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Se evaluó el efecto del plaguicida organofosforado diazinón sobre el cultivo de linfocitos de sangre periférica humana. Este plaguicida se utiliza para el control de plagas de insectos y como acaricida. Las aplicaciones se hicieron con dos presentaciones distintas: una comercial de uso común, denominado Knox Out® y otra presentación de grado analítico de estándar. Para la obtención de células se empleó el método de sedimentación de eritrocitos. Los linfocitos aislados se incubaron en medio de cultivo por 24, 48 y 72 h, y fueron expuestos a diferentes concentraciones de diazinón (μM-mM). Los diferentes tratamientos se realizaron en ausencia o presencia del mitógeno fitohemaglutinina (PHA). Se realizó un primer set de barridos de diazinón sin PHA utilizando un amplio margen de concentraciones de 0.1 a 1 mM y un segundo set de experimentos con concentraciones de 5 μM hasta un máximo de 50 μM, en ausencia y presencia de PHA. Los resultados del primer set no mostraron efectos totalmente letales sobre los linfocitos visiblemente expuestos al microscopio. Las concentraciones del set de entre 5 y 50 μM fueron las que presentaron un mayor efecto sobre los linfocitos, disminuyendo el número de células viables o estimulando la proliferación sobre el control. Este resultado no se observó con diazinón comercial y PHA, donde sólo disminuyó el número de células viables. Se visualizaron, de forma ocasional, células con indicios de necrosis y apoptosis en los cultivos expuestos al diazinón. Abstract The effect of diazinon, an organophosphate pesticide used to control pests such as acarine and insects, was evaluated in cultured human peripheral blood lymphocyres. Two diazinon presentations were used: commercially available diazinon (Knox Out®, Mexico) and an analytical grade standard. The lymphocytes cellular pellet was obtained by the erythrocyte sedimentation method to obtain the mononuclear cells suspended in plasma. The lymphocytes were incubated in culture medium for 24, 48 and 72 h, in absence and presence of different diazinon concentrations (μM-mM). These treatments were in absence and presence of mitogen phytohemagglutinin (PHA). An initial study was carried out with a broad range of diazinon concentrations (0.1-1 mM) without PHA and since high concentration showed no effect, a second set of experiments was repeated using concentrations ranging from 5 until 50 μM of both pure and commercial diazinon, in the absence or presence of PHA. No significant effects were detected for the concentrations between 0.1 and 1 mM. Concentrations of 5 to 50 μM drastically caused reduction of cell viability or stimulated lymphocyte proliferation over control. Nevertheless, this effect was not observed in the presence of diazinon and PHA, only a decrease the quantity of viable cells was observed. Additionally, necrotic and apoptotic cells were visualized in cultures exposed to diazinon. Keywords: Organophosphate pesticide, lymphocyte, cell culture.

En este trabajo presentamos una revisión sobre hallazgos más relevantes de la neurofibromatosis tipo 2 (NF2), la cual se conoce por ser un desorden autosómico dominante caracterizado por la presencia de schwannomas vestibulares bilaterales, aunque pueden presentarse otros tumores como meningiomas y ependimomas. Esta enfermedad es causada por diversas mutaciones en el gen NF2, mismo que codifica una proteína conocida como merlina o schwannomina. Merlina está relacionada estructuralmente con la familia de proteínas ERM (Ezrina-Radixina- Moesina), encargadas de acoplar las señales provenientes de las glucoproteínas de la membrana plasmática con el citoesqueleto de actina. El gen NF2 es considerado como un supresor de tumores, y las evidencias indican que merlina funciona regulando la proliferación y el crecimiento celular. Sin embargo, los mecanismos específicos por medio de los cuales merlina cumple con su función siguen siendo un enigma. Se han identificado diversas moléculas que interactúan con merlina, lo que ha proporcionado indicios acerca de los diversos procesos celulares en los cuales esta molécula participa. Entre las proteínas que interactúan con merlina se incluyen proteínas de función estructural, receptores de membrana plasmática, proteínas citosólicas, GTPasas y adaptadores citoesqueléticos. Las mutaciones en el gen NF2 afectan la funcionalidad de merlina, lo que produce alteraciones en los mecanismos de acción de merlina dando como origen a la NF2. Son necesarios más estudios para determinar con certeza el papel de merlina en el control de la proliferación celular. Abstract In this work, we present a review over the most relevant information of the neurofibromatosis type 2 (NF2), which is known as an autosomal dominant disorder characterized by the presence of bilateral vestibular schwannomas. Other tumors such as meningiomas and ependymomas may be present. The disease is caused by mutations in the NF2 gene, which encodes a protein known as merlin or schwannomin. Merlin is structurally related to the ERM (Ezrina-Radixina-Moesina) family of proteins, a group of molecules responsible for linking the signals coming from the plasma membrane glycoproteins to the actin cytoskeleton. The NF2 gene is considered as a tumor suppressor gene, and the evidence indicates that merlin functions by regulating the cell growth and proliferation. However, the specific mechanisms through which merlin fulfill its functions as a tumor suppressor remains enigmatic. Several molecules that interact with merlin have been identified. This has provided clues to determine the cellular processes in which merlin participates. These molecules include structural proteins, plasma membrane receptors, cytosolic proteins, GTPases, and cytoskeletal adapters. Mutations in the NF2 gene affect the functionality of merlin, altering tha mecanisms of action of merlin, giving rise to NF2. Further studies are needed to determine the precise role of merlin on the control of cell proliferation. Keywords: neurofibromatosis type 2, merlin, cytoskeleton, plasma membrane.

Abstract The extensive use of pesticides can cause many human health problems. However, the effects of pesticides on a biochemical level are still poorly understood. In this study we analyzed the effect of different pesticides on the plasma membrane Ca2+-ATPase (PMCA) and on the sarco/ endoplasmic reticulum Ca2+-ATPase (SERCA) activities. Different amounts of pesticides were added to the Ca2+- dependent ATPase assays in order to determine if they were affecting the ATPase activity. The results showed that PMCA activity was partially inhibited by deltamethrin to 51.85% ± 3.7 when its concentration in the reaction medium was 0.5 mM, while cypermethrin and glyphosate stimulated the PMCA activity at the lowest concentrations tested. The maximum stimulatory effect of cypermethrin was of 155% ± 9.0 at a concentration of 0.2 mM. In addition, the herbicide glyphosate stimulated the activity 111% ± 2.0 at a concentration of 0.2 mM. In conclusion, our results showed that PMCA activity was partially inhibited by deltamethrin, but cypermethrin and glyphosate stimulated their activity. Our findings suggest that cypermethrin and deltamethrin have different structure- activity relationships. However, SERCA was not sensitive to deltamethrin or glyphosate. These differences may be reflected in disturbs over cellular calcium regulation. Resumen Se ha observado que la exposición de personas a plaguicidas puede causar problemas a la salud. Sin embargo, el estudio del efecto de plaguicidas a un nivel bioquímico ha sido pobremente estudiado. En este estudio, analizamos el efecto de cipermetrina, deltametrina y glifosato sobre la actividad enzimática de las Ca2+- ATPasa de membrana plasmática (PMCA) y de retículo sarcoplásmico (SERCA). Diferentes concentraciones de estos pesticidas fueron añadidas a los experimentos de actividad enzimática como estrategia para determinar si estos compuestos eran capaces de afectar la actividad enzimática de PMCA. Nuestros resultados demuestran que la actividad enzimática de PMCA fue parcialmente inhibida por deltametrina en un 51.85% ± 3.7 cuando su concentración fue de 0.5 mM, mientras que cipermetrina y glifosato estimularon la actividad enzimática de PMCA a menores concentraciones. El máximo efecto estimulatorio de cipermetrina fue de 155% ± 9.0 cuando el compuesto alcanzó una concentración de 0.2 mM. Además, el herbicida glifosato fue capaz de estimular la actividad enzimática de PMCA en un 111% ± 2.0 a concentraciones de 0.1-0.2 mM. En conclusión, nuestros resultados demostraron que la actividad enzimática de PMCA fue también parcialmente inhibida con deltametrina, pero al contrario de cipermetrina y glifosato la estimularon. Nuestros resultados sugieren que las diferencias en las estructuras químicas de cipermetrina y deltametrina se ven reflejadas en el efecto provocado sobre PMCA. Sin embargo, una enzima similar, SERCA, no fue afectada ni por deltametrina ni glifosato. Estas diferencias se pudieran ver reflejadas en disturbios sobre la regulación celular del calcio. Palabras clave: PMCA (ATPasa de Ca2+ de membrana plasmática), SERCA (ATPasa de Ca2+ de retículo endo/sarcoplásmico), actividad enzimática, cipermetrina, deltametrina, glifosato.

Este trabajo consiste en el desarrollo de un precursor de surfactante catiónico no convencional empleando el método estándar de síntesis de éteres de Williamsom. Tratamos de diseñar un nuevo tipo de surfactantes heterogéminis con un espaciador rígido y grupos de cabeza no idénticos en la estructura del surfactante. En la síntesis sugerida establecemos el paso preliminar para la obtención un surfactante con dos anillos aromáticos como espaciador rígido. El precursor sintetizado proporciona a la estructura del surfactante un espaciador rígido debido a la presencia del grupo bifenilo, esperando que el surfactante presente una reducción tanto de la curvatura de los agregados micelares, así como de la concentración micelar crítica (CMC), en comparación con reportes previos, donde emplean surfactantes convencionales. Para establecer los pasos de la síntesis se varía la temperatura en el tiempo de reacción, así como la velocidad de adición del compuesto que contiene el grupo de cabeza, deseado que se pretende añadir a la estructura del surfactante propuesto. Para la caracterización se emplearon las técnicas de espectroscopia de infrarrojo (FT-IR) y resonancia magnética nuclear (RMN). Abstract The present research is about the development of a precursor of unconventional cationic surfactant by using the standard procedures of the Williamson ether synthesis. It has been intended to design a new type of heterogemini surfactant with a rigid spacer and non identical head groups in the structure of the surfactant. In the synthesis suggested, the preliminary step to obtain a surfactant structure with two aromatic rings as rigid spacer has been established. This synthesized precursor provides with a rigid spacer to the structure of the surfactant due to the presence of a biphenyl group; it is expected that, with this surfactant, it further presents a reduction on both the curvature of micellar aggregates as well as the Critical Micelle Concentration (CMC) in respect of those previous reports where conventional surfactants are used. To establish the steps of the synthesis, the temperature during the time of reaction has been varied, as well as the velocity of addition of the compound containing the head group which is pretended to be added to the surfactant structure proposed. For the characterization, the infrared spectroscopy technique (FT-IR) and the Nuclear Magnetic Resonance (NMR) were used. Keywords: surfactants, synthesis, precursor, CMC.

Los plaguicidas son un amplio grupo de sustancias heterogéneas que producen un beneficio mediante la disminución de vectores que trasmiten enfermedades, y en el control de plagas que afectan la producción agrícola. En el presente trabajo estudiamos el efecto del glifosato (GF) sobre la actividad hidrolítica de la ATPasa dependiente de Ca2+ de membrana (PMCA) de eritrocito humano en su forma nativa (sin calmodulina [CaM]) o en el complejo activo CaM-PMCA. Nuestros resultados evidenciaron que el GF produjo un efecto dual, estimulatorio e inhibitorio, y el efecto fue dosis-dependiente: concentraciones bajas de GF (0.05-0.1 mM) estimularon la hidrólisis de ATP por PMCA en su conformación nativa en un 62.5%, y en el complejo activo por CaM el incremento fue de tan solo del 20% (basados en sus respectivos controles sin GF). Ambas formas conformaciones de PMCA fueron parcialmente inhibidas con GF 0.3-0.5 y 0.4-0.5 mM. El análisis sobre el efecto de GF en la afinidad de la enzima por el substrato (ATP), mostró que GF fue capaz de incrementar significativamente el consumo de ATP (Vmax), pero solo para la conformación nativa de PMCA. Sin embargo, la afinidad de la enzima por el sustrato (Km) no fue afectada en ninguna de las dos conformaciones de PMCA. En conclusión, GF afecta la velocidad del ciclo catalítico de PMCA sin afectar su afinidad por el sustrato, ello puede deberse a una interacción del plaguicida con el C-terminal de PMCA. Este efecto, pudiera ocasionar disturbios sobre la homeostasis celular del calcio desencadenando la activación de procesos celulares tales como la apoptosis. Abstract Pesticides are a broad group of heterogeneous substances with great benefit to the human population, as they are used for decreasing or killing a broad number of pests involved in transmission of diseases or involved in decreasing the levels of food production. In this work we studied the effect of glyphosate (GF) over the hydrolytic activity of plasma membrane Ca2+-ATPase (PMCA) from human erythrocytes, either in their native conformational state (without calmodulin [CaM]) or in the active complex CaM-PMCA. Our results showed that GF produced a dual effect, activation and inhibition, and the effect was a dose-response effect: at low-concentrations of GF (0.05-0.1 mM), ATP hydrolysis mediated by PMCA was stimulated up to 62.5%, however with CaM the increase was only 20% (with respect to the controls without GF). Both conformational forms of PMCA were partially inhibited with GF 0.3-0.5 and 0.4- 0.5 mM respectively. An analysis performed on PMCA affinity for the substrate (ATP) showed that GF was significantly increasing the ATP consumption (Vmax) and it was only significant for PMCA in their native conformation. However, for the two conformations studied, GF was unable to significantly affect the affinity of PMCA for the substrate ATP (Km). In conclusion, GF affects the velocity of the PMCA’s catalytic cycle without affecting its affinity for ATP, and this may be due to an interaction between GF and the C-terminus of PMCA. This effect may disturb calcium homeostasis in the cell, leading to the activation of several cellular processes such as apoptosis. Keywords: Ca2+-ATPase, plasma membrane, glyphosate, calmodulin, human erythrocyte.

A prematuridade se constitui num fator de risco para o desenvolvimento neurológico. Apesar desse fato, 80 a 90% das crianças prematuras desenvolvem-se normalmente, desde que não tenham ocorrido eventos que possam comprometer o cérebro no período pré, peri e pós-natal. O objetivo deste artigo é abordar a importância do tema, revisando definições, causas que determinam nascimentos prematuros, patologias peculiares e seus efeitos sobre o desenvolvimento neurológico. Procura-se reforçar a necessidade do seguimento desses recém-nascidos no sentido de, identificando precocemente alterações, interferir no desempenho final, a partir de atitudes adequadas a cada momento. Unitermos: Prematuridade; desenvolvimento neurológico; seguimento

We have studied the external surface (elytra) of the Sonoran Desert beetle (Eleodes eschscholtzii). Our aim was to assess whether this species has similar traits to some beetles from the Namibian Desert that are known to have hierarchical micropatterns that allow for water harvesting. We have conducted scanning electron microscopy (SEM) and apparent contact angle experiments on specimens collected at two sampling sites with different ambient humidity. The results show that the beetle’s external surface microstructure is composed of a compact array of polygons with randomly scattered protuberances. The density of the polygons in the microstructure is different for individuals collected in different sites: the polygon array is denser in the more humid site and less dense in the drier site. The measured contact angles also depend on the sampling site. For individuals collected in the drier site, the average apparent contact angle is 70°, whereas for the more humid site, the average apparent contact angle is 92°. FT-IR experiments are consistent with the presence of hydrophobic wax compounds in the studied surfaces. Our investigation opens new questions that are currently being addressed by experiments that are underway. For instance, it would be interesting to know whether the observed nanopatterns could be used in biomimetic devices for water harvesting purposes.

Since mid-2020 there have been complexities and difficulties in the standardisation and administration of nasopharyngeal swabs. Coupled with the variable and/or poor accuracy of lateral flow devices, this has led to increased societal ‘testing fatigue’ and reduced confidence in test results. Consequently, asymptomatic individuals have developed reluctance towards repeat testing, which remains the best way to monitor COVID-19 cases in the wider population. On the other hand, saliva-based PCR, a non-invasive, highly sensitive, and accurate test suitable for everyone, is gaining momentum as a straightforward and reliable means of detecting SARS-CoV-2 in symptomatic and asymptomatic individuals. Here, we provide an itemised list of the equipment and reagents involved in the process of sample submission, inactivation and analysis, as well as a detailed description of how each of these steps is performed.

Boerhaave syndrome (BS) is a spontaneous esophageal perforation which carries high mortality. Surgical treatment is well established, but the development of interventional endoscopy has proposed new therapies. We expose our experience in a Gastrointestinal and Endoscopy Unit. With a retrospective, observational, open-label, single center, consecutive case series. All patients diagnosed with BS who were managed in our center were included. Treated conservatively, endoscopically or surgically, according to their clinical condition and lesion presentation. Fourteen patients were included. Ten were treated with primary surgery. One conservatively. In total, 7/14 patients required an endoscopic treatment. All required metallic stents deployment, 3 cases over-the-scope-clips concomitantly and one case a novel technique an internal drain. 6/7 cases endoscopically treated achieved complete esophageal healing. In conclusion, endoscopy is an useful tool at all stages BS management: difficult diagnosis, primary treatment in selected patients and as salvage when surgery fails. With mortality rates and outcomes comparables to surgery.

A elaboração de silagem de pescado, além de ser alternativa para aproveitar resíduos do processamento do pescado, gera fonte de proteína animal de elevada qualidade para uso na alimentação de peixes. O objetivo deste estudo foi elaborar silagem ácida de pescado e aplicar em dietas para juvenis de carpa comum. A silagem foi produzida com exemplares de Serrassalmus macultus e vinagre comercial foi utilizado como agente ácido (75% do peso em volume). Após seca e moída, a silagem foi incorporada às rações nas proporções 0; 10; 20 ou 30% (tratamentos D0; D10; D20 ou D30, respectivamente). Foram distribuídos 20 juvenis de carpa comum (medidas iniciais 7,22 ± 0,22 g e 79,26 ± 0,94 mm) em cada uma das 12 unidades experimentais (tanques-rede de 0,175 m2). Os tanques-rede foram distribuídos em viveiro de 200 m2. Os peixes foram alimentados durante 46 dias, recebendo 4-5% da biomassa em ração, fracionado em duas alimentações diárias. No final do período experimental foram avaliados parâmetros de crescimento e composição corporal dos peixes. Maior peso final, comprimento total, ganhos em peso relativo e médio diário foram observados nos juvenis alimentados com D30 comparado à D0 e D10 sem diferir dos resultados apresentados pelos peixes alimentados com D20. Maior teor de matéria seca e cinzas foi observado para os peixes recebendo D0 e D10 e maior proteína bruta para os alimentados com D20. A incorporação de 20 ou 30% de silagem de pescado na ração é recomendada pois melhorou resultados zootécnicos para juvenis de carpa comum.

Abstract Numerous rodent studies have evaluated the effects of a maternal high-fat diet (HFD) on later in life susceptibility to Metabolic Syndrome (MetS) with varying results. Our aim was to quantitatively synthesize the available data on effects of maternal HFD around gestation on offspring’s body mass, body fat, plasma leptin, glucose, insulin, lipids and systolic blood pressure (SBP). Literature was screened and summary estimates of the effect of maternal HFD on outcomes were calculated by using fixed- or random-effects models. 362 effect sizes from 68 studies together with relevant moderators were collected. We found that maternal HFD is statistically associated with higher body fat, body weight, leptin, glucose, insulin and triglycerides levels, together with increased SBP in offspring later in life. Our analysis also revealed non-significant overall effect on offspring’s HDL-cholesterol. A main source of variation among studies emerged from rat strain and lard-based diet type. Strain and sex -specific effects on particular data subsets were detected. Recommendations are suggested for future research in the field of developmental programming of the MetS. Despite significant heterogeneity, our meta-analysis confirms that maternal HFD had long-term metabolic effects in offspring.

Abstract Background Globally, snake envenomation is a well-known cause of death and morbidity. In many cases of snakebite, myonecrosis, dermonecrosis, hemorrhage and neurotoxicity are present. Some of these symptoms may be provoked by the envenomation itself, but others are secondary effects of the produced oxidative stress that enhances the damage produced by the venom toxins. The only oxidative stress effect known in blood is the change in oxidation number of Fe (from ferrous to ferric) in hemoglobin, generating methemoglobin but not in other macromolecules. Currently, the effects of the overproduction of methemoglobin derived from snake venom are not extensively recorded. Therefore, the present study aims to describe the oxidative stress induced by Crotalus molossus nigrescens venom using erythrocytes. Methods Human erythrocytes were washed and incubated with different Crotalus molossus nigrescens venom concentrations (0–640 μg/mL). After 24 h, the hemolytic activity was measured followed by attenuated total reflectance-Fourier transform infrared spectroscopy, non-denaturing PAGE, conjugated diene and thiobarbituric acid reactive substances determination. Results Low concentrations of venom (40 μg/mL). This substance is not degraded by proteases present in the venom. By infrared spectroscopy, starting in 80 μg/mL, we observed changes in bands that are associated with protein damage (1660 and 1540 cm−1) and lipid peroxidation (2960, 2920 and 1740 cm−1). Lipid peroxidation was confirmed by conjugated diene and thiobarbituric acid reactive substance determination, in which differences were observed between the control and erythrocytes treated with venom. Conclusions Crotalus molossus nigrescens venom provokes hemolysis and oxidative stress, which induces methemoglobin formation, loss of protein structure and lipid peroxidation.

Relatamos o caso de um homem de 79 anos com história de lesões vesiculosas e bolhosas pruriginosas localizadas a nível palmar bilateral. Referia aparecimento há cerca de 2 anos, com resposta parcial a dermocorticóides de baixa-média potência e carácter recidivante. Ao exame objetivo apresentava múltiplas lesões vesiculobolhosas tensas com base eritematosa, a maioria em fase erosiva (Fig. 1). A nível plantar referia lesões no passado, que não apresentava no momento da consulta. Não apresentava outras alterações cutâneas ou mucosas. Foi enviada amostra para cultura de fungos que foi negativa. O estudo histopatológico de biópsia cutânea mostrou descolamento bolhoso subepidérmico com extensa reepitilização subjacente associado a infiltrado linfomononucleado perivascular rico em eosinófilos (Fig. 2). A imunofluorescência direta (IFD) de área perilesional mostrou depósitos lineares de C3 e IgG ao nível da junção dermo- epidérmica. Foram detectados anticorpos circulantes para BP180 (122 U/mL, normal >20 U/mL) por ELISA. Foi iniciado tratamento com prednisolona 30 mg/dia em desmame durante 2 semanas associado a dermocorticóide de alta potência com resolução das lesões e sem formação de novas bolhas em dois anos de follow-up.