No abstract

We evaluated the performance characteristics of three real-time reverse transcription-PCR test systems for detection and quantification of hepatitis C virus (HCV) and performed a direct comparison of the systems on the same clinical specimens. Commercial HCV panels (genotype 1b) were used to evaluate linear range, sensitivity, and precision. The Roche COBAS TaqMan HCV test for research use only (RUO) with samples processed on the MagNA Pure LC instrument (Roche RUO-MPLC) and Abbott analyte-specific reagents (ASR) with QIAGEN sample processing (Abbott ASR-Q) showed a sensitivity of 1.0 log 10 IU/ml with a linear dynamic range of 1.0 to 7.0 log 10 IU/ml. The Roche ASR in combination with the High Pure system (Roche ASR-HP) showed a sensitivity of 1.4 log 10 IU/ml with a linear dynamic range of 2.0 to 7.0 log 10 IU/ml. All of the systems showed acceptable reproducibility, the Abbott ASR-Q being the most reproducible of the three systems. Seventy Hepatitis C virus (HCV) is still a major health care problem worldwide, including the United States. It is estimated that more than 170 million people worldwide are infected with HCV. HCV is one of the leading indications for liver transplantation in the United States (11). Prospective studies have shown that 60 to 85% of HCV-infected individuals develop chronic disease. Current recommendations for treatment are combination therapy with pegylated interferon and ribavirin (18). Treatment guidelines and monitoring the response to therapy rely heavily on viral load testing and genotype information. Genotyping should be performed before starting treatment to determine duration of treatment and dosage of ribavarin and also to provide prognostic information. The recommended durations of combination therapy are 24 weeks for genotypes 2 and 3 and 48 weeks for genotypes 1, 4, and 6 (18). Responses to treatment vary greatly, from approximately 40% for those infected with HCV genotypes 1 and 4 to about 80% for those infected with HCV genotypes 2 and 3.Quantitative testing should be performed by methods with a wide enough dynamic range for accurate assessment of both pretreatment viral loads as well as an early virologic response, which is defined as a fall in the HCV RNA levels by at least 2 log 10 units or to an undetectable level at week 12 of treatment. Currently, the best indicator of effective treatment is a sustained virologic response (SVR), defined by the absence of detectable HCV RNA in the serum when determined 6 months after the end of treatment. A sensitive method with a low limit of detection of 50 IU/ml or less should be used to assess SVR (18).A variety of assays are commercially available to detect and quantify HCV RNA. They are based on three specific methodologies: PCR, transcription-mediated amplification (TMA) and the branched-DNA technique (4,5,15,20). The most commonly used PCR-based assay for HCV quantification is the COBAS Amplicor HCV Monitor v2.0, with a lower limit of quantification of 600 IU/ml, which is inadequate to define an end-of-treatment response or ...

No abstract

UV filters are potentially harmful to marine organisms. Given their worldwide dissemination and the scarcity of studies on marine fish, we evaluated the toxicity of an organic (oxybenzone) and an inorganic (titanium dioxide nanoparticles) UV filter, individually and in a binary mixture, in the turbot (Scophthalmus maximus). Fish were intraperitoneally injected and a multi-level assessment was carried out 3 and 7 days later. Oxybenzone and titanium dioxide nanoparticles induced mild effects on turbot, both isolated and in mixture. Neither oxidative stress (intestine, liver and kidney) nor neurotoxicity (brain) was found. However, liver metabolic function was altered after 7 days, suggesting the impairment of the aerobic metabolism. An increased motility rate in oxybenzone treatment was the only behavioural alteration (day 7). The intestine and liver were preferentially targeted, while kidney and brain were unaffected. Both infra- and supra-additive interactions were perceived, with a toxicodynamic nature, resulting either in favourable or unfavourable toxicological outcomes, which were markedly dependent on the organ, parameter and post-injection time. The combined exposure to the UV filters did not show a consistent increment in toxicity in comparison with the isolated exposures, which is an ecologically relevant finding providing key information towards the formulation of environmentally safe sunscreen products.

Allelic variants at codons 16 and 27 of the ␤ 2 -adrenergic receptor gene (ADRB2) have shown clinical and pharmacological implications in asthma , hypertension , ischemic heart failure , diabetes , obesity, and cystic fibrosis. We have developed a simultaneous genotyping assay for the c.46A>G and c.79C>G allelic variants using hybridization probes and melting curve analysis. The assay was optimized on a panel of 30 DNA samples of known ADRB2 genotype as determined by sequencing with 100% concordance between the two techniques. Melting temperature (Tm) ranges for the different genotypes were obtained using data from three independent experiments. Single peaks for p.Arg16Arg (Tm ‫؍‬ 57.76°C ؎ 0.10°C) and p.Gly16Gly (Tm ‫؍‬ 66.73°C ؎ 0.18°C) and two melting peaks for p.Arg16Gly were obtained. Similarly , single peaks for p.Gln27Gln