Cigarette and nargileh smoking practices among school students in Beirut, Lebanon.

OBJECTIVES: To determine the prevalence and predictors of smoking nargileh and/or cigarettes among school students in Greater Beirut, Lebanon. METHODS: A proportionate random sample of 2443 students from 13 public and private schools was selected and asked to complete self-administered anonymous questionnaires. RESULTS: The prevalence of smoking cigarettes only, nargileh only, and both was 2.5%, 25.6%, and 6.3%, respectively. Stepwise regression analyses revealed that the predictors of smoking for either type are different, whereby nargileh smoking is more culturally accepted than cigarette smoking. CONCLUSIONS: Design interventions to increase awareness towards the hazards of the misconceived harmless effects of nargileh smoking.

Induction of local protective immunity to Eimeria acervulina by a Lactobacillus-based probiotic.

Previously we have shown that resistance to Eimeria acervulina (EA) infection in broiler chickens was enhanced by a probiotic treatment. In the present studies, we examined cytokine and oocyst production under similar conditions using a commercial Lactobacillus-based probiotic. Day-old male broiler chicks were fed control or probiotic diets and were orally challenged with either 2x10(4) (Experiment 1) or 1x10(4) (Experiment 2) oocysts of EA at 3 weeks of age. For the first experiment, fecal oocyst shedding and IFN-gamma levels in the culture supernatants of ConA-stimulated spleen lymphocytes were evaluated. Humoral and local cell-mediated immunity in the second experiment were assessed by evaluating antibody and cytokine (IFN-gamma and IL-2) levels in sera and intestinal secretions on a 3-day interval post inoculation. Results showed small but significant (P<0.05) differences in cytokine levels and oocyst production but not antibody levels between the probiotic-treated and control groups. Collectively, these data suggest a positive impact of the probiotic on cellular immune responses of infected broilers as compared to control chickens resulting in enhanced resistance to EA as shown in reduced fecal oocyst shedding. The results showed an immunoregulatory effect of probiotic diets on the local cell-mediated immunity in poultry and provide a rationale for further study to investigate the beneficial effects of Lactobacillus-based probiotics in food animals.

Influence of phytase on water-soluble phosphorus in poultry and swine manure.

The effect of dietary non-phytin phosphorus (NPP) and phytase (PHY) concentration on total phosphorus (TP) and water-soluble phosphorus (WSP) excretion was determined. Diets tested in broiler experiments were: National Research Council nutrient requirements for non-phytin phosphorus (NRC), NRC + PHY, reduced non-phytin phosphorus (RED), and RED + PHY. Turkey and swine experiment diets included NRC, RED, and RED + PHY. For all experiments, except broiler Experiment 1, excreta were: (i) boiled, antibiotic added, then frozen; (ii) boiled, antibiotic added, incubated (37 degrees C for 72 h), then frozen; and (iii) incubated, boiled, antibiotic added, then frozen. In Experiment 1, excreta were collected and frozen or incubated for 24 or 48 h. In broiler Experiment 1, WSP was not affected by phytase but increased with post-excretion incubation. In a broiler Experiment 2, reducing NPP resulted in reduced excreta TP and WSP (11.3 to 8.3 and 5.3 to 2.7 g kg(-1)). Feeding RED + PHY diets resulted in less TP and WSP (7.6 and 0.6 g kg(-1)) as compared with NRC + PHY (11.2 and 3.9 g kg(-1), Experiment 3). Incubation resulted in increased WSP, irrespective of phytase addition such that WSP as a percent of TP was similar among treatments. Addition of antibiotics before incubation prevented the increase in WSP. Similar results were observed with turkey and swine. Therefore, when phytase is used properly (i.e., with a simultaneous reduction of NPP), WSP or WSP as a percent of TP are not affected. The increase in WSP as a percent of TP post-excretion is a function of excreta microbial activity and not dietary phytase addition.

Phytate phosphorus hydrolysis as influenced by dietary calcium and micro-mineral source in broiler diets.

Phytate phosphorus (PP) hydrolysis by a 3-phytase was studied in vitro at pH 2.5 and 6.5 with either 0, 1.0, 4.0, or 9.0 g of Ca/kg diet, or 0, 1.0, 5.0, 7.5, or 10.0 g/kg diet of micro-mineral premix added as inorganic (IMM) or an equivalent level as micro-mineral-amino acid complexes (MAAC). Adding Ca or micro-minerals reduced (P < 0.05) PP hydrolysis at both pHs; however, the effect was greater at pH 6.5. An in vivo experiment was conducted in which broilers were fed one of six diets for 30 h. The experimental design was a factorial of three micro-mineral forms (0 added, IMM, and MAAC) and two Ca levels (0 or 5 g/kg). Adding Ca reduced (P < 0.05) PP disappearance and increased Ca apparent absorption. No micro-minerals effect (P > 0.05) was seen. Therefore, in poultry diets, it is Ca that inhibits PP hydrolysis and decreases P availability.

High-performance liquid chromatographic determination of biogenic amines in poultry carcasses.

Biogenic amines, produced by bacterial decarboxylation of amino acids, have been associated with toxicological symptoms in broilers fed various poultry byproducts. A reversed-phase high-performance liquid chromatographic method is described for the quantitation of eight biogenic amines (tryptamine, phenylethylamine, putrescine, cadaverine, histamine, tyramine, spermidine, and spermine) in chicken carcasses. Amines were extracted with perchloric acid, derivatized with dansyl chloride, separated using gradient elution (methanol and water), and detected by fluorescence. Benzylamine was used as the internal standard. Linearity, repeatability, and recovery of the method were evaluated. The method was linear for all of the amines studied at concentrations ranging from 0.05 to 25 microg/mL. Average recoveries ranged from 92.6% to 96.8% for all amines except for histamine, which was 74.6%.