Current Status in Peripheral Nerve Xenotransplantation

Nerve grafts are used to repair segmental defects in peripheral nerves. However, autografts and even allografts are limited for clinical use. Xenotransplantation offers a potentially unlimited source for tissue transplantation. We have conducted a systematic review of the literature, aiming to clarify the latest and more appealing proposals and discoveries in nerve xenotransplantation. A total of 22 articles were retrieved, all of them experimentally controlled studies in animals. There are no current studies in humans. Fresh xenografts provoke an immune response that leads to graft rejection. Immunosuppressive drugs or pretreatment of the grafts are the preferred methods against immune rejection. Recently, investigative groups have proposed the use of acellular nerve xenografts, which do not elicit immune rejection while they do allow and promote axonal regeneration. The addition of human stem cells increases nerve growth. Limits to the analyzed studies are the absence of trials in humans and the short length of the nerve defects that have been successfully repaired. Further investigations and clinical trials are needed before nerve xenografting is accepted as a valid method of nerve repair

Automated Jerboa Startling Device

ME450 Capstone Design and Manufacturing Experience: Winter 2021A hallway module that startles a jerboa with an air puff as well as a noise tone. It will then record the jerboa throughout the length of the hallway as well as take data from a force platform on the Jerboa.Talia Moore: Moore Biomechanicshttp://deepblue.lib.umich.edu/bitstream/2027.42/167640/1/Team_23-Automated_Jerboa_Startling_Device.pd

¿La pandemia del Covid-19 aceleró la automatización en países en desarrollo? Evidencia para Colombia

Este documento evalúa si la pandemia del Covid-19 aceleró el proceso de automatización en países en desarrollo. El estudio se enfoca en Colombia, un país con baja inversión en Investigación y Desarrollo (I&D), baja productividad, además de una alta informalidad laboral y desempleo. Se estima un modelo de estudio de eventos para evaluar si durante la pandemia se presentó un efecto diferencial en la demanda laboral de acuerdo al grado potencial de automatización de las ocupaciones. Nuestros resultados sugieren que, durante la pandemia, tanto las vacantes como el nivel de empleo asalariado cayeron más en ocupaciones con alto potencial de automatización y, desde entonces, han presentado una recuperación mucho más lenta. Este efecto se ha observado principalmente en los sectores que se vieron afectados por las restricciones de movilidad. Igualmente encontramos efectos heterogéneos por edad y género, donde el mercado laboral de las mujeres y los individuos mayores de 40 años han sido los más afectados. Finalmente, exploramos el efecto diferencial en las ocupaciones con salarios alrededor del salario mínimo; los resultados indican que las ocupaciones con salarios más cerca al salario mínimo son las más afectadas, especialmente al inicio de la pandemia.This paper assesses whether the Covid-19 pandemic accelerated automation in developing countries. We studied the case of Colombia, a country with low R&D and productivity and with high labor informality and unemployment. We estimated event-study models to assess the differential effect of the pandemic on job openings and salaried employment by the potential degree of automation of each occupation. Our results suggest that both vacancies and salaried employment fell more in highly automatable occupations during the pandemic and have since experienced a slower recovery. The effect of the pandemic on automation is mostly driven by sectors that were affected by mobility restrictions. We also found heterogeneous effects by age and gender. The acceleration of automation is mainly affecting the labor market for females and individuals over the age of 40. Finally, we explored the differential effect on occupations with wages around the minimum wage. We found that occupations with wages close to the minimum wage exhibit the highest effect, especially at the onset of the pandemic.Enfoque Evidencias recientes sugieren que la pandemia, y en particular la crisis de Covid-19, tendieron a acelerar el proceso de automatización en economías desarrolladas como es el caso de Estados Unidos y Reino Unido. Sin embargo, pocos estudios se han enfocado en las economías en desarrollo. En este documento se evalúa si la pandemia aceleró el proceso de automatización en Colombia, un país en desarrollo, caracterizado por la combinación de baja inversión en investigación & desarrollo (I&D), y productividad, además de altos niveles de informalidad y desempleo. Contribución Este documento contribuye a la literatura sobre el impacto que pudo tener la pandemia sobre la demanda laboral en oficios con alto potencial de automatización, ofreciendo evidencia de un país de ingreso medio como Colombia con altos niveles de informalidad y desempleo. La demanda por nuevos puestos trabajos durante la pandemia se mide usando las vacantes por ocupaciones obtenidas a través del Servicio Público de Empleo (SPE) de Colombia. Adicionalmente se utiliza el nivel de empleo asalariado, basado en la Gran Encuesta Integrado de Hogares (GEIH). La probabilidad de automatización por ocupaciones se mide utilizando la metodología de Frey y Osborne (2017) y Nedelkoska y Quintini (2018) adaptada al caso colombiano. Finalmente se usa un enfoque de estudio de eventos para evaluar el efecto diferencial de la pandemia en las vacantes del SPE y el empleo asalariado, dependiendo de su potencial de automatización. Resultados Los resultados indican que durante la pandemia del Covid-19 las vacantes cayeron más significativamente en ocupaciones con alto potencial de automatización. Estos efectos son persistentes, con coeficientes significativos hasta el último periodo analizado (agosto del 2021). Igualmente, estos efectos negativos y significativos se encuentran en el nivel de empleo, particularmente en el empleo asalariado. Además, se explora en qué medida el impacto en las ocupaciones automatizables fue mayor en sectores que fueron más afectados por las restricciones de movilidad durante la pandemia del Covid-19. Los resultados indican que la mayor parte de estos efectos se presentaron en los sectores más afectados. Por lo tanto, esto sugiere que las restricciones de movilidad incrementaron el costo del trabajo relativo al capital, incentivando la automatización durante la pandemia. Estos resultados son robustos incluso cuando se controla por tendencias sectoriales o cuando se usan medidas alternativas del potencial de automatización (Chernoff and Warman, 2020). Adicionalmente, se encuentra un efecto diferencial en el empleo, de acuerdo con ciertas características demográficas como la edad, el género y la productividad de los trabajadores (en el último caso, utilizando como proxy el salario mínimo)

Baseline and time-updated factors in preclinical development of anionic dendrimers as successful anti-HIV-1 vaginal microbicides

Although a wide variety of topical microbicides provide promising in vitro and in vivo efficacy, most of them failed to prevent sexual transmission of human immunodeficiency virus type 1 (HIV-1) in human clinical trials. In vitro, ex vivo, and in vivo models must be optimized, considering the knowledge acquired from unsuccessful and successful clinical trials to improve the current gaps and the preclinical development protocols. To date, dendrimers are the only nanotool that has advanced to human clinical trials as topical microbicides to prevent HIV-1 transmission. This fact demonstrates the importance and the potential of these molecules as microbicides. Polyanionic dendrimers are highly branched nanocompounds with potent activity against HIV-1 that disturb HIV-1 entry. Herein, the most significant advancements in topical microbicide development, trying to mimic the real-life conditions as closely as possible, are discussed. This review also provides the preclinical assays that anionic dendrimers have passed as microbicides because they can improve current antiviral treatments' efficacy.This work has been (partially) funded by the RD16/0025/0019 projects as part of Acción Estratégica en Salud, Plan Nacional de Investigación Científica, Desarrollo e Innovación Tecnológica (2013–2016) and cofinanced by Instituto de Salud Carlos III (ISCIII) and Fondo Europeo de Desarrollo Regional (FEDER), RETIC PT17/0015/0042, Fondo de Investigacion Sanitaria (FIS) (grant no. PI16/01863) and EPIICAL project. COST CA17140 Cancer Nanomedicine-“From the Bench to Bedside.” This work has also been supported by the Ministry of Economy and Competitiveness #CGL2013-40564-R and Gordon and Betty Moore Foundation grant no. 5334. This work was also funded by research grants from ISCIII (grant numbers PI20CIII/00004, and RD16CIII/0002/0002) to Salvador Resino. The study was also funded by the Centro de Investigación Biomédica en Red en Enfermedades Infecciosas (CB21/13/00044). DS-C is a “Sara Borrell” researcher from ISCIII (grant no. CD20CIII/00001).S

Diseño de un panel multicolor para evaluar moléculas intracelulares y de superficie mediante citometría de flujo

Introduction: Flow cytometry allows simultaneous detection of surface and intracellular molecules on each cell.Objective: To describe a method for building up a harmonic multicolor panel with 11 flow cytometry parameters for phenotypic and functional analysis on CD8+ T lymphocytes.Materials and methods: For the multicolor panel construction, we selected the molecules and titred conjugated antibodies with fluorochromes for CD3, CD8, CCR7, CD28, CD27, CD45RA, CD95 and CD127 determination in peripheral blood mononuclear cells (PBMC). To evaluate the panel, theconjugated antibodies were gradually added one by one and fluorescence minus one (FMO) test was performed. This method was applied to assess ex vivo subpopulations of T cells and the production of intracellular IFNγ, IL-2 and TNFα using polyclonal stimulation with enterotoxin B from Staphylococcus aureus (SEB) and antigen-specific cells with crude Trypanosoma cruzi antigen. Finally, the ex vivo CD8+ T lymphocyte subpopulations frequencies were analyzed in healthy individuals.Results: The evaluation of the selected molecules and conjugates did not show interference in the fluorescence signals and detection. The frequencies of CD8+ T cells evaluated were similar to the values reported in other studies. Additionally, we observed that the frequency of CD8+ T lymphocytes producing IFNγ, IL-2 and TNFα was higher 6 hours after culture with SEB and crude T. cruzi lysate.Conclusions: The method used for the construction of a multicolor panel allows obtaining frequencies of CD8+ T lymphocyte subpopulations corresponding to those reported in the literature.doi: http://dx.doi.org/10.7705/biomedica.v33i4.1709Introducción. La citometría de flujo permite detectar la presencia de moléculas intracelulares y de superficie, de forma simultánea sobre cada célula.Objetivo. Describir un método para la construcción armónica de un panel multicolor con 11 parámetros para el análisis fenotípico y funcional de linfocitos T (LT) CD8+ por citometría de flujo.Materiales y métodos. Para la construcción del panel multicolor, se seleccionaron las moléculas y se titularon los conjugados con fluorocromos para la determinación de CD3, CD8, CCR7, CD28, CD27,CD45RA, CD95 y CD127, en células mononucleares de sangre periférica. Para la evaluación del panel, se hizo la construcción progresiva adicionando uno a uno los conjugados y la fluorescencia menos uno (FMO). Este método fue aplicado para células ex vivo y para evaluar la producción de IFNγ, IL-2 y TNFα frente al estímulo con la enterotoxina B de Staphylococcus aureus (SEB) y al antígeno crudo de Trypanosoma cruzi. Finalmente, se procedió al análisis de las subpoblaciones de LT CD8+ exvivo en individuos sanos.Resultados. La evaluación de las moléculas con los conjugados no mostró interferencia en las señales de fluorescencia. Las frecuencias de las subpoblaciones de LT CD8+ evaluadas fueron cercanas a los valores reportados en otros estudios. Además, se observó que la frecuencia de LT CD8+ productores de IFNγ, IL-2 y TNFα fue mayor a las seis horas de cultivo con SEB y con el antígeno crudo de T. cruzi.Conclusiones. El método aplicado para la construcción del panel multicolor permite obtener frecuencias de las subpoblaciones de LT CD8+ que corresponden a lo reportado en la literatura científica. doi: http://dx.doi.org/10.7705/biomedica.v33i4.1709

Population genomics of Plasmodium vivax in Panama to assess the risk of case importation on malaria elimination

Malaria incidence in Panama has plateaued in recent years in spite of elimination efforts, with almost all cases caused by Plasmodium vivax. Notwithstanding, overall malaria prevalence remains low (fewer than 1 case per 1000 persons). We used selective whole genome amplification to sequence 59 P. vivax samples from Panama. The P. vivax samples were collected from two periods (2007–2009 and 2017–2019) to study the population structure and transmission dynamics of the parasite. Imported cases resulting from increased levels of human migration could threaten malaria elimination prospects, and four of the samples evaluated came from individuals with travel history. We explored patterns of recent common ancestry among the samples and observed that a highly genetically related lineage (termed CL1) was dominant among the samples (47 out of 59 samples with good sequencing coverage), spanning the entire period of the collection (2007–2019) and all regions of the country. We also found a second, smaller clonal lineage (termed CL2) of four parasites collected between 2017 and 2019. To explore the regional context of Panamanian P. vivax we conducted principal components analysis and constructed a neighbor-joining tree using these samples and samples collected worldwide from a previous study. Three of the four samples with travel history clustered with samples collected from their suspected country of origin (consistent with importation), while one appears to have been a result of local transmission. The small number of Panamanian P. vivax samples not belonging to either CL1 or CL2 clustered with samples collected from Colombia, suggesting they represent the genetically similar ancestral P. vivax population in Panama or were recently imported from Colombia. The low diversity we observe in Panama indicates that this parasite population has been previously subject to a severe bottleneck and may be eligible for elimination. Additionally, while we confirmed that P. vivax is imported to Panama from diverse geographic locations, the lack of impact from imported cases on the overall parasite population genomic profile suggests that onward transmission from such cases is limited and that imported cases may not presently pose a major barrier to elimination

Criterios biológicos y ecológicos: aportes para la identificación, caracterización y delimitación de los humedales interiores de Colombia.

Este producto es elaborado por el Programa Biología de la Conservación y Uso de la Biodiversidad en el marco del convenio 005 (13-014) entre el Instituto Humboldt y el Fondo Adaptación, en este documento se asume los principios generales de los ecosistemas, en los que se caracterizan como sistemas complejos, abiertos, dinámicos e integrados en donde los patrones ecológicas y la diversidad biológica son el resultado de un proceso biogeográfico que a su vez es afectado por procesos antrópicos. Es por ello que los ecosistemas de humedales de interior son considerados unidades funcionales en los que son necesarias las conexiones de la transición de hábitats en función de la pendiente natural (cuenca aguas arriba y abajo), hacia los ecosistemas adyacentes terrestres y dentro del cuerpo de agua (entre las zonas someras y profundas).Bogotá, ColombiaPrograma Biología de la Conservación y Uso de la Biodiversida

Lympho-SPECT/CT as a tool to evaluate postoperative outcomes after LVA for lymphedema repair

Aim: To describe findings when comparing lympho-SPECT-CT images before and after lymphovenous anastomosis (LVA) surgeries and to correlate these results with pre- and post-operative volume changes in the limbs of patients.Methods: An observational, prospective, longitudinal study was designed. 20 consecutive patients were treated for lymphedema by means of LVA between 2015 and 2018. All were affected by secondary lymphedema (ISG II-III) following lymphadenectomy, radiation or both. All patients received preoperative rehabilitation as well as radiotherapy after oncological surgery. Limb volume was measured before surgery and at one year later. LVA was performed under general anesthesia with ICG guidance. ICG was also used to evaluate postoperative outcomes. Lympho-SPECT-CT was performed in all subjects at their first consultation and at one year after every surgical intervention. Description of findings included an absence of lymph nodes, new lymph node activity in anatomical areas and new lymphatic activity in extra-anatomical areas.Results: Limb volume decreased in 19 patients after LVA. Six patients showed preoperative linear ICG patterns, combined with areas presenting with another type of pattern. After LVA, the linear pattern was observed in 11 patients. SPECT-CT/lymphoscintigraphy before surgery showed a total absence of lymph nodes, except in two cases, in whom small nodes in anatomical locations were described. After LVA, we observed new landmarks in 16 patients corresponding to lymphatic circulation that was not present in preoperative studies. In six cases, new lymphatic activity compatible with lymph nodes was detectable after LVA. The Spearman correlation coefficient was negative when circumferences and lympho-SPECT-CT were tested (P = 0.02).Conclusion: Results showed a postoperative decrease in volume that correlated inversely with lympho-SPECT/CT findings. Lympho-SPECT/CT provided additional information related to accurate identification and the anatomical location of lymphatic structures that were not observed before reconstructive surgery. It can be a complementary test to conventional lymphoscintigraphy

Do all Cu nanoparticles have similar applications in nano-enabled agriculture?

abstract: Copper-based chemicals have been widely used in agriculture as fertilizers and pesticides. Although these products have been essential to ensure food security, their continuous use has resulted in environmental pollution with detrimental effects for certain living organisms. Efforts have been put in place to reduce pollution derived from Cu application in agriculture. However, there is still a long way to go to reduce agrochemical applications without affecting food security. Copper-based nanomaterials including metallic copper (Cu NPs, nCu) copper oxide (CuO NPs, nCuO) and copper hydroxide [Cu(OH)2 nanowires, nCu(OH)2, Cu(OH)2 NPs] appear as the alternative to replace traditional copper-based agrochemicals. The available literature shows that the three nanomaterials have exhibited capabilities as nanofertilizers or nanopesticides. However, the data is very scattered and, in some cases, inconsistent. This minireview shows the most recent results from investigations about the effects of the three Cu-based nanomaterials in agricultural production. Advantages and disadvantages are discussed and research questions to guide future investigations are stated