4,036 research outputs found

    The Emergent Power of Human Cellular vs Mouse Models in Translational Hair Research

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    Different animal models have been used for hair research and regeneration studies based on the similarities between animal and human skins. Primary knowledge on hair follicle (HF) biology has arisen from research using mouse models baring spontaneous or genetically engineered mutations. These studies have been crucial for the discovery of genes underlying human hair cycle control and hair loss disorders. Yet, researchers have become increasingly aware that there are distinct architectural and cellular features between the mouse and human HFs, which might limit the translation of findings in the mouse models. Thus, it is enticing to reason that the spotlight on mouse models and the unwillingness to adapt to the human archetype have been hampering the emergence of the long-awaited human hair loss cure. Here, we provide an overview of the major limitations of the mainstream mouse models for human hair loss research, and we underpin a future course of action using human cell bioengineered models and the emergent artificial intelligence.This work was supported by FEDER (Fundo Europeu de Desenvolvimento Regional) funds through COMPETE 2020 (POCI, Programa Operacional Competividade e Internacionalização) and Portugal 2020 in the framework of the project 70201-SI I&DT EMPRESAS EM COPROMOÇÃO. E.L. was supported by CEECIND/00654/2020 grant from FCT—Fundação para a Ciência e a Tecnologia, I.P

    Chiral Analysis of Pesticides and Drugs of Environmental Concern: Biodegradation and Enantiomeric Fraction

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    The importance of stereochemistry for medicinal chemistry and pharmacology is well recognized and the dissimilar behavior of enantiomers is fully documented. Regarding the environment, the significance is equivalent since enantiomers of chiral organic pollutants can also differ in biodegradation processes and fate, as well as in ecotoxicity. This review comprises designed biodegradation studies of several chiral drugs and pesticides followed by enantioselective analytical methodologies to accurately measure the enantiomeric fraction (EF). The enantioselective monitoring of microcosms and laboratory-scale experiments with different environmental matrices is herein reported. Thus, this review focuses on the importance of evaluating the EF variation during biodegradation studies of chiral pharmaceuticals, drugs of abuse, and agrochemicals and has implications for the understanding of the environmental fate of chiral pollutants.The authors wish to thank Fundação para a Ciência e Tecnologia—FCT for financial support under the project Fluoropharma PTDC/EBB-EBI/111699/2009, the PhD grant attributed to Alexandra S. Maia SFRH/BD/86939/2012, QREN-POPH, European Social Fund, MCTES, PEst FCOMP-01-0124-FEDER-022718; PEst-OE/EQB/LA0016/2011, PEst-OE/SAU/UI4040/2014. This research was partially supported by the Strategic Funding UID/Multi/04423/2013 through national funds provided by FCT—Fundação para a Ciência e Tecnologia and European Regional Development Fund (ERDF), in the framework of the program PT2020 and by CESPU (ChiralDrugs_CESPU_2017

    High yield and high quality DNA from vegetative and sexual tissues of Mexican white pine (Pinus ayacahuite)

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    Pines are considered to be difficult for DNA extraction. However, from one species to the other there is variation in phenolic profiles and seed size that might affect final DNA yields and quality. Two DNA extraction protocols (CTAB and SDS based) were compared for their ability to produce DNA on leaves, gametophyte and embryo from Pinus ayacahuite, a pine species with a large seed (8 - 18 mm). The DNA obtained from both procedures was quantified and tested by PCR. The CTAB protocol provided higher DNA yields from vegetative tissue and embryo than the SDS method. Embryos (2n) and gametophytes (n) proved to be very good sources of DNA and the DNA isolated was suitable for PCR-RAPD and SSRmarkers. This paper reports the results and describes the modified CTAB protocol

    Roles of the hox proteins in cancer invasion and metastasis

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    Invasion and metastasis correspond to the foremost cause of cancer-related death, and the molecular networks behind these two processes are extremely complex and dependent on the intra-and extracellular conditions along with the prime of the premetastatic niche. Currently, several studies suggest an association between the levels of HOX genes expression and cancer cell invasion and metastasis, which favour the formation of novel tumour masses. The deregulation of HOX genes by HMGA2/TET1 signalling and the regulatory effect of noncoding RNAs generated by the HOX loci can also promote invasion and metastasis, interfering with the expression of HOX genes or other genes relevant to these processes. In this review, we present five molecular mechanisms of HOX deregulation by which the HOX clusters products may affect invasion and metastatic processes in solid tumours.The work was financed by FEDER (Fundo Europeu de Desenvolvimento Regional) funds through the COMPETE 2020 Operational Programme for Competitiveness and Internationalisa-tion (POCI), Portugal 2020, and by Portuguese funds through FCT (Fundação para a Ciência e a Tecnologia/Ministério da Ciência, Tecnologia e Ensino Superior) in the framework of the project POCI-01-0145-FEDER-030562 (PTDC/BTM-TEC/30562/2017). The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed

    An Unexpected Association in a Patient with Heart Failure Presenting a Surgical Challenge

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    Bicuspid aortic valve (BAV) is the most common form of congenital heart disease and frequently leads to premature valvular dysfunction. BAV is associated with aortic wall abnormalities and a high prevalence of ascending aorta dilatation and coarctation of the aorta (CoA). Consequently, in patients with BAV a careful assessment of the valve, and also of the aortic root and the ascending aorta, should be performed. The most feared complication is aortic dissection, however, the actual incidence of this complication is low. We report the case of a 58-year-old man who presented with New York Heart Association class III heart failure. The work-up revealed BAV with severe stenosis and severe compromise of left ventricle systolic function. In addition, CoA in the isthmus region, and type B dissection of the aorta were diagnosed.info:eu-repo/semantics/publishedVersio

    Aerobic biological treatment of wastewaters containing dichloromethane

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    BACKGROUND: Volatilization has been advanced as one of the predominant phenomena contributing to volatile organic carbon emissions from wastewater treatment plants (WWTPs). In this study, strategies for minimizing such air stripping losses when treating a liquid stream containing dichloromethane (DCM), aiming at decreasing the overall emission inventory from WWTPs, were investigated. RESULTS: System R1, consisting of a continuous flow stirred tank reactor (CSTR) treating a liquid stream containing DCM at a concentration of 12 mmol dm−3 presented a biodegradation efficiency (BE) of 68%, based upon chloride release, with 10% of measurable losses, mainly due to volatilization, and 22% of unmeasurable losses. System R2 introduced operational designs aiming at decreasing DCM volatilization. In Experiment R2.1, a biotrickling filter, through which the air stripped from the CSTR was driven, was introduced leading to a reduction from 10% to 7% on the measurable losses. In Experiment R2.2, the air stripped from the CSTR was recirculated at a flow rate of 2.4 dm3 h−1 through the reactormedium before entering the biotrickling filter. The BE was improved from 69% to 82% and the losses associated with air stripping were successfully reduced to 2%. The proposed design, including air recirculation and the biotrickling filter, increased the ratio between the biodegradation rate and the volatilization rate from 7 to 41. CONCLUSIONS: Recirculation of the gaseous effluent through the reactor medium, which allowed for higher residence time within the bioreactor, was shown to be a successful strategy for improving the treatment process, thus minimizing DCM volatilization losses

    Electric Field Effects on Graphene Materials

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    Understanding the effect of electric fields on the physical and chemical properties of two-dimensional (2D) nanostructures is instrumental in the design of novel electronic and optoelectronic devices. Several of those properties are characterized in terms of the dielectric constant which play an important role on capacitance, conductivity, screening, dielectric losses and refractive index. Here we review our recent theoretical studies using density functional calculations including van der Waals interactions on two types of layered materials of similar two-dimensional molecular geometry but remarkably different electronic structures, that is, graphene and molybdenum disulphide (MoS2_2). We focus on such two-dimensional crystals because of they complementary physical and chemical properties, and the appealing interest to incorporate them in the next generation of electronic and optoelectronic devices. We predict that the effective dielectric constant (ε\varepsilon) of few-layer graphene and MoS2_2 is tunable by external electric fields (EextE_{\rm ext}). We show that at low fields (Eext<0.01E_{\rm ext}^{}<0.01 V/\AA) ε\varepsilon assumes a nearly constant value ∼\sim4 for both materials, but increases at higher fields to values that depend on the layer thickness. The thicker the structure the stronger is the modulation of ε\varepsilon with the electric field. Increasing of the external field perpendicular to the layer surface above a critical value can drive the systems to an unstable state where the layers are weakly coupled and can be easily separated. The observed dependence of ε\varepsilon on the external field is due to charge polarization driven by the bias, which show several similar characteristics despite of the layer considered.Comment: Invited book chapter on Exotic Properties of Carbon Nanomatter: Advances in Physics and Chemistry, Springer Series on Carbon Materials. Editors: Mihai V. Putz and Ottorino Ori (11 pages, 4 figures, 30 references

    Immunoexpression of Trefoil Factor 1 in Non-Neoplastic and Neoplastic Canine Gastric Tissues

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    TFF1 expression is markedly reduced in human GCs, suggesting that TFF1 is a tumor suppressor for human gastric cancer. The present study evaluated the expression and distribution pattern of TFF1 in paraffin-embedded canine gastric tissue samples, including normal mucosa (n = 3), polyps (n = 8), carcinomas (n = 31) and their adjacent non-neoplastic mucosa (n = 30), neoplastic emboli (n = 14), and metastatic lesions (n = 9), by immunohistochemistry (IHC). All normal gastric tissues expressed TFF1 in the superficial foveolar epithelium and mucopeptic cells of the neck region. Most gastric polyps (GPs) displayed immunoreactivity for TFF1 in >75% of the epithelial component. In GCs, the expression of TFF1 was found reduced in 74.2% of the cases. The level of TFF1 expression had a decreased tendency from normal gastric mucosa to GPs and GCs (p 0.05). These findings suggest that TFF1 protein may play a role in canine gastric carcinogenesis, and further studies are necessary to define its usefulness as a prognostic indicator in canine gastric carcinoma.IPATIMUP integrates the i3S Research Unit, which is partially supported by FEDER through the Operational Programme for Competitiveness Factors-COMPETE and National Funds through the Portuguese Foundation for Science and Technology (FCT), under the project number PEst-C/SAU/LA0003/2013. A.R. Flores (SFRH/BD/116373/2016) acknowledges FCT, the Portuguese Foundation for Science and Technology, for financial support. The authors of the research unit CECAV also received funding from the project UIDB/CVT/0772/2020
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