Search PubMed⌕ Search

Biomedical subjects

F Kishi

Publications and source records attributed to F Kishi.

At least 55 records · Page 3Linked to original sources
PubMed1995

Cloning, DNA sequencing, and amino acid sequencing of catechol 1,2-dioxygenases (pyrocatechase) from Pseudomonas putida mt-2 and Pseudomonas arvilla C-1.

Catechol 1,2-dioxygenase catalyzes the oxygenative ring cleavage of catechol to form cis,cis-muconic acid and is encoded by a catA gene. We have cloned a catA gene from Pseudomonas putida mt-2 using a PCR product of amino acid sequence-based primers as a probe. The amino acid sequence deduced from the 930 nucleotides was in complete agreement with the chemically determined sequence of the protein. Crude extracts of Escherichia coli cells carrying the catA gene downstream from the lac promoter showed the enzyme activity. By using the same probe, we also cloned and sequenced the catA beta gene for catechol 1,2-dioxygenase isozyme beta beta from Pseudomonas arvilla C-1, which has three isozymes, alpha alpha, alpha beta, and beta beta (C. Nakai, H. Horiike, S. Kuramitsu, H. Kagamiyama, and M. Nozaki, 1990, J. Biol. Chem. 265, 660-665). There was very high homology between isozyme beta beta of the C-1 strain and the enzyme of the mt-2 strain in both the amino acid (98%) and the DNA sequences (97%). A preference for the use of codons terminating in C and G was found in the coding region of both the enzymes, which contributed to the high G + C content (65-66%) of the genes. A comparison of the DNA sequences of various catA genes from other sources revealed their common ancestry, whereas a comparison of the amino acid sequences of the enzymes revealed clear reflection of substrate specificity. Tyrosyl and histidyl residues for proposed ligands of ferric ion are conserved in all catechol 1,2-dioxygenases.

Amino Acid Sequence↗
PubMed1995

MCI-154 activates the Ca(2+)-activated K+ channel of vascular smooth muscle cells.

The aim of this study was to examine the effects of MCI-154, a new positive inotropic agent with vasodilating properties, on the Ca2+-activated K+ channel (KCa channel) of vascular smooth muscle cells. Cultured smooth muscle cells from a porcine coronary artery were studied using the patch-clamp technique. Extracellular application of 100 microM MCI-154 activated the KCa channel in intact cell-attached patch configurations. In excised inside-out patch configurations, application of 100 microM MCI-154 to the cytosolic side activated the KCa channel directly, suggesting that the Ca2+ sensitivity of the KCa channel itself is modulated. Though extracellular application of 100 microM amrinone, a phosphodiesterase inhibitor, activated the KCa channel in the cell-attached patch configurations, application of 100 microM amrinone to the cytosolic side could not activate the KCa channel in inside-out patch configurations. These results indicate that different from amrinone, MCI-154 can modulate Ca2+ sensitivity of the KCa channel in vascular smooth muscle cells.

Amrinone↗
PubMed1995

Efficacy of interferon alfa therapy in chronic hepatitis C patients depends primarily on hepatitis C virus RNA level.

To clarify the viral factors that may predict the therapeutic effect of interferon (IFN) in chronic hepatitis C (CHC) patients, we investigated the quantitative serum hepatitis C virus (HCV) RNA level, genotype, and liver biopsy histological features in 60 patients who were treated with 360 x 10(6) U of natural IFN-alpha for 36 to 48 weeks and for more than 12 months after therapy. A branched DNA (bDNA) assay was used to measure HCV RNA levels. All responders, defined as those individuals with normal alanine transaminase (ALT) levels at 48 weeks after therapy, had less than 2 x 10(6) HCV RNA Eq/mL before administration of IFN. Of 39 patients with RNA levels (less than 2 x 10(6) Eq/L) 23 (59.0%) were responders. The genotype was determined for each patient using type-specific polymerase chain reaction (PCR) primers. There was a significant difference in rate of response between subtype 1b and subtypes 2a and 2b (P < .0002); however, all responders had less than 2 x 10(6) Eq/L independent of genotype. In a multivariate analysis, RNA level was the most statistically significant factor affecting response to IFN. Although disease severity, as defined by histological features, was not statistically correlated with nonresponse, patients that responded to IFN tended to have less severe disease.

Adult↗
PubMed1994

Isolation and characterization of human Nramp cDNA.

The mouse gene locus Lsh/Ity/Bcg regulates macrophage activation for antimicrobial activity against intracellular pathogens. A candidate gene, designated natural resistance-associated macrophage protein gene (Nramp), recently isolated from a mouse pre-B cell cDNA library, encodes an integral membrane protein that has structural homology with known prokaryotic and eukaryotic transport systems. In the present study, the cDNA for human Nramp was isolated by screening a human monocyte cDNA library. The cDNA was 2245 bp in length and coded for a protein of 483 amino acid residues with a molecular weight mass of 52.8 kDa. The deduced amino acid sequence was 89% homologous with that of mouse. Southern blot analysis indicated a single gene for Nramp counterpart in the human genome. Northern blot analysis revealed a single species of mRNA of approximately 2.5 kb.

Amino Acid Sequence↗
PubMed1994

Noninvasive localization of accessory pathways by magnetocardiographic imaging.

The magnetocardiogram (MCG) is a newly developed method that helps localize a cardiac current source. To test the clinical accuracy of a 7-channel biomagnetic system in the localization of early ventricular depolarization sites, the MCGs of 14 patients with Wolff-Parkinson-White (WPW) syndrome were recorded in a radiofrequency-shielded room. The locations of early ventricular depolarization sites were classified by standard 12-lead electrocardiograms (ECGs) and body surface isopotential mapping. The accessory pathways of 3 patients with WPW syndrome were located in the right free wall and in 11 patients in the left free wall. The three-dimensional (3-D) dipole location was computed every 2 ms from the onset of the QRS complex by the least-square method. These 3-D dipole locations were projected onto a gated magnetic resonance image in order to visualize the propagation of the calculated ventricular source. The results were compared with those obtained by body surface isopotential mapping, and electrocardiographic and electrophysiologic studies. The location of the deduced current dipole at 20 ms correlated well with the location of the accessory pathway by the body surface mappings in 12 of the 14 patients with WPW syndrome. The MCG is capable of precisely determining the 3-D location of a current source in a noninvasive manner and may be of potential benefit in the treatment of WPW syndrome by catheter ablation.

Adolescent↗
PubMed1994

Hemopneumothorax secondary to multiple cavitary metastasis in angiosarcoma of the scalp.

We report a case of hemopneumothorax secondary to multiple cavitary metastasis in the angiosarcoma of the scalp in an 86-year-old woman, who died of respiratory failure. At autopsy, multiple cavities were found in both lungs. Histologic specimen of the cavitary metastasis of the lung showed that tumor cells proliferated forming several tubular spaces and these tubular spaces seemed to communicate with the central cyst. These findings suggested that imperfect vessel-like structures of the cavitary metastasis are likely to break down and finally grow up to large thin-walled cavities.

Aged↗
PubMed1994

[Enhancement of rectal absorption of rifampicin by sodium para-aminosalicylate dihydrate in human subjects].

The suppositories of rifampicin (RFP) containing sodium para-aminosalicylate dihydrate (PAS-Na) were prepared in order to enhance the rectal absorption of RFP. By the addition of PAS-Na, the in vitro release of RFP from the suppositories was enhanced and the hardness of the suppositories decreased. The rectal absorption of RFP from the suppositories containing no PAS-Na (control suppositories) was significantly lower compared to oral administration of it (26%) in human subjects. When PAS-Na was added to the suppository (300 mg), both the area under the plasma concentration-time curve (AUC) and the maximum plasma concentration (Cmax) increased significantly compared to those of the control suppositories. The rectal absorption of PAS-Na itself from the suppositories seemed to be fast. PAS-Na might increase the absorption of RFP dissolved in the rectal fluid from the suppositories, but not affect the undissolved RFP.

Administration, Oral↗
PubMed1994

Intrafamilial clustering of genotypes of hepatitis C virus RNA.

Hepatitis C virus (HCV)-RNA in the blood was measured by polymerase chain reaction (PCR) in 37 subjects from eight families in which 2 or more persons tested seropositive for antibodies against C100-3 or CP9. HCV-RNA was positive in 17 of 37 subjects. Two or more HCV-RNA-positive subjects were observed in six of the families. Intrafamilial HCV infection was studied by determining the HCV-RNA type (I, II, III or IV) by PCR using type-specific primers. In two families, all of the subjects showed type III infection, and in three other families, all of the subjects showed type II infection, with different types of HCV infections being observed in only one family. The HCV type was uniform in all but one. These findings suggest a possibility of intrafamilial infection between husbands and wives and between members of the same household.

Adolescent↗
PubMed1994

Time- and frequency-domain analyses of signal-averaged electrocardiograms in patients with diabetes mellitus.

We recorded the signal-averaged electrocardiography (SAECG) of patients with diabetic retinopathy in order to clarify whether a ventricular conduction disturbance can be detected by time- or frequency-domain analysis of the SAECG. Twenty-four normal subjects (N group) and 20 patients with diabetic retinopathy [diabetes mellitus (DM) group] were studied. On time-domain analysis, the duration of the filtered QRS (f-QRS), the duration of the terminal QRS below 40 microV (LAS40) and the root-mean-square amplitude of the terminal 40 msec (RMS40) were measured. The frequency-domain analysis was performed using two windows. In each window, the ratio of the area under the spectral curve from 40 to 100 Hz was compared with that from 0 to 40 Hz and the area from 20 to 50 Hz was compared with that from 0 to 20 Hz. The LAS40 of the DM group was significantly prolonged when compared with the N group. The area ratio from 40 to 100 Hz versus 0 to 40 Hz significantly increased in the DM group when compared with the N group. These results suggest that SAECG can be used to detect abnormal electrical signals due to diabetic microangiopathy. Moreover, high frequency components of 40 to 100 Hz at the terminus of the QRS wave were most sensitive for abnormalities due to diabetic microangiopathy.

Aged↗
PubMed1993

Genomic organization of the mouse Lmp-2 gene and characteristic structure of its promoter.

Major histocompatibility complex (MHC) class-I molecules present antigenic peptide fragments to cytotoxic T-cells. The peptides are generated in the course of antigen processing from endogenously synthesized cytosolic proteins, and transported into the endoplasmic reticulum to associate with an MHC class-I molecule. So far, at least four genes, Lmp-2, -7, and Tap-1, -2, have been identified between the Pb and Ob genes of the mouse MHC class-II region. The genomic organization of mouse Lmp-2, a gene encoding a subunit of a large intracellular protein complex, was studied. A genomic clone has been isolated that covers the entire mouse Lmp-2 gene. We have determined the nucleotide sequence of the region encompassing the whole Lmp-2 gene and three exons of Tap-1, which spans 8 kb in the mouse genome. The two genes are situated in opposite directions. The transcription start points (tsp) of the two genes, identified by primer extension analysis, are only 118 bp apart. Both promoter regions upstream from the tsp have neither TATA consensus sequences nor other regulatory elements, like an interferon-response element, in spite of their interferon-inducible expression. The Lmp-2 sequence from a non-obese diabetic (NOD) mouse, a model animal for autoimmune diabetes, was compared with that from a Balb/c mouse.

Amino Acid Sequence↗
PubMed1993

Dyspnea sensation and chemical control of breathing in adult twins.

To examine possible genetic influence on the sensation of dyspnea and on load compensation, we conducted a twin study using healthy adult pairs (10 monozygotes, MZ, and 9 dizygotes, DZ). The ventilatory response to progressive hypercapnia (HCVR) was examined under three different conditions: hyperoxia (PETO2 > 150 mm Hg), hypoxia (PETO2 maintained at 50 to 55 mm Hg), and hyperoxia with an inspiratory flow-resistive load (17 mm H2O/L/s), with simultaneous assessment of the dyspnea sensation by visual analog scale (VAS). Although the VDZ/VMZ ratio (VMZ and VDZ are within-pair variances in MZ and DZ, respectively) for the slope value of the minute ventilation-PETCO2 regression line was not different from 1 in hyperoxia either with or without an inspiratory load, it was significantly larger than 1 in hypoxia (F = 5.17, p < 0.05), suggesting that a genetic influence on HCVR existed only in the presence of hypoxia. During 3% CO2 inhalation, the VDZ/VMZ ratio for the tidal volume (VT) was larger than 1 in hyperoxic HCVR with loading (F = 7.89, p < 0.01), and that for respiratory frequency (f) was larger than 1 only in hypoxic HCVR (F = 3.59, p < 0.05). At a PETCO2 of 55 mm Hg, the VT ratio was larger than 1 under all conditions (F = 5.91, p < 0.05; F = 6.99, p < 0.05; F = 3.75, p < 0.05; respectively), and the f ratio was significantly larger than 1 again only in hypoxic HCVR (F = 3.48, p < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

[Molecular cloning of liver/bone/kidney-type alkaline phosphatase complementary and genomic DNA: analyses of its deficiency, infantile hypophosphatasia].

Alkaline phosphatase is an enzyme present in nearly all living organisms. The liver/bone/kidney-type isozyme (ALPL) is expressed in the liver, bone, kidney and in most other tissues. We have isolated the ALPL cDNA and its gene and indicated that the gene is divided into two leader exons (exon 1B and 1L) and 11 coding exons and the liver- and bone-specific transcriptions are regulated by their own promoters. The defect of ALPL results in infantile hypophosphatasia, a disorder characterized by defective bone mineralization and subnormal activity of circulating alkaline phosphatase. Prenatal diagnoses of the disease were successfully carried out. Mutation analysis of the family member is in progress.

Adolescent↗
PubMed1993

[Efficacy of conventional CT in diagnosis of pulmonary emphysema: evaluation of low attenuation area by multiple observers].

The efficacy of conventional CT in the diagnosis of pulmonary emphysema (PE) was studied in 122 patients with miscellaneous diseases including 26 patients with PE. The density and the distribution of low attenuation area (LAA) were evaluated by six independent physicians. Analysis with kappa statistics showed a good inter-observer agreement in the detection of LAA. The grading of LAA correlated well with FEV1/FVC, DLCO/VA, and lung volumes, which indicated that PE could be detected by conventional CT by the evaluation of LAA. The agreement was poor, however, for the detection of low grade LAA and there were some false positives, and there was no specific pattern in the distribution of LAA in PE compared to other pulmonary diseases. We conclude that the evaluation of LAA by conventional CT is simple and effective in the screening of PE.

Aged↗
PubMed1992

Leukocyte adhesion deficiency: identification of novel mutations in two Japanese patients with a severe form.

Leukocyte adhesion deficiency is a disorder with mutations of the gene for the beta subunit, a component common to three adhesion molecules; LFA-1, Mac-1 and p150,95. The molecular basis of the disorder was studied in two patients with its severe form. In the first patient, the mutant gene expressed an aberrant mRNA, 1.2 kb longer than usual, resulting from a G to A substitution at the splice donor site of a 1.2 kb intron. Several aberrantly spliced messages, arising from splicing at cryptic donor sites, were also identified. The beta subunit proteins deduced from the mRNA sequences lacked half the carboxyl terminal portion. In the second patient, the mutation was a G to A transition at nucleotide 454, which resulted in an Asp128 to Asn substitution of the beta subunit. The 128th Asp residue is located in a region crucial for the association with alpha subunits and strictly conserved among the integrin beta subunits so far analyzed.

Adult↗
PubMed1992

Y-derived sequence detected in minute chromosomes by polymerase chain reaction and in situ hybridization.

A 10-year-old girl and a 10-month-old girl, both with ambiguous genitalia, were found to have 45,X/46,X,mar and 45,X/46,X,r(?) mosaicism. The marker chromosomes in both girls were very small. Polymerase chain reaction, with synthetic oligonucleotide primers from Y-specific DNA sequences pY-80 and pY53.3 containing the sex-determining region Y(SRY), proved the marker chromosomes to contain the Y short arm material. In situ hybridization with probe pY-80 confirmed that the marker chromosomes included the Y short arms. These findings, together with ambiguous genitalia in the girls, indicate that the marker chromosomes include the testis-determining factor gene.

Base Sequence↗