927 research outputs found
Geometric evaluation of stiffened steel plates subjected to transverse loading for naval and offshore applications
This work searched for the optimal geometrical configuration of simply supported stiffened plates subjected to a transverse and uniformly distributed load. From a non-stiffened reference plate, different geometrical configurations of stiffened plates, with the same volume as the reference plate, were defined through the constructal design method. Thus, applying the exhaustive search technique and using the ANSYS software, the mechanical behaviors of all the suggested stiffened plates were compared to each other to find the geometrical configuration that provided the minimum deflection in the plate's center when subjected to this loading. The optimum geometrical configuration of stiffeners is presented at the end of this work, allowing a reduction of 98.57% for the central deflection of the stiffened plate if compared to the reference plate. Furthermore, power equations were adjusted to describe the deflections for each combination of longitudinal and transverse stiffeners as a function of the ratio between the height and the thickness of the stiffeners. Finally, a unique equation for determining the central deflections of the studied stiffened plates based only on the number of longitudinal stiffeners without significantly losing accuracy has been proposed
Purification And Preliminary Crystallographic Analysis Of A New Lys49-pla2 From B. Jararacussu
BjVIII is a new myotoxic Lys49-PLA2 isolated from Bothrops jararacussu venom that exhibits atypical effects on human platelet aggregation. To better understand the mode of action of BjVIII, crystallographic studies were initiated. Two crystal forms were obtained, both containing two molecules in the asymmetric unit (ASU). Synchrotron radiation diffraction data were collected to 2.0 Å resolution and 1.9 Å resolution for crystals belonging to the space group P2 12 12 1 (a = 48.4 Å, b = 65.3 Å, c = 84.3 Å) and space group P3 121 (a = b = 55.7 Å, c = 127.9 Å), respectively. Refinement is currently in progress and the refined structures are expected to shed light on the unusual platelet aggregation activity observed for BjVIII. © 2008 by the authors; licensee Molecular Diversity Preservation International.95736750van Deenen, L., de Haas, G., Heemskerk, C.H., Hydrolysis of synthetic mixed-acid phosphatides by phospholipase A from human pancreas (1963) Biochim Biophys Acta, 67, pp. 295-304Higuchi, D.A., Barbosa, C.M.V., Bincoletto, C., Chagas, J.R., Magalhaes, A., Richardson, M., Sanchez, E.F., Pesquero, J., L.. Purification and partial characterization of two phospholipases A2 from Bothrops leucurus (white-tailed-jararaca) snake venom (2007) Biochimie, 89, pp. 319-328Maraganore, J.M., Merutka, G., Cho, W., Welches, W., Kézdy, F.J., Heinrikson, R.L., A new class of phospholipases A2 with lysine in place of aspartate 49. Functional consequences for calcium and substrate binding (1984) J Biol Chem, 259, pp. 13839-13843Nakai, M., Nakashima, K.I., Ogawa, T., Shimohigashi, Y., Hattori, S., Chang, C.C., Ohno, M., Purification and primary structure of a myotoxic lysine-49 phospholipase A2 with low lipolytic activity from Trimeresurus gramineus venom (1995) Toxicon, 33, pp. 1469-1478Koh, D.C.I., Armugam, A., Jeyaseelan, K., Snake venom components and their applications in biomedicine (2006) Cell Mol Life Sci, 63, pp. 3030-3041Andrião-Escarso, S.H., Soares, A.M., Fontes, M.R.M., Fuly, A.L., Corrêa, F.M.A., Rosa, J.C., Greene, L.J., Giglio, J., R.. Structural and functional characterization of an acidic platelet aggregation inhibitor and hypotensive phospholipase A(2) from Bothrops jararacussu snake venom (2002) Biochem Pharmacol, 64, pp. 723-732Fuly, A.L., Soares, A.M., Marcussi, S., Giglio, J.R., Guimarães, J.A., Signal transduction pathways involved in the platelet aggregation induced by a D-49 phospholipase A2 isolated from Bothrops jararacussu snake venom (2004) Biochimie, 86, pp. 731-739Magro, A.J., Murakami, M.T., Marcussi, S., Soares, A.M., Arni, R.K., Fontes, M.R.M., Crystal structure of an acidic platelet aggregation inhibitor and hypotensive phospholipase A2 in the monomeric and dimeric states: Insights into its oligomeric state (2004) Biochem Biophys Res Commun, 323, pp. 24-31Toyama, M.H., Carneiro, E.M., Marangoni, S., Barbosa, R.L., Corso, G., Boschero, A.C., Biochemical characterization of two crotamine isoforms isolated by a single step RP-HPLC from Crotalus durissus terrificus (South American rattlesnake) venom and their action on insulin secretion by pancreatic islets (2000) Biochim Biophys Acta, 1474, pp. 56-60Fonseca, F.V., Antunes, E., Morganti, R.P., Monteiro, H.S.A., Martins, A.M.C., Toyama, D.O., Marangoni, S., Toyama, M., H.. Characterization of a new platelet aggregating factor from crotoxin Crotalus durissus cascavella venom (2006) Protein J, 25, pp. 183-192Schägger, H., von Jagow, G., Tricine-sodium dodecyl sulfate-polyacrylamide gel electrophoresis for the separation of proteins in the range from 1 to 100 kDa (1987) Anal Biochem, 166, pp. 368-379McPherson, A., Current approaches to macromolecular crystallization (1990) Eur J Biochem, 189, pp. 1-23Polikarpov, I., Oliva, G., Castellano, E.E., Garratt, R.C., Arruda, P., Leite, A., Craievich, A., The protein crystallography beamline at LNLS, the Brazilian National Synchrotron Light Source (1998) Nucl Instrum Methods Phys Res A, 405, pp. 159-164Polikarpov, I., Perles, L.A., de Oliveira, R.T., Oliva, G., Castellano, E.E., Garratt, R.C., Craievich, A.. Set-up and Experimental Parameters of the Protein Crystallography Beamline at the Brazilian National Synchrotron Laboratory (1998) J Synchrotron Radiat, 5, pp. 72-76Leslie, A.G., W.. The integration of macromolecular diffraction data (2006) Acta Crystallogr D Biol Crystallogr, 62, pp. 48-57Evans, P., Scaling and assessment of data quality (2006) Acta Crystallogr D Biol Crystallogr, 62, pp. 72-82Navaza, J., Implementation of molecular replacement in AMoRe (2001) Acta Crystallogr D Biol Crystallogr, 57, pp. 1367-1372Kozin, M.B., Svergun, D.I., Automated matching of high- and low-resolution structural models (2001) J Appl Crystallogr, 34, pp. 33-41CCP, Collaborative Computational Project, Number 4. The CCP4 suite: Programs for protein crystallography (1994) Acta Crystallogr D Biol Crystallogr, 50, pp. 760-763. , 4Winn, M., Dodson, E.J., Ralph, A., Collaborative computational project, number 4: Providing programs for protein crystallography (1997) Methods Enzymol, 277, pp. 620-633Spencer, P.J., Aird, S.D., Boni-Mitake, M., Nascimento, N., Rogero, J.R., A single-step purification of bothropstoxin-1 (1998) Braz J Med Biol Res, 31, pp. 1125-1127Soares, A.M., Guerra-Sá, R., Borja-Oliveira, C.R., Rodrigues, V.M., Rodrigues-Simioni, L., Rodrigues, V., Fontes, M.R.M., Giglio, J.R., Structural and functional characterization of BnSP-7, a Lys49 myotoxic phospholipase A2 homologue from Bothrops neuwiedi pauloensis venom (2000) Arch Biochem Biophys, 378, pp. 201-209Arni, R.K., Ward, R.J., Gutiérrez, J.M., Tulinsky, A., Structure of a calcium-independent phospholipase-like myotoxic protein from Bothrops asper venom (1995) Acta Crystallogr D Biol Crystallogr, 51, pp. 311-317Murakami, M.T., Viçoti, M.M., Abrego, J.R.B., Lourenzoni, M.R., Cintra, A.C.O., Arruda, E.Z., Tomaz, M.A., Arni, R., K.. Interfacial surface charge and free accessibility to the PLA2-active site-like region are essential requirements for the activity of Lys49 PLA2 homologues (2007) Toxicon, 49, pp. 378-387Toyama, M.H., Soares, A.M., Vieira, C.A., Novello, J.C., Oliveira, B., Giglio, J.R., Marangoni, S.. Amino acid sequence of piratoxin-I, a myotoxin from Bothrops pirajai snake venom, and its biological activity after alkylation with p-bromophenacyl bromide (1998) J Protein Chem, 17, pp. 713-718Barbosa, P. S. F.Martins, A. M. C.Alves, R. S.Amora, D. N.Martins, R. D.Toyama, M. H.Havt, A.Nascimento, N. R. F.Rocha, V. L. C.Menezes, D. B.Fonteles, M. C.Monteiro, H. S. A. . The role of indomethacin and tezosentan on renal effects induced by Bothrops moojeni Lys49 myotoxin I. Toxicon 2006, 47, 831-837Kramer, R.M., Roberts, E.F., Manetta, J.V., Hyslop, P.A., Jakubowski, J., A.. Thrombin-induced phosphorylation and activation of Ca(2+)-sensitive cytosolic phospholipase A2 in human platelets (1993) J Biol Chem, 268, pp. 26796-26804Puri, R., N.. Phospholipase A2: Its role in ADP- and thrombin-induced platelet activation mechanisms (1998) Int J Biochem Cell Biol, 30, pp. 1107-1122Soares, A.M., Andrião-Escarso, S.H., Angulo, Y., Lomonte, B., Gutiérrez, J.M., Marangoni, S., Toyama, M.H., Giglio, J.R., Structural and functional characterization of myotoxin I, a Lys49 phospholipase A(2) homologue from Bothrops moojeni (Caissaca) snake venom (2000) Arch Biochem Biophys, 373, pp. 7-15Singh, N., Jabeen, T., Pal, A., Sharma, S., Perbandt, M., Betzel, C., Singh, T.P., Crystal structures of the complexes of a group IIA phospholipase A2 with two natural anti-inflammatory agents, anisic acid, and atropine reveal a similar mode of binding (2006) Proteins, 64, pp. 89-100Kini, R.M., Evans, H.J., A model to explain the pharmacological effects of snake venom phospholipases A2 (1989) Toxicon, 27, pp. 613-635Gutiérrez, J.M., Lomonte, B., Phospholipase A2 myotoxins from Bothrops snake venoms (1995) Toxicon, 33, pp. 1405-1424Ownby, C.L., de Araujo, H.S.S., White, S.P., Fletcher, J., E.. Lysine 49 phospholipase A2 proteins (1999) Toxicon, 37, pp. 411-445Yang, C. C.. In Venom Phospholipase A2 enzymes: Structure, Function and MechanismKini, R. M., Ed.John Wiley & Sons: UK, 1997Chapter Chemical modification and functional sites of phospholipases A2, p 185Stiles, B. G.Choumet, V.. In Venom Phospholipase A2 enzymes: Structure, Function and MechanismKini, R. M., Ed.John Wiley & Sons: UK, 1997Chapter Antibodies studies with venom phospholipases A2, p 223Matthews, B., W.. Solvent content of protein crystals (1968) J Mol Biol, 33, pp. 491-497Altschul, S.F., Madden, T.L., Schäffer, A.A., Zhang, J., Zhang, Z., Miller, W., Lipman, D., J.. Gapped BLAST and PSI-BLAST: A new generation of protein database search programs (1997) Nucleic Acids Res, 25, pp. 3389-3402Magro, A.J., Soares, A.M., Giglio, J.R., Fontes, M.R.M., Crystal structures of BnSP-7 and BnSP-6, two Lys49-phospholipases A(2): Quaternary structure and inhibition mechanism insights (2003) Biochem Biophys Res Commun, 311, pp. 713-72
Electrochemical studies on small electron transfer proteins using membrane electrodes
Journal of Electroanalytical Chemistry 541 (2003) 153-162Membrane electrodes (ME) were constructed using gold, glassy carbon and pyrolytic graphite supports and a dialysis membrane,
and used to study the electrochemical behavior of small size electron transfer proteins: monohemic cytochrome c522 from
Pseudomonas nautica and cytochrome c533 as well as rubredoxin from Desulfovibrio vulgaris . Different electrochemical techniques were used including cyclic voltammetry (CV), square wave voltammetry (SW) and differential pulse voltammetry (DP). A direct electrochemical response was obtained in all cases except with rubredoxin where a facilitator was added to the protein solution entrapped between the membrane and the electrode surface. Formal potentials and heterogeneous charge transfer rate constants
were determined from the voltammetric data. The influence of the ionic strength and the pH of the medium on the electrochemical
response at the ME were analyzed. The benefits from the use of the ME in protein electrochemistry and its role in modulating the redox behavior are analyzed. A critical comparison is presented with data obtained at non-MEs. Finally, the interactions that must be established between the proteins and the electrode surfaces are discussed, thereby modeling molecular interactions that occur in biological systems
Guess what: Chronic 13q14.3+/CD5‐ /CD23+ lymphocytic leukemia in blood and t(11;14)(q13;q32)+/CD5+/CD23‐ mantle cell lymphoma in lymph nodes!
Cytometry B Clin Cytom. 2003 Jan;51(1):41-4.
Guess what: Chronic 13q14.3+/CD5-/CD23+ lymphocytic leukemia in blood and t(11;14)(q13;q32)+/CD5+/CD23- mantle cell lymphoma in lymph nodes!
Lima M, Pinto L, Dos Anjos Teixeira M, Canelhas A, Mota A, Cabeda JM, Silva C, Queirós ML, Fonseca S, Santos AH, Brochado P, Justiça B.
Service of Clinical Hematology, Hospital Geral de Santo António, Porto, Portugal. [email protected]
Abstract
We report a case of a patient with two B-cell lymphoproliferative disorders: CD5(-)/CD23(+) B-cell chronic lymphocytic leukemia and CD5(+)/CD23(-) mantle cell lymphoma. These disorders were diagnosed simultaneously based on flow cytometry, immunohistochemistry, fluorescence in situ hybridization, and polymerase chain reaction-based molecular studies. The B-cell lymphocytic leukemia clone predominated in the blood and bone marrow, whereas the mantle cell clone predominated in lymph nodes.
Copyright 2002 Wiley-Liss, Inc.
PMID: 12500296 [PubMed - indexed for MEDLINE
Nonextensive Entropies derived from Form Invariance of Pseudoadditivity
The form invariance of pseudoadditivity is shown to determine the structure
of nonextensive entropies. Nonextensive entropy is defined as the appropriate
expectation value of nonextensive information content, similar to the
definition of Shannon entropy. Information content in a nonextensive system is
obtained uniquely from generalized axioms by replacing the usual additivity
with pseudoadditivity. The satisfaction of the form invariance of the
pseudoadditivity of nonextensive entropy and its information content is found
to require the normalization of nonextensive entropies. The proposed principle
requires the same normalization as that derived in [A.K. Rajagopal and S. Abe,
Phys. Rev. Lett. {\bf 83}, 1711 (1999)], but is simpler and establishes a basis
for the systematic definition of various entropies in nonextensive systems.Comment: 16 pages, accepted for publication in Physical Review
Clinicobiological, immunophenotypic, and molecular characteristics of monoclonal CD56‐/+dim chronic natural killer cell large granular lymphocytosis.
Am J Pathol. 2004 Oct;165(4):1117-27.
Clinicobiological, immunophenotypic, and molecular characteristics of monoclonal CD56-/+dim chronic natural killer cell large granular lymphocytosis.
Lima M, Almeida J, Montero AG, Teixeira Mdos A, Queirós ML, Santos AH, Balanzategui A, Estevinho A, Algueró Mdel C, Barcena P, Fonseca S, Amorim ML, Cabeda JM, Pinho L, Gonzalez M, San Miguel J, Justiça B, Orfão A.
Serviço de Hematologia, Unidade de Citometria, Hospital Geral de Santo António, Rua D Manuel II, s/n, 4099-001 Porto, Portugal. [email protected].
Abstract
Indolent natural killer (NK) cell lymphoproliferative disorders include a heterogeneous group of patients in whom persistent expansions of mature, typically CD56(+), NK cells in the absence of any clonal marker are present in the peripheral blood. In the present study we report on the clinical, hematological, immunophenotypic, serological, and molecular features of a series of 26 patients with chronic large granular NK cell lymphocytosis, whose NK cells were either CD56(-) or expressed very low levels of CD56 (CD56(-/+dim) NK cells), in the context of an aberrant activation-related mature phenotype and proved to be monoclonal using the human androgen receptor gene polymerase chain reaction-based assay. As normal CD56(+) NK cells, CD56(-/+dim) NK cells were granzyme B(+), CD3(-), TCRalphabeta/gammadelta(-), CD5(-), CD28(-), CD11a(+bright), CD45RA(+bright), CD122(+), and CD25(-) and they showed variable and heterogeneous expression of both CD8 and CD57. Nevertheless, they displayed several unusual immunophenotypic features. Accordingly, besides being CD56(-/+dim), they were CD11b(-/+dim) (heterogeneous), CD7(-/+dim) (heterogeneous), CD2(+) (homogeneous), CD11c(+bright) (homogeneous), and CD38(-/+dim) (heterogeneous). Moreover, CD56(-/+dim) NK cells heterogeneously expressed HLA-DR. In that concerning the expression of killer receptors, CD56(-/+dim) NK cells showed bright and homogeneous CD94 expression, and dim and heterogeneous reactivity for CD161, whereas CD158a and NKB1 expression was variable. From the functional point of view, CD56(-/+dim) showed a typical Th1 pattern of cytokine production (interferon-gamma(+), tumor necrosis factor-alpha(+)). From the clinical point of view, these patients usually had an indolent clinical course, progression into a massive lymphocytosis with lung infiltration leading to death being observed in only one case. Despite this, they frequently had associated cytopenias as well as neoplastic diseases and/or viral infections. In summary, we describe a unique and homogeneous group of monoclonal chronic large granular NK cell lymphocytosis with an aberrant activation-related CD56(-/+dim)/CD11b(-/+dim) phenotype and an indolent clinical course, whose main clinical features are related to concomitant diseases.
PMID: 15466379 [PubMed - indexed for MEDLINE]PMCID: PMC161863
Competition between two high- and low-affinity protein-binding sites in myosin VI controls its cellular function.
Myosin VI is involved in many cellular processes ranging from endocytosis to transcription. This multifunctional potential is achieved through alternative isoform splicing and through interactions of myosin VI with a diverse network of binding partners. However, the interplay between these two modes of regulation remains unexplored. To this end, we compared two different binding partners and their interactions with myosin VI by exploring the kinetic properties of recombinant proteins and their distribution in mammalian cells using fluorescence imaging. We found that selectivity for these binding partners is achieved through a high-affinity and a low-affinity motif within myosin VI. These two motifs allowed competition among partners for myosin VI. Exploring how this competition affects the activity of nuclear myosin VI, we demonstrate the impact of a concentration-driven interaction with the low-affinity binding partner DAB2, finding that this interaction blocks the ability of nuclear myosin VI to bind DNA and its transcriptional activity in vitro. We conclude that loss of DAB2, a tumor suppressor, may enhance myosin VI–mediated transcription. We propose that the frequent loss of specific myosin VI partner proteins during the onset of cancer leads to a higher level of nuclear myosin VI activity
Changes of Several Psychological Measures in the Patients with Craniomandibular Disorders, Bruxing Behavior and Sexual Abuse History
Aim: The understanding of psychological correlates of Craniomandibular disorders and Bruxing Behavior has seen significant progress in the last few years. However, studies evaluating association between more complex psychological measures in such disorders are extremely scarce. To investigate this, we evaluated frequency of sexual abuse history in the experimental and two control groups and scores in depression, somatization and dissociation in those with Craniomandibular Disorders and Bruxism with/without sexual abuse history.Methods: Clinical examination, self-report, chief complaint, criteria for craniomandibular disorders and bruxism, the Becker-Lausen Questionnaire for sexual abuse were used in the Craniomandibular Disorder+ Bruxing Behavior, and in two control subgroups to gather data about sexual abuse history. The Beck Depression Inventory (BDI), 32 questions from the Screening Somatoform Disorders (SOMS-2) instrument and the Dissociative Experience Scale (DES) were used in the Craniomandibular Disorder + Bruxism + Sexual Abuse (n=39), in the Craniomandibular Disorder + Bruxism with no sexual abuse subgroup (n=158) and in the no Craniomandibular Disorders no Sexual Abuse subgroup (n=50) so as to gather data about depression, somatization and dissociation, respectively.Results: We show that there was no a statistically significant difference when comparing frequency of sexual abuse history in the experimental and in the two control groups. Means in depression were about 14.7; 11.4; and 9.3 in the Craniomandibular Disorder + Bruxism and Sexual abuse, in the Craniomandibular Disorder + Bruxism with no sexual abuse history, and in the no Craniomandibular Disorders no Sexual abuse history subgroups, respectively (Kruskall-Wallis statistics with post test p<0.02). Means in somatization were 12.1, 10.3, and 8.0, respectively in those subgroups (p<0.006). Means in dissociation were about 22.3, 15.6, and 15.2, respectively (p<0.007).Conclusions: Means in depression, somatization and dissociation were higher and significantly different in the Craniomandibular + bruxing behavior + sexual abuse history subgroup. This study provides further data on frequency of sexual abuse in craniomandibular disorder and bruxer subjects, expands current knowledge about depression and somatization and provides non previously reported data on dissociation
Polycyclic aromatic hydrocarbons in superficial sediments of the Negro River in the Amazon region of Brazil
Polycyclic aromatic hydrocarbons (PAHs) were identified and quantified in samples of superficial sediments of the Negro River, in the Amazon region of Brazil, through analyses performed by GC/MS. Total PAH concentration that includes parent and alkylated PAHs ranged from 6.5 to 5348 ng g-1 of dry weight. The Σ16 PAHs prioritized in environmental studies by the U.S. Environmental Protection Agency (USEPA) ranged from 5.6 to 1187 ng g-1. The most contaminated places were those where muddy sediments were found, with the highest concentrations of organic matter, carbon and total nitrogen. The priority PAHs with high molecular weight represented 70% of the total abundance and showed that the main source of contamination of the sediments was pyrogenic. However, petrogenic PAHs coming from oil and derivatives input is also an important contamination source to be considered. ©2015 Sociedade Brasileira de Química
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