Biomedical subjects

P De Riu

Publications and source records attributed to P De Riu.

3 recordsLinked to original sources

PubMed2003

Tyrosinated alpha-tubulin changes following epileptogenic and non-epileptogenic lesions in rat brain cortex.

The expression of the tyrosinated isoform of alpha-tubulin was monitored in rat frontal cortex, in order to investigate the neuronal plasticity changes occurring either in a mirror focus or in a deafferented area. A mirror focus was triggered by epidural implantation of a cobalt gelatin disk in the contralateral left somatosensory area (group one). A deafferented area was obtained by surgical removal of the left frontal cortex (group two). All animals including controls underwent EcoG recordings immediately before killing (45, 60, 90 days post surgery). The right frontal cortex was removed from all the animals and processed with Western blot method. EcoG recordings revealed a paroxysmal activity in epileptic rats, whereas in rats with frontal deafferentation and controls, EcoG activity was normal. A significant increase in tyrosinated alpha-tubulin expression was detected both in the mirror focus (group one) and the "non-epileptic" deafferented frontal cortex (group two) in comparison with controls (group three). The transcallosal deafferentation, which is involved in both epileptogenic and non-epileptogenic lesions, is supposed to play a role in the mechanism responsible for the plasticity responses recorded in the cortical areas studied.

Action Potentials↗

PubMed1991

Brain interstitial fluid collected through implanted tissue cages.

The physicochemical properties of the whole-brain interstitial fluid (IF) are unknown. A volume of whole-brain IF sufficient for analysis was obtained through a small, hollow, multiperforated polypropylene sphere implanted for 4-5 weeks into the dog brain parenchyma. The main physicochemical properties of the whole-brain IF were characterized, in comparison with the physicochemical properties of cerebrospinal fluid and blood/serum.

Amino Acids↗

PubMedDate not supplied

Brain interstitial fluid and intracellular distribution of phenytoin.

After intravenous (i.v.) administration (10 mg/kg), the biodisposition of phenytoin (PHT) in serum (total and free concentration), cerebrospinal fluid (CSF), brain, and the interstitial fluid (IF) of the normal brain were determined in dogs. A sufficient volume of IF was obtained through a multiperforated polypropylene ball implanted into the left parietotemporal region for 4-5 weeks. PHT brain distribution coefficient values ranged between 1.9 and 3.75, while the ratios of IF to free serum PHT concentrations ranged between 0.19 and 1.04; thus, our data indicate that most of the free unbound PHT which enters the brain parenchyma accumulates in the cellular compartment. Furthermore, at 60 and 90 min the peak CSF and IF concentrations are delayed; thus, for PHT, an apparent diffusion front from the CSF into the extracellular space of the brain seems to occur.

Animals↗