Cyanide quantification in post-mortem biological matrices by headspace GC–MS

Cyanide is a powerful chemical asphyxiant found in some forensic cases following voluntary (suicide) or involuntary ingestion (fire, accidental exposure). A quantification method for cyanide that is specifically suited to post-mortem forensic purposes was developed. Determination was performed by headspace gas chromatography coupled to mass spectrometry using a GS-GASPRO column on an HP-6890 gas chromatograph with an HP-5973N mass detector. The biological sample was treated with an internal standard, frozen, glacial acetic acid was added and the sample was then incubated at 60 °C for 15 min. The headspace was sampled with a disposable syringe, and analyzed to quantify hydrogen cyanide. Isotopically labeled cyanide (13C15N) was used as the internal standard to minimize matrix effect and sampling error. The method produced an extended linear dynamic range (0.07–50 μg/mL), and a method detection limit of 0.02 μg/mL. Identical calibration curves were obtained when blood, gastric contents and aqueous solutions were used as the calibration standard matrix. This method was also successful in quantitating cyanide in gastric contents, one of the most variable biological fluids. The method has been validated and is being used for current forensic cases such as fire victims and suicides

Mutations in the Mitochondrial Methionyl-tRNA Synthetase Cause a Neurodegenerative Phenotype in Flies and a Recessive Ataxia (ARSAL) in Humans

The study of Drosophila neurodegenerative mutants combined with genetic and biochemical analyses lead to the identification of multiple complex mutations in 60 patients with a novel form of ataxia/leukoencephalopathy

The R1 subunit of herpes simplex virus ribonucleotide reductase is a good substrate for host cell protein kinases but is not itself a protein kinase

UI - 98104124NRC publication: Ye

Association of Neutrophil-to-Lymphocyte Ratio With Inflammation and Erythropoietin Resistance in Chronic Dialysis Patients

Background: Neutrophil-to-lymphocyte ratio (NLR) was widely studied as a prognostic marker in various medical and surgical specialties, but its significance in nephrology is not yet established. Objective: We evaluated its accuracy as an inflammation biomarker in a dialysis population. Design setting: Single-center retrospective study. Patients: The records of all 550 patients who were treated with hemodialysis (HD) or peritoneal dialysis (PD) from September 2008 to March 2011 were included. Measurements: NLR was calculated from the monthly complete blood count. Methods: Association between NLR and markers of inflammation (C-reactive protein [CRP], serum albumin, and erythropoietin resistance index [ERI]) was measured using Spearman coefficient. Results: In total, 120 patients were eligible for the correlation analyses. We found a positive correlation between NLR and CRP (all patients: r = 0.45, P < .001; HD: r = 0.47, P < .001; PD: r = 0.48, P = .13). NLR and albumin were inversely correlated ( r = −0.51, P < .001). Finally, high NLR was associated with a nonsignificant increased ERI, but we have not demonstrated a direct correlation. Limitations: CRP and albumin are not measured routinely and were ordered for a specific clinical reason leading to an indication bias. Also, no relationship with clinical outcome was established. Conclusions: NLR seems to be a good inflammatory biomarker in dialysis in addition to being easily available. However, controlled studies should be conducted to properly assess and validate NLR levels that would be clinically significant and relevant, as well as its prognostic significance and utility in a clinical setting

A novel inhibitor of the mitochondrial respiratory complex I with uncoupling properties exerts potent antitumor activity

International audienceCancer cells are highly dependent on bioenergetic processes to support their growth and survival. Disruption of metabolic pathways, particularly by targeting the mitochondrial electron transport chain complexes (ETC-I to V) has become an attractive therapeutic strategy. As a result, the search for clinically effective new respiratory chain inhibitors with minimized adverse effects is a major goal. Here, we characterize a new OXPHOS inhibitor compound called MS-L6, which behaves as an inhibitor of ETC-I, combining inhibition of NADH oxidation and uncoupling effect. MS-L6 is effective on both intact and sub-mitochondrial particles, indicating that its efficacy does not depend on its accumulation within the mitochondria. MS-L6 reduces ATP synthesis and induces a metabolic shift with increased glucose consumption and lactate production in cancer cell lines. MS-L6 either dose-dependently inhibits cell proliferation or induces cell death in a variety of cancer cell lines, including B-cell and T-cell lymphomas as well as pediatric sarcoma. Ectopic expression of Saccharomyces cerevisiae NADH dehydrogenase (NDI-1) partially restores the viability of B-lymphoma cells treated with MS-L6, demonstrating that the inhibition of NADH oxidation is functionally linked to its cytotoxic effect. Furthermore, MS-L6 administration induces robust inhibition of lymphoma tumor growth in two murine xenograft models without toxicity. Thus, our data present MS-L6 as an inhibitor of OXPHOS, with a dual mechanism of action on the respiratory chain and with potent antitumor properties in preclinical models, positioning it as the pioneering member of a promising drug class to be evaluated for cancer therapy. MS-L6 exerts dual mitochondrial effects: ETC-I inhibition and uncoupling of OXPHOS. In cancer cells, MS-L6 inhibited ETC-I at least 5 times more than in isolated rat hepatocytes. These mitochondrial effects lead to energy collapse in cancer cells, resulting in proliferation arrest and cell death. In contrast, hepatocytes which completely and rapidly inactivated this molecule, restored their energy status and survived exposure to MS-L6 without apparent toxicity