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Biomedical subjects

Y Onozawa

Publications and source records attributed to Y Onozawa.

At least 19 recordsLinked to original sources
PubMed2001

Differential effects of angiotensin II versus endothelin-1 inhibitions in hypertrophic left ventricular myocardium during transition to heart failure.

BACKGROUND: In view of their mutual crosstalk, the roles of angiotensin II (Ang II) and endothelin-1 (ET-1) in the myocardium are assumed to be synergistic and supplemental. METHODS AND RESULTS: In the phase of compensated left ventricular (LV) hypertrophy of Dahl salt-sensitive rats, Ang II peptide and the ACE mRNA in the LV were increased by 1.6- and 3.8-fold, respectively. In contrast, ET-1 peptide and the preproET-1 mRNA remained unchanged. In subsequent congestive heart failure (CHF), Ang II and ACE mRNA did not show further increases. But ET-1 and the mRNA were increased de novo by 5.3- and 4.1-fold, respectively. In ascending aorta-banded rats, the local activations of Ang II and ET-1 also showed a differential time course between LV hypertrophy and CHF. Long-term treatments of Dahl salt-sensitive rats with temocapril (an ACE inhibitor) and with bosentan (a mixed ET receptor blocker) equally improved long-term survival. Temocapril reduced the LV/body weight ratio and ameliorated LV fractional shortening. Conversely, although bosentan equally improved fractional shortening, it did not reduce the increase in LV mass. Combined treatment with these 2 drugs further ameliorated the animal's survival without additional decreases in systolic pressure. CONCLUSIONS: The pathophysiological roles in the myocardium during the transition to CHF differ qualitatively between Ang II and ET-1. Thus, long-term therapy with a combination of ACE inhibition and ET antagonism may provide a new approach for heart failure in humans.

Angiotensin II↗
PubMed2001

Adenovirus is a key pathogen in hemorrhagic cystitis associated with bone marrow transplantation.

Late-onset hemorrhagic cystitis (HC) is a well-known complication of bone marrow transplantation (BMT) that is mainly attributed to infection with BK virus (BKV) and adenovirus (AdV). From 1986 through 1998, 282 patients underwent BMT, and 45 of them developed HC. Urine samples tested positive for AdV in 26 patients, of which 22 showed virus type 11. Among patients who underwent allogeneic BMT, logistic regression analysis revealed acute graft-versus-host disease (grade, > or = 2) to be the most significant predictive factor for HC (P < .0001). In addition, a total of 193 urine samples regularly obtained from 26 consecutive patients who underwent allogeneic BMT were examined for BKV, JC virus (JCV), and AdV by means of polymerase chain reaction. Of patients without HC, approximately 30% of the specimens tested positive for BKV (58 samples) and JCV (55 samples), whereas 5 (3%) tested positive for AdV. Of the 3 samples obtained from patients with HC, the numbers of positive results for BKV, JCV, and AdV were 3, 1, and 1, respectively; the numbers of positive results increased to 14 of 17, 9 of 17, and 10 of 17, respectively, when we added another 14 samples obtained from 14 patients with HC (P < .0001, P = .026, and P < .0001, respectively). In conclusion, there was significant correlation between AdV and HC in the patients we studied.

Adenovirus Infections, Human↗
PubMed2001

Treatable subsets in cancer of unknown primary origin.

The purpose of this study was to investigate the treatable subsets in cancer of unknown primary origin (CUP). Fifty patients (27 males and 23 females; median age, 53 years) with CUP diagnosed between April 1992 and June 1999 were analyzed retrospectively. Of the 50 patients, 39 received chemotherapy: platinum-based in 31, non-platinum-based in 4, and clinical trials of new agents in 4. Of the 39 patients, 13 (33.3%; 95% confidence interval: 19.1 - 50.2%) showed objective responses, with 4 complete responders. Patients with poorly differentiated carcinomas in whom beta-subunit of human chorionic gonadotropin (beta-HCG) was elevated more than 10 mIU / ml and female patients with peritoneal adenocarcinomatosis achieved high response rates (83.3% and 80%, respectively) with platinum-based chemotherapy, as compared with only a 15.3% response rate in the remaining patients. Platinum-based chemotherapy provided promising results in patients with poorly differentiated carcinomas and in female patients with peritoneal adenocarcinomatosis. Significantly elevated serum levels of beta-HCG in patients with poorly differentiated carcinoma might predict a better response to platinum-based chemotherapy. However, the investigation of novel chemotherapeutic approaches is warranted for other groups of patients with CUP.

Adenocarcinoma↗
PubMed2000

Dose-escalation study of CHOP with or without prophylactic G-CSF in aggressive non-Hodgkin's lymphoma.

BACKGROUND: CHOP is accepted as the gold standard for first line chemotherapy of aggressive non-Hodgkin's lymphoma (NHL). A dose-escalation study of CHOP was conducted to determine the maximal tolerated dose (MTD) and toxicity profile of CHOP at three-week intervals with or without prophylactic recombinant human granulocyte colony-stimulating factor (rHuG-CSF) in patients with aggressive NHL. PATIENTS AND METHODS: The doses of drugs were escalated from 50 mg/m2 to 70 mg/m2 for doxorubicin and from 750 mg/m2 to 2250 mg/m2 for cyclophosphamide, with conventional doses of vincristine and oral prednisolone. After the MTD was determined without rHuG-CSF, dose escalation was conducted with prophylactic rHuG-CSF. RESULTS: Thirty-three patients with NHL were enrolled into the study. The MTD without prophylactic rHuG-CSF was 70 mg/m2 of doxorubicin and 1250 mg/m2 of cyclophosphamide, with neutropenia as a dose-limiting toxicity. The MTD with prophylactic rHuG-CSF was 70 mg/m2 of doxorubicin and 2250 mg/m2 of cyclophosphamide. The overall response rate was 100% (76% complete response and 24% partial response). Progression-free survival and overall survival at five years were 45% and 66%, respectively. CONCLUSIONS: Significant dose escalation of doxorubicin and cyclophosphamide was feasible with prophylactic rHuG-CSF. The efficacy of dose-escalated CHOP should be compared with that of standard CHOP.

Adolescent↗
PubMed2000

Study of dose escalation and sequence switching of administration of the combination of docetaxel and doxorubicin in advanced breast cancer.

The objectives of the present study were to evaluate whether a schedule-dependent pharmacokinetic and/or pharmacodynamic interaction exists between two sequences of docetaxel and doxorubicin administration and to determine the maximal tolerated dose (MTD) of this combination. Patients with chemotherapy-naïve metastatic or recurrent advanced breast cancer were enrolled. In the crossover design, tandem dose escalation of docetaxel and doxorubicin was performed. Docetaxel, in doses ranging from 50-70 mg/m2, was administered for 1 h by drip infusion either just before or after a 5-min bolus i.v. injection of doxorubicin at dosages from 40-50 mg/ m2. The sequence of drug administration was switched after the first course in each patient, and the sequence of drug administration thereafter depended on the patient's choice. Twenty-five patients were initially assessable for toxicity. The MTD in the sequence of doxorubicin after docetaxel was 40 and 50 mg/m2, respectively, with the dose-limiting toxicity of neutropenia. On the other hand, the MTD of the sequence of docetaxel after doxorubicin was 70 and 50 mg/m2, respectively. The dose-limiting toxicities in this sequence were neutropenia and diarrhea. Duration of grade 4 neutropenia in the sequence of docetaxel followed by doxorubicin was significantly longer than that in the alternate sequence (P = 0.0062). However, there was no difference in pharmacokinetic parameters of docetaxel, doxorubicin, and doxorubicinol between the two sequences. The sequence of 50 mg/m2 doxorubicin followed by 60 mg/m2 docetaxel is recommended for subsequent clinical trials for practical reasons.

Adult↗
PubMed1999

Apoptosis during iron chelator-induced differentiation in F9 embryonal carcinoma cells.

We have previously demonstrated that three potent iron chelators, hinokitiol, dithizone and deferoxamine, induce differentiation of F9 embryonal carcinoma cells, as do other well-known morphogens such as retinoic acid (RA) and sodium butyrate (NaB). In this study, we compared the patterns of cell proliferation, cell death and cell cycle arrest during the process of differentiation induced by these five agents. When F9 cells were cultured with the agents at their individual differentiation-inducing concentrations, cell proliferation was rapidly inhibited by treatment with the iron chelators and NaB. In contrast, RA did not influence the rate of increase of cell number at the concentration of 1 microm. The three chelators also caused a marked reduction in cell viability, and the treated cells exhibited internucleosomal DNA fragmentation, whereas cells treated with NaB showed no apoptotic characteristics. RA induced apoptosis weakly at 1 microm and strongly at higher concentrations. In addition, all the iron chelators hindered cell cycle progression, resulting in an arrest at the G1-S interface or S phase. The phenomena observed in chelator-treated cells were considerably different from those in RA- or NaB-treated cells. It is concluded that the three iron chelators cause both severe apoptotic cell death and cell cycle arrest of proliferating F9 cells via cellular iron deprivation, and that this apoptotic change may be independent of the process of differentiation.

Animals↗
PubMed1999

[Clinical effects of combination therapy with cefozopran and tobramycin for severe infections in patients with hematologic diseases].

We studied clinical effect of a combination therapy with cefozopran (CZOP) and tobramycin (TOB) for infections in 80 patients with hematologic diseases in 15 institutes. Combined doses with CZOP 2 g and TOB 60-90 mg twice a day had been given intravenously. Of the 80 patients, 61 patients (42 with acute leukemia, 10 with malignant lymphoma, 3 with aplastic anemia, 2 with chronic myeloid leukemia, 2 with multiple myeloma, and 2 with myelodysplastic syndrome) were evaluable. Those consisted of 6 patients with septicemia, 49 with suspected septicemia, 3 with pneumonia, and 3 with other infections. Clinical efficacy by the treatment was excellent in 24, good in 17, fair in 9, and poor in 11 patients, and the overall efficacy rate including excellent and good was 67.2%. Microbiologically, 5 of the 6 patients with septicemia (1 coagulase negative Staphylococcus, 2 S. pneumoniae, 1 S. oralis, and 1 E. coli) were responded. The efficacy rate in patients with severe granulocytopenia showing 100/microliter or lesser neutrophil counts during the drug administration was 57.1% (12/21). Side effects and abnormal changes of clinical laboratory findings were observed in 5 patients, and 16 patients, respectively, but most of them were mild. The findings above suggested that the combination therapy with CZOP and TOB is useful as an empiric therapy for severe infections in patients with hematologic diseases.

Adult↗
PubMed1998

Invasive infection due to Trichosporon cutaneum in patients with hematologic malignancies.

BACKGROUND: Invasive infection due to Trichosporon is a rare but often fatal disease in immunocompromised patients. In this study, data on patients with hematologic malignancies who had an invasive infection due to Trichosporon diagnosed at the Tokyo Metropolitan Komagome Hospital in Tokyo, Japan, were analyzed. METHODS: Positive blood cultures obtained between 1986 and 1996 were reviewed. Medical records of all patients who were positive for Trichosporon in their blood culture or autopsy material were then examined. RESULTS: A total of nine patients with hematologic malignancies were reported positive for Trichosporon cutaneum in their blood culture or at the time of autopsy. The average age was 52 years, and all patients except 2 had acute leukemia. All 8 patients with positive blood cultures were neutropenic, and the average duration of neutropenia before the positive blood cultures were obtained was 43 (range, 0-101) days. For prophylaxis of fungal infection, eight patients were kept in a laminar air flow room and also received nebulization with amphotericin B. Five patients received oral amphotericin B. All 9 patients died of the infection an average of 9 days after their blood cultures turned positive. Minimal inhibitory concentrations were evaluated in six available strains obtained from the patients. They were all resistant to amphotericin B and azoles. CONCLUSIONS: More effective antifungal agents are required for the treatment of infections with this organism.

Adult↗
PubMed1998

Response-oriented individualized induction therapy followed by intensive consolidation and maintenance for adult patients with acute lymphoblastic leukemia: the ALL-87 study of the Japan Adult Leukemia Study Group (JALSG).

The Japan Adult Leukemia Study Group conducted the ALL-87 study to determine whether response-oriented induction therapy and intensive consolidation and maintenance/intensification therapies could increase complete remission (CR) rate and survival in adult acute lymphoblastic leukemia (ALL). Of 121 patients registered, 116 were evaluated. Patients' ages ranged from 15 to 72 years (median, 38 years). Induction therapy, which consisted of doxorubicin, vincristine, cyclophosphamide, L-asparaginase and prednisolone, was given in a response-oriented individualized fashion. Patients were randomly allocated either to receive or not, intrathecal chemotherapy on day 8 of the induction therapy. Complete remission (CR) was obtained in 97 (83.6%) patients (90.2%) in patients of less than 50 years of age and 67.6% in patients 50 years of age or older). At a median follow-up period of 65 months, the predicted 6-year overall survival and event free survival (EFS) rates of 116 patients were 23.4 and 20.0%, respectively. Predicted 6-year survival and disease-free survival (DFS) rates of 97 CR patients were 28.2 and 24.5%, respectively. By multivariate analysis, patients under 40 years of age (P = 0.002) or those with a platelet count of more than 100,000/microliters (P = 0.004) were significant favorable prognostic factors for obtaining CR, and days to CR less than 50 (P = 0.003), patients under 50 years of age (P = 0.005) were significant favorable factors for longer DFS. There was no significant difference in CR rates and DFS between the two randomized groups according to the intrathecal chemotherapy on day 8. Response-oriented induction therapy produced a high CR rate, but fairly intensive consolidation and maintenance/intensification chemotherapies resulted in only a marginal effect on DFS in adult ALL. Although age is one of the most important prognostic factors in ALL, the outcome was unsatisfactory even in younger adult patients using chemotherapeutic regimen employed in this study.

Adolescent↗
PubMed1998

Incidence and influence of GB virus C and hepatitis C virus infection in patients undergoing bone marrow transplantation.

Markers of GB virus C (GBV-C) and hepatitis C virus (HCV) were sought in 80 patients before and after they underwent BMT in a metropolitan hospital in Tokyo between 1990 and 1996. RNA of GBV-C was detected in 14 (18%) patients before BMT. Of the 55 patients who had been transfused, 14 (25%) possessed GBV-C RNA at a frequency significantly higher than in the 25 untransfused patients who were all negative (P < 0.01). HCV RNA was detected in three of the 55 (5%) transfused patients, but in none of the 25 untransfused patients. Sera at 3 months after BMT were available for 57 patients. GBV-C RNA persisted in all 10 patients who were infected before BMT, while it was detected in five of the remaining 47 (11%) patients who were not. However, persistent and/or ongoing GBV-C infection had no appreciable influence on patient morbidity or mortality. Two of the 57 patients were positive for HCV RNA before BMT and this persisted after BMT in both. HCV RNA became positive in eight of the remaining 55 (15%) patients who were negative before BMT. Of the 14 patients who received transfusions screened by the first-generation test at BMT, seven (50%) became positive for HCV RNA, a rate significantly higher than the one of 41 (2%) patients who received transfusions screened by the second-generation test (P < 0.001). These results indicate that BMT patients are at increased risk of GBV-C infection transmitted by transfusions received before and at the time of BMT, and that the risk of HCV infection has decreased after the implementation of the second-generation anti-HCV test.

Adolescent↗
PubMed1998

Utility and safety of Hickman catheters for venous access after bone marrow transplantation.

Hickman catheters are useful for vascular access after bone marrow transportation because they can handle large volume and allow for easy transfusions and blood drawing through wide double lumens making it easier to case for patients under sterile conditions in a clean room. However, the safety of Hickman catheters as compared to Silastic catheters in marrow transplants has never been discussed. We therefore retrospectively reviewed the complications of two catheters in 71 allogeneic bone marrow transplant recipients between September 1986 and August 1994. The complication and infection rates of Hickman catheters were 0.21 and 0.09 per 100 device-life days, and rate of temperature >38 degrees C during leukocytopenia (<1,000 white blood cells) was 0.18. These rates were not different from those of Silastic catheters suggesting that Hickman catheters are safe and acceptable in marrow transplantation. The benefits and drawbacks of Hickman catheters relevant to catheter choice were also discussed.

Adolescent↗
PubMed1998

[Hemolytic uremic syndrome after bone marrow transplantation].

One hundred and thirteen patients who underwent autologous or allogeneic bone marrow transplantation (BMT) were investigated for the subsequent development of hemolytic uremic syndrome (HUS). HUS developed in seven patients (four males and three females, five acute lymphocytic leukemia (ALL), one acute myelogenous leukemia, one non-Hodgkin's lymphoma) between 36-196 days after BMT. Four patients were recipients of autologous BMT and three were those of allogeneic BMT. Six patients were preconditioned with the regimens including fractionated total body irradiation (TBI). ALL and preconditioning regimen with TBI were suspected to be the risk factors for the development of HUS. Cyclosporin A (CSP) administration was discontinued in three patients who had been given CSP for graft-versus-host disease prophylaxis. Predonisolone was given to the three patients and plasma exchange was performed in one patient. Both hemolytic anemia and thrombocytopenia were resolved in virtually all patients, while creatinine elevation has persisted along with hypertension in one patient.

Adolescent↗
PubMed1998

[Effective splenectomy in a patient with HIV-associated thrombocytopenia].

A 31-year-old man presented with a 3-month history of petechial hemorrhages. Physical examination revealed no splenomegaly. The patient's platelet count was 1.0 x 10(9)/l and bone marrow aspiration showed an elevated number of megakaryocytes. A diagnosis of HIV-associated thrombocytopenia was made on the basis of HIV seropositive results. The CD4 cell count was 400 x 10(6)/l. No opportunistic infections indicating AIDS were detected. Initially the patient was treated with predonisolone, but showed only a transient response. He also failed to respond to zidovudine, lamivudine, or indinavir. Following splenectomy, however, his platelet count rose above 80 x 10(9)/l (normal level: 150-350 x 10(9)/l).

Adult↗
PubMed1997

Comparison of cytomegalovirus (CMV) antigenemia and CMV in bronchoalveolar lavage fluid for diagnosis of CMV pulmonary infection after bone marrow transplantation.

A comparative cytomegalovirus (CMV) diagnostic study was carried out on 30 bone marrow transplant patients. Forty-three bronchoalveolar lavage fluid (BALF) samples from these patients were examined for CMV by viral culture, polymerase chain reaction (PCR), shell vial and cytology. In parallel, peripheral blood samples were subjected to CMV antigenemia assay. CMV was detected in 12 (27.9%) of the 43 BALF samples (10 samples in viral culture, 10 samples in PCR, eight samples in shell vial and three samples in cytology). The CMV antigenemia assay yielded a positive result for six samples. The rates of agreement between results of the CMV antigenemia assay and results of each of the BALF tests were as follows: 81.4% with viral culture, 76.7% with PCR, 86.0% with shell vial, and 88.4% with cytology. Although the sensitivity of the CMV antigenemia assay was inferior to the sensitive tests of BALF samples, statistically significant correlations were demonstrated between the CMV antigenemia assay, viral culture, shell vial and cytology. Although the CMV antigenemia assay was shown to be useful for detection of CMV, it may be necessary to confirm not only the sensitivity but also the specificity of this method for prevention of CMV disease after BMT.

Adolescent↗
PubMed1997

Microangiopathy without hemolysis in a patient following allogeneic bone marrow transplantation.

Thrombotic microangiopathy (TMA) is one of the complications of bone marrow transplantation (BMT) which includes hemolytic uremic syndrome (HUS) and thrombotic thrombocytopenic purpura (TTP). Red cell fragmentation is the most consistent laboratory finding. We present a case of TMA with endothelial damage but without the signs of hemolysis. The patient was not receiving cyclosporine. Partial activation of platelets was also observed. This case represents a new form of TMA in transplant recipients.

Adult↗
PubMed1997

Risk factors for hepatic veno-occlusive disease after bone marrow transplantation: retrospective analysis of 137 cases at a single institution.

One hundred and thirty-seven consecutive patients who received bone marrow or peripheral blood stem cell transplantation were studied retrospectively to identify the risk factors for hepatic veno-occlusive disease (VOD). Of the 137 recipients, twenty (14.6%) patients were diagnosed with VOD using the McDonald's criteria. In these 20 patients with VOD, we analyzed various clinical parameters, including age, sex, HLA status, conditioning regimen, irradiation, immunosuppressive agents, mode of transplantation, history of hepatic dysfunction, pre-transplant hepatic and renal function, infectious episodes, antibiotics use, and serum viral titers. A history of hepatic dysfunction and low levels of pseudocholinesterase before transplantation were found to be statistically significant (P = 0.04 and 0.04). Low levels of pseudocholinesterase were significant by multivariate analysis using the logistic regression model (P = 0.02). These results suggest that pseudocholinesterase levels before transplant are important markers of VOD in patients receiving BMT.

Adolescent↗
PubMed1997

Effects of cyclosporin A on hepatitis C virus infection in bone marrow transplant patients. Bone Marrow Transplantation Team.

The hepatitis C virus (HCV) infection has, in general, been considered not to affect liver function severely during the course of bone marrow transplantation (BMT) except for late hepatitis which coincided with a decrease in immunosuppressive therapy. We examined serial sera of two patients with positive HCV antibody who underwent allogeneic BMT and found that while the dose of cyclosporin A tapered off, the serum concentration of HCV core protein increased before the occurrence of hepatitis. This suggests that viral reactivation and growth might be one of the important mechanisms of hepatitis after BMT in patients with positive HCV antibody.

Adult↗