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Biomedical subjects

Y Moriyama

Publications and source records attributed to Y Moriyama.

At least 361 records · Page 20Linked to original sources
PubMed1988

Purification and characterization of thymidylate synthetase in the liver of the mouse bearing Ehrlich ascites tumor.

The activity of thymidylate synthetase in the liver of the ddY strain male mouse increased transitorily according to the increase in tumor cell number at maximum 7-9 days after ip transplantation of Ehrlich ascites tumor. The enzyme was able to be purified from the tumor host mouse liver or from the normal mouse liver in the same manner as from tumor cells using Affi-Gel blue and methotrexate-Sepharose 4B affinity column chromatography. The three enzyme preparations obtained were purified at 27,000-38,000-, and 8,000-fold, and yielded total activities of 11, 3, and 16% of these homogenates, respectively. These preparations were similar in molecular weight to the whole enzyme (67,000) and its subunit (34,000), optimum pH, and Km values either for deoxyuridine 5'-monophosphate or tetrahydrofolate in the presence of formaldehyde. Furthermore, the amount of 5-fluoro-2'-deoxyuridine 5'-monophosphate forming the ternary complex with the enzyme and tetrahydrofolate paralleled the enzyme activities in the cytosol fractions of the three tissues. The characteristics of the tumor host liver enzyme were similar to those of the proliferating tissues, the Ehrlich ascites tumor.

Animals↗
PubMed1988

cDNA sequence encoding the 16-kDa proteolipid of chromaffin granules implies gene duplication in the evolution of H+-ATPases.

Vacuolar H+-ATPases function in generating protonmotive force across the membranes of organelles connected with the vacuolar system of eukaryotic cells. This family of H+-ATPases is distinct from the two other families of H+-ATPases, the plasma membrane-type and the eubacterial-type. One of the subunits of the vacuolar H+-ATPase binds N,N'-dicyclohexylcarbodiimide (DCCD) and has been implicated in the proton-conducting activity of these enzymes. We have cloned and sequenced the gene encoding the DCCD-binding protein (proteolipid) of the H+-ATPase of bovine chromaffin granules. The gene encodes a highly hydrophobic protein of 15,849 Da. Hydropathy plots revealed four transmembrane segments, one of which contains a glutamic residue that is the likely candidate for the DCCD binding site. Sequence homology with the vacuolar proteolipid and with the proteolipids of eubacterial-type H+-ATPases was detected. The proteolipids from Escherichia coli, spinach chloroplasts, and yeast mitochondria matched better to the NH2-terminal part of the vacuolar protein. The proteolipids of bovine mitochondria and Neurospora mitochondria matched better to the COOH-terminal end of the vacuolar proteolipid. These findings suggest that the proteolipids of the vacuolar H+-ATPases were evolved in parallel with the eubacterial proteolipid, from a common ancestral gene that underwent gene duplication.

Amino Acid Sequence↗
PubMed1988

Effect of nifedipine, dilazep, dinitrates and propranolol on blood lactate accumulation during intensive graded exercise testing in healthy young subjects.

The aim of the present study was to elucidate the effects of 4 different cardiovascular drugs on blood lactate levels during an intensive graded exercise test in 17 healthy male subjects. In acute studies, isosorbide dinitrate and nifedipine were used. In chronic studies, propranolol dihydrochloride and dilazep dihydrochloride were used. Oxygen uptake (VO2), heart rate, blood pressure and blood lactate were measured at rest and during the final minute of each exercise session. Hemodynamic measurements during submaximum exercise were influenced by all drugs except isosorbide dinitrate. VO2 during submaximum and maximum exercises remained unchanged by all drug treatments. Blood lactate levels at rest and during submaximum and maximum exercise also did not change significantly. Work load corresponding to blood lactate concentration of 4 mM (W4 mM) and the 1st and 2nd break points of lactic acid (WBPLA1 and WBPLA2) were almost the same in all treatments. It is concluded that the 3 criteria of blood lactate obtained during the graded exercise test are not affected by these drugs in healthy males.

Adult↗
PubMed1988

Administration of human urinary colony stimulating factor after bone marrow transplantation.

A phase II study of the use of colony stimulating factor derived from human urine (CSF-HU) was performed after bone marrow transplantation (BMT). Steady and rapid recovery of leukocyte and granulocyte numbers was observed. In most patients who received CSF-HU from day 1, leukocyte numbers started to increase on day 6 and monocytes and granulocytes on day 11. Significant differences in the days to recovery of leukocytes over 1 x 10(9)/l and of granulocytes over 0.5 x 10(9)/l were observed in comparison with non-randomized control patients. In some patients in whom recovery of leukocytes was delayed, CSF also seemed to be effective in increasing leukocyte numbers from 8 days after the start of administration. There was no significant difference in the rate of relapse of leukemia between the two groups. CSF-HU seems very promising as a treatment of patients after BMT by shortening the period of leukopenia or granulocytopenia.

Adolescent↗
PubMed1988

[Clinical studies of natural interferon alpha (HLBI) in chronic myelogenous leukemia--a multi-institutional cooperative study in Japan].

Clinical trials of natural interferon-alpha (HLBI) in the treatment of Philadelphia chromosome (Ph1) positive chronic myelogenous leukemia (CML) were carried out in a cooperative study of 22 institutions in Japan. Patients with CML in chronic and accelerated phase were given intramuscular or subcutaneous injections of HLBI at the dose of 6 X 10(6) U/body on consecutive days. Of the 47 patients in this study, forty-one were evaluable for clinical effects, and 42 could be assessed for adverse effects. Among 30 evaluable patients in the chronic phase, 9 (30.0%) achieved complete remission (CR) and 20 (66.7%) partial remission (PR). Only one patient had no response (NR), and the response rate (CR + PR) in chronic phase was 96.7% (29/30). Among 11 patients in the accelerated phase, 3 (27.3%) achieved CR and 4 (36.4%) PR. The response rate in the accelerated phase was 63.6% (7/11). In all 41 evaluable patients, the response rate was 87.8% (36/41). In 5 of 13 responding patients treated for more than 6 months, cytogenetic investigation showed the decline of Ph1 positive bone marrow cells from 100% to 92-0% (mean 46%). Adverse effects such as fever (52.4%), general fatigue (35.7%), and liver dysfunction (21.4%), were observed, but they were usually mild and reversible. No patient was taken off this study because of these toxicities. The results confirm the clinical efficacy of HLBI in patients with CML in the chronic and accelerated phase.

Adolescent↗
PubMed1987

Internal anion binding site and membrane potential dominate the regulation of proton pumping by the chromaffin granule ATPase.

Effects of anions and membrane potential on the reconstituted proton pump from chromaffin granules were investigated. When acetate was present inside of the vesicles, ATP-dependent proton uptake was absolutely dependent on external chloride. Without external chloride, however, substantial proton uptake was observed when chloride or sulfate was present inside of the vesicles. Inside negative membrane potential drove ATP-dependent proton uptake regardless of the anion species present inside or outside of the vesicles. It is concluded that the internal anion binding site and membrane potential regulate the proton pumping activity of the ATPase.

Acetates↗
PubMed1987

Nucleotide binding sites and chemical modification of the chromaffin granule proton ATPase.

The purified proton ATPase of chromaffin granules contains five different polypeptides denoted as subunits I to V in the order of decreasing molecular weights of 115,000, 72,000, 57,000, 39,000, and 17,000, respectively. The purified enzyme was reconstituted as a highly active proton pump, and the binding of N-ethylmaleimide and nucleotides to individual subunits was studied. N-Ethylmaleimide binds to subunits I, II, and IV, but inhibition of both ATPase and proton pumping activity correlated with binding to subunit II. In the presence of ADP, the saturation curve of ATP changed from hyperbolic to a sigmoid shape, suggesting that the proton ATPase is an allosteric enzyme. Upon illumination of the purified enzyme in the presence of micromolar concentrations of 8-azido-ATP, alpha-[35S]ATP, or alpha-[32P]ATP subunits I, II, and IV were labeled. However, at concentrations of alpha-[32P]ATP below 0.1 microM, subunit II was exclusively labeled in both the purified and reconstituted enzyme. This labeling was absolutely dependent on the presence of divalent cations, like Mg2+ and Mn2+, while Ca2+, Co2+, and Zn2+ had little or no effect. About 0.2 mM Mg2+ was required to saturate the reaction even in the presence of 50 nM alpha-[32P]ATP, suggesting a specific and separate Mg2+ binding site on the enzyme. Nitrate, sulfate, and thiocyanate at 100 mM or N-ethylmaleimide and 7-chloro-4-nitrobenzo-2-oxa-1,3-diazole at 100 microM prevented the binding of the nucleotide to subunit II. The labeling of this subunit was effectively prevented by micromolar concentrations of three phosphonucleotides including those that cannot serve as substrate for the enzyme. It is concluded that a tightly bound ADP on subunit II is necessary for the activity of the enzyme.

Adenosine Diphosphate↗
PubMed1987

The purified ATPase from chromaffin granule membranes is an anion-dependent proton pump.

The proton-ATPase of chromaffin granules was purified so as to maintain its proton-pumping activity when reconstituted into phospholipid vesicles. The purification procedure involved solubilization with polyoxyethylene 9 lauryl ether, hydroxylapatite column, precipitation by ammonium sulfate, and glycerol gradient centrifugation. The protease inhibitor mixture used in previous studies inhibited the proton-pumping activity of the enzyme; therefore, the protein was stabilized by pepstatin A and leupeptin. The enzyme was purified at least 50-fold with respect to both ATPase and proton-pumping activity. The ATP-dependent proton uptake activity of the reconstituted enzyme was absolutely dependent on the presence of Cl- or Br- outside the vesicles, whereas sulfate, acetate, formate, nitrate, and thiocyanate were inhibitory. Sulfate inhibition seems to be due to competition with Cl- on the anion-binding site outside the vesicles, whereas nitrate and thiocyanate inhibited only from the internal side. As with the inhibition by N-ethylmaleimide, the proton-pumping activity was much more sensitive to nitrate than the ATPase activity. About 20 mM nitrate were sufficient for 90% inhibition of the proton-pumping activity while 100 mM inhibited only 50% of the ATPase activity both in situ and in the reconstituted enzyme. The possible regulatory effect of anions on the ATP-dependent proton uptake in secretory granules is discussed.

4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid↗
PubMed1987

Rhythmical jaw movements and lateral ponto-medullary reticular neurons in rats.

Neuronal activity in the lateral reticular formation was investigated in urethane-anesthetized rats. Stimulation of anterior and posterior cortical areas induced two types of rhythmical jaw movements (RJM). The effects of stimulation of these cortical areas, the peripheral nerves, and the trigeminal motor nucleus on these neurons and their activity during the RJM were analyzed. The smallest percentage of neurons receiving anterior cortical input received peripheral input, and most neurons with posterior cortical input received peripheral input. Sixty per cent of reticular neurons showed the rhythmical firing closely related to the RJM. Therefore, these neurons may participate in masticatory pattern formation.

Animals↗
PubMed1987

Non-simultaneous primary cancers in five different organs in a case of cancer family syndrome.

Non-simultaneous primary malignant tumors in five different organs were detected in a case of cancer family syndrome, and the patient's offspring were found to have colorectal cancers during follow-up. The first cancer in the patient was found in the transverse colon at the age of 47, and partial colectomy was carried out. The second and third were cancers of the cecum and gallbladder which were found concurrently at the age of 61, and ileocecal resection and cholecystectomy were carried out simultaneously. The fourth was cancer of the urinary bladder which was found at the age of 66, and partial cystectomy with interstitial irradiation using a radon seed in the residual urinary bladder was carried out. The fifth was cancer of the stomach at the age of 72, and subtotal gastrectomy was carried out. All of the resected specimens were demonstrated to be different carcinomas histologically. The father and 5 of the 7 siblings of this patient suffered from gastrointestinal or uterine cancers. Furthermore, two daughters of this patient were affected with cancer; the younger with cancer of the descending colon at the age of 47, and the elder with cancers of the transverse colon and rectum at the age of 54. Thus, familial clustering of cancer was shown. Genetic characteristics may have contributed to the development of multiple primary cancers in this family.

Aged↗