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Biomedical subjects

J F Nyst

Publications and source records attributed to J F Nyst.

18 recordsLinked to original sources

Gastric screening prospects.

The incidence of gastric cancer is rapidly declining in the Western world, but it remains high in the Third World and in Japan. Systematic screening for gastric cancer has been undertaken in Japan, where barium X-ray is used in people over the age of 40. Evaluation data suggest a benefit in reduced mortality, but biases cannot be ruled out. A similar screening programme has been started in Venezuela. Currently, stomach cancer screening programmes cannot be recommended as public health policy, except in high-risk areas where they have already started. The Correa model of gastric carcinogenesis states that environmental influences cause a normal gastric mucosa to undergo successive stepwise changes, through superficial gastritis, atrophic gastritis, intestinal metaplasia, dysplasia, carcinoma and, finally, invasion. Incriminated environmental influences include irritant, antibodies, gastrectomy, nutritional deficits, intake of nitrogen compounds and Helicobacter pylori. These bacteria cause a chronic superficial gastritis, which may develop into atrophic gastritis. H. pylori is less frequently found in advancing preneoplastic lesions, and seldomly in gastric carcinoma tissue (it may, however, be identified more readily in the surrounding non-cancerous tissue). Several lines of evidence suggest that H. pylori may play an important role in human gastric carcinogenesis. We found that in some patients with H. pylori infection and without preneoplastic lesions, the gastric cell turnover was increased; this was correlated with the intensity of the inflammatory changes.(ABSTRACT TRUNCATED AT 250 WORDS)

Helicobacter Infections↗

A randomized, multi-observer, comparative evaluation of conventional fiberendoscopy and videoendoscopy in the upper GI tract.

In a comparative, histologically controlled study, no significant difference was found in the accuracy of conventional fiberendoscopy and videoendoscopy in the diagnosis of upper gastrointestinal tract lesions. Both techniques permitted accurate description of focal and/or ulcerative lesions, but videoendoscopy did not provide better sensitivity than fiberendoscopy in the diagnosis of superficial, non-ulcerative, inflammatory changes. The same results were obtained on checking the reproducibility of the macroscopic diagnosis by a delayed review of recorded videotapes.

Duodenal Diseases↗

The reliability of urease tests, histology and culture in the diagnosis of Campylobacter pylori infection.

The accuracy of various staining techniques for immersion microscopy, of five media for culture and five urease test modalities for the detection of Campylobacter pylori infection is reported. It was found that 2% urea unbuffered gel preparation is the most accurate urease test (sensitivity: 89%, specificity: 98%) but a minimal amount of 10,000 CFU/ml is necessary to observe positivity and the sensitivity of urease tests drops to 52% in patients under antimicrobial treatment. For histological diagnosis, modified Giemsa staining was shown to be slightly superior to H&E. The most valuable diagnosis technique is culture when the biopsy specimen is transported and processed under appropriate conditions. A 94% sensitivity rate was observed with 'BCC agar', a new medium containing brain heart infusion, activated charcoal and horse serum.

Bacteriological Techniques↗

[Clinical, endoscopic and histologic findings in 1,100 patients of whom 574 were colonized by Campylobacter pylori].

Of 1,100 patients checked by at least two diagnostic tests (urease, histology, culture) 574 (52.1 p. 100) were found to have Campylobacter pylori (C. pylori) in their antral mucosa. Significantly different frequencies of C. pylori (p less than 0.005) were evidenced in the group of patients with active gastroduodenal ulcer (212/298, 71 p. 100), in non-ulcer dyspepsia (NUD) with a previous history of GD ulcer (108/177, 61 p. 100) and NUD without antecedent history of GD ulcer (254/625, 41 p. 100). Whatever the group, males and immigrants were significantly at risk. Chronic alcoholism (greater than 60 g/day) and non-steroid anti-inflammatory drug (NSAID) intake were not predictive for the presence of C. pylori but smokers were significantly at risk when the total (n = 1,100) population was taken into consideration. C. pylori was found in 29 p. 100 of asymptomatic controls (n = 31). There was no significant difference in the frequency and intensity of symptoms when comparing C. pylori+ and C. pylori- patients. The macroscopic aspect of the antral mucosa was not predictive since 51 p. 100 of patients with normal endoscopy were C. pylori+. A strong correlation was observed between the incidence of C. pylori and the severity of gastritis at histology (p less than 0.001) and C. pylori was found in 7 p. 100 of patients with normal histology.(ABSTRACT TRUNCATED AT 250 WORDS)

Alcoholism↗

Juxtapapillary duodenal diverticula and diverticula of the colon: is there a general "gastrointestinal diverticular disease"?

Both juxtapapillary duodenal diverticula and colon diverticula are acquired lesions, the pathogenesis of which is believed to involve the influence of high intraluminal pressure on loci minoris resistentiae in the gastrointestinal wall. We wanted to investigate whether juxtapapillary duodenal diverticula and colon diverticula occur independently, or whether they are part of a hypothetical general "gastrointestinal diverticular disease". 239 patients with juxtapapillary duodenal diverticula were identified in 2231 patients undergoing ERCP. Complete radiology data were available in 119/239 patients. Double contrast barium enema had been performed in 28/119 patients. In these patients, colon diverticula were present in 9/20 women and 1/8 men. The frequency of colon diverticula in these patients was compared with randomly chosen age- and sex-matched controls, for whom barium enema results were available. In these controls, 9/20 women and 1/8 men also had colon diverticula (n.s.). We conclude that after stratification for age and sex, the occurrence of colon diverticula is not higher in patients with juxtapapillary duodenal diverticula than in the general population. Juxtapapillary duodenal diverticula and colon diverticula thus occur independently. These data are not in favor of the existence of a general gastrointestinal diverticular disease.

Barium Sulfate↗

Campylobacter pylori-associated gastritis: attempts to eradicate the bacteria by various antibiotics and anti-ulcer regimens.

The efficacy of various antimicrobial and anti-ulcer agents on the eradication of Campylobacter pylori in patients with antral gastritis or duodenal ulcers was investigated by several open studies or double-blind, placebo-controlled protocols. Among the anti-ulcer agents, ranitidine, cimetidine or sucraflate had no effect on C. pylori. Colloidal bismuth subcitrate achieved clearance of C. pylori in 40% of treated patients at the end of therapy but a high relapse rate (14/16 patients) was observed after a 6-month follow-up period. The antibacterial agents doxycycline, minocycline, ofloxacin, clindamycin, paromomycin and nifuroxazide failed to eradicate C. pylori in most patients. By contrast, short term elimination of C. pylori could be achieved in more than 90% of patients treated with amoxycillin. However, relapse occurred as a rule in all amoxycillin-treated patients within one month after therapy. Overall, we observed no correlation between the in-vitro activity of the different antibacterial agents and their in vivo efficacy. Development of resistance during therapy does not seem to account for this discrepancy since it occurred only with ofloxacin. On the basis of these results, we conclude that long term eradication of C. pylori from the gastric antrum cannot be achieved after monotherapy either with antibiotics or with bismuth salts.

Anti-Bacterial Agents↗

HP serology as a screening method prior to upper gastro-intestinal endoscopy in young dyspeptic patients: a different point of view.

We performed a literature search as well as a review of our own results to evaluate HP serology as a screening method in young dyspeptic patients, prior to endoscopy. This strategy has been proposed by various teams in order to decrease the endoscopy workload. We analysed the results that could be obtained when not performing endoscopy in seronegative patients, in terms of avoided endoscopies and missed lesions. We found that too many lesions would remain undiagnosed, and thus untreated, regarding our reimbursement system, if the strategy was used without a strict selection of patients. The screening might be advisable among highly selected patients, but the percentage of avoided endoscopies would then decrease regarding the total number of endoscopies performed. Our conclusion is that HP serology as a screening method in young dyspeptic patients cannot be advised in Belgium for the time being.

Adolescent↗