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Biomedical subjects

M Kawano

Publications and source records attributed to M Kawano.

At least 91 records · Page 5Linked to original sources
PubMed1999

Isolation and characterization of monoclonal antibodies directed against murine FRP-1/CD98/4F2 heavy chain: murine FRP-1 is an alloantigen and amino acid change at 129 (P<-->R) is related to the alloantigenicity.

Nineteen mAb directed against murine fusion regulatory protein-1 (mFRP-1)/4F2/CD98 were isolated and their biological properties were analysed. Intriguingly, mFRP-1 was found to be an alloantigen, namely, FRP-1.1 (DBA/2 and CBA mice type) and FRP-1.2 (BALB/c, C57BL/6 and C3H/He mice type). The nucleotide sequences of FRP-1.1 and FRP-1.2 were determined, demonstrating that amino acid change at 129 (P<-->R) is related to the alloantigenicity. mFRP-1 is expressed on thymocytes, on spleen cells, on peripheral lymphocytes and on blood monocytes, suggesting that the physiological role in vivo of murine FRP-1 is different from that of human FRP-1. The biological activities of antimFRP-1 mAbs showed by the present study are: (i) enhancement of Newcastle disease virus-induced cell fusion; (ii) suppression of HIVgp160-mediated cell fusion; and (iii) induction of aggregation and multinucleated giant cells of monocytes/macrophages.

Amino Acid Sequence↗
PubMed1999

Cross-cultural comparison of long-term psychiatric patients hospitalized in Tokyo, Japan and Honolulu, Hawaii.

The aim of this study is to cross-culturally explore the crucial and often conflicting issues of least restrictive placement of long-term psychiatric patients in Hawaii and Japan, and the need to provide high-quality care for such patients. Policy implications are discussed. A survey instrument facilitated the comparison of records from psychiatric patients hospitalized over 1 year in Hawaii, as of January 1993, and psychiatric patients hospitalized over 1 year in Japan, as of January 1996. The survey instrument was translated and validated for use in both countries. Interrater reliability averaged 0.96. The 30 subjects in Japan were all men (Japanese), and primarily unmarried. The 83 subjects in Hawaii were mostly men (Hawaiian or other ethnic minority), and unmarried. Subjects in Japan tended to be older, hospitalized longer, and were judged to be more dysfunctional than those in Hawaii. No significant relationship was revealed between nursing diagnoses and Axis I diagnoses in either sample. Although significant clinical differences were found between the two groups, the policy issues are similar: how to place patients in the least restrictive environment and how to provide high quality of care given the limited available resources. Nurses in both countries must become more vocal advocates for policy changes to improve the care of long-term patients.

Adult↗
PubMed1999

Characterization of violaxanthin de-epoxidase purified in the presence of Tween 20: effects of dithiothreitol and pepstatin A.

Violaxanthin de-epoxidase (VDE) was purified from thylakoid membranes of spinach by conventional column chromatography in the presence of Tween 20. The neutral detergent was necessary to prevent non-specific interaction of VDE with column resins. In anion-exchange chromatography on Mono Q, VDE appeared in two peaks. Both peaks exhibited a polypeptide of 41 kDa when fully reduced with 5 mM dithiothreitol. Re-chromatography of either peak gave rise to both peaks, suggesting that the two forms of VDE are interconvertible. VDE characteristically changed its electrophoretic mobility depending on the concentration of dithiothreitol with which the protein was treated. When non-reduced, it showed two polypeptides of 43 and 42 kDa. These polypeptides moved down to the position of 40 kDa, and then up to the position of 41 kDa, along with the increase in the dithiothreitol concentration from 0 to 2 mM. These findings suggest that VDE has more than one disulfide bond and takes multiple forms depending on the extent of the reduction. Studies with various types of protein-modifying reagent revealed that VDE is sensitive to pepstatin A, a specific inhibitor of aspartic protease. This finding suggests that the reaction center of VDE contains a reactive aspartic acid residue(s).

Amino Acid Sequence↗
PubMed1999

[Percutaneous dilational tracheostomy: report of 9 cases].

Nine patients with CNS damage who had been transferred to our critical care unit were treated with a commercially available kit for percutaneous dilational tracheostomy (PDT). The mean procedure time was about 11 minutes, and the perioperative complication rate was 22% (2/9). Only one complication, wound infection, occurred, and the patient was cured with conventional therapy. On the other hand, premature extubation of the translaryngeal tube occurred in one case. Long-term complications like tracheal stenosis and tracheal malacia were not experienced in two patients. They were discharged from the hospital after decannulation. In conclusion, the advantages of PDT include a short procedure time, the ability to perform the procedure at the bedside, and reduced stimulation of the trachea. Because of the safety and simplicity of the procedure, we recommend PDT for patients with CNS damage.

Adult↗
PubMed1999

[New classification of diabetes by ADA and WHO with special reference to pathogenesis].

New classification of diabetes mellitus was proposed by ADA international committee on the diagnosis and classification and by WHO consultation committee. The classification based on the pathogeneses of diabetes and also on the stages of diseases. Since our knowledge on causes of diabetic syndrome is not yet enough to classify diabetes in genetic bases, the classification had been carried out some sort of mixture of pathogeneses, genetic findings and clinical features of hyperglycemia. Stages of diseases based on the natural course of diabetes mellitus in reference to shortage of insulin effects and degree of chronic hyperglycemia. These two components of classification composed two dimensions of the field that expresses all the pathogeneses and metabolic conditions of all diabetic patients.

Diabetes Mellitus↗
PubMed1998

Role of carboxyl residues surrounding heme of human cytochrome b5 in the electrostatic interaction with NADH-cytochrome b5 reductase.

To identify the cytochrome b5 residues responsible for the electrostatic interaction with NADH-cytochrome b5 reductase (b5R), we prepared and characterized the cytochrome b5 mutants in which Glu41, Glu42, Glu63, Asp70, and Glu73 were replaced by Ala, utilizing site-directed mutagenesis and the expression system for cytochrome b5 in Escherichia coli. Apparent Km values of the wild type b5R for Glu42Ala cytochrome b5 and Asp70Ala cytochrome b5 were approximately three-fold and six-fold higher than that for the wild type cytochrome b5, respectively, while the kcat values for those mutants were not remarkably affected. In contrast, Glu41Ala, Glu63Ala, and Glu73Ala cytochrome b5 showed almost the same kinetic properties as the wild type cytochrome b5. Furthermore, kinetic studies on combinations of the cytochrome b5 and b5R mutants suggested the interaction between Glu42 and Asp70 of cytochrome b5 and Lys125 and Lys41 of b5R, respectively, in the reaction.

Amino Acid Substitution↗
PubMed1998

Mouse alloantigen Ly10 is identical to murine fusion regulatory protein-1 (mFRP-1)/4F2/CD98: aberrant expression of mFRP-1/Ly10 allotypes in cells derived from CDF1 mice due to the gene deletion.

Murine FRP-1 (mFRP-1) and Ly10 antigens are alloantigens. Anti-Ly10.1, monoclonal antibody (mAb) reacts to HeLa cells stably expressing mFRP-1.1 (HeLa cells/mFRP-1.1), but does not react to HeLa cells/ mFRP-1.2. On the other hand, anti-Ly10.2 mAb reacts to HeLa/mFRP-1.2 cells, but does not react to HeLa cells/mFRP-1.1. These findings indicate that Ly10.1 and Ly10.2 antigens are identical to the heavy chains of mFRP-1.1 and mFRP-1.2 molecules, respectively. Thymocytes and fibroblast cells obtained from CDF1 and BDF1 mice showed reactivity to both anti-Ly10.1 and anti-Ly10.2/FRP-2 antibodies, indicating that mFRP-1/Ly10 alloantigens are codominantly expressed in the F1 mice. Intriguingly, IMC carcinoma cells, derived from CDF1 mice, express mFRP-1.2, but do not express mFRP-1.1. Surprisingly, DBT cells, derived from CDF1 mice, consist of two different cell populations: one expresses both mFRP-1.1 and mFRP-1.2 antigens and the other expresses only mFRP-1.1 antigen. Consequently, we tried to isolate cloned DBT cell lines by limiting dilution. Finally, six cloned DBT cell lines were obtained, and three clones of these cloned DBT cells expressed both mFRP-1.1 and mFRP-1.2, and another three clones of these cloned DBT cells expressed both mFRP-1.1 and mFRP-1.2, and another three clones including clone 5 cells expressed only mFRP-1.1 antigen. No induction of mFRP-1.2/Ly10.2 by 5-azacytidine and sodium n-butyrate could be detected in DBT clone 5 cells. Neither mFRP-1.2 mRNA nor the genomic cDNA clone encoding mFRP-1.2 could be detected in DBT clone 5 cells, nor could the genomic cDNA encoding mFRP-1.1 be detected in IMC cells, indicating that aberrant expression of mFRP-1/Ly10 allotypes in CDF1 mice-derived cells is due to the gene deletion.

Animals↗
PubMed1998

Identification of 5' flanking sequence of RH50 gene and the core region for erythroid-specific expression.

The Rh blood group antigens are carried by two distinct but homologous membrane proteins encoded by two closely related genes, RCHE and RHD. Rh50 glyco-protein is the membrane protein tightly associated with Rh polypeptides and is critical for expression of Rh antigens. The amino acid sequence and predicted membrane topology of Rh50 glycoprotein are significantly homologous with those of the Rh proteins. Northern blot analysis of leukemic cell lines showed that expression of RH50 gene is restricted to cells with erythroid features. HEL and K562 cells showed a transcription levels ratio of 1 to 9.9 for Rh50, and 12.3 to 1 for Rh. The nucleotide sequence of 5' flanking region of RH50 gene and functional promoter assays also supported the erythroid-specific regulation of the gene, whereas the sequence had lower homology with the promoter sequence of RH genes. Seven GATAs, nine E-boxes, two CACCCs, one YY1, and one October motif were identified in the 1868bp 5' flanking sequence. The core promoter of RH50 gene was located within 68bp length from the translation start position, which included an inverse GATA motif, although obvious motifs for Sp1 or erythroid Krüppel-like factor were lacking. The inverse GATA motif was the target sequence of GATA-1 protein, and disruption of the motif abolished the transactivating activity of erythroid cells. These studies confirm the erythroid-specific expression of Rh antigens, but suggest distinct regulatory mechanisms for RH vs RH50 genes.

Amino Acid Sequence↗
PubMed1998

An atherogenic midband lipoprotein: a risk factor for coronary artery disease in diabetes mellitus with hyperlipidemia.

On polyacrylamide gel (PAG) disc electrophoresis of serum lipoproteins, the band(s) which migrates between pre beta- and beta-lipoproteins was more frequently observed in hyperlipidemics with diabetes mellitus (73%), than in those without diabetes mellitus (37%) (P < 0.01). Those bands were seen at three positions between pre beta- and beta-lipoproteins. A higher incidence of coronary artery disease (CAD) was observed in patients with midband as a shoulder of beta-lipoproteins (44%), than in those without midband (11%) (P < 0.05) after the matching of other risk factors. These results suggest that midband as a shoulder of beta-lipoproteins may be a risk factor for CAD in diabetes mellitus with hyperlipidemia.

Coronary Disease↗
PubMed1998

Expression analysis of human Rhesus blood group antigens by gene transduction into erythroid and non-erythroid cells.

Rh blood group antigens are associated with non-glycosylated human erythrocyte membrane proteins encoded by two closely related genes, RHCE and RHD, and with a glycoprotein, a critical co-expressing factor encoded by the RH50 gene. The sequence analysis of RHCE transcripts has revealed that RhE/e and C/c serological phenotypes are associated with a nucleotide substitution in exon 5 and six substitutions in exons 1 and 2 of RHCE gene, respectively. Smythe et al. have shown that the full length transcript of RhcE gene expressed c and E antigens and the transcript of RhD gene expressed D and G antigens, using retroviral-mediated gene transduction into K562 cells. We performed an epitope analysis of Rh antigen by constructing retroviral gene coding six RH cDNAs, which contain RhcE, ce, CE and D cDNAs, and CE-D, D-CE chimera cDNAs. The cDNAs were introduced into KU812E cells and the expressed antigens were analyzed by flow cytometry. These studies revealed that the C/c and E/e associated substitutions actually participated in respective polymorphic epitopes. However, the C antigen was not detected on the KU812E cells introduced with CE cDNA, despite E antigen being expressed. The study with the chimera gene between CE and D cDNAs also indicated that the Rh epitopes were not constructed with short polymorphic exofacial peptide loops only but also with other peptide fragments and membrane components. Co-expression studies of Rh50 and RhD or cE gene in non-erythroid cells, 293, and expression studies of Rh50 in another erythroid cell, HEL, did not show any Rh antigens on the transduced cells, despite the Northern blot study showing both transcripts in the cells. It was suggested that at least a second co-expressing factor was needed to express RhCE or D antigens on the plasma membrane.

Cell Line↗
PubMed1998

A splicing mutation of the RHAG gene associated with the Rhnull phenotype.

Rhnull is a syndrome serologically characterized by the deficiency of all Rh antigens on human red blood cells. Rhnull is divided into two types: regulator and amorph. Recently, Cherif-Zahar et al. proposed that the RHAG gene encoding the Rh50 glycoprotein is a candidate for inducing regulator type Rhnull. We investigated both the RH and RHAG genes in an Rhnull individual. The reticulocytes from the propositus had RHD, RHcE, and RHCe transcripts without any mutation. However, the sequence analysis of RHAG cDNA showed a deletion of 122 bp from nucleotide 946 to 1067. This deletion was revealed to be due to a homozygous splicing mutation, which is a single base substitution at the consensus sequence of the splicing acceptor site (AG-->AT). The mutation appeared to break the 'GT-AG' splicing rule and to cause 122 bp exon skipping accompanied by a frameshift. This study confirms that the RHAG gene is the most likely candidate for the 'regulator' gene of Rhnull cases.

Adolescent↗
PubMed1998

Fatal cardiac beta2-microglobulin amyloidosis in patients on long-term hemodialysis.

We report two long-term hemodialysis patients who developed severe congestive heart failure attributable to cardiac heavy amyloid deposition. Both patients became hypotensive during dialysis sessions, gradually making it difficult to continue hemodialysis, and they died of congestive heart failure. At autopsy, left ventricle walls in each case contained diffuse extensive deposits of amyloid. The distribution of amyloid was not localized to vessel walls but was widely disseminated throughout the left ventricle walls and replaced myocardial muscle fibers. Immunohistochemical examination showed positive staining for anti-human beta2-microglobulin antibody. We conclude that cardiac dialysis-related amyloidosis should also be considered in long-term hemodialysis patients with congestive heart failure as a life-threatening complication.

Amyloidosis↗
PubMed1998

Identification of regions on the fusion protein of human parainfluenza virus type 2 which are required for haemagglutinin-neuraminidase proteins to promote cell fusion.

Using a plasmid expression system in HeLa cells, we have previously shown that the fusion (F) protein of simian virus 41 (SV-41) induces cell fusion when coexpressed with the haemagglutinin-neuraminidase (HN) protein of human parainfluenza virus type 2 (PIV-2), while the PIV-2 F protein does not induce cell fusion with the SV-41 HN protein. In the present study, we found that the PIV-2 F protein induced extensive cell fusion with the HN protein of mumps virus (MuV), whereas the SV-41 F protein did not. Chimaeric analyses of the F proteins of PIV-2 and SV-41 identified two regions (designated M1 and M2) on the PIV-2 F protein, either of which was necessary for chimaeric F proteins to show fusogenic activity with the MuV HN protein. Subsequently, two additional regions (P1 and P2) were identified on the PIV-2 F protein, both of which were necessary for chimaeric F proteins to prevent induction of cell fusion with the SV-41 HN protein. Consequently, it was proved that a given chimaeric F protein, harbouring regions P1 and P2 together with either of region M1 or M2, induced cell fusion specifically with HN proteins of PIV-2 and MuV, the same as the PIV-2 F protein. Region M2 was located at the membrane proximal end of the PIV-2 F1 ectodomain, while regions P1, M1 and P2 clustered together in the middle of the ectodomain. These regions on the PIV-2 F protein may be involved in a putative functional interaction with HN proteins, which is considered to be a prerequisite for cell fusion.

Amino Acid Sequence↗
PubMed1998

Left acute scrotum associated with appendicitis.

A 10-year-old boy, who had a mild inguinal hernia in his left scrotum, was referred to our clinic because of redness of the scrotal skin and tenderness of the left scrotal contents. Scrotal echography showed a hypoechoic lesion around the normal testis and epididymis. Because torsion of either the testis or testicular appendage was suspected, the scrotum was opened and 1.5 mL of purulent fluid was observed in the tunica vaginalis with inflammatory tissue around the testis and epididymis. On the first postoperative day, a low grade fever and abdominal tenderness persisted, however, the abdomen was flat and soft. There was no marked tenderness over McBurney's point, but there was moderate tenderness over Lanz's point on deep palpation. Abdominal sonography and magnetic resonance imaging revealed abscess formation between the bladder and the sacrum. With a diagnosis of perforation of the appendix, a laparotomy was performed. The inguinal hernia sac could not be observed on inspection, and it was not possible to palpate the left side because of severe adhesion due to infection. Also, the neck of the right inguinal sac could not be seen. The appendix specimen was gangrenous. On the second postsurgical day, all symptoms and signs disappeared. We present this rare condition and discuss the difficulty in establishing a diagnosis.

Acute Disease↗
PubMed1998

The Na+-responsive ntp operon is indispensable for homeostatis of K+ and Na+ in Enterococcus hirae at limited proton potential.

Enterococcus hirae ATCC 9790 grew well in Na+-deficient, low-K+ medium, but growth was inhibited by carbonylcyanide m-chlorophenylhydrazone (CCCP). Growth inhibition and decrease of cellular K+ levels in the presence of CCCP were relieved by the addition of Na+ and a high concentration of K+. In contrast, in the mutant defective in Na+-ATPase or the NtpJ component of the KtrII K+ uptake system, CCCP-induced growth inhibition was rescued by a high concentration of K+ but not of Na+. These transporters are thus indispensable for homeostatis of K+ and Na+ at low proton potential.

Carbonyl Cyanide m-Chlorophenyl Hydrazone↗