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Dietary electrolyte balance (dEB) is known to affect acid-base status and mineral metabolism, but is rarely considered in diet formulation for pigs. Yet, the use of a wide variety of local feedstuffs in Europe contributes to lowering the dEB and increasing the fibre content. Hence, mineral requirements may be modified and skeletal health affected. Therefore, the effects of a lower dEB and a higher dietary Ca level on acid-base balance and mineral status were assessed in young pigs fed a diversified diet. A total of twenty-four weaned pigs were fed a control moderate-dEB diet (C) or a diversified moderate-dEB (D), low-dEB (D-A) or low-dEB supplemented with Ca (D-CA) diet. Growth performance, venous blood gas and chemistry, urine pH, mineral balance and femur characteristics were determined. With an equivalent dEB compared with the C diet, the D diet caused an acidification of the urine and increased the excretion of P as a result of a higher dietary content of S. Low-grade metabolic acidosis occurred in piglets fed the D-A diet with changes at systemic and urine levels. A higher excretion of ammonia and P in urine was observed and some bone characteristics tended to be negatively affected. Ca supplementation partially counteracted the effects of low-grade acidosis. Urine excretion of P and ammonia was alleviated and bone characteristics improved. In conclusion, a higher Ca supply must be considered in more diversified diets to counteract the risk of evolving towards low-grade metabolic acidosis which can negatively affect bone.

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Piglet neonatal diarrhoea is an important issue in modern pig production and is linked to increased mortality and poor growth rates, affecting long-term pig health, increasing use of medication and cost of production. Saccharomyces cerevisiae var. boulardii (SB) is a probiotic yeast with documented clinical efficacy in the prevention and treatment of diarrhoeal diseases in humans. The objectives of the current study were to evaluate the effect of SB on occurrence and severity of neonatal diarrhoea in piglets, mortality and growth rate. Forty-six litters (606 piglets) were randomly allocated to a control or SB treatment (n=23 per treatment). Within 24 h of farrowing, piglets assigned to the SB treatment received a single oral dose of a paste containing 3.3×10(9) CFU of SB CNCM I-107(9). Piglets from the control litters received a placebo paste. Piglet weight, mortality and diarrhoea were recorded up to day 7 of age. It was shown that numbers of diarrhoea days were significantly correlated with increased mortality rate and reduced weight gain (P<0.05). SB treatment had no effect on growth or mortality in diarrhoeic litters. However, SB-supplemented litters had significantly lower faecal scores, indicating firmer faeces (P<0.01) and fewer numbers of diarrhoeic days (P<0.01) during the 1(st) week of life. Reduction in the number of diarrhoeic litters compared with the control group was observed following the probiotic administration (P<0.05). These results highlight the detrimental effects of neonatal diarrhoea on pre-weaning performance and suggest that SB, by reducing diarrhoea duration and severity, has the potential of improving enteric health in the early stages of life in pigs.

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(1) The aim of the experiment was to re-examine variations in digestibilities of food components in 3-week-old broiler chickens fed on pelleted diets based on wheats differing in lipase activity and hardness. Fourteen wheat (Triticum aestivum) samples, each from a different cultivar, were included at 550 g/kg in 14 different diets given to male Ross broiler chicks from 7 d of age. The other main ingredients consisted of soyabean meal (353 g/kg) and rapeseed oil (55 g/kg). A 15th diet containing durum wheat (Triticum durum) was also tested. (2) Hardness of wheats (Triticum aestivum) varied between 14 (very soft) and 88 (very hard), and lipase activity of wheats varied from 1 to 13.1 (relative scale). No significant correlation was found between in vitro viscosities and other parameters such as hardness, particle size of wheat flours and lipase. Hardness was correlated with the mean particle size of wheat flours and durability of pellets. (3) Individual lipid digestibilities were negatively correlated with in vitro viscosities of wheats. (4) Individual starch digestibilities were negatively correlated with wheat hardness, particle size of wheat flour before pelleting, and pellet durability. The ratio of measured AME(N) to predicted AME(N) was also negatively correlated with wheat hardness. Simple regression calculation showed that a 100-point increase in wheat hardness resulted in a 3% decrease in the AME(N) value of diets. Multiple regression calculation showed the food/gain ratio (d 10 to d 21) to be positively related to wheat hardness and negatively related to pellet durability. (5) Wheat lipase activity was positively correlated with individual starch digestibility, which was the reverse of a result obtained in a previous experiment. Thus, wheat lipase activity did not seem consistent for predicting starch digestibility and AME(N) values. (6) Among all wheat samples, durum wheat showed the highest protein content and the lowest content of water-insoluble cell-wall. Starch digestibility of durum wheat tended to be lower than that of other wheats (0.916 vs 0.936). However, no significant difference in AME(N) was observed between the durum wheat sample and other wheats. (7) Gut morphometric data measured at d 24 did not show significant differences between dietary treatments.

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Lamivudine, an antiviral agent, has a potential role in the treatment of recurrent or acquired de novo hepatitis B virus (HBV) infection after liver transplantation. During lamivudine therapy, residual HBV particles in serum, PBMC, and liver were quantified in 7 patients in whom hepatitis B occurred de novo (n = 4) or recurred (n = 3). HBV DNA and preS1 antigen were measured using a sensitive PCR technique and an in-house ELISA method, respectively. The genetic and antigenic properties of HBV variants that emerged during lamivudine treatment were also examined. One month after the outset of lamivudine treatment, all 7 patients remained positive for both HBV DNA and preS1 antigen in serum, reflecting residual HBV replication. At the end of therapy, four patients were considered to be lamivudine responders, including one who seroconverted to anti-HBs but remained HBV DNA positive in the liver (> 10(3) copies/microg of DNA). Among the three patients who did not respond to lamivudine, one had pol mutations (L450P and S550C) that had not been described previously, in addition to the common mutations within the YMDD locus and B domain. Defective core and preS viral proteins and atypical sedimentation profiles of HBV DNA-positive particles were observed in all three lamivudine-resistant patients. These findings confirm the persistence of HBV in liver transplant recipients despite strong inhibition of replication by lamivudine, and show abnormal viral transcription and/or morphogenesis in lamivudine-resistant patients.

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Patients with chronic hepatitis C present an imbalance of Th1/Th2 cytokine production. Therefore, we investigated whether the exposure of the CD4+ T cell line H9 to HCV could induce activation of cells through synthesis of IL-10. Three infection protocols were performed to enhance HCV propagation. Viral particles were prepared by ultracentrifugation of serum from patients. From 3 to 81 days post-infection (p.i.), HCV-RNA was monitored both in supernatants and cells by nested RT-PCR, IL-10 protein in medium by ELISA, and IL-10 mRNA in cells by semi-quantitative RT-PCR. The expression of tetraspanins was analyzed by flow cytometry. The PKC signal pathway was studied using specific inhibitors. The H9 cells express CD81. HCV-RNA (+) was detected in cells until 21 days p.i, and in culture media over 39 days p.i. Up to day 81 p.i., HCV exposure induced a specific, 2-fold increase of IL-10 production by H9 cells. IL-10 production was inhibited by a PKC inhibitor (Calphostin C). This study shows that even if the infection of H9 T cells did not result in any viral progeny, HCV induced the activation of IL-10 secretion, which supports the role of IL-10 in HCV pathogenesis.

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Biofilm are formed wherever there is some water in our environment: pipes, pipelines, tap water systems, air conditioning systems... Furthermore, the ecological and economical consequences are very important: energy losses, bacterial contamination, material deterioration. The aim of this work is to develop a new method to detect and monitor the biofilm formation. This method can also determine some mechanical properties of the biofilm. An application of this method is a realization of a biofilm sensor. Biofilm is considered as an inert porous layer with respect to mass transport. In our experiment, the biofilm is grown on a gold electrode in natural seawater. Its thickness is determined by considering the oxygen diffusion limiting current measured for different rotation speeds on this electrode. Two different incubators are used during the biofilm development: one, with a laminar flow, permits the rotation of the electrode during the biofilm formation, and for the second, a tube is used under turbulent conditions during the biofilm formation. This experiment allows us to characterize the mechanical behavior (thickness, elasticity, rigidity) of the biofilm in function of different conditions of development.

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An in-house sensitive and easy-to-use solid-phase enzyme-linked immunoassay (ELISA) was adapted for the detection and quantification of hepatitis B virus (HBV) PreS1 envelope antigen in serum, and compared with the HBV DNA Hybrid Capturetrade mark system from Murex and the polymerase chain reaction (PCR) Amplicortrade mark HBV Monitor assay from Roche. Twenty-five patients with chronic hepatitis B after liver transplantation were included in this study. The sensitivity of our ELISA was found to be 50 pg of HBsAg/PreS1Ag ml-1. The linearity was between 0.1 and 100 ng ml-1. Intra-assay reproducibility was obtained with a standard deviation of <1%. No correlation between the presence of serum PreS1 antigen and viral DNA detected by direct hybridization (Murex) was observed. In contrast, there was a significant 96% correspondence in the presence of PreS1 antigen and viral DNA detected and quantified by the PCR assay (Roche). In conclusion, the most important and reliable markers for monitoring residual HBV replication in serum were HBV DNA by the PCR assay, and virus envelope PreS1Ag by our in-house ELISA. Thus, PreS1Ag disappearance in serum could be used for evaluating the efficacy of antiviral therapies.

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