Diagnosis of Helicobacter pylori Infection in Children: Comparison of a Salivary Immunoglobulin G Antibody Test with the [13C]Urea Breath Test

The prevalence of Helicobacter pylori infection in a population-based sample of 477 children (mean age ± standard deviation, 5.8 ± 0.5 years) determined by the [¹³C]urea breath test ([¹³C]UBT) was 10.7% (95% confidence interval [CI], 8.1 to 13.8%), and that determined by salivary enzyme-linked immunosorbent assay (ELISA) was 11.9% (95% CI, 9.2 to 15.2%). Compared to the [¹³C]UBT, the sensitivity and specificity of the salivary ELISA were 80.9% (95% CI, 66.3 to 90.4%) and 95.3% (95% CI, 92.7 to 97.1%), respectively.     

Application of a Stool Antigen Test To Evaluate the Incidence of Helicobacter pylori Infection in Children and Adolescents from Tehran, Iran

Helicobacter pylori infection is acquired mainly in childhood, especially in developing countries, where a low-cost, rapid diagnostic technique which is reliable for all age groups may be useful for the management of H. pylori infection. For this purpose, we used an HpSA test (Equipar) to detect H. pylori infection in children and adolescents from Tehran, Iran. Thirty-five children who were positive or negative for H. pylori infection by endoscopy-based tests were used as positive and negative controls for the HpSA test. Stools were collected from 430 randomly selected children and adolescents (4 to 18 years old) from southwest, near the center, and northwest of Tehran. A questionnaire that included presence of recurrent abdominal pain (RAP), family history of infection and/or peptic ulcer disease (PUD), and income of parents was completed. A good agreement was found between the results of endoscopy-based tests and those of the HpSA test; the sensitivity and specificity of the Equipar-HpSA test were 100% and 83.4%, respectively. Among 430 children and adolescents, 47% were positive by the HpSA test, of whom 82% had RAP. No difference in incidence was observed between the two sexes; the various categories of age showed an increasing incidence, ranging from 24% (ages 4 to 6) to 58% (ages 16 to 18). The rate of infection in children and adolescents from the southwest was significantly higher (70%) than the rate in those from the northwest (32%), and a family history of H. pylori infection or PUD was observed in 59% of the HpSA positive subjects. The HpSA test is a useful test to detect H. pylori infection in children and adolescents from developing countries.     

Evaluation of a Helicobacter pylori Stool Antigen Test for the Diagnosis and Follow-Up of Infections in Children

 The aim of this study was to evaluate the performance of a newly developed enzyme immunoassay kit (HpSA) for detecting Helicobacter pylori antigens in the stool of children. This study was comprised of 58 children referred to various endoscopy units for evaluation of gastrointestinal symptoms and upper gastroduodenal endoscopy and 11 children for post-therapy follow-up. In the first group, 23 children were diagnosed as positive for Helicobacter pylori using bacteriological and/or histological methods. Stool antigens were detected in 20 of these positive patients, for a sensitivity of 86.9% and a negative predictive value of 91.9%. Since only one false-positive reaction was observed with the HpSA kit, the specificity was 97.1% and the positive predictive value 95.2%. Results obtained for post-therapy follow-up were also promising. The HpSA assays were negative for the eight children whose infections were eradicated after therapy, and a positive result was obtained for two of three patients who had a persistent infection.     

Evaluation of [13C]urea breath test and Helicobacter pylori stool antigen test for diagnosis of H. pylori infection in children from a developing country

The [(13)C]urea breath test ((13)C-UBT) and Helicobacter pylori stool antigen test (HpSA) for the diagnosis of H. pylori infection in children were validated. The sensitivity, specificity, and positive and negative predictive values were 93.8, 99.1, 97.8, and 98.0%, respectively, for the (13)C-UBT and 96.9, 100, 100, and 98.0%, respectively, for HpSA. Both tests are appropriate for diagnosing H. pylori infection in children.     

Helicobacter pylori stains and association between H. pylori and inflammation in gastric specimens

Gastric cancer has been strongly associated with presence of the bacterium Helicobacter pylori. To improve techniques in identifying H. pylori so that gastric cancer may be predicted early, this project was formulated to determine whether one particular stain is more effective in displaying H. pylori microscopically. In addition, this study attempted to determine whether the degree of inflammatory elements present in tissue could be used to predict the likelihood of H. pylori presence. Protocols for the staining techniques, Steiner and alcian yellow/toluidine blue (AY/TB), were employed on specimens to semi-quantitate H. pylori presence. Serial sections from the same specimens were stained with hematoxylin and eosin to determine the amount of inflammation. Spearman rho correlation was used to evaluate the association between amount of H. pylori and inflammation in each case. It was determined that AY/TB was more easily performed, more effective in demonstrating H. pylori, and more cost effective than the Steiner stain. Additionally, it was determined that a moderate positive association was indicated between high levels of inflammation and marked presence of H. pylori.     

Helicobacter pylori persistence: an overview of interactions between H. pylori and host immune defenses

Helicobacter pylori is a gram-negative bacterium that persistently colonizes more than half of the global human population. In order to successfully colonize the human stomach, H. pylori must initially overcome multiple innate host defenses. Remarkably, H. pylori can persistently colonize the stomach for decades or an entire lifetime despite development of an acquired immune response. This review focuses on the immune response to H. pylori and the mechanisms by which H. pylori resists immune clearance. Three main sections of the review are devoted to (i) analysis of the immune response to H. pylori in humans, (ii) analysis of interactions of H. pylori with host immune defenses in animal models, and (iii) interactions of H. pylori with immune cells in vitro. The topics addressed in this review are important for understanding how H. pylori resists immune clearance and also are relevant for understanding the pathogenesis of diseases caused by H. pylori (peptic ulcer disease, gastric adenocarcinoma, and gastric lymphoma).     

Correlation between Positive Rate and Number of Biopsy Samples on Urease Test in Childhood Helicobacter pylori Infection

To identify the correlation between the number of gastric biopsy samples and the positive rate, we compared the results of urease test using one and three biopsy samples from each 255 children who underwent gastroduodenoscopy at Gyeongsang National University Hospital. The children were divided into three age groups: 0-4, 5-9, and 10-15 yr. The gastric endoscopic biopsies were subjected to the urease test. That is, one and three gastric antral biopsy samples were collected from the same child. The results of urease test were classified into three grades: Grade 0 (no change), 1 (6-24 hr), 2 (1-6 hr), and 3 (<1 hr). The positive rate of urease test was increased by the age with no respect to the number of gastric biopsy samples (one biopsy P = 0.001, three biopsy P < 0.001). The positive rate of the urease test was higher on three biopsy samples as compared with one biopsy sample (P < 0.001). The difference between one and three biopsy samples was higher in the children aged 0-9 yr. Our results indicate that the urease test might be a more accurate diagnostic modality when it is performed on three or more biopsy samples in children.     

Determination of isotopic enrichments of [1-13C]homocysteine, [1-13C]methionine and [2H3-methyl-1-13C]methionine in human plasma by gas chromatography-negative chemical ionization mass spectrometry

We describe a reliable method for the simultaneous determination of isotopic enrichments of [1-13C]homocysteine, [1-13C]methionine and [2H3-methyl-1-13C]methionine in human plasma. Accurate [1-13C]homocysteine calibration standards were prepared by chemical conversion via thiolactonisation of [1-13C]methionine standards. Based upon anion-exchange chromatography, (di)acetyl-3,5-bis-trifluoromethylbenzyl derivatives, preparation of accurate calibration curves and gas chromatography-negative chemical ionization mass spectrometry, isotopic enrichments in human plasma could be determined with TTR (%) <+/-0.2% (N=3) for [1-13C]homocysteine (enrichment range 0-8%), [1-13C]methionine (enrichment range 0-3%) and [2H3-methyl-1-13C]methionine (enrichment range 0-12%). The method was applied in a [2H3-methyl-1-13C]methionine tracer infusion study in a biological model.     

Estimation of prevalence of Helicobacter pylori infection in an asymptomatic elderly population comparing [14C] urea breath test and serology.

A non-invasive serological assay devised in this laboratory had a sensitivity and specificity of 100% as determined by culture and confirmed by histology in a group of 47 patients who had undergone endoscopy. The correlation between serology and the non-invasive [14C] breath test was very good. Only one of 24 culture positive patients was, while all 23 culture negative patients were, breath test negative. In a group of 46 healthy elderly persons, however, significant anomalies between serology and breath test were observed. Only 83% of the breath test negative persons were seronegative, while only 68% of the breath test positive persons were seropositive. These results can be explained in terms of age related atrophic gastritis and immune incompetence, causing reduced colonisation and decreased antibody production, respectively. These investigations suggest that non-invasive tests for H pylori infection may not be reliable in the elderly.     

Helicobacter pylori infection in indigenous families of Central America: serostatus and oral and fingernail carriage.

Helicobacter pylori infection remains one of the most common in humans, but the route of transmission of the bacterium is still uncertain. This study was designed to elucidate possible sources of infection in an isolated, rural population in Guatemala. A total of 242 subjects in family units participated in the study. A medical history, including a history of dyspepsia, was taken by a physician and immunoglobulin G antibodies to H. pylori were detected with the QuickVue (Quidel, San Diego, Calif.) onsite serology test. Overall, 58% of subjects were seropositive, with a positive relationship between mother and child (P = 0.02) and a positive correlation between the serostatuses of siblings (intraclass correlation coefficient = 0.63). There was no association between serostatus and gastric symptoms. Oral H. pylori was detected from periodontal pockets of various depths and the dorsum of the tongue by nested PCR. Eighty-seven percent of subjects had at least one oral site positive for H. pylori, with the majority of subjects having multiple positive sites. There was no association between periodontal pocket depth and the detection of H. pylori. Nested PCR was also used to detect H. pylori from beneath the nail of the index finger of each subject's dominant hand. Overall, 58% of subjects had a positive fingernail result, with a significant positive relationship between fingernail and tongue positivity (P = 0.002). In conclusion, the results of this study suggest that oral carriage of H. pylori may play a role in the transmission of infection and that the hand may be instrumental in transmission.     

In vivo 1H, 31P-[1H] and 13C-[1H] magnetic resonance spectroscopy of malignant histiocytoma and skeletal muscle tissue in man.

Human tumor and skeletal muscle tissue was studied by means of in vivo 1H, 31P, and 13C MRS. The examinations were performed with a 1.5 T whole-body MR scanner equipped with a second RF system. Localized 1H and broadband proton-decoupled 31P and 13C MR spectra were obtained in measurement times of 5, 10 and 33 min, respectively, from a malignant fibrous histiocytoma in a patient and from gastrocnemius muscle tissue in healthy volunteers. Proton decoupling enhanced the sensitivity (via the nuclear Overhauser effect) and the information available from in vivo 31P and 13C MR spectra significantly. The most information was obtained from 1H-decoupled 31P spectra. Observation of more than one spin species allows peak assignments to be verified mutually. The spectral data of the histiocytoma differ largely from that of muscle tissue and show a tumor with elevated pH value, normal level of nucleoside 5'-triphosphates, and high level of compounds involved in phospholipid turnover. The multinuclear in vivo MRS experiment may allow the non-invasive observation of almost the complete pathway of phospholipid synthesis and degradation in intact human tissue.     

State of the art direct 13C and indirect 1H-[13C] NMR spectroscopy in vivo. A practical guide

Carbon-13 NMR spectroscopy in combination with (13)C-labeled substrate infusion is a powerful technique for measuring a large number of metabolic fluxes noninvasively in vivo. It has been used to quantify glycogen synthesis rates, establish quantitative relationships between energy metabolism and neurotransmission, and evaluate the importance of different substrates. Measurements can, in principle, be performed through direct (13)C NMR detection or via indirect (1)H-[(13)C] NMR detection of the protons attached to (13)C nuclei. The choice of detection scheme and pulse sequence depends on the magnetic field strength, whereas substrate selection depends on metabolic pathways. (13)C NMR spectroscopy remains a challenging technique that requires several nonstandard hardware modifications, infusion of (13)C-labeled substrates, and sophisticated processing and metabolic modeling. In this study, the various aspects of direct (13)C and indirect (1)H-[(13)C] NMR are reviewed with the aim of providing a practical guide.     

Diagnosis of Helicobacter pylori infection in children: comparison of a salivary immunoglobulin G antibody test with the [(13)C]urea breath test

The prevalence of Helicobacter pylori infection in a population-based sample of 477 children (mean age plus minus standard deviation, 5.8 plus minus 0.5 years) determined by the [(13)C]urea breath test ([(13)C]UBT) was 10.7% (95% confidence interval [CI], 8.1 to 13.8%), and that determined by salivary enzyme-linked immunosorbent assay (ELISA) was 11.9% (95% CI, 9.2 to 15.2%). Compared to the [(13)C]UBT, the sensitivity and specificity of the salivary ELISA were 80.9% (95% CI, 66.3 to 90.4%) and 95.3% (95% CI, 92.7 to 97.1%), respectively.     

Metabolism of D-[1-(13)C]fructose, D-[2-(13)C]fructose, and D-[6-(13)C]fructose in rat hepatocytes incubated in the presence of H(2)O or D(2)O

Isolated hepatocytes from fed rats were exposed for 120 min to D-[1-(13)C]fructose, D-[2-(13)C]fructose, or D-[6-(13)C]fructose in the presence of H(2)O or D(2)O. The identification and quantification of (13)C-enriched metabolites (D-glucose, L-lactate) in the incubation medium and the measurement of their deuterated isotopomers indicated that the ketohexose was phosphorylated predominantly at the intervention of fructokinase and that the majority of the D-glyceraldehyde molecules generated from d-fructose 1-phosphate were further metabolized, e.g., after phosphorylation to D-glyceraldehyde 3-phosphate. It is proposed that the present procedure may help to further characterize the regulation of D-fructose metabolism in both hepatocytes and other cell types.     

Evaluation of Helicobacter pylori in gastric MALT-type lymphoma: differences between histologic and serologic diagnosis.

Helicobacter pylori provides the pathogenic background for the development of gastric MALT-type lymphoma. The assessment of H. pylori is limited by the accuracy of the detection method used. Especially in patients with low-grade MALT-type lymphoma, the H. pylori status is the crucial question for therapeutic management. In this study, 60 patients with gastric MALT-type lymphoma. (lowgrade, 22; high-grade, 38) were investigated for the presence of H. pylori by histologic and serologic means. In 98% of the patients with MALT-type lymphoma, H. pylori-specific IgG serum antibodies were detected. In contrast, on histologic examination, H. pylori was found only in 78% of the patients (low-grade, 77%; high-grade, 79%). In this study, a discrepancy between serologic and histologic evaluation of the H. pylori status in gastric MALT-type lymphoma was found. Therefore, a H. pylori eradication therapy in low-grade MALT-type lymphoma, which often leads to a complete tumor regression, should not be excluded as a first line therapy because of a negative H. pylori status on histologic examination.     

Differences in virulence markers between Helicobacter pylori strains from Iraq and those from Iran: potential importance of regional differences in H. pylori-associated disease

Helicobacter pylori causes peptic ulceration and gastric adenocarcinoma; the latter is common in Iran but not in Iraq. We hypothesized that more virulent H. pylori strains may be found in Iran than in Iraq and so compared established and newly described virulence factors in strains from these countries. We studied 59 unselected dyspeptic patients from Iran and 49 from Iraq. cagA was found in similar proportions of strains from both countries (76% in Iran versus 71% in Iraq) and was significantly associated with peptic ulcer disease in Iraq (P 相似文献   

Evidence for interactions between [3H]glutamate and [3H]kainic acid binding sites in rat striatal membranes. Possible relevance for kainic acid neurotoxicity

The projection of the substantia nigra-ventral tegmental area (SN-VTA) to the ipsilateral and contralateral caudate-putamen was studied with double-labeling fluorescence techniques in the albino rat. By combining glyoxylic acid histofluorescence with retrograde fluorescence tracers, we were able to determine that 93% of the minor (1–2%) contralateral mesostriatal pathwayis catecholaminergic. In addition, combined immunofluorescence and retrograde fluorescence tracer studies showed that 50% of the crossed mesostriatal pathway also arises from cholecystokinin-containing neurons. These results provide evidence for crossed catecholamine- and peptide-containing pathways in the mesostriatal system which is part of the ‘prefrontal system’ that links the prefrontal cortex through the caudate-putamen, with the thalamus and tectum of each hemisphere.     

Postischemic binding of [3H]phorbol 12,13-dibutyrate and [3H]inositol 1,4,5-trisphosphate in the gerbil brain: an autoradiographic study.

Postischemic alteration of second messenger systems was investigated in the Mongolian gerbil, utilizing [3H]phorbol 12,13-dibutyrate and [3H]inositol 1,4,5-trisphosphate receptor autoradiography. Transient ischemia was induced for 10 min, and animals were allowed to survive for various recirculation periods of up to one month. [3H]Phorbol 12,13-dibutyrate binding in selectively vulnerable areas showed no significant change 1-24 h after ischemia except for a transient decline in a few regions. Thereafter, the binding in most of the selectively vulnerable areas showed significant alteration 48 h or seven days after ischemia. Interestingly, dentate molecular layer which was resistant to ischemia showed a significant elevation in the number of [3H]phorbol 12,13-dibutyrate binding sites. One month after ischemia, [3H]phorbol 12,13-dibutyrate binding showed significant reduction only in the striatum and the hippocampal CA1 sector where severe neuronal damage was seen morphologically. A significant elevation in the number of [3H]phorbol 12,13-dibutyrate binding sites was still seen in the dentate molecular layer one month after ischemia. In contrast, [3H]inositol 1,4,5-trisphosphate binding showed significant reduction in the selectively vulnerable regions 1-24 h after ischemia. Thereafter, [3H]inositol 1,4,5-trisphosphate binding in most of the selectively vulnerable areas markedly decreased up to one month after ischemia. In the dentate molecular layer, [3H]inositol 1,4,5-trisphosphate binding also showed significant reduction during recirculation except for a slight recovery 48 h and seven days after ischemia. One month after ischemia, the binding in all regions showed significant reduction. These results suggest that postischemic alteration of two second messenger (protein kinase C and inositol 1,4,5-trisphosphate) binding sites was produced with different processes in selectively vulnerable areas.(ABSTRACT TRUNCATED AT 250 WORDS)     

Estimation of glucose turnover and recycling in rabbits using various [3H, 14C]glucose labels.

The glucose replacement rate, percent carbon recycling, mean glucose transit time, and the glucose mass were determined in fasted unanesthetized rabbits after administration of [2-3H,U-14C]-, [3-3H,U-14C]-, [5-3H,U-14C]- or [6-3H,U-14C]glucose using the procedures of Katz et al. (10). The glucose replacement rates and carbon recycling determined with [2-3H,U-14C] and [5-3H,U-14C]glucose are equivalent and greater than those obtained with [3-3H,U-14C]- and [6-3H,U-14C]glucose. Although the means of the glucose replacement rates and percent carbon recycling obtained using [3-3H,U-14C]- and [6-3H,U-14C]glucose are similar, greater variation resulted using the former tracer. Comparisons of detritiation rates and percent carbon recycling using [2-3H,U-14C]- and [6-3H,U-14C]glucose suggest that about 10% of tritium is lost from carbon 2 via futile cycling at the glucose 6-phosphate level. Similarly, comparisons of [5-3H,U-14C]- and [6-3H,U-14C]glucose metabolism suggest that about 10% of tritium lost from carbon 5 occurs via futile cycling at the fructose diphosphate level and/or via the transaldolase reaction. Our results indicate that [6-3H,U-14C]glucose is the more suitable tracer for determining the glucose replacement rate and carbon recycling in vivo.