No description available.

Altersassoziiert entwickeln Hunde eine Erkrankung, die in vielen Aspekten der Alzheimer-Krankheit des Menschen ähnelt. Das canine kognitive Dysfunktionssyndrom äußert sich klinisch u.a. durch Desorientierung in vertrauter Umgebung, Vergessen von Kommandos und einen gestörten Schlaf-Wach-Rhythmus. Aus der Literatur ist bekannt, dass in den Gehirnen von alten Hunden regelmäßig Aβ- und selten Tauablagerungen zu beobachten sind. Allerdings erfolgte bisher kein Nachweis des hochgradig zytotoxischen und modifizierten pE3Aβ. Auch Veränderungen der mikroglialen Morphologie wurden bisher nicht beschrieben. Insgesamt lagen in dieser Studie 24 euthanasierte Rasse- und Mischlingshunde verschiedenen Alters vor. Fünf dieser Tiere besaßen ein durchschnittliches Alter von 2,1 Jahren und dienten als Kontrollgruppe. Die anderen 19 Hunde waren 8 bis 19 Jahre alt und wurden entsprechend ihrer Größe und des Gewichts in die drei Kategorien kleine (≤ 10 kg), mittelgroße (10 – 25 kg) und große Hunde (> 25 kg) unterteilt. Die Gehirne wurden aus den Schädeln präpariert und in 4 % Paraformaldehyd fixiert. Anschließend erfolgte die Präparation des frontalen und entorhinalen Kortex sowie der Hippokampusformation, die in 30%iger Saccharoselösung vitrifiziert und mittels Methylbutan bei -80 °C eingefroren wurden. Von den Regionen wurden Kryoschnitte mit einer Dicke von 40 µm angefertigt und diese anhand immunhistologischer Färbungen auf das Vorhandensein von Ablagerungen, bestehend aus den Amyloidsubtypen Aβ8-17 und pE3Aβ, sowie aus hyperphosphorylierten Tau, untersucht. Die Morphologie und das Aktivitätsstadium der Mikroglia wurden mit Antikörpern gegen Iba1 und TAL.1B5 analysiert. Zusätzlich erfolgte eine Untersuchung anhand des Filament Tracer. Stereologische Analysemethoden wurden zur Quantifizierung der Aβ-Ablagerungen und der Mikroglia angewandt. Disseminierte Plaques fanden sich bereits ab 9 Jahren. In den untersuchten Gehirnregionen von alten Hunden zeichnete sich ein progressiver Verlauf der Ablagerungen ab. Da insbesondere kleinere Hunde ein höheres Alter erreichten als mittelgroße und große Hunde konnten in dieser Kategorie vermehrt Plaques beobachtet werden. Den alten Tieren gemein war, dass in den untersuchten Gehirnregionen pE3Aβ-Plaques häufiger vorlagen als Plaques, die aus Aβ8-17 bestanden. Kleinere parenchymale und meningeale Gefäße des frontalen Kortex schienen besonders anfällig gegenüber pE3Aβ-Ablagerungen zu sein. Im entorhinalen Kortex von kleinen Hunden war die Menge an gefäßassoziierten Aβ8-17- und pE3Aβ-Ablagerungen annähernd gleich. Bei mittelgroßen und großen Hunden dominierte im entorhinalen Kortex und ventralen Hippokampus die Anzahl an gefäßassoziierten Aβ8-17-Ablagerungen. Bei kleinen Hunden existierten im ventralen Hippokampus signifikant mehr gefäßassoziierte Aβ8-17- als pE3Aβ-Ablagerungen. Hyperphosphoryliertes Tau fand sich in der Hippokampusformation von drei Hunden im Alter von 11 bzw. 15 Jahren. Der Schweregrad war unterschiedlich ausgeprägt, sodass nur ein Hund eine hochgradige Pathologie mit NFTs und neuritischen Plaques aufwies. Einhergehend mit dem Alter und einer assoziierten Proteinpathologie fanden sich Veränderungen der mikroglialen Morphologie. Neben ramifizierten Mikroglia lagen in den untersuchten Gehirnregionen aktivierte Mikroglia vor. Einige Mikroglia wiesen Zeichen einer Seneszenz auf und waren insbesondere in den Gehirnen von Hunden mit einer hochgradigen Aβ- bzw. Tau-Pathologie vorhanden. Zusammenfassend ist festzustellen, dass mit dieser Studie eine nähere Charakterisierung des caninen kognitiven Dysfunktionssyndroms erfolgte. Die Befunde sind von hoher translationaler Bedeutung und fördern die Etablierung des Hundes als natürliches Modelltier zur Untersuchung von Alterungsprozessen des Gehirns und für die Erforschung des initialen Stadiums der Alzheimer-Krankheit. / Dogs develop an age-associated cognitive dysfunction syndrome with several aspects resembling Alzheimer\\\'s disease. Affected animals show signs of dis-orientation in their familiar surroundings, dementia, and a disturbed circadian rhythm. The underlying neurodegenerative disease is associated with patho-logic changes in the brain including regularly deposition of β-pleated amyloid and rarely hyperphosphorylated tau accumulation. However, there have been no reports of the highly cytotoxic and modified pE3Aβ in the canine brain. Equally, altered microglial morphology has not been documented so far. For this study 24 euthanized thoroughbred dogs and mongrels of different ages were available. Five of these animals had an average age of 2.1 years and served as control group. The remaining 19 dogs were 8 to 19 years old. Accor-ding to their height and weight these dogs were divided into 3 different categories including small (≤ 10 kg), medium (11 - 25 kg) and large dogs (> 25 kg). Brains were dissected from the skulls and fixed in 4 % paraformaldehyde. Afterwards the frontal and entorhinal cortex as well as the hippocampal for-mation were isolated, vitrificated in 30 % sucrose solution and frozen to -80 °C by methylbutane. These regions were sliced into 40 µm thick sections and subsequently stained by immunohistology in order to detect deposits of Aβ8-17, pE3Aβ and hyperphosphorylated tau, respectively. Antibodies against Iba1 and TAL.1B5 were used to analyze microglial morphology and activation status. Additionally further investigations were made with the Filament Tracer of Imaris software. Stereological analysis methods served for the quantification of Aβ depositions and microglia. Disseminated Aβ plaques were detected in dogs from 9 years on. Within the examined brain regions of elderly dogs a progressive course of Aβ depositions was observed. Especially small dogs had a longer lifespan than medium and large dogs with the result that more plaques were deposited in the brains of small dogs. Elderly dogs had in common that pE3Aβ-plaques where more often located in the examined brain regions than plaques containing Aβ8-17. Minor parenchymal and meningeal vessels seemed to be susceptible especially to pE3Aβ depositions. The amount of vessel-associated Aβ8-17 and pE3Aβ in the entorhinal cortex of small dogs was almost equal. Within the entorhinal cortex of medium and large dogs the amount of vessel-associated Aβ8-17 predominated. The ventral hippocampus of small dogs showed significantly more vessel-associated Aβ8-17 than pE3Aβ depositions. Hyperphosphorylated tau was present in the hippocampal formations of 3 dogs with an age of 11 and 15 years, respectively. The degree of severity varied with the result that only one dog showed a high-grade pathology with development of NFTs and neuritic plaques. Accompanied by age and associated protein pathology altered microglial morphology was detected. Alongside with ramified microglia, activated cells were identified in the examined brain regions. Several microglia showed signs of senescence and were present in the brains of dogs with severe Aβ and tau pathology. Summarizing, this study facilitated a further characterization of the canine cognitive dysfunction syndrome. The results are of highly translational importance and encourage the establishment of the dog as a natural animal model for studying age-associated processes and the initial stage of Alzheimer’s disease.

Conselho Nacional de Desenvolvimento Científico e Tecnológico / Alzheimer s disease (AD) is biochemically characterized by the occurrence of extracellular deposits of amyloid beta peptide (Aβ) and intracellular deposits of the hyperphosphorylated tau protein, which are causally related to the pathological hallmarks senile plaques and neurofibrillary tangles. Monoamine oxidase B (MAO-B) activity, an enzyme involved in the oxidation of biogenic monoamines, is particularly high around the senile plaques and increased in AD patients in middle to late clinical stages of the disease. Selegiline, a selective and irreversible MAO-B inhibitor, improves learning and memory in AD patients. Notwithstanding, its mechanism of action is still not completely known. The current study aimed to investigate whether selegiline improves the Aβ25-35 induced cognitive deficit in the object recognition task in mice. In addition, we investigated whether selegiline alters MAO-B and MAO-A activities in the hippocampus, perirhinal and remaining cerebral cortices of Aβ25-35-injected mice. Acute (1 and 10 mg/kg, p.o., immediately post-training) and subchronic (10 mg/kg, p.o., seven days after Aβ25-35 injection and immediately post-training) administration of selegiline reversed the cognitive impairment induced by Aβ25-35 (3 nmol, i.c.v.). Acute administration of selegiline (1 mg/kg, p.o.) in combination with Aβ25-35 (3 nmol) decreased MAO-B activity in the perirhinal and remaining cerebral cortices. Acute administration of selegiline (10 mg/kg, p.o.) decreased MAO-B activity in hippocampus, perirhinal and remaining cerebral cortices, regardless of Aβ25-35 or Aβ35-25 treatment. MAO-A activity was not altered by selegiline or Aβ25-35. In summary, the current findings further support a role for MAO-B in the cognitive deficits observed in AD. / A doença de Alzheimer (DA) é bioquimicamente caracterizada por depósitos extracelulares de peptídeo beta amiloide (Aβ) e de proteína tau hiperfosforilada, que são causalmente relacionadas com as características patológicas, placas neuríticas e emaranhados neurofibrilares. A atividade da monoamina oxidase B (MAO-B), uma enzima envolvida na oxidação de monoaminas biogênicas, é particularmente elevada ao redor das placas senis e aumenta nos pacientes com DA em estágios clínicos de moderado a grave. A selegilina, um inibidor seletivo e irreversível da MAO-B, é relatada por melhorar a memória e o aprendizado em pacientes com DA. Porém, seu mecanismo de ação ainda não é completamente conhecido. O presente estudo teve como objetivo investigar se a selegilina melhora o déficit cognitivo induzido por Aβ25-35. na tarefa de reconhecimento de objetos em camundongos. Além disso, investigou-se a atividade da MAO-A e da MAO-B no hipocampo, no córtex cerebral e no córtex perirrinal de camundongos injetados com Aβ25-35 e com selegilina. Administração aguda (1 e 10 mg/kg, p.o., imediatamente pós-treino) e subcrônica (10 mg/kg, p.o., por sete dias depois da injeção do Aβ25-35 e imediatamente pós-treino) de selegilina preveniu o prejuízo da memória induzido pelo Aβ25-35 (3 nmol, icv). A administração aguda de selegilina (1 mg/kg, p.o.) em combinação com Aβ25-35 (3 nmol) diminuiu a atividade da MAO-B no córtex perirrinal e córtex cerebral. A administração aguda de selegilina (10 mg/kg, p.o.) diminuiu a atividade da MAO-B no hipocampo, no córtex cerebral e no córtex perirrinal independentemente da presença de Aβ25-35. A atividade da MAO-A não foi alterada pelo tratamento com selegilina ou Aβ25-35 em nenhuma das estruturas estudadas. Em resumo, os dados atuais suportam um papel adicional para a MAO-B no déficit cognitivo observado na DA.

Os objetivos deste trabalho são avaliar o papel da atenção na percepção de tempo em jovens, idosos e pacientes com a doença de Alzheimer (DA). Nosso trabalho experimental consiste em 4 experimentos. Os experimentos 1 e 2 avaliaram a percepção de tempo em jovens, empregando tarefas de reprodução e de discriminação de durações temporais, respectivamente. Os resultados mostram um efeito atencional nas durações curtas com menor d. Os experimentos 3 e 4 compararam a percepção de tempo entre jovens, idosos e pacientes com DA, empregando tarefas de reprodução e de discriminação de tempo, respectivamente. Os resultados mostram um pior desempenho de idosos e pacientes com DA em relação aos jovens, que parece corresponder a uma deficiência atencional. Concluímos que a modulação da atenção apresenta papel fundamental e crítico na percepção de tempo e os déficits na percepção de tempo em idosos e em pacientes com DA parecem estar associada a uma menor quantidade de recursos atencionais ou a uma dificuldade de focar a atenção. / Our work focused on the attentional modulation of the perception of time. Additionally, other objective was to study the effect of aging and Alzheimers disease (DA) on temporal perception. We have performed four experiments. The first and the second experiments evaluated time perception in young volunteers, by means of the reproduction and discrimination of time intervals, respectively. The results showed an effect of attention on short durations, confirmed by d. The third and fourth experiments had the objective to compare time perception among young volunteers, elderly and DA patients, utilizing reproduction and discrimination of time intervals, respectively. Our findings showed a worse performance in both elderly volunteers and patients with DA in comparison with the group of young volunteers. Our conclusion is that time perception deficits in elderly and patients with DA are associated either to lesser attentional resources or to an increased difficulty in focusing attention on the target, which is more evident in patients suffering of DA.

Submitted by Luciana Sebin (lusebin@ufscar.br) on 2016-09-28T18:55:34Z No. of bitstreams: 2 TesePRMM.pdf: 7211801 bytes, checksum: 788705ca3b95b2f530d64b669f066f88 (MD5) TesePRMM.pdf: 7211801 bytes, checksum: 788705ca3b95b2f530d64b669f066f88 (MD5) / Approved for entry into archive by Marina Freitas (marinapf@ufscar.br) on 2016-10-10T18:35:31Z (GMT) No. of bitstreams: 2 TesePRMM.pdf: 7211801 bytes, checksum: 788705ca3b95b2f530d64b669f066f88 (MD5) TesePRMM.pdf: 7211801 bytes, checksum: 788705ca3b95b2f530d64b669f066f88 (MD5) / Approved for entry into archive by Marina Freitas (marinapf@ufscar.br) on 2016-10-10T18:35:43Z (GMT) No. of bitstreams: 2 TesePRMM.pdf: 7211801 bytes, checksum: 788705ca3b95b2f530d64b669f066f88 (MD5) TesePRMM.pdf: 7211801 bytes, checksum: 788705ca3b95b2f530d64b669f066f88 (MD5) / Made available in DSpace on 2016-10-10T18:35:56Z (GMT). No. of bitstreams: 2 TesePRMM.pdf: 7211801 bytes, checksum: 788705ca3b95b2f530d64b669f066f88 (MD5) TesePRMM.pdf: 7211801 bytes, checksum: 788705ca3b95b2f530d64b669f066f88 (MD5) Previous issue date: 2016-03-11 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / ADAM10 is an-secretase that cleaves APP in the non-amyloidogenic pathway, thereby inhibiting -amyloid peptide (A ) production in Alzheimer´s disease (AD). Studies have shown decreased ADAM10 platelet levels in AD patients as well as the deregulation of microRNAs (miRNAs) related to molecules involved in the pathophysiology of this disease. The objective was to verify and compare ADAM10 gene expression and micro-RNAs (miRNAs) between AD patients and controls without cognitive impairment. It is a comparative study, based on the assumptions of quantitative research. Biological samples were collected, analyzed and stored in a biorepository. The ADAM10 gene expression in whole blood was studied in 47 AD, 32 healthy controls and 21 mild cognitive impairment (MCI) subjects by RT-qPCR techniques and analyzed by relative expression by 2- Ct. For miRNAs analyses, using MegaplexTM and MirWalk 2.0 database, were analyzed by RT-qPCR ~700 miRNAs in total blood and 21 miRNAs of them were validated in a sample of 21 AD subjects and 17 healthy controls. Statistical association tests, regression and diagnostic accuracy were performed. No significant differences in ADAM10 gene expression were observed between AD and control groups. Therefore, the decrease of ADAM10 protein in platelets of AD patients was not caused by a reduction in mRNA encoding for ADAM10. Mir-144-5p, miR-374 and miR-221 were downregulated in AD subjects, with moderate accuracy diagnosis. However, the association of selected miRNAs expression and Mini Mental State Examination (MMSE) was significantly better as a diagnostic tool compared to their expression separately. The validated miRNAs are involved in the regulation of pathways related to neurodegenerative diseases (beta-amyloid cascade, ubiquitination, transcriptional regulator, synaptic transmission, vesicle trafficking). Specifically, miR-144-5p, miR-374 and miR-221 are relevant for AD, as regulators of APP, BACE1 and ADAM10 translation. To the best of our knowledge, this is the first study to demonstrate a downregulation of these specific miRNAs in total blood of Alzheimer’s disease patients, compared to healthy cognitive controls. These findings are in agreement with AD protein outcomes and place the miRNAs evaluated as potential biomarkers that can be used to improve AD diagnosis. / ADAM10 é uma -secretase que cliva a APP através do caminho não amiloidogênico, inibindo desta forma a produção do peptídeo -amiloide (A ) na doença de Alzheimer (DA). Estudos apresentam a diminuição plaquetária da proteína ADAM10 em idosos com DA, assim como a desregulação de microRNAs (miRNAs) relacionados com moléculas envolvidas com a fisiopatologia desta doença. O objetivo geral foi verificar e comparar a expressão gênica da ADAM10 e de miRNAs entre idosos com DA e controles sem alterações cognitivas. Trata-se de um estudo de comparação, baseado nos pressupostos da pesquisa quantitativa. Amostras biológicas foram coletadas, analisadas e armazenadas em um biorrepositório. A expressão gênica da ADAM10 em sangue total foi estudada em 47 sujeitos com DA, 32 controles saudáveis e 21 sujeitos com transtorno neurocognitivo leve (TNCL), através de técnicas de RT-qPCR e analisada pela expressão relativa por 2- Ct. Para análises dos miRNAs, utilizando Megaplex e a base de dados MiRWalk 2.0, foram analisados por RTqPCR ~700 miRNAs no sangue total e 21 deles foram validados em uma amostra de 21 sujeitos com DA e 17 controles. Testes estatísticos de associação, regressão e acurácia diagnóstica foram realizados. Não foi observada diferença significante na expressão gênica da ADAM10 entre sujeitos com DA e controles. Assim, a diminuição dos níveis proteicos da ADAM10 plaquetária em pacientes com DA não foi devido a redução do mRNA codificante para ADAM10. Mir-144-5p, miR-374 e miR-221 estavam menos expressos em indivíduos com DA, com moderada acurácia diagnóstica. Entretanto, a associação da expressão dos miRNAs selecionados com o Mini Exame do Estado Mental (MEEM) foi significativamente melhor como uma ferramenta de diagnóstico em comparação com as análises individuais. Os miRNAs validados estão envolvidos na regulação de vias relacionadas a doenças neurodegenerativas (cascata beta-amiloide, ubiquitinação, reguladores de transcrição, transmissão sináptica, tráfego de vesículas). Especificamente, o miR-144-5p, miR-374 e miR- 221 são relevantes para a DA, como reguladores da tradução da APP, BACE1 e da ADAM10. Segundo nosso conhecimento, este é o primeiro estudo a demonstrar a expressão reduzida desses miRNAs no sangue total de pacientes com DA, em comparação com controles cognitivamente saudáveis. Estes resultados estão de acordo com os resultados proteicos da DA e destacam os miRNAs avaliados como potenciais biomarcadores que podem ser utilizados para o aperfeiçoamento do diagnóstico da DA.

Made available in DSpace on 2016-06-02T19:46:01Z (GMT). No. of bitstreams: 1 1935.pdf: 3958213 bytes, checksum: a0c4b39152b1526967689c4de8929368 (MD5) Previous issue date: 2008-02-25 / Financiadora de Estudos e Projetos / Population aging is an increasing reality in developing countries. As a result, in the past decades the dementia has become one of the major problems of public health, affecting at least 5% of the population over the age of 65 years. Alzheimer s disease (AD), which is one form of dementia, is related to memory impairment, loss of capacity to learn new skills and forgetfulness of those skills previously mastered. The purpose of this study was twofold: (1) to investigate whether or not people with AD can learn new conditional discriminations; (2) to verify the extent to which learning of and memory for the stimuli decrease in elderly people without AD. The matching-to-sample (MTS) has been used to assist different populations with special needs in the acquisition of discriminative skills that cannot be learned through conventional teaching methods. The participants in this study were six elderly individuals with AD (two in the initial phase and four in the moderate phase), eight elderly individuals without any form of dementia, and seven young adults aged between 18 and 38 years. The elderly with AD failed to learn conditional discriminations with arbitrary stimuli, but they did learn identity conditional discriminations and simple discriminations. The typically developing elderly participants learned the conditional discriminations and did form equivalence classes; however, they required more training than the younger participants. This study allowed the identification of the process by which every participant learned the relationships, as well as the analysis of the differences between ages and health conditions of the elderly. The systematic teaching of new discriminations could be a useful strategy to maintain the cognitive skills along the aging process. / O envelhecimento populacional é uma realidade crescente nos países em desenvolvimento e nas últimas décadas as demências passaram a constituir um sério problema de saúde pública, acometendo, no mínimo, 5% da população com idade superior a 65 anos. A doença de Alzheimer (DA) é uma demência relativa ao déficit da memória, perda da capacidade de aprender novas habilidades e esquecimento de habilidades previamente aprendidas. O presente projeto teve por objetivo investigar se o doente de Alzheimer poderia aprender novas discriminações e o quanto a aprendizagem e a lembrança dos estímulos decaem na velhice, sem a presença de DA. O emparelhamento com o modelo é um procedimento de ensino de discriminações condicionais que vem sendo utilizado com diferentes populações com necessidades especiais, auxiliando na aquisição de habilidades e repertórios não aprendidos pelos métodos convencionais de ensino a partir do manejo de conseqüências diferenciais para as respostas. Participaram da pesquisa seis idosos diagnosticados com doença de Alzheimer (dois na fase inicial da doença e quatro em fase moderada), oito idosos sem acometimento de qualquer tipo de demência, e sete adultos jovens, com idades de 18 a 38 anos. O procedimento de emparelhamento era simultâneo ou com atraso, para todos os participantes, para problemas discriminativos diferentes. A ordem das condições foi balanceada entre os problemas. Os idosos com Alzheimer não aprenderam discriminações condicionais com estímulos arbitrários; entretanto, aprenderam discriminações condicionais de identidade e discriminações simples. Os idosos com desenvolvimento típico aprenderam as relações condicionais e formaram classes, porém, com maior dificuldade que os jovens. O trabalho permitiu identificar o processo de aprendizagem das relações para cada participante, bem como analisar as diferenças entre cada faixa etária e condições de saúde na velhice. O ensino sistemático de novas discriminações pode ser uma estratégia para manter a cognição ao longo do envelhecimento.

The current trend of general mature of population brings the broad range of serious consequences, mainly the increase of incidence and prevalence of diseases, which occur much often by the older people. From the medical and socio-economical point of view, the most serious disease is the aphreina, because the prevalence of this disease by the people older 60 years together with increasing age has the exponential character. The deterioration of the patient` s condition is also a big stress for the family. It is very difficult to accept the fact of the gross degeneration of closed person` s personality and don{\crq}t change the attitude to him. The patient is still physically present, but his mentality has been changed, he lost his personality. ``Is he, but it isn{\crq}t him anymore.{\crqq} The technology of controlled conversation, casuistic and secondary analysis of data has been used for the qualitative research. The controlled conversations was done at Senior hospice Maj. The group was consist of 5 family members of patient, who has the Alzheimer disease, 5 nurses from the department with special regime and 3 social workers. The secondary analysis of data was realized on the basis of statistics, which has been already published at the Grade theses called: ``The problems family nurses caring for the patients with Alzheimer disease.{\crqq} For this analysis, the 15 informants have been used. Within the stated aim {--} to chart the activities of self-helping groups - I have used the data published at Annual report of Czech Alzheimer` s company from 2005. I have also made uncontrolled conversation with coordinator of self-helping group at Ceske Budejovice. The results of the research showed that the biggest problem with the devotion about the patient is the psychical stress. The rest, relaxation, fun, etc. could help to feel better. If these principals are followed, the most of the problems will never occur. The help of further people is necessary to fulfill these points. The research refer to problem of nonavailability of self-helping groups, family nurses caring for the patients with Alzheimer disease within the specific region of Czech Republic and also refer to low awareness about their existence and their activities. I hope that my thesis help to home-nurses to predate the problems, which have been mentioned here {mainly the mental ones}, and also helps to existing self-helping groups.

Septinas constituem uma família de proteínas de ligação a GTP que foram inicialmente identificadas em levedura Saccharomyces cerevisiae, mas também estão presentes em outros eucariotos com exceção de plantas. Septinas são purificadas de leveduras, Drosophila e cérebros de mamíferos na forma de filamentos, porém o mecanismo através do qual acorre a formação destes filamentos ainda não é muito bem compreendido. Septinas são constituídas de três regiões principais: um N-terminal variável, um domínio central GTPase altamente conservado e um domínio coiled-coil C-terminal. O gene SEPT4 foi identificado por M. Tanaka e colaboradores a partir do cDNA de cérebro humano e apresentou duas distintas transcrições: Bradeiona ? e ?. Interessantemente, além de cérebro e coração, as proteínas Bradeiona Α e Β. são detectadas somente em câncer do cólon, reto, próstata e melanoma maligno. Neste trabalho, o gene da proteína Bradeiona Β foi subclonado em um vetor de expressão bacteriano, produzido em E. coli e purificado com sucesso. O espectro de dicroísmo circular (CD) mostrou o perfil característico de proteínas com hélices a na estrutura secundária. Resultados de cromatografia de exclusão molecular (SEC) e espalhamento dinâmico de luz (DLS) indicam que a septina Bradeina foi produzida na forma de um estável oligômero com características monodispersivas, que foi subseqüentemente cristalizado em PEG6000. A atividade GTPase da Bradeiona Β foi comprovada através da técnica de eletroforese capilar (CE), mostrando-se absolutamente dependente de íons Mg2+. Inibição da atividade GTPase foi verificada em altas concentrações de Mg2+ (maiores que 5 mM). Com a finalidade de caracterizar os domínios preditos da Bradeiona Β (Fragmento Conservado e domínio GTPase), essas regiões foram previamente definidas, expressas em E. cozi e purificadas com sucesso. Resultados de CD, SEC, espectroscopia de fluorescência e NMR-600MHz indicam que o FC foi produzido na forma de um estável monômero com pouca estrutura secundária regular. Resultados de DLS e CD indicam que a fusão 6xHis-DGTPase foi produzida na forma de um oligômero com a presença de hélices a na estrutura secundária. A fusão 6xHis-DGTPase mostrou-se instável a altas concentrações na ausência de imidazol. A atividade GTPase da fusão GST+DGTPase foi comprovada, similarmente a Bradeiona , através da técnica de CE. Novamente, verificou-se dependência de íons Mg2+ (para a atividade catalítica) e inibição em altas concentrações de Mg2+. A fusão GST+DGTPase também foi capaz de hidrolisar ATP. Espera-se que as informações relatadas neste estudo proporcionem um alicerce para estudos estruturais/funcionais futuros das proteínas Bradeiona Α e Βoutras septinas. / Septins form a class of eukaryoyic guanine nucleotide-binding proteins that were first identified in budding yeast. Septins purified from yeast, Drosophila and mammalian brain form filaments, however the mechanism by which the filaments assemble is unclear. Septins have a highly conserved structure, which includes a central GTP-binding domain, a variable N-terminal region, and most septins also contain a coiled coil domain at the Cterminus. Bradeion p is one of the splice variants of the human septin gene, SEPT4, recently isolated by expression screening of an adult human brain cDNA library. The Bradeion gene resides at 17q23, and has been shown to present specific expression in both human colorectal cancer, urologic cancers and malignant melanoma. In order to characterize the GTPase activity of Bradeion Β , the protein was successfully expressed in E. coli and purified. The recombinant protein was characterized by circular dichroism (CD), dynamic light scattering (DLS) and a novel non-radioactive enzyme assay, which utilizes capillary electrophoresis (EC) to monitor GTP hydrolysis. The CD spectrum exhibited the typical shape characteristic of the presence of helical elements of secondary structure and the DLS pattern was indicative of a monodisperse solution, which was readily crystallized in the presence of PEG6000. GTP hydrolysis was shown to be Mg2+ dependent within the low millimolar range but at 5 mM was inhibitory. In order to characterize the predicted domains of Bradeion Β, these defined regions were successfully expressed in E. cozi and purified. The CD spectrum of CF exhibited the shape typically found for non-regular structure. The results of fluorescence spectroscopy, gel filtration (SEC) and NMR-600MHz also corroborate with the CD results indicating an irregular structure. The fusion protein 6xHis-DGTPase exhibited a CD spectrum with the typical shape characteristic of the presence of helical elements but was show to be instable at high concentrations in the absence of imidazole. To characterize the GTPase activity of the fusion protein GST+DGTPase, the CE technique was used to monitor GTP hydrolysis. Analysis by CE showed that GST+DGTPase was functional, since both GTP and ATP hydrolysis was observed in a Mg2+ dependent manner. This work provides novel approaches, which should aid in the fbture study of the structure and fùnction of Bradeion Α e Β, others septins and related GTPases.

Aumento das concentrações de cortisol em idosos com Doença de Alzheimer (DA) tem sido relatado como resultado da ausência de inibição do eixo hipotálamo-pituitária-adrenal (HPA) em decorrência da disfunção hipocampal observada nestes indivíduos. Além disso, associação entre concentrações elevadas de cortisol e comprometimento da memória tem sido evidenciada em idosos saudáveis. Entretanto, pouco se sabe a respeito do envolvimento do estresse nas concentrações de cortisol, no desempenho cognitivo e nas estratégias de coping tanto em idosos saudáveis como naqueles com comprometimento cognitivo leve (CCL) e DA. Assim, este estudo teve o objetivo de investigar a associação entre intensidade de estresse, concentrações de cortisol, estratégias de coping e desempenho cognitivo em idosos saudáveis, com CCL e DA. Para isto, concentrações basais de cortisol salivar foram analisadas em uma amostra composta por 40 idosos saudáveis, 31 idosos com CCL amnéstico e 40 indivíduos com DA leve. O desempenho cognitivo global foi avaliado a partir do mini-exame do estado mental (MEEM), o desempenho da memória através da Bateria Breve de Avaliação Cognitiva (BBAC) e pelo teste de extensão de dígitos na ordem inversa. A intensidade do estresse foi avaliada a partir da Lista de Sintomas de Stress (LSS) e as estratégias de coping através da Escala de Coping de Jalowiec (ECJ). Desta forma, foram observadas concentrações de cortisol marginalmente mais elevadas nos idosos com DA do que nos idosos saudáveis (p = 0.062). Além disso, verificou-se associação positiva entre cortisol e desempenho da memória nos idosos saudáveis (p = 0.008), enquanto correlação negativa entre estas variáveis foi observada no grupo CCL (p = 0.011). Não foi verificada associação significativa nos idosos com DA (p > 0.05). Ademais, observou-se correlação positiva entre as concentrações de cortisol e a intensidade de estresse somente nos idosos com CCL (p = 0.056). Com relação às estratégias de enfrentamento, observou-se que os idosos com CCL que elegem o coping focado no problema apresentam intensidade de estresse menor que os idosos que utilizam o coping focado na emoção (p = 0.048). Estes resultados sugerem que a associação entre concentrações de cortisol, desempenho da memória, intensidade de estresse e coping varia em função da presença ou ausência de comprometimento cognitivo e da percepção das limitações cognitivas / Increased cortisol levels have been reported in elderly with Alzheimers disease (AD) as a result of the lack in the hypothalamic-pituitary-adrenal (HPA) axis inhibition as a function of hipocampal atrophy observed in those subjects. Moreover, association between high cortisol levels and memory impairment has been demonstrated in healthy elderly subjects. However, little is known about the stress involvement in the cortisol levels, in the cognitive performance and in the coping strategies in both elderly with mild cognitive impairment (MCI) and with AD. Thus, this study aimed to investigate the association between stress intensity, cortisol levels, coping strategies and cognitive performance in healthy elderly, subjects with CCL and with DA. Basal salivary cortisol was measured in a sample composed of 40 healthy elderly subjects, 31 individuals with amnestic MCI and 40 subjects with mild AD. Global cognitive performance was evaluated with the Mini Mental State Exam (MMSE) and memory performance was assessed with the Brief Cognitive Screening Battery (BCSB) and the backward digit span test. Stress intensity was evaluated with the Stress Symptoms List (SSL) and coping strategies with the Jalowiec Coping Scale (JCS). Marginally higher cortisol levels were observed in the subjects with AD group in comparison with healthy elderly (p = 0.062). Furthermore, positive association between cortisol levels and memory performance was observed in the healthy elderly (p = 0.008) while negative correlation was observed between these variables in the MCI group (p = 0.011). No significant association was exhibited in the AD group (p > 0.05). Moreover, positive correlation between cortisol levels and stress intensity was observed only in the MCI group (p = 0.056). Regarding the coping strategies, it was observed that those MCI subjects who elect problem focused coping exhibit higher stress intensity than those MCI who use emotion focused coping (p = 0.048). These results suggest the association between cortisol levels, memory performance, stress intensity and coping strategies may vary as a function of the presence or absence of cognitive impairment and as a function of the cognitive deficits awareness

Introdução: O envelhecimento populacional traz desafios, como os prejuízos de funcionalidade em tarefas rotineiras, decorrentes de condições crônicas de saúde, como a demência da doença de Alzheimer (DA). Para elaborar propostas de intervenção adequadas ao portador de DA e a sua família, a funcionalidade deve ser avaliada. O Routine Task Inventory - Expanded (RTI-E) é uma avaliação que permite avaliar o desempenho em ABVD, AIVD, Comunicação e Preparo para o Trabalho a partir da perspectiva do paciente, do cuidador e do terapeuta. Objetivo: Traduzir, adaptar transculturalmente, medir a fidedignidade e a validade da versão brasileira do RTI-E para avaliar a funcionalidade em idosos com DA. Métodos: Realizou-se a tradução e adaptação transcultural do instrumento. Utilizou-se o coeficiente ? de Chronbach para avaliar a consistência interna. A fidedignidade entre avaliadores do RTI-E foi obtida por CCI. A validade de conteúdo foi obtida por validade convergente (correlacionando a avaliações cognitivas e funcionais) e divergente (correlação com HAM-D). A validade de critério foi obtida por validade concorrente. Resultados: Foram avaliados 85 sujeitos, divididos em 42 sujeitos grupo DA (CDR=1 ou 2) e 43 sujeitos grupo controle (CDR=0) e seus pares. Obteve-se a tradução e adaptação transcultural do RTI-E, aprovada pela autora. O RTI-E demonstrou consistência interna elevada em cada escala analisada, sendo o valor mais alto em AIVD obtida por relato do cuidador (?=0,966) e alta fidedignidade entre avaliadores. O instrumento mostrou validade convergente em relação a medidas cognitivas, sendo a maior correlação encontrada em AIVD, relato cuidador (r=0,912, comparado a CAMCOG e r=0,911, comparado a MEEM). Em relação a medidas funcionais, a correlação foi muito forte em relato do cuidador (AIVD X Lawton [r= 0,917]) e em observação do terapeuta (AIVD X DAFS-Br [r=0,911]). As escalas por autorrelato mostram correlações fracas ou insignificantes. O RTI-E mostrou-se capaz de discriminar sujeitos com DA e sem DA, calculando-se áreas sob a curva ROC. Obteve-se pontos de corte variando conforme cada escala. A maior precisão (98,82%) foi encontrada em AIVD, relato cuidador, com sensibilidade 100% e especificidade 97,67%, para ponto de corte 5,26, porém, observando-se todos os valores, nota-se que o RTI-E mostra-se um instrumento mais específico do que sensível. Conclusão: Obteve-se uma versão final adaptada ao nosso meio, aprovada pela autora. O instrumento mostrou-se válido e fidedigno para avaliar a funcionalidade de idosos com DA, oferencendo informações importantes para planejamento de intervenções / Background: Population aging presents challenges, such as functional impairment in routine tasks, due to chronic health conditions, like dementia of Alzheimer\'s disease (AD). In order to design appropriate intervention programs for the AD and his / her family, functionality should be evaluated. The Routine Task Inventory - Expanded (RTI-E) is an assessment that allows evaluating the performance in AVD, IADL, Communication and Working Readiness from the perspective of the patient, the caregiver and the therapist. Objective: To translate, cross-culturally adapt, measure the reliability and validity of the Brazilian version of RTI-E to evaluate the functionality in the elderly with AD dementia compared to the elderly without cognitive impairment. Methods: Translation and cross-cultural adaptation of the instrument was carried out, aiming to maintain semantic and conceptual equivalence to the original. The Chronbach\'s ? coefficient was used to evaluate the internal consistency and interrater reliability was obtained by ICC. Content validity was obtained by convergent validity (correlation with cognitive and functional assessments) and divergent (correlation with HAM-D). Criterion validity was obtained by concurrent validity. Results: There were 85 subjects, divided into 42 subjects, AD group (CDR = 1 or 2) and 43 control group subjects (CDR = 0) and their peers. Translated and cross-culturally adapted version of the RTI-E, approved by the author, was achieved. The RTI-E demonstrated high internal consistency in each analyzed scale, being the highest value in AIVD obtained by a caregiver report (alpha = 0.966) and high interrater reliability. The instrument showed convergent validity in relation to cognitive measures, the highest correlation was found in AIVD, caregiver report (r = 0.912, compared to CAMCOG and r = 0.911, compared to MMSE). About functional measures, the correlation was very strong in caregiver\'s report (AIVD X Lawton [r = 0.917]) and in therapist\'s observation (AIVD X DAFS-Br [r = 0.911]). Self-report scales showed weak or insignificant correlations. RTI-E was able to discriminate between subjects with AD and controls. Cut-off points were obtained varying according to each scale. The highest precision (98.82%) was found in AIVD, a caregiver report, with 100% sensitivity and 97.67% specificity, for cut-off point 5,26. However, observing all values, RTI-E shows to be more specific than sensitive. Conclusion: A final version adapted to our culture, approved by the author was obtained. The instrument was valid and reliable to evaluate the functionality of the elderly with AD, offering important information for planning interventions