Imaging the electrical activity of organelles in living cells.

Eukaryotic cells are complex systems compartmentalized in membrane-bound organelles. Visualization of organellar electrical activity in living cells requires both a suitable reporter and non-invasive imaging at high spatiotemporal resolution. Here we present hVoSorg, an optical method to monitor changes in the membrane potential of subcellular membranes. This method takes advantage of a FRET pair consisting of a membrane-bound voltage-insensitive fluorescent donor and a non-fluorescent voltage-dependent acceptor that rapidly moves across the membrane in response to changes in polarity. Compared to the currently available techniques, hVoSorg has advantages including simple and precise subcellular targeting, the ability to record from individual organelles, and the potential for optical multiplexing of organellar activity.

Determinantes económicos en la incidencia de tuberculosis en México / Economic determinants in the incidence of tuberculosis in Mexico

Resumen Introducción La tuberculosis es la causa principal de muerte por un solo agente infeccioso en el mundo. Anualmente, ocurren 10 millones de casos nuevos y más del 95% en países en vías de desarrollo; este problema de salud se vincula a las condiciones sociales y económicas de la población. Objetivo Analizar la relación entre el gasto en salud y la pobreza con la incidencia de tuberculosis en México. Material y métodos Investigación no experimental en el que se analizan reportes económicos y epidemiológicos de tuberculosis de México, periodo 2009-2015. Resultados El producto interno bruto (PIB) de México creció 45% en 2014 con relación al año 2009. El porcentaje del PIB invertido en salud disminuyó desde 2009, pasando de 6.2 a 5.9% en 2015. La población en pobreza aumentó de 2010 a 2014, de 46.1 a 46.2%; la pobreza extrema disminuyó de 11.3 a 9.5%. En 2015, se diagnosticaron 20,561 casos nuevos de tuberculosis, con una incidencia de 17 casos por cada 100,000 habitantes, incrementando dos décimas con relación al año previo. Conclusión El incremento de la incidencia de tuberculosis en México se relaciona con las condiciones socioeconómicas de la población. Las políticas públicas deberán atender los determinantes sociales.

Abstract Introduction Tuberculosis, the main cause of death by a single infectious agent in the world. Annually there are 10 million new cases and more than 95% in developing countries; this health problem is linked to the social and economic conditions of the population. Objective To analyze the relationship between health spending and poverty with the incidence of tuberculosis in Mexico. Material and methods Non-experimental research, analyzing economic and epidemiological reports of tuberculosis in Mexico, period 2009-2015. Results Mexico's Gross Domestic Product (GDP) grew 45% in 2014 compared to 2009. The percentage of GDP invested in health decreased since 2009, from 6.2 to 5.9% in 2015. The population in poverty increased from 2010 to 2014, from 46.1 to 46.2%; extreme poverty decreased from 11.3 to 9.5%. In 2015, 20,561 new cases of tuberculosis were diagnosed, with an incidence of 17 cases per 100,000 inhabitants, increasing two tenths in relation to the previous year. Conclusion The increase in the incidence of tuberculosis in Mexico is related to the socioeconomic conditions of the population. Public policies must address social determinants.

Endoplasmic reticulum proteostasis impairment in aging.

Perturbed neuronal proteostasis is a salient feature shared by both aging and protein misfolding disorders. The proteostasis network controls the health of the proteome by integrating pathways involved in protein synthesis, folding, trafficking, secretion, and their degradation. A reduction in the buffering capacity of the proteostasis network during aging may increase the risk to undergo neurodegeneration by enhancing the accumulation of misfolded proteins. As almost one-third of the proteome is synthetized at the endoplasmic reticulum (ER), maintenance of its proper function is fundamental to sustain neuronal function. In fact, ER stress is a common feature of most neurodegenerative diseases. The unfolded protein response (UPR) operates as central player to maintain ER homeostasis or the induction of cell death of chronically damaged cells. Here, we discuss recent evidence placing ER stress as a driver of brain aging, and the emerging impact of neuronal UPR in controlling global proteostasis at the whole organismal level. Finally, we discuss possible therapeutic interventions to improve proteostasis and prevent pathological brain aging.

A TRP conductance modulates repolarization after sensory-dependent depolarization in Chlamydomonas reinhardtii.

Sensory integration is vital for motile organisms constantly exposed to changing surroundings. Chlamydomonas reinhardtii is a single-celled green alga found swimming in freshwater. In this type of alga, sensory input is first detected by membrane receptors located in the cell body, and then transduced to the beating cilia by membrane depolarization. Many components of the machinery associated with sensory integration in C. reinhardtii, such as chemoreceptors and repolarization-associated channels, are yet uncharacterized. TRP channels are known mediators for cellular sensing in animal cells and it has been suggested that the C. reinhardtii genome encodes for a set of TRP proteins. Here, by combining behavioral studies with electrophysiological experiments conducted on both population and single alga, we test whether TRP channel blockers affect algal swimming behavior. Our results suggest that a TRP conductance is associated to the repolarization that follows a depolarizing receptor potential, highlighting a primitive function of TRP proteins.

A cell-free assay to determine the stoichiometry of plasma membrane proteins.

Plasma membrane receptors, transporters, and ion channel molecules are often found as oligomeric structures that participate in signaling cascades essential for cell survival. Different states of protein oligomerization may play a role in functional control and allosteric regulation. Stochastic GFP-photobleaching (SGP) has emerged as an affordable and simple method to determine the stoichiometry of proteins at the plasma membrane. This non-invasive optical approach can be useful for total internal reflection of fluorescence microscopy (TIRFM), where signal-to-noise ratio is very high at the plasma membrane. Here, we report an alternative methodology implemented on a standard laser scanning confocal microscope (LSCM). The simplicity of our method will allow for its implementation in any epifluorescence microscope of choice.

Near-membrane dynamics and capture of TRPM8 channels within transient confinement domains.

BACKGROUND: The cold and menthol receptor, TRPM8, is a non-selective cation channel expressed in a subset of peripheral neurons that is responsible for neuronal detection of environmental cold stimuli. It was previously shown that members of the transient receptor potential (TRP) family of ion channels are translocated toward the plasma membrane (PM) in response to agonist stimulation. Because the spatial and temporal dynamics of cold receptor cell-surface residence may determine neuronal activity, we hypothesized that the movement of TRPM8 to and from the PM might be a regulated process. Single particle tracking (SPT) is a useful tool for probing the organization and dynamics of protein constituents in the plasma membrane. METHODOLOGY/PRINCIPAL FINDINGS: We used SPT to study the receptor dynamics and describe membrane/near-membrane behavior of particles containing TRPM8-EGFP in transfected HEK-293T and F-11 cells. Cells were imaged using total internal reflection fluorescence (TIRF) microscopy and the 2D and 3D trajectories of TRPM8 molecules were calculated by analyzing mean-square particle displacement against time. Four characteristic types of motion were observed: stationary mode, simple Brownian diffusion, directed motion, and confined diffusion. In the absence of cold or menthol to activate the channel, most TRPM8 particles move in network covering the PM, periodically lingering for 2-8 s in confined microdomains of about 800 nm radius. Removing cholesterol with methyl-beta-cyclodextrin (MßCD) stabilizes TRPM8 motion in the PM and is correlated with larger TRPM8 current amplitude that results from an increase in the number of available channels without a change in open probability. CONCLUSIONS/SIGNIFICANCE: These results reveal a novel mechanism for regulating TRPM8 channel activity, and suggest that PM dynamics may play an important role in controlling electrical activity in cold-sensitive neurons.

Structural and textural evolution during folding of layers of layered double hydroxides.

Layers of a layered double hydroxide, containing aluminum 4-fold coordinated, were partially folded in order to obtain a fibrous hydrotalcite-like compound. The hydrotalcite layers, in the presence of an anionic surfactant (sodium dodecyl sulfate) after hydrothermal treatment for 2 weeks, acquire a mesoporous-like arrangement. The transformation was monitored by techniques sensitive to structural and textural properties. Results suggest that brucite-like layers can be joined throughout unsaturated coordinated aluminum, that is, tetrahedral aluminum which links through hydrogen bonds to form aluminum octahedrally coordinated. The fractal dimension parameter was very sensitive to evolution from layered to fibrous hydrotalcites.

Passivation of the calcite surface with phenylmalonate and benzylmalonate ions.

We explored the affinity of calcite to adsorbed organic molecules as an approach to the conservation of cultural heritage built of marble and limestone. The utilization of phenylmalonic and benzylmalonic acids provided a hydrophobic adsorptive interface, adequate to prevent processes of aqueous weathering. Samples of marble powder (polycrystalline calcite) were impregnated with solutions of phenylmalonic and benzylmalonic acid at three concentrations (5 x 10(-2), 5 x 10(-3), and 5 x 10(-4) M) and different pH values (6.00, 7.00, and 8.00). The surface charge of the calcite suspensions was determined by potentiometric measurements under equilibrium conditions at room temperature in aqueous solution of the dicarboxylic acids, in order to understand the influence of the electrokinetic potential in the surface association. The adsorbed amounts were determined by calculation of the thermodynamic equilibria of solutions. The presence of the organic interface on the mineral surface was corroborated by Raman spectroscopy and small-angle X-ray scattering (SAXS). The results indicate effective adsorption of both dicarboxylic acids as a function of the concentration and pH, and several other conditions that favors coulombic interaction, an absence of electrophoretic mobility or surface electroneutrality related to the solid surface potentials. The coverage of pores by dicarboxylic adsorbate modified the geometrical pore shape and the pore size distribution, filling all the pores of larger than 80 A diameter, giving as a result a mesoporous structure. This change in the surface morphology by organic adsorbates constitutes a modification in the diffusional processes of the environment on the mineral surface.

[Search of Chlamydia trachomatis in 159 women from private consultation]. / Búsqueda de Chlamydia trachomatis en 159 mujeres en la consulta privada.

BACKGROUND: Chlamydia trachomatis infection is very common and is associated with recurring cervicovaginitis, pelvic inflammatory disease, abortion and ectopic pregnancy. It may cause sterility. OBJECTIVE: To determine Chlamydia trachomatis frequency at outpatient consultation. PATIENTS AND METHODS: One hundred fifty-nine patients were retrospectively evaluated at the gynecology consultation, to whom an endocervical specimen was taken with a cotton swab to corroborate the presence of Chlamydia trachomatis immunofluorescent antibodies. RESULTS: Forty-nine out of 159 cases (28.9%) were positive to Chlamydia trachomatis. After dividing by subgroups, 26 out of 100 women with cervicovaginitis were positive (26%). Eleven out of 41 cases with pelvic inflammatory disease were positive (26.8%). In 14 patients with recent abortion, 7 were positive (50%) and 2 out of 4 with ectopic pregnancy were positive (50%). CONCLUSIONS: Chlamydia trachomatis detection in patients with cervicovaginitis, pelvic inflammatory disease, ectopic pregnancy and abortion will allow an appropriate treatment to avoid progressive damage and its sequelae to the female genital tract, reproductive and economic levels.

Passivation of the calcite surface with malonate ion.

Samples of polycrystalline calcite were impregnated with solutions of malonic acid of three concentrations (5 x 10(-2), 5 x 10(-3) , and 5 x 10(-4) M) and different pH values (6.00, 7.00, and 8.00). The impregnation was carried out at room temperature to evaluate the adsorption of malonate ion in the calcite surface to optimize the conditions for possible application on limestone and marble in cultural heritage materials. The affinity of the malonate ion was determined through the potentiometric measurement of the surface charge and the corresponding adsorbed amounts by titration, Raman spectroscopy, and small-angle X-ray scattering (SAXS). The results indicate effective adsorption of the malonate ion on the surface at a pH value close to the point of zero charge (pHpzc approximately 8.20) and changes in some surface morphological properties such as the pore shape and the pore size distribution. The presence of a malonate adsorptive layer on calcite generates an interface interaction potential that may influence the reaction and transport mechanisms within the medium.

Cierre de la piel con cianocrilato en las cesáreas / Closure of the skin with cyanocrilate in cesarean section

Se determinó la utilidad del cianocrilato en el cierre de heridas de cesárea, en comparación con las suturas usuales seda y dermalón. Se estudiaron 74 pacientes a las que se les practicó cesárea, sin antecedentes de cirugía previa abdominal e infección. Se dividieron en dos grupos: Uno en el que se utilizó el cianocrilato para cerar la piel en incisiones media y Pfannenstiel con 44 pacientes y otro de control de 30 pacientes con sutura de seda o dermalón. Las características de la población no mostraron diferencias. Los parámetros evaluados fueron: dolor leve a moderado (similar en ambos grupos), prurito (predominó en el grupo cianocrilato [CIAN] 18.1 por ciento por 13.2 por ciento del control); las marcas en la piel predominaron ampliamente en el control con seda (75 por ciento) y ninguna en el CIAN. La reacción a cuerpo extraño fue mayor en el CIAN con 15.9 por ciento por 6.6 por ciento del control. Dehiscencia superficial 6 por ciento del CIAN por 10 por ciento del control. Hematoma 2.2 por ciento del CIAN por 6.6 del control. Bordes mal coaptados 4.5 por ciento del CIAN por 3.3 por ciento del control. Dermatitis-eritema 4.5 por ciento del CIAN y 20 por ciento del control. El tiempo promedio de cierre de la piel en el CIAN fue 62.8 segundo, por 283 del control. El uso de cianocrilato en el cierre de las heridas por cesárea mostró: eficacia, seguridad, reducción en el tiempo quirúrgico, se mejoró la estética de la cicatriz y se redujeron los costos