Reelin-dependent ApoER2 downregulation uncouples newborn neurons from progenitor cells.

Reelin and its receptor machinery are well known to be required for the migration and positioning of neocortical projection neurons. More recently, reelin has been shown both necessary and sufficient to determine the rate of neocortical neurogenesis. The molecular links underlying its seemingly distinct proliferative and post-proliferative functions remain unknown. Here we reveal an enriched expression of functional reelin receptors, largely of Apolipoprotein E Receptor 2 (ApoER2), in radial glia basal processes and intermediate progenitor cells during mid/late cortical development. In vivo, ApoER2 overexpression inhibits neuronal migration. In contrast, precluding excessive levels of ApoER2 in reelin-deficient cortices, by either ApoER2 knock-down or the transgenic expression of reelin in neural progenitor cells, improves neuronal migration and positioning. Our study provides groundwork for the highly orchestrated clearance of neocortical neurons from their birth site, suggesting that a reelin-dependent ApoER2 downregulation mechanism uncouples newborn neurons from progenitor cells, thereby enabling neurons to migrate.

Dendrimers as vectors for genetic material delivery to the nervous system.

Transfection of genetic material into primary neuronal cultures remains a challenge because of the intrinsic difficulty in transfecting this type of cell. This review covers the recent developments in the use of dendrimers for siRNA and DNA transfection in both neuronal and glial cells. Crossing the blood brain barrier crossing represents a challenge for the effective use of dendrimer-mediated delivery of therapeutic agents to the central nervous system. We will discuss the effectiveness, both in vitro and in vivo, of various dendrimers in delivering genetic material to neural tissue and its ability to cross the blood-brain barrier. In addition, the use of dendrimers as a potential new therapy in the treatment of glioblastoma will be presented.

Role of generation, architecture, pH and ionic strength on successful siRNA delivery and transfection by hybrid PPV-PAMAM dendrimers.

Small interfering RNA (siRNA) constitutes an excellent way of knocking down genes. However, it requires the use of delivery systems to reach the target cells, especially to neuronal cells. Dendrimers are one of the most widely used synthetic nanocarriers for siRNA delivery. However, due to the complexity of the dendrimer-siRNA interactions, when a new dendritic carrier is designed it is difficult to predict its efficiency to bind and to deliver siRNA. At the same time it is not easy to understand the origin of eventual limited functionalities. We have modeled the interactions between two dendrimers (TDG-G1 and TDG-G2) and siRNA using molecular dynamics (MD) simulation. The results were compared to experimental physico-chemical parameters such as siRNA complexation, complex stability, size, and zeta potentials and biological effects such as down-regulation of a specific RNA expression in cortical neurons in culture. Data indicate that the combination of rigid core and flexible branches guarantees strong siRNA binding, which is important to have a good transfection profile. However, the successful nanocarrier for siRNA delivery (TDG-G1) is identified not only by a high affinity for siRNA, but by a favorable equilibrium between a strong binding and the ability to release siRNA to exert its biological action. The conditions under which the dendriplex is formed are also relevant for transfection efficiency and biological activity.

El ABC en la facoemulsificación: facodinamia la energía ultrasónica / The ABC in phacoemulsification: phacodynamics ultrasonic energy

Sobre el tema facoemulsificación se analizan los principales conceptos a tener presente en el manejo de la máquina de faco sobre el módulo de ultrasonido, imprescindibles para la realización de una cirugía, utilizando este proceder quirúrgico(AU)

The main concepts related to phacoemulsification needed for handling the phaco machine about the ultrasonic module and which are indispensable for a surgery using this surgical method are analysed(AU)

Downregulation of functional Reelin receptors in projection neurons implies that primary Reelin action occurs at early/premigratory stages.

Reelin signaling is essential for correct development of the mammalian brain. Reelin binds to apolipoprotein E receptor 2 and very low-density lipoprotein receptor and induces phosphorylation of Dab1. However, when and where these reactions occur is essentially unknown, and the primary function(s) of Reelin remain unclear. Here, we used alkaline phosphatase fusion of the receptor-binding region of Reelin to quantitatively investigate the localization of functional Reelin receptors (i.e., those on the plasma membrane as mature forms) in the developing brain. In the wild-type cerebral cortex, they are mainly present in the intermediate and subventricular zones, as well as in radial fibers, but much less in the cell bodies of the cortical plate. Functional Reelin receptors are much more abundant in the Reelin-deficient cortical plate, indicating that Reelin induces their downregulation and that it begins before the neurons migrate out of the intermediate zone. In the wild-type cerebellum, functional Reelin receptors are mainly present in the cerebellar ventricular zone but scarcely expressed by Purkinje cells that have migrated out of it. It is thus strongly suggested that Reelin exerts critical actions on migrating projection neurons at their early/premigratory stages en route to their final destinations, in the developing cerebral cortex and cerebellum.

Phytoestrogen modulation of bone-related cytokines and its impact on cell viability in human prostate cancer cells.

AIMS: Prostate cancer (PCa) has a high propensity to metastasize to the bone. PCa cells produce several bone-related factors, namely parathyroid hormone related protein (PTHrP), its PTH type 1 receptor (PTH1R), osteoprotegerin (OPG), and receptor activator of NF-kappa B ligand (RANKL). The effects of these factors might explain, at least in part, the ability of PCa cells to grow in and interact with bone. MAIN METHODS: We first analyzed the expression of the aforementioned factors (by western blot and flow cytometry), and their modulation by the phytoestrogens genistein and daidzein (as potential anti-tumoral agents), in human PCa cells in vitro. We also assessed the impact of these osteomimetic factors on PCa cell viability (by propidium iodide staining and flow cytometry, and trypan blue staining). KEY FINDINGS: Genistein and daidzein, at nM range, increased both the PTHrP/PTH1R system and the OPG/RANKL protein ratio, while genistein and, to a lesser extent, daidzein, at >microM doses, inhibited cell viability in PCa cells. Both N- and C-terminal domains of PTHrP inhibited genistein-induced cell death by modulating transcription factor Runx-2 and the Bcl-2/Bax protein ratio in PCa cells. SIGNIFICANCE: Our findings indicate that high doses of genistein and daidzein cause PCa cell death. On the other hand, low doses of these phytoestrogens induce some osteomimetic features in PCa cells with putative impact on PCa development.

[Categorization of adrenergic alpha 1 receptors in detrusor of patients with obstructive BPH. Initial study on experimental animal model]. / Categorización de receptores alpha 1-adrenérgicos en el detrusor de pacientes con HBP obstructiva. Estudio inicial en modelo animal de experimentación.

INTRODUCTION: The action of alpha 1-adrenergic receptor antagonists in ameliorating irritation and obstruction in patients with bladder outlet obstruction (due to Benign Prostatic Hyperplasia-BPH) has been demonstrated. Although it is well known that alpha 1-a receptors are responsible for prostate smooth muscle relaxation, the mechanism by which irritative bladder symptoms are improved is unknown. Different alpha 1 receptor subtypes may be involved. The objective of this study is to investigate the changes in the alpha-adrenergic receptor populations in the obstructed detrusor, and to determine which subtype is proportionally increased in this situation (bladder outlet obstruction). MATERIAL AND METHODS: This was an in vivo study in an experimental model: male NZ (New Zealand) rabbits. The bladder neck of one group of rabbits was obstructed surgically using the technique proposed by Levin et al. Subsequent to bladder catherization with a 8Fr catheter, the bladder neck was exposed by means of a low medial abdominal incision. The bladder neck was tied with a 2/0 silk thread below the ureteral orifices. The catheter was taken out at the end of the intervention. The rabbits were sacrificed after 4 weeks using intracardiac pentothal and cystectomy was performed. A control group that did not undergo bladder obstruction were also sacrificed at this time, for the comparative study. Part of the detrusor was used for a pathological study and the rest for a physio-pharmacological study in which the organ was placed in a bath of adrenoceptor agonists (phenylephrine and noradrenaline) and antagonists WB101, AH11101A and BMY7378 (antagonists of the alpha 1a, b, d, respectively). RESULTS: The findings of the pathological study show that the bladder wall was thicker in the rabbits that underwent bladder obstruction. The physio-pharmacological studies demonstrate that the detrusor response to the selective alpha-1 adrenergic agonist was greater in the rabbits that underwent bladder obstruction, however detrusor contractility was decreased (KPSS). With bladder obstruction the alpha 1d receptors were increased. DISCUSSION AND CONCLUSIONS: Receptor-binding studies (Malloy et al) aim to differentiate the alpha-adrenoreceptor populations. These studies identify and quantitate the different receptor subtypes in tissue without taking into account their activity. The isometric and physio-pharmacological tests evaluate active receptors, i.e. those that respond to agonist and antagonist stimuli. This enables detrusor activity to be evaluated accurately. The results obtained in this investigational study support the hypothesis that there is a high statistically significant increase in the alpha 1 adrenergic receptors in the obstructed detrusor. Furthermore, in agreement with previous molecular studies, during prostate obstruction alpha 1d is the predominate sub-population in the bladder. These findings may have patho-physiological, clinical and pharmacological implications. If this hypothesis which has been demonstrated in an experimental model, is also demonstrated in studies in humans, pharmacological development should not only be focussed on selective alpha 1a receptor antagonists (prostate) but also on those of alpha 1d, for relieving symptoms in patients with bladder outlet obstruction (BPH and prostatism).

Categorización de receptores alfa1-adrenérgicos en el detrusor de pacientes con hbp obstructiva.Estudio inicial en modelo animal de experimentación / Alfa1-Adrenergic receptors categorisation in the detrusor of patients with obstructive bph. Early study in experimental models

INTRODUCCIÓN: Los antagonistas de los receptores adrenérgicos alfa1 han demostrado su acción en pacientes con obstrucción al flujo vesical (Hiperplasia Benigna de Próstata-HBP) al mejorar los síntomas obstructivos e irritativos. Si bien es conocido que los receptores alfa1a son los responsables de la relajación del músculo liso de la próstata, es desconocido el mecanismo por el cual se mejoran los síntomas irritativos de responsabilidad vesical. Diferentes subtipos de receptores alfa1 podrían estar implicados. El objetivo de esta investigación es indagar en los cambios poblacionales de receptores -adrenérgicos en el detrusor obstruido, y determinar que subtipo es el que proporcionalmente aumenta en esta situación (obstrucción vesical al flujo miccional). MATERIAL Y MÉTODOS: El estudio se realiza in vivo en un modelo animal de experimentación: conejos machos NZ (Nueva Zelanda). Un grupo de ellos es obstruido quirúrgicamente, a nivel del cuello vesical, mediante la técnica propuesta por Levin et al.1,2. Previa cateterización vesical con sonda 8Fr, y a través de una incisión media abdominal baja se expone el cuello vesical, que será ligado con una seda de 2/0, por debajo de los orificios ureterales, retirando la sonda al final de esta intervención. Después de 4 semanas se sacrifica el conejo con pentotal intracardiaco y se realiza cistectomía. El grupo control son otros conejos no sometidos a obstrucción vesical que se sacrifican también en este momento para estudio comparativo. Parte del detrusor es sometido a estudio anatomo-patológico y el resto a un estudio fisio-farmacológico en baños de órgano mediante agonistas (phenilefrina y noradrenalina) y antagonistas de adrenoceptores: WB4101, AH11101A y BMY7378, antagonistas respectivos de los receptores alfa1a,b,d. RESULTADOS: Los hallazgos anatomo-patológicos demuestran mayor grosor de la pared de la vejiga en los casos de obstrucción vesical. Los estudios fisio-farmacológicos ponen de manifiesto que la respuesta del detrusor al agonista selectivo alfa1-adrenérgico es mayor en los conejos sometidos a obstrucción vesical, sin embargo la contractilidad del detrusor está disminuida (KPSS). En condiciones de obstrucción son los receptores alfa1d los que se ven aumentados. DISCUSIÓN Y CONCLUSIONES: Los estudios que pretenden diferenciar las distintas poblaciones de alfa-adrenoceptores son estudios de binding (Malloy et al.)3 que localizan y cuantifican los distintos subtipos de receptores presentes en el tejido sin tener en cuenta su actividad. Los ensayos isométricos y fisiofarmacológicos evalúan receptores activos, es decir, que responden a estímulos agonistas y antagonistas, lo que permite valorar con exactitud la actividad del detrusor. Los resultados obtenidos en este estudio de investigación, apoyan la hipótesis del incremento de receptores adrenérgicos alfa1 en el detrusor obstruido con una p altamente significativa, y coincidiendo con trabajos moleculares previos4, durante la obstrucción prostática la subpoblación predominante en la vejiga es la alfa1d. Estos hallazgos pueden tener implicaciones fisiopatológicas, clínicas y farmacológicas. Si esta hipótesis, demostrada en experimentación animal, se consigue demostrar en la fase humana de la investigación, el desarrollo farmacológico deberá localizarse no sólo en fármacos antagonistas selectivos de receptores alfa1a (próstata), sino también de los 1d, con responsabilidad clínica vesical en situación de obstrucción vesical al flujo miccional (HBP y prostatismo) (AU)

[Duloxetine and other tricyclic antidepressants: pharmacodynamic effects in the lower urinary tract]. / Duloxetina y otros antidepresivos tricíclicos: efectos farmacodinámicos en el tracto urinario inferior.

INTRODUCTION: During years the pharmacology of the lower urinary tract function has been presided by the protagonism of the autonomic nervous system and its components, sympathetic and parasympathetic. Recent investigations proved a greater complexity of micturional dynamics, attributing a more important role to the central nervous system (SNC), to the striated sphincter and to the afferent arc, offering a new opportunity to the Tricyclic Antidepressants (T.A.), reason for this general review. MATERIAL AND METHODS: Using as reference the work of the First Consultation on Incontinence (Montecarlo, 1999), the previous and later publications about T.A. have been reviewed, including experimental (isometric and "in vivo" studies) and clinical studies, investigating on pharmacological evidences, mechanism of action, tolerance and other effects of T.A. RESULTS: Only a reduced group of T.A. have been submitted to experimental evaluations and employed in clinical trials. The recent works on Duloxetine have waked up a special interest by their pharmacological potential. CONCLUSIONS: New knowledge on the peripheral and central control of the continence-miction dynamic offer new pathways for the treatment with T.A., whose effectiveness and tolerance are reviewed.

[Cystic adenoid carcinoma. Review of last five years in our ENT department (1987-1991)]. / Carcinoma adenoide quístico. Revisión de los últimos cinco años en nuestro Servicio de O.R.L. (1987-1991).

We present 4 cases of adenoid cystic carcinoma from different locations (parotid, submaxillary, larynx and auditory duct) and we underline the supraglottic origin of one of them. We point out the good clinical behaviour of this carcinoma, with a long tested survival, more than 5 years, in 2 of our cases. All of them showed morphological features independently of the sitting.

[Nasal angiofibroma in an adult]. / Angiofibroma nasal. A propósito de un caso de presentación en la edad adulta.

We have studied a nasal Angiofibroma in a 71-years-old male, who had not undergone any male-hormonal-therapy. The age of occurrence and the clinical course of this case made the tumor very unlikely to be a silent puberal nasal angiofibroma. After morphologic exam and exclusion of other bleeding entities of the nasal cavity we arrived at the diagnosis of nasal angiofibroma. We believe that this tumor might be arisen "ex novo" and that the nasal angiofibroma of elderly people might be a new entity.

[Tuberculosis of the parotid gland]. / Tuberculosis parotídea.

We present a case of parotid tuberculosis diagnosed through F.N.A.C. (fine needle aspiration cytology). Due to this rare extrapulmonary location of the tuberculosis, the AA. make a review of the last 12 years concerning literature together with a monographic study of the process.