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Biomedical subjects

R Kawaguchi

Publications and source records attributed to R Kawaguchi.

At least 37 records · Page 2Linked to original sources
PubMed1997

Comparison of the nucleic acids of helical and coccoid forms of Helicobacter pylori.

The nucleic acids of the helical and coccoid forms of Helicobacter pylori were studied to determine if the coccoid forms are "viable (capable of growing) but nonculturable." Using a reference strain (NCTC 11638) and five clinical strains, the nucleic acid contents, DNA integrity, and results of PCR and reverse transcription-PCR (RT-PCR) were compared for helical H. pylori and coccoid forms induced using glycochenodeoxycholic acid or bismuth citrate. The DNA and RNA contents of the coccoid forms were respectively 6.8- and 8.1-fold lower than those of helical H. pylori after 3 days of induction and 11.5- and 14.7-fold lower after 7 days. Agarose gel electrophoresis of DNA extracted from the coccoid forms after 3 days of induction showed a smear pattern indicating DNA cleavage, whereas DNA from helical H. pylori showed a single band with a high molecular mass. After 12 days of induction, all RNA samples from 100% coccoid cultures were negative for the mRNA of urease A or the 26-kDa species-specific protein by RT-PCR. However, most RNA samples obtained after 3 or 7 days of induction were positive at low levels despite the lack of recovery from these cultures. These results suggest that the coccoid form of H. pylori has impaired genomic DNA and is in the process of cellular degeneration, thus being still alive but nonincreasable.

Bacterial Proteins↗
PubMed1997

[A case of life-threatening anaphylactoid reaction caused by povidone-iodine].

A 64 year-old man developed life-threatening anaphylactoid reaction caused by povidone-iodine during induction of anesthesia for elective coronary artery bypass graft surgery. While he had a history of cardiac arrest caused by iodine, he could tolerate contrast material and povidone-iodine for pre-operative coronary angiography with pretreatment of H1 and H2 receptor blockades and methylprednisolone. During the operation and postoperative care we could manage cardiac failure by continuous monitoring of cardiac output (CCO) using pulsed-thermodilution method. We recommend prophylactic use of H1 and H2 receptor blockades for surgical patients who may be at risk for anaphylaxis or anaphylactoid reaction.

Anaphylaxis↗
PubMed1997

[The efficiency of a new porous type leukocyte removal filter for red cell blood components, Terumo Imuguard III-RC, in the rapid transfusion conditions].

We evaluated the efficiency of a new porous type leukocyte removal filter for red cell blood components, Terumo Imuguard III-RC, in the rapid transfusion conditions. One leukocyte removal filter was used for 2 units of RC-M.A.P (red cell mannitol-adenine-phosphate). Filtration methods employed were gravity infusion, high pressure infusion (300 mmHg), pumping infusion and 20 ml.min-1 infusion under high pressure (300 mmHg). Blood samples were taken before and after the filtration to measure white blood cell (WBC), red blood cell (RBC) and platelet content. Blood samples before filtration and after filtration with WBC excluded, were examined by automated hematology analyzer (Coulter counter STKS-Retic). WBC after filtration was counted by the hemacytometer method using Nageotte Chamber. The removal rate of WBC was found to be more than 99.99% and residual WBC content was less than 4 x 10(4) with every method. The recovery rate of RBC was not significantly decreased in all filtration methods. The removal rate of platelet was equal in all filtration methods. In conclusion, Imuguard III-RC could be useful for effective homologous blood transfusion.

Blood Transfusion↗
PubMed1997

[Survey of sensitivities of clinical isolates to antibacterial agents (annual report)].

Research groups were formed in 20 institutions nationwide to investigate carbapenem resistance of clinical isolates. Activities of various antibacterial agents, principally carbapenems, were tested against clinical isolates collected from these institutions. The broth microdilution method was used to determine the minimum inhibitory concentrations (MICs) of 17 antibacterial agents for 1,326 strains of 11 bacterial species isolated at the institutions between October and December 1994. The results are as follows: 1. Carbapenems exhibited strong antibacterial activities against MSSA and Streptococcus pneumoniae. Their activities against Enterococcus faecalis were comparable to that of ABPC. Carbapenems showed low activities against MRSA. 2. OFLX exhibited the greatest antibacterial activity against Haemophilus influenzae, followed by MEPM. Antibacterial activities of the other carbapenems were comparable to those of FMOX, CTM, and ABPC. 3. The carbapenems showed high activities against Escherichia coli, Klebsiella pneumoniae, Enterobacter cloacae, and Bacteroides fragilis group. Their activities were greater than those exhibited by other beta-lactam antibacterial agents. The carbapenems also exhibited stronger antibacterial activities against Serratia marcescens than the other beta-lactam antibacterial agents, but some resistant strains were detected. 4. The antibacterial activities of carbapenems against Pseudomonas aeruginosa were comparable to those of CAZ, AZT, AMK.

4-Quinolones↗
PubMed1996

Nested-polymerase chain reaction for the detection of Helicobacter pylori infection with novel primers designed by sequence analysis of urease A gene in clinically isolated bacterial strains.

We have established a highly sensitive semi-nested PCR assay for the detection of H. pylori infection using gastric juice samples, which can be aspirated with disposable nasogastric tubes. The primers targeting H. pylori urease A gene were designed based on the sequence conservation analysis of sixteen H. pylori strains isolated from Japanese patients. The efficacy of the PCR assay, designated as the URA-PCR, was confirmed by in vitro and in vivo assessments. Its sensitivity was 97.5% in the gastric juice samples aspirated from forty patients with proven H. pylori infection, and was significantly higher than that obtained with previously described PCR assays.

Base Sequence↗
PubMed1996

Association of aldehyde dehydrogenase with inheritance of NIDDM.

To investigate the influence of the mitochondrial aldehyde dehydrogenase 2 (ALDH2) genotype on the clinical features of diabetes, 212 Japanese patients with non-insulin-dependent diabetes mellitus (NIDDM) (154 males and 58 females aged 17-83 years; mean age 58.2 years) were investigated. Genotyping of ALDH2 was performed by the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. The pattern of inheritance of diabetes and various clinical parameters was compared between active and inactive ALDH2 groups. Of the 212 subjects, 120 had active ALDH2 and 92 had inactive ALDH2. The percentage of patients with a diabetic mother was higher in the inactive ALDH2 group (32.6%) than in the active ALDH2 group (19.2%) (p < 0.05). The prevalence of proliferative retinopathy was lower in the inactive ALDH2 group than in the active ALDH2 group (p < 0.05). However, other clinical parameters showed no difference. We conclude that maternal inheritance of diabetes was common in the inactive ALDH2 group. The finding is suggestive of a relationship between alcohol intolerance and inheritance of diabetes. We speculate that the interaction between mitochondrial DNA and ALDH2 inactivity causes an increase of mitochondrial DNA mutations or deletions, thereby inducing the maternal inheritance of diabetes. The relationship of the ALDH2 genotype with proliferative retinopathy is interesting, because it resembles that of chlorpropamide alcohol flushing with severe diabetic retinopathy. The interaction of aldehyde dehydrogenase isoenzymes might have an aetiological role, since aldehyde dehydrogenase 1 plays an important part in oxidation of retinal to retinoic acid. However, the number of affected patients with proliferative retinopathy was small, hence, our result should be considered as a preliminary finding.

Adolescent↗
PubMed1996

Enzymatic activities of several K108 mutants of ribonuclease (RNase) Rh isolated from Rhizopus niveus.

We previously investigated the role of the Lys108 residue of ribonuclease (RNase) Rh from Rhizopus niveus, and suggested that Lys108 probably acts to stabilize the pentacovalent intermediate, and that an Arg residue could replace the role of Lys108. In RNase Le2 from Lentinus edodes, a homologous enzyme of RNase Rh, Lys108 is replaced by Thr. In this paper, the enzymatic properties of a K108T mutant and its analogous enzyme, K108S, were investigated to determine the effect of Thr and its analog, Ser at the 108th position on enzyme activity. The enzymatic properties of these mutant enzymes were compared with those of other mutant enzymes at this position (K108M, K108A, K108L). The results showed that Thr and Ser could replace Lys108 but resulted in only 2-20% of the activity of the native enzyme depending on the substrates used.

Amino Acid Sequence↗
PubMed1996

Mitochondrial aldehyde dehydrogenase in diabetes associated with mitochondrial tRNA(Leu(UUR)) mutation at position 3243.

OBJECTIVE: To ascertain why alcohol is prone to manifest unpleasant effects in diabetes associated with mitochondrial tRNA(Leu(UUR) mutation at position 3243 (DM-Mt3243), we investigated the genotype of aldehyde dehydrogenase (ALDH) 2 and alcohol dehydrogenase 2 (ADH2) in DM-Mt3243. RESEARCH DESIGN AND METHODS: Nineteen unrelated patients with DM-Mt3243 were included in the study (12 men and 7 women). They were recruited from approximately 700 diabetic patients at three different institutes, without prior information of alcohol habit. ALDH2, ADH2, and 3243 mutation were genotyped by polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP) methods. There were 461 unrelated Japanese individuals and 170 non-3243 mutant NIDDM patients enrolled as control subjects. RESULTS: In the DM-Mt3243 group, 15 (79%) patients had inactive ALDH2 and 18 (95%) had atypical ADH2. The frequency of the inactive ALDH2 genotype was higher than that in the normal control subjects (P < 0.002) and that in the NIDDM control subjects (P < 0.003). However, the frequencies of ADH2 genotype in the DM-Mt3243 group, the normal control subjects, and the NIDDM control subjects were not different. CONCLUSIONS: Inactive ALDH2 genotype was frequently observed in DM-Mt3243. It suggests that DM-Mt3243 is associated with ALDH2 inactivity. We speculate the trait of acetaldehyde accumulation on ALDH2 inactivity may favor mitochondrial DNA abnormalities, thereby worsening ATP production and impairing insulin secretion. In addition, the interaction of ALDH1 and ALDH2 may alter the retinoid metabolism in the pancreas, thereby influencing insulin secretion and precipitating diabetes. Thus, this association of ALDH2 genotype with DM-Mt3243 provides insight into the etiology of diabetes in the mitochondrial diseases.

Adult↗
PubMed1996

[Acute brain expansion during emergency neck clipping surgery for cerebral aneurysms in a patient with dilated cardiomyopathy].

A 61-year-old male with coma and undiagnosed dilated cardiomyopathy received emergency cerebral aneurysm surgery. Anesthesia was induced with thiamylal, fentanyl and vecuronium and maintained with 66% N2O and 1.0% isoflurane. Five hundred ml of 20% mannitol was infused in 30 min. At the end of the infusion, hypotension occurred. Immediately after the injection of ephedrine, acute brain swelling was observed. The operation was switched to external decompression. Post-operative echocardiography revealed the presence of dilated cardiomyopathy (DCM). The ejection fraction was 34%. Two weeks later, the second operation was scheduled. The anesthesia was induced with fentanyl, midazolam and vecuronium and maintained with N2O and 0.7% isoflurane. Nitroglycerine, lidocaine, PGE1, dopamine and dobutamine were infused throughout the operation. Five hundred ml of 20% mannitol was infused in 60 min. There were no considerable hemodynamic changes and no episode of brain expansion during operation. We conclude that the rapid infusion of mannitol can trigger acute cardiac failure and brain edema in patients with DCM.

Acute Disease↗
PubMed1995

Phylogenetic analysis of a novel sulfate-reducing magnetic bacterium, RS-1, demonstrates its membership of the delta-Proteobacteria.

Most of the 16S ribosomal RNA gene of a sulfate-reducing magnetic bacterium, RS-1, was sequenced, and phylogenetic analysis was carried out. The results suggest that RS-1 is a member of the delta-Proteobacteria, and it appears to represent a new genus. RS-1 is the first bacterium reported outside the alpha-Proteobacteria that contains magnetite inclusions. RS-1 therefore disrupts the correlation between the alpha-Proteobacteria and possession of magnetite inclusions, and that between the delta-Proteobacteria and possession of greigite inclusions. The existence of RS-1 also suggests that intracellular magnetite biomineralization is of multiple evolutionary origins.

Bacteria↗
PubMed1995

Detection of the three common mutations of adeninephosphoribosyltransferase deficiency among Japanese.

We analyzed DNA from six Japanese patients with adenine phosphoribosyltransferase (APRT) deficiency who developed 2,8-dihydroxyadenine (DHA) urolithiasis. These six patients were selected for DNA analysis since they were expected to possess allele(s) with mutations other than two known abnormalities, i.e. a missense mutation at codon 136 (APRT*J allele) and a nonsense mutation at codon 98. In three of the six patients an insert of four bases CCGA was detected in exon 3 by sequencing clones obtained from the genomic DNA. In two of the three patients, both of the two alleles had this mutation (homozygotes) while the other patient had the APRT*J allele in addition to the allele with the 4-base insertion. To search for mutations other than the above three defined germline mutations, we amplified a genomic DNA segment including all the 5 exons of the APRT gene by PCR and cloned it into a plasmid. After selecting recombinant plasmids containing neither of the three defined mutations, we sequenced the entire APRT exons and introns. Abnormalities were found in neither the coding regions nor the exon-intron junctions. Disease-related mutations in these mutant alleles may exist in either 5' or 3' flanking sequences and remain to be elucidated.

Adenine Phosphoribosyltransferase↗
PubMed1995

Hepatitis E virus (87A strain) propagated in A549 cells.

A strain of hepatitis E virus (HEV), the 87A strain isolated in 2BS cells from the feces of a patient with hepatitis E, has been reported previously. In this study, the 87A strain was propagated in A549 cells, and the marked cytopathic effect (CPE) appeared in the infected monolayer cells. The size of this virus is about 30 nm in diameter. Furthermore, HEV-RNA from the supernatants of the virus of different passages was detected by polymerase chain reaction (PCR) amplification using ET1.1 HEV primers. A band of HEV for 239 bp from PCR products was revealed by electrophoresis. PCR products of the fourth passage were sequenced. These results show that the 87A virus replicates in the A549 cell line.

Animals↗
PubMed1995

Existing variations on the gene structure of hepatitis E virus strains from some regions of China.

The isolation and identification of the 87A strain of hepatitis E virus (HEV) by means of cell culture have been described previously. This paper reports the nucleotide sequence of a portion of this HEV strain. The RNA extracted from the supernatants of the different passages of the 87A strain cultured in the A549 cell line was reverse-transcribed (RT) to cDNA, and then the polymerase chain reaction (PCR) amplification was carried out using the primers of HEV ET1.1 region. The PCR products from 1) the supernatant of the infected cells at the fourth passage, 2) the virus concentrated by polyethylene glycol (PEG) precipitation at the tenth passage, and 3) the virus purified by a sucrose gradient at the tenth passage were sequenced. In addition, three other PCR products obtained from sera of acute hepatitis E patients in Beijing (B-9) and Guangzhou (G-9 and G-20) were also sequenced. The nucleotide sequences of the above four strains of HEV (located in the genome from positions 4545-4754) were compared to those of some reported HEV strains. The nucleotide sequences of the B-9 strain and the 87A strain were similar to the Burmese strain and may belong to the same branch of HEV. The nucleotide sequences of the G-9 strain and the G-20 strain were a novel and unique branch. The Chinese HEV strains are multiplex and variable in gene structure.

Acute Disease↗
PubMed1995

Establishment of a myeloid leukaemic cell line (SKNO-1) from a patient with t(8;21) who acquired monosomy 17 during disease progression.

A novel cell line SKNO-1 was established from the bone marrow cells of a 22-year-old male suffering from acute myeloblastic leukaemia (AML) M2 with t(8;21) whose disease became resistant to chemotherapy after acquisition of 17 monosomy. SKNO-1 has been maintained for more than 36 months as a granulocyte-macrophage colony-stimulating factor (GM-CSF) dependent line. Morphologically, SKNO-1 cells were myeloblasts somewhat matured. The cells grow in suspension with a doubling time of 48-72 h. The survival and growth of SKNO-1 cells was absolutely dependent on granulocyte-macrophage colony stimulating factor (GM-CSF). SKNO-1 cells possessed t(8;21) and monosomy 17 which were observed in original leukaemic cells. We confirmed that the AML1 gene, located on chromosome 21, was rearranged and the AML1-MTG8 fusion transcript was expressed in SKNO-1 cells. Over-expression and mutation of the p53 gene were also detected in SKNO-1. It is likely that alterations of AML1 or MTG8 gene and p53 gene contribute to a disease progression in this case. Since t(8;21) translocation is a common chromosome abnormality in AML, and inactivation of the p53 gene may play a crucial role in disease progression in AML, SKNO-1 would be a useful tool for analysing the molecular mechanisms in myeloid leukaemogenesis.

Adult↗
PubMed1994

Rapid identification of the common apo E isoform genotype using polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP).

Polymerase chain reaction single-strand conformation polymorphism (PCR-SSCP) was used to identify the common apoprotein E (apo E) isoform genotypes. DNA from the target sequence on apo E was amplified by PCR from peripheral blood genomic DNA. Non-radiolabelled natural PCR products were electrophoresed on a polyacrylamide gradient gel and automatically silver-stained. Bands compatible with each of the three common apo E isoforms were obtained. This method, which does not require restriction enzymes or DNA purification, is a rapid and useful means of detecting the apo E isoform genotype.

Apolipoproteins E↗
PubMed1994

Sequence of a 2.6-kb cryptic plasmid from a marine cyanobacterium Synechococcus sp.

We have shown previously that the copy number of plasmid pSY10 from the marine cyanobacterium Synechococcus sp. NKBG 042902 is dependent on the salinity of the growth medium. We report here the complete nucleotide sequence (2561 bp) of this plasmid. The longest open reading frame, ORF-B (1.08 kb), occurs on a 1.6-kb EcoRI fragment. This ORF encodes a putative protein which is 360 aa residues in length and is 37.8% homologous to the replication protein of plasmid pCA2.4 from Synechocystis sp. strain PCC 6803, 35.8% homologous to an ORF from the Nostoc plasmid pGL2, and 33.2% homologous to the ORF of a plasmid from Lactobacillus plantarum, pC30il. Highly conserved regions of amino acid sequence were also found between ORF-B and other bacterial plasmids.

Amino Acid Sequence↗