Next-generation sequencing (NGS) studies are becoming routinely used for the detection of novel and clinically actionable DNA variants at a pangenomic scale. Such analyses are now used in the clinical practice to enable precision medicine. Formalin-fixed paraffin-embedded (FFPE) tissues are still one of the most abundant source of cancer clinical specimen, unfortunately this method of preparation is known to degrade DNA and therefore compromise subsequent analysis.
View Article and Find Full Text PDFGroup functioning may limit interdisciplinarity. Four scenarios of health professionals' meetings are described. A) If priority is timing, the group isn't interdisciplinary any longer; decisions are endorsed without questioning or criticism.
View Article and Find Full Text PDFJ Chromatogr B Analyt Technol Biomed Life Sci
May 2010
An analytical method was developed for the simultaneous speciation of selenomethionine (SeMet) and 2-hydroxy-4-methylselenobutanoic acid (NutraSelen), a new SeMet precursor. The compounds could be baseline resolved by ion-pairing reversed-phase HPLC using ICP MS detection. Detection limits of 1 ng mL(-1) (Se content) could be reached.
View Article and Find Full Text PDFAn approach for "resisting patients" to treatments and weight loss programme is proposed. Patient's resistance is a sign of vitality, a source of information for the health care provider and an invitation to question the nature of therapeutic relationship. Resistance can constitute a "block road" which the health care provider may not be able to avoid unless initiating a process of changes based on reciprocal responsibilities and implications.
View Article and Find Full Text PDFWe and others have previously reported in an in vivo rat colon cancer cell model that cell death precedes and is necessary for the development of a specific antitumoral immune response. To sensitize colon cancer cells to death, we depleted cytochrome c by stable transfection with an antisense construct. Cytochrome c depletion sensitizes human and rat colon cancer cells to a nonapoptotic, nonautophagic death induced by various stimuli.
View Article and Find Full Text PDFDespite the wide range of available therapies, human colon cancers remain difficult to cure. Evidence for efficient antitumoral immune responses to be raised is now widely accepted, and numerous strategies exploiting the host immune system have been developed. A treatment based on the lipid-A derivative OM-174 has been developed in our laboratory.
View Article and Find Full Text PDFIn some carcinomas such as digestive tract carcinomas, bone marrow infiltration by tumor cells is a frequent event but usually remains a micrometastatic disease and rarely induces overt bone lesions. The mechanisms responsible for the control of these metastases in the bone marrow remain poorly known. We show that freshly isolated bone marrow cells from human, murine and rat origin rapidly kill a wide range of syngeneic or xenogeneic carcinoma cell lines in culture.
View Article and Find Full Text PDFREGb cell line, a highly immunogenic tumor cell variant isolated from a rat colon cancer, yields regressive tumors when injected into syngeneic hosts. We previously demonstrated that REGb tumor immunogenicity was related to the capacity of releasing dead cells in vivo. Also, in vitro, REGb cell monolayers release dead cells, especially when cultured in serum-free medium.
View Article and Find Full Text PDFImmunization can prevent tumor growth, but the effector cells directly responsible for tumor cell killing in immunized hosts remain undetermined. The present study compares tumor grafts that progress in naive syngeneic rats with the same grafts that completely regress in hosts preimmunized with an immunogenic cell variant. The progressive tumors contain only a few macrophages that remain at the periphery of the tumor without direct contact with the cancer cells.
View Article and Find Full Text PDFPlatelet transfusion is widely used to prevent bleeding in patients with severe thrombocytopenia. The maximal storage duration of platelet concentrates is usually 5 days, due to the platelet storage lesion that impairs their functions when stored for longer times. Some of the morphological and biochemical changes that characterize this storage lesion are reminiscent of cell death by apoptosis.
View Article and Find Full Text PDFA defective function of the antigen-presenting cells may represent one of the ways used by cancer cells to escape the immune response. We have previously shown that human and rat colon carcinomas were infiltrated by dendritic cells that did not express the B7 co-stimulatory molecules required for inducing an efficient T-cell response. Flt3 ligand is a cloned hematopoietic growth factor that markedly augments the number of functional dendritic and NK cells in lymphoid and non-lymphoid tissues and exerts anti-tumor activity in various experimental models.
View Article and Find Full Text PDFEstablishment of an immune response against cancer may depend on the capacity of dendritic cells to transfer tumor Ags into T cell-rich areas. To check this possibility, we used a colon cancer cell variant that yields tumors undergoing complete T cell-dependent rejection when injected into syngeneic rats. We previously demonstrated that immunogenicity of these tumors depended on the early apoptosis of a part of these tumor cells.
View Article and Find Full Text PDFThe REG and PRO cell clones were obtained from a colon adenocarcinoma induced in a BDIX rat by 1,2-dimethylhydrazine. When injected s.c.
View Article and Find Full Text PDFTumor cell clones from a rat colon carcinoma differ in their tumorigenicity and immunogenicity. The PRO clones give rise to progressive tumors, whereas the REG clones yield tumors that regress in a few weeks through a specific immune response. REG cells were more sensitive than PRO cells to apoptosis triggered by serum withdrawal in vitro.
View Article and Find Full Text PDFFree Radic Biol Med
August 1998
Based on the assumption that glutathione peroxidase (GPx) activity might be limiting in preventing peroxide-induced impairment of endothelial regulatory functions, we studied the effect of a series of new selenium-containing GPx mimics on endothelial cells exposed to an inflammatory stress. The two compounds that have the highest GPx activity, BXT-51072 and BXT-51077, were shown to be the most efficient inhibitors of leukocyte recruitment by human umbilical vein endothelial cells (HUVEC), upon incubation with neutrophils (10-fold excess over HUVEC) and with 1 ng/ml TNF-alpha for 1 or 3.5 h.
View Article and Find Full Text PDFIntercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) are respectively involved in the endothelial recruitment of neutrophils, and in that of lymphocytes or tumor cells, in response to specific signals. We have used the glutathione peroxidase (GPx) mimic BXT-51072 to assess the possibility that endogenous hydroperoxides play a role in the tumor necrosis factor-alpha (TNFalpha)-induced expression of ICAM-1 and VCAM-1 by monolayers of human endothelial cells. The GPx mimic BXT-51072 strongly inhibits the TNFalpha-induced and cycloheximide-sensitive expression of ICAM-1 and VCAM-1.
View Article and Find Full Text PDFColon cancer cells express potentially immunogenic proteins but are not rejected by the immune system. To induce an effective immune response, antigenic peptides have to be presented to T lymphocytes by professional antigen-presenting cells in association with HLA class II molecules. Antigen-presenting cells also have to express B7 family molecules, B7-1 and B7-2, which deliver the costimulatory signals that are required to prevent T cell anergy.
View Article and Find Full Text PDFAlternative splicing of primary fibronectin (FN) mRNA results in the synthesis of different isoforms. ED-A+ and ED-B+ FN isoforms are absent from plasma FN and are representative of cellular FN. Their expression was studied in human and rat normal colon, in human colorectal carcinomas, and in transplanted tumors derived from a chemically-induced rat colon cancer.
View Article and Find Full Text PDFNew selenium containing compounds which act as mimics of glutathione peroxidase (GPx) protect vascular endothelial cells (HUVEC) from the toxicity of 140 microM hydrogen peroxide. In the absence of GPx mimic, hydrogen peroxide destroys the tightness of the cellular monolayer and transforms the actin network into compact stress fibers. The pre-treatment of the cells by 4 microM of the lead-compound BXT-51072 for 1 hours inhibits the morphological modifications induced by hydrogen peroxide.
View Article and Find Full Text PDFNew selenium-containing compounds behave as GPx mimics and protect endothelial cells (HUVEC) from damage upon exposure to 55 microM linoleic acid hydroperoxide or to 200 microM hydrogen peroxide. The simultaneous presence of the GPx mimic and the hydroperoxyde is not necessary, since a pre-treatment of endothelial monolayers with 1 to 10 microM of such compounds, preserves their morphology, their cell density and their longer-term viability. The compounds which are most efficient in this model of oxidative stress also protect endothelial monolayers which have been incubated with an excess (10:1) of polymorphonuclear neutrophils (PMN) and with 1 ng/ml of TNF-alpha, if such monolayers are pre- and co-treated (10 microM).
View Article and Find Full Text PDFA new spectrophotometric assay of superoxide dismutase (SOD) activity is described. The assay is based on the SOD-mediated increase in the rate of autoxidation of 5,6,6a,11b-tetrahydro-3,9,10-trihydroxybenzo[c]fluorene (BXT-01050) in aqueous alkaline solution. This autoxidation yields a chromophore with a maximal absorbance wavelength of 525 nm.
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