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Biomedical subjects

J Johnson

Publications and source records attributed to J Johnson.

At least 415 records · Page 23Linked to original sources
PubMed1991

Effect of training on VO2max, thigh strength, and muscle morphology in septuagenarian women.

The purpose of this study was to determine the effects of a long-term (50 wk) combined aerobic-resistance training program on maximal oxygen consumption (VO2max, thigh strength, and vastus lateralis fiber morphology in healthy septuagenarian women (mean age = 72 +/- 6 yr). Subjects volunteered to be in either an exercise (Ex; N = 17) or control (Con; N = 10) group. Con subjects were 34% less active in winter than in summer, Ex subjects maintained their summer activity level on exercise days in winter. Initial, intermediate (20 wk), and final (50 wk) measurements were made for isokinetic knee extension/flexion strength; VO2max and morphological measurements from a muscle biopsy were made at the initial and final times only. Both groups gained in leg strength (Ex = +6.5%; Con = +7.8%; P less than or equal to 0.05) during the summer; in the winter the Ex group maintained leg strength and the Con group declined 12.2% (P less than or equal to 0.05). The fast-twitch muscle fiber area (Type IIb) increased 29% (P less than or equal to 0.001) in the Ex group and declined 26% (P = 0.014) in the Con group. VO2max increased only in the Ex group (16%; P less than 0.001). We conclude that healthy septuagenarian women can increase aerobic capacity, leg strength, and Type IIb muscle fiber area with a long-duration, combined aerobic-resistance exercise program.

Aged↗
PubMed1991

Determinants of acceptance of routine voluntary human immunodeficiency virus testing in an inner-city prenatal population.

Routine voluntary prenatal human immunodeficiency virus (HIV) counseling and testing offer the opportunity to encourage reduction of high-risk behaviors among uninfected women and to identify those women with asymptomatic HIV infection. To characterize the determinants of acceptance of routinely offered and encouraged HIV testing in inner-city parturients in Atlanta, we identified two groups of women, one that declined HIV testing and another that accepted testing. Each group was asked to complete a questionnaire designed to assess the effectiveness of pre-test counseling. During the 7-month study period, 4731 women registered for prenatal care and 4574 (97%) consented to HIV testing. Nearly all women stated that they were not pressured into having HIV testing performed. Women who accepted HIV testing were more likely to be young, black, and single (P less than .001) and less likely to have received education beyond high school (P less than .05). More accepters than decliners thought the HIV counseling session was valuable (97 versus 91%; P = .04); 55% of accepters agreed to antibody testing because of concern about the risk of transmitting HIV infection to their fetus or infant. More accepters than decliners indicated a willingness to have HIV testing in a future pregnancy (74 versus 33%; P less than .001). These data suggest that most inner-city parturients in our institution view routine voluntary HIV counseling as a valuable component of their prenatal care.

Adolescent↗
PubMed1991

Detection of toxoplasma-specific immunoglobulin-G: assessment of a slide agglutination test.

The performance of a slide agglutination test for detection of toxoplasma-specific IgG was assessed and compared with that of the dye test and latex agglutination test. The slide agglutination test was as sensitive as, and more specific than, latex agglutination. The predictive value of a negative slide agglutination test was less than the latex agglutination test but produced results within minutes, although quantitative results were not comparable to other assays. Slide agglutination presents a rapid alternative to the latex agglutination test as a screening assay for toxoplasmosis, although patients at risk of life-threatening infection require detailed serological examination using additional methods.

Agglutination Tests↗
PubMed1991

A dimorphic 4-bp repeat in the cystic fibrosis gene is in absolute linkage disequilibrium with the delta F508 mutation: implications for prenatal diagnosis and mutation origin.

The gene causing cystic fibrosis (CF) has been recently cloned, and the major mutation (delta F508) accounting for approximately 70% of CF chromosomes has been uncovered. We have identified at the 3' end of intron 6 in the CF gene a 4-bp tandem repeat (GATT) that exhibits interesting features. First, PCR screening of 103 normal individuals revealed that the repeat exists only in two polymorphic allelic forms, either as a hexamer or a heptamer. These two alleles are in Hardy-Weinberg equilibrium and predict a heterozygote frequency of 41% (p[seven repeats] = .71; q [six repeats] = .29). Second, the allele with six repeats was found linked to delta F508 on all 76 CF chromosomes investigated, demonstrating strong linkage disequilibrium and suggesting that delta F508 had originated on the gene bearing six repeats. Third, when the repeat alleles are linked to the DNA markers XV2c and KM19, extended haplotypes are generated. These new haplotypes become informative in situations in which prenatal diagnosis cannot be performed solely with XV2c and KM19. Since this repeat marker is located in the CF gene and would be very less likely to recombine with the gene, it can serve as a valuable DNA marker for haplotype analysis. A possible crossover, however, was identified between XV2c and KM19, transferring delta F508 to a different haplotype.

Alleles↗
PubMed1991

Treatment of psoriasis with piritrexim, a lipid-soluble folate antagonist.

Methotrexate is an effective and convenient treatment for severe psoriasis whose use is limited by the development of hepatic fibrosis and cirrhosis in a small number of patients. The mechanism of hepatotoxicity is unknown, but it is believed to be the result of intracellular polyglutamation and prolonged retention of methotrexate within the cell. Piritrexim isethionate is a lipid-soluble antifolate that has a mechanism of action similar to that of methotrexate. Since it is not polyglutamated, piritrexim could be effective in the treatment of psoriasis without the associated long-term hepatotoxicity. A 12-week phase I/II clinical trial of severe chronic plaque psoriasis assessed the safety and efficacy of oral piritrexim therapy. Based on experience gained from oncologic trials, each patient received a twice-daily dosage for 5 consecutive days every 2 weeks. Dosages ranged from 25 to 100 mg twice a day. Improvement in both lesion scores and percentage of body involvement was significant at a dose of 50 mg or more twice daily. Fifteen of 19 patients who completed 12 weeks of therapy demonstrated greater than 50% improvement in lesion scores. Improvement was limited by recrudescence of lesions over the 9-day rest period. Adverse experiences were minimal and dose related. Piritrexim is efficacious in the treatment of psoriasis.

Adult↗
PubMed1991

Rock music as a medium for AIDS intervention.

As the prevalence of HIV infection among adolescents increases, public health workers continue to seek media for intervention. An interview-based study conducted with a large sample of adolescent intravenous drug users (AIVDUs) by the National AIDS Demonstration and Research Project in Houston, Texas has located two ways in which rock music has potential value as a vehicle for AIDS intervention. First, as a topic of conversation, rock music can serve to rejuvenate the interview and retrieve the respondent's attention. Second, as a primary source of everyday life meaning for AIVDUs, rock music can serve as a medium for transmitting preventive care messages. Suggestions for the implementation of the latter are presented.

Acquired Immunodeficiency Syndrome↗
PubMed1991

Classroom health promotion.

School nurses must broaden their role as health educators and promoters if they are to develop as the key figure in the school health service, argues Julie Johnson. Here she describes her own project to work alongside teachers in class as part of her schools' health education programmes. Time spent in class is more than repaid by improved attendance at medicals and better relations with children, parents and teachers, she believes.

Child↗
PubMed1990

Smoking, smoking cessation, and major depression.

A relationship between cigarette smoking and major depressive disorder was suggested in previous work involving nonrandomly selected samples. We conducted a test of this association, employing population-based data (n = 3213) collected between 1980 and 1983 in the St Louis Epidemiologic Catchment Area Survey of the National Institute of Mental Health. A history of regular smoking was observed more frequently among individuals who had experienced major depressive disorder at some time in their lives than among individuals who had never experienced major depression or among individuals with no psychiatric diagnosis. Smokers with major depression were also less successful at their attempts to quit than were either of the comparison groups. Gender differences in rates of smoking and of smoking cessation observed in the larger population were not evident among the depressed group. Furthermore, the association between cigarette smoking and major depression was not ubiquitous across all psychiatric diagnoses. Other data are cited indicating that when individuals with a history of depression stop smoking, depressive symptoms and, in some cases, serious major depression may ensue.

Adolescent↗
PubMed1990

The effect of four chemical forms of selenium on mammary tumor incidence in BALB/c female mice treated with 7-12-dimethylbenz[a]anthracene.

The study was conducted to determine the effect of four forms of selenium on inhibition of DMBA-induced mammary tumors. BALB/c virgin female mice were fed the AIN-76 diet containing 0.2 or 2.0 ppm Se as selenite, selenate, selenomethionine, or selenocystine prior to and for 6 months post DMBA-treatment. At necropsy, mammary glands were histologically treated for confirmation of adenocarcinomas and the livers were removed for analysis of glutathione-peroxidase (GSHPx) activity and selenium concentrations. Dietary levels or forms of selenium had no effect on body weights. Inorganic selenium fed at 2.0 ppm Se (selenite and selenate) decreased mammary tumor incidence, but organic selenium (selenomethionine and selenocystine) had no effect on mammary tumor incidence. Hepatic GSHPx activity was highest with the 2.0 ppm selenium as selenocystine diet, but hepatic selenium levels were highest with the 2.0 ppm selenium as selenite. This study showed that the dietary form of selenium affects inhibition of mammary tumorigenesis. Furthermore, the study suggested that the pathways for selenium incorporation into GSHPx and for tumor inhibition are different.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1990

Uncommon troubles in young people: prevalence estimates of selected psychiatric disorders in a nonreferred adolescent population.

A two-stage epidemiologic strategy was used to estimate the lifetime prevalence of selected DSM-III-defined psychiatric disorders in a county-wide secondary school population (N = 5596). Screening tests used in the first stage included items based on DSM-III criteria for eating disorders and panic disorder, as well as the Leyton Obsessional Inventory-Child Version and the Beck Depression Inventory. Based on interviews (n = 356) by clinicians in the second stage, the lifetime prevalence of anorexia nervosa was 0.2%; bulimia, 2.5%; panic disorder, 0.6%; obsessive-compulsive disorder, 1.9%; major depression, 4.0%; dysthymic disorder, 4.9%; and generalized anxiety disorder, 3.7%. While rates of mental health service utilization varied greatly by diagnosis, only 41% of students who were assigned both a diagnosis and a rating of impairment had received any kind of clinical attention.

Adolescent↗
PubMed1990

Panic disorder, comorbidity, and suicide attempts.

In a previous report, we demonstrated a strong association between panic disorder and suicide attempts based on data from the Epidemiologic Catchment Area study (a probability sample of more than 18,000 adults living in five US communities). In these analyses, although we controlled statistically for comorbidity of panic disorder with other psychiatric disorders, we did not directly estimate the risk of suicide attempts in persons with uncomplicated panic disorder (ie, without any other Axis I disorders) compared with those with comorbid conditions. Persons with uncomplicated panic disorder represent fewer than a third of persons with panic disorder. However, the lifetime rates of suicide attempts in persons with uncomplicated panic disorder (7%) were consistently higher than for persons with no psychiatric disorder (1%). Similar findings on the rate of suicide attempts in persons with uncomplicated major depression (7.9%) emerged. We conclude that suicide attempts are associated with panic disorder in its uncomplicated or its comorbid form and that the risks are comparable with those of major depression, comorbid and uncomplicated. These epidemiologic findings are discussed within a clinical perspective to explain why these associations may not appear obvious in clinical practice.

Adolescent↗
PubMed1990

Effects of methyldopa on psychometric performance.

Double-blind, crossover comparisons of methyldopa with placebo were performed in 16 patients with mild to moderate hypertension. Methyldopa (250 mg tid) for 14 days significantly reduced blood pressure, impaired card-sorting time and digital symbol substitution score, and caused trends for impairment of other psychometric tests. Effects of practice were greater than those of treatment on all tests other than card sorting, although no interaction between treatment and practice was seen. Continued dosage impairs psychometric performance, but practice effect is a major confounder. Simple crossover studies are inadequate for detecting moderate drug effects on intellectual performance.

Adult↗
PubMed1990

The impact of school emotional climate on student psychopathology.

Reports of differences among schools in emotional and social climate were related to changes in behavioral and emotional problems and alcohol use in students who remained in these schools over a 2-year interval. Four dimensions of school climate were examined. School conflict and social facilitation were shown to be related to increases in childhood psychopathology, whereas student autonomy was not. Effects of academic focus were even stronger than those of conflict, in the sense of being independently related to more syndromes. School climate effects were examined for conditionality on student characteristics and for synergism, It was concluded that intervention to alter the school climate may promote the emotional and behavioral well-being of children and adolescents.

Achievement↗