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Biomedical subjects

A C Watson

Publications and source records attributed to A C Watson.

At least 37 records · Page 2Linked to original sources
PubMed1988

Recovery from glucocorticoid inhibition of the responses to corticotrophin-releasing hormone.

We have characterized the recovery of the hypothalamic-pituitary-adrenal (HPA) axis from inhibition by short-term prednisolone administration. Prednisolone was given in a dosage averaging 25 mg at 12 h intervals orally for up to 2 weeks to adult volunteers. Human corticotrophin releasing hormone (hCRH) tests were performed at 0901 h using a bolus injection of 1 microgram/kg before and 24-48 h after discontinuing the prednisolone. In the initial control study, hCRH stimulated a two-fold rise in plasma ACTH and a 30% rise in plasma cortisol within 30 min (ACTH rose from 18.5 +/- 4.5, SEM, pg/ml to 36.5 +/- 12.6 pg/ml and cortisol from 415 +/- 58 to 531 +/- 69 nmol/l in response to hCRH. One dose of prednisolone had no effect on the ACTH or cortisol response to hCRH administered 24 h later. Twenty-four hours after discontinuing a 1 week course of prednisolone, baseline plasma ACTH (3.9 +/- 0.6 pg/ml) and cortisol (146 +/- 17 nmol/l) were markedly suppressed, as was the cortisol response to hCRH (peak 198 +/- 22). However, the plasma ACTH response to hCRH was not significantly suppressed. Forty-eight hours after discontinuing prednisolone, the recovery of ACTH secretion was complete (baseline 10.9 +/- 4.2, peak 36.4 +/- 14.8 pg/ml), but the cortisol response to hCRH was still depressed (peak 294 +/- 66 nmol/l). Recovery from a 2 week course of prednisolone had similar characteristics except plasma cortisol was depressed more profoundly. Plasma dehydroepiandrosterone (DHA) during hCRH tests and dehydroepiandrosterone sulphate (DHAS) paralleled plasma cortisol.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenocorticotropic Hormone↗
PubMed1986

The rapid ovarian secretory response to pituitary stimulation by the gonadotropin-releasing hormone agonist nafarelin in sexual precocity.

We evaluated a GnRH agonist (GnRHa) as a potential single stimulus to both pituitary and ovarian secretion in 13 girls with true precocious puberty. We compared the GnRH agonist [6-D-(2-naphthyl)alanine]GnRH acetate (nafarelin, Syntex) administered as a single sc injection of 0.2 microgram/kg to GnRH infused iv in a dose of 2 micrograms/kg X h for 3 h and assessed the response of plasma steroid intermediates in estradiol (E2) biosynthesis. Although serum LH and FSH levels increased to similar peaks 3 h after commencing GnRH and nafarelin testing, they rose faster (P less than 0.01 at 1 h) and remained elevated longer (P less than 0.05 at 24 h) after nafarelin administration. At the third hour of testing with either agent, LH and FSH rose 8.8- and 3.4-fold, respectively (P less than 0.001 vs. baseline), whereas the rise in E2 was inconsistent and averaged only one third (P less than 0.02). However, plasma E2 increased later after nafarelin, but not after GnRH, rising from a baseline level of 30 +/- 6 (+/- SEM) to 115 +/- 13 pg/ml at 24 h (P less than 0.001). The least E2 response to nafarelin at this time was 150%. This rise is probably an underestimate of the maximum E2 rise, since a 6-fold response to nafarelin was found at 12 h in patients sampled then. Measurement of steroid intermediates from progesterone and 17 alpha-hydroxypregnenolone to E2 indicated that the response to nafarelin was typical of normal ovarian follicular secretion. That is, plasma levels of the intermediates in E2 biosynthesis rose less than 2-fold, and only the elevations in androstenedione, from 58 +/- 10 to 78 +/- 16 ng/dl (P less than 0.05), and estrone, from 14 +/- 3 to 38 +/- 7 pg/ml (P less than 0.02), at 24 h were significant. The greater effectiveness of nafarelin than GnRH in stimulating E2 secretion appears to be related to the more prolonged gonadotropin response. The magnitude, consistency, specificity, and rapidity of the gonadotropin and E2 responses to nafarelin indicate that this is a promising agent for rapidly testing pituitary and ovarian function simultaneously.

Child↗
PubMed1985

Malignant melanoma in Scotland 1979-1983.

1318 cases of primary malignant melanoma of the skin first presenting in Scotland in the years 1979-83 and registered with the Scottish Melanoma Group are described. The annual age-adjusted incidence rate is 4.75 per 100 000 for females and 2.77 per 100 000 for males. Incidence rose by an annual average of 2.5% over the five-year period. The female: male ratio was 2:1, and 48.5% of all cases were of the superficial spreading histogenetic variety. Five-year survival rates for the patients registered in 1979 confirm the prognostic value of the tumour-thickness (Breslow) measurement. They were 93% for patients with tumours less than 1.5 mm thick (39% of patients), 67% for those with tumours 1.5-3.49 mm thick (30%), and 37% for those with tumours thicker than 3.5 mm (31%). This study shows that methods for early recognition of thin tumours should be encouraged.

Adolescent↗
PubMed1982

The surgical treatment of microtia: a long-term review of 17 patients.

Fourteen children were reviewed approximately 3 1/2 years after surgical reconstruction of the pinna had been completed. Seven had unilateral microtia and seven bilateral microtia, including four caused by thalidomide. Using objective criteria the cosmetic results were disappointing. Treatment entailed protracted hospitalisation, numerous operations and produced adverse emotional and educational sequelae. Nearly all the children covered their ears by growing their hair long. Attempts by the ENT department to improve hearing in the children with bilateral microtia had been disappointing. Three other children who were not treated although they had been referred for surgery were also reviewed. The problems of reconstructive surgery for microtia and the indications for treatment are discussed. It is suggested that reconstruction may be inadvisable for children who have bilateral anotia or associated deformities and who have an unstable family background.

Abnormalities, Multiple↗
PubMed1981

Moment analysis of the flow-time curve after breathing gases of different densities.

In an attempt to improve methods of determining the site of airway narrowing we have tried using a heavier than air gas mixture (SF6/02) in addition to the more widely used lighter than air gas mixture (HE/O2). Response to varying inspired gas density has been assessed by means of change in mean transit time (MTT) as well as by means of change in flow rate at 50% of vital capacity (Vmax50). The possibility that derivatives of second moment analysis of the flow time curve reflect the presence of small airway disease is studied. The reproducibility of response to SF6/O2 breathing was better than that to He/O2 breathing. However there was no correlation between response to these two gas mixtures in either normal subjects or in patients with asthma. The response of MTT to He/O2 breathing correlated with the response to Vmax50 and although no more reproducible, there are theoretical advantages in using MTT as the method of assessment. The derivative of the second moment of the flow-time curve. COV, did not correlate with flow rate response to He/O2 breathing.

Adult↗
PubMed1975

The use of Opsite, a vapour permeable dressing, on skin graft donor sites.

A trial of a moisture vapour permeable dressing (Opsite) on split-skin graft donor sites of 53 patients has been carried out. The main advantages were freedom from pain, early healing and lack of bulky dressings. The disadvantages were post-operative leakage of fluid from under the Opsite and fragility of the newly healed donor site for the first few days. An occlusive dressing for the first 48 hours post-operatively is suggested to help overcome the leakage problem, and care of the healed donor site, with particular emphasis on not removing Opsite that is adherent to it, is stressed.

Bandages↗