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Biomedical subjects

J Gibson

Publications and source records attributed to J Gibson.

At least 307 records · Page 17Linked to original sources
PubMed1980

Enzyme-linked immunosorbent assay (ELISA): a study of antibodies to Mycobacterium tuberculosis in the IgG, IgA and IgM classes in tuberculosis, sarcoidosis and Crohn's disease.

Enzyme-linked immunosorbent assay (ELISA) has been used to study the levels of antibody binding to the soluble antigens of Mycobacterium tuberculosis (BCG) in the IgG, IgM and IgA classes in sera from patients with tuberculosis, sarcoidosis and Crohn's disease. Of the patients with tuberculosis, 75% had significantly elevated levels of anti-M. tuberculosis antibodies in the IgG class. The levels of antibodies in the IgM and IgA classes were much less discriminative. Many of the patients with sarcoidosis and Crohn's disease had significantly elevated levels of antimycobacterial antibodies, principally in the IgM and IgA classes. These elevated levels of antibody were not related to the total levels of the immunoglobulin classes. For the purpose of serodiagnosis, an estimation of the antimycobacterial antibodies in the IgG class gives the most discriminative results.

Adult↗
PubMed1980

The specificity of the humoral immune response to soluble mycobacterial antigens in tuberculosis.

A high proportion of patient with tuberculosis have been shown to produce significant levels of antibodies to antigens unique to Mycobacterium tuberculosis, antigens restricted to the slowly growing mycobacteria and antigens common to all species in the genus. About 20% of patients with this disease do not have significantly elevated levels of antibodies to any of these groups of antigens. Consequently, the availability of highly purified soluble antigens specific for M. tuberculosis would not permit more cases of tuberculosis to be diagnosed serologically.

Adult↗
PubMed1980

Pituitary and testicular fibrosis in association with retroperitoneal fibrosis.

A patient is discussed who originally presented with retroperitoneal fibrosis, and subsequently developed both pituitary fibrosis and testicular fibrosis. Replacement of testicular tissue by fibrosis has not previously been described in this condition, while we have only been able to find a single previous report of pituitary fibrosis. Fibrous replacement of testis and pituitary should be considered as a further manifestation of the midline fibrosing syndrome.

Adult↗
PubMed1980

1,2-Dichloropropane: metabolism and fate in the rat.

1. The metabolism of 1,2-dichloropropane in the rat has been investigated. The major urinary metabolite has been isolated and identified as N-acetyl-S-(2-hydroxypropyl)cysteine. Two minor metabolites of 1,2-dichloropropane have been identified as beta-chlorolactate and N-acetyl-S-(2,3-dihydroxypropyl)cysteine. 2. The fate of 1-chloro-2-hydroxypropane, a proposed intermediate metabolite of 1,2-dichloropropane, has been investigated. Apart from its known urinary metabolite, N-acetyl-S-(2-hydroxypropyl)cysteine, two oxidative metabolites were detected. These were identified as beta-chlorolactaldehyde and beta-chlorolactate. 3. A pathway is proposed for the metabolism and fate of 1,2-dichloropropane in the rat. This accounts for previous observations made for the fate of radioactivity from administration of 1,2-dichloro[1-14C]propane. 4. The microbial and mammalian metabolism of several halogen-containing foreign compounds is discussed.

Acetylcysteine↗
PubMed1979

Lung function in an Australian population: 2. Spirometric performance and cigarette-smoking habits.

The FEV1, FVC and FEV1/FVC% in 12016 females and 18 359 males were related to cigarette-smoking habits. Over all, non-smokers had significantly better lung function than cigarette smokers. Ex-smokers of either sex had significantly higher FEV1 and FEV1/FVC% than cigarette smokers, but the FVC values were higher only in females. With consumption in excess of 10 cigarettes per day, deterioration in lung function was manifest in both sexes, but was greater in males than females. The mean chronological age of males who smoked from 30 to 50 cigarettes per day was 12.9 years and 9.6 years less than would have been predicted on the basis of their FEV1 and FVC values respectively. The corresponding values in women were 9.3 years and 7.9 years respectively. Additionally, the deterioration in lung function with increasing age was greater in cigarette smokers than in non-smokers.

Adolescent↗
PubMed1979

Lung function in an Australian population: 1. Spirometric standards for non-smoking adults.

Relationships between age, height, weight and spirometry with FEV0.5, FEV1, FVC and FEV1/FVC are described for a sample of 6275 female and 6511 male non-smoking adults living in New South Wales. Prediction equations for ventilatory function tests are derived from non-smokers and compared with other standards that are available in a population sample of 31172 subjects. It is concluded that the standards described in this paper are more appropriate for use in Australian populations. Nomograms for predicting FEV1 and FVC in females and males are provided.

Adolescent↗
PubMed1979

Regulation of phosphate accumulation in the unicellular cyanobacterium Synechococcus.

The phosphorus contents of acid-soluble pools, lipid, ribonucleic acid, and acid-insoluble polyphosphate were lowered in Synechococcus in proportion to the reduction in growth rate in phosphate-limited but not in nitrate-limited continuous culture. Phosphorus in these cell fractions was lost proportionately during progressive phosphate starvation of batch cultures. Acid-insoluble polyphosphate was always present in all cultural conditions to about 10% of total cell phosphorus and did not turn over during balanced exponential growth. Extensive polyphosphate formation occurred transiently when phosphate was given to cells which had been phosphate limited. This material was broken down after 8 h even in the presence of excess external orthophosphate, and its phosphorus was transferred into other cell fractions, notably ribonucleic acid. Phosphate uptake kinetics indicated an invariant apparent K(m) of about 0.5 muM, but V(max) was 40 to 50 times greater in cells from phosphate-limited cultures than in cells from nitrate-limited or balanced batch cultures. Over 90% of the phosphate taken up within the first 30 s at 15 degrees C was recovered as orthophosphate. The uptake process is highly specific, since neither phosphate entry nor growth was affected by a 100-fold excess of arsenate. The activity of polyphosphate synthetase in cell extracts increased at least 20-fold during phosphate starvation or in phosphate-restricted growth, but polyphosphatase activity was little changed by different growth conditions. The findings suggest that derepression of the phosphate transport and polyphosphate-synthesizing systems as well as alkaline phosphatase occurs in phosphate shortage, but that the breakdown of polyphosphate in this organism is regulated by modulation of existing enzyme activity.

Biological Transport↗
PubMed1978

Variation in amount of enzyme protein in natural populations.

Among strains of Drosophila melanogaster each derived from a single fertilized female taken from natural populations, there is variation in both alcohol dehydrogenase (ADH) activity and the amount of ADH protein. The correlation between ADH activity and number of molecules over all strains examined is 0.87 or 0.96 in late third instar larvae depending on whether the substrate is 2-propanol or ethanol. With respect to the two common electrophoretic allozymic forms, F and S, segregating in these populations, the FF strains on the whole have higher ADH activities and numbers of ADH molecules than the SS strains. Over all strains examined, enzyme extracts from FF strains have a mean catalytic efficiency per enzyme molecule higher than that of enzyme extracts from SS strains when ethanol is the substrate, and much higher when 2-propanol is the substrate. One FF strain had an ADH activity/ADH protein ratio characteristic of SS strains.

Alcohol Oxidoreductases↗
PubMed1978

The nurse practitioner as a teacher of physical examination skills.

The service role of nurse practitioners has been widely recognized (1). However, their potential as clinical instructors of physical examination skills has not been appreciated. This article details a new first-year medical school course in physical examination in which nurse practitioners are key members of the instructional team.

California↗
PubMed1978

Aggregation of antidepressant drugs in aqueous solution.

Light scattering, conductivity and pH methods have been used to examine the aggregation in aqueous solution of a series of antidepressant drugs. The drugs investigated included the hydrochlorides of amitriptyline, butriptyline, protriptyline, nortriptyline, imipramine, desipramine, clomipramine, dothiepin, dibenzepin, opipramol, iprindole, doxepin, mianserin and maprotiline. No significant association of dibenzepin, mianserin or maprotiline hydrochlorides could be detected up to their respective solubility limits. A micellar pattern of association was established for all other compounds. Critical micelle concentrations and micellar properties are reported.

Antidepressive Agents↗
PubMed1977

Drinking, smoking and drug-taking patterns in a predominantly lower socioeconomic status sample: comparison with Medicheck sample.

The drinking, smoking, and drug-taking patterns of 9829 adult members of the Australian Workers Union in Sydney are compared with data collected through the Medicheck Referral Centre. Overall, the two sets of data are very similar, but the results of this survey point to the high prevalence of heavy alcohol consumption, and of regular drug-taking in young people.

Adolescent↗