Beverly L. Giammara

Glycocalyx Enhances Prosthetic Vascular Graft Infection

Coagulase-negative staphylococci are major pathogens in prosthetic implant infections, and the capability of certain strains to produce glycocalyx enhances their infectivity. We investigated the importance of glycocalyx in an animal model of prosthetic vascular graft infection. Coagulasenegative staphylococci (5×10 8 ) and 1 cm 2 pieces of Dacron or polytetrafluoroethylene (PTFE) grafts were placed in subcutaneous pockets of adult Sprague-Dawley rats. Two strains of bacteria were used, one producing and the other not producing glycocalyx. At 5 days, uninfected grafts were incorporated into the surrounding tissues whereas infected grafts were surrounded by fluid. Grafts were excised and adherent bacteria dislodged by sonication and quantitated. Scanning electron microscopy confirmed the presence of bacteria and glycocalyx, and the efficiency of bacterial dislodgement by sonication. The bacterial adherence (CFU/cm 2 mean ± SE) of glycocalyx-producing staphylococci was 3.7±1.1×10 7 and 3.5±1.0×10 5 to Dacron and PTFE, respectively (both 4 ) and PTFE (0.9±0.4±10 4 ). Antibiotic administration reduced the adherence of the nonglycocalyx producing strain by one log to both materials (p

Significance of Improved Cytochemical Methods for Hemoprotein Enzymes in Diagnosis and Classification of Leukemia

Success in achieving remissions of acute myelogenous leukemia (AML) since the 1950s, and especially since the mid-1970s, has developed a need for greater attention on the part of physicians to improved methods for diagnosing and classifying the leukemias. The majority of AML patients can achieve first remissions, some (5–10%) lasting several years; these prolonged survivors are presumably cured of their leukemia. Many AML patients, however, are still not receiving the benefits of improved diagnostic methods and intensive therapeutic regimens. Of the latter group 80% are dead within a year of diagnosis [1].