Effect of different rhBMP-2 and TG-VEGF ratios on the formation of heterotopic bone and neovessels

Bioengineered bone substitutes might represent alternatives to autologous bone grafts in medically compromised patients due to reduced operation time and comorbidity. Due to the lack of an inherent vascular system their dimension is limited to the size of critical bone size defect. To overcome this shortcoming, the experiment tried to create heterotopic bone around vessels. In vivo, a two-component fibrin and thrombin gel containing recombinant bone morphogenic protein (rhBMP-2) and transglutamate vascular endothelial growth factor (TG-VEGF) in different ratios, respectively, was injected into a dimensionally stable membrane tube, wrapped around the femoral vessel bundle in twelve New Zealand white rabbits. Sacrifice occurred eight weeks postoperatively. Microcomputed tomography of the specimens showed significantly increased bone volume in the rhBMP-2 to TG-VEGF ratio of 10 to 1 group. Histology showed new bone formation in close proximity to the vessel bundle. Immunohistochemistry detected increased angiogenesis within the newly formed bone in the rhBMP-2 to TG-VEGF ratios of 3 to 1 and 5 to 1. Heterotopic bone was engineered in vivo around vessels using different rhBMP-2 and TG-VEGF ratios in a fibrin matrix injected into a dimensionally stable membrane tube which prevented direct contact with skeletal muscles.published_or_final_versio

Differential Effects of Temperature and Mosquito Genetics Determine Transmissibility of Arboviruses by <i>Aedes aegypti</i> in Argentina

Aedes aegypti (L.) (Diptera: Culicidae) have a global distribution and are the primary vector of a number of mosquito-borne viruses responsible for epidemics throughout the Americas. As in much of South America, the threat from pathogens including dengue virus (DENV; Flaviviridae, Flavivirus) and chikungunya virus (CHIKV; Togaviridae, Alphavirus) has increased in Argentina in recent years. The complexity of transmission cycles makes predicting the occurrence and intensity of arbovirus outbreaks difficult. To gain a better understanding of the risk of DENV and CHIKV in Argentina and the factors influencing this risk, we evaluated the role of population and temperature in the vector competence and vectorial capacity (VC) of Ae. aegypti from geographically and ecologically distinct locations. Our results demonstrate that intrinsic and extrinsic factors including mosquito population, viral species, and temperature significantly influence both vector competence and overall VC of Ae. aegypti in Argentina, yet also that the magnitude of these influences is highly variable. Specifically, results suggest that CHIKV competence is more dependent on mosquito genetics than is DENV competence, whereas temperature has a greater effect on DENV transmission. In addition, although there is an overall positive correlation between temperature and competence for both viruses, there are exceptions to this for individual virus?population combinations. Together, these data establish large variability in VC for these pathogens among distinct Ae. aegypti populations in Argentina and demonstrate that accurate assessment of arbovirus risk will require nuanced models that fully consider the complexity of interactions between virus, temperature, mosquito genetics, and hosts.Centro de Estudios Parasitológicos y de Vectore

Differential Effects of Temperature and Mosquito Genetics Determine Transmissibility of Arboviruses by <i>Aedes aegypti</i> in Argentina

Aedes aegypti (L.) (Diptera: Culicidae) have a global distribution and are the primary vector of a number of mosquito-borne viruses responsible for epidemics throughout the Americas. As in much of South America, the threat from pathogens including dengue virus (DENV; Flaviviridae, Flavivirus) and chikungunya virus (CHIKV; Togaviridae, Alphavirus) has increased in Argentina in recent years. The complexity of transmission cycles makes predicting the occurrence and intensity of arbovirus outbreaks difficult. To gain a better understanding of the risk of DENV and CHIKV in Argentina and the factors influencing this risk, we evaluated the role of population and temperature in the vector competence and vectorial capacity (VC) of Ae. aegypti from geographically and ecologically distinct locations. Our results demonstrate that intrinsic and extrinsic factors including mosquito population, viral species, and temperature significantly influence both vector competence and overall VC of Ae. aegypti in Argentina, yet also that the magnitude of these influences is highly variable. Specifically, results suggest that CHIKV competence is more dependent on mosquito genetics than is DENV competence, whereas temperature has a greater effect on DENV transmission. In addition, although there is an overall positive correlation between temperature and competence for both viruses, there are exceptions to this for individual virus?population combinations. Together, these data establish large variability in VC for these pathogens among distinct Ae. aegypti populations in Argentina and demonstrate that accurate assessment of arbovirus risk will require nuanced models that fully consider the complexity of interactions between virus, temperature, mosquito genetics, and hosts.Centro de Estudios Parasitológicos y de Vectore

Differential Effects of Temperature and Mosquito Genetics Determine Transmissibility of Arboviruses by <i>Aedes aegypti</i> in Argentina

Aedes aegypti (L.) (Diptera: Culicidae) have a global distribution and are the primary vector of a number of mosquito-borne viruses responsible for epidemics throughout the Americas. As in much of South America, the threat from pathogens including dengue virus (DENV; Flaviviridae, Flavivirus) and chikungunya virus (CHIKV; Togaviridae, Alphavirus) has increased in Argentina in recent years. The complexity of transmission cycles makes predicting the occurrence and intensity of arbovirus outbreaks difficult. To gain a better understanding of the risk of DENV and CHIKV in Argentina and the factors influencing this risk, we evaluated the role of population and temperature in the vector competence and vectorial capacity (VC) of Ae. aegypti from geographically and ecologically distinct locations. Our results demonstrate that intrinsic and extrinsic factors including mosquito population, viral species, and temperature significantly influence both vector competence and overall VC of Ae. aegypti in Argentina, yet also that the magnitude of these influences is highly variable. Specifically, results suggest that CHIKV competence is more dependent on mosquito genetics than is DENV competence, whereas temperature has a greater effect on DENV transmission. In addition, although there is an overall positive correlation between temperature and competence for both viruses, there are exceptions to this for individual virus?population combinations. Together, these data establish large variability in VC for these pathogens among distinct Ae. aegypti populations in Argentina and demonstrate that accurate assessment of arbovirus risk will require nuanced models that fully consider the complexity of interactions between virus, temperature, mosquito genetics, and hosts.Centro de Estudios Parasitológicos y de Vectore

Differential Effects of Temperature and Mosquito Genetics Determine Transmissibility of Arboviruses by Aedes aegypti in Argentina

Aedes aegypti (L.) (Diptera: Culicidae) have a global distribution and are the primary vector of a number of mosquito-borne viruses responsible for epidemics throughout the Americas. As in much of South America, the threat from pathogens including dengue virus (DENV; Flaviviridae, Flavivirus) and chikungunya virus (CHIKV; Togaviridae, Alphavirus) has increased in Argentina in recent years. The complexity of transmission cycles makes predicting the occurrence and intensity of arbovirus outbreaks difficult. To gain a better understanding of the risk of DENV and CHIKV in Argentina and the factors influencing this risk, we evaluated the role of population and temperature in the vector competence and vectorial capacity (VC) of Ae. aegypti from geographically and ecologically distinct locations. Our results demonstrate that intrinsic and extrinsic factors including mosquito population, viral species, and temperature significantly influence both vector competence and overall VC of Ae. aegypti in Argentina, yet also that the magnitude of these influences is highly variable. Specifically, results suggest that CHIKV competence is more dependent on mosquito genetics than is DENV competence, whereas temperature has a greater effect on DENV transmission. In addition, although there is an overall positive correlation between temperature and competence for both viruses, there are exceptions to this for individual virus?population combinations. Together, these data establish large variability in VC for these pathogens among distinct Ae. aegypti populations in Argentina and demonstrate that accurate assessment of arbovirus risk will require nuanced models that fully consider the complexity of interactions between virus, temperature, mosquito genetics, and hosts.Fil: Ciota, Alexander T.. Wadsworth Center. State of New York Department of Health; Estados UnidosFil: Chin, Pamela A.. Wadsworth Center. State of New York Department of Health; Estados UnidosFil: Ehrbar, Dylan J.. Wadsworth Center. State of New York Department of Health; Estados UnidosFil: Micieli, Maria Victoria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Estudios Parasitológicos y de Vectores. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Centro de Estudios Parasitológicos y de Vectores; ArgentinaFil: Fonseca, Dina M.. Center For Vector Biology, Rutgers University; Estados UnidosFil: Kramer, Laura D.. Wadsworth Center. State of New York Department of Health; Estados Unido

A red/far-red light-responsive bi-stable toggle switch to control gene expression in mammalian cells

Growth and differentiation of multicellular systems is orchestrated by spatially restricted gene expression programs in specialized subpopulations. The targeted manipulation of such processes by synthetic tools with high-spatiotemporal resolution could, therefore, enable a deepened understanding of developmental processes and open new opportunities in tissue engineering. Here, we describe the first red/far-red light-triggered gene switch for mammalian cells for achieving gene expression control in time and space. We show that the system can reversibly be toggled between stable on- and off-states using short light pulses at 660 or 740 nm. Red light-induced gene expression was shown to correlate with the applied photon number and was compatible with different mammalian cell lines, including human primary cells. The light-induced expression kinetics were quantitatively analyzed by a mathematical model. We apply the system for the spatially controlled engineering of angiogenesis in chicken embryos. The system's performance combined with cell- and tissue-compatible regulating red light will enable unprecedented spatiotemporally controlled molecular interventions in mammalian cells, tissues and organism

In vivo Sealing of Fetoscopy-Induced Fetal Membrane Defects by Mussel Glue

Introduction: The benefits of fetal surgery are impaired by the high incidence of iatrogenic preterm prelabor rupture of the fetal membranes (iPPROM), for which chorioamniotic separation has been suggested as a potential initiator. Despite the urgent need to prevent iPPROM by sealing the fetoscopic puncture site after intervention, no approach has been clinically translated. Methods: A mussel-inspired biomimetic glue was tested in an ovine fetal membrane (FM) defect model. The gelation time of mussel glue (MG) was first optimized to make it technically compatible with fetal surgery. Then, the biomaterial was loaded in polytetrafluoroethylene-coated nitinol umbrella-shaped receptors and applied on ovine FM defects (N = 10) created with a 10 French trocar. Its sealing performance and tissue response were analyzed 10 days after implantation by amniotic fluid (AF) leakage and histological methods. Results: All ewes and fetuses recovered well after the surgery, and 100% ewe survival and 91% fetal survival were observed at explantation. All implants were tight at explantation, and no AF leakage was observed in any of them. Histological analysis revealed a mild tissue response to the implanted glue. Conclusion: MG showed promising properties for the sealing of FM defects and thereby the prevention of preterm birth. Studies to analyze the long-term tissue response to the sealant should be performed

Tissue Glue-Based Sealing Patch for the in vivo Prevention of Iatrogenic Prelabor Preterm Rupture of Fetal Membranes

Introduction: One of the main concerns for all fetal surgeries is the risk of preterm delivery due to the preterm prelabor rupture of the fetal membranes (iPPROM). Clinical approaches to seal fetal membrane (FM) defects are missing due to the lack of appropriate strategies to apply sealing biomaterials at the defect site. Methods: Here, we test the performance of a previously developed strategy to seal FM defects with cyanoacrylate-based sealing patches in an ovine model up to 24 days after application. Results: Patches sealed tightly the fetoscopy-induced FM defects and remained firmly attached to the defect over 10 days. At 10 days after treatment, 100% (13/13) of the patches were attached to the FMs, and 24 days after treatment 25% (1/4) of the patches placed in CO$_2$ insufflation, and 33% (1/3) in NaCl infusion remained. However, all successfully applied patches (20/24) led to a watertight sealing at 10 or 24 days after treatment. Histological analysis indicated that cyanoacrylates induced a moderate immune response and disrupted the FM epithelium. Conclusion: Together, these data show the feasibility of minimally invasive sealing of FM defects by locally gathering tissue adhesive. Further development to combine this technology with refined tissue glues or healing-inducing materials holds great promise for future clinical translation

Identification and Functional Characterization of Gene Components of Type VI Secretion System in Bacterial Genomes

A new secretion system, called the Type VI Secretion system (T6SS), was recently reported in Vibrio cholerae, Pseudomonas aeruginosa and Burkholderia mallei. A total of 18 genes have been identified to be belonging to this secretion system in V. cholerae. Here we attempt to identify presence of T6SS in other bacterial genomes. This includes identification of orthologous sequences, conserved motifs, domains, families, 3D folds, genomic islands containing T6SS components, phylogenetic profiles and protein-protein association of these components. Our analysis indicates presence of T6SS in 42 bacteria and its absence in most of their non-pathogenic species, suggesting the role of T6SS in imparting pathogenicity to an organism. Analysis of genomic regions containing T6SS components, phylogenetic profiles and protein-protein association of T6SS components indicate few additional genes which could be involved in this secretion system. Based on our studies, functional annotations were assigned to most of the components. Except one of the genes, we could group all the other genes of T6SS into those belonging to the puncturing device, and those located in the outer membrane, transmembrane and inner membrane. Based on our analysis, we have proposed a model of T6SS and have compared the same with the other bacterial secretion systems