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Biomedical subjects

D A Ferguson

Publications and source records attributed to D A Ferguson.

At least 55 records · Page 3Linked to original sources
PubMed1987

Differentiation of Legionella species by soluble protein patterns in polyacrylamide slab gels.

Water-soluble protein extracts were obtained from representative strains of eleven species of Legionella and examined by polyacrylamide slab gel electrophoresis (PAGE). The eleven species included: L. pneumophila (serogroups 1-9), L. micdadei, L. longbeachae (serogroups 1 and 2), L. gormanii, L. dumoffii, L. bozemanii, L. jordanis, L. oakridgensis, L. wadsworthii, L. feeleii and L. maceachernii. Species identification was verified by gas-liquid chromatography of the non-hydroxy, monohydroxy and dihydroxy fatty acids. Strains within each species shared common patterns of protein banding. Each species had a distinctive protein banding pattern. Results indicate that PAGE of water soluble protein extracts is a useful technique for identification of Legionella isolates.

Bacterial Proteins↗
PubMed1986

The acute effects of ethanol on auditory event-related potentials.

The acute effects of ethanol on the ERPs evoked by auditory stimuli were investigated using 0 g/kg, 0.3 g/kg and 0.54 g/kg ethanol dose. Ethanol was administered to 13 subjects single blind and orally in 20% v/v orange juice. Each subject received one of the three doses at three separate testing sessions. The ERPs were monitored at Cz in the 10-20 system in an odd ball paradigm. At the 0.54 g/kg ethanol level, an increase in latency was observed in the N1, P2, N2 components under both stimuli type conditions. The latency and amplitude of the P3 component were affected by ethanol at both dose levels. The amplitude of P3 was reduced and the latency increased in a dose-dependent manner. These characteristics of the P3 were observed under the target stimuli condition. The findings of the study suggested that stimulus attention, as reflected by N1 amplitude, was affected at the moderate ethanol dose level while stimulus categorisation, as reflected by P3 latency, was affected at the low ethanol dose level, with increased effects at the moderate dose level.

Adult↗
PubMed1986

Systolic blood pressure in relation to occupation and perceived work stress.

This paper outlines the methods used in a five-year prospective study of 4,607 Australian government employees and presents initial cross-sectional results examining associations between systolic blood pressure, occupation, and subjects' perceptions of work stress as ascertained in a questionnaire survey. The questionnaire items were grouped by means of principal component analysis into six factors representing adverse job characteristics. There were appreciable occupational differences in the mean scores for all six factors and in systolic blood pressure. The differences in systolic blood pressure among men from different occupational categories could not be explained by variation in the level of occupational stress perceived and reported by the subjects. Age, occupation, body mass index, and level of perceived stress arising from financial problems were significantly associated with systolic blood pressure level. A multiple linear regression model was used to determine the relationship between systolic blood pressure, age, and occupation after adjustment for the effects of the other variables.

Blood Pressure↗
PubMed1984

Differentiation of Campylobacter species by protein banding patterns in polyacrylamide slab gels.

Soluble protein extracts of 37 catalase-positive strains of Campylobacter species were examined by polyacrylamide slab gel electrophoresis (PAGE). Electrophoretic banding patterns showed good correlation with biochemical tests and with available DNA homology data in distinguishing species of Campylobacter but did not differentiate subspecies or biotypes. PAGE patterns indicated that Campylobacter coli is a distinct species. Furthermore, the PAGE patterns indicated that C. jejuni and nalidixic acid-resistant thermophilic Campylobacter species (C. laridis) are each distinct species. The protein banding patterns of C. fetus subsp. venerealis and C. fetus subsp. fetus strains were distinctly different from those of the three thermophilic species.

Bacterial Proteins↗
PubMed1982

Occupational stress and hypertension.

The Department of Occupational and Environmental Health in the Commonwealth Institute of Health and the University of Sydney has since 1977 been conducting a study of possible occupational factors in hypertension and in other precursors of coronary heart disease. The study arose out of claims by public service employees that the stress of their work was inducing these diseases. The study has two additional aims: prospective observation of progression of hypertension and associated cardiovascular risk variables in relation to evolving occupational conditions; and a trial of non-pharmacological modification of mild hypertension and associated variables through intervention by occupational nurses. A total of 4607 subject drawn from telecommunications and taxation offices in Sydney underwent medical screening before allocation, according to risk, into intervention and reference groups. Data acquisition included self-administration of two questionnaires, on personal, social, occupational and medical history, and on reaction to potential work stresses and to recent life events. Response to questions related to the coronary prone behaviour pattern was tested in a sub-set of the population against rating of the pattern by Rosenman and Friedman's interview method. The paper reports on method and preliminary description of the population.

Adult↗
PubMed1981

Sickness absence, respiratory impairment and smoking in industry: an australian study.

A retrospective study of sickness absence, respiratory impairment and their relation to smoking habits was conducted among a heterogeneous population of 1867 staff members of 12 Australian organizations. Data on smoking habits were used to divide the sample into current cigarette smokers (n=392), ex-cigarette smokers (n=182) and those who had never smoked (n=714). Results of the health survey by self-administered questionnaire showed that the prevalence of respiratory symptoms was higher in cigarette smokers than in non-smokers both in men and women. Smoking was particularly related to frequency of cough, and sputum production. Wheezing showed a similar, though less marked, trend. The influence of smoking on the pulmonary function value, FEV1/FVC% was assessed in a group of 972 men and 297 women. Results of analysis of variance showed that ventilatory function was significantly impaired among smokers and ex-smokers. The sickness absence records of 826 cigarette smokers, ex-smokers and non-smokers were also compared. Both frequency and duration of sickness absence were greater in cigarette smokers and ex-smokers. Significant differences between these groups were confirmed in total as well as in certified absence. Among males, the average number of days off work was 1.59 times greater in male smokers than in male non-smokers, and 1.36 times greater for female subjects who smoked. The epidemiological implications of such findings await further research. However, the consequences for the individual, industry and the general community are apparent.

Absenteeism↗
PubMed1981

Campylobacter fetus ssp jejuni: isolation from patients with gastroenteritis.

Within a seven-month period, Campylobacter fetus ssp jejuni was isolated in East Tennessee from 18 patients with gastroenteritis; 83% of these patients had bloody diarrhea. Absence of other enteric organisms such as Salmonella, Shigella, and Yersinia implicated C fetus ssp jejuni as the causative agent. A fourfold increase in titer by tube agglutination from four of eight patients studied supported the pathogenicity of this organism. Treatment with erythromycin alleviated gastroenteritis symptoms within 24 to 48 hours, with concurrent disappearance of the organism from the feces. An isolation rate of 8% in our patients indicates that C fetus ssp jejuni is more common as a cause of human diarrhea than Salmonella or Shigella. The severity of the C fetus ssp jejuni gastroenteritis poses a possible reclassification from diarrhea or gastroenteritis to acute dysentery syndrome.

Adult↗
PubMed1978

Electrophoretic protein patterns and enzyme mobilities in anaerobic coryneforms.

The soluble protein patterns and electrophoretic mobilities of malate and succinate dehydrogenases and catalase have been examined in 25 strains of Propionibacterium acnes, P. granulosum, and P. avidum. A distinctive protein pattern for each species was found, and it was possible also to distinguish the serotypes within P. acnes and P. avidum. Strains of P. acnes, P. granulosum, and P. avidum could be differentiated by the mobilities of their malate dehydrogenases. Catalase activity was detected in the soluble fractions of all strains. Catalases from P. acnes and P. avidum strains had the same mobility, whereas that from P. granulosum was slightly slower. Under the conditions used, succinate dehydrogenase activity could be detected, but the patterns were not distinctive.

Anaerobiosis↗
PubMed1978

Nutritional requirements of anaerobic coryneforms.

The nutritional requirements of three species of anaerobic coryneforms and their serotypes (Propionibacterium acnes types I and II, P. avidum types I and II, and P. granulosum) were determined. Strains of P. avidum would consistently grow to a transmittance of 1 to 3% at 560 nm in a basal salts medium supplemented with glucose, pantothenate, biotin, thiamine, and 12 amino acids (alanine, arginine, cysteine, glutamine, glycine, histidine, isoleucine, methionine, phenylalanine, serine, tyrosine, and tryptophan). Strains of P. acnes and P. granulosum, however, failed to grow in this medium unless six additional amino acids were present (asparagine, leucine, lysine, proline, threonine, and valine). All three species grew equally well whether the 18 amino acids were supplied in the form of a casein hydrolysate supplemented with tryptophan or were added separately. Nicotinamide enhanced growth of P. acnes but had no effect on growth of P. avidum and P. granulosum. Other nutrients which were not absolute requirements, but which significantly improved growth of these species, included the purines guanine and/or adenine, Tween 80, which served as a source of oleic acid, sodium L-lactate, alpha-ketoglutarate, and pyruvate. Strains (86) comprising all five groups grew well in the defined medium, except four strains of P. acnes type II (29 tested), which failed to grow unless heme and vitamin K were added to the medium. One strain of P. granulosum (22 tested) failed to grow in any defined medium, suggesting an additional growth factor requirement.

Amino Acids↗
PubMed1975

Effects on specific antibodies on the catalytic activity of L-asparaginase from Serratia marcescens and Escherichia coli.

Rabbit antisera against highly purified L-asparaginase from Serratia marcescens and from Escherichia coli showed up to 60% inhibition of the catalytic amidohydrolysis of L-asparagine when combined with the homologous enzyme. This inhibition was diminished somewhat against the heterologous enzyme. Kinetic studies in the presence of these antisera showed an increased Kmapp for both homologous and heterologous enzymes using L-asparagine as substrate. In contrast, kinetic studies employing the poor substrate, L-glutamine, showed activation attributable to specific antibodies. This was seen in lower Kmapp values and up to twofold increases in the Vmax over the normal rabbit serum controls. The high degree of cross-inhibition (approximately 80%) and the low degree of cross-reactivity in the quantitative precipitin test (approximately 34%) suggest that these two enzymes possess structural similarities located mainly in the regions of the catalytic sites.

Animals↗
PubMed1974

Vision at work visual defect and the visual demand of tasks.

Several related studies of visual tasks in a large communications undertaking have revealed much defect of vision and many sources of visual fatigue and inefficiency. The nature of visual fatigue is described briefly and a programme to facilitate visual tasks is outlined.

Journal Article↗
PubMed1971

Immunochemical comparison of L-asparaginases from Serratia marcescens and Escherichia coli.

Immunochemical properties of l-asparaginases from Serratia marcescens and Escherichia coli were compared by means of quantitative precipitin reactions and quantitative microcomplement-fixation reactions employing homologous and heterologous antisera. The enzyme preparations used in these tests produced one arc of precipitate upon immunoelectrophoresis. According to our results with the precipitin and micro-complement fixation reactions, both enzymes are related immunochemically. On the basis of these tests, distinct structural differences exist between the two enzymes. From results with the micro-complement fixation test, we estimated that the two enzymes could differ by 10 to 15 amino acid residues.

Ammonia↗