Biomedical subjects

A M Llorente

Publications and source records attributed to A M Llorente.

7 recordsLinked to original sources

PubMed2001

Long-term effects of high-dose zidovudine treatment on neuropsychological performance in mildly symptomatic HIV-positive patients: results of a randomized, double-blind, placebo-controlled investigation.

This study examined the treatment outcome of high-dose (1500 mg/day) zidovudine (AZT) on neuropsychological (NP) functioning (Trailmaking Test A & B, WAIS-R Digit Symbol, and Rey Auditory Verbal Learning Test) across a 12-month period in mildly symptomatic HIV-1 seropositive men (n = 46 at entry) enrolled in a randomized, double-blind, placebo-controlled trial (VA Cooperative Studies Program #298). Neither short-term (0-6 months) nor long-term (0-12 months) AZT administration revealed enhancement in NP performance. The results suggest that, although AZT may afford patients prophylactic benefits, protracted high-dose AZT treatment does not improve NP functioning in mildly symptomatic HIV-positive individuals.

Adult↗

PubMed2001

Early predictors of neurodevelopmental outcome in symptomatic congenital cytomegalovirus infection.

OBJECTIVE: To determine the ability of neonatal clinical, audiologic, and computed tomography (CT) findings to predict long-term neurodevelopmental outcome in children with symptomatic congenital cytomegalovirus (CMV) infection. METHODS: Longitudinal cohort study of children (n = 41) with symptomatic congenital CMV infection evaluated at birth and followed up with serial age-appropriate neurodevelopmental testing. The performance of birth characteristics as predictors of long-term outcome were determined, and clinical and CT scoring systems were developed and correlated with intellectual outcome. RESULTS: Microcephaly was the most specific predictor of mental retardation (100%; 95% CI 84.5-100) and major motor disability (92.3%; 95% CI 74.8-99). An abnormality detected by CT was the most sensitive predictor for mental retardation (100%; 95% CI 82.3-100) and motor disability (100%; 95% CI 78.2-100). A highly significant (P <.001) positive correlation was found between head size at birth and the intelligence/developmental quotient (IQ/DQ). Approximately 29% of children had an IQ/DQ >90. There was no association between sensorineural hearing loss at birth and cognitive outcome. However, children with sensorineural hearing loss on follow-up (congenital and late-onset) had a lower IQ/DQ (P =.006) than those with normal hearing. CONCLUSIONS: The presence of microcephaly at birth was the most specific predictor of poor cognitive outcome in children with symptomatic congenital CMV infection, whereas children with normal findings on head CT and head circumference proportional to weight exhibited a good cognitive outcome.

Cerebral Palsy↗

PubMed2001

A randomized, double-blind, placebo-controlled trial of docosahexaenoic acid supplementation in children with attention-deficit/hyperactivity disorder.

OBJECTIVE: To determine whether docosahexaenoic acid (DHA) supplementation for 4 months decreases the symptoms of attention-deficit/hyperactivity disorder (ADHD). STUDY DESIGN: Sixty-three 6- to-12-year-old children with ADHD, all receiving effective maintenance therapy with stimulant medication, were assigned randomly, in a double-blind fashion, to receive DHA supplementation (345 mg/d) or placebo for 4 months. Outcome variables included plasma phospholipid fatty acid patterns, scores on laboratory measures of inattention and impulsivity (Test of Variables of Attention, Children's Color Trails test) while not taking stimulant medication, and scores on parental behavioral rating scales (Child Behavior Checklist, Conners' Rating Scale). Differences between groups after 4 months of DHA supplementation or placebo administration were determined by analysis of variance, controlling for age, baseline value of each outcome variable, ethnicity, and ADHD subtype. RESULTS: Plasma phospholipid DHA content of the DHA-supplemented group was 2.6-fold higher at the end of the study than that of the placebo group (4.85 +/- 1.35 vs 1.86 +/- 0.87 mol % of total fatty acids; P <.001). Despite this, there was no statistically significant improvement in any objective or subjective measure of ADHD symptoms. CONCLUSION: A 4-month period of DHA supplementation (345 mg/d) does not decrease symptoms of ADHD.

Analysis of Variance↗

PubMed2000

Effects of test administration order on children's neuropsychological performance: emerging one-word expressive and receptive language skills.

Differences in neuropsychological performance associated with specific test presentation sequences have been reported in adults. However, these effects have received little attention in children. The EOWPVT-R, a measure of one-word expressive language, and the PPVT-R, a measure of receptive language, were administered to 6- to 14-year-olds (control [n = 17] and experimental [n = 22] groups) in a counterbalanced fashion to investigate the potential effects of test presentation sequence on neuropsychological performance. Group findings were not evidenced subsequent to variation in test administration sequence. In contrast, order of test presentation revealed differences in performance. Administration of the PPVT-R prior to the EOWPVT-R resulted in enhanced EOWPVT-R expressive language scores in both groups of participants. Presentation of the PPVT-R after the EOWPVT-R did not affect performance. Applied and theoretical implications associated with these findings are discussed.

Adolescent↗

PubMed1999

Stimulant medications decrease energy expenditure and physical activity in children with attention-deficit/hyperactivity disorder.

OBJECTIVE: To determine the effect of stimulant medications used to treat children with attention-deficit/hyperactivity disorder (AD/HD) on energy expenditure, fuel utilization, and physical activity. STUDY DESIGN: Energy expenditure and physical activity were measured, respectively, by room respiration calorimetry and microwave motion detectors in 31 children with AD/HD (26 boys and 5 girls; ages 6 to 12 years) both while they were receiving their prescribed stimulant medication and after the medication had been discontinued for at least 24 hours. Fuel utilization was calculated from calorimetry data. RESULTS: Total and awake energy expenditure including energy expended while doing schoolwork, riding a stationary bicycle, resting, and watching a movie were from 4% to 8% lower when the children were receiving their prescribed stimulant medication. Total and awake activity were also lower while they were receiving medication (16% to 22%) and accounted for the lower rates of energy expenditure. Sleeping metabolic rate, basal metabolic rate, and fuel utilization were unaffected by medication. CONCLUSIONS: Stimulant medications decrease physical activity, and hence, decrease the activity component of total daily energy expenditure in children with AD/HD.

Analysis of Variance↗

PubMed1998

Slowed information processing in HIV-1 disease. The Multicenter AIDS Cohort Study (MACS).

This investigation examined the effects of HIV-1 infection on speeded complex cognitive processing in a group of HIV-negative (n = 666), HIV-positive symptomatic (n = 156), and HIV-positive asymptomatic (n = 623) participants while controlling for the effects of slowed motor functioning, peripheral neuropathy, and several other putative confounds. Stroop Interference and reaction-time tasks served as anchor procedures to assess cognitive processing. The present findings suggest that HIV-1 infection is capable of compromising CNS-mediated cognitive processes (speeded processing) infringing upon their efficacy in the symptomatic stages of the disease while sparing individuals in the asymptomatic stage. The detrimental effects observed on information-processing mechanisms associated with HIV infection persisted despite the use of procedures to control for peripheral nerve integrity and other potential confounds.

AIDS Dementia Complex↗

PubMed1993

Behavior analysis of motion control for pediatric neuroimaging.

Magnetic resonance imaging is a promising technological advance used for research and diagnosis of disease. The procedure has no risks, except when uncooperative patients require sedation. Four normal children participated in simulated scans to study the effects of (a) antecedent changes in the imaging environment and (b) operant conditioning of movement inhibition. Changing the environment can decrease movement, but operant contingencies were necessary to decrease movement to a level that, in most cases, would allow the procedure to occur without sedation.

Behavior Therapy↗