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S Nagafuchi

Publications and source records attributed to S Nagafuchi.

At least 37 records · Page 2Linked to original sources
PubMed1997

T cells bearing Vbeta8 are preferentially infected with exogenous mouse mammary tumor virus.

We previously reported that a mouse mammary tumor virus (MMTV(II-TES14)), encoding a superantigen specific for TCR Vbeta14, can infect lymph node (LN) cells of mice in an I-E-independent manner. Here we examined the kinetics of cell types infected with exogenous MMTV in the draining LN after s.c. injection of II-TES milk containing MMTV(II-TES14). The infectivity was assessed in LN cells sorted into each cell subset by a semiquantitative analysis of MMTV provirus using PCR with a primer specific for MMTV(II-TES14). Only B cells in the LN were infected by the MMTV on day 6 after injection, but CD8+ T cells and, to a lesser extent, CD4+ T cells were also found to be detectably infected on day 14 after the injection of II-TES milk. Among the T cells we examined, Vbeta8 T cells were most preferentially infected with MMTV, but no Vbeta14 T cells specific for MMTV(II-TES14) superantigen were infected on day 14 after infection. The transfer of Vbeta8 T cells sorted from mice injected with II-TES milk 14 days previously resulted in the deletion of CD4+ Vbeta14 T cells and in the MMTV infection of normal B6 mice. No MMTV infection of T cells occurred in IgM knockout mice, which lack a mature B cell compartment. These results suggest that MMTV surviving in B cells is transferred to Vbeta8 T cells, which may play an important role in MMTV longevity.

Animals↗
PubMed1997

Heterogeneity of systemic extra-nodal Epstein-Barr virus-associated lympho-histiocytic tumor--ten autopsy cases of human immunodeficiency virus-negative Japanese.

Epstein-Barr virus associated T-Cell lymphoma mimicking malignant histiocytosis (MH) has been previously reported. We selected 10 autopsy cases of extranodal lymphoma or histiocytic tumor, which showed an EBV presence in the tumor cells as well as a fulminant clinical course. The detailed clinicopathologic features were thus clarified. A retrospective study was performed on ten adult patients, eight males and two females, and almost all cases presented with a fulminant clinical course, revealing pancytopenia, liver dysfunction and disseminated intravascular coagulopathy. Immunophenotypic and genotypic studies along with in situ hybridization (ISH) were performed. The autopsy findings mainly showed extra nodal involvement in the liver (10 patients), spleen (9 patients), intestinal tract (5 patients), bone marrow (5 patients), nasal cavity, lungs, adrenal glands, kidneys (2 patients) and brain. Histologically atypical pleomorphic lymphoid cells were observed to infiltrate with reactive histiocytes, some of which showed hemophagocytosis. Based on the histological and clinical findings, diagnosis of malignant histiocytosis was made. ISH showed an EBV-presence in almost all the tumor cells. The immunophenotype and/or genotype studies demonstrated T-cell lymphoma (2 patients), Histiocytic tumors (2 patients), B-cell lymphoma (1 patients), natural killer (NK) cell lymphoma (3 patients), and T/NK lymphoma (2 patients), in which T or NK could not be confirmed, due to a lack of fresh materials. Based on the above findings, the histological appearance of EBV-associated MH previously defined was shown to be common to extra-nodal malignant lymphomas having origin in various organs, although the cytological and genetic features were heterogenous.

Adolescent↗
PubMed1997

Direct evidence for the contribution of B cells to the progression of insulitis and the development of diabetes in non-obese diabetic mice.

The non-obese diabetic (NOD) mouse is an excellent animal model of autoimmune diabetes associated with insulitis. The progression of insulitis causes the destruction of pancreatic beta cells, resulting in the development of hyperglycemia. Although it has been well documented that T cells are required for the development of insulitis and diabetes in NOD mice, the importance of B cells remains unclear. To clarify the role of B cells in the pathogenesis of NOD mice, we therefore generated B cell-deficient NOD (B-NOD) mice. Surprisingly, none (of 13) of the B-NOD mice developed diabetes by 40 weeks of age, while the control littermates with B cells (B+NOD) suffered from a high proportion (43 of 49) of diabetes. The insulin reactivity of B+NOD mice was significantly impaired, while the B-NOD mice showed a good insulin response, thus suggesting the pancreatic beta cell function to be well preserved in B-NOD mice. Although B-NOD mice did develop insulitis, the extent of insulitis was significantly suppressed. These data thus provide the direct evidence that B cells are essential for the progression of insulitis and the development of diabetes in NOD mice.

Animals↗
PubMed1997

[Immunodeficiency and carcinogenesis in patients with chronic active Epstein-Barr virus infection].

Three adult patients with chronic active Epstein-Barr virus infection (CAEBV) had high anti-EBV-VCA antibody, positive anti-EA, low anti-EBNA and were associated with systemic lymphadenopathies and immunosuppression. The case 1 and 2 had elevated serum immunoglobulin levels, and recurrent infections, and case 3 showed pancytopenia. These 3 cases developed both EBV and latent membrane protein (LMP) positive malignant histiocytosis, EBV positive but LMP negative plasmacytoma, and EBV negative acute myelogeneous leukemia, respectively. It was suggested that CAEBV belonged to high risk groups for the development of malignant neoplasms. Since HLA of the case 1 and his father was identical, we conducted a in vitro cytotoxicity test using EBV transformed autologous B lymphocytes, K562 cells, and Raji cells to clarify the association of immunosuppression and HLA. The case 1 showed a low level of specific cytotoxicity to autologous EBV transformed B cells, while his parents were negative for the specific cytotoxicity. The patient and his parents developed inducible cytotoxicity to all targets after in vitro incubation of peripheral mononuclear cells with recombinant interleukin 2 (rIL-2) for 7 days. The patient and his mother showed lower enhancement of cytotoxicity, while HLA identical father could induce good cytotoxic activity to all targets as well as normal controls, indicating that a low IL-2 induced cytotoxic activity observed in CAEBV was independent of HLA associated immunoregulation at least in the case 1. Further studies are required to clarify the exact mechanisms responsible for the development of CAEBV.

Adult↗
PubMed1996

A unique origin and multistep process for the generation of expanded DRPLA triplet repeats.

Dentatorubral and pallidoluysian atrophy (DRPLA) is an autosomal dominant neurodegenerative disorder associated with the expansion of a CAG repeat at chromosome band 12p13. Epidemiological studies have demonstrated an increased prevalence of DRPLA in Japan, although several DRPLA kindreds of non-Japanese ancestry have been identified. To define the molecular basis for this geographic variation in prevalence, we have analyzed haplotypes around the repeat in several different ethnic groups. Two intragenic biallelic polymorphisms distinguished three haplotypes, each of which formed a predominant haplotype found in the three major racial populations. All the expanded repeats of Japanese and Caucasian patients studied were associated with a particular haplotype, which otherwise was associated with longer repeats commonly found in Asians. Our results support a multi-step model for repeat expansion, and suggest that expanded DRPLA repeats may have evolved from an ancient chromosomal haplotype of Asian origin. We also propose that a combination of a highly polymorphic microsatellite marker with relatively stable biallelic markers in a range of PCR amplification is a powerful tool for studies on human genome diversity, which may reveal the ancient human migration and the formation of ethnic groups.

Black or African American↗
PubMed1995

Yeast artificial chromosome (YAC)-based genome mapping of Schistosoma mansoni.

Schistosoma mansoni has 7 pairs of autosomal chromosomes and one pair of sex chromosomes (ZZ for a male worm and ZW for a female), of a haploid genome size of 2.7 x 10(8) bp. We initiated the molecular genetic approach for the detailed characterization and understanding of the evolutionary biology of schistosomes. We have constructed a yeast artificial chromosome (YAC)-library with partially digested parasite genomic DNA, and the chromosome location of each insert was detected by fluorescent in situ hybridization (FISH). The library contains > 2283 clones with an average insert size of 358 kb, which represents a 2.6-fold coverage of the genome (> 7.2 x 10(8) bp). 100 randomly selected YAC clones were localized by FISH and found to be distributed widely among all chromosomes. The assembly of 14 YACs distributed almost the whole region of chromosome 3. Generated expressed sequenced tags (ESTs) derived from a unidirectional cDNA library were also used for further characterization of the YAC inserts. These results indicate that an extensive contig assembly of the entire chromosomes and a reasonably detailed gene map should be feasible in the near future.

Animals↗
PubMed1995

Malignant histiocytosis derived from a common histiocyte clone in a patient with chronic Epstein-Barr virus infection.

Epstein-Barr virus (EBV) has a particular propensity for B lymphocytes, but in a few cases it seems to play a role in histiocytic disorders and EVB DNA has been identified in histiocytes. To determine what kind of cell proliferate clonally, we studied a patient with malignant histiocytosis that developed after chronic EBV infection. Polymerase chain reaction (PCR) for lymphocyte-defined membrane antigen (LYDMA) of EBV, a marker of monoclonality, double stainings of cell markers (B, T lymphocytes; histiocytes), and in situ hybridization for EBV were performed in tissues obtained in 1987 and 1990 before the appearance of malignant histiocytosis and in 1991 after the disease was diagnosed. PCR for LYDMA from multiple samples during the disease showed the same single band, indicating that chronic EBV infection and malignant histiocytosis were caused by the same single virion. We also found a single terminal repeat band of EBV which supports this finding. In the studies of double stainings, EBV was present in histiocytes of the non-neoplastic early stage, and in the neoplastic cells of malignant histiocytosis. The histiocyte, infected with EBV, clonally expanded to result in malignant histiocytosis.

Adolescent↗
PubMed1994

Budd-Chiari syndrome and Epstein-Barr virus (EBV) associated plasmacytoma in a patient with chronic active EBV infection.

A 42-year-old Japanese man with chronic active Epstein-Barr virus (EBV) infection initially responded to treatment with interleukin-2 (IL-2). Six months later he developed thrombosis in the hepatic veins, and Budd-Chiari syndrome associated with severe hepatic damage was diagnosed. He also developed a solitary EBV-positive plasmacytoma in the right femur. Since these rare complications occurred after long-term IL-2 therapy, the possibility that long-term IL-2 therapy might cause Budd-Chiari syndrome and liver damage as well as EBV-associated plasmacytoma is discussed.

Adult↗
PubMed1994

Dentatorubral and pallidoluysian atrophy expansion of an unstable CAG trinucleotide on chromosome 12p.

Dentatorubral and pallidoluysian atrophy (DRPLA) is an autosomal dominant neurodegenerative disorder characterized by combined systemic degeneration of the dentatofugal and pallidofugal pathways. We investigated a candidate gene and found that DRPLA patients had an expanded CAG trinucleotide repeat in a gene on the short arm of chromosome 12. The repeat size varied from 7-23 in normal individuals. In patients one allele was expanded to between 49-75 repeats or occasionally even more. Expansion was usually associated with paternal transmission and only occasionally with maternal transmission. Repeat size showed a close correlation with age of onset of symptoms and disease severity. We conclude that DRPLA is the seventh genetic disorder known to be associated with expansion of an unstable trinucleotide repeat.

Alleles↗
PubMed1994

Structure and expression of the gene responsible for the triplet repeat disorder, dentatorubral and pallidoluysian atrophy (DRPLA).

Dentatorubral and pallidoluysian atrophy is associated with expansion of an unstable CAG repeat on chromosome 12p. We have determined the nucleotide sequences of overlapping cDNA clones and deduced the gene structure. The gene is ubiquitously expressed to form a single 4.5 kb transcript and encoded by an open reading frame of 1184 amino acids (aa), in which a polyglutamine track with variable length starts at aa 484. Although the predicted amino acid sequence does not reveal any function, it does contain several interesting motifs consisting of a simple repeated amino acid sequence, a homo-proline track, two stretches of arginine-glutamic acid dipeptides and a stretch of alternative histidine residues. These results provide clues toward understanding neurodegenerative diseases associated with triplet repeat expansion.

Atrophy↗
PubMed1994

Molecular cloning of cDNA encoding the precursor for hamster hypothalamic growth hormone-releasing factor.

The structure of rat and mouse growth hormone-releasing factor (GRF) peptide and precursor shows considerable divergence from that of the human counterpart and also within rodents themselves. To study such structural divergence in another rodent, we cloned a cDNA encoding the GRF precursor from golden hamster. The hamster GRF (haGRF) cDNA clone had an open-reading frame that predicts a haGRF precursor protein with 107 amino acids. The haGRF precursor bore greater overall homology (82%) to the human than the same rodent homologue (58-64%) and contained two processing sites identical to the human sequence that would generate mature haGRF peptide. Furthermore, the haGRF peptide, like human but unlike rat or mouse GRF, consisted of 44 amino acids and also had greater homology to the human (89%) than the rodent sequence (64-75%), conserving a Tyr residue at the N-terminus and an amidated Leu residue at the C-terminus. Thus, both haGRF precursor and peptide are structurally more related to those of human than of other rodents, suggesting that rodent GRF precursor diverged from the human sequence at differential rates within the species.

Animals↗
PubMed1993

A chromosome 11 YAC library.

A targeted yeast artificial chromosome (YAC) library for chromosome 11 has been constructed from the J1 cell line that carries a single human chromosome 11 within a hamster DNA background. Interspecies chimeric clones generated during construction of the library were detected during the screening process and eliminated from the library. Contig assembly becomes much less difficult using such a library as the complexity is decreased and the ends of the clone inserts can be rescued for walking to neighboring clones. The library contains > 1824 clones with an average insert length of 337 kb. This represents a fourfold coverage of chromosome 11 or a > 95% chance of recovering a unique single-copy sequence from the library. Two hundred YAC clones were localized by fluorescence in situ hybridization and found to be randomly distributed along the chromosome. The library has been screened with probes for the chromosome 11 markers HBB, GLUR4, H19, and D11S193. Corresponding YAC clones have been isolated for each locus. This analysis has indicated that the library is unbiased, that cognate YAC clones can be recovered with chromosome 11 markers, and that extensive contig assembly should be feasible.

Animals↗
PubMed1993

Production of anti-cardiolipin antibody in AKR/J mice with streptozocin-induced insulitis and diabetes.

We herein report that anti-cardiolipin antibodies (ACA) were detected in AKR/J mice treated with multiple low doses of streptozocin (STZ)-induced insulitis and diabetes. Daily intraperitoneal (i.p.) injections of 40 mg/kg body wt. of STZ for five consecutive days in the AKR/J mice resulted in hyperglycemia and mononuclear cell infiltrations of islets (insulitis). ACA appeared on day 14, when hyperglycemia began to occur, at a rate of 13.3% (4/30). The rate increased to 83.3% (25/30) on day 21, when diabetes developed, and then fell to 10% (3/30) on day 28. Neither the diabetic AKR/J mice treated with a single high dose of STZ (200 mg/kg body wt.) nor the non-diabetic insulitis free Balb/c mice and B10.S(9R) mice treated with multiple low doses of STZ (40 mg/kg body wt.) produced ACA. The IgG subclass of the ACA belonged mainly to IgG2a. These findings suggest that ACA are produced in association with the development of insulitis, but not induced by either hyperglycemia or STZ.

Animals↗