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K Taniguchi

Publications and source records attributed to K Taniguchi.

At least 667 records · Page 37Linked to original sources
PubMed1988

Validity of an enzyme-linked immunosorbent assay with serotype-specific monoclonal antibodies for serotyping human rotavirus in stool specimens.

We recently developed a method for serotyping human rotavirus (HRV) by an enzyme-linked immunosorbent assay with HRV serotype-specific neutralizing monoclonal antibodies (ELISA serotyping). In the present study this method was compared with the fluorescent focus neutralization test with serotype-specific rabbit antisera (NT serotyping) in the sensitivity and specificity of the test. Direct serotyping of HRVs which were contained in stool specimens indicated that while only 37% of the samples were successfully serotyped in NT, 78% of the samples could be serotyped in ELISA. Regarding the samples whose serotype could be determined in the two tests, the assigned serotypes were identical in both tests. The results obtained indicated the utility of ELISA serotyping in clinical and epidemiologic studies of HRV infection.

Antibodies, Monoclonal↗
PubMed1988

Relative frequencies of rotavirus serotypes 1, 2, 3, and 4 in Venezuelan infants with gastroenteritis.

We have used a recently developed monoclonal antibody enzyme-linked immunosorbent assay (K. Taniguchi, T. Urasawa, Y. Morita, H. B. Greenberg, and S. Urasawa, J. Infect. Dis. 155:1159-1166, 1987) for serotyping rotaviruses recovered from 134 Venezuelan infants over a period of 15 months. One hundred and nine of the specimens were typed with the following distribution: serotype 1, 48%; serotype 2, 16%; serotype 3, 22%; and serotype 4, 14%. Three specimens reacted with two different monoclonal antibodies. In addition, 6 specimens (5%) containing enough outer capsid antigen could not be typed; partial RNA sequence analysis of the glycoprotein gene from three of these six strains failed to reveal sequence differences with prototype strains that could be serotyped with the monoclonal antibodies. Variations in the recovery rates of the different serotypes were observed. Serotypes 2, 3, and 4 predominated at the beginning of the study, and serotype 1 predominated at the end of the study. Diarrheal illness appeared to be more prolonged in infants shedding rotavirus serotypes 1 and 3 than in those shedding serotypes 2 and 4.

Base Sequence↗
PubMed1988

Comparative analysis of the VP3 gene of divergent strains of the rotaviruses simian SA11 and bovine Nebraska calf diarrhea virus.

The gene encoding outer capsid protein VP3 of subpopulations of two animal rotaviruses, simian SA11 and Nebraska calf diarrhea virus (NCDV), was analyzed. Two laboratory strains of simian SA11 rotavirus (SA11-SEM and SA11-FEM) differed with respect to VP3. This dimorphism was indicated by a difference in electrophoretic mobility and a difference in reactivity with anti-VP3 monoclonal antibodies. The overall VP3 amino acid homology between the two SA11 VP3 proteins was 82.7%, whereas the VP3 protein of SA11-FEM was 98.5% homologous in amino acid sequence to NCDV VP3, suggesting that SA11-FEM VP3 was derived by gene reassortment in the laboratory during contamination with a bovine rotavirus. A comparison of the deduced amino acid sequence of the VP3 of two virulent NCDV strains and an attenuated NCDV strain (RIT 4237), revealed only five amino acid differences which were scattered throughout the protein but did not involve the trypsin cleavage sites. Of interest, the VP3 of the standard strain of NCDV which is virulent for cows differed in only one amino acid (position 23, Gln to Lys) from the VP3 of an NCDV mutant which was attenuated both for cows and for children.

Amino Acid Sequence↗
PubMed1988

Prediction of human rotavirus serotype by nucleotide sequence analysis of the VP7 protein gene.

Human rotavirus field isolates were characterized by direct sequence analysis of the gene encoding the serotype-specific major neutralization protein (VP7). Single-stranded RNA transcripts were prepared from virus particles obtained directly from stool specimens or after two or three passages in MA-104 cells. Two regions of the gene (nucleotides 307 through 351 and 670 through 711) which had previously been shown to contain regions of sequence divergence among rotavirus serotypes were sequenced by the dideoxynucleotide method with two different synthetic oligonucleotide primers. The resulting nucleotide sequences were compared with the corresponding sequences from rotaviruses of known serotype (serotype 1, 2, 3, or 4). A total of 25 field isolates and 10 laboratory strains examined by this method exhibited marked sequence identity in both areas of the gene with the corresponding regions of 1 of the 4 reference strains. In addition, the predicted serotype from the sequence analysis correlated in each case with the serotype determined when the rotaviruses were examined by plaque reduction neutralization or reactivity with serotype-specific monoclonal antibodies. These data suggest that as a result of the high degree of sequence conservation observed among rotaviruses of the same serotype, it is possible to predict the serotype of a rotavirus isolate by direct sequence analysis of its VP7 gene.

Amino Acid Sequence↗
PubMed1988

Cross-reactive and serotype-specific neutralization epitopes on VP7 of human rotavirus: nucleotide sequence analysis of antigenic mutants selected with monoclonal antibodies.

The neutralization epitopes of human and simian rotavirus protein VP7 were studied by producing six neutralizing monoclonal antibodies (N-MAbs) and using these N-MAbs to select antigenic mutants that resisted neutralization by the N-MAbs used for their selection. Cross-neutralization tests between the N-MAbs and the antibody-selected antigenic mutants identified one cross-reactive and five distinct serotype-specific neutralization epitopes which operationally overlapped one another and constituted a single antigenic site. In addition, the amino acid substitutions in human rotavirus VP7 that are responsible for the antigenic alterations in the mutants selected with anti-VP7 cross-reactive or serotype-specific N-MAbs were identified. All the amino acid substitutions in the antigenic mutants occurred in one of two variable regions: amino acids 87 to 101 and 208 to 221.

Amino Acid Sequence↗
PubMed1988

Identification of cross-reactive and serotype 2-specific neutralization epitopes on VP3 of human rotavirus.

The group A rotaviruses are composed of at least seven serotypes. Serotype specificity is defined mainly by an outer capsid protein, VP7. In contrast, the other surface protein, VP3 (775 amino acids), appears to be associated with both serotype-specific and heterotypic immunity. To identify the cross-reactive and serotype-specific neutralization epitopes on VP3 of human rotavirus, we sequenced the VP3 gene of antigenic mutants resistant to each of seven anti-VP3 neutralizing monoclonal antibodies (N-MAbs) which exhibited heterotypic or serotype 2-specific reactivity, and we defined three distinct neutralization epitopes on VP3. The mutants sustained single amino acid substitutions at position 305, 392, 433, or 439. Amino acid position 305 was critical to epitope I, whereas amino acid position 433 was critical to epitope III. In contrast, epitope II appeared to be more dependent upon conformation and protein folding because both amino acid positions 392 and 439 appeared to be critical. These four positions clustered in a relatively limited area of VP5, the larger of the two cleavage products of VP3. At the positions where amino acid substitutions occurred, there was a correlation between amino acid sequence homology among different serotypes and the reactivity patterns of various viruses with the N-MAbs used for selection of mutants. A synthetic peptide (amino acids 296 to 313) which included the sequence of epitope I reacted with its corresponding N-MAb, suggesting that the region contains a sequential antigenic determinant. These data may prove useful in current efforts to develop vaccines against human rotavirus infection.

Amino Acid Sequence↗
PubMed1988

Sequence of the fourth gene of human rotaviruses recovered from asymptomatic or symptomatic infections.

The complete nucleotide sequence of the fourth gene of symptomatic (Wa, DS-1, P, and VA70) and asymptomatic (M37, 1076, McN13, and ST3) rotaviruses of serotype 1, 2, 3, or 4 was determined by the dideoxy chain termination method. In each strain, the fourth gene, which encodes the outer capsid protein VP3, is 2,359 base pairs in length and has 5'- and 3'-noncoding regions of 9 and 25 nucleotides, respectively. The gene has a single long open reading frame of 2,325 base pairs that is capable of coding for a protein of 775 amino acids. A total of 14 N-terminal and 12 C-terminal amino acids are completely conserved or almost completely conserved, respectively, among nine human rotavirus VP3 genes that have been sequenced. In addition, there is conservation of arginine at the two trypsin cleavage sites as well as conservation of clusters of amino acids in different regions of the two VP3 cleavage products, VP8 and VP5. Three distinct forms of VP3 were identified among the nine human rotavirus strains analyzed. Three symptomatic rotaviruses (serotypes 1, 3, and 4) possess highly related VP3 genes (92.2 to 97% nucleotide identity). Two symptomatic serotype 2 rotaviruses possess VP3 genes which are even more closely related to each other (98.6% nucleotide identity) and only moderately related to the aforementioned VP3 genes of serotypes 1, 3, and 4 (87.4 to 88.2% nucleotide identity). The four asymptomatic rotaviruses, which constitute the third group, possess highly related VP3 genes (95.5 to 97.5% nucleotide identity) which are distinct from those of the virulent rotaviruses (73 to 74.8% nucleotide identity). At 91 positions in the protein sequence of VP3, an amino acid is conserved among the asymptomatic rotaviruses, while a different amino acid is conserved among the symptomatic rotaviruses. Notably, five regions are conserved among the symptomatic rotaviruses, while a different set of sequences are conserved among the asymptomatic rotaviruses. It is possible that some or all of these regions of sequence dimorphism may be responsible for the difference in virulence of these two groups of human rotaviruses. There are 13 regions in the VP3 protein sequence which exhibit the greatest variability; the majority of these variable regions are observed between amino acids 106 to 192. These regions may represent potential antigenic sites related to heterotypic rotavirus neutralization.

Amino Acid Sequence↗
PubMed1988

Neurogenic urethra: clinical relevance of isolated neuropathic dysfunction of the urethra, and the denervation supersensitivity of the urethra revisited.

Our clinical experience on isolated neuropathic dysfunction of the urethra is presented. By discussing the urodynamic findings in neurogenic urethra, wherein the denervation supersensitivity to alpha-adrenergic stimulation in the absence of vesical denervation was a common denominator, some insight into the modern concept of motor innervation of the urethra was attempted. Our data are supportive of the current dogma implicating a significant sympathetic contribution to both autonomic and somatomotor innervation of the urethra.

Adult↗
PubMed1988

Quantitative cineangiographic analysis of ventricular volume and mass in patients with single ventricle: relation to ventricular morphologies.

With the use of biplane selective ventriculography, the ventricular volume, ejection fraction, and ventricular mass were evaluated in 28 patients with a single ventricle, and those with the left ventricular type (LV type, 12 patients) and right ventricular type (RV type, 16 patients) were compared. There were no significant differences in terms of age, hemoglobin, systemic oxygen saturation, or pulmonary-to-systemic flow ratio in the two groups. No patients with atrioventricular valve regurgitation were included. The ventricular cavity volume was calculated by the area-length method. The ventricular mass volume was determined as the shell volume created by subtracting the ventricular cavity volume from the total ventricular volume calculated by adding the free wall thickness to the chamber dimensions. The ventricular mass volume was converted to mass by multiplying by the gravity of the heart muscle. There was no significant difference between patients with the LV type and RV type of single ventricle with respect to the end-diastolic ventricular volume (188 +/- 53 and 179 +/- 61 ml/m2 in LV and RV types, respectively), end-systolic volume (88 +/- 31 and 84 +/- 27 ml/m2), or ejection fraction (0.54 +/- 0.06 and 0.52 +/- 0.06).(ABSTRACT TRUNCATED AT 250 WORDS)

Cardiac Volume↗
PubMed1988

Efficacy of a liposome preparation of anti-inflammatory steroid as an ocular drug-delivery system.

The efficacy of a liposome preparation on ocular steroid availability was investigated by both tracer studies and investigation of in vivo steroid uptake by the cornea. Dexamethasone and its ester derivatives were used as model drugs and aqueous suspensions of each served as control preparations. The liposome preparation containing dexamethasone valerate provided the highest ocular drug levels among the examined preparations. In the case of dexamethasone or dexamethasone palmitate, the liposomal form provided a lower drug level in comparison with the suspension. High esterase activity for dexamethasone valerate was observed in the corneal homogenate supernatant, and most of the steroid taken up after instillation of dexamethasone valerate was metabolized to free alcohol. The corneal dexamethasone level was almost proportional to the concentration of free dexamethasone valerate in the liposome preparation. Only the addition of stearylamine (SA) to the liposomal membrane had an added extra effect on the corneal absorption of dexamethasone valerate.

Animals↗
PubMed1988

Assessment of ocular irritability of liposome preparations.

Ocular irritability of neutral or positively charged liposomes were assessed by the Draize test, histological examination and the rabbit blinking test. The mean total score (MTS) of the Draize test showed a slight increase immediately following instillation of liposome preparations. However, it did not exceed the "practically nonirritating level", and the MTS rapidly became less than the "nonirritating level". No corneal histological alteration was observed by optical microscopy following 9 instillations of each liposome preparation. Although the neutral liposome preparation failed to increase the rabbit blinking count, the positively charged liposome preparation did so to a significant degree. The neutral liposome preparation was confirmed not to give rise to ocular irritation. However, the positively charged liposome preparation may cause pain or unpleasantness following instillation.

Animals↗
PubMed1988

Effects of Tween 80 and liposomes on the corneal permeability of anti-inflammatory steroids.

The effects of Tween 80 and liposomes on the corneal permeability of dexamethasone (DM) and dexamethasone valerate (DV) were investigated in vitro. A model based on diffusion theory could successfully be applied to analyzing the process by which DM penetrates the cornea from DM preparations. The penetration rate increased according to the concentration of free DM. Although the penetration rate was increased by pretreatment with Tween 80, it was not affected by pretreatment with liposomes. The steroid that penetrated through the cornea from DV preparations had been metabolized to DM. The transfer of DM across the cornea from DV preparations tended to slow down to some extent during the penetration process. Diffusion models were not applicable to this process, in contrast to the corneal penetration of DM from DM preparations. When liposome preparations of DV were applied, the penetration rate of DM across the cornea depended the concentration of free DV in these preparations. When DV aqueous preparations containing different concentrations of Tween 80 were applied, the penetration rate increased as the concentration of the surfactant was increased, even though the concentration of free DV in the suspensions was kept constant. These results suggest that the corneal permeability of anti-inflammatory steroids is not affected by liposomes, but is accelerated by Tween 80.

Animals↗
PubMed1988

Effects of various drugs on superoxide generation, arachidonic acid release and phospholipase A2 in polymorphonuclear leukocytes.

The effects of variety of drugs on metabolic burst and phospholipase A2 in polymorphonuclear leukocytes (PMNs) were investigated. The stimulation of PMNs by n-formyl-methionyl-leucyl-phenylalanine (FMLP) causes arachidonic acid (AA) to be released in the cells concomitantly with the generation of superoxide anion. These variables were effectively diminished with some clinically employed drugs including chlorpromazine, trifluoperazine, azelastine, clemastine and mepacrine at the lower concentration of 20 microM. In contrast, indomethacin and procaine were ineffective even at the higher concentration of 100 microM. Subcellular fractionation of PMNs revealed that phospholipase A2 activity was located both in the plasma membrane-rich fraction as well as the granule-microsome-rich fraction, and the potency of inhibition of membrane-bound phospholipase A2 by the above mentioned drugs was: indomethacin (IC50 = 3 microM) less than chlorpromazine less than azelastine and clemastine (IC50 greater than 100 microM). The low potency of antipsychotropic drugs and antihistaminic drugs in inhibiting the fractionated phospholipase A2 contrast with the high efficiency with which they inhibit the superoxide generation and the AA release from stimulated PMNs. The AA releases from the PMNs stimulated by FMLP or calcium ionophore (A23187) were almost equally diminished by various drugs at the lower concentration. From these observations, it appeared likely that these drugs might inhibit the metabolic stimulations of PMNs at the sites of the Ca2+-dependent activation processes of the enzymes responsible for the AA release and the superoxide generation.

Animals↗
PubMed1988

Diagnostic accuracy of continuous wave Doppler echocardiography in severe aortic stenosis in the elderly.

Forty-four male patients (mean age 63.6 years) with aortic stenosis (AS) were evaluated by conventional hemodynamic methods and continuous wave (CW) Doppler echocardiography. The relationship between Doppler mean gradients and direct mean pressure gradients in all patients was significant, with an r value of 0.88. Sixteen of 17 patients with a mean Doppler gradient greater than or equal to 40 mmHg had severe AS (AVA less than or equal to 1.0 cm2). Twenty-seven patients had a Doppler gradient less than 40 mmHg, and 8 of these patients had severe AS (AVA less than or equal to 1.0 cm2). The sensitivity and specificity of a Doppler gradient greater than or equal to 40 mmHg in detecting severe AS were, therefore, 67% and 95%, respectively. Thirty-three percent (8/24) of patients with severe AS and low Doppler gradients (less than 40 mmHg) had evidence of poor left ventricular function, evidenced by a lower cardiac output, a higher heart rate and an abnormal PEP/LVET ratio compared to the other patients. Thus, the presence of a low stroke volume less than or equal to 60 ml/beat and PEP/LVET x HR greater than 26 is of value in identifying patients where the Doppler is likely to significantly underestimate the degree of aortic stenosis.

Adult↗
PubMed1988

The effects of antianginal drugs on left ventricular function in patients with effort angina pectoris. Comparison among isosorbide dinitrate, nifedipine and propranolol by PANOVA.

To study the acute effects of ISDN, nifedipine, propranolol and placebo on cardiac function in patients with myocardial ischemia and to characterize their hemodynamic effects by PANOVA, we repetitively performed exercise radionuclide angiography (RNA) following random assignment of each drug in 20 patients with effort angina pectoris. We obtained exercise response curves of hemodynamic parameters determined by RNA. ANOVA was performed to analyze the sizes (average height) of those response curves, and PANOVA (principal component analysis, PCA, combined with ANOVA) to analyze differences in the profiles (patterns) of the curves. By conventional analysis of variance followed by a Scheffé type multiple comparison, end-diastolic volume after ISDN, which was significantly smaller than those after the other drugs at rest (p less than 0.01), was similar to those after nifedipine and propranolol during exercise (96.4 +/- 4.6 ml/m2 vs. 94.8 +/- 5.1 ml/m2 and 97.1 +/- 4.9 ml/m2, respectively). Systemic vascular resistance after nifedipine, which was also significantly lower than those after the other drugs at rest (p less than 0.05), was not different from that after placebo during exercise (16.9 +/- 1.1 units vs. 18.7 +/- 1.3 units). Thus, this analysis was considered insufficient to fully differentiate the characteristics of each drug. By PANOVA, the profiles of LVEF with these three antianginal drugs were similar, and significantly differentiated from that of placebo (p less than 0.05). This indicated that the antianginal effect could be represented by the profiles of the response curves of LVEF, using PANOVA. Evaluating the underlying hemodynamic mechanisms of these drugs by PANOVA, ISDN was significantly differentiated from nifedipine and propranolol by the profile of end-diastolic volume (p less than 0.05). The characteristics of nifedipine were clearly demonstrated by the size and profile of systemic vascular resistance, and those of propranolol were also differentiated by the size and profile of the double product and P-V index. Hence, it is concluded that with the aid of PANOVA, the changes in hemodynamic parameters during ischemia can be evaluated in a manner that is highly effective in differentiating the characteristics of the effects of antianginal drugs in patients with angina pectoris.

Aged↗
PubMed1988

Hemodynamic studies of nitroglycerin in dogs using an open loop method.

Nitroglycerin is considered to decrease both preload and afterload. To elucidate the actions of nitroglycerin on afterload, venous return was kept constant in this experiment. Three different doses of nitroglycerin, 0.3 microgram/kg/min, 1.0 microgram/kg/min, 3.0 micrograms/kg/min were administered into the ascending aorta of 6 mongrel dogs weighing over 20 kg. These doses of nitroglycerin were randomized in each of six procedures. The plasma concentration of nitroglycerin increased during 10 min of infusion, then it decreased exponentially. Heart rate, cardiac output and left atrial pressure did not change significantly at any dose of nitroglycerin. Systolic blood pressure and systemic vascular resistance (as indices of afterload) decreased significantly during nitroglycerin infusion, especially with the 3 micrograms/kg/min dose. These data suggest that nitroglycerin decreases the afterload. The effects appeared rapidly with administration and disappeared rapidly after cessation of the infusion.

Animals↗
PubMed1988

DIDMOAD (diabetes insipidus, diabetes mellitus, optic atrophy and deafness) syndrome associated with myocardial disease.

A 30 year old man with DIDMOAD (diabetes insipidus, diabetes mellitus, optic atrophy and deafness) syndrome associated with myocardial disease is reported. Echocardiographic study revealed a marked symmetric left ventricular hypertrophy. Histology of the endomyocardial biopsy specimen from the right ventricle showed severe glycogen deposition in the myocytes. This case may indicate that DIDMOAD syndrome is a hereditary systemic disease affecting multiple organs, including the myocardium.

Adult↗