Multi-methodological investigation of the variability of the microstructure of HPMC hard capsules.

The objective of this study was to analyze differences in the subtle microstructure of three different grades of HMPC hard capsule shells using mechanical, spectroscopic, microscopic and tomographic approaches. Dynamic mechanical analysis (DMA), thermogravimetric analysis (TGA), vibrational spectroscopic, X-Ray scattering techniques as well as environmental scanning electron microscopy (ESEM) and optical coherence tomography (OCT) were used. Two HPMC capsules manufactured via chemical gelling, one capsule shell manufactured via thermal gelling and one thermally gelled transparent capsule were included. Characteristic micro-structural alterations (associated manufacturing processes) such as mechanical and physical properties relevant to capsule performance and processability were thoroughly elucidated with the integration of data obtained from multi-methodological investigations. The physico-chemical and physico-mechanical data obtained from a gamut of techniques implied that thermally gelled HPMC hard capsule shells could offer an advantage in terms of machinability during capsule filling, owing to their superior micro- and macroscopic structure as well as specifically the mechanical stability under dry or humid conditions.

Osteopontin inhibits osmotic swelling of retinal glial (Müller) cells by inducing release of VEGF.

Osmotic swelling of retinal neurons and glial cells is an important pathogenic factor of retinal edema formation. Here, we show that the neuroprotective factor osteopontin (OPN), which is released from retinal glial (Müller) cells after stimulation of the cells with glial cell line-derived neurotrophic factor (Del Río et al., 2011, Glia 59:821-832), inhibits the swelling of rat Müller cells induced by hypoosmotic exposure of retinal slices in the presence of barium ions and H2O2, respectively, and in slices of postischemic retinas. OPN did not inhibit the hypoosmotic swelling of bipolar cells in slices of control and postischemic retinas. The inhibitory effect of OPN on Müller cell swelling was dose-dependent, with a half-maximal effect at ∼0.6 ng/ml. The effect of OPN was abrogated in the presence of pharmacological blockers of vascular endothelial growth factor (VEGF) receptor-2, metabotropic glutamate receptors, and purinergic receptors (P2Y1, adenosine A1 receptors), as well as of a neutralizing anti-VEGF antibody. The data suggest that OPN induces the release of VEGF, glutamate, ATP, and adenosine from Müller cells. The effect of OPN was also prevented by blockers of voltage-gated sodium channels (tetrodotoxin), T-type voltage-gated calcium channels (kurtoxin), potassium channels (clofilium), and chloride channels 5-nitro-2-(3-phenylpropylamino)benzoic acid (NPPB). The swelling-inhibitory effect of OPN was dependent on intracellular calcium signaling, activation of phospholipase C and protein kinase C, and vesicular exocytosis of glutamate. In retinal slices, Müller glial cells display immunoreactivity of OPN. The data suggest that Müller cell-derived OPN has (in addition to the effects on photoreceptors and retinal neurons) autocrine effects. The neuroprotective effects of OPN may be in part mediated by the prevention of cytotoxic Müller cell swelling and the release of VEGF and adenosine from Müller cells.

Alteraciones teleradiográficas craneocervicomandibular en pacientes con desplazamiento anterior de disco con reducción / Teleradiographic craneum-cervic-mandibular disorders in patients with disc displacements wirth reduction

Objetivo: Determinar las alteraciones teleradiográficas craneocervicales en pacientes con desplazamiento anterior de disco con reducción. Método: Se realizó un estudio no experimental descriptivo. Se evaluaron 439 pacientes entre 5 y 73 años que consultaron al adontólogo en los consultorios de Talca-Chile, por causa dental. Se extrajo la muestra por conveniencia, quedando constituido un grupo de estudio (pacientes con desplazamiento anterior de disco con reducción (DADR) y un grupo control (sanos), con 25 pacientes cada uno. Se realizó una evaluación clínica a cada grupo y luego se les efectuó una teleradiografía de perfil, la cual fue analizada cefalométricamente a través del análisis propuesto por Mariano Rocabado para investigar las variables de rotación posterior de cráneo y espacios cráneocervicales. Para analizar la lordosis cervical se utilizó el índice de Ishihara. Los resultados se analizaron en forma descriptiva a través de porcentaje. Resultados: De acuerdo a la hipótesis planteada se observó que el 80 por ciento de los pacientes del grupo de estudio presentó un ángulo cráneo vertebral (ACV) alterado del cual el 60 por ciento correspondió a una rotación posterior de cráneo (RPC) y el 40 por ciento una rotación anterior de cráneo (RAC). En relación al índice de Ishihara (ICC), se encontró que el 16 por ciento del grupo control y el 28 por ciento del grupo en estudio presentó un ICC alterado. Conclusión: Existe una tendencia y no un patrón absoluto, entre una alteración del ACV y el DADR. No se encontró relación directa entre el ICC y el DADR

[Measurement procedures for determining the switch-off dose in mammographic equipment]. / Messverfahren für die Bestimmung der Abschaltdosis an Mammographiegeräten.

The usual measurement of the switchoff dose direct on x-ray film plane cannot be employed in mammography equipment without interfering with the switching device, because the chamber for monitoring the automatic exposure is situated behind the film holder and one cannot eliminate the film holder since it is an equipment-specific absorber. We are therefore presenting a method which allows to determine the switchoff dose on x-ray film plane via determination of the attenuating factor of the equipment (influenced by scattered radiation) and the phantom exit dose measured before the compression plate, the film holder having been pushed into position. The ratio of phantom influx to exit dose, standardised for a standard distance, serves additionally to easily recognise major deviations of the x-ray tube voltage from the adjusted value.