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Biomedical subjects

J R Hebert

Publications and source records attributed to J R Hebert.

At least 91 records · Page 5Linked to original sources
PubMed1990

Indicators of nutritional status among clients from a New York City methadone treatment center.

As the AIDS epidemic in the United States moves steadily into the IV drug-abusing population, knowledge of factors related to immune suppression and disease progression gain in public health importance. Indicators of nutritional status, consisting of anthropometric and hematologic data as well as demographic data, were obtained from a random sample of 130 clients in a New York City methadone treatment center. Subjects for this study were selected according to the entry criteria established for inclusion in a large-scale study of the role of nutritional factors and cell-mediated immunity in a group at high risk of HIV seropositivity. Our results indicate a larger than U.S. population-average heterogeneity for Body Mass Index, hematocrit, and hemoglobin concentration, parameters which are conventionally thought to be proxies for general nutritional status. The findings indicate that while some methadone treatment clients are at low nutritional risk, others are probably at very high risk of adverse drug-nutrient and drug-body habitus interactions as well as being at high risk of acquiring infections commonly associated with HIV-related immunodeficiency.

Adult↗
PubMed1990

A proxy approach to the determination of total caloric intake for use in cancer epidemiology.

In the absence of complete dietary information on a cohort of 472 early-stage breast cancer patients a caloric prediction technique was developed. Deriving an accurate caloric denominator would enable examination of individual nutrient effects by controlling for potential confounding by calories. Surrogate measures of mean daily caloric intake were generated from estimates of basal metabolic rate (BMR) predicted from age, height, weight, and physical activity. A validation study was undertaken to test the relationship between the BMR proxy terms and mean daily energy intake obtained from four-day food diaries for 51 subjects. Pearson correlation coefficients between the diary-derived and predicted values of caloric intake were computed (r = 0.43, p = 0.001). The results are in the range of what many researchers found when comparing self-reports of total caloric intake in validation and reliability studies of various dietary assessment tools. Because of the large heterogeneity of results across the ages represented in this study (25-77 yrs), it is recommended that small validation studies of this type be carried out in the subpopulations of interest.

Adult↗
PubMed1990

Relationships between food consumption and dietary intake among healthy volunteers and implications for meeting dietary goals.

Quantitative food frequency questionnaires and 5-day food records were used to explore relationships between food consumption and nutrient intake among 65 healthy volunteers who were willing to participate in a dietary fiber intervention study. Spearman's correlation coefficient was calculated between the nutrient intake and the frequency of consumption of each food item, as well as the amount consumed per month. Percentage of calories from fat was related to frequency of consumption and amount of consumption, respectively, of bacon (r = .48, .49), frankfurters and sausage (r = .45, .45), and french fries and fried potatoes (r = .43, .39). Frequency and amount, respectively, of consumption of fruits were most highly correlated with intake of vitamin A (r = .45, .46), vitamin C (r = .44, .48), and dietary fiber (r = .43, .43). We conclude that specific food consumption amounts and/or frequency of eating foods such as legumes, fruits, and whole-grain or bran-rich cereals should be recommended to assist individuals in meeting dietary goals.

Adult↗
PubMed1990

Changes in AIDS risk behavior among intravenous drug abusers in New York City.

Forty newly admitted patients to a methadone treatment clinic in New York City were interviewed to assess their patterns of intravenous (IV) drug abuse, sexual activity, and other risk behaviors for the acquired immunodeficiency syndrome (AIDS). The study revealed a marked decline in needle sharing since 1984 (46% to 14%), despite a concurrent doubling of the number of weekly IV drug injections per subject (10 to 21). High rates of promiscuous heterosexual activity were noted among men (80% said they were currently active with more than one woman), while the rates of condom use were low, as reported by both men and women (less than 30%). Recent reduction in weight were reported by 40% of subjects, and the average body mass of all individuals was subnormal. Thus, despite an apparent decline in needle sharing, high risk sexual behavior is apparently persisting, drug use is increasing, and nutritional deficits are prevalent among IV drug abusers. Synergism of these factors should be considered in the manifestation of HIV infection among IV drug abusers.

Acquired Immunodeficiency Syndrome↗
PubMed1990

Differences in dietary intake associated with smoking status.

This study was designed to identify and describe smoking-related differences in dietary and nutritional factors that are potential independent predictors of cancer risk or effect modifiers or confounders of tobacco-cancer relationships. Data were obtained from a large hospital-based case-control study which was designed to estimate the cancer risk from various tobacco products and consisted of 465 male and 300 female incident lung cancer cases and 870 male and 556 female hospitalized patient controls matched on sex and age (+/- 5 years). Nutritional data were analysed as log-transformed frequencies of thirty food items, nine factor scores generated to describe overall patterns of dietary intake, and estimated daily nutrient scores for fat, vitamin A, fibre, and cholesterol. In general, the dietary habits of ex-smokers more closely resembled those of never-smokers than those of current smokers. We found that after controlling for case-control status, education, alcohol consumption, and age, there were many more significant differences in nutritional exposures by smoking status than could be explained merely by chance. For both sexes we observed significantly increased consumption of fruits and higher vitamin A and fibre scores in non-smokers compared to current smokers (for any smoking vs non-smoking comparison the P-value was always less than 0.002, 0.01, and 0.007, respectively). A similar but weaker relationship was observed for high-fat, sweet foods such as ice cream. An inverse association, also of smaller magnitude, was found for other high-fat foods items. Implications for further study and strengths and weaknesses of the current study are discussed.

Case-Control Studies↗
PubMed1989

Cancer risk in male veterans utilizing the Veterans Administration medical system.

Age-specific incidence curves, cumulative rates, and relative risks were estimated for selected malignancies among male veterans utilizing the Veterans Administration (VA) medical system during 1970 to 1982. Relative risks for malignant tumors of the lung, bronchus, larynx, oral cavity, and esophagus in males using VA hospitals were approximately double the rates for men of the Surveillance, Epidemiology, and End Results (SEER) cancer registry, thereby supporting the existence of strong effects of chronic cigarette smoking and alcohol consumption on the development of neoplasms at these specific anatomic sites. Relative to the SEER male population, there were significant reductions in the cumulative rates of neoplasms of the colon (15%) and extrahepatic biliary tract (30%), no differences in the rates of cancer of the stomach, small intestine, or pancreas, and a 50% increase in the cumulative rate of liver cancer among the veterans. Rates of malignancies of the genitourinary tract were similar in the VA and SEER registries with the exception of cancer of the penis, for which the cumulative rate was 50% higher in the veterans. These results are consistent with an excess of specific risk exposures among male veterans using VA hospitals, viz., cigarette smoking, alcohol consumption, poor nutrition, and other factors related to low socioeconomic status. The ultimate utility of the VA tumor registry will depend upon its exploitation by epidemiologists to provide leads for etiologic research.

Adult↗
PubMed1989

Risk factors for oral cancer in women.

Interviews were obtained from 125 women with oral cavity cancer and 107 female controls to assess the role of mouthwash use as a risk factor for oral cancer in women. In addition to detailed information on mouthwash use throughout adult life, information was obtained regarding smoking, alcohol consumption, general oral hygiene practices, and occurrence of nonmalignant conditions of the oral cavity. Mouthwash use was not associated with increased oral cancer risk in terms of frequency, duration of use, dilution, or rinsing practices. Among mouthwash users, cases reported taking more mouthfuls of mouthwash at each use compared with controls. Again among mouthwash users, cases were significantly more likely than controls to give as a reason for using mouthwash "to disguise the smell of tobacco" and "to disguise the smell of alcohol," whereas similar proportions of cases and controls reported using mouthwash to "disguise the smell of onions, garlic, etc." and "to disguise breath odors due to mouth infections or dental problems." These first two reasons for using mouthwash were strongly associated with smoking and drinking, respectively, and appear to be proxies for these exposures. Smoking, drinking, having 10 or more missing teeth, and religious background (non-Jewish versus Jewish) were significantly associated with oral cancer.

Alcohol Drinking↗
PubMed1989

Dietary fat and natural-killer-cell activity.

An intervention trial designed to lower the amount of fat in the diet was conducted to test the effect of reduced fat consumption (LF diet) on activity of natural killer (NK) cells in humans. Of 26 men enrolled initially, 17 successfully completed the intervention and lowered their fat intake to less than 30% of calories as fat. Data were analyzed in two ways. The paired t test showed a marked increase in NK-cell activity from baseline to the end of the LF-diet intervention (t = 4.77, p = 0.0002). Results of a general linear model showed an effect of lowering total dietary fat on increased NK-cell activity (approximately 0.53% increase for each absolute percent of calories as fat, p = 0.14) for all men and a highly significant effect in a subset of men who ate greater than 25% of calories as fat at baseline (approximately 1.22% increase, p = 0.009). These results were obtained after changes in total caloric intake, weight, exercise, and other fat-related covariates were accounted for.

Adult↗
PubMed1989

Menthol cigarette smoking and oesophageal cancer.

Oesophageal cancer incidence and mortality among American blacks is over three times the rate for whites. Between 1950 and 1977 the age-adjusted oesophageal cancer mortality rate approximately doubled in non-whites while remaining virtually unchanged in whites. Between World War II and the 1970s menthol cigarette sales dramatically increased, roughly paralleling the increase in oesophageal cancer among blacks. The present study uses existing data from a large hospital-based case-control study to test whether menthol cigarette smoking is related to oesophageal cancer. Oesophageal cancer cases were current smokers. Controls were matched to the cases on age (+/- 5 years) and sex, had conditions thought not to be related to tobacco use, and were also current smokers. Tabular analyses showed no change in risk for males ever-smoking menthol versus those never smoking menthol cigarettes. For women, however, there was an increased risk. Results of logistic regression analyses performed to account for potential confounding factors showed a marginally significant (P = 0.08) decrease in risk among male short term (less than 10 years) menthol smokers versus male never-menthol smokers (OR = 0.50, 95% Cl: 0.23-1.07) but no increased risk for menthol smoking of longer duration. Duration of menthol smoking fitted as a continuous variable showed no increased risk (P = 0.9) after accounting for non-menthol cigarette smoking duration (about 2% per year increase, P = 0.02). For females, the logistic analysis produced a marginally significant (P = 0.07) increased risk for longer menthol use (OR = 2.30, 95% Cl: 0.93-5.72).(ABSTRACT TRUNCATED AT 250 WORDS)

Black or African American↗
PubMed1989

Dietary exposures and other factors of possible prognostic significance in relation to tumour size and nodal involvement in early-stage breast cancer.

In this case series study of 546 early-stage breast cancer patients we examined the relationship between tumour size and axillary nodal involvement separately in relation to other factors suggested to be of prognostic significance in breast cancer. Relationships were modelled using two-stage general linear models stratified by menopausal status. In stage I models, tumour size (diameter in cm) and nodal involvement, expressed as the loge (number of positive nodes total nodes examined), were regressed on an array of socio-demographic and reproduction-related variables as well as smoking and drinking. In stage II models we entered the same dependent variables, the linear predictor score from stage I modelling, estimated total calories consumed and calorie-adjusted fat, fibre and vitamin A intake, as well as serum cholesterol, body mass index, and oestrogen and progesterone receptor status. Using this very conservative analytical technique, we found that, among premenopausal women, for every gram increase in estimated calorie-adjusted daily fat intake there was a 0.09 mm increase in tumour diameter (T = 2.58, P = 0.01). Also among premenopausal women, we observed an inverse relationship between nodal involvement and fibre intake (g/d) and nodal involvement (B = -0.058, T = -2.11, P = 0.04). For postmenopausal women we observed an inverse relationship with serum cholesterol (mg/dl) (B = -0.005, T = -1.85, P = 0.07). Other findings of interest include the absence of background factor effects in premenopausal women, the lack of nutritional effects and the consistency of a protective effect of education among postmenopausal women, and a relationship between hormone receptor levels and tumour size among premenopausal women.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1988

Weight, height and body mass index in the prognosis of breast cancer: early results of a prospective study.

The hypothesis that obesity plays a role in the prognosis of breast cancer is examined in this preliminary analysis of a follow-up study of 472 early-stage breast cancer patients. The 75th percentile values of weight (= 73 kg) and body mass index (BMI = 28) in the total patient population were taken as the cut points for estimating overweight or "obesity". Stratified, survival, and logistic regression analyses showed that increased weight or BMI, but not height, were associated with increased risk recurrence. In the logistic regression analysis, after accounting for other risk factors, stage III was a negative prognostic indicator of recurrence (with stage I as the referent group, OR = 3.46, 95% CI: 1.36-8.81). Women whose weights were above the 75th percentile value had a significantly increased risk of recurrence in relation to the other women (OR = 3.55, 95% CI: 1.65-7.65). Results from a model substituting BMI for weight showed a similar significant result. The adequacy of using anthropometric indices as proxies for obesity and various biological mechanisms, which may explain the relationship, are discussed.

Adult↗
PubMed1988

Bladder cancer in relation to cigarette smoking.

The importance of smoking-related variables in the development of bladder cancer was examined in data from a hospital-based case-control study of 1316 male and 505 female cases, and 3940 male and 1504 female age-matched controls interviewed in 20 hospitals from 9 United States cities between 1969 and 1984. For male current smokers, odds ratios for number of cigarettes smoked per day (cpd) increased to approximately 2.5 for smokers of more than 20 cpd, after adjustment for duration and nonsmoking-related covariates. Above 20 cpd, no further increase in odds ratio was observed. In females, the adjusted odds ratios showed no significant effect of increasing cpd level. In males, the odds ratios for duration increased from 1.18 (0.52-2.72) in those who smoke for less than 20 years to 2.31 (1.65-3.24) in those who smoked for greater than 40 years. In females, the corresponding odds ratios were 0.97 (0.27-3.44) and 1.62 (1.00-2.62). The results did not suggest an increased risk with early age at start of smoking in either sex. Ex-cigarette smokers, as a whole, had reduced odds ratios for bladder cancer, but the extent of the reduction was similar in short-term and longer-term quitters. The findings of this investigations support an association between smoking and bladder cancer. The pattern of risk associated with cpd and duration among current smokers and the early decline in risk associated with quitting are discussed in relation to possible mechanisms of bladder carcinogenesis.

Adult↗
PubMed1988

Effect of the type of cigarette smoked on bladder cancer risk.

The relationship between the type of cigarette smoked and bladder cancer risk was examined in data from a hospital-based case-control study. Information on smoking, including filtered and nonfiltered cigarette use, was available for 899 male and 427 female patients and 2713 male and 1243 female age-matched controls interviewed in 20 hospitals from nine cities in the US between 1969 and 1984. Smokers of filtered cigarettes had a slightly reduced risk of bladder cancer relative to smokers of nonfiltered cigarettes (odds ratio 0.64, 95% confidence interval 0.38 to 1.10 among male smokers; odds ratio 0.74, 95% confidence interval 0.37 to 1.48 among female smokers). In both sexes there was no statistically significant reduction in risk among switchers from nonfiltered to filtered cigarettes compared with lifetime nonfiltered cigarette smokers (odds ratio 0.93, 95% confidence interval 0.71 to 1.24 among male smokers; odds ratio 0.76, 95% confidence interval 0.40 to 1.46 among female smokers). The causal implications of these findings, in particular a possible initiation effect of tobacco smoke on bladder carcinogenesis, are discussed.

Epidemiologic Methods↗
PubMed1988

Dietary fat and natural killer cell activity.

Evidence from a number of sources implicates dietary fat in the etiology of various human cancers. We hypothesize a possible mechanism by which fat might increase tumorigenesis. Specifically, we discuss the connection between polyunsaturated fatty acids, prostaglandin synthesis, and the potential effect on Natural Killer (NK) cell activity. Polyunsaturated fatty acid-induced increases in series-2 prostaglandin synthesis could result in depressing NK-cell activity. As the first line of defense against tumor cells, NK-cell function may be particularly important in modifying cancer risk.

Animals↗
PubMed1988

On the possible relationship between AIDS and nutrition.

It is noted that host resistance or susceptibility factors are important in determining the probability of contracting many diseases. Though AIDS has been studied primarily in terms of exposure to disease agents, it is proposed that factors affecting susceptibility or resistance be considered. Because of its effect on cellular immunity, nutritional stress is proposed as a plausible determinant of increased risk. Specific mechanisms are discussed and a connection between diverse risk groups is proposed.

Acquired Immunodeficiency Syndrome↗
PubMed1988

Smoking and adult leukemia: a case-control study.

Existing data from a large case-control study of tobacco-related cancers were used to examine the relationship between smoking history and leukemia as a whole, as well as specific morphologic types of leukemia. A total of 342 male and 220 female leukemia cases and two series of patients with non-tobacco related conditions (non-cancer controls: N = 9349 and cancer controls: N = 9846) were available for study. Analyses were carried out for all leukemia cases combined and for ANLL (N = 249), ALL (N = 52), CML (N = 78), and CLL (N = 57) separately vs both control groups. In addition to crude and age-adjusted odds ratios and their 95% confidence intervals, logistic regression models including potential confounding variables were used. No positive association with smoking was seen either for all cases combined or for any of the four specific morphologic types.

Adult↗
PubMed1988

Methodologic considerations for investigating the diet-cancer link.

Evidence from human ecological studies and experimental animal studies suggest that a number of dietary factors may have a role in the etiology of cancers of various sites. When associations are examined within populations on the level of the individual, they often weaken or disappear. Although in some cases the suspect nutrient may have no real carcinogenic effect, it is proposed that there are at least three important methodologic problems that could prevent the observation of a true association between dietary factors and human cancer. First, diet assessment methods are inadequate to estimate true exposure with sufficient accuracy and precision especially over long periods. Second, use of retrospective diet assessment methods in case-control study designs can often introduce an important bias. Third, sufficient within-study-group contrasts are often lacking. These problems are discussed in interpreting recent cancer studies of diet, and recommendations are made for future research.

Diet↗