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Biomedical subjects

Y Harada

Publications and source records attributed to Y Harada.

At least 829 records · Page 46Linked to original sources

Assay methods for prekallikrein and kininogens and their applications.

Prekallikrein activity in plasma was assayed using a synthetic peptidyl fluorogenic substrate (carbobenzoxy-L-phenylalanyl-L-arginine 4-methylcoumarinyl-7-amide), after activation of prekallikrein by acetone and kaolin. For total kininogen assay, the pretreatment of plasma at pH 2.0 was the best to eliminate bradykinin potentiators and kininase activity, before addition of trypsin to convert kininogen to bradykinin. Assay method of high molecular weight (HMW) kininogen was established by conversion of HMW-kininogen to bradykinin through activation of Hageman factor by glass powder and that of low molecular weight (LMW) kininogen was also by treatment of HMW-kininogen-depleted plasma in the same way as that for total kininogen. The marked reduction of prekallikrein and HMW-kininogen, not of LMW-kininogen, was found in pleural fluid of rat carrageenin pleurisy, and in plasma after i.v. injection of bromelain in rats. Members of the pedigree of hereditary angioneurotic edema patients also show low levels of prekallikrein and kininogens in plasma.

Animals↗

Non-specific antagonism against thromboxane A2 of 7-ethoxycarbonyl-6,8-dimethyl-4-hydroxymethyl-1(2H)-phthalazinone (EG-626) in contraction of isolated smooth muscles.

7-Ethoxycarbonyl-6,8-dimethyl-4-hydroxymethyl-1(2H)-phthalazinone (EG-626) was reported as an antagonist of thromboxane (Tx) A2 in the contraction of rabbit aorta. It was, however, observed that EG-626 did inhibit the contraction of superfused rabbit aorta, but also did inhibit that of rabbit coeliac artery, rat stomach strip and rat colon induced by TxA2, PG endoperoxides, angiotensin II and PGF2 alpha in non-specific manner. EG-626 had no effect on the biosynthesis of PG endoperoxides as well as TxA2. These results indicate that EG-626 is not a TxA2 antagonist, but has a general inhibitory effect on the smooth muscles. This inhibitory effect of EG-626 may be explained by the inhibition of phosphodiesterase.

Angiotensin II↗

Transmission and scanning electron microscopic studies of rhinoscleroma.

Using both types of electron microscope, combined transmission and scanning electron microscopic studies were done on 6 patients with rhinoscleroma. The present work suggests the possibility of two types of organisms causing the disease: one type--being in the majority--was a rod-shaped bacillus measuring about 3 micrometers; the other type was a short, stout bacillus with terminal spiral cilia. The ultrastructure of these bacilli has been described. The advantages and limitations of each type of electron microscopy in the investigation of rhinoscleroma have been discussed.

Humans↗

Experimental Pseudomonas infection in mice: effect of single cyclophosphamide administration on Pseudomonas infection.

The kinetic effect of cyclophosphamide (CY) was investigated using the immune response to sheep red blood cells (SRBC), activation of the mononuclear macrophage system and altered susceptibity to pseudomonas infection. The level of delayed type hypersensitivity (DTH) was enhanced with suppressed antibody formation, when antigenic stimulation was given about 3 days after CY administration. In contrast, antibody formation increased markedly when challenged with antigen about 10 days after CY administration. Activity of macrophage system as measured by rate of carbon clearance and spreading of peritoneal macrophage was decreased within 6 days after CY, therefore increased to a peak at the 13th day of CY administration. CY increased a susceptibility to pseudomonas infection at the early time of its administration such as the 3rd day, whereas more increased resistance was observed at the later time such as the 13th day. These results indicated that B-lymphocyte depletion included by administration of sublethal dose of CY (200mg/kg) was followed by vigorous hyperplasia of B-lymphocyte.

Animals↗

[Sphenoethmoidal meningoencephalocele associated with agenesis of corpus callosum and median cleft lip and palate--report of two cases (author's transl)].

Two cases of sphenoethmoidal meningoencephalocele are reported. Patients are a 1 year 7 month old boy and a 3 year old boy. Although sphenoethmoidal meningoencephalocele is reasonably classified as a type of basal meningoencephalocele, the authors could not find out any reports on cases designated as such. The reason must be in difficulty to differentiate the sphenoethmoidal type from the transsphenoidal type. Authors could differentiate them using CT scan. Two other cases were found in cases reported as transsphenoidal type. Further, it is assumed that these four cases including our two cases were accompanied with agenesis of corpus callosum and median cleft lip and palate. Despite the fact that the respective anomalies are rare, they are completely the same, which signifies the possibility that 1) sphenoethmoidal meningoencephalocele, 2) agenesis of corpus callosum and 3) median cleft lip and palate are a single unit of congenital anomalies. It probably should be considered that the cause for these malformations were present even before the formation of the lips which takes place earliest, that is, sixth week of gestation.

Abnormalities, Multiple↗