Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:6.3.4.6 (urease)
 7,490 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Enzyme-linked immunosorbent assays (ELISAs) have been developed to diagnose Helicobacter pylori infection. However, the methods are not standardized. We therefore prospectively evaluated the sensitivities and specificities of ELISAs developed in the United States and the United Kingdom in a study population comprising 41 consecutive symptomatic outpatients and 35 volunteers. At endoscopy, multiple biopsies were obtained for histology and culture and stained sections were graded for chronic gastritis, active chronic gastritis, and density of H. pylori. Serum samples were analyzed for H. pylori by ELISA. The first set of assays for immunoglobulin G (IgG) and IgA used a pool of sonicated isolates of H. pylori from five patients in the United States (antigen A). The second set of assays, developed in the United Kingdom, used three different antigens: antigen 1, an acid-extractable surface antigen; antigen 2, an acid-extractable antigen from an aflagellate variant; and antigen 3, a urease-containing fraction. Cutoff scores for positive results were determined a priori on the basis of previous serological studies. There was close agreement between histology and culture. In the study population, 36% of the individuals were H. pylori positive. The diagnostic value of the different ELISAs were highly comparable, and the crude antigens performed as well as the more purified antigens. The antigen A IgG had a sensitivity and specificity of 96 and 94%, respectively; the values for antigen 1 were 93 and 96%, respectively. The antigen A IgA and antigen 3 assays were the least sensitive tests.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Serodiagnosis of Helicobacter pylori: comparison of enzyme-linked immunosorbent assays. 176 85

Twenty-three children with Helicobacter (Campylobacter) pylori-associated chronic gastritis are reported. Family history of peptic disease, previous digestive procedures, and nonspecific epigastric pain were the most frequently encountered clinical features. Antral nodularity at endoscopy and histologic evidence of follicular gastritis were characteristic morphological aspects. Rapid urease tests suggested the diagnosis in 90% of patients. Significant increases of serum IgG and IgA against Helicobacter pylori allowed the identification of infected children with 95% cumulative sensitivity. Treatment with amoxicillin and bismuth subcitrate eradicated the infection and improved gastritis in 13 of 19 children. These findings provide further evidence for the etiologic role of Helicobacter pylori in chronic antral gastritis in children.
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PMID:Helicobacter pylori infection and chronic gastritis: clinical, serological, and histologic correlations in children treated with amoxicillin and colloidal bismuth subcitrate. 224 11

Sera from 100 children (ages, 6 to 16 years) presenting with upper gastrointestinal symptoms were examined for antibodies to Helicobacter pylori by enzyme-linked immunosorbent assay (ELISA) based on crude, loosely cell-associated antigens and a partially purified urease antigen preparation. All children underwent endoscopy, and 20 children were shown to have H. pylori infection by histology or direct culture. Serum anti-H. pylori immunoglobulin G (IgG) levels (crude antigen) were clearly raised in the infected group, particularly after preabsorption of sera against a Campylobacter jejuni antigen preparation, while IgM and IgA ELISA determinations did not discriminate between infected and H. pylori-negative patients. Only 14 children in the infected group had raised anti-urease IgG levels. Two patients in whom the organism was not demonstrated or cultured had raised specific IgG levels against both crude and urease antigens and pathological features consistent with H. pylori disease. Immunoblotting studies did not reveal any single protein antigen or simple combination of antigens that could be considered as a candidate for a more defined serodiagnostic reagent. Anti-H. pylori antibody determinations (crude antigen) performed on posttreatment samples from children in whom the organism could no longer be demonstrated suggested that sustained IgG levels may not be a reliable index of treatment failure. An IgG ELISA based on crude, loosely cell-associated antigens of H. pylori can be used for the serodiagnosis of H. pylori infection in childhood.
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PMID:Serodiagnosis of Helicobacter pylori infection in childhood. 227 95

To evaluate the accuracy of IgG and IgA serological tests in establishing a diagnosis of Helicobacter (Campylobacter) pylori gastric infection, 60 children presenting with chronic abdominal pain were prospectively studied. Endoscopic antral biopsies were obtained and analyzed for the presence of H. pylori using three standard methods: culture and identification of bacterial isolates, microscopic examination for morphologically characteristic bacteria, and urease production by the biopsy specimen. Concomitantly obtained serum samples were analyzed for the presence of IgG and IgA antibodies against H. pylori surface antigens using enzyme-linked immunosorbent assay (ELISA). Thirty-four of 60 (56.6%) had histological evidence of chronic active gastritis, eight of whom (13.3%) also had evidence of H. pylori infection by at least one criteria. Six of the eight infected patients had H. pylori demonstrated by all three methods. Of the eight infected patients, seven had IgG antibodies against H. pylori (sensitivity of 87%) and six had IgA antibodies (sensitivity of 75%). Among the six patients who had H. pylori infection confirmed by all three methods, all had IgG antibodies (sensitivity of 100%). In the patients without evidence of H. pylori infection, the IgG ELISA had a specificity of 96% (50/52), and the IgA ELISA had a specificity of 100% (52/52). Our data suggest that serological testing for the presence of antibodies against H. pylori may be a useful diagnostic tool in screening children with chronic abdominal pain for the presence of gastric infection with H. pylori.
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PMID:Helicobacter pylori-related gastroduodenal disease in children. Diagnostic utility of enzyme-linked immunosorbent assay. 238 45

Four sequential immuno-assays were performed from May to November 1988 to follow the levels of IgG, IgA and IgM to Campylobacter pylori in 16 infected patients with histologically proven gastritis, among which 12 received appropriate therapy. Histopathological examination of antral biopsies, bacteriological cultures and urease tests were performed on each occasion when serum was tested for antibodies to C. pylori. The detection and quantitative assessment of the various isotypes to this bacterium proved valuable to appreciate the response to therapy with, in case of success, a steady decrease of antibodies levels concomitant with clinical improvement.
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PMID:Isotype evolution in the follow-up study of patients with Campylobacter pylori associated gastritis. 261 31

Fifty-two unselected patients referred to for upper gastrointestinal endoscopy were evaluated in several ways to determine the presence of Campylobacter pylori. Antibodies against this microorganism were measured to assess the value of serology for the diagnosis of C. pylori infection. Five antral biopsy specimens were taken in each patient for culture and bacteriological determinations, histology [morphology and Warthin-Starry (WS) staining] and the urease test (2, 3 and 24 h). Serum antibodies against a sonicate of 6 strains of microorganisms were assayed by enzyme-linked immunoassay (ELISA) and an immunoblotting technique. In 14 of the 52 patients the histology of the antrum was normal, 18 patients had chronic active gastritis and 20 had chronic gastritis without polymorphonuclear infiltration. In the group with normal histology, only 1 patient was positive for C. pylori with all methods, and 1 other subject was positive for IgG and 2 for IgA only with ELISA. In the group with chronic active gastritis, 14 were positive with all methods, 1 was negative by WS only and another was negative for IgA according to ELISA, WS and antibodies. Among the patients with chronic gastritis, 7 were positive and 7 negative with all tests; in the other 6 patients the results obtained with the various tests were divergent. Four serological tests were studied and validated against culture, WS and urease test which were considered to be the reference methods. The serological tests showed high sensitivity and specificity for the detection C. pylori-associated active chronic gastritis of the antrum, and can therefore serve as noninvasive methods to identify individuals with this condition.
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PMID:Value of serology (ELISA and immunoblotting) for the diagnosis of Campylobacter pylori infection. 262 36

A consecutive series of 51 children (mean age 11 years) who presented with recurrent abdominal pain were investigated by upper gastrointestinal endoscopy including three antral biopsies for microscopy, culture and urease testing. Serum IgG, IgA, and IgM antibodies to Campylobacter pylori (C pylori) were measured by the ELISA technique. Serum pepsinogen I was also measured. Thirty two children showed histological evidence of gastritis. All had C pylori on microscopy and or culture. Nineteen children showed no histological gastritis nor evidence of C pylori on microscopy, culture and/or urease testing. The IgG and IgA antibody levels to C pylori were significantly higher in C pylori positive children than in the negative group (p less than 0.001). Serum pepsinogen I concentrations were also significantly higher in C pylori positive children than in negative (p less than 0.001). Measurement of IgG antibody levels, combined with serum pepsinogen I estimation, predict the presence of C pylori associated gastritis in children with a sensitivity and specificity of up to 95%. It may be used therefore to predict gastritis and even peptic ulceration in children presenting with non-specific upper abdominal pain.
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PMID:Serum pepsinogen I and IgG antibody to Campylobacter pylori in non-specific abdominal pain in childhood. 275 88

A surface antigen (SA), acid glycine extract (AGE), and urease preparation (UP) were evaluated using sera from patients undergoing endoscopy and from subjects with gastric or duodenal ulcers. Sera were tested for the presence of IgG and IgA antibodies by a conventional indirect enzyme linked immunosorbent assay (ELISA). In patients with confirmed Campylobacter pylori associated gastritis, raised IgG antibody titres were indicated by absorbance values of greater than or equal to 500, greater than or equal to 500, and greater than or equal to 1500 for the SA, AGE, and UP, respectively. Corresponding values for the IgA assay were greater than or equal to 500, greater than or equal to 500, and greater than or equal to 1000. The specificity of the IgG assays were 94%, 92%, and 90% for the AGE, SA, and UP, respectively. In contrast, the UP was the most sensitive (97%); the other two antigen preparations gave values of 82%. In the IgA assay the UP showed the greatest specificity (90%) and sensitivity (90%). The predictive value for a true positive for the IgG assay was the same for all antigens (93%), whereas the UP gave a predictive value for a true negative of 96% compared with 79% for the other two antigen preparations. Of the patients with gastric or duodenal ulcers, raised antibody titres to SA were found in 72% (IgG) and 73% (IgA), to AGE in 75% (IgG) and 63% (IgA), and to UP in 77% (IgG) and 75% (IgA). The use of a urease antigen preparation to determine IgG antibody is recommended for screening patients undergoing endoscopy.
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PMID:Evaluation of three Campylobacter pylori antigen preparations for screening sera from patients undergoing endoscopy. 276 Feb 33

Beagle serum proteins were separated by polyacrylamide gel electrophoresis (PAGE) and the electrophoretograms were examined by one- and two-dimensional analyses with a laser densitometer. In order from the anodic side of the PAGE pattern, pre-albumin, hexokinase, tyrosinase, alkaline phosphatase, urease, and aldehyde dehydrogenase were assumed to be present based on Rf and Mw. Serum albumin, lactate dehydrogenase, and catalase appeared to be present based on a comparison of their electrophoretic mobility with that of protein standards of known Mw. Verification of beagle serum protein fractions by immunofixation electrophoresis and western blotting electrophoresis, with rabbit anti-human serum, indicated alpha 1-antitrypsin, albumin, haptoglobin, ceruloplasmin, C3c complement, IgG, and IgA. Serum protein fraction values (%) obtained by one- and two-dimensional analyses were similar.
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PMID:Analysis of a polyacrylamide gel electrophoretogram of beagle serum protein by laser densitometer. 765 Sep 2

Forty-nine haemodialyzed patients have been submitted consecutively, under informed consent, to endoscopy with multiple antral gastric mucosa biopsies for Helicobacter pylori (HP) identification, performed by urease, microscopic and cultural tests, as well as histologic examination. Patients have been considered HP negative when negative for all tests; positivity for HP has been correlated with gastritis histologically evaluated according to Whitehead; at endoscopy, blood samples for HP specific IgG, IgA, IgM have been collected; patient's life style concerning smoke, alcohol and drugs as FANS has been investigated as well. HP prevalence in our haemodialyzed patients is 38.8 per cent, similar to general population submitted to endoscopy; a statistically significant correlation between HP and gastritis and specific IgG, but no correlation between HP and age, dialysis duration, IgA, IgM, smoking, alcohol or drugs consumption has been found.
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PMID:[Helicobacter pylori in patients undergoing periodic hemodialysis]. 770 7


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