Predicting students' academic progress and related attributes in first-year medical students: an analysis with artificial neural networks and Naïve Bayes.

BACKGROUND: Dropout and poor academic performance are persistent problems in medical schools in emerging economies. Identifying at-risk students early and knowing the factors that contribute to their success would be useful for designing educational interventions. Educational Data Mining (EDM) methods can identify students at risk of poor academic progress and dropping out. The main goal of this study was to use machine learning models, Artificial Neural Networks (ANN) and Naïve Bayes (NB), to identify first year medical students that succeed academically, using sociodemographic data and academic history. METHODS: Data from seven cohorts (2011 to 2017) of admitted medical students to the National Autonomous University of Mexico (UNAM) Faculty of Medicine in Mexico City were analysed. Data from 7,976 students (2011 to 2017 cohorts) of the program were included. Information from admission diagnostic exam results, academic history, sociodemographic characteristics and family environment was used. The main dataset included 48 variables. The study followed the general knowledge discovery process: pre-processing, data analysis, and validation. Artificial Neural Networks (ANN) and Naïve Bayes (NB) models were used for data mining analysis. RESULTS: ANNs models had slightly better performance in accuracy, sensitivity, and specificity. Both models had better sensitivity when classifying regular students and better specificity when classifying irregular students. Of the 25 variables with highest predictive value in the Naïve Bayes model, percentage of correct answers in the diagnostic exam was the best variable. CONCLUSIONS: Both ANN and Naïve Bayes methods can be useful for predicting medical students' academic achievement in an undergraduate program, based on information of their prior knowledge and socio-demographic factors. Although ANN offered slightly superior results, Naïve Bayes made it possible to obtain an in-depth analysis of how the different variables influenced the model. The use of educational data mining techniques and machine learning classification techniques have potential in medical education.

Accidente vascular encefálico isquémico como manifestación de mixoma auricular. Presentación de un caso

La enfermedad cerebrovascular constituye una de las principales causas de muerte a nivel mundial. Múltiples factores desencadenan los accidentes vasculares encefálicos isquémicos, entre ellas los tumores cardiacos, como el mixoma auricular. Se presenta el caso de una paciente femenina de 32 años, que al examen físico mostró afasia motora, hemiplejia fascio-braquio-crural derecha y discreta paresia de la mirada vertical con nistagmos. Se realizaron estudios de imagen (tomografía de cráneo, ecocardiograma transtorácico y angiotomografía de vasos de cuello) sugerentes de embolización sistémica en el territorio de la carótida izquierda, secundarios a la fragmentación de un tumor cardiaco. Se decide derivar a la paciente a cirugía cardiovascular para endarectomía carotídea con exéresis del tumor cardiaco, el cual evolucionó satisfactoriamente. Persistió el daño neurológico debido al tiempo transcurrido entre el diagnóstico y el tratamiento. Teniendo en cuenta la baja frecuencia del mixoma cardiaco y la posibilidad de asociarse con ictus isquémico se decide presentar este caso.

Cerebrovascular disease is one of the main causes of death worldwide. Multiple factors trigger ischemic strokes, including cardiac tumors such as atrial myxoma. A 32-years-old female patient, who on physical examination showed motor aphasia, right fascio-brachio-crural hemiplegia and discrete vertical gaze paresis with nystagmus is presented. Imaging studies were performed (skull tomography, transthoracic echocardiogram and angiotomography of neck vessels) suggestive of systemic embolization in the left carotid territory, secondary to the fragmentation of a cardiac tumor. It was decided to refer the patient to cardiovascular surgery for carotid endarectomy with excision of the cardiac tumor, which progressed satisfactorily. Neurological damage persisted due to the time elapsed between diagnosis and treatment. Taking into account the low frequency of cardiac myxoma and the possibility of being associated with ischemic stroke, it was decided to present this case.

Influence of Storage Time on the DNA Integrity and Viability of Spermatozoa of the Spider Crab Maja brachydactyla.

Natural populations of the spider crab Maja brachydactyla constitute a fishery resource of great economic importance in many countries. As in the rest of eubrachyurans, the females of this species have ventral-type seminal receptacles where they store sperm from copulations. Sperm can be stored in these structures for months and even years before egg fertilisation, with the consequent degradation of the sperm cells during the time. In this work, we analyse the viability and the possible genetic damage in sperm accumulated in the seminal receptacles of M. brachydactyla females as a function of the storage time (from 0 to 14 months) using the comet assay technique. On one hand, we developed an algorithm for comet image analysis that improves the comet segmentation compared with the free software Open comet v1.3.1 (97% vs. 76% of detection). In addition, our software allows the manual modification of the contours wrongly delimited via the automatic tool. On the other hand, our data show a sharp decline in sperm viability and DNA integrity in the first four months of storage, which could lead to a decrease in the fecundity rate and/or viability of the embryos or larvae from the second and third clutches of the annual cycle if the repair capacity in these gametic cells is low.

Nivel de conocimiento de Enfermería sobre manejo del catéter implantable del Hospital Pediátrico, Chaco 2022 / Level of nursing knowledge about the managementof the implantable catheter at the Pediatric Hospital, Chaco 2022

Introducción: el catéter implantable en pacientes pediátricos es uno de los elementos más usados e importantes, utilizados en tratamientos por plazos extendidos. Estos dispositivos son de incumbencia del área de enfermería en cuanto a su mantenimiento y cuidado, con su dominio se brinda confort y mayor seguridad al paciente. Objetivo: determinar el nivel de conocimiento del profesional de enfermería sobre el manejo del catéter implantable en servicios de internación de un Hospital Pediátrico, Chaco, año 2022. Metodología: estudio cuantitativo, descriptivo, transversal y observacional; población en estudio la totalidad del personal de enfermería del servicio de internación; se usó como instrumento de recolección de datos un cuestionario escrito, que contenía las variables sociodemográficas y de conocimientos de aspectos generales, conocimientos en la habilitación y mantenimiento del catéter implantable. Resultados: los resultados obtenidos en la investigación manifiestan un nivel regular de conocimientos en aspectos generales del catéter implantable, sin embargo, el nivel en cuanto a la habilitación y mantenimiento del dispositivo se apreció que fue bueno, con respecto al nivel de conocimiento en la habilitación y mantenimiento del catéter implantable según formación académica alcanzada del personal que trabajan en los servicios de internación, se observó que los licenciados en enfermería y especialista obtuvieron un mayor porcentaje en conocimiento bueno. Conclusión: se concluye que existen aspectos generales sobre el manejo del catéter implantable que requieren un refuerzo en los conocimientos por parte del personal de enfermería en pos de la mejora continua en el cuidado [AU]

Introduction: the implantable catheter in pediatric patients is one of the most used and important elements, used in treatments for extended periods. These devices are the responsibility of the nursing area in terms of their maintenance and care, with their control comfort and greater safety are provided to the patient. Objective: To determine the level of knowledge of the nursing professional on the management of the implantable catheter in hospitalization services of a Pediatric Hospital, Chaco, year 2022. Methodology: quantitative, descriptive, cross-sectional and observational study; study population the entire nursing staff of the hospitalization service. A written questionnaire was used as a data collection instrument, which contained the sociodemographic variables and knowledge of general aspects, knowledge in the habilitation and maintenance of the implantable catheter. Results: the results obtained in the investigation show a regular level of knowledgein general aspects of the implantable catheter, however, the level[AU]

Introdução: o cateter implantável em pacientes pediátricos é um dos elementos mais utilizados e importantes, sendo utilizado em tratamentos por períodos prolongados. Esses aparelhos são de responsabilidade da área de enfermagem quanto a sua manutenção e cuidados, com seu controle seja proporcionado conforto e maior segurança ao paciente. Objetivo: determinar o nível de conhecimento do profissional de enfermagem sobre o manejo do cateter implantável nos serviços de internação de um Hospital Pediátrico, Chaco, ano 2022. Metodologia: estudo quantitativo, descritivo, transversal e observacional; população do estudo toda a equipe de enfermagem do serviço de internação. Como instrumento de coleta de dados foi utilizado um questionário escrito, que continha as variáveis sociodemográficas e conhecimentos sobre aspectos gerais, conhecimentos na habilitação e manutenção do cateter implantável. Resultados: os resultados obtidos na investigação mostram um nível regular de conhecimento em aspectos gerais do cateter implantável, no entanto, o nível quanto à qualificação e manutenção do dispositivo foi avaliado como bom, no que diz respeito ao nível de conhecimento na qualificação e manutenção do cateter implantável de acordo com a formação acadêmica alcançada pela equipe que atua nos serviços de internação, observouse que os graduados em enfermagem e especialistas obtiveram maior percentual de bom conhecimento. Conclusão: concluise que existem aspectos gerais sobre o manejo do cateter implantável que requerem um reforço de conhecimento por parte da equipe de enfermagem em busca da melhoria contínua na assistência[AU]

Molecular Trojan Horses for treating lysosomal storage diseases.

Lysosomal storage diseases (LSDs) are caused by monogenic mutations in genes encoding for proteins related to the lysosomal function. Lysosome plays critical roles in molecule degradation and cell signaling through interplay with many other cell organelles, such as mitochondria, endoplasmic reticulum, and peroxisomes. Even though several strategies (i.e., protein replacement and gene therapy) have been attempted for LSDs with promising results, there are still some challenges when hard-to-treat tissues such as bone (i.e., cartilages, ligaments, meniscus, etc.), the central nervous system (mostly neurons), and the eye (i.e., cornea, retina) are affected. Consistently, searching for novel strategies to reach those tissues remains a priority. Molecular Trojan Horses have been well-recognized as a potential alternative in several pathological scenarios for drug delivery, including LSDs. Even though molecular Trojan Horses refer to genetically engineered proteins to overcome the blood-brain barrier, such strategy can be extended to strategies able to transport and deliver drugs to specific tissues or cells using cell-penetrating peptides, monoclonal antibodies, vesicles, extracellular vesicles, and patient-derived cells. Only some of those platforms have been attempted in LSDs. In this paper, we review the most recent efforts to develop molecular Trojan Horses and discuss how this strategy could be implemented to enhance the current efficacy of strategies such as protein replacement and gene therapy in the context of LSDs.

Genome Editing Tools for Lysosomal Storage Disorders.

Genome editing has multiple applications in the biomedical field. They can be used to modify genomes at specific locations, being able to either delete, reduce, or even enhance gene transcription and protein expression. Here, we summarize applications of genome editing used in the field of lysosomal disorders. We focus on the development of cell lines for study of disease pathogenesis, drug discovery, and pathogenicity of specific variants. Furthermore, we highlight the main studies that use gene editing as a gene therapy platform for these disorders, both in preclinical and clinical studies. We conclude that gene editing has been able to change quickly the scenario of these disorders, allowing the development of new therapies and improving the knowledge on disease pathogenesis. Should they confirm their hype, the first gene editing-based products for lysosomal disorders could be available in the next years.

Fitting In While Standing Out: Professional Identity Formation, Imposter Syndrome, and Burnout in Early-Career Faculty Physicians.

PURPOSE: Professional identity formation (PIF) is a dynamic process by which an individual internalizes the core values and beliefs of a specific profession. Within medical education, PIF begins in medical school and continues throughout training and practice. Transitions affect PIF, with a critical transition occurring between medical training and unsupervised practice. This study aims to characterize PIF during the transition from resident to early-career faculty physician and explores the relationship between PIF and burnout during this transition. METHOD: The authors conducted a qualitative study using constructivist grounded theory. They conducted semistructured interviews with early-career faculty physicians (defined as practicing for ≤ 5 years) from the Department of Medicine, Mayo Clinic. Deidentified interview transcripts were processed through open and axial coding. The authors organized themes and identified relationships between themes that were refined through discussion and constant comparison with newly collected data. During data analysis, the authors identified self-determination theory, with the concepts of autonomy, competence, and relatedness, as a framework to support the organization and analysis of the data. RESULTS: Eleven early-career faculty physicians participated in the interviews. Their PIF was characterized by the dual desires to fit in and stand out. Striving for these desires was characterized by imposter syndrome, driving physicians to question their decision making and overall competence. Participants associated imposter syndrome and academic pressures with burnout. Autonomy support by the institution to pursue opportunities important for career development helped mitigate burnout and support PIF. CONCLUSIONS: Early-career faculty physicians face identity challenges when transitioning from training to unsupervised practice, including striving to fit in and stand out. They link this tension to imposter syndrome, which they associated with burnout. Institutional awareness and support, including addressing structural and cultural contributors to imposter syndrome, are paramount as new faculty explore their identities and navigate new challenges.

Burkitt Lymphoma Presenting as Ileocolic Intussusception in an Adult.

Adult intussusception is rare, highly associated with a malignant lead point, and often requires emergent surgical management. We report the case of a 44-year-old male who presented with generalized abdominal pain and was found to have early ileocolic intussusception secondary to a large ileocecal mass. Biopsies of the mass and an enlarged cardiophrenic lymph node, as well as pleural fluid cytology were all consistent with Burkitt lymphoma (BL). Curiously, the patient's abdominal exam was reassuring, and the intussusception and malignant bowel obstruction resolved over 36 hours with conservative management alone. With a Burkitt lymphoma international prognostic index (BL-IPI) score of 2, the patient proceeded to treatment with combination chemoimmunotherapy and attained a complete response after four cycles. There was no bowel perforation or recurrent intussusception throughout treatment. Thus, this report marks the first reported case of adult BL-associated intussusception to resolve with non-invasive management and establishes a precedent for conservative management in select patients.

Uniaxial and Coaxial Nanofibers PCL/Alginate or PCL/Gelatine Transport and Release Tamoxifen and Curcumin Affecting the Viability of MCF7 Cell Line.

Breast cancer is the second cause of cancer death in women worldwide. The search for therapeutic and preventive alternatives has increased in recent years. One synthetic drug for patients with hormone receptor-positive tumours is tamoxifen citrate (TMX). Curcumin (Cur) is a natural compound that is being tested. Both were coupled with nanoscale-controlled and sustained release systems to increase the effectiveness of the treatment and reduce adverse effects. We produced a controlled release system based on uniaxial and coaxial polymeric nanofibers of polycaprolactone (PCL), alginate (Alg) and gelatine (Gel) for the transport and release of TMX and Cur, as a new alternative to breast cancer treatment. Nanofibers combining PCL-Alg and PCL-Gel were fabricated by the electrospinning technique and physicochemically characterised by thermal analysis, absorption spectroscopy in the infrared region and X-ray diffraction. Morphology and size were studied by scanning electron microscopy. Additionally, the release profile of TMX and Cur was obtained by UV-Vis spectroscopy. Additionally, the cytotoxic effect on breast cancer cell line MCF7 and peripheral-blood mononuclear cells (PBMCs) from a healthy donor were evaluated by a Resazurin reduction assay. These assays showed that PCL-TMX nanofiber was highly toxic to both cell types, while PCL-Cur was less toxic.

Delivery and assessment of a CRISPR/nCas9-based genome editing system on in vitro models of mucopolysaccharidoses IVA assisted by magnetite-based nanoparticles.

Mucopolysaccharidosis IV A (MPS IVA) is a lysosomal disorder caused by mutations in the GALNS gene. Consequently, the glycosaminoglycans (GAGs) keratan sulfate and chondroitin 6-sulfate accumulate in the lysosomal lumen. Although enzyme replacement therapy has shown essential advantages for the patients, several challenges remain to overcome, such as the limited impact on the bone lesion and recovery of oxidative profile. Recently, we validated a CRISPR/nCas9-based gene therapy with promising results in an in vitro MPS IVA model. In this study, we have expanded the use of this CRISPR/nCas9 system to several MPS IVA fibroblasts carrying different GALNS mutations. Considering the latent need to develop more safety vectors for gene therapy, we co-delivered the CRISPR/nCas9 system with a novel non-viral vector based on magnetoliposomes (MLPs). We found that the CRISPR/nCas9 treatment led to an increase in enzyme activity between 5 and 88% of wild-type levels, as well as a reduction in GAGs accumulation, lysosomal mass, and mitochondrial-dependent oxidative stress, in a mutation-dependent manner. Noteworthy, MLPs allowed to obtain similar results to those observed with the conventional transfection agent lipofectamine. Overall, these results confirmed the potential of CRISPR/nCas9 as a genome editing tool for treating MPS IVA. We also demonstrated the potential use of MLPs as a novel delivery system for CRISPR/nCas9-based therapies.

Sphingolipids and their role in health and disease in the central nervous system.

Sphingolipids (SLs) are lipids derived from sphingosine, and their metabolism involves a broad and complex network of reactions. Although SLs are widely distributed in the body, it is well known that they are present in high concentrations within the central nervous system (CNS). Under physiological conditions, their abundance and distribution in the CNS depend on brain development and cell type. Consequently, SLs metabolism impairment may have a significant impact on the normal CNS function, and has been associated with several disorders, including sphingolipidoses, Parkinson's, and Alzheimer's. This review summarizes the main SLs characteristics and current knowledge about synthesis, catabolism, regulatory pathways, and their role in physiological and pathological scenarios in the CNS.

Immunochemical and biophysical characterization of inactivated Sabin poliovirus products: Insights into rapid quality assessment tools.

The aim of this study was to demonstrate the strength of combining immunochemical and biophysical analysis tools for assessing the quality of Sabin inactivated poliovirus vaccine (Sabin-IPV) bulk products. We assessed Sabin-IPV serotypes 1, 2 and 3 from six different manufacturers and evaluated their comparability through biosensor analysis and biophysical characterization methods, including tryptophan fluorescence and asymmetrical flow field-flow fractionation - multi-angle light scattering analysis. These methods enabled us to assess antigenic as well as conformational and structural integrity profiles, respectively. Based on Sabin-IPV samples that were subjected to accelerated storage conditions, we revealed that existing immunochemical methods exhibit remarkably similar trends to the results obtained by the biophysical characterization methods. While the results underpin that the comparability of Sabin-IPV bulk products of different manufacturers is weak, information about their quality can rapidly be obtained by using both immunochemical and biophysical methods. Furthermore, the study highlights that quality assessment of Sabin-IPV can be obtained through biophysical techniques can complement the assessments performed with monoclonal antibodies and suggests that similar techniques could be employed to characterize other enteroviruses.

GM2 Gangliosidoses: Clinical Features, Pathophysiological Aspects, and Current Therapies.

GM2 gangliosidoses are a group of pathologies characterized by GM2 ganglioside accumulation into the lysosome due to mutations on the genes encoding for the ß-hexosaminidases subunits or the GM2 activator protein. Three GM2 gangliosidoses have been described: Tay-Sachs disease, Sandhoff disease, and the AB variant. Central nervous system dysfunction is the main characteristic of GM2 gangliosidoses patients that include neurodevelopment alterations, neuroinflammation, and neuronal apoptosis. Currently, there is not approved therapy for GM2 gangliosidoses, but different therapeutic strategies have been studied including hematopoietic stem cell transplantation, enzyme replacement therapy, substrate reduction therapy, pharmacological chaperones, and gene therapy. The blood-brain barrier represents a challenge for the development of therapeutic agents for these disorders. In this sense, alternative routes of administration (e.g., intrathecal or intracerebroventricular) have been evaluated, as well as the design of fusion peptides that allow the protein transport from the brain capillaries to the central nervous system. In this review, we outline the current knowledge about clinical and physiopathological findings of GM2 gangliosidoses, as well as the ongoing proposals to overcome some limitations of the traditional alternatives by using novel strategies such as molecular Trojan horses or advanced tools of genome editing.

Transforaminal Endoscopic Thoracic Discectomy: Technical Review to Prevent Complications.

For all the spine surgeons, thoracic disc herniations (TDHs) entrust a real challenge in terms of patient diagnosis, proper selection, surgical technique, and potential adverse events. TDHs are relatively uncommon compared to the lumbar and cervical levels. Literature reports a variable prevalence of TDHs around 6% to 40%, but less than 1% of all disk herniations are symptomatic TDHs, evidencing as a relatively unusual condition. Nowadays, transforaminal endoscopic thoracic discectomy (TETD) has been implemented as an alternative to classic open procedures with results that are as good as and, in some situations, better than those in traditional discectomy. However, the surgeon must be familiar with endoscopic lumbar spine surgery before opting to perform a TETD, considering that the learning curve is much harder. We describe all the steps and safety considerations during TETD based on the anatomic differences compared to lumbar endoscopic procedures. TETD is an effective and safe method that yields more benefits, provides a direct route to the lesion with less morbidity, and is performed in a minimally invasive way. Many severe complications related to the thoracic region could be avoided having the proper knowledge, adequate technique, and safety routes and considerations.

A perspective on research, diagnosis, and management of lysosomal storage disorders in Colombia.

Lysosomal storage diseases (LSDs) are a group of about 50 inborn errors of metabolism characterized by the lysosomal accumulation of partially or non-degraded molecules due to mutations in proteins involved in the degradation of macromolecules, transport, lysosomal biogenesis or modulators of lysosomal environment. Significant advances have been achieved in the diagnosis, management, and treatment of LSDs patients. In terms of approved therapies, these include enzyme replacement therapy (ERT), substrate reduction therapy, hematopoietic stem cell transplantation, and pharmacological chaperone therapy. In this review, we summarize the Colombian experience in LSDs thorough the evidence published. We identified 113 articles published between 1995 and 2019 that included Colombian researchers or physicians, and which were mainly focused in Mucopolysaccharidoses, Pompe disease, Gaucher disease, Fabry disease, and Tay-Sachs and Sandhoff diseases. Most of these articles focused on basic research, clinical cases, and mutation reports. Noteworthy, implementation of the enzyme assay in dried blood samples, led to a 5-fold increase in the identification of LSD patients, suggesting that these disorders still remain undiagnosed in the country. We consider that the information presented in this review will contribute to the knowledge of a broad spectrum of LSDs in Colombia and will also contribute to the development of public policies and the identification of research opportunities.

Therapeutic Options for Mucopolysaccharidoses: Current and Emerging Treatments.

Mucopolysaccharidoses (MPS) are inborn errors of metabolism produced by a deficiency of one of the enzymes involved in the degradation of glycosaminoglycans (GAGs). Although taken separately, each type is rare. As a group, MPS are relatively frequent, with an overall estimated incidence of around 1 in 20,000-25,000 births. Development of therapeutic options for MPS, including hematopoietic stem cell transplantation (HSCT) and enzyme replacement therapy (ERT), has modified the natural history of many MPS types. In spite of the improvement in some tissues and organs, significant challenges remain unsolved, including blood-brain barrier (BBB) penetration and treatment of lesions in avascular cartilage, heart valves, and corneas. Newer approaches, such as intrathecal ERT, ERT with fusion proteins to cross the BBB, gene therapy, substrate reduction therapy (SRT), chaperone therapy, and some combination of these strategies may provide better outcomes for MPS patients in the near future. As early diagnosis and early treatment are imperative to improve therapeutic efficacy, the inclusion of MPS in newborn screening programs should enhance the potential impact of treatment in reducing the morbidity associated with MPS diseases. In this review, we evaluate available treatments, including ERT and HSCT, and future treatments, such as gene therapy, SRT, and chaperone therapy, and describe the advantages and disadvantages. We also assess the current clinical endpoints and biomarkers used in clinical trials.

Oclusión Endovascular De Arteria Carótida Interna Aberrante Como Causa De Tinnitus Pulsátil / Endovascular Occlusion Of Aberrant Internal Carotid Artery Causing Tinnitus

RESUMEN Presentamos el caso de un paciente de 43 años con historia de tinnitus crónico intratable y pulsátil debido al curso aberrante de la arteria carótida interna derecha. En los estudios complementarios, la arteriografía mostró un polígono arterial de Willis preservado y un test de oclusión permeable sin síntomas neurológicos a la oclusión de la arteria carótida derecha. Se realizó oclusión endovascular de la arteria carótida interna derecha en las porciones petrosa y lacerum, con alivio inmediato de los síntomas.

ABSTRACT We present a case of a 43-years old male patient with a history of chronic and intractable pulsatile tinnitus due to an aberrant course of the right internal carotid artery. In complementary studies, the angiography showed a preserved Willis' arterial polygon and a balloon-occlusion test with adequate patency and no neurological symptoms. We performed the endovascular occlusion of the right internal carotid artery in the petrous and lacerum portions with the relief of symptoms.

Silver bioaccumulation in chironomid larvae as a potential source for upper trophic levels: a study case from northern Patagonia.

Silver (Ag) is a pollutant of high concern in aquatic ecosystems, considered among the most toxic metallic ions. In lacustrine environments, contaminated sediments are a source of Ag for the food web. Chironomidae (Insecta: Diptera) are the most abundant, diverse, and representative insect groups in aquatic ecosystems. Chironomid larvae are closely associated to benthic substrates and link primary producers and secondary consumers. Given their trophic position and their life habits, these larvae can be considered the entry point for the transference of Ag, from the benthic deposit to the higher trophic levels of the food web. Previous studies in lakes from Nahuel Huapi National Park (Northern Patagonia) showed Ag enrichment over background levels (0.04-0.1 µg g-1 dry weight) both in biota (bivalves and fish liver) and sediments from sites near human settlements. The aim of this study was to analyze the role of chironomids in the transference of Ag from the benthic reservoir of Lake Moreno Oeste to the food web. The concentration of Ag in chironomid larvae tissue ranged from 0.1 to 1.5 µg g-1 dry weight, reaching a bioaccumulation factor up to 17 over substrates and depending on the associated substrate type, feeding habitats, larval stage, and season. The main Ag transfer to higher trophic levels by chironomids occurs in the littoral zone, mostly from larvae inhabiting submerged vegetation (Myriophyllum quitense) and sediment from vegetated zones. This study presents novel evidence of the doorway role played by chironomid larvae in Ag pathways from the sediments into food webs of freshwater ecosystems.

Efficient antibacterial nanosponges based on ZnO nanoparticles and doxycycline.

Bacterial soft rot is responsible for the loss of about 25% of worldwide production in vegetables and fruits. Efforts have been made to develop an effective nanosponge with the capacity to load and release antibacterial drugs to protect plants. Based on the potential of the ZnO nanoparticles (ZnO-NPs) to achieve this goal, this study synthesized NP via the sol-gel and hydrothermal methods by controlling native defects, such as oxygen vacancies, using thermal treatments and reduced atmospheres. To characterize the ZnO NPs, X-ray diffraction (XRD), Raman spectroscopy, transmission electron microscopy (TEM), optical spectroscopy, electron paramagnetic resonance (EPR), Zeta Potential measurements and surface area with the Brunauer-Emmett-Teller (BET) method were used. The photophysical and photochemical properties via spin trapping method aligned with EPR using UVA light showed a greater formation of electron-hole pairs and hydroxyl radicals for the reduced ZnO NPs when compared with the oxidized ones. Additionally, we found that reduced ZnO-NPs have high effectively against Escherichia coli, Erwinia carotovora and Pantoea sp. bacteria using the photocatalytic effect in the UV range. Moreover, ZnO-NPs loaded with DOX release profile enables the release of DOX within 46days, where 25% was released during the first 10h followed by a second delivery phase with an interesting short-term efficacy (<1day) against E. carotovora and Pantoea sp. Bacteria. For the first time, it was demonstrated that ZnO-NPs and ZnO-NPs loaded with DOX have efficient UV photocatalytic activities against bacterial soft rot infections.

Radiological evolution of porcine neurocysticercosis after combined antiparasitic treatment with praziquantel and albendazole.

BACKGROUND: The onset of anthelmintic treatment of neurocysticercosis (NCC) provokes an acute immune response of the host, which in human cases is associated with exacerbation of neurological symptoms. This inflammation can occur at the first days of therapy. So, changes in the brain cysts appearance may be detected by medical imaging. We evaluated radiological changes in the appearance of brain cysts (enhancement and size) on days two and five after the onset of antiparasitic treatment using naturally infected pigs as a model for human NCC. METHODS AND RESULTS: Contrast T1-weighted magnetic resonance imaging with gadolinium was performed before and after antiparasitic treatment. Eight NCC-infected pigs were treated with praziquantel plus albendazole and euthanized two (n = 4) and five (n = 4) days after treatment; another group of four infected pigs served as untreated controls. For each lesion, gadolinium enhancement intensity (GEI) and cyst volume were measured at baseline and after antiparasitic treatment. Volume and GEI quantification ratios (post/pre-treatment measures) were used to appraise the effect of treatment. Cysts from untreated pigs showed little variations between their basal and post treatment measures. At days 2 and 5 there were significant increases in GEI ratio compared with the untreated group (1.32 and 1.47 vs 1.01, p = 0.021 and p = 0.021). Cyst volume ratios were significantly lower at days 2 and 5 compared with the untreated group (0.60 and 0.22 vs 0.95, p = 0.04 and p = 0.02). Cysts with lower cyst volume ratios showed more marked post-treatment inflammation, loss of vesicular fluid and cyst wall wrinkling. CONCLUSION/SIGNIFICANCE: A significant and drastic reduction of cyst size and increased pericystic enhancement occur in the initial days after antiparasitic treatment as an effect of acute perilesional immune response. These significant changes showed that early anthelmintic efficacy (day two) can be detected using magnetic resonance imaging.