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K Taniguchi

Publications and source records attributed to K Taniguchi.

At least 721 records · Page 40Linked to original sources
PubMed1987

Antigenic characterization of rotaviruses isolated in Kenya from 1982 to 1983.

The electropherotypes of human rotavirus RNAs from 100 diarrheic stool specimens collected in two major districts of Kenya from 1982 to 1983 were previously reported (Y. Chiba, C. Miyazaki, Y. Makino, L. N. Mutanda, A. Kibue, E. O. Lichenga, and P. M. Tukei, J. Clin. Microbiol. 19:579-582, 1984). Of these specimens, 25 that contained rotaviruses with different RNA electropherotypes were subjected to a virus isolation experiment with MA-104 cells, and 16 rotavirus strains were isolated. The use of an enzyme-linked immunosorbent assay with subgroup-specific monoclonal antibodies enabled us to successfully subgroup 15 isolates: 4 in subgroup I and 11 in subgroup II. By fluorescent-focus-neutralization test with serotype-specific rabbit antisera, 13 isolates could be serotyped: 7 as serotype 1, 4 as serotype 2, and 2 as serotype 3. Of the remaining three isolates, F153, F247, and G402, the former was doubly neutralizable with serotype 1 and serotype 4 antisera and the latter two were neutralizable with serotype 3 and serotype 4 antisera. Detailed analysis with the antisera against F153 and F247 and four serotype-specific, VP7-directed monoclonal antibodies suggested that F153 is a serotypic mosaic strain with serotype 4-specific VP3 and serotype 1-specific VP7 outer capsid proteins and F247 and G402 are possibly antigenic mosaic strains with serotype 3 and serotype 4 antigens. On the basis of the correspondence of the rotavirus isolate serotypes determined in this study to the electropherotypes reported previously, it was inferred that serotype 1 strains were most prevalent in two districts of Kenya from 1982 to 1983, followed by any type of serotypic mosaic strains.

Antibodies, Monoclonal↗
PubMed1987

Genetic relatedness among human rotavirus genes coding for VP7, a major neutralization protein, and its application to serotype identification.

Antigenic characterization of human rotaviruses by plaque reduction neutralization assay has revealed four distinct serotypes. The outer capsid protein VP7, coded for by gene 8 or 9, is a major neutralization protein; however, studies of rotaviruses derived from genetic reassortment between two strains have confirmed that another outer capsid protein, VP3, is in some cases equally important in neutralization. In this study, the genetic relatedness of the genes coding for VP7 of human rotaviruses belonging to serotypes 1 through 4 was examined by hybridization of their denatured double-stranded genomic RNAs to labeled single-stranded mRNA probes derived from human-animal rotavirus reassortants containing only the VP7 gene of their human rotavirus parent. A high degree of homology was demonstrated between the VP7 genes of strain D and other serotype 1 human rotaviruses, strain DS-1 and other serotype 2 human rotaviruses, strain P and other serotype 3 human rotaviruses, and strain ST3 and other serotype 4 human rotaviruses. Hybrid bands could not be demonstrated between the VP7 gene of D, DS-1, P, or ST3 and the corresponding gene of human rotaviruses belonging to a different serotype. RNA specimens extracted from the stools of 15 Venezuelan children hospitalized with rotavirus diarrhea were hybridized to each of the reassortant probes representing the four human serotypes. All five viruses with short RNA patterns showed homology with the DS-1 strain VP7 gene; two of these were previously adapted to tissue culture and shown to be serotype 2 strains by tissue culture neutralization. Of the remaining 10 viruses with long RNA patterns, 2 hybridized only to the D strain VP7 gene, 6 hybridized only to the P strain VP7 gene, and 2 hybridized only to the ST3 strain VP7 gene. Hybridization using single human rotavirus gene substitution reassortants as probes may provide an alternative method for identifying the VP7 serotype of field isolates that would circumvent the need for tissue culture adaptation.

Capsid↗
PubMed1987

Cross-reactive neutralization epitopes on VP3 of human rotavirus: analysis with monoclonal antibodies and antigenic variants.

We analyzed cross-reactive neutralization epitopes on protein VP3 of human rotavirus (HRV) by the use of neutralizing monoclonal antibodies (N-MAbs), which showed a variety of interserotypic reactivity patterns when examined in a neutralization test and an enzyme-linked immunosorbent assay against 15 HRV and 2 animal RV strains. Serological study with the six cross-reactive N-MAbs revealed antigenic variations in some HRV strains within the same serotype as well as a marked antigenic difference between serotype 2 strains and serotype 1, 3, and 4 strains. Epitope analysis of the antigenic variants resistant to the six individual cross-reactive N-MAbs suggested the existence of at least three distinct cross-reactive neutralization epitopes on VP3 of HRV.

Antibodies, Monoclonal↗
PubMed1987

[Effects of antiallergic agents on polymorphonuclear leukocytes. The inhibition of arachidonic acid release and superoxide production].

The aim of this study was to examine the effects of antiallergic agents on the functions of polymorphonuclear leukocytes (PMNs) in terms of its arachidonic acid release and superoxide-anion generation. The stimulations of arachidonic acid release by formyl-methionyl-leucyl-phenylalanine (FMLP) were effectively diminished by 20 microM of azelastine as well as clemastine. Challenges of 20 microM and 50 microM of these agents inhibited approximately 50% and 100% of the arachidonic acid release, respectively. On the contrary, inhibitions of over 50% were not caused by cromoglycate, chlorpheniramine and diphenhydramine at concentrations up to 50 microM. The potency of the above examined drugs on the superoxide generations from PMNs were similar to the effects of arachidonic acid release. Ketotifen, however, showed intermediate effects indicating that a challenge of 50 microM ketotifen inhibited approximately 50% of the arachidonic acid release without having an effect on the superoxide generation. These experimental observations suggested that one of the important roles of the antiallergic agents including azelastine (known as a chemical mediator release inhibitor) and clemastine (known as a histamine H1 receptor antagonist) could be an inhibition of the first step of the arachidonic acid cascade.

Animals↗
PubMed1987

Effect of peptide bond splitting on ouabain sensitive conformational changes in Na+,K+-ATPase treated with N-[p-(2-benzimidazolyl)phenyl]maleimide.

Trypsin treatment of N-[p-(2-benzimidazolyl)phenyl]maleimide modified enzyme caused a marked reduction in Na+,K+-ATPase activity and in the amount of the alpha-chain, which contains the phosphorylation and ouabain binding sites. However, these preparations retained nearly 90% of the ouabain binding capacity and showed ouabain sensitive dynamic fluorescence changes accompanying the hydrolysis of ATP. The data showed that the three dimensional structure of Na+,K+-ATPase, which is important in the dynamic fluorescence change, is little affected in spite of extensive covalent bond splitting in the alpha-chain of Na+,K+-ATPase.

Electrophoresis, Polyacrylamide Gel↗
PubMed1987

Changes in fluorescence energy transfer between sulfhydryl fluorescent residues during ouabain sensitive Na+,K+-ATP hydrolysis.

Na+,K+-ATPase from pig kidney was sequentially modified with two different sulfhydryl fluorescent reagents, N-[p-(2-benzimidazolyl)phenyl]maleimide (BIPM) and N-[7-dimethylamino 4-coumarinyl]maleimide (DACM). The preparation thus obtained contained 3 and 2 moles of each residue in the alpha-chain. When the BIPM residues were excited at 313 nm, ouabain sensitive decrease and increase in the fluorescence intensity at not only 365 nm (BIPM fluorescence) but also 455 nm (DACM fluorescence) were observed, which were dependent on the amounts of reaction intermediates accumulated. When DACM residues were excited directly at 390 nm, only the decrease in the fluorescence intensity was observed irrespective of the intermediates accumulated. The data suggest that at least two DACM residues which differently change their microenvironments during ouabain sensitive Na+,K+-ATPase reaction are present. One is located close enough and the other is located too far to accept the energy from BIPM residue(s) in the three dimensional structure of Na+,K+-ATPase. Addition of sodium dodecyl sulfate (SDS) remarkably inhibited the energy transfer from BIPM to DACM residues. Limited proteolysis suggested that BIPM residues are located mainly in the peptides which are assumed to contain ATP binding sites and that DACM residues are located near the phosphorylation sites.

Adenosine Triphosphate↗
PubMed1987

Comparison of susceptibility of myopotential inhibition between AAI and VVI pacemakers.

Susceptibility of unipolar AAI pacemakers to myopotential inhibition (MPI) was assessed in 10 patients by provocative maneuvers and 24-hour Holter monitoring, and compared to that of unipolar VVI pacemakers in 12 patients. Five maneuvers were performed for each of four different sensitivity levels, and an MPI score of from 0-4 points was given according to the lowest sensitivity level at which MPI was provoked. The MPI score in patients with AAI pacemakers was significantly lower than that in patients with VVI pacemakers, 1.60 +/- 1.26 vs 2.83 +/- 1.03 (p less than 0.05). On Holter monitoring, no MPI was detected in any of the patients with AAI pacemakers, whereas myopotential inhibition was detected in 5/12 patients (42%) with VVI pacemakers. Intracardiac electrograms were of lower amplitudes for AAI pacing than for VVI pacing, 3.13 +/- 1.83 mV vs 11.20 +/- 5.95 mV (p less than 0.01). Although the amplitude of atrial signals was lower than that of ventricular signals, the AAI pacemakers were less susceptible to MPI than were the VVI pacemakers. However, when MPI occurs in AAI pacing, it may be more difficult to correct without undersensing because of the lower amplitude of the intracardiac signals.

Adult↗
PubMed1987

Spectral analysis of instantaneous frequency responses to sinusoidal stimulation in cutaneous mechanoreceptor afferent units of frogs.

While applying the Fast Fourier Transform to the instantaneous frequency responses to sinusoidal indentations of the cutaneous mechanoreceptor afferent units in frogs, we examined quantitatively the dynamic responses of these units. In two kinds of slowly adapting (SA) units, i.e., frog type I and frog type II units, and in rapidly adapting (RA) type I units, the instantaneous frequency responses could be reconstructed by summation of the DC component and the major 3-5 harmonics in the power spectra. In both types of SA units, the fundamental wave was the largest in power of the spectrum, but in the RA units, the 2nd harmonic was the largest. In SA units, the phase of the fundamental wave advanced by 20-55 degrees relative to the sinusoidal stimulation, but the phase of the 2nd harmonic of the RA units advanced by ca. 90 degrees. The magnitude of each component in the power spectra, especially the fundamental wave of the two SA units and the 2nd harmonics of the RA unit, increased with an increase in stimulus amplitude and frequency. The phases of the harmonics in both SA and RA types were fairly constant over varying amplitudes and frequencies of sinusoidal stimulation. The present findings indicate that both the frog type I and type II cutaneous mechanoreceptor afferent units detect both indentation magnitude and positive velocity, and that the RA type I cutaneous mechanoreceptor afferent units detect the stimulus velocity.

Action Potentials↗
PubMed1987

[A study of hepato-biliary and alimentary scintigrams using a triple tracer method].

In order to evaluate the gastric emptying and postprandial mixing of bile with food, the scintigraphies of hepatobiliary and gastrointestinal tracts by using three different kinds of radioisotopes were performed simultaneously (99mTc-E.HIDA for hepatobiliary scintigraphy, 111In-DTPA containing orange juice and 131I-albumin containing scrambled egg for gastrointestinal scintigraphy). This method was available for observation of gastric emptying of liquid and solid foods and also examination of the mixing effect of bile and food quantitatively.

Bile↗
PubMed1987

Comparison of naturally occurring poliovirus-reactive immunoglobulins in bovine and equine sera.

Bovine and equine sera were screened for poliovirus-reactive immunoglobulins (PRIgs) by means of neutralization and precipitation reactions with type 1 poliovirus. Bovine serum B1826 and B36 were found to contain such PRIgs from their reactivity to various PRIgs-resistant mutants of type 1 poliovirus origin. Neutralization and precipitation reactions with six mono-specific antibodies obtained by absorbing antiserum with each of the six different PRIgs-resistant virus mutants revealed that three antibodies were active in precipitation reaction while the others were substantially ineffective. On the basis of the results obtained and the findings reported to date, the mechanism of production of PRIgs in bovine and equine sera was discussed.

Animals↗
PubMed1987

Analysis of the effects of the Blalock-Taussig shunt on ventricular function and the prognosis in patients with single ventricle.

Twenty-four patients with single ventricle, six with single left (SLV) and 18 with single right (SRV) ventricle, who received a Blalock-Taussig (BT) shunt at an average age of 3.2 years were studied. Ventricular function was assessed angiographically by end-diastolic volume index (EDVI) and ejection fraction (EF), and attempts were made to measure ventricular mass index (VMI) and VM/EDV. In 14 patients, the preoperative and postoperative results (average 2.4 years after placement of BT shunt) were compared in SLV (n = 5) and SRV (n = 9) groups. The SLV group showed significant increases in EDVI, VMI, and VM/EDV without a significant change in EF. The SRV group showed significant increases in EDVI and VMI, while EF decreased and VM/EDV was unchanged. Late death from congestive heart failure occurred in five patients with SRV. Three patients with atrioventricular valve regurgitation suffered late death. Among the patients with SRV, the late death group had significantly lower preoperative EF and VM/EDV compared with the survivors (n = 13). All of those with a preoperative EF of less than 0.50 and a VM/EDV of less than 0.35 g/ml suffered late death. In summary, patients with SRV appear to fail to develop adaptational hypertrophy to volume loading after the BT shunt procedure, with concomitant depression in ventricular pump function. Also, late cardiac failure seems likely to develop when low EF and VM/EDV are present preoperatively.

Child, Preschool↗