Knee meniscus tears are one of the most common musculoskeletal injuries. While meniscus replacements using allografts or biomaterial-based scaffolds are available, these treatments rarely result in integrated, functional tissue. Understanding mechanotransducive signaling cues that promote a meniscal cell regenerative phenotype is critical to developing therapies that promote tissue regeneration rather than fibrosis after injury.
View Article and Find Full Text PDFResin-based composite materials have been widely used in restorative dental materials due to their aesthetic, mechanical, and physical properties. However, they still encounter clinical shortcomings mainly due to recurrent decay that develops at the composite-tooth interface. The low-viscosity adhesive that bonds the composite to the tooth is intended to seal this interface, but the adhesive seal is inherently defective and readily damaged by acids, enzymes, and oral fluids.
View Article and Find Full Text PDFMeniscal injuries represent one of the most common orthopedic injuries. The most frequent treatment is partial resection of the meniscus, or meniscectomy, which can affect joint mechanics and health. For this reason, the field has shifted gradually towards suture repair, with the intent of preservation of the tissue.
View Article and Find Full Text PDFResidues glutamate 156 (E156), aspartate 190 (D190), asparagine 181 (N181), lysine 186 (K186), and asparagine 191 (N191) in the active site of S-adenosylhomocysteine (AdoHcy) hydrolase have been mutated to alanine (A). AdoHcy hydrolase achieves catalysis of AdoHcy hydrolysis to adenosine (Ado) and homocysteine (Hcy) by means of a redox partial reaction (3'-oxidation of AdoHcy at the beginning and 3'-reduction of Ado at the end of the catalytic cycle) spanning an elimination/addition partial reaction (elimination of Hcy from the oxidized substrate and addition of water to generate the oxidized product), with the enzyme in an open NAD(+) form in the ligand-free state and in a closed NADH form during the elimination/addition partial reaction. Mutation K186A reduces the rate of a model enzymatic reaction for the redox partial reaction by a factor of 280000 and the rate of a model reaction for the elimination/addition partial reaction by a factor of 24000, consistent with a primary catalytic role in both partial reactions as a proton donor/acceptor at the 3'-OH/3'-keto center.
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