Hitoshi Tajiri

Diagnostic accuracy of the 13C-urea breath test for childhood Helicobacter pylori infection: a multicenter Japanese study

OBJECTIVES:In adults, the 13C-urea breath test (UBT) has been widely used as a noninvasive test of Helicobacter pylori infection because of its high sensitivity and specificity. However, this test is less well established in pediatric practice. The optimum cutoff value and test protocol of the 13C-UBT remains to be established in the pediatric population. The primary purpose of this study was to evaluate diagnostic accuracy of the 13C-UBT for children and to determine its optimum cutoff value.METHODS:A total of 220 Japanese children aged 2–16 yr (mean = 11.9) who underwent upper GI endoscopy and gastric biopsies were finally studied. Endoscopic diagnoses included gastritis (n = 131), gastric ulcer (n = 15), duodenal ulcer (n = 72), and combined ulcer (n = 2). H. pylori infection status was confirmed by biopsy tests including histology, urease test, and culture. With the 13C-UBT, breath samples were obtained at baseline and at 20 min after ingestion of 13C-urea without a test meal and were analyzed by isotope ratio mass spectrometry. Based on biopsy tests, a cutoff value was determined using a receiver operating characteristic curve. In 26 children (seven children infected and 19 noninfected), paired breath samples were also measured by nondispersive infrared spectometry (NDIRS).RESULTS:Biopsy tests demonstrated that 89 children (40%) were infected with H. pylori and 131 children were not infected. There were no statistical differences in mean Δ 13C values at 20 min between male and female H. pylori-infected and noninfected patients. A receiver operating characteristic analysis defined the best cutoff value as 3.5‰. The overall sensitivity and specificity at a cutoff value of 3.5‰ were 97.8% (95% CI = 92.1–99.7%) and 98.5% (95% CI = 96.4–100%), respectively: high sensitivity and specificity were demonstrated in all three age groups (≤5, 6–10, and ≥11 yr). There was a close correlation between the values with isotope ratio mass spectrometry and NDIRS methods (r = 0.998, p < 0.001).CONCLUSIONS:The 13C-UBT with a cutoff value of 3.5‰ is an accurate diagnostic method for active H. pylori infection. The test with the NDIRS method is inexpensive and might be widely applied in clinical practice.

Manganese Deposition in the Brain During Long-Term Total Parenteral Nutrition

BACKGROUND Manganese deposition was suspected in a pediatric patient who received long-term total parenteral nutrition. T1-weighted magnetic resonance images revealed high intensity areas in the globus pallidus. This study was designed to clarify if these abnormal findings were related to manganese deposition and clinical neurological manifestations. METHODS Whole-blood manganese concentrations were measured during manganese supplementation to total parenteral nutrition and after 5 months without manganese. Magnetic resonance images were also examined on each occasion and compared with the blood level of manganese. RESULTS The whole-blood manganese level during supplementation was 135 micrograms/L (normal range 14.6 +/- 4.7 micrograms/L), whereas the level was 20 micrograms/L after a manganese-free period of 5 months. Accompanied with normalization of manganese level, abnormal high intensity lesions in the globus pallidus on T1-weighted images also disappeared. No neurological manifestation related to the high manganese level was recognized. CONCLUSIONS It is probable that the high manganese level was elicited by manganese supplementation to total parenteral nutrition. This high manganese condition was confirmed by the measurement of whole-blood manganese level, which was associated with the abnormal high intensity lesions on T1-weighted magnetic resonance images.

The prevalence of Helicobacter pylori in Japanese children with gastritis or peptic ulcer disease

BackgroundAlthough Helicobacter pylori infection is typically acquired in childhood, the role of H. pylori infection in gastroduodenal diseases in childhood remains to be defined. The purpose of this study was to evaluate the prevalence of H. pylori infection in children with gastritis, duodenal ulcer, and gastric ulcer.MethodsThis was a retrospective analysis of 283 Japanese children (mean age, 11.5 years) with non-nodular gastritis (n = 73), nodular gastritis (n = 67), duodenal ulcer (n = 100), and gastric ulcer (n = 43). H. pylori status was based on biopsy tests. Clinical symptoms at the time of endoscopy were analyzed with regard to a possible association with the infection.ResultsThe prevalence of H. pylori in non-nodular gastritis, nodular gastritis, duodenal ulcer, and gastric ulcer was 28.8%, 98.5%, 83.0%, and 44.2%, respectively. H. pylori was significantly linked to duodenal ulcer and gastric ulcers in the age group of 10–16 years, but not in the age group of 9 years and under. In children with H. pylori infection, nodular gastritis was observed in 26.3% of gastric ulcer patients and in 74.7% of duodenal ulcer patients (P < 0.001). H. pylori infection was significantly associated with the prevalence of anemia (P < 0.05).ConclusionsH. pylori is the most important causal factor for the development of duodenal ulcer in childhood. While H. pylori infection appears to be a risk factor in gastric ulcer, other causes are responsible for most cases. Nodular gastritis is the most common type of H. pylori gastritis in childhood. Chronic infection with H. pylori is associated with anemia.

Chronic hepatitis in an infant, in association with human herpesvirus-6 infection

A 20-month-old boy was investigated for persistent liver dysfunction. Liver histologic findings showed chronic hepatitis. The presence of human herpesvirus-6 DNA in liver tissue was demonstrated both by in situ hybridization and by polymerase chain reaction. Human herpesvirus-6 may be a causative agent of chronic hepatitis in this case.

Cytokine and chemokine response in children with the 2009 pandemic influenza A (H1N1) virus infection

We report the systemic cytokine and chemokine response in children with the 2009 pandemic influenza A (H1N1) virus infection. In patients with pneumonia, the serum levels of IFN-γ and IL-5 were significantly higher than those in patients without pneumonia. This tendency was also present for IL-6, IL-8, IL-10, IL-13, and MCP-1 in patients with pneumonia. Among patients with pneumonia, the levels of MCP-1 were significantly higher in the group of patients with pneumonia with severe respiratory failure than patients with mild pneumonia.

Comparison between the 13C-urea breath test and stool antigen test for the diagnosis of childhood Helicobacter pylori infection.

BackgroundAs noninvasive tests for Helicobacter pylori infection, the 13C-urea breath test (UBT) and stool antigen test have been widely used. In children, however, there are few studies reporting which test shows superior performance. The purpose of this study was to compare the 13C-UBT and stool antigen test for their accuracy in diagnosing H. pylori infection in children.MethodsA total of 123 Japanese children, ages 2 to 17 years (mean, 12 years) who underwent gastric biopsies for H. pylori infection were studied. The diagnoses included gastritis (n = 55), gastric ulcer (n = 5), duodenal ulcer (n = 20), iron-deficiency anemia (n = 7), and other conditions (n = 36). The cutoff value of the 13C-UBT was defined to be 3.5‰. The stool antigen test was performed using the HpSA enzyme-linked immunosorbent assay (ELISA) (Premier Platinum HpSA). In 16 patients who received eradication therapy, the 13C-UBT and HpSA were repeated 2 months after treatment.ResultsBased on biopsy tests, 60 children were infected with H. pylori and 63 children were not. For the 13C-UBT, the sensitivity, specificity, and accuracy were 95.0% (95% confidence interval [CI], 86.1%–99.0%), 98.4% (95% CI, 91.5%–100%), and 96.4% (95% CI, 93.6%–99.9%), respectively. For the HpSA, the sensitivity, specificity, and accuracy were 98.3% (95% CI, 90.8%–100%), 98.4% (95% CI, 91.2%–100%), and 98.3% (95% CI, 96.0%–100%), respectively. There were no significant differences between the performance of these two tests. In the assessment of H. pylori eradication, the results of 13C-UBT and HpSA agreed with those of biopsy tests.ConclusionsThe 13C-UBT and the HpSA are equally accurate for the diagnosis of active H. pylori infection in Japanese children.

Results of triple eradication therapy in Japanese children: a retrospective multicenter study

BackgroundLarge-scale clinical trials in children are lacking concerning Helicobacter pylori eradication therapies. The purpose of this study was to assess the efficacy of proton pump inhibitor (PPI)-based triple therapies in Japanese children.MethodsThis was a retrospective analysis of the first- and second-line PPI-based triple therapies from pediatric gastrointestinal units between 1996 and 2003. Data collected included doses and duration of regimens, drug compliance, success or failure of eradication, ulcer healing, and symptom response of those with dyspepsia and no ulcers. The results of antibiotic susceptibility tests were also reported in cases where these were performed.ResultsA total of 149 pediatric patients (mean age, 12.6 years) were studied, including 123 patients who received first-line therapy: 115 received a PPI plus amoxicillin and clarithromycin (PAC) and 8 received a PPI plus amoxicillin and metronidazole (PAM). Overall eradication rates of the first-line PAC and PAM therapies were 77.4% and 87.5%, respectively (P = 0.68). All 14 patients with failed PAC therapy received the second-line PAM regimen, resulting in an eradication rate of 100%. Mild side effects were reported only in PAC regimens (13.8%). Primary resistance to amoxicillin, clarithromycin, and metronidazole was detected in 0%, 34.7%, and 12.5% of the strains, respectively. The PAC regimen showed a high eradication rate for clarithromycin-susceptible strains (91.7%), but was relatively ineffective for resistant strains (40.0%) (P < 0.01). Eradication of H. pylori was associated with ulcer healing and symptomatic improvement among those with gastritis only (both; P < 0.001). Among 17 patients with iron-deficiency anemia, post-treatment hemoglobin levels were higher than the pretreatment levels (P < 0.001).ConclusionsThe PAC regimen is effective in children. Clarithromycin resistance is associated with eradication failure. Metronidazole is a good substitute for clarithromycin as the second-line option for children.

Frequent Detection of the Human Herpesvirus 6-Specific Genomes in the Livers of Children with Various Liver Diseases

ABSTRACT This study was performed to investigate the frequency of human herpesvirus 6 (HHV-6) infection of the liver in children with a variety of liver diseases and to evaluate the role of HHV-6 infection in pediatric patients with prolonged non-B non-C hepatitis. Detection of the HHV-6 genomes in liver, in peripheral blood mononuclear cells (PBMC), and in plasma was performed by PCR or by in situ hybridization. Liver biopsy materials from 48 patients, in whom HHV-6 infection was serologically confirmed, were available for PCR analysis. Sequences of the HHV-6B genome were detectable in the livers of 36 of 48 patients (75%). The presence of the genome was not associated with serum transaminase activities. The genome was detectable in PBMC of 22 of 31 (71%) patients tested. In these 31 patients HHV-6 was detected in both the livers and PBMC of 20, was detected in PBMC but not in the livers of 2, was detected in the livers but not in PBMC of 3, and was detected in neither of samples of 6. In situ hybridization of the livers of six patients showed the presence of the HHV-6B genome in the nuclei of hepatocytes. The anti-HHV-6 immunoglobulin M antibody was detectable in 2 of 9 of the non-B non-C hepatitis patients, whereas none of the 22 patients with etiology-defined liver diseases tested positive. Cell-free viral DNA was not detectable in either group of patients. Our results showed that HHV-6B is frequently present in the livers of children with a variety of liver diseases but do not support the assumption that HHV-6B infection of the liver is associated with prolonged non-B non-C hepatitis.

Developmental regulation of Na+/myo-inositol cotransporter gene expression

Abstract myo -Inositol plays a role in many important aspects of cellular regulation including membrane structure, signal transduction and osmoregulation. It is taken up into the cells by the Na + / myo -inositol cotransporter (SMIT). We investigated developmental changes in the expression of SMIT mRNA and protein in the rat. In the fetal rat brain, SMIT mRNA was abundantly and diffusely expressed throughout the whole brain and the spinal cord. Positive signals were expressed in neuronal and non-neuronal cells in these regions. SMIT is gradually down-regulated nearer birth, but intense signals were still detected in the brain at postnatal day one. In the adult rat brain, very weak hybridization signals were detected throughout whole brain except for the choroid plexus where SMIT mRNA expression remained high. In contrast, the pattern of developmental regulation of SMIT gene expression in the kidney was opposite to that seen in the brain. Signals in the kidney were very weak during embryonic stages, whereas SMIT expression increased significantly after birth. These results suggest that myo -inositol and its transporter play an important role in the CNS developmental stage.

Favorable response to lymphoblastoid interferon-alpha in children with chronic hepatitis C.

BACKGROUND/AIMS We investigated the efficacy of interferon therapy for the treatment of children with chronic hepatitis C virus infection. METHODS Twenty-four out of 26 children completed the 6-month treatment with lymphoblastoid interferon-alpha and were followed for 12 months or longer. Response to interferon therapy was defined by assaying for circulating HCV-RNA, using a nested PCR, at 6-month intervals after the end of the therapy. RESULTS At the end of treatment circulating HCV-RNA was undetectable in 18/24 patients and at 6 months in 12/24. Ten of these 12 primary responders have remained virus free for more than 2 years. One patient remained negative at 12 months. The remaining patient relapsed at 12 months. At 24 months 10 of 18 patients tested negative for HCV-RNA. Serum alanine aminotransferase was normal in 11/24 patients at the end of treatment, at 6 months 12/24 were normal, and at 12 months 11/12 were normal. In eight children with sustained response, repeated liver biopsies revealed a reduction in Knodells scores for inflammation in the hepatic lobules and in the portal areas. In three of them neither plus nor minus strand of HCV-RNA was detectable in the liver tissue. Responders had a significantly lower level of viremia than non-responders. Side effects of interferon including fever, hair loss, neutropenia, and thrombocytopenia were not serious enough to warrant cessation of interferon treatment. CONCLUSIONS Interferon therapy in children with chronic hepatitis C may be beneficial as evaluated by sustained loss of viremia as well as by primary response.