Effects of vasopressin in septic shock

Sesamol ameliorates hypotension by modulating cytokines and PPAR-gamma in systemic inflammatory response

Sepsis is one of the major causes of death reported in intensive care units. Acute kidney injury (AKI) and hypotension are important in the pathogenesis and mortality of systemic inflammatory response (SIR). Sesamol delays mortality in sepsis; however, its effects on AKI and hypotension and the role of peroxisome proliferator-activated receptor-ɣ (PPAR-γ) activation have not been established. We investigated the effect of sesamol on SIR in cecal ligation and puncture (CLP)-induced acute kidney injury and lipopolysaccharide (LPS)-induced hypotension in rats. Sesamol was subcutaneously injected 1 h after SIR. Renal function (BUN and CRE) and proinflammatory mediators interleukin (IL)-1β and IL-6 were increased after CLP. Tumor necrosis factor (TNF)-α, IL-1β, IL-10, and nitrite production were significantly increased 6 h after LPS-induced hypotension (mean arterial pressure was significantly decreased). Sesamol significantly inhibited BUN, CRE, IL-1β, IL-6, and nitrite after CLP-induced acute renal injury. In addition, sesamol increased mean arterial pressure and IL-10, inhibited TNF-α and IL-1β, but did not affect nitrite production in LPS-induced hypotension. Sesamol increased PPAR-γ in the leucocytes and peritoneal macrophages in LPS-induced SIR. We conclude that sesamol regulates leucocyte and macrophage PPAR-γ-associated systemic cytokines expression, thereby ameliorates acute kidney injury and hypotension in rats.

Pediatric sepsis and multiorgan dysfunction syndrome: progress and continued challenges

Sepsis, septic shock, systemic inflammatory response syndrome, and Multiorgan dysfunction syndrome (MODS) remain clinical challenges in pediatric critical care. Understanding of the immune response has increased greatly over the past decade, which has certainly increased the understanding of the pathophysiology and treatment of these conditions. The future promises more exciting discoveries as we understand cellular physiology, immunity, and host responses even better. This article reviews the current knowledge about sepsis and MODS in pediatric patients and discusses the best treatment modalities while highlighting the critical aspects of nursing care for this vulnerable population.

Mass spectrometry-based neuropeptidomics of secretory vesicles from human adrenal medullary pheochromocytoma reveals novel peptide products of prohormone processing

Neuropeptides are required for cell-cell communication in the regulation of physiological and pathological processes. While selected neuropeptides of known biological activities have been studied, global analyses of the endogenous profile of human peptide products derived from prohormones by proteolytic processing in vivo are largely unknown. Therefore, this study utilized the global, unbiased approach of mass spectrometry-based neuropeptidomics to define peptide profiles in secretory vesicles, isolated from human adrenal medullary pheochromocytoma of the sympathetic nervous system. The low molecular weight pool of secretory vesicle peptides was subjected to nano-LC-MS/MS with ion trap and QTOF mass spectrometry analyzed by different database search tools (InsPecT and Spectrum Mill). Peptides were generated by processing of prohormones at dibasic cleavage sites as well as at nonbasic residues. Significantly, peptide profiling provided novel insight into newly identified peptide products derived from proenkephalin, pro-NPY, proSAAS, CgA, CgB, and SCG2 prohormones. Previously unidentified intervening peptide domains of prohormones were observed, thus providing new knowledge of human neuropeptidomes generated from precursors. The global peptidomic approach of this study demonstrates the complexity of diverse neuropeptides present in human secretory vesicles for cell-cell communication.

Sepsis and septic shock: pathophysiological and cardiovascular background as basis for therapy

INTRODUCTION

Sepsis and septic shock are common causes for admission to intensive care units. The morbidity and mortality remain unacceptably high despite the advanced treatments.

OBJECTIVES

To review the most commonly reported underlying mechanisms of sepsis and septic shock, besides discussion of sepsis-induced cardiovascular dysfunction. Therapeutic strategies for sepsis-induced myocardial depression are briefly discussed.

DATA SYNTHESIS

The development of sepsis and septic shock is multifactorial. Two major mechanisms contribute to the haemodynamic collapse. The extrinsic and intrinsic mechanisms induce a complex cascade which results in the release of pro- and anti-inflammatory mediators. Sepsis develops when the initial, appropriate host response to an infection becomes amplified and then dysregulated leading to haemodynamic and circulatory changes. The pro-inflammatory mediators tumour necrosis factor alpha, interleukin-beta and nitric oxide play a significant role in sepsis-related hypotension, shock and depression of cardiomyocyte contractility. Septic cardiac dysfunction can be explained by various mechanisms: changes in circulating volume, down-regulation of beta-adrenergic receptors, depressed post-receptor signalling pathways, reduced calcium release from the sarcoplasmic reticulum and impaired electromechanical coupling and reduced calcium sensibility at the myofibrillar level. Mitochondrial derangement seems to be of great importance in tissue injury and sepsis-associated multi organ failure. There is no consistent protocol for treating sepsis and septic shock. Guidelines include early goal-directed therapy, source control and haemodynamic supportive measures.

CONCLUSION

Further studies are needed to distinguish the importance of these various mechanisms. We recommend that further investigational work should focus on the recovery of the mitochondria-related bio-energetic shut down as the mitochondria could play a key role in the understanding of apoptosis and protective measures. Understanding the pathophysiology of sepsis and septic shock will inevitably lead to a more accurate treatment of these still too often fatal syndromes.