Management of metabolic hydrogen ([H]) in the rumen has been identified as an important consideration when reducing ruminant CH4 emissions. However, little is known about hydrogen flux and microbial rumen population responses to CH4 inhibition when animals are fed with slowly degradable diets. The effects of the anti-methanogenic compound, chloroform, on rumen fermentation, microbial ecology, and H2/CH4 production were investigated in vivo.
View Article and Find Full Text PDFGingival atrophy manifests as exposure of the tooth root surface because of recession of the gingiva, a condition that affects >20% of adults and leads to increased root sensitivity and ultimately, tooth loss. Tissue engineering approaches that employ novel synthetic polymeric scaffolds are being considered for rebuilding the gingival lamina propria lost in the atrophic process. Specifically, polyurethane hydrogels (degradable/polar/hydrophobic/ionic polyurethane [D-PHI]) can enhance the proliferation of human gingival fibroblasts (HGFs) and collagen production in a perfusion system.
View Article and Find Full Text PDFMedium perfusion has been shown to enhance cell proliferation and matrix protein production. In more recent work, under perfusion, a degradable/polar/hydrophobic/ionic polyurethane (D-PHI) scaffold was shown to enhance growth and production of collagen by human gingival fibroblasts (HGFs). However, the nature of the HGFs cultured in the perfused D-PHI scaffolds, and the mechanisms by which medium perfusion activates these cells to facilitate proliferation and collagen production are not defined.
View Article and Find Full Text PDFMost natural tissues consist of multi-cellular systems made up of two or more cell types. However, some of these tissues may not regenerate themselves following tissue injury or disease without some form of intervention, such as from the use of tissue engineered constructs. Recent studies have increasingly used co-cultures in tissue engineering applications as these systems better model the natural tissues, both physically and biologically.
View Article and Find Full Text PDFSeveral unique Sus-like polysaccharide utilization loci (PULs) were identified from bacteria resident in bovine rumen microbiomes through functional screening of a fosmid library. The loci were phylogenetically assigned to the genus Prevotella within the phylum Bacteroidetes. These findings were augmented by a bioinformatic re-evaluation of ruminal Prevotella genomes, revealing additional loci not previously reported in the literature.
View Article and Find Full Text PDFPeriodontal diseases cause the breakdown of the tooth-supporting gingival tissue. In treatments aimed at gingival tissue regeneration, tissue engineering is preferred over the common treatments such as scaling. Perfused (dynamic) culture has been shown to increase cell growth in tissue-engineered scaffolds.
View Article and Find Full Text PDFMorphologically and biochemically diverse members of the Treponema genus are present in the gastrointestinal tract of ruminants, yet very little is understood about their functional importance to this microbiome. Here we describe the annotated draft genome sequence of Treponema sp. strain JC4, a novel spirochete isolated from a bovine rumen sample.
View Article and Find Full Text PDFThe fibronectin (Fn) binding conformation on mica and ultraflat poly(D,L-lactide-co-glycolide) (UPLGA) was characterized using atomic force microscopy (AFM). AFM topographic images showed that Fn was in an extended form on mica and in a compact structure on UPLGA. With immuno-AFM, an antibody (Ab(hep)) was used to characterize the Fn binding conformation.
View Article and Find Full Text PDFBackground: Leptin is a protein produced by adipose tissue that circulates to the brain and interacts with receptors in the hypothalamus to inhibit eating. In obese humans, serum leptin is up to four times higher than in lean subjects, indicating that human obesity is associated with a central resistance to the weight-lowering effects of leptin. Although the leptin-deficient mouse (ob/ob) develops obesity hypoventilation syndrome (OHS), in humans with OHS, serum leptin is a better predictor of awake hypercapnia in obesity than the body mass index (BMI).
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