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Biomedical subjects

S Kasamatsu

Publications and source records attributed to S Kasamatsu.

At least 19 recordsLinked to original sources
PubMed1999

Selective ablation of porcine and rabbit liver tissue using radiofrequency: preclinical study.

Temperature changes and their distribution induced by 13.56-MHz radiofrequency (RF) heating of agar phantom and porcine and rabbit liver were investigated. It was possible to produce selective local heating of approximately 50 degrees C in the RF field of 2 x 2 x 2 cm(3) of the pig or rabbit liver. Coagulation necrosis after heating became pronounced and the margin between the coagulated lesion and normal tissue became clearer with time. Within 1 week after RF heating at 50 degrees C for 20 min, the coagulated area was replaced selectively and totally by necrotic tissue.

Animals↗
PubMed1989

Quantification of L-3-(3-hydroxy-4-pivaloyloxyphenyl)alanine (NB-355) by high-performance liquid chromatography using o-phthalaldehyde/N-acetyl-L-cysteine derivatization.

A new and rapid high-performance liquid chromatographic assay has been developed for the determination of L-3-(3-hydroxy-4-pivaloyloxyphenyl)alanine (NB-355,I), a novel prodrug of L-DOPA. The method involves precolumn derivatization of the drug in biological samples with o-phthalaldehyde (OPA) and N-acetyl-L-cysteine (NAC) in a triethanolamine buffer (pH 8.0), giving a fluorescent compound that is stable for 2 h at 4 degrees C. Use of an internal standard improved the assay in accuracy and reliability. A programmable injector allowed automatic derivatization of large numbers of samples. Chromatographic separation was performed on a reversed-phase column (Capcell Pak C18) in which the silica gel was coated with silicone polymer. The peaks corresponding to compound I and the internal standard were eluted within 16 min with a mobile phase of acetonitrile-phosphate buffer (pH 7.1). The reliable limit of quantification was 0.5 pmol per injection (0.05 micrograms equivalents of L-DOPA per ml in plasma). The method was successfully applied for the measurements of dog plasma concentrations after oral dosing of compound I.

Acetylcysteine↗
PubMed1985

[Pharmacological studies of N-(2-mercapto-2-methylpropanoyl)-L-cysteine (SA96). V. Effects of SA96 in combination with indomethacin or prednisolone on adjuvant arthritis in rats].

SA96 in combination with indomethacin or prednisolone was investigated for their effects on the adjuvant arthritis in Lewis rats. SA96 given orally at a dose of 10 mg/kg inhibited the inflammation of adjuvant treated foot and untreated foot and the increase of serum Cu concentration which followed the development of adjuvant arthritis, but 2 mg/kg had no effect. Indomethacin given orally at a dose of 0.1 mg/kg or prednisolone given orally at a dose of 0.4 mg/kg also inhibited the adjuvant arthritis. Prednisolone suppressed the decrease of A/G ratio. Indomethacin and prednisolone, however, had no effects on the increase of serum Cu concentration. SA96 at a dose of 10 mg/kg in combination with indomethacin was more effective than the treatment of each drug alone on inflammation of adjuvant treated and untreated foot, serum Cu concentration, erythrocyte sedimentation rate and A/G ratio. The combination of SA96 at a dose of 2 mg/kg or 10 mg/kg with prednisolone had similar synergistic effects towards the adjuvant arthritis in rats.

Animals↗
PubMed1985

[Pharmacological studies on N-(2-mercapto-2-methylpropanoyl)-L-cysteine(SA96). IV. Effects of SA96 and its main metabolite, SA679, on denaturation of human gamma-globulin and adjuvant arthritis in rats].

SA96 and its main metabolite, SA679, were investigated for their effects on denaturation of human gamma-globulin and bovine serum albumin (BSA) and on adjuvant arthritis in Lewis rats. The heat denaturation of human gamma-globulin and BSA enhanced by Cu2+ was inhibited by SA96, SA679 and D-penicillamine, and the inhibitory effect of SA96 was the most potent. In adjuvant arthritis rats, SA96 given orally at a dose of 10 mg/kg from the same day as the adjuvant injection inhibited significantly the swelling of adjuvant treated foot and untreated foot, increase of the relative organ weights of the adrenals, liver and kidney, and increase of serum Cu concentration; but at a dose of 100 mg/kg, it did not show any effects on these parameters. On the other hand, SA96 given from three days before the adjuvant injection showed the inhibitory effects at a dose of 100 mg/kg as well as 10 mg/kg. These results suggest that the effect of SA96 on adjuvant arthritis in rats depends on its administration schedule. SA679 also inhibited the adjuvant arthritis at a dose of 100 mg/kg, but its effect was less potent than that of SA96.

Animals↗
PubMed1983

Effect of BR-227, a new bromhexine derivative, on secretory activities of tracheal secretory cells.

The effects of BR-227 on secretory activities of canine tracheal secretory cells including behavior of mucus glycoproteins were investigated histologically and histochemically. Following BR-227 treatment at a concentration of alcian blue at pH 2.5 and periodic acid-Schiff (AB (pH 2.5)/PAS) decreased in a concentration-dependent manner. Furthermore, a decrease in the thickness of the acini of submucosal glands and in marked increase in the ratio of acinar inner diameter of the gland to tracheal wall were induced after application of BR-227 at a concentration range of 10(-7) to 10(-4) M. The numbers of goblet and submucosal glandular cells which stained blue and purple with AB (pH 2.5)/PAS were decreased by BR-227 treatment in a concentrations-dependent way, whereas the cells which stained red were markedly increased. In the experiment using a combination of AB at pH 1.0 and PAS, a decrease in sulfated glycoproteins in those secretory cells was observed. Total saccharide and protein concentrations in the incubation fluid increased with BR-227 treatment, while N-acetylhexomsamine concentration tended to decrease. These findings suggest that BR-227 stimulates secretory activities of both goblet cells and submucosal glands, and lowers mucus viscosity in the secretory cells.

Animals↗
PubMed1983

[Effect of brovanexine on secretory activities of tracheal secretory cells].

The expectorant effect of brovanexine (BvX) was investigated histologically and histochemically using isolated canine trachea. Following BvX treatment, the number of goblet cells (GC) stained positively with the combination procedure of alcian blue at pH 2.5 or pH 1.0 and periodic acid-Schiff was unaffected. The number of GC which stained blue and purple (stain index B & P) was reduced, while the number of GC that stained red (stain index R) was increased. The thickness of the acini of submucosal glands (SG) markedly decreased with 10(-5) and 10(-4)M BvX, and the ratio of the acinar inner diameter to the tracheal wall thickness significantly increased with 10(-4)M BvX. Stain index B & P of glandular cells decreased with 10(-5) and 10(-4)M BvX, which was accompanied by a marked increase in the stain index R. BvX treatment caused increases in total saccharide and protein concentrations in the incubation fluid, while N-acetylhexosamine slightly decreased. Both the BvX-induced histological changes in glandular cells and changes in concentrations of macromolecular components in the incubation fluid were much the same degree as those induced by bromhexine (Bh). The BvX-induced histochemical changes in secretory cells, however, were slighter than those induced by Bh. These findings suggest that BvX is an expectorant possessing both the secretagogic action selectively on SG and a mucolytic action toward acid glycoproteins in granules of secretory cells.

Animals↗
PubMed1980

Pharmacological studies of 1-(2-chloro-4-hydroxyphenyl)-2-t-butylaminoethanol (HOKU-81), a new bronchodilator. 1st Communication: Bronchodilator and cardiovascular actions.

Bronchodilating action and influence on the cardiovascular system of 1-(2-chloro-4-hydroxyphenyl)-2-t-butylaminoethanol (HOKU-81), which is one of metabolites of tulobuterol obtained from rat urine, were examined using the isolated tracheae and atria of guinea pigs in vitro and dogs in vivo in comparison with those of the parent drug, i.e., tulobuterol isoprenaline, salbutamol and other reference bronchodilators. HOKU-81 was approximately 8 times more potent than tulobuterol, approximately twice as potent as salbutamol, and approximately as potent as isoprenaline in relaxing effect on the isolated tracheal smooth muscle preparation of guinea pigs. This effect of HOKU-81 seems to be due to direct action on the adrenergic beta-receptor. In anaesthetized dogs, bronchodilating effect of HOKU-81 was much more potent than that of tulobuterol and was approximately as potent as that of salbutamol when administered i.v., and its effect lasted for many hours. When administered orally, the duration of bronchodilating effect of HOKU-81 was almost as long as that of salbutamol. The cardiac stimulating effect of HOKU-81 examined in the isolated guinea pig artia and in anaesthetized dogs was weaker than those of isoprenaline and salbutamol, though stronger than that of tulobuterol. In the present studies in vitro as well as in vivo, the selectivity ratio of HOKU-81 for beta-adrenoceptors in the tracheal smooth muscle vs. those in the right atrial muscle was the largest of all the bronchodilators used.

Acetylcholine↗
PubMed1975

Indirect hemagglutination test of Rickettsia orientalis: its specificity for reference strains, Karp, Gilliam and Kato.

Amberlite XE-64 and bovine serum albumin-treated rickettsia suspension, which was prepared from the chicken yolk sacs infected with each of 3 reference strains of Rickettsia orientalis, Karp, Gilliam and Kato, was sonicated at 10 KC for 15 min at 4 degrees C and centrifuged at 10,000 rpm for 40 min at 0 degrees C. The supernatant was used to sensitize the formalinized and tanned sheep red blood cells (SFTSRC). This antigen (2.5%) could be preserved for at least 1 wk at 4-8 degrees C and at least a month, if merthiolate (1:10,000) was added. Each SFTSRCP of 3 reference strains was found to be specific in indirect hemagglutination (IHA) reaction with each homologous immune serum and there was little cross reaction with the heterologous one. This minor cross reaction might be due to the presence of a small amount of soluble antigen in SFTSRC. No cross IHA reaction with the typhus fever immune serum was observed. The IHA test was considered to be useful for the diagnosis of scrub typhus.

Antibody Specificity↗