Subependymal Heterotopia Mimicking Mass in Conventional Magnetic Resonance Imaging: Demonstration With 3T Advanced Neuroimages.

PubMed

Aktas, Filiz; Ogul, Hayri

2017-10-01

The authors reported a rare patient with large subependymal heterotopia mimicking cerebral neoplasia. A 22-year-old female was admitted with a history of right-sided paresthesia accompanied by progressive headache. Cerebral magnetic resonance (MR) imaging showed a large solid lesion in the left frontal lobe. Advanced MR images proved that the lesion was compatible with subependymal heterotopia. Large subependymal heterotopia may mimick cerebral neoplasia.

Memory and learning behaviors mimicked in nanogranular SiO2-based proton conductor gated oxide-based synaptic transistors

NASA Astrophysics Data System (ADS)

Wan, Chang Jin; Zhu, Li Qiang; Zhou, Ju Mei; Shi, Yi; Wan, Qing

2013-10-01

In neuroscience, signal processing, memory and learning function are established in the brain by modifying ionic fluxes in neurons and synapses. Emulation of memory and learning behaviors of biological systems by nanoscale ionic/electronic devices is highly desirable for building neuromorphic systems or even artificial neural networks. Here, novel artificial synapses based on junctionless oxide-based protonic/electronic hybrid transistors gated by nanogranular phosphorus-doped SiO2-based proton-conducting films are fabricated on glass substrates by a room-temperature process. Short-term memory (STM) and long-term memory (LTM) are mimicked by tuning the pulse gate voltage amplitude. The LTM process in such an artificial synapse is due to the proton-related interfacial electrochemical reaction. Our results are highly desirable for building future neuromorphic systems or even artificial networks via electronic elements.In neuroscience, signal processing, memory and learning function are established in the brain by modifying ionic fluxes in neurons and synapses. Emulation of memory and learning behaviors of biological systems by nanoscale ionic/electronic devices is highly desirable for building neuromorphic systems or even artificial neural networks. Here, novel artificial synapses based on junctionless oxide-based protonic/electronic hybrid transistors gated by nanogranular phosphorus-doped SiO2-based proton-conducting films are fabricated on glass substrates by a room-temperature process. Short-term memory (STM) and long-term memory (LTM) are mimicked by tuning the pulse gate voltage amplitude. The LTM process in such an artificial synapse is due to the proton-related interfacial electrochemical reaction. Our results are highly desirable for building future neuromorphic systems or even artificial networks via electronic elements. Electronic supplementary information (ESI) available. See DOI: 10.1039/c3nr02987e

Bacterial fermentation platform for producing artificial aromatic amines

PubMed Central

Masuo, Shunsuke; Zhou, Shengmin; Kaneko, Tatsuo; Takaya, Naoki

2016-01-01

Aromatic amines containing an aminobenzene or an aniline moiety comprise versatile natural and artificial compounds including bioactive molecules and resources for advanced materials. However, a bio-production platform has not been implemented. Here we constructed a bacterial platform for para-substituted aminobenzene relatives of aromatic amines via enzymes in an alternate shikimate pathway predicted in a Pseudomonad bacterium. Optimization of the metabolic pathway in Escherichia coli cells converted biomass glucose to 4-aminophenylalanine with high efficiency (4.4 g L−1 in fed-batch cultivation). We designed and produced artificial pathways that mimicked the fungal Ehrlich pathway in E. coli and converted 4-aminophenylalanine into 4-aminophenylethanol and 4-aminophenylacetate at 90% molar yields. Combining these conversion systems or fungal phenylalanine decarboxylases, the 4-aminophenylalanine-producing platform fermented glucose to 4-aminophenylethanol, 4-aminophenylacetate, and 4-phenylethylamine. This original bacterial platform for producing artificial aromatic amines highlights their potential as heteroatoms containing bio-based materials that can replace those derived from petroleum. PMID:27167511

Artificial synapse network on inorganic proton conductor for neuromorphic systems.

PubMed

Zhu, Li Qiang; Wan, Chang Jin; Guo, Li Qiang; Shi, Yi; Wan, Qing

2014-01-01

The basic units in our brain are neurons, and each neuron has more than 1,000 synapse connections. Synapse is the basic structure for information transfer in an ever-changing manner, and short-term plasticity allows synapses to perform critical computational functions in neural circuits. Therefore, the major challenge for the hardware implementation of neuromorphic computation is to develop artificial synapse network. Here in-plane lateral-coupled oxide-based artificial synapse network coupled by proton neurotransmitters are self-assembled on glass substrates at room-temperature. A strong lateral modulation is observed due to the proton-related electrical-double-layer effect. Short-term plasticity behaviours, including paired-pulse facilitation, dynamic filtering and spatiotemporally correlated signal processing are mimicked. Such laterally coupled oxide-based protonic/electronic hybrid artificial synapse network proposed here is interesting for building future neuromorphic systems.

Expression of Na+/glucose co-transporter 1 (SGLT1) is enhanced by supplementation of the diet of weaning piglets with artificial sweeteners.

PubMed

Moran, Andrew W; Al-Rammahi, Miran A; Arora, Daleep K; Batchelor, Daniel J; Coulter, Erin A; Daly, Kristian; Ionescu, Catherine; Bravo, David; Shirazi-Beechey, Soraya P

2010-09-01

In an intensive livestock production, a shorter suckling period allows more piglets to be born. However, this practice leads to a number of disorders including nutrient malabsorption, resulting in diarrhoea, malnutrition and dehydration. A number of strategies have been proposed to overcome weaning problems. Artificial sweeteners, routinely included in piglets' diet, were thought to enhance feed palatability. However, it is shown in rodent models that when included in the diet, they enhance the expression of Na+/glucose co-transporter (SGLT1) and the capacity of the gut to absorb glucose. Here, we show that supplementation of piglets' feed with a combination of artificial sweeteners saccharin and neohesperidin dihydrochalcone enhances the expression of SGLT1 and intestinal glucose transport function. Artificial sweeteners are known to act on the intestinal sweet taste receptor T1R2/T1R3 and its partner G-protein, gustducin, to activate pathways leading to SGLT1 up-regulation. Here, we demonstrate that T1R2, T1R3 and gustducin are expressed together in the enteroendocrine cells of piglet intestine. Furthermore, gut hormones secreted by the endocrine cells in response to dietary carbohydrates, glucagon-like peptides (GLP)-1, GLP-2 and glucose-dependent insulinotrophic peptide (GIP), are co-expressed with type 1 G-protein-coupled receptors (T1R) and gustducin, indicating that L- and K-enteroendocrine cells express these taste elements. In a fewer endocrine cells, T1R are also co-expressed with serotonin. Lactisole, an inhibitor of human T1R3, had no inhibitory effect on sweetener-induced SGLT1 up-regulation in piglet intestine. A better understanding of the mechanism(s) involved in sweetener up-regulation of SGLT1 will allow the identification of nutritional targets with implications for the prevention of weaning-related malabsorption.

Magnetic skyrmion-based artificial neuron device

NASA Astrophysics Data System (ADS)

Li, Sai; Kang, Wang; Huang, Yangqi; Zhang, Xichao; Zhou, Yan; Zhao, Weisheng

2017-08-01

Neuromorphic computing, inspired by the biological nervous system, has attracted considerable attention. Intensive research has been conducted in this field for developing artificial synapses and neurons, attempting to mimic the behaviors of biological synapses and neurons, which are two basic elements of a human brain. Recently, magnetic skyrmions have been investigated as promising candidates in neuromorphic computing design owing to their topologically protected particle-like behaviors, nanoscale size and low driving current density. In one of our previous studies, a skyrmion-based artificial synapse was proposed, with which both short-term plasticity and long-term potentiation functions have been demonstrated. In this work, we further report on a skyrmion-based artificial neuron by exploiting the tunable current-driven skyrmion motion dynamics, mimicking the leaky-integrate-fire function of a biological neuron. With a simple single-device implementation, this proposed artificial neuron may enable us to build a dense and energy-efficient spiking neuromorphic computing system.

Anticonvulsant activity of artificial sweeteners: a structural link between sweet-taste receptor T1R3 and brain glutamate receptors.

PubMed

Talevi, Alan; Enrique, Andrea V; Bruno-Blanch, Luis E

2012-06-15

A virtual screening campaign based on application of a topological discriminant function capable of identifying novel anticonvulsant agents indicated several widely-used artificial sweeteners as potential anticonvulsant candidates. Acesulfame potassium, cyclamate and saccharin were tested in the Maximal Electroshock Seizure model (mice, ip), showing moderate anticonvulsant activity. We hypothesized a probable structural link between the receptor responsible of sweet taste and anticonvulsant molecular targets. Bioinformatic tools confirmed a highly significant sequence-similarity between taste-related protein T1R3 and several metabotropic glutamate receptors from different species, including glutamate receptors upregulated in epileptogenesis and certain types of epilepsy. Copyright © 2012 Elsevier Ltd. All rights reserved.

A light-driven artificial flytrap

PubMed Central

Wani, Owies M.; Zeng, Hao; Priimagi, Arri

2017-01-01

The sophistication, complexity and intelligence of biological systems is a continuous source of inspiration for mankind. Mimicking the natural intelligence to devise tiny systems that are capable of self-regulated, autonomous action to, for example, distinguish different targets, remains among the grand challenges in biomimetic micro-robotics. Herein, we demonstrate an autonomous soft device, a light-driven flytrap, that uses optical feedback to trigger photomechanical actuation. The design is based on light-responsive liquid-crystal elastomer, fabricated onto the tip of an optical fibre, which acts as a power source and serves as a contactless probe that senses the environment. Mimicking natural flytraps, this artificial flytrap is capable of autonomous closure and object recognition. It enables self-regulated actuation within the fibre-sized architecture, thus opening up avenues towards soft, autonomous small-scale devices. PMID:28534872

Discovery of an artificial peptide agonist to the fibroblast growth factor receptor 1c/βKlotho complex from random peptide T7 phage display.

PubMed

Sakamoto, Kotaro; Kawata, Yayoi; Masuda, Yasushi; Umemoto, Tadashi; Ito, Takashi; Asami, Taiji; Takekawa, Shiro; Ohtaki, Tetsuya; Inooka, Hiroshi

2016-11-04

Fibroblast growth factor receptor-1c (FGFR1c)/βKlotho (KLB) complex is a receptor of fibroblast growth factor 21 (FGF21). Pharmacologically, FGF21 shows anti-obesity and anti-diabetic effects upon peripheral administration. Here, we report the development of an artificial peptide agonist to the FGFR1c/KLB heterodimer complex. The peptide, F91-8A07 (LPGRTCREYPDLWWVRCY), was discovered from random peptide T7 phage display and selectively bound to the FGFR1c/KLB complex, but not to FGFR1c and KLB individually. After subsequent peptide dimerization using a short polyethyleneglycol (PEG) linker, the dimeric F91-8A07 peptide showed higher potent agonist activity than that of FGF21 in cultured primary human adipocytes. Moreover, the dimeric peptide led to an expression of the early growth response protein-1 (Egr-1) mRNA in vivo, which is a target gene of FGFR1c. To the best of our knowledge, this is the first report of a FGFR1c/KLB complex-selective artificial peptide agonist. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Anti-diabetic activity of fused PPARγ-SIRT1 ligands with limited body-weight gain by mimicking calorie restriction and decreasing SGK1 expression.

PubMed

Pirat, Celine; Dacquet, Catherine; Leclerc, Veronique; Hennuyer, Nathalie; Beucher-Gaudin, Monique; Zanirato, Ghislaine; Géant, Anne; Staels, Bart; Ktorza, Alain; Farce, Amaury; Caignard, Daniel-Henri; Berthelot, Pascal; Lebegue, Nicolas

2017-09-08

A series of benzothiazol-2-one containing α-ethoxyphenylpropionic acid derivatives incorporating resveratrol or butein scaffolds were designed as fused full PPARγ agonist ligands and SIRT1-activating compounds for the treatment of type 2 diabetes (T2D) and its complications. Compound 14d displayed the best in vitro pharmacological profile with full PPARγ agonist activity (Emax = 98%, EC 50  = 200 nM), SIRT1 enzymatic activation (+128%) and SGK1 expression inhibition (- 57%) which is known to limit side effects as fluid retention and body-weight gain. Compound 14d showed high efficacy in an ob/ob mice model with significant decreases in serum triglyceride, glucose and insulin levels but mostly with limited body-weight gain by mimicking calorie restriction (CR) and inhibiting SGK1 expression. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Artificial hairy surfaces with a nearly perfect hydrophobic response.

PubMed

Hsu, Shu-Hau; Sigmund, Wolfgang M

2010-02-02

A nearly perfect hydrophobic interface by dint of mimicking hairs of arthropods was achieved for the first time. These Gamma-shape artificial hairs were made via a membrane casting technique on polypropylene substrates. This extreme hydrophobicity merely arises from microstructure modification, and no further chemical treatments are needed. The ultralow adhesion to water droplets was evaluated through video assessment, and it is believed to be attributed to the mechanical response of the artificial hairs. The principle of this fabrication technique is accessible and is expected to be compatible with large-area fabrication of superhydrophobic interfaces.

Heart rate informed artificial pancreas system enhances glycemic control during exercise in adolescents with T1D.

PubMed

DeBoer, Mark D; Cherñavvsky, Daniel R; Topchyan, Katarina; Kovatchev, Boris P; Francis, Gary L; Breton, Marc D

2017-11-01

To evaluate the safety and performance of using a heart rate (HR) monitor to inform an artificial pancreas (AP) system during exercise among adolescents with type 1 diabetes (T1D). In a randomized, cross-over trial, adolescents with T1D age 13 - 18 years were enrolled to receive on separate days either the unmodified UVa AP (stdAP) or an AP system connected to a portable HR monitor (AP-HR) that triggered an exercise algorithm for blood glucose (BG) control. During admissions participants underwent a structured exercise regimen. Hypoglycemic events and CGM tracings were compared between the two admissions, during exercise and for the full 24-hour period. Eighteen participants completed the trial. While number of hypoglycemic events during exercise and rest was not different between visits (0.39 AP-HR vs 0.50 stdAP), time below 70 mg dL -1 was lower on AP-HR compared to stdAP, 0.5±2.1% vs 7.4±12.5% (P = 0.028). Time with BG within 70-180 mg dL -1 was higher for the AP-HR admission vs stdAP during the exercise portion and overall (96% vs 87%, and 77% vs 74%), but these did not reach statistical significance (P = 0.075 and P = 0.366). Heart rate signals can safely and efficaciously be integrated in a wireless AP system to inform of physical activity. While exercise contributes to hypoglycemia among adolescents, even when using an AP system, informing the system of exercise via a HR monitor improved time <70 mg dL -1 . Nonetheless, it did not significantly reduce the total number of hypoglycemic events, which were low in both groups. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Artificial Neural Networks Equivalent to Fuzzy Algebra T-Norm Conjunction Operators

NASA Astrophysics Data System (ADS)

Iliadis, L. S.; Spartalis, S. I.

2007-12-01

This paper describes the construction of three Artificial Neural Networks with fuzzy input and output, imitating the performance of fuzzy algebra conjunction operators. More specifically, it is applied over the results of a previous research effort that used T-Norms in order to produce a characteristic torrential risk index that unified the partial risk indices for the area of Xanthi. Each one of the three networks substitutes a T-Norm and consequently they can be used as equivalent operators. This means that ANN performing Fuzzy Algebra operations can be designed and developed.

Artificial local magnetic field inhomogeneity enhances T2 relaxivity

PubMed Central

Zhou, Zijian; Tian, Rui; Wang, Zhenyu; Yang, Zhen; Liu, Yijing; Liu, Gang; Wang, Ruifang; Song, Jibin; Nie, Liming; Chen, Xiaoyuan

2017-01-01

Clustering of magnetic nanoparticles (MNPs) is perhaps the most effective, yet intriguing strategy to enhance T2 relaxivity in magnetic resonance imaging (MRI). However, the underlying mechanism is still not fully understood and the attempts to generalize the classic outersphere theory from single particles to clusters have been found to be inadequate. Here we show that clustering of MNPs enhances local field inhomogeneity due to reduced field symmetry, which can be further elevated by artificially involving iron oxide NPs with heterogeneous geometries in terms of size and shape. The r2 values of iron oxide clusters and Landau–Lifshitz–Gilbert simulations confirmed our hypothesis, indicating that solving magnetic field inhomogeneity may become a powerful way to build correlation between magnetization and T2 relaxivity of MNPs, especially magnetic clusters. This study provides a simple yet distinct mechanism to interpret T2 relaxivity of MNPs, which is crucial to the design of high-performance MRI contrast agents. PMID:28516947

Programmable Control in Extracellular Matrix-mimicking Polymer Hydrogels.

PubMed

Hof, Kevin S; Bastings, Maartje M C

2017-06-28

The extracellular matrix (ECM) and cells have a reciprocal relationship, one shapes the other and vice versa. One of the main challenges of synthetic material systems for developmental cell culturing, organoid and stem cell work includes the implementation of this reciprocal nature. The largest hurdle to achieve true cell-instructive materials in biomaterials engineering is a lack of spatial and temporal control over material properties and the display of bioactive signals compared to the natural cell environment. ECM-mimicking hydrogels have been developed using a wide range of polymers, assembly and cross-linking strategies. While our synthetic toolbox is larger than nature, often our systems underperform when compared to ECM systems with natural components like Matrigel. Material properties and three-dimensional structure ill-represent the three-dimensional ECM reciprocal nature and ligand presentation is an oversimplified version of the complexity found in nature. We hypothesize that the lack of programmable control in properties and ligand presentation forms the basis of this mismatch in performance and analyze the presence of control in current state of the art ECM-mimicking systems based on covalent, supramolecular and recombinant polymers. We conclude that through combining the dynamics of supramolecular materials, robustness from covalent systems and the programmable spatial control of bio-activation in recombinant ECM materials, the optimal synthetic artificial ECM could be assembled.

Protein-scaffold Directed Nanoscale Assembly of T Cell Ligands: Artificial Antigen Presentation with Defined Valency, Density and Ratio.

PubMed

Smith, Mason R; Tolbert, Stephanie V; Wen, Fei

2018-05-07

Tuning antigen presentation to T cells is a critical step in investigating key aspects of T cell activation. However, existing technologies have limited ability to control the spatial and stoichiometric organization of T cell ligands on 3D surfaces. Here, we developed an artificial antigen presentation platform based on protein-scaffold directed assembly that allows fine control over the spatial and stoichiometric organization of T cell ligands on a 3D yeast-cell surface. Using this system, we observed that the T cell activation threshold on a 3D surface is independent of peptide-major histocompatibility complex (pMHC) valency, but instead determined by the overall pMHC surface density. When intercellular adhesion molecule 1 (ICAM-1) was co-assembled with pMHC, it enhanced antigen recognition sensitivity by 6-fold. Further, T cells responded with different magnitudes to varying ratios of pMHC and ICAM-1 and exhibited a maximum response at a ratio of 15% pMHC and 85% ICAM-1, introducing an additional parameter for tuning T cell activation. This protein-scaffold directed assembly technology is readily transferrable to acellular surfaces for translational research as well as large-scale T-cell manufacturing.

The Basics of Artificial Antigen Presenting Cells in T Cell-Based Cancer Immunotherapies.

PubMed

Neal, Lillian R; Bailey, Stefanie R; Wyatt, Megan M; Bowers, Jacob S; Majchrzak, Kinga; Nelson, Michelle H; Haupt, Carl; Paulos, Chrystal M; Varela, Juan C

2017-01-01

Adoptive T cell transfer (ACT) can mediate objective responses in patients with advanced malignancies. There have been major advances in this field, including the optimization of the ex vivo generation of tumor-reactive lymphocytes to ample numbers for effective ACT therapy via the use of natural and artificial antigen presenting cells (APCs). Herein we review the basic properties of APCs and how they have been manufactured through the years to augment vaccine and T cell-based cancer therapies. We then discuss how these novel APCs impact the function and memory properties of T cells. Finally, we propose new ways to synthesize aAPCs to augment the therapeutic effectiveness of antitumor T cells for ACT therapy.

The Basics of Artificial Antigen Presenting Cells in T Cell-Based Cancer Immunotherapies

PubMed Central

Neal, Lillian R.; Bailey, Stefanie R.; Wyatt, Megan M.; Bowers, Jacob S.; Majchrzak, Kinga; Nelson, Michelle H.; Haupt, Carl; Paulos, Chrystal M.; Varela, Juan C.

2017-01-01

Adoptive T cell transfer (ACT) can mediate objective responses in patients with advanced malignancies. There have been major advances in this field, including the optimization of the ex vivo generation of tumor-reactive lymphocytes to ample numbers for effective ACT therapy via the use of natural and artificial antigen presenting cells (APCs). Herein we review the basic properties of APCs and how they have been manufactured through the years to augment vaccine and T cell-based cancer therapies. We then discuss how these novel APCs impact the function and memory properties of T cells. Finally, we propose new ways to synthesize aAPCs to augment the therapeutic effectiveness of antitumor T cells for ACT therapy. PMID:28825053

InxAl1-xN chiral nanorods mimicking the polarization features of scarab beetles

NASA Astrophysics Data System (ADS)

Magnusson, R.; Birch, J.; Hsiao, C.-L.; Sandström, P.; Arwin, H.; Järrendahl, K.

2015-03-01

The scarab beetle Cetonia aurata is known to reflect light with brilliant colors and a high degree of circular polarization. Both color and polarization effects originate from the beetles exoskeleton and have been attributed to a Bragg reflection of the incident light due to a twisted laminar structure. Our strategy for mimicking the optical properties of the Cetonia aurata was therefore to design and fabricate transparent, chiral films. A series of films with tailored transparent structures of helicoidal InxAl1-xN nanorods were grown on sapphire substrates using UHV magnetron sputtering. The value of x is tailored to gradually decrease from one side to the other in each nanorod normal to its growth direction. This introduces an in-plane anisotropy with different refractive indices in the direction of the gradient and perpendicular to it. By rotating the sample during film growth the in-plane optical axis will be rotated from bottom to top and thereby creating a chiral film. Based on Muellermatrix ellipsometry, optical modeling has been done suggesting that both the exoskeleton of Cetonia aurata and our artificial material can be modeled by an anisotropic film made up of a stack of thin layers, each one with its in-plane optical axis slightly rotated with respect to the previous layer. Simulations based on the optical modeling were used to investigate how pitch and thickness of the film together with the optical properties of the constitutive materials affects the width and spectral position of the Bragg reflection band.

DNA-Mediated Self-Organization of Polymeric Nanocompartments Leads to Interconnected Artificial Organelles.

PubMed

Liu, Juan; Postupalenko, Viktoriia; Lörcher, Samuel; Wu, Dalin; Chami, Mohamed; Meier, Wolfgang; Palivan, Cornelia G

2016-11-09

Self-organization of nanocomponents was mainly focused on solid nanoparticles, quantum dots, or liposomes to generate complex architectures with specific properties, but intrinsically limited or not developed enough, to mimic sophisticated structures with biological functions in cells. Here, we present a biomimetic strategy to self-organize synthetic nanocompartments (polymersomes) into clusters with controlled properties and topology by exploiting DNA hybridization to interconnect polymersomes. Molecular and external factors affecting the self-organization served to design clusters mimicking the connection of natural organelles: fine-tune of the distance between tethered polymersomes, different topologies, no fusion of clustered polymersomes, and no aggregation. Unexpected, extended DNA bridges that result from migration of the DNA strands inside the thick polymer membrane (about 12 nm) represent a key stability and control factor, not yet exploited for other synthetic nano-object networks. The replacement of the empty polymersomes with artificial organelles, already reported for single polymersome architecture, will provide an excellent platform for the development of artificial systems mimicking natural organelles or cells and represents a fundamental step in the engineering of molecular factories.

T-Cell Artificial Focal Triggering Tools: Linking Surface Interactions with Cell Response

PubMed Central

Carpentier, Benoît; Pierobon, Paolo; Hivroz, Claire; Henry, Nelly

2009-01-01

T-cell activation is a key event in the immune system, involving the interaction of several receptor ligand pairs in a complex intercellular contact that forms between T-cell and antigen-presenting cells. Molecular components implicated in contact formation have been identified, but the mechanism of activation and the link between molecular interactions and cell response remain poorly understood due to the complexity and dynamics exhibited by whole cell-cell conjugates. Here we demonstrate that simplified model colloids grafted so as to target appropriate cell receptors can be efficiently used to explore the relationship of receptor engagement to the T-cell response. Using immortalized Jurkat T cells, we monitored both binding and activation events, as seen by changes in the intracellular calcium concentration. Our experimental strategy used flow cytometry analysis to follow the short time scale cell response in populations of thousands of cells. We targeted both T-cell receptor CD3 (TCR/CD3) and leukocyte-function-associated antigen (LFA-1) alone or in combination. We showed that specific engagement of TCR/CD3 with a single particle induced a transient calcium signal, confirming previous results and validating our approach. By decreasing anti-CD3 particle density, we showed that contact nucleation was the most crucial and determining step in the cell-particle interaction under dynamic conditions, due to shear stress produced by hydrodynamic flow. Introduction of LFA-1 adhesion molecule ligands at the surface of the particle overcame this limitation and elucidated the low TCR/CD3 ligand density regime. Despite their simplicity, model colloids induced relevant biological responses which consistently echoed whole cell behavior. We thus concluded that this biophysical approach provides useful tools for investigating initial events in T-cell activation, and should enable the design of intelligent artificial systems for adoptive immunotherapy. PMID:19274104

SirT1 mediates hyperbaric oxygen preconditioning-induced ischemic tolerance in rat brain

PubMed Central

Yan, Wenjun; Fang, Zongping; Yang, Qianzi; Dong, Hailong; Lu, Yan; Lei, Chong; Xiong, Lize

2013-01-01

Our previous studies have shown that hyperbaric oxygen preconditioning (HBO-PC) induces tolerance to cerebral ischemia/reperfusion (I/R). This study aimed to investigate whether SirT1, a class III histone deacetylase, is involved in neuroprotection elicited by HBO-PC in animal and cell culture models of ischemia. Rats were subjected to middle cerebral artery occlusion for 120 minutes after HBO-PC (once a day for 5 days). Primary cultured cortical neurons were exposed to 2 hours of HBO-PC after 2 hours of oxygen–glucose deprivation (OGD). We showed that HBO-PC increased SirT1 protein and mRNA expression, promoted neurobehavioral score, reduced infarct volume, and improved morphology at 24 hours and 7 days after cerebral I/R. Neuroprotection of HBO-PC was attenuated by SirT1 inhibitor EX527 and SirT1 knockdown by short interfering RNA (siRNA), whereas it was mimicked by SirT1 activator resveratrol. Furthermore, HBO-PC enhanced SirT1 expression and cell viability and reduced lactate dehydrogenase release 24 hours after OGD/re-oxygenation. The neuroprotective effect of HBO-PC was emulated through upregulating SirT1 and, reversely, attenuated through downregulating SirT1. The modulation of SirT1 was made by adenovirus infection carrying SirT1 or SirT1 siRNA. Besides, SirT1 increased B-cell lymphoma 2 (Bcl-2) expression and decrease cleaved caspase 3. These results indicate that SirT1 mediates HBO-PC-induced tolerance to cerebral I/R through inhibition of apoptosis. PMID:23299244

Systemic lupus erythematosus (SLE) pneumonitis mimicking swine influenza pneumonia during the swine influenza (H1N1) pandemic.

PubMed

Cunha, Burke A; Syed, Uzma; Mickail, Nardeen

2011-01-01

We present a young woman with a negative medical history who presented with acute systemic lupus erythematosus (SLE) pneumonitis mimicking swine influenza (H1N1) pneumonia. Because this case occurred during the H1N1 pandemic, the initial diagnostic impression was of H1N1 pneumonia. Although her clinical and laboratory findings were consistent with the diagnosis of H1N1 pneumonia, e.g., fever, sore throat, dry cough, arthralgias, myalgias, thrombocytopenia, relative lymphopenia, and elevated serum transaminases, some findings suggested an alternate diagnosis, e.g., leukopenia, a highly elevated erythrocyte sedimentation rate, highly elevated serum ferritin levels, elevated antinuclear antibody (ANA) levels, and double-stranded (DS) DNA titers. Her chest x-ray showed an accentuation of basilar lung markings, with a small pleural effusion similar to the chest x-ray findings of early H1N1 pneumonia. Initially, her headaches were thought to be related to central nervous system manifestations of H1N1. After laboratory test results demonstrated elevated ANA and anti-DS DNA titers, she was diagnosed with acute SLE pneumonitis. The take-home lesson for clinicians is that other infectious diseases, e.g., human parainfluenza virus or Legionnaires' disease, can mimic H1N1 pneumonia during an influenza pandemic. Excluding asthma, congestive heart failure, exacerbations of acute bronchitis, chronic obstructive pulmonary disorder, and pulmonary interstitial disease, noninfectious mimics of H1N1 are extremely rare. To the best of our knowledge, this is the first reported case of de novo SLE pneumonitis mimicking H1N1 pneumonia during the swine influenza pandemic. Copyright © 2011 Elsevier Inc. All rights reserved.

MPC Design for Rapid Pump-Attenuation and Expedited Hyperglycemia Response to Treat T1DM with an Artificial Pancreas

PubMed Central

Gondhalekar, Ravi; Dassau, Eyal; Doyle, Francis J.

2016-01-01

The design of a Model Predictive Control (MPC) strategy for the closed-loop operation of an Artificial Pancreas (AP) for treating Type 1 Diabetes Mellitus (T1DM) is considered in this paper. The contribution of this paper is to propose two changes to the usual structure of the MPC problems typically considered for control of an AP. The first proposed change is to replace the symmetric, quadratic input cost function with an asymmetric, quadratic function, allowing negative control inputs to be penalized less than positive ones. This facilitates rapid pump-suspensions in response to predicted hypoglycemia, while simultaneously permitting the design of a conservative response to hyperglycemia. The second proposed change is to penalize the velocity of the predicted glucose level, where this velocity penalty is based on a cost function that is again asymmetric, but additionally state-dependent. This facilitates the accelerated response to acute, persistent hyperglycemic events, e.g., as induced by unannounced meals. The novel functionality is demonstrated by numerical examples, and the efficacy of the proposed MPC strategy verified using the University of Padova/Virginia metabolic simulator. PMID:28479660

Self-assembled nanoscale DNA-porphyrin complex for artificial light harvesting.

PubMed

Woller, Jakob G; Hannestad, Jonas K; Albinsson, Bo

2013-02-20

Mimicking green plants' and bacteria's extraordinary ability to absorb a vast number of photons and harness their energy is a longstanding goal in artificial photosynthesis. Resonance energy transfer among donor dyes has been shown to play a crucial role on the overall transfer of energy in the natural systems. Here, we present artificial, self-assembled, light-harvesting complexes consisting of DNA scaffolds, intercalated YO-PRO-1 (YO) donor dyes and a porphyrin acceptor anchored to a lipid bilayer, conceptually mimicking the natural light-harvesting systems. A model system consisting of 39-mer duplex DNA in a linear wire configuration with the porphyrin attached in the middle of the wire is primarily investigated. Utilizing intercalated donor fluorophores to sensitize the excitation of the porphyrin acceptor, we obtain an effective absorption coefficient 12 times larger than for direct excitation of the porphyrin. On the basis of steady-state and time-resolved emission measurements and Markov chain simulations, we show that YO-to-YO resonance energy transfer substantially contributes to the overall flow of energy to the porphyrin. This increase is explained through energy migration along the wire allowing the excited state energy to transfer to positions closer to the porphyrin. The versatility of DNA as a structural material is demonstrated through the construction of a more complex, hexagonal, light-harvesting scaffold yielding further increase in the effective absorption coefficient. Our results show that, by using DNA as a scaffold, we are able to arrange chromophores on a nanometer scale and in this way facilitate the assembly of efficient light-harvesting systems.

Polymerization of a divalent/tetravalent metal-storing atom-mimicking dendrimer.

PubMed

Albrecht, Ken; Hirabayashi, Yuki; Otake, Masaya; Mendori, Shin; Tobari, Yuta; Azuma, Yasuo; Majima, Yutaka; Yamamoto, Kimihisa

2016-12-01

The phenylazomethine dendrimer (DPA) has a layer-by-layer electron density gradient that is an analog of the Bohr atom (atom mimicry). In combination with electron pair mimicry, the polymerization of this atom-mimicking dendrimer was achieved. The valency of the mimicked atom was controlled by changing the chemical structure of the dendrimer. By mimicking a divalent atom, a one-dimensional (1D) polymer was obtained, and by using a planar tetravalent atom mimic, a 2D polymer was obtained. These poly(dendrimer) polymers could store Lewis acids (SnCl 2 ) in their unoccupied orbitals, thus indicating that these poly(dendrimer) polymers consist of a series of nanocontainers.

Pneumatically-actuated artificial cilia array for biomimetic fluid propulsion.

PubMed

Gorissen, Benjamin; de Volder, Michaël; Reynaerts, Dominiek

2015-11-21

Arrays of beating cilia emerged in nature as one of the most efficient propulsion mechanisms at a small scale, and are omnipresent in microorganisms. Previous attempts at mimicking these systems have foundered against the complexity of fabricating small-scale cilia exhibiting complex beating motions. In this paper, we propose for the first time arrays of pneumatically-actuated artificial cilia that are able to address some of these issues. These artificial cilia arrays consist of six highly flexible silicone rubber actuators with a diameter of 1 mm and a length of 8 mm that can be actuated independently from each other. In an experimental setup, the effects of the driving frequency, phase difference and duty cycle on the net flow in a closed-loop channel have been studied. Net fluid speeds of up to 19 mm s(-1) have been measured. Further, it is possible to invert the flow direction by simply changing the driving frequency or by changing the duty cycle of the driving block pulse pressure wave without changing the bending direction of the cilia. Using PIV measurements, we corroborate for the first time existing mathematical models of cilia arrays to measurements on prototypes.

Functional characterization of the heterodimeric sweet taste receptor T1R2 and T1R3 from a New World monkey species (squirrel monkey) and its response to sweet-tasting proteins

PubMed Central

Liu, Bo; Ha, Matthew; Meng, Xuan-Yu; Khaleduzzaman, Mohammed; Zhang, Zhe; Li, Xia; Cui, Meng

2012-01-01

The family C G protein-coupled receptor (GPCR) T1R2 and T1R3 heterodimer functions as a broadly acting sweet taste receptor. Perception of sweet taste is a species-dependent physiological process. It has been widely reported that New World monkeys and rodents can not perceive some of the artificial sweeteners and sweet-tasting proteins that can be perceived by humans, apes, and Old World monkeys. Until now, only the sweet receptors of humans, mice and rats have been functionally characterized. Here we report characterization of the sweet taste receptor (T1R2/T1R3) from a species of New World squirrel monkey. Our results show that the heterodimeric receptor of squirrel monkey does not respond to artificial sweeteners aspartame, neotame, cyclamate, saccharin and sweet-tasting protein monellin, but surprisingly, it does respond to thaumatin at high concentrations (>18 μM). This is the first report that New World monkey species can perceive some specific sweet-tasting proteins. Furthermore, the receptor responses to the sweeteners cannot be inhibited by the sweet inhibitor lactisole. We compared the response differences of the squirrel monkey and human receptors and found that the residues in T1R2 determine species-dependent sweet taste toward saccharin, while the residues in either T1R2 or T1R3 are responsible for the sweet taste difference between humans and squirrel monkeys toward monellin. Molecular models indicated that electrostatic properties of the receptors probably mediate the species-dependent response to sweet-tasting proteins. PMID:23000410

Artificial Sweeteners Stimulate Adipogenesis and Suppress Lipolysis Independently of Sweet Taste Receptors*

PubMed Central

Simon, Becky R.; Parlee, Sebastian D.; Learman, Brian S.; Mori, Hiroyuki; Scheller, Erica L.; Cawthorn, William P.; Ning, Xiaomin; Gallagher, Katherine; Tyrberg, Björn; Assadi-Porter, Fariba M.; Evans, Charles R.; MacDougald, Ormond A.

2013-01-01

G protein-coupled receptors mediate responses to a myriad of ligands, some of which regulate adipocyte differentiation and metabolism. The sweet taste receptors T1R2 and T1R3 are G protein-coupled receptors that function as carbohydrate sensors in taste buds, gut, and pancreas. Here we report that sweet taste receptors T1R2 and T1R3 are expressed throughout adipogenesis and in adipose tissues. Treatment of mouse and human precursor cells with artificial sweeteners, saccharin and acesulfame potassium, enhanced adipogenesis. Saccharin treatment of 3T3-L1 cells and primary mesenchymal stem cells rapidly stimulated phosphorylation of Akt and downstream targets with functions in adipogenesis such as cAMP-response element-binding protein and FOXO1; however, increased expression of peroxisome proliferator-activated receptor γ and CCAAT/enhancer-binding protein α was not observed until relatively late in differentiation. Saccharin-stimulated Akt phosphorylation at Thr-308 occurred within 5 min, was phosphatidylinositol 3-kinase-dependent, and occurred in the presence of high concentrations of insulin and dexamethasone; phosphorylation of Ser-473 occurred more gradually. Surprisingly, neither saccharin-stimulated adipogenesis nor Thr-308 phosphorylation was dependent on expression of T1R2 and/or T1R3, although Ser-473 phosphorylation was impaired in T1R2/T1R3 double knock-out precursors. In mature adipocytes, artificial sweetener treatment suppressed lipolysis even in the presence of forskolin, and lipolytic responses were correlated with phosphorylation of hormone-sensitive lipase. Suppression of lipolysis by saccharin in adipocytes was also independent of T1R2 and T1R3. These results suggest that some artificial sweeteners have previously uncharacterized metabolic effects on adipocyte differentiation and metabolism and that effects of artificial sweeteners on adipose tissue biology may be largely independent of the classical sweet taste receptors, T1R2 and T1R3. PMID

Artificial sweeteners stimulate adipogenesis and suppress lipolysis independently of sweet taste receptors.

PubMed

Simon, Becky R; Parlee, Sebastian D; Learman, Brian S; Mori, Hiroyuki; Scheller, Erica L; Cawthorn, William P; Ning, Xiaomin; Gallagher, Katherine; Tyrberg, Björn; Assadi-Porter, Fariba M; Evans, Charles R; MacDougald, Ormond A

2013-11-08

G protein-coupled receptors mediate responses to a myriad of ligands, some of which regulate adipocyte differentiation and metabolism. The sweet taste receptors T1R2 and T1R3 are G protein-coupled receptors that function as carbohydrate sensors in taste buds, gut, and pancreas. Here we report that sweet taste receptors T1R2 and T1R3 are expressed throughout adipogenesis and in adipose tissues. Treatment of mouse and human precursor cells with artificial sweeteners, saccharin and acesulfame potassium, enhanced adipogenesis. Saccharin treatment of 3T3-L1 cells and primary mesenchymal stem cells rapidly stimulated phosphorylation of Akt and downstream targets with functions in adipogenesis such as cAMP-response element-binding protein and FOXO1; however, increased expression of peroxisome proliferator-activated receptor γ and CCAAT/enhancer-binding protein α was not observed until relatively late in differentiation. Saccharin-stimulated Akt phosphorylation at Thr-308 occurred within 5 min, was phosphatidylinositol 3-kinase-dependent, and occurred in the presence of high concentrations of insulin and dexamethasone; phosphorylation of Ser-473 occurred more gradually. Surprisingly, neither saccharin-stimulated adipogenesis nor Thr-308 phosphorylation was dependent on expression of T1R2 and/or T1R3, although Ser-473 phosphorylation was impaired in T1R2/T1R3 double knock-out precursors. In mature adipocytes, artificial sweetener treatment suppressed lipolysis even in the presence of forskolin, and lipolytic responses were correlated with phosphorylation of hormone-sensitive lipase. Suppression of lipolysis by saccharin in adipocytes was also independent of T1R2 and T1R3. These results suggest that some artificial sweeteners have previously uncharacterized metabolic effects on adipocyte differentiation and metabolism and that effects of artificial sweeteners on adipose tissue biology may be largely independent of the classical sweet taste receptors, T1R2 and T1R3.

Bone tumor mimickers: A pictorial essay

PubMed Central

Mhuircheartaigh, Jennifer Ni; Lin, Yu-Ching; Wu, Jim S

2014-01-01

Focal lesions in bone are very common and many of these lesions are not bone tumors. These bone tumor mimickers can include numerous normal anatomic variants and non-neoplastic processes. Many of these tumor mimickers can be left alone, while others can be due to a significant disease process. It is important for the radiologist and clinician to be aware of these bone tumor mimickers and understand the characteristic features which allow discrimination between them and true neoplasms in order to avoid unnecessary additional workup. Knowing which lesions to leave alone or which ones require workup can prevent misdiagnosis and reduce patient anxiety. PMID:25114385

Role of nutrient-sensing taste 1 receptor (T1R) family members in gastrointestinal chemosensing.

PubMed

Shirazi-Beechey, Soraya P; Daly, Kristian; Al-Rammahi, Miran; Moran, Andrew W; Bravo, David

2014-06-01

Luminal nutrient sensing by G-protein-coupled receptors (GPCR) expressed on the apical domain of enteroendocrine cells activates intracellular pathways leading to secretion of gut hormones that control vital physiological processes such as digestion, absorption, food intake and glucose homeostasis. The taste 1 receptor (T1R) family of GPCR consists of three members: T1R1; T1R2; T1R3. Expression of T1R1, T1R2 and T1R3 at mRNA and protein levels has been demonstrated in the intestinal tissue of various species. It has been shown that T1R2-T1R3, in association with G-protein gustducin, is expressed in intestinal K and L endocrine cells, where it acts as the intestinal glucose (sweet) sensor. A number of studies have demonstrated that activation of T1R2-T1R3 by natural sugars and artificial sweeteners leads to secretion of glucagon-like peptides 1&2 (GLP-1 and GLP-2) and glucose dependent insulinotropic peptide (GIP). GLP-1 and GIP enhance insulin secretion; GLP-2 increases intestinal growth and glucose absorption. T1R1-T1R3 combination co-expressed on the apical domain of cholecystokinin (CCK) expressing cells is a luminal sensor for a number of L-amino acids; with amino acid-activation of the receptor eliciting CCK secretion. This article focuses on the role of the gut-expressed T1R1, T1R2 and T1R3 in intestinal sweet and L-amino acid sensing. The impact of exploiting T1R2-T1R3 as a nutritional target for enhancing intestinal glucose absorption and gut structural maturity in young animals is also highlighted.

T1R3 and gustducin in gut sense sugars to regulate expression of Na+-glucose cotransporter 1.

PubMed

Margolskee, Robert F; Dyer, Jane; Kokrashvili, Zaza; Salmon, Kieron S H; Ilegems, Erwin; Daly, Kristian; Maillet, Emeline L; Ninomiya, Yuzo; Mosinger, Bedrich; Shirazi-Beechey, Soraya P

2007-09-18

Dietary sugars are transported from the intestinal lumen into absorptive enterocytes by the sodium-dependent glucose transporter isoform 1 (SGLT1). Regulation of this protein is important for the provision of glucose to the body and avoidance of intestinal malabsorption. Although expression of SGLT1 is regulated by luminal monosaccharides, the luminal glucose sensor mediating this process was unknown. Here, we show that the sweet taste receptor subunit T1R3 and the taste G protein gustducin, expressed in enteroendocrine cells, underlie intestinal sugar sensing and regulation of SGLT1 mRNA and protein. Dietary sugar and artificial sweeteners increased SGLT1 mRNA and protein expression, and glucose absorptive capacity in wild-type mice, but not in knockout mice lacking T1R3 or alpha-gustducin. Artificial sweeteners, acting on sweet taste receptors expressed on enteroendocrine GLUTag cells, stimulated secretion of gut hormones implicated in SGLT1 up-regulation. Gut-expressed taste signaling elements involved in regulating SGLT1 expression could provide novel therapeutic targets for modulating the gut's capacity to absorb sugars, with implications for the prevention and/or treatment of malabsorption syndromes and diet-related disorders including diabetes and obesity.

Effects of artificial sweeteners on the AhR- and GR-dependent CYP1A1 expression in primary human hepatocytes and human cancer cells.

PubMed

Kamenickova, Alzbeta; Pecova, Michaela; Bachleda, Petr; Dvorak, Zdenek

2013-12-01

Food constituents may cause a phenomenon of food-drug interactions. In the current study, we examined the effects of artificial sweeteners (aspartame, acesulfame, cyclamate, saccharin) on the aryl hydrocarbon receptor (AhR) and glucocorticoid receptor (GR)-dependent expression of CYP1A1 in human hepatocytes, hepatic HepG2 and intestinal LS174T cancer cell lines. Sweeteners were tested in concentrations up to those occurring in non-alcoholic beverages. Basal and ligand-inducible AhR- and GR-dependent reporter gene activation in stably transfected HepG2 and HeLa cells, respectively, were not affected by either of the sweeteners tested after 24h of incubation. The expression of CYP1A1 mRNA and protein in primary cultures of human hepatocytes and in LS174T and HepG2 cells was not induced by any of the tested sweeteners. Overall, aspartame, acesulfame, saccharin and cyclamate had no effects on CYP1A1 expression and transcriptional activities of AhR and GR. These data imply the safety of artificial sweeteners in terms of interference with AhR, GR and CYP1A1. Copyright © 2013 Elsevier Ltd. All rights reserved.

Sensory motor systems of artificial and natural hands.

PubMed

Chappell, Paul H; Cranny, Andy; Cotton, Darryl P J; White, Neil M; Beeby, Steve P

2007-12-01

The surgeon Ambroise Paré designed an anthropomorphic hand for wounded soldiers in the 16th century. Since that time, there have been advances in technology through the use of computer-aided design, modern materials, electronic controllers and sensors to realise artificial hands which have good functionality and reliability. Data from touch, object slip, finger position and temperature sensors, mounted in the fingers and on the palm, can be used in feedback loops to automatically hold objects. A study of the natural neuromuscular systems reveals a complexity which can only in part be realised today with technology. Highlights of the parallels and differences between natural and artificial hands are discussed with reference to the Southampton Hand. The anatomical structure of parts of the natural systems can be made artificially such as the antagonist muscles using tendons. Theses solutions look promising as they are based on the natural form but in practice lack the desired physical specification. However, concepts of the lower spinal loops can be mimicked in principle. Some future devices will require greater skills from the surgeon to create the interface between the natural system and an artificial device. Such developments may offer a more natural control with ease of use for the limb deficient person.

Generation of mature T cells from human hematopoietic stem/progenitor cells in artificial thymic organoids

PubMed Central

Seet, Christopher S.; He, Chongbin; Bethune, Michael T.; Li, Suwen; Chick, Brent; Gschweng, Eric H.; Zhu, Yuhua; Kim, Kenneth; Kohn, Donald B.; Baltimore, David; Crooks, Gay M.; Montel-Hagen, Amélie

2017-01-01

Studies of human T cell development require robust model systems that recapitulate the full span of thymopoiesis, from hematopoietic stem and progenitor cells (HSPCs) through to mature T cells. Existing in vitro models induce T cell commitment from human HSPCs; however, differentiation into mature CD3+TCRab+ single positive (SP) CD8+ or CD4+ cells is limited. We describe here a serum-free, artificial thymic organoid (ATO) system that supports highly efficient and reproducible in vitro differentiation and positive selection of conventional human T cells from all sources of HSPCs. ATO-derived T cells exhibited mature naïve phenotypes, a diverse TCR repertoire, and TCR-dependent function. ATOs initiated with TCR-engineered HSPCs produced T cells with antigen specific cytotoxicity and near complete lack of endogenous TCR Vβ expression, consistent with allelic exclusion of Vβ loci. ATOs provide a robust tool for studying human T cell development and stem cell based approaches to engineered T cell therapies. PMID:28369043

Melorheostosis mimicking synovial osteochondromatosis.

PubMed

Wadhwa, Vibhor; Chhabra, Avneesh; Samet, Jonathan D

2014-01-01

Melorheostosis is an uncommon, sporadic, sclerosing bone lesion that may affect the adjacent soft tissues. It has been associated with many entities such as osteopoikilosis, soft tissue vascular malformations, bone and soft tissue tumors, nephrotic syndrome, segmental limb contractures, osteosarcoma, desmoid tumor, and mesenteric fibromatosis. Synovial osteochondromatosis is a benign neoplasia of the hyaline cartilage presenting as nodules in the subsynovial tissue of a joint or tendon sheath. The intra-articular extension of melorheostosis mimicking synovial osteochondromatosis has not been reported before. In this article, the authors describe an unusual case mimicking synovial chondromatosis arising as a result of melorheostosis and their characteristic imaging findings.

The Effect of Artificial Aging on the Tensile Properties of Alclad 24S-T and 24S-T Aluminum Alloy

NASA Technical Reports Server (NTRS)

Kotanchik, Joseph N.; Woods, Walter; Zender, George W.

1943-01-01

An experimental study was made to determine the effect of artificial aging on the tensile properties of alclad 24S-T and 24S-T aluminum-alloy sheet material. The results of the tests show that certain combinations of aging time and temperature cause a marked increase in the yield strength and a small increase in the ultimate strength; these increases are accompanied by a very large decrease in elongation. A curve is presented that shows the maximum yield strengths that can be obtained by aging this material at various combinations of time and temperature. The higher values of yield stress are obtained in material aged at relatively longer times and lower temperatures.

Dynamic Control of Topological Defects in Artificial Colloidal Ice

DOE PAGES

Libál, A.; Nisoli, C.; Reichhardt, C.; ...

2017-04-05

We demonstrate the use of an external field to stabilize and control defect lines connecting topological monopoles in spin ice. For definiteness we perform Brownian dynamics simulations with realistic units mimicking experimentally realized artificial colloidal spin ice systems, and show how defect lines can grow, shrink or move under the action of direct and alternating fields. Asymmetric alternating biasing forces can cause the defect line to ratchet in either direction, making it possible to precisely position the line at a desired location. Such manipulation could be employed to achieve mobile information storage in these metamaterials.

Dynamic Control of Topological Defects in Artificial Colloidal Ice

DOE Office of Scientific and Technical Information (OSTI.GOV)

Libál, A.; Nisoli, C.; Reichhardt, C.

We demonstrate the use of an external field to stabilize and control defect lines connecting topological monopoles in spin ice. For definiteness we perform Brownian dynamics simulations with realistic units mimicking experimentally realized artificial colloidal spin ice systems, and show how defect lines can grow, shrink or move under the action of direct and alternating fields. Asymmetric alternating biasing forces can cause the defect line to ratchet in either direction, making it possible to precisely position the line at a desired location. Such manipulation could be employed to achieve mobile information storage in these metamaterials.

Tinea capitis caused by Trichophyton rubrum mimicking favus.

PubMed

Boyd, Alan S

2016-12-01

Favus is an uncommon form of tinea capitis (TC) currently seen in geographic areas with poor sanitation and limited access to health care such as emerging nations. Several variants of this condition have been described including one exhibiting a plaque composed of parchmentlike material. The makeup of this plaque has not been described. Tinea capitis is rare in adults, particularly when the infectious agent is Trichophyton rubrum , and affected patients often exhibit comorbidities associated with diminished immune surveillance. This case report describes an elderly woman with TC due to T rubrum mimicking a rare form of favus.

Generation of mature T cells from human hematopoietic stem and progenitor cells in artificial thymic organoids.

PubMed

Seet, Christopher S; He, Chongbin; Bethune, Michael T; Li, Suwen; Chick, Brent; Gschweng, Eric H; Zhu, Yuhua; Kim, Kenneth; Kohn, Donald B; Baltimore, David; Crooks, Gay M; Montel-Hagen, Amélie

2017-05-01

Studies of human T cell development require robust model systems that recapitulate the full span of thymopoiesis, from hematopoietic stem and progenitor cells (HSPCs) through to mature T cells. Existing in vitro models induce T cell commitment from human HSPCs; however, differentiation into mature CD3 + TCR-αβ + single-positive CD8 + or CD4 + cells is limited. We describe here a serum-free, artificial thymic organoid (ATO) system that supports efficient and reproducible in vitro differentiation and positive selection of conventional human T cells from all sources of HSPCs. ATO-derived T cells exhibited mature naive phenotypes, a diverse T cell receptor (TCR) repertoire and TCR-dependent function. ATOs initiated with TCR-engineered HSPCs produced T cells with antigen-specific cytotoxicity and near-complete lack of endogenous TCR Vβ expression, consistent with allelic exclusion of Vβ-encoding loci. ATOs provide a robust tool for studying human T cell differentiation and for the future development of stem-cell-based engineered T cell therapies.

Striking volume intolerance is induced by mimicking arterial baroreflex failure in normal left ventricular function.

PubMed

Funakoshi, Kouta; Hosokawa, Kazuya; Kishi, Takuya; Ide, Tomomi; Sunagawa, Kenji

2014-01-01

Patients with heart failure and preserved ejection fraction (HFpEF) are supersensitive to volume overload, and a striking increase in left atrial pressure (LAP) often occurs transiently and is rapidly resolved by intravascular volume reduction. The arterial baroreflex is a powerful regulator of intravascular stressed blood volume. We examined whether arterial baroreflex failure (FAIL) mimicked by constant carotid sinus pressure (CSP) causes a striking increase in LAP and systemic arterial pressure (AP) by volume loading in rats with normal left ventricular (LV) function. In anesthetized Sprague-Dawley rats, we isolated bilateral carotid sinuses and controlled CSP by a servo-controlled piston pump. We mimicked the normal arterial baroreflex by matching CSP to instantaneous AP and FAIL by maintaining CSP at a constant value regardless of AP. We infused dextran stepwise (infused volume [Vi]) until LAP reached 15 mm Hg and obtained the LAP-Vi relationship. We estimated the critical Vi as the Vi at which LAP reached 20 mm Hg. In FAIL, critical Vi decreased markedly from 19.4 ± 1.6 mL/kg to 15.6 ± 1.6 mL/kg (P < .01), whereas AP at the critical Vi increased (194 ± 6 mm Hg vs 163 ± 6 mm Hg; P < .01). We demonstrated that an artificial arterial baroreflex system we recently developed could fully restore the physiologic volume intolerance in the absence of native arterial baroreflex. Arterial baroreflex failure induces striking volume intolerance in the absence of LV dysfunction and may play an important role in the pathogenesis of acute heart failure, especially in states of HFpEF. Copyright © 2014 Elsevier Inc. All rights reserved.

Peptide microarray profiling identifies phospholipase C gamma 1 (PLC-γ1) as a potential target for t(8;21) AML

PubMed Central

Mahmud, Hasan; Scherpen, Frank J.G.; de Boer, Tiny Meeuwsen; Lourens, Harm-Jan; Schoenherr, Caroline; Eder, Matthias; Scherr, Michaela; Guryev, Victor; De Bont, Eveline S.

2017-01-01

The t(8;21) (q22;q22) chromosomal translocation is one of the most frequent genetic alterations in acute myeloid leukemia (AML) which has a need for improved therapeutic strategies. We found PLC-γ1 as one of the highest phosphorylated peptides in t(8;21) AML samples compared to NBM or CN-AML in our previous peptide microarray. PLC-γ1 is known to play a role in cancer progression, however, the impact of PLC-γ1 in AML is currently unknown. Therefore, we aimed to study the functional role of PLC-γ1 by investigating the cellular growth, survival and its underlying mechanism in t(8;21) AML. In this study, PLC-γ1 expression was significantly higher in t(8;21) AML compared to other karyotypes. The PLC-γ1 protein expression was suppressed in AML1-ETO knock down cells indicating that it might induce kasumi-1 cell death. ShRNA-mediated PLC-γ1 knockdown in kasumi-1 cells significantly blocked cell growth, induced apoptosis and cell cycle arrest which was explained by the increased activation of apoptotic related and cell cycle regulatory protein expressions. Gene expression array analysis showed the up-regulation of apoptotic and DNA damage response genes together with the downregulation of cell growth, proliferation and differentiation genes in the PLC-γ1 suppressed kasumi-1 cells, consistent with the observed phenotypic effects. Importantly, PLC-γ1 suppressed kasumi-1 cells showed higher chemosensitivity to the chemotherapeutic drug treatments and lower cell proliferation upon hypoxic stress. Taken together, these in vitro finding strongly support an important role for PLC-γ1 in the survival of t(8;21) AML mimicking kasumi-1 cells and identify PLC-γ1 as a potential therapeutic target for t(8;21) AML treatment. PMID:28978037

Magnetic vortex nucleation/annihilation in artificial-ferrimagnet microdisks

DOE PAGES

Lapa, Pavel N.; Ding, Junjia; Phatak, Charudatta; ...

2017-08-28

The topological nature of magnetic-vortex state gives rise to peculiar magnetization reversal observed in magnetic microdisks. Interestingly, magnetostatic and exchange energies which drive this reversal can be effectively controlled in artificial ferrimagnet heterostructures composed of rare-earth and transition metals. [Py(t)/Gd(t)] 25 (t=1 or 2 nm) superlattices demonstrate a pronounced change of the magnetization and exchange stiffness in a 10–300 K temperature range as well as very small magnetic anisotropy. Due to these properties, the magnetization of cylindrical microdisks composed of these artificial ferrimagnets can be transformed from the vortex to uniformly-magnetized states in a permanent magnetic field by changing themore » temperature. We explored the behavior of magnetization in 1.5-µm [Py(t)/Gd(t)] 25 (t=1 or 2 nm) disks at different temperatures and magnetic fields and observed that due to the energy barrier separating vortex and uniformly-magnetized states, the vortex nucleation and annihilation occur at different temperatures. This causes the temperature dependences of the Py/Gd disks magnetization to demonstrate unique hysteretic behavior in a narrow temperature range. It was discovered that for the [Py(2 nm)/Gd(2 nm)] 25 microdisks the vortex can be metastable at a certain temperature range.« less

Magnetic vortex nucleation/annihilation in artificial-ferrimagnet microdisks

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lapa, Pavel N.; Ding, Junjia; Phatak, Charudatta

The topological nature of magnetic-vortex state gives rise to peculiar magnetization reversal observed in magnetic microdisks. Interestingly, magnetostatic and exchange energies which drive this reversal can be effectively controlled in artificial ferrimagnet heterostructures composed of rare-earth and transition metals. [Py(t)/Gd(t)] 25 (t=1 or 2 nm) superlattices demonstrate a pronounced change of the magnetization and exchange stiffness in a 10–300 K temperature range as well as very small magnetic anisotropy. Due to these properties, the magnetization of cylindrical microdisks composed of these artificial ferrimagnets can be transformed from the vortex to uniformly-magnetized states in a permanent magnetic field by changing themore » temperature. We explored the behavior of magnetization in 1.5-µm [Py(t)/Gd(t)] 25 (t=1 or 2 nm) disks at different temperatures and magnetic fields and observed that due to the energy barrier separating vortex and uniformly-magnetized states, the vortex nucleation and annihilation occur at different temperatures. This causes the temperature dependences of the Py/Gd disks magnetization to demonstrate unique hysteretic behavior in a narrow temperature range. It was discovered that for the [Py(2 nm)/Gd(2 nm)] 25 microdisks the vortex can be metastable at a certain temperature range.« less

Engineering artificial cells by combining HeLa-based cell-free expression and ultra-thin double emulsion template

PubMed Central

Ho, Kwun Yin; Murray, Victoria L.; Liu, Allen P.

2015-01-01

Generation of artificial cells provides the bridge needed to cover the gap between studying the complexity of biological processes in whole cells and studying these same processes in an in vitro reconstituted system. Artificial cells are defined as the encapsulation of biologically active material in a biological or synthetic membrane. Here, we describe a robust and general method to produce artificial cells for the purpose of mimicking one or more behaviors of a cell. A microfluidic double emulsion system is used to encapsulate a mammalian cell free expression system that is able to express membrane proteins into the bilayer or soluble proteins inside the vesicles. The development of a robust platform that allows the assembly of artificial cells is valuable in understanding subcellular functions and emergent behaviors in a more cell-like environment as well as for creating novel signaling pathways to achieve specific cellular behaviors. PMID:25997354

Northeast Artificial Intelligence Consortium (NAIC) Review of Technical Tasks. Volume 2, Part 2.

DTIC Science & Technology

1987-07-01

A-A19 774 NORTHEAST ARTIFICIAL INTELLIGENCE CONSORTIUN (MIC) 1/5 YVIEN OF TEOICR. T.. (U) NORTHEAST ARTIFICIAL INTELLIGENCE CONSORTIUM SYRACUSE MY J...NORTHEAST ARTIFICIAL INTELLIGENCE CONSORTIUM (NAIC) *p,* ~ Review of Technical Tasks ,.. 12 PERSONAL AUTHOR(S) (See reverse) . P VI J.F. Allen, P.B. Berra...See reverse) /" I ABSTRACT (Coninue on ’.wrse if necessary and identify by block number) % .. *. -. ’ The Northeast Artificial Intelligence Consortium

A novel system of artificial antigen-presenting cells efficiently stimulates Flu peptide-specific cytotoxic T cells in vitro

DOE Office of Scientific and Technical Information (OSTI.GOV)

Han, Hui; Peng, Ji-Run, E-mail: pengjr@medmail.com.cn; Chen, Peng-Cheng

Highlights: {yields} Adoptive immunotherapy depends on relevant numbers of cytolytic T lymphocytes. {yields} An ideal artificial APCs system was successfully prepared in vivo. {yields} Controlled release of IL-2 leads to much more T-cell expansion. {yields} This system is better than general cellular APCs on T-cell expansion. -- Abstract: Therapeutic numbers of antigen-specific cytotoxic T lymphocytes (CTLs) are key effectors in successful adoptive immunotherapy. However, efficient and reproducible methods to meet the qualification remain poor. To address this issue, we designed the artificial antigen-presenting cell (aAPC) system based on poly(lactic-co-glycolic acid) (PLGA). A modified emulsion method was used for the preparationmore » of PLGA particles encapsulating interleukin-2 (IL-2). Biotinylated molecular ligands for recognition and co-stimulation of T cells were attached to the particle surface through the binding of avidin-biotin. These formed the aAPC system. The function of aAPCs in the proliferation of specific CTLs against human Flu antigen was detected by enzyme-linked immunospot assay (ELISPOT) and MTT staining methods. Finally, we successfully prepared this suitable aAPC system. The results show that IL-2 is released from aAPCs in a sustained manner over 30 days. This dramatically improves the stimulatory capacity of this system as compared to the effect of exogenous addition of cytokine. In addition, our aAPCs promote the proliferation of Flu antigen-specific CTLs more effectively than the autologous cellular APCs. Here, this aAPC platform is proved to be suitable for expansion of human antigen-specific T cells.« less

Metastatic breast cancer to the liver with hepatoid features and Hep Par 1 antibody positive mimicking hepatocellular carcinoma.

PubMed

Affleck, Authur; Lyman, William B; Jacobs, W Carl; Livasy, Chad A; Martinie, John B; Iannitti, David A; Vrochides, Dionisios

2018-05-09

The hepatocyte paraffin 1 antibody (Hep Par 1) has a high positive predictive value for differentiating hepatocellular carcinoma from cholangiocarcinoma and metastatic carcinoma. 1 We report a case of metastatic breast cancer to the liver with hepatoid histology and strong positive staining for Hep Par 1 mimicking hepatocellular carcinoma. To our knowledge, primary breast carcinoma staining Hep Par 1 positive has not been reported in the setting of hepatic metastasis. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Subdural Hematoma Mimickers: A Systematic Review.

PubMed

Catana, Dragos; Koziarz, Alex; Cenic, Aleksa; Nath, Siddharth; Singh, Sheila; Almenawer, Saleh A; Kachur, Edward

2016-09-01

A variety of subdural pathologies that may mimic hematomas are reported in the literature. We aimed to identify the atypical clinical and radiologic presentations of subdural masses that may mimic subdural hematomas. A systematic review of MEDLINE and Embase was conducted independently by 2 reviewers to identify articles describing subdural hematoma mimickers. We also present a patient from our institution with a subdural pathology mimicking a subdural hematoma. We analyzed patient clinical presentations, underlying pathologies, radiologic findings, and clinical outcomes. We included 43 articles totaling 48 patients. The mean ± SD patient age was 55.7 ± 16.8 years. Of the 45 cases describing patient history, 13 patients (27%) had a history of trauma. The underlying pathologies of the 48 subdural collections were 10 metastasis (21%), 14 lymphoma (29%), 7 sarcoma (15%), 4 infectious (8%), 4 autoimmune (8%), and 9 miscellaneous (19%). Findings on computed tomography (CT) scan were 18 hyperdense (41%), 11 hypodense (25%), 9 isodense (20%), 3 isodense/hyperdense (7%), and 3 hypodense/isodense (7%). Thirty-four patients (71%) were treated surgically; among these patients, 65% had symptom resolution. Neither the pathology (P = 0.337) nor the management strategy (P = 0.671) was correlated with improved functional outcomes. Identification of atypical history and radiologic features should prompt further diagnostic tests, including magnetic resonance imaging (MRI), to elucidate the proper diagnosis, given that certain pathologies may be managed nonsurgically. A subdural collection that is hyperdense on CT scan and hyperintense on T2-weighted MRI, along with a history of progressive headache with no trauma, may raise the suspicion of an atypical subdural pathology. Copyright © 2016 Elsevier Inc. All rights reserved.

A heterogeneous human tissue mimicking phantom for RF heating and MRI thermal monitoring verification

NASA Astrophysics Data System (ADS)

Yuan, Yu; Wyatt, Cory; Maccarini, Paolo; Stauffer, Paul; Craciunescu, Oana; MacFall, James; Dewhirst, Mark; Das, Shiva K.

2012-04-01

This paper describes a heterogeneous phantom that mimics a human thigh with a deep-seated tumor, for the purpose of studying the performance of radiofrequency (RF) heating equipment and non-invasive temperature monitoring with magnetic resonance imaging (MRI). The heterogeneous cylindrical phantom was constructed with an outer fat layer surrounding an inner core of phantom material mimicking muscle, tumor and marrow-filled bone. The component materials were formulated to have dielectric and thermal properties similar to human tissues. The dielectric properties of the tissue mimicking phantom materials were measured with a microwave vector network analyzer and impedance probe over the frequency range of 80-500 MHz and at temperatures of 24, 37 and 45 °C. The specific heat values of the component materials were measured using a differential scanning calorimeter over the temperature range of 15-55 °C. The thermal conductivity value was obtained from fitting the curves obtained from one-dimensional heat transfer measurement. The phantom was used to verify the operation of a cylindrical four-antenna annular phased array extremity applicator (140 MHz) by examining the proton resonance frequency shift (PRFS) thermal imaging patterns for various magnitude/phase settings (including settings to focus heating in tumors). For muscle and tumor materials, MRI was also used to measure T1/T2* values (1.5 T) and to obtain the slope of the PRFS phase change versus temperature change curve. The dielectric and thermal properties of the phantom materials were in close agreement to well-accepted published results for human tissues. The phantom was able to successfully demonstrate satisfactory operation of the tested heating equipment. The MRI-measured thermal distributions matched the expected patterns for various magnitude/phase settings of the applicator, allowing the phantom to be used as a quality assurance tool. Importantly, the material formulations for the various tissue types

Artificial Intelligence Information Sources for the Beginner and Expert

DTIC Science & Technology

1991-05-01

SUBPLEETAR TMS T bepbhdi" Artificial Intelligence ApplictionsforMlitar Expertis SystemsWilasbrVA 527Mrh 91 12a. DSCRIBTION C AIITY 6 STAEENRTY CTO SECb.T...DLSIFC ISTR BUMATION OC Apnclassified pu ncrlase; ituied inlsife unlimited. Artificial Intelligence Information Sources for the Beginner and Expert...mgivenfdsac.dia.mil UUCP: {...).osu-cisidsac!mgiven ABSTRACT A tremendous amount of information on artificial intelligence is available via different

Tissue mimicking materials for dental ultrasound

PubMed Central

Singh, Rahul S.; Culjat, Martin O.; Grundfest, Warren S.; Brown, Elliott R.; White, Shane N.

2008-01-01

While acoustic tissue mimicking materials have been explored for a variety of soft and hard biological tissues, no dental hard tissue mimicking materials have been characterized. Tooth phantoms are necessary to better understand acoustic phenomenology within the tooth environment and to accelerate the advancement of dental ultrasound imaging systems. In this study, soda lime glass and dental composite were explored as surrogates for human enamel and dentin, respectively, in terms of compressional velocity, attenuation, and acoustic impedance. The results suggest that a tooth phantom consisting of glass and composite can effectively mimic the acoustic behavior of a natural human tooth. PMID:18396919

Restless legs syndrome mimicking S1 radiculopathy.

PubMed

Zambelis, Th; Wolgamuth, B R; Papoutsi, S N; Economou, N T

2016-01-01

mimicking several pathological conditions, Restless Legs Syndrome prevalence on general population according to various large epidemiological studies and pathogenic hypotheses on the issue of Restless Legs Syndrome are discussed. Finally, by presenting another possible "RLS-mimic" our aim is to highlight the common misdiagnosis of Restless Legs Syndrome, which can mimic a variety of disorders, some of which are very common, such as an S1 radiculopathy, thus raising concern among doctors of various specialties addressed to by Restless Legs Syndrome sufferers, on the importance of proper diagnosis of the syndrome.

Artificial Synaptic Devices Based on Natural Chicken Albumen Coupled Electric-Double-Layer Transistors

NASA Astrophysics Data System (ADS)

Wu, Guodong; Feng, Ping; Wan, Xiang; Zhu, Liqiang; Shi, Yi; Wan, Qing

2016-03-01

Recent progress in using biomaterials to fabricate functional electronics has got growing attention for the new generation of environmentally friendly and biocompatible electronic devices. As a kind of biological material with rich source, proteins are essential natural component of all organisms. At the same time, artificial synaptic devices are of great significance for neuromorphic systems because they can emulate the signal process and memory behaviors of biological synapses. In this report, natural chicken albumen with high proton conductivity was used as the coupling electrolyte film for organic/inorganic hybrid synaptic devices fabrication. Some important synaptic functions including paired-pulse facilitation, dynamic filtering, short-term to long-term memory transition and spatial summation and shunting inhibition were successfully mimicked. Our results are very interesting for biological friendly artificial neuron networks and neuromorphic systems.

Biomimetic actuators using electroactive polymers (EAP) as artificial muscles

NASA Technical Reports Server (NTRS)

Bar-Cohen, Yoseph

2006-01-01

Evolution has resolved many of nature's challenges leading to lasting solutions with maximal performance and effective use of resources. Nature's inventions have always inspired human achievements leading to effective materials, structures, tools, mechanisms, processes, algorithms, methods, systems and many other benefits. The field of mimicking nature is known as Biomimetics and one of its topics includes electroactive polymers that gain the moniker artificial muscles. Integrating EAP with embedded sensors, self-repair and many other capabilities that are used in composite materials can add greatly to the capability of smart biomimetic systems. Such development would enable fascinating possibilities potentially turning science fiction ideas into engineering reality.

Obtaining T1-T2 distribution functions from 1-dimensional T1 and T2 measurements: The pseudo 2-D relaxation model

NASA Astrophysics Data System (ADS)

Williamson, Nathan H.; Röding, Magnus; Galvosas, Petrik; Miklavcic, Stanley J.; Nydén, Magnus

2016-08-01

We present the pseudo 2-D relaxation model (P2DRM), a method to estimate multidimensional probability distributions of material parameters from independent 1-D measurements. We illustrate its use on 1-D T1 and T2 relaxation measurements of saturated rock and evaluate it on both simulated and experimental T1-T2 correlation measurement data sets. Results were in excellent agreement with the actual, known 2-D distribution in the case of the simulated data set. In both the simulated and experimental case, the functional relationships between T1 and T2 were in good agreement with the T1-T2 correlation maps from the 2-D inverse Laplace transform of the full 2-D data sets. When a 1-D CPMG experiment is combined with a rapid T1 measurement, the P2DRM provides a double-shot method for obtaining a T1-T2 relationship, with significantly decreased experimental time in comparison to the full T1-T2 correlation measurement.

Natural and Artificial Mn4 Ca Cluster for the Water Splitting Reaction.

PubMed

Chen, Changhui; Li, Yanxi; Zhao, Guoqing; Yao, Ruoqing; Zhang, Chunxi

2017-11-23

The oxygen-evolving center (OEC) in photosystem II (PSII) is a unique biological catalyst that splits water into electrons, protons, and O 2 by using solar energy. Recent crystallographic studies have revealed that the structure of the OEC is an asymmetric Mn 4 Ca cluster, which provides a blueprint to develop man-made water-splitting catalysts for artificial photosynthesis. Although it is a great challenge to mimic the whole structure and function of the OEC in the laboratory, significant advances have recently been achieved. In this Minireview, recent progress on mimicking the natural OEC is discussed. New strategies are suggested to construct more stable and efficient new generation of catalytic materials for the water splitting reaction based on the artificial Mn 4 Ca cluster in the future. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Disruption of behavior and brain metabolism in artificially reared rats.

PubMed

Aguirre-Benítez, Elsa L; Porras, Mercedes G; Parra, Leticia; González-Ríos, Jacquelina; Garduño-Torres, Dafne F; Albores-García, Damaris; Avendaño, Arturo; Ávila-Rodríguez, Miguel A; Melo, Angel I; Jiménez-Estrada, Ismael; Mendoza-Garrido, Ma Eugenia; Toriz, César; Diaz, Daniel; Ibarra-Coronado, Elizabeth; Mendoza-Ángeles, Karina; Hernández-Falcón, Jesús

2017-12-01

Early adverse life stress has been associated to behavioral disorders that can manifest as inappropriate or aggressive responses to social challenges. In this study, we analyzed the effects of artificial rearing on the open field and burial behavioral tests and on GFAP, c-Fos immunoreactivity, and glucose metabolism measured in anxiety-related brain areas. Artificial rearing of male rats was performed by supplying artificial milk through a cheek cannula and tactile stimulation, mimicking the mother's licking to rat pups from the fourth postnatal day until weaning. Tactile stimulation was applied twice a day, at morning and at night, by means of a camel brush on the rat anogenital area. As compared to mother reared rats, greater aggressiveness, and boldness, stereotyped behavior (burial conduct) was observed in artificially reared rats which occurred in parallel to a reduction of GFAP immunoreactivity in somatosensory cortex, c-Fos immunoreactivity at the amygdala and primary somatosensory cortex, and lower metabolism in amygdala (as measured by 2-deoxi-2-[ 18 fluoro]-d-glucose uptake, assessed by microPET imaging). These results could suggest that tactile and/or chemical stimuli from the mother and littermates carry relevant information for the proper development of the central nervous system, particularly in brain areas involved with emotions and social relationships of the rat. © 2017 Wiley Periodicals, Inc. Develop Neurobiol 77: 1413-1429, 2017. © 2017 Wiley Periodicals, Inc.

Double control systems for human T-cell leukemia virus type 1 by innate and acquired immunity.

PubMed

Kannagi, Mari; Hasegawa, Atsuhiko; Kinpara, Shuichi; Shimizu, Yukiko; Takamori, Ayako; Utsunomiya, Atae

2011-04-01

Human T-cell leukemia virus type 1 (HTLV-1) is the causative retrovirus of adult T-cell leukemia (ATL) and HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). HTLV-1-specific T-cell responses elicit antitumor and antiviral effects in experimental models, and are considered to be one of the most important determinants of the disease manifestation, since they are activated in HAM/TSP but not in ATL patients. The combination of low T-cell responses and elevated HTLV-1 proviral loads are features of ATL, and are also observed in a subpopulation of HTLV-1 carriers at the asymptomatic stage, suggesting that these features may be underlying risk factors. These risks may potentially be reduced by vaccination to activate HTLV-1-specific T-cell responses. HAM/TSP and ATL patients also differ in their levels of HTLV-1 mRNA expression, which are generally low in vivo but slightly higher in HAM/TSP patients. Our recent study indicated that viral expression in HTLV-1-infected T-cells is suppressed by stromal cells in culture through type-I IFNs. The suppression was reversible after isolation from the stromal cells, mimicking a long-standing puzzling phenomenon in HTLV-1 infection where the viral expression is very low in vivo and rapidly induced in vitro. Collectively, HTLV-1 is controlled by both acquired and innate immunity in vivo: HTLV-1-specific T-cells survey infected cells, and IFNs suppress viral expression. Both effects would contribute to a reduction in viral pathogenesis, although they may potentially influence or conflict with one another. The presence of double control systems for HTLV-1 infection provides a new concept for understanding the pathogenesis of HTLV-1-mediated malignant and inflammatory diseases. © 2011 Japanese Cancer Association.

Mimicking Nonequilibrium Steady States with Time-Periodic Driving

NASA Astrophysics Data System (ADS)

Raz, O.; Subaşı, Y.; Jarzynski, C.

2016-04-01

Under static conditions, a system satisfying detailed balance generically relaxes to an equilibrium state in which there are no currents. To generate persistent currents, either detailed balance must be broken or the system must be driven in a time-dependent manner. A stationary system that violates detailed balance evolves to a nonequilibrium steady state (NESS) characterized by fixed currents. Conversely, a system that satisfies instantaneous detailed balance but is driven by the time-periodic variation of external parameters—also known as a stochastic pump (SP)—reaches a periodic state with nonvanishing currents. In both cases, these currents are maintained at the cost of entropy production. Are these two paradigmatic scenarios effectively equivalent? For discrete-state systems, we establish a mapping between nonequilibrium stationary states and stochastic pumps. Given a NESS characterized by a particular set of stationary probabilities, currents, and entropy production rates, we show how to construct a SP with exactly the same (time-averaged) values. The mapping works in the opposite direction as well. These results establish a proof of principle: They show that stochastic pumps are able to mimic the behavior of nonequilibrium steady states, and vice versa, within the theoretical framework of discrete-state stochastic thermodynamics. Nonequilibrium steady states and stochastic pumps are often used to model, respectively, biomolecular motors driven by chemical reactions and artificial molecular machines steered by the variation of external, macroscopic parameters. Our results loosely suggest that anything a biomolecular machine can do, an artificial molecular machine can do equally well. We illustrate this principle by showing that kinetic proofreading, a NESS mechanism that explains the low error rates in biochemical reactions, can be effectively mimicked by a constrained periodic driving.

Mutagenesis Screen Identifies agtpbp1 and eps15L1 as Essential for T lymphocyte Development in Zebrafish.

PubMed

Seiler, Christoph; Gebhart, Nichole; Zhang, Yong; Shinton, Susan A; Li, Yue-sheng; Ross, Nicola L; Liu, Xingjun; Li, Qin; Bilbee, Alison N; Varshney, Gaurav K; LaFave, Matthew C; Burgess, Shawn M; Balciuniene, Jorune; Balciunas, Darius; Hardy, Richard R; Kappes, Dietmar J; Wiest, David L; Rhodes, Jennifer

2015-01-01

Genetic screens are a powerful tool to discover genes that are important in immune cell development and function. The evolutionarily conserved development of lymphoid cells paired with the genetic tractability of zebrafish make this a powerful model system for this purpose. We used a Tol2-based gene-breaking transposon to induce mutations in the zebrafish (Danio rerio, AB strain) genome, which served the dual purpose of fluorescently tagging cells and tissues that express the disrupted gene and provided a means of identifying the disrupted gene. We identified 12 lines in which hematopoietic tissues expressed green fluorescent protein (GFP) during embryonic development, as detected by microscopy. Subsequent analysis of young adult fish, using a novel approach in which single cell suspensions of whole fish were analyzed by flow cytometry, revealed that 8 of these lines also exhibited GFP expression in young adult cells. An additional 15 lines that did not have embryonic GFP+ hematopoietic tissue by microscopy, nevertheless exhibited GFP+ cells in young adults. RT-PCR analysis of purified GFP+ populations for expression of T and B cell-specific markers identified 18 lines in which T and/or B cells were fluorescently tagged at 6 weeks of age. As transposon insertion is expected to cause gene disruption, these lines can be used to assess the requirement for the disrupted genes in immune cell development. Focusing on the lines with embryonic GFP+ hematopoietic tissue, we identified three lines in which homozygous mutants exhibited impaired T cell development at 6 days of age. In two of the lines we identified the disrupted genes, agtpbp1 and eps15L1. Morpholino-mediated knockdown of these genes mimicked the T cell defects in the corresponding mutant embryos, demonstrating the previously unrecognized, essential roles of agtpbp1 and eps15L1 in T cell development.

Artificial gait in complete spinal cord injured subjects: how to assess clinical performance.

PubMed

Pithon, Karla Rocha; Abreu, Daniela Cristina Carvalho de; Vasconcelos-Neto, Renata; Martins, Luiz Eduardo Barreto; Cliquet, Alberto

2015-02-01

Adapt the 6 minutes walking test (6MWT) to artificial gait in complete spinal cord injured (SCI) patients aided by neuromuscular electrical stimulation. Nine male individuals with paraplegia (AIS A) participated in this study. Lesion levels varied between T4 and T12 and time post injured from 4 to 13 years. Patients performed 6MWT 1 and 6MWT 2. They used neuromuscular electrical stimulation, and were aided by a walker. The differences between two 6MWT were assessed by using a paired t test. Multiple r-squared was also calculated. The 6MWT 1 and 6MWT 2 were not statistically different for heart rate, distance, mean speed and blood pressure. Multiple r-squared (r2 = 0.96) explained 96% of the variation in the distance walked. The use of 6MWT in artificial gait towards assessing exercise walking capacity is reproducible and easy to apply. It can be used to assess SCI artificial gait clinical performance.

Fabrication of Artificial Leaf to Develop Fluid Pump Driven by Surface Tension and Evaporation

NASA Astrophysics Data System (ADS)

Lee, Minki; Lim, Hosub; Lee, Jinkee

2017-11-01

Plants transport water from roots to leaves via xylem through transpiration, which is an evaporation process that occurs at the leaves. During transpiration, negative pressure can be generated by the porous structure of mesophyll cells in the leaves. Here, an artificial leaf mimicking structure using hydrogel, which has a nanoporous structure is fabricated. The cryogel method is used to develop a hierarchy structure on the nano- and microscale in the hydrogel media that is similar to the mesophyll cells and veins of a leaf, respectively. The theoretical model is analyzed to calculate the flow resistance in the artificial leaf, and compare the model with the experimental results. The experiment involves connecting a glass capillary tube at the bottom of the artificial leaf to observe the fluid velocity in the glass capillary tube generated by the negative pressure. The use of silicone oil as fluid instead of water to increase the flow resistance enables the measurement of negative pressure. The negative pressure of the artificial leaf is affected by several variables (e.g., pore size, wettability of the structure). Finally, by decreasing the pore size and increasing the wettability, the maximum negative pressure of the artificial leaf, -7.9 kPa is obtained.

Rare extraskeletal Ewing's sarcoma mimicking as adenocarcinoma of the sigmoid.

PubMed

Mertens, Michelle; Haenen, Filip W N; Siozopoulou, Vasiliki; Van Cleemput, Marc

2017-06-01

Extraskeletal Ewing's sarcoma (EES) is a rare finding in comparison with Ewing's sarcoma of bone and usually manifests in young patients. However, even in older patients, one must consider the diagnosis. In this case, we describe a 52-year-old woman diagnosed with EES, mimicking as adenocarcinoma of the sigmoid. The tumor was not visualized by a multi-slice spiral computed tomography of the abdomen and pelvis with intravenous contrast, and eventually the diagnosis was made by positive immunohistochemical staining for CD99 and by molecular testing for EWSR1 translocation. This combination of the patient's age and the localization of the tumor mimicking an adenocarcinoma of the sigmoid has never been described before.

Generalized myositis mimicking polymyositis associated with chronic active Epstein-Barr virus infection.

PubMed

Uchiyama, Tomoyuki; Arai, Kimito; Yamamoto-Tabata, Takako; Hirai, Kanji; Kishimoto, Kouji; Nakamura, Yoshiko; Hattori, Takamichi

2005-05-01

Chronic generalized myositis has not so far been reported as a complication of chronic active Epstein-Barr virus infection (CAEBV). We encountered three patients with chronic generalized myositis mimicking polymyositis associated with CAEBV. To clarify the pathological character of this myositis, we investigated the distribution, clonality, and the immunophenotype of EBV-infected cells and lymphocytes infiltrating in muscles. Clinically, two patients showed symmetrical proximal weakness and muscle atrophy as the initial and main symptom. Although the condition resembled polymyositis, they had also lingual and/or orbital myositis. The other patient showed generalized myositis at the late phase of CAEBV. In all of them, immunotherapy was ineffective and prognosis was poor. Intramuscular infiltrating lymphocytes in our patients were mainly CD45RO+, CD3+, CD4-, CD8-, TCR betaF1-, TCR deltaTCS1-, CD56-, CD79a-, CD21-, HLA-DR+, ZEBRA -, LMP1-, and EBER+ T cells. Oligoclonal expansion of EBV-infected T cells was shown in the muscles. However, there were no malignant lymphocytes. This new form of myositis must be distinguished from polymyositis and the other conventional forms of myositis. Careful investigation of hidden CAEBV is recommended when patients present with steroid non-responsive chronic progressive generalized myositis, in particular, with lingual or orbital involvement.

Design, synthesis and DNA interactions of a chimera between a platinum complex and an IHF mimicking peptide.

PubMed

Rao, Harita; Damian, Mariana S; Alshiekh, Alak; Elmroth, Sofi K C; Diederichsen, Ulf

2015-12-28

Conjugation of metal complexes with peptide scaffolds possessing high DNA binding affinity has shown to modulate their biological activities and to enhance their interaction with DNA. In this work, a platinum complex/peptide chimera was synthesized based on a model of the Integration Host Factor (IHF), an architectural protein possessing sequence specific DNA binding and bending abilities through its interaction with a minor groove. The model peptide consists of a cyclic unit resembling the minor grove binding subdomain of IHF, a positively charged lysine dendrimer for electrostatic interactions with the DNA phosphate backbone and a flexible glycine linker tethering the two units. A norvaline derived artificial amino acid was designed to contain a dimethylethylenediamine as a bidentate platinum chelating unit, and introduced into the IHF mimicking peptides. The interaction of the chimeric peptides with various DNA sequences was studied by utilizing the following experiments: thermal melting studies, agarose gel electrophoresis for plasmid DNA unwinding experiments, and native and denaturing gel electrophoresis to visualize non-covalent and covalent peptide-DNA adducts, respectively. By incorporation of the platinum metal center within the model peptide mimicking IHF we have attempted to improve its specificity and DNA targeting ability, particularly towards those sequences containing adjacent guanine residues.

Selective inhibition of KCa3.1 channels mediates adenosine regulation of the motility of human T cells.

PubMed

Chimote, Ameet A; Hajdu, Peter; Kucher, Vladimir; Boiko, Nina; Kuras, Zerrin; Szilagyi, Orsolya; Yun, Yeo-Heung; Conforti, Laura

2013-12-15

Adenosine, a purine nucleoside, is present at high concentrations in tumors, where it contributes to the failure of immune cells to eliminate cancer cells. The mechanisms responsible for the immunosuppressive properties of adenosine are not fully understood. We tested the hypothesis that adenosine's immunosuppressive functions in human T lymphocytes are in part mediated via modulation of ion channels. The activity of T lymphocytes relies on ion channels. KCa3.1 and Kv1.3 channels control cytokine release and, together with TRPM7, regulate T cell motility. Adenosine selectively inhibited KCa3.1, but not Kv1.3 and TRPM7, in activated human T cells. This effect of adenosine was mainly mediated by A2A receptors, as KCa3.1 inhibition was reversed by SCH58261 (selective A2A receptor antagonist), but not by MRS1754 (A2B receptor antagonist), and it was mimicked by the A2A receptor agonist CGS21680. Furthermore, it was mediated by the cAMP/protein kinase A isoform (PKAI) signaling pathway, as adenylyl-cyclase and PKAI inhibition prevented adenosine effect on KCa3.1. The functional implication of the effect of adenosine on KCa3.1 was determined by measuring T cell motility on ICAM-1 surfaces. Adenosine and CGS21680 inhibited T cell migration. Comparable effects were obtained by KCa3.1 blockade with TRAM-34. Furthermore, the effect of adenosine on cell migration was abolished by pre-exposure to TRAM-34. Additionally, adenosine suppresses IL-2 secretion via KCa3.1 inhibition. Our data indicate that adenosine inhibits KCa3.1 in human T cells via A2A receptor and PKAI, thereby resulting in decreased T cell motility and cytokine release. This mechanism is likely to contribute to decreased immune surveillance in solid tumors.

Artificial Intelligence.

ERIC Educational Resources Information Center

Information Technology Quarterly, 1985

1985-01-01

This issue of "Information Technology Quarterly" is devoted to the theme of "Artificial Intelligence." It contains two major articles: (1) Artificial Intelligence and Law" (D. Peter O'Neill and George D. Wood); (2) "Artificial Intelligence: A Long and Winding Road" (John J. Simon, Jr.). In addition, it contains two sidebars: (1) "Calculating and…

Reticulated acanthoma with sebaceous differentiation mimicking melanoma

PubMed Central

Ribeiro, Felipe; Leocadia, Elizabeth; Macarenco, Ricardo S.; Lapins, Jan; Huet, Pascale; Akay, Bengu Nisa; Steiner, Denise

2017-01-01

Reticulated acanthoma with sebaceous differentiation (RASD) is a rare, benign cutaneous tumor with peculiar histopathologic characteristics [1]. RASD had been described under various synonyms such as superficial epithelioma with sebaceous differentiation, sebocrine adenoma, poroma with sebaceous differentiation, and seborrheic keratosis with sebaceous differentiation [2]. Clinical differential diagnosis of RASD includes cutaneous superficial epithelial neoplasia such as Bowen’s disease, superficial basal cell carcinoma (BCC) and intraepidermal eccrine poroma [1]. We report the first case of RASD mimicking both clinically and dermoscopically a melanoma. PMID:29085717

Heparin-Mimicking Polymers: Synthesis and Biological Applications

PubMed Central

2016-01-01

Heparin is a naturally occurring, highly sulfated polysaccharide that plays a critical role in a range of different biological processes. Therapeutically, it is mostly commonly used as an injectable solution as an anticoagulant for a variety of indications, although it has also been employed in other forms such as coatings on various biomedical devices. Due to the diverse functions of this polysaccharide in the body, including anticoagulation, tissue regeneration, anti-inflammation, and protein stabilization, and drawbacks of its use, analogous heparin-mimicking materials are also widely studied for therapeutic applications. This review focuses on one type of these materials, namely, synthetic heparin-mimicking polymers. Utilization of these polymers provides significant benefits compared to heparin, including enhancing therapeutic efficacy and reducing side effects as a result of fine-tuning heparin-binding motifs and other molecular characteristics. The major types of the various polymers are summarized, as well as their applications. Because development of a broader range of heparin-mimicking materials would further expand the impact of these polymers in the treatment of various diseases, future directions are also discussed. PMID:27739666

Heparin-Mimicking Polymers: Synthesis and Biological Applications.

PubMed

Paluck, Samantha J; Nguyen, Thi H; Maynard, Heather D

2016-11-14

Heparin is a naturally occurring, highly sulfated polysaccharide that plays a critical role in a range of different biological processes. Therapeutically, it is mostly commonly used as an injectable solution as an anticoagulant for a variety of indications, although it has also been employed in other forms such as coatings on various biomedical devices. Due to the diverse functions of this polysaccharide in the body, including anticoagulation, tissue regeneration, anti-inflammation, and protein stabilization, and drawbacks of its use, analogous heparin-mimicking materials are also widely studied for therapeutic applications. This review focuses on one type of these materials, namely, synthetic heparin-mimicking polymers. Utilization of these polymers provides significant benefits compared to heparin, including enhancing therapeutic efficacy and reducing side effects as a result of fine-tuning heparin-binding motifs and other molecular characteristics. The major types of the various polymers are summarized, as well as their applications. Because development of a broader range of heparin-mimicking materials would further expand the impact of these polymers in the treatment of various diseases, future directions are also discussed.

[Study on the growth, development and artificial propagation of Hypericum ascyron].

PubMed

Chen, Yu-mei; Zhang, Ke-qin; Song, Bai-jun; Zhao, Gui-ying; Wang, Zhen-hui; Wang, Li-mei; Chang, Wei-yi; Cong, Li-xin

2011-06-01

To explore the morphological changes, growth conditions and artificial propagation of Hypericum ascyron. The morphological changes were observed and recorded in the scene, the height and diameter of the plants were measured; the growth Verhaulst model was set up with the SPSS 17.0 software; the sexual reproduction and asexual reproduction were carried out in artificial cultivation. Hypericum ascyron started germinating in late April each year, branching in late May, flowering in late June, the period of full bearing was in early August, seeds were mature in early October. The Verhaulst models of the increase in the height (H), the quantity of leaf pairs (L) and the branching (B) were, H = 127.109/(1 + 23.744 x e(-0.062t)), L = 23.343/(1 + 11.303 x e(-0.062t)), B = 22.037/(1 + 73.068 x e(-0.068t)). The survival rate of whole graft and segmentation plant were 100% and 67.2% respectively on asexual reproduction; on the sexual reproduction, the seed germination rate was 15.2%, the survival rate of transplant seedlings was 36%. The period of growth and development of Hypericum ascyron is from April to October and it can be carried out artificial propagation.

Artificial 64-Residue HIV-1 Enhancer-Binding Peptide Is a Potent Inhibitor of Viral Replication in HIV-1-Infected Cells.

PubMed

Oufir, Mouhssin; Bisset, Leslie R; Hoffmann, Stefan R K; Xue, Gongda; Klauser, Stephan; Bergamaschi, Bianca; Gervaix, Alain; Böni, Jürg; Schüpbach, Jörg; Gutte, Bernd

2011-01-01

An artificial HIV-1 enhancer-binding peptide was extended by nine consecutive arginine residues at the C-terminus and by the nuclear localization signal of SV40 large T antigen at the N-terminus. The resulting synthetic 64-residue peptide was found to bind to the two enhancers of the HIV-1 long terminal repeat, cross the plasma membrane and the nuclear envelope of human cells, and suppress the HIV-1 enhancer-controlled expression of a green fluorescent protein reporter gene. Moreover, HIV-1 replication is inhibited by this peptide in HIV-1-infected CEM-GFP cells as revealed by HIV-1 p24 ELISA and real-time RT-PCR of HIV-1 RNA. Rapid uptake of this intracellular stable and inhibitory peptide into the cells implies that this peptide may have the potential to attenuate HIV-1 replication in vivo.

Artificial 64-Residue HIV-1 Enhancer-Binding Peptide Is a Potent Inhibitor of Viral Replication in HIV-1-Infected Cells

PubMed Central

Oufir, Mouhssin; Bisset, Leslie R.; Hoffmann, Stefan R. K.; Xue, Gongda; Klauser, Stephan; Bergamaschi, Bianca; Gervaix, Alain; Böni, Jürg; Schüpbach, Jörg; Gutte, Bernd

2011-01-01

An artificial HIV-1 enhancer-binding peptide was extended by nine consecutive arginine residues at the C-terminus and by the nuclear localization signal of SV40 large T antigen at the N-terminus. The resulting synthetic 64-residue peptide was found to bind to the two enhancers of the HIV-1 long terminal repeat, cross the plasma membrane and the nuclear envelope of human cells, and suppress the HIV-1 enhancer-controlled expression of a green fluorescent protein reporter gene. Moreover, HIV-1 replication is inhibited by this peptide in HIV-1-infected CEM-GFP cells as revealed by HIV-1 p24 ELISA and real-time RT-PCR of HIV-1 RNA. Rapid uptake of this intracellular stable and inhibitory peptide into the cells implies that this peptide may have the potential to attenuate HIV-1 replication in vivo. PMID:22312334

Understanding Financial Market States Using an Artificial Double Auction Market

PubMed Central

2016-01-01

The ultimate value of theories describing the fundamental mechanisms behind asset prices in financial systems is reflected in the capacity of such theories to understand these systems. Although the models that explain the various states of financial markets offer substantial evidence from the fields of finance, mathematics, and even physics, previous theories that attempt to address the complexities of financial markets in full have been inadequate. We propose an artificial double auction market as an agent-based model to study the origin of complex states in financial markets by characterizing important parameters with an investment strategy that can cover the dynamics of the financial market. The investment strategies of chartist traders in response to new market information should reduce market stability based on the price fluctuations of risky assets. However, fundamentalist traders strategically submit orders based on fundamental value and, thereby stabilize the market. We construct a continuous double auction market and find that the market is controlled by the proportion of chartists, Pc. We show that mimicking the real state of financial markets, which emerges in real financial systems, is given within the range Pc = 0.40 to Pc = 0.85; however, we show that mimicking the efficient market hypothesis state can be generated with values less than Pc = 0.40. In particular, we observe that mimicking a market collapse state is created with values greater than Pc = 0.85, at which point a liquidity shortage occurs, and the phase transition behavior is described at Pc = 0.85. PMID:27031110

Understanding Financial Market States Using an Artificial Double Auction Market.

PubMed

Yim, Kyubin; Oh, Gabjin; Kim, Seunghwan

2016-01-01

The ultimate value of theories describing the fundamental mechanisms behind asset prices in financial systems is reflected in the capacity of such theories to understand these systems. Although the models that explain the various states of financial markets offer substantial evidence from the fields of finance, mathematics, and even physics, previous theories that attempt to address the complexities of financial markets in full have been inadequate. We propose an artificial double auction market as an agent-based model to study the origin of complex states in financial markets by characterizing important parameters with an investment strategy that can cover the dynamics of the financial market. The investment strategies of chartist traders in response to new market information should reduce market stability based on the price fluctuations of risky assets. However, fundamentalist traders strategically submit orders based on fundamental value and, thereby stabilize the market. We construct a continuous double auction market and find that the market is controlled by the proportion of chartists, Pc. We show that mimicking the real state of financial markets, which emerges in real financial systems, is given within the range Pc = 0.40 to Pc = 0.85; however, we show that mimicking the efficient market hypothesis state can be generated with values less than Pc = 0.40. In particular, we observe that mimicking a market collapse state is created with values greater than Pc = 0.85, at which point a liquidity shortage occurs, and the phase transition behavior is described at Pc = 0.85.

Detection and volume estimation of artificial hematomas in the subcutaneous fatty tissue: comparison of different MR sequences at 3.0 T.

PubMed

Ogris, Kathrin; Petrovic, Andreas; Scheicher, Sylvia; Sprenger, Hanna; Urschler, Martin; Hassler, Eva Maria; Yen, Kathrin; Scheurer, Eva

2017-06-01

In legal medicine, reliable localization and analysis of hematomas in subcutaneous fatty tissue is required for forensic reconstruction. Due to the absence of ionizing radiation, magnetic resonance imaging (MRI) is particularly suited to examining living persons with forensically relevant injuries. However, there is limited experience regarding MRI signal properties of hemorrhage in soft tissue. The aim of this study was to evaluate MR sequences with respect to their ability to show high contrast between hematomas and subcutaneous fatty tissue as well as to reliably determine the volume of artificial hematomas. Porcine tissue models were prepared by injecting blood into the subcutaneous fatty tissue to create artificial hematomas. MR images were acquired at 3T and four blinded observers conducted manual segmentation of the hematomas. To assess segmentability, the agreement of measured volume with the known volume of injected blood was statistically analyzed. A physically motivated normalization taking into account partial volume effect was applied to the data to ensure comparable results among differently sized hematomas. The inversion recovery sequence exhibited the best segmentability rate, whereas the T1T2w turbo spin echo sequence showed the most accurate results regarding volume estimation. Both sequences led to reproducible volume estimations. This study demonstrates that MRI is a promising forensic tool to assess and visualize even very small amounts of blood in soft tissue. The presented results enable the improvement of protocols for detection and volume determination of hemorrhage in forensically relevant cases and also provide fundamental knowledge for future in-vivo examinations.

Calvarial sarcoid mimicking metastatic disease.

PubMed

Bodie, B F; Kheir, S M; Omura, E F

1980-10-01

A 61-year-old white woman presented with localized cutaneous Boeck's sarcoid and multiple lytic skull lesions mimicking metastatic carcinoma. Complete workup revealed no neoplastic process; biopsy of the skull lesions showed noncaseating granulomas consistent with sarcoid. Although rare, calvarial sarcoid can occur.

Clear cell carcinoma of the ovary mimicking struma ovarii and carcinoid tumor.

PubMed

Alduaij, Ahmad; Quddus, M Ruhul

2011-04-01

Clear cell carcinomas are considered as high-grade tumor often with poor prognosis. We describe 2 cases of clear cell carcinomas of the ovary mimicking benign or less aggressive tumors encountered in the female genital track. The first case is mimicking a benign monodermal teratoma, the so-called struma ovarii, and the second mimicking a carcinoid tumor. Copyright © 2011 Elsevier Inc. All rights reserved.

Non-harmful insertion of data mimicking computer network attacks

DOE Office of Scientific and Technical Information (OSTI.GOV)

Neil, Joshua Charles; Kent, Alexander; Hash, Jr, Curtis Lee

Non-harmful data mimicking computer network attacks may be inserted in a computer network. Anomalous real network connections may be generated between a plurality of computing systems in the network. Data mimicking an attack may also be generated. The generated data may be transmitted between the plurality of computing systems using the real network connections and measured to determine whether an attack is detected.

Mimicking the Moon

NASA Image and Video Library

2014-11-03

When Galileo first observed Venus displaying a crescent phase, he excitedly wrote to Kepler (in anagram) of Venus mimicking the moon-goddess. He would have been delirious with joy to see Saturn and Titan, seen in this image, doing the same thing. More than just pretty pictures, high-phase observations -- taken looking generally toward the Sun, as in this image -- are very powerful scientifically since the way atmospheres and rings transmit sunlight is often diagnostic of compositions and physical states. In this example, Titan's crescent nearly encircles its disk due to the small haze particles high in its atmosphere refracting the incoming light of the distant Sun. This view looks toward the sunlit side of the rings from about 3 degrees above the ringplane. The image was taken in violet light with the Cassini spacecraft wide-angle camera on Aug. 11, 2013. The view was obtained at a distance of approximately 1.1 million miles (1.7 million kilometers) from Saturn and at a Sun-Saturn-spacecraft, or phase, angle of 154 degrees. Image scale is 64 miles (103 kilometers) per pixel. http://photojournal.jpl.nasa.gov/catalog/PIA18291

Sweet taste receptor expression in ruminant intestine and its activation by artificial sweeteners to regulate glucose absorption.

PubMed

Moran, A W; Al-Rammahi, M; Zhang, C; Bravo, D; Calsamiglia, S; Shirazi-Beechey, S P

2014-01-01

Absorption of glucose from the lumen of the intestine into enterocytes is accomplished by sodium-glucose co-transporter 1 (SGLT1). In the majority of mammalian species, expression (this includes activity) of SGLT1 is upregulated in response to increased dietary monosaccharides. This regulatory pathway is initiated by sensing of luminal sugar by the gut-expressed sweet taste receptor. The objectives of our studies were to determine (1) if the ruminant intestine expresses the sweet taste receptor, which consists of two subunits [taste 1 receptor 2 (T1R2) and 3 (T1R3)], and other key signaling molecules required for SGLT1 upregulation in nonruminant intestines, and (2) whether T1R2-T1R3 sensing of artificial sweeteners induces release of glucagon-like peptide-2 (GLP-2) and enhances SGLT1 expression. We found that the small intestine of sheep and cattle express T1R2, T1R3, G-protein gustducin, and GLP-2 in enteroendocrine L-cells. Maintaining 110-d-old ruminating calves for 60d on a diet containing a starter concentrate and the artificial sweetener Sucram (consisting of saccharin and neohesperidin dihydrochalcone; Pancosma SA, Geneva, Switzerland) enhances (1) Na(+)-dependent d-glucose uptake by over 3-fold, (2) villus height and crypt depth by 1.4- and 1.2-fold, and (3) maltase- and alkaline phosphatase-specific activity by 1.5-fold compared to calves maintained on the same diet without Sucram. No statistically significant differences were observed for rates of intestinal glucose uptake, villus height, crypt depth, or enzyme activities between 50-d-old milk-fed calves and calves maintained on the same diet containing Sucram. When adult cows were kept on a diet containing 80:20 ryegrass hay-to-concentrate supplemented with Sucram, more than a 7-fold increase in SGLT1 protein abundance was noted. Collectively, the data indicate that inclusion of this artificial sweetener enhances SGLT1 expression and mucosal growth in ruminant animals. Exposure of ruminant sheep

Effect of Light-Activated Tooth Whitening on Color Change Relative to Color of Artificially Stained Teeth.

PubMed

Kwon, So Ran; Kurti, Steven R; Oyoyo, Udochukwu; Li, Yiming

2015-01-01

There is still controversy as to the efficacy of light activation used in tooth whitening. The purpose of this study was to evaluate the effect of light activation on tooth color change relative to the artificial dye color. Extracted human third molars (160) were randomly distributed into eight groups of 20 specimens each based on artificial staining and use of light activation. All groups received three 45-minute sessions of in-office whitening at 3-day intervals. Color measurements were performed with an intraoral spectrophotometer at baseline prior to staining (T0), after artificial staining (T1), 1-day--(T2), and 1-week--(T3) post-whitening. Color differences were calculated relative to after artificial staining color parameters (L*1, a*1, b*1) with the use of a software analysis program enabling synchronization of two images. Within the same staining groups, the light-activated samples exhibited a greater color change than their nonlight-activated counterparts. However, only in the case of the yellow-stained samples at 1-day post-whitening was there a significant difference between the nonlight-activated and light-activated groups (Tukey's post hoc multiple comparison test for pairwise comparisons, p < 0.05). Light activation is a valid method for enhancing the efficacy of tooth whitening with respect to overall color change and works best with yellow stains. Light activation is a valid method for enhancing the efficacy of tooth whitening with respect to overall color change and works best with yellow stains.

Chronic Consumption of Artificial Sweetener in Packets or Tablets and Type 2 Diabetes Risk: Evidence from the E3N-European Prospective Investigation into Cancer and Nutrition Study.

PubMed

Fagherazzi, Guy; Gusto, Gaëlle; Affret, Aurélie; Mancini, Francesca Romana; Dow, Courtney; Balkau, Beverley; Clavel-Chapelon, Françoise; Bonnet, Fabrice; Boutron-Ruault, Marie-Christine

2017-01-01

The influence of artificial sweeteners on metabolic diseases is controversial. Artificially sweetened beverages have been associated with an increased risk of type 2 diabetes (T2D) but biases and reverse causation have been suspected to have influenced the observed association. In addition, it has been suggested that investigation into the relationship between the frequency and duration of the consumption of packet or tablet artificial sweeteners and T2D risk is necessary. We used data from 61,440 women in the prospective E3N-European Prospective Investigation into Cancer and Nutrition study, conducted between 1993 and 2011. We estimated hazards ratios (HRs) and 95% CIs of T2D risk associated with both the frequency and the duration of use of artificial sweeteners consumed in packets or tablets. Compared to "never or rare" consumers of artificial sweeteners, those using them "always or almost always" had an increased risk of T2D (HR = 1.83 [95% CI 1.66-2.02] in the multivariate model [MM], HR = 1.33 [95% CI 1.20-1.47] when further adjusted for body mass index, BMI). Women consuming artificial sweeteners in packets or tablets for more than 10 years also had an increased risk of T2D compared to never or rare users (HR = 2.10 [95% CI 1.83-2.40] in the MM and HR = 1.15 [95% CI 1.00-1.33] when adjusted for BMI, respectively). Our data suggest that both a higher frequency and a longer consumption of artificial sweeteners in packets or tablets was associated with T2D risk, independently of major T2D risk factors, but partially mediated by adiposity. A precautionary principle should be applied to the promotion of these products that are still largely recommended as healthy sugar substitutes. © 2017 S. Karger AG, Basel.

Universal Artificial Antigen Presenting Cells to Selectively Propagate T Cells Expressing Chimeric Antigen Receptor Independent of Specificity

PubMed Central

Rushworth, David; Jena, Bipulendu; Olivares, Simon; Maiti, Sourindra; Briggs, Neima; Somanchi, Srinivas; Dai, Jianliang; Lee, Dean; Cooper, Laurence J. N.

2014-01-01

T cells genetically modified to stably express immunoreceptors are being assessed for therapeutic potential in clinical trials. T cells expressing a chimeric antigen receptor (CAR) are endowed with a new specificity to target tumor-associated antigen (TAA) independent of major histocompatibility complex. Our approach to non-viral gene transfer in T cells uses ex vivo numeric expansion of CAR+ T cells on irradiated artificial antigen presenting cells (aAPC) bearing the targeted TAA. The requirement for aAPC to express a desired TAA limits the human application of CARs with multiple specificities when selective expansion through co-culture with feeder cells is sought. As an alternative to expressing individual TAAs on aAPC, we expressed one ligand that could activate CAR+ T cells for sustained proliferation independent of specificity. We expressed a CAR ligand (designated CARL) that binds the conserved IgG4 extracellular domain of CAR and demonstrated CARL+ aAPC propagate CAR+ T cells of multiple specificities. CARL avoids technical issues and costs associated with deploying clinical-grade aAPC for each TAA targeted by a given CAR. Employing CARL enables one aAPC to numerically expand all CAR+ T cells containing the IgG4 domain, and simplifies expansion, testing, and clinical translation of CAR+ T cells of any specificity. PMID:24714354

Conformational analysis of a synthetic fish kisspeptin 1 peptide in membrane mimicking environments

PubMed Central

Shahi, Neetu; Singh, Atul Kumar; Khangembam, Victoria Chanu; Singh, Arvind Kumar; Kumar, Satish

2017-01-01

Kisspeptin 1 is a neuropeptide hormone of the RFamide family, which act as an upstream regulator of brain-pituitary-gonad (BPG) axis in most vertebrates including teleosts. In the present study, a 16 amino acid long putative mature bioactive peptide (kiss 1) from preprokisspeptin 1 of golden mahseer, Tor putitora (Hamilton, 1822), was synthesized and characterized using an integrated (experimental and in silico) approach. The far-UV circular dichroism (CD) spectrum of this peptide was evaluated both in aqueous and membrane mimicking solvents (TFE, HFIP and Dioxane). The results indicate that kiss 1 peptide adopted helical, turn and β conformations in membrane like environments. The near-UV CD spectroscopy was also carried out to examine the tertiary packing around aromatic residues of kiss 1 peptide and the peptide-membrane complex. The kiss 1 peptide exhibited little signal in water, but a prominent negative band was observed at around 275 nm when membrane mimetic solution was added. The observed ordered conformations of kiss 1 peptide in the different solvents indicated its potential biological activity which could enhance the secretion of gonadotropin-releasing hormone (GnRH) at BPG axis. The conformational information generated from the present study reinforces the application prospects of bioactive synthetic peptide analogs of kisspeptin 1 in improving the reproductive performances of important cultivable fish species. PMID:28977030

Viruses, Artificial Viruses and Virus-Based Structures for Biomedical Applications.

PubMed

van Rijn, Patrick; Schirhagl, Romana

2016-06-01

Nanobiomaterials such as virus particles and artificial virus particles offer tremendous opportunities to develop new biomedical applications such as drug- or gene-delivery, imaging and sensing but also improve understanding of biological mechanisms. Recent advances within the field of virus-based systems give insights in how to mimic viral structures and virus assembly processes as well as understanding biodistribution, cell/tissue targeting, controlled and triggered disassembly or release and circulation times. All these factors are of high importance for virus-based functional systems. This review illustrates advances in mimicking and enhancing or controlling these aspects to a high degree toward delivery and imaging applications. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Primary Papillary Mucinous Adenocarcinoma of the Ureter Mimicking Genitourinary Tuberculosis

PubMed Central

Gulwani, Hanni; Jain, Aruna

2010-01-01

Primary adenocarcinomas of the renal pelvis and ureter are rare and account for less than 1% of all malignancies at this site. We report a case of primary papillary mucinous adenocarcinoma of the ureter that clinically mimicked genitourinary tuberculosis. Early diagnosis is important for the better outcome. PMID:21151719

Enzyme-mimicking polymer brush-functionalized surface for combating biomaterial-associated infections

NASA Astrophysics Data System (ADS)

Jiang, Rujian; Xin, Zhirong; Xu, Shiai; Shi, Hengchong; Yang, Huawei; Song, Lingjie; Yan, Shunjie; Luan, Shifang; Yin, Jinghua; Khan, Ather Farooq; Li, Yonggang

2017-11-01

Biomaterial-associated infections critically compromise the functionality and performance of the medical devices, and pose a serious threat to human healthcare. Recently, natural DNase enzyme has been recognized as a potent material to prevent bacterial adhesion and biofilm formation. However, the vulnerability of DNase dramatically limits its long-term performance in antibacterial applications. In this work, DNase-mimicking polymer brushes were constructed to mimic the DNA-cleavage activity as well as the macromolecular scaffold of the natural DNase. The bacteria repellent efficacy of DNase-mimicking polymer brush-functionalized surface was comparable to that of the DNase-functionalized surface. More importantly, due to their inherent stability, DNase-mimicking polymer brushes presented the much better performance in inhibiting bacterial biofilm development for prolonged periods of time, as compared to the natural DNase. The as-developed DNase-mimicking polymer brush-functionalized surface presents a promising approach to combat biomaterial-associated infections.

Comparative differences between T1a/b and T1e/m as substages in T1 urothelial carcinoma of the bladder.

PubMed

Turan, Turgay; Efiloğlu, Özgür; Günaydin, Bilal; Özkanli, Şeyma; Nikerel, Emrah; Atiş, Gökhan; Çaşkurlu, Turhan; Yildirim, Asif

2018-01-01

To evaluate the prognostic value of the depth of lamina propria invasion in patients with T1 bladder cancer and to display comparative differences between the T1a/b and T1e/m substaging systems. This study included 106 patients with primary stage T1 urothelial bladder tumours who underwent surgery between January 2009 and December 2014. Pathologic specimens were re-evaluated to confirm the diagnosis of T1 and substaging by the same pathologist using two systems: T1a and T1b, and T1m and T1e. Age, tumour size, multiplicity, associated carcinoma in situ, tumour grade, and T1 substaging system were investigated to detect the relation between disease progression and recurrence. The recurrence rate was 52% for T1a (n=42) vs. 76% for T1b (n=20) (p=0.028) and 55% for T1m (n=32) vs. 62% for T1e (n=30), respectively (p=0.446). There was no significant difference between the substaging groups for disease progression: T1a (n=12, 15%) vs. T1b (n=7, 27%), and T1m (n=8, 13.8%) vs. T1e (n=11, 23%) (p>0.05). In the multivariate analysis, tumour size >3 cm (p=0.008), multiplicity (p=0.049), and substaging T1b (p=0.043) were independent predictive factors for tumour recurrence. According to the Kaplan-Meier actuarial method, recurrence-free survival was significantly different in patients with pT1a tumours compared with those with pT1b tumours (p=0.033). Substaging T1 provides a prediction of disease recurrence. Regarding recurrence, T1a/b substaging can provide better knowledge of disease behaviour because it is predicted as more superior than T1 m/e, and it can help in determining the requirement for early cystectomy. Copyright® by the International Brazilian Journal of Urology.

Aspartame downregulates 3T3-L1 differentiation.

PubMed

Pandurangan, Muthuraman; Park, Jeongeun; Kim, Eunjung

2014-10-01

Aspartame is an artificial sweetener used as an alternate for sugar in several foods and beverages. Since aspartame is 200 times sweeter than traditional sugar, it can give the same level of sweetness with less substance, which leads to lower-calorie food intake. There are reports that consumption of aspartame-containing products can help obese people lose weight. However, the potential role of aspartame in obesity is not clear. The present study investigated whether aspartame suppresses 3T3-L1 differentiation, by downregulating phosphorylated peroxisome proliferator-activated receptor γ (p-PPARγ), peroxisome proliferator-activated receptor γ (PPARγ), fatty acid-binding protein 4 (FABP4), CCAAT/enhancer-binding protein α (C/EBPα), and sterol regulatory element-binding protein 1 (SREBP1), which are critical for adipogenesis. The 3T3-L1 adipocytes were cultured and differentiated for 6 d in the absence and presence of 10 μg/ml of aspartame. Aspartame reduced lipid accumulation in differentiated adipocytes as evidenced by Oil Red O staining. qRT-PCR analysis showed that the PPARγ, FABP4, and C/EBPα mRNA expression was significantly reduced in the aspartame-treated adipocytes. Western blot analysis showed that the induction of p-PPARγ, PPARγ, SREBP1, and adipsin was markedly reduced in the aspartame-treated adipocytes. Taken together, these data suggest that aspartame may be a potent substance to alter adipocyte differentiation and control obesity.

Umbilical cord blood regulatory T-cell expansion and functional effects of tumor necrosis factor receptor family members OX40 and 4-1BB expressed on artificial antigen-presenting cells

PubMed Central

Harker-Murray, Paul; Porter, Stephen B.; Merkel, Sarah C.; Londer, Aryel; Taylor, Dawn K.; Bina, Megan; Panoskaltsis-Mortari, Angela; Rubinstein, Pablo; Van Rooijen, Nico; Golovina, Tatiana N.; Suhoski, Megan M.; Miller, Jeffrey S.; Wagner, John E.; June, Carl H.; Riley, James L.

2008-01-01

Previously, we showed that human umbilical cord blood (UCB) regulatory T cells (Tregs) could be expanded approximately 100-fold using anti-CD3/28 monoclonal antibody (mAb)–coated beads to provide T-cell receptor and costimulatory signals. Because Treg numbers from a single UCB unit are limited, we explored the use of cell-based artificial antigen-presenting cells (aAPCs) preloaded with anti-CD3/28 mAbs to achieve higher levels of Treg expansion. Compared with beads, aAPCs had similar expansion properties while significantly increasing transforming growth factor β (TGF-β) secretion and the potency of Treg suppressor function. aAPCs modified to coexpress OX40L or 4-1BBL expanded UCB Tregs to a significantly greater extent than bead- or nonmodified aAPC cultures, reaching mean expansion levels exceeding 1250-fold. Despite the high expansion and in contrast to studies using other Treg sources, neither OX40 nor 4-1BB signaling of UCB Tregs reduced in vitro suppression. UCB Tregs expanded with 4-1BBL expressing aAPCs had decreased levels of proapoptotic bim. UCB Tregs expanded with nonmodified or modified aAPCs versus beads resulted in higher survival associated with increased Treg persistence in a xeno-geneic graft-versus-host disease lethality model. These data offer a novel approach for UCB Treg expansion using aAPCs, including those coexpressing OX40L or 4-1BBL. PMID:18645038

Systematized water content calculation in cartilage using T1-mapping MR estimations: design and validation of a mathematical model.

PubMed

Shiguetomi-Medina, J M; Ramirez-Gl, J L; Stødkilde-Jørgensen, H; Møller-Madsen, B

2017-09-01

Up to 80 % of cartilage is water; the rest is collagen fibers and proteoglycans. Magnetic resonance (MR) T1-weighted measurements can be employed to calculate the water content of a tissue using T1 mapping. In this study, a method that translates T1 values into water content data was tested statistically. To develop a predictive equation, T1 values were obtained for tissue-mimicking gelatin samples. 1.5 T MRI was performed using inverse angle phase and an inverse sequence at 37 (±0.5) °C. Regions of interest were manually delineated and the mean T1 value was estimated in arbitrary units. Data were collected and modeled using linear regression. To validate the method, articular cartilage from six healthy pigs was used. The experiment was conducted in accordance with the Danish Animal Experiment Committee. Double measurements were performed for each animal. Ex vivo, all water in the tissue was extracted by lyophilization, thus allowing the volume of water to be measured. This was then compared with the predicted water content via Lin's concordance correlation coefficient at the 95 % confidence level. The mathematical model was highly significant when compared to a null model (p < 0.0001). 97.3 % of the variation in water content can be explained by absolute T1 values. Percentage water content could be predicted as 0.476 + (T1 value) × 0.000193 × 100 %. We found that there was 98 % concordance between the actual and predicted water contents. The results of this study demonstrate that MR data can be used to predict percentage water contents of cartilage samples. 3 (case-control study).

Abdominal Wall Endometriosis Mimicking Metastases.

PubMed

Nambiar, Rakul; Anoop, T M; Mony, Rari P

2018-06-01

Abdominal wall lesions can be broadly divided into nontumorous and tumorous conditions. Nontumorous lesions include congenital lesion, abdominal wall hernia, inflammation and infection, vascular lesions, and miscellaneous conditions like hematoma. Tumorous lesions include benign and malignant neoplasms. Here, we report an unusual case of abdominal wall endometriosis mimicking metastases in a patient with breast carcinoma.

Inorganic nanoparticle-based T1 and T1/T2 magnetic resonance contrast probes

NASA Astrophysics Data System (ADS)

Hu, Fengqin; Zhao, Yong Sheng

2012-09-01

Magnetic resonance imaging (MRI) yields high spatially resolved contrast with anatomical details for diagnosis, deeper penetration depth and rapid 3D scanning. To improve imaging sensitivity, adding contrast agents accelerates the relaxation rate of water molecules, thereby greatly increasing the contrast between specific issues or organs of interest. Currently, the majority of T1 contrast agents are paramagnetic molecular complexes, typically Gd(iii) chelates. Various nanoparticulate T1 and T1/T2 contrast agents have recently been investigated as novel agents possessing the advantages of both the T1 contrast effect and nanostructural characteristics. In this minireview, we describe the recent progress of these inorganic nanoparticle-based MRI contrast agents. Specifically, we mainly report on Gd and Mn-based inorganic nanoparticles and ultrasmall iron oxide/ferrite nanoparticles.

Protein-mimicking nanowire-inspired electro-catalytic biosensor for probing acetylcholinesterase activity and its inhibitors.

PubMed

Zhang, Qingqing; Hu, Yufang; Wu, Di; Ma, Shaohua; Wang, Jiao; Rao, Jiajia; Xu, Lihua; Xu, Huan; Shao, Huili; Guo, Zhiyong; Wang, Sui

2018-06-01

A highly sensitive electrochemical biosensor based on the synthetized L-Cysteine-Ag(I) coordination polymer (L-Cys-Ag(I) CP), which looks like a protein-mimicking nanowire, was constructed to detect acetylcholinesterase (AChE) activity and screen its inhibitors. This sensing strategy involves the reaction of acetylcholine chloride (ACh) with acetylcholinesterase (AChE) to form choline that is in turn catalytically oxidized by choline oxidase (ChOx) to produce hydrogen peroxide (H 2 O 2 ), thus L-Cys-Ag(I) CP possesses the electro-catalytic property to H 2 O 2 reduction. Herein, the protein-mimicking nanowire-based platform was capable of investigating successive of H 2 O 2 effectively by amperometric i-t (current-time) response, and was further applied for the turn-on electrochemical detection of AChE activity. The proposed sensor is highly sensitive (limit of detection is 0.0006 U/L) and is feasible for screening inhibitors of AChE. The model for AChE inhibition was further established and two traditional AChE inhibitors (donepezil and tacrine) were employed to verify the feasibility of the system. The IC 5 0 of donepezil and tacrine were estimated to be 1.4 nM and 3.5 nM, respectively. The developed protocol provides a new and promising platform for probing AChE activity and screening its inhibitors with low cost, high sensitivity and selectivity. Copyright © 2018 Elsevier B.V. All rights reserved.

The Effects of Hsp90α1 Mutations on Myosin Thick Filament Organization.

PubMed

He, Qiuxia; Liu, Kechun; Tian, Zhenjun; Du, Shao Jun

2015-01-01

Heat shock protein 90α plays a key role in myosin folding and thick filament assembly in muscle cells. To assess the structure and function of Hsp90α and its potential regulation by post-translational modification, we developed a combined knockdown and rescue assay in zebrafish embryos to systematically analyze the effects of various mutations on Hsp90α function in myosin thick filament organization. DNA constructs expressing the Hsp90α1 mutants with altered putative ATP binding, phosphorylation, acetylation or methylation sites were co-injected with Hsp90α1 specific morpholino into zebrafish embryos. Myosin thick filament organization was analyzed in skeletal muscles of the injected embryos by immunostaining. The results showed that mutating the conserved D90 residue in the Hsp90α1 ATP binding domain abolished its function in thick filament organization. In addition, phosphorylation mimicking mutations of T33D, T33E and T87E compromised Hsp90α1 function in myosin thick filament organization. Similarly, K287Q acetylation mimicking mutation repressed Hsp90α1 function in myosin thick filament organization. In contrast, K206R and K608R hypomethylation mimicking mutations had not effect on Hsp90α1 function in thick filament organization. Given that T33 and T87 are highly conserved residues involved post-translational modification (PTM) in yeast, mouse and human Hsp90 proteins, data from this study could indicate that Hsp90α1 function in myosin thick filament organization is potentially regulated by PTMs involving phosphorylation and acetylation.

The Effects of Hsp90α1 Mutations on Myosin Thick Filament Organization

PubMed Central

He, Qiuxia; Liu, Kechun; Tian, Zhenjun; Du, Shao Jun

2015-01-01

Heat shock protein 90α plays a key role in myosin folding and thick filament assembly in muscle cells. To assess the structure and function of Hsp90α and its potential regulation by post-translational modification, we developed a combined knockdown and rescue assay in zebrafish embryos to systematically analyze the effects of various mutations on Hsp90α function in myosin thick filament organization. DNA constructs expressing the Hsp90α1 mutants with altered putative ATP binding, phosphorylation, acetylation or methylation sites were co-injected with Hsp90α1 specific morpholino into zebrafish embryos. Myosin thick filament organization was analyzed in skeletal muscles of the injected embryos by immunostaining. The results showed that mutating the conserved D90 residue in the Hsp90α1 ATP binding domain abolished its function in thick filament organization. In addition, phosphorylation mimicking mutations of T33D, T33E and T87E compromised Hsp90α1 function in myosin thick filament organization. Similarly, K287Q acetylation mimicking mutation repressed Hsp90α1 function in myosin thick filament organization. In contrast, K206R and K608R hypomethylation mimicking mutations had not effect on Hsp90α1 function in thick filament organization. Given that T33 and T87 are highly conserved residues involved post-translational modification (PTM) in yeast, mouse and human Hsp90 proteins, data from this study could indicate that Hsp90α1 function in myosin thick filament organization is potentially regulated by PTMs involving phosphorylation and acetylation. PMID:26562659

Artificial pancreas treatment for outpatients with type 1 diabetes: systematic review and meta-analysis.

PubMed

Bekiari, Eleni; Kitsios, Konstantinos; Thabit, Hood; Tauschmann, Martin; Athanasiadou, Eleni; Karagiannis, Thomas; Haidich, Anna-Bettina; Hovorka, Roman; Tsapas, Apostolos

2018-04-18

To evaluate the efficacy and safety of artificial pancreas treatment in non-pregnant outpatients with type 1 diabetes. Systematic review and meta-analysis of randomised controlled trials. Medline, Embase, Cochrane Library, and grey literature up to 2 February 2018. Randomised controlled trials in non-pregnant outpatients with type 1 diabetes that compared the use of any artificial pancreas system with any type of insulin based treatment. Primary outcome was proportion (%) of time that sensor glucose level was within the near normoglycaemic range (3.9-10 mmol/L). Secondary outcomes included proportion (%) of time that sensor glucose level was above 10 mmol/L or below 3.9 mmol/L, low blood glucose index overnight, mean sensor glucose level, total daily insulin needs, and glycated haemoglobin. The Cochrane Collaboration risk of bias tool was used to assess study quality. 40 studies (1027 participants with data for 44 comparisons) were included in the meta-analysis. 35 comparisons assessed a single hormone artificial pancreas system, whereas nine comparisons assessed a dual hormone system. Only nine studies were at low risk of bias. Proportion of time in the near normoglycaemic range (3.9-10.0 mmol/L) was significantly higher with artificial pancreas use, both overnight (weighted mean difference 15.15%, 95% confidence interval 12.21% to 18.09%) and over a 24 hour period (9.62%, 7.54% to 11.7%). Artificial pancreas systems had a favourable effect on the proportion of time with sensor glucose level above 10 mmol/L (-8.52%, -11.14% to -5.9%) or below 3.9 mmol/L (-1.49%, -1.86% to -1.11%) over 24 hours, compared with control treatment. Robustness of findings for the primary outcome was verified in sensitivity analyses, by including only trials at low risk of bias (11.64%, 9.1% to 14.18%) or trials under unsupervised, normal living conditions (10.42%, 8.63% to 12.2%). Results were consistent in a subgroup analysis both for single hormone and dual hormone artificial pancreas

Biosynthesis of Essential Polyunsaturated Fatty Acids in Wheat Triggered by Expression of Artificial Gene

PubMed Central

Mihálik, Daniel; Klčová, Lenka; Ondreičková, Katarína; Hudcovicová, Martina; Gubišová, Marcela; Klempová, Tatiana; Čertík, Milan; Pauk, János; Kraic, Ján

2015-01-01

The artificial gene D6D encoding the enzyme ∆6desaturase was designed and synthesized using the sequence of the same gene from the fungus Thamnidium elegans. The original start codon was replaced by the signal sequence derived from the wheat gene for high-molecular-weight glutenin subunit and the codon usage was completely changed for optimal expression in wheat. Synthesized artificial D6D gene was delivered into plants of the spring wheat line CY-45 and the gene itself, as well as transcribed D6D mRNA were confirmed in plants of T0 and T1 generations. The desired product of the wheat genetic modification by artificial D6D gene was the γ-linolenic acid. Its presence was confirmed in mature grains of transgenic wheat plants in the amount 0.04%–0.32% (v/v) of the total amount of fatty acids. Both newly synthesized γ-linolenic acid and stearidonic acid have been detected also in leaves, stems, roots, awns, paleas, rachillas, and immature grains of the T1 generation as well as in immature and mature grains of the T2 generation. Contents of γ-linolenic acid and stearidonic acid varied in range 0%–1.40% (v/v) and 0%–1.53% (v/v) from the total amount of fatty acids, respectively. This approach has opened the pathway of desaturation of fatty acids and production of essential polyunsaturated fatty acids in wheat. PMID:26694368

A Soft Total Artificial Heart-First Concept Evaluation on a Hybrid Mock Circulation.

PubMed

Cohrs, Nicholas H; Petrou, Anastasios; Loepfe, Michael; Yliruka, Maria; Schumacher, Christoph M; Kohll, A Xavier; Starck, Christoph T; Schmid Daners, Marianne; Meboldt, Mirko; Falk, Volkmar; Stark, Wendelin J

2017-10-01

The technology of 3D-printing has allowed the production of entirely soft pumps with complex chamber geometries. We used this technique to develop a completely soft pneumatically driven total artificial heart from silicone elastomers and evaluated its performance on a hybrid mock circulation. The goal of this study is to present an innovative concept of a soft total artificial heart (sTAH). Using the form of a human heart, we designed a sTAH, which consists of only two ventricles and produced it using a 3D-printing, lost-wax casting technique. The diastolic properties of the sTAH were defined and the performance of the sTAH was evaluated on a hybrid mock circulation under various physiological conditions. The sTAH achieved a blood flow of 2.2 L/min against a systemic vascular resistance of 1.11 mm Hg s/mL (afterload), when operated at 80 bpm. At the same time, the mean pulmonary venous pressure (preload) was fixed at 10 mm Hg. Furthermore, an aortic pulse pressure of 35 mm Hg was measured, with a mean aortic pressure of 48 mm Hg. The sTAH generated physiologically shaped signals of blood flow and pressures by mimicking the movement of a real heart. The preliminary results of this study show a promising potential of the soft pumps in heart replacements. Further work, focused on increasing blood flow and in turn aortic pressure is required. © 2017 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

A Novel Regulatory Function of Sweet Taste-Sensing Receptor in Adipogenic Differentiation of 3T3-L1 Cells

PubMed Central

Masubuchi, Yosuke; Nakagawa, Yuko; Ma, Jinhui; Sasaki, Tsutomu; Kitamura, Tadahiro; Yamamoto, Yoritsuna; Kurose, Hitoshi; Kojima, Itaru; Shibata, Hiroshi

2013-01-01

Background Sweet taste receptor is expressed not only in taste buds but also in nongustatory organs such as enteroendocrine cells and pancreatic beta-cells, and may play more extensive physiological roles in energy metabolism. Here we examined the expression and function of the sweet taste receptor in 3T3-L1 cells. Methodology/Principal Findings In undifferentiated preadipocytes, both T1R2 and T1R3 were expressed very weakly, whereas the expression of T1R3 but not T1R2 was markedly up-regulated upon induction of differentiation (by 83.0 and 3.8-fold, respectively at Day 6). The α subunits of Gs (Gαs) and G14 (Gα14) but not gustducin were expressed throughout the differentiation process. The addition of sucralose or saccharin during the first 48 hours of differentiation considerably reduced the expression of peroxisome proliferator activated receptor γ (PPARγ and CCAAT/enhancer-binding protein α (C/EBPα at Day 2, the expression of aP2 at Day 4 and triglyceride accumulation at Day 6. These anti-adipogenic effects were attenuated by short hairpin RNA-mediated gene-silencing of T1R3. In addition, overexpression of the dominant-negative mutant of Gαs but not YM-254890, an inhibitor of Gα14, impeded the effects of sweeteners, suggesting a possible coupling of Gs with the putative sweet taste-sensing receptor. In agreement, sucralose and saccharin increased the cyclic AMP concentration in differentiating 3T3-L1 cells and also in HEK293 cells heterologously expressing T1R3. Furthermore, the anti-adipogenic effects of sweeteners were mimicked by Gs activation with cholera toxin but not by adenylate cyclase activation with forskolin, whereas small interfering RNA-mediated knockdown of Gαs had the opposite effects. Conclusions 3T3-L1 cells express a functional sweet taste-sensing receptor presumably as a T1R3 homomer, which mediates the anti-adipogenic signal by a Gs-dependent but cAMP-independent mechanism. PMID:23336004

Modification of a deoxynivalenol-antigen-mimicking nanobody to improve immunoassay sensitivity by site-saturation mutagenesis.

PubMed

Qiu, Yu-Lou; He, Qing-Hua; Xu, Yang; Wang, Wei; Liu, Yuan-Yuan

2016-01-01

A nanobody (N-28) which can act as a deoxynivalenol (DON) antigen has been generated, and its residues Thr102-Ser106 were identified to bind with anti-DON monoclonal antibody by alanine-scanning mutagenesis. Site-saturation mutagenesis was used to analyze the plasticity of five residues and to improve the sensitivity of the N-28-based immunoassay. After mutagenesis, three mutants were selected by phage immunoassay and were sequenced. The half-maximal inhibitory concentrations of the immunoassay based on mutants N-28-T102Y, N-28-V103L, and N-28-Y105F were 24.49 ± 1.0, 51.83 ± 2.5, and 35.65 ± 1.6 ng/mL, respectively, showing the assay was, respectively, 3.2, 1.5, and 2.2 times more sensitive than the wild-type-based assay. The best mutant, N-28-T102Y, was used to develop a competitive phage ELISA to detect DON in cereals with high specificity and accuracy. In addition, the structural properties of N-28-T102Y and N-28 were investigated, revealing that the affinity of N-28-T102Y decreased because of increased steric hindrance with the large side chain. The lower-binding-affinity antigen mimetic may contribute to the improvement of the sensitivity of competitive immunoassays. These results demonstrate that nanobodies would be a favorable tool for engineering. Moreover, our results have laid a solid foundation for site-saturation mutagenesis of antigen-mimicking nanobodies to improve immunoassay sensitivity for small molecules.

Progressive external ophthalmoplegia (PEO) due to a mutation in the C10orf2 (PEO1) gene mimicking a myasthenic crisis.

PubMed

Gonzalez-Moron, Dolores; Bueri, Jose; Kauffman, Marcelo Andres

2013-09-07

We described a case of a patient with autosomal dominant progressive external ophthalmoplegia (PEO) who presented with the acute onset dysphagia, quadriparesis, ptosis and respiratory insufficiency following a cardiac procedure and mimicking a myasthenic crisis. A pathogenic mutation in the C10orf2 (PEO1) gene was confirmed. The unusual presentation of our patient contributes to expand the clinical phenotype of PEO1 mutations and reinforces the need to consider mitochondrial myopathy as differential diagnosis of myasthenia gravis even in the case of acute onset symptoms.

A medical device-grade T1 and ECV phantom for global T1 mapping quality assurance-the T1 Mapping and ECV Standardization in cardiovascular magnetic resonance (T1MES) program.

PubMed

Captur, Gabriella; Gatehouse, Peter; Keenan, Kathryn E; Heslinga, Friso G; Bruehl, Ruediger; Prothmann, Marcel; Graves, Martin J; Eames, Richard J; Torlasco, Camilla; Benedetti, Giulia; Donovan, Jacqueline; Ittermann, Bernd; Boubertakh, Redha; Bathgate, Andrew; Royet, Celine; Pang, Wenjie; Nezafat, Reza; Salerno, Michael; Kellman, Peter; Moon, James C

2016-09-22

T 1 mapping and extracellular volume (ECV) have the potential to guide patient care and serve as surrogate end-points in clinical trials, but measurements differ between cardiovascular magnetic resonance (CMR) scanners and pulse sequences. To help deliver T 1 mapping to global clinical care, we developed a phantom-based quality assurance (QA) system for verification of measurement stability over time at individual sites, with further aims of generalization of results across sites, vendor systems, software versions and imaging sequences. We thus created T1MES: The T1 Mapping and ECV Standardization Program. A design collaboration consisting of a specialist MRI small-medium enterprise, clinicians, physicists and national metrology institutes was formed. A phantom was designed covering clinically relevant ranges of T 1 and T 2 in blood and myocardium, pre and post-contrast, for 1.5 T and 3 T. Reproducible mass manufacture was established. The device received regulatory clearance by the Food and Drug Administration (FDA) and Conformité Européene (CE) marking. The T1MES phantom is an agarose gel-based phantom using nickel chloride as the paramagnetic relaxation modifier. It was reproducibly specified and mass-produced with a rigorously repeatable process. Each phantom contains nine differently-doped agarose gel tubes embedded in a gel/beads matrix. Phantoms were free of air bubbles and susceptibility artifacts at both field strengths and T 1 maps were free from off-resonance artifacts. The incorporation of high-density polyethylene beads in the main gel fill was effective at flattening the B 1 field. T 1 and T 2 values measured in T1MES showed coefficients of variation of 1 % or less between repeat scans indicating good short-term reproducibility. Temperature dependency experiments confirmed that over the range 15-30 °C the short-T 1 tubes were more stable with temperature than the long-T 1 tubes. A batch of 69 phantoms was mass-produced with random sampling of

Molecular Mechanism of Species-dependent Sweet Taste toward Artificial Sweeteners

PubMed Central

Liu, Bo; Ha, Matthew; Meng, Xuan-Yu; Kaur, Tanno; Khaleduzzaman, Mohammed; Zhang, Zhe; Jiang, Peihua; Li, Xia; Cui, Meng

2011-01-01

The heterodimer of Tas1R2 and Tas1R3 is a broadly acting sweet taste receptor, which mediates mammalian sweet taste toward natural and artificial sweeteners and sweet-tasting proteins. Perception of sweet taste is a species selective physiological process. For instance, artificial sweeteners aspartame and neotame taste sweet to humans, apes and Old World monkeys but not to New World monkeys and rodents. Although specific regions determining the activation of the receptors by these sweeteners have been identified, the molecular mechanism of species-dependent sweet taste remains elusive. Using human/squirrel monkey chimeras, mutagenesis and molecular modeling, we reveal that the different responses of mammalian species towards the artificial sweeteners aspartame and neotame are determined by the steric effect of a combination of a few residues in the ligand binding pocket. Residues S40 and D142 in the human Tas1R2, which correspond to residues T40 and E142 in the squirrel monkey Tas1R2, were found to be the critical residues for the species dependent difference in sweet taste. In addition, human Tas1R2 residue I67, which corresponds to S67 in squirrel monkey receptor, modulates the higher affinity of neotame than that of aspartame. Our studies not only shed light on the molecular mechanism of species dependent sweet taste toward artificial sweeteners, but also provide guidance for designing novel effective artificial sweet compounds. PMID:21795555

Molecular mechanism of species-dependent sweet taste toward artificial sweeteners.

PubMed

Liu, Bo; Ha, Matthew; Meng, Xuan-Yu; Kaur, Tanno; Khaleduzzaman, Mohammed; Zhang, Zhe; Jiang, Peihua; Li, Xia; Cui, Meng

2011-07-27

The heterodimer of Tas1R2 and Tas1R3 is a broadly acting sweet taste receptor, which mediates mammalian sweet taste toward natural and artificial sweeteners and sweet-tasting proteins. Perception of sweet taste is a species-selective physiological process. For instance, artificial sweeteners aspartame and neotame taste sweet to humans, apes, and Old World monkeys but not to New World monkeys and rodents. Although specific regions determining the activation of the receptors by these sweeteners have been identified, the molecular mechanism of species-dependent sweet taste remains elusive. Using human/squirrel monkey chimeras, mutagenesis, and molecular modeling, we reveal that the different responses of mammalian species toward the artificial sweeteners aspartame and neotame are determined by the steric effect of a combination of a few residues in the ligand binding pocket. Residues S40 and D142 in the human Tas1R2, which correspond to residues T40 and E142 in the squirrel monkey Tas1R2, were found to be the critical residues for the species-dependent difference in sweet taste. In addition, human Tas1R2 residue I67, which corresponds to S67 in squirrel monkey receptor, modulates the higher affinity of neotame than of aspartame. Our studies not only shed light on the molecular mechanism of species-dependent sweet taste toward artificial sweeteners, but also provide guidance for designing novel effective artificial sweet compounds.

BMI-1 Mediates Estrogen-Deficiency-Induced Bone Loss by Inhibiting Reactive Oxygen Species Accumulation and T Cell Activation.

PubMed

Li, Jinbo; Wang, Qian; Yang, Renlei; Zhang, Jiaqi; Li, Xing; Zhou, Xichao; Miao, Dengshun

2017-05-01

Previous studies have shown that estrogen regulates bone homeostasis through regulatory effects on oxidative stress. However, it is unclear how estrogen deficiency triggers reactive oxygen species (ROS) accumulation. Recent studies provide evidence that the B lymphoma Mo-MLV insertion region 1 (BMI-1) plays a critical role in protection against oxidative stress and that this gene is directly regulated by estrogen via estrogen receptor (ER) at the transcriptional level. In this study, ovariectomized mice were given drinking water with/without antioxidant N-acetyl-cysteine (NAC, 1 mg/mL) supplementation, and compared with each other and with sham mice. Results showed that ovariectomy resulted in bone loss with increased osteoclast surface, increased ROS levels, T cell activation, and increased TNF and RANKL levels in serum and in CD4 T cells; NAC supplementation largely prevented these alterations. BMI-1 expression levels were dramatically downregulated in CD4 T cells from ovariectomized mice. We supplemented drinking water to BMI-1-deficient mice with/without NAC and compared them with each other and with wild-type (WT) mice. We found that BMI-1 deficiency mimicked alterations observed in ovariectomy whereas NAC supplementation reversed all alterations induced by BMI-1 deficiency. Because T cells are critical in mediating ovariectomy-induced bone loss, we further assessed whether BMI-1 overexpression in lymphocytes can protect against estrogen deficiency-induced osteoclastogenesis and bone loss by inhibiting oxidative stress, T cell activation, and RANKL production. When WT and Eμ-BMI-1 transgenic mice with BMI-1 specifically overexpressed in lymphocytes were ovariectomized and compared with each other and with WT sham mice, we found that BMI-1 overexpression in lymphocytes clearly reversed all alterations induced by ovariectomy. Results from this study indicate that estrogen deficiency downregulates BMI-1 and subsequently increases ROS, T cell activation, and

SUMOylated IRF-1 shows oncogenic potential by mimicking IRF-2

DOE Office of Scientific and Technical Information (OSTI.GOV)

Park, Sun-Mi; School of Biological Sciences and Biotechnology, Chonnam National University, Gwangju 500-757; Chae, Myounghee

2010-01-01

Interferon regulatory factor-1 (IRF-1) is an interferon-induced transcriptional activator that suppresses tumors by impeding cell proliferation. Recently, we demonstrated that the level of SUMOylated IRF-1 is elevated in tumor cells, and that SUMOylation of IRF-1 attenuates its tumor-suppressive function. Here we report that SUMOylated IRF-1 mimics IRF-2, an antagonistic repressor, and shows oncogenic potential. To demonstrate the role of SUMOylated IRF-1 in tumorigenesis, we used SUMO-IRF-1 recombinant protein. Stable expression of SUMO-IRF-1 in NIH3T3 cells resulted in focus formation and anchorage-independent growth in soft agar. Inoculation of SUMO-IRF-1-transfected cells into athymic nude mice resulted in tumor formation and infiltration ofmore » adipose tissues. Finally, we demonstrated that SUMO-IRF-1 transforms NIH3T3 cells in a dose-dependent manner suggesting that SUMOylated IRF-1 may act as an oncogenic protein in tumor cells.« less

Adrenal cortical oncocytoma mimicking pheochromocytoma.

PubMed

Kiriakopoulos, Andreas; Papaioannou, Dimitrios; Linos, Dimitrios

2011-01-01

Adrenal tumors present with clinical features and signs unique to their specific hormonal hypersecretion. However, there have been cases in which the clinical expression has been in conflict with the histologic features of the tumor. In this communication we report an unusual clinical presentation of an adrenal cortical tumor with histologic features of an oncocytoma that clinically mimicked a pheochromocytoma. A 49-year old man was referred to our Unit due to type B aortic dissection and a mass of the left adrenal gland. Computed tomography and magnetic resonance imaging confirmed the presence of aortic dissection extending from the left subclavian artery to both iliac arteries and also revealed a 6 cm tumor on the left adrenal gland. Preoperative endocrine evaluation showed a near tenfold increase of urinary vanillylmandelic acid (VMA) and metanephrine values. Transperitoneal laparoscopic adrenalectomy was successfully performed. The adrenal tumor proved to be an adrenal cortical neoplasm with histologic features of oncocytoma. Although the case of an adrenal cortical adenoma clinically mimicking a pheochromocytoma has been described in the literature, to the best of our knowledge, there has been no previous report of an adrenal cortical neoplasm with predominant features of oncocytoma.

Floating retained root lesion mimicking apical periodontitis.

PubMed

Chung, Ming-Pang; Chen, Chih-Ping; Shieh, Yi-Shing

2009-10-01

A case of a retained root tip simulating apical periodontitis on radiographic examination is described. The retained root tip, originating from the left lower first molar, floated under the left lower second premolar apical region mimicking apical periodontitis. It appeared as an ill-defined periapical radiolucency containing a smaller radiodense mass on radiograph. The differential diagnosis included focal sclerosing osteomyelitis (condensing osteitis) and ossifying fibroma. Upon exicisional biopsy, a retained root associated with granulation tissue was found. After 1-year follow-up, the patient was asymptomatic and the periradicular lesion was healing. Meanwhile, the associated tooth showed a normal response to stimulation testing.

[Elaboration of Pseudo-natural Products Using Artificial In Vitro Biosynthesis Systems].

PubMed

Goto, Yuki

2018-01-01

 Peptidic natural products often consist of not only proteinogenic building blocks but also unique non-proteinogenic structures such as macrocyclic scaffolds and N-methylated backbones. Since such non-proteinogenic structures are important structural motifs that contribute to diverse bioactivity, we have proposed that peptides with non-proteinogenic structures should be attractive candidates as artificial bioactive peptides mimicking natural products, or so-called pseudo-natural products. We previously devised an engineered translation system for pseudo-natural peptides, referred to as the flexible in vitro translation (FIT) system. This system enabled "one-pot" synthesis of highly diverse pseudo-natural peptide libraries, which can be rapidly screened by mRNA display technology for the discovery of pseudo-natural peptides with diverse bioactivities.

Malignant mesenchymal neoplasms of the dermis and subcutis mimicking benign lesions: a case-based review.

PubMed

Mentzel, Thomas; Brenn, Thomas

2017-11-01

In this short review, malignant mesenchymal neoplasms of the dermis and subcutis mimicking benign lesions and their differential diagnoses are discussed. These include plaque-like dermatofibrosarcoma protuberans, superficial low-grade fibromyxoid sarcoma, low-grade superficial malignant peripheral nerve sheath tumour, epithelioid sarcoma, pseudomyogenic haemangioendothelioma, Kaposi sarcoma mimicking cavernous haemangioma and benign lymphangioendothelioma, and rare forms of angiosarcoma mimicking a benign vascular lesion.

Pre-synaptic glycine GlyT1 transporter--NMDA receptor interaction: relevance to NMDA autoreceptor activation in the presence of Mg2+ ions.

PubMed

Musante, Veronica; Summa, Maria; Cunha, Rodrigo A; Raiteri, Maurizio; Pittaluga, Anna

2011-05-01

Rat hippocampal glutamatergic terminals possess NMDA autoreceptors whose activation by low micromolar NMDA elicits glutamate exocytosis in the presence of physiological Mg(2+) (1.2 mM), the release of glutamate being significantly reduced when compared to that in Mg(2+)-free condition. Both glutamate and glycine were required to evoke glutamate exocytosis in 1.2 mM Mg(2+), while dizocilpine, cis-4-[phosphomethyl]-piperidine-2-carboxylic acid and 7-Cl-kynurenic acid prevented it, indicating that occupation of both agonist sites is needed for receptor activation. D-serine mimicked glycine but also inhibited the NMDA/glycine-induced release of [(3H]D-aspartate, thus behaving as a partial agonist. The NMDA/glycine-induced release in 1.2 mM Mg(2+) strictly depended on glycine uptake through the glycine transporter type 1 (GlyT1), because the GlyT1 blocker N-[3-(4'-fluorophenyl)-3-(4'-phenylphenoxy)propyl])sarcosine hydrochloride, but not the GlyT2 blocker Org 25534, prevented it. Accordingly, [(3)H]glycine was taken up during superfusion, while lowering the external concentration of Na(+), the monovalent cation co-transported with glycine by GlyT1, abrogated the NMDA-induced effect. Western blot analysis of subsynaptic fractions confirms that GlyT1 and NMDA autoreceptors co-localize at the pre-synaptic level, where GluN3A subunits immunoreactivity was also recovered. It is proposed that GlyT1s coexist with NMDA autoreceptors on rat hippocampal glutamatergic terminals and that glycine taken up by GlyT1 may permit physiological activation of NMDA pre-synaptic autoreceptors. © 2011 The Authors. Journal of Neurochemistry © 2011 International Society for Neurochemistry.

Design of a multimodal (1H/23Na MR/CT) anthropomorphic thorax phantom.

PubMed

Neumann, Wiebke; Lietzmann, Florian; Schad, Lothar R; Zöllner, Frank G

2017-06-01

This work proposes a modular, anthropomorphic MR and CT thorax phantom that enables the comparison of experimental studies for quantitative evaluation of deformable, multimodal image registration algorithms and realistic multi-nuclear MR imaging techniques. A human thorax phantom was developed with insertable modules representing lung, liver, ribs and additional tracking spheres. The quality of human tissue mimicking characteristics was evaluated for 1 H and 23 Na MR as well as CT imaging. The position of landmarks in the lung lobes was tracked during CT image acquisition at several positions during breathing cycles. 1 H MR measurements of the liver were repeated after seven months to determine long term stability. The modules possess HU, T 1 and T 2 values comparable to human tissues (lung module: -756±148HU, artificial ribs: 218±56HU (low CaCO 3 concentration) and 339±121 (high CaCO 3 concentration), liver module: T 1 =790±28ms, T 2 =65±1ms). Motion analysis showed that the landmarks in the lung lobes follow a 3D trajectory similar to human breathing motion. The tracking spheres are well detectable in both CT and MRI. The parameters of the tracking spheres can be adjusted in the following ranges to result in a distinct signal: HU values from 150 to 900HU, T 1 relaxation time from 550ms to 2000ms, T 2 relaxation time from 40ms to 200ms. The presented anthropomorphic multimodal thorax phantom fulfills the demands of a simple, inexpensive system with interchangeable components. In future, the modular design allows for complementing the present set up with additional modules focusing on specific research targets such as perfusion studies, 23 Na MR quantification experiments and an increasing level of complexity for motion studies. Copyright © 2016. Published by Elsevier GmbH.

First step in developing a 3D biodegradable fibrin scaffold for an artificial ovary

PubMed Central

2013-01-01

Background Although transplantation of cryopreserved ovarian tissue is a promising approach to restore fertility in cancer patients, it is not advisable for women at risk of ovarian involvement due to the threat of reintroducing malignant cells. The aim of this study was therefore to find an alternative for these patients by development of an artificial ovary. Methods For construction of the artificial ovary matrix, we used a central composite design to investigate nine combinations of fibrinogen (mg/ml) and thrombin (IU/mL) (F/T): F1/T4, F12.5/T1, F12.5/T20, F25/T0.1, F25/T4, F25/T500, F50/T1, F50/T20 and F100/T4. From the first qualitative analyses (handling and matrix size), five combinations (F12.5/T1, F25/T4, F50/T20, F50/T1 and F100/T4) yielded positive results. They were further evaluated in order to assess fibrin matrix degradation and homogeneous cell encapsulation (density), survival and proliferation (Ki67), and atresia (TUNEL) before and after 7 days of in vitro culture. To determine the best compromise between maximizing the dynamic density (Y1) and minimizing the apoptosis rate (Y2), we used the desirability function approach. Results Two combinations (F12.5/T1 and F25/T4) showed greater distribution of cells before in vitro culture, reproducible degradation of the fibrin network and adequate support for isolated human ovarian stromal cells, with a high proportion of Ki67-positive cells. SEM analysis revealed a network of fibers with regular pores and healthy stromal cells after in vitro culture with both F/T combinations. Conclusion This study reports two optimal F/T combinations that allow survival and proliferation of isolated human ovarian cells. Further studies are required to determine if such a scaffold will also be a suitable environment for isolated ovarian follicles. PMID:24274108

First step in developing a 3D biodegradable fibrin scaffold for an artificial ovary.

PubMed

Luyckx, Valérie; Dolmans, Marie-Madeleine; Vanacker, Julie; Scalercio, Sarah R; Donnez, Jacques; Amorim, Christiani A

2013-11-25

Although transplantation of cryopreserved ovarian tissue is a promising approach to restore fertility in cancer patients, it is not advisable for women at risk of ovarian involvement due to the threat of reintroducing malignant cells. The aim of this study was therefore to find an alternative for these patients by development of an artificial ovary. For construction of the artificial ovary matrix, we used a central composite design to investigate nine combinations of fibrinogen (mg/ml) and thrombin (IU/mL) (F/T): F1/T4, F12.5/T1, F12.5/T20, F25/T0.1, F25/T4, F25/T500, F50/T1, F50/T20 and F100/T4. From the first qualitative analyses (handling and matrix size), five combinations (F12.5/T1, F25/T4, F50/T20, F50/T1 and F100/T4) yielded positive results. They were further evaluated in order to assess fibrin matrix degradation and homogeneous cell encapsulation (density), survival and proliferation (Ki67), and atresia (TUNEL) before and after 7 days of in vitro culture. To determine the best compromise between maximizing the dynamic density (Y1) and minimizing the apoptosis rate (Y2), we used the desirability function approach. Two combinations (F12.5/T1 and F25/T4) showed greater distribution of cells before in vitro culture, reproducible degradation of the fibrin network and adequate support for isolated human ovarian stromal cells, with a high proportion of Ki67-positive cells. SEM analysis revealed a network of fibers with regular pores and healthy stromal cells after in vitro culture with both F/T combinations. This study reports two optimal F/T combinations that allow survival and proliferation of isolated human ovarian cells. Further studies are required to determine if such a scaffold will also be a suitable environment for isolated ovarian follicles.

Short-term plasticity and long-term potentiation mimicked in single inorganic synapses

NASA Astrophysics Data System (ADS)

Ohno, Takeo; Hasegawa, Tsuyoshi; Tsuruoka, Tohru; Terabe, Kazuya; Gimzewski, James K.; Aono, Masakazu

2011-08-01

Memory is believed to occur in the human brain as a result of two types of synaptic plasticity: short-term plasticity (STP) and long-term potentiation (LTP; refs , , , ). In neuromorphic engineering, emulation of known neural behaviour has proven to be difficult to implement in software because of the highly complex interconnected nature of thought processes. Here we report the discovery of a Ag2S inorganic synapse, which emulates the synaptic functions of both STP and LTP characteristics through the use of input pulse repetition time. The structure known as an atomic switch, operating at critical voltages, stores information as STP with a spontaneous decay of conductance level in response to intermittent input stimuli, whereas frequent stimulation results in a transition to LTP. The Ag2S inorganic synapse has interesting characteristics with analogies to an individual biological synapse, and achieves dynamic memorization in a single device without the need of external preprogramming. A psychological model related to the process of memorizing and forgetting is also demonstrated using the inorganic synapses. Our Ag2S element indicates a breakthrough in mimicking synaptic behaviour essential for the further creation of artificial neural systems that emulate characteristics of human memory.

GLP-1 secretion is stimulated by 1,10-phenanthroline via colocalized T2R5 signal transduction in human enteroendocrine L cell

DOE Office of Scientific and Technical Information (OSTI.GOV)

Park, Jiyoung; Kim, Ki-Suk; Kim, Kang-Hoon

Glucagon-like peptide-1 (GLP-1) hormone is known to regulate blood glucose by an insulinotropic effect and increases proliferation as and also prevents apoptosis of pancreatic β cells. We know that GLP-1 is secreted by nutrients such as fatty acids and sweet compounds but also bitter compounds via stimulation of G-protein coupled receptors (GPCRs) in the gut. Among these, bitter compounds are multiply-contained in phytochemicals or artificial materials and perceived as ligands of various bitter taste receptors. We hypothesized that GLP-1 hormone is secreted through stimulation of a single bitter taste receptor by 1,10-phenanthroline which is known agonist of taste receptor typemore » 2 member 5 (T2R5). To prove this hypothesis, we used the representatively well-known 1,10-phenanthroline as ligand of single receptor and evaluated the existence of T2R5 by double-labeling immunofluorescence and then 1,10-phenanthroline is able to secrete GLP-1 hormone through stimulation of T2R5 in human enteroendocrine cells. Consequently, we verify that GLP-1 hormone is colocalized with T2R5 in the human duodenum and ileum tissue and is secreted by 1,10-phenanthroline via T2R5 signal transduction in differentiated human enteroendocrine L cells. - Highlights: • Taste receptor type 2 member 5 (T2R5) is colocalized with GLP-1 hormone in human enteroendocrine cells. • GLP-1 secretion is stimulated by 1,10-phenanthroline via stimulation of T2R5. • Inhibition of the bitter taste pathway reduce GLP-1 secretion.« less

Pseudocarcinomatous hyperplasia of the fallopian tube mimicking tubal cancer: a radiological and pathological diagnostic challenge.

PubMed

Lee, Nam Kyung; Choi, Kyung Un; Han, Ga Jin; Kwon, Byung Su; Song, Yong Jung; Suh, Dong Soo; Kim, Ki Hyung

2016-11-14

Pseudocarcinomatous hyperplasia of the fallopian tube is a rare, benign disease characterized by florid epithelial hyperplasia. The authors present the history and details of a 22-year-old woman with bilateral pelvic masses and a highly elevated serum CA-125 level (1,056 U/ml). Ultrasonography and magnetic resonance imaging (MRI) of the pelvis showed bilateral adnexal complex cystic masses with a fusiform or sausage-like shape. Contrast-enhanced fat-suppressed T1-weighted images showed enhancement of papillary projections of the right adnexal mass and enhancement of an irregular thick wall on the left adnexal mass, suggestive of tubal cancer. Based on MRI and laboratory findings, laparotomy was performed under a putative preoperative diagnosis of tubal cancer. The final pathologic diagnosis was pseudocarcinomatous hyperplasia of tubal epithelium associated with acute and chronic salpingitis in both tubes. The authors report a rare case of pseudocarcinomatous hyperplasia of the fallopian tubes mimicking tubal cancer.

Artificially layered films of CuBa{sub 2} (Ca{sub 1{minus}x}Sr{sub x}){sub n{minus}1}Cu{sub n}O{sub y} grown using pulsed laser deposition

DOE Office of Scientific and Technical Information (OSTI.GOV)

Aruta, C.; Balestrino, G.; Martellucci, S.

We have shown that the pulsed laser deposition technique (PLD) can be successfully used to grow artificially layered films of the CuBa{sub 2}(Ca{sub 1{minus}x}Sr{sub x}){sub n{minus}1}Cu{sub n}O{sub y} compound using only two targets having nominal composition BaCuO{sub y} and (Ca{sub 1{minus}x}Sr{sub x})CuO{sub y}, respectively. n was varied between 2 and 5. We have demonstrated, by a kinematic analysis of the x-ray diffraction spectra that the average random discrete thickness fluctuations which affect both the BaCuO{sub y} and (Ca{sub 1{minus}x}Sr{sub x})CuO{sub y} layers are much smaller than one atomic layer. Such features are confirmed by the appearance of sharp peaks evenmore » for the n=2 artificially layered structure where only one (Ca{sub 1{minus}x}Sr{sub x})CuO{sub y} cell is deposited in the stacking sequence. These results show that truly new structures can be obtained by a layer by layer deposition technique with a low interfacial disorder and give strong support to the idea of synthesizing new artificial high T{sub c} structures by the PLD technique.{copyright} {ital 1997 American Institute of Physics.}« less

26 CFR 1.382-1T - [Reserved

Code of Federal Regulations, 2010 CFR

2010-04-01

... 26 Internal Revenue 4 2010-04-01 2010-04-01 false [Reserved] 1.382-1T Section 1.382-1T Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) INCOME TAX (CONTINUED) INCOME TAXES Insolvency Reorganizations § 1.382-1T [Reserved] ...

Comparison of dual-hormone artificial pancreas, single-hormone artificial pancreas, and conventional insulin pump therapy for glycaemic control in patients with type 1 diabetes: an open-label randomised controlled crossover trial.

PubMed

Haidar, Ahmad; Legault, Laurent; Messier, Virginie; Mitre, Tina Maria; Leroux, Catherine; Rabasa-Lhoret, Rémi

2015-01-01

The artificial pancreas is an emerging technology for the treatment of type 1 diabetes and two configurations have been proposed: single-hormone (insulin alone) and dual-hormone (insulin and glucagon). We aimed to delineate the usefulness of glucagon in the artificial pancreas system. We did a randomised crossover trial of dual-hormone artificial pancreas, single-hormone artificial pancreas, and conventional insulin pump therapy (continuous subcutaneous insulin infusion) in participants aged 12 years or older with type 1 diabetes. Participants were assigned in a 1:1:1:1:1:1 ratio with blocked randomisation to the three interventions and attended a research facility for three 24-h study visits. During visits when the patient used the single-hormone artificial pancreas, insulin was delivered based on glucose sensor readings and a predictive dosing algorithm. During dual-hormone artificial pancreas visits, glucagon was also delivered during low or falling glucose. During conventional insulin pump therapy visits, patients received continuous subcutaneous insulin infusion. The study was not masked. The primary outcome was the time for which plasma glucose concentrations were in the target range (4·0-10·0 mmol/L for 2 h postprandially and 4·0-8·0 mmol/L otherwise). Hypoglycaemic events were defined as plasma glucose concentration of less than 3·3 mmol/L with symptoms or less than 3·0 mmol/L irrespective of symptoms. Analysis was by modified intention to treat, in which we included data for all patients who completed at least two visits. A p value of less than 0·0167 (0·05/3) was regarded as significant. This trial is registered with ClinicalTrials.gov, number NCT01754337. The mean proportion of time spent in the plasma glucose target range over 24 h was 62% (SD 18), 63% (18), and 51% (19) with single-hormone artificial pancreas, dual-hormone artificial pancreas, and conventional insulin pump therapy, respectively. The mean difference in time spent in the target

A kidney injury molecule-1 (Kim-1) gene reporter in a mouse artificial chromosome: the responsiveness to cisplatin toxicity in immortalized mouse kidney S3 cells.

PubMed

Kokura, Kenji; Kuromi, Yasushi; Endo, Takeshi; Anzai, Naohiko; Kazuki, Yasuhiro; Oshimura, Mitsuo; Ohbayashi, Tetsuya

2016-10-01

Kidney injury molecule-1 (Kim-1) has been validated as a urinary biomarker for acute and chronic renal damage. The expression of Kim-1 mRNA is also activated by acute kidney injury induced by cisplatin in rodents and humans. To date, the measurement of Kim-1 expression has not fully allowed the detection of in vitro cisplatin nephrotoxicity in immortalized culture cells, such as human kidney-2 cells and immortalized proximal tubular epithelial cells. We measured the augmentation of Kim-1 mRNA expression after the addition of cisplatin using immortalized S3 cells established from the kidneys of transgenic mice harboring temperature-sensitive large T antigen from Simian virus 40. A mouse Kim-1 gene luciferase reporter in conjunction with an Hprt gene reporter detected cisplatin-induced nephrotoxicity in S3 cells. These two reporter genes were contained in a mouse artificial chromosome, and two luciferases that emitted different wavelengths were used to monitor the respective gene expression. However, the Kim-1 reporter gene failed to respond to cisplatin in A9 fibroblast cells that contained the same reporter mouse artificial chromosome, suggesting cell type-specificity for activation of the reporter. We report the feasibility of measuring in vitro cisplatin nephrotoxicity using a Kim-1 reporter gene in S3 cells. © 2016 The Authors. The Journal of Gene Medicine Published by John Wiley & Sons, Ltd.

Artificial engineering of secondary lymphoid organs.

PubMed

Tan, Jonathan K H; Watanabe, Takeshi

2010-01-01

Secondary lymphoid organs such as spleen and lymph nodes are highly organized immune structures essential for the initiation of immune responses. They display distinct B cell and T cell compartments associated with specific stromal follicular dendritic cells and fibroblastic reticular cells, respectively. Interweaved through the parenchyma is a conduit system that distributes small antigens and chemokines directly to B and T cell zones. While most structural aspects between lymph nodes and spleen are common, the entry of lymphocytes, antigen-presenting cells, and antigen into lymphoid tissues is regulated differently, reflecting the specialized functions of each organ in filtering either lymph or blood. The overall organization of lymphoid tissue is vital for effective antigen screening and recognition, and is a feature which artificially constructed lymphoid organoids endeavor to replicate. Synthesis of artificial lymphoid tissues is an emerging field that aims to provide therapeutic application for the treatment of severe infection, cancer, and age-related involution of secondary lymphoid tissues. The development of murine artificial lymphoid tissues has benefited greatly from an understanding of organogenesis of lymphoid organs, which has delineated cellular and molecular elements essential for the recruitment and organization of lymphocytes into lymphoid structures. Here, the field of artificial lymphoid tissue engineering is considered including elements of lymphoid structure and development relevant to organoid synthesis. (c) 2010 Elsevier Inc. All rights reserved.

Classification of Respiratory Sounds by Using An Artificial Neural Network

DTIC Science & Technology

2001-10-28

CLASSIFICATION OF RESPIRATORY SOUNDS BY USING AN ARTIFICIAL NEURAL NETWORK M.C. Sezgin, Z. Dokur, T. Ölmez, M. Korürek Department of Electronics and...successfully classified by the GAL network. Keywords-Respiratory Sounds, Classification of Biomedical Signals, Artificial Neural Network . I. INTRODUCTION...process, feature extraction, and classification by the artificial neural network . At first, the RS signal obtained from a real-time measurement equipment is

Feasibility of a nickel-metal hydride battery for totally implantable artificial hearts.

PubMed

Okamoto, E; Yoshida, T; Fujiyoshi, M; Shimanaka, M; Takeuchi, A; Mitamura, Y; Mikami, T

1996-01-01

An implantable rechargeable battery is one of the key technologies for totally implantable artificial hearts. The nickel-metal hydride (Ni-MH) battery is promising for its high energy density of 1.5-2.0 times that of a nickel-cadmium battery. In this study, the effects of pulsatile discharge loads on the operating time and cycle life of Ni-MH batteries at 39 degrees C were studied. Two battery cells (TH-3M, 1,200 mAh, phi 14.5 x 49 mm; Toshiba, Tokyo, Japan) in series were charge/discharge cycled at 39 degrees C using a charge current of 1CA (1,200 mA) and then were fully discharged to 1.0 V/cell under either pulsatile discharge loads, which mimicked a systole (1 A for 0.3 sec) and a diastole (0.4 A for 0.3 sec), or a non pulsatile discharge load equivalent to the average of the pulsatile loads (0.7 A). Each cycle life test was interrupted on the 482nd cycle under pulsatile load, and on the 423rd cycle under non pulsatile load, because of malfunction of each battery charger. The tests showed that the pulsatile discharge cells had significantly (p < 0.001) less operating time (74.0 +/- 7.15 min) throughout the test period (up to 482 days) compared to the cells under equivalent non pulsatile discharge loads (93.7 +/- 7.74 min). The pulsatile-discharged Ni-MH cells provide significantly less operating time than the constantly discharged cells; the Ni-MH battery has an operating time of over 78 min and a cycle life of almost 500 cycles at 39 degrees C. In conclusion, the Ni-MH battery is feasible as an implantable back-up battery for a totally implantable artificial heart system.

CARS and SHG microscopy of artificial bioengineered tissues

NASA Astrophysics Data System (ADS)

Enejder, Annika; Brackmann, Christian; Dahlberg, Jan-Olof; Vrana, Engin; Gatenholm, Paul

2010-02-01

Major efforts are presently made to develop artificial replacement tissues with optimal architectural and material characteristics, mimicking those of their natural correspondents. Encouraged by the readiness with which cellulose fibers woven by the bacteria Acetobacter xylinum can be formed into organ-like macroscopic shapes and with different microscopic textures, it emerges as an interesting material within tissue engineering. We have developed a protocol employing simultaneous CARS and SHG microscopy for monitoring the cellulose network characteristics and its impact on the integration of smooth muscle cells (SMCs) for functionalized artificial tissues. CARS and SHG overlay images of the cells and the cellulose fibers reveal an immediate interaction irrespective of scaffold morphology and that the SMCs attach to the cellulose fibers already during the first cultivation day without cell-adhesive coatings. During the subsequent 28 days, SMCs were found to readily proliferate and differentiate on the cellulose scaffold without the need for exogenous growth factors. However, the efficiency with which this occurred depended on the topography of the cellulose constructs, benefited by porous and less compact matrices. This brings forward the need for in-depth studies on how the microstructure of tissue scaffolds influences and can be optimized for native cell integration and proliferation, studies where the benefits of multi-modal non-linear microscopy can be fully exploited.

Acute corneal hydrops mimicking full thickness perforation.

PubMed

Ch'ng, S W; Pillai, M B; Aazeem, S; Tu, K L

2012-05-11

A 26-year-old Caucasian female with keratoconus presented with an acutely painful and red left eye. Visual acuity on presentation was 3/60. Slit lamp examination revealed localised Descemet's membrane break with iris partially plugging it. There was a bulging stromal cyst which would intermittently flatten and reform. The appearance when the cyst was flattened mimicked a full thickness corneal perforation. However, no obvious overlying epithelial defect was detected and an intermittent leakage through micro-perforations in the corneal epithelium was the probable cause of the variable appearance. The anterior chamber reformed and iris plug freed following an insertion of a bandage contact lens and taped eyelid. On follow-up, the Descement's membrane had healed with visual acuity improving to 6/18. Our case illustrates the importance of identifying corneal hydrops mimicking a full thickness perforation as conservative management has a greater chance of recovery.

Mesalamine treatment mimicking relapse in a child with ulcerative colitis.

PubMed

Hojsak, Iva; Pavić, Ana M; Kolaček, Sanja

2014-11-01

There are reports on mesalamine-induced bloody diarrhea mimicking ulcerative colitis (UC) relapse, mostly in adults. Herein we present a case of a child with UC who developed relapse of hemorrhagic colitis related to mesalamine. A 10-year-old girl developed severe symptoms mimicking UC relapse 3 weeks after introduction of mesalamine therapy. After mesalamine was withdrawn, her symptoms improved, but deteriorated again during the challenge of mesalamine despite concomitant use of corticosteroids. This is the first case report on such a young child during the concomitant use of corticosteroids.

A bio-inspired real-time capable artificial lateral line system for freestream flow measurements.

PubMed

Abels, C; Qualtieri, A; De Vittorio, M; Megill, W M; Rizzi, F

2016-06-03

To enhance today's artificial flow sensing capabilities in aerial and underwater robotics, future robots could be equipped with a large number of miniaturized sensors distributed over the surface to provide high resolution measurement of the surrounding fluid flow. In this work we show a linear array of closely separated bio-inspired micro-electro-mechanical flow sensors whose sensing mechanism is based on a piezoresistive strain-gauge along a stress-driven cantilever beam, mimicking the biological superficial neuromasts found in the lateral line organ of fishes. Aiming to improve state-of-the-art flow sensing capability in autonomously flying and swimming robots, our artificial lateral line system was designed and developed to feature multi-parameter freestream flow measurements which provide information about (1) local flow velocities as measured by the signal amplitudes from the individual cantilevers as well as (2) propagation velocity, (3) linear forward/backward direction along the cantilever beam orientation and (4) periodicity of pulses or pulse trains determined by cross-correlating sensor signals. A real-time capable cross-correlation procedure was developed which makes it possible to extract freestream flow direction and velocity information from flow fluctuations. The computed flow velocities deviate from a commercial system by 0.09 m s(-1) at 0.5 m s(-1) and 0.15 m s(-1) at 1.0 m s(-1) flow velocity for a sampling rate of 240 Hz and a sensor distance of 38 mm. Although experiments were performed in air, the presented flow sensing system can be applied to underwater vehicles as well, once the sensors are embedded in a waterproof micro-electro-mechanical systems package.

Distinct Morphology of Human T-Cell Leukemia Virus Type 1-Like Particles

PubMed Central

Maldonado, José O.; Cao, Sheng; Zhang, Wei; Mansky, Louis M.

2016-01-01

The Gag polyprotein is the main retroviral structural protein and is essential for the assembly and release of virus particles. In this study, we have analyzed the morphology and Gag stoichiometry of human T-cell leukemia virus type 1 (HTLV-1)-like particles and authentic, mature HTLV-1 particles by using cryogenic transmission electron microscopy (cryo-TEM) and scanning transmission electron microscopy (STEM). HTLV-1-like particles mimicked the morphology of immature authentic HTLV-1 virions. Importantly, we have observed for the first time that the morphology of these virus-like particles (VLPs) has the unique local feature of a flat Gag lattice that does not follow the curvature of the viral membrane, resulting in an enlarged distance between the Gag lattice and the viral membrane. Other morphological features that have been previously observed with other retroviruses include: (1) a Gag lattice with multiple discontinuities; (2) membrane regions associated with the Gag lattice that exhibited a string of bead-like densities at the inner leaflet; and (3) an arrangement of the Gag lattice resembling a railroad track. Measurement of the average size and mass of VLPs and authentic HTLV-1 particles suggested a consistent range of size and Gag copy numbers in these two groups of particles. The unique local flat Gag lattice morphological feature observed suggests that HTLV-1 Gag could be arranged in a lattice structure that is distinct from that of other retroviruses characterized to date. PMID:27187442

Evaluation of B1 inhomogeneity effect on DCE-MRI data analysis of brain tumor patients at 3T.

PubMed

Sengupta, Anirban; Gupta, Rakesh Kumar; Singh, Anup

2017-12-02

Dynamic-contrast-enhanced (DCE) MRI data acquired using gradient echo based sequences is affected by errors in flip angle (FA) due to transmit B 1 inhomogeneity (B 1 inh). The purpose of the study was to evaluate the effect of B 1 inh on quantitative analysis of DCE-MRI data of human brain tumor patients and to evaluate the clinical significance of B 1 inh correction of perfusion parameters (PPs) on tumor grading. An MRI study was conducted on 35 glioma patients at 3T. The patients had histologically confirmed glioma with 23 high-grade (HG) and 12 low-grade (LG). Data for B 1 -mapping, T 1 -mapping and DCE-MRI were acquired. Relative B 1 maps (B 1rel ) were generated using the saturated-double-angle method. T 1 -maps were computed using the variable flip-angle method. Post-processing was performed for conversion of signal-intensity time (S(t)) curve to concentration-time (C(t)) curve followed by tracer kinetic analysis (K trans , Ve, Vp, Kep) and first pass analysis (CBV, CBF) using the general tracer-kinetic model. DCE-MRI data was analyzed without and with B 1 inh correction and errors in PPs were computed. Receiver-operating-characteristic (ROC) analysis was performed on HG and LG patients. Simulations were carried out to understand the effect of B 1 inhomogeneity on DCE-MRI data analysis in a systematic way. S(t) curves mimicking those in tumor tissue, were generated and FA errors were introduced followed by error analysis of PPs. Dependence of FA-based errors on the concentration of contrast agent and on the duration of DCE-MRI data was also studied. Simulations were also done to obtain K trans of glioma patients at different B 1rel values and see whether grading is affected or not. Current study shows that B 1rel value higher than nominal results in an overestimation of C(t) curves as well as derived PPs and vice versa. Moreover, at same B 1rel values, errors were large for larger values of C(t). Simulation results showed that grade of patients can change

Artificial selection on male genitalia length alters female brain size.

PubMed

Buechel, Séverine D; Booksmythe, Isobel; Kotrschal, Alexander; Jennions, Michael D; Kolm, Niclas

2016-11-30

Male harassment is a classic example of how sexual conflict over mating leads to sex-specific behavioural adaptations. Females often suffer significant costs from males attempting forced copulations, and the sexes can be in an arms race over male coercion. Yet, despite recent recognition that divergent sex-specific interests in reproduction can affect brain evolution, sexual conflict has not been addressed in this context. Here, we investigate whether artificial selection on a correlate of male success at coercion, genital length, affects brain anatomy in males and females. We analysed the brains of eastern mosquitofish (Gambusia holbrooki), which had been artificially selected for long or short gonopodium, thereby mimicking selection arising from differing levels of male harassment. By analogy to how prey species often have relatively larger brains than their predators, we found that female, but not male, brain size was greater following selection for a longer gonopodium. Brain subregion volumes remained unchanged. These results suggest that there is a positive genetic correlation between male gonopodium length and female brain size, which is possibly linked to increased female cognitive ability to avoid male coercion. We propose that sexual conflict is an important factor in the evolution of brain anatomy and cognitive ability. © 2016 The Author(s).

Enterovirus Exposure Uniquely Discriminates Type 1 Diabetes Patients with a Homozygous from a Heterozygous Melanoma Differentiation-Associated Protein 5/Interferon Induced with Helicase C Domain 1 A946T Genotype.

PubMed

Schulte, Barbara M; Gielen, Paul R; Kers-Rebel, Esther D; Prosser, Amy C; Lind, Katharina; Flodström-Tullberg, Malin; Tack, Cees J; Elving, Lammy D; Adema, Gosse J

2016-09-01

In children at risk for type 1 diabetes, innate immune activity is detected before seroconversion. Enterovirus infections have been linked to diabetes development, and a polymorphism (A946T) in the innate immune sensor recognizing enterovirus RNA, interferon-induced with helicase C domain 1/melanoma differentiation-associated protein 5, predisposes to disease. We hypothesized that the strength of innate antienteroviral responses is affected in autoimmune type 1 diabetes patients and linked to the A946T polymorphism. We compared induction of interferon-stimulated genes (ISGs) in peripheral blood mononuclear cells (PBMCs) and dendritic cells (DCs) in healthy individuals and diabetes patients upon stimulation with enterovirus, enterovirus-antibody complexes, or ligands mimicking infection in relation to the A946T polymorphism. Overall, PBMCs of diabetes patients and healthy donors showed comparable ISG induction upon stimulation. No differences were observed in DCs. Interestingly, the data imply that the magnitude of responses to enterovirus and enterovirus-antibody complexes in PBMCs is critically influenced by the A946T polymorphism and elevated in heterozygotes compared to TT homozygous individuals in autoimmune diabetes patients, but not healthy controls. These data imply an intrinsic difference in the responses to enterovirus and enterovirus-antibody complexes in diabetes patients carrying a TT risk genotype compared to heterozygotes that may influence control of enterovirus clearance.

Crystal Structures of HLA-A*0201 Complexed with Melan-A/MART-1[subscript 26(27L)-35] Peptidomimetics Reveal Conformational Heterogeneity and Highlight Degeneracy of T Cell Recognition

DOE Office of Scientific and Technical Information (OSTI.GOV)

Douat-Casassus, Celine; Borbulevych, Oleg; Tarbe, Marion

2010-10-07

There is growing interest in using tumor associated antigens presented by class I major histocompatibility complex (MHC-I) proteins as cancer vaccines. As native peptides are poorly stable in biological fluids, researchers have sought to engineer synthetic peptidomimetics with greater biostability. Here, we demonstrate that antigenic peptidomimetics of the Melan-A/MART-1{sub 26(27L)-35} melanoma antigen adopt strikingly different conformations when bound to MHC-I, highlighting the degeneracy of T cell recognition and revealing the challenges associated with mimicking native peptide conformation.

Tongue metastasis mimicking an abscess.

PubMed

Mavili, Ertuğrul; Oztürk, Mustafa; Yücel, Tuba; Yüce, Imdat; Cağli, Sedat

2010-03-01

Primary tumors metastasizing to the oral cavity are extremely rare. Lung is one of the most common primary sources of metastases to the tongue. Although the incidence of lung cancer is increasing, tongue metastasis as the initial presentation of the tumor remains uncommon. Due to the rarity of tongue metastasis, little is known about its imaging findings. Herein we report the magnetic resonance imaging and clinical findings of a lingual metastasis, mimicking an abscess, from a primary lung cancer.

Amplified biosensing using the horseradish peroxidase-mimicking DNAzyme as an electrocatalyst.

PubMed

Pelossof, Gilad; Tel-Vered, Ran; Elbaz, Johann; Willner, Itamar

2010-06-01

The hemin/G-quadruplex horseradish peroxidase-mimicking DNAzyme is assembled on Au electrodes. It reveals bioelectrocatalytic properties and electrocatalyzes the reduction of H(2)O(2). The bioelectrocatalytic functions of the hemin/G-quadruplex DNAzyme are used to develop electrochemical sensors that follow the activity of glucose oxidase and biosensors for the detection of DNA or low-molecular-weight substrates (adenosine monophosphate, AMP). Hairpin nucleic structures that include the G-quadruplex sequence in a caged configuration and the nucleic acid sequence complementary to the analyte DNA, or the aptamer sequence for AMP, are immobilized on Au-electrode surfaces. In the presence of the DNA analyte, or AMP, the hairpin structures are opened, and the hemin/G-quadruplex horseradish peroxidase-mimicking DNAzyme structures are generated on the electrode surfaces. The bioelectrocatalytic cathodic currents generated by the functionalized electrodes, upon the electrochemical reduction of H(2)O(2), provide a quantitative measure for the detection of the target analytes. The DNA target was analyzed with a detection limit of 1 x 10(-12) M, while the detection limit for analyzing AMP was 1 x 10(-6) M. Methods to regenerate the sensing surfaces are presented.

Artificial bias typically neglected in comparisons of uncertain atmospheric data

NASA Astrophysics Data System (ADS)

Pitkänen, Mikko R. A.; Mikkonen, Santtu; Lehtinen, Kari E. J.; Lipponen, Antti; Arola, Antti

2016-09-01

Publications in atmospheric sciences typically neglect biases caused by regression dilution (bias of the ordinary least squares line fitting) and regression to the mean (RTM) in comparisons of uncertain data. We use synthetic observations mimicking real atmospheric data to demonstrate how the biases arise from random data uncertainties of measurements, model output, or satellite retrieval products. Further, we provide examples of typical methods of data comparisons that have a tendency to pronounce the biases. The results show, that data uncertainties can significantly bias data comparisons due to regression dilution and RTM, a fact that is known in statistics but disregarded in atmospheric sciences. Thus, we argue that often these biases are widely regarded as measurement or modeling errors, for instance, while they in fact are artificial. It is essential that atmospheric and geoscience communities become aware of and consider these features in research.

Visualized and precise design of artificial small RNAs for regulating T7 RNA polymerase and enhancing recombinant protein folding in Escherichia coli.

PubMed

Zhao, Yujia; Fan, Jingjing; Li, Jinlin; Li, Jun; Zhou, Xiaohong; Li, Chun

2016-12-01

Small non-coding RNAs (sRNAs) have received much attention in recent years due to their unique biological properties, which can efficiently and specifically tune target gene expressions in bacteria. Inspired by natural sRNAs, recent works have proposed the use of artificial sRNAs (asRNAs) as genetic tools to regulate desired gene that has been applied in several fields, such as metabolic engineering and bacterial physiology studies. However, the rational design of asRNAs is still a challenge. In this study, we proposed structure and length as two criteria to implement rational visualized and precise design of asRNAs. T7 expression system was one of the most useful recombinant protein expression systems. However, it was deeply limited by the formation of inclusion body. To settle this problem, we designed a series of asRNAs to inhibit the T7 RNA polymerase (Gene1) expression to balance the rate between transcription and folding of recombinant protein. Based on the heterologous expression of Aspergillus oryzae Li-3 glucuronidase in E. coli , the asRNA-antigene1-17bp can effectively decrease the inclusion body and increase the enzyme activity by 169.9%.

Upregulation of Endogenous HMOX1 Expression by a Computer-Designed Artificial Transcription Factor

PubMed Central

Guo, Hongfeng; Tian, Yi; Lu, Hai; Wei, Yong; Ying, Dajun

2010-01-01

Heme oxygenase-1 (HO-1) is well known as a cytoprotective factor. Research has revealed that it is a promising therapeutic target for cardiovascular diseases. In the current study, an HMOX1 (HO-1 gene) enhancer-specific artificial zinc-finger protein (AZP) was designed using bioinformatical methods. Then, an artificial transcription factor (ATF) was constructed based on the AZP. In the ATF, the p65 functional domain was used as the effector domain (ED), and a nuclear localization sequence (NLS) was also included. We next analyzed the affinity of the ATF to the HMOX1 enhancer and the effect of the ATF on endogenous HMOX1 expression. The results suggest that the ATF could effectively upregulate endogenous HMOX1 expression in ECV304 cells. With further research, the ATF could be developed as a potential drug for cardiovascular diseases. PMID:20706680

Inflammatory Myofibroblastic Tumor Mimicking Apical Periodontitis.

PubMed

Adachi, Makoto; Kiho, Kazuki; Sekine, Genta; Ohta, Takahisa; Matsubara, Makoto; Yoshida, Takakazu; Katsumata, Akitoshi; Tanuma, Jun-ichi; Sumitomo, Shinichiro

2015-12-01

Inflammatory myofibroblastic tumors (IMTs) are rare. IMTs of the head and neck occur in all age groups, from neonates to old age, with the highest incidence occurring in childhood and early adulthood. An IMT has been defined as a histologically distinctive lesion of uncertain behavior. This article describes an unusual case of IMT mimicking apical periodontitis in the mandible of a 42-year-old man. At first presentation, the patient showed spontaneous pain and percussion pain at teeth #28 to 30, which continued after initial endodontic treatment. Panoramic radiography revealed a radiolucent lesion at the site. Cone-beam computed tomographic imaging showed osteolytic lesions, suggesting an aggressive neoplasm requiring incisional biopsy. Histopathological examination indicated an IMT. The lesion was removed en bloc under general anesthesia, and the patient manifested no clinical evidence of recurrence for 24 months. Lesions of nonendodontic origin should be included in the differential diagnosis of apical periodontitis. Every available diagnostic tool should be used to confirm the diagnosis. Cone-beam computed tomographic imaging is very helpful for differential diagnosis in IMTs mimicking apical periodontitis. Copyright © 2015 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Methodology Investigation of AI(Artificial Intelligence) Test Officer Support Tool. Volume 1

DTIC Science & Technology

1989-03-01

American Association for Artificial inteligence A! ............. Artificial inteliigence AMC ............ Unt:ed States Army Maeriel Comand ASL...block number) FIELD GROUP SUB-GROUP Artificial Intelligence, Expert Systems Automated Aids to Testing 9. ABSTRACT (Continue on reverse if necessary and...identify by block number) This report covers the application of Artificial Intelligence-Techniques to the problem of creating automated tools to

HSF1 is activated as a consequence of lymphocyte activation and regulates a major proteostasis network in T cells critical for cell division during stress

PubMed Central

Gandhapudi, Siva K.; Murapa, Patience; Threlkeld, Zachary D.; Ward, Martin; Sarge, Kevin D.; Snow, Charles; Woodward, Jerold G.

2013-01-01

Heat Shock Transcription Factor 1 (HSF1) is a major transcriptional regulator of the heat shock response in eukaryotic cells. HSF1 is also evoked in response to a variety of cellular stressors including elevated temperatures, oxidative stress, and other proteotoxic stressors. Previously, we demonstrated that HSF1 is activated in naive T cells at fever range temperatures (39.5°C) and is critical for in vitro T cell proliferation at fever temperatures. In this study, we demonstrated thatmurine HSF1 became activated to the DNA-binding form and trans-activated a large number of genes in lymphoid cells strictly as a consequence of receptor activation in the absence of apparent cellular stress. Microarray analysis comparing HSF1+/+ and HSF1−/− gene expression in T cells activated at 37°C revealed a diverse set of 323 genes significantly regulated by HSF1 in non-stressed T cells. In vivo proliferation studies revealed a significant impairment of HSF1−/− T cell expansion under conditions mimicking a robust immune response (staphylococcal enterotoxin B induced T cell activation). This proliferation defect due to loss of HSF1 is observed even under non-febrile temperatures. HSF1−/− T cells activated at fever temperatures show a dramatic reduction in cyclin E and cyclin A proteins during the cell cycle, although the transcription of these genes was not affected. Finally, B cell, and hematopoietic stem cell proliferation from HSF1−/− mice, but not HSF1+/+ mice were also attenuated under stressful conditions, indicating that HSF1 is critical for the cell cycle progression of lymphoid cells activated under stressful conditions. PMID:24043900

Versatile Three-Dimensional Porous Cu@Cu2 O Aerogel Networks as Electrocatalysts and Mimicking Peroxidases.

PubMed

Ling, Pinghua; Zhang, Qiang; Cao, Tingting; Gao, Feng

2018-06-04

A facile strategy is presented to form 3D porous Cu@Cu 2 O aerogel networks by self-assembling Cu@Cu 2 O nanoparticles with the diameters of ca. 40 nm for constructing catalytic interfaces. Unexpectedly, the prepared Cu@Cu 2 O aerogel networks display excellent electrocatalytic activity to glucose oxidation at a low onset potential of ca. 0.25 V. Moreover, the Cu@Cu 2 O aerogels also can act as mimicking-enzymes including horseradish peroxidase and NADH peroxidase, and show obvious enzymatic catalytic activities to the oxidation of dopamine (DA), o-phenyldiamine (OPD), 3,3,5,5-tetramethylbenzidine (TMB), and dihydronicotinamide adenine dinucleotide (NADH) in the presence of H 2 O 2 . These 3D Cu@Cu 2 O aerogel networks are a new class of porous catalytic materials as mimic peroxidases and electrocatalysts and offer a novel platform to construct catalytic interfaces for promising applications in electrochemical sensors and artificial enzymatic catalytic systems. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

A new quadrature annular resonator for 3 T MRI based on artificial-dielectrics

NASA Astrophysics Data System (ADS)

Mikhailovskaya, Anna A.; Shchelokova, Alena V.; Dobrykh, Dmitry A.; Sushkov, Ivan V.; Slobozhanyuk, Alexey P.; Webb, Andrew

2018-06-01

Dielectric resonators have previously been constructed for ultra-high frequency magnetic resonance imaging and microscopy. However, it is challenging to design these dielectric resonators at clinical field strengths due to their intrinsically large dimensions, especially when using materials with moderate permittivity. Here we propose and characterize a novel approach using artificial-dielectrics which reduces substantially the required outer diameter of the resonator. For a resonator designed to operate in a 3 Tesla scanner using water as the dielectric, a reduction in outer diameter of 37% was achieved. When used in an inductively-coupled wireless mode, the sensitivity of the artificial-dielectric resonator was measured to be slightly higher than that of a standard dielectric resonator operating in its degenerate circularly-polarized hybrid electromagnetic modes (HEM11). This study demonstrates the first application of an artificial-dielectric approach to MR volume coil design.

A defect in KCa3.1 channel activity limits the ability of CD8+ T cells from cancer patients to infiltrate an adenosine-rich microenvironment.

PubMed

Chimote, Ameet A; Balajthy, Andras; Arnold, Michael J; Newton, Hannah S; Hajdu, Peter; Qualtieri, Julianne; Wise-Draper, Trisha; Conforti, Laura

2018-04-24

The limited ability of cytotoxic T cells to infiltrate solid tumors hampers immune surveillance and the efficacy of immunotherapies in cancer. Adenosine accumulates in solid tumors and inhibits tumor-specific T cells. Adenosine inhibits T cell motility through the A 2A receptor (A 2A R) and suppression of KCa3.1 channels. We conducted three-dimensional chemotaxis experiments to elucidate the effect of adenosine on the migration of peripheral blood CD8 + T cells from head and neck squamous cell carcinoma (HNSCC) patients. The chemotaxis of HNSCC CD8 + T cells was reduced in the presence of adenosine, and the effect was greater on HNSCC CD8 + T cells than on healthy donor (HD) CD8 + T cells. This response correlated with the inability of CD8 + T cells to infiltrate tumors. The effect of adenosine was mimicked by an A 2A R agonist and prevented by an A 2A R antagonist. We found no differences in A 2A R expression, 3',5'-cyclic adenosine monophosphate abundance, or protein kinase A type 1 activity between HNSCC and HD CD8 + T cells. We instead detected a decrease in KCa3.1 channel activity, but not expression, in HNSCC CD8 + T cells. Activation of KCa3.1 channels by 1-EBIO restored the ability of HNSCC CD8 + T cells to chemotax in the presence of adenosine. Our data highlight the mechanism underlying the increased sensitivity of HNSCC CD8 + T cells to adenosine and the potential therapeutic benefit of KCa3.1 channel activators, which could increase infiltration of these T cells into tumors. Copyright © 2018 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

Dectin-1 diversifies Aspergillus fumigatus–specific T cell responses by inhibiting T helper type 1 CD4 T cell differentiation

PubMed Central

Hohl, Tobias M.; Collins, Nichole; Leiner, Ingrid; Gallegos, Alena; Saijo, Shinobu; Coward, Jesse W.; Iwakura, Yoichiro

2011-01-01

Pulmonary infection of mice with Aspergillus fumigatus induces concurrent T helper type 1 (Th1) and Th17 responses that depend on Toll-like receptor/MyD88 and Dectin-1, respectively. However, the mechanisms balancing Th1 and Th17 CD4 T cell populations during infection remain incompletely defined. In this study, we show that Dectin-1 deficiency disproportionally increases Th1 responses and decreases Th17 differentiation after A. fumigatus infection. Dectin-1 signaling in A. fumigatus–infected wild-type mice reduces IFN-γ and IL-12p40 expression in the lung, thereby decreasing T-bet expression in responding CD4 T cells and enhancing Th17 responses. Absence of IFN-γ or IL-12p35 in infected mice or T-bet in responding CD4 T cells enhances Th17 differentiation, independent of Dectin-1 expression, in A. fumigatus–infected mice. Transient deletion of monocyte-derived dendritic cells also reduces Th1 and boosts Th17 differentiation of A. fumigatus–specific CD4 T cells. Our findings indicate that Dectin-1–mediated signals alter CD4 T cell responses to fungal infection by decreasing the production of IL-12 and IFN-γ in innate cells, thereby decreasing T-bet expression in A. fumigatus–specific CD4 T cells and enabling Th17 differentiation. PMID:21242294

Interaction driven quantum Hall effect in artificially stacked graphene bilayers

PubMed Central

Iqbal, Muhammad Zahir; Iqbal, Muhammad Waqas; Siddique, Salma; Khan, Muhammad Farooq; Ramay, Shahid Mahmood; Nam, Jungtae; Kim, Keun Soo; Eom, Jonghwa

2016-01-01

The honeycomb lattice structure of graphene gives rise to its exceptional electronic properties of linear dispersion relation and its chiral nature of charge carriers. The exceptional electronic properties of graphene stem from linear dispersion relation and chiral nature of charge carries, originating from its honeycomb lattice structure. Here, we address the quantum Hall effect in artificially stacked graphene bilayers and single layer graphene grown by chemical vapor deposition. The quantum Hall plateaus started to appear more than 3 T and became clearer at higher magnetic fields up to 9 T. Shubnikov-de Hass oscillations were manifestly observed in graphene bilayers texture. These unusual plateaus may have been due to the layers interaction in artificially stacked graphene bilayers. Our study initiates the understanding of interactions between artificially stacked graphene layers. PMID:27098387

Interaction driven quantum Hall effect in artificially stacked graphene bilayers.

PubMed

Iqbal, Muhammad Zahir; Iqbal, Muhammad Waqas; Siddique, Salma; Khan, Muhammad Farooq; Ramay, Shahid Mahmood; Nam, Jungtae; Kim, Keun Soo; Eom, Jonghwa

2016-04-21

The honeycomb lattice structure of graphene gives rise to its exceptional electronic properties of linear dispersion relation and its chiral nature of charge carriers. The exceptional electronic properties of graphene stem from linear dispersion relation and chiral nature of charge carries, originating from its honeycomb lattice structure. Here, we address the quantum Hall effect in artificially stacked graphene bilayers and single layer graphene grown by chemical vapor deposition. The quantum Hall plateaus started to appear more than 3 T and became clearer at higher magnetic fields up to 9 T. Shubnikov-de Hass oscillations were manifestly observed in graphene bilayers texture. These unusual plateaus may have been due to the layers interaction in artificially stacked graphene bilayers. Our study initiates the understanding of interactions between artificially stacked graphene layers.

Ultra-low field T1 vs. T1rho at 3T and 7T: study of rotationally immobilized protein gels and animal brain tissues

NASA Astrophysics Data System (ADS)

Dong, Hui; Inglis, Ben; Barr, Ian; Clarke, John

2015-03-01

Clinical magnetic resonance imaging (MRI) machines operating in static fields of typically 1.5 T or 3 T can capture information on slow molecular dynamics utilizing the so-called T1rho technique. This technique, in which a radiofrequency (RF) spin-lock field is applied with microtesla amplitude, has been used, for example, to determine the onset time of stroke in studies on rats. The long RF pulse, however, may exceed the specific absorption rate (SAR) limit, putting subjects at risk. Ultra-low-field (ULF) MRI, based on Superconducting Quantum Interference Devices (SQUIDs), directly detects proton signals at a static magnetic field of typically 50-250 μT. Using our ULF MRI system with adjustable static field of typically 55 to 240 μT, we systematically measured the T1 and T2 dispersion profiles of rotationally immobilized protein gels (bovine serum albumin), ex vivo pig brains, and ex vivo rat brains with induced stroke. Comparing the ULF results with T1rho dispersion obtained at 3 T and 7 T, we find that the degree of protein immobilization determines the frequency-dependence of both T1 and T1rho. Furthermore, T1rho and ULF T1 show similar results for stroke, suggesting that ULF MRI may be used to image traumatic brain injury with negligible SAR. This research was supported by the Henry H. Wheeler, Jr. Brain Imaging Center and the Donaldson Trust.

Deep Granuloma Annulare Mimicking Inflamed Cysts in a Teenager.

PubMed

Guo, Emily L; Degesys, Catherine A; Jahan-Tigh, Richard; Chan, Audrey

2017-07-01

We describe deep granuloma annulare (DGA) of the forehead mimicking inflamed cysts. Reactive inflammation and sterile purulent drainage may be an underrecognized feature of DGA. © 2017 Wiley Periodicals, Inc.

Optimum selection of an implantable secondary battery for an artificial heart by examination of the cycle life test.

PubMed

Okamoto, Eiji; Watanabe, Kazuya; Hashiba, Kunihiro; Inoue, Taku; Iwazawa, Eichi; Momoi, Masato; Hashimoto, Takuya; Mitamura, Yoshinori

2002-01-01

An implantable secondary battery is one of the key components in a total artificial heart system. Because a 2 year cycle life is required, the cycle life of the secondary battery as well as its charge and discharge properties are important parameters for selection of an appropriate battery. We carried out cycle life tests on four kinds of rechargeable batteries (a Ni-MH secondary battery, a Ni-Cd secondary battery, a Li-ion battery with a graphite anode, and a Li-ion battery with a nongraphitizable carbon electrode) to determine their suitability as implanted back-up batteries. Each of the batteries was charge/discharge cycled at 37 degrees C to 39 degrees C using a charge current of 1 C ampere, and they were each fully discharged under either pulsatile discharge loads, which mimicked pulsatile operation, or a nonpulsatile load equivalent to the average of the pulsatile loads. The two Li-ion batteries made by different manufacturers both met the minimum requirement of cycle life of more than 1,500 cycles, considering safety coefficient regardless of the discharge pattern. In addition, the temperature increase of these Li-ion batteries (3 degrees C) was lower than that of Ni-Cd and Ni-MH batteries (15-25 degrees C). Out of these four batteries, the two Li-ion batteries are the most suitable for use in a totally implantable artificial heart system.

Local T1-T2 distribution measurements in porous media

NASA Astrophysics Data System (ADS)

Vashaee, S.; Li, M.; Newling, B.; MacMillan, B.; Marica, F.; Kwak, H. T.; Gao, J.; Al-harbi, A. M.; Balcom, B. J.

2018-02-01

A novel slice-selective T1-T2 measurement is proposed to measure spatially resolved T1-T2 distributions. An adiabatic inversion pulse is employed for slice-selection. The slice-selective pulse is able to select a quasi-rectangular slice, on the order of 1 mm, at an arbitrary position within the sample. The method does not employ conventional selective excitation in which selective excitation is often accomplished by rotation of the longitudinal magnetization in the slice of interest into the transverse plane, but rather a subtraction based on CPMG data acquired with and without adiabatic inversion slice selection. T1 weighting is introduced during recovery from the inversion associated with slice selection. The local T1-T2 distributions measured are of similar quality to bulk T1-T2 measurements. The new method can be employed to characterize oil-water mixtures and other fluids in porous media. The method is beneficial when a coarse spatial distribution of the components is of interest.

Controlling electric and magnetic currents in artificial spin ice (Presentation Recording)

NASA Astrophysics Data System (ADS)

Branford, Will R.

2015-09-01

I will discuss the collective properties of arrays of single domain nanomagnets called Artificial Spin Ice.1 The shape of each nanomagnet controls the magnetic anisotropy and the elements are closely spaced so dipolar interactions are important. The honeycomb lattice geometry prevents the satisfaction of all dipole interactions. Here I will show direct magnetic imaging studies of magnetic charge flow.2 The magnetic charge is carried by transverse domain walls and the chirality of the domain wall is found to control the direction of propagation.3,4 Injection of domain walls within the arrays with local fields is also explored.5 References 1 Branford, W. R., Ladak, S., Read, D. E., Zeissler, K. and Cohen, L. F. Emerging Chirality in Artificial Spin Ice. Science 335, 1597-1600, (2012). 2 Ladak, S., Read, D. E., Perkins, G. K., Cohen, L. F. and Branford, W. R. Direct observation of magnetic monopole defects in an artificial spin-ice system. Nature Physics 6, 359-363, (2010). 3 Burn, D. M., Chadha, M., Walton, S. K. and Branford, W. R. Dynamic interaction between domain walls and nanowire vertices. Phys. Rev. B 90, 144414, (2014). 4 Zeissler, K., Walton, S. K., Ladak, S., Read, D. E., Tyliszczak, T., Cohen, L. F. and Branford, W. R. The non-random walk of chiral magnetic charge carriers in artificial spin ice. Sci Rep-Uk 3, 1252, (2013). 5 Pushp, A., Phung, T., Rettner, C., Hughes, B. P., Yang, S. H., Thomas, L. and Parkin, S. S. P. Domain wall trajectory determined by its fractional topological edge defects. Nature Physics 9, 505-511, (2013).

Exquisite Enzyme-Fenton Biomimetic Catalysts for Hydroxyl Radical Production by Mimicking an Enzyme Cascade.

PubMed

Zhang, Qi; Chen, Shuo; Wang, Hua; Yu, Hongtao

2018-03-14

Hydrogen peroxide (H 2 O 2 ) is a key reactant in the Fenton process. As a byproduct of enzymatic reaction, H 2 O 2 can be obtained via catalytical oxidation of glucose using glucose oxidase in the presence of O 2 . Another oxidation product (gluconic acid) can suitably adjust the microenvironmental pH contributing to the Fe 3+ /Fe 2+ cycle in the Fenton reaction. Enzymes are extremely efficient at catalyzing a variety of reactions with high catalytic activity, substrate specificity, and yields in living organisms. Inspired by the multiple functions of natural multienzyme systems, an exquisite nanozyme-modified α-FeOOH/porous carbon (PC) biomimetic catalyst constructed by in situ growth of glucose oxidase-mimicking Au nanoparticles and crystallization of adsorbed ferric ions within carboxyl into hierarchically PC is developed as an efficient enzyme-Fenton catalyst. The products (H 2 O 2 , ∼4.07 mmol·L -1 ) of the first enzymatic reaction are immediately used as substrates for the second Fenton-like reaction to generate the valuable • OH (∼96.84 μmol·L -1 ), thus mimicking an enzyme cascade pathway. α-FeOOH nanocrystals, attached by C-O-Fe bondings, are encapsulated into the mesoporous PC frameworks, facilitating the electron transfer between α-FeOOH and the PC support and greatly suppressing iron leaching. This study paves a new avenue for designing biomimetic enzyme-based Fenton catalysts mimicking a natural system for • OH production.

Spontaneous motor entrainment to music in multiple vocal mimicking species.

PubMed

Schachner, Adena; Brady, Timothy F; Pepperberg, Irene M; Hauser, Marc D

2009-05-26

The human capacity for music consists of certain core phenomena, including the tendency to entrain, or align movement, to an external auditory pulse [1-3]. This ability, fundamental both for music production and for coordinated dance, has been repeatedly highlighted as uniquely human [4-11]. However, it has recently been hypothesized that entrainment evolved as a by-product of vocal mimicry, generating the strong prediction that only vocal mimicking animals may be able to entrain [12, 13]. Here we provide comparative data demonstrating the existence of two proficient vocal mimicking nonhuman animals (parrots) that entrain to music, spontaneously producing synchronized movements resembling human dance. We also provide an extensive comparative data set from a global video database systematically analyzed for evidence of entrainment in hundreds of species both capable and incapable of vocal mimicry. Despite the higher representation of vocal nonmimics in the database and comparable exposure of mimics and nonmimics to humans and music, only vocal mimics showed evidence of entrainment. We conclude that entrainment is not unique to humans and that the distribution of entrainment across species supports the hypothesis that entrainment evolved as a by-product of selection for vocal mimicry.

Leaf-architectured 3D Hierarchical Artificial Photosynthetic System of Perovskite Titanates Towards CO2 Photoreduction Into Hydrocarbon Fuels

PubMed Central

Zhou, Han; Guo, Jianjun; Li, Peng; Fan, Tongxiang; Zhang, Di; Ye, Jinhua

2013-01-01

The development of an “artificial photosynthetic system” (APS) having both the analogous important structural elements and reaction features of photosynthesis to achieve solar-driven water splitting and CO2 reduction is highly challenging. Here, we demonstrate a design strategy for a promising 3D APS architecture as an efficient mass flow/light harvesting network relying on the morphological replacement of a concept prototype-leaf's 3D architecture into perovskite titanates for CO2 photoreduction into hydrocarbon fuels (CO and CH4). The process uses artificial sunlight as the energy source, water as an electron donor and CO2 as the carbon source, mimicking what real leaves do. To our knowledge this is the first example utilizing biological systems as “architecture-directing agents” for APS towards CO2 photoreduction, which hints at a more general principle for APS architectures with a great variety of optimized biological geometries. This research would have great significance for the potential realization of global carbon neutral cycle. PMID:23588925

Improved Pharmacological and Structural Properties of HIV Fusion Inhibitor AP 3 over Enfuvirtide: Highlighting Advantages of Artificial Peptide Strategy

DOE PAGES

Zhu, Xiaojie; Zhu, Yun; Ye, Sheng; ...

2015-08-19

Enfuvirtide (T20), is the first HIV fusion inhibitor approved for treatment of HIV/AIDS patients who fail to respond to the current antiretroviral drugs. However, its clinical application is limited because of short half-life, drug resistance and cross-reactivity with the preexisting antibodies in HIV-infected patients. Using an artificial peptide strategy, we designed a peptide with non-native protein sequence, AP 3, which exhibited potent antiviral activity against a broad spectrum of HIV-1 strains, including those resistant to T20, and had remarkably longer in vivo half-life than T20. While the preexisting antibodies in HIV-infected patients significantly suppressed T20’s antiviral activity, these antibodies neithermore » recognized AP 3, nor attenuated its anti-HIV-1 activity. Structurally different from T20, AP 3 could fold into single-helix and interact with gp41 NHR. The two residues, Met and Thr, at the N-terminus of AP 3 form a hook-like structure to stabilize interaction between AP 3 and NHR helices. Therefore, AP 3 has potential for further development as a new HIV fusion inhibitor with improved antiviral efficacy, resistance profile and pharmacological properties over enfuvirtide. Meanwhile, this study highlighted the advantages of artificially designed peptides, and confirmed that this strategy could be used in developing artificial peptide-based viral fusion inhibitors against HIV and other enveloped viruses.« less

Improved Pharmacological and Structural Properties of HIV Fusion Inhibitor AP 3 over Enfuvirtide: Highlighting Advantages of Artificial Peptide Strategy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhu, Xiaojie; Zhu, Yun; Ye, Sheng

Enfuvirtide (T20), is the first HIV fusion inhibitor approved for treatment of HIV/AIDS patients who fail to respond to the current antiretroviral drugs. However, its clinical application is limited because of short half-life, drug resistance and cross-reactivity with the preexisting antibodies in HIV-infected patients. Using an artificial peptide strategy, we designed a peptide with non-native protein sequence, AP 3, which exhibited potent antiviral activity against a broad spectrum of HIV-1 strains, including those resistant to T20, and had remarkably longer in vivo half-life than T20. While the preexisting antibodies in HIV-infected patients significantly suppressed T20’s antiviral activity, these antibodies neithermore » recognized AP 3, nor attenuated its anti-HIV-1 activity. Structurally different from T20, AP 3 could fold into single-helix and interact with gp41 NHR. The two residues, Met and Thr, at the N-terminus of AP 3 form a hook-like structure to stabilize interaction between AP 3 and NHR helices. Therefore, AP 3 has potential for further development as a new HIV fusion inhibitor with improved antiviral efficacy, resistance profile and pharmacological properties over enfuvirtide. Meanwhile, this study highlighted the advantages of artificially designed peptides, and confirmed that this strategy could be used in developing artificial peptide-based viral fusion inhibitors against HIV and other enveloped viruses.« less

Multi-modality gellan gum-based tissue-mimicking phantom with targeted mechanical, electrical, and thermal properties.

PubMed

Chen, Roland K; Shih, A J

2013-08-21

This study develops a new class of gellan gum-based tissue-mimicking phantom material and a model to predict and control the elastic modulus, thermal conductivity, and electrical conductivity by adjusting the mass fractions of gellan gum, propylene glycol, and sodium chloride, respectively. One of the advantages of gellan gum is its gelling efficiency allowing highly regulable mechanical properties (elastic modulus, toughness, etc). An experiment was performed on 16 gellan gum-based tissue-mimicking phantoms and a regression model was fit to quantitatively predict three material properties (elastic modulus, thermal conductivity, and electrical conductivity) based on the phantom material's composition. Based on these material properties and the regression model developed, tissue-mimicking phantoms of porcine spinal cord and liver were formulated. These gellan gum tissue-mimicking phantoms have the mechanical, thermal, and electrical properties approximately equivalent to those of the spinal cord and the liver.

A Difference Scheme with Autocontrol Artificial Viscosity to Predict Ablated Nosetip Shape

DTIC Science & Technology

1989-09-29

I FTD-ID(RS)T-0640-89 U) (0 FOREIGN TECHNOLOGY DIVISION A DIFFERENCE SCHEME WITH AUTOCONTROL ARTIFICIAL VISCOSITY TO PREDICT ABLATED NOSETIP SHAPE by...September 1989 MICROFICHE NR: FTD-89-C-000800 A DIFFERENCE SCHEME WITH AUTOCONTROL ARTIFICIAL VISCOSITY TO PREDICT ABLATED NOSETIP SHAPE By: Yang Maozhao...DIFFERENCE SCHEME WITH AUTOCONTROL ARTIFICIAL VISCOSITY TO PREDICT ABLATED NOSETIP SHAPE Yang Maozhao (China Aerodynamic Research and Development Centre

From natural to artificial photosynthesis

PubMed Central

Barber, James; Tran, Phong D.

2013-01-01

Demand for energy is projected to increase at least twofold by mid-century relative to the present global consumption because of predicted population and economic growth. This demand could be met, in principle, from fossil energy resources, particularly coal. However, the cumulative nature of carbon dioxide (CO2) emissions demands that stabilizing the atmospheric CO2 levels to just twice their pre-anthropogenic values by mid-century will be extremely challenging, requiring invention, development and deployment of schemes for carbon-neutral energy production on a scale commensurate with, or larger than, the entire present-day energy supply from all sources combined. Among renewable and exploitable energy resources, nuclear fusion energy or solar energy are by far the largest. However, in both cases, technological breakthroughs are required with nuclear fusion being very difficult, if not impossible on the scale required. On the other hand, 1 h of sunlight falling on our planet is equivalent to all the energy consumed by humans in an entire year. If solar energy is to be a major primary energy source, then it must be stored and despatched on demand to the end user. An especially attractive approach is to store solar energy in the form of chemical bonds as occurs in natural photosynthesis. However, a technology is needed which has a year-round average conversion efficiency significantly higher than currently available by natural photosynthesis so as to reduce land-area requirements and to be independent of food production. Therefore, the scientific challenge is to construct an ‘artificial leaf’ able to efficiently capture and convert solar energy and then store it in the form of chemical bonds of a high-energy density fuel such as hydrogen while at the same time producing oxygen from water. Realistically, the efficiency target for such a technology must be 10 per cent or better. Here, we review the molecular details of the energy capturing reactions of natural

From natural to artificial photosynthesis.

PubMed

Barber, James; Tran, Phong D

2013-04-06

Demand for energy is projected to increase at least twofold by mid-century relative to the present global consumption because of predicted population and economic growth. This demand could be met, in principle, from fossil energy resources, particularly coal. However, the cumulative nature of carbon dioxide (CO(2)) emissions demands that stabilizing the atmospheric CO(2) levels to just twice their pre-anthropogenic values by mid-century will be extremely challenging, requiring invention, development and deployment of schemes for carbon-neutral energy production on a scale commensurate with, or larger than, the entire present-day energy supply from all sources combined. Among renewable and exploitable energy resources, nuclear fusion energy or solar energy are by far the largest. However, in both cases, technological breakthroughs are required with nuclear fusion being very difficult, if not impossible on the scale required. On the other hand, 1 h of sunlight falling on our planet is equivalent to all the energy consumed by humans in an entire year. If solar energy is to be a major primary energy source, then it must be stored and despatched on demand to the end user. An especially attractive approach is to store solar energy in the form of chemical bonds as occurs in natural photosynthesis. However, a technology is needed which has a year-round average conversion efficiency significantly higher than currently available by natural photosynthesis so as to reduce land-area requirements and to be independent of food production. Therefore, the scientific challenge is to construct an 'artificial leaf' able to efficiently capture and convert solar energy and then store it in the form of chemical bonds of a high-energy density fuel such as hydrogen while at the same time producing oxygen from water. Realistically, the efficiency target for such a technology must be 10 per cent or better. Here, we review the molecular details of the energy capturing reactions of natural

A robust and tunable mitotic oscillator in artificial cells

PubMed Central

Wang, Shiyuan; Barnes, Patrick M; Liu, Xuwen; Xu, Haotian; Jin, Minjun; Liu, Allen P

2018-01-01

Single-cell analysis is pivotal to deciphering complex phenomena like heterogeneity, bistability, and asynchronous oscillations, where a population ensemble cannot represent individual behaviors. Bulk cell-free systems, despite having unique advantages of manipulation and characterization of biochemical networks, lack the essential single-cell information to understand a class of out-of-steady-state dynamics including cell cycles. Here, by encapsulating Xenopus egg extracts in water-in-oil microemulsions, we developed artificial cells that are adjustable in sizes and periods, sustain mitotic oscillations for over 30 cycles, and function in forms from the simplest cytoplasmic-only to the more complicated ones involving nuclear dynamics, mimicking real cells. Such innate flexibility and robustness make it key to studying clock properties like tunability and stochasticity. Our results also highlight energy as an important regulator of cell cycles. We demonstrate a simple, powerful, and likely generalizable strategy of integrating strengths of single-cell approaches into conventional in vitro systems to study complex clock functions. PMID:29620527

Suprarenal solitary fibrous tumor associated with a NF1 gene mutation mimicking a kidney neoplasm: implications for surgical management

PubMed Central

2014-01-01

Solitary fibrous tumor (SFT) is a rare spindle cell neoplasm, usually occurring in the pleura. Pararenal SFT, mimicking an adrenal gland or renal tumor, as here described, is extremely rare. We report a case of a right suprarenal SFT, incidentally discovered by abdominal ultrasound in a 54-year-old woman carrying a point neurofibromatosis 1 (NF1) gene mutation. Preoperative diagnostic work-up was ineffective in evaluating its origin, and an open radical right nephrectomy was therefore undertaken. Immunohistochemical assay showed a positivity for CD34, CD99 and Bcl-2, so suggesting a diagnosis of SFT. According to our knowledge, the association between this type of tumor and NF1 gene mutation has never been described. In cases of pararenal tumors, a more detailed preoperative diagnosis could be useful to better plan the extension of resection, allowing, in selected cases, nephron-sparing surgery. More studies are needed to better analyze the relationship between NF1 gene mutation and SFT. PMID:24708790

Don’t get caught out! A rare case of a calcified urachal remnant mimicking a bladder calculus

PubMed Central

Rodrigues, Jonathan Carl Luis; Gandhi, Sanjay

2013-01-01

Computer tomography through the kidneys, ureters and bladder (CT KUB) is the mainstay investigation of suspected renal tract calculi. However, several pathologies other than renal tract calculi can cause apparent urinary bladder calcification. We describe the case of a 45 year old man who presented with left sided renal colic. Prone CT KUB performed on admission revealed a calcified urachal remnant mimicking a urinary bladder calculus in the dependent portion of the urinary bladder, confirmed by reviewing the multi-planar reformatted images. This is the first reported case in the literature of this phenomenon. We discuss the importance of using multi-planar reformatted images (MPR) and maximum intensity projection images (MIP), as well as careful review of previous imaging, in making the correct diagnosis. We also discuss the differential diagnoses that should be considered when presented with urinary bladder calcification. PMID:23705044

Evidence of sustained populations of a small reef fish on artificial structures. Does depth affect production on artificial reefs?

PubMed

Fowler, A M; Booth, D J

2012-03-01

The length frequencies and age structures of resident Pseudanthias rubrizonatus (n = 407), a small protogynous serranid, were measured at four isolated artificial structures on the continental shelf of north-western Australia between June and August 2008, to determine whether these structures supported full (complete size and age-structured) populations of this species. The artificial structures were located in depths between 82 and 135 m, and growth rates of juveniles and adults, and body condition of adults, were compared among structures to determine the effect of depth on potential production. All life-history stages, including recently settled juveniles, females and terminal males, of P. rubrizonatus were caught, ranging in standard length (L(s)) from 16·9 to 96·5 mm. Presumed ages estimated from whole and sectioned otoliths ranged between 22 days and 5 years, and parameter ±s.e. estimates of the von Bertalanffy growth model were L(∞) = 152 ± 34 mm, k = 0·15(±0·05) and t(0) = -1·15(±0·15). Estimated annual growth rates were similar between shallow and deep artificial structures; however, otolith lengths and recent growth of juveniles differed among individual structures, irrespective of depth. The artificial structures therefore sustained full populations of P. rubrizonatus, from recently settled juveniles through to adults; however, confirmation of the maximum age attainable for the species is required from natural populations. Depth placement of artificial reefs may not affect the production of fish species with naturally wide depth ranges. © 2012 The Authors. Journal of Fish Biology © 2012 The Fisheries Society of the British Isles.

Tension pneumocephalus mimicking septic shock: a case report.

PubMed

Miranda, Caroline; Mahta, Ali; Wheeler, Lee Adam; Tsiouris, A John; Kamel, Hooman

2018-02-01

Tension pneumocephalus can lead to rapid neurologic deterioration. We report for the first time its association with aseptic systemic inflammatory response syndrome mimicking septic shock and the efficacy of prompt neurosurgical intervention and critical care support in treating this condition. A 64-year-old man underwent 2-stage olfactory groove meningioma resection. The patient developed altered mental status and gait instability on postoperative day 6. Imaging showed significant pneumocephalus. The patient subsequently developed worsening mental status, respiratory failure, and profound shock requiring multiple vasopressors. Bedside needle decompression, identification and repair of the cranial fossa defect, and critical care support led to improved mental status and reversal of shock and multiorgan dysfunction. Thorough evaluation revealed no evidence of an underlying infection. In this case, tension pneumocephalus incited an aseptic systemic inflammatory response syndrome mimicking septic shock. Prompt neurosurgical correction of pneumocephalus and critical care support not only improved neurologic status, but also reversed shock. Such a complication indicates the importance of close monitoring of patients with progressive pneumocephalus.

Cerebello-cortical network fingerprints differ between essential, Parkinson's and mimicked tremors.

PubMed

Muthuraman, Muthuraman; Raethjen, Jan; Koirala, Nabin; Anwar, Abdul Rauf; Mideksa, Kidist G; Elble, Rodger; Groppa, Sergiu; Deuschl, Günter

2018-06-01

Cerebello-thalamo-cortical loops play a major role in the emergence of pathological tremors and voluntary rhythmic movements. It is unclear whether these loops differ anatomically or functionally in different types of tremor. We compared age- and sex-matched groups of patients with Parkinson's disease or essential tremor and healthy controls (n = 34 per group). High-density 256-channel EEG and multi-channel EMG from extensor and flexor muscles of both wrists were recorded simultaneously while extending the hands against gravity with the forearms supported. Tremor was thereby recorded from patients, and voluntarily mimicked tremor was recorded from healthy controls. Tomographic maps of EEG-EMG coherence were constructed using a beamformer algorithm coherent source analysis. The direction and strength of information flow between different coherent sources were estimated using time-resolved partial-directed coherence analyses. Tremor severity and motor performance measures were correlated with connection strengths between coherent sources. The topography of oscillatory coherent sources in the cerebellum differed significantly among the three groups, but the cortical sources in the primary sensorimotor region and premotor cortex were not significantly different. The cerebellar and cortical source combinations matched well with known cerebello-thalamo-cortical connections derived from functional MRI resting state analyses according to the Buckner-atlas. The cerebellar sources for Parkinson's tremor and essential tremor mapped primarily to primary sensorimotor cortex, but the cerebellar source for mimicked tremor mapped primarily to premotor cortex. Time-resolved partial-directed coherence analyses revealed activity flow mainly from cerebellum to sensorimotor cortex in Parkinson's tremor and essential tremor and mainly from cerebral cortex to cerebellum in mimicked tremor. EMG oscillation flowed mainly to the cerebellum in mimicked tremor, but oscillation flowed mainly

The interplay of T1- and T2-relaxation on T1-weighted MRI of hMSCs induced by Gd-DOTA-peptides.

PubMed

Cao, Limin; Li, Binbin; Yi, Peiwei; Zhang, Hailu; Dai, Jianwu; Tan, Bo; Deng, Zongwu

2014-04-01

Three Gd-DOTA-peptide complexes with different peptide sequence are synthesized and used as T1 contrast agent to label human mesenchymal stem cells (hMSCs) for magnetic resonance imaging study. The peptides include a universal cell penetrating peptide TAT, a linear MSC-specific peptide EM7, and a cyclic MSC-specific peptide CC9. A significant difference in labeling efficacy is observed between the Gd-DOTA-peptides as well as a control Dotarem. All Gd-DOTA-peptides as well as Dotarem induce significant increase in T1 relaxation rate which is in favor of T1-weighted MR imaging. Gd-DOTA-CC9 yields the maximum labeling efficacy but poor T1 contrast enhancement. Gd-DOTA-EM7 yields the minimum labeling efficacy but better T1 contrast enhancement. Gd-DOTA-TAT yields a similar labeling efficacy as Gd-DOTA-CC9 and similar T1 contrast enhancement as Gd-DOTA-EM7. The underlying mechanism that governs T1 contrast enhancement effect is discussed. Our results suggest that T1 contrast enhancement induced by Gd-DOTA-peptides depends not only on the introduced cellular Gd content, but more importantly on the effect that Gd-DOTA-peptides exert on the T1-relaxation and T2-relaxation processes/rates. Both T1 and particularly T2 relaxation rate have to be taken into account to interpret T1 contrast enhancement. In addition, the interpretation has to be based on cellular instead of aqueous longitudinal and transverse relaxivities of Gd-DOTA-peptides. Copyright © 2014 Elsevier Ltd. All rights reserved.

Electrocardiogram artifact caused by rigors mimicking narrow complex tachycardia: a case report.

PubMed

Matthias, Anne Thushara; Indrakumar, Jegarajah

2014-02-04

The electrocardiogram (ECG) is useful in the diagnosis of cardiac and non-cardiac conditions. Rigors due to shivering can cause electrocardiogram artifacts mimicking various cardiac rhythm abnormalities. We describe an 80-year-old Sri Lankan man with an abnormal electrocardiogram mimicking narrow complex tachycardia during the immediate post-operative period. Electrocardiogram changes caused by muscle tremor during rigors could mimic a narrow complex tachycardia. Identification of muscle tremor as a cause of electrocardiogram artifact can avoid unnecessary pharmacological and non-pharmacological intervention to prevent arrhythmias.

Estradiol-induced regulation of GLUT4 in 3T3-L1 cells: involvement of ESR1 and AKT activation.

PubMed

Campello, Raquel S; Fátima, Luciana A; Barreto-Andrade, João Nilton; Lucas, Thais F; Mori, Rosana C; Porto, Catarina S; Machado, Ubiratan F

2017-10-01

Impaired insulin-stimulated glucose uptake involves reduced expression of the GLUT4 (solute carrier family 2 facilitated glucose transporter member 4, SLC2A4 gene). 17β-estradiol (E 2 ) modulates SLC2A4 /GLUT4 expression, but the involved mechanisms are unclear. Although E 2 exerts biological effects by binding to estrogen receptors 1/2 (ESR1/2), which are nuclear transcriptional factors; extranuclear effects have also been proposed. We hypothesize that E 2 regulates GLUT4 through an extranuclear ESR1 mechanism. Thus, we investigated the effects of E 2 upon (1) subcellular distribution of ESRs and the proto-oncogene tyrosine-protein kinases (SRC) involvement; (2) serine/threonine-protein kinase (AKT) activation; (3) Slc2a4 /GLUT4 expression and (4) GLUT4 subcellular distribution and glucose uptake in 3T3-L1 adipocytes. Differentiated 3T3-L1 adipocytes were cultivated or not with E 2 for 24 h, and additionally treated or not with ESR1-selective agonist (PPT), ESR1-selective antagonist (MPP) or selective SRC inhibitor (PP2). Subcellular distribution of ESR1, ESR2 and GLUT4 was analyzed by immunocytochemistry; Slc2a4 mRNA and GLUT4 were quantified by qPCR and Western blotting, respectively; plasma membrane GLUT4 translocation and glucose uptake were analyzed under insulin stimulus for 20 min or not. E 2 induced (1) translocation of ESR1, but not of ESR2, from nucleus to plasma membrane and AKT phosphorylation, effects mimicked by PPT and blocked by MPP and PP2; (2) increased Slc2a4 /GLUT4 expression and (3) increased insulin-stimulated GLUT4 translocation and glucose uptake. In conclusion, E 2 treatment promoted a SRC-mediated nucleus-plasma membrane shuttle of ESR1, and increased AKT phosphorylation, Slc2a4 /GLUT4 expression and plasma membrane GLUT4 translocation; consequently, improving insulin-stimulated glucose uptake. These results unravel mechanisms through which estrogen improves insulin sensitivity. © 2017 Society for Endocrinology.

Imaging findings of mimickers of hepatocellular carcinoma

PubMed Central

Lee, Eunchae; Jang, Hyun-Jung

2015-01-01

Radiological imaging plays a crucial role in the diagnosis of hepatocellular carcinoma (HCC) as the noninvasive diagnosis of HCC in high-risk patients by typical imaging findings alone is widely adopted in major practice guidelines for HCC. While imaging techniques have markedly improved in detecting small liver lesions, they often detect incidental benign liver lesions and non-hepatocellular malignancy that can be misdiagnosed as HCC. The most common mimicker of HCC in cirrhotic liver is nontumorous arterioportal shunts that are seen as focal hypervascular liver lesions on dynamic contrast-enhanced cross-sectional imaging. Rapidly enhancing hemangiomas can be easily misdiagnosed as HCC especially on MR imaging with liver-specific contrast agent. Focal inflammatory liver lesions mimic HCC by demonstrating arterial-phase hypervascularity and subsequent washout on dynamic contrast-enhanced imaging. It is important to recognize the suggestive imaging findings for intrahepatic cholangiocarcinoma (CC) as the management of CC is largely different from that of HCC. There are other benign mimickers of HCC such as angiomyolipomas and focal nodular hyperplasia-like nodules. Recognition of their typical imaging findings can reduce false-positive HCC diagnosis. PMID:26770920

Dedifferentiated Liposarcoma Mimicking a Primary Colon Mass.

PubMed

Hollowoa, Blake; Lamps, Laura W; Mizell, Jason S; English, George W; Bridge, Julia A; Ram, Roopa; Gardner, Jerad M

2018-04-01

Dedifferentiated liposarcoma is typically a nonlipogenic high-grade sarcoma that arises from well-differentiated liposarcoma. It most commonly presents as a large mass in the retroperitoneum. Significant involvement of the gastrointestinal tract by dedifferentiated liposarcoma is uncommon. We present a unique case of dedifferentiated liposarcoma radiographically mimicking a primary colon mass with resulting intussusception; stranding of the adjacent adipose tissue was presumed to be a secondary reactive change. On histopathologic analysis of the hemicolectomy specimen, a high-grade sarcoma was seen growing through the colonic wall, and the majority of the surrounding pericolonic adipose tissue was actually composed of well-differentiated liposarcoma with characteristic fibrous bands rather than benign fat with reactive fibrosis. This case raises awareness that well-differentiated liposarcoma and dedifferentiated liposarcoma can rarely present as a primary intestinal mass mimicking colon cancer or other more common entities. When radiographic examination shows a perigastrointestinal or retroperitoneal fatty mass and/or stranding of the fat adjacent to a solid gastrointestinal mass, this unusual scenario should be considered in the radiologic differential diagnosis. Pathologists should keep dedifferentiated liposarcoma in the initial histologic differential diagnosis for any high-grade spindle cell tumor of the retroperitoneum or intra-abdominal visceral organs.

An investigation into the perceptual embodiment of an artificial hand using transcutaneous electrical nerve stimulation (TENS) in intact-limbed individuals.

PubMed

Mulvey, Matthew; Fawkner, Helen; Johnson, Mark I

2014-01-01

Perceptual embodiment of an artificial limb aids manual control of prostheses and can be facilitated by somatosensory feedback. We hypothesised that transcutaneous electrical nerve stimulation (TENS) may facilitate perceptual embodiment of artificial limbs. To determine the effect of TENS on perceptual embodiment of an artificial hand in 32 intact-limbed participants. Participants were exposed to four experimental conditions in four counterbalanced blocks: (i) Vision (V) watching an artificial hand positioned congruently to the real hand (out of view); (ii) Vision and strong non-painful TENS in the real hand (V+T); Vision and Stroking (V+S) of the artificial and real hand with a brush; Vision, Stroking and TENS (V+S+T) watching artificial hand being stroked whilst real hand was stroked and receiving TENS. Repeated measure ANOVA detected effects for Condition (P< 0.001), Block (P< 0.001) and Condition x Block interaction (P< 0.001). Pairwise comparisons detected more intense perceptual embodiment for V+S+T compared with V (P< 0.001) and V+T (P< 0.001), and for V+S compared with V (P< 0.001) and V+T (P< 0.001).The intensity of perceptual embodiment increased for later blocks (P< 0.001). A sensation of TENS was generated within the artificial hand in individuals with intact limbs and this facilitated perceptual embodiment. The magnitude of effect was modest.

Electronic properties of in-plane phase engineered 1T'/2H/1T' MoS2

NASA Astrophysics Data System (ADS)

Thakur, Rajesh; Sharma, Munish; Ahluwalia, P. K.; Sharma, Raman

2018-04-01

We present the first principles studies of semi-infinite phase engineered MoS2 along zigzag direction. The semiconducting (2H) and semi-metallic (1T') phases are known to be stable in thin-film MoS2. We described the electronic and structural properties of the infinite array of 1T'/2H/1T'. It has been found that 1T'phase induced semi-metallic character in 2H phase beyond interface but, only Mo atoms in 2H phase domain contribute to the semi-metallic nature and S atoms towards semiconducting state. 1T'/2H/1T' system can act as a typical n-p-n structure. Also high holes concentration at the interface of Mo layer provides further positive potential barriers.

Peroxidase-Mimicking Nanozyme with Enhanced Activity and High Stability Based on Metal-Support Interactions.

PubMed

Li, Zhihao; Yang, Xiangdong; Yang, Yanbing; Tan, Yaning; He, Yue; Liu, Meng; Liu, Xinwen; Yuan, Quan

2018-01-09

Peroxidase-mimicking nanozymes offer unique advantages in terms of high stability and low cost over natural peroxidase for applications in bioanalysis, biomedicine, and the treatment of pollution. However, the design of high-efficiency peroxidase-mimicking nanozymes remains a great challenge. In this study, we adopted a structural-design approach through hybridization of cube-CeO 2 and Pt nanoparticles to create a new peroxidase-mimicking nanozyme with high efficiency and excellent stability. Relative to pure cube-CeO 2 and Pt nanoparticles, the as-hybridized Pt/cube-CeO 2 nanocomposites display much improved activities because of the strong metal-support interaction. Meanwhile, the nanocomposites also maintain high catalytic activity after long-term storage and multiple recycling. Based on their excellent properties, Pt/cube-CeO 2 nanocomposites were used to construct high-performance colorimetric biosensors for the sensitive detection of metabolites, including H 2 O 2 and glucose. Our findings highlight opportunities for the development of high-efficiency peroxidase-mimicking nanozymes with potential applications such as diagnostics, biomedicine, and the treatment of pollution. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Remineralization of artificial enamel lesions by theobromine.

PubMed

Amaechi, B T; Porteous, N; Ramalingam, K; Mensinkai, P K; Ccahuana Vasquez, R A; Sadeghpour, A; Nakamoto, T

2013-01-01

This study investigated the remineralization potential of theobromine in comparison to a standard NaF dentifrice. Three tooth blocks were produced from each of 30 teeth. Caries-like lesion was created on each block using acidified gel. A smaller block was cut from each block for baseline scanning electron microscopy imaging and electron-dispersive spectroscopy (EDS) analysis for surface Ca level. A tooth slice was cut from each lesion-bearing block for transverse microradiography (TMR) quantification of baseline mineral loss (Δz) and lesion depth (LD). Then baseline surface microhardness (SMH) of each lesion was measured. The three blocks from each tooth were assigned to three remineralizing agents: (1) artificial saliva; (2) artificial saliva with theobromine (0.0011 mol/l), and (3) NaF toothpaste slurry (0.0789 mol/l F). Remineralization was conducted using a pH cycling model with storage in artificial saliva. After a 28-day cycle, samples were analyzed using EDS, TMR, and SMH. Intragroup comparison of pre- and posttest data was performed using t tests (p < 0.05). Intergroup comparisons were performed by post hoc multistep comparisons (Tukey). SMH indicated significant (p < 0.01) remineralization only with theobromine (38 ± 32%) and toothpaste (29 ± 16%). With TMR (Δz/lD), theobromine and toothpaste exhibited significantly (p < 0.01) higher mineral gain relative to artificial saliva. With SMH and TMR, remineralization produced by theobromine and toothpaste was not significantly different. With EDS, calcium deposition was significant in all groups, but not significantly different among the groups (theobromine 13 ± 8%, toothpaste 10 ± 5%, and artificial saliva 6 ± 8%). The present study demonstrated that theobromine in an apatite-forming medium can enhance the remineralization potential of the medium. Copyright © 2013 S. Karger AG, Basel.

A Temporal -omic Study of Propionibacterium freudenreichii CIRM-BIA1T Adaptation Strategies in Conditions Mimicking Cheese Ripening in the Cold

PubMed Central

Dalmasso, Marion; Aubert, Julie; Briard-Bion, Valérie; Chuat, Victoria; Deutsch, Stéphanie-Marie; Even, Sergine; Falentin, Hélène; Jan, Gwénaël; Jardin, Julien; Maillard, Marie-Bernadette; Parayre, Sandrine; Piot, Michel; Tanskanen, Jarna; Thierry, Anne

2012-01-01

Propionibacterium freudenreichii is used as a ripening culture in Swiss cheese manufacture. It grows when cheeses are ripened in a warm room (about 24°C). Cheeses with an acceptable eye formation level are transferred to a cold room (about 4°C), inducing a marked slowdown of propionic fermentation, but P. freudenreichii remains active in the cold. To investigate the P. freudenreichii strategies of adaptation and survival in the cold, we performed the first global gene expression profile for this species. The time-course transcriptomic response of P. freudenreichii CIRM-BIA1T strain was analyzed at five times of incubation, during growth at 30°C then for 9 days at 4°C, under conditions preventing nutrient starvation. Gene expression was also confirmed by RT-qPCR for 28 genes. In addition, proteomic experiments were carried out and the main metabolites were quantified. Microarray analysis revealed that 565 genes (25% of the protein-coding sequences of P. freudenreichii genome) were differentially expressed during transition from 30°C to 4°C (P<0.05 and |fold change|>1). At 4°C, a general slowing down was observed for genes implicated in the cell machinery. On the contrary, P. freudenreichii CIRM-BIA1T strain over-expressed genes involved in lactate, alanine and serine conversion to pyruvate, in gluconeogenesis, and in glycogen synthesis. Interestingly, the expression of different genes involved in the formation of important cheese flavor compounds, remained unchanged at 4°C. This could explain the contribution of P. freudenreichii to cheese ripening even in the cold. In conclusion, P. freudenreichii remains metabolically active at 4°C and induces pathways to maintain its long-term survival. PMID:22253706

Chronic active Epstein-Barr virus infection mimicking Henoch-Schönlein purpura.

PubMed

Guissa, Vanessa R; Aragão, Paula A; Marques, Heloisa H; Jacob, Cristina M; Silva, Clovis A

2010-01-01

Chronic active Epstein-Barr virus (CAEBV) infection is characterized by chronic or recurrent symptoms for at least 3 months, such as fever, hepatosplenomegaly and lymphadenopathy. The diagnosis is established due to the presence of anti-EBV antibodies or isolation of this infectious agent in affected tissues. Three cases of CAEBV infection mimicking Henoch-Schönlein purpura (HSP) were described. CASE 1: Female 3-year old patient with cervical adenomegaly, anemia and fever developed palpable purpura, haematuria and arthritis. CAEBV infection was established by serology test. She received methylprednisolone and acyclovir. She had generalized lymphadenopathy, hepatomegaly, splenomegaly, disseminated intravascular coagulation and deceased. CASE 2: Male 12-year old patient with persistent anemia, lymphadenopathy, hepatomegaly and splenomegaly had CAEBV infection diagnosis by serology test. He developed purpura and arthritis and received methylprednisolone. CASE 3: Male 13-year old patient had purpura, abdominal pain, haematuria, hepatomegaly, splenomegaly, lymphadenopathy, anemia and elevated liver enzymes. The cervical lymph node biopsy was positive to EBV infection. He received methylprednisolone and acyclovir, developing acute fulminant hepatitis and death. CAEBV infection mimicking HSP was rarely observed in our population.

Off-resonance magnetic resonance angiography improves visualization of in-stent lumen in peripheral nitinol stents compared to conventional T1-weighted acquisitions: an in vitro comparison study.

PubMed

Gitsioudis, Gitsios; Fortner, Philipp; Stuber, Matthias; Missiou, Anna; Andre, Florian; Müller, Oliver J; Katus, Hugo A; Korosoglou, Grigorios

2016-11-01

To compare the value of inversion recovery with on-resonant water suppression (IRON) to conventional T1-weighted (T1w) MRA and computed tomography angiography (CTA) for visualization of peripheral nitinol stents. We visualized 14 different peripheral nitinol stents in vitro both using Gadolinium (Gd) and ultrasmall superparamagnetic iron nanoparticles (USPIOs) for conventional T1w and IRON-MRA using clinical grade 1.5T MR scanner and iodinated contrast material for CTA using a 256-slice CT scanner. Parameter assessment included signal- and contrast-to-noise ratio (S/CNR), relative in-stent signal and artificial lumen narrowing. X-ray angiography served as gold standard for diameter assessment. Gd-enhanced IRON-MRA exhibited highest in-stent SNR and CNR values compared to conventional T1w MRA (IRON (Gd/USPIO): SNR = 30 ± 3/21 ± 2, CNR = 23 ± 2/14 ± 1; T1w: SNR = 16 ± 1/14 ± 2, CNR = 12 ± 1/10 ± 1, all p < 0.05). Furthermore, IRON-MRA achieved highest relative in-stent signal both using Gd and USPIO (IRON (Gd/USPIO): 121 ± 8 %/103 ± 6 %; T1w: 73 ± 2 %/66 ± 4 %; CTA: 84 ± 6 %, all p < 0.05). However, artificial lumen narrowing appeared similar in all imaging protocols (IRON (Gd/USPIO): 21 ± 3 %/21 ± 2 %; T1w: 16 ± 4 %/17 ± 3 %; CTA: 19 ± 2 %, all p = NS). Finally, IRON-MRA provided improvement of the in-stent lumen visualization with an 'open-close-open' design, which revealed a complete in-stent signal loss in T1w MRA. IRON-MRA improves in-stent visualization in vitro compared to conventional T1w MRA and CTA. In light of the in vitro results with Gd-enhanced IRON-MRA, the clinical implementation of such an approach appears promising.

Simultaneous acquisition for T2 -T2 Exchange and T1 -T2 correlation NMR experiments

NASA Astrophysics Data System (ADS)

Montrazi, Elton T.; Lucas-Oliveira, Everton; Araujo-Ferreira, Arthur G.; Barsi-Andreeta, Mariane; Bonagamba, Tito J.

2018-04-01

The NMR measurements of longitudinal and transverse relaxation times and its multidimensional correlations provide useful information about molecular dynamics. However, these experiments are very time-consuming, and many researchers proposed faster experiments to reduce this issue. This paper presents a new way to simultaneously perform T2 -T2 Exchange and T1 -T2 correlation experiments by taking the advantage of the storage time and the two steps phase cycling used for running the relaxation exchange experiment. The data corresponding to each step is either summed or subtracted to produce the T2 -T2 and T1 -T2 data, enhancing the information obtained while maintaining the experiment duration. Comparing the results from this technique with traditional NMR experiments it was possible to validate the method.

A new quadrature annular resonator for 3 T MRI based on artificial-dielectrics.

PubMed

Mikhailovskaya, Anna A; Shchelokova, Alena V; Dobrykh, Dmitry A; Sushkov, Ivan V; Slobozhanyuk, Alexey P; Webb, Andrew

2018-06-01

Dielectric resonators have previously been constructed for ultra-high frequency magnetic resonance imaging and microscopy. However, it is challenging to design these dielectric resonators at clinical field strengths due to their intrinsically large dimensions, especially when using materials with moderate permittivity. Here we propose and characterize a novel approach using artificial-dielectrics which reduces substantially the required outer diameter of the resonator. For a resonator designed to operate in a 3 Tesla scanner using water as the dielectric, a reduction in outer diameter of 37% was achieved. When used in an inductively-coupled wireless mode, the sensitivity of the artificial-dielectric resonator was measured to be slightly higher than that of a standard dielectric resonator operating in its degenerate circularly-polarized hybrid electromagnetic modes (HEM 11 ). This study demonstrates the first application of an artificial-dielectric approach to MR volume coil design. Copyright © 2018 Elsevier Inc. All rights reserved.

Use of Pulmonary Arteriovenous Extracorporeal Membrane Oxygenation in Conjunction with the Total Artificial Heart

PubMed Central

Behrens, Lindsey G.; Goodale, Nicole L.; Turek, Joseph W.; Bates, Michael J.

2015-01-01

The temporary total artificial heart (TAH-t) is approved for destination therapy or bridge to transplant and is associated with improved survival rates before and after transplantation [1]. Postoperatively, patients with the TAH-t may experience acute respiratory failure requiring significant respiratory support. Pulmonary arteriovenous extracorporeal membrane oxygenation (ECMO) has the capabilities to provide this support while minimizing the risks of barotrauma or oxygen toxicity [2]. This report presents a novel cannulation technique for ECMO to provide support for patients after the placement of the TAH-t. PMID:25910839

Developing and using artificial soils to analyze soil microbial processes

NASA Astrophysics Data System (ADS)

Gao, X.; Cheng, H. Y.; Boynton, L.; Masiello, C. A.; Silberg, J. J.

2017-12-01

Microbial diversity and function in soils are governed by soil characteristics such as mineral composition, particles size and aggregations, soil organic matter (SOM), and availability of nutrients and H2O. The spatial and temporal heterogeneity of soils creates a range of niches (hotspots) differing in the availability of O2, H2O, and nutrients, which shapes microbial activities at scales ranging from nanometer to landscape. Synthetic biologists often examine microbial response trigged by their environment conditions in nutrient-rich aqueous media using single strain microbes. While these studies provided useful insight in the role of soil microbes in important soil biogeochemical processes (e.g., C cycling, N cycling, etc.), the results obtained from the over-simplified model systems are often not applicable natural soil systems. On the contrary, soil microbiologists examine microbial processes in natural soils using longer incubation time. However, due to its physical, chemical and biological complexity of natural soils, it is often difficult to examine soil characteristics independently and understand how each characteristic influences soil microbial activities and their corresponding soil functioning. Therefore, it is necessary to bridge the gap and develop a model matrix to exclude unpredictable influences from the environment while still reliably mimicking real environmental conditions. The objective of this study is to design a range of ecologically-relevant artificial soils with varying texture (particle size distribution), structure, mineralogy, SOM content, and nutrient heterogeneity. We thoroughly characterize the artificial soils for pH, active surface area and surface morphology, cation exchange capacity (CEC), and water retention curve. We demonstrate the effectiveness of the artificial soils as useful matrix for microbial processes, such as microbial growth and horizontal gene transfer (HGT), using the gas-reporting biosensors recently developed in

An intercomparison of artificial intelligence approaches for polar scene identification

NASA Technical Reports Server (NTRS)

Tovinkere, V. R.; Penaloza, M.; Logar, A.; Lee, J.; Weger, R. C.; Berendes, T. A.; Welch, R. M.

1993-01-01

The following six different artificial-intelligence (AI) approaches to polar scene identification are examined: (1) a feed forward back propagation neural network, (2) a probabilistic neural network, (3) a hybrid neural network, (4) a 'don't care' feed forward perception model, (5) a 'don't care' feed forward back propagation neural network, and (6) a fuzzy logic based expert system. The ten classes into which six AVHRR local-coverage arctic scenes were classified were: water, solid sea ice, broken sea ice, snow-covered mountains, land, stratus over ice, stratus over water, cirrus over water, cumulus over water, and multilayer cloudiness. It was found that 'don't care' back propagation neural network produced the highest accuracies. This approach has also low CPU requirement.

Can T1 w/T2 w ratio be used as a myelin-specific measure in subcortical structures? Comparisons between FSE-based T1 w/T2 w ratios, GRASE-based T1 w/T2 w ratios and multi-echo GRASE-based myelin water fractions.

PubMed

Uddin, Md Nasir; Figley, Teresa D; Marrie, Ruth Ann; Figley, Chase R

2018-03-01

Given the growing popularity of T 1 -weighted/T 2 -weighted (T 1 w/T 2 w) ratio measurements, the objective of the current study was to evaluate the concordance between T 1 w/T 2 w ratios obtained using conventional fast spin echo (FSE) versus combined gradient and spin echo (GRASE) sequences for T 2 w image acquisition, and to compare the resulting T 1 w/T 2 w ratios with histologically validated myelin water fraction (MWF) measurements in several subcortical brain structures. In order to compare these measurements across a relatively wide range of myelin concentrations, whole-brain T 1 w magnetization prepared rapid acquisition gradient echo (MPRAGE), T 2 w FSE and three-dimensional multi-echo GRASE data were acquired from 10 participants with multiple sclerosis at 3 T. Then, after high-dimensional, non-linear warping, region of interest (ROI) analyses were performed to compare T 1 w/T 2 w ratios and MWF estimates (across participants and brain regions) in 11 bilateral white matter (WM) and four bilateral subcortical grey matter (SGM) structures extracted from the JHU_MNI_SS 'Eve' atlas. Although the GRASE sequence systematically underestimated T 1 w/T 2 w values compared to the FSE sequence (revealed by Bland-Altman and mountain plots), linear regressions across participants and ROIs revealed consistently high correlations between the two methods (r 2 = 0.62 for all ROIs, r 2 = 0.62 for WM structures and r 2 = 0.73 for SGM structures). However, correlations between either FSE-based or GRASE-based T 1 w/T 2 w ratios and MWFs were extremely low in WM structures (FSE-based, r 2 = 0.000020; GRASE-based, r 2 = 0.0014), low across all ROIs (FSE-based, r 2 = 0.053; GRASE-based, r 2 = 0.029) and moderate in SGM structures (FSE-based, r 2 = 0.20; GRASE-based, r 2 = 0.17). Overall, our findings indicated a high degree of correlation (but not equivalence) between FSE-based and GRASE-based T 1 w/T 2 w ratios, and low correlations between T 1 w/T 2 w ratios and MWFs. This

Solution structure of a DNA mimicking motif of an RNA aptamer against transcription factor AML1 Runt domain.

PubMed

Nomura, Yusuke; Tanaka, Yoichiro; Fukunaga, Jun-ichi; Fujiwara, Kazuya; Chiba, Manabu; Iibuchi, Hiroaki; Tanaka, Taku; Nakamura, Yoshikazu; Kawai, Gota; Kozu, Tomoko; Sakamoto, Taiichi

2013-12-01

AML1/RUNX1 is an essential transcription factor involved in the differentiation of hematopoietic cells. AML1 binds to the Runt-binding double-stranded DNA element (RDE) of target genes through its N-terminal Runt domain. In a previous study, we obtained RNA aptamers against the AML1 Runt domain by systematic evolution of ligands by exponential enrichment and revealed that RNA aptamers exhibit higher affinity for the Runt domain than that for RDE and possess the 5'-GCGMGNN-3' and 5'-N'N'CCAC-3' conserved motif (M: A or C; N and N' form Watson-Crick base pairs) that is important for Runt domain binding. In this study, to understand the structural basis of recognition of the Runt domain by the aptamer motif, the solution structure of a 22-mer RNA was determined using nuclear magnetic resonance. The motif contains the AH(+)-C mismatch and base triple and adopts an unusual backbone structure. Structural analysis of the aptamer motif indicated that the aptamer binds to the Runt domain by mimicking the RDE sequence and structure. Our data should enhance the understanding of the structural basis of DNA mimicry by RNA molecules.

Merkel cell polyomavirus small T antigen initiates Merkel cell carcinoma-like tumor development in mice

PubMed Central

Verhaegen, Monique E.; Mangelberger, Doris; Harms, Paul W.; Eberl, Markus; Wilbert, Dawn M.; Meireles, Julia; Bichakjian, Christopher K.; Saunders, Thomas L.; Wong, Sunny Y.; Dlugosz, Andrzej A.

2017-01-01

Merkel cell carcinoma (MCC) tumor cells express several markers detected in normal Merkel cells, a non-proliferative population of neuroendocrine cells which arise from epidermis. MCCs frequently contain Merkel cell polyomavirus (MCPyV) DNA and express viral transforming antigens, sT and tLT, but the role of these putative oncogenes in MCC development, and this tumor’s cell of origin, are unknown. Using a panel of pre-term transgenic mice, we show that epidermis-targeted co-expression of sT and the cell fate determinant atonal bHLH transcription factor 1 (Atoh1) leads to development of widespread cellular aggregates with histology and marker expression mimicking that of human intraepidermal MCC. The MCC-like tumor phenotype was dependent on the FBXW7-binding domain of sT, but not the sT-PP2A binding domain. Co-expression of MCPyV tLT did not appreciably alter the phenotype driven by either sT or sT combined with Atoh1. MCPyV sT, when co-expressed with Atoh1, is thus sufficient to initiate development of epidermis-derived MCC-like tumors in mice. PMID:28512245

Merkel Cell Polyomavirus Small T Antigen Initiates Merkel Cell Carcinoma-like Tumor Development in Mice.

PubMed

Verhaegen, Monique E; Mangelberger, Doris; Harms, Paul W; Eberl, Markus; Wilbert, Dawn M; Meireles, Julia; Bichakjian, Christopher K; Saunders, Thomas L; Wong, Sunny Y; Dlugosz, Andrzej A

2017-06-15

Merkel cell carcinoma (MCC) tumor cells express several markers detected in normal Merkel cells, a nonproliferative population of neuroendocrine cells that arise from epidermis. MCCs frequently contain Merkel cell polyomavirus (MCPyV) DNA and express viral transforming antigens, sT and tLT, but the role of these putative oncogenes in MCC development, and this tumor's cell of origin, are unknown. Using a panel of preterm transgenic mice, we show that epidermis-targeted coexpression of sT and the cell fate-determinant atonal bHLH transcription factor 1 (ATOH1) leads to development of widespread cellular aggregates, with histology and marker expression mimicking that of human intraepidermal MCC. The MCC-like tumor phenotype was dependent on the FBXW7-binding domain of sT, but not the sT-PP2A binding domain. Coexpression of MCPyV tLT did not appreciably alter the phenotype driven by either sT or sT combined with ATOH1. MCPyV sT, when coexpressed with ATOH1, is thus sufficient to initiate development of epidermis-derived MCC-like tumors in mice. Cancer Res; 77(12); 3151-7. ©2017 AACR . ©2017 American Association for Cancer Research.

Effects of B1 inhomogeneity correction for three-dimensional variable flip angle T1 measurements in hip dGEMRIC at 3 T and 1.5 T.

PubMed

Siversson, Carl; Chan, Jenny; Tiderius, Carl-Johan; Mamisch, Tallal Charles; Jellus, Vladimir; Svensson, Jonas; Kim, Young-Jo

2012-06-01

Delayed gadolinium-enhanced MRI of cartilage is a technique for studying the development of osteoarthritis using quantitative T(1) measurements. Three-dimensional variable flip angle is a promising method for performing such measurements rapidly, by using two successive spoiled gradient echo sequences with different excitation pulse flip angles. However, the three-dimensional variable flip angle method is very sensitive to inhomogeneities in the transmitted B(1) field in vivo. In this study, a method for correcting for such inhomogeneities, using an additional B(1) mapping spin-echo sequence, was evaluated. Phantom studies concluded that three-dimensional variable flip angle with B(1) correction calculates accurate T(1) values also in areas with high B(1) deviation. Retrospective analysis of in vivo hip delayed gadolinium-enhanced MRI of cartilage data from 40 subjects showed the difference between three-dimensional variable flip angle with and without B(1) correction to be generally two to three times higher at 3 T than at 1.5 T. In conclusion, the B(1) variations should always be taken into account, both at 1.5 T and at 3 T. Copyright © 2011 Wiley-Liss, Inc.

Distinct human and mouse membrane trafficking systems for sweet taste receptors T1r2 and T1r3.

PubMed

Shimizu, Madoka; Goto, Masao; Kawai, Takayuki; Yamashita, Atsuko; Kusakabe, Yuko

2014-01-01

The sweet taste receptors T1r2 and T1r3 are included in the T1r taste receptor family that belongs to class C of the G protein-coupled receptors. Heterodimerization of T1r2 and T1r3 is required for the perception of sweet substances, but little is known about the mechanisms underlying this heterodimerization, including membrane trafficking. We developed tagged mouse T1r2 and T1r3, and human T1R2 and T1R3 and evaluated membrane trafficking in human embryonic kidney 293 (HEK293) cells. We found that human T1R3 surface expression was only observed when human T1R3 was coexpressed with human T1R2, whereas mouse T1r3 was expressed without mouse T1r2 expression. A domain-swapped chimera and truncated human T1R3 mutant showed that the Venus flytrap module and cysteine-rich domain (CRD) of human T1R3 contain a region related to the inhibition of human T1R3 membrane trafficking and coordinated regulation of human T1R3 membrane trafficking. We also found that the Venus flytrap module of both human T1R2 and T1R3 are needed for membrane trafficking, suggesting that the coexpression of human T1R2 and T1R3 is required for this event. These results suggest that the Venus flytrap module and CRD receive taste substances and play roles in membrane trafficking of human T1R2 and T1R3. These features are different from those of mouse receptors, indicating that human T1R2 and T1R3 are likely to have a novel membrane trafficking system.

A biologically inspired artificial muscle based on fiber-reinforced and electropneumatic dielectric elastomers

NASA Astrophysics Data System (ADS)

Liu, Lei; Zhang, Chi; Luo, Meng; Chen, Xi; Li, Dichen; Chen, Hualing

2017-08-01

Dielectric elastomers (DEs) have great potential for use as artificial muscles because of the following characteristics: electrical activity, fast and large deformation under stimuli, and softness as natural muscles. Inspired by the traditional McKibben actuators, in this study, we developed a cylindrical soft fiber-reinforced and electropneumatic DE artificial muscle (DEAM) by mimicking the spindle shape of natural muscles. Based on continuum mechanics and variation principle, the inhomogeneous actuation of DEAMs was theoretically modeled and calculated. Prototypes of DEAMs were prepared to validate the design concept and theoretical model. The theoretical predictions are consistent with the experimental results; they successfully predicted the evolutions of the contours of DEAMs with voltage. A pneumatically supported high prestretch in the hoop direction was achieved by our DEAM prototype without buckling the soft fibers sandwiched by the DE films. Besides, a continuously tunable prestretch in the actuation direction was achieved by varying the supporting pressure. Using the theoretical model, the failure modes, maximum actuations, and critical voltages were analyzed; they were highly dependent on the structural parameters, i.e., the cylinder aspect ratio, prestretch level, and supporting pressure. The effects of structural parameters and supporting pressure on the actuation performance were also investigated to optimize the DEAMs.

Artificial Root Exudate System (ARES): a field approach to simulate tree root exudation in soils

NASA Astrophysics Data System (ADS)

Lopez-Sangil, Luis; Estradera-Gumbau, Eduard; George, Charles; Sayer, Emma

2016-04-01

The exudation of labile solutes by fine roots represents an important strategy for plants to promote soil nutrient availability in terrestrial ecosystems. Compounds exuded by roots (mainly sugars, carboxylic and amino acids) provide energy to soil microbes, thus priming the mineralization of soil organic matter (SOM) and the consequent release of inorganic nutrients into the rhizosphere. Studies in several forest ecosystems suggest that tree root exudates represent 1 to 10% of the total photoassimilated C, with exudation rates increasing markedly under elevated CO2 scenarios. Despite their importance in ecosystem functioning, we know little about how tree root exudation affect soil carbon dynamics in situ. This is mainly because there has been no viable method to experimentally control inputs of root exudates at field scale. Here, I present a method to apply artificial root exudates below the soil surface in small field plots. The artificial root exudate system (ARES) consists of a water container with a mixture of labile carbon solutes (mimicking tree root exudate rates and composition), which feeds a system of drip-tips covering an area of 1 m2. The tips are evenly distributed every 20 cm and inserted 4-cm into the soil with minimal disturbance. The system is regulated by a mechanical timer, such that artificial root exudate solution can be applied at frequent, regular daily intervals. We tested ARES from April to September 2015 (growing season) within a leaf-litter manipulation experiment ongoing in temperate deciduous woodland in the UK. Soil respiration was measured monthly, and soil samples were taken at the end of the growing season for PLFA, enzymatic activity and nutrient analyses. First results show a very rapid mineralization of the root exudate compounds and, interestingly, long-term increases in SOM respiration, with negligible effects on soil moisture levels. Large positive priming effects (2.5-fold increase in soil respiration during the growing

An Artificial Particle Precipitation Technique Using HAARP-Generated VLF Waves

DTIC Science & Technology

2006-11-02

AFRL-VS-HA-TR-2007-1021 An Artificial Particle Precipitation Technique Using HAARP -Generated VLF Waves O o o r- Q M. J. Kosch T. Pedersen J...Artificial Particle Precipitation Technique Using HAARP Generated VLF Waves. 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 62101F...model. The frequency-time modulated VLF wave patterns have been successfully implemented at the HAARP ionospheric modification facility in Alaska

Hymenobacter aquatilis sp. nov., isolated from a mesotrophic artificial lake.

PubMed

Kang, Heeyoung; Cha, Inseong; Kim, Haneul; Joh, Kiseong

2018-06-01

A novel strain, designated HMF3095 T , isolated from freshwater of a mesotrophic artificial lake in the Republic of Korea, was characterized by polyphasic taxonomy. The cells were Gram-stain-negative, aerobic, non-motile, straight rods and formed reddish colonies. Phylogenetic analysis based on its 16S rRNA gene sequence revealed that strain HMF3095 T fell within the cluster of the genus Hymenobacterand was most closely related to Hymenobacter seoulensis 16F7G T and Hymenobacter tenuis POB6 T (96.7 % sequence similarity). Sequence similarities to all other type strains were 96.3 % or less. The major fatty acids were iso-C15 : 0, C16 : 1ω5c, summed feature 4 (iso-C17 : 1 I and/or anteiso-C17 : 1 B), summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c) and anteiso-C15 : 0. The major isoprenoid quinone was menaquinone 7. The major polar lipids were phosphatidylethanolamine, three unidentified aminophospholipids and one unidentified phospholipid. The DNA G+C content was 58.9 mol%. On the basis of the evidence presented in this study, strain HMF3095 T represents a novel species of the genus Hymenobacter, for which the name Hymenobacter aquatilis sp. nov. is proposed. The type strain is HMF3095 T (=KCTC 52398 T =NBRC 112669 T ).

Cystic Benign Metastasizing Leiomyoma of the Lung Mimicking Hydatid Cyst.

PubMed

Alimi, Faouzi; El Hadj Sidi, Chighali; Ghannouchi, Chams

2016-12-01

A 60-year-old woman, with history of a resected uterine benign leiomyoma, is operated for a cystic lesion in the left lung, mimicking an hydatid cyst, and confirmed histologically as Cystic Benign Metastasizing Leiomyoma.

49 CFR 176.148 - Artificial lighting.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 2 2010-10-01 2010-10-01 false Artificial lighting. 176.148 Section 176.148... Requirements for Class 1 (Explosive) Materials Precautions During Loading and Unloading § 176.148 Artificial lighting. Electric lights, except arc lights, are the only form of artificial lighting permitted when...

49 CFR 176.148 - Artificial lighting.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 2 2011-10-01 2011-10-01 false Artificial lighting. 176.148 Section 176.148... Requirements for Class 1 (Explosive) Materials Precautions During Loading and Unloading § 176.148 Artificial lighting. Electric lights, except arc lights, are the only form of artificial lighting permitted when...

Close relationship of tissue plasminogen activator-plasminogen activator inhibitor-1 complex with multiple organ dysfunction syndrome investigated by means of the artificial pancreas

PubMed Central

Hoshino, Masami; Haraguchi, Yoshikura; Hirasawa, Hiroyuki; Sakai, Motohiro; Saegusa, Hiroshi; Hayashi, Kazushiro; Horita, Naoki; Ohsawa, Hiroyuki

2001-01-01

Background: Glucose tolerance (GT) has not been taken into consideration in investigations concerning relationships between coagulopathy and multiple organ dysfunction syndrome (MODS), and endothelial cell activation/endothelial cell injury (ECA/ECI) in septic patients, although coagulopathy is known to be influenced by blood glucose level. We investigated those relationships under strict blood glucose control and evaluation of GT with the glucose clamp method by means of the artificial pancreas in nine septic patients with glucose intolerance. The relationships between GT and blood stress related hormone levels (SRH) were also investigated. Methods: The amount of metabolized glucose (M value), as the parameter of GT, was measured by the euglycemic hyperinsulinemic glucose clamp method, in which the blood glucose level was clamped at 80 mg/dl under a continuous insulin infusion rate of 1.12 mU/kg per min, using the artificial pancreas, STG-22. Multiple organ failure (MOF) score was calculated using the MOF criteria of Japanese Association for Critical Care Medicine. Regarding coagulopathy, the following parameters were used: disseminated intravascular coagulation (DIC) score (calculated from the DIC criteria of the Ministry of Health and Welfare of Japan) and the parameters used for calculating DIC score, protein-C, protein-S, plasminogen, antithrombin III (AT-III), plasminogen activator inhibitor-1 (PAI-1), and tissue plasminogen activator-PAI-1 (tPA-PAI-1) complex. Thrombomodulin (TM) was measured as the indicator of ECI. Results: There were no significant correlations between M value and SRH, parameters indicating coagulopathy and the MOF score. The MOF score and blood TM levels were positively correlated with DIC score, thrombin-AT-III complex and tPA-PAI-1 complex, and negatively correlated with blood platelet count. Conclusions: GT was not significantly related to SRH, coagulopathy and MODS under strict blood glucose control. Hypercoagulability was closely

Clinical and Histologic Mimickers of Celiac Disease.

PubMed

Kamboj, Amrit K; Oxentenko, Amy S

2017-08-17

Celiac disease is an autoimmune disorder of the small bowel, classically associated with diarrhea, abdominal pain, and malabsorption. The diagnosis of celiac disease is made when there are compatible clinical features, supportive serologic markers, representative histology from the small bowel, and response to a gluten-free diet. Histologic findings associated with celiac disease include intraepithelial lymphocytosis, crypt hyperplasia, villous atrophy, and a chronic inflammatory cell infiltrate in the lamina propria. It is important to recognize and diagnose celiac disease, as strict adherence to a gluten-free diet can lead to resolution of clinical and histologic manifestations of the disease. However, many other entities can present with clinical and/or histologic features of celiac disease. In this review article, we highlight key clinical and histologic mimickers of celiac disease. The evaluation of a patient with serologically negative enteropathy necessitates a carefully elicited history and detailed review by a pathologist. Medications can mimic celiac disease and should be considered in all patients with a serologically negative enteropathy. Many mimickers of celiac disease have clues to the underlying diagnosis, and many have a targeted therapy. It is necessary to provide patients with a correct diagnosis rather than subject them to a lifetime of an unnecessary gluten-free diet.

[Modulation of T1R chemosensory receptors for sweet nutrients - new paradigms in metabolic regulation].

PubMed

Maillet, Emeline L

2011-02-01

Recent studies have demonstrated that the sweet-sensing receptors T1R2/3, thought to be "taste receptors" specifically expressed in lingual system, are also expressed and involved in the chemo-detection of sweetening molecules circulating in other organs. Researches that focus on their roles in intestinal absorption, metabolic regulation and glucose homeostasis, in particular, are increasing. Indeed, the sweet-sensing receptor could provide a new therapeutic target for certain metabolic disorders and diseases like obesity and diabetes. If the natural and artificial sweeteners agonists are diverse and well known, the "anti-sweeteners" antagonistic molecules are a class of compounds that received very little attention until now. Their potential roles and pharmacological relevance outside the taste system are discussed. Moreover, the recent finding that 2 major classes of compounds belonging respectively to the fields of medicine (fibrates) and agriculture (phenoxy-herbicides) are potent inhibitors of human T1R3 receptor is reported, raising new questions about their potential impact on human metabolism. © 2011 médecine/sciences - Inserm / SRMS.

A Thr/Ser dual residue motif in the cytoplasmic tail of human CD1d is important for the down-regulation of antigen presentation following a herpes simplex virus 1 infection

PubMed Central

Liu, Jianyun; Glosson, Nicole L; Du, Wenjun; Gervay-Hague, Jacquelyn; Brutkiewicz, Randy R

2013-01-01

CD1d-restricted T (natural killer T; NKT) cells are important for controlling herpesvirus infections. Interestingly, herpes simplex virus (HSV) can down-regulate CD1d-mediated activation of NKT cells. We have previously shown that the Thr322 residue in the cytoplasmic tail of human CD1d is important for its intracellular trafficking and functional expression. We proposed that the phosphorylation of T322 is a signal for CD1d lysosomal targeting and subsequent degradation. In the current study, we generated dual mutants by substituting the T322 and S323 residues of wild-type (WT) CD1d with Ala (non-phosphorylatable) or Asp (mimicking phosphorylation) and ectopically expressed them in human embryonic kidney 293 cells. We found that the surface expression levels of the CD1d mutants was in this order: T322AS323A > WT > T322A > S323A > S323D > T322D > T322DS323D. Our results therefore suggest that mimicking the phosphorylation of both T322 and S323 has a cumulative negative effect on the functional expression of CD1d. As previously reported, we also found that upon an HSV infection, antigen presentation by WT CD1d is reduced and the CD1d molecule is degraded. Interestingly, the T322A/S323A double mutation inhibited CD1d degradation and rescued CD1d-mediated antigen presentation following an HSV-1 infection. This suggests that the T322/S323 dyad may be phosphorylated, which then targets CD1d for lysosomal degradation post-infection as a means of immune evasion, explaining (at least in part) the reduced antigen presentation observed. Hence, our findings strongly suggest that T322 and S323 form a dual residue motif that can regulate the functional expression of CD1d during a viral infection. PMID:23710894

Rational Design of Pathogen-Mimicking Amphiphilic Materials as Nanoadjuvants

NASA Astrophysics Data System (ADS)

Ulery, Bret D.; Petersen, Latrisha K.; Phanse, Yashdeep; Kong, Chang Sun; Broderick, Scott R.; Kumar, Devender; Ramer-Tait, Amanda E.; Carrillo-Conde, Brenda; Rajan, Krishna; Wannemuehler, Michael J.; Bellaire, Bryan H.; Metzger, Dennis W.; Narasimhan, Balaji

2011-12-01

An opportunity exists today for cross-cutting research utilizing advances in materials science, immunology, microbial pathogenesis, and computational analysis to effectively design the next generation of adjuvants and vaccines. This study integrates these advances into a bottom-up approach for the molecular design of nanoadjuvants capable of mimicking the immune response induced by a natural infection but without the toxic side effects. Biodegradable amphiphilic polyanhydrides possess the unique ability to mimic pathogens and pathogen associated molecular patterns with respect to persisting within and activating immune cells, respectively. The molecular properties responsible for the pathogen-mimicking abilities of these materials have been identified. The value of using polyanhydride nanovaccines was demonstrated by the induction of long-lived protection against a lethal challenge of Yersinia pestis following a single administration ten months earlier. This approach has the tantalizing potential to catalyze the development of next generation vaccines against diseases caused by emerging and re-emerging pathogens.

Wear resistance of a modified polymethyl methacrylate artificial tooth compared to five commercially available artificial tooth materials.

PubMed

Kamonwanon, Pranithida; Yodmongkol, Sirasa; Chantarachindawong, Rojcharin; Thaweeboon, Sroisiri; Thaweeboon, Boonyanit; Srikhirin, Toemsak

2015-08-01

Wear resistance is a limitation of artificial denture teeth. Improving the wear resistance of conventional artificial denture teeth is of value to prosthodontic patients. The purpose of this in vitro study was to evaluate the wear resistance and hardness of modified polymethyl methacrylate artificial denture teeth compared to 5 commercially available artificial tooth materials. This study evaluated 180 artificial denture teeth (6 groups) that included 3 groups of conventional artificial teeth (MajorDent, Cosmo HXL, and Gnathostar), 2 groups of composite resin artificial teeth (Endura and SR Orthosit PE), and 1 group of modified surface artificial teeth. The flattened buccal surface of each tooth (n=15) was prepared for investigation with the Vickers hardness test and the elucidate wear test (n=15) by using a brushing machine. Each group was loaded for 18,000 cycles, at 2 N, and 150 rpm. The wear value was identified with a profilometer. The data were statistically analyzed by using 1-way ANOVA and post hoc Turkey honestly significant difference tests (α=.001). The tribologies were observed under a scanning electron microscope, and the cytotoxicities were evaluated by MTT assay. The Vickers hardnesses ranged from 28.48 to 39.36. The wear depths and worn surface area values ranged from 1.12 to 10.79 μm and from 6.74 to 161.95 μm(2). The data revealed that the modified artificial denture teeth were significantly harder and exhibited significantly higher wear resistance than did the conventional artificial teeth (P<.001). The scanning electron microscopic images revealed cross sections of the conventional artificial denture teeth with intensively worn surface areas after brushing. The cytotoxicity test revealed 97.85% cell viability, which indicates the nontoxicity of the modified surface of this material. Within the limitations of this study, the polymethyl methacrylate modified surface artificial denture teeth was not significantly different from that of the

Artificial Leaf Based on Artificial Photosynthesis for Solar Fuel Production

DTIC Science & Technology

2017-06-30

AFRL-AFOSR-JP-TR-2017-0054 Artificial Leaf Based on Artificial Photosynthesis for Solar Fuel Production Mamoru Nango NAGOYA INSTITUTE OF TECHNOLOGY...for Solar Fuel Production 5a.  CONTRACT NUMBER 5b.  GRANT NUMBER FA2386-14-1-4015 5c.  PROGRAM ELEMENT NUMBER 61102F 6. AUTHOR(S) Mamoru Nango 5d...density immobilization of the photoreactants in the nanocavity inside PGP. The maximum production efficiency of formic acid inside the nanocavity was

Modeling T1 and T2 relaxation in bovine white matter

NASA Astrophysics Data System (ADS)

Barta, R.; Kalantari, S.; Laule, C.; Vavasour, I. M.; MacKay, A. L.; Michal, C. A.

2015-10-01

The fundamental basis of T1 and T2 contrast in brain MRI is not well understood; recent literature contains conflicting views on the nature of relaxation in white matter (WM). We investigated the effects of inversion pulse bandwidth on measurements of T1 and T2 in WM. Hybrid inversion-recovery/Carr-Purcell-Meiboom-Gill experiments with broad or narrow bandwidth inversion pulses were applied to bovine WM in vitro. Data were analysed with the commonly used 1D-non-negative least squares (NNLS) algorithm, a 2D-NNLS algorithm, and a four-pool model which was based upon microscopically distinguishable WM compartments (myelin non-aqueous protons, myelin water, non-myelin non-aqueous protons and intra/extracellular water) and incorporated magnetization exchange between adjacent compartments. 1D-NNLS showed that different T2 components had different T1 behaviours and yielded dissimilar results for the two inversion conditions. 2D-NNLS revealed significantly more complicated T1/T2 distributions for narrow bandwidth than for broad bandwidth inversion pulses. The four-pool model fits allow physical interpretation of the parameters, fit better than the NNLS techniques, and fits results from both inversion conditions using the same parameters. The results demonstrate that exchange cannot be neglected when analysing experimental inversion recovery data from WM, in part because it can introduce exponential components having negative amplitude coefficients that cannot be correctly modeled with nonnegative fitting techniques. While assignment of an individual T1 to one particular pool is not possible, the results suggest that under carefully controlled experimental conditions the amplitude of an apparent short T1 component might be used to quantify myelin water.

Clinical application of Sleeping Beauty and artificial antigen presenting cells to genetically modify T cells from peripheral and umbilical cord blood.

PubMed

Huls, M Helen; Figliola, Matthew J; Dawson, Margaret J; Olivares, Simon; Kebriaei, Partow; Shpall, Elizabeth J; Champlin, Richard E; Singh, Harjeet; Cooper, Laurence J N

2013-02-01

The potency of clinical-grade T cells can be improved by combining gene therapy with immunotherapy to engineer a biologic product with the potential for superior (i) recognition of tumor-associated antigens (TAAs), (ii) persistence after infusion, (iii) potential for migration to tumor sites, and (iv) ability to recycle effector functions within the tumor microenvironment. Most approaches to genetic manipulation of T cells engineered for human application have used retrovirus and lentivirus for the stable expression of CAR(1-3). This approach, although compliant with current good manufacturing practice (GMP), can be expensive as it relies on the manufacture and release of clinical-grade recombinant virus from a limited number of production facilities. The electro-transfer of nonviral plasmids is an appealing alternative to transduction since DNA species can be produced to clinical grade at approximately 1/10(th) the cost of recombinant GMP-grade virus. To improve the efficiency of integration we adapted Sleeping Beauty (SB) transposon and transposase for human application(4-8). Our SB system uses two DNA plasmids that consist of a transposon coding for a gene of interest (e.g. 2(nd) generation CD19-specific CAR transgene, designated CD19RCD28) and a transposase (e.g. SB11) which inserts the transgene into TA dinucleotide repeats(9-11). To generate clinically-sufficient numbers of genetically modified T cells we use K562-derived artificial antigen presenting cells (aAPC) (clone #4) modified to express a TAA (e.g. CD19) as well as the T cell costimulatory molecules CD86, CD137L, a membrane-bound version of interleukin (IL)-15 (peptide fused to modified IgG4 Fc region) and CD64 (Fc-γ receptor 1) for the loading of monoclonal antibodies (mAb)(12). In this report, we demonstrate the procedures that can be undertaken in compliance with cGMP to generate CD19-specific CAR(+) T cells suitable for human application. This was achieved by the synchronous electro-transfer of

Epidermal cyst mimicking incision line metastasis.

PubMed

Gündoğdu, Ramazan; Ayhan, Erhan; Çolak, Tahsin

2017-01-01

Epidermal cysts are cystic tumors lined with keratinized squamous layer and filled with keratin debris. Epidermal cysts may develop by implantation of surface epidermal layer into the dermis or subcutaneous tissue after trauma or surgical procedures. Cervix cancer spreads either directly or via the vascular and lymphatic systems. Distant skin metastasis of endometrium or cervix cancer is very rare. In this case report, a patient who had a history of cervix cancer operation 11 years ago and presented with a mass that mimicked incision line metastasis and was histopathologically diagnosed with epidermal cyst is presented.

Tagging motor memories with transcranial direct current stimulation allows later artificially-controlled retrieval

PubMed Central

Nozaki, Daichi; Yokoi, Atsushi; Kimura, Takahiro; Hirashima, Masaya; Orban de Xivry, Jean-Jacques

2016-01-01

We demonstrate that human motor memories can be artificially tagged and later retrieved by noninvasive transcranial direct current stimulation (tDCS). Participants learned to adapt reaching movements to two conflicting dynamical environments that were each associated with a different tDCS polarity (anodal or cathodal tDCS) on the sensorimotor cortex. That is, we sought to determine whether divergent background activity levels within the sensorimotor cortex (anodal: higher activity; cathodal: lower activity) give rise to distinct motor memories. After a training session, application of each tDCS polarity automatically resulted in the retrieval of the motor memory corresponding to that polarity. These results reveal that artificial modulation of neural activity in the sensorimotor cortex through tDCS can act as a context for the formation and recollection of motor memories. DOI: http://dx.doi.org/10.7554/eLife.15378.001 PMID:27472899

An overview of artificial intelligence and robotics. Volume 1: Artificial intelligence. Part C: Basic AI topics

NASA Technical Reports Server (NTRS)

Gevarter, W. B.

1983-01-01

Readily understandable overviews of search oriented problem solving, knowledge representation, and computational logic are provided. Mechanization, automation and artificial intelligence are discussed as well as how they interrelate.

Relaxivity of Ferumoxytol at 1.5 T and 3.0 T.

PubMed

Knobloch, Gesine; Colgan, Timothy; Wiens, Curtis N; Wang, Xiaoke; Schubert, Tilman; Hernando, Diego; Sharma, Samir D; Reeder, Scott B

2018-05-01

The aim of this study was to determine the relaxation properties of ferumoxytol, an off-label alternative to gadolinium-based contrast agents, under physiological conditions at 1.5 T and 3.0 T. Ferumoxytol was diluted in gradually increasing concentrations (0.26-4.2 mM) in saline, human plasma, and human whole blood. Magnetic resonance relaxometry was performed at 37°C at 1.5 T and 3.0 T. Longitudinal and transverse relaxation rate constants (R1, R2, R2*) were measured as a function of ferumoxytol concentration, and relaxivities (r1, r2, r2*) were calculated. A linear dependence of R1, R2, and R2* on ferumoxytol concentration was found in saline and plasma with lower R1 values at 3.0 T and similar R2 and R2* values at 1.5 T and 3.0 T (1.5 T: r1saline = 19.9 ± 2.3 smM; r1plasma = 19.0 ± 1.7 smM; r2saline = 60.8 ± 3.8 smM; r2plasma = 64.9 ± 1.8 smM; r2*saline = 60.4 ± 4.7 smM; r2*plasma = 64.4 ± 2.5 smM; 3.0 T: r1saline = 10.0 ± 0.3 smM; r1plasma = 9.5 ± 0.2 smM; r2saline = 62.3 ± 3.7 smM; r2plasma = 65.2 ± 1.8 smM; r2*saline = 57.0 ± 4.7 smM; r2*plasma = 55.7 ± 4.4 smM). The dependence of relaxation rates on concentration in blood was nonlinear. Formulas from second-order polynomial fittings of the relaxation rates were calculated to characterize the relationship between R1blood and R2 blood with ferumoxytol. Ferumoxytol demonstrates strong longitudinal and transverse relaxivities. Awareness of the nonlinear relaxation behavior of ferumoxytol in blood is important for ferumoxytol-enhanced magnetic resonance imaging applications and for protocol optimization.

Friedreich's ataxia mimicking hereditary motor and sensory neuropathy.

PubMed

Panas, Marios; Kalfakis, Nikolaos; Karadima, Georgia; Davaki, Panagiota; Vassilopoulos, Demetris

2002-11-01

Four patients from three unrelated families, with clinical and electrophysiological findings compatible with the diagnosis of hereditary motor and sensory neuropathy, are presented. The molecular analysis showed that the affected individuals were homozygous for the mutation in the X25 gene, characteristic of Friedreich's ataxia. These patients seem to represent a form of Friedreich's ataxia mimicking Charcot-Marie-Tooth disease.

Central nervous system borreliosis mimicking a pontine tumour.

PubMed

Latsch, Kirsten; Tappe, Dennis; Warmuth-Metz, Monika; Hebestreit, Helge

2006-11-01

In childhood, facial nerve palsy and headache are typical symptoms of second and third stage neuroborreliosis. While focal demyelination is occasionally observed on MRI scans, the appearance of a tumorous lesion is extremely rare. The case of a 10-year-old girl with neuroborreliosis mimicking a space-occupying lesion in the brainstem, without any previously recognized manifestations of borreliosis, is reported.

A Proteomic View at T Cell Costimulation

PubMed Central

Hombach, Andreas A.; Recktenwald, Christian V.; Dressler, Sven P.; Abken, Hinrich; Seliger, Barbara

2012-01-01

The “two-signal paradigm” in T cell activation predicts that the cooperation of “signal 1,” provided by the T cell receptor (TCR) through engagement of major histocompatility complex (MHC)-presented peptide, with “signal 2″ provided by costimulatory molecules, the prototype of which is CD28, is required to induce T cell effector functions. While the individual signalling pathways are well understood, little is known about global changes in the proteome pattern during TCR/CD28-mediated activation. Therefore, comparative 2-DE-based proteome analyses of CD3+ CD69- resting T cells versus cells incubated with (i) the agonistic anti-CD3 antibody OKT3 mimicking signal 1 in absence or presence of IL-2 and/or with (ii) the agonistic antibody 15E8 triggering CD28-mediated signaling were performed. Differentially regulated spots were defined leading to the identification of proteins involved in the regulation of the metabolism, shaping and maintenance of the cytoskeleton and signal transduction. Representative members of the differentially expressed protein families, such as calmodulin (CALM), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), L-lactate dehydrogenase (LDH), Rho GDP-dissociation inhibitor 2 (GDIR2), and platelet basic protein (CXCL7), were independently verified by flow cytometry. Data provide a detailed map of individual protein alterations at the global proteome level in response to TCR/CD28-mediated T cell activation. PMID:22539942

Cardiac Iron Determines Cardiac T2*, T2, and T1 in the Gerbil Model of Iron Cardiomyopathy

PubMed Central

Wood, John C.; Otto-Duessel, Maya; Aguilar, Michelle; Nick, Hanspeter; Nelson, Marvin D.; Coates, Thomas D.; Pollack, Harvey; Moats, Rex

2010-01-01

Background Transfusional therapy for thalassemia major and sickle cell disease can lead to iron deposition and damage to the heart, liver, and endocrine organs. Iron causes the MRI parameters T1, T2, and T2* to shorten in these organs, which creates a potential mechanism for iron quantification. However, because of the danger and variability of cardiac biopsy, tissue validation of cardiac iron estimates by MRI has not been performed. In this study, we demonstrate that iron produces similar T1, T2, and T2* changes in the heart and liver using a gerbil iron-overload model. Methods and Results Twelve gerbils underwent iron dextran loading (200 mg · kg−1 · wk−1) from 2 to 14 weeks; 5 age-matched controls were studied as well. Animals had in vivo assessment of cardiac T2* and hepatic T2 and T2* and postmortem assessment of cardiac and hepatic T1 and T2. Relaxation measurements were performed in a clinical 1.5-T magnet and a 60-MHz nuclear magnetic resonance relaxometer. Cardiac and liver iron concentrations rose linearly with administered dose. Cardiac 1/T2*, 1/T2, and 1/T1 rose linearly with cardiac iron concentration. Liver 1/T2*, 1/T2, and 1/T1 also rose linearly, proportional to hepatic iron concentration. Liver and heart calibrations were similar on a dry-weight basis. Conclusions MRI measurements of cardiac T2 and T2* can be used to quantify cardiac iron. The similarity of liver and cardiac iron calibration curves in the gerbil suggests that extrapolation of human liver calibration curves to heart may be a rational approximation in humans. PMID:16027257

Breath-hold black-blood T1rho mapping improves liver T1rho quantification in healthy volunteers.

PubMed

Wáng, Yì Xiáng J; Deng, Min; Lo, Gladys G; Liang, Dong; Yuan, Jing; Chen, Weitian

2018-03-01

Background Recent researches suggest that T1rho may be a non-invasive and quantitative technique for detecting and grading liver fibrosis. Purpose To compare a multi-breath-hold bright-blood fast gradient echo (GRE) imaging and a single breath-hold single-shot fast spin echo (FSE) imaging with black-blood effect for liver parenchyma T1rho measurement and to study liver physiological T1rho value in healthy volunteers. Material and Methods The institutional Ethics Committee approved this study. 28 healthy participants (18 men, 10 women; age = 29.6 ± 5.1 years) underwent GRE liver T1rho imaging, and 20 healthy participants (10 men, 10 women; age = 36.9 ± 10.3 years) underwent novel black-blood FSE liver T1rho imaging, both at 3T with spin-lock frequency of 500 Hz. The FSE technique allows simultaneous acquisition of four spin lock times (TSLs; 1 ms, 10 ms, 30 ms, 50msec) in 10 s. Results For FSE technique the intra-scan repeatability intraclass correlation coefficient (ICC) was 0.98; while the inter-scan reproducibility ICC was 0.82 which is better than GRE technique's 0.76. Liver T1rho value in women tended to have a higher value than T1rho values in men (FSE: 42.28 ± 4.06 ms for women and 39.13 ± 2.12 ms for men; GRE: 44.44 ± 1.62 ms for women and 42.36 ± 2.00 ms for men) and FSE technique showed liver T1rho value decreased slightly as age increased. Conclusion Single breath-hold black-blood FSE sequence has better scan-rescan reproducibility than multi-breath-hold bright-blood GRE sequence. Gender and age dependence of liver T1rho in healthy participants is observed, with young women tending to have a higher T1rho measurement.

Toxoplasma gondii transmission by artificial insemination in sheep with experimentally contaminated frozen semen.

PubMed

Consalter, Angélica; Silva, Andressa F; Frazão-Teixeira, Edwards; Matos, Luis F; de Oliveira, Francisco C R; Leite, Juliana S; Silva, Franciele B F; Ferreira, Ana M R

2017-03-01

Toxoplasma gondii is a parasite considered one of the major causes of reproductive problems in sheep. Furthermore, the presence of the agent in ram semen urges the possibility of sexual transmission in this species. The aim of this study was to evaluate if ram's frozen semen spiked with T. gondii tachyzoites would be able to cause infection in sheep by laparoscopic artificial insemination (AI). Nine ewes tested seronegative to anti-T. gondii antibodies by the modified agglutination test (MAT) were superovulated and inseminated to collect embryos. Animals were divided into two groups: G1 (n = 5), ewes inseminated with semen containing 4 × 10 7 tachyzoites; and G2 (n = 4), ewes inseminated with tachyzoite-free semen (control group). To confirm infection, ewe's blood samples were collected on days -14, -7, 0, 7, 14, 21, 28, 35, 49 and 57 after AI for analysis by MAT and PCR. Tissue samples of these ewes were also collected for histopathology and immunohistochemistry (IHC). Seven days after AI, all ewes of group G1 had specific antibodies to T. gondii, while those of G2 were negative. Toxoplasma gondii DNA was detected in the blood of one ewe and parasites were observed in tissues of all five animals inseminated with contaminated semen, indicating that semen freezing protocol does not affect T. gondii transmission by artificial insemination in sheep. Copyright © 2016 Elsevier Inc. All rights reserved.

Testing in artificial sweat - Is less more? Comparison of metal release in two different artificial sweat solutions.

PubMed

Midander, Klara; Julander, Anneli; Kettelarij, Jolinde; Lidén, Carola

2016-11-01

Metal release from materials immersed in artificial sweat can function as a measure of potential skin exposure. Several artificial sweat models exist that, to various degree, mimic realistic conditions. Study objective was to evaluate metal release from previously examined and well characterized materials in two different artificial sweat solutions; a comprehensive sweat model intended for use within research, based on the composition of human sweat; and the artificial sweat, EN1811, intended for testing compliance with the nickel restriction in REACH. The aim was to better understand whether there are advantages using either of the sweat solutions in bio-elution testing of materials. Metal release in two different artificial sweat solutions was compared for discs of a white gold alloy and two hard metals, and a rock drilling insert of tungsten carbide at 1 h, 24 h, 1 week and 1 month. The released amount of metal was analysed by means of inductively coupled plasma mass spectrometry. Similar levels of released metals were measured from test materials in the two different artificial sweat solutions. For purposes in relation to legislations, it was concluded that a metal release test using a simple artificial sweat composition may provide results that sufficiently indicate the degree of metal release at skin contact. Copyright © 2016 Elsevier Inc. All rights reserved.

T1ρ Dispersion in Articular Cartilage

PubMed Central

Besier, Thor F.; Pauly, John M.; Smith, R. Lane; Delp, Scott L.; Beaupre, Gary S.; Gold, Garry E.

2015-01-01

Objective This study assessed T1ρ relaxation dispersion, measured by magnetic resonance imaging (MRI), as a tool to noninvasively evaluate cartilage material and biochemical properties. The specific objective was to answer two questions: (1) does cartilage initial elastic modulus (E0) correlate with T1ρ dispersion effects and (2) does collagen or proteoglycan content correlate with T1ρ dispersion effects? Design Cadaveric patellae with and without visible cartilage damage on conventional MR were included. T2 and T1ρ relaxation times at 500 and 1000 Hz spin-lock field amplitudes were measured. We estimated T1ρ dispersion effects by measuring T1ρ relaxation time at 500 and 1000 Hz and T2 relaxation time and using a new tool, the ratio T1ρ/T2. Cartilage initial elastic modulus, E0, was measured from initial response of mechanical indentation creep tests. Collagen and proteoglycan contents were measured at the indentation test sites; proteoglycan content was measured by their covalently linked sulfated glycosaminoglycans (sGAG). Pearson correlation coefficients were determined, taking into account the clustering of multiple samples within a single patella specimen. Results Cartilage initial elastic modulus, E0, increased with decreasing values of T1ρ/T2 measurements at both 500 Hz (P = 0.034) and 1000 Hz (P = 0.022). 1/T1ρ relaxation time (500 Hz) increased with increasing sGAG content (P = 0.041). Conclusions T1ρ/T2 ratio, a new tool, and cartilage initial elastic modulus are both measures of water–protein interactions, are dependent on the cartilage structure, and were correlated in this study. PMID:26069714

T-cell receptor transfer for boosting HIV-1-specific T-cell immunity in HIV-1-infected patients.

PubMed

Mummert, Christiane; Hofmann, Christian; Hückelhoven, Angela G; Bergmann, Silke; Mueller-Schmucker, Sandra M; Harrer, Ellen G; Dörrie, Jan; Schaft, Niels; Harrer, Thomas

2016-09-10

Strategies to cure HIV-1 infection require the eradication of viral reservoirs. An innovative approach for boosting the cytotoxic T-lymphocyte response is the transfer of T-cell receptors (TCRs). Previously, we have shown that electroporation of TCR-encoding mRNA is able to reprogram CD8 T cells derived from healthy donors. So far, it is unknown whether the transfer of HIV-1-specific TCRs is capable to reprogram CD8 T cells of HIV-1-infected patients. To assess the efficiency of TCR-transfer by mRNA electroporation and the functionality of reprogramed T cells in HIV-1-infected patients, we performed an in-vitro analysis of TCR-transfer into T cells from HIV-1-infected patients in various stages of disease and from healthy controls. Peripheral blood mononuclear cells from 16 HIV-1-infected patients (nine HLA-A02-positive, seven HLA-A02-negative) and from five healthy controls were electroporated with mRNA-constructs encoding TCRs specific for the HLA-A02/HIV-1-gag p17 epitope SLYNTVATL (SL9). Functionality of the TCRs was measured by γIFN-ELISpot assays. SL9/TCR transfection into peripheral blood mononuclear cells from both HLA-A02-positive and HLA-A02-negative HIV-1-infected patients and from healthy blood donors reprogramed T cells for recognition of SL9-presenting HLA-A02-positive cells in γIFN-ELISpot assays. SL9/TCR-transfer into T cells from an immunodeficient AIDS patient could induce recognition of SL9-expressing target cells only after reversion of T-cell dysfunction by antiretroviral therapy. The transfer of HIV-1-p17-specific TCRs into T cells is functional both in HIV-1-infected patients as well as in healthy blood donors. TCR-transfer is a promising method to boost the immune system against HIV-1.

[Clinical application of artificial dermis combined with basic fibroblast growth factor in the treatment of cicatrix and deep skin wounds].

PubMed

Liu, Yang; Zhang, Yilan; Huang, Yalan; Luo, Gaoxing; Peng, Yizhi; Yan, Hong; Luo, Qizhi; Zhang, Jiaping; Wu, Jun; Peng, Daizhi

2016-04-01

To observe the effects of artificial dermis combined with basic fibroblast growth factor (bFGF) on the treatment of cicatrix and deep skin wounds. The clinical data of 72 patients with wounds repaired with artificial dermis, hospitalized in our unit from October 2010 to April 2015, conforming to the study criteria, were retrospectively analyzed. The types of wounds were wounds after resection of cicatrices, deep burn wounds without exposure of tendon or bone, and wounds with exposure of small area of tendon or bone, in a total number of 102. Wounds were divided into artificial dermis group (A, n=60) and artificial dermis+ bFGF group (B, n=42) according to whether or not artificial dermis combined with bFGF. In group A, after release and resection of cicatrices or thorough debridement of deep skin wounds, artificial dermis was directly grafted to wounds in the first stage operation. After complete vascularization of artificial dermis, wounds were repaired with autologous split-thickness skin grafts in the second stage operation. In group B, all the procedures were exactly the same as those in group A except that artificial dermis had been soaked in bFGF for 30 min before grafting. Operation area, complete vascularization time of artificial dermis, survival of skin grafts, and the follow-up condition of wounds in the two groups were recorded. Data were processed with t test and Fisher's exact test. (1) Operation areas of wounds after resection of cicatrices, deep burn wounds without exposure of tendon or bone, and wounds with exposure of small area of tendon or bone in the two groups were about the same (with t values from -1.853 to -0.200, P values above 0.05). Complete vascularization time of artificial dermis in wounds after resection of cicatrices, deep burn wounds without exposure of tendon or bone, and wounds with exposure of small area of tendon or bone in group B were respectively (15.6 ± 2.9), (14.7 ± 2.7), and (20.3 ± 4.4) d, and they were shorter by an

[The necessity of artificial kidney seeper in the ultrasonography-guided percutaneous nephrolithotomy: a randomized controlled study].

PubMed

Ye, J J; Yang, Y; Zhang, H J; Zheng, Y C; Pan, Y; Xie, H

2018-05-01

Objective: To investigate the necessity of artificial kidney seeper which made through inserting a ureteral tube in the ureter to the ultrasonography-guided percutaneous nephrolithotomy (PCNL). Methods: This was a randomized prospective study. Patients who conformed to the inclusion and exclusion criteria were enrolled at Department of Urology, Frist Affiliated Hospital of Wenzhou Medical University from January 2016 to May 2017. Totally 291 patients were included in the study. Patients were randomly assigned into two groups (artificial kidney seeper group and non-artificial kidney seeper group) in different kidney seeper level (5 to <10 mm, 10 to 20 mm) respectively. The artificial kidney seeper group was inserted by a ureteral cathedral, then were underwent the ultrasonography-guided PCNL in prone position. The non-artificial kidney seeper group were underwent the ultrasonography-guided PCNL in prone position directly. The t test, χ(2) test, repeated measure analysis was used to data measurement, respectively. Results: Four patients who diagnosed pyonephrosis were excluded. On the 5 to <10 mm level, fever rate (14.6% vs . 4.8%, χ(2)=5.07, P =0.03), operation time ((65.7±9.9)min vs . (50.3±7.4)min, t =11.47, P =0.00), cost ((18 327±903) yuan vs . (14 583±784) yuan, t =24.50, P =0.00) about artificial kidney seeper group and non-artificial kidney seeper group had statistical differences. And on the 10 to 20 mm level, fever rate (14.5% vs . 3.39%, χ(2)=4.53, P =0.03), operation time ((66.0±9.9)min vs . (52.4±8.9)min, t =8.30, P =0.00), cost ((16 548±537) yuan vs. (13 102±629) yuan, t =32.10, P =0.00) about artificial kidney seeper group and non-artificial kidney seeper group had statistical differences. And there were no statistical differences in the success rate of puncturing, the failures of the treatment to the stone pieces falling into the ureter and clearance rate of the stone and so on. In this study, 2 cases recovered after received transfusion

Improving artificial forest biomass estimates using afforestation age information from time series Landsat stacks.

PubMed

Liu, Liangyun; Peng, Dailiang; Wang, Zhihui; Hu, Yong

2014-11-01

China maintains the largest artificial forest area in the world. Studying the dynamic variation of forest biomass and carbon stock is important to the sustainable use of forest resources and understanding of the artificial forest carbon budget in China. In this study, we investigated the potential of Landsat time series stacks for aboveground biomass (AGB) estimation in Yulin District, a key region of the Three-North Shelter region of China. Firstly, the afforestation age was successfully retrieved from the Landsat time series stacks in the last 40 years (from 1974 to 2013) and shown to be consistent with the surveyed tree ages, with a root-mean-square error (RMSE) value of 4.32 years and a determination coefficient (R (2)) of 0.824. Then, the AGB regression models were successfully developed by integrating vegetation indices and tree age. The simple ratio vegetation index (SR) is the best candidate of the commonly used vegetation indices for estimating forest AGB, and the forest AGB model was significantly improved using the combination of SR and tree age, with R (2) values from 0.50 to 0.727. Finally, the forest AGB images were mapped at eight epochs from 1985 to 2013 using SR and afforestation age. The total forest AGB in seven counties of Yulin District increased by 20.8 G kg, from 5.8 G kg in 1986 to 26.6 G kg in 2013, a total increase of 360 %. For the persistent forest area since 1974, the forest AGB density increased from 15.72 t/ha in 1986 to 44.53 t/ha in 2013, with an annual rate of about 0.98 t/ha. For the artificial forest planted after 1974, the AGB density increased about 1.03 t/ha a year from 1974 to 2013. The results present a noticeable carbon increment for the planted artificial forest in Yulin District over the last four decades.

Isotropic Versus Bipolar Functionalized Biomimetic Artificial Basement Membranes and Their Evaluation in Long-Term Human Cell Co-Culture.

PubMed

Rossi, Angela; Wistlich, Laura; Heffels, Karl-Heinz; Walles, Heike; Groll, Jürgen

2016-08-01

In addition to dividing tissues into compartments, basement membranes are crucial as cell substrates and to regulate cellular behavior. The development of artificial basement membranes is indispensable for the ultimate formation of functional engineered tissues; however, pose a challenge due to their complex structure. Herein, biodegradable electrospun polyester meshes are presented, exhibiting isotropic or bipolar bioactivation as a biomimetic and biofunctional model of the natural basement membrane. In a one-step preparation process, reactive star-shaped prepolymer additives, which generate a hydrophilic fiber surface, are electrospun with cell-adhesion-mediating peptides, derived from major components of the basement membrane. Human skin cells adhere to the functionalized meshes, and long-term co-culture experiments confirm that the artificial basement membranes recapitulate and preserve tissue specific functions. Several layers of immortalized human keratinocytes grow on the membranes, differentiating toward the surface and expressing typical epithelial markers. Fibroblasts migrate into the reticular lamina mimicking part of the mesh. Both cells types begin to produce extracellular matrix proteins and to remodel the initial membrane. It is shown at the example of skin that the artificial basement membrane design provokes biomimetic responses of different cell types and can thus be used as basis for the future development of basement membrane containing tissues. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Hybridized 1T/2H MoS2 Having Controlled 1T Concentrations and its use in Supercapacitors.

PubMed

Thi Xuyen, Nguyen; Ting, Jyh-Ming

2017-12-06

Molybdenum disulfide (MoS 2 ) nanoflowers consisting of hybridized 1T/2H phases have been synthesized by using a microwave-assisted hydrothermal (MTH) method. The concentration of the 1T phase, ranging from 40 % to 73 %, is controlled by simply adjusting the ratio of the Mo and S precursors. By using the hybridized 1T/2H MoS 2 as an electrode material, it was demonstrated that the resulting supercapacitor performance is dominated by the 1T phase concentration. It was found that a supercapacitor with 73 % 1T phase exhibits excellent capacitance of 259 F g -1 and great cyclic stability after 1000 cycles. The formation mechanism of the MHT-synthesized hybridized 1T/2H MoS 2 is also reported. More importantly, the mechanism also explains the observed relationship between the 1T phase concentration and the ratio of the Mo and S precursors. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Methionine Regulates mTORC1 via the T1R1/T1R3-PLCβ-Ca2+-ERK1/2 Signal Transduction Process in C2C12 Cells.

PubMed

Zhou, Yuanfei; Ren, Jiao; Song, Tongxing; Peng, Jian; Wei, Hongkui

2016-10-11

The mammalian target of rapamycin complex 1 (mTORC1) integrates amino acid (AA) availability to support protein synthesis and cell growth. Taste receptor type 1 member (T1R) is a G protein-coupled receptor that functions as a direct sensor of extracellular AA availability to regulate mTORC1 through Ca 2+ stimulation and extracellular signal-regulated kinases 1 and 2 (ERK1/2) activation. However, the roles of specific AAs in T1R1/T1R3-regulated mTORC1 are poorly defined. In this study, T1R1 and T1R3 subunits were expressed in C2C12 myotubes, and l-AA sensing was accomplished by T1R1/T1R3 to activate mTORC1. In response to l-AAs, such as serine (Ser), arginine (Arg), threonine (Thr), alanine (Ala), methionine (Met), glutamine (Gln), and glycine (Gly), Met induced mTORC1 activation and promoted protein synthesis. Met also regulated mTORC1 via T1R1/T1R3-PLCβ-Ca 2+ -ERK1/2 signal transduction. Results revealed a new role for Met-regulated mTORC1 via an AA receptor. Further studies should be performed to determine the role of T1R1/T1R3 in mediating extracellular AA to regulate mTOR signaling and to reveal its mechanism.

Knowledge Based Simulation: An Artificial Intelligence Approach to System Modeling and Automating the Simulation Life Cycle.

DTIC Science & Technology

1988-04-13

Simulation: An Artificial Intelligence Approach to System Modeling and Automating the Simulation Life Cycle Mark S. Fox, Nizwer Husain, Malcolm...McRoberts and Y.V.Reddy CMU-RI-TR-88-5 Intelligent Systems Laboratory The Robotics Institute Carnegie Mellon University Pittsburgh, Pennsylvania D T T 13...years of research in the application of Artificial Intelligence to Simulation. Our focus has been in two areas: the use of Al knowledge representation

T1 hyperintense disc in alkaptonuria.

PubMed

Sag, Alan A; Silbergleit, Richard; Olson, Rick E; Wilson, Jon; Krishnan, Anant

2012-10-01

Case report. To report a rare case of alkaptonuria presenting as a T1-hyperintense disc herniation. A 46-year-old man without previous diagnosis of alkaptonuria underwent evaluation for progressive back pain revealing a T1-hyperintense disc herniation at the L3-L4 level. Discectomy recovered a blackened disc that was pathologically confirmed to be nucleus pulposus with alkaptonuric involvement. The differential diagnosis of a T1-hyperintense, T2-hypointense disc on magnetic resonance imaging is discussed, with emphasis on the pathophysiology of alkaptonuria. A single patient is reported. Pathologically proven patient presentation with radiological and pathological images. We report a rare case of alkaptonuria presenting as a T1-hyperintense disc herniation.

Autonomous self-configuration of artificial neural networks for data classification or system control

NASA Astrophysics Data System (ADS)

Fink, Wolfgang

2009-05-01

Artificial neural networks (ANNs) are powerful methods for the classification of multi-dimensional data as well as for the control of dynamic systems. In general terms, ANNs consist of neurons that are, e.g., arranged in layers and interconnected by real-valued or binary neural couplings or weights. ANNs try mimicking the processing taking place in biological brains. The classification and generalization capabilities of ANNs are given by the interconnection architecture and the coupling strengths. To perform a certain classification or control task with a particular ANN architecture (i.e., number of neurons, number of layers, etc.), the inter-neuron couplings and their accordant coupling strengths must be determined (1) either by a priori design (i.e., manually) or (2) using training algorithms such as error back-propagation. The more complex the classification or control task, the less obvious it is how to determine an a priori design of an ANN, and, as a consequence, the architecture choice becomes somewhat arbitrary. Furthermore, rather than being able to determine for a given architecture directly the corresponding coupling strengths necessary to perform the classification or control task, these have to be obtained/learned through training of the ANN on test data. We report on the use of a Stochastic Optimization Framework (SOF; Fink, SPIE 2008) for the autonomous self-configuration of Artificial Neural Networks (i.e., the determination of number of hidden layers, number of neurons per hidden layer, interconnections between neurons, and respective coupling strengths) for performing classification or control tasks. This may provide an approach towards cognizant and self-adapting computing architectures and systems.

Rheumatic mitral valve stenosis mimicking advanced lung cancer.

PubMed

von Lueder, Thomas; Steine, Kjetil; Nerdrum, Tone; Steen, Torkel; Bay, Dag; Humerfelt, Sjur; Atar, Dan

2007-09-01

This report describes a patient with a perihilar mass and mediastinal lymphadenopathy mimicking advanced lung cancer. The patient, a 45-year old regular smoker, was admitted to hospital for dyspnea and tachyarrhythmia, and during hospitalization he was diagnosed with severe rheumatic mitral valve stenosis (MVS) and aortic regurgitation as well as pulmonary venous hypertension. Surgical valve replacement and removal of an atrial thrombus was delayed considerably by diagnostic work-up for suspected malignancy. After cardiac surgery had been performed, recovery was uneventful. On follow-up 1 year later, echocardiography showed well-functioning prosthetic mitral and aortic valves, and normal findings on chest X-ray. Perihilar masses and mediastinal lymphadenopathy presented in this case constitute infrequent yet established findings in MVS, resulting from pulmonary venous congestion and hypertension, and focal lymphedema.

Biological and Nano-Technological Applications of Artificial DNAs Made Exclusively of Nonnatural C-Nucleosides with Four Types of Nonnatural Bases

DTIC Science & Technology

2011-08-19

A) CD, (B) UV, (C) Tm, and (D) titration experiments of d(iG*)8/d(C)8. d(T/A*/T)n WC WC
 d(T/A/T)n Watson – Crick (WC)
 Hoogsteen
 Symmetrical A...base Figure 7. Triplex formation of the natural T/A/T which has one Watson - Crick (WC)-type and one Hoogsteen-type hydrogen-bondings, and the...Final Report for AOARD Grant FA2386-10-1-4033 “Biological and Nano-technological Applications of Artificial DNAs Made Exclusively of Nonnatutal C

Epidermal cyst mimicking incision line metastasis

PubMed Central

Gündoğdu, Ramazan; Ayhan, Erhan; Çolak, Tahsin

2017-01-01

Epidermal cysts are cystic tumors lined with keratinized squamous layer and filled with keratin debris. Epidermal cysts may develop by implantation of surface epidermal layer into the dermis or subcutaneous tissue after trauma or surgical procedures. Cervix cancer spreads either directly or via the vascular and lymphatic systems. Distant skin metastasis of endometrium or cervix cancer is very rare. In this case report, a patient who had a history of cervix cancer operation 11 years ago and presented with a mass that mimicked incision line metastasis and was histopathologically diagnosed with epidermal cyst is presented. PMID:28740968

Modeling Training Site Vegetation Coverage Probability with a Random Optimizing Procedure: An Artificial Neural Network Approach.

DTIC Science & Technology

1998-05-01

Coverage Probability with a Random Optimization Procedure: An Artificial Neural Network Approach by Biing T. Guan, George Z. Gertner, and Alan B...Modeling Training Site Vegetation Coverage Probability with a Random Optimizing Procedure: An Artificial Neural Network Approach 6. AUTHOR(S) Biing...coverage based on past coverage. Approach A literature survey was conducted to identify artificial neural network analysis techniques applicable for

Prediction and Measurement of Temperature Rise Induced by High Intensity Focused Ultrasound in a Tissue-Mimicking Phantom

NASA Astrophysics Data System (ADS)

Lee, Kang Il

2018-06-01

The present study aims to predict the temperature rise induced by high intensity focused ultrasound (HIFU) in soft tissues to assess tissue damage during HIFU thermal therapies. With the help of a MATLAB-based software package developed for HIFU simulation, the HIFU field was simulated by solving the axisymmetric Khokhlov-Zabolotskaya-Kuznetsov (KZK) equation from the frequency-domain perspective, and the HIFU-induced temperature rise in a tissue-mimicking phantom was simulated by solving Pennes' bioheat transfer (BHT) equation. In order to verify the simulation results, we performed in-vitro heating experiments on a tissue-mimicking phantom by using a 1.1-MHz, single-element, spherically focused HIFU transducer. The temperature rise near the focal spot obtained from the HIFU simulator was in good agreement with that from the in-vitro experiments. This confirms that the HIFU simulator based on the KZK and the BHT equations captures the HIFU-induced temperature rise in soft tissues well enough to make it suitable for HIFU treatment planning.

Perioperative Prophylaxis for Total Artificial Heart Transplantation.

PubMed

Chambers, H E; Pelish, P; Qiu, F; Florescu, D F

2017-11-01

Practice variation regarding perioperative antimicrobial prophylaxis in total artificial heart transplantations (TAH-t) across institutions is unknown. The aim of our survey was to assess the current practices for prevention of infection in TAH-t recipients among different programs. An electronic survey was sent to programs that implant Syncardia TAH (Syncardia Systems, Tuscon, Ariz, USA). Proportions were analyzed for categorical variables; means and SDs were analyzed for continuous variables. The majority of centers (80.8%) had a formal surgical infection prophylaxis protocol. For non-penicillin-allergic patients, five (20.1%) institutions reported using a 4-drug regimen, seven (29.2%) used a 3-drug regimen, five (20.1%) used a 2-drug regimen, and seven (29.2%) used a cephalosporin alone. Similar data was seen in the penicillin-allergic patients. Infections were reported to occur postoperatively in 52.2% centers. During the first month after TAH-t, bacteremia represented 27.3%, driveline infections 27.2%, pulmonary infections 9%, and mediastinal infections 18.2%. The most common organisms seen within the first month were Candida spp., Escherichia coli, and Pseudomonas aeruginosa (21.4%). In 65% of centers, the mean rate of death post-TAH-t due to infection was 14.5% (SD, 22.3%). The mean rate of patients surviving until orthotopic heart transplantation was 58.6% (SD, 27.7%). Preventing infections post-TAH-t is key to decreasing morbidity and mortality. All institutions administered perioperative prophylaxis for TAH-t with significant variation among the centers. The majority of the centers have a formal perioperative prophylactic protocol. Copyright © 2017. Published by Elsevier Inc.

[Preparation of nano-nacre artificial bone].

PubMed

Chen, Jian-ting; Tang, Yong-zhi; Zhang, Jian-gang; Wang, Jian-jun; Xiao, Ying

2008-12-01

To assess the improvements in the properties of nano-nacre artificial bone prepared on the basis of nacre/polylactide acid composite artificial bone and its potential for clinical use. The compound of nano-scale nacre powder and poly-D, L-lactide acid (PDLLA) was used to prepare the cylindrical hollow artificial bone, whose properties including raw material powder scale, pore size, porosity and biomechanical characteristics were compared with another artificial bone made of micron-scale nacre powder and PDLLA. Scanning electron microscope showed that the average particle size of the nano-nacre powder was 50.4-/+12.4 nm, and the average pore size of the artificial bone prepared using nano-nacre powder was 215.7-/+77.5 microm, as compared with the particle size of the micron-scale nacre powder of 5.0-/+3.0 microm and the pore size of the resultant artificial bone of 205.1-/+72.0 microm. The porosities of nano-nacre artificial bone and the micron-nacre artificial bone were (65.4-/+2.9)% and (53.4-/+2.2)%, respectively, and the two artificial bones had comparable compressive strength and Young's modulus, but the flexural strength of the nano-nacre artificial bone was lower than that of the micro-nacre artificial bone. The nano-nacre artificial bone allows better biodegradability and possesses appropriate pore size, porosity and biomechanical properties for use as a promising material in bone tissue engineering.

Measurement of T1 of human arterial and venous blood at 7T.

PubMed

Rane, Swati D; Gore, John C

2013-04-01

Techniques for measuring cerebral perfusion require accurate longitudinal relaxation (T1) of blood, an MRI parameter that is field dependent. T1 of arterial and venous human blood was measured at 7T using three different sources - pathology laboratory, blood bank and in vivo. The T1 of venous blood was measured from sealed samples from a pathology lab and in vivo. Samples from a blood bank were oxygenated and mixed to obtain different physiological concentrations of hematocrit and oxygenation. T1 relaxation times were estimated using a three-point fit to a simple inversion recovery equation. At 37°C, the T1 of blood at arterial pO2 was 2.29±0.1s and 2.07±0.12 at venous pO2. The in vivo T1 of venous blood, in three subjects, was slightly longer at 2.45±0.11s. T1 of arterial and venous blood at 7T was measured and found to be significantly different. The T1 values were longer in vivo than in vitro. While the exact cause for the discrepancy is unknown, the additives in the blood samples, degradation during experiment, oxygenation differences, and the non-stagnant nature of blood in vivo could be potential contributors to the lower values of T1 in the venous samples. Copyright © 2013 Elsevier Inc. All rights reserved.

Influence of MC3T3-E1 preosteoblast culture on the corrosion of a T6-treated AZ91 alloy

PubMed Central

Brooks, Emily K.; Tobias, Menachem E.; Yang, Shuying; Bone, Lawrence B.; Ehrensberger, Mark T.

2015-01-01

This study investigated the corrosion of artificially aged T6 heat-treated Mg-9%Al-1%Zn (AZ91) for biomedical applications. Corrosion tests and surface analysis were completed both with and without a monolayer of mouse preosteoblast MC3T3-E1 cells cultured on the sample. Electrochemical impedance spectroscopy (EIS) and inductively coupled plasma mass spectroscopy (ICPMS) were used to explore the corrosion processes after either 3 or 21 days of AZ91 incubation in cell culture medium (CCM). The EIS showed both the inner layer resistance (Rin) and outer layer resistance (Rout) were lower for samples without cells cultured on the surface at 3 days (Rin = 2.64 e4 Ω/cm2, Rout = 140 Ω/cm2) compared to 21 days (Rin = 3.60 e4 Ω/cm2, Rout = 287 Ω/cm2) due to precipitation of magnesium and calcium phosphates over time. Samples with preosteoblasts cultured on the surface had a slower initial corrosion (3 day, Rin = 1.88 e5 Ω/cm2, Rout = 1060 Ω/cm2) which was observed to increase over time (21 day, Rin = 2.99 e4 Ω/cm2, Rout = 287 Ω/cm2). Changes in the corrosion processes were thought to be related to changes in the coverage provided by the cell layer. Our results reveal that the presence of cells and biological processes are able to significantly influence the corrosion rate of AZ91. PMID:25715925

Adefovir-Induced Hypophosphatemic Osteomalacia Mimicking Bone Metastases From Primary Hepatocarcinoma.

PubMed

Wei, Wei-Jun; Sun, Zhen-Kui; Shen, Chen-Tian; Qiu, Zhong-Ling; Luo, Quan-Yong

2017-09-01

Adefovir-induced hypophosphatemic osteomalacia in the context of hepatocarcinoma is rare and needs to be differentiated from metastatic hepatocarcinoma. We here report a case of severe osteomalacia whose focal uptakes of radiotracer on the Tc-MDP SPECT/CT images mimicked that of metastatic hepatocarcinoma.

Analysis of the frontier technology of agricultural IoT and its predication research

NASA Astrophysics Data System (ADS)

Han, Shuqing; Zhang, Jianhua; Zhu, Mengshuai; Wu, Jianzhai; Shen, Chen; Kong, Fantao

2017-09-01

Agricultural IoT (Internet of Things) develops rapidly. Nanotechnology, biotechnology and optoelectronic technology are successfully integrated into the agricultural sensor technology. Big data, cloud computing and artificial intelligence technology have also been successfully used in IoT. This paper carries out the research on integration of agricultural sensor technology, nanotechnology, biotechnology and optoelectronic technology and the application of big data, cloud computing and artificial intelligence technology in agricultural IoT. The advantages and development of the integration of nanotechnology, biotechnology and optoelectronic technology with agricultural sensor technology were discussed. The application of big data, cloud computing and artificial intelligence technology in IoT and their development trend were analysed.

Improved artificial saliva for studying the cariogenic effect of carbohydrates.

PubMed

Björklund, Marika; Ouwehand, Arthur C; Forssten, Sofia D

2011-07-01

Saliva is a complex fluid that possesses many important functions regarding oral health. Many in vitro studies require relatively large quantities of saliva. While natural saliva would be the material of choice, it is difficult to obtain in sufficient quantities and varies in composition. Substitutes mimicking the physicochemical properties of saliva have been developed, but these are not appropriate to study the growth of mutans streptococci. Brain Heart Infusion (BHI) has been commonly used for this, but this medium is richer in nutrients than saliva. We therefore developed artificial saliva (AS) with nutrient levels resembling those in natural saliva as a substitute for natural human saliva (HS) to study the influence of different carbon sources on mutans streptococci growth. Growth of a wild-type Streptococcus mutans strain and S. mutans ATCC 15175 in BHI, HS, and AS was monitored anaerobically. Growth of S. mutans in the modified AS was very similar to the growth in HS, both in the absence and presence of different carbon sources. We therefore conclude that the developed AS is suitable for in vitro tests on S. mutans growth.

Acute Fulminant Uremic Neuropathy Following Coronary Angiography Mimicking Guillain-Barre Syndrome.

PubMed

Priti, Kumari; Ranwa, Bhanwar

2017-01-01

A 55-year-old diabetic woman suffered a posterior wall ST-elevation myocardial infarction. She developed contrast-induced nephropathy following coronary angiography. Acute fulminant uremic neuropathy was precipitated which initially mimicked Guillan-Barre Syndrome, hence reported.

Moderately nonlinear ultrasound propagation in blood-mimicking fluid.

PubMed

Kharin, Nikolay A; Vince, D Geoffrey

2004-04-01

In medical diagnostic ultrasound (US), higher than-in-water nonlinearity of body fluids and tissue usually does not produce strong nonlinearly distorted waves because of the high absorption. The relative influence of absorption and nonlinearity can be characterized by the Gol'dberg number Gamma. There are two limiting cases in nonlinear acoustics: weak waves (Gamma < 1) or strong waves (Gamma > 1). However, at diagnostic frequencies in tissue and body fluids, the nonlinear effects and effects of absorption more likely are comparable (Gol'dberg number Gamma approximately 1). The aim of this work was to study the nonlinear propagation of a moderately nonlinear US second harmonic signal in a blood-mimicking fluid. Quasilinear solutions to the KZK equation are presented, assuming radiation from a flat and geometrically focused circular Gaussian source. The solutions are expressed in a new simplified closed form and are in very good agreement with those of previous studies measuring and modeling Gaussian beams. The solutions also show good agreement with the measurements of the beams produced by commercially available transducers, even without special Gaussian shading.

Expression of activating natural killer-cell receptors is a hallmark of the innate-like T-cell neoplasm in peripheral T-cell lymphomas.

PubMed

Uemura, Yu; Isobe, Yasushi; Uchida, Akiko; Asano, Junko; Nishio, Yuji; Sakai, Hirotaka; Hoshikawa, Masahiro; Takagi, Masayuki; Nakamura, Naoya; Miura, Ikuo

2018-04-01

Peripheral T- or natural killer (NK)-cell lymphomas are rare and difficult-to-recognize diseases. It remains arduous to distinguish between NK cell- and cytotoxic T-lymphocyte-derived lymphomas through routine histological evaluation. To clarify the cells of origin, we focused on NK-cell receptors and examined the expression using immunohistochemistry in 22 cases with T- and NK-cell neoplasms comprising angioimmunoblastic T-cell lymphoma, anaplastic lymphoma kinase (ALK)-positive and -negative anaplastic large-cell lymphomas, extranodal NK/T-cell lymphoma, nasal type, monomorphic epitheliotropic intestinal T-cell lymphoma, aggressive NK-cell leukemia, and other peripheral T-cell lymphomas. Inhibitory receptor leukocyte immunoglobulin-like receptor subfamily B member 1 (LILRB1) was detected in 14 (64%) cases, whereas activating receptors DNAM1, NKp46, and NKG2D were expressed in 7 (32%), 9 (41%), and 5 (23%) cases, respectively. Although LILRB1 was detected regardless of the disease entity, the activating NK-cell receptors were expressed predominantly in TIA-1-positive neoplasms (DNAM1, 49%; NKp46, 69%; and NKG2D, 38%). In addition, NKp46 and NKG2D were detected only in NK-cell neoplasms and cytotoxic T-lymphocyte-derived lymphomas including monomorphic epitheliotropic intestinal T-cell lymphoma. One Epstein-Barr virus-harboring cytotoxic T-lymphocyte-derived lymphoma mimicking extranodal NK/T-cell lymphoma, nasal type lacked these NK-cell receptors, indicating different cell origin from NK and innate-like T cells. Furthermore, NKG2D expression showed a negative impact on survival among the 22 examined cases, which mainly received the standard chemotherapy regimen (log-rank test, P = .024). We propose that the presence of activating NK-cell receptors may provide new insights into understanding peripheral T-cell lymphomas and characterizing them as innate-like T-cell neoplasm. © 2018 The Authors. Cancer Science published by John Wiley & Sons Australia, Ltd on

Exercise and the Development of the Artificial Pancreas

PubMed Central

Riddell, Michael C.; Zaharieva, Dessi P.; Yavelberg, Loren; Cinar, Ali; Jamnik, Veronica K.

2015-01-01

Regular physical activity (PA) promotes numerous health benefits for people living with type 1 diabetes (T1D). However, PA also complicates blood glucose control. Factors affecting blood glucose fluctuations during PA include activity type, intensity and duration as well as the amount of insulin and food in the body at the time of the activity. To maintain equilibrium with blood glucose concentrations during PA, the rate of glucose appearance (Ra) to disappearance (Rd) in the bloodstream must be balanced. In nondiabetics, there is a rise in glucagon and a reduction in insulin release at the onset of mild to moderate aerobic PA. During intense aerobic -anaerobic work, insulin release first decreases and then rises rapidly in early recovery to offset a more dramatic increase in counterregulatory hormones and metabolites. An “exercise smart” artificial pancreas (AP) must be capable of sensing glucose and perhaps other physiological responses to various types and intensities of PA. The emergence of this new technology may benefit active persons with T1D who are prone to hypo and hyperglycemia. PMID:26428933

Characterization of a Piezoelectric AlN Beam Array in Air and Fluid for an Artificial Basilar Membrane

NASA Astrophysics Data System (ADS)

Jeon, Hyejin; Jang, Jongmoon; Kim, Sangwon; Choi, Hongsoo

2018-03-01

In this study, we present a piezoelectric artificial basilar membrane (ABM) composed of a 10-channel aluminum nitride beam array. Each beam varies in length from 1306 to 3194 μm for mimicking the frequency selectivity of the cochlea. To characterize the frequency selectivity of the ABM, we measured the mechanical displacement and piezoelectric output while applying acoustic stimulus at 100 dB sound pressure level in the range of 500 Hz-40 kHz. The resonance frequencies measured by mechanical displacement and piezoelectric output were in the range of 10.56-36.5 and 10.9-37.0 kHz, respectively. In addition, the electrical stimulus was applied to the ABMs to compare the mechanical responses in air and fluid. The measured resonance frequencies were in the range of 11.1-47.7 kHz in the air and 3.10-11.9 kHz in the fluid. Understanding the characteristics of the ABM is important for its potential use as a key technology for auditory prostheses.

Contrast-enhanced 3T MR Perfusion of Musculoskeletal Tumours: T1 Value Heterogeneity Assessment and Evaluation of the Influence of T1 Estimation Methods on Quantitative Parameters.

PubMed

Gondim Teixeira, Pedro Augusto; Leplat, Christophe; Chen, Bailiang; De Verbizier, Jacques; Beaumont, Marine; Badr, Sammy; Cotten, Anne; Blum, Alain

2017-12-01

To evaluate intra-tumour and striated muscle T1 value heterogeneity and the influence of different methods of T1 estimation on the variability of quantitative perfusion parameters. Eighty-two patients with a histologically confirmed musculoskeletal tumour were prospectively included in this study and, with ethics committee approval, underwent contrast-enhanced MR perfusion and T1 mapping. T1 value variations in viable tumour areas and in normal-appearing striated muscle were assessed. In 20 cases, normal muscle perfusion parameters were calculated using three different methods: signal based and gadolinium concentration based on fixed and variable T1 values. Tumour and normal muscle T1 values were significantly different (p = 0.0008). T1 value heterogeneity was higher in tumours than in normal muscle (variation of 19.8% versus 13%). The T1 estimation method had a considerable influence on the variability of perfusion parameters. Fixed T1 values yielded higher coefficients of variation than variable T1 values (mean 109.6 ± 41.8% and 58.3 ± 14.1% respectively). Area under the curve was the least variable parameter (36%). T1 values in musculoskeletal tumours are significantly different and more heterogeneous than normal muscle. Patient-specific T1 estimation is needed for direct inter-patient comparison of perfusion parameters. • T1 value variation in musculoskeletal tumours is considerable. • T1 values in muscle and tumours are significantly different. • Patient-specific T1 estimation is needed for comparison of inter-patient perfusion parameters. • Technical variation is higher in permeability than semiquantitative perfusion parameters.

Comparison of contrast-enhanced T1-weighted FLAIR with BLADE, and spin-echo T1-weighted sequences in intracranial MRI.

PubMed

Alkan, Ozlem; Kizilkiliç, Osman; Yildirim, Tülin; Alibek, Sedat

2009-06-01

We compared periodically rotated overlapping parallel lines with enhanced reconstruction (PROPELLER, BLADE) MR technique with spin echo (SE) technique for evaluation of artifacts, and detection and delineation of brain lesions. Contrast-enhanced T1-weighted fluid attenuated inversion recovery (FLAIR) images with BLADE technique (CE T1W-FLAIR BLADE) and contrast-enhanced T1-weighted SE (CE T1W-SE) were performed in 50 patients with intracranial enhancing lesions. These techniques were compared by two neuroradiologists for qualitative analysis of artifacts, lesion detectability, lesion delineation from adjacent structures, and preferred imaging technique; and for quantitative variables, i.e., lesion-to-background and lesion-to-cerebrospinal fluid (CSF) contrast-to-noise (CNR) ratios. Reader agreement was assessed by kappa statistics. All lesions depicted with the CE T1W-SE were also detected with the CE T1W-FLAIR BLADE technique. Delineation of lesions was better on CE T1W-FLAIR BLADE in the majority of patients. Flow-related artifacts were considerably reduced with CE T1W-FLAIR BLADE. A star-like artifact at the level of the 4(th) ventricle was noted on CE T1W-FLAIR BLADE but not on CE T1W-SE. The lesion-to-background CNR and lesion-to-CSF CNR did not show a statistically significant difference between the two techniques. CE T1W-FLAIR BLADE images were preferred by the observers over the CE T1w-SE images, indicating good interobserver agreement (k = 0.70). CE T1W-FLAIR BLADE technique is superior to CE T1WSE for delineation of lesions and reduction of flow-related artifacts, especially within the posterior fossa, and is preferred by readers. CE T1W-FLAIR BLADE may be an alternative approach to imaging, especially for posterior fossa lesions.

Heparin-mimicking multilayer coating on polymeric membrane via LbL assembly of cyclodextrin-based supramolecules.

PubMed

Deng, Jie; Liu, Xinyue; Ma, Lang; Cheng, Chong; Shi, Wenbin; Nie, Chuanxiong; Zhao, Changsheng

2014-12-10

In this study, multifunctional and heparin-mimicking star-shaped supramolecules-deposited 3D porous multilayer films with improved biocompatibility were fabricated via a layer-by-layer (LbL) self-assembly method on polymeric membrane substrates. Star-shaped heparin-mimicking polyanions (including poly(styrenesulfonate-co-sodium acrylate; Star-PSS-AANa) and poly(styrenesulfonate-co-poly(ethylene glycol)methyl ether methacrylate; Star-PSS-EGMA)) and polycations (poly(methyl chloride-quaternized 2-(dimethylamino)ethyl methacrylate; Star-PMeDMA) were first synthesized by atom transfer radical polymerization (ATRP) from β-cyclodextrin (β-CD) based cores. Then assembly of 3D porous multilayers onto polymeric membrane surfaces was carried out by alternating deposition of the polyanions and polycations via electrostatic interaction. The surface morphology and composition, water contact angle, blood activation, and thrombotic potential as well as cell viability for the coated heparin-mimicking films were systematically investigated. The results of surface ATR-FTIR spectra and XPS spectra verified successful deposition of the star-shaped supramolecules onto the biomedical membrane surfaces; scanning electron microscopy (SEM) and atomic force microscopy (AFM) observations revealed that the modified substrate had 3D porous surface morphology, which might have a great biological influence on the biointerface. Furthermore, systematic in vitro investigation of protein adsorption, platelet adhesion, human platelet factor 4 (PF4, indicates platelet activation), activate partial thromboplastin time (APTT), thrombin time (TT), coagulation activation (thrombin-antithrombin III complex (TAT, indicates blood coagulant)), and blood-related complement activation (C3a and C5a, indicates inflammation potential) confirmed that the heparin-mimicking multilayer coated membranes exhibited ultralow blood component activations and excellent hemocompatibility. Meanwhile, after surface coating

Taste responses in mice lacking taste receptor subunit T1R1

PubMed Central

Kusuhara, Yoko; Yoshida, Ryusuke; Ohkuri, Tadahiro; Yasumatsu, Keiko; Voigt, Anja; Hübner, Sandra; Maeda, Katsumasa; Boehm, Ulrich; Meyerhof, Wolfgang; Ninomiya, Yuzo

2013-01-01

The T1R1 receptor subunit acts as an umami taste receptor in combination with its partner, T1R3. In addition, metabotropic glutamate receptors (brain and taste variants of mGluR1 and mGluR4) are thought to function as umami taste receptors. To elucidate the function of T1R1 and the contribution of mGluRs to umami taste detection in vivo, we used newly developed knock-out (T1R1−/−) mice, which lack the entire coding region of the Tas1r1 gene and express mCherry in T1R1-expressing cells. Gustatory nerve recordings demonstrated that T1R1−/− mice exhibited a serious deficit in inosine monophosphate-elicited synergy but substantial residual responses to glutamate alone in both chorda tympani and glossopharyngeal nerves. Interestingly, chorda tympani nerve responses to sweeteners were smaller in T1R1−/− mice. Taste cell recordings demonstrated that many mCherry-expressing taste cells in T1R1+/− mice responded to sweet and umami compounds, whereas those in T1R1−/− mice responded to sweet stimuli. The proportion of sweet-responsive cells was smaller in T1R1−/− than in T1R1+/− mice. Single-cell RT-PCR demonstrated that some single mCherry-expressing cells expressed all three T1R subunits. Chorda tympani and glossopharyngeal nerve responses to glutamate were significantly inhibited by addition of mGluR antagonists in both T1R1−/− and T1R1+/− mice. Conditioned taste aversion tests demonstrated that both T1R1−/− and T1R1+/− mice were equally capable of discriminating glutamate from other basic taste stimuli. Avoidance conditioned to glutamate was significantly reduced by addition of mGluR antagonists. These results suggest that T1R1-expressing cells mainly contribute to umami taste synergism and partly to sweet sensitivity and that mGluRs are involved in the detection of umami compounds. PMID:23339178

Neglected foreign body aspiration mimicking bronchial carcinoma.

PubMed

Afghani, Reza; Khandashpour Ghomi, Mahmoud; Khandoozi, Seyed Reza; Yari, Behrouz

2016-07-01

Foreign body aspiration can occur in any age group, but it is more commonly seen in children. In adults, there is usually a predisposing condition that poses a risk of aspiration. If aspiration occurs, prompt diagnosis and extraction of the foreign body is needed to prevent early and late complications. We report a rare case of neglected foreign body aspiration in a 45-year-old schizophrenic opium addicted patient, which resulted in an occlusive lesion in the bronchus, mimicking bronchial carcinoma. © The Author(s) 2016.

Demodex folliculitis mimicking acute graft-vs-host disease.

PubMed

Cotliar, Jonathan; Frankfurt, Olga

2013-12-01

Acute graft-vs-host disease (GVHD) typically requires high-dose systemic steroids as first-line treatment. Like drug eruptions, viral exanthema, and toxic erythema of chemotherapy, Demodex folliculitis is a clinical mimicker of acute GVHD and requires nonimmunosuppressive therapy. This case of Demodex folliculitis mimicking acute GVHD highlights the need for skin biopsy in patients who have undergone a stem cell transplant with eruptions on the head and neck. A 46-year-old white woman with a history of Fms-like tyrosine kinase 3 acute myeloid leukemia presented to the dermatology clinic with a 5-day history of a nonpruritic eruption on her face and neck 28 days after undergoing a double umbilical cord blood hematopoietic stem cell transplant (HSCT). Findings from the skin biopsy demonstrated a deep dermal lymphocytic infiltrate adjacent to follicular units along with an abundance of Demodex mites noted within the hair follicles consistent with Demodex folliculitis. Oral ivermectin, 12 mg, was given, and the eruption cleared within 24 hours. To our knowledge, this is only the fifth reported case of Demodex folliculitis following HSCT, but the first ever reported to be successfully treated with oral ivermectin. Demodex folliculitis should be added to the differential diagnosis of skin eruptions that arise after HSCT.

Acute Fulminant Uremic Neuropathy Following Coronary Angiography Mimicking Guillain–Barre Syndrome

PubMed Central

Priti, Kumari; Ranwa, Bhanwar

2017-01-01

A 55-year-old diabetic woman suffered a posterior wall ST-elevation myocardial infarction. She developed contrast-induced nephropathy following coronary angiography. Acute fulminant uremic neuropathy was precipitated which initially mimicked Guillan–Barre Syndrome, hence reported. PMID:28706599

In vitro comparison of intracranial stent visibility using various concentrations of gadolinium contrast agent under 1.5 T and 3 T MR angiography.

PubMed

Chiang, Chen-Hua; Tseng, Ying-Chi; Chen, Ai-Chi; Huang, Yen-Lin; Chen, David Yen-Ting; Chen, Chi-Jen; Lin, Yen-Kuang; Hsu, Hui-Ling

2017-04-01

MR angiography (MRA) is an increasingly used evaluation method following intracranial stenting. However, the various artifacts created by the stent limit this technique. The purpose of this study was to investigate the effects of various concentrations of gadolinium contrast agent on the visibility and signal characteristics of two stents using the a contrast enhanced MRA technique. Two intracranial stents (Enterprise and Helistent) were placed in polyvinyl chloride tubes as vascular phantoms. They were filled with six different doses of gadolinium contrast agent (1.0, 2.0, 4.0, 6.0, 8.0, and 10.0 mmol/L dimeglumine gadopentetate, respectively) and imaged using 3 T and 1.5 T MR systems. Relative in-stent signal (RIS) was calculated and artificial luminal narrowing (ALN) was obtained using pixel by pixel analysis. The Enterprise stent, performed in both 1.5 T and 3 T MR systems, showed mean RIS values much less than those for the Helistent for all different doses of gadolinium solution. Increased gadolinium concentration resulted in a gradual reduction in RIS values in the Enterprise group. Also, ALN in the Enterprise group showed no or little change with various gadolinium doses. The Enterprise stent demonstrated good luminal visibility regardless of gadolinium concentration. The relative in-stent signals were more predictable in the Enterprise stent with various doses of gadolinium. Therefore, the Enterprise stent has been shown to provide better in-stent visibility compared with the Helistent using various gadolinium doses. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Fibromatosis of the breast mimicking an abscess: case report of unusual sonographic features.

PubMed

Lee, So Min; Lee, Ji Young; Lee, Byung Hoon; Kim, Su Young; Joo, Mee; Kim, Jae Il

2015-01-01

Fibromatosis of the breast, also known as a desmoid tumor, is extremely rare and most often appears as an aggressive lesion mimicking breast carcinoma. It lacks metastatic potential but can grow aggressively in a localized area. Ultrasonography often shows an irregular spiculated hypoechoic mass with posterior acoustic shadowing. We discuss a case of breast fibromatosis that presented as a painful palpable breast mass in a 32-year-old woman and mimicked an abscess in the sonogram. We found that this lesion displayed atypical sonographic features such as a heterogeneous echoic mass with an internal anechoic area. Copyright © 2015 Elsevier Inc. All rights reserved.

Polymeric membrane materials for artificial organs.

PubMed

Kawakami, Hiroyoshi

2008-01-01

Many polymeric materials have already been used in the field of artificial organs. However, the materials used in artificial organs are not necessarily created with the best material selectivity and materials design; therefore, the development of synthesized polymeric membrane materials for artificial organs based on well-defined designs is required. The approaches to the development of biocompatible polymeric materials fall into three categories: (1) control of physicochemical characteristics on material surfaces, (2) modification of material surfaces using biomolecules, and (3) construction of biomimetic membrane surfaces. This review will describe current issues regarding polymeric membrane materials for use in artificial organs.

Neoplastic stomach lesions and their mimickers: spectrum of imaging manifestations

PubMed Central

Virmani, Vivek; Sethi, Vineeta; Fraser-Hill, Margret; Fasih, Najla; Kielar, Ania

2012-01-01

Abstract This review illustrates a wide spectrum of gastric neoplasms with emphasis on imaging findings helpful in characterizing various gastric neoplasms. Both the malignant and benign neoplasms along with focal gastric masses mimicking tumour are illustrated. Moreover, imaging clues to reach an accurate diagnosis are emphasized. PMID:22935192

Selective attention and control of action: comparative psychology of an artificial, evolved agent and people.

PubMed

Ward, Robert; Ward, Ronnie

2008-10-01

This study examined the selective attention abilities of a simple, artificial, evolved agent and considered implications of the agent's performance for theories of selective attention and action. The agent processed two targets in continuous time, catching one and then the other. This task required many cognitive operations, including prioritizing the first target (T1) over the second (T2); selectively focusing responses on T1, while preventing T2 from interfering with responses; creating a memory for the unselected T2 item, so that it could be efficiently processed later; and reallocating processing towards T2 after catching T1. The evolved agent demonstrated all these abilities. Analysis shows that the agent used reactive inhibition to selectively focus behavior. That is, the more salient T2, the more strongly responses towards T2 were inhibited and the slower the agent was to subsequently reallocate processing towards T2. Reactive inhibition was also suggested in two experiments with people, performing a virtually identical catch task. The presence of reactive inhibition in the simple agent and in people suggests that it is an important mechanism for selective processing.

Noncaloric Sweeteners Induce Peripheral Serotonin Secretion via the T1R3-Dependent Pathway in Human Gastric Parietal Tumor Cells (HGT-1).

PubMed

Zopun, Muhammet; Lieder, Barbara; Holik, Ann-Katrin; Ley, Jakop P; Hans, Joachim; Somoza, Veronika

2018-06-25

The role of sweet taste in energy intake and satiety regulation is still controversial. Noncaloric artificial sweeteners (NCSs) are thought to help reduce energy intake, although little is known about their impact on the satiating neurotransmitter serotonin (5-HT). In the gastrointestinal (GI) tract, 5-HT regulates gastric acid secretion and gastric motility, both part of the complex network of mechanisms regulating food intake and satiety. This study demonstrated a stimulating impact compared to controls (100%) on 5-HT release in human gastric tumor cells (HGT-1) by the NCSs cyclamate (50 mM, 157% ± 6.3%), acesulfame potassium (Ace K, 50 mM, 197% ± 8.6%), saccharin (50 mM, 147% ± 6.7%), sucralose (50 mM, 194% ± 11%), and neohesperidin dihydrochalcone (NHDC, 1 mM, 201% ± 13%). Although these effects were not associated with the sweet taste intensity of the NCSs tested, involvement of the sweet receptor subunit T1R3 in the NCS-evoked response was demonstrated by mRNA expression of TAS1R3, co-incubation experiments using the T1R3 receptor antagonist lactisole, and a TAS1R3 siRNA knockdown approach. Analysis of the downstream signaling revealed activation of the cAMP/ERK/Ca 2+ cascade. Co-treatment experiments with 10 mM glucose enhanced the 5-HT release induced by cyclamate, Ace K, saccharin, and sucralose, thereby supporting the enhancing effect of glucose on a NCS-mediated response. Overall, the results obtained identify NCSs as potent inducers of 5-HT release via T1R3 in human gastric parietal cells in culture and warrant in vivo studies to demonstrate their efficacy.

Lower numbers of circulating natural killer T (NK T) cells in individuals with human T lymphotropic virus type 1 (HTLV-1) associated neurological disease

PubMed Central

Ndhlovu, L C; Snyder-Cappione, J E; Carvalho, K I; Leal, F E; Loo, C P; bruno, F R; Jha, A R; Devita, D; Hasenkrug, A M; Barbosa, H M R; Segurado, A C; Nixon, D F; Murphy, E L; Kallas, E G

2009-01-01

Human T lymphotropic virus type 1 (HTLV-1) infects 10–20 million people worldwide. The majority of infected individuals are asymptomatic; however, approximately 3% develop the debilitating neurological disease HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). There is also currently no cure, vaccine or effective therapy for HTLV-1 infection, and the mechanisms for progression to HAM/TSP remain unclear. NK T cells are an immunoregulatory T cell subset whose frequencies and effector functions are associated critically with immunity against infectious diseases. We hypothesized that NK T cells are associated with HAM/TSP progression. We measured NK T cell frequencies and absolute numbers in individuals with HAM/TSP infection from two cohorts on two continents: São Paulo, Brazil and San Francisco, CA, USA, and found significantly lower levels when compared with healthy subjects and/or asymptomatic carriers. Also, the circulating NK T cell compartment in HAM/TSP subjects is comprised of significantly more CD4+ and fewer CD8+ cells than healthy controls. These findings suggest that lower numbers of circulating NK T cells and enrichment of the CD4+ NK T subset are associated with HTLV-1 disease progression. PMID:19778295

Manufacture of Clinical-Grade CD19-Specific T Cells Stably Expressing Chimeric Antigen Receptor Using Sleeping Beauty System and Artificial Antigen Presenting Cells

PubMed Central

Singh, Harjeet; Figliola, Matthew J.; Dawson, Margaret J.; Olivares, Simon; Zhang, Ling; Yang, Ge; Maiti, Sourindra; Manuri, Pallavi; Senyukov, Vladimir; Jena, Bipulendu; Kebriaei, Partow; Champlin, Richard E.; Huls, Helen; Cooper, Laurence J. N.

2013-01-01

Adoptive transfer of T cells expressing a CD19-specific chimeric antigen receptor (CAR) is being evaluated in multiple clinical trials. Our current approach to adoptive immunotherapy is based on a second generation CAR (designated CD19RCD28) that signals through a CD28 and CD3-ζ endodomain. T cells are electroporated with DNA plasmids from the Sleeping Beauty (SB) transposon/transposase system to express this CAR. Stable integrants of genetically modified T cells can then be retrieved when co-cultured with designer artificial antigen presenting cells (aAPC) in the presence of interleukin (IL)-2 and 21. Here, we reveal how the platform technologies of SB-mediated transposition and CAR-dependent propagation on aAPC were adapted for human application. Indeed, we have initiated clinical trials in patients with high-risk B-lineage malignancies undergoing autologous and allogeneic hematopoietic stem-cell transplantation (HSCT). We describe the process to manufacture clinical grade CD19-specific T cells derived from healthy donors. Three validation runs were completed in compliance with current good manufacturing practice for Phase I/II trials demonstrating that by 28 days of co-culture on γ-irradiated aAPC ∼1010 T cells were produced of which >95% expressed CAR. These genetically modified and propagated T cells met all quality control testing and release criteria in support of infusion. PMID:23741305

Cardiac T1 Imaging

PubMed Central

Jerosch-Herold, Michael; Kwong, Raymond Y.

2014-01-01

T1 mapping of the heart has evolved into a valuable tool to evaluate myocardial tissue properties, with or without contrast injection, including assessment of myocardial edema and free water content, extra-cellular volume (expansion), and most recently cardiomyocyte hypertrophy. The MRI pulse sequence techniques developed for these applications have had to address at least two important considerations for cardiac applications: measure magnetization inversion recoveries during cardiac motion with sufficient temporal resolution for the shortest expected T1 values, and, secondly, obtain these measurements within a time during which a patient can comfortably suspend breathing. So-called Look-Locker techniques, and variants thereof, which all sample multiple points of a magnetization recovery after each magnetization preparation have therefore become a mainstay in this field. The rapid pace of advances and new findings based on cardiac T1 mapping for assessment of diffuse fibrosis, or myocardial edema show that these techniques enrich the capabilities of MRI for myocardial tissue profiling, which is arguably unmatched by other cardiac imaging modalities. PMID:24509619

An overview of artificial intelligence and robotics. Volume 1: Artificial intelligence. Part A: The core ingredients

NASA Technical Reports Server (NTRS)

Gevarter, W. B.

1983-01-01

Artificial Intelligence (AI) is an emerging technology that has recently attracted considerable attention. Many applications are now under development. The goal of Artificial Intelligence is focused on developing computational approaches to intelligent behavior. This goal is so broad - covering virtually all aspects of human cognitive activity - that substantial confusion has arisen as to the actual nature of AI, its current status and its future capability. This volume, the first in a series of NBS/NASA reports on the subject, attempts to address these concerns. Thus, this report endeavors to clarify what AI is, the foundations on which it rests, the techniques utilized, applications, the participants and, finally, AI's state-of-the-art and future trends. It is anticipated that this report will prove useful to government and private engineering and research managers, potential users, and others who will be affected by this field as it unfolds.

Post-pancreatitis Fat Necrosis Mimicking Carcinomatosis.

PubMed

Smith, Joshua P; Arnoletti, J Pablo; Varadarajulu, Shyam; Morgan, Desiree E

2008-01-01

Acute pancreatitis can result in retroperitoneal fat necrosis, typically occurring in the peripancreatic region, with extension into the transverse mesocolon, omentum and mesenteric root. When evaluated with contrast enhanced computed tomography (CECT), acute peripancreatic post necrotic collections typically become lower in attenuation over time, and often appear as homogeneous fluid collections. Saponification as a complication of fat necrosis in patients with acute pancreatitis is a well recognized clinical entity. While retroperitonal fat necrosis is commonly seen on CECT, saponification is not a prominent imaging feature. We present a case of acute pancreatitis complicated by extensive saponification of fat throughout the retroperitoneum and peritoneal lining, mimicking carcinomatosis.

Cogan's syndrome mimicking acute Lyme arthritis.

PubMed

Schwegmann, J P; Enzenauer, R J

1995-05-01

A pediatric case of Cogan's syndrome mimicking acute Lyme arthritis is described. A 12-year-old black boy was admitted to the pediatric service for presumed right knee septic arthritis. Symptoms included acute pain and swelling with decreased range-of-motion. Although the patient's right knee symptoms and positive Lyme serology were consistent with a diagnosis of Lyme arthritis, the presence of sensorineural hearing loss and interstitial keratitis with inflammatory arthritis suggested a diagnosis of Cogan's syndrome. Subsequent Western blot analysis was negative for Borrelia burgdorferi antigens. The patient had dramatic clinical improvement of musculoskeletal and ophthalmologic complaints shortly after receiving high-dose corticosteroids, although residual sensorineural hearing loss persisted.

Tonic ubiquitylation controls T-cell receptor:CD3 complex expression during T-cell development.

PubMed

Wang, Haopeng; Holst, Jeff; Woo, Seng-Ryong; Guy, Cliff; Bettini, Matt; Wang, Yao; Shafer, Aaron; Naramura, Mayumi; Mingueneau, Michaël; Dragone, Leonard L; Hayes, Sandra M; Malissen, Bernard; Band, Hamid; Vignali, Dario A A

2010-04-07

Expression of the T-cell receptor (TCR):CD3 complex is tightly regulated during T-cell development. The mechanism and physiological role of this regulation are unclear. Here, we show that the TCR:CD3 complex is constitutively ubiquitylated in immature double positive (DP) thymocytes, but not mature single positive (SP) thymocytes or splenic T cells. This steady state, tonic CD3 monoubiquitylation is mediated by the CD3varepsilon proline-rich sequence, Lck, c-Cbl, and SLAP, which collectively trigger the dynamin-dependent downmodulation, lysosomal sequestration and degradation of surface TCR:CD3 complexes. Blocking this tonic ubiquitylation by mutating all the lysines in the CD3 cytoplasmic tails significantly upregulates TCR levels on DP thymocytes. Mimicking monoubiquitylation by expression of a CD3zeta-monoubiquitin (monoUb) fusion molecule significantly reduces TCR levels on immature thymocytes. Moreover, modulating CD3 ubiquitylation alters immunological synapse (IS) formation and Erk phosphorylation, thereby shifting the signalling threshold for positive and negative selection, and regulatory T-cell development. Thus, tonic TCR:CD3 ubiquitylation results in precise regulation of TCR expression on immature T cells, which is required to maintain the fidelity of T-cell development.

Tonic ubiquitylation controls T-cell receptor:CD3 complex expression during T-cell development

PubMed Central

Wang, Haopeng; Holst, Jeff; Woo, Seng-Ryong; Guy, Cliff; Bettini, Matt; Wang, Yao; Shafer, Aaron; Naramura, Mayumi; Mingueneau, Michaël; Dragone, Leonard L; Hayes, Sandra M; Malissen, Bernard; Band, Hamid; Vignali, Dario A A

2010-01-01

Expression of the T-cell receptor (TCR):CD3 complex is tightly regulated during T-cell development. The mechanism and physiological role of this regulation are unclear. Here, we show that the TCR:CD3 complex is constitutively ubiquitylated in immature double positive (DP) thymocytes, but not mature single positive (SP) thymocytes or splenic T cells. This steady state, tonic CD3 monoubiquitylation is mediated by the CD3ɛ proline-rich sequence, Lck, c-Cbl, and SLAP, which collectively trigger the dynamin-dependent downmodulation, lysosomal sequestration and degradation of surface TCR:CD3 complexes. Blocking this tonic ubiquitylation by mutating all the lysines in the CD3 cytoplasmic tails significantly upregulates TCR levels on DP thymocytes. Mimicking monoubiquitylation by expression of a CD3ζ-monoubiquitin (monoUb) fusion molecule significantly reduces TCR levels on immature thymocytes. Moreover, modulating CD3 ubiquitylation alters immunological synapse (IS) formation and Erk phosphorylation, thereby shifting the signalling threshold for positive and negative selection, and regulatory T-cell development. Thus, tonic TCR:CD3 ubiquitylation results in precise regulation of TCR expression on immature T cells, which is required to maintain the fidelity of T-cell development. PMID:20150895

Comparing two quantitative methods for studying remineralization of artificial caries.

PubMed

Lo, E C M; Zhi, Q H; Itthagarun, A

2010-04-01

To compare the detection of changes before and after remineralization of artificial enamel and dentin caries by microCT scanning, polarized light microscopy (PLM) and transverse microradiography (TMR). Fourteen extracted premolars were cut into tooth blocks and painted with an acid-resistant varnish leaving one enamel and one dentin surface exposed. The tooth blocks were immersed into demineralizing solution for 4 days to produce artificial caries-like lesions and scanned by microCT. Then the 14 tooth blocks were randomly allocated into two groups. Seven tooth blocks in Group I were cut longitudinally through the exposed surface into 100-150 microm thick sections and microradiographs were taken. The other seven tooth blocks in Group II were left intact. All the tooth blocks and sections were then immersed into remineralizing solution for 5 days. PLM and TMR of the tooth sections in Group I were taken again. Depth of the lesion on the TMR was measured. Tooth blocks in Group II were scanned by microCT. Mean lesion depth in Group I reduced by 13.0% and 8.2% after remineralization for enamel and dentin, respectively (paired t-test, P<0.001). In Group II, linear attenuation coefficient (LAC) of the region of interest (ROI) increased by 11.1% and 23.8% after remineralization for enamel and dentin lesions, respectively (paired t-test, P<0.001). Both microCT and microradiography are able to detect a change of similar magnitude in the artificial caries lesions after remineralization. MicroCT may be used to substitute TMR and PLM in in vitro studies about caries. Copyright 2010 Elsevier Ltd. All rights reserved.

Forming characteristics of artificial aging Al-Mg-Si-Cu sheet alloys

NASA Astrophysics Data System (ADS)

Klos, Artur; Kellner, Sven; Wortberg, Daniel; Walter, Philipp; Bassi, Corrado; Merklein, Marion

2017-10-01

AA6111 is a commonly used aluminum alloy for body-in-white (BIW) components with good bake-hardening response, high strength and excellent formability. For industrial applications various process strategies are considered to reach strength of about 250 MPa in the final body part with that type of alloy. The purpose of this paper is to discuss recent process strategies of high-strength AA6111 sheets to evaluate the forming characteristics, precipitation kinetics dissolution and mechanical properties in the final condition. The forming behavior is investigated by four potential process chains after single-stage or multi-stage heat treatment including T4 (pre-aged at > 80 °C after quenching), T61 (T4 + artificial aged at 120-150 °C for 10-18 h), T6 (T4 + artificial aged at 180-220°C up to 12 h) and PFHT (T4 + post form heat treatment at 205°C for 30 min). The experimental input for characterization of the formability consists of tensile tests, bending tests and drawing tests. Differential Scanning Calorimetry (DSC) is used, to correlate the forming behavior with the precipitation distribution in the advanced stages of aging. The study shows that the forming behavior is strongly dependent on the condition the alloy.

An overview of artificial intelligence and robotics. Volume 1: Artificial intelligence. Part B: Applications

NASA Technical Reports Server (NTRS)

Gevarter, W. B.

1983-01-01

Artificial Intelligence (AI) is an emerging technology that has recently attracted considerable attention. Many applications are now under development. This report, Part B of a three part report on AI, presents overviews of the key application areas: Expert Systems, Computer Vision, Natural Language Processing, Speech Interfaces, and Problem Solving and Planning. The basic approaches to such systems, the state-of-the-art, existing systems and future trends and expectations are covered.

Yang-Baxter deformations of W2,4 × T1,1 and the associated T-dual models

NASA Astrophysics Data System (ADS)

Sakamoto, Jun-ichi; Yoshida, Kentaroh

2017-08-01

Recently, for principal chiral models and symmetric coset sigma models, Hoare and Tseytlin proposed an interesting conjecture that the Yang-Baxter deformations with the homogeneous classical Yang-Baxter equation are equivalent to non-abelian T-dualities with topological terms. It is significant to examine this conjecture for non-symmetric (i.e., non-integrable) cases. Such an example is the W2,4 ×T 1 , 1 background. In this note, we study Yang-Baxter deformations of type IIB string theory defined on W2,4 ×T 1 , 1 and the associated T-dual models, and show that this conjecture is valid even for this case. Our result indicates that the conjecture would be valid beyond integrability.

Artificial Vector Calibration Method for Differencing Magnetic Gradient Tensor Systems

PubMed Central

Li, Zhining; Zhang, Yingtang; Yin, Gang

2018-01-01

The measurement error of the differencing (i.e., using two homogenous field sensors at a known baseline distance) magnetic gradient tensor system includes the biases, scale factors, nonorthogonality of the single magnetic sensor, and the misalignment error between the sensor arrays, all of which can severely affect the measurement accuracy. In this paper, we propose a low-cost artificial vector calibration method for the tensor system. Firstly, the error parameter linear equations are constructed based on the single-sensor’s system error model to obtain the artificial ideal vector output of the platform, with the total magnetic intensity (TMI) scalar as a reference by two nonlinear conversions, without any mathematical simplification. Secondly, the Levenberg–Marquardt algorithm is used to compute the integrated model of the 12 error parameters by nonlinear least-squares fitting method with the artificial vector output as a reference, and a total of 48 parameters of the system is estimated simultaneously. The calibrated system outputs along the reference platform-orthogonal coordinate system. The analysis results show that the artificial vector calibrated output can track the orientation fluctuations of TMI accurately, effectively avoiding the “overcalibration” problem. The accuracy of the error parameters’ estimation in the simulation is close to 100%. The experimental root-mean-square error (RMSE) of the TMI and tensor components is less than 3 nT and 20 nT/m, respectively, and the estimation of the parameters is highly robust. PMID:29373544

Artificial organs: recent progress in artificial hearing and vision.

PubMed

Ifukube, Tohru

2009-01-01

Artificial sensory organs are a prosthetic means of sending visual or auditory information to the brain by electrical stimulation of the optic or auditory nerves to assist visually impaired or hearing-impaired people. However, clinical application of artificial sensory organs, except for cochlear implants, is still a trial-and-error process. This is because how and where the information transmitted to the brain is processed is still unknown, and also because changes in brain function (plasticity) remain unknown, even though brain plasticity plays an important role in meaningful interpretation of new sensory stimuli. This article discusses some basic unresolved issues and potential solutions in the development of artificial sensory organs such as cochlear implants, brainstem implants, artificial vision, and artificial retinas.

Being Mimicked Increases Prosocial Behavior in 18-Month-Old Infants

ERIC Educational Resources Information Center

Carpenter, Malinda; Uebel, Johanna; Tomasello, Michael

2013-01-01

Most previous research on imitation in infancy has focused on infants' learning of instrumental actions on objects. This study focused instead on the more social side of imitation, testing whether being mimicked increases prosocial behavior in infants, as it does in adults (van Baaren, Holland, Kawakami, & van Knippenberg, 2004).…

Artificial neural network model for photosynthetic pigments identification using multi wavelength chromatographic data

NASA Astrophysics Data System (ADS)

Prilianti, K. R.; Hariyanto, S.; Natali, F. D. D.; Indriatmoko, Adhiwibawa, M. A. S.; Limantara, L.; Brotosudarmo, T. H. P.

2016-04-01

The development of rapid and automatic pigment characterization method become an important issue due to the fact that there are only less than 1% of plant pigments in the earth have been explored. In this research, a mathematical model based on artificial intelligence approach was developed to simplify and accelerate pigment characterization process from HPLC (high-performance liquid chromatography) procedure. HPLC is a widely used technique to separate and identify pigments in a mixture. Input of the model is chromatographic data from HPLC device and output of the model is a list of pigments which is the spectrum pattern is discovered in it. This model provides two dimensional (retention time and wavelength) fingerprints for pigment characterization which is proven to be more accurate than one dimensional fingerprint (fixed wavelength). Moreover, by mimicking interconnection of the neuron in the nervous systems of the human brain, the model have learning ability that could be replacing expert judgement on evaluating spectrum pattern. In the preprocessing step, principal component analysis (PCA) was used to reduce the huge dimension of the chromatographic data. The aim of this step is to simplify the model and accelerate the identification process. Six photosynthetic pigments i.e. zeaxantin, pheophytin a, α-carotene, β-carotene, lycopene and lutein could be well identified by the model with accuracy up to 85.33% and processing time less than 1 second.

Honeycomb artificial spin ice at low temperatures

NASA Astrophysics Data System (ADS)

Zeissler, Katharina; Chadha, Megha; Cohen, Lesley; Branford, Will

2015-03-01

Artificial spin ice is a macroscopic playground for magnetically frustrated systems. It consists of a geometrically ordered but magnetically frustrated arrangement of ferromagnetic macros spins, e.g. an arrangement of single domain ferromagnetic nanowires on a honeycomb lattice. Permalloy and cobalt which have critical temperature scales far above 290 K, are commonly used in the construction of such systems. Previous measurements have shown unusual features in the magnetotransport signature of cobalt honeycomb artificial spin ice at temperatures below 50 K which are due to changes in the artificial spin ice's magnetic reversal. In that case, the artificial spin ice bars were 1 micron long, 100 nm wide and 20 nm thick. Here we explore the low temperature magnetic behavior of honeycomb artificial spin ice structures with a variety of bar dimensions, indirectly via electrical transport, as well as, directly using low temperature magnetic imaging techniques. We discuss the extent to which this change in the magnetic reversal at low temperatures is generic to the honeycomb artificial spin ice geometry and whether the bar dimensions have an influence on its onset temperature. The EPSRC (Grant No. EP/G004765/1; Grant No. EP/L504786/1) and the Leverhulme Trust (Grant No. RPG 2012-692) funded this scientific work.

Artificial Intelligence and Its Importance in Education.

ERIC Educational Resources Information Center

Tilmann, Martha J.

Artificial intelligence, or the study of ideas that enable computers to be intelligent, is discussed in terms of what it is, what it has done, what it can do, and how it may affect the teaching of tomorrow. An extensive overview of artificial intelligence examines its goals and applications and types of artificial intelligence including (1) expert…

Demons-meigs pseudosyndrome mimicking the symptoms of pregnancy: a case report.

PubMed

Nohuz, Erdogan; Alaboud, Maher; El-Drayi, Bilal; Tamburro, Stefano; Kachkach, Said; Varga, Janos

2014-10-01

The Demons-Meigs syndrome should usually be evoked in case of presence of a typical triad: abdominopelvic mass, ascites and hydrothorax. Its diagnosis appears crucial to prevent the realization of unnecessary surgical procedures. A 32-year-old woman presented in April 2012 to the emergency department of our maternity unit (General Hospital, Thiers, France) with an abdominal distension mimicking the symptoms of a pregnancy at term. Physical examination revealed a voluminous painful abdominopelvic mass, extended from the pelvis to the upper abdomen with a large right pleural effusion. Ultrasound and computed tomography showed it was a tumor measuring more than 300 mm in diameter with a right hydrothorax. Serum CA-125 level was 289 U/ml. Cytologic analysis of the pleural effusion didn't show any malignant cells. In this study, Demons-Meigs syndrome was recognized. A laparoscopico-laparotomic management permitted an aspiration of 23 liters of a brownish liquid and an unilateral adnexectomy after pleural paracentesis was performed. Frozen section demonstrated benign mucinous cystadenoma. The final histologic findings objectified intracystic intestinal type ovarian mucinous borderline tumor. After multidisciplinary consultation, the patient was re-operated one month later. The exploration didn't reveal any suspected lesions and appendectomy and omentectomy were performed. The postoperative course was uneventful. Serum CA-125 level was normal at the time of the reoperation and 24 months after the initial surgery. The preoperative recognition of a Demons-Meigs syndrome or a Demons' pseudosyndrome is essential to avoid useless surgical procedures.

Establishment of an Artificial Tick Feeding System to Study Theileria lestoquardi Infection

PubMed Central

Tajeri, Shahin; Razmi, Gholamreza; Haghparast, Alireza

2016-01-01

The establishment of good experimental models for Theileria sp. infection is important for theileriosis research. Routinely, infection of ticks is accomplished by feeding on parasite-infected animals (sheep, cows and horses), which raises practical and ethical problems, driving the search for alternative methods of tick infection. Artificial tick feeding systems are based mainly on rearing ticks on host-derived or hand-made artificial membranes. We developed a modified feeding assay for infecting nymphal stages of Hyalomma anatolicum ticks with Theileria lestoquardi, a highly pathogenic parasite of sheep. We compared two different membranes: an artificial silicone membrane and a natural alternative using mouse skin. We observed high attachment rates with mouse skin, whereas in vitro feeding of H. anatolicum nymphs on silicone membranes was unsuccessful. We could infect H. anatolicum nymphs with T. lestoquardi and the emerging adult ticks transmitted infective parasites to sheep. In contrast, similar infections with Rhipicephalus bursa, a representative tick with short mouth-parts that was proposed as a vector for T. lestoquardi, appeared not to be a competent vector tick species. This is the first report of an experimentally controlled infection of H. anatolicum with T. lestoquardi and opens avenues to explore tick-parasite dynamics in detail. PMID:28036364

Mechanical Implantation of Urothelium Into Periureteral Soft Tissue: A Series of 4 Cases Mimicking High-stage Urothelial Carcinoma.

PubMed

Wobker, Sara E; Aron, Manju; Epstein, Jonathan I

2016-11-01

In the upper genitourinary tract of the ureter and renal pelvis, any invasion of urothelial carcinoma (UC) beyond the thin muscularis is considered pT3 disease, which may prompt adjuvant chemotherapy. Ureteroscopy is commonly used in the workup of these lesions to obtain tissue biopsies and cytology specimens, or to place stents for the relief of obstructive symptoms. The current study describes 4 cases in which the presence of small nests of urothelium in periureteral and peripelvic soft tissue was noted after ureteroscopic instrumentation, mimicking high-stage UC. All 4 cases had a history of ureteral instrumentation with biopsy of the suspected UC. The diagnostic biopsies showed low-grade noninvasive papillary UC (n=2), papillary urothelial neoplasm of uncertain malignant potential (n=1), and benign inverted urothelial papilloma (n=1). In the definitive resection specimens, small nests of bland urothelium were present in the periureteral or peripelvic soft tissue, raising the possibility of pT3 UC. We interpreted these displaced small nests to be the result of mechanical implantation occurring during the ureteroscopic procedure on the basis of the finding of associated linear fibrosis, inflammation, hemorrhage, and foreign body giant cells. In the setting of low-grade or benign urothelial neoplasms in the upper urinary tract, caution is warranted when cytologically bland nests of the urothelium are identified beyond the muscularis that could represent mechanically induced implants as opposed to invasive UC extending into peripelvic or periureteral soft tissue.

COMPARISON OF ARTIFICIAL NEOCHORDAE AND NATIVE CHORDAL TRANSFER IN THE REPAIR OF A FLAIL POSTERIOR MITRAL LEAFLET: AN EXPERIMENTAL STUDY

PubMed Central

Padala, Muralidhar; Cardinau, Benedicte; Gyoneva, Lazarina I.; Thourani, Vinod H.

2013-01-01

BACKGROUND Surgical reconstruction of a flail posterior leaflet is a routine mitral valve repair, the techniques for which have evolved from leaflet resection to leaflet preservation. Artificial ePTFE neochordae are frequently used to stabilize the flail leaflet, and seldom translocation of the native secondary chordae of the valve to the leaflet free edge is used. In this study, we sought to investigate the efficacy of the two techniques to correct posterior leaflet prolapse and reduce mitral regurgitation, and quantify the acute post-repair leaflet kinematics. METHODS Adult porcine mitral valves (N =7) were studied in a pulsatile left heart experimental model in which isolated P2 flail was mimicked by marginal chordal transection. Baseline conditions were established in each valve under normal conditions (control), and followed by induction of isolated P2 flail by transecting the two marginal chordae on the posterior leaflet free edge (disease). The flail posterior leaflet was reconstructed using artificial neochordae (repair 1) and then native chordal translocation (repair 2). Reduction in leaflet flail, changes in mitral regurgitation fraction, leaflet coaptation length, and posterior leaflet mobility were measured using B-mode echocardiography or color doppler. RESULTS At baseline, all the valves were competent with no mitral regurgitation. After transection of the marginal chordae on the posterior leaflet, isolated P2 flail was evident with 13.7±13% regurgitation. Reconstruction with artificial neochordae eliminated leaflet flail and reduced mitral regurgitation to 3.2± 2.8%, and with chordal translocation leaflet flail was corrected and mitral regurgitation was measured at 2.3±2.6%. Using either repair techniques, leaflet coaptation and mobility of the repaired leaflets were adequate and comparable to the baseline measurements. CONCLUSIONS Comparable reduction leaflet flail and regurgitation, and restoration of physiological leaflet coaptation with the

The cutaneous manifestations and common mimickers of physical child abuse.

PubMed

Mudd, Shawna S; Findlay, Jeanne S

2004-01-01

The cutaneous manifestations of physical child abuse are some of the most common and easily recognized forms of injury. To make an accurate assessment and diagnosis, it is important to differentiate between inflicted cutaneous injuries and mimickers of physical abuse. Likewise, an understanding of reporting guidelines helps guide practitioners in their decision making.

The Face of the Chameleon: The Experience of Facial Mimicry for the Mimicker and the Mimickee

PubMed Central

Kulesza, Wojciech Marek; Cisłak, Aleksandra; Vallacher, Robin R.; Nowak, Andrzej; Czekiel, Martyna; Bedynska, Sylwia

2015-01-01

ABSTRACT This research addressed three questions concerning facial mimicry: (a) Does the relationship between mimicry and liking characterize all facial expressions, or is it limited to specific expressions? (b) Is the relationship between facial mimicry and liking symmetrical for the mimicker and the mimickee? (c) Does conscious mimicry have consequences for emotion recognition? A paradigm is introduced in which participants interact over a computer setup with a confederate whose prerecorded facial displays of emotion are synchronized with participants’ behavior to create the illusion of social interaction. In Experiment 1, the confederate did or did not mimic participants’ facial displays of various subsets of basic emotions. Mimicry promoted greater liking for the confederate regardless of which emotions were mimicked. Experiment 2 reversed these roles: participants were instructed to mimic or not to mimic the confederate’s facial displays. Mimicry did not affect liking for the confederate but it did impair emotion recognition. PMID:25811746

AM: An Artificial Intelligence Approach to Discovery in Mathematics as Heuristic Search

DTIC Science & Technology

1976-07-01

Artificial Intelligence Approach to Discovery in Mathematics as Heuristic Search by Douglas B. Len-t APPROVED FOR PUBLIC RELEASE; DISTRIBUTION IS UNLIMITED (A...570 AM: An Artificial Intelligence Approach to Discovery in Mathematics as Heuristic Search by Douglas B. Lenat ABSTRACT A program, called "AM", is...While AM’s " approach " to empirical research may be used in other scientific domains, the main limitation (reliance on hindsight) will probably recur

Influence of MC3T3-E1 preosteoblast culture on the corrosion of a T6-treated AZ91 alloy.

PubMed

Brooks, Emily K; Tobias, Menachem E; Yang, Shuying; Bone, Lawrence B; Ehrensberger, Mark T

2016-02-01

This study investigated the corrosion of artificially aged T6 heat-treated Mg-9%Al-1%Zn (AZ91) for biomedical applications. Corrosion tests and surface analysis were completed both with and without a monolayer of mouse preosteoblast MC3T3-E1 cells cultured on the sample. Electrochemical impedance spectroscopy (EIS) and inductively coupled plasma mass spectroscopy (ICPMS) were used to explore the corrosion processes after either 3 or 21 days of AZ91 incubation in cell culture medium (CCM). The EIS showed both the inner layer resistance (Rin ) and outer layer resistance (Rout ) were lower for samples without cells cultured on the surface at 3 days (Rin  = 2.64 e4 Ω/cm(2) , Rout  = 140 Ω/cm(2) ) compared to 21 days (Rin  = 3.60 e4 Ω/cm(2) , Rout  = 287 Ω/cm(2) ) due to precipitation of magnesium and calcium phosphates over time. Samples with preosteoblasts cultured on the surface had a slower initial corrosion (3 day, Rin  = 1.88 e5 Ω/cm(2) , Rout  = 1060 Ω/cm(2) ) which was observed to increase over time (21 day, Rin  = 2.99 e4 Ω/cm(2) , Rout  = 287 Ω/cm(2) ). Changes in the corrosion processes were thought to be related to changes in the coverage provided by the cell layer. Our results reveal that the presence of cells and biological processes are able to significantly influence the corrosion rate of AZ91. © 2015 Wiley Periodicals, Inc.

Lyme disease presenting with facial palsy and myocarditis mimicking myocardial infarction.

PubMed

Gilson, Julieta; Khalighi, Koroush; Elmi, Farhad; Krishnamurthy, Mahesh; Talebian, Amirsina; Toor, Rubinder S

2017-01-01

A 45-year-old woman presented with a sudden episode of typical chest pain, radiating to her neck. The patient denied premature coronary artery disease in the family. Initial EKG showed normal sinus rhythm with a 1 mm ST-elevation involving lead II and lead aVF and a 1 mm ST-depression in lead V1 with associated T-wave inversion. Initial Troponin I (normal <0.4 ng/mL) and CK-MB (normal <7.7 ng/mL) were elevated at 7.82 ng/mL and 55.2 ng/mL, respectively. Six hours later, Troponin I increased to 13.44 ng/mL and CK-MB to 75.7 ng/mL. The patient underwent cardiac catheterization which did not show any significant obstructive coronary artery disease. Two days later the patient developed right-sided facial palsy. Diagnosis of Lyme disease was confirmed by ELISA with positive IgM and IgG antibodies. Treatment with intravenous ceftriaxone and oral steroids was started. Eventually resolution of symptoms and, normalization of cardiac markers and EKG changes, were achieved. This is a rare case of Lyme myocarditis associated with markedly elevated Troponin I, normal left ventricle function, and an absence of conduction abnormalities. To the best of our knowledge, Lyme myocarditis mimicking acute coronary syndrome with such high levels of Troponin I and neurologic compromise has not been previously described. Lyme myocarditis may be a challenging diagnosis in endemic areas especially in patients with coronary artery disease risk factors, presenting with typical chest pain, EKG changes and positive cardiac biomarkers. Therefore, it should be considered a differential diagnosis in patients presenting with clinical symptoms suggestive of acute coronary syndrome. Abbreviations AV: Atrioventricular; CK-MB: Creatinine Kinase-MB; EKG: Electrocardiogram; ELISA: Enzyme-Linked Immunosorbent Assay; IgG: Immunoglobulin G; IgM: Immunoglobulin M.

"Machine" consciousness and "artificial" thought: an operational architectonics model guided approach.

PubMed

Fingelkurts, Andrew A; Fingelkurts, Alexander A; Neves, Carlos F H

2012-01-05

Instead of using low-level neurophysiology mimicking and exploratory programming methods commonly used in the machine consciousness field, the hierarchical operational architectonics (OA) framework of brain and mind functioning proposes an alternative conceptual-theoretical framework as a new direction in the area of model-driven machine (robot) consciousness engineering. The unified brain-mind theoretical OA model explicitly captures (though in an informal way) the basic essence of brain functional architecture, which indeed constitutes a theory of consciousness. The OA describes the neurophysiological basis of the phenomenal level of brain organization. In this context the problem of producing man-made "machine" consciousness and "artificial" thought is a matter of duplicating all levels of the operational architectonics hierarchy (with its inherent rules and mechanisms) found in the brain electromagnetic field. We hope that the conceptual-theoretical framework described in this paper will stimulate the interest of mathematicians and/or computer scientists to abstract and formalize principles of hierarchy of brain operations which are the building blocks for phenomenal consciousness and thought. Copyright © 2010 Elsevier B.V. All rights reserved.

Perceptual learning in a non-human primate model of artificial vision

PubMed Central

Killian, Nathaniel J.; Vurro, Milena; Keith, Sarah B.; Kyada, Margee J.; Pezaris, John S.

2016-01-01

Visual perceptual grouping, the process of forming global percepts from discrete elements, is experience-dependent. Here we show that the learning time course in an animal model of artificial vision is predicted primarily from the density of visual elements. Three naïve adult non-human primates were tasked with recognizing the letters of the Roman alphabet presented at variable size and visualized through patterns of discrete visual elements, specifically, simulated phosphenes mimicking a thalamic visual prosthesis. The animals viewed a spatially static letter using a gaze-contingent pattern and then chose, by gaze fixation, between a matching letter and a non-matching distractor. Months of learning were required for the animals to recognize letters using simulated phosphene vision. Learning rates increased in proportion to the mean density of the phosphenes in each pattern. Furthermore, skill acquisition transferred from trained to untrained patterns, not depending on the precise retinal layout of the simulated phosphenes. Taken together, the findings suggest that learning of perceptual grouping in a gaze-contingent visual prosthesis can be described simply by the density of visual activation. PMID:27874058

Autoimmune pancreatitis associated with renal lesions mimicking metastatic tumours

PubMed Central

Rudmik, Lucas; Trpkov, Kiril; Nash, Carla; Kinnear, Susan; Falck, Vincent; Dushinski, John; Dixon, Elijah

2006-01-01

Autoimmune pancreatitis is a chronic inflammatory disorder that is often misdiagnosed as pancreatic cancer. Since autoimmune pancreatitis is benign and responds to steroid management, it is important to diagnose it to avoid unnecessary surgical intervention. We describe a novel case of IgG4-associated autoimmune pancreatitis presenting with tubulointerstitial nephritis as renal lesions mimicking metastatic tumours but with no change in renal function. PMID:16908897

AT base pair anions versus (9-methyl-A)(1-methyl-T) base pair anions.

PubMed

Radisic, Dunja; Bowen, Kit H; Dabkowska, Iwona; Storoniak, Piotr; Rak, Janusz; Gutowski, Maciej

2005-05-04

The anionic base pairs of adenine and thymine, (AT)(-), and 9-methyladenine and 1-methylthymine, (MAMT)(-), have been investigated both theoretically and experimentally in a complementary, synergistic study. Calculations on (AT)(-) found that it had undergone a barrier-free proton transfer (BFPT) similar to that seen in other dimer anion systems and that its structural configuration was neither Watson-Crick (WC) nor Hoogsteen (HS). The vertical detachment energy (VDE) of (AT)(-) was determined by anion photoelectron spectroscopy and found to be in agreement with the VDE value predicted by theory for the BFPT mechanism. An AT pair in DNA is structurally immobilized into the WC configuration, in part, by being bonded to the sugars of the double helix. This circumstance was mimicked by methylating the sites on both A and T where these sugars would have been tied, viz., 9-methyladenine and 1-methylthymine. Calculations found no BFPT in (MAMT)(-) and a resulting (MAMT)(-) configuration that was either HS or WC, with the configurations differing in stability by ca. 2 kcal/mol. The photoelectron spectrum of (MAMT)(-) occurred at a completely different electron binding energy than had (AT)(-). Moreover, the VDE value of (MAMT)(-) was in agreement with that predicted by theory. The configuration of (MAMT)(-) and its lack of electron-induced proton transfer are inter-related. While there may be other pathways for electron-induced DNA alterations, BFPT in the WC/HS configurations of (AT)(-) is not feasible.

Viral tRNA Mimicry from a Biocommunicative Perspective

PubMed Central

Ariza-Mateos, Ascensión; Gómez, Jordi

2017-01-01

RNA viruses have very small genomes which limits the functions they can encode. One of the strategies employed by these viruses is to mimic key factors of the host cell so they can take advantage of the interactions and activities these factors typically participate in. The viral RNA genome itself was first observed to mimic cellular tRNA over 40 years ago. Since then researchers have confirmed that distinct families of RNA viruses are accessible to a battery of cellular factors involved in tRNA-related activities. Recently, potential tRNA-like structures have been detected within the sequences of a 100 mRNAs taken from human cells, one of these being the host defense interferon-alpha mRNA; these are then additional to the examples found in bacterial and yeast mRNAs. The mimetic relationship between tRNA, cellular mRNA, and viral RNA is the central focus of two considerations described below. These are subsequently used as a preface for a final hypothesis drawing on concepts relating to mimicry from the social sciences and humanities, such as power relations and creativity. Firstly, the presence of tRNA-like structures in mRNAs indicates that the viral tRNA-like signal could be mimicking tRNA-like elements that are contextualized by the specific carrier mRNAs, rather than, or in addition to, the tRNA itself, which would significantly increase the number of potential semiotic relations mediated by the viral signals. Secondly, and in particular, mimicking a host defense mRNA could be considered a potential new viral strategy for survival. Finally, we propose that mRNA’s mimicry of tRNA could be indicative of an ancestral intracellular conflict in which species of mRNAs invaded the cell, but from within. As the meaning of the mimetic signal depends on the context, in this case, the conflict that arises when the viral signal enters the cell can change the meaning of the mRNAs’ internal tRNA-like signals, from their current significance to that they had in the

Clinical heterogeneity of type 1 diabetes (T1D) found in Asia.

PubMed

Park, Yongsoo; Wintergerst, Kupper A; Zhou, Zhiguang

2017-10-01

Diabetes mellitus among young patients in Asia is caused by a complex set of factors. Although type 1 diabetes (T1D) remains the most common form of diabetes in children, the recent unabated increase in obesity has resulted in the emergence of type 2 diabetes (T2D) as a new type of diabetes among adolescents and young adults. In addition to the typical autoimmune type 1 diabetes (T1aD) and T2D patients, there is a variable incidence of cases of non-autoimmune types of T1D associated with insulin deficiency (T1bD). Additional forms have been described, including fulminant T1D (FT1D). Although most diagnoses of T1D are classified as T1aD, fulminant T1D exists as a hyper-acute subtype of T1D that affects older children, without associated autoimmunity. Patient with this rare aetiology of diabetes showed a complete loss of β-cell secretory capacity without evidence of recovery, necessitating long-term treatment with insulin. In addition, latent autoimmune diabetes in adults is a form of autoimmune-mediated diabetes, usually diagnosed during the insulin-dependent stage that follows a non-insulin requiring phase, which can be diagnosed earlier based on anti-islet autoantibody positivity. Some reports discuss T1bD. Others are elaborating on the presence of "atypical T1b diabetes," such as Flatbush diabetes. The prevalence of diabetes mellitus in young adults continues to rise in Asian populations as T2D increases. With improved characterization of patients with diabetes, the range of diabetic subgroups will become even more diverse in the future. Distinguishing T1D, T2D, and other forms of diabetes in young patients is challenging in Asian populations, as the correct diagnosis is clinically important and has implications for prognosis and management. Despite aetiological heterogeneity in the usual clinical setting, early diagnosis and classification of patients with diabetes relying on clinical grounds as well as measuring islet autoantibodies and fasting plasma C

Identification of novel gammadelta T-cell subsets following bacterial infection in the absence of Vgamma1+ T cells: homeostatic control of gammadelta T-cell responses to pathogen infection by Vgamma1+ T cells.

PubMed

Newton, Darren J; Andrew, Elizabeth M; Dalton, Jane E; Mears, Rainy; Carding, Simon R

2006-02-01

Although gammadelta T cells are a common feature of many pathogen-induced immune responses, the factors that influence, promote, or regulate the response of individual gammadelta T-cell subsets to infection is unknown. Here we show that in the absence of Vgamma1+ T cells, novel subsets of gammadelta T cells, expressing T-cell receptor (TCR)-Vgamma chains that normally define TCRgammadelta+ dendritic epidermal T cells (DETCs) (Vgamma5+), intestinal intraepithelial lymphocytes (iIELs) (Vgamma7+), and lymphocytes associated with the vaginal epithelia (Vgamma6+), are recruited to the spleen in response to bacterial infection in TCR-Vgamma1-/- mice. By comparison of phenotype and structure of TCR-Vgamma chains and/or -Vdelta chains expressed by these novel subsets with those of their epithelium-associated counterparts, the Vgamma6+ T cells elicited in infected Vgamma1-/- mice were shown to be identical to those found in the reproductive tract, from where they are presumably recruited in the absence of Vgamma1+ T cells. By contrast, Vgamma5+ and Vgamma7+ T cells found in infected Vgamma1-/- mice were distinct from Vgamma5+ DETCs and Vgamma7+ iIELs. Functional analyses of the novel gammadelta T-cell subsets identified for infected Vgamma1-/- mice showed that whereas the Vgamma5+ and Vgamma7+ subsets may compensate for the absence of Vgamma1+ T cells by producing similar cytokines, they do not possess cytocidal activity and they cannot replace the macrophage homeostasis function of Vgamma1+ T cells. Collectively, these findings identify novel subsets of gammadelta T cells, the recruitment and activity of which is under the control of Vgamma1+ T cells.

Ectopic expression of anti-HIV-1 shRNAs protects CD8{sup +} T cells modified with CD4ζ CAR from HIV-1 infection and alleviates impairment of cell proliferation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kamata, Masakazu, E-mail: masa3k@ucla.edu; Kim, Patrick Y.; Ng, Hwee L.

Chimeric antigen receptors (CARs) are artificially engineered receptors that confer a desired specificity to immune effector T cells. As an HIV-1-specific CAR, CD4ζ CAR has been extensively tested in vitro as well as in clinical trials. T cells modified with this CAR mediated highly potent anti-HIV-1 activities in vitro and were well-tolerated in vivo, but exerted limited effects on viral load and reservoir size due to poor survival and/or functionality of the transduced cells in patients. We hypothesize that ectopic expression of CD4ζ on CD8{sup +} T cells renders them susceptible to HIV-1 infection, resulting in poor survival of those cells. To testmore » this possibility, highly purified CD8{sup +} T cells were genetically modified with a CD4ζ-encoding lentiviral vector and infected with HIV-1. CD8{sup +} T cells were vulnerable to HIV-1 infection upon expression of CD4ζ as evidenced by elevated levels of p24{sup Gag} in cells and culture supernatants. Concurrently, the number of CD4ζ-modified CD8{sup +} T cells was reduced relative to control cells upon HIV-1 infection. To protect these cells from HIV-1 infection, we co-expressed two anti-HIV-1 shRNAs previously developed by our group together with CD4ζ. This combination vector was able to suppress HIV-1 infection without impairing HIV-1-dependent effector activities of CD4ζ. In addition, the number of CD4ζ-modified CD8{sup +} T cells maintained similar levels to that of the control even under HIV-1 infection. These results suggest that protecting CD4ζ-modified CD8{sup +} T cells from HIV-1 infection is required for prolonged HIV-1-specific immune surveillance. - Highlights: • Ectopic expression of CD4ζ CAR in CD8{sup +} T cells renders them susceptible to HIV-1 infection. • Co-expression of two anti-HIV-1 shRNAs protects CD4ζ CAR-modified CD8{sup +} T cells from HIV-1 infection. • Protecting CD4ζ CAR-modified CD8{sup +} T cells from HIV-1 infection suppresses its cytopathic effect.« less

Toxoplasma lymphadenitis mimicking malign axillary lymphadenopathy of a left breast mass.

PubMed

Yildirim, Ali Cihat; Bostanci, Hasan; Yilmaz, Engin Deniz; Kutluer, Nizamettin; Kargici, Hulagu

2013-06-01

Toxoplasmosis is an infection caused by the intracellular parasite, Toxoplasma gondii. Immunocompetent persons with primary infection are usually asymptomatic, but latent infection can persist for the life of the host. There is a risk of reactivating infection at a later time should the individual become immunocompromised, even if infection was asymptomatic or only mildly symptomatic initially. Axillary lymph nodes receive 85% of the lymphatic drainage from the breast. Lymph node metastases are relatively common even with invasive breast cancers ≤1 cm in size. Here, we report a case of toxoplasma lymphadenitis in a female adult patient mimicking a malign breast lymphadenopathy of a left breast mass.

Predictors of associated autoimmune diseases (AAID) in families with type 1 diabetes (T1D). Results from the Type 1 Diabetes Genetics Consortium (T1DGC)

PubMed Central

Wägner, Ana M; Santana, Ángelo; Hernández, Marta; Wiebe, Julia C; Nóvoa, Javier; Mauricio, Didac

2011-01-01

Background Type 1 diabetes (T1D) is a clinically heterogeneous disease. The presence of associated autoimmune diseases (AAID) may represent a distinct form of autoimmune diabetes, with involvement of specific mechanisms. The aim of this study was to find predictors of AAID in the Type 1 Diabetes Genetics Consortium (T1DGC) data set. Methods 3263 families with at least 2 siblings with T1D were included. Clinical information was obtained using questionnaires, anti-GAD and anti-IA-2 were measured and HLA-genotyping was performed. Siblings with T1D with and without AAID were compared and a multivariate regression analysis was performed to find predictors of AAID. T1D-associated HLA haplotypes were defined as the 4 most susceptible and protective, respectively. Results AAID was present in 14.4% of the T1D affected siblings. Age of diabetes onset, current age and time since diagnosis were higher, and there was a female predominance and more family history of AAID in the group with AAID, as well as more frequent anti-GAD and less frequent anti-IA2 positivity. Risk and protective HLA haplotype distributions were similar, though DRB1*0301-DQA1*0501-DQB1*0201 was more frequent in the group with AAID. In the multivariate analysis, female gender, age of onset, family history of AAID, time since diagnosis and anti-GAD positivity were significantly associated with AAID. Conclusions In patients with T1D, the presence of AAID is associated with female predominance, more frequent family history of AAID, later onset of T1D and more anti-GAD antibodies, despite longer duration of the disease. The predominance of certain HLA haplotypes suggests that specific mechanisms of disease may be involved. PMID:21744463

Comparison of post-contrast 3D-T1-MPRAGE, 3D-T1-SPACE and 3D-T2-FLAIR MR images in evaluation of meningeal abnormalities at 3-T MRI.

PubMed

Jeevanandham, Balaji; Kalyanpur, Tejas; Gupta, Prashant; Cherian, Mathew

2017-06-01

This study was to assess the usefulness of newer three-dimensional (3D)-T 1 sampling perfection with application optimized contrast using different flip-angle evolutions (SPACE) and 3D-T 2 fluid-attenuated inversion recovery (FLAIR) sequences in evaluation of meningeal abnormalities. 78 patients who presented with high suspicion of meningeal abnormalities were evaluated using post-contrast 3D-T 2 -FLAIR, 3D-T 1 magnetization-prepared rapid gradient-echo (MPRAGE) and 3D-T 1 -SPACE sequences. The images were evaluated independently by two radiologists for cortical gyral, sulcal space, basal cisterns and dural enhancement. The diagnoses were confirmed by further investigations including histopathology. Post-contrast 3D-T 1 -SPACE and 3D-T 2 -FLAIR images yielded significantly more information than MPRAGE images (p < 0.05 for both SPACE and FLAIR images) in detection of meningeal abnormalities. SPACE images best demonstrated abnormalities in dural and sulcal spaces, whereas FLAIR was useful for basal cisterns enhancement. Both SPACE and FLAIR performed equally well in detection of gyral enhancement. In all 10 patients, where both SPACE and T 2 -FLAIR images failed to demonstrate any abnormality, further analysis was also negative. The 3D-T 1 -SPACE sequence best demonstrated abnormalities in dural and sulcal spaces, whereas FLAIR was useful for abnormalities in basal cisterns. Both SPACE and FLAIR performed holds good for detection of gyral enhancement. Post-contrast SPACE and FLAIR sequences are superior to the MPRAGE sequence for evaluation of meningeal abnormalities and when used in combination have the maximum sensitivity for leptomeningeal abnormalities. The negative-predictive value is nearly 100%, where no leptomeningeal abnormality was detected on these sequences. Advances in knowledge: Post-contrast 3D-T 1 -SPACE and 3D-T 2 -FLAIR images are more useful than 3D-T 1 -MPRAGE images in evaluation of meningeal abnormalities.

Characterization of RUNX1T1, an Adipogenesis Regulator in Ovine Preadipocyte Differentiation.

PubMed

Deng, Kaiping; Ren, Caifang; Liu, Zifei; Gao, Xiaoxiao; Fan, Yixuan; Zhang, Guomin; Zhang, Yanli; Ma, Ei-Samahy; Wang, Feng; You, Peihua

2018-04-26

Runt-related transcription factor 1 translocation partner 1 (RUNX1T1), a potential novel regulator of adipogenesis, exists in two splice variants: a long (RUNX1T1-L) and a short (RUNX1T1-S) isoform. However, there is no data showing the existence of RUNX1T1 in ovine subcutaneous fat at different stages of developmental and its role on ovine adipogenesis. Therefore, the objectives of this study were to evaluate the presence of RUNX1T1 in subcutaneous fat of five-day-old to 24-month-old sheep and to investigate the role of RUNX1T1 in ovine adipogenesis. In this study, we detected a 1829 bp cDNA fragment of RUNX1T1 which contains a 1815 bp coding sequence that encodes 602-amino acid and 14 bp of 5' untranslated region, respectively. The amino acid sequence of RUNX1T1 has 31.18⁻94.21% homology with other species' protein sequences. During fat development, the RUNX1T1 protein expression was higher in subcutaneous fat of 24-month-old Hu sheep. In addition, the expression of RUNX1T1-L mRNA decreased first, then subsequently increased during ovine preadipocyte differentiation. Knockdown of RUNX1T1-L in ovine preadipocytes promoted preadipocyte differentiation and lipid accumulation. Taken together, our data suggests that RUNX1T1 is an important functional molecule in adipogenesis. Moreover, it showed for the first time that RUNX1T1-L was negatively correlated with the ovine preadipocyte differentiation.

Orthokeratinised odontogenic cyst mimicking periapical cyst

PubMed Central

Rajalakshmi, R; Sreeja, C; Vijayalakshmi, D; Leelarani, V

2013-01-01

Orthokeratinised odontogenic cyst (OOC) denotes the odontogenic cyst that microscopically has an orthokeratinised epithelial lining. OOC is characterised by a less-aggressive behaviour and a low rate of recurrence. This report describes a case of OOC involving posterior part of the mandible that mimicked periapical cyst in a 14-year-old boy. The initial clinical diagnosis was given as periapical cyst based on the clinical and radiographical features. Enucleation of the cyst was performed and the specimen was sent for histopathological examination. A definite diagnosis of OOC was made by histopathological examination of the biopsy specimen. This case emphases on including OOC in the differential diagnosis of radiolucencies occurring in the periapical region of non-vital tooth. PMID:24099763

Orthokeratinised odontogenic cyst mimicking periapical cyst.

PubMed

Rajalakshmi, R; Sreeja, C; Vijayalakshmi, D; Leelarani, V

2013-10-07

Orthokeratinised odontogenic cyst (OOC) denotes the odontogenic cyst that microscopically has an orthokeratinised epithelial lining. OOC is characterised by a less-aggressive behaviour and a low rate of recurrence. This report describes a case of OOC involving posterior part of the mandible that mimicked periapical cyst in a 14-year-old boy. The initial clinical diagnosis was given as periapical cyst based on the clinical and radiographical features. Enucleation of the cyst was performed and the specimen was sent for histopathological examination. A definite diagnosis of OOC was made by histopathological examination of the biopsy specimen. This case emphases on including OOC in the differential diagnosis of radiolucencies occurring in the periapical region of non-vital tooth.

[Effects of flower bud removal and artificial pollination on growth and yield of Tulipa edulis].

PubMed

Miao, Yuan-Yuan; Zhu, Zai-Biao; Guo, Qiao-Sheng; Ma, Hong-Liang; Yang, Ying; Zhu, Li-Fang

2014-06-01

The study was conducted to explore the response of growth and yield of Tulipa edulis to flower bud removal and artificial pollination. And flower bud removal and artificial pollination were carried out in the squaring period and bloom stage respectively. The morphological index and biomass indicators were determined and the yield was counted in harvest time. Result showed that flower bud removal was beneficial to the growth of T. edulis, resulting in increasing growth index, biomass as well as the yield of bulb. The diameter and dry weight of T. edulis fruit by artificial pollination were increased significantly compared with the control. Seed setting percentage increased to 100%, and the number of seed as well as the single grain weight increased by 69.03% and 16.48%, respectively, which did not significantly affect the bulb production. In conclusion, Flower bud removal treatment accelerates bulb biomass increase, so as to improve its yield. Artificial pollination raised significantly seed setting percentage, seed number as well as the single grain weight.

White Matter Fiber-based Analysis of T1w/T2w Ratio Map.

PubMed

Chen, Haiwei; Budin, Francois; Noel, Jean; Prieto, Juan Carlos; Gilmore, John; Rasmussen, Jerod; Wadhwa, Pathik D; Entringer, Sonja; Buss, Claudia; Styner, Martin

2017-02-01

To develop, test, evaluate and apply a novel tool for the white matter fiber-based analysis of T1w/T2w ratio maps quantifying myelin content. The cerebral white matter in the human brain develops from a mostly non-myelinated state to a nearly fully mature white matter myelination within the first few years of life. High resolution T1w/T2w ratio maps are believed to be effective in quantitatively estimating myelin content on a voxel-wise basis. We propose the use of a fiber-tract-based analysis of such T1w/T2w ratio data, as it allows us to separate fiber bundles that a common regional analysis imprecisely groups together, and to associate effects to specific tracts rather than large, broad regions. We developed an intuitive, open source tool to facilitate such fiber-based studies of T1w/T2w ratio maps. Via its Graphical User Interface (GUI) the tool is accessible to non-technical users. The framework uses calibrated T1w/T2w ratio maps and a prior fiber atlas as an input to generate profiles of T1w/T2w values. The resulting fiber profiles are used in a statistical analysis that performs along-tract functional statistical analysis. We applied this approach to a preliminary study of early brain development in neonates. We developed an open-source tool for the fiber based analysis of T1w/T2w ratio maps and tested it in a study of brain development.

White matter fiber-based analysis of T1w/T2w ratio map

NASA Astrophysics Data System (ADS)

Chen, Haiwei; Budin, Francois; Noel, Jean; Prieto, Juan Carlos; Gilmore, John; Rasmussen, Jerod; Wadhwa, Pathik D.; Entringer, Sonja; Buss, Claudia; Styner, Martin

2017-02-01

Purpose: To develop, test, evaluate and apply a novel tool for the white matter fiber-based analysis of T1w/T2w ratio maps quantifying myelin content. Background: The cerebral white matter in the human brain develops from a mostly non-myelinated state to a nearly fully mature white matter myelination within the first few years of life. High resolution T1w/T2w ratio maps are believed to be effective in quantitatively estimating myelin content on a voxel-wise basis. We propose the use of a fiber-tract-based analysis of such T1w/T2w ratio data, as it allows us to separate fiber bundles that a common regional analysis imprecisely groups together, and to associate effects to specific tracts rather than large, broad regions. Methods: We developed an intuitive, open source tool to facilitate such fiber-based studies of T1w/T2w ratio maps. Via its Graphical User Interface (GUI) the tool is accessible to non-technical users. The framework uses calibrated T1w/T2w ratio maps and a prior fiber atlas as an input to generate profiles of T1w/T2w values. The resulting fiber profiles are used in a statistical analysis that performs along-tract functional statistical analysis. We applied this approach to a preliminary study of early brain development in neonates. Results: We developed an open-source tool for the fiber based analysis of T1w/T2w ratio maps and tested it in a study of brain development.

Antimicrobial Peptide Mimicking Primary Amine and Guanidine Containing Methacrylamide Copolymers Prepared by Raft Polymerization

PubMed Central

Exley, Sarah E.; Paslay, Lea C.; Sahukhal, Gyan S.; Abel, Brooks A.; Brown, Tyler D.; McCormick, Charles L.; Heinhorst, Sabine; Koul, Veena; Choudhary, Veena; Elasri, Mohamed O.; Morgan, Sarah E.

2016-01-01

Naturally occurring antimicrobial peptides (AMPs) display the ability to eliminate a wide variety of bacteria, without toxicity to the host eukaryotic cells. Synthetic polymers containing moieties mimicking lysine and arginine components found in AMPs have been reported to show effectiveness against specific bacteria, with the mechanism of activity purported to depend on the nature of the amino acid mimic. In an attempt to incorporate the antimicrobial activity of both amino acids into a single water-soluble copolymer, a series of copolymers containing lysine mimicking aminopropyl methacrylamide (APMA) and arginine mimicking guanadinopropyl methacrylamide (GPMA) were prepared via aqueous RAFT polymerization. Copolymers were prepared with varying ratios of the comonomers, with degree of polymerization of 35–40 and narrow molecular weight distribution to simulate naturally occurring AMPs. Antimicrobial activity was determined against Gram-negative and Gram-positive bacteria under conditions with varying salt concentration. Toxicity to mammalian cells was assessed by hemolysis of red blood cells and MTT assays of MCF-7 cells. Antimicrobial activity was observed for APMA homopolymer and copolymers with low concentrations of GPMA against all bacteria tested, with low toxicity toward mammalian cells. PMID:26558609

Automatic Emboli Detection System for the Artificial Heart

NASA Astrophysics Data System (ADS)

Steifer, T.; Lewandowski, M.; Karwat, P.; Gawlikowski, M.

In spite of the progress in material engineering and ventricular assist devices construction, thromboembolism remains the most crucial problem in mechanical heart supporting systems. Therefore, the ability to monitor the patient's blood for clot formation should be considered an important factor in development of heart supporting systems. The well-known methods for automatic embolus detection are based on the monitoring of the ultrasound Doppler signal. A working system utilizing ultrasound Doppler is being developed for the purpose of flow estimation and emboli detection in the clinical artificial heart ReligaHeart EXT. Thesystem will be based on the existing dual channel multi-gate Doppler device with RF digital processing. A specially developed clamp-on cannula probe, equipped with 2 - 4 MHz piezoceramic transducers, enables easy system setup. We present the issuesrelated to the development of automatic emboli detection via Doppler measurements. We consider several algorithms for the flow estimation and emboli detection. We discuss their efficiency and confront them with the requirements of our experimental setup. Theoretical considerations are then met with preliminary experimental findings from a) flow studies with blood mimicking fluid and b) in-vitro flow studies with animal blood. Finally, we discuss some more methodological issues - we consider several possible approaches to the problem of verification of the accuracy of the detection system.

Cartilage Delamination Flap Mimicking a Torn Medial Meniscus

PubMed Central

Bin Abd Razak, Hamid Rahmatullah; Amit Kanta, Mitra

2016-01-01

We report a case of a chondral delamination lesion due to medial parapatellar plica friction syndrome involving the medial femoral condyle. This mimicked a torn medial meniscus in clinical and radiological presentation. Arthroscopy revealed a chondral delamination flap, which was debrided. Diagnosis of chondral lesions in the knee can be challenging. Clinical examination and MRI have good accuracy for diagnosis and should be used in tandem. Early diagnosis and treatment of chondral lesions are important to prevent progression to early osteoarthritis. PMID:28070434

[Artificial organs].

PubMed

Raguin, Thibaut; Dupret-Bories, Agnès; Debry, Christian

2017-01-01

Research has been fighting against organ failure and shortage of donations by supplying artificial organs for many years. With the raise of new technologies, tissue engineering and regenerative medicine, many organs can benefit of an artificial equivalent: thanks to retinal implants some blind people can visualize stimuli, an artificial heart can be proposed in case of cardiac failure while awaiting for a heart transplant, artificial larynx enables laryngectomy patients to an almost normal life, while the diabetic can get a glycemic self-regulation controlled by smartphones with an artificial device. Dialysis devices become portable, as well as the oxygenation systems for terminal respiratory failure. Bright prospects are being explored or might emerge in a near future. However, the retrospective assessment of putative side effects is not yet sufficient. Finally, the cost of these new devices is significant even if the advent of three dimensional printers may reduce it. © 2017 médecine/sciences – Inserm.

Recent ARPES experiments on quasi-1D bulk materials and artificial structures.

PubMed

Grioni, M; Pons, S; Frantzeskakis, E

2009-01-14

The spectroscopy of quasi-one-dimensional (1D) systems has been a subject of strong interest since the first experimental observations of unusual line shapes in the early 1990s. Angle-resolved photoemission (ARPES) measurements performed with increasing accuracy have greatly broadened our knowledge of the properties of bulk 1D materials and, more recently, of artificial 1D structures. They have yielded a direct view of 1D bands, of open Fermi surfaces, and of characteristic instabilities. They have also provided unique microscopic evidence for the non-conventional, non-Fermi-liquid, behavior predicted by theory, and for strong and singular interactions. Here we briefly review some of the remarkable experimental results obtained in the last decade.

A new step toward the artificial ovary: survival and proliferation of isolated murine follicles after autologous transplantation in a fibrin scaffold.

PubMed

Luyckx, Valérie; Dolmans, Marie-Madeleine; Vanacker, Julie; Legat, Camille; Fortuño Moya, Cristina; Donnez, Jacques; Amorim, Christiani Andrade

2014-04-01

To create an artificial ovary to provide an alternative way of restoring fertility in patients who cannot benefit from transplantation of cryopreserved ovarian tissue due to the threat of reintroducing malignant cells. In vivo experimental study. Gynecology research unit in a university hospital. Six-week-old female NMRI mice. Autografting of isolated preantral follicles and ovarian cells (OCs) encapsulated in two fibrin matrices containing low concentrations of fibrinogen (F; mg/mL) and thrombin (T; IU/mL): F12.5/T1 and F25/T4. Follicular density and development, OC survival and proliferation, inflammatory response, and vascularization. After 1 week, the follicle recovery rate ranged from 30.8% (F25/T4) to 31.8% (F12.5/T1). With both fibrin formulations, all follicles were found to be alive or minimally damaged, as demonstrated by terminal deoxynucleotide transferase-mediated dUTP nick-end labeling assay, and at the growing stage (primary, secondary, and antral follicles), confirmed by Ki67 immunostaining. Isolated OCs also survived and proliferated after grafting, as evidenced by <1% apoptotic cells and a high proportion of Ki67-positive cells. Vessels were found in both fibrin formulations, and the global vascular surface area varied from 1.35% (F25/T4) to 1.88% (F12.5/T1). Numerous CD45-positive cells were also observed in both F25/T4 and F12.5/T1 combinations. The present study is the first to show survival and growth of isolated murine ovarian follicles 1 week after autotransplantation of isolated OCs in a fibrin scaffold. The results indicate that fibrin is a promising candidate as a matrix for the construction of an artificial ovary. Xenotransplantation of isolated human follicles and OCs is the necessary next step to validate these findings. Copyright © 2014 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

Effects of artificial sweeteners on body weight, food and drink intake.

PubMed

Polyák, Eva; Gombos, K; Hajnal, B; Bonyár-Müller, K; Szabó, Sz; Gubicskó-Kisbenedek, A; Marton, K; Ember, I

2010-12-01

Artificial sweeteners are widely used all over the world. They may assist in weight management, prevention of dental caries, control of blood glucose of diabetics, and also can be used to replace sugar in foods. In the animal experimentation mice were given oral doses of water solutions of table top artificial sweeteners (saccharin, cyclamate based, acesulfame-K based, and aspartame) the amount of maximum Acceptable Daily Intake (ADI) ad libitum. The controls received only tap water with the same drinking conditions as the treated groups. The mice were fed chow ad libitum.We measured food intake and body weight once a week, water and solutions of artificial sweeteners intake twice a week. The data were analysed by statistical methods (T-probe, regression analysis).Consumption of sweeteners resulted in significantly increased body weight; however, the food intake did not change.These results question the effect of non-caloric artificial sweeteners on weight-maintenance or body weight decrease.

The Transforming Growth Factor-β1 (TGF-β1) Gene Polymorphisms (TGF-β1 T869C and TGF-β1 T29C) and Susceptibility to Postmenopausal Osteoporosis

PubMed Central

Sun, Jiajia; Zhang, Chi; Xu, Lei; Yang, Mingyuan; Yang, Huilin

2015-01-01

Abstract The aim of the present study was to integrate all the eligible studies and investigate whether the transforming growth factor-β1 (TGF-β1) gene polymorphisms (TGF-β1 T869C and TGF-β1 T29C) are correlated with postmenopausal osteoporosis (PMOP) risk. PMOP is a common skeletal disease and several genetic factors play an important role in the development and progression of PMOP. Significant associations between TGF-β1 gene polymorphisms (TGF-β1 T869C and TGF-β1 T29C) and PMOP risk have been reported; however, some of these results are controversial. A systematic online search was performed using PubMed, EMBASE, Web of Science, and the Cochrane Library to identify case–control studies investigating the relationship between TGF-β1 T869C and TGF-β1 T29C polymorphisms and the susceptibility of PMOP. The pooled odds ratio (OR) with 95% confidence interval (95% CI) was calculated to assess the associations, and subgroup meta-analyses were performed according to the ethnicity of the study populations. Eight studies involving 1851 cases and 2247 controls met the inclusion criteria after assessment by 2 reviewers. Overall, there were significant associations between TGF-β1 T869C and TGF-β1 T29C polymorphisms and PMOP (TGF-β1 T869C—C vs T: OR = 1.18, 95% CI = 1.02–1.36, P = 0.030; CC vs TT: OR = 1.38, 95% CI = 1.01–1.88, P = 0.042; CC vs CT/TT: OR = 1.39, 95% CI = 1.09–1.76, P = 0.008; TGF-β1 T29C—CT vs TT: OR = 1.25, 95% CI = 1.02–1.53, P = 0.032; CT/CC vs TT: OR = 1.37, 95% CI = 1.02–1.84, P = 0.035). In the subgroup analysis of ethnicity, significant association was observed between TGF-β1 T869C polymorphism and PMOP risk in Asian population (C vs T: OR = 1.18, 95% CI = 1.01–1.38, P = 0.043; CC vs TT: OR = 1.41, 95% CI = 1.01–1.97, P = 0.047; CT/CC vs TT: OR = 1.31, 95% CI = 1.03–1.66, P = 0.026; CC vs CT/TT: OR = 1.35, 95% CI�

T1 and T2 Mapping in Cardiology: "Mapping the Obscure Object of Desire".

PubMed

Mavrogeni, Sophie; Apostolou, Dimitris; Argyriou, Panayiotis; Velitsista, Stella; Papa, Lilika; Efentakis, Stelios; Vernardos, Evangelos; Kanoupaki, Mikela; Kanoupakis, George; Manginas, Athanassios

The increasing use of cardiovascular magnetic resonance (CMR) is based on its capability to perform biventricular function assessment and tissue characterization without radiation and with high reproducibility. The use of late gadolinium enhancement (LGE) gave the potential of non-invasive biopsy for fibrosis quantification. However, LGE is unable to detect diffuse myocardial disease. Native T1 mapping and extracellular volume fraction (ECV) provide knowledge about pathologies affecting both the myocardium and interstitium that is otherwise difficult to identify. Changes of myocardial native T1 reflect cardiac diseases (acute coronary syndromes, infarction, myocarditis, and diffuse fibrosis, all with high T1) and systemic diseases such as cardiac amyloid (high T1), Anderson-Fabry disease (low T1), and siderosis (low T1). The ECV, an index generated by native and post-contrast T1 mapping, measures the cellular and extracellular interstitial matrix (ECM) compartments. This myocyte-ECM dichotomy has important implications for identifying specific therapeutic targets of great value for heart failure treatment. On the other hand, T2 mapping is superior compared with myocardial T1 and ECM for assessing the activity of myocarditis in recent-onset heart failure. Although these indices can significantly affect the clinical decision making, multicentre studies and a community-wide approach (including MRI vendors, funding, software, contrast agent manufacturers, and clinicians) are still missing. © 2017 S. Karger AG, Basel.

Candida tropicalis biofilms: artificial urine, urinary catheters and flow model.

PubMed

Negri, Melyssa; Silva, Sónia; Henriques, Mariana; Azeredo, Joana; Svidzinski, Terezinha; Oliveira, Rosário

2011-10-01

Adhesion to medical devices and biofilm formation are considered important virulence factors of Candida tropicalis. This work aimed to use artificial urine (AU) and urinary catheters, under flow conditions, for studying C. tropicalis biofilms. Adhesion and biofilm formation on silicone and latex urinary catheters were quantified by crystal violet staining and determination of colony forming units. Candida surface hydrophobicity was also evaluated, as well as the biofilms' matrix content in terms of proteins and carbohydrates. Candida tropicalis was able to adhere and to form biofilms along the entire length of the catheters under flow conditions. It was found that the isolate U69 adhered significantly more to both types of catheters than did the reference strain. However, U69 biofilms contained significantly less cultivable cells and higher biofilm biomass than those of the reference strain. Detachment of cells from biofilms on latex catheter was lower compared to silicone catheter. This model using AU appeared to be suitable for studies mimicking the real body conditions. Additionally, C. tropicalis was in fact able to colonize urinary catheters in the presence of AU and to detach from these catheters, demonstrating their capacity to colonize distal sites.

Cardiac differentiation of cardiosphere-derived cells in scaffolds mimicking morphology of the cardiac extracellular matrix.

PubMed

Xu, Yanyi; Patnaik, Sourav; Guo, Xiaolei; Li, Zhenqing; Lo, Wilson; Butler, Ryan; Claude, Andrew; Liu, Zhenguo; Zhang, Ge; Liao, Jun; Anderson, Peter M; Guan, Jianjun

2014-08-01

Stem cell therapy has the potential to regenerate heart tissue after myocardial infarction (MI). The regeneration is dependent upon cardiac differentiation of the delivered stem cells. We hypothesized that timing of the stem cell delivery determines the extent of cardiac differentiation as cell differentiation is dependent on matrix properties such as biomechanics, structure and morphology, and these properties in cardiac extracellular matrix (ECM) continuously vary with time after MI. In order to elucidate the relationship between ECM properties and cardiac differentiation, we created an in vitro model based on ECM-mimicking fibers and a type of cardiac progenitor cell, cardiosphere-derived cells (CDCs). A simultaneous fiber electrospinning and cell electrospraying technique was utilized to fabricate constructs. By blending a highly soft hydrogel with a relatively stiff polyurethane and modulating fabrication parameters, tissue constructs with similar cell adhesion property but different global modulus, single fiber modulus, fiber density and fiber alignment were achieved. The CDCs remained alive within the constructs during a 1week culture period. CDC cardiac differentiation was dependent on the scaffold modulus, fiber volume fraction and fiber alignment. Two constructs with relatively low scaffold modulus, ∼50-60kPa, most significantly directed the CDC differentiation into mature cardiomyocytes as evidenced by gene expressions of cardiac troponin T (cTnT), calcium channel (CACNA1c) and cardiac myosin heavy chain (MYH6), and protein expressions of cardiac troponin I (cTnI) and connexin 43 (CX43). Of these two low-modulus constructs, the extent of differentiation was greater for lower fiber alignment and higher fiber volume fraction. These results suggest that cardiac ECM properties may have an effect on cardiac differentiation of delivered stem cells. Copyright © 2014 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

RETRACTED: Relationship between the ACE I/D gene polymorphism and T1DN susceptibility/risk of T1DM developing into T1DN in the Caucasian population.

PubMed

Zhou, Tian-Biao; Guo, Xue-Feng; Jiang, Zongpei; Li, Hong-Yan

2015-12-01

The following article has been included in a multiple retraction: Tian-Biao Zhou, Xue-Feng Guo, Zongpei Jiang, and Hong-Yan Li Relationship between the ACE I/D gene polymorphism and T1DN susceptibility/risk of T1DM developing into T1DN in the Caucasian population Journal of Renin-Angiotensin-Aldosterone System 1470320314563425, first published on February 1, 2015 doi: 10.1177/1470320314563425 This article has been retracted at the request of the Editors and the Publisher. After conducting a thorough investigation, SAGE found that the submitting authors of a number of papers published in the Journal of the Renin-Angiotensin Aldosterone System ( JRAAS) (listed below) had supplied fabricated contact details for their nominated reviewers. The Editors accepted these papers based on the reports supplied by the individuals using these fake reviewer email accounts. After concluding that the peer review process was therefore seriously compromised, SAGE and the journal Editors have decided to retract all affected articles. Online First articles (these articles will not be published in an issue) Wenzhuang Tang, Tian-Biao Zhou, and Zongpei Jiang Association of the angiotensinogen M235T gene polymorphism with risk of diabetes mellitus developing into diabetic nephropathy Journal of Renin-Angiotensin-Aldosterone System 1470320314563426, first published on December 18, 2014 doi: 10.1177/1470320314563426 Tian-Biao Zhou, Hong-Yan Li, Zong-Pei Jiang, Jia-Fan Zhou, Miao-Fang Huang, and Zhi-Yang Zhou Role of renin-angiotensin-aldosterone system inhibitors in radiation nephropathy Journal of Renin-Angiotensin-Aldosterone System 1470320314563424, first published on December 18, 2014 doi: 10.1177/1470320314563424 Weiqiang Zhong, Zongpei Jiang, and Tian-Biao Zhou Association between the ACE I/D gene polymorphism and T2DN susceptibility: The risk of T2DM developing into T2DN in the Asian population Journal of Renin-Angiotensin-Aldosterone System 1470320314566019, first published on January

A carbon nanotube-polymer composite for T-cell therapy

NASA Astrophysics Data System (ADS)

Fadel, Tarek R.; Sharp, Fiona A.; Vudattu, Nalini; Ragheb, Ragy; Garyu, Justin; Kim, Dongin; Hong, Enping; Li, Nan; Haller, Gary L.; Pfefferle, Lisa D.; Justesen, Sune; Harold, Kevin C.; Fahmy, Tarek M.

2014-08-01

Clinical translation of cell therapies requires strategies that can manufacture cells efficiently and economically. One promising way to reproducibly expand T cells for cancer therapy is by attaching the stimuli for T cells onto artificial substrates with high surface area. Here, we show that a carbon nanotube-polymer composite can act as an artificial antigen-presenting cell to efficiently expand the number of T cells isolated from mice. We attach antigens onto bundled carbon nanotubes and combined this complex with polymer nanoparticles containing magnetite and the T-cell growth factor interleukin-2 (IL-2). The number of T cells obtained was comparable to clinical standards using a thousand-fold less soluble IL-2. T cells obtained from this expansion were able to delay tumour growth in a murine model for melanoma. Our results show that this composite is a useful platform for generating large numbers of cytotoxic T cells for cancer immunotherapy.

Home artificial nutrition in advanced cancer patients.

PubMed

Ruggeri, Enrico; Agostini, Federica; Fettucciari, Luana; Giannantonio, Marilena; Pironi, Loris; Pannuti, Franco

2013-01-01

Malnutrition is over 50% in advanced cancer patients and is related to a decreased survival. Cachexia is the first reason for death in 4-23% of cases. The aim of the study was to estimate the appropriateness of the criteria to select patients for home artificial nutrition and its effectiveness to avoid death from cachexia and to improve quality of life in patients with advanced cancer assisted at home by the National Tumor Association (ANT) Foundation. The criteria for patient selection are: inadequate caloric intake ± malnutrition; life expectancy ≥6 weeks; suitable psycho-physical conditions; informed consent. The measured parameters were sex, age, tumor site, food intake, nutritional status, Karnofsky performance status, indication for home artificial nutrition, type of home artificial nutrition (enteral or parenteral), and survival after starting home artificial nutrition. The ANT Foundation assisted 29,348 patients in Bologna and its province from July 1990 to July 2012. Home artificial nutrition had been submitted to 618 patients (2.1%): enteral to 285/618 (46.1%) and parenteral to 333/618 (53.9%). Access routes for home artificial nutrition were: 39% nasogastric tube, 26% percutaneous endoscopic gastrostomy, 33% digiunostomy, and 2% gastrostomy. The central venous catheters used for home artificial nutrition were: 61% non-tunneled, 13 peripherally inserted, 8% partially tunneled, and 18% totally implanted. By July 2012, all the patients had died. Duration of life ≥6 weeks was 78% (484/618). Karnofsky performance status was related to survival ( P <0.0001): one month after starting home artificial nutrition, it decreased in 73 patients (12%), was unchanged in 414 (67%), and increased in 131 (21%). The low incidence of home artificial nutrition over all the patients assisted by the ANT Foundation and the achievement to avoid death from cachexia in 78% prove the efficacy of the criteria of patient selection in order to prevent its excessive and

Crystallographic structure and superconductive properties of Nb-Ti films with an artificially layered structure

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sato, N.

1990-06-15

Artificially layered niobium-titanium (Nb-Ti) films with various thickness ratios (3/1--1/3) and periodicities (2--100 A) are made in an argon or in a mixed argon/nitrogen atmosphere by a dc magnetron sputtering method. Films with small periodicities (less than 30 A) have an artificial superlattice structure (ASL) with crystallographic coherence between constituent layers, where Nb and Ti grow epitaxially on the closest planes. The crystallographic structures of films are bcc with the (110) plane parallel to the film for films with the same or a thicker Nb layer than a Ti layer, and hcp with the (001) plane parallel to the filmmore » for films with a thinner Nb layer than a Ti layer. Films with large periodicities have an artificial superstructure (ASS) with only periodic stacking of constituent layers. Films deposited in the Ar/N atmosphere also have the artificially layered structures of ASL or ASS. The artificially layered structure is thermally stable at temperatures up to 500 {degree}C. The superconducting properties of the films depend strongly on the periodicity and thickness ratio of Nb and Ti layers. The dependence of the transition temperature on the periodicity and thickness ratio is qualitatively explained by a proximity effect with a three-region model. Films with periodicities less than 20 A, composed of the same or a thicker Nb layer than a Ti layer, show high transition temperatures (above 9.3 K). The highest {ital T}{sub {ital c}} of about 13.6 K is obtained in the film composed of monatomic layers of constituents deposited in an Ar atmosphere including 30 vol % N.« less

Addison's Disease Mimicking as Acute Pancreatitis: A Case Report.

PubMed

Chaudhuri, Sayani; Rao, Karthik N; Patil, Navin; Ommurugan, Balaji; Varghese, George

2017-04-01

Over past two decades there has been significant improvement in medical field in elucidating the underlying pathophysiology and genetics of Addison's disease. Adrenal insufficiency (Addison's disease) is a rare disease with an incidence of 0.8/100,000 cases. The diagnosis may be delayed if the clinical presentation mimics a gastrointestinal disorder or psychiatric illness. We report a case of Addison's disease presenting as acute pain in abdomen mimicking clinical presentation of acute pancreatitis.

Epigenetic heterogeneity affects the risk of relapse in children with t(8;21)RUNX1-RUNX1T1-rearranged AML.

PubMed

Zampini, Matteo; Tregnago, Claudia; Bisio, Valeria; Simula, Luca; Borella, Giulia; Manara, Elena; Zanon, Carlo; Zonta, Francesca; Serafin, Valentina; Accordi, Benedetta; Campello, Silvia; Buldini, Barbara; Pession, Andrea; Locatelli, Franco; Basso, Giuseppe; Pigazzi, Martina

2018-05-01

The somatic translocation t(8;21)(q22;q22)/RUNX1-RUNX1T1 is one of the most frequent rearrangements found in children with standard-risk acute myeloid leukemia (AML). Despite the favorable prognostic role of this aberration, we recently observed a higher than expected frequency of relapse. Here, we employed an integrated high-throughput approach aimed at identifying new biological features predicting relapse among 34 t(8;21)-rearranged patients. We found that the DNA methylation status of patients who suffered from relapse was peculiarly different from that of children maintaining complete remission. The epigenetic signature, made up of 337 differentially methylated regions, was then integrated with gene and protein expression profiles, leading to a network, where cell-to-cell adhesion and cell-motility pathways were found to be aberrantly activated in relapsed patients. We identified most of these factors as RUNX1-RUNX1T1 targets, with Ras Homolog Family Member (RHOB) overexpression being the core of this network. We documented how RHOB re-organized the actin cytoskeleton through its downstream ROCK-LIMK-COFILIN axis: this increases blast adhesion by stress fiber formation, and reduces mitochondrial apoptotic cell death after chemotherapy treatment. Altogether, our data show an epigenetic heterogeneity within t(8;21)-rearranged AML patients at diagnosis able to influence the program of the chimeric transcript, promoting blast re-emergence and progression to relapse.

Bibliography: Artificial Intelligence.

ERIC Educational Resources Information Center

Smith, Richard L.

1986-01-01

Annotates reference material on artificial intelligence, mostly at an introductory level, with applications to education and learning. Topics include: (1) programing languages; (2) expert systems; (3) language instruction; (4) tutoring systems; and (5) problem solving and reasoning. (JM)

mTORC1 promotes T-bet phosphorylation to regulate Th1 differentiation

PubMed Central

Chornoguz, Olesya; Hagan, Robert S.; Haile, Azeb; Arwood, Matthew L.; Gamper, Christopher J.; Banerjee, Arnob; Powell, Jonathan D.

2017-01-01

CD4+ T cells lacking the mTORC1 activator Rheb fail to secrete IFNγ under Th1 polarizing conditions. We hypothesized that this phenotype is due to defects in regulation of the canonical Th1 transcription factor T-bet at the level of protein phosphorylation downstream of mTORC1. To test this hypothesis, we employed targeted mass-spectrometry proteomic analysis – multiple reaction monitoring mass spectrometry (MRM-MS). We used MRM-MS to detect and quantify predicted phospho-peptides derived from T-bet. By analyzing activated murine WT and Rheb deficient CD4+ T cells, as well as murine CD4+ T cells activated in the presence of rapamycin, a pharmacologic inhibitor of mTORC1, we were able to identify 6 T-bet phosphorylation sites. Five of these are novel, and 4 sites are consistently dephosphorylated in both Rheb deficient CD4+ T-cells and T-cells treated with rapamycin, suggesting mTORC1 signaling controls their phosphorylation. Alanine mutagenesis of each of the 6 phosphorylation sites was tested for the ability to impair IFNγ expression. Single phosphorylation site mutants still support induction of IFNγ expression, however simultaneous mutation of 3 of the mTORC1-dependent sites results in significantly reduced IFNγ expression. The reduced activity of the triple mutant T-bet is associated with its failure to recruit chromatin remodeling complexes to the Ifng gene promoter. These results establish a novel mechanism by which mTORC1 regulates Th1 differentiation, through control of T-bet phosphorylation. PMID:28424242

[Simulation of lung motions using an artificial neural network].

PubMed

Laurent, R; Henriet, J; Salomon, M; Sauget, M; Nguyen, F; Gschwind, R; Makovicka, L

2011-04-01

A way to improve the accuracy of lung radiotherapy for a patient is to get a better understanding of its lung motion. Indeed, thanks to this knowledge it becomes possible to follow the displacements of the clinical target volume (CTV) induced by the lung breathing. This paper presents a feasibility study of an original method to simulate the positions of points in patient's lung at all breathing phases. This method, based on an artificial neural network, allowed learning the lung motion on real cases and then to simulate it for new patients for which only the beginning and the end breathing data are known. The neural network learning set is made up of more than 600 points. These points, shared out on three patients and gathered on a specific lung area, were plotted by a MD. The first results are promising: an average accuracy of 1mm is obtained for a spatial resolution of 1 × 1 × 2.5mm(3). We have demonstrated that it is possible to simulate lung motion with accuracy using an artificial neural network. As future work we plan to improve the accuracy of our method with the addition of new patient data and a coverage of the whole lungs. Copyright © 2010 Société française de radiothérapie oncologique (SFRO). Published by Elsevier SAS. All rights reserved.

Evaluation of neonatal brain myelination using the T1- and T2-weighted MRI ratio.

PubMed

Soun, Jennifer E; Liu, Michael Z; Cauley, Keith A; Grinband, Jack

2017-09-01

To validate the T1- and T2-weighted (T1w/T2w) MRI ratio technique in evaluating myelin in the neonatal brain. T1w and T2w MR images of 10 term neonates with normal-appearing brain parenchyma were obtained from a single 1.5 Tesla MRI and retrospectively analyzed. T1w/T2w ratio images were created with a postprocessing pipeline and qualitatively compared with standard clinical sequences (T1w, T2w, and apparent diffusion coefficient [ADC]). Quantitative assessment was also performed to assess the ratio technique in detecting areas of known myelination (e.g., posterior limb of the internal capsule) and very low myelination (e.g., optic radiations) using linear regression analysis and the Michelson Contrast equation, a measure of luminance contrast intensity. The ratio image provided qualitative improvements in the ability to visualize regional variation in myelin content of neonates. Linear regression analysis demonstrated a significant inverse relationship between the ratio intensity values and ADC values in the posterior limb of the internal capsule and the optic radiations (R 2  = 0.96 and P < 0.001). The Michelson Contrast equation showed that contrast differences between these two regions for the ratio images were 1.6 times higher than T1w, 2.6 times higher than T2w, and 1.8 times higher than ADC (all P < 0.001). Finally, the ratio improved visualization of the corticospinal tract, one of the earliest myelinated pathways. The T1w/T2w ratio accentuates contrast between myelinated and less myelinated structures and may enhance our diagnostic ability to detect myelination patterns in the neonatal brain. 2 Technical Efficacy: Stage2 J. MAGN. RESON. IMAGING 2017;46:690-696. © 2016 International Society for Magnetic Resonance in Medicine.

Measurement of T1 of the Ultrashort T2* Components in White Matter of the Brain at 3T

PubMed Central

Du, Jiang; Sheth, Vipul; He, Qun; Carl, Michael; Chen, Jun; Corey-Bloom, Jody; Bydder, Graeme M.

2014-01-01

Recent research demonstrates that white matter of the brain contains not only long T2 components, but a minority of ultrashort T2* components. Adiabatic inversion recovery prepared dual echo ultrashort echo time (IR-dUTE) sequences can be used to selectively image the ultrashort T2* components in white matter of the brain using a clinical whole body scanner. The T2*s of the ultrashort T2* components can be quantified using mono-exponential decay fitting of the IR-dUTE signal at a series of different TEs. However, accurate T1 measurement of the ultrashort T2* components is technically challenging. Efficient suppression of the signal from the majority of long T2 components is essential for robust T1 measurement. In this paper we describe a novel approach to this problem based on the use of IR-dUTE data acquisitions with different TR and TI combinations to selectively detect the signal recovery of the ultrashort T2* components. Exponential recovery curve fitting provides efficient T1 estimation, with minimized contamination from the majority of long T2 components. A rubber phantom and a piece of bovine cortical bone were used for validation of this approach. Six healthy volunteers were studied. An averaged T2* of 0.32±0.09 ms, and a short mean T1 of 226±46 ms were demonstrated for the healthy volunteers at 3T. PMID:25093859

Phase transformation of dental zirconia following artificial aging.

PubMed

Lucas, Thomas J; Lawson, Nathaniel C; Janowski, Gregg M; Burgess, John O

2015-10-01

Low-temperature degradation (LTD) of yttria-stabilized zirconia can produce increased surface roughness with a concomitant decrease in strength. This study determined the effectiveness of artificial aging (prolonged boiling/autoclaving) to induce LTD of Y-TZP (yttria-tetragonal zirconia-polycrystals) and used artificial aging for transformation depth progression analyses. The null hypothesis is aging techniques tested produce the same amount of transformation, transformation is not time/temperature dependent and LTD causes a constant transformation throughout the Y-TZP samples. Dental-grade Y-TZP samples were randomly divided into nine subgroups (n = 5): as received, 3.5 and 7 day boiling, 1 bar autoclave (1, 3, 5 h), and 2 bar autoclave (1, 3, 5 h). A 4-h boil treatment (n = 2) was performed post-experiment for completion of data. Transformation was measured using traditional X-ray diffraction and low-angle X-ray diffraction. The fraction of t → m transformation increased with aging time. The 3.5 day boil and 2 bar 5 h autoclave produced similar transformation results, while the 7 day boiling treatment revealed the greatest transformation. The surface layer of the aged specimen underwent the most transformation while all samples displayed decreasing transformation with depth. Surface transformation was evident, which can lead to rougher surfaces and increased wear of opposing dentition/materials. Therefore, wear studies addressing LTD of Y-TZP are needed utilizing accelerated aging. © 2014 Wiley Periodicals, Inc.

26 CFR 1.923-1T - Temporary regulations; exempt foreign trade income.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 26 Internal Revenue 10 2010-04-01 2010-04-01 false Temporary regulations; exempt foreign trade income. 1.923-1T Section 1.923-1T Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) INCOME TAX (CONTINUED) INCOME TAXES Earned Income of Citizens of United States § 1.923-1T Temporary regulations; exempt foreign trade...

26 CFR 1.923-1T - Temporary regulations; exempt foreign trade income.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 26 Internal Revenue 10 2012-04-01 2012-04-01 false Temporary regulations; exempt foreign trade income. 1.923-1T Section 1.923-1T Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) INCOME TAX (CONTINUED) INCOME TAXES (CONTINUED) Earned Income of Citizens of United States § 1.923-1T Temporary regulations; exempt...

Saturation-inversion-recovery: A method for T1 measurement

NASA Astrophysics Data System (ADS)

Wang, Hongzhi; Zhao, Ming; Ackerman, Jerome L.; Song, Yiqiao

2017-01-01

Spin-lattice relaxation (T1) has always been measured by inversion-recovery (IR), saturation-recovery (SR), or related methods. These existing methods share a common behavior in that the function describing T1 sensitivity is the exponential, e.g., exp(- τ /T1), where τ is the recovery time. In this paper, we describe a saturation-inversion-recovery (SIR) sequence for T1 measurement with considerably sharper T1-dependence than those of the IR and SR sequences, and demonstrate it experimentally. The SIR method could be useful in improving the contrast between regions of differing T1 in T1-weighted MRI.

Structure-Based Design of Inhibitors of Protein–Protein Interactions: Mimicking Peptide Binding Epitopes

PubMed Central

Pelay-Gimeno, Marta; Glas, Adrian; Koch, Oliver; Grossmann, Tom N

2015-01-01

Protein–protein interactions (PPIs) are involved at all levels of cellular organization, thus making the development of PPI inhibitors extremely valuable. The identification of selective inhibitors is challenging because of the shallow and extended nature of PPI interfaces. Inhibitors can be obtained by mimicking peptide binding epitopes in their bioactive conformation. For this purpose, several strategies have been evolved to enable a projection of side chain functionalities in analogy to peptide secondary structures, thereby yielding molecules that are generally referred to as peptidomimetics. Herein, we introduce a new classification of peptidomimetics (classes A–D) that enables a clear assignment of available approaches. Based on this classification, the Review summarizes strategies that have been applied for the structure-based design of PPI inhibitors through stabilizing or mimicking turns, β-sheets, and helices. PMID:26119925

Third Conference on Artificial Intelligence for Space Applications, part 1

NASA Technical Reports Server (NTRS)

Denton, Judith S. (Compiler); Freeman, Michael S. (Compiler); Vereen, Mary (Compiler)

1987-01-01

The application of artificial intelligence to spacecraft and aerospace systems is discussed. Expert systems, robotics, space station automation, fault diagnostics, parallel processing, knowledge representation, scheduling, man-machine interfaces and neural nets are among the topics discussed.

A novel enterocin T1 with anti-Pseudomonas activity produced by Enterococcus faecium T1 from Chinese Tibet cheese.

PubMed

Liu, Hui; Zhang, Lanwei; Yi, Huaxi; Han, Xue; Gao, Wei; Chi, Chunliang; Song, Wei; Li, Haiying; Liu, Chunguang

2016-02-01

An enterocin-producing Enterococcus faecium T1 was isolated from Chinese Tibet cheese. The enterocin was purified by SP-Sepharose and reversed phase HPLC. It was identified as unique from other reported bacteriocins based on molecular weight (4629 Da) and amino acid compositions; therefore it was subsequently named enterocin T1. Enterocin T1 was stable at 80-100 °C and over a wide pH range, pH 3.0-10.0. Protease sensitivity was observed to trypsin, pepsin, papain, proteinase K, and pronase E. Importantly, enterocin T1 was observed to inhibit the growth of numerous Gram-negative and Gram-positive bacteria including Pseudomonas putida, Pseudomonas aeruginosa, Pseudomonas fluorescens, Escherichia coli, Salmonella typhimurium, Shigella flexneri, Shigella sonnei, Staphylococcus aureus, Listeria monocytogenes. Take together, these results suggest that enterocin T1 is a novel bacteriocin with the potential to be used as a bio-preservative to control Pseudomonas spp. in food.

Ileal Entrapment within a Paracaecal Hernia Mimicking Acute Appendicitis

PubMed Central

Birchley, David

2009-01-01

Presented is a case of incarcerated paracaecal hernia mimicking acute appendicitis. The clinical scenario highlights the need for a high index of suspicion in the management of patients with localised peritonism even in the absence of obstructive symptoms and the presence of normal laboratory markers of inflammation.Whilst computed tomography might offer a pre-operative diagnosis, in such a low-risk patient laparoscopy offers the combined advantages of immediate diagnosis and definitive treatment of acute pathology. PMID:19317924

Hybrid nanotrimers for dual T 1 and T 2-weighted magnetic resonance imaging

DOE PAGES

Cheng, Kai; Yang, Meng; Zhang, Ruiping; ...

2014-10-04

Development of multifunctional nanoparticle-based probes for dual T 1- and T 2-weighted magnetic resonance imaging (MRI) could allow us to image and diagnose the tumors or other abnormalities in an exceptionally accurate and reliable manner. In this study, by fusing distinct nanocrystals via solid-state interfaces, we built hybrid heteronanostructures to combine both T 1 and T 2- weighted contrast agents together for MRI with high accuracy and reliability. The resultant hybrid heterotrimers showed high stability in physiological conditions and could induce both simultaneous positive and negative contrast enhancements in MR images. Small animal positron emission tomography imaging study revealed thatmore » the hybrid heterostructures displayed favorable biodistribution and were suitable for in vivo imaging. Furthermore, their potential as dual contrast agents for T 1 and T 2-weighted MRI was further demonstrated by in vitro and in vivo imaging and relaxivity measurements.« less

Current topics in glycemic control by wearable artificial pancreas or bedside artificial pancreas with closed-loop system.

PubMed

Hanazaki, Kazuhiro; Munekage, Masaya; Kitagawa, Hiroyuki; Yatabe, Tomoaki; Munekage, Eri; Shiga, Mai; Maeda, Hiromichi; Namikawa, Tsutomu

2016-09-01

The incidence of diabetes is increasing at an unprecedented pace and has become a serious health concern worldwide during the last two decades. Despite this, adequate glycemic control using an artificial pancreas has not been established, although the 21st century has seen rapid developments in this area. Herein, we review current topics in glycemic control for both the wearable artificial pancreas for type 1 and type 2 diabetic patients and the bedside artificial pancreas for surgical diabetic patients. In type 1 diabetic patients, nocturnal hypoglycemia associated with insulin therapy remains a serious problem that could be addressed by the recent development of a wearable artificial pancreas. This smart phone-like device, comprising a real-time, continuous glucose monitoring system and insulin pump system, could potentially significantly reduce nocturnal hypoglycemia compared with conventional glycemic control. Of particular interest in this space are the recent inventions of a low-glucose suspend feature in the portable systems that automatically stops insulin delivery 2 h following a glucose sensor value <70 mg/dL and a bio-hormonal pump system consisting of insulin and glucagon pumps. Perioperative tight glycemic control using a bedside artificial pancreas with the closed-loop system has also proved safe and effective for not only avoiding hypoglycemia, but also for reducing blood glucose level variability resulting in good surgical outcomes. We hope that a more sophisticated artificial pancreas with closed-loop system will now be taken up for routine use worldwide, providing enormous relief for patients suffering from uncontrolled hyperglycemia, hypoglycemia, and/or variability in blood glucose concentrations.

In vitro DNA binding studies of Aspartame, an artificial sweetener.

PubMed

Kashanian, Soheila; Khodaei, Mohammad Mehdi; Kheirdoosh, Fahimeh

2013-03-05

A number of small molecules bind directly and selectively to DNA, by inhibiting replication, transcription or topoisomerase activity. In this work the interaction of native calf thymus DNA (CT-DNA) with Aspartame (APM), an artificial sweeteners was studied at physiological pH. DNA binding study of APM is useful to understand APM-DNA interaction mechanism and to provide guidance for the application and design of new and safer artificial sweeteners. The interaction was investigated using spectrophotometric, spectrofluorometric competition experiment and circular dichroism (CD). Hypochromism and red shift are shown in UV absorption band of APM. A strong fluorescence quenching reaction of DNA to APM was observed and the binding constants (Kf) of DNA with APM and corresponding number of binding sites (n) were calculated at different temperatures. Thermodynamic parameters, enthalpy changes (ΔH) and entropy changes (ΔS) were calculated to be +181kJmol(-1) and +681Jmol(-1)K(-1) according to Van't Hoff equation, which indicated that reaction is predominantly entropically driven. Moreover, spectrofluorometric competition experiment and circular dichroism (CD) results are indicative of non-intercalative DNA binding nature of APM. We suggest that APM interacts with calf thymus DNA via groove binding mode with an intrinsic binding constant of 5×10(+4)M(-1). Copyright © 2013 Elsevier B.V. All rights reserved.

Tax Protein-induced Expression of Antiapoptotic Bfl-1 Protein Contributes to Survival of Human T-cell Leukemia Virus Type 1 (HTLV-1)-infected T-cells*♦

PubMed Central

Macaire, Héloïse; Riquet, Aurélien; Moncollin, Vincent; Biémont-Trescol, Marie-Claude; Duc Dodon, Madeleine; Hermine, Olivier; Debaud, Anne-Laure; Mahieux, Renaud; Mesnard, Jean-Michel; Pierre, Marlène; Gazzolo, Louis; Bonnefoy, Nathalie; Valentin, Hélène

2012-01-01

Human T lymphotropic virus type 1 (HTLV-1) is the etiologic agent of adult T-cell leukemia/lymphoma (ATLL). ATLL is a severe malignancy with no effective treatment. HTLV-1 regulatory proteins Tax and HTLV-1 basic leucine zipper factor (HBZ) play a major role in ATLL development, by interfering with cellular functions such as CD4+ T-cell survival. In this study, we observed that the expression of Bfl-1, an antiapoptotic protein of the Bcl-2 family, is restricted to HTLV-1-infected T-cell lines and to T-cells expressing both Tax and HBZ proteins. We showed that Tax-induced bfl-1 transcription through the canonical NF-κB pathway. Moreover, we demonstrated that Tax cooperated with c-Jun or JunD, but not JunB, transcription factors of the AP-1 family to stimulate bfl-1 gene activation. By contrast, HBZ inhibited c-Jun-induced bfl-1 gene activation, whereas it increased JunD-induced bfl-1 gene activation. We identified one NF-κB, targeted by RelA, c-Rel, RelB, p105/p50, and p100/p52, and two AP-1, targeted by both c-Jun and JunD, binding sites in the bfl-1 promoter of T-cells expressing both Tax and HBZ. Analyzing the potential role of antiapoptotic Bcl-2 proteins in HTLV-1-infected T-cell survival, we demonstrated that these cells are differentially sensitive to silencing of Bfl-1, Bcl-xL, and Bcl-2. Indeed, both Bfl-1 and Bcl-xL knockdowns decreased the survival of HTLV-1-infected T-cell lines, although no cell death was observed after Bcl-2 knockdown. Furthermore, we demonstrated that Bfl-1 knockdown sensitizes HTLV-1-infected T-cells to ABT-737 or etoposide treatment. Our results directly implicate Bfl-1 and Bcl-xL in HTLV-1-infected T-cell survival and suggest that both Bfl-1 and Bcl-xL represent potential therapeutic targets for ATLL treatment. PMID:22553204