3,134 publications from this institution
Abstract Visceral leishmaniasis ( VL ) was known as an opportunistic infection associated with immunosuppression, particularly related to human immunodeficiency virus infection and rarely to solid organ transplant recipients. We report a case of VL , 6 months after liver transplantation, in a patient who presented with febrile pancytopenia. The diagnosis was made by demonstration of amastigotes in smears from bone marrow. VL is a very rare infection in patients who undergo liver transplantation and, to our knowledge, this is the first case diagnosed in Portugal.
Establishing a definitive diagnosis of pneumonia using conventional tests is difficult and expensive. Lateral flow immunoassays (LFIAs) are an advantageous point of care (POC) test option, but they have some limitations in terms of detection and quantification. In this work we have developed a lateral flow immunoassay for the ultrasensitive detection of penumolysin employing plasmonic Surface-Enhanced Resonance Raman Scattering (SERRS) tag as labelled probe. The combination of Au@Ag core–shell nanoparticles as plasmonic platform and Rhodamine B Isothiocyanate as Raman reporter has allowed us to fabricate a SERRS tag with high efficiency and reliability. The limit of detection of the SERRS-based LFIA was 1 pg mL−1. This could be a strong foundation for a pneumonia diagnosis test based on pneumolysin detection.
Treatment of sterile body fluids (SBFs) infections is delayed by conventional methods that require up to 72 h to detect pathogens. Here, we present a CRISPR-associated protein 12a (Cas12a)-programmed nanocatalyst release (CNR) method for culture-free diagnostics. To enhance both sensitivity and coverage, three starter DNA (sDNA)-complementary DNA (cDNA) probe pairs were designed for conserved regions and additional three pairs for variable regions of bacterial 16S or fungal 18S rRNA. Upon target recognition, cDNA undergoes strand displacement, releasing sDNA to activate Cas12a. The activated Cas12a cleaves copper oxide nanoparticle (CuONPs)-loaded magnetic probes, releasing tandem CuONPs. Upon acid dissolution, each CuONP generates Cu<sup>2+</sup> ions that catalyze the oxidation of 3,3',5,5'-tetramethylbenzidine (TMB), producing a visible colorimetric signal. This quadruple signal amplification strategy integrates high-copy rRNA targets, multi-cDNA recognition, Cas12a-mediated continuous release of tandem CuONPs, and Cu<sup>2+</sup>-driven chromogenic amplification. This nucleic acid amplification-free assay detects pathogens at 0.69 CFU mL<sup>-1</sup> in original SBFs samples (after 10-fold centrifugation) within 70 min. In 64 clinical samples, it achieved 100% sensitivity and 100% specificity versus culture. Notably, one culture-negative but clinically confirmed case was correctly identified. Overall, the CNR method offers a rapid, ultrasensitive, and accessible diagnostic solution for resource-limited settings.
jModelTest is a new program for the statistical selection of models of nucleotide substitution based on "Phyml" (Guindon and Gascuel 2003. A simple, fast, and accurate algorithm to estimate large phylogenies by maximum likelihood. Syst Biol. 52:696-704.). It implements 5 different selection strategies, including "hierarchical and dynamical likelihood ratio tests," the "Akaike information criterion," the "Bayesian information criterion," and a "decision-theoretic performance-based" approach. This program also calculates the relative importance and model-averaged estimates of substitution parameters, including a model-averaged estimate of the phylogeny. jModelTest is written in Java and runs under Mac OSX, Windows, and Unix systems with a Java Runtime Environment installed. The program, including documentation, can be freely downloaded from the software section at http://darwin.uvigo.es.
Diabetes is characterized by an elevated level of glucose in the blood. This glucose can form covalent adducts with plasma proteins through a non-enzymatic process known as glycation. It has been suggested that the increasing glycation can influence the ability of plasma proteins to bind to small molecules. Herein, the difference between healthy human plasma proteins (HPP) and type II diabetes plasma proteins (TPP) in binding small molecules was investigated. TPP showed about 1-10 times lower affinities for polyphenols than HPP. The values of lg K(a)(HPP) are positive proportional to the values of lg K(a)(TPP) with excellent linear relationship. The glycation of HPP decreased the affinities for HPP by about 1.17 to 16.6 times. The difference between HPP-polyphenol interaction and TPP-polyphenol interaction was bigger for the more lipophilic polyphenols. The affinities for TPP or HPP slightly decreased with increasing hydrogen bond donor numbers of polyphenols and hardly changed with hydrogen bond acceptor numbers.