Search PubMed⌕ Search

Biomedical subjects

A E Cowen

Publications and source records attributed to A E Cowen.

At least 19 recordsLinked to original sources
PubMed1993

The role of ERCP and endoscopic sphincterotomy in the era of laparoscopic cholecystectomy.

The advent of laparoscopic cholecystectomy (LC) has led to some controversy regarding the best method of managing bile duct calculi. This paper reviews the cases of 38 patients who underwent LC and endoscopic retrograde cholangiopancreatography (ERCP), from a series of 600 consecutive laparoscopic cholecystectomies. Twenty-nine patients had ERCP performed pre-operatively because of suspicion of choledocholithiasis. Duct stones were confirmed in eight patients. Recent or current jaundice was the best predictor of bile duct stones. Nine patients had ERCP done postoperatively because of duct stones seen on operative cholangiography. In two patients bile duct cannulation was not possible and a third procedure, open duct exploration, was necessary. Techniques in laparoscopic management of duct stones are improving and the role of ERCP and sphincterotomy should be limited to jaundiced patients or those with proven bile duct stones in whom laparoscopic procedures have been unsuccessful.

Adult↗
PubMed1992

Gastrointestinal endoscopy: an accurate and safe primary diagnostic and therapeutic modality.

OBJECTIVE: To review the place of gastrointestinal endoscopy in the management of upper and lower gastrointestinal disorders. DATA SOURCES: We reviewed articles on endoscopy reported over two decades. A Medline search complementing our experience and knowledge of the literature was used to identify the articles. STUDY SELECTION: Papers were selected which focused on indications, comparison with radiology, including clinical outcome measures, and complications. One hundred papers, including those from radiology journals, were reviewed. DATA EXTRACTION: Results of studies are referenced as appropriate. DATA SYNTHESIS AND CONCLUSIONS: Endoscopy allows direct visualisation of the mucosa of the upper gastrointestinal tract, colon and terminal ileum. Subtleties of colour change, vascular pattern abnormalities and scarring are easily detected at endoscopy and are often of diagnostic importance. Endoscopy also provides access for tissue biopsy and allows a wide variety of therapeutic interventions. Traditionally barium studies have been the first step in the evaluation of many gastrointestinal symptoms and still retain cost advantages over endoscopy. However, endoscopy is frequently more sensitive and specific than barium studies. Costs associated with incorrect diagnoses may undermine the apparent cost benefits of barium studies. Advances in endoscopic design have allowed wider therapeutic options and increased safety. Gastrointestinal endoscopy should now be the first line of investigation where diagnostic precision is required or where therapeutic intervention is likely.

Barium Sulfate↗
PubMed1992

Infection and endoscopy: who infects whom?

Infection is one of the major hazards of endoscopic procedures and is the commonest complication of endoscopic retrograde cholangio-pancreatography (ERCP) causing death. Prevention of endoscopy-associated infections is based on adequate cleaning and disinfection regimens. Scrupulous mechanical cleaning is fundamental; even prolonged chemical disinfection will be ineffective if cleaning has not been adequate. Special measures are required to prevent ERCP-related infections. It is important to recognize various special circumstances that increase a patient's susceptibility to infection and to administer antibiotic prophylaxis when appropriate.

Cross Infection↗
PubMed1991

Successful treatment of two patients with gastric antral vascular ectasia 'watermelon stomach' using endoscopic Nd-YAG laser therapy.

Two patients with gastric antral vascular ectasia--'watermelon stomach'--successfully treated with endoscopic Nd-YAG laser are described. This condition is an uncommon cause of iron deficiency anaemia due to chronic blood loss and is usually managed by antrectomy. Endoscopic therapy with Nd-YAG laser offers an effective and safe alternative to surgery particularly in the elderly poor-risk patient.

Aged↗
PubMed1989

Early postoperative endoscopic sphincterotomy for retained common duct stones.

The results of endoscopic sphincterotomy in 30 patients with retained common bile duct stones and a T-tube in situ following surgical exploration of the common bile duct are presented. Successful stone extraction was achieved in 27 cases (90%). There was one death, which was not procedure related. Early postoperative T-tube cholangiography is advocated and if necessary sphincterotomy can be safely performed 1 week following surgery. This approach has advantages in shortening hospital stay and minimising patient discomfort.

Adult↗
PubMed1986

A comparison of colloidal bismuth subcitrate tablets and ranitidine in the treatment of chronic duodenal ulcers.

In a randomized, endoscopically controlled trial, the effects of colloidal bismuth subcitrate (CBS) tablets on the healing of chronic duodenal ulcers were compared with those of ranitidine (R). 38 patients were originally allocated to the CBS group and 37 to ranitidine. There were 5 dropouts in each group. Of 33 patients given CBS, 25 (75%) showed complete ulcer healing by 4 weeks and 30 (91%) by 8 weeks. Of the 32 patients given ranitidine, 28 (87%) showed complete ulcer healing by 4 weeks and 30 (94%) by 8 weeks. There was no significant difference between these results. Symptom resolution was similar in both groups and no significant adverse effects were noted.

Adult↗
PubMed1984

Endoscopic sphincterotomy for common bile duct calculi.

A series of 74 patients having endoscopic sphincterotomy for common bile duct calculi is reported. Complete stone extraction was achieved in 53 cases (72%). Seventeen of 21 patients with retained calculi following recent biliary surgery had successful extractions (80%). Of 30 patients having had a cholecystectomy, 21 (70%) were successful, but only 15 of 23 patients with obstructive jaundice and no previous biliary surgery had the ducts cleared of calculi. Failure was due to multiple stones in the duct, or calculi too large to pass through the sphincterotomy. Endoscopic sphincterotomy is advocated in patients with obstructive jaundice due to stones, moving to early surgery should it prove unsuccessful. The results in patients with a T-tube in situ are comparable to extraction of the calculi along the T-tube tract.

Adult↗
PubMed1984

A clinical approach to improving survival in colorectal cancer.

The majority of large bowel cancers arise from benign adenomatous polyps. The identification of groups at high risk, the effective investigation and surveillance of these groups, together with a more discerning clinical approach to patients with bowel symptoms provides the best hope of cure.

Adult↗
PubMed1983

Comparison of ranitidine and cimetidine in the treatment of chronic gastric ulcer. A double-blind trial.

The aim of the study was to compare the effectiveness of ranitidine and cimetidine in accelerating the healing of chronic gastric ulcer. 44 outpatients with endoscopically proven gastric ulcer whose duration of symptoms was greater than 4 weeks and who were without major systemic disease were studied. Patients were randomly allocated to receive either ranitidine, 150 mg twice a day or cimetidine, 200 mg three times a day and 400 mg at night for 4 weeks. If the ulcer had not healed, treatment was continued for a further 4 weeks, when patient assessment and endoscopy were repeated. By 4 weeks, 13 of 22 patients taking ranitidine (59%) and 14 of 22 patients taking cimetidine (64%) had healed (p2 = 1.0, 95% confidence interval - 20%, 38%). At 8 weeks, 91% on ranitidine and 91% on cimetidine had healed (p2 = 1.0, 95% confidence interval - 18%, 18%). Symptomatic improvement was similar with both drugs. Smoking did not influence healing rates. There were no major side effects with either medication. It is concluded that ranitidine and cimetidine are of similar efficacy in accelerating the healing of chronic gastric ulcer.

Adolescent↗
PubMed1981

Colonoscopic polypectomy.

Seven hundred and forty-one colonic polyps have been removed by colonoscopic polypectomy during 300 examinations. Up to 36 polyps were removed at a single examination. Colonoscopic treatment of villous adenomas to 7 cm has been successfully performed in elderly and infirm patients. There were no deaths or incidents of perforation and the only significant complications were two secondary haemorrhages requiring transfusion. The presence of a polyp was not definitely reported in 40% of barium enema X-ray examinations carried out within three months of polypectomy. Double contrast X-ray examinations were significantly more sensitive in the detection of polyps. Colonoscopic polypectomy is a safe and effective technique. All colonic polyps should be removed by this technique after diagnosis.

Adenoma↗
PubMed1979

Efficacy of cimetidine and tri-potassium di-citrato bismuthate (De-Nol) in chronic gastric ulceration: a comparative study.

Sixty patients with benign chronic gastric ulcer were treated in a controlled clinical trial to assess the relative efficacy of cimetidine and tri-potassium di-citrato bismuthate (De-Nol). Patients were assigned at random either to cimetidine or to De-Nol treatment after initial endoscopic diagnosis. Healing was assessed endoscopically after six weeks by an endoscopist who had no knowledge of the patients' treatment. Consumption of analgesic preparations (both for medical and for non-medical reasons), of other anti-inflammatory agents, and of alcohol and cigarettes was recorded. Of the 57 patients who were reassessed at six weeks, 30 had been assigned to De-Nol and 20 of these patients (66%) had completely healed; 27 patients had been assigned to cimetidine and 17 of these (63%) had also completely healed. Those patients who regularly ingested more than four analgesic preparations a day healed less frequently, but this effect was not statistically significant. There was no significant difference between cimetidine and De-Nol in the initial healing of chronic gastric ulceration. The choice of therapy for chronic gastric ulceration will depend on cost, patient acceptance, and data from studies of more complex therapeutic regimens.

Analgesics↗
PubMed1979

Liver disease associated with chronic arsenic ingestion.

The association of chronic liver disease with long-standing arsenic ingestion is well documented, although the spectrum and incidence of liver disease due to arsenic remain uncertain. We report two patients with chronic liver disease and arsenical skin changes that followed previous chronic arsenic ingestion. One patient developed macronodular cirrhosis and the other non-cirrhotic portal hypertension with perisinusoidal fibrosis. The latter patient developed a primary liver cell cancer. There is only one previously reported case of malignant hepatoma in a non-cirrhotic liver complicating chronic arsenicism. Lack of awareness of this uncommon but well described cause of chronic liver disease may account for a small proportion of patients with "cryptogenic" liver disease. Previous arsenic administration should be considered as a cause of chronic liver disease, especially when typical skin changes or internal neoplasia develop.

Arsenic↗
PubMed1978

Determinants of fasting and postprandial serum bile acid levels in healthy man.

The relationship between serum levels of conjugates of cholic acid measured by radioimmunoassay, bile acid absorption, and hepatic clearance was studied in order to define the determinants of fasting and postprandial serum bile acids in healthy man. Acute or chronic interruption of the enterohepatic circulation caused a significant decrease in basal serum levels of cholyl conjugates, while liquid or solid meals caused a marked and reproducible increase in serum cholyl conjugates. A temporal correlation was demonstrated postprandially or after intravenous cholecystokinin between intestinal transit of bile acids and simultaneous changes in levels of serum cholyl conjugates. Finally, the plasma disappearance of intravenously injected cholylglycine was shown to be unaffected by serum levels of endogenous cholyl conjugates. These data are consistent with the interpretation that, in the presence of normal hepatic function, the major determinant of serum bile acids is their rate of intestinal absorption.

Adult↗
PubMed1977

The changing clinical presentation of coeliac disease in adults.

A diagnosis of coeliac disease was confirmed in 57 patients referred to a gastroenterology clinic over a 5 1/2-year period. Although diarrhoea was present in two-thirds of the patients, this was the major symptom leading to referral in less than half of them. When present, diarrhoea was usually intermittent and frequently not typical of steatorrhoea. Symptoms were of less than six months' duration in half the patients, but a review of the past and family history strongly indicated the possibility of coeliac disease in 39 of the 57 patients. A high spontaneous abortion rate during pregnancy was noted. The frequent absence of the classical features of malabsorption, diarrhoea with typical steatorrhoea and chronic debility was noted. All screening tests for malabsorption were found to be unreliable and their routine use was rarely justified. A random serum folate and carotene assay proved as valuable as more expensive and troublesome tests. It is stressed that in any case in which there is a clinical suspicion of this diagnosis, a small intestinal biopsy should be undertaken.

Abortion, Spontaneous↗
PubMed1977

Bile salt metabolism. I. The physiology of bile salts.

Bile salts are synthesized in the liver from cholesterol, conjugated with glycine or taurine and secreted in bile with cholesterol and lecithin. The molar concentrations of these three lipids determine solubility of cholesterol in bile. Within the gastrointestinal lumen bile salts play an essential role in lipid absorption and faty transport. An efficienct entero-hepatic circulation maintains hepatic bile salt secretion and provides a "feed-back" control of the bile salt and cholesterol metabolism. Potentially hepatotoxic lithocholic acid formed in the intestinal lumen by bacterial action on chenodeoxycholic acid is sulphated in the liver thus decreasing intestinal reabsorption. The total faecal excretion of bile salts balances hepatic synthesis and represents a major catabolic path in cholesterol metabolism.

Animals↗
PubMed1977

Bile salt metabolism. II. Bile salts and disease.

Alterations of bile salt metabolism have been shown in numerous diseases. Liver damage results in elevated serum bile salt concentrations which may be useful as a sensitive index of hepatocellular disease. Changes in the relative proportions of the individual bile salts in serum occur with cholestasis. Urinary excretion of bile salts, largely in the form of sulphates, increases as a compensatory mechanism. Ileal disease or resection causes bile salt melabsorption. The increase in colonic bile salts produces a watery diarrhoea while the decrease in duodenal levels may cause steatorrhoea. Cholelithiasis may result from alteration in the relative proportions of cholesterol, lecithin and bile salts in bile. The mechanism apparently differs in various conditions predisposing to gallstone formation. A primary alteration of bile salt metabolism has been postulated in several other conditions. Considerable interest centres on the importance of metabolites of bile salts in the pathogenesis of colonic carcinoma. Chenodeoxycholic acid is a successful though costly treatment for selected patients with cholesterol gallstones. Bile salt binding agents, such as cholestyramine, are extremely useful especially in the control of pruritus in patients with cholestasis.

Animals↗
PubMed1977

Radioimmunoassay of bile acids: development, validation, and preliminary application of an assay for conjugates of chenodeoxycholic acid.

A rapid, sensitive, precise radioimmunoassay for conjugates of chenodeoxycholic (chenic) acid has been developed and validated. Immunogen was prepared with chenylglycine couples to bovine serum albumin, emulsified in Freund's complete adjuvant, and injected intracutaneously in rabbits. Antibodies of moderate titer (used at 1:7500 final dilution) were obtained. Tracer of high specific activity was prepared by reductive tritiation of delta11-chenylglycine. The binding step required 1 hr at room temperature; separation of bound tracer was achieved by addition of ammonium sulfate. The limit of sensitivity of the assay was about 20 nmoles per liter, and the lower limit of the working range was 0.4 mumole per liter. The assay was validated by measuring levels in samples of fasting state serum to which known amounts of chenylglycine had been added; the assay was also validated by means of gas-liquid chromatography on sera from jaundiced patients. The median fasting state serum level in 56 Caucasians and blacks was 0.9 mumole per liter (upper limit of normal (95% confidence) being 2.3), which is in the same range as that reported by others using gas-liquid chromatography. A 5- to 10-fold increase in levels of chenyl conjugates was observed 1 hr after the ingestion of a liquid meal in healthy persons.

Ammonium Sulfate↗