Biomedical subjects

H Matsuda

Publications and source records attributed to H Matsuda.

At least 973 records · Page 54Linked to original sources

PubMed1994

Myocardial protective effect and its mechanism of leukocyte-depleted reperfusion in neonatal rabbit hearts.

Thirty-six isolated blood-perfused hearts from newborn rabbits (age range, birth to 2 days) were subjected to 2 hours of cold global ischemia (15 degrees C), with an initial infusion of cold crystalloid cardioplegic solution, followed by 30 minutes of reperfusion (37 degrees C). The hearts were divided into two groups: those reperfused with whole blood (n = 18) and those reperfused with leukocyte-depleted blood (n = 18) obtained by the passage of blood through a leukocyte removal filter. At 30 minutes of reperfusion, the group of hearts reperfused with leukocyte-depleted blood showed significantly higher percentages of recovery in terms of the left ventricular developed pressure, the maximum rate of increase of left ventricular pressure, the rate pressure product, coronary sinus flow, and the adenosine triphosphate content in myocardium than did the group of hearts reperfused with whole blood. The hearts reperfused with leukocyte-depleted blood also showed significantly lower levels of malondialdehyde, chemiluminescence in the coronary sinus effluent, and counts of intracapillary neutrophils in myocardium than did the group of hearts reperfused with whole blood. The ultrastructural semiquantitative assessment in the myocardium showed that the mitochondrial and endothelial cell damages after 30 minutes of reperfusion were significantly less in the hearts reperfused with leukocyte-depleted blood than those in the hearts reperfused with whole blood.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1994

Nuclear magnetic resonance (NMR) analysis on the serum lipids of rabbits infected with Schistosoma japonicum: oxidative modifications of diene system in fatty chains.

Proton nuclear magnetic resonance (1H NMR) spectroscopy was used to characterize the oxidized products in the serum lipoprotein lipids (LPL) of rabbits infected with Schistosoma japonicum. The loss of bis-allylic and allylic methylenes proton peaks (2.7 and 2.0 p.p.m.) of unsaturated systems of the LPL and the appearance of the signals of the conjugated diene systems of hydroperoxide (5.43-6.45 p.p.m.) and epidioxide (2.45 p.p.m.) of the fatty chains of the serum demonstrated the lipids degradation associated with the Schistosoma infection.

Animals↗

PubMed1994

Comparison of benzodiazepine receptor and regional cerebral blood flow imaging of epileptiform foci in hippocampal kindled rabbits: a preliminary report.

To clarify experimentally which of benzodiazepine (BZ) receptor or regional cerebral blood flow (rCBF) imaging is more sensitive in the detection of epileptic foci, we simultaneously examined the BZ receptor and rCBF distribution changes in hippocampal kindled rabbits with in vivo double tracer autoradiography using 125I-labeled Ro 16-0154 (125I-Iomazenil) and 99mTc-labeled hexamethyl-propyleneamine oxime (99mTc-HMPAO). In visual analysis of brain slices extracted after the intravenous injection of the double tracer following the kindling completion, 125I-Iomazenil accumulation was more markedly and extensively decreased in the kindled right CA1 region mimicking a primary epileptic focus than 99mTc-HMPAO accumulation. Further, this decrease in 125I-Iomazenil accumulation was not due to neuropathological abnormalities which consisted only of tissue damage corresponding to electrode track in the right CA1. These results suggest that BZ receptor imaging is more sensitive in the detection of epileptic foci than rCBF imaging and, therefore, that BZ receptor imaging is useful in clinical epilepsy.

Animals↗

PubMed1994

Thyroglobulin antibodies in type 1 diabetic patients and their relatives--measurement with highly sensitive assay.

Autoimmunity in Type 1 (insulin-dependent) diabetes mellitus was assessed by measuring thyroglobulin antibodies (TGA) using a highly sensitive enzyme immunoassay in 65 young patients with Type 1 diabetes mellitus, 83 healthy first-degree relatives of the patients, 37 healthy control subjects and 67 healthy parents of the control subjects. TGA were found in 78.5% (51/65) of patients and were significantly more frequent in patients than in control subjects (40.5%, 15/37; P < 0.01). The prevalence of TGA in patients showed no correlation with age at onset, duration of diabetes or sex. Among the first-degree relatives the prevalence of TGA was significantly increased in mothers of patients than in mothers of the control subjects (80.0% vs. 54.3%, P < 0.05), while not significantly between fathers of patients and fathers of control subjects or between siblings of patients and control subjects. Comparing the TGA levels of TGA-positive subjects, the TGA levels in patients, their parents and their siblings were significantly higher than those in the corresponding control subjects (P < 0.05, P < 0.05 and P < 0.01, respectively). In the present study we thus more clearly demonstrated autoimmune diathesis in patients with Type 1 diabetes and in their first-degree relatives.

Adolescent↗

PubMed1994

Effects of washing with a neutralizing agent on alkaline skin injuries in an experimental model.

In this report a skin alkaline injury model was constructed using experimental rats and 2 N NaOH. We observed the effects of washing with a neutralizing agent on the subcutaneous tissue pH at 1, 10 and 30 min after injury and compared it with water-washing groups. In comparison with the water washing group, the peak pH values following the use of the neutralizing agent were significantly higher in the 1-min washing group, and significantly lower in the 10-min and 30-min washing groups. Changes in the pH values of the subcutaneous tissue after reaching a peak showed a similar course in the 1-min washing group, whereas in the 10 and 30 min washing groups there was a significantly different rate of decrease of pH. These results indicate that although treatment with a neutralizing agent directly after injury causes harmful effects due to the neutralizing reaction with a highly concentrated alkali. Subsequently with prolonged washing there is an effective reduction of the high pH.

Animals↗

PubMed1994

Effect of mitral valve surgery on severely impaired pulmonary function.

To evaluate the effect of surgery on severely impaired pulmonary function associated with mitral valve disease, we examined the relationship between postoperative improvements in pulmonary function and pulmonary circulation in 238 patients who underwent mitral valve surgery. Of these patients 17 met the preoperative criteria for severely impaired pulmonary function: forced expiratory volume in 1 second = FEV1 < or = 1000 ml. They showed average values for vital capacity (VC) of 1343 +/- 203 ml, for % of vital capacity for predicted values (%VC) of 52.0 +/- 6.5%, and for FEV1 of 851 +/- 104 ml. Moderate elevations of mean pulmonary arterial pressure (PAP: 36.2 +/- 10.2 mmHg), mean pulmonary arterial wedge pressure (PAWP: 23.0 +/- 9.6 mmHg), and pulmonary vascular resistance (PVR: 329 +/- 147 dyne.sec.cm-5) were also observed. Postoperatively, 4 of the 17 patients required long-term respiratory support for more than one week, and 3 patients died in hospital; this mortality rate, however, was not significantly different to that of patients with preoperative FEV1 > 1000 ml. In long-surviving patients, pulmonary function improved in the late postoperative period. Significant relationships were recognized between delta FEV1 (delta: postoperative value--preoperative value) and delta PAP, delta PAWP, and delta PVR. The delta VC and delta %VC also correlated significantly with delta PAP, delta PAWP and delta PVR. In conclusion, in patients with mitral valve disease impaired pulmonary function cannot be used to exclude patients from operation. Furthermore, severely impaired pulmonary function should improve with the improvement of pulmonary circulation after surgery.

Adult↗

PubMed1994

fastDNAmL: a tool for construction of phylogenetic trees of DNA sequences using maximum likelihood.

We have developed a new tool, called fastDNAml, for constructing phylogenetic trees from DNA sequences. The program can be run on a wide variety of computers ranging from Unix workstations to massively parallel systems, and is available from the Ribosomal Database Project (RDP) by anonymous FTP. Our program uses a maximum likelihood approach and is based on version 3.3 of Felsenstein's dnaml program. Several enhancements, including algorithmic changes, significantly improve performance and reduce memory usage, making it feasible to construct even very large trees. Trees containing 40-100 taxa have been easily generated, and phylogenetic estimates are possible even when hundreds of sequences exist. We are currently using the tool to construct a phylogenetic tree based on 473 small subunit rRNA sequences from prokaryotes.

Algorithms↗

PubMed1994

Demonstration of the target molecule of a protective IgE antibody in secretory glands of Schistosoma japonicum larvae.

We have demonstrated that a mouse monoclonal IgE antibody, SJ18 epsilon.1, recognizes a 97 kDa surface molecule (Sj97) of Schistosoma japonicum larvae and that the antibody induces partial but significant protection against the skin to lung-stage of S. japonicum infection. The antibody stimulates eosinophil- and macrophage-mediated killing of schistosomula in vitro. In the present study, we isolated the putative full-length cDNA of Sj97 by screening a lambda gt11 cDNA library from S. japonicum adult worms with SJ18 epsilon.1. The predicted amino acid sequence of the cDNA showed highly significant homology to that of S. mansoni paramyosin, a potential vaccine candidate for schistosomiasis. The deletion mutants of S. japonicum paramyosin were expressed in Escherichia coli and the translation product of 443 amino acid residues of paramyosin was found to be recognized by the antibody. Moreover, we observed by immunoelectron microscopy the presence of paramyosin in the post-acetabular gland as well as in the tegument and muscle layers of the larvae. These results suggest that paramyosin is a secretory protein which may be incorporated into the tegument during the development of schistosomula, thus becoming a target for protective immunity during the migratory phase of the parasite.

Amino Acid Sequence↗

PubMed1994

Comparative study of auricular dimensions for the normal auricles of microtia patients, their parents, and normal individuals.

We measured the dimensions of the normal auricle in microtia patients and those of both auricles in their parents, and compared the findings with data obtained in normal individuals. The physiognomical auricular length and width dimensions of the normal auricles in microtia patients were significantly smaller than those in normal individuals. The auricular length of the parents of microtia patients was also significantly smaller than in normal individuals. The auricles of the parents on the same side as those affected by microtia in the patients tended to be smaller than those on the contralateral side.

Adolescent↗

PubMed1994

Time limits for intestinal ischemia and congestion: an experimental study in rats.

We investigated to determine the time limits for intestinal ischemia and congestion. The experimental models were produced by clamping both ends and the intended feeder vessels of an approximately 1-cm length of rat jejunum. The results showed that in arteriovenous occlusion, the time required for the recovery rate to reach 50% was 7.03 hours. The time required for the recovery rate to reach 50% was 6.81 hours when arterial occlusion alone was performed and 3.70 hours when venous occlusion alone was performed. The difference between the two was statistically significant (p < 0.01). Consequently, it was found that the degree of intestinal damage due to venous occlusion was greater than the damage resulting from arteriovenous and arterial occlusion.

Animals↗

PubMed1994

Intestinal tissue pH monitoring in microsurgery: an experimental study in rats.

We monitored the pH of ischemic intestine in rats to determine whether such measurements were a useful method of postoperative monitoring. Measurement of intestinal pH was found to be useful in detecting vascular occlusion, in distinguishing arterial from venous occlusion, and in estimating the time of occlusion. This method of monitoring can be recommended after free intestinal grafting.

Animals↗

PubMed1994

Brain perfusion SPECT in a patient with a subtle venous angioma.

Brain SPECT of regional cerebral blood flow using I-123 IMP demonstrated a focally decreased perfusion area immediately adjacent to a venous angioma in a patient with simple partial seizures. A positive correlation was obtained among the location of the venous angioma, the decreased perfusion area on SPECT images, and the electroencephalographic focus. Anomalous venous drainage through a venous angioma may explain a perfusion disturbance in the surrounding brain of the angioma. High-resolution SPECT imaging with magnetic resonance guidance provides useful information on the pathophysiology of venous angiomas.

Adult↗

PubMed1994

Enzyme release from mitochondria during reoxygenation of rat liver.

Reoxygenation-induced release of mitochondrial aspartate aminotransferase (mAST) into the cytosol was studied using perfused rat liver. As the absolute activity of mAST in the perfusate did not indicate the degree of mitochondrial enzyme release, the following 3 methods were applied: measurement of the mAST to total AST ratio in the efferent perfusate, the digitonin infusion method, and measurement of mAST activity in the cytosolic compartment isolated from perfused livers. The results by all 3 methods were consistent and showed that mitochondrial injury occurs on reoxygenation. The mitochondrial Ca2+ content was proportional to the extent of mAST release during reoxygenation, indicating involvement of Ca2+ in the enzyme release. CsA, a potent inhibitor of Ca(2+)-induced increase in permeability of the mitochondrial membrane, completely prevented mAST release on reoxygenation. We conclude that during reoxygenation of hypoxic liver, mAST leaks into the cytosol in a Ca(2+)-dependent, CsA-sensitive manner.

Animals↗

PubMed1994

Role of CD4+ T cells in the rat to mouse cardiac xenotransplantation.

T cell subsets involved in rejection of xenografts were analyzed using a rat to mouse cardiac xenotransplant model. Proliferating response and interleulin-2 (IL-2) production in recipients' spleen cells were almost completely abrogated by elimination of L3T4+ T cells, but not by elimination of Lyt2.1+ T cells. Cytotoxic T lymphocyte (CTL) activities were mediated by both L3T4+ and Lyt2.1+ T cells with the help of IL-2-producing L3T4+ T cells. Administration of anti-L3T4 monoclonal antibody (mAb) into recipient mice resulted in a significant prolongation of graft survival (mean graft survival was 29.2 days). Moreover, anti-L3T4 mAb treatment plus thymectomy led to indefinite graft survival. Anti-rat endothelial cell (EC) antibody production in the grafted mice was remarkably suppressed by anti-L3T4 mAb treatment. In contrast, Lyt2.1 mAb treatment did not prolong the graft survival and did not suppress anti-EC antibody production. These results indicated the absolute requirement of L3T4+ T cells in the rejection of rat to mouse cardiac xenografts.

Animals↗

PubMed1994

Actions of peroxovanadate or tungstate on glucose transport by isolated rat adipocytes.

The effects of peroxovanadate or tungstate on 3-O-methylglucose uptake were characterized using isolated rat adipocytes to elucidate the mechanism(s) of their actions. The stimulatory effect of peroxovanadate was observed from 1 mumol/L and reached the maximum at about 100 mumol/L. The concentration showing the half-maximal effect was approximately 16 mumol/L. The maximal response of peroxovanadate was 1.19 times higher than that of insulin significantly (P < 0.01). On the other hand, the stimulatory effect of tungstate was seen only at the higher concentrations of 10-30 mmol/L. Judging from the experiments using different tungsten compounds, tungstic acid (WO4(2-)) appeared responsible for the effect. The effects of 20 mmol/L tungstate and 20 nmol/L insulin were not additive. The stimulatory effects of 1 mmol/L peroxovanadate, 20 mmol/L tungstate or 20 nmol/L insulin were not seen in the adipocytes deprived of ATP by exposure to 2 mmol/L KCN. The adipocytes which had been stimulated with insulin and further exposed to 2 mmol/L KCN were used to test whether or not peroxovanadate works directly on the function of glucose transporters. In such cells on which GLUT4-rich transporters were rendered immobile, the effect of peroxovanadate was not observed. These results indicate that the effects of peroxovanadate or tungstate are ATP or energy dependent and may be exerted through the mechanism analogous to that of insulin action, and suggest that peroxovanadate does not directly activate the function of GLUT4.

Adipocytes↗

PubMed1994

An extrapancreatic action of diazoxide to inhibit glucose transport activity on adipocytes.

The effect of diazoxide on 3-O-methylglucose (3-O-MG) transport was studied in isolated rat adipocytes to elucidate its extrapancreatic action. Diazoxide (0.3-3 mmol/L) significantly inhibited 3-O-MG uptake into adipocytes in a basal state or an insulin-stimulated state. The inhibitory effect was mainly due to the inhibition of insulin responsiveness for 3-O-MG uptake. The insulin responsiveness is determined by the capacity in the process of insulin action and in the final glucose transport activity, and diazoxide mainly inhibited the 3-O-MG transport activity itself. Based on these findings, this extrapancreatic action of diazoxide is considered to contribute partially to raising the blood glucose level in children receiving the drug. Diazoxide, as a glucose transport inhibitor, may be a useful tool for studying the issues related to glucose transport or insulin action.

3-O-Methylglucose↗

PubMed1994

A case of Kabuki make-up syndrome with central diabetes insipidus and growth hormone neurosecretory dysfunction.

A case of a 6 year old boy with Kabuki make-up syndrome with central diabetes insipidus and growth hormone neurosecretory dysfunction is reported. Magnetic resonance imaging revealed abnormal findings of the pituitary gland and stalk. Good catch-up growth was obtained by treatment with growth hormone. These findings suggest that hypothalamic-pituitary dysfunction might be involved in Kabuki make-up syndrome.

Abnormalities, Multiple↗

PubMed1994

Inhibitory effects of diazoxide or polymyxin B on glucose transport by isolated rat erythrocytes or adipocytes.

The inhibitory effects of diazoxide or polymyxin B on 3-O-methylglucose uptake were studied in isolated rat erythrocytes or adipocytes to elucidate the mechanisms of the actions of these agents. One to three mmol/L diazoxide significantly inhibited 3-O-methylglucose uptake into erythrocytes by 11-33% without altering the equilibrium space, while 0.3 mmol/L diazoxide did not. The inhibitory effect was exerted in a dose-dependent manner in this concentration range. To test whether polymyxin B affects the process of insulin action or the glucose transport activity recruited by insulin, adipocytes prestimulated with insulin and exposed to 2 mmol/L potassium cyanide (KCN) were employed since the cells, on which glucose transporters recruited by insulin were located quiescently, were useful to estimate the effect of an agent on glucose transport activity per se. Polymyxin B (100 micrograms/mL) inhibited the insulin-stimulated uptake activity in this transport system by 22.5% while it inhibited the insulin-stimulated uptake activity in intact adipocytes which were not exposed to KCN by 32.2%. These results suggest that diazoxide inhibits the function of the erythrocyte glucose transporter, GLUT1 (classified by Bell et al.), and indicate that the inhibition of the glucose transport activity recruited by insulin is the major effect of polymyxin B (100 micrograms/mL) and the inhibition of the process of insulin action is rather small.

3-O-Methylglucose↗