Search PubMed⌕ Search

Biomedical subjects

A Wakeling

Publications and source records attributed to A Wakeling.

50 records · Page 3Linked to original sources
PubMed1983

Platelet hyperaggregability and increased alpha-adrenoceptor density in anorexia nervosa.

Plasma norepinephrine concentrations in a group of malnourished patients with anorexia nervosa were significantly (P less than 0.002) lower than those in an age- and sex-matched group of normal subjects. Platelet total alpha-adrenoceptor densities of these patients significantly (P less than 0.002) exceeded those of the controls. The increased total alpha-adrenoceptor density was due to an increase in the alpha 2-adrenoceptor receptor subtype, which mediates epinephrine-induced platelet aggregation. Accordingly, the aggregation response of the patients' platelets was significantly (P less than 0.002) enhanced after epinephrine challenge. We suggest that the starvation-induced fall in plasma norepinephrine levels is associated with the up-regulation of platelet alpha-adrenoceptors. This, in turn, accounts for exaggerated epinephrine-induced platelet aggregation in anorexic patients.

Adolescent↗
PubMed1982

Set-point displacement for behavioural thermoregulation in anorexia nervosa.

1. The temperatures of thermal stimuli which evoked a feeling of maximal pleasantness upon contact with the hands of 14 malnourished patients with anorexia nervosa and 19 control subjects have been determined. A uniform skin temperature of 35 degrees C for all individuals studied was achieved by immersion of the subjects and patients in water at that temperature. Core temperatures of the anorexia patients were similar to those of the control subjects, but six of the patients preferred temperatures that were significantly higher than those of the control subjects. The thermal preferences of the remainder of the patients were similar to those of the control subjects. 2. The abnormally high thermal preferences of some of the anorexic patients could not be attributed to abnormal thyroid status, since values for serum free thyroxine measured in this group were similar to those obtained for the remaining patients. The abnormal responses persisted after there had been a substantial gain in the patients' weight and did not therefore appear to be directly due to malnutrition. 3. Elevation of deep body temperature produced an expected shift in preference towards lower stimulus temperatures in a sample of subjects from the control group, and in the patients who had initially preferred temperatures within the range of the controls. In the patients who had initially preferred abnormally high stimulus temperatures, however, hyperthermia produced little change in thermal preference. 4. It is suggested that an elevation in the set-point temperature for behavioural thermoregulation can occur in some patients with anorexia nervosa, and that this displacement may contribute to the distressing sense of cold which some patient experience.

Adolescent↗
PubMed1980

Altered thresholds for thermoregulatory sweating and vasodilatation in anorexia nervosa.

The changes in peripheral (hand) blood flow that occurred when deep body temperature was raised were measured in 13 patients with anorexia nervosa and 13 control subjects. The relation between blood flow and core temperature was shifted to the left in the patients with anorexia, with the onset of vasodilatation occurring at lower core and mean skin temperatures: no significant differences in the slopes of the responses were evident. The onset of thermal sweating occurred at lower core and mean skin temperatures in the patients with anorexia than in the controls. After ingestion of a high-energy liquid meal core temperature increased in the patients, and this was accompanied by a significant rise in peripheral blood flow in most cases. A similar meal in the normal subjects was followed by either no change in core temperature or a slight fall, and no consistent change in peripheral blood flow. These findings suggest that the lowering of thresholds for thermoregulatory sweating and vasodilatation may be a contributory factor to the abnormally low core temperature of patients with anorexia and may also explain some of their common complaints relating to feelings of warmth in the hands and feet after meals.

Adolescent↗
PubMed1979

Amenorrhoea, body weight and serum hormone concentrations, with particular reference to prolactin and thyroid hormones in anorexia nervosa.

Twenty women with anorexia nervosa were investigated at varying stages during weight gain. Basal prolactin and TSH and prolactin responses to TRH were normal and unrelated to body weight. LH, FSH and 17 beta oestradiol were low in emaciated patients and rose with weight gain. There was no correlation between serum gonadotrophin and prolactin concentrations. T3 and T4 concentrations were low but T3 rose with weight gain during refeeding over 4-6 weeks, whereas T4 remained low. A positive correlation was found between the TSH response to TRH and body weight. The abnormalities in the hypothalamic-pituitary-thyroid axis were similar to those seen in a variety of chronic illnesses and appear to be unrelated to the amenorrhoea. The failure of restoration of normal function at least after short-term refeeding requires further investigation. It was concluded that the amenorrhoea in anorexia nervosa is not associated with changes in prolactin secretion but is determined primarily by changes in the hypothalamic-pituitary-gonadal axis. These changes are induced largely by nutritional factors but psychological factors may also be involved.

Adolescent↗
PubMed1978

Comparative double-blind trial of mianserin hydrochloride (Organon GB94) and diazepam in patients with depressive illness.

1. The antidepressant action of mianserin was tested in a double-blind clinical trial lasting 6 weeks. Forty-six patients with moderate to severe degrees of depression were treated at random with mianserin or diazepam. Patients who failed to improve by week 3 were taken out of the trial. 2. Mianserin was more effective than diazepam in reducing scores on the Hamilton Rating Scale for depression. Fewer patients allocated to mianserin had to be withdrawn from the trial on account of failure to improve. Mianserin was more effective than diazepam in reducing symptoms of 'retarded depression' and as effective as diazepam in reducing symptoms of 'anxious depression'. 3. Mianserin did not cause any more side-effects than diazepam, very few side-effects being encountered with either drug. 4. The design of this trial on antidepressant drugs is commended on ethical grounds.

Adjustment Disorders↗
PubMed1976

The effects of clomiphene citrate on the hypothalamic-pituitary-gonadal axis in anorexia nervosa.

Serum luteinizing hormone (LH) responses to a course of clomiphene citrate were studied in eleven patients with anorexia nervosa at different stages of the illness. In malnourished patients basal levels of LH were invariably low. With the resumption of a normal weight a small but definite rise in LH levels was observed but this spontaneous response to weight gain was variable in that many patients continued to exhibit abnormally low LH levels. The response to clomiphene in terms of a rise in basal LH levels after administration of the drug, followed by a second peak of LH and subsequent menstrual bleeding, was clearly dependent in part on the patient's nutritional state. In the malnourished state the response to clomiphene was usually either absent or incomplete. After the resumption of a more normal weight, the patients invariably showed an initial rise in LH after the clomiphene, but the second LH peak and subsequent menstruation were frequently not demonstrated. Six patients maintained a normal body weight for at least six months after a course of clomiphene, but only three of them resumed cyclical menstrual bleeding. It was concluded that factors additional to the nutritional state contribute to the prolonged amenorrhoea in anorexia nervosa and that clomiphene appears to have only a limited role in the treatment and management of patients with the disorder. Some aspects of current knowledge of the endocrine mechanisms that regulate normal menstruation and of the mode of action of clomiphene are outlined. The results of the present study are discussed against this background in an attempt to elucidate further the hypothalamic disorder underlying the amenorrhoea in anorexia nervosa.

Adolescent↗
PubMedDate not supplied

Cognitive functioning, weight change and therapy in anorexia nervosa.

Anorexia nervosa is associated with impairments in cognitive function which have been hypothesized to be fundamentally attentional in nature. The current study investigated whether therapy and weight gain affect these impairments. A group of anorexics (N = 12) completed a battery of cognitive performance tasks and self-report measures of psychopathology on three occasions, over the course of 12 weeks of in-patient treatment. A non-clinical control population (N = 17) completed the same measures. The anorexics improved on all measures of psychopathology and affective state as a result of therapy. Anorexics displayed poorer recall, reaction times, and motor speed than the control subjects. Although there was a gain in weight over the course of therapy, there was no corresponding improvement in cognitive performance. Impaired task performance in anorexics was not directly related to their psychopathology or affective state.

Adolescent↗