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Biomedical subjects

A Burette

Publications and source records attributed to A Burette.

At least 19 recordsLinked to original sources
PubMed1995

Serologic detection of infection with cagA+ Helicobacter pylori strains.

Approximately 60% of Helicobacter pylori isolates possess the cagA gene and express its 120- to 140-kDa product (CagA). In this study, the cagA gene was detected in H. pylori isolates from 26 (81.3%) of 32 patients with duodenal ulcers (DU), 17 (68.0%) of 25 patients with gastric ulcers, and 23 (59.0%) of 39 patients with nonulcer dyspepsia (NUD). By Western blotting (immunoblotting) with antiserum to CagA, in vitro CagA expression was demonstrated for 95.5% of cagA+ strains compared with 0% of strains lacking cagA. Sera from patients infected with cagA+ strains (n = 66) reacted with recombinant CagA in an enzyme-linked immunosorbent assay to a significantly greater extent than either sera from patients infected with strains lacking cagA (n = 30) or sera from uninfected persons (n = 25) (P < 0.001). A strain lacking cagA was isolated from eight patients who had serum immunoglobulin G antibodies to CagA, which suggests that these patients were infected with multiple strains. Serum immunoglobulin G antibodies to CagA were present in 87.5, 76.0, and 56.4% of patients with DU, gastric ulcers, and NUD, respectively (odds ratio, 5.41; 95% confidence interval, 1.44 to 24.72; P = 0.004 [DU versus NUD]). These data demonstrate an association between infection with cagA+ H. pylori and the presence of duodenal ulceration and indicate that serologic testing is a sensitive method for detecting infection with cagA+ strains.

Adult↗
PubMed1993

Neutralising antibodies to the vacuolating toxin of Helicobacter pylori in gastritis only and peptic ulcer patients.

Sera from 36 patients with gastritis only and 26 patients with peptic ulcer were tested for the presence of neutralising antibodies against H. pylori vacuolating toxin. The frequency with which sera did neutralise the vacuolating toxin was not significantly different among the groups of patients with gastroduodenal ulcer infected either with toxigenic or nontoxigenic H. pylori strains (9/14 vs 4/12; ns) or in patients with gastritis only harbouring toxigenic H. pylori strains (8/12). By contrast, none of 24 sera obtained from patients with gastritis and harbouring non-toxigenic H. pylori strains did neutralise the vacuolating toxin. It is suggested that H. pylori vacuolating toxin is involved in the pathogenesis of peptic ulcer disease.

Antibodies, Bacterial↗
PubMed1992

Effect of antimicrobial therapy on the specific serological response to Helicobacter pylori infection.

The systemic immune response to Helicobacter pylori was studied in 247 infected adult patients before antimicrobial therapy and at different intervals following therapy. Endoscopy with simultaneous collection of biopsies was performed in all patients immediately before treatment, 4 to 6 weeks after the end of therapy and 6 to 12 months later. A 14C-urea breath test was performed 3 to 6 months after the end of treatment. Biopsy specimens were cultured and examined histologically using Giemsa stain. Sera were tested for Helicobacter pylori IgG antibodies with a commercial enzyme immunoassay using species-specific antigens. Overall, Helicobacter pylori was eradicated in 120 patients while the other 127 remained infected with the organism. The follow-up period ranged from 4 weeks to 33 months (mean 10.2 months). Pretreatment IgG levels did not differ significantly between the two groups of patients. Six weeks after the end of treatment a slight but definite decrease in the IgG antibody levels was seen irrespective of treatment success. In the 127 patients who remained Helicobacter pylori-positive, the level of IgG antibodies remained stable or increased with time. A continuous fall in antibody levels was observed following bacterial eradication in the other 120 patients, but the difference in antibody levels between treatment responders and nonresponders became significant only more than six months after the end of treatment (p = 0.001). Serological testing may be useful for monitoring the outcome of long-term treatment of Helicobacter pylori infection and obviate the need for endoscopy.

Adult↗
PubMed1992

Evaluation of a commercially available second-generation immunoglobulin G enzyme immunoassay for detection of Helicobacter pylori infection.

We evaluated a commercially available second-generation anti-H. pylori immunoglobulin G enzyme immunoassay (EIA) (Cobas Core Anti-Helicobacter pylori EIA; Roche S. A., Basel, Switzerland) for serodiagnosis of H. pylori infection. The results of the assay were assessed in relation to the results of bacterial culture, urease testing, and histological Giemsa stain of gastric biopsy specimens from 1,134 patients with a variety of symptoms relating to the upper gastrointestinal tract. H. pylori was detected in biopsy specimens from 660 (58.2%) patients: 6 had a normal mucosa, 123 had chronic gastritis only, and 531 were found to have chronic active gastritis by histology; endoscopy showed duodenal and gastric ulcers in 137 and 64 patients of the last two groups, respectively. The test was evaluated with different age and ethnic groups. The prevalence, sensitivity, specificity, and positive and negative predictive values were, respectively, (i) for Belgian patients between 18 and 40 years old, 34, 93, 95, 91, and 96%; (ii) for Belgian patients more than 40 years old, 53, 96, 91, 93, and 95%; and (iii) the Mediterranean patients more than 17 years old, 87, 94, 70, 95, and 64%. All sera showing discordant immunoassay results compared with the results of histology and culture of biopsy specimens, as well as those with borderline immunoassay results, were tested further by immunoblotting. Among the EIA results considered false negative, we demonstrated an absence of seroconversion in 14 of 19 patients tested by immunoblotting. Among the EIA results considered false positive, immunoblotting showed the presence of specific antibodies in 28 of 37 patients tested. Among the borderline results obtained in the first assay with 22 patients' sera, a second assay showed positive results in 10 patients (8 were positive by immunoblotting) and negative reactions in 10 patients (9 were negative by immunoblotting), whereas 2 remained borderline. These data indicate that sera showing borderline immunoassay results must be tested again. In conclusion, this commercially available second-generation EIA, which is easy and quick to perform, was found highly reliable for the serodiagnosis of H. pylori infection.

Adolescent↗
PubMed1992

Evaluation of a commercially available complement fixation test for diagnosis of Helicobacter pylori infection and for follow-up after antimicrobial therapy.

Commercially available complement fixation test reagents (Institute Virion Ltd., Rüschlikon, Zurich, Switzerland) available in package format were evaluated for the serodiagnosis of Helicobacter pylori infection. The assay was compared with bacterial culture and histological Giemsa stain of gastric biopsy specimens obtained from 930 patients of different ages and from different ethnic groups, with a variety of upper gastrointestinal tract symptoms. The prevalence, sensitivity, specificity, and positive and negative predictive values, respectively, were 35, 71, 90, 80, and 85% for Belgian patients aged 40 years or younger, 50, 81, 93, 92, and 83% for Belgian patients older than 40 years, and 83, 83, 79, 95, and 48% for Mediterranean patients. Using 645 serum specimens from 226 patients, we also evaluated the complement fixation test for its ability to monitor the eradication of H. pylori following antimicrobial therapy. Overall, H. pylori was eradicated from 122 patients while 104 patients remained infected with the organism. A significant decrease in antibody levels was observed 3 to 6 months after the end of therapy in the group of patients from whom H. pylori was eradicated.

Adolescent↗
PubMed1990

Drug therapy for Helicobacter pylori infection: problems and pitfalls.

Antibacterial chemotherapy against Helicobacter pylori is currently being assessed by open or randomized controlled clinical studies for its efficacy in eradicating this bacterium from the stomach of patients with gastritis or gastroduodenal ulcer. Whereas there is presently no "optimal" agent and treatment scheme, the combination of some antibiotics (metronidazole, tinidazole, amoxicillin) with bismuth salts proves definitely superior in vivo to either of these agents administered alone. Several reasons have been proposed, to explain the clinical failure after treatment: insufficient concentration of active drugs in gastric mucus, instability of some agents at an acidic pH, inappropriate formulation of drug, insufficient duration of treatment, and variable compliance of patients. Recently, it has appeared from several clinical trials that H. pylori may rapidly acquire resistance to some antibiotics, and that this event might also account for clinical failure. A critical review of the literature on H. pylori treatment indicates that association of bismuth and antibiotics or of antibiotics alone both may efficiently reduce the risk of emergence of resistance and improve the therapeutic outcome. Guidelines of treatment are suggested in order to avoid the future misuse of antibiotics that would increase selection of antibiotic-resistant H. pylori and negatively affect the ecology of the gastric microflora. Likewise, an accurate definition of a subset of patients with H. pylori who really will require treatment needs to be rapidly established.

Anti-Bacterial Agents↗
PubMed1990

[Retinal detachment caused by desinsertion at the ora serrata. Epidemiologic aspects and prognosis].

A study about 44 retinal detachments showed 44 cases of retinal detachment due to desinsertions at the ora serrata, including all etiologies. We found that most of the cases were young people (80% before 40 years old), and male and functional results were relatively poor (60%). In "idiopathic" cases and due to the ocular contusions, the rates of good anatomic results were respectively 86% and 95%, and visual acuity was improved in 70% and 81% of the eyes.

Adolescent↗
PubMed1989

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↗
PubMed1989

[The visual field of patients with pituitary adenoma surgically treated].

The authors report the evolution of 72 patient's visual field operated for one pituitary adenoma. They specify the constant amelioration of this investigation in chromophobic adenomas. The stability in prolactinic adenomas or somatotropic. Allowing the supervision of the visual case, at these patients, the visual field does not seem useful in the diagnosis of the tumors recurrence.

Adenoma↗
PubMed1989

[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↗