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1

The accessory function of B lymphocytes is resistant to the adverse effects of UV radiation.  

PubMed

The effect of UV radiation on the accessory activities of B lymphoblastoid cell lines (B-LCL) was investigated in three types of in vitro T lymphocyte proliferation assay, each of which differed in its accessory requirements. In contrast to monocytes whose accessory function was universally sensitive to UV radiation, B-LCL were resistant to UV in oxidative mitogenesis and staphylococcal enterotoxin B assays, in which stimulus processing was not a requirement. Expression of membrane interleukin (IL) 1 and HLA-DR antigens by B-LCL and monocytes was not affected by UV, nor was surface membrane expression of intercellular adhesion molecule-1 (ICAM-1) on B-LCL. These results were in marked contrast to monocytes in which there was a greater than 65% reduction in ICAM-1 expression. When UV-irradiated B-LCL were employed as antigen-presenting cells for tetanus toxoid-dependent T cell stimulation, a reduction in antigen-presenting function was observed. However, pulsing of B-LCL with tetanus toxoid prior to UV irradiation preserved their antigen-presenting capacity in this system also. These findings indicate that there is differential UV sensitivity among accessory cells which may be explained by different effects of UV radiation on antigen processing and adhesion molecule expression. PMID:1671836

Hertl, M; Kaplan, D R; Fayen, J D; Panuska, J R; Ellner, J J; Elmets, C A

1991-02-01

2

Functional properties of neurons in the cat gracile nucleus that project to the dorsal accessory olive  

Microsoft Academic Search

This study evaluated the functional properties of neurons in the gracile nucleus that project to the dorsal accessory portion of the inferior olive (DAO) and compared these with properties of other efferents from the dorsal column nuclei (DCN). Projection neurons were identified in anesthetized cats by microstimulation within DAO. They were further tested to insure that they could not be

H. H. Molinari; J. O. Dostrovsky

1987-01-01

3

Electrocardiographic differentiation of typical atrioventricular node reentrant tachycardia from atrioventricular reciprocating tachycardia mediated by concealed accessory pathway in children  

Microsoft Academic Search

The value of the electrocardiogram (ECG) in children with supraventricular tachycardia (SVT) is unclear. The noninvasive differentiation of typical atrioventricular node reentrant tachycardia (AVNRT) and atrioventricular reciprocating tachycardia (AVRT) mediated by concealed accessory pathway conduction is clinically important, as it helps in counseling and potentially facilitates ablation procedures. One hundred forty-eight ECGs showing narrow QRS complex SVT were obtained from

Edgar T Jaeggi; Thomas Gilljam; Urs Bauersfeld; Christine Chiu; Robert Gow

2003-01-01

4

Functional organization of glomerular maps in the mouse accessory olfactory bulb.  

PubMed

The mammalian accessory olfactory system extracts information about species, sex and individual identity from social odors, but its functional organization remains unclear. We imaged presynaptic Ca(2+) signals in vomeronasal inputs to the accessory olfactory bulb (AOB) during peripheral stimulation using light sheet microscopy. Urine- and steroid-responsive glomeruli densely innervated the anterior AOB. Glomerular activity maps for sexually mature female mouse urine overlapped maps for juvenile and/or gonadectomized urine of both sexes, whereas maps for sexually mature male urine were highly distinct. Further spatial analysis revealed a complicated organization involving selective juxtaposition and dispersal of functionally grouped glomerular classes. Glomeruli that were similarly tuned to urines were often closely associated, whereas more disparately tuned glomeruli were selectively dispersed. Maps to a panel of sulfated steroid odorants identified tightly juxtaposed groups that were disparately tuned and dispersed groups that were similarly tuned. These results reveal a modular, nonchemotopic spatial organization in the AOB. PMID:24880215

Hammen, Gary F; Turaga, Diwakar; Holy, Timothy E; Meeks, Julian P

2014-07-01

5

Differential Person Functioning.  

ERIC Educational Resources Information Center

In many testing situations, differential item functioning (DIF) is a potentially serious problem. It occurs when a test item appears to be easier for one group of examinees than another even after controlling for overall skill level. Differential person functioning (DPF) can occur when "items" can be considered raters and the persons are the…

Johanson, George; Alsmadi, Abdalla

6

Accessory proteins are vital for the functional expression of certain G protein-coupled receptors.  

PubMed

Certain G protein-coupled receptors (GPCRs) fail to be expressed in a functional form at the cell surface. This may be due to the improper folding and maturation of GPCRs which are highly intricate events that need to take place before these integral membrane proteins can be transported from the endoplasmic reticulum (ER), where they are synthesised, to the plasma membrane which is their site of action. Once at the plasma membrane they act as the recognition elements for a vast range of endogenous ligands including biogenic amines, peptides, glycoproteins, lipids, nucleotides, ions and proteases. The assistance of molecular chaperones has been widely implicated in the trafficking and function of these proteins. Characterisation of certain GPCRs has identified a novel group of membrane proteins collectively named 'accessory proteins' as being important for the expression and function of GPCRs. In this review we will summarise the importance of these accessory proteins for the function of their respective GPCRs. Understanding their roles in GPCR expression would not only give us an insight into these receptors from a cell biological point of view but may also potentially lead to the development of novel therapeutics. PMID:19000738

Cooray, Sadani N; Chan, Li; Webb, Tom R; Metherell, Louise; Clark, Adrian J L

2009-03-01

7

Ventricular Dyssynchrony and Function Improve following Catheter Ablation of Nonseptal Accessory Pathways in Children  

PubMed Central

Introduction. Paradoxical or hypokinetic interventricular septal motion has been described in patients with septal or paraseptal accessory pathways. Data regarding nonseptal pathways is limited. Methods and Results. We quantified left ventricular dyssynchrony and function in 16 consecutive children, 14.2 ± 3.7 years, weighing 53 ± 17?kg, prior to and following catheter ablation of bidirectional septal (N = 6) and nonseptal (N = 10) accessory pathways. Following ablation, the left ventricular ejection fraction increased by 4.9 ± 2.1% (P = 0.038) from a baseline value of 57.0% ± 7.8%. By tissue Doppler imaging, the interval between QRS onset and peak systolic velocity (Ts) decreased from a median of 33.0?ms to 18.0?ms (P = 0.013). The left ventricular ejection fraction increased to a greater extent following catheter ablation of nonseptal (5.9% ± 2.6%, P = 0.023) versus septal (2.5% ± 4.1%, P = 0.461) pathways. The four patients with an ejection fraction <50%, two of whom had left lateral pathways, improved to >50% after ablation. Similarly, the improvement in dyssynchrony was more marked in patients with nonseptal versus septal pathways (difference between septal and lateral wall motion delay before and after ablation 20.6 ± 7.1?ms (P = 0.015) versus 1.4 ± 11.4?ms (P = 0.655)). Conclusion. Left ventricular systolic function and dyssynchrony improve after ablation of antegrade-conducting accessory pathways in children, with more pronounced changes noted for nonseptal pathways.

Abadir, Sylvia; Fournier, Anne; Dubuc, Marc; Sarquella-Brugada, Georgia; Garceau, Patrick

2013-01-01

8

Activity regulates functional connectivity from the vomeronasal organ to the accessory olfactory bulb.  

PubMed

The mammalian accessory olfactory system is specialized for the detection of chemicals that identify kin and conspecifics. Vomeronasal sensory neurons (VSNs) residing in the vomeronasal organ project axons to the accessory olfactory bulb (AOB), where they form synapses with principal neurons known as mitral cells. The organization of this projection is quite precise and is believed to be essential for appropriate function of this system. However, how this precise connectivity is established is unknown. We show here that in mice the vomeronasal duct is open at birth, allowing external chemical stimuli access to sensory neurons, and that these sensory neurons are capable of releasing neurotransmitter to downstream neurons as early as the first postnatal day (P). Using major histocompatibility complex class I peptides to activate a selective subset of VSNs during the first few postnatal days of development, we show that increased activity results in exuberant VSN axonal projections and a delay in axonal coalescence into well defined glomeruli in the AOB. Finally, we show that mitral cell dendritic refinement occurs just after the coalescence of presynaptic axons. Such a mechanism may allow the formation of precise connectivity with specific glomeruli that receive input from sensory neurons expressing the same receptor type. PMID:22674266

Hovis, Kenneth R; Ramnath, Rohit; Dahlen, Jeffrey E; Romanova, Anna L; LaRocca, Greg; Bier, Mark E; Urban, Nathaniel N

2012-06-01

9

Structure and Function of the Melanocortin2 Receptor Accessory Protein MRAP  

PubMed Central

The melanocortin2 (MC21), or ACTH receptor, requires MC2 receptor accessory protein (MRAP) for function, and individuals lacking MRAP are ACTH-resistant and glucocorticoid-deficient. MRAP facilitates trafficking of the MC2 receptor to the plasma membrane and is absolutely required for ACTH binding and stimulation of cAMP. MRAP, which contains a single transmembrane domain, has a unique structure, an antiparallel homodimer. It can be isolated from the plasma membrane in a complex with the MC2 receptor. A short sequence just aminoterminal to the transmembrane domain of MRAP is essential for dual topology, while the transmembrane region is not; both are necessary for function. Deletion or alanine-substitution of other aminoterminal regions yields MRAP mutants that promote surface expression of the MC2 receptor but not receptor signaling. These results identify two distinct actions of MRAP: to permit trafficking of the MC2 receptor, and to allow surface receptor binding and signaling.

Hinkle, Patricia M.; Sebag, Julien A.

2009-01-01

10

Matching Accessories  

NSDL National Science Digital Library

Heterodimerization enhances the complexity of ligand recognition and diversity of signaling responses of heterotrimeric guanine nucleotide-binding protein-coupled receptors (GPCRs). Many accessory proteins (for ion channels or GPCRs) appear to associate with their partners relatively early in the process whereby proteins are transported to the cell surface; their roles in modulating function may have evolved out of simple proximity to a protein that once upon a time they either facilitated or accompanied through the maturation process. The receptor activity-modifying proteins (RAMPs) are a family of single-transmembrane accessory proteins that heterodimerize with GPCRs and, thereby, allow individual GPCRs to recognize multiple ligands and to activate various signaling pathways in response to ligand binding. The M10 family of major histocompatibility complex (MHC) class 1b proteins has recently been shown to associate with murine vomeronasal V2R receptors, as well as to escort them to the cell surface. The exact role of M10 in modulating V2R function (or vice versa) remains to be determined.

Steven M. Foord (Stevenage;Target Bioinformatics, GlaxoSmithKline Medicine Research Centre REV)

2003-07-08

11

Involvement of melanocortin receptor accessory proteins (MRAPs) in the function of melanocortin receptors.  

PubMed

The melanocortin system integrates different agonists, competitive or inverse agonists, and receptors. Recent investigations have also discovered a specific system of melanocortin receptor accessory proteins (MRAPs) that are involved in the regulation of the functional expression of these receptors. MRAP1 mutations are responsible for type 2 familial glucocorticoid deficiency (FGD2), a rare autosomal disorder characterized by high plasma adrenocorticotropin hormone (ACTH) levels but severe cortisol deficiency. ACTH binds melanocortin 2 receptor (MC2R), a G protein-coupled receptor, in the adrenal gland to promote corticosteroid synthesis. In the absence of MRAP1, MC2R cannot translocate from the endoplasmic reticulum to the plasma membrane and ACTH-induced signaling is extinguished. A second MRAP protein, called MRAP2, also modulates MC2R activity. MRAPs also interact with the other melanocortin receptors, adjusting their pharmacological properties. In this paper, we briefly review the MRAP system and its interaction with melanocortin receptors. PMID:23410915

Cerdá-Reverter, J M; Agulleiro, M J; Cortés, R; Sánchez, E; Guillot, R; Leal, E; Fernández-Durán, B; Puchol, S; Eley, M

2013-07-01

12

The functional interaction of accessory proteins and voltage-gated sodium channels  

Microsoft Academic Search

Sodium channels are important transmembrane proteins that underlie membrane excitability, including the excitability of neurons in pain pathways. The biophysical properties and densities of sodium channels are modulated by the presence of accessory ß-subunits, with the intracellular and extracellular binding properties of the ß1- subunit being particularly important in node of Ranvier formation. Other proteins interact with sodium channels, some

Kenji Okuse; Mark D. Baker

13

The Melanocortin 2 Receptor Accessory Protein Exists as a Homodimer and Is Essential for the Function of the Melanocortin 2 Receptor in the Mouse Y1 Cell Line  

Microsoft Academic Search

The ACTH receptor (melanocortin 2 receptor (MC2R)) gene produces a functional receptor only when transfected into cells of adrenocortical origin, implying that it may require an adrenal-specific accessory factor. Recently we showed that the MC2R accessory protein (MRAP) is essential for the cell surface expression of the MC2R in such models. Using RNA interference (RNAi) technology, we have further explored

Sadani N. Cooray; Isabel Almiro Do Vale; Kit-Yi Leung; Tom R. Webb; Paul Chapple; Michaela Egertova; Michael E. Cheetham; Maurice R. Elphick; Adrian J. L. Clark

2010-01-01

14

Using Differentials to Differentiate Trigonometric and Exponential Functions  

ERIC Educational Resources Information Center

Starting from geometric definitions, we show how differentials can be used to differentiate trigonometric and exponential functions without limits, numerical estimates, solutions of differential equations, or integration.

Dray, Tevian

2013-01-01

15

Accessory olfactory learning  

Microsoft Academic Search

Learning in the accessory olfactory bulb is modelled mathematically by means of a set of coupled oscillator equations to describe the ongoing activity. The modification of this activity by experience is shown to lead to a change of the transfer function of the AOB as an input-output device. This leads both to a test of the model and a means

J. G. Taylor; E. B. Keverne

1991-01-01

16

Functional Recovery Following an End to Side Neurorrhaphy of the Accessory Nerve to the Suprascapular Nerve: Case Report  

PubMed Central

The use of end-to-side neurrorhaphy remains a controversial topic in peripheral nerve surgery. The authors report the long-term functional outcome following a modified end-to-side motor reinnervation using the spinal accessory to innervate the suprascapular nerve following a C5 to C6 avulsion injury. Additionally, functional outcomes of an end-to-end neurotization of the triceps branch to the axillary nerve and double fascicular transfer of the ulnar and medial nerve to the biceps and brachialis are presented. Excellent functional recoveries are found in respect to shoulder abduction and flexion and elbow flexion. Electronic supplementary material The online version of this article (doi:10.1007/s11552-009-9242-3) contains supplementary material, which is available to authorized users.

Ray, Wilson Z.; Kasukurthi, Rahul; Yee, Andrew

2009-01-01

17

Accessory parotid gland tumors  

PubMed Central

Tumors of accessory parotid gland are considered in the differential diagnosis of a mid cheek mass. Parotidectomy is the procedure of choice. All pathological types of parotid main gland tumors occur in the accessory parotid gland also. Presenting as a mid cheek or infrazygomatic mass, the tumors of this accessory parotid gland are notorious for recurrences, if adequate margins are not achieved. We describe two such cases of such a tumor. 40-year-old male with a slowly progressive mid cheek mass was operated by a mid cheek incision. Histopathology of the tumor was pleomorphic adenoma. Facial nerve paresis recovered complelety in 6 months. A 52-year-old female with progressive mid cheek mass who underwent parotidectomy and neck dissection by a modified Blair's incision was diagnosed with extranodal marginal zone lymphoma with focal transformation to a diffuse large B-cell lymphoma. Chemotherapy with CHOP regime was initiated. There was no recurrence at 6 months of follow-up. Lymphoma of accessory parotid gland is a very rare tumor. Standard parotidectomy incision is advocated to prevent damage to facial nerve branches.

Ramachar, Sreevathsa M.; Huliyappa, Harsha A.

2012-01-01

18

Accessory olfactory bulb function is modulated by input from the main olfactory epithelium.  

PubMed

Although it is now established that sensory neurons in both the main olfactory epithelium and the vomeronasal organ may be activated by both general and pheromonal odorants, it remains unclear what initiates sampling by the vomeronasal organ. Anterograde transport of wheat germ agglutinin-horseradish peroxidase was used to determine that adequate intranasal syringing with zinc sulfate interrupted all inputs to the main olfactory bulb but left intact those to the accessory olfactory bulb. Adult male treated mice were frankly anosmic when tested with pheromonal and non-pheromonal odors and failed to engage in aggressive behavior. Treated juvenile females failed to show puberty acceleration subsequent to exposure to bedding from adult males. Activation of the immediate early gene c-Fos and electrovomeronasogram recording confirmed the integrity of the vomeronasal system in zinc sulfate-treated mice. These results support the hypothesis that odor detection by the main olfactory epithelium is required to initiate sampling by the vomeronasal system. PMID:20377623

Slotnick, Burton; Restrepo, Diego; Schellinck, Heather; Archbold, Georgina; Price, Stephen; Lin, Weihong

2010-03-01

19

Accessory Olfactory Bulb Function is Modulated by Input from the Main Olfactory Epithelium  

PubMed Central

While it is now established that sensory neurons in both the main olfactory epithelium and the vomeronasal organ may be activated by both general and pheromonal odorants, it remains unclear what initiates sampling by the VNO. Anterograde transport of wheat germ agglutinin-horseradish peroxidase was used to determine that adequate intranasal syringing with zinc sulfate interrupted all inputs to the main olfactory bulb but left intact those to the accessory olfactory bulb. Adult male treated mice were frankly anosmic when tested with pheromonal and non-pheromonal odors and failed to engage in aggressive behavior. Treated juvenile females failed to show puberty acceleration subsequent to exposure to bedding from adult males. Activation of the immediate early gene c-Fos and electro-vomeronasogram recording confirmed the integrity of the vomeronasal system in zinc sulfate treated mice. These results support the hypothesis that odor detection by the main olfactory epithelium is required to initiate sampling by the vomeronasal system.

Slotnick, Burton; Restrepo, Diego; Schellinck, Heather; Archbold, Georgina; Price, Stephen; Lin, Weihong

2013-01-01

20

Melanocortin receptors and their accessory proteins.  

PubMed

The melanocortin receptor family consists of 5 members which belong to the GPCR superfamily. Their specific ligands, the melanocortins are peptide hormones which are formed by the proteolytic cleavage of the proopiomelanocortin (POMC) protein. It is now recognised that certain GPCRs require accessory proteins for their function. Like these GPCRs the melanocortin receptor family is also known to be associated with accessory proteins that regulate their function. In this review we will summarise the accessory proteins involved in the function of the 5 melanocortin receptors and in particular focus on the melanocortin 2 receptor accessory protein (MRAP) which is crucial for the function of the MC2R. PMID:20654690

Cooray, Sadani N; Clark, Adrian J L

2011-01-15

21

Fluorescence resonance energy transfer between polyphenolic compounds and riboflavin indicates a possible accessory photoreceptor function for some polyphenolic compounds.  

PubMed

The photoreceptive extreme tip of the wheat coleoptile exhibits intense green-yellow fluorescence under UV light, suggesting the presence of UV-absorbing materials. Fluorescence spectra of the intact coleoptile tip and tip homogenate showed the presence of the known photoreceptor pigments flavin and carotene, and a preponderance of phenolic compounds. Absorption spectra and fluorescence spectra of various phenolic compounds showed close overlap with the absorption and fluorescence spectra of the wheat coleoptile tip homogenate. Fluorescence spectra of several phenolic compounds showed close overlap with the absorption bands of flavin, carotene and pterine, suggesting possible energy transduction from phenols to these photoreceptors. Excitation of gentisic acid and ferulic acid with 340 nm light in the presence of flavin showed enhancement of flavin fluorescence in a concentration- and viscosity-dependent fashion, indicating fluorescence resonance energy transfer between them and riboflavin. Furthermore, several phenolic compounds tested generated superoxide anion on excitation at 340 nm, suggesting that superoxide-dependent signal cascades could operate in a polyphenol-mediated pathway. Phenolic compounds thus may act as accessory photoreceptors bringing about excitation energy transfer to the reactive photoreceptor molecules, or they may take over the function of the normal photoreceptor in genetic mutations lacking the system, or both processes may occur. The responses of plants to UV-B and UV-A light in mutants may be explained in terms of various phenolics acting as energy transducers in photoreceptor functioning. PMID:16842022

Chandrakuntal, Kumar; Thomas, Neena Mary; Kumar, Pradeep G; Laloraya, Malini; Laloraya, Manmohan M

2006-01-01

22

The UreEF Fusion Protein Provides a Soluble and Functional Form of the UreF Urease Accessory Protein  

Microsoft Academic Search

Four accessory proteins (UreD, UreE, UreF, and UreG) are typically required to form the nickel-containing active site in the urease apoprotein (UreABC). Among the accessory proteins, UreD and UreF have been elusive targets for biochemical and structural characterization because they are not overproduced as soluble proteins. Using the best-studied urease system, in which the Klebsiella aerogenes genes are expressed in

Jong Kyong Kim; Scott B. Mulrooney; Robert P. Hausinger

2006-01-01

23

Surgical and conservative methods for restoring impaired motor function - facial nerve, spinal accessory nerve, hypoglossal nerve (not including vagal nerve or swallowing)  

PubMed Central

The present review gives a survey of rehabilitative measures for disorders of the motor function of the mimetic muscles (facial nerve), and muscles innervated by the spinal accessory and hypoglossal nerves. The dysfunction can present either as paralysis or hyperkinesis (hyperkinesia). Conservative and surgical treatment options aimed at restoring normal motor function and correcting the movement disorders are described. Static reanimation techniques are not dealt with. The final section describes the use of botulinum toxin in the therapy of dysphagia.

Laskawi, R.; Rohrbach, S.

2005-01-01

24

Function and composition of male accessory gland secretions in Anopheles gambiae: a comparison with other insect vectors of infectious diseases  

PubMed Central

Human malaria, a major public health burden in tropical and subtropical countries, is transmitted exclusively by the bite of a female Anopheles mosquito. Malaria control strategies aimed at inducing sexual sterility in natural vector populations are an attractive alternative to the use of insecticides. However, despite their importance as disease vectors, limited information is available on the molecular mechanisms regulating fertility in Anopheles mosquitoes. In the major malaria vector, An. gambiae, the full complement of sperm and seminal fluid required for a female’s lifelong egg production is obtained from a single mating event. This single mating has important consequences for the physiology and behavior of An. gambiae females: in particular, they become refractory to further insemination, and they start laying eggs. In other insects including Drosophila, similar post-copulatory changes are induced by seminal proteins secreted by the male accessory glands and transferred to the female during mating. In this review, we analyze the current state of knowledge on the function and characterization of male seminal proteins in An. gambiae, and provide a comparative assessment of the role of these male reproductive factors in other mosquito vectors of human disease in which female post-copulatory behavior has been studied. Knowledge of the factors and mechanisms regulating fertility in An. gambiae and other vectors can help the design of novel control strategies to fight the spread of disease.

Baldini, Francesco; Gabrieli, Paolo; Rogers, David W.; Catteruccia, Flaminia

2012-01-01

25

Stretch-induced spinal accessory nerve palsy.  

PubMed

Left spinal accessory nerve palsy occurred in a young man when he quickly turned his head to the right while his shoulders were pulled down by heavy hand-held objects. Electrophysiologic studies demonstrated partial axonotmesis of the spinal accessory nerve branches innervating the sternocleidomastoid and upper and middle trapezius and complete axonotmesis of spinal accessory branches to the lower trapezius. There was a separate, although functionally minor, cervical plexus innervation of the lower trapezius. PMID:3343990

Logigian, E L; McInnes, J M; Berger, A R; Busis, N A; Lehrich, J R; Shahani, B T

1988-02-01

26

Functional development of sex accessory organs of the male rat. Use of oestradiol benzoate to identify the neonatal period as critical for development of normal protein-synthetic and secretory capabilities.  

PubMed Central

Functional development of the sex accessory tissues was studied in the male rat. Three potentially crucial developmental periods (neonatal, prepubertal and pubertal) were examined, and then the functional integrity of the accessory tissues was investigated in the adult, when the animals would have been expected to display normal function. Four accessory tissues (the seminal vesicles, ventral prostate and caput and cauda epididymides) were used because of their different embryological origins and responses to androgens in the adult. Synthesis and secretion of previously characterized tissue-specific androgen-dependent proteins were taken as indicators of normal function. Development was perturbed by using oestradiol benzoate, since this was known to affect gross development of the seminal vesicles and ventral prostate when given to neonatal rats. Treatment during the first 5 days after birth severely restricted development of the seminal vesicles and ventral prostate. Protein secreted by the former was only 1% of the normal amount, and in many cases several major secretory proteins were essentially missing. Prostatic protein secretion was less than 20% of normal, but all the major proteins were detectable. In both tissues overall protein synthesis per cell was quantitatively normal, but the proportion devoted to specific major secretory proteins was markedly depressed, i.e. the response is differential. In contrast, treatment during the prepubertal period was without noticeable effects. Development of the seminal vesicles and prostate was somewhat inhibited by treatment at puberty, but these changes were minor compared with those after neonatal exposure to oestradiol benzoate. No effects on epididymal protein synthesis or secretory proteins were observed, and epididymal weight and DNA content were only moderately decreased regardless of when oestradiol benzoate was administered during sexual maturation. Hence the neonatal period is not so critical for epididymal development. The substantial changes elicited by oestrogen treatment during neonatal life in seminal-vesicle and prostatic protein synthesis and secretion were compared with those evoked in sexually mature males by either oestrogen treatment or castration. Both these latter treatments resulted in a general decrease in seminal-vesicle protein synthesis and secretion, but the marked differential effects on major proteins after neonatal exposure were absent. Castration did, however, evoke a differential prostatic response, but this was not seen after oestrogen treatment of adults. Images Fig. 1. Fig. 2.

Higgins, S J; Brooks, D E; Fuller, F M; Jackson, P J; Smith, S E

1981-01-01

27

Functional and morphological characterization of 4F7+ spleen accessory dendritic cells.  

PubMed

Recently we have reported on the production of the mAb 4F7. This recognizes a molecule that is upregulated on dermal and epidermal dendritic cells after application of contact allergen. Furthermore, this antibody detects an antigen on spleen and lymph node dendritic cells. In this study, we characterize 4F7+ spleen dendritic cells and show that the mAb recognizes in situ few labeled cells in the white pulp of the spleen and approximately 1% of spleen single cell suspensions as evidenced by cell enrichment, immunoperoxidase staining and FACS analysis. Immunohistological characterization of the cells with mAbs revealed the expression of class II, class I MHC antigens, 33D1, CD11c, ICAM-1, and CD45 molecules. After enrichment and cultivation for approximately 3 days, these cells showed no adherent properties. The capacity of 4F7+ spleen dendritic cells to activate allogeneic T cells in the primary mixed lymphocyte reaction was similar to freshly isolated Ia+ Langerhans cells. With regard to the induction of a proliferative response of CD4+ naive T cells that were incubated with concanavalin A or anti-CD3 mAb, 4F7+ spleen dendritic cells were two to three times more potent than spleen microphages and B cells. Furthermore, 4F7+ cells efficiently stimulated the antigen dependent proliferation of a T helper cell line. The mAb 4F7 will be useful for the purification of dendritic cells and for functional and molecular biological studies. PMID:8347556

Mohamadzadeh, M; Jonuleit, H; Kolde, G; Pavlidou, A; Schmitt, E; Knop, J

1993-06-01

28

Functional analysis of the accessory protein TapA in Bacillus subtilis amyloid fiber assembly.  

PubMed

Bacillus subtilis biofilm formation relies on the assembly of a fibrous scaffold formed by the protein TasA. TasA polymerizes into highly stable fibers with biochemical and morphological features of functional amyloids. Previously, we showed that assembly of TasA fibers requires the auxiliary protein TapA. In this study, we investigated the roles of TapA sequences from the C-terminal and N-terminal ends and TapA cysteine residues in its ability to promote the assembly of TasA amyloid-like fibers. We found that the cysteine residues are not essential for the formation of TasA fibers, as their replacement by alanine residues resulted in only minor defects in biofilm formation. Mutating sequences in the C-terminal half had no effect on biofilm formation. However, we identified a sequence of 8 amino acids in the N terminus that is key for TasA fiber formation. Strains expressing TapA lacking these 8 residues were completely defective in biofilm formation. In addition, this TapA mutant protein exhibited a dominant negative effect on TasA fiber formation. Even in the presence of wild-type TapA, the mutant protein inhibited fiber assembly in vitro and delayed biofilm formation in vivo. We propose that this 8-residue sequence is crucial for the formation of amyloid-like fibers on the cell surface, perhaps by mediating the interaction between TapA or TapA and TasA molecules. PMID:24488317

Romero, Diego; Vlamakis, Hera; Losick, Richard; Kolter, Roberto

2014-04-01

29

Detecting Differential Person Functioning in Emotional Intelligence  

ERIC Educational Resources Information Center

Differential Item Functioning (DIF) is a widely used term in test development literature. It is very important to analyze test's data for DIF because It is a serious threat to validity. If the same data matrix was transposed, similar analysis can be carried for Differential Person Functioning (DPF). The purpose of this paper is to introduce and…

Alsmadi, Yahia M.; Alsmadi, Abdalla A.

2009-01-01

30

Identifying Possible Sources of Differential Functioning Using Differential Bundle Functioning with Polytomously Scored Data  

ERIC Educational Resources Information Center

Oshima, Raju, Flowers, and Slinde (1998) described procedures for identifying sources of differential functioning for dichotomous data using differential bundle functioning (DBF) derived from the differential functioning of items and test (DFIT) framework (Raju, van der Linden, & Fleer, 1995). The purpose of this study was to extend the procedures…

McCarty, F. A.; Oshima, T. C.; Raju, Nambury S.

2007-01-01

31

Fractional differentiability of nowhere differentiable functions and dimensions.  

PubMed

Weierstrass's everywhere continuous but nowhere differentiable function is shown to be locally continuously fractionally differentiable everywhere for all orders below the "critical order" 2-s and not so for orders between 2-s and 1, where s, 1function. This observation is consolidated in the general result showing a direct connection between local fractional differentiability and the box dimension/local Holder exponent. Levy index for one dimensional Levy flights is shown to be the critical order of its characteristic function. Local fractional derivatives of multifractal signals (non-random functions) are shown to provide the local Holder exponent. It is argued that Local fractional derivatives provide a powerful tool to analyze pointwise behavior of irregular signals. (c) 1996 American Institute of Physics. PMID:12780280

Kolwankar, Kiran M.; Gangal, Anil D.

1996-12-01

32

The melanocortin 2 receptor accessory protein exists as a homodimer and is essential for the function of the melanocortin 2 receptor in the mouse y1 cell line.  

PubMed

The ACTH receptor [melanocortin 2 receptor (MC2R)] gene produces a functional receptor only when transfected into cells of adrenocortical origin, implying that it may require an adrenal-specific accessory factor. Recently we showed that the MC2R accessory protein (MRAP) is essential for the cell surface expression of the MC2R in such models. Using RNA interference (RNAi) technology, we have further explored the action of MRAP in the functioning of the MC2R in Y1 mouse adrenocortical cells that endogenously express MRAP and MC2R. We created stable cell lines expressing mouse MRAP short hairpin RNA (shRNAs) by transfecting cells with an expression vector containing the MRAP small interfering RNA sequence. The knockdown of MRAP resulted in a reduction in MC2R signaling. The overexpression of a mouse MRAP-Flag construct did not restore the expression of MRAP due to its degradation by the mouse shRNAs. The introduction of human MRAP that is resistant to silencing by mouse MRAP shRNAs resulted in the rescue of the MC2R signaling. MRAP migrates on SDS-PAGE with markedly lower mobility than predicted for a 14.1-kDa protein. Coimmunoprecipitation and mass spectroscopy suggests that MRAP exists as a homodimer that is resistant to dissociation by sodium dodecyl sulfate and reducing agents. PMID:18162519

Cooray, Sadani N; Almiro Do Vale, Isabel; Leung, Kit-Yi; Webb, Tom R; Chapple, J Paul; Egertová, Michaela; Cheetham, Michael E; Elphick, Maurice R; Clark, Adrian J L

2008-04-01

33

Multiple Functional Roles of the Accessory I-Domain of Bacteriophage P22 Coat Protein Revealed by NMR Structure and CryoEM Modeling.  

PubMed

Some capsid proteins built on the ubiquitous HK97-fold have accessory domains imparting specific functions. Bacteriophage P22 coat protein has a unique insertion domain (I-domain). Two prior I-domain models from subnanometer cryoelectron microscopy (cryoEM) reconstructions differed substantially. Therefore, the I-domain's nuclear magnetic resonance structure was determined and also used to improve cryoEM models of coat protein. The I-domain has an antiparallel six-stranded ?-barrel fold, not previously observed in HK97-fold accessory domains. The D-loop, which is dynamic in the isolated I-domain and intact monomeric coat protein, forms stabilizing salt bridges between adjacent capsomers in procapsids. The S-loop is important for capsid size determination, likely through intrasubunit interactions. Ten of 18 coat protein temperature-sensitive-folding substitutions are in the I-domain, indicating its importance in folding and stability. Several are found on a positively charged face of the ?-barrel that anchors the I-domain to a negatively charged surface of the coat protein HK97-core. PMID:24836025

Rizzo, Alessandro A; Suhanovsky, Margaret M; Baker, Matthew L; Fraser, LaTasha C R; Jones, Lisa M; Rempel, Don L; Gross, Michael L; Chiu, Wah; Alexandrescu, Andrei T; Teschke, Carolyn M

2014-06-10

34

Screening Test Items for Differential Item Functioning  

ERIC Educational Resources Information Center

A method for medical screening is adapted to differential item functioning (DIF). Its essential elements are explicit declarations of the level of DIF that is acceptable and of the loss function that quantifies the consequences of the two kinds of inappropriate classification of an item. Instead of a single level and a single function, sets of…

Longford, Nicholas T.

2014-01-01

35

A class of neutral functional differential equations.  

NASA Technical Reports Server (NTRS)

Formulation and study of the initial value problem for neutral functional differential equations. The existence, uniqueness, and continuation of solutions to this problem are investigated, and an analysis is made of the dependence of the solutions on the initial conditions and parameters, resulting in the derivation of a continuous dependence theorem in which the fundamental mathematical principles underlying the continuous dependence problem for a very general system of nonlinear neutral functional differential equations are separated out.

Melvin, W. R.

1972-01-01

36

Examining the Relationship between Differential Item Functioning and Differential Test Functioning  

ERIC Educational Resources Information Center

The present study utilized both the IRT-LR (item response theory likelihood ratio) and a series of CFA (confirmatory factor analysis) multi-sample analyses to systematically examine the relationships between DIF (differential item functioning) and DTF (differential test functioning) with a random sample of 15 000 Korean examinees. Specifically,…

Pae, Tae-Il; Park, Gi-Pyo

2006-01-01

37

Detecting Differential Item Functioning and Differential Step Functioning due to Differences that "Should" Matter  

ERIC Educational Resources Information Center

This study illustrates the use of differential item functioning (DIF) and differential step functioning (DSF) analyses to detect differences in item difficulty that are related to experiences of examinees, such as their teachers' instructional practices, that are relevant to the knowledge, skill, or ability the test is intended to measure. This…

Miller, Tess; Chahine, Saad; Childs, Ruth A.

2010-01-01

38

14 CFR 23.1163 - Powerplant accessories.  

Code of Federal Regulations, 2012 CFR

...TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Powerplant Powerplant Controls and Accessories § 23.1163 Powerplant accessories. (a) Each engine mounted accessory...

2014-01-01

39

14 CFR 25.1163 - Powerplant accessories.  

Code of Federal Regulations, 2011 CFR

...ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Powerplant Powerplant Controls and Accessories § 25.1163 Powerplant accessories. (a) Each engine mounted accessory...

2014-01-01

40

Real and Artificial Differential Item Functioning  

ERIC Educational Resources Information Center

The literature in modern test theory on procedures for identifying items with differential item functioning (DIF) among two groups of persons includes the Mantel-Haenszel (MH) procedure. Generally, it is not recognized explicitly that if there is real DIF in some items which favor one group, then as an artifact of this procedure, artificial DIF…

Andrich, David; Hagquist, Curt

2012-01-01

41

Ramsay-Curve Differential Item Functioning  

ERIC Educational Resources Information Center

Differential item functioning (DIF) occurs when an item on a test, questionnaire, or interview has different measurement properties for one group of people versus another, irrespective of true group-mean differences on the constructs being measured. This article is focused on item response theory based likelihood ratio testing for DIF (IRT-LR or…

Woods, Carol M.

2011-01-01

42

Differential Item Functioning Analysis Using Rasch Item Information Functions  

ERIC Educational Resources Information Center

Differential item functioning (DIF) analysis is a statistical technique used for ensuring the equity and fairness of educational assessments. This study formulates a new DIF analysis method using the information similarity index (ISI). ISI compares item information functions when data fits the Rasch model. Through simulations and an international…

Wyse, Adam E.; Mapuranga, Raymond

2009-01-01

43

Accessory oral cavity.  

PubMed

This is a rare case report of a patient around 11 years with the complaint of extra mouth who reported to the hospital for removal of that extra mouth. On examination there was accessory oral cavity with small upper and lower lips, seven teeth and saliva was drooling out. Under general anesthesia crevicular incision from 32 to 43 was put and labial gingiva with alveolar mucosa was reflected completely and bone exposed to lower border of mandible. There were seven teeth resembling lower permanent anterior teeth in the accessory mouth, which was excised with the accessory lips. 41 extracted and osteotomy carried out extending the incision from the extracted site and osteotomy carried out. Dermoid cyst both below and above the mylohyoid muscle and rudimentary tongue found and excised and the specimen sent for histopathological examination. The wound was closed and uneventful healing noted to the satisfaction of the patient. This is a rare and interesting case which has been documented. PMID:23833508

Gnaneswaran, Manica Ramamoorthy; Varadarajan, Usha; Srinivasan, Ramesh; Kamatchi, Sangeetha

2012-07-01

44

The melanocortin receptors and their accessory proteins.  

PubMed

The five melanocortin receptors (MCRs) named MC1R-MC5R have diverse physiological roles encompassing pigmentation, steroidogenesis, energy homeostasis and feeding behavior as well as exocrine function. Since their identification almost 20 years ago much has been learnt about these receptors. As well as interacting with their endogenous ligands the melanocortin peptides, there is now a growing list of important peptides that can modulate the way these receptors signal, acting as agonists, antagonists, and inverse agonists. The discovery of melanocortin 2 receptor accessory proteins as a novel accessory factor to the MCRs provides further insight into the regulation of these important G protein-coupled receptor. PMID:23404466

Ramachandrappa, Shwetha; Gorrigan, Rebecca J; Clark, Adrian J L; Chan, Li F

2013-01-01

45

The effect of accessory minerals on the redistribution of lead isotopes during crustal anatexis: A model  

SciTech Connect

The initial Pb isotopic composition of anatectic granites is modelled as a mixture of Pb derived from major minerals that have characteristically low {sup 238}U/{sup 204}Pb and {sup 232}Th/{sup 204}Pb ratios, with Pb contributed from dissolved accessory minerals with characteristically high {sup 238}U/{sup 204}Pb and {sup 232}Th/{sup 204}Pb ratios. The initial Pb isotopic composition of anatectic granites is a function of (a) the age, type, modal distribution, and heterogeneity in the initial U and Th content of the accessory minerals, (b) variation in melt composition and temperature during anatexis, (c) the fraction of the source melted, and (d) the extent to which the melt was homogenized prior to crystallization. The differential behavior of accessory minerals during anatexis can explain the common yet enigmatic decoupling of the Pb isotopes from other chemical and isotopic systems in granite rocks. Granitic plutons derived by anatexis of the same source material are not required to have the same initial Pb isotopic composition. Low temperature, peraluminous granites are more likely to exhibit homogeneous initial Pb isotopic compositions dominated by the Pb contained within the major mineral assemblage of the source material. In contrast, the initial Pb isotopic composition of higher temperature, metaluminous or peralkaline anatectic granites is more likely to be heterogeneous, unless the melts are homogenized during emplacement, and will record a larger fraction of the radiogenic Pb component contained in the accessory mineral assemblage of the source material.

Hogan, J.P.; Sinha, A.K. (Virginia Polytechnic Institute and State Univ., Blacksburg (USA))

1991-01-01

46

Glu227-->Lys substitution in the acidic loop of major histocompatibility complex class I alpha 3 domain distinguishes low avidity CD8 coreceptor and avidity-enhanced CD8 accessory functions  

PubMed Central

Cytotoxic T lymphocyte (CTL) activation requires specific T cell receptor (TCR)-class I major histocompatibility complex (MHC) antigen complex interactions as well as the participation of coreceptor or accessory molecules on the surface of CTL. CD8 can serve as a coreceptor in that it binds to the same MHC class I molecules as the TCR to facilitate efficient TCR signaling. In addition, CD8 can be "activated" by TCR stimulation to bind to class I molecules with high avidity, including class I not recognized by the TCR as antigenic complexes (non-antigen [Ag] class I), to augment CTL responses and thus serve an accessory molecule function. A Glu/Asp227-->Lys substitution in the class I alpha 3 domain acidic loop abrogates lysis of target cells expressing these mutant molecules by alloreactive CD8-dependent CTL. Lack of response is attributed to the destruction of the CD8 binding site in the alpha 3 domain which is likely to disrupt CD8 coreceptor function. The relative importance of the class I alpha 3 domain acidic loop Glu227 in coreceptor as opposed to accessory functions of CD8 is unclear. To address this issue, we examined CTL adhesion and degranulation in response to immobilized class I-peptide complexes formed in vitro from antigenic peptides and purified class I molecules containing wild-type or Glu227-->Lys substituted alpha 3 domains. The alpha 3 domain mutant class I-peptide complexes were bound by CTL and triggered degranulation, however to much lower levels than wild-type class I-peptide complexes. In further experiments, it is directly demonstrated that the alpha 3 domain mutant class I molecules, which lack the Glu227 CD8 binding site, still serve as TCR-activated, avidity-enhanced CD8 accessory ligands. However, mutant class I peptide Ag complexes failed to effectively serve as CD8 coreceptor ligands to initiate TCR-dependent signals required to induce avidity-enhanced CD8 binding to coimmobilized non-Ag class I molecules. Thus the Glu227-- >Lys mutation effectively distinguishes CD8 coreceptor and avidity- enhanced CD8 accessory functions.

1996-01-01

47

Distinguishing Differential Testlet Functioning from Differential Bundle Functioning Using the Multilevel Measurement Model  

ERIC Educational Resources Information Center

This study extends the multilevel measurement model to handle testlet-based dependencies. A flexible two-level testlet response model (the MMMT-2 model) for dichotomous items is introduced that permits assessment of differential testlet functioning (DTLF). A distinction is made between this study's conceptualization of DTLF and that of…

Beretvas, S. Natasha; Walker, Cindy M.

2012-01-01

48

Chebyshev pseudospectral method and waveform relaxation for differential and differential–functional parabolic equations  

Microsoft Academic Search

The waveform relaxation technique for linear parabolic differential and differential–functional equations is studied. We use the second order finite difference method and the Chebyshev pseudospectral method for spatial discretization and apply a Gauss–Seidel waveform relaxation scheme to the resulting systems of ordinary differential and differential–functional equations. Waveform relaxation error bounds are presented for the two semi-discretization schemes in both functional

Barbara Zubik-Kowal

2000-01-01

49

14 CFR 25.1167 - Accessory gearboxes.  

Code of Federal Regulations, 2011 CFR

...TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Powerplant Powerplant Controls and Accessories § 25.1167 Accessory gearboxes. For airplanes equipped with an accessory gearbox that is not certificated as...

2014-01-01

50

A new kind of auxiliary heart in insects: functional morphology and neuronal control of the accessory pulsatile organs of the cricket ovipositor  

PubMed Central

Introduction In insects, the pumping of the dorsal heart causes circulation of hemolymph throughout the central body cavity, but not within the interior of long body appendages. Hemolymph exchange in these dead-end structures is accomplished by special flow-guiding structures and/or autonomous pulsatile organs (“auxiliary hearts”). In this paper accessory pulsatile organs for an insect ovipositor are described for the first time. We studied these organs in females of the cricket Acheta domesticus by analyzing their functional morphology, neuroanatomy and physiological control. Results The lumen of the four long ovipositor valves is subdivided by longitudinal septa of connective tissue into efferent and afferent hemolymph sinuses which are confluent distally. The countercurrent flow in these sinuses is effected by pulsatile organs which are located at the bases of the ovipositor valves. Each of the four organs consists of a pumping chamber which is compressed by rhythmically contracting muscles. The morphology of the paired organs is laterally mirrored, and there are differences in some details between the dorsal and ventral organs. The compression of the pumping chambers of each valve pair occurs with a left-right alternating rhythm with a frequency of 0.2 to 0.5 Hz and is synchronized between the dorsal and ventral organs. The more anteriorly located genital chamber shows rhythmical lateral movements simultaneous to those of the ovipositor pulsatile organs and probably supports the hemolymph exchange in the abdominal apex region. The left-right alternating rhythm is produced by a central pattern generator located in the terminal ganglion. It requires no sensory feedback for its output since it persists in the completely isolated ganglion. Rhythm-modulating and rhythm-resetting interneurons are identified in the terminal ganglion. Conclusion The circulatory organs of the cricket ovipositor have a unique functional morphology. The pumping apparatus at the base of each ovipositor valve operates like a bellow. It forces hemolymph via sinuses delimited by thin septa of connective tissue in a countercurrent flow through the valve lumen. The pumping activity is based on neurogenic control by a central pattern generator in the terminal ganglion.

2014-01-01

51

Differential optical transfer function wavefront sensing  

NASA Astrophysics Data System (ADS)

An image-based technique for measuring the complex field in the pupil of an imaging system is presented. Two point source images, one with a small modification introduced in the pupil, are combined using a simple and non-iterative algorithm. The non-interferometric method is based on the change in the optical transfer function (OTF) giving a differential optical transfer function (dOTF). The dOTF includes two images of the complex pupil field, conjugated and reflected about the position of the pupil modification, leaving an overlap that obscures some of the pupil. The overlap can be minimized by introducing the modification near the edge of the pupil. The overlap region can be eliminated altogether by using a second modification and a third point source image. The pupil field is convolved by the change in the pupil field, so smaller modification areas are preferred. When using non-monochromatic light, the dOTF incurs a proportional radial blurring determined by the fractional bandwidth. We include some simple demonstration experiments, including using a pupil blockage and moving a single deformable mirror actuator as the pupil modification. In each case, the complex wavefront is easily recovered, even when the pupil mask is unknown and the wavefront aberrations are large.

Codona, Johanan L.

2013-09-01

52

Evidence of Differential HLA Class I-Mediated Viral Evolution in Functional and Accessory\\/Regulatory Genes of HIV1  

Microsoft Academic Search

Despite the formidable mutational capacity and sequence diversity of HIV-1, evidence suggests that viral evolution in response to specific selective pressures follows generally predictable mutational pathways. Population-based analyses of clinically derived HIV sequences may be used to identify immune escape mutations in viral genes; however, prior attempts to identify such mutations have been complicated by the inability to discriminate active

Zabrina L Brumme; Chanson J Brumme; David Heckerman; Bette T Korber; Marcus Daniels; Jonathan Carlson; Carl Kadie; Tanmoy Bhattacharya; Celia Chui; James Szinger; Theresa Mo; Robert S Hogg; Julio S. G Montaner; Nicole Frahm; Christian Brander; Bruce D Walker; P. Richard Harrigan

2007-01-01

53

Thermomechanical milling of accessory lithics in volcanic conduits  

NASA Astrophysics Data System (ADS)

Accessory lithic clasts recovered from pyroclastic deposits commonly result from the failure of conduit wall rocks, and represent an underutilized resource for constraining conduit processes during explosive volcanic eruptions. The morphological features of lithic clasts provide distinctive 'textural fingerprints' of processes that have reshaped them during transport in the conduit. Here, we present the first study focused on accessory lithic clast morphology and show how the shapes and surfaces of these accessory pyroclasts can inform on conduit processes. We use two main types of accessory lithic clasts from pyroclastic fallout deposits of the 2360 B.P. subplinian eruption of Mount Meager, British Columbia, as a case study: (i) rough and subangular dacite clasts, and (ii) variably rounded and smoothed monzogranite clasts. The quantitative morphological data collected on these lithics include: mass, volume, density, 2-D image analysis of convexity (C), and 3-D laser scans for sphericity (?) and smoothness (S). Shaping and comminution (i.e. milling) of clasts within the conduit are ascribed to three processes: (1) disruptive fragmentation due to high-energy impacts between clasts or between clasts and conduit walls, (2) ash-blasting of clasts suspended within the volcanic flux, and (3) thermal effects. We use a simplified conduit eruption model to predict ash-blasting velocities and lithic residence times as a function of clast size and source depth, thereby constraining the lithic milling processes. The extent of shape and surface modification (i.e. rounding and honing) is directly proportional to clast residence times within the conduit prior to evacuation. We postulate that the shallow-seated dacite clasts remain subangular and rough due to short (<2 min) residence times, whereas monzogranite clasts are much more rounded and smoothed due to deeper source depths and consequently longer residence times (up to ˜1 h). Larger monzogranite clasts are smoother than smaller clasts due to longer residence times and to greater differential velocities within the ash-laden jet. Lastly, our model residence times and mass loss estimates for rounded clasts are used to estimate minimum attrition rates due to volcanic ash-blasting within the conduit (e.g., 12 cm3?s-1 for 25 cm clasts, sourced at 2500 m depth).

Campbell, Michelle E.; Russell, James K.; Porritt, Lucy A.

2013-09-01

54

Adenosine receptors in regulation of dendritic cell differentiation and function  

Microsoft Academic Search

Differentiation of functional dendritic cells (DCs) critically depends on the microenvi- ronment. DCs differentiate in hypoxic tu- mor sites and inflamed or damaged tis- sue. Because local concentrations of adenosine reach high physiologically rel- evant levels in these conditions, we as- sessed the expression of adenosine re- ceptors and the effect of their activation on differentiation of human monocytes and

Sergey V. Novitskiy; Sergey Ryzhov; Rinat Zaynagetdinov; Anna E. Goldstein; Yuhui Huang; Oleg Y. Tikhomirov; Michael R. Blackburn; Italo Biaggioni; David P. Carbone; Igor Feoktistov; Mikhail M. Dikov

2008-01-01

55

Legendre-tau approximations for functional differential equations  

NASA Technical Reports Server (NTRS)

The numerical approximation of solutions to linear retarded functional differential equations are considered using the so-called Legendre-tau method. The functional differential equation is first reformulated as a partial differential equation with a nonlocal boundary condition involving time-differentiation. The approximate solution is then represented as a truncated Legendre series with time-varying coefficients which satisfy a certain system of ordinary differential equations. The method is very easy to code and yields very accurate approximations. Convergence is established, various numerical examples are presented, and comparison between the latter and cubic spline approximation is made.

Ito, K.; Teglas, R.

1986-01-01

56

Computations involving differential operators and their actions on functions  

NASA Technical Reports Server (NTRS)

The algorithms derived by Grossmann and Larson (1989) are further developed for rewriting expressions involving differential operators. The differential operators involved arise in the local analysis of nonlinear dynamical systems. These algorithms are extended in two different directions: the algorithms are generalized so that they apply to differential operators on groups and the data structures and algorithms are developed to compute symbolically the action of differential operators on functions. Both of these generalizations are needed for applications.

Crouch, Peter E.; Grossman, Robert; Larson, Richard

1991-01-01

57

Functional Biomaterials for Controlling Stem Cell Differentiation  

Microsoft Academic Search

\\u000a Differentiation of stem cells has shown to be strongly influenced through several cues provided by reciprocal interactions\\u000a with the extracellular microenvironment, consisting of soluble bioactive agents and the extracellular matrix. While the dynamic\\u000a extracellular matrix is difficult to mimic in its entirety, recent research has successfully mimicked individual matrix-centric\\u000a cues using synthetic polymeric systems to influence differentiation of stem cells

Ameya Phadke; Chien-Wen Chang; Shyni Varghese

58

Container Handling and Accessory Equipment.  

National Technical Information Service (NTIS)

This document describes a method for test and evaluation of handling and accessory equipment for oversized cargo containers. It discusses test planning, preparations for test, inspection, technical performance, beach mobility, logistics-over-the-shore, te...

1978-01-01

59

A functional and phenotypic study on immune accessory cells isolated from the thyroids of Wistar and autoimmune-prone BB-DP rats.  

PubMed

Dendritic cells (DCs) comprise a small population of cells in the normal thyroid. These excellent antigen-presenting cells (APCs) are thought to be involved in the initiation of thyroid autoimmune reactions. However it is not known whether the APCs involved in this process are indeed DCs, or thyrocytes. Our aims were as follows: (1) to isolate DCs from the thyroid of normal Wistar rats and BB-DP rats prior to the development of lymphocytic thyroiditis; (2) to determine the T-cell stimulatory capability of such isolated thyroid DCs and to compare this capability to that of BB-DP thyrocytes and splenic DCs; and (3) to investigate the phenotype of isolated thyroid DCs and to compare it to that of splenic DCs; and (4) to investigate the capability of such thyroid DCs to regulate thyrocyte growth and function, and to compare it to our earlier reports demonstrating such capability with splenic DCs. Leukokcytic cell fractions were isolated from the thyroids of BB-DP and control Wistar rats of 7-20 weeks of age. The isolation steps included gentle enzymatic tissue disruption, the collection of non-plastic adherent cells and density gradient centrifugation of these cells to yield a low and a high density non-adherent fraction. The low density cell (LDC) fraction was composed of 50-75% leukocytes in both strains. These leukocytes were almost exclusively ED1+ monocytes or MHC-class II+ DC. The high density cell (HDC) fractions of both strains were composed of about 70% MHC-class II-negative thyrocytes and 30% ED1+ monocytes. The thyroid LDCs of both strains had an APC capability in syngeneic(syn)-MLR comparable to that of splenic DCs. However, the HDCs were extremely poor in syngeneic T cell stimulation. There was a difference in composition between the Wistar and the BB-DP LDC fractions: The Wistar LDCs were composed of 30-35% ED1+ monocytes and 15-20% typical MHC-II+ DCs, while BB-DP LDC fractions contained more ED1+ monocytes (about 70%), but fewer DCs (5-10%). In comparison to splenic DCs, thyroid DCs had a low CD80 and CD86 expression in both strains (i.e., an 'immature' phenotype). The LDCs of both animal strains were shown to decrease both basal and TSH-stimulated thyrocyte proliferation and T(3)release by about half. This report shows that a cell fraction enriched for monocytes and DCs can be isolated from the thyroids of both Wistar and BB-DP rats. The cells in this fraction were as capable as splenic DCs to act as T cell stimulators in syn-MLR. Since the thyroid HDCs (predominantly thyrocytes) were very poor at such T cell stimulation, thyroid monocytes and DCs (and not thyrocytes) are the prime candidates to act as immune accessory cells in the initiation of thyroid autoimmunity in the rat. Wistar thyroid LDCs differed in phenotype from BB-DP LDCs. The latter contained a lower percentage of DCs and a higher percentage of their precursors, the monocytes. Interestingly, a defect in the transition of monocytes to DCs has been described in another animal model of autoimmune thyroiditis/insulitis (the NOD mouse), as well as in thyroiditis and diabetic patients. PMID:11090240

Simons, P J; Delemarre, F G; Drexhage, H A

2000-12-01

60

Melanocortin receptor accessory proteins in adrenal gland physiology and beyond.  

PubMed

The melanocortin receptor (MCR) family consists of five G-protein-coupled receptors (MC1R-MC5R) with diverse physiological roles. MC1R controls pigmentation, MC2R is a critical component of the hypothalamic-pituitary-adrenal axis, MC3R and MC4R have a vital role in energy homeostasis and MC5R is involved in exocrine function. The melanocortin receptor accessory protein (MRAP) and its paralogue MRAP2 are small single-pass transmembrane proteins that have been shown to regulate MCR expression and function. In the adrenal gland, MRAP is an essential accessory factor for the functional expression of the MC2R/ACTH receptor. The importance of MRAP in adrenal gland physiology is demonstrated by the clinical condition familial glucocorticoid deficiency, where inactivating MRAP mutations account for ?20% of cases. MRAP is highly expressed in both the zona fasciculata and the undifferentiated zone. Expression in the undifferentiated zone suggests that MRAP could also be important in adrenal cell differentiation and/or maintenance. In contrast, the role of adrenal MRAP2, which is highly expressed in the foetal gland, is unclear. The expression of MRAPs outside the adrenal gland is suggestive of a wider physiological purpose, beyond MC2R-mediated adrenal steroidogenesis. In vitro, MRAPs have been shown to reduce surface expression and signalling of all the other MCRs (MC1,3,4,5R). MRAP2 is predominantly expressed in the hypothalamus, a site that also expresses a high level of MC3R and MC4R. This raises the intriguing possibility of a CNS role for the MRAPs. PMID:23418361

Novoselova, T V; Jackson, D; Campbell, D C; Clark, A J L; Chan, L F

2013-04-01

61

Crystallization of accessory phases in magmas by local saturation adjacent to phenocrysts  

USGS Publications Warehouse

Accessory minerals commonly occur attached to or included in the major crystalline phases of felsic and some intermediate igneous rocks. Apatite is particularly common as inclusions, but Fe-Ti oxides, pyrrhotite, zircon, monazite, chevkinite and xenotime are also known from silicic rocks. Accessories may nucleate near the host crystal/ liquid interface as a result of local saturation owing to formation of a differentiated chemical boundary layer in which accessory mineral solubility would be lower than in the surrounding liquid. Differentiation of this boundary layer would be greatest adjacent to ferromagnesian phenocrysts, especially Fe-Ti oxides; it is with oxides that accessories are most commonly associated in rocks. A boundary layer may develop if the crystal grows more rapidly than diffusion can transport incorporated and rejected elements to and from the phenocryst. Diffusion must dominate over convection as a mode of mass transfer near the advancing crystal/liquid interface in order for a boundary layer to exist. Accumulation of essential structural constituent elements of accessory minerals owing to their slow diffusion in evolved silicate melt also may force local saturation, but this is not a process that applies to all cases. Local saturation is an attractive mechanism for enhancing fractionation during crystallization differentiation. If accessory minerals attached to or included in phenocrysts formed because of local saturation, their host phenocrysts must have grown rapidly when accessories nucleated in comparison to lifetimes of magma reservoirs. Some inconsistencies remain in a local saturation origin for accessory phases that cannot be evaluated without additional information. ?? 1989.

Bacon, C. R.

1989-01-01

62

An Accessory Peroneocalcaneus Internus Muscle with MRI and US Correlation  

PubMed Central

The peroneocalcaneus internus (PCI) is a rare accessory muscle of the medial ankle with typical MRI anatomic features allowing differentiation from the more common accessory flexor digitorum longus muscle. To our knowledge, there have been no previously published sonographic images of the peroneocalcaneus internus. A PCI is typically an incidental, asymptomatic finding, but knowledge of the entity may avoid confusion when initially encountered by diagnostic ultrasound. We review the anatomic imaging features which allow for a confident imaging diagnosis and the clinical relevance of this anomaly.

Howe, Benjamin Matthew; Murthy, Naveen Srinivasa

2012-01-01

63

Differential functioning of Bender Visual-Motor Gestalt Test items.  

PubMed

Differential Item Functioning (DIF) refers to items that do not function the same way for comparable members of different groups. The present study focuses on analyzing and classifying sex-related differential item functioning in the Bender Visual-Motor Gestalt Test. Subjects were 1,052 children attending public schools (513 boys, 539 girls, ages 6-10 years). The protocols were scored using the Bender Graduated Scoring System, which evaluates only the distortion criterion using the Rasch logistic response model. The scoring system fit the Rasch model, although two items were found to be biased by sex. When analyzing differential functioning of items for boys and girls separately, the number of differentially functioning items was equal. PMID:20391894

Sisto, Fermino Fernandes; Dos Santos, Acácia Aparecida Angeli; Noronha, Ana Paula Porto

2010-02-01

64

Versal unfoldings for linear retarded functional differential equations  

Microsoft Academic Search

We consider parametrized families of linear retarded functional differential equations (RFDEs) projected onto finite-dimensional invariant manifolds, and address the question of versality of the resulting parametrized family of linear ordinary differential equations. A sufficient criterion for versality is given in terms of readily computable quantities. In the case where the unfolding is not versal, we show how to construct a

Pietro-Luciano Buono; Victor G. LeBlanc

2003-01-01

65

Rotating Waves in Neutral Partial Functional Differential Equations  

Microsoft Academic Search

General results on the existence and global continuation of rotating waves are established for partial neutral functional differential equations defined on the unit circle. These results are applied to a class of coupled lossless transmission lines.

J. Wu; H. Xia

1999-01-01

66

Local behavior of autonomous neutral functional differential equations.  

NASA Technical Reports Server (NTRS)

Basic problems for a special class of neutral functional differential equations (NFDE) are formulated, and some contributions to a general qualitative theory in the neighborhood of an equilibrium point are indicated. The properties of a NFDE (G,f) are examined to determine in what sense these properties are insensitive to small changes in (G,f) in the topology G x F. The special class of equations that is introduced includes retarded functional differential equations and difference equations.

Hale, J. K.

1972-01-01

67

Generating functionals and Lagrangian partial differential equations  

SciTech Connect

The main goal of this paper is to derive an alternative characterization of the multisymplectic form formula for classical field theories using the geometry of the space of boundary values. We review the concept of Type-I/II generating functionals defined on the space of boundary data of a Lagrangian field theory. On the Lagrangian side, we define an analogue of Jacobi's solution to the Hamilton–Jacobi equation for field theories, and we show that by taking variational derivatives of this functional, we obtain an isotropic submanifold of the space of Cauchy data, described by the so-called multisymplectic form formula. As an example of the latter, we show that Lorentz's reciprocity principle in electromagnetism is a particular instance of the multisymplectic form formula. We also define a Hamiltonian analogue of Jacobi's solution, and we show that this functional is a Type-II generating functional. We finish the paper by defining a similar framework of generating functions for discrete field theories, and we show that for the linear wave equation, we recover the multisymplectic conservation law of Bridges.

Vankerschaver, Joris; Liao, Cuicui; Leok, Melvin [Department of Mathematics, University of California, San Diego, 9500 Gilman Drive, Dept. 0112, La Jolla, California 92093-0112 (United States)] [Department of Mathematics, University of California, San Diego, 9500 Gilman Drive, Dept. 0112, La Jolla, California 92093-0112 (United States)

2013-08-15

68

Teaching Techniques for Accessory Percussion  

ERIC Educational Resources Information Center

Everyone is familiar with the main percussion instruments of the contemporary orchestra: bass drum, snare drum, suspended cymbal, vibraphone, and timpani. But as source material broadens, so do the demands placed on the percussion section. Accessory, or auxiliary percussion, can make the difference between a typical rendition of a well-known piece…

Micallef, Ken

2007-01-01

69

Accessory cell function in immune responses in vivo: enhancing effect of radioresistant spleen cells on antibody response to SRBC in rats.  

PubMed Central

Spleen cells taken 4 days after lethal irradiation of Lewis rat were used as a source of radioresistant accessory cells. The transfer of 2 x 10(6) cells into syngeneic recipients significantly enhanced the antibody response to an immunogenic dose of SRBC, if given immediately prior to antigen. The enhancing effect was not observed if radioresistant cells were transferred 24 h or later after immunization. Elimination of adherent or phagocytic cells abolished the enhancing capacity of the radioresistant spleen cells. One hour pre-incubation in medium containing 0.4 mg/ml kappa carrageenan potentiated rather than inhibited the enhancing effect of radioresistant spleen cells. IgG PFC response appear to be more sensitive to the effect of the transferred spleen cells as compared with the direct (IgM) PFC response. It is concluded that activated splenic macrophages may enhance antibody response when transferred, at the time of immunization, into an immunocompetent host. Possible mechanisms of action are discussed.

Lukic, M L; Simic, M M

1980-01-01

70

Differential Forms Basis Functions for Better Conditioned Integral Equations  

SciTech Connect

Differential forms offer a convenient way to classify physical quantities and set up computational problems. By observing the dimensionality and type of derivatives (divergence,curl,gradient) applied to a quantity, an appropriate differential form can be chosen for that quantity. To use these differential forms in a simulation, the forms must be discretized using basis functions. The 0-form through 2-form basis functions are formed for surfaces. Twisted 1-form and 2-form bases will be presented in this paper. Twisted 1-form (1-forms) basis functions ({Lambda}) are divergence-conforming edge basis functions with units m{sup -1}. They are appropriate for representing vector quantities with continuous normal components, and they belong to the same function space as the commonly used RWG bases [1]. They are used here to formulate the frequency-domain EFIE with Galerkin testing. The 2-form basis functions (f) are scalar basis functions with units m{sup -2} and with no enforced continuity between elements. At lowest order, the 2-form basis functions are similar to pulse basis functions. They are used here to formulate an electrostatic integral equation. It should be noted that the derivative of an n-form differential form basis function is an (n+1)-form, i.e. the derivative of a 1-form basis function is a 2-form. Because the basis functions are constructed such that they have spatial units, the spatial units are removed from the degrees of freedom, leading to a better-conditioned system matrix. In this conference paper, we look at the performance of these differential forms and bases by examining the conditioning of matrix systems for electrostatics and the EFIE. The meshes used were refined across the object to consider the behavior of these basis transforms for elements of different sizes.

Fasenfest, B; White, D; Stowell, M; Rieben, R; Sharpe, R; Madsen, N; Rockway, J D; Champagne, N J; Jandhyala, V; Pingenot, J

2005-01-13

71

Differential Impact of Executive Function on Visual Memory Tasks  

Microsoft Academic Search

Despite their common use in neuropsychological evaluation, little is known about the differential contribution of executive functioning to visual memory tests. In this study, hierarchical regression was used to determine the role of executive functioning on the Visual Reproduction subtest of the Wechsler Memory Scale—Third Edition, and the Rey-Osterrieth Complex Figure (ROCF) in a mixed neurological sample of 193 patients.

Richard O. Temple; Jennifer Duncan Davis; Ilana Silverman; Geoffrey Tremont

2006-01-01

72

A note on the automated differentiation of implicit functions  

SciTech Connect

This paper answers the question: Can automated differentiation be used on functions that are defined implicitly, recursively, or iteratively Consider, for example, the simple function x(m) defined by the equation, x(m) {equals} cos(m{center dot}x(m)).

Michelotti, L.

1991-06-27

73

Electrical recordings from the accessory olfactory bulb in VNO-AOB ex vivo preparations.  

PubMed

Electrical recordings from individual accessory olfactory bulb neurons allow exploration of the functional properties of this important pheromonal processing circuit. Several approaches to performing such recordings have been used. Here, we describe ex vivo methods that we have found useful for recording from accessory olfactory bulb neurons using simple extracellular glass electrodes. PMID:24014366

Meeks, Julian P; Holy, Timothy E

2013-01-01

74

Hyperglycemia enhances function and differentiation of adult rat cardiac fibroblasts.  

PubMed

Diabetes is an independent risk factor for cardiovascular disease that can eventually cause cardiomyopathy and heart failure. Cardiac fibroblasts (CF) are the critical mediators of physiological and pathological cardiac remodeling; however, the effects of hyperglycemia on cardiac fibroblast function and differentiation is not well known. Here, we performed a comprehensive investigation on the effects of hyperglycemia on cardiac fibroblasts and show that hyperglycemia enhances cardiac fibroblast function and differentiation. We found that high glucose treatment increased collagen I, III, and VI gene expression in rat adult cardiac fibroblasts. Interestingly, hyperglycemia increased CF migration and proliferation that is augmented by collagen I and III. Surprisingly, we found that short term hyperglycemia transiently inhibited ERK1/2 activation but increased AKT phosphorylation. Finally, high glucose treatment increased spontaneous differentiation of cardiac fibroblasts to myofibroblasts with increasing passage compared with low glucose. Taken together, these findings suggest that hyperglycemia induces cardiac fibrosis by modulating collagen expression, migration, proliferation, and differentiation of cardiac fibroblasts. PMID:24959995

Shamhart, Patricia E; Luther, Daniel J; Adapala, Ravi K; Bryant, Jennifer E; Petersen, Kyle A; Meszaros, J Gary; Thodeti, Charles K

2014-07-01

75

Schizotypy, marijuana, and differential item functioning.  

PubMed

At least five studies report elevated schizotypy scores in cannabis users. The current research confirms higher schizotypy scores in regular cannabis users. Nevertheless, further analyses reveal that select items on the brief version of the Schizotypal Personality Questionnaire do not function comparably in current and former users. Multiple statistical approaches confirmed this problem, including the Mantel-Haenszel statistic, Rasch difficulty estimates, a logistic regression approach, the Breslow-Day (BD) statistic, and a combined decision rule using Mantel-Haenszel and BD together. Cannabis users appear to misinterpret at least one item, "I sometimes use words in unusual ways" making them more likely to endorse it even if they are no more schizotypal than the former users. Users might consider cannabis-related slang as an unusual use of words. Removing problematic items does not decrease the internal consistency of the measure, but eliminates the significant difference between current and former users. These results suggest that links between cannabis use and schizotypy require cautious interpretation and may arise from measurement problems. PMID:16953519

Earleywine, Mitch

2006-10-01

76

Zonal organization of the mammalian main and accessory olfactory systems.  

PubMed Central

Zonal organization is one of the characteristic features observed in both main and accessory olfactory systems. In the main olfactory system, most of the odorant receptors are classified into four groups according to their zonal expression patterns in the olfactory epithelium. Each group of odorant receptors is expressed by sensory neurons distributed within one of four circumscribed zones. Olfactory sensory neurons in a given zone of the epithelium project their axons to the glomeruli in a corresponding zone of the main olfactory bulb. Glomeruli in the same zone tend to represent similar odorant receptors having similar tuning specificity to odorants. Vomeronasal receptors (or pheromone receptors) are classified into two groups in the accessory olfactory system. Each group of receptors is expressed by vomeronasal sensory neurons in either the apical or basal zone of the vomeronasal epithelium. Sensory neurons in the apical zone project their axons to the rostral zone of the accessory olfactory bulb and form synaptic connections with mitral tufted cells belonging to the rostral zone. Signals originated from basal zone sensory neurons are sent to mitral tufted cells in the caudal zone of the accessory olfactory bulb. We discuss functional implications of the zonal organization in both main and accessory olfactory systems.

Mori, K; von Campenhause, H; Yoshihara, Y

2000-01-01

77

Unusual accessory tendon connecting the hallucal extensors.  

PubMed

During routine dissection of an adult human cadaver, a suite of tendinous anomalies was discovered in the left hallucal region. Whereas the main tendon of the extensor hallucis longus muscle inserted normally, two accessory tendons were found coursing medial and lateral to the main tendon. The most lateral tendon originated from a supernumerary muscle belly and merged with the tendon of extensor hallucis brevis to form a composite tendon. The most medial tendon crossed the metatarsophalangeal joint and joined the composite tendon deep to the tendon of extensor hallucis longus. A terminal tendon, consisting of these three contributions, inserted upon the proximal hallucal phalanx. This variant likely arose due to atypical differentiation of the common extensor muscle mass during development, and is of particular significance to clinicians performing arthroscopy, tendon transfers, and other surgical procedures. PMID:19159364

Hill, Robert V; Gerges, Luke

2008-12-01

78

Unmasking of the trigemino-accessory reflex in accessory facial anastomosis  

PubMed Central

OBJECTIVE—To evaluate the possible blink reflex responses in facial muscles reinnervated by the accessory nerve.?METHOD—Eleven patients with a complete facial palsy were submitted to a surgical repair by an accessory facial nerve anastomosis (AFA). In this pathological group, blink reflex was studied by means of percutaneous electrical stimulation of the supraorbital nerve and recording from the orbicularis oculi muscle. A control group comprised seven normal people and seven patients with a complete Bell's facial palsy; in this group, responses on the sternocleidomastoideus (SCM) muscles were studied after supraorbital nerve stimulation.?RESULTS—All the patients with AFA showed a consistent degree of facial reinnervation. Ten out of the 11 patients with AFA showed reflex responses; in six, responses were configured by a double component pattern, resembling the R1 and R2 components of the blink reflex; three patients had an R1-like response and one patient showed a unique R2 component. Mean values of latencies were 15.2 (SD 4.6) ms for the R1 and 85.3 (SD 9.6) ms for the R2. In the control group, eight out of 14 people had evidence of reflex responses in the SCM muscles; these were almost exclusively configured by a bilateral late component (mean latency 63.5 (SD15.9) ms) and only one of the subjects showed an early response at 11ms.?CONCLUSION—The trigemino-accessory reflex response in the pathological group was more complex and of a significantly higher incidence than in the control group. These differences could be tentatively explained by a mechanism of synaptic plasticity induced by the impairment of the efferent portion of the reflex. This could unmask the central linking between the trigeminal and the accessory limbs of the reflex. The findings described could be a demonstration of neurobionomic function in the repairing process of the nervous system.??

Esteban, A.; Prieto, J.

1999-01-01

79

Crystallization of accessory phases in magmas by local saturation adjacent to phenocrysts  

SciTech Connect

Accessory minerals commonly occur attached to or included in the major crystalline phases of felsic and some intermediate igneous rocks. Apatite is particularly common an inclusions, but Fe-Ti oxides, pyrrhotite, zircon, monazite, chevkinite and xenotime are also known from silicic rocks. Accessories may nucleate near the host crystal/liquid interface as a result of local saturation owing to formation of a differentiated chemical boundary layer in which accessory mineral solubility would be lower than in the surrounding liquid. Diffusion must dominate over convection as a mode of mass transfer near the advancing crystal/liquid interface in order for a boundary layer to exist. Accumulation of essential structural constituent elements of accessory minerals owing to their slow diffusion in evolved silicate melt also may force local saturation, but this is not a process that applies to all cases. Local saturation is an attractive mechanism for enhancing fractionation during crystallization differentiation. If accessory minerals attached to or included in phenocrysts formed because of local saturation, their host phenocrysts must have grown rapidly when accessories nucleated in comparison to lifetimes of magma reservoirs. Some inconsistencies remain in a local saturation origin for accessory phases that cannot be evaluated without additional information.

Bacon, C.R. (Geological Survey, Menlo Park, CA (USA))

1989-05-01

80

Differentiability of energy functionals in spin-density-functional theory  

NASA Astrophysics Data System (ADS)

Recently, nonuniqueness of external electrostatic and magnetic fields yielding a given many-electron ground state has been pointed out [K. Capelle and G. Vignale, Phys. Rev. Lett. 86, 5546 (2001); H. Eschrig and W. E. Pickett, Solid State Commun. 118, 123 (2001)], implying the nondifferentiability of the ground-state energy functional of spin-density-functional theory (SDFT), on the basis of which the applicability of widely used DFT methods in SDFT has been put into question and the need for a critical reexamination of those applications has been concluded. Here it is shown, for collinear magnetic fields, that the nonuniqueness of the external potentials in SDFT does not imply the nonexistence of number-conserving functional derivatives as well, with the use of which therefore problems arising from the nondifferentiability are avoided.

Gál, Tamás

2007-06-01

81

Differentiable but exact formulation of density-functional theory  

NASA Astrophysics Data System (ADS)

The universal density functional F of density-functional theory is a complicated and ill-behaved function of the density—in particular, F is not differentiable, making many formal manipulations more complicated. While F has been well characterized in terms of convex analysis as forming a conjugate pair (E, F) with the ground-state energy E via the Hohenberg-Kohn and Lieb variation principles, F is nondifferentiable and subdifferentiable only on a small (but dense) subset of its domain. In this article, we apply a tool from convex analysis, Moreau-Yosida regularization, to construct, for any ? > 0, pairs of conjugate functionals (?E, ?F) that converge to (E, F) pointwise everywhere as ? ? 0+, and such that ?F is (Fréchet) differentiable. For technical reasons, we limit our attention to molecular electronic systems in a finite but large box. It is noteworthy that no information is lost in the Moreau-Yosida regularization: the physical ground-state energy E(v) is exactly recoverable from the regularized ground-state energy ?E(v) in a simple way. All concepts and results pertaining to the original (E, F) pair have direct counterparts in results for (?E, ?F). The Moreau-Yosida regularization therefore allows for an exact, differentiable formulation of density-functional theory. In particular, taking advantage of the differentiability of ?F, a rigorous formulation of Kohn-Sham theory is presented that does not suffer from the noninteracting representability problem in standard Kohn-Sham theory.

Kvaal, Simen; Ekström, Ulf; Teale, Andrew M.; Helgaker, Trygve

2014-05-01

82

Heritability and Control of Differentiated Function in Cultured Cells  

PubMed Central

An established tissue culture cell line which retains a differentiated function in vitro is described. The cell line is of connective tissue origin, and its characteristic property is the synthesis and secretion of acid mucopolysaccharides, mainly hyaluronic acid. This differentiated cell function, the activity of which depends on continuous gene action, was found to be possessed by each of eleven clonal substrains, and is therefore a genetically heritable cell character. Rate of acid mucopolysaccharide biosynthesis falls sharply under the influence of the environmental conditions existing in crowded cultures, and this rate also declines if protein synthesis is directly inhibited with puromycin. Environmental modification of a differentiated product of gene action is thus illustrated in this study.

Davidson, E. H.

1963-01-01

83

Three Classes of Nonparametric Differential Step Functioning Effect Estimators  

ERIC Educational Resources Information Center

The examination of measurement invariance in polytomous items is complicated by the possibility that the magnitude and sign of lack of invariance may vary across the steps underlying the set of polytomous response options, a concept referred to as differential step functioning (DSF). This article describes three classes of nonparametric DSF effect…

Penfield, Randall D.

2008-01-01

84

A Graphic Procedure for Studying Differential Item Functioning.  

ERIC Educational Resources Information Center

A graphic procedure is presented for studying differential item functioning (DIF) that is designed to provide diagnostic information for psychometricians and educators. The procedure provides a signature of each test item that can be used with a summary statistic to flag items with DIF. Advantages and limitations are noted. (SLD)

Diamond, James J.

1992-01-01

85

Detecting Differential Item Functioning Using Logistic Regression Procedures.  

ERIC Educational Resources Information Center

A logistic regression model for characterizing differential item functioning (DIF) between two groups is presented. A distinction is drawn between uniform and nonuniform DIF in terms of model parameters. A statistic for testing the hypotheses of no DIF is developed, and simulation studies compare it with the Mantel-Haenszel procedure. (Author/TJH)

Swaminathan, Hariharan; Rogers, H. Jane

1990-01-01

86

Generalized Mantel-Haenszel Methods for Differential Item Functioning Detection  

ERIC Educational Resources Information Center

Mantel-Haenszel methods comprise a highly flexible methodology for assessing the degree of association between two categorical variables, whether they are nominal or ordinal, while controlling for other variables. The versatility of Mantel-Haenszel analytical approaches has made them very popular in the assessment of the differential functioning

Fidalgo, Angel M.; Madeira, Jaqueline M.

2008-01-01

87

Disentangling Sources of Differential Item Functioning in Multilanguage Assessments.  

ERIC Educational Resources Information Center

Disentangled sources of differential item functioning (DIF) in a multilanguage assessment for which multiple factors were expected to be causing DIF. Data for the Third International Mathematics and Science study for four countries and two languages (3,000 to 11,000 cases in each comparison group) reveal amounts and sources of DIF. (SLD)

Ercikan, Kadriye

2002-01-01

88

Bounded and periodic solutions of nonlinear functional differential equations  

SciTech Connect

Conditions for the existence of bounded and periodic solutions of the nonlinear functional differential equation d{sup m}x(t)/dt{sup m} + (Fx)(t) = h(t), t element of R, are presented, involving local linear approximations to the operator F. Bibliography: 23 titles.

Slyusarchuk, Vasilii E [Ukranian State Academy of Water Economy (Ukraine)

2012-05-31

89

Differential Item Functioning on the Graduate Management Admission Test.  

ERIC Educational Resources Information Center

The purpose of this study was to identify differentially functioning items on operational administrations of the Graduate Management Admission Test (GMAT) through the use of the Mantel-Haenszel statistic. Retrospective analyses of data collected over 3 years are reported for black/white and female/male comparisons for the Verbal and Quantitative…

O'Neill, Kathleen A.; And Others

90

Effect of Multiple Testing Adjustment in Differential Item Functioning Detection  

ERIC Educational Resources Information Center

In a typical differential item functioning (DIF) analysis, a significance test is conducted for each item. As a test consists of multiple items, such multiple testing may increase the possibility of making a Type I error at least once. The goal of this study was to investigate how to control a Type I error rate and power using adjustment…

Kim, Jihye; Oshima, T. C.

2013-01-01

91

Testing for Differential Item Functioning with Measures of Partial Association  

ERIC Educational Resources Information Center

Differential item functioning (DIF) occurs when an item on a test or questionnaire has different measurement properties for one group of people versus another, irrespective of mean differences on the construct. There are many methods available for DIF assessment. The present article is focused on indices of partial association. A family of average…

Woods, Carol M.

2009-01-01

92

A Comparison of Methods for Detecting Differential Distractor Functioning  

ERIC Educational Resources Information Center

This study examined the effectiveness of the odds-ratio method (Penfield, 2008) and the multinomial logistic regression method (Kato, Moen, & Thurlow, 2009) for measuring differential distractor functioning (DDF) effects in comparison to the standardized distractor analysis approach (Schmitt & Bleistein, 1987). Students classified as participating…

Koon, Sharon

2010-01-01

93

Empirical Selection of Anchors for Tests of Differential Item Functioning  

ERIC Educational Resources Information Center

Differential item functioning (DIF) occurs when items on a test or questionnaire have different measurement properties for one group of people versus another, irrespective of group-mean differences on the construct. Methods for testing DIF require matching members of different groups on an estimate of the construct. Preferably, the estimate is…

Woods, Carol M.

2009-01-01

94

Differential Item Functioning (DIF): Current Problems and Future Directions  

ERIC Educational Resources Information Center

With the rising concerns over the fairness of language tests, Differential Item Functioning (DIF) has been increasingly applied in bias analysis. Despite its widespread use in psychometric circles, DIF is facing a number of serious problems. This paper is an attempt to shed light on a number of the issues involved in DIF analysis. Specifically,…

Karami, Hossein; Salmani Nodoushan, Mohammad Ali

2011-01-01

95

Efficient differentiation of functional hepatocytes from human embryonic stem cells.  

PubMed

Differentiation of human embryonic stem cells (hESCs) to specific functional cell types can be achieved using methods that mimic in vivo embryonic developmental programs. Current protocols for generating hepatocytes from hESCs are hampered by inefficient differentiation procedures that lead to low yields and large cellular heterogeneity. We report here a robust and highly efficient process for the generation of high-purity (70%) hepatocyte cultures from hESCs that parallels sequential hepatic development in vivo. Highly enriched populations of definitive endoderm were generated from hESCs and then induced to differentiate along the hepatic lineage by the sequential addition of inducing factors implicated in physiological hepatogenesis. The differentiation process was largely uniform, with cell cultures progressively expressing increasing numbers of hepatic lineage markers, including GATA4, HNF4alpha, alpha-fetoprotein, CD26, albumin, alpha-1-antitrypsin, Cyp7A1, and Cyp3A4. The hepatocytes exhibited functional hepatic characteristics, such as glycogen storage, indocyanine green uptake and release, and albumin secretion. In a mouse model of acute liver injury, the hESC-derived definitive endoderm differentiated into hepatocytes and repopulated the damaged liver. The methodology described here represents a significant step toward the efficient generation of hepatocytes for use in regenerative medicine and drug discovery. PMID:18292207

Agarwal, Sadhana; Holton, Katherine L; Lanza, Robert

2008-05-01

96

Adenosine receptors in regulation of dendritic cell differentiation and function  

PubMed Central

Differentiation of functional dendritic cells (DCs) critically depends on the microenvironment. DCs differentiate in hypoxic tumor sites and inflamed or damaged tissue. Because local concentrations of adenosine reach high physiologically relevant levels in these conditions, we assessed the expression of adenosine receptors and the effect of their activation on differentiation of human monocytes and mouse peritoneal macrophages and hematopoietic progenitor cells (HPCs) into myeloid DCs. Stimulation of adenosine receptors skews DC differentiation toward a distinct cell population characterized by expression of both DC and monocyte/macrophage cell surface markers. Pharmacologic analysis and experiments with cells from A2B adenosine receptor knockout mice identified A2B receptor as the mediator of adenosine effects on DCs. Unlike normal myeloid DCs, adenosine-differentiated DCs have impaired allostimulatory activity and express high levels of angiogenic, pro-inflammatory, immune suppressor, and tolerogenic factors, including VEGF, IL-8, IL-6, IL-10, COX-2, TGF-?, and IDO. They promoted tumor growth if injected into tumors implanted in mice. Using adenosine desaminase knockout animals, we showed that DCs with proangiogenic phenotype are highly abundant under conditions associated with elevated levels of extracellular adenosine in vivo. Adenosine signaling through A2B receptor is an important factor of aberrant DC differentiation and generation of tolerogenic, angiogenic, and proinflammatory cells.

Novitskiy, Sergey V.; Ryzhov, Sergey; Zaynagetdinov, Rinat; Goldstein, Anna E.; Huang, Yuhui; Tikhomirov, Oleg Y.; Blackburn, Michael R.; Biaggioni, Italo; Carbone, David P.; Feoktistov, Igor

2008-01-01

97

Adenosine receptors in regulation of dendritic cell differentiation and function.  

PubMed

Differentiation of functional dendritic cells (DCs) critically depends on the microenvironment. DCs differentiate in hypoxic tumor sites and inflamed or damaged tissue. Because local concentrations of adenosine reach high physiologically relevant levels in these conditions, we assessed the expression of adenosine receptors and the effect of their activation on differentiation of human monocytes and mouse peritoneal macrophages and hematopoietic progenitor cells (HPCs) into myeloid DCs. Stimulation of adenosine receptors skews DC differentiation toward a distinct cell population characterized by expression of both DC and monocyte/macrophage cell surface markers. Pharmacologic analysis and experiments with cells from A(2B) adenosine receptor knockout mice identified A(2B) receptor as the mediator of adenosine effects on DCs. Unlike normal myeloid DCs, adenosine-differentiated DCs have impaired allostimulatory activity and express high levels of angiogenic, pro-inflammatory, immune suppressor, and tolerogenic factors, including VEGF, IL-8, IL-6, IL-10, COX-2, TGF-beta, and IDO. They promoted tumor growth if injected into tumors implanted in mice. Using adenosine desaminase knockout animals, we showed that DCs with proangiogenic phenotype are highly abundant under conditions associated with elevated levels of extracellular adenosine in vivo. Adenosine signaling through A(2B) receptor is an important factor of aberrant DC differentiation and generation of tolerogenic, angiogenic, and proinflammatory cells. PMID:18559975

Novitskiy, Sergey V; Ryzhov, Sergey; Zaynagetdinov, Rinat; Goldstein, Anna E; Huang, Yuhui; Tikhomirov, Oleg Y; Blackburn, Michael R; Biaggioni, Italo; Carbone, David P; Feoktistov, Igor; Dikov, Mikhail M

2008-09-01

98

Accessory origin of the piriformis muscle.  

PubMed

Incidental finding of an accessory slip of the piriformis muscle in the gluteal region is reported. Following routine dissection of the gluteal region in three formalin-fixed cadavers, an accessory slip of the piriformis was observed. The accessory slip was cleaned, attachments were identified, and dimensions were measured in two parts as fleshy and tendinous parts with a graduated scale to the nearest millimetre. The accessory slip was innervated by a small twig from the sciatic nerve. Having considered the available literature, the accessory slip of piriformis is rare, and if found, could be a cause for the undiagnosed chronic pain in the back and gluteal region, as this accessory slip may compress the sciatic nerve. PMID:18756338

Ravindranath, Y; Manjunath, K Y; Ravindranath, R

2008-08-01

99

21 CFR 878.4960 - Operating tables and accessories and operating chairs and accessories.  

Code of Federal Regulations, 2013 CFR

... FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GENERAL AND PLASTIC SURGERY DEVICES Surgical Devices § 878.4960 Operating tables and accessories and operating chairs and accessories....

2013-04-01

100

Mechanical accessories for mobile teleoperators  

SciTech Connect

The choice of optimum mechanical accessories for mobile teleoperators involves matching the criteria for emergency response with the available technology. This paper presents a general background to teleoperations, a potpourri of the manipulator systems available, and an argument for force reflecting manipulation. The theme presented is that the accomplishment of humanlike endeavors in hostile environments will be most successful when man model capabilities are utilized. The application of recent electronic technology to manipulator development has made new tools available to be applied to emergency response activities. The development activities described are products of the Consolidated Fuel Reprocessing Program at the Oak Ridge National Laboratory. 13 refs., 7 figs.

Feldman, M.J.; Herndon, J.N.

1985-01-01

101

The impact of testicular and accessory sex gland function on sperm chromatin integrity as assessed by the sperm chromatin structure assay (SCSA)  

Microsoft Academic Search

BACKGROUND: The sperm chromatin structure assay (SCSA) provides an objective assessment of sperm chromatin integrity, which is essential for normal sperm function. SCSA is valuable as a fertility marker in epidemiological studies and in the clinical situation. Little is known about the impact of testicular and post-testicular function on SCSA parameters. METHODS: Ejaculates from 278 military conscripts of median age

J. Richthoff; M. Spano; Y. L. Giwercman; B. Frohm; K. Jepson; J. Malm; S. Elzanaty; M. Stridsberg; A. Giwercman

2002-01-01

102

Rax regulates hypothalamic tanycyte differentiation and barrier function in mice.  

PubMed

The wall of the ventral third ventricle is composed of two distinct cell populations: tanycytes and ependymal cells. Tanycytes regulate many aspects of hypothalamic physiology, but little is known about the transcriptional network that regulates their development and function. We observed that the retina and anterior neural fold homeobox transcription factor (Rax) is selectively expressed in hypothalamic tanycytes, and showed a complementary pattern of expression to markers of hypothalamic ependymal cells, such as Rarres2 (retinoic acid receptor responder [tazarotene induced] 2). To determine whether Rax controls tanycyte differentiation and function, we generated Rax haploinsufficient mice and examined their cellular and molecular phenotype in adulthood. These mice appeared grossly normal, but careful examination revealed a thinning of the third ventricular wall and reduction of both tanycyte and ependymal markers. These experiments show that Rax is required for hypothalamic tanycyte and ependymal cell differentiation. Rax haploinsufficiency also resulted in the ectopic presence of ependymal cells in the ?2 tanycytic zone, where few ependymal cells are normally found, suggesting that Rax is selectively required for ?2 tanycyte differentiation. These changes in the ventricular wall were associated with reduced diffusion of Evans Blue tracer from the ventricle to the hypothalamic parenchyma, with no apparent repercussion on the gross anatomical or behavioral phenotype of these mice. In conclusion, we have provided evidence that Rax is required for the normal differentiation and patterning of hypothalamic tanycytes and ependymal cells, as well as for maintenance of the cerebrospinal fluid-hypothalamus barrier. PMID:23939786

Miranda-Angulo, Ana L; Byerly, Mardi S; Mesa, Janny; Wang, Hong; Blackshaw, Seth

2014-03-01

103

Hunting for eruption ages in accessory minerals  

NASA Astrophysics Data System (ADS)

A primary goal in geochronology is to provide precise and accurate ages for tephras that serve as chronostratigraphic markers for constraining the timing and rates of volcanism, sedimentation, climate change, and catastrophic events in Earth history. Zircon remains the most versatile accessory mineral for dating silicic tephras due to its common preservation in distal pyroclastic deposits, as well as the robustness of its U-Pb and U-series systems even after host materials have been hydrothermally altered or weathered. Countless studies document that zircon may be complexly zoned in age due to inheritance, contamination, recycling of antecrysts, protracted crystallization in long-lived magma reservoirs, or any combination of these. Other accessory minerals such as allanite or chevkinite can retain similar records of protracted crystallization. If the goal is to date the durations of magmatic crystallization, differentiation, and/or magma residence, then these protracted chronologies within and between accessory minerals are a blessing. However, if the goal is to date the timing of eruption with high precision, i.e., absolute ages with millennial-scale uncertainties, then this age zoning is a curse. Observations from ion microprobe 238U-230Th dating of Pleistocene zircon and allanite provide insight into the record of near-eruption crystallization in accessory minerals and serve as a guide for high-precision whole-crystal dating. Although imprecise relative to conventional techniques, ion probe analysis allows high-spatial resolution 238U-230Th dating that can document multi-millennial age distributions at the crystal scale. Analysis of unpolished rims and continuous depth profiling of zircon from small and large volume eruptions (e.g., Coso, Mono Craters, Yellowstone) reveals that the final several micrometers of crystallization often yield ages that are indistinguishable from associated eruption ages from the 40Ar/39Ar or (U-Th)/He methods. Using this approach, we have derived relatively precise (± ~ 5%, 2?) U-Th isochron ages from the unpolished rims of pumice-derived allanite and zircon from late Pleistocene Wilson Creek Formation tephras in eastern California, whose ages are controversial and have been difficult to resolve via 40Ar/39Ar and radiocarbon dating. Allanite and zircon rims from Ashes 7-19 in the lower portion of Wilson Creek sediments yield stratigraphically consistent ages of ca. 27 ka to ca. 62 ka, with a minority of crystals identifiable as xenocrysts from early Mono Craters rhyolites. Model ages for the interiors of allanite crystals are mostly < 10 k.y. older than their rims. Tephra deposited during the geomagnetic excursion debated to be either the Mono Lake or Laschamp event yields a rim isochron age of ca. 41 ka. This age is indistinguishable from an independent age of 41 ka derived at the latter excursion's type locality in France (Singer et al., 2009) as well as from age-models for deep-sea sediments. The results are in excellent agreement with a previously determined chronology derived from magnetostratigraphy (Zimmerman et al., 2006). Refs: Singer et al., 2009, EPSL 286: 80-88; Zimmerman et al., 2006, EPSL 252: 94-106

Vazquez, J. A.

2012-12-01

104

Inorganic arsenic impairs differentiation and functions of human dendritic cells  

SciTech Connect

Experimental studies have demonstrated that the antileukemic trivalent inorganic arsenic prevents the development of severe pro-inflammatory diseases mediated by excessive Th1 and Th17 cell responses. Differentiation of Th1 and Th17 subsets is mainly regulated by interleukins (ILs) secreted from dendritic cells (DCs) and the ability of inorganic arsenic to impair interferon-? and IL-17 secretion by interfering with the physiology of DCs is unknown. In the present study, we demonstrate that high concentrations of sodium arsenite (As(III), 1–2 ?M) clinically achievable in plasma of arsenic-treated patients, block differentiation of human peripheral blood monocytes into immature DCs (iDCs) by inducing their necrosis. Differentiation of monocytes in the presence of non-cytotoxic concentrations of As(III) (0.1 to 0.5 ?M) only slightly impacts endocytotic activity of iDCs or expression of co-stimulatory molecules in cells activated with lipopolysaccharide. However, this differentiation in the presence of As(III) strongly represses secretion of IL-12p70 and IL-23, two major regulators of Th1 and Th17 activities, from iDCs stimulated with different toll-like receptor (TLR) agonists in metalloid-free medium. Such As(III)-exposed DCs also exhibit reduced mRNA levels of IL12A and/or IL12B genes when activated with TLR agonists. Finally, differentiation of monocytes with non-cytotoxic concentrations of As(III) subsequently reduces the ability of activated DCs to stimulate the release of interferon-? and IL-17 from Th cells. In conclusion, our results demonstrate that clinically relevant concentrations of inorganic arsenic markedly impair in vitro differentiation and functions of DCs, which may contribute to the putative beneficial effects of the metalloid towards inflammatory autoimmune diseases. Highlights: ? Inorganic arsenic impairs differentiation and functions of human dendritic cells (DCs) ? Arsenite (> 1 ?M) blocks differentiation of dendritic cells by inducing necrosis ? Arsenite (0.1 to 0.5 ?M) slightly reduces endocytotic activity of immature DCs ? Arsenite (0.1 to 0.5 ?M) represses expression of IL-12p70 and IL-23 in activated DCs ? Arsenite (0.1 to 0.5 ?M) reduces the ability of DCs to activate human T lymphocytes.

Macoch, Mélinda; Morzadec, Claudie [UMR INSERM U1085, Institut de Recherche sur la Santé, l'Environnement et le Travail (IRSET), Université de Rennes 1, 2 avenue du Professeur Léon Bernard, 35043 Rennes (France)] [UMR INSERM U1085, Institut de Recherche sur la Santé, l'Environnement et le Travail (IRSET), Université de Rennes 1, 2 avenue du Professeur Léon Bernard, 35043 Rennes (France); Fardel, Olivier [UMR INSERM U1085, Institut de Recherche sur la Santé, l'Environnement et le Travail (IRSET), Université de Rennes 1, 2 avenue du Professeur Léon Bernard, 35043 Rennes (France) [UMR INSERM U1085, Institut de Recherche sur la Santé, l'Environnement et le Travail (IRSET), Université de Rennes 1, 2 avenue du Professeur Léon Bernard, 35043 Rennes (France); Pôle Biologie, Centre Hospitalier Universitaire (CHU) Rennes, 2 rue Henri Le Guilloux, 35033 Rennes (France); Vernhet, Laurent, E-mail: laurent.vernhet@univ-rennes1.fr [UMR INSERM U1085, Institut de Recherche sur la Santé, l'Environnement et le Travail (IRSET), Université de Rennes 1, 2 avenue du Professeur Léon Bernard, 35043 Rennes (France)] [UMR INSERM U1085, Institut de Recherche sur la Santé, l'Environnement et le Travail (IRSET), Université de Rennes 1, 2 avenue du Professeur Léon Bernard, 35043 Rennes (France)

2013-01-15

105

Use of an artificial neural network to localize accessory pathways of Wolff-Parkinson-White syndrome with 12-lead electrocardiogram.  

PubMed

Today, radio-frequency ablation has been shown to be a safe and effective method to treat paroxysmal tachycardia with Wolff-Parkinson-White syndrome. The many criteria reported for localizing the sites of accessory pathways from a 12-lead electrocardiogram have not proven adequate to differentiate the correct sites of accessory pathways for all situations. This study trained an artificial neural network to differentiate the varied features needed to localize 10 sites of accessory pathways. One hundred fifty patients underwent successful catheter ablation, with manifest single and antegradely conducting accessory pathways. Using the two electrocardiogram features of polarity of delta wave and R wave's share of QRS complex, an artificial neural network learned the characteristics of electrocardiogram waves for each site of the 10 accessory pathways through 90 learning cases, and an applicable network model was developed for testing. In 58 of 60 test cases (96.7%), sites of accessory pathways were localized correctly by the network. Based on the method employed in the present study, it thus becomes possible to predict the sites of accessory pathways with Wolff-Parkinson-White syndrome in more detail by using an artificial neural network with a 12-lead electrocardiogram. In the future, when this method is incorporated into a conventional automatic electrocardiogram system which could analyze delta waves and ORS complex, it will become useful to automatically diagnose the locations of the accessory pathways with Wolff-Parkinson-White syndrome in clinical practice. PMID:16531354

Huang, Damin; Yamauchi, Kazunobu; Inden, Yasuya; Yang, Jun; Jiang, Zheng; Ida, Hiromasa; Katsuyama, Kimiko; Wang, Kai; Kato, Ken; Kato, Hiroki

2005-12-01

106

Exp-Function Method for Solving Fractional Partial Differential Equations  

PubMed Central

We extend the Exp-function method to fractional partial differential equations in the sense of modified Riemann-Liouville derivative based on nonlinear fractional complex transformation. For illustrating the validity of this method, we apply it to the space-time fractional Fokas equation and the nonlinear fractional Sharma-Tasso-Olver (STO) equation. As a result, some new exact solutions for them are successfully established.

2013-01-01

107

Nonsmooth generalized guiding functions for periodic differential inclusions  

Microsoft Academic Search

.  We consider the periodic problem for differential inclusions in\\u000a $$ \\\\user2{\\\\mathbb{R}}^{\\\\rm N} $$ with a nonconvex-valued orientor field F(t, ?), which is lower semicontinuous in\\u000a $$ \\\\zeta \\\\in \\\\user2{\\\\mathbb{R}}^{\\\\rm N} $$ Using the notion of a nonsmooth, locally Lipschitz generalized guiding function,\\u000a we prove that the inclusion has periodic solutions. We have two such existence theorems. We also study the

Michael Filippakis; Leszek Gasi?ski; Nikolaos S. Papageorgiou

2006-01-01

108

The sea lamprey has a primordial accessory olfactory system  

PubMed Central

Background A dual olfactory system, represented by two anatomically distinct but spatially proximate chemosensory epithelia that project to separate areas of the forebrain, is known in several classes of tetrapods. Lungfish are the earliest evolving vertebrates known to have this dual system, comprising a main olfactory and a vomeronasal system (VNO). Lampreys, a group of jawless vertebrates, have a single nasal capsule containing two anatomically distinct epithelia, the main (MOE) and the accessory olfactory epithelia (AOE). We speculated that lamprey AOE projects to specific telencephalic regions as a precursor to the tetrapod vomeronasal system. Results To test this hypothesis, we characterized the neural circuits and molecular profiles of the accessory olfactory epithelium in the sea lamprey (Petromyzon marinus). Neural tract-tracing revealed direct and reciprocal connections with the dorsomedial telencephalic neuropil (DTN) which in turn projects directly to the dorsal pallium and the rostral hypothalamus. High-throughput sequencing demonstrated that the main and the accessory olfactory epithelia have virtually identical profiles of expressed genes. Real time quantitative PCR confirmed expression of representatives of all 3 chemoreceptor gene families identified in the sea lamprey genome. Conclusion Anatomical and molecular evidence shows that the sea lamprey has a primordial accessory olfactory system that may serve a chemosensory function.

2013-01-01

109

21 CFR 872.5410 - Orthodontic appliance and accessories.  

Code of Federal Regulations, 2010 CFR

...2009-04-01 2009-04-01 false Orthodontic appliance and accessories. 872...Therapeutic Devices § 872.5410 Orthodontic appliance and accessories. (a) Identification. An orthodontic appliance and accessories is a...

2009-04-01

110

21 CFR 872.5410 - Orthodontic appliance and accessories.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 2010-04-01 false Orthodontic appliance and accessories. 872...Therapeutic Devices § 872.5410 Orthodontic appliance and accessories. (a) Identification. An orthodontic appliance and accessories is a...

2010-04-01

111

21 CFR 876.5900 - Ostomy pouch and accessories.  

Code of Federal Regulations, 2010 CFR

21 Food and Drugs 8 2010-04-01...2010-04-01 false Ostomy pouch and accessories. ...876.5900 Ostomy pouch and accessories. ...Identification. An ostomy pouch and accessories...but excludes ostomy pouches which incorporate...

2010-04-01

112

21 CFR 876.5900 - Ostomy pouch and accessories.  

Code of Federal Regulations, 2010 CFR

21 Food and Drugs 8 2009-04-01...2009-04-01 false Ostomy pouch and accessories. ...876.5900 Ostomy pouch and accessories. ...Identification. An ostomy pouch and accessories...but excludes ostomy pouches which incorporate...

2009-04-01

113

21 CFR 872.6010 - Abrasive device and accessories.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 2010-04-01 false Abrasive device and accessories. 872.6010...Miscellaneous Devices § 872.6010 Abrasive device and accessories. (a) Identification. An abrasive device and accessories is a device...

2010-04-01

114

21 CFR 872.6010 - Abrasive device and accessories.  

Code of Federal Regulations, 2010 CFR

...2009-04-01 2009-04-01 false Abrasive device and accessories. 872.6010...Miscellaneous Devices § 872.6010 Abrasive device and accessories. (a) Identification. An abrasive device and accessories is a device...

2009-04-01

115

21 CFR 872.6300 - Rubber dam and accessories.  

Code of Federal Regulations, 2013 CFR

...2013-04-01 2013-04-01 false Rubber dam and accessories. 872.6300 Section... Miscellaneous Devices § 872.6300 Rubber dam and accessories. (a) Identification. A rubber dam and accessories is a device...

2013-04-01

116

Accessory Gene Regulator Locus of Staphylococcus intermedius  

Microsoft Academic Search

The accessory gene regulator (agr) locus, a candidate system for the regulation of the production of virulence factors in Staphylococcus intermedius, has been characterized. Using PCR-based genome walking, we have obtained the first complete sequence (3,436 bp) of the accessory gene regulator (agr) gene in this organism. Sequence analysis of the agr gene has identified five open reading frames (ORFs),

Julia M. L. Sung; Peter D. Chantler; David H. Lloyd

2006-01-01

117

The Epigenetic Landscape of Mammary Gland Development and Functional Differentiation  

PubMed Central

Most of the development and functional differentiation in the mammary gland occur after birth. Epigenetics is defined as the stable alterations in gene expression potential that arise during development and proliferation. Epigenetic changes are mediated at the biochemical level by the chromatin conformation initiated by DNA methylation, histone variants, post-translational modifications of histones, non-histone chromatin proteins, and non-coding RNAs. Epigenetics plays a key role in development. However, very little is known about its role in the developing mammary gland or how it might integrate the many signalling pathways involved in mammary gland development and function that have been discovered during the past few decades. An inverse relationship between marks of closed (DNA methylation) or open chromatin (DnaseI hypersensitivity, certain histone modifications) and milk protein gene expression has been documented. Recent studies have shown that during development and functional differentiation, both global and local chromatin changes occur. Locally, chromatin at distal regulatory elements and promoters of milk protein genes gains a more open conformation. Furthermore, changes occur both in looping between regulatory elements and attachment to nuclear matrix. These changes are induced by developmental signals and environmental conditions. Additionally, distinct epigenetic patterns have been identified in mammary gland stem and progenitor cell sub-populations. Together, these findings suggest that epigenetics plays a role in mammary development and function. With the new tools for epigenomics developed in recent years, we now can begin to establish a framework for the role of epigenetics in mammary gland development and disease.

Rijnkels, Monique; Kabotyanski, Elena; Montazer-Torbati, Mohamad B.; Beauvais, C. Hue; Vassetzky, Yegor; Rosen, Jeffrey M.; Devinoy, Eve

2010-01-01

118

Neutrophil extracellular traps promote differentiation and function of fibroblasts.  

PubMed

Neutrophil activation by inflammatory stimuli and the release of extracellular chromatin structures (neutrophil extracellular traps - NETs) have been implicated in inflammatory disorders. Herein, we demonstrate that NETs released by neutrophils treated either with fibrosis-related agents, such as cigarette smoke, magnesium silicate, bleomycin, or with generic NET inducers, such as phorbol 12-myristate 13-acetate, induced activation of lung fibroblasts (LFs) and differentiation into myofibroblast (MF) phenotype. Interestingly, the aforementioned agents or IL-17 (a primary initiator of inflammation/fibrosis) had no direct effect on LF activation and differentiation. MFs treated with NETs demonstrated increased connective tissue growth factor expression, collagen production, and proliferation/migration. These fibrotic effects were significantly decreased after degradation of NETs with DNase1, heparin or myeloperoxidase inhibitor, indicating the key role of NET-derived components in LF differentiation and function. Furthermore, IL-17 was expressed in NETs and promoted the fibrotic activity of differentiated LFs but not their differentiation, suggesting that priming by DNA and histones is essential for IL-17-driven fibrosis. Additionally, autophagy was identified as the orchestrator of NET formation, as shown by inhibition studies using bafilomycin A1 or wortmannin. The above findings were further supported by the detection of NETs in close proximity to alpha-smooth muscle actin (?-SMA)-expressing fibroblasts in biopsies from patients with fibrotic interstitial lung disease or from skin scar tissue. Together, these data suggest that both autophagy and NETs are involved not only in inflammation but also in the ensuing fibrosis and thus may represent potential therapeutic targets in human fibrotic diseases. Copyright © 2014 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd. PMID:24740698

Chrysanthopoulou, Akrivi; Mitroulis, Ioannis; Apostolidou, Eirini; Arelaki, Stella; Mikroulis, Dimitrios; Konstantinidis, Theocharis; Sivridis, Efthimios; Koffa, Maria; Giatromanolaki, Alexandra; Boumpas, Dimitrios T; Ritis, Konstantinos; Kambas, Konstantinos

2014-07-01

119

YlxM Is a Newly Identified Accessory Protein That Influences the Function of Signal Recognition Particle Pathway Components in Streptococcus mutans.  

PubMed

Streptococcus mutans is a cariogenic oral pathogen whose virulence is determined largely by its membrane composition. The signal recognition particle (SRP) protein-targeting pathway plays a pivotal role in membrane biogenesis. S. mutans SRP pathway mutants demonstrate growth defects, cannot contend with environmental stress, and exhibit multiple changes in membrane composition. This study sought to define a role for ylxM, which in S. mutans and numerous other bacteria resides directly upstream of the ffh gene, encoding a major functional element of the bacterial SRP. YlxM was observed as a produced protein in S. mutans. Its predicted helix-turn-helix motif suggested that it has a role as a transcriptional regulator of components within the SRP pathway; however, no evidence of transcriptional regulation was found. Instead, capture enzyme-linked immunosorbent assay (ELISA), affinity chromatography, and bio-layer interferometry (BLI) demonstrated that S. mutans YlxM interacts with the SRP components Ffh and small cytoplasmic RNA (scRNA) but not with the SRP receptor FtsY. In the absence of FtsY, YlxM increased the GTP hydrolysis activity of Ffh alone and in complex with scRNA. However, in the presence of FtsY, YlxM caused an overall diminution of net GTPase activity. Thus, YlxM appears to modulate GTP hydrolysis, a process necessary for proper recycling of SRP pathway components. The presence of YlxM conferred a significant competitive growth advantage under nonstress and acid stress conditions when wild-type and ylxM mutant strains were cultured together. Our results identify YlxM as a component of the S. mutans SRP and suggest a regulatory function affecting GTPase activity. PMID:24659773

Williams, Matthew L; Crowley, Paula J; Hasona, Adnan; Brady, L Jeannine

2014-06-01

120

Leptin functions peripherally to regulate differentiation of mesenchymal progenitor cells.  

PubMed

Leptin functions through a well-documented central neuroendocrine pathway to regulate bone mass. However, the ability of leptin to modulate bone mass through a peripheral mechanism has been debated due to conflicting in vitro results and lack of sufficient in vivo models. We utilized mice with LoxP sites introduced into the long-form leptin receptor (ObRb) gene to determine how leptin regulates mesenchymal progenitor cell (MPC) differentiation and osteoblast function in vitro and in vivo. Rapid phosphorylation of Stat3 after leptin treatment of bone marrow stromal cells (BMSCs) from mice with conditional deletion of ObRb in macrophages (LysM(Cre+F/F)) confirmed expression of functional leptin receptors by BMSCs. Adenovirus-Cre mediated disruption of ObRb in primary stromal cells decreased mineralization and increased adipogenesis. In contrast, BMSCs harvested from leptin-signaling deficient Ob/Ob or Db/Db mice showed increased mineralization. To determine the physiologic relevance of these differences, mice with cell-specific deletion of ObRb in mesenchymal precursors (3.6(Cre+F/F)) or osteoblasts (2.3(Cre+F/F)) were generated. Although the 2.3(Cre+F/F) mice were grossly normal, the 3.6(Cre+F/F) mice displayed mild obesity that was not attributed to food intake. Femurs of 3.6(Cre+F/F) animals showed a 58%-61.9% increase in trabecular bone volume and a 65.5%-74% increase in bone mineral density. Cortical volume and mineral content were also increased 18%-22%. Primary 3.6(Cre+F/F) BMSCs recapitulated the high mineralization phenotype of Ob/Ob and Db/Db BMSCs. We conclude that leptin may have multiple peripheral roles depending on the differentiation state of MPC. Leptin (a) helps maintain MPCs in an undifferentiated state and (b) promotes mineralization of more differentiated osteoblasts. PMID:20506495

Scheller, Erica L; Song, Junhui; Dishowitz, Michael I; Soki, Fabiana Naomi; Hankenson, Kurt D; Krebsbach, Paul H

2010-06-01

121

Localisation of the melanocortin-2-receptor and its accessory proteins in the developing and adult adrenal gland.  

PubMed

The melanocortin-2-receptor (MC2R)/MC2R accessory protein (MRAP) complex is critical to the production of glucocorticoids from the adrenal cortex. Inactivating mutations in either MC2R or MRAP result in the clinical condition familial glucocorticoid deficiency. The localisation of MC2R together with MRAP within the adrenal gland has not previously been reported. Furthermore, MRAP2, a paralogue of MRAP, has been shown in vitro to have a similar function to MRAP, facilitating MC2R trafficking and responsiveness to ACTH. Despite similar MC2R accessory functions, in vivo, patients with inactivating mutations of MRAP fail to be rescued by a functioning MRAP2 gene, suggesting differences in adrenal expression, localisation and/or function between the two MRAPs. In this study on the rat adrenal gland, we demonstrate that while MRAP and MC2R are highly expressed in the zona fasciculata, MRAP2 is expressed throughout the adrenal cortex in low quantities. In the developing adrenal gland, both MRAP and MRAP2 are equally well expressed. The MC2R/MRAP2 complex requires much higher concentrations of ACTH to activate compared with the MC2R/MRAP complex. Interestingly, expression of MC2R and MRAP in the undifferentiated zone would support the notion that ACTH may play an important role in adrenal cell differentiation and maintenance. PMID:21367968

Gorrigan, Rebecca J; Guasti, Leonardo; King, Peter; Clark, Adrian J; Chan, Li F

2011-06-01

122

Suppression subtractive hybridization analysis reveals expression of conserved and novel genes in male accessory glands of the ant Leptothorax gredleri  

PubMed Central

Background During mating, insect males eject accessory gland proteins (Acps) into the female genital tract. These substances are known to affect female post-mating behavior and physiology. In addition, they may harm the female, e.g., in reducing its lifespan. This is interpreted as a consequence of sexual antagonistic co-evolution. Whereas sexual conflict abounds in non-social species, the peculiar life history of social insects (ants, bees, wasps) with lifelong pair-bonding and no re-mating aligns the reproductive interests of the sexes. Harming the female during mating would negatively affect male fitness and sexual antagonism is therefore not expected. Indeed, mating appears to increase female longevity in at least one ant species. Acps are presumed to play a role in this phenomenon, but the underlying mechanisms are unknown. In this study, we investigated genes, which are preferentially expressed in male accessory glands of the ant Leptothorax gredleri, to determine which proteins might be transferred in the seminal fluid. Results By a suppression subtractive hybridization protocol we obtained 20 unique sequences (USs). Twelve had mutual best matches with genes predicted for Apis mellifera and Nasonia vitripennis. Functional information (Gene Ontology) was available only for seven of these, including intracellular signaling, energy-dependent transport and metabolic enzyme activities. The remaining eight USs did not match sequences from other species. Six genes were further analyzed by quantitative RT-PCR in three life cycle stages of male ants. A gene with carboxy-lyase activity and one of unpredicted function were significantly overexpressed in accessory glands of sexually mature males. Conclusions Our study is the first one to investigate differential gene expression in ants in a context related to mating. Our findings indicate that male accessory glands of L. gredleri express a series of genes that are unique to this species, possibly representing novel genes, in addition to conserved ones for which functions can be predicted. Identifying differentially expressed genes might help to better understand molecular mechanisms involved in reproductive processes in eusocial Hymenoptera. While the novel genes could account for rapidly evolving ones driven by intra-sexual conflict between males, conserved genes imply that rather beneficial traits might get fixed by a process described as inter-sexual cooperation between males and females.

2010-01-01

123

Accessory Mental Nerve: A Case Report  

PubMed Central

The presence of an Accessory Mental Nerve (AMN) is rare. The mental foramen is an important landmark in the mandible for administration of local anaesthesia and mental nerve identification and its preservation is of paramount importance in various surgical procedures. This article presents a case of an incidental finding of accessory mental nerves during open reduction and fixation of a compound fracture of left body of mandible. Knowledge on anatomic variations is helpful in diagnosis, treatment planning and management during surgical procedures.

N.S., Mamatha; N.S., Kedarnath; Singh, Madhumathi; Patel, Gourav

2013-01-01

124

The accessory costotransverse foramen: a radioanatomical study.  

PubMed

One hundred fifty-six anatomical specimens of cervical vertebrae and 55 C1 and 53 C2 vertebrae were examined for the presence of an accessory costotransverse foramen. We also reviewed 60 cervical spine computed tomographic (CT) scans. The variations of the costotransverse and accessory foramen are discussed. The frequency of the latter is 19% in the anatomical specimens and 45% in CT scans. The local anatomy and the excellent visualization on axial transverse CT are stressed. PMID:6690492

De Boeck, M; Potvliege, R; Roels, F; De Smedt, E

1984-02-01

125

Measurement equivalence and differential item functioning in family psychology.  

PubMed

Several hypotheses in family psychology involve comparisons of sociocultural groups. Yet the potential for cross-cultural inequivalence in widely used psychological measurement instruments threatens the validity of inferences about group differences. Methods for dealing with these issues have been developed via the framework of item response theory. These methods deal with an important type of measurement inequivalence, called differential item functioning (DIF). The authors introduce DIF analytic methods, linking them to a well-established framework for conceptualizing cross-cultural measurement equivalence in psychology (C.H. Hui and H.C. Triandis, 1985). They illustrate the use of DIF methods using data from the Project on Human Development in Chicago Neighborhoods (PHDCN). Focusing on the Caregiver Warmth and Environmental Organization scales from the PHDCN's adaptation of the Home Observation for Measurement of the Environment Inventory, the authors obtain results that exemplify the range of outcomes that may result when these methods are applied to psychological measurement instruments. PMID:16221024

Bingenheimer, Jeffrey B; Raudenbush, Stephen W; Leventhal, Tama; Brooks-Gunn, Jeanne

2005-09-01

126

Modifying Measures Based on Differential Item Functioning (DIF) Impact Analyses  

PubMed Central

Objectives Measure modification can impact comparability of scores across groups and settings. Changes in items can affect the percent admitting to a symptom. Methods Using item response theory (IRT) methods, well-calibrated items can be used interchangeably, and the exact same item does not have to be administered to each respondent, theoretically permitting wider latitude in terms of modification. Results Recommendations regarding modifications vary, depending on the use of the measure. In the context of research, adjustments can be made at the analytic level by freeing and fixing parameters based on findings of differential item functioning (DIF). The consequences of DIF for clinical decision making depend on whether or not the patient’s performance level approaches the scale decision cutpoint. High-stakes testing may require item removal or separate calibrations to ensure accurate assessment. Discussion Guidelines for modification based on DIF analyses and illustrations of the impact of adjustments are presented.

Teresi, Jeanne A.; Ramirez, Mildred; Jones, Richard N.; Choi, Seung; Crane, Paul K.

2014-01-01

127

Alternative delivery of male accessory gland products.  

PubMed

To increase fertilization success, males transfer accessory gland products (Acps). Several species have evolved unconventional Acps transfer modes, meaning that Acps are transferred separately from the sperm. By surveying the sperm-free Acps transfer cases, we show that these animals have evolved a common strategy to deliver Acps: they all inject Acps directly through the partner's body wall into the hemolymph. Our review of this mode of Acps transfer reveals another striking similarity: they all transfer sperm in packages or via the skin, which may leave little room for Acps transfer via the conventional route in seminal fluid. We synthesise the knowledge about the function, and the effects in the recipients, of the Acps found in the widely diverse taxa (including earthworms, sea slugs, terrestrial snails, scorpions and salamanders) that inject these substances. Despite the clearly independent evolution of the injection devices, these animals have evolved a common alternative strategy to get their partners to accept and/or use their sperm. Most importantly, the evolution of the injection devices for the delivery of Acps highlights how the latter are pivotal for male reproductive success and, hence, strongly influence sexual selection. PMID:24708537

Zizzari, Z Valentina; Smolders, Irene; Koene, Joris M

2014-01-01

128

Alternative delivery of male accessory gland products  

PubMed Central

To increase fertilization success, males transfer accessory gland products (Acps). Several species have evolved unconventional Acps transfer modes, meaning that Acps are transferred separately from the sperm. By surveying the sperm-free Acps transfer cases, we show that these animals have evolved a common strategy to deliver Acps: they all inject Acps directly through the partner’s body wall into the hemolymph. Our review of this mode of Acps transfer reveals another striking similarity: they all transfer sperm in packages or via the skin, which may leave little room for Acps transfer via the conventional route in seminal fluid. We synthesise the knowledge about the function, and the effects in the recipients, of the Acps found in the widely diverse taxa (including earthworms, sea slugs, terrestrial snails, scorpions and salamanders) that inject these substances. Despite the clearly independent evolution of the injection devices, these animals have evolved a common alternative strategy to get their partners to accept and/or use their sperm. Most importantly, the evolution of the injection devices for the delivery of Acps highlights how the latter are pivotal for male reproductive success and, hence, strongly influence sexual selection.

2014-01-01

129

Unmasking of the trigemino-accessory reflex in accessory facial anastomosis  

Microsoft Academic Search

OBJECTIVETo evaluate the possible blink reflex responses in facial muscles reinnervated by the accessory nerve.METHODEleven patients with a complete facial palsy were submitted to a surgical repair by an accessory facial nerve anastomosis (AFA). In this pathological group, blink reflex was studied by means of percutaneous electrical stimulation of the supraorbital nerve and recording from the orbicularis oculi muscle. A

Angel Esteban; Julio Prieto

1999-01-01

130

[Clinical features of accessory parotid gland tumors].  

PubMed

Accessory parotid gland tumors are relatively rare; hence, adequately detailed clinical analyses of these tumors are difficult to perform at a single institution. In this report, we describe the findings for 65 patients [29 men, 36 women; median age, 51 (9-81) years] with accessory parotid gland tumors, consisting of 4 cases documented by us and 61 cases previously reported by other Japanese authors. Approximately 50% of the patients were treated in an otolaryngology department, while the remaining patients were treated in plastic surgery, oral surgery, or dermatology departments. In 4 patients, the results of preoperative fine-needle aspiration cytology indicated that the tumor was benign; however, the postoperative histopathology results revealed malignant tumors. The frequencies of malignant and benign tumors were 44.6% (n = 29) and 55.4% (n = 36), respectively. Mucoepidermoid carcinoma and pleomorphic adenoma were the most frequent types of malignant and benign accessory parotid gland tumors, respectively. Among the various surgical methods that were used, such as direct cheek and intraoral incisions, a standard parotidectomy incision was the most preferred treatment approach for these tumors. Recently, an endoscopic approach has also been found to yield satisfactory results. An optimal approach should be selected after evaluating the advantages and disadvantages of these methods. No definite guidelines are available regarding the choice of elective neck dissection and postoperative radiation therapy for malignant accessory parotid gland tumors. Although tumor resection (plus elective neck dissection) and postoperative radiation therapy have been frequently performed for various kinds of malignant accessory parotid gland tumors to date, additional studies are needed regarding the criteria for selecting elective neck dissection and postoperative radiation therapy. Since the malignancy rate for accessory parotid gland tumors is higher than that for parotid gland tumors, the possibility of malignancy (especially mucoepidermoid carcinoma and carcinoma ex pleomorphic adenoma) should be considered when resecting accessory parotid gland tumors, even if the results of preoperative fine-needle aspiration cytology indicate that the tumor is benign. PMID:24558945

Iguchi, Hiroyoshi; Wada, Tadashi; Yamamoto, Hidefumi; Yamada, Kei; Matsushita, Naoki; Okamoto, Sachimi; Teranishi, Yuichi; Koda, Yuki; Kosugi, Yuki; Yamane, Hideo

2013-12-01

131

Wavefront sensing with the differential optical transfer function  

NASA Astrophysics Data System (ADS)

Recently a new technique for estimating the complex field in the pupil of a telescope from image-plane intensity measurements has been introduced by Codona.1, 2 The simplest form of the method uses two images of a point source, one with a small modification introduced in the pupil. The algorithm to recover the pupil field uses a functional derivative of the optical transfer function (OTF), and is simple and non-iterative. The derivative is approximated empirically by the difference between the Fourier transforms of the two PSFs: the differential OTF or dOTF. In keeping with the Hermitian symmetry of the OTF, the dOTF includes two conjugate copies of the pupil field overlapping at the point of modification. By placing the modification near the edge of the pupil, the overlap region can be kept small. It can be eliminated altogether by using a second modification and a third image. The technique can be used in broadband light, at the cost of blurring in the recovered phase that is proportional to the fractional bandwidth. Although the dOTF is unlikely to find application in high frame rate astronomical adaptive optics, it has many potential uses such as optical shop testing, non-common-path wavefront error estimation, segmented telescope phasing and general imaging system diagnostics. In this paper, we review the dOTF concept, theory, and initial experiments to demonstrate the technique.

Hart, Michael; Codona, Johanan L.

2012-10-01

132

Runx1-mediated regulation of osteoclast differentiation and function.  

PubMed

Excessive bone resorption is the cause of several metabolic bone diseases including osteoporosis. Thus, identifying factors that can inhibit osteoclast formation and/or activity may define new drug targets that can be used to develop novel therapies for these conditions. Emerging evidence demonstrates that the master regulator of hematopoiesis, Runx1, is expressed in preosteoclasts and may influence skeletal health. To examine the potential role of Runx1 in osteoclast formation and function, we deleted its expression in myeloid osteoclast precursors by crossing Runx1 floxed mice (Runx1(F/F)) with CD11b-Cre transgenic mice. Mice lacking Runx1 in preosteoclasts (CD11b-Cre;Runx1(F/F)) exhibited significant loss of femoral trabecular and cortical bone mass compared with that in Cre-negative mice. In addition, serum levels of collagen type 1 cross-linked C-telopeptide, a biomarker of osteoclast-mediated bone resorption, were significantly elevated in CD11b-Cre;Runx1(F/F) mice compared with those in Runx1(F/F) mice. Tartrate-resistant acid phosphatase-positive osteoclasts that differentiated from bone marrow cells of CD11b-Cre;Runx1(F/F) mice in vitro were larger, were found in greater numbers, and had increased bone resorbing activity than similarly cultured cells from Runx1(F/F) mice. CD11b-Cre;Runx1(F/F) bone marrow cells that were differentiated into osteoclasts in vitro also had elevated mRNA levels of osteoclast-related genes including vacuolar ATPase D2, cathepsin K, matrix metalloproteinase 9, calcitonin receptor, osteoclast-associated receptor, nuclear factor of activated T cells cytoplasmic 1, and cFos. These data indicate that Runx1 expression in preosteoclasts negatively regulates osteoclast formation and activity and contributes to overall bone mass. PMID:24606124

Soung, Do Y; Kalinowski, Judith; Baniwal, Sanjeev K; Jacome-Galarza, Christian E; Frenkel, Baruch; Lorenzo, Joseph; Drissi, Hicham

2014-04-01

133

Littoral cell angioma in main and accessory intrapancreatic spleen presenting as splenic rupture.  

PubMed

We report the incidental finding of a nodular mass in the pancreatic tail on a contrast-enhanced computed tomography scan preinterventional to emergency laparotomy for splenic rupture. Because of the past surgical history and radiologic appearance, differential diagnosis included atypical lymphoma in the spleen and regional lymph node, pancreatic adenocarcinoma with splenic metastasis, and intrapancreatic metastase of malignant melanoma; the patient underwent both splenectomy and pancreatic tail resection. A diagnosis of littoral cell angioma in main and accessory intrapancreatic spleen was made. To our knowledge, this is the first description of littoral cell angioma of the spleen involving both main and accessory organ presenting as splenic rupture. PMID:20409532

Pilz, Julia B; Sperschneider, Toralf; Lutz, Thomas; Loosli, Bruno; Maurer, Christoph A

2011-02-01

134

Middle East Respiratory Syndrome Coronavirus Accessory Protein 4a Is a Type I Interferon Antagonist  

PubMed Central

Middle East respiratory syndrome coronavirus (MERS-CoV) causes severe acute respiratory infection with as yet unclear epidemiology. We previously showed that MERS-CoV counteracts parts of the innate immune response in human bronchiolar cells. Here we analyzed accessory proteins 3, 4a, 4b, and 5 for their abilities to inhibit the type I interferon response. Accessory protein 4a was found to block interferon induction at the level of melanoma differentiation-associated protein 5 (MDA5) activation presumably by direct interaction with double-stranded RNA.

Niemeyer, Daniela; Zillinger, Thomas; Muth, Doreen; Zielecki, Florian; Horvath, Gabor; Suliman, Tasnim; Barchet, Winfried; Weber, Friedemann

2013-01-01

135

Epidermoid cyst arising from an intrapancreatic accessory spleen: A case report and review of the literature  

PubMed Central

We describe an epidermoid cyst arising from an accessory spleen of the pancreas. A 56-year-old female with iron deficiency anemia presented with dizziness. During the clinical workup, a 2×4 cm-sized mass was incidentally detected in the tail of the pancreas in a computed tomography (CT) scan. Under a clinical diagnosis of pancreatic cystic malignant tumor, a distal pancreatectomy was carried out. Grossly, the lesion was composed of a solid and cystic portion. Microscopic analysis revealed that the solid portion was an intrapancreatic accessory spleen and the cystic portion was an epidermoid cyst. An epidermoid cyst in an intrapancreatic accessory spleen is extremely rare and hence difficult to diagnose pre-operatively. Taking into account the possibility of such a cyst in the differential diagnosis of intrapancreatic cystic lesion is recommended.

HONG, RAN; CHOI, NAMKYU; SUN, KYUNGHOON; LIM, SHARON; HAN, YUNJU

2013-01-01

136

The morphometry of the accessory leaflets of the tricuspid valve in a four cuspidal model.  

PubMed

The tricuspid valve is of great importance because of the progress made in operative techniques and invasive cardiology accidents. This structure is more differentiated during evolution than the mitral valve. Accessory leaflets, their frequency and role are still controversial, despite the fact that they have been known from the beginning of the 20th century. The number of leaflets in the tricuspid valve grows in an evolutionary line, but the rules governing their appearance are still not known. The samples were taken from a group of 107 human adult hearts. The four-cuspidal form of the tricuspid valve was used as the simplest model to show the appearance of accessory leaflets for anatomical and statistical examination. On the basis of the results of this study we conclude that the separation of accessory leaflets is a complex process. PMID:18058755

Skwarek, M; Hreczecha, J; Dudziak, M; Jerzemowski, J; Wilk, B; Grzybiak, M

2007-11-01

137

HOXB gene expression and function in differentiating purified hematopoietic progenitors.  

PubMed

Intensive efforts have led to the development of methods for stringent purification of adult hematopoietic progenitor cells (HPCs), particularly from peripheral blood (PB). The purification procedure previously reported by our group (Science, 1990) provided a high HPC frequency, but yielded a low HPC recovery (< or = 5-10%). We therefore developed an improved purification methodology based on "potentiated" negative immunobead selection (Step IIIP) by addition of anti-CD45, -11a and -71 monoclonal antibodies (mAbs) to the previously utilized panel of mAbs. This simplified procedure consistently allows not only high level purification but also abundant recovery of early HPCs: the final Step IIIP cell population (0.95 x 10(6) cells/4 PB donors, mean value) features an 81% HPC frequency and a recovery of 45% of the initial HPCs. The purified HPCs bear the primitive HPC phenotype, i.e., they are consistently CD34+, largely CD33-/45RA-, and in part HLA-DR-/low/CD38-/low/Thy-1+. In optimized semi-solid culture, the purified erythroid/multipotent HPCs give rise to macroscopic colonies (10,000-150,000 cells/clone, > 0.5 mm size colonies). This purification methodology compares favorably with previously reported procedures in terms of combined HPC frequency and recovery: availability of a large number of highly purified, early HPCs will provide an experimental tool for analysis of the molecular/cellular basis of early hematopoiesis. We have investigated by reverse transcription-polymerase chain reaction (RT-PCR) the mRNA expression of homeobox B (HOXB) cluster genes in purified HPCs induced in liquid suspension culture to gradual erythroid or granulopoietic (largely eosinophilic) differentiation and maturation by differential growth factor (GF) stimulus. Only B3 is expressed in quiescent HPCs. After GF treatment B3 expression is enhanced in the initial 24 h and then through erythroid and granulopoietic differentiation and maturation. HOXB4 and B5 are induced at slightly later times and expressed through maturation in both lineages, while B6 is selectively induced in granulocytic differentiation. B2 is transiently expressed at low level in the granulopoietic pathway, while it is detected only in advanced stages of erythropoiesis; B7, B8 and B9 are essentially not detected. Functional studies were performed with antisense phosphorothioate oligomers to HOX mRNAs including: 1) anti-B3 oligomer (alpha-B3) treatment of purified HPCs induces a striking blockade of both erythroid and granulomonocytic colony formation, 2) alpha-B6 selectively and markedly inhibits granulomonocytic colony formation, 3) alpha-B4 and alpha-B5 cause a significant, less pronounced decrease of both colony types and finally, 4) alpha-B2 and alpha-B7, alpha-B9 exert little and no effect respectively. PMID:7488973

Giampaolo, A; Pelosi, E; Valtieri, M; Montesoro, E; Sterpetti, P; Samoggia, P; Camagna, A; Mastroberardino, G; Gabbianelli, M; Testa, U

1995-05-01

138

Controlled Speed Accessory Drive demonstration program  

NASA Technical Reports Server (NTRS)

A Controlled Speed Accessory Drive System was examined in an effort to improve the fuel economy of passenger cars. Concept feasibility and the performance of a typical system during actual road driving conditions were demonstrated. The CSAD system is described as a mechanical device which limits engine accessory speeds, thereby reducing parasitic horsepower losses and improving overall vehicle fuel economy. Fuel consumption data were compiled for fleets of GSA vehicles. Various motor pool locations were selected, each representing different climatic conditions. On the basis of a total accumulated fleet usage of nearly three million miles, an overall fuel economy improvement of 6 percent to 7 percent was demonstrated. Coincident chassis dynamometer tests were accomplished on selected vehicles to establish the effect of different accessory drive systems on exhaust emissions, and to evaluate the magnitude of the mileage benefits which could be derived.

Hoehn, F. W.

1981-01-01

139

Accessory breast tissue mimicking pedunculated lipoma.  

PubMed

Accessory breast tissue is an uncommon condition which occurs in 0.4-6% of women. It is mostly located in the axilla where it can cause diagnostic difficulty, especially if it is unilateral and large. Usually it is bilateral and presents as an asymptomatic mass during pregnancy or lactation. The diagnosis of ectopic breast tissue is important as it can undergo the same pathological changes that occur in a normal breast, such as mastitis, fibrocystic disease and carcinoma. We present a case of a large right-sided accessory breast in a 32-year-old woman that was clinically diagnosed as pedunculated lipoma. However, subsequent histopathological examination proved it to be an accessory breast tissue with lactational changes. PMID:25006058

Husain, Musharraf; Khan, Sabina; Bhat, Ashraf; Hajini, Firdoos

2014-01-01

140

Comparison method of partial functional differential equations and its application  

Microsoft Academic Search

In this paper, the comparison method, which was proposed by Stokes for ordinary differential equations, is extended and applied in the study on the existence of the global solution, and the stability of the steady-state solution of a class of delayed partial differential equations. The obtained results are applied to the mathematical model of a neutron reactor with time delay.

Mengxing He; Zhuoling Ou; Anping Liu

2002-01-01

141

21 CFR 884.2660 - Fetal ultrasonic monitor and accessories.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 2010-04-01 false Fetal ultrasonic monitor and accessories. 884...Monitoring Devices § 884.2660 Fetal ultrasonic monitor and accessories. (a) Identification. A fetal ultrasonic monitor is a device designed to...

2010-04-01

142

21 CFR 884.2660 - Fetal ultrasonic monitor and accessories.  

Code of Federal Regulations, 2010 CFR

...2009-04-01 2009-04-01 false Fetal ultrasonic monitor and accessories. 884...Monitoring Devices § 884.2660 Fetal ultrasonic monitor and accessories. (a) Identification. A fetal ultrasonic monitor is a device designed to...

2009-04-01

143

21 CFR 884.2960 - Obstetric ultrasonic transducer and accessories.  

Code of Federal Regulations, 2010 CFR

...2009-04-01 false Obstetric ultrasonic transducer and accessories. 884...Devices § 884.2960 Obstetric ultrasonic transducer and accessories. (a) Identification. An obstetric ultrasonic transducer is a device used to...

2009-04-01

144

21 CFR 884.2960 - Obstetric ultrasonic transducer and accessories.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 false Obstetric ultrasonic transducer and accessories. 884...Devices § 884.2960 Obstetric ultrasonic transducer and accessories. (a) Identification. An obstetric ultrasonic transducer is a device used to...

2010-04-01

145

21 CFR 884.6120 - Assisted reproduction accessories.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 2010-04-01 false Assisted reproduction accessories. 884.6120 Section...OBSTETRICAL AND GYNECOLOGICAL DEVICES Assisted Reproduction Devices § 884.6120 Assisted reproduction accessories. (a)...

2010-04-01

146

21 CFR 884.6120 - Assisted reproduction accessories.  

Code of Federal Regulations, 2010 CFR

...2009-04-01 2009-04-01 false Assisted reproduction accessories. 884.6120 Section...OBSTETRICAL AND GYNECOLOGICAL DEVICES Assisted Reproduction Devices § 884.6120 Assisted reproduction accessories. (a)...

2009-04-01

147

21 CFR 884.4900 - Obstetric table and accessories.  

Code of Federal Regulations, 2010 CFR

...2009-04-01 2009-04-01 false Obstetric table and accessories. 884.4900...Gynecological Surgical Devices § 884.4900 Obstetric table and accessories. (a) Identification. An obstetric table is a device with adjustable...

2009-04-01

148

21 CFR 884.4900 - Obstetric table and accessories.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 2010-04-01 false Obstetric table and accessories. 884.4900...Gynecological Surgical Devices § 884.4900 Obstetric table and accessories. (a) Identification. An obstetric table is a device with adjustable...

2010-04-01

149

21 CFR 878.3925 - Plastic surgery kit and accessories.  

Code of Federal Regulations, 2013 CFR

...2013-04-01 2013-04-01 false Plastic surgery kit and accessories. 878.3925 ...MEDICAL DEVICES GENERAL AND PLASTIC SURGERY DEVICES Prosthetic Devices § 878.3925 Plastic surgery kit and accessories. (a)...

2013-04-01

150

21 CFR 878.3925 - Plastic surgery kit and accessories.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 2010-04-01 false Plastic surgery kit and accessories. 878.3925 ...MEDICAL DEVICES GENERAL AND PLASTIC SURGERY DEVICES Prosthetic Devices § 878.3925 Plastic surgery kit and accessories. (a)...

2010-04-01

151

21 CFR 878.3925 - Plastic surgery kit and accessories.  

Code of Federal Regulations, 2010 CFR

...2009-04-01 2009-04-01 false Plastic surgery kit and accessories. 878.3925 ...MEDICAL DEVICES GENERAL AND PLASTIC SURGERY DEVICES Prosthetic Devices § 878.3925 Plastic surgery kit and accessories. (a)...

2009-04-01

152

21 CFR 884.2960 - Obstetric ultrasonic transducer and accessories.  

Code of Federal Regulations, 2013 CFR

...2013-04-01 false Obstetric ultrasonic transducer and accessories. 884...Devices § 884.2960 Obstetric ultrasonic transducer and accessories. (a) Identification. An obstetric ultrasonic transducer is a device used to...

2013-04-01

153

21 CFR 884.2660 - Fetal ultrasonic monitor and accessories.  

Code of Federal Regulations, 2013 CFR

...2013-04-01 2013-04-01 false Fetal ultrasonic monitor and accessories. 884...Monitoring Devices § 884.2660 Fetal ultrasonic monitor and accessories. (a) Identification. A fetal ultrasonic monitor is a device designed to...

2013-04-01

154

Growth, development and differentiation: a functional food science approach.  

PubMed

Few other aspects of food supply and metabolism are of greater biological importance than the feeding of mothers during pregnancy and lactation, and of their infants and young children. Nutritional factors during early development not only have short-term effects on growth, body composition and body functions but also exert long-term effects on health, disease and mortality risks in adulthood, as well as development of neural functions and behaviour, a phenomenon called 'metabolic programming'. The interaction of nutrients and gene expression may form the basis of many of these programming effects and needs to be investigated in more detail. The relation between availability of food ingredients and cell and tissue differentiation and its possible uses for promoting health and development requires further exploration. The course of pregnancy, childbirth and lactation as well as human milk composition and the short- and long-term outcome of the child are influenced by the intake of foods and particularly micronutrients, e.g. polyunsaturated fatty acids, Fe, Zn and I. Folic acid supplementation from before conception through the first weeks of pregnancy can markedly reduce the occurrence of severe embryonic malformations; other potential benefits of modulating nutrient supply on maternal and child health should be further evaluated. The evaluation of dietary effects on child growth requires epidemiological and field studies as well as evaluation of specific cell and tissue growth. Novel substrates, growth factors and conditionally essential nutrients (e.g. growth factors, amino acids, polyunsaturated fatty acids) may be potentially useful as ingredients in functional foods and need to be assessed carefully. Intestinal growth, maturation, and adaptation as well as long-term function may be influenced by food ingredients such as oligosaccharides, gangliosides, high-molecular-mass glycoproteins, bile salt-activated lipase, pre- and probiotics. There are indications for some beneficial effects of functional foods on the developing immune response, for example induced by antioxidant vitamins, trace elements, fatty acids, arginine, nucleotides, and altered antigen contents in infant foods. Peak bone mass at the end of adolescence can be increased by dietary means, which is expected to be of long-term importance for the prevention of osteoporosis at older ages. Future studies should be directed to the combined effects of Ca and other constituents of growing bone, such as P, Mg and Zn, as well as vitamins D and K, and the trace elements F and B. Pregnancy and the first postnatal months are critical time periods for the growth and development of the human nervous system, processes for which adequate substrate supplies are essential. Early diet seems to have long-term effects on sensory and cognitive abilities as well as behaviour. The potential beneficial effects of a balanced supply of nutrients such as I, Fe, Zn and polyunsaturated fatty acids should be further evaluated. Possible long-term effects of early exposure to tastes and flavours on later food choice preferences may have a major impact on public health and need to be further elucidated. The use of biotechnology and recombinant techniques may offer the opportunity to include various bioactive substances in special dietary products, such as human milk proteins, peptides, growth factors, which may have beneficial physiological effects, particularly in infancy and early childhood. PMID:9849353

Koletzko, B; Aggett, P J; Bindels, J G; Bung, P; Ferré, P; Gil, A; Lentze, M J; Roberfroid, M; Strobel, S

1998-08-01

155

Carcinoma origin dictates differential skewing of monocyte function  

PubMed Central

Macrophages are versatile cells, which phenotype is profoundly influenced by their environment. Pro-inflammatory classically activated or M1 macrophages, and anti-inflammatory alternatively-activated or M2 macrophages represent two extremes of a continuum of functional states. Consequently, macrophages that are present in tumors can exert tumor-promoting and tumor-suppressing activity, depending on the tumor milieu. In this study we investigated how human monocytes—the precursors of macrophages—are influenced by carcinoma cells of different origin. We demonstrate that monocytes, stimulated with breast cancer supernatant, showed increased expression of interleukin (IL)-10, IL-8 and chemokines CCL17 and CCL22, which are associated with an alternatively-activated phenotype. By contrast, monocytes that were cultured in supernatants of colon cancer cells produced more pro-inflammatory cytokines (e.g., IL-12 and TNF?) and reactive oxygen species. Secretome analysis revealed differential secretion of proteins by colon and breast cancer cell lines, of which the proteoglycan versican was exclusively secreted by colon carcinoma cell lines. Reducing active versican by blocking with monoclonal antibodies or shRNA diminished pro-inflammatory cytokine production by monocytes. Thus, colon carcinoma cells polarize monocytes toward a more classically-activated anti-tumorigenic phenotype, whereas breast carcinomas predispose monocytes toward an alternatively activated phenotype. Interestingly, presence of macrophages in breast or colon carcinomas correlates with poor or good prognosis in patients, respectively. The observed discrepancy in macrophage activation by either colon or breast carcinoma cells may therefore explain the dichotomy between patient prognosis and macrophage presence in these different tumors. Designing new therapies, directing development of monocytes toward M1 activated tumor macrophages in cancer patients, may have great clinical benefits.

Bogels, Marijn; Braster, Rens; Nijland, Philip G.; Gul, Nuray; van de Luijtgaarden, Wendy; Fijneman, Remond J.A.; Meijer, Gerrit A.; Jimenez, Connie R.; Beelen, Robert H.J.; van Egmond, Marjolein

2012-01-01

156

Removal of Accessory Breasts: A Novel Tumescent Liposuction Approach  

Microsoft Academic Search

Background  Accessory breasts, usually with a protuberant appearance, are composed of both the central accessory breast tissue and adjacent\\u000a fat tissue. They are a palpable convexity and cosmetically unsightly. Consequently, patients often desire cosmetic improvement.\\u000a The traditional general surgical treatment for accessory breasts is removal of the accessory breast tissue, fat tissue, and\\u000a covering skin as a whole unit. A rather

Jufeng Fan

2009-01-01

157

Electronic Position Sensor for Power Operated Accessory  

DOEpatents

An electronic position sensor for use with a power operated vehicle accessory, such as a power liftgate. The position sensor includes an elongated resistive circuit that is mounted such that it is stationary and extends along the path of a track portion of the power operated accessory. The position sensor further includes a contact nub mounted to a link member that moves within the track portion such that the contact nub is slidingly biased against the elongated circuit. As the link member moves under the force of a motor-driven output gear, the contact nub slides along the surface of the resistive circuit, thereby affecting the overall resistance of the circuit. The position sensor uses the overall resistance to provide an electronic position signal to an ECU, wherein the signal is indicative of the absolute position of the power operated accessory. Accordingly, the electronic position sensor is capable of providing an electronic signal that enables the ECU to track the absolute position of the power operated accessory.

Haag, Ronald H.; Chia, Michael I.

2005-05-31

158

Biting palsy of the accessory nerve.  

PubMed

A young man was bitten by his girl friend at the anterior border of the left trapezius muscle. Weakness of the trapezius resulted and a longstanding ache in the shoulder developed. Clinically and neurophysiologically, an axonotmesis type crush injury of the accessory nerve was verified. PMID:7431036

Paljärvi, L; Partanen, J

1980-08-01

159

Nipple adenoma arising from axillary accessory breast: a case report  

PubMed Central

Nipple adenoma is a relatively rare benign breast neoplasm, and cases of the disease arising from the axillary accessory breast have very seldom been reported in the English literature. We report a case of nipple adenoma arising from axillary accessory breast including clinical and pathological findings. An 82-year-old woman presented with the complaint of a small painful mass in the right axilla. Physical examination confirmed a well-defined eczematous crusted mass that was 8 mm in size. The diagnosis of nipple adenoma was made from an excisional specimen on the basis of characteristic histological findings. Microscopic structural features included a compact proliferation of small tubules lined by epithelial and myoepithelial cells, and the merging of glandular epithelial cells of the adenoma into squamous epithelial cells in the superficial epidermal layer. Because clinically nipple adenoma may resemble Paget’s disease and pathologically can be misinterpreted as tubular carcinoma, the correct identification of nipple adenoma is an important factor in the differential diagnosis for axillary tumor neoplasms. Virtual slides The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1186821489769063

2012-01-01

160

19 CFR 10.456 - Accessories, spare parts or tools.  

Code of Federal Regulations, 2010 CFR

...2009-04-01 2009-04-01 false Accessories, spare parts or tools. 10.456 Section 10.456 ...Rules of Origin § 10.456 Accessories, spare parts or tools. Accessories, spare parts or tools that form part of the good's...

2009-04-01

161

19 CFR 10.456 - Accessories, spare parts or tools.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 2010-04-01 false Accessories, spare parts or tools. 10.456 Section 10.456 ...Rules of Origin § 10.456 Accessories, spare parts or tools. Accessories, spare parts or tools that form part of the good's...

2010-04-01

162

Detection of accessory spleens with indium 111-labeled autologous platelets  

SciTech Connect

In two patients with recurrent immune thrombocytopenia, accessory splenic tissue was demonstrated by radionuclide imaging following administration of indium 111-labeled autologous platelets. In one of these patients, no accessory splenic tissue was seen on images obtained with technetium 99m sulfur colloid. This new technique provides a simple means for demonstrating accessory spleens and simultaneously evaluating the life-span of autologous platelets.

Davis, H.H., II; Varki, A.; Heaton, W.A.; Siegel, B.A.

1980-01-01

163

21 CFR 878.4950 - Manual operating table and accessories and manual operating chair and accessories.  

Code of Federal Regulations, 2013 CFR

...FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GENERAL AND PLASTIC SURGERY DEVICES Surgical Devices § 878.4950 Manual operating table and accessories and manual operating chair and...

2013-04-01

164

Differential-algebraic approach to constructing representations of commuting differentiations in functional spaces and its application to nonlinear integrable dynamical systems  

NASA Astrophysics Data System (ADS)

There is developed a differential-algebraic approach to studying the representations of commuting differentiations in functional differential rings under nonlinear differential constraints. An example of the differential ideal with the only one conserved quantity is analyzed in detail, the corresponding Lax type representations of differentiations are constructed for an infinite hierarchy of nonlinear dynamical systems of the Burgers and Korteweg-de Vries type. A related infinite bi-Hamiltonian hierarchy of Lax type dynamical systems is constructed.

Prykarpatski, Anatolij K.; Soltanov, Kamal N.; Özça?, Emin

2014-05-01

165

Quasi-Newton methods for parameter estimation in functional differential equations  

NASA Technical Reports Server (NTRS)

A state-space approach to parameter estimation in linear functional differential equations is developed using the theory of linear evolution equations. A locally convergent quasi-Newton type algorithm is applied to distributed systems with particular emphasis on parameters that induce unbounded perturbations of the state. The algorithm is computationally implemented on several functional differential equations, including coefficient and delay estimation in linear delay-differential equations.

Brewer, Dennis W.

1988-01-01

166

A Nested Logit Approach for Investigating Distractors as Causes of Differential Item Functioning  

ERIC Educational Resources Information Center

In multiple-choice items, differential item functioning (DIF) in the correct response may or may not be caused by differentially functioning distractors. Identifying distractors as causes of DIF can provide valuable information for potential item revision or the design of new test items. In this paper, we examine a two-step approach based on…

Suh, Youngsuk; Bolt, Daniel M.

2011-01-01

167

A Comparison of Function-Based Differential Reinforcement Interventions for Children Engaging in Disruptive Classroom Behavior  

ERIC Educational Resources Information Center

This study provides a direct comparison of differential reinforcement of other behavior (DRO) and differential reinforcement of alternative behavior (DRA). Participants included three children in center-based classrooms referred for functional assessments due to disruptive classroom behavior. Functional assessments included interviews and brief…

LeGray, Matthew W.; Dufrene, Brad A.; Sterling-Turner, Heather; Olmi, D. Joe; Bellone, Katherine

2010-01-01

168

Establishing Effect Size Guidelines for Interpreting the Results of Differential Bundle Functioning Analyses Using SIBTEST  

ERIC Educational Resources Information Center

The purpose of this simulation study was to establish general effect size guidelines for interpreting the results of differential bundle functioning (DBF) analyses using simultaneous item bias test (SIBTEST). Three factors were manipulated: number of items in a bundle, test length, and magnitude of uniform differential item functioning (DIF)…

Walker, Cindy M.; Zhang, Bo; Banks, Kathleen; Cappaert, Kevin

2012-01-01

169

Establishing Effect Size Guidelines for Interpreting the Results of Differential Bundle Functioning Analyses Using SIBTEST  

Microsoft Academic Search

The purpose of this simulation study was to establish general effect size guidelines for interpreting the results of differential bundle functioning (DBF) analyses using simultaneous item bias test (SIBTEST). Three factors were manipulated: number of items in a bundle, test length, and magnitude of uniform differential item functioning (DIF) against the focal group in each item in a bundle. A

Cindy M. Walker; Bo Zhang; Kathleen Banks; Kevin Cappaert

2012-01-01

170

Examining Differential Distractor Functioning in Reading Assessments for Students with Disabilities. CRESST Report 743  

ERIC Educational Resources Information Center

This study examines the incorrect response choices, or distractors, by students with disabilities in standardized reading assessments. Differential distractor functioning (DDF) analysis differs from differential item functioning (DIF) analysis, which treats all answers alike and examines all wrong answers against the correct answer. DDF analysis…

Abedi, Jamal; Leon, Seth; Kao, Jenny C.

2008-01-01

171

Some results on boundary value problems for functional differential equations  

Microsoft Academic Search

Existence r,sdts fir a second order bo,mdary vahw p,l)l,nz fir fiuwtiCmal differential ('qati()IlS, are giwn. The rcsflts ar( })asc(t tmth(' nmlin('ar Alterna.tiv, ()f Leray-S('haaMcr and rely .m a lmni t>mls on slut,ims. Th's' rcstlts arc geu'alizations f receipt rr,sdts flom wdinary differential equations aIll ctmil)lcte Cmr ,ar)ier rcstlts Cm the same

P. Ch. Tsamatos; S. K. Ntouyas

1996-01-01

172

Functional Diversification of Drosophila Robo Receptors: Differential Immunoglobulin Domain Functions Promote Distinct Axon Guidance Decisions  

PubMed Central

Summary Recognition molecules of the immunoglobulin (Ig) superfamily control axon guidance in the developing nervous system. Ig-like domains are among the most widely represented protein domains in the human genome and the number of Ig superfamily proteins is strongly correlated with cellular complexity [1]. In Drosophila, three Roundabout (Robo) Ig superfamily receptors respond to their common Slit ligand to regulate axon guidance at the midline: Robo and Robo2 mediate midline repulsion, Robo2 and Robo3 control longitudinal pathway selection, and Robo2 can promote midline crossing [2–5]. How these closely related receptors mediate distinct guidance functions is not understood. We report that the differential functions of Robo2 and Robo3 are specified by their ectodomains and do not reflect differences in cytoplasmic signaling. Functional modularity of Robo2’s ectodomain facilitates multiple guidance decisions: Ig1 and Ig3 of Robo2 confer lateral positioning activity, while Ig2 confers pro-midline crossing activity. Robo2’s distinct functions are not dependent on greater Slit affinity, but instead are due in part to differences in multimerization and receptor-ligand stoichiometry conferred by Robo2’s Ig domains. Together our findings suggest that diverse responses to the Slit guidance cue are imparted by intrinsic structural differences encoded in the extracellular Ig domains of the Robo receptors.

Evans, Timothy A.; Bashaw, Greg J.

2011-01-01

173

Existence results and approximation methods for functional ordinary differential equations with singular diffusion-type differential operators  

Microsoft Academic Search

We derive sufficient conditions for the existence of extremal solutions for a second-order singular functional differential equation subject to initial data. The type of equations that we study here can be regarded as stationary and one-dimensional models for diffusion processes in which the diffusion coefficient is not a constant. We have also tried to relax the regularity assumptions as far

A. Cabada; J. A. Cid; R. L. Pouso

2002-01-01

174

Redundancy of myostatin and growth\\/differentiation factor 11 function  

Microsoft Academic Search

BACKGROUND: Myostatin (Mstn) and growth\\/differentiation factor 11 (Gdf11) are highly related transforming growth factor ? (TGF?) family members that play important roles in regulating embryonic development and adult tissue homeostasis. Despite their high degree of sequence identity, targeted mutations in these genes result in non-overlapping phenotypes affecting distinct biological processes. Loss of Mstn in mice causes a doubling of skeletal

Alexandra C McPherron; Thanh V Huynh; Se-Jin Lee

2009-01-01

175

Lateral facial cleft associated with accessory mandible having teeth, absent parotid gland and peripheral facial weakness.  

PubMed

Transverse facial cleft is a very rare malformation. The Tessier no. 7 cleft is a lateral facial cleft which emanates from oral cavity and extends towards the tragus, involving both soft tissue and skeletal components. Here, we present a case having transverse facial cleft, accessory mandible having teeth, absent parotid gland and ipsilateral peripheral facial nerve weakness. After surgical repair of the cleft in 2-month of age, improvement of the facial nerve function was detected in 3-year of age. Resection of the accessory mandible was planned in 5-6 years of age. PMID:24269646

Ozçelik, D; Toplu, G; Türkseven, A; Senses, D A; Yi?it, B

2014-07-01

176

Imaging diagnosis of accessory and cavitated uterine mass, a rare mullerian anomaly  

PubMed Central

Accessory and Cavitated Uterine Mass (ACUM) is a rare form of developmental Mullerian anomaly seen in young females, which presents as chronic recurrent pelvic pain and severe dysmenorrhea. It is an accessory cavity lying within an otherwise normal uterus. It is lined by functional endometrium and surrounded by myometrium-like smooth muscle cells; hence, it bears striking macroscopic and microscopic resemblance to the uterus. Hysterosalpingography (HSG), Ultrasonography (USG), and Magnetic Resonance Imaging (MRI) form the mainstay of diagnostic imaging. The entity is often under diagnosed; therefore, a high index of suspicion combined with HSG and MRI imaging can help in making an accurate diagnosis.

Jain, Nishchint; Verma, Ritu

2014-01-01

177

HYPERDIRE, HYPERgeometric functions DIfferential REduction: MATHEMATICA-based packages for differential reduction of generalized hypergeometric functions pF,F1,F2,F3,F4  

NASA Astrophysics Data System (ADS)

HYPERDIRE is a project devoted to the creation of a set of Mathematica-based programs for the differential reduction of hypergeometric functions. The current version includes two parts: one, pfq, is relevant for manipulations of hypergeometric functions pFp, and the other, AppellF1F4, for manipulations with Appell hypergeometric functions F1,F2,F3,F4 of two variables.

Bytev, Vladimir V.; Kalmykov, Mikhail Yu.; Kniehl, Bernd A.

2013-10-01

178

Identification of a novel function for the chromatin remodeling protein ING2 in muscle differentiation.  

PubMed

The inhibitor of growth (ING) family of zinc-finger plant homeodomain (PHD)-containing chromatin remodeling protein controls gene expression and has been implicated in the regulation of cell proliferation and death. However, the role of ING proteins in cell differentiation remains largely unexplored. Here, we identify an essential function for ING2 in muscle differentiation. We find that knockdown of ING2 by RNA interference (RNAi) blocks the differentiation of C2C12 cells into myotubes, suggesting that ING2 regulates the myogenic differentiation program. We also characterize a mechanism by which ING2 drives muscle differentiation. In structure-function analyses, we find that the leucine zipper motif of ING2 contributes to ING2-dependent muscle differentiation. By contrast, the PHD domain, which recognizes the histone H3K4me3 epigenetic mark, inhibits the ability of ING2 to induce muscle differentiation. We also find that the Sin3A-HDAC1 chromatin remodeling complex, which interacts with ING2, plays a critical role in ING2-dependent muscle differentiation. These findings define a novel function for ING2 in muscle differentiation and bear significant implications for our understanding of the role of the ING protein family in cell differentiation and tumor suppression. PMID:22808232

Eapen, Shawn A; Netherton, Stuart J; Sarker, Krishna P; Deng, Lili; Chan, Angela; Riabowol, Karl; Bonni, Shirin

2012-01-01

179

Unusual accessory tendon connecting the hallucal extensors  

Microsoft Academic Search

During routine dissection of an adult human cadaver, a suite of tendinous anomalies was discovered in the left hallucal region.\\u000a Whereas the main tendon of the extensor hallucis longus muscle inserted normally, two accessory tendons were found coursing\\u000a medial and lateral to the main tendon. The most lateral tendon originated from a supernumerary muscle belly and merged with\\u000a the tendon

Robert V. Hill; Luke Gerges

2008-01-01

180

Molecular Population Genetics of Male Accessory Gland Proteins in the Drosophila simulans Complex  

Microsoft Academic Search

Accessory gland proteins are a major component of Drosophila seminal fluid. These proteins have a variety of functions and may be subject to sexual selection and\\/or antagonistic evolution between the sexes. Most population genetic data from these proteins are from D. melanogaster and D. simulans. Here, we extend the population genetic analysis of Acp genes to the other simulans complex

Andrew D. Kern; Corbin D. Jones; David J. Begun

2004-01-01

181

Identification and functional analysis of differentially expressed genes related to obesity using DNA microarray.  

PubMed

We looked for differentially expressed genes at different stages of preadipocyte differentiation and examined their functions, based on DNA microarrays of preadipocytes obtained from healthy subjects undergoing cosmetic liposuction. We downloaded gene expression profile GSE25910 from the Gene Expression Omnibus database and identified the differentially expressed genes with packages in R language. The selected differentially expressed genes were further analyzed using bioinformatics methods. Comparing gene expression at different stages of preadipocytes differentiation, we found that expression of 668 and 1007 genes were altered in middle and late stages compared with the early stage, respectively. Function analysis revealed that the differentially expressed genes were mainly related to fatty acid metabolic processes in the former two stages. PMID:24446288

Du, J Y; Yang, H; Tian, D R; Wang, Q M; He, L

2014-01-01

182

Differentiation of human neural progenitor cells in functionalized hydrogel matrices.  

PubMed

Hydrogel-based three-dimensional (3D) scaffolds are widely used in the field of regenerative medicine, translational medicine, and tissue engineering. Recently, we reported the effect of scaffold formation on the differentiation and survival of human neural progenitor cells (hNPCs) using PuraMatrix™ (RADA-16) scaffolds. Here, we were interested in the impact of PuraMatrix modified by the addition of short peptide sequences, based on a bone marrow homing factor and laminin. The culture and differentiation of the hNPCs in the modified matrices resulted in an approximately fivefold increase in neuronal cells. The examination of apoptotic and necrotic cells, as well as the level of the anti-apoptotic protein Bcl-2, indicates benefits for cells hosted in the modified formulations. In addition, we found a trend to lower proportions of apoptotic or necrotic neuronal cells in the modified matrices. Interestingly, the neural progenitor cell pool was increased in all the tested matrices in comparison to the standard 2D culture system, while no difference was found between the modified matrices. We conclude that a combination of elevated neuronal differentiation and a protective effect of the modified matrices underlies the increased proportion of neuronal cells. PMID:23515105

Liedmann, Andrea; Frech, Stefanie; Morgan, Peter J; Rolfs, Arndt; Frech, Moritz J

2012-01-01

183

Differentiation of Human Neural Progenitor Cells in Functionalized Hydrogel Matrices  

PubMed Central

Abstract Hydrogel-based three-dimensional (3D) scaffolds are widely used in the field of regenerative medicine, translational medicine, and tissue engineering. Recently, we reported the effect of scaffold formation on the differentiation and survival of human neural progenitor cells (hNPCs) using PuraMatrix™ (RADA-16) scaffolds. Here, we were interested in the impact of PuraMatrix modified by the addition of short peptide sequences, based on a bone marrow homing factor and laminin. The culture and differentiation of the hNPCs in the modified matrices resulted in an approximately fivefold increase in neuronal cells. The examination of apoptotic and necrotic cells, as well as the level of the anti-apoptotic protein Bcl-2, indicates benefits for cells hosted in the modified formulations. In addition, we found a trend to lower proportions of apoptotic or necrotic neuronal cells in the modified matrices. Interestingly, the neural progenitor cell pool was increased in all the tested matrices in comparison to the standard 2D culture system, while no difference was found between the modified matrices. We conclude that a combination of elevated neuronal differentiation and a protective effect of the modified matrices underlies the increased proportion of neuronal cells.

Liedmann, Andrea; Frech, Stefanie; Morgan, Peter J.; Rolfs, Arndt

2012-01-01

184

Functional significance of differential eNOS translocation.  

PubMed

Nitric oxide (NO) regulates flow and permeability. ACh and platelet-activating factor (PAF) lead to endothelial NO synthase (eNOS) phosphorylation and NO release. While ACh causes only vasodilation, PAF induces vasoconstriction and hyperpermeability. The key differential signaling mechanisms for discriminating between vasodilation and hyperpermeability are unknown. We tested the hypothesis that differential translocation may serve as a regulatory mechanism of eNOS to determine specific vascular responses. We used ECV-304 cells permanently transfected with eNOS-green fluorescent protein (ECVeNOS-GFP) and demonstrated that the agonists activate eNOS and reproduce their characteristic endothelial permeability effects in these cells. We evaluated eNOS localization by lipid raft analysis and immunofluorescence microscopy. After PAF and ACh, eNOS moves away from caveolae. eNOS distributes both in the plasma membrane and Golgi in control cells. ACh (10(-5) M, 10(-4) M) translocated eNOS preferentially to the trans-Golgi network (TGN) and PAF (10(-7) M) preferentially to the cytosol. We suggest that PAF-induced eNOS translocation preferentially to cytosol reflects a differential signaling mechanism related to changes in permeability, whereas ACh-induced eNOS translocation to the TGN is related to vasodilation. PMID:16679407

Sánchez, Fabiola A; Savalia, Nirav B; Durán, Ricardo G; Lal, Brajesh K; Boric, Mauricio P; Durán, Walter N

2006-09-01

185

Functional significance of differential eNOS translocation  

PubMed Central

Nitric oxide (NO) regulates flow and permeability. ACh and platelet-activating factor (PAF) lead to endothelial NO synthase (eNOS) phosphorylation and NO release. While ACh causes only vasodilation, PAF induces vasoconstriction and hyperpermeability. The key differential signaling mechanisms for discriminating between vasodilation and hyperpermeability are unknown. We tested the hypothesis that differential translocation may serve as a regulatory mechanism of eNOS to determine specific vascular responses. We used ECV-304 cells permanently transfected with eNOS-green fluorescent protein (ECVeNOS-GFP) and demonstrated that the agonists activate eNOS and reproduce their characteristic endothelial permeability effects in these cells. We evaluated eNOS localization by lipid raft analysis and immunofluorescence microscopy. After PAF and ACh, eNOS moves away from caveolae. eNOS distributes both in the plasma membrane and Golgi in control cells. ACh (10?5 M, 10?4 M) translocated eNOS preferentially to the trans-Golgi network (TGN) and PAF (10?7 M) preferentially to the cytosol. We suggest that PAF-induced eNOS translocation preferentially to cytosol reflects a differential signaling mechanism related to changes in permeability, whereas ACh-induced eNOS translocation to the TGN is related to vasodilation.

Sanchez, Fabiola A.; Savalia, Nirav B.; Duran, Ricardo G.; Lal, Brajesh K.; Boric, Mauricio P.; Duran, Walter N.

2006-01-01

186

Dermal fibroblasts contribute to multiple tissues in the accessory limb model.  

PubMed

The accessory limb model has become an alternative model for performing investigations of limb regeneration in an amputated limb. In the accessory limb model, a complete patterned limb can be induced as a result of an interaction between the wound epithelium, a nerve and dermal fibroblasts in the skin. Studies should therefore focus on examining these tissues. To date, however, a study of cellular contributions in the accessory limb model has not been reported. By using green fluorescent protein (GFP) transgenic axolotl tissues, we can trace cell fate at the tissue level. Therefore, in the present study, we transgrafted GFP skin onto the limb of a non-GFP host and induced an accessory limb to investigate cellular contributions. Previous studies of cell contribution to amputation-induced blastemas have demonstrated that dermal cells are the progenitors of many of the early blastema cells, and that these cells contribute to regeneration of the connective tissues, including cartilage. In the present study, we have determined that this same population of progenitor cells responds to signaling from the nerve and wound epithelium in the absence of limb amputation to form an ectopic blastema and regenerate the connective tissues of an ectopic limb. Blastema cells from dermal fibroblasts, however, did not differentiate into either muscle or neural cells, and we conclude that dermal fibroblasts are dedifferentiated along its developmental lineage. PMID:20148925

Hirata, Ayako; Gardiner, David M; Satoh, Akira

2010-05-01

187

Antagonism of Innate Immunity by Paramyxovirus Accessory Proteins  

PubMed Central

Paramyxovirinae, a subfamily of Paramyxoviridae, are negative strand RNA viruses comprised of many important human and animal pathogens, which share a high degree of genetic and structural homology. The accessory proteins expressed from the P/V/C gene are major factors in the pathogenicity of the viruses, because of their ability to abrogate various facets of type I interferon (IFN) induction and signaling. Most of the paramyxoviruses exhibit a commonality in their ability to antagonize innate immunity by blocking IFN induction and the Jak/STAT pathway. However, the manner in which the accessory proteins inhibit the pathway differs among viruses. Similarly, there are variations in the capability of the viruses to counteract intracellular detectors (RNA helicases, mda-5 and RIG-I). Furthermore, a functional specificity in the antagonism of the IFN response has been reported, suggesting that specificity in the circumvention of innate immunity restricts viral host range. Available evidence indicates that paramyxoviruses employ specific strategies to antagonize the IFN response of their specific hosts, which is one of the major factors that determine viral pathogenicity and host range.

Chambers, Raychel; Takimoto, Toru

2009-01-01

188

Some properties of solutions of a functional-differential equation of second order with delay.  

PubMed

Existence, uniqueness, data dependence (monotony, continuity, and differentiability with respect to parameter), and Ulam-Hyers stability results for the solutions of a system of functional-differential equations with delays are proved. The techniques used are Perov's fixed point theorem and weakly Picard operator theory. PMID:24683363

Ilea, Veronica Ana; Otrocol, Diana

2014-01-01

189

Prediction sensitivity to functional perturbations in modelling with ordinary differential equations  

Microsoft Academic Search

When modelling any system using ordinary differential equations, the problem arises of gauging the sensitivity of state predictions to arbitrary functional perturbations to the right-hand sides of the chosen differential equations. Assuming that a suitable Riemannian measure of the distance or gap between any two states (as possible predictions) has been chosen, a scalar functionr(·) of the state is defined

D. H. Martin

1980-01-01

190

Differentiation of Cognitive Abilities as a Function of Neuroticism Level: A Measurement Equivalence/Invariance Analysis  

ERIC Educational Resources Information Center

This paper investigates the differentiation of cognitive abilities as a function of neuroticism. Specifically, we examine Eysenck and White's [Eysenck, H. J., and White, P. O. (1964). Personality and the measurement of intelligence. British Journal of Educational Psychology, 24, 197-201.] hypothesis that cognitive abilities are less differentiated

Bonaccio, Silvia; Reeve, Charlie L.

2006-01-01

191

Some Properties of Solutions of a Functional-Differential Equation of Second Order with Delay  

PubMed Central

Existence, uniqueness, data dependence (monotony, continuity, and differentiability with respect to parameter), and Ulam-Hyers stability results for the solutions of a system of functional-differential equations with delays are proved. The techniques used are Perov's fixed point theorem and weakly Picard operator theory.

Ana Ilea, Veronica

2014-01-01

192

Calmodulin is a critical regulator of osteoclastic differentiation, function, and survival  

Microsoft Academic Search

Increased osteoclastic resorption and subsequent bone loss are common features of many debilitating diseases including osteoporosis, bone metastases, Paget's disease, and rheumatoid arthritis. While rapid progress has been made in elucidating the signaling pathways directing osteoclast differentiation and function, a com- prehensive picture is far from complete. Here, we explore the role of the Ca2þ-activated regulator calmodulin in osteoclastic differentiation,

Eric C. Seales; Keith J. Micoli; Jay M. McDonald

2006-01-01

193

Local null controllability of nonlinear functional differential systems in Banach space  

Microsoft Academic Search

Sufficient conditions for the local null controllability of non-linear functional differential systems with unbounded linear operators in Banach space are established. The results are obtained using the semigroup of linear operators, fractional powers of operators, and the Schauder fixed-point theorem. Applications to parabolic differential systems are given.

K. Balachandran; P. Balasubramaniam; J. P. Dauer

1996-01-01

194

Functional gene screening in embryonic stem cells implicates Wnt antagonism in neural differentiation  

Microsoft Academic Search

The multilineage differentiation capacity of mouse embryonic stem (ES) cells offers a potential testing platform for gene products that mediate mammalian lineage determination and cellular specialization. Identification of such differentiation regulators is crucial to harnessing ES cells for pharmaceutical discovery and cell therapy. Here we describe the use of episomal expression technology for functional evaluation of cDNA clones during ES-cell

Jerôme Aubert; Hannah Dunstan; Ian Chambers; Austin Smith

2002-01-01

195

Communication Abnormalities Predict Functional Outcomes in Chronic Schizophrenia: Differential Associations with Social and Adaptive Functions  

PubMed Central

Communication abnormalities are hallmark features of schizophrenia. Despite the prevalence and persistence of these symptoms, little is known about their functional implications. In this study, we examined, in a sample of chronically institutionalized schizophrenia patients (N=317), whether two types of communication abnormalities (i.e., verbal underproductivity and disconnected speech) had differential relationships with social and adaptive outcomes. Baseline ratings of verbal underproductivity, disconnected speech, global cognitive performance, and clinical symptoms, were entered into stepwise regression analyses to examine their relationship with 2.5 year social and adaptive outcomes. At baseline, disconnected speech was significantly associated with socially impolite behavior, while verbal underproductivity was associated with social disengagement and impaired friendships. Both types of communication abnormalities were significantly associated with other types of social skills. Verbal underproductivity predicted follow-up social skills, social engagement, and friendships, accounting for more variance than cognition or symptoms. In contrast to social outcomes, adaptive outcomes were predicted by baseline neurocognition and clinical symptoms, but not communication abnormalities. These findings provide evidence for specific relationships of communication disorder subtypes with diverse impairments in social functions. In this chronically institutionalized sample, communication disorder was a stronger predictor of social, but not adaptive, outcomes than neurocognition or clinical symptoms.

Bowie, Christopher R.; Harvey, Philip D.

2014-01-01

196

DIFFERENTIAL RECURSION RELATIONS FOR LAGUERRE FUNCTIONS ON HERMITIAN MATRICES  

Microsoft Academic Search

In our previous papers [1, 2] we studied Laguerre functions andpolynomials on symmetriccones= H=L. The Laguerre functions `n , n 2 ,form an orthogonal basis in L; d )and are related via the Laplace transformto an orthogonal set in the representation space of a highest weight representations ( ; H ) of the automorphism group G corresponding to a tubedomain

MARK DAVIDSON

2002-01-01

197

Dual functions of TAF7L in adipocyte differentiation.  

PubMed

The diverse transcriptional mechanisms governing cellular differentiation and development of mammalian tissue remains poorly understood. Here we report that TAF7L, a paralogue of TFIID subunit TAF7, is enriched in adipocytes and white fat tissue (WAT) in mouse. Depletion of TAF7L reduced adipocyte-specific gene expression, compromised adipocyte differentiation, and WAT development as well. Ectopic expression of TAF7L in myoblasts reprograms these muscle precursors into adipocytes upon induction. Genome-wide mRNA-seq expression profiling and ChIP-seq binding studies confirmed that TAF7L is required for activating adipocyte-specific genes via a dual mechanism wherein it interacts with PPAR? at enhancers and TBP/Pol II at core promoters. In vitro binding studies confirmed that TAF7L forms complexes with both TBP and PPAR?. These findings suggest that TAF7L plays an integral role in adipocyte gene expression by targeting enhancers as a cofactor for PPAR? and promoters as a component of the core transcriptional machinery.DOI:http://dx.doi.org/10.7554/eLife.00170.001. PMID:23326641

Zhou, Haiying; Kaplan, Tommy; Li, Yan; Grubisic, Ivan; Zhang, Zhengjian; Wang, P Jeremy; Eisen, Michael B; Tjian, Robert

2013-01-01

198

FETAL DEXAMETHASONE EXPOSURE ACCELERATES DEVELOPMENT OF RENAL FUNCTION: RELATIONSHIP TO DOSE, CELL DIFFERENTIATION AND GROWTH INHIBITION  

EPA Science Inventory

Fetal exposure to high doses of glucocorticoids slows cellular development and impairs organ performance, in association with growth retardation. evertheless, low doses of glucocorticoids may enhance cell differentiation and accelerate specific functions. he current study examine...

199

Jordan-type inequalities for differentiable functions and their applications  

Microsoft Academic Search

In this work, we extend Jordan’s inequality to obtain a new type of inequality involving functions and their higher-order derivatives. The result is then used to obtain some higher accurate inequalities of Jordan type.

Shanhe Wu; Lokenath Debnath

2008-01-01

200

Regeneration niche differentiates functional strategies of desert woody plant species  

PubMed Central

Plant communities vary dramatically in the number and relative abundance of species that exhibit facilitative interactions, which contributes substantially to variation in community structure and dynamics. Predicting species’ responses to neighbors based on readily measurable functional traits would provide important insight into the factors that structure plant communities. We measured a suite of functional traits on seedlings of 20 species and mature plants of 54 species of shrubs from three arid biogeographic regions. We hypothesized that species with different regeneration niches—those that require nurse plants for establishment (beneficiaries) versus those that do not (colonizers)—are functionally different. Indeed, seedlings of beneficiary species had lower relative growth rates, larger seeds and final biomass, allocated biomass toward roots and height at a cost to leaf mass fraction, and constructed costly, dense leaf and root tissues relative to colonizers. Likewise at maturity, beneficiaries had larger overall size and denser leaves coupled with greater water use efficiency than colonizers. In contrast to current hypotheses that suggest beneficiaries are less “stress-tolerant” than colonizers, beneficiaries exhibited conservative functional strategies suited to persistently dry, low light conditions beneath canopies, whereas colonizers exhibited opportunistic strategies that may be advantageous in fluctuating, open microenvironments. In addition, the signature of the regeneration niche at maturity indicates that facilitation expands the range of functional diversity within plant communities at all ontogenetic stages. This study demonstrates the utility of specific functional traits for predicting species’ regeneration niches in hot deserts, and provides a framework for studying facilitation in other severe environments. Electronic supplementary material The online version of this article (doi:10.1007/s00442-010-1741-y) contains supplementary material, which is available to authorized users.

Briggs, John M.

2010-01-01

201

Transcriptional activation of melanocortin 2 receptor accessory protein by PPAR? in adipocytes.  

PubMed

Adrenocorticotropic hormone (ACTH) in rodents decreases lipid accumulation and body weight. Melanocortin receptor 2 (MC2R) and MC2R accessory protein (MRAP) are specific receptors for ACTH in adipocytes. Peroxisome proliferator-activated receptor ? (PPAR?) plays a role in the transcriptional regulation of metabolic pathways such as adipogenesis and ?-oxidation of fatty acids. In this study we investigated the transcriptional regulation of MRAP expression during differentiation of 3T3-L1 cells. Stimulation with ACTH affected lipolysis in murine mature adipocytes via MRAP. Putative peroxisome proliferator response element (PPRE) was identified in the MRAP promoter region. In chromatin immunoprecipitation and reporter assays, we observed binding of PPAR? to the MRAP promoter. The mutagenesis experiments showed that the -1209/-1198 region of the MRAP promoter could function as a PPRE site. These results suggest that PPAR? is required for transcriptional activation of the MRAP gene during adipogenesis, which contributes to understanding of the molecular mechanism of lipolysis in adipocytes. PMID:23994134

Kim, Nam Soo; Kim, Yoon-Jin; Cho, Si Young; Lee, Tae Ryong; Kim, Sang Hoon

2013-09-27

202

Transcriptional activation of melanocortin 2 receptor accessory protein by PPAR? in adipocytes  

SciTech Connect

Highlights: •MRAP enhanced HSL expression. •ACTH-mediated MRAP reduced glycerol release. •PPAR? induced MRAP expression. •PPAR? bound to the MRAP promoter. -- Abstract: Adrenocorticotropic hormone (ACTH) in rodents decreases lipid accumulation and body weight. Melanocortin receptor 2 (MC2R) and MC2R accessory protein (MRAP) are specific receptors for ACTH in adipocytes. Peroxisome proliferator-activated receptor ? (PPAR?) plays a role in the transcriptional regulation of metabolic pathways such as adipogenesis and ?-oxidation of fatty acids. In this study we investigated the transcriptional regulation of MRAP expression during differentiation of 3T3-L1 cells. Stimulation with ACTH affected lipolysis in murine mature adipocytes via MRAP. Putative peroxisome proliferator response element (PPRE) was identified in the MRAP promoter region. In chromatin immunoprecipitation and reporter assays, we observed binding of PPAR? to the MRAP promoter. The mutagenesis experiments showed that the ?1209/?1198 region of the MRAP promoter could function as a PPRE site. These results suggest that PPAR? is required for transcriptional activation of the MRAP gene during adipogenesis, which contributes to understanding of the molecular mechanism of lipolysis in adipocytes.

Kim, Nam Soo; Kim, Yoon-Jin [Department of Biology, Research Institute for Basic Science, Kyung Hee University, Seoul 130-701 (Korea, Republic of)] [Department of Biology, Research Institute for Basic Science, Kyung Hee University, Seoul 130-701 (Korea, Republic of); Cho, Si Young [R and D Center, Amore Pacific Corporation, Yongin-si, Gyeonggi-do 446-729 (Korea, Republic of)] [R and D Center, Amore Pacific Corporation, Yongin-si, Gyeonggi-do 446-729 (Korea, Republic of); Lee, Tae Ryong, E-mail: trlee@amorepacific.com [R and D Center, Amore Pacific Corporation, Yongin-si, Gyeonggi-do 446-729 (Korea, Republic of); Kim, Sang Hoon, E-mail: shkim@khu.ac.kr [Department of Biology, Research Institute for Basic Science, Kyung Hee University, Seoul 130-701 (Korea, Republic of)

2013-09-27

203

Differentiating High-Functioning Autism and Social Phobia  

ERIC Educational Resources Information Center

Both high-functioning autism (HFA) and social phobia (SP) involve profound social interaction deficits. Although these disorders share some similar symptoms, they are conceptualized as distinct. Because both HFA and SP are defined behaviorally, the degree of overlap between the two disorders may result in misinterpretation of symptoms. However,…

Tyson, Katherine E.; Cruess, Dean G.

2012-01-01

204

MafB/c-Maf deficiency enables self-renewal of differentiated functional macrophages.  

PubMed

In metazoan organisms, terminal differentiation is generally tightly linked to cell cycle exit, whereas the undifferentiated state of pluripotent stem cells is associated with unlimited self-renewal. Here, we report that combined deficiency for the transcription factors MafB and c-Maf enables extended expansion of mature monocytes and macrophages in culture without loss of differentiated phenotype and function. Upon transplantation, the expanded cells are nontumorigenic and contribute to functional macrophage populations in vivo. Small hairpin RNA inactivation shows that continuous proliferation of MafB/c-Maf deficient macrophages requires concomitant up-regulation of two pluripotent stem cell-inducing factors, KLF4 and c-Myc. Our results indicate that MafB/c-MafB deficiency renders self-renewal compatible with terminal differentiation. It thus appears possible to amplify functional differentiated cells without malignant transformation or stem cell intermediates. PMID:19892988

Aziz, Athar; Soucie, Erinn; Sarrazin, Sandrine; Sieweke, Michael H

2009-11-01

205

Differentiation and functional regulation of human fetal NK cells.  

PubMed

The human fetal immune system is naturally exposed to maternal allogeneic cells, maternal antibodies, and pathogens. As such, it is faced with a considerable challenge with respect to the balance between immune reactivity and tolerance. Here, we show that fetal natural killer (NK) cells differentiate early in utero and are highly responsive to cytokines and antibody-mediated stimulation but respond poorly to HLA class I-negative target cells. Strikingly, expression of killer-cell immunoglobulin-like receptors (KIRs) did not educate fetal NK cells but rendered them hyporesponsive to target cells lacking HLA class I. In addition, fetal NK cells were highly susceptible to TGF-?-mediated suppression, and blocking of TGF-? signaling enhanced fetal NK cell responses to target cells. Our data demonstrate that KIR-mediated hyporesponsiveness and TGF-?-mediated suppression are major factors determining human fetal NK cell hyporesponsiveness to HLA class I-negative target cells and provide a potential mechanism for fetal-maternal tolerance in utero. Finally, our results provide a basis for understanding the role of fetal NK cells in pregnancy complications in which NK cells could be involved, for example, during in utero infections and anti-RhD-induced fetal anemia. PMID:23945237

Ivarsson, Martin A; Loh, Liyen; Marquardt, Nicole; Kekäläinen, Eliisa; Berglin, Lena; Björkström, Niklas K; Westgren, Magnus; Nixon, Douglas F; Michaëlsson, Jakob

2013-09-01

206

An accessory flexor digitorum longus muscle.  

PubMed

An accessory flexor digitorum longus muscle (M. flexor digitorum longus accessorius) in a 60-year-old male cadaver was encountered during routine dissections in our laboratory. The muscle originated from the deep transverse fascia of the leg, covering flexor digitorum longus, flexor hallucis longus, and tibialis posterior muscles, and additionally from some fibres of these muscles. After the tendon of the muscle passed behind the medial malleolus, it inserted into the tendon of the flexor digitorum longus muscle where the latter separated into four digital tendons. PMID:8273449

Yüksel, M; Ondero?lu, S; Yener, N; Yüksel, E

1993-01-01

207

Differential subcellular localization of functionally divergent survivin splice variants  

Microsoft Academic Search

Survivin is an inhibitor of apoptosis protein (IAP) that is markedly overexpressed in most cancers. We identified two novel functionally divergent splice variants, i.e. non-antiapoptotic survivin-2B and antiapoptotic survivin-?Ex3. Because survivin-2B might be a naturally occurring antagonist of antiapoptotic survivin variants, we analyzed the subcellular distribution of these proteins. PSORT II analysis predicted a preferential cytoplasmic localization of survivin and

C Mahotka; J Liebmann; M Wenzel; C V Suschek; M Schmitt; H E Gabbert; C D Gerharz

2002-01-01

208

Differential Lipid Dependence of the Function of Bacterial Sodium Channels  

PubMed Central

The lipid bilayer is important for maintaining the integrity of cellular compartments and plays a vital role in providing the hydrophobic and charged interactions necessary for membrane protein structure, conformational flexibility and function. To directly assess the lipid dependence of activity for voltage-gated sodium channels, we compared the activity of three bacterial sodium channel homologues (NaChBac, NavMs, and NavSp) by cumulative 22Na+ uptake into proteoliposomes containing a 3?1 ratio of 1-palmitoyl 2-oleoyl phosphatidylethanolamine and different “guest” glycerophospholipids. We observed a unique lipid profile for each channel tested. NavMs and NavSp showed strong preference for different negatively-charged lipids (phosphatidylinositol and phosphatidylglycerol, respectively), whilst NaChBac exhibited a more modest variation with lipid type. To investigate the molecular bases of these differences we used synchrotron radiation circular dichroism spectroscopy to compare structures in liposomes of different composition, and molecular modeling and electrostatics calculations to rationalize the functional differences seen. We then examined pore-only constructs (with voltage sensor subdomains removed) and found that in these channels the lipid specificity was drastically reduced, suggesting that the specific lipid influences on voltage-gated sodium channels arise primarily from their abilities to interact with the voltage-sensing subdomains.

D'Avanzo, Nazzareno; McCusker, Emily C.; Powl, Andrew M.; Miles, Andrew J.; Nichols, Colin G.; Wallace, B. A.

2013-01-01

209

Reviewing prescription spending and accessory usage.  

PubMed

This article aims to explore the role of the stoma nurse specialist in the community and how recent initiatives within the NHS have impacted on the roles in stoma care to react to the rising prescription costs in the specialty. The article will explore how the stoma care nurse conducted her prescription reviews within her own clinical commissioning group (CCG). The findings of the reviews will be highlighted by a small case history and a mini audit that reveals that some stoma patients may be using their stoma care accessories inappropriately, which may contribute to the rise in stoma prescription spending. To prevent the incorrect use of stoma appliances it may necessitate an annual review of ostomates (individuals who have a stoma), as the author's reviews revealed that inappropriate usage was particularly commonplace when a patient may have not been reviewed by a stoma care specialist for some considerable amount of time. Initial education of the ostomate and ongoing education of how stoma products work is essential to prevent the misuse of stoma appliances, particularly accessories, as the reviews revealed that often patients were not always aware of how their products worked in practice. PMID:24642774

Oxenham, Julie

210

The method of local linear approximation in the theory of nonlinear functional-differential equations  

SciTech Connect

Conditions for the existence of solutions to the nonlinear functional-differential equation (d{sup m}x(t))/dt{sup m} + (fx)(t)=h(t), t element of R in the space of functions bounded on the axes are obtained by using local linear approximation to the operator F. Bibliography: 21 items.

Slyusarchuk, Vasilii E [Ukranian State Academy of Water Economy (Ukraine)

2010-10-06

211

A Generalized Logistic Regression Procedure to Detect Differential Item Functioning among Multiple Groups  

ERIC Educational Resources Information Center

We present an extension of the logistic regression procedure to identify dichotomous differential item functioning (DIF) in the presence of more than two groups of respondents. Starting from the usual framework of a single focal group, we propose a general approach to estimate the item response functions in each group and to test for the presence…

Magis, David; Raiche, Gilles; Beland, Sebastien; Gerard, Paul

2011-01-01

212

Detection of Gender-Based Differential Item Functioning in a Mathematics Performance Assessment.  

ERIC Educational Resources Information Center

This study used three different differential item functioning (DIF) procedures to examine the extent to which items in a mathematics performance assessment functioned differently for matched gender groups. In addition to examining the appropriateness of individual items in terms of DIF with respect to gender, an attempt was made to identify…

Wang, Ning; Lane, Suzanne

213

Children with High-Functioning Autism and Asperger's Syndrome: Can We Differentiate Their Cognitive Profiles?  

ERIC Educational Resources Information Center

The aim of this study was to investigate whether children with high-functioning autism (HFA) and Asperger's syndrome (AS) can be differentiated from each other and from typically developing children on their cognitive profiles. The present study included a total of 45 participants: children with autism (high-functioning autism or Asperger's…

Planche, Pascale; Lemonnier, Eric

2012-01-01

214

Parental Divorce and Family Functioning: Effects on Differentiation Levels of Young Adults.  

ERIC Educational Resources Information Center

Study examines the effect of parental divorce and various dimensions of functioning in the family of origin on young adult development. Results indicate that parental divorce and family functioning significantly affect differentiation levels of young adults. Implications of the results for counselors and future researchers are provided. (Contains…

Johnson, Patrick; Throngren, Jill M.; Smith, Adina J.

2001-01-01

215

Differential Item Functioning Analysis of the Mental, Emotional, and Bodily Toughness Inventory  

ERIC Educational Resources Information Center

In this study the authors used differential item functioning analysis to examine if there were items in the Mental, Emotional, and Bodily Toughness Inventory functioning differently across gender and athletic membership. A total of 444 male (56.3%) and female (43.7%) participants (30.9% athletes and 69.1% non-athletes) responded to the Mental,…

Gao, Yong; Mack, Mick G.; Ragan, Moira A.; Ragan, Brian

2012-01-01

216

Systematically differentiating functions for alternatively spliced isoforms through integrating RNA-seq data.  

PubMed

Integrating large-scale functional genomic data has significantly accelerated our understanding of gene functions. However, no algorithm has been developed to differentiate functions for isoforms of the same gene using high-throughput genomic data. This is because standard supervised learning requires 'ground-truth' functional annotations, which are lacking at the isoform level. To address this challenge, we developed a generic framework that interrogates public RNA-seq data at the transcript level to differentiate functions for alternatively spliced isoforms. For a specific function, our algorithm identifies the 'responsible' isoform(s) of a gene and generates classifying models at the isoform level instead of at the gene level. Through cross-validation, we demonstrated that our algorithm is effective in assigning functions to genes, especially the ones with multiple isoforms, and robust to gene expression levels and removal of homologous gene pairs. We identified genes in the mouse whose isoforms are predicted to have disparate functionalities and experimentally validated the 'responsible' isoforms using data from mammary tissue. With protein structure modeling and experimental evidence, we further validated the predicted isoform functional differences for the genes Cdkn2a and Anxa6. Our generic framework is the first to predict and differentiate functions for alternatively spliced isoforms, instead of genes, using genomic data. It is extendable to any base machine learner and other species with alternatively spliced isoforms, and shifts the current gene-centered function prediction to isoform-level predictions. PMID:24244129

Eksi, Ridvan; Li, Hong-Dong; Menon, Rajasree; Wen, Yuchen; Omenn, Gilbert S; Kretzler, Matthias; Guan, Yuanfang

2013-11-01

217

The effect of water on accessory phase solubility in subaluminous and peralkaline granitic melts  

NASA Astrophysics Data System (ADS)

The solubilities of columbite, tantalite, wolframite, rutile, zircon and hafnon were determined as a function of the water contents in peralkaline and subaluminous granite melts. All experiments were conducted at 1035 °C and 2 kbar and the water contents of the melts ranged from nominally dry to approximately 6 wt.% H 2O. Accessory phase solubilities are not affected by the water content of the peralkaline melt. By contrast, solubilities are affected by the water content of the subaluminous melt, where the solubilities of all the accessory phases examined increase with the water content of the melt, up to ˜2 wt.% H 2O. At higher water contents, solubilities are nearly constant. It can be concluded that water is not an important control of accessory phase solubility, although the water content will affect diffusivities of components in the melt, thus whether or not accessory phases will be present as restite material. The solubility behaviour in the subaluminous and peralkaline melts supports previous spectroscopic studies, which have observed differences in the coordination of high field strength elements in dry vs. wet subaluminous granitic glasses, but not for peralkaline granitic glasses. Lastly, the fact that wolframite solubility increases with increasing water content in the subaluminous melt suggests that tungsten dissolved as a hexavalent species.

Linnen, Robert L.

2005-03-01

218

Diverse Broad-Host-Range Plasmids from Freshwater Carry Few Accessory Genes  

PubMed Central

Broad-host-range self-transferable plasmids are known to facilitate bacterial adaptation by spreading genes between phylogenetically distinct hosts. These plasmids typically have a conserved backbone region and a variable accessory region that encodes host-beneficial traits. We do not know, however, how well plasmids that do not encode accessory functions can survive in nature. The goal of this study was to characterize the backbone and accessory gene content of plasmids that were captured from freshwater sources without selecting for a particular phenotype or cultivating their host. To do this, triparental matings were used such that the only required phenotype was the plasmid's ability to mobilize a nonconjugative plasmid. Based on complete genome sequences of 10 plasmids, only 5 carried identifiable accessory gene regions, and none carried antibiotic resistance genes. The plasmids belong to four known incompatibility groups (IncN, IncP-1, IncU, and IncW) and two potentially new groups. Eight of the plasmids were shown to have a broad host range, being able to transfer into alpha-, beta-, and gammaproteobacteria. Because of the absence of antibiotic resistance genes, we resampled one of the sites and compared the proportion of captured plasmids that conferred antibiotic resistance to their hosts with the proportion of such plasmids captured from the effluent of a local wastewater treatment plant. Few of the captured plasmids from either site encoded antibiotic resistance. A high diversity of plasmids that encode no or unknown accessory functions is thus readily found in freshwater habitats. The question remains how the plasmids persist in these microbial communities.

Sen, Diya; Yano, Hirokazu; Bauer, Matthew L.; Rogers, Linda M.; Van der Auwera, Geraldine A.

2013-01-01

219

p120-catenin and ?-catenin differentially regulate cadherin adhesive function  

PubMed Central

Vascular endothelial (VE)-cadherin, the major adherens junction adhesion molecule in endothelial cells, interacts with p120-catenin and ?-catenin through its cytoplasmic tail. However, the specific functional contributions of the catenins to the establishment of strong adhesion are not fully understood. Here we use bioengineering approaches to identify the roles of cadherin–catenin interactions in promoting strong cellular adhesion and the ability of the cells to spread on an adhesive surface. Our results demonstrate that the domain of VE-cadherin that binds to ?-catenin is required for the establishment of strong steady-state adhesion strength. Surprisingly, p120 binding to the cadherin tail had no effect on the strength of adhesion when the available adhesive area was limited. Instead, the binding of VE-cadherin to p120 regulates adhesive contact area in a Rac1-dependent manner. These findings reveal that p120 and ?-catenin have distinct but complementary roles in strengthening cadherin-mediated adhesion.

Oas, Rebecca G.; Nanes, Benjamin A.; Esimai, Chimdimnma C.; Vincent, Peter A.; Garcia, Andres J.; Kowalczyk, Andrew P.

2013-01-01

220

Structural and functional differentiation of sinusoidal endothelial cells during liver organogenesis in humans.  

PubMed

During fetal life, human liver sinusoids, which differentiate between 4 and 12 weeks of gestation from capillaries of the septum transversum, must support an important hematopoietic function and acquire the structural and functional characteristics of adult sinusoids. To gain insight into their differentiation process, we studied the expression of (1) markers of continuous endothelia, absent from adult sinusoidal endothelial cells (PECAM-1, CD34, and 1F10); (2) functional markers of adult sinusoidal endothelial calls (CD4, 1CAM-1, CD32, and CD14); and (3) extracellular matrix components (laminin, tenascin, fibronectin, and thrombospondin) in 37 fetuses of different gestational ages. We identified two successive differentiation events. (1) An early structural differentiation, occurring from 5 to 12 weeks of gestation, was characterized by the loss of continuous endothelial cell markers and a reduction in the perisinusoidal amount of laminin and in the deposition of tenascin, fibronectin, and thrombospondin; at the end of this process, fetal liver sinusoids present structural characteristics comparable to those of the sinuses in adult hematopoietic bone marrow. (2) A later functional differentiation was characterized by the acquisition of the markers of adult sinusoidal endothelial cells, initiating at 10 weeks of gestation and completed by 20 weeks of gestation; this process likely contributes to adapt liver sinusoids to the specific functions of the adult hepatic tissue. PMID:8639825

Couvelard, A; Scoazec, J Y; Dauge, M C; Bringuier, A F; Potet, F; Feldmann, G

1996-06-01

221

Where to Find Hair Loss Accessories and Breast Cancer Products  

MedlinePLUS

Where to Find Hair Loss Accessories and Breast Cancer Products Cancer treatments can cause major changes in the way you look – like surgery that ... to find a retailer near you. Wigs and hair loss accessories This is a list of retailers that ...

222

21 CFR 872.6250 - Dental chair and accessories.  

Code of Federal Regulations, 2010 CFR

...872.6250 Dental chair and accessories. ...Identification. A dental chair and accessories is a...AC-powered, in which a patient sits. The device is...to properly position a patient to perform dental procedures... Class I. The dental chair without the...

2010-04-01

223

21 CFR 872.6250 - Dental chair and accessories.  

Code of Federal Regulations, 2010 CFR

...872.6250 Dental chair and accessories. ...Identification. A dental chair and accessories is a...AC-powered, in which a patient sits. The device is...to properly position a patient to perform dental procedures... Class I. The dental chair without the...

2009-04-01

224

21 CFR 872.6250 - Dental chair and accessories.  

Code of Federal Regulations, 2013 CFR

...872.6250 Dental chair and accessories. ...Identification. A dental chair and accessories is a...AC-powered, in which a patient sits. The device is...to properly position a patient to perform dental procedures... Class I. The dental chair without the...

2013-04-01

225

On Nonseparated Three-Point Boundary Value Problems for Linear Functional Differential Equations  

Microsoft Academic Search

For a system of linear functional differential equations, we consider a\\u000athree-point problem with nonseparated boundary conditions determined by singular\\u000amatrices. We show that, to investigate such a problem, it is often useful to\\u000areduce it to a parametric family of two-point boundary value problems for a\\u000asuitably perturbed differential system. The auxiliary parametrised two-point\\u000aproblems are then studied by

A. Rontó; M. Rontó

2011-01-01

226

The functional expression of calcium-sensing receptor in the differentiated THP1 cells  

Microsoft Academic Search

The expression and function of calcium-sensing receptor (CaSR) in differentiated THP-1 (human acute monocytic leukemia cell\\u000a line) cells are unknown currently. This study investigated above-mentioned issues using TRAP staining, immunofluorescence\\u000a staining, Western blotting, ELISA, and Laser Confocal Scanning Microscopy techniques. We found that CaSR protein was expressed,\\u000a and mainly located in the membrane and cytoplasm in differentiated THP-1 cells. Elevated

Yu-hui Xi; Hong-zhu Li; Wei-hua Zhang; Li-na Wang; Li Zhang; Yan Lin; Shu-zhi Bai; Hong-xia Li; Ling-yun Wu; Rui Wang; Chang-qing Xu

2010-01-01

227

In vitro differentiation of rat embryonic stem cells into functional cardiomyocytes.  

PubMed

The recent breakthrough in the generation of rat embryonic stem cells (rESCs) opens the door to application of gene targeting to create models for the study of human diseases. In addition, the in vitro differentiation system from rESCs into derivatives of three germ layers will serve as a powerful tool and resource for the investigation of mammalian development, cell function, tissue repair, and drug discovery. However, these uses have been limited by the difficulty of in vitro differentiation. The aims of this study were to establish an in vitro differentiation system from rESCs and to investigate whether rESCs are capable of forming terminal-differentiated cardiomyocytes. Using newly established rESCs, we found that embryoid body (EB)-based method used in mouse ESC (mESC) differentiation failed to work for the serum-free cultivated rESCs. We then developed a protocol by combination of three chemical inhibitors and feeder-conditioned medium. Under this condition, rESCs formed EBs, propagated and differentiated into three embryonic germ layers. Moreover, rESC-formed EBs could differentiate into spontaneously beating cardiomyocytes after plating. Analyses of molecular, structural, and functional properties revealed that rESC-derived cardiomyocytes were similar to those derived from fetal rat hearts and mESCs. In conclusion, we successfully developed an in vitro differentiation system for rESCs through which functional myocytes were generated and displayed phenotypes of rat fetal cardiomyocytes. This unique cellular system will provide a new approach to study the early development and cardiac function, and serve as an important tool in pharmacological testing and cell therapy. PMID:21423272

Cao, Nan; Liao, Jing; Liu, Zumei; Zhu, Wenmin; Wang, Jia; Liu, Lijun; Yu, Lili; Xu, Ping; Cui, Chun; Xiao, Lei; Yang, Huang-Tian

2011-09-01

228

Three differentially expressed S-adenosylmethionine synthetases from Catharanthus roseus: molecular and functional characterization  

Microsoft Academic Search

We describe the molecular and functional characterization of three closely related S-adenosyl-L-methionine synthetase (SAMS) isoenzymes from Catharanthus roseus (Madagascar periwinkle). The genes are differentially expressed in cell cultures during growth of the culture and after application of various stresses (elicitor, nutritional down-shift, increased NaCl). Seedlings revealed organ-specific expression and differential gene regulation after salt stress. A relationship analysis indicated that

Gudrun Schröder; Johannes Eichel; Sabine Breinig; Joachim Schröder

1997-01-01

229

Functional differentiation of chitin synthases in Yarrowia lipolytica.  

PubMed

In this study, we identified seven chitin synthase-encoding genes in the genome of the dimorphic yeast Yarrowia lipolytica. Three encoded chitin synthases with myosin motor-like domains at their N-termini, and we designated these CSM1 to CSM3, whereas four were identified as CHS1 to CHS4. To investigate the functions of these seven genes, we constructed and characterized their deletion mutants. The chs2? mutant formed chained cells in which daughter cells were connected with mother cells and had abnormally thick septa at the bud neck. The chs4? mutant showed remarkably reduced chitin content in its cell wall. The chs2?, csm1?, and csm2? mutants were found to be highly sensitive to chitin binding dyes, calcofluor white (CFW) and Congo red, whereas the chs4? mutant was resistant to CFW. These results suggest that Chs2 and Chs4 play major roles in septum formation and cell wall chitin synthesis respectively, whereas Csm1 and Csm2 are involved in the maintenance of cell wall architecture and/or cell wall integrity. The populations of filamentous cells, a type of cell population that are defined by the lengths of the cellular long and short axes, decreased in the chs3? mutant, suggesting that Chs3 is involved in cellular morphogenesis. PMID:23748777

Sheng, Wei; Yamashita, Shuichi; Ohta, Akinori; Horiuchi, Hiroyuki

2013-01-01

230

Galectin-3 drives oligodendrocyte differentiation to control myelin integrity and function  

PubMed Central

Galectins control critical pathophysiological processes, including the progression and resolution of central nervous system (CNS) inflammation. In spite of considerable progress in dissecting their role within lymphoid organs, their functions within the inflamed CNS remain elusive. Here, we investigated the role of galectin–glycan interactions in the control of oligodendrocyte (OLG) differentiation, myelin integrity and function. Both galectin-1 and -3 were abundant in astrocytes and microglia. Although galectin-1 was abundant in immature but not in differentiated OLGs, galectin-3 was upregulated during OLG differentiation. Biochemical analysis revealed increased activity of metalloproteinases responsible for cleaving galectin-3 during OLG differentiation and modulating its biological activity. Exposure to galectin-3 promoted OLG differentiation in a dose- and carbohydrate-dependent fashion consistent with the ‘glycosylation signature' of immature versus differentiated OLG. Accordingly, conditioned media from galectin-3-expressing, but not galectin-3-deficient (Lgals3?/?) microglia, successfully promoted OLG differentiation. Supporting these findings, morphometric analysis showed a significant decrease in the frequency of myelinated axons, myelin turns (lamellae) and g-ratio in the corpus callosum and striatum of Lgals3?/? compared with wild-type (WT) mice. Moreover, the myelin structure was loosely wrapped around the axons and less smooth in Lgals3?/? mice versus WT mice. Behavior analysis revealed decreased anxiety in Lgals3?/? mice similar to that observed during early demyelination induced by cuprizone intoxication. Finally, commitment toward the oligodendroglial fate was favored in neurospheres isolated from WT but not Lgals3?/? mice. Hence, glial-derived galectin-3, but not galectin-1, promotes OLG differentiation, thus contributing to myelin integrity and function with critical implications in the recovery of inflammatory demyelinating disorders.

Pasquini, L A; Millet, V; Hoyos, H C; Giannoni, J P; Croci, D O; Marder, M; Liu, F T; Rabinovich, G A; Pasquini, J M

2011-01-01

231

GO-Diff: Mining functional differentiation between EST-based transcriptomes  

PubMed Central

Background Large-scale sequencing efforts produced millions of Expressed Sequence Tags (ESTs) collectively representing differentiated biochemical and functional states. Analysis of these EST libraries reveals differential gene expressions, and therefore EST data sets constitute valuable resources for comparative transcriptomics. To translate differentially expressed genes into a better understanding of the underlying biological phenomena, existing microarray analysis approaches usually involve the integration of gene expression with Gene Ontology (GO) databases to derive comparable functional profiles. However, methods are not available yet to process EST-derived transcription maps to enable GO-based global functional profiling for comparative transcriptomics in a high throughput manner. Results Here we present GO-Diff, a GO-based functional profiling approach towards high throughput EST-based gene expression analysis and comparative transcriptomics. Utilizing holistic gene expression information, the software converts EST frequencies into EST Coverage Ratios of GO Terms. The ratios are then tested for statistical significances to uncover differentially represented GO terms between the compared transcriptomes, and functional differences are thus inferred. We demonstrated the validity and the utility of this software by identifying differentially represented GO terms in three application cases: intra-species comparison; meta-analysis to test a specific hypothesis; inter-species comparison. GO-Diff findings were consistent with previous knowledge and provided new clues for further discoveries. A comprehensive test on the GO-Diff results using series of comparisons between EST libraries of human and mouse tissues showed acceptable levels of consistency: 61% for human-human; 69% for mouse-mouse; 47% for human-mouse. Conclusion GO-Diff is the first software integrating EST profiles with GO knowledge databases to mine functional differentiation between biological systems, e.g. tissues of the same species or the same tissue cross species. With rapid accumulation of EST resources in the public domain and expanding sequencing effort in individual laboratories, GO-Diff is useful as a screening tool before undertaking serious expression studies.

Chen, Zuozhou; Wang, Weilin; Ling, Xuefeng Bruce; Liu, Jane Jijun; Chen, Liangbiao

2006-01-01

232

Accessory mental foramen: a rare anatomical finding  

PubMed Central

Accessory mental foramen (AMF) is a rare anatomical variation with a prevalence ranging from 1.4 to 10%. Even so, in order to avoid neurovascular complications, particular attention should be paid to the possible occurrence of one or more AMF during surgical procedures involving the mandible. Careful surgical dissection should be performed in the region so that the presence of AMF can be detected and the occurrence of a neurosensory disturbance or haemorrhage can be avoided. Although this anatomical variation is rare, it should be kept in mind that an AMF may exist. Trigeminal neuralgia was diagnosed. On the basis of diagnostic test results, peripheral neurectomy of mental nerve was planned. Failure to do neurectomy of mental nerve branch in the reported case, coming out from AMF, would have resulted in recurrence of pain and eventually failure of the procedure.

Thakur, Gagan; Thomas, Shaji; Thayil, Sumeeth Cyriac; Nair, Preeti P

2011-01-01

233

[Juxtabulbar neurinoma of the spinal accessory nerve].  

PubMed

A 27-year-old woman presented with right spinal accessory juxtabulbar schwannoma, associated with hydrocephalus. The only specific clinical symptom was long-standing weakness of the right trapezius. C.T. scan evoked a cerebellar tumor, whilst the jugular foramen appeared normal. Vertebral angiography was not decisive. M.R.I. suggested an extra-axial tumor. Post-operative evolution was entirely favourable. Schwannomas of the 9th, 10th and 11th cranial nerves are generally located at the level of the jugular foramen but can also be observed along the extracranial path of these nerves. An intracranial paramedial, or so-called "intracisternal" localization is rare and is best diagnosed by magnetic resonance imaging. PMID:1461336

Fransen, P; Dooms, G; Mathurin, P; Thauvoy, C; Stroobandt, G

1992-01-01

234

Human embryonic stem cells differentiate into functional renal proximal tubular-like cells.  

PubMed

Renal cells are used in basic research, disease models, tissue engineering, drug screening, and in vitro toxicology. In order to provide a reliable source of human renal cells, we developed a protocol for the differentiation of human embryonic stem cells into renal epithelial cells. The differentiated stem cells expressed markers characteristic of renal proximal tubular cells and their precursors, whereas markers of other renal cell types were not expressed or expressed at low levels. Marker expression patterns of these differentiated stem cells and in vitro cultivated primary human renal proximal tubular cells were comparable. The differentiated stem cells showed morphological and functional characteristics of renal proximal tubular cells, and generated tubular structures in vitro and in vivo. In addition, the differentiated stem cells contributed in organ cultures for the formation of simple epithelia in the kidney cortex. Bioreactor experiments showed that these cells retained their functional characteristics under conditions as applied in bioartificial kidneys. Thus, our results show that human embryonic stem cells can differentiate into renal proximal tubular-like cells. Our approach would provide a source for human renal proximal tubular cells that are not affected by problems associated with immortalized cell lines or primary cells. PMID:23389418

Narayanan, Karthikeyan; Schumacher, Karl M; Tasnim, Farah; Kandasamy, Karthikeyan; Schumacher, Annegret; Ni, Ming; Gao, Shujun; Gopalan, Began; Zink, Daniele; Ying, Jackie Y

2013-04-01

235

IRF6 is a mediator of Notch pro-differentiation and tumour suppressive function in keratinocytes  

PubMed Central

While the pro-differentiation and tumour suppressive functions of Notch signalling in keratinocytes are well established, the underlying mechanisms remain poorly understood. We report here that interferon regulatory factor 6 (IRF6), an IRF family member with an essential role in epidermal development, is induced in differentiation through a Notch-dependent mechanism and is a primary Notch target in keratinocytes and keratinocyte-derived SCC cells. Increased IRF6 expression contributes to the impact of Notch activation on growth/differentiation-related genes, while it is not required for induction of ‘canonical' Notch targets like p21WAF1/Cip1, Hes1 and Hey1. Down-modulation of IRF6 counteracts differentiation of primary human keratinocytes in vitro and in vivo, promoting ras-induced tumour formation. The clinical relevance of these findings is illustrated by the strikingly opposite pattern of expression of Notch1 and IRF6 versus epidermal growth factor receptor in a cohort of clinical SCCs, as a function of their grade of differentiation. Thus, IRF6 is a primary Notch target in keratinocytes, which contributes to the role of this pathway in differentiation and tumour suppression.

Restivo, Gaetana; Nguyen, Bach-Cuc; Dziunycz, Piotr; Ristorcelli, Elodie; Ryan, Russell J H; Ozuysal, Ozden Yalcin; Di Piazza, Matteo; Radtke, Freddy; Dixon, Michael J; Hofbauer, Gunther F L; Lefort, Karine; Dotto, G Paolo

2011-01-01

236

Quantitative neuroproteomics: classical and novel tools for studying neural differentiation and function.  

PubMed

Mechanisms underlying neural stem cell proliferation, differentiation and maturation play a critical role in the formation and wiring of neuronal connections. This process involves the activation of multiple serial events, which guide the undifferentiated cells to different lineages via distinctive developmental programs, forming neuronal circuits and thus shaping the adult nervous system. Furthermore, alterations within these strictly regulated pathways can lead to severe neurological and psychiatric diseases. In this framework, the investigation of the high dynamic protein expression changes and other factors affecting protein functions, for example post-translational modifications, the alterations of protein interaction networks, is of pivotal importance for the understanding of the molecular mechanisms responsible for cell differentiation. More recently, proteomic studies in neuroscience ("neuroproteomics") are receiving increased interest for the primary understanding of the regulatory networks underlying neuronal differentiation processes. Besides the classical two-dimensional-based proteomic strategies, the emerging platforms for LC-MS shotgun proteomic analysis hold great promise in unraveling the molecular basis of neural stem cell differentiation. In this review, recent advancements in label-free LC-MS quantitative neuroproteomics are highlighted as a new tool for the study of neural differentiation and functions, in comparison to mass spectrometry-based labeling approaches. The more commonly used protein profiling strategies and model systems for the analysis of neural differentiation are also discussed, along with the challenging proteomic approaches aimed to analyze the nervous system-specific organelles, the neural cells secretome and the specific protein interaction networks. PMID:20352529

Colucci-D'Amato, Luca; Farina, Annarita; Vissers, Johannes P C; Chambery, Angela

2011-03-01

237

FGF-2 controls the differentiation of resident cardiac precursors into functional cardiomyocytes  

PubMed Central

Recent evidence suggests that the heart possesses a greater regeneration capacity than previously thought. In the present study, we isolated undifferentiated precursors from the cardiac nonmyocyte cell population of neonatal hearts, expanded them in culture, and induced them to differentiate into functional cardiomyocytes. These cardiac precursors appear to express stem cell antigen–1 and demonstrate characteristics of multipotent precursors of mesodermal origin. Following infusion into normal recipients, these cells home to the heart and participate in physiological and pathophysiological cardiac remodeling. Cardiogenic differentiation in vitro and in vivo depends on FGF-2. Interestingly, this factor does not control the number of precursors but regulates the differentiation process. These findings suggest that, besides its angiogenic actions, FGF-2 could be used in vivo to facilitate the mobilization and differentiation of resident cardiac precursors in the treatment of cardiac diseases.

Rosenblatt-Velin, Nathalie; Lepore, Mario G.; Cartoni, Cristina; Beermann, Friedrich; Pedrazzini, Thierry

2005-01-01

238

Oxygen tension modulates differentiation and primary macrophage functions in the human monocytic THP-1 cell line.  

PubMed

The human THP-1 cell line is widely used as an in vitro model system for studying macrophage differentiation and function. Conventional culture conditions for these cells consist of ambient oxygen pressure (?20% v/v) and medium supplemented with the thiol 2-mercaptoethanol (2-ME) and serum. In consideration of the redox activities of O? and 2-ME, and the extensive experimental evidence supporting a role for reactive oxygen species (ROS) in the differentiation and function of macrophages, we addressed the question of whether culturing THP-1 cells under a more physiologically relevant oxygen tension (5% O?) in the absence of 2-ME and serum would alter THP-1 cell physiology. Comparisons of cultures maintained in 18% O?versus 5% O? indicated that reducing oxygen tension had no effect on the proliferation of undifferentiated THP-1 cells. However, decreasing the oxygen tension to 5% O? significantly increased the rate of phorbol ester-induced differentiation of THP-1 cells into macrophage-like cells as well as the metabolic activity of both undifferentiated and PMA-differentiated THP-1 cells. Removal of both 2-ME and serum from the medium decreased the proliferation of undifferentiated THP-1 cells but increased metabolic activity and the rate of differentiation under either oxygen tension. In differentiated THP-1 cells, lowering the oxygen tension to 5% O? decreased phagocytic activity, the constitutive release of ?-hexosaminidase and LPS-induced NF-?B activation but enhanced LPS-stimulated release of cytokines. Collectively, these data demonstrate that oxygen tension influences THP-1 cell differentiation and primary macrophage functions, and suggest that culturing these cells under tightly regulated oxygen tension in the absence of exogenous reducing agent and serum is likely to provide a physiologically relevant baseline from which to study the role of the local redox environment in regulating THP-1 cell physiology. PMID:23355903

Grodzki, Ana Cristina G; Giulivi, Cecilia; Lein, Pamela J

2013-01-01

239

Oxygen Tension Modulates Differentiation and Primary Macrophage Functions in the Human Monocytic THP-1 Cell Line  

PubMed Central

The human THP-1 cell line is widely used as an in vitro model system for studying macrophage differentiation and function. Conventional culture conditions for these cells consist of ambient oxygen pressure (?20% v/v) and medium supplemented with the thiol 2-mercaptoethanol (2-ME) and serum. In consideration of the redox activities of O2 and 2-ME, and the extensive experimental evidence supporting a role for reactive oxygen species (ROS) in the differentiation and function of macrophages, we addressed the question of whether culturing THP-1 cells under a more physiologically relevant oxygen tension (5% O2) in the absence of 2-ME and serum would alter THP-1 cell physiology. Comparisons of cultures maintained in 18% O2 versus 5% O2 indicated that reducing oxygen tension had no effect on the proliferation of undifferentiated THP-1 cells. However, decreasing the oxygen tension to 5% O2 significantly increased the rate of phorbol ester-induced differentiation of THP-1 cells into macrophage-like cells as well as the metabolic activity of both undifferentiated and PMA-differentiated THP-1 cells. Removal of both 2-ME and serum from the medium decreased the proliferation of undifferentiated THP-1 cells but increased metabolic activity and the rate of differentiation under either oxygen tension. In differentiated THP-1 cells, lowering the oxygen tension to 5% O2 decreased phagocytic activity, the constitutive release of ?-hexosaminidase and LPS-induced NF-?B activation but enhanced LPS-stimulated release of cytokines. Collectively, these data demonstrate that oxygen tension influences THP-1 cell differentiation and primary macrophage functions, and suggest that culturing these cells under tightly regulated oxygen tension in the absence of exogenous reducing agent and serum is likely to provide a physiologically relevant baseline from which to study the role of the local redox environment in regulating THP-1 cell physiology.

Grodzki, Ana Cristina G.; Giulivi, Cecilia; Lein, Pamela J.

2013-01-01

240

CD4+ T helper 2 cells - microbial triggers, differentiation requirements and effector functions  

PubMed Central

Over the past 10 years we have made great strides in our understanding of T helper cell differentiation, expansion and effector functions. Within the context of T helper type 2 (Th2) cell development, novel innate-like cells with the capacity to secrete large amounts of interleukin-5 (IL-5), IL-13 and IL-9 as well as IL-4-producing and antigen-processing basophils have (re)-emerged onto the type 2 scene. To what extent these new players influence ??+ CD4+ Th2 cell differentiation is discussed throughout this appraisal of the current literature. We highlight the unique features of Th2 cell development, highlighting the three necessary signals, T-cell receptor ligation, co-stimulation and cytokine receptor ligation. Finally, putting these into context, microbial and allergenic properties that trigger Th2 cell differentiation and how these influence Th2 effector function are discussed and questioned.

Okoye, Isobel S; Wilson, Mark S

2011-01-01

241

Staphylococcus aureus and Staphylococcus epidermidis peptide pheromones produced by the accessory gene regulator agr system  

Microsoft Academic Search

The accessory gene regulator (agr) system of staphylococci regulates the expression of virulence factors in response to cell density. The extracellular signaling molecule encoded by this system is a thiolactone-containing pheromone peptide whose primary sequence varies among staphylococcal strains. A post-translational modification of the peptide is believed to be carried out by an enzyme with a novel function, AgrB. Staphylococcal

Michael Otto

2001-01-01

242

Noninvasive electrocardiomapping facilitates previously failed ablation of right appendage diverticulum associated life-threatening accessory pathway.  

PubMed

Combination of structural (CT-scan) and functional (3D electrocardiomapping) imaging methods helped successfully accomplish ablation of a life-threatening manifest accessory pathway in association with a complex right atrial anomaly after previous unsuccessful attempts of endo-epicardial ablation guided by the invasive electroanatomic system in an adolescent female. Such a system has a potential to facilitate the ablation procedure and impact its outcome through accurate localization of the arrhythmogenic substrate. PMID:23252769

Hocini, Mélèze; Shah, Ashok J; Cochet, Hubert; Maury, Philippe; Denis, Arnaud; Haïssaguerre, Michel

2013-05-01

243

Regulation of adult neurogenesis by behavior and age in the accessory olfactory bulb.  

PubMed

The vomeronasal system (VNS) participates in the detection and processing of pheromonal information related to social and sexual behaviors. Within the VNS, two different populations of sensory neurons, with a distinct pattern of distribution, line the epithelium of the vomeronasal organ (VNO) and give rise to segregated sensory projections to the accessory olfactory bulb (AOB). Apical sensory neurons in the VNO project to the anterior AOB (aAOB), while basal neurons project to the posterior AOB (pAOB). In the AOB, the largest population of neurons are inhibitory, the granule and periglomerular cells (GCs and PGs) and remarkably, these neurons are continuously born and functionally integrated in the adult brain, underscoring their role on olfactory function. Here we show that behaviors mediated by the VNS differentially regulate adult neurogenesis across the anterior-posterior axis of the AOB. We used immunohistochemical labeling of newly born cells under different behavioral conditions in mice. Using a resident-intruder aggression paradigm, we found that subordinate mice exhibited increased neurogenesis in the aAOB. In addition, in sexually naive adult females exposed to soiled bedding odorized by adult males, the number of newly born cells was significantly increased in the pAOB; however, neurogenesis was not affected in females exposed to female odors. In addition, we found that at two months of age adult neurogenesis was sexually dimorphic, with male mice exhibiting higher levels of newly born cells than females. Interestingly, adult neurogenesis was greatly reduced with age and this decrease correlated with a decrease in progenitor cells proliferation but not with an increase in cell death in the AOB. These results indicate that the physiological regulation of adult neurogenesis in the AOB by behaviors is both sex and age dependent and suggests an important role of newly born neurons in sex dependent behaviors mediated by the VNS. PMID:21600286

Nunez-Parra, Alexia; Pugh, Victoria; Araneda, Ricardo C

2011-08-01

244

Computing Fukui functions without differentiating with respect to electron number. I. Fundamentals.  

PubMed

By using perturbations in the molecular external potential, the authors deduce the Fukui function from the change in Kohn-Sham orbital energies, avoiding the troublesome differentiation of the density with respect to electron number. Though this paper focuses on the Fukui function, the same general technique can be used to compute the functional derivative of any observable with respect to the external potential. In this paper, the method is used to compute the Fukui function for the beryllium atom and the formaldehyde molecule. The follow-up paper (part II) addresses the problem of computing condensed reactivity indicators. PMID:17581044

Ayers, Paul W; De Proft, Frank; Borgoo, Alex; Geerlings, Paul

2007-06-14

245

Global series solutions of nonlinear differential equations with shocks using Walsh functions  

NASA Astrophysics Data System (ADS)

An orthonormal basis set composed of Walsh functions is used for deriving global solutions (valid over the entire domain) to nonlinear differential equations that include discontinuities. Function gn(x) of the set, a scaled Walsh function in sequency order, is comprised of n piecewise constant values (square waves) across the domain xa?x?xb. Only two square wave lengths are allowed in any function and a new derivation of the basis functions applies a fractal-like algorithm (infinitely self-similar) focused on the distribution of wave lengths. This distribution is determined by a recursive folding algorithm that propagates fundamental symmetries to successive values of n. Functions, including those with discontinuities, may be represented on the domain as a series in gn(x) with no occurrence of a Gibbs phenomenon (ringing) across the discontinuity. A much more powerful, self-mapping characteristic of the series is closure under multiplication - the product of any two Walsh functions is also a Walsh function. This self-mapping characteristic transforms the solution of nonlinear differential equations to the solution of systems of polynomial equations if the original nonlinearities can be represented as products of the dependent variables and the convergence of the series for n?? can be demonstrated. Fundamental operations (reciprocal, integral, derivative) on Walsh function series representations of functions with discontinuities are defined. Examples are presented for solution of the time dependent Burger's equation and for quasi-one-dimensional nozzle flow including a shock.

Gnoffo, Peter A.

2014-02-01

246

Icariin induces mouse embryonic stem cell differentiation into beating functional cardiomyocytes  

Microsoft Academic Search

Icariin, the primary active component of Epimedium extracts, has recently been shown to induce cardiomyocyte differentiation\\u000a of murine embryonic stem (mES) cells in vitro. However, as these cardiomyocytes were not functionally characterized, the potential\\u000a application of icariin-induced cardiomyocytes in clinical practice remains unclear. Therefore, in this study, we characterized\\u000a the structure and function of icariin-induced cardiomyocytes to evaluate their potential

Xiaodong Sun; Xiuwei Sun; Xiudong Jin; Xiaoli Zhang; Chunling Liu; Lei Lei; Lianhong Jin; Huiwen Liu

2011-01-01

247

Assessment of Differential Item Functioning for Demographic Comparisons in the MOS SF36 Health Survey  

Microsoft Academic Search

Objective: To investigate whether items of the Medical Outcomes Study (MOS) 36-Item Short-Form Health Status Survey (SF-36) exhibited\\u000a differential item functioning (DIF) with respect to age, education, race, and gender. Methods: The data for this study come from two large national datasets, the MOS and the 1990 National Survey of Functional Health\\u000a Status (NSFHS). We used logistic regression to identify

Anthony J. Perkins; Timothy E. Stump; Patrick O. Monahan; Colleen A. McHorney

2006-01-01

248

Assessing the Item Response Theory with Covariate (IRT-C) Procedure for Ascertaining Differential Item Functioning  

ERIC Educational Resources Information Center

We evaluate the item response theory with covariates (IRT-C) procedure for assessing differential item functioning (DIF) without preknowledge of anchor items (Tay, Newman, & Vermunt, 2011). This procedure begins with a fully constrained baseline model, and candidate items are tested for uniform and/or nonuniform DIF using the Wald statistic.…

Tay, Louis; Vermunt, Jeroen K.; Wang, Chun

2013-01-01

249

A posteriori finite element bounds for linear-functional outputs of elliptic partial differential equations  

Microsoft Academic Search

We present a domain decomposition finite element technique for efficiently generating lower and upper bounds to outputs which are linear functionals of the solutions to symmetric or nonsymmetric second-order coercive linear partial differential equations in two space dimensions. The method is based upon the construction of an augmented Lagrangian, in which the objective is a quadratic ‘energy’ reformulation of the

Marius Paraschivoiu; Jaime Peraire; Anthony T. Patera

1997-01-01

250

Potential Sources of Differential Item Functioning in the Adaptation of Tests  

ERIC Educational Resources Information Center

This report shows a classification of differential item functioning (DIF) sources that have an effect on the adaptation of tests. This classification is based on linguistic and cultural criteria. Four general DIF sources are distinguished: cultural relevance, translation problems, morph syntactical differences, and semantic differences. The…

Elosua, Paula; Lopez-Jauregui, Alicia

2007-01-01

251

Explaining Crossing DIF in Polytomous Items Using Differential Step Functioning Effects  

ERIC Educational Resources Information Center

Crossing, or intersecting, differential item functioning (DIF) is a form of nonuniform DIF that exists when the sign of the between-group difference in expected item performance changes across the latent trait continuum. The presence of crossing DIF presents a problem for many statistics developed for evaluating DIF because positive and negative…

Penfield, Randall D.

2010-01-01

252

Identification of Differential Item Functioning in Assessment Booklet Designs with Structurally Missing Data  

ERIC Educational Resources Information Center

The Mantel-Haenszel procedure is a popular technique for determining items that may exhibit differential item functioning (DIF). Numerous studies have focused on the strengths and weaknesses of this procedure, but few have focused the performance of the Mantel-Haenszel method when structurally missing data are present as a result of test booklet…

Goodman, Joshua T.; Willse, John T.; Allen, Nancy L.; Klaric, John S.

2011-01-01

253

Sensitivity analysis for feedforward artificial neural networks with differentiable activation functions  

Microsoft Academic Search

A method for computing the network output sensitivities with respect to variations in the inputs for multilayer feedforward artificial neural networks with differentiable activation functions is presented. It is applied to obtain expressions for the first- and second-order sensitivities. An example is introduced along with a discussion to illustrate how the sensitivities are calculated and to show how they compare

Sherif Hashem; Honeywell SSDC

1992-01-01

254

A Comparison of the Logistic Regression and Mantel-Haenszel Procedures for Detecting Differential Item Functioning.  

ERIC Educational Resources Information Center

Performance of the logistic regression (LR) procedure was compared to that of the Mantel Haenszel (MH) procedure in the detection of uniform and nonuniform differential item functioning on a simulation examining distributional properties of the LR and MH test statistics and the relative power of the two procedures. (SLD)

Rogers, H. Jane; Swaminathan, Hariharan

1993-01-01

255

Usefulness of gastric bilimetry in differential diagnostics of the clinical form of functional dyspepsia  

Microsoft Academic Search

Introduction: The pathogenesis of functional dyspepsia (FD) is not fully recognized. Upper gastrointestinal tract motor abnormalities are listed among its numerous factors. Duodenogastric reflux (DGR) is also thought to be one of the causes of ailments occurring in these patients. Aim: The aim of this study was to estimate the usefulness of 24-hour gastric bilim - etry in differential diagnostics

Krzysztof Szadkowski; Marek Romanowski; Wojciech Piotrowski; Cezary Chojnacki

256

Parent Ratings of ADHD Symptoms: Generalized Partial Credit Model Analysis of Differential Item Functioning across Gender  

ERIC Educational Resources Information Center

Objective: Generalized partial credit model, which is based on item response theory (IRT), was used to test differential item functioning (DIF) for the "Diagnostic and Statistical Manual of Mental Disorders" (4th ed.), inattention (IA), and hyperactivity/impulsivity (HI) symptoms across boys and girls. Method: To accomplish this, parents completed…

Gomez, Rapson

2012-01-01

257

Parent Ratings of ADHD Symptoms: Differential Symptom Functioning across Malaysian Malay and Chinese Children  

ERIC Educational Resources Information Center

This study examined differential symptom functioning (DSF) in ADHD symptoms across Malay and Chinese children in Malaysia. Malay (N = 571) and Chinese (N = 254) parents completed the Disruptive Behavior Rating Scale, which lists the DSM-IV ADHD symptoms. DSF was examined using the multiple indicators multiple causes (MIMIC) structural equation…

Gomez, Rapson; Vance, Alasdair

2008-01-01

258

Does Impaired Executive Functioning Differentially Impact Verbal Memory Measures in Older Adults with Suspected Dementia?  

Microsoft Academic Search

The purpose of this study was to examine whether executive dysfunction differentially impacts list-learning and story recall tasks in a sample of older adults referred for suspected cognitive impairment. Older adults (N = 61) with mild cognitive impairment (MCI) or probable mild dementia, and those who did not meet criteria for diagnosis of dementia, were assessed using measures of executive function and

Brian L. Brooks; Linda E. Weaver; Charles T. Scialfa

2006-01-01

259

Gender-Related Differential Item Functioning on a Middle-School Mathematics Performance Assessment.  

ERIC Educational Resources Information Center

This study examined gender-related differential item functioning (DIF) using a mathematics performance assessment, the QUASAR Cognitive Assessment Instrument (QCAI), administered to middle school students. The QCAI was developed for the Quantitative Understanding: Amplifying Student Achievement and Reading (QUASAR) project, which focuses on…

Lane, Suzanne; And Others

260

Testing for Nonuniform Differential Item Functioning with Multiple Indicator Multiple Cause Models  

ERIC Educational Resources Information Center

In extant literature, multiple indicator multiple cause (MIMIC) models have been presented for identifying items that display uniform differential item functioning (DIF) only, not nonuniform DIF. This article addresses, for apparently the first time, the use of MIMIC models for testing both uniform and nonuniform DIF with categorical indicators. A…

Woods, Carol M.; Grimm, Kevin J.

2011-01-01

261

Content Analysis of Gender-Related Differential Item Functioning TIMSS Items in Mathematics in Jordan  

ERIC Educational Resources Information Center

The purpose of this study is to analyze items that exhibit gender-related Differential Item Functioning (DIF) in Mathematics in Jordan. Data was taken from the TIMSS 1999 of Jordan, which includes responses of 5, 299 eighth grade students. Mantel-Haenszel (MH) DIF procedure was applied to 124 multiple-choice items. The results showed that 37 items…

Innabi, Hanan; Dodeen, Hamzeh

2006-01-01

262

Functional Differentiation of Bundle Sheath and Mesophyll Maize Chloroplasts Determined by Comparative Proteomics  

Microsoft Academic Search

Chloroplasts of maize (Zea mays) leaves differentiate into specific bundle sheath (BS) and mesophyll (M) types to accommodate C4 photosynthesis. Consequences for other plastid functions are not well understood but are addressed here through a quantitative comparative proteome analysis of purified M and BS chloroplast stroma. Three independent techniques were used, including cleavable stable isotope coded affinity tags. Enzymes involved

Wojciech Majeran; Yang Cai; Qi Sun; Klaas J. van Wijka

2005-01-01

263

Evaluation of Model Selection Strategies for Cross-Level Two-Way Differential Item Functioning Analysis  

ERIC Educational Resources Information Center

Model specification issues on the cross-level two-way differential item functioning model were previously investigated by Patarapichayatham et al. (2009). Their study clarified that an incorrect model specification can easily lead to biased estimates of key parameters. The objective of this article is to provide further insights on the issue by…

Patarapichayatham, Chalie; Kamata, Akihito; Kanjanawasee, Sirichai

2012-01-01

264

Detecting Native Language Group Differences at the Subskills Level of Reading: A Differential Skill Functioning Approach  

ERIC Educational Resources Information Center

Differential skill functioning (DSF) exists when examinees from different groups have different probabilities of successful performance in a certain subskill underlying the measured construct, given that they have the same ability on the overall construct. Using a DSF approach, this study examined the differences between two native language…

Li, Hongli; Suen, Hoi K.

2013-01-01

265

Item Purification in Differential Item Functioning Using Generalized Linear Mixed Models  

ERIC Educational Resources Information Center

For this dissertation, four item purification procedures were implemented onto the generalized linear mixed model for differential item functioning (DIF) analysis, and the performance of these item purification procedures was investigated through a series of simulations. Among the four procedures, forward and generalized linear mixed model (GLMM)…

Liu, Qian

2011-01-01

266

A Monte Carlo Study Investigating Missing Data, Differential Item Functioning, and Effect Size  

ERIC Educational Resources Information Center

The use of polytomous items in assessments has increased over the years, and as a result, the validity of these assessments has been a concern. Differential item functioning (DIF) and missing data are two factors that may adversely affect assessment validity. Both factors have been studied separately, but DIF and missing data are likely to occur…

Garrett, Phyllis

2009-01-01

267

Analysis of School Context Effects on Differential Item Functioning Using Hierarchical Generalized Linear Models  

ERIC Educational Resources Information Center

This article considers and illustrates a strategy to study effects of school context on differential item functioning (DIF) in large-scale assessment. The approach employs a hierarchical generalized linear modeling framework to (a) detect DIF, and (b) identify school-level correlates of the between-group differences in item performance. To…

Cheong, Yuk Fai

2006-01-01

268

Iterative Purification and Effect Size Use with Logistic Regression for Differential Item Functioning Detection  

ERIC Educational Resources Information Center

Two unresolved implementation issues with logistic regression (LR) for differential item functioning (DIF) detection include ability purification and effect size use. Purification is suggested to control inaccuracies in DIF detection as a result of DIF items in the ability estimate. Additionally, effect size use may be beneficial in controlling…

French, Brian F.; Maller, Susan J.

2007-01-01

269

Differential Effects of a Tier Two Behavior Intervention Based on Function of Problem Behavior  

ERIC Educational Resources Information Center

The purpose of this study was to investigate the effectiveness of a tier two daily behavior card intervention and differential effects based on function of problem behavior. The participants were 36 elementary school students nominated for additional intervention beyond universal School-Wide Positive Behavior Support. Measures included…

McIntosh, Kent; Campbell, Amy L.; Carter, Deborah Russell; Dickey, Celeste Rossetto

2009-01-01

270

Examining Differential Item Functioning in Reading Assessments for Students with Disabilities. CRESST Report 744  

ERIC Educational Resources Information Center

This study examines performance differences between students with disabilities and students without disabilities students using differential item functioning (DIF) analyses in a high-stakes reading assessment. Results indicated that for Grade 9, many items exhibited DIF. Items that exhibited DIF were more likely to be located in the second half…

Abedi, Jamal; Leon, Seth; Kao, Jenny C.

2008-01-01

271

The MIMIC Method with Scale Purification for Detecting Differential Item Functioning  

ERIC Educational Resources Information Center

This study implements a scale purification procedure onto the standard MIMIC method for differential item functioning (DIF) detection and assesses its performance through a series of simulations. It is found that the MIMIC method with scale purification (denoted as M-SP) outperforms the standard MIMIC method (denoted as M-ST) in controlling…

Wang, Wen-Chung; Shih, Ching-Lin; Yang, Chih-Chien

2009-01-01

272

Group-Specific Effects of Matching Subtest Contamination on the Identification of Differential Item Functioning  

ERIC Educational Resources Information Center

A differential item functioning (DIF) simulation study was conducted to explore the type and level of impact that contamination had on type I error and power rates in DIF analyses when the suspect item favored the same or opposite group as the DIF items in the matching subtest. Type I error and power rates were displayed separately for the…

Keiffer, Elizabeth Ann

2011-01-01

273

Utility of the Mantel-Haenszel Procedure for Detecting Differential Item Functioning in Small Samples  

ERIC Educational Resources Information Center

Sample-size restrictions limit the contingency table approaches based on asymptotic distributions, such as the Mantel-Haenszel (MH) procedure, for detecting differential item functioning (DIF) in many practical applications. Within this framework, the present study investigated the power and Type I error performance of empirical and inferential…

Fidalgo, Angel M.; Ferreres, Doris; Muniz, Jose

2004-01-01

274

Determinants of Differential Item Functioning in an Elementary Mathematics Test with Accommodations  

ERIC Educational Resources Information Center

Those items or test characteristics that are likely to result in differential item functioning (DIF) across accommodated test forms in statewide tests have received little attention. An examination of elementary-level student performance across accommodated test forms in a large-scale mathematics assessment revealed DIF variations by grades,…

Chae, Soo Eun; Kim, Doyoung; Han, Jae-Ho

2012-01-01

275

Comparison of Differential Item Functioning Determination Techniques: HGLM, LR and IRT-LR  

ERIC Educational Resources Information Center

The aim of this research is to determine differential item functioning (DIF) by hierarchical linear modeling (HGLM) on test items and comparing these results by the DIF results determined by logistic regression (LR) and IRT-likelihood ratio (IRT-LR) techniques. Investigating the concordance between the techniques in determining the items with DIF,…

Acar, Tulin; Kelecioglu, Hulya

2010-01-01

276

A Synthesis of the Peer-Reviewed Differential Bundle Functioning Research  

ERIC Educational Resources Information Center

The purpose of this article was to present a synthesis of the peer-reviewed differential bundle functioning (DBF) research that has been conducted to date. A total of 16 studies were synthesized according to the following characteristics: tests used and learner groups, organizing principles used for developing bundles, DBF detection methods used,…

Banks, Kathleen

2013-01-01

277

A Comparison of Four Methods for Detecting Differential Item Functioning in Ordered Response Items  

ERIC Educational Resources Information Center

Item bias is a major threat to measurement validity. Methods for detecting differential item functioning (DIF) are now commonly used to identify potentially biased items. DIF detection methods for dichotomous items are well developed, but those for ordinal items are less well developed. In this article, the authors compare four methods for…

Kristjansson, Elizabeth; Aylesworth, Richard; Mcdowell, Ian; Zumbo, Bruno D.

2005-01-01

278

High Efficient Differentiation of Functional Hepatocytes from Porcine Induced Pluripotent Stem Cells  

PubMed Central

Hepatocyte transplantation is considered to be a promising therapy for patients with liver diseases. Induced pluripotent stem cells (iPSCs) provide an unlimited source for the generation of functional hepatocytes. In this study, we generated iPSCs from porcine ear fibroblasts (PEFs) by overexpressing Sox2, Klf4, Oct4, and c-Myc (SKOM), and developed a novel strategy for the efficient differentiation of hepatocyte-like cells from porcine iPSCs by following the processes of early liver development. The differentiated cells displayed the phenotypes of hepatocytes, exhibited classic hepatocyte-associated bio-functions, such as LDL uptake, glycogen storage and urea secretion, as well as possessed the metabolic activities of cytochrome P-450 (CYP) 3A and 2C. Furthermore, we compared the hepatocyte differentiation efficacy of our protocol with another published method, and the results demonstrated that our differentiation strategy could significantly improve the generation of morphological and functional hepatocyte-like cells from porcine iPSCs. In conclusion, this study establishes an efficient method for in vitro generation of functional hepatocytes from porcine iPSCs, which could represent a promising cell source for preclinical testing of cell-based therapeutics for liver failure and for pharmacological applications.

Ao, Ying; Mich-Basso, Jocelyn Danielle; Lin, Bo; Yang, Lei

2014-01-01

279

Cauchy problem and Green's functions for first order differential operators and algebraic quantization  

SciTech Connect

Existence and uniqueness of advanced and retarded fundamental solutions (Green's functions) and of global solutions to the Cauchy problem is proved for a general class of first order linear differential operators on vector bundles over globally hyperbolic Lorentzian manifolds. This is a core ingredient to CAR-/CCR-algebraic constructions of quantum field theories on curved spacetimes, particularly for higher spin field equations.

Muehlhoff, Rainer [Berlin Mathematical School, TU Berlin, Mathematisches Institut, MA 2-2, Strasse des 17. Juni 136, 10623 Berlin (Germany)

2011-02-15

280

Resolvent Estimates of Elliptic Differential and Finite Element Operators in Pairs of Function Spaces.  

National Technical Information Service (NTIS)

We present some resolvent estimates of elliptic differential and finite element operators in pairs of function spaces, for which the first space in a pair is endowed with stronger norm. In this work we deal with estimates in (Lebesgue, Lebesgue), (Holder,...

N. Y. Bakaev

2002-01-01

281

Perineal Accessory Scrotum with Congenital Lipoma: A Rare Case Report  

PubMed Central

A case of accessory scrotum in a 1-year-old boy is reported because of its rarity. A boy presented with a tumor mass attached with scrotum-like skin on its tip in the right side of perineum between the scrotum and anus. Both testes had descended into the scrotum. There was no other urological anomaly. Histological findings of the tumor indicated perineal lipoma, and the scrotum-like portion accessory scrotum. An overview of sequences during the normal development of male external genitalia has been provided and the deranged mechanism resulting in this anomaly has been reviewed with hypothesis regarding etiology of accessory scrotum.

Chatterjee, Souvik; Gajbhiye, Vishal; Nath, Sasanka; Ghosh, Dipak; Chattopadhyay, Sarbani; Das, Sukanta Kumar

2012-01-01

282

Complexin Clamps Asynchronous Release by Blocking a Secondary Ca2+-Sensor via its Accessory ?-Helix  

PubMed Central

Complexin activates and clamps neurotransmitter release; impairing complexin function decreases synchronous, but increases spontaneous and asynchronous synaptic vesicle exocytosis. Here, we show that complexin – different from the Ca2+-sensor synaptotagmin-1 – activates synchronous exocytosis by promoting synaptic vesicle priming, but clamps spontaneous and asynchronous exocytosis – similar to synaptotagmin-1 – by blocking a secondary Ca2+-sensor. Activation and clamping functions of complexin depend on distinct, autonomously acting sequences, namely its N-terminal region and accessory ?helix, respectively. Mutations designed to test whether the accessory ?-helix of complexin clamps exocytosis by inserting into SNARE-complexes support this hypothesis, suggesting that the accessory ?-helix blocks completion of trans-SNARE-complex assembly until Ca2+-binding to synaptotagmin relieves this block. Moreover, a juxtamembranous mutation in the SNARE-protein synaptobrevin-2, which presumably impairs force transfer from nascent trans-SNARE complexes onto fusing membranes, also unclamps spontaneous fusion by disinhibiting a secondary Ca2+-sensor. Thus, complexin performs mechanistically distinct activation and clamping functions that operate in conjunction with synaptotagmin-1 by controlling trans-SNARE-complex assembly.

Yang, Xiaofei; Kaeser-Woo, Yea Jin; Pang, Zhiping P.; Xu, Wei; Sudhof, Thomas C.

2010-01-01

283

Complexin clamps asynchronous release by blocking a secondary Ca(2+) sensor via its accessory ? helix.  

PubMed

Complexin activates and clamps neurotransmitter release; impairing complexin function decreases synchronous, but increases spontaneous and asynchronous synaptic vesicle exocytosis. Here, we show that complexin-different from the Ca(2+) sensor synaptotagmin-1-activates synchronous exocytosis by promoting synaptic vesicle priming, but clamps spontaneous and asynchronous exocytosis-similar to synaptotagmin-1-by blocking a secondary Ca(2+) sensor. Activation and clamping functions of complexin depend on distinct, autonomously acting sequences, namely its N-terminal region and accessory ? helix, respectively. Mutations designed to test whether the accessory ? helix of complexin clamps exocytosis by inserting into SNARE-complexes support this hypothesis, suggesting that the accessory ? helix blocks completion of trans-SNARE-complex assembly until Ca(2+) binding to synaptotagmin relieves this block. Moreover, a juxtamembranous mutation in the SNARE-protein synaptobrevin-2, which presumably impairs force transfer from nascent trans-SNARE complexes onto fusing membranes, also unclamps spontaneous fusion by disinhibiting a secondary Ca(2+) sensor. Thus, complexin performs mechanistically distinct activation and clamping functions that operate in conjunction with synaptotagmin-1 by controlling trans-SNARE-complex assembly. PMID:21145004

Yang, Xiaofei; Kaeser-Woo, Yea Jin; Pang, Zhiping P; Xu, Wei; Südhof, Thomas C

2010-12-01

284

Krüppel-like factor 4 is involved in functional differentiation of testicular Sertoli cells.  

PubMed

Krüppel-like factor 4 (KLF4) is a pleiotropic zinc finger transcription factor that regulates genes being involved in differentiation and cell-cycle control. Knockout studies revealed a critical function for KLF4 in the terminal differentiation of many epithelial cells. In testicular Sertoli cells, Klf4 is strongly inducible by the glycoprotein follicle stimulating hormone (FSH). Because KLF4 is essential for postnatal survival in mice, we deleted Klf4 specifically in Sertoli cells using the Cre/loxP system. Importantly, around postnatal day 18, a critical period of terminal Sertoli cell differentiation, mutant seminiferous tubules exhibited a disorganized germinal epithelium and delayed lumen formation. The ultrastructural finding of highly vacuolized Sertoli cell cytoplasm and the identification of differentially expressed genes, which are known to play roles during vesicle transport and fusion or for maintenance of the differentiated cell state, suggest impaired apical secretion of the Sertoli cell. Interestingly, a high proportion of all identified genes was localized in a small subregion of chromosome 7, suggesting coordinated regulation. Intriguingly, adult mutant mice are fertile and show normal testicular morphology, although the testosterone levels are decreased. In summary, KLF4 plays a significant role for proper and timely Sertoli cell differentiation in pubertal mice. PMID:18243172

Godmann, Maren; Katz, Jonathan P; Guillou, Florian; Simoni, Manuela; Kaestner, Klaus H; Behr, Rüdiger

2008-03-15

285

Functional Role of Mst1/Mst2 in Embryonic Stem Cell Differentiation  

PubMed Central

The Hippo pathway is an evolutionary conserved pathway that involves cell proliferation, differentiation, apoptosis and organ size regulation. Mst1 and Mst2 are central components of this pathway that are essential for embryonic development, though their role in controlling embryonic stem cells (ES cells) has yet to be exploited. To further understand the Mst1/Mst2 function in ES cell pluripotency and differentiation, we derived Mst1/Mst2 double knockout (Mst-/-) ES cells to completely perturb Hippo signaling. We found that Mst-/- ES cells express higher level of Nanog than wild type ES cells and show differentiation resistance after LIF withdrawal. They also proliferate faster than wild type ES cells. Although Mst-/- ES cells can form embryoid bodies (EBs), their differentiation into tissues of three germ layers is distorted. Intriguingly, Mst-/- ES cells are unable to form teratoma. Mst-/- ES cells can differentiate into mesoderm lineage, but further differentiation to cardiac lineage cells is significantly affected. Microarray analysis revealed that ligands of non-canonical Wnt signaling, which is critical for cardiac progenitor specification, are significantly repressed in Mst-/- EBs. Taken together our results showed that Mst1/Mst2 are required for proper cardiac lineage cell development and teratoma formation.

Li, Peng; Chen, Ying; Mak, Kinglun Kingston; Wong, Chun Kwok; Wang, Chi Chiu; Yuan, Ping

2013-01-01

286

A novel application of radial basis functions for solving a model of first-order integro-ordinary differential equation  

Microsoft Academic Search

In this paper two common collocation approaches based on radial basis functions (RBFs) have been considered; one is computed through the differentiation process (DRBF) and the other one is computed through the integration process (IRBF). We investigate these two approaches on the Volterra’s Population Model which is an integro-differential equation without converting it to an ordinary differential equation. To solve

K. Parand; S. Abbasbandy; S. Kazem; J. A. Rad

2011-01-01

287

Viscoelastic properties of differentiating blood cells are fate- and function-dependent.  

PubMed

Although cellular mechanical properties are known to alter during stem cell differentiation, understanding of the functional relevance of such alterations is incomplete. Here, we show that during the course of differentiation of human myeloid precursor cells into three different lineages, the cells alter their viscoelastic properties, measured using an optical stretcher, to suit their ultimate fate and function. Myeloid cells circulating in blood have to be advected through constrictions in blood vessels, engendering the need for compliance at short time-scales (differentiated cell types reduce their steady-state viscosity by more than 50% and show over 140% relative increase in their ability to migrate through tissue-like pores at long time-scales (>minutes), compared to undifferentiated cells. These findings suggest that reduction in steady-state viscosity is a physiological adaptation for enhanced migration through tissues. Our results indicate that the material properties of cells define their function, can be used as a cell differentiation marker and could serve as target for novel therapies. PMID:23028868

Ekpenyong, Andrew E; Whyte, Graeme; Chalut, Kevin; Pagliara, Stefano; Lautenschläger, Franziska; Fiddler, Christine; Paschke, Stephan; Keyser, Ulrich F; Chilvers, Edwin R; Guck, Jochen

2012-01-01

288

Human endometrial stromal stem cells differentiate into megakaryocytes with the ability to produce functional platelets.  

PubMed

Human endometrium is a high dynamic tissue that contains endometrial stromal stem cells (hESSCs). The hESSCs have been differentiated into a number of cell lineages. However, differentiation of hESSCs into megakaryocytes (MKs) has not yet been investigated. The aim of this study was to investigate the feasibility of MK generation from hESSCs and subsequent production of functional platelets (PLTs). In our study, hESSCs were cultured from endometrial stromal cells as confirmed by positive stromal cell specific markers (CD90 and CD29) and negative hematopoietic stem cell markers (CD45 and CD34) expression. Then, hESSCs were differentiated in a medium supplemented with thrombopoietin (TPO) for 18 days. The MK differentiation was analyzed by flow cytometry and confocal microscopy. The differentiation medium was collected for PLT production analysis by flow cytometry, transmission electron microscopy and functional measurements. Our results show: 1) MKs were successfully generated from hESSCs as identified by expression of specific markers (CD41a: 1 ± 0.09% and 39 ± 3.0%; CD42b: 1.2 ± 0.06% and 28 ± 2.0%, control vs. differentiation) accompanied with reduction of pluripotent transcription factors (Oct4 and Sox2) expression; 2) The level of PLTs in the differentiation medium was 16 ± 1 number/µl as determined by size (2-4 µm) and CD41a expression (CD41a: 1 ± 0.4% and 90±2.0%, control vs. differentiation); 3) Generated PLTs were functional as evidenced by the up-regulation of CD62p expression and fibrinogen binding following thrombin stimulation; 4) Released PLTs showed similar ultra-structure characteristics (alpha granules, vacuoles and dense tubular system) as PLTs from peripheral blood determined by electron microscopic analysis. Data demonstrate the feasibility of generating MKs from hESSCs, and that the generated MKs release functional PLTs. Therefore, hESSCs could be a potential new stem cell source for in vitro MK/PLT production. PMID:22952951

Wang, Jinju; Chen, Shuzhen; Zhang, Cheng; Stegeman, Samantha; Pfaff-Amesse, Teresa; Zhang, Ying; Zhang, Wenfeng; Amesse, Lawrence; Chen, Yanfang

2012-01-01

289

Low functional redundancy in sponges as a result of differential picoplankton use.  

PubMed

Understanding the way that closely related co-existing species utilize resources is important for explaining biodiversity patterns and understanding how organisms contribute to ecosystem functioning. Here we investigated the utilization of food resources by sponges to determine if different sponge species from the same habitat utilize different fractions of their picoplanktonic food resources, and examined the validity of treating sponges as a single trophic group in functional diversity assessments. Using flow cytometry, we demonstrated that different groups of sponge species have different retention efficiencies for different types of picoplankton, providing evidence for differential use of food resources among different sponge species living in the same habitat. Although the mechanisms to explain these differences remain undetermined, we propose that this differential food use means that the feeding activities of sponges should not be considered as a single functional role. PMID:23493506

Perea-Blázquez, Alejandra; Davy, Simon K; Bell, James J

2013-02-01

290

Exponential stability analysis of impulsive stochastic functional differential systems with delayed impulses  

NASA Astrophysics Data System (ADS)

This paper is concerned with the exponential stability analysis of impulsive stochastic functional differential systems with delayed impulses. Although the stability of impulsive stochastic functional differential systems have received considerable attention. However, relatively few works are concerned with the stability of systems with delayed impulses and our aim here is mainly to close the gap. Based on the Lyapunov functions and Razumikhin techniques, some exponential stability criteria are derived, which show that the system will stable if the impulses' frequency and amplitude are suitably related to the increase or decrease of the continuous flows. The obtained results improve and complement ones from some recent works. Three examples are discussed to illustrate the effectiveness and the advantages of the results obtained.

Cheng, Pei; Deng, Feiqi; Yao, Fengqi

2014-06-01

291

Breakage-fusion-bridge cycles and large insertions contribute to the rapid evolution of accessory chromosomes in a fungal pathogen.  

PubMed

Chromosomal rearrangements are a major driver of eukaryotic genome evolution, affecting speciation, pathogenicity and cancer progression. Changes in chromosome structure are often initiated by mis-repair of double-strand breaks in the DNA. Mis-repair is particularly likely when telomeres are lost or when dispersed repeats misalign during crossing-over. Fungi carry highly polymorphic chromosomal complements showing substantial variation in chromosome length and number. The mechanisms driving chromosome polymorphism in fungi are poorly understood. We aimed to identify mechanisms of chromosomal rearrangements in the fungal wheat pathogen Zymoseptoria tritici. We combined population genomic resequencing and chromosomal segment PCR assays with electrophoretic karyotyping and resequencing of parents and offspring from experimental crosses to show that this pathogen harbors a highly diverse complement of accessory chromosomes that exhibits strong global geographic differentiation in numbers and lengths of chromosomes. Homologous chromosomes carried highly differentiated gene contents due to numerous insertions and deletions. The largest accessory chromosome recently doubled in length through insertions totaling 380 kb. Based on comparative genomics, we identified the precise breakpoint locations of these insertions. Nondisjunction during meiosis led to chromosome losses in progeny of three different crosses. We showed that a new accessory chromosome emerged in two viable offspring through a fusion between sister chromatids. Such chromosome fusion is likely to initiate a breakage-fusion-bridge (BFB) cycle that can rapidly degenerate chromosomal structure. We suggest that the accessory chromosomes of Z. tritici originated mainly from ancient core chromosomes through a degeneration process that included BFB cycles, nondisjunction and mutational decay of duplicated sequences. The rapidly evolving accessory chromosome complement may serve as a cradle for adaptive evolution in this and other fungal pathogens. PMID:23785303

Croll, Daniel; Zala, Marcello; McDonald, Bruce A

2013-06-01

292

Breakage-fusion-bridge Cycles and Large Insertions Contribute to the Rapid Evolution of Accessory Chromosomes in a Fungal Pathogen  

PubMed Central

Chromosomal rearrangements are a major driver of eukaryotic genome evolution, affecting speciation, pathogenicity and cancer progression. Changes in chromosome structure are often initiated by mis-repair of double-strand breaks in the DNA. Mis-repair is particularly likely when telomeres are lost or when dispersed repeats misalign during crossing-over. Fungi carry highly polymorphic chromosomal complements showing substantial variation in chromosome length and number. The mechanisms driving chromosome polymorphism in fungi are poorly understood. We aimed to identify mechanisms of chromosomal rearrangements in the fungal wheat pathogen Zymoseptoria tritici. We combined population genomic resequencing and chromosomal segment PCR assays with electrophoretic karyotyping and resequencing of parents and offspring from experimental crosses to show that this pathogen harbors a highly diverse complement of accessory chromosomes that exhibits strong global geographic differentiation in numbers and lengths of chromosomes. Homologous chromosomes carried highly differentiated gene contents due to numerous insertions and deletions. The largest accessory chromosome recently doubled in length through insertions totaling 380 kb. Based on comparative genomics, we identified the precise breakpoint locations of these insertions. Nondisjunction during meiosis led to chromosome losses in progeny of three different crosses. We showed that a new accessory chromosome emerged in two viable offspring through a fusion between sister chromatids. Such chromosome fusion is likely to initiate a breakage-fusion-bridge (BFB) cycle that can rapidly degenerate chromosomal structure. We suggest that the accessory chromosomes of Z. tritici originated mainly from ancient core chromosomes through a degeneration process that included BFB cycles, nondisjunction and mutational decay of duplicated sequences. The rapidly evolving accessory chromosome complement may serve as a cradle for adaptive evolution in this and other fungal pathogens.

Croll, Daniel; Zala, Marcello; McDonald, Bruce A.

2013-01-01

293

21 CFR 878.4350 - Cryosurgical unit and accessories.  

Code of Federal Regulations, 2013 CFR

... FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GENERAL AND PLASTIC SURGERY DEVICES Surgical Devices § 878.4350 Cryosurgical unit and accessories. (a) Identification â(1)...

2013-04-01

294

21 CFR 878.4370 - Surgical drape and drape accessories.  

Code of Federal Regulations, 2013 CFR

... FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GENERAL AND PLASTIC SURGERY DEVICES Surgical Devices § 878.4370 Surgical drape and drape accessories. (a) Identification. A...

2013-04-01

295

21 CFR 878.4700 - Surgical microscope and accessories.  

Code of Federal Regulations, 2013 CFR

...SERVICES (CONTINUED) MEDICAL DEVICES GENERAL AND PLASTIC SURGERY DEVICES Surgical Devices § 878.4700 Surgical microscope...accessories is an AC-powered device intended for use during surgery to provide a magnified view of the surgical field....

2013-04-01

296

21 CFR 878.4160 - Surgical camera and accessories.  

Code of Federal Regulations, 2013 CFR

... FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GENERAL AND PLASTIC SURGERY DEVICES Surgical Devices § 878.4160 Surgical camera and accessories. (a) Identification. A surgical...

2013-04-01

297

21 CFR 878.1800 - Speculum and accessories.  

Code of Federal Regulations, 2013 CFR

... FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GENERAL AND PLASTIC SURGERY DEVICES Diagnostic Devices § 878.1800 Speculum and accessories. (a) Identification. A speculum is a...

2013-04-01

298

21 CFR 884.2700 - Intrauterine pressure monitor and accessories.  

Code of Federal Regulations, 2013 CFR

... § 884.2700 Intrauterine pressure monitor and accessories. (a) Identification. An intrauterine pressure monitor is a device designed to detect and measure intrauterine and amniotic fluid pressure with a catheter placed...

2013-04-01

299

Coronary anomaly with a left ventricular accessory chamber: Is it left ventricular aneurysm or diverticulum?  

PubMed

A 60-year-old male hypertensive was suspected to have post myocardial infarction left ventricular aneurysm. His transthoracic echocardiogram performed elsewhere reported an inferior wall left ventricular aneurysm. He was referred for coronary angiography. His coronary angiogram and repeat transthoracic echocardiogram demonstrated an accessory chamber arising from mid-inferior wall synchronously contracting with the left ventricle suggesting a diverticulum. In addition, he had anomalous coronary arteries with coronary artery disease. His electrocardiogram did not reveal any features suggestive of a post infarct aneurysm. This case illustrates the importance of a comprehensive clinical and echocardiographic examination with a broad differential thought process. PMID:23960694

Panduranga, Prashanth; Al-Riyami, Abdullah Amour

2012-07-01

300

DNA Polymerase ? and ? Switch by Sharing Accessory Subunits of DNA Polymerase ?*  

PubMed Central

Translesion DNA synthesis is an important branch of the DNA damage tolerance pathway that assures genomic integrity of living organisms. The mechanisms of DNA polymerase (Pol) switches during lesion bypass are not known. Here, we show that the C-terminal domain of the Pol ? catalytic subunit interacts with accessory subunits of replicative DNA Pol ?. We also show that, unlike other members of the human B-family of DNA polymerases, the highly conserved and similar C-terminal domains of Pol ? and Pol ? contain a [4Fe-4S] cluster coordinated by four cysteines. Amino acid changes in Pol ? that prevent the assembly of the [4Fe-4S] cluster abrogate Pol ? function in UV mutagenesis. On the basis of these data, we propose that Pol switches at replication-blocking lesions occur by the exchange of the Pol ? and Pol ? catalytic subunits on a preassembled complex of accessory proteins retained on DNA during translesion DNA synthesis.

Baranovskiy, Andrey G.; Lada, Artem G.; Siebler, Hollie M.; Zhang, Yinbo; Pavlov, Youri I.; Tahirov, Tahir H.

2012-01-01

301

Gfi1 functions downstream of Math1 to control intestinal secretory cell subtype allocation and differentiation  

PubMed Central

Gfi1 is a transcriptional repressor implicated in lymphomagenesis, neutropenia, and hematopoietic development, as well as ear and lung development. Here, we demonstrate that Gfi1 functions downstream of Math1 in intestinal secretory lineage differentiation. Gfi1-/- mice lack Paneth cells, have fewer goblet cells, and supernumerary enteroendocrine cells. Gfi1-/- mice show gene expression changes consistent with this altered cell allocation. These data suggest that Gfi1 functions to select goblet/Paneth versus enteroendocrine progenitors. We propose a model of intestinal cell fate choice in which ?-catenin and Cdx function upstream of Math1, and lineage-specific genes such as Ngn3 act downstream of Gfi1.

Shroyer, Noah F.; Wallis, Deeann; Venken, Koen J.T.; Bellen, Hugo J.; Zoghbi, Huda Y.

2005-01-01

302

Accessory cardiac bronchus: 3D CT demonstration in nine cases  

Microsoft Academic Search

.   Accessory cardiac bronchus (ACB) has been described mainly as isolated case reports in the literature. We report nine consecutive\\u000a cases of ACB, which occurred in five males and four females and were detected in 11,159 routine spiral CT examinations of\\u000a the chest, performed between 1994 and 1998. Frequency of the anomaly was 0.08 %. Accessory cardiac bronchus originated from

B. Ghaye; X. Kos; R. F. Dondelinger

1999-01-01

303

Accessory soleus muscle: a problem of awareness.  

PubMed

Reports of accessory soleus muscle are rare, perhaps as a result of it often remaining unrecognized. It presents as a swelling behind the ankle and may be mistaken for a tumour or inflammatory lesion, as occurred in the first of a series of three cases. The other two were incidental findings, one in a 30 year old man with an open tibial fracture and the other in a 9 month old child with a club foot. Patients present with either pain or a diagnostic problem. When large, it may make wearing of footwear difficult. Computerized tomography with electromyography enables confirmation of the diagnosis. Pain is relieved by epimysiotomy and when encountered incidentally during surgery, incision of the epimysium is all that is needed. Excision of the muscle may be considered only if wearing of footwear is difficult. The significance of its presence in a case of club foot is unknown. Disinsertion of its insertion was all that was required to obtain surgical correction of the deformity in the present case. Awareness of the condition will prevent unnecessary surgery in asymptomatic cases. PMID:8010925

Chittaranjan, B S; Babu, N V; Abraham, G

1994-07-01

304

Accessory brachialis muscle: a case report.  

PubMed

Variations of arm flexors are not uncommon with the exception of brachialis muscle. The role of brachialis is critical as it is the primary flexor of the elbow joint. Variations of brachialis are rare in literature. We present a case of an accessory-brachialis muscle (AcBr), found during routine cadaveric dissection. The AcBr originated from the lateral aspect of the brachialis muscle and lateral intermuscular septum. During its course towards the elbow, it crossed over the radial nerve and the distal tendon splits into two. The medial slip ran over the ulnar artery and merged with the deep fascia covering the pronator teres muscle, whereas lateral slip was inserted to the fascia covering the supinator. In the ipsilateral arm, an additional lateral cutaneous nerve of forearm (LCNF) was found coursing over the brachialis muscle medial to the LCNF. Clinical consideration of the present variations has been discussed. The present variation should be considered in the etiology of radial-tunnel syndrome (RTS). PMID:18487066

Pai, M M; Nayak, S R; Vadgaonkar, R; Ranade, A V; Prabhu, L V; Thomas, M; Sugavasi, R

2008-03-01

305

Estimation of time- and state-dependent delays and other parameters in functional differential equations  

NASA Technical Reports Server (NTRS)

A parameter estimation algorithm is developed which can be used to estimate unknown time- or state-dependent delays and other parameters (e.g., initial condition) appearing within a nonlinear nonautonomous functional differential equation. The original infinite dimensional differential equation is approximated using linear splines, which are allowed to move with the variable delay. The variable delays are approximated using linear splines as well. The approximation scheme produces a system of ordinary differential equations with nice computational properties. The unknown parameters are estimated within the approximating systems by minimizing a least-squares fit-to-data criterion. Convergence theorems are proved for time-dependent delays and state-dependent delays within two classes, which say essentially that fitting the data by using approximations will, in the limit, provide a fit to the data using the original system. Numerical test examples are presented which illustrate the method for all types of delay.

Murphy, K. A.

1990-01-01

306

Estimation of time- and state-dependent delays and other parameters in functional differential equations  

NASA Technical Reports Server (NTRS)

A parameter estimation algorithm is developed which can be used to estimate unknown time- or state-dependent delays and other parameters (e.g., initial condition) appearing within a nonlinear nonautonomous functional differential equation. The original infinite dimensional differential equation is approximated using linear splines, which are allowed to move with the variable delay. The variable delays are approximated using linear splines as well. The approximation scheme produces a system of ordinary differential equations with nice computational properties. The unknown parameters are estimated within the approximating systems by minimizing a least-squares fit-to-data criterion. Convergence theorems are proved for time-dependent delays and state-dependent delays within two classes, which say essentially that fitting the data by using approximations will, in the limit, provide a fit to the data using the original system. Numerical test examples are presented which illustrate the method for all types of delay.

Murphy, K. A.

1988-01-01

307

Distinctive Accessory Minerals, Textures and Crystal Habits in Biofilm Associated Gypsum Deposits  

NASA Astrophysics Data System (ADS)

Gypsum-depositing environments near Guerrero Negro, Baja California Sur, Mexico were investigated in order to differentiate the influence of microbial activity versus nonbiological processes upon sedimentary fabrics and minerals. Field sites were located in sabkhas (mudflats and anchialine pools) and in seawater concentration ponds in the salt production facility operated by Exportadora de Sal, S. A. Gypsum (CaSO4.2H2O) was classified according to sedimentary environment (e.g., mudflats, anchialine pools, saltern ponds, surface and subsurface sediments), sedimentary texture, mineral composition, crystal habit, brine composition and other geochemical and biological factors. Gypsum types that develop in the absence of biofilms include water column precipitates (pelagic grains) and subsedimentary crystalline discs that form from phreatic brine ripening. Subsedimentary gypsum forming in sabkha environments had a sinuous axial microtexture and poikilitically enclosed detrital particles whereas water column precipitates exhibited euhedral prismatic habits and extensive penetrative twinning. Gypsum that was influenced by biofilms included cumulate crusts and gypsooids / gypsolite developing in anchialine pools and in saltern concentration ponds. Gypsum precipitating within subaqueous benthic microbial mats, or biofilm/sediment surfaces offered compelling evidence of biofilm influence on crystal textures and habits. Biofilm effects include irregular high relief surface textures, accessory minerals (elemental sulfur, Ca-carbonate, Sr/Ca-sulfate, Mg-oxide and Mg- sulfate) and distinctive crystal habits. Elemental sulfur, Ca-carbonate, and Sr/Ca-sulfate are known byproducts of bacterially mediated sulfate reduction (BSR). Populations of gypsum crystals within biofilms exhibited euhedral to lensoidal morphologies with unique equant and distorted prismatic forms. These forms had been shown to arise from form- and face-specific inhibition by bioorganic functional groups (Cody, 1991; Cody and Cody 1991). Biofilms therefore may play an active role in influencing brine chemistry, inducing crystallization and modifying crystal habits, evidence of which is preserved in grain morphologies.

Vogel, M.; Des Marais, D.; Jahnke, L.; Parenteau, M.

2008-12-01

308

Principal Differential Analysis with a Continuous Covariate: Low Dimensional Approximations for Functional Data  

PubMed Central

Given a collection of n curves that are independent realizations of a functional variable, we are interested in finding patterns in the curve data by exploring low dimensional approximations to the curves. It is assumed that the data curves are noisy samples from the vector space span{f1, …, fm}, where f1, …, fm are unknown functions on the real interval (0, T) with square-integrable derivatives of all orders m or less, and m < n. Ramsay (1996) first proposed the method of regularized principal differential analysis as an alternative to principal component analysis for finding low dimensional approximations to curves. Principal differential analysis (PDA) is based on the following theorem: there exists an annihilating linear differential operator L of order m such that Lfi=0, i = 1, …, m (Coddington and Levinson 1955, Theorem 6.2). Principal differential analysis specifies m, then uses the data to estimate an annihilating linear differential operator (LDO). Smooth estimates of the coefficients of the LDO are obtained by minimizing a penalized sum of the squared norm of the residuals. In this context, the residual is that part of the data curve that is not annihilated by the LDO. PDA obtains the smooth low dimensional approximation to the data curves by projecting onto the null space of the estimated annihilating LDO; PDA is thus useful for obtaining low dimensional approximations to the data curves whether or not the interpretation of the annihilating LDO is intuitive or obvious from the context of the data. This paper extends PDA to allow for the coefficients in the linear differential operator to smoothly depend upon a single continuous covariate. The estimating equations for the coefficients allowing for a continuous covariate are derived; the penalty of Eilers and Marx (1996) is used to impose smoothness. The results of a small computer simulation study investigating the bias and variance properties of the estimator are reported.

Jin, Seoweon; Staniswalis, Joan G.; Mallawaarachchi, Indika

2012-01-01

309

Topical Hesperidin Improves Epidermal Permeability Barrier Function and Epidermal Differentiation in Normal Murine Skin  

PubMed Central

Orange peel extract appears to exhibit beneficial effects on skin whitening, inflammation, UVB protection, as well as keratinocyte proliferation. In the present study, we determine whether topical hesperidin influences epidermal permeability barrier function and its underlying mechanisms. Hairless mice were treated topically with 2% hesperidin or 70% ethanol alone twice daily for 6 days. At the end of treatment, basal barrier function as well as transepidermal water loss (TEWL) was measured 2 and 4 hours post barrier disruption. Epidermal proliferation and differentiation were evaluated by immunohistochemical staining and Western blot analysis. Additionally, lamellar body density and secretion were assessed by electron microscopy. Although there were no significant differences in basal barrier function, in comparison to control animals, topical hesperidin significantly accelerated barrier recovery at both 2 and 4 hours after acute barrier abrogation. Enhanced barrier function in hesperidin-treated skin correlated with stimulation of both epidermal proliferation and differentiation, as well as enhanced lamellar body secretion. These results indicate that topical hesperidin enhances epidermal permeability barrier homeostasis at least in part due to stimulation of epidermal proliferation, differentiation, as well as lamellar body secretion.

Hou, Maihua; Man, Mona; Man, Wenyan; Zhu, Wenyuan; Hupe, Melanie; Park, Kyungho; Crumrine, Debra; Elias, Peter M.; Man, Mao-Qiang

2012-01-01

310

Cytokine-induced differentiation of multipotent adult progenitor cells into functional smooth muscle cells  

PubMed Central

Smooth muscle formation and function are critical in development and postnatal life. Hence, studies aimed at better understanding SMC differentiation are of great importance. Here, we report that multipotent adult progenitor cells (MAPCs) isolated from rat, murine, porcine, and human bone marrow demonstrate the potential to differentiate into cells with an SMC-like phenotype and function. TGF-?1 alone or combined with PDGF-BB in serum-free medium induces a temporally correct expression of transcripts and proteins consistent with smooth muscle development. Furthermore, SMCs derived from MAPCs (MAPC-SMCs) demonstrated functional L-type calcium channels. MAPC-SMCs entrapped in fibrin vascular molds became circumferentially aligned and generated force in response to KCl, the L-type channel opener FPL64176, or the SMC agonists 5-HT and ET-1, and exhibited complete relaxation in response to the Rho-kinase inhibitor Y-27632. Cyclic distention (5% circumferential strain) for 3 weeks increased responses by 2- to 3-fold, consistent with what occurred in neonatal SMCs. These results provide evidence that MAPC-SMCs are phenotypically and functionally similar to neonatal SMCs and that the in vitro MAPC-SMC differentiation system may be an ideal model for the study of SMC development. Moreover, MAPC-SMCs may lend themselves to tissue engineering applications.

Ross, Jeffrey J.; Hong, Zhigang; Willenbring, Ben; Zeng, Lepeng; Isenberg, Brett; Lee, Eu Han; Reyes, Morayma; Keirstead, Susan A.; Weir, E. Kenneth; Tranquillo, Robert T.; Verfaillie, Catherine M.

2006-01-01

311

Second Argonne theory institute on differentiation of computational approximations of functions.  

SciTech Connect

A Theory Institute on ''Differentiation of Computational Approximations to Functions'' was held at Argonne National Laboratory on May 18--20, 1998. The institute was organized by Christian Bischof and Paul Hovland of the Mathematics and Computer Science Division at Argonne National Laboratory. The Theory Institute brought together 38 researchers from the US, Great Britain, France, and Germany. Mathematicians, computer scientists, physicists, and engineers from diverse disciplines discussed advances in automatic differentiation (AD) theory and software and described benefits from applying AD methods in application areas. These areas include fluid mechanics, structural engineering, optimization, meteorology, and computational mathematics for the solution of ordinary differential equations (ODEs) or differential algebraic equations (DAEs). This meeting was the fourth workshop dedicated to automatic differentiation. Earlier meetings were the 1991 SIAM conference in Breckenridge, Colorado; the first Argonne Theory Institute on computational differentiation in 1993; and the 1996 SIAM conference in Santa Fe, New Mexico. AD methods can be used whenever gradient information or higher-order derivative information must be computed. The problem is defined by a computer program (without gradient information) that is able to compute numerical values of some output variables for a given set of input variables. As a result of applying AD methods to this computer program, a new computer program is generated automatically to compute the derivatives of the output variables with respect to the input variables. This at first glance, astonishing fact can be easily understood by viewing the program from a compiler angle. A complicated computational sequence is split into a sequence of simple operations. Then, to compute the gradients, the chain rule of differentiation is applied successively to this sequence completely automatically. The resultant gradients are accurate up to roundoff errors (which are always present in numerical evaluations).

Bischof, C.H.; Eberhard, P.; Hovland, P.D.

1998-10-09

312

GATA3 and the T-cell lineage: essential functions before and after T-helper-2-cell differentiation  

Microsoft Academic Search

Many advances in our understanding of the molecules that regulate the development, differentiation and function of T cells have been made over the past few years. One important regulator of T-cell differentiation is the transcription factor GATA-binding protein 3 (GATA3). Although the main function of GATA3 is to act as a master transcription factor for the differentiation of T helper

Tzong-Shyuan Tai; Sung-Yun Pai; I-Cheng Ho

2009-01-01

313

BMP-2 peptide-functionalized nanopatterned substrates for enhanced osteogenic differentiation of human mesenchymal stem cells.  

PubMed

A variety of biophysical and biochemical factors control stem cell differentiation. In this study, we developed a nanopatterned substrate platform to surface immobilize osteoinductive bone morphogenetic protein-2 (BMP-2) peptides. Specifically, polyurethane acrylate (PUA) substrates with nanometer-scale groove- and dot-shaped topography were fabricated. The nanopatterned PUA surface was uniformly coated with poly(glycidyl methacrylate) (pGMA) by initiated chemical vapor deposition (iCVD) followed by covalent immobilization of BMP-2 peptides. This approach resulted in much more efficient BMP-2 peptide immobilization than physical adsorption. The combined effects of biochemical signals from BMP-2 peptides and nanotopographical stimulation on osteogenic differentiation of hMSCs were examined in culture with and without soluble osteogenic factors. Results of Alizarin Red S staining, immunostaining, and quantitative real-time polymerase chain reaction revealed that hMSCs cultured on nanopatterned surfaces with immobilized BMP-2 peptides exhibited greater potential for osteogenic differentiation than hMSCs on a flat surface. Furthermore, the nanopatterned substrates with BMP-2 peptides directed osteogenic differentiation of hMSCs even without osteogenesis soluble inducing factors. Substrates with nanotopography and bioactive signals that induce differentiation of stem cells towards specific lineages could be used to develop functional stem cell culture substrates and tissue engineered scaffolds for therapeutic applications. PMID:23830472

Kim, Mun-Jung; Lee, Bora; Yang, Kisuk; Park, Junyong; Jeon, Seokwoo; Um, Soong Ho; Kim, Dong-Ik; Im, Sung Gap; Cho, Seung-Woo

2013-10-01

314

Ablation of the calcium-sensing receptor in keratinocytes impairs epidermal differentiation and barrier function  

PubMed Central

The calcium-sensing receptor (CaR) plays an essential role in mediating Ca2+-induced keratinocyte differentiation in vitro. In this study, we generated keratinocyte-specific CaR knockout (EpidCaR-/-) mice to investigate the function of the CaR in epidermal development in vivo. EpidCaR-/- mice exhibited a delay in permeability barrier formation during embryonic development. Ion capture cytochemistry detected the loss of the epidermal Ca2+ gradient in the EpidCaR-/- mice. The expression of terminal differentiation markers and key enzymes mediating epidermal sphingolipid transport and processing in the EpidCaR-/- epidermis was significantly reduced. The EpidCaR-/- epidermis displayed a marked decrease in the number of lamellar bodies and lamellar body secretion, thinner lipid-bound cornified envelopes and a defective permeability barrier. Consistent with in vivo results, epidermal keratinocytes cultured from EpidCaR-/- mice demonstrated abnormal Ca2+I handling and diminished differentiation. The impairment in epidermal differentiation and permeability barrier in EpidCaR-/- mice maintained on a low calcium (0.02%) diet is more profound and persistent with age then in EpidCaR-/- mice maintained on a normal calcium (1.3%) diet. Deleting CaR perturbs the epidermal Ca2+ gradient and impairs keratinocyte differentiation and permeability barrier homeostasis, indicating a key role for the CaR in normal epidermal development.

Tu, Chia-Ling; Crumrine, Debra; Man, Mao-Qiang; Chang, Wenhan; Elalieh, Hashem; You, Michael; Elias, Peter M.; Bikle, Daniel D.

2012-01-01

315

Investigating Linguistic Sources of Differential Item Functioning Using Expert Think-Aloud Protocols in Science Achievement Tests  

ERIC Educational Resources Information Center

Even if national and international assessments are designed to be comparable, subsequent psychometric analyses often reveal differential item functioning (DIF). Central to achieving comparability is to examine the presence of DIF, and if DIF is found, to investigate its sources to ensure differentially functioning items that do not lead to bias.…

Roth, Wolff-Michael; Oliveri, Maria Elena; Sandilands, Debra Dallie; Lyons-Thomas, Juliette; Ercikan, Kadriye

2013-01-01

316

Using Item Response Theory and Model-Data Fit to Conceptualize Differential Item and Person Functioning for Students with Disabilities  

ERIC Educational Resources Information Center

The major purpose of this study is to describe a conceptual framework for examining differential item functioning (DIF) and differential person functioning (DPF) as types of model-data misfit within the context of assessing students with disabilities. Specifically, DIF and DPF can be viewed through the lens of residual analyses. Residual analyses…

Engelhard, George, Jr.

2009-01-01

317

Myelin basic protein functions as a microtubule stabilizing protein in differentiated oligodendrocytes.  

PubMed

Myelin basic protein (MBP) is an oligodendrocyte-specific protein essential for oligodendrocyte morphogenesis at late stages of cell differentiation. There is evidence that the morphogenetic function of MBP is mediated by MBP interaction with the cytoskeleton. Thus, an MBP/cytoplasmic microtubule association has been reported, and MBP has Ca(2+)/calmodulin-regulated microtubule cold-stabilizing activity in vitro. However, the unambiguous demonstration of a microtubule-stabilizing activity for MBP in cells has been difficult because oligodendrocytes contain variants of STOP (stable tubule only polypeptide) proteins, which are responsible for microtubule cold stability in different cell types. Herein, we have used genetic mouse models and RNA interference to assay independently the microtubule cold-stabilizing activities of MBP and of STOP in developing oligodendrocytes. In wild-type oligodendrocytes, microtubules were cold stable throughout maturation, which is consistent with the presence of STOP proteins from early stages of differentiation. In contrast, in oligodendrocytes from STOP-deficient mice, microtubules were cold labile in the absence of MBP expression or when MBP expression was restricted to the cell body and became stable in fully differentiated oligodendrocytes, where MBP is expressed in cell extensions. The suppression of MBP by RNA interference in STOP-deficient oligodendrocytes suppressed microtubule cold stability. Additionally, STOP suppression in oligodendrocytes derived from shiverer mice that lack MBP led to the complete suppression of microtubule cold stability at all stages of cell differentiation. These results demonstrate that both STOP and MBP function as microtubule-stabilizing proteins in differentiating oligodendrocytes and could be important for the morphogenetic function of MBP. PMID:16773649

Galiano, M R; Andrieux, A; Deloulme, J C; Bosc, C; Schweitzer, A; Job, D; Hallak, M E

2006-08-15

318

An efficient spectral method for ordinary differential equations with rational function coefficients  

NASA Technical Reports Server (NTRS)

We present some relations that allow the efficient approximate inversion of linear differential operators with rational function coefficients. We employ expansions in terms of a large class of orthogonal polynomial families, including all the classical orthogonal polynomials. These families obey a simple three-term recurrence relation for differentiation, which implies that on an appropriately restricted domain the differentiation operator has a unique banded inverse. The inverse is an integration operator for the family, and it is simply the tridiagonal coefficient matrix for the recurrence. Since in these families convolution operators (i.e. matrix representations of multiplication by a function) are banded for polynomials, we are able to obtain a banded representation for linear differential operators with rational coefficients. This leads to a method of solution of initial or boundary value problems that, besides having an operation count that scales linearly with the order of truncation N, is computationally well conditioned. Among the applications considered is the use of rational maps for the resolution of sharp interior layers.

Coutsias, Evangelos A.; Torres, David; Hagstrom, Thomas

1994-01-01

319

Differential relationships between personal and community stressors and children's neurocognitive functioning.  

PubMed

Early adversity can alter development of neurocognition, including executive cognitive and emotional regulatory functions. This is the first study to explore differential relationships between personal (physical and emotional abuse and neglect, school and parental stressors) and community (neighborhood problems and witnessing neighborhood violence) stressors and neurocognition. Predominantly Latino children (n = 553) aged 10 to 12 years completed tasks measuring intelligence, impulsivity, problem solving, cognitive flexibility, decision making, and emotion attributions. Adjusting for age and parent education, bivariate regression analyses found exposure to personal stressors to be associated with relative deficits in at least one neurocognitive function. Community stressors were related to relative deficits in emotion attributions and problem solving. In multivariate analyses, neglect was related to misattributions of emotion and IQ deficits, and physical abuse was related to problem solving. Community stressors were not correlated with neurocognition when viewed relative to personal stressors. Stressor types were differentially associated with performance on specific neurocognitive tasks. PMID:18971345

Fishbein, Diana; Warner, Tara; Krebs, Christopher; Trevarthen, Nancy; Flannery, Barbara; Hammond, Jane

2009-11-01

320

Screening and functional analysis of a differential protein profile of human breast cancer  

PubMed Central

To improve the understanding of the enriched functions of proteins and to identify potential biomarkers in human breast cancer, the present study constructed a differentially expressed protein profile by screening immunohistochemistry maps of human breast cancer proteins. A total of 1,688 proteins were found to be differentially expressed in human breast cancer, including 773 upregulated and 915 downregulated proteins. Of these proteins, secreted and membrane proteins were screened and clustered, and more enriched biological functions and pathways were presented in the upregulated protein profiles. Furthermore, altered serum levels of peroxiredoxin (PRDX)2, PRDX6, cathepsin (CTS)B and CTSD were detected by ELISA assay. The present study provides a novel global mapping of potential breast cancer biomarkers that could be used as background to identify the altered pathways in human breast cancer, as well as potential cancer targets.

LIU, FU-JUN; WANG, XUE-BO; CAO, AI-GUO

2014-01-01

321

Computer generation of series and rational function solutions to partial differential initial value problems  

Microsoft Academic Search

Series and rational function approximations provide a viable alternative to finite-difference methods in the solution of partial differential initial-value problems. Large-scale symbolic algebra manipulation systems can be used to generate such approximations for a very general class of problems. The use of operator derivatives keeps the method from being limited to ordinary power series. The procedure is applied to the

F. C. Gey; M. B. Lesser

1969-01-01

322

Retinoblastoma protein functions as a molecular switch determining white versus brown adipocyte differentiation  

Microsoft Academic Search

Adipocyte precursor cells give raise to two major cell populations with different physiological roles: white and brown adipocytes. Here we demonstrate that the retinoblastoma protein (pRB) regulates white vs. brown adipocyte differentiation. Functional inactivation of pRB in wild-type mouse embryo fibroblasts (MEFs) and white preadipocytes by expression of simian virus 40 large T antigen results in the expression of the

Jacob B. Hansen; Claus Jørgensen; Rasmus K. Petersen; Philip Hallenborg; Rita de Matteis; Hans A. Bøye; Natasa Petrovic; Sven Enerbäck; Jan Nedergaard; Saverio Cinti; Hein Te Riele; Karsten Kristiansen

2004-01-01

323

Differential Item Functioning of Pathological Gambling Criteria: An Examination of Gender, Race\\/Ethnicity, and Age  

Microsoft Academic Search

This study tested for the presence of differential item functioning (DIF) in DSM-IV Pathological Gambling Disorder (PGD) criteria\\u000a based on gender, race\\/ethnicity and age. Using a nationally representative sample of adults from the National Epidemiologic\\u000a Survey on Alcohol and Related Conditions (NESARC), indicating current gambling (n = 10,899), Multiple Indicator-Multiple Cause (MIMIC) models tested for DIF, controlling for income, education, and marital

Paul SaccoLuis; Luis R. Torres; Renee M. Cunningham-Williams; Carol Woods; G. Jay Unick

2011-01-01

324

Finite-difference models of ordinary differential equations - Influence of denominator functions  

NASA Technical Reports Server (NTRS)

This paper discusses the influence on the solutions of finite-difference schemes of using a variety of denominator functions in the discrete modeling of the derivative for any ordinary differential equation. The results obtained are a consequence of using a generalized definition of the first derivative. A particular example of the linear decay equation is used to illustrate in detail the various solution possibilities that can occur.

Mickens, Ronald E.; Smith, Arthur

1990-01-01

325

Squamous cell carcinoma cells differentially stimulate NK cell effector functions: the role of IL18  

Microsoft Academic Search

Tumor cells stimulate natural killer (NK) cell effector functions, but the regulation of cytokine secretion and cytolysis is incompletely understood. We tested whether oral and pharyngeal squamous cell carcinoma cell lines differentially stimulated NK cell interferon-n (IFN-n) secretion and cytolysis using a clone of the NK-92-transformed human NK cell line, NK92.35. SCC-4 and SCC-25 cells, but not FaDu or Cal

Mikel B. Moore; Zoya B. Kurago; Colleen A. Fullenkamp; Charles T. Lutz

2003-01-01

326

A non-parametric Bayesian diagnostic for detecting differential item functioning in IRT models  

Microsoft Academic Search

Differential item functioning (DIF) in tests and multi-item surveys occurs when a lack of conditional independence exists\\u000a between the response to one or more items and membership to a particular group, given equal levels of proficiency. We develop\\u000a an approach to detecting DIF in the context of item response theory (IRT) models based on computing a diagnostic which is\\u000a the

Mark E. Glickman; Pradipta Seal; Susan V. Eisen

2009-01-01

327

Functional and Molecular Differentiation of the Dopamine System Induced by Neonatal Denervation  

Microsoft Academic Search

JOYCE, J. N., P. A. FROHNA AND B. S. NEAL-BELIVEAU. Functional and molecular differentiation of the dopamine system induced by neonatal denervation. NEUROSCI BIOBEHAV REV 20(3)453–486, 1996.—The administration of the neurotoxin 6-hydroxydopamine (6-OHDA) to damage the mesostriatal dopamine (DA) system in the neonate results in different neurochemical and behavioral consequences as compared to lesions made in adulthood. There have been

JEFFREY N. JOYCE; PAUL A. FROHNA; BETHANY S. NEAL-BELIVEAU

1996-01-01

328

The DIF-Free-Then-DIF Strategy for the Assessment of Differential Item Functioning  

ERIC Educational Resources Information Center

The DIF-free-then-DIF (DFTD) strategy consists of two steps: (a) select a set of items that are the most likely to be DIF-free and (b) assess the other items for DIF (differential item functioning) using the designated items as anchors. The rank-based method together with the computer software IRTLRDIF can select a set of DIF-free polytomous items…

Wang, Wen-Chung; Shih, Ching-Lin; Sun, Guo-Wei

2012-01-01

329

Differential item functioning (DIF) analyses of health-related quality of life instruments using logistic regression  

Microsoft Academic Search

BACKGROUND: Differential item functioning (DIF) methods can be used to determine whether different subgroups respond differently to particular items within a health-related quality of life (HRQoL) subscale, after allowing for overall subgroup differences in that scale. This article reviews issues that arise when testing for DIF in HRQoL instruments. We focus on logistic regression methods, which are often used because

Neil W Scott; Peter M Fayers; Neil K Aaronson; Andrew Bottomley; Alexander de Graeff; Mogens Groenvold; Chad Gundy; Michael Koller; Morten A Petersen; Mirjam AG Sprangers

2010-01-01

330

Characterizing regulatory and functional differentiation between maize mesophyll and bundle sheath cells by transcriptomic analysis.  

PubMed

To study the regulatory and functional differentiation between the mesophyll (M) and bundle sheath (BS) cells of maize (Zea mays), we isolated large quantities of highly homogeneous M and BS cells from newly matured second leaves for transcriptome profiling by RNA sequencing. A total of 52,421 annotated genes with at least one read were found in the two transcriptomes. Defining a gene with more than one read per kilobase per million mapped reads as expressed, we identified 18,482 expressed genes; 14,972 were expressed in M cells, including 53 M-enriched transcription factor (TF) genes, whereas 17,269 were expressed in BS cells, including 214 BS-enriched TF genes. Interestingly, many TF gene families show a conspicuous BS preference in expression. Pathway analyses reveal differentiation between the two cell types in various functional categories, with the M cells playing more important roles in light reaction, protein synthesis and folding, tetrapyrrole synthesis, and RNA binding, while the BS cells specialize in transport, signaling, protein degradation and posttranslational modification, major carbon, hydrogen, and oxygen metabolism, cell division and organization, and development. Genes coding for several transporters involved in the shuttle of C(4) metabolites and BS cell wall development have been identified, to our knowledge, for the first time. This comprehensive data set will be useful for studying M/BS differentiation in regulation and function. PMID:22829318

Chang, Yao-Ming; Liu, Wen-Yu; Shih, Arthur Chun-Chieh; Shen, Meng-Ni; Lu, Chen-Hua; Lu, Mei-Yeh Jade; Yang, Hui-Wen; Wang, Tzi-Yuan; Chen, Sean C-C; Chen, Stella Maris; Li, Wen-Hsiung; Ku, Maurice S B

2012-09-01

331

Assessing impact of differential symptom functioning on post-traumatic stress disorder (PTSD) diagnosis.  

PubMed

This article explores the generalizability of the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) diagnostic criteria for post-traumatic stress disorder (PTSD) to various subpopulations. Besides identifying the differential symptom functioning (also referred to as differential item functioning [DIF]) related to various background variables such as gender, marital status and educational level, this study emphasizes the importance of evaluating the impact of DIF on population inferences as made in health surveys and clinical trials, and on the diagnosis of individual patients. Using a sample from the National Comorbidity Study-Replication (NCS-R), four symptoms for gender, one symptom for marital status, and three symptoms for educational level were significantly flagged as DIF, but their impact on diagnosis was fairly small. We conclude that the DSM-IV diagnostic criteria for PTSD do not produce substantially biased results in the investigated subpopulations, and there should be few reservations regarding their use. Further, although the impact of DIF (i.e. the influence of differential symptom functioning on diagnostic results) was found to be quite small in the current study, we recommend that diagnosticians always perform a DIF analysis of various subpopulations using the methodology presented here to ensure the diagnostic criteria is valid in their own studies. Copyright © 2014 John Wiley & Sons, Ltd. PMID:24436035

He, Qiwei; Glas, Cees A W; Veldkamp, Bernard P

2014-06-01

332

Spatial congregation of STAT binding directs selective nuclear architecture during T-cell functional differentiation.  

PubMed

Higher-order genome organization shows tissue-specific patterns. However, functional relevance and the mechanisms shaping the genome architecture are poorly understood. Here we report a profound shift from promiscuous to highly selective genome organization that accompanies the effector lineage choice of differentiating T cells. As multipotent naive cells receive antigenic signals and commit to a T helper (Th) pathway, the genome-wide contacts of a lineage-specific cytokine locus are preferentially enriched for functionally relevant genes. Despite the establishment of divergent interactomes and global reprogramming of transcription in Th1 versus Th2, the overall expression status of the contact genes is surprisingly similar between the two lineages. Importantly, during differentiation, the genomic contacts are retained and strengthened precisely at DNA binding sites of the specific lineage-determining STAT transcription factor. In cells from the specific STAT knock-out mouse, the signature cytokine locus is unable to shed the promiscuous contacts established in the naive T cells, indicating the importance of genomic STAT binding. Altogether, the global aggregation of STAT binding loci from genic and nongenic regions highlights a new role for differentiation-promoting transcription factors in direct specification of higher-order nuclear architecture through interacting with regulatory regions. Such subnuclear environments have significant implications for efficient functioning of the mature effector lymphocytes. PMID:23212947

Hakim, Ofir; Sung, Myong-Hee; Nakayamada, Shingo; Voss, Ty C; Baek, Songjoon; Hager, Gordon L

2013-03-01

333

Spatial congregation of STAT binding directs selective nuclear architecture during T-cell functional differentiation  

PubMed Central

Higher-order genome organization shows tissue-specific patterns. However, functional relevance and the mechanisms shaping the genome architecture are poorly understood. Here we report a profound shift from promiscuous to highly selective genome organization that accompanies the effector lineage choice of differentiating T cells. As multipotent naive cells receive antigenic signals and commit to a T helper (Th) pathway, the genome-wide contacts of a lineage-specific cytokine locus are preferentially enriched for functionally relevant genes. Despite the establishment of divergent interactomes and global reprogramming of transcription in Th1 versus Th2, the overall expression status of the contact genes is surprisingly similar between the two lineages. Importantly, during differentiation, the genomic contacts are retained and strengthened precisely at DNA binding sites of the specific lineage-determining STAT transcription factor. In cells from the specific STAT knock-out mouse, the signature cytokine locus is unable to shed the promiscuous contacts established in the naive T cells, indicating the importance of genomic STAT binding. Altogether, the global aggregation of STAT binding loci from genic and nongenic regions highlights a new role for differentiation-promoting transcription factors in direct specification of higher-order nuclear architecture through interacting with regulatory regions. Such subnuclear environments have significant implications for efficient functioning of the mature effector lymphocytes.

Hakim, Ofir; Sung, Myong-Hee; Nakayamada, Shingo; Voss, Ty C.; Baek, Songjoon; Hager, Gordon L.

2013-01-01

334

Functional differentiation of midbrain neurons from human cord blood-derived induced pluripotent stem cells  

PubMed Central

Introduction Human induced pluripotent stem cells (hiPSCs) offer great promise for regenerative therapies or in vitro modelling of neurodegenerative disorders like Parkinson’s disease. Currently, widely used cell sources for the generation of hiPSCs are somatic cells obtained from aged individuals. However, a critical issue concerning the potential clinical use of these iPSCs is mutations that accumulate over lifetime and are transferred onto iPSCs during reprogramming which may influence the functionality of cells differentiated from them. The aim of our study was to establish a differentiation strategy to efficiently generate neurons including dopaminergic cells from human cord blood-derived iPSCs (hCBiPSCs) as a juvenescent cell source and prove their functional maturation in vitro. Methods The differentiation of hCBiPSCs was initiated by inhibition of transforming growth factor-? and bone morphogenetic protein signaling using the small molecules dorsomorphin and SB 431542 before final maturation was carried out. hCBiPSCs and differentiated neurons were characterized by immunocytochemistry and quantitative real time-polymerase chain reaction. Since functional investigations of hCBiPSC-derived neurons are indispensable prior to clinical applications, we performed detailed analysis of essential ion channel properties using whole-cell patch-clamp recordings and calcium imaging. Results A Sox1 and Pax6 positive neuronal progenitor cell population was efficiently induced from hCBiPSCs using a newly established differentiation protocol. Neuronal progenitor cells could be further maturated into dopaminergic neurons expressing tyrosine hydroxylase, the dopamine transporter and engrailed 1. Differentiated hCBiPSCs exhibited voltage-gated ion currents, were able to fire action potentials and displayed synaptic activity indicating synapse formation. Application of the neurotransmitters GABA, glutamate and acetylcholine induced depolarizing calcium signal changes in neuronal cells providing evidence for the excitatory effects of these ligand-gated ion channels during maturation in vitro. Conclusions This study demonstrates for the first time that hCBiPSCs can be used as a juvenescent cell source to generate a large number of functional neurons including dopaminergic cells which may serve for the development of novel regenerative treatment strategies.

2014-01-01

335

Pax6 controls the expression of critical genes involved in pancreatic {alpha} cell differentiation and function.  

PubMed

The paired box homeodomain Pax6 is crucial for endocrine cell development and function and plays an essential role in glucose homeostasis. Indeed, mutations of Pax6 are associated with diabetic phenotype. Importantly, homozygous mutant mice for Pax6 are characterized by markedly decreased ? and ? cells and absent ? cells. To better understand the critical role that Pax6 exerts in glucagon-producing cells, we developed a model of primary rat ? cells. To study the transcriptional network of Pax6 in adult and differentiated ? cells, we generated Pax6-deficient primary rat ? cells and glucagon-producing cells, using either specific siRNA or cells expressing constitutively a dominant-negative form of Pax6. In primary rat ? cells, we confirm that Pax6 controls the transcription of the Proglucagon and processing enzyme PC2 genes and identify three new target genes coding for MafB, cMaf, and NeuroD1/Beta2, which are all critical for Glucagon gene transcription and ? cell differentiation. Furthermore, we demonstrate that Pax6 directly binds and activates the promoter region of the three genes through specific binding sites and that constitutive expression of a dominant-negative form of Pax6 in glucagon-producing cells (InR1G9) inhibits the activities of the promoters. Finally our results suggest that the critical role of Pax6 action on ? cell differentiation is independent of those of Arx and Foxa2, two transcription factors that are necessary for ? cell development. We conclude that Pax6 is critical for ? cell function and differentiation through the transcriptional control of key genes involved in glucagon gene transcription, proglucagon processing, and ? cell differentiation. PMID:20592023

Gosmain, Yvan; Marthinet, Eric; Cheyssac, Claire; Guérardel, Audrey; Mamin, Aline; Katz, Liora S; Bouzakri, Karim; Philippe, Jacques

2010-10-22

336

Drosophila E-Cadherin Functions in Hematopoietic Progenitors to Maintain Multipotency and Block Differentiation  

PubMed Central

A fundamental question in stem cell biology concerns the regulatory strategies that control the choice between multipotency and differentiation. Drosophila blood progenitors or prohemocytes exhibit key stem cell characteristics, including multipotency, quiescence, and niche dependence. As a result, studies of Drosophila hematopoiesis have provided important insights into the molecular mechanisms that control these processes. Here, we show that E-cadherin is an important regulator of prohemocyte fate choice, maintaining prohemocyte multipotency and blocking differentiation. These functions are reminiscent of the role of E-cadherin in mammalian embryonic stem cells. We also show that mis-expression of E-cadherin in differentiating hemocytes disrupts the boundary between these cells and undifferentiated prohemocytes. Additionally, upregulation of E-cadherin in differentiating hemocytes increases the number of intermediate cell types expressing the prohemocyte marker, Patched. Furthermore, our studies indicate that the Drosophila GATA transcriptional co-factor, U-shaped, is required for E-cadherin expression. Consequently, E-cadherin is a downstream target of U-shaped in the maintenance of prohemocyte multipotency. In contrast, we showed that forced expression of the U-shaped GATA-binding partner, Serpent, repressed E-cadherin expression and promoted lamellocyte differentiation. Thus, U-shaped may maintain E-cadherin expression by blocking the inhibitory activity of Serpent. Collectively, these observations suggest that GATA:FOG complex formation regulates E-cadherin levels and, thereby, the choice between multipotency and differentiation. The work presented in this report further defines the molecular basis of prohemocyte cell fate choice, which will provide important insights into the mechanisms that govern stem cell biology.

Gao, Hongjuan; Wu, Xiaorong; Fossett, Nancy

2013-01-01

337

Age-related Differential Item Functioning for the Patient-Reported Outcomes Information System (PROMIS(R)) Physical Functioning Items  

PubMed Central

Purpose To evaluate the equivalence of the PROMIS® wave 1 physical functioning item bank, by age (50 years or older versus 18-49). Materials and methods A total of 114 physical functioning items with 5 response choices were administered to English- (n=1504) and Spanish-language (n=640) adults. Item frequencies, means and standard deviations, item-scale correlations, and internal consistency reliability were estimated. Differential Item Functioning (DIF) by age was evaluated. Results Thirty of the 114 items were fagged for DIF based on an R-squared of 0.02 or above criterion. The expected total score was higher for those respondents who were 18-49 than those who were 50 or older. Conclusions Those who were 50 years or older versus 18-49 years old with the same level of physical functioning responded differently to 30 of the 114 items in the PROMIS® physical functioning item bank. This study yields essential information about the equivalence of the physical functioning items in older versus younger individuals.

Paz, Sylvia H; Spritzer, Karen L; Morales, Leo S; Hays, Ron D

2013-01-01

338

Cation induced differential effect on structural and functional properties of Mycobacterium tuberculosis ?-Isopropylmalate synthase  

PubMed Central

Background ?-isopropylmalate synthase (Mt?IPMS), an enzyme that catalyzes the first committed step of the leucine biosynthetic pathway of Mycobacterium tuberculosis is a potential drug target for the anti-tuberculosis drugs. Cations induce differential effect of activation and inhibition of Mt?IPMS. To date no concrete mechanism for such an opposite effect of similarly charged cations on the functional activity of enzyme has been presented. Results Effect of cations on the structure and function of the Mt?IPMS has been studied in detail. The studies for the first time demonstrate that different cations interact specifically at different sites in the enzyme and modulate the enzyme structure differentially. The inhibitors Zn2+ and Cd2+ ions interact directly with the catalytic domain of the enzyme and induce unfolding/denaturation of the domain. The activator K+ also interacts with the catalytic TIM barrel domain however, it does not induce any significant effect on the enzyme structure. Studies with isolated catalytic TIM barrel domain showed that it can carry out the catalytic function on its own but probably requires the non-catalytic C-terminal domain for optimum functioning. An important observation was that divalent cations induce significant interaction between the regulatory and the catalytic domain of Mt?IPMS thus inducing structural cooperativity in the enzyme. This divalent cation induced structural cooperativity might result in modulation of activity of the catalytic domain by regulatory domain. Conclusion The studies for the first time demonstrate that different cations bind at different sites in the enzyme leading to their differential effects on the structure and functional activity of the enzyme.

Singh, Kulwant; Bhakuni, Vinod

2007-01-01

339

?-Catenin Functions Pleiotropically in Differentiation and Tumorigenesis in Mouse Embryo-Derived Stem Cells  

PubMed Central

The canonical Wnt/?-catenin signaling pathway plays a crucial role in the maintenance of the balance between proliferation and differentiation throughout embryogenesis and tissue homeostasis. ?-Catenin, encoded by the Ctnnb1 gene, mediates an intracellular signaling cascade activated by Wnt. It also plays an important role in the maintenance of various types of stem cells including adult stem cells and cancer stem cells. However, it is unclear if ?-catenin is required for the derivation of mouse embryo-derived stem cells. Here, we established ?-catenin-deficient (?-cat?/?) mouse embryo-derived stem cells and showed that ?-catenin is not essential for acquiring self-renewal potential in the derivation of mouse embryonic stem cells (ESCs). However, teratomas formed from embryo-derived ?-cat?/? ESCs were immature germ cell tumors without multilineage differentiated cell types. Re-expression of functional ?-catenin eliminated their neoplastic, transformed phenotype and restored pluripotency, thereby rescuing the mutant ESCs. Our findings demonstrate that ?-catenin has pleiotropic effects in ESCs; it is required for the differentiation of ESCs and prevents them from acquiring tumorigenic character. These results highlight ?-catenin as the gatekeeper in differentiation and tumorigenesis in ESCs.

Okumura, Noriko; Akutsu, Hidenori; Sugawara, Tohru; Miura, Takumi; Takezawa, Youki; Hosoda, Akihiro; Yoshida, Keiichi; Ichida, Justin K.; Yamada, Mitsutoshi; Hamatani, Toshio; Kuji, Naoaki; Miyado, Kenji; Yoshimura, Yasunori; Umezawa, Akihiro

2013-01-01

340

Dynamic Rewiring of the Drosophila Retinal Determination Network Switches Its Function from Selector to Differentiation  

PubMed Central

Organ development is directed by selector gene networks. Eye development in the fruit fly Drosophila melanogaster is driven by the highly conserved selector gene network referred to as the “retinal determination gene network,” composed of approximately 20 factors, whose core comprises twin of eyeless (toy), eyeless (ey), sine oculis (so), dachshund (dac), and eyes absent (eya). These genes encode transcriptional regulators that are each necessary for normal eye development, and sufficient to direct ectopic eye development when misexpressed. While it is well documented that the downstream genes so, eya, and dac are necessary not only during early growth and determination stages but also during the differentiation phase of retinal development, it remains unknown how the retinal determination gene network terminates its functions in determination and begins to promote differentiation. Here, we identify a switch in the regulation of ey by the downstream retinal determination genes, which is essential for the transition from determination to differentiation. We found that central to the transition is a switch from positive regulation of ey transcription to negative regulation and that both types of regulation require so. Our results suggest a model in which the retinal determination gene network is rewired to end the growth and determination stage of eye development and trigger terminal differentiation. We conclude that changes in the regulatory relationships among members of the retinal determination gene network are a driving force for key transitions in retinal development.

Sansores-Garcia, Leticia; Jusiak, Barbara; Halder, Georg; Mardon, Graeme

2013-01-01

341

Functions of Heterogeneous Nuclear Ribonucleoproteins in Stem Cell Potency and Differentiation  

PubMed Central

Stem cells possess huge importance in developmental biology, disease modelling, cell replacement therapy, and tissue engineering in regenerative medicine because they have the remarkable potential for self-renewal and to differentiate into almost all the cell types in the human body. Elucidation of molecular mechanisms regulating stem cell potency and differentiation is essential and critical for extensive application. Heterogeneous nuclear ribonucleoproteins (hnRNPs) are modular proteins consisting of RNA-binding motifs and auxiliary domains characterized by extensive and divergent functions in nucleic acid metabolism. Multiple roles of hnRNPs in transcriptional and posttranscriptional regulation enable them to be effective gene expression regulators. More recent findings show that hnRNP proteins are crucial factors implicated in maintenance of stem cell self-renewal and pluripotency and cell differentiation. The hnRNPs interact with certain sequences in target gene promoter regions to initiate transcription. In addition, they recognize 3?UTR or 5?UTR of specific gene mRNA forming mRNP complex to regulate mRNA stability and translation. Both of these regulatory pathways lead to modulation of gene expression that is associated with stem cell proliferation, cell cycle control, pluripotency, and committed differentiation.

Chen, Qishan; Jin, Min; Zhu, Jianhua; Zhang, Li

2013-01-01

342

Suppression of AP1 Transcription Factor Function in Keratinocyte Suppresses Differentiation  

PubMed Central

Our previous study shows that inhibiting activator protein one (AP1) transcription factor function in murine epidermis, using dominant-negative c-jun (TAM67), increases cell proliferation and delays differentiation. To understand the mechanism of action, we compare TAM67 impact in mouse epidermis and in cultured normal human keratinocytes. We show that TAM67 localizes in the nucleus where it forms TAM67 homodimers that competitively interact with AP1 transcription factor DNA binding sites to reduce endogenous jun and fos factor binding. Involucrin is a marker of keratinocyte differentiation that is expressed in the suprabasal epidermis and this expression requires AP1 factor interaction at the AP1-5 site in the promoter. TAM67 interacts competitively at this site to reduce involucrin expression. TAM67 also reduces endogenous c-jun, junB and junD mRNA and protein level. Studies with c-jun promoter suggest that this is due to reduced transcription of the c-jun gene. We propose that TAM67 suppresses keratinocyte differentiation by interfering with endogenous AP1 factor binding to regulator elements in differentiation-associated target genes, and by reducing endogenous c-jun factor expression.

Han, Bingshe; Rorke, Ellen A.; Adhikary, Gautam; Chew, Yap Ching; Xu, Wen; Eckert, Richard L.

2012-01-01

343

RotundRacGAP Functions with Ras during Spermatogenesis and Retinal Differentiation in Drosophila melanogaster  

PubMed Central

Our analysis of rotund (rn) null mutations in Drosophila melanogaster revealed that deletion of the rn locus affects both spermatid and retinal differentiation. In the male reproductive system, the absence of RnRacGAP induced small testes, empty seminal vesicles, short testicular cysts, reduced amounts of interspermatid membrane, the absence of individualization complexes, and incomplete mitochondrial condensation. Flagellar growth continued within the short rn null cysts to produce large bulbous terminations of intertwined mature flagella. Organization of the retina was also severely perturbed as evidenced by grossly misshapen ommatidia containing reduced numbers of photoreceptor and pigment cells. These morphological phenotypes were rescued by genomic rnRacGAP transgenes, demonstrating that RnRacGAP function is critical to spermatid and retinal differentiation. The testicular phenotypes were suppressed by heterozygous hypomorphic mutations in the Dras1 and drk genes, indicating cross talk between RacGAP-regulated signaling and that of the Ras pathway. The observed genetic interactions are consistent with a model in which Rac signaling is activated by Ras and negatively regulated by RnRacGAP during spermatid differentiation. RnRacGAP and Ras cross talk also operated during retinal differentiation; however, while the heterozygous hypomorphic drk mutation continued to act as a suppressor of the rn null mutation, the heterozygous hypomorphic Dras1 mutation induced novel retinal phenotypes.

Bergeret, Evelyne; Pignot-Paintrand, Isabelle; Guichard, Annabel; Raymond, Karine; Fauvarque, Marie-Odile; Cazemajor, Michel; Griffin-Shea, Ruth

2001-01-01

344

Differentiation and functional connection of vascular elements in compatible and incompatible pear/quince internode micrografts.  

PubMed

Micrografts of internodes excised from in vitro grown pear plants (Pyrus communis L. cv. 'Bosc' (B) and cv. 'Butirra Hardy' (BH)) and quince (Cydonia oblonga Mill. East Malling clone C (EMC)), were cultured aseptically to test the effectiveness of their functional vascular reconnection in relation to incompatibility-compatibility relationships that these genotypes exhibit in the field. The incompatible heterograft (B/EMC) showed a marked delay in internode cohesion compared with the autografts (both B/B and BH/BH) and the compatible heterograft (BH/EMC). Even when fused, the translocation of [14C]-sorbitol from upper to lower internode was lower in B/EMC micrografts than in the other combinations. Epifluorescence studies performed with carboxyfluorescin, a specific phloem probe, indicated that the limited translocation was caused by a delay in the establishment of functional phloem continuity between the two internodes. In the B/EMC combination, new differentiated tracheary elements (TE) in the parenchyma tissue at the graft interface between the two internodes were not detected until 30 days after grafting, whereas in the BH/EMC heterograft and both autografts, new xylem connections appeared to cross the interface 20 days after grafting. Immunohistochemical detection (terminal nick-end labeling assay) of the number of cells undergoing nuclear DNA fragmentation at the graft interface confirmed that the limited and delayed TE differentiation in B/EMC heterografts was associated with a decrease in the activity of programmed cell death processes involved in the differentiation of TE. PMID:16105809

Espen, Luca; Cocucci, Maurizio; Sacchi, Gian Attilio

2005-11-01

345

Rotating waves in parabolic functional differential equations with rotation of spatial argument and time delay  

NASA Astrophysics Data System (ADS)

The parabolic functional differential equation is considered on the circle [0, 2?]. Here, D > 0, T > 0, K > 0, and ? ? (0, 1). Such equations arise in the modeling of nonlinear optical systems with a time delay T > 0 and a spatial argument rotated by an angle ? ? [0, 2?) in the nonlocal feedback loop in the approximation of a thin circular layer. The goal of this study is to describe spatially inhomogeneous rotating-wave solutions bifurcating from a homogeneous stationary solution in the case of a Andronov-Hopf bifurcation. The existence of such waves is proved by passing to a moving coordinate system, which makes it possible to reduce the problem to the construction of a nontrivial solution to a periodic boundary value problem for a stationary delay differential equation. The existence of rotating waves in an annulus resulting from a Andronov-Hopf bifurcation is proved, and the leading coefficients in the expansion of the solution in powers of a small parameter are obtained. The conditions for the stability of waves are derived by constructing a normal form for the Andronov-Hopf bifurcation for the functional differential equation under study.

Razgulin, A. V.; Romanenko, T. E.

2013-11-01

346

Phorbol myristate acetate differentiates human adipose-derived mesenchymal stem cells into functional cardiogenic cells.  

PubMed

To achieve effective regeneration of injured myocardium, it is important to find physiological way of improving the cardiogenic differentiation of stem cells. Previous studies demonstrated that cardiomyocytes from bone marrow-derived mesenchymal stem cells (BMSCs) activated with phorbolmyristate acetate (PMA), a protein kinase C (PKC) activator, restore electromechanical function in infarcted rat hearts. In this study, we investigated the effect of PMA on cardiogenic differentiation of adipose-derived MSCs (ASCs) for clinical applications. To confirm the effect of PMA, ASCs treated with 1?M PMA were grown for nine days. The expression of cardiac-specific markers (cardiac troponin T, myosin light chain, myosin heavy chain) in PMA-treated MSCs was demonstrated by immunocytochemistry. Alhough few ?(1A) receptors exist in ASCs, ?(1)-adrenergic receptor subtypes were preferentially expressed in PMA-treated ASCs. Moreover, expression of the ?-adrenergic and muscarinic receptors increased in PMA-treated ASCs compared to normal cells. The mRNA levels of Ca(2+)-related factors (SERCA 2a; sarcoplasmic reticulum Ca(2+)-ATPase, LTCC; L-type Ca(2+) channel) in treated ASCs were similar to the levels in cardiomyocytes. Following the transplantation of chemically activated cardiogenic ASCs into infarcted myocardium, histological analysis showed that infarct size, interstitial fibrosis, and apoptotic index were markedly decreased and cardiac function was restored. In conclusion, PMA might induce the cardiogenic differentiation of human ASCs as well as BMSCs. This result suggests successful use of human ASCs in cardiac regeneration therapy. PMID:22809507

Chang, Woochul; Lim, Soyeon; Song, Byeong-Wook; Lee, Chang Youn; Park, Moon-Seo; Chung, Young-An; Yoon, Cheesoon; Lee, Se-Yeon; Ham, Onju; Park, Jun-Hee; Choi, Eunhyun; Maeng, Lee-So; Hwang, Ki-Chul

2012-08-10

347

Neuron-NG2 Cell Synapses: Novel Functions for Regulating NG2 Cell Proliferation and Differentiation  

PubMed Central

NG2 cells are a population of CNS cells that are distinct from neurons, mature oligodendrocytes, astrocytes, and microglia. These cells can be identified by their NG2 proteoglycan expression. NG2 cells have a highly branched morphology, with abundant processes radiating from the cell body, and express a complex set of voltage-gated channels, AMPA/kainate, and GABA receptors. Neurons notably form classical and nonclassical synapses with NG2 cells, which have varied characteristics and functions. Neuron-NG2 cell synapses could fine-tune NG2 cell activities, including the NG2 cell cycle, differentiation, migration, and myelination, and may be a novel potential therapeutic target for NG2 cell-related diseases, such as hypoxia-ischemia injury and periventricular leukomalacia. Furthermore, neuron-NG2 cell synapses may be correlated with the plasticity of CNS in adulthood with the synaptic contacts passing onto their progenies during proliferation, and synaptic contacts decrease rapidly upon NG2 cell differentiation. In this review, we highlight the characteristics of classical and nonclassical neuron-NG2 cell synapses, the potential functions, and the fate of synaptic contacts during proliferation and differentiation, with the emphasis on the regulation of the NG2 cell cycle by neuron-NG2 cell synapses and their potential underlying mechanisms.

Yang, Qian-Kun; Xiong, Jia-Xiang; Yao, Zhong-Xiang

2013-01-01

348

Combinatorial flexibility of cytokine function during human T helper cell differentiation.  

PubMed

In an inflammatory microenvironment, multiple cytokines may act on the same target cell, creating the possibility for combinatorial interactions. How these may influence the system-level function of a given cytokine is unknown. Here we show that a single cytokine, interferon (IFN)-alpha, can generate multiple transcriptional signatures, including distinct functional modules of variable flexibility, when acting in four cytokine environments driving distinct T helper cell differentiation programs (Th0, Th1, Th2 and Th17). We provide experimental validation of a chemokine, cytokine and antiviral modules differentially induced by IFN-? in Th1, Th2 and Th17 environments. Functional impact is demonstrated for the antiviral response, with a lesser IFN-?-induced protection to HIV-1 and HIV-2 infection in a Th17 context. Our results reveal that a single cytokine can induce multiple transcriptional and functional programs in different microenvironments. This combinatorial flexibility creates a previously unrecognized diversity of responses, with potential impact on disease physiopathology and cytokine therapy. PMID:24865484

Touzot, Maxime; Grandclaudon, Maximilien; Cappuccio, Antonio; Satoh, Takeshi; Martinez-Cingolani, Carolina; Servant, Nicolas; Manel, Nicolas; Soumelis, Vassili

2014-01-01

349

Helicobacter pylori hydrogenase accessory protein HypA and urease accessory protein UreG compete with each other for UreE recognition  

PubMed Central

Background The gastric pathogen Helicobacter pylori relies on nickel-containing urease and hydrogenase enzymes in order to colonize the host. Incorporation of Ni2+ into urease is essential for the function of the enzyme and requires the action of several accessory proteins, including the hydrogenase accessory proteins HypA and HypB and the urease accessory proteins UreE, UreF, UreG and UreH. Methods Optical biosensing methods (biolayer interferometry and plasmon surface resonance) were used to screen for interactions between HypA, HypB, UreE and UreG. Results Using both methods, affinity constants were found to be 5 nM and 13 nM for HypA–UreE and 8 µM and 14 µM for UreG-UreE. Neither Zn2+ nor Ni2+ had an effect on the kinetics or stability of the HypA–UreE complex. By contrast, addition of Zn2+, but not Ni2+, altered the kinetics and greatly increased the stability of the UreE–UreG complex, likely due in part to Zn2+-mediated oligomerization of UreE. Finally our results unambiguously show that HypA, UreE and UreG cannot form a heterotrimeric protein complex in vitro; instead, HypA and UreG compete with each other for UreE recognition. General significance Factors influencing the pathogen's nickel budget are important to understand pathogenesis and for future drug design.

Benoit, Stephane L.; McMurry, Jonathan L.; Hill, Stephanie A.; Maier, Robert J.

2014-01-01

350

Midbrain cues dictate differentiation of human dental pulp stem cells towards functional dopaminergic neurons.  

PubMed

Dental pulp originating from the neural crest is considered a better source of postnatal stem cells for cell-based therapies in neurodegenerative diseases. Dental Pulp Stem Cells (DPSCs) have been shown to differentiate into cell-types of cranial neural crest ontology; however, their ability to differentiate to functional neurons of the central nervous system remains to be studied. We hypothesized that midbrain cues might commit DPSCs to differentiate to functional dopaminergic cell-type. As expected, DPSCs in their naïve state spontaneously expressed early and mature neuronal markers like nestin, musashi12, ? tubulin III, and Map2ab. On exposure to midbrain cues (sonic hedgehog, fibroblast growth factor 8 and basic fibroblast growth factor), DPSCs showed upregulation of dopaminergic neuron-specific transcription factors Nuclear Receptor related protein 1 (Nurr1), Engrailed 1 (En1) and paired-like homeodomain transcription factor 3 (Pitx3) as revealed by real-time RT-PCR. Immunofluorescence and flow cytometry analysis showed enhanced expression of mature neuronal marker Map2ab and dopaminergic-neuronal markers [tyrosine hydroxylase (TH), En1, Nurr1, and Pitx3], with nearly 77% of the induced DPSCs positive for TH. Functional studies indicated that the induced DPSCs could secrete dopamine constitutively and upon stimulation with potassium chloride (KCl) and adenosine triphosphate (ATP), as measured by dopamine ELISA. Additionally, the induced DPSCs showed intracellular Ca(2+) influx in the presence of KCl, unlike control DPSCs. ATP-stimulated Ca(2+) influx was observed in control and induced DPSCs, but only the induced cells secreted dopamine. Our data clearly demonstrate for the first time that DPSCs in the presence of embryonic midbrain cues show efficient propensity towards functional dopaminergic cell-type. J. Cell. Physiol. 229: 1369-1377, 2014. © 2014 Wiley Periodicals, Inc. PMID:24477667

Kanafi, Mohammad; Majumdar, Debanjana; Bhonde, Ramesh; Gupta, Pawan; Datta, Indrani

2014-10-01

351

Urinary NGAL Levels Correlate with Differential Renal Function in Patients with Ureteropelvic Junction Obstruction Undergoing Pyeloplasty  

PubMed Central

Purpose: Recent investigations described the use of NGAL, a sensitive biomarker for kidney injury, in the setting of ureteropelvic junction obstruction. We prospectively evaluated urinary NGAL levels in the affected renal pelvis and bladder of children with ureteropelvic junction obstruction undergoing unilateral dismembered pyeloplasty. Our hypothesis was that higher NGAL in the kidney and bladder would correlate with decreased ipsilateral differential function. Materials and Methods: We performed a prospective cohort study in patients treated with unilateral dismembered pyeloplasty from 2010 to 2012. Urine was obtained intraoperatively from the bladder and obstructed renal pelvis. A control population of unaffected children was recruited to provide a voided bladder specimen. Bladder NGAL levels were compared between the study and control populations. We tested our study hypothesis by correlating bladder and renal pelvic NGAL levels with the differential renal function of the affected kidney. Results: A total of 61 patients with a median age at surgery of 1.62 years (range 0.12 to 18.7) were enrolled in the study. Median bladder NGAL was 18.6 ng/mg (range 1.4-1,650.8) and median renal pelvic NGAL was 26.2 ng/mg (range 1.2-18,034.5, p = 0.004). Median bladder NGAL was significantly higher than in controls (p = 0.004). The correlation of bladder and renal pelvic NGAL with differential renal function was r = ?0.359 (p = 0.004) and r = ?0.383 (p = 0.002), respectively. Conclusions: Bladder NGAL is increased in children with ureteropelvic junction obstruction. Renal pelvic and bladder normalized urinary NGAL levels correlate inversely with the relative function of the affected kidney in cases of unilateral ureteropelvic junction obstruction.

Cost, Nicholas G.; Noh, Paul H.; Devarajan, Prasad; Ivancic, Vesna; Reddy, Pramod P.; Minevich, Eugene; Bennett, Michael; Haffner, Christopher; Schulte, Marion; DeFoor, W. Robert

2014-01-01

352

Usefulness of acoustic studies on the differential diagnostics of organic and functional dysphonia.  

PubMed

Phoniatric and acoustic examinations were carried out in a group of 30 patients with dysphonia, including 15 with organic type and 15 with functional type. A complex phoniatric assessment offered the possibility to differentiate between these two groups of pathological voices. This was achieved also on the basis of acoustic analysis of the voice by extracting characteristics such as: formant frequency, Fo and its range, percentage of noise in the analysed verbal text, mean and maximum values of jitter. The possibility of differential diagnosis of these two different types of dysphonia in acoustic studies was confirmed by clinical examinations. The acoustic studies presented can be regarded as a new approach to a fast and sufficiently precise method in the screening diagnostics of dysphonia conditioned by growth of the vocal fold mass. PMID:2068930

Pruszewicz, A; Obrebowski, A; Swidzi?ski, P; Deme?ko, G; Wika, T; Wojciechowska, A

1991-01-01

353

Effect of RGD-functionalization and stiffness modulation of polyelectrolyte multilayer films on muscle cell differentiation  

PubMed Central

Skeletal muscle tissue engineering holds promise for the replacement of muscle due to an injury and for the treatment of muscle diseases. Although RGD substrates have been widely explored in tissue engineering, there is no study aimed at investigating the combined effects of RGD nanoscale presentation and matrix stiffness on myogenesis. In the present work, we use polyelectrolyte multilayer films made of poly(L-lysine) (PLL) and poly(L-glutamic) acid (PGA) as substrates of tunable stiffness that can be functionalized by a RGD adhesive peptide to investigate important events in myogenesis, including adhesion, migration, proliferation and differentiation. C2C12 myoblasts were used as cellular models. RGD presentation on soft films and increased film stiffness could both induce cell adhesion, but integrins involved in adhesion were different in case of soft and stiff films. Moreover, soft films with RGD peptide appeared to be the most appropriate substrate for myogenic differentiation while the stiff PLL/PGA films significantly induced cell migration, proliferation and inhibited myogenic differentiation. The ROCK kinase was found to be involved in myoblast response to the different films. Indeed, its inhibition was sufficient to rescue the differentiation on stiff films, but no significant changes were observed on stiff films with the RGD peptide. These results suggest that different signaling pathways may be activated depending on mechanical and biochemical properties of the multilayer films. This study emphasizes the superior advantage of the soft PLL/PGA films presenting the RGD peptide in terms of myogenic differentiation. This soft RGD-presenting film may be further used as coating of various polymeric scaffolds for muscle tissue engineering.

Gribova, Varvara; Gauthier-Rouviere, Cecile; Albiges-Rizo, Corinne; Auzely-Velty, Rachel; Picart, Catherine

2014-01-01

354

Mitochondrial biogenesis and energy production in differentiating murine stem cells: a functional metabolic study.  

PubMed

The significance of metabolic networks in guiding the fate of the stem cell differentiation is only beginning to emerge. Oxidative metabolism has been suggested to play a major role during this process. Therefore, it is critical to understand the underlying mechanisms of metabolic alterations occurring in stem cells to manipulate the ultimate outcome of these pluripotent cells. Here, using P19 murine embryonal carcinoma cells as a model system, the role of mitochondrial biogenesis and the modulation of metabolic networks during dimethyl sulfoxide (DMSO)-induced differentiation are revealed. Blue native polyacrylamide gel electrophoresis (BN-PAGE) technology aided in profiling key enzymes, such as hexokinase (HK) [EC 2.7.1.1], glucose-6-phosphate isomerase (GPI) [EC 5.3.1.9], pyruvate kinase (PK) [EC 2.7.1.40], Complex I [EC 1.6.5.3], and Complex IV [EC 1.9.3.1], that are involved in the energy budget of the differentiated cells. Mitochondrial adenosine triphosphate (ATP) production was shown to be increased in DMSO-treated cells upon exposure to the tricarboxylic acid (TCA) cycle substrates, such as succinate and malate. The increased mitochondrial activity and biogenesis were further confirmed by immunofluorescence microscopy. Collectively, the results indicate that oxidative energy metabolism and mitochondrial biogenesis were sharply upregulated in DMSO-differentiated P19 cells. This functional metabolic and proteomic study provides further evidence that modulation of mitochondrial energy metabolism is a pivotal component of the cellular differentiation process and may dictate the final destiny of stem cells. PMID:24350892

Han, Sungwon; Auger, Christopher; Thomas, Sean C; Beites, Crestina L; Appanna, Vasu D

2014-02-01

355

Effect of RGD functionalization and stiffness modulation of polyelectrolyte multilayer films on muscle cell differentiation.  

PubMed

Skeletal muscle tissue engineering holds promise for the replacement of muscle damaged by injury and for the treatment of muscle diseases. Although arginylglycylaspartic acid (RGD) substrates have been widely explored in tissue engineering, there have been no studies aimed at investigating the combined effects of RGD nanoscale presentation and matrix stiffness on myogenesis. In the present work we use polyelectrolyte multilayer films made of poly(L-lysine) (PLL) and poly(L-glutamic) acid (PGA) as substrates of tunable stiffness that can be functionalized by a RGD adhesive peptide to investigate important events in myogenesis, including adhesion, migration, proliferation and differentiation. C2C12 myoblasts were used as cellular models. RGD presentation on soft films and increasing film stiffness could both induce cell adhesion, but the integrins involved in adhesion were different in the case of soft and stiff films. Soft films with RGD peptide appeared to be the most appropriate substrate for myogenic differentiation, while the stiff PLL/PGA films induced significant cell migration and proliferation and inhibited myogenic differentiation. ROCK kinase was found to be involved in the myoblast response to the different films. Indeed, its inhibition was sufficient to rescue differentiation on stiff films, but no significant changes were observed on stiff films with the RGD peptide. These results suggest that different signaling pathways may be activated depending on the mechanical and biochemical properties of multilayer films. This study emphasizes the advantage of soft PLL/PGA films presenting the RGD peptide in terms of myogenic differentiation. This soft RGD-presenting film may be further used as a coating of various polymeric scaffolds for muscle tissue engineering. PMID:23261924

Gribova, Varvara; Gauthier-Rouvière, Cécile; Albigès-Rizo, Corinne; Auzely-Velty, Rachel; Picart, Catherine

2013-05-01

356

Full-length and truncated neurokinin-1 receptor expression and function during monocyte/macrophage differentiation  

PubMed Central

The substance P (SP)-preferring receptor neurokinin-1 receptor (NK-1R) has two forms: a full-length receptor consisting of 407 aa and a truncated receptor consisting of 311 aa. These two receptors differ in the length of the C terminus of NK-1R. We studied the undifferentiated and phorbol myristate acetate (PMA)-differentiated human monocyte/macrophage cell line THP-1 to investigate the expression and function of NK-1R. The expression of full-length and truncated NK-1R in this cell line was determined by using real-time PCR and immunofluorescence staining. Undifferentiated THP-1 cells expressed only truncated NK-1R. The differentiation of THP-1 cells with PMA to a macrophage-like phenotype resulted in the expression of full-length NK-1R, which was functionally accompanied by an SP (10?6 M)-induced Ca2+ increase. In contrast, the addition of SP (10?6 M) did not trigger Ca2+ response in undifferentiated THP-1 cells; however, SP did enhance the CCR5-preferring ligand RANTES (CCL5)-mediated Ca2+ increase. When a plasmid containing the full-length NK-1R was introduced into undifferentiated THP-1 cells, exposure to SP triggered Ca2+ increase, demonstrating that the full-length NK-1R is required for SP-induced Ca2+ increase. The NK-1R antagonist aprepitant (Emend, Merck) inhibited both the SP-induced Ca2+ increase in PMA-differentiated THP-1 cells and the SP priming effect on the CCL5-mediated Ca2+ increase, indicating that these effects are mediated through the full-length and truncated NK-1R, respectively. Taken together, these observations demonstrate that there are unique characteristics of NK-1R expression and NK-1R-mediated signaling between undifferentiated THP-1 cells and THP-1 cells differentiated to the macrophage phenotype.

Lai, J.-P.; Ho, W. Z.; Kilpatrick, L. E.; Wang, X.; Tuluc, F.; Korchak, H. M.; Douglas, S. D.

2006-01-01

357

Enolase 1 and calreticulin regulate the differentiation and function of mouse mast cells.  

PubMed

It has become widely accepted that the role of mast cells is not restricted to allergic processes. Thus, mast cells play an important role in innate and adaptive immune responses, but study of proteins related to differentiation of mast cells has not been done yet. Enolase 1 is a glycolytic enzyme expressed in most tissues and calreticulin, known as endoplasmic reticulum (ER) resident chaperon, has multifunctional responses. This study aimed to investigate the effects of these proteins on the differentiation and functions of mouse bone marrow-derived mast cells (BMMCs). To identify the target proteins related to the differentiation of BMMCs, we examined the protein expression pattern of BMMCs using 2-dimensional electrophoresis (2-DE) and MALDI-TOF analysis. Expressions of Fc?RI?, surface molecules (c-kit, CD40, CD40L, VCAM-1), tryptase, and cytokines were examined in BMMCs using FACS analysis, Western blot, and RT-PCR respectively. Enolase 1 and calreticulin were transfected into BMMCs, and [Ca(2+)]i levels were determined by confocal microscope, while amounts of TNF-? and LTs were measured by ELISA. Eight proteins were identified by proteomic analysis. Enolase and calreticulin siRNA transfection inhibited the expressions of Fc?RI?, surface molecules, tryptase, and cytokine mRNA, which are gradually enhanced during culture periods of BMMCs. Enolase 1 and calreticulin siRNA reduced the [Ca(2+)]i levels, amounts of total TNF-?, and the release of TNF-? and leukotrienes, all of which are increased in the BMMCs activated with antigen/antibody reaction. The data suggest that enolase 1 and calreticulin are important proteins in regulating the differentiation and functions of BMMCs. PMID:21803152

Ryu, Su Youn; Hong, Gwan Ui; Kim, Dae Yong; Ro, Jai Youl

2012-01-01

358

Short-time glucose exposure of embryonic carcinoma cells impairs their function as terminally differentiated cardiomyocytes.  

PubMed

The fetal and postnatal phenotype is influenced by developmental conditions experienced prenatally. Among prenatal development metabolic factors are of particular importance as they are supposed to predispose for pathophysiological alterations later in life and to pioneer functional impairment in senescence (metabolic programming). Till now the mechanisms of metabolic programming are not well understood. We have investigated various concentrations of glucose during differentiation of pluripotent P19 embryonic carcinoma cells (ECC) into cardiomyocytes. Undifferentiated P19 cells were exposed to 5mM (low), 25 mM (control), 40 mM or 100mM (high) glucose for 48 h during embryoid body (EB) formation, followed by plating and differentiation into cardiomyocytes in vitro with standard glucose supplementation (25 mM) for 10-15 days. The amount of cardiac clusters, the frequency of spontaneous beatings as well as the expression of metabolic and cardiac marker genes and their promoter methylation were measured. We observed a metabolic programming effect of glucose during cardiac differentiation. Whereas the number of beating clusters and the expression of the cardiac marker alpha myosin heavy chain (?-MHC) were comparable in all groups, the frequencies of beating clusters were significantly higher in the high glucose group compared to low glucose. However, neither the insulin receptor (IR) or insulin like growth factor 1 receptor (IGF1R) nor the metabolic gene glucose transporter 4 (GLUT4) were influenced in RNA expression or in promoter methylation. Our data indicate that a short time glucose stress during embryonic cell determination leads to lasting effects in terminally differentiated cell function. PMID:22405827

Knelangen, Julia M; Kurz, Randy; Schagdarsurengin, Undraga; Fischer, Bernd; Navarrete Santos, Anne

2012-04-01

359

Retinoblastoma protein functions as a molecular switch determining white versus brown adipocyte differentiation  

PubMed Central

Adipocyte precursor cells give raise to two major cell populations with different physiological roles: white and brown adipocytes. Here we demonstrate that the retinoblastoma protein (pRB) regulates white vs. brown adipocyte differentiation. Functional inactivation of pRB in wild-type mouse embryo fibroblasts (MEFs) and white preadipocytes by expression of simian virus 40 large T antigen results in the expression of the brown fat-specific uncoupling protein 1 (UCP-1) in the adipose state. Retinoblastoma gene-deficient (Rb–/–) MEFs and stem cells, but not the corresponding wild-type cells, differentiate into adipocytes with a gene expression pattern and mitochondria content resembling brown adipose tissue. pRB-deficient MEFs exhibit an increased expression of the Forkhead transcription factor Foxc2 and its target gene cAMP-dependent protein kinase regulatory subunit RI?, resulting in increased cAMP sensitivity. Suppression of cAMP-dependent protein kinase activity in Rb–/–MEFs blocked the brown adipocyte-like gene expression pattern without affecting differentiation per se. Immunohistochemical studies revealed that pRB is present in the nuclei of white but not brown adipocyte precursor cells at a developmental stage where both cell types begin to accumulate lipid and brown adipocytes express UCP-1. Furthermore, pRB rapidly undergoes phosphorylation upon cold-induced neodifferentiation and up-regulation of UCP-1 expression in brown adipose tissue. Finally, down-regulation of pRB expression accompanies transdifferentiation of white into brown adipocytes in response to ?3-adrenergic receptor agonist treatment. We propose that pRB acts as a molecular switch determining white vs. brown adipogenesis, suggesting a previously uncharacterized function of this key cell cycle regulator in adipocyte lineage commitment and differentiation.

Hansen, Jacob B.; J?rgensen, Claus; Petersen, Rasmus K.; Hallenborg, Philip; De Matteis, Rita; B?ye, Hans A.; Petrovic, Natasa; Enerback, Sven; Nedergaard, Jan; Cinti, Saverio; Riele, Hein te; Kristiansen, Karsten

2004-01-01

360

Incorporation of functionalized gold nanoparticles into nanofibers for enhanced attachment and differentiation of mammalian cells  

PubMed Central

Background Electrospun nanofibers have been widely used as substrata for mammalian cell culture owing to their structural similarity to natural extracellular matrices. Structurally consistent electrospun nanofibers can be produced with synthetic polymers but require chemical modification to graft cell-adhesive molecules to make the nanofibers functional. Development of a facile method of grafting functional molecules on the nanofibers will contribute to the production of diverse cell type-specific nanofiber substrata. Results Small molecules, peptides, and functionalized gold nanoparticles were successfully incorporated with polymethylglutarimide (PMGI) nanofibers through electrospinning. The PMGI nanofibers functionalized by the grafted AuNPs, which were labeled with cell-adhesive peptides, enhanced HeLa cell attachment and potentiated cardiomyocyte differentiation of human pluripotent stem cells. Conclusions PMGI nanofibers can be functionalized simply by co-electrospinning with the grafting materials. In addition, grafting functionalized AuNPs enable high-density localization of the cell-adhesive peptides on the nanofiber. The results of the present study suggest that more cell type-specific synthetic substrata can be fabricated with molecule-doped nanofibers, in which diverse functional molecules are grafted alone or in combination with other molecules at different concentrations.

2012-01-01

361

Differentiation of multipotent adult progenitor cells into functional endothelial and smooth muscle cells.  

PubMed

Stem cells are not only a promising in vivo tool for the treatment of diseases characterized by irreversible tissue damage, but can also be exploited as in vitro systems to study the conditions required to generate molecularly and functionally defined cell types. Constructing functional arteries with luminal arterial endothelial cells stabilized by a medial layer of smooth muscle cells is one of the challenges of regenerative medicine. This unit describes the conditions for generating endothelial and smooth muscle cells from multipotent adult progenitor cells (MAPCs). It elaborates on the importance of certain parameters, e.g., quality control of the stem cell population used, serum lot variations, seeding density, use of appropriate cytokines, critical to obtaining high differentiation efficiencies. It further focuses on the molecular and functional characterization of the obtained cell types. PMID:18432970

Luttun, Aernout; Ross, Jeffrey J; Verfaillie, Catherine; Aranguren, Xabier L; Prósper, Felipe

2006-12-01

362

[Application of the new diagnostic tests for vertigo. Differentiated analysis of vestibular function].  

PubMed

Due to the development of new methods such as the vestibular evoked myogenic potential and the video head impulse tests, clinical vestibular diagnostic procedures are currently in an era of change. The spectrum of available techniques renders a specific, quantitative and objective analysis of vestibular reflexes possible for the first time. Moreover, a combination of different methods permits the assessment of different functional areas of the vestibular receptor. In addition to a topological diagnosis, the concept of a differentiated analysis of vestibular receptor function includes evaluation of frequency-specific functional areas (dynamic frequency analysis) and monitoring of temporal changes (time-dependent diagnostics). Consequently, the overall outcome of physiological tests can be viewed from a new perspective. This enables a comprehensive assessment of vestibulopathies in clinical practice and furthers the understanding of these disorders. PMID:23913192

Walther, L E

2013-09-01

363

Accessory tragus: a possible sign of Goldenhar syndrome.  

PubMed

The accessory tragus is a relatively common benign congenital anomaly. The tragus is a cartilaginous projection that normally occurs anterior to the external auditory meatus. Although aberrancy of the tragus may occur in isolation and is exclusively derived from the first branchial arch, it may occasionally signal a defect in the first or second branchial arches. Thus it may be a sign of other syndromes, such as oculoauricularvertebral dysplasia (Goldenhar syndrome). In fact, accessory tragus is a constant feature of this syndrome and may be associated with other syndromes. Accessory tragi are polypoid and should be distinguished from acrochordon (skin tags), as the shave excision commonly employed for skin tags may expose cartilage and cause slow healing or chondrodermatitis nodularis chronica helicis. PMID:21916271

Rankin, James S; Schwartz, Robert A

2011-08-01

364

HES6-1 and HES6-2 Function through Different Mechanisms during Neuronal Differentiation  

PubMed Central

Background Notch signalling plays a central role in the mechanisms regulating neuronal differentiation in the vertebrate nervous system. The transcriptional repressors encoded by Hes genes are the main effectors of this pathway, acting in neural progenitors during the lateral inhibition process to repress proneural genes and inhibit differentiation. However, Hes6 genes seem to behave differently: they are expressed in differentiating neurons and facilitate the activity of proneural genes in promoting neurogenesis. Still, the molecular mechanisms underlying this unique function of Hes6 genes are not yet understood. Methodology/Principal Findings Here, we identify two subgroups of Hes6 genes that seem conserved in most vertebrate species and characterize a novel Hes6 gene in chicken: cHes6-1. The embryonic expression pattern of cHes6-1 suggests roles for this gene in the formation of the pancreas, nervous system and in the generation of body asymmetry. We show that cHes6-1 is negatively regulated by Notch signalling in the developing embryonic spinal cord and in pancreatic progenitors, but requires Notch for the observed asymmetric expression at the lateral mesoderm. Functional studies by ectopic expression in the chick embryonic neural tube revealed that cHES6-1 up-regulates the expression of cDelta1 and cHes5 genes, in contrast with overexpression of cHES6-2, which represses the same genes. We show that this activity of cHES6-2 is dependent on its capacity to bind DNA and repress transcription, while cHES6-1 seems to function by sequestering other HES proteins and inhibit their activity as transcriptional repressors. Conclusions/Significance Our results indicate that the two chick HES6 proteins act at different phases of neuronal differentiation, contributing to the progression of neurogenesis by different mechanisms: while cHES6-2 represses the transcription of Hes genes, cHES6-1 acts later, sequestering HES proteins. Together, the two cHES6 proteins progressively shut down the Notch-mediated progenitor program and ensure that neuronal differentiation can proceed.

Vilas-Boas, Filipe; Henrique, Domingos

2010-01-01

365

MYC2 Differentially Modulates Diverse Jasmonate-Dependent Functions in Arabidopsis[W  

PubMed Central

The Arabidopsis thaliana basic helix-loop-helix Leu zipper transcription factor (TF) MYC2/JIN1 differentially regulates jasmonate (JA)-responsive pathogen defense (e.g., PDF1.2) and wound response (e.g., VSP) genes. In this study, genome-wide transcriptional profiling of wild type and mutant myc2/jin1 plants followed by functional analyses has revealed new roles for MYC2 in the modulation of diverse JA functions. We found that MYC2 negatively regulates Trp and Trp-derived secondary metabolism such as indole glucosinolate biosynthesis during JA signaling. Furthermore, MYC2 positively regulates JA-mediated resistance to insect pests, such as Helicoverpa armigera, and tolerance to oxidative stress, possibly via enhanced ascorbate redox cycling and flavonoid biosynthesis. Analyses of MYC2 cis binding elements and expression of MYC2-regulated genes in T-DNA insertion lines of a subset of MYC2–regulated TFs suggested that MYC2 might modulate JA responses via differential regulation of an intermediate spectrum of TFs with activating or repressing roles in JA signaling. MYC2 also negatively regulates its own expression, and this may be one of the mechanisms used in fine-tuning JA signaling. Overall, these results provide new insights into the function of MYC2 and the transcriptional coordination of the JA signaling pathway.

Dombrecht, Bruno; Xue, Gang Ping; Sprague, Susan J.; Kirkegaard, John A.; Ross, John J.; Reid, James B.; Fitt, Gary P.; Sewelam, Nasser; Schenk, Peer M.; Manners, John M.; Kazan, Kemal

2007-01-01

366

Inactivation of Stat5 in Mouse Mammary Epithelium during Pregnancy Reveals Distinct Functions in Cell Proliferation, Survival, and Differentiation  

Microsoft Academic Search

This study explored the functions of the signal transducers and activators of transcription 5a and 5b (referred to as Stat5 here) during different stages of mouse mammary gland development by using conditional gene inactivation. Mammary gland morphogenesis includes cell specification, proliferation and differentiation during pregnancy, cell survival and maintenance of differentiation throughout lactation, and cell death during involution. Stat5 is

Yongzhi Cui; Greg Riedlinger; Keiko Miyoshi; Wei Tang; Cuiling Li; Chu-Xia Deng; Gertraud W. Robinson; Lothar Hennighausen

2004-01-01

367

Atypical course of the rare accessory extensor carpi radialis muscle.  

PubMed Central

The description of a bilaterally well developed, bicipital and bipennate accessory extensor carpi radialis muscle is reported. The muscle arose between the origins of the long and short radial carpal extensor muscles and inserted by 2 tendons into the 1st 2 metacarpal bones. The ulnar tendinous insertion was simultaneously the origin of abductor pollicis brevis. Both heads of the accessory extensor carpi radialis muscle were innervated by a branch of the deep branch of the radial nerve. The present observation supplements our knowledge on variations in the antebrachial and carpal regions, which are important in hand surgery. Images Fig. 1

Khaledpour, C; Schindelmeiser, J

1994-01-01

368

Either main or accessory olfactory system signaling can mediate the rewarding effects of estrous female chemosignals in sexually naive male mice.  

PubMed

A long-held view has been that interest of male mice in female body odors reflects an activation of reward circuits in the male brain following their detection by the vomeronasal organ (VNO) and processing via the accessory olfactory system. We found that adult, sexually naive male mice acquired a conditioned place preference (CPP) after repeatedly receiving estrous female urine on the nose and being placed in an initially nonpreferred chamber with soiled estrous bedding on the floor. CPP was not acquired in control mice that received saline on the nose before being placed in a nonpreferred chamber with clean bedding. Robust acquisition of a CPP using estrous female odors as the reward persisted in separate groups of mice in which VNO-accessory olfactory function was disrupted by bilateral lesioning of the accessory olfactory bulb (AOB) or in which main olfactory function was disrupted by zinc sulfate lesions of the main olfactory epithelium (MOE). By contrast, no CPP was acquired for estrous odors in males that received combined AOB and MOE lesions. Either the main or the accessory olfactory system suffices to mediate the rewarding effects of estrous female odors in the male mouse, even in the absence of prior mating experience. The main olfactory system is part of the circuitry that responds to chemosignals involved in motivated behavior, a role that may be particularly important for humans who lack a functional accessory olfactory system. PMID:23978150

Korzan, Wayne J; Freamat, Mihael; Johnson, Adam G; Cherry, James A; Baum, Michael J

2013-10-01

369

CD 19 function in central and peripheral B-cell development  

Microsoft Academic Search

Although the B-cell antigen receptor (BCR) factors most prominently in the maintenance and differentiation of mature B cells,\\u000a it is now appreciated that co-receptor molecules can positively or negatively modulate signals through the BCR. Co-receptors\\u000a are functionally defined as modifiers of BCR engagement and signal transuction, and are distinct from other accessory molecules\\u000a that act independently to regulate B-cell growth.

Christopher J. Del Nagro; Dennis C. Otero; Amy N. Anzelon; Sidne A. Omori; Ravi V. Kolla; Robert C. Rickert

2005-01-01

370

Sensing the immune microenvironment to coordinate T cell metabolism, differentiation & function  

PubMed Central

Mounting an adaptive immune response is bioenergetically demanding. As a result, T cell activation coincides with profound changes in cellular metabolism that must be coordinated with instructive signals from cytokine and costimulatory receptors to generate an immune response. Studies examining the intimate link between metabolism and immune function have revealed that different types of T cells have distinct metabolic profiles. Data is emerging that place mTOR, an evolutionarily conserved serine-threonine kinase, as a central integrator of these processes. In this review, we will discuss the role of mTOR in determining both CD4 and CD8 T cell metabolism, differentiation, and trafficking.

Heikamp, Emily B.; Powell, Jonathan D.

2013-01-01

371

A lattice Boltzmann model with an amending function for simulating nonlinear partial differential equations  

NASA Astrophysics Data System (ADS)

This paper proposes a lattice Boltzmann model with an amending function for one-dimensional nonlinear partial differential equations (NPDEs) in the form ut + ?uux + ?unux + ?uxx + ?uxxx + ?uxxxx = 0. This model is different from existing models because it lets the time step be equivalent to the square of the space step and derives higher accuracy and nonlinear terms in NPDEs. With the Chapman-Enskog expansion, the governing evolution equation is recovered correctly from the continuous Boltzmann equation. The numerical results agree well with the analytical solutions.

Chen, Lin-Jie; Ma, Chang-Feng

2010-01-01

372

Bipolar and borderline patients display differential patterns of functional connectivity among resting state networks.  

PubMed

Bipolar disorder (BD) and borderline personality (BPD) disorder share clinical features such as emotional lability and poor interpersonal functioning but the course of illness and treatment differs in these groups, which suggests that the underlying neurobiology of BD and BPD is likely to be different. Understanding the neural mechanisms behind the pathophysiology of BD and BPD will facilitate accurate diagnosis and inform the administration of targeted treatment. Since deficits in social cognition or emotion regulation or in the self-referential processing system can give rise to these clinical features, and impairment in these domains have been observed in both patient groups, functional connectivity within and between networks subserving these processes during resting was investigated using functional magnetic resonance imaging. Data were acquired from 16 patients with BD, 14 patients with BPD, and 13 healthy controls (HC) and functional connectivity strength was correlated with scores using the Difficulties in Emotion Regulation Scale. Functional network connectivity (FNC) patterns differentiated BD and BPD patients from HC. In BD, FNC was increased while in BPD it was decreased. In BD impaired FNC was evident primarily among networks involved in self-referential processing while in BPD it also involved the emotion regulatory network. Impaired FNC displayed an association with impulsivity in BPD and emotional clarity and emotional awareness in BD. This study shows that BD and BPD can perhaps be differentiated using resting state FNC approach and that the neural mechanisms underpinning overlapping symptoms discernibly differ between the groups. These findings provide a potential platform for elucidating the targeted effects of psychological interventions in both disorders. PMID:24793833

Das, Pritha; Calhoun, Vince; Malhi, Gin S

2014-09-01

373

Clonal lymphoid progenitor cell lines expressing the BCR/ABL oncogene retain full differentiative function.  

PubMed Central

The early stages of hematopoiesis have been difficult to study due to problems in obtaining homogeneous populations of progenitor cells that retain both self-renewal and differentiative capacities. We have developed an in vitro system in which transformation of murine bone-marrow cells with the BCR/ABL oncogene, a gene associated with stem-cell leukemias, leads to the outgrowth of clonal lines that have an early lymphoid progenitor cell phenotype. The progenitor cells retain immunoglobulin heavy and light chain genes in a germ-line configuration. These cells give rise in vitro to pre-B cells that have diverse diversity-joining (D-J) region rearrangements, and on transfer to mice with severe combined immune deficiency, differentiate to surface IgM+, immunoglobulin-secreting B cells that respond to T-cell help and function in an antigen-specific fashion. Although their growth is stimulated by BCR/ABL, the progenitor cells depend for continued growth on a stromal cell-derived soluble factor distinct from the pre-B-cell growth factor, interleukin 7. These findings show that BCR/ABL can promote proliferation of an early hematopoietic progenitor cell without preventing its differentiation. This system provides a means of studying the complete B-cell developmental process from clonal progenitor cell to end-stage plasma cell. Images

Scherle, P A; Dorshkind, K; Witte, O N

1990-01-01

374

Differential PAX3 functions in normal skin melanocytes and melanoma cells  

SciTech Connect

Highlights: {yields} PAX3 retains embryonic roles in adult melanocytes and melanoma cells. {yields} Promotes 'stem' cell-like phenotype via NES and SOX9 in both cells types. {yields} Regulates melanoma and melanocyte migration through MCAM and CSPG4. {yields} PAX3 regulates melanoma but not melanocyte proliferation via TPD52. {yields} Regulates melanoma cell (but not melanocyte) survival via BCL2L1 and PTEN. -- Abstract: The PAX3 transcription factor is the key regulator of melanocyte development during embryogenesis and is also frequently found in melanoma cells. While PAX3 is known to regulate melanocyte differentiation, survival, proliferation and migration during development, it is not clear if its function is maintained in adult melanocytes and melanoma cells. To clarify this we have assessed which genes are targeted by PAX3 in these cells. We show here that similar to its roles in development, PAX3 regulates complex differentiation networks in both melanoma cells and melanocytes, in order to maintain cells as 'stem' cell-like (via NES and SOX9). We show also that mediators of migration (MCAM and CSPG4) are common to both cell types but more so in melanoma cells. By contrast, PAX3-mediated regulation of melanoma cell proliferation (through TPD52) and survival (via BCL2L1 and PTEN) differs from that in melanocytes. These results suggest that by controlling cell proliferation, survival and migration as well as maintaining a less differentiated 'stem' cell like phenotype, PAX3 may contribute to melanoma development and progression.

Medic, Sandra [School of Exercise, Biomedical and Health Sciences, Edith Cowan University, Perth, WA (Australia)] [School of Exercise, Biomedical and Health Sciences, Edith Cowan University, Perth, WA (Australia); Rizos, Helen [Westmead Institute for Cancer Research and Melanoma Institute of Australia, University of Sydney at Westmead Millennium Institute, Westmead, NSW (Australia)] [Westmead Institute for Cancer Research and Melanoma Institute of Australia, University of Sydney at Westmead Millennium Institute, Westmead, NSW (Australia); Ziman, Mel, E-mail: m.ziman@ecu.edu.au [School of Exercise, Biomedical and Health Sciences, Edith Cowan University, Perth, WA (Australia) [School of Exercise, Biomedical and Health Sciences, Edith Cowan University, Perth, WA (Australia); School of Pathology and Laboratory Medicine, University of Western Australia, Perth, WA (Australia)

2011-08-12

375

Functional analysis of inter-individual transcriptome differential expression in pig longissimus muscle.  

PubMed

Selection of pigs for increased meat production or improved meat quality changes muscle mass and muscle composition. This will be related to transcriptome expression profile changes in muscle tissue, generating inter-individual differences. This study investigated the differentially expressed genes in the transcriptome profiles of the longissimus muscle of 75 Large White-Duroc cross sows and castrates. The use of a common reference design enabled to investigate the inter-individual transcriptome expression profile differences between the animals as compared with the means of all animals. The aim of the study was to identify the biological processes related to these inter-individual differences. It was expected that these processes underlie the selection effects. In total, 908 transcripts were differentially expressed. Among them, 762 were mainly downregulated and 146 were mainly upregulated. Gene Ontology and Pathways analyses indicated that the differentially expressed genes belong to three groups of processes involved in protein synthesis and amino acid-protein metabolism, energy metabolism and muscle-specific structure and activity processes. Comparing the functional biological analysis results with previously reported data suggested that the protein synthesis, energy metabolism and muscle-specific structure would contribute to meat production and the meat quality. PMID:23317067

Zhao, S; Hulsegge, B; Harders, F L; Bossers, R; Keuning, E; Hoekman, A J W; Hoving-Bolink, R; te Pas, M F W

2013-02-01

376

Local and Global Techniques for the Tracking of Periodic Solutions of Parameter-Dependent Functional Differential Equations.  

National Technical Information Service (NTIS)

This project was a continuation of an ongoing study of numerical/analytic techniques for the identification of periodic solutions to functional differential equations. The techniques developed apply to very general classes of equations, and have been impl...

H. W. Stech

1988-01-01

377

Differential Abundance of Microbial Functional Groups along the Elevation Gradient from the Coast to the Luquillo Mountains  

EPA Science Inventory

Microbial communities respond to multiple abiotic and biotic factors that change along elevation gradients. We compare changes in microbial community composition in soil and review previous research on differential abundance of microbial functional groups along an elevation gradi...

378

21 CFR 884.4150 - Bipolar endoscopic coagulator-cutter and accessories.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 2010-04-01 false Bipolar endoscopic coagulator-cutter and accessories...Gynecological Surgical Devices § 884.4150 Bipolar endoscopic coagulator-cutter and accessories. (a) Identification. A bipolar endoscopic...

2010-04-01

379

21 CFR 884.4150 - Bipolar endoscopic coagulator-cutter and accessories.  

Code of Federal Regulations, 2010 CFR

...2009-04-01 2009-04-01 false Bipolar endoscopic coagulator-cutter and accessories...Gynecological Surgical Devices § 884.4150 Bipolar endoscopic coagulator-cutter and accessories. (a) Identification. A bipolar endoscopic...

2009-04-01

380

22 CFR 121.8 - End-items, components, accessories, attachments, parts, firmware, software and systems.  

Code of Federal Regulations, 2013 CFR

...accessories, attachments, parts, firmware, software and systems. 121.8 Section 121...accessories, attachments, parts, firmware, software and systems. (a) An end-item...is not limited to circuits into which software has been programmed. (f)...

2013-04-01

381

29 CFR 1919.28 - Unit proof tests-cranes and gear accessory thereto.  

Code of Federal Regulations, 2010 CFR

...proof tests-cranes and gear accessory thereto. 1919...OF LABOR (CONTINUED) GEAR CERTIFICATION Certification...Tests and Proof Loads; Heat Treatment; Competent Persons ...proof testsâcranes and gear accessory...

2010-07-01

382

29 CFR 1919.27 - Unit proof tests-winches, derricks and gear accessory thereto.  

Code of Federal Regulations, 2010 CFR

...tests-winches, derricks and gear accessory thereto. 1919...OF LABOR (CONTINUED) GEAR CERTIFICATION Certification...Tests and Proof Loads; Heat Treatment; Competent Persons ...winches, derricks and gear accessory thereto....

2009-07-01

383

29 CFR 1919.28 - Unit proof tests-cranes and gear accessory thereto.  

Code of Federal Regulations, 2010 CFR

...proof tests-cranes and gear accessory thereto. 1919...OF LABOR (CONTINUED) GEAR CERTIFICATION Certification...Tests and Proof Loads; Heat Treatment; Competent Persons ...proof testsâcranes and gear accessory...

2009-07-01

384

29 CFR 1919.27 - Unit proof tests-winches, derricks and gear accessory thereto.  

Code of Federal Regulations, 2010 CFR

...tests-winches, derricks and gear accessory thereto. 1919...OF LABOR (CONTINUED) GEAR CERTIFICATION Certification...Tests and Proof Loads; Heat Treatment; Competent Persons ...winches, derricks and gear accessory thereto....

2010-07-01

385

Study of Reduction of Accessory Horsepower Requirements. Seventh Quarterly Progress Report.  

National Technical Information Service (NTIS)

Progress is reported for a program whose objective is to evolve and define an accessory drive system that will minimize system power consumption of driven accessories on an internal combustion engine in a passenger automobile. Although the primary goal is...

1976-01-01

386

21 CFR 878.4820 - Surgical instrument motors and accessories/attachments.  

Code of Federal Regulations, 2010 CFR

...devices intended for use during surgical procedures to provide power to operate various accessories or attachments to cut hard tissue or bone and soft tissue. Accessories or attachments may include a bur, chisel (osteotome), dermabrasion...

2010-04-01

387

21 CFR 878.4820 - Surgical instrument motors and accessories/attachments.  

Code of Federal Regulations, 2010 CFR

...devices intended for use during surgical procedures to provide power to operate various accessories or attachments to cut hard tissue or bone and soft tissue. Accessories or attachments may include a bur, chisel (osteotome), dermabrasion...

2009-04-01

388

Computational methods for analysis of cellular functions and pathways collectively targeted by differentially expressed microRNA  

Microsoft Academic Search

This report presents computational methods of analysis of cellular processes, functions, and pathways affected by differentially expressed microRNA, a statistical basis of the gene enrichment analysis method, a modification of enrichment analysis method accounting for combinatorial targeting of Gene Ontology categories by multiple miRNAs and examples of the global functional profiling of predicted targets of differentially expressed miRNAs in cancer.

Yuriy Gusev

2008-01-01

389

Allogeneic mesenchymal stem cells restore cardiac function in chronic ischemic cardiomyopathy via trilineage differentiating capacity  

PubMed Central

The mechanism(s) underlying cardiac reparative effects of bone marrow-derived mesenchymal stem cells (MSC) remain highly controversial. Here we tested the hypothesis that MSCs regenerate chronically infarcted myocardium through mechanisms comprising long-term engraftment and trilineage differentiation. Twelve weeks after myocardial infarction, female swine received catheter-based transendocardial injections of either placebo (n = 4) or male allogeneic MSCs (200 million; n = 6). Animals underwent serial cardiac magnetic resonance imaging, and in vivo cell fate was determined by co-localization of Y-chromosome (Ypos) cells with markers of cardiac, vascular muscle, and endothelial lineages. MSCs engrafted in infarct and border zones and differentiated into cardiomyocytes as ascertained by co-localization with GATA-4, Nkx2.5, and ?-sarcomeric actin. In addition, Ypos MSCs exhibited vascular smooth muscle and endothelial cell differentiation, contributing to large and small vessel formation. Infarct size was reduced from 19.3 ± 1.7% to 13.9 ± 2.0% (P < 0.001), and ejection fraction (EF) increased from 35.0 ± 1.7% to 41.3 ± 2.7% (P < 0.05) in MSC but not placebo pigs over 12 weeks. This was accompanied by increases in regional contractility and myocardial blood flow (MBF), particularly in the infarct border zone. Importantly, MSC engraftment correlated with functional recovery in contractility (R = 0.85, P < 0.05) and MBF (R = 0.76, P < 0.01). Together these findings demonstrate long-term MSC survival, engraftment, and trilineage differentiation following transplantation into chronically scarred myocardium. MSCs are an adult stem cell with the capacity for cardiomyogenesis and vasculogenesis which contribute, at least in part, to their ability to repair chronically scarred myocardium.

Quevedo, Henry C.; Hatzistergos, Konstantinos E.; Oskouei, Behzad N.; Feigenbaum, Gary S.; Rodriguez, Jose E.; Valdes, David; Pattany, Pradip M.; Zambrano, Juan P.; Hu, Qinghua; McNiece, Ian; Heldman, Alan W.; Hare, Joshua M.

2009-01-01

390

Sox3 Functions in a Cell-Autonomous Manner to Regulate Spermatogonial Differentiation in Mice  

PubMed Central

The X-linked Sox3 gene encodes a member of the Sry high-mobility group box proteins, which play a role in many developmental processes including neurogenesis and testis development. This study further examined the role of Sox3 in spermatogenesis. Males without Sox3 expression exhibited a similar number of germ cell nuclear antigen-positive germ cells at 1, 5, and 10 d postpartum (dpp) compared to their wild-type littermates, but there was significant germ cell depletion by 20 dpp. However, spermatogenesis later resumed and postmeiotic germ cells were observed by 56 dpp. The VasaCre transgene was used to generate a germ cell-specific deletion of Sox3. The phenotype of the germ cell-specific Sox3 knockout was similar to the ubiquitous knockout, indicating an intrinsic role for Sox3 in germ cells. The residual germ cells in 20 dpp Sox3?/Y males were spermatogonia as indicated by their expression of neurogenin3 but not synaptonemal complex protein 3, which is expressed within cells undergoing meiosis. RNA expression analyses corroborated the histological analyses and revealed a gradual transition from relatively increased expression of spermatogonia genes at 20 dpp to near normal expression of genes characteristic of undifferentiated and meiotic germ cells by 84 dpp. Fluorescent-activated cell sorting of undifferentiated (ret tyrosine kinase receptor positive) and differentiated (kit receptor tyrosine kinase-positive) spermatogonia revealed depletion of differentiated spermatogonia in Sox3?/Y tubules. These results indicate that Sox3 functions in an intrinsic manner to promote differentiation of spermatogonia in prepubertal mice but it is not required for ongoing spermatogenesis in adults. The Sox3?/Y males provide a unique model for studying the mechanism of germ cell differentiation in prepubertal testes.

Laronda, Monica M.

2011-01-01

391

HIV-1 Nef Sequence and Functional Compartmentalization in the Gut Is Not Due to Differential Cytotoxic T Lymphocyte Selective Pressure  

PubMed Central

The gut is the largest lymphoid organ in the body and a site of active HIV-1 replication and immune surveillance. The gut is a reservoir of persistent infection in some individuals with fully suppressed plasma viremia on combination antiretroviral therapy (cART) although the cause of this persistence is unknown. The HIV-1 accessory protein Nef contributes to persistence through multiple functions including immune evasion and increasing infectivity. Previous studies showed that Nef’s function is shaped by cytotoxic T lymphocyte (CTL) responses and that there are distinct populations of Nef within tissue compartments. We asked whether Nef’s sequence and/or function are compartmentalized in the gut and how compartmentalization relates to local CTL immune responses. Primary nef quasispecies from paired plasma and sigmoid colon biopsies from chronically infected subjects not on therapy were sequenced and cloned into Env? Vpu? pseudotyped reporter viruses. CTL responses were mapped by IFN-? ELISpot using expanded CD8+ cells from blood and gut with pools of overlapping peptides covering the entire HIV proteome. CD4 and MHC Class I Nef-mediated downregulation was measured by flow cytometry. Multiple tests indicated compartmentalization of nef sequences in 5 of 8 subjects. There was also compartmentalization of function with MHC Class I downregulation relatively well preserved, but significant loss of CD4 downregulation specifically by gut quasispecies in 5 of 7 subjects. There was no compartmentalization of CTL responses in 6 of 8 subjects, and the selective pressure on quasispecies correlated with the magnitude CTL response regardless of location. These results demonstrate that Nef adapts via diverse pathways to local selective pressures within gut mucosa, which may be predominated by factors other than CTL responses such as target cell availability. The finding of a functionally distinct population within gut mucosa offers some insight into how HIV-1 may persist in the gut despite fully suppressed plasma viremia on cART.

Lewis, Martha J.; Frohnen, Patricia; Ibarrondo, F. Javier; Reed, Diane; Iyer, Varun; Ng, Hwee L.; Elliott, Julie; Yang, Otto O.; Anton, Peter

2013-01-01

392

Generalized Solutions of Functional Differential Inclusions with a Volterra Multi-Valued Mapping  

NASA Astrophysics Data System (ADS)

We consider the initial value problem for a functional differential inclusion with a Volterra multi-valued mapping that is not necessarily decomposable in L1n[a,b]. In this case the methods known for multi-valued mappings cannot even be applied to the solvability problem of the perturbed inclusion. Also fundamental properties of the solution sets (the density principle and ``bang-bang'' principle) do not hold any more. The situation cannot be improved even if the mapping in question is continuous. In this connection the concept of the decomposable hull of a set is introduced. Using this concept, we define a generalized solution of such a problem and study its properties. We have proved that standard results on local existence and continuation of a generalized solution remain true. The question on the estimation of a generalized solution with respect to a given absolutely continuous function is studied. The density principle is proved for the generalized solutions.

Machina, Anna; Bulgakov, Aleksander

2007-09-01

393

Executive functioning in children with an Autism Spectrum Disorder: can we differentiate within the spectrum?  

PubMed

The aim of this study was to investigate whether children with high-functioning autism (HFA), Asperger's syndrome (AS), and pervasive developmental disorder not otherwise specified (PDDNOS) can be differentiated from each other and from normal controls on their neurocognitive executive functioning (EF) profile. Children with HFA and AS showed the most EF deficits. The EF profile of the PDDNOS group was more disturbed that the normal control group, but was less disturbed than the profile of the HFA and AS groups. Little difference was found between the three PDD subtypes with respect to EF. This study supports the view that executive dysfunctioning plays an important role in autism. The usefulness of a distinction between different PDD subtypes was not demonstrated. PMID:16575542

Verté, Sylvie; Geurts, Hilde M; Roeyers, Herbert; Oosterlaan, Jaap; Sergeant, Joseph A

2006-04-01

394

Differential Effect of Calsequestrin Ablation on Structure and Function of Fast and Slow Skeletal Muscle Fibers  

PubMed Central

We compared structure and function of EDL and Soleus muscles in adult (4–6?m) mice lacking both Calsequestrin (CASQ) isoforms, the main SR Ca2+-binding proteins. Lack of CASQ induced ultrastructural alterations in ~30% of Soleus fibers, but not in EDL. Twitch time parameters were prolonged in both muscles, although tension was not reduced. However, when stimulated for 2?sec at 100?hz, Soleus was able to sustain contraction, while in EDL active tension declined by 70–80%. The results presented in this paper unmask a differential effect of CASQ1&2 ablation in fast versus slow fibers. CASQ is essential in EDL to provide large amount of Ca2+ released from the SR during tetanic stimulation. In contrast, Soleus deals much better with lack of CASQ because slow fibers require lower Ca2+ amounts and slower cycling to function properly. Nevertheless, Soleus suffers more severe structural damage, possibly because SR Ca2+ leak is more pronounced.

Paolini, Cecilia; Quarta, Marco; D'Onofrio, Laura; Reggiani, Carlo; Protasi, Feliciano

2011-01-01

395

Differential contributions of executive and episodic memory functions to problem solving in younger and older adults.  

PubMed

The relationship of higher order problem solving to basic neuropsychological processes likely depends on the type of problems to be solved. Well-defined problems (e.g., completing a series of errands) may rely primarily on executive functions. Conversely, ill-defined problems (e.g., navigating socially awkward situations) may, in addition, rely on medial temporal lobe (MTL) mediated episodic memory processes. Healthy young (N = 18; M = 19; SD = 1.3) and old (N = 18; M = 73; SD = 5.0) adults completed a battery of neuropsychological tests of executive and episodic memory function, and experimental tests of problem solving. Correlation analyses and age group comparisons demonstrated differential contributions of executive and autobiographical episodic memory function to well-defined and ill-defined problem solving and evidence for an episodic simulation mechanism underlying ill-defined problem solving efficacy. Findings are consistent with the emerging idea that MTL-mediated episodic simulation processes support the effective solution of ill-defined problems, over and above the contribution of frontally mediated executive functions. Implications for the development of intervention strategies that target preservation of functional independence in older adults are discussed. PMID:24044692

Vandermorris, Susan; Sheldon, Signy; Winocur, Gordon; Moscovitch, Morris

2013-11-01

396

Osteopontin Splice Variants Differentially Exert Clinicopathological Features and Biological Functions in Gastric Cancer  

PubMed Central

Purpose: Gastric cancer (GC) remains a leading cause of death worldwide, and an elevated expression of osteopontin (OPN) may correlate with its poor survival. Alternative splicing of OPN can result in three isoforms, OPN-a, OPN-b and OPN-c. The aim of our current study is to examine the expression pattern and biological functions of OPN splice variants in GC. Methods: Firstly, we evaluated the expression of OPN splice variants in 7 gastric cell lines, 101 pairs of GC tissues and their adjacent non-tumor tissues by Quantative real-time PCR (QT-PCR). Gain-of-function experiments were subsequently performed to determine their diverse roles in malignant behaviors of GC. Besides, their differential effects on the regulation of crucial downstream molecules were further explored in the anti-apoptotic and pro-metastatic process. Results: We found that OPN-b is the dominant kind of OPN isoform in GC cell lines. Although the expression levels of three variants were all elevated in GC tissues, increased OPN-b or OPN-c expression could correlate with clinicopathological features. Functional analyses further showed that OPN-b most strongly promoted GC cell survival possibly by regulation of Bcl-2 family proteins and CD44v expressions. Moreover, OPN-c most effectively stimulated GC metastatic activity by increasing secretion of MMP-2, uPa, and IL-8. Conclusions: Our results suggest that OPN splice variants differentially exert clinicopathological features and biological functions in GC. Therefore, focusing on specific OPN isoform could be a novel direction for developing diagnostic and therapeutic approaches in GC.

Tang, Xiaojian; Li, Jianfang; Yu, Beiqin; Su, Liping; Yu, Yingyan; Yan, Min; Liu, Bingya; Zhu, Zhenggang

2013-01-01

397

Trichostatin A, a critical factor in maintaining the functional differentiation of primary cultured rat hepatocytes  

SciTech Connect

Histone deacetylase inhibitors (HDI) have been shown to increase differentiation-related gene expression in several tumor-derived cell lines by hyperacetylating core histones. Effects of HDI on primary cultured cells, however, have hardly been investigated. In the present study, the ability of trichostatin A (TSA), a prototype hydroxamate HDI, to counteract the loss of liver-specific functions in primary rat hepatocyte cultures has been investigated. Upon exposure to TSA, it was found that the cell viability of the cultured hepatocytes and their albumin secretion as a function of culture time were increased. TSA-treated hepatocytes also better maintained cytochrome P450 (CYP)-mediated phase I biotransformation capacity, whereas the activity of phase II glutathione S-transferases (GST) was not affected. Western blot and qRT-PCR analysis of CYP1A1, CYP2B1 and CYP3A11 protein and mRNA levels, respectively, further revealed that TSA acts at the transcriptional level. In addition, protein expression levels of the liver-enriched transcription factors (LETFs) hepatic nuclear factor 4 alpha (HNF4{alpha}) and CCAAT/enhancer binding protein alpha (C/EBP{alpha}) were accordingly increased by TSA throughout culture time. In conclusion, these findings indicate that TSA plays a major role in the preservation of the differentiated hepatic phenotype in culture. It is suggested that the effects of TSA on CYP gene expression are mediated via controlling the expression of LETFs.

Henkens, Tom [Department of Toxicology, Pharmaceutical Institute, Vrije Universiteit Brussel, Laarbeeklaan 103, B-1090 Brussels (Belgium)]. E-mail: Tom.Henkens@vub.ac.be; Papeleu, Peggy [Department of Toxicology, Pharmaceutical Institute, Vrije Universiteit Brussel, Laarbeeklaan 103, B-1090 Brussels (Belgium); Elaut, Greetje [Department of Toxicology, Pharmaceutical Institute, Vrije Universiteit Brussel, Laarbeeklaan 103, B-1090 Brussels (Belgium); Vinken, Mathieu [Department of Toxicology, Pharmaceutical Institute, Vrije Universiteit Brussel, Laarbeeklaan 103, B-1090 Brussels (Belgium); Rogiers, Vera [Department of Toxicology, Pharmaceutical Institute, Vrije Universiteit Brussel, Laarbeeklaan 103, B-1090 Brussels (Belgium); Vanhaecke, Tamara [Department of Toxicology, Pharmaceutical Institute, Vrije Universiteit Brussel, Laarbeeklaan 103, B-1090 Brussels (Belgium)

2007-01-01

398

Directed differentiation of human pluripotent stem cells into mature airway epithelia expressing functional CFTR protein  

PubMed Central

Cystic fibrosis (CF) is a fatal genetic disease caused by mutations in the CFTR (cystic fibrosis transmembrane conductance regulator) gene that regulates chloride and water transport across all epithelia and affects multiple organs including the lungs. Here we report an in vitro directed differentiation protocol for generating functional CFTR-expressing airway epithelia from human embryonic stem cells. Carefully timed treatment by exogenous growth factors that mimic endoderm developmental pathways in vivo followed by air-liquid interface culture results in maturation of patches of tight junction-coupled differentiated airway epithelial cells that demonstrate active CFTR transport function. As a proof-of-concept, treatment of CF patient induced pluripotent stem cells (iPSC)-derived epithelial cells with a novel small molecule compound to correct for the common CF-processing mutation resulted in enhanced plasma membrane localization of mature CFTR protein. Our study provides a method for generating patient-specific airway epithelial cells for disease modeling and in vitro drug testing.

Wong, Amy P.; Bear, Christine E.; Chin, Stephanie; Pasceri, Peter; Thompson, Tadeo O.; Huan, Ling-Jun; Ratjen, Felix; Ellis, James; Rossant, Janet

2014-01-01

399

Analyte species and concentration identification using differentially functionalized microcantilever arrays and artificial neural networks  

SciTech Connect

In the present work, we have performed analyte species and concentration identification using an array of ten differentially functionalized microcantilevers coupled with a back-propagation artificial neural network pattern recognition algorithm. The array consists of ten nanostructured silicon microcantilevers functionalized by polymeric and gas chromatography phases and macrocyclic receptors as spatially dense, differentially responding sensing layers for identification and quantitation of individual analyte(s) and their binary mixtures. The array response (i.e. cantilever bending) to analyte vapor was measured by an optical readout scheme and the responses were recorded for a selection of individual analytes as well as several binary mixtures. An artificial neural network (ANN) was designed and trained to recognize not only the individual analytes and binary mixtures, but also to determine the concentration of individual components in a mixture. To the best of our knowledge, ANNs have not been applied to microcantilever array responses previously to determine concentrations of individual analytes. The trained ANN correctly identified the eleven test analyte(s) as individual components, most with probabilities greater than 97%, whereas it did not misidentify an unknown (untrained) analyte. Demonstrated unique aspects of this work include an ability to measure binary mixtures and provide both qualitative (identification) and quantitative (concentration) information with array-ANN-based sensor methodologies.

Senesac, Larry R [ORNL; Datskos, Panos G [ORNL; Sepaniak, Michael J [ORNL

2006-01-01

400

A novel application of radial basis functions for solving a model of first-order integro-ordinary differential equation  

NASA Astrophysics Data System (ADS)

In this paper two common collocation approaches based on radial basis functions (RBFs) have been considered; one is computed through the differentiation process (DRBF) and the other one is computed through the integration process (IRBF). We investigate these two approaches on the Volterra's Population Model which is an integro-differential equation without converting it to an ordinary differential equation. To solve the problem, we use four well-known radial basis functions: Multiquadrics (MQ), Inverse multiquadrics (IMQ), Gaussian (GA) and Hyperbolic secant (sech) which is a newborn RBF. Numerical results and residual norm (?R(t)?2) show good accuracy and rate of convergence of two common approaches.

Parand, K.; Abbasbandy, S.; Kazem, S.; Rad, J. A.

2011-11-01

401

Next steps in using accessory minerals to date the evolution of silicic magmas  

NASA Astrophysics Data System (ADS)

Over the past decade, 238U-230Th-206Pb isotopic dating of accessory minerals using the high spatial resolution and sensitivity of ion microprobe analysis has provided new insights into the longevity and thermochemical evolution of silicic magmas, but has also created new questions about the generation, differentiation, and construction of silicic magma chambers. An important conclusion from in situ dating is that accessory minerals such as zircon and allanite in silicic magmas may be 10's to 100's of thousands of years older than their age of eruption. Whether these relatively "old" crystals are derived from long-lived crystal-rich magma reservoirs or inherited due to remelting of frozen intrusions remains a difficult question to answer because long-lived centers of magmatism are characteristically dynamic and are open systems. Nevertheless, not all rhyolites from loci of repeated silicic magmatism carry a dominant "cargo" of antecrystic zircon (or other accessory minerals). Crystal-poor high-silica rhyolites from Coso volcanic field, eastern California, contain a bimodal population of young zircon that yield 238U-230Th ages concordant with their respective late Pleistocene 40Ar/39Ar eruption ages, and a population of Mesozoic zircon that are obvious xenocrysts derived from wallrocks. Rhyolites erupted from La Primavera caldera, Mexico, contain zircon and chevkinite that yield 238U-230Th ages that are within 10's of k.y. of their corresponding eruption ages between ca. 125-85 ka. Antecrysts from intrusions related to older episodes of rhyolitic magmatism appear absent or exceedingly rare. The relatively short timescales between crystallization and eruption suggest that these rhyolites, unlike otherwise similar rhyolites from other systems, were tapped shortly after highly effective differentiation and/or reheating. It is apparent that zircon ages alone are insufficient for resolving the thermochemical and differentiation histories of silicic magmas, and need to be keyed to crystal-scale variations in trace element and isotopic composition, and geothermometry, as well as the compositions and ages of associated major and other accessory phases. Combination of accessory mineral dating and geospeedomety may yield unique information because these methods resolve different aspects of magma evolution over long and short timescales. Zircon crystals from a ca. 260 ka post-collapse rhyolite at Yellowstone caldera yield U-Pb ages that are 10's to 100's of k.y. older than their eruption age, whereas diffusion profiles derived from relatively high temperature rims on sanidine and pyroxenes indicate 10's of k.y. residence since heating and rim growth. These contrasting timescales reflect different aspects of magma evolution. The range of zircon ages is likely to reflect a mixture of recycled crystal residue and renewed crystallization, which is supported by petrographic evidence for inherited plutonic cores in pyroxenes. This combined dating may provide a way to test whether any "old" crystals reflect freeze-thaw thermal cycles in the subvolcanic environment or protracted storage of magma in mushy or melt rich reservoirs.

Vazquez, J. A.

2011-12-01

402

49 CFR 192.147 - Flanges and flange accessories.  

Code of Federal Regulations, 2013 CFR

...flange accessory (other than cast iron) must meet the minimum...able to withstand the maximum pressure at which the pipeline is...flange on a flanged joint in cast iron pipe must conform in dimensions...to ASME/ANSI B16.1 and be cast integrally with the pipe,...

2013-10-01

403

Evolutionary dynamics of the accessory genome of Listeria monocytogenes.  

PubMed

Listeria monocytogenes, a foodborne bacterial pathogen, is comprised of four phylogenetic lineages that vary with regard to their serotypes and distribution among sources. In order to characterize lineage-specific genomic diversity within L. monocytogenes, we sequenced the genomes of eight strains from several lineages and serotypes, and characterized the accessory genome, which was hypothesized to contribute to phenotypic differences across lineages. The eight L. monocytogenes genomes sequenced range in size from 2.85-3.14 Mb, encode 2,822-3,187 genes, and include the first publicly available sequenced representatives of serotypes 1/2c, 3a and 4c. Mapping of the distribution of accessory genes revealed two distinct regions of the L. monocytogenes chromosome: an accessory-rich region in the first 65° adjacent to the origin of replication and a more stable region in the remaining 295°. This pattern of genome organization is distinct from that of related bacteria Staphylococcus aureus and Bacillus cereus. The accessory genome of all lineages is enriched for cell surface-related genes and phosphotransferase systems, and transcriptional regulators, highlighting the selective pressures faced by contemporary strains from their hosts, other microbes, and their environment. Phylogenetic analysis of O-antigen genes and gene clusters predicts that serotype 4 was ancestral in L. monocytogenes and serotype 1/2 associated gene clusters were putatively introduced through horizontal gene transfer in the ancestral population of L. monocytogenes lineage I and II. PMID:23825666

den Bakker, Henk C; Desjardins, Christopher A; Griggs, Allison D; Peters, Joseph E; Zeng, Qiandong; Young, Sarah K; Kodira, Chinnappa D; Yandava, Chandri; Hepburn, Theresa A; Haas, Brian J; Birren, Bruce W; Wiedmann, Martin

2013-01-01

404

Hearing Aid Accessories for Adults: The Remote FM Microphone  

Microsoft Academic Search

Objective: The primary goal was to determine the benefits and limitations of a remote FM microphone as a hearing aid accessory. A secondary goal was to determine the predictors of aided and FM-assisted speech perception by adults with hearing loss, in quiet and in noise, using methods derived from Articulation Index theory. Design: Twelve adults with mild to severe hearing

Arthur Boothroyd

2004-01-01

405

Schwannoma of the Spinal Accessory Nerve: A Case Report  

PubMed Central

We are reporting a rare case of a schwannoma which originated from the cervical portion of the spinal accessory nerve, which was located in the left posterior triangle of the neck and did not have any neurological deficit, which was diagnosed by the Magnetic Resonance Imaging (MRI) scan and confirmed histopathologically after surgery.

Kohli, Ritesh; Singh, Surinder; Gupta, Sahwani K.; Matreja, Prithpal S.

2013-01-01

406

Clothing/Apparel and Accessories Merchandising. A Suggested Interdisciplinary Guide.  

ERIC Educational Resources Information Center

This curriculum guide contains three sections: introduction, curriculum material, and an annotated bibliography. Introductory information provides an overview of the clothing/apparel and accessories merchandising area, aptitudes needed, and career opportunities; discusses potential career ladders, which are divided into entry level, middle…

Wray, Ralph D.; Hayden, Margaret B.

407

Uranium Series Accessory Crystal Dating of Magmatic Processes  

NASA Astrophysics Data System (ADS)

Complex and protracted crystallization histories over geologic timescales are recorded in accessory minerals (e.g., zircon, allanite). Although magmatic crystallization was traditionally assumed to occur essentially instantaneously for the purposes of interpreting mineral geochronometers with low absolute time resolution for ancient samples, it emerged relatively recently that magmatic crystallization can occur over extended durations. This discovery arose from applying high-spatial-resolution accessory mineral dating techniques for uranium series isotopes to young volcanic and cognate plutonic rocks. The emerging pattern from these studies is that individual crystals and crystal populations record crystallization episodes lasting from <1,000 to many hundreds of thousands of years. Accessory mineral dating of volcanic rocks and cognate plutonic xenoliths opens new research avenues for crystal age fingerprinting that correlates pyroclastic deposits, lavas, and plutonic rocks by using characteristic age distributions. It also provides direct observations on magmatic accumulation and residence times, and the preeruptive configuration of subterraneous magma bodies and intrusive complexes with implications for the forecasting of volcanic eruptions. Awareness of potentially protracted crystallization in igneous rocks should guide the interpretation of accessory mineral ages.

Schmitt, Axel K.

2011-05-01

408

The Effects of Accessory Stimuli on Information Processing: Evidence from Electrophysiology and a Diffusion Model Analysis  

Microsoft Academic Search

People typically respond faster to a stimulus when it is accompanied by a task-irrelevant accessory stimulus presented in another perceptual modality. However, the mechanisms responsible for this accessory-stimulus effect are still poorly understood. We examined the effects of auditory accessory stimulation on the processing of visual stimuli using scalp electrophysiology (Experiment 1) and a diffusion model analysis (Experiment 2). In

Marieke Jepma; Eric-Jan Wagenmakers; Guido P. H. Band; Sander Nieuwenhuis

2008-01-01

409

Functional Redundancy of Type II BMP Receptor and Type IIB Activin Receptor in BMP2-Induced Osteoblast Differentiation  

PubMed Central

Signaling pathways for bone morphogenetic proteins (BMPs) are important in osteoblast differentiation. Although the precise function of type I BMP receptors in mediating BMP signaling for osteoblast differentiation and bone formation has been characterized previously, the role of type II BMP receptors in osteoblasts is to be well clarified. In this study, we investigated the role of type II BMP receptor (BMPR-II) and type IIB activin receptor (ActR-IIB) in BMP2-induced osteoblast differentiation. While osteoblastic 2T3 cells expressed BMPR-II and ActR-IIB, loss-of-function studies, using dominant negative receptors and siRNAs, showed that BMPR-II and ActR-IIB compensated each other functionally in mediating BMP2 signaling and BMP2-induced osteoblast differentiation. This was evidenced by two findings. First, unless there was loss of function of both type II receptors, isolated disruption of either BMPR-II or ActR-IIB did not remove BMP2 activity. Second, in cells with loss of function of both receptors, restoration of function of either BMPR-II or ActR-IIB by transfection of the wild-type forms, restored BMP2 activity. These findings suggest a functional redundancy between BMPR-II and ActR-IIB in osteoblast differentiation. Results from experiments to test the effects of transforming growth factor b (TGF-?), activin, and fibroblast growth factor (FGF) on osteoblast proliferation and differentiation suggest that inhibition of receptor signaling by double-blockage of BMPR-II and ActR-IIB is BMP-signaling specific. The observed functional redundancy of type II BMP receptors in osteoblasts is novel information about the BMP signaling pathway essential for initiating osteoblast differentiation.

LIU, HONGBIN; ZHANG, RONGRONG; CHEN, DI; OYAJOBI, BABATUNDE O.; ZHAO, MING

2013-01-01

410

Application of functional analysis to perturbation theory of differential equations. [nonlinear perturbation of the harmonic oscillator  

NASA Technical Reports Server (NTRS)

The deviation of the solution of the differential equation y' = f(t, y), y(O) = y sub O from the solution of the perturbed system z' = f(t, z) + g(t, z), z(O) = z sub O was investigated for the case where f and g are continuous functions on I x R sup n into R sup n, where I = (o, a) or I = (o, infinity). These functions are assumed to satisfy the Lipschitz condition in the variable z. The space Lip(I) of all such functions with suitable norms forms a Banach space. By introducing a suitable norm in the space of continuous functions C(I), introducing the problem can be reduced to an equivalent problem in terminology of operators in such spaces. A theorem on existence and uniqueness of the solution is presented by means of Banach space technique. Norm estimates on the rate of growth of such solutions are found. As a consequence, estimates of deviation of a solution due to perturbation are obtained. Continuity of the solution on the initial data and on the perturbation is established. A nonlinear perturbation of the harmonic oscillator is considered a perturbation of equations of the restricted three body problem linearized at libration point.

Bogdan, V. M.; Bond, V. B.

1980-01-01

411

Memory Functioning and Negative Symptoms as Differential Predictors of Social Problem Solving Skills in Schizophrenia  

PubMed Central

Background Neurocognition in general, and memory functioning in particular, as well as symptoms have all been shown to be related to social problem solving (SPS) in schizophrenia. However, few studies have directly compared the relative contribution of neurocognition vs. psychiatric symptoms to the components of SPS. Method Sixty outpatients (aged 21 – 65) who met DSM-IV criteria for schizophrenia or schizoaffective disorder were administered a broad battery of memory tests and assessed for severity of positive and negative symptoms as part of a baseline assessment of a study of psychiatric rehabilitation. Multiple regression analyses were used to examine the contribution of memory functioning vs. symptoms on receiving, processing, and sending skill areas of social problem solving ability. Results An index of verbal learning was the strongest predictor of processing skills whereas negative symptoms were the strongest predictor of sending skills. Positive symptoms were not related to any of the three skill areas of social problem solving. Conclusions Memory functioning and psychiatric symptoms differentially predict selected areas of social problem solving ability in persons with schizophrenia. Consistent with other reports, positive symptoms were not related to social problem solving. Consideration of both neurocognition and negative symptoms may be important to the development of rehabilitation interventions in this area of functioning.

Ventura, Joseph; Tom, Shelley R.; Jetton, Chris; Kern, Robert S.

2014-01-01

412

Differential regulation of thyroid hormone receptor-mediated function by endocrine disruptors.  

PubMed

It is well known that endocrine disruptors (EDs) act as anti-estrogenic agents and affect the function of reproductive organ. EDs are also thought to affect thyroid hormone (TH) system which is important for biological functions such as growth, development and metabolism. However, it is still not clear how EDs are able to regulate TH receptor (TR)-mediated functions. In this study, therefore, the modulatory effects of representative EDs such as 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), polychlorinated biphenyl (Aroclor 1254) and bisphenol A (BPA) were examined using TR-expressing GH3 cells (a rat pituitary gland epithelial tumor cell line) activated by triiodothyronine (T3). EDs tested significantly blocked T3 binding to TR in a dose-dependent manner. Biochemical characterization by Scatchard and Lineweaver-Burk plot analyses indicated that TCDD and aroclor 1254 bound to TH receptors in a competitive inhibitory manner, whereas BPA bound to TH receptors in a non-competitive pattern. The different inhibitory mode of action by EDs was also found in regulating TR-mediated production of prolactin (PRL). Aroclor 1254 exposure for 48 h enhanced T3-mediated PRL production, but BPA down-regulated. These results suggest that the EDs (TCDD, Aroclor 1254 and BPA) could differentially bind to TR and distinctly regulate the action of TR function, even though EDs are structurally similar. PMID:17615682

Jung, Ki Kyung; Kim, So Young; Kim, Tae Gyun; Kang, Ju Hye; Kang, Seog Youn; Cho, Jae Youl; Kim, Seung Hee

2007-05-01

413

Controlled Speed Accessory Drive Program: Programmatic environmental assessment  

SciTech Connect

This document is a programmatic environmental assessment of the Department of Energy's Controlled Speed Accessory Drive (CSAD) program and alternatives. Its purpose is to evaluate CSAD alternatives to assure that environmental priorities are considered at the earliest meaningful point in the decision-making process, and to facilitate the choice of preferable options. This document accords with both the letter and the spirit of the National Environmental Policy Act (NEPA) requirements as interpreted and standardized by the Council on Environmental Quality. The major conclusions reached in this assessment are as follows: (1) controlled speed accessory drive bolted onto existing automobile designs may not provide adequate engine cooling when operated at high ambient temperatures or under heavy loading; (2) when the CSAD is adopted for production, the emissions effect of controlled speed accessory drive will not be a problem. Auto emissions are already controlled by existing regulations, and automobiles with a CSAD must meet the same emission standards as non-CSAD vehicles; (3) the nature of the impact is such that significant expansion of the market will not affect it. The one adverse environmental concern, the engine cooling problem, will probably be remedied by proper optimization of automobiles for controlled speed accessory drive, or, until the problem can be alleviated, it will delay commercialization of the drive. No safety hazard will be introduced to the American roadways. In addition, no adverse environmental concerns directly related to the Controlled Speed Accessory Drive demonstration program are anticipated. Therefore, it is recommended that a finding of no significant impact be prepared.

Not Available

1980-04-14

414

Collagen functionalized bioactive nanofiber matrices for osteogenic differentiation of mesenchymal stem cells: bone tissue engineering.  

PubMed

Scaffold architecture, surface topography, biochemical and mechanical cues have been shown to significantly improve cellular events and in vivo tissue regeneration. Specifically electrospun nanofiber matrices have gained tremendous interest due to their intrinsic structural resemblance to native tissue extracellular matrix (ECM). The present study reports on the electrospun nanofiber matrices of polycaprolactone (PCL)-chitosan (CS) blends and effect of type I collagen surface functionalization in regulating rat bone marrow derived stromal cells (rBMSCs) differentiation into osteogenic lineage. Collagen was covalently attached to blend nanofibers via carbodiimide (EDC) coupling. Bead-free smooth nanofibers (diameter-700-850 nm) obtained at the optimized conditions of polymer concentration and electrospinning parameters were used for the study. EDC collagen coupling resulted in 0.120+/-0.016 micro g of collagen immobilization onto a 1 cm2 area of the PCL/CS nanofibers, which was 2.6-folds higher than the amount of collagen that can be retained by physical adsorption. Significantly improved rBMSCs adhesion, spreading, proliferation and osteogenic differentiation was observed on the collagen functionalized COL-PCULCS nanofiber matrices as compared to control groups. Osteogenic phenotypic markers such as alkaline phosphatase (ALP) activity and mineralization were found to be significantly higher on COL-PCL/CS nanofiber matrices as compared to controls. Elevated gene expression profiles of osteogenic markers such as osteocalcin (0CN), osteopontin (OPN) and ALP further corroborate the osteoinductive nature of the collagen functionalized PCL/CS nanofiber matrices. These fiber matrices and modification techniques could be extended to other scaffold systems for tissue engineering applications. PMID:24738337

Cheng, Yixing; Ramos, Daisy; Lee, Paul; Liang, Danni; Yu, Xiaojun; Kumbar, Sangamesh G

2014-02-01

415

Meningioma 1 Is Required for Appropriate Osteoblast Proliferation, Motility, Differentiation, and Function*  

PubMed Central

The vitamin D endocrine system is essential for calcium and phosphate homeostasis and skeletal mineralization. The 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) hormone binds to the vitamin D receptor (VDR) to regulate gene expression. These gene products in turn mediate the actions of 1,25(OH)2D3 in mineral-regulating target cells such as the osteoblast. We showed previously that meningioma 1 (MN1) is a novel target of 1,25(OH)2D3 in MG-63 osteoblastic cells and that it is a coactivator for VDR-mediated transcription (Sutton, A. L., Zhang, X., Ellison, T. I., and MacDonald, P. N. (2005) Mol. Endocrinol. 19, 2234–2244). However, the functional significance of MN1 in osteoblastic cell biology is largely unknown. Here, we demonstrate that MN1 expression is increased dramatically during differentiation of primary osteoblastic cells. Using calvarial osteoblasts derived from wild-type and MN1 knock-out mice, we provide data supporting an essential role of MN1 in maintaining appropriate osteoblast proliferation, differentiation, and function. MN1 knock-out osteoblasts displayed altered morphology, decreased growth rate, impaired motility, and attenuated 1,25(OH)2D3/VDR-mediated transcription as well as reduced alkaline phosphatase activity and mineralized nodule formation. MN1 null osteoblasts were also impaired in supporting osteoclastogenesis in co-culture studies presumably because of marked reduction in the RANKL:OPG ratio in the MN1 null cells. Mechanistic studies supported a transcriptional role for MN1 in controlling RANKL gene expression through activation of the RANKL promoter. Cumulatively, these studies indicate an important role for MN1 in maintaining the appropriate maturation and function of calvarial osteoblasts.

Zhang, Xiaoxue; Dowd, Diane R.; Moore, Meika C.; Kranenburg, Tanya A.; Meester-Smoor, Magda A.; Zwarthoff, Ellen C.; MacDonald, Paul N.

2009-01-01

416

Yeast Irc6p is a novel type of conserved clathrin coat accessory factor related to small G proteins  

PubMed Central

Clathrin coat accessory proteins play key roles in transport mediated by clathrin-coated vesicles. Yeast Irc6p and the related mammalian p34 are putative clathrin accessory proteins that interact with clathrin adaptor complexes. We present evidence that Irc6p functions in clathrin-mediated traffic between the trans-Golgi network and endosomes, linking clathrin adaptor complex AP-1 and the Rab GTPase Ypt31p. The crystal structure of the Irc6p N-terminal domain revealed a G-protein fold most related to small G proteins of the Rab and Arf families. However, Irc6p lacks G-protein signature motifs and high-affinity GTP binding. Also, mutant Irc6p lacking candidate GTP-binding residues retained function. Mammalian p34 rescued growth defects in irc6? cells, indicating functional conservation, and modeling predicted a similar N-terminal fold in p34. Irc6p and p34 also contain functionally conserved C-terminal regions. Irc6p/p34-related proteins with the same two-part architecture are encoded in genomes of species as diverse as plants and humans. Together these results define Irc6p/p34 as a novel type of conserved clathrin accessory protein and founding members of a new G protein–like family.

Gorynia, Sabine; Lorenz, Todd C.; Costaguta, Giancarlo; Daboussi, Lydia; Cascio, Duilio; Payne, Gregory S.

2012-01-01

417

Highly Efficient Differentiation of Functional Hepatocytes From Human Induced Pluripotent Stem Cells  

PubMed Central

Human induced pluripotent stem cells (hiPSCs) hold great potential for use in regenerative medicine, novel drug development, and disease progression/developmental studies. Here, we report highly efficient differentiation of hiPSCs toward a relatively homogeneous population of functional hepatocytes. hiPSC-derived hepatocytes (hiHs) not only showed a high expression of hepatocyte-specific proteins and liver-specific functions, but they also developed a functional biotransformation system including phase I and II metabolizing enzymes and phase III transporters. Nuclear receptors, which are critical for regulating the expression of metabolizing enzymes, were also expressed in hiHs. hiHs also responded to different compounds/inducers of cytochrome P450 as mature hepatocytes do. To follow up on this observation, we analyzed the drug metabolizing capacity of hiHs in real time using a novel ultraperformance liquid chromatography-tandem mass spectrometry. We found that, like freshly isolated primary human hepatocytes, the seven major metabolic pathways of the drug bufuralol were found in hiHs. In addition, transplanted hiHs engrafted, integrated, and proliferated in livers of an immune-deficient mouse model, and secreted human albumin, indicating that hiHs also function in vivo. In conclusion, we have generated a method for the efficient generation of hepatocytes from induced pluripotent stem cells in vitro and in vivo, and it appears that the cells function similarly to primary human hepatocytes, including developing a complete metabolic function. These results represent a significant step toward using patient/disease-specific hepatocytes for cell-based therapeutics as well as for pharmacology and toxicology studies.

Ma, Xiaocui; Tschudy-Seney, Benjamin; Roll, Garrett; Behbahan, Iman Saramipoor; Ahuja, Tijess P.; Tolstikov, Vladimir; Wang, Charles; McGee, Jeannine; Khoobyari, Shiva; Nolta, Jan A.; Willenbring, Holger

2013-01-01

418

Differentiations and Functional State of Osteogenic Cells in Conditions of Microgravity  

NASA Astrophysics Data System (ADS)

The space flight factors (space radiation, magnetic fields etc.) affect considerably the state of bone tissue, leading to the development of osteoporosis and osteopenia in the bone skeleton. Many aspects of reactions of bone tissue cells still remain unclear until now. With the use of electron microscopy and autoradiography with 3H-thymidine we studied the samples gathered from the femoral bone epiphyses and metaphyses of rats flown on board American Spacelab -2 and in experiments with modeling of microgravity ("tail suspension" method). In our work the main attention is focused on studying the ultrastructure and metabolism of osteogenetic cells. The degree of differentiation and functional state are evaluated according to the degree of development of organelles for specific biosynthesis: rough endoplasmic reticulum (RER), Golgy complex (GC), as well as the state of mitochondria and cell nucleus. As compared with a control, the population of osteogenetic cells from zones of bone reconstruction shows a decrease in the number of functionally active forms. We can judge of this from the reduction volume of RER, GC, mitochondria in osteoblasts. RER loses architectonics typical for osteoblasts and, as against the control, is represented by short narrow canaliculi distributed throughout the cy-toplasm; some canals disintegrate. GC is slightly pronounced, mitochondria become smaller in size and acquire an optically dark matrix. These phenomena are supposed to be associated with the desorganization of microtubules and microfilaments in the cells under microgravity condi-tions. The number of degrading and apoptotic cells increases in the population of osteoblasts. The dynamics of labeled cells following various intervals after 3H-thymidine injection testifies to a delay in the rates of osteoblasts' differentiation and their transformation to osteocytes in the experiment animals. A lower 3H-glycine uptake by the osteogenic cells and bone matrix as compared with a control is indicative of a decrease of the osteoplastic process under hypokinesia and modeling microgravity. We concluded that microgravity results in low differentiations and reduction specific functions of osteogenic cells.

Onishchenko, Ganna; Rodionova, Natalia; Markevich, Ganna; Markevich, Ganna

419

Differential uptake of functionalized polystyrene nanoparticles by human macrophages and a monocytic cell line.  

PubMed

Tumor cell lines are often used as models for the study of nanoparticle-cell interactions. Here we demonstrate that carboxy (PS-COOH) and amino functionalized (PS-NH2) polystyrene nanoparticles of ?100 nm in diameter are internalized by human macrophages, by undifferentiated and by PMA-differentiated monocytic THP-1 cells via diverse mechanisms. The uptake mechanisms also differed for all cell types and particles when analyzed either in buffer or in medium containing human serum. Macrophages internalized ?4 times more PS-COOH than THP-1 cells, when analyzed in serum-containing medium. By contrast, in either medium, THP-1 cells internalized PS-NH2 more rapidly than macrophages. Using pharmacological and antisense in vitro knockdown approaches, we showed that, in the presence of serum, the specific interaction between the CD64 receptor and the particles determines the macrophage uptake of particles by phagocytosis, whereas particle internalization in THP-1 cells occurred via dynamin II-dependent endocytosis. PMA-differentiated THP-1 cells differed in their uptake mechanism from macrophages and undifferentiated THP-1 cells by internalizing the particles via macropinocytosis. In line with our in vitro data, more intravenously applied PS-COOH particles accumulated in the liver, where macrophages of the reticuloendothelial system reside. By contrast, PS-NH2 particles were preferentially targeted to tumor xenografts grown on the chorioallantoic membrane of fertilized chicken eggs. Our data show that the amount of internalized nanoparticles, the uptake kinetics, and its mechanism may differ considerably between primary cells and a related tumor cell line, whether differentiated or not, and that particle uptake by these cells is critically dependent on particle opsonization by serum proteins. PMID:21344890

Lunov, Oleg; Syrovets, Tatiana; Loos, Cornelia; Beil, Johanna; Delacher, Michael; Tron, Kyrylo; Nienhaus, G Ulrich; Musyanovych, Anna; Mailänder, Volker; Landfester, Katharina; Simmet, Thomas

2011-03-22

420

Effectiveness of Combining Statistical Tests and Effect Sizes When Using Logistic Discriminant Function Regression to Detect Differential Item Functioning for Polytomous Items  

ERIC Educational Resources Information Center

The objective of this article was to find an optimal decision rule for identifying polytomous items with large or moderate amounts of differential functioning. The effectiveness of combining statistical tests with effect size measures was assessed using logistic discriminant function analysis and two effect size measures: R[superscript 2] and…

Gómez-Benito, Juana; Hidalgo, Maria Dolores; Zumbo, Bruno D.

2013-01-01

421

Restoring ciliary function to differentiated primary ciliary dyskinesia cells with a lentiviral vector.  

PubMed

Primary ciliary dyskinesia (PCD) is a genetically heterogenous autosomal recessive disease in which mutations disrupt ciliary function, leading to impaired mucociliary clearance and life-long lung disease. Mouse tracheal cells with a targeted deletion in the axonemal dynein intermediate chain 1 (Dnaic1) gene differentiate normally in culture but lack ciliary activity. Gene transfer to undifferentiated cultures of mouse Dnaic1(-/-) cells with a lentiviral vector pseudotyped with avian influenza hemagglutinin restored Dnaic1 expression and ciliary activity. Importantly, apical treatment of well-differentiated cultures of mouse Dnaic1(-/-) cells with lentiviral vector also restored ciliary activity, demonstrating successful gene transfer from the apical surface. Treatment of Dnaic1(flox/flox) mice expressing an estrogen-responsive Cre recombinase with different doses of tamoxifen indicated that restoration of ?20% of ciliary activity may be sufficient to prevent the development of rhinosinusitis. However, although administration of a ?-galactosidase-expressing vector into control mice demonstrated efficient gene transfer to the nasal epithelium, treatment of Dnaic1(-/-) mice resulted in a low level of gene transfer, demonstrating that the severe rhinitis present in these animals impedes gene transfer. The results demonstrate that gene replacement therapy may be a viable treatment option for PCD, but further improvements in the efficiency of gene transfer are necessary. PMID:24451115

Ostrowski, L E; Yin, W; Patel, M; Sechelski, J; Rogers, T; Burns, K; Grubb, B R; Olsen, J C

2014-03-01

422

Differential and synergistic effects of mechanical stimulation and growth factor presentation on vascular wall function.  

PubMed

We investigated the hypothesis that immobilizing TGF-?1 within fibrin hydrogels may act in synergy with cyclic mechanical stimulation to enhance the properties of vascular grafts. To this end, we engineered a fusion TGF-?1 protein that can covalently anchor to fibrin during polymerization upon the action of factor XIII. We also developed a 24-well based bioreactor in which vascular constructs can be mechanically stimulated by distending the silastic mandrel in the middle of each well. TGF-?1 was either conjugated to fibrin or supplied in the culture medium and the fibrin-based constructs were cultured statically for a week followed by cyclic distention for another week. The tissues were examined for myogenic differentiation, vascular reactivity, mechanical properties and ECM content. Our results showed that some aspects of vascular function were differentially affected by growth factor presentation vs. pulsatile force application, while others were synergistically enhanced by both. Overall, this two-prong biomimetic approach improved ECM secretion, vascular reactivity and mechanical properties of vascular constructs. These findings may be applied in other tissue engineering applications such as cartilage, tendon or cardiac regeneration where growth factors TGF-?1 and mechano-stimulation play critical roles. PMID:23810080

Liang, Mao-Shih; Koobatian, Maxwell; Lei, Pedro; Swartz, Daniel D; Andreadis, Stelios T

2013-10-01

423

Differential Item Functioning for Lesbians, Bisexual, and Heterosexual Women in the Center for Epidemiological Studies Depression Scale  

ERIC Educational Resources Information Center

This study assessed whether the Center for Epidemiological Studies Depression Scale (CES-D) functions equivalently in assessing depressive symptom severity in lesbian, bisexual, and heterosexual women. Using differential item functioning methods, the authors examined (a) whether there is a bias in CES-D total scores and in individual item scores…

Birnholz, Justin L.; Young, Michael A.

2012-01-01

424

THE WEIGHTED SPACES L_{p,r}^\\alpha(\\rho_1,\\,\\rho_2) OF DIFFERENTIABLE FUNCTIONS OF FRACTIONAL SMOOTHNESS  

NASA Astrophysics Data System (ADS)

This is an investigation of weighted spaces of differentiable functions of fractional smoothness consisting of functions f(x) which are r-integrable with a weight \\rho_1 and have "fractional derivatives" which are p-integrable with a weight \\rho_2.Bibliography: 20 titles.

Nogin, V. A.

1988-02-01

425

An Empirical Comparison of Mantel-Haenszel and Rasch Procedures for Studying Differential Item Functioning on Teacher Certification Tests.  

ERIC Educational Resources Information Center

The agreement between Mantel-Haenszel and Rasch procedures for identifying differential item functioning (DIF) on teacher certification tests was studied. Two specific research questions were addressed: (1) whether the Mantel-Haenszel and Rasch procedures identify the same items as functioning differently; and (2) how consistently each method…

Engelhard, George, Jr.; And Others

426

Speech disturbances and quality of life in schizophrenia: Differential impacts on functioning and life satisfaction.  

PubMed

Speech disturbances in schizophrenia impact on the individual's communicative ability. Although they are considered a core feature of schizophrenia, comparatively little work has been done to examine their impact on the life experiences of patients. This study aimed to examine the relationship between schizophrenia speech disturbances, including those traditionally known as formal thought disorder (TD), and quality of life (QoL). It assessed effects on functioning (objective QoL) and satisfaction (subjective QoL) concurrently, while controlling for the influence of neurocognition and depression. Fifty-four patients with schizophrenia/schizoaffective disorder were administered the MATRICS Consensus Cognitive Battery (MCCB), the PANSS, MADRS (with separate ratings for negative TD [verbal underproductivity] and positive TD [verbal disorganisation and pressured speech]) and Lehman's QOLI assessing both objective and subjective QoL. Ratings of positive and negative TD, depression, and general neurocognition were entered into hierarchical regressions to explore their relationship with both life functioning and satisfaction. Verbal underproductivity was a significant predictor of objective QoL, while pressured speech had a trend association with subjective QoL. This suggests a differential relationship between speech disturbances and QoL. Verbal underproductivity seems to affect daily functioning and relations with others, while pressured speech is predictive of satisfaction with life. The impact of verbal underproductivity on QoL suggests it to be an important target for rehabilitation in schizophrenia. PMID:24315617

Tan, Eric J; Thomas, Neil; Rossell, Susan L

2014-04-01

427

Proteome analysis of functionally differentiated bovine (Bos indicus) mammary epithelial cells isolated from milk.  

PubMed

Mammary gland is made up of a branching network of ducts that end in alveoli. Terminally differentiated mammary epithelial cells (MECs) constitute the innermost layer of aveoli. They are milk-secreting cuboidal cells that secrete milk proteins during lactation. Little is known about the expression profile of proteins in the metabolically active MECs during lactation or their functional role in the lactation process. In the present investigation, we have reported the proteome map of MECs in lactating cows using 2DE MALDI-TOF/TOF MS and 1D-Gel-LC-MS/MS. MECs were isolated from milk using immunomagnetic beads and confirmed by RT-PCR and Western blotting. The 1D-Gel-LC-MS/MS and 2DE-MS/MS based approaches led to identification of 431 and 134 proteins, respectively, with a total of 497 unique proteins. Proteins identified in this study were clustered into functional groups using bioinformatics tools. Pathway analysis of the identified proteins revealed 28 pathways (p < 0.05) providing evidence for involvement of various proteins in lactation function. This study further provides experimental evidence for the presence of many proteins that have been predicted in annotated bovine genome. The data generated further provide a set of bovine MEC-specific proteins that will help the researchers to understand the molecular events taking place during lactation. PMID:24030930

Janjanam, Jagadeesh; Jamwal, Manu; Singh, Surender; Kumar, Saravanan; Panigrahi, Aswini K; Hariprasad, Gururao; Jena, Manoj K; Anand, Vijay; Kumar, Sudarshan; Kaushik, Jai K; Dang, Ajay K; Mukesh, Manishi; Mishra, Bishnu P; Srinivasan, Alagiri; Reddy, Vanga S; Mohanty, Ashok K

2013-11-01

428

Stimulation of proliferation, differentiation, and function of human cells by primate interleukin 3  

SciTech Connect

Cloned gibbon interleukin 3 (gIL-3) was found to stimulate the proliferation and differentiation of human bone marrow cells to produce day-14 granulocyte, macrophage, granulocyte-macrophage, and eosinophil colonies in semisolid agar. In the presence of normal human plasma, gIL-3 stimulated megakaryocytes. In methylcellulose cultures, it stimulated erythroid colonies in the presence, but not in the absence, of erythropoietin. When mature human leukocytes were used, gIL-3 stimulated the function of purified mature eosinophils as measured by the capacity to kill /sup 51/Cr-labeled antibody-coated target cells, to produce superoxide anions, and to phagocytize opsonized yeast particles in a manner similar to recombinant human granulocyte-macrophage colony-stimulating factor. In contrast, gIL-3 did not significantly stimulate any of the neutrophil functions tested, whereas human recombinant granulocyte-macrophage colony-stimulating factor was active in these assay. Among cytokines that are active on human hematopoietic cells, gIL-3 thus has a distinct set of functions and may predict the range of actions of the human molecule.

Lopez, A.F.; To, L.B.; Yang, Y.C.; Gamble, J.R.; Shannon, M.F.; Burns, G.F.; Dyson, P.G.; Juttner, C.A.; Clark, S.; Vadas, M.A.

1987-05-01

429

Functional genomic screen of human stem cell differentiation reveals pathways involved in neurodevelopment and neurodegeneration  

PubMed Central

Human embryonic stem cells (hESCs) can be induced and differentiated to form a relatively homogeneous population of neuronal precursors in vitro. We have used this system to screen for genes necessary for neural lineage development by using a pooled human short hairpin RNA (shRNA) library screen and massively parallel se