Clinical validation of SARS-CoV-2 electrochemical immunosensor based on the spike-ACE2 complex.

BACKGROUND AND AIMS: Advances in health, especially in prevention, diagnosis, and treatment, have significantly impacted the way of facing emerging infectious diseases. Yet, events such as the COVID-19 pandemic have shown that there is still a long way to go. Therefore, an urgent need exists for portable and easily deployable point-of-care (POC) detection tools. Biosensors at the POC remain in the laboratory in an analytical characterization step and are not yet mature enough to reach the market massively. In this context, it is necessary to progress in validating these devices to demonstrate their relevance in detecting different disease biomarkers. This work reports on the clinical validation of an electrochemical immunosensor for detecting SARS-CoV-2. METHODS: A monocentric retrospective cohort study was conducted with 150 random nasopharyngeal swabs or tracheal aspiration samples tested by RT-PCR. The immunosensor based on magnetic beads and chronoamperometry detected SARS-CoV-2 through the spike-angiotensin-converting protein (ACE2) immunocomplex. RESULTS: This biosensor demonstrated 96.04 % clinical sensitivity and 87.75 % clinical specificity in detecting SARS-CoV-2 in the samples, highly correlated with the RT-PCR gold standard. CONCLUSIONS: It demonstrates the potential of electrochemical biosensors to be implemented as highly sensitive and easily deployable detection strategies even in remote locations.

Detection of COVID-19-related biomarkers by electrochemical biosensors and potential for diagnosis, prognosis, and prediction of the course of the disease in the context of personalized medicine.

As a more efficient and effective way to address disease diagnosis and intervention, cutting-edge technologies, devices, therapeutic approaches, and practices have emerged within the personalized medicine concept depending on the particular patient's biology and the molecular basis of the disease. Personalized medicine is expected to play a pivotal role in assessing disease risk or predicting response to treatment, understanding a person's health status, and, therefore, health care decision-making. This work discusses electrochemical biosensors for monitoring multiparametric biomarkers at different molecular levels and their potential to elucidate the health status of an individual in a personalized manner. In particular, and as an illustration, we discuss several aspects of the infection produced by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) as a current health care concern worldwide. This includes SARS-CoV-2 structure, mechanism of infection, biomarkers, and electrochemical biosensors most commonly explored for diagnostics, prognostics, and potentially assessing the risk of complications in patients in the context of personalized medicine. Finally, some concluding remarks and perspectives hint at the use of electrochemical biosensors in the frame of other cutting-edge converging/emerging technologies toward the inauguration of a new paradigm of personalized medicine.

In Silico and In Vitro Identification of 1,8-Dihydroxy-4,5-dinitroanthraquinone as a New Antibacterial Agent against Staphylococcus aureus and Enterococcus faecalis.

Increasing rates of bacterial resistance to antibiotics are a growing concern worldwide. The search for potential new antibiotics has included several natural products such as anthraquinones. However, comparatively less attention has been given to anthraquinones that exhibit functional groups that are uncommon in nature. In this work, 114 anthraquinones were evaluated using in silico methods to identify inhibitors of the enzyme phosphopantetheine adenylyltransferase (PPAT) of Staphylococcus aureus, Enterococcus faecalis, and Escherichia coli. Virtual screenings based on molecular docking and the pharmacophore model, molecular dynamics simulations, and free energy calculations pointed to 1,8-dihydroxy-4,5-dinitroanthraquinone (DHDNA) as the most promising inhibitor. In addition, these analyses highlighted the contribution of the nitro group to the affinity of this anthraquinone for the nucleotide-binding site of PPAT. Furthermore, DHDNA was active in vitro towards Gram-positive bacteria with minimum inhibitory concentration (MIC) values of 31.25 µg/mL for S. aureus and 62.5 µg/mL for E. faecalis against both antibiotic-resistant isolates and reference strains but was ineffective against E. coli. Experiments on kill-time kinetics indicated that, at the tested concentrations, DHDNA produced bacteriostatic effects on both Gram-positive bacteria. Overall, our results present DHDNA as a potential PPAT inhibitor, showing antibacterial activity against antibiotic-resistant isolates of S. aureus and E. faecalis, findings that point to nitro groups as key to explaining these results.

Diversity and distribution of macrofungi (Ascomycota and Basidiomycota) in Tolima, a Department of the Colombian Andes: an annotated checklist.

Background: Macrofungi are classified in the phylum Ascomycota and Basidiomycota and they are very important from an ecological and economic point of view. Most studies of fungi in Colombia have been carried out mainly in the Andean Region, especially in the Departments of Antioquia, Valle del Cauca and Cundinamarca. However, other Departments in the Andean Region, like Tolima, located in the Cordillera Central, are well documented for plants (4,797 species) and animals (2,983 species), but very poorly documented in terms of knowledge of fungal diversity. New information: This study provides a compiled and annotated checklist of all known macrofungi in the Department of Tolima, based on published literature and on the identification of new specimens collected from five localities of the Department. All records were updated taxonomically and we include detailed information on the localities in which they are distributed in the Department. The list includes 164 taxa distributed in 15 orders (Agaricales, Polyporales, Russulales, Boletales, Hymenochaetales, Xylariales, Auriculariales, Thelephorales, Cantharellales, Hypocreales, Pezizales, Gloeophyllales, Phallales, Tremellales, Dacrymycetales) and eighteen records in a doubtful taxa section. We present 26 new reports, 19 for Tolima and nine for Colombia. We also provide genetic and phylogenetic evidence of the occurrence of Gloeoporustelephoroides and Podoscyphavenustula in Colombia. This checklist provides the basis for future studies on species diversity and taxonomy in Tolima, by identifying the least studied taxa and ecosystems and conservation priorities.

SARS-CoV-2 electrochemical immunosensor based on the spike-ACE2 complex.

Rapid, straightforward, and massive diagnosis of coronavirus disease 2019 (COVID-19) is one of the more important measures to mitigate the current pandemics. This work reports on an immunosensor to rapidly detect the spike protein from the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The immunosensing device entraps the spike protein linked to angiotensin-converting enzyme host receptor (ACE2) protein in a sandwich between carboxylated magnetic beads functionalized with an anti-spike antibody and an anti-ACE2 antibody, further labeled with streptavidin (poly)horseradish peroxidase (HRP) reporter enzyme. The particles were confined at the surface of screen-printed gold electrodes, whose signal resulting from the interaction of the enzyme with a mediator was recorded in a portable potentiostat. The immunosensor showed a sensitivity of 0.83 µA∗mL/µg and a limit of detection of 22.5 ng/mL of spike protein, with high reproducibility. As a proof-of-concept, it detected commercial spike protein-supplemented buffer solutions, pseudovirions, isolated viral particles and ten nasopharyngeal swab samples from infected patients compared to samples from three healthy individuals paving the way to detect the virus closer to the patient.

Microstructural, microchemical, and mechanical changes associated with the clinical reuse of two nickel-titanium endodontic instruments.

BACKGROUND: Nickel-titanium (NiTi) instruments have represented a great technological development that enabled endodontists conforming irregular-shaped root canals. Notwithstanding, the repeated use of these instruments may lead to the fracture without any prior visible warning signs. This study aimed to evaluate how multiple clinical instrumentation/sterilization cycles of two NiTi mechanized instruments can affect their microstructural, microchemical, and mechanical characteristics. MATERIALS AND METHODS: In this observational descriptive study, a total of 140 NiTi instruments, 70 ProTaper Gold® (PTG) and 70 WaveOne Gold® (WOG) were analyzed. For each brand system, instruments were evaluated in the as-received condition (n = 10) and after one (n = 20), two (n = 20), and three (n = 20) instrumentation/sterilization cycles. Intraoperative instrumentation parameters were recorded for all used instruments. Afterward, the files were examined using scanning electron microscopy and energy-dispersive X-ray microanalysis. All of the instruments were tensile-fatigue tested until rupture in order to calculate the mechanical tensile strength and the maximum elongation percentage for the samples. Statistical analysis was completed using Chi-square, Kruskal-Wallis H-, or Mann-Whitney U-tests with a statistical significance set at P < 0.05. RESULTS: Significant increasing changes in surface topography (P < 0.05, Chi-square test) and chemical composition (P < 0.05, Kruskal-Wallis H-test) in both brand systems through instrumentation/sterilization cycles were detected. In addition, values of mechanical tensile strength and maximum elongation percentage increased significantly through instrumentation/sterilization cycles in the PTG group, whereas only the median values of mechanical tensile strength increased significantly in the WOG group (all P < 0.01, Kruskal-Wallis H-test). CONCLUSION: Although multiple instrumentation/sterilization cycles may render NiTi instruments more flexible and fatigue resistant, the significant changes detected in their surface topography and chemical composition should preclude their repeated clinical use in the routine endodontic practice as prevention for breakage.

Functional Nanocarriers for Delivering Itraconazole Against Fungal Intracellular Infections.

Infectious diseases caused by intracellular microorganisms represent a significant challenge in medical care due to interactions among drugs during coinfections and the development of resistance in microorganisms, limiting existing therapies. This work reports on itraconazole (ITZ) encapsulated into functional polymeric nanoparticles for their targeted and controlled release into macrophages to fight intracellular infections. NPs are based on poly (lactic acid-co-glycolic acid) (PLGA) polymers of different compositions, molecular weights, and lactic acid-to-glycolic acid ratios. They were self-assembled using the high-energy nanoemulsion method and characterized by transmission electron microscopy, Fourier transform infrared spectroscopy (FT-IR), and differential scanning calorimetry. It was studied how the polymer-to-drug ratio, changes in the aqueous phase pH, and type and concentration of surfactant affected nanocarriers' formation, drug-loading capacity, and encapsulation efficiency. Results showed that drug-loading capacity and encapsulation efficiency reached 6.7 and 80%, respectively, by lowering the pH to 5.0 and using a mixture of surfactants. Optimized formulation showed an initial immediate ITZ release, followed by a prolonged release phase that fitted better with a Fickian diffusion kinetic model and high stability at 4 and 37°C. NPs functionalized by using the adsorption and carbodiimide methods had different efficiencies, the carbodiimide approach being more efficient, stable, and reproducible. Furthermore, linking F4/80 and mannose to the NPs was demonstrated to increase J774A.1 macrophages' uptake. Overall, in vitro assays showed the nanosystem's efficacy to eliminate the Histoplasma capsulatum fungus and pave the way to design highly efficient nanocarriers for drug delivery against intracellular infections.

Additions to the knowledge of hydnoid Steccherinaceae: Cabalodontia, Etheirodon, Metuloidea, and Steccherinum.

The family Steccherinaceae includes genera with smooth, hydnoid, and poroid hymenophores, monomitic to dimitic hyphal systems, and generative hyphae with clamps or simple septa. Steccherinum is the largest genus in the family, with a worldwide distribution, and is characterized mainly by a dimitic hyphal system and presence of thick-walled encrusted cystidia. Species traditionally included in Steccherinum, however, have been transferred to other genera based on results of molecular phylogenetic analyses. Even though knowledge of Steccherinaceae has increased in the past few years, very little is known about the hydnoid species of the family, especially from the Neotropics. In this study, we present morphological and phylogenetic analyses on hydnoid specimens of Steccherinaceae collected in the Neotropics. Molecular data of nuc internal transcribed spacer region ITS1-5.8S-ITS rDNA (ITS) and portions of nuc 28S rDNA (28S), translation elongation factor 1-α (tef1), and the largest subunit of RNA polymerase II (rpb1) were obtained from Brazilian collections. Types and original collections were studied for morphological comparison. Samples we studied grouped in four different genera of Steccherinaceae: Cabalodontia, Etheirodon, Metuloidea, and Steccherinum. Three new neotropical species, Cabalodontia delicata, Etheirodon purpureum, and Steccherinum larssonii, are described. In addition, the new combinations Cabalodontia albofibrillosa and Metuloidea reniformis are proposed. The four genera presented in this study are compared and discussed in detail.

Experiencia en el tratamiento de tumores hepáticos mediante radioembolización con 90Y-microesferas de resina / Experience in the treatment of liver tumor with 90Y-resin microspheres radioembolization

INTRODUCCIÓN: El tratamiento de tumores hepáticos se realiza mediante resección quirúrgica. Cuando no es posible se emplean terapias alternativas localizadas como la radioembolización transarterial (TARE). MÉTODO: Estudio retrospectivo y descriptivo en 27 pacientes con tumor hepático no resecable sometidos a TARE con microesferas de resina cargadas con Ytrio-90. Se estudiaron características basales, demográficas y clínicas, y supervivencia global a 18 meses. El análisis de supervivencia se realizó mediante el método de Kaplan-Meier. RESULTADOS: El 81% de los pacientes fueron hombres y la edad osciló entre 52-85 años. El 78%, de los casos fueron tumores hepáticos primarios, destacando el carcinoma hepatocelular en estadio BCLC B (44%). El origen de tumor hepático secundario más frecuente fue adenocarcinoma colorrectal. El ECOG fue 0 para el 78% de los pacientes y los antecedentes alcoholismo (41%) y hepatitis C (56%). La media de actividad administrada en cada TARE fue 1,8 GBq (0,9-3,4 GBq). El 34% recibieron más de un tratamiento previo a la TARE: resección quirúrgica (11%), TAE o TACE (48%), ablación por radiofrecuencia (22%), inhibidores multiquinasas (15%). El 33% recibieron tratamiento posterior con inhibidores multiquinasas. La supervivencia global del total de pacientes a 18 meses fue del 58,9%. En pacientes con CHC BCLC B, la mediana de supervivencia fue de 15,6 meses. CONCLUSIÓN: Los resultados de supervivencia concuerdan con los de otros estudios, aunque existen diferencias en algunas de las variables. Es necesario disponer de mayor número de pacientes y tiempo de seguimiento para analizar su influencia en la supervivencia

INTRODUCTION: Transarterial radioembolization (TARE) is an alternative therapy for the treatment of unresectable liver tumors. METHOD: Retrospective and descriptive study in 27 patients undergoing TARE with Ytrio-90-loaded resin microspheres. Baseline, demographic and clinical characteristics were studied, and overall survival at 18 months was analyzed using the Kaplan-Meier method. RESULTS: Age ranged between 52-85 years, and 81% of patients were men. 78% presented primary liver tumors, highlighting hepatocellular carcinoma BCLC (Barcelona Clinic Liver Cancer) stage B (HCC BCLC B) (44%). The origin of the most frequent secondary liver tumor was colorectal adenocarcinoma. The ECOG (Eastern Cooperative Oncology Group) was 0 for 78% of the patients and the antecedents were alcoholism (41%) and hepatitis C (56%). The average administered activity was 1.8 GBq. 34% received more than one previous treatment: surgical resection (11%), transarterial embolization or chemoembolization (48%), radiofrequency ablation (22%) or multi-kinase inhibitors (15%). 33% received subsequent treatment with multi-kinase inhibitors. The overall survival at 18 months was 58.9%. In patients with HCC BCLC B, the median survival was 15.6 months. CONCLUSION: The survival results are in line with those of other studies, although there are differences in some of the variables. It is necessary to have more patients and follow-up time to analyze its influence on survival

Marcaje de leucocitos con 99mTc-exametazima y policitemia vera: un hallazgo casual / Leucocyte labelling with 99mTc-exametazime and polycythemia vera: a casual finding

La clasificación oficial de la Organización Mundial de la Salud de los tumores de tejidos hematopoyéticos y linfoides de 2016 introduce el concepto de policitemia vera (PV) enmascarada y revela que esta entidad ha sido infradiagnosticada en el pasado. Se presenta el caso de un varón de 49 años, fumador, intervenido de fractura de tobillo hace más de 15 años, remitido para valorar un posible proceso infeccioso asociado. Al no producirse separación previa de los hematíes por sedimentación durante el procedimiento de marcaje de leucocitos con 99mTc-exametazima se revisaron las causas de disminución de la velocidad de sedimentación globular. Entre ellas destacan la poliglobulia y el hábito tabáquico, ambas presentes en el paciente. Se recomendó realización de estudio hematológico que concluyó con el diagnóstico de PV. Las indicaciones del especialista en Radiofarmacia permitieron diagnosticar un caso no identificado hasta entonces, pese a que el paciente presentaba síntomas desde hacía años

The official World Health Organization classification of hematopoietic and lymphoid tissue tumors introduces in 2016 the concept of masked polycythemia vera (PV) and reveals that this entity has been underdiagnosed in the past. We present the case of a 49-year-old man, smoker, operated on for ankle fracture more than 15 years ago, referred to evaluate a possible associated infectious process. As there was no previous separation of the red blood cells by sedimentation during the leukocyte labelling procedure with 99mTc-exametazima, the causes of decreased erythrocyte sedimentation rate were reviewed. These include polyglobulia and smoking, both present in the patient. A haematological study was advised, which concluded with the diagnosis of PV. The indications of the specialist in Radiopharmacy allowed diagnosing a case not identified until then, although the patient had had symptoms for years

Review of serious events in cases of (suspected) child abuse and/or neglect: A RoSE by any other name?

Child abuse and neglect (CAN) cases presenting to health-services may be complex; when things go seriously wrong such as a child death or near miss, cases are reviewed and health-services and professionals subject to intense scrutiny. While there are a variety of mechanisms to review critical incidents in health-services no formal process for the review of cases where child protection is the primary concern exists in Australia. We aimed to develop a systematic process to review serious events in cases of suspected CAN across two health districts in Sydney, so that shared learnings could fuel system change. Drawing upon mapping, case review, literature findings and using quality improvement methodology, we developed a model named Review of Serious Events (RoSE), in suspected cases of CAN. The RoSE model has the key features of: being child focused; seeking to examine care over a period of time; using child protection staff as lead reviewers; involving health professionals/services in the review who have been involved with the child; and actioning systems change at local levels. The RoSE model was trialled through 2014-2015. Eight cases were reviewed using RoSE; cases were similar to those reviewed prior to having a model. Participant feedback from RoSE group processes was overwhelmingly positive; outputs were transparent and accessible to key stakeholders, there was mixed progress with implementation. The RoSE model is a serious case review process that is strongly child-focused, is both investigative and reflective, led by child protection experts; and can be adapted to other settings and systems.

Incidence, Distribution, and Association of Spongospora subterranea and Potato mop-top virus in Costa Rica.

A survey was conducted in 39 potato (Solanum tuberosum) fields in Costa Rica to determine incidence and association of Spongospora subterranea f. sp. subterranea and Potato mop-top pomovirus (PMTV). The fields were located in Costa Rica's two major potato-production regions and were further characterized by their altitude. In all, 633 paired samples of leaf tissue and corresponding tubers were collected, assessed visually for disease, and subsequently assayed by enzyme-linked immunosorbent assay (ELISA). S. subterranea presence in tuber tissue was tested by double-antibody sandwich (DAS)-ELISA and PMTV presence in leaf and tuber tissues was tested by triple-antibody sandwich (TAS)-ELISA. Moreover, soil samples were collected from 10 fields surveyed and were evaluated for both pathogens via ELISA and bioassay. The incidence of both diseases ranged from 0 to 100% within individual fields, with incidences lower than 40% occurring in more than 70% of the fields. Higher incidences were found in fields located at higher altitudes. Of the 633 paired samples, 179 and 146 were positive for PMTV and S. subterranea, respectively, according to ELISA in either the foliage or tubers. A low correlation was found for PMTV visual symptoms and ELISA test results. Only 14 of the 81 foliar samples testing positive for PMTV had visual symptoms; the remaining 67 samples were asymptomatic. Conversely, comparison of visual evaluation with detection of S. subterranea by ELISA on tubers showed that 70% of the results were coincident. S. subterranea was detected in 4 of 10 soil samples tested by ELISA. Soilborne PMTV was detected by ELISA in roots of bait plants sown in these soil samples. Co-occurrence of both pathogens was detected in 64 samples. A significant but low degree of association for vector and virus was determined, and data suggests that S. subterranea is participating in the transmission of PMTV in Costa Rica in low frequency.

Incidencia y distribución altitudinal de 13 virus en cultivos de solanum tuberosum (solanaceae) en Costa Rica / Incidence and altitudinal distribution of 13 virus cultures in Solanum tuberosum (Solanaceae) from Costa Rica

A survey was conducted in 30 fields located at three different altitudes in Cartago, Costa Rica's main potato producing area. Twenty plants were sampled per farm, for a total of 600 samples with 200 samples per altitude. ELISA was used with commercial reagents to independently test for PVX, PVY, PVM, PVA, PVS, PLRV, PMTV, PAMV, PVV, PVT, APLV, APMoV and TRSV. The presence of the following viruses was determined: PVX (77 %), PAMV (62 %), PLRV (42 %), TRSV (42 %), PVT (39 %), PVV (37 %), PMTV (31%), PVY (30 %), PVS (19 %), PVM (13 %), PVA (8 %), and APMoV (8%). APLV was not detected in any sample. This is the first report in Costa Rica of the presence of the viruses PMTV, PAMV, PVV, PVT and APMoV. A high viral incidence in the tuber seed production area as well as a high rate of mixed infections is reported.

En Cartago, la zona productora de papa más importante de Costa Rica, se realizó un muestreo en 30 fincas ubicadas a tres altitudes. Se recolectaron 20 plantas por finca y 200 muestras por altitud. Todas las muestras se analizaron independientemente mediante ELISA, para PVX, PVY, PVM, PVA, PVS, PLRV, PMTV, PAMV, PVV, PVT, APLV, APMoV y TRSV, utilizando reactivos comerciales. Se identificó la presencia de PVX (77 %), PAMV (62 %), PLRV (42 %), TRSV (42 %), PVT (39 %), PVV (37 %), PMTV (31 %), PVY (30 %), PVS (19 %), PVM (13 %), PVA (8 %), y APMoV (8 %). No se detectó APLV en ninguna de las muestras analizadas. Se informan por primera vez la presencia en Costa Rica de los virus PMTV, PAMV, PVV, PVT y APMoV. Se informa la alta incidencia viral en la zona dedicada a la producción de tubérculos como semilla y la alta tasa de infecciones mixtas.

[Incidence and altitudinal distribution of 13 virus cultures in Solanum tuberosum (Solanaceae) from Costa Rica]. / Incidencia y distribución altitudinal de 13 virus en cultivos de solanum tuberosum (solanaceae) en Costa Rica.

A survey was conducted in 30 fields located at three different altitudes in Cartago, Costa Rica's main potato producing area. Twenty plants were sampled per farm, for a total of 600 samples with 200 samples per altitude. ELISA was used with commercial reagents to independently test for PVX, PVY, PVM, PVA, PVS, PLRV, PMTV, PAMV, PVV, PVT, APLV, APMoV and TRSV. The presence of the following viruses was determined: PVX (77 %), PAMV (62 %), PLRV (42 %), TRSV (42 %), PVT (39 %), PVV (37 %), PMTV (31%), PVY (30 %), PVS (19 %), PVM (13 %), PVA (8 %), and APMoV (8%). APLV was not detected in any sample. This is the first report in Costa Rica of the presence of the viruses PMTV, PAMV, PVV, PVT and APMoV. A high viral incidence in the tuber seed production area as well as a high rate of mixed infections is reported.