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Hideki Ito

Publications and source records attributed to Hideki Ito.

At least 37 records · Page 2Linked to original sources
PubMed2003

Characterization of platelet aggregation in whole blood of laboratory animals by a screen filtration pressure method.

The characteristics of platelet aggregation of laboratory animals were investigated with whole blood and platelet-rich plasma (PRP). We measured the platelet aggregation threshold index (PATI) of whole blood and PRP aggregations induced by ADP or collagen, using a novel whole blood aggregometer, the WBA analyzer, with a screen filtration pressure (SFP) method. At 60 min after blood collection, PATI values of guinea pig, mouse, rat, dog and rabbit were 0.83, 1.78, 46.48, 49.85 and 53.42 microM for ADP-induced whole blood aggregation, respectively, whereas their PATI values for ADP-induced PRP aggregation were 1.16, 2.77, 2.65, 10.81 and 18.77 microM, respectively. These suggest that ADP-induced platelet aggregations of rat, dog and rabbit are suppressed in whole blood. PATI values of guinea pig, mouse, rat, dog and rabbit were 1.84, 0.62, 11.90, 2.34, 12.32 microg/ml for the collagen-induced whole blood aggregation, respectively, whereas their PATI values for the collagen-induced PRP aggregation were 4.21, 1.50, 5.36, 11.31, 13.30 microg/ml, respectively. Collagen-induced aggregation activity of the guinea pig, mouse and dog was significantly higher in whole blood than in the PRP. These results demonstrated that species differences in laboratory animals exist for whole blood aggregation, and that the SFP aggregometer may be useful to evaluate platelet function in various animal species.

Adenosine Diphosphate↗
PubMed2003

Phosphorylation of the vasodilator-stimulated phosphoprotein (VASP) by the anti-platelet drug, cilostazol, in platelets.

Vasodilator-stimulated phosphoprotein (VASP) is a regulator of actin dynamics in platelets and a common substrate of both cAMP- and cGMP-dependent protein kinases (PKA and PKG). Elevations of the cAMP and cGMP concentration have been shown to inhibit platelet aggregation. Intracellular levels of cAMP and cGMP are regulated by the synthesizing system of adenylate cyclases, and hydrolysis by cyclic nucleotide phosphodiesterases (PDEs). The present study examined the effect of the anti-platelet drug, cilostazol, which inhibits PDE3 activity, on VASP phosphorylation in platelets. VASP phosphorylation was examined by immunoblotting with an anti-VASP antibody, M4, and an anti-phospho-VASP antibody, 16C2. Cilostazol phosphorylated VASP at both Ser157 and Ser239 in a concentration-dependent manner, but EHNA (PDE2 inhibitor), dipyridamole and zaprinast (PDE5 inhibitors) did not. Forskolin (adenylate cyclase activator) and sodium nitroprusside (SNP, NO donor) resulted in the VASP phosphorylation, with increase in the cAMP and cGMP level, respectively. Cilostazol increased cAMP, but not cGMP levels, in platelets. EHNA, zaprinast and dipyridamole, had no effect on cAMP and cGMP levels. The PKA/PKG inhibitor, H-89, inhibited VASP phosphorylation by cilostazol. These results demonstrated that cilostazol phosphorylates VASP through the PDE3 inhibition, increase of cAMP level, and PKA activation in platelets.

Adenine↗
PubMed2003

Promoter sequences of varicella-zoster virus glycoprotein I targeted by cellular transactivating factors Sp1 and USF determine virulence in skin and T cells in SCIDhu mice in vivo.

Varicella-zoster virus (VZV) glycoprotein I is dispensable in cell culture but necessary for infection of human skin and T cells in SCIDhu mice in vivo. The gI promoter contains an activating upstream sequence that binds the cellular transactivators specificity factor 1 (Sp1) and upstream stimulatory factor (USF) and an open reading frame 29 (ORF29)-responsive element (29RE), which mediates enhancement by ORF29 DNA binding protein of immediate-early 62 (IE62)-induced transcription. Recombinants, rOKAgI-Sp1 and rOKAgI-USF, with two base pair substitutions in Sp1 or USF sites, replicated like rOKA in vitro, but infectivity of rOKAgI-Sp1 was significantly impaired in skin and T cells in vivo. A double mutant, rOKAgI-Sp1/USF, did not replicate in skin but yielded low titers of infectious virus in T cells. The repaired protein, rOKAgI:rep-Sp1/USF, was as infectious as rOKA. Thus, disrupting gI promoter sites for cellular transactivators altered VZV virulence in vivo, with variable consequences related to the cellular factor and the host cell type. Mutations in the 29RE of the gI promoter were made by substituting each of four 10-bp blocks in this region with a 10-bp sequence, GATAACTACA, that was predicted to interfere with enhancer effects of the ORF29 protein. One of these mutants, which was designated rOKAgI-29RE-3, had diminished replication in skin and T cells, indicating that ORF29 protein-mediated enhancement of gI expression contributes to VZV virulence. Mutations within promoters of viral genes that are nonessential in vitro should allow construction of recombinant herpesviruses that have altered virulence in specific host cells in vivo and may be useful for designing herpesviral gene therapy vectors and attenuated viral vaccines.

Animals↗
PubMed2003

Mutational analysis of open reading frames 62 and 71, encoding the varicella-zoster virus immediate-early transactivating protein, IE62, and effects on replication in vitro and in skin xenografts in the SCID-hu mouse in vivo.

The varicella-zoster virus (VZV) genome has unique long (U(L)) and unique short (U(S)) segments which are flanked by internal repeat (IR) and terminal repeat (TR) sequences. The immediate-early 62 (IE62) protein, encoded by open reading frame 62 (ORF62) and ORF71 in these repeats, is the major VZV transactivating protein. Mutational analyses were done with VZV cosmids generated from parent Oka (pOka), a low-passage clinical isolate, and repair experiments were done with ORF62 from pOka and vaccine Oka (vOka), which is derived from pOka. Transfections using VZV cosmids from which ORF62, ORF71, or the ORF62/71 gene pair was deleted showed that VZV replication required at least one copy of ORF62. The insertion of ORF62 from pOka or vOka into a nonnative site in U(S) allowed VZV replication in cell culture in vitro, although the plaque size and yields of infectious virus were decreased. Targeted mutations in binding sites reported to affect interaction with IE4 protein and a putative ORF9 protein binding site were not lethal. Single deletions of ORF62 or ORF71 from cosmids permitted recovery of infectious virus, but recombination events repaired the defective repeat region in some progeny viruses, as verified by PCR and Southern hybridization. VZV infectivity in skin xenografts in the SCID-hu model required ORF62 expression; mixtures of single-copy recombinant Oka Delta 62 (rOka Delta 62) or rOka Delta 71 and repaired rOka generated by recombination of the single-copy deletion mutants were detected in some skin implants. Although insertion of ORF62 into the nonnative site permitted replication in cell culture, ORF62 expression from its native site was necessary for cell-cell spread in differentiated human skin tissues in vivo.

Animals↗
PubMed2003

Differentiation of varicella-zoster virus ORF47 protein kinase and IE62 protein binding domains and their contributions to replication in human skin xenografts in the SCID-hu mouse.

To investigate the role of the ORF47 protein kinase of varicella-zoster virus (VZV), we constructed VZV recombinants with targeted mutations in conserved motifs of ORF47 and a truncated ORF47 and characterized these mutants for replication, phosphorylation, and protein-protein interactions in vitro and for infectivity in human skin xenografts in the SCID-hu mouse model in vivo. Previous experiments showed that ROka47S, a null mutant that makes no ORF47 protein, did not replicate in skin in vivo (J. F. Moffat, L. Zerboni, M. H. Sommer, T. C. Heineman, J. I. Cohen, H. Kaneshima, and A. M. Arvin, Proc. Natl. Acad. Sci. USA 95:11969-11974, 1998). The construction of VZV recombinants with targeted ORF47 mutations made it possible to assess the effects on VZV infection of human skin xenografts of selectively abolishing ORF47 protein kinase activity. ORF47 mutations that resulted in a C-terminal truncation or disrupted the DYS kinase motif eliminated ORF47 kinase activity and were associated with extensive nuclear retention of ORF47 and IE62 proteins in vitro. Disrupting ORF47 kinase function also resulted in a marked decrease in VZV replication and cutaneous lesion formation in skin xenografts in vivo. However, infectivity in vivo was not blocked completely as long as the capacity of ORF47 protein to bind IE62 protein was preserved, a function that we identified and mapped to the N-terminal domain of ORF47 protein. These experiments indicate that ORF47 kinase activity is of critical importance for VZV infection and cell-cell spread in human skin in vivo but suggest that it is the formation of complexes between ORF47 and IE62 proteins, both VZV tegument components, that constitutes the essential contribution of ORF47 protein to VZV replication in vivo.

Animals↗
PubMed2003

Construction of varicella-zoster virus recombinants from parent Oka cosmids and demonstration that ORF65 protein is dispensable for infection of human skin and T cells in the SCID-hu mouse model.

We generated an ORF65 deletion mutant by using a cosmid system constructed from the genome of a low-passage clinical isolate (P-Oka). Using the SCID-hu mouse model, we demonstrated that the ORF65 protein is dispensable for viral replication in skin and T cells, which are critical host cell targets during primary varicella-zoster virus infection.

Animals↗
PubMed2003

Requirement of varicella-zoster virus immediate-early 4 protein for viral replication.

Varicella-zoster virus (VZV) is an alphaherpesvirus that causes two diseases, chickenpox and zoster. VZV open reading frame 4 (ORF4) encodes the immediate-early 4 (IE4) protein, which is conserved among alphaherpesvirus and has transactivation activity in transient transfections. To determine whether the ORF4 gene product is essential for viral replication, we used VZV cosmids to remove ORF4 from the VZV genome. Deleting ORF4 was incompatible with recovery of infectious virus, whereas transfections done by using repaired cosmids with ORF4 inserted at a nonnative site yielded virus. To analyze the functional domain of IE4, we introduced a mutation altering the C-terminal amino acids, KYFKC (K443S), which was designed to disrupt the dimerization of IE4 protein. Transfections with these mutant cosmids yielded no virus, indicating that this KYFKC motif was essential for IE4 function.

Dimerization↗
PubMed2002

Anatomy of the planarian Dugesia japonica I. The muscular system revealed by antisera against myosin heavy chains.

The planarian Dugesia japonica has two genes encoding myosin heavy chain, DjMHC-A and B (Kobayashi et al., 1998). We produced antibodies specifically recognizing each myosin heavy chain protein using their carboxyl terminal regions expressed in E. coli as antigens. Immunohistochemical analyses of sections and whole-mount specimens revealed the detailed structure and distribution of each type of muscle fiber in the planarian. In general, the MHC-A muscle fibers were distributed beneath the epithelial layers, namely, they were observable in the pharynx, the mouth, the intestine, the eyes and the body wall. In the pharynx, only MHC-A muscle fibers were present. In contrast, the MHC-B muscle fibers were distributed in the mesenchyme as dorso-ventral and transverse muscles, and in the body wall. The body-wall muscles were composed of an outer layer of circular MHC-A muscles and inner longitudinal and intermediate diagonal MHC-B muscle layers. Thus, two types of muscle fibers were distinguished by their distribution in the planarian.

Animals↗
PubMed2002

[Development of a new method for simple dietary education in elderly individuals with diabetes mellitus].

Some elderly diabetic patients find it difficult to understand conventional dietary and nutritional education using a Japanese food exchange list. We developed a new method for simple dietary education including several dietary instructions. We compared the effects of simple dietary education on food intake, nutritional components, and glycemic control with conventional dietary education, using a randomized control trial. We randomly allocated 30 new elderly diabetic outpatients and 38 outpatients who had been visiting our clinic for a long time to the simple education group and the conventional education group. Before, and 2 or 3 months after simple or conventional education, we assessed food intake and nutritional components for a week using Yoshimura's food frequency questionnaire. In the new diabetic patients, simple and conventional nutritional education similarly reduced HbA1c levels as well as intakes of total energy, sweets, and fruits after the education. However, patients who had been visiting for a long time had no significant differences in total energy intake and HbA1c levels between before and after education in both the simple and conventional groups. Our results suggest that simple dietary education is useful and effective for elderly diabetic patients on their first visit.

Aged↗
PubMed2002

Report of the Japan Atherosclerosis Society (JAS) Guideline for Diagnosis and Treatment of Hyperlipidemia in Japanese adults.

This paper described the Guideline for Diagnosis and Management of Hyperlipidemias for Prevention of Atherosclerosis proposed by The Japan Atherosclerosis Society (JAS) Guideline Investigating Committee (1,995-2,000) under the auspices of the JAS Board of Directors. 1) The guideline defines the diagnostic criteria for serum total cholesterol (Table 1), LDL-cholesterol (Table 1), triglycerides (Table 4) and HDL-cholesterol (Table 7). It also indicates the desirable range (Table 1), the initiation levels of management (Table 2) and the target levels of treatment (Table 2) for total and LDL-cholesterol. 2) Though both total and LDL-cholesterol are shown as atherogenic parameter in the guideline, the use of LDL-cholesterol, rather than total cholesterol, is encouraged in daily medical practice and lipid-related studies, because LDL-cholesterol is more closely related to atherosclerosis. 3) Elevated triglycerides and low HDL-cholesterol are included in the risk factors, since no sufficient data have been accumulated to formulate the guideline for these two lipid disorders. 4) Emphasis is laid on evaluation of risk factors of each subject before starting any kind of treatment (Table 2). 5) This guideline is applied solely for adults (age 20-64). Lipid abnormalities in children or the youth under age 19, and the elderly with an age over 65 have to be evaluated by their own standard. 6) This part of the guideline gives only the diagnostic aspects of hyperlipidemias. The part of management and treatment will follow in the second section of the guideline that will be published in future.

Adult↗
PubMedDate not supplied

Cognitive dysfunction associates with white matter hyperintensities and subcortical atrophy on magnetic resonance imaging of the elderly diabetes mellitus Japanese elderly diabetes intervention trial (J-EDIT).

BACKGROUND: Type 2 diabetes is associated with cognitive dysfunction and increases the risk of dementia in the elderly. The aim of this study was to explore, by means of magnetic resonance (MR) imaging, possible relationships among clinical profiles of diabetes, cognitive function, white matter hyperintensities (WMHs) and subcortical brain atrophy. METHODS: Data were obtained from 95 nondemented type 2 diabetic participants aged 65 years or over, enrolled in an intervention trial for Japanese elderly diabetic patients. Cognitive function was measured with neuropsychiatric tests, including mini-mental state examination (MMSE), verbal memory, digit symbol substitution and Stroop tests. Hyperintensity was classified into periventricular, deep white matter, thalamic and basal ganglia. Four ventricle-to-brain ratios were used to measure subcortical atrophy. To identify clinical features of diabetes, indices of glycemic control, lipid metabolism, blood pressure and complications were examined. Canonical correlation analysis and regression analysis were used to assess correlation. RESULTS: Scores for digit symbol substitution and MMSE negatively correlated with WMHs in the parietal lobe and hyperintensities in the thalamus, respectively. Lower scores for memory and digit symbol substitution showed positive association with enlarged subcortical atrophy adjacent to lateral ventricles. There was no association between clinical pictures of diabetic patients with cognitive dysfunction and of those with morphological changes in the brain. CONCLUSIONS: Impaired cognitive domains of the speed of mental processes and memory were associated with WMHs and subcortical atrophy. Degenerative changes in the cerebral small vessels may constitute predictive factors for the rate of cognitive dysfunction in elderly diabetic patients.

Aged↗