bluuebunny/crossref_metadata_2025_split huggingface dataset:
Molecular diffusion in tissue‐engineered cartilage constructs: Effects of scaffold material, time, and culture conditions
Authors: Leddy Holly A. , Awad Hani A. , Guilak Farshid 
Published: April 2004

AbstractDiffusion is likely to be the primary mechanism for macromolecular transport in tissue‐engineered cartilage, and providing an adequate nutrient supply via diffusion may be necessary for cell proliferation and extracellular matrix production. The goal of this study was to measure the diffusivity of tissue‐engineered cartilage constructs as a function of scaffold material, culture conditions, and time in culture. Diffusion coefficients of four different‐sized fluorescent dextrans were measured by fluorescence recovery after photobleaching in tissue‐engineered cartilage constructs seeded with human adipose‐derived stem cells or acellular constructs on scaffolds of alginate, agarose, gelatin, or fibrin that were cultured for 1 or 28 days in either chondrogenic or control conditions. Diffusivities in the constructs were much greater than those of native cartilage. The diffusivity of acellular constructs increased 62% from Day 1 to Day 28, whereas diffusivity of cellular constructs decreased 42% and 27% in chondrogenic and control cultures, respectively. The decrease in diffusivity in cellular constructs is likely due to new matrix synthesis, which may be enhanced with chondrogenic media, and matrix contraction by the cells in the fibrin and gelatin scaffolds. The increase in diffusivity in the acellular constructs is probably due to scaffold degradation and swelling. © 2004 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 70B: 397–406, 2004
Development and testing of a general amber force field
Authors: Wang Junmei , Wolf Romain M. , Caldwell James W. , Kollman Peter A. , Case David A. 
Published: April 2004

AbstractWe describe here a general Amber force field (GAFF) for organic molecules. GAFF is designed to be compatible with existing Amber force fields for proteins and nucleic acids, and has parameters for most organic and pharmaceutical molecules that are composed of H, C, N, O, S, P, and halogens. It uses a simple functional form and a limited number of atom types, but incorporates both empirical and heuristic models to estimate force constants and partial atomic charges. The performance of GAFF in test cases is encouraging. In test I, 74 crystallographic structures were compared to GAFF minimized structures, with a root‐mean‐square displacement of 0.26 Å, which is comparable to that of the Tripos 5.2 force field (0.25 Å) and better than those of MMFF 94 and CHARMm (0.47 and 0.44 Å, respectively). In test II, gas phase minimizations were performed on 22 nucleic acid base pairs, and the minimized structures and intermolecular energies were compared to MP2/6‐31G* results. The RMS of displacements and relative energies were 0.25 Å and 1.2 kcal/mol, respectively. These data are comparable to results from Parm99/RESP (0.16 Å and 1.18 kcal/mol, respectively), which were parameterized to these base pairs. Test III looked at the relative energies of 71 conformational pairs that were used in development of the Parm99 force field. The RMS error in relative energies (compared to experiment) is about 0.5 kcal/mol. GAFF can be applied to wide range of molecules in an automatic fashion, making it suitable for rational drug design and database searching. © 2004 Wiley Periodicals, Inc. J Comput Chem 25: 1157–1174, 2004
Hypoxia suppresses runx2 independent of modeled microgravity
Authors: Ontiveros Christopher , Irwin Regina , Wiseman Robert W. , McCabe Laura R. 
Published: April 2004

AbstractBone loss is a consequence of skeletal unloading as seen in bed rest and space flight. Unloading decreases oxygenation and osteoblast differentiation/function in bone. Previously we demonstrated that simulation of unloading in vitro, by culturing differentiating mouse osteoblasts in a horizontal rotating wall vessel (RWV), results in suppressed expression of runx2, a master transcriptional regulator of osteoblast differentiation. However, the RWV is able to reproduce in a controlled fashion at least two aspects of disuse that are directly linked, model microgravity and hypoxia. Hypoxia in the RWV is indicated by reduced medium oxygen tension and increased expression of GAPDH and VEGF. To uncouple the role of model microgravity from hypoxia in suppressed runx2 expression, we cultured osteoblasts under modeled microgravity (oxygenated, horizontal RWV rotation), hypoxia (vertical RWV rotation), or both conditions (horizontal RWV rotation). The expression, DNA binding activity and promoter activity of runx2, was suppressed under hypoxic but not normoxic modeled microgravity RWV conditions. Consistent with a role for hypoxia in suppression of runx2, direct exposure to hypoxia alone is sufficient to suppress runx2 expression in osteoblasts grown in standard tissue culture plates. Taken together, our findings indicate that hypoxia associated with skeletal unloading could be major suppressor of runx2 expression leading to suppressed osteoblast differentiation and bone formation. © 2004 Wiley‐Liss, Inc.
The role of substance P in inflammatory disease
Authors: O'Connor Terence M. , O'Connell Joseph , O'Brien Darren I. , Goode Triona , Bredin Charles P. , Shanahan Fergus 
Published: April 2004

AbstractThe diffuse neuroendocrine system consists of specialised endocrine cells and peptidergic nerves and is present in all organs of the body. Substance P (SP) is secreted by nerves and inflammatory cells such as macrophages, eosinophils, lymphocytes, and dendritic cells and acts by binding to the neurokinin‐1 receptor (NK‐1R). SP has proinflammatory effects in immune and epithelial cells and participates in inflammatory diseases of the respiratory, gastrointestinal, and musculoskeletal systems. Many substances induce neuropeptide release from sensory nerves in the lung, including allergen, histamine, prostaglandins, and leukotrienes. Patients with asthma are hyperresponsive to SP and NK‐1R expression is increased in their bronchi. Neurogenic inflammation also participates in virus‐associated respiratory infection, non‐productive cough, allergic rhinitis, and sarcoidosis. SP regulates smooth muscle contractility, epithelial ion transport, vascular permeability, and immune function in the gastrointestinal tract. Elevated levels of SP and upregulated NK‐1R expression have been reported in the rectum and colon of patients with inflammatory bowel disease (IBD), and correlate with disease activity. Increased levels of SP are found in the synovial fluid and serum of patients with rheumatoid arthritis (RA) and NK‐1R mRNA is upregulated in RA synoviocytes. Glucocorticoids may attenuate neurogenic inflammation by decreasing NK‐1R expression in epithelial and inflammatory cells and increasing production of neutral endopeptidase (NEP), an enzyme that degrades SP. Preventing the proinflammatory effects of SP using tachykinin receptor antagonists may have therapeutic potential in inflammatory diseases such as asthma, sarcoidosis, chronic bronchitis, IBD, and RA. In this paper, we review the role that SP plays in inflammatory disease. J. Cell. Physiol. 201: 167–180, 2004. © 2004 Wiley‐Liss, Inc.
Epithelial mesenchymal transition is a characteristic of hyperplasias and tumors in mammary gland from MMTV‐Cripto‐1 transgenic mice
Authors: Strizzi Luigi , Bianco Caterina , Normanno Nicola , Seno Masaharu , Wechselberger Christian , Wallace‐Jones Brenda , Khan Nadia I. , Hirota Morihisa , Sun Youping , Sanicola Michele , Salomon David S. 
Published: April 2004

AbstractEpithelial‐mesenchymal transition (EMT) facilitates migration and invasion of epithelial tumor cells. Cripto‐1 (CR‐1), a member of the epidermal growth factor‐CFC protein family increases migration of cells in vitro. Here the expression of molecular markers and signaling molecules characteristic of EMT were assessed in mammary gland hyperplasias and tumors from mice expressing the human CR‐1 transgene by the MMTV promoter (MMTV‐CR‐1) and in mouse mammary epithelial cell line HC‐11 overexpressing CR‐1 (HC‐11/CR‐1). Western blot analysis showed decreased expression of E‐cadherin in MMTV‐CR‐1 tumors and in HC‐11/CR‐1 cells. The expression of N‐cadherin, vimentin, cyclin‐D1, and of the zinc‐finger transcription factor, snail, was increased in MMTV‐CR‐1 tumors. Increased snail mRNA was also found in HC‐11/CR‐1 cells. Expression of phosphorylated (P)‐c‐Src, P‐focal adhesion kinase (FAK), P‐Akt, P‐glycogen synthease kinase 3β (GSK‐3β), dephosphorylated (DP)‐β‐catenin, and various integrins such as, alpha 3, alpha v, beta 1, beta 3, and beta 4 was also increased in MMTV‐CR‐1 tumors. Immunohistochemistry showed positive staining for vimentin, N‐cadherin, cyclin‐D1, smooth muscle actin, fibronectin, snail, and β‐catenin in MMTV‐CR‐1 tumor sections. HC‐11/CR‐1 cells treated with the c‐Src inhibitor PP2 reduced the expression of P‐c‐Src and of P‐FAK, P‐Akt, P‐GSK‐3β, DP‐β‐catenin all known to be activated by c‐Src. Migration of HC‐11/CR‐1 cells was also reduced by PP2 treatment. These results suggest that CR‐1 may play a significant role in promoting the increased expression of markers and signaling molecules associated with EMT. © 2004 Wiley‐Liss, Inc.
Preparation and Thermosensitivity of Naturally Occurring Polypeptide Poly(γ‐glutamic acid) Derivatives Modified by Propyl Groups
Authors: Shimokuri Taiki , Kaneko Tatsuo , Serizawa Takeshi , Akashi Mitsuru 
Published: April 2004

AbstractSummary: Poly(γ‐glutamic acid) (γ‐PGA) is a biosynthetic polymer, and the carboxyl groups are able to undergo a chemical modification. In this study, poly(α‐propyl γ‐glutamate) (γ‐PGA propylate) was synthesized by the esterification of these carboxyl groups to yield a thermosensitive and biodegradable polymer. In aqueous solution, the γ‐PGA propylate can impart thermosensitivity by controlling the hydrophobic‐hydrophilic balance of the γ‐PGA polymeric chains.Temperature dependence of light transmittance of an aqueous solution of γ‐PGA and γ‐PGA propylate.imageTemperature dependence of light transmittance of an aqueous solution of γ‐PGA and γ‐PGA propylate.
Enhanced Biocompatibility in Biostable Poly(carbonate)urethane
Authors: Hsu Shan‐hui , Kao Yu‐Chih , Lin Zu‐Chang 
Published: April 2004

AbstractSummary: In this work, we synthesized two MDI‐based polyurethanes, including a poly(ether)urethane (PEU) and a poly(carbonate)urethane (PCU), by using different soft segments, poly(tetramethylene oxide) and poly(hexyl, ethyl)carbonate diol ($\overline M$ ∼ 2 000). We demonstrated that, in addition to the enhanced biostability of PCU over PEU, the biological performances of PCU in vitro were also improved in general. These included, better cellular attachment and proliferation, less platelet activation, as well as reduced monocyte activation. The unusual wide‐ranging enhancement in biocompatibility for PCU was believed to be related to the larger micro‐phase separation in PCU (∼25 nm) that caused distinct protein adsorption on the surface.The total number of adherent monocytes (nonactivated and activated) on the bare sample surfaces, albumin pre‐adsorbed sample surfaces, and fibrinogen pre‐adsorbed sample surfaces.imageThe total number of adherent monocytes (nonactivated and activated) on the bare sample surfaces, albumin pre‐adsorbed sample surfaces, and fibrinogen pre‐adsorbed sample surfaces.
Branched Azobenzene Side‐Chain Liquid‐Crystalline Copolymers Obtained by Self‐Condensing ATR Copolymerization
Authors: He Xiaohua , Yan Deyue 
Published: April 2004

AbstractSummary: The one step synthesis of a series of branched azobenzene side‐chain liquid‐crystalline copolymers by the self‐condensing vinyl copolymerization (SCVCP) of a methyl acrylic AB* inimer, 2‐(2‐bromoisobutyryloxy)ethyl methacrylate (BIEM), with the monomer 6‐(4‐methoxy‐azobenzene‐4′‐oxy)hexyl methacrylate (M), by atom transfer radical polymerization (ATRP) in the presence of CuBr/N,N,N′,N′,N″‐pentamethyldiethylenetriamine as a catalyst system, and in chlorobenzene solvent, is reported. The degree of branching (DB), and the molecular weights and polydispersities of the resultant polymers were determined by NMR spectroscopy and size exclusion chromatography, respectively. The phase behaviors of the branched copolymers were characterized by differential scanning calorimetry (DSC) and thermal polarized optical microscopy (POM). The degree of branching of the branched copolymers could be controlled by the comonomer ratio in the feed and influenced their liquid‐crystal properties. Liquid‐crystal properties were not exhibited when the comonomer ratio was low. Comonomer ratios greater than 8 gave polymers with a lower number of branches, which exhibited both a smectic and a nematic phase.A polarized optical micrograph of the smectic phase texture of a polymer synthesized here with a higher comonomer feed ratio (magnification × 400).imageA polarized optical micrograph of the smectic phase texture of a polymer synthesized here with a higher comonomer feed ratio (magnification × 400).
Pathway‐Dependent Melting in a Low‐Molecular‐Weight Polyethylene‐block‐Poly(ethylene oxide) Diblock Copolymer
Authors: Sun Lu , Liu Yuxiu , Zhu Lei , Hsiao Benjamin S. , Avila‐Orta Carlos A. 
Published: April 2004

AbstractSummary: In a low‐molecular‐weight polyethylene‐block‐poly(ethylene oxide) (PE‐b‐PEO) diblock copolymer, two pathway‐dependent melting processes were observed: Upon slow heating, the PE lamellar crystals melted at ≈97 °C into a disordered state. However, when the temperature rapidly jumped to above the melting point (e.g., 100 °C), the PE lamellar crystals transformed directly into an ordered lamellar melt, followed by an isothermal conversion into a disordered melt. This isothermal order‐to‐disorder transition was explained by superheating of the PE crystals using a G‐T diagram.A schematic G‐T diagram explaining the pathway‐dependent double melting for a crystalline polyethylene‐block‐poly(ethylene oxide) copolymer.imageA schematic G‐T diagram explaining the pathway‐dependent double melting for a crystalline polyethylene‐block‐poly(ethylene oxide) copolymer.
Profile of families with parkinsonism‐predominant spinocerebellar ataxia type 2 (SCA2)
Authors: Furtado Sarah , Payami Haydeh , Lockhart Paul J. , Hanson Melissa , Nutt John G. , Singleton Andrew A. , Singleton Amanda , Bower Jamel , Utti Ryan J. , Bird Thomas D. , de la Fuente‐Fernandez Raul , Tsuboi Yoshio , Klimek Mary L. , Suchowersky Oksana , Hardy John , Calne Donald B. , Wszolek Zbigniew K. , Farrer Matthew , Gwinn‐Hardy Katrina , Stoessl A. Jon 
Published: April 2004

AbstractSpinocerebellar ataxia type 2 (SCA2) has been recognized recently as an uncommon cause of parkinsonism, an alternate presentation to the typical cerebellar disorder. This research review summarizes the existing literature on parkinsonism‐predominant presentation SCA2 and presents new clinical cases of patients with this condition. Various phenotypes are noted in this subtype of SCA2, including parkinsonism indistinguishable from idiopathic Parkinson's disease (PD), parkinsonism plus ataxia, motor neuron disease, and postural tremor. In several kindreds with multiple affected family members, the SCA2 expansion segregated with disease; in addition, several single cases of parkinsonism with and without a family history are also described. The number of repeats in symptomatic patients ranged from 33 to 43. Interruption of the CAG repeat with CAA, CGG, or CCG was found in some individuals, possibly stabilizing the repeat structure and accounting for the relative stability of the repeat size across generations in some families; allele length is not necessarily indicative of trinucleotide repeat architecture. Positron emission tomography scanning in one family showed reduced fluorodopa uptake and normal to increased raclopride binding with a rostrocaudal gradient similar to that found in idiopathic PD. This review emphasizes the importance of testing for SCA2 in patients with parkinsonism and a family history of neurodegenerative disorders. Testing for SCA2 is also important in studies of inherited parkinsonism. © 2004 Movement Disorder Society
Unusual forehead tremor in a patient with essential tremor
Authors: Piboolnurak Panida , Pullman Seth L. , Louis Elan D. 
Published: April 2004

AbstractVoice and head (neck) tremor commonly occur in patients with essential tremor (ET), but involvement of cranial musculature is generally limited to these specific cranial structures, and action tremor of the forehead has not been reported. We describe a patient with ET who had forehead tremor. The tremor seemed to be task‐specific, and neurophysiological features suggested that the forehead tremor was dystonic. The presence of forehead tremor in a patient with ET probably indicates an additional pathophysiologic process. The explanation for the specificity of involvement of cranial musculature in ET is not known, but this clinical observation might help guide investigators who are interested in the underlying pathophysiology of this condition. © 2004 Movement Disorder Society
Clinicopathological investigation of vascular parkinsonism, including clinical criteria for diagnosis
Authors: Zijlmans Jan C.M. , Daniel Susan E. , Hughes Andrew J. , Révész Tamas , Lees Andrew J. 
Published: April 2004

AbstractVascular parkinsonism (VP) is difficult to diagnose with any degree of clinical certainty. We investigated the importance of macroscopic cerebral infarcts and pathological findings associated with microscopic “small vessel disease” (SVD) in the aetiology of VP. The severity of microscopic SVD pathology (perivascular pallor, gliosis, hyaline thickening, and enlargement of perivascular spaces) and the presence of macroscopically visible infarcts were assessed in 17 patients with parkinsonism and no pathological evidence of either Parkinson's disease or any histopathological condition known to be associated with a parkinsonian syndrome, and compared with age‐matched controls. Microscopic SVD pathology was significantly more severe in the parkinsonian brains. Most patients presented with bilateral bradykinesia and rigidity together with a gait disorder characterised predominantly by a shuffling gait. Four patients presented acutely with hemiparesis and then progressed to develop a parkinsonian syndrome. They could be distinguished from the remaining VP patients by the presence at autopsy of macroscopically visible lacunar infarcts in regions where contralateral thalamocortical drive might be reduced. The clinical features at presentation varied according to the speed of onset and the underlying vascular pathological state. New clinical criteria for a diagnosis of VP are proposed based on the clinicopathological findings of this study. © 2004 Movement Disorder Society
Development of Parkinson's disease in patients with blepharospasm
Authors: Micheli Federico , Scorticati María Clara , Folgar Silvia , Gatto Emilia 
Published: April 2004

AbstractThe liability to develop parkinsonian symptoms was evaluated in 105 outpatients with idiopathic blepharospasm (IBS; 54 cases) or IBS associated to oromandibular dystonia (Meige's syndrome; 51 cases) mean age 70.3 ± 9.6 years, and compared with an age‐ and sex‐matched population. Eleven patients developed Parkinson's disease in the blepharospasm group, whereas only 2 of 105 patients were affected in the control group. Our results suggest that patients with IBS either isolated or associated with oromandibular dystonia are more prone to develop parkinsonian symptoms. © 2004 Movement Disorder Society
Spinocerebellar ataxia type 2 with levodopa‐responsive parkinsonism culminating in motor neuron disease
Authors: Infante Jon , Berciano José , Volpini Victor , Corral Jordi , Polo José Miguel , Pascual Julio , Combarros Onofre 
Published: April 2004

AbstractWe describe an exceptional spinocerebellar ataxia type 2 (SCA2) phenotype combining cerebellar ataxia, levodopa‐responsive parkinsonism, and motor neuron symptoms. We conclude that motor neuron symptoms and signs may be a striking manifestation in SCA2, masking pre‐existing cerebellar and extrapyramidal semeiology. © 2004 Movement Disorder Society
Markedly asymmetrical parkinsonism as a leading feature of adult‐onset Huntington's disease
Authors: Wang Shih‐Ching , Lee‐Chen Guey‐Jen , Wang Cheng‐Kung , Chen Chiung‐Mei , Tang Lok‐Ming , Wu Yih‐Ru 
Published: April 2004

AbstractWe report on a 28‐year‐old man who presented with right hand tremor, bradykinesia, and rigidity of his right side extremities. Our case report emphasizes that markedly asymmetrical parkinsonism can be an initial presentation of adult‐onset Huntington's disease (HD), and different clinical presentations can be observed in members of an individual HD family with the same CAG repeat length. © 2004 Movement Disorder Society
Refined linkage to the RDP/DYT12 locus on 19q13.2 and evaluation of GRIK5 as a candidate gene
Authors: Kamm Christoph , Leung Joanne , Joseph Soni , Dobyns William B. , Brashear Alison , Breakefield Xandra O. , Ozelius Laurie J. 
Published: April 2004

AbstractBy examining two previously described families with rapid‐onset dystonia parkinsonism, we have identified a key recombination event that places the disease locus (DYT12) into a 5.9 cM interval flanked by markers D19S224 and D19S900. Evaluation of a positional candidate gene, the glutamate receptor subunit GRIK5, revealed no mutations. © 2004 Movement Disorder Society
Evaluation of the role of Nurr1 in a large sample of familial Parkinson's disease
Authors: Nichols William C. , Uniacke Sean K. , Pankratz Nathan , Reed Terry , Simon David K. , Halter Cheryl , Rudolph Alice , Shults Clifford W. , Conneally P. Michael , Foroud Tatiana 
Published: April 2004

AbstractParkinson's disease (PD) is a common neurodegenerative disorder in humans with wide variability in the age of disease onset. Although the disease has been thought previously to occur sporadically in most patients, there is increasing evidence of a genetic contribution to the disorder. Recently, a polymorphic variant within intron 6 of the Nurr1 gene was reported to be associated with sporadic and familial PD. In an effort to identify susceptibility genes for PD, we have collected 783 PD patients from 372 families and 397 healthy controls from 217 families. PD patients and healthy controls were genotyped for the intron 6 insertion polymorphism byBseRI restriction endonuclease digestion. No significant difference in either homozygosity or heterozygosity for the 7048G7049 (IVS6 1361 +16insG) polymorphism was detected in the PD patient cohort as compared with the panel of healthy controls. Moreover, direct sequencing of exon 1 of the Nurr1 gene in PD patients failed to detect either of the two recently reported Nurr1 mutations identified in a small subset of a PD patient cohort. Taken together, these data suggest that genetic alteration at the Nurr1 locus is not a significant risk factor for the development of Parkinson's disease in our large sample of familial PD patients. © 2004 Movement Disorder Society