fallen within the year prior to the interview, 65% reported injury, 44% sought medical attention, and 15% required hospitalization as a consequence of their fall(s). Fear of falling ranked first when compared to other common fears (i.e., fear of robbery, financial fears). Self-rated health status and experience of previous falls were significantly associated with fear of falling. Further analysis suggests that fear of falling may affect social interaction, independent of risks for falling.

Accidental Falls↗
PubMed1992

Using chronic disease risk factors to adjust Medicare capitation payments.

This study evaluates the use of risk factors for chronic disease as health status adjusters for Medicare's capitation formula, the average adjusted per capita costs (AAPCC). Risk factor data for the surviving members of the Framingham Study cohort who were examined in 1982-83 were merged with 100 percent Medicare payment data for 1984 and 1985, matching on Social Security number and sex. Seven different AAPCC models were estimated to assess the independent contributions of risk factors and measures of prior utilization and disability in increasing the explanatory power of AAPCC. The findings suggest that inclusion of risk factors for chronic disease as health status adjusters can improve substantially the predictive accuracy of AAPCC.

Aged↗
PubMed1991

Falls and fear of falling among elderly persons living in the community: occupational therapy interventions.

Each year, about one third of the population over 65 years of age experiences at least one fall (Perry, 1982). Assessment of the incidence of falls and the prevalence, intensity, and covariates of fear of falling among community-based elderly persons was conducted through interviews of 115 residents in a housing development (mean age = 78 years). Fifty-three percent reported having fallen in recent years, 32% in the last year. Fear of falling ranked first when compared with other common fears. In a logistic regression model predicting limitation of activity independent of risk factors for falling, fear of falling was marginally significant (p = .06). The results of the study show that falls are frequent and fear of falling prevalent among the community-based elderly. A comprehensive program designed to reduce the risk of falls is presented.

Accidental Falls↗
PubMed1990

Effects of a rapid antigen test for group A streptococcal pharyngitis on physician prescribing and antibiotic costs.

Decision analysis and opinion survey suggest that introduction of rapid antigen detection tests should decrease the number of patients with negative test results for group A streptococcal pharyngitis treated by antibiotics. We reviewed all cases in which a test for group A streptococcal pharyngitis was performed during the last 7 months of culture diagnosis and the first 7 months of antigen test diagnosis at an inner city community health center, recording culture or antigen test results, whether antibiotics were prescribed, and patient status (as regular health center patients or patients referred to the center). Positive rates for culture and antigen-test periods were similar (10% and 12%), but 53% of patients with negative culture were treated, where only 32% of patients with negative antigen-test results received prescriptions. Significant reductions in the treatment of patients with negative test results were found in both patient-status subpopulations: health center patients, 43% to 29%; referred patients, 91% to 52%. Among health center patients reductions were consistent for both adult (30% to 21%) and child and adolescent (55% to 45%) age groups. For all patients with negative test results, direct costs of diagnostic reagents and antibiotic prescriptions fell from $3.58 per patient with culture to $3.45 with antigen testing; the $0.13 savings per patient was due to less treatment of referred patients. Thus, rapid antigen testing led to (1) significantly fewer patients with negative test results receiving antibiotic prescriptions; and, (2) savings in antibiotic costs offsetting reagent cost of antigen detection diagnosis.

Adolescent↗
PubMed1989

Barriers to bicycle helmet use among children. Results of focus groups with fourth, fifth, and sixth graders.

As a preliminary step in the development of a school-based educational intervention to promote bicycle helmet use among children, focus group encounters were conducted with fourth, fifth, and sixth graders at three elementary schools in the Boston, Mass, area. Analysis of transcripts of encounter tape recordings indicated that (1) the prevalence of helmet ownership and use was low, (2) children were concerned that helmet use would invite derision from their peers, and (3) children tended to respect other children who wore helmets. We concluded that focus groups can be useful in conceptualizing health education interventions and suggest that school-based peer-led bicycle helmet programs may be effective in developing normative change toward helmet use among elementary schoolchildren.

Adolescent↗