bluuebunny/crossref_metadata_2025 huggingface dataset:
Photochemical Generation and Structure of Vinyl Radicals
Authors: Goumans Theodorus P. M. , van Alem Kaj , Lodder Gerrit
Published: December 2007

Photolysis of a series ofEorZstereoisomeric α‐R‐substituted bromostyrenes (R = CH3, F or CN) in methanol yieldsEand/orZstereoisomeric styrenes, which stem from the corresponding vinyl radicals. The results show that the α‐Me vinyl radical is a rapidly equilibrating, bent structure, while the α‐F vinyl radical is a stable bent species, in agreement with earlier thermal results. The α‐CN vinyl radical is assigned as a rapidly inverting bent and not a linear species from the stereochemical results as a function of temperature. Stereochemical data for the α‐C(H)=O system in diethyl ether indicate a stable bent vinyl radical as product forming species. The conclusions are supported by quantum chemical computations.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
The Electrocatalytic Properties of Arc‐MWCNTs and Associated ‘Carbon Onions’
Authors: Henstridge Martin C. , Shao Lidong , Wildgoose Gregory G. , Compton Richard G. , Tobias Gerard , Green Malcolm L. H.
Published: December 2007

For the first time we report on the electrochemical characteristics of nanometer sized polyhedral graphite onions dispersed amongst arc‐MWCNTs. These are formed during the electric arc discharge method of producing ultrapure MWCNTs (arc‐MWCNTs). The carbon onions are randomly dispersed amongst the arc‐MWCNTs which are produced with very little amorphous carbon deposits or other unwanted impurities and are formed as closed‐ended tubes. By comparison with commercially available open‐ended hollow‐tube multiwalled carbon nanotubes made using the chemical vapor deposition method (cvd‐MWCNTs), a glassy carbon electrode (GCE), an edge‐plane pyrolytic graphite electrode (eppg) and basal plane pyrolytic graphite (bppg) electrode, we can speculate that it is the edge‐plane‐like defect sites that are the electroactive sites responsible for the apparent ‘electrocatalysis’ seen with a wide range of analytes including: ferrocyanide, ruthenium hexaamine(III), nicotinamide adenosine dinucleotide (NADH), epinephrine, norepinephrine, cysteine, and glutathione. The arc‐MWCNTs themselves are produced as closed‐ended tubes with very few, if any, edge‐plane‐like defect sites evident in their HRTEM characterization. Therefore we speculate that it is the carbon onions dispersed amongst the arc‐MWCNTs which have incomplete graphite shells or a rolled‐up ‘Swiss‐roll’ structures that posses the edge‐plane‐like defect sites and are responsible for the observed voltammetric responses. Carbon onions are no more or no less ‘electrocatalytic’ than open‐ended MWCNTs which in turn are no more electrocatalytic than an eppg electrode. As the carbon onions are ubiquitous in MWCNTs formed using the arc‐discharge method the authors advise that caution should be taken before assigning any electrocatalytic behavior to the MWCNTs themselves as any observed electrocatalysis likely arises from the carbon onion impurities.
Determination of Maleic Hydrazide in Potato Samples Using Capillary Electrophoresis with Dual Detection (UV‐Electrochemical)
Authors: Chicharro M. , Bermejo E. , Ongay S. , Zapardiel A.
Published: December 2007

A new method for the separation of a mixture of different herbicides (propham, chlorpropham, asulam, metamitron, linuron, and maleic hydrazide) using MEKC is proposed. A base‐line separation for the mixture of herbicides is achieved in less than six minutes. The detection limits obtained for all the herbicides were lower than 1.0 μM using UV detection. This separation method was used for the determination of maleic hydrazide in potato samples. If a dual (UV‐electrochemical) detection system is employed, chlorpropham can be also detected. The results obtained showed that electrochemical detection was ten folds more sensitive than UV detection for maleic hydrazide. The detection limit of the proposed method for maleic hydrazide employing electrochemical detection was 1.3 μg g−1, this value is lower than 50 μg g−1, which is the maximum residue level permitted for this plant growth regulator in potato samples. The results obtained in the work clearly demonstrate the advantage of using electrochemical detection coupled to capillary electrophoresis, using this detection the concentration limits are not compromised by miniaturization and the components required are simple and inexpensive.
Dechlorination of Pesticides by a Specific Bacterial Glutathione S‐transferase, BphKLB400: Potential for Bioremediation
Authors: McGuinness M. C. , Mazurkiewicz V. , Brennan E. , Dowling D. N.
Published: December 2007

The bphK gene located in the bph operon of Burkholderia xenovorans LB400 encodes a protein, BphKLB400, with significant sequence similarity to glutathione‐S‐transferases (GSTs). GSTs are a superfamily of enzymes involved in the detoxification of many endobiotic and xenobiotic substances. Recently, BphKLB400 was shown to catalyze the dechlorination of a number of toxic chlorinated organic compounds. Comparison of the amino acid sequence of BphKLB400 with GSTs from other bacteria that degrade polychlorinated biphenyls identified a number of highly conserved amino acids in the C‐terminal region of the protein thought to be associated with substrate specificity. Mutating the conserved amino acid at position 180 of BphKLB400 from an alanine to a proline residue resulted in an increase in GST activity of bacterial cell extracts towards a number of chlorinated organic substrates tested including commonly used pesticides. Laboratory scale plant protection experiments suggested that E. coli expressing BphKLB400 [wildtype and mutant (Ala180Pro)] could protect pea plants from the effects of chloromequat chloride. Therefore, BphKLB400, identified as having dechlorination activity towards toxic chlorinated organic compounds used in the environment, could have potential in bioremediation.
Bayesian analysis of dynamic factor models: an application to air pollution and mortality in São Paulo, Brazil
Authors: Sáfadi T. , Peña D.
Published: December 2007

The Bayesian estimation of a dynamic factor model where the factors follow a multivariate autoregressive model is presented. We derive the posterior distributions for the parameters and the factors and use Monte Carlo methods to compute them. The model is applied to study the association between air pollution and mortality in the city of São Paulo, Brazil. Statistical analysis was performed through a Bayesian analysis of a dynamic factor model. The series considered were minimal temperature, relative humidity, air pollutant of PM10 and CO, mortality circulatory disease and mortality respiratory disease. We found a strong association between air pollutant (PM10), Humidity and mortality respiratory disease for the city of São Paulo. Copyright © 2007 John Wiley & Sons, Ltd.
Enhanced process monitoring for wastewater treatment systems
Authors: Yoo Chang Kyoo , Villez Kris , Van Hulle Stijn W.H. , Vanrolleghem Peter A.
Published: December 2007

Wastewater treatment plants (WWTPs) remain notorious for poor data quality and sensor reliability problems due to the hostile environment, missing data problems and more. Many sensors in WWTP are prone to malfunctions in harsh environments. If a WWTP contains any redundancy between sensors, monitoring methods with sensor reconstruction such as the proposed one can yield a better monitoring efficiency than without a reconstruction scheme. An enhanced robust process monitoring method combined with a sensor reconstruction scheme to tackle the sensor failure problems is proposed for biological wastewater treatment systems. The proposed method is applied to a single reactor for high activity ammonia removal over nitrite (SHARON) process. It shows robust monitoring performance in the presence of sensor faults and produces few false alarms. Moreover, it enables us to keep the monitoring system running in the case of sensor failures. This guaranteed continuity of the monitoring scheme is a necessary development in view of real‐time applications in full‐scale WWTPs. Copyright © 2007 John Wiley & Sons, Ltd.
Spatial variation of wetlands and flux of dissolved organic carbon in boreal headwater streams
Authors: Andersson Jan‐Olov , Nyberg Lars
Published: December 2007

In order to investigate the relation between water chemistry and functional landscape elements, spatial data sets of characteristics for 68 small (0·2–1·5 km2) boreal forest catchments in western central Sweden were analysed in a geographical information system (GIS). The geographic data used were extracted from official topographic maps. Water sampled four times at different flow situations was analysed chemically. This paper focuses on one phenomenon that has an important influence on headwater quality in boreal, coniferous forest streams: generation and export of dissolved organic carbon (DOC). It is known that wetland cover (bogs and fens) in the catchment is a major source of DOC. In this study, a comparison was made between a large number of headwater catchments with varying spatial locations and areas of wetlands. How this variation, together with a number of other spatial variables, influences the DOC flux in the streamwater was analysed by statistical methods. There were significant, but not strong, correlations between the total percentages of wetland area and DOC flux measured at a medium flow situation, but not at high flow. Neither were there any significant correlations between the percentage of wetland area connected to streams, nor the percentage of wetland area within a zone 50 m from the stream and the DOC flux. There were, however, correlations between catchment mean slope and the DOC flux in all but one flow situations. This study showed that, considering geographical data retrieved from official sources, the topography of a catchment better explains the variation in DOC flux than the percentage and locations of distinct wetland areas. This emphasizes the need for high‐resolution elevation models accurate enough to reveal the sources of DOC found in headwater streams. Copyright © 2007 John Wiley & Sons, Ltd.
Serum soluble Fas levels and prediction of response to platinum‐based chemotherapy in epithelial ovarian cancer
Authors: Chaudhry Parvesh , Srinivasan Radhika , Patel Firuza D , Gopalan Sarala , Majumdar Siddhartha
Published: December 2007

Epithelial ovarian cancer (EOC) is treated mainly by platinum‐based combination chemotherapy. Chemotherapy induces apoptosis in which the Fas/Fas ligand pathway is important. Serum soluble Fas (sFas) is a biomarker of this pathway and functionally inhibits Fas‐/FasL‐mediated apoptosis. In this study, we have investigated the role of sFas in prediction of response to chemotherapy in EOC. Thirty‐five patients were recruited and their serum sFas levels were estimated by ELISA at 4 time points—preoperative (sFas1), postoperative (sFas2), midchemotherapy (sFas3) and at the end of chemotherapy (sFas4). The response to chemotherapy was documented clinically, radiologically and by CA‐125 levels, based on which, 2 groups were identified: primary chemosensitive (n = 24) and primary chemoresistant (n = 11). Based on the disease status at last follow‐up, 2 groups were identified: No Evidence of Disease (n = 15) and Evidence of Disease (n = 20). The primary chemoresistant tumors showed significantly higher median sFas2 levels (p = 0.033) with the sFas2/sFas1 ratio ≥1 (p = 0.001). A multivariate Cox proportional hazards regression model identified sFas2/sFas1 ratio as a significant factor for the prediction of response to platinum‐based chemotherapy (p = 0.011). Receiver operating characteristic (ROC) analysis showed that at a ratio of 1.2, sFas2/sFas1 achieved a sensitivity of 82% and specificity of 100% for prediction of chemotherapeutic response. sFas2/sFas1 and sFas3/sFas1 ratio was also higher in patients with evidence of disease (p = 0.018 and p = 0.028, respectively). Progression‐free survival rates in patients with sFas2/sFas1 ratio <1 exceeded those with ratio ≥1 (p = 0.004). In conclusion, serum sFas is a useful biomarker for predicting response to platinum‐based chemotherapy in EOC. © 2007 Wiley‐Liss, Inc.
Plasma vitamin B12 concentrations and the risk of colorectal cancer: A nested case‐referent study
Authors: Dahlin Anna M. , Van Guelpen Bethany , Hultdin Johan , Johansson Ingegerd , Hallmans Göran , Palmqvist Richard
Published: December 2007

In this nested case‐referent study, we related plasma concentrations of vitamin B12 to the risk of colorectal cancer, taking into consideration prediagnostic plasma folate and total homocysteine concentrations. Subjects were 226 cases and double matched referents from the population‐based Northern Sweden Health and Disease Study. Follow‐up times from recruitment to diagnosis ranged from 0.1 to 12.7 years, with a median of 4.2 years. Plasma vitamin B12 concentrations were inversely associated with the risk of rectal cancer: univariate odds ratio for the highest versus lowest quintile 0.34 (95% confidence interval (95% CI) 0.13–0.83), ptrend = 0.004. Risk estimates were attenuated slightly but remained statistically significant after adjustment for body mass index, current smoking, recreational and occupational physical activity, alcohol intake and prediagnostic plasma folate and total homocysteine concentrations: OR 0.30 (95% CI 0.08–0.99), ptrend = 0.025. The corresponding univariate and fully adjusted odds ratios for colon cancer were 1.25 (CI 0.66–2.36), ptrend = 0.185 and 1.42 (CI 0.67–3.05), ptrend = 0.113, respectively. The observed over‐risk was attributable to left‐sided colon cancer. Interaction analyses including vitamin B12, folate and homocysteine were in line with the results for vitamin B12 alone. In conclusion, these results suggest that increasing levels of plasma vitamin B12, alone or together with other factors involved in one‐carbon metabolism, may reduce the risk of rectal cancer, whereas for colon cancer, the association appears to be less clear. © 2007 Wiley‐Liss, Inc.
Interaction of estrogen therapy with calcium and vitamin D supplementation on colorectal cancer risk: Reanalysis of Women's Health Initiative randomized trial
Authors: Ding Eric L. , Mehta Saurabh , Fawzi Wafaie W. , Giovannucci Edward L.
Published: December 2007

Although calcium and vitamin‐D intake were consistently shown to be inversely associated with colorectal cancer risk in several large prospective studies and protective against adenoma and cancer in multiple randomized trials, the Women's Health Initiative (WHI) of calcium and low‐dose vitamin‐D supplementation trial found no overall effects on colorectal cancer. However, the previous report did not recognize an important biologic interaction with estrogen therapy. We investigated the treatment interaction of estrogen with calcium and vitamin‐D on risk of colorectal cancer via a reanalysis of primary data results from the WHI calcium and vitamin‐D supplementation trial (1,000 mg elemental calcium, 400 IU of vitamin‐D3, or placebo), reanalyzing results from women concurrently randomized to estrogen interventions and placebo. Results indicate that concurrent estrogen therapy was a strong effect modifier of calcium and vitamin‐D supplementation on colorectal cancer risk. While calcium plus vitamin‐D supplementation among women concurrently assigned to estrogen therapies suggested increased risk (Hazard Ratio = 1.50, 95% CI: 0.96–2.33), among women concurrently assigned to placebos arms of the estrogen trials, calcium plus vitamin‐D indicated suggestive benefits (HR = 0.71, 95% CI: 0.46–1.09) (p‐for‐estrogen‐interaction = 0.018). Consistent interaction was also found by reported estrogen use (p interaction = 0.037). Results indicate contrasting effects of calcium and vitamin‐D by concurrent estrogen therapy on colorectal cancer risk. Although further clinical and mechanistic studies are warranted, the potential clinical implications of the apparent interaction of estrogen therapy with calcium and vitamin‐D supplementation should be recognized. Important biological mechanisms related to the key membrane receptor megalin and estrogen‐dependent protein calbindin are discussed. © 2007 Wiley‐Liss, Inc.
Experimental anti‐angiogenesis causes upregulation of genes associated with poor survival in glioblastoma
Authors: Saidi Ahlame , Javerzat Sophie , Bellahcène Akeila , De Vos John , Bello Lorenzo , Castronovo Vincent , Deprez Manuel , Loiseau Hugues , Bikfalvi Andreas , Hagedorn Martin
Published: December 2007

Vascular endothelial growth factor (VEGF) inhibitors are the most promising anti‐angiogenic agents used increasingly in the clinic. However, to be efficient, anti‐VEGF agents need to be associated with classic chemotherapy. Exploring gene regulation in tumor cells during anti‐angiogenesis might help to comprehend the molecular basis of response to treatment. To generate a defined anti‐angiogenic condition in vivo, we transfected human glioma cells with short‐interfering RNAs against VEGF‐A and implanted them on the chick chorio‐allantoic membrane. Gene regulation in avascular tumors was studied using human Affymetrix™ GeneChips. Potentially important genes were further studied in glioma patients. Despite strong VEGF inhibition, we observed recurrent formation of small, avascular tumors. CHI3L2, IL1B, PI3/elafin and CHI3L1, which encodes for YKL‐40, a putative prognosticator for various diseases, including cancer, were strongly up‐regulated in avascular glioma. In glioblastoma patients, these genes showed coregulation and their expression differed significantly from low‐grade glioma. Importantly, high levels of CHI3L1 (p = 0.036) and PI3/elafin mRNA (p = 0.0004) were significantly correlated with poor survival. Cox regression analysis further confirmed that PI3 and CHI3L1 levels are survival markers independent from patient age and sex. Elafin‐positive tumor cells were only found in glioblastoma, where they were clustered around necrotic areas. PI3/elafin is strongly induced by serum deprivation and hypoxia in U87 glioma cells in vitro. Our results indicate that anti‐angiogenesis in experimental glioma drives expression of critical genes which relate to disease aggressiveness in glioblastoma patients. In particular, CHI3L1 and PI3/elafin may be useful as new prognostic markers and new therapeutic targets. © 2007 Wiley‐Liss, Inc.
Mutant p53R270H gain of function phenotype in a mouse model for oncogene‐induced mammary carcinogenesis
Authors: Heinlein Christina , Krepulat Frauke , Löhler Jürgen , Speidel Daniel , Deppert Wolfgang , Tolstonog Genrich V.
Published: December 2007

In human breast cancer, mutations in the p53 gene are associated with poor prognosis. However, analysis of patient data so far did not clarify, whether missense point mutations in the p53 gene, in addition to causing loss of wild‐type p53 function, also confer a gain of function phenotype to the encoded mutant p53. As heterogeneity of patient material and data might obscure a clear answer, we studied the effects of a coexpressed mutant p53R270H in transgenic mice in which SV40 early proteins initiate the development of mammary adenocarcinoma (WAP‐T mice). In such tumors the endogenous wild‐type p53 is functionally compromised by complex formation with SV40 T‐antigen, thereby constituting a loss of wild‐type p53 function situation that allowed analysis of the postulated gain of function effects of mutant p53R270H. We found that mutant p53R270H in bi‐transgenic mice enhanced the transition from intraepithelial neoplasia to invasive carcinoma, resulting in a higher frequency of invasive carcinoma per gland and per mouse, a more severe tumor phenotype, and more frequent pulmonary metastasis. Surprisingly, mutant p53R270H in this system does not increase genomic instability. Therefore, other postulated gain of function activities of mutant p53 must be responsible for the effects described here. © 2007 Wiley‐Liss, Inc.
Interactions between stainless steel, shear stress, and monocytes
Authors: Messer Regina L. W. , Mickalonis John , Lewis Jill B. , Omata Yo , Davis Cortney M. , Brown Yolanda , Wataha John C.
Published: December 2007

Angioplasty with stent placement is commonly used to treat coronary atherosclerosis. However, 20–40% of stainless steel stents restenose within 6 months via a prolonged inflammatory response mediated by monocytic infiltration and cytokine secretion. In the current study, we tested a hypothesis that blood flow and monocytes interact to alter stent corrosion. We assessed the effects of THP1 monocytes on the corrosion rate of 316L stainless steel (316LSS) under shear stress (0.5–50 dyn/cm2). In addition, THP1 cytokine secretion was determined using cytokine arrays and ELISA analyses. Data were compared using ANOVA and Tukey post hoc analysis (α = 0.05). Monocytes significantly lowered 316LSS corrosion rates without limiting current density. However, shear stress alone did not alter the corrosion rate of 316LSS. THP1 cells adhered to the 316LSS surface at all flow rates. Exposure to the 316LSS/corrosion test under high fluid flow rates increased (>twofold) the secretion of 7 of the 42 cytokines tested (angeogenin, GRO, I309, interleukin 8, interleukin 6, interleukin 1β, and macrophage chemoattractant protein‐1). Each of these cytokines play a role in wound healing, macrophage differentiation, and cell proliferation, all hallmarks of in‐stent restenosis. Furthermore, only IL8 levels were significantly higher than any of the system controls during the 316LSS/corrosion test conditions. The IL8 levels from the 316LSS/corrosion tests were not significantly different from the +LPS control. Together, these data suggest that monocytic cells maybe activated by exposure to 316LSS stents and could contribute to in‐stent restenosis and altered corrosion of the stent. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2008
Morphology controllable nanostructured chitosan matrix and its cytocompatibility
Authors: Qi Lifeng , Pal Susmita , Dutta Prasanta , Seehra Mohindar , Pei Ming
Published: December 2007

It is becoming clear that surface nanotopography of underlying substrates can influence cell behavior such as adhesion, proliferation, and orientation of mammalian cells. Nanofabrication methods such as electron beam lithography are, however, expensive and time consuming. In this study, a simple and cost‐effective approach, heterogeneous seeded growth, was developed to create nanostructured chitosan matrix (CSM) from amorphous chitosan nanoparticles (CNPs). The physiochemical properties of CSM were characterized followed by an evaluation of CSM cytocompatibility. Shape‐controllable morphology of CSM from nanoparticles to three‐dimensional urchin‐like architectures was achieved by using varying amounts of seeds. CSM was found to be cytocompatible with human foreskin fibroblasts suggesting that the nanofibrous surface morphology and crystalline structure of CSM could favor cell spread and growth. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res 2008
Modulation of expression of LDH isoenzymes in endothelial cells by laminin: Implications for angiogenesis
Authors: Kumar V.B. Sameer , Viji R.I. , Kiran M.S. , Sudhakaran P.R.
Published: December 2007

Endothelial cell (EC) matrix interaction is critical in angiogenesis. Although matrix components can regulate the process of angiogenesis by acting as a reservoir of various cytokines, it is not clear if extracellular matrix (ECM) can modulate the production and activity of angiogenic cytokines. Investigations were therefore carried out to study the influence of the basement membrane (BM) protein, laminin (Ln) on the activity of vascular endothelial growth factor (VEGF), the major angiogenic cytokine, using isolated human umbilical vein ECs (HUVECs) in culture. Analysis of the biochemical markers of angiogenesis confirmed proangiogenic effect of Ln. The levels of VEGF protein and mRNA were not different in cells maintained on Ln, collagen I or polylysine substrata. Chorioallantoic membrane assay using VEGF isolated from cell extracts however revealed that Ln increased its angiogenic potency. Immunoblotting and HPLC analysis showed considerable reduction in poly adenosyl ribosylation of VEGF associated with a significant decrease in the levels of NAD+, in cells maintained on Ln substrata. Further, a shift in the isoenzymic pattern of LDH towards the B rich forms and an upregulation of LDH B gene were observed in cells maintained on Ln. Ln modulates expression of LDH gene through α6β4 integrin mediated downstream signaling involving p38 mitogen activated protein kinases (MAPK) pathway. It thus appears that Ln can affect aerobic metabolism of ECs by modulating the expression of LDH isoenzymes resulting in a decrease in the level of NAD+ that can cause a reduction in the poly adenosyl ribosylation of VEGF altering its angiogenic potency. J. Cell. Biochem. 103: 1808–1825, 2008. © 2007 Wiley‐Liss, Inc.
Bioactive food components and cancer risk reduction
Authors: Stan Silvia D. , Kar Siddhartha , Stoner Gary D. , Singh Shivendra V.
Published: December 2007

Research over the last three decades has provided convincing evidence to support the premise that diets rich in fruits and vegetables may be protective against the risk of different types of cancers. Initial evidence for protective effect of fruits and vegetables against cancer risk came from population‐based case‐control studies, which prompted intense research aimed at (a) identification of bioactive component(s) responsible for the anticancer effects of fruits and vegetables, (b) elucidation of the mechanisms by which bioactive food components may prevent cancer, and (c) determination of their efficacy for prevention of cancer in animal models. The bioactive components responsible for cancer chemopreventive effects of various edible plants have now been identified. For instance, anticancer effect ofAlliumvegetables including garlic is attributed to organosulfur compounds (e.g., diallyl trisulfide). Interestingly, unlike cancer chemotherapy drugs, many bioactive food components selectively target cancer cells. Molecular basis for selectivity of anticancer bioactive food components towards cancer cells remains elusive, but these agents appear promiscuous and target multiple signal transduction pathways to inhibit cancer cell growth in vitro and in vivo. Despite convincing observational and experimental evidence, however, limited effort has been directed towards clinical investigations to determine efficacy of bioactive food components for prevention of human cancers. This article reviews current knowledge on cancer chemopreventive effects of a few highly promising dietary constituents, including garlic‐derived organosulfides, berry compounds, and cruciferous vegetable‐derived isothiocyanates, and serves to illustrate complexity of the signal transduction mechanisms in cancer chemoprevention by these promising bioactive food components. J. Cell. Biochem. 104: 339–356, 2008. © 2007 Wiley‐Liss, Inc.
Differential effects of chemotherapeutic drugs versus the MDM‐2 antagonist nutlin‐3 on cell cycle progression and induction of apoptosis in SKW6.4 lymphoblastoid B‐cells
Authors: Barbarotto Elisa , Corallini Federica , Rimondi Erika , Fadda Roberto , Mischiati Carlo , Grill Vittorio , Vaccarezza Mauro , Celeghini Claudio
Published: December 2007

We have compared the cytotoxic/cytostatic responses of the SKW6.4 lymphoblastoid B‐cells to the alkylating agent chlorambucil, the purine analog fludarabine, the non‐genotoxic activator of the p53 pathway, Nutlin‐3, used alone or in association with the death‐inducing ligand recombinant TRAIL. Exposure to chlorambucil, fludarabine, and Nutlin‐3 induced p53 accumulation and variably affected cell cycle progression in SKW6.4 lymphoblastoid cells. In particular, chlorambucil induced cell cycle accumulation at the G2/M checkpoint; Nutlin‐3 induced early cell cycle arrest at the G1/S checkpoint, while fludarabine showed an intermediate behavior. On the other hand, recombinant TRAIL alone did not affect cell cycle progression but induced a rapid increase of apoptosis. Analysis of the gene expression profile of the p53‐transcriptional targets showed distinct features between chlorambucil, Nutlin‐3 and fludarabine, which likely account for their differential effect on cell cycle in SKW6.4 cells. In particular, chlorambucil upregulated the steady‐state mRNA expression of SFN/14‐3‐3σ, a gene involved in G2/M cell cycle arrest. Of note, all agonists upregulated TRAIL‐R2 expression in SKW6.4 cells both at the mRNA and protein levels. Consistently, pretreatment with chlorambucil, fludarabine and Nutlin‐3 enhanced SKW6.4 sensitivity to TRAIL‐mediated apoptosis. J. Cell. Biochem. 104: 595–605, 2008. © 2007 Wiley‐Liss, Inc.
Contrast‐enhanced sonography in the diagnosis of small hepatocellular carcinoma ≤2 cm
Authors: Xu Hui‐Xiong , Xie Xiao‐Yan , Lu Ming‐De , Liu Guang‐Jian , Xu Zuo‐Feng , Zheng Yan‐Lin , Liang Jin‐Yu , Chen Li‐Da
Published: December 2007

Purpose

To evaluate the usefulness of contrast‐enhanced sonography (CEUS) in the diagnosis of small hepatocellular carcinoma (HCC) measuring ≤2 cm in diameter.

Methods

We identified 104 focal liver lesions measuring ≤2 cm in 104 consecutive patients who were enrolled for baseline sonography (BUS) and CEUS examination (49 HCCs, 55 non‐HCCs). A real‐time, contrast‐specific mode of contrast pulse sequencing and a sulphur hexafluoride‐filled microbubble contrast agent were used for CEUS. The diagnostic performances of BUS and CEUS in differentiating focal liver lesions (HCC or non‐HCC) were analyzed and compared.

Results

On CEUS, 43 (87.8%) of the 49 HCC lesions were hyperenhanced, 5 (10.2%) were isoenhanced, and 1 (2%) was hypoenhanced during the arterial phase when compared with adjacent liver tissue. Thirty‐nine (79.6%) HCCs exhibited washout from the portal phase to the late phase. The sensitivity, specificity, positive predictive value, negative predictive value, and overall accuracy before and after contrast agent administration were 28.6% (14/49) versus 79.6% (39/49) (p < 0.001), 94.5% (52/55) versus 92.7% (51/55) (p > 0.05), 82.4% (14/17) versus 90.7% (39/43) (p > 0.05), 59.8% (52/87) versus 90.7% (39/43) (p < 0.01), and 63.5% (66/104) versus 86.5% (90/104) (p < 0.001), respectively. No significant difference in diagnostic performance of CEUS was found between lesions measuring ≤1.5 cm and those 1.6–2 cm and between lesions located at a depth of ≤6 cm from the skin and those located deeper.

Conclusions

CEUS significantly improved the diagnostic performance in characterization of small HCCs ≤2 cm compared with BUS. © 2007 Wiley Periodicals, Inc. J Clin Ultrasound, 2008
Sonographically guided excisional biopsy of small abdominal wall masses using vacuum‐assisted biopsy device
Authors: Park Noh Hyuck , Lee En Ja , Kim Mi Sung , Park Chan Sup , Ryu Jeong A.
Published: December 2007

We report the case of a 37‐year‐old man who underwent excision of small benign abdominal wall masses using a vacuum‐assisted biopsy device designed for breast biopsy (Mammotome®). To our knowledge, this is the first application of such a device to remove a soft tissue mass other than a breast lesion. © 2007 Wiley Periodicals, Inc. J Clin Ultrasound, 2008
Intravenous glial‐derived neurotrophic factor gene therapy of experimental Parkinson's disease with Trojan horse liposomes and a tyrosine hydroxylase promoter
Authors: Xia Chun‐Fang , Boado Ruben J. , Zhang Yun , Chu Chun , Pardridge William M.
Published: December 2007

Background

Rats with experimental Parkinson's disease (PD) are treated with intravenous glial‐derived neurotrophic factor (GDNF) plasmid DNA, non‐viral gene therapy using Trojan horse liposomes (THLs) targeted with a monoclonal antibody (MAb) to the rat transferrin receptor (TfR). Expression of the transgene is confined to catecholaminergic cells by placement of the GDNF gene under the influence of the rat tyrosine hydroxylase (TH) promoter.

Methods

A 13‐kb eukaryotic expression plasmid, designated pTHpro‐GDNF, is engineered in which the human prepro GDNF cDNA is driven by 8 kb of the 5′‐flanking sequence of the rat TH promoter (pro), and is 3′‐flanked by the bovine growth hormone transcription termination sequence. The pTHpro‐GDNF plasmid DNA is encapsulated in THLs targeted with a TfRMAb, and a single intravenous injection is given to rats at 2 weeks after experimental PD is induced by intra‐cerebral 6‐hydroxydopamine.

Results

Expression of the GDNF gene, under the influence of the TH promoter, is restricted compared to GDNF expression under the influence of the cytomegalovirus promoter. GDNF is elevated only in organs of the rat where TH gene expression is observed, including the substantia nigra, liver and adrenal gland. The single, delayed intravenous administration of the GDNF gene therapy causes a lasting reduction in apormorphine‐induced rotation, which is correlated with a 19‐fold increase in striatal TH enzyme activity. Both dose‐response and time‐responses are observed.

Conclusions

Sustained therapeutic effects are achieved in experimental PD with a delayed single intravenous dosing of GDNF plasmid DNA gene therapy, using receptor‐targeted THLs and a region‐specific promoter. Copyright © 2007 John Wiley & Sons, Ltd.
Dorsal genital nerve stimulation for the treatment of overactive bladder symptoms
Authors: Goldman Howard B. , Amundsen Cindy L. , Mangel Jeffrey , Grill Julie , Bennett Maria , Gustafson Kenneth J. , Grill Warren M.
Published: December 2007

Aim

To evaluate percutaneous placement of electrodes adjacent to the dorsal genital nerve (DGN) and measure the effects of electrical stimulation on symptoms of urge incontinence during 1 week of home use.

Methods

Prospective, multicenter study. Subjects with urge incontinence underwent percutaneous placement of an electrode using local anesthetic. Test stimulation was applied to confirm electrode placement and cystometry was conducted with and without application of electrical stimulation. A 7‐day testing period with the electrode connected to an external pulse generator was performed and was followed by a 3‐day post‐treatment test period. Bladder diaries, 24 hr pad tests, and adverse event queries were obtained.

Results

Twenty‐one women were enrolled with an average age of 52.7 years and average duration of incontinence of 6 years. Percutaneous electrode placement required 5–10 min and was well tolerated. There was no relationship between the acute effects of stimulation on cystometry and the results during home use. Pad weight was reduced by ≥ 50% in 13 of 17 subjects (76%) (4 did not complete 24 hr pad testing) and 47% of subjects reported ≥50% reduction in incontinence episodes. Of the subjects who reported severe urgency at baseline, 81% experienced a 50% or greater improvement. Seven subjects experienced nine adverse events ranging from skin irritation to pain and bruising around the electrode exit site.

Conclusions

Electrodes to stimulate the DGN can be placed percutaneously and a home testing period showed a reduction in overactive bladder symptoms with DGN stimulation. Neurourol. Urodynam. 27:499–503, 2008. © 2007 Wiley‐Liss, Inc.
Mechanism of bladder dysfunction in idiopathic normal pressure hydrocephalus
Authors: Sakakibara Ryuji , Kanda Takemasa , Sekido Tetsutoshi , Uchiyama Tomoyuki , Awa Yusuke , Ito Takashi , Liu Zhi , Yamamoto Tatsuya , Yamanishi Tomonori , Yuasa Tatsuhiko , Shirai Koji , Hattori Takamichi
Published: December 2007

Aim

To elucidate the mechanism of bladder dysfunction in idiopathic normal pressure hydrocephalus (iNPH) by a urodynamic study.

Methods

Forty‐two patients with possible iNPH, who were diagnosed by clinical symptoms/signs (gait, cognitive, and urinary disorders) with typical imaging features (ventricular enlargement) and normal cerebrospinal fluid pressure, were enrolled. The subjects included 36 men and 6 women; mean age, 72 years (62–83 years). All patients underwent a urodynamic test according to the definitions and methods proposed by the International Continence Society.

Results

Lower urinary tract symptoms were seen in 93% of the patients, with storage symptoms (93%) being more common than voiding symptoms (71%); and urinary urgency (overactive bladder) (64%)/frequency (64%) being more common than urinary incontinence (57%). The mean values for the maximum flow rate and post‐void residual (PVR) volume were 11.7 ml/sec and 42.1 ml, respectively. PVR >100 ml was noted in six patients (three men, three women; range, 100–228 ml). Although the majority of patients had normal bladder volume at the first sensation (mean 134 ml), bladder capacity was small (mean 200 ml) and detrusor overactivity was seen in 95% of patients.

Conclusions

While incontinence can result secondarily from gait disturbance or dementia, detrusor overactivity mostly underlies urinary urgency/frequency and incontinence in iNPH. Neurourol. Urodynam. 27:507–510, 2008. © 2007 Wiley‐Liss, Inc.
Effect of race on vincristine‐associated neurotoxicity in pediatric acute lymphoblastic leukemia patients
Authors: Renbarger Jamie L. , McCammack Kevin C. , Rouse Caroline E. , Hall Stephen D.
Published: December 2007

Background

This report examines the association between race and vincristine‐associated neurotoxicity in pediatric patients with precursor B cell acute lymphoblastic leukemia (preB ALL). Given that in vitro vincristine is metabolized more efficiently by cytochrome P450 (CYP) 3A5 than by CYP3A4 and that 70% African‐Americans (vs. 20% of Caucasians) express CYP3A5, one may hypothesize that African‐Americans metabolize vincristine more efficiently resulting in lower vincristine exposure and associated‐toxicity.

Procedure

A retrospective analysis of vincristine‐related side effects in pediatric patients treated for preB ALL was performed. Data were compared between Caucasians (n = 92) and African‐Americans (n = 21) to examine the relationship between race and vincristine‐associated neurotoxicity thus using race as a surrogate for CYP3A5 genotype. Race, age, gender, disease subtype, highest grade of vincristine‐associated neurotoxicity (per NIH Common Terminology Criteria for Adverse Events version 3.0), number of omitted and reduced vincristine doses, cumulative vincristine dose, and disease outcome were captured.

Results

34.8% of Caucasians experienced symptoms consistent with vincristine‐related neurotoxicity compared to 4.8% of African‐Americans (P = 0.007). The average grade of neurotoxicity for Caucasians was 2.72 versus grade 1 neurotoxicity in the African‐American (P < 0.0001). Four percent of total doses administered to Caucasian patients were reduced due to vincristine‐related neurotoxicity compared to 0.1% given to African‐Americans (P < 0.0001). 1.2% of all protocol‐indicated doses for Caucasians were held due to severe vincristine‐associated toxicity compared to 0.1% of doses for African‐Americans (P < 0.01).

Conclusions

The data support the hypothesis pharmacogenetic polymorphisms in CYP3A5 expression contribute to variability in vincristine metabolism and neurotoxicity. Pediatr Blood Cancer 2008;50:769–771. © 2007 Wiley‐Liss, Inc.
Räumliche Porträts in Glas. Spielwiese
Authors: Ucke Christian , Schlichting Hans‐Joachim
Published: December 2007

Nichtlineare optische Effekte ermöglichen räumliche Gravuren im Innern eines massiven Glasblocks. Dessen Anblick zeigt außerdem die von Aquarien her bekannten Vervielfältigungen mit und ohne Seitenverkehrungen des Portraits. Schließlich lassen sich durch einen Blick von hinten die faszinierenden Phänomene des Hohlmaskeneffektes untersuchen.
Poly(phenylene sulfide) magnetic composites. I. Relations of percolation between rheology, electrical, and magnetic properties
Authors: Wu Defeng , Wu Lanfeng , Gao Fei , Zhang Ming , Yan Changhao , Zhou Weidong
Published: December 2007

Poly(phenylene sulfide)/ferrosoferric oxide composites (PPS/Fe3O4) with various loading levels were prepared by melt compounding. The microstructure of composites was investigated using SEM and XRD. The rheological, electrical and magnetic properties were characterized respectively by the parallel plate rheometer, high resistance meter, and magnetometer. The results reveal that the Fe3O4 particles are well dispersed in the PPS matrix due to their nice affinity, which results in a weak strain overshoot at large amplitude oscillatory level. Both the rheological and the electrical responses of the composites show a typical percolation behavior. But the rheological percolation presents lower threshold (< 40 wt %) than that of electrical percolation (∼ 50 wt %), which is attributed to the difference structure of the percolation network. The magnetic response, however, shows good linear relation with Fe3O4 loadings, indicating that the physical percolation has little influence on the magnetic properties. This is mainly due to the yielded long‐range magnetic interactions among Fe3O4 particles in the applied field, which are far stronger than those nonmagnetic physical interactions accounting for percolation. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 46: 233–243, 2008
A randomized trial of delayed extubation for the reduction of reintubation in extremely preterm infants
Authors: Danan Claude , Durrmeyer Xavier , Brochard Laurent , Decobert Fabrice , Benani Mohamed , Dassieu Gilles
Published: December 2007

Objective

To compare immediate extubation versus delayed extubation after 36 hr in extremely low‐birth weight infants receiving gentle mechanical ventilation and perinatal lung protective interventions. Our hypothesis was that a delayed extubation in this setting would decrease the rate of reintubation.

Study design/Methodology

A prospective, unmasked, randomized, controlled trial to compare immediate extubation and delayed extubation after 36 hr. Optimized ventilation in both groups included continuous tracheal gas insufflation (CTGI), prophylactic surfactant administration, low oxygen saturation target and moderate permissive hypercapnia. Successful extubation for at least 7 days was the primary criterion and ventilatory support requirements until 36 weeks gestational age the main secondary criteria.

Patient selection

Eighty‐six infants under 28 weeks gestational age in a single neonatal intensive tertiary care unit.

Results

Delayed extubation (1.9 ± 0.8 days vs. 0.5 ± 0.7 days) did not improve the rate of successful extubation but had no long‐term adverse effects. CTGI and the lung protective strategy we describe resulted in a very gentle ventilation. The rate of survival without bronchopulmonary dysplasia (BPD, defined as any respiratory support at 36 weeks gestational age) was similar in the two groups and remarkably high for the global population (78%) and for the subgroup of infants <1,000 g at birth (75%).

Conclusions

Adding 36 hr of optimized mechanical ventilation before first extubation does not improve the rate of successful extubation but has no adverse effects. Pediatr Pulmonol. 2008; 43:117–124. © 2007 Wiley‐Liss, Inc.
A case study of safety integrity level assessment and verification: Electronics division product line evaluation and analysis
Authors: Day John , Thomas Hal , VanOmmeren James
Published: December 2007

With the adoption of IEC 61511 (Functional safety—Safety instrumented systems for the process industry sector) and ANSI/ISA‐84.00.01‐2004 (IEC 61511 Mod, Functional safety: safety instrumented systems for the process industry sector, Parts 1–3) standards, Air Products and Chemicals has made a concerted effort to provide a standardized approach to the design and implementation of safety instrumented systems following the safety lifecycle model. This presentation provides a case study describing the methodology used during the safety integrity level (SIL) assessment and verification of existing electronics division product lines. SIL assessment was accomplished through the use of hazard identification; likelihood, consequence, and risk analysis. Each of the electronics division product's safety instrumented function (SIF) was identified during SIL Assessment, making use of both layer of protection analysis (LOPA) and consequence analysis. A target SIL was determined for each SIF through quantitative and qualitative analysis. SIL Verification was accomplished using fault tree analysis in order to determine the average probability of failure on demand (PFDAVG) of each SIF. This analysis was a joint collaboration between the process safety and process controls engineering teams. © 2007 American Institute of Chemical Engineers Process Saf Prog, 2008
Early biochemical events in leukocyte activation through receptors for IgG
Authors: Ortega Enrique , Soto‐Cruz Isabel
Published: December 2007

Membrane receptors for the Fc portion of IgG antibodies (FcγR) are expressed by most cells of the immune system. Recent research has revealed that, besides their role in effector functions mediated by leukocytes, FcγR also participate in the antibody‐mediated regulation of many phenomena in the afferent phase of immune responses and in the homeostasis of the immune system. Here, we review recent findings on the mechanisms of signal transduction by these receptors as well as on the modulation of FcγR signaling by signal regulators and/or by the activation state of the cell.
Viewpoint: Discriminating between noncompetitive and allosteric interactions
Authors: Ochs Raymond S. , Ashby Charles R.
Published: December 2007

Understanding inhibition modes other than competitive is of clear importance in neuropharmacology. However, there appears to be some confusion concerning modes of inhibition that are not of the competitive type. It is critical to make a distinction between “not competitive” and “noncompetitive,” as the later is a particular mode of inhibition. Further, there appears to be confusion between noncompetitive and allosteric behavior. Our purpose in this contribution is to explore the basis of these terms so that insight into pharmacological systems has a firmer mechanistic basis. Synapse 62:233–235, 2008. © 2007 Wiley‐Liss, Inc.
OPTIMAL CONTROL OF FLEXIBLE SERVERS IN TWO TANDEM QUEUES WITH OPERATING COSTS
Authors: Pandelis Dimitrios G.
Published: December 2007

We consider two-stage tandem queuing systems with dedicated servers in each station and flexible servers that can serve in both stations. We assume exponential service times, linear holding costs, and operating costs incurred by the servers at rates proportional to their speeds. Under conditions that ensure the optimality of nonidling policies, we show that the optimal allocation of flexible servers is determined by a transition-monotone policy. Moreover, we present conditions under which the optimal policy can be explicitly determined.
Can People Read Self-Help Manuals for Depression? A Challenge for the Stepped Care Model and Book Prescription Schemes
Authors: Martinez Rebeca , Whitfield Graeme , Dafters Rebecca , Williams Christopher
Published: December 2007

Self help approaches are increasingly being used in healthcare settings through over 100 book prescription schemes in the UK. The use of Cognitive Behavioural Therapy (CBT) self-help materials for depression is advocated as part of stepped care service models. This study assesses how the reading ages of the most recommended self-help books for depression compare to British literacy levels. A cross sectional survey was carried out. The most recommended self-help books for depression were identified; seven CBT based self-help books were included in this study as well as a widely used booklet for depression. Readability scores and reading ages were calculated for a randomly generated selection representing 15% of each selected book using the Readability Studio® software to generate a wide range of key readability and comprehension scores. The reading ages of the selected books were between 12.6 and 15.4. Reading ease varied amongst the texts, and their complexity (percentage of unfamiliar words, range: 14.8% – 22.6%). A significant proportion of the UK population would struggle to use some of the current CBT-based self-help books recommended. For some patient groups, non text based self-help materials as well as shorter and more easily read written materials may be more appropriate. To our knowledge, this is the first study to address this question. Publication of the reading ages of the recommended books within the book prescription schemes may allow for a more accurate match between the book and the reader.