1,258 research outputs found
Percepções de consumidores sobre carne bovina com indicação geográfica de raças locais brasileiras, Campo Grande-MS.
Foi realizado levantamento com 347 consumidores de carne bovina em 12 estabelecimentos que comercializam carnes em Campo Grande (MS), a fim de identificar sua percepção com relação à s carnes diferenciadas, especialmente identificação geográfica (IG), buscando entender como essa percepção pode ser utilizada como estratégia para conservação de raças locais, como o bovino Pantaneiro e o bovino Curraleiro Pé-Duro, e identificar se estão dispostos a pagar por estes atributos. Os dados foram obtidos por meio de entre vistas verbais utilizando um questionário semiestruturado composto por questões fechadas e abertas, subdividido em duas partes, uma referente ao perfil do consumidor e outra sobre seu conhecimento das caracterÃsticas de carnes com indicação geográfica e das raças bovinas locais. Constatou-se que a maioria dos consumidores tem pouco conhecimento sobre o que são carnes com indicação geográfica e o que são raças bovinas locais. Mesmo assim, demonstraram interesse em consumir carne com IG de raças locais caso essas caracterÃsticas sejam um indicador de qualidade e também para incentivar e valorizar um produto local. Além disso, estão dispostos a pagar mais por este tipo de produto, embora a frequência de consumo vá depender do preço . Conclui-se que o consumidor valorizou os atributos desse tipo de carne, sendo possÃvel agregar valor em função de tais diferenciais. Desta forma, o uso de IG e m raças locais pode contribuir para a conservação dessas raças ao incorporar sua carne ao mercado
Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry for Differentiation of the Dimorphic Fungal Species Paracoccidioides brasiliensis and Paracoccidioides lutzii
Isolates of Paracoccidioides brasiliensis and Paracoccidioides lutzii, previously characterized by molecular techniques, were identified for the first time by matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS). All isolates were correctly identified, with log score values of >2.0. Thus, MALDI-TOF MS is a new tool for differentiating species of the genus Paracoccidioides.Univ São Paulo, Fac Med, Hosp Clin, Cent Lab Div LIM03, São Paulo, BrazilUniv São Paulo, Inst Med Trop, Hosp Clin FMUSP, Lab Med Mycol LIM53, São Paulo, BrazilUniv São Paulo, Dept Biophys, Escola Paulista Med, São Paulo, BrazilUniv Estadual Paulista, Dept Microbiol & Immunol, Inst Biociencias Botucatu, Botucatu, SP, BrazilUniv São Paulo, Dept Biophys, Escola Paulista Med, São Paulo, BrazilWeb of Scienc
Providing heat-stress abatement to late-lactation Holstein cows affects hormones, metabolite blood profiles, and hepatic gene expression but not productive responses
Objective: Our objective was to evaluate the effects of providing shade and shade combined with evaporative cooling on production, cow activity, metabolism, and hepatic gene expression of late-lactation Holstein dairy cows under moderate heat-stress conditions. Materials and Methods: Forty-eight multiparous Holstein cows were used in a completely randomized block-design trial and randomly assigned to 1 of 3 treatments: control (CTL), without access to shade; access to artificial shade (SH); and shade combined with evaporative cooling (SHplus). Results were analyzed using a mixed procedure with repeated measures. Results and Discussion: No differences were observed in DMI. Milk yield was not different among treatments, but lactose concentration was greater in SHplus. Treatments CTL and SH had greater BW losses than SHplus. Control cows spent less time grazing. The CTL and SH had higher p.m. rectal temperatures than SHplus, whereas CTL had the highest p.m. respiration rate. Control cows had greater serum insulin levels. Control and SH had greater BHB and urea concentrations and lower glucose concentration compared with SHplus. The hepatic expression of PCK1, PDK4, and HP genes was downregulated in SH and SHplus relative to control. Hepatic expression of NFKB1 was downregulated, whereas SOCS2 was upregulated, for SHplus compared with CTL. Implications and Applications: Despite the absence of treatment effects on productive variables, changes in blood profiles and hepatic expression of target genes were observed among treatments. These results suggest that the provision of shade combined with evaporative cooling was effective in alleviating the negative effects of heat stress.Fil: MartÃnez, RocÃo Soledad. Instituto Nacional de Investigacion Agropecuaria;Fil: Palladino, Rafael Alejandro. Universidad Nacional de Lomas de Zamora; Argentina. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Unidad Ejecutora de Investigaciones en Producción Animal. Universidad de Buenos Aires. Facultad de Ciencias Veterinarias. Unidad Ejecutora de Investigaciones en Producción Animal; ArgentinaFil: Banchero, Georgget. Instituto Nacional de Investigacion Agropecuaria;Fil: Fernández y MartÃn, Rafael. Universidad de Buenos Aires. Facultad de AgronomÃa; Argentina. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Unidad Ejecutora de Investigaciones en Producción Animal. Universidad de Buenos Aires. Facultad de Ciencias Veterinarias. Unidad Ejecutora de Investigaciones en Producción Animal; ArgentinaFil: Nanni, Mariana Sandra. Instituto Nacional de TecnologÃa Agropecuaria. Centro de Investigación de Agroindustria. Instituto de TecnologÃa de los Alimentos; Argentina. Consejo Nacional de Investigaciones CientÃficas y Técnicas; ArgentinaFil: Juliano, Nicolas. Universidad de Buenos Aires. Facultad de AgronomÃa; Argentina. Consejo Nacional de Investigaciones CientÃficas y Técnicas; ArgentinaFil: Iorio, Jesica Daniela. Universidad de Buenos Aires. Facultad de AgronomÃa; ArgentinaFil: La Manna, Alejandro. Instituto Nacional de Investigacion Agropecuaria
Role of DLC-1, a tumor suppressor protein with RhoGAP activity, in regulation of the cytoskeleton and cell motility
DLC-1 was originally identified as a potential tumor suppressor. One of the key biochemical functions of DLC-1 is to serve as a GTPase activating protein (GAP) for members of the Rho family of GTPases, particularly Rho A-C and Cdc 42. Since these GTPases are critically involved in regulation of the cytoskeleton and cell migration, it seems clear that DLC-1 will also influence these processes. In this review we examine basic aspects of the actin cyoskeleton and how it relates to cell motility. We then delineate the characteristics of DLC-1 and other members of its family, and describe how they may have multiple effects on the regulation of cell polarity, actin organization, and cell migration
Regulatory CD8 T cells that recognize Qa-1 expressed by CD4 T-helper cells inhibit rejection of heart allografts
Induction of longstanding immunologic tolerance is essential for survival of transplanted organs and tissues. Despite recent advances in immunosuppression protocols, allograft damage inflicted by antibody specific for donor organs continues to represent a major obstacle to graft survival. Here we report that activation of regulatory CD8 T cells (CD8 Treg) that recognize the Qa-1 class Ib major histocompatibility complex (MHC), a mouse homolog of human leukocyte antigen-E (HLA-E), inhibits antibody-mediated immune rejection of heart allografts. We analyzed this response using a mouse model that harbors a point mutation in the class Ib MHC molecule Qa-1, which disrupts Qa-1 binding to the T cell receptor (TCR)-CD8 complex and impairs the CD8 Treg response. Despite administration of cytotoxic T lymphocyte antigen 4 (CTLA-4) immunoglobulin (Ig), Qa-1 mutant mice developed robust donor-specific antibody responses and accelerated heart graft rejection. We show that these allo-antibody responses reflect diminished Qa-1-restricted CD8 Treg-mediated suppression of host follicular helper T cell-dependent antibody production. These findings underscore the critical contribution of this Qa-1/HLA-E-dependent regulatory pathway to maintenance of transplanted organs and suggest therapeutic approaches to ameliorate allograft rejection
Preoperative evaluation of cytologically indeterminate thyroid nodules with 18F-FDG PET
Esse artigo tem o objetivo de discutir o papel da tomografia por emissão de pósitrons (PET) com 18F-FDG na avaliação pré-operatória de pacientes com nódulos de tireóide com citologia indeterminada. Para o cálculo da sensibilidade, foram selecionados todos os estudos com pacientes com carcinoma de tireóide. Para o cálculo da especificidade, foram selecionados apenas estudos desenhados para avaliação dos pacientes com nódulos com citologia indeterminada. O achado de captação focal na PET-18F-FDG relacionou-se com a presença de carcinoma de tireóide na maioria dos estudos. A sensibilidade do exame foi bastante alta na detecção de malignidade tireoidiana, porém sua especificidade variou de 0% a 66%, sendo de 39% em estudo brasileiro. Concluindo, os estudos indicam que a PET-18F-FDG pode reduzir o número de tireoidectomias desnecessárias em pacientes com nódulos de tireóide com citologia indeterminada. Entretanto, o percentual relativamente elevado de resultados falso-positivos, o alto custo, a baixa disponibilidade do exame em paÃses em desenvolvimento e a pouca experiência clÃnica ainda limitam o uso da PET-18F-FDG com essa finalidade.The aim of this article is to discuss the role of 18F-FDG Positron Emission Tomography (PET) in the preoperative evaluation of patients with cytologically indeterminate thyroid nodules. All studies with patients with thyroid cancer were selected to the calculation of sensitivity. Only studies aiming to evaluate patients with thyroid nodules whose cytological result was indeterminate were selected to establish the specificity. The finding of focal 18F-FDG uptake at PET was associated with the presence of thyroid malignancy in most of the studies. The sensitivity of the exam to the detection of thyroid malignancy was extremely high, but the specificity varied from 0 to 66%. In our experience, the specificity was 39%. In conclusion, the studies suggest that 18F-FDG PET can reduce the number of unnecessary thyroidectomies performed in patients with cytologically indeterminate thyroid nodules. However, the relatively high percentage of false positive results, the high costs, the low availability of this exam in developing countries and the low clinical experience still restrict the use of 18F-FDG PET when recommended with this aim
Hysteretic Behavior of Proprotein Convertase 1/3 (PC1/3)
The proprotein convertases (PCs) are calcium-dependent proteases responsible for processing precursor proteins into their active forms in eukariotes. The PC1/3 is a pivotal enzyme of this family that participates in the proteolytic maturation of prohormones and neuropeptides inside the regulated secretory pathway. In this paper we demonstrate that mouse proprotein convertase 1/3 (mPC1/3) has a lag phase of activation by substrates that can be interpreted as a hysteretic behavior of the enzyme for their hydrolysis. This is an unprecedented observation in peptidases, but is frequent in regulatory enzymes with physiological relevance. The lag phase of mPC1/3 is dependent on substrate, calcium concentration and pH. This hysteretic behavior may have implications in the physiological processes in which PC1/3 participates and could be considered an additional control step in the peptide hormone maturation processes as for instance in the transformation of proinsulin to insulin
Structural features that make oligopeptides susceptible substrates for hydrolysis by recombinant thimet oligopeptidase
A systematic analysis of the peptide sequences and lengths of several homologues of bioactive peptides and of a number of quenched-fluorescence (qf) opioid- and bradykinin-related peptides was performed to determine the main features leading the oligopeptides to hydrolysis by the recombinant rat testis thimet oligopeptidase (EC 3.4.24.15). The results indicate that a minimum substrate length of six amino acids is required and that among the oligopeptides six to thirteen amino acid residues long, their susceptibility as substrates is highly variable. Thimet oligopeptidase was able to hydrolyse, with similar catalytic efficiency, peptide bonds having hydrophobic or hydrophilic amino acids as well as proline in the P1 position of peptides, ranging from a minimum of six to a maximum of approximately thirteen amino acid residues. An intriguing observation was the shift of the cleavage site, at a Leu-Arg bond in qf dynorphin (2-8) [qf-Dyn(2-8); Abz-GGFLRRV-EDDnp, where Abz stands for o-aminobenzoyl and EDDnp for N-(2,4-dinitrophenyl) ethylenediamine], to Arg-Arg in qf-Dyn(2-8)Q, in which Gln was substituted for Val at its C-terminus. Similarly, a cleavage site displacement was also observed with the hydrolysis of the internally quenched-fluorescence bradykinin analogues containing Gin at the C-terminal position, namely Abz-RPPGFSPFR-EDDnp and Abz-GFSPFR-EDDnp are cleaved at the Phe-Ser bond, but Abz-RPPGFSPFRQ-EDDnp and Abz-GFSPFRQ-EDDnp are cleaved at the Pro-Phe bond.UNIV FED SAO PAULO,ESCOLA PAULISTA MED,DEPT BIOFIS,BR-04044020 SAO PAULO,SP,BRAZILINST BUTANTAN,BIOCHEM & BIOPHYS LAB,BR-05503900 SAO PAULO,BRAZILUNIV SAO PAULO,INST BIOMED SCI,SAO PAULO,BRAZILFDN ANTONIO PRUDENTE,BR-01509010 SAO PAULO,BRAZILUNIV FED SAO PAULO,ESCOLA PAULISTA MED,DEPT BIOFIS,BR-04044020 SAO PAULO,SP,BRAZILWeb of Scienc
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