Search PubMed⌕ Search

Biomedical subjects

A Hara

Publications and source records attributed to A Hara.

At least 631 records · Page 35Linked to original sources
PubMed1976

Chemical and hemolytic properties of sphingolipids modified by ozonolysis and reduction.

Various sphingolipids were chemically modified in their sphingosine base by ozonolysis and reduction. The derivatives obtained from Forssman globoside, globoside I, galactosyl ceramide, and sphingomyelin were purified and all were found to be hemolytic. The presence of cholesterol could inhibit this activity. The simultaneous cleavage at a double bond in the fatty acid as well as in the sphingosine of Forssman globoside resulted in the formation of a more polar compound with no detectable hemolytic activity. The haptenic reactivity was retained after ozonolysis and reduction of Forssman globoside, as shown by precipitin line formation in agar gel with appropriate antibodies. The results indicate that this modification procedure may be useful in studies of the physiological and immunological properties of sphingolipids.

Chemical Phenomena↗
PubMed1976

Plasma renin and vascular complications in substrains of the spontaneously hypertensive rat, with a reference to water and electrolyte balance.

The stroke-prone and stroke-resistant substrains of the spontaneously hypertensive rat (SHR) were employed for an evaluation of possible role of reninangiotensin system and of water and electrolyte balances in inducing hypertensive vascular lesions. Serial study on plasma renin level and vascular changes did not support the hypothesis that plasma renin is a major risk factor in the development of cardiovascular complications. The high plasma renin level seen in advanced stages of hypertension appeared to be a result of severe vascular damages, indicating malignant transformation of hypertension. In this state, water turnover was enhanced without any abnormality in electrolyte balances. A possible mechanism involved in the malignant course of hypertension is discussed.

Animals↗
PubMed1976

Isolation and identification of benzodiazepine drugs and their metabolites in urine by use of Amberlite XAD-2 resin and thin-layer chromatography.

We used the method described here to detect and identify seven benzodiazepine derivatives--diazepam, chlorodiazepoxide, nitrazepam, cloxazolam, oxazolam, oxazepam, and medazepam--and their metabolites in the urine of rabbits given the seven drugs orally. We column-chromatographed 25-ml samples of urine on Amberlite XAD-2. The drugs and their metabolites in the urine were adsorbed by the resin, irrespective of urinary pH, and upon successive elution with methanol and ethyl acetate/methanol/acetic acid (90/10/0.1 by vol) they could be separated and extracted from the normal components of urine with satisfactory analytical recovery. The conjugated metabolites were then enzymatically hydrolyzed and the hydrolysate was extracted into ethyl acetate and the extract thin-layer chromatographed to detect and identify each drug and each of its metabolites. In an experiment in which the urine of human subjects given 5 mg of nitrazepam orally was analyzed by this method, the metabolites of nitrazepam in the 24-h urine could be identified satisfactorily.

Animals↗
PubMed1975

Long chain base and fatty acid compositions of equine kidney sphingolipids.

Equine renal glycopshingolipids were composed of galactocerebroside, glucocerbroside, ceramide dihexoside, ceramide trihexoside, sulfatide, globoside I, Forssman globoside, and hematoside. Free ceramide and sphingomyelin were also found in equine kidney. Their long chain bases consisted of sphingosine, dihydrosphingosine, C18-phytosphingosine, and C20-phytosphingosine, whereas the fatty acids were separated into two groups: nonhydroxy and hydroxy fatty acids. Ceramide monohexoside was separated into five spots by TLC on borax-impregnated plates. The major component of ceramide monohexoside was glucocerbroside which accounted for 46.6% of the total ceramide monohexoside and contained a ceramide consisting of phytosphingosines and hydroxy fatty acids. The long chain bases of hematoside and sulfatide contained dihydroxy and trihydroxy bases in nearly equal ratios. On the other hand, the other glycosphingolipids contained mainly dihydroxy bases, though with significant amounts of trihydroxy bases. Free ceramides were separated into four groups by silicic acid column chromatography and the major ceramides were of two kinds, consisting of dihydroxy bases and nonhydroxy fatty acids (49.9% of the total ceramide) and of trihydroxy bases and nonhydroxy fatty acids (38.5% of the total ceramide). The minor ceramides contained predominantly hydroxy fatty acids. Neither trihydroxy bases nor hydroxy fatty acids were detected in spingomyelin.

Animals↗
PubMed1975

Plasma renin and hypertensive vascular complications: an observation in the stroke-prone spontaneously hypertensive rat.

The hypothesis that plasma renin is a major risk factor in the development of cardiovascular complications of hypertension was evaluated in a model animal, the spontaneously hypertensive rat (SHR). Plasma renin levels and pathological findings were studied in stroke-prone and -resistant strains of SHR at various ages. The stroke-prone strain showed significantly higher plasma renin levels at and after seven months of age, while the stroke-resistant strain showed no significant differences from the control at any age. High plasma renin levels were always associated with evident vascular complications in the kidney and the brain, indicating underlying angionecrosis and malignant transformation of hypertension. However, no evidence indicated that a higher plasma renin preceded the development of vascular lesions. Thus the high plasma renin would be a result rather than the cause of hypertensive vascular lesions.

Animals↗
PubMed1975

Hypertensive vascular lesions and renin or lysosomal enzymes in rats.

In rats treated with DOCA plus high salt or with high salt alone, hypertensive rats with renal vascular lesions showed an incomplete suppression of KRA. Cathepsin activity of rat kidney was higher under high salt loading than in the control. Beta-glucuronidase activity was greatest in rats with renal vascular lesions and smallest in rats fed on normal chow. RNase and DNase activities were greater in rats with renal vascular lesions than in rats without renal vascular lesions under high salt loading. 2) In rats of both sexes SHR showed greater KRA and cathepsin activities than WK rat under high salt loading. In female rats DNase, RNase and beta-GPase activities were greater in SHR than in WK rat under high salt loading. 3) KRA was higher in SHRSP aged 10 months than in SHRSR, though KRA of SHR was smaller than KRA of WK rat. Cathepsin activity was greater in SHRSP than in SHRSR. DNase and beta-NAGA activities were greater in SHR than in WK rat. 4) In 7 weeks of age SHRSR showed more PRC than SHRSP. At the age of 10 months SHRSP showed higher PRC than WK rat. The roles renin and lysosomal enzymes in hypertensive renal vascular lesions were discussed to some extent.

Animals↗
PubMed1975

Lipids and lipoproteins of serum and organ tissues in a case of familial hyperlipoproteinemia type II.

Lipids and lipoproteins of serum and various organ tissues of a patient with familial hyperlipoproteinemia homozygous Type II were studied. It was found that low density lipoprotein between densities of 1.006 and 1.063 was a major component of serum of the patient. The isolated low density lipoprotein appeared to be rather similar to that of normal human serum from the viewpoints of chemical composition and physico-chemical properties. Antibody against the low density lipoprotein of the patient reacted not only with the same lipoprotein, but also with normal human low density lipoproteins. Immunoelectrophoresis of the antibody gave a single precipitin line against only the low density lipoprotein. Immunofluorescent techniques using the fluorescein labeled antibody showed localization of low density lipoprotein in cytoplasm of hepatocytes of both the patient and other human. No fluorescences were found in other organ cells except in their capillary tubes and renal glomerulus in the hyperlipoproteinemia Type II. It was noted that tuberous xanthomata contained fairly large amounts of cholesterol and cholesterol ester. Fatty acid composition of neutral lipids and phospholipids from the serum low density lipoprotein, xanthomata, liver and other organ tissues were compared with each other. Chomesterol ester of the xanthomata contained much smaller amounts of polyunsaturated fatty acids as compared with those of the low density lipoprotein and other tissue. Also, composition of free fatty acids in liver differed from those of other tissues.

Amino Acids↗
PubMed1975

Immunochemical studies of lipids. IV. Chemical modification of Forssman globoside and immunological activities.

N-deacylated and N-deacetylated Forssman globoside obtained from Forssman globoside by partial alkaline hydrolysis had no Forssman activity. After re-N-acetylation of the N-deacylated and N-deacetylated Forssman globoside, the N-acetylsphingosyl Forssman oligosaccharide thus obtained recoverd its activity. Moreover, after ozonolysis and reduction of the N-acetylsphingosyl Forssman oligosaccharide, the 2-N-acetoamido-1,3,4-trihydroxybutanoyl Forssman oligosaccharide thus obtained still had a haptenic activity, but couldn't show a precipitin reaction with Forssman antibody. On the other hand, the Forssman globoside and the N-acetylsphingosyl Forssman oligosaccharide gave rise to precipitin line on agar gel double diffusion, it was thus concluded that the aqueous solution of these substances formed spherical micelles to behave like a fairly macromolecular multivalent antigen.

Acetylation↗