La citometría de flujo, un universo de posibilidades en el ámbito veterinario. Revisión

Flow cytometry is a technology that has helped to rapidly advance many diverse areas of science by allowing the simultaneous measurement of multiple characteristics of each of the individual particles or cells in a sample as they pass at high speed through an area illuminated by one or more lasers. The information obtained includes data on the size and internal complexity, as well as other parameters inherent to each of the particles present in the sample, which are captured by the equipment as light signals. The most common particles analyzed in flow cytometers are cells, so the expression of molecules on their surface and inside, viability, functionality, cell proliferation, DNA content, cytokine production and many others can be analyzed. These determinations can be carried out by using antibodies coupled to fluorochromes or by using molecules whose fluorescence depends on the characteristic to be evaluated. Some flow cytometers are also sorters, which means that the equipment can physically sort those cells that exhibit the characteristics of interest; in addition, it is feasible that once they have been purified, they can be used in subsequent experiments. This review focuses on the fundamentals of flow cytometry and its main applications, which offer a great window of opportunity in the veterinary field, both in research and in the clinic.La citometría de flujo es una tecnología que ha favorecido el rápido avance de muchas y muy diversas áreas de la ciencia, ya que permite la medición simultánea de múltiples características de cada una de las partículas o células individuales que se encuentran en una muestra mientras pasan a gran velocidad a través de una zona iluminada por uno o varios láseres. La información obtenida incluye datos sobre el tamaño y la complejidad interna, así como otros parámetros inherentes a cada una de las partículas presentes en la muestra, los cuales son captados por el equipo como señales luminosas. Las partículas más comúnmente analizadas en los citómetros de flujo son células, así que puede analizarse la expresión de moléculas tanto en su superficie como en su interior, la viabilidad, la funcionalidad, la proliferación celular, el contenido de ADN y la producción de citocinas entre muchas otras. Estas determinaciones pueden realizarse gracias a la utilización de anticuerpos acoplados a fluorocromos o bien, al uso de moléculas cuya fluorescencia depende de la característica que se quiera evaluar. Algunos citómetros de flujo son además clasificadores (“sorters”), lo que implica que el equipo puede separar físicamente las células que presentan las características de interés y además, es factible que una vez que han sido purificadas, éstas puedan emplearse en posteriores experimentos. En esta revisión se concentran los fundamentos de la citometría de flujo y sus principales aplicaciones, las cuales ofrecen una gran ventana de oportunidad en el ámbito veterinario, tanto en investigación como en la clínica

Apoptosis: the phenomenon and its determination

La apoptosis es una forma de muerte celular, caracterizada por cambios morfológicos y bioquímicos. En los organismos multicelulares, la homeostasis es mantenida a través de un balance entre la proliferación y la muerte celular, el fenómeno de apoptosis es el principal proceso que mantiene este balance. Alteraciones en la regulación de este tipo de muerte celular pueden contribuir a la patogénesis de ciertas enfermedades como cáncer, infecciones virales, enfermedades autoinmunes y desórdenes neurodegenerativos. Terapias específicas diseñadas para incrementar o disminuir la susceptibilidad de ciertos tipos celulares a morir por apoptosis puede ser la base para el tratamiento de estas enfermedades. Esta es una revisión del fenómeno apoptótico y de algunas técnicas que permiten evidenciarla y cuantificarla.The phenomenon of apoptosis, and a number of techniques for its identification and quantification, are reviewed. Apoptosis is a form of cell death defined by morphological and biochemical characteristics. In multicellular organisms, homeostasis is maintained through a balance between cell proliferation and cell death. The phenomenon of apoptosis is the main process maintaining this balance. Alterations in the apoptosis regulation can contribute to the pathogenesis of a number of diseases including cancer, viral infections, autoimmune diseases and neurodegenerative disorders. Specific therapies designed to enhance or decrease the susceptibility of individual cell types to undergo apoptosis could form the basis for treatment of these diseases

Enfermedades transmitidas por vectores y cambio climático

Socioeconomic changes and health interventions have improved human health worldwide in recent decades. However, changes in the distribution of certain diseases occuring, due mainly to what is known as climate change, a consequence of the deterioration of our environment. One of the concerns arising from this, is the new redistribution or geolocation of Vector-Borne Diseases (VBD) as vectors that transmit them are finding new ecological niches in which to settle and multiply. The aim of this review was to compilate the scientific evidence on climate change and its effects on VBD.Los cambios socioeconómicos y las intervenciones sanitarias han mejorado la salud de la población mundial en las últimas décadas. Sin embargo, han empezado a presentarse modificaciones en la distribución de ciertas enfermedades debidas, principalmente, a lo que se conoce como cambio climático y que es una consecuencia más del deterioro del medio ambiente. Una de las preocupaciones derivadas de lo anterior es la redistribución o nueva geolocalización de las enfermedades transmitidas por vectores (ETV), ya que los vectores que las transmiten están encontrando nuevos nichos ecológicos en los cuales establecerse y multiplicarse. El objetivo de la presente revisión fue conjuntar la evidencia científica en torno al cambio climático y sus efectos en las ETV

Differential Antimicrobial Effect of Essential Oils and Their Main Components: Insights Based on the Cell Membrane and External Structure

The biological activity of essential oils and their major components is well documented. Essential oils such as oregano and cinnamon are known for their effect against bacteria, fungi, and even viruses. The mechanism of action is proposed to be related to membrane and external cell structures, including cell walls. This study aimed to evaluate the biological activity of seven essential oils and eight of their major components against Gram-negative and Gram-positive bacteria, filamentous fungi, and protozoans. The antimicrobial activity was evaluated by determination of the Minimal Inhibitory Concentration for Bacillus cereus, Staphylococcus aureus, Listeria monocytogenes, Escherichia coli, Salmonella Typhimurium, Shigella sonnei, Aspergillus niger, Aspergillus ochraceus, Alternaria alternata, and Fusarium oxysporium, the half-maximal inhibitory concentration (IC50) for Trypanosoma cruzi and Leishmania mexicana, and the median lethal dose (LD50) for Giardia lamblia. Results showed that oregano essential oil showed the best antibacterial activity (66–100 µg/mL), while cinnamon essential oil had the best fungicidal activity (66–116 µg/mL), and both showed excellent antiprotozoal activity (22–108 µg/mL). Regarding the major components, thymol and carvacrol were also good antimicrobials (23–200 µg/mL), and cinnamaldehyde was an antifungal compound (41–75 µg/mL). The major components were grouped according to their chemical structure as phenylpropanoids, terpenoids, and terpinenes. The statistical analysis of the grouped data demonstrated that protozoans were more susceptible to the essential oils, followed by fungi, Gram-positive bacteria, and Gram-negative bacteria. The analysis for the major components showed that the most resistant microbial group was fungi, which was followed by bacteria, and protozoans were also more susceptible. Principal Component Analysis for the essential oils demonstrated the relationship between the biological activity and the microbial group tested, with the first three components explaining 94.3% of the data variability. The chemical structure of the major components was also related to the biological activity presented against the microbial groups tested, where the three first principal components accounted for 91.9% of the variability. The external structures and the characteristics of the cell membranes in the different microbial groups are determinant for their susceptibility to essential oils and their major component

Enfermedades Transmitidas por Vectores y Cambio Climático

<div>Los cambios socioeconómicos y las intervenciones</div><div>sanitarias han mejorado la salud de la población</div><div>mundial en las últimas décadas. Sin embargo,</div><div>han empezado a presentarse modificaciones en</div><div>la distribución de ciertas enfermedades debidas,</div><div>principalmente, a lo que se conoce como cambio</div><div>climático y que es una consecuencia más del</div><div>deterioro del medio ambiente.</div><div><br></div><div>Una de las preocupaciones derivadas de lo</div><div>anterior es la redistribución o nueva geolocalización</div><div>de las enfermedades transmitidas por vectores</div><div>(ETV), ya que los vectores que las transmiten están</div><div>encontrando nuevos nichos ecológicos en los cuales</div><div>establecerse y multiplicarse. El objetivo de la presente</div><div>revisión fue conjuntar la evidencia científica en torno</div><div>al cambio climático y sus efectos en las ETV.</div

Quantitative structure-activity relationship of molecules constituent of different essential oils with antimycobacterial activity against Mycobacterium tuberculosis and Mycobacterium bovis.

<p>Background</p> <p>Essential oils and their constituents are commonly known for their antibacterial, antifungal and antiparasitic activity, and there are also reports on the antimycobacterial properties, but more experimental data are needed for the description of the mechanism of action or structural (and molecular) properties related to the antimicrobial activity.</p> <p>Methods</p> <p>Twenty-five constituents of essential oils were evaluated against Mycobacterium tuberculosisH37Rv and Mycobacterium bovis AN5 by the Alamar Blue technique. Twenty compounds were modeled using in silico techniques descriptor generation and subsequent QSAR model building using genetic algorithms. The p-cymene, menthol, carvacrol and thymol were studied at the quantum mechanical level through the mapping of HOMO and LUMO orbitals. The cytotoxic activity against macrophages (J774A) was also evaluated for these four compounds using the Alamar Blue technique.</p> <p>Results</p> <p>All compounds tested showed to be active antimicrobials against M. tuberculosis. Carvacrol and thymol were the most active terpenes, with MIC values of 2.02 and 0.78 μg/mL respectively. Cinnamaldehyde and cinnamic acid were the most active phenylpropanes with MIC values of 3.12 and 8.16 μg/mL respectively. The QSAR models included the octanol-water partition (LogP) ratio as the molecular property that contributes the most to the antimycobacterial activity and the phenolic group (nArOH) as the major structural element.</p> <p>Conclusions</p> <p>The description of the molecular properties and the structural characteristics responsible for antimycobacterial activity of the compounds tested, were used for the development of mathematical models that describe structure-activity relationship. The identification of molecular and structural descriptors provide insight into the mechanisms of action of the active molecules, and all this information can be used for the design of new structures that could be synthetized as potential new antimycobacterial agents.</p> <p> </p

PD-L1 Expression Induced by the 2009 Pandemic Influenza A(H1N1) Virus Impairs the Human T Cell Response

PD-L1 expression plays a critical role in the impairment of T cell responses during chronic infections; however, the expression of PD-L1 on T cells during acute viral infections, particularly during the pandemic influenza virus (A(H1N1)pdm09), and its effects on the T cell response have not been widely explored. We found that A(H1N1)pdm09 virus induced PD-L1 expression on human dendritic cells (DCs) and T cells, as well as PD-1 expression on T cells. PD-L1 expression impaired the T cell response against A(H1N1)pdm09 by promoting CD8+ T cell death and reducing cytokine production. Furthermore, we found increased PD-L1 expression on DCs and T cells from influenza-infected patients from the first and second 2009 pandemic waves in Mexico City. PD-L1 expression on CD8+ T cells correlated inversely with T cell proportions in patients infected with A(H1N1)pdm09. Therefore, PD-L1 expression on DCs and T cells could be associated with an impaired T cell response during acute infection with A(H1N1)pdm09 virus