The use of angiotensin II for the treatment of post-cardiopulmonary bypass vasoplegia

Purpose Vasoplegia is a common complication after cardiac surgery and is related to the use of cardiopulmonary bypass (CPB). Despite its association with increased morbidity and mortality, no consensus exists in terms of its treatment. In December 2017, angiotensin II (AII) was approved by the Food and Drug Administration (FDA) for use in vasodilatory shock; however, except for the ATHOS-3 trial, its use in vasoplegic patients that underwent cardiac surgery on CPB has mainly been reported in case reports. Thus, the aim of this review is to collect all the clinically relevant data and describe the pharmacologic mechanism, efficacy, and safety of this novel pharmacologic agent for the treatment of refractory vasoplegia in this population. Methods Two independent reviewers performed a systematic search in PubMed, Embase, Web of Science, and Cochrane Library using relevant MeSH terms (Angiotensin II, Vasoplegia, Cardiopulmonary Bypass, Cardiac Surgical Procedures). Results The literature search yielded 820 unique articles. In total, 9 studies were included. Of those, 2 were randomized clinical trials (RCTs) and 6 were case reports and 1 was a retrospective cohort study. Conclusions AII appears to be a promising means of treatment for patients with post-operative vasoplegia. It is demonstrated to be effective in raising blood pressure, while no major adverse events have been reported. It remains uncertain whether this agent will be broadly available and whether it will be more advantageous in the clinical management of vasoplegia compared to other available vasopressors. For that reason, we should contain our eagerness and enthusiasm regarding its use until supplementary knowledge becomes available.Thoracic Surger

Cardiac and Vascular α1-Adrenoceptors in Congestive Heart Failure: A Systematic Review

As heart failure (HF) is a devastating health problem worldwide, a better understanding and the development of more effective therapeutic approaches are required. HF is characterized by sympathetic system activation which stimulates α- and β-adrenoceptors (ARs). The exposure of the cardiovascular system to the increased locally released and circulating levels of catecholamines leads to a well-described downregulation and desensitization of β-ARs. However, information on the role of α-AR is limited. We have performed a systematic literature review examining the role of both cardiac and vascular α1-ARs in HF using 5 databases for our search. All three α1-AR subtypes (α1A, α1B and α1D) are expressed in human and animal hearts and blood vessels in a tissue-dependent manner. We summarize the changes observed in HF regarding the density, signaling and responses of α1-ARs. Conflicting findings arise from different studies concerning the influence that HF has on α1-AR expression and function; in contrast to β-ARs there is no consistent evidence for down-regulation or desensitization of cardiac or vascular α1-ARs. Whether α1-ARs are a therapeutic target in HF remains a matter of debate

Comparative Genomics of Mycoplasma: Analysis of Conserved Essential Genes and Diversity of the Pan-Genome

Mycoplasma, the smallest self-replicating organism with a minimal metabolism and little genomic redundancy, is expected to be a close approximation to the minimal set of genes needed to sustain bacterial life. This study employs comparative evolutionary analysis of twenty Mycoplasma genomes to gain an improved understanding of essential genes. By analyzing the core genome of mycoplasmas, we finally revealed the conserved essential genes set for mycoplasma survival. Further analysis showed that the core genome set has many characteristics in common with experimentally identified essential genes. Several key genes, which are related to DNA replication and repair and can be disrupted in transposon mutagenesis studies, may be critical for bacteria survival especially over long period natural selection. Phylogenomic reconstructions based on 3,355 homologous groups allowed robust estimation of phylogenetic relatedness among mycoplasma strains. To obtain deeper insight into the relative roles of molecular evolution in pathogen adaptation to their hosts, we also analyzed the positive selection pressures on particular sites and lineages. There appears to be an approximate correlation between the divergence of species and the level of positive selection detected in corresponding lineages

Complete Genome Sequence of Mycoplasma suis and Insights into Its Biology and Adaption to an Erythrocyte Niche

Mycoplasma suis, the causative agent of porcine infectious anemia, has never been cultured in vitro and mechanisms by which it causes disease are poorly understood. Thus, the objective herein was to use whole genome sequencing and analysis of M. suis to define pathogenicity mechanisms and biochemical pathways. M. suis was harvested from the blood of an experimentally infected pig. Following DNA extraction and construction of a paired end library, whole-genome sequencing was performed using GS-FLX (454) and Titanium chemistry. Reads on paired-end constructs were assembled using GS De Novo Assembler and gaps closed by primer walking; assembly was validated by PFGE. Glimmer and Manatee Annotation Engine were used to predict and annotate protein-coding sequences (CDS). The M. suis genome consists of a single, 742,431 bp chromosome with low G+C content of 31.1%. A total of 844 CDS, 3 single copies, unlinked rRNA genes and 32 tRNAs were identified. Gene homologies and GC skew graph show that M. suis has a typical Mollicutes oriC. The predicted metabolic pathway is concise, showing evidence of adaptation to blood environment. M. suis is a glycolytic species, obtaining energy through sugars fermentation and ATP-synthase. The pentose-phosphate pathway, metabolism of cofactors and vitamins, pyruvate dehydrogenase and NAD+ kinase are missing. Thus, ribose, NADH, NADPH and coenzyme A are possibly essential for its growth. M. suis can generate purines from hypoxanthine, which is secreted by RBCs, and cytidine nucleotides from uracil. Toxins orthologs were not identified. We suggest that M. suis may cause disease by scavenging and competing for host' nutrients, leading to decreased life-span of RBCs. In summary, genome analysis shows that M. suis is dependent on host cell metabolism and this characteristic is likely to be linked to its pathogenicity. The prediction of essential nutrients will aid the development of in vitro cultivation systems

Unexpected negative results for CytoSorb during left ventricular assist device implantation; interpret with caution

Thoracic Surger

Investigating the potential for energy, fuel, materials and chemicals production from corn residues (cobs and stalks) by non-catalytic and catalytic pyrolysis in two reactor configurations

The results of thermogravimetric analysis (TGA), non-catalytic and catalytic pyrolysis of corn cobs and corn stalks are reported in this paper. Pyrolysis took place in two different reactor configurations for both feedstocks: (1) fast pyrolysis in a captive sample reactor; and (2) non-catalytic slow pyrolysis and catalytic pyrolysis in a fixed-bed reactor. Experiments were carried out in atmospheric pressure at three temperatures: low temperature (360-380 °C), medium temperature (500-600 °C) and at high temperature (600-700 °C). The results of the experimental study were compared with data reported in the literature. Investigating the potential of corn residues for energy, fuel, materials and chemicals production according to their thermochemical treatment products yields and quality, it can be stated that: (a) corn stalks could be suitable raw material for energy production via gasification at high temperature, due to their medium low heating value (LHV) of pyrolysis gas (13-15 MJ/m3); (b) corn cob could be a good solid biofuel, due to the high LHV (24-26 MJ/kg) of the produced char; (c) additionally, corn cobs could be a good material for activated carbon production after being activated or gasified with steam, due to its high fixed carbon content(~74 wt%); (d) liquid was the major pyrolysis product from catalytic pyrolysis (about 40-44 wt% on biomass) for both feedstocks; further analysis of the organic phase of the liquid products were hydrocarbons and phenols, which make them interesting for chemicals production.Pyrolysis Catalytic pyrolysis Captive sample reactor Fixed-bed reactor Corn cob Corn stalks

Prevention of vasoplegia with CytoSorb in heart failure patients undergoing cardiac surgery (CytoSorb-HF trial): protocol for a randomised controlled trial

Introduction Vasoplegia is a common complication after cardiac surgery and is associated with poor prognosis. It is characterised by refractory hypotension despite normal or even increased cardiac output. The pathophysiology is complex and includes the systemic inflammatory response caused by cardiopulmonary bypass (CPB) and surgical trauma. Patients with end-stage heart failure (HF) are at increased risk for developing vasoplegia. The CytoSorb adsorber is a relatively new haemoadsorption device which can remove circulating inflammatory mediators in a concentration based manner. The CytoSorb-HF trial aims to evaluate the efficacy of CytoSorb haemoadsorption in limiting the systemic inflammatory response and preventing postoperative vasoplegia in HF patients undergoing cardiac surgery with CPB. Methods and analysis This is an investigator-initiated, single-centre, randomised, controlled clinical trial. In total 36 HF patients undergoing elective cardiac surgery with an expected CPB duration of more than 120 min will be randomised to receive CytoSorb haemoadsorption along with standard surgical treatment or standard surgical treatment alone. The primary endpoint is the change in systemic vascular resistance index with phenylephrine challenge after CPB. Secondary endpoints include inflammatory markers, sublingual microcirculation parameters and 30-day clinical indices. In addition, we will assess the cost-effectiveness of using the CytoSorb adsorber. Vascular reactivity in response to phenylephrine challenge will be assessed after induction, after CPB and on postoperative day 1. At the same time points, and before induction and on postoperative day 4 (5 time points in total), blood samples will be collected and the sublingual microcirculation will be recorded. Study participants will be followed up until day 30.Ethics and dissemination The trial protocol was approved by the Medical Ethical Committee of Leiden The Hague Delft (METC LDD, registration number P20.039). The results of the trial will be published in peer-reviewed medical journals and through scientific conferences.Thoracic Surger

Influence of surface state on the electrochemical performance of nickel-based cermet electrodes during steam electrolysis

International audienceDue to their fuel flexibility and high efficiency, solid oxide cells are apromising technology for sustainable energy production and storage. Nickel incombination with yttria-stabilized zirconia (YSZ) or gadolinium-doped ceria (GDC),forming Ni-YSZ or Ni-GDC cermets respectively, are the most widely adoptedelectrodes in solid oxide fuel cell fabrication. Currently, there is an increasing interestin cermet electrodes for hydrogen generation through high temperature steamelectrolysis using solid oxide electrolysis cells (SOECs). However, durability remainsa major issue for reliable operation of SOEC systems. A variety of processesaccountable for permanent performance degradation of SOECs has been identifiedbased on post-mortem cell analysis. Besides, transient/reversible degradationprocesses are typically examined by indirect methods, like impedance spectroscopy.The reason is that the application of material characterization techniques duringSOEC operational conditions is challenging. In this work we provide a directcorrelation between Ni-YSZ and Ni-GDC electrode surface oxidation states and their performance during steam electrolysisusing operando experimental evidence provided by near ambient pressure X-ray photoelectron and near edge X-ray absorptionfine structure spectroscopy. We show that nickel surface oxidation may induce significant performance degradation in Ni-YSZcathodes while, on the contrary, having minor effects in Ni-GDC. Remarkably, we found that in the case of Ni-GDC electrodes,small modification of the GDC oxidation state can have an important impact on the electrolysis performance. The resultshighlight the crucial role of the cathode electrode surface oxidation state on the SOEC functionality and have potentialimplications for the design and operation strategies of more efficient and durable SOEC devices