A Dye Uptake Assay to Measure Large-Pore Channel Activity in Trypanosoma cruzi.

Large-pore channels allow the exchange of ions and molecules between the intra- and extracellular compartments. These channels are structures formed by several protein families with little or no evolutionary linkages that include connexins (Cxs), pannexins (Panxs), innexins (Inxs), CALHM1, and LRRC8 proteins. Recently, we have described the unnexins (Unxs) proteins expressed in Trypanosoma cruzi (T. cruzi) that also is like to form large-pore channels at the plasma membrane. In this chapter, we describe a dye uptake method for evaluating the unnexin-formed channel function in T. cruzi, as well as the methods for evaluating their participation in the transformation of trypomastigotes into amastigotes. These methods can facilitate understanding the role of large-pore channels in the parasite's biology.

Oral infectivity through carnivorism in murine model of Trypanosoma cruzi infection.

Introduction: Oral transmission of T. cruzi is probably the most frequent transmission mechanism in wild animals. This observation led to the hypothesis that consuming raw or undercooked meat from animals infected with T. cruzi may be responsible for transmitting the infection. Therefore, the general objective of this study was to investigate host-pathogen interactions between the parasite and gastric mucosa and the role of meat consumption from infected animals in the oral transmission of T. cruzi. Methods: Cell infectivity assays were performed on AGS cells in the presence or absence of mucin, and the roles of pepsin and acidic pH were determined. Moreover, groups of five female Balb/c mice were fed with muscle tissue obtained from mice in the acute phase of infection by the clone H510 C8C3hvir of T. cruzi, and the infection of the fed mice was monitored by a parasitemia curve. Similarly, we assessed the infective capacity of T. cruzi trypomastigotes and amastigotes by infecting groups of five mice Balb/c females, which were infected orally using a nasogastric probe, and the infection was monitored by a parasitemia curve. Finally, different trypomastigote and amastigote inoculums were used to determine their infective capacities. Adhesion assays of T. cruzi proteins to AGS stomach cells were performed, and the adhered proteins were detected by western blotting using monoclonal or polyclonal antibodies and by LC-MS/MS and bioinformatics analysis. Results: Trypomastigote migration in the presence of mucin was reduced by approximately 30%, whereas in the presence of mucin and pepsin at pH 3.5, only a small proportion of parasites were able to migrate (∼6%). Similarly, the ability of TCTs to infect AGS cells in the presence of mucin is reduced by approximately 20%. In all cases, 60-100% of the animals were fed meat from mice infected in the acute phase or infected with trypomastigotes or amastigotes developed high parasitemia, and 80% died around day 40 post-infection. The adhesion assay showed that cruzipain is a molecule of trypomastigotes and amastigotes that binds to AGS cells. LC-MS/MS and bioinformatics analysis, also confirmed that transialidase, cysteine proteinases, and gp63 may be involved in TCTs attachment or invasion of human stomach cells because they can potentially interact with different proteins in the human stomach mucosa. In addition, several human gastric mucins have cysteine protease cleavage sites. Discussion: Then, under our experimental conditions, consuming meat from infected animals in the acute phase allows the T. cruzi infection. Similarly, trypomastigotes and amastigotes could infect mice when administered orally, whereas cysteinyl proteinases and trans-sialidase appear to be relevant molecules in this infective process.

Exploring perceptions of extreme environments and extremophiles in Chilean schoolchildren: an ethnographic study.

Chile is unique because of its diverse extreme environment, ranging from arid climates in the north to polar climates in Patagonia. Microorganisms that live in these environments are called extremophiles, and these habitats experience intense ecosystem changes owing to climate warming. Most studies of extremophiles have focused on their biotechnological potential; however, no study has examined how students describe extremophiles. Therefore, we were interested in answering the following question: How do schoolchildren living in extreme environments describe their environments and extremophiles? We performed an ethnographic study and analyzed the results of 347 representative drawings of participants aged 12-16 years from three schools located in the extreme environments of Chile San Pedro de Atacama (hyper-arid, 2,400 m), Lonquimay (forest, 925 m), and Punta Arenas (sub-Antarctic, 34 m). The social representation approach was used to collect data, and systemic networks were used to organize and systematize the drawings. The study found that, despite differences between extreme environments, certain natural elements, such as trees and the sun, are consistently represented by schoolchildren. The analysis revealed that the urban and rural categories were the two main categories identified. The main systemic networks were rural-sun (21,1%) for hyper-arid areas, urban-tree (14,1%) for forest areas, and urban-furniture (23,4%) for sub-Antarctic areas. When the results were analyzed by sex, we found a statistically significant difference for the rural category in the 7th grade, where girls mentioned being more rural than boys. Students living in hyper-arid areas represented higher extremophile drawings, with 57 extremophiles versus 20 and 39 for students living in sub-Antarctic and forest areas, respectively. Bacteria were extremophiles that were more represented. The results provide evidence that natural variables and semantic features that allow an environment to be categorized as extreme are not represented by children when they are focused on and inspired by the environment in which they live, suggesting that school literacy processes impact representations of their environment because they replicate school textbooks and not necessarily their environment.

A Proposal to Study the Safety and Efficacy of Psilocybe cubensis in Preclinical and Clinical Studies as a Therapeutic Alternative for Major Depressive Disorder.

The pharmacological treatment of depression consists of taking antidepressant drugs for prolonged periods; its modest therapeutic effect can often be associated with significant adverse effects, while its discontinuation can lead to relapses. Psilocybin is today a novel and breakthrough therapy for major depression. It is a natural alkaloid in Psilocybe mushrooms, which are endemic to Mexico. Research on a larger scale is lacking in various populations, including the Mexican people. This proposal contemplates the experimental design of a preclinical (toxicity and pharmacological evaluation of an extract in mice) and clinical study by including the chemical analysis of a species of Psilocybe cubensis mushroom to characterize its main constituents. The clinical study will consider the safety evaluation by exploring tolerated doses of Psilocybe cubensis by measuring pharmacokinetic parameters after oral administration in healthy adults and an open trial on a sample of patients with major depressive disorder to assess the safety and efficacy of fully characterized Psilocybe cubensis in a two-single doses treatment, (with assisted psychotherapy), compared with the traditional care model at the Instituto Nacional de Psiquiatría Ramón de la Fuente Muñiz in Mexico City. This report presents the design of a research project with preclinical and clinical experimental components.

Trypanosoma cruzi pathogenicity involves virulence factor expression and upregulation of bioenergetic and biosynthetic pathways.

The molecular repertoire of Trypanosoma cruzi effects its virulence and impacts the clinical course of the resulting Chagas disease. This study aimed to determine the mechanism underlying the pathogenicity of T. cruzi. Two T. cruzi cell lines (C8C3hvir and C8C3lvir), obtained from the clone H510 C8C3 and exhibiting different virulence phenotypes, were used to evaluate the parasite's infectivity in mice. The organ parasite load was analysed by qPCR. The proteomes of both T. cruzi cell lines were compared using nLC-MS/MS. Cruzipain (Czp), complement regulatory protein (CRP), trans-sialidase (TS), Tc-85, and sialylated epitope expression levels were evaluated by immunoblotting. High-virulence C8C3hvir was highly infectious in mice and demonstrated three to five times higher infectivity in mouse myocardial cells than low-virulence C8C3lvir. qPCR revealed higher parasite loads in organs of acute as well as chronically C8C3hvir-infected mice than in those of C8C3lvir-infected mice. Comparative quantitative proteomics revealed that 390 of 1547 identified proteins were differentially regulated in C8C3hvir with respect to C8C3lvir. Amongst these, 174 proteins were upregulated in C8C3hvir and 216 were downregulated in C8C3lvir. The upregulated proteins in C8C3hvir were associated with the tricarboxylic acid cycle, ribosomal proteins, and redoxins. Higher levels of Czp, CRP, TS, Tc-85, and sialylated epitopes were expressed in C8C3hvir than in C8C3lvir. Thus, T. cruzi virulence may be related to virulence factor expression as well as upregulation of bioenergetic and biosynthetic pathways proteins.

Immobilization Systems of Antimicrobial Peptide Ib-M1 in Polymeric Nanoparticles Based on Alginate and Chitosan.

The development of new strategies to reduce the use of traditional antibiotics has been a topic of global interest due to the resistance generated by multiresistant microorganisms, including Escherichia coli, as etiological agents of various diseases. Antimicrobial peptides are presented as an alternative for the treatment of infectious diseases caused by this type of microorganism. The Ib-M1 peptide meets the requirements to be used as an antimicrobial compound. However, it is necessary to use strategies that generate protection and resist the conditions encountered in a biological system. Therefore, in this study, we synthesized alginate and chitosan nanoparticles (Alg-Chi NPs) using the ionic gelation technique, which allows for the crosslinking of polymeric chains arranged in nanostructures by intermolecular interactions that can be either covalent or non-covalent. Such interactions can be achieved through the use of crosslinking agents that facilitate this binding. This technique allows for immobilization of the Ib-M1 peptide to form an Ib-M1/Alg-Chi bioconjugate. SEM, DLS, and FT-IR were used to determine the structural features of the nanoparticles. We evaluated the biological activity against E. coli ATCC 25922 and Vero mammalian cells, as well as the stability at various temperatures, pH, and proteases, of Ib-M1 and Ib-M1/Alg-Chi. The results showed agglomerates of nanoparticles with average sizes of 150 nm; an MIC of 12.5 µM, which was maintained in the bioconjugate; and cytotoxicity values close to 40%. Stability was maintained against pH and temperature; in proteases, it was only evidenced against pepsin in Ib-M1/Alg-Chi. The results are promising with respect to the use of Ib-M1 and Ib-M1/Alg-Chi as possible antimicrobial agents.

New PEPTIR-2.0 Peptide Designed for Use as Recognition Element in Electrochemical Biosensors with Improved Specificity towards E. coli O157:H7.

The detection of pathogens through alternative methodologies based on electrochemical biosensors is being studied. These devices exhibit remarkable properties, such as simplicity, specificity, and high sensitivity in monitoring pathogens. However, it is necessary to continue conducting studies that adequately improve these characteristics, especially the recognition molecule. This work aims to design and evaluate a new peptide, named PEPTIR-2.0, as a recognition molecule in electrochemical biosensors to detect E. coli O157:H7 in water. PEPTIR-2.0 was obtained from modifications of the PEPTIR-1.0 peptide sequence, which was previously reported and exhibited excellent properties for detecting and quantifying this pathogenic microorganism. PEPTIR-1.0 is a peptide analogous to the TIR (Translocated Intimin Receptor) protein capable of interacting with the Intimin outer membrane. The basis of this study was to obtain, by using bioinformatics tools, a molecule analogous to PEPTIR-1.0 that maintains its three-dimensional structure but increases the hydrophobic interactions between it and Intimin, since these intermolecular forces are the predominant ones. The designed PEPTIR-2.0 peptide was immobilized on screen-printed electrodes modified with gold nanoparticles. The detection capacity of E. coli O157:H7 in water was evaluated using electrochemical impedance spectroscopy in the presence of other microorganisms, such as P. aeruginosa, S. aureus, and non-pathogenic E. coli. The results showed that PEPTIR-2.0 confers remarkable specificity to the biosensor towards detecting E. coli, even higher than PEPTIR-1.0.

A Bioinspired Peptide in TIR Protein as Recognition Molecule on Electrochemical Biosensors for the Detection of E. coli O157:H7 in an Aqueous Matrix.

Currently, the detection of pathogens such as Escherichia coli through instrumental alternatives with fast response and excellent sensitivity and selectivity are being studied. Biosensors are systems consisting of nanomaterials and biomolecules that exhibit remarkable properties such as simplicity, portable, affordable, user­friendly, and deliverable to end­users. For this, in this work we report for the first time, to our knowledge, the bioinformatic design of a new peptide based on TIR protein, a receptor of Intimin membrane protein which is characteristic of E. coli. This peptide (named PEPTIR­1.0) was used as recognition element in a biosensor based on AuNPs­modified screen­printed electrodes for the detection of E. coli. The morphological and electrochemical characteristics of the biosensor obtained were studied. Results show that the biosensor can detect the bacteria with limits of detection and quantification of 2 and 6 CFU/mL, respectively. Moreover, the selectivity of the system is statistically significant towards the detection of the pathogen in the presence of other microorganisms such as P. aeruginosa and S. aureus. This makes this new PEPTIR­1.0 based biosensor can be used in the rapid, sensitive, and selective detection of E. coli in aqueous matrices.

Cambios en el perfil protéico de E. coli O157:H7 frente al tratamiento con Ib-M1 e IONP@Ib-M1 / Changes in the protein profile of E. coli O157: H7 against treatment with Ib-M1 and IONP@Ib-M1 / Identificação de alterações no perfil protetor de E. coli O157: H7 contra o tratamento com Ib-M1 e IONP@Ib-M1

Resumen Escherichia coli 0157:H7 es una bacteria patógena reconocida por su capacidad de resistencia a diversos antibióticos; razón por la cual, se generan complicaciones en el tratamiento de infecciones producidas por esta bacteria. El péptido Ib-M1 y el bioconjugado I0NP@Ib-M1 han surgido como una nueva alternativa antimicrobiana contra E. coli 0157:H7. El mecanismo de acción de Ib-Mi e I0NP@Ib-M1 contra esta bacteria aún es desconocido; por lo tanto, el objetivo de esta investigación fue identificar el cambio en el perfil de proteínas de E. coli 0157:H7 luego del tratamiento con Ib-M1 e I0NP@ Ib-M1 como primer paso para determinar su mecanismo de acción. Para esto, se llevó a cabo la obtención de proteínas, posteriormente se realizó una electroforesis bidimensional para finalmente realizar la determinación de la variabilidad de los perfiles proteicos. Una vez obtenidos estos perfiles, se llevó a cabo un análisis de varianza (AN0VA). Se identificaron 72 proteínas expresadas diferencialmente, las cuales pueden relacionarse con el efecto sobre el crecimiento de la bacteria en presencia de Ib-M1 e I0NP@Ib-M. Estas proteínas se encuentran involucradas en procesos de transferencia de grupos acilo (proteína Yhbs), translocación de lipoproteínas (proteína LolA) y transporte de aminoácidos (proteína GpmA), entre otros.

Abstract Escherichia coli 0157: H7 is a pathogenic bacterium which is recognized for the ability to resist multiple antibiotics; accordingly, complications occur in the treatment of infections caused by this bacterium. The Ib-M1 peptide and the I0NP @ Ib-M1 bioconjugate have emerged as a new antimicrobial alternatives against E. coli 0157: H7. The mechanism of action of Ib-M1 and I0NP @ Ib-M1 against this bacterium is still unknown; therefore, the goal of this research was to identify the change in the proteins profile of E. coli 0157: H7 after treatment with Ib-M1 and I0NP @ Ib-M1 as a first step to determine its mechanism of action. For this, the proteins were obtained first, and then a two-dimensional electrophoresis was performed to finally determine the variability of the protein profiles. 0nce the protein profiles were obtained, an analysis of variance (AN0VA) was carried out. 72 differentially expressed proteins were identified, which can be connected to the effect on the bacterium's growth in the presence of Ib-M1 and I0NP @ Ib-M. These proteins are involved in acyl groups transfer processes (Yhbs protein), lipoprotein translocation (LolA protein) and amino acid transport (GpmA protein), among others.

Resumo Escherichia coli O157: H7 é uma bactéria patogênica reconhecida por sua capacidade de resistir a vários antibióticos; razão pela qual, complicações são geradas no tratamento de infecções produzidas por essa bactéria. O peptídeo Ib-M1 livre e imobilizado em nanopartículas magnéticas de óxido de ferro (IONP @ Ib-M1) surgiu como uma nova alternativa antimicrobiana contra E. coli O157: H7 e isolados clínicos desta bactéria. O mecanismo de ação de Ib-M1 e IONP @ Ib-M1 contra E. coli O157: H7 ainda é desconhecido; Portanto, o objetivo desta pesquisa foi identificar a alteração no perfil proteico de E. coli O157: H7 após o tratamento com Ib-M1 e IONP @ Ib-M1 como um primeiro passo para determinar seu mecanismo de ação. Para isso, foi realizada a obtenção das proteínas, posteriormente foi realizada uma eletroforese bidimensional para finalmente determinar a variabilidade dos perfis protéicos. Uma vez obtidos os perfis de proteínas, foi realizada uma análise de variância (ANOVA). Os resultados mostram a identificação de proteínas expressas diferencialmente e que estão envolvidas em processos de transferência de grupos acila (proteína Yhbs), translocação de lipoproteínas (proteína LolA) e transporte de aminoácidos (proteína GpmA), entre outros.

Ascorbate Attenuates Oxidative Stress and Increased Blood Pressure Induced by 2-(4-Hydroxyphenyl) Amino-1,4-naphthoquinone in Rats.

Quinone derivatives like 2-(4-hydroxyphenyl) amino-1,4-naphthoquinone (Q7) are used as antitumor agents usually associated with adverse effects on the cardiovascular system. The objective of this study was to evaluate the cardioprotective effect of ascorbate on Q7-induced cardiovascular response in Wistar rats. In this study, blood pressure, vascular reactivity, and intracellular calcium fluxes were evaluated in cardiomyocytes and the rat aorta. We also measured oxidative stress through lipid peroxidation (TBARS), superoxide dismutase- (SOD-) like activity, and H2O2 generation. Oral treatment of rats with ascorbate (500 mg/kg) for 20 days significantly (p < 0.05) reduced the Q7-induced increase (10 mg/kg) in blood pressure and heart rate. The preincubation with ascorbate (2 mM) significantly (p < 0.05) attenuated the irregular beating of the atrium induced by Q7 (10-5 M). In addition, ascorbate induced endothelial vasodilation in the presence of Q7 in the intact aortic rings of a rat and reduced the cytosolic calcium levels in vascular smooth muscle cells. Ascorbate also reduced the Q7-induced oxidative stress in vivo. Ascorbate also attenuated Q7-induced SOD-like activity and increased TBARS levels. These results suggest a cardioprotective effect in vivo of ascorbate in animals treated orally with a naphthoquinone derivative by a mechanism involving oxidative stress.

Decreased cruzipain and gp85/trans-sialidase family protein expression contributes to loss of Trypanosoma cruzi trypomastigote virulence.

Two cell lines derived from a single Trypanosoma cruzi clone by long-term passaging generated a highly virulent (C8C3hvir) and a low virulent (C8C3lvir) cell line. The C8C3hvir cell line was highly infective and lethal to Balb/c mice, and the C8C3lvir cell line was three- to five-fold less infective to mouse cardiomyocytes than C8C3hvir. The highly virulent T. cruzi cell line abundantly expressed the major cysteine proteinase cruzipain (Czp), complement regulatory protein (CRP) and trans-sialidase (TS), all of which are known to act as virulence factors in this parasite. The in vitro invasion capacity and in vivo Balb/c mouse infectiveness of the highly virulent strain was strongly reduced by pre-treatment with antisense oligonucleotides targeting TS or CRP or with E64d. Based on these results, we conclude that decreased levels of TS, CRP and Czp expression could contribute to loss of T. cruzi trypomastigote virulence.

Caracterización de los genotipos de rotavirus encontrados en muestras de heces diarreicas en niños menores de 5 años captados por los establecimientos centinela de la Secretaria de Salud de Honduras durante 2014

Objetivo: Caracterizar los genotipos de Rotavirus, encontrados en muestras de hecesdiarreicas en niños menores de 5 años captados por los establecimientos centinela de laSecretaria de Salud en Honduras durante 2014.Metodología: Es un estudio Descriptivo de corte transversal, la muestra estuvoconformada por un total de 68 casos procedentes de los hospitales de la VigilanciaCentinela de Rotavirus, se revisó la base de datos y libro de registro de resultados de lavigilancia Centinela de Rotavirus, para el procesamiento de datos se utilizó el programaEpi Info 7 y Hoja de Cálculo Excel para realizar tablas, gráficos con porcentaje yfrecuencias.Resultados: El 45,6 % está en el rango de edad de 09-17 meses, el género másfrecuente, fue el hombre con 47%, se identificó la circulación de 6 genotipos de Rotavirusen 11 departamentos de Honduras donde el 35,1% proceden de Francisco Morazán, el44,1% de los casos no posee el dato del estado vacunal, el 51,5% de los menores de 5años inicio síntomas en el tercer trimestre (comprendidos entre los meses deJulio-Septiembre).Se identificó al genotipo G12P[8] en el 89,6% de los casos encontrándose en losdepartamentos de Atlántida, Choluteca, Comayagua, Copan, Cortes, Francisco Morazán,Intibucá, Ocotepeque, El Paraíso, Santa Bárbara y Yoro. En el 54,1% de los casos seidentificó el genotipo G12P[8] se detectó durante el tercer trimestre.Conclusiones: Se determinó que el genotipo del virus de Rotavirus que predominodurante el 2014 fue el genotipo G12P[8] el cual circulo durante todo el año, pero seobservó su alza a partir del segundo trimestre donde se presentó un incremento decasos coincidiendo con el de inicio de invierno.

[Skin cancer incidence in Zacatecas]. / Incidencia de cáncer de piel en Zacatecas.

BACKGROUND: Skin cancer is the most frequent cancer related to ultraviolet radiation. The aim was to estimate the incidence of skin cancer type, melanoma and non-melanoma in Zacatecas, Mexico. METHODS: An epidemiological study was carried out during the period from 2008 to 2012. The data were obtained from the Instituto Mexicano del Seguro Social (IMSS), Instituto de Seguridad y Servicios Sociales de los Trabajadores del Estado (ISSSTE), Secretaría de Salud de Zacatecas (SSZ) and a private source, the Centro Médico Alameda. The incidence and the global prevalence were estimated. RESULTS: We studied 958 skin cancer cases, histopathologically confirmed. The cases were distributed as: 63.6 % basal cell carcinomas, 25.8 % squamous cell carcinomas, and 10.6 % melanoma. Significantly higher proportions were observed in women in the basal cell carcinomas (60.4 %) and squamous cell carcinomas (53.4 %). However, in the case of melanoma, the major proportion was observed in men (55.9 %). The more frequent skin cancer location was the face and for basal cell carcinoma was the nose (53 %); for squamous cell carcinomas were the lips (36 %), and for melanoma it was also the nose (40 %). The skin cancer incidence was estimated in 20 cases for each 100 000 inhabitants. Linear regression analysis showed that the skin cancer is increasing at an annual rate of 10.5 %. CONCLUSIONS: The anatomical location indicates that solar UV radiation is a risk factor, since the face is the zone with major exposure to solar radiation.

INTRODUCCIÓN: el cáncer de piel es una neoplasia relacionada con la radiación ultravioleta solar. El objetivo fue estimar la incidencia del cáncer de piel de tipo melanoma y no-melanoma. MÉTODOS: se llevó a cabo un estudio epidemiológico entre 2008 y 2012 en Zacatecas, México. La información se obtuvo de los registros confirmados de cáncer de piel en el Instituto Mexicano del Seguro Social, el Instituto de Seguridad y Servicios Sociales de los Trabajadores del Estado, la Secretaría de Salud de Zacatecas y el laboratorio privado del Centro Médico Alameda. Se calculó la incidencia y la prevalencia global. RESULTADOS: se estudiaron 958 casos de cáncer de piel: 63.6 % de carcinoma basocelular, 25.8 % de espinocelular y 10.6 % de melanoma. Se observó una mayor prevalencia de mujeres: 60.4 % en carcinoma basocelular y 53.4 % en carcinoma espinocelular. En el melanoma prevalecieron los hombres (55.9 %). La región anatómica donde predominó el cáncer de piel fue la cara: la nariz (53 %) en carcinoma basocelular, los labios (36 %) en carcinoma espinocelular y la nariz (40 %) en melanoma. La incidencia estimada fue 20 casos por cada 100 000 habitantes. El análisis de regresión lineal mostró que el cáncer de piel se incrementa 10.5 % anualmente. Conclusiones: la ubicación de las lesiones sugiere que un factor de riesgo es la exposición a los rayos solares UV.

Role of gap junctions and hemichannels in parasitic infections.

In vertebrates, connexins (Cxs) and pannexins (Panxs) are proteins that form gap junction channels and/or hemichannels located at cell-cell interfaces and cell surface, respectively. Similar channel types are formed by innexins in invertebrate cells. These channels serve as pathways for cellular communication that coordinate diverse physiologic processes. However, it is known that many acquired and inherited diseases deregulate Cx and/or Panx channels, condition that frequently worsens the pathological state of vertebrates. Recent evidences suggest that Cx and/or Panx hemichannels play a relevant role in bacterial and viral infections. Nonetheless, little is known about the role of Cx- and Panx-based channels in parasitic infections of vertebrates. In this review, available data on changes in Cx and gap junction channel changes induced by parasitic infections are summarized. Additionally, we describe recent findings that suggest possible roles of hemichannels in parasitic infections. Finally, the possibility of new therapeutic designs based on hemichannel blokers is presented.

Effect of phenylephrine and endothelium on vasomotion in rat aorta involves potassium uptake.

Vasomotion is defined as the rhythmic contractions in blood vessels, consisting of two components: vasoconstriction and oscillations of the plasma membrane potential. To determine whether vasomotion is associated with changes in K(+) uptake, we measured the effect of phenylephrine (PE) and acetylcholine (ACh) on the K(+) uptake and vascular reactivity in rat aortic rings. We found that the incubation of aortic rings with 10(-7) M PE (210 ± 28 mg maximum amplitude), and 10(-6) M ACh (177 ± 6 mg maximum amplitude) produced the highest rhythmic contractions. Both 10(-7) M PE and 10(-6) M ACh significantly increased K(+) uptake in endothelium-intact aorta versus control (121 % PE, 117 % ACh). Removal of the endothelium blunted rhythmic contractions and decreased K(+) uptake in presence of vasoactive substances (88 % PE, 81 % ACh). The inhibition of nitric oxide synthase with 10(-4) M L-NNA significantly reduced the rhythmic contractions, and it was reversed in the presence of 10(-8) M sodium nitroprusside (SNP; a nitric oxide donor). Also, we found that 10(-4) M L-NNA significantly decreased the effect of 10(-7) M PE on K(+) uptake in aortic rings (104 % PE + L-NNA vs. control). The incubation of endothelium-denuded rings with 10(-8) M SNP significantly increased the K(+) uptake (116 % SNP vs. control), similar to those observed in the presence of 10(-6) M ACh. The inhibition of protein kinase G with KT-5823 blocked SNP-mediated increase in K(+) uptake. In conclusion, these data suggest that a certain range of K(+) uptake is necessary to induce the rhythmic contractions in response to vasoactive substances.

Modulation of gap junction channels and hemichannels by growth factors.

Gap junction hemichannels and cell-cell channels have roles in coordinating numerous cellular processes, due to their permeability to extra and intracellular signaling molecules. Another mechanism of cellular coordination is provided by a vast array of growth factors that interact with relatively selective cell membrane receptors. These receptors can affect cellular transduction pathways, including alteration of intracellular concentration of free Ca(2+) and free radicals and activation of protein kinases or phosphatases. Connexin and pannexin based channels constitute recently described targets of growth factor signal transduction pathways, but little is known regarding the effects of growth factor signaling on pannexin based channels. The effects of growth factors on these two channel types seem to depend on the cell type, cell stage and connexin and pannexin isoform expressed. The functional state of hemichannels and gap junction channels are affected in opposite directions by FGF-1 via protein kinase-dependent mechanisms. These changes are largely explained by channels insertion in or withdrawal from the cell membrane, but changes in open probability might also occur due to changes in phosphorylation and redox state of channel subunits. The functional consequence of variation in cell-cell communication via these membrane channels is implicated in disease as well as normal cellular responses.

Efecto del butirato de sodio sobre algunos parámetros productivos de gallinas de postura en semilibertad / Effect of sodium butyrate on productive performance of laying hens in a semi-free range system

An experiment was conducted with 32 week-old 470 ISA-Babcock B380 laying hens, housed in floor pens with wheat-straw litter, to study the replacement of the antibiotic growth promoter (bacitracin zinc 30 ppm) with sodium butyrate (300 g/ton) in the diet. Results in 24 weeks of experimentation were similar between treatments (P > 0.05), in: egg production (92.6 and 91.9%), egg weight (63.0 and 62.9 g), egg mass / bird / day (58.4 and 57.7 g), feed consumption / bird / day (123.6 and 124.3 g), feed conversion (2.11 and 2.15), egg albumen quality (Haugh Units 82.9 and 83), yolk color DSM fan (10.3 and 9.9), shell thickness (0.392 and 0.394 mm) and weight of the shell (6.26 and 8.03 g). According to information obtained in 24 weeks with 32 week old hens, the addition of sodium butyrate to feed as a substitute for the growth promoter (bacitracin zinc), was similar in the productive performance and egg quality.

Se realizó un experimento con 470 gallinas de la estirpe ISA-Babcock B380 de 32 semanas de edad, alojadas en pisos con cama de paja de trigo, para estudiar la sustitución del antibiótico promotor de crecimiento (bacitracina cinc 30 ppm) por butirato de sodio (300 g/ton) en la dieta. Los resultados obtenidos en 24 semanas de experimentación fueron similares (P > 0.05) entre tratamientos, en: porcentaje de postura (92.6 y 91.9%), peso del huevo (63.0 y 62.9 g), masa del huevo/ ave/día (58.4 y 57.7 g), consumo/ave/día (123.6 y 124.3 g), conversión alimenticia (2.11 y 2.15), calidad de la albúmina del huevo (82.9 y 83 Unidades Haugh), color de la yema con el abanico DSM (10.3 y 9.9), grosor de cascarón (0.392 y 0.394 mm) y peso del cascarón (6.26 y 8.03 g). De acuerdo con la información obtenida en 24 semanas de experimentación, con gallinas de 32 semanas de edad, la adición de butirato de sodio en el alimento, como sustituto del promotor de crecimiento (bacitracina cinc), fue similar en el comportamiento productivo y la calidad del huevo.

Efecto del butirato de sodio en dietas para gallinas sobre el comportamiento productivo, calidad del huevo y vellosidades intestinales / Effect of sodium butyrate on diets for laying hens on the productive performance, egg quality and intestinal villi

In this study, productive performance, quality of eggs and histological analysis of intestinal villi of the duodenum (length and width) was evaluated in Bovans laying hens of 63 weeks of age, with the addition of butyrate in the diet ( 0, 300, 500 ppm). The results obtained in ten weeks of experimentation showed a response (P < 0.05) on egg production percentaje (86.4, 92.2 and 89.6), egg weight (63.4, 63.4 and 64.1 g), feed consumption/bird/day (111.4, 111.9 and 113.4 g), feed conversion (2.09, 1.95 and 2.03), micro-fractures percentaje (20.8, 14.9 and 12.9), broken eggs percentaje (2.6, 2.1 and 0.6), length of villi (1.15, 1.22 and 1.32 mm) and villi width (0.467, 0.500 and 0.532 mm) to the addition of butyrate. These results indicate the beneficial effect of butyrate in laying hens in the last third of its first production cycle. From information obtained in this study, it is concluded that sodium butyrate on diets at 500 ppm for Bovans laying hens of 63 weeks of age, improves the productive performance, shell quality and intestinal villi integrity.

En el presente estudio se evaluó el comportamiento productivo, calidad del huevo y análisis histológico de vellosidades intestinales de duodeno (largo y ancho) en gallinas de la estirpe Bovans, de 63 semanas de edad, con adición de butirato en la dieta (0, 300, 500 ppm). Los resultados obtenidos en diez semanas de experimentación mostraron respuesta (P < 0.05) en porcentaje de postura (86.4, 92.2 y 89.6), peso del huevo (63.4, 63.4 y 64.1 g) consumo/ave/día (111.4, 111.9 y 113.4 g), conversión alimentaria (2.09, 1.95 y 2.03), de microfracturas (20.8, 14.9 y 12.9), de huevos rotos (2.6, 2.1 y 0.6), longitud de vellosidades (1.15, 1.22 y 1.32 mm) y ancho de vellosidades (0.467, 0.500 y 0.532 mm) a la adición de butirato. Los resultados indican el efecto benéfico del butirato en gallinas ponedoras en el último tercio de su primer ciclo de producción. De la información obtenida en el presente estudio se concluye que el butirato de sodio en dietas a 500 ppm para gallinas Bovans, de 63 semanas de edad, mejora el comportamiento productivo, la calidad del cascarón y la integridad de las vellosidades intestinales.

Equilibrative nucleoside transporters in fetal endothelial dysfunction in diabetes mellitus and hyperglycaemia.

Diabetes mellitus types 1 and 2, and gestational diabetes are characterized by abnormal D-glucose metabolism and hyperglycaemia, and induce foetal endothelial dysfunction with implications in adult life increasing the risk of vascular diseases. Synthesis of nitric oxide (NO) and uptake of L-arginine (i.e. the L-arginine/NO signalling pathway) and adenosine (a vasoactive endogenous nucleoside) by the umbilical vein endothelium is altered in pathological pregnancies, including pregnancies with pre-established diabetes mellitus or in gestational diabetes. The mechanisms underlying these alterations include differential expression of equilibrative nucleoside transporters (ENTs), amino acid transporters and NO synthases (NOS). Modulation of ENTs and NOS expression and activity in endothelium involves several signalling molecules, including protein kinase C, mitogen-activated protein kinases p42 and p44, calcium and phosphatidyl inositol 3 kinase. Elevated extracellular D-glucose and diabetes alters human endothelial function. However, information regarding modulation the transport capacity as well as expression of ENTs is limited. This review focuses on the effect of diabetes mellitus and gestational diabetes, and hyperglycaemia on the reported mechanisms described for transcriptional and post-transcriptional regulation of ENTs, and the potential consequences for foetal endothelial function in these pathologies. Recent available information regarding functional consequences of an abnormal environment on the functionality of the endothelium from microvasculature of the human placenta is mentioned. The available information is scarce, but it could contribute to a better understanding of the cell and molecular basis of the altered vascular endothelial function in this pathological conditions, emphasizing the key role of this type of epithelium in fetal-placental function and the normal foetal development and growth.

Estudio comparativo de los niveles séricos de magnesio iónico en mujeres no gestantes, gestantes normales y gestantes con preeclampsia / A comparative study of the ionic magnesium serum levcels in non-pregnant, normal pregnant and preeclamptic pregnant women

OBJETIVO: No hay datos respecto al nivel de magnesio iónico sérico en la población peruana y se sabe que durante la gestación disminuyen los niveles de magnesio. El propósito del estudio fue comparar los niveles séricos de magnesio iónico en mujeres de nuestro medio: no gestantes, gestantes normales y gestantes con preeclampsia. MATERIAL Y MÉTODOS: Se realizó un estudio transversal en el Servicio de Obstetricia del Hospital Nacional Arzobispo Loayza en tres grupos de mujeres: 19 no gestantes, 19 gestantesnormales y 16 gestantes con preeclampsia, en las que se midió magnesio iónico en sangre en el laboratorio de la Unidad de CuidadosIntensivos del Hospital Nacional Arzobispo Loayza y se analizaron sus características clínicas. RESULTADOS: La edad fue similar en los tres grupos 24,4 ± 3,6 años (rango: 19 a 33). La hemoglobina fue mayor en no gestantes 12,77 ± 0,84 g/dL que en gestantesnormales 11,9 ± 0,96 g/dL y en preeclámpticas 11,8 ± 0,71 g/dL (p < 0,05). Los niveles de magnesio fueron: 0,51 ± 0,03 mmol/L en no gestante, 0,49 ± 0,03 mmol/L en gestantes normales y 0,46 ± 0,03 mmol/L en preeclámpticas, con diferencia estadística entre los tres grupos (p < 0,05). El porcentaje de hipomagnesemia fue 0%, 5,3% y 37,5% en no gestante, gestantes normales y preeclámpticas, respectivamente. CONCLUSIONES: Las mujeres con preeclampsia tuvieron niveles más bajos de magnesio iónico sérico que las gestantes normales y no gestantes. El porcentaje de hipomagnesemia fue de 37,5% en las pacientes con preeclampsia.

There is no available data on the serum ionic magnesium levels in our population and it is well known that these levels decrease during pregnancy. The purpose of this study was to compare the serumionic magnesium levels in non-pregnant women, women during normal pregnancy and pregnant women with pre eclampsia. MATERIAL AND METHODS: The crossed study was conducted in the Obstetric Departmentof the Hospital Nacional Arzobispo Loayza, Lima, with three groups: 19 non-pregnant women, 19 with normal pregnancy and 16 with preeclamptic pregnancy. In each group, the ionic serum magnesium levels were measured in the Critical Care Unit Laboratory. Their clinical characteristics were analyzed. RESULTS: The age was similar in all three groups: 24,4 ± 3,6 years (range: 19 to 33). The highest hemoglobin level was found in the non-pregnant women group (12,77 ±0,84 g/dL) followed by the normal pregnancy group (11,9 ± 0,96 g/dL)and the preeclamptic pregnancy group (11,8 ± 0,71 g/dL).There was statistical difference (p < 0,05). In a similar manner, the magnesium highest levels were found in the non-pregnant women group (0,51 ± 0,03 mmol/L) followed by the normal pregnancy group (0,49 ± 0,03 mmol/L) and the preeclamptic pregnancy group (0,46 ± 0,03 mmol/L) (p < 0,05). Hypomagnesaemia was found to be 0%, 5,3% and 37,5%, respectively in the non-pregnant, normal pregnant and preeclamptic pregnant women. CONCLUSIONS: Preeclamptic women have lower serum ionic magnesium levels than normal pregnant and non-pregnant women. Hypomagnesemia was found to be 37,5% in preeclamptic pregnant women.