T.A. Blinman

Early NF-κB activation is associated with hormone-induced pancreatitis

Inflammation and cell death are critical to pathogenesis of acute pancreatitis. Here we show that transcription factor nuclear factor-κB (NF-κB), which regulates these processes, is activated and plays a role in rat cerulein pancreatitis. NF-κB was strongly activated in the pancreas within 30 min of cerulein infusion; a second phase of NF-κB activation was prominent at 3-6 h. This biphasic kinetics could result from observed transient degradation of the inhibitory protein IκBα and slower but sustained degradation of IκBβ. The hormone also caused NF-κB translocation and IκB degradation in vitro in dispersed pancreatic acini. Both p65/p50 and p50/p50, but not c-Rel, NF-κB complexes were manifest in pancreatitis and in isolated acini. Coinfusion of CCK JMV-180, which abolishes pancreatitis, prevented cerulein-induced NF-κB activation. The second but not early phase of NF-κB activation was inhibited by a neutralizing tumor necrosis factor-α antibody. Antioxidant N-acetylcysteine (NAC) blocked NF-κB activation and significantly improved parameters of pancreatitis. In particular, NAC inhibited intrapancreatic trypsin activation and mRNA expression of cytokines interleukin-6 and KC, which were dramatically induced by cerulein. The results suggest that NF-κB activation is an important early event that may contribute to inflammatory and cell death responses in acute pancreatitis.

Kupffer cell blockade reduces hepatic and systemic cytokine levels and lung injury in hemorrhagic pancreatitis in rats.

Severe acute pancreatitis (AP) is associated with both the local (pancreatic) release of cytokines and an elevation in their systemic plasma concentrations. This may lead to organ dysfunction and death of the patient. The aims of this study were to investigate the source(s) of systemic cytokine production during experimental AP. Forty-two rats were allocated to five groups (control, sham operation and saline injection, sham operation and gadolinium chloride injection, intraductal sodium-taurocholate infusion and saline injection, or intraductal sodium-taurocholate infusion and gadolinium chloride injection). Blood from the iliac artery, portal vein, and hepatic vein, along with tissue from the pancreas, liver, and lung, were collected. Serum levels of TNF&agr;, IL-1&bgr;, IL-6, and IL-10 were determined by enzyme-linked immunosorbent assay. Tissue mRNA for IL-1&bgr; and IL-10 was assessed by reverse-transcription polymerase chain reaction. In untreated animals with AP, the lowest serum cytokine levels were found in the portal vein. In the hepatic vein, the levels of TNF&agr;, IL-1&bgr;, and IL-6 were higher. The highest serum levels were detected in the systemic circulation. In the gadolinium chloride-treated group, there was no increase in hepatic or systemic cytokine levels and less lung injury was observed. Extrapancreatic cytokine production from both the liver and the lung contributed significantly to systemic levels of TNF&agr;, IL-1&bgr;, IL-6, and IL-10 in this experimental model of AP.

Spinal immobilization on a flat backboard: Does it result in neutral position of the cervical spine?

STUDY OBJECTIVESnTo determine the amount of occipital padding required to achieve neutral position of the cervical spine when a patient is immobilized on a flat backboard. Neutral position was defined as the normal anatomic position of the head and torso that one assumes when standing looking straight ahead.nnnDESIGNnDescriptive with hypothesis testing of selected descriptive elements.nnnSETTINGnUniversity campus and hospital.nnnSUBJECTSnOne hundred healthy young adults with no history of back disease.nnnINTERVENTIONSnVolunteers were measured in standing and supine positions.nnnMEASUREMENTSnOccipital offset; height; weight; and head, neck, and chest circumferences were measured for each subject.nnnMAIN RESULTSnThe amount of occipital offset required to achieve neutral position varied from 0 to 3.75 in. (mean, 1.5 in.). Mean occipital offset for men (1.67 in.) was significantly greater than that for women (1.31 in.) Easily obtained body measurements did not accurately predict occipital offset.nnnCONCLUSIONnImmobilization on a flat backboard would place 98% of our study subjects in relative cervical extension. Occipital padding would place a greater percentage of patients in neutral position and increase patient comfort during transport.

Expression of cytokine and chemokine mRNA and secretion of tumor necrosis factor-α by gallbladder epithelial cells: Response to bacterial lipopolysaccharides

BackgroundIn addition to immune cells, many other cell types are known to produce cytokines. Cultured normal mouse gallbladder epithelial cells, used as a model system for gallbladder epithelium, were examined for their ability to express the mRNA of various cytokines and chemokines in response to bacterial lipopolysaccharide. The synthesis and secretion of the tumor necrosis factor-α (TNF-α) protein by these cells was also measured.ResultsUntreated mouse gallbladder cells expressed mRNA for TNF-α, RANTES, and macrophage inflammatory protein-2 (MIP-2). Upon treatment with lipopolysaccharide, these cells now produced mRNA for Interleukin-1β (IL-1β), IL-6, monocyte chemoattractant protein-1 (MCP-1), and showed increased expression of TNF-α and MIP-2 mRNA. Untreated mouse gallbladder cells did not synthesize TNF-α protein; however, they did synthesize and secrete TNF-α upon treatment with lipopolysaccharide.MethodsCells were treated with lipopolysaccharides from 3 strains of bacteria. Qualitative and semi-quantitative RT-PCR, using cytokine or chemokine-specific primers, was used to measure mRNA levels of TNFα, IL-1β, IL-6, IL-10, KC, RANTES, MCP-1, and MIP-2. TNF-α protein was measured by immunoassays.ConclusionThis research demonstrates that gallbladder epithelial cells in response to lipopolysaccharide exposure can alter their cytokine and chemokine RNA expression pattern and can synthesize and secrete TNFα protein. This suggests a mechanism whereby gallbladder epithelial cells in vivo may mediate gallbladder secretory function, inflammation and diseases in an autocrine/paracrine fashion by producing and secreting cytokines and/or chemokines during sepsis.

Hepatic contribution to circulating cytokine levels in severe acute pancreatitis in rats

The inflamed pancreas is one source of cytokine release during acute pancreatitis (AP). However, cytokines from other sites (e.g. liver or lung) may contribute to the multi-organ dysfunction syndrome that complicates severe AP. In this study, we determined the relative contributions of various possible sites during AP in rats. METHODS: 24 female rats were randomly allocated to 3 groups. A: control group (n=6); B: sham operation (intraductal saline infusion) (n=8); C: AP (intraductal infusion of 5% sodium-taurocholate) (n=10). Intraductal infusions were pressure ( < 20mmHg) and volume (0.5ml) controlled. Control animals were sacrificed at time zero. All other animals were sacrificed 2 hours after intraductal infusion. Blood samples were taken selectively from the iliac artery, the portal and hepatic vein. Cytokines were determined by rat specific ELISA. Endotoxin, since it is a potent stimulator of cytokine production, was assessed by a Limulus Amoebocyte Lysate assay. Histologic changes in the pancreas were scored in a blinded fashion (0 to 22, normal to most abnormal) by two investigators. Statistics: One way ANOVA or Mann-Whitney U-test. RESULTS: No cytokines were detectable in the control or sham group and no endotoxin was detectable in any serum sample. Histology confirmed hemorrhagic pancreatitis in group C (p < 0.001 vs group A or B). Cytokine values in pg/ml are mean ± SEM in group C: