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Biomedical subjects

H Buchwald

Publications and source records attributed to H Buchwald.

At least 109 records · Page 6Linked to original sources

Positive results of jejunoileal bypass surgery: emphasis on lipids with comparison to gastric bypass.

The positive results of jejunoileal bypass are briefly reviewed: significant weight reduction, lowering of blood pressure, mitigation of diabetes, improved physical functions, amelioration of osteoarthritis and thrombophlebitis, and improved self-esteem and socialization. A major benefit of jejunoileal bypass is the marked and permanent plasma cholesterol and triglyceride reductions. At one year plasma cholesterol is reduced 42 percent, with plasma triglyceride lowered 35 percent. In a comparable series of gastric bypass patients one year after operation, the plasma triglyceride lowering was identical at 35 percent; however, the plasma cholesterol reduction was only 14 percent. Although we currently perform mostly gastric bypasses as the primary metabolic operation for morbid obesity, we believe the jejunoileal bypass should not be discarded from the armamentarium of the surgeon committed to the treatment of this malignant disease.

Adolescent↗

Reduced apoprotein B and increased lipoprotein turnover in cholesterol-fed rabbits after partial ileal bypass.

Plasma lipid and lipoprotein levels and composition of the very low-, low-, and high-density lipoproteins (VLDL, LDL, HDL) were studied in white New Zealand rabbits in the control state, 8 weeks after initiation of a 2% cholesterol-enriched diet, and sequentially for 16 weeks following a partial ileal bypass (PIB) procedure. Turnover and aortic uptake of 125I-labeled VLDL, obtained from the rabbits before and 16 weeks after PIB, were also analyzed. A significant reduction of plasma cholesterol from the postdiet levels to well below the prediet mean, despite continuation of the high cholesterol diet, followed PIB. A very early reduction of the apoprotein B percentage content in both VLDL and LDL was observed after the procedure, even when a relative cholesterol ester enrichment of these lipoproteins was still present. HDL cholesterol levels were somewhat lowered by the experimental diet and further reduced after PIB. 125I-labeled VLDL after PIB showed a reduced arterial uptake, as compared to the same lipoproteins from animals before PIB. These findings may provide an interpretation for the decreased atherogenesis after PIB.

Animals↗

Intraarterial infusion chemotherapy for hepatic carcinoma using a totally implantable infusion pump.

Intraarterial infusion chemotherapy has several theoretical advantage over conventional therapy for the treatment of unresectable malignancies. However, the catheter problems and patient restriction to the hospital associated with its use have resulted in infrequent application and a notable lack of progress in this field of oncology. This paper describes the use of a totally implantable, percutaneously refillable infusion pump in 5 patients with primary or metastatic carcinoma of the liver. The infusion cannulae were placed into the hepatic arteries under direct vision at laparotomy, and the pumps were placed in subcutaneous pockets. Four patients received infusions of 5-fluorodeoxyuridine at rates of 0.2-0.5 mg/kg/day for periods of three to 29 weeks; the pump in the fifth patient was defective and was removed. The implanted pumps were well tolerated in these subjects, who received chemotherapy as outpatients; the only adverse effects noted were related to FUDR toxicity. This implantable infusion pump appears to be a practical means of delivering long-term intraarterial infusion chemotherapy to outpatients.

Antineoplastic Agents↗

The effect of partial ileal bypass on plasma lipoproteins.

Plasma lipids and lipoprotein cholesterol concentrations were determined before and at 3 months and 1 year after partial ileal surgery in 28 male survivors of first myocardial infarction (eight normolipidemic subjects and eight type II-A, two type II-B, eight type IV and two type V hyperlipoproteinemic subjects). All subjects had marked reductions in plasma total cholesterol (average 45% and 33% in the type V subjects and 37% and 31% in the other 26 subjects at 3 months and 1 year after surgeryyy). Except for the two type V subjects, all had even more marked reductions in low-density lipoprotein (LDL)-cholesterol than in the total plasma cholesterol, averaging 51% at 3 months and 49% at 1 year after surger. There were no significant changes in high-density lipoprotein (HDL)-cholesterol levels. The hypertriglyceridemic subjects had marked reductions in plasma triglycerides and very low density lipoprotein-cholesterol, whereas the normotriglyceridemic subjects (normals and II-A) had slight increases in these two measurements after surgery. Partial ileal bypass tends to normalize elevated plasma lipid and lipoprotein levels and results in a maximal lowering in LDL-cholesterol concentrations without altering the HDL-cholesterol level.

Adult↗

Colonic conservation of malabsorbed carbohydrate.

[14C]Sucrose absorption was studied in 4 healthy controls and 4 patients after jejunoileal bypass using an ileal perfusion technique which made it possible to distinguish 14C-absorption in the small bowel from that occurring in the colon. Healthy controls failed to absorb 2--4% of a 50-g dose of [14C]sucrose in the small bowel; however, virtually none of the [14C] appeared in feces in a dialyzable form with appreciable osmotic activity. In bypass patients, the small bowel failed to absorb 29--84% of the 50-g dose of [14C]sucrose. Approximately two-thirds of the nonabsorbed [14C] was in the form of sucrose and the remainder was nearly all present as monosaccharides. A mean of only 42% of the [14C] Not absorbed in the small bowel appeared in the feces and only about one-third of this fecal [14C] was in a dialyzable form with appreciable osmotic activity. Thus, the colon plays an important role in carbohydrate malabsorption by salvaging carbohydrate and reducing osmotic activity of the nonabsorbed sugar. This conlonic function appears to depend upon bacterial metabolism of the carbohydrate, and individual variations in diarrhea and weight loss associated with carbohydrate malabsorption could reflect individual differences in the bacterial flora of the colon.

Adult↗

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↗

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↗