bluuebunny/crossref_metadata_2025 huggingface dataset:
Characterization of the outer membrane protein OprF of Pseudomonas aeruginosa in a lipopolysaccharide membrane by computer simulation
Authors: Straatsma T.P. , Soares T.A.
Published: July 2008

The N‐terminal domain of outer membrane protein OprF of Pseudomonas aeruginosa forms a membrane spanning eight‐stranded antiparallel β‐barrel domain that folds into a membrane channel with low conductance. The structure of this protein has been modeled after the crystal structure of the homologous protein OmpA of Escherichia coli. A number of molecular dynamics simulations have been carried out for the homology modeled structure of OprF in an explicit molecular model for the rough lipopolysaccharide (LPS) outer membrane of P. aeruginosa. The structural stability of the outer membrane model as a result of the strong electrostatic interactions compared with simple lipid bilayers is restricting both the conformational flexibility and the lateral diffusion of the porin in the membrane. Constricting side‐chain interactions within the pore are similar to those found in reported simulations of the protein in a solvated lipid bilayer membrane. Because of the strong interactions between the loop regions of OprF and functional groups in the saccharide core of the LPS, the entrance to the channel from the extracellular space is widened compared with the lipid bilayer simulations in which the loops are extruding in the solvent. The specific electrostatic signature of the LPS membrane, which results in a net intrinsic dipole across the membrane, is found to be altered by the presence of OprF, resulting in a small electrically positive patch at the position of the channel. Proteins 2009. © 2008 Wiley‐Liss, Inc.
PFP: Automated prediction of gene ontology functional annotations with confidence scores using protein sequence data
Authors: Hawkins Troy , Chitale Meghana , Luban Stanislav , Kihara Daisuke
Published: July 2008

Protein function prediction is a central problem in bioinformatics, increasing in importance recently due to the rapid accumulation of biological data awaiting interpretation. Sequence data represents the bulk of this new stock and is the obvious target for consideration as input, as newly sequenced organisms often lack any other type of biological characterization. We have previously introduced PFP (Protein Function Prediction) as our sequence‐based predictor of Gene Ontology (GO) functional terms. PFP interprets the results of a PSI‐BLAST search by extracting and scoring individual functional attributes, searching a wide range of E‐value sequence matches, and utilizing conventional data mining techniques to fill in missing information. We have shown it to be effective in predicting both specific and low‐resolution functional attributes when sufficient data is unavailable. Here we describe (1) significant improvements to the PFP infrastructure, including the addition of prediction significance and confidence scores, (2) a thorough benchmark of performance and comparisons to other related prediction methods, and (3) applications of PFP predictions to genome‐scale data. We applied PFP predictions to uncharacterized protein sequences from 15 organisms. Among these sequences, 60–90% could be annotated with a GO molecular function term at high confidence (≥80%). We also applied our predictions to the protein–protein interaction network of the Malaria plasmodium (Plasmodium falciparum). High confidence GO biological process predictions (≥90%) from PFP increased the number of fully enriched interactions in this dataset from 23% of interactions to 94%. Our benchmark comparison shows significant performance improvement of PFP relative to GOtcha, InterProScan, and PSI‐BLAST predictions. This is consistent with the performance of PFP as the overall best predictor in both the AFP‐SIG ′05 and CASP7 function (FN) assessments. PFP is available as a web service athttp://dragon.bio.purdue.edu/pfp/. Proteins 2009. © 2008 Wiley‐Liss, Inc.
The crystal structures of the psychrophilic subtilisin S41 and the mesophilic subtilisin Sph reveal the same calcium‐loaded state
Authors: Almog Orna , González Ana , Godin Noa , de Leeuw Marina , Mekel Marlene J. , Klein Daniela , Braun Sergei , Shoham Gil , Walter Richard L.
Published: July 2008

We determine and compare the crystal structure of two proteases belonging to the subtilisin superfamily: S41, a cold‐adapted serine protease produced by Antarctic bacilli, at 1.4 Å resolution and Sph, a mesophilic serine protease produced by Bacillus sphaericus, at 0.8 Å resolution. The purpose of this comparison was to find out whether multiple calcium ion binding is a molecular factor responsible for the adaptation of S41 to extreme low temperatures. We find that these two subtilisins have the same subtilisin fold with a root mean square between the two structures of 0.54 Å. The final models for S41 and Sph include a calcium‐loaded state of five ions bound to each of these two subtilisin molecules. None of these calcium‐binding sites correlate with the high affinity known binding site (site A) found for other subtilisins. Structural analysis of the five calcium‐binding sites found in these two crystal structures indicate that three of the binding sites have two side chains of an acidic residue coordinating the calcium ion, whereas the other two binding sites have either a main‐chain carbonyl, or only one acidic residue side chain coordinating the calcium ion. Thus, we conclude that three of the sites are of high affinity toward calcium ions, whereas the other two are of low affinity. Because Sph is a mesophilic subtilisin and S41 is a psychrophilic subtilisin, but both crystal structures were found to bind five calcium ions, we suggest that multiple calcium ion binding is not responsible for the adaptation of S41 to low temperatures. Proteins 2009. © 2008 Wiley‐Liss, Inc.
Epitaxial electrodeposition of ZnO thin film on GaN(0001) bulk single crystal
Authors: Ichinose Keigo , Yoshida Tsukasa
Published: July 2008

Ga terminated surface of heavily doped conductive GaN(0001) bulk single crystal was used as a rotating disk electrode (RDE) to electrodeposit ZnO thin film employing reduction of O2. Although the native surface was rather inactive for the reduction of O2, it was activated by dipping in HCl and further by prolonged electrolysis to reduce O2 in a Zn2+ free solution. Koutecky–Levich analysis revealed important kinetic constants, such as the standard charge transfer rate constant (k0) of 2.4 × 10–14 cm s–1 and the transfer coefficient (α) of 0.11 at 70 °C for the reduction of O2 at the most activated GaN(0001). Electrodeposition of ZnO from the bath containing ZnCl2 lead to an epitaxial growth of ZnO in a ZnO[100] ‖ GaN[100] alignment as confirmed from the XRD ω scan with θ adjusted to ZnO(10$ \bar 1 $2). The higher level of epitaxy was achieved for the more active surfaces of GaN as estimated from narrowing of the full width at half maximum (fwhm) of the peaks in the XRD ω ‐scan. Such films were also fully covering the surface of GaN as found in the SEM observation. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Electrodeposition and impedance spectroscopy characterization of ZnO nanowire arrays
Authors: Tena‐Zaera R. , Elias J. , Lévy‐Clément C. , Mora‐Seró I. , Luo Y. , Bisquert J.
Published: July 2008

An overview of the electrodeposition of ZnO nanowire arrays from the reduction of dissolved molecular oxygen in zinc chloride solutions was reported. In spite of the internal structure of ZnO which favours the anisotropic growth along the [0001] direction, the change in the local composition of the electrolyte around the nanowire during the electrodeposition was proposed as a major parameter to affect the nanowire growth mechanism. The influence of the ratio between the O2 reduction rate and the diffusion of Zn2+ to the cathode was emphasized. Due to the particular morphology of the nanowire arrays, no lateral growth was observed when the reduction of O2 was relatively fast, while the corresponding deposition efficiency was very low. The decrease of the O2 reduction rate resulted in an enhancement of the deposition efficiency. The highest efficiencies (40–55%) were attained by using high chloride concentrations ([KCl] = 3.4 M) resulting not only in an enhancement of the longitudinal growth, but also in a considerable lateral growth. The influence of the electrodeposition conditions on the donor density of ZnO nanowires was investigated by using electrochemical impedance spectroscopy. Donor densities from 5 × 1019 cm–3 to 3 × 1020 cm–3 were obtained for as deposited samples. They decreased to values in the range of 1017–1018 cm–3 after annealing in air (1 hour at 450 °C). (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Synthesis of ZnO nanorod/nanotube arrays formed by hydrothermal growth at a constant zinc ion concentration
Authors: Ndifor‐Angwafor N. George , Riley D. Jason
Published: July 2008

In the hydrothermal growth of macroscopic arrays of 1‐dimensional zinc oxide on seeded substrates the morphology of the individual nanoparticles changes during the reaction, typically nanorods taper to nanotubes for reaction times in excess of 3 hours. In this paper it is demonstrated that by keeping the zinc ion concentration in the reaction solution constant, using potentiostatically controlled dissolution of a sacrificial zinc working electrode, during the precipitation of zinc oxide, it is possible to synthesise arrays of 1‐dimensional zinc oxide particles which have a constant diameter along their entire length, even after 10 hours of growth. These finding indicate the importance of the concentration of zinc ions in determining the morphology of the deposited nanorods. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Analysis of ethylenethiourea as a biomarker in human urine using liquid chromatography/triple quadrupole mass spectrometry
Authors: Lindh Christian H. , Littorin Margareta , Johannesson Gunvor , Jönsson Bo A. G.
Published: July 2008

Ethylenebisdithiocarbamates (EBDCs) are widely used fungicides. Ethylenethiourea (ETU), the main metabolite and also a contaminant in the commercially available products, is of major toxicological concern. In this study, a method using liquid chromatography/triple quadrupole mass spectrometry (LC/MS/MS) is described for the analysis of ETU in human urine after a single‐step extractive derivatization using pentafluorobenzyl bromide (PFBBr). Analysis was carried out using selected reaction monitoring (SRM) in the positive ion mode. Quantification of ETU was performed using [2H4]‐labeled ETU as internal standard (IS). The limit of detection (LOD) was determined to 0.05 ng/mL. The method was linear in the range 0.1–54 ng/mL urine and had a within‐run precision of 3–5%. The between‐run precision was determined at an average urine level of 2 and 10 ng/mL urine and found to be 9%. The inter‐batch precision was 6%. To validate ETU as a biomarker of exposure, the method was applied in a human experimental oral exposure to the commercial fungicide Ridomil Gold, containing 64% mancozeb and 4.5% ETU. Two healthy volunteers received 8.9 µg/kg body weight (b.w.) Ridomil Gold in a single oral dose followed by urine sampling for 104 h post‐exposure. The elimination half‐life of ETU was estimated to 17–23 h. Copyright © 2008 John Wiley & Sons, Ltd.
Malathion‐induced oxidative stress in human erythrocytes and the protective effect of vitamins C and E in vitro
Authors: Durak Dilek , Uzun Fatma Gökce , Kalender Suna , Ogutcu Ayse , Uzunhisarcikli Meltem , Kalender Yusuf
Published: July 2008

Malathion is an organophosphate (OP) pesticide that has been shown to induce oxidative stress in erythrocytes through the generation of free radicals and alteration of the cellular antioxidant defense system. We examined the effect of several different doses of malathion (25, 75, 200 μM), or malathion in combination with vitamin C (VC; 10 μM) or vitamin E (VE; 30 μM), on the levels of malondialdehyde (MDA), and superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) activities in human erythrocytes in vitro. Erythrocytes were incubated under various treatment conditions (malathion alone, vitamins alone, or malathion plus vitamin) at 37°C for 60 min, and the levels of MDA, and SOD, CAT and GPx activities, were determined. Treatment with malathion alone increased the levels of MDA and decreased SOD, CAT, and GPx activities in erythrocytes (P < 0.05). There were no statistical differences among VC‐treated, VE‐treated, or VC + VE‐treated erythrocyes, as compared with nontreated control cells. Treatment of cells with malathion + VC, malathion + VE, or a combination of all three agents prevented malathion‐induced changes in antioxidant enzyme activity and lipid peroxidation. However, this effect was seen only at low concentrations of malathion (25 and 75 μM), and the combination of VC + VE had a more protective effect than VC or VE alone. These results indicated that the presence of vitamins at concentrations that are similar to the levels found in plasma have no effect on malathion‐induced toxicity in erythrocytes at a concentration of malathion (200 μM) that is typically used in pesticides. © 2008 Wiley Periodicals, Inc. Environ Toxicol, 2009.
Adrenomedullin reduces antioxidant defense system and enhances kidney tissue damage in cadmium and lead exposed rats
Authors: Yurekli Muhittin , Esrefoglu M. , Ilker Doğru M. , Doğru Arzu , Gul M. , Whidden M.
Published: July 2008

Adrenomedullin (AdM) is synthesized and secreted by a number of cells and tissue. AdM is a potent vasodilator but it is also considered a neuromodulator, an angiogenic factor, and a hormone regulator. AdM possess antiapoptotic, antioxidant, and antimicrobial properties. Heavy metals such as cadmium and lead are found widely in the environment and they have important biological functions. Lead (Pb) and cadmium (Cd) can accumulate in the lungs, liver, bone, and kidneys and cause serious organ damage. In the present study, we investigated the effect of AdM, Pb + AdM, and Cd + AdM treatments on superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH‐Px) activities as well as the level of malondialdehyde (MDA) in the kidney. Heavy metal accumulation was determined in kidney with and without AdM infusion and kidney damage was evaluated by light and electron microscopy. Increased heavy metal accumulation was observed in the heavy metal and AdM treated groups. SOD, CAT, GSH‐Px activities, and MDA levels were significantly different in the treatment groups when compared with the control group. Tubular degeneration, necrosis, cell swelling, mononuclear cell infiltration, and degenerated organelles were observed in the kidney following treatment. Therefore, AdM infusion has no beneficial and/or compensatory role in cadmium and lead toxicity in the kidney. We conclude that heavy metal accumulation in the kidney in conjunction with AdM infusion is cytotoxic despite the known beneficial effects of adrenomedullin. © 2008 Wiley Periodicals, Inc. Environ Toxicol, 2009.
Performance analysis of a P2P‐enabled TDD‐CDMA network with intra‐cell spatial resource reuse
Authors: Zhang Yan , Du Lin , Shang Dan , Yang Yuhang
Published: July 2008

In this paper a scheme of intra‐cell spatial resource reuse is proposed for a peer‐to‐peer (P2P) enabled TDD‐CDMA system to increase the system capacity via only software update. On account of the new interference scenario in our scheme, a more accurate model of signal to interference and noise ratio (SINR) is deduced and analyzed instead of using the conventional equation. As demonstrated by our system‐level simulations, the capacity is significantly improved by reusing the same radio resource among different P2P transmitters within a single cellular cell in the spatial domain. Furthermore, we employ critical values of SINR target observed from simulation results to indicate whether the P2P‐enabled system is resource‐restricted or interference‐restricted for a certain application scenario. By means of a hexagon‐padding plan, the relation between co‐channel reuse distance and single‐hop distance is also pointed out to help to apply our scheme to a real implementation. Copyright © 2008 John Wiley & Sons, Ltd.
A Versatile Route for the Synthesis of Nickel Oxide Nanostructures Without Organics at Low Temperature
Authors: Shah MA
Published: July 2008

Nickel oxide nanoparticles and nanoflowers have been synthesized by a soft reaction of nickel powder and water without organics at 100 °C. The mechanism for the formation of nanostructures is briefly described in accordance with decomposition of metal with water giving out hydrogen. The structure, morphology, and the crystalline phase of resulting nanostructures have been characterized by various techniques. Compared with other methods, the present method is simple, fast, economical, template-free, and without organics. In addition, the approach is nontoxic without producing hazardous waste and could be expanded to provide a general and convenient strategy for the synthesis of nanostructures to other functional nanomaterials.
Growth of Y-shaped Carbon Nanofibers from Ethanol Flames
Authors: Cheng Jin , Zou Xiaoping , Zhang Hongdan , Li Fei , Ren Pengfei , Zhu Guang , Su Yi , Wang Maofa
Published: July 2008

Y-shaped carbon nanofibers as a multi-branched carbon nanostructure have potential applications in electronic devices. In this article, we report that several types of Y-shaped carbon nanofibers are obtained from ethanol flames. These Y-shaped carbon nanofibers have different morphologies. According to our experimental results, the growth mechanism of Y-shaped carbon nanofibers has been discussed and a possible growth model of Y-shaped carbon nanofibers has been proposed.
Paracrine action of HO‐1‐modified mesenchymal stem cells mediates cardiac protection and functional improvement
Authors: Zeng Bin , Ren Xiaofeng , Lin Guosheng , Zhu Chengang , Chen Honglei , Yin Jiechao , Jiang Hong , Yang Bo , Ding Danhua
Published: July 2008

The aim has been to determine whether the supernatants of mesenchymal stem cells (MSCs) transfected with adenovirus carrying human heme oxygenase‐1 (hHO‐1) gene protect cardiomyocytes from ischemic injury. We have found that hHO‐1 infected MSCs (hHO‐1‐MSCs) increased expression of hHO‐1 protein. Apoptosis of cultured hHO‐1‐MSCs exposed to hypoxia was suppressed. Several cytokines, including HGF, bFGF, TGF‐β, VEGF and IL‐1β, were produced by hHO‐1‐MSCs, some being significantly enhanced under hypoxia stimulation. Meanwhile, those cytokines reduced caspase‐3 level and activity in cultured adult rat ventricular cardiomyocytes (ARVCs) exposed to hypoxia. Supernatants obtained from hHO‐1‐MSCs improved left ventricular function, limited myocardial infarct size, increased microvessel density, and inhibited apoptosis of cardiomyocytes in rat myocardial infarction. It can be concluded hHO‐1‐modified MSCs prevent myocardial cell injury via secretion of paracrine‐acting mediators.
Effects of thymic polypeptides on the thymopoiesis of mouse embryonic stem cells
Authors: Peng Yanwen , Chen Zhenguang , Yu Weihua , Zhou Qifeng , Xu Lin , Mao Frank Fuxiang , Huang Gang , Zhang Xiuming , Li Shunong , Lahn Bruce T. , Xiang Andy Peng
Published: July 2008

The thymus provides a unique cellular and hormonic microenvironment for the development of immunocompetent T cells. Thymic polypeptides have been widely used clinically for the treatment of tumors, infectious diseases and immune deficiency diseases. They have already shown the ability to stimulate the maturation of hematopoietic stem cells towards the CD3+CD4+ T cell lineage. However, their effects on the thymopoiesis of embryonic stem cells are still unexplored.

In this paper, we compared the effects of three thymic polypeptides, thymopentin (TP5), thymosin alpha‐1 (Tα‐1) and thymopeptides on the in vitro thymopoiesis of mouse embryonic stem (ES) cells. Using the embryoid body induction system, we found that both Tα‐1 and thymopeptides effectively induced ES cells to differentiate sequentially into the CD3+ and CD4+/CD8+ T cells. These T cells had T cell receptor (TCR) Vβ gene rearrangement and most were TCRαβ T cells. We also found that the expression of the Notch receptor and its ligands Delta‐like‐1 and Delta‐like‐4 gradually increased during the induction. However, TP5 failed to induce the T cell differentiation of the ES cells.

In summary, this is the first report to demonstrate that Tα‐1 can stimulate the T cell early stage differentiation from ES cells using the embryoid body protocol. These findings provide a powerful model for studying T cell development and may open new venues for the clinical application of Tα‐1.
Lysine induces lipid and protein damage and decreases reduced glutathione concentrations in brain of young rats
Authors: Seminotti Bianca , Leipnitz Guilhian , Amaral Alexandre U. , Fernandes Carolina G. , Silva Lucila de Bortoli da , Tonin Anelise Miotti , Vargas Carmen R. , Wajner Moacir
Published: July 2008

The present work investigated the in vitro effects of lysine on important parameters of oxidative stress in cerebral cortex of young rats. Our results show that lysine significantly induced lipid peroxidation, as determined by increase of thiobarbituric acid‐reactive substances and chemiluminescence levels, as well as protein oxidative damage since carbonyl formation and sulfhydryl oxidation were enhanced by this amino acid. Furthermore, the addition of free radical scavengers significantly prevented lysine‐induced lipid oxidative damage, suggesting that free radicals were involved in this effect. Lysine also significantly diminished glutathione levels in cortical supernatants, decreasing, therefore, the major brain antioxidant defense. Finally, lysine markedly oxidized a glutathione commercial solution in a medium devoid of brain supernatants, indicating that it behaved as a direct acting oxidant. The present data indicate that lysine induces oxidative stress in cerebral cortex of young rats. Therefore, it is presumed that this pathomechanism may be involved at least in part in the neurological damage found in patients affected by disorders with hyperlysinemia.
MYCN‐non‐amplified metastatic neuroblastoma with good prognosis and spontaneous regression: A molecular portrait of stage 4S
Authors: Bénard Jean , Raguénez Gilda , Kauffmann Audrey , Valent Alexander , Ripoche Hugues , Joulin Virginie , Job Bastien , Danglot Gisèle , Cantais Sabrina , Robert Thomas , Terrier-Lacombe Marie-José , Chassevent Agnès , Koscielny Serge , Fischer Matthias , Berthold Frank , Lipinski Marc , Tursz Thomas , Dessen Philippe , Lazar Vladimir , Valteau-Couanet Dominique
Published: July 2008

Stage 4 neuroblastoma (NB) are heterogeneous regarding their clinical presentations and behavior. Indeed infants (stage 4S and non‐stage 4S of age <365days at diagnosis) show regression contrasting with progression in children (>365days). Our study aimed at: (i) identifying age‐based genomic and gene expression profiles of stage 4 NB supporting this clinical stratification; and (ii) finding a stage 4S NB signature. Differential genome and transcriptome analyses of a learning set of MYCN‐non amplified stage 4 NB tumors at diagnosis (n=29 tumors including 12 stage 4S) were performed using 1Mb BAC microarrays and Agilent 22K probes oligo‐microarrays. mRNA chips data following filtering yielded informative genes before supervised hierarchical clustering to identify relationship among tumor samples. After confirmation by quantitative RT‐PCR, a stage 4S NB's gene cluster was obtained and submitted to a validation set (n=22 tumors). Genomic abnormalities of infant's tumors (whole chromosomes gains or loss) differ radically from that of children (intra‐chromosomal rearrangements) but could not discriminate infants with 4S from those without this presentation. In contrast, differential gene expression by looking at both individual genes and whole biological pathways leads to a molecular stage 4S NB portrait which provides new biological clues about this fascinating entity.
The chemokine interleukin‐8 and the surface activation protein CD69 are markers for Bcr–Abl activity in chronic myeloid leukemia
Authors: Hantschel Oliver , Gstoettenbauer Agnes , Colinge Jacques , Kaupe Ines , Bilban Martin , Burkard Thomas R. , Valent Peter , Superti-Furga Giulio
Published: July 2008

We have identified differentially regulated genes in chronic myeloid leukemia (CML) cells upon short treatment with the broad‐spectrum Bcr–Abl inhibitor dasatinib. The highly specific Bcr–Abl inhibitor nilotinib caused a very similar gene expression signature, validating the identified differentially regulated genes as a read‐out of Bcr–Abl activity and implying that Bcr–Abl is the functionally central target of dasatinib in CML cells. Among the strongest downregulated genes, we have further validated the activation marker CD69 and the chemokine interleukin (IL)‐8. Expression of both proteins is upregulated upon Bcr–Abl expression and inhibited by dasatinib and nilotinib. IL‐8 may thus be a useful marker for the monitoring of CML inhibitor efficacy and play a potential pathophysiological role in CML.
Lingual tonsillectomy: A review of 5 years experience and evolution of surgical technique
Authors: Barakate Michael , Havas Thomas
Published: July 2008

OBJECTIVES

To assess the indications for lingual tonsillectomy; to report our experience with lingual tonsillectomy, and to present the evolution of our surgical technique.

METHODS

A review of 5‐years experience from a prospectively maintained database of 28 patients was performed together with a focused review of the international literature. Therapeutic procedures included lingual tonsillectomy with access via the Boyle‐Davis gag or suspended video laryngoscope and with the resection via diathermy, CO2 laser, or microdebrider.

RESULTS

The indication for lingual tonsillectomy was upper airways obstruction in 22 patients and recurrent infection in six. The operative time for lingual tonsillectomy ranged from 35 to 80 minutes (mean time, 43 minutes). The perioperative in‐hospital stay ranged from one to three days for 27 patients. All did very well postoperatively.

CONCLUSION

Lingual tonsillar pathology may cause significant morbidity and is frequently the cause of persisting peripheral obstructive sleep apnea syndrome after adenotonsillectomy. Lingual tonsillectomy performed with video laryngoscopy and microdebrider resection is feasible and safe and provides good results.
Evaluation of meta‐analyses in the otolaryngological literature
Authors: Rudmik Luke R. , Walen Scott G. , Dixon Elijah , Dort Joseph
Published: July 2008

OBJECTIVE

To evaluate the quality of meta‐analyses written on otolaryngological topics and define areas that can be improved upon in future studies.

DATA SOURCES

MEDLINE (PubMed) and EMBASE databases were searched. The Cochrane database of systematic reviews was excluded, because these meta‐analyses have already been critically evaluated and found to be of high quality.

REVIEW METHODS

A systematic review of otolaryngological meta‐analyses published between 1997 and 2006 (10 years) was performed in duplicate and independently by two authors. The search included 16 common otolaryngological terms. Inclusion criteria were meta‐analytic methodology, otolaryngological topic, and at least one author from a department of otolaryngology. Fifty‐one articles fulfilled eligibility criteria. In duplicate and independently, two reviewers assessed the quality of eligible metaanalyses using a validated 10‐item index called the Overview Quality Assessment Questionnaire. Using the methods of Spearman, correlation coefficients are reported for associations examined between covariates and the Overall Score Quality.

RESULTS

The majority of studies had methodologic flaws (mean score 3.9, scale of 1‐7). Variables predicting higher‐quality meta‐analyses were publication in journals with higher impact factors (P = 0.0007) and authors who previously published metaanalyses (P = 0.0001). Using and reporting about a validity assessment tool needs to be improved upon in future studies.

CONCLUSION

The quality of meta‐analyses on otolaryngological topics is moderate. Future meta‐analyses can be improved upon by following evidence‐based guidelines for the reporting of metaanalyses, which include the use of a validity assessment tool, and consulting with an author familiar with meta‐analysis methodology.
Revascularization of rat fasciocutaneous flap using CROSSEAL® with VEGF protein or plasmid DNA expressing VEGF
Authors: McKnight Colin D. , Winn Shelley R. , Gong Xi , Hansen Juliana E. , Wax Mark K.
Published: July 2008

BACKGROUND

Fasciocutaneous tissue transfer is a common reconstructive procedure. Revascularization of flap tissue is an important component of tissue healing. Gene therapy offers an avenue through which the period of pedicle vascular dependency can be reduced.

MATERIALS AND METHODS

Rat fasciocutaneous flaps were elevated and a two‐hour ischemic time induced. Polycation complex (jet PEI) and human fibrin sealant CROSSEAL® was applied between flap and underlying abdominal tissues. Group 1 (six rats) was the control; Group 2 (seven rats) had vascular endothelial growth factor (VEGF) protein applied; Group 3 (seven rats) had plasmid DNA expressing VEGF applied. Vascular pedicles were ligated on postoperative day 5, percentage flap survival evaluated on day 7.

RESULTS

All flaps survived initial ischemia. Mean ± SD percentage area of the flap that survived was 28.1 ± 12.4 (Group 1), 71.6 ± 16.2 (Group 2), and 77.5 ± 12.7 (Group 3) (P < 0.001, Group 1‐3, 2‐3). No differences were observed between Groups 2 and 3.

CONCLUSIONS

Locally administered VEGF protein or plasmid DNA expressing VEGF enhanced survival of fasciocutaneous flaps.
Hearing impairment in pregnancy toxemia
Authors: Bakhshaee Mehdi , Hassanzadeh Malihe , Nourizadeh Navid , Karimi Ebrahim , Moghiman Toktam , Shakeri Mohammadtaghi
Published: July 2008

OBJECTIVE

Preeclampsia characterized by widespread endothelial damage and dysfunction, systemic toxicity, coagulation defects, and an increased systemic inflammatory response, poses some risk factors for hearing loss.

STUDY DESIGN

A case‐control study.

SUBJECTS AND METHODS

Two groups with 37 pre‐eclamptic and 38 healthy pregnant women were matched by age. Other factors that could possibly influence hearing were ruled out. Transient otoacoustic emission (TEOAE) was carried out for both groups before delivery and was repeated two weeks after delivery in cases of failure.

RESULTS

We could not find any abnormality in the healthy pregnant women who underwent the TEOAE test, but five of the preeclamptic women failed the initial test before delivery. This condition was recovered two weeks later. Statistical analysis showed significant difference (TEOAE disturbances) between the two groups (P = 0.025).

CONCLUSIONS

This study showed that pregnancy toxemia might have effects on hearing abilities.
Determination of perineural invasion preoperatively on radiographic images
Authors: Lee Kimberly J. , Abemayor Elliot , Sayre James , Bhuta Sunita , Kirsch Claudia
Published: July 2008

OBJECTIVE

Perineural invasion in head and neck cancers has important prognostic implications, and even if clinically silent, can be radiographically evident. This study analyzed the frequency of preoperative diagnosis, radiographic features, and importance of the preoperative diagnosis in treatment planning.

STUDY DESIGN

Radiographic studies of 38 patients with histopathologically proven perineural spread from head and neck cancer were retrospectively reviewed and compared with preoperative reports.

SUBJECTS AND METHODS

The percent agreement with pathology, kappa values, and 95 percent confidence intervals were determined for relevant nerves. Salient radiographic findings were compared with the contralateral normal side.

RESULTS

Preoperative agreement was less than 10 percent for all nerves, and retrospectively was 56 percent for the trigeminal nerve and 40 percent for the facial nerve. Radiographic features included neural thickening and enhancement, and foraminal widening.

CONCLUSION

Cancers of the head and neck can spread perineurally. Preoperative radiographic determination, although under‐reported, is imperative, because diagnosis impacts management and prognosis.
The expression of MMP‐2, MMP‐7, MMP‐9, and TIMP‐1 in chronic rhinosinusitis and nasal polyposis
Authors: Can Ilknur Haberal , Ceylan Kursat , Caydere Muzaffer , Samim Ethem Erdal , Ustun Huseyin , Karasoy Durdu Sertkaya
Published: July 2008

OBJECTIVES

To investigate the expression and clinical significance of MMP‐2, MMP‐7, MMP‐9, and TIMP‐1 in patients with nasal polyposis (NP) and chronic rhinosinusitis (CRS).

STUDY DESIGN

Prospective study.

SUBJECTS AND METHODS

This study involved 54 patients. There were three groups: nasal polyposis group, chronic rhinosinusitis group, and control group. Specimens were collected during endoscopic sinus surgery. Each sample was immunohistochemically examined.

RESULTS

Expression of MMP‐2 was found significantly increased in NP, whereas MMP‐7 expression was found significantly increased in CRS (P < 0.001). TIMP‐1 was significantly high in control group compared to CRS and NP (P < 0.001 and P = 0.002, respectively).

CONCLUSIONS

Different regulation type of activation of MMPs has been found in these two diseases. If MMP‐2 expression is intense in the mucosa, then this ends with polyp formation; if MMP‐7 expression is intense, it ends with CRS or stays as CRS.
Rhinitis symptoms and comorbidities in the United States: Burden of rhinitis in America survey
Authors: Derebery Jennifer , Meltzer Eli , Nathan Robert A. , Stang Paul E. , Campbell Ulka B. , Corrao Marlo , Stanford Richard
Published: July 2008

OBJECTIVE

To assess the burden of nasal symptoms in the United States (U.S.) and the comorbid conditions associated with nasal symptoms.

SUBJECTS AND METHODS

A self‐administered screening questionnaire and follow‐up survey was sent to targeted households from a representative sample of 15,000 households in the U.S. Subjects with comorbid asthma completed the Asthma Control Test (ACT).

RESULTS

Out of 7024 evaluable subjects who responded, 3831 subjects were classified as rhinitis “sufferers.” Individuals with active rhinitis symptoms were 1.5 to 4.5 times more likely to suffer from comorbid conditions including asthma, conjunctivitis, otitis media, sinusitis, eczema, food and insect bite allergies, migraine, and depression. Almost half of all respondents with moderate or severe rhinitis symptoms and comorbid asthma had poorly controlled asthma as defined by an ACT score of ≤19.

CONCLUSIONS

A strong relationship exists between rhinitis symptoms and various comorbidities, including asthma, in the U.S. population. Poorly controlled rhinitis contributes to the public health burden of rhinitis and asthma.
Decline and revitalization in post-communist urban context: A case of the Polish city—Gdansk
Authors: Polanska Dominika
Published: July 2008

This paper examines how different social, economic, historical and physical conditions coincide in the formation of space and processes of decline in the period of transformation in Poland. The focus lies on a specific residential area in the centre of the Polish city of Gdansk and the question why no improvements have been done in this particular area to stop its successive decline. It is among other things argued that clear urban policy together with improved urban planning and clear legislation on ownership are needed in order to improve conditions in this and other deprived areas of the city.
Appearance of a genetically-based pollution resistance in a marine gastropod, Nucella lapillus, in south-west Brittany: a new case of Dumpton syndrome
Authors: Huet M. , Le Goïc N. , Gibbs P.E.
Published: July 2008

Most neogastropod species exhibit masculinization of the female when subject to tributyltin (TBT) pollution (a process known as ‘imposex’). To date, the dog-whelk Nucella lapillus is seemingly unique in having a genetic deficiency (termed Dumpton syndrome or DS) that disrupts the development of normal male sex organs, its presence being readily recognizable by the underdevelopment, or non-development (aphally), of the penis, and incomplete formation (non-closure) of the vas deferens, causing a split prostate. In highly contaminated conditions, female carriers of DS can be identified by a lesser degree of masculinization (notably aphally): they escape sterilization caused by the advanced stages of imposex. To date, DS has only been reported in areas with high TBT pollution which induces sterilization of normal females (i.e. non DS-affected females). DS is now, for the first time, observed at some locations where present TBT levels are low and some normal females lack penis development. In such conditions it is not possible to discriminate normal from DS-affected females using aphally. As DS-affected females must be discarded from the calculation of the imposex bioindicators to monitor TBT pollution, indirect tools such as molecular probe are now needed to further survey those areas where DS and TBT pollution may interact as, for example, in south-west Brittany.
Planar shock waves in liquids produced by high-energy KrF laser: A technique for studying hydrodynamic instabilities
Authors: Zvorykin V.D. , Berthe L. , Boustie M. , Levchenko A.O. , Ustinovskii N.N.
Published: July 2008

The paper is devoted to research and development of a novel experimental technique—liquid-filled laser-driven shock tube (LST) for modeling of Rayleigh-Taylor (RT) and Richtmyer-Meshkov (RM) hydrodynamic instabilities development at the contact surface of two immiscible liquids under shock wave (SW) passage. 100-J, 100-ns KrF laser facility GARPUN has been used to irradiate some opaque liquids. A homogenizing focusing system combined multi-element prism raster and a lens to provide non-uniformity less than a few percents across a square 7 × 7-mm spot, laser intensities being varied in the range of q = 0.004–2 GW/cm2. Surface plasma blow-off produced a planar SW, which propagated into the liquid. SW amplitudes as high as 0.8 GPa weakly damping with increasing thickness were measured in dibutyl-phthalate (DBP), which volumetrically absorbed ultraviolet (UV) laser light. Nonlinear absorption coefficients and laser breakdown thresholds were measured for pure water and UV optical materials intended to confine plasma. Test bench experiments were performed to produce standing acoustic waves as initial perturbations at the interface between two immiscible liquids.
Influence of corner layers in the variational determination of bubble solutions of the constrained Allen–Cahn equation
Authors: JORGE M. C. , MINZONI A. A. , VARGAS C. A.
Published: July 2008

A steady-state bubble solution to the constrained mass conserving Allen–Cahn equation in a two-dimensional domain is constructed in the limit of small diffusivity. The solution is asymptotically constant inside a circle of radius rb centred at some unknown location x0 and has a sharp interface at the bubble radius that allows for a transition to a different asymptotically constant state outside the bubble. In a study by M. J. Ward (Metastable bubble solutions for the Allen–Cahn equation with mass conservation. SIAM J. Appl. Math. 56, 1996, 247–1279), the bubble centre was determined by a limiting solvability condition. The solution found by Ward suggests the existence of a corner type boundary layer where the normal derivative of the bubble solution readjusts to satisfy the no-flux condition at the boundary of the domain. This work is concerned with the details of the readjustment. A variational approach similar to the one of W. L. Kath, C. Knessl and B. J. Matkowsky (A variational approach to nonlinear singularly perturbed boundary-value problems. Stud. Appl. Math. 77, 1987, 61–88) shows the formation of a corner layer (for the derivative of the solution) which influences as a high-order correction the available determination of the bubble centre. This corner layer describes to leading order the readjustment of the level lines of the bubble to lines parallel to the boundary of the container; moreover, it provides to leading order a smooth solution across the corner layer.
On the diffusive wave approximation of the shallow water equations
Authors: ALONSO R. , SANTILLANA M. , DAWSON C.
Published: July 2008

In this paper, we study basic properties of the diffusive wave approximation of the shallow water equations (DSW). This equation is a doubly non-linear diffusion equation arising in shallow water flow models. It has been used as a model to simulate water flow driven mainly by gravitational forces and dominated by shear stress, that is, under uniform and fully developed turbulent flow conditions. The aim of this work is to present a survey of relevant results coming from the studies of doubly non-linear diffusion equations that can be applied to the DSW equation when topographic effects are ignored. In fact, we present proofs of the most relevant results existing in the literature using constructive techniques that directly lead to the implementation of numerical algorithms to obtain approximate solutions.
Biofluid mechanics of the human reproductive process: modelling of the complex interaction and pathway to the oocytes
Authors: Foo Jong Yong Abdiel , Lim Chu Sing
Published: July 2008

Recent revelations in the human reproductive process have fuelled much interest in this field of study. In particular, the once prevailing view of large numbers of ejaculated sperms racing towards the egg has been refuted recently. This is opposed to the current views derived from numerous clinical findings that state that only a very small number of sperms will ever enter the oviduct. It is believed that these few sperms must have been guided to make the long, tedious and obstructed journey to the egg. For a mature spermatozoon, its hyperactivated swimming motility upon capacitation plays an important role in the fertilization of a mature egg. Likewise, the female genital tract also provides guiding mechanisms to complement the survival of normal hydrodynamic profile sperms and thus promotes an eventual sperm–egg interaction. Understanding these mechanisms can be essential for the derivation of assisted conception techniques especially thosein vitro. With the aid of computational models and simulation, suitability and effectiveness of novel assisted conception methodology can be assessed, particularly for those yet to be ready for clinical trials. This review discusses the possible bioengineering models and the mechanisms by which human spermatozoa are guided to the egg.
Age, period and cohort effects on body weight and body mass index in adults: The Doetinchem Cohort Study
Authors: Nooyens Astrid CJ , Visscher Tommy LS , Verschuren WM Monique , Schuit A Jantine , Boshuizen Hendriek C , van Mechelen Willem , Seidell Jacob C
Published: July 2008

Objective

To study the development of body weight with ageing, in a general adult population, taking into account possible period and cohort effects.

Design

A prospective cohort study with 11 years of follow-up. At baseline and after 6 and 11 years, body weight and height were measured.

Setting

The Doetinchem Cohort Study, consisting of inhabitants of Doetinchem, a town in a rural area of The Netherlands.

Subjects

In total, 4070 healthy men and women aged 20–59 years at baseline.

Results

Increase in BMI with ageing was less profound based on cross-sectional data than based on longitudinal data. More recent-born cohorts had a higher BMI at a given age than cohorts who were born earlier. Increase in mean BMI with ageing was observed in all age groups and was similar for groups with a different educational level. Highest increase in BMI over 11 years was observed in the youngest group, aged 20–29 years at baseline (2·2 [95 % CL 2·0, 2·3] kg/m2), and lowest increase in the oldest group, aged 50–59 years at baseline (1·1 [1·0, 1·3] kg/m2).

Conclusions

Findings of the present study using longitudinal data suggest that increase in BMI with ageing is underestimated in all age groups by studying cross-sectional data only. Further, weight gain is present in all educational levels and does not stop at middle age.
Vitamin D Status of Socio-Economically Deprived Children in Kabul, Afghanistan
Authors: Manaseki-Holland  , Zulf Mughal  , Bhutta  , Qasem Shams
Published: July 2008

Background: Cultural, environmental, and diet-related factors were postulated to lead to a high prevalence of vitamin D deficiency in Kabul’s socioeconomically deprived children under 5 years of age. We investigated the prevalence of plasma 25-hydroxyvitamin D (25-OHD) deficiency in such a group. Methods: Children between 6 months and up to 5 years of age were randomly sampled in the Chindawal area of Kabul in January 2005. Plasma samples were frozen to below –20° C and 25(OH)D3 concentrations estimated by high-pressure liquid chromatography. Results: For all 107 children tested, the median plasma 25(OH)D concentration was 5 ng/mL with a range of 2–24 ng/mL; 73% had concentrations of < 8 ng/mL; 13 other samples were not analyzed due to insufficiency of plasma, staff, or technical problems. About 35 others approached either did not give consent or blood could not be obtained. Conclusions: This study was conducted in a high-risk population at a peak season for vitamin D deficiency. We conclude that this population of children living in Kabul to be at great risk of developing vitamin D deficiency, rickets, and other possible immunological effects of deficiency.
Methylcobalamin Inhibits Fibroblast Growth Factor-8 Stimulated Proliferation and Induces Apoptosis in Shionogi Carcinoma Cells
Authors: Goto  , Katayama  , Tanigaki  , Fushiki  , Nishizawa  , Nishizawa
Published: July 2008

SC-3 cells, an androgen-dependent mouse mammary carcinoma cell line, in response to androgen stimuli, induces the secretion of fibroblast growth factor (FGF-8), which in turn increases the proliferation of these cells. We have shown previously that methylcobalamin (MeCbl) decreases the levels of FGF-8 mRNA in SC-3 cells stimulated by testosterone, inhibiting the proliferation of SC-3 cells and inducing apoptosis. In the present study, we analyzed the effects of MeCbl on SC-3 cell proliferation in response to exogenous addition of FGF-8. Thymidine incorporation showed a significant decrease in SC-3 cells cultured with MeCbl. Immunocytochemistry for single-stranded DNA (ssDNA) and DNA fragmentation analysis demonstrated that MeCbl induced apoptosis in SC-3 cells, even in the presence of FGF-8. These results show that the addition of FGF-8 stimulates the proliferation of SC-3 cells under the androgen-depleted condition and that MeCbl might be able to interfere with FGF-8 action.
Erhebung von Essverhalten und Verhaltensauffälligkeiten bei Kindern und Jugendlichen
Authors: Thiels Cornelia , Pätel Johanna
Published: July 2008

Zusammenfassung: Fragestellung: Gibt es bei Kindern und Jugendlichen Zusammenhänge zwischen Body Mass Index und psychosozialen Problemen einschließlich essstörungstypischer Symptome? Methodik: 1057 Schüler im Alter von 10 bis 17 Jahren füllten den Youth Self-Report (YSR) und das Eating Disorder Inventory für Kinder (EDI-C) aus. Soziodemographische Daten, sowie Information über Körperlänge und Gewicht wurden ebenfalls erhoben. Ergebnisse: Untergewichtige Mädchen berichteten weniger Probleme als normalgewichtige. Mädchen mit Übergewicht erreichten höhere Werte als normalgewichtige auf sechs von elf EDI-C-Skalen (Schlankheitsstreben, Bulimie, Unzufriedenheit mit der Figur, Minderwertigkeitsgefühle, Misstrauen gegenüber anderen und Unsicherheit in der Wahrnehmung von Gefühlen) sowie auf den YSR-Skalen Ängstlich/Depressiv und Soziale Probleme. Ähnlich zeigten übergewichtige Jungen mehr soziale Probleme als normalgewichtige und höhere Werte auf denselben EDI-C-Skalen wie übergewichtige Mädchen mit Ausnahme von Misstrauen gegenüber anderen. Untergewichtige Jungen unterscheiden sich von normalgewichtigen im YSR durch vermehrte körperliche Beschwerden, im EDI-C dagegen auf keiner der Skalen signifikant. Schlussfolgerungen: Übergewichtige Kinder und Jugendliche leiden offenbar unter psychosozialen Problemen, einschließlich solcher, die für Essgestörte typisch sind. Daher bedürfen sie der Intervention nicht nur zur Vermeidung körperlicher Folgen von Übergewicht und Adipositas. Dabei sollte ihre Essstörungssymptomatik Berücksichtigung finden.