Medicine
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Comparative Study
Molecular diagnosis of infective endocarditis by real-time broad-range polymerase chain reaction (PCR) and sequencing directly from heart valve tissue.
Traditionally, infective endocarditis (IE) has been microbiologically diagnosed by blood cultures or serology. However, conventional microbiologic methods do not always provide an etiologic diagnosis. We conducted the current study to evaluate the usefulness of a universal real-time polymerase chain reaction (PCR) of the 16S rRNA gene followed by sequencing for the diagnosis of IE in explanted heart valve tissue (HV) as part of the routine of a clinical microbiology laboratory, and to compare it with conventional culture of blood or HV. ⋯ Our universal PCR method has proved to be more sensitive, specific, and rapid than conventional culture methods, and should therefore be included as a new major Duke criterion for the diagnosis of IE. According to the results of the current study, this technique should be used to supplement blood and HV culture. Conventional HV cultures are frequently responsible for false-positive and false-negative results, and are not always useful to establish the etiology of IE.
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Chronic pulmonary histoplasmosis is a disorder caused by Histoplasma capsulatum infection that is classically described as cavitary disease in male smokers with underlying chronic obstructive pulmonary disease (COPD). This clinical description relies on previous studies conducted mainly on cohorts from tuberculosis sanatoriums and United States Department of Veterans Affairs hospitals. Patients in earlier series were often selected either after being suspected of having Mycobacteria tuberculosis or by the presence of cavitary disease on chest radiograph. ⋯ Female patients had a lower presence of cavities, a decreased number of smokers and extent of smoking exposure, a decreased number of positive cultures, and an absence of underlying COPD. To our knowledge, this study is the first to report on a large number of outpatients with chronic pulmonary histoplasmosis. In contrast to previous studies, the current study included 48% female patients, 27% never smokers, and only 39% of patients with cavitary disease, representing a noticeably different spectrum of disease compared to previous studies.
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Review Case Reports
Type B lactic acidosis as a severe metabolic complication in lymphoma and leukemia: a case series from a single institution and literature review.
Type B lactic acidosis is a rare complication of hematologic malignancies. The exact mechanism of this process is not well understood. Because caregivers may not be aware of the association of type B lactic acidosis with hematologic malignancies, it may go unrecognized as a cause of acidosis in these patients. ⋯ We also review 14 additional cases, most reported since 2001. From our review of the literature, we suggest that a deficiency of thiamine or riboflavin may play a more pivotal role than previously recognized in the development of type B lactic acidosis associated with malignancy. Further investigation should be undertaken to learn if thiamine or riboflavin replacement might be useful in treating this disorder.