Lateral flow assay modified with time-delay wax barriers as a sensitivity and signal enhancement strategy
BIOSENSORS & BIOELECTRONICS
Authors: Sena-Torralba, Amadeo; Duy Ba Ngo; Parolo, Claudio; Hu, Liming; Alvarez-Diduk, Ruslan; Francisco Bergua, Jose; Rosati, Giulio; Surareungchai, Werasak; Merkoci, Arben
Abstract
The ease of use, low cost and quick operation of lateral flow assays (LFA) have made them some of the most common point of care biosensors in a variety of fields. However, their generally low sensitivity has limited their use for more challenging applications, where the detection of low analytic concentrations is required. Here we propose the use of soluble wax barriers to selectively and temporarily accumulate the target and label nanoparticles on top of the test line (TL). This extended internal incubation step promotes the formation of the immune-complex, generating a 51.7-fold sensitivity enhancement, considering the limit of quantification, and up to 96% signal enhancement compared to the conventional LFA for Human IgG (H-IgG) detection.
Parsonage-Turner syndrome associated with hepatitis E infection in immunocompetent patients
VIRUS RESEARCH
Authors: Mendoza-Lopez, Claudia; Lopez-Lopez, Pedro; Atienza-Ayala, Saida; Rivero-Juarez, Antonio; Benito, Rafael
Abstract
Introduction The hepatitis E virus (HEV) is the leading cause of acute hepatitis around the world. In recent years, knowledge has increased concerning extrahepatic manifestations caused by HEV, including neurological manifestations such as Parsonage-Turner syndrome (PTS). PTS is characterized by severe shoulder or arm pain and patchy paresis with muscle weakness. The aim of the present study was to assess the association between HEV and PTS. Materials and Methods We reported two cases of PTS associated with HEV, which were diagnosed in a short period of time in the same village. PTS was diagnosed by physical examination and electrophysiological studies, and serology testing for IgM, low-avidity IgG, and RNA of HEV established the diagnosis of acute HEV infection. Results A 44-year-old man who presented cervicobrachial pain accompanied by paresthesia, dyspnea, and isolated derangement of liver enzymes and 57-year-old women with cervical pain radiated to upper limbs, paresthesia, and liver cytolysis, although, this patient was initially diagnosed as having drug-induced hepatitis. Finally, the diagnosis was Parsonage- Turner syndrome associated with hepatitis e virus. In both patients, symptoms were bilateral and they required hospital admission. Both consumed vegetables are grown in a local patch and the phylogenetic analysis showed genotype 3f. Then, we reviewed the literature on PTS and HEV and we found 62 previously described cases that were more likely to be men (86.20 %) with more frequent bilateral symptoms (85.71 %). Genotype 3 is the most commonly associated. Three of those cases were diagnosed in Spain. Conclusions According to our findings, HEV should be considered in patients with neuralgic amyotrophy, including those with the absence of liver cytolysis.