bluuebunny/crossref_metadata_2025 huggingface dataset:
The faster the better?—A systematic review on distress in the diagnostic phase of suspected cancer, and the influence of rapid diagnostic pathways
Authors: Brocken Pepijn , Prins Judith B. , Dekhuijzen P. N. Richard , van der Heijden Henricus F. M.
Published: February 2011

Objective: To perform a systematic review of articles published in the last 25 years on prevalence and course of distress and quality of life surrounding the diagnostic process of suspected cancer, and the influence of rapid diagnostic programs.

Methods: Twenty‐three articles were identified via Pubmed, PsycINFO, and reference lists of articles. Except for three randomized clinical trials and one case control study all studies were uncontrolled cohort studies.

Results: Most studies involved patients with suspected breast cancer and therefore had a sex selection bias. Four studies on the effect of rapid outpatient diagnostic programs were found. Studies showed very high prevalence of anxiety, decreasing in case of a benign diagnosis but increasing or sustaining in patients waiting for results or after cancer diagnosis though not significantly more in rapid programs. Quality of life was low and showed varying patterns.

Conclusions: Distress in the diagnostic phase of cancer is a major problem and the rapid decrease of anxiety in patients eventually not diagnosed with cancer suggests a benefit of rapid diagnostic programs. The available evidence however is limited and shows some inconsistencies. Studies differ in subjects, objective and are limited by quality and quantity. Conflicting results prohibit a conclusion on patients ultimately diagnosed with cancer. Copyright © 2011 John Wiley & Sons, Ltd.
Development of guidelines for distress management in Korean cancer patients
Authors: Yu Eun‐Seung , Shim Eun Jung , Kim Ha Kyoung , Hahm Bong‐Jin , Park Jong‐Hyock , Kim Jong‐Heun
Published: February 2011

Objectives: Psychological distress is common in cancer patients, and the need to develop a system for assessing and managing distress is widely recognized. This project developed recommendations that are feasible for Korean cancer patients and the Korean healthcare system.

Methods: Based on the findings from a series of studies in the context of this project, we developed guidelines following the steps and parameters recommended by the Scottish Intercollegiate Guidelines Network (SIGN). The Development Group consisted of individuals from several professions, including psychiatrists, psychologists, nurses, social workers, a health policy expert, and a methodologist. Opinions from various healthcare providers, patients, and related societies were also reflected in the guidelines.

Results: The main recommendations for distress management in cancer patients were the following: (1) a concept of distress in Korean cancer patients, screening tools, management algorithms, and triage approaches was developed and (2) four symptom‐specific guidelines with management algorithms were proposed for depression, anxiety, insomnia, and delirium.

Conclusion: This is the first effort to develop recommendations for distress management in psycho‐oncology in Korea. These guidelines offer standards for psychosocial care for cancer patients in Korea. We have made a significant step toward integrated cancer care that incorporates the psychosocial care of patients as an essential component of patient care in a Korean oncology context. This version will be updated constantly to keep up with emerging evidence from empirical research and clinical experience. Copyright © 2011 John Wiley & Sons, Ltd.
Implications of a needs assessment intervention for people with progressive cancer: Impact on clinical assessment, response and service utilisation
Authors: Waller Amy , Girgis Afaf , Johnson Claire , Lecathelinais Christophe , Sibbritt David , Seldon Michael , Bonaventura Tony , Currow David ,   on behalf of the Palliative Care Research Program team
Published: February 2011

Objective: To assess the impact of the systematic use of the Palliative Care Needs Assessment Guidelines and Needs Assessment Tool: Progressive Disease‐Cancer (NAT: PD‐C) on clinical assessment, response and service utilisation.

Study setting: Three major oncology treatment centres in NSW, Australia.

Study design: Between March 2007 and December 2009, 219 people with advanced cancer were recruited to complete bi‐monthly telephone interviews. The intervention, introduced after at least two baseline interviews, involved training health professionals to complete the NAT: PD‐C with patients approximately monthly.

Data collection: Rates of service use and referrals were compared pre‐ and post‐introduction of the NAT: PD‐C. Rates of completion of the tool; its impact on consultation length; and the types of needs and follow‐up care to address these were also assessed.

Principal findings: The NAT: PD‐C had a high rate of completion; identified needs consistent with those self‐reported by patients in interviews; and did not alter consultation length. No changes in the number of health professionals seen by patients were found pre‐ and post‐intervention.

Conclusion: The NAT: PD‐C is an efficient and acceptable strategy for supporting needs‐based cancer care that can potentially be incorporated into standard routine care without increasing the burden on care providers. Copyright © 2011 John Wiley & Sons, Ltd.
Role of Room Temperature Sputtered High Conductive and High Transparent Indium Zinc Oxide Film Contacts on the Performance of Orange, Green, and Blue Organic Light Emitting Diodes
Authors: Gonçalves Gonçalo , Grasso Valentina , Barquinha Pedro , Pereira Luís , Elamurugu Elangovan , Brignone Mauro , Martins Rodrigo , Lambertini Vito , Fortunato Elvira
Published: February 2011

The core of this paper concerns the use of an amorphous transparent conductive oxide (a‐TCO), whose performance is on par with the classical indium tin oxide (ITO) films as a transparent contact in organic light emitting diodes (OLEDs). The main advantage of indium zinc oxide (IZO) films relies on their amorphous structure and high mobility that turns them likely to be used with high conductivity and high transmittance even at the infrared region. The mobility of IZO films (47.8 cm2 · V−1 · s−1) surpasses the one exhibited by ITO films (26.4 cm2 · V−1 · s−1), which along with its smoother surface and better current distribution plays an important role on OLEDs performance. Besides their similar turn‐on voltage, the devices using IZO anodes exhibit higher power efficiency than the ITO ones, which is 66, 18, and 62% for orange, green, and blue OLEDs, respectively. These results suggest that IZO can potentially be applied as an anode in full color displays based on OLEDs.

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The Properties of Multilayer CrCN/CrN Coatings Dependent on Their Architecture
Authors: Warcholinski Bogdan , Gilewicz Adam
Published: February 2011

CrN based multilayer coatings are possible replacements for chromium nitride monolayer coating because of their good mechanical and chemical properties. This paper reports an investigation of CrCN/CrN coatings deposited on HS6‐5‐2 steel substrate using cathodic arc evaporation. The investigated coatings of the total thickness of ca. 2.5 µm were composed of six bilayers, each of them with alternating CrCN and CrN layers. The thickness of the bilayer was ca. 400 nm and the ratio of layer thickness partition (CrCN/CrN) was 1:5, 1:2 and 1:1. The chemical composition was determined with the EDS method. The microstructure of thin films was examined with the SEM. A micro Vickers hardness tester and pin‐on‐disc wear tests were used to determine the hardness and tribological properties of the coatings: the coefficient of the friction and wear rate. In order to assess the adhesion of the coatings to the substrate, the scratch test and Rockwell test were applied. All the coatings investigated are characterized by a good adhesion which decreases with the rise of the CrCN layer thickness in the bilayer. When the CrCN layer thickness in bilayer rises, the hardness and compressive stress increase, but the wear rate decreases.

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Permafrost thermal regime from two 30‐m deep boreholes in southern victoria land, antarctica
Authors: Guglielmin Mauro , Balks Megan R. , Adlam Leah S. , Baio Fabio
Published: February 2011

Two 30‐m deep permafrost temperature‐monitoring boreholes were installed in bedrock, one at Marble Point and one in the Wright Valley, in the Ross Sea region of Antarctica. A soil climate‐monitoring station in till is located near each borehole. The ground surface temperature (GST) was highly correlated with the air temperature at both sites in 2008. Thermal offsets were small (< 1 °C) in the till and negligible in the boreholes. The active layer was thicker in the boreholes than in the till, presumably because of the higher thermal diffusivity of the rock. The measured depth of zero annual temperature amplitude was around 27 m at Wright Valley and 25 m at Marble Point. Permafrost thickness was estimated at about 680 m at Wright Valley and 490 m at Marble Point. The GST history, reconstructed using an inversion procedure, suggests a slight cooling from 1998 to 2003 followed by a slight warming to 2008. Longer temperature records or deeper boreholes would be required to establish if long‐term climate change has occurred. Copyright © 2011 John Wiley & Sons, Ltd.
Isotope characterisation of ground ice in northern Canada
Authors: Michel F. A.
Published: February 2011

This paper reviews isotopic research on the characterisation and identification of various types of ground ice throughout the Canadian Arctic, including buried glacier ice, massive segregated ice, segregated ice lenses and offshore ice‐rich permafrost, as well as ice related to other cold‐region phenomena such as ice wedges, icings (aufeis), frost blisters and pingos. The formational age of ground ice bodies ranges from recent (seasonal ice in the active layer) to tens of thousands of years, when the region experienced widespread continental‐scale glaciation. Modern ice lenses generally have 18O/16O ratios of ‐18 to ‐22‰, while modern ice wedges usually range from ‐22 to ‐25‰. δ18O values as high as ‐14‰ are representative of the Hypsithermal period (4000 to 8000 years BP), while glacial‐age ice has been measured with 18O/16O ratios as low as ‐36‰. Buried glacier ice often preserves climatic variations from the time of snow deposition. Other massive ground ice bodies contain isotopic signatures (18O and 2H) that indicate variable fractionation of the isotopes during freezing of the source water at stationary freezing fronts in either open or closed systems. Placing the ice bodies into a time frame can be accomplished either through age dating of the enclosing sediments and encased organics, or by direct dating of the ice utilising tritium (3H) for relatively young ice and radiocarbon (14C) analysis of contained gas bubbles for older ice. Copyright © 2011 John Wiley & Sons, Ltd.
Probing the self‐association, intermolecular contacts, and folding propensity of amelogenin
Authors: Ndao Moise , Dutta Kaushik , Bromley Keith M. , Lakshminarayanan Rajamani , Sun Zhi , Rewari Gita , Moradian‐Oldak Janet , Evans John Spencer
Published: February 2011

Amelogenins are an intrinsically disordered protein family that plays a major role in the development of tooth enamel, one of the most highly mineralized materials in nature. Monomeric porcine amelogenin possesses random coil and residual secondary structures, but it is not known which sequence regions would be conformationally attractive to potential enamel matrix targets such as other amelogenins (self‐assembly), other matrix proteins, cell surfaces, or biominerals. To address this further, we investigated recombinant porcine amelogenin (rP172) using “solvent engineering” techniques to simultaneously promote native‐like structure and induce amelogenin oligomerization in a manner that allows identification of intermolecular contacts between amelogenin molecules. We discovered that in the presence of 2,2,2‐trifluoroethanol (TFE) significant folding transitions and stabilization occurred primarily within the N‐ and C‐termini, while the polyproline Type II central domain was largely resistant to conformational transitions. Seven Pro residues (P2, P127, P130, P139, P154, P157, P162) exhibited conformational response to TFE, and this indicates these Pro residues act as folding enhancers in rP172. The remaining Pro residues resisted TFE perturbations and thus act as conformational stabilizers. We also noted that TFE induced rP172 self‐association via the formation of intermolecular contacts involving P4–H6, V19–P33, and E40–T58 regions of the N‐terminus. Collectively, these results confirm that the N‐ and C‐termini of amelogenin are conformationally responsive and represent potential interactive sites for amelogenin–target interactions during enamel matrix mineralization. Conversely, the Pro, Gln central domain is resistant to folding and this may have important functional significance for amelogenin.
Docosahexaenoic acid selectively induces human prostate cancer cell sensitivity to oxidative stress through modulation of NF‐κB
Authors: Cavazos David A. , Price Ramona S. , Apte Shruti S. , deGraffenried Linda A.
Published: February 2011

BACKGROUND

Oxidative burden is strongly implicated in the pathogenesis of age‐related diseases, including prostate cancer tumor formation. As omega‐3 fatty acids possess known antioxidant properties, we investigated the effects of docosahexaenoic acid (DHA‐22:6n‐3), one component of fish oil, in modulating the effects of oxidative DNA damage in LNCaP and PacMetUT1 human prostate adenocarcinoma cells and in a normal human prostate cell line, PrEC.

METHODS

Cell survival was determined by an inhibition of colony formation assay. DNA double‐strand breaks, NF‐κB subcellular localization and relative survivin expression levels were determined by immunofluorescence and survivin expression levels confirmed by immunoblot assay. Measurement of NF‐κB transcriptional activity was investigated by dual luciferase assay.

RESULTS

LNCaP and PacMetUT1 cells pretreated with DHA and pulsed with 32 µM H2O2 exhibit decreased survival compared to PrEC. γ‐H2AX foci, indicating DNA double‐strand breaks, were associated with translocation of NF‐κB into the nucleus, whereas exposure to DHA prior to H2O2 treatment prevented NF‐κB translocation. Further, DHA attenuated H2O2‐induced NF‐κB transcriptional activity and diminished expression of the downstream target, survivin.

CONCLUSIONS

NF‐κB is heavily implicated in promoting prosurvival signaling and may be critical for resistance to the chronic oxidative stress observed in the pathogenesis of prostate cancer. Our studies indicate that exposure of cells to physiologically achievable levels of DHA prior to treatment with H2O2 results in decreased cancer cell survival which is associated with nuclear exclusion of NF‐κB. We therefore propose that DHA selectively sensitizes prostate cancer cells to growth arrest through attenuation of the NF‐κB survival pathway. Prostate 71:1420–1428, 2011. © 2011 Wiley‐Liss, Inc.
hZIP1 zinc transporter down‐regulation in prostate cancer involves the overexpression of ras responsive element binding protein‐1 (RREB‐1)
Authors: Zou Jing , Milon Beatrice C. , Desouki Mohamed M. , Costello Leslie C. , Franklin Renty B.
Published: February 2011

BACKGROUND

A marked decrease in the level of zinc is a consistent characteristic of prostate cancer; which results from down‐regulation of ZIP1 zinc transporter. The aim of this study was to determine if RREB‐1 transcription is involved in the down‐regulation of ZIP1 gene expression; and to determine the expression of RREB‐1 in benign and cancerous prostate in situ.

METHODS

Overexpression and siRNA knock down of RREB‐1 were used to determine the effect of RREB‐1 on hZIP1 abundance in PC‐3 cells. Immunohistochemistry with tissue microarrays (TMAs) and tissue sections was used to determine the levels of RREB‐1 expression in prostate in situ.

RESULTS

Overexpression of RREB‐1 resulted in a decrease in the abundance of hZIP1 in the plasma membrane of PC‐3 cells; whereas siRNA knock down significantly increased hZIP1 expression. Prostate TMAs and tissue sections showed an inverse relationship between RREB‐1 and hZIP1 staining.

CONCLUSIONS

RREB‐1 overexpression results in down‐regulation of hZIP1 and contributes to the loss of hZIP1 expression and zinc in prostate cancer. This is an early event in prostate carcinogenesis. Prostate 71:1518–1524, 2011. © 2011 Wiley‐Liss, Inc.
Genetic variation in RNASEL and risk for prostate cancer in a population‐based case–control study
Authors: Fesinmeyer Megan D. , Kwon Erika M. , Fu Rong , Ostrander Elaine A. , Stanford Janet L.
Published: February 2011

BACKGROUND

Linkage studies have implicated chromosome 1q24 as a putative locus for hereditary prostate cancer. The RNASEL gene maps to 1q24 and has been associated with prostate cancer risk in multiple family‐based linkage studies. The RNASEL gene product combats viral infection by degrading viral RNA and inducing apoptosis of infected cells. Few studies have evaluated the role of RNASEL variants in unselected or sporadic prostate cancer, or have considered the potential interaction between RNASEL variants and patient characteristics associated with past infection.

METHODS

Ten SNPs in the RNASEL gene were genotyped in 1,308 prostate cancer cases and 1,267 age‐matched controls from prior population‐based, case–control studies. The association between each SNP and haplotype with prostate cancer risk was calculated using logistic regression. Associations stratified by Gleason score were evaluated using polytomous regression. The likelihood ratio test was used to investigate effect modification.

RESULTS

Two RNASEL SNPs were associated with overall increases in prostate cancer risk (OR = 1.13 for each variant allele of rs12723593; OR = 1.88 for any variant allele of rs56250729). Risk estimates did not vary substantially by Gleason score, but there was effect modification for the variant allele of rs635261 by history of prostatitis (P = 0.02).

CONCLUSIONS

This study identified three RNASEL variants that are associated with risk for prostate cancer. Further research is required to confirm these results and to better understand the potential role RNASEL variants may play in the etiology of sporadic prostate cancer. Prostate 71:1538–1547, 2011. © 2011 Wiley‐Liss, Inc.
SWAP70, actin‐binding protein, function as an oncogene targeting tumor‐suppressive miR‐145 in prostate cancer
Authors: Chiyomaru Takeshi , Tatarano Shuichi , Kawakami Kazumori , Enokida Hideki , Yoshino Hirofumi , Nohata Nijiro , Fuse Miki , Seki Naohiko , Nakagawa Masayuki
Published: February 2011

BACKGROUND

MiR‐145 is down‐regulated in various human cancers. We previously demonstrated that some actin‐binding proteins were targeted by several microRNAs (miRNAs), including miR‐145, in bladder and prostate cancer (CaP). The aim of this study is to determine a novel oncogenic gene targeted by miR‐145 by focusing on actin‐binding proteins in CaP.

METHODS

We focused on the SWAP switching B‐cell complex 70 kDa subunit (SWAP70), which is an F‐actin binding protein involved in activating B‐cell transformation. A luciferase reporter assay was used to identify the actual binding sites between miR‐145 and SWAP70 mRNA. Cell viability was evaluated by cell proliferation, wound healing, and matrigel invasion assays in si‐SWAP70 transfectants. A total of 75 clinical prostate specimens were subjected to immunohistochemistry of SWAP70.

RESULTS

Molecular target searches of this miRNA and the luciferase reporter assay showed that SWAP70 was directly regulated by miR‐145. Silencing of SWAP70 studies demonstrated significant inhibitions of cell migration and invasion in CaP cell lines. The SWAP70 positive‐staining was significantly higher in percentage in the CaP than in benign prostate hyperplasia tissue.

CONCLUSIONS

Down‐regulation of miR‐145 was a frequent event in CaP, and it may have a tumor suppressive function. SWAP70 may be a target of miR‐145, and it might have a potential oncogenic function. The novel molecular networks though which miR‐145 acts, may provide new insights into the underlying molecular mechanisms of CaP. Prostate 71:1559–1567, 2011. © 2011 Wiley‐Liss, Inc.
Gene expression pathways of high grade localized prostate cancer
Authors: Ross Ashley E. , Marchionni Luigi , Vuica‐Ross Milena , Cheadle Chris , Fan Jinshui , Berman David M. , Schaeffer Edward M.
Published: February 2011

BACKGROUND

Despite advances in screening and local therapy, prostate cancer remains the second most common cause of cancer related death among American men, with those having high grade disease being at highest risk for prostate cancer mortality. Here we identify the genes and cellular pathways that distinguish high grade from low grade pathologically localized prostate cancer.

METHODS

Cancer cells from low grade (Gleason 3 + 3 = 6) or high grade (4 + 4 = 8) tumors of men with localized disease were isolated by laser capture micro‐dissection. Expression profiling was conducted across 18,344 unique annotated genes and data were analyzed using packages from the R/Bioconductor project to determine differential gene expression and perform gene set enrichment analysis. Publically available expression data was retrieved and analyzed individually in the same manner and in cross platform meta‐analyses.

RESULTS

Six hundred seventy genes were differentially expressed between Gleason sum 6 and 8 tumors with a false discovery rate of <5% (P < 0.0014) including genes previously shown to mediate prostate cancer survival, proliferation, and metastasis. Functional themes associated with Gleason grade included developmental processes, signal transduction, chemokine and embryonic stem cell pathways with specific enrichment of the androgen receptor, EGFR, TNF‐alpha, and Notch signaling cascades.

CONCLUSIONS

In addition to androgen receptor signaling, growth factor, and cytokine mediated pathways are active in clinically localized high grade prostate cancer. The availability of therapeutics that selectively target these pathways encourages the development of clinical trials for their selective use in the neoadjuvant or adjuvant setting in men at high risk for disease progression. Prostate 71:1568–1578, 2011. © 2011 Wiley‐Liss, Inc.
Efficacy of layer treatment with methoprene for control of Rhyzopertha dominica (Coleoptera: Bostrychidae) on wheat, rice and maize
Authors: Athanassiou Christos G , Arthur Frank H , Throne James E
Published: February 2011

BACKGROUND: Insect growth regulators are promising alternatives to traditional pesticides in stored grain. The efficacy of the juvenile hormone analogue methoprene was evaluated as a layer treatment in a laboratory experiment for control of Rhyzopertha dominica (F.) (Coleoptera: Bostrychidae) in wheat, rice and maize.

RESULTS: Adults of R. dominica were placed in vials containing 33, 26 and 29 g (to a depth of 6.5 cm) of wheat, rice and maize, respectively, that was entirely or partially treated with 1, 5 or 10 mg kg−1 methoprene. In wheat and rice, the layer treatments were not as effective as the whole‐grain treatment, but there was decreased progeny production as the application rate increased. However, on maize the partial treatments were as effective as the whole‐grain treatment at 5 and 10 mg kg−1.

CONCLUSIONS: The results suggest that partial layer treatments with methoprene can be used to control R. dominica on maize but may not be effective for control of this species on wheat and rice. Copyright © 2011 Society of Chemical Industry
Impact of Cry3Bb1‐expressing Bt maize on adults of the western corn rootworm, Diabrotica virgifera virgifera (Coleoptera: Chrysomelidae)
Authors: Meissle Michael , Hellmich Richard L , Romeis Jörg
Published: February 2011

BACKGROUND: Genetically engineered maize producing insecticidal Cry3Bb1 protein from Bacillus thuringiensis (Bt) is protected from root damage by corn rootworm larvae. An examination was made to establish whether western corn rootworm (Diabrotica virgifera virgifera) adults are affected by Cry3Bb1‐expressing maize (MON88017) when feeding on above‐ground tissue.

RESULTS: In laboratory bioassays, adult D. v. virgifera were fed for 7 weeks with silk, leaves or pollen from Bt maize or the corresponding near‐isoline. Male, but not female, survival was reduced in the Bt‐leaf treatment compared with the control. Female weight was lower when fed Bt maize, and egg production was reduced in the Bt‐silk treatment. ELISA measurements demonstrated that beetles feeding on silk were exposed to higher Cry3Bb1 concentrations than beetles collected from Bt‐maize fields in the United States. In contrast to silk and pollen, feeding on leaves resulted in high mortality and low fecundity. Females feeding on pollen produced more eggs than on silk. C:N ratios indicated that silk does not provide enough nitrogen for optimal egg production.

CONCLUSIONS: Direct effects of Cry3Bb1 on adult beetles could explain the observed effects, but varietal differences between Bt and control maize are also possible. The impact of Bt maize on adult populations, however, is likely to be limited. Copyright © 2011 Society of Chemical Industry
Gastrin and cholecystokinin peptide‐based radiopharmaceuticals: an in vivo and in vitro comparison
Authors: Tornesello Anna Lucia , Aurilio Michela , Accardo Antonella , Tarallo Laura , Barbieri Antonio , Arra Claudio , Tesauro Diego , Morelli Giancarlo , Aloj Luigi
Published: February 2011

The development of suitable radioligands for targeting CCK‐2 receptor expressing tumors, such as medullary thyroid carcinoma, is of great clinical interest. In the search for the best CCK‐2R binding peptides, we have synthesized, evaluated and compared the CCK8 peptide (Asp‐Tyr‐Met‐Gly‐Trp‐Met‐Asp‐PheNH2) and two gastrin analogs commonly referred to as MG0 (DGlu‐Glu(5)‐Ala‐Tyr‐Gly‐Trp‐Met‐Asp‐PheNH2) and MG11 (DGlu(1)‐Ala‐Tyr‐Gly‐Trp‐Met‐Asp‐PheNH2). The N‐terminal portion of the three peptide sequences was derivatized by introducing the DTPAGlu or DOTA chelators to allow radiolobeling with 111In(III) and 68Ga(III), respectively. Saturation binding and cellular internalization experiments were performed on A431 cells overexpressing CCK2R (A431‐CCK2R). All compounds showed Kd values in the nM range and were internalized with similar rates in CCK2 receptor overexpressing cells. Biodistribution experiments showed higher specific uptake of both MG0‐based compounds compared to conjugates containing the CCK8 and MG11 peptide sequences. The higher retention levels of MG0‐based peptides were associated with markedly elevated and undesired kidney uptake compared to the other compounds. Current indications suggest that the 5 Glu N‐terminal residues while improving peptide stability and receptor‐mediated tumor uptake cause unacceptably high kidney retention. Although displaying lower absolute tumor uptake values, the DOTA‐coupled CCK8 peptide provided the best tumor to kidney uptake ratio and appears more suitable as lead compound for improvement of radiopharmaceutical properties. Copyright © 2011 European Peptide Society and John Wiley & Sons, Ltd.
Derivatization of peptides as quaternary ammonium salts for sensitive detection by ESI‐MS
Authors: Cydzik Marzena , Rudowska Magdalena , Stefanowicz Piotr , Szewczuk Zbigniew
Published: February 2011

A series of model peptides in the form of quaternary ammonium salts at the N‐terminus was efficiently prepared by the solid‐phase synthesis. Tandem mass spectrometric analysis of the peptide quaternary ammonium derivatives was shown to provide sequence confirmation and enhanced detection. We designed the 2‐(1,4‐diazabicyclo[2.2.2] octylammonium)acetyl quaternary ammonium group which does not suffer from neutral losses during MS/MS experiments. The presented quaternization of 1,4‐diazabicyclo[2.2.2]octane (DABCO) by iodoacetylated peptides is relatively easy and compatible with standard solid‐phase peptide synthesis. This methodology offers a novel sensitive approach to analyze peptides and other compounds. Copyright © 2011 European Peptide Society and John Wiley & Sons, Ltd.
Probing structural transitions in both structured and disordered proteins using site‐directed spin‐labeling EPR spectroscopy
Authors: Longhi Sonia , Belle Valérie , Fournel André , Guigliarelli Bruno , Carrière Frédéric
Published: February 2011

EPR spectroscopy is a technique that specifically detects unpaired electrons. EPR‐sensitive reporter groups (spin labels or spin probes) can be introduced into biological systems via site‐directed spin‐labeling (SDSL). The basic strategy of SDSL involves the introduction of a paramagnetic group at a selected protein site. This is usually accomplished by cysteine‐substitution mutagenesis, followed by covalent modification of the unique sulfydryl group with a selective reagent bearing a nitroxide radical. In this review we briefly describe the theoretical principles of this well‐established approach and illustrate how we successfully applied it to investigate structural transitions in both human pancreatic lipase (HPL), a protein with a well‐defined α/β hydrolase fold, and the intrinsically disorderedC‐terminal domain of the measles virus nucleoprotein (NTAIL) upon addition of ligands and/or protein partners. In both cases, SDSL EPR spectroscopy allowed us to document protein conformational changes at the residue level. The studies herein summarized show that this approach is not only particularly well‐suited to study IDPs that inherently escape atomistic description by X‐ray crystallography but also provides dynamic information on structural transitions occurring within well‐characterized structured proteins for which X‐ray crystallography can only provide snapshots of the initial and final stages. Copyright © 2011 European Peptide Society and John Wiley & Sons, Ltd.
Chemical synthesis and evaluation of a backbone‐cyclized minimized 2‐helix Z‐domain
Authors: Järver Peter , Mikaelsson Cecilia , Karlström Amelie Eriksson
Published: February 2011

The Z‐molecule is a small, engineered IgG‐binding affinity protein derived from the immunoglobulin‐binding domain B of Staphylococcus aureus protein A. The Z‐domain consists of 58 amino acids forming a well‐defined antiparallel three‐helix structure. Two of the three helices are involved in ligand binding, whereas the third helix provides structural support to the three‐helix bundle. The small size and the stable three‐helix structure are two attractive properties comprised in the Z‐domain, but a further reduction in size of the protein is valuable for several reasons. Reduction in size facilitates synthetic production of any protein‐based molecule, which is beneficial from an economical viewpoint. In addition, a smaller protein is easier to manipulate through chemical modifications. By omitting the third stabilizing helix from the Z‐domain and joining the N‐ and C‐termini by a native peptide bond, the affinity protein obtains the advantageous properties of a smaller scaffold and in addition becomes resistant to exoproteases. We here demonstrate the synthesis and evaluation of a novel cyclic two‐helix Z‐domain. The molecule has retained affinity for its target protein, is resistant to heat treatment, and lacks both N‐ and C‐termini. Copyright © 2011 European Peptide Society and John Wiley & Sons, Ltd.
Low‐generation asymmetric dendrimers exhibit minimal toxicity and effectively complex DNA
Authors: Shah Neha , Steptoe Raymond J. , Parekh Harendra S.
Published: February 2011

Conventional dendrimers are spherical symmetrically branched polymers ending with active surface functional groups. Polyamidoamine (PAMAM) dendrimers have been widely studied as gene delivery vectors and have proven effective at delivering DNA to cells in vitro. However, higher‐generation (G4‐G8) PAMAM dendrimers exhibit toxicity due to their high cationic charge density and this has limited their application in vitro and in vivo. Another limitation arises when attempts are made to functionalize spherical dendrimers as targeting moieties cannot be site‐specifically attached. Therefore, we propose that lower‐generation asymmetric dendrimers, which are likely devoid of toxicity and to which site‐specific attachment of targeting ligands can be achieved, would be a viable alternative to currently available dendrimers. We synthesized and characterized a series of peptide‐based asymmetric dendrimers and compared their toxicity profile and ability to condense DNA to spherical PAMAM G1 dendrimers. We show that asymmetric dendrimers are minimally toxic and condense DNA into stable toroids which have been reported necessary for efficient cell transfection. This paves the way for these systems to be conjugated with targeting ligands for gene delivery in vitro and in vivo. Copyright © 2011 European Peptide Society and John Wiley & Sons, Ltd.
Triplet–triplet energy transfer studies on conformational dynamics in peptides and a protein
Authors: Reiner Andreas
Published: February 2011

Peptides and proteins are highly dynamic systems, which can adopt more or less stable conformations. The dynamics of these molecules, particularly those on the nanosecond to tens of microsecond time scale, are difficult to assess with conventional techniques. This review summarizes experiments using TTET, a technique that reports on van der Waals contact formation between a triplet donor and acceptor group, and which is sensitive in this time range. TTET allows to directly measure the chain dynamics of unstructured model peptides, i.e. large‐amplitude fluctuations on the nanosecond time scale. Furthermore, contact formation can be used as irreversible probing reaction to study the kinetics of conformational equilibria. This approach enabled us to measure local α‐helix folding and unfolding in helical peptides, which gave new insight into the equilibrium dynamics of this fundamental secondary structure element. TTET has also been applied to study the dynamics both in the native and unfolded state of a protein, the villin headpiece subdomain. The contact formation kinetics between different positions revealed an unlocking and local unfolding reaction in the native state of this model protein, and gave information about the chain dynamics in the unfolded state ensemble. Copyright © 2011 European Peptide Society and John Wiley & Sons, Ltd.
Amino acid sequence preferences to control cell‐specific organization of endothelial cells, smooth muscle cells, and fibroblasts
Authors: Kanie Kei , Kato Ryuji , Zhao Yingzi , Narita Yuji , Okochi Mina , Honda Hiroyuki
Published: February 2011

Effective surface modification with biocompatible molecules is known to be effective in reducing the life‐threatening risks related to artificial cardiovascular implants. In recent strategies in regenerative medicine, the enhancement and support of natural repair systems at the site of injury by designed biocompatible molecules have succeeded in rapid and effective injury repair. Therefore, such a strategy could also be effective for rapid endothelialization of cardiovascular implants to lower the risk of thrombosis and stenosis. To achieve this enhancement of the natural repair system, a biomimetic molecule that mimics proper cellular organization at the implant location is required. In spite of the fact that many reported peptides have cell‐attracting properties on material surfaces, there have been few peptides that could control cell‐specific adhesion. For the advanced cardiovascular implants, peptides that can mimic the natural mechanism that controls cell‐specific organization have been strongly anticipated. To obtain such peptides, we hypothesized the cellular bias toward certain varieties of amino acids and examined the cell preference (in terms of adhesion, proliferation, and protein attraction) of varieties and of repeat length on SPOT peptide arrays. To investigate the role of specific peptides in controlling the organization of various cardiovascular‐related cells, we compared endothelial cells (ECs), smooth muscle cells (SMCs), and fibroblasts (FBs). A clear, cell‐specific preference was found for amino acids (longer than 5‐mer) using three types of cells, and the combinational effect of the physicochemical properties of the residues was analyzed to interpret the mechanism. Copyright © 2011 European Peptide Society and John Wiley & Sons, Ltd.
Folding and assembly of TMD 6‐related segments of DMT 1 in trifluoroethanol aqueous solution
Authors: Xiao Shuyan , Wang Chunyu , Li Jiantao , Li Fei
Published: February 2011

Divalent metal‐ion transporter 1 (DMT1) belongs to a large class of metal‐ion transporters that drive the translocation of a wide range of divalent metal substrates across membranes toward the cytosol with couple of protons. Two highly conserved histidines in the sixth transmembrane domain (TMD6) are essential for metal transport activity in DMT1. In the present study, we determine the high‐resolution structures of three 25‐residue peptides, corresponding to TMD6 of the wildtype DMT1 (the segment 255–279) and its H267A and H272A mutants, in 30% TFE‐d2 aqueous solution by the combined use of circular dichroism (CD) and NMR spectroscopies. The wildtype peptide forms an ‘α‐helix‐extended segment‐α‐helix’ structure with two helices spanning over Gly258–Ala262 and Met265–Lys277 linked by a hinge at residues Val263–Ile264. The H267A mutation reduces the hinge to one residue (Ile264), while the H272A mutation extends the flexible region of the central part from Val263 to His267. Diffusion‐ordered spectroscopy (DOSY) study demonstrates that all the peptides are self‐assembly as trimer in 30% TFE‐d2 aqueous solution. The H272A substitution decreases the intermolecular interaction whereas the H267A substitution may enhance the intermolecular interaction. The specific structure of the discontinuous helix and the self‐assembly feature of DMT1–TMD6 may be crucial for its biological function. The changes in conformation and intermolecular interaction induced by histidine substitution may be correlated with the deficiency of DMT1 in metal‐ion permeation. Copyright © 2011 European Peptide Society and John Wiley & Sons, Ltd.
Neuropeptide Y receptors: ligand binding and trafficking suggest novel approaches in drug development
Authors: Walther Cornelia , Mörl Karin , Beck‐Sickinger Annette G.
Published: February 2011

NPY, PYY and PP constitute the so‐called NPY hormone family, which exert its biological functions in humans through YRs (Y1, Y2, Y4 and Y5). Systematic modulation of YR function became important as this multireceptor/multiligand system is known to mediate various essential physiological key functions and is involved in a variety of major human diseases such as epilepsy, obesity and cancer. As several YRs have been found to be overexpressed on different types of malignant tumors they emerge as promising target in modern drug development. Here, we summarize the current understanding of YRs function and the molecular mechanisms of ligand binding and trafficking. We further address recent advances in YR‐based drug design, the development of promising future drug candidates and novel approaches in YR‐targeted tumor diagnostics and therapy opportunities. Copyright © 2011 European Peptide Society and John Wiley & Sons, Ltd.
Characterization of crystalline silicon on glass using photoluminescence
Authors: Mchedlidze Teimuraz , Schneider Jens , Arguirov Tzanimir , Kittler Martin
Published: February 2011

Thin film of amorphous Si deposited on glass substrate was crystallized at 600 °C using solid phase crystallization and further processed for PV application using Crystalline Silicon on Glass technology. The resulting film was polycrystalline and contained dislocations in large density. Photoluminescence (PL) and SunsVoc measurements were applied for characterization of the material properties. The intensity of radiative transitions related to dislocations (DRL) measured at room temperature supplied information about specificities of non‐radiative recombination in the material and nicely correlated with open circuit voltage, measured using SunsVoc method. The PL measurements at room temperature showed a capability of fast and reliable prediction of PV performance of the film. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Scanning probe studies of amorphous silicon subjected to laser annealing
Authors: Ratzke M. , Mchedlidze T. , Arguirov T. , Acharya N. , Kittler M. , Reif J.
Published: February 2011

The process of light induced solid phase crystallization (LISPC) of thin layers of amorphous silicon (a‐Si) embedded in silicon oxide (SiO2) was investigated using Atomic Force Microscopy (AFM). The results achieved by different modes of AFM, namely Phase Contrast Imaging, Lateral Force Mapping and Scanning Kelvin Probe microscopy reveal several steps of light‐matter interaction. There is clear evidence that the very first steps take place inside of the structure leaving the surface pristine.Also, the findings well agree with that achieved by micro Raman spectroscopy yielding information on the local crystalline structure. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Novel imaging techniques for dislocation‐related D1‐photo‐luminescence of multicrystalline Si wafers – two different approaches
Authors: Schmid R. P. , Mankovics D. , Arguirov T. , Mchedlidze T. , Kittler M.
Published: February 2011

Here we report on two different approaches, which allow rapid photoluminescence imaging of dislocation‐related D1, and band‐to‐band radiation on multicrystalline solar cell wafers at room temperature. We compared a new light emitting diode based method with the recently introduced pulsed laser based method. With both techniques we obtained spatially resolved images from 15.6 × 15.6 cm2 wafers originating from different stages of the standard solar cell production process, showing that these techniques are highly interesting for inline quality control. Both methods provide homogeneous illumination over the whole sample area. With a resolution around 300 μm, and a total recording time of ∼45 s, full D1 images could be captured by the new diode technique. The most promising fact was that surface artifacts did not lead to any noticeable disturbance in the D1 image. For acid textured wafers, the pulsed laser based method was clearly in advantage over the continuous diode technique. Possible explanations are discussed in the text. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Illuminated lock‐in thermography at different wavelengths for distinguishing shunts in top and bottom layers of tandem solar cells
Authors: Straube Hilmar , Siegloch Max , Gerber Andreas , Bauer Jan , Breitenstein Otwin
Published: February 2011

We investigate shunting in a micromorph silicon tandem solar module using dark and illuminated lock‐in thermography (DLIT and ILIT). Shunts are identified and quantified using DLIT. We then show how to isolate the layer causing the individual shunts by using white, blue, and infrared excitation spectra for the pulsed illumination in ILIT. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Growth of zinc oxide nanostructures via thermal oxidation of DC‐sputtered zinc films
Authors: Abdallah Amir , Tabet Nouar , Dastageer Mohamed , Said Syed
Published: February 2011

Zinc oxide (ZnO) nanostructures have been obtained by thermal oxidation of DC‐ sputtered Zinc film (Zn) above the melting temperature of Zinc. The zinc film is directly deposited on the glass substrate or on a ZnO layer pre‐deposited on the glass by DC reactive plasma. The films were characterized by X‐ray Diffraction before and after oxidation treatment. Field Emission Scanning Electron Microscopy (FE‐SEM) revealed the formation of needlelike and nanostructured network. The optical properties of the obtained nanostructures were studied using UV‐VIS‐NIR spectrophotometer. The results showed that the presence of pre‐deposited ZnO layer on the glass substrate improves significantly the transmittance of the obtained layered structure. Photoluminescence results showed the presence of a weak near band edge emission at 3.35 eV and a defect band which is much broader than that observed in pure Zinc Oxide (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Electrical characterization of silicon wafer bonding interfaces by means of voltage dependent light beam and electron beam induced current and capacitance of Schottky diodes
Authors: Trushin M. , Vyvenko O. , Mchedlidze T. , Reiche M. , Kittler M.
Published: February 2011

Schottky diodes prepared on silicon bonded wafers with dislocation network (DN) lying parallel to the sample surface at the depth of ∼2 μm were investigated by means of capacitance‐voltage (CV), current‐voltage (IV) measurements at 80 K under optical illumination. A model of the interpretation of CV and IV data is presented and discussed. It is shown that electron‐beam induced current (EBIC) mapping under the proper chosen forward bias voltages allows one to trace the inhomogeneities of the potential barrier at DN. The observed non‐uniformity of the DN barrier heights was ascribed to inhomogeneous distribution of small oxide precipitates lying at the dislocation network plane (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Immediate impact of a robotic kidney surgery course on attendees practice patterns
Authors: Altunrende Fatih , Autorino Riccardo , Haber Georges‐Pascal , Laydner Humberto , White Michael A. , Khanna Rakesh , Stein Robert J. , Kaouk Jihad H.
Published: February 2011

Background

The object of this study was to evaluate the immediate impact of a robotic kidney surgery course on the practice patterns of participating urologists.

Methods

Two surveys were administered to the participants of the International Symposium on Robotic Kidney and Adrenal Surgery held at the Cleveland Clinic on October 2009. Returned responses were entered into a database. Results were reviewed and analyzed.

Results

Twenty‐seven participants (60% of total registered) completed the end‐of‐course questionnaire. Mean age was 44 years (range 33–65). Mean time from completion of residency was 14 years (range 1–30). The majority of the attendees (78%) had familiarity with both laparoscopy and robotics, but only 22% of them had completed a formal fellowship or mini‐residency training in laparoscopy or robotics. All course components received a mean score above 4.5. 92% of the participants planned to perform a ‘new’ procedure in their practice immediately after the course. Of the 27 participants contacted, 12 (44.4%) returned the 3‐month questionnaire. All of them (100%) had performed robotic surgical procedures after the course. Overall, there was an increase of 56% in the robotic cases in the surgical practice of the participants. The actual impact of attending the course on starting or implementing robotic surgery practice was positively rated by the participants (mean score 4.7 ± 0.45 on scale 1–5).

Conclusions

A course including lectures, video analysis, live surgery and hands‐on session with both simulators and an animal laboratory is an effective educational model for immediately spreading robotic skills. Copyright © 2011 John Wiley & Sons, Ltd.