James C. Guckian

Pneumocystis carinii Pneumonia Treated with Pyrimethamine and Sulfadiazine

Abstract Pentamidine isethionate has been considered the only effective agent in the treatment ofPneumocystis cariniipneumonia. Its toxicity makes it less than the ideal drug. Pyrimethamine and sul...

Granulomatous hepatitis of unknown etiology: An etiologic and functional evaluation

Abstract The diagnosis in patients with granulomatous hepatitis can usually be obtained if the proper approach and criteria, such as previously outlined, are utilized. Liver destruction and fibrosis can usually be halted if specific therapy for infectious causes is instituted. Corticosteroid therapy seems to be indicated in patients with sarcoidosis with documented severe or progressive hepatitis, that is, the presence of jaundice, hypoalbuminemia, ascites, markedly elevated alkaline phosphatase levels and portal hypertension. Granulomatous disease may be associated with agammaglobulinemia, autoimmune disease, hematopoietic malignancies and carcinomas. Whether there is a statistically significant correlation between these diseases is not known.

Complement-independent Adherence of Escherichia coli to Complement Receptors In Vitro

We studied adherence to human cells by a strain of Escherichia coli. Adherence to erythrocytes was assessed directly by phase-contrast microscopy and indirectly by hemagglutination; adherence to peripheral blood leukocytes, using radiolabeled bacteria and subsequent determination of leukocyte-associated radioactivity; and adherence to renal glomeruli, by microscopy of fluoresceinated bacteria and of Gram-stained nonfluoresceinated bacteria. In serum-free systems, E. coli of this strain adhered to human erythrocytes, which have surface receptors for the third component of complement (C3), but not to erythrocytes from species lacking this receptor. 1 mM trypan blue, a reagent that inhibits complement receptor function, inhibited adherence to human erythrocytes, as well as adherence to leukocytes and glomeruli. Preincubation of erythrocytes and leukocytes with complement-coated zymosan particles partially blocked subsequent bacterial adherence. Incubation of human erythrocytes with aging human serum, with trypsin-cleaved C3, or with C3 cleaved by the classical pathway convertase (EAC142)-all of which treatments deposited C3 on the erythrocyte surface, presumably at C3 receptors-inhibited subsequent E. coli adherence. Finally, incubation of E. coli with rabbit antiserum to human C3 blocked adherence to erythrocytes.Bacterial hemagglutination and erythrocyte adherence were not inhibited by mannose in concentrations up to 2.5%. And this strain of E. coli did not adhere to or agglutinate guinea pig erythrocytes, the usual test particle used for demonstration of common pili. Finally, electron microscopy of adherent bacteria showed only rare surface pili. In contrast, adherence to and agglutination of guinea pig erythrocytes by a stock piliated E. coli was inhibited by mannose but not by trypan blue. We conclude that organisms of this strain of E. coli adhere to human erythrocytes, leukocytes, and glomeruli at complement receptors. Complement is not required for this interaction. Adherence apparently involves a C3-like structure on the bacterial surface, but bacterial surface pili play no role. The physiological or pathological role of this adherence is not apparent, but study of this phenomenon may elucidate functions of complement receptors on various cells.