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Hiroshi Wakiguchi

Publications and source records attributed to Hiroshi Wakiguchi.

At least 19 recordsLinked to original sources
PubMed2006

Effect of selenium-deficient diet on tubular epithelium in normal rats.

Selenium (Se) deficiency reduces glutathione peroxidase (GPx) activity, resulting in increased oxidative stress. We examined how Se deficiency induces renal injury via oxidative stress over time during the Se-deficient period. Seventy-two male Wistar rats were divided into two groups and fed either a control or Se-deficient diet. Rats were sacrificed on weeks 1, 2, 4, 6, 9, and 12. Blood and urine samples were collected, and the kidneys were removed. Urinalysis was performed, and creatinine clearance (Ccr) was calculated. Expressions of cellular GPx (cGPx) and phospholipid hydroperoxidase GPx (PHGPx) mRNA and GPx activity were measured. Histology was evaluated by light microscopy with immunohistochemistry for 4-hydroxy-2-nonenal (HNE) and vimentin. The Se-deficient diet caused significant decreases in GPx activity and cGPx mRNA expression but no change in PHGPx mRNA, together with significant proteinuria and glucosuria and slight decline in Ccr. The Se-deficient diet induced calcification in the kidney and increased the distribution of HNE and vimentin immunostaining in proximal tubuli, particularly around the outer medulla stripe. However, the histological damage did not progress after 6 weeks of deficiency. Se deficiency induces proteinuria and glucosuria with renal calcification, which may be primarily induced by injury of proximal tubuli via oxidative stress.

Animals↗
PubMed2006

Atrial fibrillation with hyperthyroidism in a 14-year-old male.

Atrial fibrillation is an uncommon feature of hyperthyroidism in childhood. We report a 14-year-old male who was referred to our hospital with hyperthyroidism and atrial fibrillation. He had a family history of atrial fibrillation. Spontaneous conversion of atrial fibrillation to sinus rhythm occurred 20 weeks after achieving euthyroid state by an antithyroid agent and a beta-blocker. Atrial fibrillation reoccurred after reduction of antithyroid medication and persisted for 19 weeks. Successful electrical cardioversion was performed resulting in conversion of heart rhythm to sinus. Usually, hyperthyroidism associated atrial fibrillation spontaneously reverts to sinus rhythm several weeks after achieving a euthyroid state. Control of thyroid function and heart rate is the goal of therapy for this type of atrial fibrillation.

Adolescent↗
PubMed2006

Effect of selenium on Cisplatin-induced nephrotoxicity in rats.

Cisplatin (CP), a commonly used antineoplastic drug, is nephrotoxic. CP-induced nephrotoxicity involves oxidative pathways. A deficiency of selenium (Se) reduces glutathione peroxidase (GPx) activity resulting in oxidative stress. We investigated how Se deficiency or oral Se administration influences CP-induced nephrotoxicity. Thirty male Wistar rats were fed a Se-deficient or control diet for 4 weeks. Then they were given intraperitoneal (i.p.) CP alone, i.p. saline alone, or Se by gavage 24 and 1 h prior to i.p. CP. Blood and urine samples were collected and the kidneys were removed 5 days after CP treatment. Urinalysis, renal function, GPx activity, and expression of cellular GPx mRNA were measured. Histology was evaluated by light microscopy with immunohistochemistry for 4-hydroxy-2-nonenal (HNE), vimentin, and heme oxygenase (HO)-1. CP induced renal tubular damage with increased expression of vimentin, HO-1 and HNE staining, which represents lipid peroxidation. Se deficiency exacerbated CP-induced nephrotoxicity as shown by deterioration of the above parameters and depressed GPx activity and expression of GPx mRNA. Se treatment ameliorated CP-induced nephrotoxicity, but did not significantly improve renal function. These findings suggest that Se deficiency increases oxidative stress and enhances CP-induced nephrotoxicity, whereas oral Se treatment partially protects against the nephrotoxicity in rats.

Administration, Oral↗
PubMed2006

CpG oligodeoxynucleotide prolongs eosinophil survival through activation of contaminating B cells and plasmacytoid dendritic cells in vitro.

BACKGROUND: In our previous study, oligodeoxynucleotides containing unmethylated CpG motifs (CpG ODNs) significantly prolonged eosinophil survival without inducing active release of eosinophil-derived neurotoxin or interleukin 8. In addition, this survival-promoting activity was nuclear factor-kappaB dependent. However, some eosinophil preparations from different donors hardly responded to CpG ODNs at all. To clarify why CpG ODN-induced nuclear factor-kB activation in eosinophils does not cause eosinophil-derived neurotoxin or interleukin 8 release and why the survival-promoting activity of CpG ODNs was not found in some eosinophil preparations, we determined the effect of extensive removal of contaminating B cells and plasmacytoid dendritic cells from human eosinophil preparations. METHODS: Eosinophils were purified from the peripheral blood of healthy or slightly allergic donors by gradient sedimentation and negative selection with anti-CD16 alone or a combination of anti-CD16, anti-CD19 and anti-blood dendritic cell antigen 4 (BDCA4) immunomagnetic beads. Eosinophil survival was measured with FITC-conjugated annexin V and propidium iodide by FACS after incubation with synthetic CpG 2006(CpG-B), CpG 2216 (CpG-A) or their GpC control ODNs for 24 h. RESULTS: The addition of anti-CD19 and anti-BDCA4 immunomagnetic beads reduced the number of contaminating CD19+ cells and CD123+ BDCA2+ cells in eosinophil preparations. CpG 2006 and CpG 2216, but not their GpC control ODNs, significantly prolonged survival of eosinophils purified with anti-CD16 immunomagnetic beads alone but not eosinophils purified with a combination of anti-CD16, anti-CD19 and anti-BDCA4 beads. CONCLUSIONS: These results strongly suggest that contaminating B cells or plasmacytoid dendritic cells in eosinophil preparations critically regulate CpG ODN-mediated prolongation of eosinophil survival and that CpG ODNs do not activate eosinophils directly.

Adjuvants, Immunologic↗
PubMed2006

Human tyrosine kinase 2 deficiency reveals its requisite roles in multiple cytokine signals involved in innate and acquired immunity.

Tyrosine kinase 2 (Tyk2) is a nonreceptor tyrosine kinase that belongs to the Janus kinase (Jak) family. Here we identified a homozygous Tyk2 mutation in a patient who had been clinically diagnosed with hyper-IgE syndrome. This patient showed unusual susceptibility to various microorganisms including virus, fungi, and mycobacteria and suffered from atopic dermatitis with elevated serum IgE. The patient's cells displayed defects in multiple cytokine signaling pathways including those for type I interferon (IFN), interleukin (IL)-6, IL-10, IL-12, and IL-23. The cytokine signals were successfully restored by transducing the intact Tyk2 gene. Thus, the Tyk2 deficiency is likely to account for the patient's complex clinical manifestations, including the phenotype of impaired T helper 1 (Th1) differentiation and accelerated Th2 differentiation. This study identifies human Tyk2 deficiency and demonstrates that Tyk2 plays obligatory roles in multiple cytokine signals involved in innate and acquired immunity of humans, which differs substantially from Tyk2 function in mice.

Adolescent↗
PubMed2005

Infantile eczema at one month of age is associated with cord blood eosinophilia and subsequent development of atopic dermatitis and wheezing illness until two years of age.

BACKGROUND: Physiological and pathological skin eruptions are commonly encountered in neonates in our clinical practice. However, the types of skin eruptions that are associated with the subsequent development of atopic dermatitis and the mechanisms of these associations remain uncertain. METHODS: A total of 105 newborn babies with normal delivery were enrolled in this prospective cohort study. The cord blood eosinophil count was measured and the neonates were examined at 1 month of age and followed until 8 years of age. RESULTS: At 1 month of age, infantile eczema, seborrheic dermatitis, intertrigo and diaper dermatitis were diagnosed in a total of 29, 7, 14 and 24 neonates, respectively. No association was found among the prevalences of these eruptions. Neonates with infantile eczema had a significantly higher number and ratio of eosinophils in the cord blood (eosinophil count: 670.8 +/- 67.8 vs. 349.0 +/- 30.3/microl, p < 0.0001; eosinophil ratio: 5.12 +/- 0.53 vs. 2.61 +/- 0.22%, p < 0.0001, for the presence and the absence of infantile eczema, respectively). In contrast, no such tendency was found for any other skin eruptions. In neonates with infantile eczema at 1 month of age, the diagnosis of atopic dermatitis had been made significantly earlier and the prevalence of wheezing illness was significantly higher than in those without infantile eczema until 2 years of age. CONCLUSION: Infantile eczema, but not other skin eruptions, precedes the development of atopic dermatitis and wheezing illness during early infancy, presumably because of the activation of eosinophils before birth.

Cohort Studies↗
PubMed2005

Brain phospholipase C/diacylglycerol lipase are involved in bombesin BB2 receptor-mediated activation of sympatho-adrenomedullary outflow in rats.

Bombesin receptors are mainly divided into two subtypes: BB1 receptor (neuromedin B-preferring receptor) and BB2 receptor [gastrin-releasing peptide (GRP)-preferring receptor]. Previously, we reported that intracerebroventricularly (i.c.v.) administered bombesin elevates plasma noradrenaline and adrenaline by production of brain arachidonic acid in rats. Arachidonic acid is released mainly by phospholipase A2 (PLA2)-dependent pathway or phospholipase C (PLC)/diacylglycerol lipase-dependent pathway. In the present study, bombesin and GRP elevated plasma catecholamines in a dose-dependent manner (1 and 5 nmol/animal, i.c.v.), while neuromedin B (1, 5 and 10 nmol/animal, i.c.v.) had no effect in urethane-anesthetized rats (bombesin=GRP>>neuromedin B). The bombesin (1 nmol/animal, i.c.v.)-induced response was dose-dependently attenuated by [D-Phe6, des-Met14]-bombesin (6-14) ethylamide (bombesin BB2 receptor antagonist) (15.3 and 30.6 nmol/animal, i.c.v.) and also by U-73122 (PLC inhibitor) (10 and 100 nmol/animal, i.c.v.) and RHC-80267 (diacylglycerol lipase inhibitor) (1.3 and 2.6 micromol/animal, i.c.v.). However, D-Nal-cyclo[Cys-Tyr-d-Trp-Orn-Val-Cys]-Nal-NH2 (bombesin BB1 receptor antagonist) (30 and 100 nmol/animal, i.c.v.), mepacrine (PLA2 inhibitor) (1.1 and 2.2 micromol/animal, i.c.v.) and U-73343 (inactive analog of U-73122) (100 nmol/animal, i.c.v.) had no effect. These results suggest the involvement of brain PLC/diacylglycerol lipase in the brain bombesin BB2 receptor-mediated activation of sympatho-adrenomedullary outflow in rats.

Adrenal Medulla↗
PubMed2005

Brain prostanoid TP receptor-mediated adrenal noradrenaline secretion and EP3 receptor-mediated sympathetic noradrenaline release in rats.

Sympathetic nerves release noradrenaline, whereas adrenal medullary chromaffin cells secrete noradrenaline and adrenaline. Therefore, plasma noradrenaline reflects the secretion from adrenal medulla in addition to the release from sympathetic nerves, however the exact mechanisms of adrenal noradrenaline secretion remain to be elucidated. The present study was designated to characterize the source of plasma noradrenaline induced by intracerebroventricularly (i.c.v.) administered bombesin and prostaglandin E2 in urethane-anesthetized rats. Bombesin (1.0 nmol/animal, i.c.v.) elevated plasma noradrenaline and adrenaline, while prostaglandin E2 (0.3 nmol/animal, i.c.v.) elevated only plasma noradrenaline. The bombesin-induced elevations of both catecholamines were attenuated by pretreatments with furegrelate (an inhibitor of thromboxane A2 synthase) [250 and 500 microg (0.9 and 1.8 micromol)/animal, i.c.v.)] and [(+)-S-145] [(+)-(1R,2R,3S,4S)-(5Z)-7-(3-[4-3H]-phenylsulphonyl-aminobicyclo[2.2.1]hept-2-yl)hept-5-enoic acid sodium salt] (an antagonist of prostanoid TP receptors) [100 and 250 microg (250 and 625 nmol)/animal)], and abolished by acute bilateral adrenalectomy. On the other hand, the prostaglandin E2-induced elevation of plasma noradrenaline was not influenced by acute bilateral adrenalectomy. These results suggest that adrenal noradrenaline secretion and sympathetic noradrenaline release are mediated by differential central mechanisms; brain prostanoid TP receptors activated by bombesin are involved in the adrenal noradrenaline secretion, while brain prostanoid EP (probably EP3) receptors activated by prostaglandin E2 are involved in the sympathetic noradrenaline release in rats. Brain prostanoid TP receptors activated by bombesin are also involved in the adrenal adrenaline secretion.

Adrenal Glands↗
PubMed2005

Proposed guidelines for diagnosing chronic active Epstein-Barr virus infection.

Since the initial report of unusual manifestations possibly associated with chronic active Epstein-Barr virus (EBV) infection (CAEBV), nearly three decades have passed. During this period, reported cases with this entity have dramatically increased in the world. Additionally, recent development of diagnostic procedures, including molecular biological and immunological techniques, have provided us with the ability to define certain diseases, especially malignant disorders. Guidelines, derived mainly from the current literature and recent experiences with CAEBV in Japan, for diagnosing CAEBV are proposed to clarify this enigmatic disease.

Acute Disease↗
PubMed2005

Bacteriophage therapy: a revitalized therapy against bacterial infectious diseases.

Bacteriophage (phage) therapy involves using phages or their products as bioagents for the treatment or prophylaxis of bacterial infectious diseases. Much evidence in support of the effectiveness of phage therapy against bacterial infectious diseases has accumulated since 1980 from animal model studies conducted in Western countries. Reports indicate that appropriate administration of living phages can be used to treat lethal infectious diseases caused by gram-negative bacteria, such as Escherichia coli, Pseudomonas aeruginosa, Acinetobacter baumannii, Klebsiella pneumoniae, Vibrio vulnificus, and Salmonella spp., and gram-positive bacteria, such as Enterococcus faecium and Staphylococcus aureus. The phage display system and genetically modified nonreplicating phages are also effective for treatment of Helicobacter pylori and P. aeruginosa, respectively. In addition to phage particles per se, purified phage-encoded peptidoglycan hydrolase (lysin) is also reported to be effective for the treatment of bacterial infectious diseases caused by gram-positive bacteria such as Streptococcus pyogenes, S. pneumoniae, Bacillus anthracis, and group B streptococci. All phage lysins that have been studied to date exhibit immediate and strong bacteriolytic activity when applied exogenously. Furthermore, phage-coded inhibitors of peptidoglycan synthesis (protein antibiotics), search methods for novel antibacterial agents using phage genome informatics, and vaccines utilizing phages or their products are being developed. Phage therapy will compensate for unavoidable complications of chemotherapy such as the appearance of multidrug resistance or substituted microbism.

Bacteriophages↗
PubMed2005

Eradication of Epstein-Barr virus episome and associated inhibition of infected tumor cell growth by adenovirus vector-mediated transduction of dominant-negative EBNA1.

Epstein-Barr virus (EBV) nuclear antigen 1 (EBNA1), a latent viral protein consistently expressed in infected proliferating cells, is essentially required in trans to maintain EBV episomes in cells. We constructed a mutant (mt) EBNA1 and examined whether it exerted dominant-negative effects on maintenance of the viral episome thereby leading to abrogation of EBV-infected tumor cell growth. Using lymphocyte and epithelial cell lines converted with neomycin-resistant recombinant EBV (rEBV) as models, adenovirus vector-mediated transduction of mtEBNA1, but not LacZ, brought about rapid and striking reductions in rEBV-derived wild-type EBNA1 levels and viral genomic loads in converted lines of three major viral latencies. This outcome was further validated at the single-cell level by cellular loss of G418 resistance and viral signals in situ. The mtEBNA1 transduction significantly impaired growth of naturally EBV-harboring Burkitt lymphoma cells in vitro and in vivo, largely in association with the eradication of viral episomes. Expression of mtEBNA1 per se caused no detectable cytotoxicity in EBV-uninfected cells. These results indicate that mtEBNA1 can act as a dominant-negative effector that efficiently impedes the EBV-dependent malignant phenotypes in cells regardless of viral latency or tissue origin. The mutant will afford an additional therapeutic strategy specifically targeting EBV-associated malignancies.

Adenoviridae↗
PubMed2004

CpG oligodeoxynucleotides directly induce CXCR3 chemokines in human B cells.

CpG oligodeoxynucleotides (CpG ODN) are known to elicit Th1 immune responses via TLR9. However, the precise mechanisms through which B cells are involved in this phenomenon are not fully understood. We investigated the effect of CpG ODN on the induction of Th1-chemoattractant CXCR3 chemokines, IP-10, Mig, and I-TAC, in B cells. Cells from the RPMI 8226 human B cell line and human peripheral B cells were stimulated with three distinct classes of CpG ODN. As a result, CXCR3 chemokines were strongly up-regulated by CpG-B and CpG-C, but only weakly by CpG-A. Though CXCR3 chemokines are known to be induced by IFNs, blocking mAbs against IFN receptors did not inhibit their induction by CpG-B. Induction of CXCR3 chemokines was blocked by two NF-kappaB inhibitors and a p38 inhibitor. These results strongly suggest that CXCR3 chemokines are directly induced by CpG ODN via NF-kappaB- and p38-dependent pathways in human B cells.

B-Lymphocytes↗
PubMed2004

Corticosteroid and cytokines synergistically enhance toll-like receptor 2 expression in respiratory epithelial cells.

Respiratory epithelial cells play important roles not only in host defense mechanisms, but also in inflammatory responses. Inhaled corticosteroids are widely used for the treatment of patients with inflammatory lung disorders, including asthma, chronic obstructive pulmonary disease, and sarcoidosis. Corticosteroids effectively reduce the production of inflammatory mediators, such as cytokines and chemokines. Although these molecules are also essential for host defense responses, there is no convincing evidence that inhaled corticosteroids increase susceptibility to lower respiratory tract infections. To test the involvement of Toll-like receptor (TLR) family molecules in this phenomenon, we examined the effects of various cytokines and corticosteroid on the expression of TLRs in human respiratory epithelial cells. Among the TLRs tested, TLR2 expression was significantly enhanced after stimulation with a combination of tumor necrosis factor-alpha and interferon-gamma. Dexamethasone synergistically enhanced TLR2 expression in combination with tumor necrosis factor-alpha and interferon-gamma in terms of both mRNA and protein levels. Furthermore, increased cell-surface TLR2 was functional, judging from the remarkable induction of interleukin-6, interleukin-8, and beta-defensin-2 after stimulation with peptidoglycan. These results provide evidence for a novel function of corticosteroids in airway inflammatory disorders, and indicate that the use of inhaled corticosteroids in such disorders may have a beneficial role in host defense mechanisms.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed2004

[Mother and two siblings with cockroach asthma].

We report 2 siblings, an 11 year-old girl and a 10 year-old boy, with cockroach asthma who developed the symptoms in May and October, 1999, respectively. Both children were considered as psychogenic asthma because of poor familial environment and late onset. Their mother also had asthmatic attacks since September, 2001. It became clear in the detailed clinical history that their rooms had not been cleaned up at all for a long period, and a lot of cockroaches had lived in the house. A significantly high titer of cockroach specific IgE-antibody (CAP-RAST) was detected in all three patients, and cockroach was considered as the main allergen of asthma in these patients. Although many cases with cockroach allergy including asthma have been reported in United States, it has not been recognized well in Japan yet. We would like to emphasize that cockroach should be kept in one' s mind as an important allergen of asthma.

Allergens↗
PubMed2003

Interferon-alpha/beta receptor-mediated selective induction of a gene cluster by CpG oligodeoxynucleotide 2006.

BACKGROUND: Oligodeoxynucleotides containing unmethylated CpG motifs (CpG ODN) are known to exert a strong adjuvant effect on Th1 immune responses. Although several genes have been reported, no comprehensive study of the gene expression profiles in human cells after stimulation with CpG ODN has been reported. RESULTS: This study was designed to identify a CpG-inducible gene cluster that potentially predicts for the molecular mechanisms of clinical efficacy of CpG ODN, by determining mRNA expression in human PBMC after stimulation with CpG ODN. PBMCs were obtained from the peripheral blood of healthy volunteers and cultured in the presence or absence of CpG ODN 2006 for up to 24 hours. The mRNA expression profile was evaluated using a high-density oligonucleotide probe array, GeneChip. Using hierarchical clustering-analysis, out of a total of 10,000 genes we identified a cluster containing 77 genes as having been up-regulated by CpG ODN. This cluster was further divided into two sub-clusters by means of time-kinetics. (1) Inflammatory cytokines such as IL-6 and GM-CSF were up-regulated predominantly 3 to 6 hours after stimulation with CpG ODN, presumably through activation of a transcription factor, NF-kappaB. (2) Interferon (IFN)-inducible anti-viral proteins, including IFIT1, OAS1 and Mx1, and Th1 chemoattractant IP-10, were up-regulated predominantly 6 to 24 hours after stimulation. Blocking with mAb against IFN-alpha/beta receptor strongly inhibited the induction of these IFN-inducible genes by CpG ODN. CONCLUSION: This study provides new information regarding the possible immunomodulatory effects of CpG ODN in vivo via an IFN-alpha/beta receptor-mediated paracrine pathway.

Antibodies, Monoclonal↗