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Biomedical subjects

M H Wheeler

Publications and source records attributed to M H Wheeler.

At least 91 records · Page 5Linked to original sources
PubMed1984

Extrathyroidal sites of autoantibody synthesis in Graves' disease.

Several potential sites of thyroid autoantibody production have been investigated using tissue obtained at thyroidectomy for Graves' disease. Spontaneous thyroglobulin and microsomal antibody synthesis was measured using a plaque forming cell assay or a short term culture system coupled to a direct enzyme linked immunoassay (ELISA); these techniques allow the evaluation of lymphocyte populations which have been activated in vivo. Lymphocytes from the cervical lymph nodes, thyroid and bone marrow all contributed to autoantibody production; in contrast no synthesis was demonstrated using cells obtained from the thymus or peripheral blood. Long term culture of the lymphocytes confirmed these findings. The effect of anti-thyroid treatment, with radioiodine, drugs or surgery, on autoantibody production in Graves' disease must be viewed in the light of these results.

Adult↗
PubMed1983

Effect of intravenous aprotinin (Trasylol) on the healing of experimental colonic anastomoses in the rabbit.

A randomized controlled trial to assess the effect of intravenously administered Trasylol on the healing of experimental colonic anastomoses in the rabbit has been performed. Before undergoing a standard left colonic resection and anastomosis, the animals received intravenous Trasylol (80,000 KIU). Postoperatively 160,000 KIU were given in divided doses per day for 3 days. Control animals received saline placebo. The mean bursting pressure of the anastomoses in the Trasylol-treated group was 47.7 +/- 3.0 mm Hg compared with 37.5 +/- 3.3 mm Hg for the control group (p less than 0.05). The mean difference in collagen content of the anastomosis compared to the resected specimen was +1.25 +/- 0.50 micrograms/mg and -1.02 +/- 0.47 microgram/mg for Trasylol and placebo, respectively (p less than 0.005). In this model intravenous Trasylol produces a significant elevation of the bursting pressure and a significant improvement in the collagen content of the anastomosis. This may be the result of collagenase inhibition.

Animals↗
PubMed1983

Collagenase inhibition in the healing colon.

A randomized controlled trial was performed to assess the effect of intravenous aprotinin (Trasylol) on the healing of experimental colonic anastomoses in the rabbit following a standard left colonic resection anastomosis. Assessment of tensile strength was by means of both bursting pressure and breaking strength. Those animals subjected to bursting pressure assessment received intravenous aprotinin 80 000 KIU (kallikrein inhibitory units) at the time of anaesthesia, and postoperatively 160 000 KIU per day given in divided doses for three days. Control animals received saline placebo. A further group of animals received a lower loading and maintenance aprotinin dose (40 000 KIU and 60 000 KIU per day respectively) with control animals receiving saline. Breaking strength was employed as the means of assessment. The mean bursting pressures were 47.7 +/- 2.9 mmHg and 37.5 +/- 3.4 mmHg for aprotinin and controls respectively (P less than 0.05). The mean difference in collagen content of the anastomosis compared to the resected specimen was +1.25 +/- 0.50 microgram/mg and -1.02 +/- 0.47 microgram/mg for aprotinin and placebo groups (P less than 0.005). The mean breaking strength in the aprotinin group was 169.6 +/- 74.5 g and 110.0 +/- 65.9 g for the saline group (P less than 0.02). The mean difference in collagen content of the anastomosis compared to the resected specimen was +0.95 +/- 0.69 microgram/mg and -1.5 +/- 0.78 microgram/mg for the aprotinin and saline groups respectively (P less than 0.05). The significant elevation of both bursting pressure and breaking strength assessments, with a significant improvement in the collagen content of the anastomoses, may be the result of collagenase inhibition following the use of intravenous aprotinin in the experimental model.

Animals↗
PubMed1982

Report of a prospective trial of dextranomer beads (Debrisan) and silicone foam elastomer (Silastic) dressings in surgical wounds.

A prospective randomized controller trial of dextranomer beads (Debrisan) and silicone foam elastomer (Silastic) dressings in open infected surgical wounds has been performed. The results indicate that the healing time for wounds treated by Debrisan (n = 25) and elastomer (n = 25) is similar, being 40.92 +/- 3.98 and 36.90 +/- 3.18 days respectively. The time taken for wounds to become pain-free was similar in both treatment groups, as was the persistence of signs in the wounds of erythema, oedema and slough. Comparison of cost reveals the elastomer dressing to be considerably cheaper than Debrisan.

Adult↗
PubMed1982

Intraoperative identification of parathyroid glands: appraisal of methylene blue staining.

Methylene blue administered intravenously in a dose of 5 mg/kg of body weight was employed as an aid to the intraoperative identification of parathyroid glands in 90 patients undergoing surgery for hyperparathyroidism. Staining occurred in 95 percent of adenomas and 86 percent of hyperplastic glands. Normal and suppressed glands stained in 71 and 70 percent of cases, respectively. There were no adverse side effects from the technique. We conclude that preoperative intravenous infusion of methylene blue is a valuable technique that facilitates identification of parathyroid tissue at operation.

Humans↗
PubMed1982

Effect of intravenous amino acids on the canine gastric mucosa.

A mixture of synthetic L-amino acids (Aminoplex 14) was infused intravenously over 4 hours in five dogs each prepared with a gastric fistula and a denervated fundic pouch. Acid and pepsin outputs from the innervated fundic pouch. Acid and pepsin outputs from the innervated gastric mucosa (gastric fistula) increased significantly after 90 minutes' infusion of amino acid. Acid output from the denervated fundic mucosa (Heidenhain pouch) was estimated by a method of intragastric titration and increased significantly only in response to intravenous amino acid infusion when the pouch was subjected to distention with 100 ml of perfusate. Blood glucose, serum gastrin, hematocrit and serum osmolality levels did not change throughout the experiments. Bolus intravenous injection of either atropine (0.15 mg/kg) or cimetidine (10 mg/kg) blocked the acid secretory response to intravenous amino acids. It is concluded that intravenous amino acids stimulate the innervated gastric mucosa to secrete both acid and pepsin. The secretory response from denervated mucosa in only obtained in the presence of fundic pouch distention. The gastric secretory response is susceptible to both atropine and histamine H2 antagonist blockade.

Amino Acids↗
PubMed1981

The effect of intravenous aprotinin (Trasylol) on intraperitoneal adhesion formation in the rat.

A randomized controlled trial to assess the effect of intravenous Trasylol on postoperative intraperitoneal adhesion formation has been performed in rats. Before undergoing a standard left colonic resection, animals received i.v. Trasylol 10 000 KIU. This dose was repeated 8-hourly for 3 days postoperatively. Control animals received saline placebo. The mean percentage circumference of the anastomosis covered with adhesions in the Trasylol group animals was 20.86 +/- 6.08 compared with 45.24 +/- 5.97 in the control group (P less than 0.01). Significantly more animals treated with Trasylol were completely free of adhesions than those receiving saline. Bursting pressures did not differ between the two groups. Intravenous Trasylol clearly inhibits intraperitoneal adhesion formation in this model.

Animals↗
PubMed1981

Effect of an intravenous infusion of aminoacids (Aminoplex 14) on gastric secretion in healthy subjects and patients with duodenal ulcers.

The effect of an intravenous infusion of an aminoacid solution (Aminoplex 14) on gastric secretion is compared in healthy subjects and in duodenal ulcer patients. The acid secretory response was twice as high in duodenal ulcer patients than in normal subjects, 60 minutes after starting the infusion. Serum gastrin levels, although initially higher in duodenal ulcer patients, showed no augmentation throughout the infusion. Blood glucose, serum osmolality and PCV estimations did not alter significantly. Serum aminoacid levels showed a pronounced rise, doubling basal values, and tended to parallel the increase in acid output. Cimetidine, administered orally, suppressed the acid secretory response to intravenous aminoacid. The marked stimulation in acid secretion following aminoacid infusion in duodenal ulcer patients was not elicited after truncal or highly selective vagotomy.

Adult↗
PubMed1981

Effect of compound 48/80 on canine gastric mucosa.

The effect of compound 48/80 on the mucosal barrier of the canine Heidenhain pouch and mast cell content of gastric mucosa has been studied. 48/80 was administered in increasing doses (0.5--2.0 mg/kg) over 5 days. 0.5 mg/kg produced signs of systemic histamine release and stimulation of acid secretion by the pouch; these effects being most marked on the 1st day and absent on the 5th. Subsequent exposure of the mucosa to sodium taurocholate produced damage to the barrier similar to that in untreated animals. Histological examination revealed no evidence of mucosal mast cell degranulation by 48/80. The results suggest that the effects of 48/80 on gastric mucosa are mediated by systemic release of histamine and that local mast cells are resistant to its action.

Animals↗
PubMed1981

The role of histamine in changes which occur in the gastric mucosal barrier with bile damage.

H1 and H2 histamine receptor antagonists were used in dogs with Heidenhain pouches during experiments in which the mucosa was damaged with sodium taurocholate. In these experiments when both antagonists were used together the usual increase in hydrogen and sodium ion flux across the mucosa was not observed, but the usual fall in transmucosal potential difference occurred. The results suggest that mucosal histamine probably mediates the changes in ionic flux across gastric mucosa which follow exposure to bile. Attempts to establish the source of this histamine were made in both rats and dogs using compound 48/80 over a period to degranulate the mast cells. Treatment with this compound did not affect the change in ionic fluxes which followed exposure to bile acid, suggesting that the source of histamine mediating changes in ionic flux is probably from tissue sites other than mast cells.

Animals↗
PubMed1979

Abnormal blood vessels in the gastric antrum: a cause of upper-gastrointestinal bleeding.

Three patients who bled from curious vascular lesions of the gastric antrum are described. Each presented with an iron-deficiency anemia. Histological examination in two of the patients demonstrated numerous ectatic submucosal vessels in the antrum, the appearances being somewhat similar to angiodysplasia of the colon. The gastric lesions were not shown by barium meal examination or angiography but gave characteristic appearances on endoscopy. We believe that Billroth I partial gastrectomy is the treatment of choice for this condition.

Aged↗
PubMed1978

Ultrastructural and chemical distinction of melanins formed by Verticillium dahliae from (+)-scytalone, 1,8-dihydroxynaphthalene, catechol, and L-3,4-dihydroxyphenylalanine.

Microsclerotia of three melanin-deficient mutants of Verticillium dahliae formed malanin from (+)-scytalone, 1,8-dihydroxynaphthalene, catechol, and L-3,4-dihydroxyphenylalanine. The melanins formed from (+)-scytalone or 1,8-dihydroxynaphthalene resembled wild-type melanin chemically and ultrastructurally, whereas the melanins formed from catechol and L-3,4-dihydroxyphenlalanine were different. This suggests that scytalone and 1,8-dihydroxynaphthalene but no catechol or L-3,4-dihydroxyphenylalanine are natural intermediates of melanin biosynthesis in V. dahliae.

Catechols↗
PubMed1977

The influence of penicillin on experimental wound contamination with staphylococci: studies with chromic catgut and monofilament nylon closure.

This study examines the ability of penicillin to eradicate or modify the pattern of infection in experimental wounds contaminated with Staphylococcus pyrogenes in the presence of chromic catgut or monofilament nylon suture. Penicillin therapy initiated within 4 days of the onset of infection was successful in eradicating infection when compared with untreated controls (P less than 0-01). Infection was modified but not eradicated in penicillin was administered from the seventh day. The response of infection to penicillin was identical in wounds containing monofilament nylon or chromic catgut over a 21-day period. Antibiotics given before wound drainage permitted healing of all chronically infected wounds even in the presence of monofilament nylon. When antibiotics were begun at the time of drainage, wound healing occurred in 50 per cent (P less than 0-01).

Animals↗
PubMed1977

The role of plastic wound drapes in the prevention of wound infection following abdominal surgery.

A randomized controlled trial has been performed to assess the value of plastic wound drapes in the prevention of surgical wound infection. One hundred and forty-four patients undergoing abdominal surgery were allocated to one of three groups; a control group (A) in which standard cloth towels were applied to the abdominal wound, group B in which an adhesive plastic drape was added and group C in which a plastic ring protector was inserted into the wound. There were 26 cases (18 per cent) of wound infection. The wound infection rate in the plastic drape groups did not differ significantly from that in the control group. Bacteriological culture from a wound swab taken at operation was positive in 32 per cent of the cases. The presence of a plastic wound drape did not influence the positive culture rate. In 68 per cent of wounds which became infected the operative swab was positive as compared with 24 per cent in those not developing a wound infection. Thirteen of the 33 patients (39 per cent) with a positive wound swab subsequently developed a wound infection. In 10 of these 13 cases of infection the operative swab permitted an accurate prediction of the organism responsible for the subsequent infection.

Abdomen↗