Validation of an Immunoassay for Detection and Quantitation of a Genetically Modified Soybean in Food and Food Fractions Using Reference Materials: Interlaboratory Study

An immunoassay for detection of a specific genetically modified soybean (Roundup-Ready®) was validated on dried soybean powder in an interlaboratory study. Different percentages of genetically modified soybeans in nonmodified soybean matrix were evaluated in a blind study. Thirty-eight laboratories from 13 countries participated. The immunoassay was evaluated for 2 endpoints: (1) To give a semiquantitative result, i.e., determination of a given sample above or below a given threshold, or (2) to compute a quantitative result, i.e., percentage of genetically modified soybeans in the sample. Semiquantitative results showed that a given sample which contained <2% genetically modified soybeans was identified as below 2% with a 99% confidence level. Quantitative use of the assay resulted in a repeatability (r) and reproducibility (R) that were computed to be RSDr = 7% and RSDR = 10%, respectively, for a sample containing 2% genetically modified soybeans. Application of this method depends on availability of appropriate reference materials for a specific food matrix. Only matrix-matched reference materials can be used for analysis of food or food fractions.

Neurohormonal modulation: The new paradigm of pharmacological treatment of heart failure

The current paradigm of medical therapy for heart failure with reduced ejection fraction (HFrEF) is triple neurohormonal blockade with an angiotensin-converting enzyme inhibitor (ACEI), a beta-blocker (BB) and a mineralocorticoid receptor antagonist (MRA). However, three-year mortality remains over 30%. Stimulation of counter-regulatory systems in addition to neurohormonal blockade constitutes a new paradigm, termed neurohormonal modulation. Sacubitril/valsartan is the first element of this new strategy. PARADIGM-HF was the largest randomized clinical trial conducted in HFrEF. It included 8442 patients and compared the efficacy and safety of sacubitril/valsartan versus enalapril. The primary endpoint was the composite of cardiovascular mortality and hospitalization due to HF, which occurred in 914 (21.8%) patients receiving sacubitril/valsartan and in 1117 (26.5%) patients receiving enalapril (HR 0.8, 95% CI 0.73-0.87, p=0.0000002; NNT 21). Sacubitril/valsartan reduced both primary endpoint components, as well as sudden cardiac death, death due to worsening HF, and death from all causes. Patients on sacubitril/valsartan reported less frequent deterioration of HF and of quality of life, and discontinued study medication less frequently because of an adverse event. PARADIGM-HF demonstrated the superiority of sacubitril/valsartan over enalapril, with a 20% greater impact on cardiovascular mortality compared to ACEIs. Accordingly, in 2016, the European (ESC) and American (ACC/AHA/HFSA) cardiology societies simultaneously issued a class I recommendation for the replacement of ACEIs by sacubitril/valsartan in patients resembling PARADIGM-HF trial participants.

Characterization of a new genotype of Betapapillomavirus HPV 17 through L1, E7, E7 and LCR sequences

Human papillomavirus (HPV) exhibits epithelial and mucosal tropism. HPV type 17 belongs to the Betapapillomavirus genus and molecular cloning experiments have identified two subtypes (17a and 17b) isolated from epidermodysplasia verruciformis (EV). HPV subtypes are characterized by dissimilarities from 2 to 10% at the nucleotide level from their referenced HPV. The aim of this study was to characterize the L1, E6, E7 and LCR sequences from an isolate, which was recovered from the oral mucosa of an asymptomatic 63 year-old woman. The whole late gene 1 (L1) was amplified using several sets of primers. The complete early genes 6 and 7 (E6, E7) and the long control region (LCR) were amplified using specific primers. Potential binding sites for transcriptional factors within the LCR were also investigated. Within these sets, the DNA sequence was altered at 91 positions (68 in L1, 13 in E6, 8 in E7, and 2 in LCR sequences). L1 analysis showed high dissimilarity compared with the HPV 17 prototype, reaching 4% of nucleotide substitutions and leading to a probable third 17 subtype. The E6 oncoprotein presented the highest modification among the sequences studied, with four amino acid changes in comparison with the prototype isolate. One amino acid was modified at a position 62 (S-T), a zinc-binding domain (CxxC(C)29 CxxC). Our findings provide data on genetic variations seen in this genotype, reaching to dichotomic branching and pointing to an evolutionary process.