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Dive into the research topics where Amir H. Sabouri is active.

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Featured researches published by Amir H. Sabouri.


American Journal of Medical Genetics | 2006

Association of AKT1 haplotype with the risk of schizophrenia in Iranian population.

Sepideh N. Bajestan; Amir H. Sabouri; Masayuki Nakamura; Hiroshi Takashima; Mohammad R. Keikhaee; Fatemeh Behdani; Mohammad R. Fayyazi; Mohammad R. Sargolzaee; Mahboobeh N. Bajestan; Zahra Sabouri; Esmaeil Khayami; Sima Haghighi; Susan Bany Hashemi; Nobutaka Eiraku; Hamid Tufani; Hossein Najmabadi; Kimiyoshi Arimura; Akira Sano; Mitsuhiro Osame

AKT‐glycogen synthase kinase 3β (GSK3β) signaling is a target of lithium and has been implicated in the pathogenesis of mood disorders and schizophrenia. AKT1 protein level is decreased in the peripheral lymphocytes and brains of schizophrenic patients. The SNP2/3/4 TCG haplotype of AKT1 was associated with schizophrenia in patients with Northern European origin. In the present study, we genotyped five single nucleotide polymorphisms (SNP1–5) of AKT1 gene according to the original study in Iranians comprising of 321 schizophrenic patients and 383 controls, all residing in Mashhad city, Northeastern Iran. Haplotype analysis showed that the frequency of a five‐SNP haplotype (AGCAG) was significantly higher in schizophrenic patients (0.068) than that of controls (0.034) (P = 0.03 after Bonferroni correction, OR = 2.04, CI = 1.2–3.4). In stratified analysis by schizophrenia subtypes, the frequency of the same haplotype was significantly higher in disorganized subtype (n = 78, frequency of haplotype=0.081) when compared with normal controls (P = 0.04 after Bonferroni correction, OR = 2.59, CI = 1.3–5.2). Our findings did not confirm the association of AKT1 SNP2/3/4 TCG haplotype with the risk of schizophrenia as reported in the original study but showed the evidence of association with a different haplotype, AKT1 five‐SNP AGCAG haplotype, with the risk of schizophrenia in Iranian population.


Blood | 2008

Impaired function of human T-lymphotropic virus type 1 (HTLV-1)–specific CD8+ T cells in HTLV-1–associated neurologic disease

Amir H. Sabouri; Koichiro Usuku; Daisuke Hayashi; Shuji Izumo; Yoshiro Ohara; Mitsuhiro Osame; Mineki Saito

Despite abundant activated virus-specific cytotoxic T lymphocytes (CTLs), patients with human T-lymphotropic virus type 1 (HTLV-1)-associated myelopathy/tropical spastic paraparesis (HAM/TSP) showed a significantly higher frequency of infected T cells than did healthy virus carriers (HVCs). Here, we demonstrate that at a given proviral load, the frequency of CD8(+) T cells that are negative for specific costimulatory molecules was significantly higher in HAM/TSP than in age-matched HVCs and uninfected healthy controls (HCs), whereas the frequency of intracellular perforin-positive CD8(+) T cells was significantly lower in both HAM/TSP and HVCs than in HCs. An inverse correlation between HTLV-1 proviral load (PVL) and percent perforin-positive CD8(+) T cells were observed only in disease-protective allele HLA-A*02-positive HVCs, but not in HAM/TSP patients, whether HLA-A*02 positive or negative, nor in HLA-A*02-negative HVCs. Significantly lower perforin expression was observed in HTLV-1-specific than in cytomegalovirus-specific CD8(+) T cells. Majority of HTLV-1-specific CD8(+) T cells in HVCs showed a CD28(-)CD27(+) phenotype, whereas HAM/TSP showed a CD28(-)CD27(-) phenotype. HTLV-1-specific CD8(+) T cells from HAM/TSP patients showed significantly lower degranulation than HVCs by CD107a mobilization assay. These findings suggest that an impaired function of HTLV-1-specific CTLs is associated with failing antiviral control and disease HAM/TSP.


The Journal of Infectious Diseases | 2004

Polymorphism in the Interleukin-10 Promoter Affects Both Provirus Load and the Risk of Human T Lymphotropic Virus Type I-Associated Myelopathy/Tropical Spastic Paraparesis

Amir H. Sabouri; Mineki Saito; Alun L. Lloyd; Alison M. Vine; Aviva W. Witkover; Yoshitaka Furukawa; Shuji Izumo; Kimiyoshi Arimura; Sara E. Marshall; Koichiro Usuku; Charles R. M. Bangham; Mitsuhiro Osame

To investigate non-human leukocyte antigen candidate genes that influence the outcome of human T cell lymphotropic virus (HTLV) type I infection, we analyzed 6 single-nucleotide polymorphisms in the interleukin (IL)-10 promoter region in 280 patients with HTLV-I-associated myelopathy/tropical spastic paraparesis (HAM/TSP) and 255 HTLV-I-seropositive asymptomatic carriers from an area where HTLV-I is endemic. The IL-10 -592 A allele, which shows lower HTLV-I Tax-induced transcriptional activity than the C allele in the Jurkat T cell line, was associated with a >2-fold reduction in the odds of developing HAM/TSP (P=.011; odds ratio [OR], 0.50 [95% confidence interval, 0.30-0.86]) by reducing the provirus load in the whole cohort (P=.009, analysis of variance). Given the OR and the observed frequency of IL-10 -592 A, we demonstrate that this allele prevents approximately 44.7% (standard deviation, +/-13.1%) of potential cases of HAM/TSP, which indicates that it defines one component of the genetic susceptibility to HAM/TSP in the cohort.


Journal of Neuroimmunology | 2004

Longer dinucleotide repeat polymorphism in matrix metalloproteinase-9 (MMP-9) gene promoter which correlates with higher HTLV-I Tax mediated transcriptional activity influences the risk of HTLV-I associated myelopathy/tropical spastic paraparesis (HAM/TSP)

Daisuke Kodama; Mineki Saito; Wataru Matsumoto; Amir H. Sabouri; Shuji Izumo; Kimiyoshi Arimura; Koichiro Usuku; Charles R. M. Bangham; Mitsuhiro Osame

Matrix metalloproteinase-9 (MMP-9) has been reported to be expressed in various inflammatory disorders including human T cell lymphotropic virus type I (HTLV-I) associated myelopathy/tropical spastic paraparesis (HAM/TSP). HTLV-I-infected T-cells expressed high levels of MMP-9 via viral transactivator Tax mediated activation of the MMP-9 promoter. To investigate whether the d(CA) repeat polymorphism in MMP-9 promoter affects the risk of developing HAM/TSP, we compared the allele frequencies between 200 HAM/TSP patients and 200 HTLV-I seropositive asymptomatic carriers (HCs). The longer d(CA) repeat alleles of MMP-9 promoter, which was associated with higher Tax-mediated transcriptional activity, was more frequently observed in HAM/TSP patients than HCs (p<0.01 by Mann-Whitney U-test). The length alteration of this d(CA) repeat in the MMP-9 promoter may cause phenotypic differences among HTLV-I infected infiltrating cells and may thereby be in part responsible for the development of HAM/TSP.


European Journal of Epidemiology | 2003

High seroprotection rate induced by intradermal administration of a recombinant hepatitis B vaccine in young healthy adults: Comparison with standard intramuscular vaccination

Mohammad J. Ghabouli; Amir H. Sabouri; Naser Shoeibi; Sepideh N. Bajestan; H. Baradaran

Intradermal (ID) vaccination has been proposed as a cost-saving alternative for administration of Hepatitis B (HB) vaccine to implement of mass vaccination of high-risk groups, particularly in developing countries. Therefore, the effectiveness of ID vaccination needs to be evaluated and verified in different ethnic backgrounds. The present study is a randomized trail using a recombinant vaccine (Heberbiovac) to compare immunogenecity and safety of an intradermal low-dose (4 μg) with standard dose (20 μg) of intramuscular (IM) vaccination in healthy Iranian population. Participants were 143 healthy Iranian medical and nursing students randomly allocated to ID or IM vaccination group. The vaccine was inoculated at 0, 1 and 6months intervals. Serum samples were collected 1month after the last vaccination and the anti-HBs response was determined using ELISA. The overall seroprotection rate (anti-HBs level ≥ 10IU/L) was 97.3% for ID vaccination group, which was not different from that of IM vaccination group (98.55%)(p= 0.99). Similarly, geometric mean titers (GMT) of anti-HBs were not significantly different between ID (1164.1IU/L) and IM (1071.8IU/L) vaccination groups (p= 0.4). There was no significant difference in seroprotection rate and GMT of anti-HBs between sexes. Although induration and hyperpigmentation at the site of injection were more frequently observed in ID vaccination group, no other clinically adverse effects were observed in both vaccination groups. We conclude that the ID route, which would require one-fifth of the standard dose, would be suitable for use in certain groups such as high-risk adults when the cost of vaccine is the inhibiting factor for mass vaccination.


Journal of the Neurological Sciences | 2005

ApaI polymorphism of vitamin D receptor gene is associated with susceptibility to HTLV-1-associated myelopathy/tropical spastic paraparesis in HTLV-1 infected individuals

Mineki Saito; Nobutaka Eiraku; Koichiro Usuku; Yasuyuki Nobuhara; Wataru Matsumoto; Daisuke Kodama; Amir H. Sabouri; Shuji Izumo; Kimiyoshi Arimura; Mitsuhiro Osame

HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP) is one outcome of human T-cell lymphotropic virus type-1 (HTLV-1) infection. It remains unknown why the majority of infected people remain healthy, whereas only approximately 2-3% of infected individuals develop the disease. The active form of vitamin D has immunomodulatory effects, and allelic variants of the vitamin D receptor (VDR) appear to be associated with differential susceptibility to several infectious diseases. To investigate whether VDR single nucleotide polymorphisms (SNPs) are associated with the development of HAM/TSP, we studied four VDR SNPs in a group of 207 HAM/TSP patients and 224 asymptomatic HTLV-1 seropositive carriers (HCs) in Kagoshima, Japan, by using PCR-RFLP analysis. We found that ApaI polymorphism of VDR is associated with the risk of HAM/TSP, although this polymorphism did not affect the provirus load of HTLV-1 in either HAM/TSP patients or HCs.


Journal of NeuroVirology | 2006

Clinical symptoms and the odds of human T-cell lymphotropic virus type 1–associated myelopathy/ tropical spastic paraparesis (HAM/TSP) in healthy virus carriers: Application of best-fit logistic regression equation based on host genotype, age, and provirus load

Hirohisa Nose; Mineki Saito; Koichiro Usuku; Amir H. Sabouri; Toshio Matsuzaki; Ryuji Kubota; Nobutaka Eiraku; Yoshitaka Furukawa; Shuji Izumo; Kimiyoshi Arimura; Mitsuhiro Osame

The authors have previously developed a logistic regression equation to predict the odds that a human T-cell lymphotropic virus type 1 (HTLV-1)-infected individual of specified genotype, age, and provirus load has HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP) in southern Japan. This study evaluated whether this equation is useful predictor for monitoring asymptomatic HTLV-1-seropositive carriers (HCs) in the same population. The authors genotyped 181 HCs for each HAM/TSP-associated gene (tumor necrosis factor [TNF]-α −863A/C, stromal cell-derived factor 1 (SDF-1) +801G/A, human leukocyte antigen [HLA]-A*02, HLA-Cw*08, HTLV-1 tax subgroup) and measured HTLV-1 provirus load in peripheral blood mononuclear cells using real-time polymerase chain reaction (PCR). Finally, the odds of HAM/TSP for each subject were calculated by using the equation and compared the results with clinical symptoms and laboratory findings. Although no clear difference was seen between the odds of HAM/TSP and either sex, family history of HAM/TSP or adult T-cell lenkemia (ATL), history of blood transfusion, it was found that brisk patellar deep tendon reflexes, which suggest latent central nervous system compromise, and flower cell-like abnormal lymphocytes, which is the morphological characteristic of ATL cells, were associated with a higher odds of HAM/TSP. The bestfit logistic regression equation may be useful for detecting subclinical abnormalities in HCs in southern Japan.


European Journal of Neurology | 2003

A C77G point mutation in CD45 exon 4, which is associated with the development of multiple sclerosis and increased susceptibility to HIV-1 infection, is undetectable in Japanese population

Amir H. Sabouri; Mineki Saito; Wataru Matsumoto; Daisuke Kodama; Reza Farid; S. Izumo; Koichiro Usuku; Mitsuhiro Osame

HTLV‐1 associated myelopathy/tropical spastic paraparesis (HAM/TSP) is one outcome of Human T‐cell lymphotropic virus type 1 (HTLV‐1) infection. It remains unknown why the majority of infected people remain healthy whereas only approximately 2–3% develop disease. Recently, heterozygous state of CD45 exon 4 mutation (C77C wild type and C77G mutant) was reported to be associated with development of multiple sclerosis in German patients and increased susceptibility to HIV‐1 infection in the United Kingdom. To investigate whether this mutation is associated with the development of HAM/TSP, we studied a group of 164 HAM/TSP patients and 108 asymptomatic HTLV‐1 carriers in Kagoshima (HTLV‐1 endemic area in Southern Japan) by using PCR‐RFLP and subsequent direct sequencing analysis. All 272 subjects showed homozygosity in the CD45 exon 4, suggesting that this mutation is absent or very rare in Japanese population.


Journal of the Neurological Sciences | 2004

Serum concentration and genetic polymorphism in the 5'-untraslated region of VEGF is not associated with susceptibility to HTLV-I associated myelopathy/tropical spastic paraparesis (HAM/TSP) in HTLV-I infected individuals.

Mineki Saito; Koichiro Usuku; Yasuyuki Nobuhara; Wataru Matsumoto; Daisuke Kodama; Amir H. Sabouri; Shuji Izumo; Kimiyoshi Arimura; Mitsuhiro Osame

HTLV-I- associated myelopathy/tropical spastic paraparesis (HAM/TSP) is one outcome of human T-cell lymphotropic virus type I (HTLV-I) infection. It remains unknown why the majority of infected people remain healthy whereas only approximately 2-3% of infected individuals develop the disease. Recently, it has been reported that increased plasma concentrations of VEGF were significantly related to high ATL cell infiltration, and the viral transactivator Tax activates the VEGF promoter, linking the induction of angiogenesis to viral gene expression. To investigate whether VEGF promoter -634C/G single nucleotide polymorphism (SNP) and serum concentration of VEGF are associated with the development of HAM/TSP, we studied a group of 202 HAM/TSP patients, 202 asymptomatic HTLV-I seropositive carriers (HCs) and 108 seronegative healthy controls (NCs) in Kagoshima, Japan by using PCR-RFLP analysis. The serum concentration of VEGF was also compared among patients with HAM/TSP, ATL, HCs as well as with NCs. Our results indicate that both VEGF gene polymorphism and serum VEGF levels are not specifically associated with the risk of HAM/TSP in our cohort.


Journal of the Neurological Sciences | 2006

Flow cytometry evaluation of the T-cell receptor Vβ repertoire among human T-cell lymphotropic virus type-1 (HTLV-1) infected individuals: Effect of interferon alpha therapy in HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP)

Mineki Saito; Hirohisa Nose; Koichiro Usuku; Amir H. Sabouri; Toshio Matsuzaki; Shuji Izumo; Kimiyoshi Arimura; Mitsuhiro Osame

Human T-cell lymphotropic virus type-1 (HTLV-1)-associated myelopathy/tropical spastic paraparesis (HAM/TSP) is chronic inflammatory disease of the spinal cord characterized by perivascular lymphocytic cuffing and parenchymal lymphocytic infiltration. In this study using flow cytometry, we have investigated the T-cell receptor (TCR) Vbeta repertoire of peripheral blood T lymphocytes in 8 HAM/TSP patients, 10 HTLV-1 infected healthy carriers, and 11 uninfected healthy controls to determine if there is a biased usage of TCR Vbeta. We found that TCR Vbeta7.2 was under-utilized and Vbeta12 was over-utilized in CD4+ T cells of HTLV-1 infected individuals compared with healthy uninfected controls, whereas there were no such differences in CD8+ T cells. Comparison of Vbeta repertoire changes before and after interferon-alpha (IFN-alpha) treatment for HAM/TSP revealed that one out of five patients showed dramatic decrease of specific Vbeta in CD8+ T cells. Our results suggest that dominant Vbeta subpopulations in CD4+ T cells evolved associated with chronic HTLV-1 infection, and IFN-alpha treatment for HAM/TSP does not induce a specific pattern of TCR Vbeta changes.

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