4,738 research outputs found

    A Macroscopic Mathematical Model For Cell Migration Assays Using A Real-Time Cell Analysis

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    Experiments of cell migration and chemotaxis assays have been classically performed in the so-called Boyden Chambers. A recent technology, xCELLigence Real Time Cell Analysis, is now allowing to monitor the cell migration in real time. This technology measures impedance changes caused by the gradual increase of electrode surface occupation by cells during the course of time and provide a Cell Index which is proportional to cellular morphology, spreading, ruffling and adhesion quality as well as cell number. In this paper we propose a macroscopic mathematical model, based on \emph{advection-reaction-diffusion} partial differential equations, describing the cell migration assay using the real-time technology. We carried out numerical simulations to compare simulated model dynamics with data of observed biological experiments on three different cell lines and in two experimental settings: absence of chemotactic signals (basal migration) and presence of a chemoattractant. Overall we conclude that our minimal mathematical model is able to describe the phenomenon in the real time scale and numerical results show a good agreement with the experimental evidences

    AKT1 and AKT2 isoforms play distinct roles during breast cancer progression through the regulation of specific downstream proteins

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    The purpose of this study was to elucidate the mechanisms associated with the specific effects of AKT1 and AKT2 isoforms in breast cancer progression. We modulated the abundance of specific AKT isoforms in IBH-6 and T47D human breast cancer cell lines and showed that AKT1 promoted cell proliferation, through S6 and cyclin D1 upregulation, but it inhibited cell migration and invasion through β1-integrin and focal adhesion kinase (FAK) downregulation. In contrast, AKT2 promoted cell migration and invasion through F-actin and vimentin induction. Thus, while overexpression of AKT1 promoted local tumor growth, downregulation of AKT1 or overexpression of AKT2 promoted peritumoral invasion and lung metastasis. Furthermore, we evaluated The Cancer Genome Atlas (TCGA) dataset for invasive breast carcinomas and found that increased AKT2 but not AKT1 mRNA levels correlated with a worse clinical outcome. We conclude that AKT isoforms play specific roles in different steps of breast cancer progression, with AKT1 involved in the local tumor growth and AKT2 involved in the distant tumor dissemination, having AKT2 a poorer prognostic value and consequently being a worthwhile target for therapy.Fil: Riggio, Marina. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Perrone, Maria Cecilia. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Polo, Maria Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Rodriguez, Maria Jimena. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: May, Maria. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Abba, Martín Carlos. Universidad Nacional de La Plata; ArgentinaFil: Lanari, Claudia Lee Malvina. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Novaro, Virginia. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; Argentin

    Human Pleural Fluid Elicits Pyruvate and Phenylalanine Metabolism in Acinetobacter baumannii to Enhance Cytotoxicity and Immune Evasion

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    The CCAAT box-harboring proteins represent a family of heterotrimeric transcription factors which is highly conserved in eukaryotes. In fungi, one of the particularly important homologs of this family is the Hap complex that separates the DNA-binding domain from the activation domain and imposes essential impacts on regulation of a wide range of cellular functions. So far, a comprehensive summary of this complex has been described in filamentous fungi but not in the yeast. In this review, we summarize a number of studies related to the structure and assembly mode of the Hap complex in a list of representative yeasts. Furthermore, we emphasize recent advances in understanding the regulatory functions of this complex, with a special focus on its role in regulating respiration, production of reactive oxygen species (ROS) and iron homeostasis.Fil: Nyah, Rodman. California State University; Estados UnidosFil: Martinez, Jasmine. California State University; Estados UnidosFil: Fung, Sammie. California State University; Estados UnidosFil: Nakanouchi, Jun. California State University; Estados UnidosFil: Myers, Amber L.. California State University; Estados UnidosFil: Harris, Caitlin M.. California State University; Estados UnidosFil: Dang, Emily. California State University; Estados UnidosFil: Fernandez, Jennifer. California State University; Estados UnidosFil: Liu, Christine. California State University; Estados UnidosFil: Mendoza, Anthony M.. California State University; Estados UnidosFil: Jimenez, VerĂłnica. California State University; Estados UnidosFil: Nikolaidis, Nikolas. California State University; Estados UnidosFil: Brennan, Catherine A.. California State University; Estados UnidosFil: Bonomo, Robert A.. Louis Stokes Cleveland Department of Veterans Affairs Medical Cente; Estados Unidos. Center for Antimicrobial Resistance and Epidemiology; Estados Unidos. Case Western Reserve University School of Medicine; Estados UnidosFil: Sieira, Rodrigo. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Parque Centenario. Instituto de Investigaciones BioquĂ­micas de Buenos Aires. FundaciĂłn Instituto Leloir. Instituto de Investigaciones BioquĂ­micas de Buenos Aires; ArgentinaFil: Ramirez, Maria Soledad. California State University; Estados Unido

    Molecular Predictors of 3D Morphogenesis by Breast Cancer Cell Lines in 3D Culture

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    Correlative analysis of molecular markers with phenotypic signatures is the simplest model for hypothesis generation. In this paper, a panel of 24 breast cell lines was grown in 3D culture, their morphology was imaged through phase contrast microscopy, and computational methods were developed to segment and represent each colony at multiple dimensions. Subsequently, subpopulations from these morphological responses were identified through consensus clustering to reveal three clusters of round, grape-like, and stellate phenotypes. In some cases, cell lines with particular pathobiological phenotypes clustered together (e.g., ERBB2 amplified cell lines sharing the same morphometric properties as the grape-like phenotype). Next, associations with molecular features were realized through (i) differential analysis within each morphological cluster, and (ii) regression analysis across the entire panel of cell lines. In both cases, the dominant genes that are predictive of the morphological signatures were identified. Specifically, PPARÎł has been associated with the invasive stellate morphological phenotype, which corresponds to triple-negative pathobiology. PPARÎł has been validated through two supporting biological assays

    Anisotropy Across Fields and Scales

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    This open access book focuses on processing, modeling, and visualization of anisotropy information, which are often addressed by employing sophisticated mathematical constructs such as tensors and other higher-order descriptors. It also discusses adaptations of such constructs to problems encountered in seemingly dissimilar areas of medical imaging, physical sciences, and engineering. Featuring original research contributions as well as insightful reviews for scientists interested in handling anisotropy information, it covers topics such as pertinent geometric and algebraic properties of tensors and tensor fields, challenges faced in processing and visualizing different types of data, statistical techniques for data processing, and specific applications like mapping white-matter fiber tracts in the brain. The book helps readers grasp the current challenges in the field and provides information on the techniques devised to address them. Further, it facilitates the transfer of knowledge between different disciplines in order to advance the research frontiers in these areas. This multidisciplinary book presents, in part, the outcomes of the seventh in a series of Dagstuhl seminars devoted to visualization and processing of tensor fields and higher-order descriptors, which was held in Dagstuhl, Germany, on October 28–November 2, 2018

    Antropometrijske razlike romske i neromske novorođenčadi u Virovitičko-podravskoj županiji

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    The aim of this work is to assess anthropometric parameters of the Roma newborns in Virovitica-Podravina County and compare them with the values for the non-Roma group. This retrospective investigation includes 204 Roma and 408 non-Roma newborns, born at the maternity ward of the Virovitica General Hospital in the period from 1991 to 2010. Various parameters, such as birth weight and length, head perimeter, as well as the ponderal index and percentile values of birth weight, were assessed. Roma newborns have, on average, 321.7 g smaller weight, 1.3 cm smaller length and 0.7 cm smaller head perimeter at birth, compared to non-Roma newborns. The ponderal index was found to be 0.06 less for Roma newborns, with higher frequency of hypothrophic newborns, according to the percentile values of the birth weight. The differences in anthropometric parameter values of Roma and non-Roma newborns may be due to the ethnic identity, but also due to the impact of the surroundings and the lifestyle of the population itself. Assessed data could provide a better understanding to, and political direction for the improvement of the reproductive, as well as the overall health of the Roma population.Cilj je ovog rada prikazati antropometrijske vrijednosti romske novorođenčadi u Virovitičko-podravskoj županiji i usporediti ih s većinskom neromskom skupinom. Retrospektivno istraživanje obuhvatilo je 204 romske i 408 neromske novorođenčadi, rođene u rodilištu Opće bolnice Virovitica u razdoblju od 1991. do 2010. godine. Analizirani su podaci o porođajnim težinama, duljinama i opsegu glave novorođenčadi te ponderalnom indeksu i centilnim vrijednostima porođajne težine. Romska novorođenčad po porođaju ima prosječno 321,7 g manju težinu, 1,3 cm manju duljinu i 0,7 cm manji opseg glave u odnosu na neromsku novorođenčad. Značajne su razlike u ponderalnom indeksu koji je za 0,06 manji kod romske novorođenčadi, kao i u centilnim vrijednostima porođajne težine s većom učestalosti kategorije hipotrofične novorođenčadi. Razlike antropometrijskih vrijednostima romske i neromske novorođenčadi mogu se objasniti utjecajem etničke pripadnosti, ali i utjecajem okoline i životnog stila populacije. Prikupljeni podaci mogu pridonijeti boljem razumijevanju i razvoju politike usmjerene poboljšanju reproduktivnog i cjelokupnog zdravlja romske populacije

    Quantification of total fetal brain volume using 3D MR imaging data acquired in utero.

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    Objective: Interpretation of magnetic resonance (MR) imaging of the fetal brain in utero is primarily undertaken using 2D images to provide anatomical information about structural abnormalities. It is now possible to obtain 3D image acquisitions that allow measurement of fetal brain volumes that are potentially useful clinically. The aim of our current work is to provide reference values of total brain volumes obtained from a cohort of low risk fetuses with no abnormalities on ante-natal ultrasonography and in utero MR imaging. Method: Images from volume MR acquisitions of 132 fetuses were used to extract brain volumes by manual segmentation. Reproducibility and reliability were assessed by analysis of the results of two subgroups who had repeated measurements made by the primary and a secondary observer. Results: Intra-observer and inter-observer agreement was high with no statistically significant differences between and within observers (p = 0.476 and p = 0.427, respectively). The results of the brain volume assessments are presented graphically with mean and 95% prediction limits alongside estimates of normal growth rates. Conclusion: We have shown that fetal brain volumes can be reliably extracted from in utero MR (iuMR) imaging 3D datasets with a high degree of reproducibility. The resultant data could potentially be used as a reference tool in the clinical setting

    Circulating mRNAs are differentially expressed in pregnancies with severe placental insufficiency and at high risk of stillbirth

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    Background Fetuses affected by placental insufficiency do not receive adequate nutrients and oxygenation, become growth restricted and acidemic, and can demise. Preterm fetal growth restriction is a severe form of placental insufficiency with a high risk of stillbirth. We set out to identify maternal circulating mRNA transcripts that are differentially expressed in preterm pregnancies complicated by very severe placental insufficiency, in utero fetal acidemia, and are at very high risk of stillbirth. Methods We performed a cohort study across six hospitals in Australia and New Zealand, prospectively collecting blood from 128 pregnancies complicated by preterm fetal growth restriction (delivery < 34 weeks’ gestation) and 42 controls. RNA-sequencing was done on all samples to discover circulating mRNAs associated with preterm fetal growth restriction and fetal acidemia in utero. We used RT-PCR to validate the associations between five lead candidate biomarkers of placental insufficiency in an independent cohort from Europe (46 with preterm fetal growth restriction) and in a third cohort of pregnancies ending in stillbirth. Results In the Australia and New Zealand cohort, we identified five mRNAs that were highly differentially expressed among pregnancies with preterm fetal growth restriction: NR4A2, EMP1, PGM5, SKIL, and UGT2B1. Combining three yielded an area under the receiver operative curve (AUC) of 0.95. Circulating NR4A2 and RCBTB2 in the maternal blood were dysregulated in the presence of fetal acidemia in utero. We validated the association between preterm fetal growth restriction and circulating EMP1, NR4A2, and PGM5 mRNA in a cohort from Europe. Combining EMP1 and PGM5 identified fetal growth restriction with an AUC of 0.92. Several of these genes were differentially expressed in the presence of ultrasound parameters that reflect placental insufficiency. Circulating NR4A2, EMP1, and RCBTB2 mRNA were differentially regulated in another cohort destined for stillbirth, compared to ongoing pregnancies. EMP1 mRNA appeared to have the most consistent association with placental insufficiency in all cohorts. Conclusions Measuring circulating mRNA offers potential as a test to identify pregnancies with severe placental insufficiency and at very high risk of stillbirth. Circulating mRNA EMP1 may be promising as a biomarker of severe placental insufficiency

    Anisotropy Across Fields and Scales

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    This open access book focuses on processing, modeling, and visualization of anisotropy information, which are often addressed by employing sophisticated mathematical constructs such as tensors and other higher-order descriptors. It also discusses adaptations of such constructs to problems encountered in seemingly dissimilar areas of medical imaging, physical sciences, and engineering. Featuring original research contributions as well as insightful reviews for scientists interested in handling anisotropy information, it covers topics such as pertinent geometric and algebraic properties of tensors and tensor fields, challenges faced in processing and visualizing different types of data, statistical techniques for data processing, and specific applications like mapping white-matter fiber tracts in the brain. The book helps readers grasp the current challenges in the field and provides information on the techniques devised to address them. Further, it facilitates the transfer of knowledge between different disciplines in order to advance the research frontiers in these areas. This multidisciplinary book presents, in part, the outcomes of the seventh in a series of Dagstuhl seminars devoted to visualization and processing of tensor fields and higher-order descriptors, which was held in Dagstuhl, Germany, on October 28–November 2, 2018
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