Decreased IL-4 production in new onset type I insulin-dependent diabetes mellitus.

IL-4 has been shown to protect against diabetes development in rodent models of insulin-dependent (type I) diabetes mellitus (IDDM). To study IL-4 production in human IDDM, PBMC from IDDM patients and controls were stimulated in vitro with PHA, anti-CD3 mAb, or PMA and ionophore. IL-4 production by PBMC or T cells was strongly impaired in IDDM patients at diabetes onset (p < 0.

Effect of aging and caloric restriction on intestinal permeability.

Intestinal permeability is increased in several disorders such as Crohn's disease or rheumatoid arthritis. Since aging leads to alteration of many biological functions, the effect of aging on intestinal permeability was studied by measuring the intestinal permeability in aging rats gavaged with different size permeability probes--mannitol, polyethylene glycol (PEG) 400, and inulin. In rats fed with control diet, there was a significant increase in intestinal permeability to medium size probes PEG 400 (14.

Polyethylene glycol 400 penetration of the colonic epithelial barrier of the rat.

Permeability changes of polyethylene glycol 400 have been seen in patients with inflammatory bowel diseases. Because the colon can be involved in inflammatory bowel disease, the mechanisms, kinetics, and influence of intraluminal factors on polyethylene glycol 400 permeation of perfused colonic segments of rats were studied. The absorption rate of polyethylene glycol 400 was linearly related to its luminal concentration (r = 0.

Regulation of polyethylene glycol 400 intestinal permeability by endogenous and exogenous prostanoids. Influence of non-steroidal anti-inflammatory drugs.

Polyethylene glycol 400 (PEG 400) is a clinically useful intestinal permeability probe whose rate of intestinal permeation is influenced in part by solvent drag. As mucosal prostanoids are increased in inflammatory bowel disease and affect water transport we examined the possible relationship between prostaglandin E2 (PGE2) and the inhibitors of endogenous prostaglandins--the non-steroidal anti-inflammatory drugs (NSAIDS)--on PEG 400 absorption in vivo using segmental perfusion of rat small intestine. We found that the addition of exogenous PGE2 in concentrations of 0.

Influence of aging on vitamin A transport into the lymphatic circulation.

Vitamin A is a lipid soluble essential dietary micronutrient. Because aging individuals have elevated serum levels of vitamin A, we tested the intestinal absorptive capacity of the vitamin in aging rats by measuring the appearance rate of vitamin A in the lymphatic circulation as a measure of intestinal absorption. We infused the vitamin in a physiological concentration of 350 nM into the proximal jejunum of groups of Sprague-Dawley rats 2 to 23 months of age.