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Five isolates of Leishmania tropica from southwest Iran were studied to identify correlates among human disease, animal infectivity, and surface biochemistry. Clinical patterns of the disease in humans differed. One striking strain, LT-249, produced a small dry lesion which did not heal during four years of observation. Infectivity of these L. tropica for mice was correlated with lectin agglutination patterns and interaction with macrophages. There was also a significant difference among the five isolates regarding infectivity for BALB/c mice; isolate LT-249 was not infective whereas all the others were. All isolates agglutinated with Concanavalin A (Con A), Ricinus communis and soybean agglutinin but not with four other lectins listed. However, Leishmania isolate LT-249 showed much poorer agglutination with all lectins than did the other four isolates. Two isolates were selected for detailed study of attachment to macrophages, one, LT-249, which was not infective and one, LT-252, which was infective for BALB/c mice. The number of promastigotes which attached to macrophages in vitro was the same, but the mechanism of attachment differed since only the LT-252 bound predominantly by Con A-mannose receptor interaction. These results indicate a correlation among animal infectivity, lectin agglutination, and promastigote-macrophage attachment. In particular one isolate of L. tropica which caused prolonged infection in humans was not infective in BALB/c mice, showed poor agglutination with lectins, and bound to macrophages by a different mechanism than did other isolates from the same region.

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This study investigated the effects of aflatoxin B1 (AFB1) and milk thistle seed (MTS) on some apparent ileal morphology and digestibility variables in the small intestines of broilers. A total of 216 Ross 308 male broiler chickens were allocated in a 3 3 factorial arrangement of the treatments with three concentration of AFB1 (0, 250, and 500 ppb) and three levels of MTS (0, 5, and 10 g kg -1 ). On day 35, the birds that received diets with 500 ppb of AFB1 alone (main effect) showed significant decrease in apparent ileal digestibility [dry matter (DM; 72.46±0.27) and ratio of VL to crypt depth (VL/CD; 4.74±0.07)] in their ileum segments (P<0.01). However, the mean nitrogen (N; 61.39±0.48) and crypt depth (CD; 173.5±9.87), in the ileum were significantly greater for the birds that were fed with 500 ppb AFB1 alone in their diets when compared with the control (P<0.01). Also, thistle seeds can ameliorate the toxic effects of AFB1 on some ileal digestibility factors, that is, DM, N, Ca, and CP, in broiler chicks. Nevertheless, ileum morphology of VW and goblet cell numbers were not affected negatively by the AFB1 plus MTS in diets. The results of this study indicated that the use of MTS independently reduced the toxic effects of AFB1, facilitated the absorption of nutrients, and reduced the metabolic demands of the intestinal tract in broiler chickens.

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