The evaluation of argon laser photocoagulation in a series of animal models of upper gastrointestinal bleeding

During the past five years we have evaluated argon laser photocoagulation in various canine models of upper gastrointestinal hemorrhage. In gastric erosions, the eight-watt argon laser was uniformly effective in stopping bleeding. In our standard acute ulcer model the seven-watt argon laser was effective in stopping bleeding from most ulcers and only occasionally produced deep injury. With the addition of a jet of CO2 exiting the laser catheter coaxial to the laser beam, the argon laser was 100% effective and no deep injury resulted. The application of the argon laser in a more physiologic canine bleeding model using a single bleeding vessel in an ulcer base is currently under study. The development of improved animal models of gastrointestinal bleeding should contribute to the identification of effective and safe endoscopic hemostatic methods.     

An unusual case of large right atrial myxoma

A case of right atrial myxoma is described. The patient had vague and variable symptoms and it was not until five years after first presentation that she had developed clinical and electrocardiographic evidence of right atrial hypertrophy, and angiocardiographic evidence of a fist-sized myxoma which was subsequently removed surgically.     

Stabilized variant of Streptomyces subtilisin inhibitor and its use in stabilizing subtilisin BPN'

Protein protease inhibitors could potentially be used to stabilize proteases in commercial products such as liquid laundry detergents. However, many protein protease inhibitors are susceptible to hydrolysis inflicted by the protease. We have engineered Streptomyces subtilisin inhibitor (SSI) to resist proteolysis by adding an interchain disulfide bond and removing a subtilisin cleavage site at leucine 63. When these stabilizing changes were combined with changes to optimize the affinity for subtilisin, the resulting inhibitor provided complete protease stability for at least 5 months at 31 degrees C in a subtilisin-containing liquid laundry detergent and allowed full recovery of the subtilisin activity upon the dilution that occurs in a North American washing machine.