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Biomedical subjects

K Nakata

Publications and source records attributed to K Nakata.

At least 451 records · Page 25Linked to original sources
PubMed1987

Sarcomatous variants of Wilms' tumor. Immunohistochemical and ultrastructural comparison with classical Wilms' tumor.

Two cases of malignant rhabdoid tumor of the kidney (MRT) and two cases of bone metastasizing renal tumor (BMRT) were studied using electron microscopy and immunohistochemistry, in an attempt to evaluate the histogenetic relation to classical Wilms' tumor (2 cases). The two cases of MRT showed ultrastructural features of intermediate filament clusters in the cytoplasm. Vimentin, keratin, laminin, and peanut (PNA) lectin were immunohistochemically demonstrated in two cases of MRT. Tissue polypeptide antigen (TPA) was detected in one case. As for BMRT, the metastatic lesion exhibited numerous rosette-like structures of tumor cells. Vimentin was immunohistochemically demonstrated in one case, but no other antibodies were stained in two cases. Two cases of classical Wilms' tumor immunohistochemically demonstrated vimentin, keratin, PNA lectin, and TPA. MRT and BMRT fall within the broad spectrum of Wilms' tumors from the histogenetic aspect, but their clinical behavior is distinct.

Bone Neoplasms↗
PubMed1987

Effects of an angiotensin-converting enzyme (ACE) inhibitor, SA446, on tissue ACE activity in normotensive, spontaneously hypertensive, and renal hypertensive rats.

Effects of an angiotensin-converting enzyme (ACE) inhibitor, SA446, on the renin-angiotensin system, particularly on tissue ACE activity, were studied in Wistar-Kyoto normotensive rats (WKY), spontaneously hypertensive rats (SHR), and two-kidney, one-clip renal hypertensive rats (RHR) by repeated oral administration for 7 days. SA446 (45 mg/kg/day p.o.) inhibited ACE activity in the lung, brain, kidney, heart, and whole blood throughout the administration period in WKY, but showed a slight hypotensive action and no inhibition of aorta ACE activity. On the other hand, SA446 had an apparent hypotensive action at the same dose in SHR and inhibited ACE activity significantly in the aorta as well as the kidney and whole blood during the administration period. Furthermore, enzyme activity in the aorta, kidney, heart, and whole blood was also inhibited at a hypotensive dose of SA446 (10 mg/kg/day p.o.) in RHR. The inhibition in whole blood and kidney was almost complete, and the inhibition in the aorta was greater on day 7 than on day 1. The maximum decrease of blood pressure was correlated with the maximum inhibition in aorta ACE activity, but not in brain, lung, or heart ACE activity. In addition, a good positive correlation was observed between the basal blood pressure and the basal aorta ACE activity in WKY, SHR, and RHR, although there was no correlation in the brain, lung, kidney, heart, or whole blood. These results suggest that the antihypertensive action of SA446 by repeated administration may be due to inhibition of arterial ACE activity in addition to inhibition of plasma and kidney ACE activity.(ABSTRACT TRUNCATED AT 250 WORDS)

3-Mercaptopropionic Acid↗
PubMed1987

Standardization of bromelin for use in routine one-stage antibody screening.

A simple standardization method for bromelin used in routine one-stage antibody screening is described. Bromelin proteinase activity was assayed using casein as the substrate, and converted to units. The use of proteinase activity units for standardization of bromelin resolves differences between commercial preparations.

Bromelains↗
PubMed1987

General pharmacological properties of the potent angiotensin converting enzyme inhibitor rentiapril.

Pharmacological properties of (2R,4R)-2-(o-hydroxyphenyl)-3-(3-mercaptopropionyl)-4- thiazolidinecarboxylic acid (rentiapril, SA 446), a potent inhibitor of angiotensin converting enzyme, were examined. SA 446 given intravenously lowered blood pressure in anesthetized rats and rabbits dose-dependently, while it had no remarkable effect in conscious rats even at a dose of 100 mg/kg orally or intravenously. SA 446 had no effect on heart rate in anesthetized rabbits up to 100 mg/kg i.v. In anesthetized dogs, SA 446 at a dose of 1 mg/kg i.v. produced decrease in blood pressure accompanied with coronary and vertebral arterial vasodilations, but gave no change in heart rate. SA 446 had no influence on respiration of anesthetized rabbits at doses up to 100 mg/kg i.v. The drug showed no effect on contractile force or beating rate of isolated guinea pig atria at concentrations up to 10(-4) mol/l, but caused vasoconstriction of isolated rabbit ear vessels at a 0.1 ml dose of 3 X 10(-2) mol/l solution or more and relaxation of isolated rat thoracic aortas at concentrations over 3 X 10(-4) mol/l. SA 446 had no influence on beta 1- or beta 2-adrenoceptors of isolated guinea pig atria and tracheas, respectively. Neither was a calcium antagonistic action observed. SA 446 did not influence the central nervous system, neuromuscular transmission, spontaneous movement or contractile response to several agonists of isolated smooth muscles, secretion of digestive glands, blood coagulation, hemolysis or blood glucose level, and it showed no muscle relaxant, antispasmodic or local anesthetic effect.(ABSTRACT TRUNCATED AT 250 WORDS)

3-Mercaptopropionic Acid↗
PubMed1987

[A study on flomoxef against respiratory infections in the aged].

Flomoxef (FMOX, 6315-S) was used in the treatment of 10 patients (male 8, female 2) with respiratory infections, and clinical responses and side effects of FMOX were evaluated. The mean age of the patients was 68.2 years, and the mean body weight was 45.8 kg; this background of the patients indicates that most of them were elderly, and light in body weight. FMOX was administrated by drip infusion in 1 g doses twice daily in all the cases. The mean duration of FMOX therapy was 14 days, and the mean total dose administered was 28 g. Efficacy rate was 80% in the 10 cases. Adverse reactions were not observed and no abnormalities in laboratory tests were detected. In conclusion, FMOX is an effective antibiotic in the treatment of aged patients with respiratory infections.

Aged↗