bluuebunny/crossref_metadata_2025_split huggingface dataset:
Temporally regulated delivery of VEGF in vitro and in vivo
Authors: Ennett Alessandra B. , Kaigler Darnell , Mooney David J. 
Published: June 2006

AbstractThe exposure duration and tissue distribution will likely dictate the success of vascular endothelial growth factor (VEGF) in therapeutic angiogenesis. We hypothesized that these variables can be regulated via the manner in which the VEGF is incorporated into polymer constructs (formed with a gas foaming technique) used for its delivery. VEGF was incorporated directly into poly(lactide‐co‐glycolide) (PLG) scaffolds or pre‐encapsulated in PLG microspheres used to fabricate scaffolds. Protein release kinetics and tissue distribution were determined using iodinated VEGF. VEGF was positioned predominantly adjacent to scaffold pores when incorporated directly and was released rapidly (40–60% in 5 days). Pre‐encapsulation led to the VEGF being more deeply embedded and resulted in a delayed release. Alterations in polymer composition, scaffold size, and matrix composition generated minor variations in release kinetics. In vivo, the released VEGF generated local protein concentrations above 10 ng/mL at distances up to 2 cm from the implant site for the 21 days of the experiment, with negligible release into the systemic circulation, and significantly enhanced local angiogenesis. These data indicate that VEGF can be administered in a sustained and localized fashion in vivo, and the timing of VEGF delivery can be altered with the mechanism of incorporation into polymer scaffolds used for its delivery. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res, 2006
Nickel and vanadium metal ions induce apoptosis of T‐lymphocyte Jurkat cells
Authors: Au Angela , Ha Jinny , Hernandez Mauro , Polotsky Anna , Hungerford David S. , Frondoza Carmelita G. 
Published: June 2006

AbstractMetal alloys are used as prosthetic components in the orthopaedic and dental field. However, there is growing concern over the reported leaching of metal ions from implants. Ions released from metals have been thought to be associated with local immune dysfunction, inflammation, and tissue cell death. The objective of our study was to investigate whether nickel(II) and vanadium(V), present at a smaller percentage in most alloys, are cytotoxic to T‐lymphocyte cell models. Jurkat T cells possess characteristics similar to human T‐lymphocytes and proliferate at a faster rate. Jurkat T cells were incubated with control media alone or with concentrations of 1, 10, and 100 μg/mL of Ni(II) or V(V) for 24 h. Both types of metal ions reduced cell viability and proliferation in a dose‐dependent manner. Ni(II) at 10 μg/mL and V(V) at 100 μg/mL activated Caspase‐3 expression. Hoechst 33258 staining and transmission electron microscopy revealed chromatin condensation, as well as nuclear blebbing and fragmentation. Induction of DNA fragmentation by Ni(II) at 100 μg/mL was also indicated by agarose electrophoresis. Our observations indicate that Ni and V ions kill T cells via apoptotic and nonapoptotic pathways. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res, 2006
Electronic structure of iron(II)–porphyrin nitroxyl complexes: Molecular mechanism of fungal nitric oxide reductase (P450nor)
Authors: Lehnert Nicolai , Praneeth V. K. K. , Paulat Florian 
Published: June 2006

AbstractDensity functional calculations are employed to investigate key intermediates of the catalytic cycle of fungal nitric oxide reductase (P450nor). The formal Fe(II)–nitroxyl species Fe(II)NO/(−) can principally exist in the two spin‐states S = 0 and S = 1. In the S = 0 case, a very covalent FeNO σ bond is present, which leads to an electronic structure description that is actually intermediate between Fe(I)NO and Fe(II)NO−. In contrast, the S = 1 case shows a ferrous Fe(II)NO complex with the extra electron being stored in the π system of the porphyrin ligand. Importantly, the Fe(II)NO/(−) species are very basic. The electronic structures and spectroscopic properties of the corresponding N‐ and O‐protonated forms are very different, and unequivocally show that the Mb–HNO adduct (Mb‐Myoglobin) prepared by farmer and coworkers is in fact N‐protonated. The presence of an axial thiolate ligand enables a second protonation leading to the corresponding Fe(IV)NHOH− species, which is identified with the catalytically active intermediate I of P450nor. This species reacts with a second molecule of NO by initial electron transfer from NO to Fe(IV) followed by addition of NO+ forming an NN bond. This is accompanied by an energetically very favorable intramolecular proton transfer leading to the generation of a quite stable Fe(III)N(OH)(NOH) complex. This way, the enzyme is able to produce dimerized HNO under very controlled conditions and to prevent loss of this ligand from Fe(III). The energetically disfavoured tautomer Fe(III)N(OH2)(NO) is the catalytically productive species that spontaneously cleaves the NOH2 bond forming N2O and H2O in a highly exergonic reaction. © 2006 Wiley Periodicals, Inc. J Comput Chem 27: 1338–1351, 2006
On the O2 binding of Fe–porphyrin, Fe–porphycene, and Fe–corrphycene complexes
Authors: Nakashima Hiroyuki , Hasegawa Jun‐ya , Nakatsuji Hiroshi 
Published: June 2006

AbstractBased on our previous study for the O2 binding of the Fe–Por complex, this study investigates the O2 binding mechanism in the Fe–porphyrin isomers, Fe–porphycene (FePc), and Fe–corrphycene (FeCor) complexes. By calculating the potential energy surface of the O2 binding, the present study explains the reason for the dramatic increase of O2 affinities observed in the FePc complex. In the case of FeCor–O2, the O2 binding process includes the intersystem crossing from a triplet to singlet state, as in the FePor–O2 complex. However, FePc–O2 uses only a singlet surface. This is because the ground state of the FePc complex in the deoxy state is a triplet state, while those of FePor and FeCor are a quintet state. Such difference originates from character of the SOMO. We estimated an equilibrium constant for the O2 binding that reasonably reproduced the trend observed in the experiments. © 2006 Wiley Periodicals, Inc. J Comput Chem 27: 1363–1372, 2006
Quantum chemistry applied to the mechanisms of transition metal containing enzymes—Cytochrome c oxidase, a particularly challenging case
Authors: Blomberg Margareta R. A. , Siegbahn Per E. M. 
Published: June 2006

AbstractThe Density functional theory (B3LYP) has been used to study the mechanisms of OO bond cleavage and proton pumping in cytochrome c oxidase. To understand how the energy from the exergonic reduction of molecular oxygen is used to pump protons across the mitochondrial membrane, the energetics of all steps in the catalytic cycle have to be evaluated. For this purpose, models have to be designed that can accurately reproduce relative redox potentials and pKa values within the active site. The present study shows that it is possible to construct such models and to calculate energy profiles which, to a large extent, agree with experimental information. However, the energy profiles point out a problem with an unbalanced partitioning of the energy between the reductive and oxidative half cycles, which is in disagreement with the experimental observation that the proton pumping is evenly distributed between the two half cycles. A conclusion from the present study is, therefore, that something is probably still missing in the modeling of the active site. © 2006 Wiley Periodicals, Inc. J Comput Chem 27: 1373–1384, 2006
Do large dogs die young?
Authors: Galis Frietson , Van Der Sluijs Inke , Van Dooren Tom J.M. , Metz Johan A.J. , Nussbaumer Marc 
Published: June 2006

AbstractIn most animal taxa, longevity increases with body size across species, as predicted by the oxidative stress theory of aging. In contrast, in within‐species comparisons of mammals and especially domestic dogs (e.g. Patronek et al.,'97; Michell,'99; Egenvall et al.,2000; Speakman et al.,2003), longevity decreases with body size.We explore two datasets for dogs and find support for a negative relationship between size and longevity if we consider variation across breeds. Within breeds, however, the relationship is not negative and is slightly, but significantly, positive in the larger of the two datasets. The negative across‐breed relationship is probably the consequence of short life spans in large breeds. Artificial selection for extremely high growth rates in large breeds appears to have led to developmental diseases that seriously diminish longevity.J. Exp. Zool. (Mol. Dev. Evol.) 306B, 2006. © 2006 Wiley‐Liss, Inc.
Lectin‐binding pattern as tool to identify and enrich specific primary testis cells of the tilapia (Oreochromis niloticus) and medaka (Oryzias latipes)
Authors: Tokalov Sergey V. , Gutzeit Herwig O. 
Published: June 2006

AbstractCell type‐specific lectin binding is a useful tool for the analysis of developing systems. We describe the binding pattern of 21 different fluorescein isothiocyanate (FITC)‐labelled lectins to the testis of two model teleost species, the medaka (Oryzias latipes) and the tilapia (Oreochromis niloticus). The analysis of the binding pattern was carried out on tissue sections (medaka and tilapia) and using primary culture cells (only tilapia). Lectin binding was studied by confocal microscopy and for histological analysis some sections were, in addition, stained with bodipy to gain additional information concerning the cytological organization of the cystic mode of spermatogenesis in fish. The observed differences in lectin staining of different cell types in primary cultures were quantified by flow cytometry. Only few lectins bound specifically to haploid cells while the reaction to diploid or tetraploid cells was generally stronger. However, the extracellular material around the haploid spermatids and spermatozoa in spermatocysts showed a strong staining reaction with several lectins (e.g., Phaseolus vulgaris Erythro agglutinin). The apparent differences in the cellular lectin‐binding pattern can be used to identify particular cell types, to monitor their differentiation in vitro or to enrich particular cell types from heterogeneous cultures using magnetic beads coated with anti‐FITC antibodies. Using the latter approach, we show that it is possible to enrich for gonial cells and at the same time deplete the preparation for haploid cells and Sertoli cells. J. Exp. Zool. (Mol. Dev. Evol.) 306B, 2006. © 2006 Wiley‐Liss, Inc.
Distinguishing geometric graphs
Authors: Albertson Michael O. , Boutin Debra L. 
Published: June 2006

AbstractWe begin the study of distinguishing geometric graphs. Let G be a geometric graph. An automorphism of the underlying graph that preserves both crossings and noncrossings is called a geometric automorphism. A labeling, f: V(G) → {1, 2, … , r}, is said to be r‐distinguishing if no nontrivial geometric automorphism preserves the labels. The distinguishing number of G is the minimum r such that G has an r‐distinguishing labeling. We show that when Kn is not the nonconvex K4, it can be 3‐distinguished. Furthermore, when n ≥ 6, there is a Kn that can be 1‐distinguished. For n ≥ 4, K2,n can realize any distinguishing number between 1 and n inclusive. Finally, we show that every K3,3 can be 2‐distinguished. We also offer several open questions. © 2006 Wiley Periodicals, Inc. J Graph Theory 53: 135–150, 2006
The comparison of pyrosequencing molecular Gram stain, culture, and conventional Gram stain for diagnosing orthopaedic infections
Authors: Kobayashi Naomi , Bauer Thomas W. , Tuohy Marion J. , Lieberman Isador H. , Krebs Viktor , Togawa Daisuke , Fujishiro Takaaki , Procop Gary W. 
Published: June 2006

AbstractWe have developed a combined real‐time PCR and pyrosequencing assay that successfully differentiated the vast majority of gram‐positive and gram‐negative bacteria when bacterial isolates were tested. The purpose of this study was to evaluate this assay on clinical specimens obtained from orthopedic surgeries, and to prospectively compare the results of “molecular Gram stain” with culture and conventional direct Gram stain. Forty‐five surgical specimens were obtained from patients who underwent orthopedic surgery procedures. The DNA was extracted and a set of broad‐range PCR primers that targeted a part of the 16S rDNA gene was used for pan‐bacterial PCR. The amplicons were submitted for pyrosequencing and the resulting molecular Gram stain characteristics were recorded. Culture and direct Gram staining were performed using standard methods for all cases. Surgical specimens were reviewed histologically for all cases that had a discrepancy between culture and molecular results. There was an 86.7% (39/45) agreement between the traditional and molecular methods. In 12/14 (85.7%) culture‐proven cases of bacterial infection, molecular Gram stain characteristics were in agreement with the culture results, while the conventional Gram stain result was in agreement only for five cases (35.7%). In the 31 culture negative cases, 27 cases were also PCR negative, whereas 4 were PCR positive. Three of these were characterized as gram negative and one as gram positive by this molecular method. Molecular determination of the Gram stain characteristics of bacteria that cause orthopedic infections may be achieved, in most instances, by this method. Further studies are necessary to understand the clinical importance of PCR‐positive/culture‐negative results. © 2006 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 24:1641–1649, 2006
Mesenchymal transformation in epithelial ovarian tumor cells expressing epidermal growth factor receptor variant III
Authors: Zeineldin Reema , Rosenberg Martina , Ortega Dominic , Buhr Christian , Chavez Miquella G. , Stack M. Sharon , Kusewitt Donna F. , Hudson Laurie G. 
Published: June 2006

AbstractOverexpression of the epidermal growth factor (EGF) receptor occurs frequently in ovarian cancer and is associated with poor patient prognosis. A constitutively active mutant EGF receptor termed variant III (EGFRvIII) has been detected at a high frequency in many human tumors, including those of the ovary. To identify the consequences of EGFRvIII expression in ovarian tumor cells, we introduced EGFRvIII into the epithelial ovarian cancer cell line (OVCA 433). The EGFRvIII‐transfected cells displayed a dissociated, motile phenotype and fibroblastic morphology. The EGFRvIII‐dependent phenotype was comparable to that observed in EGF‐stimulated parental OVCA 433 cultures and required the catalytic activity of the mutant receptor. Disruption of adherens and desmosomal junctions in EGFRvIII expressing cells was evident by immunofluorescent detection of specific junctional components. In addition, Western blot analysis confirmed decreased levels of cellular plakoglobin and β‐catenin in EGFRvIII‐expressing cells, and E‐cadherin protein and mRNA were nearly absent. The loss of E‐cadherin was accompanied by decreased expression of additional ovarian epithelial markers, including keratins 7, 8, and 18 and mucins 1 and 4. In contrast, the mesenchymal markers N‐cadherin and vimentin were elevated in EGFRvIII expressing cells. Overall, the switch in cadherins from E‐cadherin to N‐cadherin, coupled with gain of vimentin expression and loss of the epithelial keratins and mucins typically expressed in well‐differentiated epithelial ovarian carcinomas, are consistent with transition to a mesenchymal phenotype as an outcome of EGFRvIII expression. These findings suggest that EGFRvIII expression may regulate phenotypic plasticity in ovarian cancer and thereby contribute to more aggressive disease. © 2006 Wiley‐Liss, Inc.
One‐electron properties using a CI method based on multiple Hartree–Fock solutions
Authors: Malbouisson L. A. C. , Martins M. G. R. , Makiuchi N. 
Published: June 2006

AbstractA multi‐reference configuration interaction (CI) method based on multiple Hartree–Fock (HF) solutions is applied to study the permanent dipole moment of the LiH, BH, FH, and H2O systems with the minimal atomic basis. The LiH was also calculated with the double‐zeta atomic basis. This method uses several HF solutions as references to expand the state functions. For each one of the systems studied, several HF solutions were obtained in the appropriate point and spin symmetry classes, i.e., 1Σ+ and 1A1. With each of these solutions is generated a distinct basis of the same full CI space. The set of these bases is a system of generators of the full CI space and the multi‐reference HF (MRHF) bases are built mixing configuration state functions (CSFs) originated from distinct HF solutions. © 2006 Wiley Periodicals, Inc. Int J Quantum Chem, 2006
Theoretical study of molecular and electronic structure of 2‐Se‐(2‐methyl‐2‐propenyl)‐1‐benzoic acid
Authors: Hameed Ali Jameel , Jalbout Abraham F. , Trzaskowski Bartosz 
Published: June 2006

AbstractA theoretical study of 2‐Se‐(2‐methyl‐2‐propenyl)‐1‐benzoic acid was carried out to investigate the molecular and electronic structure of this molecule, using the B3LYP density functional theory (DFT) method with the 6‐311+G** basis set. The optimized geometry of the molecule was obtained for the ortho, meta, and para isomers of the complex. In addition, the theoretical vibrational spectrum is presented, and thermal corrections in the limit of 100–1,000 K are discussed using the Shomate thermodynamic equations. © 2006 Wiley Periodicals, Inc. Int J Quantum Chem, 2007
Closure vs. nonclosure of the peritoneum at cesarean delivery
Authors: Yiyang Zhu , Qunxi Cai , Weiling Wu 
Published: June 2006

ObjectiveTo compare the frequency and severity of celiac adhesions following cesarean sections performed with and without closure of the parietal and visceral peritoneum.MethodsA retrospective cohort study involved 612 women who underwent their second lower‐segment transverse cesarean section.ResultsNonclosure of the parietal peritoneum at the time of the first cesarean section was associated with significantly more visceral adhesions than closure (16.2% vs. 8.1%; P = 0.003), and closure of the visceral peritoneum had a similar effect (16.1% vs. 6.7%; P = 0.02). However, the difference in rates of severe adhesions was not statistically significant (12.9% vs. 17.6%; P = 0.12). After controlling for confounding variables, it was found that closure of the parietal peritoneum reduced the rate of visceral adhesions 2.7‐fold. Trial of labor before and fever after surgery increased the risk of severe adhesions 6.1‐fold and 5.6‐fold, respectively.ConclusionNonclosure of the peritoneum at primary cesarean section is associated with a significantly increased risk of visceral adhesions.
Hospital Emergency Care Teams: our solution to out of hours emergency care
Authors: Carberry Martin 
Published: June 2006

ABSTRACTThe implementation of the European Working Time Directive and the compulsory reduction in junior doctors hours provided the main driver and background for this project. The project aim was to implement Hospital Emergency Care Teams (HECT) on three District General Hospitals (DGHs) to provide emergency out‐of‐hours care. The project strategy centred on the recruitment, training and preparation of critical care nurses to undertake advanced assessment roles. Methods used to monitor and evaluate activity include the use of innovative hand‐held computers. Main outcomes include, the conclusion that a multidisciplinary HECT of five could manage the overnight workload and level of acuity in a DGH of 420–500 beds, and that critical care nursing staff can be prepared for advanced supporting roles. Experiences gained provide valuable learning that could be used to influence similar projects. Implications for practice include the development of a national framework to inform areas such as multidisciplinary competency‐based education and training. Scientific evidence is required to evaluate the effect of HECT on hospital mortality and morbidity and quantify the staff, inpatient experiences.
Transoesophageal echocardiography: a useful tool to diagnose entrapment of pulmonary artery catheter
Authors: Rupert E. , Paul A. , Mukherji J. 
Published: June 2006

SummaryPlacement of a pulmonary artery catheter during cardiac surgery is associated with various complications, one of which is entrapment. On the day following surgery unusual resistance was encountered while attempting to remove a pulmonary artery catheter from a patient who had undergone coronary artery bypass grafting. Entrapment of the catheter was confirmed by transoesophageal echocardiography, which demonstrated invagination of the free wall of the pulmonary trunk on gentle traction on the pulmonary artery catheter. Surgical exploration revealed that the catheter was transfixed by the suture used to close the pulmonary artery vent site. Surgical re‐exploration and other potential complications related to catheter retrieval can be avoided if catheter entrapment is diagnosed intra‐operatively. We suggest that a high index of clinical suspicion along with the use of intra‐operative transoesophageal echocardiography is considered in situations where catheter entrapment is a possibility.
The circulatory responses to fibreoptic intubation: a comparison of oral and nasal routes
Authors: Xue F. S. , Li C. W. , Sun H. T. , Liu K. P. , Zhang G. H. , Xu Y. C. , Liu Y. , Yu L. 
Published: June 2006

SummaryThe circulatory responses to fibreoptic intubation under general anaesthesia were studied in 60 adult female patients who were randomly assigned to receive either the oral or nasal route for insertion. Non‐invasive blood pressure and heart rate were recorded before anaesthesia induction (baseline values), immediately after anaesthesia induction (post‐induction values), at intubation and every minute for a further 5 min. The product of heart rate and systolic blood pressure (rate pressure product) at every time point was also calculated. The results showed that both fibreoptic orotracheal intubation and fibreoptic nasotracheal intubation resulted in significant increases in blood pressure, heart rate and rate pressure product compared to baseline and post‐induction values. The times required to reach the maximum values of systolic blood pressure and heart rate were significantly longer in the fibreoptic nasotracheal intubation group than in the fibreoptic orotracheal intubation group. There were no significant differences between the two groups in blood pressure, heart rate and rate pressure product at any measuring point, or in the maximum values during observation. The time required for recovery of systolic blood pressure to the post‐induction value was not significantly different between the two groups, but the time required for recovery of heart rate to post‐induction value was significantly longer in the fibreoptic orotracheal intubation group than in the fibreoptic nasotracheal intubation group. It was concluded that both fibreoptic orotracheal and fibreoptic nasotracheal intubations could cause a similar magnitude of circulatory responses in general anaesthetised, female adults, but the tachycardic response to fibreoptic orotracheal intubation lasted longer than that to fibreoptic nasotracheal intubation.