17 research outputs found
Carboxyl-modified single-wall carbon nanotubes improve bone tissue formation in vitro and repair in an in vivo rat model.
The clinical management of bone defects caused by trauma or nonunion fractures remains a challenge in orthopedic practice due to the poor integration and biocompatibility properties of the scaffold or implant material. In the current work, the osteogenic properties of carboxyl-modified single-walled carbon nanotubes (COOH-SWCNTs) were investigated in vivo and in vitro. When human preosteoblasts and murine embryonic stem cells were cultured on coverslips sprayed with COOH-SWCNTs, accelerated osteogenic differentiation was manifested by increased expression of classical bone marker genes and an increase in the secretion of osteocalcin, in addition to prior mineralization of the extracellular matrix. These results predicated COOH-SWCNTs' use to further promote osteogenic differentiation in vivo. In contrast, both cell lines had difficulties adhering to multi-walled carbon nanotube-based scaffolds, as shown by scanning electron microscopy. While a suspension of SWCNTs caused cytotoxicity in both cell lines at levels >20 μg/mL, these levels were never achieved by release from sprayed SWCNTs, warranting the approach taken. In vivo, human allografts formed by the combination of demineralized bone matrix or cartilage particles with SWCNTs were implanted into nude rats, and ectopic bone formation was analyzed. Histological analysis of both types of implants showed high permeability and pore connectivity of the carbon nanotube-soaked implants. Numerous vascularization channels appeared in the formed tissue, additional progenitor cells were recruited, and areas of de novo ossification were found 4 weeks post-implantation. Induction of the expression of bone-related genes and the presence of secreted osteopontin protein were also confirmed by quantitative polymerase chain reaction analysis and immunofluorescence, respectively. In summary, these results are in line with prior contributions that highlight the suitability of SWCNTs as scaffolds with high bone-inducing capabilities both in vitro and in vivo, confirming them as alternatives to current bone-repair therapies
Incentivar el uso de bolsas biodegradables a la comunidad de la Institución Educativa Enrique Vélez Escobar en el municipio de Itagüí mediante la Educación Ambiental como instrumento de protección de los recursos naturales.
Este proyecto de grado se realiza en la Institución Educativa Enrique Vélez Escobar en el municipio de Itagüí Antioquia, con el fin de incentivar y sensibilizar a los estudiantes a utilizar bolsas biodegradables implementando una Educación Ambiental para protección del entorno, mejorando el paisaje y realizando una gestión ambiental que permanezca en el tiempo para su consolidación. Lo anterior se basó en análisis cualitativos, cuantitativos y costumbres cotidianas de los alumnos en el uso de bolsas plásticas, con el fin de realizar la implantación del uso de bolsas biodegradables mediante estrategias de educación ambiental como conferencias, videos y aplicación de encuestas realizadas entre el 20 de febrero y el 26 de abril de 2018. La metodología utilizada fue realizada o de la sensibilización en salones de clase con charlas, realización de carteleras, recolección grupal de residuos sólidos, siembra de jardín, entre otras actividades, para conocer sus percepciones acerca de las consecuencias de la utilización de plásticos y los beneficios de reemplazarlos por bolsas biodegradables.
El trabajo arrojó como resultado que de acuerdo con el diagnóstico realizado el 10% de la población no utiliza las bolsas biodegradables y/o reutilizables. Luego después de la implantación de las estrategias de educación ambiental, se obtuvo que el 3 a 4% de la población entre los 13 y 14 años mejoraron los hábitos de reciclaje y de utilización de las bolsas.This degree project is carried out at the Enrique Vélez Escobar Educational Institution in the municipality of Itagüí Antioquia, in order to encourage and sensitize students to use biodegradable bags, implementing an Environmental Education to protect the environment, improving the landscape and carrying out a management environmental that remains in time for consolidation. This was based on qualitative, quantitative and daily habits of students in the use of plastic bags, in order to implement the use of biodegradable bags through environmental education strategies such as lectures, videos and surveys conducted between the February 20 and April 26, 2018. The methodology used was made or sensitization in classrooms with lectures, billboards, group collection of solid waste, garden planting, among other activities, all of that to know their perceptions about the consequences of using plastics and the benefits of replacing them with biodegradable bags.
The work showed that according to the diagnosis made, 10% of the population does not use biodegradable and / or reusable bags. After the implementation of environmental education strategies, it was obtained that 3 to 4% of the population between 13 and 14 years improved the habits of recycling and use of the bags
Reviewing the Composition of Vaginal Microbiota: Inclusion of Nutrition and Probiotic Factors in the Maintenance of Eubiosis
The vaginal microbiota has importance in preserving vaginal health and defending
the host against disease. The advent of new molecular techniques and computer science has
allowed researchers to discover microbial composition in depth and associate the structure of
vaginal microbial communities. There is a consensus that vaginal flora is grouped into a restricted
number of communities, although the structure of the community is constantly changing. Certain
Community-State Types (CSTs) are more associated with poor reproductive outcomes and sexually
transmitted diseases (STDs) meanwhile, CSTs dominated by Lactobacillus species—particularly
Lactobacillus crispatus—are more related to vaginal health. In this work, we have reviewed how
modifiable and non-modifiable factors may affect normal vaginal microbiota homeostasis—including
sexual behavior, race or ethnicity, and hygiene. Special interest has been given to how the use of
probiotics, diet intake, and use of hormone replacement therapies (HRTs) can potentially impact
vaginal microbiota composition
Extracellular Protease ADAMTS1 Is Required at Early Stages of Human Uveal Melanoma Development by Inducing Stemness and Endothelial-Like Features on Tumor Cells
We would like to thank members of JCRM’s laboratory and GENYO’s support units for
helping with animal handling, technical assistance, and further discussion. The results published here are in part
based upon data generated by the TCGA Research Network (www.cancer.gov/tcga). This manuscript will be part
of CPT PhD Thesis belonging to the Doctorate Program on Biomedicine, UGR, Spain.Extracellular matrix remodeling within the tumor microenvironment has been recognized
as a relevant dynamic framework during tumor growth. However, research on proteases that trigger
this remodeling keeps revealing a wide range of actions including both pro- and anti-tumorigenic.
The extracellular protease ADAMTS1 exemplifies this dual role. In this work, we first confirmed
a positive correlation of ADAMTS1 with endothelial-like phenotype of human melanoma cells
together with the finding of associated signatures, including key genes such as endothelial CDH5.
Using a CRISPR-Cas9 approach, we observed that the inhibition of ADAMTS1 in an aggressive
uveal melanoma model compromised its endothelial-like properties, and more importantly, caused a
robust blockade on the progression of tumor xenografts. Although vasculature emerged affected
in ADAMTS1-deficient tumors, the most relevant action implied the downregulation of endothelial
CDH5 in tumor cells, in association with stemness markers. Indeed, melanoma sphere assays also
revealed a deficient commitment to form spheres in the absence of ADAMTS1, directly correlating
with stemness markers and, remarkably, also with CDH5. Finally, taking advantage of advanced
bioinformatics tools and available public data of uveal melanomas, we disclosed new prognosis
factors, including endothelial elements and ADAMTS proteases. Our findings support the key role of
ADAMTS proteases for uveal melanoma development since earlier stages, modulating the complex
crosstalk between extracellular matrix and the induction of stemness and endothelial-like features.
To our knowledge, this is the first report that supports the development of therapeutic targets on the
extracellular matrix to overcome uveal melanoma.This research was supported by Ministerio de Economía y Competitividad and Instituto de Salud
Carlos III from Spain, co-financed by FEDER (PI16/00345 to JCRM) and from Consejería de Salud de la Junta de
Andalucía (OH-0028-2018, PE-0225-2018)
Exon sequence requirements for excision in vivo of the bacterial group II intron RmInt1
<p>Abstract</p> <p>Background</p> <p>Group II intron splicing proceeds through two sequential transesterification reactions in which the 5' and 3'-exons are joined together and the lariat intron is released. The intron-encoded protein (IEP) assists the splicing of the intron <it>in vivo </it>and remains bound to the excised intron lariat RNA in a ribonucleoprotein particle (RNP) that promotes intron mobility. Exon recognition occurs through base-pairing interactions between two guide sequences on the ribozyme domain dI known as EBS1 and EBS2 and two stretches of sequence known as IBS1 and IBS2 on the 5' exon, whereas the 3' exon is recognized through interaction with the sequence immediately upstream from EBS1 [(δ-δ' interaction (subgroup IIA)] or with a nucleotide [(EBS3-IBS3 interaction (subgroup IIB and IIC))] located in the coordination-loop of dI. The δ nucleotide is involved in base pairing with another intron residue (δ') in subgroup IIB introns and this interaction facilitates base pairing between the 5' exon and the intron.</p> <p>Results</p> <p>In this study, we investigated nucleotide requirements in the distal 5'- and 3' exon regions, EBS-IBS interactions and δ-δ' pairing for excision of the group IIB intron RmInt1 <it>in vivo</it>. We found that the EBS1-IBS1 interaction was required and sufficient for RmInt1 excision. In addition, we provide evidence for the occurrence of canonical δ-δ' pairing and its importance for the intron excision <it>in vivo.</it></p> <p>Conclusions</p> <p>The excision <it>in vivo </it>of the RmInt1 intron is a favored process, with very few constraints for sequence recognition in both the 5' and 3'-exons. Our results contribute to understand how group II introns spread in nature, and might facilitate the use of RmInt1 in gene targeting.</p
Carboxyl-modified single-wall carbon nanotubes improve bone tissue formation in vitro and repair in an in vivo rat model.
Use of RmInt1, a Group IIB Intron Lacking the Intron-Encoded Protein Endonuclease Domain, in Gene Targeting ▿
The group IIA intron Ll.LtrB from Lactococcus lactis and the group IIB intron EcI5 from Escherichia coli have intron-encoded proteins (IEP) with a DNA-binding domain (D) and an endonuclease domain (En). Both have been successfully retargeted to invade target DNAs other than their wild-type target sites. RmInt1, a subclass IIB3/D intron with an IEP lacking D and En domains, is highly active in retrohoming in its host, Sinorhizobium meliloti. We found that RmInt1 was also mobile in E. coli and that retrohoming in this heterologous host depended on temperature, being more efficient at 28°C than at 37°C. Furthermore, we programmed RmInt1 to recognize target sites other than its wild-type site. These retargeted introns efficiently and specifically retrohome into a recipient plasmid target site or a target site present as a single copy in the chromosome, generating a mutation in the targeted gene. Our results extend the range of group II introns available for gene targeting