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Biomedical subjects

Y Takemoto

Publications and source records attributed to Y Takemoto.

At least 109 records · Page 6Linked to original sources
PubMed1998

The levels of soluble P-selectin, von Willebrand factor and thrombomodulin in patients with neurological complications after allogeneic bone marrow transplantation.

We encountered two patients with uncommon neurological manifestations after allogeneic bone marrow transplantation (BMT), which occurred with rapid elevation of the leukocyte count at engraftment. Both patients then developed severe acute graft-versus-host disease (GVHD). To investigate the pathogenesis, we measured the levels of soluble P-selectin, von Willebrand factor (vWF) and thrombomodulin (TM), which reflect endothelial damage. The P-selectin, vWF and TM levels in the patients with (n=2) and without (n=5) neurotoxicity were, respectively, 168.5+/-52.5 ng/ml vs 27.7+/-3.9 ng/ml, 6.7+/-0.15 FU/ml vs 3.42+/-0.41 FU/ml and 459+/-37% vs 189.4+/-32.4% (mean+/-s.d.). All three parameters were much higher in the patients with neurological complications. These results suggest that neurotoxicity after BMT may be related to endothelial damage.

Adult↗
PubMed1998

Significance of trilineage myelodysplasia in de novo acute myeloid leukaemia during remission rather than at diagnosis.

Patients with trilineage myelodysplasia (TMDS) in de novo acute myeloid leukaemia (AML) at diagnosis and remission were clinically evaluated between 1983 and 1996. AML with TMDS (AML/TMDS) was observed in 20 (12%) of 162 patients with de novo AML at diagnosis. Complete remission (CR) was achieved with combination chemotherapy in 12 (67%) of 18 AML/TMDS cases. This CR rate was relatively worse than the rate of 78% (106/136 cases) of AML without TMDS, but this difference was not significant. Disease-free survival curves also showed no difference between AML/TMDS and AML without TMDS. During remission, eight (67%) of 12 AML/TMDS cases had myelodysplastic remission marrow (AML/MRM). AML/MRM was also seen in seven (7%) of 106 AML cases without TMDS. The actuarial disease-free survival was significantly lower in AML/MRM than in AML without MRM (P = 0.0003). All of the AML/MRM cases exhibited early leukaemic relapse; median remission duration was only 9 months. Clonal changes occurred in two cases of AML/TMDS and five cases of AML/MRM at the time of relapse. These findings suggest that TMDS during remission predicts a poorer prognosis and early leukaemic relapse when compared with the absence of TMDS.

Acute Disease↗
PubMed1998

Lixelle adsorbent to remove inflammatory cytokines.

A beta2-microglobulin (beta2M) selective adsorbent (Lixelle) for direct hemoperfusion has been used for the treatment of hemodialysis patients with the long-term complication of dialysis related amyloidosis (DRA), but there is no significant correlation between the serum level of beta2M and the occurrence of DRA. Inflammatory cytokines such as interleukin (IL)-1, IL-6, and tumor necrosis factor alpha (TNFalpha) are related to the development of DRA. We studied the adsorptive rates of cytokines in vitro using the Lixelle adsorbent. The adsorptive rates were 98.5% for IL-1beta 98.0% for interleukin-1 receptor antagonist (IL-1RA), 82.9% for IL-6, 99.9% for IL-8, 31.2% for TNFalpha, and 46.1% for soluble TNF receptor (sTNFr), respectively. As the molecular weights of cytokines increase, the adsorptive rates decrease. The Lixelle column adsorbed beta2M and various inflammatory cytokines as well. Therefore, the removal of both beta2M and inflammatory cytokines may play an important role in the treatment of DRA.

Adsorption↗
PubMed1998

Association between angiotensin II receptor gene polymorphism and serum angiotensin converting enzyme (SACE) activity in patients with sarcoidosis.

BACKGROUND: Serum angiotensin converting enzyme (SACE) is considered to reflect disease activity in sarcoidosis. SACE activity is increased in many patients with active sarcoid lesions. The mechanism for the increased SACE activity in this disease has not been clarified. ACE insertion/deletion (I/D) gene polymorphism has been reported to have an association with SACE levels in sarcoidosis, but no evidence of an association between angiotensin II receptor gene polymorphism and SACE in this disease has been found. A study of the association of angiotensin II receptor gene polymorphisms with sarcoidosis was therefore undertaken. METHODS: ACE (I/D), angiotensin II type 1 receptor (AGTR1), and angiotensin II type 2 receptor (AGTR2) gene polymorphisms were investigated by polymerase chain reaction (PCR) and SACE levels were measured in three groups of patients: those with sarcoidosis or tuberculosis and normal controls. RESULTS: There was no difference in allele frequency of AGTR1 and AGTR2 polymorphism among the three groups. Neither AGTR1 nor AGTR2 polymorphisms were associated with sarcoidosis. SACE activity was higher in patients with sarcoidosis with the AGTR1 A/C genotype than in others. However, this tendency was not detected in patients with tuberculosis. CONCLUSIONS: The AGTR1 allele C is associated with high activity of SACE in patients with sarcoidosis. It is another predisposing factor for high levels of SACE in patients with sarcoidosis and is considered to be an independent factor from the ACE D allele for high levels of SACE in sarcoidosis. This fact could be one of the explanations for the increased SACE activity in sarcoidosis.

Analysis of Variance↗
PubMed1998

Umbilical arterial flow change during hemodialysis.

A pregnant woman was performed hemodialysis 3 times a week from early gestation. At 30 weeks of gestation, fetal growth and amniotic fluid volume were normal. We performed 3-hour hemodialysis 6 times a week. Cesarean section was performed at 38 weeks of gestation, she delivered a healthy neonate weighing 2575 g. During hemodialysis, we performed Doppler flow velocimetry on the umbilical artery. The resistance index revealed a remarkable decrease after 1.5 hour hemodialysis. But it recovered 3 hours of administration as well as after completion of treatment. We speculated this change in the resistance index of the umbilical artery was caused by transient maternal hypovolemia.

Adult↗
PubMed1998

Cytogenetic analysis of de novo acute myeloid leukemia with trilineage myelodysplasia in comparison with myelodysplastic syndrome evolving to acute myeloid leukemia.

Characteristics of karyotypes were analyzed in de novo acute myeloid leukemia (AML) with trilineage myelodysplasia (AML/TMDS) at initial diagnosis and compared with myelodysplastic syndrome (MDS) cases that had evolved to AML (MDS/AML). Abnormal karyotypes were seen in 11 of 19 patients with AML/TMDS and 13 of 16 MDS/AML cases. Trisomy 8 was observed in 3 AML/TMDS cases as a sole anomaly and was also present in 3 MDS/AML cases but not as a sole finding. Although MDS/AML frequently displayed monosomies or long-arm deletions of chromosome 5, 7 and 9, only one case exhibited long-arm deletion (of chromosome 7) in AML/TMDS. Two or more chromosome aberrations were found in some cases in both groups. These findings suggest that AML/TMDS had passed through several preleukemic stages at diagnosis, as has been well documented in MDS and MDS/AML. Additionally, clonal evolution may have already occurred in AML/TMDS, as MDS transformed to AML is associated with clonal evolution.

Acute Disease↗
PubMed1998

[Monitoring of CMV infection after bone marrow transplantation].

Cytomegalovirus interstitial pneumonitis (CMV-IP) is one of the most serious complication after allogeneic stem cell transplantation. In the recent reports, ganciclovir administration have been shown to be effective for CMV infection by using more sensitive detection methods such as PCR method and antigenemia assay. The risk factors of CMV infection pretransplant time are known as follows, such as 1. unrelated donor marrow, 2. TBI, 3. anti thymocyte globulin, 4. T cell depletion and 5. HLA mismatched donor. After transplantation period 1. acute GVHD and 2. use of steroid hormone are important risk factors. It is necessary to select the effective strategy for the prevention of CMV-IP after stem cell transplantation.

Antigens, Viral↗
PubMed1998

Effects of YF476, a potent and selective gastrin/cholecystokinin-B receptor antagonist, on gastric acid secretion in beagle dogs with gastric fistula.

The antisecretory effects of the gastrin/cholecystokinin-B (CCK-B) receptor antagonist YF476 ((R)-1-[2,3-dihydro-2-oxo-1-pivaloylmethyl-5-(2'-pyridyl) 1H-1,4-benzodiazepin-3-yl]-3-(3-methylaminophenyl)-urea, CAS 155488-25-8) on secretagogue- and peptone-induced gastric acid secretion in beagle dogs with chronic gastric fistula were examined. Plasma gastrin concentrations were evaluated following introduction of peptone into the stomach. Intravenous administration of YF476 dose-dependently inhibited pentagastrin (1 microgram/kg/h)-induced gastric acid secretion, with an ED50 value of 0.0023 mumol/kg. In contrast, intravenous administration of YF476 (0.3 mumol/kg) did not affect histamine (15 micrograms/kg/ h)-induced gastric acid secretion. Oral administration of YF476, famotidine and omeprazole dose-dependently inhibited peptone (8%, 200 ml)-induced gastric acid secretion with ED50 values of 0.11, 0.76 and 4.28 mumol/kg, respectively. The antisecretory effect of YF476 was about 7 and 40 times more potent than that of famotidine and omeprazole, respectively. Plasma gastrin concentrations were increased by introduction of peptone. These results suggest that YF476 is an extremely potent and selective antisecretory drug and the endogenous gastrin plays an important role in peptone-induced gastric acid secretion in dogs.

Animals↗
PubMed1998

[Phase II study of KRN8602 (MX2) for malignant lymphoma].

We performed a clinical phase II study of KRN8602, a new anthracycline derivative, for relapsed or recurrent malignant lymphoma. KRN8602 was given at doses of 12-15 mg/m2 for 3 consecutive days, repeating every 3-4 weeks. Among 44 patients entered into the study, 36 were evaluable for safety, and 35 were evaluable for efficacy. The response rate was 18.2% (6PR/33) for non-Hodgkin's lymphoma and 0% (0/2) for Hodgkin's disease. Major toxicities were bone marrow suppression and gastrointestinal toxicity. Leukopenia was observed in 77.8%, thrombocytopenia in 44.4%, hemoglobin decrease in 44.4%, nausea and vomiting in 94.4% and anorexia in 80.6%. However, all toxicities were clinically manageable.

Anorexia↗
PubMed1998

[Early phase II study of KRN8602 (MX2), a novel anthracycline derivative for acute leukemia].

We performed an early phase II study of KRN8602, a new anthracycline derivative for refractory or relapsed acute leukemias. KRN8602 was given at a dose of 15 mg/m2 for 3 to 5 consecutive days, repeating every 3-4 weeks. Among 53 patients entered in the study, 51 were evaluable for safety, and 46 were evaluable for efficacy. The response rate at schedules of 3 and 4 consecutive days was 9.1% (1 PR/11), while that at a schedule of 5 consecutive days was 22.9% (3 CR + 5 PR/35). With the 5 consecutive day schedule, the response rates were 21.4% (1 CR + 2 PR/14) for acute myelogenous leukemia and 29.4% (2 CR + 3 PR/17) for acute lymphocytic leukemia, but no response was observed in 4 patients with blastic crisis of chronic myelogenous leukemia. Major toxicities were nausea/vomiting and anorexia, however, all these toxicities were clinically manageable. From these results it is concluded that KRN8602 is effective against acute leukemias, and the optimal dose is 15 mg/m2 for 5 consecutive days.

Adult↗
PubMed1997

Aberrant TCR-mediated signaling in CD45-null thymocytes involves dysfunctional regulation of Lck, Fyn, TCR-zeta, and ZAP-70.

CD45 is a transmembrane phosphotyrosine phosphatase expressed on all nucleated hemopoietic cells. Targeting of CD45 exon 9 has generated a mouse line completely lacking CD45 expression (CD45-null) in which there are severe abnormalities in T cell development. Defects in TCR-mediated signals underlying these abnormalities have now been investigated using CD45-null T cells. No T cell proliferation was detected in response to a CD3 mAb. In thymocytes the p56(lck) and p59(fyn) tyrosine kinases were hyperphosphorylated, and p56(lck) was in its inactive conformation. Both basal and TCR-stimulated tyrosine phosphorylation of TCR-zeta and CD3-epsilon were much reduced, and TCR stimulation induced an abnormal p18 phosphoisomer of TCR-zeta previously noted in T cells stimulated by altered peptide ligands. These defects were associated with the failure of ZAP-70 kinase recruitment to the TCR-zeta chain. TCR coupling to the tyrosine phosphorylation of several proteins, including HS1 and p120(cbl), was also much reduced. However, TCR-induced signaling was not ablated, and significant inositol phosphate and calcium signals were observed in CD45-null thymocytes. Our molecular analysis suggests that the threshold for TCR signal transduction is greatly increased in CD45-null T cells, thus explaining the profound defects in thymic development.

Animals↗
PubMed1997

Case-control study of leukemia and diagnostic radiation exposure.

A case-control study of leukemia and diagnostic X-ray exposure was conducted by a multi-institution co-operative study group. The subjects were 134 patients with acute myelogenous leukemia, 57 with chronic myelogenous leukemia, 56 with acute lymphocytic leukemia and 50 with myelodysplasia syndrome, who were between 15 and 79 years old, and diagnosed at one of 27 hospitals between September 1993 and August 1995. The controls were 479 first-visit patients seen at eight of these 27 hospitals. History of diagnostic X-ray tests between 1982 and 1991 was determined by an anonymous self-administered questionnaire. The total relative dose of radiation exposure was calculated by summing the products of given weights and frequencies of each test. The relative risk was 0.83 (95% confidence interval (C.I.), 0.58-1.19) for relative dose of 10-30 (equivalent to 4-11 times of UGI series), 0.76 (0.48-1.20) for relative dose of 30 or more (more than 12 times of UGI series), when compared with relative dose of 0-10 (0-3 times of UGI series). Analysis according to type of leukemia revealed that only acute myelogenous leukemia had an estimated relative risk above unity (1.08, 95% C.I. 0.69-1.69, for relative dose 10-30). This study did not support the hypothesis that diagnostic X-ray tests increases leukemia risk.

Adolescent↗
PubMed1997

Correlation between immunological abnormalities and prognosis in myelodysplastic syndrome patients.

Immunological abnormalities (IA) are frequently observed in patients with myelodysplastic syndromes (MDS). Although there have been a number of analyses of the prognostic factors, there have been few studies, if any, to determine whether IA affects prognosis. We investigated the prognosis of 153 MDS patients with or without IA who were treated at a single Japanese institute for 10 years. Nineteen of 153 patients (12%) developed autoimmune disorders. One hundred of 153 patients (63%) had an abnormality in at least one immunological laboratory test. Hypergammaglobulinemia was found in 50 of 128 (39%) patients tested, hypogammaglobulinemia was observed in 10 of 128 (8%), positivities of antinuclear antibody, RA factor. DNA antibody, and direct antiglobulin test were observed in 30%, 14%, 7% and 12%, respectively, and a CD4/CD8 ratio < 1 was observed in 20%. There was no significance in the distribution of age, MDS subtype, or sex between patients with and without IA. The survival of MDS patients without IA was significantly better than that of patients with IA, and the survival of patients with a CD4/CD8 ratio > 1 was also significantly superior to the survival of those with an inverted CD4/CD8 ratio. Patients with IA tended to die of infection or leukemic progression in comparison with those without IA, suggesting that IA may be associated with susceptibility to opportunistic infection and disease progression.

Adult↗
PubMed1997

YM022, a potent and selective gastrin/CCK-B receptor antagonist, inhibits peptone meal-induced gastric acid secretion in Heidenhain pouch dogs.

We examined the affinity of YM022, a potent and selective gastrin/CCK-B receptor antagonist, for canine gastrin/CCK-B and CCK-A receptors and the effects of YM022 on secretagogue- and peptone meal-induced acid secretion in the denervated, surgically separated (Heidenhain) canine gastric pouch model in comparison with those of famotidine, an H2-receptor antagonist, and atropine. YM022 inhibited the binding of [(125)I]CCK-8 and [(3)H]devazepide to canine gastrin/CCK-B and CCK-A receptors, with IC50 values of 0.73 and 136 nM, respectively. Intravenous YM022 dose-dependently inhibited pentagastrin- and peptone meal-induced acid secretion with ED50 values of 0.0261 and 0.0654 micromol/kg, respectively, without affecting histamine- or methacholine-induced acid secretion. Famotidine inhibited acid secretion induced by all stimulants, while atropine inhibited the acid secretion induced by every stimulant except histamine. These results indicated that YM022 is a highly potent and selective antagonist for the canine gastrin/CCK-B receptor and suppressed pentagastrin- and peptone meal-induced gastric acid secretion without affecting histamine- or methacholine-induced acid secretion in Heidenhain pouch dogs.

Animals↗
PubMed1997

Successful treatment of severe cytomegalovirus retinitis with foscarnet and intraocular injection of ganciclovir in a myelosuppressed unrelated bone marrow transplant patient.

A female patient with ALL received a bone marrow transplant (BMT) from an unrelated donor with a one locus HLA mismatch. The donor was heterozygous at the HLA-A locus, while the patient was homozygous at this locus. The patient had cytomegalovirus (CMV) antigenemia on day 42 following an intensive preparative regimen that included anti-thymocyte globulin and BU+CY+TBI to prevent graft rejection. Ganciclovir was given initially for the treatment of CMV antigenemia, although the patient soon developed severe myelosuppression. The patient's hematopoietic recovery was poor, and CMV and human herpesvirus-6 (HHV-6) were detectable in the peripheral blood. Severe CMV retinitis was treated with foscarnet and the intraocular injection of ganciclovir. The CMV retinitis improved and the marrow gradually recovered. CMV and HHV-6 were no longer detectable in the peripheral blood. Foscarnet and intraocular injection of ganciclovir appeared to be an effective treatment for CMV retinitis in this myelosuppressed BMT patient.

Adult↗
PubMed1997

YF476 is a new potent and selective gastrin/cholecystokinin-B receptor antagonist in vitro and in vivo.

BACKGROUND: We newly synthesized YF476 ((R)-1-[2,3-dihydro-2-oxo-1-pivaloylmethyl-5-(2'-pyridyl)-1H-1, 4benzodiazepin-3-yl]-3-(3-methylamino-phenyl)urea) as a gastrin/cholecystokinin-B (CCK-B) receptor antagonist. We investigated the pharmacological profile of YF476 in vitro and in vivo. METHODS: We examined the binding properties of YF476 to the rat brain, cloned canine and cloned human gastrin/CCK-B receptors, and the effect of YF476 on secretagogue-induced gastric acid secretion in rats and Heidenhain pouch dogs. RESULTS: YF476 replaced the specific binding of [125I]CCK-8 to the rat brain, cloned canine and cloned human gastrin/CCK-B receptors, with Ki values of 0.068, 0.62 and 0.19 nM, respectively. The affinity of YF476 for rat brain gastrin/CCK-B receptor was 4100-fold higher than that for rat pancreatic CCK-A receptor. In anaesthetized rats, intravenous YF476 inhibited pentagastrin-induced acid secretion with an ED50 value of 0.0086 micromol/kg, but did not affect histamine- and bethanechol-induced acid secretion at a dose of 10 micromol/kg. In Heidenhain pouch dogs, intravenous and oral YF476 inhibited pentagastrin-stimulated gastric acid secretion in a dose-dependent manner with ED50 values of 0.018 and 0.020 micromol/kg, respectively, but did not affect histamine-induced acid secretion. CONCLUSION: These results suggest that YF476 is an extremely potent and highly selective gastrin/CCK-B receptor antagonist, and that the gastrin/CCK-B receptor is not involved in histamine- or bethanechol-induced gastric acid secretion in dogs or rats.

3T3 Cells↗