bluuebunny/crossref_metadata_2025_split huggingface dataset:
In vivo growth inhibition of sarcoma 180 by piperlonguminine, an alkaloid amide from the Piper species
Authors: Bezerra Daniel P. , Pessoa Cláudia , Moraes Manoel Odorico de , Alencar Nylane M. N. de , Mesquita Rodney O. , Lima Michael W. , Alves Ana Paula N. N. , Pessoa Otília Deusdênia L. , Chaves João Henrique , Silveira Edilberto R. , Costa‐Lotufo Letícia V. 
Published: November 2007

AbstractMany authors have already emphasized that phytochemicals from spices have biological applications. Piperlonguminine is a known alkaloid amide from peppers, including Piper divaricatum. The aim of this study was to investigate the in vitro and in vivo antitumor effects of piperlonguminine in experimental models. In order to evaluate the toxicological aspects related to piperlonguminine treatment, hematological, biochemical, histopathological and morphological analyses of treated animals were performed. Piperlonguminine did not show any significant in vitro cytotoxic effect at experimental exposure levels, but showed an in vivo antitumor effect. After 7 days of treatment, the inhibition rates were 38.71% and 40.68% at doses of 25 mg kg−1 and 50 mg kg−1, respectively. The histopathological analysis suggests that the liver and kidney were only weakly affected by piperlonguminine treatment. Neither the enzymatic activity of transaminases (AST and ALT) nor the urea levels were significantly altered. In the hematological analysis, all parameters analysed remained constant after piperlonguminine treatment. In conclusion, these data reinforce the anticancer potential of spice components. Copyright © 2007 John Wiley & Sons, Ltd.
Structure–activity relationships for thiol reactivity and rat or human hepatocyte toxicity induced by substituted p‐benzoquinone compounds
Authors: Chan Katie , Jensen Neil , O'Brien Peter J. 
Published: November 2007

AbstractCovalent binding of toxic chemicals to cellular targets is a molecular interaction that initiates a wide array of adverse biological effects. The creation of a covalent bond can be cited as a key initiating step along many toxicity pathways which must be predicted in order to predict the potential of a chemical to cause specific harmful effects. Currently, quantitative structure‐activity relationship (QSAR) models are being improved by focusing on endpoints such as simple electrophile reactivity for covalent interactions rather than on commonly used complex toxicity endpoints. The cytotoxicity and electrophilic reactivity of 10 p‐substituted benzoquinone derivatives, which are well known electrophilic alkylating agents, were investigated under the premise that QSAR toxicity models can be improved when the molecular triggering event is considered. Hepatocyte toxicity was determined by incubation of individual compounds with freshly isolated rat or cryopreserved human hepatocyte suspensions. The potential for chemical reactivity between a chemical and cellular target was measured by determining non‐enzymic reactivity with glutathione, representing thiol nucleophiles. The decline in free thiol moieties was measured to characterize the electrophile reactivity. It was found that the degree of rat hepatotoxicity induced by benzoquinones correlated with the rate at which they non‐enzymically react with glutathione and to various global and atomic electronic frontier orbital parameters which described electrophilicity. Human hepatocytes showed similar results but the statistical significance was much lower. The QSAR expressions suggest that covalent binding reactivity serves as a good correlate to hepatotoxicity and could improve QSAR modeling for potential toxicity risks. Copyright © 2007 John Wiley & Sons, Ltd.
Toxicological evaluation of subchronic exposure to diphenyl diselenide in rats
Authors: Meotti Flavia Carla , Borges Vanessa Corralo , Perottoni Juliano , Nogueira Cristina Wayne 
Published: November 2007

AbstractThe aim of this study was to investigate the effects caused by subchronic exposure to diphenyl diselenide in rats. Adult Wistar rats were exposed to diphenyl diselenide (5–300 µmol kg−1, subcutaneously) once a day for 14 days. The subchronic administration of diphenyl diselenide at a dose of 300 µmol kg−1 significantly increased aspartate aminotransferase (AST) and alanine aminotransferase (ALT) activities in plasma. Conversely, this exposure did not alter lactate dehydrogenase (LDH) activity, urea and creatinine levels in plasma. The activity of δ‐aminolevulinate dehydratase (δ‐ALA‐D) from liver and kidney was inhibited by high dosages of diphenyl diselenide. Diphenyl diselenide did not alter renal Na+/K+ATPase. A decline in body weight gain was associated with a decrease in food consumption in rats treated with 100 or 300 µmol kg−1 diphenyl diselenide. At these dosages (100 and 300 µmol kg−1), diphenyl diselenide did not cause histological alterations in the liver of rats. Taken together, these results demonstrated that subchronic exposure to diphenyl diselenide at high doses induced minor toxicological effects. Copyright © 2007 John Wiley & Sons, Ltd.
Microwave plasma surface modification of silicone elastomer with allylamine for improvement of biocompatibility
Authors: Ren T. B. , Weigel Th. , Groth Th. , Lendlein A. 
Published: November 2007

AbstractThe microwave plasma surface modification of silicone elastomer with allylamine was studied to improve the biocompatibility of the material. An effort was made to clarify the relationships among plasma conditions and surface chemical composition, physical surface properties and biocompatibility of material, as well as the stability of plasma deposited layers. ATR‐IR, XPS, Ellipsometry measurements, and contact angle measurements were used to investigate the changes of surface. The stability of plasma‐treated silicone surfaces were also studied. The results demonstrated that the temperature and pressure had a strong influence on the chemical composition and structure of surface‐deposited layer. The layer was nearly completely crosslinking when the modification was carried out at 60°C. The polymerization speed decreased linearly with temperature. The XPS analysis results showed that the nitrogen element content in the surface layer was very high, especially under low pressure. The nitrogen/carbon ratio in the layer even greatly surpassed that of the allylamine monomer. The wettability of the silicone surface was greatly improved after plasma modification, and increased with the quantities of amine groups. The plasma‐treated surfaces have good storage stability in air up to 3 months. The wettability of the surfaces decreased incipiently and then it dramatically increased with further time. The human skin fibroblasts were used to evaluate biocompatibility of plasma‐treated silicone elastomer. The surface biocompatibility was greatly improved after modification; human skin fibroblasts adhered quickly and grew well on the modified silicone surface. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res 2008
Bisphosphonate coating on titanium screws increases mechanical fixation in rat tibia after two weeks
Authors: Wermelin Karin , Aspenberg Per , Linderbäck Paula , Tengvall Pentti 
Published: November 2007

AbstractRecently published data indicate that immobilized N‐bisphosphonate enhances the pullout force and energy uptake of implanted stainless steel screws at 2 weeks in rat tibia. This study compares titanium screws with and without a bisphosphonate coating in the same animal model. The screws were first coated with an ∼100‐nm thick crosslinked fibrinogen film. Pamidronate was subsequently immobilized into this film via EDC/NHS‐activated carboxyl groups within the fibrinogen matrix, and finally another N‐bisphosphonate, ibandronate, was physically adsorbed. The release kinetics of immobilized 14C‐alendronate was measured in buffer up to 724 h and showed a 60% release within 8 h. Mechanical tests demonstrated a 32% (p = 0.04) and 48% (p = 0.02) larger pullout force and energy until failure after 2 weeks of implantation, compared to uncoated titanium screws. A control study with physically adsorbed pamidronate showed no effect on mechanical fixation, probably due to a too small adsorbed amount. We conclude that the fixation of titanium implants in bone can be improved by fibrinogen matrix‐bound bisphosphonates. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res 2008
Morphology, proliferation, and osteogenic differentiation of mesenchymal stem cells cultured on titanium, tantalum, and chromium surfaces
Authors: Stiehler Maik , Lind Martin , Mygind Tina , Baatrup Anette , Dolatshahi‐Pirouz Alireza , Li Haisheng , Foss Morten , Besenbacher Flemming , Kassem Moustapha , Bünger Cody 
Published: November 2007

AbstractMetallic implants are widely used in orthopedic surgery and dentistry. Durable osseous fixation of an implant requires that osteoprogenitor cells attach and adhere to the implant, proliferate, differentiate into osteoblasts, and produce mineralized matrix. In the present study, we investigated the interactions between human mesenchymal stem cells (MSCs) and smooth surfaces of titanium (Ti), tantalum (Ta), and chromium (Cr). Mean cellular area was quantified using fluorescence microscopy (4 h). Cellular proliferation was assessed by 3H‐thymidine incorporation and methylene blue cell counting assays (4 days). Osteogenic differentiation response was quantified by cell‐specific alkaline phosphatase activity (ALP) assay (4 days), expression analysis of bone‐related genes (4 days), and mineralization assay (21 days). Undifferentiated and osteogenically stimulated MSCs cultured on the different surfaces showed the same tendencies for proliferation and differentiation. MSCs exposed to Ti surfaces demonstrated enhanced proliferation compared with Ta and Cr surfaces. Cultivation of MSCs on Ta surfaces resulted in significantly increased mean cellular area and cell‐specific ALP activity compared with the other surfaces tested. Cells cultured on Cr demonstrated reduced spreading and proliferation. In conclusion, Ta metal, as an alternative for Ti, can be considered as a promising biocompatible material, whereas further studies are needed to fully understand the role of Cr and its alloys in bone implants. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2008
Polymeric scaffolds prepared via thermally induced phase separation: Tuning of structure and morphology
Authors: Pavia F. Carfì , La Carrubba V. , Piccarolo S. , Brucato V. 
Published: November 2007

AbstractScaffolds suitable for tissue engineering applications like dermal reconstruction were prepared by Thermally Induced Phase Separation (TIPS) starting from a ternary solution PLLA/dioxane/water. The experimental protocol consisted of three consecutive steps, a first quench from the homogeneous solution to an appropriate demixing temperature (within the metastable region), a holding stage for a given residence time, and a final quench from the demixing temperature to a low temperature (within the unstable region). A large variety of morphologies, in terms of average pore size and interconnection, were obtained upon modifying the demixing time and temperature, owing to the interplay of nucleation and growth processes during the residence in the metastable state. An interesting combination of micro and macroporosity was observed for long residence times in the metastable state (above 30 min at 35°C). Preliminary degradation tests in a biological mimicking fluid (D‐MEM with bovine serum) showed a significant weight loss during the initial stages (ca. 30% in 30 days) related to the degradation of the amorphous part, followed by a negligible weight loss in the next days (few percent from 30 to 60 days). © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2008
Corrosion of anodic TiO coatings on Ti–6Al–4V in simulated body fluid
Authors: Narayanan R. , Seshadri S. K. , Kwon Tae‐Yub , Kim Kyo‐Han 
Published: November 2007

AbstractAnodic TiO coatings were produced on Ti–6Al–4V substrates using aqueous electrolytes containing dissolved calcium and phosphorus. Two baths containing Ca and P compounds, in the molar ratios 5 and 15 were used. Different coatings were produced by electrolysis for 3 and 10 h at a constant current density of 10 mA/cm2. X‐ray diffraction and X‐ray fluorescence were used to identify the phases and chemical composition respectively. Thickness of the coatings was measured using ellipsometry. Electrochemical polarization and AC impedance studies were performed on the coatings by exposing them to simulated body fluid (SBF) for a period of 1 week. The coating produced by 10‐h electrolysis from bath of Ca/P ratio 15 showed low corrosion current and high impedance to the week‐long attack of SBF. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2008
Influence of pulse repetition rate of Er:YAG laser and dentin depth on tensile bond strength of dentin–resin interface
Authors: Gonçalves Mariane , Corona Silmara Aparecida Milori , Palma‐Dibb Regina Guenka , Pécora Jesus Djalma 
Published: November 2007

AbstractThe study evaluated the in vitro influence of pulse‐repetition rate of Er:YAG laser and dentin depth on tensile bond strength of dentin–resin interface. Dentin surfaces of buccal or lingual surfaces from human third molars were submitted to tensile test in different depths (superficial, 1.0 and 1.5 mm) of the same dental area, using the same sample. Surface treatments were acid conditioning solely (control) and Er:YAG laser irradiation (80 mJ) followed by acid conditioning, with different pulse‐repetition rates (1, 2, 3, or 4 Hz). Single bond/Z‐250 system was used. The samples were stored in distilled water at 37°C for 24 h, and then the first test (superficial dentine) was performed. The bond failures were analyzed. Following, the specimens were identified, grounded until 1.0‐ and 1.5‐mm depths, submitted again to the treatments and to the second and, after that, to third‐bond tests on a similar procedure and failure analysis. ANOVA and Tukey test demonstrated a significant difference (p < 0.001) for treatment and treatment × depth interaction (p < 0.05). The tested depths did not show influence (p > 0.05) on the bond strength of dentin–resin interface. It may be concluded that Er:YAG laser with 1, 2, 3, or 4 Hz combined with acid conditioning did not increase the resin tensile bond strength to dentin, regardless of dentin depth. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2008
Rheological characterization of photopolymerized poly(vinyl alcohol) hydrogels for potential use in nucleus pulposus replacement
Authors: Bader Rebecca A. , Rochefort Willie E. 
Published: November 2007

AbstractHydrogels have been proposed as candidates for nucleus pulposus replacement because of their similarity in mechanical behavior to the native tissue when subjected to transient or static loading; however, given the viscoelastic nature of soft biological tissues, the lack of dynamic testing is a significant inadequacy in the studies performed to date. In the present work, the viscoelastic behavior of a hydrogel system obtained via photopolymerization of glycidyl methacrylate modified poly(vinyl alcohol) (PVA) was evaluated in comparison to that of the nucleus pulposus when subjected to dynamic torsional shear. The complex shear moduli and phase shift angles were modulated through the variation of PVA molecular weight and concentration of polymer prior to photopolymerization. Hydrolysis resistance was assessed by evaluation of the viscoelastic behavior of hydrogels submerged in Hank's solution for progressively longer periods of time. The phase shift angles of all hydrogels were lower than those of the nucleus pulposi; however, the complex shear moduli of the synthetic system spanned the values observed for the natural system. Over the time frame of the experiment, no changes in moduli were observed following submersion in Hank's solution. This study represents the first attempt to successfully mimic the viscoelastic nature of the nucleus pulposus exhibited under dynamic torsional loading with that of materials intended for use in tissue replacement. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2008
Self‐assembled, fluorescent polymeric micelles of a graft copolymer containing carbazole for thermo‐controlled drug delivery in vitro
Authors: Liu Yunhai , Wu Jibing , Meng Lingzhi , Zhang Lifen , Lu Xiaoju 
Published: November 2007

AbstractA novel thermosensitive amphiphilic graft copolymer PNIPAAm‐g‐PCbzEA appending carbazole group was successfully designed and synthesized by the free radical copolymerization of N‐isopropylacrylamide with hydrophobic precursor polymers of vinyl‐functionalized poly(2‐(N‐carbazolyl)ethyl acrylate) (PCbzEA) in DMF. The PNIPAAm‐g‐PCbzEA copolymer was characterized by FTIR, 1H NMR, GPC analysis, UV–vis spectroscopy and fluorescence spectroscopy. The TEM observation shows that the graft copolymer may self‐assemble into polymeric micelles exhibiting a nanospheric morphology within a narrow size range of 30–60 nm in aqueous solution. From the 1H NMR and FTIR analysis, the polymer micelles are composed of hydrophobic PCbzEA segments as the cores and the hydrophilic PNIPAAm segements as outer shells. The resulting micelles exhibited the temperature sensitivity with a lower critical solution temperature (LCST) of 31.5°C and a critical micelle concentration (CMC) of 12.9 mg/L in water. In the study of drug release, an “on–off” drug release profile was found in response to stepwise temperature changes between 20 and 40°C. The cytotoxicity assays for vero cells shows good biocompatibility of the graft copolymer in vitro. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2008
Immunosuppressive drug‐free operational immune tolerance in human kidney transplants recipients. Part II. Non‐statistical gene microarray analysis
Authors: Sivozhelezov Victor , Braud Christophe , Giacomelli Luca , Pechkova Eugenia , Giral Magali , Soulillou Jean‐Paul , Brouard Sophie , Nicolini Claudio 
Published: November 2007

AbstractKidney transplant is the reference treatment for patients with end‐stage renal disease, but patients may develop long‐term rejection of the graft. However, some patients do not reject the transplant, but instead are operationally tolerant state despite withdrawal of immunosuppressive treatment. In this second article we outline a microarray‐based identification of key leader genes associated respectively to rejection and to operational tolerance of the kidney transplant in humans by utilizing a non/statistical bioinformatic approach based on the identification of “key genes,” either as those mostly changing their expression, or having the strongest interconnections. A uniquely informative picture emerges on the genes controlling the human transplant from the detailed comparison of these findings with the traditional statistical SAM (Tusher et al. 2001 Proc Natl Acad Sci USA 98:5116–5121) analysis of the microarrays and with the clinical study carried out in the accompanying part I article. J. Cell. Biochem. 103: 1693–1706, 2008. © 2007 Wiley‐Liss, Inc.
Understanding the pathology and mechanisms of type I diabetic bone loss
Authors: McCabe Laura R. 
Published: November 2007

AbstractType I (T1) diabetes, also called insulin dependent diabetes mellitus (IDDM), is characterized by little or no insulin production and hyperglycemia. One of the less well known complications of T1‐diabetes is bone loss which occurs in humans and animal models. This complication is receiving increased attention because T1‐diabetics are living longer due to better therapeutics, and are faced with their existing health concerns being compounded by complications associated with aging, such as osteoporosis. Both male and female, endochondrial and intra‐membranous, and axial and appendicular bones are susceptible to T1‐diabetic bone loss. Exact mechanisms accounting for T1‐diabetic bone loss are not known. Existing data indicate that the bone defect in T1‐diabetes is anabolic rather than catabolic, suggesting that anabolic therapeutics may be more effective in preventing bone loss. Potential contributors to T1‐diabetic suppression of bone formation are discussed in this review and include: increased marrow adiposity, hyperlipidemia, reduced insulin signaling, hyperglycemia, inflammation, altered adipokine and endocrine factors, increased cell death, and altered metabolism. Differences between T1‐diabetic‐ and age‐associated bone loss underlie the importance of condition specific, individualized treatments for osteoporosis. Optimizing therapies that prevent bone loss or restore bone density will allow T1‐diabetic patients to live longer with strong healthy bones. J. Cell. Biochem. 102: 1343–1357, 2007. © 2007 Wiley‐Liss, Inc.
VEGF in biological control
Authors: Breen Ellen C. 
Published: November 2007

AbstractVascular endothelial growth factor A (VEGF‐A) belongs to a family of heparin binding growth factors that include VEGF‐B, VEGF‐C, VEGF‐D, and placental‐like growth factor (PLGF). First discovered for its ability to regulate vascular endothelial cell permeability, VEGF is a well‐known angiogenic factor that is important for vascular development and maintenance in all mammalian organs. The development of molecular tools and pharmacological agents to selectively inhibit VEGF function and block angiogenesis and/or vascular permeability has led to great promise in the treatment of various cancers, macular degeneration, and wound healing. However, VEGF is also important in animals for the regulation of angiogenesis, stem cell and monocyte/macrophage recruitment, maintenance of kidney and lung barrier functions and neuroprotection. In addition to its role in regulating endothelial cell proliferation, migration, and cell survival, VEGF receptors are also located on many non‐endothelial cells and act through autrocrine pathways to regulate cell survival and function. The following review will discuss the role of VEGF in physiological angiogenesis as well as its role in non‐angiogenic processes that take place in adult organs. J. Cell. Biochem. 102: 1358–1367, 2007. © 2007 Wiley‐Liss, Inc.
A new, unexpected action of olomoucine, a CDK inhibitor, on normal human cells: Up‐regulation of CLIMP‐63, a cytoskeleton‐linking membrane protein
Authors: Węsierska‐Gądek Józefa , Gueorguieva Marieta , Kramer Matthias P. , Ranftler Carmen , Sarg Bettina , Lindner Herbert 
Published: November 2007

AbstractInhibition of cyclin‐dependent kinases (CDKs) is a novel strategy in the therapy of human malignancies. The pharmacological CDK inhibitors representing a few distinct classes of compounds exert different target specificity. Considering the fact that dividing and quiescent cells differ in their CDK activity and in the pattern of their expression, one might expect that anti‐proliferative efficiency of the pharmacological CDK inhibitors would depend on the mitotic index of treated cells. The present article shows that olomoucine (OLO), a weak CDK2 inhibitor has new, unexpected activity. At concentrations up to 100 µM OLO did not inhibit proliferation of normal human cells, but arrested growth of human HL‐60 leukemia cells. The anti‐proliferative effect of OLO was clearly weaker than that of roscovitine (ROSC). Surprisingly, OLO at low doses strongly up‐regulated a cellular protein with approximately 65 kDa in normal, but not in immortalized and cancer cells. By mass spectrometric analysis CLIMP‐63, a cytoskeleton‐linking membrane protein was identified as the major component of the up‐regulated protein band. These results were subsequently confirmed by immunoblotting. Further experiments revealed that OLO, but not ROSC, strongly up‐regulates CLIMP‐63 in a dose‐ and time‐dependent manner solely in senescent cells. J. Cell. Biochem. 102: 1405–1419, 2007. © 2007 Wiley‐Liss, Inc.