3D stability orbits close to 433 Eros using an effective polyhedral model method

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

The Water Effect on the Kinetics of the Bovine Liver Catalase

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Efeitos endócrinos, anti-inflamatórios e na atividade pedométrica após as administrações de flunixin meglumine e de meloxicam no pós-operatório de laparotomias em bezerros

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Effective field theory methods to model compact binaries

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

Optimisation of a sample preparation method for the determination of fumonisin B-1 in rice

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Development and validation of UV spectrophotometric method for orbifloxacin assay and dissolution studies

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

Laparoscopy hepatic biopsy through cauterization

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Melanose da margem palpebral com suspeita de malignidade: relato de caso

Apresenta-se relato de caso de paciente parda, com 47 anos de idade, havendo lesão pigmentada na margem palpebral inferior do olho direito, de aspecto irregular e heterogêneo, suspeitando-se clinicamente de lesão maligna. A paciente foi tratada com base no resultado da citologia de impressão e diagnosticada pelo exame histológico. Demonstra-se a importância da citologia para o planejamento da ressecção de lesões suspeitas como um método seguro e efetivo para assim se evitar cirurgias em áreas extensas da superfície ocular e de anexos.

Reduction of humeroulnar congenital elbow luxation in 8 dogs by using the transarticular pin

The purpose of this study was to evaluate the clinical and radiographic outcome in 8 dogs of surgical reduction of congenital humeroulnar luxation by using the transarticular pin. Five cases were bilateral and 3 were unilateral, for a total of 13 elbows. The treatment was performed in animals between 45 and 150 days of age. Articular stabilization was achieved by using a transarticular pin driven from the caudal aspect of the olecranon into the body of the humerus or into the distal condyle and distal metaphysis of the humerus. The follow-up period was between 1 and 19 months. There were 5 postsurgical reluxations, 3 related to the insertion of the pin into the humeral condyle and 3 related to the insertion into the humeral body. These animals needed further surgery. Six animals showed near normal return to limb function and 2 had lameness. We conclude that the use of the transarticular pin is an effective and simple method for the treatment of humeroulnar congenital elbow luxation.

Evaluation of the Diramic system for urine cultures

O sistema Diramic foi avaliado para o diagnóstico das infecções do trato urinário (ITU). O sistema Diramic foi desenvolvido em Cuba e possibilita resultados de diagnóstico das infecções do trato urinário (ITU) em quatro horas e baseia-se na variação da turvação do crescimento microbiano no meio de cultura após incubação a 37ºC/4 horas. 396 amostras de urinas provenientes de ambulatórios e enfermarias do HC da FMB-UNESP-Botucatu/SP foram analisadas pelo sistema Diramic. O método da alça calibrada (AC) foi adotado como método de referência. A taxa de coincidência entre os dois métodos foi de 96,46% (382 amostras de urina), não havendo diferença significativa entre os resultados obtidos nos dois métodos. Os resultados para sensibilidade e especificidade foram 84,37 e 98,80% respectivamente e 10 resultados no Diramic foram falsos negativos (2,5%) e 4 falso positivos (1,01%). Os microrganismos identificados nas urinas positivas foram Escherichia coli (68,75%), Klebsiella pneumoniae (10,94%), leveduras (6,25%), Pseudomonas aeruginosa (4,69%), Enterobacter cloacae (3,12%) e Proteus mirabilis, Staphyloccocus coagulase negativo, Morganella morganii e Citrobacter freundii também foram identificadas (1,56% para cada espécie). O método Diramic foi eficiente na triagem das urinoculturas, porém verificou-se algumas restrições quanto ao diagnóstico das infecções do trato urinário quando causadas por leveduras e em pacientes submetidos a antibioticoterapia.

Allosteric water and phosphate effects in Hoplosternum littorale hemoglobins

This paper reports the results obtained using the osmotic stress method applied to the purified cathodic and anodic hemoglobins (Hbs) from the catfish Hoplosternum littorale, a species that displays facultative accessorial air oxygenation. We demonstrate that water potential affects the oxygen affinity of H. littorale Hbs in the presence of an inert solute (sucrose). Oxygen affinity increases when water activity increases, indicating that water molecules stabilize the high-affinity state of the Hb. This effect is the same as that observed in tetrameric vertebrate Hbs. We show that both anodic and cathodic Hbs show conformational substrates similar to other vertebrate Hbs. For both Hbs, addition of anionic effectors, especially chloride, strongly increases the number of water molecules bound, although anodic Hb did not exhibit sensitivity to saturating levels of ATP. Accordingly, for both Hbs, we propose that the deoxy conformations coexist in at least two anion-dependent allosteric states, T-o and T-x, as occurs for human Hb. We found a single phosphate binding site for the cathodic Hb.

Dano de frio em limas-ácidas Tahiti, colhidas em diferentes épocas e submetidas a tratamentos térmicos e bioquímicos

O estudo objetivou o estabelecimento de um método efetivo e satisfatório do controle do dano de frio em limas-ácidas. Os frutos colhidos no município de Boa Vista-RR, 140 e 150 dias após a floração, apresentaram valores médios de 7,9 e 8,2 ºBrix; 6,3 e 6,0 mL de ácido cítrico.100mL de polpa-1 e pH de 2,8 e 3,0, respectivamente, nas duas colheitas. Após cada colheita, os frutos foram levados ao laboratório de Fitotecnia/UFRR, onde foram selecionados, limpos e submetidos aos tratamentos: T1 - controle; T2, T3 e T4 - condicionamento a 35ºC, por 6, 12 e 24 horas, respectivamente; T5 - aquecimento intermitente a 20ºC, por 8 horas, após 5 e 10 dias a 1ºC; T6 - aquecimento intermitente a 20ºC, por 8 horas, após 10 e 20 dias a 1ºC; T7 - ethephon a 1.500 mg.L-1; T8 - ethephon a 3.000 mg.L-1. Os tratamentos T9 ao T16, diferenciaram-se dos tratamentos T1 a T8, apenas, na data da colheita (10 dias após a primeira). O experimento foi avaliado a cada 15 dias, durante 75 dias, a 1 ± 0,5 ºC e 92 ± 5 % de UR, quanto ao dano de frio, aspecto visual, perda de massa fresca, sólidos solúveis (SS), acidez titulável (AT), SS/AT (ratio - RT), clorofila total e ácido ascórbico. O atraso na colheita não proporcionou efeito significativo algum. Todos os tratamentos, à exceção do controle e do aquecimento intermitente aos 10 e 20 dias, foram eficientes no controle do dano de frio. No entanto, o tratamento químico e o condicionamento térmico aceleraram precocemente o metabolismo dos frutos, principalmente no que concerne à perda de massa fresca e ao aspecto visual. O maior teor de clorofila total e de ácido ascórbico, bem como o melhor aspecto visual, a não-incidência de podridões e a menor perda de massa fresca foram detectadas nos frutos submetidos ao aquecimento intermitente aos 5 e 10 dias. Os SS, AT e RT estavam dentro dos padrões de qualidade e não variaram estatisticamente entre os tratamentos.

Whydration effects on DNA double helix stability modulates ligand binding to natural DNA in response to changes in water activity

In this work we present evidence that water molecules are actively involved on the control of binding affinity and binding site discrimination of a drug to natural DNA. In a previous study, the effect of water activity (a(w)) on the energetic parameters of actinomycin-D intercalation to natural DNA was determined using the osmotic stress method (39). This earlier study has shown evidence that water molecules act as an allosteric regulator of ligand binding to DNA via the effect of water activity on the long-range stability of the DNA secondary structure. In this work we have carried out DNA circularization experiments using the plasmid pUC18 in the absence of drugs and in the presence of different neutral solutes to evaluate the contribution of water activity to the energetics of DNA helix unwinding. The contribution of water to these independent reactions were made explicit by the description of how the changes in the free energy of ligand binding to DNA and in the free energy associated with DNA helix torsional deformation are linked to a(w) via changes in structural hydration. Taken together, the results of these studies reveal an extensive linkage between ligand binding affinity and site binding discrimination, and long range helix conformational changes and DNA hydration, This is strong evidence that water molecules work as a classical allosteric regulator of ligand binding to the DNA via its contribution to the stability of the double helix secondary structure, suggesting a possible mechanism by which the biochemical machinery of DNA processing takes advantage of the low activity of water into the cellular milieu.

Novel allosteric conformation of human HB revealed by the hydration and anion effects on O-2 binding

The effect of anions on the stability of different functional conformations of Hb is examined through the determination of the dependence of O-2 affinity on water activity (a(w)). The control of a(w) is effected by varying the sucrose osmolal concentration in the bathing solution according to the osmotic stress method. Thus, the hydration change following Hb oxygenation is determined as a function of Cl- and of DPG concentration. We find that only similar to 25 additional water molecules bind to human Hb during the deoxy-to-oxy conformation transition in the absence of anions, in contrast with similar to 72 that bind in the presence of more than 50 mM Cl- or more than 15 mu M DPG. We demonstrate that the increase in the hydration change linked with oxygenation is coupled with anion binding to the deoxy-Hb. Hence, we propose that the deoxy-Hb coexists in two allosteric conformations which depend on whether anion is bound or not: the tense T-state, with low oxygen affinity and anion bound, or a new allosteric P-state, with intermediate oxygen affinity and free of bound anions. The intrinsic oxygen affinity of this unforeseen P-state and the differential binding of Cl-, DPG, and H2O between states P and T and P and R are characteristics which are consistent with those expected for a putative intermediate allosteric state of Hb. These findings represent a new opportunity to explore the structure-function relationships of hemoglobin regulation.

Water regulation of actinomycin-D binding to DNA: the interplay among drug affinity, DNA long-range conformation, and hydration

Actiaomycin-D (actD) binds to natural DNA at two different classes of binding sites, weak and strong. The affinity for these sites is highly dependent on DNA se(sequence and solution conditions, and the interaction appears to be purely entropic driven Although the entropic character of this reaction has been attributed to the release of water molecules upon drug to DNA complex formation, the mechanism by which hydration regulates actD binding and discrimination between different classes of binding sites on natural DNA is still unknown. In this work, we investigate the role of hydration on this reaction using the osmotic stress method. We skew that the decrease of solution water activity, due to the addition of sucrose, glycerol ethylene glycol, and betaine, favors drug binding to the strong binding sites on DNA by increasing both the apparent binding affinity Delta G, and the number of DNA base pairs apparently occupied by the bound drug n(bp/actD). These binding parameters vary linearly with the logarithm of the molar fraction of water in solution log(X-w), which indicates the contribution of water binding to the energetic of the reaction. It is demonstrated that the hydration change measured upon binding increases proportionally to the apparent size of the binding site n(bp/uctD). This indicates that n(bp/actD) measured from the Scatchard plod is a measure of the size of the DNA molecule changing conformation due to ligand binding. We also find that the contribution of DNA deformation, gauged by n(bp/act) to the total free energy of binding Delta G, is given by Delta G = Delta G(local) + n(bp/actD) x delta G(DNA), where Delta G(local), = -8020 +/- 51 cal/mol of actD bound and delta G(DNa) = -24.1 +/- 1.7cal/mol of base pair at 25 degrees C. We interpret Delta G(local), as the energetic contribution due to the direct interactions of actD with the actual tetranucleotide binding site, and it n(bp/actB) X delta G(DNA) as that due to change inconformation, induced by binding, of it n(bp/actD) DNA base pairs flanking the local site. This interpretation is supported by the agreement found between the value of delta G(DNA) and the torsional free energy change measured independently. We conclude suggesting an allosteric model for ligand binding to DNA, such that the increase in binding affinity is achieved by increasing the relaxation of the unfavorable free energy of binding storage at the local site through a larger number of DNA base pairs. The new aspect on this model is that the size of the complex is not fixed but determined by solutions conditions, such as water activity, which modulate the energetic barrier to change helix conformation. These results may suggest that long-range allosteric transitions of duplex DNA are involved in the inhibition of RNA synthesis by actD, and more generally, in the regulation of transcription. (C) 2000 John Wiley & Sons, Inc.