Effects of Bioreactor‐Oxygenation During Extracorporeal Granulocytes Treatment in Septic Patients

A granulocyte bioreactor for the extracorporeal treatment was developed to enhance the immune cell function in patients with severe sepsis. The influence of oxygenation on the used cells was tested in a prospective clinical study. Ten patients with severe sepsis were treated twice with the granulocyte bioreactor. The used cells were screened for functionality; values of blood gases, glucose and lactate were obtained from the recirculating bioreactor circuit. Five patients were treated with an oxygenator setup (Oxy group), five without oxygenator (Non‐Oxy group). The overall in‐hospital mortality was 50%. Significantly lower values of oxygen saturation, partial oxygen pressure, lactate, oxyburst and phagocytosis were seen in the Non‐Oxy group compared with the Oxy group in the bioreactor circuit. Further studies with this approach are encouraged and should focus on the influence of oxygenation on production of reactive oxygen species and cytokines of used cells.     

Use of Human Preconditioned Phagocytes for Extracorporeal Immune Support: Introduction of a Concept

Abstract: Neutrophils are critical effector cells in humoral and innate immunity and play a vital role in phagocytosis and bacterial killing. If they and/or their specific functions are lacking, then immunoparalysis may occur, and severe diseases like systemic inflammatory response syndrome (SIRS) or sepsis can take a fatal course. In this paper, we discuss the possibility of using preconditioned cells in an extracorporeal biohybrid immune support system. A human promyelocytic cell line was stimulated for different times with all‐trans retinoic acid. The resulting cells displayed major signs and functions of mature neutrophilic granulocytes including oxygen radical production, phagocytosis of living and dead Escherichia coli, Staphylococcus aureus, Candida albicans, intracellular killing, and interleukin production. The cells can be expanded to yield a sufficient cell mass, and subsequent prestimulation results in an expression of specific neutrophil functions. Extracorporeal bioreactor experiments seem to be feasible to test the benefit in immunoparalysis‐associated diseases like SIRS or sepsis.     

Neonatal hyperoxia contributes additively to cigarette smoke-induced chronic obstructive pulmonary disease changes in adult mice

The extent by which early postnatal lung injury contributes to the development of chronic obstructive pulmonary disease (COPD) in the adult is unclear. We hypothesized that exposure to hyperoxia during early postnatal life can augment lung changes caused by adult chronic cigarette smoke (CS) exposure. C57BL/6J mice (1 d old) were exposed to hyperoxia (O(2)) for 5 days. At 1 month of age, half of the O(2)-exposed mice and half of the control mice were placed in a CS chamber for 6 months. After exposure to CS, mice underwent quasi-static pressure-volume curve and mean chord length measurements; quantification of pro-Sp-c expression; and measurement of lung IL-8/ KC, CXCR2/IL8Rα, TNF-α, and IL-6 mRNA by real-time PCR. Adult mice exposed to O(2)+CS had significantly larger chord length measurements (P < 0.02) and lung volumes at 35 cm H(2)O (P < 0.05) compared with all other groups. They also had significantly less pro-Sp-c protein and surfactant protein C mRNA expression (P < 0.003). Mice exposed to O(2)+CS and CS-only mice had significantly higher lung resistance and longer mean time constants (P < 0.01), significantly more inflammatory cells in the bronchoalveolar lavage fluid (P < 0.03), and significantly higher levels of lung CXCR2/IL8Rα mRNA compared with mice not exposed to smoke (P < 0.02). We conclude that exposure to early postnatal hyperoxia contributed additively to CS-induced COPD changes in adult mice. These results may be relevant to a growing population of preterm children who sustained lung injury in the newborn period and may be exposed to CS in later life.     

Extracorporeal liver support-albumin dialysis with the Molecular Adsorbent Recirculating System (MARS)

Extracorporeal liver support has been a much studied topic throughout the last 50 years. Albumin dialysis as a therapeutic option for patients with acute liver failure or acute decompensation of chronic liver disease was introduced in the mid-nineties. The Molecular Adsorbent Recirculating System (MARS) is based on the concept of albumin dialysis and allows for the removal of protein-bound as well as water-soluble toxins. Besides its role as a sufficient volume expander human serum albumin is an important scavenger for molecules with pathophysiological relevance in liver failure. Albumin dialysis enables the selective regeneration of patient's albumin resulting in an increase of albumin binding capacity. Clinically, an improvement of central and local hemodynamics as well as liver-, brain-, and kidney-functions were observed. Thus, the treatment can contribute to liver regeneration and stabilization of vital organ functions and thus help to bridge patients to liver transplantation or to recovery of native liver function. Proper patient selection is critical for clinical success. Aggressive treatment of infections and sepsis seems to be a decisive pre-requisite for its safe and efficient use. Cautious anticoagulation with heparin is the common standard. Citrate use is recommended for patients prone to bleeding. Today, albumin dialysis MARS is among the best studied liver support methods. It appears as a valuable therapeutic tool for the treatment of various complications of of liver failure, especially hemodynamic instability and hepatic encephalopathy. Further studies will need to help defining the optimal patient selection and technical process parameters such as session length and frequency of treatment.     

Antiviral activity of the proteasome inhibitor VL-01 against influenza A viruses

The appearance of highly pathogenic avian influenza A viruses of the H5N1 subtype being able to infect humans and the 2009 H1N1 pandemic reveals the urgent need for new and efficient countermeasures against these viruses. The long-term efficacy of current antivirals is often limited, because of the emergence of drug-resistant virus mutants. A growing understanding of the virus-host interaction raises the possibility to explore alternative targets involved in the viral replication. In the present study we show that the proteasome inhibitor VL-01 leads to reduction of influenza virus replication in human lung adenocarcinoma epithelial cells (A549) as demonstrated with three different influenza virus strains, A/Puerto Rico/8/34 (H1N1) (EC₅₀ value of 1.7 μM), A/Regensburg/D6/09 (H1N1v) (EC₅₀ value of 2.4 μM) and A/Mallard/Bavaria/1/2006 (H5N1) (EC₅₀ value of 0.8 μM). In in vivo experiments we could demonstrate that VL-01-aerosol-treatment of BALB/c mice with 14.1 mg/kg results in no toxic side effects, reduced progeny virus titers in the lung (1.1 ± 0.3 log₁₀ pfu) and enhanced survival of mice after infection with a 5-fold MLD₅₀ of the human influenza A virus strain A/Puerto Rico/8/34 (H1N1) up to 50%. Furthermore, treatment of mice with VL-01 reduced the cytokine release of IL-α/β, IL-6, MIP-1β, RANTES and TNF-α induced by LPS or highly pathogen avian H5N1 influenza A virus. The present data demonstrates an antiviral effect of VL-01 in vitro and in vivo and the ability to reduce influenza virus induced cytokines and chemokines.     

Biocompatibility Assessment of Peritoneal Dialysis Solutions With a New In Vitro Model of Preconditioned Human HL60 Cells

The purposes of this study were to test the human promyelocytic cell line HL60 for its usability as a new cell model for the immune barrier of the peritoneum, and to investigate the impact of different peritoneal dialysis (PD) solutions in the model. HL60 cells were stimulated by retinoic acid and recombinant human granulocyte and macrophage colony-stimulating factor to differentiate into neutrophilic granulocytes. Cells were incubated in different commercially available PD solutions. After a 4-h incubation, functional (chemiluminescence phagocytosis) and viability tests (Live-Dead, XTT) were performed. High glucose concentrations (>1.36%) and low pH values (<7.0) appeared to be detrimental for neutrophil functions and for neutrophil viability. There is a quantitative correlation between glucose concentration and the cytotoxicity of standard PD solutions (PD 1.36% glucose shows 42.6% higher chemiluminescence than PD 3.86% glucose [ P  < 0.05]). PD solution containing icodextrin shows 74.3% higher chemiluminescence than PD 3.86% glucose, and PD solution with amino acids shows 52.4% higher chemiluminescence than PD 3.86% glucose which is a sign for better biocompatibility in these tests ( P  < 0.05). The test system is useful for biocompatibility investigations of PD solutions and their effect on immune cells, for example, neutrophil granulocytes. It does not depend on donor variability and availability in comparison to models based on primary isolated leukocytes.     

Impaired cell functions of hepatocytes incubated with plasma of septic patients

Objective and design  

The development of liver failure is a major problem in septic patients. In this prospective clinical experimental study the hepatotoxicity of plasma from septic and non-septic patients was tested.     

Duration of deep inspiration and subsequent airway constriction in vivo.

The effects of a deep inspiration (DI) in asthmatics differ from those observed in healthy subjects. When considering the effects of a DI, an implicit assumption is that all the airways are distending at the same rate as the lung parenchyma. However, with such rapid lung inflation, the ability of contracted airways to dynamically follow the lung parenchyma was recently shown to significantly lag the lung inflation. Another potentially important variable in the response of the individual airways to a DI that has not been well studied is the duration of the DI maneuver. The current study examines the effects of increasing duration at TLC during a DI on subsequent airway caliber. In five anesthetized and ventilated mongrel dogs, after DIs of increasing duration, changes in airway size were measured over the subsequent 5-minute period using high-resolution computed tomography. Results show that the duration of the maneuver is extremely important, leading to a qualitative change in the airway response. A long DI (> or = 30 seconds) caused subsequent airway dilation, while a shorter DI (< 30 seconds) caused bronchoconstriction. The precise mechanism underlying these observations is uncertain but seems to be related to intrinsic properties within the contracted airway smooth muscle.