Archive for Fevereiro, 2013


1. Coração: a corrida exige que o coração aumente o fluxo de sangue para todo o corpo. As fibras do músculo se fortalecem e a cavidade aumenta. Há uma hipertrofia excêntrica do miocárdio (alteração na parede e na cavidade do ventrículo esquerdo) melhorando a ejeção sanguínea. Desta forma o coração bombeia mais sangue com menos batidas, se tornando mais eficiente. Com o aumento da circulação sangüínea pelo corpo, cresce a entrada de oxigênio nos tecidos.

2. Pulmões: correr faz com que o volume de ar inspirado seja maior, aumentando a sua capacidade de respiração. Há também um aumento da quantidade de oxigênio absorvido do ar atmosférico.

3. Ossos: estimula a formação de massa óssea, aumentando a densidade óssea evitando problemas como a osteoporose.

4. Pressão arterial: correr estimula a vasodilatação, o que reduz a resistência para a circulação de sangue. Há trabalhos específicos para hipertensos, como trabalhar a velocidade em terrenos planos. Uma maneira de diminuir a sua pressão é trabalhando a velocidade em terrenos plano.

5. Cérebro: aumenta os níveis de serotonina, neurotransmissor que regula o sono e o apetite. Em baixas quantidades, essa substância está associada ao surgimento de problemas como a depressão. 

6. Peso: quanto maior a intensidade do exercício maior a queima calórica e de gordura. A corrida ajuda a gastar muitas calorias, favorecendo a perda ou manutenção do seu peso. Em uma hora de treino, um atleta chega a queimar até 950 calorias. 

7. Colesterol: diminui os níveis de LDL (colesterol “ruim”). Corredores de longas distâncias têm o nível mais alto de HDL (colesterol bom ), encarregado de transportar os ácidos graxos no sangue e de evitar o seu depósito nas artérias.

8. Estresse: com a corrida, há liberação do hormônio cortisol, aliviando o estresse e a ansiedade. 

9. Sono: fazer atividade física, melhora a qualidade de sono. Correr faz a pessoa dormir melhor. Após o exercício, o corpo libera endorfina, substância que provoca a sensação de bem-estar e ajuda a relaxar.

10. Músculos: a corrida ajuda a melhorar a resistência muscular e também queima a gordura dos tecidos musculares, deixando-os mais fortes e definidos. 

11. Rins: com o aumento da circulação, há também uma melhora da função dos rins, que filtram o sangue e reduzem o número de substâncias tóxicas que circulam pelo corpo. 

12. Articulações: correr torna a cartilagem das articulações mais espessa, o que protege melhor essas regiões tão frágeis do nosso corpo. 

13. Aumenta a libido: após 30 minutos de corrida, há um aumento da testosterona que permanece assim, por mais uma hora aproximadamente. No caso das mulheres, também há um aumento dos hormônios relacionados ao desejo, além de aumentar a auto-confiança.

Congresso Brasileiro de Doenças Cerebrovasculares

13-16 novembro 2013

“Todas as especialidades médicas são importantes, mas algumas têm maior amplitude de ação do que outras; e a Neurologia, neste sentido, é uma grande especialidade”

Dr.Ricardo Nitrini

A Neurologia é a especialidade que cuida do sistema nervoso central e periférico, ou seja, de doenças do cérebro, medula, nervos, e até algumas doenças dos músculos. Dessa forma o neurologista clínico se dedica ao estudo e tratamento dos problemas desse nobre segmento do nosso corpo.

Sintomas comuns de quem busca auxílio de um neurologista são, além das dores de cabeça (cefaléia), tonturas, redução de força, redução de sensibilidade, formigamentos, alterações na visuais, tremores, desmaios, perda de memória, alterações da fala e do comportamento e insônia.

 

As doenças mais comuns tratadas pelo neurologista são as dores de cabeça (além de outras dores, apenas para citar dentre um grande grupo: neuralgias, dores cervicais e lombares, afora neuropatias periféricas dolorosas ou não), epilepsia e doenças cerebrovasculares. Afora essas, as doenças que a neurologia e o neurologista mais lidam são os distúrbios do movimento (como tremores e Doença de Parkinson), as demências (como a doença de Alzheimer e várias outras doenças degenerativas), as doenças desmielinizantes (como a Esclerose Múltipla), as doenças neuromusculares e distúrbios do sono.

A neurologia é uma especialidade ampla e tem interface com a clínica médica (sendo um ramo dessa especialidade), psiquiatria, oftalmologia, otorrinolaringologia, traumato-ortopedia, neurocirurgia, dentre outras especialidades médicas. Visto a grande dimensão de atuação do neurologista, esse geralmente tem formação direcionada para atendimento do paciente adulto, ficando reservado comumente o atendimento pediátrico para o neuropediatra.

Vários exames complementares podem ser solicitados, caso seja essencial para esclarecer uma queixa clínica e investigar outros diagnósticos, pelo neurologista, como o estudo do líquor por punção lombar, tomografia de crânio e coluna, ressonância magnética para vários segmentos do sistema nervoso central e periférico, eletroencefalograma, doppler transcraniano, eletroneuromiografia, dentre vários outros.

Se o caso inicialmente clínico for cirúrgico, o neurologista pode encaminhar o paciente para um neurocirurgião da sua confiança, se houver necessidade de intervenção cirúrgica.

Para mais informações, vide este excelente artigo:

Click to access 20-Neurologia.pdf

Procure o seu neurologista caso você apresente algum dos sinais e sintomas citados para ter uma melhor e mais ampla abordagem do seu caso!

 

A protein involved in synaptic structure has been identified as a potential cause of depression, a finding that according to researchers has “enormous therapeutic potential for the development of biomarkers and novel therapeutic agents.”

Investigators at the Mount Sinai School of Medicine in New York City found decreased expression of Rac1 in the postmortem brains of people with major depressive disorder (MDD) and in mice subjected to chronic stress. They were able to control the depressive response in mice by manipulating the expression of Rac1.

The research was published online February 17 in Nature Medicine.“Our study is among only a few in depression research in which 2 independent human cohorts and animal models validate each other. Rac1 has enormous therapeutic potential, and I look forward to investigating it further,” study investigator Scott Russo, PhD, said in a statement.

Looking for Drug Targets

Rac1 is a small Rho GTPase protein involved in modulating synaptic structure.

“There is a hypothesis that depression and stress disorders are caused by a restructuring of brain circuitry,” Dr. Russo explained in an interview with Medscape Medical News.

The scientists subjected mice to repeated bouts of social stress and then evaluated the animals for changes in gene expression in the nucleus accumbens (NAc), the brain’s reward center.

The researchers found that expression of Rac1 was significantly downregulated in the brains of mice for at least 35 days following the end of the chronic social stressor. Rac1 was not affected by only a single episode of stress, indicating that only prolonged stressors that induce depression are capable of downregulating Rac1.

The scientists note that chronic stress in the mice caused epigenetic changes in chromatin that led to Rac1 downregulation.

They were able to control the depressive response to chronic stress to some extent by chronic antidepressant treatment. Histone deacetylase (HDAC) inhibitors were “extremely effective in both normalizing the reduction in Rac1 and also promoting antidepressant responses,” Dr. Russo toldMedscape Medical News.

“What we think is happening is that chronic stress leads to a lasting change in the ability of our genes to transcribe this RAC1 gene, and if you target the epigenome, you can reverse that loss of Rac1 and promote synapses and more normal healthy responses,” he said.

As in the mice, Rac1 expression was also strongly downregulated in the NAc in postmortem brains of patients with MDD, who displayed similar epigenetic changes. In most of the individuals with MDD who were taking antidepressants at the time of death, Rac1 expression was not restored to the levels seen in control participants, “suggesting a need for more direct RAC1-targeting strategies to achieve therapeutic effects,” the authors write.

“Currently, there aren’t any approved drugs or even experimental drugs that target Rac1 that are safe and effective,” Dr. Russo said. “It would be nice if we could team up with some chemists or pharma and figure out if there are some safe and effective Rac activators.”

However, there are caveats to that, he said.

“It might be difficult to target Rac specifically, because it is involved in cell proliferation and restructuring so it may be difficult to get a compound that doesn’t cause cancer. It might be better to screen for targets that more generally regulate synaptic plasticity. Ketamine is a drug that does this, and there is huge interest in ketamine” in depression, Dr. Russo said.

Experts Weigh In

Commenting on the findings for Medscape Medical News, David Dietz, PhD, assistant professor of pharmacology and toxicology, State University of New York at Buffalo, who was not involved in the research, said the study “is exquisitely well done. The researchers did an excellent job of translating their findings in the rodent model to the human condition.”

Maria V. Tejada-Simon, PhD, who also was not involved in this research but who has studied Rac1, noted that her group has been “highlighting the importance of Rac1 in the brain in general, and in psychiatric diseases in particular, for a while now. Therefore, I am not surprised that Rac1 has been found to be also associated to stress disorders and depression.”

“Mood disorders have been linked to changes in synaptic structure, and it is certain that small GTPases such as Rac1 have a tremendous role as modulators of these processes. However, we need to understand that alterations in Rac1 signaling are not likely to be the primary defect in mood disorders.

“Thus, targeting Rac1 to moderate clinical symptoms (while there is potential for a translational approach there) has to be done very carefully, given the broad role of Rac1 in many cellular functions involving the actin cytoskeleton,” said Dr. Tejada-Simon, assistant professor of pharmacology and adjunct assistant professor of biology and psychology at University of Houston College of Pharmacy in Texas.

“The highlight of this research is in identifying a possible mechanism by which we can study pathways that are involved in remodeling of the brain; we might be able to find something a little bit more specific down the line,” Dr. Dietz said.

He noted that Rac1 has also been linked to addiction.

“It’s well known that there is comorbidity between depression and addiction, that one may lead to the other, so there seems to be something fundamentally related between Rac1 and these 2 psychiatric disease states.”

The research was supported by the National Institute of Mental Health and the Johnson and Johnson International Mental Health Research Organization Rising Star Award (presented to Dr. Russo). The other authors, Dr. Tejada-Simon, and Dr. Dietz have disclosed no relevant financial relationships.

Nat Med. Published online February 17, 2013. Abstract

A clinical decision rule performed well, but CT within 6 hours missed 20% of cases.

 

Depending on the number of slices, computed tomography (CT) of the brain misses up to 7% of subarachnoid hemorrhages (SAH). But a recent study suggested that if CT was performed within 6 hours of headache onset, the miss rate was zero (JW Emerg Med Aug 5 2011). Another study provided a decision rule that excluded all cases of SAH (JW Gen Med Nov 9 2010). Now, researchers retrospectively applied the decision rule and assessed the sensitivity of CT within 6 hours in adults with SAH who presented to 21 Kaiser Permanente emergency departments (EDs) in California from 2000 to 2011. All patients had normal neurological exams, initial negative CT results, and >5 red blood cells/µL of cerebrospinal fluid (CSF). SAH was diagnosed on the basis of presence of CSF xanthochromia or angiography findings of cerebral aneurysm or arteriovenous malformation.

The clinical decision rule would exclude SAH if none of the following are present: age ≥40, complaint of neck pain or stiffness, witnessed loss of consciousness, or onset of headache with exertion. Of 55 patients with SAH, 2.9% were missed by the clinical decision rule. Negative CT results were obtained within 6 hours of headache onset in 11 patients, for a CT miss rate of 20%; some of the false-negative CT results were obtained with modern, 64-slice scanners.

Comment: Sadly, this study shows that neither history and physical examination nor CT can rule out SAH. The authors suggest that combining this clinical decision rule and CT could allow us to forego lumbar puncture — if a miss rate of 1 in 500 is tolerable — but this requires further study. For now, we should continue to recommend lumbar puncture when ruling out SAH in a patient with a negative CT result.

— Daniel J. Pallin, MD, MPH

Published in Journal Watch Emergency Medicine February 15, 2013

CITATION(S):

Mark DG et al. Nontraumatic subarachnoid hemorrhage in the setting of negative cranial computed tomography results: External validation of a clinical and imaging prediction rule. Ann Emerg Med 2012 Oct 1; [e-pub ahead of print]. (http://dx.doi.org/10.1016/j.annemergmed.2012.09.003)

http://www.nejm.org/doi/full/10.1056/NEJMoa1213701?query=featured_home

Até o momento o tratamento endovascular no geral não é superior ao tratamento intravenoso.

The results of this trial in patients with acute ischemic stroke indicate that endovascular therapy is not superior to standard treatment with intravenous t-PA.