Biomedical subjects

J Zorrilla

Publications and source records attributed to J Zorrilla.

3 recordsLinked to original sources

PubMed2001

[Lumbar root compression secondary to juxtafacet cysts: review of 10 cases].

OBJECT: We report a series of 10 patients with 11 juxtafacet cysts of the lumbar spine treated in our center from 1994 to 2000. METHODS: The clinical histories, radiographic images, surgical protocols and pathological records of the 10 patients diagnosed of lumbar juxtafacet cyst have been analyzed. RESULTS: Six patients were women and four were men. The average age of presentation was 54 years. The most frequent clinical presentation was radicular pain, and motor or sensitive deficits were not very common. Computed tomography and magnetic resonance are essential in establishing the diagnosis. The cysts were located at L4-L5 in eight patients, at L2-L3 in one patient, and at L3-L4 in other patient. Eight patients were treated by means of decompressive laminectomy and excision of the cyst, and the remaining two underwent conservative treatment. Degenerative phenomena adjacent to the juxtafacet cysts are easy to evidence. All the patients were improved of their radicular pain. CONCLUSIONS: Analysing our series, we conclude that the juxtafacet cysts appear more frequently at L4-L5 level in people of advanced age, and produce commonly low back pain and radiculopathy. Although they can be treated initially in a conservative way, in the presence of a progressive sciatic syndrome, surgical management is preferable.

Adult↗

PubMed1997

Formation of olfactory memories mediated by nitric oxide.

Sheep learn to recognize the odours of their lambs within two hours of giving birth, and this learning involves synaptic changes within the olfactory bulb. Specifically, mitral cells become increasingly responsive to the learned odour, which stimulates release of both glutamate and GABA (gamma-aminobutyric acid) neurotransmitters from the reciprocal synapses between the excitatory mitral cells and inhibitory granule cells. Nitric oxide (NO) has been implicated in synaptic plasticity in other regions of the brain as a result of its modulation of cyclic GMP levels. Here we investigate the possible role of NO in olfactory learning. We find that the neuronal enzyme nitric oxide synthase (nNOS) is expressed in both mitral and granule cells, whereas the guanylyl cyclase subunits that are required for NO stimulation of cGMP formation are expressed only in mitral cells. Immediately after birth, glutamate levels rise, inducing formation of NO and cGMP, which potentiate glutamate release at the mitral-to-granule cell synapses. Inhibition of nNOS or guanylyl cyclase activity prevents both the potentiation of glutamate release and formation of the olfactory memory. The effects of nNOS inhibition can be reversed by infusion of NO into the olfactory bulb. Once memory has formed, however, inhibition of nNOS or guanylyl cyclase activity cannot impair either its recall or the neurochemical release evoked by the learned lamb odour. Nitric oxide therefore seems to act as a retrograde and/or intracellular messenger, being released from both mitral and granule cells to potentiate glutamate release from mitral cells by modulating cGMP concentrations. We propose that the resulting changes in the functional circuitry of the olfactory bulb underlie the formation of olfactory memories.

Animals↗

PubMed1993

[Pituitary abscess].

A pituitary abscess case clinically evolving as an adenoma is presented. The diagnosis was established at the time the surgical procedure was performed. Previous studies and postoperative investigation proved the absence of features accounting for side infection. Moreover, anatomopathological studies also dismissed the existence of any type of tumoral traces. However, due to a lack of experience, the pre-operative magnetic resonance imaging was interpreted as pertaining to pituitary adenoma on the basis of its greater frequency.

Abscess↗