Confounders contributing to the reported associations of coffee or caffeine with disease

The role of caffeine or coffee in causing or promoting the incidence of serious disease is equivocal. Two design factors may account for the discrepancies in reported findings on the effects of coffee drinking: (a) imprecision of measurement and (b) confounding variables. A study of 2,714 white U.S. adults disclosed that, of 32 risk factors analyzed by linear and logistic regression, only sex and cigarette smoking were found to be important potential confounders of caffeine and coffee intake. Partial R2 values of the other 30 risk factors were relatively small and were inconsistent for each sex. It is unlikely that any of these factors could explain any of the reported associations between caffeine or coffee consumption and certain diseases. However, certain weak associations with caffeine or coffee intake should be included in the study design when they are known to be risk factors of a disease under investigation. These factors for men are dietary fat intake, vitamin C intake, and body mass index; and for women are vitamin use, alcohol intake, stress, and perceived health status.     

Relation between energy expenditure and body composition in man: specific energy expenditure in vivo of fat and fat-free tissue

The relationship between energy expenditure and body composition, in terms of fat and fat-free masses, has previously been described by a variety of predictive regression equations with parameters devoid of physiological content. We present here results obtained by calculating the specific energy expenditure, ie, the energy expenditure per unit of mass, of fat and fat-free tissue on the basis of measurements of the total energy expenditure (EE), the masses of fat (FM), and fat-free (FFM) tissue using the following simple model: EE = k1.FM + k2.FFM where k1 and k2 are the specific energy expenditures of fat and fat-free tissue, respectively. The results of observations on 104 women at rest yielded values for k1 and k2 of 0.31 and 1.35 watts/kg of fat and fat-free mass, respectively, with standard errors of estimate of 0.074 and 0.052 watts/kg, respectively. Analysis of several series of measurements, from other sources and on smaller samples of subjects, yielded similar values at rest but with larger standard errors of estimate. Data from subjects performing varying amounts of work in 24-h measurements showed, as expected, larger values for both tissues. The results explain to a very large extent the well-established relation between resting metabolic rate and body weight, ie, a linear relation with a non-zero intercept. The results also offer a clear-cut explanation for the well known difference in energy expenditure between men and women with the same body weight.     

Human interleukin 4 regulates the phenotype of lymphocytes generated during mixed lymphocyte culture and inhibits the IL-2-induced development of LAK function in normal and leukaemic cells

This study examined the immunoregulatory role of recombinant interleukin 4 (IL-4), also known as B-cell stimulating factor 1, on the generation of cytotoxic effector cells from normal and leukaemic human blood mononuclear cells. When tested on cells from normal individuals, the addition of IL-4 to mixed lymphocyte cultures led to a dose-dependent proliferation of T-helper cells (CD3, 4 positive) with a concomitant decrease in phenotypic and functional cytotoxic T cells and natural killer (NK) cells. IL-4 also inhibited the interleukin-2 (IL-2)-induced generation of lymphokine-activated killer (LAK) activity when added at the beginning of mixed lymphocyte culture. When tested on mature leukaemic NK cells, IL-4 also inhibited the ability of IL-2 to induce LAK function using a short-term culture system. These results show that IL-4 acts on both normal and leukaemic cells and suggests that it acts at more than one level during the development of LAK function.     

Two approaches to social support in smoking cessation: Commodity model and nondirective support

The commodity model of social support and features of Nondirective Support may clarify varied results of support interventions for smoking cessation. A commodity model views social support as attractive in and of itself and as an alternative to high-risk choices such as smoking. If such support is easily accessible, a would-be quitter is less likely to choose to smoke. Consistent with the commodity model, social support interventions tend to be effective as long as support remains available, but they lose their effects when support is terminated. From a second approach, Nondirective Support entails accepting recipients' goals, cooperating without taking control, and validating recipients' feelings. In contrast, Directive Support entails taking control and telling recipients what to do and feel. Review of support interventions indicates the value of the continued availability of support suggested by the commodity model and of Nondirective Support's flexibility and responsiveness to the person.     

Eating to beat breast cancer: Potential role for soy supplements

Background: The study reviews the anticancer properties of naturalisoflavones which occur in especially high concentration in soybeans. Itconsiders the suitability of soybean products for clinical trials aiming toreduce the progression of breast cancer.Methods: Evidence is reviewed that plant isoflavones such asgenistein show cytostatic activity against human mammary cancer cell linesin vitro and can also suppress carcinogen-induced mammary cancer inyoung and mature rats.Results: Plant isoflavones are converted in the bowel to compoundswith potential antioestrogenic and antioxidative properties. These compoundsshow cytostatic activity for both oestrogen receptor-positive and negativehuman mammary cancer cell lines, and also inhibit growth and progress of therat mammary cancer model. The high content of soybean products in the diet ofAsian women has been postulated as one reason for their relatively low breastcancer incidence.Conclusion: Preclinical studies suggest that soybean products begiven priority for clinical trials in breast cancer protection. A pilot studycould test soy protein supplements as long-term adjuvant dietary treatmentafter primary surgery for early breast cancer, looking for a decrease in therisk of recurrence or of second primary tumours.     

Recurrent dislocation of the patella and the Goldthwait operation

In this study 17 patients with recurrent dislocation of the patella were followed up 10 years after their Goldthwait operation. The subjective and clinical findings were excellent or good in 70%. X-radiographs indicated osteoarthritis of the femoropatellar joint in 60%. Concerning the aetiopathological factors, we found an increased external torsion of the afflicted extremity (measured by computed tomography).     

Reduced alcohol use in pregnancy and changed attitudes in the population

The objectives of this study were to investigate (1) changes in consumption of alcohol among pregnant women over a period of 5 years (1984/85–1990), (2) changes of attitudes towards drinking during pregnancy in the general population over the same period of time, and (3) possible connections between (1) and (2). The investigation was designed as a cross-sectional study. Our subjects were two representative samples of pregnant women in Oslo, n = 577 and 425, and two representative samples of the Norwegian population, n = 1004 and 1204. The main outcome measures were a self-completed questionnaire for the pregnant women and a personal interview for the general population sample. There was a significant reduction (50% decrease) in alcohol consumption among the second cohort of pregnant women compared with the first. Furthermore, we found an increase during the 5-year period in the number of persons with a restrictive attitude towards alcohol use during pregnancy. There seems to be a connection between these two phenomena, but with our present state of knowledge it is hard to say anything about the causal relationship between them.     

Isolated cavernous bodies

Corpus cavernosography in a patient with erectile dysfunction revealed absence of communication between the 2 cavernous bodies. No similar case was found in a review of 100 consecutive cavernosograms or in the literature. The abnormality may be a source of error in pressure recordings or in intravenous injection of pharmaceutical agents.     

The vascular laboratory. Standards and certification

The diversity of testing methodologies and reporting practices has necessitated that standards be defined for both performance of testing as well as interpretation and reporting of results. The guidelines to be used for the noninvasive diagnosis of extracranial vascular disease and the rationale for their use are presented. Emphasis is placed upon realistic diagnostic features that have clinical relevance and the use of testing methods that can identity these features. Further developments in this field, particularly those addressing the overall performance of vascular diagnostic laboratories, are to be defined by a multiprofessional inter-societal commission in the near future. It is anticipated that a voluntary accreditation process will insure high quality of testing.