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Biomedical subjects

A Urabe

Publications and source records attributed to A Urabe.

At least 37 records · Page 2Linked to original sources

Increased serum soluble Fas ligand associated with recurrent B-cell non-Hodgkin's lymphoma after autologous peripheral blood stem cell transplantation.

Fas-ligand (FasL) is a member of the tumor necrosis factor family and transmits apoptotic cell death signal by binding to its receptor, Fas. FasL is expressed on the cell surface of activated T-cell and natural killer (NK) cell. It has been shown that the FasL can be released from the cell surface by metalloproteinase. The serum soluble FasL (sFasL) is increased in some patients with NK cell lymphoma/large granular lymphocytic leukemia. We have recently seen a patient with recurrent B-cell lymphoma accompanied with an increased serum sFasL level after autologous peripheral blood stem cell transplantation. The sFasL was markedly decreased with the tumor regression induced by the chemotherapy. We present here the first case of an elevated serum sFasL level associated with B-cell lineage malignancy and discuss the possible clinical value of sFasL.

Adult↗

Characterization of native human thrombopoietin in the blood of normal individuals and of patients with haematologic disorders.

Thrombopoietin (TPO) isolated from thrombocytopenic plasma of various animal species has previously been shown to comprise only truncated forms of the molecule, presumably generated by proteolysis. Native TPO has now been partially purified from normal human plasma by immunoaffinity chromatography and was confirmed to be biologically active. Gel filtration in the presence of SDS revealed that TPO eluted in two peaks: a major peak corresponding to the elution position of fully glycosylated recombinant human TPO (rhTPO) consisting of 332 amino acid residues, and a minor peak corresponding to a smaller molecular size. Immunoblot analysis also revealed that most plasma-derived TPO migrated at the same position as fully glycosylated rhTPO, corresponding to a molecular size of approximately 80 to 100 kDa. Furthermore, the size distribution of circulating TPO in patients with various haematologic disorders did not differ markedly from that of plasma-derived TPO from healthy individuals. These results indicate that the truncation of circulating TPO is not related to disease pathophysiology, and that the predominant form of TPO in blood is a biologically active approximately 80- to 100-kDa species. The size distribution of TPO extracted from normal platelets was similar to that of TPO in plasma; the proportion of truncated TPO was decreased by prior incubation of platelets with hirudin. indicating that the endogenous truncated TPO, at least in platelet extract, was generated by thrombin-mediated cleavage.

Hematologic Diseases↗

[Clinical effect of idarubicin on malignant lymphoma].

The anti-tumor efficacy and safety of idarubicin (IDR) were investigated among patients in whom the standard therapy for malignant lymphoma had failed or who had suffered a recurrence. IDR was administered at a dose of 12 mg/m2 or 15 mg/m2 by a single i.v. bolus, and this dosage regimen was repeated every 3 weeks. Among total of 21 evaluable patients, there were 3 CRs and 1 PR, for an overall response rate of 19.0% (4/21). All patients who attained CR were cases which had recurred after receiving combination chemotherapy including doxorubicin. Adverse reactions were bone marrow suppression, including leucopenia (90.5%), neutropenia (95.2%), and thrombocytopenia (47.6%); gastrointestinal symptoms such as nausea/vomiting (42.9%) and stomatitis (9.5%); alopecia (23.8%) and fever (19.0%). These results indicate that IDR is effective against refractory malignant lymphoma.

Adult↗

[X-linked sideroblastic anemia].

A 20-year-old man presented with microcytic hypochromic anemia (hemoglobin: 9.3 g/dl, MCV: 82.0 fl, MCHC: 29.5 g/dl) and dimorphism RBCs in circulating blood (RDW: 26.8%). Ringed sideroblasts accounted for 29.5% of bone marrow erythroblasts. Iron overload was also observed. Because the patient had a clear family history of anemia, he was given a diagnosis of X-linked sideroblastic anemia. The activity of delta-aminolevulinic acid synthase (ALAS) in bone marrow erythroblasts was low. However, we did not detect mutation of the gene for ALAS. The patient has responded well to a treatment regimen consisting of oral vitamin B6, Fe-chelation therapy, and phlebotomy.

Adult↗

[Initial treatment of chronic myelogenous leukemia--interferon or bone marrow transplantation].

The two major methods of treatment of chronic myelogenous leukemia (CML) are bone marrow transplantation (BMT) and interferon (IFN) administration. BMT is recommended when patients are young (usually younger than 45 or 50 years old) and have an HLA identical sibling. Otherwise, IFN administration is the treatment of choice. IFN administration results in the eradication or reduction of the Philadelphia chromosome. Such cytogenetic effects have brought about an improvement in the survival of CML patients.

Adult↗

[Successful treatment with splenic irradiation for idiopathic thrombocytopenic purpura associated with primary immunodeficiency syndrome].

A 50-year-old man was admitted to our hospital because of intracranial hemorrhage and thrombocytopenia (platelet count: 3,000/microliter). Low levels of IgG (76 mg/dl) and IgA (30 mg/dl) and a normal pattern of peripheral blood T and B cell subsets yielded a diagnosis of common variable immunodeficiency (CVID). The number of megakaryocytes in bone marrow was within normal limits (64/microliter), and a diagnosis of idiopathic thrombocytopenic purpura was made. Both high-dose intravenous gamma-globulin and prednisolone were ineffective. Because of the coexistence of CVID, splenic irradiation (total 15 Gy) was performed instead of splenectomy. The platelet number began to increase 5 days after the initiation of irradiation, had increased to 8.7 x 10(4)/microliter at the end of irradiation, and was 22.9 x 10(4)/microliter 2 weeks later.

Common Variable Immunodeficiency↗

[Successful pregnancy and delivery during alpha-interferon therapy for essential thrombocythemia].

Essential thrombocythemia (ET) was diagnosed in a 31-year-old woman who had a miscarriage in the first trimester of her first pregnancy. Because of her wish for child, the patient was given alpha interferon (alpha-IFN) instead of hydroxyurea or aspirin to lower her platelet count to about 80 x 10(4)/microliter. She also had a miscarriage in her second pregnancy. Thereafter, the platelet count was kept at 60-70 x 10(4)/microliter by dose escalation of alpha-IFN. In the 35th week of her third pregnancy, the patient delivered a healthy baby with a normal blood count. Several small infarctions were observed in the placenta. Control of platelet count by alpha-IFN administration was effective in preventing recurrent miscarriage associated with ET, and had no adverse effect on patient fertility or fetal development.

Adult↗

Chronic neutrophilic leukemia associated with chronic lymphocytic leukemia.

We report on an 83-year-old male with chronic neutrophilic leukemia (CNL) associated initially with IgM monoclonal gammopathy and later with B cell chronic lymphocytic leukemia (CLL), in which the clone differed from that of the preceding monoclonal gammopathy. At initial presentation, the patient had hepatosplenomegaly, leukocytosis (29100 x 10(6)/l) with an increase of mature neutrophils (83%), 20q- chromosomal abnormality, an increased leukocyte alkaline phosphatase score, elevated serum levels of vitamin B12 and uric acid, a low serum level of granulocyte colony-stimulating factor, and high serum IgM (1015 mg/dl: lambda type M protein). Thereafter, lymphocytosis developed gradually. Three years after the initial presentation, the patient had no serum M protein, but showed evidence of leukocytosis (36600 x 10(6)/l) with 20q- chromosomal abnormality and an increase of mature neutrophils (51%) and small lymphocytes (43.5%), CD5+/19+/20+/HLA-DR+ and surface membrane IgM+/D+/kappa+. Gene rearrangements of the immunoglobulin heavy and kappa light chains were also present. To our knowledge, this is the first reported case of CNL associated with CLL.

Aged↗

Tyrosine phosphorylation of proteins in primary human myeloid leukemia cells stimulated by cytokines: analysis of the frequency of phosphorylation, and partial identification and semi-quantification of signaling molecules.

We investigated tyrosine phosphorylation of proteins in primary human leukemia cells stimulated by granulocyte colony-stimulating factor (G-CSF), granulocyte-macrophage CSF (GM-CSF), interleukin-3 (IL-3), tumor necrosis factor (TNF), thrombopoietin (TPO) and phorbol myristate acetate (PMA) in 61 patients with acute myeloid leukemia (AML), nine patients with chronic myeloid leukemia (CML) in blastic crisis and four patients in chronic phase, and compared these data of leukemia with those of normal human immature hematopoietic cells. These cytokines and PMA induced tyrosine phosphorylation of proteins in a manner characteristic for each cytokine or PMA in AML cells. G-CSF, GM-CSF and IL-3 frequently phosphorylated p92, p80, p70, p44 and p42. p95 was frequently phosphorylated by G-CSF, and was phosphorylated in one third of the cases by TPO. On the other hand, TNF selectively induced tyrosine phosphorylation of p42, and PMA selectively induced that of p44 and p42. In marked contrast to AML cells, CML cells responded poorly to cytokines with protein tyrosine phosphorylation, and normal human bone marrow mononuclear cells and CD34-positive cells also showed poor response to cytokines. The results of the immunoprecipitation studies showed tyrosine phosphorylation of signal transducers and activators of transcription (Stat) 5 induced by G-CSF, GM-CSF, IL-3 and/or TPO in six cases, that of extracellular signal-regulated kinase (ERK) by GM-CSF in two cases and that of p38 by TNF in three cases. Intracellular amount of Stat5 was markedly increased in AML cells compared with that in CML cells and normal human bone marrow cells. whereas intracellular amount of ERK and p38 was uniformly abundant in both leukemic and normal cells. These results show cytokine-specific and amplified tyrosine phosphorylation of proteins in AML cells and suggest that amplified response might, at least in part, result from the increased amount of signaling molecules such as Stat5.

Acute Disease↗

R411C mutation of the ALAS2 gene encodes a pyridoxine-responsive enzyme with low activity.

A R411C missense mutation of the erythroid-specific delta-aminolaevulinate synthase (ALAS2) gene was identified in a pedigree with X-linked pyridoxine-responsive sideroblastic anaemia (XLSA). The normal and the mutant cDNAs were expressed in E. coli, and the enzyme protein was purified. ALAS activity of the mutant enzyme was 12% and 25%, when incubated in the absence and the presence of pyridoxal 5'-phosphate, respectively, compared with that of the wild-type enzyme. These findings suggest that the R411C mutation accounts for low ALAS activity and a partial pyridoxine-responsiveness of the disease in the patient.

5-Aminolevulinate Synthetase↗

Regulation of hepatic thrombopoietin production by portal hemodynamics in liver cirrhosis.

OBJECTIVE: This study was designed to clarify how thrombopoietin (TPO) functions in and, to some extent, causes thrombocytopenia complicating liver cirrhosis and portal hypertension. METHODS: Our study population consisted of 19 cirrhotic and six noncirrhotic patients who underwent percutaneous transhepatic portography (PTP) and hepatic venography. RESULTS: The platelet counts of the cirrhotic patients were significantly lower than those of the noncirrhotic patients (8.7 +/- 4.1 vs 17.4 +/- 7 x 10(4)/microl; p < 0.01). The flow direction in the splenic vein was confirmed by PTP. Ten hepatofugal and nine hepatopetal flow directions in the splenic vein were noted among the cirrhotics. The hepatofugal group showed lower portal venous pressure (20 +/- 10 vs 32 +/- 4 cm H2O; p < 0.01) than the hepatopetal group and had a higher incidence of hepatic encephalopathy (six of 10 vs zero of nine; p < 0.01). The hepatic vein-portal difference in TPO did not differ substantially between the cirrhotics and noncirrhotics (0.12 +/- 0.04 vs 0.24 +/- 0.07 fmol/ml). Comparisons of this value among the three groups showed the TPO difference to be lowest in the hepatofugal group (hepatofugal: 0.04 +/- 0.03, hepatopetal: 0.21 +/- 0.07, noncirrhotic: 0.24 +/- 0.07; p < 0.05). CONCLUSIONS: Our findings suggest that TPO production in the cirrhotic liver is regulated by the portal blood supply to the liver. Thus, portal hemodynamics may play a critical role in the development of thrombocytopenia.

Aged↗

[Polyclonal plasmacytosis in peripheral blood and leukocytoclastic vasculitis in Castleman's disease].

A 62 year-old man had fever, splenomegaly, systemic lymphadenopathy and palpable petechiae. Laboratory studies showed leukocytosis (10,200/microliters) with plasma cells (23%) and polyclonal gammopathy. Southern blot analysis of peripheral blood mononuclear cells showed no rearrangement of immunoglobulin genes, indicating polyclonal plasmacytosis in peripheral blood. A diagnosis of Castleman's disease was made by the cervical lymph node biopsy, which showed onion-skin structures in the germinal centers and plasmacytosis in the interfollicular region. A skin biopsy of the purpura lesion disclosed leukocytoclastic vasculitis. This is an unusual case of Castleman's disease presenting plasmacytosis in peripheral blood and leukocytoclastic vasculitis.

Castleman Disease↗

[Mediastinal germ-cell tumor associated with AML (M7)--the syndrome of mediastinal germ-cell tumors associated with hematologic neoplasia?].

In October 1992, a 36-year-old man was diagnosed as having mediastinum mixed germ cell tumor (stage II), and was treated with surgical operation and combination chemotherapy including VP16 (total VP16 dose; 1,500 mg/m2). After that, remission had been sustained, but leukocytosis (15,700/microliter) with 37% of peroxidase-negative blasts and thrombocytopenia developed in September, 1995. Bone marrow showed remarkable reticulin fibrosis and increase of atypical immature cells that were immunophenotypically factor VIII+/CD42+/CD61+. Thus, we diagnosed acute megakaryoblastic leukemia (M7). Based on no abnormality of chromosome 11q23 and no rearrangements of MLL gene, we diagnosed the syndrome of mediastinal germ-cell tumors associated with hematologic neoplasia. Furthermore, the neuron-specific enolase level was elevated (95.9 ng/ml). Soon after complete remission was reached by combination chemotherapy, the leukemia was relapsed, and the he died 3 months after the onset of leukemia. To our knowledge, this is the third case report of this syndrome in Japan and the first one of leukemia with high level of serum neuron-specific enolase.

Adult↗