657 resultados para Necrotic pulps
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In the present study, the effects of Polybia paulista venom (PPV) on renal and vascular tissues were investigated. Isolated kidneys perfused with PPV (1 and 3 mu g/mL) had increased perfusion pressure, renal vascular resistance, urinary flow, and glomerular filtration rate; and reduced sodium tubular transport. Histological evaluation demonstrated deposits of proteins in Bowman's space and tubular lumen, and focal areas of necrosis. The venom promoted a cytotoxic effect on Madin-Darby canine kidney (MDCK) cells. A significant increase in lactic dehydrogenase levels was observed in response to venom exposure. In isolated mesenteric vascular beds, pressure and vascular resistance augmented in a dose-dependent manner. PPV increased the contractility of aortic rings maintained under basal tension. This contractile response was inhibited when preparations were maintained in Ca2+-free medium. Likewise, verapamil, a voltage-gated calcium channel blocker, also inhibited the contractile response. In this study, phentolamine, a blocker of a-adrenergic receptor blocker, significantly reduced the contractile effect of PPV in the aortic ring. In conclusion, PPV produced nephrotoxicity, which suggests a direct effect on necrotic cellular death in renal tubule cells. The vascular contractile effect of PPV appears to involve calcium influx through voltage-gated calcium channels via adrenergic regulation.
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Las resinas compuestas y adhesivos dentales se utilizan ampliamente para la restauración de dientes con pulpas vitales. La preferencia en el uso de estas resinas compuestas podría estar atribuida a que son materiales con buenos resultados estéticos y se consideran materiales de restauración estables. Sin embargo se ha demostrado que son susceptibles a la degradación y liberación de la fracción de sus componentes y que cierta cantidad de los monómeros de su composición permanecen sin polimerizar por un largo periodo de tiempo, pudiendo estos filtrarse hacia el tejido pulpar y causar alteraciones de la actividad fisiológica de las células de la pulpa (DPCs) (1). Además, estudios in vitro han demostrado que los componentes de las resinas compuestas tienen potenciales tóxicos, generando respuestas inmediatas y a largo plazo luego de su aplicación. Identificar el potencial tóxico y deletéreo de los materiales de restauración sobre el tejido pulpar es de gran interés y relevancia clínica, por ello este estudio comprende en una revisión de la literatura acerca de la respuesta pulpar a los materiales de restauración tipo resina.
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Aim: To analyze the root canal organic tissue dissolution capacity promoted by irrigating solutions, with or without the use of different agitation techniques. Methods: Bovine pulp tissue fragments were initially weighed. The following irrigating solutions were tested: 2.5% sodium hypochlorite, 2% chlorhexidine digluconate solution, and distilled water. The irrigating protocols were: immersion, mechanical agitation with endodontic files, and ultrasonic or sonic systems (Endoactivactor® and Easy Clean®). At the end of the protocols, the pulps were weighed to determine their final weight. For comparison, the average percentage of tissue dissolution in relation to the groups was analyzed using the Kruskal-Wallis nonparametric test complemented by multiple comparisons test. The significance level was set at 5%. Results: Among the irrigation solutions, 2.5% sodium hypochlorite showed a higher dissolving power than 2% chlorhexidine digluconate and distilled water. Furthermore, ultrasonic and sonic systems were more effective irrigating protocols than immersion and mechanical agitation with endodontic files. Conclusions: The combination of sodium hypochlorite with an agitation system promotes a greater degree of tissue degradation.
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In this study, the effect of phospholipase A2 (PLA2) derived from Crotalus durissus collilineatus was evaluated in vitro and in vivo on experimental cutaneous leishmaniasis. The promastigote and amastigote forms treated with PLA2 presented increased growth rate. In vivo studies showed that PLA2-treated Leishmania (Leishmania) amazonensis promastigotes increased the size of lesions in BALB/c mice, and histopathological analysis showed numerous necrotic regions presenting a higher density of polymorphonuclear, mononuclear, and amastigote cells. Additionally, infected macrophages treated with PLA2 were able to generate prostaglandin E2 (PGE2). Cytokine quantification showed that the supernatant from infected macrophages presented moderate and high amounts of IL-2 and IL-10, respectively. However, in PLA2-treated infected macrophages, suppression of IL-2 levels occurred, but not of IL-10 levels. Observation also revealed that both the supernatant and lysate of L. (L.) amazonensis promastigotes exhibited PLA2 activity, which, in the presence of dexamethasone, showed no reduction in their activities; while glucocorticoid maintained the ability of promastigote forms to infect macrophages, which presented values similar to controls. In conclusion, the results indicate that PLA2 may be a progression factor for cutaneous leishmaniasis, since the PLA2 effect suppressed IL-2 levels and generated PGE2, an inflammatory lipid mediator.
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Purpose: To evaluate the anti-apoptotic effect of phyllanthin on alcohol-induced liver cell death in HepG2 cells alone and in co-culture with human monocytic (THP-1) differentiated macrophage cells. Methods: Cell viability was determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The cells were pretreated with 1, 5 and 10 μM phyllanthin for 24 h followed by 1300 mM alcohol for HepG2 cells and 2000 mM alcohol for the co-cultured cells. Thereafter, intracellular reactive oxygen species (ROS), mitochondrial membrane potential (MMP) changes, apoptotic cell death and caspase-3/7 activities were assessed. Results: Alcohol exposure significantly increased intracellular ROS generation (p < 0.001), decreased MMP changes (p < 0.001), increased the number of apoptotic and necrotic cells (p < 0.001) and also induced higher caspase-3/7 activity (p < 0.001) in the co-culture with THP-1 differentiated macrophage cells than in HepG2 cells alone. Pretreatment of HepG2 cells and co-cultured cells with phyllanthin for 24 h prior to alcohol exposure significantly decreased intracellular production of ROS (p < 0.001) and also increased the change in MMP (p < 0.001) as well as caused a decrease in the number of apoptotic and necrotic cells (p < 0.001), but inhibited caspase-3/7 activity (p < 0.001). Conclusion: The results indicate that phyllanthin treatment may have a significant therapeutic effect on alcohol-related liver diseases.
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BACKGROUND Most European birds of prey find themselves in a poor state of conservation, with electrocution as one of the most frequent causes of unnatural death. Since early detection of electrocution is difficult, treatment is usually implemented late, which reduces its effectiveness. By considering that electrocution reduces tissue temperature, it may be detectable by thermography, which would allow a more rapid identification. Three individuals from three endangered raptor species [Spanish imperial eagle (Aquila adalberti), Lammergeier (Gypaetus barbatus) and Osprey (Pandion haliaetus)] were studied thermographically from the time they were admitted to a rehabilitation centre to the time their clinical cases were resolved. CASES PRESENTATION The three raptors presented lesions lacking thermal bilateral symmetry and were consistent with electrocution of feet, wings and eyes, visible by thermography before than clinically; lesions were well-defined and showed a lower temperature than the surrounding tissue. Some lesions evolved thermally and clinically until the appearance of normal tissue recovered, while others evolved and became necrotic. A histopathological analysis of a damaged finger amputated off a Lammergeier, and the necropsy and histopathology examination of an osprey, confirmed the electrocution diagnosis. CONCLUSIONS These results suggest that thermography is effective and useful for the objective and early detection and monitoring of electrocuted birds, and that it may prove especially useful for examining live animals that require no amputation or cannot be subjected to invasive histopathology.
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Single stage and two-stage sodium sulfite cooking were carried out on either spruce, pine or pure pine heartwood chips to investigate the influence of several process parameters on the initial phase of such a cook down to about 60 % pulp yield. The cooking experiments were carried out in the laboratory with either a lab-prepared or a mill-prepared cooking acid and the temperature and time were varied. The influences of dissolved organic and inorganic components in the cooking liquor on the final pulp composition and on the extent of side reactions were investigated. Kinetic equations were developed and the activation energies for delignification and carbohydrate dissolution were calculated using the Arrhenius equation. A better understanding of the delignification mechanisms during bisulfite and acid sulfite cooking was obtained by analyzing the lignin carbohydrate complexes (LCC) present in the pulp when different cooking conditions were used. It was found that using a mill-prepared cooking acid beneficial effect with respect to side reactions, extractives removal and higher stability in pH during the cook were observed compared to a lab-prepared cooking acid. However, no significant difference in degrees of delignification or carbohydrate degradation was seen. The cellulose yield was not affected in the initial phase of the cook however; temperature had an influence on the rates of both delignification and hemicellulose removal. It was also found that the corresponding activation energies increased in the order: xylan, glucomannan, lignin and cellulose. The cooking temperature could thus be used to control the cook to a given carbohydrate composition in the final pulp. Lignin condensation reactions were observed during acid sulfite cooking, especially at higher temperatures. The LCC studies indicated the existence of covalent bonds between lignin and hemicellulose components with respect to xylan and glucomannan. LCC in native wood showed the presence of phenyl glycosides, ϒ-esters and α-ethers; whereas the α-ethers were affected during sulfite pulping. The existence of covalent bonds between lignin and wood polysaccharides might be the rate-limiting factor in sulfite pulping.
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Os fármacos anti-reabsorção óssea mais utilizados atualmente são os bifosfonatos que são medicamentos que inibem a actividade osteoclástica. O mecanismo de ação destes fármacos consiste na redução da reabsorção óssea pois inibem a apoptose dos osteoclastos e promovem a inibição da angiogénese. Estes fármacos são utilizados no tratamento de doenças como a osteoporose, hipercalcemia, doença de Paget e em pacientes oncológicos com metástases ósseas de tumores sólidos e mieloma múltiplo. Por outro lado, estes fármacos além de todos os benefícios que têm para os pacientes nestas condições, podem ter como complicação a osteonecrose dos maxilares (ONM). A ONM é uma complicação oral grave caracterizada, na maioria, por uma osteomielite inicial que normalmente evolui para uma exposição de osso necrosado acompanhada por dor na maxila ou na mandíbula. Nos doentes oncológicos têm sido diagnosticados vários casos de necrose óssea mais frequentemente na mandíbula. Esta patologia (ONM) apesar de ter baixa incidência e do seu aparecimento ser relativamente recente, levou à introdução de algumas recomendações internacionais para o uso de bifosfonatos, principalmente em pacientes oncológicos. Para a execução deste trabalho recorri a fontes de pesquisas como as bases de dados como a PubMed, B-On e, também ao Repositório Institucional da Universidade Fernando Pessoa das quais resultaram 198 artigos e duas monografias realizadas por exalunos da Universidade Fernando Pessoa. Com a realização deste trabalho foi possível esclarecer algumas dúvidas acerca dos efeitos que os fármacos anti-reabsorção óssea têm no organismo e mais especificamente na cavidade oral, de forma a estar consciente dos riscos que estes pacientes correm, caso lhes sejam realizados procedimentos como é o caso, das exodontias ou da colocação de implantes.
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A mandioca (Manihot esculenta Crantz) é considerada uma espécie relevante como fonte alimentícia para a população mundial, principalmente para os países subdesenvolvidos e emergentes. A mandioca é fornecedora de energia a partir do amido acumulado em suas raízes de reserva, mas é também importante destacar a presença dos carotenóides com atividade antioxidante. Nesse contexto, o presente trabalho teve como objetivo caracterizar, por meio de descritores morfológicos, agronômicos e bioquímicos, clones elite de mandioca de mesa de polpa aparelhada e rosada do programa de melhoramento genético de mandioca da Embrapa Cerrados. Foram caracterizados durante duas safras, 13 clones de mandioca de mesa com polpa amarelada e 8 clones com polpa rosada, em comparação com a variedade testemunha IAC 576-70 (BGMC 753). Para avaliar as características morfológicas foram obtidos 40 descritores qualitativos para cada clone. Tanto nos clones de polpas amarelada quanto naqueles de raízes de polpas rosada, houve diferenças morfológicas, demostrando que nenhum clone apresentou 100% de similaridade. O fator ano/safra não influenciou a expressão fenotípica dos caracteres aferidos. Com base no coeficiente cofenético, verificou-se elevado ajuste entre a representação gráfica via dendrograma de r = 0,80 nas raízes de polpa amarelada e r = 0,92 na rosada e a matriz de dissimilaridade genética. Entre os caracteres aferidos, os que apresentaram maior entropia nas raízes amarelada foram, a coloração da epiderme externa, forma do lóbulo central da folha e cor do córtex da raiz, ao passo que na rosada foi à cor do disco, forma do lóbulo central e cor do pecíolo. Foi realizada também a caracterização com base na altura da planta, altura da primeira ramificação, peso da parte aérea sem a cepa, produtividade em raízes, índices de amido nas raízes determinados por meio do método da balança hidrostática, tempo para a cocção e teor de ácido cianídrico nas raízes. Com base nos caracteres avaliados, os clones que se destacaram com polpa amarelada e rosada respectivamente, no caractere altura da primeira ramificação (273/08 e 259/08) e (390/08, 345/08 e a testemunha IAC 576-70), altura da planta (90/08, 272/08, 273/08, 497/08, 259/08 e 450/08) e (390/08, 345/08 e 378/08), peso da parte aérea sem a cepa (94/08 e 272/08) e (390/08, 406/08, 390/08, 378/08 e 341/08), porcentagem de amido nas raízes (26/08, 272/08, 259/08 e 450/08) e (378/08, 413/08, 390/08 e a testemunha IAC 576-70), produtividade de raízes (215/08) e (testemunha IAC 576-70, 341/08, 406/08, 390/08 e 387/08). Com relação ao tempo de cocção na safra 2011/2012, todos os clones necessitaram de tempo inferior a 30 minutos. Em relação ao teor de carotenóides totais nas raízes os clones de amarelada que se destacaram foram 91/08, 94/08, 215/08, 246/08, 272/08 e 497/08, e, naqueles de raízes rosada, os clones 406/08 e 341/08. Em relação ao teor de proteínas nas raízes amarelada, os clones 26/08, 90/08 e 91/08, foram os melhores enquanto nas raízes rosada se destacaram os clones 406/08 e a testemunha IAC 576-70. Os teores de HCN nas raízes de reserva de mandioca foram inferiores a 100 mg kg-1 em todos os clones avaliados. Diferenças significativas entre clones de mandioca de polpas amarelada e rosada foram verificadas para todas as características agronômicas, morfológicas e bioquímicas avaliadas. Os clones tiveram bom desempenho nas avaliações para o cultivo comercial na região do Cerrado e, alguns destes, têm potencial para utilização no melhoramento visando o incremento de carotenóides. ABSTRACT: Cassava (Manihot esculenta Crantz) is considered a relevant species as a food source for the world's population, particularly for developing and emerging countries. The cassava is a provider of energy from starch accumulated in their reserve roots, but it is also important to highlight the presence of carotenoids with antioxidant activity. In this context, this study aimed to characterize, using morphological, agronomic and biochemical, descriptors elite clones from sweet cassava of yellowish and pinkish pulps from the cassava breeding program at Embrapa Cerrados. They were characterized for two crops, 13 edible cassava clones with yellowish pulp and 8 clones with pinkish pulp, compared with the control variety IAC 576-70 (BGMC 753). To evaluate the morphological characteristics were obtained 40 qualitative descriptors for each clone. Both clones the yellowish pulp as those the roots the pinkish pulp, there was morphological differences among clones, showing that no clone showed 100% similarity. The year / crop factor did not influence the phenotypic expression of measured characters. Based on cofenetic coefficient, was found high fit between the graphical representation via dendrogram of r = 0.80 in the roots of yellowish pulp and r = 0.92 in the pinkish of genetic dissimilarity matrix. Among the measured characters, those with the highest entropy in the yellowish roots were, the color of the outer epidermis, the central lobe shape of the leaf and root cortex color, whereas the pinkish was the color to disc, central lobe shape and petiole color. We also performed the characterization based on plant height, the first branch point, and shoot weight without strain, productivity in roots, and index of starch in the roots determines by the method of hydrostatic balance, time for cooking and acid cyanide content in the roots. Based on the evaluated characters, clones stood out with pulps yellowish and pinkish respectively, characters height of the first branch (273/08 and 259/08) and (390/08, 345/08 and the witness IAC 576-70), plant height (90 / 08, 272/08, 273/08, 497/08, 259/08 and 450/08) and (390/08, 345/08 and 378/08), shoot weight without strain (94/08 and 272/08) and (390/08, 406/08, 390/08, 378/08 and 341/08), percentage of starch in the roots (26/08, 272/08, 259/08 and 450/08) and (378/08, 413/08, 390/08 and the witness IAC 576-70), roots of productivity (215/08) and (witnesses IAC 576-70, 341/08, 406/08, 390/08 and 387/08). Regarding the cooking time in the 2011/2012 harvest, all clones showed time less than 30 minutes. Regarding the total carotenoid content in the pulps clones of yellowish roots that stood out were 91/08, 94/08, 215/08, 246/08, 272/08 and 497/08, and, those the clones with pulp pinkish 406/08 and 341/08. Regarding the protein content in yellowish roots the clones 26/08, 90/08 and 91/08, was the best while the pinkish roots highlight clones 406/08 and witness IAC 576-70. The levels of HCN in reserve roots of cassava were less than 100 mg kg-1em all evaluated clones. Significant differences between yellowish and pinkish of pulps cassava clones were checked for all agronomic, morphological and biochemical characteristics evaluated. The clones had well in the ratings for commercial cultivation in the Cerrado region and some of these, clones has potential for use in breeding aimed at increase of carotenoids.
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The bioaccumulation and elimination of endosulfan in zebra fish (Brachydanio rerio) were investigated in a semi-static bioassay. The pesticide mean concentration in water was 03ug litre(-1) and the level of endosulfan residues (x(alfa)+B(beta)-isomers+endosulfan sulfate) in the exposed fish at day 21 was 0.81 (+-0.12)ug g(-1) body weight. The estimated value of the bioconcentration factor (BCF) was 2650 (+-441), the total endosulfan residues being eliminated with a biological half-life of four days. Histopathological studies showed predominantly lipid accumulation in the liver and necrotic focus in the gills of exposed fish.
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The duckweed Lemna valdiviana is commonly founded colonizing small shallow waters (lakes on the lowland in south Brazil. This organism may have been affected by herbicide input into lakes from aerial application and/or drainage office paddy fields. Clomazone (2- (2-chlorophenyl) methyl-4.4-dimethyl-3-isoxazolidinone) is one of the herbicides more fiequentely used as post-emergence in rice paddies. For this work assays were carried as EC50(96h) semi-statics with aseptic culture. The sterile fronds were abtained from material harvest on the paddy fields, and the concentration of Clomazone ranged from 14.0 to 229.0 mg/l. two procedures were considered: diluted in water and sprayed applicated Clomazone. The observed phytotoxic effects were evaluated by growth rate (kt), duplication time (Td), frond yield, plant yield, mortality, chlorophyll a and b and protochlorophyll concentration. The EC50 values obtained to sprayed Clomazone (Kt=31.7; Td=31.9) were significantly small than to diluted Clomazone (Kt=46.4; td=47.3). These dadta suggest that aerial route is more hazardous than diluted procedure. Presence of chlorotic, necrotic, abnormal and died frond were common at the 114.0 and 229.0 mg/l treatment. Recuperation test corroborated the evidence that the sprayed procedure were more deleterious and L. valdiviana doesn't recovery his reproductive ability at the 114.0 and 229.0 mg/l treatment.
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This thesis explores the advancement of cancer treatment through targeted photodynamic therapy (PDT) using bioengineered phages. It aims to harness the specificity of phages for targeting cancer-related receptors such as EGFR and HER2, which are pivotal in numerous malignancies and associated with poor outcomes. The study commenced with the M13EGFR phage, modified to target EGFR through pIII-displayed EGFR-binding peptides, demonstrating enhanced killing efficiency when conjugated with the Rose Bengal photosensitizer. This phase underscored phages' potential in targeted PDT. A breakthrough was achieved with the development of the M137D12 phage, engineered to display the 7D12 nanobody for precise EGFR targeting, marking a shift from peptide-based to nanobody-based targeting and yielding better specificity and therapeutic results. The translational potential was highlighted through in vitro and in vivo assays employing therapeutic lasers, showing effective, specific cancer cell killing through a necrotic mechanism. Additionally, the research delved into the interaction between the M13CC phage and colon cancer models, demonstrating its ability to penetrate and disrupt cancer spheroids only upon irradiation, indicating a significant advancement in targeting cells within challenging tumor microenvironments. In summary, the thesis provides a thorough examination of the phage platform's efficacy and versatility for targeted PDT. The promising outcomes, especially with the M137D12 phage, and initial findings on a HER2-targeting phage (M13HER2), forecast a promising future for phage-mediated, targeted anticancer strategies employing photosensitizers in PDT.