bluuebunny/crossref_metadata_2025_split huggingface dataset:
Intravenous Anesthesia Provides Optimal Surgical Conditions During Microscopic and Endoscopic Sinus Surgery
Authors: Eberhart Leopold H. J. , Folz Benedikt J. , Wulf Hinnerk , Geldner Götz 
Published: November 2003

AbstractObjectives/Hypothesis Controlled hypotension is used to improve surgical conditions during microscopic and endoscopic sinus surgery. New short‐acting anesthetics such as propofol and remifentanil allow exact control of intraoperative blood pressure and thus might be valuable tools to improve intraoperative conditions for the otorhinolaryngological surgeon. Intravenous anesthesia was compared with traditional balanced anesthesia by subjective assessment of surgical conditions made by two experienced otorhinolaryngological surgeons.Study Design Prospective, randomized, patient‐ and observer‐blinded study.Methods Ninety consecutive patients were randomly assigned to receive intravenous anesthesia with propofol 5 to 8 mg·kg−1·h−1 and remifentanil 10 to 30 μg·kg−1·h−1 or with isoflurane (0.4–1.0 vol%) and repetitive doses of 0.5 to 1 mg alfentanil. An injectable vasodilator was used in both groups to keep mean arterial pressure between 60 and 70 mm Hg (8–9.3 hecto‐pascal). The attending otorhinolaryngological surgeon was unaware of the type of anesthesia administered. Immediately after the operation the surgeons rated surgical conditions (bleeding from the surgical field) on a visual analogue scale (0–10 cm) and on a verbal rating scale.Results Blood pressure was not different between the two groups, but heart rate was lower in the intravenous anesthesia group (mean heart rate in the intravenous anesthesia group, 62 beats per min [95% confidence interval, 52–72]; mean heart rate in the balanced anesthesia group, 75 beats per min [95% confidence interval, 67–83]). Surgical conditions were rated to be significantly better (P <.0001) during anesthesia with propofol‐remifentanil (median rating: 2.8; 25th/75th per‐centile: 2.0/3.4) compared with isoflurane‐alfentanil (median rating: 4.9; 25th/75th percentile: 3.6/7.6).Conclusions Intravenous anesthesia using propofol‐remifentanil provides better surgical conditions compared with a traditional balanced anesthesia technique using isoflurane‐alfentanil. It is hypothesized that lower cardiac output caused by decreased heart rate during deep general anesthesia is responsible for this result.
The Effect of Nasal Polyp Epithelial Cells on Eosinophil Activation
Authors: Shin Seung‐Heon , Lee Sang‐Heon , Jeong Hyo‐Soon , Kita Hirohito 
Published: November 2003

AbstractObjectives/Hypothesis Eosinophil infiltration into an inflammatory site is a characteristic histological finding in patients with chronic rhinosinusitis and nasal polyps. Most of the eosinophils in chronic rhinosinusitis are activated in the nasal cavity, but the exact activation mechanism of eosinophils is unknown. The study was designed to investigate the effect of human nasal epithelial cells on the activation of eosinophils.Study Design Peripheral blood eosinophils were isolated from healthy volunteers and incubated in human nasal polyp epithelial cell conditioned media (HPECM). Superoxide production and eosinophil‐derived neurotoxin were measured to determine eosinophils activation. HPECMs were assayed by ELISAs for interleukin‐8 (IL‐8), granulocyte‐macrophage colony stimulating factor (GM‐CSF), eotaxin, and regulated on activation normal T expressed and secreted (RANTES). To identify the chemical mediators involved in the activation of eosinophils.Results HPECM (n = 7) contained 31.48 ng/mL interleukin‐8, 533.43 pg/mL GM‐CSF, 5.90 pg/mL eotaxin, and 11.06 pg/mL RANTES. Eosinophils were activated by HPECM and inhibited only by anti–GM‐CSF antibody, not by the other chemical mediators.Conclusion The results suggest that eosinophils in nasal secretions are activated by GM‐CSF, which is produced by nasal epithelial cells.
Vascularized Hemitracheal Autograft for Laryngotracheal Reconstruction: A New Surgical Technique Based on the Thyroid Gland as a Vascular Carrier
Authors: Zur Karen B. , Urken Mark L. 
Published: November 2003

AbstractBackground The management of extensive laryngotracheal stenosis has been a challenge confronting head and neck surgeons for over a century. The key to the successful restoration of a stable airway is providing a cartilaginous infrastructure to provide support to withstand both the negative and positive lumenal pressures produced during normal respiration and deglutition. We introduce a novel technique for restoration of such defects.Methods The blood supply to the thyroid gland by way of the inferior thyroid artery and the superior thyroid artery and vein are mobilized for transfer. One half to two thirds of the circumference of the adjacent tracheal rings are mobilized on the basis of the requirements of the stenotic segment. This mucochondrial composite tracheal flap is advanced superiorly to the ipsilateral “laryngeal” region where insetting of the cartilage and the mucosa is performed. Primary reconstruction or, more likely, a staged repair of the secondary tracheal defect is performed.Results Three case reports are presented. The patients were successfully decannulated postoperatively, continue to have an adequate voice, and are tolerating a diet (3–27 months postreconstruction).Conclusion A new surgical technique for reconstruction of benign laryngotracheal stenoses is introduced to restore phonatory capability and a stable airway. The composite thyroid‐tracheal graft based on the inferior and superior thyroid arterial pedicles allows a single‐staged, primary reconstruction of the hemilarynx with a well‐vascularized composite thyrotracheal flap that allows resurfacing as well as replacement of the infrastructure of the glottis and subglottis. This technique would be an excellent method to restore the cricoid ring following partial resection for primary cartilaginous tumors.
Subacute Hypoglossal Nerve Paresis with Internal Carotid Artery Dissection
Authors: Lindsay Fred W. , Mullin David , Keefe Michael A. 
Published: November 2003

AbstractObjectives To describe a case of an isolated hypoglossal nerve palsy in a patient with a spontaneous internal carotid artery dissection (ICAD). This condition is a well‐recognized cause of cerebral ischemic stroke in patients younger than 45 years of age. Isolated cranial nerve neuropathy is a rare presentation. More common manifestations include incomplete hemiparesis, hemicrania, Horner syndrome, cervical bruit, pulsatile tinnitus, and multiple cranial nerve palsies.Methods A comprehensive literature search (Ovid, MEDLINE) for the presentation, diagnostic evaluation, treatment, and outcome of patients with internal carotid artery dissection was performed.Results A 43‐year‐old man presented with a 3‐week history of mild dysarthria. There was no history of craniocervical trauma. The physical examination revealed an isolated left hypoglossal nerve paresis. Magnetic resonance imaging and angiography findings were consistent with a left skull base ICAD. The patient was successfully treated with anticoagulation therapy. The current rate of cranial nerve involvement is estimated at 10% of all ICADs. This is the second report of isolated hypoglossal nerve palsy without hemicrania in a case of atraumatic ICAD.Conclusions Patients with an ICAD infrequently present to the otolaryngologist because of its head and neck manifestations. It is crucial to recognize atypical findings and to perform an accurate and prompt diagnostic evaluation. The foundation of treatment is aggressive anticoagulation, with surgical or radiologic intervention reserved for cases demonstrating life‐threatening progression.
Molecular Disruption of the MRN(95) Complex Induces Radiation Sensitivity in Head and Neck Cancer
Authors: O'Malley Bert W. , Li Daqing , Carney James , Rhee Joung , Suntharalingam Mohan 
Published: November 2003

AbstractObjectives/Hypothesis The goal of the project was to develop a novel treatment strategy for head and neck cancer that induces radiation sensitivity. We hypothesized that the normal cellular DNA repair response in head and neck squamous cell carcinoma after radiation therapy can be blocked by a dominant negative disruption of the functioning MRN(95) protein complex. To test this hypothesis, we have developed a novel molecular therapy that inhibits the MRN(95) complex in tumor cells. Disruption the MRN(95) complex and thus DNA repair should result in enhanced tumor killing after classic external‐beam radiation therapy.Study Design Experiments with human head and neck squamous cell carcinoma cell lines in vitro were performed.Methods Recombinant adenovirus vectors carrying the genes for enhancing radiation were generated. Human head and neck squamous cell carcinoma cells were treated with recombinant adenovirus vectors carrying the mutated p95 gene (p95–300), which contains the C‐terminus 300 amino acids of the Nbs1(p95) protein. Tumor cells were also treated with adenovirus vector carrying full‐length p95 protein or DL312 control virus; then all cell lines were subjected to 2 Gy irradiation. Cell growth curves were determined through colorimetric tetrazolium salt assay.Results Both the Ad‐p95–300 and Ad‐p94‐his (full‐length wild‐type gene) demonstrated significant antitumor effect alone and in combination with radiation therapy compared with control samples. Cell cycle analysis demonstrated a shift toward the G2/M phase of the cell cycle. Analysis of telomerase activity demonstrated a significant decrease in telomerase activity after molecular therapy alone, and a greater decrease when combined with radiation therapy.Conclusion Adenovirus‐mediated mutant or full‐length p95 molecular therapy demonstrated efficacy for the treatment of head and neck squamous cell carcinoma in vitro. This novel molecular therapy strategy induced significant radiation sensitization, induced a relative G2/M arrest, and decreased telomerase activity, all of which enhance the benefit of radiation therapy.
Long‐term effect of adenotonsillectomy on quality of life in pediatric patients
Authors: Flanary Valerie A. 
Published: November 2003

AbstractHypothesis: Adenotonsillectomy improves general and disease‐specific quality of life for properly selected patients suffering for upper airway obstruction secondary to adenotonsillar hypertrophy (UAO) and obstructive sleep apnea (OSA). Study Design: Prospective, nonrandomized questionnaire. Specific Aims: To evaluate quality of life in patients with UAO and OSA using general quality of life instruments as well as disease‐specific instruments. The results will be compared both pre‐ and postoperatively. Methods: Fifty‐five patients aged 2 to 16 with the clinical diagnosis of UAO or OSA were recruited. The caregivers completed Children's Health Questionnaire Parent Form‐28 (CHQPF‐28) and OSA‐18 quality of life measures both pre‐ and postoperatively in the long and short term. Statistical analysis was performed using the unpaired Student t test, P value less than .05, and Spearman Rank coefficient. Results: CHQ‐PF28 scores were improved in the Physical Summary parameter in long‐term follow‐up. Psychosocial scores did not improve significantly. OSA‐18 scores showed improvement in both the short‐and long‐term scores. Physical findings and symptoms did not impact scores in any domain. Conclusions: Quality of life in children with OSA does improve after adenotonsillectomy. Disease‐specific clinometric instruments show improvement in domains affected by the disease process. However, instruments used to assess general quality of life may show physical improvement but not psychosocial.
Contralateral suppression of distortion‐product otoacoustic emissions declines with age: A comparison of findings in CBA mice with human listeners
Authors: Jacobson Michael , Kim Sunghee , Romney Joshua , Zhu Xiaoxia , Frisina Robert D. 
Published: November 2003

AbstractObjectives/Hypothesis: The auditory efferent system plays presumed roles in enhancing signals in noise, maintaining the cochlea for optimal acoustic signal processing, and may have a protective role in preserving auditory function in the face of ototoxic events. The objective of the study was to measure age‐related changes of the medial olivocochlear efferent system in mice by comparing distortion‐product otoacoustic emissions generated with and without contralateral white noise stimulation. Consistent with prior work, distortion‐product otoacoustic emissions were typically reduced in magnitude when white noise was presented to the contralateral ear. This contralateral suppression is attributed to activation of the medial olivocochlear efferent system, which has an inhibitory effect on the cochlear hair cell system. By studying contralateral suppression on cochlear output in subjects of different ages, it is possible to describe aging effects on the medial olivocochlear system. Study Design: CBA mice were divided into three age groups: young adult, middle‐aged, and old‐aged animals (21, 13, and 22 animals per group, respectively), and auditory brainstem responses were obtained before distortion‐product otoacoustic emission testing to assess overall hearing abilities. Methods: 2f1‐f2 distortion‐product otoacoustic emission recordings were obtained from individual subjects (anesthetized with ketamine/xylazine) in each age group under two conditions: 1) in quiet and 2) in the presence of a contralaterally applied wideband noise. Results: Principal findings were that distortion‐product otoacoustic emission levels decreased with age for mice in a way similar to humans, when correcting for the absolute difference in life spans. In addition, contralateral suppression declined in middle‐aged and old‐aged groups relative to the young adults for mice in a manner similar to humans. The contralateral suppression decline at low frequencies preceded that of the decline in distortion‐product otoacoustic emissions with age. Conclusion: Functional decline of the medial olivocochlear efferent system with age precedes outer hair cell degeneration. Loss of medial olivocochlear suppressive function may play a role in the development of presbycusis in both clinical cases and animal models.
A tympanometric comparison of tympanoplasty with cartilage palisades or fascia after surgery for tensa cholesteatoma in children
Authors: Uzun Cem , Cayé‐Thomasen Per , Andersen Janne , Tos Mirko 
Published: November 2003

AbstractObjective: The aim of the present study is to compare the tympanometric and functional findings of cartilage palisade tympanoplasty with those of tympanoplasty with temporalis fascia grafting after one‐stage surgery in children with tensa cholesteatoma. Study Design: In children aged 5 to 15 years (mean, 9.5 years) with tensa cholesteatoma, cartilage palisade tympanoplasty was performed in 32 ears and fascia tympanoplasty in 29 ears. Tympanometry was performed in 31 ears with cartilage palisade tympanoplasty (the palisade group) and 28 ears with fascia tympanoplasty (the fascia group) at follow‐up a median of 48 months after surgical removal of the cholesteatoma (range, 3‐75 months). Main Outcome Measures: Postoperative perforations, tympanometric parameters (tympanogram type, compliance, tympanometric width), and hearing. Results: All postoperative re‐perforations occurred in the fascia group. However, there was no difference between the palisade group and the fascia group in terms of tympanometric parameters, nor between the two groups when dividing into tensa retraction and sinus cholesteatoma subgroups. When comparing the types of tympanoplasty, the type II group reconstructed with cartilage palisades contained a higher number of ears with a normal compliance (0.2‐1.6 mL) but a higher number of ears with a tympanometric width of more than 150 mmH2O. Regarding the number of ears with normal tympanometries, there was no significant difference between the palisade and the fascia group. The late functional hearing results were better in ears reconstructed with cartilage palisades, with functional success in 71%, compared with 54% in the group with fascia grafting. This difference in functional results was particularly pronounced in ears with an abnormal tympanogram (68% vs. 29%). Conclusion: Compared to fascia grafting, the present study showed better late functional hearing results after drum reconstruction using cartilage palisades, despite comparable tympanometric findings. Cartilage palisade reconstruction seems to provide better functional results, especially in ears with a poor tubal function, which is the common situation after cholesteatoma surgery.
Identification of thyroid hormone receptors in the human larynx
Authors: Altman Kenneth W. , Haines G. Kenneth , Vakkalanka Sarah K. , Keni Sanjay P. , Kopp Peter A. , Radosevich James A. 
Published: November 2003

AbstractPurpose: Thyroid hormone is essential for normal development, growth, and function of the majority of tissues. Among the many clinical signs associated with hypothyroidism, alterations in the voice may occur even in cases of mild thyroid failure, suggesting that the larynx is a target tissue for thyroid hormone. The objective of our study is to further understand the effects of thyroid hormone on the larynx by first identifying the presence and locations of its receptors. Methods: Two human cadaveric larynges (one male and one female) were harvested, formalin‐fixed, and paraffin‐embedded. Sections were immunostained with antibodies reactive with the two identified thyroid hormone receptors, TR‐α and TR‐β. The slides were examined under light microscopy. Results: Both male and female specimens revealed consistent patterns of staining for thyroid hormone receptors. The staining pattern for TR‐α included the fibrous connective tissue of the lamina propria, the cartilage, and the glandular elements. The staining pattern for TR‐β included the fibrous connective tissue of the lamina propria only. No receptors were identified in the respiratory mucosa or muscle. Conclusions: Thyroid hormone receptors are present in both the male and the female human larynx. These findings imply a role for thyroid hormone within the human larynx, through both TR‐α and TR‐β.
C‐terminal hydrophobic interactions play a critical role in oligomeric assembly of the P22 tailspike trimer
Authors: Gage Matthew J. , Robinson Anne Skaja 
Published: November 2003

AbstractThe tailspike protein from the bacteriophage P22 is a well characterized model system for folding and assembly of multimeric proteins. Folding intermediates from both the in vivo and in vitro pathways have been identified, and both the initial folding steps and the protrimer‐to‐trimer transition have been well studied. In contrast, there has been little experimental evidence to describe the assembly of the protrimer. Previous results indicated that the C terminus plays a critical role in the overall stability of the P22 tailspike protein. Here, we present evidence that the C terminus is also the critical assembly point for trimer assembly. Three truncations of the full‐length tailspike protein, TSPΔN, TSPΔC, and TSPΔNC, were generated and tested for their ability to form mixed trimer species. TSPΔN forms mixed trimers with full‐length P22 tailspike, but TSPΔC and TSPΔNC are incapable of forming similar mixed trimer species. In addition, mutations in the hydrophobic core of the C terminus were unable to form trimer in vivo. Finally, the hydrophobic‐binding dye ANS inhibits the formation of trimer by inhibiting progression through the folding pathway. Taken together, these results suggest that hydrophobic interactions between C‐terminal regions of P22 tailspike monomers play a critical role in the assembly of the P22 tailspike trimer.
Three‐dimensional crystallization of the Escherichia coli glycerol‐3‐phosphate transporter: A member of the major facilitator superfamily
Authors: Lemieux M. Joanne , Song Jinmei , Kim Myong Jin , Huang Yafei , Villa Anthony , Auer Manfred , Li Xiao‐Dan , Wang Da‐Neng 
Published: November 2003

AbstractHere we report the successful three‐dimensional crystallization of GlpT, the glycerol‐3‐phosphate transporter from Escherichia coli inner membrane. GlpT possesses 12 transmembrane α‐helices and is a member of the major facilitator superfamily. It mediates the exchange of glycerol‐3‐phosphate for inorganic phosphate across the membrane. Approximately 20 phospholipid molecules per protein, identified as negatively charged phosphatidylethanolamine, phosphatidylglycerol, and cardiolipin, were required for the monodispersity of purified GlpT. Analytical size‐exclusion chromatography proved to be efficient in identifying detergents for GlpT monodispersity. Nine such detergents were later used for GlpT crystallization. Screening for crystal nucleation was carried out with a variety of polyethylene glycols as the precipitant over a wide pH range. Subsequent identification of a rigid protein core by limited proteolysis and mass spectroscopy resulted in better‐ordered crystals. These crystals exhibited order to 3.7 Å resolution in two dimensions. However, the stacking in the third dimension was partially disordered. This stacking problem was overcome by using a detergent mixture and manipulating the ionic interactions in the crystallization solution. The resulting GlpT crystals diffracted isotropically to 3.3 Å resolution and were suitable for structure determination by X‐ray crystallography.
Double‐stranded DNA‐induced localized unfolding of HCV NS3 helicase subdomain 2
Authors: Liu Dingjiang , Windsor William T. , Wyss Daniel F. 
Published: November 2003

AbstractThe NS3 helicase of the hepatitis C virus (HCV) unwinds double‐stranded (ds) nucleic acid (NA) in an NTP‐dependent fashion. Mechanistic details of this process are, however, largely unknown for the HCV helicase. We have studied the binding of dsDNA to an engineered version of subdomain 2 of the HCV helicase (d2ΔNS3h) by NMR and circular dichroism. Binding of dsDNA to d2ΔNS3h induces a local unfolding of helix (α3), which includes residues of conserved helicase motif VI (Q460RxxRxxR467), and strands (β1 and β8) from the central β‐sheet. This also occurs upon lowering the pH (4.4) and introducing an R461A point mutation, which disrupt salt bridges with Asp 412 and Asp 427 in the protein structure. NMR studies on d2ΔNS3h in the partially unfolded state at low pH map the dsDNA binding site to residues previously shown to be involved in single‐stranded DNA binding. Sequence alignment and structural comparison suggest that these Arg–Asp interactions are highly conserved in SF2 DEx(D/H) proteins. Thus, modulation of these interactions by dsNA may allow SF2 helicases to switch between conformations required for helicase function.
Aristotle's Two Modal Theses Again
Authors: Makin Stephen 
Published: November 2003

AbstractThis paper offers an interpretation of the arguments Aristotle offers in Metaphysics 9.4, 1047b14-30, for the two modal theses [1] if (if A is the case then B is the case) then (if A is possible then B is possible) [2] if (if A is possible then B is possible) then (if A is the case then B is the case) Aristotle's arguments for these theses have not typically impressed commentators. I offer two arguments which are relatively faithful to Aristotle's text. The arguments rest on the following pair of claims concerning conditionals and possibility respectively [COND] 'if A then B' is true if and only if in any circumstances in which A obtains, B obtains also [TEST] 'possibly A' is true in a range of circumstances C1 . . . Cn if and only if assuming A true in any Ci gives rise to no impossibilities, once any further required adjustments are taken into account The arguments and the premises on which they rest are stated without formalisation of the theses [1] and [2]. The argument for [1] is a defensible and persuasive argument. The argument for [2] is invalid, though plausible. That is consistent with our differential verdicts on [1] and [2]. [2] appears to be false: the argument provided for [2] explains why Aristotle might nevertheless have asserted it. The aim of the paper is to justify a more positive verdict on Aristotle's arguments than is usual among commentators.