Serum cholesterol and colorectal polyps.

Colorectal cancer and hypocholesterolemia have recently been associated, and colorectal polyps have a known relationship with colorectal cancer. In order to establish further evidence regarding the nature of the serum cholesterol-colorectal cancer relationship, this study investigated the hypothesis that men with colorectal polyps would have lower serum cholesterol levels than men without polyps. Of the 1380 men screened by sigmoidoscopy for colorectal polyps, 246 had at least one polyp. The men with polyps were older than those without, and also had higher cholesterol levels, but after controlling for age, there were no serum cholesterol differences. These data suggest that low serum cholesterol is not etiologically linked to cancer. Analyses of potentially confounding variables showed smoking to be strongly related to the presence of polyps.

Physical, subjective, and social availability: their relationship to alcohol consumption in rural and urban areas.

The alcohol availability literature indicates that under some conditions, physical availability is positively associated with per capita alcohol consumption. Smart (1980) suggested that at the individual level, subjective and social aspects of availability may mediate and outweigh the influence of physical availability. The study described here examined the simultaneous effects of physical, subjective, and social availability on alcohol consumption. Standardized telephone interviews were conducted with 781 adult drinkers. As hypothesized, physical availability was not a significant multivariate predictor of alcohol consumption for residents of high, medium, and low alcohol outlet density counties in Michigan (USA). Subjective and social availability indicators were significant predictors of alcohol consumption. Similar patterns of results were found in multiple regression analyses for blacks and whites and women and men, although blacks and women consumed less alcohol than did whites and men. The theoretical and practical implications of these results are discussed.

The relationship between reasons for drinking alcohol and alcohol consumption: an interactional approach.

Two motives for alcohol consumption have been emphasized in the etiological and the reasons-for-drinking literature: (a) people drink alcohol to cope with stress, and (b) people drink alcohol because of social influences. There is support for both of these hypotheses, but the results are usually modest and most authors agree that more complex theories of alcohol consumption are needed. This study examined the interactional effects of reasons for drinking alcohol and situational factors on alcohol consumption. Standardized telephone interviews were conducted with 781 randomly selected Michigan drinkers. Hierarchical multiple regression analyses indicated that gender, friends' alcohol consumption, coping, and social motives for drinking were significant predictors of study participants' alcohol consumption. As predicted, there was a significant interaction between drinking to cope with stress and perceived stress, and there was also a significant interaction between drinking for social reasons and friends' alcohol consumption. Similarities and differences in the results for women, men, Blacks, and Whites are described.

Reasons for drinking alcohol: their relationship to psychosocial variables and alcohol consumption.

The present investigation was designed to gain a better understanding of the psychosocial factors that predict reasons for drinking alcohol and how these drinking motives differentially relate to alcohol consumption. Four distinct reasons for drinking alcohol scales were established through factor analysis: drink to cope, drink to be sociable, drink to enhance social confidence, and drink for enjoyment. Multiple regression analyses showed that 1) each reason for drinking was predicted by a somewhat different set of demographic and psychosocial variables, and 2) the reasons for drinking, in turn, differentially predicted multiple indicators of quantity and frequency of alcohol consumption. Theoretical implications of the study results and suggestions for future research are discussed.

Physician accuracy in diagnosing colorectal polyps.

Since the medical management of persons with adenomatous colorectal polyps differs from that of those with hyperplastic polyps, accuracy of diagnosis is essential. Although many physicians have grown confident that their skills of visual diagnosis are adequate, few data exist to support this confidence. In order to examine the accuracy of physicians' judgments regarding colorectal polyp histology, the visual diagnosis of physicians experienced in endoscopy was compared with the histologic report. Eighty-one polyps were discovered by flexible sigmoidoscopy among 718 participants in a colon cancer screening program. Eighty percent of all polyps were detected accurately. The diagnostic sensitivity of detecting adenomas was 69 percent, while specificity (accurate diagnosis of hyperplastic polyps) was 86 percent, and there were an additional eight false negative and eight false positive diagnoses. Further analyses revealed that there are individual patterns of diagnostic mistakes made by physicians and that mistakes frequently are related to polyp size. These findings are particularly important in light of the expanding numbers of relatively inexperienced primary care providers performing flexible sigmoidoscopy whose diagnoses may be strongly dependent on polyp size.

Subjective, social, and physical availability. I. Their interrelationships.

The alcohol availability literature suggests that physical conditions which restrict alcohol availability reduce rates of alcohol consumption. Smart (1980) argued that the availability construct should be expanded to include subjective and social components. It was hypothesized that people who perceived alcohol to be subjectively and socially available would consume more alcohol than those who did not and that physical availability would only indirectly affect consumption. These hypotheses were examined using data from a telephone survey. In Part I, the interrelationships between physical, subjective, and social availability are described. In Part II (this journal, Vol. 25, No. 9), the relationships between these variables and alcohol consumption are explored.

Subjective, social, and physical availability. II. Their simultaneous effects on alcohol consumption.

Part I of this (this journal, Vol. 25, No. 8, pp. 889-910) series described the theoretical justification for this research, the methods and measures used, and the interrelationships between indicators of physical, subjective, and social availability. Part II explores the relationships between these variables and alcohol consumption using bivariate analyses and structural equation modeling. As predicted, for these metropolitan residents, physical distance from an outlet only indirectly related to alcohol consumption via its negative relationship to subjective availability. Indicators of both subjective and social availability positively related to alcohol consumption. The implications of these results for future availability research and prevention programming are discussed.

Preventing homicide: an evaluation of the efficacy of a Detroit gun ordinance.

BACKGROUND: In November 1986, a Detroit, Michigan city ordinance requiring mandatory jail sentences for illegally carrying a firearm in public was passed to preserve "the public peace, health, safety, and welfare of the people." METHODS: We conducted a set of interrupted time-series analyses to evaluate the impact of the law on the incidence of homicides, hypothesizing that the ordinance, by its nature, would affect only firearm homicides and homicides committed outside (e.g., on the street). RESULTS: The incidence of homicide in general increased after the law was passed, but the increases in non-firearm homicides and homicides committed inside (e.g., in a home) were either statistically significant or approached statistical significance (p = .006 and p = .070, respectively), whereas changes in the incidence of firearm homicides and homicides committed outside were not statistically significant (p = .238 and p = .418, respectively). We also determined that the ordinance was essentially unenforced, apparently because of a critical shortage of jail space. CONCLUSIONS: Our findings are consistent with a model in which the ordinance had a dampening effect on firearm homicides occurring in public in Detroit. The apparent preventive effect evident in the time series analyses may have been due to publicity about the ordinance, whereas the small nature of the effect may have been due to the lack of enforcement.

Amidative peptide processing and vascular function.

Substance P (SP), an amidated peptide present in many sensory nerves, is known to affect cardiovascular function, and exogenously supplied SP has been shown to activate nitric oxide synthase (NOS) in endothelial cells. We now report that SP-Gly, the glycine-extended biosynthetic precursor of SP (which is enzymatically processed to the mature amidated SP), causes relaxation of rat aortic strips with an efficacy and potency comparable to that of SP itself. Pretreatment of the aortic strips with 4-phenyl-3-butenoic acid (PBA), an irreversible amidating enzyme inactivator, results in marked inhibition of the vasodilation activity induced by SP-Gly but not of that induced by SP itself. Isolated endothelial cell basal NOS activity is also decreased by pretreatment with PBA, with no evidence of cell death or direct action of PBA on NOS activity. Both bifunctional and monofunctional forms of amidating enzymes are present in endothelial cells, as evidenced by affinity chromatography and Western blot analysis. These results provide evidence for a link between amidative peptide processing, NOS activation in endothelial cells, and vasodilation and suggest that a product of amidative processing provides intrinsic basal activation of NOS in endothelial cells.