Showing papers on "Animal mortality published in 1998"

Efficacy of a Dry Fibrin Sealant Dressing for Hemorrhage Control After Ballistic Injury

Abstract: Objective To determine if a dry fibrin sealant dressing (DFSD) will provide superior hemostasis when compared with regular gauze in a ballistic injury animal model. Design A nonsurvival randomized goat study. Setting A federal biomedical research institute. Subjects Eighteen anesthetized Angora goats. Interventions Uncontrolled hemorrhage was induced by a complex ballistic extremity injury. Control of hemorrhage was achieved by applying and holding pressure with the DFSD or regular gauze for 2 minutes. The dressings were left in place for 1 hour. Main Outcome Measures Total blood loss, mean arterial pressure, ballistic injury, and mortality were recorded after 1 hour. Results The injuries were equivalent for the 2 groups. No animal mortality was seen. After 1 hour, the mean(±SEM) blood loss was 124±64 mL in the DFSD-treated group and 377±64 mL in the gauze dressings–treated group ( P =.01). Twenty minutes after injury, the mean arterial pressure was 95.0 mm Hg (±SEM, ±4.7 mm Hg) in the DFSD-treated group and 70.0±5.0 mm Hg in the gauze dressings–treated group. The difference persisted for the remainder of the study ( P =.01). Conclusion The DFSD was superior to gauze in decreasing blood loss and maintaining blood pressure while retaining the simplicity of standard dressing application.

A protective role for IL-6 during early infection with Toxoplasma gondii

Abstract: IL-6 deficient mice were found to be significantly more susceptible to peroral infection with Toxoplasma gondii than their wild-type counterparts as measured by survival, brain cyst burdens and brain pathology at 28 days post infection. The physical manifestations of disease, such as weight loss, were not observed in IL-6 deficient animals until at least seven days later than such changes occurred in wildtype mice. During this early stage of infection IL-6+/+ but not IL-6-/- mice mounted a peripheral blood neutrophilia. Furthermore, between 6-8 days post-infection there was a significant increase in plasma IFN-gamma levels in wild-type but not IL-6 deficient mice. Not until days 18-23 post-infection, concurrent with the majority of deaths in IL-6-/- mice, were plasma IFN-gamma levels substantially and significantly raised in IL-6-/- mice. At this time not only were these plasma IFN-gamma levels 20-fold higher than background but eight-fold greater than peak (6-8 days post-infection) IFN-gamma levels in IL-6+/+ mice. IFN-gamma dependent parasite specific IgG2a levels were also significantly higher in IL-6-/- mice over this period and thereafter. Overall the evidence suggests that in the absence of IL-6 mice are unable to initiate a rapid proinflammatory response against T. gondii, which allows increased parasite growth. Increased mortality in IL-6-/- mice may be directly due to this increased parasite burden and the excessive inflammatory response this induces three weeks post-infection.

Paleoethological Reconstruction and Taphonomy of Equus lambei from the Bluefish Caves, Yukon Territory, Canada

Abstract: The Bluefish Caves, northern Yukon, Canada, have yielded evidence of pre-Holocene human occupation of eastern Beringia. The three caves at Bluefish contain a large and complex late Pleistocene fauna in situ. Our research on the mortality patterns and the paleoethology of Equus lambei (an extinct species of horse), a dominant component of the Bluefish assemblages, was based on the dental remains. Mortality profiles for Equus lambei indicate that predators were the likely primary agents of bone accumulation at Cave I, while Caves II and III appear to have accumulated bones through accidental or natural deaths, probably regularly monitored by humans and other predator/scavengers. Paleoethological reconstruction for E. lambei , supports the suggestion the Bluefish Basin was not a polar desert during the late Pleistocene. Finally, the use of tooth height/age tables to establish age profiles of fossil equid populations is demonstrated to be limited to establishing broad, relative age categories.