A Localizing Circumferential Compression Device Delayed Death After Artificial Eastern Diamondback Rattlesnake Envenomation to the Torso of an Animal Model in a Pilot Study

Nearly all prior studies to delay onset of systemic toxicity and death after snake bite use a model of distal extremity envenomation. In the first of a series of planned studies using snake venoms with different toxicity profiles, the application of a novel device in a new model of torso envenomation in the setting of Eastern Coral Snake (Micrurus fulvius) venom (a potent neurotoxin) envenomation showed promise by delaying systemic intoxication. In this pilot study, we investigated this novel localizing circumferential compression (LoCC) device’s ability to delay onset of life threatening systemic toxicity after Eastern Diamondback Rattlesnake (Crotalus adamanteus) envenomation, a potent hemotoxic and myotoxic venom. With university approval, four juvenile female pigs (22–25 kg) were anesthetized, sedated, and intubated but not paralyzed to allow for spontaneous respirations. Each animal was injected subcutaneously with 50 mg of C. adamanteus venom in identical preselected areas of the trunk. After 1 min, two treatment animals had the LoCC device applied; two control animals had no intervention. Vital signs were recorded every 10 min for the first 2 h and every 30 min thereafter. Endpoints included cardiovascular collapse (fatal arrhythmia, loss of mean arterial pressure, or pulse) or respiratory arrest (<3 breaths/min, saturation < 80%) or survival to 7 h. The pigs in the treatment group reached an endpoint at an average time of 355 (±65) min compared with control 32 (±3.5) min (p < 0.04). In this pilot study, the LoCC device significantly delayed onset of systemic symptoms and death after torso envenomation with Eastern Diamondback Rattlesnake venom in this model.     

Adrenocorticotropic hormone and cortisol levels in relation to inflammatory response and disease severity in children with meningococcal disease.

This prospective observational study investigated the relationship of the hypothalamic-pituitary-adrenal axis to inflammatory markers and to disease severity in children with meningococcal disease. In total, 32 children were studied: 10 with distinct meningococcal meningitis (MM), 10 with MM and septic shock, and 12 with fulminant meningococcal septicemia (FMS). Levels of adrenocorticotropic hormone (ACTH) and interleukin (IL)-6, IL-8, and IL-10 were lowest in the MM group and dramatically elevated in the FMS group. Cortisol and C-reactive protein levels were highest in the MM group and relatively low in the FMS group. Levels of ACTH and inflammatory markers decreased within the first 24 h of admission, but cortisol levels did not fluctuate. Cortisol was significantly inversely correlated with IL-6, IL-8, and IL-10 (P < or =.04). These results suggest that the adrenal reserve in children is insufficient to handle the extreme conditions and stress associated with severe meningococcal disease.     

In vitro interaction of C1-inhibitor with thrombin.

Previous observations of increased generation of thrombin during acute attacks of angioedema in plasma of patients with C1-inhibitor (C1-INH) deficiency prompted us to evaluate the interaction of C1-INH with thrombin in both purified systems and human plasma. For this purpose, we used several methods: (1) sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblotting analysis; (2) enzyme-linked immunosorbent assays to measure complexes between C1-INH and thrombin and inactivated C1-INH; and (3) kinetic studies using a chromogenic assay. We found that the interaction of purified C1-INH with thrombin is associated with the formation of bimolecular complexes of molecular weight (Mr) 130 000 and 120 000 as well as with the appearance of a cleaved form of C1-INH of Mr 97 000. The kinetic studies of inhibition of thrombin by C1-INH showed an average second-order rate constant of 19/s per mol/l, which was significantly increased in the presence of heparin. The addition of thrombin to human plasma was not associated with detectable C1-INH-thrombin complex formation or with cleavage of C1-INH. In conclusion, our data demonstrate that C1-INH upon interaction with thrombin, in part, forms enzyme-inhibitor complexes and, in part, is cleaved. The low second-order rate constant and the lack of a significant interaction in plasma suggest that the inhibition of thrombin by C1-INH has a minor role in circulating blood; however, its role might be important at the endothelial surface, where high concentrations of glycosaminoglycans occur.     

Detection of activation of the contact system of coagulation in vitro and in vivo: quantitation of activated Hageman factor-C-1-inhibitor and kallikrein-C-1-inhibitor complexes by specific radioimmunoassays

Radioimmunoassays (RIAs) for the detection of C-1-inhibitor (C-1-Inh) complexed to either kallikrein or activated Hageman factor (factor XIIa) are described. Kallikrein-C-1-Inh or factor XIIa-C-1-Inh complexes were bound to Sepharose to which monospecific antibodies against (pre)kallikrein or factor XII, respectively, were coupled. Bound complexes were subsequently detected by an incubation with affinity purified 125I-labeled antibodies against C-1-Inh. These RIAs were used to detect activation of the contact system of coagulation in vitro and in vivo. Addition of dextran sulfate (DXS) (20 micrograms/ml) to fresh plasma resulted at 37 degrees C in the rapid generation of amidolytic kallikrein activity, which was maximal after 1 to 2 min of incubation and subsequently decreased within a few minutes. The generation of kallikrein activity coincided with the appearance of both kallikrein-C-1-Inh and factor XIIa-C-1-Inh complexes. However, in contrast to kallikrein activity, both types of complexes remained detectable in the incubation mixtures during the incubation period. Experiments with purified kallikrein. C-1-Inh and partly purified beta-factor XIIa, and activation experiments in plasmas deficient in either factor XII or prekallikrein, demonstrated the specificity of both RIAs. The minimal amount of DXS that resulted in the generation of measurable amounts of both types of complexes in plasma was 2-3 micrograms per ml. Similar experiments with kaolin showed that with limiting amounts of activator (1-2 mg/ml), only kallikrein-C-1-Inh complexes were detected in plasma. When larger amounts of kaolin were added to plasma, factor XIIa-C-1-Inh complexes were additionally detected in plasma.(ABSTRACT TRUNCATED AT 250 WORDS)     

Influence of psychological stress on physical pain

The goal of this study was to determine the influence of psychological stress on non‐pathologic physical pain in a general population. Data pertaining to the source of, response to, and coping with stress, as well as site and intensity of pain was collected on 91 non‐patient subjects using a self‐report questionnaire. The questionnaire consisted of a Global Assessment of Recent Stress, Stress Response Inventory and Ways of Coping Checklist, in addition to the Site and Intensity of Stress‐Related Pain. It was found that the degree of stress was proportional to the pain severity. Also, the degree of responses to stress and coping style played a role in pain severity. Moreover, economic status, stress from sickness or injury, and somatization were the best predictors of the pain severity in our study population. The most common stress‐related pain was occipital headache, and the pain sites were dependent on certain stress variables. The high pain group and no pain group showed distinct demographic and stress profiles. The various aspects of psychological stress affect the incidence, site and intensity of physical pain. Copyright © 2008 John Wiley & Sons, Ltd.     

Hyperammonemia and Coma without Hepatic Dysfunction Induced by Valproate Therapy

The authors report a case of a 41-year-old mentally disabled man with bipolar disorder who presented to the emergency department with altered mental status. He was found to have a significantly elevated ammonia level (377 microM/L) with no signs of hepatic insufficiency. His coma and hyperammonemia were attributed to his chronic valproate therapy. This patient had the highest serum ammonia level ever reported with a therapeutic valproate level in the absence of any other anticonvulsant therapy, metabolic abnormality, or hepatic dysfunction. The authors discuss this case and review the current literature on hyperammonemia in valproic acid therapy and the use of L-carnitine in these patients.     

Coagulopathy following major liver resection: the effect of rBPI21 and the role of decreased synthesis of regulating proteins by the liver

This prospective study investigated the role of reduced hepatic synthesis of regulating proteins in coagulopathy after partial hepatectomy (PH) compared with major abdominal surgery (MAS) without involvement of the liver. Furthermore, we studied the effect of rBPI21, an endotoxin-neutralizing agent, on coagulopathy after PH was studied. Compared with MAS, PH resulted in significantly elevated levels of thrombin-antithrombin-III and plasmin-alpha2-antiplasmin complexes. Levels of antithrombin-3, alpha2-antiplasmin, fibrinogen, plasminogen, alpha2-macroglobulin (alpha2-M), and C1-inhibitor remained lower following PH. Treatment with rBPI21 led to significantly lower levels of tissue-type plasminogen activator (t-PA). Post-operative disseminated intravascular coagulation (DIC) was associated with significantly higher bilirubin and t-PA plasma levels and significantly lower levels of alpha2-M. This study indicates that PH induced hepatic failure results in decreased synthesis of hepatic regulating plasma proteins and subsequent activation of coagulation and fibrinolysis. Prevention of t-PA release by rBPI21 may have important clinical implications. Decreased availability of alpha2-M may be a factor in post-operative DIC.     

Wegener's granulomatosis autoantibodies identify a novel diisopropylfluorophosphate-binding protein in the lysosomes of normal human neutrophils

Anti-neutrophil cytoplasmic autoantibodies (ANCA) specifically associated with Wegener's granulomatosis were found to be directed against a saline-soluble glycoprotein triplet that migrates on SDS gels as distinct bands of Mr 29,000, 30,500, and 32,000 and is present in the azurophilic granules. This antigen was specifically recognized by all cytoplasmic-staining (C)-ANCA-positive sera from patients with Wegener's disease. C-ANCA antigen bound [3H]diisopropylfluorophosphate, which indicates that it is a serine protease, but it could clearly be distinguished from the serine proteases elastase and cathepsin G. Stimulation of cytochalasin B-treated neutrophils with FMLP induced release of C-ANCA antigen. This indicates that in vivo C-ANCA might interact with the C-ANCA antigen after its release upon inflammatory stimulation. We further demonstrate that in some perinuclear staining (P-ANCA) patients' sera autoantibodies against other myeloid lysosomal enzymes can be detected, such as antimyeloperoxidase and antielastase. C-ANCA and P-ANCA thus represent a novel class of autoantibodies directed against myeloid lysosomal enzymes. The originally described Wegener-specific C-ANCA show an apparently uniform specificity for the 29,000 serine protease. In contrast, P-ANCA may recognize myeloperoxidase as well as elastase and/or other antigens.