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Biomedical subjects

J Dawson

Publications and source records attributed to J Dawson.

At least 181 records · Page 10Linked to original sources
PubMed1985

Stimulation and inhibition of secretion by phorbol myristate acetate in different cell types.

In washed human platelets and in HL60 granulocytes phorbol myristate acetate (PMA, 1-2000nM) synergised with threshold concentrations of secretogogues to induce a sustained maximum secretory response. Likewise, superoxide production from HL60 cells maintained a maximal response at PMA concentrations between 30-300nM. At concentrations up to 10nM PMA also augmented calcium ionophore, A23187, stimulated histamine release from rat peritoneal mast cells. However, in the mast cell PMA concentrations above 10nM reduced maximum histamine release in a dose-dependent manner.

Animals↗
PubMed1985

A controlled trial of fixed versus tailored calorie intake in patients receiving intravenous feeding after abdominal surgery.

Excessive intravenous calorie intakes have been shown to increase fat deposition and CO2 production with deleterious results. A controlled trial has therefore been performed to determine whether there is clinical benefit from tailoring calorie intake of intravenously fed patients to the patient's metabolic expenditure. Twenty patients requiring intravenous feeding after abdominal surgery were randomly allocated to receive either (i) a constant regimen containing 2 600 calories and 15.55 g nitrogen or (ii) a varied regimen with a fixed calorie: N2 ratio of 167:1 but with the calorie intake adjusted according to the previous day's metabolic expenditure. Only one patient had a requirement of greater than 2 600 calories; there was no difference in mean RQ during intravenous feeding between the constant regimen (0.90 +/- 0.10 s.d.) and the varied regimen (0.90 +/- 0.09 s.d.) and no significant difference in peak CO2 production. Excess calorie intake over expenditure did not correlate with increased positive nitrogen balance but on the varied regimen patients receiving a higher nitrogen intake tended to be in more positive nitrogen balance. This study suggests that a fixed calorie intake of 2 600 calories per day is suitable for adult patients requiring intravenous feeding after abdominal surgery but currently prescribed nitrogen intakes may be suboptimal.

Journal Article↗
PubMed1985

Endoscopic variceal pressure measurements: response to isosorbide dinitrate.

An endoscopic pressure sensor has been evaluated in the measurement of oesophageal variceal pressure and its response to drug ingestion. The variceal pressure showed a highly significant correlation with the splenic pulp pressure (r = 0.97) in six patients with liver disease of diverse aetiology and with hepatic venous wedge pressure (r = 0.92) in eight alcoholic cirrhotic men. Intraduodenal infusion of isosorbide dinitrate in the cirrhotics produced no change in wedge pressure or endoscopic variceal pressure despite profound falls in arterial systolic pressure. Thus isosorbide dinitrate appears to be of no value in treating portal hypertension. This study establishes the endoscopic pressure sensor as a valuable tool in screening drugs in this condition.

Adult↗
PubMed1984

Glutathione biosynthesis in the isolated perfused rat lung: utilization of extracellular glutathione.

The isolated perfused rat lung catalyzed the biosynthesis of GSH when the sulfur amino acids cysteine or N-acetylcysteine, but not methionine, were supplied in the perfusion medium. The lung also had the capacity to utilize extracellular GSH for this purpose. Replenishment of intracellular GSH in perfused lungs from diethylmaleate-treated rats was pronounced even at 25 microM GSH in the perfusion medium. The utilization of extracellular GSH is probably primarily through extracellular break-down and resynthesis rather than direct uptake as indicated by the inhibitory effect of the gamma-glutamylcysteine synthetase inhibitor, buthionine sulfoximine and the gamma-glutamyl transferase inhibitor, anthglutin. The results indicate that the lung in addition to the kidney may utilize circulating plasma GSH.

Acetylcysteine↗
PubMed1984

Colonic Crohn's disease and use of oral contraception.

The prevalence of use of oral contraception before the onset of disease was established in 100 consecutive women attending follow up clinics for inflammatory bowel disease. A significant excess of women with Crohn's disease confined to the colon had taken oral contraceptives in the year before developing symptoms (10/16 (63%] compared with women with small-intestinal Crohn's disease (12/49 (24%); p less than 0.02) and women with ulcerative colitis (3/35 (9%); p less than 0.0005). When the patient groups were matched for age and year of onset of disease usage of oral contraception before the onset of disease was still more common among women with isolated colonic Crohn's disease (9/12, 75%) than among those with ulcerative colitis (2/12 (17%); p less than 0.02) and was also more common than would be expected from reported figures for oral contraception in England and Wales (31.4% of women aged under 41; p less than 0.005). A survey of current patient records showed that isolated colonic disease was at least twice as common among women with Crohn's disease (63/218, 29%) compared with men (25/181, 14%; p less than 0.001). These data support the suggestion made previously that oral contraceptives may predispose to a colitis that resembles colonic Crohn's disease.

Adolescent↗
PubMed1984

Unusual vascular tumour of the scalp in association with lymphoid aggregates: a variant of angiolymphoid hyperplasia?

A 51-year-old mason presented with a large tumour on his scalp which had developed over the previous 2 years. Histological examination showed the presence of large vessels with muscular coats some of which appeared to be venules and others arterioles. They had markedly swollen cuboidal endothelial cells and a surrounding mononuclear cell infiltrate which in areas formed lymphoid follicles some of which had germinal centers. There was no evidence of tissue or blood eosinophilia. The unusual clinical and histological features of this case are emphasized and the nosology of this rare condition is discussed.

Angiolymphoid Hyperplasia with Eosinophilia↗
PubMed1984

Gastrointestinal regulatory peptide storage granule abnormalities in jejunal mucosal diseases.

The mucosal concentrations of seven regulatory peptides and the density properties and integrity of their storage granules have been studied in mucosal biopsies from the human jejunum in eight gastrointestinal disease states and compared with normal controls. In diseases with associated mucosal inflammation (coeliac disease, Crohn's disease with jejunal involvement, postinfective tropical malabsorption, and common variable immunodeficiency) there was a selective increase in fragility of the gastric inhibitory polypeptide (GIP) and somatostatin storage granules. The gastrin, motilin, enteroglucagon, secretin, and vasoactive intestinal polypeptide granules had normal properties in these conditions. In diseases in which diarrhoea occurred in the absence of changes in jejunal mucosal histology (irritable bowel syndrome, pancreatic insufficiency, jejuno-ileal bypass for morbid obesity, and purgative abuse) there were no abnormalities of the storage granules. Increased mucosal concentrations of all peptides except vasoactive intestinal polypeptide (VIP) were found in coeliac disease and selective increases of VIP found in Crohn's disease, motilin in the irritable bowel syndrome and gastrin and GIP in pancreatic insufficiency. It is suggested that the storage granule abnormalities in the diseases with abnormal mucosal histology are secondary to the inflammatory changes.

Gastric Inhibitory Polypeptide↗
PubMed1984

Effect of ranitidine and cimetidine on gastric ulcer healing and recurrence.

Fifty-eight patients with endoscopically confirmed benign gastric ulceration were randomly allocated to treatment with 150 mg ranitidine twice daily, placebo matching ranitidine twice daily, or 200 mg cimetidine three times daily and 400 mg at night. Patients were endoscoped at monthly intervals for up to 3 months, the endoscopist being unaware of the treatment. Significantly more ulcers (p less than 0.05) had healed after 2 months of ranitidine (14 of 18, 78%) and cimetidine (17 of 20, 85%) than with placebo (9 of 20, 45%; p less than 0.05) and after 3 months of ranitidine (15 of 18, 88%) and cimetidine (18 of 20, 90%) than with placebo (11 of 20, 55%; p less than 0.05). Forty-eight patients with healed ulcers were randomly allocated in a double-blind prophylactic study to receive 150 mg ranitidine at night or matching placebo. After 6 months recurrent ulcers were found in 2 of 24 (8%) of patients receiving ranitidine and 10 of 24 (42%) of patients receiving placebo (p less than 0.05). These data indicate that H2-receptor antagonists are significantly better than placebo in healing gastric ulceration and that ranitidine and cimetidine are equally effective. Ranitidine is significantly superior to placebo in preventing gastric ulcer recurrence.

Cimetidine↗
PubMed1983

The automated metabolic profile.

The automated metabolic profile provides the physician with a comprehensive review and graphic display of the patient's nutritional status, energy expenditure, substrate utilization, and nutritional requirements. A paramedical assistant performs all data acquisition, anthropometric and indirect calorimetric measurements. Data reduction is performed on a standard microcomputer system utilizing off-the-shelf peripherals. A standardized graphic sheet is used for the printout. The automated metabolic profile is utilized before initiation of nutritional therapy and subsequently to record the progress. Its use optimizes the clinical management of patients needing both ventilatory and nutritional support. By its use, total parenteral nutrition can be tailored to the requirements of the critically ill patient.

Anthropometry↗
PubMed1983

A unique apudoma producing the glucagonoma and gastrinoma syndromes.

A patient is described who presented with a 10 year history of intermittent peptic ulcer symptoms and a 3 year history of an undiagnosed skin rash. Investigations indicated raised plasma levels of gastrin, glucagon and pancreatic polypeptide. A single tumour was localised to the pancreas and resected. The tumour had the typical histology of an apudoma, and contained cells which stained for gastrin, glucagon, pancreatic polypeptide and neurotensin.

Aged↗