HSV-1 and endogenous retroviruses as risk factors in demyelination

Herpes simplex virus type 1 (HSV-1) is a neurotropic alphaherpesvirus that can infect the peripheral and central nervous systems, and it has been implicated in demyelinating and neurodegenerative processes. Transposable elements (TEs) are DNA sequences that can move from one genomic location to another. TEs have been linked to several diseases affecting the central nervous system (CNS), including multiple sclerosis (MS), a demyelinating disease of unknown etiology influenced by genetic and environmental factors. Exogenous viral transactivators may activate certain retrotransposons or class I TEs. In this context, several herpesviruses have been linked to MS, and one of them, HSV-1, might act as a risk factor by mediating processes such as molecular mimicry, remyelination, and activity of endogenous retroviruses (ERVs). Several herpesviruses have been involved in the regulation of human ERVs (HERVs), and HSV-1 in particular can modulate HERVs in cells involved in MS pathogenesis. This review exposes current knowledge about the relationship between HSV-1 and human ERVs, focusing on their contribution as a risk factor for MS

Preparation and Loading with Rifampicin of Sub-50 nm Poly(ethyl cyanoacrylate) Nanoparticles by Semicontinuous Heterophase Polymerization

We report the preparation of poly(ethyl cyanoacrylate) (PECA) nanoparticles by semicontinuous heterophase polymerization carried out at monomer starved conditions at three monomer addition rates. Particles in the nanometer range were obtained, the size of which diminishes with decreasing monomer addition rate as shown by the fact that particles with mean diameters of ca. 42 and 30 nm were obtained at the faster and intermediate dosing rates, respectively, whereas two populations of particles, one of 15.5 and the other of 36 nm in mean diameters, were produced at the slower dosing rate. The obtained molecular weights were from 2,200 to 3,500 g/mol, depending on the addition rate, which are typical of the anionic polymerizations of cyanoacrylates in aqueous dispersions at low pHs. The rifampicin (RIF) loading into the nanoparticles was successful since the entire drug added was incorporated. The drug release study carried out at pH of 7.2 indicated a faster release from the free RIF at intermediate and larger release times as expected since, in the nanoparticles, first the drug has to diffuse through the nanoparticle structure. The comparison of several drug release models indicates that the RIF release from PECA nanoparticles follows that of Higuchi

Harmonic states for the free particle

Different families of states, which are solutions of the time-dependent free Schr\"odinger equation, are imported from the harmonic oscillator using the Quantum Arnold Transformation introduced in a previous paper. Among them, infinite series of states are given that are normalizable, expand the whole space of solutions, are spatially multi-localized and are eigenstates of a suitably defined number operator. Associated with these states new sets of coherent and squeezed states for the free particle are defined representing traveling, squeezed, multi-localized wave packets. These states are also constructed in higher dimensions, leading to the quantum mechanical version of the Hermite-Gauss and Laguerre-Gauss states of paraxial wave optics. Some applications of these new families of states and procedures to experimentally realize and manipulate them are outlined.Comment: 21 pages, 3 figures. Title changed, content added, references adde

Kinetic and functional properties of human mitochondrial phosphoenolpyruvate carboxykinase

The cytosolic form of phosphoenolpyruvate carboxykinase (PCK1) plays a regulatory role in gluconeogenesis and glyceroneogenesis. The role of the mitochondrial isoform (PCK2) remains unclear. We report the partial purification and kinetic and functional characterization of human PCK2. Kinetic properties of the enzyme are very similar to those of the cytosolic enzyme. PCK2 has an absolute requirement for Mn2+ ions for activity; Mg2+ ions reduce the Km for Mn2+ by about 60 fold. Its specificity constant is 100 fold larger for oxaloacetate than for phosphoenolpyruvate suggesting that oxaloacetate phosphorylation is the favored reaction in vivo. The enzyme possesses weak pyruvate kinase-like activity (kcat=2.7 s-1). When overexpressed in HEK293T cells it enhances strongly glucose and lipid production showing that it can play, as the cytosolic isoenzyme, an active role in glyceroneogenesis and gluconeogenesis

Comportamiento de 13 modelos de cinta de riego en condiciones de invernadero con agua regenerada

El objetivo de este trabajo ha sido seleccionar modelos de cinta de riego con una mejor adaptación a las condiciones de invernadero y riego con aguas regeneradas. Se ha evaluado el comportamiento de 13 modelos comerciales de cintas de riego seleccionados de entre los más utilizados en los cultivos hortícolas al aire libre, y aquellos que, las empresas instaladoras y fabricantes consideren que, por sus características, pueden tener un buen comportamiento con este tipo de aguas. En la evaluación de campo todos los emisores han presentado valores de uniformidad elevados al comienzo de la campaña de riego. Cinco de las cintas se clasifican como excelentes y el resto como buenas. Al finalizar las 114 horas de trabajo decae sustancialmente la uniformidad. El comportamiento tras la finalización de la primera campaña de riego se puede considerar equiparable al obtenido en un estudio previo con una selección de 20 emisores en ramal convencional y este tipo de aguas. Se puede concluir que las cintas de riego localizado pueden ser una alternativa a los ramales de riego convencionales cuando se riega con aguas residuales urbanas regeneradas, siempre que se elija un material de una mínima calidad y el ratio de sustitución garantice una uniformidad alta

Examen coproparasitológico en niños: comparación de resultados obtenidos por dos métodos en dos instituciones de Santafé de Bogotá, D.C.

This survey was carried out in order to compare the frequency of intestinal parasite detection by direct wet film in stool specimens from children done simultaneously at the Hospital Infantil Lorencita Villegas de Santos (HILVS) and at the Parasitology Department of the Instituto Nacional de Salud (INS). The usefulness of tao methods for the detection of intestinal parasites in the same institution (INS) was compared - direct wet examination and concentration by the formalin-ethersedimentation technique, Four hundred and eighty seven faecal samples of children were taken randomly from 2,954 received at HILVS during six months. A fraction of each sample was sent from the hospital to INS for its parasitological examination. Later on, 305 out of 398 clinical records belonging to children whose stools had been examined every day during three consecutive days, were retrospectively reviewed to describe some demographic factors and the possible signs and symptoms which necessitated the stool examination. The signs and symptoms found by the revision of the clinical records did not necessarily correspond to those associated with intestinal parasites. I No parasites were detected in two hundred and seventy seven (56.9%) samples. Of the two hundred and ten (43.1%) positive samples, pathogenic parasites were found in ninety three (19.1%) The concordance between the examination of faeces at HILVS and INS was measured by the Kappa index. The strength of agreement was almost perfect for Giardia lamblia, substantial for Trichomonas hominis, moderate for lodamoeba bütschliiand Entamoeba coli, fair for Endolimax nana, Trichuris trichiura and Blastocystis hominis, slight for Entamoeba histolytica and poor for Entamoeba hartmanni. The sensitivity and specificity values obtained from direct wet examination and the forrnalin-ether sedimentation technique showed a greater identification of parasites by the concentration method. Nevertheless, there is overlapping between the upper limit of the confidence interval for the direct wet mount and the lower limit of the confidence interval for the formalin-ether sedimentation technique. It is therefore not possible to conclude that the sensitivity of the concentration method is better than that of the direct wet mount. The overall and specific prevalences of parasites were lower than those reported by the National morbidity survey on intestinal parasitism. The study emphasizes the following topics: 1) the need to set up guidelines and precise indications for ordering faecal examinations in order to avoid loss of time and money; 2) the importance of the accuracy of the diagnostic methods, and 3) the need to establish precise morphological criteria for the correct identification of parasites at any laboratory.Con el fin de comparar la frecuencia de hallazgo de parásitos intestinales en niños, mediante el examen directo realizado en una entidad hospitalaria de tercer nivel, el Hospital Infantil Lorencita Villegas de Santos (HILVS) y en una institución de referencia, el Instituto Nacional de Salud (INS), Grupo de Parasitología, y confrontarlo con el método de concentración en formol-éter practicado en el INS, se tomaron al azar 487 muestras de materia fecal de las 2.954 recibidas en el laboratorio de la entidad hospitalaria durante un período de seis meses. Estas muestras fueron fraccionadas para su remisión al laboratorio de parasitología de la entidad de referencia. Posteriormente, se revisaron las historias clínicas de 305 de los 398 niños cuyas muestras (coprológicos seriados) fueron analizadas, para describir las variables demográficas y las posibles indicaciones de solicitud del examen. Sin embargo, éstas no representaron necesariamente la sintomatología asociada con los parásitos. Se encontraron 277 (56,9%) muestras negativas y 210 (43,1%) positivas para por lo menos un parásito, siendo 93 de ellas (19,1%) positivas para algún patógeno. El grado de concordancia entre la entidad hospitalaria y la institución de referencia se determinó utilizando el índice Kappa. La concordancia en la identificación de los parásitos fue casi perfecta con Giardia lamblia, notable con Trichomonas hominis, moderada con lodamoeba bütschlii y Entamoeba col, regular con Endolimax nana, Trichuris trichiura y Blastocystis hominis, mala con Entamoeba histolytica y nula con Entamoeba hartmanni. Lacomparación de los valores de sensibilidad y especificidad obtenidos de la evaluación del examen directo y el método de concentración formol-éter del examen coproparasitológico, mostró una mayor detección de parásitos con el método de concentración. Sin embargo, por la superposición de los valores del límite superior de la sensibilidad del primero (directo) con los del límite inferior de sensibilidad del segundo (concentración), no pudo establecerse la existencia de esta ventaja

Calibration and validation of an algorithm for remote sensing of turbidity over La Plata river estuary, Argentina

The La Plata River, located at 35°S on the Atlantic coast, is one of the largest waterways of South America. It carries a large amount of suspended particulate and dissolved organic matter, and is considered among the most turbid waters of the world. Very high values of total suspended matter have been reported in this region, with mean values ranging from 100 to 300 g m-3 and extreme concentrations up to 400 g m-3. Satellite sensors have shown to be the best tools available to map river plumes and to study their influence on the adjacent ocean. However, global algorithms for remotely estimating sediment concentration are not currently available. Moreover, such high sediment loads represent a challenge to atmospheric correction algorithms which usually rely on the assumption of zero water-leaving reflectance in the near infrared or short wave infrared part of the spectrum (black pixel assumption). In the extremely turbid waters of La Plata Estuary such assumptions are not valid. A two band algorithm to estimate turbidity using near infrared and the short wave infrared bands (858 nm and 1240 nm) of the MODIS-Aqua sensor is presented. The model is calibrated using in situ reflectance and turbidity measurements from turbid waters of the Southern North Sea and Scheldt River (Belgium) and then applied to MODIS imagery of La Plata River estuary (Argentina). A good correlation was found between modelled and in situ turbidity values when the algorithm was applied to concurrent MODIS imagery. Moreover, satellite-derived turbidity maps show a spatial distribution of sediment consistent with patterns and characteristic features of the estuary

Observational Study of the Multistructured Planetary Nebula NGC 7354

We present an observational study of the planetary nebula (PN) NGC 7354 consisting of narrowband Halpha and [NII]6584 imaging as well as low- and high-dispersion long-slit spectroscopy and VLA-D radio continuum. According to our imaging and spectroscopic data, NGC 7354 has four main structures: a quite round outer shell and an elliptical inner shell, a collection of low-excitation bright knots roughly concentrated on the equatorial region of the nebula, and two symmetrical jet-like features, not aligned either with the shells' axes, or with each other. We have obtained physical parameters like electron temperature and electron density as well as ionic and elemental abundances for these different structures. Electron temperature and electron density slightly vary throughout the nebula. The local extinction coefficient c_Hbeta shows an increasing gradient from south to north and a decreasing gradient from east to west consistent with the number of equatorial bright knots present in each direction. Abundance values show slight internal variations but most of them are within the estimated uncertainties. In general, abundance values are in good agreement with the ones expected for PNe. Radio continuum data are consistent with optically thin thermal emission. We have used the interactive three-dimensional modeling tool SHAPE to reproduce the observed morphokinematic structures in NGC 7354 with different geometrical components. Our SHAPE model is in very good agreement with our imaging and spectroscopic observations. Finally, after modeling NGC 7354 with SHAPE, we suggest a possible scenario for the formation of the nebula.Comment: Accepted for publication in AJ, 12 pages, 8 figure