PubMed Health⌕ Search

Biomedical subjects

W M Drake

Publications and source records attributed to W M Drake.

At least 55 records · Page 3Linked to original sources

Emergency and prolonged use of intravenous etomidate to control hypercortisolemia in a patient with Cushing's syndrome and peritonitis.

We report the emergency and prolonged use of etomidate to control circulating cortisol levels in a patient with Cushing's syndrome secondary to ectopic ACTH production from a pancreatic islet cell tumor. Duodenal perforation and peritonitis complicated an episode of salmonella septicemia, precluding the use of conventional oral medical adrenolytic therapy. Endogenous cortisol secretion was abolished by parenteral etomidate, allowing serum cortisol levels to be controlled with an iv infusion of hydrocortisone over an 8-week period in intensive care before definitive pancreatic surgery.

Adenoma, Islet Cell↗

Optimizing growth hormone replacement therapy by dose titration in hypopituitary adults.

Although growth hormone (GH) replacement therapy is increasingly utilized in the management of adult hypopituitary patients, optimum dosing schedules are poorly defined. The use of weight-based or surface area-based dosing may result in overtreatment, and individual variation in susceptibility on the basis of gender and other factors is now being recognized. To optimize GH replacement and to explore further gender differences in susceptibility, we used a dose titration regimen, starting at the initiation of GH replacement therapy, in 50 consecutive adult-onset hypopituitary patients, and compared the results with those in 21 patients previously treated using a weight-based regimen. Titrated patients commenced GH 0.8 IU/day subcutaneously (0.4 IU/day if hypertensive or glucose tolerance impaired). Serum insulin-like growth factor I (IGF-I) was measured at 0, 2, 4, 6, 8, 10, and 12 weeks in all patients. Serum IGF binding protein 3 and acid labile subunit were measured at the same time points in 17 patients (8 male, 9 female). Patients were reviewed every 4 weeks and the dose of GH increased, if necessary, to achieve a serum IGF-I level between the median and the upper end of the age-related reference range. There was no significant difference between mean serum IGF-I at 2 and 4 weeks, or between 6 and 8 weeks, indicating that the full effects of a change in dose are evident within 2 weeks of that change. Maintenance doses were significantly higher in females than males [1.2 (0.8-2.0) vs. 0.8 (0.4-1.6) IU/day; median (range); P < 0.0001], and the median time to achieve maintenance dose was significantly shorter in males [4 (2-12) vs. 9 (2-26) weeks; P < 0.0001]. Median maintenance dose was lower overall than in a group of 21 patients initially commenced on GH using a weight-based dosing schedule, with subsequent adjustment of dose during clinical follow-up [1.5 (0.4-3.2) IU/day; P = 0.02]. Reduction in waist measurement and waist to hip ratio at 6 and 12 months was similar in females (P < 0.001) and males (P < 0.01). Well-being improved significantly after 3 months of GH therapy (14.2 +/- 5.9 vs. 7.4 +/- 4.5 SD; P < 0.0001), and there were no gender differences. Adult Growth Hormone Deficiency Assessment (AGHDA) scores at 6 months were similar to maintenance scores in patients commenced on weight-based regimens. Measurements of ALS and IGFBP-3 added no useful extra information to IGF-I in managing the dose titration. The practical scheme outlined for dose titration of GH replacement resulted in rapid achievement of lower maintenance doses than those achieved using conventional weight-based regimens without loss of efficacy. It was particularly important in female patients who demonstrated decreased overall sensitivity to GH and required higher doses to achieve the same effects as males. This constitutes the first report of a uniform titration regimen based on a defined target range of serum IGF-I in a large patient cohort.

Adolescent↗

Dose-related effects of growth hormone on IGF-I and IGF-binding protein-3 levels in non-islet cell tumour hypoglycaemia.

Mesenchymal tumours are a well recognised cause of spontaneous hypoglycaemia. The mechanism is thought to relate to hypersecretion by tumour cells of high molecular mass insulin-like growth factor-II (pro-IGF-II), with consequent suppression of growth hormone (GH) secretion. The use of recombinant human (rh)GH has been reported to alleviate hypoglycaemia in non-islet cell tumour hypoglycaemia, and the mechanism is thought to relate to GH-mediated increments in serum levels of IGF-binding protein-3 (IGFBP-3), thereby reducing the bioavailability of IGF-II. We report the effect of increasing doses of rhGH on the clinical condition and serum IGF-I and IGFBP-3 levels in two patients with solitary pleural fibrous tumours causing severe hypoglycaemia. Hypoglycaemia was successfully alleviated in each patient although, despite using large doses of rhGH, the observed increments in IGFBP-3 were only modest. We postulate that the beneficial effects of rhGH in this situation are likely to be multifactorial and not simply related to increments in serum IGFBP-3 levels.

Aged↗

Intracardiac metastases from neuroendocrine tumours.

We report three cases of intra-cardiac metastases from neuroendocrine tumours of the carcinoid type. One presented in a manner identical to a left atrial myxoma; in one patient a left atrial mass was noted during investigations for weight loss and a lung mass; and in the third, two right ventricular deposits were detected on echocardiography when a patient with a disseminated GHRH-secreting tumour was investigated for dyspnoea. Although to our knowledge this is only the third report of these lesions, we believe that this represents a form of carcinoid heart disease that is distinct from the valvular abnormalities seen in some patients with carcinoid syndrome. Neuroendocrine metastases should be considered in the differential diagnosis of intra-cardiac tumours.

Adult↗

Metastatic parathyroid carcinoma in the MEN2A syndrome.

We report a patient with a metastatic parathyroid carcinoma and medullary carcinoma of the thyroid. This patient represents a variation of the multiple endocrine neoplasia syndrome (MEN) type 2A. There was no evidence of a phaeochromocytoma. The case illustrates the difficulties that may be encountered in localising the source of PTH secretion; the patient underwent four unsuccessful exploratory operations of the neck and mediastinum before further investigations revealed a single metastatic deposit of parathyroid carcinoma involving the first thoracic vertebra. PCR amplification and sequencing of the RET oncogene from the metastatic parathyroid carcinoma and genomic DNA revealed a heterozygous mutation (Cys634Tyr) in exon 11, as has previously been described to occur in MEN 2A. In addition, loss of tumour heterozygosity was demonstrated at loci from chromosomes 1, 2, 3p, 13q and 16p. This represents the first report of a parathyroid carcinoma in a MEN2A patient, in which the multiple allelic deletions are consistent with the generalised losses observed in aggressive tumours.

Carcinoma↗

Pulmonary artery occlusion by tuberculous mediastinal lymphadenopathy.

Two cases of tuberculous mediastinal lymphadenopathy are presented in which the clinical features mimicked those of pulmonary embolism, causing striking abnormalities on radionuclide scintigraphy. It is concluded that tuberculous mediastinal lymphadenopathy should be included in the differential diagnosis of reduced lung perfusion due to proximal pulmonary artery occlusion.

Adult↗

Small bowel intussusception and brown bowel syndrome in association with severe malnutrition.

Brown bowel syndrome is a rare condition characterized by deposition of lipofuscin in the smooth muscle cells of the gastrointestinal tract. The number of reported cases is small, but all are associated with malabsorptive states. Despite these small numbers, there is considerable evidence that vitamin E deficiency is important etiologically. We report here the case of a severely malnourished [body mass index 11.7 kg/m (2): normal range 20-25 kg/m (2)] 31-yr-old black male with a longstanding history of alcohol abuse, who was on anti-tuberculosis therapy. The patient presented with an acute abdomen and was found, at operation, to have a mid-ileal intussusception. Histological examination of the resected specimen demonstrated lipofuscin accumulation consistent with brown bowel syndrome, but no tumor. Subsequent investigations revealed no significant quantities of vitamin E in the blood and pancreatic steatorrhea. However, deficiency of other fat-soluble (vitamin A and D) and water-soluble vitamins (vitamin C and thiamine) also were detected. This report supports the association of brown bowel syndrome with vitamin E deficiency but cannot exclude the compounding effects of protein calorie malnutrition, multiple vitamin deficiencies, and chronic alcohol toxicity.

Abdomen, Acute↗

Primary gastric lymphoma presenting with vitamin B12 deficiency and achlorhydria.

Gastric lymphoma is an uncommon condition, usually presenting with epigastric pain and/or dyspepsia. There is now good evidence that infection with Helicobacter pylori (Hp) is etiologically important. We report here a case of primary gastric lymphoma presenting with vitamin B12 deficiency anemia and achlorhydria in which there was evidence of previous, but not current, infection with Hp. Vitamin B12 deficiency was proven to be due to intrinsic factor deficiency. To our knowledge, this condition has not previously been reported.

Achlorhydria↗