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Biomedical subjects

A Harrison

Publications and source records attributed to A Harrison.

At least 217 records · Page 12Linked to original sources
PubMed1981

Effects of breathing retraining in patients with chronic obstructive pulmonary disease.

Subjects with severe chronic obstructive pulmonary disease (COPD) were studied to evaluate the effects of breathing retraining (BRT) on exercise tolerance. Twenty-two subjects exercised on a treadmill three times weekly for six weeks. Twelve of the subjects (controls) then exercised for three more weeks; the other ten subjects received three more weeks of exercise reconditioning plus BRT. Results of routine pulmonary function and exercise tests were similar in both groups at the beginning of the study and after six weeks of exercise. However, in the last three weeks of the study, increments in exercise performance were significantly greater in the BRT subjects than in controls (P less than .002). Following BRT, respiratory rate during exercise decreased (P less than .005) and tidal volume and PaO2 during exercise increased (P less than .05). Thus, these data suggest that BRT increases exercise performance in subjects with severe COPD.

Breathing Exercises↗
PubMed1981

Effects of 6-chloro-6-deoxysugars on glucose oxidation in rat spermatozoa.

6-Chloro-6-deoxyfructose or 6-chloro-6-deoxyglucitol (greater than 90 mumol/kg/day), 6-chloro-6-deoxyglucose or 6-chloro-6-deoxymannose (greater than 120 mumol/kg/day) and 6-chloro-6-deoxygalactose (greater than 300 mumol/kg/day) all had an antifertility action in the male rat when given by mouth. Spermatozoa from the infertile rats were unable to oxidize glucose. This effect was always produced by a lower dose than the antifertility effect and the threshold dose for the 2 effects varied in a parallel fashion between the different 6-chloro-6-deoxysugars. Glucose oxidation appeared to be inhibited at the triose phosphate isomerase or glyceraldehyde 3-phosphate dehydrogenase reaction. These effects of 6-chloro-6-deoxysugars are similar to those of alpha-chlorohydrin. The activities of the glycolytic enzymes were greatly in excess of the observed flux through the pathway and high concentrations of glucose 6-phosphate and triose phosphate accumulated in rat spermatozoa incubated with 2 mM-D-glucose.

Animals↗
PubMed1981

The effect of 6-chloro-6-deoxysugars on adenine nucleotide concentrations in and motility of rat spermatozoa.

Spermatozoa from rats treated with 6-chloro-6-deoxyglucose (120 mumol/kg/day) were as motile as those from controls soon after dilution but rapidly became immotile when 3 mM-D-glucose was the only substrate present. Control spermatozoa were more motile when 2 mM-pyruvate + 4 mM-DL-lactate rather than 2 mM-D-glucose was present and the former substrate allowed spermatozoa from treated rats to remain motile. The concentrations of the adenine nucleotides declined rapidly during 40 min incubations when th substrate was 2 mM-D-glucose. The ATP/ADP ratio and the energy charge (ATP + 1/2 ADP/ATP + ADP + AMP) were maintained in spermatozoa from control rats but not in those from treated rats. When the substrate was 2 mM-pyruvate + 4 mM-DL-lactate adenine nucleotides were not lost as rapidly and there was less difference between spermatozoa from control and treated rats.

Adenine Nucleotides↗
PubMed1981

The role of oxidative phosphorylation in the generation of ATP in human spermatozoa.

Washed human spermatozoa had an endogenous oxygen uptake of 2.14 +/- 0.17 nmol O2/10(8) spermatozoa/min (mean +/- s.e..m., n = 35) which was stimulated by succinate (Vmax = 9.64 +/- 0.44 nmol O2/10(8) spermatozoa/min) but not by other substrates. The ATP concentration in freshly washed spermatozoa was 12.18 +/- 0.54 (s.e.m.) nmol/10(8) spermatozoa (n = 26) and was maintained for 2 h in the presence of 2 mM-D-glucose but fell to 9.56 +/- 0.73 (s.e.m.) nmol/10(8) spermatozoa (n = 13) in its absence. The presence of 2 microM-antimycin A, 2 microM-rotenone, 0.4 microM-carbonyl cyanide m-chlorophenyl hydrazone or 8 microM-oligomycin caused the ATP concentration to fall to less than 2 nmol/10(8) spermatozoa but their effect was partly alleviated by 2 mM-glucose. Sodium malonate (5 mM) prevented the stimulation of respiration by succinate but had no effect on the ATP concentration of the spermatozoa or their ability to produce 14CO2 from [U-14C]glucose. The least active of the tricarboxylic acid cycle enzymes was 2-oxoglutarate dehydrogenase (EC 1.2.4.2) (3.1 +/- 0.6 (s.e.m.) nmol substrate transformed/10(8) spermatozoa/h (n = 4). Cytochrome c oxidase (EC 1.9.3.1) was much less active than in rat spermatozoa (22.3 +/- 6.0 (s.e.m., n = 4) and 615 +/- 87 (n = 4) nmol transformed/10(8) spermatozoa/min). It is concluded that human spermatozoa can obtain ATP by the respiration of endogenous substrate but the substrates and metabolic pathways involved remain obscure.

Adenosine Triphosphate↗
PubMed1980

Loss of mouse testis mass after X-irradiation or injection of 22Na.

Mass loss in the mouse testis per unit of absorbed dose was used as a means of comparing acute external with protracted internal whole body irradiation. The external and internal sources were X-rays and 22Na respectively. Estimates of the absolute dose to the testis from 22Na were made. The effects of acute and protracted radiation on the integrated loss in mass in the testis per unit of absorbed dose are similar.

Animals↗
PubMed1980

One year's study of growth and total hydroxyproline excretion in scoliotic children.

21 children with scoliosis were studied for a year during which time 24-hour urinary total hydroxyproline levels are estimated and anthropometric measurements were made on 4 occasions. The total hydroxyproline levels (using hydroxyproline centiles) and the uncorrected heights of the children were all normal. The sitting heights of the children were below average, but, although the sample was small, the findings indicate that the children's 'uncoiled' height would be greater than average.

Adolescent↗
PubMed1980

Effect of alpha-chlorohydrin on glucose metabolism by spermatozoa from the cauda epididymidis of the rhesus monkey (Macaca mulatta).

Spermatozoa from the cauda epididymidis of the rhesus monkey had metabolic properties similar to those published for ejaculated spermatozoa. The concentration of glycolytic intermediates was low until 2 mM-glucose was added; glucose 6-phosphate, fructose 1,6-bis-phosphate and the triose plhosphates then increased but glycerate 3-phosphate did not. It was concluded that the activity of glyceraldehyde 3-phosphate dehydrogenase (EC 1.2.1.12) limited flux through the glycolytic pathway. The production of lactate and CO2 from glucose was strongly inhibited in the presence of 5 or 10 mM-alpha-chlorohydrin. The energy charge of the spermatozoa was low before and after 1 incubation with 2 mM-glucose (0.5 +/- 0.05 and 0.05 +/- 0.06 respectively) and the value after the incubation was decreased in the presence of 5 or 10 mM-alpha-chlorohydrin (0.17 +/- 0.05 and 0.15 +/- 0.04 respectively). alpha-Chlorohydrin inhibited glycolysis at the glyceraldehyde 3-phosphate dehydrogenase reaction.

Adenine Nucleotides↗
PubMed1979

A double blind comparison of thiothixene and a trifluoperazine/chlorpromazine composite in the treatment of chronic schizophrenia.

Thirty chronic schizophrenic patients participated in a double-blind crossover trial of thiothixene (Navane) and a control drug combination of trifluoperazine and chlorpromazine. No statistically significant difference was found between the two drug conditions on numerous behavioural scales. Experience with thiothixene suggested that it was comparable with control drugs in the activation of withdrawn patients but needs to be used in combination with a more sedative antipsychotic agent in the treatment of some paranoid patients.

Chlorpromazine↗
PubMed1979

A correlation between abrasion resistance and other properties of some acrylic resins used in dentistry.

This investigation studies the relationship of hardness, elastic modulus and scratch width as dependent variables to the abrasion resistance of twenty-three dental acrylic resins. The multiple correlation R, when all three variables are used as predictors, is 0.727. Because of the significant intercorrelations between the variables themselves a stepwise multiple regression analysis showed hardness as a redundant variable. Abrasive wear can be estimated from the following equation Abrasive wear = 806.1 - 0.1498 modulus + 0.681 scratch width (R = 0.725; standard deviation of estimate +/- 50.8) The deletion of scratch width does not appreciably reduce the standard deviation of the estimate: Abrasive wear = 1063.4 - 0.2055 modulus (r = 0.683; standard deviation of estimate +/- 50.3) The method of curing the specimens conformed to the respective manufacturers' instructions. Abrasion and scratch tests were performed using methods developed by the authors and previously described in the literature, whereas the hardness and elastic modulus results were devised from standard test procedures. Further research is currently in progress to improve the predictive power of abrasion resistance with additional new variables.

Acrylic Resins↗
PubMed1979

The specificity of schizophrenic thought disorder.

Bannister and Salmon (1966), in a repertory grid study, reported that 'thought-disordered schizophrenics lost significantly more reliability and social agreement when shifted from object to people construing than normal'. This conclusion is of doubtful validity, since the between-grids variable, people vs. objects, was confounded with at least five other variables of possible relevance, three of which have been found by subsequent workers (McPherson & Buckley, 1970; Williams, 1971; Heather, 1976) to affect performance on grids. The main aim of the present experiment was to determine the effects of as many as possible of these variables. The subsidiary aim was to replicate, or otherwise, the findings of Frith & Lillie (1972) and Haynes & Phillips (1973) that the effective discriminator between thought-disorder schizophrenics and other groups on repertory grid tests is not intensity of relationship between constructs but pure (element or internal) consistency. Six grids involving all feasible combinations of rating familiar and unfamiliar people and objects on psychological and physical constructs were administered to 10 thought-disordered schizophrenics, 10 non-thought-disordered schizophrenics and 10 normals. As regards the main aim of the experiment it was found that there was no significant grids x diagnoses interaction on pure consistency, but that there was one on intensity, even with pure consistency partialled out. Taking previous work into consideration, it appears that this effect is weak, inconsistent from experiment to experiment, and anomalous in the present study. As regards the subsidiary aim, the findings of the two previous experiments cited above were confirmed. The discrepant results of McPherson et al. (1973) are considered, and it is noted that they held only for a subsample of the schizophrenic group in that experiment, the results for the total sample of schizophrenics, manics and depressives not being inconsistent with those of other experiments. The theoretical and practical implications of these and previous finding are indicated.

Female↗
PubMed1978

Amniotic fluid infection at term.

The incidence of amniotic fluid infection, determined by histological examination of the placenta and cord and cytological examination of gastric aspirate, was found to be high (52%) in term deliveries. A detailed histological system of grading the inflammatory response was used. No relationship was found between maternal nutritional factors or the baby's weight and inflammatory response, as judged by histological examination. The presence of pus cells in the gastric aspirate was of only limited diagnostic value. The absence of clinically obvious infection in the infants suggested amniotic fluid colonization without spread to the fetus.

Amniotic Fluid↗