bluuebunny/crossref_metadata_2025_split huggingface dataset:
Superantigens and Chronic Rhinosinusitis II: Analysis of T-Cell Receptor Vβ Domains in Nasal Polyps
Authors: Conley David B. , Tripathi Anju , Seiberling Kristin A. , Suh Lydia A. , Harris Kathleen E. , Paniagua Mary C. , Grammer Leslie C. , Kern Robert C. 
Published: August 2006

Background The superantigen (SAg) hypothesis of chronic rhinosinusitis (CRS) suggests that toxins within the nose stimulate massive oligoclonal expansion of T-cell populations with subsequent eosinophil recruitment and tissue inflammation. SAgs are capable of activating 1 × 104 more lymphocytes than conventional antigens by binding specific Vβ-domains of the T-cell receptor (TCR). The net effect is skewing from the normal Vβ-profile by oligoclonal expansion of specific domains. This study will assess polyp tissue for evidence of an SAg response in CRS with nasal polyps (CRSwNP). Methods This study consists of a prospective analysis of 18 CRSwNP subjects undergoing sinus surgery. Flow cytometry was used to analyze the distribution of 24 specific TCR Vβ-domains in lymphocytes from polyp tissue and blood. Evidence of oligoclonal expansion was tabulated for each specimen and defined as mean normative percentage + 2 SD. Results Eighteen of 18 CRSwNP subjects showed expansion of polyp lymphocytes expressing TCRs with specific Vβ-domains. The average number of Vβ-clones per CRSwNP subject was seven in polyp lymphocytes but only two in blood lymphocytes. Conclusion The current results indicate that polyp lymphocytes exhibit significant oligoclonal expansion of specific Vβ-domains. These data are considered diagnostic of a SAg effect. The corresponding blood profile is much less, suggesting that the nose is the primary source of stimulus. Although the trigger(s) for this expansion are unknown, these data are consistent with the hypothesis that staphylococcal toxins are central to the development of CRSwNP.
Nasal Airway Measurements in Children Treated by Rapid Maxillary Expansion
Authors: Compadretti Giacomo Ceroni , Tasca Ignazio , Bonetti Giulio Alessandri 
Published: August 2006

Background Rapid maxillary expansion is an orthodontic procedure that is commonly used to widen the maxilla. It is generally admitted that this technique is effective to correct palate narrowing, whereas there has not been agreement on the effect of this procedure in nasal parameters. The availability of a reliable and objective technique to assess the geometry of nasal cavities, such as acoustic rhinometry, stimulated the present investigation. Methods Twenty-seven children, undergoing rapid maxillary expansion, were evaluated by rhinomanometry and acoustic rhinometry. Postero-anterior radiographs were taken in 15 patients for cephalometric measurements. Examinations were performed before expansion treatment and after 12 month follow-up and compared to the measurements obtained from an untreated control group. Results With regard to rhinomanometry, we recorded a significant reduction in nasal airway resistance (NAR) after the orthodontic procedure only in decongestion. Using acoustic rhinometry, we found a significant increase in total minimum cross-sectional areas (TMCA) and total nasal volume (TNV) after the expansion both in basal and decongested conditions. Also, nasal cavity width and interzygomatic distance had a significant mean increase after the treatment. Comparison of measures between the control group and the treated group showed that the increase in TMCA and TNV, as well as the decrease in NAR, were significantly greater in the treated group in both basal and decongested conditions. Conclusion We demonstrated that rapid maxillary expansion is an effective procedure in widening nasal cavities with respect to an untreated control group and that the reported improvement in nasal breathing after palatal expansion, is a consequence of an increase in nasal size.
Studies on the Effects of Ice Collars on Nasal Blood Volume using Optical Rhinometry
Authors: Scheibe Mandy , Wüstenberg Eike G. , Hüttenbrink Karl-B. , Zahnert Thomas , Hummel Thomas 
Published: August 2006

Background The possible benefit of ice collars for treatment of nosebleed is controversial. The aim of this study was to investigate changes of nasal blood volume before and after application of ice collars to the neck. Nasal blood volume was investigated using optical rhinometry. Methods A total of 15 young, healthy volunteers participated. After ice collars were placed on the neck area of the subjects, changes in the blood volume of the nose were measured by means of optical rhinometry for the whole nose, but also regionally at the nasal septum (Kiesselbach's area). After baseline measurements over 1 minute, the ice collar was applied. Optical rhinometric measurements were performed continuously. Results Although the ice collar showed no effect on the blood volume of the whole nose, there was a significant decrease in blood volume (p < 0.01) at the septum. Conclusion Application of ice collars to the neck area of the subjects is followed by a decrease in blood volume of Kiesselbach's area, which may provide the basis for the clinical observation that ice collars are helpful in the treatment of nosebleeds.
A Prospective Randomized Blinded Cross-Over Trial Using Nasal Drops in Patients with Nasal Polyposis: An Evaluation of Effectiveness and Comfort Level of Two Head Positions
Authors: Raghavan Ullas , Jones Nicholas S. 
Published: August 2006

Background The aim of this study was to compare the efficacy and the degree of discomfort caused by the Mygind's (supine and head extended) position and the lying on the side head down (LSHD) position used for instilling nasal drops. We performed a prospective randomized blinded cross-over trial. Methods Twenty-three patients with nasal polyps were recruited and were given Betnesol nasal drops for 6 weeks after assessing their peak nasal inspiratory flow rate and grading the polyps. The assessor was blinded to the position used by the patient that was selected randomly. The patients were reviewed after 6 weeks when both their flow rates and their polyp grades were reassessed. They were given a visual analog chart to record the ease by which drops could be instilled and any discomfort caused by the position. After a 2-week washout period the patients were treated for another 6 weeks with the same drops using the other head position. Results Twenty-one patients completed the study. The LSHD and Mygind's positions were equally effective in controlling the nasal polypi. Mygind's position was easier to instill drops in the nose although LSHD position caused less discomfort for the patient. The nasal peak inspiratory flow increased linearly as the polyp size decreased. In 86 and 90% of the patients the nasal obstruction and nasal discharge, respectively, were well controlled. Conclusion The drops were efficacious in both head positions. The LSHD position caused the least discomfort, although patients found Mygind's position easier to instill drops. Steroid nasal drops are an effective way to manage patients with nasal polyposis.
Treatment of Epistaxis in Hereditary Hemorrhagic Telangiectasia Patients by Argon Plasma Coagulation with Local Anesthesia
Authors: Pagella Fabio , Semino Lucia , Olivieri Carla , Corno Sabrina , Dore Roberto , Draghi Ferdinando , Lanzarini Luca , Vespro Valentina , Buscarini Elisabetta , Danesino Cesare 
Published: August 2006

Background Recurrent epistaxis is the most common manifestation of hereditary hemorrhagic telangiectasia (HHT). The aim of this study was to determine the role and efficacy of argon plasma coagulation (APC) in the management of epistaxis caused by HHT. Methods From 1997 to 2004, 43 patients with diagnosed HHT were treated for recurrent epistaxis with APC in our department. Results Thirty-six patients reported substantial reduction of bleeding after treatment. Of the 18 patients who previously needed blood transfusions, 13 reported substantial reduction of bleeding after treatment and no blood transfusions were necessary. Conclusion APC allows a control of epistaxis in HHT patients and guarantees a long time free from blood transfusions. This treatment modality can be performed with local anesthesia, is not invasive, is well tolerated, is inexpensive, and can be used as a first step even in patients who need to undergo several blood transfusions for their epistaxis.
Periorbita: Computed Tomography and Magnetic Resonance Imaging Findings
Authors: Kim Hak Jin , Lee Tae Hong , Lee Hyun-Sun , Cho Kyu-Sup , Roh Hwan-Jung 
Published: August 2006

Purpose The periorbita has been regarded as the critical structure in decision of exenteration in the patients with paranasal (PNS) malignancies. The purpose of this study is to present the CT and MRI findings of the periorbita with PNS malignancies. Materials and Methods Ten patients with PNS cancers were chosen for this study. PNS CT and MRI scans were performed on all patients. The imaging findings were reviewed retrospectively by consensus of two neuroradiologists. Assessment of the defect of the orbital bone and invasion of the orbital fat was made by CT and MRI. The signal intensity (SI), thickness, enhancement, and correlation with the orbital bone of the periorbita were analyzed on MRI. The intraoperative and pathologic reports were used as the gold standard for orbital invasion. Results In patients with bone defects, it was impossible to differentiate the periorbita from the mass on CT. The periorbita showed hypointensity on T2-weighted images compared with the SI of mass. On Gd-enhanced T1-weighted images, the periorbita showed less enhancement than the mass in nine patients. Six patients showed two hypointense layers (the outer bony wall and the inner periorbita) between the mass and orbital fat on T2-weighted images. The thickness of the periorbita was 0.79–1.4 millimeter. Orbital invasion was more conspicuous on T2-weighted coronal images than on the CT images. Conclusions MRI was more conspicuous for detecting orbital invasion than CT. The mass beyond the thickened periorbita on T2-weighted images was considered to be a positive finding of orbital invasion.
Nasal Airflow during Respiratory Cycle
Authors: Chung Seung-Kyu , Son Young Rak , Shin Seok Jae , Kim Sung-Kyun 
Published: August 2006

Background Knowledge on the airflow patterns in the nasal cavity is essential to understanding the function of the nasal cavity. This study has attempted to observe the breath cycle of nasal airflow during respiration at rest. Methods We constructed a nasal cavity model by rapid prototyping using 1.25-mm-thick CT data and devised a piston pump driven by a cam, to simulate respiration at rest. The airflow was evaluated with particle image velocimetry and visualized in coronal reconstructed images. Results During the inspiration, a maximal velocity was observed at the valve area and the main stream occurred in the middle and superior airways. During the expiration, main stream was noted in the middle airway and was slow compared with the flow during inspiration. Vortexes were observed between inspiration and expiration. Conclusion This result widens our knowledge of nasal airflow and this technique will allow a more physiological understanding of nasal operations.
Immunolocalization of Surfactant Protein A and D in Sinonasal Mucosa
Authors: Woodworth Bradford A. , Lathers Deanne , Neal Jeffery G. , Skinner Margaret , Richardson Mary , Young M. Rita , Schlosser Rodney J. 
Published: August 2006

Background Surfactant-associated proteins (SP) A and D are in the family of collectin proteins that play an integral part in the innate defense system. SP-A and SP-D expression and function are altered in a variety of inflammatory and infectious diseases of the lungs, such as asthma, allergies, and cystic fibrosis. Our prior studies are the first to identify the presence of these proteins in the human sinonasal cavity. The objective of this study was to immunolocalize SP-A and SP-D in human sinonasal tissue. Methods Sinonasal mucosal biopsies were performed in patients with various forms of chronic hyperplastic rhinosinusitis with nasal polyposis and nondiseased mucosa from patients undergoing transsphenoidal hypophysectomy. (n = 10) Immunolocalization of surfactant proteins was performed with antibodies to SP-A and SP-D using immunoperoxidase staining technique. Isotype-negative controls were performed on all specimens. Results Analyses of mucosal biopsy specimens from human sinonasal tissue reveals staining within respiratory and intermediate (metaplastic)-type surface epithelium. In addition, staining was intense in the submucosal ductal epithelium of the seromucinous glands. These properties appear to be consistent regardless of disease state and location within the sinuses. Conclusion This is the first study to immunolocalize SP-A and SP-D in sinonasal human mucosa. These are secreted proteins that are intricately involved in innate immunity in the lungs. Their secretion in the upper airway indicates that future studies may allow manipulation of these proteins and development of novel treatments for sinonasal pathology.
Molecular Profile of the Antrochoanal Polyp: Up-Regulation of Basic Fibroblast Growth Factor and Transforming Growth Factor β in Maxillary Sinus Mucosa
Authors: Mahfouz Magdy Elsayed , Elsheikh Mohamed Nasser , Ghoname Nagla Fawzy 
Published: August 2006

Background Various pathogenetic mechanisms have been proposed to explain the development of antrochoanal polyps (ACPs); however, the cause is still largely unknown. The aim of this study was to characterize the expression and the potential role of a battery of molecular markers in the development of ACPs. A prospective controlled study of a case series was performed. Methods Tissue samples of maxillary sinus mucosa were obtained from 14 patients with ACPs, 17 patients with chronic nonpolypoid maxillary sinusitis, and 4 patients with normal maxillary sinus mucosa; RNAs were extracted from the sinus mucosa, and semiquantitative reverse transcription–polymerase chain reaction was performed for basic fibroblast growth factor, transforming growth factor β, and mucin genes (MUC), MUC5AC, MUC5B, and MUC8, to investigate their expression. Results The expression of basic fibroblast growth factor and transforming growth factor β was significantly higher in ACPs than in chronic rhinosinusitis and healthy mucosa. Meanwhile, the levels of expression of MUC genes were higher in ACPs and chronic rhinosinusitis compared with healthy mucosa. Conclusion These findings suggest that ACPs may represent an inflammatory reaction caused by overproduction of tissue-derived growth factors in an inductive environment.
Ba0.5Sr0.5Co0.8Fe0.2O3‐δ ceramic hollow‐fiber membranes for oxygen permeation
Authors: Liu S. , Tan X. , Shao Z. , Diniz da Costa J. C. 
Published: August 2006

AbstractSelf‐supported asymmetric hollow‐fiber membranes of mixed oxygen‐ionic and electronic conducting perovskite Ba0.5Sr0.5Co0.8Fe0.2O3‐δ (BSCF) were prepared by a combined phase‐inversion and sintering technique. The starting inorganic powder was synthesized by combined EDTA–citrate complexing process followed by thermal treatment at 600°C. The powder was dispersed in a polymer solution and then extruded into hollow‐fiber precursors through a spinneret. The fiber precursors were sintered at elevated temperatures to form gastight membranes, which were characterized by SEM and gas permeation tests. Performance of the hollow fibers in air separation was both experimentally and theoretically studied at various conditions. The results reveal that the oxygen permeation process was controlled by the slow oxygen surface exchange kinetics under the investigated conditions. The porous inner surface of the prepared perovskite hollow‐fiber membranes considerably favored the oxygen permeation. The maximum oxygen flux measured was 0.031 mol·m−2·s−1 at 950°C with the sweep gas flow rate of 0.522 mol·m−2·s−1. To improve the oxygen flux of BSCF perovskite membranes, future work should be focused on surface modification rather than reduction of the membrane thickness. © 2006 American Institute of Chemical Engineers AIChE J, 2006
An integrated methodology to evaluate permeability from measured microstructures
Authors: Selomulya C. , Tran T. M. , Jia X. , Williams R. A. 
Published: August 2006

AbstractMost existing data on solids dewatering behavior are based on macroscale phenomena and are often empirically based, whereas challenges still remain for fundamental understanding at a much smaller length scale. Prediction of microscale properties is now possible with enabling technologies such as X‐ray microtomography (XMT) for 3‐D imaging of solid structures and the Lattice–Boltzmann method (LBM) for calculating their permeability. Microstructural information with a spatial resolution of up to a few microns per pixel can be obtained through XMT and can be used directly by the LBM—a digital equivalent of the conventional CFD that is more adept at dealing with solid boundaries of complex geometry such as filter media—to calculate flow distribution through the porous structure. An example of this approach using glass beads is described here, from which the permeability of sediments containing this material can be predicted on the basis of a bench‐top test and the use of fluid flow simulations. The ability to derive performance information—such as fluid permeability from laboratory‐based measurements of microstructure coupled with appropriate microscale physical simulations—has considerable potentials. It is proposed that the method may be used to predict trends such as the filtration behavior of porous structures under different states of compression. This offers a significant benefit in assisting the formulation design of flocculated materials pertinent to a number of industrial sectors wishing to design optimal filtration or relevant operations. © 2006 American Institute of Chemical Engineers AIChE J, 2006
Who will you ask? An empirical study of interpersonal task information seeking
Authors: Xu Yunjie (Calvin) , Tan Bernard C.Y. , Yang Li 
Published: August 2006

AbstractInformation seeking behavior is an important form of human behavior. Past literature in information science and organizational studies has employed the cost‐benefit framework to analyze Seekers' information‐source choice decision. Conflicting findings have been discovered with regard to the importance of source quality and source accessibility in Seekers' choices. With a focus on interpersonal task information seeking, this study proposes a seeker‐source‐information need framework to understand the source choice decision. In this framework, task importance, as an attribute of information need, is introduced to moderate Seekers' cost‐benefit calculation. Our empirical study finds that in the context of interpersonal task information seeking, first, the least effort principle might not be adequate in explaining personal source choices; rather, a quality‐driven perspective is more adequate, and cost factors are of much less importance. Second, the seeker‐source relationship is not significant to source choices. Third, the nature of information need, especially task importance, can modify Seekers' source choice decisions.
Modeling successful performance in Web searching
Authors: Aula Anne , Nordhausen Klaus 
Published: August 2006

AbstractSeveral previous studies have measured differences in the information search success of novices and experts. However, the definitions of novices and experts have varied greatly between the studies, and so have the measures used for search success. Instead of dividing the searchers into different groups based on their expertise, we chose to model search success with task completion speed, TCS. Towards this goal, 22 participants performed three fact‐finding tasks and two broader tasks in an observational user study. In our model, there were two variables related to the Web experience of the participants. Other variables included, for example, the speed of query iteration, the length of the queries, the proportion of precise queries, and the speed of evaluating result documents. Our results showed that the variables related to Web experience had expected effects on TCS. The increase in the years of Web use was related to improvement in TCS in the broader tasks, whereas the less frequent Web use was related to a decrease in TCS in the fact‐finding tasks. Other variables having significant effects on TCS in either of the task types were the speed of composing queries, the average number of query terms per query, the proportion of precise queries, and the participants' own evaluation of their search skills. In addition to the statistical models, we present several qualitative findings of the participants' search strategies. These results give valuable insight into the successful strategies in Web search beyond the previous knowledge of the expert–novice differences.
Site‐Specific Labelling of Proteins with a Rigid Lanthanide‐Binding Tag
Authors: Su Xun‐Cheng , Huber Thomas , Dixon Nicholas E. , Otting Gottfried 
Published: August 2006

AbstractThis paper describes a generic method for the site‐specific attachment of lanthanide complexes to proteins through a disulfide bond. The method is demonstrated by the attachment of a lanthanide‐binding peptide tag to the single cysteine residue present in the N‐terminal DNA‐binding domain of the Escherichia coli arginine repressor. Complexes with Y3+, Tb3+, Dy3+, Ho3+, Er3+, Tm3+ and Yb3+ ions were formed and analysed by NMR spectroscopy. Large pseudocontact shifts and residual dipolar couplings were induced by the lanthanide‐binding tag in the protein NMR spectrum, a result indicating that the tag was rigidly attached to the protein. The axial components of the magnetic susceptibility anisotropy tensors determined for the different lanthanide ions were similarly but not identically oriented. A single tag with a single protein attachment site can provide different pseudocontact shifts from different magnetic susceptibility tensors and thus provide valuable nondegenerate long‐range structure information in the determination of 3D protein structures by NMR spectroscopy.
Paramagnetic Properties of the Halide‐Bound Derivatives of Oxidised Tyrosinase Investigated by 1H NMR Spectroscopy
Authors: Tepper Armand W. J. W. , Bubacco Luigi , Canters Gerard W. 
Published: August 2006

AbstractThe 1H NMR relaxation characteristics of the histidines in the oxidised type‐3 copper site of tyrosinase (Tymet) from the bacterium Streptomyces antibioticus in the halide‐bound forms (TymetX with X = F−, Cl−, Br−) have been determined and analysed. The 1H NMR spectra of the TymetX species display remarkably sharp, well‐resolved, paramagnetically shifted 1H signals, which originate from the protons of the six His residues coordinated to the two CuII ions in the type‐3 centre. From the temperature‐dependence of the 1H paramagnetic shifts the following values for the exchange‐coupling parameter −2J were determined: 260 (TymetF), 200 (TymetCl) and 162 cm−1 (TymetBr). The 1H T1 relaxation is dipolar in origin and correlates with the CuH distances. Electronic relaxation times τS derived from the 1H T1 data amount to about 10−11 s and follow the order TymetF>TymetCl>TymetBr. They are two orders of magnitude shorter than the τS values reported for mononuclear copper systems, in accordance with the sharpness of the 1H signals. The results corroborate the Cu2 bridging mode of the halide ions. On the basis of the measured hyperfine interaction constants for the ligand histidine nuclei, it is concluded that 70–80 % of the spin density in the excited triplet state resides on the two copper ions and the bridging atoms.