Bacterial community of ticks (Acari: Ixodidae) and mammals from Arauca, Colombian Orinoquia.

Ticks are obligate hematophagous ectoparasites of vertebrates and are relevant worldwide due to the number of bacterial and other pathogens they can transmit. To date, the knowledge about the microorganisms that ticks harbor and transmit to their hosts is incipient. In this study, 24 samples of mammals belonging to four taxonomic orders and ticks of the genera Amblyomma and Rhipicephalus from the Orinoco region of Colombia were analyzed to described and compare the bacterial microbiome. Genetic extraction was performed, and the V3-V4 region of the 16S rRNA gene was amplified by PCR. Libraries were created, and those samples with adequate quality indices were sequenced using Illumina MiSeq technology. Bacterial taxonomic assignment analyses were conducted through Amplicon Sequence Variants (ASVs) and Operational Taxonomic Units (OTUs). The results correspond to 16 samples that passed the quality filters, with 3218 OTUs (415 families). Although a considerable number of unknown bacteria was found, Enterobacteriaceae, Beijerinckiaceae, Moraxellaceae, and Burkholderiaceae are the most prevalent families, and the presence of the genera Coxiella, Escherichia-Shigella, Enterobacter, which can harbor pathogenic species was confirmed. In individuals of Amblyomma mixtum found actively feeding on Hydrochoerus hydrochaeris, bacteria of the genera Escherichia-Shigella and Enterobacter were documented. Similarly, Rhipicephalus microplus found actively feeding on Odocoileus virginianus cariacou shared Escherichia-Shigella. Ralstonia was shared among the blood samples of H. hydrochaeris, while Anaplasma and Eubacterium were shared in blood and liver samples of O. v. cariacou. Shared bacteria between A. mixtum and R. microplus included Bacillus, Coxiella, and Escherichia-Shigella. The results highlight the need of additional studies in other natural regions of Colombia and other American countries where tick-borne diseases have been detected. Likewise, the recorded data are the first at the level of bacterial communities in ticks of the family Ixodidae and provide valuable knowledge for the understanding host-tick and pathogen interactions.

Emerging concepts on the FGF23 regulation and activity.

Fibroblast growth factor 23 (FGF23) discovery has provided new insights into the regulation of Pi and Ca homeostasis. It is secreted by osteoblasts and osteocytes, and acts mainly in the kidney, parathyroid, heart, and bone. The aim of this review is to highlight the current knowledge on the factors modulating the synthesis of FGF23, the canonical and non-canonical signaling pathways of the hormone, the role of FGF23 in different pathophysiological conditions, and the anti-FGF23 therapy. This is a narrative review based on the search of PubMed database in the range of years 2000-2023 using the keywords local and systemic regulators of FGF23 synthesis, FGF23 receptors, canonical and non-canonical pathways, pathophysiological conditions and FGF23, and anti-FGF23 therapy, focusing the data on the molecular mechanisms. The regulation of FGF23 synthesis is complex and multifactorial. It is regulated by local factors and systemic regulators mainly involved in bone mineralization. The excessive FGF23 production is associated with different congenital diseases and with diseases occurring with a secondary high FGF23 production such as in chronic disease kidney and tumor-induced osteomalacia (TIO). The anti-FGF23 therapy appears to be useful to treat chromosome X-linked hypophosphatemia and TIO, but there are doubts about the handle of excessive FGF23 production in CKD. FGF23 biochemistry and pathophysiology are generating a plethora of knowledge to reduce FGF23 bioactivity at many levels that might be useful for future therapeutics of diseases associated with high-serum FGF23 levels.

Methylmercury neurotoxicity: Beyond the neurocentric view.

Mercury is a highly toxic metal widely used in human activities worldwide, therefore considered a global public health problem. Many cases of mercury intoxication have occurred in history and represent a huge challenge nowadays. Of particular importance is its methylated form, methylmercury (MeHg). This mercurial species induces damage to several organs in the human body, especially to the central nervous system. Neurological impairments such as executive, memory, motor and visual deficits are associated with MeHg neurotoxicity. Molecular mechanisms involved in MeHg-induced neurotoxicity include excitotoxicity due to glutamatergic imbalance, disturbance in calcium homeostasis and oxidative balance, failure in synaptic support, and inflammatory response. Although neurons are largely affected by MeHg intoxication, they only represent half of the brain cells. Glial cells represent roughly 50 % of the brain cells and are key elements in the functioning of the central nervous system. Particularly, astrocytes and microglia are deeply involved in MeHg-induced neurotoxicity, resulting in distinct neurological outcomes depending on the context. In this review, we discuss the main findings on astroglial and microglial involvement as mediators of neuroprotective and neurotoxic responses to MeHg intoxication. The literature shows that these responses depend on chemical and morphophysiological features, thus, we present some insights for future investigations, considering the particularities of the context, including time and dose of exposure, brain region, and species of study.

Revisiting Genetic Influence on Mercury Exposure and Intoxication in Humans: A Scoping Review.

Human intoxication to mercury is a worldwide health problem. In addition to the type and length of exposure, the genetic background plays an important role in mercury poisoning. However, reviews on the genetic influence in mercury toxicity are scarce and not systematic. Therefore, this review aimed to systematically overview the most recent evidence on the genetic influence (using single nucleotide polymorphisms, SNPs) on human mercury poisoning. Three different databases (PubMed/Medline, Web of Science and Scopus) were searched, and 380 studies were found that were published from 2015 to 2022. After applying inclusion/exclusion criteria, 29 studies were selected and data on characteristics (year, country, profile of participants) and results (mercury biomarkers and quantitation, SNPs, main findings) were extracted and analyzed. The largest number of studies was performed in Brazil, mainly involving traditional populations of the Tapajós River basin. Most studies evaluated the influence of the SNPs related to genes of the glutathione system (GST, GPx, etc.), the ATP-binding cassette transporters and the metallothionein proteins. The recent findings regarding other SNPs, such as those of apolipoprotein E and brain-derived neurotrophic factor genes, are also highlighted. The importance of the exposure level is discussed considering the possible biphasic behavior of the genetic modulation phenomena that could explain some SNP associations. Overall, recommendations are provided for future studies based on the analysis obtained in this scoping review.

[Procalcitonin as sepsis predictor in cardiovascular surgery with cardiopulmonary bypass]. / Procalcitonina como predictor de sepsis en cirugía cardiovascular con circulación extracorpórea.

Background: Cardiopulmonary bypass generates an exacerbated response that may lead to sepsis. Objective: To describe the association between procalcitonin levels and sepsis diagnosis in cardiovascular surgery subjects with cardiopulmonary bypass. Methods: A case-series study was conducted in 142 patients. Serum procalcitonin levels were measured at 24 hours and at 72 hours after surgery using a point of care testing based on quantitative immunochromatographic method. To assess association between procalcitonin levels and sepsis status, we calculated area under the curve (AUC) and sensitivity, specificity, and predictive values for the best cut-off point. Results: From 142 patients studied, 7 developed sepsis after surgery (4.9%). For 24-hours procalcitonin levels AUC was 0.921 and best cut-off point was 3.8 ng/mL (sensitivity 0.857 and specificity 0.904). In the case of 72-hours procalcitonin levels, we observed a value of 0.868 for AUC and best cut-off point was 8.4 ng/mL (sensitivity 0.86 and specificity 0.97). Conclusions: Procalcitonin levels at 24 and 72 hours after cardiovascular surgery with cardiopulmonary bypass are associated with sepsis presence at cut-off points of 3.8 and 8.4 ng/mL respectively.

Introducción: la circulación extracorpórea durante la cirugía cardiovascular genera una respuesta exacerbada que puede asociarse con sepsis. Objetivo: describir la asociación entre los niveles de procalcitonina y el diagnóstico de sepsis en sujetos de cirugía cardiovascular con circulación extracorpórea. Material y métodos: se realizó un estudio de serie de casos en 142 pacientes. Los niveles de procalcitonina fueron medidos a las 24 horas y a las 72 horas después de la cirugía. Para evaluar la asociación entre los niveles de procalcitonina y la identificación de sepsis, se calculó el área bajo la curva (AUC) y la sensibilidad y especificidad identificando el mejor punto de corte. Resultados: de un total de 142 pacientes estudiados, 7 desarrollaron sepsis (4.9%). En los niveles de procalcitonina en las 24 horas, el AUC fue de 0.921 y el mejor punto de corte fue 3.8 ng/mL (sensibilidad de 0.857 y especificidad de 0.904). En el caso de los niveles de procalcitonina a las 72 horas, observamos un AUC de 0.868 y el mejor punto de corte fue 8.4 ng/mL (sensibilidad de 0.86 y especificidad de 0.97). Conclusiones: los niveles de procalcitonina a las 24 y 72 horas de la cirugía cardiovascular con circulación extracorpórea se asociaron con la presencia de sepsis con los puntos de corte de 3.8 ng/mL y 8.4 ng/mL respectivamente.

What We Know about Euterpe Genus and Neuroprotection: A Scoping Review.

The Euterpe genus (mainly Euterpe oleracea Martius, Euterpe precatoria Martius, and Euterpe edulis Martius) has recently gained commercial and scientific notoriety due to the high nutritional value of its fruits, which are rich in polyphenols (phenolic acids and anthocyanins) and have potent antioxidant activity. These characteristics have contributed to the increased number of neuropharmacological evaluations of the three species over the last 10 years, especially açaí of the species Euterpe oleracea Martius. The fruits of the three species exert neuroprotective effects through the modulation of inflammatory and oxidative pathways and other mechanisms, including the inhibition of the mTOR pathway and protection of the blood-brain barrier, all of them intimately involved in several neuropathologies. Thus, a better understanding of the neuropharmacological properties of these three species may open new paths for the development of therapeutic tools aimed at preventing and treating a variety of neurological conditions.

Maternal methylmercury exposure during early-life periods adversely affects mature enamel structure of offspring rats at human exposure levels: a concern for oral health.

Although there are many studies on the health effects of methylmercury (MeHg) toxicity during in utero and early development, little is known about its effects on mineralized tissues present in the oral cavity, such as enamel structure. Therefore, this study evaluated the effects of MeHg exposure on the physico-chemical, ultrastructural and functional properties of mature tooth enamel. Specifically, we studied offspring of mothers exposed to MeHg during the prenatal and postnatal periods which are the developmental stages associated with tooth enamel formation. Female rats were exposed to MeHg at a dose of 40 µg/kg/day for 42 days of pregnancy and lactation. The enamel of offspring was analyzed by (1) Fourier Transform Infrared Spectroscopy and Raman to assess physicochemical composition, (2) Scanning Electron Microscopy for ultrastructural evaluation, (3) Transmitted Polarizing Light Microscopy for analysis of the enamel extracellular matrix, and (4) resistance and hardness were evaluated by microhardness. The results showed that MeHg exposure during this sensitive enamel formation period induced changes in inorganic and organic content and enamel prisms ultrastructure alterations and disturbed the organic extracellular matrix due to a decreased enamel strength. These novel findings establish for the first time that maternal exposure to MeHg pre and postnatal promoted relevant changes in mature enamel of their offspring rats.

Exercise Reshapes the Brain: Molecular, Cellular, and Structural Changes Associated with Cognitive Improvements.

Physical exercise is well known as a non-pharmacological and holistic therapy believed to prevent and mitigate numerous neurological conditions and alleviate ageing-related cognitive decline. To do so, exercise affects the central nervous system (CNS) at different levels. It changes brain physiology and structure, promoting cognitive improvements, which ultimately improves quality of life. Most of these effects are mediated by neurotrophins release, enhanced adult hippocampal neurogenesis, attenuation of neuroinflammation, modulation of cerebral blood flow, and structural reorganisation, besides to promote social interaction with beneficial cognitive outcomes. In this review, we discuss, based on experimental and human research, how exercise impacts the brain structure and function and how these changes contribute to cognitive improvements. Understanding the mechanisms by which exercise affects the brain is essential to understand the brain plasticity following exercise, guiding therapeutic approaches to improve the quality of life, especially in obesity, ageing, neurodegenerative disorders, and following traumatic brain injury.

Hair mercury is associated with dyslipidemia and cardiovascular risk: An anthropometric, biochemical and genetic cross-sectional study of Amazonian vulnerable populations.

This cross-sectional study evaluated the association between human exposure to mercury and cardiovascular risk using lipid profile (including apolipoproteins) and genetic analysis of Amazonian riverine population. Anthropometric data (gender, age, height, weight, blood pressure, and neck and waist circumferences) of the participants were recorded. Total mercury and methylmercury (MeHg) content were quantified in hair by ICP-MS and GC-pyro-AFS system. Polymorphisms rs662799, rs693, rs429358 and rs7412 (of genes of apolipoproteins A-V, B, and E at positions 112 and 158, respectively) were genotyped by real-time PCR. The population presented a dyslipidemia profile significantly correlated with high mercury levels. The apolipoprotein B/apolipoprotein A-I (ApoB/ApoA-I) index was also positively correlated with mercury, supporting a possible causal relationship. Allelic distributions were similar to those described in other populations, suggesting that genetic susceptibility may not have a significant role in the lipid alterations found in this work. This study demonstrated for the first time: i) the relationship between mercury exposure and cardiovascular risk-related apolipoproteins in humans, ii) the ApoB levels and the ApoB/ApoA-I index as the risk factors more strongly associated to the mercury-related dyslipidemia in humans, and iii) the prevalence of high/moderate risk of acute myocardial infarction in the vulnerable and chronically exposed-populations of the Amazon, in addition to the genotypic profile of the three most frequent polymorphisms in apolipoproteins of relevance for cardiovascular risk. This early detection of lipid alterations is essential to prevent the development of cardiovascular diseases (CVD), especially in chronically exposed populations such as those found in the Amazon. Therefore, in addition to provide data for the Minamata Convention implementation, our work is in line with the efforts joined by all members of the World Health Organization committed to reducing premature deaths originating from non-communicable diseases by 25% in 2025, including CVD.

Mercury in the Amazon: The danger of a single story.

Amazon conservation is essential for the global future. Mercury is currently among the worst global pollutants and most (78.5%) of the South-American emissions are from the Amazon. Current Brazilian legislation on mining activities and trade of gold, and economic interests in soy, beef and large-scale projects such as dams, are key influences in mercury mobilization and emissions in the Amazon with the potential to affect the global environment. However, banning mercury in mining, while desirable, is not an efficient strategy if no other action is taken. The interconnected issues, such as exports (soy, beef and gold) and energy generation, must be addressed together to provide effective protection for human health and the environment. Realistically, to improve mercury emissions in the Amazon, we must stop looking solely at "the single story" (a limited view of reality) of supposedly "artisanal and small-scale gold mining" in the region and understand the complex economic, social, political, and international aspects of this problem. We propose some recommendations for international agencies, governments, communities and the private sector.

La evaluación en el posgrado mediante la educación a distancia durante la COVID-19 / Postgraduate evaluation through distance learning during COVID-19

Fundamento: La implementación de la educación a distancia en el posgrado durante la COVID-19 constituye una alternativa del sistema de educación superior cubana. Objetivo: Describir los resultados de la evaluación en el posgrado, mediante la modalidad de educación a distancia durante el tercer rebrote de la pandemia de COVID-19. Metodología: Se realizó un estudio observacional descriptivo transversal entre junio y julio de 2021, en la Facultad de Estomatología de la Universidad de Ciencias Médicas de Santiago de Cuba. Se consideraron como unidades de análisis: unidades didácticas, estudiantes (residentes), la población estuvo constituida por los 146 residentes que cursaban el 1.er año de la especialidad, se seleccionó una muestra aleatoria (n= 96). Se estudiaron las variables resultados de las evaluaciones de cada unidad didáctica y general del módulo (excelente, bien, regular y mal), grado de dificultad (muy difícil, difícil y sin dificultad) y nivel de satisfacción (satisfecho, medianamente satisfecho e insatisfecho). Como instrumento de medición se empleó el registro de evaluación y de entrevista, respectivamente. Se empleó el porcentaje como medida de resumen. Resultados: Más del 70 % de los residentes evaluados se encontró en la categoría de bien sin dificultad, estando satisfechos con la modalidad de educación a distancia. Conclusiones: Predominaron los resultados de "excelente" solo en la unidad didáctica 1 y de "bien" en la evaluación final del módulo. La unidad didáctica de "mayor dificultad" resultó ser la 2. La mayor cantidad de residentes refirió estar satisfecho con la modalidad de educación a distancia en el posgrado.

Background: The implementation of distance education at the postgraduate level during COVID-19 represents an alternative in the Cuban higher education system. Objective: To describe the results of the evaluation in posgrado, through the educational modality at distance during the third regrowth of the pandemic of COVID-19. Methodology: A cross-sectional descriptive observational study was conducted between June and July 2021 at the Faculty of Stomatology, University of Medical Sciences of Santiago de Cuba. The following units of analysis were considered: teaching units, students (residents), the population consisted of 146 residents in the first year of specialization, a random sample was selected (n= 96). The variables studied were the results of the evaluations of each didactic unit and the general evaluation of the module (excellent, good, fair, and poor), level of difficulty (very difficult, difficult, and no difficulty), and level of satisfaction (satisfied, moderately satisfied, and dissatisfied). The evaluation and interview registers were used as measurement instruments, respectively, and the percentage was used as a summary measure. Results: More than 70% of the residents evaluated were in the good without difficulty category and were satisfied with the distance learning modality. Conclusions: The results "excellent" predominated only in didactic unit 1 and "good" in the final evaluation of the module. The "most difficult" didactic unit was didactic unit 2. Most residents were satisfied with the distance learning modality in the postgraduate program.

Global Human Threat: The Potential Synergism between Mercury Intoxication and COVID-19.

The COVID-19 pandemic affected billions of people worldwide, and exposure to toxic metals has emerged as an important risk factor for COVID-19 severity. Mercury is currently ranked as the third toxic substance of global concern for human health, and its emissions to the atmosphere have increased globally. Both COVID-19 and mercury exposure present a high prevalence in similar regions: East and Southeast Asia, South America and Sub-Saharan Africa. Since both factors represent a multiorgan threat, a possible synergism could be exacerbating health injuries. Here, we discuss key aspects in mercury intoxication and SARS-CoV-2 infection, describing the similarities shared in clinical manifestations (especially neurological and cardiovascular outcomes), molecular mechanisms (with a hypothesis in the renin-angiotensin system) and genetic susceptibility (mainly by apolipoprotein E, paraoxonase 1 and glutathione family genes). Literature gaps on epidemiological data are also highlighted, considering the coincident prevalence. Furthermore, based on the most recent evidence, we justify and propose a case study of the vulnerable populations of the Brazilian Amazon. An understanding of the possible adverse synergism between these two factors is crucial and urgent for developing future strategies for reducing disparities between developed and underdeveloped/developing countries and the proper management of their vulnerable populations, particularly considering the long-term sequelae of COVID-19.

Neurotoxicity and the Global Worst Pollutants: Astroglial Involvement in Arsenic, Lead, and Mercury Intoxication.

Environmental pollution is a global threat and represents a strong risk factor for human health. It is estimated that pollution causes about 9 million premature deaths every year. Pollutants that can cross the blood-brain barrier and reach the central nervous system are of special concern, because of their potential to cause neurological and development disorders. Arsenic, lead and mercury are usually ranked as the top three in priority lists of regulatory agencies. Against xenobiotics, astrocytes are recognised as the first line of defence in the CNS, being involved in virtually all brain functions, contributing to homeostasis maintenance. Here, we discuss the current knowledge on the astroglial involvement in the neurotoxicity induced by these pollutants. Beginning by the main toxicokinetic characteristics, this review also highlights the several astrocytic mechanisms affected by these pollutants, involving redox system, neurotransmitter and glucose metabolism, and cytokine production/release, among others. Understanding how these alterations lead to neurological disturbances (including impaired memory, deficits in executive functions, and motor and visual disfunctions), by revisiting the current knowledge is essential for future research and development of therapies and prevention strategies.

Prácticas socioformativas para la gestión de competencias investigativas en el médico general integral utilizando Telegram / Socioformative practices for the management of investigative skills in the comprehensive general practitioner using Telegram

Fundamento: las tecnologías de la información y las comunicaciones ofrecen herramientas que facilitan la formación de competencias investigativas en los médicos generales integrales con la utilización de Telegram en el contexto de la sociedad del conocimiento. Objetivo: valorar la efectividad en la transformación de la práctica socioformativa para la gestión de las competencias investigativas en el médico general integral, haciendo uso de Telegram en el curso de Metodología de la Investigación durante el periodo septiembre 2021-2022. Métodos: se realizó un estudio cuasiexperimental, en la Filial de Ciencias Médicas "Julio Trigo López" de Palma Soriano. Se utilizaron métodos teóricos: histórico-lógico, análisis-síntesis, enfoque de sistema, abstracción-concreción y el hermenéutico-dialéctico; empíricos: análisis documental, observación, cuestionario y el criterio de expertos. Resultados: se alcanzó mayor eficiencia en la transformación de la práctica socioformativa para la gestión de las competencias investigativas en el médico general integral, haciendo uso de Telegram en los aspectos relacionados con la realización de tareas grupales, interacción promotora y conocimientos sobre cómo confeccionar el proyecto de investigación para la solución de los problemas en la comunidad. Conclusiones: se valora como factible y novedosa la transformación de la práctica socioformativa para la gestión de las competencias investigativas en el médico general integral, haciendo uso de Telegram como herramienta para el aprendizaje colaborativo como protagonista en este entorno virtual de interacción.

Background: information and communication technologies offer tools that facilitate the formation of investigative skills in comprehensive general practitioners in the context of the knowledge society. Objective: to assess the effectiveness in the transformation of the socioformative practice for the management of investigative skills in the comprehensive general practitioner, using Telegram in the Research Methodology course during the period September 2021-2022. Methods: a quasi-experimental study was carried out at the "Julio Trigo López" Medical Sciences Branch in Palma Soriano. Theoretical methods were used: historical-logical, analysis-synthesis, system approach, abstraction-concretion and hermeneutic-dialectical; Empirical: documentary analysis, observation, questionnaire and expert criteria. Results: greater efficiency was achieved in the transformation of the socio-formative practice for the management of investigative skills in the comprehensive general practitioner, making use of Telegram in aspects related to carrying out group tasks, promoting interaction and knowledge on how to prepare the project. Research to solve problems in the community. Conclusions: the transformation of the socio-formative practice for the management of investigative skills in the comprehensive general practitioner is valued as feasible and novel, making use of Telegram as a tool for collaborative learning as a protagonist in this virtual environment of interaction.

Caffeine intoxication: Behavioral and electrocorticographic patterns in Wistar rats.

Caffeine is a psychoactive substance used worldwide. The present study analyzes the seizure-related behavior and electrocorticographic (ECoG) patterns observed in rats following of a toxic dose of caffeine (150 mg/kg; intraperitoneal). Sixty-three rats were divided into three experiments: 1-Behavior's Description associated with caffeine-induced convulsion; 2- Comparison of the electrocorticographic patterns induced by caffeine and pentylenetetrazole, and 3- Assessment of the electrocorticographic response to antiepileptic drugs (diazepam, phenytoin, and phenobarbital). The behavioral analysis demonstrated tonic-clonic seizures with a loss of postural reflex and a latency of 365.8 s after the caffeine's administration. Caffeine-induced changes in the ECoG were consistent with the development of seizures with rapid evolution and burst potential consistent with the behavioral patterns observed during the caffeine-induced seizure. The ECoG of the brainwaves varied significantly between the seizures caused by caffeine and pentylenetetrazole. The predominant brain forces observed during the seizures were beta-band oscillations. The caffeine-induced seizures were resistant to attempted control with phenytoin and phenobarbital, but responded well to diazepam, which is consistent with a study of Pilocarpine, which showed that diazepam has anticonvulsant effects. These findings are important for the development of effective treatments for caffeine intoxication, in particular for individuals with a low seizure threshold.

Are Dental Caries Associated with Oxidative Stress in Saliva in Children and Adolescents? A Systematic Review.

This systematic review aimed to assess whether dental caries is associated with oxidative salivary stress. The searches were carried out in electronic databases, including PubMed, Scopus, Web of Science, the Cochrane Library, LILACS, OpenGrey, and Google Scholar, without restrictions on the date of publication and language. The acronym PECO was used, in which the participants (P) were children and adolescents exposed (E) to dental caries compared (C) to those without dental caries, with the outcome (O) of modulation of oxidative biochemical parameters. After the search retrieval, the duplicates were removed, and the articles were evaluated by title and abstract, following the inclusion and exclusion criteria. Then, the papers were read and thoroughly assessed. After selection, the risk of bias assessment and qualitative synthesis were performed using the Newcastle-Ottawa Scale (NOS) for observational studies. The Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) tool was used to assess the level of evidence. A total of 5790 studies were found, and 30 articles were considered eligible and were included for the qualitative synthesis and the level of evidence assessment. The studies showed an imbalance of the antioxidant and pro-oxidant parameters in individuals with dental caries, with primarily increases in both total antioxidant capacity and lipid peroxidation. Most articles showed a low risk of bias, having comparability as the main issue. When exploring through GRADE, a very low level of evidence was found. It was possible to observe an association between oxidative stress and dental caries, showing a disbalance of antioxidants and pro-oxidants, but the evidence level was still very low.

Deciphering the Global Proteomic Profile Involved in Methylmercury-Induced Cerebellar Neurodegeneration and Motor Dysfunction in Adult Rats.

Mercury is a ubiquitous pollutant in the environment with potential neurotoxic effects. Several populations are susceptible to mercurial exposure, especially methylmercury (MeHg) at low doses for long periods through food consumption. Given this, the present work aimed to assess the effects of long-term MeHg exposure on the cerebellum of rats from a translational perspective using a representative dose, assessing molecular, biochemical, morphological, and behavioral parameters. The model was produced by administering 40 µg/kg of MeHg for 60 days to adult male Wistar rats by oral gavage. As a result of this exposure, the animals presented motor deficits in open field and rotarod tests which were associated with an increase in total mercury content in cerebellar parenchyma, a reduction in antioxidant competence against peroxyl radicals, and increased nitrite and lipid peroxidation levels. The proteomic approach showed 317 modulated proteins. Such findings were associated with reductions in mature neuron and Purkinje cell densities and glial fibrillary acidic protein immunostained areas and increased microglial density. In addition, decreases in myelin basic protein and synaptophysin immunostaining were also observed. The results thus provided new evidence of the mechanisms underlying complex MeHg-induced neurodegeneration, especially the proteins underlying the biochemical and morphological features associated with motor dysfunction.

In utero and lactational exposure to methylmercury elicits physical-chemical and morphological damages in the alveolar bone of offspring rats: The first toxicological findings.

Methylmercury (MeHg) is the most common organic form of mercury (Hg) that humans are exposed and is considered an environmental pollutant. Several populations that live in endemic regions of MeHg exposure are subject to the toxicant for long periods, including pregnant women and children, causing damage to several organs during early periods of development. Alveolar bone is an essential structure for the oral cavity, responsible for supporting teeth and masticatory forces. However, evidence on the effects of MeHg on alveolar bone and the intrauterine and lactation period is lacking. Thus, this study aimed to investigate the effects of MeHg exposure during gestation and lactation on the developing alveolar bone of offspring rats after maternal exposure. Dams were exposed during 41 days of pregnancy and lactation, and the mandibles of the offspring were collected. The alveolar bone was analyzed by Fourier Transform Infrared Spectroscopy to evaluate the physicochemical composition; by Scanning Electron Microscopy for ultrastructural evaluation; by histopathological, histochemical, and morphometric for tissue analyses. In addition, bone quality was assessed by X-ray microtomography. MeHg exposure altered the mineral composition and caused histological damage associated with a lower quantity and thickness of bone trabeculae, as well as reduced osteocyte density and collagen fiber content. A reduction in trabecular thickness and bone volume and an increase in trabecular spaces were observed and were associated with anatomical compromise of the vertical bone dimensions. Thus, the results suggest that the developing alveolar bone is susceptible to the toxic effects of MeHg when organisms are exposed during intrauterine and lactation periods. From a translational perspective, these changes in the alveolar bone can help us understand possible abnormalities induced by toxic metals and highlight the need for care for structures other than those already seen as targets for damage triggered by environmental MeHg exposure.

Toxicogenomics and Molecular Markers in Pollution.

Pollution is defined as the presence in or introduction of a substance into the environment that has harmful or poisonous effects [...].

The GABAergic System and Endocannabinoids in Epilepsy and Seizures: What Can We Expect from Plant Oils?

Seizures and epilepsy are some of the most common serious neurological disorders, with approximately 80% of patients living in developing/underdeveloped countries. However, about one in three patients do not respond to currently available pharmacological treatments, indicating the need for research into new anticonvulsant drugs (ACDs). The GABAergic system is the main inhibitory system of the brain and has a central role in seizures and the screening of new ACD candidates. It has been demonstrated that the action of agents on endocannabinoid receptors modulates the balance between excitatory and inhibitory neurotransmitters; however, studies on the anticonvulsant properties of endocannabinoids from plant oils are relatively scarce. The Amazon region is an important source of plant oils that can be used for the synthesis of new fatty acid amides, which are compounds analogous to endocannabinoids. The synthesis of such compounds represents an important approach for the development of new anticonvulsant therapies.