Search PubMed⌕ Search

Biomedical subjects

S Miyajima

Publications and source records attributed to S Miyajima.

At least 37 records · Page 2Linked to original sources
PubMed1998

Lecithin-bound superoxide dismutase in the prevention of neutrophil-induced damage of corneal tissue.

PURPOSE: To evaluate the effects of a lipophilic analog of superoxide dismutase (SOD) in the prevention of polymorphonuclear leukocyte (PMN)-induced damage to corneal epithelial cells in vitro and in bacterial corneal ulcers in vivo. METHODS: Immortalized human corneal epithelial cells (T-HCEC) were cocultured with human PMNs activated with N-formyl-methionyl-leucyl-phenylalanine for 18 hours, after which lactate dehydrogenase (LDH) activity of the supernatant was measured as a marker of cellular damage. The inhibitory effects of lecithin-bound SOD (PC-SOD) and unmodified SOD, as well as PMNs pretreated with anti-CD 18 monoclonal antibody, were compared with untreated control. The retention of each drug on the ocular surface of healthy volunteers was measured by flow cytometry using brush cytology samples. The protective effects of a 0.1% solution of PC-SOD on Pseudomonas aeruginosa corneal infection in guinea pigs were assessed by inflammatory grading scores and histology. RESULTS: Both PC-SOD and SOD effectively suppressed PMN-induced LDH release in T-HCEC in a dose-dependent manner. LDH release was also attenuated when PMNs were pretreated with anti-CD 18 antibodies, suggesting that adhesion molecules were involved in the process. Brush cytology of conjunctival samples showed that PC-SOD was retained longer on the ocular surface compared with unmodified SOD. PC-SOD significantly prevented excessive tissue damage by infiltrating PMNs in P. aeruginosa corneal infection, whereas in control eyes, perforation of the cornea occurred by 6 days. CONCLUSIONS: PC-SOD was effective in attenuating PMN-related tissue damage to corneal tissue both in vitro and in P. aeruginosa infection in guinea pigs.

Animals↗
PubMed1998

Treatment of Fetal Premature Ventricular Contractions by Administering Propranolol Hydrochloride Orally to the Mother.

> Frequent fetal premature ventricular contractions were diagnosed at 39 weeks of gestation. To avoid unnecessary cesarean section, the mother was administered propranolol hydrochloride orally. The tococardiography became feasible and permitted us to evaluate fetal well-being. The patient successfully delivered transvaginally a male infant at 40 weeks of gestation.

Journal Article↗
PubMed1997

Activation of human neutrophil procollagenase by nitrogen dioxide and peroxynitrite: a novel mechanism for procollagenase activation involving nitric oxide.

The involvement of nitric oxide (NO) and its reactive intermediates such as nitrogen dioxide (NO2) and peroxynitrite (ONOO-) in the activation of matrix metallo-proteinase was investigated. The human neutrophil procollagenase (matrix metalloproteinase-8) (M(r), 85 kDa) was purified to homogeneity from human neutrophils by using column chromatography. After incubation of human neutrophil procollagenase with various nitrogen oxide-generating systems, collagenolytic activity in each reaction system was measured. In addition, neutrophil collagenase activity was determined by assessment of proteolysis of human alpha 1-protease inhibitor. NO was formed by the propylamine NONOate, and NO2 was generated by oxidation of NO with 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl 3-oxide (carboxy-PTIO). NO2, formed by NONOate and carboxy-PTIO, and the synthetic ONOO- exhibited strong activation of the procollagenase at 1-20 microM. Significant activation of the procollagenase was observed with use of authentic NO2 gas as well. Constant flux infusion of ONOO- into the procollagenase solution resulted in stronger procollagenase activation than did a bolus addition of ONOO- to the reaction mixture. However, NO showed only weak activating potential under the aerobic (ambient) condition; an NO concentration of more than 10 mM was needed for appreciable activation of the procollagenase. Of considerable importance was the fact that NO participates in activation of the neutrophil collagenase through its conversion to NO2 or ONOO- in human neutrophils. These results suggest that NO2 and ONOO- may be potent activators of human neutrophil procollagenase.

Benzoates↗
PubMed1997

Lead-induced alteration of heparan sulfate proteoglycans in cultured vascular endothelial cells.

We investigated the alterations of heparan sulfate proteoglycans produced by vascular endothelial cells after exposure to lead. Bovine aortic endothelial cells were cultured and metabolically labeled with [3H]glucosamine and [35S]sulfate in the presence of lead chloride at 10 microM. Radiolabeled HSPGs were separated by ion-exchange chromatography and either their hydrodynamic size or the length of heparan sulfate chains were characterized by gel filtration. It was found that lead markedly suppresses the incorporation of the radioactive precursors into HSPGs in the cell layer; the incorporation into chondroitin/dermatan sulfate proteoglycans was decreased by the metal only slightly. The suppression by lead occurred in the low molecular weight subclass of HSPGs rather than the high molecular weight subclass. However, the length of heparan sulfate chains was not changed by the metal. A sodium dodecyl sulfate-polyacrylamide gel electrophoresis of [35S]methionine-labeled proteoglycans after heparitinase digestion showed that there were slightly more HSPG core proteins without a change of the size in lead-treated cell layer. It was, therefore, suggested that vascular endothelial cell layer after exposure to lead has more HSPG core proteins with fewer heparan sulfate chains without a change in length.

Animals↗
PubMed1997

Activation of human matrix metalloproteinases by various bacterial proteinases.

Matrix metalloproteinases (MMPs) are zinc-containing proteinases that participate in tissue remodeling under physiological and pathological conditions. To test the involvement of bacterial proteinases in tissue injury during bacterial infections, we investigated the activation potential of various bacterial proteinases against precursors of MMPs (proMMPs) purified from human neutrophils (proMMP-8 and -9) and from human fibrosarcoma cells (proMMP-1). Each proMMP was subjected to treatment with a series of bacterial proteinases at molar ratios of 0.01-0.1 (bacterial proteinase to proMMP), and activities of MMPs generated were determined. Among six different bacterial proteinases, thermolysin family enzymes (family M4) such as Pseudomonas aeruginosa elastase, Vibrio cholerae proteinase, and thermolysin strongly activated all three proMMPs via limited proteolysis to generate active forms of the MMPs. N-terminal sequence analysis of the active MMPs revealed that cleavage occurred at the Val82-Leu83 and Thr90-Phe91 bonds of proMMP-1 and proMMP-9, respectively, which are located near the N terminus of the catalytic domain of MMPs. In contrast, Serratia 56-kDa proteinase and Pseudomonas alkaline proteinase, both of which are classified as members of the serralysin subfamily of zinc metalloproteinases (family M10), and Serratia 73-kDa thiol proteinase did not evidence proteolytic processing or activation of proMMP-1, -8, and -9 under these experimental conditions. These results indicate that bacterial proteinases may play an important role in tissue destruction and disintegration of extracellular matrix at the site of infections.

Amino Acid Sequence↗
PubMed1997

Basic fibroblast growth factor-induced glycosaminoglycan production in cultured vascular endothelial cells results from enhanced protein synthesis mediated by the lipoxygenase pathway.

To investigate the intracellular regulation of glycosaminoglycan (GAG) production induced by basic fibroblast growth factor (bFGF), bovine aortic endothelial cells were cultured with recombinant human bFGF in the presence of [3H]glucosamine or [35S]sulfate. It was shown that bFGF-induced incorporation of the radioactive precursors into GAGs was diminished by lipoxygenase inhibitors, nordihydroguaiaretic acid (NDGA) and esculetin, but not by a cyclooxygenase inhibitor indomethacin. A protein synthesis inhibitor cycloheximide also diminished the enhancement of the [3H]glucosamine incorporation by bFGF. On the other hand, the incorporation of [14C]leucine into the acid-insoluble fraction was strongly inhibited by NDGA but not by indomethacin in the presence or absence of bFGF. It was also shown that bFGF significantly increased the incorporation of [14C]xylose into GAGs. The present data suggested that bFGF may increase the number of GAG chains as a result of enhanced protein synthesis including xylosyl transferase through the lipoxygenase pathway of arachidonic acid metabolism in vascular endothelial cell layer.

Animals↗
PubMed1997

Involvement of the DNA replication-related element (DRE) and DRE-binding factor (DREF) in transcriptional regulation of the Bombyx mori PCNA gene.

The promoter region of the Bombyx mori gene encoding the proliferating cell nuclear antigen (PCNA), and its activating factor(s) were analyzed to ascertain similarities with Drosophila regulatory elements. Full promoter activity was established to reside within the region from -466 to +347 base pairs with respect to the transcription initiation site. Within this region, we found a sequence similar to the DNA replication-related element (DRE), 5'-TATCGATA, which is a promoter-activating sequence common to promoters of the Drosophila genes for DNA replication-related factors, including PCNA. A mutation in the DRE-like sequence of the B. mori PCNA gene promoter caused reduction of the promoter activity and also binding to the recombinant Drosophila DRE-binding factor (DREF). Furthermore, a factor(s) binding to the DRE sequence was detected in extracts of B. mori BmN4 cells. Monoclonal antibodies against Drosophila DREF inhibited the binding activity of the factor, as shown by gel mobility shift assays, and allowed specific detection of a 100 kDa protein on immuno Western blot analysis. These results suggest that the B. mori DREF homolog binds to DRE to regulate transcription of the PCNA gene.

Amino Acid Sequence↗
PubMed1997

[Hypertrophic cardiomyopathy showing no 123I-BMIPP myocardial accumulation with type I CD36 deficiency].

A 57 years old male consulted our hospital in complaining chest oppression and short of breath. Familial and dilated phase hypertrophic cardiomyopathy (HCM) was detected by ECG, echocardiography, left ventriculography and left ventricular endomyocardial biopsy. 201T1 SPECT showed regional increased accumulation in the ventricular septum, however, no myocardial accumulation of 123I-beta-methyl-p-iodophenylpentadecanoic acid (123I-BMIPP) was observed. We analyzed CD36 in this patient, and found he had type 1 CD36 deficiency. Myocardial uptake of long-chain fatty acids occurs via a specific transporter, which is homologous with human CD36. We hypothesize that CD36 deficiency, especially type 1 CD36 deficiency, might be one factor of no myocardial 123I-BMIPP uptake.

CD36 Antigens↗
PubMed1997

[Different patterns of 123I-BMIPP myocardial accumulation in patients with type I and II CD36 deficiency].

The CD36 molecule is a multifunctional membrane type receptor glycoprotein that reacts with thrombospondin, collagen, oxidized LDL and long-chain fatty acids (LCFA). LCFA are one of the major cardiac energy substrates, hence LCFA metabolism may have an important role in cardiac diseases. In this study, we analyzed CD36 expression in 200 patients with heart diseases [44 patients with hypertrophic cardiomyopathy (HCM), 16 with dilated cardiomyopathy (DCM), 26 with old myocardial infarction (OMI), 55 with angina pectoris (AP) and 59 with other miscellaneous heart diseases] using a flow cytometer. 123I-beta-methyl-p-iodophenylpentadecanoic acid (BMIPP) myocardial accumulation was also examined in some patients. Eight patients (2 with HCM, 1 with DCM, 2 with OMI, and 3 with AP) were diagnosed as having type I CD36 deficiency (neither platelets nor monocytes expressed CD36). Sixteen patients (3 with HCM, 1 with DCM, 1 with OMI, 8 with AP, and 3 with other heart diseases) showed type II CD36 deficiency (monocytes expressed CD36 but platelets did not). In all 8 patients with type I CD36 deficiency, there was no BMIPP accumulation in the heart. However, in 13 patients with type II CD36 deficiency, focally reduced BMIPP accumulation was observed, but there were no patients without BMIPP accumulation. CD36 deficiency was observed in a higher proportion (12%) of patients with heart disease in this study than in a reported control study. Type I CD36 deficiency is associated with absence of BMIPP accumulation in the heart, hence it may have an important role in LCFA metabolic disorders and some types of cardiac hypertrophy as well as other heart diseases.

Adult↗
PubMed1996

Sensitive response of cultured vascular smooth-muscle cells to cadmium cytotoxicity: comparison with cultured vascular endothelial cells and kidney epithelial LLC-PK1 cells.

Response to cadmium cytotoxicity of cultured bovine aortic smooth-muscle cells was compared with that of cultured bovine aortic endothelial cells and porcine kidney epithelial LLC-PK1 cells. The cell damage was evaluated by morphology and the lactate dehydrogenase leakage assay. It was found that vascular smooth-muscle cells are markedly sensitive to cadmium cytotoxicity. The accumulation of intracellular cadmium was much higher but that of metallothionein was much less in vascular smooth-muscle cells than in LLC-PK1 cells; vascular endothelial cells were in between vascular smooth-muscle cells and LLC-PK1 cells. The content of reduced glutathione was slightly increased by cadmium in all three cell types. The present data suggest that a much lower inducibility of metallothionein with a high accumulation of intracellular cadmium in vascular smooth-muscle cells resulted in a marked sensitivity of the cells to cadmium cytotoxicity. Vascular smooth-muscle cells may be one of the critical target of cadmium toxicity.

Animals↗
PubMed1996

DNA replication-related elements cooperate to enhance promoter activity of the drosophila DNA polymerase alpha 73-kDa subunit gene.

An analysis was carried out on the promoter region of the Drosophila DNA polymerase alpha 73-kDa subunit gene and the factor(s) activating the promoter. Transcription initiation sites were newly identified in the region downstream of the previously determined sites. Full promoter activity resided within the region from -285 to +129 base pairs with respect to the newly determined major site. Within this region, we found three sequences identical or similar to the DNA replication-related element (DRE), 5'-TATCGATA, which is known as a common promoter-activating element for the Drosophila DNA polymerase alpha 180-kDa subunit gene and the proliferating cell nuclear antigen gene. These sites were located at positions -77 to -70 (DREalpha-I), -44 to -37 (DREalpha-II), and +3 to +10 (DREalpha-III). Footprinting analysis using the recombinant DRE-binding factor (DREF) or Kc cell nuclear extract demonstrated that DREF can bind to all three DRE-related sites. Introduction of mutation in even one of the three DRE-related sequences caused extensive reductions of the promoter activity and also the DREF-binding activity of the promoter-containing fragment. The results indicate that the three DREF-binding sites cooperate to enhance promoter activity of the DNA polymerase alpha 73-kDa subunit gene.

Animals↗
PubMed1996

New PFG NMR Spectrometer with a Rotatable Quadrupole Coil for the Measurement of an Anisotropic Self-Diffusion Coefficient Tensor

A new pulsed-field-gradient spin-echo NMR spectrometer is reported which is specially designed for the measurement of slow and anisotropic self-diffusion by providing an intense and homogeneous field gradient of 12 T m-1 by a quadrupole coil and a high-quality current stabilizer, and also providing a mechanism by which both the sample cell and the quadrupole coil are rotated from the axis of the external field. Diffusion anisotropy is measured by a combination of coil rotation and magic-angle orientation of the sample. The theoretical basis for the method of measuring diffusion anisotropy, instrumentation details, and several sets of test data are given. The experimental results are reported for the rotation pattern of the diffusion coefficient of a smectic Ad liquid crystal of 4-octyloxy-N-(4-cyanobenzylidene)aniline. The component parallel to the layer normal is shown to be 2.1 times larger than the component within the layer.

Journal Article↗
PubMed1996

Induction of anti-malarial transmission blocking immunity with a recombinant ookinete surface antigen of Plasmodium berghei produced in silkworm larvae using the baculovirus expression vector system.

We have studied Pbs21, a major ookinete surface protein of Plasmodium berghei, for the development of a model transmission blocking immunogen. In the mouse, recombinant Pbs21 expressed in the Escherichia coli expression system (EcrPbs21) is not as effective in inducing transmission blocking antibodies as native Pbs21 (nPbs21), possibly because of differences in post-translational processing between EcrPbs21 and nPbs21. In an attempt to improve the efficacy of the recombinant molecule, we describe here the use of a baculovirus expression vector system in the silkworm Bombyx mori. Following an injection of recombinant baculovirus containing Pbs21 cDNA, B. mori larvae produced recombinant Pbs21 (BmrPbs21) with a molecular weight indistinguishable from nPbs21. Fifty micrograms of BmrPbs21 could be purified from the hemolymph of each infected larva using affinity chromatography. Immunization of Balb/c mice with BmrPbs21 induced high anti-BmrPbs21 and anti--ookinete antibodies but low anti-EcrPbs21 antibody. In contrast, EcrPbs21 induced high anti--EcrPbs21 antibody but low anti-BmrPbs21 and anti-ookinete antibodies. This suggests that most B-cell epitopes on nPbs21 are conformational and that many of the linear epitopes in EcrPbs21 are not normally exposed in nPbs21. Oocyst formation in Anopheles stephensi mosquitoes, which fed on mice immunized with purified BmrPbs21 and infected with P. berghei, was blocked by 85.5-97.1%. These results suggest that the baculovirus-silkworm system produces useful quantities of recombinant Pbs21 which in limited studies is structurally and immunogenically indistinguishable from the native molecule.

Animals↗
PubMed1995

Induction of metallothionein by thrombin in cultured vascular endothelial and smooth muscle cells.

Metallothionein induction by thrombin was investigated using a culture system of vascular endothelial and smooth muscle cells. It was found that the protease induced metallothionein in endothelial cells derived from human aorta and umbilical vein as well as bovine aorta in a concentration-dependent manner. Thrombin also induced metallothionein in vascular smooth muscle cells derived from bovine aorta but not in cells derived from human, rabbit and rat aortas. In bovine aortic endothelial and smooth muscle cells, induction of metallothionein by thrombin was unaffected by the protein kinase C inhibitor staurosporine; in addition, a protein kinase C activator, phorbol 12-myristate 13-acetate, failed to induce metallothionein, suggesting that the induction by thrombin occurred through pathway(s) other than protein kinase C activation. It is suggested that metallothionein may be induced during hemostasis in the vascular tissue through protein kinase C-independent pathway(s).

Animals↗
PubMed1995

Vascular smooth muscle cells in culture are highly sensitive to cadmium cytotoxicity without species-related differences: comparison with Chang liver cells.

Human, rabbit and rat aortic smooth muscle cells (hSMC, rSMC and A10 cells, respectively) were cultured with cadmium chloride and compared with human Chang liver cells to characterize the response of vascular smooth muscle cells to the metal. It was revealed that all tested vascular smooth muscle cells were markedly more sensitive to cadmium cytotoxicity than Chang liver cells. Cadmium accumulated more markedly in vascular smooth muscle cells than in Chang liver cells. After exposure to cadmium, metallothionein was induced in a concentration-dependent manner in Chang liver cells, it was constitutively high in hSMC, sensitively induced in rSMC and was constitutively low and induced within narrow limits in A10 cells. The intracellular content of reduced glutathione was greater and significantly enhanced by cadmium only in A10 cells. The present data suggest that vascular smooth muscle cells are, in general, sensitive to cadmium cytotoxicity without any species-related differences, mainly due to a higher accumulation of the metal within cells.

Animals↗
PubMed1995

[Detection of loss of heterozygosity by microsatellite probe and DNA content analysis].

We examined replication error (RER) and loss of heterozygosity (LOH) in the region of microsatellites in 60 cases of resected lung cancer. We used microsatellite probes for the short arm of the 2nd chromosome (D2S123, D2S136), the short arm of the 3rd chromosome (D3S1067), and the short arm of the 17th chromosome (TP53). According to stage, the frequency of LOH was 25% in stage I, 33% in stage II, 44% in stage IIIA, 11% in stage III B, and 63% in stage IV. According to histological classification, the frequency of LOH was 41% for squamous cell carcinoma, 24% for adenocarcinoma, and 100% for small cell carcinoma. According to microsatellite probe results, the frequency of LOH was 6.7% for D2S123, 5.0% for D2S136, 16.7% for D3S1067, and 18.3% for TP53. Two of the 60 cases showed RER. One case was stage I squamous cell carcinoma, and the other was stage IV adenocarcinoma. Except for stage III B,LOH in the microsatellite region increases with the stage. LOH is often detected in the order of small cell carcinoma, squamous cell carcinoma, and adenocarcinoma. According to the chromosome number, LOH is detected more often in the 3rd and 17th chromosomes than in the 2nd chromosome. In 20 cases with LOH, only two showed DNA diploidy. Compared to LOH of the microsatellite region, DNA content analysis by flow cytometry has accuracy problems.

Aneuploidy↗
PubMed1995

[The result of reoperation for lung cancer].

Twenty four patients with recurrent or multiple lung cancer were reoperated in our center. Five-year survival rate was 20% for 11 patients with recurrent, while was 25% for 13 patients with multiple after reoperation. The patients with limited operation had well survival and there was no significant difference in procedure. However all four patients with N2 had poor prognosis. Seven patients (29%) had the post reoperative complication in pulmonary system. All of them had the impairment of pulmonary function (FEV1.0% was less than 50%) or more than 75% perfusion ratio, measured with pulmonary perfusion scintigraphy, in the side of the reoperation.

Adenocarcinoma↗