Search PubMed⌕ Search

Biomedical subjects

M Takayama

Publications and source records attributed to M Takayama.

At least 181 records · Page 10Linked to original sources
PubMed1991

Carbachol enhances forskolin-stimulated cyclic AMP accumulation via activation of calmodulin system in human neuroblastoma SH-SY5Y cells.

We have investigated the modulatory action of carbachol on intracellular cAMP levels in human neuroblastoma SH-SY5Y cells. Carbachol enhanced forskolin-stimulated cAMP levels in a dose-dependent manner (EC50 = 3 microM). The enhancing effect of carbachol was completely inhibited by pirenzepine and atropine. Pertussis toxin treatment of the cells partially affected the ability of carbachol. Furthermore, carbachol also enhanced the effect of vasoactive intestinal peptide (EC50 = 3 microM)-, adenosine- and prostaglandin E1-stimulated cAMP levels. The enhancing response of carbachol was sensitive to trifluoperazine but insensitive to calphostin C. These results suggest that the mechanism for carbachol-induced cAMP levels may act, at least in part, through the activation of calmodulin system in SH-SY5Y cells. Hence we describe for the first time a synergistic interaction between calmodulin- and cAMP-dependent signal transduction pathway mediated by carbachol in neuron-derived cell line.

Adenosine↗
PubMed1991

Direct evidence for degradation of esperamicin A1 with thiol confirmed by fast-atom bombardment mass spectrometry.

A degradation of esperamicin A1, which is a potent antitumor antibiotic having DNA-cleaving activity, was studied by fast-atom bombardment (FAB) mass spectrometry. It was proved that the degradation easily occurs via the thiol group(s) in the matrix solution and not by a FAB-induced reaction. It was concluded that from the FAB mass spectra of all non-volatile compounds, the molecular weight should be determined by using at least two chemically different matrices.

Aminoglycosides↗
PubMed1991

Determinations of organ doses and effective dose equivalents from computed tomographic examination.

The organ or tissue doses were determined with a phantom measurement for 12 types of CT scanners widely used in Japan. Two types of thermoluminescent dosimeters were used for the dose determinations in a Rando woman phantom. The effective dose equivalents recommended by the International Commission on Radiological Protection were calculated using the measured organ or tissue doses. It was found that the CT scanners currently available give quite different organ or tissue doses. When selecting the optimum technical factors for scanning, therefore, it is important to take into consideration the balance of the image quality and the radiation exposure to patients.

Female↗
PubMed1991

[A case of mitral stenosis developing infective endocarditis 18 months after PTMC].

We presented here a case of mitral stenosis developing infective endocarditis 18 months after PTMC. A 33-year-old male was admitted to our hospital for the evaluation of mitral stenosis with signs of congestive heart failure. The use of PTMC was adequately indicated based on the data of previous cardiac catheterization and was successfully performed. The post-operative clinical course was good leaving only slight mitral regurgitation demonstrated by post-valvuloplasty LVG. About 18 months after PTMC, the patient developed a high fever and erythema with tenderness on his leg, so he was admitted again. Blood culture was positive for streptococcus viridans. Moreover, echocardiogram revealed valvular vegetation on the anterior mitral leaflet, which is the characteristic finding of infective endocarditis. Antibiotics were so effective that his clinical course was relatively good with minor cerebral infarction during chemotherapy. Little is known about the prognosis and late complication of PTMC. However, our reported case may suggest that prophylactic chemotherapy might be recommended at least in some cases showing mitral regurgitation after PTMC.

Adult↗
PubMed1991

[A study of a systemic fibrinolytic treatment of acute myocardial infarction. The effect of a moderate dose infusion of urokinase].

The clinical efficacy of intravenous fibrinolytic treatment using a moderate dose of urokinase (UK) on acute myocardial infarction (AMI) has not been well evaluated in randomized trials. In order to assess the efficacy of UK, a prospective randomized study was undertaken, aimed mainly at evaluating coronary myocardial blood flow in the infarcted myocardium using Tl-201 myocardial scintigraphy. 166 patients (131 male and 35 female, mean age 61.1 years) with AMI classified in Killip I or II who were admitted to the CCU within 24 hours of the onset of symptoms were divided into two groups; 76 patients treated with UK (UK group) and 90 patients treated with conventional therapy without UK (control group). Intravenous UK 72,000 IU was injected over 10 minutes and UK 528,000 IU was subsequently given by drip infusion over the following 12 (n = 36) or 24 hours (n = 40). There was no significant difference between the two groups with regard to the patients' background. Tl-201 uptake of infarcted myocardium in the UK group (n = 17) significantly increased in the first week compared with that on the day of admission (p less than 0.005) and a further significant increase was observed in the fourth week (p less than 0.05). In the control group (n = 10) Tl-201 uptake did not change in the first week and then increased significantly in the fourth week (p less than 0.05). Coronary angiography and left ventriculography (43 cases in the UK group and 32 cases in the control group) performed in the convalescent stage of AMI showed: 1) similar prevalence of patency of the infarct related artery (UK group: 72.1%, control group: 75.0%), 2) more prominent collateral circulation in the UK group (62.9% vs 41.4%), 3) significantly better perfusion of infarcted myocardium by coronary antegrade flow and/or collateral flow in the UK group (70.0% vs 46.9%, p less than 0.05), 4) a trend towards reduction of severe asynergy in the infarcted regional wall of the left ventricle in the UK group (16.3% vs 34.4%). The mortality rate of patients with first AMI in the UK group (n = 66) was significantly lower than that in the control group (n = 68) (4.5% vs 14.7%, p less than 0.05), and a similar trend was also found in patients with prior infarction (UK: n = 10, 0% vs control: n = 22, 13.6%).(ABSTRACT TRUNCATED AT 400 WORDS)

Aged↗
PubMed1990

Concentration of placental protein 19 in body fluid and placental tissues.

Placental protein 19 (PP19) is one of the new placental tissue proteins identified in extracts from human term placenta by Bohn and Winkler. We measured the PP19 concentration in body fluids and placental tissue by radioimmunoassay; the minimum detectable dose of standard was 1.5 ng/ml. Although ethylene diamine tetraacetic acid (EDTA-2K) inhibited the immunoreaction between PP19 (225/242) and anti-PP19 antibody (632 ZA), the PP19 concentration did not differ between serum and heparin and sodium citrate plasmas. The serum PP19 concentration was increased by hemolysis. In blood cell fractions separated by the Ficoll-Paque/Macrodex method, polymorphonuclear leukocyte fraction contained the highest PP19 concentration. The circulating serum PP19 concentration was 4.5 +/- 1.1 ng/ml (mean +/- standard deviation) in the proliferative phase (n = 8) and 5.1 +/- 1.6 ng/ml in the secretory phase (n = 7) for nonpregnant women, and 4.6 +/- 2.2 ng/ml from men (n = 12). Seminal plasma (n = 8) contained 212.2 +/- 99.7 ng/ml. The maternal serum PP19 concentration in 291 normal pregnancies increased from 6.2 ng/ml (median) at 6-7 weeks of gestation to 34.1 ng/ml at 38-39 weeks. The mean PP19 concentration was higher in amniotic fluid and retroplacental blood, but lower in umbilical cord blood than that in circulating maternal serum. In hydatidiform mole, vesicular fluid contained high PP19 concentration (1154.6 +/- 659.5 ng/ml), although these maternal serum concentration was not statistically higher than normal range. The chorionic villous trophoblast contained more PP19 than decidua, chorion, and amnion. These results suggest that PP19 has an extraplacental source, even though the chorionic villous trophoblast may be the main source throughout pregnancy.

Adult↗
PubMed1990

Angiographic response to a vasodilating drug, nicorandil, in patients with coronary artery disease.

To investigate the usefulness of nicorandil as an antianginal drug, we compared the coronary vasodilatory response in nonstenotic coronary artery segments and the hemodynamic response in 26 coronary artery disease patients. Both responses were studied prior to sublingual administration of 10 mg of this drug and 10, 30 and 60 min afterward. The plasma nicorandil concentration was determined up to 120 min after administration. The mean coronary dilating ratio of nicorandil was 117% 30 min after administration (p less than 0.01) and showed a good correlation to the plasma nicorandil concentration. The mean maximum dilating ratio of each patient was 125%. There was no difference between individual coronary arteries or between proximal and distal segments in terms of the coronary artery dilating ratio. The plasma nicorandil concentration required for 120% dilation of the coronary arteries was 26 ng/ml, 89 ng/ml and 142 ng/ml for those cases with variant angina, exertional angina and postinfarction angina, respectively. Hemodynamic changes due to administration of this drug included a decrease in blood pressure, and a reduction in total peripheral resistance, rate-pressure product, pulmonary capillary pressure and stroke-work index. These results indicate that the antianginal effects of nicorandil are derived from its coronary vasodilatory action and an inhibitory effect on myocardial oxygen consumption.

Administration, Sublingual↗
PubMed1989

Effect of intravenous streptokinase as compared with that of tissue plasminogen activator on left ventricular function after first myocardial infarction.

In a double-blind trial comparing two thrombolytic agents as treatment for acute myocardial infarction, we randomized 270 consecutive patients an average (+/- SD) of 2.5 +/- 0.6 hours after the onset of chest pain from a first myocardial infarction--135 to receive intravenous streptokinase (1.5 million units over 30 minutes) and 135 to receive intravenous recombinant tissue plasminogen activator (rt-PA) (100 mg over three hours). The primary end point was left ventricular function as assessed by cineangiography performed three weeks after infarction. The effects of the two agents on left ventricular function were similar. The ejection fraction was identical (58 +/- 12 percent) in both groups. The end-systolic volume was 61 +/- 29 ml in the streptokinase group and 66 +/- 31 ml in the rt-PA group (P not significant). Patency rates at three weeks for the infarct-related artery were also similar (75 percent in the streptokinase group and 76 percent in the rt-PA group). Reinfarction rates at 30 days were the same (5 percent) in both groups. One patient had a fatal intracerebral hemorrhage 13 hours after receiving rt-PA, and another had a fatal cerebellar hemorrhage 21 hours after receiving rt-PA for reinfarction nine days after treatment with streptokinase. An intention-to-treat analysis revealed that mortality at 30 days was 3.7 percent in the rt-PA group as compared with 7.4 percent in the streptokinase group (P greater than 0.2). Follow-up for a mean of 9.0 months revealed no significant difference in survival; we observed 12 deaths (8.9 percent) in the streptokinase group and 8 deaths (5.9 percent) in the rt-PA group (P = 0.34). We conclude that rt-PA and streptokinase, in the doses given, have similar effects on left ventricular function after a first myocardial infarction. Because of the small number of deaths, it is not possible to determine whether their effects on mortality are similar.

Double-Blind Method↗
PubMed1989

Comparative restriction endonuclease analysis of varicella-zoster virus clinical isolates.

The DNAs of 67 isolates of varicella-zoster virus (VZV) obtained from 31 individuals were compared by restriction endonuclease analysis using BamHI, EcoRI, PstI and SmaI. All of the epidemiologically unrelated 26 isolates could be differentiated using SmaI and another one or two enzymes. However, the DNA cleavage profiles of multiple VZV isolates from the same patient and the isolates from a group of patients who were infected with VZV from the same source were found to be identical to each other, as reported previously. No patients were found who were simultaneously infected with different VZV strains. Moreover, VZV showed no change in DNA fragment profiles after serial passages not only through human embryonic lung cells but also through patients.

Adult↗
PubMed1989

Comparative study of placental protein 19, human chorionic gonadotrophin and pregnancy-specific beta 1-glycoprotein as immunohistochemical markers for extravillous trophoblast in pregnancy and trophoblastic disease.

PP19, a new placental tissue protein, has alpha 1-beta 1 electrophoretic mobility, a molecular weight of 36,500 and 3.9% carbohydrate. To study immunocytochemical PP19 localization in extravillous trophoblast, we obtained formalin-fixed specimens from extravillous tubal pregnancy at gestational weeks (GW) 7-9 (12 blocks); four early intrauterine pregnancies at GW 7-13 (12 blocks); four late pregnancies at GW 28-38 complicated with intramural uterine myoma, placenta increta and abruptio placenta (8 blocks); four invasive complete moles (9 blocks); and seven primary and metastatic gestational choriocarcinomas (12 blocks). Immunohistochemical staining was done for PP19, pregnancy-specific beta 1-glycoprotein (SP1) and human chorionic gonadotrophin (hCG) using the indirect-labeled antibody method [purified PP19 (Lot no. 225/242) and antibody against PP19 (Lot no. 632ZA) prepared by H. Bohn, antibodies against hCG (Behringwerke, Marburg, FRG) and SP1 (Dakopatts, Copenhagen, Denmark)]. In both early and late intrauterine pregnancies, the extravillous syncytiotrophoblastic cell (XST) showed positive staining for hCG and SP1 in the cytoplasm, as well as for PP19, which stained more intensively in the nucleus than in the cytoplasm. The three proteins were not seen in the evtravillous cytotrophoblastic cell (XCT) in the trophoblastic cell column and shell. The interstitial cytotrophoblast-like cell (ICT), which infiltrated into the decidua and myometrium, and their blood vessels, was immunoreactively positive for PP19 but negative for hCG and SP1 with the exception of SP1-positive ICT in the myometrium in late pregnancy. XST and ICT in the endosalpinx of tubal pregnancy stained for all three proteins.(ABSTRACT TRUNCATED AT 250 WORDS)

Biomarkers↗
PubMed1989

Molecular cloning and characterization of MACIF, an inhibitor of membrane channel formation of complement.

Human erythrocytes contain a membrane protein, MACIF, which inhibits the formation of a membrane attack complex (MAC) of complement. We have cloned and sequenced the complementary DNA of MACIF messenger RNA. The amino acid sequence predicted from its nucleotide sequence consists of 128 amino acids. The amino-terminal 25 residues may correspond to a signal peptide. The carboxy-terminal sequence confirmed that MACIF is a glycosylphosphatidylinositol (GPI)-anchored protein. The amino acid sequence of MACIF was partially determined by established techniques for protein chemistry and the resultant sequence was consistent with that predicted from the nucleotide sequence. The results of sequence analyses also suggested that asparagine at the 18th position was N-glycosylated. When mRNA obtained from the MACIF cDNA clone with SP6 RNA polymerase was microinjected into Xenopus oocytes, the oocytes synthesized a product which exhibited MACIF activity and reacted with anti-MACIF antibody. Comparison of the predicted sequence revealed significant homology with mouse Ly-6 antigens.

Amino Acid Sequence↗
PubMed1989

Coronary artery-left ventricular fistulae with atrial septal defect.

We describe a 65-year-old woman who had coronary artery-left ventricular fistula associated with atrial septal defect of the sinus venosus type, and left-sided heart failure. Although a cardiac valve anomaly associated with coronary artery fistula has been described, atrial septal defect has not been reported previously in this condition.

Aged↗
PubMed1989

[A study on the abrasive resistance of titanium ion plated scaler].

There are few studies on the abrasive efficiency and the cutting quality of scalers. The author describes the characteristics of wear resistance of the scalers ion plated with TiN. Three different types of scalers were used. The first type of scalers were made of high-carbon stainless steel and here called N.T.. The second type ones were N.T. ion plated with TiN at 400 degrees C and here called Ti.400. The third type ones were ion plated N.T. with TiN at 180 degrees C and here called Ti.180. This investigation was used evaluator's scores which had done the reproducible test and the scanning electron microscope to evaluate the cutting quality of scalers. Ti.180 were divided into four groups. In Group 1, they came from manufacture. In Group 2, 3, and 4, when they were dulled under experimental conditions, they were resharpened. The results are: 1. In the reproducible test of cutting quality, there was a correlation between the cutting quality and their reproducibility. The higher was the cutting quality, the better their reproducibility was. 2. The cutting quality of Ti.400 grew duller than that of N.T. and in the SEM, the edge deformation of Ti.400 was more than that of N.T.. 3. Group 1; The cutting quality of both types of the scalers was same at 200 strokes. After 300 strokes, Ti.180 did not grow duller than N.T.. As the scaling strokes increased, the edge deformation of N.T. became more conspicuous than Ti.180 in the SEM. 4. Group 2, 3 and 4; In scaling after 200 strokes, the cutting quality of Ti.180 was sharper than N.T., and the wear facet of N.T. was extensive as compared to Ti.180.

Dental Scaling↗
PubMed1988

Characteristic differences in immunohistochemical localization of new placental proteins (PP1, PP19, PP21) in the human placenta.

The immunohistochemical localization in the human placenta of new placental proteins PP1, PP19, and PP21 was clarified using modified indirect enzyme-labeled antibody method and compared with that of pregnancy-specific beta 1-glycoprotein (SP1). The major results are as follows: positive staining for PP1 was seen at the nucleus and cytoplasm of villous cytotrophoblasts, the X cells at the basal plate, and of chorionic trophoblasts, while the decidua cells and amnion were not stained. PP19 was characteristically seen in the nucleus and cytoplasm of syncytiotrophoblasts. X cells in basal plate, chorionic trophoblasts, and maternal leukocytes. The villous cytotrophoblasts, decidua cells, and amnion were not stained. PP21 localization was found at the microvilli and basal membrane of syncytiotrophoblasts and at the cytotrophoblast plasma membrane of the chorionic villus in early gestation. In late gestation, increased staining was seen at the syncytiotrophoblast microvilli and the villous basement membrane, and moderate staining at plasma membrane of the amniotic epithelium and chorionic trophoblasts. SP1 was found only at the syncytiotrophoblast cytoplasm of chorionic villi. Studies using these four placental proteins simultaneously may therefore provide a new key learning about unknown metabolic functions of trophoblasts.

Basement Membrane↗