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Biomedical subjects

K Taniguchi

Publications and source records attributed to K Taniguchi.

At least 379 records · Page 21Linked to original sources
PubMed1995

Inverted impaction of second premolar: two case reports.

This report documents two patients with inversion and impaction of the second premolar tooth. Family and personal histories of both patients were unremarkable with no abnormalities in general growth and development nor any history of trauma. Patient 1 was a 10-year-old female with inversion and impaction of the mandibular right second premolar. Fifteen months previously, pre-operative radiographic examination prior to extraction of the mandibular right second primary molar revealed a normal direction and eruptive pattern of the tooth in question. However, following extraction of the mandibular right second primary molar, the developing succedaneous premolar was seen to be inverted. This was suggestive of inversion resulting from an iatrogenic force during tooth extraction. The second patient was a 9-year-old male with inversion and impaction of the maxillary right second premolar. Radiographic examination 3 months prior to the initial visit at our hospital showed an existing inversion of this tooth. This pointed to a developmental abnormality in the location of the original tooth bud.

Bicuspid↗
PubMed1995

The effects of imipramine, amitriptyline and clonidine administered by iontophoresis on the pain threshold.

We performed iontophoresis of aqueous solution of imipramine and amitriptyline, tricyclic antidepressant, and clonidine, an alpha 2 agonist, in a total of 30 healthy adult volunteers. Analgesic effects were compared among the 3 drugs by measurement of the pain threshold using a thermopainmeter. No significant changes in the pain threshold were observed with imipramine or amitriptyline. On the other hand, clonidine significantly increased the pain threshold, compared with the control value before iontophoresis. Although the effects of iontophoresis of clonidine were smaller than the previously reported effects of iontophoresis with other drugs, these effects seemed to be due to the action of clonidine itself not associated with electric stimulation. More marked effects may be obtained with changes in the conditions of iontophoresis.

Adrenergic alpha-Agonists↗
PubMed1995

The effect of calcium channel antagonist administered by iontophoresis on the pain threshold.

Three calcium (Ca) channel antagonists were administered to healthy adult volunteers by iontophoresis alone or in combination with lidocaine to study their effects on the pain threshold. Nicardipine, verapamil or diltiazem administered alone elevated the pain threshold to the same degree as lidocaine. When Ca channel antagonists were administered in combination with lidocaine, the pain threshold elevation was not changed, but the duration of the analgesic action was prolonged when compared with lidocaine alone. These results suggest a role of the calcium channel in the pain control mechanism and the possible clinical application of Ca channel antagonists delivered by iontophoresis in pain management.

Adult↗
PubMed1994

Possible involvement of multidrug-resistance-associated protein (MRP) gene expression in spontaneous drug resistance to vincristine, etoposide and adriamycin in human glioma cells.

The multidrug-resistance phenotype in human tumors is partly associated with over-expression of the 170 kDa-P-glycoprotein encoded by the multidrug-resistance-1 (MDR1) gene. Another related, but non-P-glycoprotein, multidrug-resistance-associated protein (MRP) gene encodes a 190 kDa-membrane ATP-binding protein. Glioblastoma multiforme is a highly malignant primary neoplasm of the central nervous system which is refractory to anti-cancer chemotherapy, but the mechanism underlying this drug resistance is unknown. Out of glioma cell lines, 2, namely IN500 and T98G, which had elevated MRP mRNA levels, showed the highest resistance to multiple anti-cancer agents such as etoposide, vincristine and adriamycin, and decreased intracellular accumulation of etoposide. In the remaining 5 cell lines, various degrees of sensitivity to adriamycin and etoposide appeared to correlate with their respective MRP mRNA levels. Our study proposes that MRP may be involved in spontaneous multidrug resistance in human gliomas.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1994

Species specificity and interspecies relatedness in VP4 genotypes demonstrated by VP4 sequence analysis of equine, feline, and canine rotavirus strains.

We determined the nucleotide and deduced amino acid sequences of the VP4 genes of five equine, two feline, and two canine rotavirus strains. A high degree of homology (> 97.0%) was found among the VP4 amino acid sequences of the equine strains H2, FI-14, and FI23. Equine strain L338 has a distinct VP4 amino acid sequence from those of the other equine strains (78.1% or less homology), and the L338 VP4 exhibited more than 17.0% divergence at the amino acid level from those of rotavirus strains published so far. The VP4 amino acid sequence of equine strain H1, which showed low homology with those of other equine strains, shares > 95.4% homology to those of porcine strains OSU and YM. VP4 amino acid sequences of feline strain Cat97 and canine strains CU-1 and K9 showed a high degree of homology (96.8 to 97.2%) to one another, and were found to be quite similar (96.0-97.0% homology) to that of a human HCR3 strain recently characterized. Feline strain Cat2, whose VP4 sequence is distinct from that of strain Cat97, has a VP4 similar to those of human strains K8 and AU-1 (97.8 and 97.5% homologies at amino acid level, respectively). Thus, the VP4 sequences of rotaviruses showed species specificity and interspecies relatedness.

Amino Acid Sequence↗
PubMed1994

Pyridoxal 5'-phosphate probes at Lys-480 can sense the binding of ATP and the formation of phosphoenzymes in Na+,K(+)-ATPase.

The Lys-480 in the alpha-subunits of Na+,K(+)-ATPase from pig kidneys was specifically modified with pyridoxal 5'-phosphate (PLP) or pyridoxal 5'-diphospho-5'-adenosine (AP2PL) probes in the presence of NaCl. The site was shown to be the same as the ATP-protectable binding of these probes (Hinz, H.R., and Kirley, T.L. (1990) J. Biol. Chem. 265, 10260-10265). Modifications strongly reduced both Na+,K(+)-ATPase activity and the amount of Na(+)-dependent phosphoenzyme from [32P]ATP but not from [32P]acetyl-phosphate (AcP). Addition of AcP to the enzyme induced a slight decrease in the fluorescence of the PLP probe in the presence of 2 M NaCl and 4 mM MgCl2 but a single exponential increase in the presence of 16 mM NaCl and 4 mM MgCl2. The addition of ATP induced single exponential fluorescence increases at both Na+ concentrations. The data show that these probes can sense molecular events related to the formation of phosphoenzymes induced by AcP and presumably to the formation of Mg-Na-ATP-enzyme complex. The data also suggest that PLP or AP2PL probes at Lys-480 in the presence of Na+ and Mg2+ do not affect the transphosphorylation from AcP to Asp-369 to form phosphoenzymes but that they inhibit the transphosphorylation from the gamma-phosphoryl group of ATP and also ATP binding in the absence of Mg2+.

Adenosine Triphosphate↗
PubMed1994

Treatment of hepatocellular carcinoma with transcatheter arterial embolization. Analysis of prognostic factors.

BACKGROUND: Transcatheter arterial embolization (TAE) is a useful treatment modality for hepatocellular carcinoma (HCC). To study the prognostic factors, survival time of patients with HCC after TAE was analyzed retrospectively using clinical manifestations of coexisting liver cirrhosis and clinical features of HCC. METHODS: Eighty-seven patients with HCC were treated with TAE between 1984 and 1991 and observed at Nagasaki University Hospital. All the patients also had liver cirrhosis. RESULTS: The survival time of the 87 patients after TAE ranged from 2 months to 8.1 years (mean +/- standard deviation, 2.7 +/- 0.3 years). Survival curves after TAE did not differ between men and women (P > 0.5) or between hepatitis B and C viral infection (P > 0.8), but they depended on clinical stages of coexisting liver cirrhosis (P < 0.01). The cumulative survival after TAE was significantly longer in patients with uninodular tumors than in patients with multinodular tumors (P < 0.0001) (3-year survival, 53.3% vs. 13.3%; 5-year survival, 32.2% vs. 3.3%, respectively). In contrast, patients' survival time was not associated with the size of the tumor detected at the time of treatment with TAE (P > 0.1). CONCLUSIONS: Treatment of HCC with TAE is well indicated regardless of tumor size for patients with nonadvanced liver cirrhosis and uninodular tumors. Alternatively, treatment of HCC with TAE alone is still insufficient in patients with multinodular tumors. Other treatment modalities in combination with TAE should be considered to achieve a more favorable prognosis of these patients.

Adult↗
PubMed1994

Relation of impaired left ventricular function in mitral regurgitation to left ventricular contractile state after mitral valve replacement.

To reevaluate the postoperative contractile state and survival, 34 patients (19 men and 15 women; average age 45 years, range 23 to 65) undergoing conventional mitral valve replacement between 1980 and 1990 were studied. There were 5 cardiac deaths (2 early and 3 late). Four of 5 deaths occurred in patients who had a preoperative left ventricular end-systolic volume index > 100 ml/m2. Sixteen patients with an end-systolic volume index < 100 ml/m2 (group I), and 5 with an index > 100 ml/m2 (group II) underwent repeat catheterization 8 months (range 4 to 17) after surgery. The ratio of end-systolic wall stress to end-systolic volume index increased significantly after surgery in group I, whereas it remained reduced in group II. The postoperative end-systolic wall stress/volume index ratio correlated significantly with the preoperative end-systolic volume index (p < 0.001). In the relation between end-systolic wall stress and ejection fraction, all patients in group II had values that were less than the 95% confidence limits for the normal relation. In conclusion, patients with a preoperative end-systolic volume index > 100 ml/m2 appeared to be at high risk of incurring irreversible depressed myocardial contractility, with a high postoperative mortality.

Adult↗
PubMed1994

Antitumor effect of neocarzinostatin conjugated to human/mouse chimeric Fab fragments of the monoclonal antibody A7 on human pancreatic carcinoma.

The anticancer agent neocarzinostatin (NCS) was bound covalently to human/mouse chimeric Fab fragments of the monoclonal antibody A7 to form the conjugate chA7Fab-NCS. The antitumor effect of chA7Fab-NCS was tested by measuring the inhibition of 3H-thymidine incorporation into human pancreatic carcinoma cells. The chA7Fab-NCS was approximately 2.3 times as effective as free NCS against human pancreatic carcinoma cells which reacted with the monoclonal antibody A7. The antitumor activity of chA7Fab-NCS was inhibited by excess chA7Fab. ChA7Fab-NCS had an antitumor effect equivalent to free NCS on human pancreatic carcinoma cells which did not react with the monoclonal antibody A7. ChA7Fab-NCS appears to be a potentially useful conjugate for immunotargeting chemotherapy against pancreatic carcinoma.

Animals↗
PubMed1994

Differences in plaque size and VP4 sequence found in SA11 virus clones having simian authentic VP4.

We isolated five stable SA11 clones (TN-S1, TN-S2, TN-L1, TN-L2, and BN-S4) with different plaque sizes from two SA11 stocks. In polyacrylamide gel electrophoresis, the mobilities of the fourth, fifth, and seventh RNA segments of SA11 clones with large plaque size (TN-L1 and TN-L2) were faster than those of clones with small plaque size (TN-S1, TN-S2, and BN-S4). Nucleotide sequence determination of the fourth RNA segment identified a five-amino-acid difference in VP4s between the clones with large and small plaque sizes. The VP4 sequences of two clones with small plaque size (TN-S1 and BN-S4) were the same as the sequence of SA11-SEM reported by K. Nishikawa et al. (1988, J. Virol. 62, 4022-4026), while the VP4 sequences of the clones with large plaque size (TN-L1 and TN-L2) were similar, but not identical, to that reported by D. B. Mitchell and G. W. Both (1989, Nucleic Acids Res., 17, 2122). A single-gene reassortant, K8-L2.4, in which RNA segment 4 was derived from clone TN-L2 of SA11 virus and the other RNA segments were from strain K8, produced large plaques like TN-L2, suggesting that the five-amino-acid difference in VP4 between the clones with large and small plaque sizes might be associated with the difference in plaque size.

Animals↗
PubMed1994

Changes of monosaccharide availability of human hybridoma lead to alteration of biological properties of human monoclonal antibody.

The effect of glucose and other monosaccharide availability in culture medium on production of antibody by human hybridomas has been studied. Human hybridoma cells C5TN produce an anti lung cancer human monoclonal antibody, and the light chain is N-glycosylated at the variable region. When the cell line was grown in the presence of various concentrations of glucose, the antibodies produced changed their antigen-binding activities. Analysis of the light chains produced under these condition revealed that four molecular-mass variant light chains ranging from about 26 to 32 kDa were secreted. The twenty six-kDa species, which corresponds to a non-glycosylated form of the light chain, was recovered after enzymatic removal of all N-linked carbohydrate chains, indicating that the source of the heterogeneity of the light chain is due to the varied glycosylation. When the C5TN cells were cultured in medium containing either fructose, mannose or galactose instead of glucose, galactose elevated the antigen binding activity of the antibody more than the other sugars. These results suggest that change of glucose availability affects the antigen-binding activity of the antibody via the alteration of the glycosylation.

Antibodies, Monoclonal↗
PubMed1994

Noninvasive assessment of cardiac contractility by using (dP/dt)/P of carotid artery pulses during exercise.

In earlier studies we have shown that both the pressure (P) of the carotid artery pulse (CAP) and its first derivative (CAP dP/dt) could be recorded during moderate exercise. To establish that the CAP (dP/dt)/P is a noninvasive substitute for the left ventricular (LV) value, LV (dP/dt)/P, an index of cardiac contractility, we studied CAP (dP/dt)/P under various states of activity in the autonomic nervous system in 12 healthy male subjects. Increased sympathetic nerve activities yielded by passive tilting, emotional load, or cold stress increased CAP (dP/dt)/P significantly (P < 0.05). Increased parasympathetic nerve activity by ocular compression, however, did not significantly affect the value. Moderate exercise at a heart rate of approximately 150 beats.min-1 increased it significantly from 16.7 to 25.2.s-1 in a supine position (P < 0.001) and from 16.6 to 24.8.s-1 in an upright position (P < 0.001). It increased monotonically as heart rate increased, but the slope was steeper when the heart rate was greater than approximately 100 beats.min-1 than it was when the rate was less than 100 beats.min-1. In conclusion, the present study indicated that CAP (dP/dt)/P can be used as a noninvasive index of cardiac contractility even in moderate exercise.

Adult↗
PubMed1994

Nefiracetam enhances acetylcholine outflow from the frontal cortex: in vivo microdialysis study in the rat.

The effects of nefiracetam [DM-9384; N-(2, 6-dimethylphenyl)-2-(2-oxo-1-pyrrolidinyl)acetamide], a cognitive enhancer, on extracellular acetylcholine and glutamic acid in the frontal cortex were studied using brain microdialysis in freely moving rats. Nefiracetam administration (1 mg/kg, p.o.) doubled the amount of acetylcholine in the dialysate. When tetrodotoxin was added to the perfusion solution, the basal level of acetylcholine decreased and nefiracetam caused no increase in acetylcholine outflow. The amount of glutamic acid in the dialysates was not affected by nefiracetam. These results suggest that nefiracetam increases the amount of acetylcholine within the cholinergic synaptic clefts.

Acetylcholine↗
PubMed1994

Effect of the selection pressure with anti-VP7 and anti-VP4 neutralizing monoclonal antibodies on reassortant formation between two human rotaviruses.

In order to study the effect of selection pressure of anti-VP4 and anti-VP7 neutralizing monoclonal antibodies(N-MAbs) on reassortant formation, 424 reassortant clones were produced from mixed cultures of human rotavirus strains Wa and HN126 and their genotypes were analysed. Reassortant selection was done with four types of N-MAb: anti-VP4 MAb to Wa and anti-VP7 MAb to HN126(selection A); anti-VP4 MAb to HN126 and anti-VP7 MAb to Wa(selection B); anti-VP7 MAb to Wa(selection C); and anti-VP4 MAb to Wa(selection D). In each selection experiment, more than 100 clones were isolated, and the parental origin of RNA segments was identified by polyacrylamide gel electrophoresis. All clones isolated by selections A and B were found to be antigenic mosaic reassortants with the VP4 gene of HN126 and the VP7 gene of Wa and antigenic mosaic reassortants with the VP4 gene of Wa and the VP7 gene of HN126, respectively. Although in reassortants of both selections, RNA segments 2, 3, 5 and 6 were selected from strain Wa at considerably high rates, selection rates of RNA segments 1, 7, 8, and 11 were significantly different between selection A and B. In reassortants from selection C and D, selection rates of RNA segments 1, 3, 6, 7, 8, and 11 from Wa were significantly lower than those in selection A and B, whereas RNA segments 2 and 5 were almost exclusively selected from Wa as observed in selection A and B. These results indicated the presence of two types of nonrandom gene selection in reassortant formation, one strongly dependent on, and another irrespective of, the selection pressure with N-MAbs.

Antibodies, Monoclonal↗
PubMed1994

Changes in left ventricular performance after global ischemia: assessing LV pressure-volume relationship.

To determine the effect of ischemia and reperfusion on left ventricular systolic function, we studied the ischemia-induced rightward shift of the ventricular pressure-volume relationship. Eight mongrel dogs were intubated, and their hearts were exposed through a thoracotomy. A conductance catheter and micromanometer were used to obtain instantaneous left ventricular pressure-volume data. The dogs were subjected to 20 minutes of normothermic global myocardial ischemia, followed by 80 minutes of reperfusion under total cardiopulmonary bypass. Data were acquired during transient (10- to 12-second) periods of acute volume loading before ischemia and at 20-minute intervals during reperfusion as bypass was continued. The relationship between stroke work and end-diastolic volume (ie, preload recruitable stroke work [PRSW]) and the end-systolic pressure-volume relationship were highly linear throughout the study (mean r = 0.954 to 0.983 for PRSW; mean r = 0.954 to 0.984 for end-systolic pressure-volume relationship). Ischemia produced changes in the PRSW: (1) the slope decreased significantly at 20 minutes and 40 minutes of reperfusion then returned to preischemic levels at 60 minutes and 80 minutes, and (2) the x-intercept increased significantly up to 60 minutes. The preload recruitable work area (the area under the linear regression line of PRSW) reflected changes in both slope and x-intercept of PRSW and was significantly decreased throughout the 80 minutes of reperfusion despite gradual recovery. The slope and the x-intercept of the end-systolic pressure-volume relationship did not change after ischemia.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

Ultrastructure of the neuromuscular junction of vasomotor nerves in the microvasculature of human dental pulp.

Vasomotor nerves in human dental pulp were more closely related to arterioles than to venules. Most were composed of unmyelinated fibres, which were mainly adrenergic. They appeared close to arterioles that were surrounded by a few layers of contractile smooth-muscle cells. The smaller arterioles with a diameter of 10-15 microns received a more intimate innervation by vasomotor nerves than did the larger. These vessels occasionally showed much narrower neuromuscular junctions than previously reported. Most of these nerve fibres were identified as adrenergic by the presence of chromaffin-positive synaptic vesicles detected by ultrastructural enzyme histochemistry. Their function appeared to be to regulate the blood flow and/or the blood pressure by stimulating smooth-muscle cells, resulting in contraction and a change in the calibre of the vessels. Capillaries and venules, which have a higher permeability, received weaker innervation by the vasomotor nerves than did arterioles. The intimate relation between vasomotor nerves and arterioles is related to the function of dental pulp in normal and pathological conditions.

Adrenergic Fibers↗