Purification of rabies virus glycoprotein produced in Drosophila melanogaster S2 cells: An efficient immunoaffinity method

Most rabies vaccines are based on inactivated virus, which production process demands a high level of biosafety structures. In the past decades, recombinant rabies virus glycoprotein (RVGP) produced in several expression systems has been extensively studied to be used as an alternative vaccine. The immunogenic characteristics of this protein depend on its correct conformation, which is present only after the correct post-translational modifications, typically performed by animal cells. The main challenge of using this protein as a vaccine candidate is to keep its trimeric conformation after the purification process. We describe here a new immunoaffinity chromatography method using a monoclonal antibody for RVGP Site II for purification of recombinant rabies virus glycoprotein expressed on the membrane of Drosophila melanogaster S2 cells. RVGP recovery achieved at least 93%, and characterization analysis showed that the main antigenic proprieties were preserved after purification.     

Using life cycle assessment to achieve a circular economy

The International Journal of Life Cycle Assessment - The current global interest in circular economy (CE) opens an opportunity to make society’s consumption and production patterns more...     

Felling the giants: integral projection models indicate adult management to control an exotic invasive palm

Plant Ecology - Population models are helpful for understanding demographic trends in invasive plants and crucial in defining effective management actions. Here, we assessed the dynamics of three...     

The relative importance of spatial and environmental processes in the assembly of larval Chironomidae (Insecta,Diptera) communities along a transition landscape in southern Brazilian streams

Limnology - Metacommunity structure of stream invertebrates is contingent on complex interplays between species dispersal ability, spatial extent and watershed environmental specificities. Previous...     

An analytical model for the ergometer rowing: inverse multibody dynamics analysis

A model for the ergometer rowing exercise is presented in this paper. From the quantitative observations of a particular trajectory (motion), the model is used to determine the moment of the forces produced by the muscles about each joint. These forces are evaluated according to the continuous system of equations of motion. An inverse dynamics analysis is performed in order to predict the joint torques developed by the muscles during the execution of the task. An elementary multibody mechanical system is used as an example to discuss the assumptions and procedures adopted.     

Bone remodelling analysis of a bovine femur for a veterinary implant design

The response of bovine bone to the presence of an implant is analysed with the aim of simulating bone remodelling in a developing model of a polymeric intramedullary interlocking nail for veterinary use. A 3-D finite element model of the femur diaphysis is built based on computed tomography images and using a CAD-based modelling pipeline. The bone remodelling process after the surgery is analysed and compared with the healthy bone. The remodelling law assumes that bone adapts to the mechanical environment. For the analyses a consistent set of loads is determined for the bovine walk cycle. The remodelling results reproduce the morphologic features of bone and provide evidence of the difference on the bone behaviour when comparing metallic and polymeric nails. Our findings indicate that an intramedullary polymeric nail has the advantage over the metallic one of improving long-term bone healing and possibly avoiding the need of the implant removal.     

Calcitriol downregulates TNF-α and IL-6 expression in cultured placental cells from preeclamptic women

Placenta is an important source and target of hormones that contribute to immunological tolerance and maintenance of pregnancy. In preeclampsia (PE), placental calcitriol synthesis is low; whereas pro-inflammatory cytokines levels are increased, threatening pregnancy outcome. Previously, we showed that calcitriol inhibits Th-1 cytokines under experimental inflammatory conditions in normal trophoblasts. However, a study of the regulation of inflammatory cytokines by calcitriol in trophoblasts from a natural inflammatory condition, such as PE, is still lacking. Therefore, the aim of the present study was to investigate calcitriol effects upon TNF-α, IFN-γ, IL-6 and IL-1β in cultured placental cells from preeclamptic women by using qPCR and ELISA. Placentas were collected after cesarean section from preeclamptic women and enriched trophoblastic preparations were cultured in the absence or presence of different calcitriol concentrations during 24 h. In these cell cultures, pro-inflammatory cytokines TNF-α and IL-6 secretion and mRNA expression were downregulated by calcitriol (P < 0.05). No significant effects of calcitriol upon IFN-γ and IL-1β were observed. In addition, basal expression of TNF-α, IL-6 and IL-1β decreased as the cells formed syncytia. Our study supports an important autocrine/paracrine role of placental calcitriol in controlling adverse immunological responses at the feto–maternal interface, particularly in gestational pathologies associated with exacerbated inflammatory responses such as preeclampsia.     

Mantel test in population genetics

The comparison of genetic divergence or genetic distances, estimated by pairwise F_ST and related statistics, with geographical distances by Mantel test is one of the most popular approaches to evaluate spatial processes driving population structure. There have been, however, recent criticisms and discussions on the statistical performance of the Mantel test. Simultaneously, alternative frameworks for data analyses are being proposed. Here, we review the Mantel test and its variations, including Mantel correlograms and partial correlations and regressions. For illustrative purposes, we studied spatial genetic divergence among 25 populations of Dipteryx alata (“Baru”), a tree species endemic to the Cerrado, the Brazilian savannas, based on 8 microsatellite loci. We also applied alternative methods to analyze spatial patterns in this dataset, especially a multivariate generalization of Spatial Eigenfunction Analysis based on redundancy analysis. The different approaches resulted in similar estimates of the magnitude of spatial structure in the genetic data. Furthermore, the results were expected based on previous knowledge of the ecological and evolutionary processes underlying genetic variation in this species. Our review shows that a careful application and interpretation of Mantel tests, especially Mantel correlograms, can overcome some potential statistical problems and provide a simple and useful tool for multivariate analysis of spatial patterns of genetic divergence.     

Phylogenetic Analysis Reveals a High Prevalence of Sporothrix brasiliensis in Feline Sporotrichosis Outbreaks

Sporothrix schenckii, previously assumed to be the sole agent of human and animal sporotrichosis, is in fact a species complex. Recently recognized taxa include S. brasiliensis, S. globosa, S. mexicana, and S. luriei, in addition to S. schenckii sensu stricto. Over the last decades, large epidemics of sporotrichosis occurred in Brazil due to zoonotic transmission, and cats were pointed out as key susceptible hosts. In order to understand the eco-epidemiology of feline sporotrichosis and its role in human sporotrichosis a survey was conducted among symptomatic cats. Prevalence and phylogenetic relationships among feline Sporothrix species were investigated by reconstructing their phylogenetic origin using the calmodulin (CAL) and the translation elongation factor-1 alpha (EF1α) loci in strains originated from Rio de Janeiro (RJ, n = 15), Rio Grande do Sul (RS, n = 10), Paraná (PR, n = 4), São Paulo (SP, n = 3) and Minas Gerais (MG, n = 1). Our results showed that S. brasiliensis is highly prevalent among cats (96.9%) with sporotrichosis, while S. schenckii was identified only once. The genotype of Sporothrix from cats was found identical to S. brasiliensis from human sources confirming that the disease is transmitted by cats. Sporothrix brasiliensis presented low genetic diversity compared to its sister taxon S. schenckii. No evidence of recombination in S. brasiliensis was found by split decomposition or PHI-test analysis, suggesting that S. brasiliensis is a clonal species. Strains recovered in states SP, MG and PR share the genotype of the RJ outbreak, different from the RS clone. The occurrence of separate genotypes among strains indicated that the Brazilian S. brasiliensis epidemic has at least two distinct sources. We suggest that cats represent a major host and the main source of cat and human S. brasiliensis infections in Brazil.