980 research outputs found
Immunosuppression and gingival overgrowth : gene and protein expression profiles of collagen turnover in FK506-treated human gingival fibroblasts
No full textAIM: FK506 is an immunosuppressive agent that, unlike cyclosporin A (CsA), does not induce gingival overgrowth (GO). CsA-induced GO is caused by quantitative modifications of the extracellular matrix components, particularly collagen (COL). Up to now, clinical trials have only investigated FK506 in relation with GO, so we aimed at analysing the effect of FK506 on COL turnover using a molecular approach, to evaluate the expression of genes and proteins related to this process. MATERIALS AND METHODS: Human gingival fibroblasts were incubated with FK506 or its vehicle (VH) for 24, 48 and 72 h. COL type I (COL-I), matrix metalloproteinases (MMP)-1 and 2, tissue inhibitor of MMP (TIMP)-1 and transforming growth factor (TGF)-beta1 mRNA were assayed by Reverse transcriptase polymerase chain reaction; COL-I protein levels were determined by dot blot, MMP-1 and MMP-2 activity by zymography. RESULTS: Fibroblast proliferation decreased 48 and 72 h after treatment. COL-I gene and protein expression, TGF-beta1 and TIMP-1 mRNA levels were not significantly affected, whereas MMP-1 gene and protein expression and MMP-2 mRNA levels rose significantly in treated fibroblasts compared with VH. CONCLUSIONS: These findings suggest that increased MMP-1 gene and protein expression may be important for regulating COL-I homeostasis in the gingival connective compartment of FK506-immunosuppressed subjects. ((c) Blackwell Munksgaard, 2005.
Nitric oxide and tissue destruction
No full textCopyright © 2001 Munksgaard. All rights reserved. The definitive version is available at www.blackwell-synergy.comNitric oxide (NO) is a free radical which has complex roles in both health and disease. It is now recognized that NO is essential for a vast spectrum of intracellular and extracellular events in a wide variety of tissues. NO has also been implicated in the pathogenesis of numerous inflammatory and autoimmune diseases. In this review we consider the roles of NO generally and in particular the implications for periodontal diseases.HK Kendall, RI Marshall, PM Bartol
CRYSTAL-STRUCTURES OF A D-RESIDUE CONTAINING TETRAPEPTIDES .1. TERT-BOC-D-VALYL-ALANYL-LEUCYL-ALANYL METHOXIDE, BUTANOL SOLVATE
No full textThe crystal structure of a heterochiral peptide, viz. Boc-D-Val-Ala-Leu-Ala-OMe, with a D-residue in the beginning of the sequence has been determined (a = 9.464(5), b = 35.615(5), c = 9.703(2) Angstrom, space group P2(1)2(1)2, Z = 4, R = 0.09). The peptide is in the extended beta-conformation and the packing is stabilised by four N-H...O hydrogen bonds in an antiparallel beta-sheet arrangement. The solvent molecule is disordered and does not have any specific interactions with the peptide. (C) Munksgaard 1995
Immunohistochemical localization and expression of fibromodulin in adult rat periodontium and inflamed human gingiva
No full textCopyright © 2004 Blackwell Munksgaard The definitive version is available at www.blackwell-synergy.comObjectiveThe aim of this study was to determine the distribution and expression of fibromodulin in adult rat periodontal tissues and inflamed human gingiva.Materials and methodsThe distribution of fibromodulin in rat molar periodontium and human gingival tissue was studied by immunohistochemistry. The expression of fibromodulin mRNA from human gingival fibroblasts, periodontal ligament fibroblasts and osteoblasts was studied by reverse transcription-polymerase chain reaction (RT-PCR). For comparative purposes, the distribution and mRNA expression of collagen types I and III, as well as the two small leucine-rich proteoglycans decorin and biglycan were also studied.ResultsIn the adult rat periodontium, fibromodulin was distributed in the suprabasal gingival epithelium, gingival and periodontal fibroblasts as well as their surrounding extracellular matrices. Strong expression was noted in the palatal gingival tissues and the interfaces of the periodontal ligament with alveolar bone and cementum. In human gingival tissues, staining of fibromodulin was detected in the connective tissue of inflamed gingiva associated with both gingivitis and periodontitis; whereas, weak staining for this molecule was noted in healthy gingival tissues. The expression of mRNA for fibromodulin was strongest in the cultured osteoblasts. Periodontal ligament fibroblasts showed only a weak level of expression for fibromodulin mRNA.ConclusionsFibromodulin is differentially expressed throughout the periodontium being primarily associated with collagen type I in non-mineralized sites. In addition fibromodulin showed an upregulation in inflamed gingival tissue.H Qian, Y Xiao, PM Bartol
Crystal structures of heterochiral peptides .2. tert-Boc-valyl-D-alanyl-leucyl-alanyl methoxide
No full textCrystal structure of a heterochiral peptide, viz. Bac-Val(1)-D-Ala(2)-Leu(3)-Ala(4)-OMe with a D chiral residue in the second position of a sequence, has been determined [a = 40.44(1), b = 4.887(5), c = 15.381(5) Angstrom, beta = 109.6(1)degrees, space group C2, Z = 4, R = 0.11]. The peptide is in a parallel beta-sheet structure terminated by a distinct local bend. The structure is stabilised by N-H ... O as well as C-alpha-N ... O hydrogen bonds,The contiguous C-alpha-H ... O hydrogen bond observed in this structure is an unique observation. (C) Munksgaard 1997
Solution conformation of a peptide corresponding to residues 151-172 of HIV-1 integrase using NMR and CD spectroscopy
No full text[[abstract]]The solution structure of a synthetic peptide corresponding to residues 151-172 of HIV-1 integrase has been determined by NMR and CD spectroscopy. Residues 151-172 of HIV-1 integrase were predicted to be an alpha-helix and to be responsible for the oligomerization of HIV-1 integrase. Two-dimensional 1H NMR and CD studies indicate that this synthetic peptide adopts an amphipathic alpha-helical conformation in TFE-containing solution. However, concentration-dependent CD studies reveal that this peptide motif does not form dimers or oligomers in solution as predicted. These results are in agreement with the crystal structure of the catalytic domain of HIV-1 integrase reported recently.[[fileno]]2050134010078[[department]]生科
Structural versatility of peptides from C-alpha,C-alpha-disubstituted glycines: Crystal-state conformational analysis of peptides from C-alpha-methylhomophenylalanine, (alpha Me)Hph
No full textThe molecular and crystal structures of the C-alpha-tetrasubstituted, delta-branched alpha-amino acid C-alpha-methylhomophenylalanine, H-D-(alpha Me)Hph-OH, and three peptides (to the pentamer level), including the homotripeptide, have been determined by X-ray diffraction. The peptides are Z-L-(alpha Me)Hph-(L-Ala)(2)-OMe, pBrBz-[D-(alpha Me)Hph](3)-OtBu and Ac-(Aib)(2)-L-(alpha Me)Hph-(Aib)(2)-OtBu. All the (alpha Me)Hph residues prefer phi,psi torsion angles in the helical region of the conformational map. The two terminally blocked tripeptides adopt a beta-bend conformation stabilized by a 1<--4 C=O ... H-N intramolecular H-bond. The terminally blocked pentapeptide is folded in a regular 3(10)-helix. In general, the relationship between (alpha Me)Hph alpha-carbon chirality and helix handedness is the same as that exhibited by protein amino acids. A comparison is also made with the conclusions extracted from published work on peptides from other types of C-alpha-alkylated aromatic alpha-amino acids. (C) Munksgaard 1996
Bis[N-(2,6-Dimethylphenyl)Amino-Glyoximato-N,N']Nickel(II)
No full textThe title compound consists of discrete centrosymmetric [Ni(C10H12N3O2)(2)] molecules. The coordination around the Ni atom is square planar, involving four oxime N atoms of two chelating C2H2N2O2 groups. The oxime O atoms are linked by an intramolecular hydrogen bond [O ... O 2.546 (2) Angstrom] The Ni-N distances are 1.891 (2) and 1.846 (2) Angstrom, and the N-Ni-N angle within the NiC2N2 chelate ring is 82.75 (8)degrees. In the central portion of the molecule, the C=N distances are equal [1.297(3) and 1.298(3) Angstrom], while the two N-O distances are different [1.303 (3) and 1.386 (3) Angstrom].WoSScopu
Morphological and molecular analysis of idiopathic gingival fibromatosis : a case report
No full textAIM: We analyse a case of idiopathic gingival overgrowth using morphological and molecular methods. As this overgrowth involves collagen accumulation in the gingival connective tissue, we measured the collagen turnover to clarify the pathogenic mechanisms potentially involved. MATERIALS AND METHODS: The patient was a 29-year-old Italian woman with enlargement of the gingivae throughout the entire mandible and maxilla. Morphological analyses were carried out on haematoxylin-eosin and Sirius red-stained paraffin-embedded gingival sections. mRNA levels of collagen type I and III, matrix metalloproteinase (MMP)-1, transforming growth factor-beta1 and lysyl hydroxylase (LH)2b were determined by RT-PCR on cultured gingival fibroblasts and compared with healthy control fibroblasts. Interstitial collagen and MMP-1 content in the supernatants were assessed, respectively, by dot blot and SDS zymography. RESULTS AND CONCLUSIONS: In Sirius red-stained sections of the patient's overgrown gingivae, interstitial collagen content was 29% higher than controls. Her gingival fibroblasts had higher collagen type I, MMP-1 and LH2b gene expression and unmodified interstitial collagen, type I protein levels in the supernatants. These findings would seem to suggest that in this case collagen accumulation in the gingival connective tissue was not associated with increased synthesis and decreased degradatio
N,N,N ',N '-tetramethylethylenediammonium dichloride
No full textkabak, mehmet/0000-0001-6097-9394The structure of the title compound, C6H18N22+. 2Cl(-), has been determined and has a centre of symmetry, The molecule has strong intermolecular hydrogen bonding between each Cl- and an N-H bond [Cl ... N = 3.012 (3) Angstrom]
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