Search PubMed⌕ Search

Biomedical subjects

M Takeyama

Publications and source records attributed to M Takeyama.

At least 73 records · Page 4Linked to original sources
PubMed1994

Enzyme immunoassay of motilin in human plasma.

A sensitive and specific double-antibody enzyme-linked immunoassay (EIA) for detecting a motilin-like immunoreactive substance (M-IS) in human plasma has been developed. In competitive reactions, the motilin antibody was incubated with a plasma sample (or motilin standard) and beta-D-galactosidase-linked synthetic motilin. Free and antibody-bound enzymes were separated using an anti-rabbit IgG-coated immunoplate. Enzyme activity on the plate was determined by fluorophotometric analysis. This immunoassay allows the detection of 20 to 200 fmol/ml (54 to 540 pg/ml) of motilin. The mean level of M-IS detected in human plasma was 53.9 +/- 25.6 pg/ml.

Adult↗
PubMed1994

In vivo binding characteristics of carbamazepine and carbamazepine 10, 11-epoxide to serum proteins in monotherapy adult patients.

The in vivo serum protein binding characteristics of carbamazepine and carbamazepine 10, 11-epoxide, which was the main metabolite of carbamazepine in plasma, were assessed in sera from 30 adult patients with epilepsy on carbamazepine monotherapy. The binding characteristics of each compound were analyzed according to the two-site binding model. Association constants to the high-affinity binding site on alpha 1-acid glycoprotein (AAG) were 0.053 l/mumol for carbamazepine and 0.013 l/mumol for carbamazepine 10, 11-epoxide. The maximum binding capacities for drug-AAG binding were 49.2 mumol/l for carbamazepine and 48.1 mumol/l for carbamazepine-10, 11-epoxide. The products of the association constant and binding capacity for the lower-affinity site (i.e., the linear component of albumin binding site) were 1.273 for carbamazepine and 0.525 for carbamazepine 10, 11-epoxide. Within the total concentration range of each compound investigated, the contribution of drug-AAG binding to the total serum binding was relatively larger than that of drug-albumin binding.

Adolescent↗
PubMed1993

Determination of human immunoglobulin A and secretory immunoglobulin A in bronchoalveolar lavage fluids by solid phase enzyme immunoassay.

Solid phase enzyme immunoassay methods for the determination of secretory immunoglobulin A (IgA) and the total amount of serum and secretory IgA in bronchoalveolar lavage fluids (BALF) were developed. The solid phase was prepared by immobilizing rabbit anti-human IgA. Horseradish peroxidase-conjugated goat anti-secretory component or horseradish peroxidase-conjugated goat anti-human IgA (Fc) were used as labeled antibodies. The minimum detectable amounts of secretory IgA and total IgA were 2 and 0.5 ng/well, respectively. These assay methods were successfully applied to the determination of secretory and total IgA levels in BALF samples obtained from 44 subjects including healthy non-smokers, smokers and patients with the following lung diseases: idiopathic pulmonary fibrosis, sarcoidosis and hypersensitivity pneumonitis. The secretory and total IgA levels in BALF collected from healthy non-smokers (n = 9) were 10.5 +/- 3.6 and 25.4 +/- 15.5 (S.D.) micrograms/ml, respectively. In healthy smokers, the secretory IgA concentration was significantly decreased and in idiopathic pulmonary fibrosis, the total IgA was increased. These results indicate that the quantitation of secretory and total IgA may be useful for the investigation of lung disease.

Bronchoalveolar Lavage Fluid↗
PubMed1993

In vivo determinations of carbamazepine and carbamazepine-10, 11-epoxide binding parameters to serum proteins in monotherapy patients.

The in vivo serum protein binding parameters of carbamazepine (CBZ) and carbamazepine-10, 11-epoxide (CBZ-E), which was the main metabolite of CBZ in plasma, were determined in sera from 27 patients on CBZ monotherapy. Based on the results by recent studies, the authors assumed that CBZ and CBZ-E binding to serum proteins were composed of specific binding sites on alpha 1-acid glycoprotein (AAG) and albumin. Therefore, the authors determined the binding parameters of each compound by specific binding equation for two proteins. Association constants for drug-AAG binding were .071 L/mumol for CBZ and .016 L/mumol for CBZ-E. Conversely, those for drug-albumin binding were .00052 L/mumol for CBZ and .00072 L/mumol for CBZ-E. Within the investigated total concentration ranges in each compound, the AAG binding contributes largely to the drug-serum protein interactions. Furthermore, our results indicate that the albumin binding contributes to the nonsaturable serum protein binding of these compounds in the therapeutic range.

Adolescent↗
PubMed1993

Effect of unbound clearance on binding parameters of valproic acid to serum proteins.

Nine healthy subjects received 400 mg sodium valproate orally in the fasting state. Binding parameters of valproic acid to serum proteins were determined by Scatchard analysis for individual series of valproic acid data. Total and unbound (intrinsic) clearances (CLt and CLu) were calculated by dividing the dose by the appropriate area under the serum drug concentration-time curve. Unbound clearance correlated positively with the product of association constant (Ka) and concentration of free protein ((P)) (P < .05). Conversely, no significant correlation was found between CLt and binding parameters. The average unbound concentration correlated negatively with both CLu and ka(P) values. The result indicates an effect of CLu on Ka(P) value of valproic acid.

Administration, Oral↗
PubMed1993

In vivo binding characteristics of carbamazepine and carbamazepine-10,11-epoxide to serum proteins in paediatric patients with epilepsy.

The in vivo serum protein binding characteristics of carbamazepine (CBZ) and carbamazepine-10,11-epoxide (CBZ-E) were assessed in sera from 23 paediatric patients on CBZ monotherapy. We assumed that CBZ and CBZ-E binding to serum proteins comprised specific binding sites on alpha 1-acid glycoprotein (AAG) and non-specific binding sites on serum albumin. Therefore, the binding characteristics of each compound were analysed according to specific and nonspecific binding equations. Association constants for drug-AAG binding were 0.096 l.mumol-1 for CBZ and 0.023 l.mumol-1 for CBZ-E. Within the concentration ranges investigated the specific binding of each compound contributes to the drug-serum protein interactions. Age did not show a significant correlation with the serum unbound fraction of each compound.

Adolescent↗
PubMed1993

Substance P and vasoactive intestinal peptide in nasal secretions and plasma from patients with nasal allergy.

To clarify the role of substance P (SP) and vasoactive intestinal peptide (VIP) in nasal allergy, we measured their concentrations in the nasal secretions and plasma of normal subjects and patients with nasal allergy to house dust and Japanese cedar pollen by competitive enzyme-linked immunoassay. The mean levels of SP (224 pmol/L) and VIP (41.6 pmol/L) in the nasal secretions of normal subjects were significantly higher than those in plasma (SP 3.04 pmol/L and VIP 1.04 pmol/L; p < .01). The mean levels of SP and VIP in the nasal secretions of the pollinosis group were significantly higher than those of the control group (p < .05 and p < .01), while the levels of the house dust allergy group were not higher than those of the control group. Intranasal allergen challenge significantly reduced SP levels in the nasal secretions of the allergy groups, while it did not influence VIP levels in the nasal secretions. These findings suggest that SP and VIP are actively secreted into the nose and may play an important role in the allergic reaction on the surface of the human nasal mucosa.

Adolescent↗
PubMed1993

Enzyme immunoassay of gastrin in human plasma.

A sensitive and specific double-antibody enzyme immunoassay (EIA) for a gastrin-like immunoreactive substance (G-IS) in human plasma was developed. For competitive reactions, the gastrin antibody was incubated with gastrin standard (or sample) and beta-D-galactosidase labeled synthetic C-terminal gastrin I fragment (residue 2-17). Free and antibody-bound enzyme hapten were separated using an anti-rabbit IgG coated immunoplate. Activity of the enzyme on the plate was fluorometrically determined. The present immunoassay allows detection of 1 to 20 fmol/ml (2.1 to 42 pg/ml) of gastrin. The levels of G-IS determined in human plasma were 7.8 +/- 1.6 pg/ml before lunch and 26.4 +/- 8.4 pg/ml after lunch.

Amino Acid Sequence↗
PubMed1993

Decreases in substance P and vasoactive intestinal peptide concentrations in plasma of stroke-prone spontaneously hypertensive rats.

In order to study alterations of peripheral substance P (SP) and vasoactive intestinal peptide (VIP) in the immunoreactive nervous system in essential hypertension, plasma SP and VIP concentrations in stroke-prone spontaneously hypertensive rats (SHRSP) at 8, 12, 18, 28, 30, 35 and 48 weeks of age and age-matched Wistar-Kyoto rats (WKY) were measured, using enzyme immunoassays (EIAs). The mean plasma SP concentrations of SHRSP (n = 61) and WKY (n = 58) were 4.9 +/- 1.2 fmol/ml and 6.6 +/- 1.9 fmol/ml, respectively. The value of SHRSP was significantly lower than that of WKY (p < 0.01). The mean SP concentration of young SHRSP was significantly higher than those of other ages. The mean plasma VIP concentrations of SHRSP (n = 61) and WKY (n = 58) were 0.80 +/- 0.25 fmol/ml and 1.01 +/- 0.32 fmol/ml, respectively. The value of SHRSP was significantly lower than that of WKY (p < 0.01). These decreases in plasma SP and VIP concentrations of SHRSP were observed at all ages. Decreases in the peripheral release of SP and VIP from the endings of SP- and VIP-immunoreactive nerves of SHRSP were seen, and the functional involution of peripheral SP- and VIP-immunoreactive nerves in essential hypertension was suggested.

Animals↗
PubMed1993

[Relationship between tissue concentrations of 5-FU and degeneration of tissues after UFT administration in patients with bladder tumor].

The relationship between the 5-FU concentration and tissue degeneration was studied in the bladder tumor tissue after UFT administration. In 12 patients with bladder tumor, UFT 400 mg/day was administered orally for about 2 weeks before TUR, and tegaful, 5-FU and uracil concentrations were examined in the blood and the tumor tissue taken about 6 hours after the last administration. Tumor tissue was also taken before and after the UFT administration, and the degree of cell degeneration due to UFT administration were evaluated by light and electron microscopy. The 5-FU concentration was significantly higher in the tumor tissue (0.078 +/- 0.091 microgram/g) than in the serum (0.017 +/- 0.010 microgram/ml). Signs of degeneration were observed in tumor cells after UFT administration in all 6 patients in whom the tumor tissue 5-FU concentration was 0.046 microgram/g or higher. Mitosis was not increased after UFT administration in any of the 12 patients.

Aged↗
PubMed1993

Can the serum protein binding of valproic acid limit the hepatic elimination?

In the previous study, we determined the in vivo binding parameters of valproic acid to serum proteins in seven healthy young adults at steady-state. In this study, we determined the effects of serum protein binding on hepatic elimination with the use of observed data obtained from our previous study of valproic acid. A regression analysis between the binding parameters and the pharmacokinetic parameters was performed. In addition, the relationship between each pharmacokinetic parameter was also analyzed. The order of association constant (K) for valproic acid-serum protein was 10(-2) l/mumol. No significant correlation was found between the binding parameters and the rate of elimination. On the other hand, the average unbound serum concentration was found to be a significantly negative correlation with the unbound (intrinsic) clearance (p = 0.0082). The product of association constant and concentration of free protein (P) correlated positively with the unbound clearance (p = 0.0233) and negatively with the average unbound and total serum concentrations (p = 0.0021 and p = 0.0029, respectively). The results indicate that the membrane permeability of valproic acid is high and that the increase of unbound clearance accompanies directly the decrease of the average unbound and total serum concentrations. Consequently, the KP values are proportional to the unbound clearance due to the rapid changes of the concentration of free protein. Therefore, the dissociation of the valproic acid-serum protein complex is not a rate-limiting factor for hepatic elimination and hence the serum protein binding cannot limit the ability of the liver to extract drug from blood.

Adult↗
PubMed1993

Gastrin-releasing peptide-like immunoreactive substance in bronchoalveolar lavage of idiopathic pulmonary fibrosis and sarcoidosis.

The neuropeptide gastrin releasing peptide (GRP) is present in the lung, and functions as a modulator of tissue growth and repair in fibrotic processes, or as a modulator of cell movement and differentiation in various inflammatory processes, including granulomatous ones. In idiopathic pulmonary fibrosis (IPF), changes in the bronchoalveolar lavage (BAL) content of GRP can be expected. We measured GRP-like immunoreactive substances (GRP-IS) and another neuropeptide, vasoactive intestinal peptide (VIP)-IS in BAL by enzyme immunoassay. Our results showed a decrease in BAL GRP-IS in patients with IPF (26.5 +/- 5.5 pg.mg-1 protein) and sarcoidosis (35.9 +/- 9.2 pg.mg-1), compared to healthy nonsmokers (63.4 +/- 9.0 pg.mg-1). When data were expressed as pg.ml-1 BAL fluid recovered, a decrease was only seen in IPF, not in sarcoidosis. The levels of VIP-IS in BAL were not different between the groups studied. Increased protein levels in BAL had no correlation with the levels of GRP-IS or VIP-IS in BAL. Furthermore, BAL neutrophil percentages had no correlation with the levels of GRP-IS in BAL of patients with IPF. Using reversed phase high performance liquid chromatography (HPLC), several kinds of GRP-IS were detected in BAL. These findings suggest that the decreased level of GRP-IS in BAL may reflect a loss of GRP-producing cells due to chronic lung injury and fibrosis in patients with IPF.

Adult↗
PubMed1992

Escherichia coli H(+)-ATPase: role of the delta subunit in binding Fl to the Fo sector.

The roles of the Escherichia coli H(+)-ATPase (FoFl) delta subunit (177 amino acid residues) was studied by analyzing mutants. The membranes of nonsense (Gln-23----end, Gln-29----end, Gln-74----end) and missense (Gly-150----Asp) mutants had very low ATPase activities, indicating that the delta subunit is essential for the binding of the Fl portion to Fo. The Gln-176----end mutant had essentially the same membrane-bound activity as the wild type, whereas in the Val-174----end mutant most of the ATPase activity was in the cytoplasm. Thus Val-174 (and possibly Leu-175 also) was essential for maintaining the structure of the subunit, whereas the two carboxyl terminal residues Gln-176 and Ser-177 were dispensable. Substitutions were introduced at various residues (Thr-11, Glu-26, Asp-30, Glu-42, Glu-82, Arg-85, Asp-144, Arg-154, Asp-161, Ser-163), including apparently conserved hydrophilic ones. The resulting mutants had essentially the same phenotypes as the wild type, indicating that these residues do not have any significant functional role(s). Analysis of mutations (Gly-150----Asp, Pro, or Ala) indicated that Gly-150 itself was not essential, but that the mutations might affect the structure of the subunit. These results suggest that the overall structure of the delta subunit is necessary, but that individual residues may not have strict functional roles.

Amino Acid Sequence↗
PubMed1992

Predictive value of liver tissue flow in assessment of the viability of liver grafts after extended preservation in pigs.

The crucial damage in cold storage of liver allografts is to the hepatic sinusoidal lining (microcirculation). Using different solutions, we studied whether determinations of graft tissue flow were valuable in estimating the viability of liver grafts. Twenty-three pairs of female pigs underwent orthotopic liver transplantation and were assigned to five groups according to the cold preservation time or solutions used: in group I the liver grafts were stored in Euro-Collins solution (EC) for 4 h (n = 3), in group II the grafts were stored in EC for 12 h (n = 5), in group III the donor was pretreated with azathioprine (AZA), 1 mg/kg per day, orally (p.o.) for 3 days before harvesting and the graft was implanted after 12 h cold storage with EC (n = 6), in group IV the graft was stored in modified University of Wisconsin solution (mUW) for 4 h (n = 3), and in group V the graft was stored in mUW for 24 h (n = 6). Liver tissue blood flow (LTBF) was measured, using a laser doppler device, at 60 min after recirculation of the graft. In the case of EC preservation, LTBF (ml/100 g of liver tissue per min) correlated well with 4-day survival: 21.2 +/- 3.0 ml/100 g of tissue per min mean +/- SD, in group I (3/3, 100%); 10.0 +/- 2.8 ml/100 g of tissue per min in group II (0/5, 0%); and 19.1 +/- 3.4 ml/100 g of tissue per min in group III (5/6, 83.3%) (P < 0.05, group II vs I and III). All grafts with LTBF of more than 15 ml/100 g tissue per min functioned well. However, changes in microcirculation of the mUW-stored livers did not correlate with early function of the graft: 23.0 +/- 2.3 ml/100 g of tissue per min in group IV (4-day survival; 3 of 3, 100%) and 23.5 +/- 9.1 ml/100 g of tissue per min in group V (0 of 6, 0%). This was accompanied by graft dehydration during storage and an increased number of erythrocytes in the hepatic sinusoids post-recirculation. We concluded that assessment of liver tissue flow by LDF was very helpful and easy to apply in predicting liver graft failure in the case of preservation with Euro-Collins solution. However, LTBF should be carefully evaluated as a marker of liver graft viability when the liver graft is preserved with mUW.

Animals↗
PubMed1992

Role of the amino terminal region of the epsilon subunit of Escherichia coli H(+)-ATPase (F0F1).

Escherichia coli strain KF148(SD-) defective in translation of the uncC gene for the epsilon subunit of H(+)-ATPase could not support growth by oxidative phosphorylation due to lack of F1 binding to Fo (M. Kuki, T. Noumi, M. Maeda, A. Amemura, and M. Futai, 1988, J. Biol. Chem. 263, 17, 437-17, 442). Mutant uncC genes for epsilon subunits lacking different lengths from the amino terminus were constructed and introduced into strain KF148(SD-). F1 with an epsilon subunit lacking the 15 amino-terminal residues could bind to F0 in a functionally competent manner, indicating that these amino acid residues are not absolutely necessary for formation of a functional enzyme. However, mutant F1 in which the epsilon subunit lacked 16 amino-terminal residues showed defective coupling between ATP hydrolysis (synthesis) and H(+)-translocation, although the mutant F1 showed partial binding to Fo. These findings suggest that the epsilon subunit is essential for binding of F1 to F0 and for normal H(+)-translocation. Previously, Kuki et al. (cited above) reported that 60 residues were not necessary for a functional enzyme. However, the mutant with an epsilon subunit lacking 15 residues from the amino terminus and 4 residues from the carboxyl terminus was defective in oxidative phosphorylation, suggesting that both terminal regions affect the conformation of the region essential for a functional enzyme.

Amino Acid Sequence↗
PubMed1992

The hearing of the patients treated with hemodialysis: a long term follow-up study.

Sensorineural hearing loss is frequently found in the patients under the treatment with hemodialysis, but the responsible etiological factor(s) still remains controversial. The purpose of the present study was to determine by a long term follow-up study whether hemodialysis per se or other factors induce sensorineural hearing loss. Thirty-seven patients with the observation periods of 4 years or longer were selected for the analysis. Hearing tests were performed soon after the initiation of hemodialysis and every 3 to 12 months thereafter. Significant hearing loss was found in 16 cases (31 ears) at the first test. Although 3 cases (5 ears) of the initially normal group and one case (2 ears) of the group with already existing hearing loss exhibited significant hearing loss, the change in the hearing level was quite minimal in remaining 67 ears during the observation period. Although the cochlea in patients under the treatment with hemodialysis is susceptible to various insults, we conclude that hemodialysis per se does no harm to the cochlea and the hearing can be maintained at the pre-hemodialysis level in the majority of the cases.

Adult↗
PubMed1992

The effect of crossed olivo-cochlear bundle stimulation on acoustic trauma.

To investigate whether the crossed olivo-cochlear bundle (COCB) functions in a protective manner, albino guinea pigs were exposed to sounds of varying intensity (110-130 dB SPL, 3-30 min) with or without electric stimulation of COCB, and the threshold shifts of the compound action potential (CAP) were examined. A statistically significant protective effect was observed in animals exposed to stimuli of intermediate intensity which induce threshold shifts of 50 to 55 dB on average. No protective effect was observed in the groups exposed to greater or milder stimuli. These results are discussed in the light of the available literature.

Acoustic Stimulation↗