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T Miyazaki

Publications and source records attributed to T Miyazaki.

At least 397 records · Page 22Linked to original sources
PubMed1995

Structural analysis of alkaline-soluble polysaccharide, P-1, from the kernels of Prunus mume Sieb. et Zucc.

A polysaccharide fraction extracted with cold 0.5 M NaOH from the kernels of Prunus mume exhibited some biological activities. A polysaccharide, P-1, was purified from the 0.5M NaOH extract by ion-exchange chromatography and gel-filtration. The results of the structural analysis of P-1 to determine the relationship between the activities and the structure are described in this paper. In the mild acid hydrolysis of P-1, the nondialyzable hydrolysate (I-3) believed to be its core portion was obtained. The yield of I-3 was 26.0% and contained 59.8% uronic acid as galacturonic acid (GalA). The neutral sugars of I-3 were composed of rhamnose, xylose and galactose in a molar ratio of 1.0:3.4:0.3 following analysis by gas-liquid chromatography. The molecular weight of I-3 was estimated to be ca. 14000 by gel-filtration on Toyopearl HW55F. I-3 exhibited the mitogenic activity toward spleen cells as well as P-1. These facts appeared to confirm that I-3 was the core part of P-1 and important for its biological activity. I-3 was successfully reduced by the Taylor and Conrad method to avoid so much repetition. Methylation analysis of the reduced hydrolysate by gas-liquid chromatography and gas chromatography-mass spectroscopy showed that the ratio of 1,4-linked galactopyranosyl and 1,3,4-linked galactopyranosyl residues were significantly increased in comparison with native I-3. These results suggested that I-3 was composed of 1,4- and 1,3,4-linked galacturonic acid residues in the main chain.

Animals↗
PubMed1995

[Interaction between sodium hyaluronate and tetracyclines].

The interaction between sodium hyaluronate (HA) and 6 kinds of tetracycline (TCs) was investigated by dissolution tests, conductivity, viscosity and turbidity measurements. The 6 TCs were tetracycline (TEC), oxytetracycline (OTC), doxycycline (DOC), methacycline (METC), minocycline (MINC) and chlortetracycline (CTC). In dissolution tests, the release of TCs from the HA solution contained in the cellulose tube was measured and it was found that the 50% release time (T50) of TCs was prolonged with the increase of HA concentration. And the dependence of T50 on HA concentration was different in TCs: the release of METC was most delayed and that of OTC was least affected. By measuring the conductivity of TCs solutions, the binding of TCs to HA was suggested. In viscosity measurements of the HA solution at various pHs, the increase of viscosity was observed by the addition of METC. However in the case of OTC such an increase was not observed. The dissolution tests at various pHs were further tried and the release rate of METC depended on the pH, while that of OTC showed no dependency. Finaly, it was found that T50 of TCs from the HA solution correlates well with the literature values of apparent partition coefficients of TCs between n-octanol and aqueous buffers. Comparing T50 of 6 TCs from carboxymethylchitin (DS = 0.56) solution, it was clarified that the lipophilicity of TCs are more effective to retard the release in the case of the HA solution. From the above results, an electrostatic interaction between HA and TCs can be assumed to be almost similar among 6 TCs.(ABSTRACT TRUNCATED AT 250 WORDS)

Drug Interactions↗
PubMed1995

Two-dimensional time-of-flight magnetic resonance angiography in the coronal plane for abdominal disease: its usefulness and comparison with conventional angiography.

Using two-dimensional time-of-flight magnetic resonance angiography (2D-TOF MRA) in the coronal plane, 54 cases of arterial disease and 46 cases of venous disease were evaluated. The results were compared with those of conventional angiography to establish their relative usefulness for diagnosing abdominal diseases. Using 2D-TOF MRA, relatively large vessels such as the splenic artery, the trunks of the superior mesenteric artery (SMA) and the renal artery were clearly visualized. However, smaller vessels such as the gastroduodenal artery, main hepatic artery, branches of the SMA and the renal artery were not clearly imaged. The diameters of stenotic arteries correlated well with their images on conventional angiography (r = 0.953). In the venous system, the splenic, renal and portal veins and the first branches of the portal vein bilaterally were clearly imaged. Veins, normal or abnormal, less that 5 mm in diameter were not clearly imaged using 2D-TOF MRA. 2D-TOF MRA in the coronal plane provided useful diagnostic information, especially regarding venous diseases, tumour thrombi in the portal vein, renal vein or inferior vena cava (IVC), collateral vessels or shunts, vascular malformations, and the relationships between the portal and hepatic veins. Limitations encountered in arterial disease did not interfere with evaluations of venous disease.

Abdomen↗
PubMed1995

[Regional cerebral blood flow in status epileptics measured by single photon emission computed tomography (SPECT)].

Status epileptics (SE) due to a cerebral vascular accident can cause a change for the worse in the quality of life of patients. We have performed single photon emission computed tomography (SPECT) with 99mTc-hexamethylpropylene amineoxim (HM-PAO) to evaluate regional cerebral blood flow (rCBF) in SE caused by a cerebral vascular accident. In addition, we have discussed the neurophysiology of SE based on the SPECT findings. A total of sixteen patients (5 males and 11 females, average age; 78.2 years old) with SE who were suffering from prolonged consciousness disturbance were investigated. When SPECT was performed in the ictal state, there was a remarkable increase in Radio Isotope (RI) uptake at the focus which correlated well with EEG findings. However, in other cortical regions, basal ganglia and thalamus, there was a relatively demonstrated decrease in RI uptake compared with that of the focus. Additionally in the interictal state, we found a decrease in RI uptake in the epileptic foci and normal recovery of the RI uptake level in other cerebral regions. We speculate that these characteristic patterns of cerebral blood flow distribution shown by SPECT scans in the ictal state reflect the state of consciousness disturbance due to SE. In general, in the elderly, it is difficult to make a differential diagnosis between prolonged consciousness disturbance due to nonconvulsive SE and other diseases such as cardiovascular, dehydration, metabolic disorder, etc. Nevertheless, nonconvulsive SE causes diffuse cell loss and irreversible brain damage. Therefore the elderly who have suffered from prolonged consciousness disturbance due to SE need an exact diagnosis and immediate medical treatment. When we diagnose a nonconvulsive SE, the characteristic findings of SPECT scans in the ictal state are very clear and useful. In conclusion, SPECT is a very simple and non-invasive method that demonstrates abnormalities of brain function exactly. Therefore, we should perform not only EEG but also SPECT scans when making a diagnosis of SE.

Aged↗
PubMed1995

Increased regional systolic myocardial stiffness of the left ventricle during coronary artery occlusion in a dog: analysis of the finite element model.

(1) We measured the instantaneous systolic transfer function of an isolated canine left ventricle (LV) before and after the ligation of the left anterior descending coronary artery (LAD). The instantaneous transfer function before the ligation of the LAD showed a resonance curve whose peak frequency was 30 to 70 Hz. On the other hand, the transfer function 40 min after the ligation of the LAD showed a divided peak in the resonance curve. (2) We constructed a finite element model of a thick-walled spherical shell with a non-uniform structure. In this model, the myocardial elasticity and viscosity of the ischemic region are different from those of non-ischemic regions. One can calculate the theoretical transfer function using modal analysis and also estimate the elasticity and the viscous coefficient of both non-ischemic and ischemic myocardium by fitting the theoretical transfer function to the experimental one. (3) The estimated elasticity of the ischemic myocardium was three to five times larger than that of the non-ischemic myocardium. The estimated viscous coefficient of the ischemic myocardium was about half that of the non-ischemic myocardium. These results showed that ischemia alters the viscoelastic properties of the myocardium during systole as well as during diastole.

Animals↗
PubMed1995

Beta-adrenergic stimulation induces ST-segment elevation in dogs with healing myocardial infarction.

There is controversy with regard to the mechanism of the exercise-induced ST-segment elevation in myocardial infarction. The purpose of the present study was to investigate the mechanism of ST-segment elevation through pharmacologic interventions. Transmural anterior myocardial infarction was produced by gelatin sponge embolization of the left anterior descending artery in seven closed-chest dogs. One and four weeks after myocardial infarction, the dogs underwent the following three interventions: right atrial pacing, norepinephrine infusion (3.75, 7.5, and 15 micrograms/min) with the pacing, and methoxamine injection (2.5 and 5.0 mg) with the pacing. All dogs had transmural infarction with a mean infarct size of 12.0 +/- 4.2% of the left ventricular weight. Right atrial pacing did not induce significant changes in ST-segment. Norepinephrine induced a marked elevation of ST-segment at leads V1 to V4, while methoxamine did not. Norepinephrine induced a significant increase in left ventricular ejection fraction, while methoxamine produced a marked decrease in the ejection fraction and an increase in ventricular volume. The mean percent radial shortening of the non-infarct ventricular wall showed a significant increase with norepinephrine, but a decrease with methoxamine. In conclusion, myocardial ischemia and wall motion abnormality may be excluded as possible mechanisms of ST-segment elevation and an enhanced beta-adrenergic mechanism in the non-infarct myocardium is suggested to be responsible for ST-segment elevation.

Adrenergic beta-Agonists↗
PubMed1995

Cytokine gene expression after allogeneic bone marrow transplantation.

Cytokines produced by T lymphocytes, monocytes/macrophages, and fibroblasts play a central role in the immune response and in the development of graft-versus-host disease (GVHD). Also, it has been reported that dysregulated production of cytokines maybe the primary mediator of clinical manifestation of acute GVHD. Regarding cytokine gene expression after human allogeneic bone marrow transplantation (allo BMT), we have demonstrated increased IL-1 beta, IL-6, and TNF-alpha mRNA expression in peripheral blood mononuclear cells during the development of acute and chronic GVHD and that the degree of the increase was dependent on the severity of the disease. Furthermore, overexpression of these cytokine mRNAs could be detected before the clinical manifestations of GVHD developed. In contrast, IL-2 mRNA expression was not detected in peripheral blood mononuclear cells in GVHD patients. On the other hand, we have reported that increased mRNA expression and protein product of IL-2 and IFN-gamma were evident in the mixed lymphocyte culture of the cases who developed severe lethal transplantation-related complications. Therefore, the detection of increased IL-2 and IFN-gamma gene expression in MLC appeared to be useful for predicting transplantation-related complications in BMT patients. Furthermore, we found increased IL-2 receptor alpha subunit mRNA expression in the peripheral blood mononuclear cells during GVHD. These findings may indicate the important role of inflammatory cytokines such as IL-1 beta, IL-6 and TNF-alpha in the development of the clinical manifestation of GVHD and also may be indicative of the important role of IL-2 and the IL-2 receptor in allo response perhaps mainly as an autocrine effect.(ABSTRACT TRUNCATED AT 250 WORDS)

Bone Marrow Transplantation↗
PubMed1995

Establishment and characterization of a new Ph1-positive chronic myeloid leukemia cell line MC3 with trilineage phenotype and an altered p53 gene.

A new Ph1-positive leukemic cell line (MC3) expressing the P210bcr/abl oncoprotein was established from a patient with CML in blast crisis. The MC3 cells showed the trilineage phenotype of myeloid, lymphoid (CD19) and megakaryocytoid lineages, and had a proliferative response to rhIL-1 and rhIL-3 in the serum-free culture. These results and the expression of CD34 indicated that the MC3 cells have characteristics of hematopoietic progenitor cells. Recently, it has been documented that alterations of the p53 gene in leukemic cells are frequently detected during the blast crisis of CML. The MC3 cells contained the altered p53 gene. In addition, the original leukemic cells showed the point-mutational activation of the N-ras gene and an additional chromosomal abnormality inv(3q), but the MC3 cells contained no such abnormalities, indicating that not all of the original leukemic cells had these abnormalities. Thus, the MC3 cell line may provide several insights into investigations of the blast crisis in CML as well as hematopoietic progenitor cells.

3T3 Cells↗
PubMed1995

[Postoperative infections in cardiovascular surgery: what is an appropriate prophylactic administration of antibiotics?].

Between June 1990 and March 1993, postoperative infections developed in 19 (7.6%) of 250 consecutive patients. All patients studied underwent cardiac or major vascular operations and survived more than four postoperative days. Respiratory and wound infections were the most common infections after operation. Organisms detected were Staphylococci in 11 of which 4 were methicillin resistant, gram negative rods in 6. Factors significantly associated with an increased risk of postoperative infections by univariate analysis included age (> or = 70 years), NYHA (Grade IV), diabetes mellitus, long operating time (> or = 320 min), long perfusion time (150 min), using of IABP. The ratio of postoperative infections in patients who were given broad spectrum penicillin was higher than others. The percentage of postoperative infections was 4.4% in single antibiotic group and 13.2% in double antibiotics group, the former was significantly lower than the later. It is concluded that single dose of first or second or fourth generation cephem was strongly recommended as prophylactic antibiotics after cardiovascular surgery. Twenty adult patients received 2 g of flomoxef (FMOX) in the priming solution of cardiopulmonary bypass just before operation. Serum FMOX levels in patients developed slowly and remained at high levels, showing 49.8 micrograms/ml after five hours. It seemed that no addition of drugs were necessary during cardiopulmonary bypass within five hours.

Aged↗
PubMed1995

[A case of hepatocellular carcinoma with bone metastasis responding to oral administration of UFT].

A 63-year-old male patient with a mass in the left chest wall was referred to our hospital. An osteoclastic area was found in the mass of the left 4th rib by computed tomography; the mass was hard and little movable. There was an irregular and poorly demarcated low-density area, 5 cm in diameter, in the liver anterior superior segment. Aspiration from the mass of the chest wall indicated adenocarcinoma (class V) and forecast of metastatic lesion. The titer of serum AFP showed an extremely high level of 1,100 ng/ml. According to these findings, the patient was diagnosed as having hepatocellular carcinoma with bone metastasis and treated by the administration of oral UFT (300 mg/day). Six months later, the mass in the left chest wall was completely eliminated, the size of the hepatic lesion changed to 2.5 cm, and the titer of AFP decreased to the normal range (8.4 ng/ml). Treatment of hepatocellular carcinoma with bone metastasis is often ineffective, but this is a rare case showing the clinical effectiveness of oral administration of UFT.

Administration, Oral↗
PubMed1995

Characteristics of MHC antigen expression and tumor-infiltrating mononuclear cells in renal cell adenomas and carcinomas.

We compared the expression of major histocompatibility complex (MHC; HLA class I and II) antigens and the presence of tumor-infiltrating mononuclear cells presenting S100 protein (S100), CD68 antigen, or CD45RO antigen in formalin-fixed, paraffin-embedded tissue sections of 10 renal cell carcinomas and 9 renal cell adenomas using immunohistochemistry. The expression of beta 2-microglobulin (B2MG) as an HLA class I antigen in all 10 cases (100%) and that of HLA-DR/alpha as an HLA class II antigen in 7 of 10 cases (70%) of carcinoma was stronger than that in the adjacent proximal convoluted tubule, but was respectively not different to weaker in 8 of 9 cases and not different to markedly weaker in all cases of adenoma. Furthermore, there was comparatively dense infiltration by S100(+) antigen-presenting cells in the carcinomas, but almost none in the adenomas and generally dense infiltration by CD45RO(+) T cells and CD68(+) macrophages in the carcinomas, but little to none in the adenomas. We concluded that the generally enhanced expression of MHC antigens in carcinomas must be an immunophenotypic deviation from not only the adjacent proximal convoluted tubule but also adenomas, and that the predominant infiltration of antigen-presenting cells, T cells and macrophages in the carcinomas, but not in the adenomas, reflects the anti-cancer immune reaction.

Adenoma↗
PubMed1994

[Percutaneous transluminal angioplasty of the ilio-femoro-popliteal arteries: initial and long-term results].

The initial and long-term results of percutaneous transluminal angioplasty (PTA) were assessed in 254 atherosclerotic lesions of the ilio-femoro-popliteal arteries in 130 patients. There were 122 men and 8 women, aged 36-85 years (average, 68 years). Follow-up periods ranged from 1 to 131 months, with a mean of 42 months. PTA was performed in 6 patients in Fontaine's stage I, 112 patients in stage II, and 12 patients in stage III-IV. We reported initial success rates of 92%, 58%, 83% and 74% for iliac stenosis, occlusion, femoro-popliteal stenosis and occlusion, respectively. Overall, the initial success rate was 82% (203/247). The 5-year patency rates according to Kaplan-Meier analysis were 70%, 69% and 63% for iliac stenosis, occlusion and femoro-popliteal stenosis, respectively. In femoro-popliteal occlusion, the 1-year patency rate was 42%, which was significantly worse than that for stenosis (P < 0.01). The longest patency periods obtained were 131 months in the iliac artery, and 106 months in the femoro-popliteal artery. The recurrence rate within 6 months was significantly higher in patients with diabetes. The recurrence rate between 6 and 12 months was significantly higher in patients with poor run-off, and those of advanced age.

Adult↗
PubMed1994

Thiamine disulfide as a potent inhibitor of human immunodeficiency virus (type-1) production.

Thiol and disulfide compounds were tested as an anti-HIV drug against transactivator (Tat)-mediated transactivation of HIV-1. Of all the compounds tested, thiamine disulfide, alpha-lipoic acid, and N-acetycysteine significantly depressed HIV-1 Tat activity. Thiamine disulfide alone in these compounds possessing anti-HIV-Tat activity markedly inhibited production of progeny HIV-1 in acute and chronic HIV-1-infected CEM at nontoxic concentrations of 500-1000 microM. Thiamine disulfide (500 microM) blocked 99.7% of HIV-1 production after 96 hr culture in acute HIV-1 (LAV-1) infection (m.o.i. = 0.002), whereas it inhibited 90-98% of HIV-1 production in chronic-infected cells (CEM/LAV-1, H9/MN, and Molt-4/IIIB). The results suggest that thiamine disulfide may be important for AIDS chemotherapy.

Acetylcysteine↗
PubMed1994

Functional activation of Jak1 and Jak3 by selective association with IL-2 receptor subunits.

The interleukin-2 receptor (IL-2R) consists of three subunits: the IL-2R alpha, IL-2R beta, and IL-2R gamma chains, the last of which is also used in the receptors for IL-4, IL-7, and IL-9. Stimulation with IL-2 induces the tyrosine phosphorylation and activation of the Janus kinases Jak1 and Jak3. Jak1 and Jak3 were found to be selectively associated with the "serine-rich" region of IL-2R beta and the carboxyl-terminal region of IL-2R gamma, respectively. Both regions were necessary for IL-2 signaling. Furthermore, Jak3-negative fibroblasts expressing reconstituted IL-2R became responsive to IL-2 after the additional expression of Jak3 complementary DNA. Thus, activation of Jak1 and Jak3 may be a key event in IL-2 signaling.

Animals↗
PubMed1994

TGF beta 1 suppresses EGF-induced increase in nuclear type 1 protein phosphatase activity at the G1/S transition of hepatocyte proliferation.

Nuclear type 1 protein phosphatase (PP1) activity in primary culture of EGF-stimulated hepatocytes was significantly and transiently increased at the G1/S transition, being about 2.5-fold, while that in non-stimulated hepatocytes showed almost no change. On the other hand, non-nuclear PP1 activity was gradually increased until the G1/S transition, but the activity showed no difference between EGF-stimulated and non-stimulated hepatocytes. Under growth-inhibited conditions in the presence of TGF beta 1, the increase in nuclear PP1 activity was completely suppressed, whereas non-nuclear PP1 activity was little affected. Such close correlation between nuclear PP1 activity and growth factor-induced positive or negative growth signaling strongly suggests an involvement of PP1 in progression from G1 to S phase of hepatocytes. On Western immunoblotting using antisera for PP1 alpha, PP1 gamma 1, and PP1 delta, no isoform showed any change in amount under these conditions. Mechanism(s) of growth-associated alterations in nuclear PP1 activity is discussed.

Animals↗
PubMed1994

A potential peptide vaccine against two different strains of influenza virus isolated at intervals of about 10 years.

We have developed a strategy for making synthetic peptide vaccines, in which a peptide, HA127-133, derived from the hemagglutinin (HA) of A/Aichi/2/68(H3N2) influenza virus (Aichi/68) is introduced into the Ab binding component consisting of 43-46 and 54-58 residues of a pigeon cytochrome c analogue peptide, 46F50V54A. Indeed, this hybrid peptide, 46F/HA127-133/54A, induced impressive T-cell responses and antibody production neutralizing infectivity of Aichi/68 in vitro. In a subsequent study we found that 46F/HA127-133/54A(18mer) peptide antigen, which had been prepared by substitution at the central five residues of 46F50V54A with HA127-133, generated T-cell responses and neutralizing antibody responses as well. On the basis of these prior findings, in the present study we analyzed immunopotency of 46F/HA127-133/54A(18mer) in vivo administered in several ways to I-Ab mice. We show herein that this peptide vaccine loaded in multilamellar liposomes without adjuvant protects the mice against infection with Aichi/68 within 2 weeks after final immunization. Further, this peptide vaccine was shown to be effective in preventing infection with a naturally occurring antigenic variant, A/Texas/1/77(H3N2), carrying the same sequence at 127-133 of the HA as Aichi/68 virus. Since this part of the HA is relatively conserved among H3 subtype influenza viruses, our peptide vaccine may become the basis for a new strategy to prepare effective vaccines that will overcome the ineffectiveness of classical vaccines attributable to antigenic drift of influenza viruses.

Animals↗