摘要:

SUMMARYMost major pathways of hepatic drug metabolism are dependent on oxygen. Hepatic mixed‐function oxidases use oxygen directly as a substrate, while many other enzyme systems are indirectly dependent on oxygen for the generation of essential co‐factors, such as NAD‐and ATP. Studiesin vitroshow that many of these oxygen‐dependent reactions are impaired by relatively minor reductions in oxygen supply, of a magnitude likely to be encounteredin vivo.Phase I metabolism by mixed‐function oxidases appears to be more sensitive to hypoxia than phase II drug conjugation, although the oxygen requirements of conjugation reactions, such as glucuronidation, may be greatly enhanced by poor nutrition or fasting. Studies in humans are few, but in general they affirm the potential importance of the effects of hypoxaemic states on hepatic drug elimination. On present evidence, special care should be taken in hypoxic patients with drugs extensively metabolized by the liver, particularly those which have a low therapeu

ISSN:0269-2813    

DOI:10.1111/j.1365-2036.1990.tb00466.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

SUMMARYMetronidazole is a nitro‐imidazole drug which was discovered nearly 30 years ago. Metronidazole has remained the mainstay of anti‐anaerobic therapy following a chance observation that its activity included anaerobic organisms. The predominant human reservoir of these anaerobic organisms is the gastrointestinal tract. In this review, the anaerobic flora and their pathogenic potential are described. The main characteristics of metronidazole and the role of selective decontamination of the gastrointestinal tract are also discus

ISSN:0269-2813    

DOI:10.1111/j.1365-2036.1990.tb00467.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

SUMMARYThe effects of the H+, K+‐ATPase inhibitor BY 1023/SK&F 96022 on pentagastrin‐stimulated acid secretion have been studied in healthy male volunteers (n= 12). The gastric acid response to submaximal pentagastrin‐stimulation (0.6 μg/h/kg b.w.) was dose‐dependently inhibited. A single dose of 5 mg decreased acid output by 22% while after 60 mg and 80 mg secretion was almost completely abolished.A good dose linearity was observed for AUC (0,>) andCmaxover the dose range from 5 to 80 mg. Elimination half‐life, total clearance and volume of distribution of the parent compound were independent of the dose.The drug was well tolerated up to the highest dose of 80 mg. No clinically relevant influence was found on either laboratory screen or cardiovascular

ISSN:0269-2813    

DOI:10.1111/j.1365-2036.1990.tb00468.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

SUMMARYGastrointestinal pH in 11 healthy subjects with ileostomy was determined with a pH‐sensitive, radiotransmitting capsule. Median pH was 7.0 in duodenum, dropped to pH 6.3 in the proximal part, but rose to 7.3 in the distal part of the small intestine. In five subjects the pH of the ileostomy effluents was determined with the pH capsule as well as with a pH meter. Median pH was 7.2 measured with the capsule and 7.4 with the pH meter. The difference between the results obtained with the two methods ranged from 0.1 to 0.3 pH units. The median gastrointestinal transit time of the capsule was 10.5 h (range 6.2–12.8 h). Gastric residence time was 0.6 h (range 0.2–3.8 h), and small intestinal transit time was 10.3 h (range 5.6–11.9 h). Thus the small intestinal transit time in ileostomates is slightly increased compared with values reported from studies on subjects with intact gut. However, no statistically significant correlation was found between the small intestinal transit time and the time elapsed after the creation of the ileostomy. We conclude that colectomy does not alter small intestinal pH but seems to increase the small intestinal transit time of singl

ISSN:0269-2813    

DOI:10.1111/j.1365-2036.1990.tb00469.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

SUMMARYExperimental colitis was induced in rabbits by exposing the colon mucosa to 1% formalin followed by i.v. injections of soluble immune complexes made with antigen in excess. The animals were preimmunized withEsherichia coli014:K7:H — inducing antibodies cross‐reactive to intestinal epithelium.Animals with this colitis were divided in two groups. One group was treated with sulphasalazine and the other was given vehicle only. Sulphasalazine was administered daily at 125.5 μmol (50 mg) per kg body weight. The administration was started at the same day as the colitis was initiated. At Day 6, 13 and 30 following induction of colitis, biopsies were sampled and histologically evaluated. Inflammation was assessed by scores for inflammatory cells, crypt distortion, decreased crypt number and presence of crypt abscesses, thus corresponding to the picture seen in humans. A statistically significant lower score of inflammation was seen on Day 6 and 13 (P<0.01) and on Day 30 (P<0.05) following induction of colitis in animals treated with sulphasala

ISSN:0269-2813    

DOI:10.1111/j.1365-2036.1990.tb00470.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

SUMMARYHistopathological methods and radioimmunoassay were used to assess the microstructure and prostaglandin E2production by paired specimens of human gastric antral mucosa; the specimens were studied after 48 h of incubation in base‐line tissue culture medium,Helicobacter pyloriculture filtrate,H. pyloriculture control fluid, indomethacin, andH. pyloriculture filtrate plus indomethacin. When applied alone, the filtrate did not affect the structure of the mucosal tissue or its prostaglandin E2synthesis. In the overall group (n = 21), specimens incubated with the mixture ofH. pylorifiltrate and indomethacin had a median histological grade of 1 and prostaglandin E2of 29 pg/mg tissue, compared to 2 pg/mg (P= 0.04) and 60 pg/mg (P= 0.0007) respectively, in specimens incubated with indomethacin alone.These results indicate that an interaction may exist betwe

ISSN:0269-2813    

DOI:10.1111/j.1365-2036.1990.tb00471.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

SUMMARYIn a double‐blind randomized study, the profile of 24‐h intragastric acidity and nocturnal gastric secretion was measured in a group of patients with healed gastric ulcer on placebo and 400 mg cimetidine b.d. and 800 mg nocte. Neither cimetidine regimen significantly decreased daytime intragastric acidity, but the 800 mg nocte dose caused a significant decrease in both nocturnal acidity (18.1 to 5.5 mmol/L;P<0.05) and acid output (11.0 to 1.7 mmol 7 h;P<0.05). The decrease in nocturnal gastric secretion by 400 mg cimetidine b.d. was not significant.As in duodenal ulcer, 800 mg cimetidine nocte will effectively suppress night‐time acid secretion in patients with gastric ulcer while leaving acid secretion during the day unaff

ISSN:0269-2813    

DOI:10.1111/j.1365-2036.1990.tb00472.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

SUMMARYA theoretical basis for similar recurrence rates among H2‐receptor antagonists exists based on recent concepts of ulcer recurrence, ulcer healing and suppression of nocturnal gastric acidity. In order to compare H2‐receptor antagonists in the maintenance therapy of duodenal ulcer, a meta‐analysis was carried out using 29 studies in the literature that met strict criteria. When the results of the placebo‐controlled studies were expressed as odds ratios, a technique used to minimize differences in protocol design and patient populations among studies, cimetidine, ranitidine, famotidine and nizatidine were all found to be superior to placebo to approximately the same extent. Odds ratios (and 95% confidence limits) for the recurrences in the pooled studies were cimetidine 0.22 (0.18–0.28), ranitidine 0.23 (0.18–0.30), famotidine 0.28–0.31 and nizatidine 0.36. These reflected similar 1‐year recurrence rates of 24.9% (n= 530) for 400 mg cimetidine nocte, 22.4 (n= 508) for 150 mg ranitidine nocte, 28.0% (n= 371) for 20 mg or 40 mg famotidine nocte, and 21.8% (n= 261) for 150 mg nizatidine nocte. In studies to compare cimetidine and ranitidine directly, the odds ratio (and 95% confidence limits) was 0.64 (0.48–0.86). However, for two studies done by a single protocol, the odds ratio of 0.51 (0.35–0.75) tended todiffer from the odds ratio of 0.85 (0.54‐1.33) for six other studies (P = 0.09). These reflected recurrence rates for cimetidine and ranitidine of 28.3% and 16.8% (two studies) and 23.3% and 20.6% (six

ISSN:0269-2813    

DOI:10.1111/j.1365-2036.1990.tb00473.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

SUMMARYEighteen healthy volunteers were included in a cross‐over, double‐blind study where 500 mg naproxen b.d. was given for 1 week with 20 mg famotidine b.d., 40 mg nocte or placebo. Endoscopic evaluation of the gastroduodenal mucosa was performed before and after each treatment period, with separate evaluation of the mid‐ and distal duodenum.51Cr‐EDTA‐permeability tests were done to study effects on the mid‐ and distal gut, and, in addition, symptom registration was performed. The mucosal damage was significant in all treatment periods, and a statistically significant reduction was seen with 20 mg famotidine b.d. for erosive lesions in the stomach/duodenal bulb region as well as for the sum of damage score in the mid‐ and distal duodenum. The reduction was considerable in a few subjects with extensive duodenal damage. The reduction was considerable in a few subjects with extensive duodenal damage. Intestinal permeation increased significantly in all periods, and was not reduced by famotidine. Symptoms were modest and equal i

ISSN:0269-2813    

DOI:10.1111/j.1365-2036.1990.tb00474.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

SUMMARYIntravenous nicardipine has previously been shown to abolish the effect of a 1000‐calorie meal on colonic motility. The purpose of this study was to use the same experimental design to assess the effect of nicardipine instilled directly into the colon. Each patient was studied three times when receiving either placebo, 15 mg or 30 mg nicardipine infused over 2 h. Blood concentrations of nicardipine remained very low, but neither dose of the drug affected either basal or post‐prandial colonic motility. Topical nicardipine does not appear to have therapeutic potential and its activity is probably dependent on systemic absorpt

ISSN:0269-2813    

DOI:10.1111/j.1365-2036.1990.tb00475.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY