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1.
Reprod Biomed Online ; 49(4): 104120, 2024 May 18.
Artículo en Inglés | MEDLINE | ID: mdl-39084124

RESUMEN

RESEARCH QUESTION: To what extent does the type and concentration of protein and the type of culture medium affect the sensitivity of the mouse embryo assay (MEA) to detect Triton X-100 (TX-100) in culture media? DESIGN: The effect of the concentration of bovine serum albumin (BSA) and human serum albumin (HSA) was assessed by supplementing media with 0.5 or 5 mg/ml. Potassium-supplemented simplex optimized medium (KSOM) and human tubal fluid (HTF) were used as complex and simple formulation media, respectively. Variables were combined, forming study groups where embryos were cultured in test media spiked with a sublethal TX-100 concentration. The conditions of greatest sensitivity were determined by statistical comparison of blastocyst formation rates and total cell counts between groups. RESULTS: Although all of the study groups showed equal capacity for sustaining proper embryo development, the reported sensitivity of the MEA differed between groups when subjected to TX-100. HTF conferred significantly greater sensitivity than KSOM regardless of the type and concentration of protein used, and medium supplementation with 5 mg/ml BSA rather than 0.5 mg/ml BSA resulted in significantly higher sensitivity regardless of the type of medium used. This increase in concentration also resulted in higher sensitivity when supplementing HTF with HSA. The BSA groups provided more sensitivity than their HSA counterparts, except for the KSOM + 0.5 mg/ml BSA group. Cell count analysis did not provide further significant conclusions. CONCLUSIONS: For TX-100 detection within culture medium, the type and concentration of protein and the type of culture medium have a direct effect on MEA sensitivity. These results could help to standardize the MEA protocol, and increase its ability to detect sublethal concentrations of embryotoxic substances, especially TX-100, thus avoiding possible clinical harmful effects.

2.
Nucleic Acids Res ; 52(D1): D808-D816, 2024 Jan 05.
Artículo en Inglés | MEDLINE | ID: mdl-37953350

RESUMEN

The Eukaryotic Pathogen, Vector and Host Informatics Resource (VEuPathDB, https://veupathdb.org) is a Bioinformatics Resource Center funded by the National Institutes of Health with additional funding from the Wellcome Trust. VEuPathDB supports >600 organisms that comprise invertebrate vectors, eukaryotic pathogens (protists and fungi) and relevant free-living or non-pathogenic species or hosts. Since 2004, VEuPathDB has analyzed omics data from the public domain using contemporary bioinformatic workflows, including orthology predictions via OrthoMCL, and integrated the analysis results with analysis tools, visualizations, and advanced search capabilities. The unique data mining platform coupled with >3000 pre-analyzed data sets facilitates the exploration of pertinent omics data in support of hypothesis driven research. Comparisons are easily made across data sets, data types and organisms. A Galaxy workspace offers the opportunity for the analysis of private large-scale datasets and for porting to VEuPathDB for comparisons with integrated data. The MapVEu tool provides a platform for exploration of spatially resolved data such as vector surveillance and insecticide resistance monitoring. To address the growing body of omics data and advances in laboratory techniques, VEuPathDB has added several new data types, searches and features, improved the Galaxy workspace environment, redesigned the MapVEu interface and updated the infrastructure to accommodate these changes.


Asunto(s)
Biología Computacional , Eucariontes , Animales , Biología Computacional/métodos , Invertebrados , Bases de Datos Factuales
3.
Reprod Biomed Online ; 47(3): 103237, 2023 09.
Artículo en Inglés | MEDLINE | ID: mdl-37400320

RESUMEN

RESEARCH QUESTION: Can an automated sperm injection robot perform Automated Intracytoplasmic Sperm Injection (ICSIA) for use in human IVF? DESIGN: The ICSIA robot automated the sperm injection procedure, including injection pipette advancement, zona pellucida and oolemma penetration with piezo pulses, and pipette removal after sperm release. The robot was first tested in mouse, hamster and rabbit oocytes, and subsequently using discarded human oocytes injected with microbeads. A small clinical pilot trial was conducted with donor oocytes to study the feasibility of the robot in a clinical setting. The ICSIA robot was controlled by engineers with no micromanipulation experience. Results were compared with those obtained with manual ICSI conducted by experienced embryologists. RESULTS: The ICSIA robot demonstrated similar results to the manual procedure in the different animal models tested as well as in the pre-clinical validations conducted in discarded human oocytes. In the clinical validation, 13 out of 14 oocytes injected with ICSIA fertilized correctly versus 16 out of 18 in the manual control; eight developed into good-quality blastocysts versus 12 in the manual control; and four were diagnosed as chromosomally normal versus 10 euploid in the manual control. Three euploid blastocysts from the ICSIA robot group have been transferred into two recipients, which resulted in two singleton pregnancies and two babies born. CONCLUSIONS: The ICSIA robot showed high proficiency in injecting animal and human oocytes when operated by inexperienced personnel. The preliminary results obtained in this first clinical pilot trial are within key performance indicators.


Asunto(s)
Fertilización In Vitro , Inyecciones de Esperma Intracitoplasmáticas , Femenino , Humanos , Masculino , Embarazo , Fertilización , Fertilización In Vitro/métodos , Oocitos , Semen , Inyecciones de Esperma Intracitoplasmáticas/métodos , Espermatozoides
4.
PLoS Negl Trop Dis ; 17(4): e0010862, 2023 04.
Artículo en Inglés | MEDLINE | ID: mdl-37043542

RESUMEN

Phlebotomine sand flies are of global significance as important vectors of human disease, transmitting bacterial, viral, and protozoan pathogens, including the kinetoplastid parasites of the genus Leishmania, the causative agents of devastating diseases collectively termed leishmaniasis. More than 40 pathogenic Leishmania species are transmitted to humans by approximately 35 sand fly species in 98 countries with hundreds of millions of people at risk around the world. No approved efficacious vaccine exists for leishmaniasis and available therapeutic drugs are either toxic and/or expensive, or the parasites are becoming resistant to the more recently developed drugs. Therefore, sand fly and/or reservoir control are currently the most effective strategies to break transmission. To better understand the biology of sand flies, including the mechanisms involved in their vectorial capacity, insecticide resistance, and population structures we sequenced the genomes of two geographically widespread and important sand fly vector species: Phlebotomus papatasi, a vector of Leishmania parasites that cause cutaneous leishmaniasis, (distributed in Europe, the Middle East and North Africa) and Lutzomyia longipalpis, a vector of Leishmania parasites that cause visceral leishmaniasis (distributed across Central and South America). We categorized and curated genes involved in processes important to their roles as disease vectors, including chemosensation, blood feeding, circadian rhythm, immunity, and detoxification, as well as mobile genetic elements. We also defined gene orthology and observed micro-synteny among the genomes. Finally, we present the genetic diversity and population structure of these species in their respective geographical areas. These genomes will be a foundation on which to base future efforts to prevent vector-borne transmission of Leishmania parasites.


Asunto(s)
Leishmania , Leishmaniasis Cutánea , Phlebotomus , Psychodidae , Animales , Humanos , Phlebotomus/parasitología , Psychodidae/parasitología , Leishmania/genética , Genómica
5.
Fertil Steril ; 119(6): 964-973, 2023 06.
Artículo en Inglés | MEDLINE | ID: mdl-36787873

RESUMEN

OBJECTIVES: To gain insights into the technical feasibility of maternal spindle transfer (MST) applied in the context of repeated in vitro fertilization (IVF) failures for the treatment of idiopathic infertility. DESIGN: A prospective pilot study. SETTING: IVF center. PATIENT(S): Twenty-five infertile couples with multiple previous unsuccessful IVF cycles (range, 3-11), no previous pregnancy, and no history of mitochondrial DNA (mtDNA) disease participated. The study focused on women <40 years, with previous IVF attempts characterized by a pattern of low fertilization rates and/or impaired embryo development. Couples with severe male-factor infertility were not eligible. Oocyte donors with previous successful IVF outcomes were matched with patients according to standard practice. INTERVENTION(S): We performed MST by transferring metaphase II spindles from the patients' oocytes into the previously enucleated donor oocytes, followed by intracytoplasmic sperm injection, in vitro embryo culture, blastocyst biopsy, and vitrification. Only euploid blastocysts were considered for embryo transfer. MAIN OUTCOME MEASURE(S): Outcome measures included oocyte fertilization, blastocyst development, clinical pregnancy and live birth, incidence of mitochondrial carryover and potential mtDNA reversal, as well as general health of the children born. RESULT(S): Twenty-eight MST cycles produced 6 children (19 embryo transfers, 7 clinical pregnancies). Pediatric follow-up of the children, performed at intervals from birth to 12-24 months of age, revealed their development to be unremarkable. DNA fingerprinting confirmed that the nuclear DNA of MST children was inherited from both parents, without any contribution from the oocyte donor. For 5 of the children, mtDNA was derived almost exclusively (>99%) from the donor. However, 1 child, who had similarly low mtDNA carryover (0.8%) at the blastocyst stage, showed an increase in the maternal mtDNA haplotype, accounting for 30% to 60% of the total at birth. CONCLUSION(S): This pilot study provides the first insights into the feasibility of applying MST for patients with idiopathic infertility and repeated IVF failures. Reconstructed oocytes produced embryos capable of implanting, developing to term and producing apparently healthy newborns/children. However, claims concerning the efficacy of MST with respect to infertility treatment would be premature considering the limitations of this study. Importantly, mtDNA reversal was detected in one child born after MST, a finding with possible implications for mitochondrial replacement therapies. CLINICAL TRIAL REGISTRATION NUMBER: Pilot trial registry number, ISRCTN11455145. The date of registration: 20/02/2018. The date of enrolment of the first patients: 18/03/2018.


Asunto(s)
Infertilidad Masculina , Semen , Embarazo , Humanos , Masculino , Femenino , Proyectos Piloto , Estudios Prospectivos , Fertilización In Vitro , ADN Mitocondrial/genética , Índice de Embarazo , Estudios Retrospectivos
6.
Curr Opin Insect Sci ; 50: 100860, 2022 04.
Artículo en Inglés | MEDLINE | ID: mdl-34864248

RESUMEN

VectorBase (VectorBase.org) is part of the VEuPathDB Bioinformatics Resource Center, providing free online access to multi-omics and population biology data, focusing on arthropod vectors and invertebrates of importance to human health. VectorBase includes genomics and functional genomics data from bed bugs, biting midges, body lice, kissing bugs, mites, mosquitoes, sand flies, ticks, tsetse flies, stable flies, house flies, fruit flies, and a snail intermediate host. Tools include the Search Strategy system and MapVEu, enabling users to interrogate and visualize diverse 'omics and population-level data using a graphical interface (no programming experience required). Users can also analyze their own private data, such as transcriptomic sequences, exploring their results in the context of other publicly-available information in the database. Help Desk: help@vectorbase.org.


Asunto(s)
Biología Computacional , Culicidae , Animales , Genómica , Humanos , Invertebrados/genética , Mosquitos Vectores
7.
Nucleic Acids Res ; 50(D1): D898-D911, 2022 01 07.
Artículo en Inglés | MEDLINE | ID: mdl-34718728

RESUMEN

The Eukaryotic Pathogen, Vector and Host Informatics Resource (VEuPathDB, https://veupathdb.org) represents the 2019 merger of VectorBase with the EuPathDB projects. As a Bioinformatics Resource Center funded by the National Institutes of Health, with additional support from the Welllcome Trust, VEuPathDB supports >500 organisms comprising invertebrate vectors, eukaryotic pathogens (protists and fungi) and relevant free-living or non-pathogenic species or hosts. Designed to empower researchers with access to Omics data and bioinformatic analyses, VEuPathDB projects integrate >1700 pre-analysed datasets (and associated metadata) with advanced search capabilities, visualizations, and analysis tools in a graphic interface. Diverse data types are analysed with standardized workflows including an in-house OrthoMCL algorithm for predicting orthology. Comparisons are easily made across datasets, data types and organisms in this unique data mining platform. A new site-wide search facilitates access for both experienced and novice users. Upgraded infrastructure and workflows support numerous updates to the web interface, tools, searches and strategies, and Galaxy workspace where users can privately analyse their own data. Forthcoming upgrades include cloud-ready application architecture, expanded support for the Galaxy workspace, tools for interrogating host-pathogen interactions, and improved interactions with affiliated databases (ClinEpiDB, MicrobiomeDB) and other scientific resources, and increased interoperability with the Bacterial & Viral BRC.


Asunto(s)
Bases de Datos Factuales , Vectores de Enfermedades/clasificación , Interacciones Huésped-Patógeno/genética , Fenotipo , Interfaz Usuario-Computador , Animales , Apicomplexa/clasificación , Apicomplexa/genética , Apicomplexa/patogenicidad , Bacterias/clasificación , Bacterias/genética , Bacterias/patogenicidad , Enfermedades Transmisibles/microbiología , Enfermedades Transmisibles/parasitología , Enfermedades Transmisibles/patología , Enfermedades Transmisibles/transmisión , Biología Computacional/métodos , Minería de Datos/métodos , Diplomonadida/clasificación , Diplomonadida/genética , Diplomonadida/patogenicidad , Hongos/clasificación , Hongos/genética , Hongos/patogenicidad , Humanos , Insectos/clasificación , Insectos/genética , Insectos/patogenicidad , Internet , Nematodos/clasificación , Nematodos/genética , Nematodos/patogenicidad , Filogenia , Virulencia , Flujo de Trabajo
8.
Clin Trials ; 18(5): 615-621, 2021 10.
Artículo en Inglés | MEDLINE | ID: mdl-34154428

RESUMEN

The COVID-19 pandemic has resulted in unprecedented challenges for healthcare systems worldwide. It has also stimulated research in a wide range of areas including rapid diagnostics, novel therapeutics, use of technology to track patients and vaccine development. Here, we describe our experience of rapidly setting up and delivering a novel COVID-19 vaccine trial, using clinical and research staff and facilities in three National Health Service Trusts in Cambridgeshire, United Kingdom. We encountered and overcame a number of challenges including differences in organisational structures, research facilities available, staff experience and skills, information technology and communications infrastructure, and research training and assessment procedures. We overcame these by setting up a project team that included key members from all three organisations that met at least daily by teleconference. This group together worked to identify the best practices and procedures and to harmonise and cascade these to the wider trial team. This enabled us to set up the trial within 25 days and to recruit and vaccinate the participants within a further 23 days. The lessons learned from our experiences could be used to inform the conduct of clinical trials during a future infectious disease pandemic or public health emergency.


Asunto(s)
Vacunas contra la COVID-19/uso terapéutico , COVID-19 , Ensayos Clínicos como Asunto/normas , Pandemias , COVID-19/prevención & control , Ensayos Clínicos como Asunto/organización & administración , Humanos , Pandemias/prevención & control , Medicina Estatal , Reino Unido/epidemiología
9.
F S Sci ; 2(1): 43-49, 2021 02.
Artículo en Inglés | MEDLINE | ID: mdl-35559763

RESUMEN

OBJECTIVE: To study the effect of zona opening (ZO) and 2 zona thinning (ZT) techniques on the hatching process of mouse embryos using a last-generation laser system and time-lapse microscopy (TLM). DESIGN: Prospective randomized study. SETTING: Private research center. ANIMALS: A total of 267 F1 hybrid (B6/CBA) mice embryos were included. INTERVENTION(S): Morulae were randomly selected and the zona pellucida (ZP) manipulated using a laser system according to 4 experimental groups: control (ZP intact, n = 59), ZO (25 µm hole, n = 70), ZT25 (25% perimeter thinned, n = 71), and ZT35 (35% perimeter thinned, n = 67). Embryo development was monitored by TLM until day 6. MAIN OUTCOME MEASURE(S): Time to first breach the ZP, hatching time, time to complete hatching, multiple breaching, multiple hatching, loss of cells, hole size, and embryo quality were analyzed. RESULT(S): No significant differences in the proportion of completely hatched embryos were found among groups. However, the time (average hours ± SD) to complete hatching was significantly delayed in the control group compared with all laser-treated groups: 118.3 ± 9.5 hours in the ZT25 group, 116.6 ± 8.7 hours in the ZT35 group, and 120.4 ± 9.9 hours in the ZO group. The applied laser techniques did not interfere with the quality of the blastocysts at day 5/6 of culture. CONCLUSION(S): ZO, ZT25, and ZT35 embryos hatched significantly earlier than the zona intact group without increasing the multiple hatching rates, suggesting an improvement of the hatching process. This study found that the pattern of the hatching process after ZT and ZO differs.


Asunto(s)
Blastocisto , Microscopía , Animales , Rayos Láser , Ratones , Ratones Endogámicos CBA , Estudios Prospectivos , Imagen de Lapso de Tiempo
10.
Int J Mol Sci ; 21(18)2020 Sep 09.
Artículo en Inglés | MEDLINE | ID: mdl-32916828

RESUMEN

Aedes aegypti is the primary mosquito vector of several human arboviruses, including the dengue virus (DENV). Vector control is the principal intervention to decrease the transmission of these viruses. The characterization of molecules involved in the mosquito physiological responses to blood-feeding may help identify novel targets useful in designing effective control strategies. In this study, we evaluated the in vivo effect of feeding adult female mosquitoes with human red blood cells reconstituted with either heat-inactivated (IB) or normal plasma (NB). The RNA-seq based transcript expression of IB and NB mosquitoes was compared against sugar-fed (SF) mosquitoes. In in vitro experiments, we treated Aag2 cells with a recombinant version of complement proteins (hC3 or hC5a) and compared transcript expression to untreated control cells after 24 h. The transcript expression analysis revealed that human complement proteins modulate approximately 2300 transcripts involved in multiple biological functions, including immunity. We also found 161 upregulated and 168 downregulated transcripts differentially expressed when human complement protein C3 (hC3) and human complement protein C5a (hC5a) treated cells were compared to the control untreated cells. We conclude that active human complement induces significant changes to the transcriptome of Ae. aegypti mosquitoes, which may influence the physiology of these arthropods.


Asunto(s)
Aedes/metabolismo , Mosquitos Vectores/metabolismo , Transcriptoma , Aedes/inmunología , Animales , Complemento C3 , Complemento C5a , Femenino , Humanos , Mosquitos Vectores/inmunología
11.
Elife ; 92020 04 29.
Artículo en Inglés | MEDLINE | ID: mdl-32347793

RESUMEN

The developmental potential of early embryos is mainly dictated by the quality of the oocyte. Here, we explore the utility of the maternal spindle transfer (MST) technique as a reproductive approach to enhance oocyte developmental competence. Our proof-of-concept experiments show that replacement of the entire cytoplasm of oocytes from a sensitive mouse strain overcomes massive embryo developmental arrest characteristic of non-manipulated oocytes. Genetic analysis confirmed minimal carryover of mtDNA following MST. Resulting mice showed low heteroplasmy levels in multiple organs at adult age, normal histology and fertility. Mice were followed for five generations (F5), revealing that heteroplasmy was reduced in F2 mice and was undetectable in the subsequent generations. This pre-clinical model demonstrates the high efficiency and potential of the MST technique, not only to prevent the transmission of mtDNA mutations, but also as a new potential treatment for patients with certain forms of infertility refractory to current clinical strategies.


Infertility is a growing problem that affects millions of people worldwide. Medical procedures known as in vitro fertilization (IVF) help many individuals experiencing infertility to have children. Typically in IVF, a woman's egg cells are collected, fertilized with sperm from a chosen male and grown for a few days in a laboratory, before returning them to the woman's body to continue to develop. However, there are some women whose egg cells cannot develop into a healthy baby after they have been fertilized. Many of these patients use egg cells from donors, instead. This greatly improves the chances of the IVF treatment being successful, but the resultant children are not genetically related to the intended mothers. Previous studies suggested that a cell compartment known as the cytoplasm plays a crucial role in allowing fertilized egg cells to develop normally. A new technique known as maternal spindle transfer, often shortened to MST, makes it possible to replace the entire cytoplasm of a compromised egg cell. This is achieved by transplanting the genetic material of the compromised egg cell into a donor egg cell with healthier cytoplasm that has previously had its own genetic material removed. Using this technique, it is possible to generate human egg cells for IVF that have the genetic material from the intended mother without the defects in the cytoplasm that may be responsible for infertility. However, it is not clear whether this approach would be a safe and effective way to treat infertility in humans. Costa-Borges et al. applied MST to infertile female mice and found that the technique could permanently correct deficiencies in the cytoplasms of poor quality egg cells, allowing the mice to give birth to healthy offspring. Further experiments studied the offspring and their descendants over several generations and found that they also had higher quality egg cells and normal levels of fertility. These findings open up the possibility of developing new treatments for infertility caused by problems with egg cells, so experiments involving human egg cells are now being performed to evaluate the safety and effectiveness of the technique.


Asunto(s)
Desarrollo Embrionario/fisiología , Terapia de Reemplazo Mitocondrial/métodos , Animales , ADN Mitocondrial/genética , Femenino , Ratones , Mutación , Oocitos/fisiología , Embarazo
12.
Reprod Biomed Online ; 39(4): 547-555, 2019 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-31327727

RESUMEN

RESEARCH QUESTION: Can culture conditions influence the sensitivity of a Mouse Embryo Assay and its potential to detect peroxide-related toxicity in mineral oil samples? DESIGN: Protein type and concentration, embryo density and culture dish design were selected as the variables in the culture system with the potential to influence the assay's sensitivity. Fresh 1-cell mouse embryos were cultured under mineral oil samples with known peroxide concentrations. Protein type (human serum albumin [HSA] + α/ß-Globulins versus HSA versus bovine serum albumin [BSA]), concentration (5 mg/ml versus 0.5 mg/ml), embryo density (25 versus 3 µl/embryo) and culture dish (Petri versus micro-well dish) were adjusted to define the culture conditions with the highest sensitivity. RESULTS: High concentrations of peroxides can be easily detected by current quality control standards. However, for oil samples with a lower concentration of peroxides, supplementing the culture medium with 5 mg/ml of HSA + alpha/beta-globulins or with HSA resulted in an increased detection of embryo toxicity compared with when BSA was used as the protein supplement. The sensitivity of the assay was greatly reduced when embryos were cultured in groups and when certain micro-well dishes were used. CONCLUSIONS: Current quality control protocols may not be sensitive enough to identify low concentrations of peroxides, which, if undetected, can increase over time and become potentially harmful during gamete and embryo culture. The different parameters established in this study allow the sensitivity of the Mouse Embryo Assays to be optimized to specifically detect peroxides in mineral oil samples prior to their release into the market and their broad use in human IVF.


Asunto(s)
Bioensayo , Técnicas de Cultivo de Embriones/métodos , Embrión de Mamíferos/citología , Ratones/embriología , Aceite Mineral/química , Peróxidos/aislamiento & purificación , Animales , Bioensayo/métodos , Bioensayo/normas , Células Cultivadas , Medios de Cultivo/química , Medios de Cultivo/farmacología , Contaminación de Medicamentos , Técnicas de Cultivo de Embriones/normas , Desarrollo Embrionario/efectos de los fármacos , Femenino , Fertilización In Vitro/métodos , Fertilización In Vitro/normas , Masculino , Ratones Endogámicos C57BL , Ratones Endogámicos CBA , Aceite Mineral/farmacología , Peróxidos/toxicidad , Proteínas/fisiología , Control de Calidad , Pruebas de Toxicidad/métodos , Pruebas de Toxicidad/normas
13.
Sci Data ; 6(1): 40, 2019 04 25.
Artículo en Inglés | MEDLINE | ID: mdl-31024009

RESUMEN

Arthropods play a dominant role in natural and human-modified terrestrial ecosystem dynamics. Spatially-explicit arthropod population time-series data are crucial for statistical or mathematical models of these dynamics and assessment of their veterinary, medical, agricultural, and ecological impacts. Such data have been collected world-wide for over a century, but remain scattered and largely inaccessible. In particular, with the ever-present and growing threat of arthropod pests and vectors of infectious diseases, there are numerous historical and ongoing surveillance efforts, but the data are not reported in consistent formats and typically lack sufficient metadata to make reuse and re-analysis possible. Here, we present the first-ever minimum information standard for arthropod abundance, Minimum Information for Reusable Arthropod Abundance Data (MIReAD). Developed with broad stakeholder collaboration, it balances sufficiency for reuse with the practicality of preparing the data for submission. It is designed to optimize data (re)usability from the "FAIR," (Findable, Accessible, Interoperable, and Reusable) principles of public data archiving (PDA). This standard will facilitate data unification across research initiatives and communities dedicated to surveillance for detection and control of vector-borne diseases and pests.


Asunto(s)
Artrópodos , Almacenamiento y Recuperación de la Información/normas , Animales , Artrópodos/fisiología , Biodiversidad , Ecosistema , Difusión de la Información , Dinámica Poblacional
14.
Agora USB ; 18(1): 236-244, ene.-jun. 2018.
Artículo en Español | LILACS | ID: biblio-949814

RESUMEN

Resumen La implementación de rutas de formación para los docentes orientados a la cualificación, diseño y aplicación de recursos educativos digitales son necesarios y prioritarios para que las instituciones avancen hacia la transformación cultural requerida en los procesos de enseñanza-aprendizaje con soporte en las TIC. Esto implica una revisión de la construcción de los conceptos de comunidades de aprendizaje, práctica, práctica virtual, zona de desarrollo próximo en la práctica pedagógica, las relaciones en los ambientes virtuales de aprendizaje y las competencias docentes en el uso de las TIC.


Abstract The implementation of teacher training pathways aiming at the qualifica tion, design, and application of digital educational resources are necessary and priority so that institutions move towards the required cultural transformation in the teaching and learning processes with ICT support. This involves a review of the construction of the concept of communities of learning, communities of practice, virtual practice, zone of proximal development in pedagogical practice, relationships in virtual learning environments, and educational expertise in the use of ICT.

15.
Cryobiology ; 81: 107-116, 2018 04.
Artículo en Inglés | MEDLINE | ID: mdl-29475071

RESUMEN

Vitrification is currently a well-established technique for the cryopreservation of oocytes and embryos. It can be achieved either by direct (open systems) or indirect (closed systems) contact with liquid nitrogen. While there is not a direct evidence of disease transmission by transferred cryopreserved embryos, it was experimentally demonstrated that cross-contamination between liquid nitrogen and embryos may occur, and thus, the use of closed devices has been recommended to avoid the risk of contamination. Unfortunately, closed systems may result in lower cooling rates compared to open systems, due to the thermal insulation of the samples, which may cause ice crystal formation resulting in impaired results. In our study, we aimed to validate a newly developed vitrification device (Cryotop SC) that has been specifically designed for being used as a closed system. The cooling and warming rates calculated for the closed system were 5.254 °C/min and 43.522 °C/min, respectively. Results obtained with the closed system were equivalent to those with the classic Cryotop (open system), with survival rates in oocytes close to 100%. Similarly, the potential of the survived oocytes to develop up to good quality blastocysts after parthenogenetic activation between both groups was statistically equivalent. Assessment of the meiotic spindle and chromosome distribution by fluorescence microscopy in vitrified oocytes showed alike morphologies between the open and closed system. No differences were found either between the both systems in terms of survival rates of one-cell stage embryos or blastocysts, as well as, in the potential of the vitrified/warmed blastocysts to develop to full-term after transferred to surrogate females.


Asunto(s)
Criopreservación/instrumentación , Oocitos , Vitrificación , Animales , Blastocisto/fisiología , Criopreservación/métodos , Femenino , Ratones
17.
Nat Commun ; 8: 15451, 2017 05 16.
Artículo en Inglés | MEDLINE | ID: mdl-28508897

RESUMEN

Biomphalaria snails are instrumental in transmission of the human blood fluke Schistosoma mansoni. With the World Health Organization's goal to eliminate schistosomiasis as a global health problem by 2025, there is now renewed emphasis on snail control. Here, we characterize the genome of Biomphalaria glabrata, a lophotrochozoan protostome, and provide timely and important information on snail biology. We describe aspects of phero-perception, stress responses, immune function and regulation of gene expression that support the persistence of B. glabrata in the field and may define this species as a suitable snail host for S. mansoni. We identify several potential targets for developing novel control measures aimed at reducing snail-mediated transmission of schistosomiasis.


Asunto(s)
Biomphalaria/genética , Biomphalaria/parasitología , Genoma , Esquistosomiasis mansoni/transmisión , Comunicación Animal , Animales , Biomphalaria/inmunología , Elementos Transponibles de ADN , Evolución Molecular , Agua Dulce , Regulación de la Expresión Génica , Interacciones Huésped-Parásitos , Feromonas , Proteoma , Schistosoma mansoni , Análisis de Secuencia de ADN , Estrés Fisiológico
18.
BMC Evol Biol ; 17(1): 84, 2017 03 21.
Artículo en Inglés | MEDLINE | ID: mdl-28320313

RESUMEN

BACKGROUND: Opsins are light sensitive receptors associated with visual processes. Insects typically possess opsins that are stimulated by ultraviolet, short and long wavelength (LW) radiation. Six putative LW-sensitive opsins predicted in the yellow fever mosquito, Aedes aegypti and malaria mosquito, Anopheles gambiae, and eight in the southern house mosquito, Culex quinquefasciatus, suggest gene expansion in the Family Culicidae (mosquitoes) relative to other insects. Here we report the first detailed molecular and evolutionary analyses of LW opsins in three mosquito vectors, with a goal to understanding the molecular basis of opsin-mediated visual processes that could be exploited for mosquito control. RESULTS: Time of divergence estimates suggest that the mosquito LW opsins originated from 18 or 19 duplication events between 166.9/197.5 to 1.07/0.94 million years ago (MY) and that these likely occurred following the predicted divergence of the lineages Anophelinae and Culicinae 145-226 MY. Fitmodel analyses identified nine amino acid residues in the LW opsins that may be under positive selection. Of these, eight amino acids occur in the N and C termini and are shared among all three species, and one residue in TMIII was unique to culicine species. Alignment of 5' non-coding regions revealed potential Conserved Non-coding Sequences (CNS) and transcription factor binding sites (TFBS) in seven pairs of LW opsin paralogs. CONCLUSIONS: Our analyses suggest opsin gene duplication and residues possibly associated with spectral tuning of LW-sensitive photoreceptors. We explore two mechanisms - positive selection and differential expression mediated by regulatory units in CNS - that may have contributed to the retention of LW opsin genes in Culicinae and Anophelinae. We discuss the evolution of mosquito LW opsins in the context of major Earth events and possible adaptation of mosquitoes to LW-dominated photo environments, and implications for mosquito control strategies based on disrupting vision-mediated behaviors.


Asunto(s)
Culicidae/genética , Proteínas de Insectos/genética , Opsinas de Bastones/genética , Secuencia de Aminoácidos , Animales , Secuencia Conservada , Culicidae/clasificación , Evolución Molecular , Duplicación de Gen , Proteínas de Insectos/química , Filogenia , Opsinas de Bastones/química , Alineación de Secuencia
19.
Immunity ; 46(1): 133-147, 2017 01 17.
Artículo en Inglés | MEDLINE | ID: mdl-28087239

RESUMEN

Immuno-surveillance networks operating at barrier sites are tuned by local tissue cues to ensure effective immunity. Site-specific commensal bacteria provide key signals ensuring host defense in the skin and gut. However, how the oral microbiome and tissue-specific signals balance immunity and regulation at the gingiva, a key oral barrier, remains minimally explored. In contrast to the skin and gut, we demonstrate that gingiva-resident T helper 17 (Th17) cells developed via a commensal colonization-independent mechanism. Accumulation of Th17 cells at the gingiva was driven in response to the physiological barrier damage that occurs during mastication. Physiological mechanical damage, via induction of interleukin 6 (IL-6) from epithelial cells, tailored effector T cell function, promoting increases in gingival Th17 cell numbers. These data highlight that diverse tissue-specific mechanisms govern education of Th17 cell responses and demonstrate that mechanical damage helps define the immune tone of this important oral barrier.


Asunto(s)
Encía/inmunología , Inmunidad Mucosa/inmunología , Vigilancia Inmunológica/inmunología , Mucosa Bucal/inmunología , Células Th17/inmunología , Animales , Citometría de Flujo , Encía/microbiología , Humanos , Masticación , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Microbiota , Mucosa Bucal/microbiología , Reacción en Cadena en Tiempo Real de la Polimerasa
20.
Nat Commun ; 7: 10507, 2016 Feb 09.
Artículo en Inglés | MEDLINE | ID: mdl-26856261

RESUMEN

Ticks transmit more pathogens to humans and animals than any other arthropod. We describe the 2.1 Gbp nuclear genome of the tick, Ixodes scapularis (Say), which vectors pathogens that cause Lyme disease, human granulocytic anaplasmosis, babesiosis and other diseases. The large genome reflects accumulation of repetitive DNA, new lineages of retro-transposons, and gene architecture patterns resembling ancient metazoans rather than pancrustaceans. Annotation of scaffolds representing ∼57% of the genome, reveals 20,486 protein-coding genes and expansions of gene families associated with tick-host interactions. We report insights from genome analyses into parasitic processes unique to ticks, including host 'questing', prolonged feeding, cuticle synthesis, blood meal concentration, novel methods of haemoglobin digestion, haem detoxification, vitellogenesis and prolonged off-host survival. We identify proteins associated with the agent of human granulocytic anaplasmosis, an emerging disease, and the encephalitis-causing Langat virus, and a population structure correlated to life-history traits and transmission of the Lyme disease agent.


Asunto(s)
Anaplasma phagocytophilum , Vectores Arácnidos/genética , Genoma/genética , Ixodes/genética , Canales Iónicos Activados por Ligandos/genética , Animales , Perfilación de la Expresión Génica , Genómica , Enfermedad de Lyme/transmisión , Oocitos , Xenopus laevis
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