bluuebunny/crossref_metadata_2025 huggingface dataset:
Prognostic Impact of Primary Tumor Volume in Patients With Nasopharyngeal Carcinoma Treated by Definitive Radiation Therapy
Authors: Shen Chunying , Lu Jiade Jay , Gu Yajia , Zhu Guopei , Hu Chaosu , He Shaoqin
Published: February 2009

Objectives/Hypothesis: Tumor burden has been confirmed as one of the important indicators in disease control after treatment for various types of malignancies. This report aims to document the value of the primary tumor volume of nasopharyngeal carcinoma [gross tumor volume of the primary site (GTV‐P)] in predicting the treatment outcome after high‐dose definitive radiation therapy.

Study Design: A total of 154 patients with nasopharyngeal carcinoma were prospectively treated with accelerated hyperfractionated radiotherapy alone to a total dose of 78 Gy/60 fractions/6 weeks (biological effective dose = 88.2 Gy).

Methods: Patients were assessed for local control, disease‐free survival and distant failure free survival. The GTV‐P was calculated by summation of area technique after delineation of the primary tumor contours on computed tomography images.

Results: The median GTV‐P was 14.5 mL for T1, 23.3 mL for T2, 35.8 mL for T3, and 50.9 mL for T4 diseases (P < .05). With a median follow‐up of 61 months, the 5‐year local failure‐free rate, disease‐free survival and distant failure‐free survival rates were 89.4% versus 48.9% (P = .002), 56.6% versus 0% (P = .001), and 66.9% versus 16.5% (P = .0001), respectively, for patients whose GTV‐P were ≤60 mL and >60 mL. Multivariate analysis revealed that GTV‐P is an independent prognostic factorfor local control (hazard ratio = 3.568, P = .035). There fore, the GTV‐P was significantly associated with the treatment outcome after high‐dose radiation delivered in accelerated hyperfractionated schedule for nasopharyngeal cancer patients.

Conclusions: Tumor volume is a reliable indicator for supplementing the T classification of the Tumor, Node, Metastasis staging system for predicting local control after definite radiation therapy.
Laser Disruption of Biofilm
Authors: Krespi Yosef P. , Stoodley Paul , Hall‐Stoodley Luanne
Published: February 2009

Objectives/Hypothesis: To demonstrate the capability of a fiber‐based Q‐switched Nd:YAG laser (ARCLaser, Nuremberg, Germany and Valam, Orangeburg, NY) to disrupt biofilm.

Study Design: Biofilms were grown in broth for 72 hours prior to the experiment. A clinical otorrhea isolate from Pseudomonas aeruginosa was used. Biofilms were placed in MatTek culture plates, on stainless steel screws, tympanostomy tubes, and polyethylene terephthalate (PET) sutures.

Methods: Culture plates, stainless steel screws, tympanostomy tubes, and PET sutures were used for the laser disruption of biofilm experiments. Q‐switched Nd:YAG laser pulses were delivered on biofilms using shockwave probes originally designed for cataract surgery. The thin laser fiber tip was targeted against a titanium target, creating the production of plasma and resulting in a shockwave effect.

Results: Biofilm areas were imaged before, during, and after laser application using a confocal microscope. The biofilm was imaged growing on the glass/plastic step of the plates, in the grooves of the threads of the screws, over the tympanostomy tube, and on the PET suture. During laser treatment, a time‐lapse function was used to capture the results. As a result of laser‐generated shockwaves, the biofilm was initially seen to oscillate and eventually break off with individual pulses. Large and small pieces of biofilm were totally and instantly removed from the surface to which they were attached in a matter of a few seconds.

Conclusions: We were able to effectively disrupt Pseudomonas aeruginosa biofilms in vitro using a miniature Q‐switched Nd:YAG laser, thin fibers, and special probes that generated plasma formation and a resulting shockwave effect. This laser technology has the ability to generate a powerful stress wave sufficient to disrupt biofilm without any ill effect to the underlying host structure.
Sinonasal Outcomes After Endoscopic Sinus Surgery in Asthmatic Patients With Nasal Polyps: A Difference Between Aspirin‐Tolerant and Aspirin‐Induced Asthma?
Authors: Awad Osama G. , Lee John H. , Fasano Mary Beth , Graham Scott M.
Published: February 2009

Objectives/Hypothesis: Aspirin‐sensitivity, asthma, and nasal polyposis (NP) comprise the clinical entity of Samter's triad. The aim of this study is to report the sinonasal outcomes of endoscopic sinus surgery (ESS) in treating NP in asthmatic patients, comparing aspirin‐induced asthmatic (AIA) patients with aspirin‐tolerant asthmatics (ATA).

Study Design: Retrospective chart review.

Methods: The records of 66 patients with NP and asthma were retrospectively reviewed. Forty‐one AIA patients were compared with 25 ATA patients. For each patient, a Lund‐Mackay computed tomography (CT) score of the preoperative scans and the available postoperative CT scans in a period of 18 months were calculated and used as primary endpoint. Sinonasal improvement assessed by patients and reported with a symptoms scale was used as the secondary endpoint for the comparison immediately before surgery and 6 months and 12 months following ESS.

Results: Preoperative CT scores in AIA patients compared with ATA patients were significantly higher 19 (standard deviation, 4.82) vs. 14 (standard deviation, 6.8), respectively (P = .006). This difference was sustained for the available postoperative CT scans (P < .0001). During the period of 18 months follow‐up, 63.4% of AIA patients vs. 96% of ATA patients had CT improvement with a statistically significant difference between the two groups (P = .003). At 6 months following ESS, 63.4% of AIA patients vs. 56% of ATA patients had symptomatic improvement. At 12 months, 68.3% of AIA patients vs. 60% of ATA patients had symptomatic improvement, with no significant difference between the two groups.

Conclusion: AIA patients had more extensive sinonasal disease than ATA patients. Both groups showed statistically significant improvement in sinonasal outcomes after ESS. The difference between the two groups was statistically significant for patients' CT improvement with worse CT scores being seen in AIA patients.
Protective Effect of Immunosuppression on Granulation Tissue Formation in Metallic Airway Stents
Authors: Shlomi Dekel , Peled Nir , Shitrit David , Bendayan Daniele , Amital Anat , Kramer Mordechai R.
Published: February 2009

Objectives/Hypothesis: The use of self‐expanding metallic airway stents has been extended in recent years in inoperable patients with malignant and benign airway diseases. The risk of granulation tissue formation in the stent is a major concern. The objective of the present study was to determine whether immunosuppression modulates granulation tissue formation in airway stents, as seen in coronary stents.

Study Design: The study included 19 patients with benign airway obstructions and 11 recipients of lung transplants with anastomotic obstructions who were receiving immunosuppression therapy.

Methods: The degree of in‐stent granulation tissue formation was evaluated (score range, 0–3) every 3 months for 2 years.

Results: Granulation tissue formation was significantly lower in the transplant recipients than in the nontransplant patients at 3 months (score 0.7 vs. 1.6, P = .031), 15 months (score 0 vs. 1.1, P = .026), and 18 months (score 0 vs. 1.8, P = .020). During the 2 years of follow‐up, the transplant recipients underwent significantly fewer laser resections and brachytherapy treatments for in‐stent granulation.

Conclusions: The immunosuppression given to lung transplant recipients may have an inhibitory effect on granulation tissue formation in metallic airway stents. Further studies are needed to evaluate the effect of systemic therapy or coated stents with drugs such as sirolimus.
Nonverbal Cognitive Abilities and Auditory Performance in Children Fitted With Auditory Brainstem Implants: Preliminary Report
Authors: Colletti Liliana , Zoccante Leonardo
Published: February 2009

Objectives/Hypothesis: Auditory brainstem implants (ABIs) can provide excellent open set speech recognition in adults without auditory tumors. These favorable results prompted us to extend ABI indications to children with profound hearing loss (HL) who are not candidates for a cochlear implant (CI). This article reports on the auditory performance and cognitive development measured in children with ABIs.

Study Design: This study quantifies the development of auditory perceptual and nonverbal cognitive abilities of children with profound HL undergoing ABI. From 2000 to 2006, 17 children aged 14 months to 16 years received an ABI for different tumor and nontumor diseases in our department in Verona, and nine children were operated in other countries. Six of the children had been previously fitted elsewhere with a CI with no auditory results. Fourteen children had multiple associated psychomotor handicaps.

Methods: The retrosigmoid approach was used in all children. Intraoperative and postoperative electrically evoked auditory brainstem responses were performed in all children. Perceptual auditory abilities were evaluated with the Evaluation of Auditory Responses to Speech battery and the Category of Auditory Performance test. Cognitive evaluation was performed on 10 children using the Leiter International Performance Scale—Revised test.

Results: All children consistently use their devices for 8 h/d at average and have environmental sound awareness and utterance of words and simple sentences. Their category of auditory performance test scores increased significantly with ABI use. Scores on two of the four subtests considered for cognitive evaluation in this study increased significantly (P < .05) during the first year of ABI use. Postimplant cognitive outcomes were positively related to the auditory results.

Conclusions: The present investigation clearly indicates that children who are not candidates for CI fitted with ABI obtain significant development of their hearing ability and a significant improvement in some cognitive parameters. The outcomes of the present study suggest that children with cochlear or cochlear nerve abnormalities with associated cognitive deficits should not be excluded from ABI implantation.
Characterization of Laryngeal Muscle Stem Cell Survival and Proliferation
Authors: Walz Patrick C. , Hiatt Kelly K. , Naidu Moumita , Halum Stacey L.
Published: February 2009

Objectives/Hypothesis: Laryngeal muscle and skeletal muscle stem cells (MSC) have been shown to differ in physiological basal activity and responsiveness to stimuli. Given these differences, it is the purpose of this investigation to characterize the in vitro proliferation and survival of laryngeal and skeletal MSC to determine whether intrinsic differences exist that may account for differences noted in vivo.

Study Design: Basic science experiment utilizing rat MSC.

Methods: Cultures of both laryngeal and skeletal MSC were harvested and equal numbers from both groups were expanded under similar conditions, quantifying cellular population to determine proliferation rate for each population. Increased proliferative potential was confirmed using Western blot analysis of extracellular signal‐regulated kinase phosphorylation. As per standard survival assay protocol, cultures were placed in serum‐deprived medium and cell survival was assessed by terminal uridine deoxynucleotidyl transferase‐mediated dUTP nick end labeling assay at 72 hours.

Results: Our results demonstrated increased proliferation of laryngeal MSC relative to the skeletal MSC when cultured under similar conditions. Western blot demonstrated increased activation of the proliferation pathway, extracellular signal‐regulated kinase, in the laryngeal group. There was no detectable difference in the MSC survival between the two groups.

Conclusions: Compared with skeletal MSC, laryngeal MSC demonstrate increased proliferation and regenerative capacity. This may explain some of the differences in physiological role and responses involved in each cell population's tissue of origin.
TNF‐α Drives Matrix Metalloproteinase‐9 in Squamous Oral Carcinogenesis
Authors: Hohberger Laurie , Wuertz Beverly R. K. , Xie Hongwei , Griffin Tim , Ondrey Frank
Published: February 2009

Objectives/Hypothesis: It is well known that invasion is a seminal event in the progression of oral and other head and neck carcinoma sites. We have previously demonstrated tumor necrosis factor (TNF)‐α and its dependent cytokines are upregulated in saliva during oral carcinogenesis. TNF‐dependent events stimulate nuclear factor (NF)‐κB and many NF‐κB‐dependent genes are associated with cancer progression.

Materials and Methods: In the present study, we examined NF‐κB stimulation of matrix metalloproteinase (MMP)‐9 in a precancerous keratinocyte cell line that models leukoplakia (Rhek cells). We stimulated Rhek cells with both TNF‐α and phorbol myristate acetate, known stimulants of NF‐κB. We then assayed MMP‐9 transcription and secretion by luciferase reporter genes, quantitative real‐time polymerase chain reaction, and fluorometric enzyme‐linked immunosorbent serologic assay.

Results: We discovered that the MMP‐9 promoter was significantly stimulated by phorbol myristate acetate and TNF‐α on luciferase reporter gene assays. Further, we uncovered that functional MMP‐9 promoter activation was accompanied by significant increases in MMP‐9 gene expression, as judged by quantitative real‐time polymerase chain reaction. Functional activation of the MMP‐9 protein was stimulated by TNF‐α and PMA on a fluorescent enzyme‐linked immunosorbent serologic assay. Finally, we searched our salivary proteomic database for increases in MMP‐9 and discovered it was the third most significant protein in salivas of oral cavity cancer patients over normal controls.

Conclusions: We conclude the milieu cytokine, TNF‐α, has the capacity to provide stimulation of events related to early invasion of oral cavity cancer, as judged by its ability to stimulate MMP‐9.
To POP or Not: Ossiculoplasty in Congenital Aural Atresia Surgery
Authors: Dobratz Eric J. , Rastogi Akhil , Jahrsdoerfer Robert A. , Kesser Bradley W.
Published: February 2009

Objectives/Hypothesis: To examine indications for ossiculoplasty (OP) in aural atresia surgery and to compare audiometric results and surgical revision rates between patients undergoing OP and those undergoing intact native chain reconstruction (INCR).

Study Design: Retrospective chart review.

Methods: Charts of patients undergoing surgery for congenital aural atresia were reviewed for demographic data, preoperative Jahrsdoerfer score, ossicular chain status, and audiometric data. Patients undergoing OP were compared with an equal number of age and Jahrsdoerfer grade‐matched patients who had an INCR. The preoperative and postoperative average air‐bone gap (ABG), speech reception thresholds (SRT), and rates of revision surgery were compared between the two groups.

Results: Nineteen patients (20 ears) underwent OP during aural atresia repair and were compared with 20 matched patients who had INCR. Mean age, Jahrsdoerfer score, preoperative ABG, and SRT were similar for both groups. Mean postoperative audiometric follow‐up was 33.1 months for the OP group and 20.4 months for the INC group (P = .24). Mean postoperative ABG was 33.8 dB HL for OP and 23.8 dB HL for INCR (P < .05). Mean improvement in ABG was 16.8 dB HL for OP and 29.9 dB HL for INCR (P < .001). Mean improvement in SRT was 24.6 dB HL for OP and 34.8 dB HL for INCR (P < .05). Nine ears (45%) in the OP group and four ears (20%) in the INCR group underwent revision surgery (P = .09).

Conclusions: Patients reconstructed with their own intact native chain during aural atresia surgery have better audiometric outcomes than those undergoing OP and are less likely to undergo revision surgery.
The Utility of Second‐Look Operation After Laser Microresection of Glottic Carcinoma Involving the Anterior Commissure
Authors: Roh Jong‐Lyel , Kim Dong‐Hyun , Park Chan Il
Published: February 2009

Objectives/Hypothesis: Transoral laser microsurgery for the treatment of glottic carcinoma with anterior commissure (A‐com) involvement is associated with a high rate of recurrence. We prospectively evaluated the outcomes of laser microsurgery and the efficacy of second‐look operation in these patients.

Study Design: Prospective evaluation.

Methods: Twenty‐seven patients with glottic carcinomas involving the A‐com underwent transoral laser microresection. Twenty‐five patients underwent second‐look operations 3 months after laser surgery.

Results: After transoral laser microresection, all patients achieved microscopic clear resection margins. Local recurrence was found in 7 of 27 patients (25.9%). Regional recurrence was found in two patients. Patients with recurrences underwent laser re‐resection or neck dissection; four received radiotherapy, two lost their larynxes, and three died of disease. At second‐look operation, early local recurrence was found in two patients, and anterior glottic webs and granulomas causing dysphonia were treated in 8 and 11 patients, respectively.

Conclusions: Laser microsurgery is an effective treatment modality in early glottic cancer with A‐com involvement but is still associated with a high rate of recurrence. Second‐look operation may help detect early local recurrence and treat postoperative airway or voice problems.
Follow‐up of Cochlear Implant Use in Patients Who Developed Bacterial Meningitis Following Cochlear Implantation
Authors: Mancini Patrizia , D'Elia Chiara , Bosco Ersilia , Seta Elio De , Panebianco Valeria , Vergari Valeria , Filipo Roberto
Published: February 2009

Objectives/Hypothesis: The present study is a long‐term follow‐up of speech perception outcomes and cochlear implant use in three cases of meningitis that occurred after cochlear implantation.

Study Design: Case series study.

Methods: Study was performed on three children implanted with different models of Clarion® devices, two of them with positioner. Recognition and comprehension were assessed via the Italian adaptation of GASP (TAP) test, and phonetically balanced bi‐syllabic words in open‐set. High resolution computed tomography scan acquisition was performed to obtain axial coronal and oblique multiplanar reconstructions of the cochlea.

Results: Two patients were affected by enlarged cochlear acqueduct and Mondini malformation the first carrying positioner. One patient had a normal cochlea, and the positioner could have been the main cause of bacterial spread. As a consequence of meningitis the child with normal cochlea and the other with enlarged vestibular acqueduct developed cochlear ossification, increased M‐level and worsening of hearing outcomes. The child with Mondini malformation developed facial nerve stimulation. Contralateral implantation was performed in the first two patients.

Conclusion: Bacterial meningitis occurring after cochlear implantation may induce cochlear ossification, facial nerve stimulation, and permanent or temporary loss of implant use. Planned follow‐up with high resolution computed tomography and evaluation of M‐levels could be useful prognostic tools in the management of these patients.
Cervical Tuberculosis: A Decision Tree for Protecting Healthcare Workers
Authors: Roberts Daniel S. , Dowdall Jayme R. , Winter Leslie , Sulis Carol A. , Grillone Gregory A. , Grundfast Kenneth M.
Published: February 2009

Objectives/Hypothesis: The clinical presentation of cervical tuberculosis (TB) is a unique challenge to the otolaryngologist. To minimize the risk of nosocomial transmission, otolaryngologists must suspect the diagnosis and be familiar with recommendations for TB prevention.

Study Design: Scientific review.

Methods: We review current literature and recent changes in TB prevention strategies including the Centers for Disease Control and Prevention “Guidelines for Preventing the Transmission of Mycobacterium tuberculosis in Health‐Care Settings, 2005.”

Results: Nosocomial transmission may occur from either unrecognized pulmonary disease or from aerosolization of tubercle bacilli during diagnostic procedures. History of prior TB infection, residence in a country where TB is endemic, close contact with a TB patient, or positive tuberculin skin test should raise suspicion of cervical TB. Physical examination findings may include painless, unilateral cervical lymphadenopathy. Children and human immunodeficiency virus infected patients present unique challenges, as these groups may have atypical presentations. When cervical TB is suspected, the provider should always screen for pulmonary and laryngeal disease. Fine needle aspiration with polymerase chain reaction or culture may accurately identify cervical TB. In rare cases, excisional biopsy may be required.

Conclusions: To facilitate interpretation and rapid diagnosis while minimizing risk to health care providers, we provide a decision tree based on new federal guidelines and the clinical experience of a team of infectious disease specialists and otolaryngologists.
The Role of Computed Tomography for Localization of Parathyroid Adenomas
Authors: Zald Philip B. , Hamilton Bronwyn E. , Larsen Michael L. , Cohen James I.
Published: February 2009

Objective/Hypothesis: The purpose of this study was to evaluate the use of computed tomography (CT) for localization of parathyroid adenomas (PA) when first‐line imaging is indeterminate.

Study Design: Retrospective case series.

Methods: A search of operating room and radiology records identified 223 surgical explorations for primary hyperparathyroidism. Adenoma locations on CT, ultrasound, and nuclear scintigraphy were correlated with an independent review of operative records.

Results: The presence of adenoma in the correct side and quadrant of the neck was predicted by CT in 89% and 77% of studies, respectively. When first‐line studies were indeterminate, the positive predictive value of CT for localization of PA to the correct side and quadrant of the neck was 87% and 69%, respectively.

Conclusions: When first‐line localization studies are indeterminate in patients with primary hyperparathyroidism, CT is a valuable, rapid, and widely available imaging modality that can be used to localize PA.
Efficacy of Sinonasal Simulator in Teaching Endoscopic Nasal Skills
Authors: Ossowski Kathryn L. , Rhee Diane C. , Rubinstein Elaine N. , Ferguson Berrylin J.
Published: February 2009

Objectives/Hypothesis: To develop a nasal model (NM) which accurately simulates human texture and anatomy and to study the effect of training with NM on performance of video rigid nasal endoscopy and video flexible laryngoscopy. At the conclusion of this presentation, the participants should be able to demonstrate that training with nasal endoscopic simulation enhances efficiency and may improve comfort to the patient.

Study Design: A randomized blinded control trial.

Methods: Twenty medical students without prior endoscopic experience, stratified by prior video game experience, were randomized to training or no training on NM. All participants viewed a 15‐minute video instruction on endoscopy. Students randomized to training then practiced on the NM for 15 minutes. All students were tested within 90 minutes of the initial instruction with a timed identification of structures on NM followed by a timed flexible laryngoscopy on a human volunteer who ranked comfort/discomfort on a visual analogue scale.

Results: The students in the training group had a significantly shorter procedure time on NM using rigid nasal endoscopy compared with untrained students (61 seconds vs. 104 seconds, P = .025). The trained students showed a trend, which did not reach statistical significance, toward faster flexible laryngoscopy on the model (23 seconds vs. 32 seconds, P = .085). The trained students had average lower discomfort scores (0.89 vs. 1.33) compared with untrained students, but this did not reach statistical significance.

Conclusions: Our NM accurately simulates human texture and anatomy and provides an opportunity for endoscopic training without concern of bloodborne pathogens and expense of cadavers. Further development of the NM is warranted to expand the training utility.
Time-delayed feedback in neurosystems
Authors: Schöll Eckehard , Hiller Gerald , Hövel Philipp , Dahlem Markus A
Published: February 2009

The influence of time delay in systems of two coupled excitable neurons is studied in the framework of the FitzHugh–Nagumo model. A time delay can occur in the coupling between neurons or in a self-feedback loop. The stochastic synchronization of instantaneously coupled neurons under the influence of white noise can be deliberately controlled by local time-delayed feedback. By appropriate choice of the delay time, synchronization can be either enhanced or suppressed. In delay-coupled neurons, antiphase oscillations can be induced for sufficiently large delay and coupling strength. The additional application of time-delayed self-feedback leads to complex scenarios of synchronized in-phase or antiphase oscillations, bursting patterns or amplitude death.
Neural field dynamics with local and global connectivity and time delay
Authors: Jirsa Viktor K
Published: February 2009

Spatially continuous networks with heterogeneous connections are ubiquitous in biological systems, in particular neural systems. To understand the mutual effects of locally homogeneous and globally heterogeneous connectivity, we investigate the stability of the rest-state activity of a neural field as a function of its connectivity. The variation of the connectivity is operationalized through manipulation of a heterogeneous two-point connection embedded into the otherwise homogeneous connectivity matrix, as well as by variation of connectivity strength and a finite transmission speed. The latter results in a time delay of communication among individual brain areas. We demonstrate that the local connectivity generates the well-known power-law behaviour of the electroencephalographic power spectrum with an exponent close to −2, whereas the global connections generate a more characteristic line spectrum. These spectral characteristics are routinely observed in large-scale topographies of the human brain.
Compensating time delays with neural predictions: are predictions sensory or motor?
Authors: Nijhawan Romi , Wu Si
Published: February 2009

Neural delays are a general property of computations carried out by neural circuits. Delays are a natural consequence of temporal summation and coding used by the nervous system to integrate information from multiple resources. For adaptive behaviour, however, these delays must be compensated. In order to sense and interact with moving objects, for example, the visual system must predict the future position of the object to compensate for delays. In this paper, we address two critical questions concerning the implementation of the compensation mechanisms in the brain, namely, where does compensation occur and how is it realized. We present evidence showing that compensation can happen in both the motor and sensory systems, and that compensation using ‘diagonal neural pathways’ is a suitable strategy for implementing compensation in the visual system. In this strategy, neural signals in the early stage of information processing are sent to the future cortical positions that correspond to the distance the object will travel in the period of transmission delay. We propose a computational model to elucidate this using the retinal visual information pathway.
Delay effects in the human sensory system during balancing
Authors: Stepan Gabor
Published: February 2009

Mechanical models of human self-balancing often use the Newtonian equations of inverted pendula. While these mathematical models are precise enough on the mechanical side, the ways humans balance themselves are still quite unexplored on the control side. Time delays in the sensory and motoric neural pathways give essential limitations to the stabilization of the human body as a multiple inverted pendulum. The sensory systems supporting each other provide the necessary signals for these control tasks; but the more complicated the system is, the larger delay is introduced. Human ageing as well as our actual physical and mental state affects the time delays in the neural system, and the mechanical structure of the human body also changes in a large range during our lives. The human balancing organ, the labyrinth, and the vision system essentially adapted to these relatively large time delays and parameter regions occurring during balancing. The analytical study of the simplified large-scale time-delayed models of balancing provides a Newtonian insight into the functioning of these organs that may also serve as a basis to support theories and hypotheses on balancing and vision.
Homology Modeling and Site-Directed Mutagenesis Reveal Catalytic Key Amino Acids of 3β-Hydroxysteroid-Dehydrogenase/C4-Decarboxylase from Arabidopsis
Authors: Rahier Alain , Bergdoll Marc , Génot Geneviève , Bouvier Florence , Camara Bilal
Published: February 2009

Sterols become functional only after removal of the two methyl groups at C4 by a membrane-bound multienzyme complex including a 3β-hydroxysteroid-dehydrogenase/C4-decarboxylase (3βHSD/D). We recently identified Arabidopsis (Arabidopsis thaliana) 3βHSD/D as a bifunctional short-chain dehydrogenase/reductase protein. We made use of three-dimensional homology modeling to identify key amino acids involved in 4α-carboxy-sterol and NAD binding and catalysis. Key amino acids were subjected to site-directed mutagenesis, and the mutated enzymes were expressed and assayed both in vivo and in vitro in an erg26 yeast strain defective in 3βHSD/D. We show that tyrosine-159 and lysine-163, which are oriented near the 3β-hydroxyl group of the substrate in the model, are essential for the 3βHSD/D activity, consistent with their involvement in the initial dehydrogenation step of the reaction. The essential arginine-326 residue is predicted to form a salt bridge with the 4α-carboxyl group of the substrate, suggesting its involvement both in substrate binding and in the decarboxylation step. The essential aspartic acid-39 residue is in close contact with the hydroxyl groups of the adenosine-ribose ring of NAD+, in good agreement with the strong preference of 3βHSD/D for NAD+. Data obtained with serine-133 mutants suggest close proximity between the serine-133 residue and the C4β domain of the bound sterol. Based on these data, we propose a tentative mechanism for 3βHSD/D activity. This study provides, to our knowledge, the first data on the three-dimensional molecular interactions of an enzyme of the postoxidosqualene cyclase sterol biosynthesis pathway with its substrate. The implications of our findings for studying the roles of C4-alkylated sterol precursors in plant development are discussed.
Nuclear Activity of ROXY1, a Glutaredoxin Interacting with TGA Factors, Is Required for Petal Development inArabidopsis thaliana
Authors: Li Shutian , Lauri Andrea , Ziemann Mark , Busch Andrea , Bhave Mrinal , Zachgo Sabine
Published: February 2009

Glutaredoxins (GRXs) have thus far been associated mainly with redox-regulated processes participating in stress responses. However, ROXY1, encoding a GRX, has recently been shown to regulate petal primorida initiation and further petal morphogenesis in Arabidopsis thaliana. ROXY1 belongs to a land plant-specific class of GRXs that has a CC-type active site motif, which deviates from ubiquitously occurring CPYC and CGFS GRXs. Expression studies of yellow fluorescent protein-ROXY1 fusion genes driven by the cauliflower mosaic virus 35S promoter reveal a nucleocytoplasmic distribution of ROXY1. We demonstrate that nuclear localization of ROXY1 is indispensable and thus crucial for its activity in flower development. Yeast two-hybrid screens identified TGA transcription factors as interacting proteins, which was confirmed by bimolecular fluorescence complementation experiments showing their nuclear interaction in planta. Overlapping expression patterns of ROXY1 and TGA genes during flower development demonstrate that ROXY1/TGA protein interactions can occur in vivo and support their biological relevance in petal development. Deletion analysis of ROXY1 demonstrates the importance of the C terminus for its functionality and for mediating ROXY1/TGA protein interactions. Phenotypic analysis of the roxy1-2 pan double mutant and an engineered chimeric repressor mutant from PERIANTHIA (PAN), a floral TGA gene, supports a dual role of ROXY1 in petal development. Together, our results show that the ROXY1 protein functions in the nucleus, likely by modifying PAN posttranslationally and thereby regulating its activity in petal primordia initiation. Additionally, ROXY1 affects later petal morphogenesis, probably by modulating other TGA factors that might act redundantly during differentiation of second whorl organs.
Bromido(η5-carboxycyclopentadienyl)dinitrosylchromium(0) and (η5-benzoylcyclopentadienyl)bromidodinitrosylchromium(0)
Authors: Wang Yu-Pin , Leu Hsien-Li , Lin Tso-Shen , Wang Yu , Lee Gene-Hsiang
Published: February 2009

In the structures of each of the title compounds, [CrBr(C6H5O2)(NO)2], (I), and [CrBr(C12H9O)(NO)2], (II), one of the nitrosyl groups is located at a site away from the exocyclic carbonyl C atom of the cyclopentadienyl (Cp) ring, with twist angles of 174.5 (3) and 172.5 (1)°. The observed orientation is surprising, since the NO group is expected to be situatedtransto an electron-rich C atom in the ring. The organic carbonyl plane is turned away from the Cp ring plane by 5.6 (8) and 15.2 (3)°in (I) and (II), respectively. The exocyclic C—C bond in (I) is bent out of the Cp ring plane towards the Cr atom by 2.8 (3)°, but is coplanar with the Cp ring in (II); the angle is 0.1 (1)°.
Two crystal forms of mesogenic bis(4′-cyanobiphenyl-4-yl) butanedioate
Authors: Hori Kayako , Kouno Naomi
Published: February 2009

The title compound, C30H20N2O4, exhibits a nematic phase in the wide temperature range between 498.5 and 538.6 K, in spite of the short linker moiety. Two crystal forms have been found. In both forms, the molecule is centrosymmetric. Form I has a planar biphenyl group, while form II has a twisted biphenyl group with a twist angle of 34.75 (6)°. The packing modes are also different. In form I the long molecular axes are tilted with respect to each other at about 30°, while in form II the long molecular axes have an almost parallel arrangement.
Polymorphism in iodotris(tri-p-tolylphosphine)silver(I)
Authors: Venter Gertruida J. S. , Roodt Andreas , Meijboom Reinout
Published: February 2009

The reaction of silver(I) iodide with tri(p-tolyl)phosphine in MeCN solution in 1:3 molar ratio yields a polymorph of the complex of the formula [AgI{P(4-MeC6H4)3}3], with the Ag atom in a distorted tetrahedral environment. A polymorphic structure of this complex (a) is compared with previously published crystal structures (b), determined at different temperatures. The two polymorphs are compared using r.m.s. overlay calculations as well as half-normal probability plots.
An aza-cyclophane stacked in racemic columnar assemblies: whole-molecule disorder in a two-dimensional solid solution
Authors: Zeller Matthias , Lutz Jr Marlon R. , Becker Daniel P.
Published: February 2009

The oxime derivative of [1.1.1]cyclophane cyclotriveratrylene (CTV) was ring expanded utilizing a Beckmann rearrangement to provide a ten-membered N-acetyl macrocyclic amide that crystallizes as a chloroform monosolvate in columnar assemblies manifesting an unusual disorder within the crystal. Columns made up of this structure consist of infinite columnar assemblies of alternating D and L enantiomers and therefore necessarily are made up of a racemate, yet the chiralities of individual molecules in adjacent columns are independent of one another, leading to the overall formation of a two-dimensional solid solution. The random arrangement of the columns within the structure leads to the emergence of a crystallographic mirror plane not reflected by the molecular symmetry, to a change of symmetry from Pna21 to Pnma and to whole-molecule disorder of the bowl-shaped molecules within the columns.
MARC data, the OPAC, and library professionals
Authors: Williams Jo
Published: February 2009

Purpose

The purpose of this paper is to show that knowledge of the Machine‐Readable Cataloguing (MARC) format is useful in all aspects of librarianship, not just for cataloguing, and how MARC knowledge can address indexing limitations of the online catalogue.

Design/methodology/approach

The paper employs examples and scenarios to show the usefulness of MARC knowledge among library professionals.

Findings

The paper finds that library professionals with an understanding of MARC also have an advantage in understanding how Online Public Access Catalogues (OPACs) work. With a knowledge of MARC, librarians can understand OPAC indexing limitations and develop ways to work around those limitations. An understanding of MARC bibliographic data across library specialities allows librarians to work interdependently to affect the functionality of the OPAC.

Originality/value

Editing/manipulating MARC data based on indexing limitations of the online catalogue can improve retrieval of library resources. Additionally, MARC knowledge and skills are transferable, even with the challenges of changing OPAC technology.
Chinese localisation of Evergreen: an open source integrated library system
Authors: Zou Qing , Liu Guoying
Published: February 2009

Purpose

The purpose of this paper is to investigate various issues related to Chinese language localisation in Evergreen, an open source integrated library system (ILS).

Design/methodology/approach

A Simplified Chinese version of Evergreen was implemented and tested and various issues such as encoding, indexing, searching, and sorting specifically associated with Simplified Chinese language were investigated.

Findings

The paper finds that Unicode eases a lot of ILS development problems. However, having another language version of an ILS does not simply require the translation from one language to another. Indexing, searching, sorting and other locale related issues should be tackled not only language by language, but locale by locale.

Practical implications

Most of the issues that have arisen during this project will be found with other ILS‐like systems.

Originality/value

This paper provides insights into issues of, and various solutions to, indexing, searching, and sorting in the Chinese language in an ILS. These issues and the solutions may be applicable to other digital library systems such as institutional repositories.
Modelling and implementation of catalogue cards using FreeMarker
Authors: Radjenovic Jelena , Milosavljevic Branko , Surla Dusan
Published: February 2009

Purpose

The purpose of this paper is to report on a study involving the specification (using Unified Modelling Language (UML) 2.0) of information requirements and implementation of the software components for generating catalogue cards. The implementation in a Java environment is developed using the FreeMarker software.

Design/methodology/approach

Object‐oriented methodology as well as CASE tools are used to design the software components. The system architecture makes the catalogue cards available from every segment of the library management system, and enables catalogue card updates without recompilation of the source code.

Findings

The outcome of the work is a software package, implemented in a Java environment, that generates and displays catalogue cards based on bibliographic records in the UNIMARC format, but it can be easily adapted for the other MARC formats.

Research limitations/implications

The package is limited to generating only catalogue cards based on MARC formats. In order to avoid this limitation it is possible to define specific metadata for catalogue card generation. In such a case, the catalogue cards could be generated from the metadata regardless of the bibliographic record format.

Practical implications

The software package is integrated into the BISIS library management software system used by 36 libraries including public, city, faculty and special libraries in Serbia.

Originality/value

The architecture of the software component can be used in different implementations of library management systems. It is only necessary to represent the bibliographic record data using the internal data structure of the FreeMarker software package.
A personalised information support system for searching portals and e‐resources
Authors: Sirisha B.S. , Jeevan V.K.J. , Raja Kumar R.V. , Goswami A.
Published: February 2009

Purpose

The purpose of this paper is to describe the development of a personalised information support system to help faculty members to search various portals and e‐resources without typing the search terms in different interfaces and to obtain results re‐ordered without human intervention.

Design/methodology/approach

After a careful survey of various tools and techniques available for computerised client‐centred information services, the study selected to apply web usage mining, proxy level data collection and a vector space retrieval model to develop the personalised information support for teaching and research in a higher education institution.

Findings

There are practical constraints in the implementation stage. There is considerable difficulty in getting real and correct user interests and mapping them effectively into the products and services offered by the library. Also the interests of users change continuously. If multiple users share the same PC, it is difficult to identify the user as there is no one‐to‐one mapping between user and IP address.

Research limitations/implications

The paper has not considered cases for all the faculty members due to time constraints. The results obtained from the system also need correlation with the sources actually used by the faculty to test its efficacy in a highly fluid research situation like higher academics.

Practical implications

A pragmatic client‐centred information support prototype described in this paper may find use in other institutions needing similar information support.

Originality/value

This paper demonstrates the pragmatic application of ICT for linking users and e‐resources in an academic library.
Towards an assessment of strategic credibility in academic libraries
Authors: Staines Gail
Published: February 2009

Purpose

The purpose of this original research is to gauge the level of academic libraries' strategic credibility by analyzing whether strategic planning goals align with annual reports.

Design/methodology/approach

A modified replication of a study by Jarvenpaa and Ives was used. A random sample of 28 ARL libraries was taken from ARL membership. Library directors were contacted for a copy of both a strategic plan and an annual report. A two‐way comparison was conducted between three groups using content analysis.

Findings

Analysis of strategic plans and annual reports revealed that the majority of the libraries in the study produced strategic plans. However, most libraries no longer produce annual reports. Canadian strategic plans were user‐centered, whereas US plans focused on “hot topics”. Themes emerged from the analysis of strategic plans including space planning, offsite storage, assessment, development, and personnel.

Research limitations/implications

Determining the level to which ARL libraries have strategic credibility is difficult to surmise, since the anticipated number of annual reports did not materialize. Further research is needed to compare what impact strategic plans and marketing strategies have on fundraising.

Practical implications

Several tactical methods libraries can implement in order to get the attention of potential donors and funding agencies to support projects and programs include the hiring of a library development officer, contracting with a marketing firm, and greatly improving the quality of communication to clientele.

Originality/value

The paper presents original research and is of value to academic library leaders who want to know about current trends in communicating strategic goals and objectives to their clientele.
On the future of library operations research
Authors: Warwick Jonathan
Published: February 2009

Purpose

This paper sets out to describe the development of problem‐structuring methods within operations research (OR) and to suggest that these might define new areas of collaborative activity between library management and OR modellers.

Design/methodology/approach

The paper identifies a requirement for the twenty‐first century academic library to be flexible, inclusive and responsive to rapidly changing environments. The use of problem‐structuring methods provides OR modellers with a methodological approach that can assist decision making under just these conditions, and so a management approach that places problem‐structuring methods firmly within library planning processes is suggested.

Findings

Since the rapid growth of library OR in the 1960s and 1970s (using primarily statistical and quantitative techniques) there has been a significant downturn in new applications and model developments within the last 20 years. This has coincided with a debate on the future of OR that has moved it away from the application of quantitative techniques, and the new paradigms evolving from that debate could stimulate a regeneration of interest in library OR.

Originality/value

The paper explores a possible future for library OR. The application of OR methods within libraries has undoubtedly had its successes and a wider appreciation of the potential use of problem‐structuring methods within library management could resolve many of the issues associated with planning library operations on the brink of the second decade of the twenty‐first century.