Aging affects oxidative state in hippocampus, hypothalamus and adrenal glands of Wistar rats.

The aging process is associated with cognitive impairment and dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis, as well as with oxidative stress. We determined some parameters of oxidative stress in homogenates of hippocampus, hypothalamus and adrenal glands from male 2-, 6- and 24-months-old Wistar rats. A significant age-dependent increase in the generation of free radicals was observed in hippocampus, hypothalamus and adrenal glands, as well as on lipid peroxidation in hippocampus and hypothalamus. The glutathione peroxidase (GPx) activity was significantly reduced in hypothalamus and hippocampus from 6-months-old rats; a decline on GPx and catalase activities in adrenal glands of 24-months-old animals was also present. Interestingly, a great decrease in total antioxidant capacity was found in all tissues tested. Reported findings support the idea that oxidative events participate on multiple neuroendocrine-metabolic impairments and suggest that the oxidative stress found in hippocampus, hypothalamus and adrenals might be associated with age-related physiological deficits.

Repeated stress effects on nociception and on ectonucleotidase activities in spinal cord synaptosomes of female rats.

It has been reported that animals submitted to repeated restraint stress present various adaptation responses which are dependent on the sex. These adaptations include changes in nociception and adenine nucleotide hydrolysis. In this study, we report the effect of chronic administration of a gonadal steroid (17beta-estradiol) on ATP, ADP and AMP hydrolysis in spinal cord synaptosomes of adult ovariectomized (OVX) Wistar rats submitted to repeated restraint stress over 40 days. We also measured nociceptive threshold in these animals using the tail-flick test. The results show that tail-flick latencies were decreased in both stressed groups, OVX and OVX rats receiving estradiol replacement therapy, indicating reduced nociceptive threshold after exposure to repeated stress. Repeated restraint stress caused no effect on ATPase or ADPase activities. On the other hand, AMP hydrolysis in spinal cord synaptosomes from repeatedly stressed rats was decreased in OVX rats compared to non-stressed OVX ones, indicating reduced extracellular adenosine production; this effect was reversed by hormonal replacement. These observations suggest that nociceptive sensitivity to noxious stimuli is affected by repeated stress and that modulation of neurotransmission by adenine nucleotides in spinal cord may be altered by the interaction of sexual hormones and psychological factors, such as exposure to stress.

Stress regulates the lymphocyte homing receptor CD62L (L-selectin).

Based on a previous study showing that panic disorder patients had increased expression of na ve phenotype lymphocytes (CD45RA+ and CD62L+), increased plasma cortisol, as well as decreased interleukin-2 (IL-2) producion, we hypothesized that changes in the percentage of expression of these lymphocyte surface molecules could be related to the substances released by the hypothalamic-pituitary-adrenal (HPA) axis and possibly associated to panic disorder (cortisol, IL-2, serotonin and epinephrine). In order to study the altered expression, blood mononuclear cells of normal volunteers were stimulated with mitogen, in the presence of dexamethasone, IL-2, serotonin and epinephrin. CD62L is decreased by IL-2 in vitro. Serotonin and epinephrine did not promote changes in the expression of these surface molecules. The results of the ex vivo study are in agreement with a previous clinical study with panic patients. It could be suggested that stress is responsible for certain immunologic dysfunctions and new studies should be conducted.

Coumestrol has neuroprotective effects before and after global cerebral ischemia in female rats.

Global ischemia arising during cardiac arrest or cardiac surgery causes highly selective, delayed death of hippocampal CA1 neurons. Phytoestrogens are naturally occurring plant-derived compounds that are present in the human diet and are considered selective estrogen receptor (ER) modulators. The phytoestrogen coumestrol is a potent isoflavonoid, with binding affinities for both ER-α and ER-ß that are comparable to those of 17 b-estradiol. The present study examined the hypothesis that coumestrol protects hippocampal neurons in ovariectomized rats in a model of cerebral global ischemia. Ovariectomized rats were subjected to global ischemia (10 min) or sham surgery and received a single intracerebroventricular or peripheral infusion of 20 µg of coumestrol, 20 µg of estradiol or vehicle 1h before ischemia or 0 h, 3h, 6h or 24h after reperfusion. Estradiol and coumestrol afforded significant neuroprotection in all times of administration, with the exception of estradiol given 24h after the ischemic insult. Animals received icv infusion of the broad-spectrum ER antagonist ICI 182,780 (50 µg) or vehicle into the lateral ventricle just before the E2 or coumestrol administration. The ER antagonist abolished estradiol protection, consistent with a role of classical ERs. In contrast, ICI 182,780 effected only partial reversal of the neuroprotective actions of coumestrol, suggesting that other cellular mediators in addition to classical ERs may be important. Additional research is needed to determine the molecular targets mediating the neuroprotective action of coumestrol and the therapeutic potential of this phytoestrogen in the mature nervous system.

Estudo do perfil do trauma raquimedular em Porto Alegre / The profile os spinal injuries in Porto Alegre / Estudio del perfil de trauma raquimedular en Puerto Alegre

Este estudo de coorte retrospectivo foi desenvolvido com o objetivo de traçar o perfil da população que sofreu trauma raquimedular (TRM) e foi internada em hospitais de pronto atendimento de Porto Alegre/RS. O perfil da população que sofreu TRM de janeiro de 2005 a janeiro de 2010 foi investigado retrospectivamente a partir da coleta de dados em registros médicos. Foram analisados 1320 prontuários, dos quais 63,3% eram do sexo masculino, com média de idade de 47,02±19,60 anos. Os mecanismos de TRM que prevaleceram foram queda de altura (27,2%), acidente de trânsito (25,8%) e queda da própria altura (13,2%), e os níveis da coluna vertebral mais acometidos foram lombar (35,6%), torácico (21,9%) e cervical (20,5%). Da amostra total, 10,7% dos indivíduos que sofreram TRM apresentaram lesão medular (LM), com maior prevalência da lesão incompleta (63,3%). O TRM em Porto Alegre acomete principalmente homens na meia-idade, que tiveram na queda de altura a etiologia mais frequente e no nível lombar o mais acometido. A LM ocorreu mais em indivíduos jovens, sendo o nível cervical o mais lesado. Esses achados são importantes para orientar a alocação eficiente de recursos para o manejo desses agravos e suas repercussões e para prevenir a sua ocorrência nas populações em risco...

This transversal study aimed at determining the profile of the population who suffered spinal injury (SI) and was admitted to emergency hospitals in Porto Alegre/RS. The profile of the population who had SI between January 2005 and January 2010 was retrospectively investigated through data collected from medical records. A total of 1320 records were analyzed, of which 63.3% were male, with a mean age of 47.02±19.6 years. The most prevalent SCI mechanisms were falls from a height (27.2%), traffic accidents (25.8%) and falls from own height (13.2%) and the spinal levels that are usually affected were lumbar (35, 6%), thoracic (21.9%) and cervical (20.5%). Only 142 (10.7%) individuals who had a SI had spinal cord injury (SCI), with a higher prevalence of incomplete lesion (63.3%). In Porto Alegre SI affects mainly middle aged men, who fell from a height and had the lumbar level as the most affected. The SCI affects younger individuals at the cervical level. These findings are important to guide the efficient allocation of resources for the management of these injuries and their repercussions and to prevent this kind of event in the risk population...

Este estudio transversal fue desarrollado con el objetivo de trazar el perfil de la población que sufrió trauma raquimedular (TRM) y fue internado en hospitales de emergencia de Puerto Alegre/RS. El perfil de la población que sufrió TRM de enero de 2005 a enero de 2010 fue investigado retrospectivamente a partir de la recopilación de datos en registros médicos. Fueron analizadas 1320 fichas clínicas, de las cuales 63,3% eran de sexo masculino, con promedio de edad de 47,02±19,6 años. Los mecanismos de TRM que prevalecieron fueron caída de gran altura (27,2%), accidente de tránsito (25,8%) y caída desde la propia altura del sujeto (13,2%) y los niveles de la columna vertebral más lesionados fueron lumbar (35,6%), torácico (21,9%) y cervical (20,5%). De la muestra total, 142 (10,7%) de los individuos que sufrieron TRM presentaron lesión medular (LM), con mayor prevalencia de lesión incompleta (63,3%). El TRM en Puerto Alegre ocurre principalmente en hombres en edad media, que tuvieron una caída de gran altura, la cual constituye la etiología más frecuente y el nivel lumbar es el más lesionado. Estos hallazgos son importantes para orientar la asignación eficiente de los recursos para el manejo de estas lesiones y sus consecuencias para prevenir su incidencia en la población en riesgo...

Parâmetros hemodinâmicos e hemometabólicos na isquemia cerebral traumática / Hemodynamic and metabolic parameters in brain

Introdução: O estudo de medidas indiretas do metabolismo cerebral, como a pressão de perfusão cerebral (PPC), pressão intracraniana (PIC), pressão arterial de CO2 (PaCO2) e pressão arterial média (PAM), é necessário para guiar o tratamento e prevenir a ocorrência de dano isquêmico secundário.O objetivo deste estudo foi analisar a associação entre os parâmetros hemometabólicos e a ocorrência de isquemia cerebral traumática. Métodos: Trinta um pacientes foram prospectivamente seguidos nas Unidades de Tratamento Intensivo Pediátrico e do Trauma do Hospital de Pronto Socorro de Porto Alegre de abril a dezembro de 2003. Vinte e três adultos (17 a 56 anos de idade) e 8 crianças ( 3 a 13 anos de idade) com traumatismo craniano grave foram avaliados.Os critérios de inclusão foram escore < oito na Escala de Coma de Glasgow e tomografia computadorizada de crâneo alterada. Foram monitorizados a PIC, PAM, PaCO2 e PPC.Resultados: A idade média foi 24 anos. Isquemia Cerebral foi identificada em 13 (56,5) adultos e em sete (87,5) crianças.A queda da PAM foi associada com a mortalidade (p<=0,005) em crianças. A elevação da PIC (p= 0,03) e a queda da PPC (p=0, 007) em adultos foram associadas com isquemia cerebral. Dos 14 pacientes (45,2) que morreram, 13 (56,5)eram adultos, e um (12,5) paciente era criança. Pacientes adultos com baixa PPC apresentam pior prognóstico com elevação dos índices de mortalidade (p=0, 045). Conclusão: A elevação da PIC e da PAM e a queda da PPC estão associadas com a isquemia cerebral traumática nestes pacientes e com maior taxa de mortalidade.

Stress regulates the lymphocyte homing receptor CD62L (L-selectin)

Based on a previous study showing that panic disorder patients had increased expression of naïve phenotype lymphocytes (CD45RA+ and CD62L+), increased plasma cortisol, as well as decreased interleukin-2 (IL-2) producion, we hypothesized that changes in the percentage of expression of these lymphocyte surface molecules could be related to the substances released by the hypothalamic-pituitary-adrenal (HPA) axis and possibly associated to panic disorder (cortisol, IL-2, serotonin and epinephrine). In order to study the altered expression, blood mononuclear cells of normal volunteers were stimulated with mitogen, in the presence of dexamethasone, IL-2, serotonin and epinephrin. CD62L is decreased by IL-2 in vitro. Serotonin and epinephrine did not promote changes in the expression of these surface molecules. The results of the ex vivo study are in agreement with a previous clinical study with panic patients. It could be suggested that stress is responsible for certain immunologic dysfunctions and new studies should be conducted

Hipóteses fisiopatológicas da depressäo unipolar: estado atual / Physiopathological hypotesis of unipolar depression: present status

Apresenta-se uma revisäo dos aspectos neuroquímicos e psiconeuroendócrinos envolvidos na depressäo unipolar. Säo discutidos o metabolismo dos neurotransmissores, balanço de receptores, interaçäo entre os sistemas noradrenégicos e serotonérgicos e alguns aspectos da fisiologia da membrana neuronal. É dada especial ênfase aos testes endócrinos utilizados nos diagnósticos da doença depressiva e sua importância para o estabelecimento de hipóteses fisiopatológicas é discutido

Age-related concentrations of glycosaminoglycans in Random urine: a contribution to the lavoratorial detection of mucopolysaccharidoses

As mucopolissacridoses (MPS) säo rotineiramente detectadas pela dosagem de glicosaminoglicanos (GAG), usualmente realizadas em urina de 24 horas. Como os pacientes suspeitos säo geralmente crianças sem controle miccional e a excreçäo de GAG varia com a idade, nós estudamos os valores de GAG em amostras ocasionais de urina de 78 crianças normais e de 16 pacientes com MPS de 6 meses a 12 anos de idade. Este trabalho teve objetivos (a) estabelecer valores normais para os índices urinários GAG/volume (GAG/L e GAG/cratinina (GAG/creat), relacionados com a idade, e (b) testar a utilidade desses índices na identificaçäo de pacientes com MPS. Nos dois índices a concentraçäo de GAG diminui com a idade. Os índices GAG/L e GAG/CREAT discriminaram todos os pacientes, com uma exceçäo em cada índice, em pacientes diferentes. Nossos resultados indicam que amostras ocasionais de urina säo adequadas para a dosagem de GAG desde que os índices de GAG/L e GAG/CREAT sejam avaliados simultanemante e que a idade do paciente seja considerada na interpretaçäo dos resultados, especialmente em crianças pequenas