Chondroblastoma in a metatarsal treated with autogenous fibular graft: a case report

Chondroblastoma is a relatively rare tumor that mimics giant cell tumor and displays a predilection for long bones. In the present report, we describe the case of a benign chondroblastoma localized to the second metatarsal in a 20-year-old male who presented with a 2-year history of painless left foot swelling. Treatment of the tumor involved excision of the second metatarsal with use of an autologous structural fibular bone graft to stabilize the metatarsus and second toe. After 27 months of follow-up, the patient was ambulating well in regular shoes, with no clinical or radiographic evidence of tumor recurrence.     

Bilateral inferior dislocation of the hip---a case report

Inferior dislocation of the hip is the rarest type in hip dislocation.Very few cases have been reported in the anglophonic literature,most of which involved the pediatric age group.Surprisingly,we came...     

Crystal structures of human adenosine kinase inhibitor complexes reveal two distinct binding modes

Adenosine kinase (AK) is an enzyme responsible for converting endogenous adenosine (ADO) to adenosine monophosphate (AMP) in an adenosine triphosphate- (ATP-) dependent manner. The structure of AK consists of two domains, the first a large alpha/beta Rossmann-like nucleotide binding domain that forms the ATP binding site, and a smaller mixed alpha/beta domain, which, in combination with the larger domain, forms the ADO binding site and the site of phosphoryl transfer. AK inhibitors have been under investigation as antinociceptive, antiinflammatory, and anticonvulsant as well as antiinfective agents. In this work, we report the structures of AK in complex with two classes of inhibitors: the first, ADO-like, and the second, a novel alkynylpyrimidine series. The two classes of structures, which contain structurally similar substituents, reveal distinct binding modes in which the AK structure accommodates the inhibitor classes by a 30 degrees rotation of the small domain relative to the large domain. This change in binding mode stabilizes an open and a closed intermediate structural state and provide structural insight into the transition required for catalysis. This results in a significant rearrangement of both the protein active site and the orientation of the alkynylpyrimidine ligand when compared to the observed orientation of nucleosidic inhibitors or substrates.