The subcommissural organ of the rat secretes Reissner's fiber glycoproteins and CSF-soluble proteins reaching the internal and external CSF compartments

<p>Abstract</p> <p>Background</p> <p>The subcommissural organ (SCO) is a highly conserved brain gland present throughout the vertebrate phylum; it secretes glycoproteins into the cerebrospinal fluid (CSF), where they aggregate to form Reissner's fiber (RF). SCO-spondin is the major constituent protein of RF. Evidence exists that the SCO also secretes proteins that remain soluble in the CSF. The aims of the present investigation were: (i) to identify and partially characterize the SCO-secretory compounds present in the SCO gland itself and in the RF of the Sprague-Dawley rat and non-hydrocephalic hyh mouse, and in the CSF of rat; (ii) to make a comparative analysis of the proteins present in these three compartments; (iii) to identify the proteins secreted by the SCO into the CSF at different developmental periods.</p> <p>Methods</p> <p>The proteins of the SCO secreted into the CSF were studied (i) by injecting specific antibodies into ventricular CSF <it>in vivo</it>; (ii) by immunoblots of SCO, RF and CSF samples, using specific antibodies against the SCO secretory proteins (AFRU and anti-P15). In addition, the glycosylated nature of SCO-compounds was analysed by concanavalin A and wheat germ agglutinin binding. To analyse RF-glycoproteins, RF was extracted from the central canal of juvenile rats and mice; to investigate the CSF-soluble proteins secreted by the SCO, CSF samples were collected from the cisterna magna of rats at different stages of development (from E18 to PN30).</p> <p>Results</p> <p>Five glycoproteins were identified in the rat SCO with apparent molecular weights of 630, 450, 390, 320 and 200 kDa. With the exception of the 200-kDa compound, all other compounds present in the rat SCO were also present in the mouse SCO. The 630 and 390 kDa compounds of the rat SCO have affinity for concanavalin A but not for wheat germ agglutinin, suggesting that they correspond to precursor forms. Four of the AFRU-immunoreactive compounds present in the SCO (630, 450, 390, 320 kDa) were absent from the RF and CSF. These may be precursor and/or partially processed forms. Two other compounds (200, 63 kDa) were present in SCO, RF and CSF and may be processed forms. The presence of these proteins in both, RF and CSF suggests a steady-state RF/CSF equilibrium for these compounds. Eight AFRU-immunoreactive bands were consistently found in CSF samples from rats at E18, E20 and PN1. Only four of these compounds were detected in the cisternal CSF of PN30 rats. The 200 kDa compound appears to be a key compound in rats since it was consistently found in all samples of SCO, RF and embryonic and juvenile CSF.</p> <p>Conclusion</p> <p>It is concluded that (i) during the late embryonic life, the rat SCO secretes compounds that remain soluble in the CSF and reach the subarachnoid space; (ii) during postnatal life, there is a reduction in the number and concentration of CSF-soluble proteins secreted by the SCO. The molecular structure and functional significance of these proteins remain to be elucidated. The possibility they are involved in brain development has been discussed.</p

Carbon and oxygen in HII regions of the Magellanic Clouds: abundance discrepancy and chemical evolution

We present C and O abundances in the Magellanic Clouds derived from deep spectra of HII regions. The data have been taken with the Ultraviolet-Visual Echelle Spectrograph at the 8.2-m VLT. The sample comprises 5 HII regions in the Large Magellanic Cloud (LMC) and 4 in the Small Magellanic Cloud (SMC). We measure pure recombination lines (RLs) of CII and OII in all the objects, permitting to derive the abundance discrepancy factors (ADFs) for O^2+, as well as their O/H, C/H and C/O ratios. We compare the ADFs with those of other HII regions in different galaxies. The results suggest a possible metallicity dependence of the ADF for the low-metallicity objects, but more uncertain for high-metallicity objects. We compare nebular and B-type stellar abundances and we find that the stellar abundances agree better with the nebular ones derived from collisionally excited lines (CELs). Comparing these results with other galaxies we observe that stellar abundances seem to agree better with the nebular ones derived from CELs in low-metallicity environments and from RLs in high-metallicity environments. The C/H, O/H and C/O ratios show almost flat radial gradients, in contrast with the spiral galaxies where such gradients are negative. We explore the chemical evolution analysing C/O vs. O/H and comparing with the results of HII regions in other galaxies. The LMC seems to show a similar chemical evolution to the external zones of small spiral galaxies and the SMC behaves as a typical star-forming dwarf galaxy.Comment: Accepted for publication in MNRAS, 17 pages, 11 figures, 8 table

El Testimonio del Clérigo Anónimo sobre el Hospital San Juan de Dios en Jerusalén (1177-1187). Traducción, introducción y notas

Desde su origen, la tarea de cuidado y atención a los pobres y a los enfermos definió el sentido y el carácter particular de la Orden de los caballeros hospitalarios de Jerusalén. El emblema de dicha tarea fue el hospital que la orden construyó en Tierra Santa. El Testimonio del Clérigo Anónimo –escrito en algún momento entre los años 1177 y 1187– constituye la descripción in extenso más importante acerca de la tarea médica desarrollada en el Hospital de San Juan. Por tal motivo en este artículo presentamos la primera traducción al español del texto original latino, editado sobre la base del único manuscrito que se conserva de dicho texto (Clm 4620, fols. 132v°-139v°)

El Testimonio del Clérigo Anónimo sobre el Hospital San Juan de Dios en Jerusalén (1177-1187). Traducción, introducción y notas

Desde su origen, la tarea de cuidado y atención a los pobres y a los enfermos definió el sentido y el carácter particular de la Orden de los caballeros hospitalarios de Jerusalén. El emblema de dicha tarea fue el hospital que la orden construyó en Tierra Santa. El Testimonio del Clérigo Anónimo –escrito en algún momento entre los años 1177 y 1187– constituye la descripción in extenso más importante acerca de la tarea médica desarrollada en el Hospital de San Juan. Por tal motivo en este artículo presentamos la primera traducción al español del texto original latino, editado sobre la base del único manuscrito que se conserva de dicho texto (Clm 4620, fols. 132v°-139v°)

On the presence of Heterocarpus ensifer Milne Edwards, 1881 (Decapoda, Pandalidae) in the Spanish Mediterranean

Not

Influence of abiotic factors in the biomass of deep water shrimps, P. longirostris and A. antennatus, off Catalano-Levantine Mediterranean coast of Spain.

Deep-water shrimps show large inter-annual fluctuations in biomass. We analysed the influence of some abiotic factors in these fluctuations using survey data (2006-2009). While P. longirostris biomass was feebly affected by the T-S of the water masses, these factors, particularly salinity, seemed to have a significant effect on A. antennatus a species considered to be stenothermal and stenohaline, whose biomass distribution showed a direct relationship with the Levantine Intermediate Water

Porous Titanium Cylinders Obtained by the Freeze-Casting Technique: Influence of Process Parameters on Porosity and Mechanical Behavior

 The discrepancy between the stiffness of commercially pure titanium and cortical bone  tissue compromises its success as a biomaterial. The use of porous titanium has been widely studied,  however, it is still challenging to obtain materials able to replicate the porous structure of the bones  (content, size, morphology and distribution). In this work, the freeze‐casting technique is used to  manufacture cylinders with elongated porosity, using a home‐made and economical device. The  relationship between the processing parameters (diameter and material of the mold, temperature  gradient), microstructural features and mechanical properties is established and discussed, in terms  of ensuring biomechanical and biofunctional balance. The cylinders have a gradient porosity  suitable for use in dentistry, presenting higher Young’s modulus at the bottom, near the cold spot  and, therefore better mechanical resistance (it would be in contact with a prosthetic crown), while  the opposite side, the hot spot, has bigger, elongated pores and walls.  Ministry of Economy and Competitiveness of Spain  grant  MAT2015‐71284‐P  FEDER‐Junta de Andalucía Research  Project (Modeling and implementation of the freeze casting technique: gradients of porosity with a tribomechanical equilibrium and electro‐stimulated cellular behavior).