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N Okabe

Publications and source records attributed to N Okabe.

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

Drug binding properties of glycosylated human serum albumin as measured by fluorescence and circular dichroism.

Binding properties of Sudlow's site-specific drugs to glycosylated human serum albumin (G-HSA) were investigated using fluorescence and circular dichroism (CD). Dansylamide, phenylbutazone and warfarin were used as site I-specific drugs, and dansylproline, ibuprofen and flufenamic acid were used as site II-specific ones. Similar changes in the fluorescence intensity of dansylamide occurred in the presence of both G-HSA and intact human serum albumin (HSA), while the fluorescence enhancement of dansylproline caused by G-HSA was extremely weakened in comparison with that by HSA. These results suggest that the glycosylation of HSA inhibits the binding of the site II-specific drug, dansylproline, to HSA, while it does not influence the binding of the site I specific drug, dansylamide. The induced ellipticities of the complexes of ibuprofen, flufenamic acid and phenyl butazone with G-HSA were diminished in comparison with those with HSA. With the complexes of warfarin, the induced ellipticity was enhanced. These CD results suggest that the glycosylation of HSA induces microenvironmental changes in the binding sites for the above site-specific drugs which influence the drug binding ability of HSA.

Binding Sites↗
PubMed1994

Effect of guanidine hydrochloride on the conformation of egg yolk low density lipoprotein.

The denaturation of egg yolk low-density lipoprotein (LDL) induced by guanidine hydrochloride (GdnHCl) has been investigated by using circular dichroism (CD) and fluorescence measurements. The transition curves were obtained from changes of the residue ellipticity at 222 nm and the fluorescence intensity of the aromatic residues, tyrosine and fluorescence. Different transition curves were obtained at the molarities of GdnHCl between 2 and 6 M, and between 1 and 4 M from the CD and the fluorescence measurements, respectively. The noncoincidence of the transition curves as well as the asymmetry of the transition curve obtained from the fluorescence measurements suggests that the denaturation process of LDL consists of several transition states. A very low apparent free energy of denaturation (delta G(app) H2O = 3.0 kcal mol-1) obtained by CD data suggests that LDL has an unstable folded structure in its native state.

Circular Dichroism↗
PubMed1993

Thoracoscopic pulmonary resection in two cases using an endoscopic linear stapler and loop ligature.

Recent advances in rigid endoscopic imaging capabilities, light sources, and instrumentation have dramatically expanded the potential role of laparoscopic and thoracoscopic surgery. Moreover, the recent introduction of an endoscopic linear stapling device and loop ligature has made thoracoscopic pulmonary resection possible. We present herein two cases of peripheral pulmonary lesions which were resected thoracoscopically. Case 1 was a 19-year-old man with a history of recurrent pneumothorax due to a left apical bulla who underwent thoracoscopic lung resection using a new stapling device, and Case 2 was a 46-year-old man with a small pulmonary lesion on the left basal segment (S8) who underwent thoracoscopic lung resection using loop ligature. Postoperatively, there was no evidence of air leak in either patient and both were discharged 6 days after surgery. The technical procedures for thoracoscopic lung resection and the clinical courses of both patients are described in this paper.

Adenocarcinoma↗
PubMed1993

[A study on the detection of Helicobacter pylori in children with gastric and duodenal diseases].

Infection of Hellcobacter pylori (H. pylori) in the gastric mucosa is said to participate in the pathogenesis of gastric and duodenal ulcers as well as gastritis. The detection rate of H. pylori in tissue specimens endoscopically taken from adult patients with these diseases was 75.2% (408/542). In affected children (2-15 yrs), on the other hand, 27 biopsies were performed in 22 cases but the initial positive rats was as low as 45.5%. According to the diagnosis, it was 75% for acute gastric mucosal lesion (AGML), 50% for duodenal ulcer, 33% for duodenitis, and 38% in seemingly normal children. When changes in the detection rate of H. pylori was examined after administration of H2 blocking antiulcer agents, it was found to very case by case, e.g. changed in individual disease stages or completely or reoccurrence disappeared.

Adolescent↗
PubMed1993

Effect of divalent metal ions on the binding of thyroxine to bovine serum albumin as measured by fluorescence.

The binding of thyroxine (T4) to bovine serum albumin (BSA) has been studied in the presence and absence of Ca2+, Cu2+ and Zn2+ ions at various pH's in 0.1 M Tris-acetate buffer at 25 degrees C using the fluorescence method. In the presence of 50 microM Ca2+ and Zn2+ and the absence of metal ions, the binding constant (K) increased similarly with increasing pH values from pH 5 to pH 9, and the K value near midpoint, pH 7.4, was 1.66 +/- 0.17 x 10(6) M-1. By contrast, the binding constant remained constant between pH5 and pH9 in the presence of 10 microM Cu2+, with an average value of 1.61 +/- 0.22 x 10(6) M-1, suggesting a significant influence of Cu2+ ions on T4 binding to BSA.

Animals↗
PubMed1993

Effect of inorganic anions on the binding of thyroxine by bovine serum albumin.

The fluorescence method was used to investigate the effect of inorganic anions, SCN-, I-, ClO4- and Br- on the binding of thyroxine (T4) by bovine serum albumin (BSA). The apparent binding constants were evaluated in 0.1M sodium phosphate buffer, pH 7.4 at 25 degrees C containing various concentrations of the anions up to 0.15M. Their values decreased at high anion concentrations. The effectiveness of anions in reducing T4 binding was in the following order: SCN- > I= > ClO4- > Br-. Thermodynamic parameters determined in the presence of 0.1M SCN- suggested that the hydrophobic interaction between T4 and BSA could be reduced by these inorganic anions.

Anions↗
PubMed1992

An HLA study on 149 Japanese patients with Crohn's disease.

To search for possible immunogenetic roles in the pathogenesis of Crohn's disease, we examined the HLA-A, -B, -C, -DR and -DQ locus antigens in 149 Japanese patients with Crohn's disease. All patients were living on Kyushu island. We also examined the HLA of 136 healthy controls who resided in Kyushu. The results were compared with both controls throughout Japan and Kyushu controls. In Japanese patients with Crohn's disease, HLA-DR4, especially -DR4.1, and -DQ4 were more frequent than in the controls throughout Japan and in Kyushu. In light of these observations, an immunogenetic factor may have some role in the development of Crohn's disease. The susceptibility to Crohn's disease may relate to HLA-DR4, especially -DR4.1, and -DQ4, in Japanese patients.

Crohn Disease↗
PubMed1992

Regulation of nerve growth factor and nerve growth factor receptor production by NMDA in C6 glioma cells.

The synthesis of nerve growth factor (NGF) and nerve growth factor receptor (NGFR) were studied in a C6 glioma cell line by Northern blot hybridization. In response to a glutamate agonist N-methyl-D-aspartic acid (NMDA), NGF mRNA increased by up to 2-fold after 4-12 h of culture. The non-NMDA receptor agonists, quisqualate and kainate, did not induce any increase of NGF mRNA, and kainate actually produced a decrease. The increase in NGF mRNA in response to NMDA was dose-dependent at 1, 5 and 10 microM. NGF receptor (NGFR) mRNA showed changes in expression which were similar to those for NGF mRNA, but were less marked. The specific glutamate antagonist 2-aminophosphonovaleric acid (APV) blocked the increase of NGF mRNA produced by NMDA. In the absence of Ca2+, an increase of NGF mRNA was still observed but in the presence of 1 mM ethylglycol-bis-(beta-aminoethyl ether) N,N'-tetraacetic acid (EGTA), NGF mRNA production abolished. The mechanism producing an increase in NGF mRNA by NMDA may be mediated by cyclic AMP since intracellular cyclic AMP and NGF mRNA levels both increased following treatment with NMDA or dibutyryl cyclic AMP.

2-Amino-5-phosphonovalerate↗
PubMed1992

Production and secretion of nerve growth factor by clonal striated muscle cell line, G8-1.

Two specific methods, Northern blot analysis using a 50 nucleotides probe to the conserved region of the nerve growth factor (NGF) gene, and enzyme immunoassay using a monoclonal biotinylated rat anti-NGF IgG-avidin conjugated peroxidase system, were used to demonstrate the production and secretion of NGF by mouse striated muscle cell line G8-1. Calcium ionophore, A23187 (0.1-1 microM), forskolin (0.1-100 microM) and dibutyryl cyclic AMP (0.1-10 mM) strongly decreased the secretion of ir-NGF. The level of NGF mRNA was decreased by veratridine, A23187, forskolin and cyclic AMP but not by cyclic GMP. Consequently, we conclude that the secretion of NGF molecules paralleled the changes of NGF mRNA levels in the cells induced by all agents tested. Carmamylcholine also decreased the level of NGF mRNA. Immunoblot analysis suggested that denatured ir-NGF molecules exist in a higher molecular weight form (22 KDa) than those of mouse submaxillary gland (13 KDa). Both Ca(2+)- and cAMP mediated mechanisms contribute to the decreased production of NGF mRNA in the cells and the consequent inhibition of secretion of NGF molecules. Finally, molecular cloning of NGF of G8-1 cells was conducted and confirmed the structure of the gene that consists of 1, 3, and 4 exons deleting exon 2. Thus, G8-1 NGF is derived from transcript B.

Amino Acid Sequence↗
PubMed1992

[Current alteration of Helicobacter pylori in gastro-duodenal diseases].

The current alteration of the detection rate of Helicobacter pylori (H. pylori) on mucous membranes of the stomach has been surveyed and reviewed for 49 cases of gastro-duodenal diseases. The survey has been conducted for 3 years and an endoscopic examinations have been performed 2-8 times. On the first visit, the diagnosis can be made endoscopically, and H2 blockers and another agents were used as therapeutic drugs. The detection rate was 67.3% (33 cases) for positive cases and positive reaction cases, while the rate was 32.6% (16 cases) in negative cases and negative reaction cases. Among them, the most commonly observed disease was atrophic gastritis, followed by duodenal ulcer, and acute gastric mucous lesions (AGML). Peptic ulcer was not seen. After administration of H2 blockers and anti-ulcer agents, the H. pylori-detection rate was found to fluctuate according to the diseases and alterations in the morbidity period. Some cases indicated the disappearance of H. pylori in accordance with the improvement of the lesion site.

Adult↗
PubMed1992

Thyroxine binding properties of glycosylated bovine serum albumin.

Thyroid hormone, thyroxine (T4) binding properties of glycosylated bovine serum albumin (G-BSA), and intact BSA were studied by the fluorescence method. The apparent binding constants for intact BSA were 0.8 (0.16) x 10(6) M-1 at pH 5.0 and 2.18 (0.06) x 10(6) M-1 at pH 9.5 at 25 degrees C. T4 binding for G-BSA was independent of pH and the apparent binding constant was 1.4 x 10(6) M-1. Thermodynamic parameters were also evaluated from the Van't Hoff plots of the apparent binding constants at pH 7.4 and 8.5. At both pH's, the free energy, enthalpy and entropy changes were almost the same for both G-BSA and BSA.

Animals↗
PubMed1992

Effect of pH and guanidine hydrochloride on the conformation of 57 kDa rat liver nuclear thyroid hormone binding protein measured by fluorescence.

The denaturation of the 57 kilodalton (kDa) rat liver nuclear thyroid hormone binding protein (NTHB) by pH and guanidine hydrochloride (GdnHCl) has been investigated with the fluorescence method. The acid and alkaline fluorescence quenching suggests that the structure of NTHB is invariant in the relatively narrow pH region of approximately pH 7-9. A cooperative conformational transition occurred in GdnHCl concentrations of 1.5-2.5 m. The apparent free energy of unfolding of NTHB, delta G(appH2O) was evaluated as 6.31 (+/- 0.12) kcal.mol-1 at pH 7.7, 25 degrees C.

Animals↗
PubMed1992

Robot system for preparing lymphocyte chromosome.

Towards the automatization of the scoring of chromosome aberrations in radiation dosimetry with the emphasis on the improvement of biological preparations, the conventional culture and harvesting method was modified. Based on this modified method, a culture and harvest robotic system (CHROSY) for system (CHROSY) for preparing lymphocyte chromosome was developed. The targeted points of the modification are as in the following. 1. Starting culture with purified lymphocytes in a fixed cell number. 2. Avoiding the loss of cells in changing the liquids following centrifugalization. 3. Keeping the quantity of the liquids to be applied to the treatments of cells fixed. 4. Building a system even a beginner can handle. System features are as follows. 1. Operation system: Handling robot having 5 degrees of freedom; a rotator incubator with an automatic sliding door; units for setting and removing pipette tips; a centrifuge equipped with a position adjuster and an automatic sliding door; two aluminum block baths; two nozzles as pipettes and aspirators connected to air pumps; a capping unit with a nozzle for CO2 gas; a compressor; and an air manipulated syringe. 2. Control system: NEC PC-9801RX21 with CRT; and program written in Basic and Assembly languages on MS-DOS. It took this system 2 hours and 25 minutes to harvest 2 cultures. A fairly good chromosome slide was made from the sample harvested by CHROSY automatically.

Chromosomes↗
PubMed1992

[Pharmacokinetic and clinical studies on meropenem].

Pharmacokinetic and clinical studies on meropenem (MEPM, SM-7338), a new developed carbapenem, were performed and the following results were obtained. 1. Absorption/excretion: Pharmacokinetics of MEPM was studied in 9 children using doses of 10 mg/kg and 20 mg/kg by a 30 minute-drip infusion. Peak plasma levels and plasma half-lives of the 2 doses were 28.4 and 43.0 micrograms/ml, and 0.70 and 0.80 hours, respectively. Their urinary recovery rates were 42.5 to 67.6% and 29.9 to 62.6%, respectively. Cerebrospinal fluid levels and penetration rates of MEPM in a patient with purulent meningitis were 0.66 to 4.01 micrograms/ml and 1.6 to 12.2%, respectively. 2. Clinical study: Forty-nine patients were treated with MEPM at doses exceeding 100 mg/kg/day with purulent meningitis and 30 to 60 mg/kg/day with other infections. MEPM gave "excellent" or "good" responses in 48 cases, an efficacy rate of 98.0%. Only one patient with subdural abscess showed fair response. Diarrhea and rash were observed in 1 case each. Abnormal laboratory test results were noted in 5 patients including elevation of GOT, GPT and eosinophils. In no cases the treatment had to be discontinued.

Absorption↗
PubMed1992

A comparative study of once-a-day morning and once-a-day bedtime administration of 40 mg famotidine in treating gastric ulcers.

A randomized controlled study comparing once-a-day morning and once-a-day bedtime administration of 40 mg famotidine in treating gastric ulcers was carried out in 179 Japanese patients. Endoscopic examinations were performed at the baseline and repeated at 4-wk intervals until healing was confirmed. One hundred and sixty-four patients fulfilled the evaluation criteria (81 in the morning group and 83 in the bedtime group). The healing rates were 50.7% after 4 wk and 88.9% after 8 wk in the morning group and 46.5% after 4 wk and 74.7% after 8 wk in the bedtime group. The difference was statistically significant after 8 wk. Significant reductions from baseline for overall pain, beginning during the first 3 days, were likewise found in the two treatment groups. However, the pain severity in hunger state 1 wk after treatment was significantly higher in the bedtime group than in the morning group. Thus, once-a-day morning administration of 40 mg famotidine seems to be superior to once-a-day bedtime administration of 40 mg famotidine in treating gastric ulcers.

Adult↗
PubMed1991

Production of nerve growth factor in rat skeletal muscle.

Production of the nerve growth factor (NGF) was confirmed by Northern blot hybridization using a specific probe of synthetic cDNA. In normal rat skeletal muscle, this probe clearly showed a band equivalent to 1.3 kilobases (kb) of messenger RNA (mRNA) of NGF of male mouse submaxillary gland. By denervation, the density of the bands derived from muscles increased by a factor of more than 3 at 4 and 6 days later compared to the control. The synthesis of mRNA of NGF in muscle was also confirmed following tetrodotoxin (TTX) blockade of sciatic nerve without denervation.

Animals↗