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Biomedical subjects

R B Welbourn

Publications and source records attributed to R B Welbourn.

At least 37 records · Page 2Linked to original sources
PubMed1982

Interdigestive biliary output in man: relationship to fluctuations in plasma motilin and effect of atropine.

The fasting output of bile into the bowel was investigated in nine healthy volunteers by hepatobiliary scanning. Subjects were studied twice, on each occasion for 2.5 hours. A significant flow of radioactivity from the gall bladder to the duodenum was observed on one or two occasions during each experiment. A 32 +/- 4% mean decrease in counts over the gall bladder was recorded, indicating partial emptying of this organ in the interdigestive state. The output of bile into the bowel was found to be related to fluctuations in fasting plasma motilin levels in that a significant motilin increment (18 +/- 4 pmol/l, p less than 0.005) paralleled the appearance of radioactivity in the duodenum. The onset of gall-bladder emptying regularly preceded the peak in plasma motilin (mean: 25 +/- 2 minutes). Atropine, intravenously, 0.6 mg followed by 0.3 mg, nearly abolished both fasting biliary output and plasma motilin fluctuations. Thus, bile output appears to occur frequently in fasting humans, but our data do not allow any conclusions as to the possible causal relationship between fasting gall-bladder emptying and release of motilin. Cholinergic influences appear to be of importance in the regulation of interdigestive biliary output in man.

Adult↗
PubMed1982

Phaeochromocytomas of the bladder.

Phaeochromocytomas of the bladder are rare, only about 100 cases having been reported previously. Four adults with these lesions have been managed at Hammersmith Hospital in the past 10 years. Three patients had hypertension, together with syncopal attacks and/or headaches, induced by micturition. The fourth patient presented with haematuria. After control of blood pressure and localization of the tumours by various combinations of cystoscopy, intravenous urography, venous sampling, ultrasound, angiography and computerized coaxial tomography (CT scanning), 3 patients underwent partial cystectomy, and the fourth pelvic exenteration. Two patients were apparently cured of the disease, but 2 were not. One developed modal metastases and recurrence of hypertension after 18 months and one rapidly developed metastases in the lungs and elsewhere. Effective therapy probably requires a high index of suspicion in diagnosing the condition and possibly an aggressive surgical and radiotherapeutic policy.

Adult↗
PubMed1980

The effect of pirenzepine on meal-stimulated gastrointestinal hormones.

The effects of pirenzepine on the plasma concentrations of gut hormones in the fasting and postprandial states were studied in six healthy subjects. On separate days and in random order, 10 mg pirenzepine, in 2 ml of solvent, or 2 ml saline (0.15 mol/l) were given intravenously 30 min before a standard normal breakfast (2220 kJ). Pirenzepine was not found to affect basal or postprandial levels of insulin, glucagon, gastric inhibitory peptide (GIP), neurotensin, vasoactive intestinal peptide (VIP) or somatostatin. The basal concentration of pancreatic polypeptide (PP) was lowered (p less than 0.05) and the postprandial elevation reduced, though not significantly. While the basal concentration of motilin was also suppressed (p less than 0.05), the postprandial elevation remained unchanged following pirenzepine. The release of enteroglucagon was reduced significantly in the basal and postprandial states (p less than 0.05 and p less than 0.025 respectively). The postprandial gastrin response was prolonged slightly, but insignificantly, by pirenzepine. It is concluded that pirenzepine does not exert any major or unexpected actions on the hormonal control of digestion.

Adult↗
PubMed1980

Influence of intravenous pirenzepine on gastric acid and pepsin in man.

Patients with dyspepsia were asked to volunteer for two gastric secretion tests preceded by a single intravenous injection of pirenzepine 10 mg in the one and 0.9% saline in the other (in random order). In each test gastric secretion was aspirated continuously. 0.9% saline was infused intravenously for 30 minutes followed by insulin 0.15 micrograms/kg-h for 90 minutes, saline for 30 minutes and finally pentagastrin for 90 minutes in doses of either 6, 1, 0.5 or 0.25 micrograms/kg-h. Gastric samples were analysed for volume, pH, titratable acidity and pepsin. Basal outputs of acid and pepsin were not altered by pirenzepine. Insulin-stimulated acid output was significantly reduced (p less than 0.05) from a mean of 32.7 to 22.6 mmol/h (-31%). The mean percentage reduction was 16%. Acid and pepsin outputs after pentagastrin 0.25-6 micrograms/kg-h were not significantly altered by this dose of pirenzepine.

Adult↗
PubMed1980

The biochemical diagnosis, localization and follow up of phaeochromocytoma: the role of plasma and urinary catecholamine measurements.

The diagnosis of phaeochromocytoma is dependent on combined biochemical and radiological investigation, the biochemical studies being performed initially and followed later by both non-invasive and invasive radiological techniques. In 23 patients studied, a selection of biochemical studies allowed diagnosis and accurate localization of phaeochromocytoma in 16. In some patients, tumour localization was confirmed by radiographic methods. Biochemical estimations of catecholamines and/or metabolites in urine and/or plasma were also performed during and after operation, and these measurements allowed monitoring of the completeness of tumour excision, and of the possibility of recurrence, in both the short term and the long term follow up of patients.

Adrenal Gland Neoplasms↗
PubMed1979

Pancreatic apudomas.

Pancreatic apudomas are not common but are frequently curable. Thus, it is important for every clinician to be fully aware of the varied clinical syndromes that suggest their presence. The availability of specific radioimmunoassays has made confirmation of the diagnosis relatively simple. Advances in the techniques for staining the different cell types have led to the recognition that many of these tumors are mixed, and that the general term "pancreatic apudoma" is appropriate. Pancreatic endocrine tumors, as examples to "nature's experiments," have yielded considerable insight into the possible physiologic effects of the various peptides they produce. It is to be hoped that further study of tumors such as the somatostatinoma and PPoma may yield further information about these enigmatic compounds.

Animals↗
PubMed1979

Cushing's syndrome due to adrenocortical carcinoma - a comphrensive clinical and biochemical study of patients treated by surgery and chemotherapy.

Four post-menopausal women had Cushing's syndrome due to adrenal cortical carcinomas. Comprehensive analyses of blood and urinary steroids showed that although the steroid profiles differed between patients, the pattern in each patient remained almost constant as the disease progressed, or remitted due to therapy. Elevations of serum testosterone and oestradiol were commensurate with the extent of virilisation, and the urinary output of aldosterone was associated with the severity of hypertension. A new finding was that all had substantially increased urinary free deoxycorticosterone. Complete surgical removal of the primary tumours was impossible but when most of the tumour tissue was removed, full clinical and biochemical remissions were obtained for a short time in 2 patients. One patient obtained a clinical and biochemical remission from op'DDD. In another patient the drug caused reduction both in blood pressure and in urinary aldosterone excretion, but there were unpleasant side effects. A third patient could not tolerate op'DDD. Metyrapone therapy produced neither clinical nor biochemical improvement in 3 patients. The mean duration of survival was 17 months after the first symptoms and 10 months from the date of operation. Despite advances in drug therapy, adrenal cortical carcinoma remains a lethal disease. Biochemical screening of multiple steroids offers a means of early diagnosis and disease monitoring. Extensive surgical removal of the tumour offers the best chance of a clinical and biochemical remission.

17-Ketosteroids↗
PubMed1978

Cushing's syndrome: 20 years after adrenalectomy.

The long term results (over 20 years) of our first 13 patients treated by adrenalectomy for Cushing's syndrome are described. Twelve survived operation and 5 of these died within 5 years, but thereafter the expectation of life of the treated patients was similar to that of the general population. At 20 years 7 patients were alive and 6 were well. If modern therapeutic measures to control adrenocortical function before operation has been available 20 years ago, some of the early deaths might have been prevented.

Adolescent↗
PubMed1978

Cure of intractable watery diarrhoea by excision of a vipoma.

A 56-year-old man suffered unexplained watery diarrhoea for 5 years which ultimately produced quadraparesis due to serve potassium depletion. All investigations were negative until demonstration of elevated plasma vasoactive intestinal peptide (VIP) indicated the presence of a vipoma. Removal of the VIP-producing tumour tissue--an adrenal ganglioneuroma--resulted in complete cure. Plasma VIP measurement is thus a valuable diagnostic screen in such cases and can be used to predict prognosis and to guide further therapy.

Adrenal Gland Neoplasms↗
PubMed1978

Clinically silent gross hypergastrinaemia from a multiple hormone-secreting pancreatic apudoma.

A patient is described who had a malignant pancreatic islet cell apudoma secreting corticotrophin (ACTH) and melanocyte-stimulating hormone (MSH), both of which were clinically active, and very large quantities of immunoreactive gastrins, which were biologically active but clinically silent (normal gastric acid secretion and no peptic ulceration). The presence of parietal cell antibodies, with no increase in the plasma concentrations of hormones which can inhibit gastric acid secretion (secretin, GIP and VIP), suggests that many of the of the parietal cells may have been blocked by the autoantibodies.

Adenoma, Islet Cell↗
PubMed1978

G cell population of the gastric antrum, plasma gastrin, and gastric acid secretion in patients with and without duodenal ulcer.

Estimates of the G cell population were made in 24 resected human pyloric antra from counts of cells in multiple samples and from measurements of antral size. Measurements had been made previously in 20 subjects of acid output (basal and after pentagastrin) and in 10 subjects of plasma gastrin (basal and after insulin + bicarbonate). G cells were most dense near the pylorus, but their circumferential distribution was even. The G cell populations ranged from 8 to 15 (mean 10) million in four control patients and from 3 to 43 (mean 18) million in 15 patients with duodenal ulcer. Those with recurrent ulcer after vagotomy had either a low G cell count and incomplete vagotomy, or a high G cell count and apparently complete denervation. Two patients with hypergastrinaemia and duodenal ulcer had moderate (29 X 10(6)) or marked (56 X 10(6)) excesses of G cells. 'G cell hyperplasia' may represent the extreme end of the normal range of G cell numbers in the antrum, and can be assessed by semi-quantitative grading of G cell hyperplasia in antral biopsies. There were significant direct correlations between antral area and G cell density, between peak acid output and G cell population, and between basal plasma gastrin and G cell density (but not population). We suggest that, in patients with duodenal ulcer, acid and gastrin secretion are interrelated and that both are related to the masses of parietal cells and of G cells.

Cell Count↗