Acetic acid-zinc-formalin: a safe alternative to B-5 fixative.

B5 fixation achieves superior morphologic detail. However, environmental concerns have led to labor-intensive and costly requirements for disposal of mercury-containing fixatives. We performed a blinded prospective study to find a safe, mercury-free alternative to B5. Morphology was evaluated with 6 fixatives, including B5, in a blinded fashion. Acetic acid-zinc-formalin (AZF) was selected for further evaluation of immunohistochemistry, in situ hybridization, and molecular analysis. AZF fixation resulted in overall staining and morphologic detail comparable to B5 and achieved equivalent or superior antigen preservation for immunohistochemical studies. Strong signal intensity was achieved with in situ hybridization, and DNA amplification could be successfully performed. AZF allows greater flexibility in fixation times, decreases decalcification time, and eliminates labor-intensive steps required for B5 processing.

Infectious diseases detected at autopsy at an urban public hospital, 1996-2001.

Previous studies have demonstrated significant discrepancy rates between clinical and autopsy diagnoses. However, infectious diseases have not received emphasis in these studies. We conducted a study to determine whether the clinical and autopsy diagnoses of infectious diseases are concordant or discrepant and to determine discrepancy rates. Retrospective reviews of the records of 276 patients (adults, 182; fetuses and neonates, 94) who underwent autopsy during the years 1996 through 2001 were performed. Comparison of clinical and autopsy diagnoses was performed using the Goldman classification scheme. Of 182 adult patients, 137 (75.3%) had an infectious disease at autopsy. In 59 (43.1%) of 137 patients, the infectious disease diagnoses were unknown clinically. Of 94 fetuses and neonates, 45 (48%) had an infectious disease at autopsy. In 26 (58%) of 45 patients, the infectious disease diagnoses were unknown before death. There are substantial discrepancies between clinical and autopsy diagnoses of infectious diseases. In adults, acute bronchopneumonia is the infectious disease most often missed clinically; in fetuses and neonates, it is acute chorioamnionitis.