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Biomedical subjects

N Sakaguchi

Publications and source records attributed to N Sakaguchi.

At least 145 records · Page 8Linked to original sources
PubMed1990

[Laboratory and clinical studies on norfloxacin in the pediatric field].

In bacteriological, pharmacokinetic and clinical studies on norfloxacin (NFLX, AM-715), the following results were obtained: 1. Antibacterial activity of NFLX, nalidixic acid (NA), amoxicillin (AMPC), cefaclor (CCL), erythromycin (EM) and fosfomycin (FOM) against clinically isolated bacteria was examined, and it was found that MIC80 of NFLX against Staphylococcus aureus was 3.13 micrograms/ml, thus NFLX exhibited stronger antimicrobial activity than NA, AMPC, CCL, EM and FOM. NFLX also showed good activities to those strains of S. aureus which were resistance to NA, AMPC, CCL, EM and FOM. 2. MIC80 of NFLX against Escherichia coli was 0.05 micrograms/ml or lower, thus NFLX showed better activity than NA, AMPC, CCL, EM and FOM. 3. In single oral administration at fasting of NFLX at dose levels of 1.5-2.4 and 2.5-3.4 mg/kg in tablet form mean peak values of serum concentration were 0.32 micrograms/ml reached in 1 hour and 0.38 micrograms/ml in 2 hours, T1/2's obtained were 1.7-4.0 and 2.2-2.9 hours and AUC's were 1.54 +/- 0.52 and 2.02 +/- 0.93 micrograms.hr/ml, respectively. Urinary recovery rates of 11.6-46.9%, 13.8-35.4% in 6-8 hours were demonstrated with the 2 ranges of dose levels, respectively. 4. NFLX was administrated to 34 patients consisting of 8 cases of acute pneumonia, 3 cases of acute tonsillitis, 3 cases of bacterial colitis, 19 cases of urinary tract infections and 1 case of purulent parotitis. The clinical efficacy rate was 97.1% including 34 cases with excellent results in 28, good in 5 and fair in 1. 5. The bacterial eradication rate was 96.8% (30/31) with one exception of a Campylobacter jejuni strain. 6. NFLX was given to patients according to a dosing regimen with 4.5-21.4 mg/kg/day dose levels for 3 doses daily except 1 case of UTI where 2 daily doses were given daily. 7. No adverse reactions were observed. Abnormal laboratory test value was obtained in 1 case where eosinophilia was found. The above results have suggested that NFLX is a useful and safe antimicrobial agent against bacterial infections in children.

Adolescent↗
PubMed1989

Organ-specific autoimmune disease induced in mice by elimination of T cell subsets. V. Neonatal administration of cyclosporin A causes autoimmune disease.

Cyclosporin A (CsA), a potent immunosuppressive drug, caused organ-specific autoimmune disease, such as gastritis with anti-parietal cell autoantibodies or oophoritis with anti-oocyte autoantibodies, in BALB/c mice when the drug was administered daily for 1 wk to newborns. Administration to adult mice did not. CsA abrogated the production of L3T4+ T cells and Lyt-2+ T cells in the thymus. Consequently, these T cells were substantially depleted from the peripheral lymphoid organs, especially when the drug was administered from the day of birth. Autoimmune disease was prevented when CsA-treated newborn mice were inoculated with splenic T cells from normal syngeneic mice. However, removal of the thymus immediately after neonatal CsA treatment produced autoimmune disease with a higher incidence and in a wider spectrum of organs, i.e., thyroiditis, sialoadenitis of the salivary gland, gastritis, insulitis of the endocrine pancreas, adrenalitis, oophoritis, or orchitis. Each autoimmune disease was accompanied by the development of circulating autoantibodies specific for the corresponding organ Ag. Immunopathology of these autoimmune diseases was quite similar to that of human organ-specific autoimmune diseases.

Animals↗
PubMed1988

Thymus and autoimmunity. Transplantation of the thymus from cyclosporin A-treated mice causes organ-specific autoimmune disease in athymic nude mice.

Organ-specific autoimmune diseases such as gastritis, oophoritis, thyroiditis, or insulitis developed in athymic nu/nu mice after engraftment of the thymus from euthymic nu/+ mice treated with cyclosporin A (CsA), a potent immuno-suppressant. The development of autoimmune disease in the nu/nu mice was prevented by inoculation of thymocyte suspensions prepared from normal nu/+ mice, but not by thymocyte suspensions from CsA-treated nu/+ mice. Cotransplantation of normal nu/+ mouse thymus with CsA-treated thymus also suppressed the development of autoimmune disease. Inoculation of spleen cell suspensions prepared from normal adult nu/+ mice prevented autoimmune disease, but inoculation of those from newborn nu/+ mice did not. Thus, CsA appears to interfere selectively with the thymic production of certain suppressor T cells controlling self-reactive (autoimmune) T cells, allowing the latter to expand and cause autoimmune disease.

Animals↗
PubMed1988

B lymphocyte lineage-restricted expression of mb-1, a gene with CD3-like structural properties.

A gene, called m-mb-1, was isolated from a murine pre-B-minus T lymphocyte subtracted library. It was found expressed as mRNA at low to medium abundance in early progenitors of the B lineage, in pre-B and mature B lineage cell lines, in normal resting B lymphocytes and in polyclonally activated B cell blasts. The gene was not expressed in plasmacytomas, in cell lines of the monocyte/macrophage, the T lymphocyte or the fibroblast lineages, nor in thymus, liver, heart, kidney, lung or brain. The nucleotide sequence of the m-mb-1 gene encodes a putative membrane glycoprotein with 220 amino acids, which includes a leader sequence, a putative extracellular domain with two potential N-glycosylation sites, a transmembrane portion and a putative intracellular domain. The partial sequence of a human homologue, h-mb-1, shows nearly 90% homology in nucleotide as well as amino acid sequences to the murine form of a stretch of the putative intracytoplasmic domain. Antibodies raised against a fusion protein of m-mb-1 with protein A, affinity purified for their m-mb-1 specificity, stained pre-B and mature B cell lines on their surface, but did not stain T cell lines and fibroblasts. Antibodies raised against a stretch of 20 amino acids of the putative intracellular domain with 90% homology between the mouse and human protein did not stain the surface of any cell lines tested.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acid Sequence↗
PubMed1988

Symptomatic accessory lobe of the liver associated with hyperthyroidism.

A case of symptomatic accessory lobe of the liver occurred in a 15-year-old Japanese girl with hyperthyroidism. The patient presented with acute abdominal distress; at operation, a twisted necrotic mass of the accessory lobe of the liver was found. A review of the literature failed to show a previously reported instance in a child.

Adolescent↗
PubMed1987

Organization of the murine Ig-related lambda 5 gene transcribed selectively in pre-B lymphocytes.

lambda 5 is an immunoglobulin lambda light chain-related gene which is selectively transcribed in murine pre-B lymphocytes to yield a 1.2 kb poly(A)+ mRNA. Comparison of the nucleotide sequence of a 1 kb cDNA clone with the sequence of a genomic clone isolated from 70Z/3 murine pre-B lymphoma cells shows lambda 5 is composed of three exons spanning a 3.75 kb DNA segment. Conserved splice signal sequences at all exon/intron boundaries and the presence of a long open reading frame indicate that a functional mRNA molecule can be made. Exon I contains a cap-site and a potential ATG start codon as well as sequences encoding a signal peptide. This gene could encode a lambda 5 protein of 209 amino acids which has, however, not yet been identified. The 3' portion of exon II and all of exon III shows strong sequence homologies to J lambda L and C lambda L exons. Homology to the lambda L chain genes is lost in the 5' portion of exon II and throughout exon I. In exon I short homologies to leader sequences and to VH framework 1 sequences are seen.

Amino Acid Sequence↗
PubMed1987

Localization of the murine lambda 5 gene on chromosome 16.

The chromosomal location of the murine lambda 5 gene was analyzed by Southern hybridization using restriction enzyme-digested DNA from a panel of 15 mouse X hamster somatic cell hybrids. Sequences homologous with those of lambda 5 DNA were detected in DNA of 5 hybrids. In all 5 hybrids lambda 5 was contained in restriction fragments of equal sizes, the lengths of which indicated that the germline configuration of lambda 5 with three exons and the restriction sites expected from its genomic structure were present. Southern hybridization with the murine lambda 1 gene as a probe detected the same 5 hybrids as positive. The only mouse chromosome present on all of the positive hybrids, and absent from negative ones, was number 16. We conclude that lambda 5 is situated on the same chromosome as lambda 1, i.e., on the murine chromosome 16.

Animals↗
PubMed1986

Isolation of a cDNA copy of an RNA species expressed in murine pre-B cells.

A part of a gene, pZ 183, was isolated from a cDNA library constructed from poly(A)-containing RNA of the chemically induced murine pre-B lymphoma 70Z/3. This DNA sequence was found to be present in one of 5,000 cDNA clones in the unsubtracted library, and in one of 350 cDNA clones in a library in which sequences common to 70Z/3 and to a T cell hybridoma had been subtracted. This indicates that the corresponding gene belongs to the genes which are expressed with low to medium abundance in the pre-B cell line 70Z/3. The gene was found to be expressed in pre-B lymphomas, but not in B lymphomas, myelomas, T cell lymphomas, macrophage tumors or a fibroblast line. By in situ hybridization it was detected in 2-4% of fetal liver cells between day 15 and 16 of gestation, and in 1% of adult bone marrow cells. It was not detected in thymus cells, nor in mature T cells, spleen, adult liver, kidney, heart, lung or brain. The size of the transcript found in all pre-B cell lymphomas is 1.2 kb in length. The pZ 183 DNA sequence would appear to be a useful B-lineage specific marker which identifies pre-B cells at various stages before the mature B cell.

Animals↗
PubMed1986

Rhabdomyosarcoma of the penis.

We report a case of rhabdomyosarcoma of the penis, which was treated with local excision and chemotherapy.

Combined Modality Therapy↗
PubMed1985

Physicochemical and functional properties of murine B cell-derived B cell growth factor II (WEHI-231-BCGF-II).

A murine B lymphoma cell line, WEHI-231, constitutively secreted a kind of B cell stimulatory factor (BSF) that induced proliferation and IgM secretion in splenic B cells as well as BCL1 cells. Growth- and differentiation-promoting activities were not separated by various kinds of chromatographies on the basis of the m.w., isoelectric point, or hydrophobicity, and the degree of both activities in crude supernatants, DEAE-Toyopearl, TSK-3,000SWG, Mono P, and Phenyl-5PW fractions increased in a dose-dependent manner with complete correlation. The partially purified factor (WEHI-231-BGDF) did not show any other activities, such as IL 1, IL 2, interferon, or colony stimulating factor. WEHI-231-BGDF induced proliferation and IgM secretion in activated B cells with low density, but not in small resting B cells. WEHI-231-BGDF showed synergistic effect with dextran sulfate but not with anti-Ig in the induction of proliferation or IgM secretion in small resting B cells. WEHI-231-BGDF did not show any effect on Xid B cells. The relationship with several T cell-derived BSF and the significance of B cell-derived BSF in the B cell responses are discussed.

Animals↗
PubMed1984

Immunoglobulin gene expression and DNA methylation in murine pre-B cell lines.

DNA modification accompanying immunoglobulin gene expression was examined in various Abelson murine leukemia virus (A-MuLV)-transformed cell lines, which were able to differentiate from the mu- to mu+ stage or to undergo an isotype switch during in vitro culture. The C mu genes were relatively demethylated in the A-MuLV-transformed cell lines examined irrespective of whether or not the C mu genes were expressed. Normal IgM-bearing B cells, as well as a T cell line, also showed a similar DNA methylation pattern and the C mu genes were relatively demethylated. In one of the mu+ clones, however, the expressed C mu gene was heavily methylated. The DNA methylation pattern did not change and remained hypermethylated before and after gamma 2b expression in the two cell lines which underwent class switch to gamma 2b during in vitro culture, suggesting that expression of the gamma 2b gene was not accompanied by demethylation of the C gamma 2b gene. Taken together, these results indicate that DNA demethylation within and around the CH gene may not be necessary for its expression.

Animals↗
PubMed1983

B cell growth factors and B cell differentiation factor from human T hybridomas. Two distinct kinds of B cell growth factor and their synergism in B cell proliferation.

Human T hybridomas secreting B cell growth factors (BCGF) and B cell differentiation factor (BCDF) have been established. Hybrid clones 77-A, 94-C, and 98-F secreted BCGF that induced proliferation of anti-IgM-stimulated normal B cells. The culture supernatant from 77-A cells could also maintain continuous proliferation of colony-forming B cells, but the factor from 94-C could not. The addition of the supernatant from 94-C cells to that from 77-A cells, however, synergistically augmented the proliferation of colony-forming B cells, demonstrating the existence of two distinct kinds of BCGF and the synergism between them. These supernatants, however, showed no interleukin 2 (IL-2) or BCDF activity. A hybrid clone, 90-E, secreted BCDF. The culture supernatant induced Ig production in Cowan I-stimulated normal B cells or in a transformed B cell line, CESS. However, the supernatant had no BCGF or IL-2 activity. Anti-Ig-stimulated B cells, but not IL-2-dependent T cells, absorbed BCGF activity and CESS cells absorbed BCDF activity but not BCGF activity in the culture supernatants from T hybridomas. Taken collectively, the results demonstrated that IL-2, BCGF, and BCDF were different molecules and acceptors specific for the each molecule are present on the each target cell.

Absorption↗
PubMed1982

Induction of 19S IgM secretion in a murine pre-B cell line, 70Z/3, by cell hybridization with non-secreting myeloma cells.

Somatic cell hybrids were prepared between the TK-deficient variant of murine pre-B cell line, 70Z/3, cells and the HGPRT-deficient variant of non-secreting myeloma cells. Several hybrid clones which secreted IgM but did not express surface IgM were isolated. LPS stimulation did not induce the expression of surface IgM. SDS-PAGE analysis indicated that the IgM secreted by one of the hybrid clones was a 19S pentamer and that the size of its mu-chains was the same as that of mu-chains from MOPC 104E myeloma IgM. Two-dimensional gel electrophoresis of biosynthetically labeled immunoglobulin showed that the same pattern was obtained with kappa-chains from two hybrid clones and from the LPS-induced 70Z/3 cells. The result showed that cell hybridization could induce L-chain synthesis in the pre-B cell line. Anti-idiotypic antibody against the secreted IgM was prepared and it was shown that the surface IgM expressed on all LPS-stimulated 70Z/3 cells bore the same idiotype. Those results indicated that the specificity commitment has already occurred in 70Z/3 cells.

Animals↗