N Kobayashi

Effect of thrombin and endotoxin on the in vivo metabolism of antithrombin III (AT III) in dogs.

Effect of thrombin and endotoxin on the metabolism of I-125-labelled canine AT III was studied in mongrel dogs. Under control condition, mean total amount of intravascular AT III with standard deviation was 23.4 +/- 2.4 mg/kg, plasma half life of i.v. injected I-125-AT III was 1.7 +/- 0.2 days, and the fractional catabolic flux (j3x) was 16.3 +/- 1.6 mg/kg/day. The total amount of intra- and extra-vascular AT III was 36.0 +/- 0.34 mg/kg. Neither a 3 hour infusion of a small dose (30 units/kg/hr) of thrombin nor i.v. injection of a large amount of thrombin (5,000-15,000 units/day) with heparin significantly affected AT III metabolism except for a transient decrease in AT III concentration in the latter case, although decrease in plasma fibrinogen concentration and platelet count was observed in both cases. Two injections with 200 micrograms/kg of endotoxin resulted in an evident acceleration of AT III metabolism with significant decrease in the plasma AT III, fibrinogen concentrations and platelet count. More marked changes in AT III metabolism were induced by a single infusion with 1 mg/kg of endotoxin. Changes in hemostatic system coincided with those observed in DIC.

Long non-coding RNA MALAT1 is an inducible stress response gene associated with extramedullary spread and poor prognosis of multiple myeloma

Extramedullary myeloma (EMM) occurs when myeloma develops outside the bone marrow; it often develops after chemotherapy and is associated with the acquisition of chemo‐resistance and a fatal course. The mechanisms underlying extramedullary spread have not yet been fully elucidated. MALAT1 is a highly abundantly and ubiquitously expressed long non‐coding RNA that plays important roles in cancer metastasis. The aims of this study were to clarify the association of MALAT1 with EMM and to elucidate the underlying mechanism of EMM formation under chemotherapeutic pressure. MALAT1 expression was significantly higher in multiple myeloma (MM) than in monoclonal gammopathy of undetermined significance. Furthermore, MALAT1 expression was markedly higher in EMM compared with that in corresponding intramedullary myeloma cells. A higher MALAT1 level was associated with shorter overall and progression‐free survival. MALAT1 expression level was positively correlated with expression of HSP90AA1, HSP90AB1 and HSP90B1 but not with TP53 expression. MALAT1 was significantly upregulated by bortezomib and doxorubicin. Considering the known functions of MALAT1, our results suggest that it acts as a stress response gene that is upregulated by chemotherapy, thereby linking chemotherapy to EMM formation. Elucidating the biological implication of long non‐coding RNA contributes to deeper understanding concerning the pathogenesis and investigation of novel therapeutic targets for MM.

Complete remission achieved by steroid pulse therapy following rituximab treatment in a case with autoimmune haemorrhaphilia due to anti-factor XIII antibodies

Complete remission achieved by steroid pulse therapy following rituximab treatment in a case with autoimmune haemorrhaphilia due to anti-factor XIII antibodies -

Radioimmunoassay of human tissue factor

The apoprotein (AP) of tissue factor (TF) has been purified 72,000-fold to homogeneity from human placenta using acetone delipidation, sodium deoxycholate (DOC) extraction, Sephacryl S-300 column chromatography, preparative polyacrylamide-gel electrophoresis (PAGE) in DOC and tryptic digestion. The purified AP had an apparent molecular weight of 54,000 by sodium dodecyl sulfate/PAGE. A radioimmunoassay (RIA) for quantitation of the TF-AP using an antibody against this purified AP of TF was devised which was sensitive enough to measure as small a quantity as 100 pg/ml of TF-AP accurately with high reproducibility. In addition to TF clotting activity (TFA), the immunoreactive TF-AP (IR-TFR) in the homogenates of leukemic leukocytes from patients with acute non-lymphoid leukemia (ANLL) was determined using this RIA. In 30 patients with ANLL, the mean IR-TFR with standard deviation (SD) of 21 cases with DIC was 157.9 +/- 188.1 ng/10(8) cells, which was significantly higher than that (37.1 +/- 29.9 ng/10(8) cells) of 9 cases with no DIC during remission induction chemotherapy (p less than 0.01).

Collision of metastatic malignant melanoma and acute myelogenous leukemia in the bone marrow

Coincidentally, clusters composed of atypical large cells were observed in the bone marrow (Fig. 1a). These large atypical cells had basophilic cytoplasm and vacuoles (Fig. 1b), and were morphologically different from the leukemic blasts, which were medium-sized with high nuclear:cytoplasmic ratio and small azurophilic granules (Fig. 1c). Immunohistochemistry further revealed that the atypical cells were positive for S-100 and Melan A (Fig. 2a). Hematopoietic cells around the clusters were positive for MPO (Fig. 2b). Accordingly, we diagnosed this case as collision of malignant melanoma and AML. The patient chose palliative care and died 3 months later. Although malignant melanoma often presents with bone marrow metastasis, collision of a solid tumor and acute leukemia is very rare. In our case, it is not clear which malignancy occurred first in the bone marrow; however, the two types of tumors appear to have proliferated concurrently. This finding suggests that different tumors can proliferate in a limited space, such as the bone marrow, and are not necessarily mutually A 78-year-old man diagnosed with malignant melanoma (nodular melanoma type in the Clark classification) on the left upper limb was referred to our department because of pancytopenia. Following surgery, the pathological diagnosis was T4aN3M0 stage IIIc. He received neither chemotherapy nor radiation. His hemoglobin concentration was 74 g/L; white blood cell count, 1.1 × 109/L; platelet count, 55 × 109/L; and blasts appeared in the peripheral blood. Bone marrow examination revealed increased blasts of 58.8%; thus, he was diagnosed with acute myelogenous leukemia (AML) with maturation, following the World Health Organization classification. Chromosomal analysis revealed a complex karyotype containing 51, XY, +1, der(1;21)(q10;q10), +4, der(4;6) (q10;q10), +6, +7, +8, add(13)(p11.2), +20, +22, whereas known chimeric genes were not detected by multiplex PCR. The protein expressions of CD13, CD33, myeloperoxidase (MPO), and CD117 were positive, while the CD34 and HLA-DR expressions were negative.

Successful Treatment of Epstein-Barr Virus-Associated Lymphoproliferative Disorder with Rituximab in a Patient Undergoing Immunosuppressive Therapy for Aplastic Anemia.

Epstein-Barr virus-associated lymphoproliferative disorder (EBV-LPD) is a currently emerging serious complication in immunosuppressed patients, especially in allogeneic transplant recipients. Several fatal cases of EBV-LPD have been reported in aplastic anemia (AA) patients receiving immunosuppressive therapy (IST) with antithymocyte globulin (ATG) plus cyclosporine A (CsA), but no appropriate prophylactic or therapeutic strategy has been established. Herein, we describe a 29-year-old man whose EBV-LPD was successfully treated with rituximab. He received IST with ATG plus CsA for hepatitis-associated AA. EBV-DNA in plasma, which was not detectable before IST, gradually increased after IST initiation. A high fever and systemic lymphadenopathy developed 31 days after IST initiation. An EBV-DNA titer of 5.7 × 105 copies/μl was detected, and a diagnosis of EBV-LPD was made. Although discontinuation of IST was not effective, a single dose of rituximab on day 33 resolved the clinical symptoms and completely eliminated EBV-DNA. Even after restarting CsA administration, no elevation of EBV-DNA was observed, and his complete blood cell count had fully recovered 1 year after IST. This case suggests that this treatment strategy for EBV-LPD with EBV-DNA monitoring and rituximab administration, which has been recommended in allogeneic transplant recipients, may also be useful in the context of AA patients receiving IST.