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Biomedical subjects

D A Thompson

Publications and source records attributed to D A Thompson.

At least 163 records · Page 9Linked to original sources
PubMed1980

Flameless atomic absorption spectroscopy of plasma chromium.

A flameless atomic absorption spectroscopy method has been developed for the measurement of chromium. Background correction has been modified by recording non-atomic absorption separately from atomic absorption on a double-pen recorder. This was achieved by using the prime spectral line of uranium (358.5 nm, within 0.6 nm of that of chromium--357.9 nm) and was possible only because of the absence of uranium from the plasma samples. Masking of the analytical signal at atomisation by non-atomic absorption was thus eliminated and gave the method a sensitivity of 3 pg and a detection limit of 150 pg/ml. Postprandrial plasma chromium values were measured in 32 insulin-treated diabetics (1.65 +/- 0.15 ng/ml), in 53 non-insulin treated diabetics (2.0 +/- 0.16 ng/ml), and in 144 control non-diabetics (2.00 +/- 0.14 ng/ml). The difference between the mean plasma chromium level of the insulin-treated diabetics and both the non-insulin treated diabetics and the control groups was statistically significant (P < 0.05).

Adolescent↗
PubMed1979

Inability of passively acquired antibody to protect lambs against experimental pasteurellosis.

An experimental model of pneumonic pasteurellosis in sheep was used to investigate the role of serum antibody in resistance to this disease. Lambs which had been vaccinated with a sodium salicylate extract of Pasteurella haemolytica type A1 were protected against challenge with PI3 virus followed by P. haemolytica type A1 7 days later. The majority of untreated lambs and lambs which had received either 200 ml of antiserum to P. haemolytica or 200 ml of control serum intraperitoneally 18 h before infection with P. haemolytica type A1 succumbed to the challenge. Lymphocytes from vaccinated lambs showed a specific proliferative response when exposed to P. haemolytica type A1 sodium salicylate extract, and this response increased after exposure of these animals to P. haemolytica type A1 in aerosol. The results indicate that the humoral immune response alone is incapable of affording protection against experimental pasteurellosis and that cell-mediated immunity may play an important part in resistance to this disease.

Animals↗
PubMed1979

An evaluation of the mini-Wright peak flow meter.

The mini-Wright peak flow meter (MPFM) has been evaluated, and the results obtained from it show a strong positive correlation (r=0.970) with the Wright's peak flow meter (PFM). MPFM measurements, however, were biased to be about 38 1/min higher than PFM measurements (95% confidence limits 31.01/min to 45.01/min). Between instrument variation was found (F--ratio 3.67 with 9 and 81 degrees of freedom: P less than 0.001). In practice this did not appreciably affect individual measurements greatly as 95% confidence limits on any individual measurements were increased from +/-24 1/min to +/-27 1/min. There was no significant day-to-day variability in measurements obtained with individual instruments. The MPFM is a pocket-sized, simple, cheap, and robust instrument for following changes in ventilatory function. In clinical trails and surveys, however, both the bias in favour of the MPFM compared to the PFM and inter-machine variation must be taken into account. As the manufacturers have altered the scale to remove the bias since this study was performed, it will be important to know whether the original or the modified meter is being used in future studies.

Evaluation Studies as Topic↗
PubMed1979

A serological comparison of Pasteurella haemolytica vaccines containing different adjuvants.

Five adjuvants were compared for their ability to enhance the serological response of sheep to capsule extract of Pasteurella haemolytica biotype A serotype 6. Vaccines of this antigen were inoculated with incomplete Freund's adjuvant, complete Freund's adjuvant, incomplete Freund's adjuvant containing a water soluble extract of Mycobacterium tuberculosis, aluminium hydroxide gel or a combination of aluminium hydroxide gel and incomplete Freund's adjuvant. This latter vaccine induced significantly higher titres of antibody as measured by an indirect haemagglutination test than did any of the other vaccines. The aluminium hydroxide gel alone was shown to be the poorest adjuvant. The local reactions at the sites of inoculations produced by the aluminium hydroxide gel in incomplete Freund's adjuvant vaccine were not severe and were not detectable beyond one month after vaccination in the majority of the sheep.

Adjuvants, Immunologic↗
PubMed1977

Hunger in humans induced by 2-deoxy-D-glucose: glucoprivic control of taste preference and food intake.

Intracellular glucopenia induced by 2-deoxy-D-glucose (2DG) administration in man produces increased hunger ratings and magnitude estimates of pleasantness for sucrose solutions. Augmented food intake substantiates these changes in affective behavior and relieves experimentally induced hunger. Intracellular glucopenia activates counterregulatory mechanisms to raise plasma glucose concentrations. Inducing hunger experimentally with 2DG provides a useful method for studying appetitive behavior in humans. The neurohumoral control of pituitary hormone release and other hypothalamic functions may be examined after 2DG infusion.

Adult↗
PubMed1977

Changes in hospital antibiotic therapy after a quality-of-use study.

During the first quarters of 1976 and 1977, the use of parenteral gentamicin, cloxacillin, ampicillin, and cephalothin was surveyed in 219 (in 1976) and 240 (in 1977) patients admitted to a surgical, a gynaecological, and a medical ward of a teaching hospital. In 1976, therapy was assessed as irrational in 42%, 50%, and 12% of the surgical, gynaecological, and medical patients, respectively; the corresponding figures for 1977 were 24%, 25%, and 22%. The more rational therapy in 1977 was due to a shorter duration of prophylactic therapy; and to fewer patients receiving oral antibiotics just before or after the parenteral antibiotic.

Ampicillin↗
PubMed1977

Taste and olfaction in human obesity.

Earlier studies have shown differences between normal weight and obese humans in responsivity to external and internal stimuli. This study shows that normal weight and obese subjects do not differ in hedonic response to sucrose (taste) and benzaldehyde (odor). However, a perceptual typing of individuals based upon hedonic response is possible for both gustatory and olfactory processes. Ratings of pleasantness for the sweet taste of sucrose appear to generalize to the food-related odor of bitter almonds. The method of magnitude estimation as applied to the study of taste and olfaction in man may reveal relationship between changes in internal state and hedonic behavior.

Adult↗
PubMed1977

Serotypes of Pasteurella haemolytica in ovine pasteurellosis.

The serotypes of 406 strains of Pasteurella haemolytica were determined. These came from cases of pasteurellosis in sheep of all ages. Serotype A2 was the most frequent and comprised 33 per cent of all strains recovered. Serotypes T3, T4 and T10 comprised 16, 14 and 12 per cent of the total respectively. Serotypes A1 and A6 contributed 5 per cent each, A7, 18, A9, A11 and A12 a total of 8 per cent collectively, serotype A5 was not isolated at all while 6 per cent of strains were serologically untypable. More strains were received during September, October and November than at any other three-month period and in these months the T biotype predominated.

Animals↗
PubMed1976

Effects of body weight and food intake on pleasantness ratings for a sweet stimulus.

A physiological role for pleasure has been suggested from observations that glucose loads reduced pleasantness ratings for sweet stimuli in normal weight but not in weight-reduced subjects. This hypothesis was reexamined in fasting and food-loaded, lean and obese subjects. Magnitude estimates of sweetness and pleasantness were obtained for seven sucrose concentrations. Indices of obesity including percent overweight, percent body fat, and body mass index were calculated. Pleasantness ratings of fasting subjects either increased up to a moderate concentration and then declined (type I hedonic response) or increased monotonically with concentration (type II hedonic response). Both types of response were found in lean and obese subjects. Within each weight group there appeared a negative correlation between pleasantness response and indices of obesity. Caloric loads reduced hedonic ratings of type II lean and obese subjects, but did not affect pleasantness response of type I lean and obese subjects. These findings indicate the presence of an hedonic monitor biased by body weight and caloric intake. The data suggest a physiological role for pleasure in regulating body weight at different set points in lean and obese subjects.

Adult↗
PubMed1975

Vaccination against Vibrio (Campylobacter) fetus infection in sheep in late pregnancy.

A single injection of vaccine containing disrupted formol-killed Vibrio (campylobacter) fetus var intestinalis serotype V was shown to give good protection against abortion from an oral challenge of the same serotype administered simultaneously. Protection was also afforded by vaccination at the time of the first abortion in sheep infected orally one month previously. These results suggest that vaccination subsequent to an abortion might be of value in preventing a proportion of further abortions.

Abortion, Veterinary↗
PubMed1975

Experimental infection of lambs with an aerosol of Pasteurella haemolytica.

Specific pathogen free lambs were exposed to an aerosol of Pasteurella haemolytica. Ten lambs vaccinated with an adjuvanted killed P haemolytica vaccine and nine units of P haemolytica administered in an aerosol. Pneumonia histologically indistinguishable from natural pneumonic pasteurellosis occurred in one vaccinated lamb and in four control lambs.

Adjuvants, Immunologic↗
PubMed1975

Protein electrophoretic pattern of Pasteurella haemolytica.

Electrophoresis in polyacrylamide gels of the constituent proteins of the 12 serotypes and an untypable strain of Pasteurella haemolytica showed a pattern of bands that divided the group into two. This division conformed to the A and T biotype groupings of Smith (1959) although the serotype A9 showed only minor band difference from the three T serotypes 3, 4 and 10. It was not possible by this method to separate all the type strains from each other by the specific recognition of the patterns of protein mobilities produced.

Bacterial Proteins↗