bluuebunny/crossref_metadata_2025_split huggingface dataset:
Comprehensive Algorithm for Skull Base Dural Lesion and Cerebrospinal Fluid Fistula Diagnosis
Authors: Meco Cem , Oberascher Gerhard 
Published: May 2004

AbstractObjectives/Hypothesis: Skull base dural lesions and cerebrospinal fluid (CSF) fistulas are potentially vital conditions whose diagnosis can be challenging. The authors' aim was to compose a comprehensive algorithm that combines the most modern diagnostic tools in easily applicable patterns to indicate a possible dural lesion or CSF fistula.Study Design: Prospective clinical study.Methods: The authors collected the data of all patients with suspicion of CSF fistula or dural lesion, or both, between January 1999 and December 2002. Beta–trace protein, β2‐transferrin, and endoscopic and laboratory sodium fluorescein tests; high‐resolution computed tomography; and magnetic resonance cisternography were used according to the symptoms and etiological factors. The results of the diagnostic tools that were used and intraoperative findings (in case of an operative treatment) were reviewed.Results: From 1999 to 2002, 236 patients were evaluated because of suspicion of dural lesion or CSF fistula, mostly after head trauma. Pattern I of the algorithm was applied for head trauma in dural lesion or CSF leak assessment, pattern II for postoperative CSF leaks, pattern III for evaluation of spontaneous CSF rhinorrhea, and pattern IV for the assessment of recurrent pneumococcal meningitis related to dural lesions without CSF fistula. By applying the patterns of this algorithm, a dural lesion or CSF leak that was also confirmed intraoperatively was detected in 48 patients.Conclusion: The four patterns of the new diagnostic algorithm described in the present study enable physicians to reliably clarify suspicions of dural lesions and CSF fistulas and aim to help them choose the best possible management. Each pattern uses the optimal combination of CSF tests and radiological imaging to reach a synergistic effect for precisely detecting dural lesions or CSF fistulas. Accordingly, this improves surgical decision‐making when necessary.
A Numerical Simulation of Intranasal Air Temperature During Inspiration
Authors: Lindemann Joerg , Keck Tilman , Wiesmiller Kerstin , Sander Bjoern , Brambs Hans‐Juergen , Rettinger Gerhard , Pless Daniela 
Published: May 2004

AbstractObjectives/Hypothesis: In vivo measurements of the intranasal air temperature are feasible. The present study was designed to reproduce temperature distributions within the human nasal cavity by means of numerical simulation.Study Design: Numerical simulation.Methods: Based on computed tomography (CT), a steady‐state computational fluid dynamics (CFD) simulation was performed displaying the temperature distribution throughout the human nasal cavity during inspiration. The results of the numerical simulation were compared with in vivo temperature measurements.Results: The numerical simulation demonstrated that the major increase of the inspiratory air temperature can be found in the anterior nasal segment, especially within the nasal valve area, which is comparable to in vivo measurements. Intranasal areas of high temperature were characterized by turbulent airflow with vortices of low velocity. The results of numerical simulation showed an excellent comparability to the results of previous in vivo measurements in the entire nasal cavity.Conclusion: The anterior nasal segment is the most effective part of the nose in heating of the ambient air. The findings demonstrated the complexity of the relationship between airflow patterns and heating of inspired air. A numerical simulation of the temperature distribution using CFD is practicable.
The Effect of β‐Blocker Premedication on the Surgical Field During Endoscopic Sinus Surgery
Authors: Nair Salil , Collins Melanie , Hung Patrick , Rees Guy , Close David , Wormald Peter‐John 
Published: May 2004

AbstractObjectives/Hypothesis: A number of previous studies have tried to assess the effects of hypotension on the surgical field during endoscopic sinus surgery. These studies have been limited by inadequate sample sizes, lack of a control group, and limited data collection. The aim of the present study was to determine whether the routine use of β‐blockers as a pre‐medication could improve the operative field in endoscopic sinus surgery.Study Design: A prospective, randomized, double‐blinded, placebo‐controlled trial.Methods: Eighty patients undergoing endoscopic sinus surgery who fit the inclusion and exclusion criteria were randomly assigned to receive either a β‐blocker, Metoprolol (group 1), or a placebo tablet (group 2) 30 minutes before surgery. A standard anesthetic protocol was followed. At the commencement of surgery and at regular 15‐minute intervals the surgical field, blood loss, heart rate, blood pressure, and isoflurane concentration were assessed.Results: There was a significant difference in overall mean heart rate between the placebo and β‐blocker groups (P < .0001). In the entire group, surgical grade correlated with heart rate (r = 0.36, P < .05) but not with mean arterial blood pressure. Mean surgical grade was similar between the placebo and β‐blocker groups, but early in the study a significantly better surgical field was recorded in the β‐blocker group (P < .001). Surgical grade was significantly better in those with a mean heart rate of less than 60 beats per minute (P < .02).Conclusion: Although “optimum” conditions were present in the patients receiving β‐blocker, the authors thought that the grading system was not discriminating enough to demonstrate a significant difference between the groups. The crucial finding in the study was the correlation between heart rate and surgical grade in the entire group. During endoscopic sinus surgery surgery, anesthetic manipulations should be directed at maintaining a low heart rate.
Upper Airway and Its Surrounding Structures in Obese and Nonobese Patients With Sleep‐Disordered Breathing
Authors: Liao Yu‐Fang , Chuang Ming‐Lung , Huang Chiung‐Shing , Tsai Ya‐Yu 
Published: May 2004

AbstractObjectives/Hypothesis: The objective was to understand the pathophysiological relationship between obesity and sleep‐disordered breathing by using cephalometry with the Muller maneuver.Study Design: A prospective study.Methods: One hundred habitually snoring men were evaluated for sleep‐disordered breathing at the Sleep Center of Chang Gung Memorial Hospital (Taipei, Taiwan). Each subject received overnight polysomnography and two lateral cephalograms at the end‐expiration phase (L1) and the Muller maneuver (L2), respectively, to evaluate the facial skeleton and the upper airway and its surrounding structures (soft palate, tongue, epiglottis, and hyoid bone). After excluding 14 patients from the study because of jaw opening during cephalometry, 86 (39 nonobese and 47 obese) patients with sleep‐disordered breathing were enrolled.Results: Patients with varying degrees of obesity significantly differed in terms of the facial skeleton and the structure and function of the upper airway and its surrounding structures. The Muller maneuver caused dynamic changes in the hypopharyngeal airway and position of the tongue, and these dynamic changes were related to the pathogenesis of sleep‐disordered breathing for the two groups (nonobese and obese patients). The regression model generated for the nonobese group revealed that the apnea hypopnea index was significantly related to the pharyngeal length (L2) and the soft palate thickness (L1). In contrast, the regression model generated for the obese group revealed that the apnea hypopnea index was significantly related to the soft palate (length [L1] and dynamic position change), the hyoid position (vertical [L1] and horizontal [L2]), the tongue (dynamic position change), and body mass index.Conclusion: Cephalometry with the Muller maneuver may provide further insight into the pathogenesis of sleep‐disordered breathing for the two groups of patients (nonobese and obese patients).
Different Risk Factors in Basaloid and Common Squamous Head and Neck Cancer
Authors: Kleist Britta , Bankau Alexander , Lorenz Gerd , Jäger Bernd , Poetsch Micaela 
Published: May 2004

AbstractObjectives/Hypothesis: The prevalence of human papillomavirus (HPV), herpes simplex virus (HSV), cigarette smoking and alcohol abuse was compared between two histological subgroups of head and neck cancer.Study Design: Retrospective review.Methods: Paraffin‐embedded, histologically confirmed surgical specimens from the oropharynx, hypopharynx and larynx, comprising 67 conventional squamous cell carcinomas (SCC) and 10 basaloid squamous cell carcinomas (BSCC), were analyzed for the presence of HPV and HSV DNA using polymerase chain reaction (PCR) techniques. The PCR products were verified by direct sequencing. Patient charts were reviewed for clinical data and risk factors.Results: Given an overall HPV DNA detection rate of 32.5%, a basaloid morphology of the carcinomas correlated significantly with occurrence of HPV DNA (P = .0001). An association could also be demonstrated between basaloid appearance and evidence of HSV DNA (single and combined with HPV DNA; P = .014 and 0.0429, respectively), even if this result based on a low overall HSV DNA detection rate (6.5%). Demonstration of viral DNA in the BSCC specimens was not related to tobacco or alcohol consumption. In contrast, cigarette smoking proved as significant characteristic of SCC (P = .0087). Alcohol abuse occurred also predominately in patients with SCC, but without statistical significance.Conclusion: These results hint at differences in the etiology of two distinct histological entities of head and neck cancer. Further research in this field could complete these preliminary data and provide the background for specific preventive strategies.
Deafness Due to A1555G Mitochondrial Mutation Without Use of Aminoglycoside
Authors: Matsunaga Tatsuo , Kumanomido Hiroshi , Shiroma Masae , Ohtsuka Akihiro , Asamura Kenji , Usami Shin‐ichi 
Published: May 2004

AbstractObjectives/Hypothesis: The objective was to clarify the characteristics of deafness associated with the A1555G mutation within mitochondrial 12S ribosomal RNA gene in the absence of aminoglycoside exposure.Study Design: Clinical and genetic studies in family members with the A1555G mitochondrial mutation were performed.Methods: The subjects were 123 maternally related members of a large Japanese family with the A1555G mutation. All subjects had no previous history of exposure to aminoglycosides. Hearing disability and handicap, tinnitus, and medical histories were analyzed by interviews in all of the subjects, genetic testing was performed in 41 subjects, and pure‐tone audiometry was conducted in 26 subjects with hearing disability and handicap.Results: The A1555G mutation was detected in a homoplasmic form (meaning that all the mitochondrial DNA carries the mutation) in all 41 subjects who were screened. The risk for developing postlingual hearing loss was likely to be much higher in the present subjects than in the general population. Both the severity and age at onset of the phenotype were similar in affected subjects within the same sibling group. Pure‐tone averages were significantly worse in subjects who developed hearing loss before age 10 years than in those who developed hearing loss later.Conclusion: The present study demonstrated that the prevalence of deafness in individuals with the A1555G mitochondrial mutation was likely to be high even in the absence of aminoglycoside exposure and clearly showed the association of severe to profound hearing loss with the onset of hearing loss before age 10 years.
Objective Outcome After Functional Endoscopic Sinus Surgery: Prediction Factors
Authors: Watelet J. B. , Annicq B. , Van Cauwenberge P. , Bachert C. 
Published: May 2004

AbstractObjectives/Hypothesis: After failure of medical treatment, chronic rhinosinusitis and nasal polyposis require surgical management. However, little is known about the predictive factors for objective outcome after sinus surgery. The aims of the study were to correlate preoperative, intraoperative, and postoperative clinical factors to healing outcome and to establish their respective predictive values.Study Design: Prospective study.Methods: Eighteen patients who had surgery for chronic rhinosinusitis and 18 who had surgery for nasal polyposis at the Ghent University Hospital (Ghent, Belgium) were followed for a 6‐month period. In all, 76 operated sides were independently considered. The healing quality was evaluated by endoscopy weekly and then monthly for a period of 6 months. A logistic regression analysis with healing quality at month 6 as outcome was performed on preoperative, intraoperative, and postoperative factors.Results: Previous sinus surgery (P = .0006) and initial disease (P = .0430) were found to be highly predictive for the healing outcome at month 6, patients with nasal polyposis or previous surgery showing significantly worse objective outcome (P = .0034 and P < .0001, respectively). The preoperative computed tomography scan had no predictive value with respect to the extent of surgery (P = .0281). Postoperative parameters had less predictive value.Conclusion: Initial disease and its severity as reflected by the extent of surgery and surgical antecedents were the best predictors for the objective outcome at 6 months after sinus surgery. Whereas the first postoperative phase showed similar characteristics for all patients, the healing course differed between patients from month 1 to the end point.
Mood Improvement after Surgery for Obstructive Sleep Apnea
Authors: Li Hsueh‐Yu , Huang Yu‐Shu , Chen Ning‐Hung , Fang Tung‐Jen , Liu Chia‐Yih , Wang Pa‐Chun 
Published: May 2004

AbstractObjective: Patients with obstructive sleep apnea (OSA) may experience unfavorable psychologic symptoms such as depression and anxiety. The aim of this study was to confirm this hypothesis and to investigate whether the psychologic symptoms among OSA patients can be relieved by surgical intervention.Study Design: Prospective, longitudinal intervention study.Methods: The 5‐Item Mental Health scale (MH‐5) was used to evaluate the postoperative changes of mood after extended uvulopalatal flap (EUPF) surgery on 84 Taiwanese patients with OSA. The preoperative and postoperative MH‐5 data obtained from these patients were compared with a Taiwanese population norm.Results: Before surgery, the MH‐5 scores of the OSA patients were significantly worse than the Taiwanese population norm of 72.8 (P < .0001). Postoperatively, mean MH‐5 scores significantly increased from 61.8 ± 16.0 to 70.0 ± 15.8 (P = .0006). The effect size of this score change was 0.51, indicating a moderate degree of mood improvement. However, this score was still inferior to that of the population norm (P = .0045). The mood improvement was not significantly associated with the changes in either sleep apnea events or the level of sleepiness. Neither the changes in respiratory disturbance index (P = .4382), maximum arterial oxygen saturation (P = .4866), nor the change in Epworth Sleepiness Scale scores (P = .4951) were predictive of the MH‐5 score improvement (R2 = 0.07).Conclusions: This study demonstrated that patients with OSA had a higher level of anxiety, depression, and probable behavior or personality changes than the population norm. EUPF surgery could significantly improve the mood status among OSA patients; the effect of surgery was mild but clinically relevant. However, the extent of mood improvement experienced by OSA patients receiving operations may not simply be attributable to the changes in sleep apnea events or a reduced level of sleepiness.
Nerve‐Muscle Transplantation to the Paraglottic Space after Resection of Recurrent Laryngeal Nerve
Authors: Tanaka Shinzo , Asato Ryo , Hiratsuka Yasuyuki 
Published: May 2004

AbstractObjective: To evaluate a new method of nerve‐muscle transplantation (NMT) to the paraglottic space after resection of the recurrent laryngeal nerve (RLN) during surgery for thyroid cancer.Design: Review of nine consecutive patients with RLN paralysis caused by the thyroid cancer before surgery.Method: After the usual extirpation of the thyroid cancer with concomitant removal of the RLN, the lower part of the sternohyoid muscle approximately 1 cm in width and 2 cm in length with the ansa cervicalis nerve connected was inserted into the paraglottic space by way of anterior retraction of the thyroid ala with the inferior horn cut off. When the muscle or the nerve was adhesive to the cancer, the nerve‐muscle on the opposite side was used with transfer through the space under the thyrohyoid muscles and the superior horn of thyroid ala.Results: The voice quality was good or fair after surgery. In most patients, the maximum phonation time was 10 seconds or longer, and the mean flow rate was lower than 200 mL/s. The vocal functions were good immediately after surgery and maintained good values for 2 years or more after surgery. Vocal fold atrophy was not found in any patient.Conclusion: When the RLN is resected during surgery for thyroid cancer end‐to‐end anastomosis of the nerve is impossible, NMT to the paraglottic space is a useful method for preserving good voice and preventing atrophy of the vocal fold.
The ultrastructure of the spermatozoon of the lizardIguana iguana(Reptilia, Squamata, Iguanidae) and the variability of sperm morphology among iguanian lizards
Authors: Vieira Gustavo H. C. , Colli Guarino R. , Báo Sônia N. 
Published: May 2004

AbstractThe spermatozoon ofIguana iguanais filiform and resembles that of other iguanian lizards, being most similar toTropidurus. All sperm synapomorphies of Tetrapoda, Amniota and Squamata are present in the sperm ofIguana iguana. By reconstructing the evolution of 30 sperm characters we identified a novel synapomorphy of Iguania: the presence of a well‐developed acrosomal ridge at the level of the epinuclear lucent zone. Because of the poor topological resolution among iguanian clades we could not discount the possibility of convergence or neutral selection as determinant of the variability in characteristics of the sperm cell. In agreement with previous studies, we identified heterogeneous rates of evolution among the three main regions of the sperm cell, namely the head, midpiece and tail.
Constructive and Classical Models for Results in Economics and Game Theory
Authors: Prasad Kislaya 
Published: May 2004

ABSTRACTA standard approach in economic theory is to use a formal language to prove results about an economy or a game. In this paper, model theory is used to examine interpretations of such results. The particular focus is on constructive theorems, since results established by constructive methods are valid for many different interpretations, whereas classical theorems are valid more narrowly. I discuss why non‐classical models may be of interest and also describe applications of model theory to economics in classical contexts, e.g. non‐standard analysis. The paper advocates a viewpoint suggesting that constructive models are tools for studying worlds in which agents’ knowledge of the world is incomplete.
Production of Ideas by Means of Ideas: A Turing Machine Metaphor
Authors: Zambelli Stefano 
Published: May 2004

ABSTRACTIn this paper production of knowledge is modelled in terms of Turing machines or compositions of Turing machines. The input tape and the output tape of the machines are seen as the encoding of ideas generated by Turing machines. This allows us, among other things, to define and measure the complexity of ideas and knowledge in the simple terms of algorithmic and computational complexity. Moreover the very existence of the halting problem allows for the introduction of a non‐stochastic notion of uncertainty. Consequently uncertainty may be modelled not as the outcome of a predefined probability distribution, but in terms of the randomness associated with the halting problem. In this way the ‘frequency distribution of innovations’ is endogenously generated by the choices of the Turing machines. It is shown that a vast variety of alternative dynamic behaviours in knowledge evolution and hence in productivity can be generated. One can observe clusters of emerging innovations, persistent and increasing emergence of new discoveries as well as periods of explosive evolutions followed by stasis periods.
Induction: From Kolmogorov and Solomonoff to De Finetti and Back to Kolmogorov
Authors: McCall John J. 
Published: May 2004

ABSTRACTThis paper compares the solutions to “the induction problem” by Kolmogorov, de Finetti, and Solomonoff. Brief sketches of the intellectual history of de Finetti and Kolmogorov are also composed. Kolmogorov's contributions to information theory culminated in his notion of algorithmic complexity. The development of algorithmic complexity was inspired by information theory and randomness. Kolmogorov's best‐known contribution was the axiomatization of probability in 1933. Its influence on probability and statistics was swift, dramatic, and fundamental. However, Kolmogorov was not satisfied by his treatment of the frequency aspect of his creation. This in time gave rise to Kolmogorov complexity. De Finetti, on the other hand, had a profound vision early in his life which was encapsulated in his exchangeability theorem. This insight simultaneously resolved a fundamental philosophical conundrum—Hume's problem, and provided the bricks and mortar for de Finetti's constructive probabilistic theory. Most of his subsequent research involved extensions of his representation theorem. De Finetti was against determinism and celebrated quantum theory, while Kolmogorov was convinced that in every seemingly indeterministic manifestation there lurked a hidden deterministic mechanism. Solomonoff introduced algorithmic complexity independently of Kolmogorov and Chaitin. Solomonoff's motivation was firmly focused on induction. His interest in induction was to a marked extent sparked by Keynes’ 1921 seminal book. This interest in induction has never faltered, remaining prominent in his most recent research. The decisive connection between de Finetti and Kolmogorov was their lifelong interest in the frequency aspect of induction. Kolmogorov's solution to the problem was algorithmic complexity. De Finetti's solution to his frequency problem occurred early in his career with the discovery of the representation theorem. In this paper, we try to explain these solutions and mention related topics which captured the interest of these giants.
Economic Dynamics and Computation—Resurrecting the Icarus Tradition
Authors: Velupillai K. Vela 
Published: May 2004

ABSTRACTComputation over the reals, without abandoning the paradigm of the digital computer, raises difficult issues at the interface between recursion theory, numerical analysis and dynamical systems. In this paper an attempt is made to provide economic and mathematical justifications for returning to the analogue computing traditions that were once felicitously practised in economics.
An Essay in λ‐Calculus
Authors: Pasquali Corrado 
Published: May 2004

ABSTRACTThis paper aims at presenting λ‐calculus and at suggesting how and why its abstractions set can be fruitfully used as a tool for representing entities populating the economic realm and how it can be conceived of as a language which is well suited to capturing some basic facts and features pertaining to complex organizational dynamics. I will present and discuss some of Walter Fontana's ideas on which this paper is largely grounded. The backbone and main idea of this essay is that λ‐calculus offers us the chance of adopting a precisely defined syntactical—as opposed to quantitative—mind‐set in representing the entities which populate a scientific theory. In particular, I shall try to illustrate the idea that syntax can be conceived of as an abstract theory of objects’ behavior when objects themselves are not represented solely in terms of their quantitative properties but as carriers of specific structure–action relationships and of construction possibilities.