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Biomedical subjects

Y Matsuda

Publications and source records attributed to Y Matsuda.

At least 739 records · Page 41Linked to original sources
PubMed1991

Rat angiotensin II receptor: cDNA sequence and regulation of the gene expression.

The nucleotide and amino acid sequences for rat type I angiotensin II receptor were deduced through molecular cloning and sequence analysis of its complementary DNAs. The rat angiotensin II receptor consists of 359 amino acid residues and has a sequence similar to G protein-coupled receptors. The expression of this receptor gene was detected in the adrenal, liver and kidney by Northern blotting. Sodium deprivation positively modulated the expression of the receptor gene in the adrenal. No detectable change was observed in the expression levels of this receptor gene between spontaneously hypertensive rats and Wistar-Kyoto rats in the tissues examined including the adrenal, brain, kidney and liver. Interestingly the expression of this receptor gene was developmentally regulated.

Amino Acid Sequence↗
PubMed1991

Cloning and expression of a complementary DNA encoding a bovine adrenal angiotensin II type-1 receptor.

Angiotensin II elicits different responses which affect cardiovascular, neuronal and electrolyte transport regulation. To understand the mechanisms responsible for its various actions, the receptor for angiotensin II has long been sought, but numerous attempts to purify the receptor have been unsuccessful owing to its instability and low concentration. We report here the expression cloning of a complementary DNA encoding a bovine angiotensin II receptor to overcome these difficulties. The receptor cDNA encodes a protein of 359 amino-acid residues with a transmembrane topology similar to that of other G protein-coupled receptors. COS-7 cells transfected with the cDNA expressed specific and high-affinity binding sites for angiotensin II, angiotensin II antagonist and a non-peptide specific antagonist for type-1 receptor. Dithiothreitol inhibited ligand binding. The concentration of intracellular Ca2+ and of inositol-1,4,5-trisphosphate increased in the transfected COS-7 cells in response to angiotensin II or angiotensin III, indicating that this receptor is the type-1 receptor for angiotensin II. Northern blot analysis revealed that the messenger RNA for this receptor is expressed in bovine adrenal medulla, cortex and kidney.

Adrenal Cortex↗
PubMed1991

Mechanism of augmented left atrial pump function in myocardial infarction and essential hypertension evaluated by left atrial pressure-dimension relation.

To analyze left atrial (LA) pump function in normal subjects, in patients with essential hypertension and in patients with a healed myocardial infarction, LA dimension (aortic-root echogram) and pressure (catheter-tip manometer) were simultaneously recorded in 25 patients (8 normal subjects, 7 with hypertension and 10 with myocardial infarction). The pressure-dimension relation of the left atrium was composed of 2 loops: the A loop (expressing the pump function of the left atrium) and the V loop. LA dimension at the beginning of active LA shortening was significantly greater in hypertensive subjects (33 +/- 3 mm) and in those with myocardial infarction (32 +/- 4 mm) than in normal subjects (28 +/- 3 mm) (p less than 0.01, p less than 0.05, respectively). The area of the A loop significantly increased in subjects with hypertension (48 +/- 3 mm Hg.mm, p less than 0.01) and in subjects with myocardial infarction (29 +/- 10 mm Hg.mm, p less than 0.05), compared with normal subjects (20 +/- 8 mm Hg.mm). The mean fractional shortening velocity of the left atrium significantly increased in subjects with hypertension, compared with normal subjects and those with myocardial infarction (p less than 0.05 for both). LA peak wall tension during the LA active contraction period significantly increased with hypertension and with myocardial infarction, compared with normal subjects (p less than 0.01, p less than 0.05, respectively). The area of the A loop was directly proportional to the LA dimension at the beginning of active LA shortening (r = 0.53), p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

Microbial polysaccharide, HS-142-1, competitively and selectively inhibits ANP binding to its guanylyl cyclase-containing receptor.

During the search for ANP receptor ligands of microbial origin, we isolated a novel polysaccharide, HS-142-1, from culture broth of Aureobasidium sp. HS-142-1 inhibited [125I]-rANP binding to ANP receptor in rabbit kidney cortex membranes with an IC50 of 0.3 mu g/ml, but gave no effects on specific binding of [125I]-Endothelin nor [125I]-Angiotensin II to their respective receptors in bovine lung membranes. HS-142-1 competitively and selectively inhibited ANP binding to its guanylyl cyclase-containing receptor purified from solubilized bovine adrenocortical membranes and blocked cGMP production elicited by ANP. HS-142-1 is the first non-peptide antagonist selective for ANP functional receptor and will be a powerful tool to elucidate the physiological functions of ANP.

Adrenal Cortex↗
PubMed1991

Preparation of human manganese superoxide dismutase by tri-phase partitioning and preliminary crystallographic data.

Human liver manganese superoxide dismutase has been purified by a short procedure that includes a tri-phase partitioning step to provide materials that can be crystallized from ammonium sulfate. X-ray diffraction studies at 3 A resolution show that the crystals belong to the hexagonal space group P6(1)22 or P6(5)22, with cell dimensions a = b = 81.1 A, c = 242.2 A. Manganese superoxide dismutase levels as determined by enzymatic assay as well as by enzyme-linked immunosorbent assay indicated that considerable variations occur in different livers but the total superoxide dismutase activity (Mn superoxide dismutase plus Cu,Zn superoxide dismutase) seems to be kept at constant values.

Ammonium Sulfate↗
PubMed1991

Cardio-facio-cutaneous (CFC) syndrome: report of two patients without hyperkeratotic skin lesions.

We report on two boys with the cardio-faciocutaneous (CFC) syndrome, but without hyperkeratotic skin involvement. They showed most of the manifestations of the CFC syndrome: growth and developmental retardation, relative macrocephaly, distinct facial appearance, sparse hair, and heart defects. Their skin was not hyperkeratotic, but patient 1 had mild atopic dermatitis and keloid-like depigmented spots.

Abnormalities, Multiple↗
PubMed1991

Prediction of degree of residual stenosis in coronary thrombolysis.

In order to predict the residual stenosis in coronary thrombolysis, the factors easily obtained from clinical history--age, gender, history of angina before acute myocardial infarction (AMI), family history, hypertension, diabetes, hypercholesterolemia, smoking, and interval between onset of AMI and recanalization--were observed in 114 patients with successful coronary thrombolysis. In 55 patients with angina before AMI, 29 patients had residual stenosis greater than or equal to 75% and 26 patients had residual stenosis less than 75%. In 59 patients without angina before AMI, 15 patients had residual stenosis greater than or equal to 75%, and 44 patients had residual stenosis less than 75%. The presence or absence of angina before AMI was the main variable that discriminated the groups of residual stenosis of more or less than 75%, which was the only significant independent variable to predict the residual stenosis. These data suggest that the presence of angina pectoris before AMI is likely to be associated with a significant degree of residual stenosis after thrombolysis.

Angina Pectoris↗
PubMed1991

A case of cardiac amyloidosis presenting with symptoms of exertional syncope.

A 54-year-old man presented with symptoms of exertional syncope. Cardiac amyloidosis was diagnosed by endomyocardial biopsy. Exercise tolerance test revealed a failure of increased heart rate followed by sinus arrest, associated with syncope. Autopsy revealed amyloid deposits in the sinoatrial node.

Amyloidosis↗
PubMed1991

Effects of sublingual nitroglycerin in patients receiving transdermal nitroglycerin for coronary artery disease: prevention of cross-tolerance.

The systemic hemodynamic and coronary dilative responses to sublingual nitroglycerin were studied in patients receiving transdermal nitroglycerin. A total of 48 patients with coronary artery disease were divided into 4 groups: 12 patients receiving 1 tablet of sublingual nitroglycerin without transdermal nitroglycerin (Group 1), 12 patients receiving 1 tablet of sublingual nitroglycerin with 12-hour-daily intermittent therapy of transdermal nitroglycerin (Group 2), 12 patients receiving 1 tablet of sublingual nitroglycerin with continuous therapy of transdermal nitroglycerin with continuous therapy of transdermal nitroglycerin (Group 3), and 12 patients receiving 2 tablets of sublingual nitroglycerin with continuous therapy of transdermal nitroglycerin (Group 4). Before and during administration of sublingual nitroglycerin, aortic pressure, left ventricular pressure, and coronary artery diameter were examined at diagnostic cardiac catheterization in all patients. During sublingual nitroglycerin, the decreases of aortic systolic pressure and left ventricular end-diastolic pressure were greater in Group 1, 2, and 4 than in Group 3. Dilation of coronary arteries by sublingual nitroglycerin tended to be greater in Group 1, 2, and 4 than in Group 3. Thus, the effects of sublingual nitroglycerin for the relief of ischemia might be more prominent in patients with intermittent therapy of transdermal nitroglycerin than in those with continuous therapy. The increased dose of sublingual nitroglycerin for the relief of ischemia might be more effective in patients with continuous therapy of transdermal nitroglycerin.

Administration, Cutaneous↗
PubMed1991

Enhancement of tissue plasminogen activator production from human normal fibroblast IMR-90 cells by limitation of cell growth.

Tissue plasminogen activator (t-PA) production induced by proteose peptone from IMR-90 cells was investigated. Cells monolayered on plastic surfaces had a higher ability to produce t-PA per unit cell compared to those grown tri-dimensionally on ceramic pieces. Furthermore, confluent monolayers of the cells, which suffered contact inhibition and resulted in limited growth, were available for t-PA production. Repeated batch production with microcarriers, on which the cells were almost confluent monolayers similar to those in T-flasks, was performed. Utilization of the cells, which had limited serum in the growth phase, resulted in an increase in production. Moreover, dilution of the basal components of the medium at initiation of the production phase markedly promoted t-PA production. The volumetric productivity was stable for 30 days at 100 IU/cm3 per day. The cells were then mostly retained on microcarriers. Thus, an effective and scalable method of t-PA production by normal fibroblast cells was developed.

Cell Count↗
PubMed1991

Isolation and characterization of Chlamydomonas temperature-sensitive mutants affecting gametic differentiation under nitrogen-starved conditions.

Two conditional mutants of Chlamydomonas reinhardtii, dif-1 and dif-2, affecting gametic differentiation under conditions of nitrogen (N)-starvation, have been isolated. These mutant cell remain "vegetative" at the restrictive temperature (35 degrees C) in -N medium, as defined by assays of cell body-agglutinin and cell wall lytic enzyme activities in the soluble fractions of cell homogenates. Moreover, the mutants fail to form mating structures at the restrictive temperature, but do so at the permissive temperature (25 degrees C). Temperature-shift experiments show that mutant cells which have differentiated into gametes at 25 degrees C dedifferentiate into "vegetative" cells under N-starvation conditions after transfer to 35 degrees C, but differentiate again into gametes at 25 degrees C. Genetic analyses indicate that the dif-1 and dif-2 genes are recessive and unlinked to each other or to the mating-type locus; the dif-1 phenotype cosegregates with a conditional flagellaless phenotype expressed in both +N and -N medium at the restrictive temperature.

Chlamydomonas↗
PubMed1991

Continuous production of tissue plasminogen activator (t-PA) by human embryonic lung diploid fibroblast, IMR-90 cells, using a ceramic bed reactor.

Ceramic pieces composed of 99.5% Al2O3, 3 to 6 mm long, were found to be a good matrix for growth of the human embryonic lung diploid fibroblast, IMR-90 cells. The tissue plasminogen activator (t-PA) was secreted in DME medium containing proteose peptone as a t-PA inducer. In addition, production of t-PA was enhanced by increasing extracellular CaCl2, from 3.6 to 5.4 mM. In order to eliminate negative feed-back control caused by t-PA produced and thus raise productivity, perfusion cultivation was performed using a ceramic-packed bed column, with a recirculating vessel. The recirculating vessel was used to mix fresh medium with spent medium, and to control dissolved oxygen concentrations in the extracellular environment by stirring. In continuous production using the packed bed column with 2 kg of ceramics (phi = H = 150 mm), increasing dilution rate to 0.5 day-1 could reduce product inhibition at 3-4 x 10(5) cells/ml. Cellular productivity of 560 IU/10(6) cells/day was obtained over 40 days and corresponded to the volumetric productivity of 183 IU/ml/day.

Biotechnology↗
PubMed1991

Effect of continuous cisternal drainage on cerebral vasospasm.

The effect of continuous cisternal drainage on cerebral vasospasm was studied under strict criteria in 140 patients with ruptured intracranial aneurysms. The degree of subarachnoid haemorrhage (SAH) on the computed tomography scan was graded from I to IV. The patients were classified according to the total amount of cisternal drainage into three groups, regardless of the duration of the drainage and whether or not it was accompanied by irrigation; i.e., those with less than 500 mL (group 1: 57 cases), those with 500-3000 mL (group 2: 44 cases), and those with 3000-9500 mL (group 3: 39 cases). While correlations could be found between both clinical and SAH grades with the severity of vasospasm, closer correlation could be found in the SAH grades. In analyzing the cases with subarachnoid haemorrhage grades III-IV (severe clots), the angiographic vasospasm was less severe in groups 2 and 3 than in group 1, and the incidences of permanent symptomatic vasospasm and low-density area on computed tomography were lower in groups 2 and 3 than in group 1. Regarding the surgical outcome in cases with SAH grades III-IV, the mortality rate was lower in groups 2 and 3 (22% and 19%) than in group 1 (33%). Further, the rate of good recovery was higher in groups 2 and 3 (61% and 57%) than in group 1 (28%). However, there were no differences between groups 2 and 3 in cerebral vasospasm or in surgical outcome. As a shortcoming of continuous cisternal drainage, the need for shunt operation was higher in groups 2 and 3 than in group 1.

Adult↗
PubMed1991

In situ analysis of centromeric satellite DNA segregating in Mus species crosses.

In situ hybridization of biotin-labeled mouse major satellite DNA clone pMR196 was applied to Mus domesticus and Mus spretus chromosomes (Chr). The same karyotypes were counterstained with distamycin A-DAPI to identify AT-rich heterochromatin. Chromosomes from the laboratory mouse, C57BL/6Ros (BL/6; M. domesticus) were uniformly labeled at the centromere except for the Y, while chromosomes from the divergent Mus species M. spretus showed little or no hybridization. Differences between Mus species in copy number of the major satellite DNA sequence were used to identify chromosomes of M. domesticus and M. spretus in their F1 hybrids and to discriminate domesticus and spretus centromeres in backcross progeny. The distribution pattern of heterochromatic regions demonstrated by distamycin A-DAPI counterstaining was comparable with that of in situ hybridization with pMR196, suggesting that A-T rich heterochromatin in M. domesticus is mainly constructed by the pMR196-related sequence. The in situ technique was used to examine segregation of domesticus centromeres in backcross progeny obtained by mating F1 hybrid females with M. domesticus or M. spretus males. The segregation of centromeres did not deviate from the expected among the backcross progeny from C57BL/6Ros males, whereas chromosomes with M. domesticus centromeres were prone to appear in the progeny from backcross matings by M. spretus males.

Animals↗
PubMed1991

Assay of myosin light chain kinase activity by high-performance liquid chromatography using a synthetic peptide as substrate.

The most popular method to determine the activity of myosin light chain kinase is to measure the radioactivity incorporated from [gamma-32P]ATP into phosphoryl-accepting substrates. In this paper, we report a new method for determination of myosin light chain kinase activity without using radioisotopes. Synthetic peptides and nonradiolabeled ATP were used as substrate, and the peptide substrate was phosphorylated by myosin light chain kinase purified from chicken gizzard. After terminating the reaction, the reaction mixture was directly injected into a reversed-phase HPLC column without pretreatment, separated with the isocratic solvent system of acetonitrile-H2O-trifluoroacetic acid, and monitored at 220 nm uv absorbance. The reaction rate was determined from the peak areas of phosphorylated and unphosphorylated peptides. One chromatographic separation was achieved within 9 min, and the analysis could be repeated successively more than 100 times without washing the column. Using this method, we measured the differential inhibition of myosin light chain kinase by various inhibitors. With the aid of an automatic injector, the HPLC method with synthetic peptide enables us to handle many samples quickly and is useful for screening new myosin light chain kinase inhibitors.

Adenosine Triphosphate↗
PubMed1991

Flow cytometric DNA analysis of neuroblastoma: prognostic significance of DNA ploidy in unfavorable group.

Flow cytometric DNA content analyses were performed on samples of 54 patients with neuroblastoma. DNA aneuploidy was detected in 55.6% of the 54 patients. A high incidence of DNA aneuploidy was observed in patients with prognostically favorable variables such as age (less than 1 year), clinical stage (I, II, or IVs), and primary site (extraadrenal sites). DNA aneuploidy was predominant in surviving patients, even in those with unfavorable variables. In patients 1 year old or more, the survival rate among those with DNA aneuploidy was 58.8% compared with 28.6% in patients with diploidy. Likewise, in patients with advanced stage (III or IV) neuroblastoma, the survival rate among those with DNA aneuploidy was 63.2% compared with 30.4% in patients with DNA diploidy. It is concluded that DNA content analysis is of value in predicting the prognosis of patients with neuroblastoma.

Adrenal Gland Neoplasms↗
PubMed1991

Identification of endoprotease activity in the trans Golgi membranes of rat liver cells that specifically processes in vitro the fusion glycoprotein precursor of virulent Newcastle disease virus.

A ubiquitous host endoprotease(s) responsible for activation of the fusion glycoprotein precursor (F0) of virulent Newcastle disease virus (NDV) is an important determinant for its spreading and organ tropism in the host. To characterize the virus-activating protease (VAP), we isolated endoprotease activity from the trans Golgi membranes of rat liver cells by using F0-containing NDV particles grown in a lymphoid cell line NALM6 as substrate. The enzyme cleaved in vitro only the F0 protein of virulent NDV but not that of an avirulent strain, suggesting that it specifically recognizes pairs of basic residues at the cleavage site. Furthermore, the enzyme was found to be membrane-bound, calcium ion-dependent, and active over a broad pH range, from 6 to 8. The inhibitor spectrum of the protease together with the enzyme properties described above indicates that it is a KEX2-like enzyme. Experiments using monensin, A23187, and chloroquine indicate that the F0 cleavage of virulent NDV occurs normally in rat primary hepatocytes at or before the trans Golgi and is a calcium-dependent process. The correspondence between the characteristics of the cleavage in rat hepatocytes and those of the rat protease in vitro indicates that the endoprotease is a strong candidate for the VAP that determines the pantropic nature of virulent NDV.

Animals↗