John A. Balint

Adaptive changes of the rat small intestine in response to a high fat diet

Abstract 1. 1. Rats exposed to increased dietary lipid were studied for evidence of adaptive changes in the small intestine. Two experimental groups were used. One was fed regular chow supplemented to 20% lipid with additional lard. The other was fed a synthetic diet with a similar lipid but a greater carbohydrate content and devoid of fibrous filler. 2. 2. After four weeks fecal fat output was determined. Absorption of oleate was also studied by the everted sac technique and assays of one of the mucosal lipid re-esterifying enzymes were performed. 3. 3. Rats on a high fat diet excreted significantly less radioactive fat in feces. Sacs from the jejunum of these animals absorbed more oleic acid than controls. The same trend was observed in the ileum but this was of greater significance in ileal sacs from rats on the synthetic diet. Enzyme content in the jejunum was the greatest in rats on regular chow supplemented with lard while in the ileum the highest levels were found in animals on the synthetic high fat diet. 4. 4. It is concluded that the small intestine adapts to increased dietary lipid. Other components of the diet, however, can influence the site at which these adaptive changes occur.

The entry of choline into lecithin, in vivo, by base exchange

Abstract 1. 1. After intravenous administration to bile-cannulated male rats of 32 Pi, [ Me - 3 H]choline and [ Me - 14 C]methionine simultaneously, the specific activities were determined of free choline, phosphorylcholine, CDP-choline, sphingomyelin and also of linoleoyl and arachidonoyl lecithins of both bile and liver at intervals up to 6 h. 2. 2. The ratio of 73 H/ 32 P of lecithins was much higher than that of phosphorylcholine indicating that free choline enters lecithins by base exchange. The rate of base exchange was estimated at about 4 times the rate at which phosphorylcholine is converted to lecithin. 3. 3. The low specific activity of CDP-choline in respect of choline observed by BJ0RNSTAD and Bremer is confirmed. A high ratio of 3 H/ 32 P and 14 C/ 3 H in CDPcholine compared to phosphorylcholine and a high specific activity ( 32 P) of the CMP portion of CDP-choline confirms their suggestion of a phosphorylcholine transferase catalyzed exchange, CDP-choline and diglyceride lecithin and CMP. 4. 4. Because of rapid base exchange, estimates of the rate of phospholipid turnover based upon radioactive lipid bases are probably too high.

Effects of Changes in Dietary Lipids on Intestinal Fluid Loss in the Short-Bowel Syndrome

Abstract Seven patients underwent massive intestinal resection. Fecal losses of water and electrolytes were life threatening in four patients, who required constant or repeated intravenous replacem...

Alterations in phosphatidylcholine species and their reversal in pulmonary surfactant during essential fatty-acid deficiency.

Previous studies (Kyriakides, E.C., Beeler, D.A. and Balint, J.A. (1974) Clin. Res. 22, 717a, and Burnell, J.M. and Balint, J.A. (1975) Fed. Proc. 34, 426) have indicated that essential fatty-acid deficiency in rats resulted in significant reduction of palmitate content of lung tissue and lavage phosphatidylcholines. Experiments were, therefore, undertaken to confirm and further characterize these changes and to examine the reversal of these alterations when essential fatty acid deficient rats were fed fat-free diets supplemented with linoleate for 1-14 days. Analysis of the fatty acid composition of liver lipids was used to confirm the presence of essential fatty-acid deficiency in rats that were fed a fat-free diet supplemented with 4% by weight of tripalmitoylglycerol for 14 weeks. Phosphatidylcholines from lung tissue and lavage fluid of essential fatty-acid deficient rats contained significantly less palmitate and significantly more palmitoleate and oleate than those rats receiving linoleate. These changes in fatty acid composition were reflected in a significant reduction of disaturated phosphatidylcholines (predominantly dipalmitoyl) in lung tissue and lavage fluid from essential fatty-acid deficient rats, while the total phosphatidylcholine content remained unchanged. On feeding the diet containing linoleate to the deficient rats, a reversal of these changes began after one day and was nearly complete by 7-14 days.

Primary leiomyoma of the liver. A case report and review of the literature

SummaryThe fourth known case of primary leiomyoma of the liver is described. This diagnosis depends on the exclusion of leiomyoma at other intraabdominal sites and careful histologic review to exclude malignant change. In the presented case, multiple noninvasive imaging modalities failed to allow a tissue specific diagnosis, although magnetic resonance imaging of the liver did add useful information. For this problem, hepatic lobectomy is both diagnostic and curative.

The relationship of fatty acid composition and surface activity of lung extracts.

Male weanling rats were fed fat-free diets supplemented with 4% (w/w) safflower oil (control) or 4% tripalmitin (essential fatty acid (EFA) deficient) for 14 weeks. Whereas the amount of lecithin in lung lavage material remained unchanged, lung lavage lecithin from EFA-deficient rats contained significantly less palmitic acid (61.4 +/- 2.0% vs. 77.4 +/- 5.8%, P less than 0.01) than that from controls. Surface tension vs. area hysteresis loops were obtained for total lipid extracts (TLE) of lung lavage fluid, intra- and extra-cellular lipoprotein fractions (IBI and IBE) and lipid extracts of those lipoprotein fractions (LBI and LBE). A significant increase in minimal surface tension (gammamin) was found for all samples obtained from EFA-deficient rats as compared to controls. Refeeding of diets containing safflower oil for 7-14 days reversed these changes. Air pressure-volume curves on degassed, excised lungs indicated that greater pressure is required to maintain a given lung volume in EFA-deficient rats. These results support the hypothesis that the fatty acid composition of pulmonary surfactant lecithins is a major determinant of the surface activity of lung extracts.

The absorption and subsequent utilization of lecithin by the rat jejunum

Labeled lecithin (32P, 2-3H-glycerol, 1-14C-palmitate) was prepared for studying absorption of lecithin by rat intestine and its incorporation into microsomal and prechylomicron-chylomicron lecithin. Bile fistula rats were perfused intraduodenally with bile salts and lecithin plus a liquid diet. Intestinal samples were obtained after sacrifice and specific activities (DPM/μmol) of isotopes in lecithin were determined. Ratios of specific activities of isotopes were calculated and compared to respective ratios in the original perfusate lecithin. Radioactivity rapidly appeared in jejunal lecithin following perfusion. When specific activities of isotopes in prechylomicron-chylomicron lecithin were compared to those in microsomal lecithin, specific activities were always greater in prechylomicron-chylomicron lecithin. Analysis of ratios of specific activities of isotopes in jejunal lecithin showed that the ratios were nearly identical to those in perfusate phospholipid, indicating that the lysolecithin portion of luminal lecithin can be absorbed intact and can then be utilized for jejunal lecithin synthesis.Labeled lecithin (32P, 2-3H-glycerol, 1-14C-palmitate) was prepared for studying absorption of lecithin by rat intestine and its incorporation into microsomal and prechylomicron-chylomicron lecithin. Bile fistula rats were perfused intraduodenally with bile salts and lecithin plus a liquid diet. Intestinal samples were obtained after sacrifice and specific activities (DPM/μmol) of isotopes in lecithin were determined. Ratios of specific activities of isotopes were calculated and compared to respective ratios in the original perfusate lecithin. Radioactivity rapidly appeared in jejunal lecithin following perfusion. When specific activities of isotopes in prechylomicron-chylomicron lecithin were compared to those in microsomal lecithin, specific activities were always greater in prechylomicron-chylomicron lecithin. Analysis of ratios of specific activities of isotopes in jejunal lecithin showed that the ratios were nearly identical to those in perfusate phospholipid, indicating that the lysolecithin portion of luminal lecithin can be absorbed intact and can then be utilized for jejunal lecithin synthesis.

The effects of medium-chain triglycerides in the short bowel syndrome. Increased glucose and water transport.

Three patients suffering from short bowel syndrome with excessive fecal fluid loss in tenuous fluid, electrolyte and nutritional state were studied. Addition of medium-chain triglycerides (MCT) to a low-fat diet caused marked clinical improvement; a positive nutritional balance and decreased fecal fluid loss resulted. Medium-chain triglycerides failed to facilitate glucose, water or sodium transport by themselves. Improvement in glucose and water transport, however, was found at the time general clinical improvement occurred after treatment with MCT. Improved absorption may be secondary to the better nutritional state of the patients.

Five years of complete remission of gastric diffuse large B cell lymphoma after eradication of Helicobacter pylori infection

Long term follow up data are not available for cases of diffuse large B cell gastric lymphoma treated by eradicating Helicobacter pylori alone. We present the case of an 82 year old man with diffuse large B cell lymphoma localised to the stomach which responded to H pylori eradication and which has not recurred after more than five years of close follow up. Our patient was not a candidate for other modalities of treatment. This case demonstrates that the option of treating H pylori infection as the initial trial of treatment for localised diffuse large B cell lymphoma is appropriate for consideration. If medical therapy using eradication of H pylori is used, it is essential that the patient undergoes close observation and repeated surveillance endoscopies.

Inhibition of pentagastrin-stimulated gastric secretion by duodenal acidification or administration of fat in normal subjects and in patients with duodenal ulcer

The inhibitory effect of duodenal acidification and intraduodenal fat infusion on pentagastrin-stimulated gastric secretion in normal subjects and in patients with duodenal ulcer was studied. Intraduodenal infusion of acid resulted in inhibition of HCl secretion found to be significant only in ulcer patients. Pepsin output, although lower during the first 15 minutes of duodenal acidification, later increased. Intraduodenal infusion of olive oil resulted in significant inhibition of HCl and pepsin output in both groups of patients, which was maximal 45–60 minutes after the beginning of fat infusion. Gastric secretion was more readily inhibited in ulcer patients than in normal subjects; this difference was particularly evident in inhibition of pepsin secretion. In addition, decrease in concentration of HCl and pepsin was observed to be significant only in ulcer patients. Mechanisms by which duodenal acidification and fat inhibit gastric secretion are discussed. The results obtained suggest that secretin, which is probably responsible for inhibition after duodenal acidification, is not the inhibitor during inhibition by fat. The ulcer patients were found to have unimpaired mechanisms of inhibition by acid and fat.