bluuebunny/crossref_metadata_2025 huggingface dataset:
Madrid as a tourist destination: analysis and modelization of inbound tourism
Authors: Garín‐Muñoz Teresa
Published: July 2004

This paper presents a model for explaining the international tourism flows to Madrid. The study is based primarily on examining the main characteristics of inbound tourism flows to Madrid in terms of its structure, evolution and composition by countries of origin of the visitors. According to the general principles of economic theory and the classic literature on tourism demand, a description of the main factors to be considered in determining tourism flows is presented. In the second part of the paper, by using data corresponding to 25 countries of origin and 16 years (1985–2000), an econometric (panel data) model is used to estimate the quantitative relationship between the level of inbound tourism to Madrid and its determinants. The model selected has been subject to a battery of diagnostics in order to test the validity of the assumptions that underlie the estimation. By using the Im–Pesaran–Shin test for unit roots the null hypothesis of non‐stationarity of residuals is rejected and it is concluded that the model can be used for inference. The results show that income of the countries of origin of the travellers and costs of living of the tourists in Madrid relative to the costs of living in the origin country were among the most important factors of the international tourism demand. An interpretation of the results in terms of elasticities is presented in the last part of the paper, as well as their implications for tourism policy. Copyright © 2004 John Wiley & Sons, Ltd.
Sway patterns in a case of orthostatic tremor responsive to alcohol
Authors: Bacsi Ann M. , Halmagyi G. Michael , Colebatch James G.
Published: July 2004

We describe changes in the extent of sway in a man with orthostatic tremor (OT) who reported increased stability after alcohol. He was tested at baseline and again after 40 g (0.5 g/kg) of alcohol. These results were compared to those of 3 age‐matched controls (no alcohol). The patient's baseline sway was greater than controls, larger in the lateral than the anteroposterior plane, but retained normal responsiveness to the use of external support, increasing stance width, and vision. Tremor frequency significantly decreased after alcohol, as did low‐ and high‐frequency tremor amplitude and the extent of body sway. Despite these findings, sway remained greater than controls. OT thus may show functionally important alcohol responsiveness. © 2004 Movement Disorder Society
Effect of stimulation frequency on tremor suppression in essential tremor
Authors: Ushe Mwiza , Mink Jonathan W. , Revilla Fredy J. , Wernle Angie , Schneider Gibson Patricia , McGee‐Minnich Lori , Hong Minna , Rich Keith M. , Lyons Kelly E. , Pahwa Rajesh , Perlmutter Joel S.
Published: July 2004

We sought to determine the effect of deep brain stimulation (DBS) frequency on tremor suppression in essential tremor (ET) patients with deep brain stimulators implanted in the ventral intermediate nucleus (VIM) of the thalamus. A uniaxial accelerometer was used to measure tremor in the right upper extremity of subjects with a diagnosis of ET who had DBS electrodes implanted in the left VIM. The root‐mean‐square acceleration was used as the index of tremor magnitude and normalized to the OFF DBS condition. There was a highly significant inverse sigmoidal relationship between stimulation frequency and normalized tremor acceleration (X2/DoF = 0.42, r2 = 0.997). Tremor acceleration had a nearly linear response to stimulation frequencies between 45 and 100 Hz with little additional benefit above 100 Hz. These findings have two important implications. Clinically, frequency of thalamic stimulation is an important variable for optimal tremor control with maximal benefit achieved with 100 to 130 Hz in most patients. Second, thalamic DBS provides tremor benefit in a graded manner and is not an all‐or‐nothing phenomenon. © 2004 Movement Disorder Society
Distribution, type, and origin of Parkin mutations: Review and case studies
Authors: Hedrich Katja , Eskelson Cordula , Wilmot Beth , Marder Karen , Harris Juliette , Garrels Jennifer , Meija‐Santana Helen , Vieregge Peter , Jacobs Helfried , Bressman Susan B. , Lang Anthony E. , Kann Martin , Abbruzzese Giovanni , Martinelli Paolo , Schwinger Eberhard , Ozelius Laurie J. , Pramstaller Peter P. , Klein Christine , Kramer Patricia
Published: July 2004

Early‐onset Parkinson's disease (PD) has been associated with different mutations in the Parkin gene (PARK2). To study distribution and type of Parkin mutations, we carried out a comprehensive literature review that demonstrated two prominent types of mutations among 379 unrelated mutation carriers: exon rearrangements involving exon 3, 4, or both, and alterations in exons 2 and 7, suggesting mutational hot spots or founders. To elucidate the origin of 14 recurrent Parkin mutations in our samples, we carried out a detailed haplotype analysis at the PARK2 locus. Thirty‐eight mutation‐positive individuals, available family members, and 62 mutation‐negative individuals were genotyped. We determined allele frequencies and linkage disequilibrium (LD) to evaluate the significance of shared haplotypes. We observed no LD between markers at PARK2. Our data support a common founder for the most frequent Parkin point mutation (924C>T; exon 7) and indicate a mutational hot spot as cause of a common small deletion (255/256delA; exon 2). Furthermore, the most frequent Parkin exon deletion (Ex4del) arose independently in 2 of our subjects. However, it also occurred as the result of a founder mutation in 2 cases that shared identical deletion break points. This study provides evidence for both mutational hot spots and founder mutations as a source of recurrent mutations in Parkin, regardless of the mutation type. © 2004 Movement Disorder Society
Effects of rivastigmine on motor and cognitive impairment in Huntington's disease
Authors: de Tommaso Marina , Specchio Nicola , Sciruicchio Vittorio , Difruscolo Olimpia , Specchio Luigi Maria
Published: July 2004

To evaluate the efficacy of rivastigmine on motor and cognitive impairment in Huntington's disease (HD), we carried out a prospective, open‐label, randomized, controlled study. Twenty‐one HD patients were enrolled: 14 were randomly sorted into medication and 7 to no‐treatment groups. Clinical and demographic features were similar between groups. After 8 months, an efficacy evaluation was carried out to compare the two groups. The improvement of cholinergic transmission in HD patients seemed to have a slight effect in ameliorating cognitive performance and slowing motor deterioration. © 2004 Movement Disorder Society
TSGen: a tool for modeling of frame loss in streaming video
Authors: Shahbazian John , Christensen Kenneth J.
Published: July 2004

Packet loss affects the quality of streaming video. We describe a new Time Series Generator (TSGen) tool to generate a time series that models video packet loss phenomena by capturing both the moment and autocorrelation signatures of frame loss in a video stream. Copyright © 2004 John Wiley & Sons, Ltd.
Database‐independent, database‐dependent, and extended interpretation of peptide mass spectra in VEMS V2.0
Authors: Matthiesen Rune , Bunkenborg Jakob , Stensballe Allan , Jensen Ole N. , Welinder Karen G. , Bauw Guy
Published: July 2004

The Virtual Expert Mass Spectrometrist (VEMS) program package was developed for flexible, automated, and manual de novo tandem mass spectrometry (MS/MS) protein sequencing, and includes accessory programs for matrix‐assisted laser desorption/ionization‐mass spectrometry (MS) interpretation, and generation of protein and peptide databases. VEMS V2.0 has been developed into a fast tool for combining database‐independent and ‐dependent protein assignments in an extended analysis of MS/MS‐peptide data. MS or MS/MS data can be directly recalibrated after the first search by fitting the data to the best search result using polynomial equations. The score function is an improvement of known scoring algorithms and can be adapted for any MS instrument type. In addition, VEMS offers a novel statistical model for evaluating the significance of the protein assignment. The novel features are illustrated by the analysis of the fragmentation spectra obtained by liquid chromatrography‐MS/MS analysis of peptides from an anionic peroxidase enriched protein fraction from potato root tissue. The extended analysis mode resulted in the additional assignment of spectra for nine modified tryptic peptides and nine miscleaved peptides, in addition to the 45 spectra from regular tryptic peptides. Of the nine modified peptides, three were glycosylated.
Proteomic signature of human cancer cells
Authors: Seike Masahiro , Kondo Tadashi , Fujii Kazuyasu , Yamada Tesshi , Gemma Akihiko , Kudoh Shoji , Hirohashi Setsuo
Published: July 2004

We assessed proteomic profiles as biomarkers for monitoring cell phenotypes. Protein expression profiles were obtained by fluorescence two‐dimensional difference gel electrophoresis (2‐D‐DIGE), in which quantitative ability is improved by labeling proteins with fluorescent dyes prior to electrophoresis. Integrated protein spot intensities were analyzed by a statistical approach. The proteomic data of two groups of cell lines: (1) adenocarcinoma (AC) cell lines derived from lung, pancreas and colon tissues and (2) lung cancer cell lines with different histological backgrounds, including AC, squamous cell carcinoma and small cell carcinoma, were assessed on the basis of prior biological information. Hierarchical clustering analysis and principal component analysis were used to divide the cell lines into subgroups on the basis of similarities between their protein expression profiles. The majority of cell lines were grouped according to their organ of origin or histological background. A machine‐learning algorithm selected 32 protein spots that were responsible for the classification. The results indicate that proteomic data generated by 2‐D‐DIGE can provide a signature of essential cell phenotypes, suggesting that it might be possible to apply this technique to developing tumor markers that could identify the organ of origin of metastatic tumors and contribute to the differential diagnosis of lung cancer.
Towards data management of the HUPO Human Brain Proteome Project pilot phase
Authors: Blüggel Martin , Bailey Sonja , Körting Gerhard , Stephan Christian , Reidegeld Kai A. , Thiele Herbert , Apweiler Rolf , Hamacher Michael , Meyer Helmut E.
Published: July 2004

The pilot phase of the Human Brain Proteome Project as a part of the Human Proteome Organisation has just been started. In two pilot studies, 18 different laboratories are analyzing mouse brains of three age stages and human brain autopsy versus biopsy material, respectively. The overall aim is to elucidate the portfolio of available techniques as well as to elaborate common standards. As a first step, it was decided to use the common bioinformatics platform ProteinScape™ that was introduced to the participating groups in a two day course in Bochum, Germany.
Synthesis and inhibition performance of a polymer‐supported inhibitor
Authors: Yang Peng , Sun Yufeng , Deng Jianyuan , Liu Weina , Zhang Li , Yang Wantai
Published: July 2004

The synthesis of a polymer‐supported inhibitor (PSI) and its inhibition performance for free‐radical polymerization are reported for the first time. A special method has been devised to synthesize PSI with pure and abundant hydroquinone (HQ) groups anchored onto the polymer surface. A thin HQ/acetone (AC) solution is sandwiched between two polymer films. Under ultraviolet irradiation, AC as an photoinitiator quickly and effectively grafts HQ onto the polymer surface. PSI has been characterized with ultraviolet–visible and attenuated total reflectance/Fourier transform infrared spectroscopy. For potential applications, PSI has been used to inhibit the thermal polymerization of styrene and methyl methacrylate. The corresponding inhibition performance has been investigated through the measurement of the induction period with the dilatometer method. With the same absolute amount, the maximum inhibition ability of PSI approaches half that of a free inhibitor. Increasing the dispersion degree of PSI is favorable for the enhancement of the inhibition ability. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 4074–4083, 2004
The discovery of metallocene catalysts and their present state of the art
Authors: Kaminsky Walter
Published: July 2004

Metallocene and other transition metal complexes activated by methylaluminoxane are highly active catalysts for the polymerization of olefins, diolefins, and styrene, which was discovered at the University of Hamburg about 25 years ago. These catalysts allow the synthesis of polymers with a highly defined microstructure, tacticity, and stereoregularity, as well as new copolymers with superior properties such as film clarity, tensile strength, and lower extractables. A better understanding of the mechanism of olefin polymerization leads to findings of other new single site catalysts. The development of the metallocene/MAO‐catalysts from their discovery to their present state of the art is presented. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 3911–3921, 2004
Structural, electronic and optical calculations of Cu(In,Ga)Se2 ternary chalcopyrites
Authors: Belhadj M. , Tadjer A. , Abbar B. , Bousahla Z. , Bouhafs B. , Aourag H.
Published: July 2004

In this work, we have investigated the structural, electronic and optical properties of the ternary I–III–VI2 chalcopyrite semiconductors ABX2 (A = Cu, B = In, Ga, X = Se) by means of a first‐principles density‐functional total‐energy calculation with the local‐density approximation (LDA), using the all‐electron full‐potential linear‐augmented plane‐wave method (FP‐LAPW). The equilibrium lattice constants and the bulk moduli (a, c, c/a, u and B0) are compared with other theoretical calculations. The energy gap at ambient pressure is found to be direct and the nature of the gap crucially depends on the manner in which the d electrons of the A atoms are treated. We have also reported the optical properties of two chalcopyrite semiconductors CuInSe2 and CuGaSe2. Results on complex dielectric functions, refractive indices n, extinction coefficients k, and normal‐incidence reflectivity R in the two crystals are given and compared with earlier data where available. We analyze in detail the structures of the dielectric function observed in the studied energy region. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
On the pressure (volume) dependence of Grüneisen parameter, Debye temperature and thermal expansivity in ε‐Fe
Authors: Liu Quan , Chen Li‐rong
Published: July 2004

Assuming the second Grüneisen parameter q has the form of q(T, P) = q(T, 0) (V(T, P)/V(T, 0))n, the three calculated formulas of Grüneisen parameter; Debye temperature and thermal expansivity of ε‐Fe are presented. The calculated results show that the agreement with the experimental data is good. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Group theoretical description of two‐electron wave functions in systems with subgroups of symmetry
Authors: Yarzhemsky V. G. , Nefedov V. I.
Published: July 2004

A method for group theoretical description of two‐electron wave functions, based on the Mackey theorem on symmetrized squares, is developed. It is shown that the Mackey theorem makes it possible to construct basis functions and to label repeating representations. The technique is applied to molecules of Oh symmetry and to space groups with point groups D2h and D4h. Application of the results to high‐Tc superconductors is discussed. © 2004 Wiley Periodicals, Inc. Int J Quantum Chem, 2004
Development and validation of a prognostic model for survival time data: application to prognosis of HIV positive patients treated with antiretroviral therapy
Authors: May Margaret , Royston Patrick , Egger Matthias , Justice Amy C. , Sterne Jonathan AC ,   For the ART Cohort Collaboration
Published: July 2004

The process of developing and validating a prognostic model for survival time data has been much discussed in the literature. Assessment of the performance of candidate prognostic models on data other than that used to fit the models is essential for choosing a model that will generalize well to independent data. However, there remain difficulties in current methods of measuring the accuracy of predictions of prognostic models for censored survival time data. In this paper, flexible parametric models based on the Weibull, loglogistic and lognormal distributions with spline smoothing of the baseline log cumulative hazard function are used to fit a set of candidate prognostic models acrosskdata sets. The model that generalizes best to new data is chosen using a cross‐validation scheme which fits the model onk–1 data sets and tests the predictive accuracy on the omitted data set. The procedure is repeated, omitting each data set in turn. The quality of the predictions is measured using three different methods: two commonly proposed validation methods, Harrell's concordance statistic and the Brier statistic, and a novel method using deviance differences. The results show that the deviance statistic is able to discriminate between quite similar models and can be used to choose a prognostic model that generalizes well to new data. The methods are illustrated by using a model developed to predict progression to a new AIDS event or death in HIV‐1 positive patients starting antiretroviral therapy. Copyright © 2004 John Wiley & Sons, Ltd.
Methods for modelling change in cluster randomization trials
Authors: Klar Neil , Darlington Gerarda
Published: July 2004

Randomized trials are often designed to assess an intervention's ability to change patient knowledge, behaviour or health. The study outcome will then need to be measured at least twice for each subject—prior to random assignment and following implementation of the intervention. In this paper we consider methods for modelling change when data are obtained from cluster randomization trials where the unit of allocation is a family, school or community. Attention focuses on mixed effects linear regression extensions of (i) two‐sample t‐tests and (ii) analysis of covariance, in both cases accounting for dependencies among cluster members. Algebraic expressions for tests of the intervention effect are derived for the special case where there are a fixed number of subjects per cluster while simulation studies are used to compare the power of these procedures in the more realistic case where there is variability in cluster size. A key conclusion is that there can be considerable gains in power when allowing for different individual‐level and cluster‐level associations between the baseline and follow‐up assessments. The discussion is illustrated using data from a school‐based smoking prevention trial. Copyright © 2004 John Wiley & Sons, Ltd.
Ultrasound assessment of venous blood flow before and after laser therapy: approach to understanding the pathophysiology of twin–twin transfusion syndrome
Authors: Ishii K. , Chmait R. H. , Martínez J. M. , Nakata M. , Quintero R. A.
Published: July 2004

Objective

To estimate direction and volume of blood exchange between the donor twin and recipient twin by ultrasound assessment of blood flow in the umbilical vein before and after selective laser photocoagulation of communicating vessels (SLPCV) for twin–twin transfusion syndrome (TTTS).

Methods

Forty‐one TTTS patients underwent Doppler examination of the umbilical vein before and 24 h after SLPCV. The diameter and mean time‐averaged velocity of the umbilical vein were estimated. Total umbilical venous flow (TUVF) was calculated as follows: TUVF (mL/min) = mean time‐averaged velocity (cm/s) × mean cross‐sectional area (cm2) × 60 (s).

Results

TUVF was significantly higher in the recipient (111.2 mL/min) than in the donor twin (44.8 mL/min) before SLPCV (P < 0.0001). However, TUVF was no different between the recipient and the donor twin after SLPCV (93.1 vs. 70.7 mL/min, recipient and donor twin, respectively, P = 0.11). The donor twin's TUVF increased after surgery (P < 0.0001), while the recipient twin's TUVF decreased (P = 0.041). The median postoperative increase in the donor twin's TUVF of 25.9 mL/min had a corresponding decrease of TUVF in the recipient twin of 18.1 mL/min (P = 0.27).

Conclusions

Our data suggest that untreated TTTS is characterized by excessive umbilical venous blood flow in the recipient twin relative to the donor twin. Laser surgery results in concordant changes in umbilical venous flow in opposite directions between the donor and recipient twins, eliminating the initial imbalance. Our results lend support to the fundamental hypothesis of unbalanced blood flow exchange (net flow from donor to recipient) between monochorionic twins as the cause for TTTS and that laser surgery eliminates the pathophysiological cause. Copyright © 2004 ISUOG. Published by John Wiley & Sons, Ltd.
A fingerprint model for inhomogeneous ink–paper layer systems measured with micro‐x‐ray fluorescence analysis
Authors: Malzer Wolfgang , Hahn Oliver , Kanngiesser Birgit
Published: July 2004

Nowadays, micro‐x‐ray fluorescence analysis has become an established tool for the non‐destructive investigation of art objects. However, as these types of sample often forms complex and inhomogeneous layer systems, the quantitative evaluation of the measurements is far from a standard routine. In this paper a fingerprint model is described, which we developed to discriminate between different iron‐gall inks of historical manuscripts or compositions. Fundamental parameter methods are used to take self‐attenuation, interference from the paper background and diffusion of the ink into the paper into account. The capability of the method to contribute to the solution of archaeometric problems is exemplified by the investigation of an ancient composition. Finally, the restrictions of the model and possible improvements are discussed. Copyright © 2004 John Wiley & Sons, Ltd.
The use of combined trace element XRF and EDXRD data as a histopathology tool using a multivariate analysis approach in characterizing breast tissue
Authors: Farquharson M. J. , Geraki K.
Published: July 2004

The concentrations of K, Fe, Cu and Zn were measured in 77 breast tissue samples (38 classified as normal and 39 classified as diseased) using x‐ray fluorescence (XRF) techniques. The coherent scattering profiles were also measured using energy‐dispersive x‐ray diffraction (EDXRD), from which the proportions of adipose and fibrous tissue in the samples were estimated. The data from 30 normal samples and 30 diseased samples were used as a training set to construct two calibration models, one using a partial least‐squares (PLS) regression and one using a principal component analysis (PCA) for a soft independent modelling of class analogy (SIMCA) technique. The data from the remaining samples, eight normal and nine diseased, were presented to each model and predictions were made of the tissue characteristics. Three data groups were tested, XRF, EDXRD and a combination of both. The XRF data alone proved to be most unreliable indicator of disease state with both types of analysis. The EDXRD data were an improvement, but with both methods of modelling the ability to predict the tissue type most accurately was by using a combination of the data. Copyright © 2004 John Wiley & Sons, Ltd.
Superconducting tunnel junctions as detectors for high‐resolution x‐ray spectroscopy
Authors: Huber M. , Angloher G. , Hollerith C. , Ruedig A. , Jochum J. , Potzel W. , Feilitzsch F. v.
Published: July 2004

Superconducting tunnel junctions (STJs) are a type of cryogenic detector with a working temperature of about 100 mK. They allow the combination of low energy threshold, high quantum efficiency and good count rate capability with an excellent energy resolution; at an x‐ray energy of 5.9 keV an energy resolution of 10.8 eV (FWHM) has been achieved. The detector system described is based on STJs which consist of two superconducting Al electrodes separated by a thin dielectric tunnel barrier. The tunneling process of quasi‐particles created by deposition of energy in the electrodes leads to a detectable current signal. The STJ is equipped with a superconducting Pb absorber which is read out via phonons. The Pb absorber increases absorption efficiency (∼50% at 6 keV) and suppresses detector artefacts. The degeneration of Pb, most probably due to oxidation, is overcome by the introduction of a protective SiO layer on top of the absorber. This layer leads to a slight reduction of energy resolution. Nevertheless, a resolution of 9.7 eV at 1.7 keV and of ∼20 eV at 5.9 keV could be realized with a prototype detector. Currently this STJ‐based detector system is being incorporated into a prototype cryogenic spectrometer for XRF analysis. Copyright © 2004 John Wiley & Sons, Ltd.
Prognostic Factors for Early Gastric Cancer in France: Cox Regression Analysis of 332 Cases
Authors: Borie Frédéric , Rigau Valerie , Fingerhut Abe , Millat Bertrand ,   French Association for Surgical Research
Published: July 2004

Early gastric cancer (EGC) is defined as a lesion in which the depth of invasion is limited to the mucosa, submucosa, or both regardless of lymph node status; moreover, it has an excellent prognosis, with a 5‐year survival rate of more than 90%. We aimed to determine the prognostic factors for EGC in a large Western series. Over a 10‐year period from January 1979 to December 1988 a series of 332 patients (mean age 64 years) with EGC were operated on in 23 centers (two French Associations for Surgical Research). The clinicopathologic data retrospectively and screened it for prognostic effect. The mean follow‐up for the 332 EGC patients was 80 months. Postoperative mortality was 4% among 243 partial and 89 total gastric resections. The overall 5‐ and 7‐year survival rates were 82% and 72%, respectively. The cumulative 5‐ and 7‐year survival rates (mean follow‐up 80 months) were 92.0% and 87.5%, respectively, excluding both operative and unrelated mortality. There was no significant difference in survival between partial and total gastric resection for lesions located in the lower third of the stomach (p > 0.6). When survival data (excluding postoperative deaths) were analyzed using univariate analysis and Cox’s proportional hazards model, lymphatic involvement (p = 0.01), the site of the tumor in the upper two‐thirds of the stomach (p = 0.02), and submucosal lesions (p = 0.049) showed a significant effect on predicting a poor prognosis. These results suggest that because of its prognostic value lymphadenectomy should be performed in addition to gastric resection for adequate classification of EGCs. Follow‐up might be required only for patients with at least one poor prognostic factor.
Limited Hepatic Resection for Hepatocellular Carcinoma in the Caudate Lobe
Authors: Ikegami Toru , Ezaki Takahiro , Ishida Teruyoshi , Aimitsu Shiomi , Fujihara Megumu , Mori Masaki
Published: July 2004

The most appropriate approach to treating hepatocellular carcinoma (HCC) in the caudate lobe has not yet been determined. A series of 197 patients who had undergone curative hepatic resection for HCC were analyzed. Fifteen patients had HCC in the caudate lobe: three in the Spiegel lobe (SP), three in the caudate process (CP), and nine in the paracaval portion (PC). Patients with HCCs in the SP and CP underwent partial hepatectomy. HCCs in the PC were approached in one of three ways: anterior approach and partial hepatectomy of the PC (Ant+PHx‐PC), partial hepatectomy, or left lobectomy. Clinicopathologic variables, including the underlying liver disease, the mean tumor size, and the pathologic characteristics of HCC, did not differ between surgery of the caudate lobe and that of other segments. The overall survival was 88.9% at 3 years and 66.7% at 5 years after resection of HCC in the caudate lobe; the corresponding figures were 86.1% at 3 years and 68.6% at 5 years for the other segments. The recurrence‐free survival rate was 51.9% at 3 years and 34.6% at 5 years for the caudate lobe, and it was 52.1% at 3 years and 32.8% at 5 years for the other segments. Clinicopathologic characteristics of HCCs originating in the caudate lobe were not different from those in the other segments. Limited resection of HCC in the caudate lobe confers a similar prognostic value as in other segments.
Crystal structure and reactivity of YbdL from Escherichia coli identify a methionine aminotransferase function
Authors: Dolzan Manuela , Johansson Kenth , Roig-Zamboni Véronique , Campanacci Valérie , Tegoni Mariella , Schneider Gunter , Cambillau Christian
Published: July 2004

The ybdL gene of Escherichia coli codes for a protein of unknown function. Sequence analysis showed moderate homology to several vitamin B6 dependent enzymes, suggesting that it may bind pyridoxal‐5′‐phosphate. The structure analysis of YbdL to 2.35 Å resolution by protein crystallography verifies that it is a PLP dependent enzyme of fold type I, the typical aspartate aminotransferase fold. The active site contains a bound pyridoxal‐5′‐phosphate, covalently attached to the conserved active site lysine residue Lys236. The pattern of conserved amino acids in the putative substrate binding pocket of the enzyme reveals that it is most closely related to a hyperthermophilic aromatic residue aminotransferase from the archeon Pyrococcus horikoshii. Activity tests with 10 amino acids as amino‐donors reveal, however, a preference for Met, followed by His and Phe, results which can be rationalized by modelization studies.
Predictors of wound complications after laryngectomy: A study of over 2000 patients
Authors: Schwartz Seth R. , Yueh Bevan , Maynard Charles , Daley Jennifer , Henderson William , Khuri Shukri F.
Published: July 2004

OBJECTIVES

To identify risk factors for and the rate of wound complications after laryngectomy in a large, prospectively collected national dataset, and to generate a predictive model.

STUDY DESIGN

We used the National Surgical Quality Improvement Program (NSQIP) registry created by the Department of Veterans Affairs (VA) to identify patients undergoing total laryngectomy from 1989 to 1999 (n = 2063). We linked these data to inpatient and outpatient VA administrative records to capture data for prior radiation. Over 20 preoperative and intraoperative risk factors were analyzed using bivariate techniques. Those significant at the P < 0.01 level were analyzed with logistic regression and conjunctive consolidation to identify independent predictors of wound complications.

RESULTS

The overall wound complication rate was 10.0%. In adjusted analyses, prolonged operative time (> 10 hours, odds ratio = 2.10, 95% confidence interval: 1.32‐3.36), exposure to prior radiation therapy (OR =1.63, 1.07‐2.46), presence of diabetes (OR = 1.78, 1.04‐3.04), preoperative hypoalbumine‐mia (OR =1.90, 1.32‐2.74), anemia (OR =1.59, 1.07‐2.36), and thrombocytosis (OR =1.48, 1.04‐2.10) were independently associated with postoperative wound complications. A prognostic model using three variables—prior radiation therapy, diabetes, and hypoalbuminemia—provided excellent risk stratification into three tiers (6.3%, 13.7%, 21.7%).

CONCLUSIONS

Preoperative radiation, prolonged operative time, low albumin, and diabetes were independently associated with postoperative wound infections. These results will help to identify patients at risk for wound complications, thus allowing for heightened surveillance and preventive measures where possible.
Preliminary Report Of Endolaryngeal And Endotracheal Laser Surgery Of Juvenile‐Onset Recurrent Respiratory Papillomatosis By Nd:Yag Laser and a New Fiber Guidance Instrument
Authors: Janda Philip , Leunig Andreas , Sroka Ronald , Betz Christian S. , Rasp Gerd
Published: July 2004

OBJECTIVES

Recurrent respiratory papillomatosis (RRP) caused by human papilloma virus (type 6 and 11) is the most common benign neoplasm of the larynx in children. Despite being a benign disease, treatment is very difficult and is characterized by frequent recurrence, spread throughout the respiratory tract, and malignant degeneration. Besides surgical resection and the established CO2 laser treatment, laser surgery by fiber‐guided Nd:YAG laser light promises to be a bloodless and effective treatment procedure. To improve this new method, a novel fiber guidance instrument has been developed to aid in endolaryneal laser surgery of RRP.

STUDY DESIGN AND SETTING

The method described uses a specially designed instrument for fiber guidance that is equipped with a bendable distal tip to move the fiber end precisely. Moreover, the instrument includes an additional channel for the suction of smoke and pyrolysis products. Up to now, 5 patients (aged 4 to 8 years) with RRP were treated by Nd:YAG laser light (λ = 1064 nm; power, 10W; irradiance, 3.5 kW/cm2, continuous wave) with a prototype version of the new instrument and were followed up for 12 months each. RESULTS: Because of the adequate length and the bendable distal tip with a range of −5° up to 45° to the optical axis of the fiber and less than 10% light loss at maximal deflection, RRP can be treated by Nd:YAG laser light easily and precisely. The continuous suctioning ensured an optimum view of the operating field and a minimal load of potential infectious laser plume and toxic pyrolysis products for the patient as well as for the physician. The laser treatment of RRP with the new fiber guidance instrument was only minimally traumatic. During 1‐year follow‐up visits, all Nd:YAG laser light‐treated patients, showed a regression of the disease.

CONCLUSIONS

The new fiber guidance instrument enables a precise and easy treatment of the RRP with fiber‐guided laser systems (eg, Nd:YAG‐, diode‐, and KTP‐lasers) and an effective removal of infectious laser plume as well as toxic pyrolysis products. A follow‐up period of 1 year revealed that Nd:YAG laser surgery seems to prevent a rapid recurrence of juvenile respiratory papillomatosis in the treated patients.
Significance of Asymptomatic Tonsil Asymmetry
Authors: Cinar Fikret
Published: July 2004

OBJECTIVE

Asymmetry of tonsils that arouses suspicion for malignancy is one of the indications for tonsillectomy. The purpose of this study was to evaluate the incidence of occult malignancy in patients with asymptomatic unilateral tonsillar enlargement.

STUDY DESIGN AND SETTING

A prospective controlled trial was carried out in two institutions, Beyoglu Research and Training Hospital and Karaelmas University Hospital, during a 6‐year period. Of patients selected for tonsillectomy, patients with unilateral tonsillar enlargement were identified and were included in this study. Patients who had risk factors that were significant for malignancy were excluded. After excision, two tonsil specimens were measured before sending for histology. Matched controls with symmetric tonsils underwent the same procedures. Preoperative diagnosis of tonsil asymmetry with the postoperative histologic diagnosis were correlated for the incidence of malignancy.

RESULTS

Of the 792 patients undergoing tonsillectomy, 53 patients (6.69%) with asymmetry of tonsils and who had no other risk factors for malignancy underwent tonsillectomy. The size difference of the tonsils ranged from 0 to 19 mm. In the control group of 51 patients with symmetric tonsils, the size difference ranged from 0 to 8 mm. The analysis showed statistically significant difference in the degree of asymmetry between the two groups (P <. 001). Most of the specimens contained reactive lymphoid hyperplasia in both groups (58.49% and 54.9%, respectively). No malignancies or unusual pathological findings were encountered on histologic examination in either group.

CONCLUSION AND SIGNIFICANCE

Tonsil asymmetry may only be apparent in patients with an otherwise normal physical examination, secondary to benign hyperplasia or anatomical factors. Therefore, the presence of tonsil asymmetry without factors such as suspicious appearance, significant systemic signs and symptoms, progressive enlargement of the tonsil, concomitant neck adenopathies, and history of malignancy or immunocompromise, may not indicate malignancy, as a sole clinical feature.
Postoperative Infection in Cochlear Implant Patients
Authors: Cunningham Calhoun D , Slattery William H. , Luxford William M.
Published: July 2004

OBJECTIVE

Recently, the association of meningitis with cochlear implants has raised concern over the safety of these devices. We examined the incidence of all postoperative infections in patients undergoing cochlear implant surgery.

STUDY DESIGN AND SETTINGS

A retrospective chart review of all patients undergoing cochlear implants at a private tertiary referral center from 1993 to 2002 was performed. Cochlear implant surgeries in 462 adults and 271 children were reviewed. Patients with evidence of a postoperative infection or infectious complication related to cochlear implantation were identified, and data on patient characteristics, surgery, and treatment outcome were obtained.

RESULTS

The overall incidence of postoperative infection in our cochlear implant series was 4.1%. Major infectious complications occurred in 3.0% of cases, and the majority of infections required surgical intervention. A history of chronic ear disease may increase the risk of infectious complications. There were no cases of meningitis.

CONCLUSIONS

Cochlear implants remain a safe procedure with a low complication rate. The majority of infections can be managed without removing the implant device. Advances in surgical technique and flap design have decreased the occurrence of wound‐related complications. However, identification of risk factors for infection and optimization of treatment regimens will further reduce the complications associated with postoperative infection.
C‐Myc And Bcl‐2 Expression In Supraglottic Squamous Cell Carcinoma of the Larynx
Authors: Ozdek Ali , Sarac Sarp , Akyol M. Umut , Sungur Arzu , Yilmaz Taner
Published: July 2004

OBJECTIVES

To evaluate the expression and prognostic significance of c‐myc and bcl‐2 oncogenes in squamous cell carcinoma (SCC) of the supraglottic larynx.

STUDY DESIGN

A retrospective cohort study of 61 patients who underwent surgery for SCC of the supraglottic larynx. Gender, age, TNM status, operative procedure, recurrences, and disease‐free survival periods were recorded.

METHODS

Hematoxylin and eosin‐stained sections were reexamined for grade, invasion of tumor margins, lymphovascular invasion, lymphocyte infiltration, and perineural invasion. Immunohistochemical detection of c‐myc and bcl‐2 oncogenes was performed using monoclonal antibodies.

RESULTS: No correlation was observed between either c‐myc or bcl‐2 and the clinical and histopathologic parameters. Survival analysis revealed no correlation of either c‐myc (P = 0.88) or bcl‐2 (P = 0.85) with the disease‐free survival. c‐myc expression was found to be significantly higher in bcl‐2‐positive patients (P = 0.001).

CONCLUSION: Neither c‐myc nor bcl‐2 had shown to be prognostic factor for laryngeal carcinoma in this present study. Correlation between c‐myc and bcl‐2 supports the experimental observations of cooperative action between these two genes in tumorigenesis.
Removal of Fish Bones in the Oropharynx and Hypopharynx Under Video Laryngeal Telescopic Guidance
Authors: Lee Fei‐Peng
Published: July 2004

OBJECTIVE

The study goal was to present the technique and results of removal of fish bones in the oropharynx and hypopharynx under video laryngeal telescopic guidance.

STUDY DESIGN AND SET

From January 2001 to December 2002, a total of 27 patients with fish bones lodged in the oropharynx and hypopharynx were studied at the ENT Department of Taipei Medical University Hospital.

RESULTS

All fish bones were removed smoothly without necessitating further procedures at the time of the initial clinical examination and had an uneventful clinical course.

CONCLUSION: Removal of fish bones lodged at the tongue base, vallecula, and hypopharynx under video laryngeal telescopic guidance has the advantages of good illumination, clear visualization, and precise extraction. The technique has also proven to be efficient, safe, well tolerated, and with low morbidity.

SIGNIFICANCE: Removal of the fish bones from difficult areas in oropharynx and hypopharynx with this technique can reduce the use of direct laryngoscope under general anesthesia.
Intracordal Injection of Autologous Auricular Cartilage in the Paralyzed Canine Vocal Fold
Authors: Lee Byung‐Joo , Wang Soo‐Geun , Goh Eui‐Kyung , Chon Kyon‐Myong , Lee Chang‐Hun
Published: July 2004

OBJECTIVE

Vocal fold augmentation by injectable material under direct visual control is an easy and simple operation. However, when autologous fat or bovine collagen is used, resorption creates a problem. And autologous fascia is debating about absorption now days. This study is to evaluate the histology of minced and injected autologous auricular cartilage and fat graft in the augmentation of unilateral vocal fold paralysis using a canine model.

METHOD

Nine dogs were operated. At first, a piece of auricular cartilage was harvested from ear and minced into tiny chips with a scalpel, and a piece of fat tissue was harvested from inguinal area and minced into tiny chips with a scalpel. Cutting off a section of the recurrent nerve paralyzed the right vocal fold. The minced cartilage and fat‐paste (0.2 mL) was injected using a pressure syringe into the paralyzed thyroarytenoid muscle under direct laryngoscopy. Two animals were sacrificed at 3 days, three at 3 weeks, two at 3 months, one at 6 months, and one at 12 months. Each dog underwent laryngectomy and serial coronal sections of paraffin blocks from the posterior part of the vocal fold were made.

RESULTS

There was no significant complication perioperatively and during follow‐up. There was acute inflammatory findings in the graft at 3 days and 3 weeks. The injected cartilage remained in the larynx until 12 months.

CONCLUSION

The autologous auricular cartilage graft is well tolerated and may be very effective material for volumetric augmentation on paralyzed vocal cord.
Ototoxic Protection of Sodium Thiosulfate: Daily vs Constant Infusion
Authors: Stocks Rose Mary S. , Gould Herbert J. , Bush Andrew J. , Dudney B. Wayne , Pousson Monique , Thompson Jerome W.
Published: July 2004

OBJECTIVE

Compare the effect of a daily dose of sodium thiosulfate (STS) to continuous infusion of STS on Hartley albino guinea pig (HAGP) on cisplatin (CP)‐induced sensorineural hearing loss.

STUDY DESIGN

Prospective randomized pilot study comparing a single daily dose of STS to a constant controlled infusion of STS given the middle ear space (MES) with an ototoxic regimen of CP. The hearing thresholds will be obtained by auditory brainstem response (ABR) 1 week before and after treatment. Treatment effects on responses at 2, 8, and 16 kHz signals will be investigated by an analysis of variance with one between subjects' condition and two within subjects' conditions.

SETTING

Basic science laboratory.

RESULTS

STS protection resulted in significantly less hearing loss post‐treatment for the protected ears. Guinea pigs with continuous infusion of STS demonstrated less loss in the protected ear than those who received the single daily dose. As expected, hearing loss at 2 kHz was less than that at 8 and 16 kHz.

CONCLUSION

A continuous infusion of STS directly to the MES is better than a single daily dose of STS to the MES in reducing the ototoxicity of CP.

SIGNIFICANCE

Any targeted protection, whether by continuous infusion or daily dose, is better than no protection against the sensorineural hearing loss of CP.
Adenotonsillectomy for Obstructive Sleep Apnea in Obese Children
Authors: Mitchell Ron B. , Kelly James
Published: July 2004

OBJECTIVE

To study changes in sleep behavior and quality of life in obese children after adenotonsillectomy for obstructive sleep apnea.

STUDY DESIGN AND SETTING

Prospective study at the University of New Mexico Children's Hospital.

METHODS

Children who met inclusion criteria and had a respiratory distress index (RDI) greater than 5 were enrolled in the study and underwent adenotonsillectomy. All children underwent preoperative and postoperative full‐night polysomnography. Age‐ and gender‐specific percentile BMI was recorded at the time of polysomnography. Caregivers were asked to complete an OSA‐18 quality of life survey prior to polysomnography and a second survey within 6 months of surgery. Scores from preoperative and postoperative polysomnography and OSA‐18 surveys were compared using the paired Student's t test.

RESULTS

The study population included 30 children. Twenty‐six children (86%) were male. The mean age of the children at the time of inclusion in the study was 9.3 years; range, 3.0 to 17.2. The mean preoperative BMI was 28.6 (range, 19.2 to 47.1) and the mean postoperative BMI was 27.9 (range, 17.8 to 27.9). A 2‐tailed paired t test showed that this difference is not statistically significant (P = 0.06). The mean preoperative RDI was 30.0 and the mean postoperative RDI was 11.6 (P < 0.001). The preoperative mean total OSA‐18 score was 78.2 and the postoperative mean total score was 39.8 (P < 0.001).

CONCLUSION

Obese children with OSA who undergo adenotonsillectomy show a marked improvement in RDI and in quality of life with no change in BMI. However, in the majority of children, OSA does not resolve.
Pediatric Suprastomal Granuloma: Management and Treatment
Authors: Gupta Akash , Cotton Robin T. , Rutter Michael J.
Published: July 2004

OBJECTIVE

Suprastomal granulomas (SSG) are a common complication of pediatric tracheotomy. Occasionally excision is indicated for obstructive granulomas. We report on our experience on the management of SSG requiring excision.

STUDY DESIGN AND SETTING

A retrospective chart review of 68 patients who underwent SSG excision at a tertiary referral pediatric hospital between July 1997 and November 2002. The medical charts were reviewed for excision techniques and outcomes.

RESULTS

A total of 106 excisions of SSG were performed on 68 patients. Of the patients, 25 (36.8%) required multiple excisions. Removal techniques included sphenoid punch (34.9%), optical forceps (34.0%), open excision (22.6%), electrocautery (4.7%), and hook and eversion (3.8%).

CONCLUSION

The majority of SSG do not require removal. If excision is indicated, we recommend using optical forceps for soft and friable lesions and the sphenoid punch for fibrous and firm granulomas. For granulomas that have a broad base, are very large, or where endoscopic instrumentation is not possible, we recommend open excision.
Fusaric acid: A novel agent and mechanism to treat HNSCC
Authors: Stack Brendan C. , Hansen J. Paul , Ruda James M. , Jaglowski Jeff , Shvidler Joseph , Hollenbeak Christopher S.
Published: July 2004

OBJECTIVE

A new class of carboxylic acids has tumoricidal activity for head and neck squamous cell cancer (HNSCC). Fusaric acid (FA) can chelate divalent cations, especially zinc, and inactivate zinc finger proteins involved in DNA repair and protein synthesis.

METHODS

2 squamous carcinoma lines were utilized for in vitro and in vivo portions of this study. Cell counting and flow cytometry were used to analyze cells in culture in treatment and control groups over 96 hours. HNSCC subcutaneous implants were created in treatment and control groups of BALB‐c nude mice (N = 30).

RESULTS

In vitro studies demonstrated significant changes in cell numbers and cell cycle. In vivo studies of daily intralesional therapy for 1 month also showed reduced onset of growth and overall growth compared to controls.

CONCLUSION

FA appears to have a tumoristatic/tumoricidal effect on HNSCC. Further nude mice studies are needed to optimize dosing and administration regimens for FA in anticipation of clinical trials.