Size effects on silver nanoparticles` properties

In this work a systematic study of the dependence of the structural, electronic, and vibrational properties on nanoparticle size is performed. Based on our total energy calculations we identified three characteristic regimes associated with the nanoparticle`s dimensions: (i) below 1.5 nm (100 atoms) where remarkable molecular aspects are observed; (ii) between 1.5 and 2.0 nm (100 and 300 atoms) where the molecular behavior is influenced by the inner core crystal properties; and (iii) above 2.0 nm (more than 300 atoms) where the crystal properties are preponderant. In all considered regimes the nanoparticle`s surface modulates its properties. This modulation decreases with the increasing of the nanoparticle`s size.

Creatine transporter expression in skeletal muscle

Creatine is an important molecule involved in providing energy to the body. Its major stores are in skeletal muscle. The creatine transporter protein (CreaT) mRNA is believed to be responsible for the uptake of the majority of creatine in skeletal muscle. This thesis examined factors that might have affected the expression of the creatine transporter in skeletal muscle.

Effects of vegetarianism and exercise on muscle creatine loading and gene expression

The results of this thesis indicate that vegetarianism and prior exercise can increase skeletal muscle creatine loading. The mechanisms by which these phenomena occur remain unknown but may be related to changes in the gene expression of a cellular pump within the muscle known as the "creatine transporter".

Bovine lactoferrin : potential antioxidant effector molecule in colon carcinoma

This research generated important insight into the antioxidant capacity and effector molecule capability of bovine lactoferrin in both its Apo- (iron free) and metal saturated forms within the gastrointestinal system, giving rise to bovine lactoferrin's potential at regulating oxidative stress associated signalling molecules within colon carcinoma.

Advances in the treatment of malignant gliomas

Local control with surgery, radiation, and temozolomide chemotherapy remain the pillars of treatment for high-grade gliomas. Novel therapeutic strategies, including a variety of antiangiogenic agents, are under investigation. One of these agents, bevacizumab, was recently given accelerated approval by the US Food and Drug Administration as a single agent for recurrent glioblastoma. Recent trial results are generating important clinical questions regarding which patients to treat and when, and how best to monitor response. Encouraging results of recent studies are driving willingness to undertake aggressive treatment and to improve outcomes in this population. In this era, better understanding of biology, molecular aspects of cancer, and clinical trial methodology are crucial for clinicians. This review focuses on recent advances in the treatment malignant gliomas, especially antiangiogenic therapy.

Insights into the Specificity of Thioredoxin Reductase-Thioredoxin Interactions. A Structural and Functional Investigation of the Yeast Thioredoxin System

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Enriquecimento ambiental reduz as alterações astrocitárias e a progressão da doença prion em modelo murino: ensaios morfométricos, estereológicos e comportamentais

Já está bem estabelecido que um estilo de vida sedentário é fator de risco para uma série de doenças crônicas, dentre elas a doença de Alzheimer. A neuropatologia da doença de Alzheimer é caracterizada por depósitos amilóides, perda neuronal, gliose reativa e vacuolização da neurópila. A doença príon tem sido amplamente utilizada como modelo experimental para estudar aspectos celulares e moleculares da neurodegeneração crônica em muito semelhante àquela descrita na doença de Alzheimer. O ambiente empobrecido das gaiolas padrão de laboratório tem sido usado para mimetizar um estilo de vida sedentário enquanto que o ambiente enriquecido tem sido empregado para mimetizar um estilo de vida ativo. Para testar a hipótese de que o ambiente enriquecido pode contribuir para desacelerar o curso temporal da neurodegeneração crônica associada à doença príon em modelo murino induzimos a doença príon em vinte camundongos fêmeas da variedade suíça albina que tinham sido alojadas aos seis meses de idade em ambiente enriquecido (EE) ou em ambiente padrão (SE) durante cinco meses. Após esse peródo foram realizadas cirurgias para injeção estereotáxica intracerebral bilateral de homogendao de cérebro de camundongo normal (NBH, n=10) ou de camundongo com sinais clínicos de doença príon terminal (ME7, n=10). Os animais foram devolvidos as suas gaiolas e condições de alojamento originais formando os seguintes grupos experimentais: NBH SE=5, NBH EE=5, ME7 SE=5, ME7 EE=5. Após três semanas foi iniciado teste semanal empregando o burrowing, uma tarefa sensível ao dano hipocampal e 18 semanas após as inoculações realizou-se os testes de memória de reconhecimento de objetos. Encerrados os testes sacrificou-se os animais realizando-se o processamento histológico do tecido nervoso visando a imunomarcação astrocítica das áreas de interesse. A redução progressiva da atividade de burrowing teve início na décima terceira semana pós injeção no grupo ME7 SE e somente na décima quinta semana no grupo ME7 EE. A habilidade de reconhecer o objeto deslocado no teste de memória espacial foi comprometida no grupo ME7 SE, mas se manteve normal nos demais grupos experimentais. O teste de discriminação entre o objeto novo e o familiar não revelou alterações. As análises quantitativas sem viés dos astrócitos imunomarcados para proteína fibrilar ácida (GFAP) foram realizadas no stratum radiatum de CA3 e na camada polimórfica do giro denteado dorsal. As estimativas estereológicas do número total de astrócitos e do volume do corpo celular revelaram que em CA3 somente ocorre hipertrofia dos corpos celulares em animais dos grupos ME7 SE e ME7 EE em relação aos respectivos controles, sendo o volume médio dos corpos celulares do grupo ME7 EE menor que aquele do grupo ME7 SE. Na camada polimórfica houve significativo aumento do número de astrócitos no grupo ME7 SE em relação ao NBH SE e do grupo NBH EE em relação ao NBH SE. O volume do corpo celular também foi significativamente maior nos grupos ME7 em relação aos respectivos controles dos grupos NBH. As análises morfométricas tridimensionais revelaram importante aumento de volume e área de superfície dos segmentos das árvores astrocíticas nos grupos doentes em comparação aos controles. O enriquecimento ambiental reduziu o aumento de volume dos ramos observado no grupo ME7 e aumentou o número de intersecções dos ramos distais no grupo NBH EE em relação ao NBH SE e nos ramos proximais no grupo ME7 EE em relação ao ME7 SE. O emprego da análise de cluster e discriminante permitiu a identificação dos parâmetros morfométricos que mais contribuíram para a distinção entre os grupos. Para testar a hipótese de existirem subfamílias de astrócitos morfologicamente distintos dentro de cada grupo experimental, foi realizada análise de conglomerados que resultou na formação de duas famílias distintas no grupo NBH SE, três famílias nos grupos NBH EE e ME7 EE e quatro famílias no grupo ME7 SE. As bases celulares e moleculares que conduzem a formação de novas famílias de astrócitos e a neuroproteção associada ao ambiente enriquecido que diminui a velocidade de progressão da doença permanecem por serem investigadas.

Luteinizing Hormone Receptor (LHR): basic concepts in cattle and other mammals. a review

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

O conceito de organismo em uma abordagem hierárquica e sistêmica da biologia

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Aspectos estruturais e moleculares do músculo cardíaco durante a transição entre a disfunção e a insuficiência cardiaca

Pós-graduação em Biologia Geral e Aplicada - IBB

Aspectos estruturais e moleculares do músculo cardíaco durante a transição entre a disfunção e a insuficiência cardiaca

Pós-graduação em Biologia Geral e Aplicada - IBB

Febrile response induced by cecal ligation and puncture (CLP) in rats: involvement of prostaglandin E-2 and cytokines

The purpose of the present study was to better understand the events involved in the febrile response induced by cecal ligation and puncture (CLP), a complex infectious process. To this end, we conducted in vivo experiments in rats examining (1) fever development, (2) bacterial number in the infection focus and in blood, (3) peripheral and hypothalamic synthesis of cytokines, (4) hypothalamic and cerebrospinal fluid (CSF) synthesis of prostaglandin E-2 (PGE(2)), (5) the effect of anti-IL-6 antibody on fever, and (6) the effect of celecoxib on fever and hypothalamic synthesis of PGE(2) after CLP induction. We found that CLP promotes fever and animal death depending on the number of punctures. The peak of CLP-induced fever overlapped with the maximal increase in the number of bacteria in the infectious focus and blood, which occurred at 6 and 12 h. The peak of the febrile response also coincided with increased amounts of interleukin (IL)-1 beta, IL-6 and IL-10 in the peritoneal exudate and serum; IL-6 in the hypothalamus and PGE(2) in the CSF and predominantly in the hypothalamus. Moreover, intracerebroventricularly injected anti-IL-6 antibody reduced the febrile response while celecoxib reduced the fever and PGE(2) amount in the hypothalamus induced by CLP. Tumor necrosis factor (TNF)-alpha peaked at 3 h at all sites studied. Conversely, IL-10 concentration decreased in the hypothalamus. These findings show that the peak of CLP-induced fever is accompanied by an increase of bacteria in peritoneal fluid (local infection) and blood; local synthesis of pyrogenic (IL-1 beta, IL-6) and antipyretic (IL-10) cytokines and central production of IL-6 and PGE(2), suggesting that these last are the central mediators of this response.

Clinical implication of 14-3-3 epsilon expression in gastric cancer

AIM: To evaluate for the first time the protein and mRNA expression of 14-3-3 epsilon in gastric carcinogenesis. METHODS: 14-3-3 epsilon protein expression was determined by western blotting, and mRNA expression was examined by real-time quantitative RT-PCR in gastric tumors and their matched non-neoplastic gastric tissue samples. RESULTS: Authors observed a significant reduction of 14-3-3 epsilon protein expression in gastric cancer (GC) samples compared to their matched non-neoplastic tissue, Reduced levels of 14-3-3 epsilon were also associated with diffuse-type GC and early-onset of this pathology. Our data suggest that reduced 14-3-3 epsilon may have a role in gastric carcinogenesis process. CONCLUSION: Our results reveal that the reduced 14-3-3 epsilon expression in GC and investigation of 14-3-3 epsilon interaction partners may help to elucidate the carcinogenesis process. (C) 2012 Baishideng. All rights reserved.

Different approaches, one target: understanding cellular mechanisms of Parkinson's and Alzheimer's diseases

Neurodegenerative disorders are undoubtedly an increasing problem in the health sciences, given the increase of life expectancy and occasional vicious life style. Despite the fact that the mechanisms of such diseases are far from being completely understood, a large number of studies; that derive from both the basic science and clinical approaches have contributed substantial data in that direction. In this review, it is discussed several frontiers of basic research on Parkinson's and Alzheimer's diseases, in which research groups from three departments of the Institute of Biomedical Sciences of the University of Sao Paulo have been involved in a multidisciplinary effort. The main focus of the review involves the animal models that have been developed to study cellular and molecular aspects of those neurodegenerative diseases, including oxidative stress, insulin signaling and proteomic analyses, among others. We anticipate that this review will help the group determine future directions of joint research in the field and, more importantly, set the level of cooperation we plan to develop in collaboration with colleagues of the Nucleus for Applied Neuroscience Research that are mostly involved with clinical research in the same field.