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Biomedical subjects

M Hirata

Publications and source records attributed to M Hirata.

At least 541 records · Page 30Linked to original sources
PubMed1987

Structure and expression of cDNA for an inhibitor of blood coagulation isolated from human placenta: a new lipocortin-like protein.

An inhibitor of blood coagulation, a new protein with an apparent molecular weight of 34,000 and an isoelectric point of 4.9, was purified from human placental tissue by EDTA extraction. Five cDNA clones were isolated from the human placental lambda gt11 cDNA library using the mouse monoclonal antibody raised against the coagulation inhibitor as the probe. The longest insert consists of 1,566 nucleotides, and contains 960 nucleotides entirely encoding the 320 amino acids of the inhibitor, and a poly A tail. The deduced amino acid sequence was corroborated by chemical analyses of the protein. The entire amino acid sequence shows homology to those of lipocortin I, lipocortin II, and endonexin-related proteins. The cDNA for the inhibitor was expressed in Escherichia coli under the regulation of the trc promotor of the plasmid pKK233-2. The resulting recombinant protein manifested inhibitory activities against both blood coagulation and phospholipase A2 activity, as did the coagulation inhibitor isolated from human placenta.

Amino Acid Sequence↗
PubMed1987

Interleukin-2 receptor-inducing factor(s) in adult T cell leukemia.

The expression of the interleukin-2 receptor (IL-2-R) is regulated by transcriptional and post-transcriptional mechanisms. IL-2-R gene expression is induced by pharmacological agents including calcium ions, phorbol esters such as phorbol myristate acetate (PMA) and forskolin (FK), a direct activator of adenylate cyclase. HTLV-I(+) leukemic T cells and T cell lines from patients with adult T cell leukemia (ATL) continuously expressed IL-2-R without production of IL-2. However, there was no abnormality of the structural gene for IL-2-R in these cell lines as well as in fresh leukemic cells of ATL. We have detected that many HTLV-I(+) T4(+) T cell lines constitutively produce a non-IL-2 lymphokine named ATL-derived factor (ADF), which induced the expression of the high-affinity IL-2-R on a variety of cells including HTLV-I(+) T cells, myeloid leukemia cells and YT cells. IL-2-R-inducing agents such as ADF and FK were shown to induce elevation of the mRNA levels for IL-2-R through transcriptional enhancement of the IL-2-R gene. The possible involvement of IL-2-R-inducing cytokines in the physiological lymphocyte activation and the leukemogenesis in ATL and other T cell leukemias is discussed.

Antibodies, Monoclonal↗
PubMed1987

Effects of procaine on pharmaco-mechanical coupling mechanisms activated by acetylcholine in smooth muscle cells of porcine coronary artery.

The action of procaine on pharmaco-mechanical coupling activated by application of acetylcholine (ACh) was investigated using collagenase-treated dispersed intact and skinned smooth muscle cells and intact muscle tissues of the porcine coronary artery. ACh reduced stored 45Ca2+, and this action was prevented by procaine in intact dispersed cells. The maximum reduction in the level of stored 45Ca induced by caffeine (25 mM) or inositol 1,4,5-trisphosphate (InsP3; 3 microM) was also prevented by procaine in the skinned muscle cells in the presence or absence of ATP. However, inhibitions of the latter required higher concentrations of procaine than the former. Release by 10 microM ACh of Ca2+ from its store site in the presence or absence of extracellular Ca2+ was also inhibited by procaine and was detected using the quin2 fluorescence method. In these smooth muscle tissues, ACh (above 10 nM) reduced the amount of phosphatidylinositol 4,5-bisphosphate (PI-P2) and dose dependently increased the amount of phosphatidic acid. Procaine inhibited the hydrolysis of PI-P2 activated by ACh, thus reducing the amount of InsP3 and the release of Ca2+ from the store site. It is concluded that procaine has multiple actions on the porcine coronary artery, and one of the actions related with pharmacomechanical coupling appears through inhibition of hydrolysis of PI-P2 induced by ACh.

Acetylcholine↗
PubMed1987

Effects of extracellular anions on cell growth of Chinese hamster V-79 cells.

The effects of extracellular anions (10-150 mM, added as Na salts to normal growth medium) on the growth of Chinese hamster V-79 cells were examined. Additions of NaCl and NaNO3 at concentrations greater than 60 mM reduced the growth rate dose-dependently. Several other anions also inhibited cell growth in the decreasing order of potency, SCN- greater than NO2- greater than NO3- greater than Br- greater than Cl- greater than gluconate- glutamate- greater than Mes-. When the added anions were removed, the growth rate was restored to the control rate. Cell survival was markedly reduced by the addition of SCN-, but was less affected by other anions (Cl-,NO3- and NO2-) of comparable potency. The respective syntheses of cellular DNA and protein, as estimated from the incorporation of [3H]-thymidine and [14C]leucine, also decreased with the increase in the concentration (60-120 mM) of anions added, the order of potency being SCN- greater than NO2- greater than NO3- greater than Cl-. After anion-treatment, the cellular Na+ concentration increased and the cellular Cl- concentration decreased in the order of SCN- greater than NO2- greater than NO3-, Cl-, but, the cellular K+ concentration did not change significantly. These data suggest that changes in extracellular anions affect cell growth and survival, probably through changes in the intracellular Na+ or Cl- concentration and in the rates of protein and/or DNA synthesis.

Animals↗
PubMed1987

Metabolism of phthalidyl theophylline in rat liver.

Phthalidyl theophylline (PH-TH) in rat liver was metabolized by a hydrolase to theophylline (TH) and 2-carboxybenzaldehyde, and the latter was further metabolized to 2-hydroxymethylbenzoic acid by an nicotinamide adenine dinucleotide-dependent reductase. The hydrolase could be strongly inhibited by acetazolamide, therefore, urinary excretion of PH-TH metabolites was significantly retarded when PH-TH and acetazolamide were coadministered to rats. The results from in vivo experiments suggest that PH-TH was efficiently absorbed from the gastrointestines and metabolized extensively by the liver.

Acetazolamide↗
PubMed1987

Sensitization to heat by amiloride analogues in Chinese hamster cells.

Effects of five amiloride analogues on thermal cell killing were examined using Chinese hamster V-79 cells. When cells were exposed to 42 degrees C hyperthermia in the presence of 0.2 mM amiloride or its analogue, cell survival decreased with increasing exposure time, as compared with that for exposure to 42 degrees C alone. The degree of the thermosensitizing effect varied among the test compounds, and three analogues were found to be more potent than amiloride. The results suggest that some of the amiloride analogues may be useful as hyperthermic sensitizers in the clinical treatment of cancer.

Amiloride↗
PubMed1987

Influence of collateral flow reduction on electrophysiologic properties of preexisting ischemic area and inducibility of ventricular arrhythmias in the dog.

Electrophysiologic properties of the left ventricle, vulnerability to ventricular arrhythmias and regional myocardial blood flow (RMBF) of the left ventricle were examined during superposition of acute ischemia on a healed myocardial infarction. The left circumflex coronary artery (LCX) was ligated in 13 dogs with a 28-day-old anteroapical infarction. Six (46%) of 13 dogs had reproducible ventricular tachycardia in response to programmed ventricular stimulation before LCX ligation. Ventricular fibrillation could be induced in 2 of these 6 dogs. After LCX ligation, 11 (85%) of 13 dogs had ventricular arrhythmias induced by ventricular stimulation. Nine of 13 dogs had ventricular tachycardia and 7 of 13 dogs had ventricular fibrillation. The heterogeneity of the effective refractory period (delta ERP) and the local intraventricular conduction time (LIVCT) in the border and the infarct zones of the left ventricle increased significantly after LCX ligation. RMBF in the border and the infarct zones were markedly decreased by LCX ligation. The magnitude of reduction of RMBF was correlated significantly with the prolongation of LIVCT. In conclusion, acute critical reduction of the collateral blood supply causes a more heterogeneous refractory period and conduction delay in the preexisting ischemic area of the heart, increasing the vulnerability to lethal ventricular arrhythmias.

Animals↗
PubMed1987

[Comparative studies on multiple forms of serum cholinesterase in various species].

Multiple forms of serum cholinesterase (ChE) were compared in 8 species by electrophoretic technique and the following characteristics were noted. The first moving fraction markedly hydrolyzed butyrylthiocholine and the activity was not inhibited by 10(-5)M eserine in the serum of some rabbits tested. Electrophoretic patterns of the ChE were obtained by use of two thiocholines as substrate, and the number of fractions against acetylthiocholine were more than against butyrylthiocholine in dogs, miniature pigs, rabbits, and hamsters. The activities of ChE fractions of dogs (C3), miniature pigs (C1, C2), rabbits (C1), and hamsters (C3) were inhibited by 6.1 X 10(-2)M caffein but not by 10(-4)M ethopropazine, which suggests that the fractions are all true-ChE.

Acetylthiocholine↗
PubMed1987

[A neurophysiological study on neurotoxicity of 2,5-hexanedione. Auditory brainstem responses in rats].

Conduction disturbances in the central nervous system (CNS) of rats due to 2,5-hexanedione (2,5-HD) were examined, using auditory brainstem responses (ABRs). Ten male rats (Jcl-Wistar) were given subcutaneous injection of 2,5-HD of 300 mg/kg/day five days a week for three weeks. For the control group, ten male rats (Jcl-Wistar) were employed. One week after the last administration, ABRs in rats were recorded at the scalp with subcutaneously inserted needle electrodes using the monopolar method under anesthesia. Intensity of the click sound stimulation was 25 dB and 60 dB over the threshold of human hearing level (25 dBHL and 60 dBHL). Mixed nerve conduction velocity of the caudal nerve (MNCVca) and somatosensory cortical evoked potentials by electrical stimulation at the forepaw and medulla oblongata (SEP and SEP-M) were simultaneously recorded. The significant findings observed in rats administered 2,5-HD in comparison with the control rats were as follows: 1) Delayed latencies of Ist, IInd, IIIrd, IVth and Vth components of 60 dBHL sound ABR and Ist, IIIrd, IVth and Vth components of 25 dBHL sound ABR; 2) Increased interpeak latencies (IPLs) between Ist and Vth components, IIIrd and Vth components, and IVth and Vth components of 25 dBHL sound ABR and between Ist and Vth components of 60 dBHL sound ABR; 3) Delayed latencies of P1 and N1 components of SEP; and 4) Decreased MNCVca. Prolongation of IPL between IVth and Vth components of 25 dBHL sound ABR was considered to be conduction disturbance of auditory afferent pathway in CNS.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1987

[An interview survey on health care service in small-sized manufacturers in a city of Osaka Prefecture].

An interview survey on the health care service for workers employed in small-sized enterprises was conducted in a city of Osaka Prefecture. Items surveyed were: 1) number of full-time and part-time employees by age (less than 39, 40-60, and more than 60 yr) and sex, 2) materials and production process, 3) periodic examinations for general health status and occupational diseases, and others. Of the 526 enterprises interviewed, 459 manufacturers with less than 50 employees were analyzed. The results can be summarized as follows: 1. Of the 459 manufacturers, 72.4% were those with less than 10 workers (the mean number of employees: 8.4). The major type of manufacture was electric parts processing industry. 2. The period health examination has been carried out in 372 enterprises (81.0%). The smaller the size of the company, the lower was the rate of the periodic health examination. 3. In 77.4% of the 372 enterprises, only chest X-ray was an item for the periodic health examination, which was usually carried out at the public health center of the community. 4. The number of enterprises conducting the periodic health examination designated by the Industrial Safety and Health Law (1972) was only 49 (10.7%). 5. Fourteen enterprises (3.1%) have carried out periodic examination for occupational diseases. 6. The periodic examination for degenerative diseases such as hypertension, diabetes mellitus, and other cardiovascular diseases was carried out in 57 enterprises (12.4%). The larger the size of the company, the higher was the rate in which such examination was conducted.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1987

Metabolism of 1-phthalidyl 5-fluorouracil in rat liver and enzyme induction by phenobarbital.

1. When 1-phthalidyl 5-fluorouracil (PH-FU) was incubated with isolated rat hepatocytes, 5-fluorouracil, 2-carboxybenzaldehyde (CBA) and alpha-hydroxymethylbenzoic acid (HMB) were detected as the major metabolites. 2. The enzymes involved in the metabolism of PH-FU, PH-FU hydrolase and CBA reductase are cytosolic and were induced by treating the rats with phenobarbital (PB). Treatment of rats with 3-methylcholanthrene (3-MC) did not affect either enzyme activity. 3. The PB-induced PH-FU hydrolase was inhibited by NADH and several aldehydes, while NAD stimulated the hydrolase and protected it from inactivation by SH reagents. 4. Study in vivo revealed that treatment of rats with PB accelerated the metabolism of PH-FU in the liver and markedly decreased the blood PH-FU after its oral administration to rats, which resulted in reduction of the anti-tumour activity of PH-FU. This activity was not affected by treatment of the rats with 3-MC.

Aldehyde Oxidoreductases↗
PubMed1987

[Hachimijiogan having no estrogenic activity is effective for senile colpitis].

The effects of Hachimijiogan, a Chinese medicine, were studied in patients with senile colpitis. Eighty-eight postmenopausal patients, aged 42-76 years, were treated. Hachimijiogan was effective in 65 of 66 cases with abnormal discharge, 10 of 11 with pruritus vaginae and 60 of 62 with subepithelial hemorrhage. Overall more than ninety per cent of the patients responded well. The serum FSH, E1 and E2 levels were not statistically changed in this treatment. The vaginal Pap smear showed a significant decrease in parabasal type cells and an increase in intermediate type cells (p less than 0.01). Radioimmunoassay of E1, E2, E3, testosterone, FSH, LH and prolactin in Hachimijiogan were below the levels of sensitivity. These data suggest that Hachimijiogan is effective for senile colpitis and patients with senile colpitis associated with estrogen dependent tumors could be safely treated by Hachimijiogan.

Aged↗