Biomedical subjects

T Miyazaki

Publications and source records attributed to T Miyazaki.

At least 451 records · Page 25Linked to original sources

PubMed1994

[Sustained-release effect of the direct compressed tablet based on chitosan and Na alginate].

In the dissolution test of tablets prepared by the direct compression of chitosan with 10% sodium alginate (NaAlg), the release of theophylline was extended independently of the medium pH. The drug release mechanism of the tablet was investigated by measuring the dissolution behavior of such excipients as chitosan and NaAlg. It was shown that at the lower pH the drug release was accompanied with the dissolution of chitosan, while at the neutral pH it was controlled by the gelation and dissolution of NaAlg. Further more by the oral administration of the tablet to beagle dogs, the sustained release of theophylline was also confirmed by some bioavailability parameters. Thus the chitosan tablet with 10% NaAlg was expected to be a pH-independent sustained release dosage form.

Administration, Oral↗

PubMed1994

[Antimutagenic and bactericidal substances in the fruit body of a Basidiomycete Agaricus blazei, Jun-17].

The fruit body of a Basidiomycete Agaricus blazei, Jun-17 (Himematsutake) was extracted with hexane and chloroform-methanol (2:1, v/v), and the antimutagenic effect of the extracts was examined using an Ames/Salmonella/microsome assay. Both extracts of Agaricus inhibited the mutagenicity of benzo[a]pyrene(B[a]P). The hexane extract was purified by silica gel column chromatography and high performance liquid chromatography (HPLC), and linoleic acid was isolated as a main substance having antimutagenic activity. Fr. IIa, IIb, IIc and IIb, which reduced the number of His+ revertant colonies induced by B[a]P, were separated from the chloroform-methanol extract by silica gel column chromatography and HPLC. An antimutagenic substance in Fr. IIa was linoleic acid. From Fr. IIb, a bactericidal, not antimutagenic, substance was isolated and identified as 13-hydroxy cis-9, trans-11-octadecadienoic acid (13ZE-LOH). Antimutagenic substances in Fr. IIc and IId were not purified. The possible source and mechanism of formation of 13ZE-LOH are discussed.

Agaricus↗

PubMed1994

Exercise-induced ST-segment elevation and hemodynamic responses one month after myocardial infarction.

Changes in hemodynamics and plasma norepinephrine levels during supine bicycle exercise after myocardial infarction were measured to investigate the mechanism of exercise-induced ST-segment elevation. Seventy-eight patients were divided into groups which showed either ST elevation (STE), ST depression (STD), or no ST changes (STU). Most of the STE group had anterior myocardial infarction (90.6%) and single-vessel disease (76.7%). The STE group achieved a significantly higher workload (119.5 +/- 4.0 watts, mean +/- SEM) than the STD group (82.3 +/- 2.8, p < 0.01). Heart rate and cardiac output at maximal workload were significantly higher in the STE group (136.6 +/- 3.4 beats/min, 7.44 +/- 0.28 l/min/m2) than in the STD group (110.0 +/- 3.9, 4.83 +/- 0.36, p < 0.01). Pulmonary artery pressures were less elevated in STE than STD patients. Plasma norepinephrine levels increased significantly at maximal workload in STE patients, as compared to the other groups. In conclusion, the STE group achieved a higher exercise level associated with augmented sympathetic activity, which may be a possible mechanism of exercise-induced ST elevation after myocardial infarction.

Cardiac Output↗

PubMed1994

Transcatheter arterial embolization of obstetric and gynaecological bleeding: efficacy and clinical outcome.

32 patients with uncontrollable genital bleeding resulting from postpartum haemorrhage (n = 15) or malignant neoplasms (n = 17) were treated by arterial embolization therapy on an emergency basis. The 15 patients with postpartum haemorrhage responded dramatically to treatment by embolization. Follow-up computed tomography or magnetic resonance studies in 12 cases showed haematomas in the pelvic extraperitoneal space, but most then reduced in size or disappeared spontaneously. In two patients with large haematomas, laparotomy was required. No serious complications developed and normal menstruation resumed in the women who did not undergo hysterectomy. In the 17 patients with malignant neoplasms, bleeding was temporally controlled in all, but recurred in seven and required re-embolization in three. One patient experienced slight numbness of the leg and another had a skin ulcer. All patients underwent subsequent treatment including radiation therapy (n = 10), operation (n = 5) or chemotherapy (n = 2). We conclude that arterial embolization has significant merits in the management of patients with uncontrollable genital bleeding.

Adult↗

PubMed1994

Sequential magnetic resonance features of encephalopathy induced by systemic mastocytosis.

A 37-year-old man developed encephalopathy with prominent eosinophilia. Magnetic resonance imaging (MRI) revealed multiple T2-weighted high signal intensity lesions with dimeglumine gadopentetate (Gd-DTPA) enhancement on T1-weighted images, which were distributed in the cerebral cortex, thalamus, deep white matter and cerebellum. He was diagnosed as having systemic mastocytosis on the basis of proliferating mast cells in the bone marrow and peripheral eosinophilia. Following steroid administration, there was a rapid improvement of his symptoms and laboratory data. To our knowledge, this was the first reported case of systemic mastocytosis provoking encephalopathy with serial MRI findings.

Adult↗

PubMed1994

Resistance to cyclophosphamide-induced diabetes in transgenic NOD mice expressing I-Ak.

Transgenic expression of the MHC (major histocompatibility complex) class II I-Ak molecule was previously shown to effectively reduce the incidence of insulitis in non-obese diabetic (NOD) mice at the age of 20 weeks. We have further characterized the expression and function of the I-Ak molecule and examined its effects on the incidence of diabetes in NOD mice. The newly expressed I-Ak molecule was recognized as an alloantigen by the T lymphocytes of normal NOD mice as shown by mixed lymphocyte reaction (MLR). The levels of endogenous I-Ag7 expression on peripheral blood lymphocytes were not affected by the transgene expression. Transgenic NOD mice were completely resistant to spontaneous diabetes, but the treatment by cyclophosphamide, which effectively induces diabetes in normal NOD mice, caused diabetes, although at a much lower incidence than that of normal NOD mice. On the basis of these findings, we discuss the role of I-Ak in the prevention of diabetes in NOD mice.

Animals↗

PubMed1994

In vivo cytokine gene expression in various T cell subsets of the autoimmune MRL/Mp-lpr/lpr mouse.

We have used the reverse transcriptase polymerase chain reaction (RT-PCR) technique to assess the expression of cytokine genes in various T cell subsets of autoimmune-prone mice. Our study confirmed the previously described features in lpr mice that IFN-gamma, TNF-alpha, and TNF-beta were transcribed by various T cell subsets. We in this study demonstrated that double negative (DN) T cells, the major cell population in lpr mice, failed to express interleukin-3 (IL-3), IL-4, IL-5, and IL-6 genes that influence B cell growth and activation. In contrast, DN T cells expressed Eta-1 gene that is shown to augment polyclonal activation of B cells and immunoglobulin production. Thus, it is conceivable that T cell-derived B cell-stimulatory activities in MRL/lpr mice can be attributed to Eta-1, rather than IL-3, IL-4, IL-5 or IL-6. We also demonstrated that CD4+ T cells infiltrating into kidney tissues of MRL/lpr mice expressed various cytokine genes such as IL-1, IL-5, IL-6, IFN-gamma, TNF-alpha, TNF-beta and TGF-beta.

Animals↗

PubMed1994

[Longitudinal assessment of hematological parameters in the elderly].

Red blood cell count (RBC), hemoglobin level (Hb), hematocrit value (Ht), and white blood cell count (WBC) were determined periodically in 499 subjects (274 males, 225 females) aged 60 and over. RBC, Hb, and Ht showed a significant decrease after 5 years in both younger (60-64) and older (65 and over) male groups, and in the female groups except for the Hb level in the older group. Comparison between the younger and older group (cross-sectional study), revealed that the older male group showed lower levels of RBC, Hb, Ht than the younger male group, but the situation was completely the reverse in the females. No significant age-related changes were observed in WBC, but it was significantly higher in both the younger and older male groups than in the female groups. A significant decline with age was observed in both male and female MCV values. On the contrary, from a cross-sectional standpoint, the MCV values in the older female group were higher than those in the younger group. These findings revealed a completely reverse outcome in some parameters, when studied longitudinally and cross-sectionally. Therefore, the data should be evaluated longitudinally to elucidate the real effect of aging. It is pertinent to apply the WHO criteria (male 13 g/dl, female 12 g/dl) to the diagnosis of anemia of elderly people.

Aged↗

PubMed1994

[Very low-intensity anticoagulant therapy in elderly cardioembolic stroke patients with nonvalvular atrial fibrillation].

Several investigations revealed the significant effect of anticoagulant therapy for stroke prevention in patients with atrial fibrillation. However, in the elderly population, the optimal therapeutic strategy of secondary prevention of cardioembolic stroke is still controversial. We prospectively evaluated the efficacy and safety of very low-intensity anticoagulant therapy (target range, Thrombotest = 20-30%: INR = 1.47-1.81) for elderly cardioembolic stroke patients due to nonvalvular atrial fibrillation. Twenty cardioembolic stroke patients (average age 80.0) with nonvalvular atrial fibrillation were included in our study. Anticoagulant therapy began 5 of 7 days after the embolic event. The incidental rate of ischemic stroke recurrence and bleeding complication were evaluated. During mean follow-up of 14.7 month, the annual recurrent rate of ischemic stroke was 8.2% (cardioembolic stroke = 4.1%/year, atherothrombotic stroke = 0%/year, lacunar stroke = 4.1%/year), whereas one non-fatal gastrointestinal bleeding was observed. Our study suggested that even in the elderly population, very low-intensity anticoagulant therapy may be effective, and safe with respect to prevention of bleeding complications, for secondary cardioembolic stroke prevention.

Aged↗

PubMed1994

[Relation of gestational age, maternal body weight and age or serum alpha-fetoprotein and human chorionic gonadotropin at second-trimester].

Serum levels of alpha-fetoprotein (AFP) and human chorionic gonadotropin (hCG) were measured in serum samples of 1,964 pregnant Japanese women whose gestational age and singleton pregnancy were confirmed by ultrasound examination during the first trimester of pregnancy. Statistical analysis of log-linear regression to calculate multiples of the median (MoM) was accomplished by the SAS statistical method. The levels of the two analytes noticeably decreased as maternal body weight increased. However, maternal age did not have a significant effect on either of them. The MoM formulae were as follows: MSAFPMoM = AFP/exp(0.861 + 0.0685 x gestational age(weeks) - 0.00572 x body weight(kg)). MShCGMoM = hCG/exp(6.12 - 0.787 x gestational age(weeks) - 0.00613 x body weight(kg)). Gestational age and maternal body weight should be considered as regression functions for the adjustment of serum levels in risk estimation of fetal anomalies and fetal demise in Japan.

Adult↗

PubMed1994

[Screening for adverse perinatal outcome by biomarkers in maternal serum; a comparison of elevated maternal serum alpha-fetoprotein versus human chorionic gonadotropin].

We conducted a cohort analytic study to determine whether an unexplained increase in maternal serum alpha-fetoprotein (MSAFP) or human chorionic gonadotropin (MShCG) is effective in screening for adverse perinatal outcomes. MSAFP and MShCG levels were measured in 1,097 consecutive pregnant women in whom gestation was dated by ultrasonography and who later delivered a single infant. Patients with high MSAFP or MShCG had a much higher risk of low birth weight, intrauterine growth retardation and fetal death. But a screening test with MShCG for predicting preterm birth, low birth weight and intrauterine growth retardation had an approximately twice higher sensitivity than that with MSAFP. A combination of MSAFP and MShCG had little effect on the sensitivity. We concluded that a screening test with MShCG alone might be useful in predicting adverse perinatal outcomes.

Biomarkers↗

PubMed1994

Significance of 2',5'-oligoadenylate synthetase activity and HCV genotype in IFN therapy for type C chronic hepatitis.

Although the mechanisms of elimination of HCV by IFN have not been fully elucidated, the 2-5A system was reported to be one of the mechanisms of the anti-viral effect of IFN. Therefore, the relationship between HCV genotype, induction of 2-5AS and clinical effect was investigated. As for the anti-viral effect during IFN therapy, in type III or IV, most patients lost HCV-RNA regardless of serum 2-5AS induction even in high HCV-RNA concentration cases. In contrast, in type II, the negativity rate of HCV-RNA became high along with an increase of serum 2-5AS activity, but in patients with high HCV-RNA concentration, HCV-RNA was persistently positive. As for the long term clinical effect of IFN therapy judged 6 months after completion of IFN therapy, HCV genotypes were closely related to the effect; that is, the patients with type III or type IV HCV genotype showed a higher complete response rate compared with the patients with type II HCV genotype. However, the relationship between the long term clinical effects and induction of serum 2-5AS during IFN therapy was obscure. These results suggest that induction of 2-5AS is closely related to the anti-viral effect during IFN administration, but the viral factors appeared to be related to long term clinical effects after cessation of IFN therapy.

2',5'-Oligoadenylate Synthetase↗

PubMed1994

Cytokine gene expression by concanavalin A-stimulated peripheral mononuclear cells after bone marrow transplantation: an indicator of immunological abnormality due to chronic graft-versus-host disease.

The response of IFN-gamma, IL-2 and IL-5 mRNA expression to the stimulation of concanavalin A (Con A) in peripheral blood mononuclear cells (PBMC) after bone marrow transplantation (BMT) was analyzed using reverse-transcriptase polymerase chain reaction (RT-PCR) to assess the recovery of T cell function. The subjects were 23 patients undergoing allogeneic BMT, 1 syngeneic BMT, 1 autologous BMT and 2 normal individuals. IFN-gamma mRNA expression increased after Con A stimulation in 6 patients who had limited chronic graft versus host disease (GVHD), 14 patients who did not have chronic GVHD, each one patient receiving syngeneic and autologous BMT and 2 normal individuals. On the other hand, IFN-gamma mRNA expression was not increased by Con A stimulation in 4 patients who had extensive chronic GVHD. Also, the concentration of IFN-gamma in cultured medium in a patient with extensive chronic GVHD was not detectable. A similar low response of IL-2 and IL-5 mRNA expression to Con A was observed in these patients with extensive chronic GVHD. These findings indicate that the cytokine productive capacity of T cell (IFN-gamma and IL-2 could be produced by type 1 T helper (Th1) cells and IL-5 could be produced by type 2 T helper (Th2) cells) was suppressed in patients who had extensive chronic GVHD, while that capacity was almost normal in patients without chronic GVHD and with limited chronic GVHD. Therefore, the analysis of cytokine gene response to Con A stimulation may provide useful information regarding immune reconstitution after BMT.

Adolescent↗

PubMed1994

Hyperacute graft-versus-host disease accompanied by increased serum interleukin-6 levels.

Hyperacute graft-versus-host disease (GVHD), which progresses severely and rapidly, was observed in three patients with acute leukemia transplanted with bone marrow cells from human leukocyte antigens (HLA)-identical and mixed leukocyte reactions (MLR)-negative siblings. Hyperacute GVHD developed in these patients within 7 days after bone marrow transplantation (BMT) and was rapidly aggravated inspite of cyclosporin A (CyA) and short-term methotrexate (MTX) prophylaxis and treatment with bolus methylprednisolone (mPSL). These patients showed markedly increased serum interleukin-6 (IL-6) levels after BMT, whereas other cytokines such as interferon gamma (IFN gamma), tumor necrosis factor alpha (TNF alpha), and IL-2 were not increased compared with pretreatment levels. These findings suggest that markedly increased IL-6 levels may be related to hyperacute GVHD.

Acute Disease↗

PubMed1994

The role of Helicobacter pylori infection in the pathogenesis of gastritis.

We conducted a prospective study to evaluate the relationship between H. pylori infection and gastritis in a Japanese population. The study population consisted of 92 patients with endoscopically proven gastritis. Biopsy specimens were taken from the gastric mucosa from the corpus and antrum according to the Sydney system for the new classification of gastritis. H. pylori was histologically found in 84.3% of patients for mononuclear (MN) cell infiltration and in 88.1% of those positive for polymorphonuclear (PMN) cells. H. pylori was not found in any of nine patients without MN cell infiltration (P < 0.001), while 68.8% of patients without PMN cell infiltration were positive for H. pylori (P < 0.03). The frequency of MN cell infiltration in H. pylori-positive patients was significantly higher than that in H. pylori-negative patients (100% vs 65.4%; P < 0.001). The frequency of PMN cell infiltration in H. pylori-positive patients was also significantly higher than that in H. pylori-negative patients (54.5% vs 23.1%; P < 0.01). The incidence of MN cell infiltration in the antrum was significantly higher than that in the gastric corpus in H. pylori-positive gastritis patients (93.2% vs 65.1%; P < 0.001). The incidence of PMN cell infiltration was also higher in the antrum than in the corpus in H. pylori-positive gastritis patients, although the difference was not significant (42.0% vs 31.7%).(ABSTRACT TRUNCATED AT 250 WORDS)

Gastric Mucosa↗

PubMed1994

[Effect of isoflurane on spinal dorsal horn WDR neuronal activity in cats].

The effects of isoflurane (0.5% and 1.5%) on the spinal dorsal horn wide dynamic range (WDR) neuronal activity were studied in either spinal cord intact or spinal cord-transected cats. Extracellular activity was recorded in the dorsal horn from single WDR neurons responding to noxious and non-noxious stimuli applied to the cutaneous receptive fields on the left hind foot pads of intact or decerebrate, spinal cord transected (L1-2) cats. When bradykinin (BK) 10 micrograms was injected into the femoral artery ipsilateral to the recording site as the noxious test stimulus in the spinal cat, all of 17 WDR neurons gave excitatory responses which were not depressed by 0.5% isoflurane but were depressed significantly by 1.5%. On the other hand, when the injection of BK 10 micrograms into the femoral artery ipsilateral to the recording site was used in the intact cat, 13 of 24 WDR neurons (54%) gave excitatory responses, which were significantly depressed by 0.5% and 1.5% isoflurane, and 11 of 24 WDR neurons (46%) gave inhibitory responses, which were significantly depressed by 0.5% and 1.5% isoflurane. We have found that isoflurane reduces the excitation as well as the inhibition of dorsal horn WDR neuronal activity induced by BK injection.

Action Potentials↗

PubMed1994

[Multiple myeloma with numb chin syndrome as the initial manifestation].

The numb chin syndrome (NCS) is characterized by chin or lower lip numbness restricted to the distribution of the mental nerve (the distal trigeminal nerve). A case of multiple myeloma with polycythemia vera was diagnosed with NCS as the initial manifestation. A 73-year-old Japanese male was admitted to our hospital in April, 1993, because of paresthesia around the chin and lower lip. X-ray film showed multiple osteolytic lesions. According to serum and urine immunoelectrophoresis, lambda type Bence Jones protein was demonstrated. The bone marrow aspiration showed the normocellular marrow with 14.1% myeloma cells. He was diagnosed a suffering from multiple myeloma and was treated with melphalan and prednisolone. He is alive at present with resolution of NCS. We discussed pathogenesis, diagnosis, and treatment of NCS.

Aged↗

PubMed1994

[Evaluation of (1-3)-beta-D-glucan in aspergillosis and cryptococcosis].

(1-3)-beta-D-Glucan (beta-glucan) is a major structural component of fungi. The G test is a direct method to detect beta-glucan using fractionated (1-3)-beta-D-glucan-sensitive component, factor G, eluted from the limulus lysate. Previously, we reported that the G test is a more sensitive method than the mannan detection assay for the serological diagnosis of Candida infection. In this study, we discuss beta-glucanemia in patients with pulmonary aspergillosis and cryptococcosis. The concentration of beta-glucan was less than 10 pg/ml in 9 of 10 cases of pulmonary cryptococcosis, except for one case receiving hemodialysis (16.5 pg/ml). beta-Glucan increased in 3 cases of invasive pulmonary aspergillosis (27-937 pg/ml). Galactomannan antigen was positive in all of those cases. In 8 cases of aspergilloma, which showed fungus ball on roentgenogram, the mean concentration of beta-glucan was 67.1 +/- 92.7 pg/ml. Two of 8 cases were positive for galactomannan antigen. One of three cases of PAIC (productive aspergilloma on the inner wall of a cavity) and one case of chronic necrotizing pulmonary aspergillosis showed slightly increased levels of beta-glucan and positive results of galactomannan antigen test.

Adult↗