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Biomedical subjects

R M Davis

Publications and source records attributed to R M Davis.

At least 91 records · Page 5Linked to original sources
PubMed1991

National programs for smoking cessation.

The smoking cessation effort has made tremendous progress since the 1964 Report of the Surgeon General described the health hazards of smoking. The impact of these efforts on smoking is particularly impressive when the current smoking level is compared with levels of smoking projected from trends apparent before that 1964 report, levels that might have been reached if there had been no national stop-smoking campaign. Because of the campaign, an estimated 35 million Americans were nonsmokers in 1985 who would otherwise have been smokers. If these figures are projected to the year 2000, the campaign will have postponed more than 2 million deaths. Therefore, reducing the prevalence of smoking in adults from about 40% in 1964 to 29% in 1987 can be considered a tremendous public health achievement. Among those who did take up smoking, there is also reason for some optimism. By 1987, more than 38 million Americans had quit smoking; this figure represents nearly half of all living adults who ever smoked. The 1990 Report of the Surgeon General gave a positive message to the 50 million Americans who continue to smoke by describing the health benefits of quitting for all the major smoking-related diseases.

Female↗
PubMed1990

Quitting smoking in the United States in 1986.

In an analysis of recent behavior with regard to quitting smoking, detailed histories were obtained on a representative sample of 5,623 Americans who had smoked in the year preceding the 1986 Adult Use of Tobacco Survey. An estimated 55.8 million Americans smoked regularly for some period during the year prior to the survey. Approximately one third (34.8%) quit for at least a day during the year prior to the survey, 28.3% quit for at least 7 days during the year prior to the survey, and 16.2% were still not smoking at the time of the survey. Of those who quit for a day, 54% had relapsed by the time of the survey. Demographic characteristics, such as age, sex, race, marital status, and education, were evaluated as predictors of making a major attempt to quit for 7 days or more. Among those who had made a major attempt, a similar analysis was done predicting success in maintaining cessation for 3 months or more. Ordinal logistic regression analyses showed that younger age and higher education predicted a major attempt to quit. There was only one group who differed markedly from all others: those who were younger and were more highly educated. Older age and being white predicted those who abstained for 3 months or longer.

Adolescent↗
PubMed1990

'Common courtesy' and the elimination of passive smoking. Results of the 1987 National Health Interview Survey.

The tobacco industry recommends "common courtesy" as the solution to potential conflicts over smoking in public places and as an alternative to policies that restrict or ban smoking. Specifically, the industry suggests that nonsmokers "mention annoyances in a pleasant and friendly manner" and that smokers ask others, "Do you mind if I smoke?" We analyzed data for 22,000 adults who responded to the 1987 National Health Interview Survey of Cancer Epidemiology and Control to determine if common courtesy is being used in passive-smoking situations. Almost half (47%) of smokers said they light up inside public places without asking if others mind. When someone lights up a cigarette inside a public place, only 4% of nonsmokers ask the person not to smoke despite the fact that most nonsmokers consider secondhand smoke harmful and annoying. We compared these data with similar data collected by the Roper Organization in the 1970s and found that smokers today are less likely to smoke inside public places. However, nonsmokers' actions in response to secondhand smoke have changed very little. These findings show that the common courtesy approach endorsed by the tobacco industry is unlikely, by itself, to eliminate exposure to environmental tobacco smoke. Though no one would oppose the use of common courtesy, we conclude that legislative or administrative mechanisms are the only effective strategies to eliminate passive smoking.

Adult↗
PubMed1990

Human neuroectoderm-derived cell line secretes fibronectin that shares the HNK-1/10C5 carbohydrate epitope with neural cell adhesion molecules.

A human malignant melanoma cell line, Melur, secretes several glycoproteins that contain a unique carbohydrate epitope shared by neural cell adhesion molecules and recognized by the monoclonal antibodies HNK-1, L2, and 10C5. In this report, we present evidence that one of the major melanoma glycoproteins containing the HNK-1/10C5 epitope is the cell adhesion molecule, fibronectin, or a fibronectin-like molecule. Melanoma-derived fibronectin was isolated from serum-free conditioned medium by gelatin-Sepharose affinity adsorption and shown to react with monoclonal antibodies HNK-1 and 10C5 in Western blot analysis. HNK-1-containing fibronectin was purified on a gelatin-Sepharose column followed by an affinity column using a monoclonal antibody against the HNK-1 carbohydrate. The purified HNK-1-fibronectin then could be incorporated into the extracellular matrix of hamster fibroblasts in vitro, and such a matrix was detectable using the HNK-1 monoclonal antibody in an immunofluorescence assay. Of the seven neuroectoderm-derived tumor cell lines tested, only the Melur melanoma cell secreted fibronectin containing the HNK-1 carbohydrate. Identification of human neuroectoderm-derived fibronectin as a potential carrier of the HNK-1 carbohydrate suggests a new role for fibronectin in neural development and regeneration, and represents a new model for studying the function of this carbohydrate domain in neural cell adhesion.

Antigens, Differentiation↗
PubMed1990

Information on tar and nicotine yields on cigarette packages.

We examined information on tar and nicotine yields on the packages of 160 cigarette brands, 58 percent of the 275 brands for which tar and nicotine yields were listed in a recent Federal Trade Commission report. The tar yield was indicated on 14 percent, the nicotine yield was indicated on 11 percent. As tar yield increased among brands, the yield was progressively less likely to be shown on the package and was not disclosed on the package of any cigarette yielding 11 mg or more of tar.

Humans↗
PubMed1990

Corneal microsporidiosis. A case report including ultrastructural observations.

Stromal keratitis and iritis developed in the left eye of a healthy 45-year-old man with no history of ocular disease, trauma, or contact lens wear. The clinical course over a 2-year period was characterized by progressive central disciform keratitis, recurrent anterior stromal patchy infiltration, and iritis which was partially controlled with topical corticosteroids and broad-spectrum antibiotics. Results of bacterial, viral, fungal, and chlamydial cultures were negative. Results of histopathologic examination of a corneal biopsy specimen and, later, a penetrating keratoplasty specimen showed many extracellular and intracellular spores in degenerating keratocytes. By electron microscopy there were encapsulated oval structures measuring approximately 3.5 to 4 microns in length x 1.5 microns in width. Mature spores had well-developed cell walls that contained two abutted nuclei (diplokaryon) and a redundant polar tubule with six coils. These structures are characteristic of a protozoa in the genus Nosema.

Animals↗
PubMed1989

Human carboxypeptidase M. Purification and characterization of a membrane-bound carboxypeptidase that cleaves peptide hormones.

A membrane-bound neutral carboxypeptidase B-like enzyme was solubilized from human placental microvilli with 3-[(3-cholamidopropyl)-dimethylammonio]-1-propanesulfonate (CHAPS) and purified to homogeneity by ion-exchange chromatography and affinity chromatography on arginine-Sepharose. It gave a single band on sodium dodecyl sulfate-polyacrylamide gel electrophoresis with an apparent Mr of 62,000 with or without reduction. The enzyme is a glycoprotein as shown by its high affinity for concanavalin A-Sepharose and reduction in mass to 47,600 daltons after chemical deglycosylation. It has a neutral pH optimum, is activated by CoCl2, and inhibited by o-phenanthroline, 2-mercaptomethyl-3-guanidinoethylthiopropanoic acid, or cadmium acetate, indicating it is a metallopeptidase. The enzyme cleaves arginine or lysine from the COOH terminus of synthetic peptides (e.g. Bz-Gly-Arg, Bz-Gly-Lys, Bz-Ala-Lys, dansyl-Ala-Arg, where Bz is benzoyl and dansyl is 5-dimethylaminonaphthalene-1-sulfonyl) as well as from several biologically active substrates: dynorphin A(1-13), Met5-Arg6-enkephalin (Km = 46 microM, kcat = 934 min-1), bradykinin (Km = 16 microM, kcat = 147 min-1), Met5-Lys6-enkephalin (Km = 375 microM, kcat = 663 min-1), and Leu5-Arg6-enkephalin (Km = 63 microM, kcat = 106 min-1). Although the enzyme shares some properties with other carboxypeptidase B-like enzymes, it is structurally, catalytically, and immunologically distinct from pancreatic carboxypeptidase A or B, human plasma carboxypeptidase N, and carboxypeptidase H ("enkephalin convertase"). To denote that the enzyme is membrane-bound, and to distinguish it from other known carboxypeptidases, we propose the name "carboxypeptidase M." Because of its localization on the plasma membrane and optimal activity at neutral pH, carboxypeptidase M could inactivate or modulate the activity of peptide hormones either before or after their interaction with plasma membrane receptors.

Carboxypeptidases↗
PubMed1989

Trends in cigarette smoking in the United States. The changing influence of gender and race.

Trends in the prevalence, initiation, and cessation of cigarette smoking are reported for the US population using weighted and age-standardized data from seven National Health Interview Surveys (1974 to 1985). The decline in prevalence was linear, with the prevalence for men decreasing at 0.91 percentage points per year to 33.5% in 1985 and the prevalence for women decreasing at 0.33 percentage points per year to 27.6% in 1985. For whites the rate of decline (percentage points per year) was 0.57, to 29.4% in 1985, and for blacks the decline was 0.67, to 35.6% in 1985. Smoking cessation increased among all gender-race groups from 1974 to 1985, with the yearly rate of increase (in percentage points per year) about equivalent for blacks (0.75) and whites (0.77), while it was higher in women (0.90) than in men (0.67). Smoking initiation decreased among young men (-1.03), while it remained about the same in young women (+0.11). Initiation decreased at a more rapid rate in blacks (-1.02) than in whites (-0.35). We conclude that smoking prevalence is decreasing across all race-gender groups, although at a slower rate for women than men, and that differences in initiation, more than cessation, are primarily responsible for the converging of smoking prevalence rates among men and women.

Adult↗
PubMed1989

Trends in cigarette smoking in the United States. Educational differences are increasing.

National trends in smoking prevalence by educational category from 1974 through 1985 show that education has replaced gender as the major sociodemographic predictor of smoking status. Smoking prevalence has declined across all educational groups but the decline has occurred five times faster among the higher educated compared with the less educated. From 1974 to 1985, smoking prevalence among persons with less than a high school diploma declined to 34.2% (0.19 percentage points per year) whereas prevalence for persons with four years or more of college education declined to 18.4% (0.91 percentage points per year). Smoking cessation activity increased across all educational groups, but the rate of increase among the higher educated was twice that of lower-educated groups. Initiation of smoking among more-educated men decreased rapidly to 15% in 1985 but leveled off by 1987. Until 1985, less-educated young females were the only group in which smoking initiation was increasing. However, in 1987 a sudden and large decline in initiation among less-educated females occurred. The apparent recent changes in initiation patterns by educational level suggest that the converging of smoking prevalence between the genders may not continue. The large and widening educational gap in smoking suggests that health promotion priorities need to be reassessed.

Adult↗
PubMed1989

Trends in cigarette smoking in the United States. Projections to the year 2000.

Data from National Health Interview Surveys from 1974 through 1985 are used to project cigarette smoking prevalence to the year 2000. Smoking prevalence in the United States has declined at a linear rate since 1974. If this trend continues, in the year 2000, 22% of the adult population (40 million Americans) will be smokers. By the year 2000, the major inequalities in prevalence will occur among educational categories. At least 30% of those who have not proceeded beyond a high school education will be smokers, whereas less than 10% of college graduates will smoke. Among the other sociodemographic subgroups, smoking prevalence is expected to decrease by the year 2000 to 20% among men, to 23% among women, to 25% among blacks, and to 21% among whites. Between 1974 and 1985, approximately 1.3 million persons per year became former smokers, indicating considerable success in public health efforts to encourage people to stop smoking. However, in the early 1980s, approximately 1 million new young persons per year were recruited to the ranks of regular smokers. This is equivalent to about 3000 new smokers each day. Public health efforts need to focus more on preventing young people from starting to smoke, and such prevention efforts should particularly target less educated socioeconomic groups.

Adult↗
PubMed1989

The Surgeon General's warnings in outdoor cigarette advertising. Are they readable?

Outdoor advertising media represent a major vehicle by which cigarette companies promote their products. We investigated the readability of the Surgeon General's warning in cigarette advertisements (ads) in two outdoor media: billboards and taxicab ads. In an experiment in metropolitan Atlanta under typical driving conditions, observers were able to read the entire health warning on 18 (46%) of 39 street billboards but on only two (5%) of 39 highway billboards. In contrast, the content of the ads (ie, brand name, other wording, and notable imagery) could be recognized under the same conditions on more than 95% of the billboards. In a similar study of 100 taxicab cigarette ads in New York City, observers were unable to read the health warning in any of the ads but were able to identify the brand name in all ads and notable imagery in 95% of the ads. Significant differences between the readability of the warning and identification of the advertising content persisted even when partially read warnings were considered to have been read. We conclude that the Surgeon General's warning is not readable in its current form in the vast majority of billboard and taxicab ads. Factors contributing to unreadability include the small size of the letters, the excessive length of the warnings, the distance between the viewers and the ads, and movement between the viewers and the ads.

Advertising↗
PubMed1989

The epidemiology of cigarette smoking and its impact on chronic obstructive pulmonary disease.

Since the first Surgeon General's report on smoking and health was released in 1964, the United States has achieved substantial progress in curtailing smoking. Per capita cigarette sales for persons 18 yr of age or older have declined each year since 1973. Total cigarette sales have fallen an average of 1.8% each year since 1982, despite the increasing size of the population. National population-based surveys show that the prevalence of smoking has fallen steadily among adults during the past quarter century. Unfortunately, a parallel decrease in mortality from chronic obstructive pulmonary disease (COPD), one of the most important smoking-related diseases, has not occurred. To estimate the current impact of smoking on mortality from COPD, we used a modified formula for population attributable risk to calculate the mortality and years of potential life lost due to COPD caused by smoking. In 1984, an estimated 51,013 deaths occurred from COPD caused by smoking: 35,638 among men (85% of total COPD mortality) and 15,376 among women (69% of total COPD mortality) (sum does not equal total due to rounding). These deaths resulted in a total loss of 501,290 yr of life before the average life expectancy. We conclude that cigarette smoking continues to cause a heavy burden of premature death from COPD in the United States. This burden may increase in the coming years despite decreasing smoking rates because the residual risk of COPD mortality among former smokers persists for many years.

Adolescent↗
PubMed1989

The inaccessibility of seat belts in taxicabs.

The accessibility of seat belts was determined in a total sample of 200 taxicabs waiting to pick up passengers at eight city airports. A rear seat belt was "accessible" (able to be fastened within 10 seconds) in 111 (55.5 per cent) taxicabs. The proportion varied by city from 16.0 per cent (New York City) to 96.0 per cent (Minneapolis-St. Paul) and was higher for taxicabs in cities covered by mandatory state seat belt legislation.

Automobiles↗
PubMed1989

The reliability of self-reported cigarette consumption in the United States.

To investigate the possibility that self-reported smoking is not a valid measure for assessing trends in smoking prevalence, we compared total self-reported cigarette consumption with the adjusted consumption data from cigarette excise taxes as reported by the US Department of Agriculture (USDA) for the period 1974 through 1985. Self-reported consumption was calculated by using data from the National Health Interview Surveys (NHIS) for adults and from the National Household Surveys on Drug Abuse for adolescents. For this period, the average ratio of self-reported cigarette consumption to the USDA estimate of consumption was 0.72 (range = 0.69 to 0.78). There was no statistical difference in this consumption ratio from year to year, indicating no apparent increase in the underreporting of cigarette smoking in these surveys. We conclude that cross-sectional surveys of self-reported smoking status remain a reliable surveillance tool for monitoring changes in population smoking behavior.

Adolescent↗
PubMed1989

Smokeless tobacco use in the United States: the adult use of tobacco surveys.

Prevalence of smokeless tobacco use is reported for adults aged 21 years and older in the Adult Use of Tobacco Surveys, 1964-1986. Data from the 1986 survey on prevalence, beliefs, ages of initiation, and demographic correlates of use by males aged 17 years and older are also reported. The prevalence of smokeless tobacco use declined slightly among persons aged 21 and older between 1966 and 1986. However, 5.2% of the males aged 17 and older used smokeless tobacco in 1986, and prevalence was highest among those 17 to 19 years old (8.2%). The median age of initiation for both products was 19 years. Smokeless tobacco use was most common among white men who were 1) living in the southeastern United States, 2) unemployed, and 3) in blue-collar or service/labor employment. Most users (77.4%) and nonusers (83.4%) believe that smokeless tobacco is a health hazard. Many current users (39.1%) had attempted to quit. Some current (6.4%) and former smokers (7.0%) have used smokeless tobacco as an aid to smoking cessation. National survey data such as these permit the identification of high-risk groups, so that interventions against smokeless tobacco use may be specifically targeted.

Adolescent↗