Superconductivity in 5d transition metal Laves phase SrIr2.

We report here the superconducting properties of a Laves phase superconductor SrIr2, which has a cubic MgCu2 structure. SrIr2 is a type-II superconductor, with a T c of 5.9 K. The estimated superconducting parameters of lower critical field µ 0 H c1 and upper critical field µ 0 H c2, coherence length ξ(0), penetration depth λ(0) and Ginzburg-Landau (GL) parameter κ(0) are approximately µ 0 H c1 = 101 Oe, µ 0 H c2(0) = 5.9 T, ξ(0) = 7.47 nm, λ(0) = 237 nm, and κ(0) = 31.7, respectively. The specific-heat data indicate that SrIr2 is a strong-coupling superconductor because the value of ΔC/γT c is approximately 1.71, which is larger than the value of 1.43 that is expected from the BCS theory. The physical properties obtained in this study are explained well by theoretical calculations including spin-orbit coupling (SOC). This result indicates that the physical properties of SrIr2 are strongly affected by the presence of SOC.

Decreased expression of CXXC4 promotes a malignant phenotype in renal cell carcinoma by activating Wnt signaling.

The Wnt signaling pathway is involved in normal embryonic development and controls the homeostatic self-renewal of stem cells in adult tissues. Constitutive activation of Wnt signaling contributes to cancer development and progression. We identified a CXXC4 homozygous deletion at 4q24 in an aggressive renal cell carcinoma (RCC) using single-nucleotide polymorphism (SNP) arrays. CXXC4 encodes Idax, which negatively regulates Wnt signaling by binding to the PDZ domain of Dishevelled. CXXC4 mRNA levels in tumor samples were significantly lower in patients with metastases compared with those without (P=0.0016). Patients whose tumors had lower CXXC4 expression than normal kidney showed a poorer cause-specific survival outcome than those with higher expression (P=0.0095). Decreased expression of CXXC4 also correlated with cytoplasmic staining of beta-catenin. Knockdown of CXXC4 induced the nuclear translocation of beta-catenin and altered expression of a set of genes involved in cell proliferation, invasion and survival. Furthermore, reduced expression of CXXC4 by small interfering RNAs promoted cell proliferation and inhibited apoptosis after 5-FU and doxorubicin treatment in RCC cells. These data suggest that CXXC4 plays a critical role in tumor progression of RCC through Wnt signaling. Wnt signaling could thus be a potential molecular target in RCC indicating decreased CXXC4 expression.

Inhibition of Bach1 ameliorates indomethacin-induced intestinal injury in mice.

BTB and CNC homolog 1 (Bach1) is a transcriptional repressor of heme oxygenase-1 (HO-1). It plays an important role in the feedback regulation of HO-1 expression, which protects cells from various insults including oxidative stress and inflammatory cytokines. However, the role of Bach1 in intestinal inflammation remains unclear. In this study, the role of Bach1 in intestinal mucosal injury was elucidated using 8-week-old female C57BL/6 (wild-type) and homozygous Bach1-deficient C57BL/6 mice. Intestinal mucosal injuries induced by a single subcutaneous administration of indomethacin were evaluated macroscopically, histologically, and biochemically. Mucosal protein content and chemokine mRNA levels were determined by real-time PCR. Our results showed that the indomethacin-induced intestinal injury was remarkably improved in Bach1-deficient mice. Histological examination showed that the area of injured lesion was decreased in Bach1-deficient mice compared to wild-type mice. Administration of indomethacin induced expression of inflammatory chemokines such as KC, MIP1alpha and MCP1, which was suppressed in Bach1-deficient mice. Myeloperoxidase activity in the intestinal mucosa was also significantly decreased in Bach1-deficient mice. Additionally, Bach1 deficiency enhanced immunopositivity of HO-1 in the intestinal mucosa after indomethacin administration. Disruption of the Bach1 gene thus caused inhibition of mucosal injury, indicating that inhibition of Bach1 may be a novel therapeutic strategy for treating indomethacin-induced intestinal injury.

DHMEQ, a new NF-kappaB inhibitor, induces apoptosis and enhances fludarabine effects on chronic lymphocytic leukemia cells.

Chronic lymphocytic leukemia (CLL) is a low-grade lymphoid malignancy incurable with conventional modalities of chemotherapy. Strong and constitutive nuclear factor kappa B (NF-kappaB) activation is a characteristic of CLL cells. We examined the effects of a new NF-kappaB inhibitor, dehydroxymethylepoxyquinomicin (DHMEQ), on CLL cells. Dehydroxymethylepoxyquinomicin completely abrogated constitutive NF-kappaB activity and induced apoptosis of CLL cells. Apoptosis induced by DHMEQ was accompanied by downregulation of NF-kappaB-dependent antiapoptotic genes: c-IAP, Bfl-1, Bcl-X(L) and c-FLIP. Dehydroxymethylepoxyquinomicin also inhibited NF-kappaB induced by CD40 and enhanced fludarabine-mediated apoptosis of CLL cells. Results of this study suggest that inhibition of constitutive and inducible NF-kappaB by DHMEQ in combination with fludarabine is a promising strategy for the treatment of CLL.

Primary gastric T-cell lymphoma not associated with human T-lymphotropic virus type I: a case report and review of the literature.

Primary gastric T-cell lymphoma (PGTL) not associated with human T-lymphotropic virus type I (HTLV-I) is extremely rare and such a case is reported herein. The patient was a 58-year-old Japanese male presenting with submucosal tumor of the stomach identified on endoscopic examination. The lesion was diagnosed as non-Hodgkin's lymphoma by endoscopic biopsy and classified as peripheral T-cell lymphoma, unspecified, due to clonal rearrangement of the T-cell receptor beta (TCR) gene and expression of TCR beta protein in the absence of B-cell genotypes and phenotypes. Unlike previously reported cases of HTLV-I-unassociated PGTL, lymphoma in the current case was characterized histologically as "low grade" and phenotypically as CD4+, TIA-1+, granzyme B+, and CD103-. The lymphoma responded well to chemotherapy and radiation, and the patient was well with no detectable disease 10 months after initiation of therapy. A review of patients with PGTL in the literature revealed a few long-term survivors, and the investigation of therapeutic strategies for PGTL is, therefore, necessary.

White matter lesions and alteration of vascular cell composition in the brain of spontaneously hypertensive rats.

There have been few studies on the white matter lesions of spontaneously hypertensive rats (SHR). From the point of view of hypertension and arteriosclerosis, white matter lesions were examined in SHR and stroke-prone SHR (SHRSP), and were then compared with Wistar-Kyoto (WKY) rats. The vasculopathy was analyzed by morphometric immunohistochemistry for collagen and smooth muscle actin. Both SHR and SHRSP had hypertension at > or = 12 weeks of age, and the latter developed severe white matter lesions at 20 weeks. Immuno- histochemistry revealed proliferation of microglia in the white matter and an increase in smooth muscle actin in the vessels of SHRSP compared with the WKY rats and SHR, but there were no changes in the collagen. These results indicate a role of hypertension in the pathogenesis of white matter lesions. However, genetic difference may also be responsible since SHR and SHRSP showed similar hypertension.

Molecular cloning and sequencing of myosin light chains in human megakaryoblastic leukemia cells.

Myosin light chain genes of hematopoietic cells have yet to be characterized. We cloned the full-length cDNAs of 20 kDa regulatory myosin light chain (MLC-2) and 17 kDa essential myosin light chain (MLC-3) from Meg-01, a human megakaryoblastic leukemia cell line. Both MLC-2 and MLC-3 gene are transcribed ubiquitously in various hematopoietic cells. The MLC-2 open reading frame of 516 nucleotides encoding a protein of 172 residues was detected in cloned cDNA of 967 nucleotides. The Ca2+-binding domain and five phosphorylation sites were highly conserved. The deduced amino acid sequence has a 99.4% and 100% homology with that of human fetus brain and human lymphocyte, respectively. The MLC-3 open reading frame of 453 nucleotides encoding a protein of 151 residues was detected in cloned cDNA of 742 nucleotide. The MLC-3 protein is 99.3% identical to that of human fibroblasts. These results suggest that hematopoietic myosin light chain proteins are similar to those of other nonmuscle cells and smooth muscle, thus differing from skeletal and cardiac muscles.

[Role of ultrasonography in diagnosis of neutropenic enteritis: a study of 4 cases].

Neutropenic enteritis is a septic or inflammatory disease of the colon. It is usually encountered in patients with hematological malignancy who have undergone chemotherapy, and it presents as fever, diarrhea, and abdominal pain, although the symptoms are not always specific. The diagnostic features of neutropenic enteritis revealed by barium enema, CT and ultrasonography have been reported previously. Here we report 4 cases of neutropenic enteritis in which ultrasound was used for diagnosis, and also for monitoring the clinical course of the disease. Because neutropenic enteritis is rapidly progressive, early diagnosis and therapeutic intervention are required. We believe that ultrasonography is a useful method for examining patients with neutropenic enteritis, being noninvasive, mobile, and providing rapid results in real time, thus aiding early diagnosis and clinical follow-up.

Homogenous simultaneous detection of HCV RNA and internal control by two-color fluorescence real-time monitoring of isothermal sequence amplification with INAF probes.

We demonstrated the homogenous simultaneous detection of HCV RNA and internal control by two-color fluorescence real-time monitoring of isothermal sequence amplification with INAF probes.

Frequent expression of the variant CD30 in human malignant myeloid and lymphoid neoplasms.

We earlier identified a variant of CD30 (CD30v) that retains only the cytoplasmic region of the authentic CD30. This variant is expressed in alveolar macrophages. CD30v can activate the nuclear factor-kappaB (NF-kappaB) as CD30, and its overexpression in HL-60 induced a differentiated phenotype. To better understand the physiological and pathological functions of CD30v, expression of this variant was examined using a multiple approach to examine 238 samples of human malignant myeloid and lymphoid neoplasms. Screening by reverse transcriptase-polymerase chain reaction (RT-PCR) revealed expression of CD30v transcripts in 52 of 72, 7 of 11, 63 of 90, and 7 of 30 samples of acute myeloid leukemia (AML), myeloid blast crisis of myeloproliferative disorders (MBC), and lymphoproliferative disorders (LPDs) of B- and T-cell origin, respectively. CD30v expression was high in monocyte-oriented AMLs (FAB M4 and M5), B-cell chronic lymphocytic leukemia (B-CLL), and multiple myeloma (MM). Using the specific antibody HCD30C2, prepared using a peptide corresponding to the nine amino acids of the amino-terminal CD30v, expression of CD30v protein was detected in 10 of 25 and 2 of 10 AML and ALL samples, respectively. In AMLs, immunocytochemical detection of CD30v revealed the presence of loose clusters of CD30v-expressing cells dispersed amid a population of CD30v-negative blasts. Finally, the parallel expression of CD30v mRNA and protein, as evidenced by Northern and Western blotting, was confirmed in selected cases of AMLs and LPDs. A significant correlation was found between expressions of CD30v and CD30 ligand transcripts in AML and LPD (P = 0.02, odds ratio = 3.2). The association of CD30v with signal-transducing proteins, tumor necrosis factor receptor-associated factor (TRAF) 2, and TRAF5 was demonstrated by coimmunoprecipitation analysis, as was demonstrated for authentic CD30 protein. Expression of transcripts for TRAF1, TRAF2, TRAF3, and TRAF5, as demonstrated by RT-PCR, was noted in leukemic blasts that express CD30v. Collectively, frequent expression of CD30v along with TRAF proteins in human neoplastic cells of myeloid and lymphoid origin provide supportive evidence for biological and possible pathological functions of this protein in the growth and differentiation of a variety of myeloid and lymphoid cells.

Primary gastric T-cell lymphomas: report of two cases and a review of the literature.

To understand more fully the clinicopathological features of primary gastric T-cell lymphomas (PGTL), we report two cases of PGTL and review the literature. The present cases were not associated with human T-cell leukemia virus type 1 (HTLV-1) and were at clinical stage IIE. In both cases, T-cell origin of the lymphoma cells was diagnosed immunohistochemically. The clinical courses of these two cases were different: one followed a very aggressive clinical course and the patient died 6 months after the diagnosis, whereas the other patient survived more than 2 years without adjuvant chemotherapy. Clinicopathological features of 23 patients with PGTL are summarized with regard to their differences from primary small intestinal T-cell lymphomas (PSITL) and by association with HTLV-1. The median age at onset of PGTL was 58 years. The gender ratio was male-dominant (M:F = 2.3:1). About two-thirds (10 of 17) of PGTL cases had evidence of HTLV-1 infection. The most common presenting symptom for PGTL was upper abdominal discomfort and/or pain (76%), whereas that in PSITL was weight loss (61%) and diarrhea (42%). Typical lesions for PGTL were large ulcerations at the corpus to antrum. Neoplastic cells had no typical morphological characteristics for PGTL including HTLV-1-associated cases. CD3+4+8- was the most frequently observed surface phenotype of PGTL cells. Laboratory findings at diagnosis were not informative. Most patients were treated by gastrectomy with or without chemotherapy. PGTL, excluding that with HTLV-1, showed better prognosis than PSITL, although PGTL with HTLV-1 had a poorer prognosis.

CD30: expression and function in health and disease.

CD30 was originally described as a marker of Hodgkin's and Reed-Sternberg cells in Hodgkin's lymphoma. Cloning and characterization of cDNAs encoding CD30 and its ligand (CD30L) established these proteins as members of the tumor necrosis factor receptor (TNFR) and tumor necrosis factor (TNF) superfamilies, respectively. Expression of CD30 is mostly restricted to virus-infected lymphocytes, neoplasms of lymphoid origin and a subset of activated T cells which produce Th2-type cytokines. The ligand is present on activated T cells, resting B cells, granulocytes, and the medulla of the thymus (epithelial cells and Hassal's corpuscles) as well as in various leukemia cells. The biological function of CD30 is pleiotropic but has come to be understood in the context of co-stimulatory signals. Signal transduction of CD30 utilizes signal transducers, TNFR-associated factors (TRAF1, 2, 3 and 5), which are shared by other TNFR family members. Mechanisms of signal transduction leading to diverse biological functions remain to be elucidated.

Evaluation of thrombopoiesis in thrombocytopenic disorders by simultaneous measurement of reticulated platelets of whole blood and serum thrombopoietin concentrations.

To evaluate thrombopoiesis in thrombocytopenic disorders, we simultaneously determined reticulated platelet counts in whole blood by FACScan flow cytometry and serum thrombopoietin (TPO) concentrations by a sensitive sandwich ELISA. The subjects were 40 healthy volunteers and 45 thrombocytopenic patients. In idiopathic thrombocytopenic purpura (ITP), the percentage of reticulated platelets was significantly elevated (5.61 +/- 2.02%: mean +/- SD) relative to normal controls (2.17 +/- 0.90%), but serum TPO concentrations (1.91 +/- 1.27 fmol/l) did not differ significantly from the normal range (1.43 +/- 0.62 fmol/l). The patients with aplastic anemia (AA) had decreased reticulated platelet counts and markedly increased serum TPO concentrations (13.65 +/- 10.64 fmol/l). In thrombocytopenic patients with liver cirrhosis (LC), the absolute number of reticulated platelets (1.65 +/- 1.11 x 10(9)/l) decreased similarly that in AA. However, serum TPO concentrations (1.38 +/- 0.50 fmol/l) did not increase in contrast to AA. Our findings suggested a possible dual mechanism of thrombocytopenia in LC; that is, thrombocytopenia in LC results from the decreased TPO production primarily in the liver adding to an increase in platelet sequestration in the spleen.

A novel domain in the CD30 cytoplasmic tail mediates NFkappaB activation.

About 100 amino acid residues in the C-terminal region are conserved among human, rat and murine CD30, a member of the tumor necrosis factor receptor (TNFR) superfamily, and can be separated into three subdomains with relatively higher conservation (D1, D2 and D3). Activation of NFkappaB by CD30 was shown to be mediated through interaction of TNFR-associated factor (TRAF) 1, 2 and 5 with the D2 and D3 subdomains. However, the function of the other conserved subdomain, D1, remained to be determined. Deletion of the D2 and D3 subdomains abolished interactions with TRAF2 and 5 but it did not affect NFkappaB activation. Reporter gene assays using deletion and mutant constructs of CD30 revealed that the D1 subdomain is sufficient for NFkappaB activation, without interaction with TRAF2 or 5, and that each subdomain alone can activate NFkappaB. Electrophoretic mobility shift assays revealed constitutive and CD30-induced NFkappaB activation in stable transformants of 293 cells expressing CD30 or a deletion mutant lacking D2 and D3 subdomains. Deletion of C-terminal 19 amino acid residues of the D1 subdomain abolished activation of NFkappaB. Substitution of alanine for one of the two threonine residues (amino acid position 524 and 529), one of which is a potential phosphorylation site in the D1 subdomain, also abolished the NFkappaB activation. Overexpression of the TRAF domain of TRAF2 or 5 had a dominant negative effect on the NFkappaB activation mediated by the D1 subdomain, thereby suggesting involvement of TRAF proteins in the signaling. Thus, the C-terminal 100 amino acid region of CD30 is composed of three independent functional subdomains, two of which contain binding sites for TRAF proteins. A novel domain in the cytoplasmic tail mediates NFkappaB activation, without direct interaction of TRAF2 or 5. Our observations suggest involvement of an unknown TRAF protein(s) in the signal transduction pathway of CD30.

F1 alpha: a novel mucin antigen associated with gastric carcinogenesis.

In a previous study, we obtained a novel monoclonal antibody (F1 alpha-75) directed against a synthetic mucin antigen termed F1 alpha, and demonstrated that this antigen was expressed in a high percentage (80.2%; 89/111) of gastric carcinomas. In the present study, we compared the expression of F1 alpha with that of sialyl-Tn antigen, a mucin antigen similar to F1 alpha, in 54 human early gastric carcinomas, intestinal metaplasia and adenomatous polyps of the stomach to determine how differences in the expression of these antigens correlated with gastric carcinogenesis. The rate of expression of F1 alpha in early gastric carcinoma tissues, 81.5%, was higher than that of sialyl-Tn antigen, 57.4%. No correlation was found between the rate of expression and histological type, depth of cancerous invasion or lymph node metastasis. Sialyl-Tn antigen was extensively expressed in 77.5% of specimens of complete intestinal metaplasia and in 78.6% of those of incomplete intestinal metaplasia; however, the expression of F1 alpha in those specimens was rare and sporadic, with rates of only 25.0 and 27.7%, respectively. In adenomatous polyps, the rate of expression of F1 alpha is 6.25% and that of sialyl-Tn antigen is 43.8%. Our findings indicate that F1 alpha is a more specific antigen for gastric cancer than sialyl-Tn antigen, and that F1 alpha is an antigen associated with carcinogenesis of the stomach.

Tumor necrosis factor receptor-associated factor (TRAF) 5 and TRAF2 are involved in CD30-mediated NFkappaB activation.

Signals emanated from CD30 can activate the nuclear factor kappaB (NFkappaB). The two conserved subdomains, D1 and D2, in the C-terminal cytoplasmic region of CD30 were tested for interaction with two tumor necrosis factor receptor-associated factor (TRAF) proteins with NFkappaB activating capacity, TRAF2 and TRAF5. TRAF5 is the newest member of the TRAF family that binds to lymphotoxin beta receptor and CD40. TRAF5, as well as TRAF2, interacted with the D2 subdomain of CD30 in vitro and in vivo. Deletion analysis by the yeast two-hybrid system revealed that the C-terminal 22 and 30 amino acid residues are dispensable for interaction of TRAF5 and TRAF2 with CD30, respectively. Substitution of alanine for threonine at 463 abolished the interaction with TRAF2. Overexpression of the TRAF domain of TRAF2 or TRAF5 showed a dominant negative effect on CD30-mediated NFkappaB activation. Simultaneous expression of these TRAF domains further suppressed the NFkappaB activation, suggesting an interplay of these TRAF proteins. Expression of TRAF2 and TRAF5 mRNA was demonstrated in T- and B-cell lines that express CD30. Taken together, our results indicate that TRAF2 and TRAF5 directly interact with CD30 and are involved in NFkappaB activation by CD30 signaling.

Cloning and characterization of a cDNA for rat CD30 homolog and chromosomal assignment of the genomic gene.

CD30 is a member of the tumor necrosis factor receptor superfamily, which is expressed on some activated lymphocytes, virus-infected cells and transformed lymphocytes. To facilitate our understanding of biological functions and functional domains, we isolated rat cDNA clones encoding the rat homolog of human CD30 from a cDNA library of a rat T-cell line, TARL-2. The nucleotide sequence of the cDNA showed 73% homology with that of human CD30. The deduced rat CD30 protein consisted of 493 amino acids with an M(r) of 59 160 and contained a single transmembrane domain. It lacked the second repeat of the cysteine-rich motif in the extracellular domain found in human CD30. The amino acid sequence showed 51.8 and 61.2% identity with the cysteine-rich and the cytoplasmic domains, respectively. In the cytoplasmic domain, however, the amino acid sequence was highly conserved in about 100 residues near the C-terminus showing 77.7% identity, whereas the rest of the cytoplasmic domain showed 45.2% identity. This conservation suggests the functional importance of this region. Comparison with the recently reported mouse CD30 revealed 83.7% conservation of the amino acid sequence and a common structure of the extracellular domain which lacks the second cysteine-rich motif. Northern blots revealed a 3.4-kb mRNA in the PHA-activated spleen cells and human T-cell leukemia virus type 1 (HTLV-1)-infected rat T-cell lines, whereas smaller transcripts of 2.3 kb were found in the lung. A rabbit polyclonal antibody raised against GST-fusion protein of the cytoplasmic domain detected bands with an apparent M(r) of 80 kDa and 100- 110 kDa expressed in TARL-2 and spleen cells. Transient overexpression of rat CD30 in TARL-2 cells activated HIV LTR in a NF-kappa B site-dependent manner, indicating that CD30 signals activate NF-kappa B. The chromosomal location of the gene was identified by fluorescence in situ hybridisation at 5q36.2, and appeared to correspond to human 1p36, where human CD30 has been mapped. The identification and characterization of the rat counterpart of human CD30 will facilitate studies of the biological function of this molecule.

A variant CD30 protein lacking extracellular and transmembrane domains is induced in HL-60 by tetradecanoylphorbol acetate and is expressed in alveolar macrophages.

We identified and cloned cDNAs for two novel CD30 mRNAs of 2.3 kb that are induced by 12-O-tetradecanoylphorbol 13-acetate (TPA) in the human myeloid leukemia cell line HL-60. These transcripts were transcribed from the intronic region just upstream of the exon coding for the transmembrane domain of the CD30 protein. The shorter cDNA had a deletion of 54 nucleotides corresponding to the 3' region of the transmembrane domain of the CD30 and which was probably caused by alternative splicing. Translation of these transcripts appeared to start from the internal methionine codon at nucleotide position 289 that corresponds to that of 1612 in the CD30 cDNA, and encode a protein of 132 amino acid residues which corresponds exactly to the C-terminal cytoplasmic domain of CD30 protein. The calculated molecular mass of this variant CD30 (CD30v) protein was 14,087. Thus, the predicted CD30v protein retains most of the cytoplasmic region, but lacks the extracellular and transmembrane domains. Northern blots detected the expression of CD30v transcripts only in the lung and the TPA-stimulated HL-60 cell line. Translation of this mRNA in vitro produced a protein of 25 kD. Immunoblotting analysis with HCD30C1, a rabbit polyclonal antibody raised against the cytoplasmic domain of CD30 protein, detected proteins with an apparent Mr 25 kD expressed in TPA-stimulated HL-60 and COS-7 cells that were transfected with both types of CD30v cDNAs. Constitutive phosphorylation of the CD30v protein was demonstrated by in vitro labeling with [32P]. Immunohistochemical studies demonstrated CD30v protein was in alveolar macrophages. Cotransfection experiments using a kappa B-site-dependent reporter construct showed that CD30v can transactivate gene expression through activation of NF kappa B, as was noted on the authentic CD30 protein. Overexpression of the CD30v induced differentiation of HL-60 cells as evidenced by an increased NBT reduction activity. These observations provided new insights into the molecular heterogeneity and biological function of CD30 in myeloid cells.