Hypothermia differentially increases extracellular signal-regulated kinase and stress-activated protein kinase/c-Jun terminal kinase activation in the hippocampus during reperfusion after asphyxial cardiac arrest.

Mitogen-activated protein kinases are signal transduction mediators that have been implicated in cell survival and cell death. This study characterized the activation of pathways in the hippocampus during reperfusion after global cerebral ischemia, as well as the influence of a regimen of hypothermia that reduces ischemic cell death in the hippocampus. Circulatory arrest was induced in rats by 8 min of asphyxia. Relative levels of phosphorylated and total extracellular signal-regulated kinase, stress-activated protein kinase/c-Jun N-terminal kinase and p38 mitogen-activated protein kinase were measured in the hippocampus after 6, 12 or 24h of reperfusion using immunoblotting. Asphyxia induced a progressive increase in phosphorylated extracellular signal-regulated kinase and stress-activated protein kinase/c-Jun N-terminal kinase, but no change in phosphorylated p38 mitogen-activated protein kinase. Induction of mild hypothermia (33 degrees C) during reperfusion increased extracellular signal-regulated kinase phosphorylation and produced a smaller increase in stress-activated protein kinase/c-Jun N-terminal kinase phosphorylation at 24h. Hypothermia did not alter extracellular signal-regulated kinase activation in rats not subjected to ischemia. Extracellular signal-regulated kinase activation was associated with an increase in phosphorylation of the mitogen-activated protein kinase kinase 1/2, and was inhibited by administration of the specific mitogen-activated protein kinase kinase 1/2 inhibitor SL327. Immunohistochemical staining showed an increase in active extracellular signal-regulated kinase in the CA1, CA2, CA3 and dentate gyrus regions of the hippocampus after ischemia and reperfusion. In contrast, active stress-activated protein kinase/c-Jun N-terminal kinase immunoreactivity was most intense in the CA3 and dentate gyrus regions. These data demonstrate that both extracellular signal-regulated kinase and stress-activated protein kinase/c-Jun N-terminal kinase pathways are activated during the first 24h of reperfusion after global cerebral ischemia, and that hypothermia increases the activation of extracellular signal-regulated kinase relative to stress-activated protein kinase/c-Jun N-terminal kinase. Thus, an increase in extracellular signal-regulated kinase activation may be associated with improved neuronal survival after ischemic injury.

Utilization of the 911 system as an identifier of domestic violence.

This cross-sectional study was performed to determine (1) whether female victims of domestic violence (DV) are more likely to use the 911 system than nonvictims (NVs) and (2) whether DV and NVs call 911 for different reasons so that 911 may be used as a screening tool for abuse. The study was performed in an academic adult urban emergency department (ED). Ambulatory female patients presenting to the ED were studied. Eligible patients were administered a brief survey by trained research assistants. Questions included (1) history of DV, (2) relationship of assailant to victim, (3) chief complaint, and (4) use of the 911 system. Records of 911 calls were obtained by patient's address. Four hundred sixty-one women were enrolled in the study. One hundred seven (23%) reported a history of DV. Intimate partners accounted for 67.2% of assailants. DV victims were more likely to be single and younger (P < .05). Of DV victims, 77% reported calling 911 for any reason in the past 2 years compared with 47% of nonvictims (difference = 30%; 95% CI, 19%, 40%). DV victims were more likely to call 911 than nonvictims for definite and possible cases of domestic dispute (1.4 v0.5 calls, P = .007; 11.7 v6.1 calls, P = .0003). Victims and nonvictims did not differ in the number of nondomestic dispute calls (8.4 v6.2 calls; P = .15). DV victims were more likely to access the 911 system and call for domestic disturbances compared with nonvictims. 911 calls may serve as an indicator of ongoing abuse and may identify women at risk, providing a potential opportunity for intervention.