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Biomedical subjects

H Matsuda

Publications and source records attributed to H Matsuda.

At least 523 records · Page 29Linked to original sources
PubMed1998

Identification of a peptide inducing experimental autoimmune uveoretinitis (EAU) in H-2Ak-carrying mice.

When certain strains of mice bearing H-2Ak are immunized with the interphotoreceptor retinoid-binding protein (IRBP), EAU is induced. Thus far uveitogenic determinant(s) has not been determined in the H-2Ak mouse system. In addition it is hard to prepare purified IRBP. In the present study, to circumvent these problems we attempted to identify uveitogenic peptides derived from bovine IRBP in H-2Ak haplotype mice. Six peptides which had been selected according to the H-2Ak binding motif (Dxxxxxxxx[A, R, T]) were synthesized. We report here that all the peptides are immunogenic but only one peptide, K2, which consisted of IRBP201-216 residues, induces EAU in various mice carrying H-2Ak. Amino acid substitution of K2 revealed that the core region interacted with both H-2Ak and T cell antigen receptor (TCR). The amino acid sequence of the core region derived from bovine IRBP was identical to the corresponding region of mouse IRBP. In addition, K2 appeared to be a natural peptide antigen processed from bovine IRBP. Altogether, we concluded that K2 is one of the natural autoantigens involved in induction of EAU in H-2Ak mice.

Amino Acid Sequence↗
PubMed1998

Neoplastic thymic epithelial cells of human thymoma support T cell development from CD4-CD8- cells to CD4+CD8+ cells in vitro.

Human thymoma is a thymic epithelial cell tumour which often contains a large number of immature T cells and is frequently associated with autoimmune diseases. Since thymic epithelial cells play key roles in the development and selection of T cells in the normal thymus, we hypothesized that the neoplastic thymic epithelial cells of thymoma may support T cell differentiation in the tumour. We characterized CD4-CD8- cells in thymoma and applied an in vitro reconstitution culture system using the CD4-CD8- cells and the neoplastic epithelial cells isolated from thymoma. CD34, a stem cell marker, was expressed on 29.9 +/- 12.2% of CD4-CD8- cells in thymoma. TCRgammadelta was expressed on 27.4 +/- 15.1% of CD4-CD8- cells and CD19, a B cell marker, was expressed on 14.1 +/- 23.1% of CD4-CD8- cells. CD4-CD8- cells expressed both IL-7R alpha-chain and common gamma-chain. Purified CD4-CD8- cells from thymomas were cultured with the neoplastic epithelial cells, and their differentiation into CD4+CD8+ cells via CD4 single-positive intermediates was observed within 9 days' co-culture in the presence of recombinant IL-7. Furthermore, we examined the reconstitution culture using CD34+CD4-CD8- cells purified from normal infant thymus. The CD34+CD4-CD8- cells in normal thymus also differentiated to CD4+CD8+ cells in the allogeneic co-culture with the neoplastic epithelial cells of thymoma. These results indicate that the tumour cells of thymoma retain the function of thymic epithelial cells and can induce differentiation of T cells in thymoma.

Adult↗
PubMed1998

Immunohistochemical localisation of regulatory neuropeptides in human circumvallate papillae.

The occurrence and distribution of neuropeptide-containing nerve fibres in the human circumvallate papillae were examined by the peroxidase-antiperoxidase immunolocalisation method using surgical specimens that had not been subjected to radiotherapy, and the abundance of neuropeptide-containing fibres was expressed as the percentage of total nerve fibres demonstrated by protein gene product (PGP) 9.5 immunoreactivity for a quantitative representation of these peptidergic fibres. Substance P (SP) and calcitonin gene-related peptide (CGRP) immunoreactive (IR) nerve fibres were densely distributed in the connective tissue core of the circumvallate papillae, and some SP and CGRP-IR fibres were associated with the taste buds. A moderate number of vasoactive intestinal polypeptide (VIP)-IR fibres and a few galanin (GAL)-IR fibres were also seen in the connective tissue core and subepithelial layer. There were, however, no VIP-IR or GAL-IR fibres associated with the taste buds. Neuropeptide Y (NPY)-IR fibres were few and were associated with the blood vessels. Within the epithelium of the circumvallate papillae, no peptidergic fibres were found, although a number of PGP 9.5-IR fibres were detected. The abundance of SP, CGRP, VIP, and GAL-IR fibres expressed as the percentage of total PGP 9.5 IR fibres was 25.35+/-3.45%, 22.18+/-3.26%, 10.23+/-1.18%, and 4.12+/-1.05%, respectively. The percentage of NPY-IR fibres was below 3%. In a deeper layer of the papillae, a few VIP, GAL, and NPY-IR ganglion cells were found, and VIP immunoreactivity was detected in a few cells of the taste buds. There was no somatostatin, leucine enkephalin, or methionine enkephalin immunoreactivity in the circumvallate papillae. These results suggest that the dense SP and CGRP-IR fibres within the connective tissue core of the human circumvallate papillae may be involved in the deep sensation of the tongue.

Adult↗
PubMed1998

Immunologic abnormalities exhibited in IL-7 transgenic mice with dermatitis.

Interleukin (IL)-7 transgenic mice, which we established previously, developed severe dermatitis characterized by massive infiltration of gammadelta T cells in the dermal lesion. To fully understand the pathology of this intriguing skin disease, we examined several immunologic features of dermis infiltrating lymphocytes from the lesional skin of IL-7 transgenic mice. We observed a moderate response to mitogens, a poor response to alloantigens, and the absence of cytotoxic activities to several tumor cell lines and skin derived cells regardless of the presence of IL-2 or IL-7. On the other hand, dermis infiltrating lymphocytes could proliferate with exogenous IL-2 and IL-7. Moreover, reverse transcriptase polymerase chain reaction and fluorescence activated cell sorter analysis revealed that dermis infiltrating lymphocytes expressed various cytokines including IL-4 and IL-7, and several activation markers for T cells (CD44, CD69, IL-2R alpha), in addition to IL-7R alpha. In the sera of the affected mice, hyper epsilon-globulinemia was observed. These findings suggested that dermis infiltrating lymphocytes proliferated in an activated state in the skin lesion in an autocrine and/or paracrine manner and produced Th2 type cytokines that might evoke immunologic abnormalities. This study and previous findings suggest that IL-7 transgenic mouse with dermatitis offer the potential of serving as a useful tool for investigating the immunologic role of cutaneous gammadelta T cells, especially their participation in IgE production in vivo.

Animals↗
PubMed1998

Serotonin enhances the production of type IV collagen by human mesangial cells.

BACKGROUND: The plasma concentration of 5-hydroxytryptamine (5-HT) in diabetic patients is higher than that in normal subjects. Since recent reports have demonstrated the presence of 5-HT2A receptor in glomerular mesangial cells, it is possible that 5-HT may be involved in the development of diabetic nephropathy through the 5-HT2A receptor in mesangial cells. Because expansion of the glomerular mesangial lesion is a characteristic feature of diabetic nephropathy, we examined the effect of 5-HT on the production of type IV collagen by human mesangial cells. METHODS: Human mesangial cells were incubated with 5-HT with or without 5-HT receptor antagonists, protein kinase C (PKC) inhibitor or transforming growth factor-beta (TGF-beta) antibody. Type IV collagen mRNA and protein concentration in medium were measured by Northern blot analysis and enzyme-linked immunosorbent assay (ELISA), respectively. TGF-beta mRNA and bioactivity in the medium were measured by Northern blot analysis and bioassay using mink lung epithelial cells, respectively. RESULTS: 5-HT stimulated the production of type IV collagen by human mesangial cells, which was inhibited by ketanserin and sarpogrelate hydrochloride, 5-HT2A receptor antagonists, but not by ondansetron, a 5-HT3 receptor antagonist. 5-HT increased the bioactivities of both active and total TGF-beta. However, the 5-HT-enhanced production of type IV collagen was completely inhibited by an anti-TGF-beta antibody. Furthermore, a PKC inhibitor, calphostin C, inhibited the 5-HT-induced increase in type IV collagen secretion, and the activity of membrane PKC was increased by 5-HT. Phorbol ester activated type IV collagen production as well as active and total TGF-beta. Calphostin C completely inhibited the 5-HT-enhanced activity of active TGF-beta, but did not inhibit exogenous TGF-beta-induced increase in type IV collagen secretion. CONCLUSIONS: Our results suggest that 5-HT-enhanced production of type IV collagen by human mesangial cells is mediated by activation of PKC and subsequent increase in active TGF-beta activity.

Cells, Cultured↗
PubMed1998

A novel technique for cardiopulmonary bypass using vacuum system for venous drainage with pressure relief valve: an experimental study.

To decrease the circuit priming volume, develop safety, and simplify the equipment, a cardiopulmonary bypass (CPB) circuit using a vacuum suction venous drainage system with a pressure relief valve was developed. The efficacy of this vacuum system was compared to that of a conventional siphon system. The system contains a powerful vacuum generator and a pressure relief valve to keep the negative pressure constant when blood suction is used. Using 8 mongrel dogs, the feasibility and the efficacy of this CPB system was tested. The changes in the negative pressure in the reservoir were within 5 mm Hg whether the suction lines were switched on or off. In all animals the amount of blood in the venous reservoir was stable throughout bypass. The decrease of priming volume was from 725 ml (siphon system) to 250 ml (vacuum system). At the end of CPB, the levels of hemoglobin in the vacuum system were significantly higher than those in the siphon system. These results demonstrated that this vacuum drainage system can provide simplification and a miniaturization of the cardiopulmonary bypass circuit resulting in low hemodilution during CPB.

Animals↗
PubMed1998

Minimally invasive cardiac surgery: current status and perspective.

Recently, the minimally invasive approach has become a growing aspect in the field of cardiac surgery with the goal of eliminating cardiopulmonary bypass (CPB) and/or median sternotomy. In coronary bypass surgery, the application of this approach is direct anastomosis, primarily of the left internal thoracic artery to the left descending coronary artery under a beating condition without the use of CPB through a small left thoracotomy minimally invasive direct coronary artery bypass (MIDCAB). In the repair of intracardiac lesions, CPB cannot be excluded, but a small right parasternal incision or small partial sternotomy (ministernotomy) has been applied for congenital defects and mitral and aortic valve lesions. With technological advances in CPB, these approaches may become more popular in the near future.

Anastomosis, Surgical↗
PubMed1998

Antinociceptive and anti-inflammatory activities of limonin isolated from the fruits of Evodia rutaecarpa var. bodinieri.

Antinociceptive and anti-inflammatory effects of limonin isolated from the dried fruits of Evodia rutaecarpa var. bodinieri were investigated. Oral administration of 30 or 100 mg/kg limonin significantly decreased the frequency of licking and biting behavior within a unit of time at the late phase without affecting that of the early phase in the formalin test. Limonin inhibited the rise of vascular permeability induced by acetic acid and the increase of paw edema induced by carrageenin. Limonin also showed inhibitory effects on bradykinin-induced paw edema and arachidonic acid-induced ear swelling. These results suggest that limonin possesses an antinociceptive effect and the effect may be accompanied by an anti-inflammatory action, and that the antinociceptive activity in Evodiae Fructus is partially attributable to limonin.

Analgesics↗
PubMed1998

Postinfarction left-ventricular aneurysm: regional stress, function, and remodeling after aneurysmectomy.

BACKGROUND: Left-ventricular (LV) aneurysm formation after myocardial infarction (MI) leads to LV remodeling with global and regional cardiac dysfunction. LV aneurysmectomy (LVA) can often improve LV function, but changes of regional wall stress and systolic function in the noninfarcted segment before and after the operation remain poorly understood. The purpose of this study was to assess the effects of LVA on regional stress and systolic function in the noninfarcted region and to examine this procedure's impact on the LV remodeling in patients with LV aneurysm after myocardial infarction (MI). METHODS: Using quantitative left ventriculography and pressure measurements, 11 patients with an anterior LV aneurysm were studied before and 8 months after standard linear repair (LVA group), and 10 patients with an anterior transmural infarction who received coronary artery bypass grafting were also studied (CABG group) in an attempt to separate the effects of aneurysmectomy from the effects of bypass surgery. Regional end-systolic (ESS) and end-diastolic (EDS) stresses of the contractile segment (CS) were computed by Janz's method. RESULTS: The total ejection fraction (EF) increased (p < 0.01) in the LVA group, whereas it did not change in the CABG group at 8 months after surgery. Both the end-diastolic and end-systolic volume indices of CS decreased (p < 0.01 and p < 0.01, respectively) in the LVA group, whereas both remained unchanged in the CABG group. The mean velocity of circumferential fiber shortening (mean Vcf) of CS increased substantially (p < 0.01) in the LVA group and, less significantly (p < 0.05), in the CABG group. Regional ESS and EDS decreased (p < 0.01 and p < 0.05, respectively) in the LVA group, whereas both remained unchanged in the CABG group. The increase in mean Vcf correlated strongly with the magnitude of decrease in ESS (r = -0.63, p < 0.01) in the LVA group but not in the CABG group. CONCLUSIONS: LVA can reduce regional afterload and improve ejection performance of the noninfarcted myocardium in many patients with a large anterior LV aneurysm and, moreover, may favorably affect the LV remodeling process after MI.

Cardiac Catheterization↗
PubMed1998

Soil factors influencing the distribution of Oncomelania quadrasi, the intermediate host of Schistosoma japonicum, on Bohol Island, Philippines.

Soil conditions essential to the survival of Oncomelania quadrasi on Bohol Island in the Philippines were examined to clarify the factors limiting distribution of the snail and to develop a method for breeding large numbers of the snail in the laboratory. Soil samples in and around snail habitats were analysed and used for breeding experiments in the laboratory. Experiments using paddy soil derived from different parent materials revealed that the numbers of juvenile snails hatched varied widely between several soil samples. The best soils for reproduction generally had a pH of 5.6-7.9 and > 200 mg of available CaO/100 g. These soil factors, in addition to shade and moisture, determine the optimum conditions for the breeding of O. quadrasi in the field as well as in the laboratory. The determination of the optimum conditions for laboratory breeding of O. quadrasi and other intermediate snail hosts should facilitate detailed study of the hosts and the development of better methods to control or eradicate schistosomiasis and other snail-transmitted diseases.

Animals↗
PubMed1998

Telemedicine in laryngology.

OBJECTIVE: The significance and usefulness of image transmission in laryngology were evaluated retrospectively on the basis of daily clinical practice. MATERIALS AND METHODS: The subjects consisted of 29 patients with laryngeal disease, whose laryngeal findings had been already recorded on videotape. Patient data were sent to a major hospital by Internet e-mail. Two laryngeal images, during breathing at rest and phonation, were transmitted as an attached file. Using a rigid or flexible endoscope coupled with a one-chip CCD camera, laryngeal images were recorded. Pictures of these laryngeal images were printed by a video printer, digitized by a compact print scanner, and saved as JPEG files. RESULTS: The diagnosis made by the three specialists in laryngology (receivers), who referred to the transmitted images and text files of the patient's history, was identical to the diagnosis made by the general otolaryngologist (sender), who referred to the original pictures and patient data. All images were displayed with sufficient quality to evaluate morphologic abnormalities, and the disturbance of cordal movements was detectable by comparing images during breathing at rest with those obtained during phonation. CONCLUSION: The image-transmitting system was a useful tool for consultation between otolaryngologists and for referrals from general practitioners to otolaryngologists.

Computer Systems↗
PubMed1998

Femoral condyle geometry in the normal and varus knee.

Femoral condyle geometry was evaluated in 30 normal and 30 varus knees using magnetic resonance imaging. In the sagittal view, the distal part of the medial condyle was deformed in the varus knees, but there was no significant difference in the posterior part of the medial condyle between the normal and varus knees. In the transverse view, the transepicondylar axis (a reliable rotational landmark) showed approximately 6 degrees external rotation relative to the posterior condylar axis in the varus knees and the normal knees. The results of this study suggest that no hypoplasia exists at the posterior part of the medial condyle in varus knees. In addition, the posterior condylar axis may be a reliable rotational landmark but is in relative internal rotation in varus knees when total knee arthroplasty is performed.

Aged↗
PubMed1998

Pulmonary disease models induced by in vivo hemagglutinating virus of Japan liposome-mediated endothelin-1 gene transfer.

Overproduction and overexpression of endothelin-1 (ET-1) have been reported to contribute to the pathophysiology of pulmonary diseases, including pulmonary fibrosis, obliterative bronchiolitis, and primary pulmonary hypertension. To determine whether ET-1 contributes to the pathogenesis of pulmonary disease, we locally overexpressed ET-1 using an in vivo UV-inactivated hemagglutinating virus of Japan (HVJ) liposome-mediated gene transfer system. Plasmid DNA of ET-1 (pME18fc preproET-1) and high mobility group 1 (HMG1) protein were co-encapsulated in liposomes. Then the plasmid DNA and liposome complexes were introduced into the lung via the trachea in Wistar rats, using HVJ-mediated membrane fusion. Control animals received instillation of HVJ liposome with an empty cassette. Two weeks after in vivo transfection of the preproET-1 gene, hyperplastic connective tissue plaques were seen in the alveolar duct and small conducting airways, indicating histologically distinctive obliterative bronchiolitis. No histopathologic changes were seen in the control animals. These results suggested that local overexpression of ET-1 may play an important role in the pathogenesis of obliterative bronchiolitis.

Animals↗
PubMed1998

Hyperechoic appearance of hepatic parenchyma on ultrasound examination of patients with blunt hepatic injury.

OBJECTIVE: To study the significance of a geographic hyperechoic liver parenchyma pattern on ultrasound (US) examination of patients with blunt abdominal injury. DESIGN: Prospective clinical study with double-blind evaluation of images and clinical data. METHODS AND MAIN RESULTS: We performed US examinations in 831 consecutive patients admitted to our hospital for blunt abdominal trauma and identified 33 with a geographic hyperechoic pattern in the liver. We correlated the appearance with computed tomographic images and with clinical, angiographic, and scintigraphic data. All patients with a geographic hyperechoic pattern showed mild computed tomographic evidence of hepatic injury (Mirvis grade 2, 69%; Mirvis grade 3, 31%). Excluding patients who required urgent surgery for other reasons and patients in shock, patients with the geographic hyperechoic pattern were managed conservatively with no complications. CONCLUSION: The geographic hyperechoic pattern of liver parenchyma on US examination of trauma patients is a mild injury that, of itself, does not require surgical therapy.

Adolescent↗
PubMed1998

Platelet and brain alpha 2-adrenoceptors and cardiovascular sensitivity to agonists in dogs suffering from endotoxic shock.

We examined the changes in alpha 2-adrenoceptor binding on platelet and brain membranes of dogs treated with a non-lethal dose of endotoxin (0.1 mg/kg intravenously), and the alpha 2-adrenoceptor mediated cardiovascular effects during endotoxin shock. At 2 h, 24 h, and 7 days after endotoxin administration, the number of binding sites (Bmax) of [3H]yohimbine binding decreased and equilibrium dissociation constants (Kd) increased in platelets, whereas both Bmax and Kd decreased in either cerebral cortex or medulla oblongata. After 30 days of endotoxin administration, there were no significant differences in Bmax or Kd between the treated and untreated animals in both platelets and brain tissues. Significant positive correlations were observed for Bmax values between platelets and brain tissues, although negative correlations for Kd values between platelets and brain were not significant. Significant negative correlations were also observed between plasma catecholamine concentrations and platelet alpha 2-adrenoceptor number, and between plasma noradrenaline and medulla alpha 2-adrenoceptor number. Pretreatment with E coli endotoxin diminished cardiovascular effects such as bradycardia, hypotension, and increase in systemic vascular resistance induced by either i.v. clonidine or xylazine. This suggests that alpha 2-adrenoceptor activity is impaired in the central nervous system as well as in the peripheral vascular system during endotoxin shock. Therefore, platelets may in part represent a good model which reflects the alpha 2-adrenoceptor changes in the central nervous system and peripheral vascular system during and after endotoxin shock.

Adrenergic alpha-2 Receptor Antagonists↗
PubMed1998

Cutaneous malakoplakia in pigs inoculated with Rhodococcus equi.

Cutaneous malakoplakia was observed in pigs inoculated intramuscularly with Rhodococcus equi strains of intermediate virulence. Macroscopically, the inoculation sites showed the indurated swelling of the skin. Histopathologically, abscess formation with histiocytic granulomatous reaction was observed. Many macrophages contained target or owl-eye shaped hematoxyphil intracytoplasmic inclusions or calcosherites (Michaelis-Gutmann bodies) of various sizes. The Michaelis-Gutmann bodies were also seen outside of the macrophages. Histochemically, most Michaelis-Gutmann bodies stained positively with the von Kossa silver method and periodic acid Schiff. Immunohistochemically, some of Michaelis-Gutmann bodies were stained by two rabbit polyclonal antibodies (rabbit anti-A5 serum and rabbit anti-ATCC 33701 serum) and a mouse monoclonal antibody (anti-20-kDa antigen monoclonal antibody). This is the first report of cutaneous malakoplakia in domestic animals, which also revealed the relationship between R. equi infection and malakoplakia immunohistochemically. This experimental swine model is useful to investigate the morphogenesis of Michaelis-Gutmann bodies in malakoplakia through chronological skin biopsies.

Actinomycetales Infections↗
PubMed1998

Recovery of blood flow and oxygen transport after temporary ischemia of rat liver.

Hepatic tissue perfusion and O2 supply after ischemia are indispensable for recovery of cellular functions, but few studies have been performed regarding the recovery of tissue blood flow and O2 transport. After 5, 15, and 30 min of ischemia of rat livers, hepatic tissue perfusion, hepatic arterial and portal blood flow, plasma PO2, and O2 transport parameters were measured. Hepatic tissue blood flow and erythrocyte velocity in the sinusoids showed biphasic recoveries after temporal ischemia for 5, 15, and 30 min. The first peak in the flow appeared at 3-4 min after the initiation of tissue perfusion, and the second peak appeared at approximately 20 min, irrespective of the ischemic period. Hepatic blood flow during the initial increase contained relatively low O2-saturated blood compared with that in the second increase. Livers that had been subjected to a prior hepatic artery ligation only showed the first peak at approximately 4 min. The first increase in hepatic blood flow corresponded to the peak in the portal venous flow, and the second increase corresponded to that of the hepatic artery. These results suggested that hepatic microcirculation after temporary hepatic ischemia showed biphasic recoveries because of different restoration patterns of the portal vein and hepatic artery.

Animals↗