bluuebunny/crossref_metadata_2025 huggingface dataset:
Surface topography of zirconia implants does not alter action potentials of isolated rat sciatic nerves
Authors: Ertan Ahmet Atila , Çelebi Nilüfer , Bayolken Merve , Onur Mehmet Ali , Aboushelib Moustafa Nabil , Feilzer Albert , Cehreli Murat
Published: July 2008

The purpose of this study was to explore the effects of airborne‐particle abrasion and selective infiltration etching of a yttrium‐partially stabilized tetragonal zirconia polycrystal (Y‐TZP) implant surfaces on nerve conduction. Particle‐abraded Y‐TZP (P/Y‐TZP), selective infiltration etched Y‐TZP (SIE/Y‐TZP), and commercially pure titanium (CP‐Ti) were used in the study (n = 5).The compound action potentials of the right and left sciatic nerves of eight sacrificed rats were quantified at the in vitro level. The implants were brought into intimate contact with the nerves and the time required for initiation of compound action potentials (TcAP), depolarization (Dp), repolarization (Rp), and amplitude of evoked compound action potentials (cAPs) were recorded before and after contact with the implants. The difference in cAPs between the basal response and after contact with CP‐Ti implant was significant (p < 0.05). Time‐dependent changes in cAPs of P/Y‐TZP and SIE/Y‐TZP groups and their basal nerve responses were similar (p > 0.05). Within‐ and between‐subject comparisons revealed that TcAP, Dp, and Rp values for all groups were similar (p > 0.05). Particle‐abraded and selective infiltration‐etched zirconia implant surfaces do not alter nerve conduction beyond physiologic limits. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2009
Comparative study of thein vitrointeraction of two fibroblast cell lines with a polyalkyl‐imide hydrogel
Authors: Dini Luciana , Tenuzzo Bernadetta , Miccoli Maria Antonietta , Miceli Valerio , Protopapa Carmelo , Ramires Piera Angela
Published: July 2008

Thein vitroeffects of polyalkyl‐imide hydrogel (PAI) containing 96% pyrogen‐free water on the viability, apoptosis, cell shape and metabolic activities of murine 3T3 and human Detroit 555 fibroblasts were investigated. Analysis of the viscous‐elastic properties and the ultrastructure of PAI, performed by rheometer and AFM respectively, showed that the material has the typical characteristics of hydrogel, including a three‐dimensional configuration of molecules arranged in a regular network with many discrete caveolae where most of the water is captured. Hydrogel biocompatibility was found to be high for both cell lines, with some differences. Cell viability decreased more in 3T3 cells than Detroit 550 fibroblasts when cultured in the presence of 100 mg/ml hydrogel but not at concentrations of 25 and 50 mg/ml hydrogel. The period of incubation with PAI (24 and 48 h) only partially affected cell viability. Apoptosis, most likely due to cells' inability to adhere to the polymer, was the only type of cell death observed. Fibroblasts grown in the presence of polymer were always metabolically active since they continued to synthesize collagen. In conclusion, PAI hydrogel, even at high concentrations, was biocompatible for both fibroblasts, but in particular for human cells, thus encouraging its use as a dermal filler. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2009
Placenta growth factor, PLGF, influences the motility of lung cancer cells, the role of Rho associated kinase, Rock1
Authors: Chen Jinfeng , Ye Lin , Zhang Lijian , Jiang Wen G.
Published: July 2008

Placenta growth factor (PlGF) is a member of the VEGF family and has been implicated in the aggressive capacity of solid tumours, partly via its impact on angiogenesis. The present study determined the direct biological function of endogenous PlGF in lung cancer cells. From the human non‐small cell lung cancer cell line A549 which expressed good level of PlGF, we created sublines within which PlGF expression was knockdown by way of anti‐PlGF ribozyme transgenes. Remarkable reductions of both PlGF mRNA and protein by the ribozyme transgenes were revealed in A549 transfectants (A549ΔPlGF) using RT‐PCR and Western blotting respectively. A549ΔPlGF cells exhibited significantly reduced migration and adhesion compared with the wild‐type (A549WT) and the empty plasmid control (A549pEF/His) cells. Immunocytochemistry and Western blotting further revealed that the expression of ROCK1, Rho associated kinase, was also reduced in A549ΔPlGF cells, in comparison with wild‐type and control cells. In addition, A549ΔPlGF cells lost its response to a ROCK inhibitor, which otherwise strongly inhibited the motility of A549WT and A549pEF/His cells. These data indicate that PlGF directly regulates the motility of human lung cancer cells and that this regulation critically dependent on ROCK‐1. The study further indicates that PlGF is a potential therapeutic target in lung cancer. J. Cell. Biochem. 105: 313–320, 2008. © 2008 Wiley‐Liss, Inc.
Pregabalin and gabapentin inhibit substance P‐induced NF‐κB activation in neuroblastoma and glioma cells
Authors: Park Seyeon , Ahn Eun Sook , Han Dong Woo , Lee Jong Hwa , Min Kyung Tae , Kim Hyunkyung , Hong Yong‐Woo
Published: July 2008

Pregabalin and gabapentin are lipophilic amino acid derivatives of γ‐amino butyric acid that show anticonvulsant and analgesic activity against neuropathic pain. In this study, we investigated their actions on substance P‐induced NF‐κB activation in human neuroblastoma and rat glioma cells. Pregabalin and gabapentin decreased substance P‐induced NF‐κB activation in these cells. These drugs also inhibited NF‐κB activation in rat spinal dorsal root ganglia cells pre‐treated in vitro with substance P. These results suggest a previously undefined role of pregabalin and gabapentin in the regulation of inflammation‐related intracellular signaling in both neuronal and glial cells. J. Cell. Biochem. 105: 414–423, 2008. © 2008 Wiley‐Liss, Inc.
Modulation of integrin antagonist signaling by ligand binding of the heparin‐binding domain of vitronectin to the αVβ3 integrin
Authors: Maile Laura A. , Aday Ariel W. , Busby Walker H. , Sanghani Ravi , Veluvolu Umadevi , Clemmons David R.
Published: July 2008

The interaction between the arginine glycine and aspartic acid motif (RGD) of integrin ligands such as vitronectin and the integrin receptor αVβ3 in mediating cell attachment has been well described. Similarly, the ability of disintegrins, small RGD containing peptides, to inhibit cell attachment and other cellular processes has also been studied extensively. Recently, we characterized a second site of interaction between vitronectin and its integrin partner. We determined that amino acids within the heparin‐binding domain of vitronectin bind to a cysteine loop (C‐loop) region of β3 and that this interaction is required for the positive effects of αVβ3 ligand occupancy on IGF‐I signaling in smooth muscle cells. In this study we examine the signaling events activated following ligand binding of disintegrins to the αVβ3 and the ability of these signals to be regulated by binding of the heparin‐binding domain of vitronectin. We demonstrate that disintegrin ligand binding activates a series of events including the sequential activation of the tyrosine kinases c‐Src and Syk. This leads to the activation of calpain and the cleavage of the β3 cytoplasmic tail. Addition of vitronectin or a peptide homologous to the heparin‐binding domain inhibited activation of this pathway. Our results suggest that the signaling events that occur following ligand binding to the αVβ3 integrin reflects a balance between the effects mediated through the RGD binding site interaction and the effects mediated by the heparin binding site interaction and that for intact vitronectin the effect of the heparin‐binding domain predominates. J. Cell. Biochem. 105: 437–446, 2008. © 2008 Wiley‐Liss, Inc.
Valproic acid increases expression of methylenetetrahydrofolate reductase (MTHFR) and induces lower teratogenicity in MTHFR deficiency
Authors: Roy Marc , Leclerc Daniel , Wu Qing , Gupta Sapna , Kruger Warren D. , Rozen Rima
Published: July 2008

Valproate (VPA) treatment in pregnancy leads to congenital anomalies, possibly by disrupting folate or homocysteine metabolism. Since methylenetetrahydrofolate reductase (MTHFR) is a key enzyme of folate interconversion and homocysteine metabolism, we addressed the possibility that VPA might have different teratogenicity in Mthfr+/+ and Mthfr+/− mice and that VPA might interfere with folate metabolism through MTHFR modulation. Mthfr+/+ and Mthfr+/− pregnant mice were injected with VPA on gestational day 8.5; resorption rates and occurrence of neural tube defects (NTDs) were examined on gestational day 14.5. We also examined the effects of VPA on MTHFR expression in HepG2 cells and on MTHFR activity and homocysteine levels in mice. Mthfr+/+ mice had increased resorption rates (36%) after VPA treatment, compared to saline treatment (10%), whereas resorption rates were similar in Mthfr+/− mice with the two treatments (25–27%). NTDs were only observed in one group (VPA‐treated Mthfr+/+). In HepG2 cells, VPA increased MTHFR promoter activity and MTHFR mRNA and protein (2.5‐ and 3.7‐fold, respectively). Consistent with cellular MTHFR upregulation by VPA, brain MTHFR enzyme activity was increased and plasma homocysteine was decreased in VPA‐treated pregnant mice compared to saline‐treated animals. These results underscore the importance of folate interconversion in VPA‐induced teratogenicity, since VPA increases MTHFR expression and has lower teratogenic potential in MTHFR deficiency. J. Cell. Biochem. 105: 467–476, 2008. © 2008 Wiley‐Liss, Inc.
Single‐molecule analysis of chromatin: Changing the view of genomes one molecule at a time
Authors: Pondugula Santhi , Kladde Michael P.
Published: July 2008

Wrapping DNA into chromatin provides a wealth of regulatory mechanisms that ensure normal growth and development in eukaryotes. Our understanding of chromatin structure, including nucleosomes and non‐histone protein–DNA interactions, has benefited immensely from nuclease and chemical digestion techniques. DNA‐bound proteins, such as histones or site‐specific factors, protect DNA against nuclease cleavage and generate large nucleosomal or small regulatory factor footprints. Chromatin subject to distinct modes of regulation often coincides with sites of nuclease hypersensitivity or nucleosome positioning. An inherent limitation of cleavage‐based analyses has been the inability to reliably analyze regions of interest when levels of digestion depart from single‐hit kinetics. Moreover, cleavage‐based techniques provide views that are averaged over all the molecules in a sample population. Therefore, in cases of occupancy of multiple regulatory elements by factors, one cannot define whether the factors are bound to the same or different molecules in the population. The recent development of DNA methyltransferase‐based, single‐molecule MAP‐IT technology overcomes limitations of ensemble approaches and has opened numerous new avenues in chromatin research. Here, we review the strengths, limitations, applications and future prospects of MAP‐IT ranging from structural issues to mechanistic questions in eukaryotic chromatin regulation. J. Cell. Biochem. 105: 330–337, 2008. © 2008 Wiley‐Liss, Inc.
Molecular mechanics models for tetracycline analogs
Authors: Aleksandrov Alexey , Simonson Thomas
Published: July 2008

Tetracyclines (Tcs) are an important family of antibiotics that bind to the ribosome and several proteins. To model Tc interactions with protein and RNA, we have developed a molecular mechanics force field for 12 tetracyclines, consistent with the CHARMM force field. We considered each Tc variant in its zwitterionic tautomer, with and without a bound Mg2+. We used structures from the Cambridge Crystallographic Data Base to identify the conformations likely to be present in solution and in biomolecular complexes. A conformational search by simulated annealing was undertaken, using the MM3 force field, for tetracycline, anhydrotetracycline, doxycycline, and tigecycline. Resulting, low‐energy structures were optimized with an ab initio method. We found that Tc and its analogs all adopt an extended conformation in the zwitterionic tautomer and a twisted one in the neutral tautomer, and the zwitterionic‐extended state is the most stable in solution. Intermolecular force field parameters were derived from a standard supermolecule approach: we considered the ab initio energies and geometries of a water molecule interacting with each Tc analog at several different positions. The final, rms deviation between the ab initio and force field energies, averaged over all forms, was 0.35 kcal/mol. Intramolecular parameters were adopted from either the standard CHARMM force field, the ab initio structure, or the earlier, plain Tc force field. The model reproduces the ab initio geometry and flexibility of each Tc. As tests, we describe MD and free energy simulations of a solvated complex between three Tcs and the Tet repressor protein. © 2008 Wiley Periodicals, Inc. J Comput Chem, 2009
Quantum chemistry in parallel with PQS
Authors: Baker Jon , Wolinski Krzysztof , Malagoli Massimo , Kinghorn Don , Wolinski Pawel , Magyarfalvi Gábor , Saebo Svein , Janowski Tomasz , Pulay Peter
Published: July 2008

This article describes the capabilities and performance of the latest release (version 4.0) of the Parallel Quantum Solutions (PQS) ab initio program package. The program was first released in 1998 and evolved from the TEXAS program package developed by Pulay and coworkers in the late 1970s. PQS was designed from the start to run on Linux‐based clusters (which at the time were just becoming popular) with all major functionality being (a) fully parallel; and (b) capable of carrying out calculations on large—by ab initio standards—molecules, our initial aim being at least 100 atoms and 1000 basis functions with only modest memory requirements. With modern hardware and recent algorithmic developments, full accuracy, high‐level calculations (DFT, MP2, CI, and Coupled‐Cluster) can be performed on systems with up to several thousand basis functions on small (4‐32 node) Linux clusters. We have also developed a graphical user interface with a model builder, job input preparation, parallel job submission, and post‐job visualization and display. © 2008 Wiley Periodicals, Inc. J Comput Chem, 2009
Cognitive–behavioral conjoint therapy for posttraumatic stress disorder: application to operation enduring and Iraqi Freedom veterans
Authors: Monson Candice M. , Fredman Steffany J. , Adair Kathryn C.
Published: July 2008

As the newest generation of veterans returns home from their duties abroad, many face the individual and interpersonal aftereffects of duty‐related traumatic experiences. Despite the established association between posttraumatic stress disorder (PTSD) and relationship problems, there is a lack of evidence‐based conjoint treatments that target both PTSD and relationship distress. Cognitive–behavioral conjoint therapy (CBCT) for PTSD was developed to address this need. The authors summarize knowledge on the association between PTSD and relationship functioning, as well as recent research on veterans and their partners. Following an overview of CBCT for PTSD, the authors present a case study to illustrate the application of CBCT to an Operation Enduring and Iraqi Freedom couple. © 2008 Wiley Periodicals, Inc. J Clin Psychol: In Session 64:1‐14, 2008.
Age‐related differences in insulin‐like growth factor‐1 receptor signaling regulates Akt/FOXO3a and ERK/Fos pathways in vascular smooth muscle cells
Authors: Li Muyao , Chiu Jen‐Fu , Gagne Jessica , Fukagawa Naomi K.
Published: July 2008

Advanced age is a major risk factor for atherosclerosis, but how aging per se influences pathogenesis is not clear. Insulin‐like growth factor‐1 receptor (IGF‐1R) promotes aortic vascular smooth muscle cell (VSMC) growth, migration, and extracellular matrix formation, but how IGF‐1R signaling changes with age in VSMC is not known. We previously found age‐related differences in the activation of Akt/FOXO3a and ERK1/2 pathways in VSMC, but the upstream signaling remains unclear. Using explanted VSMC from Fischer 344/Brown Norway F1 hybrid rats shown to display age‐related vascular pathology similar to humans, we compared IGF‐1R expression in early passages of VSMC and found a constitutive activation of IGF‐1R in VSMC from old compared to young rats, including IGF‐1R expression and its tyrosine kinase activity. The link between IGF‐1R activation and the Akt/FOXO3a and ERK pathways was confirmed through the induction of IGF‐1R with IGF‐1 in young cells and attenuation of IGF‐1R with an inhibitor in old cells. The effects of three kinase inhibitors: AG1024, LY294002, and TCN, were compared in VSMC from old rats to differentiate IGF‐1R from other upstream signaling that could also regulate the Akt/FOXO and ERK pathways. Genes for p27kip‐1, catalase and MnSOD, which play important roles in the control of cell cycle arrest and stress resistance, were found to be FOXO3a‐targets based on FOXO3a‐siRNA treatment. Furthermore, IGF‐1R signaling modulated these genes through activation of the Akt/FOXO3a pathway. Therefore, activation of IGF‐1R signaling influences VSMC function in old rats and may contribute to the increased risk for atherosclerosis. J. Cell. Physiol. 217: 377–387, 2008. © 2008 Wiley‐Liss, Inc.
15‐deoxy‐delta 12,14‐prostaglandin J2 inhibits the synthesis of the acute phase protein SIP24 in cartilage: Involvement of COX‐2 in resolution of inflammation
Authors: Ulivi Valentina , Cancedda Ranieri , Cancedda Fiorella Descalzi
Published: July 2008

We previously demonstrated that, in the MC615 cartilage cell line, the p38/NF‐kB pathway is activated both during differentiation and in response to an inflammatory stimulus. In both cases, the p38/NF‐kB pathway activation leads to the expression of the lipocalin SIP24 and of COX‐2. Given the fact that, in the same cells, the COX‐2 expression is sustained during the inflammation resolution, at the same time that the SIP24 expression is suppressed, in the present study we tested the hypothesis that COX‐2 products play a role in SIP24 repression. Taken together, our results suggest that, during the resolution of inflammation, COX‐2 represses the acute phase protein SIP24 and restores physiological conditions, possibly through a pathway involving PPARγ. Experimental evidences being the following: (1) 15‐deoxy‐delta 12,14‐prostaglandin J2, but not PGE2: (i) inhibits the expression of SIP24 in the inflammatory phase and induces COX‐2 synthesis; (ii) represses NF‐kB activation induced by LPS; (iii) represses the synthesis of microsomal PGE Synthase‐1 induced by LPS. (2) PPARγ and PPARα are present in MC615 cells in both proliferating and hyperconfluent cultures. (3) PPARγ ligand GW7845, but not PPARα ligand GW7647: (i) represses the expression of SIP24 induced by LPS; (ii) induces COX‐2 expression. (4) p38 is involved in the PPARγ mediated induction of COX‐2. In fact 15‐deoxy‐delta 12,14‐prostaglandin J2 activates p38 and the cell pretreatment with the p38 specific inhibitor SB203580 represses the expression of COX‐2 induced by both the 15‐deoxy‐delta12,14‐prostaglandin J2 and the PPARγ ligand GW7845. J. Cell. Physiol. 217: 433–441, 2008. © 2008 Wiley‐Liss, Inc.
The mesenchymal stromal cell contribution to homeostasis
Authors: Valtieri Mauro , Sorrentino Antonio
Published: July 2008

Adult mesenchymal stromal cells (MSCs) are undifferentiated multi‐potent cells predominantly residing in the bone marrow (BM), but also present with similar but not identical features in many other tissues such as blood, placenta, dental pulp, and adipose tissue. MSCs have the potential to differentiate into multiple skeletal phenotypes like osteoblasts, chondrocytes, adipocytes, stromal cells, fibroblasts, and possibly tendons. MSCs differentiation potential, ex vivo expansion capacity, nurturing and immunomodulatory proficiencies oriented these versatile cells in several areas of ongoing clinical applications. However, the absence of MSC‐specific markers for isolation and characterization together with the lack of a comprehensive view of the molecular pathways governing their particular biological properties, remains a primary obstacle to their research and application. In this review we discuss some areas of growing interest in MSCs biology: their contribution to the hematopoietic stem cell (HSC) niche, to regenerative medicine, their role in cancer and in therapy as delivery tools and their micro‐RNA (miRNA) signatures. Despite rapid progress in the MSC field, it is generally thought that only a fraction of their full potential has been realized thus far. J. Cell. Physiol. 217: 296–300, 2008. © 2008 Wiley‐Liss, Inc.
Mitotic catastrophe and apoptosis induced by docetaxel in hormone‐refractory prostate cancer cells
Authors: Fabbri Francesco , Amadori Dino , Carloni Silvia , Brigliadori Giovanni , Tesei Anna , Ulivi Paola , Rosetti Marco , Vannini Ivan , Arienti Chiara , Zoli Wainer , Silvestrini Rosella
Published: July 2008

Studies performed in different experimental and clinical settings have shown that Docetaxel (Doc) is effective in a wide range of tumors and that it exerts its activity through multiple mechanisms of action. However, the sequence of events induced by Doc which leads to cell death is still not fully understood. Moreover, it is not completely clear how Doc induces mitotic catastrophe and whether this process is an end event or followed by apoptosis or necrosis. We investigated the mechanisms by which Doc triggers cell death in hormone‐refractory prostate cancer cells by analyzing cell cycle perturbations, apoptosis‐related marker expression, and morphologic cell alterations. Doc induced a transient increase in G2/M phase followed by the appearance of G0/1 hypo‐ and hyperdiploid cells and increased p21 expression. Time‐ and concentration‐dependent apoptosis was induced in up to 70% of cells, in concomitance with Bcl‐2 phosphorylation, which was followed by caspase‐2 and ‐3 activation. In conclusion, Doc would seem to trigger apoptosis in hormone‐refractory prostate cancer cells via mitotic catastrophe through two forms of mitotic exit, in concomitance with increased p21 expression and caspase‐2 activation. J. Cell. Physiol. 217: 494–501, 2008. © 2008 Wiley‐Liss, Inc.
Low‐power laser irradiation activates Src tyrosine kinase through reactive oxygen species‐mediated signaling pathway
Authors: Zhang Juntao , Xing Da , Gao Xuejuan
Published: July 2008

Low‐power laser therapy in medicine is widespread but the mechanisms are not fully understood. It has been suggested that low‐power laser irradiation (LPLI) could induce photochemical reaction and activate several intracellular signaling pathways. Reactive oxygen species (ROS) are considered to be the key secondary messengers produced by LPLI. Here, we studied the signaling pathway mediated by ROS upon the stimulation of LPLI. Src tyrosine kinases are well‐known targets of ROS and can be activated by oxidative events. Using a Src reporter based on fluorescence resonance energy transfer (FRET) and confocal laser scanning microscope, we visualized the dynamic Src activation in Hela cells immediately after LPLI. Moreover, Src activation by LPLI was in a dose‐dependent manner. The increase of Src phosphorylation at Tyr416 was detected by Western blotting. In the presence of vitamin C, catalase alone, or the combination of catalase and superoxide dismutase (SOD), the activation of Src by LPLI is significantly abolished. In contrast, Gö6983 loading, a PKC inhibitor, did not affect this response. Treatment of Hela cells with exogenous H2O2 also resulted in a concentration‐dependent activation of Src. These results demonstrated that it was ROS that mediated Src activation by LPLI. Cellular viability assay revealed that laser irradiation of low doses (≤25 J/cm2) promoted Hela cells viability while high doses impaired. Therefore, LPLI induces ROS‐mediated Src activation which may play an important role in biostimulatory effect of LPLI. J. Cell. Physiol. 217: 518–528, 2008. © 2008 Wiley‐Liss, Inc.
S10 phosphorylation of p27 mediates atRA induced growth arrest in ovarian carcinoma cell lines
Authors: Radu Maria , Soprano Dianne R. , Soprano Kenneth J.
Published: July 2008

All trans retinoic acid (atRA) has been shown to inhibit the growth of CAOV3 ovarian carcinoma cells and to elevate the level of p27 cyclin‐dependent kinase inhibitor. We report here that phosphorylation at S10 residue is an important event in mediating p27 role in atRA induced growth arrest. atRA treatment of atRA sensitive CAOV3 cells increases the levels of S10 phospho‐p27 in both nuclear and cytoplasmic cell compartments. This increase is accompanied by a decrease in the levels of skp2 protein. This effect was not observed in SKOV3 cells which are resistant to atRA growth inhibitory effect. An A10‐p27 mutant that cannot be phosphorylated at S10 induces a dominant negative effect on the atRA effect on the levels and activity of endogenous p27. Overexpression of A10‐p27 mutant renders CAOV3 cells more resistant to atRA treatment and reverses the effect that atRA has on p27 binding to CDKs, on CDK activity, and on the expression of S phase genes. J. Cell. Physiol. 217: 558–568, 2008. © 2008 Wiley‐Liss, Inc.
Extraction and separation of molybdenum(VI) from acidic media by fatty hydrazides
Authors: Mohamad Sharifah , Wan Yunus Wan Md Zin , Haron Md Jelas , Abdul Rahman Mohd Zaki
Published: July 2008

BACKGROUND: The increasing demand for molybdenum has encouraged the development of low‐cost and environmentally friendly extractants to recycle and recover this metal. In the present study, solvent extraction of Mo(VI) from acidic media using a mixture of fatty hydrazides synthesised from palm olein as the extractant was carried out. The effects of various parameters such as acid, diluent, contact time, extractant concentration, metal ion concentration and stripping agent and the separation of Mo(VI) from other metal ions such as Co(II), Ni(II), Al(III) and Mn(II) were investigated.

RESULTS: It was found that the extraction of Mo(VI) into the organic phase involved the formation of 1:3 complexes. Mo(VI) was successfully separated from commonly associated metal ions such as Ni(II), Co(II), Al(III) and Mn(II). Mo(VI) stripping from the loaded organic phase was studied using different acidic and alkaline solutions and was found to be optimal with ammonium hydroxide solution.

CONCLUSION: These results are useful for the development of a method to recover Mo(VI) from acidic media utilising fatty hydrazides as the extractant. Copyright © 2008 Society of Chemical Industry
Detection of microembolic signals using power M‐mode Doppler sonography in acute stroke patients with intracranial artery stenosis
Authors: Tan Teng‐Yeow , Chen Ting‐Yao
Published: July 2008

Purpose.

Microembolic signals (MES) can be detected in a variety of clinical situations using conventional transcranial Doppler (TCD) sonography. We studied the prevalence of positive MESs in acute stroke patients with intracranial artery stenosis using power M‐mode Doppler (PMD) sonography and also tested the feasibility of this new technique.

Method.

Thirty‐three consecutive acute ischemic stroke or transient ischemic attack patients with intracranial large artery occlusive disease were enrolled. PMD/TCD monitoring for 30 minutes was used for MES detection downstream of the stenotic artery within 1 week after stroke onset. Clinical risk factors in emboli‐positive and emboli‐negative patients were assessed.

Results.

MESs were detected in 21% (7/33) of patients. No significant differences were found in clinical risk factors between emboli‐positive and emboli‐negative patients.

Conclusion.

PMD sonography to detect MESs in acute stroke patients is feasible and may be used in future clinical trials regarding MES detection. © 2008 Wiley Periodicals, Inc. J Clin Ultrasound, 2008
Retrieval of absorptive potential variation in electron beam sensitive specimens using a single energy‐filtered bright‐field TEM image
Authors: Bhattacharyya Somnath , Jinschek Joerg R.
Published: July 2008

A method is presented for retrieving the variation of the absorptive potential in electron beam sensitive soft material. The absorptive potential is directly related to the variations in atomic density and in chemical composition fluctuation. In our approach only a single zero‐loss energy‐filtered bright‐field transmission electron microscopy (TEM) image is sufficient to obtain this information. The accuracy and the effectiveness of this proposed method has been tested using both simulation and experiment. As an experimental example of soft (organic) material, the variation in absorptive potential in an unstained tissue sample of zebrafish gill has been determined. Microsc. Res. Tech., 2008. © 2008 Wiley‐Liss, Inc.
Image signal‐to‐noise ratio estimation using Shape‐Preserving Piecewise Cubic Hermite Autoregressive Moving Average model
Authors: Sim K.S. , Wee M.Y. , Lim W.K.
Published: July 2008

We propose to cascade the Shape‐Preserving Piecewise Cubic Hermite model with the Autoregressive Moving Average (ARMA) interpolator; we call this technique the Shape‐Preserving Piecewise Cubic Hermite Autoregressive Moving Average (SP2CHARMA) model. In a few test cases involving different images, this model is found to deliver an optimum solution for signal to noise ratio (SNR) estimation problems under different noise environments. The performance of the proposed estimator is compared with two existing methods: the autoregressive‐based and autoregressive moving average estimators. Being more robust with noise, the SP2CHARMA estimator has efficiency that is significantly greater than those of the two methods. Microsc. Res. Tech., 2008. © 2008 Wiley‐Liss, Inc.
Quantification of microvessels in canine lymph nodes
Authors: Tonar Zbyněk , Egger Gunter F. , Witter Kirsti , Wolfesberger Birgitt
Published: July 2008

Quantification of microvessels in tumors is mostly based on counts of vessel profiles in tumor hot spots. Drawbacks of this method include low reproducibility and large interobserver variance, mainly as a result of individual differences in sampling of image fields for analysis. Our aim was to test an unbiased method for quantifying microvessels in healthy and tumorous lymph nodes of dogs. The endothelium of blood vessels was detected in paraffin sections by a combination of immunohistochemistry (von Willebrand factor) and lectin histochemistry (wheat germ agglutinin) in comparison with detection of basal laminae by laminin immunohistochemistry or silver impregnation. Systematic uniform random sampling of 50 image fields was performed during photo‐documentation. An unbiased counting frame (area 113,600 μm2) was applied to each micrograph. The total area sampled from each node was 5.68 mm2. Vessel profiles were counted according to stereological counting rules. Inter‐ and intraobserver variabilities were tested. The application of systematic uniform random sampling was compared with the counting of vessel profiles in hot spots. The unbiased estimate of the number of vessel profiles per unit area ranged from 100.5 ± 44.0/mm2 to 442.6 ± 102.5/mm2 in contrast to 264 ± 72.2/mm2 to 771.0 ± 108.2/mm2 in hot spots. The advantage of using systematic uniform random sampling is its reproducibility, with reasonable interobserver and low intraobserver variance. This method also allows for the possibility of using archival material, because staining quality is not limiting as it is for image analysis, and artifacts can easily be excluded. However, this method is comparatively time‐consuming. Microsc. Res. Tech., 2008. © 2008 Wiley‐Liss, Inc.
The acute temperature tolerance of green sturgeon (Acipenser medirostris) and the effect of environmental salinity
Authors: Sardella Brian A. , Sanmarti Enio , Kültz Dietmar
Published: July 2008

We investigated the effect of environmental salinity on the upper thermal tolerance of green sturgeon (Acipenser medirostris), a threatened species whose natural habitat is vulnerable to temperature and salinity variation as a result of global climate change. Freshwater (FW)‐reared sturgeon were gradually acclimated to salinities representing FW, estuary water (EST), or San Francisco Bay water (BAY) at 18°C, and their critical thermal maximum (CTMax) was measured by increasing temperature 0.3°C/min until branchial ventilation ceased. CTMax was 34.2±0.09°C in EST‐acclimated fish, with FW‐ and BAY‐acclimated fish CTMax at 33.7±0.08 and 33.7±0.1°C, respectively. Despite the higher CTMax in EST‐acclimated fish, FW‐acclimated sturgeon ventilation rate reached a peak that was 2°C higher than EST‐ and BAY‐acclimated groups and had a greater range of temperatures within which they exhibited normal ventilatory function as assessed by Q10 calculation. The osmoregulatory consequences of exposure to near‐lethal temperatures were assessed by measuring plasma osmolality and hematocrit, as well as white muscle, brain, and heart tissue water contents. Hematocrit was increased following CTMax exposure, most likely owing to the elevated metabolic demands of temperature increase, and plasma osmolality was significantly increased in EST‐ and BAY‐acclimated fish, which was likely the result of a greater osmotic gradient across the gill as metabolism increased. To our knowledge, this represents the first evidence for an effect of salinity on the upper thermal tolerance of sturgeon, as well as the first investigation of the osmoregulatory consequences of exposure to near‐lethal temperatures. J. Exp. Zool. 309A:477–483, 2008. © 2008 Wiley‐Liss, Inc.
Urea production capacity in the wood frog (Rana sylvatica) varies with season and experimentally induced hyperuremia
Authors: Schiller Tamar M. , Costanzo Jon P. , Lee Richard E.
Published: July 2008

Wood frogs (Rana sylvatica) can accumulate substantial amounts of urea during fall and winter. In this study, maximal urea production capacity was examined in R. sylvatica collected at various times of the year and in response to experimental hyperuremia and dehydration. Activity and expression of carbamoyl phosphate synthetase I (CPS I), the hepatic regulatory enzyme of the urea cycle, were used as indicators of urea production capacity. The high levels of CPS I activity in summer frogs were maintained through much of winter, a time when many metabolic processes are downregulated, suggesting that urea production is important during hibernation. In laboratory experiments, hyperuremia in fully hydrated frogs caused CPS I activity to decrease by ∼41%, suggesting that urea functions as a feedback inhibitor. In contrast, CPS I activity was maintained in hyperuremic, dehydrated frogs. The significance of this response is unclear, although perhaps urea functions to counteract inhibitory effects of concentrated salts. Generally, changes in CPS I activity were not reflected by corresponding changes in CPS I quantity, indicating that this enzyme is not primarily regulated through transcription and translation; rather, control may be achieved by posttranslational modifications and/or feedback inhibition. Our findings suggest that maintenance of urea production capacity in hibernating R. sylvatica facilitates accumulation of this osmolyte, which has important roles in the winter biology of this species. J. Exp. Zool. 309A:484–493, 2008. © 2008 Wiley‐Liss, Inc.
RNA interfering connective tissue growth factor prevents rat hepatic stellate cell activation and extracellular matrix production
Authors: Li Guangming , Li Dingguo , Xie Qing , Shi Yi , Jiang Shan , Jin Youxin
Published: July 2008

Background

Connective tissue growth factor (CTGF) is a possible key determinant of progressive fibrosis. Small interfering RNA (siRNA) is a powerful tool for silencing gene expression post‐transcriptionally. Therefore, the present study aimed to determine whether synthetic siRNA target CTGF down‐regulates the expression of the CTGF gene in primary rat hepatic stellate cells (HSC) and HSC T6, and, furthermore, whether it prevents rat HSC activation and extracelluar matrix (ECM) production.

Methods

Primary HSC were obtained by enzymatic perfusion of rat liver. HSC T6, primary HSC were treated with siRNAs that target CTGF or a control siRNA by addition to the culture medium.

Results

We obtained one siRNA that could sequence‐specifically reduce target gene expression by over 90% at a concentration of 200 nM in the cell culture medium for a total of three siRNAs targeting CTGF genes. In HSC T6 cells, the effect of CTGF siRNA was dose‐dependent (50–200 nM) and time‐limited to a 24–72‐h period. The siRNA knockdown of CTGF significantly reduced the expression of α‐smooth muscle actin protein, increased the number of cells, upregulated the ratios of G0/G1 stage in rat HSC at 7 days of culture after plating, and attenuated the expression of type I and III collagen mRNA with a supernatant concentration of hyaluronic acid, and type III procollagen in an activated HSC of culture for 24–72 h.

Conclusions

CTGF siRNA could effectively and sequence‐specifically down‐regulate the expression of CTGF in rat HSC, resulting in significant inhibition of HSC activation and proliferation as well as ECM production. These findings indicate that synthetic siRNA targeting CTGF could prove to be a useful treatment of liver fibrosis. Copyright © 2008 John Wiley & Sons, Ltd.
Mitigation of radiation‐induced skin injury by AAV2‐mediated MnSOD gene therapy
Authors: Yan Shiqing , Brown Stephen L. , Kolozsvary Andrew , Freytag Svend O. , Lu Mei , Kim Jae Ho
Published: July 2008

Background

Radiation‐induced, long‐lived free radicals, reactive oxygen species and pro‐inflammatory cytokines have been implicated in the resultant tissue injury after exposure to ionizing radiation.

Methods

An approach designed to reduce the damaging effects of reactive oxidants employs metalloenzymes of superoxide dismutase (SOD), such as MnSOD. Recombinant adeno‐associated virus 2 (AAV2) provides safe and long‐term expression in humans. We tested the effectiveness of AAV2‐MnSOD‐hrGFP, a vector expressing MnSOD and green fluorescent protein (GFP) in preclinical models.

Results

Infection of cultured cells with AAV2‐MnSOD‐hrGFP showed enhanced expression of MnSOD and GFP. Sustained expression of GFP was achieved for at least 1 month in vivo following administration of AAV2‐MnSOD‐hrGFP to subcutaneous tissue of C57BL/6J mice. A single subcutaneous injection of AAV2‐MnSOD‐hrGFP significantly mitigated acute skin injury following single dose of irradiation of either 30 or 35 Gy.

Conclusions

The proof‐of‐concept demonstrated in the present study together with the known safety profile in humans indicate that AAV‐mediated MnSOD expression has potential countermeasure utility against normal tissue injury following radiation therapy or radiological accident. Copyright © 2008 John Wiley & Sons, Ltd.
Adenovirus‐mediated inhibition of SPARC attenuates liver fibrosis in rats
Authors: Camino Alejandra M. , Atorrasagasti Catalina , Maccio Daniela , Prada Federico , Salvatierra Edgardo , Rizzo Miguel , Alaniz Laura , Aquino Jorge B. , Podhajcer Osvaldo. L. , Silva Marcelo , Mazzolini Guillermo
Published: July 2008

Background

The interaction between fibrogenic cells and extracellular matrix plays a role in liver fibrosis, yet the mechanisms are largely unknown. Secreted protein, acidic and rich in cysteine (SPARC) is a matricellular glycoprotein that is expressed by hepatic stellate cells and is overexpressed in fibrotic livers. We investigated the in vivo role of SPARC in experimentally induced liver fibrosis in rats.

Methods

A recombinant adenovirus carrying antisense SPARC was constructed (AdasSPARC). Advanced liver fibrosis was induced in Sprague‐Dawley rats by prolonged intraperitoneal administration of thioacetamide. Animals received injections of AdasSPARC or Adβgal (control adenovirus) via the tail vein and directly into the liver 1 week after the first dose. The pathological changes in liver tissues and indices of fibrosis were assessed at eight weeks. Expression of SPARC, transforming growth factor (TGF)‐β and α‐smooth muscle actin were evaluated by quantitative real‐time polymerase chain reaction, western blotting, enzyme‐linked immunosorbent assay and immunohistochemistry.

Results

Hepatic SPARC expression significantly increased during the development of liver fibrosis. AdasSPARC markedly attenuated the development of hepatic fibrosis in rats treated with thiocetamide, as assessed by decreased collagen deposition, lower hepatic content of hydroxyproline and less advanced morphometric stage of fibrosis. AdasSPARC treatment reduced inflammatory activity (Knodell score) and suppressed transdifferentiation of hepatic stellate cell to the myofibroblasts like phenotype in vivo. Furthermore, in vitro inhibition of SPARC on hepatic stellate cells decreases the production of TGF‐β.

Conclusions

This is the first study to demonstrate that knockdown of hepatic SPARC expression ameliorates thioacetamide‐induced liver fibrosis in rats with chronic liver injury. SPARC is a potential target for gene therapy in liver fibrosis. Copyright © 2008 John Wiley & Sons, Ltd.
Effect of peptides bearing nuclear localization signals on therapeutic ultrasound mediated gene delivery
Authors: Duvshani‐Eshet Maayan , Keren Hadas , Oz Shira , Radzishevsky Inna S. , Mor Amram , Machluf Marcelle
Published: July 2008

Background

One of the major limitations of nonviral gene delivery methods is nuclear transport of plasmid DNA (pDNA). Peptides bearing nuclear localization signal (NLS) were shown to mediate nuclear import of macromolecules. We have explored the use of cell‐permeable peptides (CPP) bearing NLS sequences to enhance transfection mediated by a nonviral approach: therapeutic ultrasound (TUS).

Methods

Two CPP‐NLS peptides which differ in the location of the NLS relative to the CPP were used: S413‐PV and PV‐S413. The peptides were attached to pDNA using electrostatic interactions. Gel‐electrophoresis and fluorescent assays were performed to evaluate pDNA–peptide interactions and condensation effects. Confocal microscopy was used to evaluate pDNA–peptide interaction inside cells. Transfection studies were conducted with the luciferase gene, using pDNA‐peptides alone, or with the application of TUS.

Results

Attachment of both peptides to pDNA condensed the pDNA, with higher affinity for the S413‐PV peptide. This interaction protected pDNA from endonucleases, but was also reversible. Both peptides mediated pDNA delivery to cell cytoplasm, but less significantly to the nucleus. Thus, both peptides produced transfection in cells, when added after incubation with DNA, with higher transfection‐level for PV‐S413. Application of TUS increased transfection mediated by these peptides, but was not higher compared to transfection using TUS and pDNA alone.

Conclusions

This study suggests that CPP‐NLS peptides may be used for condensing pDNA and bringing it into the cell cytoplasm, but their ability to mediate nuclear import of pDNA is insignificant. Copyright © 2008 John Wiley & Sons, Ltd.
Can macroeconomic policy stimulate private investment in South Africa? New insights from aggregate and manufacturing sector‐level evidence
Authors: Ndikumana Leonce
Published: July 2008

This study explores the determinants of investment using both aggregated industry‐level data and disaggretated data on 27 sub‐sectors of the manufacturing sector for the period 1970–2001. According to the results in this study, the government has potentially powerful means at its disposal to stimulate private investment. In particular, a domestic demand stimulus and public investment expansion will produce large gains in private investment. While the direct effects of lowering the interest rate appear to be quantitatively small, indirect effects operating notably through domestic demand and cheaper credit are likely to be large. The evidence in this study also indicates that it is important to minimise exchange rate instability to encourage investment. Copyright © 2008 John Wiley & Sons, Ltd.
A new chemical method of synthesis of modified nucleoside [32P]phosphates
Authors: Yanvarev D. V. , Shirokova E. A. , Kukhanova M. K. , Skoblov Yu. S.
Published: July 2008

A simple method of chemical phosphorylation for modified nucleosides with [32P]orthophosphoric acid in the presence of BrCN is described. The yields of 5′‐[32P]nucleoside monophosphates achieved are 50–65% at nominal specific radioactivities of ca. 1000 Ci/mmol. The mechanism of phosphorylation in the presence of heterocyclic amines is studied. Copyright © 2008 John Wiley & Sons, Ltd.
Sensitivity of redox reactions of dyes to variations of conditions created in mass spectrometric experiments
Authors: Kosevich Marina V. , Chagovets Vitalij V. , Shmigol Irina V. , Snegir Sergej V. , Boryak Oleg A. , Orlov Vadim V. , Shelkovsky Vadim S. , Pokrovskiy Valerij A. , Gomory Agnes
Published: July 2008

Redox behaviour of four imidazophenazine dye derivatives under mass spectrometric conditions of matrix‐assisted laser desorption/ionization (MALDI), laser desorption/ionization (LDI) from metal and graphite surface, electrospray, low temperature secondary ion mass spectrometry (LT SIMS) and fast atom bombardment (FAB) was studied and distinctions in the reduction‐dependent spectral patterns were analyzed from the point of view of different quantities of protons and electrons available for reduction in different techniques. The reduction products [M + 2H]+•, [M + 3H]+ and M−•, [M + H]− were observed in the positive and negative ion modes, respectively, which permitted to suggest independent occurrence of reduction and protonation/deprotonation processes. LDI from graphite substrate was the only technique that allowed us to obtain abundant negative ions of all dye derivatives. The yield of field ionization (FI) or field desorption (FD) mechanism to ion formation under LDI from rough graphite surface has been addressed. The sensitivity of reduction of the dyes to variation of reduction‐initiating agents confirms high redox activity of the dyes essential for their functioning in natural and artificial systems. Copyright © 2008 John Wiley & Sons, Ltd.
Targeted identification of phosphorylated peptides by off‐line HPLC–MALDI‐MS/MS using LC retention time prediction
Authors: Chen Vincent C. , Chou Chi‐Chi , Hsieh Hsin‐Yu , Perreault Hélène , Khoo Kay‐Hooi
Published: July 2008

Protein phosphorylation is a type of posttranslational modification which plays an important role in cell regulation and signal transduction. Because of its biological relevance, a considerable amount of interest has been paid to the development of efficient techniques for phosphopeptide analysis. Although advances in MS control have enabled the high‐throughput discovery of proteins from limited amounts of sample, automated selection of MS/MS precursor ions based on intensity alone can significantly hamper the detection of low‐abundance phosphopeptides. On the basis of the observation that the introduction of a phosphate moiety does not dramatically change peptide retention time in reverse‐phase chromatography, phosphopeptide specific MS/MS fragmentation attempts based on LC retention time and m/z were evaluated using a standard protein mixture, then using in vitro phosphorylated myelin basic protein. Results indicated that the majority (98%) of phosphopeptides identified eluted within a ± 4‐min window of the predicted LC elution time. While studies presented here are primarily proof of concept in nature, data suggest that the use of LC retention time prediction could be a valuable constraint for the identification of phosphopeptides within a set of off‐line LC deposited sample spots. It is expected that the development of these methods will not only permit the targeted identification of protein phosphorylation sites but also allow the in‐depth analysis of the dynamic events linked to the posttranslational modification. Copyright © 2008 John Wiley & Sons, Ltd.