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Biomedical subjects

H L Johnson

Publications and source records attributed to H L Johnson.

At least 19 recordsLinked to original sources
PubMed1992

Brief communication: changes in thermogenesis and caloric efficiency with high and normal protein-reducing diets in women.

A pilot study with four women (40-60% above ideal weight, 32-42 years old) was conducted for 6 weeks of weight maintenance, 12 weeks at 50% calories (1000 and 1200 kcal/day) and 6 weeks of weight maintenance after weight loss. Two women consumed 17% and two 32% of their calories from protein during restriction; their energy metabolism and body composition changes were examined. The use of doubly labeled water for measuring energy expenditure during weight loss was evaluated. Although the 32% protein diet did not reduce lean body tissue loss, the apparent increased efficiency of calorie utilization compared to the 17% protein diet is worthy of further investigation. Thermic effect of a meal was greatly reduced in these women compared to previously reported responses. Further refinements of the doubly labeled water method are needed prior to application in weight loss studies.

Adult↗
PubMed1992

Predicting total body water and extracellular fluid volumes from bioelectrical measurements of the human body.

Two biological impedance analyzers, a 50 kHz (RJL) and 20-100 kHz (BMA) instrument, and a total body electrical conductivity (TOBEC) instrument were used to estimate total body water (TBW), extracellular (ECF) and intracellular (ICF) fluid volumes by repeated measurements of 16 normal men (19-38 years old) to assess which, if any, would provide the best estimates. At 3-week intervals, TBW was determined by deuterium dilution, ECF by bromide dilution, ICF by difference (TBW-ECF) and lean body mass by density. Prediction equations were obtained by regression; predicted values for the body fluid volumes were calculated and the results were statistically evaluated. Both the TOBEC and the BMA provided rapid and reliable estimates for body fluid volumes with standard errors of the estimates of about 0.5-1.1 L for ECF, 1.0-1.8 L for TBW, and 1.0-1.3 L for ICF. Part of the error was attributable to standard tracer-dilution methods.

Adult↗
PubMed1992

Psychiatric mental health consultation and nursing in the United Arab Emirates.

1. Our "mission" was preparing psychiatric services for the anticipated high number of allied casualties; providing clinical, educational, and developmental support to the host nation; and maintaining diplomatic relations within the hospital and surrounding community. 2. Because of cultural differences, the hospital staff were uneasy about some of the inservice classes. US staff were taught the importance of refusing to succumb to "the illusion of color blindness." 3. With the support of the host, we took leadership in receiving and training the casualties of the war. Psychiatric services were provided to allied troops as well as the citizens of Dubai.

Cross-Cultural Comparison↗
PubMed1990

Effects of prenatal methadone exposure on sex-dimorphic behavior in early school-age children.

Prenatal opiate exposure has been shown to alter the pattern of sex-dimorphic behavior in male and female rats. To conduct an exploratory study of opiate effects in humans, we compared the sex-dimorphic behavior of male and female offspring of women maintained on methadone during pregnancy to that of demographically matched control subjects. Standardized questionnaires completed by the primary caretakers served as assessment instruments. The six- to eight-year-old methadone-exposed boys showed more stereotypically feminine behavior than nonexposed male control subjects. There were no significant differences between methadone-exposed girls and their female control group. Based on these preliminary findings, we recommend that future follow-up studies of opiate-exposed children be broadened to include an assessment of their gender role behavior.

Child↗
PubMed1990

Mother-infant interaction in a multirisk population.

The relationship among maternal and observer ratings of infant temperament, observer ratings of maternal responsiveness, and maternal drug abuse habits, was studied in a population facing multiple risk factors. Intensity of maternal drug abuse was found to be negatively related to maternal ratings of infant temperament, and ratings of temperament were positively related to maternal responsiveness. Implications for research and practice are explored.

Alcoholism↗
PubMed1990

Resilient children: individual differences in developmental outcome of children born to drug abusers.

Since 1977, we have been following the neurobehavioral development of two groups of children: a group born to women on methadone maintenance and a drug-free comparison group. This study used the data on the children evaluated at 36 months of age to determine whether distinct patterns of developmental outcome can be identified, and which medical, familial, or environmental characteristics are associated with developmental differences. The children were clustered on four measures at 36 months: head circumference percentile, Merrill-Palmer Scale score, neurological evaluation, and referrals for developmental problems. Three distinct clusters emerged, with methadone children disproportionately frequent in Cluster 3, the group showing the poorest development. Comparisons of the clusters on a wide range of variables revealed consistent differences between Cluster 1 and Cluster 3 children in maternal responsiveness and incidence of neglect and family violence. These findings indicate that distinct developmental patterns do occur within this predominantly lower-class ghetto population; further, that children born to methadone-maintained women are more likely to show poor development. However, when the environment provides nurturance and stability, methadone children can show resilience and develop well.

Child, Preschool↗
PubMed1989

Ascorbic acid and erythorbic acid metabolism in nonpregnant women.

Ascorbic acid (AA) metabolism and requirements were studied in 11 adult nonpregnant women maintained in a metabolic unit and fed a formula diet devoid of AA for 54 d. After depletion for 24 d, the subjects received increasing supplements of AA in the presence or absence of 600 mg/d of erythorbic acid (EA). Various analytical procedures were used to measure AA concentrations in blood components. The depletion period resulted in a marked decrease in AA in all blood indices. During the study scorbutic signs developed in some of the subjects. AA supplements of 30 mg/d for 10 d failed to increase plasma ascorbate concentrations; 60 mg/d for 10 d produced a small increase; 90 mg/d resulted in a mean AA concentration of 29 mumol/L. EA did not present any adverse effects, but rather had a small sparing effect. Vitamin C requirements for adult nonsmoking, nonpregnant women would be marginally met by an intake of 60 mg/d of AA whereas 90 mg/d would provide an allowance for body storage.

Adult↗
PubMed1988

Effects of electrolyte and nutrient solutions on performance and metabolic balance.

Three commercial sport drinks, solutions of their individual minerals and glucose, and water were used to maintain water balances in six men during 4 h of physical activity in a 35 degrees C room. Each solution was provided for 5 consecutive days to each man during the 12-wk study. Complete mineral and water balances (including sweat losses) were conducted. Oxygen consumption and carbon dioxide production were measured during two levels of sub-maximal and during a maximal treadmill performance test. All of the solutions, including water, were equally effective in maintaining water and mineral balances, and moderate physical performance while the men were consuming an adequate all liquid diet. All of the solutions containing carbohydrates increased respiratory exchange ratios. These increases were significant during maximal performance for only two of the commercial products. These two products also produced the higher values for most of the performance evaluations, although they were not generally significantly different from values obtained while other solutions or water were consumed. The major benefit of these commercial sport drinks are their prevention of hypohydration due to an increase in voluntary fluid intakes.

Adult↗
PubMed1987

Folate requirement and metabolism in nonpregnant women.

Folate metabolism and requirements were studied in 10 adult nonpregnant women maintained for 92 d in a metabolic unit. After a folate depletion period of 28 d, the subjects received increasing supplements of folate from food items or as pteroylmonoglutamic acid (PGA). Plasma folate levels fell 60% during the depletion period and continued to fall until 200 micrograms/d of naturally occurring food folates were provided. Supplements of 300 micrograms/d of naturally occurring folates produced a small rise in plasma folate levels although erythrocyte folate levels continued to fall. Lymphocyte deoxyuridine suppression, neutrophil hypersegmentation, and other measurements related to folate metabolism were performed. When compared with PGA, dietary folates appeared to be no more than 50% available. A daily intake of 200-250 micrograms of dietary folates appears to meet the folate requirements of nonpregnant adult women whereas an intake of 300 micrograms/d provides an allowance for storage.

Adult↗
PubMed1985

Black mental health client's preference for therapists: a new look at an old issue.

Thirty black clients from a community mental health center in the Los Angeles City were interviewed to determine whether black Clients prefer black therapists or therapists from other ethnic backgrounds, and the factors associated with their preferences. Both quantitative and qualitative analyses were employed. The results indicated that 60% of the respondents preferred black therapists. With the small sample size this difference between responders and non-responders was within the normal range expected. However, preference of blacks for blacks is an important finding. When a black client preferred a black therapist, the major reasons depended on the therapist's professional competence and attitudes, not just the cultural, race, and linguistic compatibility.

Black or African American↗
PubMed1985

Methadone-maintained mothers: 3-year follow-up of parental functioning.

A group of 57 methadone-maintained mothers and 31 matched drug-free controls were compared on their ability to provide adequate child care, capacity for satisfying interpersonal relationships, and motivation for self-improvement. Results indicate that, as a group, methadone mothers require more assistance in parenting, are more socially isolated, and are less likely to pursue vocational and educational activities. The interpersonal and environmental impact of poor parenting further compounds the effects of in utero exposure to methadone, placing these infants at high risk.

Child Development↗
PubMed1978

Analgesics. 1. Synthesis and analgesic properties of N-sec-alkyl- and N-tert-alkylnormorphines.

A series of N-sec- and N-tert-alkylnormorphines was synthesized and evaluated for analgesic potency, antagonist activity, and opiate receptor binding. Computer-assisted conformational analysis profiles were utilized to assist in the selection of compounds for synthesis and correlation of receptor events with in vivo observations. N-tert-Alkylnormorphines 5a-c were devoid of agonist activity; however, some sec-alkyl analogues showed interesting mixed agonist-antagnoist actions. N-sec-Butyl- and N-(alpha-methylally)normorphine were separated into R and S isomers, which exhibited quantitative pharmacological differences. The N-sec-butyl S isomer 10a showed analgesia approximating morphine with nalorphine-like antagonist activity. Preliminary testing indicates only slight evidence for physical dependence with this compound.

Analgesics↗
PubMed1977

Application of 13C-NMR spectroscopy to in vitro analysis of enzyme kinetics.

The conversion of D,L-alpha-13C-histidine to similarly labeled alpha-13C histamine by bacterial and mammalian histidine decarboxylase was studied by 13C-NMR spectroscopy and GLC-mass spectrometry. The results obtained with the partially purified bacterial enzyme were in essentially perfect agreement with results obtained simultaneously with a standard radioisotopic method using carboxyl-labeled-14C-L-histidine. For a crude tissue preparation of the mammalian enzyme, the radioisotopic method indicated an activity three times that based on 13C-NMR measurement of alpha-13C-histamine. The difference in results was accountable in terms of additional 13C-NMR signals attributable to products other than histamine due in part to enzymatic degradation of the latter.

Animals↗
PubMed1977

Potential histidine decarboxylase inhibitors. 1. alpha- and beta-substituted histidine analogues.

Histidine analogues with alkyl substitution at Calpha and Cbeta were prepared as potential inhibitors of specific histidine decarboxylase. Activity was assessed in vitro using extracts of rat pyloric stomach and a radioisotopic assay of 14CO2 evolved from carboxyl-14C-labeled histidine. alpha-Substituted analogues (C2-C4) including 2-hydroxyethyl were less potent than alpha-methylhistidine; the alpha-n-butyl analogue was completely inactive at 10(-3) M. Similarly, beta,beta-dimethylhistidine and homohistidine failed to exhibit activity at 10(-3) M.

Animals↗