Recapitulation of physiological spatiotemporal signals promotes in vitro formation of phenotypically stable human articular cartilage

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Wei, Yiyong; Zhou, Bin; Bernhard, Jonathan; Robinson, Samuel; Burapachaisri, Aonnicha; Guo, X. Edward

2017-01-01

Standard isotropic culture fails to recapitulate the spatiotemporal gradients present during native development. Cartilage grown from human mesenchymal stem cells (hMSCs) is poorly organized and unstable in vivo. We report that human cartilage with physiologic organization and in vivo stability can be grown in vitro from self-assembling hMSCs by implementing spatiotemporal regulation during induction. Self-assembling hMSCs formed cartilage discs in Transwell inserts following isotropic chondrogenic induction with transforming growth factor β to set up a dual-compartment culture. Following a switch in the basal compartment to a hypertrophic regimen with thyroxine, the cartilage discs underwent progressive deep-zone hypertrophy and mineralization. Concurrent chondrogenic induction in the apical compartment enabled the maintenance of functional and hyaline cartilage. Cartilage homeostasis, chondrocyte maturation, and terminal differentiation markers were all up-regulated versus isotropic control groups. We assessed the in vivo stability of the cartilage formed under different induction regimens. Cartilage formed under spatiotemporal regulation in vitro resisted endochondral ossification, retained the expression of cartilage markers, and remained organized following s.c. implantation in immunocompromised mice. In contrast, the isotropic control groups underwent endochondral ossification. Cartilage formed from hMSCs remained stable and organized in vivo. Spatiotemporal regulation during induction in vitro recapitulated some aspects of native cartilage development, and potentiated the maturation of self-assembling hMSCs into stable and organized cartilage resembling the native articular cartilage. PMID:28228529

Recapitulative list of the C.E.A. reports published by the French Atomic Energy Commission (n.757-1062, december 1957-december 1958) supplement to C.E.A. reports n. 593 and 756; Liste recapitulative des rapports C.E.A. publies par le Commissariat a l'Energie Atomique (du n.757 a 1062, decembre 1957-decembre 1958) complement aux rapports C.E.A. n. 593 et 756

Energy Technology Data Exchange (ETDEWEB)

Schmiterlow, C G; Cohen, Y [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1958-07-01

Recapitulative list of the C.E.A. reports published by the French Atomic Energy Commission. (number 757-1062, december 1957 - december 1958). Supplement to C.E.A. reports number 593 and 756. (author) [French] Liste recapitulative des rapports C.E.A. publies par le Commissariat a l'Energie Atomique (du numero 757 au numero 1062, decembre 1957 - decembre 1958). Complement aux rapports C.E.A. numero 593 et 756. (auteur)

Recapitulation of tumor heterogeneity and molecular signatures in a 3D brain cancer model with decreased sensitivity to histone deacetylase inhibition.

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Stuart J Smith

Full Text Available INTRODUCTION: Physiologically relevant pre-clinical ex vivo models recapitulating CNS tumor micro-environmental complexity will aid development of biologically-targeted agents. We present comprehensive characterization of tumor aggregates generated using the 3D Rotary Cell Culture System (RCCS. METHODS: CNS cancer cell lines were grown in conventional 2D cultures and the RCCS and comparison with a cohort of 53 pediatric high grade gliomas conducted by genome wide gene expression and microRNA arrays, coupled with immunohistochemistry, ex vivo magnetic resonance spectroscopy and drug sensitivity evaluation using the histone deacetylase inhibitor, Vorinostat. RESULTS: Macroscopic RCCS aggregates recapitulated the heterogeneous morphology of brain tumors with a distinct proliferating rim, necrotic core and oxygen tension gradient. Gene expression and microRNA analyses revealed significant differences with 3D expression intermediate to 2D cultures and primary brain tumors. Metabolic profiling revealed differential profiles, with an increase in tumor specific metabolites in 3D. To evaluate the potential of the RCCS as a drug testing tool, we determined the efficacy of Vorinostat against aggregates of U87 and KNS42 glioblastoma cells. Both lines demonstrated markedly reduced sensitivity when assaying in 3D culture conditions compared to classical 2D drug screen approaches. CONCLUSIONS: Our comprehensive characterization demonstrates that 3D RCCS culture of high grade brain tumor cells has profound effects on the genetic, epigenetic and metabolic profiles of cultured cells, with these cells residing as an intermediate phenotype between that of 2D cultures and primary tumors. There is a discrepancy between 2D culture and tumor molecular profiles, and RCCS partially re-capitulates tissue specific features, allowing drug testing in a more relevant ex vivo system.

A hamster model for Marburg virus infection accurately recapitulates Marburg hemorrhagic fever.

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Marzi, Andrea; Banadyga, Logan; Haddock, Elaine; Thomas, Tina; Shen, Kui; Horne, Eva J; Scott, Dana P; Feldmann, Heinz; Ebihara, Hideki

2016-12-15

Marburg virus (MARV), a close relative of Ebola virus, is the causative agent of a severe human disease known as Marburg hemorrhagic fever (MHF). No licensed vaccine or therapeutic exists to treat MHF, and MARV is therefore classified as a Tier 1 select agent and a category A bioterrorism agent. In order to develop countermeasures against this severe disease, animal models that accurately recapitulate human disease are required. Here we describe the development of a novel, uniformly lethal Syrian golden hamster model of MHF using a hamster-adapted MARV variant Angola. Remarkably, this model displayed almost all of the clinical features of MHF seen in humans and non-human primates, including coagulation abnormalities, hemorrhagic manifestations, petechial rash, and a severely dysregulated immune response. This MHF hamster model represents a powerful tool for further dissecting MARV pathogenesis and accelerating the development of effective medical countermeasures against human MHF.

Back to basics: the untreated rabbit reticulocyte lysate as a competitive system to recapitulate cap/poly(A) synergy and the selective advantage of IRES-driven translation.

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Soto Rifo, Ricardo; Ricci, Emiliano P; Décimo, Didier; Moncorgé, Olivier; Ohlmann, Théophile

2007-01-01

Translation of most eukaryotic mRNAs involves the synergistic action between the 5' cap structure and the 3' poly(A) tail at the initiation step. The poly(A) tail has also been shown to stimulate translation of picornavirus internal ribosome entry sites (IRES)-directed translation. These effects have been attributed principally to interactions between eIF4G and poly(A)-binding protein (PABP) but also to the participation of PABP in other steps during translation initiation. As the rabbit reticulocyte lysate (RRL) does not recapitulate this cap/poly(A) synergy, several systems based on cellular cell-free extracts have been developed to study the effects of poly(A) tail in vitro but they generally exhibit low translational efficiency. Here, we describe that the non-nuclease-treated RRL (untreated RRL) is able to recapitulate the effects of poly(A) tail on translation in vitro. In this system, translation of a capped/polyadenylated RNA was specifically inhibited by either Paip2 or poly(rA), whereas translation directed by HCV IRES remained unaffected. Moreover, cleavage of eIF4G by FMDV L protease strongly stimulated translation directed by the EMCV IRES, thus recapitulating the competitive advantage that the proteolytic processing of eIF4G confers to IRES-driven RNAs.

Targeting Hypoxia-Inducible Factor 1α in a New Orthotopic Model of Glioblastoma Recapitulating the Hypoxic Tumor Microenvironment.

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Nigim, Fares; Cavanaugh, Jill; Patel, Anoop P; Curry, William T; Esaki, Shin-ichi; Kasper, Ekkehard M; Chi, Andrew S; Louis, David N; Martuza, Robert L; Rabkin, Samuel D; Wakimoto, Hiroaki

2015-07-01

Tissue hypoxia and necrosis represent pathophysiologic and histologic hallmarks of glioblastoma (GBM). Although hypoxia inducible factor 1α (HIF-1α) plays crucial roles in the malignant phenotypes of GBM, developing HIF-1α-targeted agents has been hampered by the lack of a suitable preclinical model that recapitulates the complex biology of clinical GBM. We present a new GBM model, MGG123, which was established from a recurrent human GBM. Orthotopic xenografting of stem-like MGG123 cells reproducibly generated lethal tumors that were characterized by foci of palisading necrosis, hypervascularity, and robust stem cell marker expression. Perinecrotic neoplastic cells distinctively express HIF-1α and are proliferative in both xenografts and the patient tissue. The xenografts contain scattered hypoxic foci that were consistently greater than 50 μm distant from blood vessels, indicating intratumoral heterogeneity of oxygenation. Hypoxia enhanced HIF-1α expression in cultured MGG123 cells, which was abrogated by the HIF-1α inhibitors digoxin or ouabain. In vivo, treatment of orthotopic MGG123 xenografts with digoxin decreased HIF-1α expression, vascular endothelial growth factor mRNA levels, and CD34-positive vasculature within the tumors, and extended survival of mice bearing the aggressive MGG123 GBM. This preclinical tumor model faithfully recapitulates the GBM-relevant hypoxic microenvironment and stemness and is a suitable platform for studying disease biology and developing hypoxia-targeted agents.

Recapitulation of Clinical Individual Susceptibility to Drug-Induced QT Prolongation in Healthy Subjects Using iPSC-Derived Cardiomyocytes

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Tadahiro Shinozawa

2017-02-01

Full Text Available To predict drug-induced serious adverse events (SAE in clinical trials, a model using a panel of cells derived from human induced pluripotent stem cells (hiPSCs of individuals with different susceptibilities could facilitate major advancements in translational research in terms of safety and pharmaco-economics. However, it is unclear whether hiPSC-derived cells can recapitulate interindividual differences in drug-induced SAE susceptibility in populations not having genetic disorders such as healthy subjects. Here, we evaluated individual differences in SAE susceptibility based on an in vitro model using hiPSC-derived cardiomyocytes (hiPSC-CMs as a pilot study. hiPSCs were generated from blood samples of ten healthy volunteers with different susceptibilities to moxifloxacin (Mox-induced QT prolongation. Different Mox-induced field potential duration (FPD prolongation values were observed in the hiPSC-CMs from each individual. Interestingly, the QT interval was significantly positively correlated with FPD at clinically relevant concentrations (r > 0.66 in multiple analyses including concentration-QT analysis. Genomic analysis showed no interindividual significant differences in known target-binding sites for Mox and other drugs such as the hERG channel subunit, and baseline QT ranges were normal. The results suggest that hiPSC-CMs from healthy subjects recapitulate susceptibility to Mox-induced QT prolongation and provide proof of concept for in vitro preclinical trials.

Substoichiometric hydroxynonenylation of a single protein recapitulates whole-cell-stimulated antioxidant response.

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Parvez, Saba; Fu, Yuan; Li, Jiayang; Long, Marcus J C; Lin, Hong-Yu; Lee, Dustin K; Hu, Gene S; Aye, Yimon

2015-01-14

Lipid-derived electrophiles (LDEs) that can directly modify proteins have emerged as important small-molecule cues in cellular decision-making. However, because these diffusible LDEs can modify many targets [e.g., >700 cysteines are modified by the well-known LDE 4-hydroxynonenal (HNE)], establishing the functional consequences of LDE modification on individual targets remains devilishly difficult. Whether LDE modifications on a single protein are biologically sufficient to activate discrete redox signaling response downstream also remains untested. Herein, using T-REX (targetable reactive electrophiles and oxidants), an approach aimed at selectively flipping a single redox switch in cells at a precise time, we show that a modest level (∼34%) of HNEylation on a single target is sufficient to elicit the pharmaceutically important antioxidant response element (ARE) activation, and the resultant strength of ARE induction recapitulates that observed from whole-cell electrophilic perturbation. These data provide the first evidence that single-target LDE modifications are important individual events in mammalian physiology.

Three-Dimensional Printing Articular Cartilage: Recapitulating the Complexity of Native Tissue.

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Guo, Ting; Lembong, Josephine; Zhang, Lijie Grace; Fisher, John P

2017-06-01

In the past few decades, the field of tissue engineering combined with rapid prototyping (RP) techniques has been successful in creating biological substitutes that mimic tissues. Its applications in regenerative medicine have drawn efforts in research from various scientific fields, diagnostics, and clinical translation to therapies. While some areas of therapeutics are well developed, such as skin replacement, many others such as cartilage repair can still greatly benefit from tissue engineering and RP due to the low success and/or inefficiency of current existing, often surgical treatments. Through fabrication of complex scaffolds and development of advanced materials, RP provides a new avenue for cartilage repair. Computer-aided design and three-dimensional (3D) printing allow the fabrication of modeled cartilage scaffolds for repair and regeneration of damaged cartilage tissues. Specifically, the various processes of 3D printing will be discussed in details, both cellular and acellular techniques, covering the different materials, geometries, and operational printing conditions for the development of tissue-engineered articular cartilage. Finally, we conclude with some insights on future applications and challenges related to this technology, especially using 3D printing techniques to recapitulate the complexity of native structure for advanced cartilage regeneration.

Ablation of fast-spiking interneurons in the dorsal striatum, recapitulating abnormalities seen post-mortem in Tourette syndrome, produces anxiety and elevated grooming.

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Xu, M; Li, L; Pittenger, C

2016-06-02

Tic disorders, including Tourette syndrome (TS), are thought to involve pathology of cortico-basal ganglia loops, but their pathology is not well understood. Post-mortem studies have shown a reduced number of several populations of striatal interneurons, including the parvalbumin-expressing fast-spiking interneurons (FSIs), in individuals with severe, refractory TS. We tested the causal role of this interneuronal deficit by recapitulating it in an otherwise normal adult mouse using a combination transgenic-viral cell ablation approach. FSIs were reduced bilaterally by ∼40%, paralleling the deficit found post-mortem. This did not produce spontaneous stereotypies or tic-like movements, but there was increased stereotypic grooming after acute stress in two validated paradigms. Stereotypy after amphetamine, in contrast, was not elevated. FSI ablation also led to increased anxiety-like behavior in the elevated plus maze, but not to alterations in motor learning on the rotorod or to alterations in prepulse inhibition, a measure of sensorimotor gating. These findings indicate that a striatal FSI deficit can produce stress-triggered repetitive movements and anxiety. These repetitive movements may recapitulate aspects of the pathophysiology of tic disorders. Copyright © 2016 IBRO. Published by Elsevier Ltd. All rights reserved.

A Novel Letrozole Model Recapitulates Both the Reproductive and Metabolic Phenotypes of Polycystic Ovary Syndrome in Female Mice1

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Kauffman, Alexander S.; Thackray, Varykina G.; Ryan, Genevieve E.; Tolson, Kristen P.; Glidewell-Kenney, Christine A.; Semaan, Sheila J.; Poling, Matthew C.; Iwata, Nahoko; Breen, Kellie M.; Duleba, Antoni J.; Stener-Victorin, Elisabet; Shimasaki, Shunichi; Webster, Nicholas J.; Mellon, Pamela L.

2015-01-01

Polycystic ovary syndrome (PCOS) pathophysiology is poorly understood, due partly to lack of PCOS animal models fully recapitulating this complex disorder. Recently, a PCOS rat model using letrozole (LET), a nonsteroidal aromatase inhibitor, mimicked multiple PCOS phenotypes, including metabolic features absent in other models. Given the advantages of using genetic and transgenic mouse models, we investigated whether LET produces a similar PCOS phenotype in mice. Pubertal female C57BL/6N mice were treated for 5 wk with LET, which resulted in increased serum testosterone and normal diestrus levels of estradiol, similar to the hyperandrogenemia and follicular phase estrogen levels of PCOS women. As in PCOS, ovaries from LET mice were larger, polycystic, and lacked corpora lutea versus controls. Most LET females were acyclic, and all were infertile. LET females displayed elevated serum LH levels and higher Lhb mRNA in the pituitary. In contrast, serum FSH and Fshb were significantly reduced in LET females, demonstrating differential effects on gonadotropins, as in PCOS. Within the ovary, LET females had higher Cyp17, Cyp19, and Fsh receptor mRNA expression. In the hypothalamus, LET females had higher kisspeptin receptor mRNA expression but lower progesterone receptor mRNA levels. LET females also gained more weight than controls, had increased abdominal adiposity and adipocyte size, elevated adipose inflammatory mRNA levels, and impaired glucose tolerance, mirroring the metabolic phenotype in PCOS women. This is the first report of a LET paradigm in mice that recapitulates both reproductive and metabolic PCOS phenotypes and will be useful to genetically probe the PCOS condition. PMID:26203175

Recapitulating phylogenies using k-mers: from trees to networks.

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Bernard, Guillaume; Ragan, Mark A; Chan, Cheong Xin

2016-01-01

Ernst Haeckel based his landmark Tree of Life on the supposed ontogenic recapitulation of phylogeny, i.e. that successive embryonic stages during the development of an organism re-trace the morphological forms of its ancestors over the course of evolution. Much of this idea has since been discredited. Today, phylogenies are often based on families of molecular sequences. The standard approach starts with a multiple sequence alignment, in which the sequences are arranged relative to each other in a way that maximises a measure of similarity position-by-position along their entire length. A tree (or sometimes a network) is then inferred. Rigorous multiple sequence alignment is computationally demanding, and evolutionary processes that shape the genomes of many microbes (bacteria, archaea and some morphologically simple eukaryotes) can add further complications. In particular, recombination, genome rearrangement and lateral genetic transfer undermine the assumptions that underlie multiple sequence alignment, and imply that a tree-like structure may be too simplistic. Here, using genome sequences of 143 bacterial and archaeal genomes, we construct a network of phylogenetic relatedness based on the number of shared k -mers (subsequences at fixed length k ). Our findings suggest that the network captures not only key aspects of microbial genome evolution as inferred from a tree, but also features that are not treelike. The method is highly scalable, allowing for investigation of genome evolution across a large number of genomes. Instead of using specific regions or sequences from genome sequences, or indeed Haeckel's idea of ontogeny, we argue that genome phylogenies can be inferred using k -mers from whole-genome sequences. Representing these networks dynamically allows biological questions of interest to be formulated and addressed quickly and in a visually intuitive manner.

Selective Activation of mTORC1 Signaling Recapitulates Microcephaly, Tuberous Sclerosis, and Neurodegenerative Diseases

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Hidetoshi Kassai

2014-06-01

Full Text Available Mammalian target of rapamycin (mTOR has been implicated in human neurological diseases such as tuberous sclerosis complex (TSC, neurodegeneration, and autism. However, little is known about when and how mTOR is involved in the pathogenesis of these diseases, due to a lack of animal models that directly increase mTOR activity. Here, we generated transgenic mice expressing a gain-of-function mutant of mTOR in the forebrain in a temporally controlled manner. Selective activation of mTORC1 in embryonic stages induced cortical atrophy caused by prominent apoptosis of neuronal progenitors, associated with upregulation of HIF-1α. In striking contrast, activation of the mTORC1 pathway in adulthood resulted in cortical hypertrophy with fatal epileptic seizures, recapitulating human TSC. Activated mTORC1 in the adult cortex also promoted rapid accumulation of cytoplasmic inclusions and activation of microglial cells, indicative of progressive neurodegeneration. Our findings demonstrate that mTORC1 plays different roles in developmental and adult stages and contributes to human neurological diseases.

Modeling the autistic cell: iPSCs recapitulate developmental principles of syndromic and nonsyndromic ASD.

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Ben-Reuven, Lihi; Reiner, Orly

2016-06-01

The opportunity to model autism spectrum disorders (ASD) through generation of patient-derived induced pluripotent stem cells (iPSCs) is currently an emerging topic. Wide-scale research of altered brain circuits in syndromic ASD, including Rett Syndrome, Fragile X Syndrome, Angelman's Syndrome and sporadic Schizophrenia, was made possible through animal models. However, possibly due to species differences, and to the possible contribution of epigenetics in the pathophysiology of these diseases, animal models fail to recapitulate many aspects of ASD. With the advent of iPSCs technology, 3D cultures of patient-derived cells are being used to study complex neuronal phenotypes, including both syndromic and nonsyndromic ASD. Here, we review recent advances in using iPSCs to study various aspects of the ASD neuropathology, with emphasis on the efforts to create in vitro model systems for syndromic and nonsyndromic ASD. We summarize the main cellular activity phenotypes and aberrant genetic interaction networks that were found in iPSC-derived neurons of syndromic and nonsyndromic autistic patients. © 2016 Japanese Society of Developmental Biologists.

Recapitulative list of the C.E.A. reports published by the French Atomic Energy Commission (n.757-1062, december 1957-december 1958) supplement to C.E.A. reports n. 593 and 756

International Nuclear Information System (INIS)

Schmiterlow, C.G.; Cohen, Y.

1958-01-01

Recapitulative list of the C.E.A. reports published by the French Atomic Energy Commission. (number 757-1062, december 1957 - december 1958). Supplement to C.E.A. reports number 593 and 756. (author) [fr

Systematic Three-Dimensional Coculture Rapidly Recapitulates Interactions between Human Neurons and Astrocytes

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Robert Krencik

2017-12-01

Full Text Available Summary: Human astrocytes network with neurons in dynamic ways that are still poorly defined. Our ability to model this relationship is hampered by the lack of relevant and convenient tools to recapitulate this complex interaction. To address this barrier, we have devised efficient coculture systems utilizing 3D organoid-like spheres, termed asteroids, containing pre-differentiated human pluripotent stem cell (hPSC-derived astrocytes (hAstros combined with neurons generated from hPSC-derived neural stem cells (hNeurons or directly induced via Neurogenin 2 overexpression (iNeurons. Our systematic methods rapidly produce structurally complex hAstros and synapses in high-density coculture with iNeurons in precise numbers, allowing for improved studies of neural circuit function, disease modeling, and drug screening. We conclude that these bioengineered neural circuit model systems are reliable and scalable tools to accurately study aspects of human astrocyte-neuron functional properties while being easily accessible for cell-type-specific manipulations and observations. : In this article, Krencik and colleagues show that high-density cocultures of pre-differentiated human astrocytes with induced neurons, from pluripotent stem cells, elicit mature characteristics by 3–5 weeks. This provides a faster and more defined alternative method to organoid cultures for investigating human neural circuit function. Keywords: human pluripotent stem cells, neurons, astrocytes, synapses, coculture, three-dimensional spheres, organoids, disease modeling

Journal of Genetics | Indian Academy of Sciences

Indian Academy of Sciences (India)

Home; Journals; Journal of Genetics. L. S. Shashidhara. Articles written in Journal of Genetics. Volume 79 Issue 2 August 2000 pp 61-70. Negative regulation of Ultrabithorax expression by engrailed is required for proper specification of wing development in Drosophila melanogaster · B. Starling Emerald L. S. Shashidhara.

Transgenic Monkey Model of the Polyglutamine Diseases Recapitulating Progressive Neurological Symptoms

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Ishibashi, Hidetoshi; Minakawa, Eiko N.; Motohashi, Hideyuki H.; Takayama, Osamu; Popiel, H. Akiko; Puentes, Sandra; Owari, Kensuke; Nakatani, Terumi; Nogami, Naotake; Yamamoto, Kazuhiro; Yonekawa, Takahiro; Tanaka, Yoko; Fujita, Naoko; Suzuki, Hikaru; Aizawa, Shu; Nagano, Seiichi; Yamada, Daisuke; Wada, Keiji; Kohsaka, Shinichi

2017-01-01

Abstract Age-associated neurodegenerative diseases, such as Alzheimer’s disease, Parkinson’s disease, and the polyglutamine (polyQ) diseases, are becoming prevalent as a consequence of elongation of the human lifespan. Although various rodent models have been developed to study and overcome these diseases, they have limitations in their translational research utility owing to differences from humans in brain structure and function and in drug metabolism. Here, we generated a transgenic marmoset model of the polyQ diseases, showing progressive neurological symptoms including motor impairment. Seven transgenic marmosets were produced by lentiviral introduction of the human ataxin 3 gene with 120 CAG repeats encoding an expanded polyQ stretch. Although all offspring showed no neurological symptoms at birth, three marmosets with higher transgene expression developed neurological symptoms of varying degrees at 3–4 months after birth, followed by gradual decreases in body weight gain, spontaneous activity, and grip strength, indicating time-dependent disease progression. Pathological examinations revealed neurodegeneration and intranuclear polyQ protein inclusions accompanied by gliosis, which recapitulate the neuropathological features of polyQ disease patients. Consistent with neuronal loss in the cerebellum, brain MRI analyses in one living symptomatic marmoset detected enlargement of the fourth ventricle, which suggests cerebellar atrophy. Notably, successful germline transgene transmission was confirmed in the second-generation offspring derived from the symptomatic transgenic marmoset gamete. Because the accumulation of abnormal proteins is a shared pathomechanism among various neurodegenerative diseases, we suggest that this new marmoset model will contribute toward elucidating the pathomechanisms of and developing clinically applicable therapies for neurodegenerative diseases. PMID:28374014

Advanced biomaterials and microengineering technologies to recapitulate the stepwise process of cancer metastasis.

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Peela, Nitish; Truong, Danh; Saini, Harpinder; Chu, Hunghao; Mashaghi, Samaneh; Ham, Stephanie L; Singh, Sunil; Tavana, Hossein; Mosadegh, Bobak; Nikkhah, Mehdi

2017-07-01

Cancer is one of the leading causes of death globally according to the World Health Organization. Although improved treatments and early diagnoses have reduced cancer related mortalities, metastatic disease remains a major clinical challenge. The local tumor microenvironment plays a significant role in cancer metastasis, where tumor cells respond and adapt to a plethora of biochemical and biophysical signals from stromal cells and extracellular matrix (ECM) proteins. Due to these complexities, there is a critical need to understand molecular mechanisms underlying cancer metastasis to facilitate the discovery of more effective therapies. In the past few years, the integration of advanced biomaterials and microengineering approaches has initiated the development of innovative platform technologies for cancer research. These technologies enable the creation of biomimetic in vitro models with physiologically relevant (i.e. in vivo-like) characteristics to conduct studies ranging from fundamental cancer biology to high-throughput drug screening. In this review article, we discuss the biological significance of each step of the metastatic cascade and provide a broad overview on recent progress to recapitulate these stages using advanced biomaterials and microengineered technologies. In each section, we will highlight the advantages and shortcomings of each approach and provide our perspectives on future directions. Copyright © 2017 Elsevier Ltd. All rights reserved.

Bioengineered Systems and Designer Matrices That Recapitulate the Intestinal Stem Cell Niche

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Yuli Wang

2018-01-01

Full Text Available The relationship between intestinal stem cells (ISCs and the surrounding niche environment is complex and dynamic. Key factors localized at the base of the crypt are necessary to promote ISC self-renewal and proliferation, to ultimately provide a constant stream of differentiated cells to maintain the epithelial barrier. These factors diminish as epithelial cells divide, migrate away from the crypt base, differentiate into the postmitotic lineages, and end their life span in approximately 7 days when they are sloughed into the intestinal lumen. To facilitate the rapid and complex physiology of ISC-driven epithelial renewal, in vivo gradients of growth factors, extracellular matrix, bacterial products, gases, and stiffness are formed along the crypt-villus axis. New bioengineered tools and platforms are available to recapitulate various gradients and support the stereotypical cellular responses associated with these gradients. Many of these technologies have been paired with primary small intestinal and colonic epithelial cells to re-create select aspects of normal physiology or disease states. These biomimetic platforms are becoming increasingly sophisticated with the rapid discovery of new niche factors and gradients. These advancements are contributing to the development of high-fidelity tissue constructs for basic science applications, drug screening, and personalized medicine applications. Here, we discuss the direct and indirect evidence for many of the important gradients found in vivo and their successful application to date in bioengineered in vitro models, including organ-on-chip and microfluidic culture devices.

A Human Neural Crest Stem Cell-Derived Dopaminergic Neuronal Model Recapitulates Biochemical Abnormalities in GBA1 Mutation Carriers

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Shi-Yu Yang

2017-03-01

Full Text Available Numerically the most important risk factor for the development of Parkinson's disease (PD is the presence of mutations in the glucocerebrosidase GBA1 gene. In vitro and in vivo studies show that GBA1 mutations reduce glucocerebrosidase (GCase activity and are associated with increased α-synuclein levels, reflecting similar changes seen in idiopathic PD brain. We have developed a neural crest stem cell-derived dopaminergic neuronal model that recapitulates biochemical abnormalities in GBA1 mutation-associated PD. Cells showed reduced GCase protein and activity, impaired macroautophagy, and increased α-synuclein levels. Advantages of this approach include easy access to stem cells, no requirement to reprogram, and retention of the intact host genome. Treatment with a GCase chaperone increased GCase protein levels and activity, rescued the autophagic defects, and decreased α-synuclein levels. These results provide the basis for further investigation of GCase chaperones or similar drugs to slow the progression of PD.

Recapitulating cortical development with organoid culture in vitro and modeling abnormal spindle-like (ASPM related primary) microcephaly disease

Institute of Scientific and Technical Information of China (English)

Rui Li; Le Sun; Ai Fang; Peng Li; Qian Wu; Xiaoqun Wang

2017-01-01

The development of a cerebral organoid culture in vitro offers an opportunity to generate human brain-like organs to investigate mechanisms of human disease that are specific to the neurogenesis of radial glial (RG) and outer radial glial (oRG) cells in the ventricular zone (VZ) and subventricular zone (SVZ) of the developing neocortex.Modeling neuronal progenitors and the organization that produces mature subcortical neuron subtypes during early stages of development is essential for studying human brain developmental diseases.Several previous efforts have shown to grow neural organoid in culture dishes successfully,however we demonstrate a new paradigm that recapitulates neocortical development process with VZ,OSVZ formation and the lamination organization of cortical layer structure.In addition,using patient-specific induced pluripotent stem cells (iPSCs) with dysfunction of the Aspm gene from a primary microcephaly patient,we demonstrate neurogenesis defects result in defective neuronal activity in patient organoids,suggesting a new strategy to study human developmental diseases in central nerve system.

A data-driven weighting scheme for multivariate phenotypic endpoints recapitulates zebrafish developmental cascades

Energy Technology Data Exchange (ETDEWEB)

Zhang, Guozhu, E-mail: gzhang6@ncsu.edu [Bioinformatics Research Center, North Carolina State University, Raleigh, NC (United States); Roell, Kyle R., E-mail: krroell@ncsu.edu [Bioinformatics Research Center, North Carolina State University, Raleigh, NC (United States); Truong, Lisa, E-mail: lisa.truong@oregonstate.edu [Department of Environmental and Molecular Toxicology, Sinnhuber Aquatic Research Laboratory, Oregon State University, Corvallis, OR (United States); Tanguay, Robert L., E-mail: robert.tanguay@oregonstate.edu [Department of Environmental and Molecular Toxicology, Sinnhuber Aquatic Research Laboratory, Oregon State University, Corvallis, OR (United States); Reif, David M., E-mail: dmreif@ncsu.edu [Bioinformatics Research Center, North Carolina State University, Raleigh, NC (United States); Department of Biological Sciences, Center for Human Health and the Environment, North Carolina State University, Raleigh, NC (United States)

2017-01-01

Zebrafish have become a key alternative model for studying health effects of environmental stressors, partly due to their genetic similarity to humans, fast generation time, and the efficiency of generating high-dimensional systematic data. Studies aiming to characterize adverse health effects in zebrafish typically include several phenotypic measurements (endpoints). While there is a solid biomedical basis for capturing a comprehensive set of endpoints, making summary judgments regarding health effects requires thoughtful integration across endpoints. Here, we introduce a Bayesian method to quantify the informativeness of 17 distinct zebrafish endpoints as a data-driven weighting scheme for a multi-endpoint summary measure, called weighted Aggregate Entropy (wAggE). We implement wAggE using high-throughput screening (HTS) data from zebrafish exposed to five concentrations of all 1060 ToxCast chemicals. Our results show that our empirical weighting scheme provides better performance in terms of the Receiver Operating Characteristic (ROC) curve for identifying significant morphological effects and improves robustness over traditional curve-fitting approaches. From a biological perspective, our results suggest that developmental cascade effects triggered by chemical exposure can be recapitulated by analyzing the relationships among endpoints. Thus, wAggE offers a powerful approach for analysis of multivariate phenotypes that can reveal underlying etiological processes. - Highlights: • Introduced a data-driven weighting scheme for multiple phenotypic endpoints. • Weighted Aggregate Entropy (wAggE) implies differential importance of endpoints. • Endpoint relationships reveal developmental cascade effects triggered by exposure. • wAggE is generalizable to multi-endpoint data of different shapes and scales.

Celiac Disease Histopathology Recapitulates Hedgehog Downregulation, Consistent with Wound Healing Processes Activation.

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Stefania Senger

Full Text Available In celiac disease (CD, intestinal epithelium damage occurs secondary to an immune insult and is characterized by blunting of the villi and crypt hyperplasia. Similarities between Hedgehog (Hh/BMP4 downregulation, as reported in a mouse model, and CD histopathology, suggest mechanistic involvement of Hh/BMP4/WNT pathways in proliferation and differentiation of immature epithelial cells in the context of human intestinal homeostasis and regeneration after damage. Herein we examined the nature of intestinal crypt hyperplasia and involvement of Hh/BMP4 in CD histopathology.Immunohistochemistry, qPCR and in situ hybridization were used to study a cohort of 24 healthy controls (HC and 24 patients with diagnosed acute celiac disease (A-CD intestinal biopsies. In A-CD we observed an increase in cells positive for Leucin-rich repeat-containing G protein-coupled receptor 5 (LGR5, an epithelial stem cell specific marker and expansion of WNT responding compartment. Further, we observed alteration in number and distribution of mesenchymal cells, predicted to be part of the intestinal stem cells niche. At the molecular level we found downregulation of indian hedgehog (IHH and other components of the Hh pathway, but we did not observe a concurrent downregulation of BMP4. However, we observed upregulation of BMPs antagonists, gremlin 1 and gremlin 2.Our data suggest that acute CD histopathology partially recapitulates the phenotype reported in Hh knockdown models. Specifically, Hh/BMP4 paradigm appears to be decoupled in CD, as the expansion of the immature cell population does not occur consequent to downregulation of BMP4. Instead, we provide evidence that upregulation of BMP antagonists play a key role in intestinal crypt hyperplasia. This study sheds light on the molecular mechanisms underlying CD histopathology and the limitations in the use of mouse models for celiac disease.

The developmental programme for genesis of the entire kidney is recapitulated in Wilms tumour

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Anaka, Matthew R.; Morison, Ian M.; Reeve, Anthony E.

2017-01-01

Wilms tumour (WT) is an embryonal tumour that recapitulates kidney development. The normal kidney is formed from two distinct embryological origins: the metanephric mesenchyme (MM) and the ureteric bud (UB). It is generally accepted that WT arises from precursor cells in the MM; however whether UB-equivalent structures participate in tumorigenesis is uncertain. To address the question of the involvement of UB, we assessed 55 Wilms tumours for the molecular features of MM and UB using gene expression profiling, immunohistochemsitry and immunofluorescence. Expression profiling primarily based on the Genitourinary Molecular Anatomy Project data identified molecular signatures of the UB and collecting duct as well as those of the proximal and distal tubules in the triphasic histology group. We performed immunolabeling for fetal kidneys and WTs. We focused on a central epithelial blastema pattern which is the characteristic of triphasic histology characterized by UB-like epithelial structures surrounded by MM and MM-derived epithelial structures, evoking the induction/aggregation phase of the developing kidney. The UB-like epithelial structures and surrounding MM and epithelial structures resembling early glomerular epithelium, proximal and distal tubules showed similar expression patterns to those of the developing kidney. These observations indicate WTs can arise from a precursor cell capable of generating the entire kidney, such as the cells of the intermediate mesoderm from which both the MM and UB are derived. Moreover, this provides an explanation for the variable histological features of mesenchymal to epithelial differentiation seen in WT. PMID:29040332

Primary fibroblasts from CSPα mutation carriers recapitulate hallmarks of the adult onset neuronal ceroid lipofuscinosis.

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Benitez, Bruno A; Sands, Mark S

2017-07-24

Mutations in the co- chaperone protein, CSPα, cause an autosomal dominant, adult-neuronal ceroid lipofuscinosis (AD-ANCL). The current understanding of CSPα function exclusively at the synapse fails to explain the autophagy-lysosome pathway (ALP) dysfunction in cells from AD-ANCL patients. Here, we demonstrate unexpectedly that primary dermal fibroblasts from pre-symptomatic mutation carriers recapitulate in vitro features found in the brains of AD-ANCL patients including auto-fluorescent storage material (AFSM) accumulation, CSPα aggregates, increased levels of lysosomal proteins and lysosome enzyme activities. AFSM accumulation correlates with CSPα aggregation and both are susceptible to pharmacological modulation of ALP function. In addition, we demonstrate that endogenous CSPα is present in the lysosome-enriched fractions and co-localizes with lysosome markers in soma, neurites and synaptic boutons. Overexpression of CSPα wild-type (WT) decreases lysotracker signal, secreted lysosomal enzymes and SNAP23-mediated lysosome exocytosis. CSPα WT, mutant and aggregated CSPα are degraded mainly by the ALP but this disease-causing mutation exhibits a faster rate of degradation. Co-expression of both WT and mutant CSPα cause a block in the fusion of autophagosomes/lysosomes. Our data suggest that aggregation-dependent perturbation of ALP function is a relevant pathogenic mechanism for AD-ANCL and supports the use of AFSM or CSPα aggregation as biomarkers for drug screening purposes.

Engineering strategies to recapitulate epithelial morphogenesis within synthetic three-dimensional extracellular matrix with tunable mechanical properties

International Nuclear Information System (INIS)

Miroshnikova, Y A; Sarang-Sieminski, A L; Jorgens, D M; Auer, M; Spirio, L; Weaver, V M

2011-01-01

The mechanical properties (e.g. stiffness) of the extracellular matrix (ECM) influence cell fate and tissue morphogenesis and contribute to disease progression. Nevertheless, our understanding of the mechanisms by which ECM rigidity modulates cell behavior and fate remains rudimentary. To address this issue, a number of two and three-dimensional (3D) hydrogel systems have been used to explore the effects of the mechanical properties of the ECM on cell behavior. Unfortunately, many of these systems have limited application because fiber architecture, adhesiveness and/or pore size often change in parallel when gel elasticity is varied. Here we describe the use of ECM-adsorbed, synthetic, self-assembling peptide (SAP) gels that are able to recapitulate normal epithelial acini morphogenesis and gene expression in a 3D context. By exploiting the range of viscoelasticity attainable with these SAP gels, and their ability to recreate native-like ECM fibril topology with minimal variability in ligand density and pore size, we were able to reconstitute normal and tumor-like phenotypes and gene expression patterns in nonmalignant mammary epithelial cells. Accordingly, this SAP hydrogel system presents the first tunable system capable of independently assessing the interplay between ECM stiffness and multi-cellular epithelial phenotype in a 3D context

Negative regulation of Ultrabithorax expression by engrailed is ...

Indian Academy of Sciences (India)

1Present address: European Molecular Biology Laboratory, Heidelberg, Germany. Abstract. In both ... Journal of Genetics, Vol. 79, No. ... Here we present results of a detailed study on the exact nature of ...... Academic Press, San Diego.

Comparison of Detailed and Simplified Models of Human Atrial Myocytes to Recapitulate Patient Specific Properties.

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Daniel M Lombardo

2016-08-01

Full Text Available Computer studies are often used to study mechanisms of cardiac arrhythmias, including atrial fibrillation (AF. A crucial component in these studies is the electrophysiological model that describes the membrane potential of myocytes. The models vary from detailed, describing numerous ion channels, to simplified, grouping ionic channels into a minimal set of variables. The parameters of these models, however, are determined across different experiments in varied species. Furthermore, a single set of parameters may not describe variations across patients, and models have rarely been shown to recapitulate critical features of AF in a given patient. In this study we develop physiologically accurate computational human atrial models by fitting parameters of a detailed and of a simplified model to clinical data for five patients undergoing ablation therapy. Parameters were simultaneously fitted to action potential (AP morphology, action potential duration (APD restitution and conduction velocity (CV restitution curves in these patients. For both models, our fitting procedure generated parameter sets that accurately reproduced clinical data, but differed markedly from published sets and between patients, emphasizing the need for patient-specific adjustment. Both models produced two-dimensional spiral wave dynamics for that were similar for each patient. These results show that simplified, computationally efficient models are an attractive choice for simulations of human atrial electrophysiology in spatially extended domains. This study motivates the development and validation of patient-specific model-based mechanistic studies to target therapy.

Clinical challenges of chronic wounds: searching for an optimal animal model to recapitulate their complexity

Directory of Open Access Journals (Sweden)

Robert Nunan

2014-11-01

Full Text Available The efficient healing of a skin wound is something that most of us take for granted but is essential for surviving day-to-day knocks and cuts, and is absolutely relied on clinically whenever a patient receives surgical intervention. However, the management of a chronic wound – defined as a barrier defect that has not healed in 3 months – has become a major therapeutic challenge throughout the Western world, and it is a problem that will only escalate with the increasing incidence of conditions that impede wound healing, such as diabetes, obesity and vascular disorders. Despite being clinically and molecularly heterogeneous, all chronic wounds are generally assigned to one of three major clinical categories: leg ulcers, diabetic foot ulcers or pressure ulcers. Although we have gleaned much knowledge about the fundamental cellular and molecular mechanisms that underpin healthy, acute wound healing from various animal models, we have learned much less about chronic wound repair pathology from these models. This might largely be because the animal models being used in this field of research have failed to recapitulate the clinical features of chronic wounds. In this Clinical Puzzle article, we discuss the clinical complexity of chronic wounds and describe the best currently available models for investigating chronic wound pathology. We also assess how such models could be optimised to become more useful tools for uncovering pathological mechanisms and potential therapeutic treatments.

Recapitulating the Structural Evolution of Redox Regulation in Adenosine 5'-Phosphosulfate Kinase from Cyanobacteria to Plants.

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Herrmann, Jonathan; Nathin, David; Lee, Soon Goo; Sun, Tony; Jez, Joseph M

2015-10-09

In plants, adenosine 5'-phosphosulfate (APS) kinase (APSK) is required for reproductive viability and the production of 3'-phosphoadenosine 5'-phosphosulfate (PAPS) as a sulfur donor in specialized metabolism. Previous studies of the APSK from Arabidopsis thaliana (AtAPSK) identified a regulatory disulfide bond formed between the N-terminal domain (NTD) and a cysteine on the core scaffold. This thiol switch is unique to mosses, gymnosperms, and angiosperms. To understand the structural evolution of redox control of APSK, we investigated the redox-insensitive APSK from the cyanobacterium Synechocystis sp. PCC 6803 (SynAPSK). Crystallographic analysis of SynAPSK in complex with either APS and a non-hydrolyzable ATP analog or APS and sulfate revealed the overall structure of the enzyme, which lacks the NTD found in homologs from mosses and plants. A series of engineered SynAPSK variants reconstructed the structural evolution of the plant APSK. Biochemical analyses of SynAPSK, SynAPSK H23C mutant, SynAPSK fused to the AtAPSK NTD, and the fusion protein with the H23C mutation showed that the addition of the NTD and cysteines recapitulated thiol-based regulation. These results reveal the molecular basis for structural changes leading to the evolution of redox control of APSK in the green lineage from cyanobacteria to plants. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

Recapitulating the Structural Evolution of Redox Regulation in Adenosine 5′-Phosphosulfate Kinase from Cyanobacteria to Plants*

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Herrmann, Jonathan; Nathin, David; Lee, Soon Goo; Sun, Tony; Jez, Joseph M.

2015-01-01

In plants, adenosine 5′-phosphosulfate (APS) kinase (APSK) is required for reproductive viability and the production of 3′-phosphoadenosine 5′-phosphosulfate (PAPS) as a sulfur donor in specialized metabolism. Previous studies of the APSK from Arabidopsis thaliana (AtAPSK) identified a regulatory disulfide bond formed between the N-terminal domain (NTD) and a cysteine on the core scaffold. This thiol switch is unique to mosses, gymnosperms, and angiosperms. To understand the structural evolution of redox control of APSK, we investigated the redox-insensitive APSK from the cyanobacterium Synechocystis sp. PCC 6803 (SynAPSK). Crystallographic analysis of SynAPSK in complex with either APS and a non-hydrolyzable ATP analog or APS and sulfate revealed the overall structure of the enzyme, which lacks the NTD found in homologs from mosses and plants. A series of engineered SynAPSK variants reconstructed the structural evolution of the plant APSK. Biochemical analyses of SynAPSK, SynAPSK H23C mutant, SynAPSK fused to the AtAPSK NTD, and the fusion protein with the H23C mutation showed that the addition of the NTD and cysteines recapitulated thiol-based regulation. These results reveal the molecular basis for structural changes leading to the evolution of redox control of APSK in the green lineage from cyanobacteria to plants. PMID:26294763

In vitro recapitulation of the urea cycle using murine embryonic stem cell-derived in vitro liver model.

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Tamai, Miho; Aoki, Mami; Nishimura, Akihito; Morishita, Koji; Tagawa, Yoh-ichi

2013-12-01

Ammonia, a toxic metabolite, is converted to urea in hepatocytes via the urea cycle, a process necessary for cell/organismal survival. In liver, hepatocytes, polygonal and multipolar structures, have a few sides which face hepatic sinusoids and adjacent hepatocytes to form intercellular bile canaliculi connecting to the ductules. The critical nature of this three-dimensional environment should be related to the maintenance of hepatocyte function such as urea synthesis. Recently, we established an in vitro liver model derived from murine embryonic stem cells, IVL(mES), which included the hepatocyte layer and a surrounding sinusoid vascular-like network. The IVL(mES) culture, where the hepatocyte is polarized in a similar fashion to its in vivo counterpart, could successfully recapitulate in vivo results. L-Ornithine is an intermediate of the urea cycle, but supplemental L-ornithine does not activate the urea cycle in the apolar primary hepatocyte of monolayer culture. In the IVL(mES), supplemental L-ornithine could activate the urea cycle, and also protect against ammonium/alcohol-induced hepatocyte death. While the IVL(mES) displays architectural and functional properties similar to the liver, primary hepatocyte of monolayer culture fail to model critical functional aspects of liver physiology. We propose that the IVL(mES) will represent a useful, humane alternative to animal studies for drug toxicity and mechanistic studies of liver injury.

Modelling the tumour microenvironment in long-term microencapsulated 3D co-cultures recapitulates phenotypic features of disease progression.

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Estrada, Marta F; Rebelo, Sofia P; Davies, Emma J; Pinto, Marta T; Pereira, Hugo; Santo, Vítor E; Smalley, Matthew J; Barry, Simon T; Gualda, Emilio J; Alves, Paula M; Anderson, Elizabeth; Brito, Catarina

2016-02-01

3D cell tumour models are generated mainly in non-scalable culture systems, using bioactive scaffolds. Many of these models fail to reflect the complex tumour microenvironment and do not allow long-term monitoring of tumour progression. To overcome these limitations, we have combined alginate microencapsulation with agitation-based culture systems, to recapitulate and monitor key aspects of the tumour microenvironment and disease progression. Aggregates of MCF-7 breast cancer cells were microencapsulated in alginate, either alone or in combination with human fibroblasts, then cultured for 15 days. In co-cultures, the fibroblasts arranged themselves around the tumour aggregates creating distinct epithelial and stromal compartments. The presence of fibroblasts resulted in secretion of pro-inflammatory cytokines and deposition of collagen in the stromal compartment. Tumour cells established cell-cell contacts and polarised around small lumina in the interior of the aggregates. Over the culture period, there was a reduction in oestrogen receptor and membranous E-cadherin alongside loss of cell polarity, increased collective cell migration and enhanced angiogenic potential in co-cultures. These phenotypic alterations, typical of advanced stages of cancer, were not observed in the mono-cultures of MCF-7 cells. The proposed model system constitutes a new tool to study tumour-stroma crosstalk, disease progression and drug resistance mechanisms. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

Mek1Y130C mice recapitulate aspects of human cardio-facio-cutaneous syndrome

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Aoidi, Rifdat; Houde, Nicolas; Landry-Truchon, Kim; Holter, Michael; Jacquet, Kevin; Charron, Louis; Yu, Benjamin D.; Rauen, Katherine A.; Bisson, Nicolas; Newbern, Jason

2018-01-01

ABSTRACT The RAS/MAPK signaling pathway is one of the most investigated pathways, owing to its established role in numerous cellular processes and implication in cancer. Germline mutations in genes encoding members of the RAS/MAPK pathway also cause severe developmental syndromes collectively known as RASopathies. These syndromes share overlapping characteristics, including craniofacial dysmorphology, cardiac malformations, cutaneous abnormalities and developmental delay. Cardio-facio-cutaneous syndrome (CFC) is a rare RASopathy associated with mutations in BRAF, KRAS, MEK1 (MAP2K1) and MEK2 (MAP2K2). MEK1 and MEK2 mutations are found in ∼25% of the CFC patients and the MEK1Y130C substitution is the most common one. However, little is known about the origins and mechanisms responsible for the development of CFC. To our knowledge, no mouse model carrying RASopathy-linked Mek1 or Mek2 gene mutations has been reported. To investigate the molecular and developmental consequences of the Mek1Y130C mutation, we generated a mouse line carrying this mutation. Analysis of mice from a Mek1 allelic series revealed that the Mek1Y130C allele expresses both wild-type and Y130C mutant forms of MEK1. However, despite reduced levels of MEK1 protein and the lower abundance of MEK1 Y130C protein than wild type, Mek1Y130C mutants showed increased ERK (MAPK) protein activation in response to growth factors, supporting a role for MEK1 Y130C in hyperactivation of the RAS/MAPK pathway, leading to CFC. Mek1Y130C mutant mice exhibited pulmonary artery stenosis, cranial dysmorphia and neurological anomalies, including increased numbers of GFAP+ astrocytes and Olig2+ oligodendrocytes in regions of the cerebral cortex. These data indicate that the Mek1Y130C mutation recapitulates major aspects of CFC, providing a new animal model to investigate the physiopathology of this RASopathy. This article has an associated First Person interview with the first author of the paper. PMID:29590634

HSC extrinsic sex-related and intrinsic autoimmune disease-related human B-cell variation is recapitulated in humanized mice.

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Borsotti, Chiara; Danzl, Nichole M; Nauman, Grace; Hölzl, Markus A; French, Clare; Chavez, Estefania; Khosravi-Maharlooei, Mohsen; Glauzy, Salome; Delmotte, Fabien R; Meffre, Eric; Savage, David G; Campbell, Sean R; Goland, Robin; Greenberg, Ellen; Bi, Jing; Satwani, Prakash; Yang, Suxiao; Bathon, Joan; Winchester, Robert; Sykes, Megan

2017-10-24

B cells play a major role in antigen presentation and antibody production in the development of autoimmune diseases, and some of these diseases disproportionally occur in females. Moreover, immune responses tend to be stronger in female vs male humans and mice. Because it is challenging to distinguish intrinsic from extrinsic influences on human immune responses, we used a personalized immune (PI) humanized mouse model, in which immune systems were generated de novo from adult human hematopoietic stem cells (HSCs) in immunodeficient mice. We assessed the effect of recipient sex and of donor autoimmune diseases (type 1 diabetes [T1D] and rheumatoid arthritis [RA]) on human B-cell development in PI mice. We observed that human B-cell levels were increased in female recipients regardless of the source of human HSCs or the strain of immunodeficient recipient mice. Moreover, mice injected with T1D- or RA-derived HSCs displayed B-cell abnormalities compared with healthy control HSC-derived mice, including altered B-cell levels, increased proportions of mature B cells and reduced CD19 expression. Our study revealed an HSC-extrinsic effect of recipient sex on human B-cell reconstitution. Moreover, the PI humanized mouse model revealed HSC-intrinsic defects in central B-cell tolerance that recapitulated those in patients with autoimmune diseases. These results demonstrate the utility of humanized mouse models as a tool to better understand human immune cell development and regulation.

Host-Specific Parvovirus Evolution in Nature Is Recapitulated by In Vitro Adaptation to Different Carnivore Species

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Allison, Andrew B.; Kohler, Dennis J.; Ortega, Alicia; Hoover, Elizabeth A.; Grove, Daniel M.; Holmes, Edward C.; Parrish, Colin R.

2014-01-01

Canine parvovirus (CPV) emerged as a new pandemic pathogen of dogs in the 1970s and is closely related to feline panleukopenia virus (FPV), a parvovirus of cats and related carnivores. Although both viruses have wide host ranges, analysis of viral sequences recovered from different wild carnivore species, as shown here, demonstrated that >95% were derived from CPV-like viruses, suggesting that CPV is dominant in sylvatic cycles. Many viral sequences showed host-specific mutations in their capsid proteins, which were often close to sites known to control binding to the transferrin receptor (TfR), the host receptor for these carnivore parvoviruses, and which exhibited frequent parallel evolution. To further examine the process of host adaptation, we passaged parvoviruses with alternative backgrounds in cells from different carnivore hosts. Specific mutations were selected in several viruses and these differed depending on both the background of the virus and the host cells in which they were passaged. Strikingly, these in vitro mutations recapitulated many specific changes seen in viruses from natural populations, strongly suggesting they are host adaptive, and which were shown to result in fitness advantages over their parental virus. Comparison of the sequences of the transferrin receptors of the different carnivore species demonstrated that many mutations occurred in and around the apical domain where the virus binds, indicating that viral variants were likely selected through their fit to receptor structures. Some of the viruses accumulated high levels of variation upon passage in alternative hosts, while others could infect multiple different hosts with no or only a few additional mutations. Overall, these studies demonstrate that the evolutionary history of a virus, including how long it has been circulating and in which hosts, as well as its phylogenetic background, has a profound effect on determining viral host range. PMID:25375184

Host-specific parvovirus evolution in nature is recapitulated by in vitro adaptation to different carnivore species.

Directory of Open Access Journals (Sweden)

Andrew B Allison

2014-11-01

Full Text Available Canine parvovirus (CPV emerged as a new pandemic pathogen of dogs in the 1970s and is closely related to feline panleukopenia virus (FPV, a parvovirus of cats and related carnivores. Although both viruses have wide host ranges, analysis of viral sequences recovered from different wild carnivore species, as shown here, demonstrated that>95% were derived from CPV-like viruses, suggesting that CPV is dominant in sylvatic cycles. Many viral sequences showed host-specific mutations in their capsid proteins, which were often close to sites known to control binding to the transferrin receptor (TfR, the host receptor for these carnivore parvoviruses, and which exhibited frequent parallel evolution. To further examine the process of host adaptation, we passaged parvoviruses with alternative backgrounds in cells from different carnivore hosts. Specific mutations were selected in several viruses and these differed depending on both the background of the virus and the host cells in which they were passaged. Strikingly, these in vitro mutations recapitulated many specific changes seen in viruses from natural populations, strongly suggesting they are host adaptive, and which were shown to result in fitness advantages over their parental virus. Comparison of the sequences of the transferrin receptors of the different carnivore species demonstrated that many mutations occurred in and around the apical domain where the virus binds, indicating that viral variants were likely selected through their fit to receptor structures. Some of the viruses accumulated high levels of variation upon passage in alternative hosts, while others could infect multiple different hosts with no or only a few additional mutations. Overall, these studies demonstrate that the evolutionary history of a virus, including how long it has been circulating and in which hosts, as well as its phylogenetic background, has a profound effect on determining viral host range.

Control of oxygen tension recapitulates zone-specific functions in human liver microphysiology systems.

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Lee-Montiel, Felipe T; George, Subin M; Gough, Albert H; Sharma, Anup D; Wu, Juanfang; DeBiasio, Richard; Vernetti, Lawrence A; Taylor, D Lansing

2017-10-01

developed and present a method for computationally modeling and measuring oxygen that can easily be implemented in all MPS models. We have applied this method in a liver MPS in which we are then able to control oxygenation in separate devices and demonstrate that zonation-dependent hepatocyte functions in the MPS recapitulate what is known about in vivo liver physiology. We believe that this advance allows a deep experimental investigation on the role of zonation in liver metabolism and disease. In addition, modeling and measuring oxygen tension will be required as investigators migrate from PDMS to plastic and glass devices.

The Progressive BSSG Rat Model of Parkinson's: Recapitulating Multiple Key Features of the Human Disease.

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Jackalina M Van Kampen

Full Text Available The development of effective neuroprotective therapies for Parkinson's disease (PD has been severely hindered by the notable lack of an appropriate animal model for preclinical screening. Indeed, most models currently available are either acute in nature or fail to recapitulate all characteristic features of the disease. Here, we present a novel progressive model of PD, with behavioural and cellular features that closely approximate those observed in patients. Chronic exposure to dietary phytosterol glucosides has been found to be neurotoxic. When fed to rats, β-sitosterol β-d-glucoside (BSSG triggers the progressive development of parkinsonism, with clinical signs and histopathology beginning to appear following cessation of exposure to the neurotoxic insult and continuing to develop over several months. Here, we characterize the progressive nature of this model, its non-motor features, the anatomical spread of synucleinopathy, and response to levodopa administration. In Sprague Dawley rats, chronic BSSG feeding for 4 months triggered the progressive development of a parkinsonian phenotype and pathological events that evolved slowly over time, with neuronal loss beginning only after toxin exposure was terminated. At approximately 3 months following initiation of BSSG exposure, animals displayed the early emergence of an olfactory deficit, in the absence of significant dopaminergic nigral cell loss or locomotor deficits. Locomotor deficits developed gradually over time, initially appearing as locomotor asymmetry and developing into akinesia/bradykinesia, which was reversed by levodopa treatment. Late-stage cognitive impairment was observed in the form of spatial working memory deficits, as assessed by the radial arm maze. In addition to the progressive loss of TH+ cells in the substantia nigra, the appearance of proteinase K-resistant intracellular α-synuclein aggregates was also observed to develop progressively, appearing first in the

Ferrets Infected with Bundibugyo Virus or Ebola Virus Recapitulate Important Aspects of Human Filovirus Disease.

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Kozak, Robert; He, Shihua; Kroeker, Andrea; de La Vega, Marc-Antoine; Audet, Jonathan; Wong, Gary; Urfano, Chantel; Antonation, Kym; Embury-Hyatt, Carissa; Kobinger, Gary P; Qiu, Xiangguo

2016-10-15

Bundibugyo virus (BDBV) is the etiological agent of a severe hemorrhagic fever in humans with a case-fatality rate ranging from 25 to 36%. Despite having been known to the scientific and medical communities for almost 1 decade, there is a dearth of studies on this pathogen due to the lack of a small animal model. Domestic ferrets are commonly used to study other RNA viruses, including members of the order Mononegavirales To investigate whether ferrets were susceptible to filovirus infections, ferrets were challenged with a clinical isolate of BDBV. Animals became viremic within 4 days and succumbed to infection between 8 and 9 days, and a petechial rash was observed with moribund ferrets. Furthermore, several hallmarks of human filoviral disease were recapitulated in the ferret model, including substantial decreases in lymphocyte and platelet counts and dysregulation of key biochemical markers related to hepatic/renal function, as well as coagulation abnormalities. Virological, histopathological, and immunohistochemical analyses confirmed uncontrolled BDBV replication in the major organs. Ferrets were also infected with Ebola virus (EBOV) to confirm their susceptibility to another filovirus species and to potentially establish a virus transmission model. Similar to what was seen with BDBV, important hallmarks of human filoviral disease were observed in EBOV-infected ferrets. This study demonstrates the potential of this small animal model for studying BDBV and EBOV using wild-type isolates and will accelerate efforts to understand filovirus pathogenesis and transmission as well as the development of specific vaccines and antivirals. The 2013-2016 outbreak of Ebola virus in West Africa has highlighted the threat posed by filoviruses to global public health. Bundibugyo virus (BDBV) is a member of the genus Ebolavirus and has caused outbreaks in the past but is relatively understudied, likely due to the lack of a suitable small animal model. Such a model for BDBV is

EMT/MET at the Crossroad of Stemness, Regeneration and Oncogenesis: The Ying-Yang Equilibrium Recapitulated in Cell Spheroids

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Elvira Forte

2017-07-01

Full Text Available The epithelial-to-mesenchymal transition (EMT is an essential trans-differentiation process, which plays a critical role in embryonic development, wound healing, tissue regeneration, organ fibrosis, and cancer progression. It is the fundamental mechanism by which epithelial cells lose many of their characteristics while acquiring features typical of mesenchymal cells, such as migratory capacity and invasiveness. Depending on the contest, EMT is complemented and balanced by the reverse process, the mesenchymal-to-epithelial transition (MET. In the saving economy of the living organisms, the same (Ying-Yang tool is integrated as a physiological strategy in embryonic development, as well as in the course of reparative or disease processes, prominently fibrosis, tumor invasion and metastasis. These mechanisms and their related signaling (e.g., TGF-β and BMPs have been effectively studied in vitro by tissue-derived cell spheroids models. These three-dimensional (3D cell culture systems, whose phenotype has been shown to be strongly dependent on TGF-β-regulated EMT/MET processes, present the advantage of recapitulating in vitro the hypoxic in vivo micro-environment of tissue stem cell niches and their formation. These spheroids, therefore, nicely reproduce the finely regulated Ying-Yang equilibrium, which, together with other mechanisms, can be determinant in cell fate decisions in many pathophysiological scenarios, such as differentiation, fibrosis, regeneration, and oncogenesis. In this review, current progress in the knowledge of signaling pathways affecting EMT/MET and stemness regulation will be outlined by comparing data obtained from cellular spheroids systems, as ex vivo niches of stem cells derived from normal and tumoral tissues. The mechanistic correspondence in vivo and the possible pharmacological perspective will be also explored, focusing especially on the TGF-β-related networks, as well as others, such as SNAI1, PTEN, and EGR1. This

A mammalian conserved element derived from SINE displays enhancer properties recapitulating Satb2 expression in early-born callosal projection neurons.

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Kensuke Tashiro

Full Text Available Short interspersed repetitive elements (SINEs are highly repeated sequences that account for a significant proportion of many eukaryotic genomes and are usually considered "junk DNA". However, we previously discovered that many AmnSINE1 loci are evolutionarily conserved across mammalian genomes, suggesting that they may have acquired significant functions involved in controlling mammalian-specific traits. Notably, we identified the AS021 SINE locus, located 390 kbp upstream of Satb2. Using transgenic mice, we showed that this SINE displays specific enhancer activity in the developing cerebral cortex. The transcription factor Satb2 is expressed by cortical neurons extending axons through the corpus callosum and is a determinant of callosal versus subcortical projection. Mouse mutants reveal a crucial function for Sabt2 in corpus callosum formation. In this study, we compared the enhancer activity of the AS021 locus with Satb2 expression during telencephalic development in the mouse. First, we showed that the AS021 enhancer is specifically activated in early-born Satb2(+ neurons. Second, we demonstrated that the activity of the AS021 enhancer recapitulates the expression of Satb2 at later embryonic and postnatal stages in deep-layer but not superficial-layer neurons, suggesting the possibility that the expression of Satb2 in these two subpopulations of cortical neurons is under genetically distinct transcriptional control. Third, we showed that the AS021 enhancer is activated in neurons projecting through the corpus callosum, as described for Satb2(+ neurons. Notably, AS021 drives specific expression in axons crossing through the ventral (TAG1(-/NPY(+ portion of the corpus callosum, confirming that it is active in a subpopulation of callosal neurons. These data suggest that exaptation of the AS021 SINE locus might be involved in enhancement of Satb2 expression, leading to the establishment of interhemispheric communication via the corpus callosum

The Aorta-Gonad-Mesonephros Organ Culture Recapitulates 5hmC Reorganization and Replication-Dependent and Independent Loss of DNA Methylation in the Germline.

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Calvopina, Joseph Hargan; Cook, Helene; Vincent, John J; Nee, Kevin; Clark, Amander T

2015-07-01

Removal of cytosine methylation from the genome is critical for reprogramming and transdifferentiation and plays a central role in our understanding of the fundamental principles of embryo lineage development. One of the major models for studying cytosine demethylation is the mammalian germ line during the primordial germ cell (PGC) stage of embryo development. It is now understood that oxidation of 5-methylcytosine (5mC) to 5-hydroxymethylcytosine (5hmC) is required to remove cytosine methylation in a locus-specific manner in PGCs; however, the mechanisms downstream of 5hmC are controversial and hypothesized to involve either active demethylation or replication-coupled loss. In the current study, we used the aorta-gonad-mesonephros (AGM) organ culture model to show that this model recapitulates germ line reprogramming, including 5hmC reorganization and loss of cytosine methylation from Snrpn and H19 imprinting control centers (ICCs). To directly address the hypothesis that cell proliferation is required for cytosine demethylation, we blocked PI3-kinase-dependent PGC proliferation and show that this leads to a G1 and G2/M cell cycle arrest in PGCs, together with retained levels of cytosine methylation at the Snrpn ICC, but not at the H19 ICC. Taken together, the AGM organ culture model is an important tool to evaluate mechanisms of locus-specific demethylation and the role of PI3-kinase-dependent PGC proliferation in the locus-specific removal of cytosine methylation from the genome.

Toward Personalized Medicine: Using Cardiomyocytes Differentiated From Urine-Derived Pluripotent Stem Cells to Recapitulate Electrophysiological Characteristics of Type 2 Long QT Syndrome.

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Jouni, Mariam; Si-Tayeb, Karim; Es-Salah-Lamoureux, Zeineb; Latypova, Xenia; Champon, Benoite; Caillaud, Amandine; Rungoat, Anais; Charpentier, Flavien; Loussouarn, Gildas; Baró, Isabelle; Zibara, Kazem; Lemarchand, Patricia; Gaborit, Nathalie

2015-09-01

Human genetically inherited cardiac diseases have been studied mainly in heterologous systems or animal models, independent of patients' genetic backgrounds. Because sources of human cardiomyocytes (CMs) are extremely limited, the use of urine samples to generate induced pluripotent stem cell-derived CMs would be a noninvasive method to identify cardiac dysfunctions that lead to pathologies within patients' specific genetic backgrounds. The objective was to validate the use of CMs differentiated from urine-derived human induced pluripotent stem (UhiPS) cells as a new cellular model for studying patients' specific arrhythmia mechanisms. Cells obtained from urine samples of a patient with long QT syndrome who harbored the HERG A561P gene mutation and his asymptomatic noncarrier mother were reprogrammed using the episomal-based method. UhiPS cells were then differentiated into CMs using the matrix sandwich method.UhiPS-CMs showed proper expression of atrial and ventricular myofilament proteins and ion channels. They were electrically functional, with nodal-, atrial- and ventricular-like action potentials recorded using high-throughput optical and patch-clamp techniques. Comparison of HERG expression from the patient's UhiPS-CMs to the mother's UhiPS-CMs showed that the mutation led to a trafficking defect that resulted in reduced delayed rectifier K(+) current (IKr). This phenotype gave rise to action potential prolongation and arrhythmias. UhiPS cells from patients carrying ion channel mutations can be used as novel tools to differentiate functional CMs that recapitulate cardiac arrhythmia phenotypes. © 2015 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.

Extensive Tonotopic Mapping across Auditory Cortex Is Recapitulated by Spectrally Directed Attention and Systematically Related to Cortical Myeloarchitecture.

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Dick, Frederic K; Lehet, Matt I; Callaghan, Martina F; Keller, Tim A; Sereno, Martin I; Holt, Lori L

2017-12-13

diverse pathologies reduce quality of life by impacting such spectrally directed auditory attention, its neurobiological bases are unclear. We demonstrate that human primary and nonprimary auditory cortical activation is modulated by spectrally directed attention in a manner that recapitulates its tonotopic sensory organization. Further, the graded activation profiles evoked by single-frequency bands are correlated with attentionally driven activation when these bands are presented in complex soundscapes. Finally, we observe a strong concordance in the degree of cortical myelination and the strength of tonotopic activation across several auditory cortical regions. Copyright © 2017 Dick et al.

Mice long-term high-fat diet feeding recapitulates human cardiovascular alterations: an animal model to study the early phases of diabetic cardiomyopathy.

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Sebastián D Calligaris

Full Text Available BACKGROUND/AIM: Hypercaloric diet ingestion and sedentary lifestyle result in obesity. Metabolic syndrome is a cluster of clinical features secondary to obesity, considered as a pre-diabetic condition and recognized as an independent risk factor for cardiovascular diseases. To better understand the relationship between obesity, metabolic syndrome and cardiovascular disease as well as for the development of novel therapeutic strategies, animal models that reproduce the etiology, course and outcomes of these pathologies are required. The aim of this work was to characterize the long-term effects of high-fat diet-induced obesity on the mice cardiovascular system, in order to make available a new animal model for diabetic cardiomyopathy. METHODS/RESULTS: Male C57BL/6 mice were fed with a standardized high-fat diet (obese or regular diet (normal for 16 months. Metabolic syndrome was evaluated testing plasma glucose, triglycerides, cholesterol, insulin, and glucose tolerance. Arterial pressure was measured using a sphygmomanometer (non invasive method and by hemodynamic parameters (invasive method. Cardiac anatomy was described based on echocardiography and histological studies. Cardiac function was assessed by cardiac catheterization under a stress test. Cardiac remodelling and metabolic biomarkers were assessed by RT-qPCR and immunoblotting. As of month eight, the obese mice were overweight, hyperglycaemic, insulin resistant, hyperinsulinemic and hypercholesterolemic. At month 16, they also presented normal arterial pressure but altered vascular reactivity (vasoconstriction, and cardiac contractility reserve reduction, heart mass increase, cardiomyocyte hypertrophy, cardiac fibrosis, and heart metabolic compensations. By contrast, the normal mice remained healthy throughout the study. CONCLUSIONS: Mice fed with a high-fat diet for prolonged time recapitulates the etiology, course and outcomes of the early phases of human diabetic cardiomyopathy.

Ultrastructural investigation and in vitro recapitulation of spermatid differentiation in a potential bio-indicator species - The marine invertebrate Galeolaria gemineoa (Polychaeta: Serpulidae.

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Yonggang Lu

Full Text Available Galeolaria gemineoa is a sessile broadcast-spawning marine invertebrate, whose spermatozoa have been regarded as a sensitive indicator for water quality monitoring. In this study, 10 steps of spermiogenesis have been identified at the ultrastructural level and this differentiation process has been recapitulated in vitro up to the point of spermiogenesis (step 7-9 spermatids. On completion of the second meiosis, newly formed spermatids were detached from the seminiferous epithelium and released to the lumen of each germinal chamber. These spermatids were present in pairs and interconnected by a cytoplasmic bridge throughout the entire spermiogenic process. On the basis of morphological events such as formation of the acrosome, elongation of the flagellum, and condensation of the nucleus, spermiogenesis has been temporally divided into Golgi phase, acrosomal phase and maturation phase. During the Golgi phase, proacrosomal vesicles appeared at the posterior pole of the spermatids and gradually fused into a proacrosomal vacuole. Simultaneously, the distal centriole docked onto the plasma membrane and gave rise to a formative flagellum. The acrosomal phase was characterised by differentiation of the acrosome, condensation of the chromatin and formation of a mitochondrial sheath surrounding the initial portion of the flagellum. During the maturation phase, the fully differentiated acrosome migrated to the anterior pole and excess cytoplasm was extruded from the spermatids in the form of residual bodies. In addition, we successfully induced step 1-3 spermatids to differentiate into the step 7-9 spermatids in both male germinal fluid and 10% foetal bovine serum in RPMI 1640 medium, but failed to replicate this process in female or boiled male germinal fluids. This finding supports our concept that spermatid differentiation in this species is dependent on intrinsic developmental programming and does not require input from accompanying nurse cells.

Subthreshold Desensitization of Human Basophils Re-capitulates the Loss of syk and FcεRI expression Characterized by Other Methods of Desensitization

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MacGlashan, Donald

2012-01-01

Background Clinical desensitization of patients to drugs involves progressive exposure to escalating doses of drug over a period of 24 hours. In prior studies, this method was recapitulated in vitro to also demonstrate loss of mast cell or basophil responsiveness. However, most signaling studies of human basophils have identified changes in signaling by using other methods of inducing cellular desensitization. Objective This study examined two well-described endpoints of basophil desensitization, loss of syk or FcεRI expression, under conditions of subthreshold desensitization. Methods The loss of FceRI and syk was examined in human basophils. Results It was shown that both loss of syk and FcεRI/IgE occurred during an escalating series of stimulation (anti-IgE Ab) and that expression loss occurred despite the presence of little histamine release. If basophils were first cultured for 3 days in 10 ng/ml IL-3, the concentration-dependence of histamine release shifted to 100 fold lower concentrations of stimulus. However, loss of syk did not show any change in its EC50 while loss of FcεRI also shifted 100 fold. From the perspective of early signal element activation, the marked shift in the EC50 for histamine release was not accompanied by similar shifts in the EC50s for several signaling elements. The EC50s for phospho-Src, phospho-SHIP1, phospho-Syk, or phospho-Cbl did not change while the EC50s for phospho-Erk and the cytosolic calcium response did shift 100 fold. Conclusions These studies show that under normal conditions, subthreshold desensitization leads to loss of two critical signaling molecules (FcεRI and syk) but under at least one condition, treatment with IL-3, it is possible to markedly blunt the loss of syk, but not FcεRI, while executing a proper subthreshold titration. These data also suggest that IL-3 modifies only the sensitivity of signaling elements that are downstream of syk activation. PMID:22702505

Computational cell model based on autonomous cell movement regulated by cell-cell signalling successfully recapitulates the "inside and outside" pattern of cell sorting

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Ajioka Itsuki

2007-09-01

Full Text Available Abstract Background Development of multicellular organisms proceeds from a single fertilized egg as the combined effect of countless numbers of cellular interactions among highly dynamic cells. Since at least a reminiscent pattern of morphogenesis can be recapitulated in a reproducible manner in reaggregation cultures of dissociated embryonic cells, which is known as cell sorting, the cells themselves must possess some autonomous cell behaviors that assure specific and reproducible self-organization. Understanding of this self-organized dynamics of heterogeneous cell population seems to require some novel approaches so that the approaches bridge a gap between molecular events and morphogenesis in developmental and cell biology. A conceptual cell model in a computer may answer that purpose. We constructed a dynamical cell model based on autonomous cell behaviors, including cell shape, growth, division, adhesion, transformation, and motility as well as cell-cell signaling. The model gives some insights about what cellular behaviors make an appropriate global pattern of the cell population. Results We applied the model to "inside and outside" pattern of cell-sorting, in which two different embryonic cell types within a randomly mixed aggregate are sorted so that one cell type tends to gather in the central region of the aggregate and the other cell type surrounds the first cell type. Our model can modify the above cell behaviors by varying parameters related to them. We explored various parameter sets with which the "inside and outside" pattern could be achieved. The simulation results suggested that direction of cell movement responding to its neighborhood and the cell's mobility are important for this specific rearrangement. Conclusion We constructed an in silico cell model that mimics autonomous cell behaviors and applied it to cell sorting, which is a simple and appropriate phenomenon exhibiting self-organization of cell population. The model

Aims and methods of education: A recapitulation

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Pantić Nataša

2007-01-01

Full Text Available This paper gives an overview of principal distinction between the aims of the so-called "traditional" and "progressive" education and respective pedagogies associated with each. The term "traditional" education is used to denote the kind of education that prepares people for their role in society as it is, while the term "progressive" is used for education that aspires to equip mankind with capacity to shape the change of society. The paper raises some critical questions about the role of pedagogy in achieving the aims of the progressive model, arguing that the employment of "progressive" methods does not necessarily guarantee the achievement of the commonly professed purposes of progressive education. This is illustrated in the paper by the results of a study in English schools showing how despite the claim of progressive methods, teachers tend to retain traditional attitudes and on the other hand, how even traditional teaching methods can serve the progressive purpose. This is not to advocate for the traditional pedagogy, but to suggest that it might be something other than pedagogy that makes a critical difference in educating liberal-minded citizens of the future. In this sense the paper explores the role of other factors that make a difference towards progressive education, such as democratization of human relations in school ethos and respect for children's freedom.

Ubx regulates differential enlargement and diversification of insect hind legs.

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Najmus Mahfooz

2007-09-01

Full Text Available Differential enlargement of hind (T3 legs represents one of the hallmarks of insect evolution. However, the actual mechanism(s responsible are yet to be determined. To address this issue, we have now studied the molecular basis of T3 leg enlargement in Oncopeltus fasciatus (milkweed bug and Acheta domesticus (house cricket. In Oncopeltus, the T3 tibia displays a moderate increase in size, whereas in Acheta, the T3 femur, tibia, and tarsus are all greatly enlarged. Here, we show that the hox gene Ultrabithorax (Ubx is expressed in the enlarged segments of hind legs. Furthermore, we demonstrate that depletion of Ubx during embryogenesis has a primary effect in T3 legs and causes shortening of leg segments that are enlarged in a wild type. This result shows that Ubx is regulating the differential growth and enlargement of T3 legs in both Oncopeltus and Acheta. The emerging view suggests that Ubx was co-opted for a novel role in regulating leg growth and that the transcriptional modification of its expression may be a universal mechanism for the evolutionary diversification of insect hind legs.

Drosophila atonal fully rescues the phenotype of Math1 null mice: new functions evolve in new cellular contexts

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Wang, Vincent Y.; Hassan, Bassem A.; Bellen, Hugo J.; Zoghbi, Huda Y.

2002-01-01

Many genes share sequence similarity between species, but their properties often change significantly during evolution. For example, the Drosophila genes engrailed and orthodenticle and the onychophoran gene Ultrabithorax only partially substitute for their mouse or Drosophila homologs. We have been analyzing the relationship between atonal (ato) in the fruit fly and its mouse homolog, Math1. In flies, ato acts as a proneural gene that governs the development of chordotonal organs (CHOs), which serve as stretch receptors in the body wall and joints and as auditory organs in the antennae. In the fly CNS, ato is important not for specification but for axonal arborization. Math1, in contrast, is required for the specification of cells in both the CNS and the PNS. Furthermore, Math1 serves a role in the development of secretory lineage cells in the gut, a function that does not parallel any known to be served by ato. We wondered whether ato and Math1 might be more functionally homologous than they appear, so we expressed Math1 in ato mutant flies and ato in Math1 null mice. To our surprise, the two proteins are functionally interchangeable.

Can injured adult CNS axons regenerate by recapitulating development?

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Hilton, Brett J; Bradke, Frank

2017-10-01

In the adult mammalian central nervous system (CNS), neurons typically fail to regenerate their axons after injury. During development, by contrast, neurons extend axons effectively. A variety of intracellular mechanisms mediate this difference, including changes in gene expression, the ability to form a growth cone, differences in mitochondrial function/axonal transport and the efficacy of synaptic transmission. In turn, these intracellular processes are linked to extracellular differences between the developing and adult CNS. During development, the extracellular environment directs axon growth and circuit formation. In adulthood, by contrast, extracellular factors, such as myelin and the extracellular matrix, restrict axon growth. Here, we discuss whether the reactivation of developmental processes can elicit axon regeneration in the injured CNS. © 2017. Published by The Company of Biologists Ltd.

Engineering Hydrogel Microenvironments to Recapitulate the Stem Cell Niche.

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Madl, Christopher M; Heilshorn, Sarah C

2018-06-04

Stem cells are a powerful resource for many applications including regenerative medicine, patient-specific disease modeling, and toxicology screening. However, eliciting the desired behavior from stem cells, such as expansion in a naïve state or differentiation into a particular mature lineage, remains challenging. Drawing inspiration from the native stem cell niche, hydrogel platforms have been developed to regulate stem cell fate by controlling microenvironmental parameters including matrix mechanics, degradability, cell-adhesive ligand presentation, local microstructure, and cell-cell interactions. We survey techniques for modulating hydrogel properties and review the effects of microenvironmental parameters on maintaining stemness and controlling differentiation for a variety of stem cell types. Looking forward, we envision future hydrogel designs spanning a spectrum of complexity, ranging from simple, fully defined materials for industrial expansion of stem cells to complex, biomimetic systems for organotypic cell culture models.

Mouse Models Recapitulating Human Adrenocortical Tumors: What is lacking?

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Felicia Leccia

2016-07-01

Full Text Available Adrenal cortex tumors are divided into benign forms such as primary hyperplasias and adrenocortical adenomas (ACAs, and malignant forms or adrenocortical carcinomas (ACCs. Primary hyperplasias are rare causes of ACTH-independent hypercortisolism. ACAs are the most common type of adrenal gland tumors and they are rarely functional, i.e producing steroids. When functional, adenomas result in endocrine disorders such as Cushing’s syndrome (hypercortisolism or Conn’s syndrome (hyperaldosteronism. In contrast, ACCs are extremely rare but highly aggressive tumors that may also lead to hypersecreting syndromes. Genetic analyses of patients with sporadic or familial forms of adrenocortical tumors led to the identification of potentially causative genes, most of them being involved in PKA, Wnt/β-catenin and P53 signaling pathways. Development of mouse models is a crucial step to firmly establish the functional significance of candidate genes, to dissect mechanisms leading to tumors and endocrine disorders and in fine to provide in vivo tools for therapeutic screens. In this article we will provide an overview on the existing mouse models (xenografted and genetically engineered of adrenocortical tumors by focusing on the role of PKA and Wnt/β-catenin pathways in this context. We will discuss the advantages and limitations of models that have been developed heretofore and we will point out necessary improvements in the development of next generation mouse models of adrenal diseases.

A Syrian golden hamster model recapitulating ebola hemorrhagic fever.

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Ebihara, Hideki; Zivcec, Marko; Gardner, Donald; Falzarano, Darryl; LaCasse, Rachel; Rosenke, Rebecca; Long, Dan; Haddock, Elaine; Fischer, Elizabeth; Kawaoka, Yoshihiro; Feldmann, Heinz

2013-01-15

Ebola hemorrhagic fever (EHF) is a severe viral infection for which no effective treatment or vaccine is currently available. While the nonhuman primate (NHP) model is used for final evaluation of experimental vaccines and therapeutic efficacy, rodent models have been widely used in ebolavirus research because of their convenience. However, the validity of rodent models has been questioned given their low predictive value for efficacy testing of vaccines and therapeutics, a result of the inconsistent manifestation of coagulopathy seen in EHF. Here, we describe a lethal Syrian hamster model of EHF using mouse-adapted Ebola virus. Infected hamsters displayed most clinical hallmarks of EHF, including severe coagulopathy and uncontrolled host immune responses. Thus, the hamster seems to be superior to the existing rodent models, offering a better tool for understanding the critical processes in pathogenesis and providing a new model for evaluating prophylactic and postexposure interventions prior to testing in NHPs.

Humanized mouse models: Application to human diseases.

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Ito, Ryoji; Takahashi, Takeshi; Ito, Mamoru

2018-05-01

Humanized mice are superior to rodents for preclinical evaluation of the efficacy and safety of drug candidates using human cells or tissues. During the past decade, humanized mouse technology has been greatly advanced by the establishment of novel platforms of genetically modified immunodeficient mice. Several human diseases can be recapitulated using humanized mice due to the improved engraftment and differentiation capacity of human cells or tissues. In this review, we discuss current advanced humanized mouse models that recapitulate human diseases including cancer, allergy, and graft-versus-host disease. © 2017 Wiley Periodicals, Inc.

Org-1-dependent lineage reprogramming generates the ventral longitudinal musculature of the Drosophila heart.

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Schaub, Christoph; März, Johannes; Reim, Ingolf; Frasch, Manfred

2015-02-16

Only few examples of transdifferentiation, which denotes the conversion of one differentiated cell type to another, are known to occur during normal development, and more often, it is associated with regeneration processes. With respect to muscles, dedifferentiation/redifferentiation processes have been documented during post-traumatic muscle regeneration in blastema of newts as well as during myocardial regeneration. As shown herein, the ventral longitudinal muscles of the adult Drosophila heart arise from specific larval alary muscles in a process that represents the first known example of syncytial muscle transdifferentiation via dedifferentiation into mononucleate myoblasts during normal development. We demonstrate that this unique process depends on the reinitiation of a transcriptional program previously employed for embryonic alary muscle development, in which the factors Org-1 (Drosophila Tbx1) and Tailup (Drosophila Islet1) are key components. During metamorphosis, the action of these factors is combined with cell-autonomous inputs from the ecdysone steroid and the Hox gene Ultrabithorax, which provide temporal and spatial specificity to the transdifferentiation events. Following muscle dedifferentiation, inductive cues, particularly from the remodeling heart tube, are required for the redifferentiation of myoblasts into ventral longitudinal muscles. Our results provide new insights into mechanisms of lineage commitment and cell-fate plasticity during development. Copyright © 2015 Elsevier Ltd. All rights reserved.

Selector genes display tumor cooperation and inhibition in Drosophila epithelium in a developmental context-dependent manner

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Ram Prakash Gupta

2017-11-01

Full Text Available During animal development, selector genes determine identities of body segments and those of individual organs. Selector genes are also misexpressed in cancers, although their contributions to tumor progression per se remain poorly understood. Using a model of cooperative tumorigenesis, we show that gain of selector genes results in tumor cooperation, but in only select developmental domains of the wing, haltere and eye-antennal imaginal discs of Drosophila larva. Thus, the field selector, Eyeless (Ey, and the segment selector, Ultrabithorax (Ubx, readily cooperate to bring about neoplastic transformation of cells displaying somatic loss of the tumor suppressor, Lgl, but in only those developmental domains that express the homeo-box protein, Homothorax (Hth, and/or the Zinc-finger protein, Teashirt (Tsh. In non-Hth/Tsh-expressing domains of these imaginal discs, however, gain of Ey in lgl− somatic clones induces neoplastic transformation in the distal wing disc and haltere, but not in the eye imaginal disc. Likewise, gain of Ubx in lgl− somatic clones induces transformation in the eye imaginal disc but not in its endogenous domain, namely, the haltere imaginal disc. Our results reveal that selector genes could behave as tumor drivers or inhibitors depending on the tissue contexts of their gains.

Extracellular matrix components expression in human pluripotent stem cell-derived retinal organoids recapitulates retinogenesis in vivo and reveals an important role for IMPG1 and CD44 in the development of photoreceptors and interphotoreceptor matrix.

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Felemban, Majed; Dorgau, Birthe; Hunt, Nicola Claire; Hallam, Dean; Zerti, Darin; Bauer, Roman; Ding, Yuchun; Collin, Joseph; Steel, David; Krasnogor, Natalio; Al-Aama, Jumana; Lindsay, Susan; Mellough, Carla; Lako, Majlinda

2018-05-17

, IMPG1 & IMPG2 in the developing interphotoreceptor matrix (IPM). Retinal organoids were successfully generated from pluripotent stem cells. The expression of ECM components was examined in the retinal organoids and found to recapitulate human retinal development in vivo. Using functional blocking experiments, we were able to highlight an important role for IMPG1 and CD44 in the development of photoreceptors and IPM formation. Copyright © 2018 Acta Materialia Inc. All rights reserved.

K-RasV14I recapitulates Noonan syndrome in mice

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Hernández-Porras, Isabel; Fabbiano, Salvatore; Schuhmacher, Alberto J.; Aicher, Alexandra; Cañamero, Marta; Cámara, Juan Antonio; Cussó, Lorena; Desco, Manuel; Heeschen, Christopher; Mulero, Francisca; Bustelo, Xosé R.; Guerra, Carmen; Barbacid, Mariano

2014-01-01

Noonan syndrome (NS) is an autosomal dominant genetic disorder characterized by short stature, craniofacial dysmorphism, and congenital heart defects. NS also is associated with a risk for developing myeloproliferative disorders (MPD), including juvenile myelomonocytic leukemia (JMML). Mutations responsible for NS occur in at least 11 different loci including KRAS. Here we describe a mouse model for NS induced by K-RasV14I, a recurrent KRAS mutation in NS patients. K-RasV14I–mutant mice displayed multiple NS-associated developmental defects such as growth delay, craniofacial dysmorphia, cardiac defects, and hematologic abnormalities including a severe form of MPD that resembles human JMML. Homozygous animals had perinatal lethality whose penetrance varied with genetic background. Exposure of pregnant mothers to a MEK inhibitor rescued perinatal lethality and prevented craniofacial dysmorphia and cardiac defects. However, Mek inhibition was not sufficient to correct these defects when mice were treated after weaning. Interestingly, Mek inhibition did not correct the neoplastic MPD characteristic of these mutant mice, regardless of the timing at which the mice were treated, thus suggesting that MPD is driven by additional signaling pathways. These genetically engineered K-RasV14I–mutant mice offer an experimental tool for studying the molecular mechanisms underlying the clinical manifestations of NS. Perhaps more importantly, they should be useful as a preclinical model to test new therapies aimed at preventing or ameliorating those deficits associated with this syndrome. PMID:25359213

Human pancreatic cancer xenografts recapitulate key aspects of cancer cachexia.

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Delitto, Daniel; Judge, Sarah M; Delitto, Andrea E; Nosacka, Rachel L; Rocha, Fernanda G; DiVita, Bayli B; Gerber, Michael H; George, Thomas J; Behrns, Kevin E; Hughes, Steven J; Wallet, Shannon M; Judge, Andrew R; Trevino, Jose G

2017-01-03

Cancer cachexia represents a debilitating syndrome that diminishes quality of life and augments the toxicities of conventional treatments. Cancer cachexia is particularly debilitating in patients with pancreatic cancer (PC). Mechanisms responsible for cancer cachexia are under investigation and are largely derived from observations in syngeneic murine models of cancer which are limited in PC. We evaluate the effect of human PC cells on both muscle wasting and the systemic inflammatory milieu potentially contributing to PC-associated cachexia. Specifically, human PC xenografts were generated by implantation of pancreatic cancer cells, L3.6pl and PANC-1, either in the flank or orthotopically within the pancreas. Mice bearing orthotopic xenografts demonstrated significant muscle wasting and atrophy-associated gene expression changes compared to controls. Further, despite the absence of adaptive immunity, splenic tissue from orthotopically engrafted mice demonstrated elevations in several pro-inflammatory cytokines associated with cancer cachexia, including TNFα, IL1β, IL6 and KC (murine IL8 homologue), when compared to controls. Therefore, data presented here support further investigation into the complexity of cancer cachexia in PC to identify potential targets for this debilitating syndrome.

America, guns, and freedom. Part I: A recapitulation of liberty.

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Faria, Miguel A

2012-01-01

The role of gun violence and street crime in the United States and the world is currently a subject of great debate among national and international organizations, including the United Nations. Because the Second Amendment to the U.S. Constitution protects the individual right of American citizens to own private firearms, availability of firearms is greater in the U.S. than the rest of the world, except perhaps in Israel and Switzerland. Indeed, although the American people continue to purchase and possess more firearms, homicides and violent crimes have continued to diminish for several decades because guns in the hands of the law-abiding citizens does not translate into more crime. As neurosurgeons, we can be compassionate and still be honest and have the moral courage to pursue the truth and find viable solutions through the use of sound, scholarly research in the area of guns and violence. We have an obligation to reach our conclusions based on objective data and scientific information rather than on ideology, emotionalism or partisan politics.

Genetic and Environmental Control of Neurodevelopmental Robustness in Drosophila.

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David J Mellert

Full Text Available Interindividual differences in neuronal wiring may contribute to behavioral individuality and affect susceptibility to neurological disorders. To investigate the causes and potential consequences of wiring variation in Drosophila melanogaster, we focused on a hemilineage of ventral nerve cord interneurons that exhibits morphological variability. We find that late-born subclasses of the 12A hemilineage are highly sensitive to genetic and environmental variation. Neurons in the second thoracic segment are particularly variable with regard to two developmental decisions, whereas its segmental homologs are more robust. This variability "hotspot" depends on Ultrabithorax expression in the 12A neurons, indicating variability is cell-intrinsic and under genetic control. 12A development is more variable and sensitive to temperature in long-established laboratory strains than in strains recently derived from the wild. Strains with a high frequency of one of the 12A variants also showed a high frequency of animals with delayed spontaneous flight initiation, whereas other wing-related behaviors did not show such a correlation and were thus not overtly affected by 12A variation. These results show that neurodevelopmental robustness is variable and under genetic control in Drosophila and suggest that the fly may serve as a model for identifying conserved gene pathways that stabilize wiring in stressful developmental environments. Moreover, some neuronal lineages are variation hotspots and thus may be more amenable to evolutionary change.

Small ubiquitin-like modifier (SUMO) conjugation impedes transcriptional silencing by the polycomb group repressor Sex Comb on Midleg.

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Smith, Matthew; Mallin, Daniel R; Simon, Jeffrey A; Courey, Albert J

2011-04-01

The Drosophila protein Sex Comb on Midleg (Scm) is a member of the Polycomb group (PcG), a set of transcriptional repressors that maintain silencing of homeotic genes during development. Recent findings have identified PcG proteins both as targets for modification by the small ubiquitin-like modifier (SUMO) protein and as catalytic components of the SUMO conjugation pathway. We have found that the SUMO-conjugating enzyme Ubc9 binds to Scm and that this interaction, which requires the Scm C-terminal sterile α motif (SAM) domain, is crucial for the efficient sumoylation of Scm. Scm is associated with the major Polycomb response element (PRE) of the homeotic gene Ultrabithorax (Ubx), and efficient PRE recruitment requires an intact Scm SAM domain. Global reduction of sumoylation augments binding of Scm to the PRE. This is likely to be a direct effect of Scm sumoylation because mutations in the SUMO acceptor sites in Scm enhance its recruitment to the PRE, whereas translational fusion of SUMO to the Scm N terminus interferes with this recruitment. In the metathorax, Ubx expression promotes haltere formation and suppresses wing development. When SUMO levels are reduced, we observe decreased expression of Ubx and partial haltere-to-wing transformation phenotypes. These observations suggest that SUMO negatively regulates Scm function by impeding its recruitment to the Ubx major PRE.

Small Ubiquitin-like Modifier (SUMO) Conjugation Impedes Transcriptional Silencing by the Polycomb Group Repressor Sex Comb on Midleg*

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Smith, Matthew; Mallin, Daniel R.; Simon, Jeffrey A.; Courey, Albert J.

2011-01-01

The Drosophila protein Sex Comb on Midleg (Scm) is a member of the Polycomb group (PcG), a set of transcriptional repressors that maintain silencing of homeotic genes during development. Recent findings have identified PcG proteins both as targets for modification by the small ubiquitin-like modifier (SUMO) protein and as catalytic components of the SUMO conjugation pathway. We have found that the SUMO-conjugating enzyme Ubc9 binds to Scm and that this interaction, which requires the Scm C-terminal sterile α motif (SAM) domain, is crucial for the efficient sumoylation of Scm. Scm is associated with the major Polycomb response element (PRE) of the homeotic gene Ultrabithorax (Ubx), and efficient PRE recruitment requires an intact Scm SAM domain. Global reduction of sumoylation augments binding of Scm to the PRE. This is likely to be a direct effect of Scm sumoylation because mutations in the SUMO acceptor sites in Scm enhance its recruitment to the PRE, whereas translational fusion of SUMO to the Scm N terminus interferes with this recruitment. In the metathorax, Ubx expression promotes haltere formation and suppresses wing development. When SUMO levels are reduced, we observe decreased expression of Ubx and partial haltere-to-wing transformation phenotypes. These observations suggest that SUMO negatively regulates Scm function by impeding its recruitment to the Ubx major PRE. PMID:21278366

Giant hub Src and Syk tyrosine kinase thermodynamic profiles recapitulate evolution

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Phillips, J. C.

2017-10-01

Thermodynamic scaling theory, previously applied mainly to small proteins, here analyzes quantitative evolution of the titled functional network giant hub enzymes. The broad domain structure identified homologically is confirmed hydropathically using amino acid sequences only. The most surprising results concern the evolution of the tyrosine kinase globular surface roughness from avians to mammals, which is first order, compared to the evolution within mammals from rodents to humans, which is second order. The mystery of the unique amide terminal region of proto oncogene tyrosine protein kinase is resolved by the discovery there of a rare hydroneutral septad targeting cluster, which is paralleled by an equally rare octad catalytic cluster in tyrosine kinase in humans and a few other species (cat and dog). These results, which go far towards explaining why these proteins are among the largest giant hubs in protein interaction networks, use no adjustable parameters.

78 FR 8546 - National Center for Advancing Translational Sciences (NCATS) and National Human Genome Research...

Science.gov (United States)

2013-02-06

... March 8, 2013 for consideration. Guidelines for the preparation of a full CRADA proposal will be... recapitulates the pathologic hallmarks of Gaucher disease,'' Panicker LM, Miller D, Park TS, Patel B, Azevedo JL...

Fine Mapping of a Degenerated Abdominal Legs Mutant (Edl in Silkworm, Bombyx mori.

Directory of Open Access Journals (Sweden)

Honglei Wang

Full Text Available In insects, abdominal appendages, also called prolegs, vary due to adaptive evolution. Mutations on prolegs within species provide insights to better understand the mechanisms underlying appendage development and diversity. In silkworm Bombyx mori, extra-crescents and degenerated abdominal legs (Edl mutant, belonging to the E pseudoallele group, is a spontaneous mutation that adds crescents and degenerates prolegs on the third abdominal segment (A3. This mutation may be a homeotic transformation of A3 to A2. In this study, the Edl locus was mapped within approximately a 211 Kb region that is 10 Kb upstream of Bmabdominal-A (Bmabd-A. RT-quantitative PCR (RT-qPCR and Western blot analysis of Bmabd-A expression showed a slight but significant decrease, while the expression of BmUltrabithorax (BmUbx was up-regulated in the Edl mutant compared to wildtype (Dazao. Moreover, we also found that BmDistal-less (BmDll, which regulated the development of distal proleg structures, was missing at the tips of the A3 prolegs in the Edl mutant compared to BmDll expression in normally developed prolegs in both the wildtype and mutant. Collectively, we identified approximately a 211 Kb region in the Edl locus that regulates BmUbx and Bmabd-A expression and found that changes in BmUbx and Bmabd-A expression may lead to the loss of distal proleg structures in B. mori.

A Rat Model of Sytemic Chemotherapy for Breast Cancer to Evaluate and Treat Chemobrain

National Research Council Canada - National Science Library

Little, Kevin C

2007-01-01

...) that recapitulates the physical symptoms of chemotherapy treatment. We investigated the effects of this regimen on learning and memory as well as on the production and survival of new neurons in the hippocampus (neurogenesis...

Water Buffalo (Bubalus bubalis) as a spontaneous animal model of Vitiligo.

Science.gov (United States)

Singh, Vijay Pal; Motiani, Rajender K; Singh, Archana; Malik, Garima; Aggarwal, Rangoli; Pratap, Kunal; Wani, Mohan R; Gokhale, Suresh B; Natarajan, Vivek T; Gokhale, Rajesh S

2016-07-01

Vitiligo is a multifactorial acquired depigmenting disorder. Recent insights into the molecular mechanisms driving the gradual destruction of melanocytes in vitiligo will likely lead to the discovery of novel therapies, which need to be evaluated in animal models that closely recapitulate the pathogenesis of human vitiligo. In humans, vitiligo is characterized by a spontaneous loss of functional melanocytes from the epidermis, but most animal models of vitiligo are either inducible or genetically programmed. Here, we report that acquired depigmentation in water buffalo recapitulates molecular, histological, immunohistochemical, and ultrastructural changes observed in human vitiligo and hence could be used as a model to study vitiligo pathogenesis and facilitate the discovery and evaluation of therapeutic interventions for vitiligo. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Integrating light-sheet imaging with virtual reality to recapitulate developmental cardiac mechanics.

Science.gov (United States)

Ding, Yichen; Abiri, Arash; Abiri, Parinaz; Li, Shuoran; Chang, Chih-Chiang; Baek, Kyung In; Hsu, Jeffrey J; Sideris, Elias; Li, Yilei; Lee, Juhyun; Segura, Tatiana; Nguyen, Thao P; Bui, Alexander; Sevag Packard, René R; Fei, Peng; Hsiai, Tzung K

2017-11-16

Currently, there is a limited ability to interactively study developmental cardiac mechanics and physiology. We therefore combined light-sheet fluorescence microscopy (LSFM) with virtual reality (VR) to provide a hybrid platform for 3D architecture and time-dependent cardiac contractile function characterization. By taking advantage of the rapid acquisition, high axial resolution, low phototoxicity, and high fidelity in 3D and 4D (3D spatial + 1D time or spectra), this VR-LSFM hybrid methodology enables interactive visualization and quantification otherwise not available by conventional methods, such as routine optical microscopes. We hereby demonstrate multiscale applicability of VR-LSFM to (a) interrogate skin fibroblasts interacting with a hyaluronic acid-based hydrogel, (b) navigate through the endocardial trabecular network during zebrafish development, and (c) localize gene therapy-mediated potassium channel expression in adult murine hearts. We further combined our batch intensity normalized segmentation algorithm with deformable image registration to interface a VR environment with imaging computation for the analysis of cardiac contraction. Thus, the VR-LSFM hybrid platform demonstrates an efficient and robust framework for creating a user-directed microenvironment in which we uncovered developmental cardiac mechanics and physiology with high spatiotemporal resolution.

Recapitulation of premature ageing with iPSCs from Hutchinson-Gilford progeria syndrome.

Science.gov (United States)

Liu, Guang-Hui; Barkho, Basam Z; Ruiz, Sergio; Diep, Dinh; Qu, Jing; Yang, Sheng-Lian; Panopoulos, Athanasia D; Suzuki, Keiichiro; Kurian, Leo; Walsh, Christopher; Thompson, James; Boue, Stephanie; Fung, Ho Lim; Sancho-Martinez, Ignacio; Zhang, Kun; Yates, John; Izpisua Belmonte, Juan Carlos

2011-04-14

Hutchinson-Gilford progeria syndrome (HGPS) is a rare and fatal human premature ageing disease, characterized by premature arteriosclerosis and degeneration of vascular smooth muscle cells (SMCs). HGPS is caused by a single point mutation in the lamin A (LMNA) gene, resulting in the generation of progerin, a truncated splicing mutant of lamin A. Accumulation of progerin leads to various ageing-associated nuclear defects including disorganization of nuclear lamina and loss of heterochromatin. Here we report the generation of induced pluripotent stem cells (iPSCs) from fibroblasts obtained from patients with HGPS. HGPS-iPSCs show absence of progerin, and more importantly, lack the nuclear envelope and epigenetic alterations normally associated with premature ageing. Upon differentiation of HGPS-iPSCs, progerin and its ageing-associated phenotypic consequences are restored. Specifically, directed differentiation of HGPS-iPSCs to SMCs leads to the appearance of premature senescence phenotypes associated with vascular ageing. Additionally, our studies identify DNA-dependent protein kinase catalytic subunit (DNAPKcs, also known as PRKDC) as a downstream target of progerin. The absence of nuclear DNAPK holoenzyme correlates with premature as well as physiological ageing. Because progerin also accumulates during physiological ageing, our results provide an in vitro iPSC-based model to study the pathogenesis of human premature and physiological vascular ageing.

A 3D Microfluidic Model to Recapitulate Cancer Cell Migration and Invasion

Directory of Open Access Journals (Sweden)

Yi-Chin Toh

2018-04-01

Full Text Available We have developed a microfluidic-based culture chip to simulate cancer cell migration and invasion across the basement membrane. In this microfluidic chip, a 3D microenvironment is engineered to culture metastatic breast cancer cells (MX1 in a 3D tumor model. A chemo-attractant was incorporated to stimulate motility across the membrane. We validated the usefulness of the chip by tracking the motilities of the cancer cells in the system, showing them to be migrating or invading (akin to metastasis. It is shown that our system can monitor cell migration in real time, as compare to Boyden chambers, for example. Thus, the chip will be of interest to the drug-screening community as it can potentially be used to monitor the behavior of cancer cell motility, and, therefore, metastasis, in the presence of anti-cancer drugs.

Ageing and recurrent episodes of neuroinflammation promote progressive experimental autoimmune encephalomyelitis in Biozzi ABH mice

NARCIS (Netherlands)

Peferoen, Laura A. N.; Breur, Marjolein; van de Berg, Sarah; Peferoen-Baert, Regina; Boddeke, Erik H. W. G. M.; van der Valk, Paul; Pryce, Gareth; van Noort, Johannes M.; Baker, David; Amor, Sandra

2016-01-01

Current therapies for multiple sclerosis (MS) reduce the frequency of relapses by modulating adaptive immune responses but fail to limit the irreversible neurodegeneration driving progressive disability. Experimental autoimmune encephalomyelitis (EAE) in Biozzi ABH mice recapitulates clinical

In Vivo SILAC-Based Proteomics Reveals Phosphoproteome Changes during Mouse Skin Carcinogenesis

NARCIS (Netherlands)

Zanivan, S.; Meves, A.; Behrendt, K.; Schoof, E.M.; Neilson, L.J.; Cox, J.; Tang, H.R.; Kalna, G.; Ree, J.H. van; Deursen, J.M.A. van; Trempus, C.S.; Machesky, L.M.; Linding, R.; Wickstrom, S.A.; Fassler, R.; Mann, M.

2013-01-01

Cancer progresses through distinct stages, and mouse models recapitulating traits of this progression are frequently used to explore genetic, morphological, and pharmacological aspects of tumor development. To complement genomic investigations of this process, we here quantify phosphoproteomic

Model organoids provide new research opportunities for ductal pancreatic cancer

NARCIS (Netherlands)

Boj, Sylvia F; Hwang, Chang-Il; Baker, Lindsey A; Engle, Dannielle D; Tuveson, David A; Clevers, Hans

We recently established organoid models from normal and neoplastic murine and human pancreas tissues. These organoids exhibit ductal- and disease stage-specific characteristics and, after orthotopic transplantation, recapitulate the full spectrum of tumor progression. Pancreatic organoid technology

Melt Electrospinning Writing of Poly-Hydroxymethylglycolide-co-ε-Caprolactone-Based Scaffolds for Cardiac Tissue Engineering

NARCIS (Netherlands)

Castilho, Miguel; Feyen, Dries; Flandes-Iparraguirre, María; Hochleitner, Gernot; Groll, Jürgen; Doevendans, Pieter A.F.; Vermonden, Tina; Ito, Keita; Sluijter, Joost P G; Malda, Jos

2017-01-01

Current limitations in cardiac tissue engineering revolve around the inability to fully recapitulate the structural organization and mechanical environment of native cardiac tissue. This study aims at developing organized ultrafine fiber scaffolds with improved biocompatibility and architecture in

Melt Electrospinning Writing of Poly-Hydroxymethylglycolide-co-ε-Caprolactone-Based Scaffolds for Cardiac Tissue Engineering

NARCIS (Netherlands)

Castilho, Miguel; Feyen, Dries; Flandes-Iparraguirre, María; Hochleitner, Gernot; Groll, Jürgen; Doevendans, Pieter A.F.; Vermonden, Tina; Ito, Keita; Sluijter, Joost P.G.; Malda, Jos

Current limitations in cardiac tissue engineering revolve around the inability to fully recapitulate the structural organization and mechanical environment of native cardiac tissue. This study aims at developing organized ultrafine fiber scaffolds with improved biocompatibility and architecture in

Melt electrospinning writing of poly-Hydroxymethylglycolide-co-ε-Caprolactone-based scaffolds for cardiac tissue engineering

NARCIS (Netherlands)

Castilho, M.; Feyen, D.; Flandes-Iparraguirre, M.; Hochleitner, G.; Groll, J.; Doevendans, P.A.F.; Vermonden, T.; Ito, K.; Sluijter, J.P.G.; Malda, J.

2017-01-01

Current limitations in cardiac tissue engineering revolve around the inability to fully recapitulate the structural organization and mechanical environment of native cardiac tissue. This study aims at developing organized ultrafine fiber scaffolds with improved biocompatibility and architecture in

Reverse engineering the mechanical and molecular pathways in stem cell morphogenesis.

Science.gov (United States)

Lu, Kai; Gordon, Richard; Cao, Tong

2015-03-01

The formation of relevant biological structures poses a challenge for regenerative medicine. During embryogenesis, embryonic cells differentiate into somatic tissues and undergo morphogenesis to produce three-dimensional organs. Using stem cells, we can recapitulate this process and create biological constructs for therapeutic transplantation. However, imperfect imitation of nature sometimes results in in vitro artifacts that fail to recapitulate the function of native organs. It has been hypothesized that developing cells may self-organize into tissue-specific structures given a correct in vitro environment. This proposition is supported by the generation of neo-organoids from stem cells. We suggest that morphogenesis may be reverse engineered to uncover its interacting mechanical pathway and molecular circuitry. By harnessing the latent architecture of stem cells, novel tissue-engineering strategies may be conceptualized for generating self-organizing transplants. Copyright © 2013 John Wiley & Sons, Ltd.

Organoid technology for brain and therapeutics research.

Science.gov (United States)

Wang, Zhi; Wang, Shu-Na; Xu, Tian-Ying; Miao, Zhu-Wei; Su, Ding-Feng; Miao, Chao-Yu

2017-10-01

Brain is one of the most complex organs in human. The current brain research is mainly based on the animal models and traditional cell culture. However, the inherent species differences between humans and animals as well as the gap between organ level and cell level make it difficult to study human brain development and associated disorders through traditional technologies. Recently, the brain organoids derived from pluripotent stem cells have been reported to recapitulate many key features of human brain in vivo, for example recapitulating the zone of putative outer radial glia cells. Brain organoids offer a new platform for scientists to study brain development, neurological diseases, drug discovery and personalized medicine, regenerative medicine, and so on. Here, we discuss the progress, applications, advantages, limitations, and prospects of brain organoid technology in neurosciences and related therapeutics. © 2017 John Wiley & Sons Ltd.

ASSESSMENT OF CHEMICAL EFFECTS ON NEURITE OUTGROWTH, NEURONAL POLARIZATION AND SYNAPTOGENESIS IN RAT CORTICAL NEURONS USING HIGH CONTENT IMAGE ANALYSIS

Science.gov (United States)

There is a need for efficient, cost-effective methods for screening and prioritization of potential developmental neurotoxicants. One approach uses in vitro cell culture models that can recapitulate the critical processes of nervous system development. In vitro, primary cultures ...

The bio in the ink : cartilage regeneration with bioprintable hydrogels and articular cartilage-derived progenitor cells

NARCIS (Netherlands)

Levato, Riccardo; Webb, William R; Otto, Iris A; Mensinga, Anneloes; Zhang, Yadan; van Rijen, Mattie; van Weeren, P. René; Khan, Ilyas M.; Malda, Jos

2017-01-01

Cell-laden hydrogels are the primary building blocks for bioprinting, and, also termed bioinks, are the foundations for creating structures that can potentially recapitulate the architecture of articular cartilage. To be functional, hydrogel constructs need to unlock the regenerative capacity of

Systems Toxicology of Embryo Development (9th Copenhagen Workshop)

Science.gov (United States)

An important consideration for predictive toxicology is to identify developmental hazards utilizing mechanism-based in vitro assays (e.g., ToxCast) and in silico multiscale models. Steady progress has been made with agent-based models that recapitulate morphogenetic drivers for a...

The initiation of embryonic-like collagen fibrillogenesis by adult human tendon fibroblasts when cultured under tension

DEFF Research Database (Denmark)

Bayer, Monika L; Yeung, Chin-Yan C; Kadler, Karl E

2010-01-01

Tendon fibroblasts synthesize collagen and form fibrils during embryonic development, but to what extent mature fibroblasts are able to recapitulate embryonic development and develop normal tendon structure is unknown. The present study examined the capability of mature human tendon fibroblasts t...

Personalized Proteome Profiles of Healthy and Tumor Human Colon Organoids Reveal Both Individual Diversity and Basic Features of Colorectal Cancer

NARCIS (Netherlands)

Cristobal Gonzalez de Durana, Alba|info:eu-repo/dai/nl/338769706; van den Toorn, Henk W P|info:eu-repo/dai/nl/31093205X; van de Wetering, Marc; Clevers, Hans|info:eu-repo/dai/nl/07164282X; Heck, Albert J R|info:eu-repo/dai/nl/105189332; Mohammed, Shabaz|info:eu-repo/dai/nl/30483632X

2017-01-01

Diseases at the molecular level are complex and patient dependent, necessitating development of strategies that enable precision treatment to optimize clinical outcomes. Organoid technology has recently been shown to have the potential to recapitulate the in vivo characteristics of the original

IN VITRO SCREENING OF DEVELOPMENTAL NEUROTOXICANTS IN RAT PRIMARY CORTICAL NEURONS USING HIGH CONTENT IMAGE

Science.gov (United States)

There is a need for more efficient and cost-effective methods for identifying, characterizing and prioritizing chemicals which may result in developmental neurotoxicity. One approach is to utilize in vitro test systems which recapitulate the critical processes of nervous system d...

9 CFR 203.4 - Statement with respect to the disposition of records by packers, live poultry dealers, stockyard...

Science.gov (United States)

2010-01-01

... sheets; scale tickets received from others; inventory and products in storage; receiving records; trial... slips; production or sale tonnage reports (including recapitulations and summaries of routes, branches... sales invoices, or claims or credit memoranda; and Provided further, That microfilm copies of records...

Current and anticipated uses of the CATHARE code at EDF and FRAMATOME

Energy Technology Data Exchange (ETDEWEB)

Gandrille, J.L.; Vacher, J.L.; Poizat, F.

1997-07-01

This paper presents current industrial applications of the CATHARE code in the fields of Safety Studies and Simulators where the code is intensively used by FRAMATOME, EDF and CEA, the development partners of CATHARE. Future needs in these fields are also recapitulated.

Cardiomyocytes derived from embryonic stem cells resemble cardiomyocytes of the embryonic heart tube

NARCIS (Netherlands)

Fijnvandraat, Arnoud C.; van Ginneken, Antoni C. G.; de Boer, Piet A. J.; Ruijter, Jan M.; Christoffels, Vincent M.; Moorman, Antoon F. M.; Lekanne Deprez, Ronald H.

2003-01-01

OBJECTIVE: After formation of the linear heart tube a chamber-specific program of gene expression becomes active that underlies the formation of the chamber myocardium. To assess whether this program is recapitulated in in vitro differentiated embryonic stem cells, we performed qualitative and

Designer matrices for intestinal stem cell and organoid culture

NARCIS (Netherlands)

Gjorevski, Nikolce; Sachs, Norman; Manfrin, Andrea; Giger, Sonja; Bragina, Maiia E.; Ordóñez-Morán, Paloma; Clevers, Hans; Lutolf, Matthias P.

2016-01-01

Epithelial organoids recapitulate multiple aspects of real organs, making them promising models of organ development, function and disease. However, the full potential of organoids in research and therapy has remained unrealized, owing to the poorly defined animal-derived matrices in which they are

Computational Model of Secondary Palate Fusion and Disruption

Science.gov (United States)

Morphogenetic events are driven by cell-generated physical forces and complex cellular dynamics. To improve our capacity to predict developmental effects from cellular alterations, we built a multi-cellular agent-based model in CompuCell3D that recapitulates the cellular networks...

Prognostic factors in pediatric pulmonary arterial hypertension : A systematic review and meta-analysis

NARCIS (Netherlands)

Ploegstra, Mark-Jan; Zijlstra, Willemijn M. H.; Douwes, Johannes M.; Hillege, Hans L.; Berger, Rolf M. F.

2015-01-01

BACKGROUND: Despite the introduction of targeted therapies in pediatric pulmonary arterial hypertension (PAH), prognosis remains poor. For the definition of treatment strategies and guidelines, there is a high need for an evidence-based recapitulation of prognostic factors. The aim of this study was

Current and anticipated uses of the CATHARE code at EDF and FRAMATOME

International Nuclear Information System (INIS)

Gandrille, J.L.; Vacher, J.L.; Poizat, F.

1997-01-01

This paper presents current industrial applications of the CATHARE code in the fields of Safety Studies and Simulators where the code is intensively used by FRAMATOME, EDF and CEA, the development partners of CATHARE. Future needs in these fields are also recapitulated

D-galactose-induced brain ageing model

DEFF Research Database (Denmark)

Sadigh-Eteghad, Saeed; Majdi, Alireza; McCann, Sarah K.

2017-01-01

Animal models are commonly used in brain ageing research. Amongst these, models where rodents are exposed to d-galactose are held to recapitulate a number of features of ageing including neurobehavioral and neurochemical changes. However, results from animal studies are often inconsistent...

Isolation and differentiation of stromal vascular cells to beige/brite cells

DEFF Research Database (Denmark)

Aune, Ulrike Liisberg; Ruiz, Lauren; Kajimura, Shingo

2013-01-01

cold exposure or by PPARγ agonists, therefore, this cell type has potential as a therapeutic target for obesity treatment. Although most immortalized adipocyte lines cannot recapitulate the process of "browning" of white fat in culture, primary adipocytes isolated from stromal vascular fraction...

Generation of an inducible colon-specific Cre enzyme mouse line for colon cancer research

NARCIS (Netherlands)

Tetteh, Paul W.; Kretzschmar, Kai; Begthel, Harry; Van Den Born, Maaike; Korving, Jeroen; Morsink, Folkert; Farin, Henner; Van Es, Johan H.; Offerhaus, G. Johan A; Clevers, Hans

2016-01-01

Current mouse models for colorectal cancer often differ significantly from human colon cancer, being largely restricted to the small intestine. Here, we aim to develop a colon-specific inducible mouse model that can faithfully recapitulate human colon cancer initiation and progression. Carbonic

Squaramide-based supramolecular materials for three-dimensional cell culture of human induced pluripotent stem cells and their derivatives

NARCIS (Netherlands)

Tong, Ciqing; Liu, Tingxian; Saez Talens, Victorio; Noteborn, Willem E.M.; Sharp, Thomas H.; Hendrix, Marco M.R.M.; Voets, Ilja K.; Mummery, Christine L.; Orlova, Valeria V.; Kieltyka, Roxanne E.

2018-01-01

Synthetic hydrogel materials can recapitulate the natural cell microenvironment; however, it is equally necessary that the gels maintain cell viability and phenotype while permitting reisolation without stress, especially for use in the stem cell field. Here, we describe a family of synthetically

Generation of BAC Transgenic Epithelial Organoids

NARCIS (Netherlands)

Schwank, G.; Andersson-Rolf, A.; Koo, B.K.; Sasaki, N.; Clevers, H.

2013-01-01

Under previously developed culture conditions, mouse and human intestinal epithelia can be cultured and expanded over long periods. These so-called organoids recapitulate the three-dimensional architecture of the gut epithelium, and consist of all major intestinal cell types. One key advantage of

Personalized Proteome Profiles of Healthy and Tumor Human Colon Organoids Reveal Both Individual Diversity and Basic Features of Colorectal Cancer

NARCIS (Netherlands)

Cristobal, Alba; van den Toorn, Henk W.P.; van de Wetering, Marc; Clevers, Hans; Heck, Albert J R; Mohammed, Shabaz

2017-01-01

Diseases at the molecular level are complex and patient dependent, necessitating development of strategies that enable precision treatment to optimize clinical outcomes. Organoid technology has recently been shown to have the potential to recapitulate the in vivo characteristics of the original

A Nineteenth-Century French Proposal to Use School Vouchers.

Science.gov (United States)

Van Vliet, W.; Smyth, J. A.

1982-01-01

In light of the current American interest in school vouchers as proposed by economist Milton Friedman, recapitulates the origins, content, and fate of an 1872 law drafted by a French parliamentary commission to establish a countrywide voucher scheme for primary schools. (NEC)

Loss-less Nano-fractionator for High Sensitivity, High Coverage Proteomics

DEFF Research Database (Denmark)

Kulak, Nils A; Geyer, Philipp E; Mann, Matthias

2017-01-01

automated and in-depth characterization of 12 different human cell lines to a median depth of 11,472 different proteins, which revealed differences recapitulating their developmental origin and differentiation status. The fractionation technology described here is flexible, easy to use, and facilitates...

Markers of murine embryonic and neural stem cells, neurons and astrocytes: reference points for developmental neurotoxicity testing

Science.gov (United States)

Developmental neurotoxicity (DNT) is a significant concern for environmental chemicals, as well as for food and drug constituents. The sensitivity of animal-based DNT models is unclear, and they are expensive and time consuming. Murine embryonic stem cells (mESC) recapitulate sev...

Molecular phenotyping of human ovarian cancer stem cells unravels the mechanisms for repair and chemoresistance

DEFF Research Database (Denmark)

Alvero, Ayesha B; Chen, Rui; Fu, Han-Hsuan

2009-01-01

A major burden in the treatment of ovarian cancer is the high percentage of recurrence and chemoresistance. Cancer stem cells (CSCs) provide a reservoir of cells that can self-renew, can maintain the tumor by generating differentiated cells [non-stem cells (non-CSCs)] which make up the bulk...... to form spheroids in suspension, and the ability to recapitulate in vivo the original tumor. Chemotherapy eliminates the bulk of the tumor but it leaves a core of cancer cells with high capacity for repair and renewal. The molecular properties identified in these cells may explain some of the unique...... of the tumor and may be the primary source of recurrence. We describe the characterization of human ovarian cancer stem cells (OCSCs). These cells have a distinctive genetic profile that confers them with the capacity to recapitulate the original tumor, proliferate with chemotherapy, and promote recurrence...

3D culture models of Alzheimer's disease: a road map to a "cure-in-a-dish".

Science.gov (United States)

Choi, Se Hoon; Kim, Young Hye; Quinti, Luisa; Tanzi, Rudolph E; Kim, Doo Yeon

2016-12-09

Alzheimer's disease (AD) transgenic mice have been used as a standard AD model for basic mechanistic studies and drug discovery. These mouse models showed symbolic AD pathologies including β-amyloid (Aβ) plaques, gliosis and memory deficits but failed to fully recapitulate AD pathogenic cascades including robust phospho tau (p-tau) accumulation, clear neurofibrillary tangles (NFTs) and neurodegeneration, solely driven by familial AD (FAD) mutation(s). Recent advances in human stem cell and three-dimensional (3D) culture technologies made it possible to generate novel 3D neural cell culture models that recapitulate AD pathologies including robust Aβ deposition and Aβ-driven NFT-like tau pathology. These new 3D human cell culture models of AD hold a promise for a novel platform that can be used for mechanism studies in human brain-like environment and high-throughput drug screening (HTS). In this review, we will summarize the current progress in recapitulating AD pathogenic cascades in human neural cell culture models using AD patient-derived induced pluripotent stem cells (iPSCs) or genetically modified human stem cell lines. We will also explain how new 3D culture technologies were applied to accelerate Aβ and p-tau pathologies in human neural cell cultures, as compared the standard two-dimensional (2D) culture conditions. Finally, we will discuss a potential impact of the human 3D human neural cell culture models on the AD drug-development process. These revolutionary 3D culture models of AD will contribute to accelerate the discovery of novel AD drugs.

Fischer-344 Tp53-knockout rats exhibit a high rate of bone and brain neoplasia with frequent metastasis

Directory of Open Access Journals (Sweden)

Sarah A. Hansen

2016-10-01

Full Text Available Somatic mutations in the Tp53 tumor suppressor gene are the most commonly seen genetic alterations in cancer, and germline mutations in Tp53 predispose individuals to a variety of early-onset cancers. Development of appropriate translational animal models that carry mutations in Tp53 and recapitulate human disease are important for drug discovery, biomarker development and disease modeling. Current Tp53 mouse and rat models have significant phenotypic and genetic limitations, and often do not recapitulate certain aspects of human disease. We used a marker-assisted speed congenic approach to transfer a well-characterized Tp53-mutant allele from an outbred rat to the genetically inbred Fischer-344 (F344 rat to create the F344-Tp53tm1(EGFP-PacQly/Rrrc (F344-Tp53 strain. On the F344 genetic background, the tumor spectrum shifted, with the primary tumor types being osteosarcomas and meningeal sarcomas, compared to the hepatic hemangiosarcoma and lymphoma identified in the original outbred stock model. The Fischer model is more consistent with the early onset of bone and central nervous system sarcomas found in humans with germline Tp53 mutations. The frequency of osteosarcomas in F344-Tp53 homozygous and heterozygous animals was 57% and 36%, respectively. Tumors were highly representative of human disease radiographically and histologically, with tumors found primarily on long bones with frequent pulmonary metastases. Importantly, the rapid onset of osteosarcomas in this promising new model fills a current void in animal models that recapitulate human pediatric osteosarcomas and could facilitate studies to identify therapeutic targets.

Sliding contact loading enhances the tensile properties of mesenchymal stem cell-seeded hydrogels

Directory of Open Access Journals (Sweden)

AH Huang

2012-07-01

Full Text Available The primary goal of cartilage tissue engineering is to recapitulate the functional properties and structural features of native articular cartilage. While there has been some success in generating near-native compressive properties, the tensile properties of cell-seeded constructs remain poor, and key features of cartilage, including inhomogeneity and anisotropy, are generally absent in these engineered constructs. Therefore, in an attempt to instill these hallmark properties of cartilage in engineered cell-seeded constructs, we designed and characterized a novel sliding contact bioreactor to recapitulate the mechanical stimuli arising from physiologic joint loading (two contacting cartilage layers. Finite element modeling of this bioreactor system showed that tensile strains were direction-dependent, while both tensile strains and fluid motion were depth-dependent and highest in the region closest to the contact surface. Short-term sliding contact of mesenchymal stem cell (MSC-seeded agarose improved chondrogenic gene expression in a manner dependent on both the axial strain applied and transforming growth factor-β supplementation. Using the optimized loading parameters derived from these short-term studies, long-term sliding contact was applied to MSC-seeded agarose constructs for 21 d. After 21 d, sliding contact significantly improved the tensile properties of MSC-seeded constructs and elicited alterations in type II collagen and proteoglycan accumulation as a function of depth; staining for these matrix molecules showed intense localization in the surface regions. These findings point to the potential of sliding contact to produce engineered cartilage constructs that begin to recapitulate the complex mechanical features of the native tissue.

Quantitative imaging of epithelial cell scattering identifies specific inhibitors of cell motility and cell-cell dissociation

NARCIS (Netherlands)

Loerke, D.; le Duc, Q.; Blonk, I.; Kerstens, A.; Spanjaard, E.; Machacek, M.; Danuser, G.; de Rooij, J.

2012-01-01

The scattering of cultured epithelial cells in response to hepatocyte growth factor (HGF) is a model system that recapitulates key features of metastatic cell behavior in vitro, including disruption of cell-cell adhesions and induction of cell migration. We have developed image analysis tools that

Gastroesophageal and biliary reflux. 10

International Nuclear Information System (INIS)

Bares, Roland; Buell, Udalrich

1991-01-01

After a brief recapitulation of reflux pathogenesis, this review presents the state of the art of nuclear medicine techniques to diagnose gastroesophageal or duodenogastric reflux, as well as a summary of clinical results and considerations about indication. (author).53 refs.; 5 figs.; 8 tabs

Variants in Nebulin (NEB) Are Linked to the Development of Familial Primary Angle Closure Glaucoma in Basset Hounds

NARCIS (Netherlands)

Ahram, D.F.; Grozdanic, S.D.; Kecova, H.; Henkes, A.; Collin, R.W.J.; Kuehn, M.H.

2015-01-01

Several dog breeds are susceptible to developing primary angle closure glaucoma (PACG), which suggests a genetic basis for the disease. We have identified a four-generation Basset Hound pedigree with characteristic autosomal recessive PACG that closely recapitulates PACG in humans. Our aim is to

Embryonic stem cells as an ectodermal cellular model of human p63-related dysplasia syndromes.

NARCIS (Netherlands)

Rostagno, P.; Wolchinsky, Z.; Vigano, A.M.; Shivtiel, S.; Zhou, Huiqing; Bokhoven, J.H.L.M. van; Ferone, G.; Missero, C.; Mantovani, R.; Aberdam, D.; Virolle, T.

2010-01-01

Heterozygous mutations in the TP63 transcription factor underlie the molecular basis of several similar autosomal dominant ectodermal dysplasia (ED) syndromes. Here we provide a novel cellular model derived from embryonic stem (ES) cells that recapitulates in vitro the main steps of embryonic skin

Unsettling Melodies: A Cognitive Approach to Incongruent Film Music

NARCIS (Netherlands)

Willemsen, Steven; Kiss, Miklós

2013-01-01

Incongruent film music is a soundtrack, either diegetic or non- diegetic, which expresses qualities that stand in contrast to the emotions evoked by the events seen. The present article aims at covering two interconnected areas; the first is comprised of a critical recapitulation of available

Remodeling of cortical bone allografts mediated by adherent rAAV-RANKL and VEGF gene therapy

DEFF Research Database (Denmark)

Ito, H; Koefoed, M; Tiyapatanaputi, P

2005-01-01

Structural allograft healing is limited because of a lack of vascularization and remodeling. To study this we developed a mouse model that recapitulates the clinical aspects of live autograft and processed allograft healing. Gene expression analyses showed that there is a substantial decrease in ...

A survey of computer-based approaches for greenhouse climate management.

NARCIS (Netherlands)

Schotman, P.J.

1996-01-01

This study recapitulates research efforts that have addressed the restricted problem of greenhouse climate management. This problem is first analyzed by looking at the current working method of the grower and the characteristics of this management task. The different attempts to automate parts of

Kisspeptins: bridging energy homeostasis and reproduction

DEFF Research Database (Denmark)

Castellano, Juan M; Bentsen, Agnete H; Mikkelsen, Jens D

2010-01-01

RH neurons. This review recapitulates the experimental evidence obtained to date, mostly in laboratory rodents, supporting the function of kisspeptins in bridging energy balance and reproduction, with special emphasis on recent developments in this field, such as the recognition of mTOR (mammalian target...

Epithelial self-healing is recapitulated by a 3D biomimetic E-cadherin junction

NARCIS (Netherlands)

Cohen, Daniel J.; Gloerich, Martijn; Nelson, W. James

2016-01-01

Epithelial monolayers undergo self-healing when wounded. During healing, cells collectively migrate into the wound site, and the converging tissue fronts collide and form a stable interface. To heal, migrating tissues must form cell-cell adhesions and reorganize from the front-rear polarity

Epithelial self-healing is recapitulated by a 3D biomimetic E-cadherin junction.

Science.gov (United States)

Cohen, Daniel J; Gloerich, Martijn; Nelson, W James

2016-12-20

Epithelial monolayers undergo self-healing when wounded. During healing, cells collectively migrate into the wound site, and the converging tissue fronts collide and form a stable interface. To heal, migrating tissues must form cell-cell adhesions and reorganize from the front-rear polarity characteristic of cell migration to the apical-basal polarity of an epithelium. However, identifying the "stop signal" that induces colliding tissues to cease migrating and heal remains an open question. Epithelial cells form integrin-based adhesions to the basal extracellular matrix (ECM) and E-cadherin-mediated cell-cell adhesions on the orthogonal, lateral surfaces between cells. Current biological tools have been unable to probe this multicellular 3D interface to determine the stop signal. We addressed this problem by developing a unique biointerface that mimicked the 3D organization of epithelial cell adhesions. This "minimal tissue mimic" (MTM) comprised a basal ECM substrate and a vertical surface coated with purified extracellular domain of E-cadherin, and was designed for collision with the healing edge of an epithelial monolayer. Three-dimensional imaging showed that adhesions formed between cells, and the E-cadherin-coated MTM resembled the morphology and dynamics of native epithelial cell-cell junctions and induced the same polarity transition that occurs during epithelial self-healing. These results indicate that E-cadherin presented in the proper 3D context constitutes a minimum essential stop signal to induce self-healing. That the Ecad:Fc MTM stably integrated into an epithelial tissue and reduced migration at the interface suggests that this biointerface is a complimentary approach to existing tissue-material interfaces.

Epithelial self-healing is recapitulated by a 3D biomimetic E-cadherin junction

OpenAIRE

Cohen, Daniel J.; Gloerich, Martijn; Nelson, W. James

2016-01-01

Epithelial monolayers undergo self-healing when wounded. During healing, cells collectively migrate into the wound site, and the converging tissue fronts collide and form a stable interface. To heal, migrating tissues must form cell-cell adhesions and reorganize from the front-rear polarity characteristic of cell migration to the apicalbasal polarity of an epithelium. However, identifying the "stop signal" that induces colliding tissues to cease migrating and heal remains an open question. Ep...

Phage morphology recapitulates phylogeny: the comparative genomics of a new group of myoviruses.

Directory of Open Access Journals (Sweden)

André M Comeau

Full Text Available Among dsDNA tailed bacteriophages (Caudovirales, members of the Myoviridae family have the most sophisticated virion design that includes a complex contractile tail structure. The Myoviridae generally have larger genomes than the other phage families. Relatively few "dwarf" myoviruses, those with a genome size of less than 50 kb such as those of the Mu group, have been analyzed in extenso. Here we report on the genome sequencing and morphological characterization of a new group of such phages that infect a diverse range of Proteobacteria, namely Aeromonas salmonicida phage 56, Vibrio cholerae phages 138 and CP-T1, Bdellovibrio phage φ1422, and Pectobacterium carotovorum phage ZF40. This group of dwarf myoviruses shares an identical virion morphology, characterized by usually short contractile tails, and have genome sizes of approximately 45 kb. Although their genome sequences are variable in their lysogeny, replication, and host adaption modules, presumably reflecting differing lifestyles and hosts, their structural and morphogenesis modules have been evolutionarily constrained by their virion morphology. Comparative genomic analysis reveals that these phages, along with related prophage genomes, form a new coherent group within the Myoviridae. The results presented in this communication support the hypothesis that the diversity of phages may be more structured than generally believed and that the innumerable phages in the biosphere all belong to discrete lineages or families.

A Novel Mouse Model of a Patient Mucolipidosis II Mutation Recapitulates Disease Pathology*

OpenAIRE

Paton, Leigh; Bitoun, Emmanuelle; Kenyon, Janet; Priestman, David A.; Oliver, Peter L.; Edwards, Benjamin; Platt, Frances M.; Davies, Kay E.

2014-01-01

Mucolipidosis II (MLII) is a lysosomal storage disorder caused by loss of N-acetylglucosamine-1-phosphotransferase, which tags lysosomal enzymes with a mannose 6-phosphate marker for transport to the lysosome. In MLII, the loss of this marker leads to deficiency of multiple enzymes and non-enzymatic proteins in the lysosome, leading to the storage of multiple substrates. Here we present a novel mouse model of MLII homozygous for a patient mutation in the GNPTAB gene. Whereas the current gene ...

Cortex shatters the glass ceiling.

Science.gov (United States)

Au, Edmund; Fishell, Gord

2008-11-06

Recreating developmental structures in vitro has been a primary challenge for stem cell biologists. Recent studies in Cell Stem Cell (Eiraku et al., 2008) and Nature (Gaspard et al., 2008) demonstrate that embryonic stem cells can recapitulate early cortical development, enabling them to generate specific cortical subtypes.

Computer Simulation of Embryonic Systems: What can a virtual embryo teach us about developmental toxicity? (LA Conference on Computational Biology & Bioinformatics)

Science.gov (United States)

This presentation will cover work at EPA under the CSS program for: (1) Virtual Tissue Models built from the known biology of an embryological system and structured to recapitulate key cell signals and responses; (2) running the models with real (in vitro) or synthetic (in silico...

A presentation of four cases of organisational learning in a steam cracker. An exploration of organisational learning.

NARCIS (Netherlands)

Pauwels, Fernando; Van Ruysseveldt, Joris

2010-01-01

In this paper we will first recapitulate our theoretical framework and provide a definition of organisational learning, which will be further expanded on, amongst others by making use of a number of criteria, which have been developed by the Orglearn research consortium. After this short theoretical

Clubbed fingers: the claws we lost?

NARCIS (Netherlands)

Brouwers, A.A.M.; Vermeij-Keers, C.; Zoelen, E.J.J. van; Gooren, L.J.G.

2004-01-01

Clubbed digits resemble the human embryonic fingers and toes, which took like the digits of a claw. Clubbed digits, thus, may represent the return of the embryonic claw and may even represent the claws man has lost during evolution, if ontogenesis realty recapitulates phylogenesis. We put forward

T-cells contribute to hypertension but not to renal injury in mice with subtotal nephrectomy

NARCIS (Netherlands)

Oosterhuis, Nynke R.; Papazova, Diana A.; Gremmels, Hendrik; Joles, Jaap A.; Verhaar, Marianne C.

2017-01-01

Background: The pathological condition of chronic kidney disease may not be adequately recapitulated in immunocompromised mice due to the lack of T-cells, which are important for the development of hypertension and renal injury. We studied the role of the immune system in relation to salt-sensitive

Organoid cultures derived from patients with advanced prostate cancer

NARCIS (Netherlands)

Gao, Dong; Vela, Ian; Sboner, Andrea; Iaquinta, Phillip J; Karthaus, Wouter R; Gopalan, Anuradha; Dowling, Catherine; Wanjala, Jackline N; Undvall, Eva A; Arora, Vivek K; Wongvipat, John; Kossai, Myriam; Ramazanoglu, Sinan; Barboza, Luendreo P; Di, Wei; Cao, Zhen; Zhang, Qi Fan; Sirota, Inna; Ran, Leili; MacDonald, Theresa Y; Beltran, Himisha; Mosquera, Juan-Miguel; Touijer, Karim A; Scardino, Peter T; Laudone, Vincent P; Curtis, Kristen R; Rathkopf, Dana E; Morris, Michael J; Danila, Daniel C; Slovin, Susan F; Solomon, Stephen B; Eastham, James A; Chi, Ping; Carver, Brett; Rubin, Mark A; Scher, Howard I; Clevers, Hans; Sawyers, Charles L; Chen, Yu

2014-01-01

The lack of in vitro prostate cancer models that recapitulate the diversity of human prostate cancer has hampered progress in understanding disease pathogenesis and therapy response. Using a 3D organoid system, we report success in long-term culture of prostate cancer from biopsy specimens and

Examples of electrostatic electron optics: The Farrand and Elektros microscopes and electron mirrors

International Nuclear Information System (INIS)

Hawkes, P.W.

2012-01-01

The role of Gertrude Rempfer in the design of the Farrand and Elektros microscopes is evoked. The study of electron mirror optics, aberration correction using mirrors and the development of microscopes employing electron mirrors are recapitulated, accompanied by a full bibliography, of earlier publications in particular.

Periarteriolar Glioblastoma Stem Cell Niches Express Bone Marrow Hematopoietic Stem Cell Niche Proteins

NARCIS (Netherlands)

Hira, Vashendriya V. V.; Wormer, Jill R.; Kakar, Hala; Breznik, Barbara; van der Swaan, Britt; Hulsbos, Renske; Tigchelaar, Wikky; Tonar, Zbynek; Khurshed, Mohammed; Molenaar, Remco J.; van Noorden, Cornelis J. F.

2018-01-01

In glioblastoma, a fraction of malignant cells consists of therapy-resistant glioblastoma stem cells (GSCs) residing in protective niches that recapitulate hematopoietic stem cell (HSC) niches in bone marrow. We have previously shown that HSC niche proteins stromal cell-derived factor-1α (SDF-1α),

YAP/TAZ-Dependent Reprogramming of Colonic Epithelium Links ECM Remodeling to Tissue Regeneration

DEFF Research Database (Denmark)

Yui, Shiro; Azzolin, Luca; Maimets, Martti

2018-01-01

by remodeling the extracellular matrix (ECM), increased FAK/Src signaling, and ultimately YAP/TAZ activation. In a defined cell culture system recapitulating the extracellular matrix remodeling observed in vivo, we show that a collagen 3D matrix supplemented with Wnt ligands is sufficient to sustain endogenous...

EFFORTS TO INCREASE THE ABILITY TO CHOOSE A SCHOOL GROUP COUNSELING SERVICES THROUGH ADVANCED CLASS IX SMP NEGERI 2 METRO STATE IN 2013

Directory of Open Access Journals (Sweden)

Rohima Rohima

2016-06-01

Full Text Available SMP Negeri 2 Metro In reality, there are many confused students choose a major program of advanced studies, especially for junior high school students. It is necessary to learn / coaching to the students to be able to choose the school accordingly. Researchers conduct action research through the Guidance Counseling Group in Class IX student of SMP Negeri 2 Metro. The experiment was conducted using two cycles. Recapitulation of data Selecting a program majoring in the process of learning / coaching from the first cycle to the second cycle, there is an increase of 57.06% to 86.35%. The results of the data summary portfolio also increased from 33.32% to 83.33%, and the recapitulation of learning outcomes of students who otherwise Completed Pass also risen from 54.54% increase to 96.96%. Thus concluded indicator of success is to reach the target / as are 95% or more. Keywords: guidance group, select schools, smp negeri 2 metro

Aging stem cells. A Werner syndrome stem cell model unveils heterochromatin alterations as a driver of human aging.

Science.gov (United States)

Zhang, Weiqi; Li, Jingyi; Suzuki, Keiichiro; Qu, Jing; Wang, Ping; Zhou, Junzhi; Liu, Xiaomeng; Ren, Ruotong; Xu, Xiuling; Ocampo, Alejandro; Yuan, Tingting; Yang, Jiping; Li, Ying; Shi, Liang; Guan, Dee; Pan, Huize; Duan, Shunlei; Ding, Zhichao; Li, Mo; Yi, Fei; Bai, Ruijun; Wang, Yayu; Chen, Chang; Yang, Fuquan; Li, Xiaoyu; Wang, Zimei; Aizawa, Emi; Goebl, April; Soligalla, Rupa Devi; Reddy, Pradeep; Esteban, Concepcion Rodriguez; Tang, Fuchou; Liu, Guang-Hui; Belmonte, Juan Carlos Izpisua

2015-06-05

Werner syndrome (WS) is a premature aging disorder caused by WRN protein deficiency. Here, we report on the generation of a human WS model in human embryonic stem cells (ESCs). Differentiation of WRN-null ESCs to mesenchymal stem cells (MSCs) recapitulates features of premature cellular aging, a global loss of H3K9me3, and changes in heterochromatin architecture. We show that WRN associates with heterochromatin proteins SUV39H1 and HP1α and nuclear lamina-heterochromatin anchoring protein LAP2β. Targeted knock-in of catalytically inactive SUV39H1 in wild-type MSCs recapitulates accelerated cellular senescence, resembling WRN-deficient MSCs. Moreover, decrease in WRN and heterochromatin marks are detected in MSCs from older individuals. Our observations uncover a role for WRN in maintaining heterochromatin stability and highlight heterochromatin disorganization as a potential determinant of human aging. Copyright © 2015, American Association for the Advancement of Science.

Manipulation of in vitro collagen matrix architecture for scaffolds of improved physiological relevance

Science.gov (United States)

Hapach, Lauren A.; VanderBurgh, Jacob A.; Miller, Joseph P.; Reinhart-King, Cynthia A.

2015-12-01

Type I collagen is a versatile biomaterial that is widely used in medical applications due to its weak antigenicity, robust biocompatibility, and its ability to be modified for a wide array of applications. As such, collagen has become a major component of many tissue engineering scaffolds, drug delivery platforms, and substrates for in vitro cell culture. In these applications, collagen constructs are fabricated to recapitulate a diverse set of conditions. Collagen fibrils can be aligned during or post-fabrication, cross-linked via numerous techniques, polymerized to create various fibril sizes and densities, and copolymerized into a wide array of composite scaffolds. Here, we review approaches that have been used to tune collagen to better recapitulate physiological environments for use in tissue engineering applications and studies of basic cell behavior. We discuss techniques to control fibril alignment, methods for cross-linking collagen constructs to modulate stiffness, and composite collagen constructs to better mimic physiological extracellular matrix.

Stereotactic intracranial implantation and in vivo bioluminescent imaging of tumor xenografts in a mouse model system of glioblastoma multiforme.

Science.gov (United States)

Baumann, Brian C; Dorsey, Jay F; Benci, Joseph L; Joh, Daniel Y; Kao, Gary D

2012-09-25

Glioblastoma multiforme (GBM) is a high-grade primary brain cancer with a median survival of only 14.6 months in humans despite standard tri-modality treatment consisting of surgical resection, post-operative radiation therapy and temozolomide chemotherapy. New therapeutic approaches are clearly needed to improve patient survival and quality of life. The development of more effective treatment strategies would be aided by animal models of GBM that recapitulate human disease yet allow serial imaging to monitor tumor growth and treatment response. In this paper, we describe our technique for the precise stereotactic implantation of bio-imageable GBM cancer cells into the brains of nude mice resulting in tumor xenografts that recapitulate key clinical features of GBM. This method yields tumors that are reproducible and are located in precise anatomic locations while allowing in vivo bioluminescent imaging to serially monitor intracranial xenograft growth and response to treatments. This method is also well-tolerated by the animals with low perioperative morbidity and mortality.

Fabrication of Trabecular Bone-Templated Tissue-Engineered Constructs by 3D Inkjet Printing.

Science.gov (United States)

Vanderburgh, Joseph P; Fernando, Shanik J; Merkel, Alyssa R; Sterling, Julie A; Guelcher, Scott A

2017-11-01

3D printing enables the creation of scaffolds with precisely controlled morphometric properties for multiple tissue types, including musculoskeletal tissues such as cartilage and bone. Computed tomography (CT) imaging has been combined with 3D printing to fabricate anatomically scaled patient-specific scaffolds for bone regeneration. However, anatomically scaled scaffolds typically lack sufficient resolution to recapitulate the 3D constructs are fabricated via a new micro-CT/3D inkjet printing process. It is shown that this process reproducibly fabricates bone-templated constructs that recapitulate the anatomic site-specific morphometric properties of trabecular bone. A significant correlation is observed between the structure model index (a morphometric parameter related to surface curvature) and the degree of mineralization of human mesenchymal stem cells, with more concave surfaces promoting more extensive osteoblast differentiation and mineralization compared to predominately convex surfaces. These findings highlight the significant effects of trabecular architecture on osteoblast function. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

A multifunctional 3D co-culture system for studies of mammary tissue morphogenesis and stem cell biology.

Directory of Open Access Journals (Sweden)

Jonathan J Campbell

Full Text Available Studies on the stem cell niche and the efficacy of cancer therapeutics require complex multicellular structures and interactions between different cell types and extracellular matrix (ECM in three dimensional (3D space. We have engineered a 3D in vitro model of mammary gland that encompasses a defined, porous collagen/hyaluronic acid (HA scaffold forming a physiologically relevant foundation for epithelial and adipocyte co-culture. Polarized ductal and acinar structures form within this scaffold recapitulating normal tissue morphology in the absence of reconstituted basement membrane (rBM hydrogel. Furthermore, organoid developmental outcome can be controlled by the ratio of collagen to HA, with a higher HA concentration favouring acinar morphological development. Importantly, this culture system recapitulates the stem cell niche as primary mammary stem cells form complex organoids, emphasising the utility of this approach for developmental and tumorigenic studies using genetically altered animals or human biopsy material, and for screening cancer therapeutics for personalised medicine.

An investigation of brand choice processes

NARCIS (Netherlands)

Wierenga, B.

1974-01-01

Here a brief recapitulation of the study of brand choice processes is given, and the major conclusions are reported.

In chapter 2 we discussed the empirical brand choice data used throughout the study. We saw that these were purchase histories of members of the Dutch Attwood

Sex disparity in colonic adenomagenesis involves promotion by male hormones, not protection by female hormones

NARCIS (Netherlands)

Amos-Landgraf, James M.; Heijmans, Jarom; Wielenga, Mattheus C. B.; Dunkin, Elisa; Krentz, Kathy J.; Clipson, Linda; Ederveen, Antwan G.; Groothuis, Patrick G.; Mosselman, Sietse; Muncan, Vanesa; Hommes, Daniel W.; Shedlovsky, Alexandra; Dove, William F.; van den Brink, Gijs R.

2014-01-01

It recently has been recognized that men develop colonic adenomas and carcinomas at an earlier age and at a higher rate than women. In the Apc(Pirc/+) (Pirc) rat model of early colonic cancer, this sex susceptibility was recapitulated, with male Pirc rats developing twice as many adenomas as

Biomechanical Strain Exacerbates Inflammation on a Progeria-on-a-Chip Model

NARCIS (Netherlands)

Ribas, J.; Zhang, Y.S.; Pitrez, P.R.; Leijten, Jeroen Christianus Hermanus; Miscuglio, M.; Rouwkema, Jeroen; Dokmeci, M.R.; Nissan, X.; Ferreira, L.; Khademhosseini, A.

2017-01-01

A progeria-on-a-chip model is engineered to recapitulate the biomechanical dynamics of vascular disease and aging. The model shows an exacerbated injury response to strain and is rescued by pharmacological treatments. The progeria-on-a-chip is expected to drive the discovery of new drugs and to

Animal models of antineutrophil cytoplasm antibody-associated vasculitis.

LENUS (Irish Health Repository)

Salama, Alan D

2012-01-01

To provide an update on the experimental models that have been developed recapitulating clinical antineutrophil cytoplasm antibody (ANCA) associated vasculitis. The application of the models in the study of pathogenesis, and the therapeutic implications of this, are covered in the article by van Timmeren and Heeringa in this issue.

Communication and Education in a Virtual World: Avatar-Mediated Teaching and Learning in Second Life

Science.gov (United States)

Mon, Lorri

2010-01-01

Education within Second Life frequently recapitulates the "sage on the stage" as students sit their avatars down in chairs in the virtual world and listen to or read an instructor's lecture while watching a slideshow. This conceptual article explores alternative active learning techniques supporting independent and collaborative learning…

Implications of a neural network model of early sensori-motor development for the field of developmental neurology

NARCIS (Netherlands)

van Heijst, JJ; Touwen, BCL; Vos, JE

This paper reports on a neural network model for early sensori-motor development and on the possible implications of this research for our understanding and, eventually, treatment of motor disorders like cerebral palsy. We recapitulate the results we published in detail in a series of papers [1-4].

Functional properties of hepatocytes in vitro are correlated with cell polarity maintenance.

Science.gov (United States)

Zeigerer, Anja; Wuttke, Anne; Marsico, Giovanni; Seifert, Sarah; Kalaidzidis, Yannis; Zerial, Marino

2017-01-01

Exploring the cell biology of hepatocytes in vitro could be a powerful strategy to dissect the molecular mechanisms underlying the structure and function of the liver in vivo. However, this approach relies on appropriate in vitro cell culture systems that can recapitulate the cell biological and metabolic features of the hepatocytes in the liver whilst being accessible to experimental manipulations. Here, we adapted protocols for high-resolution fluorescence microscopy and quantitative image analysis to compare two primary hepatocyte culture systems, monolayer and collagen sandwich, with respect to the distribution of two distinct populations of early endosomes (APPL1 and EEA1-positive), endocytic capacity, metabolic and signaling activities. In addition to the re-acquisition of hepatocellular polarity, primary hepatocytes grown in collagen sandwich but not in monolayer culture recapitulated the apico-basal distribution of EEA1 endosomes observed in liver tissue. We found that such distribution correlated with the organization of the actin cytoskeleton in vitro and, surprisingly, was dependent on the nutritional state in vivo. Hepatocytes in collagen sandwich also exhibited faster kinetics of low-density lipoprotein (LDL) and epidermal growth factor (EGF) internalization, showed improved insulin sensitivity and preserved their ability for glucose production, compared to hepatocytes in monolayer cultures. Although no in vitro culture system can reproduce the exquisite structural features of liver tissue, our data nevertheless highlight the ability of the collagen sandwich system to recapitulate key structural and functional properties of the hepatocytes in the liver and, therefore, support the usage of this system to study aspects of hepatocellular biology in vitro. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Why Is She Naked?

DEFF Research Database (Denmark)

Rodil, Kasper; Winschiers-Theophilus, Heike

2018-01-01

with a refinement of the previously presented Tripartite Digitisation Model (TDM). We begin by providing a short recapitulation of the TDM originally published in Vol. 10, with an emphasis on the role of evaluations. This model is exemplified with a concrete example of digitisation of ICH together with an Ova...

The Oncopig Cancer Model: An Innovative Large Animal Translational Oncology Platform

DEFF Research Database (Denmark)

Schachtschneider, Kyle M.; Schwind, Regina M.; Newson, Jordan

2017-01-01

-the Oncopig Cancer Model (OCM)-as a next-generation large animal platform for the study of hematologic and solid tumor oncology. With mutations in key tumor suppressor and oncogenes, TP53R167H and KRASG12D , the OCM recapitulates transcriptional hallmarks of human disease while also exhibiting clinically...

Multiparton interactions and multiparton distributions in QCD

Energy Technology Data Exchange (ETDEWEB)

Diehl, Markus

2011-11-15

After a brief recapitulation of the general interest of parton densities, we discuss multiple hard interactions and multiparton distributions. We report on recent theoretical progress in their QCD description, on outstanding conceptual problems and on possibilities to use multiparton distributions as a laboratory to test and improve our understanding of hadron structure. (orig.)

On the Status of Logic in Piaget

Science.gov (United States)

Reginensi, Luc

2004-01-01

This article analyses the way in which Piaget links the analogy between the child and the primitive with a theory of the history of the sciences, that is, it analyses Piaget's version of Haeckel's principle in which ontogenesis recapitulates phylogenesis. From this analysis, we reconstitute the operations through which Piaget forms and expresses…

The Value of Vitalism and Schrodinger's "What Is Life?" in the Contemporary Classroom

Science.gov (United States)

Sitaraman, Ramakrishnan

2009-01-01

Classic experiments and novel ideas in the history of science are often mentioned in passing in contemporary college-level science curricula. This study indicates that the detailed and creative recapitulation of a few well-chosen and famous, if well-known, results and ideas has the potential to increase students' understanding and appreciation of…

Multiparton interactions and multiparton distributions in QCD

International Nuclear Information System (INIS)

Diehl, Markus

2011-11-01

After a brief recapitulation of the general interest of parton densities, we discuss multiple hard interactions and multiparton distributions. We report on recent theoretical progress in their QCD description, on outstanding conceptual problems and on possibilities to use multiparton distributions as a laboratory to test and improve our understanding of hadron structure. (orig.)

Main conclusions of a seminar on managing technical resources in a changing nuclear industry

International Nuclear Information System (INIS)

Storey, P.D.

2000-01-01

The author recapitulates the different points from I Mech E Conference (Managing Technical resources in a changing Nuclear Industry -London, 29 September 1999), as following: UK position, BNFL Magnox and AEAT, UK view from BEGL, view from WANO, UK view from UKAEA, USA view from PECO Energy, and view from OECD NEA

Paving the way towards complex blood-brain barrier models using pluripotent stem cells

DEFF Research Database (Denmark)

Lauschke, Karin; Frederiksen, Lise; Hall, Vanessa Jane

2017-01-01

, it is now possible to produce many cell types from the BBB and even partially recapitulate this complex tissue in vitro. In this review, we summarize the most recent developments in PSC differentiation and modelling of the BBB. We also suggest how patient-specific human induced PSCs could be used to model...

Synthesis and Chemistry of Organic Geminal Di- and Triazides.

Science.gov (United States)

Häring, Andreas P; Kirsch, Stefan F

2015-11-06

This review recapitulates all available literature dealing with the synthesis and reactivity of geminal organic di- and triazides. These compound classes are, to a large extent, unexplored despite their promising chemical properties and their simple preparation. In addition, the chemistry of carbonyl diazide (2) and tetraazidomethane (105) is described in separate sections.

Hox gene function and interaction in the milkweed bug Oncopeltus fasciatus (Hemiptera).

Science.gov (United States)

Angelini, David R; Liu, Paul Z; Hughes, Cynthia L; Kaufman, Thomas C

2005-11-15

Studies in genetic model organisms such as Drosophila have demonstrated that the homeotic complex (Hox) genes impart segmental identity during embryogenesis. Comparative studies in a wide range of other insect taxa have shown that the Hox genes are expressed in largely conserved domains along the anterior-posterior body axis, but whether they are performing the same functions in different insects is an open question. Most of the Hox genes have been studied functionally in only a few holometabolous insects that undergo metamorphosis. Thus, it is unclear how the Hox genes are functioning in the majority of direct-developing insects and other arthropods. To address this question, we used a combination of RNAi and in situ hybridization to reveal the expression, functions, and regulatory interactions of the Hox genes in the milkweed bug Oncopeltus fasciatus. Our results reveal many similarities and some interesting differences compared to Drosophila. We find that the gene Antennapedia is required for the identity of all three thoracic segments, while Ultrabithorax, abdominal-A and Abdominal-B cooperate to pattern the abdomen. The three abdominal genes exhibit posterior prevalence like in Drosophila, but apparently via some post-transcriptional mechanism. The functions of the head genes proboscipedia, Deformed, and Sex combs reduced were shown previously, and here we find that the complex temporal expression of pb in the labium is like that of other insects, but its regulatory relationship with Scr is unique. Overall, our data reveal that the evolution of insect Hox genes has included many small changes within general conservation of expression and function, and that the milkweed bug provides a useful model for understanding the roles of Hox genes in a direct-developing insect.

The late negative episodic memory effect: the effect of recapitulating study details at test.

Science.gov (United States)

Friedman, David; Cycowicz, Yael M; Bersick, Michael

2005-05-01

An hypothesis concerning mnemonic function suggests that perceptual details of previously experienced episodes are retrieved from the cortices that initially processed that information during the encoding phase. Cycowicz et al. [Cycowicz, Y.M., Friedman, D. and Snodgrass, J.G., Remembering the color of objects: an ERP investigation of source memory, Cereb Cortex, 11 (2001) 322-334.] have interpreted the presence of a late negative episodic memory (EM) effect, maximal over parieto-occipital scalp, as a brain signature of the search for and/or retrieval/evaluation of the specific perceptual source-specifying attributes (i.e., color) of pictures in the visual cortical regions that were recruited during the encoding of that information. The present study assessed the validity of this hypothesis. Twelve participants studied pictures outlined in red or green and were subsequently tested with inclusion (i.e., item; old or new regardless of color) and exclusion (i.e., source; same color, different color/new judgments) tasks. In both, old pictures were presented either in the same color as at study or in the alternate color. A late negative, parieto-occipital EM effect was of much larger amplitude in the source compared to the item task. It was of similar magnitude to correctly recognized pictures whose colors were identical at study and test relative to those whose colors changed, and was not modulated by the success or failure of the source retrieval. These data run counter to the initial hypothesis that the late negative EM effect reflects the search for and/or retrieval of specific perceptual attributes such as color. Rather, the late negative EM effect may reflect the search for and/or retrieval/evaluation of more general source-specifying information in the cortical regions that initially processed the stimuli.

Homeobox gene expression in adult dorsal root ganglia: Is regeneration a recapitulation of development?

NARCIS (Netherlands)

Vogelaar, C.F.

2003-01-01

Neurons of the peripheral nervous system are able to regenerate their peripheral axons after injury, leading to complete recovery of sensory and motor function. The sciatic nerve crush model is frequently used to study peripheral nerve regeneration. Sensory neurons in the dorsal root ganglia (DRGs)

Spontaneous 8bp Deletion in Nbeal2 Recapitulates the Gray Platelet Syndrome in Mice

Science.gov (United States)

Tomberg, Kärt; Khoriaty, Rami; Westrick, Randal J.; Fairfield, Heather E.; Reinholdt, Laura G.; Brodsky, Gary L.; Davizon-Castillo, Pavel; Ginsburg, David; Di Paola, Jorge

2016-01-01

During the analysis of a whole genome ENU mutagenesis screen for thrombosis modifiers, a spontaneous 8 base pair (bp) deletion causing a frameshift in exon 27 of the Nbeal2 gene was identified. Though initially considered as a plausible thrombosis modifier, this Nbeal2 mutation failed to suppress the synthetic lethal thrombosis on which the original ENU screen was based. Mutations in NBEAL2 cause Gray Platelet Syndrome (GPS), an autosomal recessive bleeding disorder characterized by macrothrombocytopenia and gray-appearing platelets due to lack of platelet alpha granules. Mice homozygous for the Nbeal2 8 bp deletion (Nbeal2gps/gps) exhibit a phenotype similar to human GPS, with significantly reduced platelet counts compared to littermate controls (p = 1.63 x 10−7). Nbeal2gps/gps mice also have markedly reduced numbers of platelet alpha granules and an increased level of emperipolesis, consistent with previously characterized mice carrying targeted Nbeal2 null alleles. These findings confirm previous reports, provide an additional mouse model for GPS, and highlight the potentially confounding effect of background spontaneous mutation events in well-characterized mouse strains. PMID:26950939

Spontaneous 8bp Deletion in Nbeal2 Recapitulates the Gray Platelet Syndrome in Mice.

Directory of Open Access Journals (Sweden)

Kärt Tomberg

Full Text Available During the analysis of a whole genome ENU mutagenesis screen for thrombosis modifiers, a spontaneous 8 base pair (bp deletion causing a frameshift in exon 27 of the Nbeal2 gene was identified. Though initially considered as a plausible thrombosis modifier, this Nbeal2 mutation failed to suppress the synthetic lethal thrombosis on which the original ENU screen was based. Mutations in NBEAL2 cause Gray Platelet Syndrome (GPS, an autosomal recessive bleeding disorder characterized by macrothrombocytopenia and gray-appearing platelets due to lack of platelet alpha granules. Mice homozygous for the Nbeal2 8 bp deletion (Nbeal2gps/gps exhibit a phenotype similar to human GPS, with significantly reduced platelet counts compared to littermate controls (p = 1.63 x 10-7. Nbeal2gps/gps mice also have markedly reduced numbers of platelet alpha granules and an increased level of emperipolesis, consistent with previously characterized mice carrying targeted Nbeal2 null alleles. These findings confirm previous reports, provide an additional mouse model for GPS, and highlight the potentially confounding effect of background spontaneous mutation events in well-characterized mouse strains.

Neo-sex chromosomes in the black muntjac recapitulate incipient evolution of mammalian sex chromosomes

DEFF Research Database (Denmark)

Zhou, Qi; Wang, Jun; Huang, Ling

2008-01-01

in coding regions of eight investigated genes as well as cis-regulatory regions of two housekeeping genes. In vivo assays characterized a neo-Y insertion in the promoter of the CLTC gene that causes a significant reduction in allelic expression. A neo-Y-linked deletion in the 3'-untranslated region of gene...

Does the peritumoral stroma of basal cell carcinoma recapitulate the follicular connective tissue sheath?

Science.gov (United States)

Sellheyer, Klaus; Krahl, Dieter

2011-07-01

There are compelling embryologic and anatomic relationships within adnexal tumors. However, these are mostly perceived within the epithelial component while the stromal component of the tumors is frequently overlooked. In postnatal skin, nestin is almost exclusively expressed in the perifollicular mesenchyme. This study examines the expression of this neuroepithelial stem cell protein in trichoblastoma/trichoepithelioma and in basal cell carcinoma (BCC), which is increasingly being viewed as follicular in nature. We employed standard immunohistochemical methods with three different antibodies to examine the expression of nestin in 25 BCCs and compared the staining pattern with that of 7 trichoblastomas and 11 trichoepitheliomas. Nestin is expressed in the peritumoral stroma of all tumors examined and is limited to the immediate layer of mesenchymal cells surrounding the tumor epithelium. In BCC, nestin-immunoreactive cells are found as a sheath of thin, spindled fibroblasts, while reactive cells are plump in trichoepitheliomas/trichoblastomas. We postulate that the peritumoral stroma of BCC imitates the perifollicular connective tissue sheath, while in contrast that of trichoepithelioma/trichoblastoma is similar to the papillary and immediate peripapillary follicular mesenchyme. Further functional and animal experimental studies are needed to test this hypothesis. Copyright © 2011 John Wiley & Sons A/S.

Pregnane X Receptor-Humanized Mice Recapitulate Gender Differences in Ethanol Metabolism but Not Hepatotoxicity.

Science.gov (United States)

Spruiell, Krisstonia; Gyamfi, Afua A; Yeyeodu, Susan T; Richardson, Ricardo M; Gonzalez, Frank J; Gyamfi, Maxwell A

2015-09-01

Both human and rodent females are more susceptible to developing alcoholic liver disease following chronic ethanol (EtOH) ingestion. However, little is known about the relative effects of acute EtOH exposure on hepatotoxicity in female versus male mice. The nuclear receptor pregnane X receptor (PXR; NR1I2) is a broad-specificity sensor with species-specific responses to toxic agents. To examine the effects of the human PXR on acute EtOH toxicity, the responses of male and female PXR-humanized (hPXR) transgenic mice administered oral binge EtOH (4.5 g/kg) were analyzed. Basal differences were observed between hPXR males and females in which females expressed higher levels of two principal enzymes responsible for EtOH metabolism, alcohol dehydrogenase 1 and aldehyde dehydrogenase 2, and two key mediators of hepatocyte replication and repair, cyclin D1 and proliferating cell nuclear antigen. EtOH ingestion upregulated hepatic estrogen receptor α, cyclin D1, and CYP2E1 in both genders, but differentially altered lipid and EtOH metabolism. Consistent with higher basal levels of EtOH-metabolizing enzymes, blood EtOH was more rapidly cleared in hPXR females. These factors combined to provide greater protection against EtOH-induced liver injury in female hPXR mice, as revealed by markers for liver damage, lipid peroxidation, and endoplasmic reticulum stress. These results indicate that female hPXR mice are less susceptible to acute binge EtOH-induced hepatotoxicity than their male counterparts, due at least in part to the relative suppression of cellular stress and enhanced expression of enzymes involved in both EtOH metabolism and hepatocyte proliferation and repair in hPXR females. U.S. Government work not protected by U.S. copyright.

The PRRT2 knockout mouse recapitulates the neurological diseases associated with PRRT2 mutations.

Science.gov (United States)

Michetti, Caterina; Castroflorio, Enrico; Marchionni, Ivan; Forte, Nicola; Sterlini, Bruno; Binda, Francesca; Fruscione, Floriana; Baldelli, Pietro; Valtorta, Flavia; Zara, Federico; Corradi, Anna; Benfenati, Fabio

2017-03-01

Heterozygous and rare homozygous mutations in PRoline-Rich Transmembrane protein 2 (PRRT2) underlie a group of paroxysmal disorders including epilepsy, kinesigenic dyskinesia episodic ataxia and migraine. Most of the mutations lead to impaired PRRT2 expression and/or function. Recently, an important role for PRTT2 in the neurotransmitter release machinery, brain development and synapse formation has been uncovered. In this work, we have characterized the phenotype of a mouse in which the PRRT2 gene has been constitutively inactivated (PRRT2 KO). β-galactosidase staining allowed to map the regional expression of PRRT2 that was more intense in the cerebellum, hindbrain and spinal cord, while it was localized to restricted areas in the forebrain. PRRT2 KO mice are normal at birth, but display paroxysmal movements at the onset of locomotion that persist in the adulthood. In addition, adult PRRT2 KO mice present abnormal motor behaviors characterized by wild running and jumping in response to audiogenic stimuli that are ineffective in wild type mice and an increased sensitivity to the convulsive effects of pentylentetrazol. Patch-clamp electrophysiology in hippocampal and cerebellar slices revealed specific effects in the cerebellum, where PRRT2 is highly expressed, consisting in a higher excitatory strength at parallel fiber-Purkinje cell synapses during high frequency stimulation. The results show that the PRRT2 KO mouse reproduces the motor paroxysms present in the human PRRT2-linked pathology and can be proposed as an experimental model for the study of the pathogenesis of the disease as well as for testing personalized therapeutic approaches. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

CRISPR/Cas9-mediated Dax1 knockout in the monkey recapitulates human AHC-HH.

Science.gov (United States)

Kang, Yu; Zheng, Bo; Shen, Bin; Chen, Yongchang; Wang, Lei; Wang, Jianying; Niu, Yuyu; Cui, Yiqiang; Zhou, Jiankui; Wang, Hong; Guo, Xuejiang; Hu, Bian; Zhou, Qi; Sha, Jiahao; Ji, Weizhi; Huang, Xingxu

2015-12-20

Mutations in the DAX1 locus cause X-linked adrenal hypoplasia congenita (AHC) and hypogonadotropic hypogonadism (HH), which manifest with primary adrenal insufficiency and incomplete or absent sexual maturation, respectively. The associated defects in spermatogenesis can range from spermatogenic arrest to Sertoli cell only syndrome. Conclusions from Dax1 knockout mouse models provide only limited insight into AHC/HH disease mechanisms, because mouse models exhibit more extensive abnormalities in testicular development, including disorganized and incompletely formed testis cords with decreased number of peritubular myoid cells and male-to-female sex reversal. We previously reported successful clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 (Cas9)-mediated genome targeting in cynomolgus monkeys. Here, we describe a male fetal monkey in which targeted genome editing using CRISPR/Cas9 produced Dax1-null mutations in most somatic tissues and in the gonads. This DAX1-deficient monkey displayed defects in adrenal gland development and abnormal testis architecture with small cords, expanded blood vessels and extensive fibrosis. Sertoli cell formation was not affected. This phenotype strongly resembles findings in human patients with AHC-HH caused by mutations in DAX1. We further detected upregulation of Wnt/β-catenin-VEGF signaling in the fetal Dax1-deficient testis, suggesting abnormal activation of signaling pathways in the absence of DAX1 as one mechanism of AHC-HH. Our study reveals novel insight into the role of DAX1 in HH and provides proof-of-principle for the generation of monkey models of human disease via CRISPR/Cas9-mediated gene targeting. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Practicing Good Habits, Grade 4.

Science.gov (United States)

Van Cong Lau; And Others

This illustrated textbook was designed for teaching civics and values to fourth grade students in Vietnam. It is divided into six chapters: (1) At School (recapitulation of the grade three program, friendship, respect for the teacher, team work, discipline, honor); (2) In the Street: Traffic Regulations; (3) At Home (the extended family spirit,…

iPSCs to the rescue in Alzheimer's research.

Science.gov (United States)

Choi, Se Hoon; Tanzi, Rudolph E

2012-03-02

A crucial limitation to our understanding of Alzheimer's disease has been the inability to test hypotheses on live, patient-specific neurons. A recent study in Nature by Israel et al. (2012) reports that iPSC-derived neurons from AD patients recapitulate multiple aspects of disease pathology. Copyright © 2012 Elsevier Inc. All rights reserved.

Multi parton interactions and multi parton distributions in QCD

International Nuclear Information System (INIS)

Diehl, M.

2012-01-01

After a brief recapitulation of the general interest of parton densities, we discuss multiple hard interactions and multi parton distributions. We report on recent theoretical progress in their QCD description, on outstanding conceptual problems and on possibilities to use multi parton distributions as a laboratory to test and improve our understanding of hadron structure. (author)

Manipulation of host factors optimizes the pathogenesis of western equine encephalitis virus infections in mice for antiviral drug development

Science.gov (United States)

Blakely, Pennelope K.; Delekta, Phillip C.; Miller, David J.; Irani, David N.

2014-01-01

While alphaviruses spread naturally via mosquito vectors, some can also be transmitted as aerosols making them potential bioterrorism agents. One such pathogen, western equine encephalitis virus (WEEV), causes fatal human encephalitis via multiple routes of infection and thus presumably via multiple mechanisms. Although WEEV also produces acute encephalitis in non-human primates, a small animal model that recapitulates features of human disease would be useful for both pathogenesis studies and to evaluate candidate antiviral therapies. We have optimized conditions to infect mice with a low passage isolate of WEEV, thereby allowing detailed investigation of virus tropism, replication, neuroinvasion, and neurovirulence. We find that host factors strongly influence disease outcome, and in particular that age, gender and genetic background all have significant effects on disease susceptibility independent of virus tropism or replication within the central nervous system. Our data show that experimental variables can be adjusted in mice to recapitulate disease features known to occur in both non-human primates and humans, thus aiding further study of WEEV pathogenesis and providing a realistic therapeutic window for antiviral drug delivery. PMID:25361697

Induction of superficial cortical layer neurons from mouse embryonic stem cells by valproic acid.

Science.gov (United States)

Juliandi, Berry; Abematsu, Masahiko; Sanosaka, Tsukasa; Tsujimura, Keita; Smith, Austin; Nakashima, Kinichi

2012-01-01

Within the developing mammalian cortex, neural progenitors first generate deep-layer neurons and subsequently more superficial-layer neurons, in an inside-out manner. It has been reported recently that mouse embryonic stem cells (mESCs) can, to some extent, recapitulate cortical development in vitro, with the sequential appearance of neurogenesis markers resembling that in the developing cortex. However, mESCs can only recapitulate early corticogenesis; superficial-layer neurons, which are normally produced in later developmental periods in vivo, are under-represented. This failure of mESCs to reproduce later corticogenesis in vitro implies the existence of crucial factor(s) that are absent or uninduced in existing culture systems. Here we show that mESCs can give rise to superficial-layer neurons efficiently when treated with valproic acid (VPA), a histone deacetylase inhibitor. VPA treatment increased the production of Cux1-positive superficial-layer neurons, and decreased that of Ctip2-positive deep-layer neurons. These results shed new light on the mechanisms of later corticogenesis. Copyright © 2011 Elsevier Ireland Ltd and the Japan Neuroscience Society. All rights reserved.

Three-dimensional bioprinting using self-assembling scalable scaffold-free “tissue strands” as a new bioink

Science.gov (United States)

Yu, Yin; Moncal, Kazim K.; Li, Jianqiang; Peng, Weijie; Rivero, Iris; Martin, James A.; Ozbolat, Ibrahim T.

2016-01-01

Recent advances in bioprinting have granted tissue engineers the ability to assemble biomaterials, cells, and signaling molecules into anatomically relevant functional tissues or organ parts. Scaffold-free fabrication has recently attracted a great deal of interest due to the ability to recapitulate tissue biology by using self-assembly, which mimics the embryonic development process. Despite several attempts, bioprinting of scale-up tissues at clinically-relevant dimensions with closely recapitulated tissue biology and functionality is still a major roadblock. Here, we fabricate and engineer scaffold-free scalable tissue strands as a novel bioink material for robotic-assisted bioprinting technologies. Compare to 400 μm-thick tissue spheroids bioprinted in a liquid delivery medium into confining molds, near 8 cm-long tissue strands with rapid fusion and self-assemble capabilities are bioprinted in solid form for the first time without any need for a scaffold or a mold support or a liquid delivery medium, and facilitated native-like scale-up tissues. The prominent approach has been verified using cartilage strands as building units to bioprint articular cartilage tissue. PMID:27346373

Developing better mouse models to study cisplatin-induced kidney injury.

Science.gov (United States)

Sharp, Cierra N; Siskind, Leah J

2017-10-01

Cisplatin is a potent chemotherapeutic used for the treatment of many types of cancer. However, its dose-limiting side effect is nephrotoxicity leading to acute kidney injury (AKI). Patients who develop AKI have an increased risk of mortality and are more likely to develop chronic kidney disease (CKD). Unfortunately, there are no therapeutic interventions for the treatment of AKI. It has been suggested that the lack of therapies is due in part to the fact that the established mouse model used to study cisplatin-induced AKI does not recapitulate the cisplatin dosing regimen patients receive. In recent years, work has been done to develop more clinically relevant models of cisplatin-induced kidney injury, with much work focusing on incorporation of multiple low doses of cisplatin administered over a period of weeks. These models can be used to recapitulate the development of CKD after AKI and, by doing so, increase the likelihood of identifying novel therapeutic targets for the treatment of cisplatin-induced kidney injury. Copyright © 2017 the American Physiological Society.

Building Your Instrumental Music Program in an Urban School

Science.gov (United States)

Mixon, Kevin

2005-01-01

MENC has recently, recapitulated its vision of "Music for All" in its strategic plan, which warns that "30 to 50 per cent of new teachers who work in urban areas leave the field in their first three years of service.'' This undoubtedly affects instrumental music instruction for urban children. Collegial sharing is one solution to problems…

Cosmopolitan Democracy: A Restatement

Science.gov (United States)

Archibugi, Daniele

2012-01-01

Can democracy be expanded beyond borders? For many years, it was taken for granted that the norms and values of democracy could be applied within the boundaries of a state only. But over the last 20 years, it has been increasingly argued that democracy can also inform international organizations and global politics. This article recapitulates the…

Brain Wiring in the Fourth Dimension.

Science.gov (United States)

Wernet, Mathias F; Desplan, Claude

2015-07-02

In this issue of Cell, Langen et al. use time-lapse multiphoton microscopy to show how Drosophila photoreceptor growth cones find their targets. Based on the observed dynamics, they develop a simple developmental algorithm recapitulating the highly complex connectivity pattern of these neurons, suggesting a basic framework for establishing wiring specificity. Copyright © 2015 Elsevier Inc. All rights reserved.

Microbands and clustered microbands in rolled copper

DEFF Research Database (Denmark)

Leffers, T.; Ananthan, V.S.; Christoffersen, H.

2001-01-01

First we recapitulate the present knowledge about microbands (MB2s). On this basis we suggest that the grains with profuse microbanding may deform with slip on one single slip plane. This suggestion is substantiated by the observation of clustered MB2s. Furthermore we show that the MB2 walls cons...... consist of a loosely knit dislocation network....

The Greenhouse effect: from research to political action

International Nuclear Information System (INIS)

Bernard, A.; Charmant, A.; Ladoux, N.; Vielle, M.

1992-01-01

What would be the ecological and socio-economic consequences of the warming of the planet Earth. The greenhouse effect is better defined today, but evaluating the dangers is still a risky business which demands extreme caution. The study recapitulates the current state of knowledge, and the preventive measures under consideration, so as to encourage the examination of the question

Space Time Quantization and the Big Bang

OpenAIRE

Sidharth, B. G.

1998-01-01

A recent cosmological model is recapitulated which deduces the correct mass, radius and age of the universe as also the Hubble constant and other well known apparently coincidental relations. It also predicts an ever expanding accelerating universe as is confirmed by latest supernovae observations. Finally the Big Bang model is recovered as a suitable limiting case.

AOM/DSS Model of Colitis-Associated Cancer

Science.gov (United States)

Parang, Bobak; Barret, Caitlyn W.; Williams, Christopher S.

2016-01-01

Summary Our understanding of colitis-associated carcinoma (CAC) has benefited substantially from mouse models that faithfully recapitulate human CAC. Chemical models, in particular, have enabled fast and efficient analysis of genetic and environmental modulators of CAC without the added requirement of time-intensive genetic crossings. Here we describe the Azoxymethane (AOM)/Dextran Sodium Sulfate (DSS) mouse model of inflammatory colorectal cancer. PMID:27246042

AOM/DSS Model of Colitis-Associated Cancer.

Science.gov (United States)

Parang, Bobak; Barrett, Caitlyn W; Williams, Christopher S

2016-01-01

Our understanding of colitis-associated carcinoma (CAC) has benefited substantially from mouse models that faithfully recapitulate human CAC. Chemical models, in particular, have enabled fast and efficient analysis of genetic and environmental modulators of CAC without the added requirement of time-intensive genetic crossings. Here we describe the Azoxymethane (AOM)/Dextran Sodium Sulfate (DSS) mouse model of inflammatory colorectal cancer.

Argument z důsledku a jeho varianty (Argument from Consequences and its variants

Directory of Open Access Journals (Sweden)

Martina Juříková

2016-03-01

Full Text Available The article examines the use and evaluation of the argument from consequences, its historical origins since Aristotle through Blaise Pascal, David Hume until the inclusion of this argument into the textbooks of modern logic. The article also recapitulates current evaluation of this argument by Douglas Walton and along with Walton presents its two variants and criteria for evaluating their validity.

Chance, destiny, and the inner workings of ClpXP.

Science.gov (United States)

Russell, Rick; Matouschek, Andreas

2014-07-31

AAA+ proteases are responsible for protein degradation in all branches of life. Using single-molecule and ensemble assays, Cordova et al. investigate how the bacterial protease ClpXP steps through a substrate's polypeptide chain and construct a quantitative kinetic model that recapitulates the interplay between stochastic and deterministic behaviors of ClpXP. Copyright © 2014 Elsevier Inc. All rights reserved.

Robust Praxialism and the Anti-Aesthetic Turn

Science.gov (United States)

Alperson, Philip

2010-01-01

In this paper I retrace the line of thought that led me to the position of a praxial philosophy of music education, from a perspective 20 years after the inaugural meeting of the International Society for the Philosophy of Music Education. I discuss how I conceive of the general project of the philosophy of music education and recapitulate some of…

Org-1 is required for the diversification of circular visceral muscle founder cells and normal midgut morphogenesis.

Science.gov (United States)

Schaub, Christoph; Frasch, Manfred

2013-04-15

The T-Box family of transcription factors plays fundamental roles in the generation of appropriate spatial and temporal gene expression profiles during cellular differentiation and organogenesis in animals. In this study we report that the Drosophila Tbx1 orthologue optomotor-blind-related-gene-1 (org-1) exerts a pivotal function in the diversification of circular visceral muscle founder cell identities in Drosophila. In embryos mutant for org-1, the specification of the midgut musculature per se is not affected, but the differentiating midgut fails to form the anterior and central midgut constrictions and lacks the gastric caeca. We demonstrate that this phenotype results from the nearly complete loss of the founder cell specific expression domains of several genes known to regulate midgut morphogenesis, including odd-paired (opa), teashirt (tsh), Ultrabithorax (Ubx), decapentaplegic (dpp) and wingless (wg). To address the mechanisms that mediate the regulatory inputs from org-1 towards Ubx, dpp, and wg in these founder cells we genetically dissected known visceral mesoderm specific cis-regulatory-modules (CRMs) of these genes. The analyses revealed that the activities of the dpp and wg CRMs depend on org-1, the CRMs are bound by Org-1 in vivo and their T-Box binding sites are essential for their activation in the visceral muscle founder cells. We conclude that Org-1 acts within a well-defined signaling and transcriptional network of the trunk visceral mesoderm as a crucial founder cell-specific competence factor, in concert with the general visceral mesodermal factor Biniou. As such, it directly regulates several key genes involved in the establishment of morphogenetic centers along the anteroposterior axis of the visceral mesoderm, which subsequently organize the formation of midgut constrictions and gastric caeca and thereby determine the morphology of the midgut. Copyright © 2013 Elsevier Inc. All rights reserved.

Hox gene expression leads to differential hind leg development between honeybee castes.

Science.gov (United States)

Bomtorin, Ana Durvalina; Barchuk, Angel Roberto; Moda, Livia Maria; Simoes, Zila Luz Paulino

2012-01-01

Beyond the physiological and behavioural, differences in appendage morphology between the workers and queens of Apis mellifera are pre-eminent. The hind legs of workers, which are highly specialized pollinators, deserve special attention. The hind tibia of worker has an expanded bristle-free region used for carrying pollen and propolis, the corbicula. In queens this structure is absent. Although the morphological differences are well characterized, the genetic inputs driving the development of this alternative morphology remain unknown. Leg phenotype determination takes place between the fourth and fifth larval instar and herein we show that the morphogenesis is completed at brown-eyed pupa. Using results from the hybridization of whole genome-based oligonucleotide arrays with RNA samples from hind leg imaginal discs of pre-pupal honeybees of both castes we present a list of 200 differentially expressed genes. Notably, there are castes preferentially expressed cuticular protein genes and members of the P450 family. We also provide results of qPCR analyses determining the developmental transcription profiles of eight selected genes, including abdominal-A, distal-less and ultrabithorax (Ubx), whose roles in leg development have been previously demonstrated in other insect models. Ubx expression in workers hind leg is approximately 25 times higher than in queens. Finally, immunohistochemistry assays show that Ubx localization during hind leg development resembles the bristles localization in the tibia/basitarsus of the adult legs in both castes. Our data strongly indicate that the development of the hind legs diphenism characteristic of this corbiculate species is driven by a set of caste-preferentially expressed genes, such as those encoding cuticular protein genes, P450 and Hox proteins, in response to the naturally different diets offered to honeybees during the larval period.

Fenton reaction induced cancer in wild type rats recapitulates genomic alterations observed in human cancer.

Directory of Open Access Journals (Sweden)

Shinya Akatsuka

Full Text Available Iron overload has been associated with carcinogenesis in humans. Intraperitoneal administration of ferric nitrilotriacetate initiates a Fenton reaction in renal proximal tubules of rodents that ultimately leads to a high incidence of renal cell carcinoma (RCC after repeated treatments. We performed high-resolution microarray comparative genomic hybridization to identify characteristics in the genomic profiles of this oxidative stress-induced rat RCCs. The results revealed extensive large-scale genomic alterations with a preference for deletions. Deletions and amplifications were numerous and sometimes fragmented, demonstrating that a Fenton reaction is a cause of such genomic alterations in vivo. Frequency plotting indicated that two of the most commonly altered loci corresponded to a Cdkn2a/2b deletion and a Met amplification. Tumor sizes were proportionally associated with Met expression and/or amplification, and clustering analysis confirmed our results. Furthermore, we developed a procedure to compare whole genomic patterns of the copy number alterations among different species based on chromosomal syntenic relationship. Patterns of the rat RCCs showed the strongest similarity to the human RCCs among five types of human cancers, followed by human malignant mesothelioma, an iron overload-associated cancer. Therefore, an iron-dependent Fenton chemical reaction causes large-scale genomic alterations during carcinogenesis, which may result in distinct genomic profiles. Based on the characteristics of extensive genome alterations in human cancer, our results suggest that this chemical reaction may play a major role during human carcinogenesis.

Clonal selection in xenografted TAM recapitulates the evolutionary process of myeloid leukemia in Down syndrome.

Science.gov (United States)

Saida, Satoshi; Watanabe, Ken-ichiro; Sato-Otsubo, Aiko; Terui, Kiminori; Yoshida, Kenichi; Okuno, Yusuke; Toki, Tsutomu; Wang, RuNan; Shiraishi, Yuichi; Miyano, Satoru; Kato, Itaru; Morishima, Tatsuya; Fujino, Hisanori; Umeda, Katsutsugu; Hiramatsu, Hidefumi; Adachi, Souichi; Ito, Etsuro; Ogawa, Seishi; Ito, Mamoru; Nakahata, Tatsutoshi; Heike, Toshio

2013-05-23

Transient abnormal myelopoiesis (TAM) is a clonal preleukemic disorder that progresses to myeloid leukemia of Down syndrome (ML-DS) through the accumulation of genetic alterations. To investigate the mechanism of leukemogenesis in this disorder, a xenograft model of TAM was established using NOD/Shi-scid, interleukin (IL)-2Rγ(null) mice. Serial engraftment after transplantation of cells from a TAM patient who developed ML-DS a year later demonstrated their self-renewal capacity. A GATA1 mutation and no copy number alterations (CNAs) were detected in the primary patient sample by conventional genomic sequencing and CNA profiling. However, in serial transplantations, engrafted TAM-derived cells showed the emergence of divergent subclones with another GATA1 mutation and various CNAs, including a 16q deletion and 1q gain, which are clinically associated with ML-DS. Detailed genomic analysis identified minor subclones with a 16q deletion or this distinct GATA1 mutation in the primary patient sample. These results suggest that genetically heterogeneous subclones with varying leukemia-initiating potential already exist in the neonatal TAM phase, and ML-DS may develop from a pool of such minor clones through clonal selection. Our xenograft model of TAM may provide unique insight into the evolutionary process of leukemia.

klf2ash317 Mutant Zebrafish Do Not Recapitulate Morpholino-Induced Vascular and Haematopoietic Phenotypes.

Directory of Open Access Journals (Sweden)

Peter Novodvorsky

Full Text Available The zinc-finger transcription factor Krϋppel-like factor 2 (KLF2 transduces blood flow into molecular signals responsible for a wide range of responses within the vasculature. KLF2 maintains a healthy, quiescent endothelial phenotype. Previous studies report a range of phenotypes following morpholino antisense oligonucleotide-induced klf2a knockdown in zebrafish. Targeted genome editing is an increasingly applied method for functional assessment of candidate genes. We therefore generated a stable klf2a mutant zebrafish and characterised its cardiovascular and haematopoietic development.Using Transcription Activator-Like Effector Nucleases (TALEN we generated a klf2a mutant (klf2ash317 with a 14bp deletion leading to a premature stop codon in exon 2. Western blotting confirmed loss of wild type Klf2a protein and the presence of a truncated protein in klf2ash317 mutants. Homozygous klf2ash317 mutants exhibit no defects in vascular patterning, survive to adulthood and are fertile, without displaying previously described morphant phenotypes such as high-output cardiac failure, reduced haematopoetic stem cell (HSC development or impaired formation of the 5th accessory aortic arch. Homozygous klf2ash317 mutation did not reduce angiogenesis in zebrafish with homozygous mutations in von Hippel Lindau (vhl, a form of angiogenesis that is dependent on blood flow. We examined expression of three klf family members in wildtype and klf2ash317 zebrafish. We detected vascular expression of klf2b (but not klf4a or biklf/klf4b/klf17 in wildtypes but found no differences in expression that might account for the lack of phenotype in klf2ash317 mutants. klf2b morpholino knockdown did not affect heart rate or impair formation of the 5th accessory aortic arch in either wildtypes or klf2ash317 mutants.The klf2ash317 mutation produces a truncated Klf2a protein but, unlike morpholino induced klf2a knockdown, does not affect cardiovascular development.

Tissue-Mimicking Geometrical Constraints Stimulate Tissue-Like Constitution and Activity of Mouse Neonatal and Human-Induced Pluripotent Stem Cell-Derived Cardiac Myocytes

Directory of Open Access Journals (Sweden)

Götz Pilarczyk

2016-01-01

Full Text Available The present work addresses the question of to what extent a geometrical support acts as a physiological determining template in the setup of artificial cardiac tissue. Surface patterns with alternating concave to convex transitions of cell size dimensions were used to organize and orientate human-induced pluripotent stem cell (hIPSC-derived cardiac myocytes and mouse neonatal cardiac myocytes. The shape of the cells, as well as the organization of the contractile apparatus recapitulates the anisotropic line pattern geometry being derived from tissue geometry motives. The intracellular organization of the contractile apparatus and the cell coupling via gap junctions of cell assemblies growing in a random or organized pattern were examined. Cell spatial and temporal coordinated excitation and contraction has been compared on plain and patterned substrates. While the α-actinin cytoskeletal organization is comparable to terminally-developed native ventricular tissue, connexin-43 expression does not recapitulate gap junction distribution of heart muscle tissue. However, coordinated contractions could be observed. The results of tissue-like cell ensemble organization open new insights into geometry-dependent cell organization, the cultivation of artificial heart tissue from stem cells and the anisotropy-dependent activity of therapeutic compounds.

Disease Modeling Using 3D Organoids Derived from Human Induced Pluripotent Stem Cells.

Science.gov (United States)

Ho, Beatrice Xuan; Pek, Nicole Min Qian; Soh, Boon-Seng

2018-03-21

The rising interest in human induced pluripotent stem cell (hiPSC)-derived organoid culture has stemmed from the manipulation of various combinations of directed multi-lineage differentiation and morphogenetic processes that mimic organogenesis. Organoids are three-dimensional (3D) structures that are comprised of multiple cell types, self-organized to recapitulate embryonic and tissue development in vitro. This model has been shown to be superior to conventional two-dimensional (2D) cell culture methods in mirroring functionality, architecture, and geometric features of tissues seen in vivo. This review serves to highlight recent advances in the 3D organoid technology for use in modeling complex hereditary diseases, cancer, host-microbe interactions, and possible use in translational and personalized medicine where organoid cultures were used to uncover diagnostic biomarkers for early disease detection via high throughput pharmaceutical screening. In addition, this review also aims to discuss the advantages and shortcomings of utilizing organoids in disease modeling. In summary, studying human diseases using hiPSC-derived organoids may better illustrate the processes involved due to similarities in the architecture and microenvironment present in an organoid, which also allows drug responses to be properly recapitulated in vitro.

Truncated C-terminus of fibrillin-1 induces Marfanoid-progeroid-lipodystrophy (MPL) syndrome in rabbit.

Science.gov (United States)

Chen, Mao; Yao, Bing; Yang, Qiangbing; Deng, Jichao; Song, Yuning; Sui, Tingting; Zhou, Lina; Yao, HaoBing; Xu, Yuanyuan; Ouyang, Hongsheng; Pang, Daxin; Li, Zhanjun; Lai, Liangxue

2018-04-09

Various clinical differences have been observed between patients with the FBN1 gene mutation and those with the classical Marfan phenotype. Although FBN1 knockout (KO) or dominant-negative mutant mice are widely used as an animal model for Marfan syndrome (MFS), these mice cannot recapitulate the genotype/phenotype relationship of Marfanoid-progeroid-lipodystrophy (MPL) syndrome, which is caused by a mutation in the C-terminus of fibrillin-1, the penultimate exon of the FBN1 gene. Here, we describe the generation of a rabbit MPL model with C-terminal truncation of fibrillin-1 using a CRISPR/Cas9 system. FBN1 heterozygous ( FBN1 Het) rabbits faithfully recapitulated the phenotypes of MFS, including muscle wasting and impaired connective tissue, ocular syndrome and aortic dilation. Moreover, skin symptoms, lipodystrophy, growth retardation and dysglycemia were also seen in these FBN1 Het rabbits, and have not been reported in other animal models. In conclusion, this novel rabbit model mimics the histopathological changes and functional defects of MPL syndrome, and could become a valuable model for studies of pathogenesis and drug screening for MPL syndrome. © 2018. Published by The Company of Biologists Ltd.

Small Animal Models for Evaluating Filovirus Countermeasures.

Science.gov (United States)

Banadyga, Logan; Wong, Gary; Qiu, Xiangguo

2018-05-11

The development of novel therapeutics and vaccines to treat or prevent disease caused by filoviruses, such as Ebola and Marburg viruses, depends on the availability of animal models that faithfully recapitulate clinical hallmarks of disease as it is observed in humans. In particular, small animal models (such as mice and guinea pigs) are historically and frequently used for the primary evaluation of antiviral countermeasures, prior to testing in nonhuman primates, which represent the gold-standard filovirus animal model. In the past several years, however, the filovirus field has witnessed the continued refinement of the mouse and guinea pig models of disease, as well as the introduction of the hamster and ferret models. We now have small animal models for most human-pathogenic filoviruses, many of which are susceptible to wild type virus and demonstrate key features of disease, including robust virus replication, coagulopathy, and immune system dysfunction. Although none of these small animal model systems perfectly recapitulates Ebola virus disease or Marburg virus disease on its own, collectively they offer a nearly complete set of tools in which to carry out the preclinical development of novel antiviral drugs.

Distinct molecular subtypes of uterine leiomyosarcoma respond differently to chemotherapy treatment.

Science.gov (United States)

An, Yang; Wang, Shuzhen; Li, Songlin; Zhang, Lulu; Wang, Dayong; Wang, Haojie; Zhu, Shibai; Zhu, Wan; Li, Yongqiang; Chen, Wenwu; Ji, Shaoping; Guo, Xiangqian

2017-09-11

Uterine leiomyosarcoma (ULMS) is an aggressive form of soft tissue tumors. The molecular heterogeneity and pathogenesis of ULMS are not well understood. Expression profiling data were used to determine the possibility and optimal number of ULMS molecular subtypes. Next, clinicopathological characters and molecular pathways were analyzed in each subtype to prospect the clinical applications and progression mechanisms of ULMS. Two distinct molecular subtypes of ULMS were defined based on different gene expression signatures. Subtype I ULMS recapitulated low-grade ULMS, the gene expression pattern of which resembled normal smooth muscle cells, characterized by overexpression of smooth muscle function genes such as LMOD1, SLMAP, MYLK, MYH11. In contrast, subtype II ULMS recapitulated high-grade ULMS with higher tumor weight and invasion rate, and was characterized by overexpression of genes involved in the pathway of epithelial to mesenchymal transition and tumorigenesis, such as CDK6, MAPK13 and HOXA1. We identified two distinct molecular subtypes of ULMS responding differently to chemotherapy treatment. Our findings provide a better understanding of ULMS intrinsic molecular subtypes, and will potentially facilitate the development of subtype-specific diagnosis biomarkers and therapy strategies for these tumors.

Delivery 7 Report on the impact of conflicts/synergies and policy proposals for implementing the EU Action Plan in member states

DEFF Research Database (Denmark)

Beck, Anne-Marie Tyroll; Michelsen, Johannes

This report on “Implementing the European Organic Action Plan in EU member states - stakeholders’ perceptions of implementation problems and coping strategies” recapitulates the results of a series of national workshops undertaken in winter/spring 2007. It brings together very different views...... and perceptions on organic action plans and possible evaluation methodologies and can be seen as ORGAP’s stakeholder oriented or public oriented step....

Remote Access: A Vision for Mobile Medical Devices

Directory of Open Access Journals (Sweden)

Herbert Ernst

2005-11-01

Full Text Available During the Symposium for Remote Engineering and Virtual Instrumentation held at Brasov in early July 2005 an outlook was presented regarding the future potential of remote engineering for mobile medical devices. It is the intention of this article to recapitulate the content of the initiated discussions and to stimulate work in this complex and until now largely neglected field of application.

3D-Printed ABS and PLA Scaffolds for Cartilage and Nucleus Pulposus Tissue Regeneration

OpenAIRE

Rosenzweig, Derek H.; Carelli, Eric; Steffen, Thomas; Jarzem, Peter; Haglund, Lisbet

2015-01-01

Painful degeneration of soft tissues accounts for high socioeconomic costs. Tissue engineering aims to provide biomimetics recapitulating native tissues. Biocompatible thermoplastics for 3D printing can generate high-resolution structures resembling tissue extracellular matrix. Large-pore 3D-printed acrylonitrile butadiene styrene (ABS) and polylactic acid (PLA) scaffolds were compared for cell ingrowth, viability, and tissue generation. Primary articular chondrocytes and nucleus pulposus (N...

Microgel Mechanics in Biomaterial Design

OpenAIRE

Saxena, Shalini; Hansen, Caroline E.; Lyon, L. Andrew

2014-01-01

Conspectus The field of polymeric biomaterials has received much attention in recent years due to its potential for enhancing the biocompatibility of systems and devices applied to drug delivery and tissue engineering. Such applications continually push the definition of biocompatibility from relatively straightforward issues such as cytotoxicity to significantly more complex processes such as reducing foreign body responses or even promoting/recapitulating natural body functions. Hydrogels a...

Stress Effects on Multiple Memory System Interactions

OpenAIRE

Ness, Deborah; Calabrese, Pasquale

2016-01-01

Extensive behavioural, pharmacological, and neurological research reports stress effects on mammalian memory processes. While stress effects on memory quantity have been known for decades, the influence of stress on multiple memory systems and their distinct contributions to the learning process have only recently been described. In this paper, after summarizing the fundamental biological aspects of stress/emotional arousal and recapitulating functionally and anatomically distinct memory syst...

Brief Communication: Tissue-engineered Microenvironment Systems for Modeling Human Vasculature

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Tourovskaia, Anna; Fauver, Mark; Kramer, Gregory; Simonson, Sara; Neumann, Thomas

2015-01-01

The high attrition rate of drug candidates late in the development process has led to an increasing demand for test assays that predict clinical outcome better than conventional 2D cell culture systems and animal models. Government agencies, the military, and the pharmaceutical industry have started initiatives for the development of novel in-vitro systems that recapitulate functional units of human tissues and organs. There is growing evidence that 3D cell arrangement, co-culture of different cell types, and physico-chemical cues lead to improved predictive power. A key element of all tissue microenvironments is the vasculature. Beyond transporting blood the microvasculature assumes important organ-specific functions. It is also involved in pathologic conditions, such as inflammation, tumor growth, metastasis, and degenerative diseases. To provide a tool for modeling this important feature of human tissue microenvironments, we developed a microfluidic chip for creating tissue-engineered microenvironment systems (TEMS) composed of tubular cell structures. Our chip design encompasses a small chamber that is filled with an extracellular matrix (ECM) surrounding one or more tubular channels. Endothelial cells seeded into the channels adhere to the ECM walls and grow into perfusable tubular tissue structures that are fluidically connected to upstream and downstream fluid channels in the chip. Using these chips we created models of angiogenesis, the blood-brain-barrier (BBB), and tumor-cell extravasation. Our angiogenesis model recapitulates true angiogenesis, in which sprouting occurs from a “parent” vessel in response to a gradient of growth factors. Our BBB model is composed of a microvessel generated from brain-specific endothelial cells (ECs) within an ECM populated with astrocytes and pericytes. Our tumor-cell extravasation model can be utilized to visualize and measure tumor-cell migration through vessel walls into the surrounding matrix. The described

Many reasons or just one : How response mode affects reasoning in the conjunction problem

OpenAIRE

Hertwig, R.; Chase, V.

1998-01-01

Forty years of experimentation on class inclusion and its probabilistic relatives have led to inconsistent results and conclusions about human reasoning. Recent research on the conjunction "fallacy" recapitulates this history. In contrast to previous results, we found that a majority of participants adhere to class inclusion in the classic Linda problem. We outline a theoretical framework that attributes the contradictory results to differences in statistical sophistication and to differences...

The paradox of Foxd3: how does it function in pluripotency and differentiation of embryonic stem cells?

OpenAIRE

Plank-Bazinet, Jennifer L.; Mundell, Nathan A.

2016-01-01

Uncommitted cells of the early mammalian embryo transition through distinct stages of pluripotency, including establishment of ground state “naïve” pluripotency in the early epiblast, transition to a post-implantation “primed” state, and subsequent lineage commitment of the gastrulating epiblast. Previous transcriptional profiling of in vitro models to recapitulate early to late epiblast transition and differentiation suggest that distinct gene regulatory networks are likely to function in ea...

Organoids as Models for Neoplastic Transformation | Office of Cancer Genomics

Science.gov (United States)

Cancer models strive to recapitulate the incredible diversity inherent in human tumors. A key challenge in accurate tumor modeling lies in capturing the panoply of homo- and heterotypic cellular interactions within the context of a three-dimensional tissue microenvironment. To address this challenge, researchers have developed organotypic cancer models (organoids) that combine the 3D architecture of in vivo tissues with the experimental facility of 2D cell lines.

C. elegans model of neuronal aging

OpenAIRE

Peng, Chiu-Ying; Chen, Chun-Hao; Hsu, Jiun-Min; Pan, Chun-Liang

2011-01-01

Aging of the nervous system underlies the behavioral and cognitive decline associated with senescence. Understanding the molecular and cellular basis of neuronal aging will therefore contribute to the development of effective treatments for aging and age-associated neurodegenerative disorders. Despite this pressing need, there are surprisingly few animal models that aim at recapitulating neuronal aging in a physiological context. We recently developed a C. elegans model of neuronal aging, and...

Determination of {alpha}{sub s} from Gross-Llewellyn Smith sum rule by accounting for infrared renormalon

Energy Technology Data Exchange (ETDEWEB)

Contreras, C [Department of Physics, Universidad Tecn. Federico Santa Maria, Valparaiso (Chile); Cvetic, G [Department of Physics, Universidad Tecn. Federico Santa Maria, Valparaiso (Chile); Jeong, K S [Department of Physics, Korea Advanced Institute of Science and Technology, Daejon (Korea, Republic of); Lee, Taekoon [Department of Physics, Korea Advanced Institute of Science and Technology, Daejon (Korea, Republic of)

2003-08-01

We recapitulate the method which resums the truncated perturbation series of a physical observable in a way which takes into account the structure of the leading infrared renormalon. We apply the method to the Gross-Llewellyn Smith (GLS) sum rule. By confronting the obtained result with the experimentally extracted GLS value, we determine the value of the QCD coupling parameter, which turns out to agree with the present world average.

Characterization and pathogenesis of aerosolized eastern equine encephalitis in the common marmoset (Callithrix jacchus)

OpenAIRE

Porter, Aimee I.; Erwin-Cohen, Rebecca A.; Twenhafel, Nancy; Chance, Taylor; Yee, Steven B.; Kern, Steven J.; Norwood, David; Hartman, Laurie J.; Parker, Michael D.; Glass, Pamela J.; DaSilva, Luis

2017-01-01

Background Licensed antiviral therapeutics and vaccines to protect against eastern equine encephalitis virus (EEEV) in humans currently do not exist. Animal models that faithfully recapitulate the clinical characteristics of human EEEV encephalitic disease, including fever, drowsiness, anorexia, and neurological signs such as seizures, are needed to satisfy requirements of the Food and Drug Administration (FDA) for clinical product licensing under the Animal Rule. Methods In an effort to meet...

Sympatho-adrenal activation by chronic intermittent hypoxia

OpenAIRE

Prabhakar, Nanduri R.; Kumar, Ganesh K.; Peng, Ying-Jie

2012-01-01

Recurrent apnea with chronic intermittent hypoxia (CIH) is a major clinical problem in adult humans and infants born preterm. Patients with recurrent apnea exhibit heightened sympathetic activity as well as elevated plasma catecholamine levels, and these phenotypes are effectively recapitulated in rodent models of CIH. This article summarizes findings from studies addressing sympathetic activation in recurrent apnea patients and rodent models of CIH and the underlying cellular and molecular m...

Searching for superconductors with high critical temperature

Energy Technology Data Exchange (ETDEWEB)

Chao, C

1977-08-18

Critical temperature of superconductors can be and must be raised so that their range of application can be broadened. It was estimated that, in 3 to 5 years, superconductor electric generators might be used in nuclear submarines and/or other applications where the requirements of small volume and light weight are critical. The BCS theory was recapitulated. Possible methods of achieving higher critical temperature were proposed and discussed.

Regenerative Endodontics: Barriers and Strategies for Clinical Translation

OpenAIRE

Kim, Sahng G.; Zhou, Jian; Ye, Ling; Cho, Shoko; Suzuki, Takahiro; Fu, Susan Y.; Yang, Rujing; Zhou, Xuedong; Mao, Jeremy J.

2012-01-01

Despite a great deal of enthusiasm and effort, regenerative endodontics has encountered substantial challenges towards clinical translation. Recent adoption by the American Dental Association (ADA) of evoked pulp bleeding in immature permanent teeth is an important step for regenerative endodontics. However, there is no regenerative therapy for the majority of endodontic diseases. Simple recapitulation of cell therapy and tissue engineering strategies that are under development for other orga...

Kidney branching morphogenesis under the control of a ligand–receptor-based Turing mechanism

International Nuclear Information System (INIS)

Menshykau, Denis; Iber, Dagmar

2013-01-01

The main signalling proteins that control early kidney branching have been defined. Yet the underlying mechanism is still elusive. We have previously shown that a Schnakenberg-type Turing mechanism can recapitulate the branching and protein expression patterns in wild-type and mutant lungs, but it is unclear whether this mechanism would extend to other branched organs that are regulated by other proteins. Here, we show that the glial cell line-derived neurotrophic factor–RET regulatory interaction gives rise to a Schnakenberg-type Turing model that reproduces the observed budding of the ureteric bud from the Wolffian duct, its invasion into the mesenchyme and the observed branching pattern. The model also recapitulates all relevant protein expression patterns in wild-type and mutant mice. The lung and kidney models are both based on a particular receptor–ligand interaction and require (1) cooperative binding of ligand and receptor, (2) a lower diffusion coefficient for the receptor than for the ligand and (3) an increase in the receptor concentration in response to receptor–ligand binding (by enhanced transcription, more recycling or similar). These conditions are met also by other receptor–ligand systems. We propose that ligand–receptor-based Turing patterns represent a general mechanism to control branching morphogenesis and other developmental processes. (paper)

Epstein–Barr virus glycoprotein gM can interact with the cellular protein p32 and knockdown of p32 impairs virus

International Nuclear Information System (INIS)

Changotra, Harish; Turk, Susan M.; Artigues, Antonio; Thakur, Nagendra; Gore, Mindy; Muggeridge, Martin I.; Hutt-Fletcher, Lindsey M.

2016-01-01

The Epstein–Barr virus glycoprotein complex gMgN has been implicated in assembly and release of fully enveloped virus, although the precise role that it plays has not been elucidated. We report here that the long predicted cytoplasmic tail of gM is not required for complex formation and that it interacts with the cellular protein p32, which has been reported to be involved in nuclear egress of human cytomegalovirus and herpes simplex virus. Although redistribution of p32 and colocalization with gM was not observed in virus infected cells, knockdown of p32 expression by siRNA or lentivirus-delivered shRNA recapitulated the phenotype of a virus lacking expression of gNgM. A proportion of virus released from cells sedimented with characteristics of virus lacking an intact envelope and there was an increase in virus trapped in nuclear condensed chromatin. The observations suggest the possibility that p32 may also be involved in nuclear egress of Epstein–Barr virus. - Highlights: • The predicted cytoplasmic tail of gM is not required to complex with gN. • Cellular p32 can interact with the predicted cytoplasmic tail of EBV gM. • Knockdown of p32 recapitulates the phenotype of virus lacking the gNgM complex.

Whole-Body Vibration Mimics the Metabolic Effects of Exercise in Male Leptin Receptor-Deficient Mice.

Science.gov (United States)

McGee-Lawrence, Meghan E; Wenger, Karl H; Misra, Sudipta; Davis, Catherine L; Pollock, Norman K; Elsalanty, Mohammed; Ding, Kehong; Isales, Carlos M; Hamrick, Mark W; Wosiski-Kuhn, Marlena; Arounleut, Phonepasong; Mattson, Mark P; Cutler, Roy G; Yu, Jack C; Stranahan, Alexis M

2017-05-01

Whole-body vibration (WBV) has gained attention as a potential exercise mimetic, but direct comparisons with the metabolic effects of exercise are scarce. To determine whether WBV recapitulates the metabolic and osteogenic effects of physical activity, we exposed male wild-type (WT) and leptin receptor-deficient (db/db) mice to daily treadmill exercise (TE) or WBV for 3 months. Body weights were analyzed and compared with WT and db/db mice that remained sedentary. Glucose and insulin tolerance testing revealed comparable attenuation of hyperglycemia and insulin resistance in db/db mice following TE or WBV. Both interventions reduced body weight in db/db mice and normalized muscle fiber diameter. TE or WBV also attenuated adipocyte hypertrophy in visceral adipose tissue and reduced hepatic lipid content in db/db mice. Although the effects of leptin receptor deficiency on cortical bone structure were not eliminated by either intervention, exercise and WBV increased circulating levels of osteocalcin in db/db mice. In the context of increased serum osteocalcin, the modest effects of TE and WBV on bone geometry, mineralization, and biomechanics may reflect subtle increases in osteoblast activity in multiple areas of the skeleton. Taken together, these observations indicate that WBV recapitulates the effects of exercise on metabolism in type 2 diabetes.

Human Skin Constructs with Spatially Controlled Vasculature Using Primary and iPSC-Derived Endothelial Cells.

Science.gov (United States)

Abaci, Hasan E; Guo, Zongyou; Coffman, Abigail; Gillette, Brian; Lee, Wen-Han; Sia, Samuel K; Christiano, Angela M

2016-07-01

Vascularization of engineered human skin constructs is crucial for recapitulation of systemic drug delivery and for their long-term survival, functionality, and viable engraftment. In this study, the latest microfabrication techniques are used and a novel bioengineering approach is established to micropattern spatially controlled and perfusable vascular networks in 3D human skin equivalents using both primary and induced pluripotent stem cell (iPSC)-derived endothelial cells. Using 3D printing technology makes it possible to control the geometry of the micropatterned vascular networks. It is verified that vascularized human skin equivalents (vHSEs) can form a robust epidermis and establish an endothelial barrier function, which allows for the recapitulation of both topical and systemic delivery of drugs. In addition, the therapeutic potential of vHSEs for cutaneous wounds on immunodeficient mice is examined and it is demonstrated that vHSEs can both promote and guide neovascularization during wound healing. Overall, this innovative bioengineering approach can enable in vitro evaluation of topical and systemic drug delivery as well as improve the potential of engineered skin constructs to be used as a potential therapeutic option for the treatment of cutaneous wounds. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

In Vitro Modeling of Human Germ Cell Development Using Pluripotent Stem Cells

Directory of Open Access Journals (Sweden)

Yuncheng Zhao

2018-02-01

Full Text Available Summary: Due to differences across species, the mechanisms of cell fate decisions determined in mice cannot be readily extrapolated to humans. In this study, we developed a feeder- and xeno-free culture protocol that efficiently induced human pluripotent stem cells (iPSCs into PLZF+/GPR125+/CD90+ spermatogonium-like cells (SLCs. These SLCs were enriched with key genes in germ cell development such as MVH, DAZL, GFRα1, NANOS3, and DMRT1. In addition, a small fraction of SLCs went through meiosis in vitro to develop into haploid cells. We further demonstrated that this chemically defined induction protocol faithfully recapitulated the features of compromised germ cell development of PSCs with NANOS3 deficiency or iPSC lines established from patients with non-obstructive azoospermia. Taken together, we established a powerful experimental platform to investigate human germ cell development and pathology related to male infertility. : In this article, Wang and colleagues established a feeder- and xeno-free system to robustly induce human pluripotent stem cells (PSCs into spermatogonia-like cells. This chemically defined induction protocol faithfully recapitulated the features of compromised germ cell development of PSCs with NANOS3 deficiency or iPSC lines established from patients with non-obstructive azoospermia. Keywords: pluripotent stem cells, spermatogonia, infertility, non-obstructive azoospermia

Epstein–Barr virus glycoprotein gM can interact with the cellular protein p32 and knockdown of p32 impairs virus

Energy Technology Data Exchange (ETDEWEB)

Changotra, Harish; Turk, Susan M. [Department of Microbiology and Immunology, Center for Molecular and Tumor Virology and Feist-Weiller Cancer Center, Louisiana State University Health Sciences Center, Shreveport, LA (United States); Artigues, Antonio [Department of Biochemistry, University of Kansas Medical Center, Kansas City, KS (United States); Thakur, Nagendra; Gore, Mindy; Muggeridge, Martin I. [Department of Microbiology and Immunology, Center for Molecular and Tumor Virology and Feist-Weiller Cancer Center, Louisiana State University Health Sciences Center, Shreveport, LA (United States); Hutt-Fletcher, Lindsey M., E-mail: lhuttf@lsuhsc.edu [Department of Microbiology and Immunology, Center for Molecular and Tumor Virology and Feist-Weiller Cancer Center, Louisiana State University Health Sciences Center, Shreveport, LA (United States)

2016-02-15

The Epstein–Barr virus glycoprotein complex gMgN has been implicated in assembly and release of fully enveloped virus, although the precise role that it plays has not been elucidated. We report here that the long predicted cytoplasmic tail of gM is not required for complex formation and that it interacts with the cellular protein p32, which has been reported to be involved in nuclear egress of human cytomegalovirus and herpes simplex virus. Although redistribution of p32 and colocalization with gM was not observed in virus infected cells, knockdown of p32 expression by siRNA or lentivirus-delivered shRNA recapitulated the phenotype of a virus lacking expression of gNgM. A proportion of virus released from cells sedimented with characteristics of virus lacking an intact envelope and there was an increase in virus trapped in nuclear condensed chromatin. The observations suggest the possibility that p32 may also be involved in nuclear egress of Epstein–Barr virus. - Highlights: • The predicted cytoplasmic tail of gM is not required to complex with gN. • Cellular p32 can interact with the predicted cytoplasmic tail of EBV gM. • Knockdown of p32 recapitulates the phenotype of virus lacking the gNgM complex.

Building an Anisotropic Meniscus with Zonal Variations

Science.gov (United States)

Higashioka, Michael M.; Chen, Justin A.; Hu, Jerry C.

2014-01-01

Toward addressing the difficult problems of knee meniscus regeneration, a self-assembling process has been used to re-create the native morphology and matrix properties. A significant problem in such attempts is the recapitulation of the distinct zones of the meniscus, the inner, more cartilaginous and the outer, more fibrocartilaginous zones. In this study, an anisotropic and zonally variant meniscus was produced by self-assembly of the inner meniscus (100% chondrocytes) followed by cell seeding the outer meniscus (coculture of chondrocytes and meniscus cells). After 4 weeks in culture, the engineered, inner meniscus exhibited a 42% increase in both instantaneous and relaxation moduli and a 62% increase in GAG/DW, as compared to the outer meniscus. In contrast, the circumferential tensile modulus and collagen/DW of the outer zone was 101% and 129% higher, respectively, than the values measured for the inner zone. Furthermore, there was no difference in the radial tensile modulus between the control and zonal engineered menisci, suggesting that the inner and outer zones of the engineered zonal menisci successfully integrated. These data demonstrate that not only can biomechanical and biochemical properties be engineered to differ by the zone, but they can also recapitulate the anisotropic behavior of the knee meniscus. PMID:23931258

Adenovirus Protein E4-ORF1 Activation of PI3 Kinase Reveals Differential Regulation of Downstream Effector Pathways in Adipocytes.

Science.gov (United States)

Chaudhary, Natasha; Gonzalez, Eva; Chang, Sung-Hee; Geng, Fuqiang; Rafii, Shahin; Altorki, Nasser K; McGraw, Timothy E

2016-12-20

Insulin activation of phosphatidylinositol 3-kinase (PI3K) regulates metabolism, including the translocation of the Glut4 glucose transporter to the plasma membrane and inactivation of the FoxO1 transcription factor. Adenoviral protein E4-ORF1 stimulates cellular glucose metabolism by mimicking growth-factor activation of PI3K. We have used E4-ORF1 as a tool to dissect PI3K-mediated signaling in adipocytes. E4-ORF1 activation of PI3K in adipocytes recapitulates insulin regulation of FoxO1 but not regulation of Glut4. This uncoupling of PI3K effects occurs despite E4-ORF1 activating PI3K and downstream signaling to levels achieved by insulin. Although E4-ORF1 does not fully recapitulate insulin's effects on Glut4, it enhances insulin-stimulated insertion of Glut4-containing vesicles to the plasma membrane independent of Rab10, a key regulator of Glut4 trafficking. E4-ORF1 also stimulates plasma membrane translocation of ubiquitously expressed Glut1 glucose transporter, an effect that is likely essential for E4-ORF1 to promote an anabolic metabolism in a broad range of cell types. Copyright © 2016 The Author(s). Published by Elsevier Inc. All rights reserved.

Adenovirus Protein E4-ORF1 Activation of PI3 Kinase Reveals Differential Regulation of Downstream Effector Pathways in Adipocytes

Directory of Open Access Journals (Sweden)

Natasha Chaudhary

2016-12-01

Full Text Available Insulin activation of phosphatidylinositol 3-kinase (PI3K regulates metabolism, including the translocation of the Glut4 glucose transporter to the plasma membrane and inactivation of the FoxO1 transcription factor. Adenoviral protein E4-ORF1 stimulates cellular glucose metabolism by mimicking growth-factor activation of PI3K. We have used E4-ORF1 as a tool to dissect PI3K-mediated signaling in adipocytes. E4-ORF1 activation of PI3K in adipocytes recapitulates insulin regulation of FoxO1 but not regulation of Glut4. This uncoupling of PI3K effects occurs despite E4-ORF1 activating PI3K and downstream signaling to levels achieved by insulin. Although E4-ORF1 does not fully recapitulate insulin’s effects on Glut4, it enhances insulin-stimulated insertion of Glut4-containing vesicles to the plasma membrane independent of Rab10, a key regulator of Glut4 trafficking. E4-ORF1 also stimulates plasma membrane translocation of ubiquitously expressed Glut1 glucose transporter, an effect that is likely essential for E4-ORF1 to promote an anabolic metabolism in a broad range of cell types.

Medullary Thymic Epithelial Cells and Central Tolerance in Autoimmune Hepatitis Development: Novel Perspective from a New Mouse Model

Directory of Open Access Journals (Sweden)

Konstantina Alexandropoulos

2015-01-01

Full Text Available Autoimmune hepatitis (AIH is an immune-mediated disorder that affects the liver parenchyma. Diagnosis usually occurs at the later stages of the disease, complicating efforts towards understanding the causes of disease development. While animal models are useful for studying the etiology of autoimmune disorders, most of the existing animal models of AIH do not recapitulate the chronic course of the human condition. In addition, approaches to mimic AIH-associated liver inflammation have instead led to liver tolerance, consistent with the high tolerogenic capacity of the liver. Recently, we described a new mouse model that exhibited spontaneous and chronic liver inflammation that recapitulated the known histopathological and immunological parameters of AIH. The approach involved liver-extrinsic genetic engineering that interfered with the induction of T-cell tolerance in the thymus, the very process thought to inhibit AIH induction by liver-specific expression of exogenous antigens. The mutation led to depletion of specialized thymic epithelial cells that present self-antigens and eliminate autoreactive T-cells before they exit the thymus. Based on our findings, which are summarized below, we believe that this mouse model represents a relevant experimental tool towards elucidating the cellular and molecular aspects of AIH development and developing novel therapeutic strategies for treating this disease.

Translational control of TWIST1 expression in MCF-10A cell lines recapitulating breast cancer progression

DEFF Research Database (Denmark)

Nairismägi, Maarja-Liisa; Vislovukh, Andrii; Meng, Q

2012-01-01

and EMT, we found TWIST1 to be upregulated during EMT and downregulated early in carcinogenesis. The TWIST1 3′UTR contains putative regulatory elements, including miRNA target sites and two cytoplasmic polyadenylation elements (CPE). We found that miR-580, CPEB1, and CPEB2 act as negative regulators...

L1-mediated retrotransposition of murine B1 and B2 SINEs recapitulated in cultured cells.

Science.gov (United States)

Dewannieux, Marie; Heidmann, Thierry

2005-06-03

SINEs are short interspersed nucleotide elements with transpositional activity, present at a high copy number (up to a million) in mammalian genomes. They are 80-400 bp long, non-coding sequences which derive either from the 7SL RNA (e.g. human Alus, murine B1s) or tRNA (e.g. murine B2s) polymerase III-driven genes. We have previously demonstrated that Alus very efficiently divert the enzymatic machinery of the autonomous L1 LINE (long interspersed nucleotide element) retrotransposons to transpose at a high rate. Here we show, using an ex vivo assay for transposition, that both B1 and B2 SINEs can be mobilized by murine LINEs, with the hallmarks of a bona fide retrotransposition process, including target site duplications of varying lengths and integrations into A-rich sequences. Despite different phylogenetic origins, transposition of the tRNA-derived B2 sequences is as efficient as that of the human Alus, whereas that of B1s is 20-100-fold lower despite a similar high copy number of these elements in the mouse genome. We provide evidence, via an appropriate nucleotide substitution within the B1 sequence in a domain essential for its intracellular targeting, that the current B1 SINEs are not optimal for transposition, a feature most probably selected for the host sake in the course of evolution.

Neuropsychology and cognitive neuroscience in the fMRI era: A recapitulation of localizationist and connectionist views.

Science.gov (United States)

Sutterer, Matthew J; Tranel, Daniel

2017-11-01

We highlight the past 25 years of cognitive neuroscience and neuropsychology, focusing on the impact to the field of the introduction in 1992 of functional MRI (fMRI). We reviewed the past 25 years of literature in cognitive neuroscience and neuropsychology, focusing on the relation and interplay of fMRI studies and studies utilizing the "lesion method" in human participants with focal brain damage. Our review highlights the state of localist/connectionist research debates in cognitive neuroscience and neuropsychology circa 1992, and details how the introduction of fMRI into the field at that time catalyzed a new wave of efforts to map complex human behavior to specific brain regions. This, in turn, eventually evolved into many studies that focused on networks and connections between brain areas, culminating in recent years with large-scale investigations such as the Human Connectome Project. We argue that throughout the past 25 years, neuropsychology-and more precisely, the "lesion method" in humans-has continued to play a critical role in arbitrating conclusions and theories derived from inferred patterns of local brain activity or wide-spread connectivity from functional imaging approaches. We conclude by highlighting the future for neuropsychology in the context of an increasingly complex methodological armamentarium. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Bioactive poly(ethylene glycol) hydrogels to recapitulate the HSC niche and facilitate HSC expansion in culture.

Science.gov (United States)

Cuchiara, Maude L; Coşkun, Süleyman; Banda, Omar A; Horter, Kelsey L; Hirschi, Karen K; West, Jennifer L

2016-04-01

Hematopoietic stem cells (HSCs) have been used therapeutically for decades, yet their widespread clinical use is hampered by the inability to expand HSCs successfully in vitro. In culture, HSCs rapidly differentiate and lose their ability to self-renew. We hypothesize that by mimicking aspects of the bone marrow microenvironment in vitro we can better control the expansion and differentiation of these cells. In this work, derivatives of poly(ethylene glycol) diacrylate hydrogels were used as a culture substrate for hematopoietic stem and progenitor cell (HSPC) populations. Key HSC cytokines, stem cell factor (SCF) and interferon-γ (IFNγ), as well as the cell adhesion ligands RGDS and connecting segment 1 were covalently immobilized onto the surface of the hydrogels. With the use of SCF and IFNγ, we observed significant expansion of HSPCs, ∼97 and ∼104 fold respectively, while maintaining c-kit(+) lin(-) and c-kit(+) Sca1(+) lin(-) (KSL) populations and the ability to form multilineage colonies after 14 days. HSPCs were also encapsulated within degradable poly(ethylene glycol) hydrogels for three-dimensional culture. After expansion in hydrogels, ∼60% of cells were c-kit(+), demonstrating no loss in the proportion of these cells over the 14 day culture period, and ∼50% of colonies formed were multilineage, indicating that the cells retained their differentiation potential. The ability to tailor and use this system to support HSC growth could have implications on the future use of HSCs and other blood cell types in a clinical setting. © 2015 Wiley Periodicals, Inc.

Low dose rectal inoculation of rhesus macaques by SIV smE660 or SIVmac251 recapitulates

Energy Technology Data Exchange (ETDEWEB)

Hraber, Peter [Los Alamos National Laboratory; Giorgi, Elena E [Los Alamos National Laboratory; Keele, Brandon [UNIV OF ALABAMA; Li, Hui [UNIV OF ALABAMA; Learn, Gerald [UNIV OF ALABAMA

2008-01-01

We recently developed a novel strategy to identify transmitted HIV-1 genomes in acutely infected humans using single-genome amplification and a model of random virus evolution. Here, we used this approach to determine the molecular features of simian immunodeficiency virus (SIV) transmission in 18 experimentally infected Indian rhesus macaques. Animals were inoculated intrarectally (i.r.) or intravenously (i.v.) with stocks of SIVmac251 or SIVsmE660 that exhibited sequence diversity typical of early-chronic HIV-1 infection. 987 full-length SIV env sequences (median of 48 per animal) were determined from plasma virion RNA 1--5 wk after infection. i.r. inoculation was followed by productive infection by one or a few viruses (median 1; range 1--5) that diversified randomly with near starlike phylogeny and a Poisson distribution of mutations. Consensus viral sequences from ramp-up and peak viremia were identical to viruses found in the inocula or differed from them by only one or a few nucleotides, providing direct evidence that early plasma viral sequences coalesce to transmitted/founder viruses. i.v. infection was >2,000-fold more efficient than i.r. infection, and viruses transmitted by either route represented the full genetic spectra of the inocula. These findings identify key similarities in mucosal transmission and early diversification between SIV and HIV-1, and thus validate the SIV-macaque mucosal infection model for HIV-1 vaccine and microbicide research.

Online Social Support for Young People: Does It Recapitulate In-person Social Support; Can It Help?

Science.gov (United States)

Cole, David A; Nick, Elizabeth A; Zelkowitz, Rachel L; Roeder, Kathryn M; Spinelli, Tawny

2017-03-01

As social media websites have grown in popularity, public concern about online victimization has grown as well; however, much less attention has focused on the possible beneficial effects of online social networks. If theory and research about in-person social networks pertain, then online social relationships may represent an important modern source of or vehicle for support. In a study of 231 undergraduates, three major findings emerged: (1) for people with weaker in-person social support, social media sites provide a source of social support that is less redundant of the social support they receive in person; (2) in ways that were not redundant of each other, both online and in-person social support were associated with lower levels of depression-related thoughts and feelings, and (3) the beneficial effects of online social support (like in-person social support) offset some of the adverse effects of peer victimization. The study suggests that augmenting social relations via strategic use of social media can enhance young people's social support systems in beneficial ways.

O vývojových tendencích v novočeském vyprávění. Několik poznámek // Several notes to the developmental tendencies in modern Czech narration

Directory of Open Access Journals (Sweden)

Jiří Koten

2016-04-01

Full Text Available The contribution summarizes and recapitulates issues of narrative historical poetics. It deepens knowledge of profile narrative texts (classic and modern and narrative modes (rhetorical, objective and subjective narration with respect to the developmental point of view. In conformity with Doležel’s requirement of the research on narrative transformations in so called longue durée (long duration the contribution observes the processes of subjectivisation and objectivisation of modern Czech narration.

Remodeling of retrotransposon elements during epigenetic induction of adult visual cortical plasticity by HDAC inhibitors

DEFF Research Database (Denmark)

Lennartsson, Andreas; Arner, Erik; Fagiolini, Michela

2015-01-01

BACKGROUND: The capacity for plasticity in the adult brain is limited by the anatomical traces laid down during early postnatal life. Removing certain molecular brakes, such as histone deacetylases (HDACs), has proven to be effective in recapitulating juvenile plasticity in the mature visual cortex...... and reactivate plasticity in the adult cortex. CONCLUSIONS: Treatment with HDAC inhibitors increases accessibility to enhancers and repetitive elements underlying brain-specific gene expression and reactivation of visual cortical plasticity....

Small molecule inhibition of cGAS reduces interferon expression in primary macrophages from autoimmune mice

OpenAIRE

Vincent, Jessica; Adura, Carolina; Gao, Pu; Luz, Antonio; Lama, Lodoe; Asano, Yasutomi; Okamoto, Rei; Imaeda, Toshihiro; Aida, Jumpei; Rothamel, Katherine; Gogakos, Tasos; Steinberg, Joshua; Reasoner, Seth; Aso, Kazuyoshi; Tuschl, Thomas

2017-01-01

Cyclic GMP-AMP synthase is essential for innate immunity against infection and cellular damage, serving as a sensor of DNA from pathogens or mislocalized self-DNA. Upon binding double-stranded DNA, cyclic GMP-AMP synthase synthesizes a cyclic dinucleotide that initiates an inflammatory cellular response. Mouse studies that recapitulate causative mutations in the autoimmune disease Aicardi-Goutières syndrome demonstrate that ablating the cyclic GMP-AMP synthase gene abolishes the deleterious p...

Biochemical and Pharmacological Characterizations of ESI-09 Based EPAC Inhibitors: Defining the ESI-09 “Therapeutic Window”

OpenAIRE

Yingmin Zhu; Haijun Chen; Stephen Boulton; Fang Mei; Na Ye; Giuseppe Melacini; Jia Zhou; Xiaodong Cheng

2015-01-01

The cAMP signaling cascade is one of the most frequently targeted pathways for the development of pharmaceutics. A plethora of recent genetic and pharmacological studies suggest that exchange proteins directly activated by cAMP (EPACs) are implicated in multiple pathologies. Selective EPAC inhibitors have been recently developed. One specific inhibitor, ESI-09, has been shown to block EPAC activity and functions, as well as to recapitulate genetic phenotypes of EPAC knockout mice when applied...

Variants in Nebulin (NEB) Are Linked to the Development of Familial Primary Angle Closure Glaucoma in Basset Hounds

OpenAIRE

Ahram, D.F.; Grozdanic, S.D.; Kecova, H.; Henkes, A.; Collin, R.W.J.; Kuehn, M.H.

2015-01-01

Several dog breeds are susceptible to developing primary angle closure glaucoma (PACG), which suggests a genetic basis for the disease. We have identified a four-generation Basset Hound pedigree with characteristic autosomal recessive PACG that closely recapitulates PACG in humans. Our aim is to utilize gene mapping and whole exome sequencing approaches to identify PACG-causing sequence variants in the Basset. Extensive clinical phenotyping of all pedigree members was conducted. SNP-chip geno...

Glycogen Storage Disease Type Ia in Canines: A Model for Human Metabolic and Genetic Liver Disease

OpenAIRE

Specht, Andrew; Fiske, Laurie; Erger, Kirsten; Cossette, Travis; Verstegen, John; Campbell-Thompson, Martha; Struck, Maggie B.; Lee, Young Mok; Chou, Janice Y.; Byrne, Barry J.; Correia, Catherine E.; Mah, Cathryn S.; Weinstein, David A.; Conlon, Thomas J.

2011-01-01

A canine model of Glycogen storage disease type Ia (GSDIa) is described. Affected dogs are homozygous for a previously described M121I mutation resulting in a deficiency of glucose-6-phosphatase-α. Metabolic, clinicopathologic, pathologic, and clinical manifestations of GSDIa observed in this model are described and compared to those observed in humans. The canine model shows more complete recapitulation of the clinical manifestations seen in humans including “lactic acidosis”, larger size,...

A transgenic Alzheimer rat with plaques, tau pathology, behavioral impairment, oligomeric Aβ and frank neuronal loss

OpenAIRE

Cohen, Robert M.; Rezai-Zadeh, Kavon; Weitz, Tara M.; Rentsendorj, Altan; Gate, David; Spivak, Inna; Bholat, Yasmin; Vasilevko, Vitaly; Glabe, Charles G.; Breunig, Joshua J.; Rakic, Pasko; Davtyan, Hayk; Agadjanyan, Michael G.; Kepe, Vladimir; Barrio, Jorge

2013-01-01

Alzheimer’s disease (AD) is hallmarked by amyloid plaques, neurofibrillary tangles, and widespread cortical neuronal loss (Selkoe, 2001). The ‘amyloid cascade hypothesis’ posits that cerebral amyloid sets neurotoxic events into motion that precipitate Alzheimer dementia (Hardy and Allsop, 1991). Yet, faithful recapitulation of all AD features in widely used transgenic (Tg) mice engineered to overproduce Aβ peptides has been elusive. We have developed a Tg rat model (line TgF344-AD) expressing...

Insight on the energy in the United States; Apercus sur l'energie aux Etats-Unis

Energy Technology Data Exchange (ETDEWEB)

Jamet, Ph

2006-11-15

This document recapitulates the main characteristics and the key data of the energy in the United States (fossil energies, renewable energies, electric power production). The main american strategies are then described as the actions at the international scale during the last five years. The main data of the research programs in the energy domain are presented and the possible consequences of the government change at the Congress are analyzed. (A.L.B.)

BMP4 density gradient in disk-shaped confinement

Science.gov (United States)

Bozorgui, Behnaz; Teimouri, Hamid; Kolomeisky, Anatoly B.

We present a quantitative model that explains the scaling of BMP4 gradients during gastrulation and the recent experimental observation that geometric confinement of human embryonic stem cells is sufficient to recapitulate much of germ layer patterning. Based on a assumption that BMP4 diffusion rate is much smaller than the diffusion rate of it's inhibitor molecules, our results confirm that the length-scale which defines germ layer territories does not depend on system size.

Insight on the energy in the United States

International Nuclear Information System (INIS)

Jamet, Ph.

2006-11-01

This document recapitulates the main characteristics and the key data of the energy in the United States (fossil energies, renewable energies, electric power production). The main american strategies are then described as the actions at the international scale during the last five years. The main data of the research programs in the energy domain are presented and the possible consequences of the government change at the Congress are analyzed. (A.L.B.)

The Role of AR- and VDR-Modulated miRNAs in Sensitization of Prostate Cancer Cells to Therapy

Science.gov (United States)

2012-10-01

13]. Thus, at the time of diagnosis of PCa, he majority of men have declining serum T and low D3 levels, eading to the hypothesis that the two...translatability of PPARA mRNA (Fig. 1), eading to increases in PPARA protein expression, which in turn romotes neutral lipid synthesis and energy storage. This is...surrounding lymph nodes from the primary tumors before establishing bone metastases. This linear temporal relationship is not recapitulated using other

A Cicerone for the Physics of Charm

OpenAIRE

Bianco, S.; Fabbri, F. L.; Benson, D.; Bigi, I.

2003-01-01

After briefly recapitulating the history of the charm quantum number we sketch the experimental environments and instruments employed to study the behaviour of charm hadrons and then describe the theoretical tools for treating charm dynamics. We discuss a wide range of inclusive production processes before analyzing the spectroscopy of hadrons with hidden and open charm and the weak lifetimes of charm mesons and baryons. Then we address leptonic, exclusive semileptonic and nonleptonic charm d...

Key Inflammatory Processes in Human NASH Are Reflected in Ldlr-/-.Leiden Mice: A Translational Gene Profiling Study.

Science.gov (United States)

Morrison, Martine C; Kleemann, Robert; van Koppen, Arianne; Hanemaaijer, Roeland; Verschuren, Lars

2018-01-01

Introduction: It is generally accepted that metabolic inflammation in the liver is an important driver of disease progression in NASH and associated matrix remodeling/fibrosis. However, the exact molecular inflammatory mechanisms are poorly defined in human studies. Investigation of key pathogenic mechanisms requires the use of pre-clinical models, for instance for time-resolved studies. Such models must reflect molecular disease processes of importance in patients. Herein we characterized inflammation in NASH patients on the molecular level by transcriptomics and investigated whether key human disease pathways can be recapitulated experimentally in Ldlr -/- .Leiden mice, an established pre-clinical model of NASH. Methods: Human molecular inflammatory processes were defined using a publicly available NASH gene expression profiling dataset (GSE48452) allowing the comparison of biopsy-confirmed NASH patients with normal controls. Gene profiling data from high-fat diet (HFD)-fed Ldlr -/- .Leiden mice (GSE109345) were used for assessment of the translational value of these mice. Results: In human NASH livers, we observed regulation of 65 canonical pathways of which the majority was involved in inflammation (32%), lipid metabolism (16%), and extracellular matrix/remodeling (12%). A similar distribution of pathways across these categories, inflammation (36%), lipid metabolism (24%) and extracellular matrix/remodeling (8%) was observed in HFD-fed Ldlr -/- .Leiden mice. Detailed evaluation of these pathways revealed that a substantial proportion (11 out of 13) of human NASH inflammatory pathways was recapitulated in Ldlr -/- .Leiden mice. Furthermore, the activation state of identified master regulators of inflammation (i.e., specific transcription factors, cytokines, and growth factors) in human NASH was largely reflected in Ldlr -/- .Leiden mice, further substantiating its translational value. Conclusion: Human NASH is characterized by upregulation of specific

Key Inflammatory Processes in Human NASH Are Reflected in Ldlr−/−.Leiden Mice: A Translational Gene Profiling Study

Science.gov (United States)

Morrison, Martine C.; Kleemann, Robert; van Koppen, Arianne; Hanemaaijer, Roeland; Verschuren, Lars

2018-01-01

Introduction: It is generally accepted that metabolic inflammation in the liver is an important driver of disease progression in NASH and associated matrix remodeling/fibrosis. However, the exact molecular inflammatory mechanisms are poorly defined in human studies. Investigation of key pathogenic mechanisms requires the use of pre-clinical models, for instance for time-resolved studies. Such models must reflect molecular disease processes of importance in patients. Herein we characterized inflammation in NASH patients on the molecular level by transcriptomics and investigated whether key human disease pathways can be recapitulated experimentally in Ldlr−/−.Leiden mice, an established pre-clinical model of NASH. Methods: Human molecular inflammatory processes were defined using a publicly available NASH gene expression profiling dataset (GSE48452) allowing the comparison of biopsy-confirmed NASH patients with normal controls. Gene profiling data from high-fat diet (HFD)-fed Ldlr−/−.Leiden mice (GSE109345) were used for assessment of the translational value of these mice. Results: In human NASH livers, we observed regulation of 65 canonical pathways of which the majority was involved in inflammation (32%), lipid metabolism (16%), and extracellular matrix/remodeling (12%). A similar distribution of pathways across these categories, inflammation (36%), lipid metabolism (24%) and extracellular matrix/remodeling (8%) was observed in HFD-fed Ldlr−/−.Leiden mice. Detailed evaluation of these pathways revealed that a substantial proportion (11 out of 13) of human NASH inflammatory pathways was recapitulated in Ldlr−/−.Leiden mice. Furthermore, the activation state of identified master regulators of inflammation (i.e., specific transcription factors, cytokines, and growth factors) in human NASH was largely reflected in Ldlr−/−.Leiden mice, further substantiating its translational value. Conclusion: Human NASH is characterized by upregulation of specific

Packaging signals in single-stranded RNA viruses: nature?s alternative to a purely electrostatic assembly mechanism

OpenAIRE

Stockley, Peter G.; Twarock, Reidun; Bakker, Saskia E.; Barker, Amy M.; Borodavka, Alexander; Dykeman, Eric; Ford, Robert J.; Pearson, Arwen R.; Phillips, Simon E. V.; Ranson, Neil A.; Tuma, Roman

2013-01-01

The formation of a protective protein container is an essential step in the life-cycle of most viruses. In the case of single-stranded (ss)RNA viruses, this step occurs in parallel with genome packaging in a co-assembly process. Previously, it had been thought that this process can be explained entirely by electrostatics. Inspired by recent single-molecule fluorescence experiments that recapitulate the RNA packaging specificity seen in vivo for two model viruses, we present an alternative the...

Experimentation of nuclear weapons, releases and storages of radioactive wastes in the Kara sea and in New Zemble

International Nuclear Information System (INIS)

Charmasson, S.

1996-01-01

132 nuclear weapons were tested from 1955 to 1990 in New Zemble. From 1959 to 1993, low level liquid radioactive wastes, low and medium level solid radioactive wastes, reactor core and fuel of submarine and nuclear propelled ships were released in the Kara and the Barentz seas. For these two seas, a recapitulation of the different radioactive sources and the found level of radioactivity of the marine environment are presented. (A.B.). 22 refs. 4 figs., 6 tabs

A Markov chain model for N-linked protein glycosylation – towards a low-parameter tool for model-driven glycoengineering

DEFF Research Database (Denmark)

Spahn, Philipp N.; Hansen, Anders Holmgaard; Hansen, Henning Gram

2016-01-01

Glycosylation is a critical quality attribute of most recombinant biotherapeutics. Consequently, drug development requires careful control of glycoforms to meet bioactivity and biosafety requirements. However, glycoengineering can be extraordinarily difficult given the complex reaction networks...... present a novel low-parameter approach to describe glycosylation using flux-balance and Markov chain modeling. The model recapitulates the biological complexity of glycosylation, but does not require user-provided kinetic information. We use this method to predict and experimentally validate glycoprofiles...

Rapid In Vivo Validation of Tumor Suppressor Gene Function in Prostate Cancer Progression

Science.gov (United States)

2016-07-01

identification of the best sgRNA sequences and accelerated our ability to move to the in vivo studies proposed in Aim2. Our goal was to use CRISPR / Cas ...and to initiate prostate cancer in the mouse after injection of lentiviral particles expressing CRISPR / Cas components and Cre recombinase. Our initial...in vivo Our goal was to use CRISPR / Cas lentiviral transduction of the adult prostate to inactivate p53 or Rb. We aimed to recapitulate the effects of

Animal models for Gaucher disease research

OpenAIRE

Farfel-Becker, Tamar; Vitner, Einat B.; Futerman, Anthony H.

2011-01-01

Gaucher disease (GD), the most common lysosomal storage disorder (LSD), is caused by the defective activity of the lysosomal hydrolase glucocerebrosidase, which is encoded by the GBA gene. Generation of animal models that faithfully recapitulate the three clinical subtypes of GD has proved to be more of a challenge than first anticipated. The first mouse to be produced died within hours after birth owing to skin permeability problems, and mice with point mutations in Gba did not display sympt...

Chelation and flotation in endodontic practice: an update.

Science.gov (United States)

Stewart, G G

1986-10-01

The removal of broken instruments and silver points, as well as pulp tissue, may be accomplished by careful instrumentation, irrigation, and flotation. Flotation and recapitulation with smaller instruments and irrigation with copious amounts of sodium hypochlorite can clean out microorganisms and the organic matter from the tubular structure which provides a more ideal surface for sealing the root canal system. A sterile environment was obtained by removing the substrate and creating a more ideal environment for better healing.

Administration of vitamin K does not counteract the ectopic mineralization of connective tissues in Abcc6−/− mice, a model for pseudoxanthoma elasticum

OpenAIRE

Jiang, Qiujie; Li, Qiaoli; Grand-Pierre, Alix E; Schurgers, Leon J; Uitto, Jouni

2011-01-01

Pseudoxanthoma elasticum (PXE) is a heritable multisystem disorder manifesting with ectopic calcification of peripheral connective tissues, caused by mutations in the ABCC6 gene. Alterations in vitamin K metabolism have been suggested to contribute to the pathomechanisms of the mineralization process. In this study we administered vitamin K or its glutathione conjugate (K3-GSH) into Abcc6−/− mice that recapitulate features of PXE. Oral administration of vitamin K2, in dosages that vastly exce...

A Biochemical Screen for Identification of Small-Molecule Regulators of the Wnt Pathway Using Xenopus Egg Extracts

OpenAIRE

Thorne, Curtis A.; Lafleur, Bonnie; Lewis, Michelle; Hanson, Alison J.; Jernigan, Kristin K.; Weaver, David C.; Huppert, Kari A.; Chen, Tony W.; Wichadiit, Chonlarat; Cselenyi, Christopher S.; Tahinci, Emilios; Meyers, Kelly C.; Waskow, Emily; Orton, Darren; Salic, Adrian

2011-01-01

Misregulation of the Wnt pathway has been shown to be responsible for a variety of human diseases, most notably cancers. Screens for inhibitors of this pathway have been performed almost exclusively using cultured mammalian cells or with purified proteins. We have previously developed a biochemical assay using Xenopus egg extracts to recapitulate key cytoplasmic events in the Wnt pathway. Using this biochemical system, we show that a recombinant form of the Wnt coreceptor, LRP6, regulates the...

Oxytocin signaling in the medial amygdala is required for sex discrimination of social cues

OpenAIRE

Yao, Shenqin; Bergan, Joseph; Lanjuin, Anne; Dulac, Catherine

2017-01-01

The neural control of social behaviors in rodents requires the encoding of pheromonal cues by the vomeronasal system. Here we show that the typical preference of male mice for females is eliminated in mutants lacking oxytocin, a neuropeptide modulating social behaviors in many species. Ablation of the oxytocin receptor in aromatase-expressing neurons of the medial amygdala (MeA) fully recapitulates the elimination of female preference in males. Further, single-unit recording in the MeA uncove...

Oxytocin Signaling in the Medial Amygdala is required for Sex Discrimination of Social Cues

OpenAIRE

Bergan, Joseph; Yao, Shenqin; Lanjuin, Anne; Dulac, Catherine

2017-01-01

The neural control of social behaviors in rodents requires the encoding of pheromonal cues by the vomeronasal system. Here we show that the typical preference of male mice for females is eliminated in mutants lacking oxytocin, a neuropeptide modulating social behaviors in many species. Ablation of the oxytocin receptor in aromatase expressing neurons of the medial amygdala (MeA) fully recapitulates the elimination of female preference in males. Further, single unit recording in the MeA uncove...

Automatic Exchange of Information as the new global standard: the end of (offshore tax evasion) history?

OpenAIRE

Meinzer, Markus

2017-01-01

Automatic exchange of information (AEoI) for tax purposes has become the global standard for international tax cooperation in 2013. As a tool for containing offshore tax evasion, it has encountered opposition in the past and continues to be fraught with challenges. This paper recapitulates the rationale for AEoI, including estimates on the magnitudes of assets held offshore, with a specific focus on Turkish assets held in Germany (chapter 1). Subsequently, chapter 2 summarises the recent hist...

Recuperation of the Roman circus in Tarragona

Directory of Open Access Journals (Sweden)

Ricardo Mar

1998-12-01

Full Text Available It is an ambitious operation in archaeology, architectural and urbanistic restoration suitable for an ensemble that deserves to be considered a World Heritage Site. There will still be a delicate architectural restoration task to be carried out once the current excavations have been completed, so that is a good time to recapitulate and present a summary of the methodology used till today, contribute from LOGGIA to its diffusion, and encourage great success for the future.

Voluntary sport and highway risks in adolescents and youths (following current French and Canadian periodical publications of 2000th

Directory of Open Access Journals (Sweden)

Rabinovich M.I.

2013-06-01

Full Text Available In this article we discuss some personal traits of adolescents and young people, disposed to different types of risky behavior. We describe correlations between different types of risky behavior in one individual. We discuss also the gender aspect of risk taking in adolescents and youth. Some modern theories of risk taking are recapitulated. Finally, we discuss the organizational question about the preventive work with adolescents and youth, aimed on minimization of sportive and highway risk.

Modeling Human Nonalcoholic Steatohepatitis-Associated Changes in Drug Transporter Expression Using Experimental Rodent Models

OpenAIRE

Canet, Mark J.; Hardwick, Rhiannon N.; Lake, April D.; Dzierlenga, Anika L.; Clarke, John D.; Cherrington, Nathan J.

2014-01-01

Nonalcoholic fatty liver disease is a prevalent form of chronic liver disease that can progress to the more advanced stage of nonalcoholic steatohepatitis (NASH). NASH has been shown to alter drug transporter regulation and may have implications in the development of adverse drug reactions. Several experimental rodent models have been proposed for the study of NASH, but no single model fully recapitulates all aspects of the human disease. The purpose of the current study was to determine whic...

Subverting the Dominant Order: Narrative as Weapon in Simone de Beauvoir's Tous les hommes sont mortels

OpenAIRE

Barbara Klaw

1996-01-01

This essay argues that through the narrative techniques of point of view and embedding, Beauvoir carefully constructed her narrative and those of her male and female characters in Tous les hommes sont mortels , her third novel, published in 1946, in order to explain why males dominate society and to encourage women to fight against the current patriarchal social order. Many critics view Fosca as the principal character, and his 400-page embedded recapitulation of his past as the predominant ...

Sex-Specific Skeletal Muscle Fatigability and Decreased Mitochondrial Oxidative Capacity in Adult Rats Exposed to Postnatal Hyperoxia

Directory of Open Access Journals (Sweden)

Laura H. Tetri

2018-03-01

Full Text Available Premature birth affects more than 10% of live births, and is characterized by relative hyperoxia exposure in an immature host. Long-term consequences of preterm birth include decreased aerobic capacity, decreased muscular strength and endurance, and increased prevalence of metabolic diseases such as type 2 diabetes mellitus. Postnatal hyperoxia exposure in rodents is a well-established model of chronic lung disease of prematurity, and also recapitulates the pulmonary vascular, cardiovascular, and renal phenotype of premature birth. The objective of this study was to evaluate whether postnatal hyperoxia exposure in rats could recapitulate the skeletal and metabolic phenotype of premature birth, and to characterize the subcellular metabolic changes associated with postnatal hyperoxia exposure, with a secondary aim to evaluate sex differences in this model. Compared to control rats, male rats exposed to 14 days of postnatal hyperoxia then aged to 1 year demonstrated higher skeletal muscle fatigability, lower muscle mitochondrial oxidative capacity, more mitochondrial damage, and higher glycolytic enzyme expression. These differences were not present in female rats with the same postnatal hyperoxia exposure. This study demonstrates detrimental mitochondrial and muscular outcomes in the adult male rat exposed to postnatal hyperoxia. Given that young adults born premature also demonstrate skeletal muscle dysfunction, future studies are merited to determine whether this dysfunction as well as reduced aerobic capacity is due to reduced mitochondrial oxidative capacity and metabolic dysfunction.

Maternal immune activation in rats produces temporal perception impairments in adult offspring analogous to those observed in schizophrenia.

Directory of Open Access Journals (Sweden)

Ashley R Deane

Full Text Available The neurophysiology underlying temporal perception significantly overlaps with areas of dysfunction identified in schizophrenia. Patients commonly exhibit distorted temporal perception, which likely contributes to functional impairments. Thus, study of temporal perception in animal models of the disease may help to understand both cognitive and neurobiological factors involved in functional impairments in patients. As maternal immune activation (MIA has been shown to be a significant etiological risk factor in development of schizophrenia and other developmental psychiatric diseases, we tested interval timing in a rat model of MIA that has previously been shown to recapitulate several behavioural and neurophysiological impairments observed in the disease. Rats were tested on a temporal-bisection task, in which temporal duration stimuli were categorized as either "short" or "long" by responding to a corresponding lever. Data from this task were modeled to provide estimates of accuracy and sensitivity of temporal perception. Parameter estimates derived from the model fitting showed that MIA rats significantly overestimated the passage of time compared to controls. These results indicate that the MIA rat paradigm recapitulates timing distortions that are phenotypical of schizophrenia. These findings lend further support to the epidemiological validity of this MIA rat model, supporting its relevance for future research into the role of maternal immune activation in producing neurobiological and behavioural impairments in schizophrenia.

Roles of PAD4 and NETosis in Experimental Atherosclerosis and Arterial Injury: Implications for Superficial Erosion.

Science.gov (United States)

Franck, Grégory; Mawson, Thomas L; Folco, Eduardo J; Molinaro, Roberto; Ruvkun, Victoria; Engelbertsen, Daniel; Liu, Xin; Tesmenitsky, Yevgenia; Shvartz, Eugenia; Sukhova, Galina K; Michel, Jean-Baptiste; Nicoletti, Antonino; Lichtman, Andrew; Wagner, Denisa; Croce, Kevin J; Libby, Peter

2018-06-22

Neutrophils likely contribute to the thrombotic complications of human atheromata. In particular, neutrophil extracellular traps (NETs) could exacerbate local inflammation and amplify and propagate arterial intimal injury and thrombosis. PAD4 (peptidyl arginine deiminase 4) participates in NET formation, but an understanding of this enzyme's role in atherothrombosis remains scant. This study tested the hypothesis that PAD4 and NETs influence experimental atherogenesis and in processes implicated in superficial erosion, a form of plaque complication we previously associated with NETs. Bone marrow chimeric Ldlr deficient mice reconstituted with either wild-type or PAD4-deficient cells underwent studies that assessed atheroma formation or procedures designed to probe mechanisms related to superficial erosion. PAD4 deficiency neither retarded fatty streak formation nor reduced plaque size or inflammation in bone marrow chimeric mice that consumed an atherogenic diet. In contrast, either a PAD4 deficiency in bone marrow-derived cells or administration of DNaseI to disrupt NETs decreased the extent of arterial intimal injury in mice with arterial lesions tailored to recapitulate characteristics of human atheroma complicated by erosion. These results indicate that PAD4 from bone marrow-derived cells and NETs do not influence chronic experimental atherogenesis, but participate causally in acute thrombotic complications of intimal lesions that recapitulate features of superficial erosion. © 2018 American Heart Association, Inc.

Three-Dimensional In Vitro Skin and Skin Cancer Models Based on Human Fibroblast-Derived Matrix.

Science.gov (United States)

Berning, Manuel; Prätzel-Wunder, Silke; Bickenbach, Jackie R; Boukamp, Petra

2015-09-01

Three-dimensional in vitro skin and skin cancer models help to dissect epidermal-dermal and tumor-stroma interactions. In the model presented here, normal human dermal fibroblasts isolated from adult skin self-assembled into dermal equivalents with their specific fibroblast-derived matrix (fdmDE) over 4 weeks. The fdmDE represented a complex human extracellular matrix that was stabilized by its own heterogeneous collagen fiber meshwork, largely resembling a human dermal in vivo architecture. Complemented with normal human epidermal keratinocytes, the skin equivalent (fdmSE) thereof favored the establishment of a well-stratified and differentiated epidermis and importantly allowed epidermal regeneration in vitro for at least 24 weeks. Moreover, the fdmDE could be used to study the features of cutaneous skin cancer. Complementing fdmDE with HaCaT cells in different stages of malignancy or tumor-derived cutaneous squamous cell carcinoma cell lines, the resulting skin cancer equivalents (fdmSCEs) recapitulated the respective degree of tumorigenicity. In addition, the fdmSCE invasion phenotypes correlated with their individual degree of tissue organization, disturbance in basement membrane organization, and presence of matrix metalloproteinases. Together, fdmDE-based models are well suited for long-term regeneration of normal human epidermis and, as they recapitulate tumor-specific growth, differentiation, and invasion profiles of cutaneous skin cancer cells, also provide an excellent human in vitro skin cancer model.

Energy utilization of induced pluripotent stem cell-derived cardiomyocyte in Fabry disease.

Science.gov (United States)

Chou, Shih-Jie; Yu, Wen-Chung; Chang, Yuh-Lih; Chen, Wen-Yeh; Chang, Wei-Chao; Chien, Yueh; Yen, Jiin-Cherng; Liu, Yung-Yang; Chen, Shih-Jen; Wang, Chien-Ying; Chen, Yu-Han; Niu, Dau-Ming; Lin, Shing-Jong; Chen, Jaw-Wen; Chiou, Shih-Hwa; Leu, Hsin-Bang

2017-04-01

Fabry disease (FD) is a lysosomal storage disease in which glycosphingolipids (GB3) accumulate in organs of the human body, leading to idiopathic hypertrophic cardiomyopathy and target organ damage. Its pathophysiology is still poorly understood. We aimed to generate patient-specific induced pluripotent stem cells (iPSC) from FD patients presenting cardiomyopathy to determine whether the model could recapitulate key features of the disease phenotype and to investigate the energy metabolism in Fabry disease. Peripheral blood mononuclear cells from a 30-year-old Chinese man with a diagnosis of Fabry disease, GLA gene (IVS4+919G>A) mutation were reprogrammed into iPSCs and differentiated into iPSC-CMs and energy metabolism was analyzed in iPSC-CMs. The FD-iPSC-CMs recapitulated numerous aspects of the FD phenotype including reduced GLA activity, cellular hypertrophy, GB3 accumulation and impaired contractility. Decreased energy metabolism with energy utilization shift to glycolysis was observed, but the decreased energy metabolism was not modified by enzyme rescue replacement (ERT) in FD-iPSCs-CMs. This model provided a promising in vitro model for the investigation of the underlying disease mechanism and development of novel therapeutic strategies for FD. This potential remedy for enhancing the energetic network and utility efficiency warrants further study to identify novel therapies for the disease. Copyright © 2017 Elsevier B.V. All rights reserved.

Antitumor effects of regorafenib and sorafenib in preclinical models of hepatocellular carcinoma

OpenAIRE

Kissel, Maria; Berndt, Sandra; Fiebig, Lukas; Kling, Simon; Ji, Qunsheng; Gu, Qingyang; Lang, Tina; Hafner, Frank-Thorsten; Teufel, Michael; Zopf, Dieter

2017-01-01

The purpose of this study was to investigate the antitumor activity of regorafenib and sorafenib in preclinical models of HCC and to assess their mechanism of action by associated changes in protein expression in a HCC-PDX mouse model. Both drugs were administered orally once daily at 10 mg/kg (regorafenib) or 30 mg/kg (sorafenib), which recapitulate the human exposure at the maximally tolerated dose in mice. In a H129 hepatoma model, survival times differed significantly between regorafenib ...

Sun, weather, and climate

International Nuclear Information System (INIS)

Herman, J.R.; Goldberg, R.A.

1985-01-01

The general field of sun-weather/climate relationships that is, apparent weather and climate responses to solar activity is introduced and theoretical and experimental suggestions for further research to identify and investigate the unknown casual mechanisms are provided. Topics of discussion include: (1) solar-related correlation factors and energy sources; (2) long-term climate trends; (3) short-term meteorological correlations; (4) miscellaneous obscuring influences; (5) physical processes and mechanisms; (6) recapitulation of sun-weather relationships; and (7) guidelines for experiments. 300 references

Portugal and Spain entering the Common Market: Their industrial competitiveness revisited

OpenAIRE

Donges, Jürgen B.; Schatz, Klaus-Werner

1985-01-01

The purpose of this paper is to assess the overall position as well as the relative strength and weakness of the Iberian manufacturing industries within an enlarged Community. Earlier studies of the authors (Donges, Schatzf 1980; Donges et al., 1982) are up-dated and extended to cover the bilateral trade relations between Portugal and Spain. Following a recapitulation of the major trade patterns of the Iberian countries, we examine the nature of their specialization, both with regard to the E...

[Hyperammonemia type II as an example of urea cycle disorder].

Science.gov (United States)

Hawrot-Kawecka, Anna M; Kawecki, Grzegorz P; Duława, Jan

2006-01-01

Ornithine transcarbamylase deficiency is the most common inherited urea cycle disorder. Its clinical manifestations as lethargy, vomites, coma and cerebral edema are the effect of the higher concentration of the ammonia in plasma. Hyperammonemia, caused by mutation in ornithine transcarbamylase gene, is often considered as a reason of coma by pediatricians but skipped by internist, although it is the third reason of hepatic coma in adults. This article is the recapitulation of published studies and their implication on everyday clinical practice.

PKD1 Mono-Allelic Knockout Is Sufficient to Trigger Renal Cystogenesis in a Mini-Pig Model

OpenAIRE

He, Jin; Li, Qiuyan; Fang, Suyun; Guo, Ying; Liu, Tongxin; Ye, Jianhua; Yu, Zhengquan; Zhang, Ran; Zhao, Yaofeng; Hu, Xiaoxiang; Bai, Xueyuan; Chen, Xiangmei; Li, Ning

2015-01-01

PKD1 and PKD2 mutations could lead to autosomal dominant polycystic kidney disease (ADPKD), which afflicts millions of people worldwide. Due to the marked differences in the lifespan, size, anatomy, and physiology from humans, rodent ADPKD models cannot fully mimic the disease. To obtain a large animal model that recapitulates the disease, we constructed a mini-pig model by mono-allelic knockout (KO) of PKD1 using zinc finger nuclease. The mono-allelic KO pigs had lower PKD1 expression than t...

Covariance dynamics and symmetries, and hadron form factors

International Nuclear Information System (INIS)

Bhagwat, M.S.; Cloet, I.C.; Roberts, C.D.

2007-01-01

We summarize applications of Dyson-Schwinger equations to the theory and phenomenology of hadrons. Some exact results for pseudoscalar mesons are highlighted with details relating to the U A (1) problem. We describe inferences from the gap equation relating to the radius of convergence for expansions of observables in the current-quark mass. We recapitulate upon studies of nucleon electromagnetic form factors, providing a comparison of the ln-weighted ratios of Pauli and Dirac form factors for the neutron and proton.

A neurite quality index and machine vision software for improved quantification of neurodegeneration.

Science.gov (United States)

Romero, Peggy; Miller, Ted; Garakani, Arman

2009-12-01

Current methods to assess neurodegradation in dorsal root ganglion cultures as a model for neurodegenerative diseases are imprecise and time-consuming. Here we describe two new methods to quantify neuroprotection in these cultures. The neurite quality index (NQI) builds upon earlier manual methods, incorporating additional morphological events to increase detection sensitivity for the detection of early degeneration events. Neurosight is a machine vision-based method that recapitulates many of the strengths of NQI while enabling high-throughput screening applications with decreased costs.

Notas sobre las transformaciones psíquicas de la adolescencia en la historia del psicoanálisis

Directory of Open Access Journals (Sweden)

Mauricio Fernández Arcila

2014-07-01

Full Text Available The determinism of childhood captured the attention of psychoanalytic thought and overshadowed the crucial role of adolescence, which Freud himself recognized. New approaches to the specificity and importance of adolescence begin to crop up in the mid-twentieth century, supported in clinical practice with adolescents developed after WWII. Finally the integration of the concept of "afterwards" {Nachträglichkeit} in these theories best validates the thesis that adolescent psychic transformations are not confined to the recapitulation of previous problems.

[Chakrabarty today: 30 years after the United States Supreme Court Resolution].

Science.gov (United States)

Bergel, Salvador Darío

2010-01-01

The decision of the United States Supreme Court in the Chakrabarty case marked the beginning of a far reaching process, the development of which considerably extended the field of patentabiltiy of humans, their body parts and genetic information. The author believes that a period of three decades is sufficient to draw conclusions. A critical point has been reached from a debatable decision, which had more economic support than legal, which requires serious recapitulation of the scope and the purpose of industrial property rights.

Three-dimensional neural cultures produce networks that mimic native brain activity.

Science.gov (United States)

Bourke, Justin L; Quigley, Anita F; Duchi, Serena; O'Connell, Cathal D; Crook, Jeremy M; Wallace, Gordon G; Cook, Mark J; Kapsa, Robert M I

2018-02-01

Development of brain function is critically dependent on neuronal networks organized through three dimensions. Culture of central nervous system neurons has traditionally been limited to two dimensions, restricting growth patterns and network formation to a single plane. Here, with the use of multichannel extracellular microelectrode arrays, we demonstrate that neurons cultured in a true three-dimensional environment recapitulate native neuronal network formation and produce functional outcomes more akin to in vivo neuronal network activity. Copyright © 2017 John Wiley & Sons, Ltd.

Cerebellar Ataxia and Coenzyme Q Deficiency Through Loss of Unorthodox Kinase Activity

OpenAIRE

Stefely, Jonathan A.; Licitra, Floriana; Laredj, Leila; Reidenbach, Andrew G.; Kemmerer, Zachary A.; Grangeray, Anais; Jaeg-Ehret, Tiphaine; Minogue, Catherine E.; Ulbrich, Arne; Hutchins, Paul D.; Wilkerson, Emily M.; Ruan, Zheng; Aydin, Deniz; Hebert, Alexander S.; Guo, Xiao

2016-01-01

The UbiB protein kinase-like (PKL) family is widespread—comprising one-quarter of microbial PKLs and five human homologs—yet its biochemical activities remain obscure. COQ8A (ADCK3) is a mammalian UbiB protein associated with ubiquinone (CoQ) biosynthesis and an ataxia (ARCA2) through unclear means. We show that mice lacking COQ8A develop a slowly progressive cerebellar ataxia linked to Purkinje cell dysfunction and mild exercise intolerance, recapitulating ARCA2. Interspecies biochemical ana...

Optimization of a murine and human tissue model to recapitulate dermal and pulmonary features of systemic sclerosis.

Directory of Open Access Journals (Sweden)

Tomoya Watanabe

Full Text Available The murine bleomycin (BLM-induced fibrosis model is the most widely used in systemic sclerosis (SSc studies. It has been reported that systemic delivery of BLM via continuous diffusion from subcutaneously implanted osmotic minipumps can cause fibrosis of the skin, lungs, and other internal organs. However, the mouse strain, dosage of BLM, administration period, and additional important features differ from one report to the next. In this study, by employing the pump model in C57BL/6J mice, we show a dose-dependent increase in lung fibrosis by day 28 and a transient increase in dermal thickness. Dermal thickness and the level of collagen in skin treated with high-dose BLM was significantly higher than in skin treated with low dose BLM or vehicle. A reduction in the thickness of the adipose layer was noted in both high and low dose groups at earlier time points suggesting that the loss of the fat layer precedes the onset of fibrosis. High-dose BLM also induced dermal fibrosis and increased expression of fibrosis-associated genes ex vivo in human skin, thus confirming and extending the in vivo findings, and demonstrating that a human organ culture model can be used to assess the effect of BLM on skin. In summary, our findings suggest that the BLM pump model is an attractive model to analyze the underlying mechanisms of fibrosis and test the efficacy of potential therapies. However, the choice of mouse strain, duration of BLM administration and dose must be carefully considered when using this model.

Recapitulation of spinal motor neuron-specific disease phenotypes in a human cell model of spinal muscular atrophy

Institute of Scientific and Technical Information of China (English)

Zhi-Bo Wang; Xiaoqing Zhang; Xue-Jun Li

2013-01-01

Establishing human cell models of spinal muscular atrophy (SMA) to mimic motor neuron-specific phenotypes holds the key to understanding the pathogenesis of this devastating disease.Here,we developed a closely representative cell model of SMA by knocking down the disease-determining gene,survival motor neuron (SMN),in human embryonic stem cells (hESCs).Our study with this cell model demonstrated that knocking down of SMN does not interfere with neural induction or the initial specification of spinal motor neurons.Notably,the axonal outgrowth of spinal motor neurons was significantly impaired and these disease-mimicking neurons subsequently degenerated.Furthermore,these disease phenotypes were caused by SMN-full length (SMN-FL) but not SMN-A7 (lacking exon 7)knockdown,and were specific to spinal motor neurons.Restoring the expression of SMN-FL completely ameliorated all of the disease phenotypes,including specific axonal defects and motor neuron loss.Finally,knockdown of SMNFL led to excessive mitochondrial oxidative stress in human motor neuron progenitors.The involvement of oxidative stress in the degeneration of spinal motor neurons in the SMA cell model was further confirmed by the administration of N-acetylcysteine,a potent antioxidant,which prevented disease-related apoptosis and subsequent motor neuron death.Thus,we report here the successful establishment of an hESC-based SMA model,which exhibits disease gene isoform specificity,cell type specificity,and phenotype reversibility.Our model provides a unique paradigm for studying how motor neurons specifically degenerate and highlights the potential importance of antioxidants for the treatment of SMA.

The orthotopic xenotransplant of human glioblastoma successfully recapitulates glioblastoma-microenvironment interactions in a non-immunosuppressed mouse model.

Science.gov (United States)

Garcia, Celina; Dubois, Luiz Gustavo; Xavier, Anna Lenice; Geraldo, Luiz Henrique; da Fonseca, Anna Carolina Carvalho; Correia, Ana Helena; Meirelles, Fernanda; Ventura, Grasiella; Romão, Luciana; Canedo, Nathalie Henriques Silva; de Souza, Jorge Marcondes; de Menezes, João Ricardo Lacerda; Moura-Neto, Vivaldo; Tovar-Moll, Fernanda; Lima, Flavia Regina Souza

2014-12-08

Glioblastoma (GBM) is the most common primary brain tumor and the most aggressive glial tumor. This tumor is highly heterogeneous, angiogenic, and insensitive to radio- and chemotherapy. Here we have investigated the progression of GBM produced by the injection of human GBM cells into the brain parenchyma of immunocompetent mice. Xenotransplanted animals were submitted to magnetic resonance imaging (MRI) and histopathological analyses. Our data show that two weeks after injection, the produced tumor presents histopathological characteristics recommended by World Health Organization for the diagnosis of GBM in humans. The tumor was able to produce reactive gliosis in the adjacent parenchyma, angiogenesis, an intense recruitment of macrophage and microglial cells, and presence of necrosis regions. Besides, MRI showed that tumor mass had enhanced contrast, suggesting a blood-brain barrier disruption. This study demonstrated that the xenografted tumor in mouse brain parenchyma develops in a very similar manner to those found in patients affected by GBM and can be used to better understand the biology of GBM as well as testing potential therapies.

Anti-proteinase 3 anti-neutrophil cytoplasm autoantibodies recapitulate systemic vasculitis in mice with a humanized immune system.

Directory of Open Access Journals (Sweden)

Mark A Little

Full Text Available Evidence is lacking for direct pathogenicity of human anti-proteinase-3 (PR3 antibodies in development of systemic vasculitis and granulomatosis with polyangiitis (GPA, Wegener's granulomatosis. Progress in study of these antibodies in rodents has been hampered by lack of PR3 expression on murine neutrophils, and by different Fc-receptor affinities for IgG across species. Therefore, we tested whether human anti-PR3 antibodies can induce acute vasculitis in mice with a human immune system. Chimeric mice were generated by injecting human haematopoietic stem cells into irradiated NOD-scid-IL2Rγ⁻/⁻ mice. Matched chimera mice were treated with human IgG from patients with: anti-PR3 positive renal and lung vasculitis; patients with non-vasculitic renal disease; or healthy controls. Six-days later, 39% of anti-PR3 treated mice had haematuria, compared with none of controls. There was punctate bleeding on the surface of lungs of anti-PR3 treated animals, with histological evidence of vasculitis and haemorrhage. Anti-PR3 treated mice had mild pauci-immune proliferative glomerulonephritis, with infiltration of human and mouse leukocytes. In 3 mice (17% more severe glomerular injury was present. There were no glomerular changes in controls. Human IgG from patients with anti-PR3 autoantibodies is therefore pathogenic. This model of anti-PR3 antibody-mediated vasculitis may be useful in dissecting mechanisms of microvascular injury.

Simian varicella virus infection of rhesus macaques recapitulates essential features of varicella zoster virus infection in humans.

Directory of Open Access Journals (Sweden)

Ilhem Messaoudi

2009-11-01

Full Text Available Simian varicella virus (SVV, the etiologic agent of naturally occurring varicella in primates, is genetically and antigenically closely related to human varicella zoster virus (VZV. Early attempts to develop a model of VZV pathogenesis and latency in nonhuman primates (NHP resulted in persistent infection. More recent models successfully produced latency; however, only a minority of monkeys became viremic and seroconverted. Thus, previous NHP models were not ideally suited to analyze the immune response to SVV during acute infection and the transition to latency. Here, we show for the first time that intrabronchial inoculation of rhesus macaques with SVV closely mimics naturally occurring varicella (chickenpox in humans. Infected monkeys developed varicella and viremia that resolved 21 days after infection. Months later, viral DNA was detected only in ganglia and not in non-ganglionic tissues. Like VZV latency in human ganglia, transcripts corresponding to SVV ORFs 21, 62, 63 and 66, but not ORF 40, were detected by RT-PCR. In addition, as described for VZV, SVV ORF 63 protein was detected in the cytoplasm of neurons in latently infected monkey ganglia by immunohistochemistry. We also present the first in depth analysis of the immune response to SVV. Infected animals produced a strong humoral and cell-mediated immune response to SVV, as assessed by immunohistology, serology and flow cytometry. Intrabronchial inoculation of rhesus macaques with SVV provides a novel model to analyze viral and immunological mechanisms of VZV latency and reactivation.

Anti-proteinase 3 anti-neutrophil cytoplasm autoantibodies recapitulate systemic vasculitis in mice with a humanized immune system.

LENUS (Irish Health Repository)

Little, Mark A

2012-01-01

Evidence is lacking for direct pathogenicity of human anti-proteinase-3 (PR3) antibodies in development of systemic vasculitis and granulomatosis with polyangiitis (GPA, Wegener\\'s granulomatosis). Progress in study of these antibodies in rodents has been hampered by lack of PR3 expression on murine neutrophils, and by different Fc-receptor affinities for IgG across species. Therefore, we tested whether human anti-PR3 antibodies can induce acute vasculitis in mice with a human immune system. Chimeric mice were generated by injecting human haematopoietic stem cells into irradiated NOD-scid-IL2Rγ⁻\\/⁻ mice. Matched chimera mice were treated with human IgG from patients with: anti-PR3 positive renal and lung vasculitis; patients with non-vasculitic renal disease; or healthy controls. Six-days later, 39% of anti-PR3 treated mice had haematuria, compared with none of controls. There was punctate bleeding on the surface of lungs of anti-PR3 treated animals, with histological evidence of vasculitis and haemorrhage. Anti-PR3 treated mice had mild pauci-immune proliferative glomerulonephritis, with infiltration of human and mouse leukocytes. In 3 mice (17%) more severe glomerular injury was present. There were no glomerular changes in controls. Human IgG from patients with anti-PR3 autoantibodies is therefore pathogenic. This model of anti-PR3 antibody-mediated vasculitis may be useful in dissecting mechanisms of microvascular injury.

A recapitulation of the Nearctic species of Centromerus Dahl (Araneida, Linyphiidae) with remarks on Tunagyna Debilis (Banks)

NARCIS (Netherlands)

Helsdingen, van P.J.

1973-01-01

In any new region the knowledge of the spider fauna, or of any other group of organisms, has to go through three successive stages. In the beginning there is a period of descriptive activity with many new species recorded and named, in the past usually by several authors independently. In the

Integrating 4-d light-sheet imaging with interactive virtual reality to recapitulate developmental cardiac mechanics and physiology

Science.gov (United States)

Ding, Yichen; Yu, Jing; Abiri, Arash; Abiri, Parinaz; Lee, Juhyun; Chang, Chih-Chiang; Baek, Kyung In; Sevag Packard, René R.; Hsiai, Tzung K.

2018-02-01

There currently is a limited ability to interactively study developmental cardiac mechanics and physiology. We therefore combined light-sheet fluorescence microscopy (LSFM) with virtual reality (VR) to provide a hybrid platform for 3- dimensional (3-D) architecture and time-dependent cardiac contractile function characterization. By taking advantage of the rapid acquisition, high axial resolution, low phototoxicity, and high fidelity in 3-D and 4-D (3-D spatial + 1-D time or spectra), this VR-LSFM hybrid methodology enables interactive visualization and quantification otherwise not available by conventional methods such as routine optical microscopes. We hereby demonstrate multi-scale applicability of VR-LSFM to 1) interrogate skin fibroblasts interacting with a hyaluronic acid-based hydrogel, 2) navigate through the endocardial trabecular network during zebrafish development, and 3) localize gene therapy-mediated potassium channel expression in adult murine hearts. We further combined our batch intensity normalized segmentation (BINS) algorithm with deformable image registration (DIR) to interface a VR environment for the analysis of cardiac contraction. Thus, the VR-LSFM hybrid platform demonstrates an efficient and robust framework for creating a user-directed microenvironment in which we uncovered developmental cardiac mechanics and physiology with high spatiotemporal resolution.

Subdivision of arthropod cap-n-collar expression domains is restricted to Mandibulata

Science.gov (United States)

2014-01-01

Background The monophyly of Mandibulata - the division of arthropods uniting pancrustaceans and myriapods - is consistent with several morphological characters, such as the presence of sensory appendages called antennae and the eponymous biting appendage, the mandible. Functional studies have demonstrated that the patterning of the mandible requires the activity of the Hox gene Deformed and the transcription factor cap-n-collar (cnc) in at least two holometabolous insects: the fruit fly Drosophila melanogaster and the beetle Tribolium castaneum. Expression patterns of cnc from two non-holometabolous insects and a millipede have suggested conservation of the labral and mandibular domains within Mandibulata. However, the activity of cnc is unknown in crustaceans and chelicerates, precluding understanding of a complete scenario for the evolution of patterning of this appendage within arthropods. To redress these lacunae, here we investigate the gene expression of the ortholog of cnc in Parhyale hawaiensis, a malacostracan crustacean, and two chelicerates: the harvestman Phalangium opilio, and the scorpion Centruroides sculpturatus. Results In the crustacean P. hawaiensis, the segmental expression of Ph-cnc is the same as that reported previously in hexapods and myriapods, with two distinct head domains in the labrum and the mandibular segment. In contrast, Po-cnc and Cs-cnc expression is not enriched in the labrum of either chelicerate, but instead is expressed at comparable levels in all appendages. In further contrast to mandibulate orthologs, the expression domain of Po-cnc posterior to the labrum is not confined within the expression domain of Po-Dfd. Conclusions Expression data from two chelicerate outgroup taxa suggest that the signature two-domain head expression pattern of cnc evolved at the base of Mandibulata. The observation of the archetypal labral and mandibular segment domains in a crustacean exemplar supports the synapomorphic nature of mandibulate cnc

The plutonium extraction pilot plant at Chatillon; L'usine-pilote d'extraction du plutonium de Chatillon

Energy Technology Data Exchange (ETDEWEB)

Faugeras, P; Regnault, P [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1958-07-01

After a brief recapitulation of the problem and its difficulties, the chemical process and the apparatus used are described. The results obtained at the various stages of the separation are then given, as well as the performance by the apparatus. (author) [French] Apres un bref rappel du probleme et de ses difficultes, on decrit le procede chimique et l'appareillage utilises. On donne ensuite les resultats obtenus en ce qui concerne les divers stades de la separation ainsi que les performances fournies par les appareils. (auteur)

Identification and Characterization of Linezolid-Resistant cfr-Positive Staphylococcus aureus USA300 Isolates from a New York City Medical Center

Science.gov (United States)

Zuill, Douglas E.; Scharn, Caitlyn R.; Deane, Jennifer; Sahm, Daniel F.; Goering, Richard V.; Jenkins, Stephen G.; Shaw, Karen J.

2014-01-01

The cfr gene was identified in three linezolid-resistant USA300 methicillin-resistant Staphylococcus aureus (MRSA) isolates collected over a 3-day period at a New York City medical center in 2011 as part of a routine surveillance program. Each isolate possessed a plasmid containing a pSCFS3-like cfr gene environment. Transformation of the cfr-bearing plasmids into the S. aureus ATCC 29213 background recapitulated the expected Cfr antibiogram, including resistance to linezolid, tiamulin, clindamycin, and florfenicol and susceptibility to tedizolid. PMID:25136008

Dynamic microenvironments: the fourth dimension.

Science.gov (United States)

Tibbitt, Mark W; Anseth, Kristi S

2012-11-14

The extracellular space, or cell microenvironment, choreographs cell behavior through myriad controlled signals, and aberrant cues can result in dysfunction and disease. For functional studies of human cell biology or expansion and delivery of cells for therapeutic purposes, scientists must decipher this intricate map of microenvironment biology and develop ways to mimic these functions in vitro. In this Perspective, we describe technologies for four-dimensional (4D) biology: cell-laden matrices engineered to recapitulate tissue and organ function in 3D space and over time.

Peabody's "Care of the Patient" and the Nature of Medical Science.

Science.gov (United States)

Brody, Howard

2014-01-01

Francis W. Peabody's 1927 essay "The Care of the Patient" is widely quoted, yet few appreciate the subtlety of its interweaving of medical science with its more obvious humanistic elements. Understanding the essay in context requires a recapitulation of Peabody's life story, a review of earlier work that led up to the culminating lecture in 1926, and a detailed analysis of the thread of argument Peabody wove through the lecture. A better understanding of the essay shows how Peabody anticipated several important later developments in medical thought.

Towards the future organization of the French gas industry

International Nuclear Information System (INIS)

Batail, J.

1999-01-01

This article recapitulates the content of the directive on the 'internal gas market', recalls the spirit of co-operation established with a view to developing the future gas system in France, and puts forward some to the questions raised within the framework of this co-operation. These include: public utilities, third party access to networks, the definition of future 'eligible consumers', the regulation necessary for the correct operation of the gas market on a competitive basis, and the development of French gas operators throughout the world. (author)

On the role of complexity in systems theory

CSIR Research Space (South Africa)

Greben, JM

2009-01-01

Full Text Available naturally leads to an explanation for the Big Bang and is not plagued by the horizon and cosmological constant problem. It naturally accommodates the notion of dark energy and proposes a possible explanation for dark matter. It leads to a dual description..., such as recapitulation, are also discussed. 25 March 2009 Keywords: Dark energy. Dark matter. Classical vacuum energy. Linear expansion of the universe. The role of energy conservation and vacuum energy in the evolution of the universe 2 1. Introduction In standard...

Functional Gene Discovery and Characterization of Genes and Alleles Affecting Wood Biomass Yield and Quality in Populus

Energy Technology Data Exchange (ETDEWEB)

Busov, Victor [Michigan Technological Univ., Houghton, MI (United States)

2017-02-12

Adoption of biofuels as economically and environmentally viable alternative to fossil fuels would require development of specialized bioenergy varieties. A major goal in the breeding of such varieties is the improvement of lignocellulosic biomass yield and quality. These are complex traits and understanding the underpinning molecular mechanism can assist and accelerate their improvement. This is particularly important for tree bioenergy crops like poplars (species and hybrids from the genus Populus), for which breeding progress is extremely slow due to long generation cycles. A variety of approaches have been already undertaken to better understand the molecular bases of biomass yield and quality in poplar. An obvious void in these undertakings has been the application of mutagenesis. Mutagenesis has been instrumental in the discovery and characterization of many plant traits including such that affect biomass yield and quality. In this proposal we use activation tagging to discover genes that can significantly affect biomass associated traits directly in poplar, a premier bioenergy crop. We screened a population of 5,000 independent poplar activation tagging lines under greenhouse conditions for a battery of biomass yield traits. These same plants were then analyzed for changes in wood chemistry using pyMBMS. As a result of these screens we have identified nearly 800 mutants, which are significantly (P<0.05) different when compared to wild type. Of these majority (~700) are affected in one of ten different biomass yield traits and 100 in biomass quality traits (e.g., lignin, S/G ration and C6/C5 sugars). We successfully recovered the position of the tag in approximately 130 lines, showed activation in nearly half of them and performed recapitulation experiments with 20 genes prioritized by the significance of the phenotype. Recapitulation experiments are still ongoing for many of the genes but the results are encouraging. For example, we have shown successful

Enhanced nutrient transport improves the depth-dependent properties of tri-layered engineered cartilage constructs with zonal co-culture of chondrocytes and MSCs.

Science.gov (United States)

Kim, Minwook; Farrell, Megan J; Steinberg, David R; Burdick, Jason A; Mauck, Robert L

2017-08-01

Biomimetic design in cartilage tissue engineering is a challenge given the complexity of the native tissue. While numerous studies have generated constructs with near-native bulk properties, recapitulating the depth-dependent features of native tissue remains a challenge. Furthermore, limitations in nutrient transport and matrix accumulation in engineered constructs hinders maturation within the central core of large constructs. To overcome these limitations, we fabricated tri-layered constructs that recapitulate the depth-dependent cellular organization and functional properties of native tissue using zonally derived chondrocytes co-cultured with MSCs. We also introduced porous hollow fibers (HFs) and HFs/cotton threads to enhance nutrient transport. Our results showed that tri-layered constructs with depth-dependent organization and properties could be fabricated. The addition of HFs or HFs/threads improved matrix accumulation in the central core region. With HF/threads, the local modulus in the deep region of tri-layered constructs nearly matched that of native tissue, though the properties in the central regions remained lower. These constructs reproduced the zonal organization and depth-dependent properties of native tissue, and demonstrate that a layer-by-layer fabrication scheme holds promise for the biomimetic repair of focal cartilage defects. Articular cartilage is a highly organized tissue driven by zonal heterogeneity of cells, extracellular matrix proteins and fibril orientations, resulting in depth-dependent mechanical properties. Therefore, the recapitulation of the functional properties of native cartilage in a tissue engineered construct requires such a biomimetic design of the morphological organization, and this has remained a challenge in cartilage tissue engineering. This study demonstrates that a layer-by-layer fabrication scheme, including co-cultures of zone-specific articular CHs and MSCs, can reproduce the depth-dependent characteristics

A hierarchy of time-scales and the brain.

Science.gov (United States)

Kiebel, Stefan J; Daunizeau, Jean; Friston, Karl J

2008-11-01

In this paper, we suggest that cortical anatomy recapitulates the temporal hierarchy that is inherent in the dynamics of environmental states. Many aspects of brain function can be understood in terms of a hierarchy of temporal scales at which representations of the environment evolve. The lowest level of this hierarchy corresponds to fast fluctuations associated with sensory processing, whereas the highest levels encode slow contextual changes in the environment, under which faster representations unfold. First, we describe a mathematical model that exploits the temporal structure of fast sensory input to track the slower trajectories of their underlying causes. This model of sensory encoding or perceptual inference establishes a proof of concept that slowly changing neuronal states can encode the paths or trajectories of faster sensory states. We then review empirical evidence that suggests that a temporal hierarchy is recapitulated in the macroscopic organization of the cortex. This anatomic-temporal hierarchy provides a comprehensive framework for understanding cortical function: the specific time-scale that engages a cortical area can be inferred by its location along a rostro-caudal gradient, which reflects the anatomical distance from primary sensory areas. This is most evident in the prefrontal cortex, where complex functions can be explained as operations on representations of the environment that change slowly. The framework provides predictions about, and principled constraints on, cortical structure-function relationships, which can be tested by manipulating the time-scales of sensory input.

A hierarchy of time-scales and the brain.

Directory of Open Access Journals (Sweden)

Stefan J Kiebel

2008-11-01

Full Text Available In this paper, we suggest that cortical anatomy recapitulates the temporal hierarchy that is inherent in the dynamics of environmental states. Many aspects of brain function can be understood in terms of a hierarchy of temporal scales at which representations of the environment evolve. The lowest level of this hierarchy corresponds to fast fluctuations associated with sensory processing, whereas the highest levels encode slow contextual changes in the environment, under which faster representations unfold. First, we describe a mathematical model that exploits the temporal structure of fast sensory input to track the slower trajectories of their underlying causes. This model of sensory encoding or perceptual inference establishes a proof of concept that slowly changing neuronal states can encode the paths or trajectories of faster sensory states. We then review empirical evidence that suggests that a temporal hierarchy is recapitulated in the macroscopic organization of the cortex. This anatomic-temporal hierarchy provides a comprehensive framework for understanding cortical function: the specific time-scale that engages a cortical area can be inferred by its location along a rostro-caudal gradient, which reflects the anatomical distance from primary sensory areas. This is most evident in the prefrontal cortex, where complex functions can be explained as operations on representations of the environment that change slowly. The framework provides predictions about, and principled constraints on, cortical structure-function relationships, which can be tested by manipulating the time-scales of sensory input.

Non-coding RNAs in Mesenchymal Stem Cell-Derived Extracellular Vesicles: Deciphering Regulatory Roles in Stem Cell Potency, Inflammatory Resolve, and Tissue Regeneration

Directory of Open Access Journals (Sweden)

Farah Fatima

2017-10-01

Full Text Available Extracellular vesicles (EVs are heterogeneous populations of nano- and micro-sized vesicles secreted by various cell types. There is mounting evidence that EVs have widespread roles in transporting proteins, lipids, and nucleic acids between cells and serve as mediators of intercellular communication. EVs secreted from stem cells could function as paracrine factors, and appear to mimic and recapitulate several features of their secreting cells. EV-mediated transport of regulatory RNAs provides a novel source of trans-regulation between cells. As such, stem cells have evolved unique forms of paracrine mechanisms for recapitulating their potencies with specialized functions by transporting non-coding RNAs (ncRNAs via EVs. This includes the dissemination of stem cell-derived EV-ncRNAs and their regulatory effects elicited in differentiation, self-renewal, pluripotency, and the induction of reparative programs. Here, we summarize and discuss the therapeutic effects of mesenchymal stem cell-derived EV-ncRNAs in the induction of intrinsic regenerative programs elicited through regulating several mechanisms. Among them, most noticeable are the EV-mediated enrichment of ncRNAs at the injury sites contributing the regulation of matrix remodeling, epithelial mesenchymal transitions, and attraction of fibroblasts. Additionally, we emphasize EV-mediated transmission of anti-inflammatory RNAs from stem cells to injury site that potentially orchestrate the resolution of the inflammatory responses and immune alleviation to better facilitate healing processes. Collectively, this knowledge indicates a high value and potential of EV-mediated RNA-based therapeutic approaches in regenerative medicine.

Chemotaxis in densely populated tissue determines germinal center anatomy and cell motility: a new paradigm for the development of complex tissues.

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Jared B Hawkins

Full Text Available Germinal centers (GCs are complex dynamic structures that form within lymph nodes as an essential process in the humoral immune response. They represent a paradigm for studying the regulation of cell movement in the development of complex anatomical structures. We have developed a simulation of a modified cyclic re-entry model of GC dynamics which successfully employs chemotaxis to recapitulate the anatomy of the primary follicle and the development of a mature GC, including correctly structured mantle, dark and light zones. We then show that correct single cell movement dynamics (including persistent random walk and inter-zonal crossing arise from this simulation as purely emergent properties. The major insight of our study is that chemotaxis can only achieve this when constrained by the known biological properties that cells are incompressible, exist in a densely packed environment, and must therefore compete for space. It is this interplay of chemotaxis and competition for limited space that generates all the complex and biologically accurate behaviors described here. Thus, from a single simple mechanism that is well documented in the biological literature, we can explain both higher level structure and single cell movement behaviors. To our knowledge this is the first GC model that is able to recapitulate both correctly detailed anatomy and single cell movement. This mechanism may have wide application for modeling other biological systems where cells undergo complex patterns of movement to produce defined anatomical structures with sharp tissue boundaries.

Chemotaxis in densely populated tissue determines germinal center anatomy and cell motility: a new paradigm for the development of complex tissues.

Science.gov (United States)

Hawkins, Jared B; Jones, Mark T; Plassmann, Paul E; Thorley-Lawson, David A

2011-01-01

Germinal centers (GCs) are complex dynamic structures that form within lymph nodes as an essential process in the humoral immune response. They represent a paradigm for studying the regulation of cell movement in the development of complex anatomical structures. We have developed a simulation of a modified cyclic re-entry model of GC dynamics which successfully employs chemotaxis to recapitulate the anatomy of the primary follicle and the development of a mature GC, including correctly structured mantle, dark and light zones. We then show that correct single cell movement dynamics (including persistent random walk and inter-zonal crossing) arise from this simulation as purely emergent properties. The major insight of our study is that chemotaxis can only achieve this when constrained by the known biological properties that cells are incompressible, exist in a densely packed environment, and must therefore compete for space. It is this interplay of chemotaxis and competition for limited space that generates all the complex and biologically accurate behaviors described here. Thus, from a single simple mechanism that is well documented in the biological literature, we can explain both higher level structure and single cell movement behaviors. To our knowledge this is the first GC model that is able to recapitulate both correctly detailed anatomy and single cell movement. This mechanism may have wide application for modeling other biological systems where cells undergo complex patterns of movement to produce defined anatomical structures with sharp tissue boundaries.

Glutamate and GABA in autism spectrum disorder-a translational magnetic resonance spectroscopy study in man and rodent models.

Science.gov (United States)

Horder, Jamie; Petrinovic, Marija M; Mendez, Maria A; Bruns, Andreas; Takumi, Toru; Spooren, Will; Barker, Gareth J; Künnecke, Basil; Murphy, Declan G

2018-05-25

Autism spectrum disorder (ASD) is a pervasive neurodevelopmental syndrome with a high human and economic burden. The pathophysiology of ASD is largely unclear, thus hampering development of pharmacological treatments for the core symptoms of the disorder. Abnormalities in glutamate and GABA signaling have been hypothesized to underlie ASD symptoms, and may form a therapeutic target, but it is not known whether these abnormalities are recapitulated in humans with ASD, as well as in rodent models of the disorder. We used translational proton magnetic resonance spectroscopy ([1H]MRS) to compare glutamate and GABA levels in adult humans with ASD and in a panel of six diverse rodent ASD models, encompassing genetic and environmental etiologies. [1H]MRS was performed in the striatum and the medial prefrontal cortex, of the humans, mice, and rats in order to allow for direct cross-species comparisons in specific cortical and subcortical brain regions implicated in ASD. In humans with ASD, glutamate concentration was reduced in the striatum and this was correlated with the severity of social symptoms. GABA levels were not altered in either brain region. The reduction in striatal glutamate was recapitulated in mice prenatally exposed to valproate, and in mice and rats carrying Nlgn3 mutations, but not in rodent ASD models with other etiologies. Our findings suggest that glutamate/GABA abnormalities in the corticostriatal circuitry may be a key pathological mechanism in ASD; and may be linked to alterations in the neuroligin-neurexin signaling complex.

GTP depletion synergizes the anti-proliferative activity of chemotherapeutic agents in a cell type-dependent manner

International Nuclear Information System (INIS)

Lin, Tao; Meng, Lingjun; Tsai, Robert Y.L.

2011-01-01

Highlights: → Strong synergy between mycophenolic acid (MPA) and 5-FU in MDA-MB-231 cells. → Cell type-dependent synergy between MPA and anti-proliferative agents. → The synergy of MPA on 5-FU is recapitulated by RNA polymerase-I inhibition. → The synergy of MPA on 5-FU requires the expression of nucleostemin. -- Abstract: Mycophenolic acid (MPA) depletes intracellular GTP by blocking de novo guanine nucleotide synthesis. GTP is used ubiquitously for DNA/RNA synthesis and as a signaling molecule. Here, we made a surprising discovery that the anti-proliferative activity of MPA acts synergistically with specific chemotherapeutic agents in a cell type-dependent manner. In MDA-MB-231 cells, MPA shows an extremely potent synergy with 5-FU but not with doxorubicin or etoposide. The synergy between 5-FU and MPA works most effectively against the highly tumorigenic mammary tumor cells compared to the less tumorigenic ones, and does not work in the non-breast cancer cell types that we tested, with the exception of PC3 cells. On the contrary, MPA shows the highest synergy with paclitaxel but not with 5-FU in SCC-25 cells, derived from oral squamous cell carcinomas. Mechanistically, the synergistic effect of MPA on 5-FU in MDA-MB-231 cells can be recapitulated by inhibiting the RNA polymerase-I activity and requires the expression of nucleostemin. This work reveals that the synergy between MPA and anti-proliferative agents is determined by cell type-dependent factors.

Ontogeny of the vertebral column of Eleutherodactylus johnstonei (Anura: Eleutherodactylidae) reveals heterochronies relative to metamorphic frogs.

Science.gov (United States)

Meza-Joya, Fabio Leonardo; Ramos-Pallares, Eliana Patricia; Ramírez-Pinilla, Martha Patricia

2013-07-01

Over the last century, the morphogenesis of the vertebral column has been considered as a highly conserved process among anurans. This statement is based on the study of few metamorphic taxa, ignoring the role of developmental mechanisms underlying the evolution of specialized life-histories. Direct development in anurans has been regarded as evolutionarily derived and involves developmental recapitulation and repatterning at different levels in all amphibian taxa studied so far. Herein, we analyze the vertebral column morphogenesis of the direct-developing frog Eleutherodactylus johnstonei, describing the sequence of chondrification and ossification, based on cleared and double-stained specimens from early stage embryos to adults. In general, our results show that the morphogenesis of the vertebral column in E. johnstonei recapitulates the ancestral tadpole-like pattern of development. However, the analysis of the sequence of events using heterochrony plots shows important heterocronies relative to metamorphic species, such as a delay in the chondrification of the vertebral centra and in osteogenesis. These ontogenetic peculiarities may represent derived traits in direct-developing frogs and are possibly correlated with its unusual life history. In addition, several features of the vertebral column of E. johnstonei are highly variable from its typical morphology. We report some malformations and small deviations, which do not seem to affect the survival of individuals. These anomalies have also been found in other frogs, and include many vertebral defects, such as vertebral fusion, and vertebral preclusion and/or induction. Copyright © 2013 Wiley Periodicals, Inc.

Establishment and Characterization of UTI and CAUTI in a Mouse Model.

Science.gov (United States)

Conover, Matt S; Flores-Mireles, Ana L; Hibbing, Michael E; Dodson, Karen; Hultgren, Scott J

2015-06-23

Urinary tract infections (UTI) are highly prevalent, a significant cause of morbidity and are increasingly resistant to treatment with antibiotics. Females are disproportionately afflicted by UTI: 50% of all women will have a UTI in their lifetime. Additionally, 20-40% of these women who have an initial UTI will suffer a recurrence with some suffering frequent recurrences with serious deterioration in the quality of life, pain and discomfort, disruption of daily activities, increased healthcare costs, and few treatment options other than long-term antibiotic prophylaxis. Uropathogenic Escherichia coli (UPEC) is the primary causative agent of community acquired UTI. Catheter-associated UTI (CAUTI) is the most common hospital acquired infection accounting for a million occurrences in the US annually and dramatic healthcare costs. While UPEC is also the primary cause of CAUTI, other causative agents are of increased significance including Enterococcus faecalis. Here we utilize two well-established mouse models that recapitulate many of the clinical characteristics of these human diseases. For UTI, a C3H/HeN model recapitulates many of the features of UPEC virulence observed in humans including host responses, IBC formation and filamentation. For CAUTI, a model using C57BL/6 mice, which retain catheter bladder implants, has been shown to be susceptible to E. faecalis bladder infection. These representative models are being used to gain striking new insights into the pathogenesis of UTI disease, which is leading to the development of novel therapeutics and management or prevention strategies.

TeV. The dream energy scale

International Nuclear Information System (INIS)

Murayama, Hitoshi

2006-01-01

In this talk, I'd like to explain why the TeV, 1,000,000,000,00 electron volt, is a particularly interesting energy scale in physics. I being recapitulating what particle physics is all about, citing two big questions: what the Universe is made of, and Einstein's dream of unification. TeV energy appears to be relevant to both questions, suggesting rich and complex physics at this energy. I outline how two facilities, LHC and ILC, will work together with reveal what is going on at this exciting energy scale. (author)

DNA fingerprinting in forensics: past, present, future.

Science.gov (United States)

Roewer, Lutz

2013-11-18

DNA fingerprinting, one of the great discoveries of the late 20th century, has revolutionized forensic investigations. This review briefly recapitulates 30 years of progress in forensic DNA analysis which helps to convict criminals, exonerate the wrongly accused, and identify victims of crime, disasters, and war. Current standard methods based on short tandem repeats (STRs) as well as lineage markers (Y chromosome, mitochondrial DNA) are covered and applications are illustrated by casework examples. Benefits and risks of expanding forensic DNA databases are discussed and we ask what the future holds for forensic DNA fingerprinting.

Non-conventional Energy Sources and Energy Development Strategy of Croatia

International Nuclear Information System (INIS)

Kalea, M.

2006-01-01

The distinction between unconventional renewable energy resources is elaborated. Further, general and specific properties of unconventional energy resources are concisely recapitulated; also comparison is made to conventional energy resources. Exact data are brought forth, investment and operative costs are discussed which illustrate some properties of unconventional energy resources. Overview of obligations of different countries is given as well, which derive from the EC directive on renewable energy resources. At the end, a critical view on renewable energy resources in the Strategy of energy development of Croatia is given.(author)

3D Hanging Drop Culture to Establish Prostate Cancer Organoids.

Science.gov (United States)

Eder, Theresa; Eder, Iris E

2017-01-01

Three-dimensional (3D) cell culture enables the growth of cells in a multidimensional and multicellular manner compared to conventional cell culture techniques. Especially in prostate cancer research there is a big need for more tissue-recapitulating models to get a better understanding of the mechanisms driving prostate cancer as well as to screen for more efficient drugs that can be used for treatment. In this chapter we describe a 3D hanging drop system that can be used to culture prostate cancer organoids as tumor epithelial monocultures and as epithelial-stromal cocultures.

Hepcidin- A Burgeoning Biomarker

Directory of Open Access Journals (Sweden)

Hemkant Manikrao Deshmukh

2017-10-01

Full Text Available The discovery of hepcidin has triggered a virtual ignition of studies on iron metabolism and related disorders. The peptide hormone hepcidin is a key homeostatic regulator of iron metabolism. The synthesis of hepcidin is induced by systemic iron levels and by inflammatory stimuli. Several human diseases are associated with variations in hepcidin concentrations. The evaluation of hepcidin in biological fluids is therefore a promising device in the diagnosis and management of medical situations in which iron metabolism is affected. Thus, it made us to recapitulate role of hepcidin as biomarker.

EGFR gene overexpression retained in an invasive xenograft model by solid orthotopic transplantation of human glioblastoma multiforme into nude mice.

Science.gov (United States)

Yi, Diao; Hua, Tian Xin; Lin, Huang Yan

2011-03-01

Orthotopic xenograft animal model from human glioblastoma multiforme (GBM) cell lines often do not recapitulate an extremely important aspect of invasive growth and epidermal growth factor receptor (EGFR) gene overexpression of human GBM. We developed an orthotopic xenograft model by solid transplantation of human GBM into the brain of nude mouse. The orthotopic xenografts sharing the same histopathological features with their original human GBMs were highly invasive and retained the overexpression of EGFR gene. The murine orthotopic GBM models constitute a valuable in vivo system for preclinical studies to test novel therapies for human GBM.

Orthotopic Patient-Derived Glioblastoma Xenografts in Mice.

Science.gov (United States)

Xu, Zhongye; Kader, Michael; Sen, Rajeev; Placantonakis, Dimitris G

2018-01-01

Patient-derived xenografts (PDX) provide in vivo glioblastoma (GBM) models that recapitulate actual tumors. Orthotopic tumor xenografts within the mouse brain are obtained by injection of GBM stem-like cells derived from fresh surgical specimens. These xenografts reproduce GBM's histologic complexity and hallmark biological behaviors, such as brain invasion, angiogenesis, and resistance to therapy. This method has become essential for analyzing mechanisms of tumorigenesis and testing the therapeutic effect of candidate agents in the preclinical setting. Here, we describe a protocol for establishing orthotopic tumor xenografts in the mouse brain with human GBM cells.

Loss of TET2 in hematopoietic cells leads to DNA hypermethylation of active enhancers and induction of leukemogenesis

DEFF Research Database (Denmark)

Rasmussen, Kasper D; Jia, Guangshuai; Johansen, Jens V

2015-01-01

DNA methylation is tightly regulated throughout mammalian development, and altered DNA methylation patterns are a general hallmark of cancer. The methylcytosine dioxygenase TET2 is frequently mutated in hematological disorders, including acute myeloid leukemia (AML), and has been suggested...... to protect CG dinucleotide (CpG) islands and promoters from aberrant DNA methylation. In this study, we present a novel Tet2-dependent leukemia mouse model that closely recapitulates gene expression profiles and hallmarks of human AML1-ETO-induced AML. Using this model, we show that the primary effect of Tet...

Deep learning in neural networks: an overview.

Science.gov (United States)

Schmidhuber, Jürgen

2015-01-01

In recent years, deep artificial neural networks (including recurrent ones) have won numerous contests in pattern recognition and machine learning. This historical survey compactly summarizes relevant work, much of it from the previous millennium. Shallow and Deep Learners are distinguished by the depth of their credit assignment paths, which are chains of possibly learnable, causal links between actions and effects. I review deep supervised learning (also recapitulating the history of backpropagation), unsupervised learning, reinforcement learning & evolutionary computation, and indirect search for short programs encoding deep and large networks.

Bioprinting is changing regenerative medicine forever.

Science.gov (United States)

Collins, Scott Forrest

2014-12-01

3D printing, or solid freeform fabrication, applied to regenerative medicine brings technologies from several industries together to help solve unique challenges in both basic science and tissue engineering. By more finely organizing cells and supporting structures precisely in 3D space, we will gain critical knowledge of cell-cell communications and cell-environment interactions. As we increase the scale, we will move toward complex tissue and organ structures where several cell phenotypes will functionally and structurally interact, thus recapitulating the form and function of native tissues and organs.

G.A.M.I.N., the graphite neutron detector. Development and use in the dosimetry of radio-induced damages

International Nuclear Information System (INIS)

Cance, M.; Genthon, J.P.; Salon, L.; Micaud, G.

1975-01-01

The so-called G.A.M.I.N. graphite detector is well suited to determining fluences of radiation damage in reactor materials. It enables the measurement of the index (graphite damage flux)/(nickel flux). Measurements have been performing in Osiris and most of the testing reactors in Europe (H 2 O, D 2 O, G and fast). All measurements results are recapitulated here. It is shown how G.A.M.I.N. can determine note only graphite fluxes, but by a simple interpretation the damage fluxes typical of other materials [fr

Kisspeptins: bridging energy homeostasis and reproduction

DEFF Research Database (Denmark)

Castellano, Juan M; Bentsen, Agnete H; Mikkelsen, Jens D

2010-01-01

and reproduction have been the subject of considerable attention; however, our understanding of the neurobiological basis for this phenomenon is still incomplete. In mid 1990s, the adipose-hormone, leptin, was proven as an essential signal for transmitting metabolic information onto the centers governing puberty......RH neurons. This review recapitulates the experimental evidence obtained to date, mostly in laboratory rodents, supporting the function of kisspeptins in bridging energy balance and reproduction, with special emphasis on recent developments in this field, such as the recognition of mTOR (mammalian target...

Permanent metabolic stimulation of leaves by low-dose irradiation

International Nuclear Information System (INIS)

Barabas, Z.

1979-01-01

By X-ray and colchicin treatment male-sterile mutants were produced from the Ra K9 Sorghum species. The characteristics of the mutants are compared with those of the original species. By this means the bisexual plant became unisexual, in later generations even asexual forms of reproduction were observed. This mutation chain is regarded as an artificially induced recapitulation of the natural evolution. Irradiation experiments were carried out in order to obtain wheat types resistant to brownrot, however, no success could be achieved with the present methods. (L.E.)

Adenovirus Protein E4-ORF1 activation of PI3 kinase reveals differential regulation of downstream effector pathways in adipocytes

OpenAIRE

Chaudhary, Natasha; Gonzalez, Eva; Chang, Sung-Hee; Geng, Fuqiang; Rafii, Shahin; Altorki, Nasser K.; McGraw, Timothy E.

2016-01-01

Insulin activation of phosphatidylinositol 3-kinase (PI3K) regulates metabolism, including the translocation of the Glut4 glucose transporter to the plasma membrane and inactivation of the FoxO1 transcription factor. Adenoviral protein E4-ORF1 stimulates cellular glucose metabolism by mimicking growth-factor activation of PI3K. We have used E4-ORF1 as a tool to dissect PI3K-mediated signaling in adipocytes. E4-ORF1 activation of PI3K in adipocytes recapitulates insulin regulation of FoxO1 but...

From Immunodeficiency to Humanization: The Contribution of Mouse Models to Explore HTLV-1 Leukemogenesis

Directory of Open Access Journals (Sweden)

Eléonore Pérès

2015-12-01

Full Text Available The first discovered human retrovirus, Human T-Lymphotropic Virus type 1 (HTLV-1, is responsible for an aggressive form of T cell leukemia/lymphoma. Mouse models recapitulating the leukemogenesis process have been helpful for understanding the mechanisms underlying the pathogenesis of this retroviral-induced disease. This review will focus on the recent advances in the generation of immunodeficient and human hemato-lymphoid system mice with a particular emphasis on the development of mouse models for HTLV-1-mediated pathogenesis, their present limitations and the challenges yet to be addressed.

Clock force. Universe, time, and future

International Nuclear Information System (INIS)

Karb, W.

2005-01-01

In a dialog full of esprite two protagonists of the sides of physics and philosophy struggle about answers on great questions. As witnesses occur the great phsicists and philosophers, the theories and discoveries of them Karb recapitulates in easily understandable form and puts together into relation. Karb advertizes for pragmatic and responsible ethics in the sciences. Always within the great theories themselves Karb argumentates that theoretical physics is indeed not at the end, but it should have an end with always new billions expensive collider facilities, which serve lonely for the hybris of scientists

Trends in domestic violence service and leadership: implications for an integrated shelter model.

Science.gov (United States)

Panzer, P G; Philip, M B; Hayward, R A

2000-05-01

Domestic violence is a dangerous and prevalent social problem affecting up to 4 million women and countless children annually. Shelters offer safety and an opportunity for change during the crisis of family violence. These individuals also have the potential for retraumatization if leadership within the program recapitulates the abuse and coercion felt at home. This article reviews three related trends through the lens of power and control--domestic violence policy and service, models of leadership, and the study of traumatic stress disorders and recovery--and describes their implications for modern shelter service delivery.

Cardiomyocytes Derived From Pluripotent Stem Cells Recapitulate Electrophysiological Characteristics of an Overlap Syndrome of Cardiac Sodium Channel Disease

NARCIS (Netherlands)

Davis, Richard P.; Casini, Simona; van den Berg, Cathelijne W.; Hoekstra, Maaike; Remme, Carol Ann; Dambrot, Cheryl; Salvatori, Daniela; Ward-van Oostwaard, Dorien; Wilde, Arthur A. M.; Bezzina, Connie R.; Verkerk, Arie O.; Freund, Christian; Mummery, Christine L.

2012-01-01

Background-Pluripotent stem cells (PSCs) offer a new paradigm for modeling genetic cardiac diseases, but it is unclear whether mouse and human PSCs can truly model both gain-and loss-of-function genetic disorders affecting the Na+ current (I-Na) because of the immaturity of the PSC-derived

Early increase and late decrease of purkinje cell dendritic spine density in prion-infected organotypic mouse cerebellar cultures.

Science.gov (United States)

Campeau, Jody L; Wu, Gengshu; Bell, John R; Rasmussen, Jay; Sim, Valerie L

2013-01-01

Prion diseases are infectious neurodegenerative diseases associated with the accumulation of protease-resistant prion protein, neuronal loss, spongiform change and astrogliosis. In the mouse model, the loss of dendritic spines is one of the earliest pathological changes observed in vivo, occurring 4-5 weeks after the first detection of protease-resistant prion protein in the brain. While there are cell culture models of prion infection, most do not recapitulate the neuropathology seen in vivo. Only the recently developed prion organotypic slice culture assay has been reported to undergo neuronal loss and the development of some aspects of prion pathology, namely small vacuolar degeneration and tubulovesicular bodies. Given the rapid replication of prions in this system, with protease-resistant prion protein detectable by 21 days, we investigated whether the dendritic spine loss and altered dendritic morphology seen in prion disease might also develop within the lifetime of this culture system. Indeed, six weeks after first detection of protease-resistant prion protein in tga20 mouse cerebellar slice cultures infected with RML prion strain, we found a statistically significant loss of Purkinje cell dendritic spines and altered dendritic morphology in infected cultures, analogous to that seen in vivo. In addition, we found a transient but statistically significant increase in Purkinje cell dendritic spine density during infection, at the time when protease-resistant prion protein was first detectable in culture. Our findings support the use of this slice culture system as one which recapitulates prion disease pathology and one which may facilitate study of the earliest stages of prion disease pathogenesis.

Gene Correction Reverses Ciliopathy and Photoreceptor Loss in iPSC-Derived Retinal Organoids from Retinitis Pigmentosa Patients

Directory of Open Access Journals (Sweden)

Wen-Li Deng

2018-04-01

Full Text Available Summary: Retinitis pigmentosa (RP is an irreversible, inherited retinopathy in which early-onset nyctalopia is observed. Despite the genetic heterogeneity of RP, RPGR mutations are the most common causes of this disease. Here, we generated induced pluripotent stem cells (iPSCs from three RP patients with different frameshift mutations in the RPGR gene, which were then differentiated into retinal pigment epithelium (RPE cells and well-structured retinal organoids possessing electrophysiological properties. We observed significant defects in photoreceptor in terms of morphology, localization, transcriptional profiling, and electrophysiological activity. Furthermore, shorted cilium was found in patient iPSCs, RPE cells, and three-dimensional retinal organoids. CRISPR-Cas9-mediated correction of RPGR mutation rescued photoreceptor structure and electrophysiological property, reversed the observed ciliopathy, and restored gene expression to a level in accordance with that in the control using transcriptome-based analysis. This study recapitulated the pathogenesis of RPGR using patient-specific organoids and achieved targeted gene therapy of RPGR mutations in a dish as proof-of-concept evidence. : Jin and colleagues demonstrate that patient-specific iPSC-derived 3D retinae can recapitulate disease progress of retinitis pigmentosa through presenting defects in photoreceptor morphology, gene profile, and electrophysiology, as well as the defective ciliogenesis in iPSCs, iPSC-RPE, and 3D retinae. CRISPR/Cas9-mediated gene correction can rescue not only photoreceptor structure and electrophysiological property but also observed ciliopathy. Keywords: RPGR, photoreceptor, electrophysiology, retinitis pigmentosa, patient-derived iPSCs, retinal organoid, RPE cells, cilium, ciliopathy, disease modeling

Focus on Extracellular Vesicles: Therapeutic Potential of Stem Cell-Derived Extracellular Vesicles

Directory of Open Access Journals (Sweden)

Bin Zhang

2016-02-01

Full Text Available The intense research focus on stem and progenitor cells could be attributed to their differentiation potential to generate new cells to replace diseased or lost cells in many highly intractable degenerative diseases, such as Alzheimer disease, multiple sclerosis, and heart diseases. However, experimental and clinical studies have increasingly attributed the therapeutic efficacy of these cells to their secretion. While stem and progenitor cells secreted many therapeutic molecules, none of these molecules singly or in combination could recapitulate the functional effects of stem cell transplantations. Recently, it was reported that extracellular vesicles (EVs could recapitulate the therapeutic effects of stem cell transplantation. Based on the observations reported thus far, the prevailing hypothesis is that stem cell EVs exert their therapeutic effects by transferring biologically active molecules such as proteins, lipids, mRNA, and microRNA from the stem cells to injured or diseased cells. In this respect, stem cell EVs are similar to EVs from other cell types. They are both primarily vehicles for intercellular communication. Therefore, the differentiating factor is likely due to the composition of their cargo. The cargo of EVs from different cell types are known to include a common set of proteins and also proteins that reflect the cell source of the EVs and the physiological or pathological state of the cell source. Hence, elucidation of the stem cell EV cargo would provide an insight into the multiple physiological or biochemical changes necessary to affect the many reported stem cell-based therapeutic outcomes in a variety of experimental models and clinical trials.

A reproducible brain tumour model established from human glioblastoma biopsies

International Nuclear Information System (INIS)

Wang, Jian; Chekenya, Martha; Bjerkvig, Rolf; Enger, Per Ø; Miletic, Hrvoje; Sakariassen, Per Ø; Huszthy, Peter C; Jacobsen, Hege; Brekkå, Narve; Li, Xingang; Zhao, Peng; Mørk, Sverre

2009-01-01

Establishing clinically relevant animal models of glioblastoma multiforme (GBM) remains a challenge, and many commonly used cell line-based models do not recapitulate the invasive growth patterns of patient GBMs. Previously, we have reported the formation of highly invasive tumour xenografts in nude rats from human GBMs. However, implementing tumour models based on primary tissue requires that these models can be sufficiently standardised with consistently high take rates. In this work, we collected data on growth kinetics from a material of 29 biopsies xenografted in nude rats, and characterised this model with an emphasis on neuropathological and radiological features. The tumour take rate for xenografted GBM biopsies were 96% and remained close to 100% at subsequent passages in vivo, whereas only one of four lower grade tumours engrafted. Average time from transplantation to the onset of symptoms was 125 days ± 11.5 SEM. Histologically, the primary xenografts recapitulated the invasive features of the parent tumours while endothelial cell proliferations and necrosis were mostly absent. After 4-5 in vivo passages, the tumours became more vascular with necrotic areas, but also appeared more circumscribed. MRI typically revealed changes related to tumour growth, several months prior to the onset of symptoms. In vivo passaging of patient GBM biopsies produced tumours representative of the patient tumours, with high take rates and a reproducible disease course. The model provides combinations of angiogenic and invasive phenotypes and represents a good alternative to in vitro propagated cell lines for dissecting mechanisms of brain tumour progression

A reproducible brain tumour model established from human glioblastoma biopsies

Directory of Open Access Journals (Sweden)

Li Xingang

2009-12-01

Full Text Available Abstract Background Establishing clinically relevant animal models of glioblastoma multiforme (GBM remains a challenge, and many commonly used cell line-based models do not recapitulate the invasive growth patterns of patient GBMs. Previously, we have reported the formation of highly invasive tumour xenografts in nude rats from human GBMs. However, implementing tumour models based on primary tissue requires that these models can be sufficiently standardised with consistently high take rates. Methods In this work, we collected data on growth kinetics from a material of 29 biopsies xenografted in nude rats, and characterised this model with an emphasis on neuropathological and radiological features. Results The tumour take rate for xenografted GBM biopsies were 96% and remained close to 100% at subsequent passages in vivo, whereas only one of four lower grade tumours engrafted. Average time from transplantation to the onset of symptoms was 125 days ± 11.5 SEM. Histologically, the primary xenografts recapitulated the invasive features of the parent tumours while endothelial cell proliferations and necrosis were mostly absent. After 4-5 in vivo passages, the tumours became more vascular with necrotic areas, but also appeared more circumscribed. MRI typically revealed changes related to tumour growth, several months prior to the onset of symptoms. Conclusions In vivo passaging of patient GBM biopsies produced tumours representative of the patient tumours, with high take rates and a reproducible disease course. The model provides combinations of angiogenic and invasive phenotypes and represents a good alternative to in vitro propagated cell lines for dissecting mechanisms of brain tumour progression.

Following the genes: a framework for animal modeling of psychiatric disorders

LENUS (Irish Health Repository)

Mitchell, Kevin

2011-11-11

Abstract The number of individual cases of psychiatric disorders that can be ascribed to identified, rare, single mutations is increasing with great rapidity. Such mutations can be recapitulated in mice to generate animal models with direct etiological validity. Defining the underlying pathogenic mechanisms will require an experimental and theoretical framework to make the links from mutation to altered behavior in an animal or psychopathology in a human. Here, we discuss key elements of such a framework, including cell type-based phenotyping, developmental trajectories, linking circuit properties at micro and macro scales and definition of neurobiological phenotypes that are directly translatable to humans.

Bioreactor engineering of stem cell environments.

Science.gov (United States)

Tandon, Nina; Marolt, Darja; Cimetta, Elisa; Vunjak-Novakovic, Gordana

2013-11-15

Stem cells hold promise to revolutionize modern medicine by the development of new therapies, disease models and drug screening systems. Standard cell culture systems have limited biological relevance because they do not recapitulate the complex 3-dimensional interactions and biophysical cues that characterize the in vivo environment. In this review, we discuss the current advances in engineering stem cell environments using novel biomaterials and bioreactor technologies. We also reflect on the challenges the field is currently facing with regard to the translation of stem cell based therapies into the clinic. Copyright © 2013 Elsevier Inc. All rights reserved.

Metallurgy of continuous filamentary A15 superconductors

International Nuclear Information System (INIS)

Suenaga, M.

1980-01-01

The early history of the bronze process is recapitulated and modifications to the process which have since followed are described. The metallurgical principles, which are involved in the process, are described including the kinetics of the compound growth, the effects of additives on the growth, etc. The superconducting properties of these compounds are also discussed. The influence of metallurgical variables on the superconducting properties is discussed in detail. In discussing the superconducting current densities in these compounds, limits in applicability of existing magnetic-flux-pinning models are also treated as well as methods for determining critical magnetic fields

A geologic guide to Wrangell-Saint Elias National Park and Preserve, Alaska; a tectonic collage of northbound terranes

Science.gov (United States)

Winkler, Gary R.; with contributions by MacKevett, E. M.; Plafker, George; Richter, D.H.; Rosenkrans, D.S.; Schmoll, H.R.

2000-01-01

Wrangell-Saint Elias National Park and Preserve, the largest unit in the U.S. National Park System, encompasses near 13.2 million acres of geological wonderments. This geologic guide presents history of exploration and Earth-science investigation; describes the complex geologic makeup; characterizes the vast college of accretion geologic terranes in this area of Alaska's continental margin; recapitulates the effects of earthquakes, volcanoes, and glaciers; characterizes the copper and gold resources of the parklands; and describes outstanding locales within the park and preserve area. A glossary of geologic terms and a categorized list of additional sources of information complete this report.

Creating biomaterials with spatially organized functionality.

Science.gov (United States)

Chow, Lesley W; Fischer, Jacob F

2016-05-01

Biomaterials for tissue engineering provide scaffolds to support cells and guide tissue regeneration. Despite significant advances in biomaterials design and fabrication techniques, engineered tissue constructs remain functionally inferior to native tissues. This is largely due to the inability to recreate the complex and dynamic hierarchical organization of the extracellular matrix components, which is intimately linked to a tissue's biological function. This review discusses current state-of-the-art strategies to control the spatial presentation of physical and biochemical cues within a biomaterial to recapitulate native tissue organization and function. © 2016 by the Society for Experimental Biology and Medicine.

Text-analytic Measurement of Effectuation and Causation Orientations among Small and Global Business Managers

DEFF Research Database (Denmark)

Mattsson, Jan; Helmersson, Helge

2012-01-01

We demonstrate how one can measure overall quality in texts gathered from interviews by means of PERTEX text analytic method. We compare text analytic measures and content for locally active Scandinavian small business managers and globally operating Indian IT managers when recapitulating......-components we are also able to display the degree of fragmentation, focus and integration in the text. We show how AFFI measures differ between managers with a causation or effectuation orientation irrespective of their role as small business manager or as an established global manager. Hence, we posit...... that effectuation and causation orientations may be generic characteristic of managers in general....

SDCCAG8 interacts with rab effector proteins rabep2 and erc1 and is required for hedgehog signaling

DEFF Research Database (Denmark)

Airik, Rannar; Schueler, M.; Airik, M.

2016-01-01

Recessive mutations in the SDCCAG8 gene cause a nephronophthisis-related ciliopathy with Bardet-Biedl syndrome-like features in humans. Our previous characterization of the orthologous Sdccag8gt/gt mouse model recapitulated the retinal-renal disease phenotypes and identified impaired DNA damage......1), and with non-muscle myosin motor proteins (MYH9, MYH10, MYH14) at the centrosome. Furthermore, we show that RABEP2 localization at the centrosome is regulated by SDCCAG8. siRNA mediated RABEP2 knockdown in hTERT-RPE1 cells leads to defective ciliogenesis, indicating a critical role for RABEP2...

A designated centre for people with disabilities operated by Health Service Executive, Westmeath

LENUS (Irish Health Repository)

Mitchell, Kevin

2011-11-11

Abstract The number of individual cases of psychiatric disorders that can be ascribed to identified, rare, single mutations is increasing with great rapidity. Such mutations can be recapitulated in mice to generate animal models with direct etiological validity. Defining the underlying pathogenic mechanisms will require an experimental and theoretical framework to make the links from mutation to altered behavior in an animal or psychopathology in a human. Here, we discuss key elements of such a framework, including cell type-based phenotyping, developmental trajectories, linking circuit properties at micro and macro scales and definition of neurobiological phenotypes that are directly translatable to humans.

Reenacting the birth of an intron

Energy Technology Data Exchange (ETDEWEB)

Hellsten, Uffe; Aspden, Julie L.; Rio, Donald C.; Rokhsar, Daniel S.

2011-07-01

An intron is an extended genomic feature whose function requires multiple constrained positions - donor and acceptor splice sites, a branch point, a polypyrimidine tract and suitable splicing enhancers - that may be distributed over hundreds or thousands of nucleotides. New introns are therefore unlikely to emerge by incremental accumulation of functional sub-elements. Here we demonstrate that a functional intron can be created de novo in a single step by a segmental genomic duplication. This experiment recapitulates in vivo the birth of an intron that arose in the ancestral jawed vertebrate lineage nearly half a billion years ago.

The Unicellular State as a Point Source in a Quantum Biological System

Directory of Open Access Journals (Sweden)

John S. Torday

2016-05-01

Full Text Available A point source is the central and most important point or place for any group of cohering phenomena. Evolutionary development presumes that biological processes are sequentially linked, but neither directed from, nor centralized within, any specific biologic structure or stage. However, such an epigenomic entity exists and its transforming effects can be understood through the obligatory recapitulation of all eukaryotic lifeforms through a zygotic unicellular phase. This requisite biological conjunction can now be properly assessed as the focal point of reconciliation between biology and quantum phenomena, illustrated by deconvoluting complex physiologic traits back to their unicellular origins.

Laurel Lodge Nursing Home, Templemichael Glebe, Longford.

LENUS (Irish Health Repository)

Mitchell, Kevin

2011-11-11

Abstract The number of individual cases of psychiatric disorders that can be ascribed to identified, rare, single mutations is increasing with great rapidity. Such mutations can be recapitulated in mice to generate animal models with direct etiological validity. Defining the underlying pathogenic mechanisms will require an experimental and theoretical framework to make the links from mutation to altered behavior in an animal or psychopathology in a human. Here, we discuss key elements of such a framework, including cell type-based phenotyping, developmental trajectories, linking circuit properties at micro and macro scales and definition of neurobiological phenotypes that are directly translatable to humans.

The development of the breeder reactor program of the German Federal Republic

International Nuclear Information System (INIS)

Haunschild, H.H.

1984-01-01

This article recapitulates the stages of the program which is in hand in the German Federal Republic concerning breeder reactors with fast neutrons. In particular, it describes in detail the causes for the delays in the construction of the demonstration reactor SRN 300 (Kalkar) for which the commissioning has now been fixed for 1987. It emphasizes the importance of the collaboration which exists in Europe for the establishment of the projects and the construction of fast neutron power stations, including the SNR 2 reactor; the construction of the latter could begin in the German Federal Republic at the end of the Eighties [fr

SORM applied to hierarchical parallel system

DEFF Research Database (Denmark)

Ditlevsen, Ove Dalager

2006-01-01

of a particular first order reliability method (FORM) was first described in a celebrated paper by Rackwitz and Fiessler more than a quarter of a century ago. The method has become known as the Rackwitz-Fiessler algorithm. The original RF-algorithm as applied to a hierarchical random variable model...... is recapitulated so that a simple but quite effective accuracy improving calculation can be explained. A limit state curvature correction factor on the probability approximation is obtained from the final stop results of the RF-algorithm. This correction factor is based on Breitung’s asymptotic formula for second...

Zebrafish: swimming towards a role for fanconi genes in DNA repair.

Science.gov (United States)

Scata, Kimberly A; El-Deiry, Wafik S

2004-06-01

The zebrafish, Danio rerio, has become a favorite model organism for geneticists and developmental biologists. Recently cancer biologists have turned to this tiny fish to help them unravel the mysteries of conserved pathways such as the Fanconi Anemia (FA) pathway. Although a relatively rare disease, the genes involved in FA are part of a large network of DNA damage response/repair genes. Liu and colleagues have recapitulated some of the clinical manifestations of human FA by knocking down the zebrafish FANC-D2 gene thereby providing a new model for probing the underlying causes of these phenotypes.

Human Embryonic Stem Cells: A Model for the Study of Neural Development and Neurological Diseases

Directory of Open Access Journals (Sweden)

Piya Prajumwongs

2016-01-01

Full Text Available Although the mechanism of neurogenesis has been well documented in other organisms, there might be fundamental differences between human and those species referring to species-specific context. Based on principles learned from other systems, it is found that the signaling pathways required for neural induction and specification of human embryonic stem cells (hESCs recapitulated those in the early embryo development in vivo at certain degree. This underscores the usefulness of hESCs in understanding early human neural development and reinforces the need to integrate the principles of developmental biology and hESC biology for an efficient neural differentiation.

Energy, metals and ores in France in 1983

International Nuclear Information System (INIS)

Anon.

1984-01-01

Every year the Annales des Mines devote one issue to the activities of the power producing and mineral industries. This issue refers to the year 1983, with a recapitulation of previous years. A first part describes the activity of the following principal sectors. Energy: solid mineral fuel, hydrocarbons, gas, electricity, uranium, geothermal power. Ores and metals: aluminium, antimony, silver, chromium, copper, tin, iron, manganese, nickel, gold, lead, tungsten, zinc. Nonmetallic substances: barite, phosphate, potash, salt, sulphur, fluorspar. The elements concern mainly France but they are presented in a world-wide context. A second part gives statistical items, completed and illustrated by diagrams [fr

Energy, metals and ores in France in 1982

International Nuclear Information System (INIS)

Anon.

1983-01-01

Every year the Annales des Mines devote one issue to the activities of the power producing and mineral industries. This issue refers to the year 1982, with a recapitulation of previous years. A first part describes the activity of the following principal sectors. Energy: solid mineral fuel, hydrocarbons, gas, electricity, uranium, geothermal power. Ores and metals: aluminium, antimony, silver, chromium, copper, tin, iron, manganese, nickel, gold, lead, tungsten, zinc. Nonmetallic substances: barite, phosphate, potash, salt, sulphur, fluorspar. The elements concern mainly France but they are presented in a world-wide context. A second part gives statistical items, completed and illustrated by diagrams [fr

Occupational Medicine Relevant to Aviation Medicine, Conference Proceedings of the Aerospace Medical Panel Symposium Held at London on 4 October 1983.

Science.gov (United States)

1984-05-01

vivant . Sur comaande de la Direction des Recherches Etudes et Techniques (D.R.E.T.), le Centre d’Etudes et de Recherches de Mdecine Aerospatiale a...17000 51000 100 5.56 15 60 34.0 0.2 17000 78000 100 8.33 12.5 Tableau I - Bois de peuplier : recapitulation des rssultats. V (°C/mn) Pi (g) Pf (g) CO...60 30.0 (3.7) 10500 19500 35950 4400 15 100 5.56 1 Tableau II - PVC r6capitulation des rtsultats. (°C/mn) Pi (g) Pf (g) CO maxi CO2 maxi HCN maxi C3H8

Energy policy of the International Energy Agency (IEA) countries. General review of the year 1990

International Nuclear Information System (INIS)

1992-01-01

This book is a general review on energy policy leaded by Members countries of International Energy Agency (IEA) during the year 1990. This book describes also the trends and the recent events which have affected energy demand, energy conservation, energy efficiency, energy supply and energy source development. This annual review gives the IEA energy forecasting for the next years, till year 2001. A detailed study of energy policy in Federal Republic of Germany, Austria, Denmark, Greece, Ireland and Japan is given. The policy of fifteen another Members countries, which have been analyzed the previous years, is recapitulated and briefly brought up to date

A designated centre for people with disabilities operated by Camphill Communities of Ireland, Kilkenny

LENUS (Irish Health Repository)

Mitchell, Kevin

2011-11-11

Abstract The number of individual cases of psychiatric disorders that can be ascribed to identified, rare, single mutations is increasing with great rapidity. Such mutations can be recapitulated in mice to generate animal models with direct etiological validity. Defining the underlying pathogenic mechanisms will require an experimental and theoretical framework to make the links from mutation to altered behavior in an animal or psychopathology in a human. Here, we discuss key elements of such a framework, including cell type-based phenotyping, developmental trajectories, linking circuit properties at micro and macro scales and definition of neurobiological phenotypes that are directly translatable to humans.

Progress in Development of Improved Ion-Channel Biosensors

Science.gov (United States)

Nadeau, Jay L.; White, Victor E.; Maurer, Joshua A.; Dougherty, Dennis A.

2008-01-01

Further improvements have recently been made in the development of the devices described in Improved Ion-Channel Biosensors (NPO-30710), NASA Tech Briefs, Vol. 28, No. 10 (October 2004), page 30. As discussed in more detail in that article, these sensors offer advantages of greater stability, greater lifetime, and individual electrical addressability, relative to prior ion-channel biosensors. In order to give meaning to a brief description of the recent improvements, it is necessary to recapitulate a substantial portion of the text of the cited previous article. The figure depicts one sensor that incorporates the recent improvements, and can be helpful in understanding the recapitulated text, which follows: These sensors are microfabricated from silicon and other materials compatible with silicon. Typically, the sensors are fabricated in arrays in silicon wafers on glass plates. Each sensor in the array can be individually electrically addressed, without interference with its neighbors. Each sensor includes a well covered by a thin layer of silicon nitride, in which is made a pinhole for the formation of a lipid bilayer membrane. In one stage of fabrication, the lower half of the well is filled with agarose, which is allowed to harden. Then the upper half of the well is filled with a liquid electrolyte (which thereafter remains liquid) and a lipid bilayer is painted over the pinhole. The liquid contains a protein that forms an ion channel on top of the hardened agarose. The combination of enclosure in the well and support by the hardened agarose provides the stability needed to keep the membrane functional for times as long as days or even weeks. An electrode above the well, another electrode below the well, and all the materials between the electrodes together constitute a capacitor. What is measured is the capacitive transient current in response to an applied voltage pulse. One notable feature of this sensor, in comparison with prior such sensors, is a

A mouse model for fucosidosis recapitulates storage pathology and neurological features of the milder form of the human disease

Directory of Open Access Journals (Sweden)

Heike Wolf

2016-09-01

Full Text Available Fucosidosis is a rare lysosomal storage disorder caused by the inherited deficiency of the lysosomal hydrolase α-L-fucosidase, which leads to an impaired degradation of fucosylated glycoconjugates. Here, we report the generation of a fucosidosis mouse model, in which the gene for lysosomal α-L-fucosidase (Fuca1 was disrupted by gene targeting. Homozygous knockout mice completely lack α-L-fucosidase activity in all tested organs leading to highly elevated amounts of the core-fucosylated glycoasparagine Fuc(α1,6-GlcNAc(β1-N-Asn and, to a lesser extent, other fucosylated glycoasparagines, which all were also partially excreted in urine. Lysosomal storage pathology was observed in many visceral organs, such as in the liver, kidney, spleen and bladder, as well as in the central nervous system (CNS. On the cellular level, storage was characterized by membrane-limited cytoplasmic vacuoles primarily containing water-soluble storage material. In the CNS, cellular alterations included enlargement of the lysosomal compartment in various cell types, accumulation of secondary storage material and neuroinflammation, as well as a progressive loss of Purkinje cells combined with astrogliosis leading to psychomotor and memory deficits. Our results demonstrate that this new fucosidosis mouse model resembles the human disease and thus will help to unravel underlying pathological processes. Moreover, this model could be utilized to establish diagnostic and therapeutic strategies for fucosidosis.

Phylogeographical Analysis on Squalidus argentatus Recapitulates Historical Landscapes and Drainage Evolution on the Island of Taiwan and Mainland China

Directory of Open Access Journals (Sweden)

Hung-Du Lin

2012-01-01

Full Text Available Phylogeographical analyses on Squalidus argentatus samples from thirteen localities within mainland China and Taiwan were conducted for biogeographic studies, as their dispersal strictly depends on geological evolution of the landmasses. A total of 95 haplotypes were genotyped for mtDNA cyt b gene in 160 specimens from nine river systems. Relatively high levels of haplotype diversity (h = 0.984 and low levels of nucleotide diversity (π = 0.020 were detected in S. argentatus. Two major phylogenetic haplotype groups, A and B, were revealed via phylogenetic analysis. The degree of intergroup divergence (3.96% indicates that these groups diverged about 4.55 myr (million years ago. Haplotype network and population analyses indicated significant genetic structure (FST = 0.775, largely concordant with the geographical location of the populations. According to SAMOVA analysis, we divided these populations into four units: Yangtze-Pearl, Qiantang-Minjiang, Jiulong-Beijiang and Taiwan groups. Mismatch distribution analysis, neutrality tests and Bayesian skyline plots indicated a significant population expansion for lineage A and B, approximately dated 0.35 and 0.04 myr ago, respectively. We found strong geographical organization of the haplotype clades across different geographic scales that can be explained by episodes of dispersal and population expansion followed by population fragmentation and restricted gene flow.

Newly-derived neuroblastoma cell lines propagated in serum-free media recapitulate the genotype and phenotype of primary neuroblastoma tumours.

Science.gov (United States)

Bate-Eya, Laurel T; Ebus, Marli E; Koster, Jan; den Hartog, Ilona J M; Zwijnenburg, Danny A; Schild, Linda; van der Ploeg, Ida; Dolman, M Emmy M; Caron, Huib N; Versteeg, Rogier; Molenaar, Jan J

2014-02-01

Recently protocols have been devised for the culturing of cell lines from fresh tumours under serum-free conditions in defined neural stem cell medium. These cells, frequently called tumour initiating cells (TICs) closely retained characteristics of the tumours of origin. We report the isolation of eight newly-derived neuroblastoma TICs from six primary neuroblastoma tumours and two bone marrow metastases. The primary tumours from which these TICs were generated have previously been fully typed by whole genome sequencing (WGS). Array comparative genomic hybridisation (aCGH) analysis showed that TIC lines retained essential characteristics of the primary tumours and exhibited typical neuroblastoma chromosomal aberrations such as MYCN amplification, gain of chromosome 17q and deletion of 1p36. Protein analysis showed expression for neuroblastoma markers MYCN, NCAM, CHGA, DBH and TH while haematopoietic markers CD19 and CD11b were absent. We analysed the growth characteristics and confirmed tumour-forming potential using sphere-forming assays, subcutaneous and orthotopic injection of these cells into immune-compromised mice. Affymetrix mRNA expression profiling of TIC line xenografts showed an expression pattern more closely mimicking primary tumours compared to xenografts from classical cell lines. This establishes that these neuroblastoma TICs cultured under serum-free conditions are relevant and useful neuroblastoma tumour models. Copyright © 2013 Elsevier Ltd. All rights reserved.

Carcinogen-Induced Hepatic Tumors in KLF6+/- Mice Recapitulate Aggressive Human Hepatocellular Carcinoma Associated with p53 Pathway Deregulation

NARCIS (Netherlands)

Tarocchi, Mirko; Hannivoort, Rebekka; Hoshida, Yujin; Lee, Ursula E.; Vetter, Diana; Narla, Goutham; Villanueva, Augusto; Oren, Moshe; Llovet, Josep M.; Friedman, Scott L.

Inactivation of KLF6 is common in hepatocellular carcinoma (HCC) associated with hepatitis C virus (HCV) infection, thereby abrogating its normal antiproliferative activity in liver cells. The aim of the study was to evaluate the impact of KLF6 depletion on human HCC and experimental

A mouse model for fucosidosis recapitulates storage pathology and neurological features of the milder form of the human disease

DEFF Research Database (Denmark)

Wolf, Heike; Damme, Markus; Stroobants, Stijn

2016-01-01

Fucosidosis is a rare lysosomal storage disorder caused by the inherited deficiency of the lysosomal hydrolase α-L-fucosidase, which leads to an impaired degradation of fucosylated glycoconjugates. Here we report the generation of a fucosidosis mouse model, in which the gene for lysosomal α-L-fuc...

An allosteric gating model recapitulates the biophysical properties of IK,L expressed in mouse vestibular type I hair cells.

Science.gov (United States)

Spaiardi, Paolo; Tavazzani, Elisa; Manca, Marco; Milesi, Veronica; Russo, Giancarlo; Prigioni, Ivo; Marcotti, Walter; Magistretti, Jacopo; Masetto, Sergio

2017-11-01

Vestibular type I and type II hair cells and their afferent fibres send information to the brain regarding the position and movement of the head. The characteristic feature of type I hair cells is the expression of a low-voltage-activated outward rectifying K + current, I K,L , whose biophysical properties and molecular identity are still largely unknown. In vitro, the afferent nerve calyx surrounding type I hair cells causes unstable intercellular K + concentrations, altering the biophysical properties of I K,L . We found that in the absence of the calyx, I K,L in type I hair cells exhibited unique biophysical activation properties, which were faithfully reproduced by an allosteric channel gating scheme. These results form the basis for a molecular and pharmacological identification of I K,L . Type I and type II hair cells are the sensory receptors of the mammalian vestibular epithelia. Type I hair cells are characterized by their basolateral membrane being enveloped in a single large afferent nerve terminal, named the calyx, and by the expression of a low-voltage-activated outward rectifying K + current, I K,L . The biophysical properties and molecular profile of I K,L are still largely unknown. By using the patch-clamp whole-cell technique, we examined the voltage- and time-dependent properties of I K,L in type I hair cells of the mouse semicircular canal. We found that the biophysical properties of I K,L were affected by an unstable K + equilibrium potential (V eq K + ). Both the outward and inward K + currents shifted V eq K + consistent with K + accumulation or depletion, respectively, in the extracellular space, which we attributed to a residual calyx attached to the basolateral membrane of the hair cells. We therefore optimized the hair cell dissociation protocol in order to isolate mature type I hair cells without their calyx. In these cells, the uncontaminated I K,L showed a half-activation at -79.6 mV and a steep voltage dependence (2.8 mV). I K,L also showed complex activation and deactivation kinetics, which we faithfully reproduced by an allosteric channel gating scheme where the channel is able to open from all (five) closed states. The 'early' open states substantially contribute to I K,L activation at negative voltages. This study provides the first complete description of the 'native' biophysical properties of I K,L in adult mouse vestibular type I hair cells. © 2017 The Authors. The Journal of Physiology published by John Wiley & Sons Ltd on behalf of The Physiological Society.

Newly-derived neuroblastoma cell lines propagated in serum-free media recapitulate the genotype and phenotype of primary neuroblastoma tumours

NARCIS (Netherlands)

Bate-Eya, Laurel T.; Ebus, Marli E.; Koster, Jan; den Hartog, Ilona J. M.; Zwijnenburg, Danny A.; Schild, Linda; van der Ploeg, Ida; Dolman, M. Emmy M.; Caron, Huib N.; Versteeg, Rogier; Molenaar, Jan J.

2014-01-01

Recently protocols have been devised for the culturing of cell lines from fresh tumours under serum-free conditions in defined neural stem cell medium. These cells, frequently called tumour initiating cells (TICs) closely retained characteristics of the tumours of origin. We report the isolation of

The complete mitochondrial genome of the common sea slater, Ligia oceanica (Crustacea, Isopoda bears a novel gene order and unusual control region features

Directory of Open Access Journals (Sweden)

Podsiadlowski Lars

2006-09-01

Full Text Available Abstract Background Sequence data and other characters from mitochondrial genomes (gene translocations, secondary structure of RNA molecules are useful in phylogenetic studies among metazoan animals from population to phylum level. Moreover, the comparison of complete mitochondrial sequences gives valuable information about the evolution of small genomes, e.g. about different mechanisms of gene translocation, gene duplication and gene loss, or concerning nucleotide frequency biases. The Peracarida (gammarids, isopods, etc. comprise about 21,000 species of crustaceans, living in many environments from deep sea floor to arid terrestrial habitats. Ligia oceanica is a terrestrial isopod living at rocky seashores of the european North Sea and Atlantic coastlines. Results The study reveals the first complete mitochondrial DNA sequence from a peracarid crustacean. The mitochondrial genome of Ligia oceanica is a circular double-stranded DNA molecule, with a size of 15,289 bp. It shows several changes in mitochondrial gene order compared to other crustacean species. An overview about mitochondrial gene order of all crustacean taxa yet sequenced is also presented. The largest non-coding part (the putative mitochondrial control region of the mitochondrial genome of Ligia oceanica is unexpectedly not AT-rich compared to the remainder of the genome. It bears two repeat regions (4× 10 bp and 3× 64 bp, and a GC-rich hairpin-like secondary structure. Some of the transfer RNAs show secondary structures which derive from the usual cloverleaf pattern. While some tRNA genes are putative targets for RNA editing, trnR could not be localized at all. Conclusion Gene order is not conserved among Peracarida, not even among isopods. The two isopod species Ligia oceanica and Idotea baltica show a similarly derived gene order, compared to the arthropod ground pattern and to the amphipod Parhyale hawaiiensis, suggesting that most of the translocation events were already

Generation and characterization of gsuα:EGFP transgenic zebrafish for evaluating endocrine-disrupting effects

International Nuclear Information System (INIS)

Cheng, Xiaoxia; Chen, Xiaowen; Jin, Xia; He, Jiangyan; Yin, Zhan

2014-01-01

The glycoprotein subunit α (gsuα) gene encodes the shared α subunit of the three pituitary heterodimeric glycoprotein hormones: follicle-stimulating hormone β (Fshβ), luteinizing hormone β (Lhβ) and thyroid stimulating hormone β (Tshβ). In our current study, we identified and characterized the promoter region of zebrafish gsuα and generated a stable gsuα:EGFP transgenic line, which recapitulated the endogenous gsuα expression in the early developing pituitary gland. A relatively conserved regulatory element set is presented in the promoter regions of zebrafish and three other known mammalian gsuα promoters. Our results also demonstrated that the expression patterns of the gsuα:EGFP transgene were all identical to those expression patterns of the endogenous gsuα expression in the pituitary tissue when our transgenic fish were treated with various endocrine chemicals, including forskolin (FSK), SP600125, trichostatin A (TSA), KClO 4 , dexamethasone (Dex), β-estradiol and progesterone. Thus, this gsuα:EGFP transgenic fish reporter line provides another valuable tool for investigating the lineage development of gsuα-expressing gonadotrophins and the coordinated regulation of various glycoprotein hormone subunit genes. These reporter fish can serve as a novel platform to perform screenings of endocrine-disrupting chemicals (EDCs) in vivo as well. - Highlights: • Identification of the promoter of zebrafish glycoprotein subunit α (gsuα) gene • Generation of stable transmission gsuα:EGFP transgenic zebrafish reporter • Demonstration of the recapitulation of the gsuα:EGFP and endogenous gsuα expression • Suggestion of the gsuα:EGFP transgenic zebrafish as a novel platform for EDC study

Generation and characterization of gsuα:EGFP transgenic zebrafish for evaluating endocrine-disrupting effects

Energy Technology Data Exchange (ETDEWEB)

Cheng, Xiaoxia [Key Laboratory of Aquatic Biodiversity and Conservation of the Chinese Academy of Sciences, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, Hubei (China); University of Chinese Academy of Sciences, Beijing (China); Chen, Xiaowen; Jin, Xia; He, Jiangyan [Key Laboratory of Aquatic Biodiversity and Conservation of the Chinese Academy of Sciences, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, Hubei (China); Yin, Zhan, E-mail: zyin@ihb.ac.cn [Key Laboratory of Aquatic Biodiversity and Conservation of the Chinese Academy of Sciences, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, Hubei (China); Ningbo Laboratory, State Key Laboratory of Freshwater Ecology and Biotechnology (China)

2014-07-01

The glycoprotein subunit α (gsuα) gene encodes the shared α subunit of the three pituitary heterodimeric glycoprotein hormones: follicle-stimulating hormone β (Fshβ), luteinizing hormone β (Lhβ) and thyroid stimulating hormone β (Tshβ). In our current study, we identified and characterized the promoter region of zebrafish gsuα and generated a stable gsuα:EGFP transgenic line, which recapitulated the endogenous gsuα expression in the early developing pituitary gland. A relatively conserved regulatory element set is presented in the promoter regions of zebrafish and three other known mammalian gsuα promoters. Our results also demonstrated that the expression patterns of the gsuα:EGFP transgene were all identical to those expression patterns of the endogenous gsuα expression in the pituitary tissue when our transgenic fish were treated with various endocrine chemicals, including forskolin (FSK), SP600125, trichostatin A (TSA), KClO{sub 4}, dexamethasone (Dex), β-estradiol and progesterone. Thus, this gsuα:EGFP transgenic fish reporter line provides another valuable tool for investigating the lineage development of gsuα-expressing gonadotrophins and the coordinated regulation of various glycoprotein hormone subunit genes. These reporter fish can serve as a novel platform to perform screenings of endocrine-disrupting chemicals (EDCs) in vivo as well. - Highlights: • Identification of the promoter of zebrafish glycoprotein subunit α (gsuα) gene • Generation of stable transmission gsuα:EGFP transgenic zebrafish reporter • Demonstration of the recapitulation of the gsuα:EGFP and endogenous gsuα expression • Suggestion of the gsuα:EGFP transgenic zebrafish as a novel platform for EDC study.

Loss of spastin function results in disease-specific axonal defects in human pluripotent stem cell-based models of hereditary spastic paraplegia

Science.gov (United States)

Denton, Kyle R.; Lei, Ling; Grenier, Jeremy; Rodionov, Vladimir; Blackstone, Craig; Li, Xue-Jun

2013-01-01

Human neuronal models of hereditary spastic paraplegias (HSP) that recapitulate disease-specific axonal pathology hold the key to understanding why certain axons degenerate in patients and to developing therapies. SPG4, the most common form of HSP, is caused by autosomal dominant mutations in the SPAST gene, which encodes the microtubule-severing ATPase spastin. Here, we have generated a human neuronal model of SPG4 by establishing induced pluripotent stem cells (iPSCs) from an SPG4 patient and differentiating these cells into telencephalic glutamatergic neurons. The SPG4 neurons displayed a significant increase in axonal swellings, which stained strongly for mitochondria and tau, indicating the accumulation of axonal transport cargoes. In addition, mitochondrial transport was decreased in SPG4 neurons, revealing that these patient iPSC-derived neurons recapitulate disease-specific axonal phenotypes. Interestingly, spastin protein levels were significantly decreased in SPG4 neurons, supporting a haploinsufficiency mechanism. Furthermore, cortical neurons derived from spastin-knockdown human embryonic stem cells (hESCs) exhibited similar axonal swellings, confirming that the axonal defects can be caused by loss of spastin function. These spastin-knockdown hESCs serve as an additional model for studying HSP. Finally, levels of stabilized acetylated-tubulin were significantly increased in SPG4 neurons. Vinblastine, a microtubule-destabilizing drug, rescued this axonal swelling phenotype in neurons derived from both SPG4 iPSCs and spastin-knockdown hESCs. Thus, this study demonstrates the successful establishment of human pluripotent stem cell-based neuronal models of SPG4, which will be valuable for dissecting the pathogenic cellular mechanisms and screening compounds to rescue the axonal degeneration in HSP. PMID:24123785

Covalent immobilization of stem cell factor and stromal derived factor 1α for in vitro culture of hematopoietic progenitor cells.

Science.gov (United States)

Cuchiara, Maude L; Horter, Kelsey L; Banda, Omar A; West, Jennifer L

2013-12-01

Hematopoietic stem cells (HSCs) are currently utilized in the treatment of blood diseases, but widespread application of HSC therapeutics has been hindered by the limited availability of HSCs. With a better understanding of the HSC microenvironment and the ability to precisely recapitulate its components, we may be able to gain control of HSC behavior. In this work we developed a novel, biomimetic PEG hydrogel material as a substrate for this purpose and tested its potential with an anchorage-independent hematopoietic cell line, 32D clone 3 cells. We immobilized a fibronectin-derived adhesive peptide sequence, RGDS; a cytokine critical in HSC self-renewal, stem cell factor (SCF); and a chemokine important in HSC homing and lodging, stromal derived factor 1α (SDF1α), onto the surfaces of poly(ethylene glycol) (PEG) hydrogels. To evaluate the system's capabilities, we observed the effects of the biomolecules on 32D cell adhesion and morphology. We demonstrated that the incorporation of RGDS onto the surfaces promotes 32D cell adhesion in a dose-dependent fashion. We also observed an additive response in adhesion on surfaces with RGDS in combination with either SCF or SDF1α. In addition, the average cell area increased and circularity decreased on gel surfaces containing immobilized SCF or SDF1α, indicating enhanced cell spreading. By recapitulating aspects of the HSC microenvironment using a PEG hydrogel scaffold, we have shown the ability to control the adhesion and spreading of the 32D cells and demonstrated the potential of the system for the culture of primary hematopoietic cell populations. Copyright © 2013 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Formal language theory: refining the Chomsky hierarchy

Science.gov (United States)

Jäger, Gerhard; Rogers, James

2012-01-01

The first part of this article gives a brief overview of the four levels of the Chomsky hierarchy, with a special emphasis on context-free and regular languages. It then recapitulates the arguments why neither regular nor context-free grammar is sufficiently expressive to capture all phenomena in the natural language syntax. In the second part, two refinements of the Chomsky hierarchy are reviewed, which are both relevant to the extant research in cognitive science: the mildly context-sensitive languages (which are located between context-free and context-sensitive languages), and the sub-regular hierarchy (which distinguishes several levels of complexity within the class of regular languages). PMID:22688632

Generation of BAC transgenic epithelial organoids.

Directory of Open Access Journals (Sweden)

Gerald Schwank

Full Text Available Under previously developed culture conditions, mouse and human intestinal epithelia can be cultured and expanded over long periods. These so-called organoids recapitulate the three-dimensional architecture of the gut epithelium, and consist of all major intestinal cell types. One key advantage of these ex vivo cultures is their accessibility to live imaging. So far the establishment of transgenic fluorescent reporter organoids has required the generation of transgenic mice, a laborious and time-consuming process, which cannot be extended to human cultures. Here we present a transfection protocol that enables the generation of recombinant mouse and human reporter organoids using BAC (bacterial artificial chromosome technology.

Building a better model of cancer

Directory of Open Access Journals (Sweden)

DeGregori James

2006-10-01

Full Text Available Abstract The 2006 Cold Spring Harbor Laboratory meeting on the Mechanisms and Models of Cancer was held August 16–20. The meeting featured several hundred presentations of many short talks (mostly selected from the abstracts and posters, with the airing of a number of exciting new discoveries. We will focus this meeting review on models of cancer (primarily mouse models, highlighting recent advances in new mouse models that better recapitulate sporadic tumorigenesis, demonstrations of tumor addiction to tumor suppressor inactivation, new insight into senescence as a tumor barrier, improved understanding of the evolutionary paths of cancer development, and environmental/immunological influences on cancer.

Bioprinted three dimensional human tissues for toxicology and disease modeling.

Science.gov (United States)

Nguyen, Deborah G; Pentoney, Stephen L

2017-03-01

The high rate of attrition among clinical-stage therapies, due largely to an inability to predict human toxicity and/or efficacy, underscores the need for in vitro models that better recapitulate in vivo human biology. In much the same way that additive manufacturing has revolutionized the production of solid objects, three-dimensional (3D) bioprinting is enabling the automated production of more architecturally and functionally accurate in vitro tissue culture models. Here, we provide an overview of the most commonly used bioprinting approaches and how they are being used to generate complex in vitro tissues for use in toxicology and disease modeling research. Copyright © 2017 Elsevier Ltd. All rights reserved.

Formal language theory: refining the Chomsky hierarchy.

Science.gov (United States)

Jäger, Gerhard; Rogers, James

2012-07-19

The first part of this article gives a brief overview of the four levels of the Chomsky hierarchy, with a special emphasis on context-free and regular languages. It then recapitulates the arguments why neither regular nor context-free grammar is sufficiently expressive to capture all phenomena in the natural language syntax. In the second part, two refinements of the Chomsky hierarchy are reviewed, which are both relevant to the extant research in cognitive science: the mildly context-sensitive languages (which are located between context-free and context-sensitive languages), and the sub-regular hierarchy (which distinguishes several levels of complexity within the class of regular languages).

Ground rules of the pluripotency gene regulatory network.

KAUST Repository

Li, Mo

2017-01-03

Pluripotency is a state that exists transiently in the early embryo and, remarkably, can be recapitulated in vitro by deriving embryonic stem cells or by reprogramming somatic cells to become induced pluripotent stem cells. The state of pluripotency, which is stabilized by an interconnected network of pluripotency-associated genes, integrates external signals and exerts control over the decision between self-renewal and differentiation at the transcriptional, post-transcriptional and epigenetic levels. Recent evidence of alternative pluripotency states indicates the regulatory flexibility of this network. Insights into the underlying principles of the pluripotency network may provide unprecedented opportunities for studying development and for regenerative medicine.

Following the genes: a framework for animal modeling of psychiatric disorders

Directory of Open Access Journals (Sweden)

Sawa Akira

2011-11-01

Full Text Available Abstract The number of individual cases of psychiatric disorders that can be ascribed to identified, rare, single mutations is increasing with great rapidity. Such mutations can be recapitulated in mice to generate animal models with direct etiological validity. Defining the underlying pathogenic mechanisms will require an experimental and theoretical framework to make the links from mutation to altered behavior in an animal or psychopathology in a human. Here, we discuss key elements of such a framework, including cell type-based phenotyping, developmental trajectories, linking circuit properties at micro and macro scales and definition of neurobiological phenotypes that are directly translatable to humans.

A program to develop advanced EBT [ELMO Bumpy Torus] concepts and international collaboration on the Bumpy Torus concept: Final report

International Nuclear Information System (INIS)

1987-01-01

This project was undertaken to develop innovative concepts for improving the performance of ELMO Bumpy Torus devices in those aspects of plasma confinement that are particularly relevant to an eventual EBT reactor concept. These include effective magnetic utilization using Andreoletti coils, enhanced confinement using positive ambipolar potentials, and attractive divertor concepts that are compatible with formation and maintenance of ELMO rings. Each of the three major objectives was achieved and, except for the divertor studies, documented for publication and presentation at major scientific meetings. This report provides a brief recapitulation of the major results achieved in the form of a collection of those publications, together with this Introduction

W-Tagging/B-Veto in SUSY search for squarks and gluinos in final states with missing transverse energy, jets, and one isolated lepton at ATLAS

CERN Document Server

Reyer, Max

2015-01-01

This report recapitulates my stay at CERN as a Summer Student in a 13-week period from June 29 to September 25 in 2015. During that time, I was part of the CERN ATLAS Supersymmetry working group and working on a project exploiting W-tagging and B-veto techniques for the search for squarks and gluinos in final states with missing transverse energy, jets, and one isolated lepton. In this report, I will summarize my project and present results and conclusions. Apart from that, I will also write about my experience with the Summer Student lectures, the social aspects and the CERN Summer School in general.

Ground rules of the pluripotency gene regulatory network.

KAUST Repository

Li, Mo; Belmonte, Juan Carlos Izpisua

2017-01-01

Pluripotency is a state that exists transiently in the early embryo and, remarkably, can be recapitulated in vitro by deriving embryonic stem cells or by reprogramming somatic cells to become induced pluripotent stem cells. The state of pluripotency, which is stabilized by an interconnected network of pluripotency-associated genes, integrates external signals and exerts control over the decision between self-renewal and differentiation at the transcriptional, post-transcriptional and epigenetic levels. Recent evidence of alternative pluripotency states indicates the regulatory flexibility of this network. Insights into the underlying principles of the pluripotency network may provide unprecedented opportunities for studying development and for regenerative medicine.

Regenerative endodontics: barriers and strategies for clinical translation.

Science.gov (United States)

Mao, Jeremy J; Kim, Sahng G; Zhou, Jian; Ye, Ling; Cho, Shoko; Suzuki, Takahiro; Fu, Susan Y; Yang, Rujing; Zhou, Xuedong

2012-07-01

Regenerative endodontics has encountered substantial challenges toward clinical translation. The adoption by the American Dental Association of evoked pulp bleeding in immature permanent teeth is an important step for regenerative endodontics. However, there is no regenerative therapy for most endodontic diseases. Simple recapitulation of cell therapy and tissue engineering strategies that are under development for other organ systems has not led to clinical translation in regeneration endodontics. Recent work using novel biomaterial scaffolds and growth factors that orchestrate the homing of host endogenous cells represents a departure from traditional cell transplantation approaches and may accelerate clinical translation. Copyright © 2012 Elsevier Inc. All rights reserved.

New lessons learned from disease modeling with induced Pluripotent Stem Cells

Science.gov (United States)

Onder, Tamer T.; Daley, George Q.

2012-01-01

Cellular reprogramming and generation of induced pluripotent stem cells (iPSCs) from adult cell types has enabled the creation of patient-specific stem cells for use in disease modeling. To date, many iPSC lines have been generated from a variety of disorders, which have then been differentiated into disease-relevant cell types. When a disease-specific phenotype is detectable in such differentiated cells, the reprogramming technology provides a new opportunity to identify aberrant disease-associated pathways and drugs that can block them. Here, we highlight recent progress as well as limitations in the use of iPSCs to recapitulate disease phenotypes and to screen for therapeutics in vitro. PMID:22749051

A bio-inspired spatial patterning circuit.

Science.gov (United States)

Chen, Kai-Yuan; Joe, Danial J; Shealy, James B; Land, Bruce R; Shen, Xiling

2014-01-01

Lateral Inhibition (LI) is a widely conserved patterning mechanism in biological systems across species. Distinct from better-known Turing patterns, LI depend on cell-cell contact rather than diffusion. We built an in silico genetic circuit model to analyze the dynamic properties of LI. The model revealed that LI amplifies differences between neighboring cells to push them into opposite states, hence forming stable 2-D patterns. Inspired by this insight, we designed and implemented an electronic circuit that recapitulates LI patterning dynamics. This biomimetic system serve as a physical model to elucidate the design principle of generating robust patterning through spatial feedback, regardless of the underlying devices being biological or electrical.

Spiral phases of doped antiferromagnets

International Nuclear Information System (INIS)

Shraiman, B.I.; Siggia, E.D.

1990-01-01

The dipole density field describing the holls in a doped antiferromagnet is considered for law hole density in the semiclassical limit. This yields a phase in which the order parameter is planar and spirals round a fixed direction. The single spiral state breaks the continuous spin rotational symmetry and exhibits long-range order at zero temperature. In it there is a global spin direction as rotation axis. The double spiral state, in which there are two perpendicular directions, is isotropic in both spin and real space. Several results of microscopic calculations, carried out to understand the electronic states, quantum fluctuations, lattice effects and normal mode dynamics, are recapitulated. 8 refs

Risk Acceptance Criteria and/or Decision optimization

DEFF Research Database (Denmark)

Ditlevsen, Ove Dalager

1996-01-01

Acceptance criteria applied in practical risk analysis are recapitulated including the concept of rist profile. Modelling of risk profiles is illustrated on the basis of compound Poisson process models. The current practice of authoritative acceptance criteria formulation is discussed from...... a decision theoretical point of view. It is argued that the phenomenon of risk aversion rather than being of concern to the authority should be of concern to the owner. Finally it is discussed whether there is an ethical problem when formally capitalising human lives with a positive interest rate. Keywords......: Risk acceptance, Risk profile, Compound Poisson model for risk profile, Capitalization of human life, Risk aversion....

RSV-Induced H3K4 Demethylase KDM5B Leads to Regulation of Dendritic Cell-Derived Innate Cytokines and Exacerbates Pathogenesis In Vivo

DEFF Research Database (Denmark)

Ptaschinski, Catherine; Mukherjee, Sumanta; Moore, Martin L

2015-01-01

-transfected cells. The generation of Kdm5bfl/fl-CD11c-Cre+ mice recapitulated the latter results during in vitro DC activation showing innate cytokine modulation. In vivo, infection of Kdm5bfl/fl-CD11c-Cre+ mice with RSV resulted in higher production of IFN-γ and reduced IL-4 and IL-5 compared to littermate....../fl-CD11c-CRE mice were used, the exacerbated response was abrogated. Importantly, human monocyte-derived DCs treated with a chemical inhibitor for KDM5B resulted in increased innate cytokine levels as well as elicited decreased Th2 cytokines when co-cultured with RSV reactivated CD4+ T cells...

Ways out of the environmental crisis

International Nuclear Information System (INIS)

Irrgang, B.; Klawitter, J.; Seif, K.P.

1987-01-01

The book documents the interdisciplinary papers held at a meeting on 'Ways out of the environmental crisis' in November 1985. Guided by the principle of concrete responsibilities emphasis was on the following subjects: Time presses - definition and consequences of the awareness of an imminent environmental catastrophe; air pollution and water pollution recapitulated; economic strategies for the benefit of pollution abatement; ethical and theological aspects; acceptable environmental policies - prospects and perspectives. The papers reflect the relation between the environment, the present generation, posterity, gross national producns and energy consumption, and present a number of scientifically founded alternative strategies. (HSCH) With 16 figs., 1 tab [de

Proceedings of CAS - CERN Accelerator School: Course on Superconductivity for Accelerators

Energy Technology Data Exchange (ETDEWEB)

Bailey, R [European Organization for Nuclear Research, Geneva (Switzerland)

2014-07-01

These proceedings collate lectures given at the twenty-seventh specialized course organised by the CERN Accelerator School (CAS). The course was held at the Ettore Majorana Foundation and Centre for Scientific Culture (EMFCSC) in Erice, Italy, from 24 April to 4 May 2013. Following recapitulation lectures on basic accelerator physics and superconductivity, the course covered topics related to the design, production and operation of superconducting RF systems and superconducting magnets for accelerators. The participants pursued one of six case studies in order to get ’hands-on’ experience of the issues connected with the design of superconducting systems. A series of topical seminars completed the programme.

Purification and final concentration of the plutonium obtained by treatment of irradiated uranium at the Fontenay-aux-Roses pilot plant; Purification et concentration finales du plutonium en fin de traitement de l'uranium irradie a l'usine-pilote de Fontenay-aux-Roses

Energy Technology Data Exchange (ETDEWEB)

Prevot, I; Corpel, J; Regnaut, P [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1958-07-01

This paper consists of: 1- a recapitulation of the laboratory tests which led to the choice of the method; 2- a description of the latter, with the results obtained at the Fontenay-aux-Roses pilot plant; 3- the analytical methods used for checking and verifying the purity of the plutonium. (author)Fren. [French] Cet expose comprend: 1- le rappel des essais de laboratoire qui ont conduit au choix du procede; 2- la description de ce dernier, avec les resultats obtenus a l'Usine-Pilote de Fontenay-aux-Roses; 3- les methodes analytiques utilisees pour le controle et pour la verification de la purete du plutonium. (auteur)

Experimental cancer cachexia: Evolving strategies for getting closer to the human scenario.

Science.gov (United States)

Penna, Fabio; Busquets, Sílvia; Argilés, Josep M

2016-06-01

Cancer cachexia is a frequent syndrome that dramatically affects patient quality of life, anti-cancer treatment effectiveness, and overall survival. To date, no effective treatment is available and most of the studies are performed in experimental models in order to uncover the underlying mechanisms and to design prospective therapeutic strategies. This review summarizes the most relevant information regarding the use of animal models for studying cancer cachexia. Technical limitations and degree of recapitulation of the features of human cachexia are highlighted, in order to help investigators choose the most suitable model according to study-specific endpoints. Copyright © 2015 Elsevier Ltd. All rights reserved.

On endogenous order of moves in a trade embargo game

International Nuclear Information System (INIS)

Ngueyen Manh Hung

1991-01-01

Hung and Quyen's model (analysis of strategic interactions between players in the game theoretic framework) is first recapitulated. Solutions to the embargo game with the seller acting as the Stackelberg leader in both periods. Then the timing coordination issue is discussed and perfect equilibrium outcomes under different structures of leader-follower in the game are compared. Numerical simulations show that the structure corresponding to alternated leadership from one period to the other yields the perfect equilibrium outcome that is Pareto improving with respect to the structure where the buyer is first mover in both periods and Pareto dominant for some specific values of the parameters embedded in the game

A systematic review on in vitro 3D bone metastases models: A new horizon to recapitulate the native clinical scenario?

Science.gov (United States)

Salamanna, Francesca; Contartese, Deyanira; Maglio, Melania; Fini, Milena

2016-07-12

While the skeleton is not the only organ where metastasis can occur, it is one of the preferred sites, with a significant impact in patients' quality of life. With the aim of delineating the cellular and molecular mechanisms of bone metastasis, numerous studies have been employed to identify any contributing factors that trigger cancer progression. One of the major limitations of studying cancer-bone metastasis is the multifaceted nature of the native bone environment and the lack of reliable, simple, and not expensive models that strictly mimic the biological processes occurring in vivo allowing a correct translation of results. Currently, with the growing acceptance of in vitro models as effective tools for studying cancer biology, three-dimensional (3D) models have emerged as a compromise between two-dimensional cultures of isolated cancer cells and the complexity of human cancer xenografts in immunocompromised animal hosts. This descriptive systematic literature review summarizes the current status of advanced and alternative 3D in vitro bone metastases models. We have also reviewed the strategies employed by researchers to set-up these models with special reference to recent promising developments trying to better replicate the complexity and heterogeneity of a human metastasis in situ, with an outlook at their use in medicine. All these aspects will greatly contribute to the existing knowledge on bone metastases, providing a specific link to clinical scenarios and thus making 3D in vitro bone metastasis models an attractive tool for multidisciplinary experts.

Histological evidence of oxidative stress and premature senescence in preterm premature rupture of the human fetal membranes recapitulated in vitro.

Science.gov (United States)

Menon, Ramkumar; Boldogh, Istvan; Hawkins, Hal K; Woodson, Michael; Polettini, Jossimara; Syed, Tariq Ali; Fortunato, Stephen J; Saade, George R; Papaconstantinou, John; Taylor, Robert N

2014-06-01

Preterm prelabor rupture of the membranes (pPROM) may lead to preterm births (PTBs). We investigated premature senescence of fetal membranes in women with pPROM and spontaneous PTB with intact membranes (PTBs, and term births. Term fetal membranes were exposed to cigarette smoke extract to induce oxidative stress. Western blots documented p-p53 and p-p38 MAPK. Transmission electron microscopy assessed cellular morphologic features in clinical and cigarette smoke extract-treated membranes. A total of 80% of pPROM cells and >60% of term cells were positive for all three senescence phenotype markers, and concentrations were higher than in PTBs (P PTBs. Histologic and biochemical resemblance of pPROM and term membranes suggests premature senescence of the membranes is a mechanistic feature in pPROM, and this can be phenocopied in an in vitro model. Copyright © 2014 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

Craniosynostosis of coronal suture in Twist1+/- mice occurs through endochondral ossification recapitulating the physiological closure of posterior frontal suture

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Bjorn eBehr

2011-07-01

Full Text Available Craniosynostosis, the premature closure of cranial suture, is a pathologic condition that affects 1/2000 live births. Saethre-Chotzen syndrome is a genetic condition characterized by craniosynostosis. The Saethre-Chotzen syndrome, which is defined by loss-of-function mutations in the TWIST gene, is the second most prevalent craniosynostosis. Although much of the genetics and phenotypes in craniosynostosis syndromes is understood, less is known about the underlying ossification mechanism during suture closure. We have previously demonstrated that physiological closure of the posterior frontal (PF suture occurs through endochondral ossification. Moreover, we revealed that antagonizing canonical Wnt signaling in the sagittal suture leads to endochondral ossification of the suture mesenchyme and sagittal synostosis, presumably by inhibiting Twist1. Classic Saethre-Chotzen syndrome is characterized by coronal synostosis, and the haploinsufficient Twist1+/- mice represents a suitable model for studying this syndrome. Thus, we seeked to understand the underlying ossification process in coronal craniosynostosis in Twist1+/- mice. Our data indicate that coronal suture closure in Twist1+/- mice occurs between postnatal day 9 to 13 by endochondral ossification, as shown by histology, gene expression analysis and immunohistochemistry. In conclusion, this study reveals that coronal craniosynostosis in Twist1+/- mice occurs through endochondral ossification. Moreover, it suggests that haploinsufficency of Twist1 gene, a target of canonical Wnt-signaling, and inhibitor of chondrogenesis, mimics conditions of inactive canonical Wnt-signaling leading to craniosynostosis.

Zebrafish mutants in the von Hippel-Lindau tumor suppressor display a hypoxic response and recapitulate key aspects of Chuvash polycythemia

NARCIS (Netherlands)

van Rooijen, E.; Voest, E.E.; Logister, I.; Korving, J.; Schwerte, T.; Schulte-Merker, S.; Giles, R.H.; van Eeden, F.J.

2009-01-01

We have generated 2 zebrafish lines carrying inactivating germline mutations in the von Hippel-Lindau (VHL) tumor suppressor gene ortholog vhl. Mutant embryos display a general systemic hypoxic response, including the up-regulation of hypoxia-induced genes by 1 day after fertilization and a severe

Allometric scaling and cell ratios in multi-organ in vitro models of human metabolism

Directory of Open Access Journals (Sweden)

Nadia eUcciferri

2014-12-01

Full Text Available Intelligent in vitro models able to recapitulate the physiological interactions between tissues in the body have enormous potential as they enable detailed studies on specific two-way or higher order tissue communication. These models are the first step towards building an integrated picture of systemic metabolism and signalling in physiological or pathological conditions. However the rational design of in vitro models of cell-cell or cell-tissue interaction is difficult as quite often cell culture experiments are driven by the device used, rather than by design considerations. Indeed very little research has been carried out on in vitro models of metabolism connecting different cell or tissue types in a physiologically and metabolically relevant manner. Here we analyse the physiologic relationship between cells, cell metabolism and exchange in the human body using allometric rules, downscaling them to an organ-on-a plate device. In particular, in order to establish appropriate cell ratios in the system in a rational manner, two different allometric scaling models (Cell Number Scaling Model, CNSM, and Metabolic and Surface Scaling model, MSSM are proposed and applied to a two compartment model of hepatic-vascular metabolic cross-talk. The theoretical scaling studies illustrate that the design and hence relevance of multi-organ models is principally determined by experimental constraints. Two experimentally feasible model configurations are then implemented in a multi-compartment organ-on-a plate device. An analysis of the metabolic response of the two configurations demonstrates that their glucose and lipid balance is quite different, with only one of the two models recapitulating physiological-like homeostasis. In conclusion, not only do cross-talk and physical stimuli play an important role in in vitro models, but the numeric relationship between cells is also crucial to recreate in vitro interactions which can be extrapolated to the in vivo

Patient-Specific Human Induced Pluripotent Stem Cell Model Assessed with Electrical Pacing Validates S107 as a Potential Therapeutic Agent for Catecholaminergic Polymorphic Ventricular Tachycardia.

Directory of Open Access Journals (Sweden)

Kenichi Sasaki

Full Text Available Human induced pluripotent stem cells (hiPSCs offer a unique opportunity for disease modeling. However, it is not invariably successful to recapitulate the disease phenotype because of the immaturity of hiPSC-derived cardiomyocytes (hiPSC-CMs. The purpose of this study was to establish and analyze iPSC-based model of catecholaminergic polymorphic ventricular tachycardia (CPVT, which is characterized by adrenergically mediated lethal arrhythmias, more precisely using electrical pacing that could promote the development of new pharmacotherapies.We generated hiPSCs from a 37-year-old CPVT patient and differentiated them into cardiomyocytes. Under spontaneous beating conditions, no significant difference was found in the timing irregularity of spontaneous Ca2+ transients between control- and CPVT-hiPSC-CMs. Using Ca2+ imaging at 1 Hz electrical field stimulation, isoproterenol induced an abnormal diastolic Ca2+ increase more frequently in CPVT- than in control-hiPSC-CMs (control 12% vs. CPVT 43%, p<0.05. Action potential recordings of spontaneous beating hiPSC-CMs revealed no significant difference in the frequency of delayed afterdepolarizations (DADs between control and CPVT cells. After isoproterenol application with pacing at 1 Hz, 87.5% of CPVT-hiPSC-CMs developed DADs, compared to 30% of control-hiPSC-CMs (p<0.05. Pre-incubation with 10 μM S107, which stabilizes the closed state of the ryanodine receptor 2, significantly decreased the percentage of CPVT-hiPSC-CMs presenting DADs to 25% (p<0.05.We recapitulated the electrophysiological features of CPVT-derived hiPSC-CMs using electrical pacing. The development of DADs in the presence of isoproterenol was significantly suppressed by S107. Our model provides a promising platform to study disease mechanisms and screen drugs.

BIBLICAL MOTIFS IN THE UNDERSTANDING THE MANUSCRIPTS OF A SCRIBE FROM PECHORA I. S. MYANDIN

Directory of Open Access Journals (Sweden)

Tatyana Fedorovna Volkova

2014-11-01

Full Text Available The paper off ers a survey of manuscripts of a peasant, Old Believer and knizhnik I. S. Miandin (1823–1894, Ust’-Tsilma, Komi Republic from the Old Manuscript Division of the IRLI (Institute of Russian Literature of the Russian Academy of Science or Pushkinskiy Dom. Knizhnik, in the Russian tradition, is a scribe, who also can recite from memory the Scripture texts and the patristic tradition. Miandin left his recapitulations of the Old Believers literary tradition. He left few compilations, transcribed a number of Old Russian texts of various genres. In four convolutes, he collected Biblical stories taken from chronographs. Most of Miandin’s stories recapitulate the Old Testament texts, but there are also legends from the early Christian history (e. g., The Story of Emperor Constantine and His Mother Helen. His major source was, in all probability, the copy of the Chronograph from the Old Believers tradition which he had in his possession (he lent it to a writer S. V. Maksimov and never received it back. The whereabouts of the Chronographer are not known. Some of the stories were signifi cantly reworked by Miandin in comparison with the chronographic version. Among those the are the stories of Joseph the Beautiful, King Solomon and Judith. Th e study of Miandin’s manuscripts demosntrates that the fi rst stage of his work is refl ected in the IRLI reduction (Ust’-Tsil’ma collection #267, the second – idem, #66, the third – RNB NSRK О.100. The Biblical protagonists were interpreted according to the understanding of life by Pechora peasants. The peripeteias were taken with empathy as if they were concerned people next-door. This attitude compelled the narrator to seek, from one version to another, the most convincing motivations for the action of the heroes.

Chronic ingestion of 2-deoxy-D-glucose induces cardiac vacuolization and increases mortality in rats

International Nuclear Information System (INIS)

Minor, Robin K.; Smith, Daniel L.; Sossong, Alex M.; Kaushik, Susmita; Poosala, Suresh; Spangler, Edward L.; Roth, George S.; Lane, Mark; Allison, David B.; Cabo, Rafael de; Ingram, Donald K.; Mattison, Julie A.

2010-01-01

Calorie restriction (CR), the purposeful reduction of energy intake with maintenance of adequate micronutrient intake, is well known to extend the lifespan of laboratory animals. Compounds like 2-deoxy-D-glucose (2DG) that can recapitulate the metabolic effects of CR are of great interest for their potential to extend lifespan. 2DG treatment has been shown to have potential therapeutic benefits for treating cancer and seizures. 2DG has also recapitulated some hallmarks of the CR phenotype including reduced body temperature and circulating insulin in short-term rodent trials, but one chronic feeding study in rats found toxic effects. The present studies were performed to further explore the long-term effects of 2DG in vivo. First we demonstrate that 2DG increases mortality of male Fischer-344 rats. Increased incidence of pheochromocytoma in the adrenal medulla was also noted in the 2DG treated rats. We reconfirm the cardiotoxicity of 2DG in a 6-week follow-up study evaluating male Brown Norway rats and a natural form of 2DG in addition to again examining effects in Fischer-344 rats and the original synthetic 2DG. High levels of both 2DG sources reduced weight gain secondary to reduced food intake in both strains. Histopathological analysis of the hearts revealed increasing vacuolarization of cardiac myocytes with dose, and tissue staining revealed the vacuoles were free of both glycogen and lipid. We did, however, observe higher expression of both cathepsin D and LC3 in the hearts of 2DG-treated rats which indicates an increase in autophagic flux. Although a remarkable CR-like phenotype can be reproduced with 2DG treatment, the ultimate toxicity of 2DG seriously challenges 2DG as a potential CR mimetic in mammals and also raises concerns about other therapeutic applications of the compound.

Allometric Scaling and Cell Ratios in Multi-Organ in vitro Models of Human Metabolism

International Nuclear Information System (INIS)

Ucciferri, Nadia; Sbrana, Tommaso; Ahluwalia, Arti

2014-01-01

Intelligent in vitro models able to recapitulate the physiological interactions between tissues in the body have enormous potential as they enable detailed studies on specific two-way or higher order tissue communication. These models are the first step toward building an integrated picture of systemic metabolism and signaling in physiological or pathological conditions. However, the rational design of in vitro models of cell–cell or cell–tissue interaction is difficult as quite often cell culture experiments are driven by the device used, rather than by design considerations. Indeed, very little research has been carried out on in vitro models of metabolism connecting different cell or tissue types in a physiologically and metabolically relevant manner. Here, we analyze the physiological relationship between cells, cell metabolism, and exchange in the human body using allometric rules, downscaling them to an organ-on-a-plate device. In particular, in order to establish appropriate cell ratios in the system in a rational manner, two different allometric scaling models (cell number scaling model and metabolic and surface scaling model) are proposed and applied to a two compartment model of hepatic-vascular metabolic cross-talk. The theoretical scaling studies illustrate that the design and hence relevance of multi-organ models is principally determined by experimental constraints. Two experimentally feasible model configurations are then implemented in a multi-compartment organ-on-a-plate device. An analysis of the metabolic response of the two configurations demonstrates that their glucose and lipid balance is quite different, with only one of the two models recapitulating physiological-like homeostasis. In conclusion, not only do cross-talk and physical stimuli play an important role in in vitro models, but the numeric relationship between cells is also crucial to recreate in vitro interactions, which can be extrapolated to the in vivo reality.

YAP/TAZ enhance mammalian embryonic neural stem cell characteristics in a Tead-dependent manner

Energy Technology Data Exchange (ETDEWEB)

Han, Dasol; Byun, Sung-Hyun; Park, Soojeong; Kim, Juwan; Kim, Inhee; Ha, Soobong; Kwon, Mookwang; Yoon, Keejung, E-mail: keejung@skku.edu

2015-02-27

Mammalian brain development is regulated by multiple signaling pathways controlling cell proliferation, migration and differentiation. Here we show that YAP/TAZ enhance embryonic neural stem cell characteristics in a cell autonomous fashion using diverse experimental approaches. Introduction of retroviral vectors expressing YAP or TAZ into the mouse embryonic brain induced cell localization in the ventricular zone (VZ), which is the embryonic neural stem cell niche. This change in cell distribution in the cortical layer is due to the increased stemness of infected cells; YAP-expressing cells were colabeled with Sox2, a neural stem cell marker, and YAP/TAZ increased the frequency and size of neurospheres, indicating enhanced self-renewal- and proliferative ability of neural stem cells. These effects appear to be TEA domain family transcription factor (Tead)–dependent; a Tead binding-defective YAP mutant lost the ability to promote neural stem cell characteristics. Consistently, in utero gene transfer of a constitutively active form of Tead2 (Tead2-VP16) recapitulated all the features of YAP/TAZ overexpression, and dominant negative Tead2-EnR resulted in marked cell exit from the VZ toward outer cortical layers. Taken together, these results indicate that the Tead-dependent YAP/TAZ signaling pathway plays important roles in neural stem cell maintenance by enhancing stemness of neural stem cells during mammalian brain development. - Highlights: • Roles of YAP and Tead in vivo during mammalian brain development are clarified. • Expression of YAP promotes embryonic neural stem cell characteristics in vivo in a cell autonomous fashion. • Enhancement of neural stem cell characteristics by YAP depends on Tead. • Transcriptionally active form of Tead alone can recapitulate the effects of YAP. • Transcriptionally repressive form of Tead severely reduces stem cell characteristics.

Ghrelin-AMPK Signaling Mediates the Neuroprotective Effects of Calorie Restriction in Parkinson's Disease

Science.gov (United States)

Bayliss, Jacqueline A.; Lemus, Moyra B.; Stark, Romana; Santos, Vanessa V.; Thompson, Aiysha; Rees, Daniel J.; Galic, Sandra; Elsworth, John D.; Kemp, Bruce E.; Davies, Jeffrey S.

2016-01-01

Calorie restriction (CR) is neuroprotective in Parkinson's disease (PD) although the mechanisms are unknown. In this study we hypothesized that elevated ghrelin, a gut hormone with neuroprotective properties, during CR prevents neurodegeneration in an 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) model of PD. CR attenuated the MPTP-induced loss of substantia nigra (SN) dopamine neurons and striatal dopamine turnover in ghrelin WT but not KO mice, demonstrating that ghrelin mediates CR's neuroprotective effect. CR elevated phosphorylated AMPK and ACC levels in the striatum of WT but not KO mice suggesting that AMPK is a target for ghrelin-induced neuroprotection. Indeed, exogenous ghrelin significantly increased pAMPK in the SN. Genetic deletion of AMPKβ1 and 2 subunits only in dopamine neurons prevented ghrelin-induced AMPK phosphorylation and neuroprotection. Hence, ghrelin signaling through AMPK in SN dopamine neurons mediates CR's neuroprotective effects. We consider targeting AMPK in dopamine neurons may recapitulate neuroprotective effects of CR without requiring dietary intervention. SIGNIFICANCE STATEMENT The neuroprotective mechanisms of calorie restriction (CR) in Parkinson's disease are unknown. Indeed, the difficulty to adhere to CR necessitates an alternative method to recapitulate the neuroprotective benefits of CR while bypassing dietary constraints. Here we show that CR increases plasma ghrelin, which targets substantia nigra dopamine to maintain neuronal survival. Selective deletion on AMPK beta1 and beta2 subunits only in DAT cre-expressing neurons shows that the ghrelin-induced neuroprotection requires activation of AMPK in substantia nigra dopamine neurons. We have discovered ghrelin as a key metabolic signal, and AMPK in dopamine neurons as its target, which links calorie restriction with neuroprotection in Parkinson's disease. Thus, targeting AMPK in dopamine neurons may provide novel neuroprotective benefits in Parkinson's disease. PMID

Pharmacological Induction of Heme Oxygenase-1 Impairs Nuclear Accumulation of Herpes Simplex Virus Capsids upon Infection

Directory of Open Access Journals (Sweden)

Francisco J. Ibáñez

2017-10-01

Full Text Available Heme oxygenase-1 (HO-1 is an inducible enzyme that is expressed in response to physical and chemical stresses, such as ultraviolet radiation, hyperthermia, hypoxia, reactive oxygen species (ROS, as well as cytokines, among others. Its activity can be positively modulated by cobalt protoporphyrin (CoPP and negatively by tin protoporphirin (SnPP. Once induced, HO-1 degrades iron-containing heme into ferrous iron (Fe2+, carbon monoxide (CO and biliverdin. Importantly, numerous products of HO-1 are cytoprotective with anti-apoptotic, anti-oxidant, anti-inflammatory, and anti-cancer effects. The products of HO-1 also display antiviral properties against several viruses, such as the human immunodeficiency virus (HIV, influenza, hepatitis B, hepatitis C, and Ebola virus. Here, we sought to assess the effect of modulating HO-1 activity over herpes simplex virus type 2 (HSV-2 infection in epithelial cells and neurons. There are no vaccines against HSV-2 and treatment options are scarce in the immunosuppressed, in which drug-resistant variants emerge. By using HSV strains that encode structural and non-structural forms of the green fluorescent protein (GFP, we found that pharmacological induction of HO-1 activity with CoPP significantly decreases virus plaque formation and the expression of virus-encoded genes in epithelial cells as determined by flow cytometry and western blot assays. CoPP treatment did not affect virus binding to the cell surface or entry into the cytoplasm, but rather downstream events in the virus infection cycle. Furthermore, we observed that treating cells with a CO-releasing molecule (CORM-2 recapitulated some of the anti-HSV effects elicited by CoPP. Taken together, these findings indicate that HO-1 activity interferes with the replication cycle of HSV and that its antiviral effects can be recapitulated by CO.

Allometric Scaling and Cell Ratios in Multi-Organ in vitro Models of Human Metabolism

Energy Technology Data Exchange (ETDEWEB)

Ucciferri, Nadia [CNR Institute of Clinical Physiology, Pisa (Italy); Interdepartmental Research Center “E. Piaggio”, University of Pisa, Pisa (Italy); Sbrana, Tommaso [Interdepartmental Research Center “E. Piaggio”, University of Pisa, Pisa (Italy); Ahluwalia, Arti, E-mail: arti.ahluwalia@unipi.it [CNR Institute of Clinical Physiology, Pisa (Italy); Interdepartmental Research Center “E. Piaggio”, University of Pisa, Pisa (Italy)

2014-12-17

Intelligent in vitro models able to recapitulate the physiological interactions between tissues in the body have enormous potential as they enable detailed studies on specific two-way or higher order tissue communication. These models are the first step toward building an integrated picture of systemic metabolism and signaling in physiological or pathological conditions. However, the rational design of in vitro models of cell–cell or cell–tissue interaction is difficult as quite often cell culture experiments are driven by the device used, rather than by design considerations. Indeed, very little research has been carried out on in vitro models of metabolism connecting different cell or tissue types in a physiologically and metabolically relevant manner. Here, we analyze the physiological relationship between cells, cell metabolism, and exchange in the human body using allometric rules, downscaling them to an organ-on-a-plate device. In particular, in order to establish appropriate cell ratios in the system in a rational manner, two different allometric scaling models (cell number scaling model and metabolic and surface scaling model) are proposed and applied to a two compartment model of hepatic-vascular metabolic cross-talk. The theoretical scaling studies illustrate that the design and hence relevance of multi-organ models is principally determined by experimental constraints. Two experimentally feasible model configurations are then implemented in a multi-compartment organ-on-a-plate device. An analysis of the metabolic response of the two configurations demonstrates that their glucose and lipid balance is quite different, with only one of the two models recapitulating physiological-like homeostasis. In conclusion, not only do cross-talk and physical stimuli play an important role in in vitro models, but the numeric relationship between cells is also crucial to recreate in vitro interactions, which can be extrapolated to the in vivo reality.

Allometric Scaling and Cell Ratios in Multi-Organ in vitro Models of Human Metabolism.

Science.gov (United States)

Ucciferri, Nadia; Sbrana, Tommaso; Ahluwalia, Arti

2014-01-01

Intelligent in vitro models able to recapitulate the physiological interactions between tissues in the body have enormous potential as they enable detailed studies on specific two-way or higher order tissue communication. These models are the first step toward building an integrated picture of systemic metabolism and signaling in physiological or pathological conditions. However, the rational design of in vitro models of cell-cell or cell-tissue interaction is difficult as quite often cell culture experiments are driven by the device used, rather than by design considerations. Indeed, very little research has been carried out on in vitro models of metabolism connecting different cell or tissue types in a physiologically and metabolically relevant manner. Here, we analyze the physiological relationship between cells, cell metabolism, and exchange in the human body using allometric rules, downscaling them to an organ-on-a-plate device. In particular, in order to establish appropriate cell ratios in the system in a rational manner, two different allometric scaling models (cell number scaling model and metabolic and surface scaling model) are proposed and applied to a two compartment model of hepatic-vascular metabolic cross-talk. The theoretical scaling studies illustrate that the design and hence relevance of multi-organ models is principally determined by experimental constraints. Two experimentally feasible model configurations are then implemented in a multi-compartment organ-on-a-plate device. An analysis of the metabolic response of the two configurations demonstrates that their glucose and lipid balance is quite different, with only one of the two models recapitulating physiological-like homeostasis. In conclusion, not only do cross-talk and physical stimuli play an important role in in vitro models, but the numeric relationship between cells is also crucial to recreate in vitro interactions, which can be extrapolated to the in vivo reality.

A mouse model of DEPDC5-related epilepsy: Neuronal loss of Depdc5 causes dysplastic and ectopic neurons, increased mTOR signaling, and seizure susceptibility.

Science.gov (United States)

Yuskaitis, Christopher J; Jones, Brandon M; Wolfson, Rachel L; Super, Chloe E; Dhamne, Sameer C; Rotenberg, Alexander; Sabatini, David M; Sahin, Mustafa; Poduri, Annapurna

2018-03-01

DEPDC5 is a newly identified epilepsy-related gene implicated in focal epilepsy, brain malformations, and Sudden Unexplained Death in Epilepsy (SUDEP). In vitro, DEPDC5 negatively regulates amino acid sensing by the mTOR complex 1 (mTORC1) pathway, but the role of DEPDC5 in neurodevelopment and epilepsy has not been described. No animal model of DEPDC5-related epilepsy has recapitulated the neurological phenotypes seen in patients, and germline knockout rodent models are embryonic lethal. Here, we establish a neuron-specific Depdc5 conditional knockout mouse by cre-recombination under the Synapsin1 promotor. Depdc5 flox/flox -Syn1 Cre (Depdc5cc+) mice survive to adulthood with a progressive neurologic phenotype that includes motor abnormalities (i.e., hind limb clasping) and reduced survival compared to littermate control mice. Depdc5cc+ mice have larger brains with increased cortical neuron size and dysplastic neurons throughout the cortex, comparable to the abnormal neurons seen in human focal cortical dysplasia specimens. Depdc5 results in constitutive mTORC1 hyperactivation exclusively in neurons as measured by the increased phosphorylation of the downstream ribosomal protein S6. Despite a lack of increased mTORC1 signaling within astrocytes, Depdc5cc+ brains show reactive astrogliosis. We observed two Depdc5cc+ mice to have spontaneous seizures, including a terminal seizure. We demonstrate that as a group Depdc5cc+ mice have lowered seizure thresholds, as evidenced by decreased latency to seizures after chemoconvulsant injection and increased mortality from pentylenetetrazole-induced seizures. In summary, our neuron-specific Depdc5 knockout mouse model recapitulates clinical, pathological, and biochemical features of human DEPDC5-related epilepsy and brain malformations. We thereby present an important model in which to study targeted therapeutic strategies for DEPDC5-related conditions. Copyright © 2017 Elsevier Inc. All rights reserved.

YAP/TAZ enhance mammalian embryonic neural stem cell characteristics in a Tead-dependent manner

International Nuclear Information System (INIS)

Han, Dasol; Byun, Sung-Hyun; Park, Soojeong; Kim, Juwan; Kim, Inhee; Ha, Soobong; Kwon, Mookwang; Yoon, Keejung

2015-01-01

Mammalian brain development is regulated by multiple signaling pathways controlling cell proliferation, migration and differentiation. Here we show that YAP/TAZ enhance embryonic neural stem cell characteristics in a cell autonomous fashion using diverse experimental approaches. Introduction of retroviral vectors expressing YAP or TAZ into the mouse embryonic brain induced cell localization in the ventricular zone (VZ), which is the embryonic neural stem cell niche. This change in cell distribution in the cortical layer is due to the increased stemness of infected cells; YAP-expressing cells were colabeled with Sox2, a neural stem cell marker, and YAP/TAZ increased the frequency and size of neurospheres, indicating enhanced self-renewal- and proliferative ability of neural stem cells. These effects appear to be TEA domain family transcription factor (Tead)–dependent; a Tead binding-defective YAP mutant lost the ability to promote neural stem cell characteristics. Consistently, in utero gene transfer of a constitutively active form of Tead2 (Tead2-VP16) recapitulated all the features of YAP/TAZ overexpression, and dominant negative Tead2-EnR resulted in marked cell exit from the VZ toward outer cortical layers. Taken together, these results indicate that the Tead-dependent YAP/TAZ signaling pathway plays important roles in neural stem cell maintenance by enhancing stemness of neural stem cells during mammalian brain development. - Highlights: • Roles of YAP and Tead in vivo during mammalian brain development are clarified. • Expression of YAP promotes embryonic neural stem cell characteristics in vivo in a cell autonomous fashion. • Enhancement of neural stem cell characteristics by YAP depends on Tead. • Transcriptionally active form of Tead alone can recapitulate the effects of YAP. • Transcriptionally repressive form of Tead severely reduces stem cell characteristics

Three-dimensional culture of sebaceous gland cells revealing the role of prostaglandin E{sub 2}-induced activation of canonical Wnt signaling

Energy Technology Data Exchange (ETDEWEB)

Yoshida, Go J., E-mail: medical21go@yahoo.co.jp; Saya, Hideyuki

2013-09-06

Highlights: •Three-dimensional culture generates “semi-vivo” sebaceous glands. •Xenograft model failed to mimic the biology of sebaceous glands in vivo. •Proinflammatory cytokine PGE{sub 2} enhances Wnt signal activity in the organoids. •PGE{sub 2} influences on the mitochondrial and lipid metabolism in the organoids. •Considering 3R agenda, “semi-vivo” sebaceous glands are useful for research. -- Abstract: Background: Prostaglandin E{sub 2} (PGE{sub 2}) is a proinflammatory mediator and activates the canonical Wnt–β-catenin signaling pathway in hematopoietic stem cells. The SZ95 cell line was established from human sebaceous gland cells and is studied as a model system for these cells. Given that 2D culture of SZ95 cells does not recapitulate the organization of sebaceous glands in situ, we developed a 3D culture system for these cells and examined the effects of PGE{sub 2} on cell morphology and function. Results: SZ95 cells maintained in 3D culture formed organoids that mimicked the organization of sebaceous glands in situ, including the establishment of a basement membrane. Organoids exposed to PGE{sub 2} were larger and adopted a more complex organization compared with control organoids. PGE{sub 2} activated the canonical Wnt signaling pathway as well as increased cell viability and proliferation, mitochondrial metabolism, and lipid synthesis in the organoids. Conclusions: Culture of SZ95 cells in 3D culture system recapitulates the structure and susceptibility to PGE{sub 2} of sebaceous glands in situ and should prove useful for studies of the response of these glands to inflammation and other environmental stressors. Our results also implicate PGE{sub 2}-induced activation of canonical Wnt signaling pathway in regulation of the morphology,proliferation, and function of “semi-vivo” sebaceous glands.

Spontaneous food allergy in Was-/- mice occurs independent of FcεRI-mediated mast cell activation.

Science.gov (United States)

Lexmond, W S; Goettel, J A; Sallis, B F; McCann, K; Rings, E H H M; Jensen-Jarolim, E; Nurko, S; Snapper, S B; Fiebiger, E

2017-12-01

Food allergies are a growing health problem, and the development of therapies that prevent disease onset is limited by the lack of adjuvant-free experimental animal models. We compared allergic sensitization in patients with food allergy or Wiskott-Aldrich syndrome (WAS) and defined whether spontaneous disease in Was -/- mice recapitulates the pathology of a conventional disease model and/or human food allergy. Comparative ImmunoCAP ISAC microarray was performed in patients with food allergy or WAS. Spontaneous food allergy in Was -/- mice was compared to an adjuvant-based model in wild-type mice (WT-OVA/alum). Intestinal and systemic anaphylaxis was assessed, and the role of the high-affinity IgE Fc receptor (FcεRI) in allergic sensitization was evaluated using Was -/- Fcer1a -/- mice. Polysensitization to food was detected in both WAS and food-allergic patients which was recapitulated in the Was -/- model. Oral administration of ovalbumin (OVA) in Was -/- mice induced low titers of OVA-specific IgE compared to the WT-OVA/alum model. Irrespectively, 79% of Was -/- mice developed allergic diarrhea following oral OVA challenge. Systemic anaphylaxis occurred in Was -/- mice (95%) with a mortality rate >50%. Spontaneous sensitization and intestinal allergy occurred independent of FcεRI expression on mast cells (MCs) and basophils. Was -/- mice provide a model of food allergy with the advantage of mimicking polysensitization and low food-antigen IgE titers as observed in humans with clinical food allergy. This model will facilitate studies on aberrant immune responses during spontaneous disease development. Our results imply that therapeutic targeting of the IgE/FcεRI activation cascade will not affect sensitization to food. © 2017 EAACI and John Wiley and Sons A/S. Published by John Wiley and Sons Ltd.

The self-assembling process and applications in tissue engineering

Science.gov (United States)

Lee, Jennifer K.; Link, Jarrett M.; Hu, Jerry C. Y.; Athanasiou, Kyriacos A.

2018-01-01

Tissue engineering strives to create neotissues capable of restoring function. Scaffold-free technologies have emerged that can recapitulate native tissue function without the use of an exogenous scaffold. This chapter will survey, in particular, the self-assembling and self-organization processes as scaffold-free techniques. Characteristics and benefits of each process are described, and key examples of tissues created using these scaffold-free processes are examined to provide guidance for future tissue engineering developments. This chapter aims to explore the potential of self-assembly and self-organization scaffold-free approaches, detailing the recent progress in the in vitro tissue engineering of biomimetic tissues with these methods, toward generating functional tissue replacements. PMID:28348174

Induction of pluripotency by defined factors

International Nuclear Information System (INIS)

Okita, Keisuke; Yamanaka, Shinya

2010-01-01

Somatic cells can be reprogrammed into pluripotent stem cells by introducing a combination of several transcription factors. The induced pluripotent stem (iPS) cells from a patient's somatic cells could be useful source of cells for drug discovery and cell transplantation therapies. However, most human iPS cells are made by viral vectors, such as retrovirus and lentivirus, which integrate the reprogramming factors into host genomes and may increase the risk of tumor formation. Studies of the mechanisms underlying the reprogramming and establishment of non-integration methods contribute evidence to resolve the safety concerns associated with iPS cells. On the other hand, patient-specific iPS cells have already been established and used for recapitulating disease pathology.

Zebrafish as a Model for the Study of Human Myeloid Malignancies

Directory of Open Access Journals (Sweden)

Jeng-Wei Lu

2015-01-01

Full Text Available Myeloid malignancies are heterogeneous disorders characterized by uncontrolled proliferation or/and blockage of differentiation of myeloid progenitor cells. Although a substantial number of gene alterations have been identified, the mechanism by which these abnormalities interact has yet to be elucidated. Over the past decades, zebrafish have become an important model organism, especially in biomedical research. Several zebrafish models have been developed to recapitulate the characteristics of specific myeloid malignancies that provide novel insight into the pathogenesis of these diseases and allow the evaluation of novel small molecule drugs. This report will focus on illustrative examples of applications of zebrafish models, including transgenesis, zebrafish xenograft models, and cell transplantation approaches, to the study of human myeloid malignancies.

Human pluripotent stem cells: an emerging model in developmental biology.

Science.gov (United States)

Zhu, Zengrong; Huangfu, Danwei

2013-02-01

Developmental biology has long benefited from studies of classic model organisms. Recently, human pluripotent stem cells (hPSCs), including human embryonic stem cells and human induced pluripotent stem cells, have emerged as a new model system that offers unique advantages for developmental studies. Here, we discuss how studies of hPSCs can complement classic approaches using model organisms, and how hPSCs can be used to recapitulate aspects of human embryonic development 'in a dish'. We also summarize some of the recently developed genetic tools that greatly facilitate the interrogation of gene function during hPSC differentiation. With the development of high-throughput screening technologies, hPSCs have the potential to revolutionize gene discovery in mammalian development.

Review Paper: A Review on Brain Stimulation Using Low Intensity Focused Ultrasound

Directory of Open Access Journals (Sweden)

Ehsan Rezayat

2016-07-01

Full Text Available Brain stimulation techniques are important in both basic and clinical studies. Majority of well-known brain stimulating techniques have low spatial resolution or entail invasive processes. Low intensity focused ultrasound (LIFU seems to be a proper candidate for dealing with such deficiencies. This review recapitulates studies which explored the effects of LIFU on brain structures and its function, in both research and clinical areas. Although the mechanism of LIFU action is still unclear, its different effects from molecular level up to behavioral level can be explored in animal and human brain. It can also be coupled with brain imaging assessments in future research.

Aging of bone marrow mesenchymal stromal/stem cells: Implications on autologous regenerative medicine.

Science.gov (United States)

Charif, N; Li, Y Y; Targa, L; Zhang, L; Ye, J S; Li, Y P; Stoltz, J F; Han, H Z; de Isla, N

2017-01-01

With their proliferation, differentiation into specific cell types, and secretion properties, mesenchymal stromal/stem cells (MSC) are very interesting tools to be used in regenerative medicine. Bone marrow (BM) was the first MSC source characterized. In the frame of autologous MSC therapy, it is important to detect donor's parameters affecting MSC potency. Age of the donors appears as one parameter that could greatly affect MSC properties. Moreover, in vitro cell expansion is needed to obtain the number of cells necessary for clinical developments. It will lead to in vitro cell aging that could modify cell properties. This review recapitulates several studies evaluating the effect of in vitro and in vivo MSC aging on cell properties.

Gastrointestinal Epithelial Organoid Cultures from Postsurgical Tissues.

Science.gov (United States)

Hahn, Soojung; Yoo, Jongman

2017-08-17

An organoid is a cellular structure three-dimensionally (3D) cultured from self-organizing stem cells in vitro, which has a cell population, architectures, and organ specific functions like the originating organs. Recent advances in the 3D culture of isolated intestinal crypts or gastric glands have enabled the generation of human gastrointestinal epithelial organoids. Gastrointestinal organoids recapitulate the human in vivo physiology because of all the intestinal epithelial cell types that differentiated and proliferated from tissue resident stem cells. Thus far, gastrointestinal organoids have been extensively used for generating gastrointestinal disease models. This protocol describes the method of isolating a gland or crypt using stomach or colon tissue after surgery and establishing them into gastroids or colonoids.

Bovine annulus fibrosus cell lines isolated from intervertebral discs

Directory of Open Access Journals (Sweden)

Petra Kraus

2016-12-01

Full Text Available The adult bovine (Bos taurus intervertebral disc is primarily comprised of two major tissue types: The outer annulus fibrosus (AF and the central nucleus pulposus (NP. We isolated several primary cell lineages of passage (P 0 cells from the AF tissue omitting typically used enzymatic tissue digestion protocols. The cells grow past p10 without signs of senescence in DMEM + 10% FCS on 0.1% gelatin coated/uncoated surfaces of standard cell culture plates and survive freeze-thawing. Preliminary analysis of the AF derived cells for expression of the two structural genes Col1a1 and Col2a1 was performed by PISH recapitulating the expression observed in vivo.

Nuclear spectroscopy and quantum chaos

International Nuclear Information System (INIS)

Sakata, Fumihiko; Marumori, Toshio; Hashimoto, Yukio; Yamamoto, Yoshifumi; Tsukuma, Hidehiko; Iwasawa, Kazuo.

1990-05-01

In this paper, a recent development of INS-TSUKUBA joint research project on large-amplitude collective motion is summerized. The classical theory of nuclear collective dynamics formulated within the time-dependent Hartree-Fock theory is recapitulated and decisive role of the level crossing in the single-particle dynamics on the order-to-chaos transition of collective motion is discussed in detail. Extending the basic idea of the classical theory, we discuss a quantum theory of nuclear collective dynamics which allows us to properly define a concept of quantum chaos for each eigenfunction. By using numerical calculation, we illustrate what the quantum chaos for each eigenfunction means and its relation to usual definition based on the random matrix theory. (author)

Small Molecules from Spiders Used as Chemical Probes

DEFF Research Database (Denmark)

Olsen, Christian Adam; Kristensen, Anders S.; Strømgaard, Kristian

2011-01-01

Spiders are important species in ecological systems and as major predators of insects they are endowed with a plethora of low‐molecular‐weight natural products having intriguing biological activities. The isolation and biological characterization of these entities are well established, however......, only very recently have these compounds been used as templates for the design, synthesis, and biological evaluation of synthetic analogues. In contrast, the investigation of compounds responsible for chemical communication between spiders is far less developed, but recently new light has been shed onto...... the area of pheromones and allomones from spiders. Herein, we recapitulate these recent results, put them into perspective with previous findings, and provide an outlook for future studies of these chemotypes....

Wetting and layering transitions in a nano-dendrimer PAMAM structure: Monte Carlo study

Science.gov (United States)

Aouini, S.; Ziti, S.; Labrim, H.; Bahmad, L.

2016-10-01

This study is based on a nano-model of the dendrimer polyamidoamine (PAMAM). The idea is to examine the magnetic properties of such models in the context of wetting and the layering transitions. The studied system consists of spins σ ={1/2} Ising ferromagnetic in real nanostructure found in different scientific domains. To study this system, we perform Monte Carlo simulations leading to interesting results recapitulated in two classes. The former is the ground state phase diagrams study. The latter is the magnetic properties at non null temperatures. Also, we analyzed the effect of the terms present in the Hamiltonian governing our system such as the external magnetic field and the exchange couplings interactions.

Natural product-derived pharmacological modulators of Nrf2/ARE pathway for chronic diseases.

Science.gov (United States)

Kumar, Hemant; Kim, In-Su; More, Sandeep Vasant; Kim, Byung-Wook; Choi, Dong-Kug

2014-01-01

Covering: 2000 to 2013. Oxidative stress is the central component of chronic diseases. The nuclear factor erythroid 2-related factor 2/antioxidant response element (Nrf2/ARE) pathway is vital in the up-regulation of cytoprotective genes and enzymes in response to oxidative stress and treatment with certain dietary phytochemicals. Herein, we classify bioactive compounds derived from natural products that are Nrf2/ARE pathway activators and recapitulate the molecular mechanisms for inducing Nrf2 to provide favorable effects in experimental models of chronic diseases. Moreover, pharmacological inhibition of Nrf2 signalling has emerged as promising strategy against multi-drug resistance thereby improving the treatment efficacy. We have also enlisted natural product-derived inhibitors of Nrf2/ARE pathway.

Strong coupling phase in QED

International Nuclear Information System (INIS)

Aoki, Ken-ichi

1988-01-01

Existence of a strong coupling phase in QED has been suggested in solutions of the Schwinger-Dyson equation and in Monte Carlo simulation of lattice QED. In this article we recapitulate the previous arguments, and formulate the problem in the modern framework of the renormalization theory, Wilsonian renormalization. This scheme of renormalization gives the best understanding of the basic structure of a field theory especially when it has a multi-phase structure. We resolve some misleading arguments in the previous literature. Then we set up a strategy to attack the strong phase, if any. We describe a trial; a coupled Schwinger-Dyson equation. Possible picture of the strong coupling phase QED is presented. (author)

First principles design of a core bioenergetic transmembrane electron-transfer protein

Energy Technology Data Exchange (ETDEWEB)

Goparaju, Geetha; Fry, Bryan A.; Chobot, Sarah E.; Wiedman, Gregory; Moser, Christopher C.; Leslie Dutton, P.; Discher, Bohdana M.

2016-05-01

Here we describe the design, Escherichia coli expression and characterization of a simplified, adaptable and functionally transparent single chain 4-α-helix transmembrane protein frame that binds multiple heme and light activatable porphyrins. Such man-made cofactor-binding oxidoreductases, designed from first principles with minimal reference to natural protein sequences, are known as maquettes. This design is an adaptable frame aiming to uncover core engineering principles governing bioenergetic transmembrane electron-transfer function and recapitulate protein archetypes proposed to represent the origins of photosynthesis. This article is part of a Special Issue entitled Biodesign for Bioenergetics — the design and engineering of electronic transfer cofactors, proteins and protein networks, edited by Ronald L. Koder and J.L. Ross Anderson.

A biomimetic physiological model for human adipose tissue by adipocytes and endothelial cell cocultures with spatially controlled distribution

International Nuclear Information System (INIS)

Yao, Rui; Zhang, Renji; Lin, Feng; Du, Yanan; Luan, Jie

2013-01-01

An in vitro model that recapitulates the characteristics of native human adipose tissue would largely benefit pathology studies and therapy development. In this paper, we fabricated a physiological model composed of both human adipocytes and endothelial cells with spatially controlled distribution that biomimics the structure and composition of human adipose tissue. Detailed studies into the cell–cell interactions between the adipocytes and endothelial cells revealed a mutual-enhanced effect which resembles the in vivo routine. Furthermore, comparisons between planar coculture and model coculture demonstrated improved adipocyte function as well as endothelial cell proliferation under the same conditions. This research provided a reliable model for human adipose tissue development studies and potential obesity-related therapy development. (paper)

Comparative Pathology of Hepatitis A Virus and Hepatitis E Virus Infection.

Science.gov (United States)

Cullen, John M; Lemon, Stanley M

2018-04-30

Hepatitis A virus (HAV) and hepatitis E virus (HEV) cause acute, self-limiting hepatic infections that are usually spread by the fecal-oral route in humans. Naturally occurring and experimental infections are possible in a variety of nonhuman primates and, in the case of HEV, a number of other species. Many advances in understanding the pathogenesis of these viruses have come from studies in experimental animals. In general, animals infected with these viruses recapitulate the histologic lesions seen in infected humans, but typically with less severe clinical and histopathological manifestations. This review describes the histopathologic changes associated with HAV and HEV infection in humans and experimental animals. Copyright © 2018 Cold Spring Harbor Laboratory Press; all rights reserved.

Hypoxia-induced retinopathy model in adult zebrafish

DEFF Research Database (Denmark)

Cao, Ziquan; Jensen, Lasse D.; Rouhi, Pegah

2010-01-01

Hypoxia-induced vascular responses, including angiogenesis, vascular remodeling and vascular leakage, significantly contribute to the onset, development and progression of retinopathy. However, until recently there were no appropriate animal disease models recapitulating adult retinopathy available....... In this article, we describe protocols that create hypoxia-induced retinopathy in adult zebrafish. Adult fli1: EGFP zebrafish are placed in hypoxic water for 3-10 d and retinal neovascularization is analyzed using confocal microscopy. It usually takes 11 d to obtain conclusive results using the hypoxia......-induced retinopathy model in adult zebrafish. This model provides a unique opportunity to study kinetically the development of retinopathy in adult animals using noninvasive protocols and to assess therapeutic efficacy of orally active antiangiogenic drugs....

Assistent report to Dr. Felix Oboussier

International Nuclear Information System (INIS)

Jelinek-Fink, P.

1980-01-01

The author describes the situation related to the supply of the Community with nuclear fuels and to services going with the fuel cycle as well as international problems and the necessary objectives of the European Community for ensuring the nuclear fuel cycle in Europe. He recapitulates that during the past few years nuclear power policy has become diversiform and more complicated. The raw materials exporting countries have made demands which could not be accepted in this form by the import-dependent European countries. Tensions arising between friendly nations have to be solved. The European Community has to take the lead and take confidence-generating measures such as giving political guarantees and establishing a working inspection system. (HSCH) [de

On the unstable mode merging of gravity-inertial waves with Rossby waves

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J. F. McKenzie

2011-08-01

Full Text Available We recapitulate the results of the combined theory of gravity-inertial-Rossby waves in a rotating, stratified atmosphere. The system is shown to exhibit a "local" (JWKB instability whenever the phase speed of the low-frequency-long wavelength westward propagating Rossby wave exceeds the phase speed ("Kelvin" speed of the high frequency-short wavelength gravity-inertial wave. This condition ensures that mode merging, leading to instability, takes place in some intermediate band of frequencies and wave numbers. The contention that such an instability is "spurious" is not convincing. The energy source of the instability resides in the background enthalpy which can be released by the action of the gravitational buoyancy force, through the combined wave modes.

Extreme Ultraviolet to Visible Dispersed Single Photon Detection for Highly Sensitive Sensing of Fundamental Processes in Diverse Samples

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Andreas Hans

2018-05-01

Full Text Available The detection of a single photon is the most sensitive method for sensing of photon emission. A common technique for single photon detection uses microchannel plate arrays combined with photocathodes and position sensitive anodes. Here, we report on the combination of such detectors with grating diffraction spectrometers, constituting a low-noise wavelength resolving photon spectroscopy apparatus with versatile applicability. We recapitulate the operation principle of such detectors and present the details of the experimental set-up, which we use to investigate fundamental mechanisms in atomic and molecular systems after excitation with tuneable synchrotron radiation. Extensions for time and polarization resolved measurements are described and examples of recent applications in current research are given.

On bulk viscosity and moduli decay

International Nuclear Information System (INIS)

Laine, Mikko

2010-01-01

This pedagogically intended lecture, one of four under the header 'Basics of thermal QCD', reviews an interesting relationship, originally pointed out by Boedeker, that exists between the bulk viscosity of Yang-Mills theory (of possible relevance to the hydrodynamics of heavy ion collision experiments) and the decay rate of scalar fields coupled very weakly to a heat bath (appearing in some particle physics inspired cosmological scenarios). This topic serves, furthermore, as a platform on which a number of generic thermal field theory concepts are illustrated. The other three lectures (on the QCD equation of state and the rates of elastic as well as inelastic processes experienced by heavy quarks) are recapitulated in brief encyclopedic form. (author)

Band model for d- and f-metals

International Nuclear Information System (INIS)

Koelling, D.D.

1982-01-01

The application of band theory to metallic systems with d- and f-orbitals in the valence and conduction bands is discussed. Because such an application pushes theory and technique to their limits, several important features are briefly recapitulated. Within the transition metal systems, the elemental systems are used to discuss the fundamental formalism being applied and the newer directions into more complex systems are mentioned. Here we focus more on anisotropic properties and Fermi surface properties. Within the f-orbital systems, the focus is more on Ce and its compounds because of current interest with a relatively brief discussion of the actinides. the point of view advanced, however, has its origins in actinide research

Sublingual flagellin protects against acute pneumococcal pneumonia in a TLR5-dependent and NLRC4-independent fashion.

Science.gov (United States)

Muñoz-Wolf, Natalia; Rial, Analía; Fougeron, Delphine; Tabareau, Julien; Sirard, Jean-Claude; Chabalgoity, José A

2016-09-01

To evaluate efficacy of sublingual flagellin to treat acute pneumonia. Mice were treated sublingually with flagellin and challenged intranasally with a lethal dose of pneumococcus. Flagellins lacking TLR5 or NLRC4 activation domains were used to assess their contribution to protection. Sublingual flagellin protected mice in a TLR5-dependent, NLRC4-independent fashion. Neutrophils were required for protection. Flagellin-stimulated lung epithelial cells recapitulated the lung's transcriptional profile suggesting they could be targeted by flagellin in vivo. Ligation of TLR5, a pathogen recognition receptor not naturally engaged by pneumococcus, protects mice from invasive pneumonia when administered via sublingual route. This can be a highly cost-effective alternative therapy against pneumonia.

Structural characterization of suppressor lipids by high-resolution mass spectrometry

DEFF Research Database (Denmark)

Rovillos, Mary Joy; Pauling, Josch Konstantin; Hannibal-Bach, Hans Kristian

2016-01-01

RATIONALE: Suppressor lipids were originally identified in 1993 and reported to encompass six lipid classes that enable Saccharomyces cerevisiae to live without sphingolipids. Structural characterization, using non-mass spectrometric approaches, revealed that these suppressor lipids are very long...... chain fatty acid (VLCFA)-containing glycerophospholipids with polar head groups that are typically incorporated into sphingolipids. Here we report, for the first time, the structural characterization of the yeast suppressor lipids using high-resolution mass spectrometry. METHODS: Suppressor lipids were...... isolated by preparative chromatography and subjected to structural characterization using hybrid quadrupole time-of-flight and ion trap-orbitrap mass spectrometry. RESULTS: Our investigation recapitulates the overall structural features of the suppressor lipids and provides an in-depth characterization...

Intact glycopeptide characterization using mass spectrometry.

Science.gov (United States)

Cao, Li; Qu, Yi; Zhang, Zhaorui; Wang, Zhe; Prytkova, Iya; Wu, Si

2016-05-01

Glycosylation is one of the most prominent and extensively studied protein post-translational modifications. However, traditional proteomic studies at the peptide level (bottom-up) rarely characterize intact glycopeptides (glycosylated peptides without removing glycans), so no glycoprotein heterogeneity information is retained. Intact glycopeptide characterization, on the other hand, provides opportunities to simultaneously elucidate the glycan structure and the glycosylation site needed to reveal the actual biological function of protein glycosylation. Recently, significant improvements have been made in the characterization of intact glycopeptides, ranging from enrichment and separation, mass spectroscopy (MS) detection, to bioinformatics analysis. In this review, we recapitulated currently available intact glycopeptide characterization methods with respect to their advantages and limitations as well as their potential applications.

Accordion-like honeycombs for tissue engineering of cardiac anisotropy

Science.gov (United States)

Engelmayr, George C.; Cheng, Mingyu; Bettinger, Christopher J.; Borenstein, Jeffrey T.; Langer, Robert; Freed, Lisa E.

2008-12-01

Tissue-engineered grafts may be useful in myocardial repair; however, previous scaffolds have been structurally incompatible with recapitulating cardiac anisotropy. Here, we use microfabrication techniques to create an accordion-like honeycomb microstructure in poly(glycerol sebacate), which yields porous, elastomeric three-dimensional (3D) scaffolds with controllable stiffness and anisotropy. Accordion-like honeycomb scaffolds with cultured neonatal rat heart cells demonstrated utility through: (1) closely matched mechanical properties compared to native adult rat right ventricular myocardium, with stiffnesses controlled by polymer curing time; (2) heart cell contractility inducible by electric field stimulation with directionally dependent electrical excitation thresholds (pthe formation of grafts with aligned heart cells and mechanical properties more closely resembling native myocardium.

Creating and managing a paperless health information management department.

Science.gov (United States)

Greene, Zelda B

2002-08-01

Over the last 10 to 15 years, the health care industry has experienced dramatic changes in health care delivery, consumer needs, and demands. The medical record, a recapitulation of the care patients receive, continues to be one of the most vital components of the health care delivery system. It serves as a crucial administrative, clinical, financial, and research tool. Health information managers, striving to meet ever-changing requirements, have turned to electronic record processing to meet these changes. The following article describes one hospital's journey from a cumbersome paper environment to an electronic environment that not only resulted in improved customer service but also provided employees with renewed job satisfaction and increased skill levels.

mRNA-Seq of single prostate cancer circulating tumor cells reveals recapitulation of gene expression and pathways found in prostate cancer.

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Gordon M Cann

Full Text Available Circulating tumor cells (CTC mediate metastatic spread of many solid tumors and enumeration of CTCs is currently used as a prognostic indicator of survival in metastatic prostate cancer patients. Some evidence suggests that it is possible to derive additional information about tumors from expression analysis of CTCs, but the technical difficulty of isolating and analyzing individual CTCs has limited progress in this area. To assess the ability of a new generation of MagSweeper to isolate intact CTCs for downstream analysis, we performed mRNA-Seq on single CTCs isolated from the blood of patients with metastatic prostate cancer and on single prostate cancer cell line LNCaP cells spiked into the blood of healthy donors. We found that the MagSweeper effectively isolated CTCs with a capture efficiency that matched the CellSearch platform. However, unlike CellSearch, the MagSweeper facilitates isolation of individual live CTCs without contaminating leukocytes. Importantly, mRNA-Seq analysis showed that the MagSweeper isolation process did not have a discernible impact on the transcriptional profile of single LNCaPs isolated from spiked human blood, suggesting that any perturbations caused by the MagSweeper process on the transcriptional signature of isolated cells are modest. Although the RNA from patient CTCs showed signs of significant degradation, consistent with reports of short half-lives and apoptosis amongst CTCs, transcriptional signatures of prostate tissue and of cancer were readily detectable with single CTC mRNA-Seq. These results demonstrate that the MagSweeper provides access to intact CTCs and that these CTCs can potentially supply clinically relevant information.

mRNA-Seq of single prostate cancer circulating tumor cells reveals recapitulation of gene expression and pathways found in prostate cancer.

Science.gov (United States)

Cann, Gordon M; Gulzar, Zulfiqar G; Cooper, Samantha; Li, Robin; Luo, Shujun; Tat, Mai; Stuart, Sarah; Schroth, Gary; Srinivas, Sandhya; Ronaghi, Mostafa; Brooks, James D; Talasaz, Amirali H

2012-01-01

Circulating tumor cells (CTC) mediate metastatic spread of many solid tumors and enumeration of CTCs is currently used as a prognostic indicator of survival in metastatic prostate cancer patients. Some evidence suggests that it is possible to derive additional information about tumors from expression analysis of CTCs, but the technical difficulty of isolating and analyzing individual CTCs has limited progress in this area. To assess the ability of a new generation of MagSweeper to isolate intact CTCs for downstream analysis, we performed mRNA-Seq on single CTCs isolated from the blood of patients with metastatic prostate cancer and on single prostate cancer cell line LNCaP cells spiked into the blood of healthy donors. We found that the MagSweeper effectively isolated CTCs with a capture efficiency that matched the CellSearch platform. However, unlike CellSearch, the MagSweeper facilitates isolation of individual live CTCs without contaminating leukocytes. Importantly, mRNA-Seq analysis showed that the MagSweeper isolation process did not have a discernible impact on the transcriptional profile of single LNCaPs isolated from spiked human blood, suggesting that any perturbations caused by the MagSweeper process on the transcriptional signature of isolated cells are modest. Although the RNA from patient CTCs showed signs of significant degradation, consistent with reports of short half-lives and apoptosis amongst CTCs, transcriptional signatures of prostate tissue and of cancer were readily detectable with single CTC mRNA-Seq. These results demonstrate that the MagSweeper provides access to intact CTCs and that these CTCs can potentially supply clinically relevant information.

Dioxin exposure of human CD34+ hemopoietic cells induces gene expression modulation that recapitulates its in vivo clinical and biological effects

International Nuclear Information System (INIS)

Fracchiolla, Nicola Stefano; Todoerti, Katia; Bertazzi, Pier Alberto; Servida, Federica; Corradini, Paolo; Carniti, Cristiana; Colombi, Antonio; Cecilia Pesatori, Angela; Neri, Antonino; Deliliers, Giorgio Lambertenghi

2011-01-01

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) has a large number of biological effects, including skin, cardiovascular, neurologic diseases, diabetes, infertility, cancers and immunotoxicity. We analysed the in vitro TCDD effects on human CD34 + cells and tested the gene expression modulation by means of microarray analyses before and after TCDD exposure. We identified 257 differentially modulated probe sets, identifying 221 well characterized genes. A large part of these resulted associated to cell adhesion and/or angiogenesis and to transcription regulation. Synaptic transmission and visual perception functions, with the particular involvement of the GABAergic pathway were also significantly modulated. Numerous transcripts involved in cell cycle or cell proliferation, immune response, signal transduction, ion channel activity or calcium ion binding, tissue development and differentiation, female or male fertility or in several metabolic pathways were also affected after dioxin exposure. The transcriptional profile induced by TCDD treatment on human CD34 + cells strikingly reproduces the clinical and biological effects observed in individuals exposed to dioxin and in biological experimental systems. Our data support a role of dioxin in the neoplastic transformation of hemopoietic stem cells and in immune modulation processes after in vivo exposure, as indicated by the epidemiologic data in dioxin accidentally exposed populations, providing a molecular basis for it. In addition, TCDD alters genes associated to glucidic and lipidic metabolisms, to GABAergic transmission or involved in male and female fertility, thus providing a possible explanation of the diabetogenic, dyslipidemic, neurologic and fertility effects induced by TCDD in vivo exposure.

A Mouse Model that Recapitulates Cardinal Features of the 15q13.3 Microdeletion Syndrome Including Schizophrenia- and Epilepsy-Related Alterations

DEFF Research Database (Denmark)

Fejgin, Kim; Nielsen, Jacob; Birknow, Michelle R.

2014-01-01

to develop myoclonic and absence-like seizures but decreased propensity for clonic and tonic seizures. Furthermore, they had impaired long-term spatial reference memory and a decreased theta frequency in hippocampus and prefrontal cortex. Electroencephalogram characterization revealed auditory processing......Background: Genome-wide scans have uncovered rare copy number variants conferring high risk of psychiatric disorders. The 15q13.3 microdeletion is associated with a considerably increased risk of idiopathic generalized epilepsy, intellectual disability, and schizophrenia. Methods: A 15q13.......3 microdeletion mouse model (Df[h15q13]/) was generated by hemizygous deletion of the orthologous region and characterized with focus on schizophrenia- and epilepsy-relevant parameters. Results: Df(h15q13)/ mice showed marked changes in neuronal excitability in acute seizure assays, with increased propensity...

Zebrafish brd2a and brd2b are paralogous members of the bromodomain-ET (BET family of transcriptional coregulators that show structural and expression divergence

Directory of Open Access Journals (Sweden)

Bee Katharine J

2008-04-01

Full Text Available Abstract Background Brd2 belongs to the bromodomain-extraterminal domain (BET family of transcriptional co-regulators, and functions as a pivotal histone-directed recruitment scaffold in chromatin modification complexes affecting signal-dependent transcription. Brd2 facilitates expression of genes promoting proliferation and is implicated in apoptosis and in egg maturation and meiotic competence in mammals; it is also a susceptibility gene for juvenile myoclonic epilepsy (JME in humans. The brd2 ortholog in Drosophila is a maternal effect, embryonic lethal gene that regulates several homeotic loci, including Ultrabithorax. Despite its importance, there are few systematic studies of Brd2 developmental expression in any organism. To help elucidate both conserved and novel gene functions, we cloned and characterized expression of brd2 cDNAs in zebrafish, a vertebrate system useful for genetic analysis of development and disease, and for study of the evolution of gene families and functional diversity in chordates. Results We identify cDNAs representing two paralogous brd2 loci in zebrafish, brd2a on chromosome 19 and brd2b on chromosome 16. By sequence similarity, syntenic and phylogenetic analyses, we present evidence for structural divergence of brd2 after gene duplication in fishes. brd2 paralogs show potential for modular domain combinations, and exhibit distinct RNA expression patterns throughout development. RNA in situ hybridizations in oocytes and embryos implicate brd2a and brd2b as maternal effect genes involved in egg polarity and egg to embryo transition, and as zygotic genes important for development of the vertebrate nervous system and for morphogenesis and differentiation of the digestive tract. Patterns of brd2 developmental expression in zebrafish are consistent with its proposed role in Homeobox gene regulation. Conclusion Expression profiles of zebrafish brd2 paralogs support a role in vertebrate developmental patterning and

Induction of pluripotency by defined factors

Energy Technology Data Exchange (ETDEWEB)

Okita, Keisuke, E-mail: okita@cira.kyoto-u.ac.jp [Center for iPS Cell Research and Application (CiRA), Institute for Integrated Cell-Material Sciences, Kyoto University, Kyoto 606-8507 (Japan); Yamanaka, Shinya [Center for iPS Cell Research and Application (CiRA), Institute for Integrated Cell-Material Sciences, Kyoto University, Kyoto 606-8507 (Japan); Department of Stem Cell Biology, Institute for Frontier Medical Sciences, Kyoto University, Kyoto 606-8507 (Japan); Yamanaka iPS Cell Special Project, Japan Science and Technology Agency, Kawaguchi 332-0012 (Japan); Gladstone Institute of Cardiovascular Disease, San Francisco, CA 94158 (United States)

2010-10-01

Somatic cells can be reprogrammed into pluripotent stem cells by introducing a combination of several transcription factors. The induced pluripotent stem (iPS) cells from a patient's somatic cells could be useful source of cells for drug discovery and cell transplantation therapies. However, most human iPS cells are made by viral vectors, such as retrovirus and lentivirus, which integrate the reprogramming factors into host genomes and may increase the risk of tumor formation. Studies of the mechanisms underlying the reprogramming and establishment of non-integration methods contribute evidence to resolve the safety concerns associated with iPS cells. On the other hand, patient-specific iPS cells have already been established and used for recapitulating disease pathology.

Human Induced Pluripotent Stem Cell-Derived Cardiomyocytes Afford New Opportunities in Inherited Cardiovascular Disease Modeling

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Daniel R. Bayzigitov

2016-01-01

Full Text Available Fundamental studies of molecular and cellular mechanisms of cardiovascular disease pathogenesis are required to create more effective and safer methods of their therapy. The studies can be carried out only when model systems that fully recapitulate pathological phenotype seen in patients are used. Application of laboratory animals for cardiovascular disease modeling is limited because of physiological differences with humans. Since discovery of induced pluripotency generating induced pluripotent stem cells has become a breakthrough technology in human disease modeling. In this review, we discuss a progress that has been made in modeling inherited arrhythmias and cardiomyopathies, studying molecular mechanisms of the diseases, and searching for and testing drug compounds using patient-specific induced pluripotent stem cell-derived cardiomyocytes.

The transformation suppressor gene Reck is required for postaxial patterning in mouse forelimbs

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Mako Yamamoto

2012-03-01

The membrane-anchored metalloproteinase-regulator RECK has been characterized as a tumor suppressor. Here we report that mice with reduced Reck-expression show limb abnormalities including right-dominant, forelimb-specific defects in postaxial skeletal elements. The forelimb buds of low-Reck mutants have an altered dorsal ectoderm with reduced Wnt7a and Igf2 expression, and hypotrophy in two signaling centers (i.e., ZPA and AER that are essential for limb outgrowth and patterning. Reck is abundantly expressed in the anterior mesenchyme in normal limb buds; mesenchyme-specific Reck inactivation recapitulates the low-Reck phenotype; and some teratogens downregulate Reck in mesenchymal cells. Our findings illustrate a role for Reck in the mesenchymal-epithelial interactions essential for mammalian development.

Bent bone dysplasia (BBD)-FGFR2 type: the radiologic manifestations in early gestation

Energy Technology Data Exchange (ETDEWEB)

Handa, Atsuhiko; Okajima, Yuka; Kurihara, Yasuyuki [St. Luke' s International Hospital, Department of Radiology, Tokyo (Japan); Izumi, Noriko; Yamanaka, Michiko [St. Luke' s International Hospital, Department of Integrated Women' s Health, Tokyo (Japan)

2016-02-15

Bent bone dysplasia-fibroblast growth factor receptor 2 type (BBD-FGFR2) is a recently identified skeletal dysplasia caused by specific FGFR2 mutations, characterized by craniosynostosis and prenatal bowing of the long bones. Only a few cases have been published. We report an affected fetus terminated at 21 weeks of gestation. The clinical and radiologic manifestations mostly recapitulate previous descriptions; however we suggest additional hallmarks of this disorder in early gestation. These hallmarks include distinctive short, thick clavicles and wavy ribs, as well as vertebral bodies that showed striking anteroposterior shortening. Femoral fractures were also present in our case. Although craniosynostosis is a hallmark of the disease, clinicians should be aware that craniosynostosis might not be readily apparent on plain films early in gestation. (orig.)

Complexity-aware simple modeling.

Science.gov (United States)

Gómez-Schiavon, Mariana; El-Samad, Hana

2018-02-26

Mathematical models continue to be essential for deepening our understanding of biology. On one extreme, simple or small-scale models help delineate general biological principles. However, the parsimony of detail in these models as well as their assumption of modularity and insulation make them inaccurate for describing quantitative features. On the other extreme, large-scale and detailed models can quantitatively recapitulate a phenotype of interest, but have to rely on many unknown parameters, making them often difficult to parse mechanistically and to use for extracting general principles. We discuss some examples of a new approach-complexity-aware simple modeling-that can bridge the gap between the small-scale and large-scale approaches. Copyright © 2018 Elsevier Ltd. All rights reserved.

The role of glucocorticoid, interleukin-1β, and antioxidants in prenatal stress effects on embryonic microglia.

Science.gov (United States)

Bittle, Jada; Stevens, Hanna E

2018-02-16

Maternal stress during pregnancy is associated with an increased risk of psychopathology in offspring. Resident immune cells of the brain, microglia, may be mediators of prenatal stress and altered neurodevelopment. Here, we demonstrate that neither the exogenous pro-inflammatory cytokine, interleukin-1β (IL-1β), nor the glucocorticoid hormone, corticosterone, recapitulated the full effects of prenatal stress on the morphology of microglial cells in the cortical plate of embryonic mice; IL-1β effects showed greater similarity to prenatal stress effects on microglia. Unexpectedly, oil vehicle alone, which has antioxidant properties, moderated the effects of prenatal stress on microglia. Microglia changes with prenatal stress were also sensitive to the antioxidant, N-acetylcysteine, suggesting redox dysregulation as a mechanism of prenatal stress.

First decade: TVA's first ten years of nuclear power plant design and construction experience

International Nuclear Information System (INIS)

Willis, W.F.

1978-01-01

This paper reviews the experience of the Tennessee Valley Authority's design and construction program for nuclear power plants in terms of schedule and capital costs in three separate phases. Phase one recapitulates the status of the nuclear power industry in 1966 and sets forth the assumptions used for estimating capital costs and projecting schedules for the first Tennessee Valley Authority units. Phase two describes what happened to the program in the hectic early 1970s in terms of expansion of scope (particularly for safety features), the dramatic increase in regulatory requirements, vendor problems, stretchout of project schedules, and unprecented inflation. Phase three addresses the assumptions used today in estimating schedules and plant costs for the next 10-year period. 7 figures, 7 tables

Combined Gluteus and Pudendal Thigh Flap Reconstruction of Vaginal Defects following Robotic Abdominoperineal Resection

Directory of Open Access Journals (Sweden)

Kasandra R. Dassoulas, MD

2017-09-01

Full Text Available Summary:. Low-lying rectal cancers are being treated more frequently with robotic-assisted abdominoperineal resection, obviating the need for laparotomy and the ability to raise vertical rectus abdominis musculocutaneous flaps. For female patients, posterior vaginectomy often accompanies the resection. Combined pudendal thigh flaps as an extension of bilateral gluteus advancement flaps allow for posterior vaginal resurfacing with thin pliable fasciocutaneous flaps, which rest on the gluteal flap soft-tissue bulk that obliterates the pelvic dead space. For patients with advanced cancers who have had neoadjuvant chemoradiation, the pudendal skin paddle can be planned more laterally to bring in healthier medial thigh skin. The donor incisions lie within the gluteal cleft and crease and groin creases recapitulating normal perineal anatomy and aesthetics.

The role of glioma stem cells in chemotherapy resistance and glioblastoma multiforme recurrence

Science.gov (United States)

Auffinger, Brenda; Spencer, Drew; Pytel, Peter; Ahmed, Atique U.; Lesniak, Maciej S.

2016-01-01

Glioma stem cells (GSCs) constitute a slow-dividing, small population within a heterogeneous glioblastoma. They are able to self-renew, recapitulate a whole tumor, and differentiate into other specific GBM subpopulations. Therefore, they have been held responsible for malignant relapse after primary standard therapy and the poor prognosis of recurrent GBM. The failure of current therapies to eliminate specific GSC subpopulations has been considered a major factor contributing to the inevitable recurrence in GBM patients following treatment. Here, we discuss the molecular mechanisms of chemoresistance of GSCs and the reasons why complete eradication of GSCs is so difficult to achieve. We will also describe the targeted therapies currently available towards GSCs and possible mechanisms to overcome such chemoresistance and avoid therapeutic relapse. PMID:26027432

Using induced pluripotent stem cells to explore genetic and epigenetic variation associated with Alzheimer's disease.

Science.gov (United States)

Imm, Jennifer; Kerrigan, Talitha L; Jeffries, Aaron; Lunnon, Katie

2017-11-01

It is thought that both genetic and epigenetic variation play a role in Alzheimer's disease initiation and progression. With the advent of somatic cell reprogramming into induced pluripotent stem cells it is now possible to generate patient-derived cells that are able to more accurately model and recapitulate disease. Furthermore, by combining this with recent advances in (epi)genome editing technologies, it is possible to begin to examine the functional consequence of previously nominated genetic variants and infer epigenetic causality from recently identified epigenetic variants. In this review, we explore the role of genetic and epigenetic variation in Alzheimer's disease and how the functional relevance of nominated loci can be investigated using induced pluripotent stem cells and (epi)genome editing techniques.

Truncating Homozygous Mutation of Carboxypeptidase E (CPE in a Morbidly Obese Female with Type 2 Diabetes Mellitus, Intellectual Disability and Hypogonadotrophic Hypogonadism.

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Suzanne I M Alsters

Full Text Available Carboxypeptidase E is a peptide processing enzyme, involved in cleaving numerous peptide precursors, including neuropeptides and hormones involved in appetite control and glucose metabolism. Exome sequencing of a morbidly obese female from a consanguineous family revealed homozygosity for a truncating mutation of the CPE gene (c.76_98del; p.E26RfsX68. Analysis detected no CPE expression in whole blood-derived RNA from the proband, consistent with nonsense-mediated decay. The morbid obesity, intellectual disability, abnormal glucose homeostasis and hypogonadotrophic hypogonadism seen in this individual recapitulates phenotypes in the previously described fat/fat and Cpe knockout mouse models, evidencing the importance of this peptide/hormone-processing enzyme in regulating body weight, metabolism, and brain and reproductive function in humans.

Limits on fundamental limits to computation.

Science.gov (United States)

Markov, Igor L

2014-08-14

An indispensable part of our personal and working lives, computing has also become essential to industries and governments. Steady improvements in computer hardware have been supported by periodic doubling of transistor densities in integrated circuits over the past fifty years. Such Moore scaling now requires ever-increasing efforts, stimulating research in alternative hardware and stirring controversy. To help evaluate emerging technologies and increase our understanding of integrated-circuit scaling, here I review fundamental limits to computation in the areas of manufacturing, energy, physical space, design and verification effort, and algorithms. To outline what is achievable in principle and in practice, I recapitulate how some limits were circumvented, and compare loose and tight limits. Engineering difficulties encountered by emerging technologies may indicate yet unknown limits.

Final environmental statement. Final addendum to Part II: Manufacture of floating nuclear power plants by Offshore Power Systems. DOCKET-STN--50-437

International Nuclear Information System (INIS)

1978-06-01

This Addendum to Part II of the Final Environmental Statement related to manufacture of floating nuclear power plants by Offshore Power Systems (OPS), NUREG-0056, issued September 1976, was prepared by the U.S. Nuclear Regulatory Commission (NRC), Office of Nuclear Reactor Regulation. The staff's basic evaluation is presented in NUREG-0056. The current Addendum provides further consideration of a number of topics discussed in NUREG-0056, particularly additional consideration of shore zone siting at estuarine and ocean regions. This Summary and Conclusions recapitulates and is cumulative for Part II of the FES and the current Addendum. Augmentations to the Summary and Conclusions presented in Part II of the FES and arising from the evaluations contained in this Addendum are italicized

Malaria in pregnancy: the relevance of animal models for vaccine development.

Science.gov (United States)

Doritchamou, Justin; Teo, Andrew; Fried, Michal; Duffy, Patrick E

2017-10-06

Malaria during pregnancy due to Plasmodium falciparum or P. vivax is a major public health problem in endemic areas, with P. falciparum causing the greatest burden of disease. Increasing resistance of parasites and mosquitoes to existing tools, such as preventive antimalarial treatments and insecticide-treated bed nets respectively, is eroding the partial protection that they offer to pregnant women. Thus, development of effective vaccines against malaria during pregnancy is an urgent priority. Relevant animal models that recapitulate key features of the pathophysiology and immunology of malaria in pregnant women could be used to accelerate vaccine development. This review summarizes available rodent and nonhuman primate models of malaria in pregnancy, and discusses their suitability for studies of biologics intended to prevent or treat malaria in this vulnerable population.

Online luminosity measurement at BES III

International Nuclear Information System (INIS)

Song Wenbo; Fu Chengdong; Mo Xiaohu; He Kanglin; Zhu Kejun; Li Fei; Zhao Shujun

2010-01-01

As a crucial parameter of both accelerator and detector, the realization of online luminosity measurement is of great importance. Several methods of luminosity measurement are recapitulated and the emphasis is laid on the algorithm of using e + e - and γγ final states. Taking into account the status at the beginning of the joint commissioning of detector and accelerator, the information from end cap electromagnetic calorimeter is used to select the good event. With the help of online Event filter, the luminosity is calculated and the monitoring of online cross section of hadron is realized. The preliminary results indicate that the online luminosity measurement is stable and its role for machine tuning and monitoring of the overall running status is indispensable. (authors)

Research program on radioactive wastes - Overview report for 2011

International Nuclear Information System (INIS)

Brander, S.

2012-01-01

This report for the Swiss Federal Office of Energy (SFOE) summarises the program's main points of interest and the work done in the year 2011 along with the results obtained. The aims of the program are recapitulated. The research program is co-ordinated by a working group comprising the Swiss Federal Office of Energy, the Swiss Federal Nuclear Safety Inspectorate ENSI, the Commission on Nuclear Waste Disposal and the Commission for Safety in Nuclear Installations, Some highlights of the research program are briefly described and discussed. Topics covered concern the marking of nuclear waste repositories, value judgement and opinion building, waste management as well as repository design, including dimensioning and monitoring systems, National and international co-operation is also discussed

Microfluidic 3D cell culture: potential application for tissue-based bioassays

Science.gov (United States)

Li, XiuJun (James); Valadez, Alejandra V.; Zuo, Peng; Nie, Zhihong

2014-01-01

Current fundamental investigations of human biology and the development of therapeutic drugs, commonly rely on two-dimensional (2D) monolayer cell culture systems. However, 2D cell culture systems do not accurately recapitulate the structure, function, physiology of living tissues, as well as highly complex and dynamic three-dimensional (3D) environments in vivo. The microfluidic technology can provide micro-scale complex structures and well-controlled parameters to mimic the in vivo environment of cells. The combination of microfluidic technology with 3D cell culture offers great potential for in vivo-like tissue-based applications, such as the emerging organ-on-a-chip system. This article will review recent advances in microfluidic technology for 3D cell culture and their biological applications. PMID:22793034

Molecular and functional aspects of menstruation in the macaque.

Science.gov (United States)

Brenner, Robert M; Slayden, Ov D

2012-12-01

Much of our understanding of the molecular control of menstruation arises from laboratory models that experimentally recapitulate some, but not all, aspects of uterine bleeding observed in women. These models include: in vitro culture of endometrial explants or isolated endometrial cells, transplantation of human endometrial tissue into immunodeficient mice and the induction of endometrial breakdown in appropriately pretreated mice. Each of these models has contributed to our understanding of molecular and cellular mechanisms of menstruation, but nonhuman primates, especially macaques, are the animal model of choice for evaluating therapies for menstrual disorders. In this chapter we review some basic aspects of menstruation, with special emphasis on the macaque model and its relevance to the clinical issues of irregular and heavy menstrual bleeding (HMB).

Adaptive Immunity to Francisella tularensis and Considerations for Vaccine Development

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Lydia M. Roberts

2018-04-01

Full Text Available Francisella tularensis is an intracellular bacterium that causes the disease tularemia. There are several subspecies of F. tularensis whose ability to cause disease varies in humans. The most virulent subspecies, tularensis, is a Tier One Select Agent and a potential bioweapon. Although considerable effort has made to generate efficacious tularemia vaccines, to date none have been licensed for use in the United States. Despite the lack of a tularemia vaccine, we have learned a great deal about the adaptive immune response the underlies protective immunity. Herein, we detail the animal models commonly used to study tularemia and their recapitulation of human disease, the field's current understanding of vaccine-mediated protection, and discuss the challenges associated with new vaccine development.

The Role of 3D Modelling and Printing in Orthopaedic Tissue Engineering: A Review of the Current Literature.

Science.gov (United States)

Shaunak, Shalin; Dhinsa, Baljinder S; Khan, Wasim S

2017-01-01

Orthopaedic surgery lends itself well to advances in technology. An area of interest and ongoing research is that of the production of scaffolds for use in trauma and elective surgery. 3D printing provides unprecedented accuracy in terms of micro- and macro-structure and geometry for scaffold production. It can also be utilised to construct scaffolds of a variety of different materials and more recently has allowed for the construction of bio-implants which recapitulate bone and cartilage tissue. This review seeks to look at the various methods of 3DP, the materials used, elements of functionality and design, as well as modifications to increase the biomechanics and bioactivity of 3DP scaffolds. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

In vitro propagation of endangered Dianthus taxa

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Marković Marija

2015-01-01

Full Text Available The review of recent researches regarding the in vitro culture of 30 endangered Dianthus taxa is presented in this paper. Various in vitro protocols developed for selected rare and threatened Dianthus taxa are analysed in order to provide a useful synthesis of the data obtained with the main principles, techniques and recommendations for futher research and practice. The recapitulated data presented in this review can be used as a tool for the micropropagation of other endangered Dianthus taxa, enabling their propagation and obtaining a sufficient amount of plants for reintroduction. In addition, the obtained results represent the basis for ex situ conservation of the investigated taxa, especially for medium-term and long-term conservation (cryopreservation. [Projekat Ministarstva nauke Republike Srbije, br. 43007

Regulation of Epithelial Morphogenesis by the G-Protein Coupled Receptor Mist and its Ligand Fog*

Science.gov (United States)

Manning, Alyssa J.; Peters, Kimberly A.; Peifer, Mark; Rogers, Stephen L.

2014-01-01

Epithelial morphogenesis is essential for shaping organs and tissues and for establishment of the three embryonic germ layers during gastrulation. Studies of gastrulation in Drosophila have provided insight into how epithelial morphogenesis is governed by developmental patterning mechanisms. We developed an assay to recapitulate morphogenetic shape changes in individual cultured cells, and used RNAi-based screening to identify Mist, a Drosophila G protein-coupled receptor (GPCR) that transduces signals from the secreted ligand Folded gastrulation (Fog) in cultured cells. Mist functioned in Fog-dependent embryonic morphogenesis, and the transcription factor Snail regulated expression of mist in zygotes. Our data revealed how a cell fate transcriptional program acts through a ligand-GPCR pair to stimulate epithelial morphogenetic shape changes. PMID:24222713

High content analysis of phagocytic activity and cell morphology with PuntoMorph

DEFF Research Database (Denmark)

Al-Ali, Hassan; Gao, Han; Dalby-Hansen, Camilla

2017-01-01

methods for quantifying phagocytic activity in multiple dimensions including speed, accuracy, and resolution. Conclusions We provide a framework to facilitate the development of high content assays suitable for drug screening. For convenience, we implemented our algorithm in a standalone software package...... with image-based quantification of phagocytic activity. New method We present a robust algorithm and cell-based assay system for high content analysis of phagocytic activity. The method utilizes fluorescently labeled beads as a phagocytic substrate with defined physical properties. The algorithm employs...... content screening. Results We tested our assay system using microglial cultures. Our results recapitulated previous findings on the effects of microglial stimulation on cell morphology and phagocytic activity. Moreover, our cell-level analysis revealed that the two phenotypes associated with microglial...

Compton-heated winds and coronae above accretion disks. II. Instability and oscillations

International Nuclear Information System (INIS)

Shields, G.A.; Mckee, C.F.; Lin, D.N.C.; Begelman, M.C.; California Univ., Berkeley; California Univ., Santa Cruz; Colorado Univ., Boulder)

1986-01-01

The stability and evolution of windy accretion disks is investigated in detail. The basic disk evolution equations are briefly recapitulated, and an idealized analytic treatment of the wind and viscosity is used to show that steady disk flow is indeed unstable for sufficiently large ratio of the mass loss rate in the wind to the central accretion rate. Numerical solutions for a more realistic and appropriate expression for the mass loss rate and the standard ad hoc alpha model prescription for the viscosity are presented. The application of these results to real systems with Compton-heated winds is discussed, and a general formula for the oscillation period is given. The prediction is compared with observed periodic behavior of Galactic X-ray sources and AGNs. 17 references

Chromatin Constrains the Initiation and Elongation of DNA Replication.

Science.gov (United States)

Devbhandari, Sujan; Jiang, Jieqing; Kumar, Charanya; Whitehouse, Iestyn; Remus, Dirk

2017-01-05

Eukaryotic chromosomal DNA is faithfully replicated in a complex series of cell-cycle-regulated events that are incompletely understood. Here we report the reconstitution of DNA replication free in solution with purified proteins from the budding yeast Saccharomyces cerevisiae. The system recapitulates regulated bidirectional origin activation; synthesis of leading and lagging strands by the three replicative DNA polymerases Pol α, Pol δ, and Pol ε; and canonical maturation of Okazaki fragments into continuous daughter strands. We uncover a dual regulatory role for chromatin during DNA replication: promoting origin dependence and determining Okazaki fragment length by restricting Pol δ progression. This system thus provides a functional platform for the detailed mechanistic analysis of eukaryotic chromosome replication. Copyright © 2017 Elsevier Inc. All rights reserved.

Novel multiscale modeling tool applied to Pseudomonas aeruginosa biofilm formation.

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Matthew B Biggs

Full Text Available Multiscale modeling is used to represent biological systems with increasing frequency and success. Multiscale models are often hybrids of different modeling frameworks and programming languages. We present the MATLAB-NetLogo extension (MatNet as a novel tool for multiscale modeling. We demonstrate the utility of the tool with a multiscale model of Pseudomonas aeruginosa biofilm formation that incorporates both an agent-based model (ABM and constraint-based metabolic modeling. The hybrid model correctly recapitulates oxygen-limited biofilm metabolic activity and predicts increased growth rate via anaerobic respiration with the addition of nitrate to the growth media. In addition, a genome-wide survey of metabolic mutants and biofilm formation exemplifies the powerful analyses that are enabled by this computational modeling tool.

Novel multiscale modeling tool applied to Pseudomonas aeruginosa biofilm formation.

Science.gov (United States)

Biggs, Matthew B; Papin, Jason A

2013-01-01

Multiscale modeling is used to represent biological systems with increasing frequency and success. Multiscale models are often hybrids of different modeling frameworks and programming languages. We present the MATLAB-NetLogo extension (MatNet) as a novel tool for multiscale modeling. We demonstrate the utility of the tool with a multiscale model of Pseudomonas aeruginosa biofilm formation that incorporates both an agent-based model (ABM) and constraint-based metabolic modeling. The hybrid model correctly recapitulates oxygen-limited biofilm metabolic activity and predicts increased growth rate via anaerobic respiration with the addition of nitrate to the growth media. In addition, a genome-wide survey of metabolic mutants and biofilm formation exemplifies the powerful analyses that are enabled by this computational modeling tool.

Laminin promotes vascular network formation in 3D in vitro collagen scaffolds by regulating VEGF uptake.

Science.gov (United States)

Stamati, Katerina; Priestley, John V; Mudera, Vivek; Cheema, Umber

2014-09-10

Angiogenesis is an essential neovascularisation process, which if recapitulated in 3D in vitro, will provide better understanding of endothelial cell (EC) behaviour. Various cell types and growth factors are involved, with vascular endothelial growth factor (VEGF) and its receptors VEGFR1 and VEGFR2 key components. We were able to control the aggregation pattern of ECs in 3D collagen hydrogels, by varying the matrix composition and/or having a source of cells signalling angiogenic proteins. These aggregation patterns reflect the different developmental pathways that ECs take to form different sized tubular structures. Cultures with added laminin and thus increased expression of α6 integrin showed a significant increase (p3D. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

Optic neuritis with residual tunnel vision in perchloroethylene toxicity.

Science.gov (United States)

Onofrj, M; Thomas, A; Paci, C; Rotilio, D

1998-01-01

In a 57-year-old female owner of a dry-cleaning shop, we describe the association of severe bilateral optic neuritis with unexpectedly high concentrations of perchloroethylene/metabolites in the blood and of chloroform in urine. Visual disturbances consisted of complete blindness for 9 days in the left eye, for 11 days in the right eye, with bright phosphenes and pain on eye rotation. Only central (2-3 degrees radius) vision recovered in the following months. Although environmental concentrations of perchloroethylene were within normal limits, we measured five-fold increases in vapors emitted when ironing freshly dry-cleaned fabrics, and suggest that inhalation of perchloroethylene vapors was the cause of this case of ocular nerve toxicity, recapitulating a previous report of major perchloroethylene toxicity.

Molecular biology of breast cancer metastasis Molecular expression of vascular markers by aggressive breast cancer cells

International Nuclear Information System (INIS)

Hendrix, Mary JC; Seftor, Elisabeth A; Kirschmann, Dawn A; Seftor, Richard EB

2000-01-01

During embryogenesis, the formation of primary vascular networks occurs via the processes of vasculogenesis and angiogenesis. In uveal melanoma, vasculogenic mimicry describes the 'embryonic-like' ability of aggressive, but not nonaggressive, tumor cells to form networks surrounding spheroids of tumor cells in three-dimensional culture; these recapitulate the patterned networks seen in patients' aggressive tumors and correlates with poor prognosis. The molecular profile of these aggressive tumor cells suggests that they have a deregulated genotype, capable of expressing vascular phenotypes. Similarly, the embryonic-like phenotype expressed by the aggressive human breast cancer cells is associated with their ability to express a variety of vascular markers. These studies may offer new insights for consideration in breast cancer diagnosis and therapeutic intervention strategies

Geometric Lie algebra in matter, arts and mathematics with incubation of the periodic systems of the elements

Science.gov (United States)

Trell, Erik; Edeagu, Samuel; Animalu, Alexander

2017-01-01

From a brief recapitulation of the foundational works of Marius Sophus Lie and Herrmann Günther Grassmann, and including missing African links, a rhapsodic survey is made of the straight line of extension and existence that runs as the very fibre of generation and creation throughout Nature's all utterances, which must therefore ultimately be the web of Reality itself of which the Arts and Sciences are interpreters on equal explorer terms. Assuming their direct approach, the straight line and its archaic and algebraic and artistic bearings and convolutions have been followed towards their inner reaches, which earlier resulted in a retrieval of the baryon and meson elementary particles and now equally straightforward the electron geodesics and the organic build of the periodic system of the elements.

Novel and Experimental Therapies in Chronic Pancreatitis.

Science.gov (United States)

Jagannath, Soumya; Garg, Pramod Kumar

2017-07-01

Chronic pancreatitis (CP) is a progressive inflammatory disease of the pancreas. The currently available treatment of CP is aimed at controlling symptoms and managing complications. Unfortunately, no specific treatment is available to halt the progression of the disease process because the pathophysiological perturbations in CP are not well understood. In this review, we discuss various therapeutic targets and investigational agents acting on these targets. Among these, therapies modulating immune cells and those acting on pancreatic stellate cells appear promising and may translate into clinical benefit in near future. However, these experimental therapies are mostly in animal models and they do not recapitulate all aspects of human disease. Still they may be beneficial in developing effective therapeutic modalities to curb inflammation in chronic pancreatitis.

Matematik for Ingeniører

DEFF Research Database (Denmark)

Hellesen, Bjarne; Larsen, Mogens Oddershede

important basics are recapitulated, such that readers with mathematics at level B should be able to catch up.---------- ---------- --------------------GENERAL FOR ALL 3 VOLUMES. Most topics are accompanied by numerical methods (and algorithms), which are useful for an engineer and helps the mathematical...... starts with the most indispensable topics, which we try to explain in an intuitive and practical way by graphs and examples. Definitions and theorems are formulated precisely, and most of the theorems are proved. Later in the chapter there are some supplementary sections containing more peripheral topics...... VARIABEL (page 1) >>>>> 1.1 Funktionsbegrebet. 1.2 Graensevaerdi. 1.3 Kontinuitet. 1.4 Differentiation. 1.5 Integration. 1.6 Numerisk integration. 1A Praecis definition af "graensevaerdi". 1B Uniform kontinuitet. -- Opgaver. ---------- ---------- ---------- ---------- ---------- ---------- ----------2...

Humanized mice recapitulate key features of HIV-1 infection: a novel concept using long-acting anti-retroviral drugs for treating HIV-1.

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Marc Nischang

Full Text Available BACKGROUND: Humanized mice generate a lymphoid system of human origin subsequent to transplantation of human CD34+ cells and thus are highly susceptible to HIV infection. Here we examined the efficacy of antiretroviral treatment (ART when added to food pellets, and of long-acting (LA antiretroviral compounds, either as monotherapy or in combination. These studies shall be inspiring for establishing a gold standard of ART, which is easy to administer and well supported by the mice, and for subsequent studies such as latency. Furthermore, they should disclose whether viral breakthrough and emergence of resistance occurs similar as in HIV-infected patients when ART is insufficient. METHODS/PRINCIPAL FINDINGS: NOD/shi-scid/γ(cnull (NOG mice were used in all experimentations. We first performed pharmacokinetic studies of the drugs used, either added to food pellets (AZT, TDF, 3TC, RTV or in a LA formulation that permitted once weekly subcutaneous administration (TMC278: non-nucleoside reverse transcriptase inhibitor, TMC181: protease inhibitor. A combination of 3TC, TDF and TMC278-LA or 3TC, TDF, TMC278-LA and TMC181-LA suppressed the viral load to undetectable levels in 15/19 (79% and 14/14 (100% mice, respectively. In successfully treated mice, subsequent monotherapy with TMC278-LA resulted in viral breakthrough; in contrast, the two LA compounds together prevented viral breakthrough. Resistance mutations matched the mutations most commonly observed in HIV patients failing therapy. Importantly, viral rebound after interruption of ART, presence of HIV DNA in successfully treated mice and in vitro reactivation of early HIV transcripts point to an existing latent HIV reservoir. CONCLUSIONS/SIGNIFICANCE: This report is a unique description of multiple aspects of HIV infection in humanized mice that comprised efficacy testing of various treatment regimens, including LA compounds, resistance mutation analysis as well as viral rebound after treatment interruption. Humanized mice will be highly valuable for exploring the antiviral potency of new compounds or compounds targeting the latent HIV reservoir.

Influence of industrial exhalations on the fertility of ground and on the yields of agricultural plants: a recapitulation of the attained results

Energy Technology Data Exchange (ETDEWEB)

Kozel, J; Maly, V

1964-01-01

Deposition of dust and ambient concentrations of SO2 were measured around industrial areas in Czechoslovakia in 1961 and 1962. The amount of surface-adhered material and the SO3 content of plant ashes was also measured. Chemical analyses of soils in the areas were also carried out. Dimunition of agricultural productivity was documented. Maize and beans were the crops most affected by air pollution, followed by sugar beets, cereals, (wheat, oats and barley) in order of decreasing effect. 24 references, 4 figures, 5 tables.

Interspecific hybridization, polyploidization, and backcross of Brassica oleracea var. alboglabra with B. rapa var. purpurea morphologically recapitulate the evolution of Brassica vegetables.

Science.gov (United States)

Zhang, Xiaohui; Liu, Tongjin; Li, Xixiang; Duan, Mengmeng; Wang, Jinglei; Qiu, Yang; Wang, Haiping; Song, Jiangping; Shen, Di

2016-01-04

Brassica oleracea and B. rapa are two important vegetable crops. Both are composed of dozens of subspecies encompassing hundreds of varieties and cultivars. Synthetic B. napus with these two plants has been used extensively as a research model for the investigation of allopolyploid evolution. However, the mechanism underlying the explosive evolution of hundreds of varieties of B. oleracea and B. rapa within a short period is poorly understood. In the present study, interspecific hybridization between B. oleracea var. alboglabra and B. rapa var. purpurea was performed. The backcross progeny displayed extensive morphological variation, including some individuals that phenocopied subspecies other than their progenitors. Numerous interesting novel phenotypes and mutants were identified among the backcross progeny. The chromosomal recombination between the A and C genomes and the chromosomal asymmetric segregation were revealed using Simple Sequence Repeats (SSR) markers. These findings provide direct evidence in support of the hypothesis that interspecific hybridization and backcrossing have played roles in the evolution of the vast variety of vegetables among these species and suggest that combination of interspecific hybridization and backcrossing may facilitate the development of new mutants and novel phenotypes for both basic research and the breeding of new vegetable crops.

Low dose rectal inoculation of rhesus macaques by SIV SME660 or SIV MAC251 recapitulates human mucosal infection by HIV-1

Energy Technology Data Exchange (ETDEWEB)

Koraber, Bette [Los Alamos National Laboratory; Perelson, Alan [Los Alamos National Laboratory; Hraber, Peter [Los Alamos National Laboratory; Giorgi, E [Los Alamos National Laboratory; Bhattacharya, T [Los Alamos National Laboratory

2009-01-01

Recently, we developed a novel approach to the identification of transmitted or early founder HIV -1 genomes in acutely infected humans based on single genome amplification and sequencing. Here we tested this approach in 18 acutely infected Indian rhesus macaques to determine the molecular features of SIV transmission. Animals were inoculated intrarectally (IR) or intravenously (IV) with stocks of SIVmac251 or SIVsmE660 that exhibited sequence diversity typical of early-chronic HIV -1 infection. 987 full-length SIV env sequences (median of 48 per animal) were determined from plasma virion RNA one to five weeks after infection. IR inoculation was followed by productive infection by one or few viruses (median 1; range 1-5) that diversified randomly with near star-like phylogeny and a Poisson distribution of mutations. Consensus viral sequences from ramp-up and peak viremia were identical to viruses found in the inocula or differed from them by only one or few nuc1eotides, providing direct evidence that early plasma viral sequences coalesce to transmitted/founder virus( es). IV infection was approximately 10,000-fold more efficient than IR infection, and viruses transmitted by either route represented the full genetic spectra of the inocula. These findings identify key similarities in mucosal transmission and early diversification between SIV and HIV -1.

Recapitulation of the Research Leading to the Treatise on "Physical Hydrodynamics with Applications to Dynamical Meteorology" as recorded by V. Bjerknes, 1933

OpenAIRE

Berger, Wolfgang H

2007-01-01

Vilhelm Frimann Koren Bjerknes, Norwegian physicist (1862-1951), was a central figure in the pioneering stage of modern meteorology and oceanography. His meteorological theories (especially with regard to cyclogenesis along the polar front) helped establish the basis for weather forecasting in temperate and high latitudes. His mathematical treatment of water motions in the sea helped establish the foundations for dynamic oceanography. Bjerknes was the leading figure of the "Bergen Sc...

Structural Immaturity of Human iPSC-Derived Cardiomyocytes: In Silico Investigation of Effects on Function and Disease Modeling

Science.gov (United States)

Koivumäki, Jussi T.; Naumenko, Nikolay; Tuomainen, Tomi; Takalo, Jouni; Oksanen, Minna; Puttonen, Katja A.; Lehtonen, Šárka; Kuusisto, Johanna; Laakso, Markku; Koistinaho, Jari; Tavi, Pasi

2018-01-01

Background: Human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) have emerged as a promising experimental tool for translational heart research and drug development. However, their usability as a human adult cardiomyocyte model is limited by their functional immaturity. Our aim is to analyse quantitatively those characteristics and how they differ from adult CMs. Methods and Results: We have developed a novel in silico model with all essential functional electrophysiology and calcium handling features of hiPSC-CMs. Importantly, the virtual cell recapitulates the immature intracellular ion dynamics that are characteristic for hiPSC-CMs, as quantified based our in vitro imaging data. The strong “calcium clock” is a source for a dual function of excitation-contraction coupling in hiPSC-CMs: action potential and calcium transient morphology vary substantially depending on the activation sequence of underlying ionic currents and fluxes that is altered in spontaneous vs. paced mode. Furthermore, parallel simulations with hiPSC-CM and adult cardiomyocyte models demonstrate the central differences. Results indicate that hiPSC-CMs translate poorly the disease specific phenotypes of Brugada syndrome, long QT Syndrome and catecholaminergic polymorphic ventricular tachycardia, showing less robustness and greater tendency for arrhythmic events than adult CMs. Based on a comparative sensitivity analysis, hiPSC-CMs share some features with adult CMs, but are still functionally closer to prenatal CMs than adult CMs. A database analysis of 3000 hiPSC-CM model variants suggests that hiPSC-CMs recapitulate poorly fundamental physiological properties of adult CMs. Single modifications do not appear to solve this problem, which is mostly contributed by the immaturity of intracellular calcium handling. Conclusion: Our data indicates that translation of findings from hiPSC-CMs to human disease should be made with great caution. Furthermore, we established a

Modelling neurodegenerative diseases in vitro: Recent advances in 3D iPSC technologies

Directory of Open Access Journals (Sweden)

Elodie J Siney

2018-03-01

Full Text Available The discovery of induced pluripotent stem cells (iPSC 12 years ago has fostered the development of innovative patient-derived in vitro models for better understanding of disease mechanisms. This is particularly relevant to neurodegenerative diseases, where availability of live human brain tissue for research is limited and post-mortem interval changes influence readouts from autopsy-derived human tissue. Hundreds of iPSC lines have now been prepared and banked, thanks to several large scale initiatives and cell banks. Patient- or engineered iPSC-derived neural models are now being used to recapitulate cellular and molecular aspects of a variety of neurodegenerative diseases, including early and pre-clinical disease stages. The broad relevance of these models derives from the availability of a variety of differentiation protocols to generate disease-specific cell types and the manipulation to either introduce or correct disease-relevant genetic modifications. Moreover, the use of chemical and physical three-dimensional (3D matrices improves control over the extracellular environment and cellular organization of the models. These iPSC-derived neural models can be utilised to identify target proteins and, importantly, provide high-throughput screening for drug discovery. Choosing Alzheimer’s disease (AD as an example, this review describes 3D iPSC-derived neural models and their advantages and limitations. There is now a requirement to fully characterise and validate these 3D iPSC-derived neural models as a viable research tool that is capable of complementing animal models of neurodegeneration and live human brain tissue. With further optimization of differentiation, maturation and aging protocols, as well as the 3D cellular organisation and extracellular matrix to recapitulate more closely, the molecular extracellular-environment of the human brain, 3D iPSC-derived models have the potential to deliver new knowledge, enable discovery of novel

Engineering complex orthopaedic tissues via strategic biomimicry.

Science.gov (United States)

Qu, Dovina; Mosher, Christopher Z; Boushell, Margaret K; Lu, Helen H

2015-03-01

The primary current challenge in regenerative engineering resides in the simultaneous formation of more than one type of tissue, as well as their functional assembly into complex tissues or organ systems. Tissue-tissue synchrony is especially important in the musculoskeletal system, wherein overall organ function is enabled by the seamless integration of bone with soft tissues such as ligament, tendon, or cartilage, as well as the integration of muscle with tendon. Therefore, in lieu of a traditional single-tissue system (e.g., bone, ligament), composite tissue scaffold designs for the regeneration of functional connective tissue units (e.g., bone-ligament-bone) are being actively investigated. Closely related is the effort to re-establish tissue-tissue interfaces, which is essential for joining these tissue building blocks and facilitating host integration. Much of the research at the forefront of the field has centered on bioinspired stratified or gradient scaffold designs which aim to recapitulate the structural and compositional inhomogeneity inherent across distinct tissue regions. As such, given the complexity of these musculoskeletal tissue units, the key question is how to identify the most relevant parameters for recapitulating the native structure-function relationships in the scaffold design. Therefore, the focus of this review, in addition to presenting the state-of-the-art in complex scaffold design, is to explore how strategic biomimicry can be applied in engineering tissue connectivity. The objective of strategic biomimicry is to avoid over-engineering by establishing what needs to be learned from nature and defining the essential matrix characteristics that must be reproduced in scaffold design. Application of this engineering strategy for the regeneration of the most common musculoskeletal tissue units (e.g., bone-ligament-bone, muscle-tendon-bone, cartilage-bone) will be discussed in this review. It is anticipated that these exciting efforts will

Brain infusion of α-synuclein oligomers induces motor and non-motor Parkinson's disease-like symptoms in mice.

Science.gov (United States)

Fortuna, Juliana T S; Gralle, Matthias; Beckman, Danielle; Neves, Fernanda S; Diniz, Luan P; Frost, Paula S; Barros-Aragão, Fernanda; Santos, Luís E; Gonçalves, Rafaella A; Romão, Luciana; Zamberlan, Daniele C; Soares, Felix A A; Braga, Carolina; Foguel, Debora; Gomes, Flávia C A; De Felice, Fernanda G; Ferreira, Sergio T; Clarke, Julia R; Figueiredo, Cláudia P

2017-08-30

Parkinson's disease (PD) is characterized by motor dysfunction, which is preceded by a number of non-motor symptoms including olfactory deficits. Aggregation of α-synuclein (α-syn) gives rise to Lewy bodies in dopaminergic neurons and is thought to play a central role in PD pathology. However, whether amyloid fibrils or soluble oligomers of α-syn are the main neurotoxic species in PD remains controversial. Here, we performed a single intracerebroventricular (i.c.v.) infusion of α-syn oligomers (α-SYOs) in mice and evaluated motor and non-motor symptoms. Familiar bedding and vanillin essence discrimination tasks showed that α-SYOs impaired olfactory performance of mice, and decreased TH and dopamine levels in the olfactory bulb early after infusion. The olfactory deficit persisted until 45days post-infusion (dpi). α- SYO-infused mice behaved normally in the object recognition and forced swim tests, but showed increased anxiety-like behavior in the open field and elevated plus maze tests 20 dpi. Finally, administration of α-SYOs induced late motor impairment in the pole test and rotarod paradigms, along with reduced TH and dopamine content in the caudate putamen, 45 dpi. Reduced number of TH-positive cells was also seen in the substantia nigra of α-SYO-injected mice compared to control. In conclusion, i.c.v. infusion of α-SYOs recapitulated some of PD-associated non-motor symptoms, such as increased anxiety and olfactory dysfunction, but failed to recapitulate memory impairment and depressive-like behavior typical of the disease. Moreover, α-SYOs i.c.v. administration induced motor deficits and loss of TH and dopamine levels, key features of PD. Results point to α-syn oligomers as the proximal neurotoxins responsible for early non-motor and motor deficits in PD and suggest that the i.c.v. infusion model characterized here may comprise a useful tool for identification of PD novel therapeutic targets and drug screening. Copyright © 2017 Elsevier B.V. All

Physical study of the 'snow flake' version of the reactor EL-3 (1963); Etude physique de la version ''cristal de neige'' de la pile EL-3 (1963)

Energy Technology Data Exchange (ETDEWEB)

Abillon, E; Genthon, J P [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1963-07-01

A systematic study has been made of the different thermodynamic and neutronic aspects of various versions of the 'snow flake' likely to fulfil the aims which were set out (improvement of the reactivity, of the experimental volume, improvement in the working conditions of EL-3). After this systematic study, a choice was made in principle of one version amongst the several available (solutions using 8 or 10 pencils-various methods of heat transfer: corrugation, cartridges which may or may not be filled with helium... etc., variable enrichments... ). The choice is that of a version which can already at the present be considered as feasible, which represents already a notable improvement of the pile and which does not imply the existence of a major problem as far as the possible change-over later to an improved version is concerned. This choice defines a fuel element and a configuration for the core. A detailed recapitulation has been made of all the research being carried out for the possible solutions in this particular case. (authors) [French] On a etudie systematiquement les differents aspects thermodynamiques et neutroniques de diverses versions 'cristal de neige' susceptibles de remplir les buts fixes (amelioration en reactivite, en volume experimental, amelioration des problemes d'exploitation de EL-3). Apres cette etude systematique, on a procede au choix de principe d'une version parmi les differentes solutions possibles (solutions a 8 ou 10 crayons - possibilite de transfert de chaleur divers: corrugations, cartouches remplies He ou non.... etc., enrichissements variables... ). Ce choix est celui d'une version qu'on peut juger viable des aujourd'hui, qui represente deja une amelioration importante de la pile et qui n'implique pas de probleme majeur quant au passage ulterieur et eventuel a une version plus amelioree. Ce choix definit un element combustible, et une configuration de coeur. On a recapitule et detaille sur ce cas particulier de pile les etudes

Mouse transgenesis identifies conserved functional enhancers and cis-regulatory motif in the vertebrate LIM homeobox gene Lhx2 locus.

Directory of Open Access Journals (Sweden)

Alison P Lee

Full Text Available The vertebrate Lhx2 is a member of the LIM homeobox family of transcription factors. It is essential for the normal development of the forebrain, eye, olfactory system and liver as well for the differentiation of lymphoid cells. However, despite the highly restricted spatio-temporal expression pattern of Lhx2, nothing is known about its transcriptional regulation. In mammals and chicken, Crb2, Dennd1a and Lhx2 constitute a conserved linkage block, while the intervening Dennd1a is lost in the fugu Lhx2 locus. To identify functional enhancers of Lhx2, we predicted conserved noncoding elements (CNEs in the human, mouse and fugu Crb2-Lhx2 loci and assayed their function in transgenic mouse at E11.5. Four of the eight CNE constructs tested functioned as tissue-specific enhancers in specific regions of the central nervous system and the dorsal root ganglia (DRG, recapitulating partial and overlapping expression patterns of Lhx2 and Crb2 genes. There was considerable overlap in the expression domains of the CNEs, which suggests that the CNEs are either redundant enhancers or regulating different genes in the locus. Using a large set of CNEs (810 CNEs associated with transcription factor-encoding genes that express predominantly in the central nervous system, we predicted four over-represented 8-mer motifs that are likely to be associated with expression in the central nervous system. Mutation of one of them in a CNE that drove reporter expression in the neural tube and DRG abolished expression in both domains indicating that this motif is essential for expression in these domains. The failure of the four functional enhancers to recapitulate the complete expression pattern of Lhx2 at E11.5 indicates that there must be other Lhx2 enhancers that are either located outside the region investigated or divergent in mammals and fishes. Other approaches such as sequence comparison between multiple mammals are required to identify and characterize such enhancers.

Bile acid-induced necrosis in primary human hepatocytes and in patients with obstructive cholestasis

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Woolbright, Benjamin L.; Dorko, Kenneth [Department of Pharmacology, Toxicology & Therapeutics, University of Kansas Medical Center, Kansas City, KS (United States); Antoine, Daniel J.; Clarke, Joanna I. [MRC Centre for Drug Safety Science, Department of Molecular and Clinical Pharmacology, Institute of Translational Medicine, University of Liverpool, Liverpool (United Kingdom); Gholami, Parviz [Department of Internal Medicine, University of Kansas Medical Center, Kansas City, KS (United States); Li, Feng [Department of Pharmacology, Toxicology & Therapeutics, University of Kansas Medical Center, Kansas City, KS (United States); Kumer, Sean C.; Schmitt, Timothy M.; Forster, Jameson [Department of Surgery, University of Kansas Medical Center, Kansas City, KS (United States); Fan, Fang [Department of Pathology, University of Kansas Medical Center, Kansas City, KS (United States); Jenkins, Rosalind E.; Park, B. Kevin [MRC Centre for Drug Safety Science, Department of Molecular and Clinical Pharmacology, Institute of Translational Medicine, University of Liverpool, Liverpool (United Kingdom); Hagenbuch, Bruno [Department of Pharmacology, Toxicology & Therapeutics, University of Kansas Medical Center, Kansas City, KS (United States); Olyaee, Mojtaba [Department of Internal Medicine, University of Kansas Medical Center, Kansas City, KS (United States); Jaeschke, Hartmut, E-mail: hjaeschke@kumc.edu [Department of Pharmacology, Toxicology & Therapeutics, University of Kansas Medical Center, Kansas City, KS (United States)

2015-03-15

Accumulation of bile acids is a major mediator of cholestatic liver injury. Recent studies indicate bile acid composition between humans and rodents is dramatically different, as humans have a higher percent of glycine conjugated bile acids and increased chenodeoxycholate content, which increases the hydrophobicity index of bile acids. This increase may lead to direct toxicity that kills hepatocytes, and promotes inflammation. To address this issue, this study assessed how pathophysiological concentrations of bile acids measured in cholestatic patients affected primary human hepatocytes. Individual bile acid levels were determined in serum and bile by UPLC/QTOFMS in patients with extrahepatic cholestasis with, or without, concurrent increases in serum transaminases. Bile acid levels increased in serum of patients with liver injury, while biliary levels decreased, implicating infarction of the biliary tracts. To assess bile acid-induced toxicity in man, primary human hepatocytes were treated with relevant concentrations, derived from patient data, of the model bile acid glycochenodeoxycholic acid (GCDC). Treatment with GCDC resulted in necrosis with no increase in apoptotic parameters. This was recapitulated by treatment with biliary bile acid concentrations, but not serum concentrations. Marked elevations in serum full-length cytokeratin-18, high mobility group box 1 protein (HMGB1), and acetylated HMGB1 confirmed inflammatory necrosis in injured patients; only modest elevations in caspase-cleaved cytokeratin-18 were observed. These data suggest human hepatocytes are more resistant to human-relevant bile acids than rodent hepatocytes, and die through necrosis when exposed to bile acids. These mechanisms of cholestasis in humans are fundamentally different to mechanisms observed in rodent models. - Highlights: • Cholestatic liver injury is due to cytoplasmic bile acid accumulation in hepatocytes. • Primary human hepatocytes are resistant to BA-induced injury

Engineering Complex Orthopaedic Tissues via Strategic Biomimicry

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Qu, Dovina; Mosher, Christopher Z.; Boushell, Margaret K.; Lu, Helen H.

2014-01-01

The primary current challenge in regenerative engineering resides in the simultaneous formation of more than one type of tissue, as well as their functional assembly into complex tissues or organ systems. Tissue-tissue synchrony is especially important in the musculoskeletal system, whereby overall organ function is enabled by the seamless integration of bone with soft tissues such as ligament, tendon, or cartilage, as well as the integration of muscle with tendon. Therefore, in lieu of a traditional single-tissue system (e.g. bone, ligament), composite tissue scaffold designs for the regeneration of functional connective tissue units (e.g. bone-ligament-bone) are being actively investigated. Closely related is the effort to re-establish tissue-tissue interfaces, which is essential for joining these tissue building blocks and facilitating host integration. Much of the research at the forefront of the field has centered on bioinspired stratified or gradient scaffold designs which aim to recapitulate the structural and compositional inhomogeneity inherent across distinct tissue regions. As such, given the complexity of these musculoskeletal tissue units, the key question is how to identify the most relevant parameters for recapitulating the native structure-function relationships in the scaffold design. Therefore, the focus of this review, in addition to presenting the state-of-the-art in complex scaffold design, is to explore how strategic biomimicry can be applied in engineering tissue connectivity. The objective of strategic biomimicry is to avoid over-engineering by establishing what needs to be learned from nature and defining the essential matrix characteristics that must be reproduced in scaffold design. Application of this engineering strategy for the regeneration of the most common musculoskeletal tissue units (e.g. bone-ligament-bone, muscle-tendon-bone, cartilage-bone) will be discussed in this review. It is anticipated that these exciting efforts will

Standardisation of oxygen exposure in the development of mouse models for bronchopulmonary dysplasia

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Claudio Nardiello

2017-02-01

Full Text Available Progress in developing new therapies for bronchopulmonary dysplasia (BPD is sometimes complicated by the lack of a standardised animal model. Our objective was to develop a robust hyperoxia-based mouse model of BPD that recapitulated the pathological perturbations to lung structure noted in infants with BPD. Newborn mouse pups were exposed to a varying fraction of oxygen in the inspired air (FiO2 and a varying window of hyperoxia exposure, after which lung structure was assessed by design-based stereology with systemic uniform random sampling. The efficacy of a candidate therapeutic intervention using parenteral nutrition was evaluated to demonstrate the utility of the standardised BPD model for drug discovery. An FiO2 of 0.85 for the first 14 days of life decreased total alveoli number and concomitantly increased alveolar septal wall thickness, which are two key histopathological characteristics of BPD. A reduction in FiO2 to 0.60 or 0.40 also caused a decrease in the total alveoli number, but the septal wall thickness was not impacted. Neither a decreasing oxygen gradient (from FiO2 0.85 to 0.21 over the first 14 days of life nor an oscillation in FiO2 (between 0.85 and 0.40 on a 24 h:24 h cycle had an appreciable impact on lung development. The risk of missing beneficial effects of therapeutic interventions at FiO2 0.85, using parenteral nutrition as an intervention in the model, was also noted, highlighting the utility of lower FiO2 in selected studies, and underscoring the need to tailor the model employed to the experimental intervention. Thus, a state-of-the-art BPD animal model that recapitulates the two histopathological hallmark perturbations to lung architecture associated with BPD is described. The model presented here, where injurious stimuli have been systematically evaluated, provides a most promising approach for the development of new strategies to drive postnatal lung maturation in affected infants.

Modularity in developmental biology and artificial organs: a missing concept in tissue engineering.

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Lenas, Petros; Luyten, Frank P; Doblare, Manuel; Nicodemou-Lena, Eleni; Lanzara, Andreina Elena

2011-06-01

Tissue engineering is reviving itself, adopting the concept of biomimetics of in vivo tissue development. A basic concept of developmental biology is the modularity of the tissue architecture according to which intermediates in tissue development constitute semiautonomous entities. Both engineering and nature have chosen the modular architecture to optimize the product or organism development and evolution. Bioartificial tissues do not have a modular architecture. On the contrary, artificial organs of modular architecture have been already developed in the field of artificial organs. Therefore the conceptual support of tissue engineering by the field of artificial organs becomes critical in its new endeavor of recapitulating in vitro the in vivo tissue development. © 2011, Copyright the Authors. Artificial Organs © 2011, International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

Recent advancements in electrospinning design for tissue engineering applications: A review.

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Kishan, Alysha P; Cosgriff-Hernandez, Elizabeth M

2017-10-01

Electrospinning, a technique used to fabricate fibrous scaffolds, has gained popularity in recent years as a method to produce tissue engineered grafts with architectural similarities to the extracellular matrix. Beyond its versatility in material selection, electrospinning also provides many tools to tune the fiber morphology and scaffold geometry. Recent efforts have focused on extending the capabilities of electrospinning to produce scaffolds that better recapitulate tissue properties and enhance regeneration. This review highlights these advancements by providing an overview of the processing variables and setups used to modulate scaffold architecture, discussing strategies to improve cellular infiltration and guide cell behavior, and providing a summary of electrospinning applications in tissue engineering. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 2892-2905, 2017. © 2017 Wiley Periodicals, Inc.

Toward the Validation of Maternal Embryonic Leucine Zipper Kinase: Discovery, Optimization of Highly Potent and Selective Inhibitors, and Preliminary Biology Insight

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Touré, B. Barry; Giraldes, John; Smith, Troy; Sprague, Elizabeth R.; Wang, Yaping; Mathieu, Simon; Chen, Zhuoliang; Mishina, Yuji; Feng, Yun; Yan-Neale, Yan; Shakya, Subarna; Chen, Dongshu; Meyer, Matthew; Puleo, David; Brazell, J. Tres; Straub, Christopher; Sage, David; Wright, Kirk; Yuan, Yanqiu; Chen, Xin; Duca, Jose; Kim, Sean; Tian, Li; Martin, Eric; Hurov, Kristen; Shao, Wenlin (Novartis)

2016-05-26

MELK kinase has been implicated in playing an important role in tumorigenesis. Our previous studies suggested that MELK is involved in the regulation of cell cycle and its genetic depletion leads to growth inhibition in a subset of high MELK-expressing basal-like breast cancer cell lines. Herein we describe the discovery and optimization of novel MELK inhibitors 8a and 8b that recapitulate the cellular effects observed by short hairpin ribonucleic acid (shRNA)-mediated MELK knockdown in cellular models. We also discovered a novel fluorine-induced hydrophobic collapse that locked the ligand in its bioactive conformation and led to a 20-fold gain in potency. These novel pharmacological inhibitors achieved high exposure in vivo and were well tolerated, which may allow further in vivo evaluation.

Transcriptomic profiling of primary alveolar epithelial cell differentiation in human and rat

Directory of Open Access Journals (Sweden)

Crystal N. Marconett

2014-12-01

Full Text Available Cell-type specific gene regulation is a key to gaining a full understanding of how the distinct phenotypes of differentiated cells are achieved and maintained. Here we examined how changes in transcriptional activation during alveolar epithelial cell (AEC differentiation determine phenotype. We performed transcriptomic profiling using in vitro differentiation of human and rat primary AEC. This model recapitulates in vitro an in vivo process in which AEC transition from alveolar type 2 (AT2 cells to alveolar type 1 (AT1 cells during normal maintenance and regeneration following lung injury. Here we describe in detail the quality control, preprocessing, and normalization of microarray data presented within the associated study (Marconett et al., 2013. We also include R code for reproducibility of the referenced data and easily accessible processed data tables.

Self-organization of spatial patterning in human embryonic stem cells

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Deglincerti, Alessia; Etoc, Fred; Ozair, M. Zeeshan; Brivanlou, Ali H.

2017-01-01

The developing embryo is a remarkable example of self-organization, where functional units are created in a complex spatio-temporal choreography. Recently, human embryonic stem cells (ESCs) have been used to recapitulate in vitro the self-organization programs that are executed in the embryo in vivo. This represents a unique opportunity to address self-organization in humans that is otherwise not addressable with current technologies. In this essay, we review the recent literature on self-organization of human ESCs, with a particular focus on two examples: formation of embryonic germ layers and neural rosettes. Intriguingly, both activation and elimination of TGFβ signaling can initiate self-organization, albeit with different molecular underpinnings. We discuss the mechanisms underlying the formation of these structures in vitro and explore future challenges in the field. PMID:26970615

Loss of Akt1 in mice increases energy expenditure and protects against diet-induced obesity.

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Wan, Min; Easton, Rachael M; Gleason, Catherine E; Monks, Bobby R; Ueki, Kohjiro; Kahn, C Ronald; Birnbaum, Morris J

2012-01-01

Akt is encoded by a gene family for which each isoform serves distinct but overlapping functions. Based on the phenotypes of the germ line gene disruptions, Akt1 has been associated with control of growth, whereas Akt2 has been linked to metabolic regulation. Here we show that Akt1 serves an unexpected role in the regulation of energy metabolism, as mice deficient for Akt1 exhibit protection from diet-induced obesity and its associated insulin resistance. Although skeletal muscle contributes most of the resting and exercising energy expenditure, muscle-specific deletion of Akt1 does not recapitulate the phenotype, indicating that the role of Akt1 in skeletal muscle is cell nonautonomous. These data indicate a previously unknown function of Akt1 in energy metabolism and provide a novel target for treatment of obesity.

DEPDC5 takes a second hit in familial focal epilepsy.

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Anderson, Matthew P

2018-04-30

Loss-of-function mutations in a single allele of the gene encoding DEP domain-containing 5 protein (DEPDC5) are commonly linked to familial focal epilepsy with variable foci; however, a subset of patients presents with focal cortical dysplasia that is proposed to result from a second-hit somatic mutation. In this issue of the JCI, Ribierre and colleagues provide several lines of evidence to support second-hit DEPDC5 mutations in this disorder. Moreover, the authors use in vivo, in utero electroporation combined with CRISPR-Cas9 technology to generate a murine model of the disease that recapitulates human manifestations, including cortical dysplasia-like changes, focal seizures, and sudden unexpected death. This study provides important insights into familial focal epilepsy and provides a preclinical model for evaluating potential therapies.

Androgen receptor mutations associated with androgen insensitivity syndrome: a high content analysis approach leading to personalized medicine.

Directory of Open Access Journals (Sweden)

Adam T Szafran

2009-12-01

Full Text Available Androgen insensitivity syndrome (AIS is a rare disease associated with inactivating mutations of AR that disrupt male sexual differentiation, and cause a spectrum of phenotypic abnormalities having as a common denominator loss of reproductive viability. No established treatment exists for these conditions, however there are sporadic reports of patients (or recapitulated mutations in cell lines that respond to administration of supraphysiologic doses (or pulses of testosterone or synthetic ligands. Here, we utilize a novel high content analysis (HCA approach to study AR function at the single cell level in genital skin fibroblasts (GSF. We discuss in detail findings in GSF from three historical patients with AIS, which include identification of novel mechanisms of AR malfunction, and the potential ability to utilize HCA for personalized treatment of patients affected by this condition.

Synthesis and Evaluation of a 2,11-Cembranoid-Inspired Library.

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Welford, Amanda J; Caldwell, John J; Liu, Manjuan; Richards, Meirion; Brown, Nathan; Lomas, Cara; Tizzard, Graham J; Pitak, Mateusz B; Coles, Simon J; Eccles, Suzanne A; Raynaud, Florence I; Collins, Ian

2016-04-11

The 2,11-cembranoid family of natural products has been used as inspiration for the synthesis of a structurally simplified, functionally diverse library of octahydroisobenzofuran-based compounds designed to augment a typical medicinal chemistry library screen. Ring-closing metathesis, lactonisation and SmI2 -mediated methods were exemplified and applied to the installation of a third ring to mimic the nine-membered ring of the 2,11-cembranoids. The library was assessed for aqueous solubility and permeability, with a chemical-space analysis performed for comparison to the family of cembranoid natural products and a sample set of a screening library. Preliminary investigations in cancer cells showed that the simpler scaffolds could recapitulate the reported anti-migratory activity of the natural products. © 2016 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.

An essential role of intestinal cell kinase in lung development is linked to the perinatal lethality of human ECO syndrome

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Tong, Yixin; Park, So Hyun; Wu, Di; Xu, Wenhao; Guillot, Stacey J.; Jin, Li; Li, Xudong; Wang, Yalin; Lin, Chyuan-Sheng; Fu, Zheng

2017-01-01

Human endocrine-cerebro-osteodysplasia (ECO) syndrome, caused by the loss-of-function mutation R272Q in the ICK (intestinal cell kinase) gene, is a neonatal-lethal developmental disorder. To elucidate the molecular basis of ECO syndrome, we constructed an Ick R272Q knock-in mouse model that recapitulates ECO pathological phenotypes. Newborns bearing Ick R272Q homozygous mutations die at birth due to respiratory distress. Ick mutant lungs exhibit not only impaired branching morphogenesis associated with reduced mesenchymal proliferation, but also significant airspace deficiency in primitive alveoli concomitant with abnormal interstitial mesenchymal differentiation. ICK dysfunction induces elongated primary cilia and perturbs ciliary Hedgehog signaling and autophagy during lung sacculation. Our study identifies an essential role for ICK in lung development and advances the mechanistic understanding of ECO syndrome. PMID:28380258

Stress Effects on Multiple Memory System Interactions

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Ness, Deborah; Calabrese, Pasquale

2016-01-01

Extensive behavioural, pharmacological, and neurological research reports stress effects on mammalian memory processes. While stress effects on memory quantity have been known for decades, the influence of stress on multiple memory systems and their distinct contributions to the learning process have only recently been described. In this paper, after summarizing the fundamental biological aspects of stress/emotional arousal and recapitulating functionally and anatomically distinct memory systems, we review recent animal and human studies exploring the effects of stress on multiple memory systems. Apart from discussing the interaction between distinct memory systems in stressful situations, we will also outline the fundamental role of the amygdala in mediating such stress effects. Additionally, based on the methods applied in the herein discussed studies, we will discuss how memory translates into behaviour. PMID:27034845

Trehalose-6-Phosphate: connecting plant metabolism and development

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Jathish ePonnu

2011-11-01

Full Text Available Beyond their metabolic roles, sugars can also act as messengers in signal transduction. Trehalose, a sugar found in many species of plants and animals, is a non-reducing disaccharide composed of two glucose moieties. Its synthesis in plants is a two-step process, involving the production of trehalose-6-phosphate (T6P catalyzed by TREHALOSE-6-PHOSPHATE SYNTHASE (TPS and its consecutive dephosphorylation to trehalose, catalyzed by TREHALOSE-6-PHOSPHATE PHOSPHATASE (TPP. T6P has recently emerged as an important signaling metabolite, regulating carbon assimilation and sugar status in plants. In addition, T6P has also been demonstrated to play an essential role in plant development. This review recapitulates the recent advances in our understanding the role of T6P in coordinating diverse metabolic and developmental processes.

Imaging dynamics of CD11c+ cells and Foxp3+ cells in progressive autoimmune insulitis in the NOD mouse model of type 1 diabetes

DEFF Research Database (Denmark)

Schmidt-Christensen, Anja; Hansen, Lisbeth; Ilegems, Erwin

2013-01-01

the endocrine pancreas during initiation and progression of insulitis in the NOD mouse. Individual, ACE-transplanted islets of Langerhans were longitudinally and repetitively imaged by stereomicroscopy and two-photon microscopy to follow fluorescently labelled leucocyte subsets. Results We demonstrate that......, in spite of the immune privileged status of the eye, the ACE-transplanted islets develop infiltration and beta cell destruction, recapitulating the autoimmune insulitis of the pancreas, and exemplify this by analysing reporter cell populations expressing green fluorescent protein under the Cd11c or Foxp3......Aims/hypothesis The aim of this study was to visualise the dynamics and interactions of the cells involved in autoimmune-driven inflammation in type 1 diabetes. Methods We adopted the anterior chamber of the eye (ACE) transplantation model to perform non-invasive imaging of leucocytes infiltrating...