Biomedical subjects

H Murakami

Publications and source records attributed to H Murakami.

At least 631 records · Page 35Linked to original sources

PubMed1989

[Behavioral pharmacological properties of propiverine hydrochloride (P-4) in mice and rats].

Since propiverine hydrochloride (P-4), an anti-pollakiuria drug, increased the spontaneous motor activity of mice in general pharmacological experiments, behavioral pharmacological effects of P-4 were further studied by experiments for spontaneous motor activity, convulsion-inducing effect, and differential reinforcement of low rate (DRL) schedule in mice and rats. A high dose of P-4 (100 mg/kg, p.o.) increased slightly but significantly the spontaneous motor activity level in rats. P-4 (10, 20, and 50 mg/kg, p.o. for one week) did not affect the activity level in mice, whereas methamphetamine caused the reverse tolerance after being daily administered for one week at a dose of 1 mg/kg, s.c. P-4 (20, 50, and 100 mg/kg, p.o.) did not induce convulsive behaviors such as minimal full seisure (M.F.S.), clonic convulsion (C.C.) and tonic convulsion (T.C.) in combination with a dose (40 mg/kg, i.p.) of pentylenetetrazol, which is below the threshold in mice, whereas methamphetamine (8 mg/kg, s.c.) in combination with pentylenetetrazol induced M.F.S. Under a DRL schedule for food reinforcement in rats, P-4 (50 and 100 mg/kg, p.o.) lowered the reinforcement rate, but it did not affect other parameters. On the other hand, methamphetamine (0.5, 1, and 2 mg/kg, s.c.) facilitated DRL responses and lowered the reinforcement rate, mean of inter-response time, efficiency, respectively, in a dose-dependent manner. These results suggest that P-4 does not possess the methamphetamine-like CNS stimulating effect.

Animals↗

PubMed1988

Monoclonal antibody detection of prolactin-binding subunits in the rabbit mammary gland.

The structure of prolactin (PRL) receptor in the rabbit mammary gland was examined using a receptor-specific monoclonal antibody (MAb). The PRL receptor preparation used was purified by making use of a PRL-affinity column. MAb inhibited the binding of PRL to the receptor, in a dose-dependent manner and completely at a high concentration. Using the receptor directly labelled by 125I, the preparation was incubated with MAbs and the immune complex was collected by Pansorbin and examined by SDS/polyacrylamide-gel electrophoresis. The autoradiography showed that three species with apparent Mr values of 77,000, 41,000 and 25,000 specifically reacted with MAbs. The pattern changed little in the presence or absence of dithiothreitol. Western blot analysis showed that two species (Mr 77,000 and 41,000) reacted with MAb. Affinity labelling of the receptor with labelled PRL revealed three bands with Mr values of 96,000, 60,000 and 43,000 on SDS gels. The high-Mr complex (Mr greater than 200,000) was always present at the top of the gel. These results show that the mammary gland contains at least three PRL-binding subunits. The differences in Mr before and after PRL binding were close to the Mr of PRL. This would suggest that each PRL binding subunit reacts with one PRL molecule.

Animals↗

PubMed1988

Ultrastructure of myeloma cells in patients with common acute lymphoblastic leukemia antigen (CALLA)-positive myeloma.

We investigated the ultrastructure of myeloma cells obtained from four cases of common acute lymphoblastic leukemia antigen (CALLA)-positive myeloma. Clinically, the disease was aggressive and our patients died with a median survival after diagnosis of only 62 days. By light microscopic criteria of Greipp et al., their disease was classified as plasmablastic, immature (two cases), and intermediate. In contrast, the myeloma cells of all four cases were judged to be immature and abnormal on the basis of the electron microscopic observation. Characteristic features were sparse heterochromatin, high to moderate nucleocytoplasmic ratio, nuclear bodies, thin and short rough endoplasmic reticula, scattered pattern of mitochondria, and polysomes consisting of five to six ribosomes, along with irregular nuclear membrane, poorly developed organella, and abnormalities in cytoplasmic structures such as dense bodies, vacuoli, buddings, single-sac loop-like structures, multilamellar bodies, and abnormal inclusion bodies. While overlapping each other, it is suggested that the CALLA-positive and the plasmablastic myelomas should be classified separately. Thus, the electron microscopic study, like the immunological marker analysis, provides a useful means for better assessment regarding immaturity and abnormality of myeloma cells.

Adult↗

PubMed1988

Inhibition by endothelial cells of platelet aggregating activity of thrombin--role of thrombomodulin.

Cultured human umbilical vein endothelial cells inhibited the platelet aggregating activity of thrombin in the absence of plasma. Using a new method in which thrombin-induced platelet aggregation was measured in the presence of endothelial cells, we showed that aspirin-treated endothelial cells inhibited platelet aggregating activity of thrombin in an incubation time- and cell number-dependent manner. This inhibitory effect of endothelial cells was partially blocked by the pretreatment of endothelial cells with monoclonal anti-thrombomodulin IgG (anti-TMIgG). It is suggested that (1) endothelial cells play a role in the clearance of thrombin by binding and inactivating this enzyme and that (2) thrombomodulin on endothelial cells, apart from its role for protein C activation, may be involved in this endothelial function.

Aspirin↗

PubMed1988

Immunohistological characterization of human monoclonal antibody against lung cancer.

Using immunoperoxidase staining method, a human monoclonal antibody (MAb), termed HB4C5, which was generated by fusion of NAT-30 cells with regional lymph node lymphocytes from a lung cancer patient, was examined for tumor specificity. The determinant recognized by HB4C5 MAb was well preserved in usual formalin-fixed paraffin-embedded tissue sections. Experiments with four major histological types of the lung cancer showed that HB4C5 MAb reacted with adenocarcinoma (19/27), squamous cell carcinoma (2/15), and large cell carcinoma (4/6), but not with small cell carcinoma (0/7). The immunoreaction was seen in the cytoplasm. In addition, this MAb also reacted with some gastric and colon adenocarcinomas. Further study on normal lung and nonpulmonary tissues revealed that HB4C5 MAb bound only type II pneumocytes and proximal tubules of normal kidney.

Adenocarcinoma↗

PubMed1988

Nucleotide sequence of the cybB gene encoding cytochrome b561 in Escherichia coli K12.

The complete nucleotide sequence of the Escherichia coli cybB gene for diheme cytochrome b561 and its flanking region was determined. The cybB gene comprises 525 nucleotides and encodes a 175 amino acid polypeptide with a molecular weight of 20,160. From its deduced amino acid sequence, cytochrome b561 is predicted to be very hydrophobic (polarity 33.7%) and to have three membrane spanning regions. Histidines, canonical ligand residues for protohemes, are localized in these regions, and the heme pockets are thought to be in the cytoplasmic membrane. No significant homology of the primary structure of cytochrome b561 with those of other bacterial b-type cytochromes was observed.

Amino Acid Sequence↗

PubMed1988

Algal phycocyanins promote growth of human cells in culture.

The growth-promoting substances in a non-dialyzable extract of Synechococcus elongatus var. on RPMI 8226 cells (a human myeloma cell line) were separated by gel filtration and ion exchange chromatography. By gel filtration with Sepharose 4B, the dialyzate was separated into two fractions. One fraction was green-colored (P-1) and the other was blue-colored (P-2). The P-2 fraction had a higher growth-promoting activity than P-1. By ion exchange chromatography, the P-2 fraction was separated into two blue-colored fractions of phycocyanin and allophycocyanin. Both biliproteins promoted the growth of RPMI 8226 cells; however, allophycocyanin was more active than phycocyanin.

Cell Division↗

PubMed1988

Production of human-human hybridomas secreting monoclonal antibodies reactive to breast cancer cell lines.

We produced human-human hybridomas by fusing lymph node lymphocytes of breast cancer patients with a fusion partner, HO-323 cells, in the presence of 50% polyethylene glycol, and screened hybridomas producing monoclonal antibody (MoAb) reactive to a breast cancer cell line, MCF-7. Among 11 hybridomas secreting IgM reactive to MCF-7, four hybridomas (H15A3, H15F2, K15B4, and K15C3) produced IgM reacting specifically to breast cancer cell lines (MCF-7 and HBC-5). Among them, H15A3 proliferated in a serum-free (RDF) medium supplemented with insulin, transferrin, ethanolamine, selenium, and endothelial cell growth supplement, as fast as in 10% FCS-RDF medium. According to transfer blotting analysis, the H15F2 MoAb reacted with a 40,000 dalton antigen in MCF-7 cells.

Antibodies, Monoclonal↗

PubMed1988

Human hybrid immunoglobulin M containing immunoglobulin A.

Some hybridoma clones made by fusion of a human lymphoblastoid cell line, HO323 with human B lymphocytes, secreted not only IgA but also IgM-like immunoglobulin molecules. The IgM-like immunoglobulin had a molecular size of 900 K which corresponded to that of IgM. Immunochemical analyses revealed that the IgM-like immunoglobulin contained two monomeric IgA and three monomeric IgM molecules. In the IgA moieties, half of original light chains were replaced with kappa chains derived from the IgM, and vice versa.

Cell Line↗

PubMed1988

A compact and inexpensive device using an electronic calculator for measuring ambulatory activity in mice.

A device for measuring ambulatory activity in mice was developed. The device consisted of a plastic case, a bed plate, a step board (as a detector) and a calculator (as a recorder). A 2.2 cm width section was cut out from the middle of the case bottom in the direction of the minor axis and a step board, a width of 2 cm, was placed in the opening. A short bolt was screwed into one end of the step board and the head of the bolt was placed on the equal key of the calculator. The calculator counted the number of times the mouse stood on the step board. The validity of the device was demonstrated by measuring the effect of methamphetamine (1-4 mg/kg) on the ambulatory activity in mice.

Animals↗

PubMed1988

70-kD heat shock-related protein is one of at least two distinct cytosolic factors stimulating protein import into mitochondria.

We have developed an in vitro system in which the posttranslational import of Put2 (delta-pyrroline-5-carboxylate dehydrogenase), into yeast mitochondria is dependent on the addition of yeast postribosomal supernatant (PRS). When mRNA for a nuclear-encoded yeast mitochondrial matrix protein, Put2, was translated in a wheat germ cell-free system, import into posttranslationally added yeast mitochondria was negligible. However, when a yeast PRS was added, significant import was observed. The import stimulating activity of the yeast PRS was shown to consist of at least two distinct factors. One of these is the recently purified 70-kD heat shock-related protein Ssalp/Ssa2p, two proteins that are 98% homologous. The other factor is an N-ethylmaleimide-sensitive protein(s). Both factors act synergistically.

Biological Transport↗

PubMed1988

Genetically engineered modification of P450 monooxygenases: functional analysis of the amino-terminal hydrophobic region and hinge region of the P450/reductase fused enzyme.

Modified constructions of a microsomal cytochrome P450, of NADPH-cytochrome P450 reductase, and of a P450/reductase fused enzyme were prepared to analyze the function of the amino-terminal hydrophobic regions of these enzymes and the hinge region of the fused enzyme. Expression plasmids for delta P450c, delta reductase, and the delta P450/reductase fused enzyme, all of which lacked their amino-terminal hydrophobic regions, were constructed by inserting each of the corresponding cDNAs between the yeast alcohol dehydrogenase I promoter and the terminator of the expression vector pAAH5. Yeast transformed with plasmids encoding delta P450 and the delta P450/reductase fused enzyme produced smaller amounts of the respective enzymes and showed lower monooxygenase activity toward 7-ethoxycoumarin than did yeast transformed with plasmids encoding the complete enzymes. Both delta P450 and delta P450/reductase were found in the microsomal fraction of the yeast cells. Yeast transformed with the expression plasmid for delta reductase produced 20 times more enzyme than did yeast transformed with the plasmid for the complete enzyme. delta Reductase was present in the soluble fraction and was 33 times more active in reducing cytochrome c than was the complete enzyme. The results suggest that the amino-terminal hydrophobic regions of P450c and the P450/reductase fused enzyme play an important role in their stability and function in the yeast microsomes. By contrast, the amino-terminal-containing P450 reductase appears to be unstable in yeast cells. Altering the size of the hinge regions does not affect the activity of the P450/reductase fused enzyme significantly, but some amino acid changes in this region increase the stability of the fused enzyme slightly.

Animals↗

PubMed1988

Primary structure of Saccharomyces cerevisiae NADPH-cytochrome P450 reductase deduced from nucleotide sequence of its cloned gene.

We isolated cDNA (pgCYR, about 2.1 kb) and genomic DNA (pgGYR, about 4 kb) clones coding for NADPH-cytochrome P450 reductase by immunoscreening of yeast Saccharomyces cerevisiae cDNA and genomic DNA libraries in phage lambda gt11. The clones were sequenced and found to encode a protein of 691 amino acid residues with a calculated molecular weight of 76,737 daltons. The amino-terminal sequence (excluding the initial methionine residue) deduced therefrom was in agreement with the protein sequence of the yeast reductase. In addition, the deduced sequence included the partial amino acid sequence determined with the papain-solubilized reductase. The total amino acid sequence of the yeast reductase showed 33-34% similarity with those of the rat, rabbit, pig, and trout reductases. In spite of low similarity in the total amino acid sequences, the possible functional domains related to binding of FAD, FMN, and NADPH were well conserved among all five species compared.

Amino Acid Sequence↗

PubMed1988

Effects of transforming growth factor-beta on deoxyribonucleic acid synthesis and iodine metabolism in porcine thyroid cells in culture.

The effect of transforming growth factor (TGF)-beta on DNA synthesis and iodine metabolism was studied in cultured porcine thyroid cells. TGF-beta dose-dependently inhibited DNA synthesis stimulated by both insulin-like growth factor I and epidermal growth factor but did not affect the number or affinity of receptors for the two growth factors, suggesting that TGF-beta inhibits postreceptor events responsible for initiation of DNA synthesis. TGF-beta was a potent inhibitor of iodine metabolism. When porcine thyroid cells were cultured with TSH for 3 days in the presence of TGF-beta, TSH-induced iodide uptake and organification were reduced at rates that were dependent on the TGF-beta concentrations. The inhibition was detectable at TGF-beta concentrations as low as 50 pg/ml, and complete suppression was seen at 1 ng/ml. Only 6 h of exposure to TGF-beta resulted in a significant inhibition of TSH-induced iodine metabolism. Treatment of thyroid cells with TGF-beta for 3 days did not reduce cAMP production stimulated by TSH. Moreover, the intracellular cAMP level of thyroid cells cultured with TSH plus TGF-beta did not differ from that of cells cultured with TSH alone. TGF-beta decreased iodide uptake stimulated by forskolin or 8-bromo-cAMP. These results strongly suggest that TGF-beta inhibits TSH-stimulated iodine metabolism, at least in part, by affecting events subsequent to cAMP production. The physiological role of TGF-beta remains to be determined, but it may be involved in the regulation of thyroid cell growth and function.

8-Bromo Cyclic Adenosine Monophosphate↗

PubMed1988

Morphological assessment of left ventricular wall and ventricular aneurysm by thallium-201 myocardial emission computed tomography.

To evaluate the influence of left ventricular (LV) aneurysm on non-infarcted ventricular wall, the shape of the left ventricular wall was assessed by thallium-201 single photon emission computed tomography (SPECT). From the morphology of the ventricular wall close to the apex, the rest images along the transaxis, horizontal long axis and vertical long axis were classified into 4 types: convergent, parallel, divergent and completely defective. LV aneurysm was detected by 2-dimensional echocardiography and/or contrast left ventriculography in 39 of 80 patients with previous myocardial infarction. Although convergence in the normal configuration of ventricular walls close to the apex, 4 of 39 patients with LV aneurysm showed this pattern. The divergent type was very specific (100%) and the most sensitive (56.4%) of the 4 for identifying LV aneurysm. Moreover, the parallel configuration indicated aneurysm in cases of inferoposterior infarction and all the completely defective cases exhibited this abnormality. Thus, thallium-201 SPECT is suitable for observing the morphology of the ventricular wall and can provide highly reliable information for detecting postinfarction ventricular aneurysm with a sensitivity of 89.7%, a specificity of 87.8% and a diagnostic accuracy of 88.8%.

Adult↗

PubMed1988

[Cardiohemodynamic and respiratory effects of eptazocine, a new analgesic agent, in anesthetized dogs].

Cardiohemodynamic and respiratory effects of eptazocine, a new analgesic agent, were studied and compared with those of pentazocine and butorphanol in anesthetized dogs. Eptazocine (1 mg/kg, i.v.) increased the heart rate (HR), left ventricular dP/dt (LVdP/dt) and cardiac output (CO), and scarcely affected the blood pressure (BP), left ventricular end-diastolic pressure (LVEDP), right atrial pressure, pulmonary arterial pressure (PAP) and pulmonary capillary wedge pressure. On the other hand, eptazocine (3 mg/kg, i.v.) decreased BP, LVdP/dt, CO and LVEDP and did not influence the pulmonary circulation. Pentazocine (1 mg/kg and 3 mg/kg, i.v.) increased BP, LVdP/dt and CO, while HR was not altered. Pentazocine also increased PAP. Butorphanol (0.1 mg/kg and 0.3 mg/kg, i.v.) decreased BP, HR and LVdP/dt, while other hemodynamic parameters were not changed. In spontaneously breathing anesthetized dogs, eptazocine (1 mg/kg and 3 mg/kg, i.v.) caused a decrease of respiratory minute volume. The fall in PO2 and pH, and a rise in PCO2 were simultaneously observed in blood gas analysis. These respiratory depressant effects of eptazocine were short-lasting, and they were less potent than those of pentazocine. Butorphanol scarcely affected the respiration. These results suggest that eptazocine has different cardiohemodynamic effects than other analgesics and produces mild respiratory depression.

Analgesics↗

PubMed1988

Inspiratory right ventricular outflow obstruction in a patient with hypertrophic cardiomyopathy.

A patient with familial hypertrophic cardiomyopathy with exertional near syncope is reported. Intra-right ventricular obstruction was demonstrated by hemodynamic studies during inspiration and the Valsalva maneuver with systemic hypotension. Improvement occurred following the administration of propranolol. It was suggested that syncope might be precipitated by hemodynamic changes such as a high output state and a depressed cardiac volume in relation to intra-right ventricular obstruction in patients with hypertrophic cardiomyopathy.

Adolescent↗

PubMed1988

The relaxation induced by indole and nonindole 5-HT agonists in the molluscan smooth muscle.

1. The abilities of two indole agonists and some nonindole agonists to induce relaxation of catch contraction and the influence of the agonists on cyclic AMP (cAMP) levels in the anterior byssus retractor muscle (ABRM) of Mytilus were investigated. 2. 5-MeOT (5-methoxytryptamine) and 5-MeODMT (5-methoxy-N,N-dimethyltryptamine) dose-dependently relaxed the contraction. 3. TFMPP (m-trifluoromethylphenyl piperazine), PAPP (p-amino-phenyl TFMPP) and mCPP (1-(3-chlorophenyl)piperazine dose-dependently relaxed the contraction, but 2MPP (1-(2-methylphenyl) piperazine and quipazine did not. 4. 5-MeOT (10(-6)M), 5-MeODMT (10(-6)M), TFMPP (10(-4)M), 2MPP (10(-4)M), quipazine (10(-4)M) and 8-OH-DPAT (3 x 10(-5) M) significantly reduced the cAMP levels, but PAPP (3 x 10(-4)M) and mCPP (10(-4)M) did not have any effect on cAMP levels. 5. These findings indicate that the pharmacological properties of 5-HT1-like receptors in the ABRM are similar to those of 5-HT1A receptors in mammalian tissues, and that the changes in cAMP levels induced by the agonists used are unlikely to be directly linked to the relaxation induced by them.

8-Hydroxy-2-(di-n-propylamino)tetralin↗