Publications (22)54.37 Total impact
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Article: Multi locus sequence typing for the analysis of intra-familial transmission of Helicobacter pylori by using faecal specimens.
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ABSTRACT: We have used Multi locus sequence typing (MLST) of total DNA extracted from fecal specimens to genotype Helicobacter pylori to analyse intra-familial transmission. Faecal DNA was extracted and amplified by nested PCR. The products were analysed by direct sequencing and the allele type was determined using the MLST website. Mother-to-child transmission was suspected in 2 of 3 families, and father-child transmission was detected in one family.Journal of Medical Microbiology 02/2013; · 2.50 Impact Factor -
Article: Diagnostic accuracy of urine-based kits for detection of Helicobacter pylori antibody in children.
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ABSTRACT: BACKGROUND: Rapid urine-HpAb is reported to be a reliable test of H. pylori infection in adults, but there is no data on the application of the test in children. Objective. To evaluate the accuracy of a urine-based ELISA (urine-HpELISA) and immunochromatography (rapid urine-HpAb) kit for anti-H. pylori IgG antibody in children, we compared its sensitivity and specificity in reference to the (13) C-urea-breath test (UBT) and H. pylori stool antigen test (HpSA). MATERIALS AND METHODS: 101 Japanese children without significant upper-abdominal symptoms were included (mean age, 7.1 years; range 2 to 15 years). Their sensitivity and specificity were evaluated in reference to the (13) C-urea breath test (UBT) and H. pylori stool antigen test (HpSA). RESULTS: 37 children were judged H. pylori-positive and 64 negative by UBT and HpSA. No discrepancy in the results was observed between UBT and HpSA. Urine-HpELISA showed 91.9% sensitivity and 96.9% specificity with an accuracy of 95.0%. Rapid urine-HpAb showed 78.4% sensitivity and 100% specificity with an accuracy of 92.1%. Seven false-negative results for rapid urine-HpAb were from children aged under 10 years, and their antibody titers of urine-HpELISA were lower than true-positives. CONCLUSIONS: For the diagnosis of H. pylori infection in Japanese children, the both tests may be non-invasive, inexpensive, reliable and easy-to-perform methods giving satisfactory accuracy, although the sensitivity of the rapid urine-HpAb kit was inferior to that of the urine-HpELISA kit, especially in children aged under 10 years showing relatively low titer of H. pylori antibody.Pediatrics International 01/2013; · 0.63 Impact Factor -
Article: Fragmented CagA protein is highly immunoreactive in Japanese patients.
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ABSTRACT: High-molecular-weight cell-associated proteins (HM-CAP) assay is the most popular serological immunoassay worldwide and has been developed from US isolates as the antigens. The accuracy is reduced when the sera are from adults and children in East Asia including Japan. To overcome the reduced accuracy, an enzyme immunoassay using Japanese strain-derived HM-CAP (JHM-CAP) was developed, in which the antigens were prepared by exactly the same procedure as HM-CAP. The performance of JHM-CAP was better than that of HM-CAP in Japanese adults as well as in children. The higher sensitivity was because of the presence of 100-kDa protein that was absent in the preparation of HM-CAP antigen. Immunoblot analysis and peptide mass fingerprinting methods were used to identify the distinctive 100-kDa protein present in JHM-CAP antigens. The peptide sequence and identification were analyzed by Mascot Search on the database of Helicobacter pylori. The identified protein was confirmed by immunoblot with a specific antibody and inhibition assay by the sera. The distinctive 100-kDa protein was a fragment of CagA derived from Japanese clinical isolates, and the sera of Japanese patients had strongly reacted to the protein, probably to the exposed epitope on the fragmented CagA. The fragmentation of CagA had occurred in the process of antigen preparation in Japanese isolates, not in US isolates even under the same preparation. The distinctive 100-kDa protein was a fragment of CagA protein of H. pylori derived from Japanese clinical isolates, and Japanese patients including children are likely to react strongly to the exposed epitopes on fragmented CagA.Helicobacter 06/2012; 17(3):187-92. · 3.15 Impact Factor -
Article: Influence of proton pump inhibitor treatment on Helicobacter pylori stool antigen test.
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ABSTRACT: To investigate the effects of proton pump inhibitor (PPI) treatment on stool antigen test using the TestMate pylori enzyme immunoassay. This study assessed 28 patients [16 men and 12 women; mean age (63.1 ± 5.9) years; range, 25-84 years] who underwent stool antigen test and urea breath test (UBT) before and after PPI administration. Using the UBT as the standard, the sensitivity, specificity and agreement of the stool antigen test in all 28 patients were 95.2%, 71.4%, and 89.3%, respectively, before PPI administration, and 88.9%, 90.9%, and 89.3%, respectively, after PPI treatment. Mean UBT values were 23.98% ± 5.33% before and 16.19% ± 4.75% after PPI treatment and, in 15 patients treated for ≥ 4 wk, were significantly lower after than before 4 wk of PPI treatment (12.58% ± 4.49% vs 24.53% ± 8.53%, P = 0.048). The mean optical density (A(450/630)) ratios on the stool antigen test were 1.16 ± 0.20 before and 1.17 ± 0.24 after PPI treatment (P = 0.989), and were 1.02 ± 0.26 and 0.69 ± 0.28, respectively, in the group treated for > 4 wk (P = 0.099). The stool antigen test was equally sensitive to the UBT, making it a useful and reliable diagnostic method, even during PPI administration.World Journal of Gastroenterology 01/2012; 18(1):44-8. · 2.47 Impact Factor -
Article: [Helicobacter pylori infection in childhood].
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ABSTRACT: Helicobacter pylori (H. pylori) infection is mainly acquired in the first 2 or 3 years and the risk of infection declines rapidly after 5 years of age. In developing countries, acquisition age of the infection is probably lower than in developed countries. In Japan, main transmission route is intrafamilial and mother to children infection is most important. But in developing countries, some reports suggest that extrafamilial infection is more important. The famous paper revealed that H. pylori can be cultivated from vomitus, saliva and cathartic stools and the possibility of source of H. pylori infection. Bed sharing, large number of family members, delayed weaning from a feeding bottle, regurgitated gastric juice in the mother's mouth are reported as risk factors of the infection.Nippon rinsho. Japanese journal of clinical medicine 12/2009; 67(12):2239-44. -
Article: Modified allele-specific primer-polymerase chain reaction method for analysis of susceptibility of Helicobacter pylori strains to clarithromycin.
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ABSTRACT: Most clarithromycin-resistant strains of Helicobacter pylori have a mutation from adenine (A) to guanine (G) at position 2142 or 2143 of the 23S rRNA gene. Our aim in this study was to develop a polymerase chain reaction (PCR)-based assay that could determine these mutations in a single reaction tube. We designed the forward primer FP2143G and the reverse primer RP2142G, which specifically anneal with the 2143G- and 2142G-mutated sequences, respectively, of the 23S rRNA gene of H. pylori. We also designed the forward primer FP-1 and reverse primer RP-1 upstream and downstream from the positions 2142 and 2143, respectively, to distinguish the wild-type A2142G and A2143G mutations from each other by amplicon sizes. DNA was extracted from 292 gastric tissue samples positive for rapid urease test, and the DNA underwent the PCR reaction. The results were compared with minimum inhibitory concentrations (MIC) for clarithromycin. Helicobacter pylori strains with A2142G, A2143G and wild type could be distinguished by amplicon sizes by a single PCR reaction. The genotyping results were correlated well with the MIC values for clarithromycin. The median MIC for clarithromycin of the wild-type strains was <0.015 microg/mL. Those of strains with 2142G or 2143G were > or =1.0 microg/mL. Our new PCR-based assay for 23S rRNA mutations of H. pylori is a useful method for detecting clarithromycin-resistant strains of H. pylori easily.Journal of Gastroenterology and Hepatology 12/2007; 22(11):1810-5. · 2.87 Impact Factor -
Article: Helicobacter pylori colonization in the first 3 years of life in Japanese children.
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ABSTRACT: Acquisition of Helicobacter pylori infection occurs in early childhood, but the exact time of the acquisition and dynamics of infection are not clear. The aim of this study was to estimate the time of acquisition of H. pylori colonization in infants. This prospective follow-up study included 237 infants born in Wakayama Rosai Hospital from February, 2001 to April, 2002. Stool samples were collected at indicated ages, and H. pylori antigens were determined by a stool antigen test, HpSA. One-hundred and eight infants among initially enrolled 237 children have been followed up until 24 months. Among these, 16 infants turned to be HpSA positive within 12 months, but only four remained positive by the consecutive tests with optical density values of more than 0.7. They were assumed persistent positives. The rest 12 infants reverted to be negative by the consecutive tests and were assumed transient or false-positives. The optical density values of HpSA in the transient cases were exclusively less than 0.35. The consecutive follow up of HpSA, but not the one-point test, might be useful to diagnose persistent colonization of H. pylori in young infants, and some infants seemed to acquire H. pylori infection in the first year of life. These results should be taken into account for prevention and treatment strategies for H. pylori infection in infants.Helicobacter 09/2007; 12(4):324-7. · 3.15 Impact Factor -
Article: Bovine lactoferrin is effective to suppress Helicobacter pylori colonization in the human stomach: a randomized, double-blind, placebo-controlled study.
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ABSTRACT: Bovine lactoferrin (bLF) has antibacterial activity against Helicobacter pylori in vitro and is effective to suppress bacterial colonization in mice. The aim of our study was to evaluate the efficacy of orally administered bLF on H. pylori colonization in humans by a randomized, double-blind, placebo-controlled study. Fifty-nine healthy subjects positive for H. pylori infection were recruited. Subjects were randomized into two groups. The bLF group received bLF tablets at a dosage of 200 mg b.i.d. for a period of 12 weeks, and the control group received placebo tablets without bLF. The (13)C-urea breath test (UBT) was performed before, during, and at the end of administration, and again 4 weeks after administration. Positive response was defined as more than 50% decrease of the UBT value at the end of administration. Positive response was observed in 10 of 31 bLF-treated subjects (32.3%) and 1 of 28 control subjects (3.6%), indicating that the rate of positive response in the bLF group was significantly higher than that in the control group (bLF vs. control, P < 0.01). These results suggested that bLF administration is effective to suppress H. pylori colonization.Journal of Infection and Chemotherapy 01/2006; 11(6):265-9. · 1.80 Impact Factor -
Article: [Transmission route of H. pylori].
Nippon rinsho. Japanese journal of clinical medicine 12/2005; 63 Suppl 11:172-6. -
Article: [Effect of lactoferrin on H. pylori colonization].
Nippon rinsho. Japanese journal of clinical medicine 12/2005; 63 Suppl 11:577-81. -
Article: A strain-specific antigen in Japanese Helicobacter pylori recognized in sera of Japanese children.
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ABSTRACT: An enzyme immuno assay (EIA) test based on Japanese strain-derived high-molecular-weight cell-associated proteins (JHM-CAP) was evaluated by comparing with a previously developed EIA test based on a U.S. strain-derived high-molecular-weight cell-associated proteins (HM-CAP). Serum samples of 131 Japanese asymptomatic children (mean age, 5.5 years; range, 0 to 21 years) were tested that include 43 positive and 88 negative children as judged by Helicobacter pylori stool antigen test (HpSA test). Both tests showed comparable and reliable specificities, but the sensitivity of JHM-CAP EIA, at 93.0%, was much higher than that of HM-CAP EIA, at 67.4%. More false-negative results of HM-CAP were obtained in children under 10 years of age. Immunoblot analysis revealed that the JHM-CAP but not the HM-CAP preparation had a 100-kDa antigen recognized by JHM-CAP positive sera. It was concluded that JHM-CAP EIA is highly accurate for the serodiagnosis of H. pylori infection in Japanese young children and that the high sensitivity of JHM-CAP EIA in contrast to HM-CAP EIA is due to the presence of a 100-kDa antigen in Japanese strains that may be recognized by the host immune system at an early stage of infection.Clinical and Diagnostic Laboratory Immunology 12/2005; 12(11):1280-4. · 2.51 Impact Factor -
Article: Helicobacter pylori infection in children with chronic idiopathic thrombocytopenic purpura.
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ABSTRACT: Recently a high prevalence of Helicobacter pylori infection has been reported in adult patients with chronic idiopathic thrombocytopenic purpura (cITP). Furthermore, after H. pylori eradication therapy in such patients, their platelet counts have been observed to increase, suggesting that H. pylori may be a causative agent of adult cITP. However, there have been only a few reports of children with cITP. The purpose of the present paper was to examine the association between H. pylori infection and cITP in Japanese children. Helicobacter pylori stool antigens (HpSA) were measured and the prevalence of H. pylori infection was determined in 10 children with cITP. Helicobacter pylori infection was found in only two of the subjects. In a boy, the urea breath test (UBT) was also positive and the patient received eradication therapy using amoxicillin, clarithromycin, and lansoprazole for 1 week. The therapy was successful and the patient's platelet count increased. The response was maintained throughout more than 1 year of follow up. The prevalence of H. pylori infection in children with cITP is not high. However, the platelet count increased after eradication therapy in a boy with cITP. It is suggested that the eradication of H. pylori infection would be valuable in children, as well as in adults, with cITP.Pediatrics International 07/2005; 47(3):292-5. · 0.63 Impact Factor -
Article: Polymerase chain reaction--restriction fragment length polymorphism analysis of clarithromycin-resistant Helicobacter pylori infection in children using stool sample.
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ABSTRACT: To analyze clarithromycin-resistant Helicobacter pylori infection in children, we developed a method of polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis using stool samples. Twenty-three children without significant upper abdominal symptoms were included (mean age 7.0 years). Of these, 18 and five were diagnosed as H. pylori-positive and -negative, respectively, by the H. pylori stool antigen test (HpSA). The DNA from the stool samples was purified using the QIAamp DNA Stool Minikit (QIAGEN). The PCR was performed on the purified DNA using oligonucleotide primers designed to amplify the 23S rRNA gene of H. pylori. The PCR products were reacted with restriction enzymes MboII, BceAI, and BsaI to detect mutations A2142G, A2142C, and A2143G, respectively. Sixteen of the 18 HpSA-positive samples were PCR-positive, and all five HpSA-negative samples were PCR-negative. Thus, the PCR had 89% sensitivity and 100% specificity, with 91% accuracy in reference to HpSA. Of the 16 PCR-positive samples, one and four were digested with MboII and BsaI, respectively, indicating 31% prevalence of CAM-resistance. We conclude that the PCR-RFLP using stool samples is a rapid and reliable method to noninvasively detect clarithromycin-resistant H. pylori infection in children. It may be useful before choosing regimens of H. pylori eradication.Helicobacter 07/2005; 10(3):205-13. · 3.15 Impact Factor -
Article: Macrophage activation syndrome in children with systemic-onset juvenile chronic arthritis.
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ABSTRACT: Macrophage activation syndrome (MAS) is a life-threatening complication in children with rheumatic diseases, particularly systemic-onset juvenile chronic arthritis (SOJCA). Because of the potential fatality of this condition, prompt recognition and immediate therapeutic intervention are important. This study assessed the clinical features of nine MAS events in five children with SOJCA. Nonremitting fever and decreased platelet and white blood cell counts led to a diagnosis of MAS. The urinary beta2-microglobulin (beta2MG) level was a sensitive indicator of MAS. Serum levels of beta2MG and soluble interleukin-2 receptor were also elevated. These biologic markers reflecting hyperactivated cellular immunity are useful indicators of MAS. Four children treated with cyclosporin A (CSP) achieved rapid and complete recovery, but one patient without CSP died due to rapidly progressive respiratory failure. All children treated with CSP responded quickly, and fever abated within 36 h of initiation of treatment. CSP should be added to first-line therapy of MAS.Acta Haematologica 02/2005; 113(2):124-9. · 1.35 Impact Factor -
Article: Multicenter comparison of rapid lateral flow stool antigen immunoassay and stool antigen enzyme immunoassay for the diagnosis of Helicobacter pylori infection in children.
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ABSTRACT: The stool antigen enzyme immunoassay (EIA) methods are widely used for diagnosing Helicobacter pylori infection. Recently, a novel, rapid stool antigen test, the lateral flow immunoassay (LFI) method, has been developed. The primary purpose of this study was to compare the EIA method with the LFI method for the diagnosis of H. pylori infection in children. Stool specimens from children being evaluated for H. pylori infection were also examined using the LFI (ImmunoCard STAT! HpSA) and EIA methods (Premier Platinum HpSA). The sensitivity, specificity and accuracy of the test were based on the 13C-labeled urea breath test. One hundred and eighty-two children and adolescents, 3-17 years of age (mean 9.2 years), were studied. In addition, 29 patients who received eradication therapy were re-evaluated 2 or 3 months post-treatment. The 13C-labeled urea breath test was positive in 64 patients (35.2%). The sensitivity, specificity and accuracy of the LFI method were 90.6% (95% CI = 80.7-96.5%), 95.8% (92.1-99.4%), and 94.0% (90.5-97.4%), respectively and for the EIA method, sensitivity, specificity and accuracy were 96.8% (95% CI, 89.0-99.6%) and 99.2% (97.5-100%), and 98.3% (96.5-100%), respectively. There were no significant differences in results among the age groups 3-5, 6-10 and 11-17 years. As for the assessment of H. pylori eradication, the results of the LFI and EIA methods agreed with those of 13C-urea breath test in 27/29 and 29/29 patients, respectively. The LFI stool antigen method showed a good sensitivity, specificity and accuracy for diagnosing H. pylori infection in children. This novel method may be useful in clinical practice as an office-based test because it is rapid, reliable and easy to perform.Helicobacter 01/2005; 9(6):669-73. · 3.15 Impact Factor -
Article: Helicobacter pylori infection in childhood.
Journal of Gastroenterology 09/2004; 39(8):809-10. · 4.16 Impact Factor -
Article: Cerebrospinal fluid cytokines in Salmonella urbana encephalopathy.
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ABSTRACT: We present a case report of encephalopathy associated with Salmonella urbana infection in a child. A 5-year-old boy was admitted to our clinic with convulsions and coma. Cerebrospinal fluid (CSF) interleukin-6 (IL-6) and IL-8 were elevated at onset and were decreased within normal limit on the fifth day. Residual neurological deficits included severe mental deficits and spastic tetraplegia. High levels of CSF proinflammatory cytokines might be related to central nervous system (CNS) disease activity. Although encephalopathy is a rare complication of non-typhi Salmonella infection, it should be borne in mind as an occasionally serious and potentially lethal disease.The Tohoku Journal of Experimental Medicine 07/2004; 203(2):129-32. · 1.24 Impact Factor -
Article: Helicobacter pylori infection and idiopathic epilepsy.
The American Journal of Medicine 03/2004; 116(3):209-10. · 5.43 Impact Factor -
Article: Evaluation of a urine antibody test for Helicobacter pylori in Japanese children.
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ABSTRACT: To evaluate the accuracy of a urine-based enzyme-linked immunosorbent assay (ELISA) kit for anti-Helicobacter pylori immunoglobulin G antibody (urine-HpELISA) in children, we compared its sensitivity and specificity in reference to (13)C-urea-breath test (UBT) and H pylori stool antigen test (HpSA). Japanese children without significant upper abdominal symptoms were included (n=100; mean age, 7.0 years; range, 2 to 15). UBT, HpSA, and urine-HpELISA were performed. Of 100 children, 36 and 64 were judged H pylori-positive and H pylori-negative, respectively, by UBT and HpSA. Thirty-four of 36 positive children were positive by urine-HpELISA, and 62 out of 64 negative children were negative by urine-HpELISA. Thus, the urine-HpELISA had 94.4% sensitivity and 96.9% specificity, with accuracy of 96.0%. The urine-HpELISA is a rapid, inexpensive, reliable, and easy-to-perform method for the diagnosis of H pylori infection in children. It may be useful not only for diagnosis but also for mass screening for epidemiological studies in pediatric population.Journal of Pediatrics 03/2004; 144(2):196-9. · 4.11 Impact Factor -
Article: Helicobacter pylori and TT virus prevalence in Japanese children.
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ABSTRACT: The major transmission route of Helicobacter pylori, oral-oral or fecal-oral, remains to be established. TT virus (TTV), a recently discovered microbe that is prevalent in healthy persons, is believed to be mainly transmitted by nonparenteral routes. The purpose of this study was to test the hypothesis that these two microorganisms have a common mode of transmission. We investigated the seroprevalence of H. pylori and TTV in a cross-sectional study of 454 healthy Japanese children from birth to age 15 years, living in five different geographic areas. Determination of H. pylori status was based on the presence of specific serum IgG and IgA antibodies, determined using enzyme immunoassays. TTV DNA was detected and the titer was determined using semiquantitative polymerase chain reaction with heminested primers. The overall prevalences of H. pylori and TTV were 12.2% and 21.6%, respectively. An age-related increase of prevalence was shown for H. pylori ( P < 0.001), but not for TTV ( P = 0.23). Titers of TTV DNA significantly decreased with age (P = 0.02). There were significant geographic differences in TTV prevalence ( P < 0.001), but not in H. pylori seroprevalence (P = 0.33). There was no true correlation between the prevalence of these two organisms (Phi coefficient = -0.02 and P = 0.66). Although Japanese children frequently acquire both H. pylori and TTV, especially in early childhood, their acquisition appears to be independent.Journal of Gastroenterology 02/2003; 38(12):1126-30. · 4.16 Impact Factor
Top co-authors
Top Journals
Institutions
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2013
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Hyogo College of Medicine
Nishinomiya, Hyogo-ken, Japan
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2012
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University of Toyama
- Graduate School of Medicine and Pharmaceutical Science for Education
Toyama-shi, Toyama-ken, Japan
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2007–2009
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Ministry of Health, Labour and Welfare - Japan
Tokyo, Tokyo-to, Japan
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2005
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Wakayama University
- Department of Pediatrics
Wakayama-shi, Wakayama-ken, Japan
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2004
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Wakayama Medical College
- Department of Pediatrics
Wakayama-shi, Wakayama-ken, Japan
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