Researchers Database

KANAI Takahiro

    Pediatrics Associate Professor
Contact: tkanaijichi.ac.jp
Last Updated :2021/11/23

Researcher Information

URL

J-Global ID

Research Areas

  • Other / Other / Laboratory medicine

Academic & Professional Experience

  • 2013  Jichi Medical UniversitySchool of Medicine講師

Published Papers

  • Takahiro Kanai, Takanori Yamagata, Takane Ito, Jun Odaka, Takashi Saito, Jun Aoyagi, Mariko Y. Momoi
    CLINICAL AND EXPERIMENTAL NEPHROLOGY 19 (1) 107 - 113 1342-1751 2015/02 [Refereed][Not invited]
     
    Various humoral factors have been proposed as causal agents of idiopathic steroid-sensitive nephrotic syndrome (ISSNS), resulting in varying data. We used mass spectrometry (MS) to analyze serum proteins in a search for proteins that might be involved in ISSNS pathophysiology. Serial serum samples were obtained from 33 children with ISSNS. Samples were collected during Phase A1 [the acute phase prior to steroid treatment (STx)], Phase A2 (remission with STx), and Phase A3 (remission without any medication). We also included age- and sex-matched two control groups comprising children with normal urinalysis (Group B) and children with a nephrotic syndrome other than ISSNS (Group C). The urinary protein/urinary creatinine (UP/UCr) ratios were not statistically different between Phase A1 and Group C. Samples were analyzed using surface-enhanced laser desorption/ionization time of flight MS. A total of 207 peptide ion peaks were detected in the range of m/z 2000-10000. Four peptide ions (m/z 6444, 6626, 8695, and 8915) were detected at significant elevation during Phase A1 compared with Phase A2, Phase A3, and Group C. The intensities of m/z 6444 and 8695 were higher in Phase A3 than in Group B. There were significant correlations between the intensities of m/z 6626, 8695, and 8915 and UP/UCr levels. The m/z 8695 was identified as apolipoprotein AII. Apolipoprotein AII was detected as a protein associated with the UP/UCr levels in pediatric ISSNS. Our findings present an interesting starting point for further investigation into the pathophysiology of ISSNS.
  • Jun Odaka, Takahiro Kanai, Ritei Uehara, Eiji Kusano, Takanori Yamagata
    CLINICAL AND EXPERIMENTAL NEPHROLOGY 19 (1) 146 - 147 1342-1751 2015/02 [Refereed][Not invited]
  • Jun Aoyagi, Jun Odaka, Yuri Kuroiwa, Naomi Nakashima, Takane Ito, Takashi Saito, Takahiro Kanai, Takanori Yamagata, Mariko Y. Momoi
    PEDIATRICS INTERNATIONAL 56 (3) e4 - e6 1328-8067 2014/06 [Refereed][Not invited]
     
    It has been established that enhanced computed tomography (CT) and 99mTc-dimercaptosuccinic acid renal scintigraphy (99mTc-DMSA scintigraphy) used in conjunction with single-photon emission CT is a useful tool for the diagnosis of acute pyelonephritis (APN). The utility of non-enhanced magnetic resonance imaging (MRI), however, has not been investigated extensively for the diagnosis of APN or renal abscess in children. We describe the case of a 23-month-old boy with suspected APN who received non-enhanced MRI. Whole body diffusion-weighted imaging (DWI) was used, and a background body-signal suppression sequence was applied. High-intensity focal lesions were identified on DWI and low-intensity lesions on the apparent diffusion coefficient map in the acute phase. This case suggested that non-enhanced MRI could be a useful tool for the diagnosis of APN in children, because it can avoid the risks of not only radiation exposure but also nephrogenic systemic fibrosis associated with gadolinium-based contrast agents, especially in infants.
  • Takahiro Kanai, Scott Seki, Jennifer A. Jenks, Arunima Kohli, Trupti Kawli, Dorrelyn Patacsil Martin, Michael Snyder, Rosa Bacchetta, Kari C. Nadeau
    PLOS ONE 9 (1) e86790  1932-6203 2014/01 [Refereed][Not invited]
     
    Signal transducer and activator of transcription (STAT) comprises a family of universal transcription factors that help cells sense and respond to environmental signals. STAT5 refers to two highly related proteins, STAT5A and STAT5B, with critical function: their complete deficiency is lethal in mice; in humans, STAT5B deficiency alone leads to endocrine and immunological problems, while STAT5A deficiency has not been reported. STAT5A and STAT5B show peptide sequence similarities greater than 90%, but subtle structural differences suggest possible non-redundant roles in gene regulation. However, these roles remain unclear in humans. We applied chromatin immunoprecipitation followed by DNA sequencing using human CD4(+) T cells to detect candidate genes regulated by STAT5A and/or STAT5B, and quantitative-PCR in STAT5A or STAT5B knock-down (KD) human CD4(+) T cells to validate the findings. Our data show STAT5A and STAT5B play redundant roles in cell proliferation and apoptosis via SGK1 interaction. Interestingly, we found a novel, unique role for STAT5A in binding to genes involved in neural development and function (NDRG1, DNAJC6, and SSH2), while STAT5B appears to play a distinct role in T cell development and function via DOCK8, SNX9, FOXP3 and IL2RA binding. Our results also suggest that one or more co-activators for STAT5A and/or STAT5B may play important roles in establishing different binding abilities and gene regulation behaviors. The new identification of these genes regulated by STAT5A and/or STAT5B has major implications for understanding the pathophysiology of cancer progression, neural disorders, and immune abnormalities.
  • Jenks JA, Seki S, Kanai T, Huang J, Morgan AA, Scalco RC, Nath R, Bucayu R, Wit JM, Al-Herz W, Ramadan D, Jorge AA, Bacchetta R, Hwa V, Rosenfeld R, Nadeau KC
    Clinical immunology (Orlando, Fla.) 2 148 227 - 236 1521-6616 2013/08 [Refereed][Not invited]
  • Takahiro Kanai, Hirohiko Shiraishi, Ritei Uehara, Takane Ito, Mariko Y. Momoi
    PEDIATRIC CARDIOLOGY 8 33 (8) 1343 - 1347 0172-0643 2012/12 [Refereed][Not invited]
     
    Various agents have been suggested as causal or associated factors in the pathogenesis of Kawasaki disease (KD); however, the underlying factors of KD remain unknown. Plasma exchange is one of the most effective treatments for the acute phase of KD. This indicates that plasma may contain factors associated with the pathogenesis of KD. To search for proteins that may be involved in KD pathogenesis, we analyzed serum proteins with surface-enhanced laser desorption/ionization time of flight mass spectrometry (SELDI-TOF MS). Serum samples were obtained from 17 KD patients. Serum from six of the patients was collected during acute phase before acetylsalicylic acid (ASA) and intravenous immunoglobulin administration (phase A1), during remission with ASA (phase A2), and during remission without any medication (phase A3). Serum from the remaining 11 patients was collected for phases A1 and A2 only. There were two age- and sex-matched control groups comprising 8 afebrile healthy children (group B) and 8 febrile children with several infectious diseases (group C). There were no statistical differences in laboratory examination between phase A1 and group C except for albumin level, alanine aminotransferase, or sodium level. Serum samples were analyzed by SELDI-TOF MS after purification. We detected five peaks, i.e., those were specifically increased or decreased during phase A1, and identified 1 of these as alpha 1-antitrypsin (alpha 1-AT). alpha 1-AT can inhibit neutrophil elastase activity. This elastase is thought to play a role in coronary artery damage. Our findings present an interesting starting point for further investigations into the pathophysiology of KD.
  • Takahiro Kanai, Jennifer Jenks, Kari Christine Nadeau
    FRONTIERS IN IMMUNOLOGY 3 234  1664-3224 2012 [Refereed][Not invited]
     
    The signal transducer and activator of transcription (STAT) 5b is a universal transcription factor that plays key biological roles in allergic diseases, immunodeficiencies, autoimmunities, cancers, hematological diseases, growth disorders, and lung diseases. The identification of distinct pathological manifestations of STAT5b deficiency in humans has highlighted the critical role of the STAT5b pathway. Proper gene transcription at IL-2R alpha, FOXP3, Bcl-2, and growth hormone (GH) associated loci are thought to be associated with normal STAT5b transcriptional activity.These genes are thought to play important roles in allergy/autoimmunity, immunodeficiency, cancer/anemia, and growth, respectively. The STAT5A and STAT5B genes are collocated on 17q11. Although these two monomeric proteins exhibit peptide sequence similarities of >90%, it is known through observations of STAT5b deficient subjects that STAT5a and STAT5b are not fully redundant in humans. Patients with STAT5b deficiency have decreased numbers of regulatory CD4(+)CD25(high) T cell (Treg) despite their STAT5a levels being normal. Prior studies on STAT5b deficient subjects have revealed immunological aberrations associated with the following disease phenotype: modest lymphopenia and decreased populations of Treg, gamma-delta Tcells, and natural killer INK) cells. Most subjects with STAT5b deficiency show severe eczema, and autoimmune disease (juvenile idiopathic arthritis, autoimmune thyroiditis, idiopathic thrombocytic purpura) which are thought to be associated with Treg dysfunction. We will review the likely pathophysiological mechanisms associated with STAT5b deficiency.
  • Takahiro Kanai, Hirohiko Shiraishi, Takanori Yamagata, Takane Ito, Jun Odaka, Takashi Saito, Jun Aoyagi, Mariko Y. Momoi
    PEDIATRICS INTERNATIONAL 53 (6) 906 - 909 1328-8067 2011/12 [Refereed][Not invited]
     
    Background: Several cytokines have a pathological association with idiopathic steroid-sensitive nephrotic syndrome (ISSNS) in inducing proteinuria or regulating T cells. Because interleukin (IL)-7 plays important roles in regulating T-cell proliferation and sustaining naive or memory T cells, IL-7 is one of the candidate cytokines in the pathogenesis of ISSNS. Very little is known, however, about the association of IL-7 with ISSNS. To clarify the IL-7 dynamics in children with ISSNS, serum IL-7 level was investigated, from the nephrotic phase before steroid treatment (STx; group A1) to the remission phase with STx (group A2) and without STx (group A3). Methods: Eighteen children with ISSNS were included in the present study. A total of 25 paired samples were analyzed for groups A1 and A2, and a total of 10 paired samples for groups A1, A2, and A3 due to recurrence. Two control groups ( with normal urinalysis, group B; or with nephrotic syndrome other than ISSNS, group C), matched for age and gender, were also included. Serum cytokine level was measured on bead-based assay. Results: Each serum IL-7 level in groups A1 and A3 was higher than each serum IL-7 level of groups C and B, respectively. The group A2 serum IL-7 level was higher than that of group A1. There was no statistical significance of serum IL-7 level between group A1 and group A3. Conclusion: Serum IL-7 level was elevated in children with ISSNS regardless of the status of the disease. This brings us one step closer to a better understanding of the pathophysiology of ISSNS in children.
  • Kanai T, Yamagata T, Ito T, Odaka J, Saito T, Aoyagi J, Kobayashi M, Ohashi T, Ueda Y, Momoi MY
    JIMD reports 1 39 - 42 2192-8304 2011 [Refereed][Not invited]
  • Takahiro Kanai, Hirohiko Shiraishi, Takanori Yamagata, Takane Ito, Jun Odaka, Takashi Saito, Jun Aoyagi, Mariko Y. Momoi
    CLINICAL AND EXPERIMENTAL NEPHROLOGY 14 (6) 578 - 583 1342-1751 2010/12 [Refereed][Not invited]
     
    Various studies reported a higher incidence of allergic disorders, with an overreactivity of type 2 helper T-cell (Th2) immune mechanisms, in children with idiopathic steroid-sensitive nephrotic syndrome (ISSNS). However, Th2 predominance in ISSNS has not been definitively identified. To determine whether Th2 was predominant in children with ISSNS, we used paired samples to measure the type 1 helper T-cell (Th1)/Th2 ratios and serum cytokine levels secreted by Th1 and Th2. We measured the Th1/Th2 ratios and levels of Th1- or Th2-secreted cytokines in paired samples. Fourteen children met the inclusion criteria: (1) ISSNS; (2) selectivity index < 0.1; (3) sera obtained in at least two disease phases; (4) no infection; (5) no immunosuppressants. Two control groups (group B, normal urinalysis; group C, nephrotic syndrome other than ISSNS) were included for cytokine level comparisons. Th1 and Th2 numbers were counted by three-color flow cytometry. Cytokine levels were measured by bead-based assay. The Th1/Th2 ratio was lower in group A-1 [nephrotic-phase before steroid treatment (STx)] than in groups A-2 (remission-phase with STx) and A-3 (remission-phase without STx). Th2-secreted interleukin-5 (IL-5) levels were higher in group A-1 than in groups A-2 and A-3. There were no differences in IL-5 levels between groups A-1 and C and between groups A-3 and B. Our results suggest that Th2 played a predominant role both in the Th1/Th2 ratio and in the serum IL-5 level in children with ISSNS in the nephrotic phase.
  • Takahiro Kanai, Hirohiko Shiraishi, Takane Ito, Jun Odaka, Takashi Saito, June Aoyagi, Yoshihiko Ueda, Mariko Y. Momoi
    THERAPEUTIC APHERESIS AND DIALYSIS 14 (6) 603 - 605 1744-9979 2010/12 [Refereed][Not invited]
  • Tetsuya Yanagida, Hiroyuki Matsuoka, Takahiro Kanai, Minoru Nakao, Akira Ito
    PARASITOLOGY INTERNATIONAL 59 (2) 268 - 270 1383-5769 2010/06 [Refereed][Not invited]
     
    An anomalous tapeworm with abnormal segmentation was obtained from a 6-year-old boy in Japan. The tapeworm consisted of proglottids with slanted anterior and posterior margins of proglottids and 4-6 sets of reproductive organs arranged between the margins. The morphology of the tapeworm did not correspond to any of the described cestodes. However, molecular identification based on nuclear and mitochondrial genes clearly showed the tapeworm was Diphyllobothrium nihonkaiense. (c) 2009 Elsevier Ireland Ltd. All rights reserved.
  • Takahiro Kanai, Shigeru Yotsumoto, Mariko Y. Momoi
    PEDIATRICS INTERNATIONAL 52 (1) E23 - E25 1328-8067 2010/02 [Refereed][Not invited]
  • Takahiro Kanai, Takanori Yamagata, Mariko Y. Momoi
    PEDIATRICS INTERNATIONAL 51 (4) 443 - 447 1328-8067 2009/08 [Refereed][Not invited]
     
    Background: The cytokines associated with idiopathic steroid-sensitive nephrotic syndrome (ISSNS) have not been identified definitively, because previous studies had variable sampling and population heterogeneity. To clarify the cytokines involved, serum cytokine levels were measured using uniform sampling in a homogeneous population. Methods: Five children meeting the following criteria were included: (i) ISSNS; (ii) selectivity index < 0.1; (iii) paired sera obtained in the nephrotic phase before steroid treatment (STx; group A) and in the remission phase under STx (group B); (iv) no infection; and (v) no immunosuppressant. Control groups were as follows: group C, four children with ISSNS in the remission phase without STx; group D, five with normal urinalysis; group E, five with symptomatic secondary nephrotic syndrome before STx. Cytokine levels were measured using bead-based assay. Results: Serum macrophage inflammatory protein-1 beta (MIP-1 beta) levels were higher in group B compared to group A, and group C was lower than groups A and B. Serum interleukin-8 (IL-8) levels were higher in group A than in groups B and C, and groups B and C did not differ. With regard to both cytokine levels, there were no differences between groups C and D, and groups A and E. Conclusion: Serum MIP-1 beta and IL-8 are associated with the clinical status of ISSNS in children. A relationship between MIP-1 beta and ISSNS has not been previously reported. The mechanism by which MIP-1 beta and IL-8 affect ISSNS is unclear. Nevertheless, the present findings are an interesting starting point for further investigations into the pathophysiology of ISSNS in children.

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