bluuebunny/crossref_metadata_2025_split huggingface dataset:
Relating nucleotide‐dependent conformational changes in free tubulin dimers to tubulin assembly
Authors: Natarajan Kathiresan , Mohan Jagan , Senapati Sanjib 
Published: September 2012

AbstractThe complex dynamic behavior of microtubules (MTs) is believed to be primarily due to the αβ‐tubulin dimer architecture and its intrinsic GTPase activity. Hence, a detailed knowledge of the conformational variations of isolated α‐GTP‐β‐GTP‐ and α‐GTP‐β‐GDP‐tubulin dimers in solution and their implications to interdimer interactions and stability is directly relevant to understand the MT dynamics. An attempt has been made here by combining molecular dynamics (MD) simulations and protein–protein docking studies that unravels key structural features of tubulin dimer in different nucleotide states and correlates their association to tubulin assembly. Results from simulations suggest that tubulin dimers and oligomers attain curved conformations in both GTP and GDP states. Results also indicate that the tubulin C‐terminal domain and the nucleotide state are closely linked. Protein–protein docking in combination with MD simulations suggest that the GTP‐tubulin dimers engage in relatively stronger interdimer interactions even though the interdimer interfaces are bent in both GTP and GDP tubulin complexes, providing valuable insights on in vitro finding that GTP‐tubulin is a better assembly candidate than GDP‐tubulin during the MT nucleation and elongation processes. © 2012 Wiley Periodicals, Inc. Biopolymers 99: 282–291, 2013.
The Effects of Substituents on the Geometry of π–π Interactions
Authors: Snyder Seth E. , Huang Bin‐Syuan , Chu Yu W. , Lin Huei‐Shian , Carey James R. 
Published: September 2012

AbstractWe have designed and utilized a simple molecular recognition system to study the substituent effects in aromatic interactions. Recently, we showed that 3‐ and 3,5‐disubstituted benzoyl leucine diethyl amides with aromatic rings of varying electronic character organized into homochiral dimers in the solid state through a parallel displaced π–π interaction and two hydrogen bonds, but no such homochiral dimerization was observed for the unsubstituted case. This phenomenon supports the hypothesis that substituents stabilize π–π interactions regardless of their electronic character. To further investigate the origin of substituent effects for π–π interactions, we synthesized and crystallized a series of 4‐substituted benzoyl leucine diethyl amides. Surprisingly, only two of the 4‐substituted compounds formed homochiral dimers. A comparison among the 4‐substituted compounds that crystallized as homochiral dimers and their 3‐substituted counterparts revealed that there are differences in regard to the geometry of the aromatic rings with respect to each other, which depend on the electronic nature and location of the substituent. The crystal structures of the homochiral dimers that showed evidence of direct, local interactions between the substituents on the aromatic rings also displayed nonequivalent dihedral angles in the individual monomers. The crystallographic data suggests that such “flexing” may be the result of the individual molecules orienting themselves to maximize the local dipole interactions on the respective aromatic rings. The results presented here can potentially have broad applicability towards the development of molecular recognition systems that involve aromatic interactions.
Facile Access to Silicon‐Functionalized Bis‐Silylene Titanium(II) Complexes
Authors: Blom Burgert , Driess Matthias , Gallego Daniel , Inoue Shigeyoshi 
Published: September 2012

AbstractA series of unprecedented bis‐silylene titanium(II) complexes of the type [(η5‐C5H5)2Ti(LSiX)2] (L=PhC(NtBu)2; X=Cl, CH3, H) has been prepared using a phosphane elimination strategy. Treatment of the [(η5‐C5H5)2Ti(PMe3)2] precursor (1) with two molar equivalents of the N‐heterocyclic chlorosilylene LSiCl (2), results in [(η5‐C5H5)2Ti(LSiCl)2] (3) with concomitant PMe3 elimination. The presence of a SiCl bond in 3 enabled further functionalization at the silicon(II) center. Accordingly, a salt metathesis reaction of 3 with two equivalents of MeLi results in [(η5‐C5H5)2Ti(LSiMe)2] (4). Similarly, the reaction of 3 with two equivalents of LiBHEt3 results in [(η5‐C5H5)2Ti(LSiH)2] (5), which represents the first example of a bis‐(hydridosilylene) metal complex. All complexes were fully characterized and the structures of 3 and 4 elucidated by single‐crystal X‐ray diffraction analysis. DFT calculations of complexes 3–5 were also carried out to assess the nature of the titanium–silicon bonds. Two σ and one π‐type molecular orbital, delocalized over the Si‐Ti‐Si framework, are observed.
Expression of Pannexin1 in the outer plexiform layer of the mouse retina and physiological impact of its knockout
Authors: Kranz Katharina , Dorgau Birthe , Pottek Mark , Herrling Regina , Schultz Konrad , Bolte Petra , Monyer Hannah , Penuela Silvia , Laird Dale W. , Dedek Karin , Weiler Reto , Janssen‐Bienhold Ulrike 
Published: September 2012

AbstractPannexin1 (Panx1) belongs to a class of vertebrate proteins that exhibits sequence homology to innexins, the invertebrate gap junction proteins, and which also shares topological similarities with vertebrate gap junction proteins, the connexins. Unlike gap junctional channels, Panx1 forms single‐membrane channels, whose functional role in neuronal circuits is still unsettled. We therefore investigated the subcellular distribution of Panx1 in the mouse retina of wildtype and Panx1‐null mice by reverse‐transcription polymerase chain reaction (RT‐PCR), immunohistochemistry, and electron microscopy. Use of Panx1‐deficient mice served as a model to assess the physiological role of Panx1 by electroretinographic recordings and also to ensure the specificity of the anti‐Panx1 antibody labeling. Expression of Panx1 was found in type 3a OFF bipolar cells and in dendrites and axonal processes of horizontal cells. Panx1 was also found in horizontal cell dendrites representing the lateral elements of the triad synapse at cone and rod terminals. In vivo electroretinography of Panx1 knockout mice indicated an increased a‐ and b‐wave compared to Panx1 wildtype mice under scotopic conditions. The effect on the b‐wave was confirmed by in vitro electroretinograms from the inner retina. These results suggest that Panx1 channels serve as sinks for extracellular current flow making them possible candidates for the mediation of feedback from horizontal cells to photoreceptors. J. Comp. Neurol. 521:1119–1135, 2013. © 2012 Wiley Periodicals, Inc.
Synthesis of Cyclic N‐Tosyliminocarbonates by Lewis Acid Catalyzed Allylic Substitution of Trichloroacetimidates
Authors: Grigorjeva Liene , Jirgensons Aigars 
Published: September 2012

AbstractAllylic trichloroacetimidates bearing a δ‐N‐tosylcarbamoyloxy group were prepared in two steps from the corresponding diols, and their Brønsted and Lewis acid catalyzed cyclization reactions were investigated. It was found that N‐tosylcarbamates derived from secondary and tertiary alcohols bearing alkyl substituents undergo a chemoselective allylic alkylation to give N‐tosyliminocarbonates in good isolated yields. In turn, aryl‐substituted substrates tend to give oxazolines by abstraction of the carbamate functionality. The cyclization of N‐tosylcarbamates derived from secondary alcohols preferentially give trans‐iminocarbonates. However, the trans selectivity varied and depended on the substitution pattern, configuration of the substrate, and the catalyst. A high trans selectivity could be achieved from (E) substrates by using TMSOTf as the catalyst. The synthetic utility of iminocarbonates was demonstrated by transforming them into 1,2‐diols and cyclic carbonates as well as into N‐tosyloxazolidinones by a halide ion‐induced rearrangement.
Identification of CUX1 as the recurrent chromosomal band 7q22 target gene in human uterine leiomyoma
Authors: Schoenmakers Eric F. P. M. , Bunt Jens , Hermers Lianne , Schepens Marga , Merkx Gerard , Janssen Bert , Kersten Monique , Huys Erik , Pauwels Patrick , Debiec‐Rychter Maria , van Kessel Ad Geurts 
Published: September 2012

AbstractUterine leiomyomas are benign solid tumors of mesenchymal origin which occur with an estimated incidence of up to 77% of all women of reproductive age. The majority of these tumors remains symptomless, but in about a quarter of cases they cause leiomyoma‐associated symptoms including chronic pelvic pain, menorrhagia‐induced anemia, and impaired fertility. As a consequence, they are the most common indication for pre‐menopausal hysterectomy in the USA and Japan and annually translate into a multibillion dollar healthcare problem. Approximately 40% of these neoplasms present with recurring structural cytogenetic anomalies, including del(7)(q22), t(12;14)(q15;q24), t(1;2)(p36;p24), and anomalies affecting 6p21 and/or 10q22. Using positional cloning strategies, we and others previously identified HMGA1, HMGA2,
RAD51L1,
MORF, and, more recently, NCOA1 as primary target (fusion) genes associated with tumor initiation in four of these distinct cytogenetic subgroups. Despite the fact that the del(7)(q22) subgroup is the largest among leiomyomas, and was first described more than twenty years ago, the 7q22 leiomyoma target gene still awaits unequivocal identification. We here describe a positional cloning effort from two independent uterine leiomyomas, containing respectively a pericentric and a paracentric chromosomal inversion, both affecting band 7q22. We found that both chromosomal inversions target the cut‐like homeobox 1 (CUX1) gene on chromosomal band 7q22.1 in a way which is functionally equivalent to the more frequently observed del(7q) cases, and which is compatible with a mono‐allelic knock‐out scenario, similar as was previously described for the cytogenetic subgroup showing chromosome 14q involvement. © 2012 Wiley Periodicals, Inc.
Metastatic papillary thyroid cancer with lateral neck disease: Pattern of spread by level
Authors: Merdad Mazin , Eskander Antoine , Kroeker Teresa , Freeman Jeremy L. 
Published: September 2012

BackgroundCurrently, there is no clear consensus on the extent of this lateral neck dissection required in papillary thyroid cancer (PTC) with lateral neck metastasis. The purpose of this study was to review our experience with metastatic PTC, and identify the pattern of lymphatic spread to the lateral neck.MethodsA retrospective medical chart review of PTC patients treated with lateral neck dissection (levels II–Vb) at our institution between January 2004 and 2011. A total of 185 patients underwent 248 selective lateral neck dissections.ResultsLevels II, III, IV, and Vb were respectively involved in 49.3%, 76.6%, 61.6%, and 29.2% of cases.ConclusionWe advocate for a routine excision of levels II, III, IV, and Vb in PTC with metastasize to any lateral neck level. Although we have routinely dissected level IIb, it may be appropriate to omit its dissection, as well as level Va, when there are no clinical, radiologic, or intraoperative evidence of disease involving these sublevels. © 2012 Wiley Periodicals, Inc. Head Neck 35: 1439–1442, 2013
Giant papillary carcinoma arising in the ectopic buccal thyroid tissue
Authors: Elsurer Cagdas , Ozturk Kayhan , Baba Fusun , Yavas Cagdas , Bulut Serap 
Published: September 2012

BackgroundEctopic thyroid tissue very rarely occurs in the buccal region. Even more rarely encountered is the papillary carcinoma arising in the ectopic tissue.Methods and ResultsWe herein present a 78‐year‐old female patient admitted with a giant, buccal mass that developed within the previous 2 years. Physical examination revealed a vegetative mass on the left buccal region without any cervical lymphadenopathy. Magnetic resonance imaging scan showed an 8‐ × 6‐cm solid mass with cystic components in the left buccal region and thoracic computed tomography scanning revealed pulmonary metastasis. A successful surgery including lower lip splitting was performed, and the mass was totally excised with its surrounding capsule. Histopathologic examination revealed follicular variant of papillary carcinoma of the ectopic thyroid tissue.ConclusionsTo our knowledge, our case is the first case of papillary carcinoma arising from ectopic thyroid tissue in the buccal region in the literature. © 2012 Wiley Periodicals, Inc. Head Neck 35: E308–E309, 2013
Cancer net survival on registry data: Use of the new unbiased Pohar‐Perme estimator and magnitude of the bias with the classical methods
Authors: Roche Laurent , Danieli Coraline , Belot Aurélien , Grosclaude Pascale , Bouvier Anne‐Marie , Velten Michel , Iwaz Jean , Remontet Laurent , Bossard Nadine 
Published: September 2012

AbstractNet survival, the survival which might occur if cancer was the only cause of death, is a major epidemiological indicator required for international or temporal comparisons. Recent findings have shown that all classical methods used for routine estimation of net survival from cancer‐registry data, sometimes called “relative‐survival methods,” provide biased estimates. Meanwhile, an unbiased estimator, the Pohar‐Perme estimator (PPE), was recently proposed. Using real data, we investigated the magnitude of the errors made by four “relative‐survival” methods (Ederer I, Hakulinen, Ederer II and a univariable regression model) vs. PPE as reference and examined the influence of time of follow‐up, cancer prognosis, and age on the errors made. The data concerned seven cancer sites (2,51,316 cases) collected by FRANCIM cancer registries. Net survivals were estimated at 5, 10 and 15 years postdiagnosis. At 5 years, the errors were generally small. At 10 years, in good‐prognosis cancers, the errors made in nonstandardized estimates with all classical methods were generally great (+2.7 to +9% points in prostate cancer) and increased in age‐class estimations (vs. 5‐year ones). At 15 years, in bad‐ or average‐prognosis cancers, the errors were often substantial whatever the nature of the estimation. In good‐prognosis cancers, the errors in nonstandardized estimates of all classical methods were great and sometimes very important. With all classical methods, great errors occurred in age‐class estimates resulting in errors in age‐standardized estimates (+0.4 to +3.2% points in breast cancer). In estimating net survival, cancer registries should abandon all classical methods and adopt the new Pohar‐Perme estimator.
Autologous bone marrow stromal cells loaded onto porous gelatin scaffolds containing Drynaria fortunei extract for bone repair
Authors: Chen Kuo‐Yu , Dong Guo‐Chung , Hsu Chin‐Yin , Chen Yueh‐Sheng , Yao Chun‐Hsu 
Published: September 2012

AbstractGGT‐GSB composite was prepared by mixing a biodegradable GGT composite containing genipin‐crosslinked gelatin and β‐tricalcium phosphate with Gu‐Sui‐Bu extract (GSB) (Drynaria fortunei (Kunze) J. Sm.), a traditional Chinese medicine. Then, porous GGT and GGT‐GSB scaffolds were fabricated using a salt‐leaching method. The GGT and GGT‐GSB scaffolds thus obtained had a macroporous structure and high porosity. Rabbit bone marrow stromal cells (BMSCs) were seeded onto GGT and GGT‐GSB scaffolds. The biological response of rabbit calvarial bone to these scaffolds was considered to evaluate the potential of the scaffolds for use in bone tissue engineering. After 8 weeks of implantation, each scaffold induced new bone formation at a cranial bone defect, as was verified by X‐ray microradiography. The BMSC‐seeded GGT‐GSB scaffolds induced more new bone formation than the BMSC‐seeded GGT and acellular scaffolds. These observations suggest that an autologous BMSCs‐seeded porous GGT‐GSB scaffold can be adopted in bone engineering in vivo and has great potential for regenerating defective bone tissue. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2013.
Plasma treatment of electrospun PCL random nanofiber meshes (NFMs) for biological property improvement
Authors: Yan D. , Jones J. , Yuan X.Y. , Xu X.H. , Sheng J. , Lee J.C.‐M. , Ma G.Q. , Yu Q.S. 
Published: September 2012

AbstractIn this article, the plasma surface modification effects on the chemical, mechanical, and biological properties of electrospun poly (ε‐caprolactone) (PCL) random nanofiber meshes (NFMs) were investigated by adjusting plasma chemistry, that is, using glow discharges of N2+H2, NH3+O2, and Ar+O2 gas mixtures. The surface property changes of electrospun PCL NFMs after those plasma treatments were examined by water contact angle measurements and X‐ray photoelectron spectroscopy. The experimental results showed that the plasma treatments introduced polar groups onto the surfaces and thus increased the surface hydrophilicity. From tensile test data, plasma treatment had limited effect on the mechanical properties of PCL random NFMs. The biological properties of the plasma‐treated PCL NFMs were examined by cell proliferation assays using mouse osteoblast cells (MC3T3‐E1). It was found that the plasma‐treated PCL NFMs gave a higher proliferation rate and improved cell adhesion properties as compared with the untreated controls. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2013.
Processing of degradable ulvan 3D porous structures for biomedical applications
Authors: Alves Anabela , Sousa Rui A. , Reis Rui L. 
Published: September 2012

AbstractThe interest in ulvan within a biomedical framework increases as the knowledge of this polysaccharide evolves. Ulvan has been recently proposed as a potential biomaterial, and structures based on this polysaccharide are now being studied for different biomedical applications. In this work, a novel porous structure based on cross‐linked ulvan was designed and characterized. Its mechanical performance, water‐uptake ability and weight loss were assessed, morphology analyzed through scanning electron microscopy, and morphometric parameters quantified by microcomputed tomography. Cell viability and cell proliferation were evaluated in order to estimate the cytotoxicity of these structures and respective degradation products. Produced ulvan structures revealed remarkable ability to uptake water (up to ∼ 2000% of its initial dry weight) and are characterized by a highly porous and interconnected structure. Furthermore, these ulvan structures underwent nontoxic degradation, and cells remained viable through the time of culture. These results position ulvan structures as prospective blocks that can be further functionalized in order to acquire the desired stability and needed biological interactivity to be used as tissue‐engineered structures. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2013.
Global health initiatives of US otolaryngology residency programs: 2011 global health initiatives survey results
Authors: Volsky Peter G. , Sinacori John T. 
Published: September 2012

AbstractObjectives/Hypothesis:The objectives of this work were to quantify the involvement of US otolaryngology residency programs in global health endeavors, identify goals and services provided, and determine the participation of residents and fellows.Study Design:Cross‐sectional survey of US otolaryngology faculty.Methods:A 10‐point online questionnaire was distributed to 103 US otolaryngology residency program directors; all faculty involved in global health volunteerism were invited to participate.Results:Twenty‐nine global health initiatives were represented. Most of the 24 residency programs involved (66%) had organized global health offices at their institutions; only 4% actually cooperated with these offices. Most often, only one attending (55%) was involved at each institution. Residents/fellows participated 65% of the time. Abroad, US otolaryngologists worked with freestanding hospitals or clinics (24%), American nongovernmental organizations (17%), academic centers (14%), and remote locations (14%). Most (96%) provided specialty surgical services, but some provided primary care (28%) and general surgical services (14%); 72% trained foreign surgeons. Most respondents (79%) reported that the clinical work done abroad was substantial enough for Accreditation Council for Graduate Medical Education (ACGME) standards. Only one fifth of respondents knew the name of the nearest otolaryngology training institution. Humanitarian aid was the most prevalent goal (100%), followed by resident/fellow exchange (45%) and faculty exchange (21%).Conclusions:At least a quarter of US otolaryngology residency programs engage in global health volunteerism. Most do not utilize institutional global health resources and are unaware of otolaryngology training programs abroad. There may be a role for global health education within the ACGME competency of systems‐based practice. Laryngoscope, 2012
Bilateral sinonasal polyposis in a patient with unilateral choanal atresia
Authors: Lee Brian , Patel Nimish , Ferguson Berrylin J. 
Published: September 2012

AbstractSinonasal polyposis is a disorder of hyperplastic mucosal inflammation that subsequently leads to the development of smooth, pale, non‐neoplastic masses. The theories on its pathogenesis are diverse and remain debated within the medical community. A distinct, widely accepted, and unifying theory is absent, and probably unrealistic given the varying possible causes. The case reported here, which demonstrates nasal polyp formation within an atretic nasal cavity, suggests that nasal airflow or aerodynamics may have little to no effect on its etiology. It also seems to provide evidence that at least in some individuals nasal polyps appear to be due to an inflammatory disorder independent of inhalant allergen challenge. Laryngoscope, 2013
Scalp as split thickness skin graft donor site for congenital atresia repair
Authors: Goldsztein Hernan , Ort Stuart , Roberson Joseph B. , Reinisch John 
Published: September 2012

AbstractObjective:Describe the use of the scalp as a donor site for split thickness skin grafts in otologic surgery.Materials and Methods:Review of the literature with detailed description of surgical technique and authors' experience.Results:One hundred and forty‐ four scalp split thickness skin grafts were obtained between 2007 and 2011. No significant complications were observed with optimal cosmetic results.Conclusions:The scalp is a viable option as a split thickness skin graft donor site for otologic and other head and neck surgery. Advantages include improved cosmetic results at the donor site, quick healing with low complication rates, and easy accessibility in the operative field. Laryngoscope, 2012