Most current bioexposure assessments for UV filters focus on contaminants concentrations in fish from river and lake. To date there is not information available on the occurrence of UV filters in ...marine mammals. This is the first study to investigate the presence of sunscreen agents in tissue liver of Franciscana dolphin (Pontoporia blainvillei), a species under special measures for conservation. Fifty six liver tissue samples were taken from dead individuals accidentally caught or found stranded along the Brazilian coastal area (six states). The extensively used octocrylene (2-ethylhexyl-2-cyano-3,3-diphenyl-2-propenoate, OCT) was frequently found in the samples investigated (21 out of 56) at concentrations in the range 89–782 ng·g–1 lipid weight. São Paulo was found to be the most polluted area (70% frequency of detection). Nevertheless, the highest concentration was observed in the dolphins from Rio Grande do Sul (42% frequency of detection within that area). These findings constitute the first data reported on the occurrence of UV filters in marine mammals worldwide.
The COVID-19 pandemic has forced policy makers to decree urgent confinements to stop a rapid and massive contagion. However, after that stage, societies are being forced to find an equilibrium ...between the need to reduce contagion rates and the need to reopen their economies. The experience hitherto lived has provided data on the evolution of the pandemic, in particular the population dynamics as a result of the public health measures enacted. This allows the formulation of forecasting mathematical models to anticipate the consequences of political decisions. Here we propose a model to do so and apply it to the case of Portugal. With a mathematical deterministic model, described by a system of ordinary differential equations, we fit the real evolution of COVID-19 in this country. After identification of the population readiness to follow social restrictions, by analyzing the social media, we incorporate this effect in a version of the model that allow us to check different scenarios. This is realized by considering a Monte Carlo discrete version of the previous model coupled via a complex network. Then, we apply optimal control theory to maximize the number of people returning to "normal life" and minimizing the number of active infected individuals with minimal economical costs while warranting a low level of hospitalizations. This work allows testing various scenarios of pandemic management (closure of sectors of the economy, partial/total compliance with protection measures by citizens, number of beds in intensive care units, etc.), ensuring the responsiveness of the health system, thus being a public health decision support tool.
Pyrethroids (PYR) and UV filters (UVF) were investigated in tissues of paired mother-fetus dolphins from Brazilian coast in order to investigate the possibility of maternal transfer of these emerging ...contaminants. Comparison of PYR and UVF concentrations in maternal and fetal blubber revealed Franciscana transferred efficiently both contaminants to fetuses (F/M > 1) and Guiana dolphin transferred efficiently PYR to fetuses (F/M > 1) different than UVF (F/M < 1). PYR and UVF concentrations in fetuses were the highest-ever reported in biota (up to 6640 and 11,530 ng/g lw, respectively). Muscle was the organ with the highest PYR and UVF concentrations (p < 0.001), suggesting that these two classes of emerging contaminants may have more affinity for proteins than for lipids. The high PYR and UVF concentrations found in fetuses demonstrate these compounds are efficiently transferred through placenta. This study is the first to report maternal transfer of pyrethroids and UV filters in marine mammals.
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•First time maternal transfer of pyrethroids and UV filters in mammals was reported.•Pollutants in fetus tissues characterize their transplacental transfer.•Fetuses had pyrethroid and UV filter levels 10 times higher than their mothers.•Muscle was the organ presented with the highest concentrations of PYR and UVF.
Pyrethroids and UV filter concentrations in fetus and mother dolphin tissues demonstrated placenta and milk transfer in marine mammals.
Abstract Kynurenic acid (KYNA) is an endogenous metabolite of the kynurenine pathway for tryptophan degradation and an antagonist of both N-methyl- d -aspartate (NMDA) and alpha-7 nicotinic ...acetylcholine (α7nACh) receptors. KYNA has also been shown to scavenge hydroxyl radicals ( OH) under controlled conditions of free radical production. In this work we evaluated the ability of KYNA to scavenge superoxide anion (O2− ) and peroxynitrite (ONOO− ). The scavenging ability of KYNA (expressed as IC50 values) was as follows: OH = O2− > ONOO− . In parallel, the antiperoxidative and scavenging capacities of KYNA (0–150 μM) were tested in cerebellum and forebrain homogenates exposed to 5 μM FeSO4 and 2.5 mM 3-nitropropionic acid (3-NPA). Both FeSO4 and 3-NPA increased lipid peroxidation (LP) and ROS formation in a significant manner in these preparations, whereas KYNA significantly reduced these markers. Reactive oxygen species (ROS) formation were determined in the presence of FeSO4 and/or KYNA (0–100 μM), both at intra and extracellular levels. An increase in ROS formation was induced by FeSO4 in forebrain and cerebellum in a time-dependent manner, and KYNA reduced this effect in a concentration-dependent manner. To further know whether the effect of KYNA on oxidative stress is independent of NMDA and nicotinic receptors, we also tested KYNA (0–100 μM) in a biological preparation free of these receptors – defolliculated Xenopus laevis oocytes – incubated with FeSO4 for 1 h. A 3-fold increase in LP and a 2-fold increase in ROS formation were seen after exposure to FeSO4 , whereas KYNA attenuated these effects in a concentration-dependent manner. In addition, the in vivo formation of OH evoked by an acute infusion of FeSO4 (100 μM) in the rat striatum was estimated by microdialysis and challenged by a topic infusion of KYNA (1 μM). FeSO4 increased the striatal OH production, while KYNA mitigated this effect. Altogether, these data strongly suggest that KYNA, in addition to be a well-known antagonist acting on nicotinic and NMDA receptors, can be considered as a potential endogenous antioxidant.
Brain‐derived neurotrophic factor (BDNF) and neurotrophin‐4/5 (NT‐4/5) are trophic factors belonging to the neurotrophin family; in addition to their trophic role, both neurotrophins play an ...important role in modulating corticostriatal synaptic transmission. Failures in BDNF supply and mitochondrial dysfunction are among the factors involved in the striatal degeneration that occurs in Huntington's disease (HD). While the effects of BDNF have been widely studied in striatal degeneration, the role of NT‐4/5 has been less addressed. NT‐4/5 does not appear to exert effects similar to those of BDNF in HD. The physiological roles of these molecules in corticostriatal transmission have been evaluated separately, and we have demonstrated that sequential exposure to both neurotrophins results in different modulatory effects on corticostriatal transmission depending on the exposure order. In the present study, we evaluated the effects of BDNF followed by NT‐4/5 or NT‐4/5 followed by BDNF on corticostriatal synaptic transmission with field recordings in a male mouse model of HD produced by in vivo treatment with the mitochondrial toxin 3‐nitropropionic acid. Here, we show that these neurotrophins elicit an antagonistic or synergistic effect that depends on the activation of the truncated isoform or the stimulation of the full‐length isoform of the tropomyosin receptor kinase B.
NT‐4/5 antagonizes the effect of BDNF on corticostriatal transmission, while BDNF exhibits a synergic action on the NT‐4/5 amplitude increase of the synaptic spike in slices from a toxic model of HD in male mice. The antagonistic or synergistic effect depends on the activation of the TrkB‐T1 or TrkB‐FL respectively.
WO3 nanoparticles with hexagonal and monoclinic structures were synthesized via a microwave-assisted hydrothermal process without the use of any additives in which the microwave hydrothermal reaction ...time was 30 or 60min and was followed by different thermal treatments. The formation at different temperatures of hexagonal (h-WO3) and monoclinic (m-WO3) crystal structures of WO3 was confirmed by X-ray powder diffraction (XRD). The characterization of WO3 samples was complemented with scanning electron microscopy (SEM) images, which revealed a natural tendency of the oxides to form particles with ovoid shapes. The particle size of the prepared WO3 samples was between 20 and 100nm depending on the heat-treatment temperatures. The surface areas of the WO3 samples, as determined by the BET method, ranged from 2 to 113m2g−1 depending on their temperature of synthesis. The highest obtained specific surface area was nearly 37 times greater than that observed for commercial WO3. The photocatalytic activity of WO3 was evaluated with respect to the degradation reactions of rhodamine B (rhB), indigo carmine (IC) and tetracycline hydrochloride (TC) under UV–vis irradiation. The highest activity was observed in the sample obtained by thermal treatment at 700°C and with a microwave hydrothermal reaction time of 30min. The degree of mineralization of the organic dyes by WO3 was determined by the total organic carbon analysis (TOC) and was found to reach percentages of 95% for rhB, 65% for IC and 65% for TC after 96h of irradiation.
Tetranychus urticae
Koch (Acari: Tetranychidae), the two-spotted spider mite, is a pest that limits strawberry production in Mexico. Little is known about the interactions that occur between
T. ...urticae
and healthy strawberry plants or strawberry plants infested by conspecific spider mites. Therefore, in this study we evaluated the attraction of
T. urticae
to healthy strawberry plants mediated by volatile organic compounds (VOCs), and to plants damaged by conspecifics mediated by herbivore-induce plant volatiles (HIPVs). First, we conducted dual-choice tests using a Y-tube olfactometer with plants and extracts obtained through dynamic aeration. The volatile composition of the extracts was identified using gas chromatography-mass spectrometry (GC-MS). Once the compounds were identified, we also conducted dual-choice tests with selected synthetic compounds.
Tetranychus urticae
exhibited greater attraction to both healthy and damaged plants compared to the control (clean air). However, when healthy and damaged plants were offered simultaneously, there was no significant preference observed. Bioassays with extracts obtained by dynamic aeration yielded similar results. The identified compounds were terpenes and aromatic hydrocarbons. We found qualitative and quantitative changes between the VOCs emitted by the healthy plant and the HIPVs from mite-damaged plants. The individual compounds α-pinene (10 ng), pseudocumene (10 ng), and limonene (1 ng) and 10 ng of the blend made of α-pinene + pseudocumene + mesitylene + limonene (5:34:57:4) attracted more
T. urticae
than the control. However, the binary blend of pseudocumene + limonene (91:9) was more attractive than the other binary or three-compound blends evaluated. These results may contribute to developing strategies for the management of this pest.
This paper aims to describe the natural infection with
in
(white-nosed coati) from Yucatán, Mexico. Two carcasses of
were collected on a highway that crosses through a dense forest with patches used ...for agriculture and livestock activities. We performed necropsies, and two female adult nematode parasites from the heart of one specimen were collected and preserved for their molecular identification using a conventional PCR directed at a fragment of the small subunit (18S) ribosomal RNA (
rRNA) gene. Bioinformatic analysis showed a similarity of 99 % with three sequences from
(two from Japan). Additionally, we performed a phylogenetic tree with the recovered sequence. All these analyses showed that
is present in
from Mexico. The transmission of
toward populations of
sp. may be due to indirect and accidental contact with domestic dogs or wild canids that share the same environment.
Chemotherapy combined with radiation therapy is the most commonly used approach for treating locally advanced pancreatic cancer. The use of curative doses of radiation in this disease setting is ...constrained because of the close proximity of the head of the pancreas to the duodenum. The purpose of this study was to determine whether fasting protects the duodenum from high-dose radiation, thereby enabling dose escalation for efficient killing of pancreatic tumor cells.
C57BL/6J mice were either fed or fasted for 24 hours and then exposed to total abdominal radiation at 11.5 Gy. Food intake, body weight, overall health, and survival were monitored. Small intestines were harvested at various time points after radiation, and villi length, crypt depth, and number of crypts per millimeter of intestine were determined. Immunohistochemistry was performed to assess apoptosis and double-strand DNA breaks, and microcolony assays were performed to determine intestinal stem cell regeneration capacity. A syngeneic KPC model of pancreatic cancer was used to determine the effects of fasting on the radiation responses of both pancreatic cancer and host intestinal tissues.
We demonstrated that a 24-hour fast in mice improved intestinal stem cell regeneration, as revealed by microcolony assay, and improved host survival of lethal doses of total abdominal irradiation compared with fed controls. Fasting also improved survival of mice with orthotopic pancreatic tumors subjected to lethal abdominal radiation compared with controls with free access to food. Furthermore, fasting did not affect tumor cell killing by radiation therapy and enhanced γ-H2AX staining after radiation therapy, suggesting an additional mild radiosensitizing effect.
These results establish proof of concept for fasting as a dose-escalation strategy, enabling ablative radiation in the treatment of unresectable pancreatic cancer.
Demyelinating diseases alter myelin or the coating surrounding most nerve fibers in the central and peripheral nervous systems. The grouping of human central nervous system demyelinating disorders ...today includes multiple sclerosis (MS) and neuromyelitis optica spectrum disorders (NMOSD) as distinct disease categories. Each disease is caused by a complex combination of genetic and environmental variables, many involving an autoimmune response. Even though these conditions are fundamentally similar, research into genetic factors, their unique clinical manifestations, and lesion pathology has helped with differential diagnosis and disease pathogenesis knowledge. This review aims to synthesize the genetic approaches that explain the differential susceptibility between these diseases, explore the overlapping clinical features, and pathological findings, discuss existing and emerging hypotheses on the etiology of demyelination, and assess recent pathogenicity studies and their implications for human demyelination. This review presents critical information from previous studies on the disease, which asks several questions to understand the gaps in research in this field.
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