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Anchor

Distribution by Scientific Domains
Chemistry25%
Life Sciences23%
Medical Sciences14%
Engineering10%
Business, Economics, Finance and Accounting8%
Humanities and Social Sciences7%
Education3%
4 Other Domains10%
Distribution within Chemistry
Biochemistry28%
General & Introductory Chemistry12%
Crystallography8%
9 Other Subdomains40%

Kinds of Anchor

  • gpi anchor
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  • lipid anchor
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  • membrane anchor
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    Terms modified by Anchor

  • anchor point
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  • anchor signal sequence
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    Selected Abstracts

    STUDY OF ROMAN ANCHOR FROM THE DEAD SEA SHORE*

    ARCHAEOMETRY, Issue 6 2009
    G. HADAS
    A wooden Roman anchor was discovered at the retreating shore of the Dead Sea, north of Ein Gedi. The anchor's wood material was coated by a thick veneer of aragonite and gypsum crusts. The wood was dated by radiocarbon to the early Roman time in the Levant. Lead isotope analyses carried out on the Pb,Fe,Cu anchor material (remains of the anchor's metal parts) yielded ratios that indicate origin of the metal in Italian ores (maybe Tuscan). For the wooden part of the anchor a local tree was used. [source]

    Comparison of the maritime Sites and Monuments Record with side-scan sonar and diver surveys: A case study from Rathlin Island, Ireland

    GEOARCHAEOLOGY: AN INTERNATIONAL JOURNAL, Issue 5 2002
    Rory Quinn
    Rathlin Island, off the north coast of Ireland, has a history of settlement and seafaring from the Late Mesolithic period to the present day. The maritime Sites and Monuments Record (SMR) for Rathlin indicates many wrecking incidents. In 1999, a reconnaissance side-scan sonar survey confirmed the presence of 46 targets of possible archaeological potential around Rathlin Island. Thirteen of these anomalies were positively identified as shipwrecks. Of the remaining 33 targets, nine were dived on in order to ground-truth the geophysical data. A successful and rapid methodology of ground-truthing side-scan sonar data for archaeological purposes was developed. The results confirmed the presence of a Danforth Anchor at one site, while the remaining anomalies were identified as geological features. The results from the side-scan survey and diver-truthing exercise enhanced the existing maritime SMR. © 2002 Wiley Periodicals, Inc. [source]

    Methods to Determine the Minimum Important Difference for a Sexual Event Diary Used by Postmenopausal Women with Hypoactive Sexual Desire Disorder

    THE JOURNAL OF SEXUAL MEDICINE, Issue 5 2007
    Tara Symonds PhD
    ABSTRACT Introduction., Recently, there has been much discussion in the literature about how to determine the meaningfulness of results generated from a patient-reported outcome measure. A number of reviews have shown that there are two main approaches: anchor- and distribution-based approaches for determining the minimum important difference (MID) for a new measure. There are issues with calculating an MID using each method: Will the two approaches give the same estimate? If the estimates differ, how do you decide on one estimate? Would asking patients directly be more beneficial? Aim., A case study was presented to address these issues based on a newly developed diary assessing number of satisfactory sexual events (SSEs) per week in women with hypoactive sexual desire disorder (HSDD). Methods., Anchor- and distribution-based estimates were generated from data gathered in two double-blind, placebo-controlled, parallel group trials for the treatment of HSDD (N = 788). A novel interview study was used to ask women directly about an MID for SSEs (N = 77). Main Outcome Measures., Defining the MID for an SSE diary in women with HSDD. Results., The estimates varied, producing a range of mean MID estimates between 0.04 and 0.46 SSEs per week. Conclusion., We recommend that rather than defining the MID, a range should be selected from the set of estimates formed by the limits of the 95% confidence intervals. Symonds T, Spino C, Sisson M, Soni P, Martin M, Gunter L, and Patrick DL. Methods to determine the minimum important difference for a sexual event diary used by postmenopausal women with hypoactive sexual desire disorder. J Sex Med 2007;4;1328,1335. [source]

    "Black Folks Here and There": Diasporic Specificity and Relationality in Jacqueline Nassy Brown's Dropping Anchor, Setting Sail

    ANTIPODE, Issue 2 2007
    Tina M Campt
    First page of article [source]

    Rapid Protein Anchoring into the Membranes of Mammalian Cells Using Oleyl Chain and Poly(ethylene glycol) Derivatives

    BIOTECHNOLOGY PROGRESS, Issue 3 2004
    Koichi Kato
    The cell membrane is an important interface for communication with extracellular events, and incorporation of bioactive substances, such as antibodies and receptors, into the cell membrane may enhance the potential abilities of cells. Gene manipulation, chemical modification of membrane proteins, and cell surface painting using a GPI anchor have been performed to introduce substances into cell membranes. Furthermore, many lipid anchors have also been used to modify lipid membranes such as liposomes. In this study, we have focused on developing an easy and rapid method for anchoring of substances including macromolecular proteins into the membranes of living mammalian cells. We employed a single oleyl chain derivative coupled with hydrophilic poly(ethylene glycol) (PEG90, the ethyleneoxide (EO) unit is 90) to facilitate solubilization in water. This water-soluble derivative was designated Biocompatible Anchor for Membrane (BAM). Some proteins (streptavidin, EGFP and an antibody) were coupled with BAM90 at the distal terminal of PEG and rapidly (within a few minutes) anchored into the membranes of various cells (NIH3T3, 32D, Ba/F3, hybridoma 9E10). However, the anchored BAM90 disappeared from the cell membranes within 4,5 h in serum-free culture media, and moreover, the retention time of anchoring was shortened (1,2 h) in culture medium containing 10% FBS. We further prepared a dioleylphosphatidylethanolamine (DOPE)-PEG derivative (DOPE-BAM80, the EO unit is 80) as a double oleyl chain derivative for comparison with the single oleyl chain derivative, BAM90. The retention time of anchored DOPE-BAM80 was longer than that of BAM90 and more than 8 h in culture media with and without 10% serum. Furthermore, the treatment time of DOPE-BAM80 for anchoring was nearly as short (within a few minutes) as that of BAM90. In addition, both types of BAMs, BAM90 and DOPE-BAM80, showed no cytotoxicity. Therefore, DOPE-BAM80 is useful for protein anchoring to cells. Although the utilization of BAM90 is considered to be limited, it is expected to useful in restricted environments, for example, in tissues such as the cornea, peritoneum, bladder, and various mucosae, which are less exposed to serum. Thus, we suggest the possibility that both types of BAM can be applied to cell surface engineering. [source]

    Enzymatic Release of a Surface-Adsorbed RGD Therapeutic from a Cleavable Peptide Anchor

    CHEMMEDCHEM, Issue 11 2008
    Steven
    Implanted medical devices inevitably promote inflammation of the surrounding tissue. A method for enzymatically triggered localized drug delivery would have marked benefits in dealing with this response. Herein we present a rationally designed peptide coating for use with medical devices such as stents, that contains three distinct domains: 1),an implant-adsorptive sequence, 2),an enzymatically cleavable release mechanism, and 3),a therapeutic to be delivered. [source]

    Load-related implant reaction of mini-implants used for orthodontic anchorage

    CLINICAL ORAL IMPLANTS RESEARCH, Issue 4 2005
    André Büchter
    Abstract: The purpose of this study was to determine the clinical and biomechanical outcome of two different titanium mini-implant systems activated with different load regimens. A total of 200 mini-implants (102 Abso Anchor® and 98 Dual Top®) were placed in the mandible of eight Göttinger minipigs. Two implants each were immediately loaded in opposite direction by various forces (100, 300 or 500 cN) through tension coils. Additionally, three different distances between the neck of the implant and the bone rim (1, 2 and 3 mm) were used. The different load protocols were chosen to evaluate the load-related implant performance. The load was provided by superelastic tension coils, which are known to develop a virtually constant force. Non-loaded implants were used as a reference. Following an experimental loading period of 22 and 70 days half of the minipigs were sacrificed, and implant containing bone specimens evaluated for clinical performance and implant stability. Implant loosing was found to be statistically dependent on the tip moment (TM) at the bone rim. Clinical implant loosing were only present when load exceeded 900 cN mm. No movement of implants through the bone was found in the experimental groups, for any applied loads. Over the two experimental periods the non-loaded implants of one type of implant had a higher stability than those of the loaded implants. Dual Top® implants revealed a slightly higher removal torque compared with Abso Anchor® implants. Based on the results of this study, immediate loading of mini-implants can be performed without loss of stability when the load-related biomechanics do not exceed an upper limit of TM at the bone rim. Résumé Le but de cette étude a été de déterminer ce qui se passait cliniquement et biomécaniquement au niveau de deux systèmes de mini-implants en titane activés par différents régimes de mise en charge. Deux cents mini-implants (102 Abso Anchor® et 98 Dual Top®) ont été placés dans la mandibule de huit mini-porcs de Göttinger. Deux implants chacun ont été immédiatement mis en charge dans une direction opposée avec des forces variables (100 cN, 300 cN ou 500 cN) par des ressorts de tension. De plus trois distances différentes entre l'épaulement de l'implant et le rebord osseux (1, 2, 3 mm) ont été utilisés. Les différents protocoles de mise en charge ont été choisis pour évaluer la performance implantaire vis-à-vis de la mise en charge. Cette charge était produite par des ressorts de tension super-élastiques connues pour développer une force quasi-constante. Des implants sans charge ont servi de contrôle. Suivant une période de mise en charge de 22 et 70 jours la moitié des mini-porcs ont été euthanasiés et les spécimens comprenant l'os et l'implant évalués pour leur performance clinique et leur stabilité implantaire. La mobilité implantaire a été reconnue comme statisquement dépendante du moment de l'extrêmité au niveau du bord osseux. La mobilité implantaire clinique a seulement été rencontrée lorsque la charge dépassait 900 cN mm. Aucun mouvement des implants n'a été trouvée dans le groupe expérimental pour aucune des forces appliquées. Durant les deux périodes expérimentales les implants non-chargés d'un type d'implant avaient une stabilité supérieure à celle des implants chargés. Les implants Dual Top® avaient une force de torsion d'enlèvement un peu plus importante que les implants Abso Anchor®. La mise en charge immédiate de mini-implants peut être effectuée sans perte de stabilité lorsque la charge en relation avec la biomécanique n'excède pas une limite supérieure du moment de l'extrêmité au niveau du bord osseux. Zusammenfassung Es war das Ziel dieser Studie, die klinische und biomechanische Reaktion bei zwei verschiedenen Titan Mini-Implantat-Systemen, welche verschiedenen Belastungen ausgesetzt wurden, zu bestimmen. Insgesamt wurden 200 Mini-Implantate (102 Abso Anchor® und 98 Dual Top®) in die Unterkiefer von 8 Göttinger Minipigs eingesetzt. Immer zwei Implantate wurden jeweils sofort in entgegen gesetzter Richtung mit unterschiedlichen Kräften (100 cN, 300 cN oder 500 cN) durch Zugfedern belastet. Zusätzlich wurden drei verschiedene Abstände zwischen dem Hals des Implantats und der Knochenkante (1 mm, 2 mm, 3 mm) verwendet. Die unterschiedlichen Belastungsprotokolle wurden ausgewählt, um die belastungsbedingte Implantatreaktion auszuwerten. Die Belastung wurde mit superelastischen Zugfedern durchgeführt, welche dafür bekannt sind, dass sie eine relativ konstante Kraft entwickeln. Unbelastete Implantate dienten als Kontrolle. Nach einer experimentellen Belastungsdauer von 22 und 70 Tagen wurde je die Hälfte der Minipigs geopfert. An Knochenpräparaten mit Implantaten wurde die klinische Reaktion und die Stabilität der Implantate ausgewertet. Es wurde entdeckt, dass die Lockerung von Implantaten statistisch signifikant abhängig vom Kippmoment auf Höhe der Knochenkante war. Eine klinische Lockerung von Implantaten trat nur auf, wenn die Belastung 900 cN mm überstieg. Bei den experimentellen Gruppen konnte mit den applizierten Kräften keine Bewegung der Implantate durch den Knochen ausgelöst werden. Ueber die zwei Abschnitte des Experiments wiesen die nicht belasteten Implantate eines Typs eine grössere Stabilität als die belasteten Implantate auf. Die Dual Top® Implantate zeigten leicht höhere Ausdrehmomente als die Abso Anchor® Implantate. Aufgrund der Resultate dieser Studie kann eine Sofortbelastung von Mini-Implantaten ohne Stabilitätsverlust durchgeführt werden, sofern durch die Belastung die obere Grenze eines Kippmoments auf Höhe der Knochenkante nicht überschreitet. Resumen El propósito de este estudio fue determinar los resultados clínicos y biomecánicos de dos sistemas diferentes de mini-implantes de titanio activados con diferentes regimenes de carga. Se colocaron un total de 200 mini-implantes (102 Abso Anchor® y 98 Dual Top®) en la mandíbula de 8 minicerdos Göttinger. Se cargaron dos implantes inmediatamente en direcciones opuestas con varias fuerzas (100 cN, 300 cN o 500 cN) a través de resortes de tensión. Se usaron, adicionalmente, tres distancias diferentes entre el cuello del implante y el reborde óseo (1 mm, 2 mm, 3 mm). Los diferentes protocolos de carga se eligieron para evaluar el rendimiento relacionado con la carga. La carga se suministró por medio de resortes de tensión superelásticos, conocidos por desarrollar una fuerza virtualmente constante. Los implantes no cargados se usaron como referencia. Tras un periodo experimental de carga de 22 y 70 días la mitad de los minicerdos se sacrificaron, y se evaluaron los implantes conteniendo especímenes óseos para el rendimiento clínico y estabilidad de los implantes. El aflojamiento del implante se encontró que era estadísticamente dependiente de la punta del momento en el reborde óseo. El aflojamiento clínico del implante solo se presentó cuando la carga excedió los 900 cN mm. No se encontró movimiento de los implantes a través del hueso en los grupos experimentales, en ninguna de las cargas aplicadas. A lo largo de los dos periodos experimentales los implantes sin carga de un tipo de implante tuvieron una mayor estabilidad que aquellos de los implantes cargados. Los implantes Dual Top® necesitaron un mayor torque de remoción en comparación con los implantes Abso Anchor®. Basándose en los resultados de este estudio, la carga inmediata se puede llevar a cabo sin pérdida de estabilidad cuando la biomecánica relacionada con la carga no supere un límite superior de la punta del momento en el reborde óseo. [source]

    Double Butterfly Suture for High Tension: A Broadly Anchored, Horizontal, Buried Interrupted Suture

    DERMATOLOGIC SURGERY, Issue 3 2000
    Helmut Breuninger MD
    Background. The excision of skin lesions such as tumors, nevi, and scars frequently results in tension on surgical wound margins. This tension is commonly counteracted surgically with buried, intracutaneous, interrupted sutures of absorbable material which are anchored vertically in the corium. Method. The horizontal, buried, intracutaneous butterfly suture has been described elsewhere. It is firmly anchored in the corium, everts wound margins, and adapts them nearly as broadly as two vertical sutures. It can also be laid as a double butterfly suture, as described here, and then has the shape of an "8." This double butterfly suture is equivalent to three vertical sutures because of its broad base in the corium. Moreover, it can cope with much greater tension because of its "pulley" effect. A single double butterfly suture usually suffices for small defects, particularly when the wound edges are cut obliquely with a longer rim of epidermis. Materials. We have laid the traditional butterfly suture in more than 35,000 skin lesion excisions since 1985 and the double butterfly suture alone or as a supplement in more than 10,000 sutures since 1992. We use 2-0 to 6-0 polydioxanone for these procedures, since it has proven in trials to be the best-absorbed suture material. Results. In most cases, the resulting scars were narrow and smooth in spite of high tension. Results were unsatisfactory in only 6.2% of procedures. Conclusion. The double butterfly suture described here has the advantages of withstanding tension better while everting wound margins and requiring fewer stitches for wound closure. However, it is important that the suture knot be deeply anchored beneath the corium. [source]

    Carbon Nanotubes Anchored to Silicon for Device Fabrication

    ADVANCED MATERIALS, Issue 5 2010
    Kristina T. Constantopoulos
    Abstract This report highlights recent progress in the fabrication of vertically aligned carbon nanotubes (VA-CNTs) on silicon-based materials. Research into these nanostructured composite materials is spurred by the importance of silicon as a basis for most current devices and the disruptive properties of CNTs. Various CNT attachments methods of covalent and adsorptive nature are critically compared. Selected examples of device applications where the VA-CNT on silicon assemblies are showing particular promise are discussed. These applications include field emitters, filtration membranes, dry adhesives, sensors and scaffolds for biointerfaces. [source]

    Novel Face-Lift Suspension Suture and Inserting Instrument: Use of Large Anchors Knotted into a Suture with Attached Needle and Inserting Device Allowing for Single Entry Point Placement of Suspension Suture.

    DERMATOLOGIC SURGERY, Issue 3 2006
    Preliminary Report of 20 Cases with 6- to 12-Month Follow-Up
    BACKGROUND Various suspension suture techniques exist to elevate the mid-face, jowls, and neck. OBJECTIVE To assess safety and efficacy of a new suspension suture and inserting instrument with both standard and minimal incision (no-skin-excision) face-lifts. METHODS A new type of multianchor suspension suture assembled from commercially available 2-0 absorbable monofilament material, with 5 to 9 equally spaced knots through which are secured 7 to 9 mm bits of 0 thickness similar suture material, and an attached straightened needle, was used to elevate and suspend facial tissues to temporal or mastoid fascia. The suspension sutures are placed in the deep subcutaneous tissues, just above the superficial musculo aponeurotic system (SMAS), by use of a novel, blunt instrument, which does not require a second, distal exit point. The suspension suture distal end floats free. The proximal needle end is sutured to fascia. The suture was used on 20 patients. Fourteen of them underwent pure, "no-skin-excision," suspension lifts. Six had suspension suture elevation of the mid-face in conjunction with relatively conservative open lifts. Nine- to 12-month results were evaluated. RESULTS With open face-lifts, 9- to 12-month results are excellent with significant persistence of the correction initially achieved. Resulting scars remained fine line. There were no complications. With pure suspension lifts, initial results were impressive. By 6 months, correction started to fade. By 12 months 100% of initial correction for jowls, and 80 to 100% for mid-face, appeared lost. Recovery time was 2 to 4 days. There were no significant complications. CONCLUSION Large multianchor, absorbable monofilament sutures can safely and effectively enhance results of conservative lifts, with remarkable elevation of the mid-face not achievable with simple SMAS flaps. These suspension sutures can easily and safely achieve impressive, though relatively short-term results, with a minimal incision, "no-skin-excision" technique. [source]

    Inclusion of Anionic Guests inside a Molecular Cage with Palladium(II) Centers as Electrostatic Anchors,

    ANGEWANDTE CHEMIE, Issue 38 2009
    Guido
    Vier bananenförmige Liganden und zwei PdII -Ionen bauen quantitativ eine ballförmige Struktur mit vier großen Öffnungen auf (siehe Bild). Die beiden PdII -Ionen bilden mit Pyridindonoren der Liganden stabile quadratisch-planare Komplexe, sie können aber zusätzlich mit Anionen wechselwirken. Weil sie in einem bestimmten Abstand positioniert sind, der durch die starren Liganden vorgegeben ist, wirken die PdII -Ionen als elektrostatische Anker für dianionische Gäste entsprechender Größe. [source]

    Kurze Verankerungslängen mit Rechteckankern

    BETON- UND STAHLBETONBAU, Issue 1 2004
    Josef Hegger Prof. Dr.-Ing.
    Abstract In der Zulassung Z-15.6-204 [1] des Deutschen Instituts für Bautechnik werden Halfen HDB-E-Anker mit rechteckigen Köpfen als Endverankerung in Rahmenknoten und Konsolen für die Anwendung gemäß DIN 1045-1 und DIN 1045 geregelt. Durch die schlupfarme Verankerung der Zuggurtbewehrung ergeben sich Vorteile hinsichtlich der konstruktiven Durchbildung, der Tragfähigkeit und der Bauausführung. In diesem Beitrag werden die Zulassungsregelungen erläutert. Rectangular Anchors with short Anchorage Length The technical approval Z-15.6-204 [1] of the Deutsches Institut für Bautechnik gives design rules for the use of Halfen HDB-E-headed studs in exterior-beam-column-joints and corbels. The anchorage with headed studs is characterized by a negligible slippage of the reinforcement and is advantageous regarding the load bearing capacity, the detailing and the handling on site. This paper describes the design rules, devided from comprehensive experimental and numerical investigations [2]. [source]

    Diethylene Glycol Ether-Linked 3,4,5-Trihydroxybenzamides as Triply Branched Dendritic Anchors to CdSe/ZnS Core/Shell Type Nanoparticles: Potential Hydrophilic Fluorescent Probes.

    CHEMINFORM, Issue 34 2005
    Chien-Tien Chen
    No abstract is available for this article. [source]

    Oligomer-to-Polymer Transition in Short Ethylene Glycol Chains Connected to Mobile Hydrophobic Anchors

    CHEMPHYSCHEM, Issue 1 2005
    Motomu Tanaka Dr.
    Abstract We studied the structure of short ethylene glycol (EG) chains with N repeating units (EGN, N=3, 6, 9, 12, and 15) connected to hydrophobic dihexadecyl chains by means of a combination of differential scanning calorimetry (DSC) and small- and wide-angle X-ray scattering (SAXS/WAXS). These synthetic amphiphiles dispersed in water form planar lamellar stacks and hexagonal cylinders confining the EG chains to restricted geometries. Owing to the self-assembly of the anchoring points, the lateral density of EG chains in planar lamella can be quantitatively controlled. Furthermore, the chain-melting phase transition of the anchors enables us to "switch" the intermolecular distance reversibly. SAXS/WAXS results suggest that the shorter EG chains (N=3, 6, and 9) assume a helical conformation in stacks of planar lamella. When the EG chains are further elongated (N=12 and 15), the lamellar periodicities cannot be explained by a linear extrapolation of shorter oligomers, but can be interpreted well as polymer brushes following the scaling theorem. Such rich phase behaviors of EGN molecules can be used as a simple model of oligo/poly-saccharide chains on cell surfaces, which act not only as flexible repellers between neighboring cells but also as stable spacers for functional ligands. [source]

    Cross-cultural evaluation of the Panic Disorder Severity Scale in Japan

    DEPRESSION AND ANXIETY, Issue 1 2004
    Ikuyo Yamamoto M.D.
    Abstract The Panic Disorder Severity Scale (PDSS) [Shear et al., 1997] is rapidly gaining world-wide acceptance as a standard global severity measure of panic disorder, however, its cross-cultural validity and reliability have not been reported yet. We developed the Japanese version of the PDSS and examined its factor structure, internal consistency and inter-rater reliability and concurrent validity among Japanese patients with panic disorder with or without agoraphobia. We also established rules of thumb for interpreting PDSS total scores, taking the Clinical Global Impression severity scale as the anchoring criterion. The identical one-factor structure of the PDSS was confirmed among the Japanese patients as among the United States patients. Both internal and inter-rater reliability was excellent (Cronbach's alpha was 0.86, and ANOVA ICCs were all above 0.90). Concurrent validity of the PDSS items with self-report questionnaires tapping similar or overlapping domains was satisfactory (Pearson correlation coefficients were mostly above 0.5). Using the anchor-based approach, the following interpretative guides are suggested: among those with established panic disorder diagnosis, PDSS total scores up to 10 correspond with "mild," those between 11 and 15 with "moderate," and those at or above 16 correspond with "severe" panic disorder. The present findings support the cross-cultural generalizability of panic disorder symptomatology and of the PDSS, in particular. Depression and Anxiety 20:17,22, 2004. © 2004 Wiley-Liss, Inc. [source]

    Mutagenesis studies in transgenic Xenopus intermediate pituitary cells reveal structural elements necessary for correct prion protein biosynthesis

    DEVELOPMENTAL NEUROBIOLOGY, Issue 6 2007
    Jos W.G. van Rosmalen
    Abstract The cellular prion protein (PrPC) is generally accepted to be involved in the development of prion diseases, but its physiological role is still under debate. To obtain more insight into PrPC functioning, we here used stable Xenopus transgenesis in combination with the proopiomelanocortin (POMC) gene promoter to express mutated forms of Xenopus PrPC fused to the C-terminus of the green fluorescent protein (GFP) specifically in the neuroendocrine Xenopus intermediate pituitary melanotrope cells. Similar to GFP-PrPC, the newly synthesized GFP-PrPCK81A mutant protein was stepwise mono- and di-N-glycosylated to 48- and 51-kDa forms, respectively, and eventually complex glycosylated to yield a 55-kDa mature form. Unlike GFP-PrPC, the mature GFP-PrPCK81A mutant protein was not cleaved, demonstrating the endoproteolytic processing of Xenopus PrPC at lysine residue 81. Surprisingly, removal of the glycosylphosphatidylinositol (GPI) anchor signal sequence or insertion of an octarepeat still allowed N-linked glycosylation, but the GFP-PrPC,GPI and GFP-PrPCocta mutant proteins were not complex glycosylated and not cleaved, indicating that the GPI/octa mutants did not reach the mid-Golgi compartment of the secretory pathway. The transgene expression of the mutant proteins did not affect the ultrastructure of the melanotrope cells nor POMC biosynthesis and processing, or POMC-derived peptide secretion. Together, our findings reveal the evolutionary conservation of the site of metabolic cleavage and the importance of the presence of the GPI anchor and the absence of the octarepeat in Xenopus PrPC for its correct biosynthesis. © 2007 Wiley Periodicals, Inc. Develop Neurobiol, 2007. [source]

    The development of "roughness" in the play fighting of rats: A Laban Movement Analysis perspective

    DEVELOPMENTAL PSYCHOBIOLOGY, Issue 1 2003
    Afra Foroud
    Abstract With increasing age, rats, when play fighting, become rougher. In part, this change can be accounted for by the increasing likelihood of using adult-typical fighting tactics. However, even when using the same tactics, adults appear rougher than juveniles in their play. In this study, videotaped sequences of play fighting in rats from the juvenile (30 days) to the post-pubertal (70 days) period were analyzed using Laban Movement Analysis (LMA). Movement qualities called Effort Factors in LMA captured the character of some of this change. Juveniles tended to use Indulging Efforts, whereas older rats tended to use Condensing Efforts. The latter are related to performing movements that are more controlled. This greater level of control was also evident in the way older rats maintained postural support during play fights. When standing over supine partners, juveniles are more likely to stand on the partner with all four paws, reducing their postural stability, and hence ability to control their partner's movements. Older rats are more likely to place their hind paws on the ground, thus providing a firmer anchor for movements with their upper bodies and forepaws. These age-related changes in behavior were found for both males and females. The findings lend support to a growing body of evidence that play fighting in the juvenile phase of rats is not just a more frequently occurring version of that present in adults, but rather, has unique organizational properties. © 2003 Wiley Periodicals, Inc. Dev Psychobiol 42: 35,43, 2003. [source]

    Expression of PRiMA in the mouse brain: membrane anchoring and accumulation of ,tailed' acetylcholinesterase

    EUROPEAN JOURNAL OF NEUROSCIENCE, Issue 7 2003
    Noël A. Perrier
    Abstract We analysed the expression of PRiMA (proline-rich membrane anchor), the membrane anchor of acetylcholinesterase (AChE), by in situ hybridization in the mouse brain. We compared the pattern of PRiMA transcripts with that of AChE transcripts, as well as those of choline acetyltransferase and M1 muscarinic receptors which are considered pre- and postsynaptic cholinergic markers. We also analysed cholinesterase activity and its molecular forms in several brain structures. The results suggest that PRiMA expression is predominantly or exclusively related to the cholinergic system and that anchoring of cholinesterases to cell membranes by PRiMA represents a limiting factor for production of the AChE tailed splice variant (AChET),PRiMA complex, which represents the major AChE component in the brain. This enzyme species is mostly associated with cholinergic neurons because the pattern of PRiMA mRNA expression largely coincides with that of ChAT. We also show that, in both mouse and human, PRiMA proteins exist as two alternative splice variants which differ in their cytoplasmic regions. [source]

    Material stiffness, branching pattern and soil matric potential affect the pullout resistance of model root systems

    EUROPEAN JOURNAL OF SOIL SCIENCE, Issue 6 2007
    S. B. Mickovski
    Summary Understanding of the detailed mechanisms of how roots anchor in and reinforce soil is complicated by the variability and complexity of both materials. This study controlled material stiffness and architecture of root analogues, by using rubber and wood, and also employed real willow root segments, to investigate the effect on pullout resistance in wet and air-dry sand. The architecture of model roots included either no laterals (tap-root) or a single pair at two different locations (herringbone and dichotomous). During pullout tests, data on load and displacement were recorded. These studies were combined with Particle Image Velocimetry (PIV) image analysis of the model root-soil system at a transparent interface during pullout to increase understanding of mechanical interactions along the root. Model rubber roots with small stiffness had increasing pullout resistance as the branching and the depth of the lateral roots increased. Similarly, with the stiff wooden root models, the models with lateral roots embedded deeper showed greatest resistance. PIV showed that rubber model roots mobilized their interface shear strength progressively whilst rigid roots mobilized it equally and more rapidly over the whole root length. Soil water suction increased the pullout resistance of the roots by increasing the effective stress and soil strength. Separate pullout tests conducted on willow root samples embedded in sand showed similar behaviour to the rigid model roots. These tests also demonstrated the effect of the root curvature and rough interface on the maximum pullout resistance. [source]

    A NOT SO HAPPY BIRTHDAY: THE FOSTER YOUTH TRANSITION FROM ADOLESCENCE INTO ADULTHOOD

    FAMILY COURT REVIEW, Issue 2 2010
    Miriam Aroni Krinsky
    Every year close to 25,000 youth age out of our foster care system; without the anchor of a family, former foster youth disproportionately join the ranks of the homeless, incarcerated, and unemployed. While the average age of financial independence in America is twenty-six years of age, we presume that foster youth can somehow attain financial and emotional independence by age eighteen. Instead, these adolescents are woefully unprepared for independent adult life, and when they falter, too often no one is there to provide support or guidance. As a result, former foster youth are ten times more likely to be arrested than youth of the same age, race, and sex and one in four youth who age out of foster care will end up in jail within the first two years after leaving care. This article will discuss strategies for changing these disheartening outcomes for transitioning foster youth, including breaking down our silos and collectively taking charge of the lives of children in our care; keeping a watchful eye on data and outcomes and using that information to guide our actions; ensuring that the voices of youth are an ever-present part of decisions and processes that will chart their future; and educating ourselves about best practices and new approaches. This article also discusses new opportunities that now exist to support foster youth as they move into adulthood, including new federal legislation that,for the first time,will allow states to support foster youth beyond age eighteen. Finally, this article provides a backdrop for this Special Issue and summarizes the insightful articles and innovative thinking contained herein. [source]

    Secondary structure of lipidated Ras bound to a lipid bilayer

    FEBS JOURNAL, Issue 23 2008
    Jörn Güldenhaupt
    Ras proteins are small guanine nucleotide binding proteins that regulate many cellular processes, including growth control. They undergo distinct post-translational lipid modifications that are required for appropriate targeting to membranes. This, in turn, is critical for Ras biological function. However, most in vitro studies have been conducted on nonlipidated truncated forms of Ras proteins. Here, for the first time, attenuated total reflectance-FTIR studies of lipid-modified membrane-bound N-Ras are performed, and compared with nonlipidated truncated Ras in solution. For these studies, lipidated N-Ras was prepared by linking a farnesylated and hexadecylated N-Ras lipopeptide to a truncated N-Ras protein (residues 1,181). It was then bound to a 1-palmitoyl-2-oleoyl- sn -glycero-3-phosphocholine bilayer tethered on an attenuated total reflectance crystal. The structurally sensitive amide I absorbance band in the IR was detected and analysed to determine the secondary structure of the protein. The NMR three-dimensional structure of truncated Ras was used to calibrate the contributions of the different secondary structural elements to the amide I absorbance band of truncated Ras. Using this novel approach, the correct decomposition was selected from several possible solutions. The same parameter set was then used for the membrane-bound lipidated Ras, and provided a reliable decomposition for the membrane-bound form in comparison with truncated Ras. This comparison indicates that the secondary structure of membrane-bound Ras is similar to that determined for the nonlipidated truncated Ras protein for the highly conserved G-domain. This result validates the multitude of investigations of truncated Ras without anchor in vitro. The novel attenuated total reflectance approach opens the way for detailed studies of the interaction network of the membrane-bound Ras protein. [source]

    Characterization of membrane-bound prolyl endopeptidase from brain

    FEBS JOURNAL, Issue 17 2008
    Jofre Tenorio-Laranga
    Prolyl oligopeptidase (POP) is a serine protease that cleaves small peptides at the carboxyl side of an internal proline residue. Substance P, arginine,vasopressin, thyroliberin and gonadoliberin are proposed physiological substrates of this protease. POP has been implicated in a variety of brain processes, including learning, memory, and mood regulation, as well as in pathologies such as neurodegeneration, hypertension, and psychiatric disorders. Although POP has been considered to be a soluble cytoplasmic peptidase, significant levels of activity have been detected in membranes and in extracellular fluids such as serum, cerebrospinal fluid, seminal fluid, and urine, suggesting the existence of noncytoplasmic forms. Furthermore, a closely associated membrane prolyl endopeptidase (PE) activity has been previously detected in synaptosomes and shown to be different from the cytoplasmic POP activity. Here we isolated, purified and characterized this membrane-bound PE, herein referred to as mPOP. Although, when attached to membranes, mPOP presents certain features that distinguish it from the classical POP, our results indicate that this protein has the same amino acid sequence as POP except for the possible addition of a hydrophobic membrane anchor. The kinetic properties of detergent-soluble mPOP are fully comparable to those of POP; however, when attached to the membranes in its natural conformation, mPOP is significantly less active and, moreover, it migrates anomalously in SDS/PAGE. Our results are the first to show that membrane-bound and cytoplasmic POP are encoded by variants of the same gene. [source]

    Hypoxia induces expression of a GPI-anchorless splice variant of the prion protein

    FEBS JOURNAL, Issue 11 2008
    Yutaka Kikuchi
    The human prion protein (PrP) is a glycoprotein with a glycosylphosphatidylinositol (GPI) anchor at its C-terminus. Here we report alternative splicing within exon 2 of the PrP gene (PRNP) in the human glioblastoma cell line T98G. The open reading frame of the alternatively spliced mRNA lacked the GPI anchor signal sequence and encoded a 230 amino acid polypeptide. Its product, GPI-anchorless PrP (GPI, PrPSV), was unglycosylated and soluble in non-ionic detergent, and was found in the cytosolic fraction. We also detected low levels of alternatively spliced mRNA in human brain and non-neuronal tissues. When long-term passaged T98G cells were placed in a low-oxygen environment, alternatively spliced mRNA expression increased and expression of normally spliced PrP mRNA decreased. These findings imply that oxygen tension regulates GPI, PrPSV expression in T98G cells. [source]

    Synthesis and structural characterization of a mimetic membrane-anchored prion protein

    FEBS JOURNAL, Issue 6 2006
    Matthew R. Hicks
    During pathogenesis of transmissible spongiform encephalopathies (TSEs) an abnormal form (PrPSc) of the host encoded prion protein (PrPC) accumulates in insoluble fibrils and plaques. The two forms of PrP appear to have identical covalent structures, but differ in secondary and tertiary structure. Both PrPC and PrPSc have glycosylphospatidylinositol (GPI) anchors through which the protein is tethered to cell membranes. Membrane attachment has been suggested to play a role in the conversion of PrPC to PrPSc, but the majority of in vitro studies of the function, structure, folding and stability of PrP use recombinant protein lacking the GPI anchor. In order to study the effects of membranes on the structure of PrP, we synthesized a GPI anchor mimetic (GPIm), which we have covalently coupled to a genetically engineered cysteine residue at the C-terminus of recombinant PrP. The lipid anchor places the protein at the same distance from the membrane as does the naturally occurring GPI anchor. We demonstrate that PrP coupled to GPIm (PrP,GPIm) inserts into model lipid membranes and that structural information can be obtained from this membrane-anchored PrP. We show that the structure of PrP,GPIm reconstituted in phosphatidylcholine and raft membranes resembles that of PrP, without a GPI anchor, in solution. The results provide experimental evidence in support of previous suggestions that NMR structures of soluble, anchor-free forms of PrP represent the structure of cellular, membrane-anchored PrP. The availability of a lipid-anchored construct of PrP provides a unique model to investigate the effects of different lipid environments on the structure and conversion mechanisms of PrP. [source]

    The effect of HAMP domains on class IIIb adenylyl cyclases from Mycobacterium tuberculosis

    FEBS JOURNAL, Issue 12 2004
    Jürgen U. Linder
    The genes Rv1318c, Rv1319c, Rv1320c and Rv3645 of Mycobacterium tuberculosis are predicted to code for four out of 15 adenylyl cyclases in this pathogen. The proteins consist of a membrane anchor, a HAMP region and a class IIIb adenylyl cyclase catalytic domain. Expression and purification of the isolated catalytic domains yielded adenylyl cyclase activity for all four recombinant proteins. Expression of the HAMP region fused to the catalytic domain increased activity in Rv3645 21-fold and slightly reduced activity in Rv1319c by 70%, demonstrating isoform-specific effects of the HAMP domains. Point mutations were generated to remove predicted hydrophobic protein surfaces in the HAMP domains. The mutations further stimulated activity in Rv3645 eight-fold, whereas the effect on Rv1319c was marginal. Thus HAMP domains can act directly as modulators of adenylyl cyclase activity. The modulatory properties of the HAMP domains were confirmed by swapping them between Rv1319c and Rv3645. The data indicate that in the mycobacterial adenylyl cyclases the HAMP domains do not display a uniform regulatory input but instead each form a distinct signaling unit with its adjoining catalytic domain. [source]

    Analysis of Usp DNA binding domain targeting reveals critical determinants of the ecdysone receptor complex interaction with the response element

    FEBS JOURNAL, Issue 13 2001
    Iwona Grad
    The steroid hormone, 20-hydroxyecdysone (20E), directs Drosophila metamorphosis via a heterodimeric receptor formed by two members of the nuclear hormone receptors superfamily, the product of the EcR (EcR) and of the ultraspiracle (Usp) genes. Our previous study [Niedziela-Majka, A., Kochman, M., O,yhar, A. (2000) Eur. J. Biochem.267, 507,519] on EcR and Usp DNA-binding domains (EcRDBD and UspDBD, respectively) suggested that UspDBD may act as a specific anchor that preferentially binds the 5, half-site of the pseudo-palindromic response element from the hsp27 gene promoter and thus locates the heterocomplex in the defined orientation. Here, we analyzed in detail the determinants of the UspDBD interaction with the hsp27 element. The roles of individual amino acids in the putative DNA recognition , helix and the roles of the base pairs of the UspDBD target sequence have been probed by site-directed mutagenesis. The results show how the hsp27 element specifies UspDBD binding and thus the polar assembly of the UspDBD/EcRDBD heterocomplex. It is suggested how possible nucleotide deviations within the 5, half-site of the element may be used for the fine-tuning of the 20E-response element specificity and consequently the physiological response. [source]

    Assembly of cytochrome f into the cytochrome bf complex in isolated pea chloroplasts

    FEBS JOURNAL, Issue 3 2001
    Ruth M. Mould
    Structural features of cytochrome f necessary for assembly into the cytochrome bf complex were examined in isolated pea chloroplasts following import of 35S-labelled chimeric precursor proteins, consisting of the presequence of the small subunit of Rubisco fused to the turnip cytochrome f precursor. Assembly was detected by nondenaturing gel electrophoresis of dodecyl maltoside-solubilized thylakoid membranes. A cytochrome f polypeptide unable to bind haem because of mutagenesis of Cys21 and Cys24 to alanine residues was assembled into the complex and had similar stability to the wild-type polypeptide. This indicates that covalent haem binding to cytochrome f is not necessary for assembly of the protein into the cytochrome bf complex. A truncated protein lacking the C-terminal 33 amino acid residues, including the transmembrane span and the stroma-exposed region, was translocated across the thylakoid membrane, had a similar stability to wild-type cytochrome f but was not assembled into the complex. This indicates that the C-terminal region of cytochrome f is important for assembly into the complex. A mutant cytochrome f unable to bind haem and lacking the C-terminal region was also translocated across the thylakoid membrane but was extremely labile, indicating that, in the absence of the C-terminal membrane anchor, haem-less cytochrome f is recognized by a thylakoid proteolytic system. [source]

    Mass spectrometry study of ecto-5,-nucleotidase from bull seminal plasma

    FEBS JOURNAL, Issue 16 2000
    Carlo Fini
    The structure of ecto-5,-nucleotidase from bull seminal plasma, containing a glycosyl-phosphatidylinositol anchor, was studied using mass spectrometry. MALDI-MS analysis of intact protein indicated a mass of 65 568.2 Da for the monomeric form, and it also showed a heterogeneous population of glycoforms with the glycosidic moiety accounting for ,,6000 Da. MALDI-MS analysis showed that Asn53, Asn311, Asn333 and Asn403 were four sites of N -glycosylation. GC-MS analysis provided information on the glycosidic structures linked to the four asparagines. Asn53, Asn311 and Asn333 were linked to high-mannose saccharide chains, whereas the glycan chains linked to Asn403 contained a heterogeneous mixture of oligosaccharides, the high-mannose type structure being the most abundant and hybrid or complex type glycans being minor components. By combining enzymatic and/or chemical hydrolysis with GC-MS analysis, detailed characterization of the glycosyl-phpsphatidylinositol anchor was obtained. MALDI spectral analysis indicated that the glycosyl-phosphatidylinositol core contained EtN(P)Man3GlcNH2 -myo-inositol(P)-glycerol, principally modified by stearoyl and palmitoyl residues or by stearoyl and myristoyl residues to a minor extent. Moreover, 1-palmitoylglycerol and 1-stearoylglycerol outweighed 2-palmitoylglycerol and 2-stearoylglycerol. The combination of chemical and enzymatic digestions of the protein with the mass spectral analysis yielded a complete pattern of S,S bridges. The protein does not contain free thiols and its eight cysteines are linked by intramolecular disulfide bonds, the pairs being: Cys51,Cys57, Cys353,Cys358, Cys365,Cys387 and Cys476,Cys479. This work resolves details of the structure of ecto-5,-nucleotidase, with particular regard to the localization and composition of the glycidic moiety, number and localization of the disulfide bridges and characterization of the glycosyl-phosphatidylinositol anchor. [source]

    The structure of the lipid anchor of Campylobacter jejuni polysaccharide

    FEMS MICROBIOLOGY LETTERS, Issue 2 2006
    Adrian T. Corcoran
    Abstract Campylobacter jejuni is a leading cause of gastroenteritis in humans. Campylobacter jejuni produces extracellular polysaccharides that have been characterized structurally and shown to be independent of lipopolysaccharides. Furthermore, it has been suggested that these C. jejuni polysaccharides are capsular in nature, although their lipid anchor has not been identified. In this report, the occurrence of a lipid-linked capsular-like polysaccharide in C. jejuni is conclusively shown, and the lipid anchor identified as dipalmitoyl-glycerophosphate. [source]

    Cadherin 13 in cancer

    GENES, CHROMOSOMES AND CANCER, Issue 9 2010
    Alexandra V. Andreeva
    We review the evidence suggesting the involvement of Cadherin 13 (CDH13, T-cadherin, H-cadherin) in various cancers. CDH13 is an atypical member of the cadherin family, devoid of a transmembrane domain and anchored to the exterior surface of the plasma membrane via a glycosylphosphatidylinositol anchor. CDH13 is thought to affect cellular behavior largely through its signaling properties. It is often down-regulated in cancerous cells. CDH13 down-regulation has been associated with poorer prognosis in various carcinomas, such as lung, ovarian, cervical and prostate cancer. CDH13 re-expression in most cancer cell lines inhibits cell proliferation and invasiveness, increases susceptibility to apoptosis, and reduces tumor growth in in vivo models. These properties suggest that CDH13 may represent a possible target for therapy in some cancers. At the same time, CDH13 is up-regulated in blood vessels growing through tumors and promotes tumor neovascularization. In contrast to most cancer cell lines, CDH13 overexpression in endothelial cells promotes their proliferation and migration, and has a pro-survival effect. We also discuss molecular mechanisms that may regulate CDH13 expression and underlie its roles in cancer. © 2010 Wiley-Liss, Inc. [source]