It has been reported that macrophages primarily mediate endotoxin shock and cell death by synthesizing and releasing cytokines, largely tumor necrosis factor (TNF) and interleukin-1 (IL-1). However, macrophages from some laboratory mouse strains such as C3h/HeN are unresponsive to endotoxin both in vivo and in vitro. We found members of a wild rodent species, Sigmodon hispidus, to also be extremely resistant to bacterial endotoxin challenge. Intravenous administration of up to 100,000 micrograms/kg body mass of Escherichia coli O26:B6 endotoxin did not cause lethality in adult S. hispidus. In contrast to the endotoxin-resistant mouse strain, peritoneal macrophages derived from S. hispidus were responsive to in vitro endotoxin challenge as measured by high levels of TNF and IL-1 activity in supernatants of macrophage cultures. Thus, in vitro macrophage responsiveness to endotoxin does not always indicate high host sensitivity to endotoxin challenge.

Animals↗

PubMedDate not supplied

Hospital autopsies: still valuable in their traditional role but in need of reform.

In 1997, 158 autopsies were performed at Charleston Area Medical Center, a community-based, teaching tertiary care center. The autopsies revealed 29 (18.4%) clinically undiagnosed principal causes of death, of which 79% were considered treatable. The five leading undiagnosed causes were: infarctions, 27.6%; malignant neoplasms, 17.2%; pulmonary emboli, 13.8%; dissecting or ruptured aortic aneurysms, 13.8%; and genetic or congenital disorders 10.2%. These results were significantly different from those reported from some other major tertiary care centers. Reports were completed in 5-302 days (average 59, median 32 days). For more than 40 (25%) of these autopsies, the purpose was only to confirm specific disorders such as occupational injury, which can be accomplished by a highly selective, cost-effective posthumous analysis. In summary, an autopsy in today's high-technology era is still useful, however, the high cost, long length of reporting time, and number of clinically non-enlightening cases are a reasons to reform both the format and procedure in which these procedures are conducted.

Adolescent↗