56 research outputs found

    Efficacy of an Extracorporeal Endotoxin Adsorber System during Hyperdynamic Porcine Endotoxemia

    Get PDF
    Background: Endotoxemia is a crucial factor in the pathogenesis of sepsis. Elimination of endotoxin is aimed at the reduction of sepsis-related morbidity and lethality. The objective of this study was to examine the impact of an endotoxin adsorber on hemodynamics, O2 exchange and metabolism during resuscitated porcine endotoxemia. Methods: Twenty pigs were randomized into 2 intervention groups (n = 7 each) and 1 control group (n = 6). Endotoxemia was induced by continuous intravenous application of lipopolysaccharide for 8 h. Adsorber therapy was started at the same time as the induction of endotoxemia or 2 h later. An extracorporeal hemoperfusion device using immobilized human serum albumin for endotoxin adsorption was used. Results: Hemodynamic, metabolic and acid-base parameters, as well as the kinetics of interleukin (IL)-6, IL-8, IL-10 and tumor necrosis factor-α, were characteristic for endotoxic shock. Endotoxin plasma levels were low (arterial, hepatic and portal vein). None of the parameters were significantly influenced by the adsorber system. Conclusion: Despite typical clinical signs of endotoxemia, the adsorber system had no significant effect on hemodynamic, metabolic and acid-base parameters during endotoxic shock. The reasons for the absence of an effect are elusive; however, failure of the method per se or exceeded capacity of the adsorber cannot be excluded

    Circulating endothelial cells are an early predictor in renal cell carcinoma for tumor response to sunitinib

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Tyrosine kinase inhibitors (TKI) have enriched the therapeutic options in patients with renal cell carcinoma (RCC), which frequently induce morphological changes in tumors. However, only little is known about the biological activity of TKI. Circulating endothelial cells (CEC) have been associated with endothelial damage and, hence, may serve as a putative marker for the biological activity of TKI. The main objective of our study was to evaluate the predictive value of CEC, monocytes, and soluble vascular endothelial growth factor receptor (sVEGFR)-2 in RCC patients receiving sunitinib treatment.</p> <p>Methods</p> <p>Analyses of CEC, monocytes, and sVEGFR-2 were accomplished for twenty-six consecutive patients with metastatic RCC who received treatment with sunitinib (50 mg, 4 wks on 2 wks off schedule) at our institution in 2005 and 2006.</p> <p>Results</p> <p>In RCC patients CEC are elevated to 49 ± 44/ml (control 8 ± 8/ml; P = 0.0001). Treatment with sunitinib is associated with an increase in CEC within 28 days of treatment in patients with a Progression free survival (PFS) above the median to 111 ± 61 (P = 0.0109), whereas changes in patients with a PFS below the median remain insignificant 69 ± 61/ml (P = 0.1848). Monocytes and sVEGFR2 are frequently altered upon sunitinib treatment, but fail to correlate with clinical response, defined by PFS above or below the median.</p> <p>Conclusions</p> <p>Sunitinib treatment is associated with an early increase of CEC in responding patients, suggesting superior endothelial cell damage in these patients as a putative predictive biomarker.</p

    A Cooperative Interaction between Nontranslated RNA Sequences and NS5A Protein Promotes In Vivo Fitness of a Chimeric Hepatitis C/GB Virus B

    Get PDF
    GB virus B (GBV-B) is closely related to hepatitis C virus (HCV), infects small non-human primates, and is thus a valuable surrogate for studying HCV. Despite significant differences, the 5′ nontranslated RNAs (NTRs) of these viruses fold into four similar structured domains (I-IV), with domains II-III-IV comprising the viral internal ribosomal entry site (IRES). We previously reported the in vivo rescue of a chimeric GBV-B (vGB/IIIHC) containing HCV sequence in domain III, an essential segment of the IRES. We show here that three mutations identified within the vGB/IIIHC genome (within the 3′NTR, upstream of the poly(U) tract, and NS5A coding sequence) are necessary and sufficient for production of this chimeric virus following intrahepatic inoculation of synthetic RNA in tamarins, and thus apparently compensate for the presence of HCV sequence in domain III. To assess the mechanism(s) underlying these compensatory mutations, and to determine whether 5′NTR subdomains participating in genome replication do so in a virus-specific fashion, we constructed and evaluated a series of chimeric subgenomic GBV-B replicons in which various 5′NTR subdomains were substituted with their HCV homologs. Domains I and II of the GBV-B 5′NTR could not be replaced with HCV sequence, indicating that they contain essential, virus-specific RNA replication elements. In contrast, domain III could be swapped with minimal loss of genome replication capacity in cell culture. The 3′NTR and NS5A mutations required for rescue of the related chimeric virus in vivo had no effect on replication of the subgenomic GBneoD/IIIHC RNA in vitro. The data suggest that in vivo fitness of the domain III chimeric virus is dependent on a cooperative interaction between the 5′NTR, 3′NTR and NS5A at a step in the viral life cycle subsequent to genome replication, most likely during particle assembly. Such a mechanism may be common to all hepaciviruses

    The human keratins: biology and pathology

    Get PDF
    The keratins are the typical intermediate filament proteins of epithelia, showing an outstanding degree of molecular diversity. Heteropolymeric filaments are formed by pairing of type I and type II molecules. In humans 54 functional keratin genes exist. They are expressed in highly specific patterns related to the epithelial type and stage of cellular differentiation. About half of all keratins—including numerous keratins characterized only recently—are restricted to the various compartments of hair follicles. As part of the epithelial cytoskeleton, keratins are important for the mechanical stability and integrity of epithelial cells and tissues. Moreover, some keratins also have regulatory functions and are involved in intracellular signaling pathways, e.g. protection from stress, wound healing, and apoptosis. Applying the new consensus nomenclature, this article summarizes, for all human keratins, their cell type and tissue distribution and their functional significance in relation to transgenic mouse models and human hereditary keratin diseases. Furthermore, since keratins also exhibit characteristic expression patterns in human tumors, several of them (notably K5, K7, K8/K18, K19, and K20) have great importance in immunohistochemical tumor diagnosis of carcinomas, in particular of unclear metastases and in precise classification and subtyping. Future research might open further fields of clinical application for this remarkable protein family

    Identification of novel RNA secondary structures within the hepatitis C virus genome reveals a cooperative involvement in genome packaging

    Get PDF
    The specific packaging of the hepatitis C virus (HCV) genome is hypothesised to be driven by Core- RNA interactions. To identify the regions of the viral genome involved in this process, we used SELEX (systematic evolution of ligands by exponential enrichment) to identify RNA aptamers which bind specifically to Core in vitro. Comparison of these aptamers to multiple HCV genomes revealed the presence of a conserved terminal loop motif within short RNA stem-loop structures. We postulated that interactions of these motifs, as well as sub-motifs which were present in HCV genomes at statistically significant levels, with the Core protein may drive virion assembly. We mutated 8 of these predicted motifs within the HCV infectious molecular clone JFH-1, thereby producing a range of mutant viruses predicted to possess altered RNA secondary structures. RNA replication and viral titre were unaltered in viruses possessing only one mutated structure. However, infectivity titres were decreased in viruses possessing a higher number of mutated regions. This work thus identified multiple novel RNA motifs which appear to contribute to genome packaging. We suggest that these structures act as cooperative packaging signals to drive specific RNA encapsidation during HCV assembly

    Characterisation of reversed-phase liquid chromatographic columns by chromatographic tests. Evaluation of 36 test parameters: repeatability, reproducibility and correlation

    No full text
    The European Pharmacopoeia (Ph. Eur.) or other official compendia give only a general description of the stationary phase in the description of a liquid chromatographic method. Therefore the selection of a column giving suitable selectivity presents difficulties. Earlier, a test procedure was proposed that allows measurement of a number of parameters which are reported to be representative for stationary phase characteristics. This paper describes how the test procedure was applied on 69 RP-LC C18 columns. Chromatographic parameters obtained as test results were evaluated, and their repeatability, reproducibility and correlation were examined</p
    corecore