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Biomedical subjects

N Murata

Publications and source records attributed to N Murata.

At least 91 records · Page 5Linked to original sources
PubMed1999

The effect of nipradilol on the isoproterenol-induced depression of contractions in the cat soleus muscle.

The effect of nipradilol on the isoproterelol-induced depression of contractions of the soleus muscle of the anesthetized cats was studied. Isoproterenol (0.3 microg/kg) injected intravenously decreased the tension and degree of fusion of incomplete tetanic contractions of the soleus muscle of the anesthetized cats. The effect of isoproterenol was blocked by nipradilol (> or = 3 microg/kg), desnitro-nipradilol (> or = 10 microg/kg) and propranolol (> or = 10 microg/kg), but not by nitroglycerin (10-100 microg/kg). Nipradilol (30 microg/kg) and desnitronipradilol (300 microg/kg) almost completely antagonized the depressor effects of isoproterenol. These results coupled with evidence that nipradilol does not penetrate the blood-brain barrier indicate that nipradilol exerts an anti-tremor action by blocking peripheral beta2-adrenoceptors.

Adrenergic beta-Agonists↗
PubMed1999

[Myelodysplastic syndrome accompanied by i(17) (q10) anomaly following pure red cell aplasia and transient myeloproliferative stage].

A 71-year-old man was given a diagnosis of pure red cell aplasia (PRCA) in May 1995. However, immunosuppressive agents, including prednisolone, azathioprine, and cyclosporin A, were not effective, and he required frequent red cell transfusions. In September 1995, leukocytosis and thrombocytosis developed (peaking at 10,100/microliter white cells and 98.1 x 10(4)/microliter platelets, respectively, in November 1996). Conversely, the patient's peripheral blood count began to decrease in July 1996, and pancytopenia progressed thereafter i(17) (q10) chromosomal abnormality of bone marrow cells was detected in November 1996. The patient was readmitted due to the progression of thrombocytopenia (1.2 x 10(4)/microliter). His bone marrow has 16.6% blasts, and a diagnosis of myelodysplastic syndrome (MDS) was made. The patient died in November 1997. His hematological state demonstrated significant changes in a relatively short period and severe hypoerythropoiesis and eosinophilia of the bone marrow persisted throughout the clinical course. These findings suggested that a common deranged stem cell was the origin of 3 different states; PRCA, chromic myeloproliferative disorder, and MDS. The i(17) (q10) anomaly may have caused the acute proliferation of blasts and pancytopenia.

Aged↗
PubMed1999

[Marked thrombocytopenia after high-dose intravenous gamma globulin in a pregnant woman with idiopathic thrombocytopenic purpura].

A 35-year-old pregnant woman had thrombocytopenia with a platelet count of 6.3 x 10(4)/microliter. After her third normal delivery, peripheral blood studies revealed that the patient had a normal Hb concentration and leukocyte count, with mild thrombocytopenia. A diagnosis of idiopathic thrombocytopenic purpura (ITP) was made based on the high megakaryocyte count of 338/microliter and PAIgG of 40.8 ng/10(7) cells in January 1995. The patient was followed without treatment. She was 9 weeks pregnant on June 7, 1996, and desired an abortion. Her platelet count was 6.3 x 10(4)/microliter, leukocyte count 8,600/microliter, and Hb 13.7 g/dl at the time. She was given high-dose intravenous gammaglobulin (Globenin-I) at 400 mg/kg/day for 5 consecutive days. The platelet count was found to have decreased markedly, to 0.9 x 10(4)/microliter on June 11. The percentage reduction in the Hb concentration, leukocyte count, and platelet count after gammaglobulin treatment was 11.7%, 46.6%, and 85.8%, respectively. The PAIgG titer had increased to 181.2 ng/10(7) cells on June 17, but hypergammaglobulinemia was suspected. The patient was started on prednisolone on June 24, and an abortion was performed on July 29. The mechanism of thrombocytopenia after infusion of Globenin-I was unknown. We suspect that Globenin-I treated with polyethylene glycol was one of the possible causes of myelosuppression in this case.

Adult↗
PubMed1999

[Risk assessment in urgent or emergent coronary artery bypass grafting for acute coronary syndrome].

Emergent coronary artery bypass grafting (CABG) for the treatment of acute coronary syndrome has increased the operative mortality. Forty-nine patients underwent urgent or emergent CABG for the treatment of medically refractory unstable angina in 10 patients, and for acute myocardial infarction (AMI) in 39 patients. Ten operative deaths were occurred in the AMI patients, and the mortality was 20 percent. The preoperative risk factors were evaluated in 10 patients who died in the operative period. Cardiopulmonary resuscitation before operation, intra aortic balloon pumping, the use of catecholamine, and intubation with or without percutaneous cardiopulmonary support revealed operative risk factor. Because the patients who have preoperatively shock, it seemed to be needed that the rescue of the patients should improve the clinical results for urgent or emergent CABG.

Adult↗
PubMed1999

Pharmacokinetic interaction between warfarin and a uricosuric agent, bucolome: application of In vitro approaches to predicting In vivo reduction of (S)-warfarin clearance.

A uricosuric agent, bucolome, has been shown to intensify the anticoagulant effect of warfarin. The aims of the present study were to clarify its mechanism(s) and to apply in vitro approaches for predicting this potentially life-threatening in vivo interaction. An in vivo study revealed that Japanese patients given warfarin with bucolome (300 mg/day, n = 21) showed a 1.5-fold greater international normalized ratio than those given warfarin alone (n = 34) despite that the former received a 58% smaller warfarin dose than the latter. Enantioselective assays revealed that bucolome increased plasma unbound fractions of (S)- and (R)-warfarin by 2-fold (p <.01), reduced unbound oral clearances of (S)- and (R)-warfarin by 84 (p <.01) and 26% (p <.05), respectively, and inhibited the unbound formation clearance for (S)-warfarin 7-hydroxylation by 89% (p <.01). In contrast, bucolome elicited no appreciable changes in the plasma unbound (S)-warfarin concentration versus the international normalized ratio relationship. In vitro studies with recombinant human cytochrome P-450 2C9 and liver microsomes showed that bucolome was a potent mixed-type inhibitor for (S)-warfarin 7-hydroxylation, with K(i) of 8.2 and 20.2 microM, respectively. An in vitro model incorporating maximum unbound bucolome concentration in the liver estimated as a sum of hepatic artery and portal vein concentrations and in vitro K(i) made an acceptable prediction for bucolome-induced reductions in in vivo total (bound + unbound) oral clearance, unbound oral clearance, and unbound formation clearance for (S)-warfarin. In conclusion, the augmented anticoagulant effect of warfarin by bucolome due to the metabolic inhibition for pharmacologically more potent (S)-warfarin may be predictable from in vitro data.

Adult↗
PubMed1999

[Clinical trial of prophylactic hepatic arterial chemotherapy for liver metastases in patients with Dukes' C colorectal cancer].

Preliminary results of a prospective non-randomized trial of prophylactic hepatic arterial chemotherapy for liver metastases from colorectal cancer are presented. Twenty-two colorectal cancer patients (infusion group) in Dukes' C stage were given hepatic arterial infusion of 5-FU (500 mg/body for 1 hr per week, repeated 50 times) and peroral UFT-E (2.0 g/body, daily). Informed consent was obtained from all patients. Adverse effects and postoperative recurrence in the infusion group were compared with those of patients with UFT-E alone (control group). Complications related to hepatic arterial infusion in the infusion group were also demonstrated. There was no adverse effect in the control group, while diarrhea (grade 1) developed in one patient (5%) and pigmentation in five (24%) in the infusion group. Complications related to infusion were found in five patients (5%). Three patients in the infusion group presented with metachronous hepatic lesions, two of which were resected successfully. In the control group, one patient died of marked hepatic metastases, and one developed ovarian metastasis with lymph node involvement. Our regimen appears hematologically safe, however, the high frequency of pigmentation should be kept in mind. The oncological benefit of this chemotherapy would be clarified by a larger series of cases and longer follow-up.

Administration, Oral↗
PubMed1999

Responses to cold shock in cyanobacteria.

Acclimation of cyanobacteria to low temperatures involves induction of the expression of several families of genes. Fatty acid desaturases are responsible for maintaining the appropriate fluidity of membranes under stress conditions. RNA-binding proteins, which presumably act analogously to members of the bacterial Csp family of RNA chaperones, are involved in the maintenance of the translation under cold stress. The RNA helicase, whose expression is induced specifically by cold, might be responsible for modifying inappropriate secondary structures of RNAs induced by cold. The cold-inducible family of CIp proteins appears to be involved in the proper folding and processing of proteins. Although genes for cold-inducible proteins in cyanobacteria are heterogeneous, some common features of their untranslated regulatory regions suggest the existence of a common factor(s) that might participate in regulation of the expression of these genes under cold-stress conditions. Studies of the patterns of expression of cold-inducible genes in cyanobacteria have revealed the presence of a cold-sensing mechanism that is associated with their membrane lipids. Available information about cold-shock responses in cyanobacteria and molecular mechanisms of cold acclimation are reviewed in this article.

Adaptation, Physiological↗
PubMed1999

Evaluation of surgeries for rheumatoid shoulder based on the destruction pattern.

OBJECTIVE: To identify the optimal treatment of rheumatoid shoulder, we analyzed the clinical results of shoulder surgeries according to each type of shoulder destruction pattern. METHODS: Forty-seven shoulder surgeries for rheumatoid arthritis (18 arthroscopic synovectomies, 10 total shoulder replacements, 19 humeral head replacements) were assessed clinically and compared in regard to 5 different destruction patterns of rheumatoid shoulder (nonprogressive, arthrosis-like, erosive, collapse, and mutilating patterns). RESULTS: For nonprogressive-type shoulders, we were able to obtain both pain relief and range of motion (ROM) improvement with arthroscopic synovectomy. For erosive-type shoulders, we could obtain pain relief but no ROM improvement with synovectomy; and we obtained both pain relief and ROM improvement with prosthetic replacement. For the collapse-type shoulders, we could not obtain pain relief or ROM improvement with arthroscopic synovectomy, but did obtain pain relief with prosthetic replacement. For mutilating-type shoulders, we could obtain only pain relief with prosthetic replacement. The results of the various surgeries for rheumatoid shoulder were distinctly different depending on the shoulder destruction patterns. CONCLUSION: These findings could be of value for the selection of treatment, including a surgical procedure, for rheumatoid shoulders. For the nonprogressive-type and for erosive-type shoulders before bone destruction progresses, arthroscopic synovectomy should be selected. For erosive-type shoulders after bone destruction, for the collapse-type, and for mutilating-type shoulders, prosthetic replacement should be selected. In regard to the prosthetic replacement, the humeral component should be cemented because the incidence of migration in noncemented humeral component procedures was high.

Adult↗
PubMed1999

[CBDCA, etoposide and epirubicin high-dose combination chemotherapy supported by peripheral blood stem cell transplantation (PBSCT) in metastatic breast cancer].

Six metastatic breast cancer patients, including one brain metastasis, one lung metastasis, three local recurrences and one bone metastasis, underwent multidrug chemotherapy with CBDCA, Etoposide (ETP) and Epirubicin (EPI). Each patient received two courses of PBSC mobilization chemotherapies and subsequently received high-dose chemotherapies for at least two courses. CBDCA AUC 4, ETP 300 mg/m2 and EPI 40 mg/m2 were administered intravenously as a PBSC mobilization chemotherapy, and high-dose chemotherapies were performed under the regimen of CBDCA AUC 8, ETP 900 mg/m2 and EPI 60 mg/m2. Severe bone marrow suppression due to high-dose chemotherapies was off sct by autologous peripheral blood stem cell transplantation (PBSCT). The PBSC mobilization chemotherapies resulted in one CR, three PR, one NC and one PD in the six patients. The PD patient died before high-dose chemotherapy. Consequently, the remaining five patients received the high-dose chemotherapies, which achieved three CR, one PR and one PD in the five patients. The response rate of high-dose chemotherapy was 80% (4/5 cases). In overall outcome, three patients have continued 16, 12 and 10 months tumor-free survival, and three patients died of cancer progression. High-dose chemotherapy with CBDCA, ETP and EPI has led to increased CR rates in metastatic breast cancer, and such therapy has desirable effect on the patient's prognosis.

Adult↗
PubMed1998

Downregulation of mRNA expression of Edg-3, a putative sphingosine 1-phosphate receptor coupled to Ca2+ signaling, during differentiation of HL-60 leukemia cells.

We measured the mRNA expression of the recently identified putative sphingosine 1-phosphate (S1P) receptors, i.e., Edg-1, AGR16/H218, and Edg-3, in HL-60 leukemia cells. Of these putative receptors, Edg-3 mRNA was abundantly expressed in undifferentiated HL-60 cells. Further, its mRNA expression was markedly downregulated by inducers of cell differentiation such as dibutyryl cAMP, retinoic acid, and 1alpha, 25-dihydroxyvitamin D3. The reduction of mRNA expression was associated with the attenuation of an S1P-induced increase in cytoplasmic free Ca2+ concentration. Thus, Edg-3, whose mRNA expression is downregulated during cell differentiation, may be responsible for the S1P-induced Ca2+ response in HL-60 leukemia cells.

3T3 Cells↗
PubMed1998

Structure and expression of fatty acid desaturases.

Fatty acid desaturases are enzymes that introduce double bonds into fatty acyl chains. They are present in all groups of organisms, i.e., bacteria, fungi, plants and animals, and play a key role in the maintenance of the proper structure and functioning of biological membranes. The desaturases are characterized by the presence of three conserved histidine tracks which are presumed to compose the Fe-binding active centers of the enzymes. Recent findings on the structure and expression of different types of fatty acid desaturase in cyanobacteria, plants and animals are reviewed in this article. Roles of individual desaturases in temperature acclimation and principles of regulation of the desaturase genes are discussed.

Acclimatization↗
PubMed1998

Translocation (10;11)(p13;q13) and MLL gene rearrangement in a case of AML (M5a) with aggressive leukemia cutis.

A male patient with a secondary acute monocytic leukemia whose leukemia cells had a t(10;11)(p13;q13) chromosomal abnormality is described. Gene analysis disclosed that the patient's leukemia cells had MLL gene rearrangement. His leukemia cells responded poorly to chemotherapy, and the patient developed an unusual aggressive leukemia cutis. A t(10;11)(p13;q13) chromosomal abnormality that expresses MLL gene rearrangement has not been reported previously in secondary leukemia.

Aged↗
PubMed1998

Biochemical characterization of a delta12 acyl-lipid desaturase after overexpression of the enzyme in Escherichia coli.

The Delta12 acyl-lipid desaturase of Synechocystis sp. PCC 6803 was overexpressed in Escherichia coli as an active enzyme. The overexpressed protein was associated with cell membranes; it represented about 10% of the total cellular protein and 25% of the total membrane protein. The enzyme in the membrane fraction exhibited strong fatty-acid desaturase activity. The desaturase in salt-washed membranes was stabilized by the presence of sorbitol. Storage of salt-washed membranes in 2 M sorbitol at 4 degrees C and at pH 7-8 for six days resulted in the loss of less than 10% of the desaturase activity. The desaturase activity had a positive temperature coefficient, a result that suggests that the increase in the desaturation of fatty acids at low temperature might not be caused by the activation of desaturases at low temperature but, rather, by the increased synthesis of desaturases de novo.

Cyanobacteria↗
PubMed1998

A genetically engineered increase in fatty acid unsaturation in Synechococcus sp. PCC 7942 allows exchange of D1 protein forms and sustenance of photosystem II activity at low temperature.

Photosystem II (PSII)-reaction-center protein D1 is encoded by three psbA genes in Synechococcus sp. PCC 7942. The psbAI gene encodes D1 form I (D1:1) and the psbAII and psbAIII genes encode the transiently expressed D1 form II (D1:2). We have studied the role of membrane-lipid unsaturation in the expression of psbA genes at low temperature, using a Synechococcus transformant with an increased unsaturation level of membrane lipids. Transfer of the cells from 32 degrees C to 25 degrees C under growth light resulted in the exchange of D1:1, the prevailing form, for D1:2 in the wild-type bacterium and the transformant, with no loss of PSII activity. Lowering the temperature further to 18 degrees C caused a drastic decrease in PSII activity in the wild-type bacterium, whereas the transformant was much less affected. Similar decreases in psbAI transcripts and loss of D1:1 occurred in both strains at 18 degrees C, with concomitant accumulation of psbAII/III transcripts, the latter event being especially prominent in the wild-type bacterium. However, the wild-type bacterium was incapable of accumulating D1:2 to compensate for the loss of D1:1, which resulted in disassembly of PSII at low temperature. These results imply translational rather than transcriptional regulation of psbA gene expression in Synechococcus 7942 at low temperature, and demonstrate the crucial role of the degree of membrane-lipid unsaturation in promotion of exchange of the D1 protein forms and thus the sustenance of PSII function at low temperature.

Chlorophyll↗
PubMed1998

Knee and/or hip joint destruction in rheumatoid arthritis is associated with HLA-DRB1*0405 in Japanese patients.

To determine the prognostic factors for knee and/or hip joint destruction in rheumatoid arthritis (RA) patients, we typed 379 RA patients for HLA-DRB alleles and analysed the antigen frequencies. The DRB1*0405 antigen frequency in RA patients who underwent total knee replacement and/or total hip replacement was significantly higher than in those who did not have replacements, which meant that DRB1*0405 was associated with knee and/or hip joint destruction. This finding may be of value for predicting knee and/or hip joint destruction in RA.

Adolescent↗