This study aimed at assessing the effects of autologous transendocardial transplantation of bone ... more This study aimed at assessing the effects of autologous transendocardial transplantation of bone marrow mononuclear cells (ATTBMMC) on symptoms, exercise capacity, myocardial perfusion and contractility in patients with severe ischemic heart disease during a 6-month follow-up period. This prospective study comprised 21 patients as follows: the first 14 patients forming the treated group, and the last 7 patients forming the control group. Initially, all patients underwent clinical and laboratory assessment, treadmill testing, echocardiography, myocardial scintigraphy, and 24-hour Holter. The bone marrow mononuclear cells (BMMC) were isolated, washed, and diluted in 0.9% saline solution for transendocardial injection in areas of viable myocardium in the treated group, (15 0.2-mL injections). All patients were reassessed in the end of 2 and 6 months of follow-up. The demographic data and other characteristics did not significantly differ between the groups in the initial evaluation. No...
This study aimed at assessing the effects of autologous transendocardial transplantation of bone ... more This study aimed at assessing the effects of autologous transendocardial transplantation of bone marrow mononuclear cells (ATTBMMC) on symptoms, exercise capacity, myocardial perfusion and contractility in patients with severe ischemic heart disease during a 6-month follow-up period.
Objective: Evaluate the effects of intracoronary autologous bone marrow mononuclear cells transpl... more Objective: Evaluate the effects of intracoronary autologous bone marrow mononuclear cells transplantation (ABMMCT) over left ventricle diastolic function (LVDF) by using Tissue Doppler imaging (TD) Echocardiography . Methods: Open label concealed randomized clinical trial. Nine pts (7 male), were submitted to successful percutaneous coronary intervention (PCI) for ST elevation acute myocardial infarction from the outlet of this study. Patients were
The pathway of electron transport to nitrogenase in the endophytic beta-Proteobacterium Herbaspir... more The pathway of electron transport to nitrogenase in the endophytic beta-Proteobacterium Herbaspirillum seropedicae has not been characterized. We have generated mutants in two nif-associated genes encoding putative ferredoxins, fdxA and fdxN. The fdxA gene is part of the operon nifHDKENXorf1orf2fdxAnifQmodABC and is transcribed from the nifH promoter, as revealed by lacZ gene fusion. The fdxN gene is probably cotranscribed with the nifB gene. Mutational analysis suggests that the FdxA protein is essential for maximum nitrogenase activity, since the nitrogenase activity of the fdxA mutant strain was reduced to about 30% of that of the wild-type strain. In addition, the fdxA mutation had no effect on the nitrogenase switch-off in response to ammonium. Nitrogenase activity of a mutant strain lacking the fdxN gene was completely abolished. This phenotype was reverted by complementation with fdxN expressed under lacZ promoter control. The results suggest that the products of both the fdxA and fdxN genes are probably involved in electron transfer during nitrogen fixation.
An analysis of a series of five peptides composed of various portions of the pleurocidin (Plc) se... more An analysis of a series of five peptides composed of various portions of the pleurocidin (Plc) sequence identified a l2-amino acid fragment from the C-terminus of Plc, designated Plc-2, as the smallest fragment that retained a antimicrobial activity comparable to that of the parent compound. MIC tests in vitro with low-ionic-strength medium showed that Plc-2 has potent activity against Pseudomonas aeruginosa, Escherichia coli and Staphylococcus aureus but not against Enterococcus faecalis. The antifungal activity of the synthetic peptides against phytopathogenic fungi, such as Fusarium oxysporum, Colletotrichum sp., Aspergillus niger and Alternaria sp., also identified Plc-2 as a biologically active peptide. Microscopy studies of fluorescently stained fungi treated with Plc-2 demonstrated that cytoplasmic and nuclear membranes were compromised in all strains of phytopathogenic fungi tested. Together, these results identify Plc-2 as a potential antimicrobial agent with similar properties to its parent compound, pleurocidin. In addition, it demonstrated that the KHVGKAALTHYL residues are critical for the antimicrobial activity described for pleurocidin.
We report an investigation for 16 bacteria and viruses among 184 children hospitalized with pneum... more We report an investigation for 16 bacteria and viruses among 184 children hospitalized with pneumonia in Salvador, Brazil. Etiology was established in 144 (78%) cases. Viral, bacterial, and mixed infections were found in 110 (60%), 77 (42%), and 52 (28%) patients, respectively. Rhinovirus (21%) and Streptococcus pneumoniae (21%) were the most common pathogens. Our results demonstrate the importance of viral and pneumococcal infections among those patients.
In this work we describe the ability of living Crithidia deanei to hydrolyze extracellular ATP. I... more In this work we describe the ability of living Crithidia deanei to hydrolyze extracellular ATP. In intact cells at pH 7.2, a low level of ATP hydrolysis was observed in the absence of any divalent metal (0.41+/-0.13 nmol P(i) h(-1) 10(7) cells(-1)). The ATP hydrolysis was stimulated by MgCl(2) and the Mg(2+)-dependent ecto-ATPase activity was 4.05+/-0.17 nmol P(i) h(-1) 10(7) cells(-1). Mg(2+)-dependent ecto-ATPase activity increased linearly with cell density and with time for at least 60 min. The addition of MgCl(2) to extracellular medium increased the ecto-ATPase activity in a dose-dependent manner. At 5 mM ATP, half-maximal stimulation of ATP hydrolysis was obtained with 0.93+/-0.26 mM MgCl(2). This stimulatory activity was also observed when MgCl(2) was replaced by MnCl(2), but not CaCl(2) or SrCl(2). The apparent K(m) for Mg-ATP(2-) was 0.26+/-0.03 mM. ATP was the best substrate for this enzyme; other nucleotides, such as ITP, GTP, UTP and CTP, produced lower reaction rates. In the pH range from 6.6 to 8.4, in which the cells were viable, the acid phosphatase activity also present in this cell decreased, while the Mg(2+)-dependent ATPase activity did not change. This ecto-ATPase activity was insensitive to inhibitors of other ATPase and phosphatase activities, such as oligomycin, sodium azide, bafilomycin A(1), ouabain, vanadate, molybdate, sodium fluoride and tartrate. To confirm that this Mg(2+)-dependent ATPase was an ecto-ATPase, we used the impermeant inhibitor 4, 4'-diisothiocyanostylbene 2'-2'-disulfonic acid as well as suramin, an antagonist of P(2) purinoreceptors and inhibitor of some ecto-ATPases. These two reagents inhibited the Mg(2+)-dependent ATPase activity in a dose-dependent manner. The cell surface location of the ATP-hydrolyzing site was also confirmed by cytochemical analysis.
Extracellular ATP (ATPo) is capable of inducing different events on cells through receptor activa... more Extracellular ATP (ATPo) is capable of inducing different events on cells through receptor activation. The effect produced by ATPo was studied in the cell line K562 and its multidrug resistant (MDR) counterpart, Lucena 1. Lower ATPo concentrations (1 mM and 2.5 mM) led to high (3)H-thymidine incorporation but no increase in cell number. Similarly, the cell cycle profile indicated an increase of cells in S phase and a decrease in G1 and G2, suggesting that the cells did not duplicate their DNA content. Higher doses of ATP (5 mM and 10 mM), as well as UTP (5 mM) and the P2X(7) agonist BzATP, were cytotoxic. However, no expression of P2X(7) receptors could be detected by Western Blot nor were the cells permeabilised by ATP, suggesting that pore formation was not involved in cell death. Both ecto-ATPase and ecto-5'-nucleotidase activity could be demonstrated at the surfaces of K562 and Lucena 1 cells, the latter presenting a higher ecto-5'-nucleotidase activity. Adenosine induced cell death at lower concentrations (2.5 mM) on both cell lines. Furthermore, an increased number of dead cells could be observed when 5 mM Adenosine was used compared to the same concentrations of ATPo. It still remains to be elucidated the nature of the receptors involved in the induction of cell death in these cells.
The four dominant outer membrane proteins (46, 38, 33 and 28 kDa) were detected by sodium dodecyl... more The four dominant outer membrane proteins (46, 38, 33 and 28 kDa) were detected by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) in a semi-purified preparation of vesicle membranes of a Neisseria meningitidis (N44/89, B:4:P1.15:P5.5,7) strain isolated in Brazil. The Nterminal amino acid sequence for the 46 kDa and 28 kDa proteins matched that reported by others for class 1 and 5 proteins respectively, whereas the sequence (25 amino acids) for the 38 kDa (class 3) protein was similar to class 1 meningococcal proteins. The sequence for the 33 kDa (class 4) was unique and not homologous to any known protein.
The objective of this work was to evaluate the technical feasibility of coupling two membrane sep... more The objective of this work was to evaluate the technical feasibility of coupling two membrane separation processes, reverse osmosis (RO) and osmotic evaporation (OE), in order to concentrate clarified camu-camu juice, focusing on the vitamin C, phenolic compounds and antioxidant activity of the final product. The juice was firstly pre-concentrated by RO, reaching 285 g kg À1 of soluble solids. During this step, the juice's osmotic pressure showed to be the main factor controlling mass transfer. The juice was then concentrated by OE, reaching 530 g kg À1 of soluble solids. Vitamin C, total phenolics and antioxidant activity levels of 94.6 g ascorbic acid kg À1 , 105.2 g galic acid kg À1 and 762 mmol Trolox kg À1 , respectively, were achieved in the final product. The use of integrated membrane processes proved to be an interesting alternative to the concentration of thermosensitive juices, reaching concentration levels up to 7 times for camu-camu juice's bioactive compounds.
In prokaryotes molybdenum is taken up by a high-affinity ABC-type transporter system encoded by t... more In prokaryotes molybdenum is taken up by a high-affinity ABC-type transporter system encoded by the modABC genes. The endophyte β-Proteobacterium Herbaspirillum seropedicae has two modABC gene clusters and two genes encoding putative Mo-dependent regulator proteins (ModE1 and ModE2). Analysis of the amino acid sequence of the ModE1 protein of H. seropedicae revealed the presence of an N-terminal domain containing a DNA-binding helix-turn-helix motif (HTH) and a C-terminal domain with a molybdate-binding motif. The second putative regulator protein, ModE2, contains only the helix-turn-helix motif, similar to that observed in some sequenced genomes. We cloned the modE1 (810 bp) and modE2 (372 bp) genes and expressed them in Escherichia coli as His-tagged fusion proteins, which we subsequently purified. The over-expressed recombinant His-ModE1 was insoluble and was purified after solubilization with urea and then on-column refolded during affinity chromatography. The His-ModE2 was expressed as a soluble protein and purified by affinity chromatography. These purified proteins were analyzed by DNA band-shift assays using the modA2 promoter region as probe. Our results indicate that His-ModE1 and His-ModE2 are able to bind to the modA2 promoter region, suggesting that both proteins may play a role in the regulation of molybdenum uptake and metabolism in H. seropedicae.
Adults and young children prefer to affiliate with some individuals rather than others. Studies h... more Adults and young children prefer to affiliate with some individuals rather than others. Studies have shown that monolingual children show in-group biases for individuals who speak their native language without a foreign accent . Some studies have suggested that bilingual children are less influenced than monolinguals by language variety when attributing personality traits to different speakers , which could indicate that bilinguals have fewer in-group biases and perhaps greater social flexibility. However, no previous studies have compared monolingual and bilingual children's reactions to speakers with unfamiliar foreign accents. In the present study, we investigated the social preferences of 5-year-old English and French monolinguals and English-French bilinguals. Contrary to our predictions, both monolingual and bilingual preschoolers preferred to be friends with native-accented speakers over speakers who spoke their dominant language with an unfamiliar foreign accent. This result suggests that both monolingual and bilingual children have strong preferences for in-group members who use a familiar language variety, and that bilingualism does not lead to generalized social flexibility.
In this work we describe the ability of living Trypanosoma rangeli to hydrolyze extracellular ATP... more In this work we describe the ability of living Trypanosoma rangeli to hydrolyze extracellular ATP. In these intact parasites whose viability was assessed before and after the reactions by motility and by Trypan blue dye exclusion, there was a low level of ATP hydrolysis in the absence of any divalent metal (1.53 § 0.12 nmol Pi/h £ 10 7 cells). The ATP hydrolysis was stimulated by MgCl 2 and the Mg-dependent ecto-ATPase activity was 5.24 § 0.64 nmol Pi/h £ 10 7 cells. The Mg-dependent ecto-ATPase activity was linear with cell density and with time for at least 60 min. This stimulatory eVect on the ATP hydrolysis was also observed when MgCl 2 was replaced by MnCl 2 , but not by CaCl 2 , SrCl 2 , and ZnCl 2 . The apparent K m for Mg-ATP2-was 0.53 § 0.11 mM. The optimum pH for the T. rangeli Mg-dependent ecto-ATPase activity lies in the alkaline range. This ecto-ATPase activity was insensitive to inhibitors of other ATPase and phosphatase activities, such as oligomycin, sodium azide, baWlomycin A1, ouabain, furosemide, vanadate, molybdate, sodium Xuoride, tartrate, and levamizole. To conWrm that this Mg-dependent ATPase was an ecto-ATPase, we used an impermeant inhibitor, DIDS (4, 4Ј-diisothiocyanostylbene 2Ј-2Ј-disulfonic acid) as well as suramin, an antagonist of P2 purinoreceptors and inhibitor of some ecto-ATPases. These two reagents inhibited the Mg 2+ -dependent ATPase activity in a dose-dependent manner. This ecto-ATPase activity was stimulated by carbohydrates involved in the attachment/invasion of salivary glands of Rhodnius prolixus and by lipophorin, an insect lipoprotein circulating in the hemolymph.
The presence of Leishmania amazonensis ecto-nucleoside triphosphate triphosphohydrolase activitie... more The presence of Leishmania amazonensis ecto-nucleoside triphosphate triphosphohydrolase activities was demonstrated using antibodies against diVerent NTPDase members by Western blotting, Xow cytometry, and immunoelectron microscopy analysis. Living promastigote cells sequentially hydrolyzed the ATP molecule generating ADP, AMP, and adenosine, indicating that this surface enzyme may play a role in the salvage of purines from the extracellular medium. The L. amazonensis ecto-NTPDase activities were insensitive to Triton X-100, but they were enhanced by divalent cations, such as Mg 2+ . In addition, the ecto-NTPDase activities decreased with time for 96 h when promastigotes were grown in vitro. On the other hand, these activities increased considerably when measured in living amastigote forms. Furthermore, the treatment with adenosine, a mediator of several relevant biological phenomena, induced a decrease in the reactivity with anti-CD39 antibody, raised against mammalian E-NTPDase, probably because of down regulation in the L. amazonensis ecto-NTPDase expression. Also, adenosine and anti-NTPDase antibodies induced a signiWcant diminishing in the interaction between promastigotes of L. amazonensis and mouse peritoneal macrophages.
Trypanosoma rangeli is a parasite of a numerous wild and domestic animals, presenting wide geogra... more Trypanosoma rangeli is a parasite of a numerous wild and domestic animals, presenting wide geographical distribution and high immunological cross-reactivity with Trypanosoma cruzi, which may lead to misdiagnosis. T. rangeli has a complex life cycle, involving distinct morphological and functional forms in the vector. Here, we characterized the cell surface polypeptides and the phosphatase activities in short and long epimastigotes forms of T. rangeli, using intact living parasites. The surface protein proWle revealed by the incubation of parasites with biotin showed a preferential expression of the 97, 70, 50, 45, 25-22, and 15 kDa biotinylated polypeptides in the long forms, in contrast to the 55 and 28 kDa biotinylated polypeptides synthesized by the short epimastigotes. Additionally, Xow cytometry analysis showed that the short forms had relatively lower biotin surface binding than long ones. The involvement of phosphatases with the trypanosomatid diVerentiation has been proposed. In this sense, T. rangeli living parasites were able to hydrolyze the artiWcial substrate p-nitrophenylphosphate at a rate of 25.57 § 2.03 and 10.09 § 0.93 nmol p-NPP £ h ¡1 £ 10 7 cells for the short and long epimastigotes, respectively. These phosphatase activities were linear with time for at least 60 min and the optimum pH lies in the acid range. Classical inhibitors of acid phosphatases, such as ammonium molybdate, sodium Xuoride, and zinc chloride, showed a signiWcant decrease in these phosphatase activities, with diVerent patterns of inhibition. Additionally, these phosphatase activities presented diVerent kinetic parameters (K m and V max ) and distinct sensitivities to divalent cations. Both epimastigotes were unable to release phosphatase to the extracellular environment. Cytochemical analysis demonstrated the localization of these enzymes on the parasite surfaces (cell body and Xagellum) and in intracellular vacuoles, resembling acidocalcisomes.
We describe cell therapy for severe ischemic heart failure using transendocardial injection of au... more We describe cell therapy for severe ischemic heart failure using transendocardial injection of autologous bone-marrow-derived mononuclear cells. The treated patients had significantly less heart failure and angina, sustained significant improvement of pumping power, exercise capacity, cardiac muscle irrigation, and blood supply to the body. Electrical and mechanical mappings of the myocardium before and after the therapy, and anatomopathological examination of the myocardium of one of the patients that had deceased of a stroke eleven months after the treatment indicated sustained neoangiogenesis and improvement of activity and quantity of cardiomyocytes in the injected regions. Post-hoc analyses of injected cell phenotype and improvement of myocardial function indicate that presence of CD8+ and CD56+ cells does not correlate with good prognostics, suggesting a possibility of cell selection. For 'no-option' severe cardiac patients, significant benefits of cell therapy and absence of adverse effects may justify the application of bone-marrow-derived cell therapy. To cite this article: H.F.R. Dohmann et al., C. R. Biologies 330 (2007).
Reestablishing feelings of control after experiencing uncertainty has long been considered a fund... more Reestablishing feelings of control after experiencing uncertainty has long been considered a fundamental motive for human behavior. We propose that rituals (i.e., socially stipulated, causally opaque practices) provide a means for coping with the aversive feelings associated with randomness due to the perception of a connection between ritual action and a desired outcome. Two experiments were conducted (one in Brazil [N = 40] and another in the U.S.
Rituals pose a cognitive paradox: although widely used to treat problems, rituals are causally op... more Rituals pose a cognitive paradox: although widely used to treat problems, rituals are causally opaque (i.e., they lack a causal explanation for their effects). How is the efficacy of ritual action evaluated in the absence of causal information? To examine this question using ecologically valid content, three studies (N = 162) were conducted in Brazil, a cultural context in which rituals called simpatias are used to treat a great variety of problems ranging from asthma to infidelity. Using content from existing simpatias, experimental simpatias were designed to manipulate the kinds of information that influences perceptions of efficacy. A fourth study (N = 68) with identical stimuli was conducted with a US sample to assess the generalizability of the findings across two different cultural contexts. The results provide evidence that information reflecting intuitive causal principles (i.e., repetition of procedures, number of procedural steps) and transcendental influence (i.e., presence of religious icons) affects how people evaluate ritual efficacy.
This text argues for higher Personal Income Tax levels. We show that, for all countries for which... more This text argues for higher Personal Income Tax levels. We show that, for all countries for which tax information is available, Brazil is the one in which Personal Income Tax collection as a percentage of the gross tax burden is the lowest. Personal Income Taxes account for about 6% of the Gross Tax Burden, slightly more than 2% of GDP, and slightly more than 4% of family income (according to the PNAD household survey). We show that this is due both to the fact that tax brackets are so high so as to exempt 85% of income ...
T Te ex xt to os s p pa ar ra a D Di is sc cu us ss sã ão o 207 TEXTO PARA DISCUSSÃO 207 • OUTUBR... more T Te ex xt to os s p pa ar ra a D Di is sc cu us ss sã ão o 207 TEXTO PARA DISCUSSÃO 207 • OUTUBRO DE 2009 • 1 Os artigos dos Textos para Discussão da Escola de Economia de São Paulo da Fundação Getulio Vargas são de inteira responsabilidade dos autores e não refletem necessariamente a opinião da FGV-EESP. É permitida a reprodução total ou parcial dos artigos, desde que creditada a fonte.
This study aimed at assessing the effects of autologous transendocardial transplantation of bone ... more This study aimed at assessing the effects of autologous transendocardial transplantation of bone marrow mononuclear cells (ATTBMMC) on symptoms, exercise capacity, myocardial perfusion and contractility in patients with severe ischemic heart disease during a 6-month follow-up period. This prospective study comprised 21 patients as follows: the first 14 patients forming the treated group, and the last 7 patients forming the control group. Initially, all patients underwent clinical and laboratory assessment, treadmill testing, echocardiography, myocardial scintigraphy, and 24-hour Holter. The bone marrow mononuclear cells (BMMC) were isolated, washed, and diluted in 0.9% saline solution for transendocardial injection in areas of viable myocardium in the treated group, (15 0.2-mL injections). All patients were reassessed in the end of 2 and 6 months of follow-up. The demographic data and other characteristics did not significantly differ between the groups in the initial evaluation. No...
This study aimed at assessing the effects of autologous transendocardial transplantation of bone ... more This study aimed at assessing the effects of autologous transendocardial transplantation of bone marrow mononuclear cells (ATTBMMC) on symptoms, exercise capacity, myocardial perfusion and contractility in patients with severe ischemic heart disease during a 6-month follow-up period.
Objective: Evaluate the effects of intracoronary autologous bone marrow mononuclear cells transpl... more Objective: Evaluate the effects of intracoronary autologous bone marrow mononuclear cells transplantation (ABMMCT) over left ventricle diastolic function (LVDF) by using Tissue Doppler imaging (TD) Echocardiography . Methods: Open label concealed randomized clinical trial. Nine pts (7 male), were submitted to successful percutaneous coronary intervention (PCI) for ST elevation acute myocardial infarction from the outlet of this study. Patients were
The pathway of electron transport to nitrogenase in the endophytic beta-Proteobacterium Herbaspir... more The pathway of electron transport to nitrogenase in the endophytic beta-Proteobacterium Herbaspirillum seropedicae has not been characterized. We have generated mutants in two nif-associated genes encoding putative ferredoxins, fdxA and fdxN. The fdxA gene is part of the operon nifHDKENXorf1orf2fdxAnifQmodABC and is transcribed from the nifH promoter, as revealed by lacZ gene fusion. The fdxN gene is probably cotranscribed with the nifB gene. Mutational analysis suggests that the FdxA protein is essential for maximum nitrogenase activity, since the nitrogenase activity of the fdxA mutant strain was reduced to about 30% of that of the wild-type strain. In addition, the fdxA mutation had no effect on the nitrogenase switch-off in response to ammonium. Nitrogenase activity of a mutant strain lacking the fdxN gene was completely abolished. This phenotype was reverted by complementation with fdxN expressed under lacZ promoter control. The results suggest that the products of both the fdxA and fdxN genes are probably involved in electron transfer during nitrogen fixation.
An analysis of a series of five peptides composed of various portions of the pleurocidin (Plc) se... more An analysis of a series of five peptides composed of various portions of the pleurocidin (Plc) sequence identified a l2-amino acid fragment from the C-terminus of Plc, designated Plc-2, as the smallest fragment that retained a antimicrobial activity comparable to that of the parent compound. MIC tests in vitro with low-ionic-strength medium showed that Plc-2 has potent activity against Pseudomonas aeruginosa, Escherichia coli and Staphylococcus aureus but not against Enterococcus faecalis. The antifungal activity of the synthetic peptides against phytopathogenic fungi, such as Fusarium oxysporum, Colletotrichum sp., Aspergillus niger and Alternaria sp., also identified Plc-2 as a biologically active peptide. Microscopy studies of fluorescently stained fungi treated with Plc-2 demonstrated that cytoplasmic and nuclear membranes were compromised in all strains of phytopathogenic fungi tested. Together, these results identify Plc-2 as a potential antimicrobial agent with similar properties to its parent compound, pleurocidin. In addition, it demonstrated that the KHVGKAALTHYL residues are critical for the antimicrobial activity described for pleurocidin.
We report an investigation for 16 bacteria and viruses among 184 children hospitalized with pneum... more We report an investigation for 16 bacteria and viruses among 184 children hospitalized with pneumonia in Salvador, Brazil. Etiology was established in 144 (78%) cases. Viral, bacterial, and mixed infections were found in 110 (60%), 77 (42%), and 52 (28%) patients, respectively. Rhinovirus (21%) and Streptococcus pneumoniae (21%) were the most common pathogens. Our results demonstrate the importance of viral and pneumococcal infections among those patients.
In this work we describe the ability of living Crithidia deanei to hydrolyze extracellular ATP. I... more In this work we describe the ability of living Crithidia deanei to hydrolyze extracellular ATP. In intact cells at pH 7.2, a low level of ATP hydrolysis was observed in the absence of any divalent metal (0.41+/-0.13 nmol P(i) h(-1) 10(7) cells(-1)). The ATP hydrolysis was stimulated by MgCl(2) and the Mg(2+)-dependent ecto-ATPase activity was 4.05+/-0.17 nmol P(i) h(-1) 10(7) cells(-1). Mg(2+)-dependent ecto-ATPase activity increased linearly with cell density and with time for at least 60 min. The addition of MgCl(2) to extracellular medium increased the ecto-ATPase activity in a dose-dependent manner. At 5 mM ATP, half-maximal stimulation of ATP hydrolysis was obtained with 0.93+/-0.26 mM MgCl(2). This stimulatory activity was also observed when MgCl(2) was replaced by MnCl(2), but not CaCl(2) or SrCl(2). The apparent K(m) for Mg-ATP(2-) was 0.26+/-0.03 mM. ATP was the best substrate for this enzyme; other nucleotides, such as ITP, GTP, UTP and CTP, produced lower reaction rates. In the pH range from 6.6 to 8.4, in which the cells were viable, the acid phosphatase activity also present in this cell decreased, while the Mg(2+)-dependent ATPase activity did not change. This ecto-ATPase activity was insensitive to inhibitors of other ATPase and phosphatase activities, such as oligomycin, sodium azide, bafilomycin A(1), ouabain, vanadate, molybdate, sodium fluoride and tartrate. To confirm that this Mg(2+)-dependent ATPase was an ecto-ATPase, we used the impermeant inhibitor 4, 4'-diisothiocyanostylbene 2'-2'-disulfonic acid as well as suramin, an antagonist of P(2) purinoreceptors and inhibitor of some ecto-ATPases. These two reagents inhibited the Mg(2+)-dependent ATPase activity in a dose-dependent manner. The cell surface location of the ATP-hydrolyzing site was also confirmed by cytochemical analysis.
Extracellular ATP (ATPo) is capable of inducing different events on cells through receptor activa... more Extracellular ATP (ATPo) is capable of inducing different events on cells through receptor activation. The effect produced by ATPo was studied in the cell line K562 and its multidrug resistant (MDR) counterpart, Lucena 1. Lower ATPo concentrations (1 mM and 2.5 mM) led to high (3)H-thymidine incorporation but no increase in cell number. Similarly, the cell cycle profile indicated an increase of cells in S phase and a decrease in G1 and G2, suggesting that the cells did not duplicate their DNA content. Higher doses of ATP (5 mM and 10 mM), as well as UTP (5 mM) and the P2X(7) agonist BzATP, were cytotoxic. However, no expression of P2X(7) receptors could be detected by Western Blot nor were the cells permeabilised by ATP, suggesting that pore formation was not involved in cell death. Both ecto-ATPase and ecto-5'-nucleotidase activity could be demonstrated at the surfaces of K562 and Lucena 1 cells, the latter presenting a higher ecto-5'-nucleotidase activity. Adenosine induced cell death at lower concentrations (2.5 mM) on both cell lines. Furthermore, an increased number of dead cells could be observed when 5 mM Adenosine was used compared to the same concentrations of ATPo. It still remains to be elucidated the nature of the receptors involved in the induction of cell death in these cells.
The four dominant outer membrane proteins (46, 38, 33 and 28 kDa) were detected by sodium dodecyl... more The four dominant outer membrane proteins (46, 38, 33 and 28 kDa) were detected by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) in a semi-purified preparation of vesicle membranes of a Neisseria meningitidis (N44/89, B:4:P1.15:P5.5,7) strain isolated in Brazil. The Nterminal amino acid sequence for the 46 kDa and 28 kDa proteins matched that reported by others for class 1 and 5 proteins respectively, whereas the sequence (25 amino acids) for the 38 kDa (class 3) protein was similar to class 1 meningococcal proteins. The sequence for the 33 kDa (class 4) was unique and not homologous to any known protein.
The objective of this work was to evaluate the technical feasibility of coupling two membrane sep... more The objective of this work was to evaluate the technical feasibility of coupling two membrane separation processes, reverse osmosis (RO) and osmotic evaporation (OE), in order to concentrate clarified camu-camu juice, focusing on the vitamin C, phenolic compounds and antioxidant activity of the final product. The juice was firstly pre-concentrated by RO, reaching 285 g kg À1 of soluble solids. During this step, the juice's osmotic pressure showed to be the main factor controlling mass transfer. The juice was then concentrated by OE, reaching 530 g kg À1 of soluble solids. Vitamin C, total phenolics and antioxidant activity levels of 94.6 g ascorbic acid kg À1 , 105.2 g galic acid kg À1 and 762 mmol Trolox kg À1 , respectively, were achieved in the final product. The use of integrated membrane processes proved to be an interesting alternative to the concentration of thermosensitive juices, reaching concentration levels up to 7 times for camu-camu juice's bioactive compounds.
In prokaryotes molybdenum is taken up by a high-affinity ABC-type transporter system encoded by t... more In prokaryotes molybdenum is taken up by a high-affinity ABC-type transporter system encoded by the modABC genes. The endophyte β-Proteobacterium Herbaspirillum seropedicae has two modABC gene clusters and two genes encoding putative Mo-dependent regulator proteins (ModE1 and ModE2). Analysis of the amino acid sequence of the ModE1 protein of H. seropedicae revealed the presence of an N-terminal domain containing a DNA-binding helix-turn-helix motif (HTH) and a C-terminal domain with a molybdate-binding motif. The second putative regulator protein, ModE2, contains only the helix-turn-helix motif, similar to that observed in some sequenced genomes. We cloned the modE1 (810 bp) and modE2 (372 bp) genes and expressed them in Escherichia coli as His-tagged fusion proteins, which we subsequently purified. The over-expressed recombinant His-ModE1 was insoluble and was purified after solubilization with urea and then on-column refolded during affinity chromatography. The His-ModE2 was expressed as a soluble protein and purified by affinity chromatography. These purified proteins were analyzed by DNA band-shift assays using the modA2 promoter region as probe. Our results indicate that His-ModE1 and His-ModE2 are able to bind to the modA2 promoter region, suggesting that both proteins may play a role in the regulation of molybdenum uptake and metabolism in H. seropedicae.
Adults and young children prefer to affiliate with some individuals rather than others. Studies h... more Adults and young children prefer to affiliate with some individuals rather than others. Studies have shown that monolingual children show in-group biases for individuals who speak their native language without a foreign accent . Some studies have suggested that bilingual children are less influenced than monolinguals by language variety when attributing personality traits to different speakers , which could indicate that bilinguals have fewer in-group biases and perhaps greater social flexibility. However, no previous studies have compared monolingual and bilingual children's reactions to speakers with unfamiliar foreign accents. In the present study, we investigated the social preferences of 5-year-old English and French monolinguals and English-French bilinguals. Contrary to our predictions, both monolingual and bilingual preschoolers preferred to be friends with native-accented speakers over speakers who spoke their dominant language with an unfamiliar foreign accent. This result suggests that both monolingual and bilingual children have strong preferences for in-group members who use a familiar language variety, and that bilingualism does not lead to generalized social flexibility.
In this work we describe the ability of living Trypanosoma rangeli to hydrolyze extracellular ATP... more In this work we describe the ability of living Trypanosoma rangeli to hydrolyze extracellular ATP. In these intact parasites whose viability was assessed before and after the reactions by motility and by Trypan blue dye exclusion, there was a low level of ATP hydrolysis in the absence of any divalent metal (1.53 § 0.12 nmol Pi/h £ 10 7 cells). The ATP hydrolysis was stimulated by MgCl 2 and the Mg-dependent ecto-ATPase activity was 5.24 § 0.64 nmol Pi/h £ 10 7 cells. The Mg-dependent ecto-ATPase activity was linear with cell density and with time for at least 60 min. This stimulatory eVect on the ATP hydrolysis was also observed when MgCl 2 was replaced by MnCl 2 , but not by CaCl 2 , SrCl 2 , and ZnCl 2 . The apparent K m for Mg-ATP2-was 0.53 § 0.11 mM. The optimum pH for the T. rangeli Mg-dependent ecto-ATPase activity lies in the alkaline range. This ecto-ATPase activity was insensitive to inhibitors of other ATPase and phosphatase activities, such as oligomycin, sodium azide, baWlomycin A1, ouabain, furosemide, vanadate, molybdate, sodium Xuoride, tartrate, and levamizole. To conWrm that this Mg-dependent ATPase was an ecto-ATPase, we used an impermeant inhibitor, DIDS (4, 4Ј-diisothiocyanostylbene 2Ј-2Ј-disulfonic acid) as well as suramin, an antagonist of P2 purinoreceptors and inhibitor of some ecto-ATPases. These two reagents inhibited the Mg 2+ -dependent ATPase activity in a dose-dependent manner. This ecto-ATPase activity was stimulated by carbohydrates involved in the attachment/invasion of salivary glands of Rhodnius prolixus and by lipophorin, an insect lipoprotein circulating in the hemolymph.
The presence of Leishmania amazonensis ecto-nucleoside triphosphate triphosphohydrolase activitie... more The presence of Leishmania amazonensis ecto-nucleoside triphosphate triphosphohydrolase activities was demonstrated using antibodies against diVerent NTPDase members by Western blotting, Xow cytometry, and immunoelectron microscopy analysis. Living promastigote cells sequentially hydrolyzed the ATP molecule generating ADP, AMP, and adenosine, indicating that this surface enzyme may play a role in the salvage of purines from the extracellular medium. The L. amazonensis ecto-NTPDase activities were insensitive to Triton X-100, but they were enhanced by divalent cations, such as Mg 2+ . In addition, the ecto-NTPDase activities decreased with time for 96 h when promastigotes were grown in vitro. On the other hand, these activities increased considerably when measured in living amastigote forms. Furthermore, the treatment with adenosine, a mediator of several relevant biological phenomena, induced a decrease in the reactivity with anti-CD39 antibody, raised against mammalian E-NTPDase, probably because of down regulation in the L. amazonensis ecto-NTPDase expression. Also, adenosine and anti-NTPDase antibodies induced a signiWcant diminishing in the interaction between promastigotes of L. amazonensis and mouse peritoneal macrophages.
Trypanosoma rangeli is a parasite of a numerous wild and domestic animals, presenting wide geogra... more Trypanosoma rangeli is a parasite of a numerous wild and domestic animals, presenting wide geographical distribution and high immunological cross-reactivity with Trypanosoma cruzi, which may lead to misdiagnosis. T. rangeli has a complex life cycle, involving distinct morphological and functional forms in the vector. Here, we characterized the cell surface polypeptides and the phosphatase activities in short and long epimastigotes forms of T. rangeli, using intact living parasites. The surface protein proWle revealed by the incubation of parasites with biotin showed a preferential expression of the 97, 70, 50, 45, 25-22, and 15 kDa biotinylated polypeptides in the long forms, in contrast to the 55 and 28 kDa biotinylated polypeptides synthesized by the short epimastigotes. Additionally, Xow cytometry analysis showed that the short forms had relatively lower biotin surface binding than long ones. The involvement of phosphatases with the trypanosomatid diVerentiation has been proposed. In this sense, T. rangeli living parasites were able to hydrolyze the artiWcial substrate p-nitrophenylphosphate at a rate of 25.57 § 2.03 and 10.09 § 0.93 nmol p-NPP £ h ¡1 £ 10 7 cells for the short and long epimastigotes, respectively. These phosphatase activities were linear with time for at least 60 min and the optimum pH lies in the acid range. Classical inhibitors of acid phosphatases, such as ammonium molybdate, sodium Xuoride, and zinc chloride, showed a signiWcant decrease in these phosphatase activities, with diVerent patterns of inhibition. Additionally, these phosphatase activities presented diVerent kinetic parameters (K m and V max ) and distinct sensitivities to divalent cations. Both epimastigotes were unable to release phosphatase to the extracellular environment. Cytochemical analysis demonstrated the localization of these enzymes on the parasite surfaces (cell body and Xagellum) and in intracellular vacuoles, resembling acidocalcisomes.
We describe cell therapy for severe ischemic heart failure using transendocardial injection of au... more We describe cell therapy for severe ischemic heart failure using transendocardial injection of autologous bone-marrow-derived mononuclear cells. The treated patients had significantly less heart failure and angina, sustained significant improvement of pumping power, exercise capacity, cardiac muscle irrigation, and blood supply to the body. Electrical and mechanical mappings of the myocardium before and after the therapy, and anatomopathological examination of the myocardium of one of the patients that had deceased of a stroke eleven months after the treatment indicated sustained neoangiogenesis and improvement of activity and quantity of cardiomyocytes in the injected regions. Post-hoc analyses of injected cell phenotype and improvement of myocardial function indicate that presence of CD8+ and CD56+ cells does not correlate with good prognostics, suggesting a possibility of cell selection. For 'no-option' severe cardiac patients, significant benefits of cell therapy and absence of adverse effects may justify the application of bone-marrow-derived cell therapy. To cite this article: H.F.R. Dohmann et al., C. R. Biologies 330 (2007).
Reestablishing feelings of control after experiencing uncertainty has long been considered a fund... more Reestablishing feelings of control after experiencing uncertainty has long been considered a fundamental motive for human behavior. We propose that rituals (i.e., socially stipulated, causally opaque practices) provide a means for coping with the aversive feelings associated with randomness due to the perception of a connection between ritual action and a desired outcome. Two experiments were conducted (one in Brazil [N = 40] and another in the U.S.
Rituals pose a cognitive paradox: although widely used to treat problems, rituals are causally op... more Rituals pose a cognitive paradox: although widely used to treat problems, rituals are causally opaque (i.e., they lack a causal explanation for their effects). How is the efficacy of ritual action evaluated in the absence of causal information? To examine this question using ecologically valid content, three studies (N = 162) were conducted in Brazil, a cultural context in which rituals called simpatias are used to treat a great variety of problems ranging from asthma to infidelity. Using content from existing simpatias, experimental simpatias were designed to manipulate the kinds of information that influences perceptions of efficacy. A fourth study (N = 68) with identical stimuli was conducted with a US sample to assess the generalizability of the findings across two different cultural contexts. The results provide evidence that information reflecting intuitive causal principles (i.e., repetition of procedures, number of procedural steps) and transcendental influence (i.e., presence of religious icons) affects how people evaluate ritual efficacy.
This text argues for higher Personal Income Tax levels. We show that, for all countries for which... more This text argues for higher Personal Income Tax levels. We show that, for all countries for which tax information is available, Brazil is the one in which Personal Income Tax collection as a percentage of the gross tax burden is the lowest. Personal Income Taxes account for about 6% of the Gross Tax Burden, slightly more than 2% of GDP, and slightly more than 4% of family income (according to the PNAD household survey). We show that this is due both to the fact that tax brackets are so high so as to exempt 85% of income ...
T Te ex xt to os s p pa ar ra a D Di is sc cu us ss sã ão o 207 TEXTO PARA DISCUSSÃO 207 • OUTUBR... more T Te ex xt to os s p pa ar ra a D Di is sc cu us ss sã ão o 207 TEXTO PARA DISCUSSÃO 207 • OUTUBRO DE 2009 • 1 Os artigos dos Textos para Discussão da Escola de Economia de São Paulo da Fundação Getulio Vargas são de inteira responsabilidade dos autores e não refletem necessariamente a opinião da FGV-EESP. É permitida a reprodução total ou parcial dos artigos, desde que creditada a fonte.
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