bluuebunny/crossref_metadata_2025 huggingface dataset:
Laser frequency stabilization to excited state transitions using electromagnetically induced transparency in a cascade system
Authors: Abel R. P. , Mohapatra A. K. , Bason M. G. , Pritchard J. D. , Weatherill K. J. , Raitzsch U. , Adams C. S.
Published: February 2009

We demonstrate laser frequency stabilization to excited state transitions using cascade electromagnetically induced transparency. Using a room temperature Rb vapor cell as a reference, we stabilize a first diode laser to the D2 transition and a second laser to a transition from the intermediate 5P3/2 state to a highly excited state with principal quantum number n=19–70. A combined laser linewidth of 280±50 kHz over a 100 μs time period is achieved. This method may be applied generally to any cascade system and allows laser stabilization to an atomic reference in the absence of a direct absorption signal.
Multiferroicity with high-TC in ceramics of the YBaCuFeO5 ordered perovskite
Authors: Kundys B. , Maignan A. , Simon Ch.
Published: February 2009

A dielectric anomaly has been found near the incommensurate to commensurate antiferromagnetic phase transition (TN2≈230 K) in YBaCuFeO5 ceramics, a compound which crystallizes in an ordered perovskite structure. The existence of electric polarization below TN2 suggests the magnetism induced charge polarization effect that is also confirmed by its strong magnetic field dependence below TN2. Accordingly, the peak near TN2 of the magnetodielectric effect indicates a maximum of magnetodielectric susceptibility near the spin reorientation transition. Considering the abundance of magnetic compounds which structures derive from the perovskite, these results might open up the way toward the control of electric polarization near room temperature.
Time-dependent gas phase kinetics in a hydrogen diluted silane plasma
Authors: Nunomura S. , Yoshida I. , Kondo M.
Published: February 2009

The gas phase kinetics in a high-pressure hydrogen diluted silane plasma has been studied at time scales of 10−2–6×102 s. The time-resolved gas phase composition shows the following kinetics at different time scales: silane decomposition and polysilane generation in ≲2×10−1 s, nanoparticle formation and plasma density reduction in 10−1–100 s, polysilane accumulation in 100–102 s, and silane depletion and electrode heating in ≳101 s. Disilane radicals are implied to be the dominant film precursors in addition to silyl radicals.
Low temperature effects on the response time of liquid crystal displays
Authors: Rao Linghui , Gauza Sebastian , Wu Shin-Tson
Published: February 2009

Low temperature effects on the liquid crystal response time for mobile displays are investigated. We studied the rotational viscosity and elastic constants of two commercial liquid crystal mixtures in the range from −20 to 60 °C. At low temperatures, rotational viscosity still follows the modified Arrhenius law well but elastic constants are ∼30%–40% larger than those expected from mean-field theory. The responsible mechanism for this anomalous behavior originates from the increased fourth rank of order parameter at low temperatures.
The White Geography of Lawren Stewart Harris: Whiteness and the Performative Coupling of Wilderness and Multiculturalism in Canada
Authors: Baldwin Andrew
Published: February 2009

Wilderness and multiculturalism are frequently invoked as central features of the official national imagination in Canada, but seldom are these foundational ideas recognized as genealogically proximate. Instead, both are routinely made to occupy discrete cognitive spaces, with the effect being that they are reified as distinct zones of Canadian life, and imagined as having emerged at two very distinct moments in the Canadian national narrative. Against the grain of this conventional interpretation, this paper offers a counterreading of wilderness and multiculturalism in Canadian political culture—one that seeks to disrupt their presupposed autonomy by rendering them simultaneous moments in a particular racialized historical geography. The paper elaborates this proposition by critically examining two popular works by Canadian landscape painter Lawren Stewart Harris. It concludes with some remarks on the political implications of the argument.
Fluoroquinolones from Imidoylketenes and Iminopropadienones, R - N=C=C=C=O
Authors: Fulloon Belinda E. , Wentrup Curt
Published: February 2009

3-Fluoro-, 4-fluoro-, and 2,3,4-trifluorophenyliminopropadienones have been generated by flash vacuum thermolysis (FVT) of 5-[(fluoroarylamino)methoxymethylene]-2,2-dimethyldioxan-4,6-dione (Meldrum’s acid) derivatives. Their reaction with methanol affords interconverting imidoylketenes and oxoketenimines, which are employed in a synthesis of fluoroquinolones. The same quinolones are obtained from methyl 1-fluoroaryl-1,2,3-triazole-4-carboxylates, which on FVT eliminate N2 to generate oxoketenimines. Rearrangement of the oxoketenimines to imidoylketenes and cyclization afford the quinolones.
Long-term effects of two sizes of surgically implanted acoustic transmitters on a predatory marine fish (Pomatomus saltatrix)
Authors: Thorstad Eva B. , Kerwath Sven E. , Attwood Colin G. , Økland Finn , Wilke Christopher G. , Cowley Paul D. , Næsje Tor F.
Published: February 2009

Fish telemetry is increasingly used to study fish behaviour in marine systems and it is crucial that the tagging does not affect fish behaviour and welfare negatively. Hence, the long-term effects of surgically implanted acoustic telemetry transmitters on survival, tag retention, healing and growth on Pomatomus saltatrix (known as tailor in Australia, elf in South Africa and bluefish in North America) were studied over 144 days. P. saltatrix are well suited for transmitter implants because no tagging-related short- or long-term mortality or transmitter expulsion was recorded. Small transmitters (9 × 28 mm, 3.3 g in water) did not affect the specific growth rate of tagged fish compared with an untagged control group. In contrast, the fish tagged with large transmitters (13 × 50 mm, 6.9 g in water) had a reduced specific growth rate. The small, but not the large transmitter, seemed suitable for tagging P. saltatrix of the body sizes represented in this study (215–621 g). The specific growth rate was negatively affected by increasing the transmitter-mass-in-water to body-mass ratio. It is recommended that this ratio should not exceed 1.4%.
Effect of cholesterol on the structure of a phospholipid bilayer
Authors: de Meyer Frédérick , Smit Berend
Published: February 2009

Cholesterol plays an important role in regulating the properties of phospholipid membranes. To obtain a detailed understanding of the lipid–cholesterol interactions, we have developed a mesoscopic water–lipid–cholesterol model. In this model, we take into account the hydrophobic–hydrophilic interactions and the structure of the molecules. We compute the phase diagram of dimyristoylphosphatidylcholine–cholesterol by using dissipative particle dynamics and show that our model predicts many of the different phases that have been observed experimentally. In quantitative agreement with experimental data our model also shows the condensation effect; upon the addition of cholesterol, the area per lipid decreases more than one would expect from ideal mixing. Our calculations show that this effect is maximal close to the main-phase transition temperature, the lowest temperature for which the membrane is in the liquid phase, and is directly related to the increase of this main-phase transition temperature upon addition of cholesterol. We demonstrate that no condensation is observed if we slightly change the structure of the cholesterol molecule by adding an extra hydrophilic head group or if we decrease the size of the hydrophobic part of cholesterol.
Mlp1 Acts as a Mitotic Scaffold to Spatially Regulate Spindle Assembly Checkpoint Proteins inAspergillus nidulans
Authors: De Souza Colin P. , Hashmi Shahr B. , Nayak Tania , Oakley Berl , Osmani Stephen A.
Published: February 2009

During open mitosis several nuclear pore complex (NPC) proteins have mitotic specific localizations and functions. We find that the Aspergillus nidulans Mlp1 NPC protein has previously unrealized mitotic roles involving spatial regulation of spindle assembly checkpoint (SAC) proteins. In interphase, An-Mlp1 tethers the An-Mad1 and An-Mad2 SAC proteins to NPCs. During a normal mitosis, An-Mlp1, An-Mad1, and An-Mad2 localize similarly on, and around, kinetochores until telophase when they transiently localize near the spindle but not at kinetochores. During SAC activation, An-Mlp1 remains associated with kinetochores in a manner similar to An-Mad1 and An-Mad2. Although An-Mlp1 is not required for An-Mad1 kinetochore localization during early mitosis, it is essential to maintain An-Mad1 in the extended region around kinetochores in early mitosis and near the spindle in telophase. Our data are consistent with An-Mlp1 being part of a mitotic spindle matrix similar to its Drosophila orthologue and demonstrate that this matrix localizes SAC proteins. By maintaining SAC proteins near the mitotic apparatus, An-Mlp1 may help monitor mitotic progression and coordinate efficient mitotic exit. Consistent with this possibility, An-Mad1 and An-Mlp1 redistribute from the telophase matrix and associate with segregated kinetochores when mitotic exit is prevented by expression of nondegradable cyclin B.
The Cellular Concentration of the Yeast Ure2p Prion Protein Affects Its Propagation as a Prion
Authors: Crapeau Myriam , Marchal Christelle , Cullin Christophe , Maillet Laurent
Published: February 2009

The [URE3] yeast prion is a self-propagating inactive form of the Ure2p protein. We show here that Ure2p from the species Saccharomyces paradoxus (Ure2pSp) can be efficiently converted into a prion form and propagate [URE3] when expressed in Saccharomyces cerevisiae at physiological level. We found however that Ure2pSpoverexpression prevents efficient prion propagation. We have compared the aggregation rate and propagon numbers of Ure2pSpand of S. cerevisiae Ure2p (Ure2pSc) in [URE3] cells both at different expression levels. Overexpression of both Ure2p orthologues accelerates formation of large aggregates but Ure2pSpaggregates faster than Ure2pSc. Although the yeast cells that contain these large Ure2p aggregates do not transmit [URE3] to daughter cells, the corresponding crude extract retains the ability to induce [URE3] in wild-type [ure3-0] cells. At low expression level, propagon numbers are higher with Ure2pScthan with Ure2pSp. Overexpression of Ure2p decreases the number of [URE3] propagons with Ure2pSc. Together, our results demonstrate that the concentration of a prion protein is a key factor for prion propagation. We propose a model to explain how prion protein overexpression can produce a detrimental effect on prion propagation and why Ure2pSpmight be more sensitive to such effects than Ure2pSc.
ULK-Atg13-FIP200 Complexes Mediate mTOR Signaling to the Autophagy Machinery
Authors: Jung Chang Hwa , Jun Chang Bong , Ro Seung-Hyun , Kim Young-Mi , Otto Neil Michael , Cao Jing , Kundu Mondira , Kim Do-Hyung
Published: February 2009

Autophagy, the starvation-induced degradation of bulky cytosolic components, is up-regulated in mammalian cells when nutrient supplies are limited. Although mammalian target of rapamycin (mTOR) is known as the key regulator of autophagy induction, the mechanism by which mTOR regulates autophagy has remained elusive. Here, we identify that mTOR phosphorylates a mammalian homologue of Atg13 and the mammalian Atg1 homologues ULK1 and ULK2. The mammalian Atg13 binds both ULK1 and ULK2 and mediates the interaction of the ULK proteins with FIP200. The binding of Atg13 stabilizes and activates ULK and facilitates the phosphorylation of FIP200 by ULK, whereas knockdown of Atg13 inhibits autophagosome formation. Inhibition of mTOR by rapamycin or leucine deprivation, the conditions that induce autophagy, leads to dephosphorylation of ULK1, ULK2, and Atg13 and activates ULK to phosphorylate FIP200. These findings demonstrate that the ULK-Atg13-FIP200 complexes are direct targets of mTOR and important regulators of autophagy in response to mTOR signaling.
Sclerosing Rhabdomyosarcoma: A Rare Variant With Predilection for the Head and Neck
Authors: Knipe Thomas A. , Chandra Rakesh K. , Bugg M Frederick
Published: February 2009

Objectives/Hypothesis: Sclerosing rhabdomyosarcoma is a newly described variant of rhabdomyosarcoma with a predilection for the head and neck. Little has been written on the topic, because of the scarcity of the disease and its recent recognition as a distinct entity. The present report describes the fifth confirmed case of sclerosing rhabdomyosarcoma and is the first report in the otolaryngology literature.

Study Design: Case report.

Methods: The authors have reported the case of a 66‐year‐old woman with a 35‐year history of heavy cigarette smoking and daily alcohol consumption and a 2‐month history of progressive dysphagia and dysarthria secondary to an enlarging tongue mass. Urgent tracheotomy was performed for impending respiratory embarrassment. Direct laryngoscopy revealed a bulky, exophytic mass involving the base of tongue. Specimens were obtained and submitted for analysis.

Results: Initial frozen‐section analysis of the specimens favored carcinoma, although subsequent immunohistochemical analysis disproved this. The diagnosis of sclerosing rhabdomyosarcoma was based on microscopic appearance and patterns of gene expression, including the expression of desmin and myogenin. A search of the literature revealed only four confirmed cases of sclerosing rhabdomyosarcoma. With the inclusion of the oropharyngeal tumor in the present report, three of the five confirmed cases have occurred in the head and neck.

Conclusion: Sclerosing rhabdomyosarcoma is a rare variant of rhabdomyosarcoma that has a predilection for the head and neck. The clinical presentation may mimic carcinoma. The otolaryngologist—head and neck surgeon must be familiar with this disease entity.
National Assessment of Business‐of‐Medicine Training and Its Implications for the Development of a Business‐of‐Medicine Curriculum
Authors: Patel Anit T. , Bohmer Richard M. J. , Barbour J Robert , Fried Marvin P.
Published: February 2009

Objectives/Hypothesis: The objectives were, first, to determine the current state of business training in otolaryngology residency programs in the United States and, second, to lay the groundwork for development of a business‐of‐medicine (BOM) curriculum.

Study Design: Cross‐sectional survey.

Methods: A survey concerning methodology and topics for management training of residents was mailed to the chairpersons or program directors of the 102 otolaryngology residency programs. A similar survey was sent to 576 otolaryngology graduates (classes of 2000, 2001, and 2002). An interactive BOM curriculum on CD‐ROM was developed based on the results.

Results: The response rate among program directors was 74.5% (76 of 102), and among the otolaryngology graduates, 38.2% (220 of 575). Seventy‐five percent of graduates rated their BOM training as poor or fair. Only 8% rated their BOM training as excellent. Twenty percent of the graduates responded to having a BOM course during residency. Recent graduates reported that a BOM course can best be taught through lectures and apprenticeship/mentoring, whereas program directors reported that a BOM course can best be taught through lectures and outside consultants. Graduates reported that coding compliance was the topic most neglected in residency, whereas program directors reported that coding compliance was the main topic covered in the business training. Both groups agreed that department attending physicians have the most impact on a resident's business training. Program directors reported that correct coding, planning one's entry into medical practice, risk management, and reimbursement issues are the most important topics for residents to learn, whereas recent graduates stated that the most important topics should be correct coding, office management, risk management, and reimbursement.

Conclusion: The present study reflects a perceived necessity for improvement of BOM training in otolaryngology residency programs. Based on this finding, the outcome measures from the survey, and the authors' own experience from business courses given in the first author's department, a BOM curriculum was developed that is general enough to target all otolaryngology residents and intended to provide business skills which result in improved use of resources and, ultimately, higher quality of care.
Alterations of Nasal Mucociliary Clearance in Association with HIV Infection and the Effect of Guaifenesin Therapy
Authors: Rosen Elizabeth J. , Calhoun Karen H.
Published: February 2009

Objectives: To determine if human immunodeficiency virus (HIV) infection is associated with a prolonged mucociliary clearance time (MCT) and to evaluate the effect of guaifenesin on MCT in HIV+ patients.

Study Design: A cross‐sectional study comparing HIV+ and HIV− volunteers followed by a prospective, randomized, double‐blind, placebo‐controlled study of HIV+ patients before and after guaifenesin treatment.

Methods: Twenty‐five HIV+ patients and 29 HIV− controls were enrolled and MCT was measured using the saccharin method. A separate group of 20 HIV+ patients participated in the second arm of the study and underwent saccharin testing before and after a 3‐week course of guaifenesin or placebo. All study participants completed a medical history questionnaire, a sinonasal symptom (SNOT‐16) survey, and were examined with both anterior rhinoscopy and rigid nasal endoscopy.

Results: There was a significant difference (P < .002) in the MCT between the HIV+ group (13.3 ± SD 7.5 minutes) and the HIV− controls (9.2 ± SD 3.9 minutes). The difference in MCT between the guaifenesin and placebo groups did not reach statistical significance (P >.05). The HIV+ group had a higher SNOT‐16 score compared to HIV− controls (21.1 vs. 7.4, P < .001). Guaifenesin therapy in HIV+ patients led to a significant improvement in the SNOT‐16 score (P < .05).

Conclusions: Compared to HIV− controls, HIV+ patients have a prolonged MCT and more sinonasal symptoms as indicated by a higher SNOT‐16 score. Guaifenesin therapy was associated with improved SNOT‐16 scores, although there was not a detectable improvement in MCT. Use of guaifenesin in HIV+ patients with sinonasal disease may lead to improved patient perception of quality of life
Gastrostomy Tubes in Patients with Advanced Head and Neck Cancer
Authors: Ahmed Khwaja Asif , Samant Sandeep , Vieira Francisco
Published: February 2009

Objectives: To measure the percentage of patients requiring gastrostomy tubes (G‐tubes) and the timing of their placement, in addition to studying whether pretreatment variables (T stage, tumor site, N stage) and intratreatment variables (weight loss during treatment) are valid predictors for the need for G‐tube placement.

Study Design: Retrospective case control study.

Methods: Retrospective review of a prospectively collected database with chart reviews was carried out on 477 patients treated on a regimen of intraarterial cisplatin and concurrent radiation. The likelihood of requiring a G‐tube was calculated by studying several independent variables using chi‐square analysis and the unpaired t test.

Results: Two hundred twenty (46%) patients had G‐tubes placed, with mean time of placement being on day 20 after the initiation of treatment. Patients with T4 disease were statistically more likely to require a G‐tube (50% vs. 37%, P < .05). Patients were less likely to require a G‐tube when the primary site of tumor involved the larynx or paranasal sinuses (P < .05). There were no statistically significant differences between the two groups with regards to patient age, sex, N stage, and weight changes over the course of treatment. The odds of requiring a G‐tube were highest for tumors involving the hypopharynx (80%), oral cavity (52%), and oropharynx (49%).

Conclusions: Although clinical judgment appears to be sufficient for deciding when G‐tube placement is warranted in our population, the threshold for placing a tube should be lower in those patients who had a higher likelihood of requiring a G‐tube during the course of treatment, including those with advanced disease of the oral cavity, oropharynx, and hypopharynx.
Endoscopic Surgery of the Anterior Skull Base
Authors: Casler John D. , Doolittle Andrew M. , Mair Eric A.
Published: February 2009

Objectives/Hypothesis: Traditional surgical approaches to the anterior skull base often involve craniotomy, facial incisions, disruption of skeletal framework, tracheotomy, and an extended hospital stay. As experience with endoscopic sinus surgery has grown, the techniques and equipment have been found to be adaptable to treatment of lesions of the anterior and central skull base. A minimally invasive endoscopic approach theoretically offers the advantages of avoiding facial incisions, osteotomies, and tracheotomy; surgery should be less painful, recovery quicker, and hospital stays should be shorter. The study attempted to assess endoscopic approaches to the anterior and central skull base for its ability to achieve those goals.

Study Design: Retrospective review of 72 cases performed at a single institution from November 1996 to July 2003. A subgroup of 15 patients who underwent endoscopic approach to their pituitary tumors was compared with a similar group of 15 patients who underwent traditional open trans‐sphenoidal surgery for their pituitary tumors.

Methods: Patient records were analyzed and information tabulated for age, sex, disease, location of lesion, operative time, use of image‐guided surgical systems, blood loss, length of intensive care unit stay, duration of operative pain, length of postoperative hospitalization, complications, and completeness of resection.

Results: Of the cases, 86.1% were performed exclusively endoscopically, and 13.9% used a combination of endoscopic and open techniques. An image‐guided surgical system was used in 83% of cases. Hospital length of stay was 2.3 days for the exclusively endoscopic group as opposed to 8 days for the combined group. With the patients with pituitary tumors, operative times were similar between the two groups (255.13 vs. 245.73 min), blood loss was less in the endoscopic group (125.33 vs. 243.33 mL), pain duration was shorter in the endoscopic group (10 of 15 patients pain free on postoperative day 1 vs. 2 of 15 patients pain free in the open group), and intensive care unit stay and hospital length of stay were both shorter in the endoscopic group. Complication rates and completeness of resection was similar in both groups, although the open group had a higher rate of complications related to the approach to the sella.

Conclusion: The study demonstrated the safety and efficacy of judicious endoscopic approaches to anterior skull base lesions. An outcomes assessment in pituitary surgery demonstrates advantages of an endoscopic approach in appropriate cases.
Intraoperative Intact Parathyroid Hormone Level Monitoring as a Guide to Parathyroid Reimplantation after Thyroidectomy
Authors: Friedman Michael , Vidyasagar Ramakrishnan , Bliznikas Darius , Joseph Ninos J.
Published: February 2009

Objective: The goal of this study was to determine whether intraoperative intact parathyroid hormone (IOiPTH) levels can predict the functional status of remaining parathyroids at the end of total thyroidectomy and thereby be a guide for parathyroid autotransplantation when glands are deemed not functional.

Study Design: Prospective study involving 23 patients undergoing either total thyroidectomy or completion thyroidectomy

Methods: During surgery, an attempt was made to identify all four parathyroid glands. Normal size vascular glands were preserved, whereas avascular glands were microdissected and reimplanted. Serial IOiPTH was measured preoperatively after each parathyroid was identified, manipulated, or removed and serum iPTH measurements were done postoperatively up to 56 days.

Results: The sensitivity of low IOiPTH in identifying a devascularized gland was 88.9%, and specificity was 92.9%. A normal IOiPTH level indicates at least two functioning glands. IOiPTH levels between 1.5 and 10 pg/mL indicate only one functional gland. Undetectable IOiPTH levels indicate no residual functioning gland.

Conclusions: For patients undergoing total or completion thyroidectomy, IOiPTH should be routinely measured at the end of the procedure, and a level less than 10 pg/mL requires reassessment of remaining parathyroid glands. Vascularized glands should be preserved regardless of IOiPTH levels. Devascularized glands or glands of questionable vascularity should be considered for autotransplantation.
Acoustic Neuromas after Failed Radiation Therapy: Challenges of Surgical Salvage
Authors: Limb Charles J. , Long Donlin M. , Niparko John K.
Published: February 2009

Objectives: As stereotactic radiation has emerged as a treatment option for acoustic neuromas, cases that require surgical salvage after unsuccessful radiation have emerged. We present a comparison of the technical challenges faced by the surgeons in the treatment of irradiated versus nonirradiated acoustic neuromas.

Study Design: Matched case‐control series.

Methods: We identified nine patients with acoustic neuromas that required surgical resection after radiation therapy. Cases were performed with suboccipital and translabyrinthine approaches. Nine nonirradiated case‐control subjects matched for age, sex, tumor size, and surgical approach were identified for purposes of general comparison. Operative findings and outcomes were compared for the two groups.

Results: Surgical removal was found to be significantly more difficult after radiation therapy because of increased fibrosis and adhesion to adjacent nervous structures, particularly at the porus acousticus. Excessive scarring hindered identification of the facial nerve and added uncertainty as to the completeness of tumor removal. Decompression of the internal auditory canal (IAC) dura and resection of neoplasm in the IAC before cerebellopontine angle dissection was required for facial nerve identification. Operative time was significantly longer for irradiated cases, and facial nerve outcomes tended to be poorer, particularly when facial nerve dysfunction prompted the salvage procedure.

Conclusions: Surgical salvage of acoustic neuromas after radiation therapy is feasible, but it presents technical challenges beyond that associated with primary surgical therapy. Poorer outcomes of postoperative cranial nerve status were caused primarily by anatomic changes at the nerve/tumor interface. As surgical experience with the irradiated acoustic neuroma grows, operative observations should be incorporated into the counsel provided to patients with acoustic neuromas as they weigh different management options.
Experimental and Clinical Studies of Malleus Fixation
Authors: Nakajima Hideko Heidi , Ravicz Michael E. , Rosowski John J. , Peake William T. , Merchant Saumil N.
Published: February 2009

Objectives/Hypothesis: Preoperative clinical diagnosis of malleus fixation can be difficult. “Fixation” of the malleus can be caused by various disorders or diseases: fibrous tissue, bony spurs, and neo‐osteogenesis around the malleus head or stiffening of the anterior malleal ligament. The conductive hearing loss produced by these disorders or diseases has not been well characterized. The study goals were 1) to determine the effects of various types of malleus fixation using a cadaveric temporal bone preparation and 2) to assess the clinical utility of umbo velocity measurements in preoperative differential diagnosis of malleus fixation and stapes fixation.

Methods: Umbo and stapes velocity were measured in 18 fresh cadaveric human temporal bones with laser vibrometry before and after controlled application of adhesives to the malleus, stapes, or both ossicles.

Results: Each simulated pathological condition produced a specific degree of loss in stapes velocity: stiffening of anterior malleal ligament, 0 to 8 dB; fibrous tissue around malleus head, less than 10 dB; bony bar to malleus head, 10 to 30 dB; and extensive neo‐osteogenesis around malleus head, greater than 35 dB. Simulated malleus fixations generally produced similar reductions in both umbo and stapes velocity. Stapes fixation reduced stapes velocity with little change in umbo velocity. Because the change in stapes velocity would be similar to conductive hearing loss, experimental results were directly compared with clinical measurements of umbo velocity in surgically confirmed cases of malleus or stapes fixation. The effects of malleus and stapes fixations between the clinical and experimental data were similar.

Conclusion: The study showed that measurements of umbo velocity and air‐bone gap can enable one to diagnose malleus fixation and specifies how to differentiate malleus from stapes fixation.
Time and Dose Effects of Mitomycin C on Extracellular Matrix Fibroblasts and Proteins
Authors: Ferguson Bryce , Gray Steven D. , Thibeault Susan
Published: February 2009

Objectives/Hypothesis: The objective was to determine treatment dose and time‐dependent effects of injected mitomycin C on extracellular matrix fibroblasts, collagen, and fibronectin, important mediators in the wound healing response, in a rat cutaneous wound model.

Study Design: A prospective, controlled animal study.

Methods: Forty rats were injected with three different doses (0.4, 2.3, and 5.0 mg/mL) of mitomycin C at three different wound sites with a fourth wound site receiving saline as a control. The rats were grouped to have their tissue harvested at five different dates ranging from 1 week to 8 weeks. After death, samples from the wound site underwent Western blot analysis for collagen and fibronectin and histological analysis measuring fibroblast apoptosis.

Results: Over an 8‐week period, collagen and fibronectin significantly decreased and fibroblast apoptosis significantly increased. No correlation was found between the injected dose of mitomycin C and either the extracellular matrix protein concentration or the rate of fibroblast apoptosis.

Conclusion: Mitomycin C demonstrated a long‐term effect in a wound, inhibiting collagen and fibronectin production and inducing apoptosis. Use of mitomycin C in excess of 0.4 mg/mL did not alter protein concentrations or rate of apoptosis.
Design and Implementation of an Ambulatory pH Monitoring Protocol in Patients with Suspected Laryngopharyngeal Reflux
Authors: Harrell Steve , Evans Ben , Goudy Steve , Winstead Welby , Lentsch Eric , Koopman Jennifer , Wo John M.
Published: February 2009

Objective/Hypothesis: Adding a hypopharyngeal sensor to esophageal pH monitoring has been advocated for laryngopharyngeal reflux (LPR). However, selecting the proper pH catheter is problematic because esophageal lengths are variable among individuals.

Objective: To design and implement a new pH monitoring protocol for LPR.

Study Design/Methods: Design parameters were defined prospectively: single‐probe, triple‐sensor pH catheter with sensors located in the hypopharynx (1–3 cm above upper esophageal sphincter) and in proximal and distal esophagus (20 cm and 5 cm above lower esophageal sphincter, respectively). Esophageal lengths were determined in a study population undergoing esophageal manometry. Optimal pH sensor spacings were determined using the least number of catheters to satisfy the design parameters. The protocol was implemented in consecutive subjects with suspected LPR.

Results: Distribution of esophageal lengths was determined in 1,043 subjects. In 92% of the study population, three pH catheters (3–15, 6–15, and 9–15 sensor‐spacings) would satisfy the design criteria. Forty‐one subjects with suspected LPR underwent the pH protocol. An abnormal pH test was found in 40 subjects (98%) with triple‐sensor combination compared with 29 subjects (71%) if only dual esophageal sensors were used.

Conclusions: Single‐probe pH monitoring of the hypopharynx and esophagus was feasible. Adding a hypopharyngeal pH sensor increased the detection of abnormal acid reflux more often than traditional dual‐sensor esophageal pH monitoring.
Function of the Laryngeal Mechanoreceptors During Vocalization
Authors: Gozaine Teofilo C. , Clark Keith F.
Published: February 2009

Objectives/Hypothesis: The objective was to compare the activity of superior laryngeal nerve mechanoreceptors based on a respiration‐based classification protocol with activities found using a vocalization‐based classification protocol in adult cats.

Study Design: Animal study.

Methods: In the first part of the experiment, single fiber action potentials from the internal branch of the superior laryngeal nerve were recorded in decerebrated cats using a respiration‐based classification protocol to identify laryngeal mechanoreceptors as pressure, flow, and drive receptors, as described in the literature. A tracheal T‐tube and a laryngeal mask airway were necessary modifications to perform this protocol. In the second part of the experiment, a vocalization‐based classification protocol as described in the literature was used to classify the activity of the same fiber into the following groups: peak prephonatory, frequency‐following, frequency‐nonfollowing, inspiratory‐modulated, or mixed. Vocalization was evoked by electrical stimulation of the midbrain in the region of the periaqueductal gray.

Results: In all, eight cats were used for the experiment. Data were obtained from only three cats for a total of five single fibers. Results from five cats were not obtained because of inability to phonate (in three cats) and inability to record from the superior laryngeal nerve (in two cats). We identified two flow receptors, a drive receptor, a frequency‐following receptor, and a frequency‐nonfollowing receptor. Both flow receptor fibers were almost silent during the phonation phase and reached the maximum activity after vocalization during the inspiratory phase. The drive receptor was active during all four airway maneuvers and was most active during tracheal occlusion. It also kept a high level of activity during the phonatory phase, suggesting a role in the modulation of vocalization and respiration. The next two receptors, a frequency‐following and a frequency‐nonfollowing receptor, were active only during the phonatory phase and were totally inactive during the airway maneuvers, suggesting a role only during the vocalization behavior.

Conclusion: Because vocalization is an important stimulus for the activation of certain superior laryngeal nerve receptors, a classification protocol based on respiration alone is incomplete. Classification into pressure, flow, and drive receptors alone is not appropriate for the study of laryngeal receptors during vocalization. Some frequency‐following and frequency‐nonfollowing receptors may be active only during phonation and would otherwise be missed without vocalization stimuli.
Osteoprotegerin in the Inner Ear May Inhibit Bone Remodeling in the Otic Capsule
Authors: Zehnder Andreas F. , Kristiansen Arthur G. , Adams Joe C. , Merchant Saumil N. , McKenna Michael J.
Published: February 2009

Objectives: To elucidate factors that may be responsible for the inhibition of remodeling of bone within the otic capsule.

Methods: Expression of osteoprotegerin (OPG), receptor activator of nuclear factor kappa B (RANK), and RANK ligand (RANKL) were assayed in samples of bone obtained from the otic capsule, calvarium, and femur, and from the soft tissue within the cochlea using semiquantitative reverse transcriptase polymerase chain reaction (RT‐PCR) in mice. Immunostaining was used for histologic localization of the gene products. An enzyme‐linked immunosorbent assay (ELISA) was used to quantify the amount of OPG within perilymph, serum, and cerebrospinal fluid. The micro‐anatomy of the interface between the otic capsule and the fluid spaces of the cochlea was investigated by brightfield and phase‐contrast microscopy and by three‐dimensional reconstruction in the mouse and human.

Results: OPG, a powerful inhibitor of bone remodeling, was expressed at extremely high levels within the soft tissue of the cochlea and was present in the perilymph at very high concentrations. The OPG produced within the inner ear may diffuse into the surrounding otic capsule, where it may be responsible for inhibition of bone turnover. Our anatomic studies revealed an extensive system of interconnected canaliculi within the otic capsule that had direct openings into the fluid spaces of the inner ear, thus providing a possible anatomic route for the diffusion of OPG from the inner ear into the surrounding bone.

Conclusion: OPG, a potent inhibitor of osteoclast formation and function, is expressed at high levels within the inner ear and is secreted into the perilymph and the surrounding bone and may serve to inhibit active bone remodeling within the otic capsule, especially immediately adjacent to the cochlea. By this means, the cochlear soft tissue may control the nature of the surrounding petrous bone.
The Dix‐Hallpike Test and The Canalith Repositioning Maneuver
Authors: Viirre Erik , Purcell Ian , Baloh Robert W.
Published: February 2009

The Dix‐Hallpike test and the canalith repositioning maneuver (CRM) are used to diagnose and treat benign positional vertigo (BPV). Dix‐Hallpike is the standard procedure for diagnosis of BPV, but if the horizontal canal is not tested for BPV and the Dix‐Hallpike is only carried out once, the condition may not be diagnosed and appropriately treated. We describe our method of testing for BPV and treating it with CRM. The Dix‐Hallpike test involves rapidly moving the patient from a sitting position to “head hanging,” where the patient's head is at least 10 degrees below horizontal. This is performed initially for the posterior semicircular canals. If these movements fail to elicit vertigo and nystagmus, tests of the horizontal semicircular canals are performed by laying the patient on each side. Importantly, if there is no vertigo or nystagmus elicited by testing the horizontal semi‐circular canals, the posterior semicircular canals are tested again. It appears that being held in the head hanging positions and then left and right lateral positions will often allow the canaliths to collect such that the Dix‐Hallpike test will become positive. Failure to repeat the tests of the posterior semicircular canals may result in a falsely negative test. Testing the horizontal canals and repeating the Dix‐Hallpike test will reduce the likelihood of patients undergoing extra testing or other consequences of misdiagnosis. If, during any of this testing, a movement elicits vertigo or nystagmus, the appropriate CRM is then carried out.
Influence of Polyps on Outcomes After Endoscopic Sinus Surgery
Authors: Bhattacharyya Neil
Published: February 2009

Objective: To determine clinical and comparative outcomes for endoscopic sinus surgery (ESS) for chronic rhinosinusitis (CRS) with polyposis.

Methods: Two cohorts of adult patients with refractory CRS with and without nasal polyps were prospectively studied before and after ESS (minimum follow‐up, 12 months) with the Rhinosinusitis Symptom Inventory (RSI). For the non‐polyp and polyp cohorts, RSI symptom domains and medical resource utilization were compared in the preoperative and postoperative states. Corresponding effect sizes were computed and compared between cohorts to determine the effect of polyps on prognosis after ESS.

Results: A total of 165 non‐polyp and 86 polyp patients were enrolled. Polyps were more common in female patients (2:1, P = .025); age (mean, 42.9 years) and follow‐up (18.5 months) were similar between groups. Lund scores were significantly higher for polyp patients (13.7, SD 4.8) vs. non‐polyp patients (8.1, SD 5.3, P < .001). At baseline, polyp patients reported lower symptom scores for facial, oropharyngeal, and systemic RSI symptom domains (all P < .012); nasal and total symptom domains were similar between groups. Both non‐polyp and polyp groups obtained significant symptomatic benefit from ESS with effect sizes for RSI symptom domain improvements ranging from 0.89 to 1.38 and 0.43 to 1.19, respectively (all P < .001). There were no significant differences between groups in symptomatic improvement, excepting oropharyngeal symptoms (better improvement in non‐polyp group, P = .024). Non‐polyp patients decreased medical resource consumption more significantly than did polyp patients.

Conclusions: Both non‐polyp and polyp patients derive similar clinically significant symptomatic improvement after ESS. These similarities suggest that polyp patients do not necessarily have a poorer symptomatic outcome after ESS.
Voice Outcomes of Polyacrylamide Hydrogel Injection Laryngoplasty
Authors: Lee Seung Won , Son Young‐Ik , Kim Chan Hee , Lee Jae Yong , Kim Shi Chan , Koh Yoon Woo
Published: February 2009

Objectives: Polyacrylamide hydrogel (PAAG, Aquamid) is widely used as permanent facial tissue filler during facial plastic surgery. In this study, we examined the long‐term effects and safety aspects of PAAG as a vocal fold augmentation material for patients with permanent unilateral vocal cord paralysis.

Study Design: Prospective clinical trials.

Methods: PAAG injection laryngoplasty was performed in 34 consecutive patients with permanent unilateral vocal cord paralysis. Percutaneous injection was performed under local anesthesia into the vocalis muscle using disposable 25 gauge long needles. Of the 34 patients, 16 completed acoustic, perceptual, stroboscopic, and subjective evaluations prior to the injection and at 6 and 12 months after the injection.

Results: Acoustic and perceptual parameters (GRBAS [Overall grade of dysphonia, Roughness, Breathiness, Aesthenia, Strain], Maximal phonation time [MPT], jitter, and shimmer) were significantly improved (P < .05) after injection and remained stable over 12 months. The grades of mucosal waves and glottic closure were also significantly improved (P < .01). The voice handicap index (VHI), as well as the visual analogue scale (VAS) of hoarseness and aspiration significantly improved over 12 months. No adverse effects were observed except for a decrease in the mucosal wave of one patient, after injection into a superficial area of the vocal fold.

Conclusion: Based on the preliminary results of this trial, PAAG appears to be a long‐lasting and safe injection material that is suitable for the treatment of glottal insufficiency caused by permanent unilateral vocal cord paralysis.
The Variant Type of Preauricular Sinus: Postauricular Sinus
Authors: Choi Seong Jun , Choung Yun‐Hoon , Park Keehyun , Bae Junho , Park Hun Yi
Published: February 2009

Objective: Preauricular sinuses (PAS) are common congenital malformations that usually occur at the anterior margin of the ascending limb of the helix, but the positions of PAS and directions on the fistular tracts are rarely posterior to the external auditory canal (EAC), which presents as a postauricular swelling. We named these cases as the variant type of PAS (‘postauricular sinuses’), and compared their clinical manifestations with those of the classical type.

Study Design: A retrospective study.

Methods: We retrospectively reviewed the charts of patients who had undergone preauricular fistulectomy from 2002 to 2006. These patients were then categorized into two groups according to the position of the preauricular sinus sac. The classical group was defined as the group of patients with sacs located on the (superior) anterior to the EAC, and the variant group as those whose sacs are located on the posterior site of the EAC. We analyzed the incidence, previous histories, clinical manifestations, recurrence rates, and surgical techniques of the variant type of preauricular sinuses and compared them with those of the classical type.

Results: Eleven (10.9%) of 101 patients were diagnosed with preauricular sinuses of the variant type. The male to female ratios of the classical and the variant groups were 44:46 and 7:4, respectively. The average age of the patients was approximately 11 to 13 years in both groups. All variant types of preauricular sinuses showed preauricular pits located posterior to the imaginary line that connects the tragus with the posterior margin of the ascending limb of the helix, unlike the classical type. Most (72.8%) of the fistular tracts of the variant type were directed in the posterior‐middle direction from the pits. The variant types were operated with a dual approach using preauricular and retroauricular incisions, unlike the classical type, and the recurrence rate was 0% (compared with 2.2% in the classical type).

Conclusion: Frequent postauricular infected swellings may indicate the presence of the variant type of preauricular sinuses. The variant type of preauricular sinuses presenting in the postauricular area were found to have an unusual location of the fistula pit that was positioned posterior to the imaginary tragal extended line. A comprehensive physical examination of the preauricular pits should be performed to avoid incomplete excision of the variant types.
Effect of Ototopical Medications on Tympanostomy Tube Biofilms
Authors: Oxley K Scott , Thomas John G. , Ramadan Hassan H.
Published: February 2009

Objective: Examine how ototopical medications affect biofilms on fluoroplastic tympanostomy tubes.

Study Design: In vitro comparison of different ototopical medications against a clinical isolate of Pseudomonas aeruginosa biofilm on tympanostomy tubes treated for 5, 10, 14, and 21 days.

Methods: Under sterile conditions 21 tympanostomy tubes were cut in half. These were attached to pegs of two Calgary Biofilm Devices via rubber cement. Device 1 evaluated microbial growth as colony forming units (CFUs). Device 2 evaluated presence of biofilms. Tubes were prepped for biofilm growth, incubated, and stressed for 72 hours. Afterward, one tube per device was removed and forcefully washed. One was sonificated for 5 minutes, serially diluted, and plated for CFUs. Formalin preserved the other for biofilm evaluation by scanning electron microscopy. Next, tubes were exposed to five drops of Ciprofloxacin, Ciprofloxacin/Dexamethasone, Dexamethasone, Ofloxacin, or saline for 1 hour. Afterward, the ototopicals were removed and sterile broth was placed in the wells as a nutrient. This was repeated every 12 hours for 5, 10, 14, and 21 days of treatment. Prior to the last dose of treatment intervals, a streak plate was performed to evaluate for microbial growth in the wells. The tubes were evaluated for CFUs and biofilms at each interval as previously described.

Results: Microbial activity in CFUs decreased by day 5 and continued through day 21 for the antibiotic containing drops. Despite treatment, the biofilm was never eradicated and continued to progress.

Conclusions: Infectivity of the biofilm is neutralized by antibiotic ototopicals; however, the biofilm will progress despite treatment.