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Biomedical subjects

S Eda

Publications and source records attributed to S Eda.

At least 37 records · Page 2Linked to original sources
PubMed1999

Mixed-type liposarcoma of the oral cavity: a case with unusual features and a long survival.

A case of mixed-type liposarcoma, which showed unusual dedifferentiation in the recurrence, is reported. The rapidly growing mass in the palate of a 60-year-old Japanese woman first revealed a combination of myxoid liposarcoma with features resembling storiform malignant fibrous histiocytoma. The recurrent neoplasm, showing an abrupt transition between myxoid and non-lipogenic parts, partially reverted to sclerosing well-differentiated liposarcoma. The patient died 10.1 years after the first operation.

Fatal Outcome↗
PubMed1999

A new method of measuring C-reactive protein, with a low limit of detection, suitable for risk assessment of coronary heart disease.

A new indication has been proposed for C-reactive protein (CRP) as a prognostic risk marker of coronary heart disease (CHD). The new indication calls for accurate (true and precise) measurement of CRP within the conventional reference range (< 5 mg/L). The existing turbidimetric and nephelometric methods do not cover the required measuring range and thus time-consuming and labour-intensive enzyme immunoassays have been used for the clinical studies focusing on CHD risk. We developed a new method based on microparticle enhanced turbidimetry, which attained the required limit of detection, while keeping the upper measuring limit comparable to the existing turbidimetric and nephelometric methods. The superior characteristics of the new method were realised by mixing two types of microparticle reagents differing in microparticle size and reactivity of coated antibody. The analytical detection limit of the method was 0.28 mg/L with use of only 2.5 microliters serum. The method showed good precision at 2 to 3 mg/L, the critical concentration range for CHD risk assessment. Other performance data including dilution linearity, method comparison, and interference study also met the requirements for the practical use in the clinical laboratories. Sera from 354 apparently healthy blood donors were measured in a reference range study. The reference range estimated after log-transformation was 0.16 mg/L to 7.57 mg/L CRP, with a total range of 0.09 mg/L to 21.0 mg/L. The distribution of CRP concentrations in this population was comparable to other results that established the use of CRP as a risk marker of CHD in a prospective study.

Antibodies, Monoclonal↗
PubMed1999

[Primary ciliary dyskinesia treated with living-donor lobar lung transplantation].

We report a case of primary ciliary dyskinesia in which a living-donor lobar lung transplant was performed. A 24-year-old woman with a diagnosis of primary ciliary dyskinesia and bronchiectasis was admitted to Shinshu University Hospital because of persistent dyspnea and pyrexia over a period of 4 months. Although she was given various antibiotics, neutrophilia, elevated plasma C-reactive protein (CRP) levels, and respiratory failure persisted. Chest roentgenograms and computed tomography disclosed severe bronchiectasis and diffuse infiltrative shadows in both lung fields. Pseudomonas aeruginosa was detected in a sputum culture. Although a variety of conventional therapies were administered, the patient's oxygenation progressively deteriorated. She was intubated and assisted by mechanical ventilation. The patient and her family proposed lung transplantation, and we concluded that a living-donor lobar lung transplant would be a suitable treatment for her disease. We transported the patient to Okayama University Hospital by helicopter 10 days after intubation. A living-donor lobar lung transplant was successfully performed with lung tissues donated by the patient's mother and sister for each transplant site.

Adult↗
PubMed1998

Development of a new microparticle-enhanced turbidimetric assay for C-reactive protein with superior features in analytical sensitivity and dynamic range.

Novel assay techniques were applied to a newly developed microparticle-based assay for C-reactive protein (CRP). By using two different sized microparticles covalently coated with two monoclonal antibodies of different reactivity, high analytical sensitivity and a high upper measuring limit could be simultaneously attained, resulting in a remarkably wide dynamic range. This range was further increased by calculating the signal (reaction rate) optimally with a new software capability of COBAS INTEGRA, a clinical chemistry analyzer. The assay showed high precision between 2 mg/l and 160 mg/l with use of only 2.5 microl specimen. The detection limit was estimated as 0.3 mg/l CRP. The assay was four to eight times more sensitive and precise than existing turbidimetric or nephelometric assays with comparable upper measuring limits. The assay also showed good linearity and correlated well with commercial assays. This new microparticle-based CRP assay provides the accuracy and precision that are required to determine CRP at low concentrations where new clinical implications such as prognosis of cardiovascular diseases are envisaged. The assay's wide dynamic range will additionally lead to a reduction in the number of repeated analyses, thus improving the efficiency of CRP determinations in clinical laboratories.

Angina Pectoris↗
PubMed1998

The effects of chemical modification on the adhesion of Plasmodium falciparum-infected and uninfected erythrocytes.

Binding of Plasmodium falciparum-infected erythrocytes (PE) to endothelial cells is mediated by the erythrocyte-membrane protein, band 3-related adhesin. To determine its role, the binding of infected cells treated with various chemical modifiers was investigated. Binding was inhibited by a lysine modifier (4,4'-diisothiocyanostilbene-2,2'-disulfonate (DIDS)) known to specifically bind to band 3, another lysine modifier (trinitrobenzene sulfonic acid), a tyrosine modifier (sodium iodide in conjunction with lactoperoxidase, hydrogen peroxide) and oxidants (diamide, sodium periodate and ADP-chelated ferric ion), but binding was unaffected by the histidine modifier (diethylpyrocarbonate) and the arginine modifier (phenyl glyoxyl monohydrate). To artificially expose the band 3-related adhesin, uninfected erythrocytes were treated with acridine orange or loaded with calcium. These cells bound to C32 amelanotic melanoma cells, were immunostained with a monoclonal antibody that specifically binds to the band 3-related adhesin on PE, and the binding was inhibited by this monoclonal antibody. The binding of acridine orange-treated and calcium-loaded uninfected erythrocytes, could also be blocked by DIDS. In the case of acridine orange-treated erythrocytes, the patterns of the effects of the chemical modification on binding were consistent with that of PE except for tyrosine modification. These results demonstrate that the band 3-related adhesin, even in the absence of parasite-encoded proteins, contributes to PE adhesion.

4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid↗
PubMed1998

Molecular and biological characterization of rabbit mannan-binding protein.

Mannan-binding protein (MBP) is a member of the collectin family of protein. There are two types of MBP, MBP-A and MBP-C, which were found in rodent (rats and mice), rhesus monkey, and cynomolgus monkey, while chimpanzee and human have only one MBP. It was considered that the loss of one MBP gene occurred during hominoid evolution. In this article two rabbit MBP, a liver and serum MBP, were characterized biologically and genetically. Analyses by SDS-PAGE under reduced condition and their amino acid sequences of both MBPs showed that they have a same molecular weight of 32 kDa and their amino acid sequences were identical. A serum MBP has a higher ability to activate complement than does a liver MBP; however, a liver MBP inhibits hemagglutination by influenza virus as strongly as a serum MBP does. cDNA clones encoding the rabbit MBP were isolated from a rabbit cDNA liver library using whole cDNA of mouse MBP-C as a probe. The cDNA carried an insert of 744 bp coding for a protein of 247 acid residues with a signal peptide of 22 residues. The deduced amino acid sequence of the cDNA was identical to that of amino acid sequences of the 32 kDa proteins determined here. Northern blot analysis showed that mRNA transcripts of about 0. 9 and 3.0 kb were expressed only in the liver. The analysis of the phylogenetic tree of rabbit and bovine MBPs and other collectins indicates that the loss of MBP gene occurred not only during hominoid evolution but also at some points after the separation of birds and mammals.

Amino Acid Sequence↗
PubMed1998

Characterization of truncated human mannan-binding protein (MBP) expressed in Escherichia coli.

Mannan-binding protein (MBP) is a calcium-dependent mammalian serum lectin important in first-line host defense. MBP belongs to the collectin family, which is characterized by an NH2-terminal cysteine-rich domain, a collagen-like domain, a neck domain, and a carbohydrate recognition domain (CRD). We have expressed a recombinant human MBP, consisting of the short collagen region (two repeats of Gly-Xaa-Yaa amino acid sequences), the neck domain, and the CRD, in Escherichia coli. The truncated MBP was capable of forming trimers by association of the neck domain and could bind sugar with a specificity similar to that of the native form. Results of hemagglutination inhibition (HI) assay of influenza A virus showed that the truncated MBP inhibited hemagglutination less strongly, although the native MBP induced the HI phenomenon. These results suggest that an oligomeric structure is an advantage for MBP to have full biological activity against influenza A virus.

Carrier Proteins↗
PubMed1998

[Mechanism of short-term improvement in exercise tolerance after lung volume reduction surgery for severe emphysema].

To investigate the mechanism of short-term improvement in exercise tolerance after lung volume reduction surgery (LVRS) for severe emphysema, we performed six-minute walk tests and pulmonary-function tests, and studied their correlation before and 3-to-5 months after LVRS in 7 patients with severe emphysema who underwent bilateral lung reduction via median sternotomy. Results of the tests showed a 59% increase in the 1-second forced expiratory volume (FEV1), a 25% reduction in the functional residual capacity (FRC), a 49% increase in the maximum voluntary ventilation (MVV), and a 20% increase in the distance walked in 6 minutes (6 MD). The degree of improvement in 6 MD correlated significantly with the degree of improvement in FEV1 (r = 0.97, p < 0.01), in FRC (r = 0.86, p < 0.05), and in MVV (r = 0.87, p < 0.05), and did not correlate with the degree of improvement in pulmonary gas exchange. These results support the hypothesis that an increase in lung elastic recoil after targeted emphysematous resection reduces airflow limitation, and thus leads to a short-term improvement in exercise tolerance after LVRS.

Aged↗
PubMed1997

Characterization of recombinant bovine conglutinin expressed in a mammalian cell.

We describe here the successful expression of recombinant bovine conglutinin in CHO cells as well as its physical and biological characteristics. Geneticin-resistant transformants harboring bovine conglutinin cDNA in the expression vector pNOW/CMV-A were screened by Western blot analysis for secretion into media of recombinant conglutinin. A four-day amplification of the transgene with increasing concentrations of methotrexate resulted in a dose-dependent increase in the production of recombinant conglutinin to a final concentration of 18.6 microg/ml of media. Recombinant conglutinin purified from this media by affinity column chromatography on mannan-agarose had a migration pattern similar to that of native conglutinin on polyacrylamide gel electrophoresis under reducing, nonreducing, and native conditions. The recombinant conglutinin exhibited sugar binding, conglutination, hemagglutination inhibition, and neutralization of influenza A virus, activities engaged in by the native conglutinin. This is the first report describing a high level of expression of a serum cruciform collectin with the full range of biological activity.

Animals↗
PubMed1997

An Escherichia coli topB mutant increases deletion and frameshift mutations in the supF target gene.

We have improved a system to examine forward mutations that occurred in the supF gene of Escherichia coli placed on a multicopy plasmid. Using this system, we determined the mutational specificity for a topB deletion mutator in which topoisomerase III is hampered. The frequency of supF- mutations in topB strain was 4.9 x 10(-7), that is essentially the same as that in wild-type strain, 3.1 x 10(-7). Half the number of the supF- mutations were large deletions, where a specific deletion among a 10-base pair direct repeat dominated, but other types of deletions were also found. Most of the deletions were associated with the presence of directly repeated sequences capable of accounting for their endpoints. Frameshift mutations in topB strain also significantly increased compared with those of wild-type (17 vs. 2%). Base substitutions comprised 27% of the events, specificity of which in topB strain was the same as that in wild-type strain. The present data suggest that topB is a novel class of mutator that strongly induces repeated sequence dependent deletion mutagenesis and high frequencies of frameshift mutagenesis.

Base Sequence↗
PubMed1997

Structure of a truncated human surfactant protein D is less effective in agglutinating bacteria than the native structure and fails to inhibit haemagglutination by influenza A virus.

Surfactant protein D (SP-D) is a lung-specific protein that is synthesized and secreted by lung epithelial cells and is believed to play an important role in lung host defence. This protein belongs to the C-type lectin family, which is characterized by an N-terminal cysteine-rich domain, a collagen-like domain, a neck domain and a carbohydrate recognition domain (CRD). To elucidate the biological actions of this animal lectin against such pathogens as micro-organisms, the biological activities of a recombinant partial SP-D lacking a collagen-like domain were examined. A recombinant human SP-D, consisting of a short collagen region (two repeats of Gly-Xaa-Yaa amino acid sequences), the neck domain and the CRD, was expressed in Escherichia coli. The recombinant SP-D was purified on a nickel column and then on a maltose-agarose column. This protein can form a trimeric structure owing to the neck domain and exhibits sugar-binding activity and specificity similar to those of native human SP-D. The recombinant SP-D caused dose-dependent and calcium-dependent agglutination of E. coli Y1088. The agglutination titre (the concentration required to achieve a 50% decrease in light transmission by agglutination) of recombinant SP-D was approx. 6-fold that of native SP-D. As for conglutination, the recombinant trimeric conglutinin required 8-16-fold higher concentrations than the native counterpart. In haemagglutination inhibition (HI) of influenza A virus, although native and recombinant conglutinin showed similar levels of HI activity, the recombinant SP-D was unable to inhibit haemagglutination, even at a concentration approx. 120-fold that of the native SP-D. The lectin precipitation and lectin blot assays showed that the truncated SP-D could bind to influenza A virus as well as native SP-D did. These results indicate that the agglutination activity of trimeric collectins can be largely retained, and furthermore that the oligomeric structure with several hands at opposite sites can enhance agglutination activity. The difference in HI activity against influenza A virus between native and recombinant SP-D suggests that SP-D uses a different mechanism from that of conglutinin to inhibit viral haemagglutination.

Agglutination↗
PubMed1997

Cloning and characterization of a cDNA encoding bovine mannan-binding protein.

To identify the bovine mannan-binding protein (MBP), a search for the cDNA homologue of human MBP was carried out. cDNA clones encoding bovine MBP were isolated from a bovine liver cDNA library using a cDNA fragment encoding a short collagen region, neck domain and carbohydrate recognition domain of human MBP. The cDNA carried an insert of 747 bp encoding a protein of 249 amino acid (aa) residues with a signal peptide of 19 aa. The mannan-binding protein fraction of bovine serum that eluted with 100 mM mannose from a mannan-Sepharose column was analyzed under reducing conditions by SDS-PAGE. The major band of 33 kDa obtained reacted with anti-human MBP rabbit serum. The partial aa sequence of the purified 33-kDa protein was identical to the aa sequence deduced from the obtained cDNA. Results of the passive hemolysis experiment using sheep erythrocytes coated with yeast mannan suggest that this MBP has the ability to activate complement. Northern blot analysis showed a 1.8-kb mRNA that was expressed only in the liver. Based on results of genomic analysis, this bovine MBP is likely to be a homologue of human MBP and to also have homology to rat and mouse MBP-C which are localized in liver cells rather than to rat and mouse MBP-A found in serum. Alignments of bovine collectins show that bovine MBP cannot be included among the other bovine collectins, such as bovine SP-D, conglutinin and CL-43. Finally, these genomic and biological analyses indicate that the cDNA obtained here encoded a bovine serum MBP.

Amino Acid Sequence↗
PubMed1997

Evaluation of heterotopic bone formation induced by squalane and bone morphogenetic protein composite.

Bone morphogenetic protein is an important molecule whose bioactivity depends on the carrier. Squalane is used in the formulation of various kinds of cosmetics because it is easily emulsified and has the property of spreading well. Thus, squalane might be effective as a bone morphogenetic protein delivery system. As a test for this possibility, gelatin capsules containing squalane and bone morphogenetic protein (bovine derived partially purified) composite were implanted under the hind-quarter perimuscular membrane of ddY mice. Control capsules containing only bone morphogenetic protein were used for controls. The implants were radiographically and histologically examined at 1 to 4 weeks after the operation. According to the radiographic analysis, squalane and bone morphogenetic protein composite and bone morphogenetic protein only control specimens formed widespread heterotopic bone tissues. The amount of heterotopic bone formation in the composite experimental specimens was approximately 40% greater than that in the controls. Histologic examination of experimental and control specimens revealed varying amounts of perichondral ossification by 2 weeks. By 3 and 4 weeks, the bone deposits were colonized by hematopoietic bone marrow. Squalane was effective for the slow local release of bone morphogenetic protein. Furthermore, the squalane and bone morphogenetic protein composite was a reliable osteoinductive biomaterial.

Animals↗
PubMed1997

The relations between expiratory chest CT using helical CT and pulmonary function tests in emphysema.

Chest computed tomography (CT) and pulmonary function tests are usually used for the evaluation of emphysema. We performed the present study to evaluate more accurately the relationship between the degree of morphological change and the functional abnormality in emphysema. We used a helical CT apparatus to obtain the CT images both at full inspiration and full expiration. We classed the degree of emphysema into 5 grades (0-4) by visual observation on CT image obtained at the two levels, upper and lower fields, on each side. We assigned each of these grades a visual score. We also calculated the average ratio of CT numbers of each of the lung fields at full expiration to that at full inspiration for each level. We designated this the E/I ratio. We then examined the relationship between the findings acquired by each of these two methods and pulmonary function test results. The visual score showed correlations with FEV1(% predicted) (-0.592, p < 0.0001), RV/TLC(%)(0.425, p < 0.025), and DL(CO)/VA(% predicted)(-0.538, p < 0.0001). The E/I ratio showed correlations with FEV1(% predicted) (-0.620, p < 0.0001), RV/TLC(%)(0.661, p < 0.0001), and DL(CO)/VA(% predicted) (-0.299, p < 0.05). Compared with the E/I ratio, the visual score showed much higher correlation with DL(CO)/VA(% predicted), but the E/I ratio showed stronger correlation with RV/TLC(%) than did the visual score. The visual score may reflect the degree of emphysema, whereas the E/I ratio reflects the air trapping. These findings suggest that the helical CT is useful in the evaluation of emphysematous changes and that the E/I ratio reflects the air trapping.

Aged↗
PubMed1997

Characterization of lactoferrin-binding proteins of human macrophage membrane: multiple species of lactoferrin-binding proteins with polylactosamine-binding ability.

Human lactoferrin (LF) specifically binds to human monocytic leukemia cell line THP-1 cells differentiated into macrophages, and it has been suggested that the poly-N-acetyllactosaminyl saccharide chains of LF are involved. We partially purified and characterized LF-binding proteins with affinity for polylactosamines from THP-1 cells. LF-binding activity was solubilized by nonionic detergent Triton X-100 from THP-1 cell membrane, and subjected to affinity chromatography using an LF-Sepharose column. LF-binding activity, detected by ligand blotting assay, was eluted and further fractionated by affinity chromatography using a Sepharose column coupled with band 3, a polylactosaminyl chain-containing glycoprotein of human erythrocyte membrane. LF-binding activity was separated into three fractions (frs. B1, B2, and B3). These fractions exhibited band 3-binding activity as detected by ligand blotting assay. Dodecylsulfate-polyacrylamide gel electrophoresis of frs. B1, B2, and B3, followed by detection of LF-binding activity on Western blots, indicated that frs. B1, B2, and B3 contained LF-binding proteins with a molecular mass of 35, 50 and 80, and 35-37 kDa, respectively. Binding of LF to each of the fractions on the dot blots was partially inhibited by LF oligosaccharides, band 3 oligosaccharides and lacto-N-neotetraose, each containing di-N-acetyllactosaminyl or analogous structure, Gal beta 1-->4GlcNAc beta 1-->3Gal beta 1-->4GlcNAc (or Glc). These results suggest that the 35, 50 and/or 80, and 35-37 kDa proteins on THP-1 cells are LF-binding proteins with polylactosamine-binding ability.

Amino Sugars↗
PubMed1997

Oxidatively damaged erythrocytes are recognized by membrane proteins of macrophages.

Human erythrocytes incubated with an iron catalyst ADP-chelated Fe3+ undergo oxidative damage of the membrane including lipid peroxidation, protein oxidation, and protein aggregation, and become susceptible to recognition by human macrophages. In order to clarify the membrane components of macrophages responsible for the recognition of the oxidized erythrocytes, binding of the oxidized cells to dot and Western blots of solubilized membrane of macrophages was investigated. The oxidized erythrocytes but not unoxidized cells bound to the dot blots. The binding was effectively inhibited by saccharide chains of band 3, a major glycoprotein of human erythrocytes, and lowered when the saccharide chains of band 3 were removed from the cell surface by pretreatment of the cells with endo-beta-galactosidase which specifically cleaves the polylactosaminyl saccharide chains of band 3. The oxidized erythrocytes bound to the membrane proteins of macrophages with molecular mass of about 50, 80, and 120 kDa on Western blots depending on the saccharide chains of band 3 on their surface. The results suggest that the oxidatively damaged erythrocytes are specifically recognized by these proteins of macrophage membrane having saccharide binding ability.

Anion Exchange Protein 1, Erythrocyte↗
PubMed1996

Recombinant bovine conglutinin, lacking the N-terminal and collagenous domains, has less conglutination activity but is able to inhibit haemagglutination by influenza A virus.

Conglutinin is a bovine serum protein which was first described as a vertebrate lectin. This protein belongs to the family of C-type lectins. These lectins are composed of four characteristic domains: (1) an N-terminal cysteine-rich domain, (2) a collagen-like domain, (3) a neck domain and (4) a carbohydrate recognition domain (CRD). Recently lectins have been shown to function as immunoglobulin-independent defence molecules due to a complement-mediated mechanism or opsonization. Our previous study showed that bovine conglutinin can inhibit haemagglutination by influenza A viruses and act by directly neutralizing them due to its lectin properties. In order to elucidate the biological role of the collagen-like domain, a recombinant partial conglutinin lacking this collagen-like domain was produced in an Escherichia coli system and its biological activities were examined. A 497 bp sequence, consisting of a short collagen region (two repeats of G-X-Y amino acid sequences), the neck domain, and the CRD of conglutinin cDNA, was amplified by the reverse-transcriptase PCR technique. The cDNA was transferred to a bacterial expression vector system (pRSET-A) and stable transfectants with a high level of conglutinin production were obtained. SDS/PAGE and Western blotting analyses showed a recombinant fusion protein of 27 kDa. Results of a cross-linking study and gel-filtration assay indicated that the recombinant conglutinin can form a trimeric structure and that it has sugar binding activity and specificity similar to that of native conglutinin. The recombinant conglutinin was also found to inhibit haemagglutination caused by influenza A virus as well as to possess less conglutination activity. These results suggest that in order for conglutinin to inhibit haemagglutination caused by the influenza virus, as well as to have sugar binding activity or to form trimers, it does not require the N-terminal and collagenous domains; however, they are essential for full conglutination activity.

Amino Acid Sequence↗