Osteoarthritis of the talonavicular joint with pseudarthrosis of the navicular bone: a case report

Abstract Introduction Osteoarthritis of the talonavicular joint caused by inflammatory, degenerative, and post-traumatic arthritis has been commonly described, and isolated arthrodesis for talonavicular joint has usually been performed for such conditions. However, arthritis accompanied by pseudarthrosis of the navicular bone is an extremely rare case, and to the best of our knowledge, isolated arthrodesis for this situation has not been previously described in any published reports. Case presentation The patient was a 39-year-old Japanese man. He had complained of pain in his left middle foot since a fall from his motorcycle six months previously. Radiographs and computed tomography (CT) scans revealed pseudarthrosis of the navicular bone. MRI indicated mild arthritic change in the talonavicular joint and avascular necrosis of the navicular bone. We performed an isolated arthrodesis of the talonavicular joint with two 6.5 mm cancellous screws. One year after the operation, radiographical bone union had been obtained, and the patient reported no pain and complete satisfaction with the result. Conclusions Isolated talonavicular arthrodesis is one of the effective procedures for the treatment of traumatic talonavicular arthritis with pseudarthrosis of the navicular bone both in providing pain relief and functional improvement.</p

Convergent Synthesis of a Bisecting N-Acetylglucosamine (GlcNAc)-Containing N-Glycan

The chemical synthesis of a bisecting N-acetylglucosamine (GlcNAc)-containing N-glycan was achieved by a convergent synthetic route through [4+2] and [6+2] glycosylations. This synthetic route reduced the number of reaction steps, although the key glycosylations were challenging in terms of yields and selectivities owing to steric hindrance at the glycosylation site and a lack of neighboring group participation. The yields of these glycosylations were enhanced by stabilizing the oxocarbenium ion intermediate through ether coordination. Glycosyl donor protecting groups were explored in an effort to realize perfect α selectivity by manipulating remote participation. The simultaneous glycosylations of a tetrasaccharide with two disaccharides was investigated to efficiently construct a bisecting GlcNAc-containing N-glycan

The Core Fucose on an IgG Antibody is an Endogenous Ligand of Dectin-1

The core fucose, a major modification of N-glycans, is implicated in immune regulation, such as the attenuation of the antibody-dependent cell-mediated cytotoxicity of antibody drugs and the inhibition of anti-tumor responses via the promotion of PD-1 expression on T cells. Although the core fucose regulates many biological processes, no core fucose recognition molecule has been identified in mammals. Herein, we report that Dectin-1, a known anti-β-glucan lectin, recognizes the core fucose on IgG antibodies. A combination of biophysical experiments further suggested that Dectin-1 recognizes aromatic amino acids adjacent to the N-terminal asparagine at the glycosylation site as well as the core fucose. Thus, Dectin-1 appears to be the first lectin-like molecule involved in the heterovalent and specific recognition of characteristic N-glycans on antibodies

The core fucose on an IgG antibody is an endogenous ligand of Dectin-1

The core fucose, a major modification of  N -glycans, is implicated in immune regulation, such as the attenuation of the antibody-dependent cell-mediated cytotoxicity of antibody drugs and the inhibition of anti-tumor responses via promotion of PD-1 expression on T cells. Although the core fucose regulates many biological processes, no core fucose recognition molecule has been identified in mammals. In the present study, we discovered that Dectin-1, a known anti- b -glucan lectin, recognizes the core fucose on IgGs. A combination of biophysical experiments further suggested that Dectin-1 recognizes aromatic amino acids adjacent to the  N -terminal asparagine residue at the glycosylation site as well as core fucose residue. Thus, Dectin-1 appears to be the first lectin-like molecule involved in the hetero-valent and specific recognition of characteristic  N -glycans on antibodies