Loss of oligodendrocyte ErbB receptor signaling leads to hypomyelination, reduced density of parvalbumin-expressing interneurons, and inhibitory function in the auditory cortex.

For a long time, myelin was thought to be restricted to excitatory neurons, and studies on dysmyelination focused primarily on excitatory cells. Recent evidence showed that axons of inhibitory neurons in the neocortex are also myelinated, but the role of myelin on inhibitory circuits remains unknown. Here we studied the impact of mild hypomyelination on both excitatory and inhibitory connectivity in the primary auditory cortex (A1) with well-characterized mouse models of hypomyelination due to loss of oligodendrocyte ErbB receptor signaling. Using laser-scanning photostimulation, we found that mice with mild hypomyelination have reduced functional inhibitory connections to A1 L2/3 neurons without changes in excitatory connections, resulting in altered excitatory/inhibitory balance. These effects are not associated with altered expression of GABAergic and glutamatergic synaptic components, but with reduced density of parvalbumin-positive (PV+ ) neurons, axons, and synaptic terminals, which reflect reduced PV expression by interneurons rather than PV+ neuronal loss. While immunostaining shows that hypomyelination occurs in both PV+ and PV- axons, there is a strong correlation between MBP and PV expression, suggesting that myelination influences PV expression. Together, the results indicate that mild hypomyelination impacts A1 neuronal networks, reducing inhibitory activity, and shifting networks towards excitation.

Occurrence of the bacteria in a hospital environment and their sensitivity profile to the main antimicrobials in a reference general hospital in Curitiba, Brazil / Ocorrência de bactérias em ambiente hospitalar, e seu perfil de sensibilidade aos principais antimicrobianos em um hospital de referência em Curitiba, Brasil / Ocurrencia de bacterias en ambiente hospitalario y su perfil de sensibilidad a los principales antimicrobianos en un hospital de referencia en Curitiba, Brasil

Introduction: Antimicrobial resistance rates are increasing in both hospital and community settings, creating a favorable environment for the development of superbacteria. Therefore, local studies are necessary for the proper management of current antimicrobial arsenals and for addressing the current bacteriological scenario. Aim: The aim of this study is to profile bacterial epidemiology in a hospital in Curitiba, Brazil and associate it with the effectiveness of antimicrobial therapy. Methodology: Data from 2019 to 2021 were collected by the Center for Epidemiology and Hospital Infection Control (CEHIC), and this was a quantitative single-center study. Results: The most commonly detected microorganisms were Escherichia coli, Staphylococcus aureus, Klebsiella pneumoniae, Staphylococcus epidermidis, Pseudomonas aeruginosa, Enterococcus faecalis, Acinetobacter baumannii, Staphylococcus haemolyticus, Staphylococcus hominis, and Enterobacter cloacae. A. baumannii and K. pneumoniae had the lowest mean sensitivity coefficients, while S. aureus was the most sensitive. Erythromycin was the least effective antimicrobial agent, while daptomycin was the most effective. Conclusion: These results are consistent with the literature and can be used to optimize empiric therapies, as there are already important therapeutic failures associated with antimicrobial resistance.

Introdução: As taxas de resistência antimicrobiana estão em ascensão tanto em ambientes hospitalares como comunitários, criando um cenário propício para o desenvolvimento de superbactérias e, assim, torna-se necessário estudos locais para uma gestão adequada dos arsenais antimicrobianos atuais e frente ao cenário bacteriológico atual. Objetivo: O escopo desse estudo visa traçar o perfil epidemiológico bacteriano num hospital em Curitiba, Brasil e associá-lo à eficácia da terapia antimicrobiana. Metodologia: Os dados de 2019 a 2021 foram recolhidos pelo Centro de Epidemiologia e Controle de Infecções Hospitalares (CECIH), sendo este um estudo unicêntrico quantitativo. Resultados: Escherichia coli, Staphylococcus aureus, Klebsiella pneumoniae, Staphylococcus epidermidis, Pseudomonas aeruginosa, Enterococcus faecalis, Acinetobacter baumannii, Staphylococcus haemolyticus, Staphylococcus hominis, e Enterobacter cloacae foram os microrganismos mais comuns detectados. A. baumannii e K. pneumoniae tinham as médias de coeficiente de sensibilidade mais baixas, enquanto S. aureus era o mais sensível. A eritromicina era o agente antimicrobiano menos eficaz, enquanto a daptomicina era o mais eficaz. Conclusão: Estes resultados estão de acordo com a literatura e podem ser utilizados para otimizar as terapias empíricas, visto que já há falhas terapêuticas importantes associadas a resistência antimicrobiana.

Introducción: Las tasas de resistencia antimicrobiana están en aumento tanto en el ámbito hospitalario como en el comunitario, creando un escenario propicio para el desarrollo de superbacterias, por lo que son necesarios estudios locales para una gestión adecuada de los actuales arsenales antimicrobianos y hacer frente al escenario bacteriológico actual. Objetivo: El alcance de este estudio pretende trazar el perfil epidemiológico bacteriano en un hospital de Curitiba, Brasil y asociarlo a la eficacia de la terapia antimicrobiana. Metodología: Los datos de 2019 a 2021 fueron recogidos por el Centro de Epidemiología y Control de Infecciones Hospitalarias (CECIH), siendo un estudio cuantitativo unicéntrico. Resultados: Escherichia coli, Staphylococcus aureus, Klebsiella pneumoniae, Staphylococcus epidermidis, Pseudomonas aeruginosa, Enterococcus faecalis, Acinetobacter baumannii, Staphylococcus haemolyticus, Staphylococcus hominis y Enterobacter cloacae fueron los microorganismos más frecuentes detectados. A. baumannii y K. pneumoniae presentaron los coeficientes medios de sensibilidad más bajos, mientras que S. aureus fue el más sensible. La eritromicina fue el agente antimicrobiano menos eficaz, mientras que la daptomicina fue el más eficaz. Conclusión: Estos resultados concuerdan con la literatura y pueden ser utilizados para optimizar las terapias empíricas, pues ya existen importantes fracasos terapéuticos asociados a la resistencia antimicrobiana.

Cancer in the head and neck region and its face under the perspective of users of a public reference hospital in Recife, state of Pernambuco, Brazil

Introduction: In Brazil, cancer is a public health problem because of its epidemiological, social, and economic amplitude. Objective: This study aimed to identify and analyze the difficulties experienced by head and neck (H&N) cancer patients, who are users of the Brazilian public health system (SUS), from their perspective of diagnosis to post-treatment. Methods: Qualitative case series carried out using individual semistructured interviews. Data were collected from October 2019 to March 2020 and interpreted by content analysis. Results: Three categories emerged from the analysis: "difficulties in the diagnosis phase", "conflicts experienced during treatment" and "post-treatment difficulties/sequelae". Corroborating the literature, it was found that the difficulties faced by cancer patients are present in all stages of the disease: from access to prevention health services and diagnosis to post-treatment, influenced by late diagnosis, treatment side effects, and disease comorbidities. Conclusion: It is essential to carry out studies addressing changes in the family, professional and personal scope of cancer patients, aiming to provide them with comprehensive care and health professionals with understanding about what this disease represents in the life of these individuals.

Identification of in vivo roles of ErbB4-JMa and its direct nuclear signaling using a novel isoform-specific knock out mouse.

Like all receptor tyrosine kinases (RTKs), ErbB4 signals through a canonical signaling involving phosphorylation cascades. However, ErbB4 can also signal through a non-canonical mechanism whereby the intracellular domain is released into the cytoplasm by regulated intramembrane proteolysis (RIP) and translocates to the nucleus where it regulates transcription. These different signaling mechanisms depend on the generation of alternative spliced isoforms, a RIP cleavable ErbB4-JMa and an uncleavable ErbB4-JMb. Non-canonical signaling by ErbB4-JMa has been implicated in the regulation of brain, heart, mammary gland, lung, and immune cell development. However, most studies on non-canonical ErbB4 signaling have been performed in vitro due to the lack of an adequate mouse model. We created an ErbB4-JMa specific knock out mouse and demonstrate that RIP-dependent, non-canonical signaling by ErbB4-JMa is required for the regulation of GFAP expression during cortical development. We also show that ErbB4-JMa signaling is not required for the development of the heart, mammary glands, sensory ganglia. Furthermore, we identify genes whose expression during cortical development is regulated by ErbB4, and show that the expression of three of them, CRYM and DBi, depend on ErbB4-JMa whereas WDFY1 relies on ErbB4-JMb. Thus, we provide the first animal model to directly study the roles of ErbB4-JMa and non-canonical ErbB4 signaling in vivo.

Cochlear Neurotrophin-3 overexpression at mid-life prevents age-related inner hair cell synaptopathy and slows age-related hearing loss.

Age-related hearing loss (ARHL) is the most prevalent sensory deficit in the elderly. This progressive pathology often has psychological and medical comorbidities, including social isolation, depression, and cognitive decline. Despite ARHL's enormous societal and economic impact, no therapies to prevent or slow its progression exist. Loss of synapses between inner hair cells (IHCs) and spiral ganglion neurons (SGNs), a.k.a. IHC synaptopathy, is an early event in cochlear aging, preceding neuronal and hair cell loss. To determine if age-related IHC synaptopathy can be prevented, and if this impacts the time-course of ARHL, we tested the effects of cochlear overexpression of neurotrophin-3 (Ntf3) starting at middle age. We chose Ntf3 because this neurotrophin regulates the formation of IHC-SGN synapses in the neonatal period. We now show that triggering Ntf3 overexpression by IHC supporting cells starting in middle age rapidly increases the amplitude of sound-evoked neural potentials compared with age-matched controls, indicating that Ntf3 produces a positive effect on cochlear function when the pathology is minimal. Furthermore, near the end of their lifespan, Ntf3-overexpressing mice have milder ARHL, with larger sound-evoked potentials along the ascending auditory pathway and reduced IHC synaptopathy compared with age-matched controls. Our results also provide evidence that an age-related decrease in cochlear Ntf3 expression contributes to ARHL and that Ntf3 supplementation could serve as a therapeutic for this prevalent disorder. Furthermore, these findings suggest that factors that regulate synaptogenesis during development could prevent age-related synaptopathy in the brain, a process involved in several central nervous system degenerative disorders.

In vitro anti-Leishmania activity of triclabendazole and its synergic effect with amphotericin B.

Introduction: Leishmaniasis is a neglected tropical disease, with approximately 1 million new cases and 30,000 deaths reported every year worldwide. Given the lack of adequate medication for treating leishmaniasis, drug repositioning is essential to save time and money when searching for new therapeutic approaches. This is particularly important given leishmaniasis's status as a neglected disease. Available treatments are still far from being fully effective for treating the different clinical forms of the disease. They are also administered parenterally, making it challenging to ensure complete treatment, and they are extremely toxic, in some cases, causing death. Triclabendazole (TCBZ) is a benzimidazole used to treat fasciolosis in adults and children. It presents a lower toxicity profile than amphotericin B (AmpB) and is administered orally, making it an attractive candidate for treating other parasitoses. The mechanism of action for TCBZ is not yet well understood, although microtubules or polyamines could potentially act as a pharmacological target. TCBZ has already shown antiproliferative activity against T. cruzi, T. brucei, and L. infantum. However, further investigations are still necessary to elucidate the mechanisms of action of TCBZ. Methods: Cytotoxicity assay was performed by MTT assay. Cell inhibition (CI) values were obtained according to the equation CI = (O.D treatment x 100/O.D. negative control). For Infection evaluation, fixated cells were stained with Hoechst and read at Operetta High Content Imaging System (Perkin Elmer). For growth curves, cell culture absorbance was measured daily at 600 nm. For the synergism effect, Fractional Inhibitory Concentrations (FICs) were calculated for the IC50 of the drugs alone or combined. Mitochondrial membrane potential (DYm), cell cycle, and cell death analysis were evaluated by flow cytometry. Reactive oxygen species (ROS) and lipid quantification were also determined by fluorimetry. Treated parasites morphology and ultrastructure were analyzed by electron microscopy. Results: The selectivity index (SI = CC50/IC50) of TCBZ was comparable with AmpB in promastigotes and amastigotes of Leishmania amazonensis. Evaluation of the cell cycle showed an increase of up to 13% of cells concentrated in S and G2, and morphological analysis with scanning electron microscopy showed a high frequency of dividing cells. The ultrastructural analysis demonstrated large cytoplasmic lipid accumulation, which could suggest alterations in lipid metabolism. Combined administration of TCBZ and AmpB demonstrated a synergistic effect in vitro against intracellular amastigote forms with cSFICs of 0.25. Conclusions: Considering that TCBZ has the advantage of being inexpensive and administrated orally, our results suggest that TCBZ, combined with AmpB, is a promising candidate for treating leishmaniasis with reduced toxicity.

Caracterização dos óbitos notificados decorrentes de complicações dos cuidados médicos e cirúrgicos / Characterization of reported deaths resulting from complications of medical and surgical care / Caracterización de las muertes reportadas como resultado de complicaciones de la atención médica y quirúrgica

Objetivo: descrever os casos de óbitos notificados por complicações de assistência médica e cirúrgica no Brasil entre 2015 a 2018. Método: descritivo e retrospectivo conduzido entre junho e julho de 2020 com os registros de óbitos extraídos do Sistema de Informações sobre Mortalidade em Saúde. Os dados foram agrupados em dois biênios 2015-2016 e 2017-2018 e analisados por estatística descritiva e variações percentuais. Resultados: foram notificados 6.587 óbitos, com destaque para o biênio 2017-2018 (n=3.425;52%). Os óbitos ocasionados pelo uso de equipamentos médicos reduziram no Brasil, com variação percentual negativa de 15,4% entre os biênios. Houve aumento das mortes por efeitos adversos de drogas/medicamentos com variação percentual positiva de 12,2%. O número de óbitos por acidentes durante a assistência hospitalar se manteve estacionário. Conclusão: observaram-se alterações nos registros de óbitos notificados no Brasil, e expandir ações preventivas que visem reduzir os óbitos são necessárias em todos os grupos de notificação.

Objective: describing the cases of deaths reported due to complications of medical and surgical care in Brazil between 2015 to 2018. Method: a descriptive and retrospective conducted between June and July 2020 with the records of deaths extracted from the Health Mortality Information System. The data were grouped into two biennia, 2015-2016, and 2017-2018, and analyzed by descriptive statistics and percentage variations. Results: there were reported 6,587 deaths, especially the 2017-2018 biennium (n=3,425;52%). Deaths caused using medical equipment reduced in Brazil, with a negative percentage variation of 15.4% among the biennia. There was an increase in deaths from adverse effects of drugs/medications with a positive percentage variation of 12.2%. The number of deaths from accidents during hospital care remained stationary. Conclusion: changes were observed in the records of deaths notified in Brazil, and expanding preventive actions aimed at reducing deaths are necessary in all notification groups.

Objetivo: describir los casos de muertes reportadas por complicaciones de la atención médica y quirúrgica en Brasil entre 2015 y 2018. Método: descriptivo y retrospectivo realizado entre junio y julio de 2020 con los registros de defunciones extraídos del Sistema de Información de Mortalidad en Salud. Los datos se agruparon en dos bienios 2015-2016 y 2017-2018 y se analizaron mediante estadísticas descriptivas y variaciones porcentuales. Resultados: se reportaron 6.587 muertes, especialmente em el bienio 2017-2018 (n=3.425;52%). Las muertes causadas por el uso de equipo médico se redujeron en Brasil, con una variación porcentual negativa del 15,4% entre los bienios. Hubo un aumento en las muertes por efectos adversos de medicamentos con una variación porcentual positiva de 12.2%. El número de muertes por accidentes durante la atención hospitalaria se mantuvo estacionario. Conclusión: se observaron cambios en los registros de muertes notificadas en Brasil, y es necesario ampliar las acciones preventivas dirigidas a reducir las muertes en todos los grupos de notificación.

Biocompatible gum arabic-gold nanorod composite as an effective therapy for mistreated melanomas.

Advanced melanoma patients that are not included in common genetic classificatory groups lack effective and safe therapeutic options. Chemotherapy and immunotherapy show unsatisfactory results and devastating adverse effects for these called triple wild-type patients. New approaches exploring the intrinsic antitumor properties of gold nanoparticles might reverse this scenario as a safer and more effective alternative. Therefore, we investigated the efficacy and safety of a composite made of gum arabic-functionalized gold nanorods (GA-AuNRs) against triple wild-type melanoma. The natural polymer gum arabic successfully stabilized the nanorods in the biological environment and was essential to improve their biocompatibility. In vivo results obtained from treating triple wild-type melanoma-bearing mice showed that GA-AuNRs remarkably reduced primary tumor growth by 45%. Furthermore, GA-AuNRs induced tumor histological features associated with better prognosis while also reducing superficial lung metastasis depth and the incidence of intrapulmonary metastasis. GA-AuNRs' efficacy comes from their capacity to reduce melanoma cells ability to invade the extracellular matrix and grow into colonies, in addition to a likely immunomodulatory effect induced by gum arabic. Additionally, a broad safety investigation found no evidence of adverse effects after GA-AuNRs treatment. Therefore, this study unprecedentedly reports GA-AuNRs as a potential nanomedicine for advanced triple wild-type melanomas.

STAT3 but Not ERK2 Is a Crucial Mediator Against Diet-Induced Obesity via VMH Neurons.

Leptin plays an important role in the protection against diet-induced obesity (DIO) by its actions in ventromedial hypothalamic (VMH) neurons. However, little is known about the intracellular mechanisms involved in these effects. To assess the role of the STAT3 and ERK2 signaling in neurons that express the steroidogenic factor 1 (SF1) in the VMH in energy homeostasis, we used cre-lox technology to generate male and female mice with specific disruption of STAT3 or ERK2 in SF1 neurons of the VMH. We demonstrated that the conditional knockout of STAT3 in SF1 neurons of the VMH did not affect body weight, food intake, energy expenditure, or glucose homeostasis in animals on regular chow. However, with high-fat diet (HFD) challenge, loss of STAT3 in SF1 neurons caused a significant increase in body weight, food intake, and energy efficiency that was more remarkable in females, which also showed a decrease in energy expenditure. In contrast, deletion of ERK2 in SF1 neurons of VMH did not have any impact on energy homeostasis in both regular diet and HFD conditions. In conclusion, STAT3 but not ERK2 signaling in SF1 neurons of VMH plays a crucial role in protection against DIO in a sex-specific pattern.

Soil CO2 emission and soil attributes associated with the microbiota of a sugarcane area in southern Brazil.

The spatial structure of soil CO2 emission (FCO2) and soil attributes are affected by different factors in a highly complex way. In this context, this study aimed to characterize the spatial variability patterns of FCO2 and soil physical, chemical, and microbiological attributes in a sugarcane field area after reform activities. The study was conducted in an Oxisol with the measurement of FCO2, soil temperature (Ts), and soil moisture (Ms) in a regular 90 × 90-m grid with 100 sampling points. Soil samples were collected at each sampling point at a depth of 0-0.20 m to determine soil physical (density, macroporosity, and microporosity), particle size (sand, silt, and clay), and chemical attributes (soil organic matter, pH, P, K, Ca, Mg, Al, H + Al, cation exchange capacity, and base saturation). Geostatistical analyses were performed to assess the spatial variability and map soil attributes. Two regions (R1 and R2) with contrasting emission values were identified after mapping FCO2. The abundance of bacterial 16S rRNA, pmoA, and nifH genes, determined by real-time quantitative PCR (qPCR), enzymatic activity (dehydrogenase, urease, cellulase, and amylase), and microbial biomass carbon were determined in R1 and R2. The mean values of FCO2 (2.91 µmol m-2 s-1), Ts (22.6 °C), and Ms (16.9%) over the 28-day period were similar to those observed in studies also conducted under Oxisols in sugarcane areas and conventional soil tillage. The spatial pattern of FCO2 was similar to that of macropores, air-filled pore space, silt content, soil organic matter, and soil carbon decay constant. No significant difference was observed between R1 and R2 for the copy number of bacterial 16S rRNA and nifH genes, but the results of qPCR for the pmoA gene presented differences (p < 0.01) between regions. The region R1, with the highest FCO2 (2.9 to 4.2 µmol m-2 s-1), showed higher enzymatic activity of dehydrogenase (33.02 µg TPF g-1 dry soil 24 h-1), urease (41.15 µg NH4-N g-1 dry soil 3 h-1), amylase (73.84 µg glucose g-1 dry soil 24 h-1), and microbial biomass carbon (41.35 µg C g-1 soil) than R2, which had the lowest emission (1.9 to 2.7 µmol m-2 s-1). In addition, the soil C/N ratio was higher in R2 (15.43) than in R1 (12.18). The spatial pattern of FCO2 in R1 and R2 may not be directly related to the total amount of the microbial community (bacterial 16S rRNA) in the soil but to the specific function that these microorganisms play regarding soil carbon degradation (pmoA).

Axon-glia interactions in the ascending auditory system.

The auditory system detects and encodes sound information with high precision to provide a high-fidelity representation of the environment and communication. In mammals, detection occurs in the peripheral sensory organ (the cochlea) containing specialized mechanosensory cells (hair cells) that initiate the conversion of sound-generated vibrations into action potentials in the auditory nerve. Neural activity in the auditory nerve encodes information regarding the intensity and frequency of sound stimuli, which is transmitted to the auditory cortex through the ascending neural pathways. Glial cells are critical for precise control of neural conduction and synaptic transmission throughout the pathway, allowing for the precise detection of the timing, frequency, and intensity of sound signals, including the sub-millisecond temporal fidelity is necessary for tasks such as sound localization, and in humans, for processing complex sounds including speech and music. In this review, we focus on glia and glia-like cells that interact with hair cells and neurons in the ascending auditory pathway and contribute to the development, maintenance, and modulation of neural circuits and transmission in the auditory system. We also discuss the molecular mechanisms of these interactions, their impact on hearing and on auditory dysfunction associated with pathologies of each cell type.

Synergistic effect and ultrastructural changes in Trypanosoma cruzi caused by isoobtusilactone A in short exposure of time.

Butanolides have shown a variety of biological effects including anti-inflammatory, antibacterial, and antiprotozoal effects against certain strains of Trypanosoma cruzi. Considering the lack of an effective drug to treat T. cruzi infections and the prominent results obtained in literature with this class of lactones, we investigated the anti-T. cruzi activity of five butanolides isolated from two species of Lauraceae, Aiouea trinervis and Mezilaurus crassiramea. Initially, the activity of these compounds was evaluated on epimastigote forms of the parasite, after a treatment period of 4 h, followed by testing on amastigotes, trypomastigotes, and mammalian cells. Next, the synergistic effect of active butanolides against amastigotes was evaluated. Further, metacyclogenesis inhibition and infectivity assays were performed for the most active compound, followed by ultrastructural analysis of the treated amastigotes and trypomastigotes. Among the five butanolides studied, majoranolide and isoobtusilactone A were active against all forms of the parasite, with good selectivity indexes in Vero cells. Both butanolides were more active than the control drug against trypomastigote and epimastigote forms and also had a synergic effect on amastigotes. The most active compound, isoobtusilactone A, which showed activity against all tested strains inhibited metacyclogenesis and infection of new host cells. In addition, ultrastructural analysis revealed that this butanolide caused extensive damage to the mitochondria of both amastigotes and trypomastigotes, resulting in severe morphological changes in the infective forms of the parasite. Altogether, our results highlight the potential of butanolides against the etiologic agent of Chagas disease and the relevance of isoobtusilactone A as a strong anti-T. cruzi drug, affecting different events of the life cycle and all evolutionary forms of parasite after a short period of exposure.

Trypanin Disruption Affects the Motility and Infectivity of the Protozoan Trypanosoma cruzi.

The flagellum of Trypanosomatids is an organelle that contributes to multiple functions, including motility, cell division, and host-pathogen interaction. Trypanin was first described in Trypanosoma brucei and is part of the dynein regulatory complex. TbTrypanin knockdown parasites showed motility defects in procyclic forms; however, silencing in bloodstream forms was lethal. Since TbTrypanin mutants show drastic phenotypic changes in mammalian stages, we decided to evaluate if the Trypanosoma cruzi ortholog plays a similar role by using the CRISPR-Cas9 system to generate null mutants. A ribonucleoprotein complex of SaCas9 and sgRNA plus donor oligonucleotide were used to edit both alleles of TcTrypanin without any selectable marker. TcTrypanin -/- epimastigotes showed a lower growth rate, partially detached flagella, normal numbers of nuclei and kinetoplasts, and motility defects such as reduced displacement and speed and increased tumbling propensity. The epimastigote mutant also showed decreased efficiency of in-vitro metacyclogenesis. Mutant parasites were able to complete the entire life cycle in vitro; however, they showed a reduction in their infection capacity compared with WT and addback cultures. Our data show that T. cruzi life cycle stages have differing sensitivities to TcTrypanin deletion. In conclusion, additional work is needed to dissect the motility components of T. cruzi and to identify essential molecules for mammalian stages.

Beyond gold nanoparticles cytotoxicity: Potential to impair metastasis hallmarks.

Gold nanoparticle (AuNP)-based systems have been extensively investigated as diagnostic and therapeutic agents due to their tunable properties and easy surface functionalization. Upon cell uptake, AuNPs present an inherent cell impairment potential based on organelle and macromolecules damage, leading to cell death. Such cytotoxicity is concentration-dependent and completely undesirable, especially if unspecific. However, under non-cytotoxic concentrations, internalized AuNPs could potentially weaken cells and act as antitumor agents. Therefore, this study aimed to investigate the antitumor effect of ultrasmall AuNPs (~3 nm) stabilized by the anionic polysaccharide gum arabic (GA-AuNPs). Other than intrinsic cytotoxicity, the focus was downregulation of cancer hallmarks of aggressive tumors, using a highly metastatic model of melanoma. We first demonstrated that GA-AuNPs showed excellent stability under biological environment. Non-cytotoxic concentrations to seven different cell lines, including tumorigenic and non-tumorigenic cells, were determined by standard 2D in vitro assays. Gold concentrations ≤ 2.4 mg L-1 (16.5 nM AuNPs) were non-cytotoxic and therefore chosen for further analyses. Cells exposed to GA-AuNPs were uptaken by melanoma cells through endocytic processes. Next we described remarkable biological properties using non-cytotoxic concentrations of this nanomaterial. Invasion through an extracellular matrix barrier as well as 3D growth capacity (anchorage-independent colony formation and spheroids growth) were negatively affected by 2.4 mg L-1 GA-AuNPs. Additionally, exposed spheroids showed morphological changes, suggesting that GA-AuNPs could penetrate into the preformed tumor and affect its integrity. All together these results demonstrate that side effects, such as cytotoxicity, can be avoided by choosing the right concentration, nevertheless, preserving desirable effects such as modulation of key tumor cell malignancy features.

A Mathematical Description of the Dynamics of Coronavirus Disease 2019 (COVID-19): A Case Study of Brazil.

This paper deals with the mathematical modeling and numerical simulations related to the coronavirus dynamics. A description is developed based on the framework of the susceptible-exposed-infectious-removed model. Initially, a model verification is carried out calibrating system parameters with data from China, Italy, Iran, and Brazil. Results show the model capability to predict infectious evolution. Afterward, numerical simulations are performed in order to analyze different scenarios of COVID-19 in Brazil. Results show the importance of the governmental and individual actions to control the number and the period of the critical situations related to the pandemic.

Novel findings on the role of ficolins and colectins in the innate response against Leishmania braziliensis.

Leishmania (Viannia) braziliensis is the main agent of mucocutaneous Leishmaniasis, a neglected tropical disease that affects thousands of people in Brazil. It has been shown that complement plays a critical role at early stages of Leishmania infection and that is involved in the invasion of macrophages by the promastigotes. Ficolins and collectins are soluble pattern recognition and triggering molecules of the lectin complement pathway. We investigated here whether lectin pathway activators ficolin-1, ficolin-2, ficolin-3 and CL-11 bind to live L. braziliensis promastigotes in vitro. Promastigote forms in the stationary growth phase were incubated with normal human serum (NHS) or recombinant ficolins 1, 2 and 3, MBL and CL-11, and protein binding was evaluated by confocal microscopy and flow cytometry. Ficolins 1, 2 and 3, MBL and CL-11 were able to bind to the surface of live promastigotes after incubation with either NHS or recombinant proteins. A partial inhibition by N-acetyl-d-glucosamine characterizing the participation of acetylated groups in the deposition of ficolins and CL-11 to glycoconjugates on the surface of L. braziliensis was observed. These evidences highlight a role for the lectin pathway in the innate response to L. braziliensis.

Caracterización de pacientes con enfermedad cerebrovascular isquémica y deterioro cognitivo. Cienfuegos, 2018 / Characterization of patients with ischemic cerebrovascular disease and cognitive impairment. Cienfuegos, 2018

RESUMEN Fundamento: la enfermedad cerebrovascular ocupa el tercer lugar como causa de muerte al ser superada solo por las enfermedades cardiovasculares y el cáncer. Constituye la primera causa de discapacidad permanente en el adulto y la segunda de demencia. Objetivo: caracterizar pacientes con enfermedad cerebrovascular y trastorno cognitivo. Métodos: estudio observacional, descriptivo de corte transversal, realizado en el Servicio de Neurología del Hospital Gustavo Aldereguía Lima de Cienfuegos, que incluyó 27 pacientes hospitalizados en dicho centro, con deterioro cognitivo, después del primer evento de enfermedad cerebrovascular isquémica. Se analizaron las variables: sexo, edad, color de piel, escolaridad, ocupación, estado civil, procedencia, hábitos tóxicos, antecedentes patológicos personales, tipo de enfermedad cerebrovascular, estructura encefálica afectada, deterioro cognitivo (mediante el test mínimo del estado mental de Folstein y el test Montreal cognitive assessment), alteraciones neuropsicológicas, depresión (mediante la escala de depresión geriátrica de Yessavage). Resultados: predominaron los adultos mayores, el sexo masculino y color de piel blanca, así como bajo grado de escolaridad y los solteros. El evento isquémico aterotrombótico fue el más observado y el hemisferio derecho el más afectado. Hubo deterioro cognitivo en todos los pacientes. Los factores de riesgo mayormente asociados a la enfermedad fueron la hipertensión arterial, diabetes mellitus y tabaquismo. La mayoría de los pacientes no sufrió depresión posterior al infarto cerebral. Conclusiones: los adultos mayores, solteros son más propensos a sufrir accidentes cerebrovasculares. El bajo nivel educacional puede ser un factor asociado al deterioro cognitivo posterior a esta enfermedad, no así la depresión que no siempre se manifiesta de manera profunda.

ABSTRACT Foundation: cerebrovascular disease occupies the third place as a cause of death to be overcome only by cardiovascular diseases and cancer. It constitutes the first cause of permanent disability in the adult and the second of dementia. Objective: to characterize patients with cerebrovascular disease and cognitive disorder. Methods: an observational, descriptive, cross-sectional study, carried out in the Neurology Service of the Gustavo Aldereguía Lima Hospital in Cienfuegos, which included 27 patients hospitalized in this center, with cognitive impairment, after the first event of ischemic cerebrovascular disease. The variables were analyzed: sex, age, skin color, schooling, occupation, marital status, origin, toxic habits, personal pathological history, type of cerebrovascular disease, affected brain structure, cognitive impairment (using the minimum Folstein mental state test and the Montreal cognitive assessment test), neuropsychological alterations, depression (using the Yessavage geriatric depression scale). Results: Elderly adults, male sex and white skin color predominated, as well as low level of schooling and singles. The atherothrombotic ischemic event was the most common and the right hemisphere the most affected. There was cognitive impairment in all patients. The risk factors mostly associated with the disease were high blood pressure, diabetes mellitus and smoking. The majority of patients did not suffer depression after cerebral infarction. Conclusions: older, single adults are more likely to suffer strokes. The low educational level may be a factor associated to cognitive impairment after this disease, but depression that does not always manifests deeply.

Microbial N-cycling gene abundance is affected by cover crop specie and development stage in an integrated cropping system.

Grasses of the Urochloa genus have been widely used in crop-livestock integration systems or as cover crops in no-till systems such as in rotation with maize. Some species of Urochloa have mechanisms to reduce nitrification. However, the responses of microbial functions in crop-rotation systems with grasses and its consequence on soil N dynamics are not well-understood. In this study, the soil nitrification potential and the abundance of ammonifying microorganisms, total bacteria and total archaea (16S rRNA gene), nitrogen-fixing bacteria (NFB, nifH), ammonia-oxidizing bacteria (AOB, amoA) and archaea (AOA, amoA) were assessed in soil cultivated with ruzigrass (Urochloa ruziziensis), palisade grass (Urochloa brizantha) and Guinea grass (Panicum maximum). The abundance of ammonifying microorganisms was not affected by ruzigrass. Ruzigrass increased the soil nitrification potential compared with palisade and Guinea grass. Ruzigrass increased the abundance of N-fixing microorganisms at the middle and late growth stages. The abundances of nitrifying microorganisms and N-fixers in soil were positively correlated with the soil N-NH4+ content. Thus, biological nitrogen fixation might be an important input of N in systems of rotational production of maize with forage grasses. The abundance of microorganisms related to ammonification, nitrification and nitrogen fixing and ammonia-oxidizing archea was related to the development stage of the forage grass.