Biomedical subjects
T L Hadfield
Publications and source records attributed to T L Hadfield.
Mycoses caused by Candida lusitaniae.
Candida lusitaniae, a fungus with a low incidence of infection in immunocompetent people, is emerging as an opportunistic pathogen in immunocompromised hosts. This yeast is generally resistant to amphotericin B and may present therapeutic difficulties. C. lusitaniae may be misidentified as one of several other fungal species, including Candida tropicalis, Candida parapsilosis, and even Saccharomyces cerevisiae. As judged by in vitro antifungal susceptibility testing, minimal inhibitory concentrations of antifungal agents other than amphotericin B are achievable, but fungicidal levels are not. When encountered in blood or other body sites, C. lusitaniae should be carefully considered as a potential pathogen.
Cat scratch disease and acquired immunodeficiency disease: diagnosis by transmission electron microscopy.
A 33-year-old, homosexual, cat-owning, African-American man with human immunodeficiency virus infection by positive serologic tests and acquired immunodeficiency syndrome by CD4 lymphocyte count alone (39 cells/mL) presented with a one-year history of intermittent fever, weight loss, and generalized lymphadenopathy. A malignant lymphoma was suspected clinically. Light microscopic study of a left inguinal lymph node biopsy specimen revealed effacement of the lymph node architecture by a diffuse infiltrate of large, atypical reticulum cells, loose, patchy granulomatous inflammation, diffuse hyaline fibrosis, diffusely proliferated blood vessels, and multifocal degeneration and necrosis. Lymph follicles were absent and lymphocytes were moderately depleted. Microorganisms were not seen in lymph node sections stained with special histochemical stains (including the Warthin-Starry stain). These light microscopic changes were considered suggestive of a malignant lymphoma, especially Hodgkin's disease. The diagnosis of cat scratch disease (CSD) became apparent only after transmission electron microscopic study of the lymph node revealed clusters of small, pleomorphic bacteria in degenerated collagenous tissue and in blood vessel walls. This case illustrates the value of transmission electron microscopy in making the diagnosis of CSD, especially when light microscopic changes are superimposed on those of late human immunodeficiency virus infection of the lymph node.