Letícia Forster

Behavioural effects of acute tryptophan depletion in healthy male volunteers.

Acute tryptophan depletion (ATD) studies have been used to assess the role of the serotonergic system in various aspects of human behaviour. Changes in mood have already been described in selected groups of individuals submitted to ATD. The present study was a randomized, double-blind, cross-over trial designed to evaluate the effects of ATD on mood, memory, attention and induced anxiety in normal male volunteers. Twelve healthy male volunteers were submitted to two separate sessions of ATD, 1 week apart. Drinks containing either a balanced mixture of amino acids (B) or a similar mixture devoid of tryptophan (T–) were administered in each session. Mood was assessed using self-rating scales. Attention and memory were assessed using a battery of psychological tests. Anxiety induction was carried out using a simulation of public speaking. Blood levels of tryptophan were assessed before and after the B and T– drinks. Results showed that ATD markedly decreased plasma tryptophan (p< 0.0001). Mood ratings, memory and attention were not changed by the T– drink. There was no difference among the anxiety levels measured under T– or B mixtures. These data supports the notion that ATD does not change mood and cognitive function in healthy subjects.

Behavioural effects of acute phenylalanine and tyrosine depletion in healthy male volunteers.

Acute phenylalanine and tyrosine depletion (APTD) studies have been used to assess the role of the cathecholaminergic system in various aspects of human behaviour. In this study we conducted a randomized, double-blind, controlled and cross-over comparison to evaluate the effects of APTD on memory, attention and mood in normal subjects. Twelve healthy male volunteers were included in this study. The subjects ingested a nutritionally balanced mixture (B) or a similar mixture deficient in phenylalanine and tyrosine (PT–). Before and 5 h after ingestion of the drink, volunteers underwent tests on mood, memory and attention. Results of the memory tests showed that PT– mixture impaired word recall as measured in Reys test (p = 0.016). The assessment of changes in mood showed that the balanced mixture improved scores of as alertness (VAMS factor I, p = 0.037) and the PT– mixture induces an opposite effect, increased scores of anxiety (Profiles of Mental State composed-anxious dimension, p= 0.022). These results suggest that tyrosine plasma levels and cathecholamines may be important factors in regulating mood and memory.

The impact of living on the streets on latency children's friendships

OBJECTIVE This is a study to evaluate friendships in latency street boys of Porto Alegre, RGS, Brazil. METHODS A sample of 30 latency street boys was compared with a sample of 51 latency boys living with their low income families, using the Cornell Interview of Peers and Friends (CIPF). RESULTS The two groups had a significantly different CIPF global scores, and the boys of the street group had the highest mean score. Also, boys of the street had significantly lower developmental appropriateness, self-esteem and social skills scores than boys living with a family. CONCLUSIONS The urgent need for intervention street children, especially on boys of the street, is emphasized.

Neuropsychiatric symptoms as the main determinant of caregiver burden in Alzheimer's disease

Caregiver burden is common in Alzheimer’s disease (AD), decreasing the quality of life among caregivers and patients. Projections of aging and aging-related diseases such as AD in developing countries justify additional data about this issue because people living in these countries have shown similarly high levels of caregiver strain as in the developed world. Objective The aim of this study was to analyze the association of AD caregivers’ burden with patients’ neuropsychiatric symptoms (NPS), cognitive status, severity of dementia, functional capacity, caregiver sociodemographic characteristics, and the characteristics of care provided by caregivers. Methods A cross-sectional study was conducted in a sample of 39 consecutive AD patients and their primary caregivers. NPS were evaluated using the Neuropsychiatric Inventory (NPI). Severity of dementia was assessed with the Clinical Dementia Rating (CDR) scale. Functional capacity was assessed using the Katz and Lawton scales. The burden level was rated using the Burden Interview (BI). Sociodemographic characteristics of caregivers and the characteristics of care provided by them were evaluated. The Mann-Whitney U-test, Kruskal-Wallis test and Spearman’s rho coefficient were performed. Results The BI had a moderate correlation with NPI intensity (rho=0.563), p<001. Female caregivers reported a greater level of burden (p=0.031) than male caregivers. The other variables were not significantly associated to caregiver burden. Conclusion NPS were the main determinant of burden in primary caregivers of AD patients. This result underscores the need for prevention and treatment of these symptoms. Sex also had an effect on caregiver burden, but the small male sample in this study precludes the generalization of this finding.

Sociodemographic profile and level of burden of dementia patients' caregivers who participate in a support group

The Brazilian Alzheimer’s Association recommend the dementia patient’s caregiver to attend group meetings which aim to give information and enable them to express and share feelings with individuals who are facing similar difficulties. Objectives To identify the sociodemographic profile of the individuals who attend the Support Group for Family Members of Individuals with Alzheimer’s disease at Hospital de Clínicas de Porto Alegre, and to verify the degree of burden associated to the care given to this kind of patient. Methods Forty-eight participants were sub-divided into two groups: 23 non-caregivers and 25 caregivers. All participants answered a sociodemographic questionnaire, and the caregivers also answered the Zarit Burden Interview (ZBI). Student’s t test was used for comparison of parametric data, and Chi-square test for categorical data between caregivers and non-caregivers. Spearman’s rho correlation analysis was performed for the ZBI and the studied variables. Results Participants were predominantly women. Only age differentiated one subgroup from the other. The mean score on the ZBI was 35.1 (14.7), and most of the caregivers presented up to moderate burden. Conclusions Women attended the Support Group either as caregiver or non-caregiver. The level of burden among caregivers of high educational attainment was relatively high besides the short time as caregiver (up to a year).

Toxicologia do tolueno: aspectos relacionados ao abuso

O tolueno esta presente em muitos produtos de uso domestico e industrial e e o principal solvente envolvido no abuso de substâncias e na exposicao ocupacional. O problema mais grave no estudo de patologias relacionadas ao tolueno e que este esta geralmente associado, em suas preparacoes comerciais, a outras substâncias. O potencial toxico do tolueno foi abordado nos seguintes aspectos: parâmetros farmacologicos; caracteristicas fisico-quimicas; exposicao; estudos clinicos; diagnostico; pesquisa experimental; tolerância e dependencia; efeitos agudos e cronicos; neurotoxicidade; teratogenicidade; doencas psiquiatricas; carcinogenicidade e tratamento. Conclui-se ser de grande importância e urgencia que se realizem estudos clinicos com amostras maiores para definicao mais precisa das consequencias do uso cronicoToluene, present in many industrial and domestic products, is the main solvent involved in solvent abuse and occupational exposure. The main problem in studying toluene-related pathologies is the fact that it is frequently combined with other substances. This review focuses on its potential toxicity. The following subjects are discussed: pharmacologic parameters; physico-chemical features; exposure; clinical trials; experimental research; diagnosis; tolerance and dependence; acute and chronic effects; neurotoxicity; teratogenicity; psychiatric disorders; carcinogenicity; and treatment. It is concluded that is important more research on larger population samples with a view to better definition of the consequences of chronic use should be undertaken.

Correlation between serum brain-derived neurotrophic factor and verbal fluency

ering “probable AD” alone as well as “probable” plus “ possible” AD. The neuropathological diagnosis of AD was defined using multiple combinations of CERAD neuritic plaque density scores and Braak neurofibrillary tangle stages.Results:The sensitivity of the clinical diagnosis of AD ranged from 65% to 87% while specificity ranged from 64% to 78%. Sensitivity was increased with more permissive clinical criteria and specificity was increased with more restrictive criteria while the opposite was true for neuropathological criteria. The highest combined diagnostic performance (sensitivity of 79% and specificity of 71%) was achieved when the clinical diagnosis was defined as including both probable and possible AD and the neuropathological diagnosis was defined as being inclusive of the following two situations: 1) frequent neuritic plaque density with Braak stage III-VI 2) moderate neuritic plaque density with Braak stage V or VI. Conclusions: Agreement between the clinical and neuropathological definitions of AD, based on data from NIA ADC’s, varies depending on the levels of clinical and neuropathological confidence, with sensitivities and specificities ranging between 64% and 87%. The rate of misdiagnosis is critical for many types of research, including the calculation of sample size for clinical trials.

Burden interview versus neuropsychiatric inventory: Evaluation of burden in caregivers of Alzheimer's disease patients

This study aims to evaluate patient and caregiver’s characteristics related with neuropsychiatric symptoms. Methods: A cross-sectional study was conducted in a sample of 58 probable Alzheimer’s disease (AD) patients (NINCDS-ADRDA criteria). The neuropsychiatric symptoms were evaluated by the Brazilian version of the Neuropsychiatric Inventory (NPI). The dementia severity was assessed with the Clinical Dementia Rating (CDR), Brazilian version. The analyzed patient’s variables were sex, age, age of onset of AD symptoms and education. The analyzed caregiver’s variables were sex, type of relationship, age, education, time as caregiver, weekly time of care, residing with patient and type of job. Student’s t test and one-way Anova were performed for parametric variables. Spearman’s rho was used for correlations. Results: NPI intensity and distress were similar in both patient’s sex (p 1⁄4 0.742 and p 1⁄4 0.902, respectively) and in the three stages of severity of dementia (F1⁄4 1.951, p1⁄4 0.152; F1⁄4 0.763, p1⁄4 0.471, respectively). Patient’s education was inversely correlated with NPI frequency, intensity and distress (rho1⁄4 -0.283, rho1⁄4 -0.276, rho1⁄4 -0.262, p1⁄4 0.05). NPI intensity and distress were similar in both caregiver’s sex (p1⁄4 0.809 and p1⁄4 0.743, respectively), relationship type (p> 0.5) and caregiver’s type of job (p > 0.5). However, a tendency for statistical difference was observed between caregivers who resided and those who not resided with patients (p 1⁄4 0.05), caregivers who resided with patients showed higher NPI intensity and NPI distress. Caregiver’s education was inversely correlated with NPI frequency, intensity and distress (rho1⁄4 -0.302, rho1⁄4 -0. 272, rho1⁄4 -0. 300, p1⁄4 0.05). Caregiver’s age was inversely correlated with NPI severity (rho 1⁄4 -0.270, p 1⁄4 0.05). Weekly time of care was correlated with NPI frequency (rho 1⁄4 0. 291, p1⁄4 0.05). Conclusions: Some variables may interfere on neuropsychiatric symptoms evaluation by caregivers of AD patients, as age, education, weekly time of care and residing with patients. Some of them can be modified through different approaches improving quality of care.

The education adjusted cut-off point of word span test to screening dementia in a South Brazilian sample

Considering several serious limitations of the MMSE like insensitivity to visuospatial deficits or frontal executive dysfunctions other cognitive assessment test tools were developed to overcome the limitations of MMSE. Methods: Active search for the patients with memory complaints General Practioners and Department of Neurology of Slovak Medical University Neuropsychological screening of investigated patients with neuropsychological tests for determinging global cognitive functions MMSE (Folstein et al., 1975) and ACE-R (Mioshi et al., 2006) Results: In the time period of 1.5 year over 400 patients with memory complaints were screened with neuropsychological screening tests MMSE and ACE-R. The patients with MMSE< 24 and ACE< 88 were further clinically examined by psychiatric, and neurological examination for differential diagnosis of dementia. Conclusions: The assessment of patients with memory complaints by neuropsychological screening tests MMSE and ACE-R to determine the cognitive mental state of the patients clearly demonstrated superior sensitivity of ACE-R over MMSE.