bluuebunny/crossref_metadata_2025 huggingface dataset:
Epigenetic modifications in osteogenic differentiation and transformation
Authors: Thomas David , Kansara Maya
Published: April 2006

Almost all tumors are characterized by both architectural and cellular abnormalities in differentiation. Osteoblast development is relatively well understood, making osteosarcoma a good model for understanding how tumorigenesis perturbs normal differentiation. We argue that there are two key transition points in normal cellular differentiation that are the focus of oncogenic events, in both of which epigenetic processes are critical. The first is the transition from an uncommitted pluripotent precursor (mesenchymal stem cell) to the ‘transit‐amplifying compartment’ of the osteoblast lineage. This transition, normally exquisitely regulated in space and time, is abnormal in cancer. The second involves termination of lineage expansion, equally tightly regulated under normal circumstances. In cancer, the mechanisms that mandate eventual cessation of cell division are almost universally disrupted. This model predicts that key differentiation genes in bone, such as RUNX2, act in an oncogenic fashion to initiate entry into a proliferative phase of cell differentiation, and anti‐oncogenically into the post‐mitotic state, resulting in ambivalent roles in tumorigenesis. Polycomb genes exemplify epigenetic processes in the stem cell compartment and tumorigenesis, and are implicated in skeletal development in vivo. The epigenetic functions of the retinoblastoma protein, which plays a key role in tumorigenesis in bone, is discussed in the context of terminal cell cycle exit. J. Cell. Biochem. 98: 757–769, 2006. © 2006 Wiley‐Liss, Inc.
Chaperone‐like activity revealed in the matricellular protein SPARC
Authors: Emerson Ryan O. , Sage E. Helene , Ghosh Joy G. , Clark John I.
Published: April 2006

SPARC (Secreted Protein, Acidic and Rich in Cysteine) is a matricellular glycoprotein that modulates cell proliferation, adhesion, migration, and extracellular matrix (ECM) production. In this report chaperone‐like activity of SPARC was identified in a thermal aggregation assay in vitro. Ultraviolet circular dichroism (UVCD) spectroscopy determined that SPARC was stable at temperatures up to 50°C. Unfolding and aggregation of the chaperone target protein, alcohol dehydrogenase (ADH), were initiated at 50°C. SPARC inhibited the thermal aggregation of ADH in a concentration‐dependent manner, with maximal inhibition at a 1:4 molar ratio of SPARC:ADH. Synergy between the chaperone‐like activities of SPARC and αB‐crystallin, a small heat shock protein and molecular chaperone in the lens, was observed in SPARC‐αB‐crystallin double −/− mice. J. Cell. Biochem. 98: 701–705, 2006. © 2006 Wiley‐Liss, Inc.
Modulation of mouse RANKL gene expression by Runx2 and PKA pathway
Authors: Mori Kiyoshi , Kitazawa Riko , Kondo Takeshi , Maeda Sakan , Yamaguchi Akira , Kitazawa Sohei
Published: April 2006

Runx2 regulates the target genes characteristic of osteoblastic phenotypes, while exerting diverse and sometimes controversial effects on osteoblastic cells depending on their differentiation stage. Receptor activator of nuclear factor‐κB (RANK) ligand (RANKL) is a membrane bound cytokine essential for osteo(chondro)clastogenesis. During endochondral ossification, while Runx2‐positive hypertrophic chondrocytes express RANKL, the steady‐state expression of the RANKL gene in osteoblastic cells is, at later stages, kept at a relatively low level to sustain the established bone. The aim of this study was to elucidate the mechanism whereby Runx2 and the protein kinase A (PKA) pathway modulate RANKL expression, especially from the viewpoint of their functions in RANKL basic promoter activity and in chromatin structural changes in osteoblastic/stromal cells. Osteoblastic/stromal cell lines derived from normal and Runx2‐deficient mice were used to analyze endogenous RANKL gene expression by real‐time reverse transcription (RT)‐PCR, the acetylation status of the H3 and H4 histone proteins associated with the 5′‐flanking region of the RANKL gene by chromatin immunoprecipitation, and the exogenously transfected RANKL gene promoter activity both in the steady‐state and under PKA‐activated conditions. Here, we demonstrate that Runx2 suppresses steady‐state RANKL gene expression by condensing chromatin, while showing a slightly positive effect on RANKL basic promoter activity. Besides acting through the CRE‐like region (−0.96 kb) of the RANKL gene promoter, forskolin (FK) treatment transactivates the RANKL gene by antagonizing the function of Runx2, by reducing Runx2 mRNA expression and by opening the chromatin conformation far upstream (more than 40 kb) of the RANKL gene. J. Cell. Biochem. © 2006 Wiley‐Liss, Inc.
Androgen axis in prostate cancer
Authors: Culig Zoran , Bartsch Georg
Published: April 2006

Endocrine therapy for advanced prostate cancer is based on androgen ablation or blockade of the androgen receptor (AR). AR action in prostate cancer has been investigated in a number of cell lines, their derivatives, and transgenic animals. AR expression is heterogenous in prostate cancer in vivo; it could be detected in most primary tumors and their metastases. However, some cells lack the AR because of epigenetic changes in the gene promoter. AR expression increases after chronic androgen ablation in vitro. In several xenografts, AR upregulation is the most consistent change identified during progression towards therapy resistance. In contrast, the AR pathway may be by‐passed during chronic treatment with a nonsteroidal anti‐androgen. AR sensitivity in prostate cancer increases as a result of activation of the Ras/mitogen‐activated protein kinase pathway. One of the major difficulties in endocrine therapy for prostate cancer is acquisition of agonistic properties of AR antagonists observed in the presence of mutated AR. Enhancement of AR function by associated coactivator proteins has been extensively investigated. Cofactors SRC‐1, RAC3, p300/CBP, TIF‐2, and Tip60 are upregulated in advanced prostate cancer. Most studies on ligand‐independent activation of the AR are focused on Her‐2/neu and interleukin‐6 (IL‐6). On the basis of studies that showed overexpression and activation of the AR in advanced prostate cancer, it was suggested that novel therapies that reduce AR expression will provide a benefit to patients. There is experimental evidence showing that prostate tumor growth in vitro and in vivo is inhibited following administration of chemopreventive drugs or antisense oligonucleotides that downregulate AR mRNA and protein expression. J. Cell. Biochem. 99: 373–381, 2006. © 2006 Wiley‐Liss, Inc.
p27kip1 overexpression promotes paclitaxel‐induced apoptosis in pRb‐defective SaOs‐2 cells
Authors: Gabellini Chiara , Pucci Bruna , Valdivieso Paola , D'Andrilli Giuseppina , Tafani Marco , De Luca Antonio , Masciullo Valeria
Published: April 2006

p27kip1 is a cyclin‐dependent kinase (CDK) inhibitor, which controls several cellular processes in strict collaboration with pRb. We evaluated the role of p27kip1 in paclitaxel‐induced apoptosis in the pRb‐defective SaOs‐2 cells. Following 48 h of exposure of SaOs‐2 cells to 100 nM paclitaxel, we observed an increase in p27kip1 expression caused by the decrease of the ubiquitin‐proteasome activity. Such increase was not observed in SaOs‐2 cells treated with the caspase inhibitors Z‐VAD‐FMK, suggesting that p27kip1 enhancement at 48 h is strictly related to apoptosis. Finally, we demonstrated that SaOs‐2 cells transiently overexpressing the p27kip1 protein are more susceptible to paclitaxel‐induced apoptosis than SaOs‐2 cells transiently transfected with the empty vector. Indeed, after 48 h of paclitaxel treatment, 41.8% of SaOs‐2 cells transiently transfected with a pcDNA3‐p27kip1 construct were Annexin V‐positive compared to 30.6% of SaOs‐2 cells transfected with the empty vector (P < 0.05). In conclusion, we demonstrated that transfection of the pRb‐defective SaOs‐2 cells with the p27kip1 gene via plasmid increases their susceptibility to paclitaxel‐induced apoptosis. The promoting effect of p27kip1 overexpression on apoptosis makes p27kip1 and proteasomal inhibitors interesting tools for therapy in patients with pRb‐defective cancers. J. Cell. Biochem. © 2006 Wiley‐Liss, Inc.
Existence of autocrine loop between interleukin‐6 and tranforming growth factor‐β1 in activated rat pancreatic stellate cells
Authors: Aoki Hiroyoshi , Ohnishi Hirohide , Hama Kouji , Shinozaki Satoshi , Kita Hiroto , Yamamoto Hironori , Osawa Hiroyuki , Sato Kiichi , Tamada Kiichi , Sugano Kentaro
Published: April 2006

Interleukin (IL)‐6 is a proinflammatory cytokine assumed to participate in pancreatic fibrosis by activating pancreatic stellate cells (PSCs). Autocrine TGF‐β1 is to central in PSC functional regulation. In this study, we examined IL‐6 secretion from culture‐activated rat PSCs and its regulatory mechanism. Activated PSCs express and secrete IL‐6. When anti‐TGF‐β1 neutralizing antibody was added in the culture medium, IL‐6 secretion from activated PSCs was inhibited, whereas exogenous TGF‐β1 added in the culture medium enhanced IL‐6 expression and secretion by PSCs in a dose dependent manner. Infection of PSCs with an adenovirus expressing dominant‐negative Smad2/3 attenuated basal and TGF‐β1‐stimulated IL‐6 expression and secretion of PSCs. We also demonstrated the reciprocal effect of PSCs‐secreted IL‐6 on autocrine TGF‐β1. Anti‐IL‐6 neutralizing antibody inhibited TGF‐β1 secretion from PSCs. Preincubation of cells with 10 nM PD98059, an extracellular signal‐regulated kinase (ERK)‐dependent pathway inhibitor, attenuated IL‐6‐enhanced TGF‐β1 expression and secretion of PSCs. In addition, IL‐6 activated ERK in PSCs. These data indicate the existence of autocrine loop between IL‐6 and TGF‐β1 through ERK‐ and Smad2/3‐dependent pathways in activated PSCs. J. Cell. Biochem. © 2006 Wiley‐Liss, Inc.
Methotrexate induced differentiation in colon cancer cells is primarily due to purine deprivation
Authors: Singh R. , Fouladi‐Nashta A.A. , Li D. , Halliday N. , Barrett D.A. , Sinclair K.D.
Published: April 2006

The folate antagonist methotrexate (MTX) inhibits synthesis of tetrahydrofolate (THF), pyrimidines and purines, and induces differentiation in several cell types. At 1 µM, MTX reduced proliferation and induced differentiation in HT29 colon cancer cells; the latter effect was augmented (P < 0.001) by thymidine (100 µM) but was reversed (P < 0.001) by the purines, hypoxanthine (Hx; 100 µM) and adenosine (100 µM). In contrast 5‐fluoro‐uracil (5‐FU), a specific thymidylate synthase (TS) inhibitor, had no effect on differentiation, suggesting that MTX‐induced differentiation is not due to a reduction in thymidine but to the inhibition of purine biosynthesis. Inhibition of cyclic AMP (cAMP) by RpcAMP (25 µM) further enhanced (P < 0.001) MTX induced differentiation, whereas the cAMP activator forskolin (10 µM) reversed (P < 0.001) MTX induced differentiation. These observations implicate a central role of adenosine and cAMP in MTX induced differentiation. By combining Western blot analysis with liquid chromatography‐mass spectrometry (LC‐MS)and HPLC analyses we also reveal both the expression and activity of key enzymes (i.e. methionine synthase (MS), s‐adenosylhomocysteinase, cystathionine β‐synthase and ornithine decarboxylase) regulating methyl cycle, transsulfuration and polyamine pathways in HT29 colon cancer cells. At 1 µM, MTX induced differentiation was associated with a marked reduction in the intracellular concentrations of adenosine and, consequently, S‐adenosylmethionine (SAM), S‐adenosylhomocysteine, polyamines and glutathione (GSH). Importantly, the marked reduction in methionine that accompanied MS inhibition following MTX treatment was non‐limiting with respect to SAM synthesis. Collectively, these findings indicate that the effects of MTX on cellular differentiation and single carbon metabolism are primarily due to the intracellular depletion of purines. J. Cell. Biochem. © 2006 Wiley‐Liss, Inc.
UVB‐induced 1,25(OH)2D3 production and vitamin D activity in intestinal CaCo‐2 cells and in THP‐1 macrophages pretreated with a sterol Δ7‐reductase inhibitor
Authors: Vantieghem Katleen , Overbergh Lut , Carmeliet Geert , De Haes Petra , Bouillon Roger , Segaert Siegfried
Published: April 2006

Epidermal keratinocytes are able to produce 1,25‐dihydroxyvitamin D3 [1,25(OH)2D3] and induce vitamin D activity upon UVB irradiation. To find out whether this property is keratinocyte specific, we investigated this characteristic in two other cell types, namely intestinal CaCo‐2 cells and the macrophage‐like differentiated THP‐1 cells. THP‐1 macrophages and preconfluent CaCo‐2 cells contain the vitamin D receptor (VDR), possess 25‐hydroxylase (CYP2R1 and CYP27A1) and 1α‐hydroxylase (CYP27B1) activity, and survive the low UVB doses essential for vitamin D3 photoproduction. Upon irradiation, 24‐hydroxylase (CYP24) mRNA is induced in both cell types pretreated with the sterol Δ7‐reductase inhibitor BM15766 whereby the 7‐dehydrocholesterol (7‐DHC) content was increased. Transfection studies in CaCo‐2 cells with a vitamin D response element‐containing construct revealed the involvement of the VDR in this UVB‐dependent CYP24 induction. The CYP24 inducing activity in BM15766‐pretreated UVB‐irradiated CaCo‐2 cells and THP‐1 macrophages was identified as 1,25(OH)2D3 by combined high‐performance liquid chromatography radioimmunoassay. Addition of vitamin D binding protein to the CaCo‐2 cells attenuated UVB‐induced CYP24 induction suggesting the possibility of a paracrine or autocrine role for the photoproduced 1,25(OH)2D3. In conclusion, preconfluent CaCo‐2 cells and THP‐1 macrophages are able to induce vitamin D activity upon UVB irradiation and hence combine all parts of the vitamin D photoendocrine system, a characteristic which is therefore not keratinocyte specific. J. Cell. Biochem. © 2006 Wiley‐Liss, Inc.
Alteration in cellular functions in mouse macrophages after exposure to 50 Hz magnetic fields
Authors: Frahm Jana , Lantow Magaréta , Lupke Madeleine , Weiss Dieter G. , Simkó Myrtill
Published: April 2006

The aim of the present study is to investigate whether extremely low frequency electromagnetic fields (ELF‐EMF) affect certain cellular functions and immunologic parameters of mouse macrophages. In this study, the influence of 50 Hz magnetic fields (MF) at 1.0 mT was investigated on the phagocytic activity and on the interleukin‐1β (IL‐1β) production in differentiated macrophages. MF‐exposure led to an increased phagocytic activity after 45 min, shown as a 1.6‐fold increased uptake of latex beads in MF‐exposed cells compared to controls. We also demonstrate an increased IL‐1β release in macrophages after 24 h exposure (1.0 mT MF). Time‐dependent IL‐1β formation was significantly increased already after 4 h and reached a maximum of 12.3‐fold increase after 24 h compared to controls. Another aspect of this study was to examine the genotoxic capacity of 1.0 mT MF by analyzing the micronucleus (MN) formation in long‐term (12, 24, and 48 h) exposed macrophages. Our data show no significant differences in MN formation or irregular mitotic activities in exposed cells. Furthermore, the effects of different flux densities (ranging from 0.05 up to 1.0 mT for 45 min) of 50 Hz MF was tested on free radical formation as an endpoint of cell activation in mouse macrophage precursor cells. All tested flux densities significantly stimulated the formation of free radicals. Here, we demonstrate the capacity of ELF‐EMF to stimulate physiological cell functions in mouse macrophages shown by the significantly elevated phagocytic activity, free radical release, and IL‐1β production suggesting the cell activation capacity of ELF‐EMF in the absence of any genotoxic effects. J. Cell. Biochem. © 2006 Wiley‐Liss, Inc.
Stable formation of mutated p53 multimers in a Chinese hamster cell line causes defective p53 nuclear localization and abrogates its residual function
Authors: Ottaggio Laura , Campomenosi Paola , Fronza Gilberto , Menichini Paola , Miele Mariangela , Moro Francesca , Viaggi Silvia , Zunino Annalisa , Abbondandolo Angelo
Published: April 2006

We have previously described a methotrexate‐resistant cell line (MTX M) characterized by amplified dihydrofolate reductase (DHFR) genes, cytoplasmic p53 localization, and p53 stable tetramers. To investigate the p53 functionality in MTX M, the effect of chemical/physical agents was studied. In MTX M cells, DNA damage did not induce p53 or mdm‐2 protein, while in the parental V79 cells, a residual p53 activity was found. cDNA sequencing showed that V79 and MTX M cells share the same mutations, indicating that the complete loss of p53 function in MTX M cells was due to cytoplasmic sequestration of a mutated p53 with residual activity. In Chinese hamster, both p53 and DHFR genes map on short arm of chromosome 2 suggesting that p53 itself might be amplified. However, fluorescence in situ hybridization with a hamster p53 probe showed only a single signal. Thus, the presence of p53 stable tetramers in MTX M cells, although correlated with DNA amplification, could not be the consequence of either p53 or DHFR gene amplification. Expression of a C‐terminal human p53 peptide does not induce p53 nuclear accumulation, indicating that the cytoplasmic localization is due to a mechanism different from that already described in cancer cell lines. Treatments with Sodium Butyrate induced β‐tubulin polymerization, but did not apparently organize a normal microtubule network, which is shown to be important for the p53 localization. Our data indicated that in MTX M cells, p53 is sequestered in the cytoplasm by a novel mechanism that abrogates p53 residual function. J. Cell. Biochem. © 2006 Wiley‐Liss, Inc.
Retinoids directly activate the collagen X promoter in prehypertrophic chondrocytes through a distal retinoic acid response element
Authors: Cohen Arthur J. , Lassová Luisa , Golden Eleanor B. , Niu Zeling , Adams Sherrill L.
Published: April 2006

Retinoids are essential for the terminal differentiation of chondrocytes during endochondral bone formation. This maturation process is characterized by increased cell size, expression of a unique extracellular matrix protein, collagen X, and eventually by mineralization of the matrix. Retinoids stimulate chondrocyte maturation in cultured cells and experimental animals, as well as in clinical studies of synthetic retinoids; furthermore, retinoid antagonists prevent chondrocyte maturation in vivo. However, the mechanisms by which retinoids regulate this process are poorly understood. We and others showed previously that retinoic acid (RA) stimulates expression of genes encoding bone morphogenetic proteins (BMPs), suggesting that retinoid effects on chondrocyte maturation may be indirect. However, we now show that RA also directly stimulates transcription of the collagen X gene promoter. We have identified three RA response element (RARE) half‐sites in the promoter, located 2,600 nucleotides upstream from the transcription start site. These three half‐sites function as two overlapping RAREs that share the middle half‐site. Ablation of the middle half‐site destroys both elements, abolishing RA receptor (RAR) binding and drastically decreasing RA stimulation of transcription. Ablation of each of the other two half‐sites destroys only one RARE, resulting in an intermediate level of RAR binding and transcriptional stimulation. These results, together with our previously published data, indicate that retinoids stimulate collagen X transcription both directly, through activation of RARs, and indirectly, through increased BMP production. J. Cell. Biochem. © 2006 Wiley‐Liss, Inc.
Hamiltonian graphs involving neighborhood unions
Authors: Chen Guantao , Shreve Warren E. , Wei Bing
Published: April 2006

Dirac proved that a graph G is hamiltonian if the minimum degree $\delta(G) \geq n/2$, where n is the order of G. Let G be a graph and $A \subseteq V(G)$. The neighborhood of A is $N(A)=\{ b: ab \in E(G)$ for some $a \in A\}$. For any positive integer k, we show that every (2k − 1)‐connected graph of order n ≥ 16k3 is hamiltonian if |N(A)| ≥ n/2 for every independent vertex set A of k vertices. The result contains a few known results as special cases. The case of k = 1 is the classic result of Dirac when n is large and the case of k = 2 is a result of Broersma, Van den Heuvel, and Veldman when n is large. For general k, this result improves a result of Chen and Liu. The lower bound 2k − 1 on connectivity is best possible in general while the lower bound 16k3 for n is conjectured to be unnecessary. © 2006 Wiley Periodicals, Inc. J Graph Theory 53: 83–100, 2006
Pandemic influenza and the hospitalist: Apocalypse when?
Authors: Pile James C. , Gordon Steven M.
Published: April 2006

Beginning with a cluster of human cases in Hong Kong in 1997, avian influenza (H5N1) has spread progressively through, and beyond, Asia in poultry and other birds; and has resulted in sporadic cases of human disease associated with high mortality. The potential for H5N1 influenza to cause a pandemic of human disease continues to be the subject of intense scrutiny by both the media and the scientific community. While the likelihood of such a prospect is uncertain, the inevitability of future pandemics of influenza is clear. Planning for the eventuality of a virulent influenza pandemic at the local, national and global level is critical to limiting the mortality and morbidity of such an occurrence. Hospitalists have a key role to play in institutional efforts to prepare for a influenza pandemic, and should be aware of lessons that my be applied from both the response to Hurricane Katrina, as well as the severe acute respiratory syndrome (SARS) epidemic. Journal of Hospital Medicine 2006;1:118–123. © 2006 Society of Hospital Medicine
Characterization of metabolites of tanshinone IIA in rats by liquid chromatography/tandem mass spectrometry
Authors: Li Peng , Wang Guang‐Ji , Li Jing , Hao Hai‐Ping , Zheng Chao‐Nan
Published: April 2006

The metabolism of tanshinone IIA was studied in rats after a single‐dose intravenous administration. In the present study, 12 metabolites of tanshinone IIA were identified in rat bile, urine and feces with two LC gradients using LC‐MS/MS. Seven phase I metabolites and five phase II metabolites of tanshinone IIA were characterized and their molecular structures proposed on the basis of the characteristics of their precursor ions, product ions and chromatographic retention time. The seven phase I metabolites were formed, through two main metabolic routes, which were hydroxylation and dehydrogenation metabolism. M1, M4, M5 and M6 were supposedly tanshinone IIB, hydroxytanshinone IIA, przewaquinone A and dehydrotanshinone IIA, respectively, by comparing their HPLC retention times and mass spectral patterns with those of the standard compounds. The five phase II metabolites identified in this research were all glucuronide conjugates, all of which showed a neutral loss of 176 Da. M9 and M12 were more abundant than other identified metabolites in the bile, which was the main excretion path of tanshinone IIA and the metabolites. M12 was the main metabolite of tanshinone IIA. M9 and M12 were proposed to be the glucuronide conjugates of two different semiquinones and these semiquinones were the hydrogenation products of dehydrotanshinone IIA and tanshinone IIA, respectively. This hydrogenized reaction may be catalyzed by the NAD(P)H: quinone acceptor oxidoreductase (NQO). The biotransformation pathways of tanshinone IIA were proposed on the basis of this research. Copyright © 2006 John Wiley & Sons, Ltd.
Quantification of fudosteine in human plasma by high‐performance liquid chromatography‐electrospray ionization mass spectrometry employing precolumn derivatization with 9‐fluorenylmethyl chloroformate
Authors: Xu Fengguo , Zhang Zunjian , Jiao Haoyan , Tian Yuan , Zhang Beibei , Chen Yun
Published: April 2006

This paper describes a novel method for the sensitive and selective determination of fudosteine in human plasma. The method involves a derivatization step with 9‐fluorenylmethyl chloroformate (FMOC‐Cl) in borate buffer and detection based on high‐performance liquid chromatography‐electrospray ionization mass spectrometry (LC/ESI/MS). After acetonitrile‐induced protein precipitation of plasma samples, fudosteine was derivatized with FMOC‐Cl, then extracted by ethyl acetate, evaporated, reconstituted and injected using an LC/ESI/MS instrument. Separation was achieved using an ODS column and isocratic elution. Excellent linearity was obtained for the entire calibration range from 0.05 to 20 µg/ml. Validation assays of the lower limit of quantification (LLOQ) as well as for the intra‐ and inter‐batch precision and accuracy met the international acceptance criteria for bioanalytical method validation. Using the developed analytical method, fudosteine could be detected for the first time in human plasma with a low limit of detection (LLOD) of 0.03 µg/ml. The proposed method has been successfully applied to study the pharmacokinetics of fudosteine in healthy Chinese volunteers after single and multiple oral administration. Copyright © 2006 John Wiley & Sons, Ltd.
Bone grafts prepared with selective cell retention technology heal canine segmental defects as effectively as autograft
Authors: Brodke Darrel , Pedrozo Hugo A. , Kapur Terri A. , Attawia Mohamed , Kraus Karl H. , Holy Chantal E. , Kadiyala Sudha , Bruder Scott P.
Published: April 2006

Using a canine critical‐size segmental defect model, a two‐phased study was undertaken to evaluate the healing efficacy of demineralized bone and cancellous chips (DBM‐CC) enriched with osteoprogenitor cells using a Selective Cell Retention (SCR) technology. The goals of this study were: 1) to determine the bone‐healing efficacy of SCR‐enriched grafts versus autograft, and 2) to assess the value of clotting SCR‐enriched grafts with platelet‐rich plasma (PRP). Thirty dogs were included in Phase I: 18 dogs were treated with an SCR‐enriched DBM‐CC graft clotted with autologous bone marrow, and were compared to 12 autograft controls. In Phase II, 24 animals were divided into 4 groups of 6 animals, each treated with a different bone graft material: 1) iliac crest autograft, 2) DBM‐CC alone, 3) DBM‐CC saturated with marrow, and 4) SCR‐enriched DBM‐CC clotted with PRP. All grafts were placed unilaterally in a 21‐mm long osteoperiosteal femoral, instrumented, critical‐size defect. Radiographs were obtained for all animals postoperatively and every 4–16 weeks; animals were then sacrificed. All femurs were prepared for histology. Femurs in the Phase II study were also analyzed by micro‐CT. At 16 weeks, healing—defined by bridging bone across the defects—was observed in 50% of the DBM‐CC alone group and 67% of the DBM‐CC saturated with marrow group; 100% of the autograft and SCR‐enriched DBM‐CC groups were healed. Histologically, grafts clotted with PRP showed more mature bone than those implanted with autologous bone, which in turn were similar to those implanted with bone marrow clotted SCR‐enriched grafts. These results demonstrated that: 1) SCR‐enriched DBM‐CC was equivalent to autograft to repair critical‐size defects, and 2) while not statistically significant, PRP may have accelerated bone maturation when used to clot osteoprogenitor‐enriched DBM‐CC grafts—as compared to cell‐enriched, DBM‐CC grafts without PRP—in large animal models. © 2006 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res
Effect of shoulder tightness on glenohumeral translation, scapular kinematics, and scapulohumeral rhythm in subjects with stiff shoulders
Authors: Lin Jiu‐jenq , Lim Hyun K. , Yang Jing‐Lan
Published: April 2006

Shoulder tightness may cause altered kinematics and lead to development of subacromial impingement, tendinitis, and degenerative changes. In this investigation, the humeral head translations, scapular kinematics, and scapulohumeral rhythm were determined with a three‐dimensional electromagnetic tracking device during arm elevations in six subjects with anterior shoulder tightness and in six subjects with posterior shoulder tightness to study the effects of anterior/posterior tightness on shoulder kinematics. Subjects with anterior tightness showed lower slopes in curves of glenohumeral elevation plotted against scapular upward rotation (scapulohumeral rhythm, 0.11 to 0.32; p = 0.021) and less posterior scapular tilt (2.9 to 7.5°; p = 0.002) during arm elevations when compared to the group with posterior tightness. The humeral head was positioned less posteriorly (2.2 to 3.4 mm; p = 0.004) and more superiorly (3.8 to 7.0 mm; p < 0.0005) during arm elevation in subjects with posterior tightness. The alternations in shoulder kinematics between subjects with anterior and posterior shoulder tightness may be relevant to the development of subacromial impingement, tendinitis, and degenerative changes as seen in subjects with stiff shoulders. © 2006 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res
Anticancer effects of zoledronic acid against human osteosarcoma cells
Authors: Kubista B. , Trieb K. , Sevelda F. , Toma C. , Arrich F. , Heffeter P. , Elbling L. , Sutterlüty H. , Scotlandi K. , Kotz R. , Micksche M. , Berger W.
Published: April 2006

Based on neoadjuvant chemotherapy, the prognosis of osteosarcoma patients has improved dramatically. However, due to therapy resistance in patient subgroups, the development of new treatment strategies is still of utmost importance. The aim of our study was to test the effects of the nitrogen‐containing bisphosphonate zoledronic acid (ZOL) on osteosarcoma cell lines (N = 9). Exposure to ZOL at low micromolar concentrations induced a dose‐ and time‐dependent block of DNA synthesis and cell cycle progression followed by microfilament breakdown and apoptosis induction. The ZOL‐induced cell cycle accumulation in S phase was accompanied by significant changes in the expression of cyclins and cyclin‐dependent kinase inhibitors with a prominent loss of cyclin E and D1. ZOL not only inhibited growth but also migration of osteosarcoma cells. The mevalonate pathway intermediary geranyl‐geraniol (GGOH) but not farnesol (FOH) significantly inhibited the anticancer effects of ZOL against osteosarcoma cells. Correspondingly, ZOL sensitivity correlated with the blockade of protein geranylgeranylation indicated by unprenylated Rap1. Overexpression of even high levels of P‐glycoprotein, as frequently present in therapy‐resistant osteosarcomas, did not impair the anticancer activity of ZOL. Summarizing, our data suggest that ZOL, which selectively accumulates in the bone, represents a promising agent to improve osteosarcoma therapy. © 2006 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res
How muscles recover from paresis and atrophy after intramuscular injection of botulinum toxin A: Study in juvenile rats
Authors: Shen Jian , Ma Jianjun , Lee Cassandra , Smith Beth P. , Smith Thomas L. , Tan Kim H. , Koman L. Andrew
Published: April 2006

Botulinum toxin A (BoNT‐A) is a potent biological toxin widely used for the management of skeletal muscle spasticity or dynamic joint contracture. Intramuscular injection of BoNT‐A causes muscle denervation, paresis, and atrophy. This clinical effect of botulinum toxin A lasts 3 to 6 months, and injected muscle eventually regains muscle mass and recovers muscle function. The goal of the present study was to characterize the molecular and cellular mechanisms leading to neuromuscular junction (NMJ) regeneration and skeletal muscle functional recovery after BoNT‐A injection. Fifty‐six 1‐month‐old Sprague‐Dawley rats were used. Botulinum toxin A was injected into the left gastrocnemius muscle at a dosage of 6 units/kg body weight. An equivalent volume of saline was injected into the right gastrocnemius muscle to serve as control. The gastrocnemius muscle samples were harvested from both hind limbs at 3 days, 7 days, 15 days, 30 days, 60 days, 90 days, 180 days, and 360 days after administration of toxin. In addition, the gastrocnemius muscles from 1‐month‐old rats with no injections were harvested to serve as uninjected control group. Muscle samples were processed and mRNA was extracted. Real‐time polymerase chain reaction (PCR) and gene microarray technology were used to identify key molecules involved in NMJ stabilization and muscle functional recovery. More than 28,000 rat genes were analyzed and approximately 9000 genes are expressed in the rat gastrocnemius muscle. Seven days following BoNT‐A injection, 105 genes were upregulated and 59 genes were downregulated. Key molecules involved in neuromuscular junction (NMJ) stabilization and muscle functional recovery were identified and their time course of gene expression following BoNT‐A injection were characterized. This animal study demonstrates that following intramuscular injection of BoNT‐A, there is a sequence of cellular events that eventually leads to NMJ stabilization, remodeling, and myogenesis and muscle functional recovery. This recovery process is divided into two stages (aneural and neural) and that the IGF‐1 signaling pathway play a central role in the process. © 2006 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res
Impact of model for end-stage liver disease (MELD) scoring system on pathological findings at and after liver transplantation
Authors: Khettry Urmila , Azabdaftari Gissou , Simpson Mary Ann , Pomfret Elizabeth A. , Pomposelli James J. , Lewis David W. , Jenkins Roger L. , Gordon Fredric D.
Published: April 2006

The Model for End-Stage Liver Disease (MELD) scoring system, a validated objective liver disease severity scale, was adopted in February 2002 to allocate cadaveric organs for liver transplantation (LT). To improve transplantability before succumbing to advanced disease, patients with low-stage hepatocellular carcinoma (HCC) are given extra points in this system commensurate with their predicted mortality. Our aims were to determine 1) any change in the pathological findings at LT following the implementation of this system and 2) the impact of scoring advantage given to early-stage HCC. Clinicopathologic findings were compared before (pre-MELD, n = 87) and after (MELD, n = 58) the introduction of the MELD system. The findings in the pre-MELD vs. MELD groups were as follows: HCC, 27.5% vs. 48.3% (P = 0.001); portal vein thrombosis (PVT), 13.7% vs. 25.9% (P = 0.08); cholestasis, 16.1% vs. 32.7% (P = 0.026); inflammation grade of 2 or more, 43.7% vs. 48.3% (P = not significant); hepatitis C (HCV), 45.9% vs. 51.7% (P = not significant); HCV with lymphoid aggregates, 25% vs. 60% (P = 0.003); HCV with hyperplastic hilar nodes, 15.0% vs. 36.6% (P = 0.001); and post-LT HCC recurrence, 4.1% vs. 3.4% (P = not significant). Non-HCC-related findings were further compared in the 2 subgroups of pre-MELD (n = 57) and MELD (n = 31) after exclusion of HCC and fulminant hepatic failure (FHF) cases, and only cholestasis was significantly increased in the subgroup MELD. In conclusion, increased incidence of native liver cholestasis in the MELD era may be the histologic correlate of clinically severe liver disease. The scoring advantage given to low-stage HCC did result in a significantly increased incidence of HCC in the MELD group, but it did not adversely affect the post-LT recurrence rate.
Liver Transpl 12:958–965, 2006.

© 2006 AASLD.
Impact of model for end-stage liver disease (MELD) score on prognosis after hepatectomy for hepatocellular carcinoma on cirrhosis
Authors: Cucchetti Alessandro , Ercolani Giorgio , Vivarelli Marco , Cescon Matteo , Ravaioli Matteo , La Barba Giuliano , Zanello Matteo , Grazi Gian Luca , Pinna Antonio Daniele
Published: April 2006

The objective of this study was to predict postoperative liver failure and morbidity after hepatectomy for hepatocellular carcinoma (HCC) with cirrhosis. The model for end-stage liver disease (MELD) score is currently accepted as a disease severity index of cirrhotic patients awaiting liver transplantation; however, its impact on prognosis after resection of HCC on cirrhosis has never been investigated. One hundred fifty-four cirrhotic patients resected in a tertiary care setting for HCC were retrospectively analyzed. For each patient, the MELD score was calculated and related to postoperative liver failure and complications (morbidity). Hospital stay and 1-year survival was also investigated. MELD accuracy in predicting postoperative liver failure and morbidity of cirrhotic patients was assessed using receiver operating characteristic (ROC) analysis. Eleven patients (7.1%) experienced postoperative liver failure leading to death or transplantation. ROC analysis identified cirrhotic patients with a MELD score equal to or above 11 at high risk for postoperative liver failure (area under the curve [AUC] = 0.92, 95% confidence interval [CI] = 0.87–0.96; sensitivity = 82%; specificity = 89%). Forty-six patients (29.9%) developed at least 1 postoperative complication: ROC analysis identified patients with a MELD score equal to or above 9 at major risk for postoperative complications (AUC = 0.85, 95% CI = 0.78–0.89; sensitivity = 87%; specificity = 63%). Cirrhotic patients with MELD score below 9 had no postoperative liver failure and low morbidity (8.1%). In conclusion, the MELD score can accurately predict postoperative liver failure and morbidity of cirrhotic patients referred for resection of HCC and should be used to select the best candidates for hepatectomy.
Liver Transpl 12:966–971, 2006.

© 2006 AASLD.
Cover Picture: Macromol. Biosci. 4/2006
Authors: Min Byung‐Moo , Jeong Lim , Lee Kuen Yong , Park Won Ho
Published: April 2006

Cover: Silk fibroin nanofibers with decreased solubility against water, increased mechanical strength and good cellular compatibility could be obtained upon water vapor treatment. A scanning electron microscopic picture of the water vapor treated fibers is shown on the cover. Further details can be found in the Full Paper by B.‐M. Min, L. Jeong, K. Y. Lee,* and W. H. Park* on page 285.
Cover Picture: Macromol. Mater. Eng. 4/2006
Authors: Tsuji Hideto , Takai Hiroki , Fukuda Norio , Takikawa Hirofumi
Published: April 2006

Cover: The picture on the cover shows polarized photomicrographs of poly(L‐lactic acid) (PLLA) crystallized from the melt in the presence of poly(D‐lactic acid) (PDLA) fullerene C60, montmorillonite, and talc. These additives dramatically increased the spherulite number of PLLA, meaning that these additives can act as promising nucleating agents. Further details can be found in the article by H. Tsuji,* H. Takai, N. Fukuda, and H. Takikawa on page 325.
Dense subspaces of quasinormable spaces
Authors: Bonet José , Dierolf Susanne , Aye Aye Khin
Published: April 2006

Dense linear subspaces of quasinormable Fréchet spaces need not be quasinormable, as an example due to J. Bonet and S. Dierolf proved. A characterization of the quasinormability of dense linear subspaces of quasinormable locally convex spaces and several consequences are given. Moreover, an example of a dense linear subspace of a countable direct sum of Banach spaces, which is not quasinormable, is provided. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Koplienko–Neidhardt trace formula for pairs of contraction operators and pairs of maximal dissipative operators
Authors: Marcantognini S. A. M. , Morán M. D.
Published: April 2006

We present a generalization of Koplienko–Neidhardt trace formula for pairs of Hilbert space operators (T , V ) with T contractive and V unitary such that T – V is a Hilbert–Schmidt operator. We extend the result to pairs of contractions and then, via Cayley transform, to pairs of maximal dissipative operators. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Topological rigidity theorems for open Riemannian manifolds
Authors: Wang Qiaoling , Xia Changyu
Published: April 2006

In this article, we study topology of complete non‐compact Riemannian manifolds. We show that a complete open manifold with quadratic curvature decay is diffeomorphic to a Euclidean n ‐space ℝn if it contains enough rays starting from the base point. We also show that a complete non‐compact n ‐dimensional Riemannian manifold M with nonnegative Ricci curvature and quadratic curvature decay is diffeomorphic to ℝn if the volumes of geodesic balls in M grow properly. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Linear and Nonlinear Viscoelasticity of a Model Unentangled Polymer Melt: Molecular Dynamics and Rouse Modes Analysis
Authors: Vladkov Mihail , Barrat Jean‐Louis
Published: April 2006

Summary: Using molecular dynamics simulations, we determine the linear and nonlinear viscoelastic properties of a model polymer melt in the unentangled regime. Several approaches are compared for the computation of linear moduli and viscosity, including Green‐Kubo and nonequilibrium molecular dynamics (NEMD). An alternative approach, based on the use of the Rouse modes, is also discussed. This approach could be used to assess local viscoelastic properties in inhomogeneous systems. We also focus on the contributions of different interactions to the viscoelastic moduli and explain the microscopic mechanisms involved in the mechanical response of the melt to external solicitation.

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Sleep complaints and their relation with drug treatment in patients suffering from Parkinson's disease
Authors: Gómez‐Esteban Juan Carlos , Zarranz Juan Jose , Lezcano Elena , Velasco Fernando , Ciordia Roberto , Rouco Idoia , Losada Jose , Bilbao Iker
Published: April 2006

The aim of this research was to quantify sleep problems in patients suffering from Parkinson's disease by means of the new Parkinson's Disease Sleep Scale (PDSS) and to correlate such problems with the possible influence of current drug treatment. A total of 70 patients (36 men and 34 women) with a diagnosis of Parkinson's disease were enrolled. Their mean age was 69.7 ± 8.2 years, and duration of disease was 7.4 ± 4.8 years. All patients completed the PDSS and the Unified Parkinson's Disease Rating Scale (UPDRS Parts I–IV). Drug consumption and doses were registered. The mean score on the PDSS scale was 109.23 ± 19.75 and on the UPDRS III scale was 25.24 ± 11.35. The lowest scores were obtained in Item 3 (sleep fragmentation): 5.53 (2.46); and in Item 8 (nocturia): 5.75 (2.91). There was a weak correlation between the PDSS and UPDRS III (cc = −0.355,P= 0.003), PDSS and UPDRS I (cc = −0.272,P= 0.02), and PDSS and UPDRS IV (cc = −0.416,P< 0.001). Motor conditions, mental state, and drug complications influence sleep quality. Although this effect was significant, it was not of a great magnitude. Dopaminergic drugs did not increase daytime sleepiness. As a whole, sleep quality in patients who took dopaminergic agonists did not differ from that of patients who took levodopa in monotherapy. © 2006 Movement Disorder Society
Isolated high‐frequency jaw tremor relieved by botulinum toxin injections
Authors: Gonzalez‐Alegre Pedro , Kelkar Praful , Rodnitzky Robert L.
Published: April 2006

Jaw tremor can be seen as a component of various neurological disorders such as essential tremor, Parkinson's disease, dystonia, branchial myoclonus, hereditary geniospasm, task‐specific tremor, and Whipple's disease, as well as in normal situations such as shivering, and subclinical physiological jaw tremor. In most of these conditions, the jaw tremor is usually associated with tremor or other abnormal involuntary movements affecting additional body parts, and its frequency is lower than 12 Hz. Schrag and colleagues reported a patient with a high‐frequency idiopathic jaw tremor, and they speculated it could be related to orthostatic tremor affecting the masseter muscles. We encountered a similar patient with intermittent rapid focal jaw tremor that was successfully treated with botulinum toxin injections to the masseters. © 2006 Movement Disorder Society
Prevalence of dystonia in Akita prefecture in Northern Japan
Authors: Sugawara Masashiro , Watanabe Sumio , Toyoshima Itaru
Published: April 2006

We investigated the prevalence of dystonia in Akita Prefecture (population was 1,166,967 as of 1 November 2004). The prevalence of primary generalized and focal dystonia is estimated to be 0.68 and 14.4 per 100,000 persons, respectively. Blepharospasm is the most common primary dystonia in this area. © 2006 Movement Disorder Society
Product‐oriented flavor research: Learnings from the past, visions for the future
Authors: Krammer Gerhard E. , Weckerle Bernhard , Brennecke Stefan , Weber Berthold , Kindel Günter , Ley Jakob , Hilmer Jens‐Michael , Reinders Gerald , Stöckigt Detlef , Hammerschmidt Franz Josef , Ott Frank , Gatfield Ian , Schmidt Claus Oliver , Bertram Heinz‐Jürgen
Published: April 2006

In the past flavor research and the development of new flavorings were constantly driven by the interaction of flavor analysis, structure elucidation, and chemical synthesis accompanied by sensory. Highly potent flavor compounds were identified in numerous food products and helped to establish a powerful toolbox for flavorists. Nowadays we experience the merging of various scientific disciplines, for example medicine, biology, chemistry, and various technologies in the field of flavor research, which shows direct impact on our understanding of flavors. At the same time modern life has profoundly changed our eating habits. This situation generates new challenges for product development teams, which represent all facets of technologies. This paper will illustrate different examples for the evolution of product‐oriented flavor research and future trends.
Anti‐human immunodeficiency virus activity of 3,4,5‐tricaffeoylquinic acid in cultured cells of lettuce leaves
Authors: Tamura Hirotoshi , Akioka Takashi , Ueno Koichi , Chujyo Takeshi , Okazaki Katsu‐ichiro , King Peter J. , Robinson W. Edward
Published: April 2006

3,4,5–Tricaffeoylquinic acid (TCQA) that is not found in intact plant of lettuce leaves was isolated from the cultured cells. The intact plant produced chicoric acid (dicaffeoyl tartaric acid: L‐CCA) as well as chlorogenic acid (3‐caffeoylquinic acid: 3‐CQA) as the major metabolites. After subculturing of the cells for 40 days, the amount of 3,4,5‐TCQA reached to 0.14 mg/g fresh weight. The inhibitory effect of 3,4,5‐TCQA for human immunodeficiency virus (HIV) Type 1 integrase was assayed. Anti‐HIV activity using HIV and MT‐2 cells was 1.15 μM and IC50 against HIV integrase was 0.063 μM whereas cell toxicity of this chemical was expressed as 5% death of all living cells to be 18.4 μM. The HIV inhibitory effect of 3,4,5‐TCQA was the highest in values among L‐CCA, and other dicaffeoylquinic acids. This data will provide a new possibility for creating a new drug design for HIV.
Biological activities of malvidin, a red wine anthocyanidin
Authors: Fritz Jessica , Kern Melanie , Pahlke Gudrun , Vatter Sandra , Marko Doris
Published: April 2006

Malvidin (mv) has been identified as a potential inhibitor of 3′,5′‐cyclic adenosine monophosphate (cAMP) phosphodiesterases (PDE). This study was to investigate if, as a possible consequence of intracellular PDE inhibition, the activity of the mitogen‐activated protein kinase (MAPK) cascade is affected by mv treatment. At a concentration of 5 μM of mv a significant decrease of phosphorylated ERK1 and ERK2 (ERK, extracellular regulated kinase) in HT29 cells was observed. However, an increase in substance concentration led to a substantial recurrence of the phosphorylated enzymes. Cell cycle analysis underlined that indeed G1‐relevant targets are only marginally affected by mv. The recurrence of phosphorylated ERK1/2 and the lack of effectiveness on the G1‐passage up to 100 μM indicated that the inhibition of cAMP‐specific PDEs is of minor relevance for the growth‐inhibitory properties of mv in HT29 cells. In contrast, the release of cells, synchronised in the G2/M‐phase of the cell cycle by nocodazole treatment, was effectively blocked in the presence of 1 μM mv. These results suggest that mv interferes with cellular targets relevant for G2/M‐progression which have not been identified so far.