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Biomedical subjects

R Blesa

Publications and source records attributed to R Blesa.

At least 55 records · Page 3Linked to original sources
PubMed1989

[AIDS dementia complex as the 1st manifestation of the acquired immunodeficiency syndrome].

In a prospective follow-up period from September 1987 to August 1988, the AIDS dementia complex (ADC) was the presenting clinical feature in six of 102 patients in whom AIDS was diagnosed in the Hospital Clínic i Provincial from Barcelona. The clinical picture was characterized by subcortical type deterioration and motor disturbances. Cerebrospinal fluid investigation and imaging techniques excluded other types of neurological involvement, and the diagnosis was confirmed at autopsy in two patients. The present study suggested that: 1) the ADC may be the presenting feature of AIDS in patients with unknown seropositive status; 2) in our area, ADC represents one of the most common causes of dementia in young patients, and 3) although a specific marker permitting a definitive clinical diagnosis is not available, at the time of diagnosis all patients had a severe degree of cellular immunosuppression induced by type 1 human immunodeficiency virus.

AIDS Dementia Complex↗
PubMed1989

Acute effects of 1-methyl-1,4-phenylpyridinium ion (MPP+) on purine metabolism in rat striatum studied in vivo using the microdialysis technique.

In order to obtain further insight into the interactions between the purinergic and dopaminergic pathways in the striatum, we studied both metabolisms simultaneously, using a microdialysis technique in 1-methyl-1,4-phenylpyridinium ion (MPP+) unilaterally-denervated conscious rats. In these rats the contralateral side was used as control. The perfusates were collected every 20-25 min using 4 mm dialysis probes, implanted in each striatum, and assayed for dopamine and purine metabolites. After MPP+ administration, all adenosine metabolites - with the exception of uric acid - and dopamine levels were significantly increased in the extracellular medium. However, the time-course change in dopamine level did not correlate with the adenosine and inosine time-courses, suggesting a different mechanism of liberation in response to MPP+ administration.

1-Methyl-4-phenylpyridinium↗
PubMed1989

Dopamine D1 and D2 receptors visualized in MPTP treated C57 mice by in vitro autoradiography: lack of evidence of receptor modifications in parkinsonian mice.

The effect of the neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) on D1 and D2 dopamine receptors was assayed using in vitro quantitative autoradiography. D1 receptor subtype was labeled using 1 nM of 3H-SCH 23390 and D2 receptor subtype was labeled using 0.4 nM of 3H-spiroperidol. The results are compared to the effect of MPTP on the striatal levels of dopamine and its metabolites, in BL C57 mice. While 2 and 5 doses of MPTP 30 mg/kg/day intraperitoneally reduced the content of striatal dopamine and its metabolites, no modifications were detected in D2 receptor subtype in any cerebral area studied. However, D1 receptors were reduced in the substantia nigra 24 hr after the last of 2 doses, but not later. We suggest a compensatory mechanism of the surviving dopaminergic neurones as well as the participation of spare receptors. This would explain the lack of receptor modification after the lesion obtained as seen by the striatal reduction of dopamine and metabolites content, after MPTP administration.

3,4-Dihydroxyphenylacetic Acid↗
PubMed1989

[Hemangioma of the vertebrae: contribution of magnetic resonance to its study].

Vertebral hemangioma is a benign vascular tumor predominantly involving the dorsolumbar spine. Although most of these tumors are asymptomatic, they may result in radiculopathy and/or compressive myelopathy. Plain X-ray films and computed tomography (CT) generally permit the diagnosis by showing characteristic images with hypertrophic bone trabeculation in the vertebral body. We report three patients with vertebral hemangioma in which CT was diagnostic. Magnetic resonance (MR) with low intensity field was inferior to CT for the suggestion of the diagnosis of hemangioma, but had a better definition for subarachnoid space obliteration and spinal cord compression.

Adult↗
PubMed1988

Acute effects of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) on catecholamines in heart, adrenal gland, retina and caudate nucleus of the cat.

The short-term (24 h) effects of 10 mg/kg of the neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) on cat catecholamine levels of heart, adrenal gland, retina, and caudate nucleus were studied. Significant differences in catecholamines, including adrenomedullar adrenaline, heart noradrenaline, and retinal dopamine, were observed. No differences were found in caudate nucleus dopamine. In this organ, the levels of dopamine metabolites, 3,4-dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA) were significantly lower after MPTP treatment. Biochemical changes caused by MPTP with respect to its effects on the peripheral catecholaminergic organs are discussed.

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine↗
PubMed1988

Chronic intestinal pseudoobstruction and ophthalmoplegia in a patient with mitochondrial myopathy.

A 38 year old woman having chronic intestinal pseudoobstruction associated with mitochondrial myopathy is reported. The clinical and radiographic features suggested the diagnosis of chronic intestinal pseudoobstruction. Muscular atrophy and ophthalmoplegia led to muscle biopsy, which disclosed accumulation of normal and abnormal mitochondria ('ragged red fibres'), characteristic of mitochondrial myopathy.

Adult↗
PubMed1987

Low-dose bromocriptine in the early phases of Parkinson's disease.

The effect of bromocriptine at doses up to 20 mg/day was studied in a single-blind format with a placebo phase in 15 Parkinson's disease patients with mild-to-moderate disability who had not been previously treated with levodopa. For the 11 patients who completed the 9 month trial, both Northwestern University Disability Scale and Columbia University Rating Scale scores were significantly reduced during bromocriptine therapy, when compared with either baseline or placebo scores. Two patients improved greater than 50% and had no side effects. Transient side effects appeared in four patients. Bromocriptine at doses of 20 mg/day or below may yield effective symptomatic improvement in de novo parkinsonism and may be considered as the initial treatment in young parkinsonian patients with only mild-to-moderate disability.

Adult↗
PubMedDate not supplied

Cerebral metabolic changes in Alzheimer's disease: neurobehavioral patterns.

Regional cerebral glucose metabolism was surveyed in 37 Alzheimer's disease (AD) patients and 21 normal controls using positron emission tomography. Where possible, brain regions were specified according to their neurobehavioral function rather than as anatomically demarcated structures. Absolute metabolic values revealed significant differences (p < 0.05) between AD patients and controls for whole brain and the more superior supratentorial brain slices. Normalized values (region/brain stem) showed the most striking declines (p < 0.001) in the association cortex (heteromodal region -21%; unimodal region -19%) and the primary sensory-motor cortex (-13%), with motor, auditory, and visual areas more affected than somatosensory areas. Limbic and paralimbic systems were equally affected (-14%; -11%; p < 0.001). Thalamus, striatum, cerebellum and brain stem were minimally or not affected. Neurobehaviorally defined hypometabolic regions largely parallel affected areas noted in anatomic and previous metabolic studies, with the possible exception of metabolic deficits in the primary sensory-motor complex. Conceivably, brain areas unaffected morphologically by the pathophysiological processes of AD may become dysfunctional due to a disruption of connectivity between regions.

Adult↗