Biomedical subjects

M Sugano

Publications and source records attributed to M Sugano.

332 records · Page 19Linked to original sources

PubMedDate not supplied

The next generation of liposome delivery systems: recent experience with tumor-targeted, sterically-stabilized immunoliposomes and active-loading gradients.

Three topics are discussed. Enhanced anti-tumor efficacy of targeted doxorubicin-containing sterically-stabilized liposomes using an anti-beta1 integrin Fab' ligand. Use of tumor targeting with an internalizing ligand to improve the efficacy of a non-leaky cisplatin-containing sterically-stabilized liposome formulation. Formulation variables (remote-loading with dextran ammonium sulfate, rigid lipid bilayer) used to optimize in vivo performance of a liposomal camptothecin analog.

Ammonium Sulfate↗

PubMedDate not supplied

Suppression of atherosclerosis in cholesterol-fed rabbits by diltiazem injection.

The effects of diltiazem, a calcium antagonist, on the development of atherosclerosis were studied in Japanese white rabbits. The rabbits were examined at the end of 10 weeks on the following regimens; a diet of standard pellets and daily intraperitoneal (ip) injections of saline; a diet of pellets containing 1% cholesterol and daily ip injections of saline; or a diet of pellets containing 1% cholesterol and daily ip injections of diltiazem (50 mg). The plasma total and LDL cholesterol levels for the third group were significantly lower than those of the cholesterol diet group. Macroscopically, atheromatous lesions covered 26.7% +/- 6.7% (mean +/- SE) of the intimal surface of the aorta in the second group, and 0.7% +/- 0.3% in the third group (p less than 0.005). The levels of cholesterol, calcium, and uronic acid in the aortic tissue of the second group were significantly higher than those in the third. We concluded that diltiazem administered intraperitoneally suppresses the plasma total and LDL cholesterol elevation induced by the cholesterol diet and inhibits experimentally-induced atherosclerosis.

Animals↗

PubMedDate not supplied

Methylenetetrahydrofolate reductase C677T is not associated with expression of pyrimidine metabolic enzyme genes in colorectal cancer.

Methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism may influence the chemosensitivity of colorectal cancers to fluorouracil (5-FU) by increasing intracellular 5,10-methylenetetrahydrofolate. The effect of this polymorphism on the expression of thymidylate synthase (TS), dihydropyrimidine dehydrogenase (DPD), orotate phosphoribosyl transferase (OPRT) and thymidine phosphorylase (TP) in colorectal cancer was investigated. The MTHFR C677T polymorphism was analysed and TS, DPD, OPRT and TP mRNA expression was measured in tumour and adjacent normal mucosal tissue. In all patients, the genotypes of the tumour and normal tissues were identical. No differences were found in the expression of TS, DPD or TP mRNA by genotype in either tumour or normal tissue. Although the OPRT mRNA level in tumour tissue was not associated with the genotype, normal mucosa with the TT genotype showed a significantly higher OPRT mRNA level than mucosa with other genotypes. The MTHFR C667T polymorphism is not associated with intratumoural expression of TS, DPD, OPRT or TP.

Aged↗

PubMedDate not supplied

Health benefits of rice bran oil.

Although scientific evidence is relatively limited, rice bran oil (RBO) is tenaciously believed to be a healthy vegetable oil in Asian countries. It exerts hypocholesterolemic activity in relation to more commonly used vegetable oils and is characterized by a relatively high content of non-fatty acid components, some of which are known to have beneficial health effects. Components specific for RBO such as gamma-oryzanol and tocotrienols could participate in its hypocholesterolemic effects. In addition, blending RBO with safflower oil, but not with sunflower oil, may magnify the hypocholesterolemic efficacy. This observation is of particular interest with regard to dietary intervention with RBO. The possible mechanism underlying this effect may at least in part be related to the specific triglyceride structure of safflower oil, differing from that of sunflower oil.

Animals↗

PubMedDate not supplied

Suppressive effect of sesamin against 7,12-dimethylbenz[a]-anthracene induced rat mammary carcinogenesis.

The effects of dietary supplementation of sesamin on 7,12-dimethylbenz[a]anthracene (DMBA)-induced mammary carcinogenesis in female Sprague-Dawley rats were studied. Experimental diets containing 0.2% sesamin (an equiweight mixture of sesamin and episesamin) or 0.2% alpha-tocopheryl acetate were given to rats starting 1 week before intragastric administration of DMBA (10 mg/rat). Sesamin significantly (p less than 0.05) reduced the cumulative number of palpable mammary cancers by 36% at 12 weeks post-DMBA administration compared with animals on a control diet. Alpha-tocopheryl acetate inhibited both the incidence and the cumulative number of mammary tumors by 20% and 45%, respectively. Concentrations of lipid peroxides in plasma, liver and tumors were all decreased in both sesamin and alpha-tocopheryl acetate groups. The activity of peripheral blood mononuclear cells (PBMC) increased in rats fed sesamin (140 to 150% of the control and alpha-tocopheryl acetate groups). Fatty acid compositions of plasma, liver and tumor phosphatidylcholine showed a decreased tendency of the metabolism of linoleic acid to arachidonic acid and hence of the plasma concentration of prostaglandin E2 in the sesamin group. The inhibitory effect of sesamin on DMBA-induced mammary carcinogenesis may be ascribed, at least in part, to immunopotentiation and increased antioxidative activity.

9,10-Dimethyl-1,2-benzanthracene↗

PubMedDate not supplied

Effects of dietary n-6/n-3 polyunsaturated fatty acid balance on tissue lipid levels, fatty acid patterns, and eicosanoid production in rats.

The effect of varying n-6/n-3 ratios (0.6-10.2) of dietary fats on various lipid parameters was examined in rats under a constant P/S ratio (1.4-1.5) with sardine oil as the source of n-3 polyunsaturated fatty acid (PUFA) by a combination of palm and safflower oils. The concentration of serum cholesterol tended to increase with n-6/n-3 of up to approximately 2, whereas aortic cholesterol decreased. The proportion of arachidonic acid in liver, heart, and aorta phosphatidylcholine increased linearly with increasing n-6/n-3 whereas that of linoleic acid reached a plateau at this ratio of approximately 4. The proportion of n-3 PUFAs decreased with increasing n-6/n-3 in tissue phosphatidylcholine. Although the production of prostacyclin (PGI2) by the thoracic aorta and thromboxane A2 (TXA2) by platelets increased with increasing n-6/n-3, TXA2/PGI2 was maintained at a low level up to n-6/n-3 of approximately 5. These results indicate that, when fish oil is the source of n-3 PUFAs, n-6/n-3 of 2-5 seems to be desirable for the various lipid parameters related to atherosclerosis and thrombosis.

Animals↗

PubMedDate not supplied

Effect of dietary fat and cholesterol on dimethylbenz[a]-anthracene-induced mammary tumorigenesis in Sprague-Dawley rats.

The effect of dietary fats and cholesterol on dimethylbenz[a]-anthracene-induced mammary tumorigenesis was studied in female Sprague-Dawley rats. When the dietary fat source (at the 5% level) was palm oil (saturated fat) or corn oil (unsaturated fat), dietary cholesterol at the 0.2% level increased the tumor number of rats fed corn oil, but not those fed palm oil. Perilla oil (rich in alpha-linolenic acid) reduced tumor development as compared with safflower oil (rich in linoleic acid), but again dietary cholesterol at the 0.5% level diminished the favorable effect of n-3 polyunsaturated fatty acid (PUFA). The adverse effect of cholesterol was also observed in the n-6 PUFA fat. The promotive effect of dietary cholesterol was not necessarily associated with the change in the production of prostaglandin E2 by the tumor tissue or in the immunopotentiation. These results at least stress that the contrasting effects of dietary fats should be carefully evaluated whether cholesterol is present simultaneously or not.

9,10-Dimethyl-1,2-benzanthracene↗

PubMedDate not supplied

Effects of intravenous perilla oil emulsion on nutritional status, polyunsaturated fatty acid composition of tissue phospholipids, and thromboxane A2 production in streptozotocin-induced diabetic rats.

The effects of a perilla oil (PO) emulsion rich in alpha-linolenic acid, administered by intravenous infusion, on nutritional status, fatty acid composition, and thromboxane A2 production were compared with those of a soybean oil (SO) emulsion in streptozotocin-induced diabetic rats given a fat-free diet for 7 days. The PO emulsion improved body weight gain and nitrogen balance compared with the SO emulsion and reduced thromboxane A2 production by platelets. The PO emulsion also increased the proportion of eicosapentaenoic acid, but decreased that of arachidonic acid, in liver and serum phospholipids. Plasma insulin concentrations and blood biochemical indices were similar in the two groups. An intravenously infused PO emulsion effectively reduces thromboxane A2 production through changes in the fatty acid composition of liver and serum phospholipids, as with oral administration, and improves the nutritional status of diabetic rats.

Animals↗