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Biomedical subjects

J J Gonvers

Publications and source records attributed to J J Gonvers.

At least 19 recordsLinked to original sources
PubMed1995

Role of nutrient fat and cholecystokinin in regulation of gallbladder emptying in man.

Postprandial gallbladder contraction is mainly regulated by cholecystokinin (CCK), but little is known about the dose-response relationship between CCK release and gallbladder contraction, in particular after meals with differing fat content. Decreased postprandial gallbladder emptying has been suggested to play a major role in the development of gallstones in man, and dietary factors may therefore be important in the pathogenesis of gallbladder stasis. We studied, in a randomized order, the effect of three isocaloric meals (250 ml) with identical osmolality on CCK release and gallbladder contraction in six healthy volunteers: (1) a pure fat meal (25 g triglycerides); (2) a mixed meal containing fat (8 g, 29% of caloric content), protein (10 g, 17%), and dextrose (32 g, 54%); and (3) a fat-free meal containing albumin (25 g, 46%) and dextrose (32 g, 54%). Gallbladder volumes and antral cross-sectional areas were determined by ultrasonography and plasma CCK and PP levels by RIA. The pure fat meal caused the highest CCK release (187 +/- 27; mean +/- SEM) and maximal (> 85% of fasting volume) gallbladder contraction (3172 +/- 361; AUC) as compared to the other two meals (P < 0.05). The mixed and the fat-free meal caused similarly low (< 50% of fasting volume) gallbladder contraction (6052 +/- 342 and 6134 +/- 500, respectively), although they induced markedly different CCK levels (157 +/- 12 and 87 +/- 13, respectively; P < 0.05). Gastric emptying rates were similar for all meals (18,500 +/- 3300, 18,600 +/- 2700 and 19,800 +/- 3100, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

Conscious sedation for gastroscopy: patient tolerance and cardiorespiratory parameters.

BACKGROUND/AIMS: Most patients receive conscious sedation for gastroscopy. However, the benefit of the most often used combination of low-dose intravenous midazolam and topical lidocaine on patient tolerance remains poorly defined and has not been shown to outweigh cardiorespiratory risks. To respond to these issues, a randomized, double-blind, placebo-controlled prospective study was performed. METHODS: Two hundred outpatients undergoing diagnostic gastroscopy were assigned to receive either (1) midazolam (35 micrograms/kg) and lidocaine spray (100 mg), (2) midazolam and placebo lidocaine, (3) placebo midazolam and lidocaine, or (4) placebo midazolam and placebo lidocaine. RESULTS: Tolerance (visual analogue scale, 0-100 points; 0, excellent; 100, unbearable) improved as compared with placebo midazolam and placebo lidocaine by 23 points (95% confidence interval, 15-32) in group 1, 15 points (95% confidence interval, 7-24) in group 2, and 10 points (95% confidence interval, 2-18) in group 3. Increasing age (P < 0.001), low anxiety (P < 0.001), and male sex (P < 0.03), but not amnesia, were associated with better patient tolerance. Oxygen desaturation (< 1 minute) occurred in 8.2% and was not more frequent after midazolam treatment. Hypotension was rare (2.1%), and no adverse outcome occurred. CONCLUSIONS: Both low-dose midazolam (35 micrograms/kg) and lidocaine spray have an additive beneficial effect on patients tolerance and rarely induce significant alterations in cardiorespiratory monitoring parameters, thus supporting the widespread use of conscious sedation.

Adult↗
PubMed1995

Effect of cisapride on gallbladder motility after extracorporeal shock-wave lithotripsy.

BACKGROUND/AIMS: Altered gallbladder motility is regarded as one of the important factors involved in the formation and recurrence of gallstones. Previous studies have suggested that cisapride increases postprandial gallbladder contraction and may therefore be theoretically useful in preventing stone recurrence. The aim of our study was therefore to investigate the effect of cisapride on gallbladder motility in stone-free patients after extracorporeal shock-wave lithotripsy, as compared to healthy volunteers pair-matched for age and sex. METHODS: Each subject received cisapride or placebo in a double-blind, cross-over, random order. Gallbladder volumes were measured by ultrasonography in the fasting state and after intake of a standard liquid meal. Plasma cholecystokinin levels were determined by radioimmunoassay. RESULTS: Fasting gallbladder volumes were smaller in patients as compared to volunteers (20.7 +/- 1.3 ml vs. 46.0 +/- 9.2 ml; p < 0.05) but were not modified by cisapride (21.1 +/- 1.7 ml vs. 58.6 +/- 11.3 ml). The maximal postprandial decrease in gallbladder volume was similar in patients and volunteers (64.5 +/- 12% vs. 62 +/- 10%; NS) and was not significantly altered by cisapride (59 +/- 9.4% vs. 54 +/- 9%; NS). In patients, cisapride increased integrated postprandial gallbladder volume by accelerating gallbladder refilling as compared to placebo by 37 +/- 15% (p < 0.05). Integrated cholecystokinin plasma levels were similar in patients and volunteers and were 13.4 +/- 4.7% higher after cisapride as compared to placebo (p < 0.05). CONCLUSIONS: The results of this study suggest that cisapride does not alter postprandial gallbladder contraction but accelerates gallbladder refilling in patients free from gallstones after extracorporeal shock-wave lithotripsy. This effect of cisapride is probably due to an acceleration of gastric emptying also causing a secondary enhanced cholecystokinin release.

Adult↗
PubMed1994

[Evaluation of deviating liver tests in ambulatory practice].

The finding of disturbed hepatic function, associated with an unclear clinical picture or during of a health checkup, is frequent. A physician's approach to a patient presenting disturbed hepatic function tests does not depend on well-defined algorithms but requires a sound knowledge of hepatic function tests and indicators of hepatobiliary disease. There are two major categories of hepatic function tests: non-specific tests which may indicate the existence of hepatic disease, and specific tests which permit assessment of the nature of hepatic damage. To facilitate the search for an etiology, it is helpful to classify hepatobiliary diseases according to the type of disturbance of hepatic function. One may speak of hepatocellular necrosis if elevation of the transaminases is the sole or predominant feature, and of cholestasis if the elevation solely or essentially involves the alkaline phosphatases and gamma-GT. Chronic hepatitis C, alcoholism and obesity frequently underline an isolated elevation of the transaminases.

Biliary Tract Diseases↗
PubMed1994

Association of Crohn's disease and Cogan's syndrome.

We describe the case of a young woman with Cogan's syndrome and associated Crohn's disease. Systemic disease was manifested by oligoarthritis and valvular involvement. Crohn's disease has previously been described in two cases of Cogan's syndrome. We suggest therefore that Crohn's disease is pathogenetically related to Cogan's syndrome. For both, systemic involvement is characteristic, and immune-mediated mechanisms and vasculitis are thought to play a major pathogenetic role. Furthermore, both respond to treatment with corticosteroids.

Adult↗
PubMed1994

Conscious sedation, clinically relevant complications and monitoring of endoscopy: results of a nationwide survey in Switzerland.

There is no conclusive evidence that electronic monitoring during gastrointestinal endoscopy reduces patient morbidity and mortality. The aim of this nationwide Swiss survey was to assess the impact of monitoring on the outcome for patients. We therefore evaluated the monitoring practice and the rate of sedation-related clinically relevant complications in a country with a low monitoring prevalence, and compared the results with those for a country in which monitoring is widely applied. A questionnaire pertaining to 1990 was mailed to all 173 Swiss gastroenterologists. The response rate was 71.1%. Data from 115,200 endoscopies performed by 123 gastroenterologists were analysed. Sixty percent of the procedures were performed under sedation. Patient's vital signs were rarely monitored clinically (< or = 25%). Electronic monitoring was virtually never performed: oximetry was used by 2.5% and an electrocardiogram by 0.8%. The overall sedation-related complication rate was 0.10%, and no deaths occurred. Thus, the morbidity and mortality related to conscious sedation in Switzerland is low, and not higher than it is in countries with a high monitoring level, such as the USA (0.06-0.54%). We conclude that clinically detectable and relevant complications attributable to conscious sedation are rare even when vital parameters are not monitored routinely. There is need for a prospective study to evaluate the effect of electronic monitoring on the complication rate for average-risk patients undergoing routine gastrointestinal endoscopy.

Colonoscopy↗
PubMed1994

Evaluation of third-generation assays for detection of anti-hepatitis C virus (HCV) antibodies and comparison with presence of HCV RNA in blood donors reactive to c100-3 antigen.

We tested serum samples from blood donors by using first-, second-, and third-generation enzyme immunoassays or recombinant immunoblot assays. Second- and third-generation assays gave comparable results. Circulating hepatitis C virus RNA was found in a high proportion of reactive samples. A lack of reactivity or low-level reactivity predicted the absence of hepatitis C virus RNA in 100% of the cases.

Antigens, Viral↗
PubMed1994

Duodenal bacterial overgrowth during treatment in outpatients with omeprazole.

The extent of duodenal bacterial overgrowth during the pronounced inhibition of acid secretion that occurs with omeprazole treatment is unknown. The bacterial content of duodenal juice of patients treated with omeprazole was therefore examined in a controlled prospective study. Duodenal juice was obtained under sterile conditions during diagnostic upper endoscopy. Aspirates were plated quantitatively for anaerobic and aerobic organisms. Twenty five outpatients with peptic ulcer disease were investigated after a 5.7 (0.5) weeks (mean (SEM)) treatment course with 20 mg (nine patients) or 40 mg (16 patients). The control group consisted of 15 outpatients referred for diagnostic endoscopy without prior antisecretory treatment. No patient in the control group had duodenal bacterial overgrowth. In the omeprazole group bacterial overgrowth (> or = 10(5) cfu/ml) was found in 14 (56%) patients (p = 0.0003). The number of bacteria (log10) in duodenal juice in patients treated with omeprazole was distinctly higher (median 5.7; range < 2-8.7) when compared with the control group (median < 2; range < 2-5.0; p = 0.0004). As well as orally derived bacteria, faecal type bacteria were found in seven of 14 and anaerobic bacteria in three of 14 patients. Bacterial overgrowth was similar with the two doses of omeprazole. These results indicate that duodenal bacterial overgrowth of both oral and faecal type bacteria occurs often in ambulatory patients treated with omeprazole. Further studies are needed to determine the clinical significance of these findings, particularly in high risk groups during long term treatment with omeprazole.

Adult↗
PubMed1994

Gastric and duodenal bacterial colonization in HIV-infected patients without gastrointestinal symptoms.

OBJECTIVE: To assess the prevalence of gastric and duodenal bacterial colonization in HIV-infected patients. METHODS: Twenty-three consecutive outpatients at various stages of HIV infection were examined. No patient received antibiotic therapy or antisecretory drugs, and none presented with digestive symptoms. A second group consisted of 39 patients without risk factors for HIV infection referred to the gastroenterology outpatient clinic for suspected peptic ulcer disease. Gastric and duodenal juices were aspirated separately through the endoscope under direct visual control, using a sterilized double-sheathed tube. Specimens were plated quantitatively for both aerobic and anaerobic organisms. Parasitological evaluation was done on duodenal samples. RESULTS: gastric and/or duodenal bacterial colonization was documented in 7/23 (30%) HIV+patients and in 3/39 (8%) patients in the second group (p < 0.05). No parasites were detected. All isolates were oral Gram-positive cocci or bacilli. Mean fasting gastric pH was significantly higher in HIV-infected patients with bacterial colonization than in HIV-infected patients and patients in the second group without bacterial colonization (p < 0.02). There was no correlation between the presence of bacterial colonization and CD4+ cells counts. CONCLUSION: HIV infection may predispose to asymptomatic digestive bacterial colonization. Further studies are needed to assess the role of bacterial colonization in symptomatic patients presenting with diarrhea and/or weight loss.

Adult↗
PubMed1993

[Extracorporeal shockwave lithotripsy of the gallbladder: importance of selection criteria].

In recent years, a number of alternatives to surgery for gallstones have been developed. Among them, extracorporeal shock-wave lithotripsy (ESWL) was promising, being non-invasive and risk-free. Nevertheless, its results vary according to the size, number and composition of the stones and according to the bile acids treatment used for fragment dissolution. To better evaluate the importance of these factors, we have widened the selection criteria currently used (1 to 3 non-calcified stones with a diameter below 30 mm) by including patients with large stones (up to 40 mm in diameter), multiple stones (up to 10 stones) and calcified stones. We also compared, for efficacy of fragment dissolution after ESWL, treatment by ursodeoxycholic acid alone as opposed to a mixture with chenodeoxycholic acid. Our results were (1) significant lessening of the fragmentation rate and of the number of gallbladders free of stones 1 year after ESWL when selection criteria are widened; (2) a mixture of ursodeoxycholic and chenodeoxycholic acids may favour fragment dissolution after ESWL compared to treatment by ursodeoxycholic acid alone.

Adolescent↗
PubMed1993

Low-dose interferon in chronic hepatitis non-A/non-B: effects on quantitative liver function and structure in a randomized, controlled multicenter trial.

In this randomized, controlled multicenter trial we evaluated the effects of recombinant interferon-alpha 2b on galactose elimination capacity and histological activity index in 88 patients with chronic active hepatitis non-A/non-B. Forty-five patients were randomly assigned to treatment with interferon at 1.5 x 10(6) U three times per for 1 year; 43 patients were assigned to no treatment. A complete response (normalization of alanine aminotransferase) was observed, respectively, in 47% and 5% of the two groups (P < 0.006); 47% of these patients suffered a relapse. Thus 22% of patients had a sustained response. Histological activity decreased significantly in responders (P < 0.04) while the biopsy score did not change significantly in nonresponders. In contrast, galactose elimination capacity--a surrogate marker for survival in chronic active hepatitis--was not affected by response to treatment. None of the parameters evaluated, including hepatitis C virus RNA, was able to predict response or relapse. We conclude that low-dose interferon treatment for 1 year is as effective as the recommended treatment schedule.

Adolescent↗
PubMed1993

Practice and complications of liver biopsy. Results of a nationwide survey in Switzerland.

Studies on the complication rate of liver biopsy have hitherto been conducted in referral hospital centers. They are therefore not representative for general practice where liver biopsy is performed by specialists and nonspecialists. In a postal nationwide survey, we approached all gastroenterologists and hospital internists to assess the complication rate and practice (setting, needle type, use of ultrasonography) of percutaneous liver biopsy performed in 1989 in Switzerland for diffuse liver disease. Two hundred eighty questionnaires were mailed and 252 were returned (response rate 90.0%) 165 respondents (65.5%) performed 3501 biopsies while 87 respondents (34.5%) did not practice liver biopsy; 67.7% of biopsies were executed blindly and 32.3% were guided. Eight nonfatal and three fatal complications occurred. Hemorrhage was the most frequent complication (five cases) and was responsible for all three fatal outcomes. The overall complication rate was 0.31%, being distinctly lower in the group of gastroenterologists (0.11%) as compared to the group of internists (0.55%; P = 0.031). The complication rate was 1.68% in the group of internists performing fewer than 12 biopsies per year, while there was no complication in the group of internists performing more than 50 biopsies per year (P = 0.036). Complications were not related to the needle diameter or to the absence of ultrasonography before biopsy. In conclusion, this representative survey in Switzerland shows that the complication rate of liver biopsy is mainly related to the experience and training of the operator.

Biopsy, Needle↗
PubMed1992

[Prevalence of anti-HCV (C100-3) antibodies in 20.373 blood donors].

The anti-HCV antibody (C100-3) is present in the serum of 70-90% of patients that are carriers of posttransfusion non-A non-B hepatitis. This marker appears to be associated with a viral replication and infectiousness state. Since 1st August 1990 the Swiss Red Cross Transfusion Service has operated a systematic search for anti-HCV antibodies for every blood donation. The aim of the study was to establish the prevalence of anti-HCV antibodies in a donor population, look for the risk factors in the anti-HCV positive group, look for biological symptoms and signs of chronic hepatitis, and compare the data with that from an anti-HCV negative control group. From August to March 1991, 20,373 donors were tested by EIA (Ortho). The presence of anti-HCV antibody was confirmed by a neutralization test (Abbott). The donors in which both tests were positive formed the group studied (55 subjects). Their data was compared with that of a control group of anti-HCV negative donors. The prevalence of anti-HCV antibody in the group of 20,373 donors was 0.29%. Possible parenteral exposure to hepatitis C virus was found in 47% of anti-HCV positive subjects (30% blood transfusion, 9% i.v. drug addiction, 8% tattooing). 42% of the anti-HCV positive donors had no risk factor presently known for hepatitis C. 27% of anti-HCV positive donors had elevated transaminase levels. Until more effective screening tests are introduced it appears necessary to stress the previous history of future blood donors in order to search for hepatitis C risk factors.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Donors↗