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Biomedical subjects

S Migita

Publications and source records attributed to S Migita.

At least 19 recordsLinked to original sources

Soybean protein isolate and soybean lectin inhibit iron absorption in rats.

Inhibitory effects of soybean protein isolate (SPI) and soybean lectin on the intestinal absorption of nonheme iron were investigated by in vivo studies in rats. Rats fed the SPI-based diet absorbed significantly less iron than did control rats fed the casein-based diet. Supplementing the SPI diets with 8% D-galactose significantly increased the incorporation of iron into liver ferritin, although D-galactose did not significantly increase iron absorption. Heat treatment of SPI significantly increased iron absorption. Ascorbate did not enhance iron absorption in rats fed the SPI-based diet. The presence of lectin in an aqueous extract of SPI was suggested by hemagglutination activity as well as by immunoreactivity with soybean lectin antibody. Soybean lectin introduced into ligated segments of the upper small intestine of rats inhibited ferrous iron absorption. This inhibitory effect, especially in the mucosal uptake, was significantly improved by addition of N-acetyl-D-galactosamine to soybean lectin. Soybean lectin had no effect on ferric iron absorption. Our results suggest that a portion of the reduction in iron absorption in rats fed SPI may be due to lectins.

Animals

c-myc gene in a murine plasmocytoma without visible chromosomal translocations moves to chromosome 12F1 with Pvt-1 and rearranges with IgH enhancer-S mu sequences.

The DCPC 21 plasmocytoma lacks any of the MPC-associated chromosomal translocations. However, the c-myc gene has been transposed to the IgH locus on chromosome 12 by an Ig switch-region-mediated recombination mechanism. DNA sequencing analysis, further, revealed that this recombination is consistent with an insertion of the IgH enhancer (E mu)-S mu sequences, 2341 bp in length, into the c-myc 5'-flanking region, resulting in 5': c-myc 5'-flanking-E mu-S mu-c-myc 5'-flanking-c-myc exon-1: 3' segment. In situ molecular hybridization of DCPC 21 metaphase chromosome spreads using a Pvt-1 probe demonstrated that Pvt-1 has also moved to the F1 sub-band region of chromosome 12 where the IgH genes are located. These results indicate that the c-myc gene has been inserted into the IgH locus together with the Pvt-1, regardless of whether plasmocytoma has cytogenetically identifiable translocations. The possible interaction between c-myc activation and Pvt-1 in the development of MPCs is discussed.

Animals

[Immunochemical analysis of two peak M proteinemia derived from structural differences of IgG Fc region].

We found M-proteins with two peaks by agarose electrophoresis in the serum of a myeloma patient. The M-proteins were identified as both IgG 1-kappa type, and classified as IgG-F (fast mobility) and IgG-S (slow mobility). 1) The possibility that the two M-proteins were derived from the post translational differences of sugar moieties of the same IgG molecule was unlikely, because no migration changes were observed in IgG-F and IgG-S after the treatment with 4 different sugar enzymes. 2) Fab fractions of IgG-F and IgG-S were analyzed. After papain or pepsin digestion, western blotting with anti-Fab antiserum revealed that the Fab fraction of IgG-F and IgG-S had identical mobility by agarose electrophoresis. However the Fc fractions of IgG-F and IgG-S analyzed by the same procedures with anti-Fe antiserum, were different. 3) Anti-idiotype antiserum prepared in rabbits against IgG-S, or -F, and absorbed by normal IgG and normal human serum showed a fused precipitin line with IgG-F and IgG-S. These findings suggest that two M-proteins with both IgG 1 and kappa type, have the same VH and VL regions but have different constant regions of heavy chain. Since one copy of IgG 1 constant gene is found in each human haploid gene. It is speculated that the switching of the rearranged VDJ gene to constant region gene occurred not only between cis chromosome but also between trans chromosome.

Aged

Functional character and augmentation of lymphocytes in regional lymph nodes of patients with lung cancer.

It appears that lymph node metastases are more frequent in lung cancer than in other cancers because of impaired defensive mechanisms in the regional lymph nodes. However, little is known about the immunologic function of regional lymph node lymphocytes (RLNL) in patients with lung cancer. We have studied the immunologic properties of RLNL in comparison with peripheral blood lymphocytes (PBL). We measured the natural killer (NK) cell activity of RLNL and PBL in patients with lung cancer and found that the NK activity was significantly more depressed in the RLNL than in the PBL. In contrast, interleukin-2 (IL-2) production was markedly higher in the RLNL than in the PBL. The cytotoxic effect of RLNL in nonmetastatic lymph nodes on target cells (such as K562 cells) or PC-3 and PC-10 cells (NK-resistant, human lung cancer of adenocarcinoma and epidermoid carcinoma, respectively) was significantly enhanced by in vitro incubation with recombinant IL-2 (rIL-2). Furthermore, we clarified that both rIL-2 and OK-432, which is a biologic response modifier and IL-2 inducer as well, augmented the cytotoxicity of RLNL and that these effector cells were lymphokine-activated killer (LAK) cells. The depletion of lymphocyte subsets by pretreatment with specific monoclonal antibody showed that the LAK activity in RLNL was mediated by CD3+ and CD8+ cells, whereas the lymphocyte subsets contributing the LAK activity in PBL were CD3+ and CD16+ cells. It was concluded that a majority of the effector cells in RLNL were LAK cells of the cytotoxic T cell population.

Adult

Interference of immunoglobulins in the radioimmunoassay of human beta-endorphin.

The interference of immunoglobulins in the radioimmunoassay (RIA) of human beta-endorphin was investigated. Human IgM showed no cross-reactivity. Human IgA showed a weak cross-reaction, but the dilution curve of IgA did not show parallelism with the standard curve of beta-endorphin, thus indicating its antigenic difference. The dilution curves of human IgG showed 0.18% displacement with respect to the human beta-endorphin standard curve, with good parallelism. Moreover, five patients with multiple myeloma of the IgG type showed falsely elevated beta-endorphin levels. We investigated the possibility that certain IgGs may be responsible for the displacement of [125I]beta-endorphin in the beta-endorphin kit. The apparent beta-endorphin level of plasma from multiple myeloma patients was markedly decreased after affinity chromatography of the serum on protein A-Sepharose. In another 3 patients with multiple myeloma, we examined IgG interference by measuring the beta-endorphin levels in their lyophilized IgG diluted with saline. The results demonstrated high values of 20.2, 25.5 and 21.2 pmol/l respectively, also showing good parallelism. These immunological parallels to human beta-endorphin verify that a part of the amino acid sequence of human IgG is similar to that of human beta-endorphin. Consequently, in the measurement of beta-endorphin with polyclonal antibody, the results may sometimes be spuriously high due to cross-reaction with IgG, e.g., in patients with IgG myeloma. To avoid IgG interference, a specific monoclonal antibody to synthetic beta-endorphin should be used rather than polyclonal antibodies.

Blood Chemical Analysis

Isolation of two new proteins from bovine colostrum which stimulate epidermal growth factor-dependent colony formation of NRK-49F cells.

Defatted bovine colostrum and decaseinated whey contain biological activity similar to that of TGF-beta in that they stimulate the anchorage-independent growth of NRK-49F cells in the presence of EGF. Two new proteins with such activity, termed BC-1 and BC-2, were isolated from decaseinated colostrum by a sequence of DEAE-Sephacel chromatography, Sephadex G-100 gel filtration in 1 M acetic acid, Sephadex G-50 re-gelfiltration in 8 M urea-1 M acetic acid and reverse-phase FPLCs. The two proteins showed distinctly different molecular weight from that of TGF-beta 1. BC-1 was a small Mr peptide of 8.5 kD. BC-2 had molecular mass of 46 kD, which yielded peptides of 46,40, and 6 kD on reduction. In contrast to TGF-beta, both proteins did not lose their biological activity on reduction. Both BC-1 and BC-2 suppress DNA synthesis in concanavalin A-stimulated thymocytes. These results suggest that BC-1 and BC-2 belong to a new class of mitogen/inhibitors, though their biological activities resemble those of TGF-beta.

Animals

[Biosynthesis and significance of acute phase proteins].

Acute phase proteins (APP) increase by the chemical receptors of macrophage via stimulations of either Fc or complement or other chemical receptors. No differences of APP pattern were observed by the different stimulants, because the effects of stimulation are changed by many processing steps in the macrophage as well as in the liver cell thereafter. Whether the APP increase results in good prognosis for original sickness or not are examined by multiple regression analysis in 38 cases of maxillary and 51 cases of laryngeal cancer with the observation for over five years. Alpha 1X contributes positively with length of their life, whereas alpha 1AG and ceruloplasmin contribute negatively. We could say that not all components of APP increase are advantageous for the diseases.

Acute-Phase Proteins

Serum amyloid P component regulation by sex steroids in rats.

Serum amyloid P component (SAP) has been designated as a female protein in hamsters. To investigate the effects of sex steroids on SAP concentration in rats, SAP was purified from Wistar rats by affinity chromatography. Anti-SAP was raised. Sample sera were obtained from 150 young and old rats, after which, they were injected with either estradiol (E2), testosterone (T), or dehydroepiandrosterone (DHA). Sera were serially obtained from the tail vessels until the 8th day after injection. Serum levels of SAP were measured by micro single radial immuno-diffusion with a standard pooled serum as 100%. As the rats aged, the SAP levels in untreated female rats increase with age from 93% at 11 weeks to 346% at 58 weeks. In 28-week-old rats, the SAP levels in females (135 +/- 40%) were significantly (p less than 0.01) higher than those in males (80 +/- 32%). When old female rats (56 wk) were injected with DHA (3.5 mg), the SAP decreased significantly (p less than 0.01) to 70.8% of the preinjection level on the 8th day after injection. When young male rats (11 wk) were jnjected with E2 (0.5 mg), the SAP levels increased rapidly to 188% of the prelevel on the 5th day. Serum E2 levels reached a peak on the 2nd day. After the injection of T, the SAP levels did not change.

Animals

Chromosomal assignment of woodchuck hepatitis virus (WHV) DNA integration sites in a woodchuck hepatocellular carcinoma-derived cell line (WH257GE10).

The chromosomal sites of woodchuck hepatitis virus (WHV) DNA integration were identified in a woodchuck hepatocellular carcinoma-derived cell line (WH257GE10) by the in situ hybridization technique using 3H-labelled WHV whole genome (WHV 2) as a probe. The G-banded chromosome spreads from WH257GE10 were identified and diagrammed schematically according to their band patterns. WHV DNA was integrated into 2 sites: 33 region of the long arm of chromosome 6 (6q33) and 31 region of the long arm of chromosome 8 (8q31). Chromosomal sites of WHV DNA integration were stable during successive passage periods analyzed in vitro.

Animals

The H-2 class II genes and the susceptibility to the development of pulmonary adenoma in mice.

To determine the locus in the H-2 complex that affects susceptibility to the development of pulmonary adenomas in mice, H-2 congenic and recombinant strains of mice with A/Wy, BALB/c, C3H, and B10 backgrounds were subjected to treatment with urethane. The average number and the incidence of adenoma foci were recorded five months after the treatment. In H-2 congenic strains on the A/Wy background, the average number of adenoma foci per mouse was significantly higher in mice of the A/Wy, A/J, and A-Tlab (H-2a) strains than in A.BY (H-2b) mice. In BALB/c and C3H congenic strains, the strains carrying the H-2k haplotype were more susceptible than those carrying the H-2b haplotype. In H-2 congenic strains on the B10 background, the average number and incidence of foci was also higher in haplotypes a, h2, k, and j than in haplotypes b, s, f, d, r, h4, i3, i5, and t4. The average numbers of adenoma foci in (A/J X A.BY)F1 (H-2a/H-2b) and (B10 X B10.A)F1 (H-2b/H-2a) were intermediate between the numbers in the parental strains. In [B10.A(4R) X B10.A (3R)]F1 (H-2h4/H-2i3) and [B10.A(4R) X B10.A(5R)]F1 (H-2h4/H-2i5), the numbers of adenoma foci were higher than in resistant parental recombinants. These patterns of response to urethane matched the patterns of the immune response to lactate dehydrogenase-B (LDH-B) and immunoglobulin gamma 2a (IgG2a) proteins. These differences between mice in their susceptibility to the development of pulmonary adenomas is probably due to the polymorphism of the class II genes in the H-2 complex.

Adenoma

C-myc-S mu rearrangement in a murine plasmacytoma without visible chromosomal translocations.

We report here that one murine plasmacytoma (DCPC 21) arising in a Balb/c mouse implanted i.p. with a Millipore diffusion chamber lacks any known chromosomal translocations. In situ molecular hybridization analysis of the metaphase spreads of DCPC 21, however, revealed that the c-myc gene has moved to the IgH locus on the chromosome 12. Further, an Ig switch region-mediated recombination was detected. The DNA sequencing analysis demonstrated that the c-myc gene has juxtaposed directly to S mu 5'-flanking sequence in a 'head-to-tail' orientation. The results strongly support our notion that the c-myc rearrangement is an essential step in the genesis of murine plasmacytomas, whether or not they have visible chromosomal translocations.

Animals

The role of fibronectin in the development of experimental amyloidosis. Evidence of immunohistochemical codistribution and binding property with serum amyloid protein A.

Azocasein-induced amyloid A (AA) amyloidosis in CBA/K1Jms mice was investigated to elucidate a preference of serum amyloid A (SAA) deposition in the spleen. By indirect immunofluorescence using anti-SAA/AA antibodies the initial deposition of SAA/AA was recognized in the marginal zone of spleen at 20 days after azocasein injection. Indirect immunofluorescence using anti-fibronectin antibodies also showed meshwork positivity in the corresponding area more intensely than that in controls. Immunoelectron microscopy using anti-SAA/AA revealed the presence of positively stained flocculent materials on cell surfaces of macrophages in the marginal area in addition to amyloid fibril. The tissue fibronectin rapidly increased in the spleen and maintained 10 times more than that of controls until the 20th day. Binding assay of SAA on frozen sections revealed the presence of SAA-binding substances in the perifollicular area. Affinity chromatographic assay showed fibronectin have a binding capacity to SAA1 and SAA2. By binding assay on the microtiter plate, SAA had more affinity to fibronectin than those of heparan sulfate, collagen type I, or serum amyloid P component. These results indicate that fibronectin plays an important role in the development of amyloidosis by working as a linking protein between SAA and the cell surface of macrophages.

Amyloidosis

An atypical t(12;15) translocation of chromosomes found in murine plasmacytomas and activation of the c-myc oncogene.

Cells from murine plasmacytomas (MPC) consistently exhibit either the 12;15 or the 6;15 translocation. Recently, we found that cells from 2 MPC (ABPC 45 and ABPC 26) did not exhibit any known translocation. However, these MPC contained one chromosome 15 (15q-) that was shorter than its normal homologue and one 12 (12q+) that was longer than its normal 12 counterpart. Chromosome 15q- contained only one thin D band, corresponding in size to either D1 or D3 band. A minor light band D2 was apparently deleted. Chromosome 12q+ contained a light F1 band that was longer than the normal 12F1. In ABPC 45, the c-myc gene was assigned by in situ hybridization to the F1 region of 12q+ as well as to its original site of 15D2. Moreover, the in situ hybridization experiment assigned the S alpha gene to the F1 regions of both chromosomes 12 and 12q+. These findings indicate that a minor light band D2 of chromosome 15 carrying the c-myc gene was translocated into the major light band F1 of 12, resulting in a longer chromosome 12q+ and a correspondingly shorter chromosome 15q-. This type of chromosomal translocation suggests that ABPC 45 developed through a cytogenetic mechanism different from that of MPC with the typical t(12;15) translocation.

Animals

Hereditary C3 hypocomplementemia in the rabbit.

Hereditary hypocomplementemia of the third component of complement (C3) was found in a strain of rabbits in which hereditary C8 alpha-gamma deficiency was also found. The serum C3 concentration, haemolytic C3 activity and total complement haemolytic activity (CH50) of these animals were, respectively, 6-12%, 8-13% and 27-37% of the normal levels. The haemolytic complement activity in the C3 hypocomplementemic (C3-hypo) rabbit serum was restored in a dose-dependent manner by the addition of purified rabbit C3. The levels of factor H and properdin and components C2 and C6 were in the normal range, and the levels of factors B and D and component C8 were higher than normal. The low level of serum C3 in C3-hypo rabbits was not due to C3 conversion, partial C3 antigenicity, presence of a C3 inhibitor or hypercatabolism of normal C3. Furthermore, no change in the ratio of C3 protein levels was observed between C3-hypo and normal rabbits, even after turpentine injection. In addition, the C8 alpha-gamma deficiency condition does not affect C3 activity and C3 catabolism in vivo. Mating tests showed that the C3 hypocomplementemia is transmitted as a simple autosomal co-dominant trait. C3-hypo rabbits have a lower survival at 3 months than normal rabbits. C3-hypo rabbit serum also has a lower bactericidal activity than normal rabbit serum. The PAGE under reducing conditions showed no difference in the molecular weights of C3 alpha and C3 beta chains between C3-hypo, heterozygous and normal animals.

Aging

Analysis of the chromosomal abnormalities of a woodchuck hepatocellular carcinoma-derived cell line (WH257GE10).

The normal woodchuck karyotype was determined by the G-banding technique, and the chromosomal abnormalities of a woodchuck hepatocellular carcinoma-derived cell line (WH257GE10) were analyzed and compared with it. The normal woodchuck karyotype was 38,XY in a male, and 38,XX in a female. Autosomes were classified into 2 groups (A and B). Group A consisted of 13 pairs (1-13) of metacentric or sub-metacentric chromosomes, and group B consisted of 5 pairs (14-18) of telocentric or sub-telocentric ones. The X chromosome was sub-metacentric, and the Y chromosome was telocentric. In WH257GE10, the modal number was 36. Deletion of one of the chromosome 5 pair, of the chromosome 13 pair, and of the Y chromosome was observed. Two marker chromosomes (M1 and M2) were found. These markers showed the same G-banded patterns except for a small chromosome fragment at the distal part of the long arm of M1. The chromosome aberrations were very stable through successive passages in vitro. These findings suggest that the chromosomal abnormalities found in WH257GE10 might be associated with the pathogenesis of woodchuck hepatocellular carcinoma.

Animals