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Biomedical subjects

M Peters

Publications and source records attributed to M Peters.

At least 433 records · Page 24Linked to original sources

Handedness: coordination of within- and between-hand alternating movements.

Two models of coordination of within- and between-hand alternating movements are compared. Model 1 assumes that control of bimanual movement passes back and forth between two independent systems, each of which guides one hand, and that the performance of alternating tapping movements (e.g., right index, right middle fingers) within a hand is very different from performance of alternating movements between hands (right index, left index fingers). The model suggests that right/left performance asymmetries on given tasks reflect the characteristics of the independent systems and would therefore predict that factor analysis would yield a "hand" factor. Model 2 assumes that a single system initiates and terminates movement in two subsystems, each of which guides one hand, and it suggests that the task of guiding alternating tapping movements within a hand is very similar to the task of alternating movement between hands. Model 2 would not predict an independent "hand" factor in the factor analysis of performances of tasks yielding left/right asymmetries; the asymmetries presumably arise because the single higher order system has better access to one of the subsystems than to the other. Analyses of performance of within- and between-hand alternations, single-finger tapping movements, and a pursuit rotor task in 92 subjects lend clear support to Model 2.

Female↗

Fungal infection associated with gastroduodenal ulceration: endoscopic and pathologic appearances.

Three patients with peptic ulcers diagnosed at upper gastrointestinal endoscopy are reported. All were seriously ill (2 debilitated alcoholics) and died soon afterwards. Fungi were recognized in the antemortem specimen of one of the two ulcers biopsied at the time of endoscopy and in the postmortem specimens of all. In two, demise appears to have been precipitated by erosion of the wall of a major artery by fungal invasion. Culture of the ulcer based as well as throat swabs and stool examination for mycelial and yeast forms of fungus in susceptible patients may allow a more accurate diagnosis to be made and therapy to be instituted.

Adult↗

Occurrence of tumors and effects on longevity after limited x-irradiation in man.

An analysis was made of survival times and causes of death of patients given local irradiation in small dosage during 1948--1960. The study involved 61 patients with peptic ulcers in whom hyperacidity was treated by partial gastrectomy and gastric irradiation, and their mortality was compared with that of 61 age- and sex-matched gastrectomized but nonirradiated control patients. For both groups the survival rates were related to "normal population" survival rates calculated from age-, sex- and year-specific mortality rates for the population of Victoria. Ten years after irradiation the relative survival rates of the irradiated and control groups began to diverge, due to more deaths than expected in the irradiated group. The irradiated group had a significantly increased number of deaths due to cancer, particularly carcinoma of the stomach, as well as an increase in deaths not caused by cancer. The mortality of the nonirradiated control patients was not significantly greater than that of the normal population.

Adult↗

Multiple myeloma and gastric carcinoma. Possible late effects of limited abdominal X-irradiation.

A man, aged 34, was treated in 1954 for duodenal ulcer by antroduodenectomy followed by X-irradiation to the stomach in a dose of 2,000 rads. Over two decades, he developed several conditions attributable to the previous irradiation, including the physical appearances of premature ageing, shrinkage of the left kidney due to irradiation nephritis, immune deficiency, multiple myeloma of IgA type, and lastly, carcinoma of the stomach. The kidneys, especially the left, the bone marrow and stomach would have been in the field of X-irradiation. These effects of local X-irradiation are discussed in relation to the known effects of total body irradiation in causing decreased longevity in animals and inducing cancer in man.

Aging↗

Motor innervation of the pharynx levator muscle of the snail, Helix pomatia: physiological and histological properties.

(1) Motor innervation of the pharynx levator muscle of Helix pomatia was investigated with intracellular recording and axonal iontophoresis of cobalt chloride. (2) Muscle fibers respond to direct electrical stimulation of the muscle with active graded responses or non-overshooting spike potentials. (3) Each fiber is innervated via the external and internal lip nerves by several (mostly 3) excitatory nerve fibers each. Two types of EPSPs can be distinguished according to amplitude, duration, and facilitation. (4) Axonal CoCl2-staining via an external lip nerve branch revealed many nerve fibers entering the muscle and branching there into a rich network of blebbed fibers of various diameters.

Animals↗

Left-handers and right-handers compared on a motor task.

Finger-tapping performance of 45 subjects of each sex and handedness combination, for a total of 180, was compared. Performance measures were speed (mean intertap interval) and regularity (standard deviation of intertap interval). Males tapped faster but not more regularly than females. The between-hand differences in performance were smaller for both measures in left-handers. When absolute magnitudes of between hand differences were compared, females showed smaller differences in regularity of tapping than males. Speed and regularity of tapping were statistically independent; both measures discriminated well between the preferred and nonpreferred hand of both handedness groups, but the differences in speed were more marked than the differences in regularity. Data on the performance of children on the same task are included for comparative purposes.

Journal Article↗

Amoebic liver abscess: a retrospective clinical evaluation of twenty-seven cases.

Twenty-seven patients with Amobebic Liver Abscess were observed during the last two years and were analysed retrospectively with respect to diagnostic procedures and therapeutic strategies. Seven of the 27 patients had surgery and were subsequently referred to our hospital. Those patients with surgery had a longer duration of illness and hospitalization (3.3 months) compared to the other 20 patients with chemotherapy alone (2 months). Most important diagnostic parameters for extraintestinal amoebiasis were: typical clinical findings, time spent in tropical or subtropical countries, strongly positive Latex agglutination against Entamoeba histolytica antigen, and isotope and/or ultrasound scanning to confirm abscess formation in the liver. The vast majority of abscesses were found in the right liver lobe. Response to treatment with complete cure was seen in all patients, regardless of whether Metronidazole alone or combinations of Metronidazole with Chloroquine and Metronidazole and Dehydroemetine or Chloroquine and Dehydroemetine were used. There is a need for prospective therapeutic studies to compare the different drug regimen concerning side-effects, toxicity, costs, application, and duration of hospitalization. From the retrospective data it seems that surgery is not beneficial for the patients.

Adult↗

Studies on the enhancement of rat islet allografts.

Attempts to improve the induction of immunological enhancement of (AS X August)F1 pancreatic islet allografts in diabetic AS rats have been carried out. First, by treating the diabetic AS recipient with enhancing serum obtained from AS rats with functioning enhanced (AS X August)F1 islet allografts. In these rats on 1 of 5 islet allografts had a prolonged survival, the other 4 being rejected by 2 days. Second, by transplanting (AS X August)F1 islet allografts into diabetic AS rats bearing functioning enhanced (AS X August)F1 cardiac allografts. All of these islet allografts were rejected by 2 days.

Animals↗