bluuebunny/crossref_metadata_2025 huggingface dataset:
Cyclin D1b variant promotes cell invasiveness independent of binding to CDK4 in human bladder cancer cells
Authors: Kim Chul Jang , Nishi Kayoko , Isono Takahiro , Okuyama Yusuke , Tambe Yukihiro , Okada Yusaku , Inoue Hirokazu
Published: May 2009

Alternative splicing in the cyclin D1 gene produces cyclin D1b variant which lacks a C‐terminal region containing the threonine‐286 (T286) phosphorylation site required for nuclear export. We have shown that the expression of the cyclin D1b variant is detected in about 60% of human bladder cancer tissues (15/26) and cell lines (3/5). To examine the role of the cyclin D1b variant in bladder carcinogenesis, we introduced wild‐type cyclin D1a, cyclin D1b variant or mutant cyclin D1‐T286A cDNAs into a human bladder cancer cell line, SBT991, in which cyclin D1b transcript was not expressed, and compared their oncogenic activities. Ectopic expression of cyclin D1b promoted cell invasiveness and anchorage‐independent growth of the cancer cells. On the other hand, cyclin D1‐T286A enhanced anchorage‐independent growth, but did not promote cell invasiveness. The amount of nuclear‐localized cyclin D1b and cyclin D1‐T286A was higher than that of nuclear‐localized cyclin D1a. In addition, introduction of siRNA specific for cyclin D1b into cells of the T24 bladder cancer cell line, in which cyclin D1b transcript was expressed, significantly suppressed cell invasiveness. Immunoprecipitation analysis revealed that cyclin D1a and cyclin D1‐T286A could bind to cyclin‐dependent kinase 4 (CDK4) but cyclin D1b has lost its capacity to associate with CDK4. Unlike cyclin D1a and cyclin D1‐T286A, expression of cyclin D1b did not enhance phosphorylation of Rb protein in SBT991 cells. These results indicate that cyclin D1b promotes cell invasiveness independent of binding to CDK4 to enhance Rb phosphorylation. Mol. Carcinog. © 2009 Wiley‐Liss, Inc.
Urothelial overexpression of insulin‐like growth factor‐1 increases susceptibility to p‐cresidine‐induced bladder carcinogenesis in transgenic mice
Authors: Hursting Stephen D. , Perkins Susan N. , Lavigne Jackie A. , Beltran Linda , Haines Diana C. , Hill Heather L. , Alvord W. Gregory , Barrett J. Carl , DiGiovanni John
Published: May 2009

To establish a role for insulin‐like growth factor‐1 (IGF‐1) in bladder cancer susceptibility, we tested the effect of p‐cresidine, a potent bladder carcinogen, in transgenic (TG) mice with human IGF‐1 expression in the bladder driven by the bovine keratin 5 promoter (referred to as BK5.IGF‐1 TG mice). Indomethacin was also tested to determine if the cyclooxygenase (COX) pathway is a target for bladder cancer prevention in this model. Thirty‐three female BK5.IGF‐1 TG mice and 29 female nontransgenic littermates were randomized to the following treatments: (1) AIN‐76A diet; (2) AIN‐76A diet with 0.5% p‐cresidine; or (3) AIN‐76A diet with 0.5% p‐cresidine + 0.00075% indomethacin. BK5.IGF‐1 TG mice, with twofold greater total serum IGF‐1 than nontransgenic mice, exhibited greatly increased susceptibility to p‐cresidine‐induced bladder tumors compared to nontransgenic mice. The most common type of bladder tumor in the BK5.IGF‐1 TG mice was transitional cell carcinoma, which is the predominant type of bladder cancer observed in developed countries. Indomethacin inhibition of bladder tumor development in BK5.IGF‐1 TG mice was not statistically significant. These results present further evidence for the role of IGF‐1 in bladder cancer progression. In addition, these transgenic mice provide a useful model for studying the role of the IGF‐1 pathway in bladder carcinogenesis and its prevention. © 2009 Wiley‐Liss, Inc.
Bioaccessibility, biotransformation, and transport of α‐mangostin from Garcinia mangostana (Mangosteen) using simulated digestion and Caco‐2 human intestinal cells
Authors: Bumrungpert Akkarach , Kalpravidh Ruchaneekorn W. , Suksamrarn Sunit , Chaivisuthangkura Apinya , Chitchumroonchokchai Chureeporn , Failla Mark L.
Published: May 2009

α‐ and γ‐Mangostin are the most abundant prenylated xanthones present in the fruit of the mangosteen tree. These compounds have been reported to possess numerous bioactivities that have provided the impetus for use of mangosteen products as nutraceuticals and in functional foods and dietary supplements. The health‐promoting benefits of mangosteen are dependent on delivery of the xanthones to target tissues. Here, we used simulated digestion and Caco‐2 cells to investigate the digestive stability, bioaccessibility, and intestinal cell transport of α‐ and γ‐ mangostin. Recovery of α‐ and γ‐mangostin after simulated digestion of pericarp and fruit pulp exceeded 90%. Transfer of α‐ and γ‐mangostin to the aqueous fraction during simulated digestion was efficient (65–74%) and dependent on bile salts suggesting that micellarization is required for optimal bioaccessibility of xanthones. Cell uptake of xanthones from micelles was dose dependent and intracellular concentrations were maximum by 1 h. Both free and phase II metabolites of α‐mangostin were transported in the basolateral compartment and metabolites also effluxed into the apical chamber. Transepithelial transport of α‐mangostin was increased during prandial‐like compared to fasted conditions suggesting that absorption is enhanced by dietary fat.
Yoghurt impacts on the excretion of phenolic acids derived from colonic breakdown of orange juice flavanones in humans
Authors: Roowi Suri , Mullen William , Edwards Christine A. , Crozier Alan
Published: May 2009

Human urine was collected over a 24 h period after the consumption of 250 mL of (i) water, (ii) orange juice, and (iii) orange juice plus 150 mL of full fat natural yoghurt. The orange juice contained 168 μmol of hesperetin‐7‐O‐rutinoside and 18 μmol of naringenin‐7‐O‐rutinoside. GC‐MS analysis of the urine identified nine phenolic acids, five of which, 3‐hydroxyphenylacetic acid, 3‐hydroxyphenylhydracrylic acid, dihydroferulic acid, 3‐methoxy‐4‐hydroxyphenylhydracrylic acid and 3‐hydroxyhippuric acid, were associated with orange juice consumption indicating that they were derived from colonic catabolism of hesperetin‐7‐O‐rutinoside. The overall 0–24 h excretion of the five phenolic acids was 6.7 ± 1.8 μmol after drinking water and this increased significantly (p < 0.05) to 62 ± 18 μmol, equivalent to 37% of the ingested flavanones, following orange juice consumption. When the orange juice was ingested with yoghurt excretion fell back markedly to 9.3 ± 4.4 μmol. This was not due to a difference in mouth to caecum transit time, as measured with breath hydrogen production, though possibly there may have been a slowing of the bulk of the meal reaching the large intestine which may then have altered the catabolism of the flavanones to phenolic acids by the colonic microbiota.
Bilberry and its main constituents have neuroprotective effects against retinal neuronal damagein vitroandin vivo
Authors: Matsunaga Nozomu , Imai Shunsuke , Inokuchi Yuta , Shimazawa Masamitsu , Yokota Shigeru , Araki Yoko , Hara Hideaki
Published: May 2009

Our aim was to determine whether aVaccinium myrtillus(bilberry) anthocyanoside (VMA) and/or its main anthocyanidin constituents (cyanidin, delphinidin, and malvidin) can protect retinal ganglion cells (RGCs) against retinal damagein vitroandin vivo. In RGC cultures (RGC‐5, a rat ganglion cell‐line transformed using E1A virus)in vitro, cell damage and radical activation were induced by 3‐(4‐morpholinyl) sydnonimine hydrochloride (SIN‐1, a peroxynitrite donor). Cell viability was measured using a water‐soluble tetrazolium salt assay. Intracellular radical activation within RGC‐5 cells was evaluated using 5‐(and‐6)‐chloromethyl‐2,7‐dichlorodihydrofluorescein diacetate acetyl ester (CM‐H2DCFDA). Lipid peroxidation was assessed using the supernatant fraction of mouse forebrain homogenates. In micein vivo, we evaluated the effects of VMA onN‐methyl‐D‐aspartic acid (NMDA)‐induced retinal damage using hematoxylin‐eosin and terminal deoxynucleotidyl transferase‐mediated dUTP nick‐end labeling (TUNEL) stainings. VMA and all three anthocyanidins (i) significantly inhibited SIN‐1‐induced neurotoxicity and radical activation in RGC‐5, (ii) concentration‐dependently inhibited lipid peroxidation in mouse forebrain homogenates. Intravitreously injected VMA significantly inhibited the NMDA‐induced morphological retinal damage and increase in TUNEL‐positive cells in the ganglion cell layer. Thus, VMA and its anthocyanidins have neuroprotective effects (exerted at least in partviaan anti‐oxidation mechanism) in thesein vitroandin vivomodels of retinal diseases.
Synthesis and properties of photo‐functional hyperbranched polymers
Authors: Nishikubo Tadatomi , Kudo Hiroto , Maruyama Ken
Published: May 2009

Since dendritic polymers have excellent characteristic physical properties such as low viscosity, good solubility, and many functional groups, compared with corresponding linear polymers, they have been of great interest in the field of polymer chemistry. Among them, hyperbranched polymers have great possibility as high performance and new photo‐curable polymers and oligomers in chemical industry. In this paper, we report the synthesis and photochemical reaction of certain hyperbranched polymers such as hyperbranched epoxy‐methacrylate, hyperbranched oxetane‐methacrylate, and hyperbranched polyurethane‐methacrylate, and some physical properties of the resulting cured films. Copyright © 2009 John Wiley & Sons, Ltd.
Microfluidic chip fabrication using hot embossing and thermal bonding of COP
Authors: Pemg Boe‐Yu , Wu Chih‐Wei , Shen Yung‐Kang , Lin Yi
Published: May 2009

The application of silicon mold inserts by micro‐hot embossing molding has been explored in microfluidic chip fabrication. For the mold insert, this study employed an SU‐8 photoresist to coat the silicon wafer. Ultraviolet light was then used to expose the pattern on the SU‐8 photoresist surface. This study replicates the microstructure of the silicon mold insert by micro‐hot embossing molding. Different processing parameters (embossing temperature, embossing pressure, embossing time, and de‐molding temperature) for the cycle‐olefin polymer (COP) film of microfluidic chips are evaluated. The results showed that the most important parameter for replication of molded microfluidic chip is embossing temperature. De‐molding temperature is the most important parameter for surface roughness of the molded microfluidic chip. The microchannel is bonded with a cover by thermal bonding processing to form the sealed microfluidic chip. The bonding temperature is the most important factor in the bonding strength of the sealed microfluidic chip. Copyright © 2009 John Wiley & Sons, Ltd.
Testicular stem cells for fertility preservation: Preclinical studies on male germ cell transplantation and testicular grafting
Authors: Schlatt Stefan , Ehmcke Jens , Jahnukainen Kirsi
Published: May 2009

Spermatogonial stem cells open novel strategies for preservation of testicular tissue and fertility preservation in boys and men exposed to gonadotoxic therapies. This review provides an update on the physiology of spermatogonial stem cells in rodent and primate testes. Species‐specific differences must be considered when new technologies on testicular stem cells are considered. Germ cell transplantation is presented as one novel and promising strategy. Whereas this technique has become an important research tool in rodents, a clinical application must still be regarded as experimental and many aspects of the procedure need to be optimized prior to a safe and efficient clinical application in men. Testicular grafting opens another exciting strategy for fertility preservation. Autologous and xenologous transfer of immature tissue revealed a high regenerative potential of immature testicular tissue. Grafting was applied in rodents and primates and resulted in the generation of sperm. Further research is needed before an application in humans can be considered safe and efficient. Despite the current limitations in regard to the generation of sperm from cryopreserved male germline cells and tissues, protocols for cryopreservation of testicular tissue are available and reveal a promising outcome. Since future improvements of germ cell transplantation and grafting approaches can be assumed, bioptic retrieval and cryopreservation of testicular tissue fragments should be performed in oncological patients at high risk of fertility loss since this is their only option to maintain their fertility potential. Pediatr Blood Cancer 2009;53:274–280. © 2009 Wiley‐Liss, Inc.
Off‐label use of rFVIIa in children with excessive bleeding: A consecutive study of 153 off‐label uses in 139 children
Authors: Young Guy , Wicklund Brian , Neff Philip , Johnson Chelsea , Nugent Diane J.
Published: May 2009

Background

Recombinant factor VIIa is a general hemostatic agent. Randomized trials have demonstrated effectiveness in adults; however, data in children are confined to case reports and series subject to publication bias.

Procedures

A consecutive cohort of children treated with rFVIIa was identified via inspection of pharmacy records. Data collected included demographic data, underlying disorders, reason for rFVIIa use, dosing, thrombotic events, and mortality. Efficacy was scored subjectively on a 3‐point scale (complete, partial, or no response) and supported by a measurement of transfusion of red cells, platelets, fresh frozen plasma, and cryoprecipitate in the 3 days prior to and following use of rFVIIa. Patients with hemophilia and congenital factor VII deficiency were excluded.

Results

Sixty‐five percent had a complete response and 26% had a partial response. Following treatment, there was a mean reduction in transfusions of 14.2 ml/kg for red blood cells, 10.9 ml/kg for platelets, 9 ml/kg for fresh frozen plasma, and 4.6 ml/kg for cryoprecipitate. Thrombosis occurred in 4.3% of patients with the highest rate being in neonates (17.6%).

Conclusions

rFVIIa is an effective general hemostatic agent for management of excessive bleeding in children and that with the exception of neonates has excellent safety. Pediatr Blood Cancer 2009;53:179–183. © 2009 Wiley‐Liss, Inc.
Splenic infarction and subsequent splenic rupture in a patient with paroxysmal nocturnal hemoglobinuria and heparin‐induced thrombocytopenia
Authors: Magnan Heather , Kayton Mark L. , DiMichele Donna M. , Araten David J. , Kernan Nancy A. , Boulad Farid
Published: May 2009

We describe a patient with paroxysmal nocturnal hemoglobinuria (PNH) and no previous history of thrombosis who presented with hepatic venous thromboses and subsequently developed splenic infarction and rupture requiring splenectomy while on anticoagulation therapy for the hepatic thromboses. The patient's anticoagulation was complicated by heparin‐induced thrombocytopenia (HIT) highlighting the unique management challenge presented by PNH in combination with HIT. Pediatr Blood Cancer 2009;53:472–474. © 2009 Wiley‐Liss, Inc.
Dyskeratosis congenita: The first NIH clinical research workshop
Authors: Savage Sharon A. , Dokal Inderjeet , Armanios Mary , Aubert Geraldine , Cowen Edward W. , Domingo Demetrio L. , Giri Neelam , Greene Mark H. , Orchard Paul J. , Tolar Jakub , Tsilou Ekaterini , Van Waes Carter , Wong Judy M.Y. , Young Neal S. , Alter Blanche P.
Published: May 2009

Dyskeratosis congenita (DC) is a heterogeneous inherited bone marrow failure syndrome, characterized by abnormally short telomeres and mutations in telomere biology genes. The spectrum of telomere biology disorders is growing and the clinical management of these patients is complex. A DC‐specific workshop was held at the NIH on September 19, 2008; participants included physicians, patients with DC, their family members, and representatives from other support groups. Data from the UK's DC Registry and the NCI's DC cohort were described. Updates on the function of the known DC genes were presented. Clinical aspects discussed included androgen therapy, stem cell transplant, cancer risk, and cancer screening. Families with DC met for the first time and formed a family support group (http://www.dcoutreach.com/). Ongoing, open collaboration between the clinical, scientific, and family communities is required for continued improvement in our understanding of DC and the clinical consequences of telomeric defects. Pediatr Blood Cancer 2009;53:520–523. © 2009 Wiley‐Liss, Inc.
Monotherapy with thalidomide for treatment of spinal cord hemangioblastomas in a patient with von Hippel–Lindau disease
Authors: Sardi Iacopo , Sanzo Massimiliano , Giordano Flavio , Buccoliero Anna Maria , Mussa Federico , Aricò Maurizio , Genitori Lorenzo
Published: May 2009

Von Hippel–Lindau (VHL) disease is a cancer‐prone syndrome characterized by abnormalities in vascular proliferation and the development of both the visceral and CNS tumors. Complications from hemangioblastoma are among the principal causes of death from this syndrome. Antiangiogenic therapy has been used with different modalities in patients suffering from such complications. Here, we describe an adolescent with VHL complicated by progressive, multifocal spinal hemangioblastomas. Treatment with single‐agent thalidomide over the course of 3 years was associated with an unexpected stabilization of the disease. The antiangiogenic effect of thalidomide may be associated with the control of progressive hemangioblastoma. Pediatr Blood Cancer 2009;53:464–467. © 2009 Wiley‐Liss, Inc.
Sample preparation issues for tissue imaging by imaging MS
Authors: Kaletaş Başak Kükrer , van der Wiel Ingrid M. , Stauber Jonathan , Lennard J. Dekker  , Güzel Coşkun , Kros Johan M. , Luider Theo M. , Heeren Ron M. A.
Published: May 2009

Imaging MS is a powerful technique that combines the chemical and spatial analysis of surfaces. It allows spatial localization of multiple different compounds that are recorded in parallel without the need of a label. It is currently one of the rapidly developing techniques in the proteomics toolbox. Different complementary imaging MS methods, i.e. MALDI and secondary ion MS imaging for direct tissue analysis, can be applied on exactly the same tissue sample. This allows the identification of small molecules, peptides and proteins present on the same sample surface. Sample preparation is crucial to obtain high quality, reliable and reproducible complementary molecular images. It is essential to optimize the conditions for each step in the sample preparation protocol, ranging from sample collection and storage to surface modification. In this article, we review and discuss the importance of correct sample treatment in case of MALDI and secondary ion MS imaging experiments and describe the experimental requirements for optimal sample preparation.
Phosphoproteomic analysis of distinct tumor cell lines in response to nocodazole treatment
Authors: Nagano Kohji , Shinkawa Takashi , Mutoh Hironori , Kondoh Osamu , Morimoto Sayuri , Inomata Noriyuki , Ashihara Motooki , Ishii Nobuya , Aoki Yuko , Haramura Masayuki
Published: May 2009

Here, we report for the first time a comparative phosphoproteomic analysis of distinct tumor cell lines in the presence or absence of the microtubule‐interfering agent nocodazole. In total, 1525 phosphorylation sites assigned to 726 phosphoproteins were identified using LC‐MS‐based technology following phosphopeptide enrichment. Analysis of the amino acid composition surrounding the identified in vivo phosphorylation sites revealed that they could be classified into two motif groups: pSer‐Pro and pSer‐Asp/Glu. Phosphoproteomic change resulting from nocodazole treatment varied among cell lines in terms of the numbers of total phosphopeptides identified, motif groups, and functional annotation groups; however, the cell lines were equally sensitive to nocodazole. The identified phosphoproteome subset contained major signaling proteins and proteins known to be involved in mitosis, but did not always exhibit the same changes in the tumor cells from nocodazole treatment. In spite of the complex changes observed in the phosphorylation of many of the proteins, possible common features induced by nocodazole were found, including phosphorylation of nucleophosmin (NPM) S254 and coatomer protein complex, subunit α (COPA) S173, suggesting that the events are not cell‐type specific but events generally occurring in mitosis or induced by a microtubule‐interfering agent. Further, temporal analysis of phosphoproteome change revealed that phosphorylation of NPM S254 and COPA S173 was observed from the early (6 h) and late (24 h) time point after nocodazole treatment, respectively, suggesting that NPM S254 may be involved in the induction of M‐phase arrest by nocodazole, whereas COPA S173 may be caused as a result of M‐phase arrest.
Proteomics of MUC1‐containing lipid rafts from plasma membranes and exosomes of human breast carcinoma cells MCF‐7
Authors: Staubach Simon , Razawi Hanieh , Hanisch Franz‐Georg
Published: May 2009

Apically expressed human MUC1 is known to become endocytosed and either to re‐enter the secretory pathway for recycling to the plasma membrane or to be exported by the cells via the formation of multi‐vesicular bodies and the release of exosomes. By using recombinant fusion‐tagged MUC1 as a bait protein we followed an anti‐myc affinity‐based approach for isolating subpopulations of lipid rafts from the plasma membranes and exosomes of MCF‐7 breast cancer cells. MUC1+ lipid rafts were not only found to contain genuine raft proteins (flotillin‐1, prohibitin, G protein, annexin A2), but also raft‐associated proteins linking these to the cytoskeleton (ezrin/villin‐2, profilin II, HSP27, γ‐actin, β‐actin) or proteins in complexes with raft proteins, including the bait protein (HSP60, HSP70). Major overlaps were revealed for the subproteomes of plasma membranous and exosomal lipid raft preparations, indicating that MUC1 is sorted into subpopulations of rafts for its trafficking via flotillin‐dependent pathways and export via exosomes.
Generally detected proteins in comparative proteomics – A matter of cellular stress response?
Authors: Wang Ping , Bouwman Freek G. , Mariman Edwin C. M.
Published: May 2009

The specificity of proteins identified by proteomics as biomarkers for defined conditions or as components of biological processes and pathways is crucial. We critically reviewed differentially expressed proteins from comparative proteomic studies identified by 2‐DE followed by MS, especially with MALDI technique. Based on 66 of those studies, a list of 44 proteins is presented as generally detected proteins regardless of species, in vivo or in vitro conditions, tissues and organs, and experimental objective. Similarly, a list of 28 generally detected protein families is presented. The enriched functions linked to these generally detected proteins reveal that there are some common biological features beyond the technical limitations. Cellular stress response can be the universal reason as to why these proteins are generally expressed differentially. Using those proteins as biomarkers for cellular processes other than stress response should be done with caution. In future proteomic studies more profound approaches should be applied to look beyond these proteins to find specific biomarkers. Our results are discussed in relation to a recent viewpoint publication by Petrak et al. [Proteomics 2008, 8, 1744–1749].
Distinct contractile and cytoskeletal protein patterns in the Antarctic midge are elicited by desiccation and rehydration
Authors: Li Aiqing , Benoit Joshua B. , Lopez‐Martinez Giancarlo , Elnitsky Michael A. , Lee Richard E. , Denlinger David L.
Published: May 2009

Desiccation presents a major challenge for the Antarctic midge, Belgica antarctica. In this study, we use proteomic profiling to evaluate protein changes in the larvae elicited by dehydration and rehydration. Larvae were desiccated at 75% relative humidity (RH) for 12 h to achieve a body water loss of 35%, approximately half of the water that can be lost before the larvae succumb to dehydration. To evaluate the rehydration response, larvae were first desiccated, then rehydrated for 6 h at 100% RH and then in water for 6 h. Controls were held continuously at 100% RH. Protein analysis was performed using 2‐DE and nanoscale capillary LC/MS/MS. Twenty‐four identified proteins changed in abundance in response to desiccation: 16 were more abundant and 8 were less abundant; 84% of these proteins were contractile or cytoskeletal proteins. Thirteen rehydration‐regulated proteins were identified: 8 were more abundant and 5 were less abundant, and 69% of these proteins were also contractile or cytoskeletal proteins. Additional proteins responsive to desiccation and rehydration were involved in functions including stress responses, energy metabolism, protein synthesis, glucogenesis and membrane transport. We conclude that the major protein responses elicited by both desiccation and rehydration are linked to body contraction and cytoskeleton rearrangements.
Molecular dynamics simulations and functional characterization of the interactions of the PAR2 ectodomain with factor VIIa
Authors: Zhang Qing , Petersen Helle H. , Ostergaard Henrik , Ruf Wolfram , Olson Arthur J.
Published: May 2009

Signaling of the tissue factor‐FVIIa complex regulates angiogenesis, tumor growth, and inflammation. TF‐FVIIa triggers cell signaling events by cleavage of protease activated receptor (PAR2) at the Arg36‐Ser37 scissile bond. The recognition of PAR2 by the FVIIa protease domain is poorly understood. We perform molecular modeling and dynamics simulations to derive the PAR2‐FVIIa interactions. Docking of the PAR2 Arg36‐Ser37 scissile bond to the S1 site and subsequent molecular dynamics leads to interactions of the PAR2 ectodomain with P and P′ sites of the FVIIa catalytic cleft as well as to electrostatic interactions between a stably folded region of PAR2 and a cluster of basic residues remote from the catalytic cleft of FVIIa. To address the functional significance of this interaction for PAR2 cleavage, we employed two antibodies with epitopes previously mapped to this cluster of basic residues. Although these antibodies do not block the catalytic cleft, both antibodies completely abrogated PAR2 activation by TF‐FVIIa. Our simulations indicate a conformation of the PAR2 ectodomain that limits the cleavage site to no more than 33 Å from its membrane proximal residue. Since the active site of FVIIa in the TF‐FVIIa complex is ∼75 Å above the membrane, cleavage of the folded conformation of PAR2 would require tilting of the TF‐FVIIa complex toward the membrane, indicating that additional cellular factors may be required to properly align the scissile bond of PAR2 with TF‐FVIIa. Proteins 2009. © 2009 Wiley‐Liss, Inc.
Molecular determinants of the pKa values of Asp and Glu residues in staphylococcal nuclease
Authors: Castañeda Carlos A. , Fitch Carolyn A. , Majumdar Ananya , Khangulov Victor , Schlessman Jamie L. , García‐Moreno Bertrand E.
Published: May 2009

Prior computational studies of the acid‐unfolding behavior of staphylococcal nuclease (SNase) suggest that the pKa values of its carboxylic groups are difficult to reproduce with electrostatics calculations with continuum methods. To examine the molecular determinants of the pKa values of carboxylic groups in SNase, the pKa values of all 20 Asp and Glu residues were measured with multidimensional and multinuclear NMR spectroscopy in an acid insensitive variant of SNase. The crystal structure of the protein was obtained to describe the microenvironments of the carboxylic groups. Fourteen Asp and Glu residues titrate with relatively normal pKa values that are depressed by less than 1.1 units relative to the normal pKa of Asp and Glu in water. Only six residues have pKa values shifted by more than 1.5 units. Asp‐21 has an unusually high pKa of 6.5, which is probably the result of interactions with other carboxylic groups at the active site. The most perturbed pKa values appear to be governed by hydrogen bonding and not by Coulomb interactions. The pKa values calculated with standard continuum electrostatics methods applied to static structures are more depressed than the measured values because Coulomb effects are exaggerated in the calculations. The problems persist even when the protein is treated with the dielectric constant of water. This can be interpreted to imply that structural relaxation is an important determinant of the pKa values; however, no major pH‐sensitive conformational reorganization of the backbone was detected using NMR spectroscopy. Proteins 2009. © 2009 Wiley‐Liss, Inc.
The α‐particle excited scintillation response of YAG:Ce thin films grown by liquid phase epitaxy
Authors: Prusa Petr , Nikl Martin , Mares Jiri A. , Kucera Miroslav , Nitsch Karel , Beitlerova Alena
Published: May 2009

Y3Al5O12:Ce (YAG:Ce) thin films were grown from PbO‐, BaO‐, and MoO3‐based fluxes using the liquid phase epitaxy (LPE) method. Photoelectron yield, its time dependence within 0.5–10 μs shaping time, and energy resolution of these samples were measured under α‐particle excitation. For comparison a sample of the Czochralski grown bulk YAG:Ce single crystal was measured as well. Photoelectron yield values of samples grown from the BaO‐based flux were found superior to other LPE films and comparable with that of the bulk single crystal. The same is valid also for the time dependence of photoelectron yield. Obtained results are discussed taking into account the influence of the flux and technology used. Additionally, α particle energy deposition in very thin films is modelled and discussed. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Up‐conversion mechanisms in Er3+ doped YbAG crystals
Authors: Kaczkan Marcin , Borowska Maja , Malinowski Michał , Łukasiewicz Tadeusz , Kołodziejak Katarzyna
Published: May 2009

Up‐conversion phenomena leading to the red, green and violet emissions in erbium doped ytterbium‐aluminum garnet (YbAG) are investigated. Absorption and emission spectra and luminescence dynamics from various excited states of YbAG:Er3+ were registered. The low temperature absorption spectra were used to determine Stark levels energies of Er3+ ion in the investigated host. Emissions from the high lying excited states 2G9/2, 4S3/2 and 4F9/2 of Er3+ were characterized under pulsed multi‐photon IR excitation in the region of wavelength corresponding to the strong 2F7/2 → 2F5/2 absorption transition of Yb3+ ions. Using the rate equations formalism the dynamics of the observed emissions were modeled. From the comparison of the measured and calculated decays the energy transfer rates between Yb3+ and Er3+ ions were evaluated. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Reinvestigation of the Fe, Cu and Cr valences in (FeCu)Cr2S4 spinels
Authors: Taubitz Christian , Kuepper Karsten , Raekers Michael , Galakhov Vadim R. , Felea Viorel , Tsurkan Vladimir , Neumann Manfred
Published: May 2009

The valence states of Fe, Cu, and Cr ions in single crystalline Fe1–x Cux Cr2S4 have been studied using X‐ray photoelectron spectroscopy (XPS), X‐ray absorption spectroscopy (XAS) and X‐ray magnetic circular dichroism (XMCD). XPS measurements of compositions x = 0.2, 0.5, 0.6, and 0.9 indicate that the Cu and Cr ions remain mainly in the same valence state over the whole substitution range. XAS, XPS and XMCD investigations of Fe0.5Cu0.5Cr2S4 reveal a sample and preparation dependence of the Cu and Fe spectra. The comparison of the Cu 2p XAS spectrum with a literature measurement shows a change in the amount of Cu2+ explained by the appearance of an additional Cu2+ phase, possibly due to oxidation on the surface. XAS, XPS and XMCD spectra of Fe show a Fe3+ impurity phase present in air‐treated Fe0.5Cu0.5Cr2S4, especially in powdered samples. The lines related to trivalent Fe are found to disappear completely after cleaning the samples in‐situ and only the lines attributed to divalent Fe remain. Since many experimental methods rely on powdered samples and measure in air or in low vacuum, these findings provide an explanation for the differing results concerning the Fe valence obtained by these methods. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Spin‐coupling and hyperfine interaction of the nitrogen donors in 6H‐SiC
Authors: Savchenko Dariya V. , Kalabukhova Ekaterina N. , Kiselev Vitalii S. , Hoentsch Joachim , Pöppl Andreas
Published: May 2009

The X‐, Q‐band field‐sweep electron spin echo (FS ESE) study of n‐type 6H‐SiC wafers shows besides the well known hyperfine (hf) triplet lines of14N on two quasi‐cubic (Nc1, Nc2) and hexagonal (Nh) sites additional triplet lines (Nx) of comparatively low intensity with ag‐tensor of about the average value of the Nc2and Nhspectrum at 4.2 K. The Nxtriplet has half of the hf splitting with respect to the nitrogen residing at cubic sites Nc2. Pulsed electron nuclear double resonance (ENDOR) measurements performed on the NxEPR triplet line demonstrate that there is an efficient spin‐coupling between Nhand Nxnitrogen related centers. The Nxtriplet lines were attributed to distant donor Nc–Nhpairs between nitrogen atoms residing at quasi‐cubic and hexagonal sites having a total electron spinS= 1, which were found before in n‐type 4H‐SiC. Based on Q‐band FS ESE and X‐band pulsed ENDOR measurements the values of the hf interaction for Nc1, Nc2were reassigned with respect to the assignment accepted hitherto.

The super hyperfine (shf) interaction with neighboring atoms of nitrogen on the quasi‐cubic lattice sites was studied by FS ESE and pulsed ENDOR. The new shf lines due to29Si and13C atoms with large shf interaction which were not observed previously were found in nitrogen FS ESE and ENDOR spectra. One of them, with the largest shf splitting (23.12 MHz), were attributed to the29Si atoms along thec‐axis in nearest‐neighbor positions of nitrogen on the quasi‐cubic sites which unambiguously confirms that nitrogen substitute carbon lattice site in 6H‐SiC. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Characteristics of Gastric Cancer with Esophageal Invasion and Aspects of Surgical Treatment
Authors: Wakatsuki Kohei , Takayama Tomoyoshi , Ueno Masato , Matsumoto Sohei , Enomoto Koji , Tanaka Tetsuya , Nakajima Yoshiyuki
Published: May 2009

Background

Gastric cancer with esophageal invasion (GCE) is a disease of poor prognosis, and issues pertaining to surgical treatment still remain unresolved. Particularly problematic areas in GCE cases include the need for lower mediastinal lymph node (MSLN) dissection, the most effective surgical approach, and the optimal extent of the esophageal resection. In this study, we evaluate the characteristics of GCE and investigate aspects of surgical treatment.

Methods

Sixty‐five patients with GCE were surgically treated in our department from 1990 to 2007. Fifty‐two patients with M0 were evaluated for clinicopathological factors, disease recurrence pattern, and prognosis, and 47 patients with R0 resection were evaluated for operative factors.

Results

Patients with MSLN metastasis had significantly poor prognosis. The survival rate significantly differed among patients depending on T‐factor, LN metastasis, MSLN metastasis, and lymphatic vessel invasion, but operative factors were not significant prognostic factors. Multivariate analysis indicated that T‐factor and MSLN metastasis were independent prognostic factors. The peritoneum was the site of the highest recurrence rate (26.9%), followed by the liver (9.6%). Peritoneal recurrence correlated with T‐factor and lymphatic vessel invasion and liver recurrence correlated with MSLN metastasis.

Conclusions

It seems that radical MSLN dissection and extended esophageal resection by thoracotomy have little therapeutic purpose for Siewert Types II or III tumors in GCE if the length of esophageal resection is within 6 cm. Patients with GCE have a poorer prognosis than those with common gastric cancer, and early detection and multimodal treatments for distant metastases are vital for ameliorating clinical outcome in patients with GCE.
Dangerously few liaisons: a review of mate‐finding Allee effects
Authors: Gascoigne Joanna , Berec Ludek , Gregory Stephen , Courchamp Franck
Published: May 2009

In this paper, we review mate‐finding Allee effects from ecological and evolutionary points of view. We define ‘mate‐finding’ as mate searching in mobile animals, and also as the meeting of gametes for sessile animals and plants (pollination). We consider related issues such as mate quality and choice, sperm limitation and physiological stimulation of reproduction by conspecifics, as well as discussing the role of demographic stochasticity in generating mate‐finding Allee effects. We consider the role of component Allee effects due to mate‐finding in generating demographic Allee effects (at the population level). Compelling evidence for demographic Allee effects due to mate‐finding (as well as via other mechanisms) is still limited, due to difficulties in censusing rare populations or a failure to identify underlying mechanisms, but also because of fitness trade‐offs, population spatial structure and metapopulation dynamics, and because the strength of component Allee effects may vary in time and space. Mate‐finding Allee effects act on individual fitness and are thus susceptible to change via natural selection. We believe it is useful to distinguish two routes by which evolution can act to mitigate mate‐finding Allee effects. The first is evolution of characteristics such as calls, pheromones, hermaphroditism, etc. which make mate‐finding more efficient at low density, thus eliminating the Allee effect. Such adaptations are very abundant in the natural world, and may have arisen to avoid Allee effects, although other hypotheses are also possible. The second route is to avoid low density via adaptations such as permanent or periodic aggregation. In this case, the Allee effect is still present, but its effects are avoided. These two strategies may have different consequences in a world where many populations are being artificially reduced to low density: in the first case, population growth rate can be maintained, while in the second case, the mechanism to avoid Allee effects has been destroyed. It is therefore in these latter populations that we predict the greatest evidence for mate‐finding Allee effects and associated demographic consequences. This idea is supported by the existing empirical evidence for demographic Allee effects. Given a strong effect that mate‐finding appears to have on individual fitness, we support the continuing quest to find connections between component mate‐finding Allee effects (individual reproductive fitness) and the demographic consequences. There are many reasons why such studies are difficult, but it is important, particularly given the increasing number of populations and species of conservation concern, that the ecological community understands more about how widespread demographic Allee effects really are, and why.
Extracorporeal membrane oxygenation in a patient with propionic acidaemia: a therapeutic option for cardiac failure
Authors: Mizuguchi K. , Hoshino H. , Nagasawa T. , Kubota M.
Published: May 2009

We report a Japanese girl affected with a neonatal‐onset form of propionic acidaemia (PA). She developed severe metabolic crisis after dehydration at 2 years of age. Bradycardia with complete atrioventricular block responded to haemodiafiltration, but severe cardiac failure was refractory to inotropic treatment. She was diagnosed with acute cardiac dysfunction caused by PA‐induced metabolic crisis. Extracorporeal membrane oxygenation (ECMO), a technique for providing mechanical circulatory support, was required. This is the first case report of a PA patient who recovered from a life‐threatening metabolic crisis with cardiac failure by ECMO. Cardiac failure may be a cause of death, but it is occasionally an under‐recognized complication. Mitochondrial dysfunction in the myocardium due to propionyl‐CoA could contribute to the pathomechanism of cardiac complications of PA. We believe that ECMO should be attempted in PA patients with cardiac failure, in addition to haemodiafiltration and other therapeutic measures, because doing so may lead to the recovery of cardiac dysfunction, as was evident in our patient. In conclusion, prompt investigations and management of cardiac complications should be performed immediately during PA‐induced metabolic crises.
The Effect of Vitamin E Succinate on Ischemia Reperfusion Injury
Authors: Medling Bradley D. , Bueno Reuben , Chambers Christopher , Neumeister Michael W.
Published: May 2009

Ischemia–reperfusion (I/R) injury is, in part, related to the burst of reactive oxygen species (ROS) generated after reperfusion. Vitamin E has been shown to exert its biological effects as an antioxidant, inhibiting the ROS. In this report, the effect of Vitamin E succinate (VES) on ischemia/reperfusion injury and NF-κB expression was studied in a rat skeletal muscle model during reperfusion following a 4-h ischemic period. The study group consisted of muscle flaps infused with 150 mg/kg of VES given intraperitoneally 1 h post-initiation of ischemia. Muscle viability based on nitroblue tetrazolium staining, edema, and Doppler blood flow was measured in a control and a study group. Muscle samples were analyzed by standard gel shift assay. The VES experimental group showed an increase in muscle viability compared to controls (average of 44.675% versus 31.925%, respectively, p=0.0415). Blood flow, measured by Doppler 24 h after reperfusion, was increased in the VES study group compared to controls (10.3 vs. 5.1 ml/g/s p=0.00355). Additionally, the VES group showed a trend of decreasing edema compared with the control; however, not at a level that was statistically significant ( p=0.1267). The VES-treated group showed a decreased expression of NF-κB as compared to controls ( p<0.05). These results show that vitamin E succinate has a protective effect in preventing I/R injury as measured by increased muscle viability and reperfusion blood flow. Vitamin E can exert its efforts as an antioxidant as well as other biological roles, including inhibition of NF-κB.
Crystalline Gaq3Nanostructures: Preparation, Thermal Property and Spectroscopy Characterization
Authors: Yu Ya-Wen , Cho Chun-Pei , Perng Tsong-Pyng
Published: May 2009

Crystalline Gaq31-D nanostructures and nanospheres could be fabricated by thermal evaporation under cold trap. The influences of the key process parameters on formation of the nanostructures were also investigated. It has been demonstrated that the morphology and dimension of the nanostructures were mainly controlled by working temperature and working pressure. One-dimensional nanostructures were fabricated at a lower working temperature, whereas nanospheres were formed at a higher working temperature. Larger nanospheres could be obtained when a higher working pressure was applied. The XRD, FTIR, and NMR analyses evidenced that the nanostructures mainly consisted of δ-phase Gaq3. Their DSC trace revealed two small exothermic peaks in addition to the melting endotherm. The one in lower temperature region was ascribed to a transition from δ to β phase, while another in higher temperature region could be identified as a transition from β to δ phase. All the crystalline nanostructures show similar PL spectra due to absence of quantum confinement effect. They also exhibited a spectral blue shift because of a looser interligand spacing and reduced orbital overlap in their δ-phase molecular structures.
Tin Oxide Nanowires: The Influence of Trap States on Ultrafast Carrier Relaxation
Authors: Othonos Andreas , Zervos Matthew , Tsokkou Demetra
Published: May 2009

We have studied the optical properties and carrier dynamics in SnO2nanowires (NWs) with an average radius of 50 nm that were grown via the vapor–liquid solid method. Transient differential absorption measurements have been employed to investigate the ultrafast relaxation dynamics of photogenerated carriers in the SnO2NWs. Steady state transmission measurements revealed that the band gap of these NWs is 3.77 eV and contains two broad absorption bands. The first is located below the band edge (shallow traps) and the second near the center of the band gap (deep traps). Both of these absorption bands seem to play a crucial role in the relaxation of the photogenerated carriers. Time resolved measurements suggest that the photogenerated carriers take a few picoseconds to move into the shallow trap states whereas they take ~70 ps to move from the shallow to the deep trap states. Furthermore the recombination process of electrons in these trap states with holes in the valence band takes ~2 ns. Auger recombination appears to be important at the highest fluence used in this study (500 μJ/cm2); however, it has negligible effect for fluences below 50 μJ/cm2. The Auger coefficient for the SnO2NWs was estimated to be 7.5 ± 2.5 × 10−31 cm6/s.
Field Emission Properties and Fabrication of CdS Nanotube Arrays
Authors: Qian Xuemin , Liu Huibiao , Guo Yanbing , Zhu Shiqun , Song Yinglin , Li Yuliang
Published: May 2009

A large area arrays (ca. 40 cm2) of CdS nanotube on silicon wafer are successfully fabricated by the method of layer-by-layer deposition cycle. The wall thicknesses of CdS nanotubes are tuned by controlling the times of layer-by-layer deposition cycle. The field emission (FE) properties of CdS nanotube arrays are investigated for the first time. The arrays of CdS nanotube with thin wall exhibit better FE properties, a lower turn-on field, and a higher field enhancement factor than that of the arrays of CdS nanotube with thick wall, for which the ratio of length to the wall thickness of the CdS nanotubes have played an important role. With increasing the wall thickness of CdS nanotube, the enhancement factorβ decreases and the values of turn-on field and threshold field increase.
Facile Synthesis of Ternary Boron Carbonitride Nanotubes
Authors: Luo Lijie , Mo Libin , Tong Zhangfa , Chen Yongjun
Published: May 2009

In this study, a novel and facile approach for the synthesis of ternary boron carbonitride (B–C–N) nanotubes was reported. Growth occurred by heating simple starting materials of boron powder, zinc oxide powder, and ethanol absolute at 1150 °C under a mixture gas flow of nitrogen and hydrogen. As substrate, commercial stainless steel foil with a typical thickness of 0.05 mm played an additional role of catalyst during the growth of nanotubes. The nanotubes were characterized by SEM, TEM, EDX, and EELS. The results indicate that the synthesized B–C–N nanotubes exhibit a bamboo-like morphology and B, C, and N elements are homogeneously distributed in the nanotubes. A catalyzed vapor–liquid–solid (VLS) mechanism was proposed for the growth of the nanotubes.
Synthesis and Properties of Lipoamino Acid–Fatty Acid Mixtures: Influence of the Amphiphilic Structure
Authors: Rondel Caroline , Alric Isabelle , Mouloungui Zéphirin , Blanco Jean‐François , Silvestre Françoise
Published: May 2009

The acylation of amino acids by acid chlorides with from 8 to 12 carbon atoms in alkaline aqueous medium following Schotten–Baumann reaction results in sodium salts of a Nα‐acylamino acid and fatty acid mixture. The latter are present in a proportion from 40 to 60%. These compositions represent mixtures of amphiphilic anionic surfactants. Together they contribute to the properties of the formulation. Measurements of the surface‐active properties of these formulations, such as critical micelle concentration (CMC), surface tension at the CMC (ST), foaming capacity (FC) and foaming stability (FS), show that surfactant mixtures with the longest chain have the most desirable properties. They are comparable to commercial petroleum‐based surfactants. Thus, the CMC, ST and CM values of the formulation obtained starting from leucine and dodecanoyl chloride (310 mg/l, 30.1 mN/m and 200%, respectively) are similar to, and even better than, sodium dodecylsulfate (290 mg/l, 39.1 mN/m and 230%, respectively).