D-dimer level elevation can aid in detection of asymptomatic COVID-19 presenting with acute cerebral infarction.

Coronavirus disease 2019 (COVID-19) mainly manifests as a respiratory syndrome, besides causing other complications. Severe COVID-19 may also present with coagulopathy, leading to venous thrombosis and cerebral infarction. Generally, acute stroke is a secondary complication in patients displaying respiratory syndromes. Here, we present a case of acute stroke in an 84-year-old female patient who did not manifest any respiratory symptoms. The patient had no cough or fever before the stroke onset; nevertheless, COVID-19 PCR test was positive. The patient also had markedly elevated serum D-dimer levels. Our findings suggest that coagulopathy can occur even in a patient with asymptomatic COVID-19 infection, and to our knowledge, this is the first report of such a case. We concluded that elevated D-dimer levels can serve as an additional COVID-19 screening tool in stroke patients.

Intracellular galectin-9 activates inflammatory cytokines in monocytes.

Whether galectin-9 plays a role in inflammatory responses remains elusive. The present study was designed to determine the role of intracellular galectin-9 in activation of inflammatory cytokine genes in human monocytes. Galectin-9 expression vector pBKCMV3-G9 was transiently co-transfected into THP-1 monocytic cells along with luciferase reporters carrying gene promoters of IL-1alpha (IL1A), IL-1beta (IL1B) and IFNgamma. Transient transfection studies showed that galectin-9 over-expression activated all three gene promoters, suggesting that intracellular galectin-9 induces inflammatory cytokine genes in monocytes. Galectin-9 over-expression also activated NF-IL6 (C/EBP beta) and AP-1, but not NF-kappaB. In contrast, extracellular galectin-9 is not involved in regulation of inflammatory cytokines. Immunoprecipitation/Western blotting, using anti-galectin-9 Ab and anti-NF-IL6 Ab, showed physical association of intracellular galectin-9 with NF-IL6. RT-PCR confirmed that galectin-9 over-expression increased IL-1alpha and IL-1beta mRNA levels in THP-1 cells. The interaction of galectin-9 with NF-IL6 was enhanced following LPS treatment in THP-1 cells. Intracellular galectin-9 synergized with LPS to activate NF-IL6. Nuclear translocation of galectin-9 was also observed in THP-1 cells treated with LPS. Our results indicate that galectin-9 is a LPS-responsive factor, and further demonstrate that intracellular galectin-9 transactivates inflammatory cytokine genes in monocytes through direct physical interaction with NF-IL6.

Intracellular HMGB1 transactivates the human IL1B gene promoter through association with an Ets transcription factor PU.1.

High mobility group box 1 protein (HMGB1), originally described as a non-histone, DNA binding protein, was recently identified as a late mediator of inflammation via its extracellular release from activated macrophages/monocytes. In the present study, we report that intracellular HMGB1 synergizes with a macrophage/monocyte-specific E26 transformation-specific sequence (Ets) transcription factor PU.1 to transactivate the promoter of the IL1B gene coding a 31-kDa proIL-1beta protein. The -131 to +12 IL1B promoter, which possesses a PU.1 binding motif essential for its transactivation, was induced when HMGB1 expression vector was transfected into murine RAW264.7 macrophage cells. Our glutathione S-transferase-pulldown and coimmunoprecipitation assays demonstrated direct physical interaction of HMGB1 with PU.1. Deletion of the PU.1 winged helix-turn-helix DNA-binding domain inhibited the association of the two proteins. In electrophoretic mobility shift assay using recombinant PU.1 protein, a ternary complex of PU.1, HMGB1 and PU.1-binding element within the IL1B promoter was generated. The importance of PU.1 was further supported by our observation that induction of the IL1B promoter was obtained only after PU.1 expression in PU.1-deficient murine EL4 thymoma cells. Thus, our data raise the possibility of a novel mechanism which sustains and amplifies inflammatory reactions through physical interaction of PU.1 with intracellular HMGB1 in macrophages/monocytes.

Constitutive association of MyD88 to IRAK in HTLV-I-transformed T cells.

OBJECTIVE: Constitutive activation of nuclear factor (NF)-kappaB is a common feature of human T-cell leukemia virus type I (HTLV-I)-transformed T cells. Inhibition of NF-kappaB activity reduces cell growth and induces apoptosis of HTLV-I-transformed T cells, suggesting a central role of NF-kappaB in their proliferation and survival. In this study, we investigated whether MyD88, an adaptor protein of Toll-like receptor (TLR) signaling, contributes to constitutive NF-kappaB activation in HTLV-I-transformed T cells. MATERIALS AND METHODS: Activation status of MyD88 and interleukin (IL)-1R-associated kinase 1 (IRAK1) in HTLV-I-transformed human T cells, MT2, MT4, and HUT102 was examined by using Western blot and immunoprecipitation. TLR expression was evaluated with reverse transcription polymerase chain reaction. An expression vector encoding a dominant negative MyD88 with a deletion of its death domain (MyD88dn) was transfected into MT2 cells to evaluate roles of MyD88 in spontaneous activation of cytokine gene promoters and transcription factors, proliferation, and apoptosis in HTLV-I-transformed T cells. RESULTS: Constitutive association of MyD88 with IRAK1 was observed in all three of HTLV-I-transformed T cells, but not in HTLV-I-negative T cells, such as Jurkat, HUT78, and MOLT4. MT2 cells showed expression of TLR-1, -6, and -10 mRNAs. Constitutive activation of NF-kappaB and NF-IL-6 and cytokine gene promoters, such as IL-1alpha, interferon-gamma, and tumor necrosis factor-alpha in MT2 cells was inhibited by MyD88dn expression. MyD88dn reduced proliferation and induced apoptosis of MT2 cells. HTLV-I Tax enhanced TLR expression and synergistically activated NF-kappaB with wild-type MyD88. CONCLUSION: Our results show a novel pathway in NF-kappaB activation in HTLV-I-transformed T cells and further demonstrate a critical role of MyD88 in their dysregulated gene activation, survival, and proliferation.

[Angioimmunoblastic T-cell lymphoma accompanied by pure red cell aplasia].

A 71-year-old woman was admitted in December 2002 because of lymphadenopathy, hepatosplenomegaly and pleural effusion. She had severe anemia with hemoglobin 5.9 g/dl and a reticulocyte count of 1% per hundred. Direct/indirect Coombs tests and anti-double stranded DNA antibody were positive, her serum CH50 level was reduced and an increase in serum LDH isoenzyme 3 was observed. Bone marrow aspiration showed an almost total absence of erythroblasts and no pathological cell proliferation. The diagnosis of angioimmunoblastic T-cell lymphoma (AILT) was made based on the lymph node histological findings. Proliferation of arborizing small vessels with hyperplastic endothelium and infiltration of atypical T-lymphocytes were observed. After combination chemotherapy (THP-COP), remission was achieved in both the pure red cell aplasia (PRCA) and AILT. Remission was also accompanied by normalization of the Coombs tests, suggesting that autoimmune mechanisms in AILT may contribute to the development of PRCA.

[Generalized erythema triggered by a rapid decrease of basophils in chronic myeloid leukemia treated with imatinib].

A 57-year-old woman with chronic myeloid leukemia showing severe basophilia (WBC 17.1 X 10(9)/L, basophils 23%) was treated with 400mg imatinib in June 2003. A high basophil count (WBC 10.6 X 10(9)/L, basophils 31%) was still observed after 1 week of therapy. After 9 days of therapy, she developed generalized pruritic skin erythema, chills and high fever. After terminating imatinib treatment, prednisolone therapy was initiated. The rash quickly disappeared. Four days after withdrawal of imatinib, leukocyte count was 13.0 X 10(9)/L with 3% of basophils, suggesting the possibility that rapid decrease in basophils following imatinib therapy may induce severe cutaneous reactions.

[Remission induction of refractory diffuse large B-cell lymphoma with allogeneic peripheral blood stem cell transplantation followed by interferon-alpha and donor lymphocyte infusion].

Graft-versus-lymphoma (GVL) effect has been described in patients with malignant lymphoma after allogeneic stem cell transplantation (alloSCT). The effect of interferon-alpha (IFN-alpha) on the GVL effect still remains unclear. Here we report on a 29-year-old woman with refractory diffuse large B-cell lymphoma (DLBL). Her clinical findings included multiple masses in the liver, stomach, bilateral kidneys, thyroid, vertebral bones and a bulky mediastinal mass. Since the patient did not respond to various combination chemotherapies and further developed superior vena cava syndrome, allogeneic peripheral blood stem cell transplantation (PBSCT) from a HLA-identical brother was carried out after a myeloablative TBI/CY-based conditioning regimen. DLIs have been also performed every 4 weeks since day +14. As a result, the lymphoma masses showed a partial response. In order to enhance the GVL effect, IFN-alpha was further given at a maximum of 3 MU four times per week. Although the patient only experienced graft-versus-host disease of the skin (grade II) even after both DLIs and IFN, complete clinical remission was observed. 200 days after transplantation, the patient is still disease-free and in good condition. This report suggests the curative potential of IFN-alpha combined with DLI after allogeneic SCT in refractory DLBL.

Growth suppression of human mast cells expressing constitutively active c-kit receptors by JNK inhibitor SP600125.

Activation of c-jun N-terminal kinase (JNK) through c-kit-mediated phosphatidylinositol 3 (PI3) and Src kinase pathways plays an important role in cell proliferation and survival in mast cells. Gain-of-function mutations in c-kit are found in several human neoplasms. Constitutive activation of c-kit has been observed in human mastocytosis and gastrointestinal stromal tumor. In the present study, we demonstrate that an anthrapyrazole SP600125, a reversible ATP-competitive inhibitor of JNK inhibits proliferation of human HMC-1 showed constitutive activation of JNK/c-Jun, and the inhibitory effect of SP600125 on cell proliferation was associated with cell cycle arrest at the G1 phase and apoptosis accompanied by the cleavage of caspase-3 and PARP. Caspase-3 inhibitor Z-DEVD-FMK almost completely inhibited SP600125-induced apoptosis of HMC-1 cells. In contrast, caspase-9 inhibitor Z-LEHD-FMK failed to block SP600125-induced apoptosis. Following Sp600125 treatment, down-regulation of cyclin D3 protein expression, but not p53 was also observed. Thus, JNK/c-Jun is essential for proliferation and survival of HMC-1 cells. The results obtained from the present study suggest the possibility that JNK/c-Jun may be a therapeutic target in diseases associated with mutations in the catalytic domain of c-kit.

Constitutive tyrosine and serine phosphorylation of STAT4 in T-cells transformed with HTLV-I.

STAT4 is a critical mediator of IL-12-stimulated gene regulation in T-helper type 1 (Th1) cell. IL-12 activates the Janus family tyrosine kinases JAK2 and Tyk2, which in turn phosphorylate STAT4 on tyrosine 693. The p38 mitogen-activated protein kinase (MAPK) signaling pathway is also activated in response to IL-12, followed by phosphorylation of STAT4 on serine 721, which is required for STAT4 full transcriptional activity. In the present study, we demonstrated constitutive activation of STAT4 in HTLV-I-transformed T-cell lines MT-2, MT-4 and HUT102 by immunoprecipitation, Western blotting and electrophoretic mobility shift assay (EMSA). In HTLV-I-transformed T-cell lines, STAT4 was constitutively phosphorylated not only on tyrosine 693 but also on serine 721, and formed a heterodimer with STAT3. Constitutive phosphorylation of its upstream activators, JAK2, Tyk2 and p38 MAPK was also observed in the cells. EMSA and transient transfection studies further showed that the high-affinity sis-inducible element (hSIE) preferentially binds the STAT3/STAT4 heterodimer and is constitutively transactivated in MT-2 cells in the absence of exogenous cytokine stimulation. When STAT4 expression vector was cotransfected along with STAT3 expression vector into MT-2 cells, STAT4 significantly synergized with STAT3 to transactivate hSIE, showing the functional importance of heterodimer formation between STAT4 and STAT3.

Clinical profiles and outcomes of end-stage renal failure patients with late initiation of renal replacement therapy based on uremic symptoms under intensive renoprotective therapies.

AIM: This study describes the clinical profiles and outcomes of renal failure patients with late initiation of renal replacement therapies (RRT) based on uremic symptoms under intensive treatment prior to the start of RRT (IT). METHODS: Thirteen patients (male 10, female 3) with end-stage renal disease who preferred to wait for the initiation of RRT until uremic symptoms appeared regardless of serum creatinine (s-Cr) and 24-hour creatinine clearance (24-hour Ccr) were chosen. All patients received IT including a low-protein diet, antihypertensive drugs including enalapril, erythropoietin and others to prevent and manage uremic states until the initiation of RRT. Clinical findings at the initiation of RRT and the outcomes after the start of RRT were examined. RESULTS: RRT was initiated 23.6 +/- 16.9 months after IT without any complication in all patients when mild uremic symptoms appeared. Uremic symptoms, blood pressure, serum albumin, potassium, calcium and urinary Cr excretion were well controlled except inorganic phosphate, hemoglobin and cardiac size. 24-hour Ccr and s-Cr were 3.4 +/- 0.7 ml/min and 17.4 +/- 3.8 mg/dl at initiation of RRT. The outcomes of all the patients were all well during chronic RRT. CONCLUSION: Intensive treatment prior to the start of RRT can diminish uremic symptoms and complications so that RRT might be initiated safely and with fewer problems, even in the face of lower 24-hour Ccr and markedly higher s-Cr.

Imatinib mesylate-sensitive blast crisis immediately after discontinuation of imatinib mesylate therapy in chronic myelogenous leukemia: report of two cases.

Although imatinib mesylate has shown encouraging activity in chronic myelogenous leukemia (CML), disease progression during therapy has been observed, manifested by clonal expansion of imatinib mesylate-resistant leukemia cells. On the other hand, myelosuppression related to treatment of imatinib mesylate is often managed with temporary interruption of treatment or dose reduction. We here report two CML patients who had imatinib mesylate-sensitive blast crisis (BC) immediately after discontinuation of imatinib mesylate therapy. The patients discontinued therapy because of neutropenia. Although there was no evidence of blastic phase during therapy, BC occurred 2 weeks after the withdrawal of treatment in both cases. Interestingly, additional chromosomal abnormalities were detected following the withdrawal of imatinib mesylate and disappeared by re-introduction of this agent. The same doses of imatinib mesylate was still effective and remission was sustained with imatinib mesylate alone again. Our report suggests the possibility that withdrawal of imatinib mesylate may lead to proliferation of blast clones even in patients showing good responses to imatinib mesylate without signs of disease progression.