ABSTRACT. Antimicrobial resistant Salmonella are becoming more prevalent. Therefore, alternative methods to control swine Salmonella infection must be explored. We examined whether feeding lactic acid to swine is an effective way to control clinical and subclinical Salmonella Typhimurium infection in these animals. In this experiment, swine were inoculated with 5.6  10 7 CFU (hi-ST) or 5.6  10 5 CFU (lo-ST) of S. Typhimurium per swine to reproduce clinical and subclinical infection. The swine were either fed a commercial feed supplemented with 2.8% lactic acid (LA) or the commercial feed without supplementation (C) to examine the effect of feeding lactic acid. Twenty 21 and 22 days old swine were divided into 4 groups, LA-hiST, C-hiST, LA-loST and C-loST, and fed the respective feed. They were inoculated S. Typhimurium at 51 and 52 days old. Clinical symptoms and the number of S. Typhimurium shed in feces were evaluated. The LA-hiST group did not show obvious clinical symptoms, such as diarrhea or febrile response, but the C-hiST group did show clinical symptoms. The number of S. Typhimurium shed in the feces of the LA-hiST group was lower than in that of the ChiST group, and that of the LA-loST group was lower than that of the C-loST group. Our data suggest that dietary supplementation with 2.8% lactic acid can be an effective way to control clinical and subclinical infections of S. Typhimurium in swine.

The purpose of this study was to evaluate the influence of flexural modulus of non-metal posts on the fracture strength and failure mode of composite resin cores. Thirty-two human premolars were divided into four groups: prefabricated glass fiber post with 1.0 mm diameter and composite resin core (Group PE1.0), that with 1.5 mm diameter and composite resin core (Group PE1.5), experimental post (flexural modulus; 4.25GPa) and composite resin core (Group EX), and preparation for abutment teeth only (Group NT). After a static loading test, the fracture strength and failure mode were recorded. Group NT (1670.81 N) showed higher fracture strength than Groups PE1.0 (866.44 N), PE1.5 (825.19 N) and EX (1075.63 N) (p<0.05). This study showed that the fracture strength of endodontically treated teeth restored with composite resin cores is not influenced by the flexural modulus of non-metal posts.

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The establishment of drug-free feeding systems has been required for secure and healthy livestock production. Although functional feed materials containing microorganisms as alternatives to enhance intestinal immunity are expected to be beneficial for reducing diarrhoea caused by pathogens in weaned piglets, the effects of such materials on porcine intestinal cells have not been investigated in detail. Therefore, this work evaluated the immunoregulatory functions of microbial feed materials in porcine intestinal immune and epithelial cells. Porcine immune cells isolated from Peyer's patches and mesenteric lymph nodes were stimulated with six different feed materials containing microorganisms, and evaluated for lymphocyte mitogenicity and cytokine inductions. In addition, porcine intestinal epithelial cells were stimulated with the materials before treatment with heat-killed enterotoxigenic Escherichia coli (ETEC), and analyzed for the proinflammatory cytokine expressions. The material containing Bifidobacterium thermophilum significantly augmented lymphocytes' mitogenicity and also induced a high expression of IL-2, IL-6 and IFN-γ in immune cells, and inhibited ETEC-induced overexpression of IL-6 and IL-8 via regulation * Theses authors have equal contribution. # Corresponding author. N. Kumagae et al. 16 of Toll-like receptor signaling. These results suggest that this feed material stimulates intestinal epithelial and immune cells to exert immunoregulation, suggesting that this feed is expected to contribute to promoting the health of piglets without using antimicrobial feed materials.