Search PubMed⌕ Search

Biomedical subjects

T C Northfield

Publications and source records attributed to T C Northfield.

At least 145 records · Page 8Linked to original sources
PubMed1982

Gallstone dissolution rate during chenic acid therapy. Effect of bedtime administration plus low cholesterol diet.

We have studied the dissolution rate of radiolucent gallstones from validated measurements of gallstone area derived from standardized oral cholecystography in 48 patients receiving chenodeoxycholic (chenic) acid, 15 mg/kg/day. Patients were matched in pairs according to gallstone size and randomly allocated to one of two treatment groups. Group A was given chenic acid in three divided doses at mealtimes with an unrestricted diet (the conventional regimen), and group B was given bedtime chenic acid with a low cholesterol diet. In the 24 matched pairs, the mean reduction in gallstone area at 6 months on regimen A was 36% and on B 60%. Median reductions in area were 20% and 57%, respectively (P less than 0.02). Of these matched pairs, 20 were followed at 6 month intervals for 42 months. There was a significant correlation between percentage reduction in gallstone area at 6 months and length of treatment necessary for complete dissolution (P less than 0.001). Fifty percent achieved complete dissolution by 30 months on regimen A, and by 12 months on regimen B (NS). We conclude that gallstone dissolution rate during chenic acid treatment is approximately doubled by bedtime administration plus a low cholesterol diet, thus reducing the duration and cost of treatment.

Chenodeoxycholic Acid↗
PubMed1982

Bedtime cimetidine maintenance treatment: optimum dose and effect on subsequent natural history of duodenal ulcer.

Sixty patients, whose duodenal ulcers had healed endoscopically after six weeks of treatment with cimetidine 1 g/day in divided doses, were treated with maintenance cimetidine 800 mg at bedtime for six months. Eighteen relapsed endoscopically (30%). Of the 42 still in remission, 36 then completed a six month double-blind comparison of bedtime cimetidine 400 mg and placebo. Twelve of the 19 (63%) cimetidine-treated patients and 10 of 17 (59%) placebo-treated patients relapsed within six weeks (NS). This high relapse rate on cimetidine contrasts with our earlier trial, in which the six week relapse rate was only two out of 21 (10%) on bedtime cimetidine 800 mg and 16 out of 24 (66%) on placebo (P less than 0.0005). Apart from the difference in the dose of cimetidine, both our trials used the same experimental protocol during the double-blind part of the trial. In the earlier trial, however, there was no period of pretreatment with maintenance cimetidine as in the present trial. The pattern of placebo relapse was similar in both trials. We conclude that bedtime cimetidine maintenance treatment does not alter the long-term natural history of duodenal ulcer once it has been withdrawn; and that either tolerance to cimetidine develops during long-term maintenance treatment, or that bedtime cimetidine maintenance treatment in the conventional dose of 400 mg is not as effective as 800 mg in prevention of endoscopic relapse, although it does reduce symptoms.

Cimetidine↗
PubMed1982

Minimum effective dose of chenic acid for gallstone patients: reduction with bedtime administration and low cholesterol diet.

The aim of this study was to determine whether bedtime administration and a low cholesterol diet reduce the minimum effective dose of chenodeoxycholic (chenic) acid, defined as the dose giving a mean cholesterol saturation index of 0.8. Dose response studies were carried out in 10 patients with radiolucent gallstones in a functioning gallbladder during three different treatment regimens. On each regimen, all patients received three different doses of chenodeoxycholic acid in random order for one month each. Bedtime chenic acid plus a low cholesterol diet gave the greatest reduction in saturation index. A significant dose/response relationship was found on each regimen. On the conventional regimen of mealtime chenic acid, the minimum effective dose was 14 mg/kg/day; on bedtime chenic acid it was 12.4 mg/kg/day; and on bedtime chenic acid plus low cholesterol diet it was further reduced to 8.4 mg/kg/day (p less than 0.01). There was a dose-related increase in bowel frequency, which was absent at 10.6 mg/kg/day and below. We conclude that administration of chenic acid at bedtime with a low cholesterol diet enables the minimum effective dose for gallstone dissolution to be approximately halved, thus preventing diarrhoea and reducing the cost of treatment.

Adult↗
PubMed1981

Controlled trial of argon laser photocoagulation in bleeding peptic ulcers.

The efficacy of argon laser photocoagulation in the endoscopic control of haemorrhage from peptic ulcers was tested in a controlled trial at two centres in London. Of 330 patients consecutively admitted with acute upper gastrointestinal tract haemorrhage, 76 were seen at endoscopy to have a peptic ulcer accessible to laser therapy and stigmata of recent haemorrhage. These patients were included in the trial. Identification of the exact source of haemorrhage within the ulcer crater was achieved by use of standard endoscopes with careful washing. Patients were stratified into three groups: ulcers with a visible vessel (52 total, 11 actively spurting); those without a vessel (17); and those with an overlying clot persisting after washing (7). Of the 52 patients with visible vessel, 8 of 24 treated with the laser and 17 of 28 control patients had a further haemorrhage. 7 control patients died after an episode of rebleeding, but no treated patients. Treated and control patients were well matched for other factors known to influence the case fatality rate. This is the first controlled trial to demonstrate a significant reduction in mortality by the use of a non operative treatment in patients with bleeding peptic ulcers.

Acute Disease↗
PubMed1981

Endoscopic prediction of recurrent bleeding in peptic ulcers.

We performed endoscopy within 24 hours of admission in 292 unselected patients admitted to the hospital for acute gastrointestinal hemorrhage. In 132 patients endoscopy revealed peptic ulcers, and in 117 full examination of the crater was possible. Visible vessels were identified in 56 patients (48 per cent); other stigmata of recent bleeding (such as oozing from the ulcer crater) were present in 21 (18 per cent), and no stigmata in 40 (34 per cent). Among the patients with either visible vessels or other stigmata of recent bleeding, 47 were randomly selected to be observed (without treatment) for evidence of further bleeding. Nineteen of 34 patients with visible vessels (56 per cent) had rebleeding, as compared with one of 13 (8 per cent) with other stigmata of recent hemorrhage; no patients with ulcers without visible vessels or other stigmata of recent hemorrhage bled further. We conclude that after bleeding occurs, visible vessels can be identified in a much higher proportion of ulcers than previously reported, and that rebleeding occurs almost exclusively in this type of ulcer, although only half the ulcers with visible vessels do in fact bleed further.

Endoscopy↗
PubMed1981

Effect of cimetidine on renal function in man.

1 Renal function was studied in nine patients with chronic peptic ulcer before and at repeated intervals during treatment with cimetidine (1.6g daily). 2 Plasma creatinine concentration was significantly increased on the first day after starting cimetidine, and at 3 weeks, but not at 12 weeks. Blood urea concentration was unchanged. 3. Clearances of creatinine 51Cr EDTA and 125I-hippuran were significantly reduced within 6 h of starting cimetidine. Clearances of 51Cr EDTA and 125I-hippuran returned to baseline within 3 weeks, and creatinine clearance within 12 weeks. 4 Urinary creatine excretion was significantly increased at 3 weeks, but there was no significant change in urinary creatinine excretion, or in serum creatine phosphokinase concentration. 5. These observations suggest that cimetidine causes an early but short-lived fall in glomerular filtration rate (GFR) and effective renal plasma flow. The later rise in plasma creatinine was unaccompanied by any change in GFR, and may have been due to competition by cimetidine for renal tubular handling. 6 Caution should be exercised when administering cimetidine to patients with pre-existing renal failure.

Cimetidine↗
PubMed1981

Gallstones.

Explore the source record for details and available documents.

Adult↗
PubMed1980

Postprandial gall-bladder emptying in patients with gall stones.

Gall-bladder emptying in response to a standard meal was assessed in 34 patients with radiolucent gall stones and 34 matched controls. Percentage gall-bladder emptying, derived from volume measurements made on standardised oral cholecystography, was significantly higher at 15 minutes in the patients than the controls (mean +/- SE of mean 38.0 +/- 3.7% v 28.0 +/- 3.8%). This difference was maintained at 30 and 60 minutes. It is concluded that postprandial gall-bladder emptying is increased in patients with cholesterol gall stones, and that this may be the cause of the small bile-acid pool found in these patients.

Cholelithiasis↗
PubMed1980

Gall-bladder sensitivity to cholecystokinin in patients with gall stones.

Gall-bladder sensitivity to cholecystokinin (CCK) was determined by dynamic cholescintigraphy in 18 patients with radiolucent gall stones and 18 matched controls during an infusion of CCK in which the rate of infusion was increased. In 10 of the matched pairs the patient was more sensitive than the control, in one the control was more sensitive, and in seven no difference was detected (p = 0.012). It is concluded that patients with cholesterol gall stones have increased gall-bladder sensitivity to CCK, and that this may be important in the pathogenesis of this disease.

Cholecystokinin↗
PubMed1979

Optimal timing of doses of chenic acid in patients with gall stones.

Sixteen patients with gall stones were treated with chenic acid (14-16 mg/kg/day) given at three different times in random order for one month each. Before treatment the mean (+/- SE of mean) cholesterol saturation index (SI) of fasting gall-bladder bile was 1.28 +/- 0.06. During bedtime administration of chenic acid the mean SI fell to 0.78 +/- 0.04, which was significantly lower than that obtained with administration in the morning (0.92 +/- 0.05) or with three divided doses at mealtimes (0.92 +/- 0.04). The bile remained supersaturated in seven patients when they received a single morning dose, in five patients when they received mealtime doses, but in only one patient when a single bedtime dose was given. There was no significant difference in side effects between the three different dose timings, or in the proportion of bile acids present in the bile as chenic acid. This enhanced effect obtained with bedtime administration may be due to the enterohepatic circulation of bile acids being maintained during overnight fasting.

Adult↗
PubMed1979

Cimetidine: effect on pancreatic and biliary function in man.

1 Pancreatic and biliary function were studied in eight patients taking oral cimetidine (1.6 g/day for 6 weeks) for endoscopically confirmed active peptic ulcer disease. 2 Postprandial jejunal tryptic activity and bile acid concentration were unchanged during cimetidine given for 1 and 6 weeks. 3 Postprandial gallbladder emptying was also unchanged. 4 Direct examination of postprandial upper jejunal aspirate for deconjugated bile acids was negative in all patients; but the more sensitive [14C]-glycocholate bile acid breath test showed a significant increase in breath 14CO2, indicating increased bacterial deconjugation of bile acids in the gastrointestinal tract.

Adult↗
PubMed1978

Effect of cimetidine in symptomatic gastro-oesophageal reflux.

Twenty-seven patients with symptomatic gastro-oesophageal reflux received cimetidine 1.6 g daily for 6 weeks and matching placebo for 6 weeks in a randomised double-blind crossover trial. They complained of significantly more episodes of pain on placebo than on cimetidine (1186 vs 581) and consumed significantly more antacid tablets on placebo than on cimetidine (1645 vs. 1011). Cimetidine and placebo had similar effects on mucosal sensitivity to acid and on oesophagitis assessed endoscopically and histologically, suggesting that the symptomatic benefit is the result of a simple antacid effect.

Adult↗
PubMed1978

Low-cholesterol diet: enhancement of effect of CDCA in patients with gall stones.

Fifteen patients with gall stones who were taking chenodeoxycholic acid(CDCA) 15 mg/kg at bedtime participated in two separate experiments to investigate the effects of altering sterol intake on the cholesterol saturation index (SI) of fasting gall-bladder bile. In experiment I the 15 patients on an unrestricted diet had a SI of 0.87 +/- 0.04 (mean +/- SE of mean), which fell to 0.75 +/- 0.04 after one week in hospital on a diet of 100 mg cholesterol daily. In experiment II seven of the patients were given four different dietary regimens lasting one month each in random order as outpatients. On a diet of 600 mg of cholesterol daily the mean SI was 0.72 +/- 0.05, which fell to 0.67 +/- 0.05 when the patients were put on a 100 mg cholesterol diet. The addition of plant sterols (3 g daily) to both diets raised the mean SIs to 0.80 +/- 0.05 and 0.77 +/- 0.05 respectively. The percentage CDCA in bile was unaffected by alterations in the cholesterol and plant sterol intakes. We conclude that a low-cholesterol diet but not a high intake of plant sterols enhances the effect of CDCA in patients with gall stones.

Adult↗