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Biomedical subjects

J Thomson

Publications and source records attributed to J Thomson.

At least 145 records · Page 8Linked to original sources

ColE1 hybrid plasmids for Escherichia coli genes of glycolysis and the hexose monophosphate shunt.

The Clarke-Carbon clone bank carrying ColE1-Escherichia coli DNA has been screened by conjugation for complementation of glycolysis and hexose monophosphate shunt mutations. Plasmids were identified for phosphofructokinase (pfkA), triose phosphate isomerase (tpi), phosphoglucose isomerase (pgi), glucose-6-phosphate dehydrogenase (zwf), gluconate-6-phosphate dehydrogenase (gnd), enolase (eno), phosphoglycerate kinase (pgk), and fructose-1,6-P2 aldolase (fda). Enzyme levels for the plasmid-carried gene ranged, for the various plasmids, from 4- to 25-fold the normal level.

Conjugation, Genetic↗

Alterations in ventilation and gas exchange during exercise-induced carbohydrate depletion.

The relationship between ventilation (VE), oxygen consumption (VO2), and carbon dioxide production (VCO2) during work were studied in four trained males during exercise-induced carbohydrate depletion. Repeated bouts of heavy treadmill exercise (6 min at 95% VO2 max) were performed once per hour for 24 h in order to promote a shift in energy substrate from carbohydrate to fat. Measurements of VO2 and VCO2 recorded during each minute indicated that VO2 was unaffected by the number of runs, whereas VCO2 showed a progressive reduction which amounted to 24% during the final run. A corresponding decline of 19% was observed in the respiratory exchange ratio. No significant change in VE occurred between any of the runs. It is concluded that during heavy, repeated, muscular exercise, reductions in VO2, strongly suggestive of an increased fat oxidation, are not accompanied by a corresponding change in ventilation.

Adult↗

Iron: a possible heterotropic effector of prolyl hydroxylase.

The mechanism of ferrous ion binding to prolyl hydroxylase (prolyl-glycyl-peptide,2-oxoglutarate:oxygen oxidoreductase, EC 1.14.11.2) was studied according to Koshland's curve-fitting procedure (Cornish-Bowden, A. and Koshland, Jr., D.E. (1970) Biochemistry 9, 3325--3336). The calculated data obtained by means of the unrestricted Adair equation were found to provide an adequate fit with experimentally obtained values, whereas those obtained on the basis of Michaelis-Menten kinetics did not. This suggests that prolyl hydroxylase could be an allosteric enzyme under positive heterotropic control.

Computers↗

Chronic lymphatic leukemia presenting as atypical rosacea with follicular mucinosis.

A case is described in which the initial clinical and histological features were suggestive of rosacea. Subsequent progress revealed the diagnosis to be chronic lymphatic leukemia. The initial biopsy specimens were reviewed and small but definite quantities of follicular mucinosis were noted after appropriate staining. If this had been noted earlier the diagnosis would have been made more rapidly. This case demonstrates the importance of detecting follicular mucinosis. We are not aware of follicular mucinosis having been described in association with chronic lymphatic leukemia previously. It is also rare for leukemias other than the monocytic type to present with cutaneous lesions, though skin lesions may occur in established cases.

Aged↗

Viloxazine, sleep, and subjective feelings.

The sleep of eight volunteers (mean age 55) was recorded electrophysiologically while viloxazine 200 mg was taken daily for 3 weeks, preceded and followed by a week of matching blanks. The volunteers also made ratings of their feelings on visual analogue scales. Another 15 volunteers (mean age 34) took viloxazine 300 mg daily for 3 weeks, preceded and followed by 3 weeks of matching blanks, and they also made daily ratings of feelings. The drug diminished sleep duration and caused more frequent and longer transitions into wakefulness and drowsiness. Slow-wave sleep decreased and stage 2 increased. REM sleep was markedly reduced, especially initially, and there was a withdrawal rebound. Viloxazine impaired subjective concentration mood, and quality of sleep. Three volunteers, however, had striking mood elevation. The drug caused a small loss of weight, which correlated with gastrointestinal symptoms. Three older subjects experienced withdrawal vomiting and prostration. Viloxazine shares properties with imipramine and with amphetamines.

Adult↗

Effect of oestrogen on the sleep, mood, and anxiety of menopausal women.

A double-blind controlled study of the effect of piperazine oestrone sulphate on sleep, depression, anxiety, and hot flushes was performed in 34 perimenopausal women. Half of the patients were given six weeks' placebo followed by eight weeks' oestrogen, and half remained on placebo throughout. Sleep was recorded electrophysiologically every week, and mood and anxiety were rated daily by means of visual analogue scales. Hot flushes were counted daily. Observer rating scales of anxiety and depression were complete at intervals. During the first month of active treatment the amount of intervening wakefulness in the first six hours of sleep decreased significantly more in the oestrone group than in those on placebo. Between the baseline period and the second treatment month the oestrone group showed a significantly greater decrease in the total amount of intervening wakefulness and in the frequency of awakenings. Their total amount of rapid eye movement sleep increased. Mood and anxiety improved and the number of hot flushes decreased to a similar degree in both groups. Although oestrogen did reduce the number of episodes of wakefulness in perimenopausal women complaining of insomnia, its effects on their psychological symptoms were little different to those of placebo.

Anxiety↗

Acupuncture analgesia: an experimental investigation.

A study was designed to establish whether acupuncture has any analgesic properties beyond those of suggestion. In three one-hour experimental sessions the increases in detection thresholds and tolerances for thermal pain at six body locations on 12 subjects were compared. A control session (without needles) was followed by one session in which electrically stimulated needles were inserted in accord with Chinese practice, and another in which the needles were inserted to avoid all recognised acupuncture "points." Acupuncture was significantly more effective than suggestion in raising overall body pain thresholds but just below significance for tolerances. A significant disproportionate effect on the epigastrium, predicted by the choice of acupuncture points, was found for tolerances but not thresholds.

Abdomen↗