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Yasuo Suzuki

Publications and source records attributed to Yasuo Suzuki.

At least 73 records · Page 4Linked to original sources
PubMed2004

Evolutional analysis of human influenza A virus N2 neuraminidase genes based on the transition of the low-pH stability of sialidase activity.

The 1957 and 1968 human pandemic influenza A virus strains as well as duck viruses possess sialidase activity under low-pH conditions, but human H3N2 strains isolated after 1968 do not possess such activity. We investigated the transition of avian (duck)-like low-pH stability of sialidase activities with the evolution of N2 neuraminidase (NA) genes in human influenza A virus strains. We found that the NA genes of H3N2 viruses isolated from 1971 to 1982 had evolved from the side branches of NA genes of H2N2 epidemic strains isolated in 1968 that were characterized by the low-pH-unstable sialidase activities, though the NA genes of the 1968 pandemic strains preserved the low-pH-stable sialidase. These findings suggest that the prototype of the H3N2 epidemic influenza strains isolated after 1968 probably acquired the NA gene from the H2N2 low-pH-unstable sialidase strain by second genetic reassortment in humans.

Amino Acid Sequence↗
PubMed2004

Antigenic alteration of influenza B virus associated with loss of a glycosylation site due to host-cell adaptation.

Effects of host-cell adaptation of the hemagglutinin (HA) protein were evaluated by the analyses of four pairs of recent influenza B field isolates, each pair consisting of an Madin Darby canine kidney (MDCK)- and an embryonated chicken egg-derived isolates from the same clinical specimen. Among the isolates examined, all of the MDCK-derived isolates retained glycosylation site at amino acid 197 on the HA1 molecule, whereas three egg-derived isolates lost it. Antigenic difference in the HA molecule between an MDCK- and an egg-derived isolates of three of these pairs was demonstrated to be associated with the glycosylation 197. Replication of the MDCK-derived isolates was suppressed in eggs, suggesting that the presence of the glycosylation 197 was disadvantageous to replication in eggs. Virus-binding affinity assay revealed that the loss of carbohydrate chain did not significantly alter the preferential recognition of sialic acid linkage. Immunogenicity and vaccine efficacy of an MDCK- and an egg-derived clones of B/Akita/27/2001, the former retained the glycosylation 197 and the latter lost it, were compared in a hamster model. When formalin-inactivated whole virion vaccines prepared from the paired isolates were administered into hamsters, no significant difference between them was observed in protective ability against challenges by the homologous and heterologous clones. Implication of the egg adaptation of influenza virus to antigenic surveillance of the field isolates as well as the selection of vaccine strains, and possibility of the involvement of the viral protein(s) other than the HA in the egg adaptation were discussed.

Animals↗
PubMed2004

Adsorptive granulocyte and monocyte apheresis for refractory Crohn's disease: an open multicenter prospective study.

BACKGROUND: Active Crohn's disease (CD) is often associated with elevated levels of platelets, granulocytes, and monocytes that are activated and resistant to apoptosis. The level of neutrophils in the intestinal mucosa has been quantitatively related to the severity of intestinal inflammation in CD. We postulated that patients with CD that is refractory to conventional medications might respond to a reduction of granulocytes and monocytes by adsorptive apheresis. METHODS: Twenty-one patients with a CD activity index (CDAI) of 200-399 and unresponsive to standard medication, which included nutritional intervention, received granulocyte and monocyte adsorptive apheresis (GCAP) as an adjunct to their ongoing medication. GCAP was performed with an Adacolumn, which adsorbs granulocytes, monocytes, and a small fraction of lymphocytes (FcgammaR and complement receptor-bearing leucocytes). Patients received one GCAP session/week for 5 consecutive weeks. CDAI, International Organization for the Study of Inflammatory Bowel Disease (IOIBD), and IBD questionnaire (IBDQ) scores were evaluated. RESULTS: During the initial conventional/nutritional therapy, no significant improvement was seen in any patient. However, at week 7 of GCAP therapy, significant improvements in CDAI, IOIBD, and IBDQ scores were observed. The CDAI, IOIBD, and IBDQ scores before GCAP were 275.6+/-54.2, 3.4+/-1.4, and 152+/-22, respectively. The corresponding values after GCAP were 214.8+/-89.2 (P=0.0005), 2.54+/-1.5 (P=0.0224), and 165+/-29 (P=0.0327), respectively. CONCLUSIONS: GCAP could be effective for inducing remission and improving quality of life in patients with active CD that is refractory to conventional therapy.

Adolescent↗
PubMed2004

High incidence of orbital malignant lymphoma in Japanese patients.

PURPOSE: To review 244 cases of orbital tumors to determine pathologic findings in Japanese patients. DESIGN: Observational case series. METHODS: We studied the pathology and origin of tumors in the orbit in 244 consecutive Japanese patients with orbital tumors at our institution from 1981 through 2002 (age 0 to 90 years, mean, 48.7 years; 114 men, 130 women). RESULTS: The most common tumors were lymphoproliferative diseases (n = 114, 42.5%), including malignant lymphoma (n = 59, 24.1%) and reactive lymphoid hyperplasia (n = 45, 18.4%), pleomorphic adenoma (n = 21, 8.6%), and cavernous hemangioma (n = 18, 7.4%). CONCLUSION: The incidence of lymphoproliferative diseases, especially malignant lymphoma, was very high in Japanese patients.

Adolescent↗
PubMed2004

Convergence eye movements evoked by microstimulation of the rostral superior colliculus in the cat.

Results of our previous studies suggest that the circumscribed area in the rostral superior colliculus (SC) of the cat is involved in the control of accommodation. Accommodation is closely linked with vergence eye movements. In this study, we investigated whether or not vergence eye movements are evoked by microstimulation of the rostral SC in the cat. In addition, we studied the effect of chemical inhibition of the rostral SC on visually guided vergence eye movements. This study was conducted on three cats, weighing 2.5-3.5 kg. The animals were trained to carry out visually guided saccade and convergence tasks. Eye movements were measured using search coils placed on both eyes. We recorded eye movements evoked by microstimulation of the rostral SC in the alert cats. Muscimol was injected into the rostral SC, and the effect of SC inactivation on visually guided vergence eye movements was investigated. Convergence eye movements were evoked by low-current stimulation (< 30 microA) of a circumscribed area in the intermediate layers of the rostral SC on one side. Spontaneous saccades were interrupted by the stimulation of the low-threshold area for evoking convergence. Visually guided convergence eye movements were severely diminished by the injection of muscimol into the low-threshold area for evoking convergence of the SC. The rostral SC is related to the control of vergence eye movements as well as accommodation. The rostral SC may be involved in the functional linkage between accommodation, convergence and visual fixation.

Action Potentials↗
PubMed2004

Selective granulocyte and monocyte adsorptive apheresis as a first-line treatment for steroid naïve patients with active ulcerative colitis: a prospective uncontrolled study.

Corticosteroid therapy of ulcerative colitis (UC) is associated with frequent adverse side effects and poor quality of life. Recently, adsorptive granulocyte and monocyte/macrophage apheresis has shown efficacy in patients with severe steroid refractory UC. The objective of this study was to investigate if, instead of corticosteroids, adsorptive leukocytapheresis has efficacy as the first-line therapy for steroid-naïve patients with active UC. Twenty patients, aged 15-49 years, with a mean clinical activity index (CAI) of 8.6 were recruited. Adsorptive leukocytapheresis was done with Adacolumn, which contains cellulose acetate beads as adsorptive carriers for granulocytes and monocytes (FcgammaR and complement receptors expressing leukocytes). Each patient received 6 to 10 leukocytapheresis sessions of 60-min duration, at 2 sessions/week. Efficacy was assessed 1 week after the last session. Post treatment, the mean CAI was 3.0 (P = 0001), and 17 of 20 patients (85%) were in remission. There were significant falls in C-reactive protein (P = 0.0003), total white cell counts (P = 0.003), neutrophils (P = 0.0029), and monocytes (P = 0.0038), an increase in lymphocytes (P = 0.001), and increases in the blood levels of soluble TNF-alpha receptors I (P = 0.0007) and II (P = 0.0045) in the column outflow (blood return to the patients). Further, at 8 months, 60% of patients had maintained their remission. No severe side effects were reported. In conclusion, adsorptive leukocytapheresis should reduce corticosteroid therapy in patients with moderate UC; cases with early-stage active disease may benefit most.

Adolescent↗
PubMed2004

Superior oblique myokymia caused by vascular compression.

A 49-year-old man had left superior oblique myokymia for eight years. Magnetic resonance images with enhanced spoiled gradient recalled acquisition in the steady state (SPGR) and flow imaging using steady acquisition (FIESTA) disclosed a branch of the superior cerebellar artery lying on the root exit zone of the left trochlear nerve. Posterior fossa craniotomy confirmed the imaging findings. A Teflon pad was placed between the compressing artery and the trochlear nerve. The patient's superior oblique myokymia has completely resolved with a one-year follow-up. Only one such case has been previously reported. This is the first report to display the imaging findings.

Cerebral Arteries↗
PubMed2004

Retroperitoneal mucinous cystadenoma: report of two cases and review of the literature.

Primary retroperitoneal cystic tumor is extremely rare, and its histogenesis and biological behavior remain speculative. Two surgical cases of retroperitoneal mucinous cystadenoma (Case 1, an 18-year-old woman; and Case 2, an 85-year-old woman) are reported. The cystadenomas in these cases were mainly lined by a monolayer of columnar or thin flat cells. Case 1 was positive for mucin and epithelial membrane antigen, whereas Case 2 was positive for a mesothelial marker (calretinin). Ciliated epithelium was also interspersed in Case 2. Some parts showed papillary projections, resembling well-differentiated papillary mesothelioma. Within the cyst walls of both cases, ovarian-like stroma that was positive for both estrogen and progesterone receptors was found. Interestingly, focal nodular hyperplasia of the liver was also detected in Case 1. We believe the retroperitoneal mucinous cystadenoma might have arisen from the peritoneum via mucinous epithelial metaplasia with a phenotype of extragenital Mullerian system.

Adolescent↗
PubMed2004

In vitro and in vivo inhibitory effects of disodium cromoglycate on influenza virus infection.

Disodium cromoglycate (DSCG) is one of the safest drugs for the prevention of bronchial asthma and allergic rhinitis attacks. The effect of DSCG on acute upper respiratory tract viral infection is still controversial. Here we investigated DSCG inhibition of influenza virus infection in vivo and in vitro. In vivo effects of DSCG on viral infection were assessed using a murine model of respiratory tract infection. Intranasal administration of DSCG protected mice from death induced by infection with influenza virus A/PR/8/34. We analyzed DSCG anti-viral effects in vitro by either (i) treating cells prior to viral adsorption, (ii) treating cells concurrently with viral adsorption, or (iii) treating cells after viral adsorption. DSCG treatment of cells during or after, but not before, viral adsorption significantly inhibited influenza viral infection, indicating DSCG acts on events late in viral infection. DSCG exerts anti-influenza effect both in vitro and in vivo at the doses compatible with treatment for asthma. DSCG marginally inhibited influenza viral neuraminidase and membrane fusion functions, suggesting that DSCG inhibition of viral neuraminidase and fusion activities may partially mediate this anti-influenza effect. Our results indicate that treatment of patients including children with DSCG may take advantages for prevention from influenza virus infection.

Administration, Intranasal↗
PubMed2004

Epigallocatechin-3-O-gallate inhibits fibroblast contraction of floating collagen gel: interaction between epigallocatechin-3-O-gallate and platelet derived growth factor.

The effects of (-)-epigallocatechin gallate (EGCG) on the contraction of floating collagen gel by fibroblasts were investigated. EGCG inhibited collagen gel contraction dose-dependently. On the basis of the fact that platelet-derived growth factor (PDGF) is one of the serum components with stimulatory activity in collagen gel contraction, we examined the possibility that interaction between EGCG and PDGF may be involved in this inhibition mechanism. We confirmed this by recombinant PDGF-BB in the present system and we found that EGCG inhibited PDGF-stimulated collagen gel contraction. The results of affinity chromatography indicated that PDGF was bound by EGCG immobilized on agarose gel as detected by enzyme-linked immunoassay and Western blotting. These findings suggest that binding of EGCG to PDGF is at least partly involved in the mechanism of inhibition of collagen gel contraction by EGCG.

Catechin↗
PubMed2004

Use of rubidium, manganese, and zinc as tracers to measure intestinal permeability by PIXE analysis: basal study in an experimental enteritis model.

Intestinal permeability has been suggested to be closely linked with the etiology or activity of Crohn's disease. However, current methods for measurement of intestinal permeability are too laborious for routine examination, as they require urine collection and/or use of radioisotopes. The present study was performed to develop a more convenient and safer method for assessing intestinal permeability using blood samples rather than urine. Rats with indomethacin-induced enteritis were orally administered Rb, Mn, and Zn as tracers. Intestinal permeability was determined by assaying the levels of Rb, Mn, and Zn in blood samples by particle-induced X-ray emission (PIXE). The distributions of Rb, Mn, and Zn in the small intestine after administration were analyzed by micro-PIXE. The conventional PIXE analysis showed that the levels of Rb and Zn in the blood in the enteritis group were correlated with the grade of enteritis. The micro-PIXE analysis showed that Rb, Mn, and Zn were translocated into the wall of the proximal small intestine 5 min after administration, and this effect was more conspicuous in the enteritis group than in controls. Analysis of blood or small intestine tissue samples using the PIXE allows determination of both intestinal permeability and the route of permeation.

Animals↗
PubMed2003

Cerebroside sulfotransferase deficiency ameliorates L-selectin-dependent monocyte infiltration in the kidney after ureteral obstruction.

Mononuclear cells infiltrating the interstitium are involved in renal tubulointerstitial injury. The unilateral ureteral obstruction (UUO) is an established experimental model of renal interstitial inflammation. In our previous study, we postulated that L-selectin on monocytes is involved in their infiltration into the interstitium by UUO and that a sulfated glycolipid, sulfatide, is the physiological L-selectin ligand in the kidney. Here we tested the above hypothesis using sulfatide- and L-selectin-deficient mice. Sulfatide-deficient mice were generated by gene targeting of the cerebroside sulfotransferase (Cst) gene. Although the L-selectin-IgG chimera protein specifically bound to sulfatide fraction in acidic lipids from wild-type kidney, it did not show such binding in fractions of Cst(-/-) mice kidney, indicating that sulfatide is the major L-selectin-binding glycolipid in the kidney. The distribution of L-selectin ligand in wild-type mice changed after UUO; sulfatide was relocated from the distal tubules to the peritubular capillaries where monocytes infiltrate, suggesting that sulfatide relocated to the endothelium after UUO interacted with L-selectin on monocytes. In contrast, L-selectin ligand was not detected in Cst(-/-) mice irrespective of UUO treatment. Compared with wild-type mice, Cst(-/-) mice showed a considerable reduction in the number of monocytes/macrophages that infiltrated the interstitium after UUO. The number of monocytes/macrophages was also reduced to a similar extent in L-selectin(-/-) mice. Our results suggest that sulfatide is a major L-selectin-binding molecule in the kidney and that the interaction between L-selectin and sulfatide plays a critical role in monocyte infiltration into the kidney interstitium.

Animals↗
PubMed2003

Inhibition of influenza A virus sialidase activity by sulfatide.

Sulfatide, which binds to influenza A viruses and prevents the viral infection, was found to inhibit the sialidase activities of influenza A viruses in a pH-dependent manner. The kinetic parameters of the effect of sulfatide on the sialidase activities of human influenza A viruses using fluorometric assay indicated that sulfatide was a powerful and non-competitive type inhibitor in low-pH conditions.

Animals↗
PubMed2003

Action of microparticles of heparin and alginate crosslinked gel when used as injectable artificial matrices to stabilize basic fibroblast growth factor and induce angiogenesis by controlling its release.

Alginate is an acidic polysaccharide like the glycosaminoglycans and is a candidate for use as an artificial matrix. We developed a novel alginate gel sheet that is crosslinked with heparin (H/A gel sheet) and discovered its properties of releasing biologically active basic fibroblast growth factor (bFGF), a representative member of the heparin-binding growth factors (HBGFs), for about 1 month in vitro and of inducing angiogenesis in vivo. In the present study, the H/A gel sheet was mechanically broken up to produce easily injectable 50- to 200 microm microparticles of the gel (H/A gel particles), the properties of which were analyzed. The H/A gel particles cumulatively released 2.8 times as much bFGF as the H/A gel sheet, despite both having the same amount of bFGF adsorbed onto their gels. In addition, the bFGF-adsorbed H/A gel particles released a significant amount of bFGF, which stimulated cellular growth in a culture of human umbilical venous endothelial cells for up to 5 weeks. The subcutaneous injection of the bFGF-adsorbed H/A gel particles induced the formation of numerous microvessels in the tissue surrounding the gel. These results indicate that the H/A gel particles not only stabilize bFGF by preventing the occurrence of proteolysis or denaturation but also modulate its release from the gel. Because the H/A gel particles can be easily injected into the target tissues, this artificial matrix may be useful for the local delivery of HBGFs in the treatment of ischemic arterial diseases, as well as for regenerating or constructing tissues.

Alginates↗