Robert Tcholakian

Synthesis of new steroid haptens for radioimmunoassay—part V. 19-O-carboxymethyl ether derivative of testosterone. A highly specific antiserum for immunoassay of testosterone from both male and female plasma without chromatography

Abstract Synthesis of the 19- O -carboxymethyl ether derivative of testosterone and the preparation of its bovine serum albumin (BSA) conjugate is described. By employing this conjugate, antiserum was raised in rabbits which proved to be specific for testosterone. A radioimmunoassay (RIA) procedure is described for measurement of testosterone from both male and female plasma after ether-chloroform (4:1) extraction of the sample without prior chromatography.

Durability of Anti-Infective Effect of Long-Term Silicone Sheath Catheters Impregnated with Antimicrobial Agents

ABSTRACT This study was performed to test the long-term antimicrobial efficacy of impregnated silicone catheters comprising an antimicrobial layer sandwiched between an external surface sheath and a luminal surface silicone sheath. The design of the catheter permits the introduction of various antimicrobials in addition to anticoagulants or antifibrins in the antimicrobial layer and allows their gradual release over a period of months after insertion. The in vitro data presented show that the catheter can provide antimicrobial activity for 90 days, after being replated for 15 7-day cycles of replating. When the catheters were immersed in human serum and incubated at 37°C, they demonstrated significant antimicrobial activity after more than 325 days of incubation. The significant long-term in vitro antimicrobial activity observed may imply effective in vivo activity for almost 1 year after insertion and could serve as a cost-effective alternative to surgically implantable silicone catheters.