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Biomedical subjects

H Oh

Publications and source records attributed to H Oh.

At least 91 records · Page 5Linked to original sources
PubMed1996

Signalling defect in FMLP-induced neutrophil respiratory burst in myelodysplastic syndromes.

Myelodysplastic syndromes (MDS) are clonal haematological disorders and MDS neutrophils have various abnormal functions which cause an increased risk of infective mortality. We examined luminol-dependent chemiluminescence and cytoplasmic Ca2+ increase in order to characterize the mechanisms of a signalling defect in MDS neutrophil respiratory burst. In MDS patients, chemiluminescence stimulated with N-formyl-L-methionyl-L-leucil-L-phenylalanine (FMLP) and calcium ionophore A23187 was defective (17.2 +/- 13.7 v 44.3 +/- 16.6, P = 0.001; 42.2 +/- 21.3 v 82.0 +/- 23.6, P < 0.05, respectively), but phorbol 12-myristate 13-acetate (PMA) chemiluminescence was normal (73.4 +/- 26.9 v 79.5 +/- 23.8, P = 0.52). There were no statistical significances in cytoplasmic Ca2+ increase stimulated with FMLP and recombinant human interleukin-8 (rhIL-8) compared with controls (251.1 +/- 104.3 v 272.7 +/- 41.2, P = 0.295; 238.6 +/- 65.0 v 253.9 +/- 38.3, P = 0.567, respectively). Flow cytometric analysis of MDS neutrophils disclosed that most MDS patients showed normal neutrophil cytoplasmic Ca2+ response to FMLP and rhIL-8. However, two patients with refractory anaemia with excess of blasts displayed a significant decrease of both chemiluminescence and cytoplasmic Ca2+ response to FMLP, and they also displayed low expression of FMLP receptor. These data suggest that most MDS patients have low FMLP chemiluminescence which is not due to a defect in the FMLP receptor. It is proposed that defective FMLP chemiluminescence in MDS results from a putative defect in protein kinase C- and Ca(2+)-independent cell-signalling mechanisms. Only a small group of patients have numerical or structural defects in the FMLP receptor, causing significant decrease of neutrophil respiratory burst.

Calcium↗
PubMed1996

Purification and characterization of a fibrinolytic enzyme produced from Bacillus sp. strain CK 11-4 screened from Chungkook-Jang.

Bacillus sp. strain CK 11-4, which produces a strongly fibrinolytic enzyme, was screened from Chungkook-Jang, a traditional Korean fermented-soybean sauce. The fibrinolytic enzyme (CK) was purified from supernatant of Bacillus sp. strain CK 11-4 culture broth and showed thermophilic, hydrophilic, and strong fibrinolytic activity. The optimum temperature and pH were 70 degrees C and 10.5, respectively, and the molecular weight was 28,200 as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The first 14 amino acids of the N-terminal sequence of CK are Ala-Gin-Thr-Val-Pro-Tyr-Gly-Ile-Pro-Leu-Ile-Lys-Ala-Asp. This sequence is identical to that of subtilisin Carlsberg and different from that of nattokinase, but CK showed a level of fibrinolytic activity that was about eight times higher than that of subtilisin Carlsberg. The amidolytic activity of CK increased about twofold at the initial state of the reaction when CK enzyme was added to a mixture of plasminogen and substrate (H-D-Val-Leu-Lys-pNA). A similar result was also obtained from fibrin plate analysis.

Amino Acid Sequence↗
PubMed1996

Randomized trials between behenoyl cytarabine and cytarabine in combination induction and consolidation therapy, and with or without ubenimex after maintenance/intensification therapy in adult acute myeloid leukemia. The Japan Leukemia Study Group.

PURPOSE: We analyzed complete remission (CR), disease-free survival (DFS), and event-free survival (EFS) rates in two groups of patients treated with either N4-behenoyl-1-beta-D-arabinosylcytosine (BHAC) or cytarabine, and analyzed DFS with or without ubenimex, a biologic response modifier. PATIENTS AND METHODS: Newly diagnosed patients with acute myeloid leukemia (AML) were randomized to receive either BHAC or cytarabine as remission-induction combination chemotherapy and two courses of consolidation therapy. After maintenance/intensification therapy, patients in CR were randomized to receive either ubenimex and no drug. RESULTS: Of 341 patients registered, 326 were assessable. The age of assessable patients ranged from 15 to 82 years (median, 48). The overall CR rate was 77%: 72% in the BHAC group and 81% in the cytarabine group, and there was a significant difference between the two groups (P = .035, chi 2 test). The predicted 55-month EFS rate of all patients was 30%: 23% in the BHAC group and 35% in the cytarabine group, with a significant difference between groups (P = .0253). The predicted 55-month DFS rate of all CR patients was 38% and that of CR patients less than 50 years of age was 47%. There was no significant difference in DFS between the ubenimex group and the group that did not receive ubenimex. CONCLUSION: Analyses of our clinical trial showed that the use of BHAC in remission-induction therapy and in consolidation therapy resulted in poorer CR and EFS rates in adult AML patients compared with the use of cytarabine at the doses and schedules tested. Immunotherapy with ubenimex after the end of all chemotherapy did not improve DFS.

Acute Disease↗
PubMed1996

[Resolution of psoriasis vulgaris following allogeneic bone marrow transplantation for aplastic anemia].

A 36 year-old man had suffered from psoriasis vulgaris for about 25 years. He had received corticosteroids ointment and PUVA therapy with partial response. In 1987, he was diagnosed as having aplastic anemia (AA) and treated with various medications, but failed to respond. He received an allogeneic bone marrow transplantation (BMT) from his histocompatible sister in 1993. Conditioning regimen of BMT consisted of total lymphoid irradiation (7.5 Gy) and cyclophosphamide (200 mg/kg). Cyclosporin A and methotrexate were given for prophylaxis of graft-versus-host disease. On day 24, bone marrow examination disclosed normocellular marrow and karyotypic analysis completely confirmed the donor's origin. Before BMT, he had systemic psoriatic plaques with scales, together with nail involvement. After BMT, psoriatic plaques disappeared and nail deformity improved. He has remained in remission of his AA and completely free of psoriasis in the absence of immunosuppressive or other treatments. The cause of psoriasis is thought to be an immune-mediated disorder. Our case supports the observation that changing the host's immune system through allogeneic BMT can achieve remission of psoriasis. It is suggested that allogeneic BMT may be one strategy for the treatment of intractable immune-mediated disorders.

Adult↗
PubMed1996

[Lupus anticoagulants in patients with systemic lupus erythematosus].

Lupus anticoagulants (LA) and anticardiolipin antibodies (aCL) are known as thrombosis-related antiphospholipid antibodies. LA is not as well characterized as aCL, and the relation between LA and aCL is not clarified. Since standardized method for the detection of LA has not been established, we measured LA activities in outpatients with SLE by using two different methods (KCT and dRVVT), and analyzed the characteristics of LA in SLE. LA was detected in 29.8% of all samples (14.3% in both methods, 15.5% in one method). IgG-aCL and IgM-aCL was detected in 38% and 20%, respectively, of all LA positive samples. Though a good correlation was observed between LA activities and IgG-aCL levels, a considerable number of LA positive samples were negative for aCL. This indicated the presence of factors with LA activity other than aCL. On the contrary there was also a high percentage of LA negative samples with positive aCL (42.4% in IgG-aCL, 47.4% in IgM-aCL), suggesting the presence of aCL with poor or low LA activity. These findings showed the heterogeneity of antiphospholipid antibodies both in LA and in aCL. The platelet function tests showed increased platelet adhesiveness and normal platelet aggregation in LA positive patients with SLE even in the inactive phase. The serum levels of factors such as protein C, protein S, antithrombin III and thrombomodulin were within normal range. Clinical features such as hemolytic anemia, thrombosis and abortion were more frequently observed in LA positive population than in LA negative population. The clinical features tend to be different between patients with dRVVT-LA and those with KCT-LA, though not significant. Because of the heterogeneity in LA, a combination of more than two different methods including dRVVT was recommended for the detection and the evaluation of LA.

Adult↗
PubMed1996

Granisetron in the prevention of vomiting induced by conditioning for stem cell transplantation: a prospective randomized study.

We conducted a prospective randomized study to compare granisetron, a 5-hydroxytryptamine-3 receptor antagonist with standard anti-emetics (control group) consisting mainly of metoclopramide, in the prophylaxis of emesis induced by conditioning prior to stem cell transplantation. Fifty-eight patients were evaluable for analysis. The number of emetic episodes expressed in terms of patient-days was significantly lower in the granisetron group than in the control group (P < 0.001). During the first 24 h of conditioning, 27 of the 31 patients (87.1%) in the granisetron group achieved control of emesis with less than three emetic episodes (major < or = ) a day compared with 37.0% in the control group (P < 0.001). The same degree of emesis control was maintained throughout the conditioning period in 51.% of patients in the granisetron group compared with 0% in the control group (P < 0.001). Adverse reactions were observed in 11.4% of patients in the granisetron group and in 25.9% in the control group. None of the events were serious. Based on these data, we conclude that granisetron is superior to standard antiemetics in protecting against the vomiting induced by conditioning for stem cell transplantation.

Adolescent↗
PubMed1996

[The combination therapy with vinca-alkaloid slow infusion and cholchicine was effective to refractory idiopathic thrombocytopenic purpura. The patient could receive femoral head replacement in safety].

A 46-year-old man with idiopathic thrombocytopenic purpura (ITP) refractory to corticosteroid, splenectomy and other drugs was admitted to our hospital in August, 1994, because of aseptic necrosis of the right femoral head. Although high-dose intravenous gamma-globulin was ineffective, the platelet count was increased within two weeks by the combination therapy that consisted of 0.02 mg/kg vincristine alternating with 0.1 mg/kg vinblastine by slow infusion at a 1-week interval, and oral 1.5 mg/day colchicine. He subsequently underwent the femoral head replacement. This combination therapy seems to be useful for refractory ITP in preparation for surgery.

Colchicine↗
PubMed1995

Significant reduction of medical costs by differentiation therapy with all-trans retinoic acid during remission induction of newly diagnosed patients with acute promyelocytic leukemia. The Japan Adult Leukemia Study Group.

BACKGROUND: Differentiation therapy with all-trans retinoic acid (RA) induces more than 80% complete remission with the least complications in patients with acute promyelocytic leukemia (APL). The authors studied the cost-benefit of this new treatment modality compared with conventional chemotherapy in newly diagnosed patients with APL. METHODS: Costs were calculated retrospectively through the monthly bills of each patient to national health insurance and were compared between 36 patients treated with conventional chemotherapy in the AML-87 or AML-89 studies and 40 patients treated with all-trans RA alone or with all-trans RA plus low dose chemotherapy in the AML-92 study of the Japan Adult Leukemia Study Group who were treated at 22 university and cancer hospitals in Japan. RESULTS: Average medical costs except for antileukemic drugs during 2 months after admission were 4,164,026 yen (approximately US$46,300) in the chemotherapy group and 2,906,825 yen (approximately US$32,300) in the all-trans RA group (P < 0.0001). The difference resulted mainly from the costs of antibiotics and of platelet and erythrocyte transfusions. Average costs of antibiotics were 650,494 yen (approximately US$7,200) and 349,138 yen (approximately US$3,900), respectively (P < 0.0002), and those of platelet and erythrocyte transfusions were 1,016,190 yen (approximately US$11,300) and 633,444 yen (approximately US$7,000), respectively (P < 0.0020). CONCLUSION: During the remission induction therapy of newly diagnosed APL, all-trans RA significantly reduced medical costs. all-trans RA should be incorporated into the front-line therapy of patients with APL for medical and economic reasons.

Adult↗
PubMed1995

Temporal changes in myocardial perfusion patterns in patients with reperfused anterior wall myocardial infarction. Their relation to myocardial viability.

BACKGROUND: Several studies demonstrated ischemic microvascular damage in patients with acute myocardial infarction (AMI). In this study, myocardial contrast echocardiography (MCE) was used to assess the temporal changes in myocardial perfusion after reflow and to investigate the relation between MCE findings and myocardial viability. METHODS AND RESULTS: MCE was performed with the intracoronary injection of sonicated microbubbles before and shortly after coronary reflow and 1 month later in 45 patients with anterior wall AMI. MCE before reflow was analyzed to determine the risk area as an area of contrast defect in the apical long-axis view. MCE images after reperfusion were analyzed to determine peak contrast intensity, which should be in proportion to the concentration of microbubbles within the microvasculature and in the infarcted and normal myocardium, and the ratio of these (PI ratio) was used to assess microvascular integrity. Areas of residual contrast defect were expressed as a ratio to those of left ventricular myocardial (RCD ratio) to assess the spatial extent of the MCE "no reflow." Regional wall motion (RWM, SD per chord) in the territory of the left anterior descending coronary artery was determined by the centerline method in both the acute and late stages. Although the PI ratio was extremely low shortly after coronary reflow, it increased in the late stage of AMI with the improvement in regional contractile function (RWM, -3.2 +/- 0.5 versus -2.6 +/- 1.0, P < .01; PI ratio, 0.44 +/- 0.25 versus 0.60 +/- 0.29, P < .01). Reduction in the RCD ratio was observed even in 15 patients with MCE no reflow in the acute stage (0.33 +/- 0.09 versus 0.16 +/- 0.11, P < .01). Then we investigated the relation between residual contractile function and microvascular integrity in the late stage. A significant correlation was found between the PI ratio and RWM (r = .73, P < .001) in the late stage of the AMI. CONCLUSIONS: (1) Recovery from ischemic microvascular damage is generally observed in the late stage of AMI in association with improvement in myocardial contractile function. The degree of improvement in contractile function and microvascular integrity, however, varies among patients. (2) Contrast peak intensity in the late stage of infarction may provide a useful estimate of myocardial viability.

Adult↗
PubMed1995

Environmentally induced changes in peripheral benzodiazepine receptors are stressor and tissue specific.

The stress-induced changes in peripheral benzodiazepine receptors (PBR) can be observed in a number of different tissues, depending upon the nature and chronicity of the aversive experience. In addition, virtually all stress procedures that cause rapid changes in PBR simultaneously increase the physical activity or metabolic rate of the subjects. The present study analyzed the contributions of rapid alterations in activity or metabolic rate with and without aversive stimulation and their subsequent impact on PBR. Mechanically induced increases in activity by forced running stress results in a significant reduction in [3H]Ro 5-4864 binding to PBR in olfactory bulb, opposite to the PBR changes in this tissue following forced cold-water swim stress. Pharmacological induction of increased locomotor activity as well as metabolic rate by d-amphetamine causes a significant increase in cardiac PBR binding, again, opposite to the response typically observed following inescapable shock stress. Finally, administration of the anxiogenic beta-carboline, FG-7142, causes increases in both hippocampus and adrenal gland PBR binding reminiscent of acute noise stress exposure. These experiments demonstrate that increased locomotor activity or metabolic rate alone is not a necessary and sufficient condition for previous stress-induced changes in PBR. Conversely, increased metabolic rate coupled with an aversive stimulus appears to be an important factor for inducing stress-like changes in PBR. This data, coupled with previous reports, suggests that rapid alterations in these sites are stressor and tissue dependent. Finally, we propose that the PBR may be involved in many aspects of the stress response including: a) a blowarning system in adrenal gland, b) participation in stress-induced hypertension via renal PBR, and c) a modulator of stress-induced immunosuppression and subsequent recovery of function or recuperation by actions on immune cells.

Animals↗
PubMed1995

A truncated K-sam product lacking the distal carboxyl-terminal portion provides a reduced level of autophosphorylation and greater resistance against induction of differentiation.

The K-sam gene was originally cloned from KATO-III human gastric cancer cells and is identical to the bek or keratinocyte growth factor (KGF) receptor (KGFR) or fibroblast growth factor receptor 2 gene. K-sam generates several variant transcripts by alternative splicing, and the most abundant K-sam transcript in KATO-III cells was cloned as the K-sam-IIC3 cDNA, which has the KGF-binding motif and a short carboxyl terminus lacking a putative phospholipase C-gamma 1 association site, Tyr-769. The K-sam-IIC3 cDNA was distinct from the K-sam-IIC1 cDNA, which was the same as the previously reported KGFR cDNA. The K-sam-IIC1 product contains a long carboxyl terminus with Tyr-769. K-sam-IIC3 showed greater transforming activity in NIH 3T3 cells than did K-sam-IIC1, and in gastric cancer cell lines in general, the level of K-sam-IIC3 mRNA was greater than that of K-sam-IIC1 mRNA. Here we report that the K-sam-IIC3 product was less autophosphorylated than the K-sam-IIC1 product in NIH 3T3 transfectants. K-sam-IIC3-transfected keratinocytes showed a stronger mitogenic response to KGF than did K-sam-IIC1 transfectants. Moreover, K-sam-IIC3-transfected L6 myoblast cells hardly differentiated when cultured in differentiation-inducing medium and growth was not significantly affected, while K-sam-IIC1 transfectants showed a differentiated phenotype with a reduced growth rate. These data indicate the difference in the signal transduction mediated by two KGFR-type K-sam variants generated by alternative splicing which might be involved in certain differentiation and carcinogenesis scenarios.

Alternative Splicing↗
PubMed1995

[Prostaglandin E1 bladder instillations for late-onset hemorrhagic cystitis following allogeneic bone marrow transplantation].

Between July, 1990 and March, 1994, 31 patients with hematological malignancies or severe aplastic anemia underwent allogeneic bone marrow transplantation (BMT) at the Second Department of Internal medicine, Chiba University Hospital. Among the 29 evaluable patients who survived over 100 days after transplant, 11 patients (37.9%) developed late-onset hemorrhagic cystitis with a median time of onset of 57 days (range 11-205) from BMT. Adenovirus type 11 was isolated from the urine of 4 patients. Five patients recovered with fluid hydration and forced diuresis, while 6 patients had persistent gross hematuria with clot formation, 5 of whom also developed hydronephrosis. Seven-day courses of 500 micrograms prostaglandin E1 (PGE1) bladder instillations was initiated to control hematuria in these 6 patients. Complete resolution of gross hematuria was achieved in 4, and partial response with decreased clot formation and partial clearing of the urine was observed after 4 of 9 courses of the treatment. Although all patients experienced bladder spasm or lower abdominal pain during the PGE1 instillations, these symptoms were manageable with sedative drugs and morphine. No systemic side effect was apparent. PGE1 bladder instillations is a safe and useful treatment for severe, life-threatening late-onset hemorrhagic cystitis after allogeneic BMT.

Administration, Intravesical↗
PubMed1994

Synthesis and antimicrobial activity of novel 3-[(aminopyrimidiniumyl)thio]methyl cephalosporins.

A series of novel cephalosporin compounds which have 3-[(aminopyrimidiniumyl)thio]methyl substituents was synthesized. They show high antimicrobial activity against various bacterial species including Pseudomonas aeruginosa. Structure-activity relationships with various thiopyrimidines, thiopyrimidiniums, bicyclic thiotriazolopyrimidiniums, and bicyclic thioimidazolopyrimidiniums as 3'-substituents were also studied; cephalosporins with quarternized pyrimidinium moieties have better antimicrobial activities than neuteral pyrimidine cephalosporins, and stabilization of the positive charge on the pyrimidinium moieties is essential for better activity. According to semiempirical PM3 calculations, amino and alkylthio substituents on the pyrimidinium rings play a major role in charge stabilization and delocalization.

Cephalosporins↗
PubMed1994

Preferential expression of the third immunoglobulin-like domain of K-sam product provides keratinocyte growth factor-dependent growth in carcinoma cell lines.

Previously, we identified an amplified gene in a stomach cancer cell line, KATO-III, and designated it K-sam. This gene was later found to be identical with a gene for a receptor tyrosine kinase, bek/FGFR2. One of the characteristics of the K-sam gene is structural diversity of its transcripts; K-sam complementary DNA (cDNA) cloned from human brain (K-sam-I) has a completely different sequence at the third extracellular immunoglobulin-like domain as compared to that of the K-sam cDNA derived from KATO-III cells (K-sam-II). Recent study has revealed that this difference signifies a differential ligand affinity; the receptor encoded by the K-sam-I cDNA has a high affinity for basic fibroblast growth factor (bFGF), while the K-sam-II cDNA corresponds to a receptor with the high affinity for keratinocyte growth factor (KGF). Reverse transcription-polymerase chain reaction and RNA blot analysis showed that the K-sam-II-type transcript was present in carcinoma cell lines but not in any of the sarcoma cell lines examined. The K-sam-I-type transcript was expressed in both carcinoma and sarcoma cell lines. Furthermore, KGF enhanced the DNA synthesis of the esophageal cancer cells, TE-1, in a dose-dependent manner, while the effect of bFGF was not substantial. In contrast, the glioblastoma cell line, A-172, that expressed the bFGF receptor showed a mitogenic response to bFGF but not to KGF. These data suggest that KGF is a growth factor used preferentially in cancer cells, and this preference is based on the presence of the K-sam-II-type receptor in carcinoma cells but not in sarcoma cells due to alternative splicing.

Base Sequence↗
PubMed1994

Dobutamine stress echocardiography predicts reversible dysfunction and quantitates the extent of irreversibly damaged myocardium after reperfusion of anterior myocardial infarction.

OBJECTIVES: This study was designed to evaluate dobutamine stress echocardiography in identifying reversible dysfunction and assessing the extent of irreversibly damaged myocardium early in acute myocardial infarction. BACKGROUND: Several experimental and clinical studies have suggested that dobutamine enhances contractile function of stunned or hibernating, or both, myocardium. It is important for clinical strategy to predict the magnitude of improvement in myocardial function early in acute myocardial infarction. METHODS: We studied 21 patients with a reperfused first anterior myocardial infarction. Two-dimensional echocardiography was performed before and during dobutamine infusion (10 micrograms/kg body weight per min) at a mean of 3 days after the infarction. Follow-up echocardiography was performed at a mean of 25 days later. To assess segmental wall motion, we divided the left ventricle into 17 segments and assigned a wall motion abnormality score: 3 = dyskinesia or akinesia; 0 = normal. Improvement in wall motion was indicated by a decrease of at least one grade in segmental score. For quantitative assessment, the ratio of endocardial length showing dyskinesia or akinesia to a left ventricular endocardial length (akinetic length ratio) was determined in the apical long-axis view at each stage. RESULTS: Sensitivity and specificity of dobutamine infusion in detecting improvement in wall motion at follow-up echocardiography were 83% (55 of 66 segments) and 86% (43 of 50 segments), respectively. Excellent correlation was found (r = 0.93, p < 0.001; absolute difference [mean +/- SD] 0.03 +/- 0.05) between the akinetic length ratios measured during dobutamine infusion and in the late convalescent stage. CONCLUSIONS: In the early stage of acute myocardial infarction, low dose dobutamine stress echocardiography provides a useful method for predicting reversible dysfunction with excellent sensitivity and specificity and can also be used to quantitate the extent of irreversibly damaged myocardium.

Adult↗
PubMed1994

Partial splenic embolization for the treatment of chronic idiopathic thrombocytopenic purpura.

OBJECTIVE: The purpose of this study was to assess the effectiveness of partial splenic embolization in the treatment of chronic idiopathic thrombocytopenic purpura. SUBJECTS AND METHODS: Twenty-six patients with chronic idiopathic thrombocytopenic purpura underwent partial splenic embolization and were followed up for 6-61 months. The condition was refractory to steroids in 20 of 26 patients. The other six patients, in whom a response to steroids was shown, could not be withdrawn from steroid therapy because their platelet counts decreased with any decrease in steroid dose. Five of 26 patients underwent splenectomy after partial splenic embolization, and the other patients were followed up without medical treatment until platelet counts decreased below 3 x 10(10)/l. The therapeutic effect of partial splenic embolization was defined on the basis of the platelet count at the last follow-up after partial splenic embolization: complete response, greater than 10 x 10(10)/l; partial response, 5 x 10(10)/l to 10 x 10(10)/l; and no response, less than 5 x 10(10)/l without medication. RESULTS: Partial splenic embolization brought a complete response in seven (33%) of 21 patients, a partial response in eight (38%), and no response in six (29%). In four of five patients, who later underwent splenectomy, response to partial splenic embolization was coincident with the response to splenectomy. No serious complications occurred, but minor complications such as abdominal pain, fever, and nausea were observed in most patients. CONCLUSION: This study suggests that partial splenic embolization might be useful as an alternative to splenectomy in the treatment of chronic idiopathic thrombocytopenic purpura.

Adult↗