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Biomedical subjects

W E Thomas

Publications and source records attributed to W E Thomas.

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

Endoscopic screening for premalignant changes 25 years after gastrectomy: results of a five-year prospective study.

Sixty-three partial gastrectomy patients an average 20 years after surgery were reviewed by endoscopy and biopsy in 1977. No cases of invasive carcinoma were found. The patients were then divided into two groups. Those with moderate epithelial dysplasia (13 patients) were reviewed at 6-12 monthly intervals. One patient developed severe dysplasia but none developed an invasive carcinoma. The remaining patients with either no or mild dysplasia were offered endoscopy after 5 years and 24 agreed. Of the 12 patients with no dysplasia at the outset: 5 still had no dysplasia 5 years later, 3 had mild dysplasia and 4 now had moderate dysplasia. There were 12 with mild dysplasia at the first endoscopy, 9 remained unchanged at the review and 3 had moderate dysplasia. If dysplastic changes in gastric mucosa are pre-malignant, progression to invasive carcinoma would appear to be slow. Even 25 years after gastrectomy only a modest deterioration in the grade of dysplasia was found and no invasive cancer.

Aged↗
PubMed1984

Radionuclide evaluation of acute scrotal disease.

Technetium-99m sodium pertechnetate scintigraphy is an established method for evaluating organ perfusion and can be applied to the investigation of suspected testicular ischaemia due to acute torsion. One hundred and six consecutive scrotal investigations have been analysed qualitatively and quantitatively using a computer-based comparison of the perfusion slopes over each testis. Decreased vascularity on the symptomatic side only occurs in torsion and quantitative analysis is needed to detect it reliably. Increased vascularity on the symptomatic side can usually be detected qualitatively and occurs in orchitis, tumours, trauma and resolved torsion. Distinction between the causes of increased vascularity is aided by the clinical data. A halo of increased activity surrounding a relatively cold centre was seen in chronic torsion, some tumours and hydrocoeles. The test is both sensitive and specific for acute torsion but its usefulness is limited if it is not available at all hours. The test is useful, also, in confirming a diagnosis that does not require emergency operation and in identifying chronic torsion which is an indication for contralateral orchidopexy.

Acute Disease↗
PubMed1984

Suppression of somatostatin release by duodenogastric reflux in dogs.

The effect of duodenogastric reflux on systemic and portal venous blood concentrations of somatostatin has been studied in the dog. Duodenogastric reflux suppressed somatostatin concentrations in both systemic and portal venous blood, but this did not occur when bile alone was diverted into the stomach. The suppression was also much less marked when truncal vagotomy accompanied the reflux. These findings suggest that altered somatostatin activity may play a part in the production of the pathophysiological changes occurring in clinical conditions such as peptic ulceration, in which there is an increase in duodenogastric reflux.

Animals↗
PubMed1984

Intussusception of invaginated Meckel's diverticulum.

Two middle-aged patients are reported who came to laparotomy with a presumptive diagnosis of small bowel tumour. There was no overt evidence of small bowel obstruction in either case. They were found at laparotomy to have intussusception of an invaginated Meckel's diverticulum. This condition should be considered in the differential diagnosis of ileal tumours.

Angiography↗
PubMed1984

The hormonal changes produced by duodenogastric reflux.

Serum systemic and portal venous blood levels of secretin, vasoactive intestinal polypeptide (VIP), gastric inhibitory peptide (GIP), somatostatin, insulin and pancreatic polypeptide (PP) have been examined in dogs with and without surgically produced duodenogastric reflux. Serum levels of secretin, VIP, insulin and PP showed no change, but reflux caused a significant elevation of GIP levels and a suppression of somatostatin levels in both systemic and portal venous blood.

Animals↗
PubMed1984

Acute pseudo-obstruction of the colon.

Nineteen patients presenting with pseudo-obstruction of the colon are described. Thirteen were female and the mean age was 65.7 years (48-82). Five cases appeared idiopathic but the remainder were associated with either intercurrent disease, surgery or trauma. Six patients underwent laparotomy, 3 for gross caecal distension and 1 subsequently died with bronchopneumonia. Thirteen patients were treated conservatively with flatus tube decompression or colonoscopy, but 3 died, 1 from a perforated caecum, 1 from a recurrent subarachnoid haemorrhage and 1 from bronchopneumonia. The high mortality of caecal perforation in this condition is stressed, and gross radiological caecal distension with overlying tenderness is an indication for urgent decompression.

Acute Disease↗
PubMed1984

The possible role of duodenogastric reflux in the pathogenesis of both gastric and duodenal ulcers.

Duodenogastric reflux was assessed scintigraphically in normal subjects (n = 20) and in patients with duodenal (n = 15) or gastric ulcers (n = 14). Reflux was graded 0-4 according to degree and was minimal in the control group (0.25 +/- 0.12) (mean +/- SEM), but significantly increased in 11 out of 15 patients with duodenal ulceration (1.33 +/- 0.25) and in 12 out of 14 patients with gastric ulceration (1.86 +/- 0.29) (P less than or equal to 0.0025). Gastric mucosal biopsies taken at endoscopy showed changes of gastritis which correlated well with the degree of reflux. It is suggested therefore that duodenogastric reflux may play a significant role in the pathogenesis of some peptic ulcers, and may be responsible for many of the pathophysiological changes seen in these patients.

Biopsy↗
PubMed1984

The clinical assessment of duodenogastric reflux by scintigraphy and its relation to histological changes in gastric mucosa.

Fifty-seven patients undergoing routine or review gastroscopy had multiple gastric biopsies taken and assessed histologically for gastritis, metaplasia and dysplasia. Duodenogastric reflux was graded scintigraphically by BIDA Scanning. Patients with dysplastic changes in the gastric mucosa (n = 33) had a higher mean grade of reflux 2.1 +/- 0.21 (mean +/- SEM) than patients with no dysplasia (1.1 +/- 0.24: P less than 0.0025). Patients with metaplasia (n = 33) had an increased mean grade of reflux of 2.0 +/- 0.19 compared with patients without metaplasia (1.3 +/- 0.29: P less than 0.05), but there was no significant difference in degree of reflux between patients with and without gastritis. When the grade of reflux was plotted against increasing degrees of mucosal abnormalities, there appeared to be a positive correlation between duodenogastric reflux and severity of mucosal change.

Biopsy↗
PubMed1984

The problems associated with scintigraphic assessment of duodenogastric reflux.

Imaging with 99mTc-IDA derivatives is a recognised technique for assessing duodenogastric reflux. A study of 150 consecutive scans has revealed a number of limitations in its use. Anatomical definition of the stomach on static imaging and computed data analysis of reflux, were often complicated by overlap by the left lobe of the liver and the duodenal-jejunal flexure. Delineation of the antrum was poor, and as it is so close to the duodenal cap and hepato-biliary activity, transient small volumes of reflux may not have been detectable. Quantification of massive reflux was easily reproducible but computer analysis of small volumes of transient reflux was often uninterpretable. A proposed clinical grading of reflux takes into account the intensity, extent and duration of reflux, and can be matched with other clinico-pathological features.

Computers↗
PubMed1984

Sympathetic orchidopathia.

Subfertility has recently been shown to follow unilateral torsion of the spermatic cord in more than half the patients studied. Since the anatomical anomaly that predisposes to torsion (a high investment of the tunica vaginalis) is commonly bilateral, there could be an associated congenital defect in spermatogenesis on each side. Alternatively, autoantigens escaping from the ischaemic or 'exciting' testis could trigger an immunological response which damages the contralateral or 'sympathising' testis. Demonstration of an autoallergic (sympathetic) orchidopathia, analogous to sympathetic ophthalmia, would fundamentally alter the management of testicular torsion.

Animals↗
PubMed1983

Mechanism of action of Bacillus thuringiensis var israelensis insecticidal delta-endotoxin.

Bacillus thuringiensis var israelensis delta-endotoxin protein active against mosquitoes was inactivated by prior incubation with lipids extracted from Aedes albopictus cells. Experiments with lipid dispersions and multilamellar liposomes showed that the toxin binds to phosphatidyl choline, sphingomyelin and phosphatidyl ethanolamine provided these lipids contain unsaturated fatty acids. Phosphatidyl serine binds toxin less efficiently and phosphatidyl inositol, cardiolipin, cerebroside and cholesterol show no affinity for the toxin. The results suggest an insecticidal mechanism in which interaction of toxin with affinity for the toxin. The results suggest an insecticidal mechanism in which interaction of toxin with specific plasma membrane lipids causes a detergent-like rearrangement of the lipids, leading to disruption of membrane integrity and eventual cytolysis.

Aedes↗
PubMed1983

Diagnosis and outcome of testicular torsion.

In a prospective study of 80 patients with acute testicular pain, static and dynamic scans of the scrotum were obtained by radionuclide imaging. Seven patients with acute testicular torsion were identified by gross reductions in isotope uptake. Enhanced uptake (indicating hyperaemia) was seen in 37 patients with acute epididymitis, testicular tumour or resolved torsion. Late torsion and some tumours demonstrated a "halo' sign, with central necrosis and a peripheral increase in blood supply. A group of 22 patients with previous orchidopexy for torsion was reviewed 2-5 years postoperatively. In 15 the previously twisted testis was greater than 10 per cent smaller than its opposite member and 12 patients showed severe abnormalities of seminal analysis. Hormonal profiles were generally normal. Retention of testes damaged by ischaemia may risk autoimmunization against spermatogenesis.

Adolescent↗
PubMed1983

Arterial injuries in two Bristol hospitals from 1974 to 1980.

Fifty-eight patients with 63 peripheral arterial injuries coming to the Bristol Royal Infirmary and Frenchay Hospital, Bristol over a six-year period from 1974-1980 were studied. The majority followed road traffic accidents, and over 70 per cent occurred in teenagers and young adults. Arterial reconstructions were undertaken in 51 cases (81 per cent) with concomitant fasciotomy in 3. Pulse volume recordings and on table arteriograms were used to detect and correct 2 reconstructions which were initially less than ideal. Forty-eight of 51 reconstructions were patent at follow up.

Accidents, Traffic↗
PubMed1983

Bacillus thuringiensis var israelensis crystal delta-endotoxin: effects on insect and mammalian cells in vitro and in vivo.

Bacillus thuringiensis var israelensis parasporal crystal delta-endotoxin was purified by ultracentrifugation on a discontinuous sucrose gradient. Native delta-endotoxin crystals showed no detectable toxicity in the vitro and in vivo systems that are described. By contrast alkali-solubilized crystal delta-endotoxin caused rapid cytological and cytopathological changes in Aedes albopictus, Choristoneura fumiferana 63 CF1, Spodoptera frugiperda and Trichoplusia ni cell lines as observed by phase-contrast microscopy and vital staining. Mouse fibroblasts, primary pig lymphocytes and three mouse epithelial carcinoma cell types showed a similar response to the alkali-soluble crystal delta-endotoxin. In addition the soluble crystal delta-endotoxin protein caused haemolysis of rat, mouse, sheep, horse and human erythrocytes. Intravenous administration of the alkali-soluble crystal delta-endotoxin to Balb. c mice at a dose rate of 15-30 micrograms of protein per gram body weight resulted in rapid paralysis followed by death within 12h. Subcutaneous inoculation of 15-30 micrograms of protein per gram body weight resulted in death of suckling mice in 2-3 h. The alkali-solubilized crystal delta-endotoxin was not toxic however, when administered per os. A comparison is made with a similar alkali-soluble fraction from the parasporal crystal delta-endotoxin of B. thuringiensis var kurstaki. With the exception of the Lepidopteran cell line, Choristoneura fumiferana 63 CF1, this soluble crystal delta-endotoxin protein showed no in vitro or in vivo toxicity, and no haemolytic activity.

Animals↗
PubMed1983

The functional and morphological effects of duodeno-gastric reflux and their relation to peptic ulceration.

The functional and morphological effects of duodeno-gastric reflux have been studied in the dog. Reflux causes hypersecretion of acid to pentagastrin and a hypergastrinaemic response to a standard meal, associated with antral gland hyperplasia. It is suggested that these changes are mediated by suppressed somatostatin activity, and that they may play an important part in the pathogenesis of peptic ulceration.

Animals↗
PubMed1983

Vascular surgical audit-arterial reconstructions and amputations for lower limb ischaemia.

There were 750 arterial reconstructions and 2134 major amputations in hospitals within the South West Regional Health Authority (SWRHA) from 1974-1978, according to a Hospital Activity Analysis (HAA) based survey of all patients undergoing these operations for atherosclerotic limb ischaemia. Those undergoing arterial reconstruction fared better than amputees in terms of hospital mortality (5.2% vs. 21%) and length of hospital stay (21.4 days vs. 47 days). Comparison of the HAA results with case records and operating theatre books at Bristol Royal Infirmary showed a failure-of-inclusion rate of 10% for arterial reconstructions and 9.3% for amputations. There was a difference in the proportion of arterial reconstructions to major amputations (2.5:1) at Bristol Royal Infirmary compared with SWRHA hospitals (1:3), but hospital stay and operative mortality were similar.

Amputation, Surgical↗