869 research outputs found
In vitro amplification of BVDV field strains isolated in Argentina: effect of cell line and culture conditions
The aim of this work was to study the in vitro amplification of BVDV (Pestivirus, Flaviridae) field isolates from Argentina in MDBK, BoTur and BHK-21 continuous cell lines. Field isolates 99/134 (mucosal disease), 00/693 (mucosal disease), 04P7016 (respiratory disease) and 04/89 (mucosal disease), genotype 1b, were used and compared with the Singer and NADL reference strains, genotype 1a. Additionally, cell lines derived from explants of bovine testis (RD-420), bovine uterus (NCL-1) and porcine kidney (PKZ) were tested as alternative substrates for BVDV propagation in vitro. The effect of cell line, harvest time and infection protocol was evaluated. The viral titers observed depended on the virus and harvest time but not on the infection protocol. We found that MDBK and BoTur cell lines were susceptible to the infection whereas BHK-21 and PKZ were not. NADL viral titers, 00/693 and 04/89, increased from 24 to 48 h p.i. in BoTur cells and then reached a plateau, whereas those of 99/134 and 04P7016 remained constant between 24 and 72 h p.i. BVDV Singer, on the other hand, presented a maximum titer at 24 h p.i. and then decreased. BVDV-NADL titers increased in MDBK and NCL-1 but not in RD-420 between 24 and 48 h p.i., and then decreased at 72 h p.i. These facts lead us to conclude that neither the subgenotypes (1a, 1b) nor the clinical symptoms of the animal from the virus had been isolated seem to affect the virus cell line kinetics of viral replication in vitro. On the other hand, the most homogenous behavior, the most similar replication curves, and highest titers observed in MDBK and NCL-1 seem to indicate that these lines are generally more susceptible to BVDV replication.The aim of this work was to study the in vitro amplification of BVDV (Pestivirus, Flaviridae) field isolates from Argentina in MDBK, BoTur and BHK-21 continuous cell lines. Field isolates 99/134 (mucosal disease), 00/693 (mucosal disease), 04P7016 (respiratory disease) and 04/89 (mucosal disease), genotype 1b, were used and compared with the Singer and NADL reference strains, genotype 1a. Additionally, cell lines derived from explants of bovine testis (RD420), bovine uterus (NCL-1) and porcine kidney (PKZ) were tested as alternative substrates for BVDV propagation in vitro. The effect of cell line, harvest time and infection protocol was evaluated. The viral titers observed depended on the virus and harvest time but not on the infection protocol. We found that MDBK and BoTur cell lines were susceptible to the infection whereas BHK-21 and PKZ were not. NADL viral titers, 00/693 and 04/89, increased from 24 to 48 h p.i. in BoTur cells and then reached a plateau, whereas those of 99/134 and 04P7016 remained constant between 24 and 72 h p.i. BVDV Singer, on the other hand, presented a maximum titer at 24 h p.i. and then decreased. BVDV-NADL titers increased in MDBK and NCL-1 but not in RD-420 between 24 and 48 h p.i., and then decreased at 72 h p.i. These facts lead us to conclude that neither the subgenotypes (1a, 1b) nor the clinical symptoms of the animal from the virus had been isolated seem to affect the virus cell line kinetics of viral replication in vitro. On the other hand, the most homogenous behavior, the most similar replication curves, and highest titers observed in MDBK and NCL-1 seem to indicate that these lines are generally more susceptible to BVDV replication.Fil: Odeón, Anselmo Carlos. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires Sur. Estación Experimental Agropecuaria Balcarce; ArgentinaFil: Leunda, Maria Rosa. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires Sur. Estación Experimental Agropecuaria Balcarce; ArgentinaFil: Faverin, Claudia. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires Sur. Estación Experimental Agropecuaria Balcarce; ArgentinaFil: Boynak, Natalia. Universidad Nacional de Mar del Plata; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; ArgentinaFil: Vena, M. M.. Biogénesis-Bagó S. A.; ArgentinaFil: Zabal, O.. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Virología; Argentin
Argentinean agid test for diagnosis of equine infectious anemia: six years of history
Equine infectious anemia (EIA) is a disease of high economic impact on the equine industry worldwide. Since horses are frequent travelers, EIA falls under strict regulatory control programs in many countries. In Argentina the national animal health authority (SENASA) states that all horses imported, moving within the country, or congregating at public assemblies must have a negative EIA report conducted within the previous 2 months. The agent causing EIA is a RNA virus from the Retroviridae family and its major capsid protein named p26 is the most immunogenic protein in the viral particle. Thus, the detection of specific antibodies directed to p26 is the aim of most diagnosis tests available in the world. The agar gel immunodifusion (AGID) is the officially accepted method to certify the diagnosis of EIA in Argentina. Since 2009 IncuINTA was working on the scaling up and production of the KIT AIE IDGA RP26, an Argentinean AGID test entirely developed in the laboratory containing a recombinant p26 protein to detect EIA antibodies in horses’ serum. Until 2015 IncuINTA produced two pilot batches and six commercial batches (one per year) containing from 24000 determinations in 2011 to 39600 determinations in 2015. Since the product was launched in 2011, the sales were increased 109%. Up to date we have placed on the market 170640 determinations. As expected, the number of laboratories buying the KIT AIE IDGA RP26 was also increasing through time being 26 in 2011 and 36 in 2015. This number of clients represents 17% of the 207 laboratories authorized by SENASA to diagnose EIA in Argentina. These laboratories are located mostly in Buenos Aires, Santa Fe, Entre Ríos, Formosa, La Pampa, Rio Negro, Cordoba, Corrientes, Salta and Tucum an provinces. Until 2009 there was no Argentinean EIA test available in our market being the imported ones very expensive. IncuINTA, which is a R&D laboratory, could scale up, produce and sell the KIT AIE IDGA RP26 during six consecutive years. After this success, IncuINTA perspective is to increase the number of batches each year to be able to attend the demand of most diagnosis laboratories in the country.Fil: Bok, Marina. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Virología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Asenzo, G.. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Virología; ArgentinaFil: Vena, M. M.. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Virología; ArgentinaFil: Parreño, V.. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Virología; ArgentinaFil: Wigdorovitz, A.. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Virología; Argentina10th International Equine Infectious Diseases ConferenceBuenos AiresArgentinaUniversity of Kentuck
Modeling the collagen fibril network of biological tissues as a nonlinearly elastic material using a continuous volume fraction distribution function
Despite distinct mechanical functions, biological soft tissues have a common microstructure in which a ground matrix is reinforced by a collagen fibril network. The microstructural properties of the collagen network contribute to continuum mechanical tissue properties that are strongly anisotropic with tensile-compressive asymmetry. In this study, a novel approach based on a continuous distribution of collagen fibril volume fractions is developed to model fibril reinforced soft tissues as nonlinearly elastic and anisotropic material. Compared with other approaches that use a normalized number of fibrils for the definition of the distribution function, this representation is based on a distribution parameter (i.e. volume fraction) that is commonly measured experimentally while also incorporating pre-stress of the collagen fibril network in a tissue natural configuration. After motivating the form of the collagen strain energy function, examples are provided for two volume fraction distribution functions. Consequently, collagen second-Piola Kirchhoff stress and elasticity tensors are derived, first in general form and then specifically for a model that may be used for immature bovine articular cartilage. It is shown that the proposed strain energy is a convex function of the deformation gradient tensor and, thus, is suitable for the formation of a polyconvex tissue strain energy function
RF and THz Identification Using a New Generation of Chipless RFID Tags
This article presents two chipless RFID approaches where data are reading using electromagnetic waves and where the medium encoding the data is completely passive. The former approach rests on the use of RF waves (more precisely the ultra-wide band UWB). The tags developed for this application are comparable with very specific, planar, conductive, radar targets where the relation between the tag geometry and its electromagnetic signature is perfectly known and is used to encode the data. The principle of operation as well as the realization process of the RF tags presented in this paper is similar to those already reported in the literature. However, contrary to the majority of chipless RFID tags, these labels do not present an antenna function dissociated from the circuit part where the data are stored. Here, functions such as the receiver, the treatment and the emitter of the signal are closely dependent. The data storage capacity of the RF chipless tags is proportional to of the used frequency bandwidth. As radio spectrum is regulated, the number of possible encoding bits is thus strongly limited with this technology. This is the reason why we introduce a new family of tags radically different from the preceding one, where data is encoded in volume thanks to a multilayer structure operating in the THz domain. These two approaches although different are complementary and allow to increase significantly the data storage capacity of the chipless tags. Simulation and experimental results are reported in this paper for both configurations. We demonstrate a coding capacity of 3.3 bit/cm2 for RFID chipless tags and a potential 10 bits coding capacity in the THz domain
once weekly administration of high dosage etanercept in patients with plaque psoriasis results of a pilot experience power study
Abstract Etanercept is a soluble tumour necrosis factor receptor fusion protein which is approved for the treatment of plaque psoriasis at the dose of either 25mg twice weekly (BIW) or, for the initial 12 weeks, 50mg BIW. Alternative dosing regimens have not been evaluated in psoriasis. In this study, we compare the efficacy and tolerability of two etanercept dosing regimens--50mg BIW and 100mg once weekly (OW)--for 12 weeks in 108 patients with moderate-to-severe recalcitrant psoriasis. Efficacy measures included Psoriasis Area and Severity Index (PASI), severity of pruritus recorded on a visual analogue scale (VAS) and the influence on quality of life assessed by means of Dermatology Life Quality Index (DLQI). Both etanercept regimens caused a significant change in all the efficacy parameters after 4 weeks and 12 weeks, at a comparable rate. At week 12, a PASI improvement of at least 50% from baseline (PASI 50) was achieved by 74% of patients treated with 50mg BIW and 78% of patients treated with 100mg OW. A PASI 75 response was obtained in 54% and 50% of patients treated with 50mg BIW and 100mg OW, respectively. Treatment was well tolerated with similar type and frequency of adverse events between the two groups
Communicating serum chemical concentrations to study participants: follow up survey
<p>Abstract</p> <p>Background</p> <p>A considerable literature now supports the importance of effective communication with study participants, including how best to develop communication plans focusing on the uncertainty of health risks associated with particular environmental exposures. Strategies for communicating individual concentrations of environmental chemicals in human biological samples in the absence of clearly established safe or hazardous levels have been discussed from a conceptual basis and to a lesser extent from an empirical basis. We designed and evaluated an empirically based communication strategy for women of reproductive age who previously participated in a prospective study focusing on persistent environmental chemicals and reproductive outcomes.</p> <p>Methods</p> <p>A cohort of women followed from preconception through pregnancy or up to 12 menstrual cycles without pregnancy was given their individual serum concentrations for lead, dichloro-2,2-bis<it>p</it>-chlorophenyl ethylene, and select polychlorinated biphenyl congeners. Two versions of standardized letters were prepared depending upon women's exposure status, which was characterized as low or high. Letters included an introduction, individual concentrations, population reference values and guidance for minimizing future exposures. Participants were actively monitored for any questions or concerns following receipt of letters.</p> <p>Results</p> <p>Ninety-eight women were sent letters informing them of their individual concentrations to select study chemicals. None of the 89 (91%) participating women irrespective of exposure status contacted the research team with questions or concerns about communicated exposures despite an invitation to do so.</p> <p>Conclusions</p> <p>Our findings suggest that study participants can be informed about their individual serum concentrations without generating unnecessary concern.</p
Does Oxidative Stress Play a Role in the Pathogenesis of Urticarias
Radical oxygen species (ROS) modulate various cellular processes and are involved in physiologic and pathologic conditions, including inflammation. There is growing evidence that supports the existence of an abnormal redox status in some chronic inflammatory skin diseases, including contact dermatitis, atopic dermatitis and psoriasis. This review introduces some general aspects on the role of oxidative stress in cutaneous inflammation, with special emphasis on urticarias, summarizing recent novel findings derived from the study of physical urticarias and chronic idiopathic urticaria
Computational models for the simulation of the elastic and fracture properties of highly porous 3D-printed hydroxyapatite scaffolds
Bone scaffolding is a promising approach for the treatment of critical-size bone defects. Hydroxyapatite can be used to produce highly porous scaffolds as it mimics the mineralized part of bone tissue, but its intrinsic brittleness limits its usage. Among 3D printing techniques, vat photopolymerization allows for the best printing resolution for ceramic materials. In this study, we implemented a Computed micro-Tomography based Finite Element Model of a hydroxyapatite porous scaffold fabricated by vat photopolymerization. We used the model in order to predict the elastic and fracture properties of the scaffold. From the stress–strain diagram of a simulated compression test, we computed the stiffness and the strength of the scaffolds. We found that three morphometric features substantially affect the crack pattern. In particular, the crack propagation is not only dependent on the trabecular thickness but also depends on the slenderness and orientation of the trabeculae with respect to the load. The results found in this study can be used for the design of ceramic scaffolds with heterogeneous pore distribution in order to tailor and predict the compressive strength
The effect of boldness on decision-making in barnacle geese is group-size-dependent
In group-living species, decisions made by individuals may result in collective behaviours. A central question in understanding collective behaviours is how individual variation in phenotype affects collective behaviours. However, how the personality of individuals affects collective decisions in groups remains poorly understood. Here, we investigated the role of boldness on the decision-making process in different-sized groups of barnacle geese. Naive barnacle geese, differing in boldness score, were introduced in a labyrinth in groups with either one or three informed demonstrators. The demonstrators possessed information about the route through the labyrinth. In pairs, the probability of choosing a route prior to the informed demonstrator increased with increasing boldness score: bolder individuals decided more often for themselves where to go compared with shyer individuals, whereas shyer individuals waited more often for the demonstrators to decide and followed this information. In groups of four individuals, however, there was no effect of boldness on decision-making, suggesting that individual differences were less important with increasing group size. Our experimental results show that personality is important in collective decisions in pairs of barnacle geese, and suggest that bolder individuals have a greater influence over the outcome of decisions in groups
- …