Publications by authors named "Igor Duarte"

Conditioned fear is a response to contexts or cues previously paired with aversive stimuli. Substances from the herb Cannabis sativa (phytocannabinoids), such as cannabidiol (CBD), prevent fear responses and hold potential as new treatments for certain psychiatric disorders, such as post-traumatic stress disorder. The phytocannabinoid cannabigerol (CBG), similarly to CBD, lacks psychotomimetic effects and targets multiple receptors involved in fear-related pathways.

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Objective: We aim to create a web-based calculator for assessing depressive symptoms with the Patient Health Questionnaire 9 (PHQ-9), utilizing IRT-based standardized scores, to improve measurement precision, standardization, and practical application in clinical practice.

Methods: This study developed a web-based calculator using a graded response IRT model for assessing depressive symptoms with the PHQ-9, using data from the Brazilian National Health Survey 2019 (n = 90,846, aged 15 to 107 years old, 52.8% female).

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Article Synopsis
  • * Researchers analyzed data from 2,511 children and adolescents in Brazil, comparing ADHD biomarkers like polygenic scores, subcortical volumes, and executive function among different risk groups.
  • * Findings showed that a risk-informed approach significantly highlighted differences in biomarkers, suggesting this method could improve evaluations for ADHD and potentially other mental disorders.
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Noradrenaline (NA) and serotonin (5-HT) induce nociception and antinociception. This antagonistic effect can be explained by the dose and type of activated receptors. We investigated the existence of synergism between the noradrenergic and serotonergic systems during peripheral antinociception.

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Aquatic apicomplexans called Corallicolida have been found in tropical and coral-reef settings, infecting many coral species. New data challenge this tropical distribution and expand the corallicolids' range well into the cold temperate. Surprisingly, the sister clade to corallicolids infects only one group of vertebrates - bony fishes.

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The present study aimed to evaluate the possible peripheral HO-induced antinociception and determine the involvement of opioidergic, cannabinoidergic and nitrergic systems, besides potassium channels in its antinociceptive effect. Prostaglandin E was used to induce hyperalgesia in male Swiss mice using the mechanical paw pressure test. HO (0.

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Introduction: Tissue injury results in the release of inflammatory mediators, including a cascade of algogenic substances, which contribute to the development of hyperalgesia. During this process, endogenous analgesic substances are peripherally released to counterbalance hyperalgesia. The present study aimed to investigate whether inflammatory mediators TNF-α, IL-1β, CXCL1, norepinephrine (NE), and prostaglandin E2 (PGE2) may be involved in the deflagration of peripheral endogenous modulation of inflammatory pain by activation of the cholinergic system.

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Background: Cannabidiol (CBD) is the second most abundant pharmacologically active component present in Cannabis sp. Unlike Δ-9-tetrahydrocannabinol (THC), it has no psychotomimetic effects and has recently received significant interest from the scientific community due to its potential to treat anxiety and epilepsy. CBD has excellent anti-inflammatory potential and can be used to treat some types of inflammatory and neuropathic pain.

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Objective: To evaluate the prevalence of attention-deficit/hyperactivity disorder (ADHD), comorbidity rates with disruptive behavior disorders and main negative outcomes in primary school students in Nampula, Mozambique.

Methods: We selected a random sample of 748 students for ADHD screening from a population of around 43,000 primary school students. The Swanson, Nolan, and Pelham Rating Scale version IV was applied to both parents and teachers.

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Coronaviruses are large RNA viruses that can infect and spread among humans and animals. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), responsible for coronavirus disease 2019, has evolved since its first detection in December 2019. Deletions are a common occurrence in SARS-CoV-2 evolution, particularly in specific genomic sites, and may be associated with the emergence of highly competent lineages.

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Objective: To explore the ADHD diagnostic performance of a screening instrument, and which DSM-5 ADHD number of symptoms (criterion A) was best associated with impairment in a sample of students from 106 primary schools in Nampula, Mozambique.

Methods: A random sample of 748 students were assessed using SNAP-IV and 152 youths (76 positive and 76 negative screeners) were invited for psychiatric diagnostic confirmation.

Results: The performance of the screening instrument for predicting ADHD diagnosis was poor (all AUCs < 0.

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Tramadol, an analgesic classified as an "atypical opioid", exhibits both opioid and non-opioid mechanisms of action. This study aimed to explore these mechanisms, specifically the opioid-, cannabinoid-, nitric oxide-, and potassium channel-based mechanisms, which contribute to the peripheral antinociception effect of tramadol, in an experimental rat model. The nociceptive threshold was determined using paw pressure withdrawal.

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It has already been shown that serotonin can release endocannabinoids at the spinal cord level, culminating in inhibition of the dorsal horn. At the peripheral level, cannabinoid receptors modulate primary afferent neurons by inhibiting calcium conductance and increasing potassium conductance. Studies have shown that after the activation of opioid receptors and cannabinoids, there is also the activation of the NO/cGMP/K pathway, inducing cellular hyperpolarization.

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Cannabidiol (CBD) is the most abundant non-psychoactive component found in plants of the genus Cannabis. Its analgesic effect for the treatment of neuropathy has been widely studied. However, little is known about its effects in the acute treatment when Cannabidiol is administered peripherally.

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Background: Self-Organizing Maps (SOM) are an unsupervised learning clustering and dimensionality reduction algorithm capable of mapping an initial complex high-dimensional data set into a low-dimensional domain, such as a two-dimensional grid of neurons. In the reduced space, the original complex patterns and their interactions can be better visualized, interpreted and understood.

Methods: We use SOM to simultaneously couple the spatial and temporal domains of the COVID-19 evolution in the 278 municipalities of mainland Portugal during the first year of the pandemic.

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Article Synopsis
  • Surfactants from microbial sources, like lipopeptides produced by Bacillus species, are essential for industrial processes that need modified interface activity and stability in colloidal systems.* -
  • The study focused on the genome analysis of a new Bacillus vallismortis strain, TIM68, which produces surfactant lipopeptides and was evaluated for safety concerning virulence factors and antibiotic resistance.* -
  • Comparative genomics revealed three peptide synthetase operons in TIM68, including surfactin A and a novel lipopeptide called vallisin, with no identified pathogenic factors, suggesting its potential for biotechnological applications.*
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Article Synopsis
  • Ceará was the second most affected state in Brazil by COVID-19 in terms of cases and deaths, but its early pandemic dynamics were not well understood due to low genomic surveillance.
  • The study sequenced 34 genomes of SARS-CoV-2 and identified prevalent lineages, notably B.1.1.33 in 2020 and P.1 in 2021, along with other variants.
  • A total of 202 mutations were analyzed, revealing significant missense mutations that could help enhance the understanding of virus genetic diversity in Ceará despite limited data in 2020.
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Analyses of livestock genomes have been used to detect selection signatures, which are genomic regions associated with traits under selection leading to a change in allele frequency. The objective of the present study was to characterize selection signatures in Canchim composite beef cattle using cross-population analyses with the founder Nelore and Charolais breeds. High-density single nucleotide polymorphism genotypes were available on 395 Canchim representing the target population, along with genotypes from 809 Nelore and 897 Charolais animals representing the reference populations.

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Background: Bradykinin (BK) is an endogenous peptide involved in vascular permeability and inflammation. It has opposite effects (inducing hyperalgesia or antinociception) when administered directly in the central nervous system. The aim of this study was to evaluate whether BK may also present this dual effect when injected peripherally in a PGE-induced nociceptive pain model, as well as to investigate the possible mechanisms of action involved in this event in mice.

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Bckground: Aripiprazole is an antipsychotic drug used to treat schizophrenia and bipolar disorder. Recently, its peripheral analgesic component was evaluated, however, the mechanism involved in this effect is not fully established. Therefore, the aim of the study was to obtain pharmacological evidence for the involvement of the nitric oxide system in the peripheral antinociceptive effect induced by aripiprazole.

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Background: Curcumin is one of the compounds present in plants of the genus Curcuma sp., being very used not only as condiment but also with medicinal purposes. As an analgesic, papers highlight the efficacy of curcumin in the treatment of various types of pain.

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Our objectives were to estimate genetic parameters for male and female reproductive traits and their genetic correlations with body weight and carcass traits, evaluate the genetic trends over the years, and verify the effect of inbreeding on the phenotypes of Brahman cattle. The traits evaluated were body weights at 120, 210, 365, and 450 days of age (W120, W210, W365, and W450); scrotal circumference at 365 and 450 days of age (SC365 and SC450), age at first calving (AFC), gestation length (GL), stayability (STAY), ribeye area (REA), backfat thickness (BFT), and rump fat thickness (RFT). Direct heritability estimates ranged from 0.

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The participation of the peripheral opioid and cannabinoid endogenous systems in modulating muscle pain and inflammation has not been fully explored. Thus, the aim of this study was to investigate the involvement of these endogenous systems during muscular-tissue hyperalgesia induced by inflammation. Hyperalgesia was induced by carrageenan injection into the tibialis anterior muscles of male Wistar rats.

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Serotonin (5-HT) acts as a neurotransmitter in the central nervous system (CNS) and as a mediator released by enterochromaffin cells to regulate intestinal motility. However, this amine also plays an important role as an inflammatory mediator and induces phenotypic changes of nociceptors. Despite the wide knowledge of the role of 5-HT in nociception, most studies have focused on its role in the CNS, while a clear information about its role in peripheral tissues is still lacking.

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Animal venoms are an almost inexhaustible source for promising molecules with biological activity and the venom of spider is a good example of this. Among several other toxins obtained from this venom, PnTx4(6-1), also called δ-Ctenitoxin-Pn1a, was isolated and initially described as an insect toxin that binds to the site 3 of sodium channels in cockroach nerve cord synaptosomes () and slows down sodium current inactivation in isolated axons of this animal. This toxin did not cause any apparent toxicity to mice when intracerebroventricularly injected (30 μg).

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