Towards a Rigorous Network of Protein-Protein Interactions of the Model Sulfate Reducer Desulfovibrio vulgaris Hildenborough

Protein–protein interactions offer an insight into cellular processes beyond what may be obtained by the quantitative functional genomics tools of proteomics and transcriptomics. The aforementioned tools have been extensively applied to study Escherichia coli and other aerobes and more recently to study the stress response behavior of Desulfovibrio vulgaris Hildenborough, a model obligate anaerobe and sulfate reducer and the subject of this study. Here we carried out affinity purification followed by mass spectrometry to reconstruct an interaction network among 12 chromosomally encoded bait and 90 prey proteins based on 134 bait-prey interactions identified to be of high confidence. Protein-protein interaction data are often plagued by the lack of adequate controls and replication analyses necessary to assess confidence in the results, including identification of potential false positives. We addressed these issues through the use of biological replication, exponentially modified protein abundance indices, results from an experimental negative control, and a statistical test to assign confidence to each putative interacting pair applicable to small interaction data studies. We discuss the biological significance of metabolic features of D. vulgaris revealed by these protein-protein interaction data and the observed protein modifications. These include the distinct role of the putative carbon monoxide-induced hydrogenase, unique electron transfer routes associated with different oxidoreductases, and the possible role of methylation in regulating sulfate reduction

Pharmacokinetic considerations for pediatric patients receiving analgesia in the intensive care unit; targeting postoperative, ECMO and hypothermia patients

Adequate postoperative analgesia in pediatric patients in the intensive care unit (ICU) matters, since untreated pain is associated with negative outcomes. Compared to routine postoperative patients, children undergoing hypothermia (HT) or extracorporeal membrane oxygenation (ECMO), or recovering after cardiac surgery likely display non-maturational differences in pharmacokinetics (PK) and pharmacodynamics (PD). These differences warrant additional dosing recommendations to optimize pain treatment. Areas covered: Specific populations within the ICU will be discussed with respect to expected variations in PK and PD for various analgesics. We hereby move beyond maturational changes and focus on why PK/PD may be different in children undergoing HT, ECMO or cardiac surgery. We provide a stepwise manner to develop PK-based dosing regimens using population PK approaches in these populations. Expert opinion: A one-dose to size-fits-all for analgesia is suboptimal, but for several commonly used analgesics the impact of HT, ECMO or cardiac surgery on average PK parameters in children is not yet sufficiently known. Parameters considering both maturational and non-maturational covariates are important to develop population PK-based dosing advices as part of a strategy to optimize pain treatment.status: accepte

Enhanced engraftment of human myelofibrosis stem and progenitor cells in MISTRG mice

The engraftment potential of myeloproliferative neoplasms in immunodeficient mice is low. We hypothesized that the physiological expression of human cytokines (macrophage colony-stimulating factor, interleukin-3, granulocyte-macrophage colony-stimulating factor, and thrombopoietin) combined with human signal regulatory protein α expression in Rag2−/−Il2rγ−/− (MISTRG) mice might provide a supportive microenvironment for the development and maintenance of hematopoietic stem and progenitor cells (HSPC) from patients with primary, post–polycythemia or post–essential thrombocythemia myelofibrosis (MF). We show that MISTRG mice, in contrast to standard immunodeficient NOD.Cg-PrkdcscidIl2rgtm1Wjl/SzJ and Rag2−/−Il2rγ−/− mice, supported engraftment of all patient samples investigated independent of MF disease stage or risk category. Moreover, MISTRG mice exhibited significantly higher human MF engraftment levels in the bone marrow, peripheral blood, and spleen and supported secondary repopulation. Bone marrow fibrosis development was limited to 3 of 14 patient samples investigated in MISTRG mice. Disease-driving mutations were identified in all xenografts, and targeted sequencing revealed maintenance of the primary patient sample clonal composition in 7 of 8 cases. Treatment of engrafted mice with the current standard-of-care Janus kinase inhibitor ruxolitinib led to a reduction in human chimerism. In conclusion, the established MF patient-derived xenograft model supports robust engraftment of MF HSPCs and maintains the genetic complexity observed in patients. The model is suited for further testing of novel therapeutic agents to expedite their transition into clinical trials