Vitamin A deficiency in preschool children of Recife, Northeast of Brazil

Vitamin A deficiency in preschool children of Recife, Northeast of Brazil. The purpose of the study was to evaluate the extent of vitamin A deficiency (VAD) among preschool children in the city of Recife, Northeast Brazil. The sample comprised 344 children of both sexes, 24 to 60 months old, in 18 public day care centres in the city of Recife, in 2007. The nutritional status of vitamin A was assessed by biochemical (serum retinol) and dietetic (vitamin A rich-food consumption) indicators and the pondo-stature status through anthropometric indicators weight-for-age, height-for-age and weight-for-height. The prevalence of hyporetinolemia (<0.70 mu mol / L) was 7.7% (IC95% 4.88 - 11.81), which characterizes the VAD as a light-type public health problem, according to World Health Organization criteria. On the other hand, 29.6% (IC95% 24.22 - 35.63) of children had acceptable or marginal levels (0.70 to 1.04 mu mol/L) of retinol. Regarding the vitamin A rich-food intake, values below the EAR (Estimated Average Requirement) - 210 mu g/day for children of 1 to 3 years old and 275 mu g/day for children of 4 to 8 years old - were 8.1% and 21.3% respectively. The prevalence of anthropometrical deficits (<-2 scores -Z) in preschool children were 2.5% for the indicator weight-for-age, 8.6% for height-for-age and 1.5% for weight-for-height. The research findings point out to the importance of institutionalization for the appropriate nutritional status of children and maintenance of adequate reserves of vitamin A. However, more studies are needed focusing on non-institutionalized preschool, or children living outside the privileged environment of public day care centres.

Work and Excessive Sleepiness among Brazilian Evening High School Students Effects on Days Off

Previous studies have revealed that students who work and study build up sleep deficits during the workweek, which can trigger a sleep rebound during days off. The objective of this study was to investigate the impact of working/non-working on sleepiness during days off among high school students. The study population, aged 14-21 years, attended evening classes in Sao Paulo, Brazil. For the study, the students completed questionnaires on living conditions, health, and work; wore actigraphs; and completed the Karolinska Sleepiness Scale (KSS). To predict sleepiness, a logistic regression analysis was performed. Excessive sleepiness was observed on the first day off among working students. Results suggest that working is a significant predictor for sleepiness and that two shifts of daily systematic activities, study and work, might lead to excessive daytime sleepiness on the first day off. Further, this observed excessive sleepiness may reflect the sleep debt accumulated during the workweek.

The bubbles or the boiling pot? An ecosystemic approach to culture, environment and quality of life

For the diagnosis and prognosis of the problems of quality of life, a multidisciplinary ecosystemic approach encompasses four dimensions of being-in-the-world, as donors and recipients: intimate, interactive, social and biophysical. Social, cultural and environmental vulnerabilities are understood and dealt with, in different circumstances of space and time, as the conjugated effect of all dimensions of being-in-the-world, as they induce the events (deficits and assets), cope with consequences (desired or undesired) and contribute for change. Instead of fragmented and reduced representations of reality, diagnosis and prognosis of cultural, educational, environmental and health problems considers the connections (assets) and ruptures (deficits) between the different dimensions, providing a planning model to develop and evaluate research, teaching programmes, public policies and field projects. The methodology is participatory, experiential and reflexive; heuristic-hermeneutic processes unveil cultural and epistemic paradigms that orient subject-object relationships; giving people the opportunity to reflect on their own realities, engage in new experiences and find new ways to live better in a better world. The proposal is a creative model for thought and practice, providing many opportunities for discussion, debate and development of holistic projects integrating different scientific domains (social sciences, psychology, education, philosophy, etc.).

Temporal lobe epilepsy and social behavior: An animal model

Social behavior depends on the integrity of social brain circuitry. The temporal lobe is an important part of the social brain, and manifests morphological and functional alterations in autism spectrum disorders (ASD). Rats with temporal lobe epilepsy (TLE), induced with pilocarpine, were subjected to a social discrimination test that has been used to investigate potential animal models of ASD, and the results were compared with those for the control group. Rats with TLE exhibited fewer social behaviors than controls. No differences were observed in nonsocial behavior between groups. The results suggest an important role for the temporal lobe in regulating social behaviors. This animal model might be used to explore some questions about ASD pathophysiology. (c) 2008 Elsevier Inc. All rights reserved.

Differential response of AMPA and NMDA glutamate receptors of Purkinje cells to aging of the chicken cerebellum

Aging can lead to cognitive, affective, learning, memory and motor deficits. Since the cerebellum and glutamatergic neurotransmission are involved in several of those functions, the present work aimed at studying the expression of AMPA and NMDA glutamate receptor subunits in the chick cerebellum during aging. Young (30 days old) and aged (ca. 4 years old) chickens (Gallus gallus) were used in order to evaluate the expression of GluR1, GluR2/3 and NR1 subunits. The cerebella of young and aged chickens were subjected to immunohistochemical and immunoblotting techniques. Numbers of GluR1, GluR2/3 and NR1-positive cells and optical density of the immunoblotting data were analyzed and submitted to statistical analysis using ANOVA and the Bonferroni post hoc test. Mean density of Purkinje cells stained for Giemsa, GluR1, GluR2/3 and NR1 in the cerebellum all showed a statistically significant decrease in aged animals when compared to the young animals (Giemsa, P < 0.01; GluRs and NR1, P < 0.03). However, the ratio of GluR1 and GluR2/3-positive Purkinje cells in relation the total number of Purkinje cells found in each time point decreased with aging (ca. 10%), whereas the ratio of NR1-positive cells increased (ca. 9%). The immunoblotting data showed a significant decrease of GluR1 (ca. 66%) and GluR2/3 (ca. 55%) protein expression with aging, but did not reveal changes for NR1. Our data suggest that aging can lead to differential changes in the pattern of expression of glutamate receptor subunits, which can underlie at least part of the cognitive and motor disorders found in aged animals. (c) 2010 Elsevier Ireland Ltd. All rights reserved.

Circadian phase and intertrial interval interfere with social recognition memory

A modified version of the social habituation/dis-habituation paradigm was employed to examine social recognition memory in Wistar rats during two opposing (active and inactive) circadian phases, using different intertrial intervals (30 and 60 min). Wheel-running activity was monitored continuously to identify circadian phase. To avoid possible masking effects of the light-dark cycle, the rats were synchronized to a skeleton photoperiod, which allowed testing during different circadian phases under identical lighting conditions. In each trial, an infantile intruder was introduced into an adult`s home-cage for a 5-minute interaction session, and social behaviors were registered. Rats were exposed to 5 trials per day for 4 consecutive days: oil days I and 2, each resident was exposed to the same intruder; on days 3 and 4, each resident was exposed to a different intruder in each trial. I he resident`s social investigatory behavior was more intense when different intruders were presented compared to repeated presentation of the same intruder, suggesting social recognition memory. This effect was stronger when the rats were tested during the inactive phase and when the intertrial interval was 60 min, These findings Suggest that social recognition memory, as evaluated in this modified habituation/dis-habituation paradigm, is influenced by the circadian rhythm phase during which testing is performed, and by intertrial interval. (C) 2008 Elsevier Inc. All rights reserved.

Neuropsychological Assessment of Current and Past Crack Cocaine Users

Background: Cognitive changes due to crack cocaine consumption remain unclear Methods: For clarification, 55 subjects were assigned to three groups: control group, crack cocaine current users, and ex-users. Participants were submitted to Mini-Mental State Examination (MMSE) and tasks evaluating executive functioning and verbal memory Mood state was also measured. Intergroup comparisons were carried out. Results: Control group performance on the MMSE was better than that of users and ex-users. Verbal memory performance for logical memory of users was impaired. Ex-users scored lower on DSST and Trail Making Test (Part B). Conclusion: Chronic crack cocaine use seems to disrupt general cognitive functioning (MMSE), verbal memory, and attentional resources, but findings suggest that some of these effects could be reversed by abstinence.

Mitochondrial energy metabolism in neurodegeneration associated with methylmalonic acidemia

Methylmalonic acidemia is one of the most prevalent inherited metabolic disorders involving neurological deficits. In vitro experiments, animal model studies and tissue analyses from human patients suggest extensive impairment of mitochondrial energy metabolism in this disease. This review summarizes changes in mitochondrial energy metabolism occurring in methylmalonic acidemia, focusing mainly on the effects of accumulated methylmalonic acid, and gives an overview of the results found in different experimental models. Overall, experiments to date suggest that mitochondrial impairment in this disease occurs through a combination of the inhibition of specific enzymes and transporters, limitation in the availability of substrates for mitochondrial metabolic pathways and oxidative damage.

Evidence that OGG1 glycosylase protects neurons against oxidative DNA damage and cell death under ischemic conditions

7,8-Dihydro-8-oxoguanine DNA glycosylase (OGG1) is a major DNA glycosylase involved in base-excision repair (BER) of oxidative DNA damage to nuclear and mitochondrial DNA (mtDNA). We used OGG1-deficient (OGG1(-/-)) mice to examine the possible roles of OGG1 in the vulnerability of neurons to ischemic and oxidative stress. After exposure of cultured neurons to oxidative and metabolic stress levels of OGG1 in the nucleus were elevated and mitochondria exhibited fragmentation and increased levels of the mitochondrial fission protein dynamin-related protein 1 (Drp1) and reduced membrane potential. Cortical neurons isolated from OGG1(-/-) mice were more vulnerable to oxidative insults than were OGG1(+/+) neurons, and OGG1(-/-) mice developed larger cortical infarcts and behavioral deficits after permanent middle cerebral artery occlusion compared with OGG1(+/+) mice. Accumulations of oxidative DNA base lesions (8-oxoG, FapyAde, and FapyGua) were elevated in response to ischemia in both the ipsilateral and contralateral hemispheres, and to a greater extent in the contralateral cortex of OGG1(-/-) mice compared with OGG1(+/+) mice. Ischemia-induced elevation of 8-oxoG incision activity involved increased levels of a nuclear isoform OGG1, suggesting an adaptive response to oxidative nuclear DNA damage. Thus, OGG1 has a pivotal role in repairing oxidative damage to nuclear DNA under ischemic conditions, thereby reducing brain damage and improving functional outcome. Journal of Cerebral Blood Flow & Metabolism (2011) 31, 680-692; doi:10.1038/jcbfm.2010.147; published online 25 August 2010

Tempol ameliorates murine viral encephalomyelitis by preserving the blood-brain barrier, reducing viral load, and lessening inflammation

Multiple sclerosis (MS) is a progressive inflammatory and/or demyelinating disease of the human central nervous system (CNS). Most of the knowledge about the pathogenesis of MS has been derived from murine models, such as experimental autoimmune encephalomyelitis and vital encephalomyelitis. Here, we infected female C57BL/6 mice with a neurotropic strain of the mouse hepatitis virus (MHV-59A) to evaluate whether treatment with the multifunctional antioxidant tempol (4-hydroxy-2,2,6,6-tetramethyl-1-piperidinyloxy) affects the ensuing encephalomyelitis. In untreated animals, neurological symptoms developed quickly: 90% of infected mice died 10 days after virus inoculation and the few survivors presented neurological deficits. Treatment with tempol (24 mg/kg, ip, two doses on the first day and daily doses for 7 days plus 2 mM tempol in the drinking water ad libitum) profoundly altered the disease outcome: neurological symptoms were attenuated, mouse survival increased up to 70%, and half of the survivors behaved as normal mice. Not Surprisingly, tempol substantially preserved the integrity of the CNS, including the blood-brain barrier. Furthermore, treatment with tempol decreased CNS vital titers, macrophage and T lymphocyte infiltration, and levels of markers of inflammation, such as expression of inducible nitric oxide synthase, transcription of tumor necrosis factor-alpha and interferon-gamma, and protein nitration. The results indicate that tempol ameliorates murine viral encephalomyelitis by altering the redox status of the infectious environment that contributes to an attenuated CNS inflammatory response. overall, our study supports the development of therapeutic strategies based on nitroxides to manage neuroinflammatory diseases, including MS. (C) 2009 Elsevier Inc. All rights reserved.