60 research outputs found
Drugs targeting the bone microenvironment: new therapeutic tools in Ewing's sarcoma?
Introduction: Ewing's sarcoma (ES) is the second most frequent malignant primary bone tumour in children, adolescents and young adults. The overall survival is 60 â 70% at 5 years but still very poor for patients with metastases, disease relapse or for those not responding to chemotherapy. For these high risk patients, new therapeutic approaches are needed beyond conventional therapies (chemotherapy, surgery and radiation) such as targeted therapies.
Areas covered: Transcriptomic and genomic analyses in ES have revealed alterations in genes that control signalling pathways involved in many other cancer types. To set up more specific approaches, it is reasonable to think that the particular microenvironment of these bone tumours is essential for their initiation and progression, including in ES. To support this hypothesis, preclinical studies using drugs targeting bone cells (bisphosphonate zoledronate, anti-receptor activator of NF-ÎșB ligand strategies) showed promising results in animal models. This review will discuss the new targeted therapeutic options in ES, focusing more particularly on the ones modulating the bone microenvironment.
Expert opinion: Targeting the microenvironment represents a new option for patients with ES. The proof-of-concept has been demonstrated in preclinical studies using relevant animal models, especially for zoledronate, which induced a strong inhibition of tumour progression in an orthotopic bone model
Torsional stability of interference screws derived from bovine bone - a biomechanical study
Introduction: It has been proposed that individual genetic variation contributes to the course of severe infections and sepsis. Recent studies of single nucleotide polymorphisms (SNPs) within the endotoxin receptor and its signaling system showed an association with the risk of disease development. This study aims to examine the response associated with genetic variations of TLR4, the receptor for bacterial LPS, and a central intracellular signal transducer (TIRAP/Mal) on cytokine release and for susceptibility and course of severe hospital acquired infections in distinct patient populations. Methods: Three intensive care units in tertiary care university hospitals in Greece and Germany participated. 375 and 415 postoperative patients and 159 patients with ventilator associated pneumonia (VAP) were included. TLR4 and TIRAP/Mal polymorphisms in 375 general surgical patients were associated with risk of infection, clinical course and outcome. In two prospective studies, 415 patients following cardiac surgery and 159 patients with newly diagnosed VAP predominantly caused by Gram-negative bacteria were studied for cytokine levels in-vivo and after ex-vivo monocyte stimulation and clinical course. Results: Patients simultaneously carrying polymorphisms in TIRAP/Mal and TLR4 and patients homozygous for the TIRAP/Mal SNP had a significantly higher risk of severe infections after surgery (odds ratio (OR) 5.5; confidence interval (CI): 1.34 - 22.64; P = 0.02 and OR: 7.3; CI: 1.89 - 28.50; P < 0.01 respectively). Additionally we found significantly lower circulating cytokine levels in double-mutant individuals with ventilator associated pneumonia and reduced cytokine production in an ex-vivo monocyte stimulation assay, but this difference was not apparent in TIRAP/Mal-homozygous patients. In cardiac surgery patients without infection, the cytokine release profiles were not changed when comparing different genotypes. Conclusions: Carriers of mutations in sequential components of the TLR signaling system may have an increased risk for severe infections. Patients with this genotype showed a decrease in cytokine release when infected which was not apparent in patients with sterile inflammation following cardiac surgery
Aging and health among migrants in a European perspective
Kristiansen M, Razum O, Tezcan-GĂŒntekin H, Krasnik A. Aging and health among migrants in a European perspective. Public Health Reviews. 2016;37(1): 20
Genome-wide association analysis reveals QTL and candidate mutations involved in white spotting in cattle
International audienceAbstractBackgroundWhite spotting of the coat is a characteristic trait of various domestic species including cattle and other mammals. It is a hallmark of HolsteinâFriesian cattle, and several previous studies have detected genetic loci with major effects for white spotting in animals with HolsteinâFriesian ancestry. Here, our aim was to better understand the underlying genetic and molecular mechanisms of white spotting, by conducting the largest mapping study for this trait in cattle, to date.ResultsUsing imputed whole-genome sequence data, we conducted a genome-wide association analysis in 2973 mixed-breed cows and bulls. Highly significant quantitative trait loci (QTL) were found on chromosomes 6 and 22, highlighting the well-established coat color genes KIT and MITF as likely responsible for these effects. These results are in broad agreement with previous studies, although we also report a third significant QTL on chromosome 2 that appears to be novel. This signal maps immediately adjacent to the PAX3 gene, which encodes a known transcription factor that controls MITF expression and is the causal locus for white spotting in horses. More detailed examination of these loci revealed a candidate causal mutation in PAX3 (p.Thr424Met), and another candidate mutation (rs209784468) within a conserved element in intron 2 of MITF transcripts expressed in the skin. These analyses also revealed a mechanistic ambiguity at the chromosome 6 locus, where highly dispersed association signals suggested multiple or multiallelic QTL involving KIT and/or other genes in this region.ConclusionsOur findings extend those of previous studies that reported KIT as a likely causal gene for white spotting, and report novel associations between candidate causal mutations in both the MITF and PAX3 genes. The sizes of the effects of these QTL are substantial, and could be used to select animals with darker, or conversely whiter, coats depending on the desired characteristics
Molecular alterations as target for therapy in metastatic osteosarcoma: a review of literature
Treating metastatic osteosarcoma (OS) remains a challenge in oncology. Current treatment strategies target the primary tumour rather than metastases and have a limited efficacy in the treatment of metastatic disease. Metastatic cells have specific features that render them less sensitive to therapy and targeting these features might enhance the efficacy of current treatment. A detailed study of the biological characteristics and behaviour of metastatic OS cells may provide a rational basis for innovative treatment strategies. The aim of this review is to give an overview of the biological changes in metastatic OS cells and the preclinical and clinical efforts targeting the different steps in OS metastases and how these contribute to designing a metastasis directed treatment for OS
New materials and devices for preventing catheter-related infections
Catheters are the leading source of bloodstream infections for patients in the intensive care unit (ICU). Comprehensive unit-based programs have proven to be effective in decreasing catheter-related bloodstream infections (CR-BSIs). ICU rates of CR-BSI higher than 2 per 1,000 catheter-days are no longer acceptable. The locally adapted list of preventive measures should include skin antisepsis with an alcoholic preparation, maximal barrier precautions, a strict catheter maintenance policy, and removal of unnecessary catheters. The development of new technologies capable of further decreasing the now low CR-BSI rate is a major challenge. Recently, new materials that decrease the risk of skin-to-vein bacterial migration, such as new antiseptic dressings, were extensively tested. Antimicrobial-coated catheters can prevent CR-BSI but have a theoretical risk of selecting resistant bacteria. An antimicrobial or antiseptic lock may prevent bacterial migration from the hub to the bloodstream. This review discusses the available knowledge about these new technologies
Aerosol Therapy for the Treatment of Osteosarcoma Lung Metastases: Targeting the Fas/FasL Pathway and Rationale for the Use of Gemcitabine
Lung metastases are the main cause of death in patients with osteosarcoma (OS). Salvage chemotherapy has been largely unsuccessful in improving the long-term survival of these patients. Understanding the mechanisms that play a role in the metastatic process may identify new therapeutic strategies. We have demonstrated that the cell surface Fas expression, the Fas/FasL signaling pathway, and the constitutive expression of FasL in the lung microenvironment play a critical role in the metastatic potential of OS cells. Here we review the status of Fas expression in two sets of OS cells, human SAOS and LM7 and murine K7 and K7M2, which differ in their ability to metastasize to the lungs. We demonstrated that Fas expression inversely correlated with metastatic potential. Evaluation of Fas expression in a set of lung metastases from patients demonstrated low or no Fas expression consistent with our hypothesis that Fas+ osteosarcoma cells cannot form metastases. The absence of FasL in the lung allows Fas+ osteosarcoma cells to form metastases indicating that the microenvironment is an important contributor to the metastatic potential of osteosarcoma cells. Disruption of the signal transduction pathway using Fas-associated death domain dominant negative (FDN) also allowed Fas+ cells to form lung metastases. Aerosol Gemcitabine (GCB) upregulated Fas expression and induced tumor regression in wild-type Balb/c mice but not Fas L-deficient mice. In conclusion, Fas constitutes an early defense mechanism that allows Fas+ tumor cells to undergo apoptosis when in contact with constitutive FasL in the lung. Fasâ cells or cells with a corrupted Fas pathway evade this defense mechanism and form lung metastases. The aerosol delivery of chemotherapeutic agents that upregulate Fas expression may benefit patients with established pulmonary metastases
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