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Biomedical subjects

S Hamilton

Publications and source records attributed to S Hamilton.

At least 127 records · Page 7Linked to original sources
PubMed1982

Peri-articular erosions in the hands and wrists in haemodialysis patients.

Peri-articular erosions have been described in primary and secondary hyperparathyroidism. Seventy-two patients with chronic renal failure were reviewed for the presence of erosions. These were found in 15 patients while another 20 patients showed other evidence of secondary hyperparathyroidism. The distribution of erosions was unlike that of other erosive arthropathies, and there were no relevant clinical symptoms. Previous reports of peri-articular erosions in hyperparathyroidism are reviewed. It is concluded that peri-articular erosion is a common finding in secondary hyperparathyroidism and may be the major radiographic feature of this condition.

Adult↗
PubMed1982

Discriminating good sleepers from insomniacs using all-night polysomnograms conducted at home.

Twelve good sleepers and 12 insomniacs were recorded over three nights in their homes. Subjective assessment of sleep indicated minimal disruption due to sleep recording procedures. A cut point of 88 per cent sleep efficiency resulted in correct classification of nine poor sleepers and 10 good sleepers. Multiple discriminant function analyses, using variables related to rapid eye movement sleep, resulted in the same number of correct classifications. The two indices combined resulted in 100 per cent exclusion of false positives for good sleepers and insomniacs. Insomniacs also showed more night-to night variability in sleep and greater difficulty in returning to sleep once aroused. These results show that good sleepers and insomniacs can be distinquished with a high degree of resolution using variables derived from the home all-night sleep recording.

Adult↗
PubMed1981

First night effects in good sleepers and sleep-maintenance insomniacs when recorded at home.

Home sleep recordings were conducted over four consecutive nights with 12 good sleepers and 12 sleep-maintenance insomniacs. Good sleepers showed decreased sleep efficiency and increased min awake after sleep onset on night 1. Insomniacs showed extended latency to onset of the first REM period and decreased REM in the first third of the initial recording night. Good sleepers and insomniacs reported no significant differences in adequacy of sleep between the first and subsequent sleep nights.

Adult↗
PubMed1980

Psychophysiological differentiation between psychopathic and schizophrenic abnormal offenders.

This paper is a follow-up of research by Schalling (1978), Mednick (1975), Mednick & Hutchings (1978), Venables (1975) and a pilot study on the psychophysiological response characteristics of maximum security patients, Hinton & O'Neill (1976, 1978). In line with hypotheses, patients rated as 'disoriented' by nurses and diagnosed 'schizophrenic', tended to have increased spontaneous electrodermal fluctuations and reduced orienting response recovery time relative to non-'disoriented' and diagnosed 'psychopaths'. Also low rate spontaneous fluctuation in skin resistance plus long skin resistance ORt/2 differentiated 'high public risk' psychopaths from 'low risk' domestic offenders.

Adult↗
PubMed1980

Abnormalities of vasoactive intestinal polypeptide-containing nerves in Crohn's disease.

The possible involvement of nerves containing vasoactive intestinal polypeptide in Crohn's disease was investigated by immunocytochemistry and radioimmunoassay of specimens from 17 patients with well-defined clinical and histologic features of the disease. The characteristic pattern of slender fibers, evenly distributed across the gut wall, was seen in specimens taken from controls, which consisted of (a) specimens from uninvolved areas of gut from carcinoma resection (n = 17) and (b) jejunoileal specimens obtained during bypass operation for obesity (n = 8) as well as in four of the six specimens from patients with ulcerative colitis. In contrast, this characteristic pattern was lost in all 17 patients with Crohn's disease, the pattern being replaced by thickened and more intensely immunostained fibers. These changes were consistently found in the mucosa and submucosa, and in 13 of the Crohn's disease cases, the abnormal pattern was totally transmural, involving both the myenteric and submucous plexus as well as the muscle layers. There was a > 200% increase in VIP content, as determined by radioimmunoassay, in Crohn's disease (294 +/- 29 pmol/g wet wt, mean +/- SEM) in comparison with (a) ulcerative colitis (93 +/- 5 pmol/g [P < 0.001]), and (b) controls consisting of carcinoma resection (108 +/- 39) and bypassed gut from obese patients (86 +/- 27 [P < 0.001]). At least part of the previously documented autonomic nerve changes in Crohn's disease are, thus, due to an increase in vasoactive intestinal polypeptide innervation.

Adolescent↗
PubMed1979

Radio-isotope bone scanning in suspected osteomyelitis in children.

The usefulness of radio-isotope bone scanning in suspected osteomyelitis has been widely acclaimed. Fourteen children had rectilinear bone scans performed three hours after injection of Tc99m methylene diphosphonate. A diagnostic accuracy of 56% was achieved, which is lower than in other series. The reasons for this are discussed and the value of bone scanning in the evaluation of osteomyelitis is questioned.

Adolescent↗
PubMed1979

Interaction of actin with myosin A and heavy meromyosin.

Ca2+ "free" actomyosin suspensions as well as actin heavy meromyosin (HMM) solutions in the presence of Ca2+ showed no contractile response (superprecipitation) and had low steady-state Mg2+-ATPase activity. Under the same experimental conditions both the enzymatic activity increased and contractile response was restored if the solubility of the proteins was depressed by the addition of polyethylene glycol 4000 (PEG-4000). The stability of the enzymatically active actomyosin or actin HMM complexes was 10 times lower in cleared solutions than in the insoluble actomyosin or actin HMM suspensions. It was concluded that soluble actomyosin or actin HMM solutions are inadequate test tube models for studying muscular contraction.

Adenosine Triphosphatases↗
PubMed1978

Halothane, surgery, immunosuppression and artificial pulmonary metastases.

C57B1/6 mice were given intravenous tumor cells on day O. Mice were then given either a brief exposure to halothane anesthesia or given halothane and then underwent a hind limb amputation. Immune testing was done at varying time intervals and correlated with the development of artificial pulmonary metastases. The effects of a single 15 minute exposure to halothane on the immune system are probably short-lived and no effect on cell-mediated cytotoxicity was seen on day 7, nor was an increase in pulmonary metastases observed. However, when anesthesia was combined with surgery, cell-mediated cytotoxicity was impaired and an increase in pulmonary metastases was seen. The use of thiabendazole (TBZ), an nonspecific immunopotentiator, in the perioperative period restored the cell-mediated cytotoxic response and resulted in a significant decrease in pulmonary metastases.

Animals↗
PubMed1978

Psychological test performance and sedation thresholds of elderly dements, depressives and depressives with incipient brain change.

As expected, dements, depressives and patients with a mixed psychopathology were differentiated from one another on the sedation threshold measure and on a number of psychological tests. In depressives responding to treatment significant changes in physiological and psychological measures, which had been reported in an earlier study could not be replicated except for an increase of psychomotor speed. In the present sample of patients there were significant correlations between various psychological measures and between them and the levels of the sedation threshold, suggesting that sedation thresholds and psychological tests measured related cerebral functions. Evidence obtained from the earlier investigations to the effect that cerebral age changes short of those occurring in dementia may facilitate the occurrence of depression in late life was only weakly confirmed by the replication study.

Aged↗
PubMed1977

The effect of cyclandelate in depressed and demented patients: a controlled study in psychogeriatric patients.

In a double-blind clinical trial the effects of the vasodilator drug cyclandelate (in a dose of 1200 mg daily) were studied in a group of patients with depressive illnesses or dementing conditions. The measures used before treatment and after six weeks' treatment were: clinical rating, psychometric tests (Paired Associate Learning Test, Digit Copying Test, Digit Substitution Test, and Serial Learning Test), cortical evoked potentials, the sedation threshold and the Gresham Questionnaire. In the depressive group there were no significant differences in the changes in scores at six weeks in three groups: those who received cyclandelate plus amitriptyline, those who received placebo plus amitriptyline, and those who received neither placebo nor cyclandelate. In the demented group there were significant changes in favour of the placebo on two measures (Digit Copying test, and one component of the auditory evoked response). The results do not support the previously reported views claiming, in a number of studies, a significant improvement in the performance of both demented and normal elderly subjects treated with cyclandelate. The significance of these findings is discussed.

Aged↗
PubMed1977

Cyproheptadine inhibition of stimulated plasma renin activity.

Plasma renin activity (PRA) was stimulated by oral frusemide (60 mg) in 4 normal male subjects. Cyproheptadine (Periactin), a serotonin antagonist, was then administered (2 mg orally four times daily) for 7 days and the PRA response to frusemide re-evaluated in the 4 subjects. A highly significant mean inhibition (P less than 0.01) of frusemide stimulated PRA was demonstrated after cyproheptadine administration. Our results show that serotonin, presumably acting via central pathways, may play a role in renin regulation and that this pathway can be inhibited by cyproheptadine.

Adult↗