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N J Johnson

Publications and source records attributed to N J Johnson.

63 records · Page 4Linked to original sources
PubMed1980

The epidemiology of plasma high-density lipoprotein cholesterol levels. The Lipid Research Clinics Program Prevalence Study. Summary.

Correlates of high-density lipoprotein (HDL) cholesterol levels were studied in 4756 white males and females ages 20-59 years examined during a population survey conducted by 10 North American Lipid Research Clinics. Multivariable analysis was used to assess the relation of social, demographic, physical and behavioral characteristics for HDL cholesterol in each of the study populations and in subgroups defined by sex, age and gonadal hormone use. Characteristics associated with higher HDL cholesterol concentrations were a lean body habitus, not smoking, consumption of moderate amounts of alcohol, physical activity or exercise, membership in a high educational stratum, increased age and low dietary consumption of sucrose and starch. Each of these characteristics was examined in detail in its relation to HDL cholesterol concentrations in the respective chapters in this monograph; the purpose of the study reported here was to summarize the findings. When all variables were considered simultaneously in the analysis, body mass, cigarette smoking and alcohol consumption were the attributes most strongly and consistently associated with HDL cholesterol concentrations in the populations examined. These empirical findings from a cross-sectional study replicated across diverse populations were used to derive speculative estimates of the potential for modification of population levels of HDL cholesterol, consistent with hygienic intervention and lifestyle changes. The results of the study were considered in the context of the literature on determinants of HDL cholesterol.

Adolescent↗
PubMedDate not supplied

Life expectancy by employment status, income, and education in the National Longitudinal Mortality Study.

Based on data from the National Longitudinal Mortality Study for 1979-85, life expectancies are estimated for white men and white women by education, by family income, and by employment status. Life expectancy varies directly with amount of schooling and with family income. Differences in life expectancy at age 25 between the highest and the lowest levels of education completed were about 6 years for white men and about 5 years for white women. For family income, differences between the highest and the lowest income groups were about 10 years for white men and 4.3 years for white women. The largest differences in life expectancy were between employment categories. At age 25, white men in the labor force lived on average about 12 more years than those not in the labor force, and white women lived on average about 9 more years. For those who were unable to work compared with those in the labor force, the difference for white men was about 20 years; for white women, 29 years. Results in this study showed much the same differentials in life expectancy for education as the earlier Kitagawa-Hauser study.

Adult↗
PubMedDate not supplied

Mutual kinetic interaction between 5-fluorouracil and bromodeoxyuridine or iododeoxyuridine in dogs.

The pharmacokinetics of 5-fluorouracil (FUra) were studied alone and in the presence of either bromodeoxyuridine (BrdUrd) or iododeoxyuridine (IdUrd) in five mixed breed hounds. FUra was administered intravenously over 1 min as a 5 mg/kg dose in all three treatments. BrdUrd or IdUrd was infused intravenously at 2.5 mg/hr.kg x 6 hr and FUra was given 3 hr into the 6-hr infusion of thymidine analog. Serial blood samples were obtained for 3 hr prior to and after FUra dosing. Plasma concentrations of FUra, BrdUrd and bromouracil (BrUra), and IdUrd and iodouracil (IUra) were measured by reversed-phase HPLC. Concomitant administration of BrdUrd or IdUrd resulted in substantial changes in the kinetics of FUra. In particular, the total plasma clearance of FUra was decreased and area under the plasma concentration-time curve was increased. There were also significant changes in the volume of distribution steady-state, and in the mean residence time and half-life of FUra. The data show that FUra had little or no effect on the disposition of BrdUrd or IdUrd. In contrast, FUra had a significant effect on the disposition of BrUra and IUra going to form catabolic products. The observed pharmacokinetic interaction in dogs is probably due to a competition between BrUra (or IUra) and FUra for the rate-limiting catabolic enzyme, dihydropyrimidine dehydrogenase. This kinetic interaction was mutual and of a smaller magnitude for FUra + BrdUrd than for FUra + IdUrd.

Animals↗