PubMed Health⌕ Search

Biomedical subjects

John A Branda

Publications and source records attributed to John A Branda.

8 recordsLinked to original sources
PubMed2007

Sensitivity of peripheral blood smear review for the diagnosis of Candida fungemia.

CONTEXT: Case reports have described detection of candidemia by examination of peripheral blood smears. It is unclear whether this method has wider applicability for early detection of fungemia. OBJECTIVE: To determine the sensitivity of smear review for detecting candidemia. DESIGN: Normal and cytopenic blood was spiked with increasing concentrations of yeast. Smears were prepared and reviewed by a pathologist and by technical staff. Staff members blinded to the purpose of the study first performed a routine slide review and then a targeted review for yeast. RESULTS: The pathologist detected isolated yeast forms at a concentration of 1 to 5 x 10(5) colony-forming units (CFU)/mL. When blinded to the purpose of the study, technical staff could detect Candida in most samples when the yeast concentration was 1 to 5 x 10(7) CFU/mL, but found it in only a small fraction of samples with lower concentrations. When asked to examine the smears specifically for yeast, they could detect it in most samples containing 1 to 5 x 10(6) CFU/mL. CONCLUSIONS: Detection of candidemia by peripheral blood smear examination requires a yeast concentration of 1 to 5 x 10(5) CFU/mL or greater. This degree of fungemia is unusual; therefore, detection of candidemia by blood smear review will not be possible in most cases. Sensitivity of smear review for yeast detection is greatly increased if the microscopist is specifically directed to look for the presence of yeast.

Candida↗
PubMed2006

A rational approach to the stool ova and parasite examination.

BACKGROUND: Examination of multiple stool specimens per patient to rule out parasitic infection continues to be recommended in the literature. Attractive alternatives have been proposed, such as examination of a single specimen, but data to support their use have been inconclusive. METHODS: We reviewed the results of comprehensive stool ova and parasite examinations performed during a 1-year period to determine the incremental value of examining >1 specimen. Next, we implemented rejection criteria, allowing analysis of only a single specimen in most cases, and studied the impact of the change by reviewing data from a subsequent year. RESULTS: Prior to implementation of rejection criteria, 91% of parasites were detected in the first specimen submitted, although many clinical evaluations (72%) involved the submission of only 1 stool specimen. When at least 3 specimens were submitted, the sensitivity of examining the first in the series was 72%. Even the latter sensitivity provides negative predictive values of approximately 98%, approximately 97%, approximately 95%, or approximately 93% when the prevalence of parasites among those tested is 5%, 10%, 15%, or 20%, respectively. Examination of additional specimens after examination of the first specimen that yielded a positive finding revealed previously undetected parasites in only 10% of cases. After the application of rejection criteria, the parasite detection rate did not change significantly. CONCLUSIONS: Comprehensive examination of a single stool specimen is sufficient for most patients, when the prevalence of infection among the tested population is up to 20%. Rational use of the stool ova and parasite examination relies on communication between clinician and laboratory, and retention of deferred specimens in case examination of additional specimens is clinically warranted.

Animals↗
PubMed2006

Effects of yeast on automated cell counting.

We studied the effects of yeast in peripheral blood samples on results reported by an ADVIA 120/2120 Hematology System (Bayer HealthCare, Diagnostics Division, Tarrytown, NY). In a simulated candidemia model, very high concentrations (1-5 x 10(8) colony-forming units [CFU]/mL) of Candida glabrata and Candida parapsilosis caused a spuriously elevated platelet count. No such effect was observed with Candida albicans. All 3 yeast species, when present at a concentration of 1-5 x 10(6) CFU/mL or greater, increased the automated WBC counts significantly and in a dose-dependent manner. The yeast cells were mainly misidentified as lymphocytes. All spurious results were flagged by the cell counter for microscopic review. We conclude that although the presence of yeast in a blood sample can interfere with the ADVIA 120/2120 Hematology System, compromised results are appropriately flagged by the instrument and are seen only when the yeast concentration is very high.

Candida↗
PubMed2002

Bioterrorism. Clinical recognition and primary management.

The recent anthrax attacks in the United States have demonstrated the reality of bioterrorist threats as well as the need for preparedness and planning to mount a successful response to such events. Medical practitioners have a key role in responding to bioterrorist activity because they can contribute to the timely recognition of an event and to the mitigation of morbidity resulting from a bioterrorist attack. The medical community needs to become familiar with how to recognize and manage diseases produced by the biologic agents that might be used by terrorists. This review summarizes the microbiological and clinical aspects of the agents of anthrax, smallpox, plague, and tularemia, which are all considered likely bioterrorist weapons.

Anthrax↗