Activin, a member of the transforming growth factor-beta superfamily, regulates various physiological functions. In the present study, we investigated the effect of activin on neuronal differentiation, particularly the functional activity of voltage-dependent Ca2+ channels, in murine neuroblastoma C1300 cells. A slight K(+)-induced increase in the intracellular free Ca2+ ([Ca2+]i) was observed in C1300 cells untreated and treated with either activin A or all-trans-retinoic acid, while treatment with both agents significantly enhanced the increase. The [Ca2+]i increases potentiated by activin A and all-trans-retinoic acid were nearly abolished in the presence of 1.0 mM nickel or in the absence of extracellular Ca2+. Nifedipine (0.1 microM) and omega-conotoxin (1.0 microM), inhibitors of L- and N-type Ca2+ channels, respectively, partially inhibited these responses, however the inhibitory effects of these compounds were not additive. In addition, Bay K 8644, an activator of L-type Ca2+ channels, enhanced the K(+)-induced [Ca2+]i increase. These findings indicated that depolarization evoked the Ca2+ influx, at least in part, through L-type Ca2+ channels in C1300 cells treated with both activin A and all-trans-retinoic acid.

3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethy↗

PubMed1997

Presence of B cell progenitors in the thymus.

We characterize B cell progenitors in the thymus. Although mature thymic B cells are surface Ig+, B220(high), but CD43-, B cell progenitors in the thymus were found to be slg-, B220(med), and CD43+. Most progenitors showed rearranged Ig D-J and V-D-J patterns when DNA from sorted B cell progenitors was amplified by PCR, blotted, and probed. When B cell progenitors were purified from the thymus and injected intrathymically into Ig heavy chain (Igh) allotype-disparate recipients, B cells bearing donor-type Igh6 were detected in the thymus but not in the periphery. Thymic B cells generated from these progenitors were CD5+ cells, although there was a broad range of expression of CD5 molecules. Furthermore, B cells purified from thymus that had been inoculated with B cell progenitors were able to differentiate into Ab-forming cells under the influence of CD40 ligand plus IL-10, and secreted IgM with donor Igh6 allotype. We thus clarified the existence of B cell progenitors in the thymus and also characterized the surface markers and their developmental functions.

Animals↗

PubMed1997

Tyrosine phosphorylation and p72syk activation by an anti-glycoprotein Ib monoclonal antibody.

NNKY5-5, an IgG monoclonal antibody directed against the von Willebrand factor-binding domain of glycoprotein (GP) Ib alpha, induced weak but irreversible aggregation (or association) of platelets in citrate-anticoagulated platelet-rich plasma. This phenomenon was defined as small aggregate formation (SAF). Platelets in hirudin-anticoagulated plasma or washed platelets showed little response to NNKY5-5 alone, but the antibody potentiated aggregation induced by low concentrations of adenosine diphosphate or platelet-activating factor. NNKY5-5 did not induce granule release or intracellular Ca2+ mobilization. However, NNKY5-5 caused tyrosine phosphorylation of a 64-kD protein and activation of a tyrosine kinase, p72syk. An anti-Fc gamma II receptor antibody had no effect on SAF, suggesting that NNKY5-5 activated platelets by interacting with glycoprotein Ib. Fab' fragments of NNKY5-5 did not induce SAF, but potentiated aggregation induced by other agonists. The Fab' fragment of NNKY5-5 induced the activation of p72syk, suggesting that such activation was independent of the Fc gamma II receptor. Cross-linking of the receptor-bound Fab' fragment of NNKY5-5 with a secondary antibody induced SAF. GRGDS peptide, chelation of extracellular Ca2+, and an anti-GPIIb/IIIa antibody inhibited NNKY5-5-induced SAF, but had no effect on 64-kD protein tyrosine phosphorylation or p72syk activations. Various inhibitors, including aspirin and protein kinase C, had no effect on SAF, protein tyrosine phosphorylation, or p72syk activation. In contrast, tyrphostin 47, a potent tyrosine kinase inhibitor, inhibited NNKY5-5-induced SAF as well as tyrosine phosphorylation and p72syk activation. Our findings suggest that binding of NNKY5-5 to GPIb potentiates platelet aggregation by facilitating the interaction between fibrinogen and GPIIb/IIIa through a mechanism associated with p72syk activation and tyrosine phosphorylation of a 64-kD protein.

Antibodies, Monoclonal↗

PubMed1997

A recurring translocation, t(3;6)(q27;p21), in non-Hodgkin's lymphoma results in replacement of the 5' regulatory region of BCL6 with a novel H4 histone gene.

3q27 translocations affecting the BCL6 gene can involve not only immunoglobulin genes (IG) but also other as yet uncharacterized chromosomal loci as partners. Here, we describe cloning of the junctional area of a recurring translocation, t(3;6)(q27;p21), in non-Hodgkin's lymphoma of B-cell type and isolation of clones from 6p21; high resolution fluorescence in situ hybridization mapped the clones to sub-band 6p21.3. Nucleotide sequence analysis of a fragment from the junctional area of 6p21 revealed the presence of a novel H4 histone gene that was included in the histone gene cluster on this particular region, and the same fragment detected approximately 380-bp transcripts in hematological tumor cells. Breakpoints on 3q27 of two cases carrying t(3;6) were immediately 3' of the BCL6 exon 1, and the H4 histone gene was substituted for the 5' regulatory elements of BCL6. Because H4 gene expression is tightly coupled to DNA replication, this study suggested an immediate mechanism for deregulated expression of BCL6, leading to the development of non-Hodgkin's lymphoma.

Base Sequence↗

PubMed1997

Microparticles and coronary artery disease.

Explore the source record for details and available documents.

Biomarkers↗

PubMed1997

Distinct qualitative differences between normal and abnormal hemopoietic stem cells in vivo and in vitro.

The transplantation of partially purified hemopoietic stem cells (HSCs) plus the engraftment of bone from autoimmune-prone mice ((NZW x BXSB)F1 (W/BF1) mice) induces autoimmune diseases in major histocompatibility complex (MHC)-incompatible normal C3H/HeN mice. In contrast, W/BF1 mice die of infection or anemia within three weeks due to a failure in hemopoietic reconstitution when the mice receive partially purified HSCs plus bones from normal C3H/HeN mice, although they survive more than a year without showing any symptoms of autoimmune diseases when they receive T cell-depleted bone marrow cells (without bone grafts) from normal mice. This finding suggests that abnormal HSCs can proliferate even in MHC-incompatible microenvironments, while normal HSCs cannot. This is confirmed by spleen colony-forming assays (CFU-S) on day 12, using pluripotent HSCs (P-HSCs). The P-HSCs of old (> 4 mo) W/BF1 mice (after the development of autoimmune diseases) form high CFU-S counts on day 12 even in the allogeneic C3H environment, although the P-HSCs of normal mice form high CFU-S counts only in the MHC-compatible environments. In addition, abnormal P-HSCs of autoimmune-prone mice can proliferate in vitro in collaboration with MHC-incompatible stromal cells, although normal HSCs do so in collaboration with MHC-compatible stromal cells, but not MHC-incompatible stromal cells. These findings indicate that abnormal P-HSCs are more "resilient" than normal P-HSCs.

Animals↗

PubMed1997

Transfer of autoimmune thyroiditis and resolution of palmoplantar pustular psoriasis following allogeneic bone marrow transplantation.

We report an unusual case of a patient who was cured of one autoimmune disease (palmoplantar pustular psoriasis (PPP)) but developed another autoimmune disease (autoimmune thyroiditis) after allogeneic BMT. A 40-year-old man suffering from AML with PPP underwent allogeneic BMT from his HLA-identical sister for the treatment of AML. The patient experienced complete clearance of the cutaneous PPP despite the cessation of immunosuppressive therapy for over 2 years. However, he developed hyperthyroidism with anti-thyroglobulin antibodies 5 months after BMT, although he had showed normal thyroid functions without anti-thyroglobulin antibodies before BMT. The donor had no history of thyroid diseases and showed normal thyroid functions but was positive for anti-thyroglobulin antibodies. Thus, even when the donor is in a subclinical state, autoimmune thyroiditis may be transferred from donors to recipients by BMT.

Adoptive Transfer↗

PubMed1997

[Clinical efficacy of lomefloxacin for associated infection in patients with hematological diseases].

We have studied the clinical effect of lomefloxacin (LFLX) for the documented infections in the patients with hematological disorders, and also analyzed the prophylactic usefulness of LFLX for the prevention of succeeding infection after the chemotherapy. Fifty five patients were entered in the trial, and 51 patients were eligible. Among 51 eligible patients, 40 patients were suffered from accompanied infections, and 11 patients were registered for the prophylaxis of the infection. In the group of documented infection, the ratio of out-patients was 62.5%, and 63.0% in prophylactic usage. In the treatment of the documented infection, LFLX was effective in 20 patients; the efficacy rate was 50.0%. In the prophylactic administration, LFLX was effective in 9 patients, yielded the efficacy rate of 81.8%. LFLX was effective for all 5 patients with urinary tract infection, in 10 out of 18 patients with respiratory tract infection (efficacy rate; 55.6%), in 5 out of 12 patients with fever from undetermined origin (41.7%), showed no effect for cholecystitis, colitis, and phlegmon. Bacteriological examinations revealed that all of the bacteria detected as pathogens were eradicated. The efficacy rate in the group of the malignant disorders such as leukemia/ lymphoma was smaller than that of non-tumorigenic diseases as aplastic anemia. As myelodysplastic syndrome (MDS), four infection-bearing patients and five patients with prophylactic usage were analyzed. The efficacy rate of LFLX was 50.0 and 80.0%, respectively, and the overall efficacy rate was 66.7%. All MDS patients without prophylactic administration failed to have infections. Thus, LFLX was thought to be useful in the prevention of succeeding infections after the chemotherapy. No clinical and laboratory adverse reactions were reported.

Adolescent↗

PubMed1997

Medical decisions concerning the end of life: a discussion with Japanese physicians.

OBJECTIVES: Life-sustaining treatment at the end of life gives rise to many ethical problems in Japan. Recent surveys of Japanese physicians suggested that they tend to treat terminally ill patients aggressively. We studied why Japanese physicians were reluctant to withhold or withdraw life-support from terminally ill patients and what affected their decisions. DESIGN AND PARTICIPANTS: A qualitative study design was employed, using a focus group interview with seven physicians, to gain an in-depth understanding of attitudes and rationales in Japan regarding medical care at the end of life. RESULTS: Analysis revealed that physicians and patients' family members usually make decisions about life-sustaining treatment, while the patients' wishes are unavailable or not taken into account. Both physicians and family members tend to consider withholding or withdrawing life-sustaining treatment as abandonment or even killing. The strongest reason to start cardiopulmonary resuscitation- and to continue it until patients' family members arrive-seems to be the family members' desire to be at the bedside at the time of death. All physicians participating in our study regarded advance directives that provide information as to patients' wishes about life-sustaining treatment desirable. All expressed concern, however, that it would be difficult to forego or discontinue life-support based on a patient's advance directive, particularly when the patient's family opposed the directive. CONCLUSION: Our group interview suggested several possible barriers to death with dignity and the appropriate use of advance directives in Japan. Further qualitative and quantitative research in this regard is needed.

Adult↗

PubMed1997

Aplastic anemia complicating Sjögren's syndrome.

A 47-year-old woman was referred to our hospital because of severe anemia and polyclonal gammopathy. She developed sicca syndrome after admission. Laboratory data revealed pancytopenia (white blood cells, 2,800/microliter; hemoglobin, 6.4 g/dl; platelets, 6.1 x 10(4)/microliter) and hyper gamma globulinemia (5.2 g/dl), and bone marrow was hypoplastic. Histology of the salivary gland showed infiltration of lymphocytes. We report a good response to immunosuppressive therapy in a rare case of aplastic anemia complicating Sjögren's syndrome.

Anemia, Aplastic↗

PubMed1997

Polyangiitis overlap syndrome.

A 33-year-old man was admitted to our hospital because of intermittent claudication and finger tip ulceration with a skin rash on the upper and lower extremities. He later developed a massive melena. Angiography revealed arterial occlusion in the hand and foot, skin biopsy showed vasculitis with eosinophilic infiltration, and biopsy of the colon showed mucosal vasculitis with thrombosis. A diagnosis of polyangiitis overlap syndrome was made, and all these symptoms improved after corticosteroid therapy.

Adult↗

PubMed1997

Significance of rearrangement of the BCL6 gene in B-cell lymphoid neoplasms.

Chromosomal translocations involving 3q27 are among the most common recurring translocations in non-Hodgkin's lymphoma (NHL) of B-cell phenotype. Molecular cloning of junctional areas of the translocations resulted in isolation of the BCL6 gene adjacent to the breakpoint cluster on 3q27. The gene encodes a zinc-finger transcription factor which is expressed in nuclei of germinal center B-cells. Rearrangement of BCL6 was observed in 6.4 to 14.3% of follicular lymphomas and 28.6 to 35.5% of diffuse large cell lymphomas; regarding the latter, a Japanese series showed a lower incidence. Survival curves suggested that NHL carrying rearrangement of BCL6 and lacking that of BCL2 is curable by chemotherapy. Detailed analysis of the vicinity of translocations showed that the 5' untranslated region of BCL6 was replaced by heterogeneous promoters not only from immunoglobulin genes but also from many previously uncharacterized loci. Bcl-6 protein is expressed in NHL of follicular center B-cell origin, independently of the presence or absence of BCL6 rearrangement. At present, limited information is available about the functional consequences of the rearrangements and, in particular, about their ultimate implications for lymphomagenesis.

Chromosomes, Human, Pair 3↗

PubMed1997

[An elderly case whose residual malignant lymphoma was completely remitted by oral etoposide treatment using unusual dosing schedule].

In a 72-year-old man with malignant lymphoma (Hodgkin's disease, nodular sclerosis type, Stage III S), complete remission was induced by intravenous drip of adriamycin and oral administration of etoposide. After that, a maintenance dose of etoposide (25 mg) was administered every 3 days without observable side effects. From these results, we considered that the dose level and interval of administration are both important for chemotherapy in elderly patients.

Administration, Oral↗

PubMed1997

Rearrangement of the BCL6 gene in B-cell lymphoid neoplasms.

We report here a large series of B-cell neoplasms with regard to rearrangement of the BCL6 gene on chromosome band 3q27. Southern blot analysis using probes from the major translocation cluster (MTC) region of the BCL6 revealed rearrangement in 32 of a total of 222 patients with various subtypes of B-cell neoplasm. In non-Hodgkin's lymphoma (NHL), rearrangements of the BCL6 gene were not closely associated with a specific histopathologic subtype but distributed in subcategories in the Working Formulation. A comparative study between NHL associated either with BCL2 or BCL6 rearrangement showed that advanced disease and bone marrow involvement were more frequent in BCL2(+) NHL. In contrast, extranodal involvement was more frequently observed in the BCL6(+) NHL. The survival curve of BCL6(+) NHL was characterized by a rapid decline followed by a plateau. Of the total of 32 BCL6(+) patients, 6 carried both BCL2 and BCL6 rearrangements, and showed clinicopathological properties of follicular lymphoma. This study suggests that BCL6 rearrangement is primarily associated with large cell lymphoma, and that BCL2(-)BCL6(+) NHL could potentially be curable with modern combination chemotherapy.

Bone Marrow↗