Crystal structure of murine cyclophilin C complexed with immunosuppressive drug cyclosporin A

Cyclophilin is a cellular receptor for the immunosuppressive drug cyclosporin A (CsA). Cyclophilin C (CyPC) is highly expressed in murine kidney, making it a potential mediator of the nephrotoxic effects of CsA. The structure of murine CyPC complexed with CsA has been solved and refined to an R factor of 0.197 at a 1.64-A resolution. Superposition of the CyPC-CsA structure with the unligated cyclophilin A (CyPA) revealed significant migration of three loops: Gln-179 to Thr-189, Asp-47 to Lys-49, and Met-170 to Ile-176. The proximity of the loop Gln-179 to Thr-189 to the CsA binding site may account for the unique binding of a 77-kDa glycoprotein, CyPC binding protein (CyCAP), to CyPC. The binding of CsA to CyPC is similar to that of CsA to human T-cell cyclophilin A (CyPA). However, the conformation of CsA when bound to CyPC is significantly different from that when bound to CyPA. These differences may reflect conformational variation of CsA when bound to different proteins. Alternatively, the previous CyPA-CsA structure at low resolution may not provide sufficient details for a comparison with the CyPC-CsA structure.

Optical perfect-shuffle-exchange interconnection network using a liquid-crystal spatial light switch

The perfect-shuffle-exchange interconnection network (e.g., the omega network) is a type of free-space regular multistage interconnection network. An equivalent omega network that consists of left- and right-perfect-shuffle interconnects as well as spatial light switch devices is described. An optical omega network that uses two special polarization prisms and a liquid-crystal spatial light switch is presented. The experimental results of a 8 x 8 omega network are reported. The optical omega network has the features of simple architecture and ease of integration.

[Determination of trace chloride and sulfate in drugs by ion chromatography]

Chloride and sulfate in magnesium trisilicate, activated charcoal, vesnarinone and bendazac were determined by the IC conductimetric detection. Analysis were performed by using a separating column (100 x 6 mm i.d.) packed with anion exchanger and with a stripper column (100 x 6 mm i.d.); 1.4 mmol/L Na2CO3 and 1.4 mmol/L Na2CO3-0.75 mmol/L NaHCO3 were used as eluents respectively. The peak height was linear with concentration from 10(-6) to 10(-3) mol/L for Cl- and from 10(-5) to 10(-3) mol/L for SO4(2-). Results showed no significant difference as compared with those determined by the CHP (1985) and CHP (1990) appendices methods. The IC method is specific, sensitive, simple and rapid.

[The measurement of radial bone mineral content in children]

The bone mineral contents of radius of 255 boys and 243 girls (7 to 16 year old of the Han nationality, living in Chengdu) were measured with Bone Mineral Analyzer (Type:SPA-I). The standard values of g/cm was made. There was a positive correlation between the value in boys or girls and chronological age, height or weight. The coefficients were respectively 0.83, 0.77, 0.64 in boys and 0.82, 0.82, 0.82 in girls (P less than 0.005). At the age of 13 (in boys or in girls) the value of the g/cm was the highest.