998 resultados para Célula TCD4
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A radioproteo dos pacientes submetidos a exames radiogrficos est diretamente ligada qualidade e repetio das radiografias realizadas. Esta dissertao apresentada sob a forma de trs artigos. O artigo I avaliou a qualidade de 300 radiografias panormicas enviadas a clnicas de ortodontia. As radiografias foram classificadas como excelentes (no se observam erros), aceitveis para diagnstico (observam-se erros, contudo os mesmos no impedem o diagnstico) e inaceitveis (imagem sem valor diagnstico). Um total de 16,33% das radiografias foi considerado excelente, 78,66% aceitveis para o diagnstico e 5% inaceitveis. Encontrou-se uma mdia de 1.54 erros por radiografia, sendo os mais freqentemente encontrados a falta de contato da lngua com o palato (21%), aparecimento de imagens fantasma (19,66%), mento inclinado para cima (15,66%), paciente frente do plano de foco (13,33%), cabea girada (13,33%), imagens com alta densidade (10,33%) e com baixa densidade (8,66%). Concluiu-se que os padres de qualidade da amostra esto de acordo com o preconizado em Guidelines on Radiology Standards for Primary Dental Care, segundo os quais se admite at 10% de imagens inaceitveis. Contudo, cabe salientar que no se conhece o ndice de repeties nas clnicas onde as radiografias da amostra foram obtidas e, tendo passado por um controle de qualidade prvio, todas as imagens deveriam ser classificadas como excelentes ou aceitveis. O artigo II avaliou a freqncia dos erros que levaram repetio de radiografias panormicas realizadas no Servio de Radiologia da FO-UFRS. O livro de registros do Servio mostrou um total de 3815 radiografias panormicas realizadas no perodo de junho de 2002 a junho de 2005. No mesmo perodo o Servio apresentou 330 radiografias panormicas repetidas, resultando em ndice de repetio de 8,65% dos exames. Os erros mais freqentemente encontrados foram: paciente posicionado frente do plano de foco (25,15%); cabea girada para direita ou esquerda (24,84%); cabea inclinada para frente (21,21%); paciente posicionado atrs do plano de foco (20,30%); imagem com a alta densidade (19,69%); imagem com baixa densidade (17,27%); imagem com baixo contraste (16,96%); imagem com alto contraste (12,72%); cabea inclinada para direita ou esquerda (12,42%); corte do cndilo na radiografia (11,21); corte do mento na radiografia (8,48%); ausncia de contato da lngua com o palato (7,27%); paciente se moveu durante a exposio (4,94%); cabea inclinada para trs (2,72%) e aparecimento de imagem fantasma (2,12%). Encontrou-se uma mdia de 2,07 erros por radiografia. Conclui-se que os erros mais freqentemente cometidos foram classificados como erros de posicionamento do paciente e que o Servio de Radiologia da FO-UFRGS apresenta um ndice de repetio de radiografias panormicas satisfatrio, estando de acordo com os padres de qualidade estabelecidos pelo Guidelines on Radiology Standards for Primary Dental Care. O artigo III teve por objetivo verificar o efeito da radiao emitida em radiografias panormicas sobre as células da borda lateral direita da lngua, atravs da avaliao das alteraes nucleares, antes e depois da exposio aos raios X. A amostra foi constituda de 42 indivduos adultos jovens do gnero masculino, sendo 22 deles pertencentes ao grupo que realizou uma radiografia panormica (grupo I) e os outros 20 pacientes pertencentes ao grupo II, que realizou duas radiografias panormicas. O exame citopatolgico das células esfoliadas da mucosa da lngua foi realizado antes da incidncia radiogrfica e 10 dias aps. As células foram obtidas atravs da raspagem e as lminas foram coradas pela tcnica de Feulgen. Para observao das alteraes citopatolgicas foram analisadas 2.000 células em cada lmina e quantificados os microncleos, buds, broken eggs, cariorrexes e células binucleadas. As lminas foram analisadas por um nico observador. Constatou-se que existe diferena significativa (p=0,01) para as variveis broken egg, bud, cariorrexe e célula binucleada antes e depois da exposio radiao ionizante. Na comparao entre os grupos, verificou-se que as variveis cariorrexe e célula binucleada apresentaram diferena significativa (p=0,01), ambas com valores superiores para o grupo II.
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Plantas da famlia Guttiferae apresentam diversas atividades biolgicas sendo Hypericum o gnero mais importante devido s atividades antidepressiva, antibacteriana e antiviral de algumas espcies. Hypericum connatum, utilizado no sul do Brasil para o tratamento de feridas de boca, demonstrou atividade contra o lentivrus, responsvel pela imunodeficincia felina. Objetivo: isolar e identificar as substncias majoritrias de H. connatum e testar a atividade de extratos obtidos das partes areas e razes e das substncias isoladas frente a duas cepas do herpesvrus simples tipo 1 (HSV-1). Mtodo: foram obtidos fraes nhexano, diclorometano e metanol e extratos bruto, aquosos a diferentes temperaturas e hidro-etanlico das partes areas e razes. As fraes n-hexano e metanlica das partes areas foram submetidas coluna cromatogrfica para o isolamento de substncias. Os extratos e substncias isoladas foram testados frente ao HSV-1, cepas KOS e ATCC-VR733. Determinou-se a concentrao mxima no txica (CMNT) célula e a concentrao que provoca alterao morfolgica em 50% das células (CC50) pela tcnica da alterao morfolgica celular, utilizando-se células VERO, linhagem ATCC CCL-81. A avaliao da atividade antiviral foi realizada em placas de microtitulao e medida pela inibio do efeito citoptico (ECP) provocado pelo vrus. Resultados e Concluses: da frao n-hexano foi isolado hiperbrasilol B, da frao metanlica foram isolados amentoflavona, hiperosdeo e guaijaveriana, alm de um flavonol de estrutura ainda no definida (HCN3). A frao n-hexano e o extrato bruto das razes inibiram o ECP das cepas KOS e ATCC-VR733. Os demais extratos testados no apresentaram atividade antiviral. Dentre as substncias analisadas, hiperbrasilol B, amentoflavona e HCN3 foram ativos frente s duas cepas. Os flavonides hiperosdeo e guaijaverina no apresentaram atividade anti-HSV-1.
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O pantoprazol (PAN) um inibidor da bomba de prtons clinicamente empregado para o tratamento de lcera gstrica e refluxo gastro-esofgico. Estudos relacionados estabilidade fsico-qumica mostraram que a degradao do PAN est diretamente relacionada com a acidez do meio, determinando a necessidade de administr-lo em uma forma gastrorresistente. Desse modo, este trabalho props-se a desenvolver micropartculas base de polmero gastrorresistente (Eudragit S100), polmero de baixa permeabilidade (Eudragit RS30D) ou de blenda polimrica (Eudragit S100/ Eudragit RS30D), contendo PAN pela tcnica de spraydrying . O estudo de dissoluo in vitro utilizando célula de fluxo demonstrou que o PAN foi liberado das micropartculas em 120 minutos, seguindo cintica de primeira ordem, de acordo com o modelo monoexponencial. A avaliao da gastrorresistncia in vitro em célula de fluxo e em dissolutor evidenciou que as formulaes de micropartculas base de Eudragit S100 e da blenda (Eudragit S100/ Eudragit RS30D), garantiram adequada proteo ao frmaco em ambiente cido. Estudos in vivo confirmaram esses resultados, pois possibilitaram a constatao da proteo do frmaco pelas micropartculas durante a passagem pelo estmago, o que possibilitou absoro entrica do PAN em quantidade adequada para exercer atividade farmacolgica. Por fim, a investigao ex vivo da permeao do PAN carreado por micropartculas no epitlio intestinal mostrou que estes sistemas foram capazes de garantir a absoro da totalidade do frmaco carreado, constatando-se ainda que este processo ocorreu segundo o modelo monoexponencial.
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Apresenta a definio e descrio de células procariticas e eucariticas com o auxlio de figuras ilustrativas. Inicialmente detalha-se a célula procaritica e suas estruturas: parede celular, membrana celular, citoplasma, ribossomos, estruturas externas, regio nuclear, plasmdeo, endsporo, morfologia celular e diviso celular. A seguir apresenta-se a célula eucaritica e suas estruturas: organelas, retculo endoplasmtico, ribossomos, lisossomos, ncleo celular, mitocndrias, cloroplasto e complexo de Golgi. No decorrer da descrio enfatizam-se as semelhanas e diferenas entre as células procariticas e eucariticas, apresenta-se a Teoria endossimbitica e a rvore filogentica (Bacteria, Archaea e Eucarya).
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Apresenta a descrio de tcnicas de colorao para preparao de amostra de material biolgico para ser observada ao microscpio ptico, com destaque para a colorao diferencial de Gram. Todas as etapas do procedimento so reproduzidas detalhadamente: desde os cuidados para a fixao dos microrganismos nas lminas, a preparao do esfregao a partir de cultura crescida em meio lquido e em meio slido at a tcnica de colorao de Gram propriamente dita. Aps a descrio dos procedimentos apresentam-se exemplos de morfologia e colorao e a descrio detalhada do que ocorre com a célula durante cada etapa do processo de colorao.
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Parte 1: Introduo s planilhas eletrnicas Parte 2: O ambiente de trabalho do programa BrOffice.org Calc Parte 3: Primeiros passos Parte 4: Trabalhando com vetores e matrizes Parte 5: Construindo grficos Parte 6: Resolvendo problemas Parte 07: Travando uma célula na planilha
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Leachates are effluent produced by decomposition of solid waste, they have complex composition and can be highly toxic. Therefore such percolated liquid should be collected and treated properly to avoid environmental contamination of soil and of water bodies. The objective of this study was to evaluate the toxicity through ecotoxicological tests with Ceriodaphnia dubia (Cladocera - Crustacea) of percolated liquids generated in two different systems of municipal solid waste (MSW) disposal in the city of Natal/ RN: A Sanitary Landfill in the Metropolitan Region of Natal/ RN, and in a dump off area. Furthermore, it was evaluated the possible contamination of the underground water of the dump off area. Two monthly samples were taken at four points between the months of May/2009 and January/2010. The Point "A" corresponds to the end of the pond leachate treatment in ASRMN; The Point "B" corresponds to a containment pond at the dump. The Point "C" is an area near one of the cells of the dump off area where the leachate outcrops; The Point "D" stands for an underground water well at the area. The last point, called "E" was sampled only once and corresponds to the slurry produced by temporary accumulation of solid waste in the open area of the dump. The ecotoxicological tests, acute and chronic, followed the ABNT 13373/2005 rules, with some modifications. The samples were characterized by measuring the pH number, the dissolved oxygen (DO), the salinity, BOD5, COD, Cd, Cu, Pb, Cr, Fe, Mg, Ni, and Zn. At Point A, the average number of EC50-48h ranged between 1.0% and 2.77% (v/v), showing a high toxicity of the leachate to C.dubia in all months. To this point, positive correlations were found between the EC50- 48 with precipitation. Negative correlations were found between the EC50- 48h with salinity. At point B there was no response of the acute exposure of organisms to the test samples. At point C the EC50-48h ranged from 17.68% to 35.36% in just two months of the five ones analyzed, not correlated meaning. Point D, the EC50-48h level ranged between 12.31% and 71.27%, showed a negative correlation with, only, precipitation. Although it was observed toxicity of underground water in the Landfill Area, there was no evidence of water contamination by leachate, however, due to the toxic character of this water, additional tests should be conducted to confirm the quality of water that is used for human supply. At point E there was no acute toxicity. These results support the dangers of inappropriate disposal of MSW to water bodies due to the high toxicity of the leachate produced highlighting the necessity of places of safe confinement and a treatment system more effective to it
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The present study examines the chemical composition and their effects on free radicals, inflammation, angiogenesis, coagulation, VEGF effects and cellular proliferation of a polysaccharides from alga Sargassum vulgare. The sulfated polysaccharide was extracted from brown seaweed by proteolysis with enzymes maxataze. The presence of proteins and sugars were observed in crude polysaccharides. Fractionation of this crude extract was made with growing concentration of acetone (0.3-1.5 v) and produced four groups of polysaccharides. Anionic polysaccharides from brown seaweed Sargassum vulgare, SV1and PSV1 were fractionated (SV1) and purified (PSV1), and displayed with high total sugars and sulfate content and very low level of protein. This fucan SV1 contains low levels of protein and high carbohydrate and sulfate content. This polysaccharides prolonged activated partial thromboplastin time (aPTT) at 50 μg (>240 s). SV1 was found to have no effect on prothrombin time (PT), corresponding to the extrinsic pathway of coagulation. SV1 exhibits high antithrombotic action in vivo, with a concentration ten times higher than heparin. Polysaccharides from S. vulgare promoted direct inhibition enzymatic activity of thrombin and stimulated enzymatic activity of FXa. SV1 showed optimal inhibitory activity of thrombin (50.20.28%) at a concentration of 25 μg/mL. Its antioxidant action on scavenging radicals by DPPH was (22%), indicating the polymer has no cytotoxic action (hemolytic) on ABO and Rh blood types in different erythrocyte groups and displays strong anti-inflammatory action on all concentrations tested in the carrageenan-induced paw edema model, demonstrated by reduced edema and cellular infiltration. Angiogenesis is a dynamic process of proliferation and differentiation. It requires endothelial proliferation, migration, and tube formation. In this context, endothelial cells are a preferred target for several studies and therapies. The antiangiogenic efficacy of polysaccharides was examined in vivo in the chick chorioallantoic membrane (CAM) model by using fertilized eggs. Decreases in the density of the capillaries were assessed and scored. The results showed that SV1 and PSV1 have an inhibitory effect on angiogenesis. These results were also confirmed by inhibition tubulogenesis in rabbit aorta endothelial cell (RAEC) in matrigel. These compounds were assessed in Apoptosis assay (Annexin V - FITC / PI) and cell viability by MTT assay of RAEC. These polysaccharides do not affect the viability and do not have apoptotic or necrotic action. RAEC cell when incubated with SV1 and PSV1showed inhibition of VEGF secretion, observed when compounds were incubated at 25, 50 and 100 μg/μL. The VEGF secretion with the RAEC cell line for 24 h, was more effective for PSV1 at 50 μg/μL(71.4%) than SV1 100 μg/μL (75.9%). SV1 and PSV1 had an antiproliferative action (47%) against tumor cell line HeLa. Our results indicate that these sulfated polysaccharides have antiangiogenic and antitumoral actions
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The plants are often exposed to variations in environmental conditions that may trigger metabolic disturbances leading to a consequent loss in productivity of crops. These stressful conditions usually induce an accumulation of reactive oxygen species (ROS) in the cell, a condition known how oxidative stress. Among these species, hydrogen peroxide (H2O2) is an important molecule involved in numerous signaling mechanisms. The present study aimed to understand the relationship between the different enzymatic mechanisms of elimination of H2O2 by catalase (CAT) and ascorbate peroxidase (APX) in leaf tissues of seedlings of the species Vigna unguiculata L. Walp, under conditions of oxidative stress induced by application of CAT inhibitor, 3-amino-1,2,4-triazole (3-AT), and H2O2 itself on the roots. Three experiments were conducted. The first experiment was performed applying the compound 3-AT (5 mM) during the time (hours). In the second experiment, seedlings were exposed to different concentrations of H2O2 (2.5, 5.0, 7.5, 10 mM) for 48 h. The third strategy included the pre-treatment with H2O2 (2.5 mM) for 24 h, followed by subsequent treatment with the inhibitor 3-AT and recovery control condition. Treatment with 3-AT causes a strong inhibition of CAT activity in leaf tissues accompanied by an increase of activity of APX. However a decrease in oxidative damage to lipids is not observed as indicated by TBARS. It was observed that activity of APX is directly linked to the content of peroxide. Inductions in the activities of CAT and APX were observed mainly in the seedlings treated with 2.5 mM H2O2. This can be associated with a decrease in oxidative damage to lipids. In contrast, one same tendency was not observed in treatments with higher concentrations of this ROS. These results suggest that the concentration of 2.5 mM H2O2 can induce responses antioxidants later in seedling cowpea. This concentration when applied as pre-treatment for 24 h promoted an induction systems removers CAT and APX, both in activity and in terms of gene expression. However this increment was not observed in the recovered plants and the plants subsequently subjected to 3-AT. Additionally, the pretreatment was not sufficient to attenuate the inhibition of CAT activity and oxidative damage to lipids caused by the subsequent application of this inhibitor. The results showed that the application of 3-AT and H2O2 in the root systems of seedlings of cowpea promote changes in the parameters analyzed in leaf tissues that indicate a direct response to the presence of these factors or systemic signaling mecanisms. H2O2 appears to activate the responses of two antioxidant systems in this study thar does not promote greater protection in case of additional treatment with 3-AT. This demonstrates the importance of the CAT system. In this work, complete results indicate that there is a difference between the signaling and the effects caused by exposure to H2O2 and by treatment with 3-AT
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Gene therapy is one of the major challenges of the post-genomic research and it is based on the transfer of genetic material into a cell, tissue or organ in order to cure or improve the patient s clinical status. In general, gene therapy consists in the insertion of functional genes aiming substitute, complement or inhibit defective genes. The achievement of a foreigner DNA expression into a population of cells requires its transfer to the target. Therefore, a key issue is to create systems, vectors, able to transfer and protect the DNA until it reaches the target. The disadvantages related to the use of viral vectors have encouraged efforts to develop emulsions as non-viral vectors. In fact, they are easy to produce, present suitable stability and enable transfection. The aim of this work was to evaluate two different non-viral vectors, cationic liposomes and nanoemulsions, and the possibility of their use in gene therapy. For the two systems, cationic lipids and helper lipids were used. Nanoemulsions were prepared using sonication method and were composed of Captex 355; Tween 80; Spam 80; cationic lipid, Stearylamine (SA) or 1,2-dioleoyl-3-trimethylammoniumpropane (DOTAP) and water (Milli-Q). These systems were characterized by average droplet size, Polidispersion Index (PI) and Zeta Potential. The stability of the systems; as well as the DNA compaction capacity; their cytotoxicity and the cytotoxicity of the isolated components; and their transfection capacity; were also evaluated. Liposomes were made by hydration film method and were composed of DOTAP; 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine (DOPE), containing or not Rhodaminephosphatidylethanolamine (PE- Rhodamine) and the conjugate Hyaluronic Acid DOPE (HA-DOPE). These systems were also characterized as nanoemulsions. Stability of the systems and the influence of time, size of plasmid and presence or absence of endotoxin in the formation of lipoplexes were also analyzed. Besides, the ophthalmic biodistribution of PE-Rhodamine containing liposomes was studied after intravitreal injection. The obtained results show that these systems are promising non-viral vector for further utilization in gene therapy and that this field seems to be very important in the clinical practice in this century. However, from the possibility to the practice, there is still a long way
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Despite advances in antibiotic therapy, bacterial meningitis (BM) remains with high mortality and morbidity rates in worldwide. One important mechanism associated to sequels during disease is the intense inflammatory response which promotes an oxidative burst and release of reactive oxygen species, consequently leading to cell death. Activation of DNA repair enzymes during oxidative stress has been demonstrated in several neurological disorders. APE1/Ref-1 is a multifunctional protein involved in DNA repair and plays a redox function on transcription factors such as NFkB and AP-1.The aim of this study was assess the role of APE1/Ref-1 on inflammatory response and the possibility of its modulation to reduce the sequels of the disease. Firstly it was performed an assay to measure cytokine in cerebrospinal fluid of patients with BM due to Streptococcus pneumoniae and Neisseriae meningitides. Further, a cellular model of inflammation was used to observe the effect of the inhibition of the endonuclease and redox activity of APE1/Ref-1 on cytokine levels. Additionally, APE1/Ref-1 expression in cortex and hippocampus of rat with MB after vitamin B6 treatment was evaluated. Altogether, results showed a similar profile of cytokines in the cerebrospinal fluid of patients from both pathogens, although IFNy showed higher expression in patients with BM caused by S. pneumoniae. On the other hand, inhibitors of APE1/Ref-1 reduced cytokine levels, mainly TNF-. Reduction of oxidative stress markers was also observed after introduction of inhibitors in the LPS-stimulated cell. In the animal model, BM increased the expression of the protein APE1/Ref-1, while vitamin B6 promoted reduction. Thereby, this data rise important factors to be considered in pathogenesis of BM, e.g., IFNy can be used as prognostic factor during corticosteroid therapy, APE1/Ref-1 can be an important target to modulate the level of inflammation and VIII oxidative stress, and vitamin B6 seems modulates several proteins related to cell death. So, this study highlights a new understanding on the role of APE1/Ref-1 on the inflammation and the oxidative stress during inflammation condition
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In vitro and in animal models, APE1, OGG1, and PARP-1 have been proposed as being involved with inflammatory response. In this work, we have investigated if the SNPs APE1 Asn148Glu, OGG1 Ser326Cys, and PARP-1 Val762Ala are associated to meningitis and also developed a system to enable the functional analysis of polymorphic proteins. Patients with bacterial meningitis (BM), aseptic meningitis (AM) and controls (non-infected) genotypes were investigated by PIRA-PCR or PCR-RFLP. DNA damages were detected in genomic DNA by Fpg treatment. IgG and IgA were measured from plasma and the cytokines and chemokines were measured from cerebrospinal fluid samples using Bio-Plex assays. The levels of NF-B and c-Jun were measured in CSF by dot blot assays. A significant (P<0.05) increase in the frequency of APE1 148Glu allele in BM and AM patients was observed. A significant increase in the genotypes Asn/Asn in control group and Asn/Glu in BM group was also found. For the SNP OGG1 Ser326Cys, the genotype Cys/Cys was more frequent (P<0.05) in BM group. The frequency of PARP-1 Val/Val genotype was higher in control group (P<0.05). The occurrence of combined SNPs increased significantly in BM patients, indicating that these SNPs may be associated to the disease. Increasing in sensitive sites to Fpg was observed in carriers of APE1 148Glu allele or OGG1 326Cys allele, suggesting that SNPs affect DNA repair activity. Alterations in IgG production were observed in the presence of SNPs APE1Asn148Glu, OGG1Ser326Cys or PARP-1Val762Ala. Reductions in the levels ofIL-6, IL-1Ra, MCP-1/CCL2and IL-8/CXCL8 were observed in the presence of APE1148Glu allele in BM patients, however no differences were observed in the levels of NF-B and c-Jun considering genotypes and analyzed groups. Using APE1 as model, a system to enable the analysis of cellular effects and functional characterization of polymorphic proteins was developed using strategies of cloning APE1 cDNA in pIRES2-EGFP vector, cellular transfection of the construction obtained, siRNA for endogenous APE1 and cellular cultures genotyping. In conclusion, we obtained evidences of an effect of SNPs in DNA repair genes on the regulation of immune response. This is a pioneering work in the field that shows association of BER variant enzymes with an infectious disease in human patients, suggesting that the SNPs analyzed may affect immune response and damage by oxidative stress level during brain infection. Considering these data, new approaches of functional characterization must be developed to better analysis and interactions of polymorphic proteins in response to this context
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Titanium is a biomaterial widely employed in biomedical applications (implants, prostheses, valves, stents). Several heat treatments are usually used in order to obtain physical properties required to different applications. This work studied the influence of the heat treatment on microstructure of commercial pure titanium, and their consequences in growth and proliferation of MC3T3-E1 cells. Discs of titanium were treated in different temperatures, and characterized by optical microscopy, image analysis, wettabillity, roughness, hardness and X-ray diffraction. After the heat treatment, significant modifications in these properties were observed. Pattern images of titanium, before and after the cell culture, were compared by overlapping to analyze the influence of microstructure in microstructure and preferences guidance cells. However, in general, titanium discs that showed a higher residual strength also presented an increase of cells numbers on surface
