21,039 research outputs found
Performance characteristics of eight estradiol immunoassays
Journal ArticleMeasurement of estradiol is useful in assisted reproduction, evaluation of infertility, menopause, and male feminization. The analytic performance of 8 estradiol immunoassays was evaluated. The imprecision and accuracy of the Access, ADVIA Centaur, ARCHITECT i2000, AutoDELFIA, Elecsys 2010, IMMULITE 2000, and Vitros ECi estradiol assays (see text for proprietary information) were evaluated by using an isotope dilution-gas chromatography-mass spectrometry (ID-GC-MS) reference method. The coefficient of variation (CV) ranged from 6.9% on the Elecsys 2010 to 42.6% on the ADVIA Centaur at an estradiol concentration of 18 pg/mL (66 pmol/L), with the ARCHITECT i2000 assay in development and the Vitros ECi having a CV below 10% at this estradiol concentration. Agreement between the automated assays and ID-GC-MS was variable, with slopes ranging from 0.87 to 1.20. The Access, ARCHITECT i2000 in development, and the IMMULITE 2000 were the most accurate, with slopes of 0.99, 0.98, and 1.03, respectively. These findings indicate that the ARCHITECT i2000 estradiol assay in development had the best precision and accuracy of the assays evaluated for measurement of serum estradiol concentrations
Tyrosine Nitration of Voltage-dependent Anion Channels in Cardiac Ischemia-reperfusion: Reduction by Peroxynitrite Scavenging
Excess superoxide (O2−) and nitric oxide (NO) forms peroxynitrite (ONOO−) during cardiac ischemia reperfusion (IR) injury, which in turn induces protein tyrosine nitration (tyr-N). Mitochondria are both a source of and target for ONOO−. Our aim was to identify specific mitochondrial proteins that display enhanced tyr-N after cardiac IR injury, and to explore whether inhibiting O2−/ONOO− during IR decreases mitochondrial protein tyr-N and consequently improves cardiac function. We show here that IR increased tyr-N of 35 and 15 kDa mitochondrial proteins using Western blot analysis with 3-nitrotyrosine antibody. Immunoprecipitation (IP) followed by LC–MS/MS identified 13 protein candidates for tyr-N. IP and Western blot identified and confirmed that the 35 kDa tyr-N protein is the voltage-dependent anion channel (VDAC). Tyr-N of native cardiac VDAC with IR was verified on recombinant (r) VDAC with exogenous ONOO−. We also found that ONOO− directly enhanced rVDAC channel activity, and rVDAC tyr-N induced by ONOO− formed oligomers. Resveratrol (RES), a scavenger of O2−/ONOO−, reduced the tyr-N levels of both native and recombinant VDAC, while L-NAME, which inhibits NO generation, only reduced tyr-N levels of native VDAC. O2− and ONOO− levels were reduced in perfused hearts during IR by RES and L-NAME and this was accompanied by improved cardiac function. These results identify tyr-N of VDAC and show that reducing ONOO− during cardiac IR injury can attenuate tyr-N of VDAC and improve cardiac function
Extranodal NK/T-cell lymphoma presenting with primary cardiac involvement
Primary cardiac lymphoma is extremely uncommon. We report a case of a 54 year old Caucasian male with a history of non-small cell lung cancer treated by surgical resection who presented with chest pain and dyspnea on exertion. Computerized tomography (CT) imaging confirmed a 7.8×3.8 cm right atrial soft tissue mass infiltrating the lateral wall of the right atrium, and a 5 cm pericardiophrenic mass. Echocardiography confirmed a moderate pericardial effusion without tamponade physiology. Percutaneous biopsy of the pericardiophrenic mass revealed pathologic features diagnostic of NK/T-cell lymphoma. He received CHOP chemotherapy with some improvement in symptoms, but experienced radiographic progression after 2 cycles. He received palliative involved field radiotherapy but developed new sites of progressive disease within the abdomen and died shortly after completing radiotherapy. NK/T-cell lymphomas are aggressive tumors that may present with unusual extranodal disease sites. Prompt diagnosis with consideration for referral to a specialty center with experience in treatment of these rare tumors may offer the greatest potential for improving treatment outcomes
The Meaning of Memory Safety
We give a rigorous characterization of what it means for a programming
language to be memory safe, capturing the intuition that memory safety supports
local reasoning about state. We formalize this principle in two ways. First, we
show how a small memory-safe language validates a noninterference property: a
program can neither affect nor be affected by unreachable parts of the state.
Second, we extend separation logic, a proof system for heap-manipulating
programs, with a memory-safe variant of its frame rule. The new rule is
stronger because it applies even when parts of the program are buggy or
malicious, but also weaker because it demands a stricter form of separation
between parts of the program state. We also consider a number of pragmatically
motivated variations on memory safety and the reasoning principles they
support. As an application of our characterization, we evaluate the security of
a previously proposed dynamic monitor for memory safety of heap-allocated data.Comment: POST'18 final versio
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Liquid biopsy genotyping in lung cancer: ready for clinical utility?
Liquid biopsy is a blood test that detects evidence of cancer cells or tumor DNA in the circulation. Despite complicated collection methods and the requirement for technique-dependent platforms, it has generated substantial interest due, in part, to its potential to detect driver oncogenes such as epidermal growth factor receptor (EGFR) mutants in lung cancer. This technology is advancing rapidly and is being incorporated into numerous EGFR tyrosine kinase inhibitor (EGFR-TKI) development programs. It appears ready for integration into clinical care. Recent studies have demonstrated that biological fluids such as saliva and urine can also be used for detecting EGFR mutant DNA through application other user-friendly techniques. This review focuses on the clinical application of liquid biopsies to lung cancer genotyping, including EGFR and other targets of genotype-directed therapy and compares multiple platforms used for liquid biopsy
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