[Assessment of the effect of selected mixture of food additives on the protein metabolism--model studies]. / Ocena wplywu mieszaniny wybranych dodatków do zywnosci na wskazniki metabolizmu bialkowego--badania modelowe.

BACKGROUND: Contemporarily, food production without food additives is very rare. Increasingly often, however, scientific works report on adverse effects of specified, single food additives on the body. Data is, in turn, lacking on the synergistic effect of a mixture of different food additives on body functions and its main metabolic pathways. OBJECTIVE: The objective of this study, an animal model, was to evaluate if and in what way the compound of chosen and most frequently used and consumed food additives, along with the change of diet composition to processed, purified, influence the selected markers of protein metabolism. MATERIAL AND METHODS: The animals were divided into four groups, which were fed with compound of feed pellets: group I and II with basic compound, group III and IV with modified compound in which part of the full grain was replaced by isocalorie wheat flour type 500 and saccharose. Animals from groups I and III received tap water, which was standing for some time, to drink. Animals from groups II and IV received solution of chosen additives to food and next they were given water to drink. The amount of given food additives was evaluated by taking into consideration their consumption by people recalculated to 1 kg of their body mass. The experiment spanned for 7 weeks. RESULTS: It was ascertained that the applied additives caused significant changes in total protein concentration and its fractions: albumin, alpha1-globulin, alpha2-globulin, beta-globulin and gamma-globulin in the blood serum of the animals under research, which can indicate and contribute to disclosure of creation of undesirable food reaction, especially when recommended levels of consumption of those additives are being exceeded. The organism response to the applied additives and accompanying it change of diet was essentially connected to sex of the animals. Undesirable character of changes taking place under the influence of applied additives, was observed both in animals fed with basic feed and modified feed with various intensity according to the parameter under research. CONCLUSIONS: The analysis of the results achieved enabled concluding that the applied mixture of food additives caused significant changes in the concentration of total protein and its fractions: albumins, alphal-, alpha2-, beta- and gamma-globulins in blood serum of the investigated animals. These changes may indicate but also may contribute to the development or manifestation of undesirable nutritional responses, especially when recommended dietary allowances are exceeded. The body's response to the applied additives and concomitant modification of diet composition was significantly correlated with sex of the animals. The unfavorable character of changes following the administration of additives was observed in both the animals on the basal diet and these fed the modified feed mixture, yet with a different intensity that was found to depend not on the feeding group but on the parameter examined.

Thalidomide induces gamma-globin gene expression through increased reactive oxygen species-mediated p38 MAPK signaling and histone H4 acetylation in adult erythropoiesis.

Although thalidomide has been shown to improve anemia in some patients with myelodysplastic syndromes and stimulates erythropoietin in patients with multiple myeloma, thalidomide's specific effects on gamma-globin gene expression during erythroid differentiation have not been studied. Here, we investigated the effects of thalidomide on gamma-globin gene expression and the involved signaling pathway using an ex vivo culture system of primary human CD34+ cells. We found that thalidomide induced gamma-globin mRNA expression in a dose-dependent manner, but had no effect on beta-globin expression. We also demonstrated that intracellular reactive oxygen species (ROS) levels were increased by treatment with thalidomide for 48 hours (from day 3 to day 5). Western blot analysis demonstrated that thalidomide activated the p38 mitogen-activated protein kinase (MAPK) signaling pathway in a time- and dose-dependent manner and increased histone H4 acetylation. Pretreatment of cells with the antioxidant enzyme catalase and the intracellular hydroxyl scavenger dimethylthiourea (DMTU) abrogated the thalidomide-induced p38 MAPK activation and histone H4 acetylation. Moreover, pretreatment with catalase and DMTU diminished thalidomide-induced gamma-globin gene expression. These data indicate that thalidomide induces increased expression of the gamma-globin gene via ROS-dependent activation of the p38 MAPK signaling pathway and histone H4 acetylation.

Blood protein reactions to ablation of capsaicin-sensitive neurons.

The effects of ablation of afferent neurons with neurotoxic doses of capsaicin (150 mg/kg) on protein levels in plasma fractions were studied by polyacrylamide gel electrophoresis in Wistar rats at different times points after administration of capsaicin and in inflammatory reactions induced by zymosan (10 mg/100 g). Administration of neurotoxic doses of capsaicin induced biphasic changes in protein levels in plasma fractions. During the initial period (up to seven days), "acute-type" changes in protein content were seen; at 11-30 days, there were chronic increases in the albumin level with decreases in alpha(1), alpha(2), and gamma globulins. Defunctionalization of capsaicin-sensitive nerves 14-30 days before induction of inflammation prevented the "acute-phase" changes in protein contents in the albumin, alpha(1), alpha(2), and beta globulin fractions in response to induction of inflammation with zymosan.

Empiric therapy of autoimmune hepatitis with mycophenolate mofetil: comparison with conventional treatment for refractory disease.

GOAL: To assess the outcomes of empiric therapy with mycophenolate mofetil in patients with autoimmune hepatitis. BACKGROUND: Mycophenolate mofetil is a purine antagonist that selectively inhibits immunocyte proliferation, and its empiric use in autoimmune hepatitis has been stimulated by small clinical experiences. STUDY: Eight patients received mycophenolate mofetil (0.5-3 g daily) for 19 +/- 7 months as frontline therapy or after adverse responses to conventional corticosteroid treatment. Seventeen patients who had been treated with high-dose corticosteroid regimens after treatment failure constituted a historical comparison population. RESULTS: Five of the 8 patients receiving mycophenolate mofetil and all 17 patients who had been treated with the conventional corticosteroid regimens for treatment failure responded to therapy. The frequency of response (62% vs. 100%, P = 0.02) was lower during longer intervals of treatment (19 +/- 7 months vs. 6 +/- 1 months, P = 0.02) in the patients receiving mycophenolate mofetil. None receiving mycophenolate mofetil resolved their laboratory abnormalities, whereas 6 patients in the comparison group improved to normal tests (0% vs. 35%, P = 0.1). Histologic resolution did not occur in 4 patients sampled during treatment, and successive specimens in 2 patients showed progressive fibrosis. Corticosteroids could not be withdrawn in the patients treated with mycophenolate mofetil, whereas discontinuation was possible in 7 patients in the comparison group (0% vs. 41%, P = 0.06). CONCLUSIONS: Mycophenolate mofetil did not induce laboratory resolution, prevent progressive fibrosis, or allow corticosteroid withdrawal. Clinical trials are needed to evaluate its role and target population.

[The effect of an oral zinc substitution on some biochemical blood serum parameters in pregnant sheep and their lambs as well as on the birth weights of the lambs]. / Auswirkungen einer oralen Zinksubstitution auf einige biochemische Serumparameter bei trächtigen Schafen und deren Lämmern sowie auf die Geburtsgewichte der Lämmer.

The aims of this study were to demonstrate the effects of zinc sulphate administration (2 g/week p.o., 2% solution) on zinc, copper, iron, calcium and magnesium levels in blood serum of 20 pregnant Ivesi sheep during the last 2 month of pregnancy, immediately post partum as well as in their newborn lambs. In these 20 lambs, also total serum protein, gamma globulin and birth weight were determined. The control group consisted of 15 pregnant sheep and their 15 lambs housed under the same conditions. Zinc sulphate administered to sheep caused significant increases in their serum levels of zinc as well as in those of their lambs. The lambs of the zinc supplemented group had also slightly higher birth weights (not significant) and significant higher gamma globulin levels, whereas the total protein values was almost identical in both groups.

A combination of hydroxyurea and isobutyramide to induce fetal hemoglobin in transgenic mice is more hematotoxic than the individual agents.

Pharmacologic agents such as hydroxyurea (HU), N, 3-4 trihydroxybenzamide (didox), and isobutyramide (ISB) can elevate gamma-globin as a potential treatment for the beta-hemoglobinopathies. In these experiments, transgenic mice with 5'HS2 from the human beta-globin locus control region, the fetal (A gamma), and adult (beta s) globin genes were used. Mice were treated with HU, didox, or ISB individually, or with combinations of HU or didox with ISB. The aim was to determine whether these drugs have synergistic effects on the induction of fetal hemoglobin (HbF) and whether the combination regimens are more hematotoxic. In the combination regimens, injections of HU or didox for five weeks were concomitant with ISB treatment every other day for the final three weeks of treatment. The combination of HU + ISB was more hematotoxic than the individual drugs based on significantly increased percentages of reticulocytes and reduced hemoglobin, indicating that caution should be taken in treatments involving combinations of these types of drugs. The didox + ISB combination was not more hematotoxic than the individual drugs. HbF was not induced in the groups treated with the combinations of HU or didox with ISB compared to the individual agents. There was a negligible effect on the percentage of HbF and an unexpected negative effect on the percentage of F cells. The results also have implications for future testing of HbF-inducing drugs in mouse models. In control mice that were phlebotomized but not treated with any drugs, increased percentages of F cells were observed, indicating that blood sampling can cause this effect. In addition, increases in the percentage of F cells did not correlate with increases in the percentage of HbF, indicating that monitoring F cells alone is not a sufficient measure of HbF induction.

Damage of amino acids and proteins induced by nitrogen dioxide, a free radical toxin, in air.

Damage of amino acids and proteins induced by nitrogen dioxide, a free radical toxin in polluted air, was investigated. When nitrogen dioxide (30-90 ppm) in air was exposed to a solution of an amino acid at pH 7.5 for several hours, tryptophan and tyrosine were damaged. Degradation of tryptophan was accompanied by formation of a nitroindole derivative. Decrease of tyrosine was accompanied by formation of 3-nitrotyrosine and fluorescent dityrosine. When nitrogen dioxide was exposed to a solution of bovine serum albumin, human gamma-globulin and bovine eye lens alpha-crystallin, the proteins were crosslinked by nondisulfide bonds. Tryptophan and tyrosine residues in the proteins were extensively decreased, and significant amounts of 3-nitrotyrosine and fluorescent dityrosine were formed. The modification of the proteins with nitrogen dioxide in air may have toxicological significance. Because fluorescent dityrosine is detected in a wide variety of natural proteins, nitrogen dioxide may play a role in its occurrence in natural proteins.

Studies on eye irritation caused by chemicals in rabbits--II. Structure-activity relationships and in vitro approach to primary eye irritation of salicylates in rabbits.

Structure-activity relationships and in vitro evaluation of eye irritation potential of salicylates in rabbits were studied. The primary eye irritation potential of ten salicylates was evaluated according to Draize method. The effects of chemicals on model protein and lipid were investigated in vitro. The effects of chemicals on the protein could be detected by the production of aggregates of human serum gamma-globulin (HSG) and a good correlation was obtained between the ability of salicylates to produce aggregation of HSG and the potential of corneal irritation. The effects on the lipid could be detected by the adhesion potential of chemicals on lipid membrane and a linear correlation was not obtained between the adhesionary effects of salicylates on lipid membrane and the potential eye irritation. The corneal irritation and protein aggregation potential of salicylates were correlated with the acid dissociation constant more closely than octanol/water partition coefficient. The destruction of alpha-helix of proteins in corneal surface by salicylates were observed from the nondestructive structural analysis of corneal surface by Fourier Transform (FT)-IR spectroscopy. These results suggest that eye irritation caused by salicylates are mainly the results of denaturation of proteins in ocular tissue and that the effects on protein depend on the dissociation potential of molecules.