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Biomedical subjects

I J Guzman

Publications and source records attributed to I J Guzman.

14 recordsLinked to original sources
PubMed1980

Combined hypolipidemia of portacaval transposition and ileal resection in the dog.

The effects of portacaval transposition in combination with exclusion of the distal part of the intestine upon the plasma cholesterol and triglyceride levels was studied in dogs. The dogs tolerated distal intestinal resection, portacaval transposition and their combination well; survival and weight maintenance probably being superior to that of dogs having a standard end-to-side portacaval shunt. Plasma triglyceride levels significantly decreased after portacaval transposition and after intestinal resection; an additional and significant lowering of triglyceride levels was observed after a combination of these procedures. Portacaval transposition significantly lowered the plasma cholesterol level of dogs given a normal chow diet but did not protect them from diet-induced hypercholesterolemia. Distal intestinal resection did not significantly lower the plasma cholesterol level of nonhypothyroid, normocholesterolemic dogs fed regular chow but did protect them from dietary hypercholesterolemia. Portacaval transposition plus intestinal resection demonstrated the addition of these effects upon the plasma cholesterol level. The combination of a portal diversion operation and an intestinal exclusion procedure may provide a synergistic approach to lipid reduction.

Animals↗
PubMed1980

Retarding Novikoff tumor growth by altering host rat cholesterol metabolism.

Tumor cells, in vitro, must derive the majority of their required cholesterol from their host milieu. To determine if limiting tumor-available cholesterol results in limited tumor growth in vivo, Holtzman rats were given 10 X 10(6) Novikoff ascites tumor cells subcutaneously. Prior to inoculation, animals received either distal small bowel exclusion or sham operation plus either standard chow or estrone-containing chow (0.0025% or 0.01%) diets. In three separate experiments it was shown that (1) tumor weight was positively correlated with whole plasma cholesterol levels (r = 0.495; P less than 0.05); (2) the lowest tumor weights were correlated with the lowest plasma cholesterol; (3) low density and very low density lipoprotein cholesterol levels were both individually and in combination positively correlated with tumor weight (R2 = 0.828; P less than 0.01); and (4) survival of subcutaneous tumor inoculated animals was significantly greater in those animals shown to have the lowest plasma cholesterol, 27 +/- 1 days versus 29 +/- 1 days; (P less than 0.05). These data support the concept that limiting tumor-available cholesterol by altering host cholesterol metabolism will limit tumor growth.

Animals↗
PubMed1979

Increased hepatic cholesterol synthesis in normal rats by cross-circulation with ileal bypassed partners.

Aortic cross-circulation between Holtzman rat littermates was employed to investigate the possible role of a blood-borne factor from the small intestine in the regulation of hepatic cholesterol synthesis. Experimental pairs, consisting of a normal rat and a distal 50% small bowel excluded partner, demonstrated significantly increased combined hepatic cholesterol synthesis when compared to control pairs, consisting of two normal rats, both at 3 and 5 days following parabiosis. This difference was accounted for by increased hepatic cholesterol synthesis in the normal rat in each experimental pair. Neither weight loss nor differences in dietary intake contributed to this effect. Whole blood cholesterol in the common circulation of both experimental and control pairs was lowered; while hepatic cholesterol content was transiently increased, at 3 but not 5 days following parabiosis. Thus, the intestinal bypassed rat stimulates, or releases inhibition of, hepatic cholesterol synthesis in a non-bypassed parabiotic partner. The mechanism for this phenomenon has yet to be defined.

Acetates↗
PubMed1979

Cholesterol pool sizes and turnover following portacaval shunt in the dog.

Portacaval shunt has been shown to be effective in lowering the plasma cholesterol level of both man and experimental animal. However, the primary mechanism which effects this reduction is unclear. We have measured the rapidly, and the slowly, miscible cholesterol pool sizes and the cholesterol production rate in mongrel dogs, with the animals in the cholesterol steady state, using 14C-cholesterol plasma decay curve analysis. Five control animals and three one year postoperative portacaval shunt animals with a 50 per cent plasma cholesterol level reduction were studied. No differences were demonstrated in either the cholesterol pool sizes or the production rate. These data have led us to postulate two hypotheses to explain the mechanism of the hypocholesterolemic effect of the portacaval shunt.

Animals↗
PubMed1978

Benign tumors of the liver. Pathologic examination of 45 cases.

The histologic and clinical features of 45 benign tumors of the liver (excluding hemangiomas) were reviewed. They included 21 cases of focal nodular hyperplasia, 11 cases of hepatic cell adenoma, 12 cases of bile-duct adenoma and a single case of mesenchymal hamartoma. By adhering to published histologic criteria, the cases of focal nodular hyperplasia and hepatic cell adenoma could be readily separated. Although both focal nodular hyperplasia and hepatic cell adenoma occurred predominantly in women, focal nodular hyperplasia occurred at a greater mean age, was usually asymptomatic, and the lesions tended to be smaller (surgical cases) than hepatic cell adenoma. The latter usually were symptomatic. It is emphasized that focal nodular hyperplasia and hepatic cell adenoma are distinct lesions and are separable on histologic grounds. Although the names focal nodular hyperplasia and hepatic cell adenoma are retained, the authors cannot assert that one lesion is a neoplasm, the other a reactive condition, and prefer, instead, to leave this question unresolved.

Adenoma, Bile Duct↗
PubMed1977

Small bowel length in hyperlipidemia and massive obesity.

Small bowel length has been measured during intestinal bypass surgery in 272 morbidly obese patients undergoing jejunoileal bypass and 121 nonobese patients undergoing partial ileal bypass for hyperlipidemia. There was no statistically significant difference in small bowel length between the obese and the nonobese patients. Small bowel length was not correlated with the degree of obesity expressed as the percentage of ideal weight. The only statistically significant correlation determined was between sex and bowel length in the obese subjects, where a greater length of small intestine was found in the males.

Adult↗