• Clinical and Experimental Pediatrics
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• v.45 no.7
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• pp.862-874
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• 2002

Purpose : We tried to evaluate whether the detection rate of Helicobacter pylori in gastric biopsy specimens could be improved by using pre-embedding immunoelectron microscopy. Methods : A total of 119 children who complained of upper gastrointestinal symptoms were endoscoped at the Gyeongsang National University Hospital from July, 1996 to July, 1999. Five biopsy specimens(three for urease test, one for hematoxylin-eosin(H & E) staining, and one for preembedding immunoelectron microscopy) were obtained from each antrum and body. Immunoblotting analysis were also performed. Results : Among the 119 patients, H. pylori were found in 116 patients(97.5%) by the immunoelectron microscopy. Among three patients who were found H. pylori negative in immunoelectron microscopy, two patients showed H. pylori in H & E stained slides and one patient was urease test positive(color change within six hours). Urease tests were positive in 107 patients(89.9 %). The positive rate of immunoblotting tests was 81.5%. However, only 13 patients(10.9%) showed H. pylori on the H & E stained antrum or body tissue. Conclusion : In this study, we found H. pylori histopathologically in most of the pediatric patients who complained of upper gastrointestinal symptoms. This study showed that pre-embedding immunoelectron microscopic examinations can be used as a gold standard in the diagnosis of childhood H. pylori infection. However, this method also has limited capacity to detect widely scattered H. pylori compared to the other histopathologic diagnostic methods.

• Korean Journal of Veterinary Research
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• v.29 no.4
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• pp.517-523
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• 1989

This study was undertaken to establish reliable diagnostic-procedures for the microbiological monitoring of laboratory animals. Murine(mice and rats) antibodies against hemagglutinating virus of Japan(HVJ), mouse hepatitis virus(MHV) and Mycoplasma pulmonis(Mp) were detected sensitively and specifically in experimentally and naturally infected animals' sera by an indirect enzyme-linked immunosorbent assay(ELISA), using urease conjugated antimurine immunoglobulin. The sensitivity and specificity of the complement fixation test which has been apllied widely for serodiagnosis of HVJ, MHV and Mp infections were apparently lower than those of ELISA. From these results, the ELISA was found to be available for the serodiagnosis of HVJ, MHV and Mp infections in mice and rats.

• Bulletin of the Korean Chemical Society
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• v.32 no.4
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• pp.1298-1302
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• 2011

This study describes the development of an electrochemical array immunochip for the detection of IgG. Interdigitated immunochip platforms were fabricated by sputtering gold on a glass wafer by using MEMS process and then were coated with Eudragit S100, an enteric polymer, forming an insulating layer over the working area of immunochips. The breakdown of the polymer layer was exemplified by the catalytic action of urease which, in the presence of urea, caused an alkaline pH change. This subsequently caused an increase of the double layer capacitance of the underlying electrode. Used in conjunction with a competitive immunoassay format, this allowed the ratio of initial to final electrode capacitance to be directly linked with the concentration of analyte, i.e. IgG. Responses to IgG could be detected at IgG concentration as low as $250\;ngmL^{-1}$ and showed good linearity up to IgG concentration as high as $20\;{\mu}gmL^{-1}$.

• Journal of Life Science
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• v.10 no.6
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• pp.630-639
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• 2000

The gastric pathogen Helicobacter pylori(H. pylori) establishes long-term chronic infection that can lead to atrophic gastritis, intestinal metaplasia, and gastric cancer. H. pylori, which express cytotoxic genes is now recohnized as a cause of peptic ulcer and is also a major risk factor for the development of gastric adenocarcinoma. We performed this study 1) to assess the detection rate of H. pylori according to direct investigation of bacteria of gastric biopsy specimen and two serologic tests of GAP test and Helico blot 2.0 system in the symptomatic and non-symptomatic group 2) to evaluate and compare the efficacy of two serologic tests of GAP test and Helico blot 2.0 system for the diagnosis of H. pylori infection. Forty-nine patients were positive for H pylori infection based on direct investigation of bacteria by histology. The detection rates of H. pylori infection based on direct investigation of bacteria by histology. The detection rates of H. phlori were significantly lower in gastric cancer than in other gastroduodenal disease(p<0.05). The concordance of two serologic tests of GAP test and Helico blot 2.0 system is poor. There was no statistically significant difference between the expression rate of CagA and VacA in the symptomatic and non-symptomatic group. Although Helico blot 2.0 system may not displace GAP test, it was a very sensitive serologic test for the diagnosis of H. pylori infection and it was used to detect IgG antibodies to H. pylori-specific antigens, including CagA, VacA and the various urease subunit. Our data suggest that further investigation is needed to determine whether or not the serologic expression of cytotoxic gene may be clinical usefulness of diagnostic methods in the gastroduodenal disease.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.19
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• pp.8295-8299
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• 2014

Background: H pylori is the main causative agent of Gastric cancer and chronic gastritis. Genetic diversity of H. pylori has major contribution in its pathogenesis. We investigated the prevalence of oipA and iceA1/iceA2 positive strains of H. pylori among patients with gastric cancer and gastritis. Materials and Methods: Sampling performed by means of endoscopy from 86 patients. DNA was extracted from tissue samples using DNA extraction kit. PCR assay was performed and products were monitored by Agarose Gel Electrophoresis. Results: Urease Test and 16S rRNA PCR did not show significant differences in detection of H. pylori. The frequency of iceA1 allele in patients with gastric cancer was significantly higher than those with gastritis (p<0.05). However, there was no significant difference in prevalence of oipA and iceA2 genes among the two groups of patients (p>0.05). Conclusions: The iceA1 gene, but the oipA and iceA2 genes, is associated with H. pylori-induced gastric cancer. However, confirmatory studies must be performed in future.

• Korean Journal of Microbiology
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• v.25 no.4
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• pp.346-352
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• 1987

One hundred and seventeen colonies were screened for the detection of the production of exodextranase on the dextran-mineral salts medium. Ten colonies out of them produced the dextranase. Flavobacterium multivorum greatly producing the enzyme was isolated from soil, identified and then studied for various biochemical characteristics. The activity of the dextranase in the cultured medium was high between pH8 and 9 at $35^{\circ}C$, and between $45^{\circ}C$ and $55^{\circ}C$ at pH8. By the growth curves the generation times of the bacterium were approximately 52 minutes in the LB broth, 38 minutes in the LB plus 1% dextran and 660 minutes in the dextran-salts. The strain did not have ant plasmid, and was susceptible to genramicin, cotrimoxazole and cefoperazone, and moderately susceptible to chloramphenicol, cefamandole and cefotaxime, but resistant to ampicillin, cephalothin, tetracycline, amikacin and tobramycin.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.6 no.2
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• pp.103-111
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• 2003

Purpose: This study was undertaken to evaluate the gastroduodenal pathology and Helicobacter pylori infection in children with upper gastrointestinal symptoms. Methods: One hundred and seven pediatric patients with upper gastrointestinal symptoms were undergone endoscopy at the Gyeongsang National University Hospital from June 1990 to April 1991. Histopathologic examination was done by H & E staining of gastric antral biopsy specimen and gastritis was defined according to the Sydney System. Tissue H. pylori status was evaluated with the urease test using Christensen's urea broth and H & E or Warthin-Starry silver staining of gastric antral biopsy specimen. IgG Immunoblotting were also performed to detect specific anti-H. pylori antibody in these patients. Results: The reasons for endoscopy were recurrent abdominal pain, acute abdominal pain, sallow face, hunger pain, and frequent nausea. Variable degrees of gastric mucosal hyperemia were found in most of the patients. Gastric hemorrhagic spots, gastric ulcer, duodenal ulcer, duodenal erosion, and hemorrhagic duodenitis were rare endoscopic findings. Histologic chronic gastritis was found in 88% of 107 patients. Histologic chronic duodenitis was observed in all 99 patients whose tissue were available. Gastric tissue H. pylori was positive in 57% of 107 patients by one of the ureasetest, H & E staining and Warthin-Starry silver staining. However, gastric tissue H. pylori detection rate was lower in the younger age groups. Anti-H. pylori IgG antibodies were detectable in 96% of 107 patients. Conclusion: Chronic gastroduodenitis and anti-H. pylori IgG antibody were ubiquitous in children with upper gastrointestinal symptoms.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.20
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• pp.9005-9008
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• 2014

Background: Gastric cancer is the second leading course of cancer death worldwide and H. pylori infection is an important risk factor for gastric cancer development. This study was design to evaluate the clinical, pathological features, survival rate and prevalence of H. pylori infection in gastric cancer in Thailand. Materials and Methods: Clinical information, histological features, endoscopic findings and H. pylori status were collected from gastric cancer patients from Thammasat university hospital during June 1996-December 2011. H. pylori infection was assessed by histological evaluation, rapid urease test and serological test. Clinical information, endoscopic findings and histopathology of all patients were recorded and compared between patients with active or non-active H. pylori infection. Results: A total of 100 gastric cancer patients (55 men and 45 women with mean age of $55{\pm}16.8years$) were enrolled in this study. Common presenting symptoms were dyspepsia (74%), weight loss (66%), anemia (63%) and anorexia (38%). Mean duration of symptoms prior to diagnosis was 98 days. Overall prevalence of H. pylori infection was 83% and active H. pylori infection was 40%. 1-year and 5-year survival rates were 43% and 0%. There was no significant difference between active H. pylori infection in different locations (proximal vs non-proximal: 47.1% vs 48.5%; P-value = 0.9, OR=0.9; 95%CI=0.3-3.1) and histology of gastric cancer (diffuse type vs intestinal type: 47.4% vs 50%; P-value = 0.8, OR=0.9, 95%CI=0.3-2.7). However, linitis plastica was significantly more common in non-active than active H. pylori infection (27.9% vs 0%; P-value<0.0001, OR=13.3, 95%CI=3.2-64.5). Moreover, gastric cancer stage 4 was higher in non-active than active H. pylori infection (93% vs 50%, P-value<0.001). Conclusions: Prevalence of H. pylori infection in Thai gastric cancer patients was high but active infection was low. Most gastric cancer patients presented in advance stage and had a grave prognosis. Screening for gastric cancer in high risk individuals might be an appropriate tool for early detection and improve the treatment outcome for this particular disease in Thailand.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.7 no.2
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• pp.153-162
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• 2004

Purpose: The Helicobacter pylori stool antigen (HpSA) enzyme immunoassay is a non-invasive test for the diagnosis and monitoring of H. pylori infection. But, there are few validation studies on the HpSA test after eradication in children. The aim of this study was to assess the diagnostic accuracy of HpSA enzyme immunoassay for the detection of H. pylori to confirm eradication in children. Methods: From January 2001 to October 2003, 164 tests were performed in 146 children aged 1 to 17.5 years (mean $9.3{\pm}4.3$ years). H. pylori infection was confirmed by endoscopy-based tests (rapid urease test, histology, and culture). All H. pylori infected children were treated with quadruple regimens (Omeprazole, amoxicillin, metronidazole and bismuth subcitrate for 7 days). Stool specimens were collected from all patients for the HpSA enzyme immunoassay (Primier platinum HpSA). The results of HpSA tests were interpreted as positive for $OD{\geq}0.160$, unresolved for $$0.140{\leq_-}OD$$<0.160, and negative for OD<0.140 at 450 nm on spectrophotometer. Results: 1) One hundred thirty-one HpSA tests were performed before treatment. The result of HpSA enzyme immunoassay showed three false positive cases and one false negative case. The sensitivity, specificity, positive predictive value, and negative predictive value of HpSA enzyme immunoassay before treatment were 96.4%, 97.1%, 90%, and 99%, respectively. 2) Thirty-three HpSA enzyme immunoassay were performed at least 4 weeks after eradication therapy. The results of HpSA enzyme immunoassay showed two false positive cases and one false negative case. The sensitivity, specificity, positive predictive value, and negative predictive value after treatment were 88.9%, 91.7%, 80%, and 95.7%, respectively. Conclusion: Diagnostic accuracy of the HpSA enzyme immunoassay after eradication therapy was as high as that of the HpSA test before eradication therapy. The HpSA enzyme immunoassay was found to be a useful non-invasive method to confirm H. pylori eradication in children.