Search PubMed⌕ Search

Biomedical subjects

M Miyazaki

Publications and source records attributed to M Miyazaki.

At least 595 records · Page 33Linked to original sources
PubMed1992

[Vincristine played a pivotal role in hematological remission of thrombotic thrombocytopenic purpura (T.T.P.)].

A case of thrombotic thrombocytopenic purpura (TTP), in which vincristine (VCR) administration played a pivotal role in achieving the hematological remission, is presented. A 40-year-old woman with a chief complaint of purpura was transferred for detailed examination of thrombocytopenia. The presence of hemolytic anemia, schistocytosis, febrile clinical course, renal dysfunction and neurological abnormalities made the basis of a diagnosis of TTP. Twelve courses of consecutive plasma exchange and plasma infusion, which amounted to a total of 120l of fresh frozen plasma, were performed without obvious hematological improvement. Therefore, VCR (2 mg) was infused in addition to the plasma exchange. Three days later, platelets responded remarkably. After 10 days of hematological improvement, relapse occurred. VCR was reinfused. However, the second VCR infusion alone was not able to elevate platelets. With concomitant use of significant amounts of plasma, the platelet count responded gradually. Hematological remission was obtained and has continued until now. The exact role of VCR for TTP is still unknown; however, VCR is suggested to be effective for TTP as in the case presented here.

Adult↗
PubMed1992

[Polymorphism of immunoglobulin heavy chain switch region in IgA nephropathy].

We examined the relation between IgA hyperproduction and polymorphism of the immunoglobulin heavy chain switch (S) region in patients with IgA nephropathy. The frequency of the heterozygous phenotype of IgA2 switch region was significantly increased in these patients. The patients showed a significant increase in the amount of serum IgA, IgA bearing cells and levels of proteinuria. We also compared two reports on the S region in Europe, which showed different results, and found different frequencies in the phenotype of the S region. These findings suggest that IgAN patients in various countries show heterogeneity in the S region and that this polymorphism might be associated with IgA hyperproduction and the development of proteinuria in Japanese patients.

Glomerulonephritis, IGA↗
PubMed1992

[Cell culture and its application primary culture of human hepatocytes and its application].

Difficulty in obtaining human liver specimens has made a delay in the development of methodology for isolation and primary culture of human hepatocytes compared to animal hepatocyte cultures. Recently the collagenase-liver-perfusion technique, which was developed for rat hepatocyte isolation, has been applied to prepare isolated human hepatocytes. This method greatly improved the yield and viability of hepatocytes of human liver tissues. Since then, the isolated human hepatocytes and their primary culture have been widely used for studies of hepatic metabolism, regeneration, transplantation, hepatitis B virus infection, hepatotoxins, detection of human carcinogens, hepatocarcinogenesis and so forth. These current studies were reviewed.

Cell Division↗
PubMed1992

[Effect of prostaglandin E1 derivative on labilization of liver lysosomal membrane in partial liver ischemia].

The change of liver lysosomal enzymes in tissue and serum during a reperfusion period was studied in partial liver ischemic model in rats and effect of Prostaglandin E1 (PGE1) derivative on partial liver ischemia was investigated. Partial liver ischemia was induced by clamping the branches of the vessels to the right and caudate lobes of rat liver. The clamp was released after 30 minutes of ischemia. Ischemic and nonischemic lobes of the liver were separately removed and the serum was also collected immediately and two hours after the release of the clamp. Lysosomal enzyme activities from free and bound lysosomal fraction were measured separately and the fragility index (F.I.) was calculated. PGE1 derivative was administered intraperitoneally 24, 6, 0.5 hours prior to the induction of ischemia at each dose of 0.05 microgram/kg. Pretreatment with PGE1 derivative prevented lysosomal labilization in ischemic lobe, since there was a significant decrease in F.I. of cathepsin D in the PGE1-pretreated group (preischemia; 28.3 +/- 2.4%, immediately after reperfusion; 30.3 +/- 2.5%, two hours after reperfusion; 30.3 +/- 2.5%) compared to the placebo group (immediately after reperfusion; 40.9 +/- 3.4%, two hours after reperfusion; 41.7 +/- 3.4%, p less than 0.05, p less than 0.05, p less than 0.01, respectively). Pretreatment with PGE1 derivative also significantly suppressed the increase of serum lysosomal enzyme activity. These results showed that PGE1 derivative improved liver lysosomal labilization in partial liver ischemia.

Alprostadil↗
PubMed1992

[Changes in lysosomal enzymes and cell damage of the liver in obstructive jaundiced rats].

The changes of hepatic lysosomal enzymes and the hepatic cellular damage were investigated in rats with obstructive jaundice, phospholipase A2 (PL-A2) which is a strong labilizer of lysosomal membrane was added in the lysosomal fraction of rat's liver with various concentration. The activities of cathepsin D and beta-glucuronidase those were released by PL-A2 from lysosomal fraction were measured. The values of both lysosomal enzyme activities showed positive relation to the concentration of PL-A2, and were remarkably increased in obstructive jaundiced rats than in normal rats. We also measured the activity of cathepsin D released by Triton X-100 from lysosomal fraction of normal and jaundiced rat liver. The amount of lysosomal enzyme was more increased in obstructive jaundiced liver than in normal liver. Fragility score as the indicator for lysosomal membranous fragility was calculated as the ratio of cathepsin D released by PL-A2 to that released by Triton X-100. Fragility score was more increased in obstructive jaundiced rats than in normal rats. In conclusion, these data suggest that the fragility of lysosomal membrane could be enhanced in obstructive jaundiced liver.

Animals↗
PubMed1992

[Enhancement of anti-tumor effect of adriamycin by verapamil in a intrahepatic arterial infusion in the rats].

In a intrahepatic arterial infusion, the enhancement of cytotoxicity of adriamycin (ADR) by verapamil (VER), a calcium antagonist was investigated in male Wistar rat with liver tumor of Walker 256 carcinosarcoma. The accumulation of ADR in tumor tissue at 2 hrs after a bolus intrahepatic arterial injection of ADR with VER (4 mg/kg) was 1.9-fold more than without VER. But VER did not enhance it in normal liver tissue and heart tissue. In the continuous intrahepatic arterial infusion therapy (cia) of ADR and VER (1.5 mg/kg/day) for 6 days, tumor weight and the accumulation of ADR in tumor tissue, normal liver tissue and heart tissue were assessed. Tumor weight of ADR-cia+VER-cia group was significantly less than ADR-cia group (p less than 0.05). And the accumulation of ADR in tumor tissue of ADR-cia+VER-cia group was significantly higher than ADR-cia group (p less than 0.05). But VER did not enhance it in normal tissue. The administration of VER in a intrahepatic arterial infusion is shown to be able to enhance the cytotoxicity of ADR in tumor tissue but not to enhance in normal tissue. The continuous intrahepatic arterial infusion of VER enhanced cytotoxicity of ADR at clinical dose and it suggests the clinical applicability of VER in cancer chemotherapy.

Animals↗
PubMed1992

[Deep white matter hyperintensity in the occipital lobe on T2-weighted MRI in children. II. Classification based on the signal intensity].

Twenty-seven children, who had deep white matter hyperintensity in the occipital lobe (DWMH) on T2-weighted MRI, were classified into two groups, mild and severe, based on the signal intensity. The frequency of mild DWMH, which was iso-or hyperintense relative to the gray matter but hypointense relative to cerebrospinal fluid (CSF), decreased with aging; mild DWMH might result from a delayed myelination in the central nervous system. However, the frequency of severe DWMH, which was iso-or hyperintense relative to CSF, was not related to aging and was significantly high in severely retarded children. Therefore, severe DWMH might be a new indicator of mental retardation in children.

Adolescent↗
PubMed1991

Ligand-exchange ion chromatographic determination of malic acid enantiomers in apple juice with photometric detection.

An ion chromatographic separation with photometric detection using a chiral copper(II) complex as the eluent has been developed for the resolution of enantiomers of malic acid in commercially available apple juices. The results obtained by this method were in good agreement with those by an enzymatic method with separation by high-performance liquid chromatography.

Beverages↗
PubMed1991

Apparent response of subacute sclerosing panencephalitis to intrathecal interferon alpha.

An 8-year-old boy with subacute sclerosing panencephalitis (SSPE) was treated with 1.0 to 3.0 x 10(6) IU human interferon alpha (IFN) by the intrathecal route weekly or fortnightly. Pronounced improvement of clinical and electroencephalographic findings were observed in a dose-dependent manner. Our patient raises hope that IFN can induce sustained remission in patients with SSPE.

Child↗
PubMed1991

Central sleep apnea and arterial compression of the medulla.

We report a 5-year-old with central sleep apnea associated with compression of the medulla oblongata by abnormal looping of the left vertebral artery. The magnetic resonance imaging findings raise the possibility that compression of the respiratory center by an aberrant vertebral artery might cause central sleep apnea.

Brain Diseases↗
PubMed1991

Effect of a dual-head short-stroke pump on post-column peroxyoxalate chemiluminescence detection.

A dual-head short-stroke pump has two advantages in the post-column peroxyoxalate chemiluminescence (PO-CL) detection system. The first is to increase the mixing efficiency of solutions. The second is to increase the stability of the PO-CL reaction by keeping the aryl oxalate and hydrogen peroxide solutions separate. The detection sensitivities for six polycyclic aromatic hydrocarbons (PAHs) increased in the present system by using bis(2,4-dinitrophenyl) oxalate (DNPO) or bis(2,3,4,5,6-pentafluorophenyl) oxalate (PFPO) instead of such popular aryl oxalates as bis(2,4,6-trichlorophenyl) oxalate (TCPO) and bis[2-(3,6,9-trioxadecyloxycarbonyl)-4-nitrophenyl] oxalate (TDPO). Both DNPO and PFPO increased the sensitivities by factors of 4.1-10.2 and 3.5-8.1, respectively. In addition, DNPO was more stable than PFPO in acetonitrile. These results suggest that DNPO is the most useful aryl oxalate for the sensitive PO-CL detection of PAHs.

Chromatography, High Pressure Liquid↗
PubMed1991

Extending effects of phospholipids, cholesterol, and ethanolamines on survival of adult rat hepatocytes in serum-free primary culture.

In a serum-free primary culture, membrane lipids, such as phosphatidylethanolamine, phosphatidylcholine, or cholesterol, effectively prolonged the survival of adult rat hepatocytes. These lipids effectively prevented hepatocytes from morphologic degeneration observed in control cultures, such as enlargement of cell surface, degranulation of cytoplasm, and multinucleation. The maintenance effect of phospholipid precursors, ethanolamine, or phosphoethanolamine on the primary-cultured hepatocytes was similar to that of phospholipids. These effects appear to be due to stabilization of the plasma membrane.

Animals↗
PubMed1991

Expression of liver-specific functions and secretion of a hepatocyte growth factor by a newly established rat hepatoma cell line growing in a chemically-defined serum-free medium.

A rat hepatoma cell line 3'-mRLh-2 was established from 3'-methyl-4-dimethylaminoazobenzene-induced hepatoma. Cells proliferated well in 5Fs-DM-160, a chemically-defined serum-free medium; population doubling time was 68.5 h, and modal chromosome number was 81 (21%). The cells were transplantable, and the transplanted tumors were histologically diagnosed as hepatocellular carcinoma. They were cytochemically positive for gamma-glutamyl transpeptidase. The cells possessed about 30% of tyrosine aminotransferase activity level in the rat liver, and showed 5.5 to 7.4-fold induction of this enzyme activity in response to dexamethasone. Also, the cells secreted alpha-fetoprotein, albumin, transferrin, alpha 1-acid glycoprotein, C-reactive protein, fibrinogen, complement component C3, and other five-serum proteins. Furthermore, the conditioned medium stimulated DNA synthesis in primary cultures of adult rat hepatocytes in a dose-dependent, saturable manner and in the absence of epidermal growth factor. These properties of the cell line 3'-mRLh-2 were compared with those of the popular rat hepatoma cell lines, such as H4-II-E-C3 from Reuber hepatoma H35 and HTC from Morris hepatoma 7288C.

Animals↗
PubMed1991

Comparative study on the cardio-respiratory change during prostaglandin E1-induced hypotension in the patients in the supine and prone position.

Prostaglandin E(1)-induced hypotension (25% reduction from the preadministration level in mean arterial pressure) was applied to thirteen patients. Eight patients among them were operated in the supine position (group I) and other five in the prone position (group II). The maintenance dose of PGE(1) was considerably lower in group II than in group I (0.067 micro g.kg(-1).min(-1) vs. 0.119 micro g.kg(-1).min(-1)). In group I, there was a significant increase in CI, with a significant decrease in SVRI and PVRI during PGE(1)-induced hypotension. Such a high dose of PGE(1) (0.119 micro g.kg(-1).min(-1)) was considered to have a direct dilating action on the systemic resistance bed as well as on the pulmonary vasculature. It was considered that the suppression of hypoxic pulmonary vasoconstriction could be a mechanism to increase venous admixture during PGE(1)-induced hypotension. In group II, there was no significant increase in CI, and no significant decrease in SVRI and PVRI. PGE(1)-induced hypotension can be safely applied to the anesthetized patients, but we should be careful to apply it to the patients in the prone position, because lower dose of PGE(1) can induce severe hypotension, which is not accompanied by the increase in CI as occurres in the patients in the supine position.

Journal Article↗
PubMed1991

Effect of filler content of light-cured composites on bond strength to bovine dentine.

The bonding of light-cured composites to tooth tissues is known to be disturbed by polymerization shrinkage, and polymerization shrinkage is affected by the filler content of composites. This in vitro research examined the relationship between the filler content and bond strength to dentine of light-cured composites. Experimental light-cured composite systems with filler contents of 45, 55, 65 and 75 per cent by volume were used in both bond strength to dentine and shrinkage tests. The surfaces selected as substrates were a flat surface and a box-shaped cavity prepared in bovine dentine. The lowest bond strength was obtained with the 45 per cent filler content composite in the box-shaped cavity. Bond strength increased with increasing filler content. Volumetric polymerization shrinkage decreased with increasing filler content. The polymerization shrinkage at 120 s after light curing was 5.24 per cent for the 45 per cent filler content system, 4.77 per cent for the 55 per cent, 2.14 per cent for the 65 per cent and 1.68 per cent for the 75 per cent. The correlation between bond strength and shrinkage was greater for the cavity than it was for the flat surface. This implies that bond strength in the box-shaped cavity may have been affected more by polymerization shrinkage than with the flat surface. The findings lend support to the view that filler content is one of the important factors influencing the physical properties of composites.

Acid Etching, Dental↗
PubMed1991

Effects of proteolytic enzyme inhibitors on the nasal absorption of vasopressin and an analogue.

Proteolytic enzyme inhibitors were examined as absorption enhancers for the nasal delivery of vasopressin (AVP) and desmopressin (1-d-8-DAVP) in rats. Aprotinin, soybean trypsin inhibitor, and camostat mesilate were used as enzyme inhibitors. The nasal absorption of AVP and 1-d-8-DAVP was evaluated by measuring its antidiuretic effect. Nasal administration of AVP (0.005 IU/kg) or 1-d-8-DAVP alone (2.5 ng/kg) produced a small antidiuretic effect. Coadministration with aprotinin (1000 and 10000 KIU/kg) or soybean trypsin inhibitor (1.25 and 6.25 mM) did not change the antidiuretic effect. However, coadministration with camostat mesilate (1 to 50 mM) significantly increased the antidiuretic effect and, thus, the nasal absorption of AVP and 1-d-8-DAVP. The activities of aminopeptidase, cathepsin-B, and trypsin in the nasal mucosal tissue of rats were 7 nmol/min/mg protein, 0.7 nmol/min/mg protein, and 4.6 pmol/min/mg protein, respectively. Aprotinin and soybean trypsin inhibitor inhibited only the trypsin activity, whereas camostat mesilate inhibited aminopeptidase and trypsin activities. Aprotinin (MW 6500) and soybean trypsin inhibitor (MW 8000), with relatively high molecular weights, may not permeate into the nasal mucosal tissue. In contrast, camostat mesilate is slowly absorbed (8%/hr) and could inhibit the proteolytic activity in the nasal mucosa, resulting in enhanced nasal absorption of AVP and 1-d-8-DAVP.

Administration, Intranasal↗