Meningococcal disease as a model to evaluate novel anti-sepsis strategies

Translational systems biology of inflammation: potential applications to personalized medicine

A central goal of industrialized nations is to provide personalized, preemptive and predictive medicine, while maintaining healthcare costs at a minimum. To do so, we must confront and gain an understanding of inflammation, a complex, nonlinear process central to many diseases that affect both industrialized and developing nations. Herein, we describe the work aimed at creating a rational, engineering-oriented and evidence-based synthesis of inflammation geared towards rapid clinical application. This comprehensive approach, which we call 'Translational Systems Biology', to date has been utilized for in silico studies of sepsis, trauma/hemorrhage/traumatic brain injury, acute liver failure and wound healing. This framework has now allowed us to suggest how to modulate acute inflammation in a rational and individually optimized fashion using engineering principles applied to a biohybrid device. We suggest that we are on the cusp of fulfilling the promise of in silico modeling for personalized medicine for inflammatory disease.

Deadly viral syndrome mimics

Upper respiratory tract infections (ie, "the common cold") have several hundred causes, the most common of which include rhino-virus, coronavirus, and respiratory syncytial virus. The clinical presentation varies with symptoms. Every emergency department, no matter what the demographics, cares for patients with this constellation of symptoms. Emergency physicians examine, diagnose, and treat these disorders frequently. With increasing burdens being placed on emergency physicians, it is possible to assume a diagnosis of upper respiratory tract infection without generating a complete differential diagnosis. The challenge is to identify and recognize the distinctions between an innocuous upper respiratory tract infection and a life-threatening disease "mimic" or entities. This article discusses some of these life-threatening mimics.

The immunopathogenesis of meningococcal disease

This review describes the mechanisms of the immune response to meningococcal disease, examining the extent to which individual variation of the immune response can determine susceptibility. It concludes by summarising the difficulties encountered by recent efforts to develop new immunomodulatory treatments.

Anti-septicaemic effect of polysaccharide from Panax ginseng by macrophage activation

The aim of the present research was conducted to elucidate anti-septicaemic effect of a polysaccharide (PS) isolated from Panax ginseng C.A. Meyer (Araliaceae) by nitric oxide production from stimulated macrophage. In vitro assays for the activity measurement of PS, NO production test with Greiss reagent, phagocytic activity test using zymosan and cytokines production test using ELISA kit were also conducted. In vivo anti-septicaemic activity was assessed by using C57BL/6J mice. This was done with Staphylococcus aureus infection test. PS used at 0.025 mg/kg concentration showed a potent anti-septicaemic activity (80%, survival). However, it did not directly inhibit S. aureus in a minimum inhibitory concentration (MIC) test, conducted in vitro (data not shown). Nitric oxide production via macrophage activation showed the highest value of 5.5 nmol/ml at 1 microg/ml PS. In in vitro phagocytic activity test, PS at 10 microg/ml concentration showed a potent phagocytic activity for zymosan with 167% of the control. Production of TNF-alpha by macrophage activation at 10 microg/ml of PS was 96% lysis of L929. Also production of IL-1 and IL-6 by stimulation of macrophage with 100 microg/ml PS dose increased to 235 pg/ml and 0.47 ng/ml, respectively. The low mortality of PS treated (0.025 mg/kg) infected mice was concurrent with decreased bacterial content in the blood. Nitric oxide production in S. aureus infected mice whose macrophage was stimulated by PS (0.025 mg/kg) increased approximately 4 times than the untreated S. aureus infected group at 24 and 48 h incubation. In the PS treated (0.025 mg/kg) group, the intracellular concentration of S. aureus in macrophages decreased approximately by 50%, compared with the untreated group. Combine treatment with PS (0.025 mg/kg body weight) and vancomycin (10 mg/kg B.W.) resulted in 100% survival of the animals, whereas only 67% or 50% of the animals survived, respectively, when treated with PS or vancomycin alone. These results suggest that PS from Panax ginseng possess a potent anti-septicaemic activity by stimulating macrophage and a potentiality as an immunomodulator against sepsis occurred by Staphylococcus aureus.

Animal models of sepsis

Knowledge of sepsis is growing rapidly and new pathogenetic concepts and therapeutic strategies evolve. The animal models of sepsis catalyze this development. Any model of this complex disease is inevitably a compromise between clinical realism and experimental simplification. Against the background of current pathogenetic concepts this review tries to analyze the validity and clinical relevance of each model. Endotoxemia and bacteremia represent models without an infectious focus. They reproduce many characteristics of sepsis and are highly controlled and standardized. However, they reflect a primarily systemic challenge and create neither an infectious focus nor the protracted immune reaction that characterizes sepsis. In this respect, any model with an infectious focus is decisively closer to clinical reality. In these models the peritoneal cavity is contaminated either by bacteria or inoculated feces or perforation of the bowel wall. Both the bolus injection and the implantation of carriers loaded with bacteria or feces are used. In fecal spesis and perforation models the complete spectrum of enteric pathogens is present in the septic focus and infective selection is undisturbed. Here the pathophysiologic and immunologic features of clinical sepsis are successfully reproduced. However, presumably due to inadequate control of the bacterial challenge, only poor interlaboratory standardization is possible. As to optimize models for the clinical reality the choice of an appropriate class of models is crucial. Moreover the incorporation of clinical therapy such as volume resuscitation, antibiotic therapy and surgical treatment of the septic focus is indispensable. Finally, the importance of simulation of comorbidities cannot be overemphasized.