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Biomedical subjects

A I Davidson

Publications and source records attributed to A I Davidson.

At least 19 recordsLinked to original sources
PubMed1998

Characterization of dihydropyrimidine dehydrogenase in human colorectal tumours.

Dihydropyrimidine dehydrogenase (DPD) is the rate-limiting enzyme for degradation of 5-fluorouracil (5-FU). DPD activity is highly variable in liver and peripheral mononuclear cells (PMNCs) and it has not been well studied in human tumours. Characterization of DPD in colorectal cancer is of clinical interest through its role in the regulation of 5-FU, the main chemotherapeutic agent used in this disease. Therefore, DPD activity was analysed in colorectal tumour and adjacent normal tissue from 63 patients, including three liver metastasis. DPD activity was highly variable in all tissues studied (coefficient of variation 43-61%) and was higher in normal tissue than in tumour. The tumour-normal activity ratio ranged from 0.19 to 3.32 (median 0.76). PMNC DPD activity was available for 57 patients and was correlated with tumour activity (r(s) = 0.29, P < 0.001). A higher correlation was observed between PMNCs and tumour samples that were both obtained in the morning (r(s) = 0.49), consistent with circadian variation in DPD activity. Normal tissue DPD activity was not correlated with either tumour (r(s) = 0.11) or PMNC activity (r(s) = -0.06). This study provides the first analysis of DPD activity in colorectal cancer and illustrates the large degree of variation in tumour activity. The tumour-normal activity ratio results suggest that elevated tumour DPD can play a role in 5-FU resistance through increased inactivation in tumour cells, but is an uncommon event in colorectal tumours. The results support the use of PMNCs for monitoring tumour DPD activity, particularly when circadian variation is taken into account. As a large degree of the variation in tumour DPD activity is not explained by PMNC activity, more accurate alternatives are needed before DPD activity can be used for targeting 5-FU therapy.

Adult↗
PubMed1997

Diverticular disease in patients under 50 years of age.

Sigmoid diverticular disease, when it occurs in a young age group, may follow a more aggressive course with a higher incidence of complications than in elderly. The mode of presentation and management in 77 patients under 50 years of age presenting with sigmoid diverticular disease over a 6-year period is described. Surgery for complications (peritonitis, abscess, bowel obstruction, fistula and haemorrhage) was performed in 18 (23%) individuals. Colonic resection was carried out in 14 (78%) of the operated group with primary anastomosis in six patients and Hartmann's procedure in eight patients. The mortality (30 day) was zero. Nineteen (25%) of the entire group, and 12 (67%) of those undergoing surgery had been previously hospitalized with a complication of diverticular disease. The recurrent nature and frequency of serious complications in this group, suggests that elective surgery should be considered if an acute infective episode is successfully managed conservatively.

Adult↗
PubMed1997

Vesico-colic fistulae in the Grampian region: presentation, assessment, management and outcome.

Over a 12-year period, 67 patients presented with a vesico-colic fistula. The mean age was 69 years (range 19-96 years), with symptoms predominantly referred to the urinary tract. Cystoscopy and barium enema confirmed the presence of a fistula in 60 and 44% of patients respectively. A computerized tomography (CT) scan, used in only seven patients, revealed the fistula in each case. The underlying pathology included diverticular disease (62%), carcinoma (27%) and inflammatory bowel disease (6%). Fifty-one patients proceeded to surgery, of whom 32 (63%) had a sigmoid/recto sigmoid resection with primary anastomosis, and 13 (25%) a Hartmann's procedure. A diverting colostomy alone was employed to palliate cases of widespread carcinoma. No patient subsequently had the Hartmann's reversed. In addition to colonic resection, 48 (92%) patients had a simultaneous bladder procedure, varying from simple oversew in 32 (70%) patients to cystectomy and ileal conduit in three (6%). Wedge excision with primary bladder closure was practised in 12 (24%). Fistula recurrence occurred in seven (14%) patients, and the 30-day mortality was 10%. Surgery for vesico-colic fistula has an appreciable morbidity and mortality, yet if offers the only hope of achieving permanent symptomatic control.

Adult↗
PubMed1996

Gastric lymphoma in Grampian Region: presentation, treatment and outcome.

Forty cases of gastric lymphoma presenting in Grampian Region (1974-91) were reviewed to examine the effects of changing ideas in the fields of chemotherapy, gastric surgery and diagnostic techniques, as well as the impact of Helicobacter pylori. Presentation was non-specific, and the diagnosis was made pre-operatively in only 12 cases. Survival was related to tumour size, staging (Ann Arbor), and grade, with a crude 5-year survival of 49%. Helicobacter pylori was found in all specimens reviewed. Patients who underwent "potentially curative' surgery followed by adjuvant therapy had the best survival (85% at 5 years). There remains a need for larger studies to define the best treatment for this uncommon condition.

Adult↗
PubMed1994

Loop ileostomy fixation: a simple technique to minimise the risk of stomal volvulus.

Turnbull's "loop" ileostomies is a routinely performed procedure in the management of a variety of colorectal problems. Mechanical and functional complications occur with both permanent and temporary ileostomies, however they are more common with the loop than with the end (Brooke) variety. With the advent of restorative proctocolectomy with pouch formation, and the documented benefit of simultaneous temporary faecal diversion, the incidence of such complications will rise. Bowel obstruction, requiring laparotomy in the interval before stoma closure, is more commonly associated with the loop ileostomy. A loop stoma is routinely brought out directly through the abdominal wall, with little or no fixation or closure of the lateral space. However, anti-mesenteric fixation, as described here, minimises the risk of volvulus by widening the attachment of the adjacent ileum to the parities, creating a broader fulcrum. Since adopting this simple technique, we report no complications in over 30 loop ileostomies, "fixed" by this technique and followed up for a minimum of 4 years. Where applicable, no difficulty was encountered with stoma closure, either by a transverse single layer serosubmucosal technique, or as a minimal resection with end to end anastomosis (sewn or stapled), following bowel mobilisation. This technique should minimise the frequency of obstructive events, and we recommend it's routine use.

Adolescent↗
PubMed1988

Operative management of tubulovillous neoplasms of the duodenum and ampulla.

Six patients are described to illustrate the operative management of tubulovillous neoplasms of the duodenum. Pancreaticoduodenectomy is appropriate for associated invasive carcinoma. Transduodenal submucosal excision of tubulovillous neoplasms with resection and reconstruction of the distal bile and pancreatic ducts if necessary is a satisfactory alternative when the neoplasm has not penetrated the muscularis mucosae.

Adenoma↗
PubMed1987

Epidemiology and outcome of acute pancreatitis.

Acute pancreatitis in North-East Scotland from January 1983 to December 1985 was examined. The criteria for diagnosis were a serum amylase greater than 1000 units/l with a consistent clinical presentation, or acute pancreatitis confirmed at laparotomy or post mortem. All serum amylase assays were performed in one regional laboratory. The commonly used diagnostic coding search for pancreatitis yielded only half the cases found. We identified 378 episodes of acute pancreatitis (196 males and 182 females). The mean annual incidence for first attacks of acute pancreatitis was 242 per million of the population. The commonest aetiology was biliary tract disease (30 per cent of males and 53 per cent of females). Alcohol related pancreatitis occurred in 26.5 per cent of males but only 3 per cent of females. Complications included 26 pseudocysts, 11 pancreatic abscesses, 9 patients with respiratory failure, 11 patients with renal failure and 6 patients with disseminated intravascular coagulation.

Acute Disease↗
PubMed1987

Antibiotic prophylaxis in non-perforated appendicitis of childhood: tetracycline lavage compared with peroperative intravenous cefuroxime and metronidazole.

Eighty-four cases of non-perforated appendicitis in children were randomly allocated to receive either oxytetracycline lavage alone or oxytetracycline lavage plus peroperative intravenous metronidazole and cefuroxime. The wound infection rate with the oxytetracycline lavage alone was 4.4% compared with 7.7% when metronidazole and cefuroxime were added. These rates were not significantly different. This study supports the use of oxytetracycline lavage alone as effective prophylaxis against wound infection in non-perforated appendicitis of childhood.

Adolescent↗
PubMed1987

Haemolytic-uraemic syndrome presenting as an acute abdomen.

Haemolytic-uraemic syndrome (HUS) may present with symptoms and signs suggestive of an acute surgical condition of the abdomen. The patient described was admitted with clinical features sufficient to warrant operation but later proved to have HUS.

Abdomen, Acute↗
PubMed1981

Intravenous radionuclide cystography for the detection of vesicorenal reflux.

Intravenous radionuclide cystography using a single intravenous injection of 99mtechnetium diethylenetriaminepentaacetic acid, provides information on individual kidney function, coarse anatomy and vesicorenal reflux. This study investigates the effectiveness of intravenous radionuclide cystography in detecting reflux. In 58 children intravenous radionuclide cystography detected 53 ureters with reflux compared to 32 detected by voiding cystography. This difference was investigated further with patients in whom other test suggested reflux. While there was no statistically significant difference for patients having pyelonephritis or hydronephrosis, intravenous radionuclide cystography detected significantly more ureters with reflux in patients with abnormal ureteral orifices or infected urine and, therefore, predisposed to reflux. Intravenous radionuclide cystography is a more comprehensive and sensitive test for vesicorenal reflux than voiding cystography.

Adolescent↗
PubMed1981

Evidence for an immune complex vasculitis in neonatal necrotising enterocolitis.

Despite many attractive hypotheses, neonatal necrotising enterocolitis (NNEC) remains a disease of unknown aetiology. By means of the immunofluorescent direct sandwich technique we have demonstrated immune complex deposition in the small vessels of the diseased bowel wall. We believe this is the first report of evidence of an immunological reaction occurring in this disease.

Antigen-Antibody Complex↗