bluuebunny/crossref_metadata_2025_split huggingface dataset:
Hypoxic expansion promotes the chondrogenic potential of articular chondrocytes
Authors: Egli Rainer J. , Bastian Johannes D. , Ganz Reinhold , Hofstetter Willy , Leunig Michael 
Published: February 2008

AbstractFor cell‐based cartilage repair strategies, an ex vivo expansion phase is required to obtain sufficient numbers of cells needed for therapy. Although recent reports demonstrated the central role of oxygen for the function and differentiation of chondrocytes, a beneficial effect of low oxygen concentrations during the expansion of the cells to further improve their chondrogenic capacity has not been investigated. Therefore, freshly harvested bovine articular chondrocytes were grown in two‐dimensional monolayer cultures at 1.5% and 21% O2 and redifferentiation was subsequently induced in three‐dimensional micromass cultures at 1.5%, 5%, and 21% O2. Cells expanded at 1.5% O2 were characterized by low citrate synthase (aerobic energy metabolism)—and high LDH (anaerobic energy metabolism)—activities, suggesting an anaerobic energy metabolism. Collagen type II mRNA was twofold higher in cells expanded at 1.5% as compared to expansion at 21% O2. Micromass cultures grown at 21% O2 showed up to a twofold increase in the tissue content of glycosaminoglycans when formed with cells expanded at 1.5% instead of 21% O2. However, no differences in the levels of transcripts and in the staining for collagen type II protein were observed in these micromass cultures. Hypoxia (1.5% and 5% O2) applied during micromass cultures gave rise to tissues with low contents of glycosaminoglycans only. In vivo, the chondrocytes are adapted to a hypoxic environment. Taking this into account, by applying 1.5% O2 in the expansion phase in the course of cell‐based cartilage repair strategies, may result in a repair tissue with higher quality by increasing the content of glycosaminoglycans. © 2008 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 26:977–985, 2008
p38 MAPK inhibition modulates rabbit nucleus pulposus cell response to IL‐1
Authors: Studer Rebecca K. , Gilbertson Lars G. , Georgescu Helga , Sowa Gwendolyn , Vo Nam , Kang James D. 
Published: February 2008

AbstractAnalysis of disc gene expression implicated IL‐1 in the development of intervertebral disc degeneration (IDD) in a rabbit stab model. The purpose of these studies is to determine the role of p38 Mitogen Activated Protein Kinase (p38 MAPK) signaling in nucleus pulposus cell response to IL‐1, and to compare rabbit nucleus pulposus (rNP) cell responses to IL‐1 activation with those in a stab model of disc degeneration. NP cells maintained in alginate bead culture were exposed to IL‐1, with or without p38 MAPK inhibition. RNA was isolated for reverse transcription polymerase chain reaction (RT‐PCR) analysis of gene expression, conditioned media analyzed for accumulation of nitric oxide (NO) and prostaglandin E‐2 (PGE‐2), and proteoglycan synthesis measured after 10 days. IL‐1 upregulation of mRNA for cycloxygenase‐2 (COX‐2), matrix metalloproteinase‐3 (MMP‐3), IL‐1, and IL‐6, was blunted by p38 inhibition while downregulation of matrix proteins (collagen I, collagen II, aggrecan) and insulin‐like‐growth‐factor I (IFG‐1) was also reversed. mRNA for tissue inhibitor of matrixmetalloproteinase‐1 (TIMP‐1) was modestly increased by IL‐1, while those for Transforming Growth Factor‐β (TGF‐β) SOX‐9, and versican remained unchanged. Blocking p38 MAPK reduced IL‐1 induced NO and PGE‐2 accumulation and partially restored proteoglycan synthesis. p38 MAPK inhibition in control cells increased mRNA for matrix proteins (aggrecan, collagen II, versican, collagen I) and anabolic factors (IGF‐1, TGF, and SOX‐9) from 50% to 120%, decreased basal PGE‐2 accumulation, but had no effect on message for TIMP‐1, MMP‐3, or COX‐2. Inhibition of p38 MAPK in cytokine‐activated disc cells blunts gene expression and production of factors associated with inflammation, pain, and disc matrix catabolism while reversing IL‐1 downregulation of matrix protein gene expression and proteoglycan synthesis. The results support the hypothesis that IL‐1 could be responsible for many of the mRNA changes seen in rabbit NP in the stab model of disc degeneration, and uphold the concept that development of molecular techniques to block p38 MAPK could provide a therapeutic approach to slow the course of intervertebral disc degeneration. © 2008 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 26:991–998, 2008
Role of the fibula in lower leg fractures: An in vivo investigation in rats
Authors: Horn Joachim , Steen Harald , Reikerås Olav 
Published: February 2008

AbstractWhether or not the fibula should be fixated in combined fractures of the tibia and fibula remains controversial. Several clinical and biomechanical studies have investigated the role of the fibula in lower leg fractures without leading to a common conclusion. We assumed that an intact or stable fibula would provide better healing conditions in lower leg fractures treated with an intramedullary nail. In an in vivo study, 40 male Wistar rats were randomly assigned to two groups. In both groups, the tibia was osteotomized, whereas the fibula was left intact in one group and osteotomized in the other group. The tibia fracture was fixated with an intramedullary nail. After sacrifice of the animals, mineral density, mineral content, and mechanical characteristics of the healing osteotomies were evaluated. We found that a combination of tibia and fibula fracture significantly impaired fracture healing during the early phase after the incident, when treated with an intramedullary nail, suggesting that an intact or stabilized fibula provides additional support and better healing conditions to a tibia fracture. © 2008 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 26:1027–1031, 2008
Chromium picolinate can ameliorate the negative effects of heat stress and enhance performance, carcass and meat traits in broiler chickens by reducing the circulatory cortisol level
Authors: Samanta Saikat , Haldar Sudipto , Bahadur Vijay , Ghosh Tapan K 
Published: February 2008

AbstractBACKGROUND: Dietary chromium (Cr3+) supplementation reduces stress in livestock by lowering circulatory cortisol and potentiating the action of insulin. This study aimed to assess the stress‐alleviating effects of supplemental Cr3+ as chromium picolinate in broilers.RESULTS: The birds, which were heat stressed and had restricted feed intake between 31 and 40 days of age, were supplemented with 0 (control), 0.5 or 1 mg Cr3+ kg−1 diet from 10 to 40 days of age. Live weight gain, feed efficiency, utilisation efficiency of energy and protein and conversion efficiency of feed protein to muscle protein improved owing to Cr3+ supplementation (P < 0.05), especially during the period of feed restriction. Cr3+ supplementation increased hot and eviscerated carcass weights and breast weight (P < 0.05) and reduced ether extract content (P = 0.02, linear effect). Meat protein accretion improved owing to Cr3+ supplementation (P = 0.006, quadratic effect). Relative to its pre‐supplementation value, serum cortisol increased by 2.3% in the control group and decreased by 7.6 and 14.3% in the 0.5 and 1 mg Cr3+‐supplemented birds respectively (age × diet interaction P = 0.0001).CONCLUSION: It was concluded that supplemental Cr3+ may ameliorate heat stress and augment growth in broilers during periods of physical feed restriction. However, increasing the inclusion of Cr3+ beyond the dose level of 0.5 mg kg−1 diet may not be substantially beneficial. Copyright © 2007 Society of Chemical Industry
The psychological impact of impending forced settler disengagement in Gaza: Trauma and posttraumatic growth
Authors: Hall Brian J. , Hobfoll Stevan E. , Palmieri Patrick A. , Canetti‐Nisim Daphna , Shapira Oren , Johnson Robert J. , Galea Sandro 
Published: February 2008

AbstractThe Israeli government's decision to remove settlers in the Gaza Strip forcibly produced a situation of traumatic stress, resulting from confrontation and conflict for settlers. The authors examined the effects of the Gaza disengagement, that occurred following prolonged terrorist exposure, on rates of probable major depressive disorder (MDD) and posttraumatic stress disorder (PTSD) diagnosis in a representative sample of Gaza settlers (N = 190). Predictors of probable MDD in multivariate models were being female, and experiencing greater economic and psychosocial resource loss. Predictors of probable PTSD were being older and experiencing greater psychosocial resource loss. Posttraumatic growth was significantly related to a reduction in the odds of having probable PTSD. This latter finding is interpreted within our conceptualization of action‐focused growth.
The internalizing and externalizing structure of psychiatric comorbidity in combat veterans
Authors: Miller Mark W. , Fogler Jason M. , Wolf Erika J. , Kaloupek Danny G. , Keane Terence M. 
Published: February 2008

AbstractThis study examined the latent structure of psychiatric disorders in a sample with a high prevalence of PTSD. A series of confirmatory factor analyses tested competing models for the covariation between Structured Clinical Interview for DSM‐III‐R diagnoses among 1,325 Vietnam veterans. The best‐fitting solution was a 3‐factor model that included two correlated internalizing factors: anxious‐misery, defined by PTSD and major depression, and fear, defined by panic disorder/agoraphobia and obsessive‐compulsive disorder. The third factor, externalizing, was defined by antisocial personality disorder, alcohol abuse/dependence, and drug abuse/dependence. Both substance‐related disorders also showed significant, albeit smaller, cross‐loadings on the anxious‐misery factor. These findings shed new light on the structure of psychiatric comorbidity in a treatment‐seeking sample characterized by high rates of PTSD.
The association of exposure, risk, and resiliency factors with PTSD among Jews and Arabs exposed to repeated acts of terrorism in Israel
Authors: Hobfoll Stevan E. , Canetti‐Nisim Daphna , Johnson Robert J. , Palmieri Patrick A. , Varley Joseph D. , Galea Sandro 
Published: February 2008

AbstractIsrael has faced ongoing terrorism since the beginning of the Al Aqsa Intifada in September 2000. The authors examined risk and resiliency factors associated with posttraumatic stress disorder (PTSD) among 1,117 Jews and 394 Arab adult citizens of Israel during August and September 2004 through telephone interviews. Probable PTSD was found among 6.6% of Jews and 18.0% of Arabs. Predictors of probable PTSD in a multivariate model for Jews were refusal to report income, being traditionally religious, economic and psychosocial resource loss, greater traumatic growth, and lower social support. For Arabs, predictors were low education and economic resource loss among those exposed to terrorism. Findings for only those directly exposed to terrorism were similar to those for the overall national sample.
Fucoidan from Laminaria cichorioides inhibits AP‐1 transactivation and cell transformation in the mouse epidermal JB6 cells
Authors: Lee Na Yeon , Ermakova Svetlana P. , Choi Hoo‐Kyun , Kusaykin Michail I. , Shevchenko Natalya M. , Zvyagintseva Tatyana N. , Choi Hong Seok 
Published: February 2008

AbstractFucoidan, a sulfated polysaccharide extracted from brown seaweeds, has anticoagulant and antithrombotic activities. Unlike heparine, fucoidan is known to exhibit anticarcinogenic activities. However, the underlying molecular mechanisms of the chemopreventive activities of fucoidan are not understood. Here we report that fucoidan from Laminaria cichorioides inhibited the epidermal growth factor (EGF) or 12‐O‐tetradecanoylphorbol‐13‐acetate (TPA)‐induced neoplastic cell transformation, but had less cytotoxic effects on JB6 mouse epidermal cells. The EGF‐induced phosphorylation of extracellular signal‐regulated kinases 1/2 and c‐Jun N‐terminal kinases, and c‐Jun was inhibited by fucoidan, resulting from the inhibition of phosphorylation of epidermal growth factor receptor (EGFR). Fucoidan dose‐dependently attenuated the c‐fos or c‐jun transcriptional activity, and thereby inhibited the associated activator protein‐1 (AP‐1) transactivation activity. In vitro binding assay revealed that fucoidan directly interacted with EGF, suggested that antitumor promoting effect of fucoidan might be due to preventing the binding of EGF to its cell surface receptor (EGFR). These findings are the first to reveal a molecular basis for the anticarcinogenic action of fucoidan and may partially account for the reported chemopreventive effects of brown seaweeds. © 2008 Wiley‐Liss, Inc.
In vivo imaging of a diabetogenic CD8+ T cell response during type 1 diabetes progression
Authors: Medarova Zdravka , Tsai Sue , Evgenov Natalia , Santamaria Pere , Moore Anna 
Published: February 2008

AbstractType 1 diabetes is preceded by a long, protracted period of pancreatic islet inflammation by autoreactive lymphocytes. Noninvasive imaging of islet inflammation prior to the onset of hyperglycemia might have diagnostic and therapeutic implications, but this is not currently possible. Here, MRI is used to track, noninvasively, the accumulation diabetogenic CD8+ T‐cells during type 1 diabetes progression in nonobese diabetic (NOD) mice. The contrast agent is an MRI probe (MN‐NRP‐V7) that specifically labels CD8+ T‐cells recognizing residues 206–214 of islet‐specific glucose‐6‐phosphatase catalytic subunit related protein (IGRP206–214) in the context of the major histocompatibility complex (MHC) class I molecule H‐2Kd. This probe consists of superparamagnetic iron oxide nanoparticles (MN) coated with Kd molecules presenting NRP‐V7, a high‐avidity mimotope of IGRP206–214. NOD mice of different ages (5, 8, 15, and 24 weeks) were imaged by MRI before and after a single intravenous injection of MN‐NRP‐V7 or unmodified MN nanoparticles. MN‐NRP‐V7 accumulation, as determined by semiquantitative MRI analysis of pancreas‐associated T2 relaxation time, was antigen‐specific, age‐dependent, and well correlated with the numbers of MN‐NRP‐V7‐labeled CD8+ T‐cells recovered from the pancreata of the treated mice. Antigen/MHC‐coupled nanoparticles represent a promising new avenue for noninvasive imaging of lymphocyte inflammation in organ‐specific autoimmunity and transplantation. Magn Reson Med, 2008. © 2008 Wiley‐Liss, Inc.
Isomerization and rearrangement of (E)‐ and (Z)‐phenylhydrazones of 3‐benzoyl‐5‐phenyl‐1,2,4‐oxadiazole: evidence for a ‘new’ type of acid‐catalysis by copper(II) salts in mononuclear rearrangement of heterocycles
Authors: D'Anna Francesca , Frenna Vincenzo , Guernelli Susanna , Macaluso Gabriella , Marullo Salvatore , Spinelli Domenico 
Published: February 2008

AbstractA kinetic investigation in methanol of the title reaction has evidenced the occurrence of two processes: the 1‐E $ \mathbin{\lower.3ex\hbox{$\buildrel\textstyle\rightarrow\over {\smash{\leftarrow}\vphantom{_{\vbox to.5ex{\vss}}}}$}} $ 1‐Z isomerization and the rearrangement of the (Z)‐isomer into the relevant 4‐benzoylamino‐2,5‐diphenyl‐1,2,3‐triazole (1‐
Z → T). The latter reaction is in line with the ability of the (Z)‐phenylhydrazones of 3‐benzoyl‐1,2,4‐oxadiazoles to undergo the so called mononuclear rearrangement of heterocycles (MRH). The occurrence of both the examined reactions is dependent on a Lewis‐acid‐catalysis. The obtained results have shown the possibility of a ‘new’ type of acid‐catalysis (bifunctional catalysis by Lewis salts) in the MRH. This catalysis operates through a completely different mechanism with respect to the one recently observed, and deeply investigated, in the presence of protic acids for the (Z)‐phenylhydrazone of 5‐amino‐3‐benzoyl‐1,2,4‐oxadiazole, in both dioxane/water and toluene, for which the catalytic process was dependent on the protonation of N(4) ring‐nitrogen of the 1,2,4‐oxadiazole. As a matter of fact, the copper salts seem able to interact with the >CNNHC6H5 moiety, yielding adducts which, in some cases, are prone to both isomerize and rearrange. Therefore, a similar behaviour in some manner parallel to that already observed in benzene in the presence of aliphatic amines (base‐catalysis) has been evidenced. Copyright © 2008 John Wiley & Sons, Ltd.
Synthesis and properties of amino acid esters of hydroxypropyl cellulose
Authors: Khan Fareha Zafar , Shiotsuki Masashi , Sanda Fumio , Nishio Yoshiyuki , Masuda Toshio 
Published: February 2008

AbstractThe amino acid esters of hydroxypropyl cellulose (HPC) [R′ = H (2a), CH3 (2b), CH2CH(CH3)2 (2c), CH2CONH2 (2d), CH2CH2CONH2 (2e), CH2CH2CH2CH2 NHOCOC(CH3)3 (2f)] were synthesized in good yield by the reaction of t‐butoxycarbonyl (t‐Boc)‐protected amino acids with hydroxy groups of HPC (1; molar substitution (MS), 4.61). The amino acid functionalities displaying varied chemical nature, shape, and bulk were utilized and the bulk of the substituent on the α‐carbon of amino acids was elucidated to be of vital significance for the observed degree of incorporation (DSEst). The 1H NMR spectra and elemental analysis were employed to determine the degree of incorporation of amino acid moiety (DSEst) and almost complete substitution of the hydroxy protons was revealed for 2a, 2b, and 2f. The presence of the peaks characteristic of the carbonyl group in the FTIR spectra furnished further evidence for the successful esterification of HPC. The starting as well as the resulting polymers (1 and 2a–f) were soluble in polar organic solvents; however, the esterification of 1 with bulky organic moieties resulted in an increased hydrophobicity as all of the amino acid‐functionalized polymers (2a–f) were insoluble in water. The onset temperatures of weight loss of 2a–f were 175–230 °C, indicating fair thermal stability. The amino acid functionalization led to the enhanced polymer chain stiffness, and the glass transition temperatures of the derivatized polymers were 30–40 °C higher than that of 1 (Tg 3.9 °C; cf. Tg of 2a–f, 35.1–43.3 °C). © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 2326–2334, 2008
Arborescent polystyrene‐graft‐poly(tert‐butyl methacrylate) copolymers: Synthesis and enhanced polyelectrolyte effect in solution
Authors: Kee R. Andrew , Gauthier Mario 
Published: February 2008

AbstractA technique is described for the preparation of arborescent graft copolymers containing poly(tert‐butyl methacrylate) (PtBMA) segments. For this purpose, tert‐butyl methacrylate is first polymerized with 1,1‐diphenyl‐2‐methylpentyllithium in tetrahydrofuran. The graft copolymers are obtained by addition of a solution of a bromomethylated polystyrene substrate to the living PtBMA macroanion solution. Copolymers incorporating either short (Mw ≈ 5000) or long (Mw ≈ 30,000) PtBMA side chains were prepared by grafting onto linear, comb‐branched (G0), G1, and G2 bromomethylated arborescent polystyrenes. Branching functionalities ranging from 9 to 4500 and molecular weights ranging from 8.8 × 104 to 6.3 × 107 were obtained for the copolymers, while maintaining a low apparent polydispersity index (Mw/Mn ≈ 1.14–1.25). Arborescent polystyrene‐graft‐poly(methacrylic acid) (PMAA) copolymers were obtained by hydrolysis of the tert‐butyl methacrylate units. Dynamic light scattering measurements showed that the arborescent PMAA copolymers are more expanded than their linear PMAA analogues when neutralized with NaOH. This effect is attributed to the higher charge density in the branched arborescent copolymer structures. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 2335–2346, 2008
Synthesis and characterization of functional polyesters tailored for biomedical applications
Authors: Cerbai Benedetta , Solaro Roberto , Chiellini Emo 
Published: February 2008

AbstractThis work aimed at the development of bioactive polymeric materials to be used for targeted drug delivery and tissue engineering applications. The proposed strategy was based on the design of macromolecular systems whose functionality can be easily modified. Polyesters containing side‐chain end capped by primary hydroxyl groups were synthesized by polyaddition of oxetanes and carboxylic anhydrides catalyzed by quaternary onium salts. The polyaddition of bis(oxetane) with different dicarboxylic acids was also investigated. In all cases, oxetane monomers contained one hydroxyl group either free or protected by a benzyl group. The polymer yield and molecular weight were relatively high when aromatic anhydrides were used. In all other cases, low conversions or no polymerization at all were obtained. In a parallel research line, several alkanols were successfully employed to synthesize different α,β′,β‐trisubstituted‐β‐lactones. These monomers were prepared in five steps starting from diethyl oxalpropionate according to established synthetic routes. Final yields depended on both preparation method and side‐chain structure. By using quaternary ammonium salts as catalysts, the synthesized functional lactones underwent anionic ring opening polymerization leading to the corresponding homopolymers and copolymers in fairly good yields. The prepared polymeric materials were extensively characterized by spectroscopic techniques, size exclusion chromatography, and thermal analysis. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 2459–2476, 2008
Breakdown kinetics of aggregates from poly(ethylene glycol‐bl‐propylene sulfide) di‐ and triblock copolymers induced by a non‐ionic surfactant
Authors: Cerritelli Simona , Velluto Diana , Hubbell Jeffrey A. , Fontana Antonella 
Published: February 2008

AbstractWe explored the effects of addition of the nonionic surfactant Triton X‐100 on the stability of aggregates of poly(ethylene glycol‐bl‐propylene sulfide) di‐ and triblock copolymers. Fluorescence spectra of pyrene, used as a probe molecule, elucidated the various stages of transformation from pure copolymeric micelles to surfactant‐rich micelles. Turbidity measurements yielded insight into the mechanism of the interaction, the hydrophobicity of the copolymer driving the process. Triton X‐100 tends to strongly interact with highly hydrophobic copolymers by inserting into the core of the micellar aggregates. On the other hand, Triton X‐100 tends to interact with the corona of micelles formed by less hydrophobic copolymers which, for this reason, are more stable upon addition of this destabilizing agent. Kinetic data give evidence that only monomers, not micelles of surfactant, interact with the copolymer micelles. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 2477–2487, 2008