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Biomedical subjects

A Aleman

Publications and source records attributed to A Aleman.

At least 19 recordsLinked to original sources
PubMed2001

Handedness, language lateralisation and anatomical asymmetry in schizophrenia: meta-analysis.

BACKGROUND: Cerebral lateralisation appears to be decreased in schizophrenia. Results of studies investigating this, however, are equivocal. AIMS: To review quantitatively the literature on decreased lateralisation in schizophrenia. METHOD: Meta-analyses were conducted on 19 studies on handedness, 10 dichotic listening studies and 39 studies investigating anatomical asymmetry in schizophrenia. RESULTS: The prevalence of mixed- and left-handedness ('non-right-handedness') was significantly higher in patients with schizophrenia as compared to healthy controls, and also as compared to psychiatric controls. The analysis of dichotic listening studies revealed no significant difference in lateralisation in schizophrenia. However, when analysis was restricted to studies using consonant-vowel or fused word tasks, significantly decreased lateralisation in schizophrenia emerged. Asymmetry of the planum temporale and the Sylvian fissure was significantly decreased in schizophrenia, while asymmetry of the temporal horn of the lateral ventricle was not. CONCLUSION: Strong evidence is provided for decreased cerebral lateralisation in schizophrenia.

Brain↗
PubMed2000

Music training and mental imagery ability.

Neuroimaging studies have suggested that the auditory cortex is involved in music processing as well as in auditory imagery. We hypothesized that music training may be associated with improved auditory imagery ability. In this study, performance of musically trained and musically naive subjects was compared on: (1) a musical mental imagery task (in which subjects had to mentally compare pitches of notes corresponding to lyrics taken from familiar songs); (2) a non-musical auditory imagery task (in which subjects had to mentally compare the acoustic characteristics of everyday sounds); and (3) a comparable measure of visual imagery (in which subjects had to mentally compare visual forms of objects). The musically trained group did not only perform better on the musical imagery task, but also outperformed musically naive subjects on the non-musical auditory imagery task. In contrast, the two groups did not differ on the visual imagery task. This finding is discussed in relation to theoretical proposals about music processing and brain activity.

Adult↗
PubMed2000

Growth hormone, insulin-like growth factor I and cognitive function in adults.

This review focuses on the possible contribution of the growth hormone (GH)-insulin-like growth factor I (IGF-I) axis to cognitive function. Binding sites for GH and IGF-I are found in various areas of the brain. Their distribution suggests that GH and IGF-I contribute to the function of the hippocampus, a brain structure important for the maintenance of cognitive functions such as learning and memory. Evidence for cognitive deficits in GH-deficient individuals has been found in various studies, some of which have shown that these deficits can be reversed by GH substitution therapy. In addition to examining conditions of GH deficiency, this article reviews studies evaluating the correlation between the cognitive deficits associated with ageing and age-related decreases in GH or IGF-I secretion. Based on the available data, one might hypothesize that relative GH or IGF-I deficiency could contribute to the deterioration of cognitive functions observed in the elderly.

Adult↗
PubMed2000

Cognitive functioning after whiplash injury: a meta-analysis.

Complaints on cognitive functioning are often reported in patients suffering from whiplash syndrome, although objective neuropsychological test results do not always support these. In addition, radiological abnormalities and anatomical lesions are found only in a minority of these patients. This has led to a controversy about its existence in the literature. In this systematic review, the results of 22 neuropsychological studies on whiplash were quantitatively analyzed, focusing on working memory, attention, immediate and delayed recall, visuomotor tracking, and cognitive flexibility. Our findings suggest that a consistent overall pattern of cognitive dysfunction can be demonstrated after whiplash injury through neuropsychological testing, both compared to healthy and to asymptomatic controls. Six months after the accident, improvement is found in working memory, attention, immediate recall, and visuomotor tracking. The results are discussed in the light of recent findings on the effect of cerebral dysfunction, malingering, pain-related factors, and the role of coping strategies and posttraumatic stress on neuropsychological test performance.

Brain Injury, Chronic↗
PubMed2000

High-dose ifosfamide and etoposide with filgrastim for stem cell mobilization in patients with advanced ovarian cancer.

High-dose chemotherapy combined with autologous peripheral blood stem cell transplantation has shown promise as treatment for recurrent or persistent epithelial ovarian cancer. We evaluated the stem cell mobilization regimen of high-dose ifosfamide plus etoposide in 32 patients with epithelial ovarian cancer, who had a positive second-look laparatomy or recurrent disease. Ifosfamide was given at 10 g/m2 by continuous i.v. from days 1 to 3. Etoposide was given at 150 mg/m2 every 12 h for six doses on days 1-3. Filgrastim was given at 10 microg/kg/d s.c. from day 5 until the completion of peripheral blood stem cell harvest. Fourteen of 32 patients had measurable or evaluable disease before mobilization therapy and were assessed for response. In nine (64%) of the 14 patients, treatment response was demonstrated, and these patients received a second cycle of mobilization therapy. The target CD34+ cell dose (>8 x 106 cells/kg) was achieved with a median of one apheresis (range 1-5). A median of 25.1 (range 8.0-122.5) x 106 CD34+ cells/kg body weight was collected. Non-hematologic toxicity was limited to grade 2 renal dysfunction in one patient and grade 2 hepatic dysfunction in three patients. In this patient group, high-dose ifosfamide plus etoposide with filgrastim support was well tolerated, lead to successful stem cell harvest and had antitumor activity.

Adult↗
PubMed2000

Mental imagery and perception in hallucination-prone individuals.

College students screened for hallucination-proneness using the Launay-Slade Hallucination Scale (LSHS) were compared on measures of self-report vividness of imagery and on behavioral measures of imagery and perception (visual and auditory). Specifically, we tested the hypothesis whether hallucination-prone individuals would show smaller differences between imagery and perception performance, which may be indicative of increased sensory characteristics of mental images. We replicated earlier findings of higher self-report imagery ratings in the high hallucination-prone group. However, the two groups did not differ on five of six behavioral imagery-perception comparisons. On one visual task, hallucination-proneness was associated with larger imagery-perception differences. Our results reveal a dissociation between the level of subjective experience and the information processing level. Although vividness of mental images may be subjectively associated with mild hallucinatory experiences, we suggest that cognitive processes associated with reality discrimination rather than increased perceptual characteristics of mental images may play a role at the information processing level.

Adult↗
PubMed2000

Age-sensitive cognitive function, growth hormone and insulin-like growth factor 1 plasma levels in healthy older men.

Circulating levels of growth hormone (GH) change during the process of aging. Decline of cognitive functioning with aging is also well established. In this study, we investigated whether insulin-like growth factor 1 (IGF-1) and the GH response to a challenge of GH-releasing hormone and GH-releasing peptide 6 were associated with age-sensitive cognitive functions, but not with functions that do not decline with aging, in 17 healthy male subjects aged between 66 and 76 years. In addition, relations with anthropometric measures were examined. Neuropsychological performance was scored on tests of variables not sensitive to aging (general knowledge, vocabulary, basic visual perception and reading ability), and of variables sensitive to aging (visuoconstructive ability, perceptual motor and mental processing speed, and verbal long-term memory). After correcting for education, the serum GH response was significantly associated with two age-sensitive cognitive tests (measures of mental processing speed), but with none of the tests not sensitive to aging. However, the direction of the association was opposite to the relation between IGF-1 and these cognitive tests: higher levels of GH response were associated with poorer cognitive performance, whereas higher levels of IGF-1 were associated with better performance. GH response, but not IGF-1, was inversely correlated with body mass index. The results are in accordance with previous research suggesting a disruption of the relation between IGF-1 and GH secretion in older age.

Aged↗
PubMed1999

Memory impairment in schizophrenia: a meta-analysis.

OBJECTIVE: Memory impairment is well documented in schizophrenia. Less is known, however, about the exact magnitude, pattern, and extent of the impairment. The effect of potential moderator variables, such as medication status and duration of illness, is also unclear. In this article, the authors presented meta-analyses of the published literature on recall and recognition memory performance between patients with schizophrenia and normal comparison subjects. METHOD: Meta-analyses were conducted on 70 studies that reported measures of long-term memory (free recall, cued recall, and recognition of verbal and nonverbal material) and short-term memory (digit span). Tests of categorical models were used in analyses of potential moderators (clinical variables and study characteristics). RESULTS: The findings revealed a significant and stable association between schizophrenia and memory impairment. The composite effect size for recall performance was large. Recognition showed less, but still significant, impairment. The magnitude of memory impairment was not affected by age, medication, duration of illness, patient status, severity of psychopathology, or positive symptoms. Negative symptoms showed a small but significant relation with memory impairment. CONCLUSIONS: This meta-analysis documented significant memory impairment in schizophrenia. The impairment was stable, wide ranging, and not substantially affected by potential moderating factors such as severity of psychopathology and duration of illness.

Comorbidity↗
PubMed1999

Insulin-like growth factor-I and cognitive function in healthy older men.

The GH/insulin-like growth factor-I (GH/IGF-I) axis is known to be involved in aging of physiological functions. Recent studies indicate that the GH/IGF-I axis may be associated with cognitive functioning. The aim of the present study was to determine whether the age-related decline in circulating levels of IGF-I, as an index of anabolic status, is associated with cognitive functions that are known to decline with aging, but not with cognitive functions not sensitive to aging. Twenty five healthy older men with well-preserved functional ability participated in the study. We also administered neuropsychological tests of general knowledge, vocabulary, basic visual perception, reading ability, visuoconstructive ability, perceptual-motor speed, mental tracking, and verbal long-term memory. Performance on the last four tests decline with aging, whereas the first four of these tests have been shown not to be sensitive to cognitive aging. Mean age of the subjects was 69.1 +/- 3.4 (SD) yr (range 65-76 yr), their mean body mass index was 27.0 +/- 2.4 kg/m2, and their mean IGF-I level was 122 ng/mL (range: 50-220). We found IGF-I levels to be significantly associated with the performances (controlled for education) on the Digit Symbol Substitution test (r = 0.52, P = 0.009) and the Concept Shifting Task (r = -0.55, P = 0.005), which measure perceptual-motor and mental processing speed. Subjects with higher IGF-I levels performed better on these tests, performance on which is known to decline with aging. In conclusion, the results of this study support the hypothesis that circulating IGF-I may play a role in the age-related reduction of certain cognitive functions, specifically speed of information processing.

Aged↗
PubMed1999

Temporal stability of the Launay-Slade Hallucination Scale for high- and low-scoring normal subjects.

It has been documented that many normal people report hallucinatory experiences. The Launay-Slade Hallucination Scale is widely used to investigate differences between subjects who score high or low in hallucinatory predisposition. In this study we addressed the question of whether scores remain stable over time. We selected 19 high-scoring subjects and 17 low-scoring subjects (upper and lower quartile) from a group of 243 undergraduate students who completed the scale. These two groups retook the scale after a period of 3 to 6 weeks. 81% received the same classification, which supports the view of hallucinatory predisposition as a stable trait; however, for 30% of the subjects the mean rating at the second time differed more than 3 SDs from the mean rating at the first time. In addition, the mean rating of 19% of subjects changed enough so they did not receive the same classification, indicating that state characteristics may also affect these scores.

Adult↗
PubMed1998

Specific methylation patterns in two control regions of Epstein-Barr virus latency: the LMP-1-coding upstream regulatory region and an origin of DNA replication (oriP).

The Epstein-Barr virus (EBV) can establish at least four different forms of latent infection. Previously, we have shown that the level of methylation of the EBV genome varies, depending on the form of latency. The methylation status of CpGs was analyzed by the bisulfite genomic sequencing technique in four different cell types representing different forms of latency. The dyad symmetry element of the origin of replication (oriP) region and the latent membrane protein 1 (LMP-1) regulatory sequence (LRS) were studied. The dyad symmetry element has four binding sites for EBNA-1. In a cell with type I latency, a region upstream of the dyad symmetry element was highly methylated, whereas the dyad symmetry element was unmethylated in the EBNA-1-binding region. The LRS was extensively methylated in the LMP-1-negative cell line Rael, in contrast to a LMP-1-expressing nasopharyngeal carcinoma tumor (NPC C15), which was almost completely unmethylated. The methylation pattern of LRS in type I and type III Burkitt lymphoma cells of similar parental origins confirmed that demethylation of some regions takes place upon phenotypic drift.

DNA Methylation↗
PubMed1997

Prevention of child sexual abuse victimization: a meta-analysis of school programs.

OBJECTIVE: The aim of this article was to provide data about the effects of child sexual abuse prevention programs. A more specific aim was to estimate the contribution of potential moderator variables such as age, program duration, or sample size to effect size. METHOD: A meta-analytic approach was used to calculate post-test and follow-up effect sizes of 16 evaluation studies of school programs aimed at the prevention of child sexual abuse victimization. Tests of categorical models were used in the analysis of moderator variables. Multiple regression analysis was used to determine their association with effect sizes. RESULTS: Significant and considerable mean post-intervention (d = .71) and follow-up (d = .62) effect sizes were found, indicating that victimization prevention programs are successful in teaching children sexual abuse concepts and self-protection skills. Intervention characteristics such as duration and content of the program, and child characteristics such as age and SES were important moderators of effect size. CONCLUSIONS: Our findings corroborate and refine the positive conclusions of traditional narrative reviews. Programs that focus on skill training, allowing sufficient time for children to integrate self-protection skills into their cognitive repertoire, are to be preferred. Future evaluation research should focus on transfer of training.

Child↗
PubMed1997

A cost-benefit analysis of programmatic use of CVD 103-HgR live oral cholera vaccine in a high-risk population.

BACKGROUND: Cholera spread to Latin America in 1991; subsequently, cholera vaccination was considered as an interim intervention until long-term solutions involving improved water supplies and sanitation could be introduced. Three successive summer cholera outbreaks in northern Argentina and the licensing of the new single-dose oral cholera vaccine, CVD 103-HgR, raised questions of the cost and benefit of using this new vaccine. METHODS: This study explored the potential benefits to the Argentine Ministry of Health of treatment costs averted, versus the costs of vaccination with CVD 103-HgR in the relatively confined population of northern Argentina affected by the cholera outbreaks. Water supplies and sanitation in this area are poor but a credible infrastructure for vaccine delivery exists. RESULTS: In our cost-benefit model of a 3-year period (1992-1994) with an annual incidence of 2.5 case-patients per 1000 population and assumptions of vaccine efficacy of 75% and coverage of 75%, vaccination of targeted high risk groups would prevent 1265 cases. CONCLUSION: Assuming a cost of US$602 per treated case and of US$1.50 per dose of vaccine, the total discounted savings from use of vaccine in the targeted groups would be US$132,100. The projected savings would be altered less by vaccine coverage (range 75-90%) or efficacy (60-85%) changes than by disease incidence changes. Our analysis underestimated the true costs of cholera in Argentina because we included only medical expenditures; Indirect losses to trade and tourism had the greatest economic impact. However, vaccination with CVD 103-HgR was still cost-beneficial in the base case.

Adolescent↗