Biomedical subjects

C C Castro

Publications and source records attributed to C C Castro.

5 recordsLinked to original sources

PubMed2002

Relation between medial temporal atrophy and functional brain activity during memory processing in Alzheimer's disease: a combined MRI and SPECT study.

OBJECTIVE: To investigate the relation between atrophy of the hippocampal region and brain functional patterns during episodic memory processing in Alzheimer's disease. PATIENTS AND METHODS: Whole brain structural magnetic resonance imaging (MRI) data and single photon emission computed tomography (SPECT) measures of regional cerebral blood flow (rCBF) were obtained during a verbal recognition memory task in nine subjects with mild Alzheimer's disease and 10 elderly healthy controls. Using the statistical parametric mapping approach, voxel based comparisons were made on the MRI data to identify clusters of significantly reduced grey matter concentrations in the hippocampal region in the Alzheimer patients relative to the controls. The mean grey matter density in the voxel cluster of greatest hippocampal atrophy was extracted for each Alzheimer subject. This measure was used to investigate, on a voxel by voxel basis, the presence of significant correlations between the degree of hippocampal atrophy and the rCBF SPECT measures obtained during the memory task. RESULTS: Direct correlations were detected between the hippocampal grey matter density and rCBF values in voxel clusters located bilaterally in the temporal neocortex, in the left medial temporal region, and in the left posterior cingulate cortex during the memory task in the Alzheimer's disease group (p < 0.001). Conversely, measures of hippocampal atrophy were negatively correlated with rCBF values in voxel clusters located in the frontal lobes, involving the right and left inferior frontal gyri and the insula (p < 0.001). CONCLUSIONS: Hippocampal atrophic changes in Alzheimer's disease are associated with reduced functional activity in limbic and associative temporal regions during episodic memory processing, but with increased activity in frontal areas, possibly on a compensatory basis.

Alzheimer Disease↗

PubMed2001

Regional cerebral blood flow abnormalities in early-onset obsessive-compulsive disorder: an exploratory SPECT study.

OBJECTIVE: Recent epidemiological and clinical data suggest that obsessive-compulsive disorder (OCD) may be subtyped according the age of onset of obsessive-compulsive symptoms. The regional cerebral blood flow (rCBF) single photon emission computed tomography (SPECT) technique was used to investigate whether the pathophysiology of OCD differs between early- and late-onset OCD subjects. METHOD: Resting rCBF was measured in 13 early-onset (<10 years) and 13 late-onset (>12 years) adult OCD subjects and in 22 healthy controls. Voxel-based rCBF comparisons were performed with statistical parametric mapping. RESULTS: Early-onset OCD cases showed decreased rCBF in the right thalamus, left anterior cingulate cortex, and bilateral inferior prefrontal cortex relative to late-onset subjects (p < .0005, uncorrected for multiple comparisons). Relative to controls, early-onset cases had decreased left anterior cingulate and right orbitofrontal rCBF, and increased rCBF in the right cerebellum, whereas late-onset subjects showed reduced right orbitofrontal rCBF and increased rCBF in the left precuneus. In early-onset subjects only, severity of obsessive-compulsive symptoms correlated positively with left orbitofrontal rCBF. CONCLUSIONS: rCBF differences in frontal-subcortical circuits between early-onset and late-onset OCD subjects were found, both in location and direction of changes. These results provide preliminary evidence that brain mechanisms in OCD may differ depending on the age at which symptoms are first expressed.

Adolescent↗

PubMed1999

The importance of specific IgG and IgE autoantibodies to retinal S antigen, total serum IgE, and sCD23 levels in autoimmune and infectious uveitis.

Autoimmunity plays an important role in the development of uveitis. The uveitis are linked to Th1 or Th2 lymphocyte activation. We studied 41 patients with uveitis, divided into autoimmune uveitis (n = 32) and infectious uveitis (n = 9), 30 normal controls, and 20 asthmatic atopic without ocular diseases. The infectious uveitis patients were separated into bacterial (n = 6) and toxoplasmic (n = 3) retinochoroiditis. We measured IgE and sCD23 serum levels and specific IgG and IgE to retinal S antigen by ELISA tests. The IgE levels were 500 +/- 325 kU/L in autoimmune uveitis, 57 +/- 35 kU/L in bacterial uveitis, 280 +/- 38 kU/L in toxoplasmic retinochoroiditis, 75 +/- 32 kU/L in the controls, and 557 +/- 243 kU/L in atopics (P < 0.0005). The sCD23 levels were 10.4 +/- 5.4 ng/ml in autoimmune uveitis, 3.7 +/- 1.17 ng/ml in bacterial uveitis, 6.76 +/- 1.36 ng/ml in toxoplasmic retinochoroiditis, 3.4 +/- 1 ng/ml in controls, and 8.35 +/- 2.2 ng/ml in atopic patients (P < 0.005). The specific IgG to retinal S antigen was positive in 27 of 32 cases, and the specific IgE to retinal S antigen was positive in 22 of 32 autoimmune uveitis. The bacterial uveitis patients as well as the controls were negative for both autoantibodies to retinal S antigen. The toxoplasmic retinochoroiditis patients presented specific IgG and IgE to retinal S antigen in two of three cases, respectively, one of them with overlap of both antibodies. These results suggest the importance of specific IgG and IgE to retinal S antigen in autoimmune uveitis, which, along with higher IgE and sCD23 levels, reveal Th2 activation.

Adult↗

PubMed1999

[Importance of the benzylpenicillin nucleus and the side chain of the beta-lactams. Demonstration by skin tests and RAST in penicillin allergic patients].

We studied 30 patients with beta-Lactams allergy demonstrated by clinical findings. The aim of this work was to determine the capacity of the beta-Lactams nucleus and the side chain in the induction of specific IgE to BPO, Ax, Amp, performed by intradermal skin test and RAST. The patients were divided by clinical manifestations in: 1-Accelerated reactions (n:19); and 2-Immediate reactions (n:11). The Prick tests were performed with BPO-PL, Ax-PL, Amp-PL, MDM-BP, MDM-Ax, MDM-Amp. The accelerated group presented BPO-PL (+) in 2 cases, Ax-PL & Amp-PL (+) in 4 cases, and all of the reactives were (+) in 13 out of 19 cases. The immediate group presented MDM-BP (+) in 10 out of 11 cases and MDM-Amp was (+) in 1 out of 11 cases. The RAST's were performed in all patients(n:30). In accelerated group were (+) to BPO-PL in 13 out of 19 cases, to Ax-PL in 3 out of 19 cases, to Amp-PL in 1 out 19 cases, to BPO-PL and Ax-PL on overlap in 1 out of 19 cases, and 1 case was negative to all reactives. The immediate group presented RAST's negatives in 11 out of 11 cases. The control group(n:20) presented Prick (+) to Ax-PL in 1 out of 20 cases, and the others reactives were negatives in all cases. The RAST's to all reactives were (-) in 20 out of 20 subjects. These results indicate that BPO was the most important determinant, and the side chain of the Ax or Amp were others determinants of the beta-Lactams drugs. These determinants induced specific IgE, and in rare occasions appears specific IgE for two different determinants on overlap in the same patient. The intradermal skin testing is the method of choice to study the penicillin allergies, because non satisfactory RAST's have yet been developed for minor determinant-specific IgE antibodies.

Adult↗

PubMedDate not supplied

Correlation between osteochondral changes depicted by magnetic resonance imaging and disease progression.

PURPOSE: To determine the consequences of the chronic use of systemic corticosteroids in children with juvenile rheumatoid arthritis by means of evaluating osteochondral effects depicted by magnetic resonance imaging. PATIENTS AND METHODS: We reviewed clinical and magnetic resonance imaging findings in 69 children (72 knees) with juvenile rheumatoid arthritis. Two groups were studied. Group I: 34 (49.3%) children had previous or current use of systemic corticotherapy (22 girls; 12 boys; mean age: 11.3 years; mean disease duration: 5.9 years; mean corticotherapy duration: 2.9 years; mean cumulative dose of previous corticosteroids: 5000 mg); Group II: 35 (50.7%) children had no previous use of corticosteroids (27 girls; 8 boys; mean age: 11.7 years; mean disease duration: 5.3 years). The groups were compared statistically. RESULTS: In the group that had received corticotherapy (Group I), osteochondral abnormalities were significantly correlated to long-standing disease (>3.5 years; p<0.001). This correlation was not found in the group that had no previous history of corticotherapy (Group II). No correlations were established between median dose of corticosteroids and magnetic resonance imaging findings. CONCLUSION: It is important to further investigate the long-term intra-articular effects of systemic corticotherapy to ensure that the side effects of the aggressive therapy will not be more harmful for the joints than the symptoms suffered over the natural course of the disease.

Adolescent↗