Meningo-encéfalo-mielitis provocada por el virus del moquillo : 5 casos clínicos

En este artículo se revisan las meningo-encéfalo-mielitis provocadas por el virus del moquillo (CDV) mediante la presentación de 5 casos clínicos. Todos ellos tienen en común que son perros adultos viejos vacunados y la mayoría no presentaron previamente signos multisistémicos.The authors review canine distemper encephalomyelitis and they describe 5 clinical cases. All of them are vaccinated adult-old dogs and most of them did not present previously multisystemic signs

Ependimoma medular en un perro

Se presentó a nuestro hospital una hembra cruzada de 10 kg. de peso y diez años de edad con signos de tetraplejia. Esta sintomatología se desarrolló en un curso de unos diez días. La exploración neurológica localizó la lesión en los segmentos medulares cérvico-torácicos. En la mielografía se observó una imagen intramedular que se detenía a nivel de C6. La histopatología nos dio el diagnóstico definitivo.A ten-year-old intact female mixed-breed dog was presented with signs of tetraplegia. These neurological signs were developed in a course of ten days. The neurologyc examination localized the lession in the cervico-thoracic spinal cord segments. In the myelogram we found an intramedullary image that stopped the contrast medium at C6 level. The histopathology gave us the definitive diagnosis

Linfoma epidural : un caso clínico

Presentamos un caso clínico de linfoma extranodal con afección neurológica y ocula

Enfermedad vascular cerebral : 9 casos clínicos

En este trabajo se pretende hacer una revisión de la anatomía y fisiopatlogía de los problemas vasculares a los que puede verse sometido en encéfalo mediante la exposición de 9 casos clínicos diagnosticados entre noviembre del 2002 y diciembre del 2005.

Insulinoma : presentación de un caso clínico

En este artículo presentamos un caso clínico de tumor funcional de células ß o insulinoma, así como los puntos más relevantes para su diagnóstico y tratamiento.In this paper, a clinical case of ß-cell functional tumor, or insulinoma, is presented, as well as the main points relevant to its diagnosis and treatment

Gamma-Secretase-Dependent and -Independent Effects of Presenilin1 on β-Catenin·Tcf-4 Transcriptional Activity

Presenilin1 (PS1) is a component of the γ-secretase complex mutated in cases of Familial Alzheimer's disease (FAD). PS1 is synthesized as a 50 kDa peptide subsequently processed to two 29 and 20 kDa subunits that remain associated. Processing of PS1 is inhibited by several mutations detected in FAD patients. PS1 acts as negative modulator of β-catenin·Tcf-4 transcriptional activity. In this article we show that in murine embryonic fibroblasts (MEFs) the mechanisms of action of the processed and non-processed forms of PS1 on β-catenin·Tcf-4 transcription are different. Whereas non-processed PS1 inhibits β-catenin·Tcf-4 activity through a mechanism independent of γ-secretase and associated with the interaction of this protein with plakoglobin and Tcf-4, the effect of processed PS1 is prevented by γ-secretase inhibitors, and requires its interaction with E- or N-cadherin and the generation of cytosolic terminal fragments of these two cadherins, which in turn destabilize the β-catenin transcriptional cofactor CBP. Accordingly, the two forms of PS1 interact differently with E-cadherin or β-catenin and plakoglobin: whereas processed PS1 binds E-cadherin with high affinity and β-catenin or plakoglobin weakly, the non-processed form behaves inversely. Moreover, contrarily to processed PS1, that decreases the levels of c-fos RNA, non-processed PS1 inhibits the expression c-myc, a known target of β-catenin·Tcf-4, and does not block the activity of other transcriptional factors requiring CBP. These results indicate that prevention of PS1 processing in FAD affects the mechanism of repression of the transcriptional activity dependent on β-catenin

The Role of Presenilin and its Interacting Proteins in the Biogenesis of Alzheimer’s Beta Amyloid

The biogenesis and accumulation of the beta amyloid protein (Aβ) is a key event in the cascade of oxidative and inflammatory processes that characterises Alzheimer’s disease. The presenilins and its interacting proteins play a pivotal role in the generation of Aβ from the amyloid precursor protein (APP). In particular, three proteins (nicastrin, aph-1 and pen-2) interact with presenilins to form a large multi-subunit enzymatic complex (γ-secretase) that cleaves APP to generate Aβ. Reconstitution studies in yeast and insect cells have provided strong evidence that these four proteins are the major components of the γ-secretase enzyme. Current research is directed at elucidating the roles that each of these protein play in the function of this enzyme. In addition, a number of presenilin interacting proteins that are not components of γ-secretase play important roles in modulating Aβ production. This review will discuss the components of the γ-secretase complex and the role of presenilin interacting proteins on γ-secretase activity