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Biomedical subjects

K Miyazawa

Publications and source records attributed to K Miyazawa.

At least 217 records · Page 12Linked to original sources
PubMed1991

Synergistic effect of human lactoferrin and recombinant murine interferon-gamma on disease progression in mice infected with the polycythemia-inducing strain of the Friend virus complex.

Mice infected with the polycythemia-inducing strain of the Friend virus complex (FVC-P) have been used as a leukemic mouse model. In the present study, purified iron-saturated human lactoferrin (LF) and recombinant murine (rmu) interferon-gamma (IFN-gamma), alone or in combination, were used to influence disease progression in virally infected mice. DBA/2 mice were injected i.v. with FVC-P, and were treated s.c. with 100 micrograms LF at day 7, and/or rmuIFN-gamma at 5 x 10(4) units/day for 3 days beginning at day 6 after viral infection. Mice were assessed for survival, and also 14 days after virus inoculation, the mice were killed and spleen extracts were assessed for spleen focus forming virus (SFFV) titers by spleen focus forming unit (SFFU) assay, SFFV mRNA and genomic DNA expression, and natural killer (NK) cell activity. Treatment with LF or rmuIFN-gamma alone had little or no effect on SFFU numbers or SFFV mRNA or genomic DNA expression. However, dramatically decreased SFFV titers and levels of SFFV mRNA and genomic DNA were observed in mice treated with the combination of LF and rmuIFN-gamma. NK cell activity decreased by FVC-P was returned to normal levels by LF and rmuIFN-gamma. The combined treatment also enhanced the survival rates of FVC-P-infected mice. The results suggest synergistic suppressive effects of LF with rmuIFN-gamma on disease progression in FVC-P-infected mice. This information might be of significance as a potential therapy for patients with leukemia and those infected with retroviruses.

Animals↗
PubMed1991

Mast cell growth factor (c-kit ligand) enhances cytokine stimulation of proliferation of the human factor-dependent cell line, M07e.

Murine mast cell growth factor (muMGF), a c-kit ligand, has additive to greater-than-additive effects on in vitro colony formation of murine and human myeloid progenitor cells stimulated with erythropoietin, granulocyte-macrophage colony-stimulating factor (GM-CSF), and/or interleukin (IL)-3. To confirm direct-acting effects on responding cells, MGF was assessed alone and in combination with other cytokines for effects on the proliferation of the human factor-dependent cell line, M07e. Proliferation was assayed in liquid culture by [3H]thymidine uptake and in semisolid medium by colony formation. Purified recombinant (r) muMGF (25-50 ng/ml) by itself had proliferative activity but less than r human (hu) GM-CSF. In combination with rhuGM-CSF (250 U/ml) or IL-3 (500 U/ml), rmuMGF (25 ng/ml) enhanced [3H]thymidine uptake two- to sevenfold greater than the sum of the effects of each factor alone. Similar enhancement was seen in the number and size of colonies formed. When MGF was used in combination with rhuIL-4 (500-1000 U/ml), rhuIL-6 (5 ng/ml), rhuIL-9 (5-10 U/ml), or rhu interferon gamma (IFN-gamma; 250-500 U/ml) (factors that alone stimulate little proliferation), [3H]thymidine uptake and colony formation were respectively increased 2- to 11- and 3- to 55-fold over the sum of each of the effects of the factors alone. Exposure of 5 x 10(5) cells/ml to 50 ng/ml MGF for 24 h, a time during which synergism is noted with MGF plus either GM-CSF or IL-3, did not change GM-CSF or IL-3 receptor binding affinity or the number of binding sites. Exposure of cells to MGF for 48 h did not alter subsequent GM-CSF- or IL-3-stimulated proliferation. The results suggest that M07e cells will be useful as a model for the analysis of intracellular biochemical mechanisms of the direct-acting proliferative and synergistic effects of MGF.

Animals↗
PubMed1991

Comparative analysis of signaling pathways between mast cell growth factor (c-kit ligand) and granulocyte-macrophage colony-stimulating factor in a human factor-dependent myeloid cell line involves phosphorylation of Raf-1, GTPase-activating protein and mitogen-activated protein kinase.

Mast cell growth factor (MGF, the ligand for c-kit receptor) can stimulate proliferation of factor dependent myeloid cell line, M07e, and MGF synergizes with granulocyte-macrophage colony-stimulating factor (GM-CSF) or IL-3 in this effect. The effect of MGF on protein tyrosine kinase activity in M07e cells was investigated by immunoblotting with anti-phosphotyrosine mAb and this was compared with effects of GM-CSF. MGF stimulation rapidly induced or enhanced at least 12 tyrosine phosphorylated bands. Major bands had molecular weights of 145, 120, 110, 98, 62, 55 and 42 kD. P145, the most prominent phosphorylated protein, was identified as c-kit product using anti-c-kit-mAb (YB5.B8), suggesting ligand-dependent receptor autophosphorylation. Five of six tyrosine phosphorylated bands induced or enhanced by GM-CSF stimulation comigrated with those tyrosine phosphorylated by MGF (138, 120, 76, 55 and 42 kD). P42 was identified, at least in part, as mitogen-activated protein (MAP) kinase. MGF induced tyrosine phosphorylation of a complex of GTPase-activating protein (GAP, 120 kD) and GAP associated proteins (p62/p190) as detected by anti-GAP Ab immunoprecipitation followed by immunoblotting with anti-phosphotyrosine mAb. GM-CSF also stimulated slightly but consistently tyrosine phosphorylation of GAP and p190 but not p62. Both MGF and GM-CSF enhanced Raf-1 phosphorylation and increased Raf-1 associated kinase activity in vitro. Phosphoamino acid analysis revealed Raf-1 phosphorylation by these two growth factors occurred almost exclusively on serine residues. No tyrosine phosphorylation of Raf-1 protein was detected. These data suggest shared and unshared components of signaling pathways of both factors, which may be involved in cell proliferation.

Bone Marrow↗
PubMed1991

[A study of crystallization on urolithiasis in vitro].

The formation, growth and aggregation of calcium oxalate crystals were evaluated with a Coulter counter. CG-120 and sodium pentosan polysulfate (SPP) has inhibitory activity on calcium oxalate crystal formation, growth and aggregation in the seeded crystal system and whole urine system. In continuous crystallizer system, they inhibit the nucleation rate. A new system of observing the crystal formation and growth of fragmented stones after extracorporeal shock wave lithotripsy has been developed. CG-120 has an inhibitory effect on their growth. The deposition of calcium oxalate crystals in the rat kidney was induced, and the, the volume and number of crystals were estimated using a Coulter counter. SPP has an inhibitory effect on calcium oxalate crystal growth in vivo.

Animals↗
PubMed1991

The kit receptor and its ligand, steel factor, as regulators of hemopoiesis.

Mouse strains carrying mutations at the Dominant White Spotting (W) locus or the Steel (Sl) locus are anemic and display defects in pigmentation and gametogenesis. In W mutants the anemia is due to a deficiency of hemopoietic stem cells and, in Sl mutants, to a deficiency of supporting stromal cells in the bone marrow. The W locus encodes the c-kit proto-oncogene product, a cell surface receptor with protein-tyrosine kinase activity, and the Sl locus encodes its ligand, a hemopoietic cytokine known variously as Steel factor (SLF), mast cell growth factor, stem cell factor, and Kit ligand. SLF can synergize with a number of other cytokines to stimulate growth of hemopoietic progenitors in vitro and stimulates blood cell production in vivo in animals. Here we review the biological activities of SLF, with particular emphasis on its effects on hemopoietic stem and progenitor cells. We also discuss present knowledge of the molecules involved in SLF-triggered signal transduction, and speculate on potential therapeutic applications for SLF in human disease.

Anemia↗
PubMed1991

[Technique and problems of total parathyroidectomy with autotransplantation in secondary hyperparathyroidism].

Between 1982 and 1990, 20 patients with chronic renal failure underwent total para-thyroidectomies and autotransplantations as treatment for secondary hyperparathyroidism. Fourteen cases were cured of their symptoms and their serum PTH levels was restored to normal. Recurrent hyperparathyroidism developed in 6 cases. In 3 of the 6 cases, excision of parathyroid tissue from the forearm could easily be performed under local anesthesia. Of the other cases, 2 had five and one had six glands. Several localizing methods should be performed before operation, in order to overlook the parathyroid glands in different anatomic positions.

Adult↗
PubMed1991

[Aging effects on blood biochemical parameters in aged women: a longitudinal study using principal component analysis].

In order to examine the aging effects on blood biochemical parameters, 25 aged females (70 +/- 8 years old at the beginning of this investigation) were studied prospectively for 7 years. Biochemical parameters were measured in 1982, 1985, 1987, and 1989. Component scores were obtained by principal component analysis applied to all of these 100 data. The data of 13 biochemical parameters and 4 component scores were analyzed for aging, cohort, and time effects by utilizing 3 types of approach i.e., longitudinal, cross-sectional, and time-series. Positive aging effects were observed on blood urea nitrogen and 4th component score. Fourth component score had positive relations to blood urea nitrogen and total bilirubin, and a negative relation to total protein. This 4th component score increased with longitudinal age changes among all cohorts divided by decade, and it increased markedly over 70 years old. These results suggest that the aging effects on biochemical parameters are related with both the decrease in glomerular and hepatocellular functions and the increase in breakdown of tissue protein.

Aged↗
PubMed1991

[Real time microscopic image transmission system by using Hi-vision technique].

Using a high definition television (HDTV) technique, we have designed and developed the real time microscopic image transmission system. The department of laboratory and pathology, 500 m apart, are connected by this system on a light fiber line. It consists of an electrically controlled microscope, a HDTV camera, a HDTV color monitor, and a video transmitter on the laboratory side, while on the pathology a remote microscope controller, a video receiver, and a HDTV color monitor of 22.5 (H)-39.5(W) cm in CRT size. By monitoring real time noiseless picture, pathologists can select the objective lenses, move the stage, and adjust the focus of microscope at their own office. Three-month trial revealed that this prototype system was quite useful for prompt histo-pathological diagnosis during surgical operations. So far as we know, this microscopic image transmission system with Hi-vision TV is the first one in practical use in this field.

Microscopy↗
PubMed1990

Primary structure of rat hepatocyte growth factor and induction of its mRNA during liver regeneration following hepatic injury.

Overlapping cDNA clones for rat hepatocyte growth factor (rHGF) were isolated by cross-hybridization with the cloned cDNA for human hepatocyte growth factor (hHGF) and the nucleotide sequence of the cDNA was determined. The entire primary structure of rHGF was deduced from the sequence. Comparison of the amino acid sequences between rat and human HGFs revealed that the two sequences are highly conserved throughout the protein structures, suggesting that rat and human HGFs may be functionally similar. Responses of the rHGF mRNA during liver regeneration in rats were examined by Northern blot hybridization analysis with the aid of the cDNA probe for rHGF. The mRNA levels increased in the liver and spleen but not in the kidney after administration of carbon tetrachloride. At the maximum level of induction, the rHGF mRNA increased in the liver about 4.5-fold over its normal level. The mRNA levels also increased in the liver and spleen after administration of D-galactosamine. On the other hand, no obvious increase of the mRNA was observed in the liver and spleen after partial hepatectomy. These observations suggest that HGF may function as a regulator of liver regeneration following hepatic injury caused by hepatotoxins.

Amino Acid Sequence↗
PubMed1990

Isolation and characterization of a new hemagglutinin from the red alga Gracilaria bursa-pastoris.

A new agglutinin has been isolated from the red alga Gracilaria bursa-pastoris by affinity chromatography on a yeast mannan-Cellulofine column. This agglutinin was isolated as a monomeric glycoprotein with a relatively low molecular weight. It had an isoelectric point of 4.7 and contained large amounts of Gly, Asx and Glx. It agglutinated trypsin-treated rabbit erythrocytes at the low concentration of 30 ng/ml. The activity was inhibited only by glycoproteins bearing N-glycans. This agglutinin also showed mitogenic activity for mouse splenic lymphocytes.

Amino Acids↗
PubMed1990

Complement activation induced by human C-reactive protein in mildly acidic conditions.

Human C-reactive protein (CRP) is known to activate the C system upon reaction with phosphocholine-containing or polycation-containing ligands. We found that, even in the absence of these ligands, CRP caused C activation in mildly acidic conditions. The optimum pH for the activation was 6.3, which is within a physiologic range normally found at an inflammatory locus. In this activation, C components C1 and C4 were extensively consumed, C2 and C3 were moderately consumed, and C5 was only slightly consumed. These results indicate that the activation is mediated via the classical pathway, but is restricted to the early stage of the C cascade. As with the plasma contact system, the reaction proceeded in glass tubes but not in polypropylene tubes. However, even in polypropylene tubes, the reaction proceeded after the supplement of kaolin particles to the system. Probably the C activation induced by CRP at a mildly acidic pH required negatively charged surfaces. Analyses of circular dichroism and fluorescence spectra indicate that CRP undergoes a pH-dependent conformational change, thus affecting the reactivity of CRP with the C system.

C-Reactive Protein↗
PubMed1990

Tetrodotoxin and related substances in a ribbon worm Cephalothrix linearis (Nemertean).

A ribbon worm Cephalothrix linearis (Nemertean) showed a high toxicity, of up to 22,000 MU/g proboscis and 13,600 MU/g body, in terms of tetrodotoxin. This organism secreted the toxin from the skin when wiped with gauze. The toxin was partially purified from the secretion as well as the wiped body by ultrafiltration and Bio-Gel P-2 column chromatography. Thin-layer chromatographic, electrophoretic, high performance liquid chromatographic, and gas chromatography-mass spectrometric analyses showed that the secreted toxin was composed almost exclusively of a tetrodonic acidic-like substance, whereas the remaining toxin in the wiped body consisted of the said substance and tetrodotoxin.

Animals↗
PubMed1990

Is examination of fructosamine levels valuable as a diagnostic test for diabetes mellitus?

In order to develop a simple, one-point diagnostic test for diabetes mellitus in a mass population surveys, we measured levels of fructosamine (FRA), one of the glycated proteins. Seven hundred and thirty-eight people had their levels of fasting plasma glucose (FPG), FRA and hemoglobin A1c (HbA1c) examined before taking 75 g oral glucose tolerance tests (OGTT). The results of OGTT distinguished a diabetic group (DM) of 143 from a non-diabetic group (non-DM) of 595 subjects. Since there was a significant correlation between FRA levels and plasma glucose levels 2 h after OGTT (PG-2h), as well as between FPG and PG-2h, a discriminant analysis using FPG and FRA was carried out in order to separate the DM group from the non-DM group. According to this analysis, a positive f, where f = FPG-(mg/dl) + 12.0 FRA(mmol/l) - 150, would determine a subject to be a diabetic. However, the sensitivity of this analysis was only 0.521. It can be concluded that the sensitivity of a simple, one-point determination for diabetes mellitus using measured levels of FRA was insufficient, even by application of discriminant analysis, and that the OGTT is still needed for a diagnostic test for diabetes mellitus in mass population surveys.

Biomarkers↗
PubMed1990

Hepatosplenic schistosomiasis in pregnancy: report of a case and review of the literature.

We present a report of a pregnancy complicated by chronic schistosomiasis. A.H. is a 22 year old G1 Filipina, referred at 34 weeks gestational age for evaluation of hypersplenism and progressive thrombocytopenia. Physical exam was remarkable for hepatosplenomegaly. Laboratory evaluation of hepatic, renal, hematologic, autoimmune, or infectious disease etiology or abnormality was negative. Ultrasound revealed a normal fetus, an enlarged spleen, dilated splenic and hepatic vasculature and an enlarged liver with periportal fibrosis. Abdominal computed tomography revealed subcapsular calcifications, dilated ducts, and periportal fibrosis. Esophagogastrojejeunoscopy showed no varices. The presumptive diagnosis of hypersplenism secondary to chronic hepatosplenic schistosomiasis was made. Based on pathophysiology and literature review conservative management was elected. Liver functions, clotting functions, and platelet counts were monitored closely. Intense antepartum fetal monitoring was performed. Platelet counts remained between 30 and 40K. The patient went into labor at 38 3/7 weeks and delivered a 3148 g female Apgars 8/9 by spontaneous vaginal delivery. Evaluation of the placenta was negative for ova. By 2 weeks postpartum platelet counts had increased to the 60-70 k range, and a rectal biopsy, positive for S. japonicum ova was performed. Treatment with three doses of Praziquantel 20 mg/kg q8h was completed prior to her return to the Philippines.

Adult↗
PubMed1990

Fetal pancreas transplantation in miniature swine. IV. Suppression of DTH and MLR responses by treatment with ultraviolet light-irradiated peripheral blood lymphocytes.

Irradiation of peripheral blood lymphocytes of miniature swine with ultraviolet light prevented them from initiating proliferative responses in allogeneic mixed lymphocyte reactions and also reduced IL-2 production in these MLRs. When pigs were injected in a series of 4-5 weekly transfusions with UV-irradiated allogeneic PBL differing at the MHC, PBL of recipient pigs progressively responded less strongly to donor PBL in MLRs over the treatment period. These pigs also gave negligible delayed-type hypersensitivity responses to donor PBL at the end of the treatment period. Of the seven UV-irradiated PBL-treated pigs, four produced no antidonor PBL antibody and three produced antibody. Serum from the three antibody-producing pigs also suppressed MLRs of unrelated PBL. By contrast, pigs that received a series of injections of untreated allogeneic PBL gave strong DTH responses to donor PBL and heightened proliferation in MLRs with donor PBL, and all produced antidonor PBL antibody.

Animals↗