177,330 research outputs found
Crystal structures of bovine odorant-binding protein in complex with odorant molecules
No full textThe structure of bovine odorant-binding protein (bOBP) revealed a striking feature of a dimer formed by domain swapping [Tegoni, M., Ramoni, R., Bignetti, E., Spinelli, S. & Cambillau, C. (1996) Nat. Struct. Biol.3, 863-867; Bianchet, M.A., Bains, G., Pelosi, P., Pevsner, J., Snyder, S.H., Monaco, H.L. & Amzel, L.M. (1996) Nat. Struct. Biol.3, 934-939] and the presence of a naturally occuring ligand [Ramoni, R., Vincent, F., Grolli, S., Conti, V., Malosse, C., Boyer, F.D., Nagnan-Le Meillour, P., Spinelli, S., Cambillau, C. & Tegoni, M. (2001) J. Biol. Chem.276, 7150-7155]. These features led us to investigate the binding of odorant molecules with bOBP in solution and in the crystal. The behavior of odorant molecules in bOBP resembles that observed with porcine OBP (pOBP), although the latter is monomeric and devoid of ligand when purified. The odorant molecules presented K(d) values with bOBP in the micromolar range. Most of the X-ray structures revealed that odorant molecules interact with a common set of residues forming the cavity wall and do not exhibit specific interactions. Depending on the ligand and on the monomer (A or B), a single residue--Phe89--presents alternate conformations and might control cross-talking between the subunits. Crystal data on both pOBP and bOBP, in contrast with binding and spectroscopic studies on rat OBP in solution, reveal an absence of significant conformational changes involving protein loops or backbone. Thus, the role of OBP in signal triggering remains unresolved
3D scaffolds prepared from platelet rich plasma versus conventional plastic surface for culturing adipose-derived canine mesenchymal stem cells and stromal vascular fraction cells
No full text3D scaffolds prepared from Platelet Rich Plasma versus conventional plastic surface for culturing adipose-derived canine Mesenchymal Stromal Cells and Stromal Vascular Fraction cells.
Suelzu C., Conti V., Basini G., Ramoni R. and Grolli S.
Dipartimento di Scienze Mediche Veterinarie, Università di Parma
OBJECTIVE: Mesenchymal Stem Cells (MSCs) are considered a valuable tool for regenerative medicine applications. Stromal vascular fraction (SVF), a heterogeneous population of cells derived from adipose tissue, represents a valid source of MSCs. We evaluated the ability of canine MSCs and adipose-derived SVF cells to be amplified in vitro by exploiting, in addition to the canonical plastic adhesion, a three-dimensional matrix obtained by gelling Platelet Rich Plasma (PRP) or Platelet Poor Plasma (PPP). The aim was to evaluate the possibility of obtaining autologous preparations capable of supporting MSCs and SVF cells growth for the "point of care" application in the veterinary clinic.
MATERIALS AND METHODS: 1. MSCs growth on plastic surface vs 3D fibrin matrix. Total cell number, cell doubling time and cell doubling number of MSCs grown on plastic surface were compared to MSCs cells grown inside a 3D-fibrin matrix prepared by mixing PPP or PPP (50%v/v), DMEM, thrombin (10% v/v) and calcium gluconate (100mg/ml, 10%v/v). 2. SVF growth on plastic surface vs 3D fibrin matrix. SVF cells prepared by collagenase type-I digestion were cultured either on conventional culture dishes or within a 3D fibrin matrix. Total cell number, cell doubling time and cell doubling number were determined for both culture conditions until P3. 3.Phenotypic characterization by RT-PCR of MSCs and SVF cells. Gene expression was compared between MSCs and SVF grown in different culture conditions, i.e. plastic surface versus 3D fibrin matrix. A set of typical MSCs markers and gene involved in their biological properties were evaluated.
RESULTS: Canine MSCs grow within 3D fibrin-based matrices, demonstrating a shorter doubling time and a higher duplication rate when compared to cells grown on the plastic surface: the number of cells obtained is about seven-fold higher in the 3D environment after 144 hours of culture (p<0.01). Moreover, the cells included herein can be frozen and sub-cultured. In our experimental setup, the use of PRP instead of PPP in the preparation of the matrix does not modify cell replication rate. RT-PCR characterisation of cells cultured within the 3D matrix confirms the expression framework of MSCs markers. Furthermore, 3D environment improves SVF cells replication rate, producing at the first culture passage, a mean 1.5-fold increase in cell number.
CONCLUSION: 3D matrices prepared with autologous PRP or PPP are suitable for canine MSCs and SVF cells cultures. Cells grow faster than in standard 2D culture on the plastic surface, while they maintain their panel of gene expression. Furthermore, they can be sub-cultured and frozen for future applications. These results could contribute to set-up more effective MSCs-based therapies, with advantages regarding time shortening for the production of adequate amounts of cells to be applied in the clinical practice
Amicrobial pustulosis of the folds : report of 6 cases and a literature review
No full textAmicrobial pustulosis of the folds (APF) is a rare entity characterized by relapsing pustular lesions involving mainly the cutaneous folds. The disease typically occurs in the context of an autoimmune disorder and is classified within the spectrum of neutrophilic dermatoses. OBJECTIVE: We studied 6 young females having APF associated with various autoimmune diseases or with the presence of serum autoantibodies and reviewed the literature, in order to give a clinical overview on this syndrome. METHODS: Various routine and immunological laboratory tests, histopathological examination as well as direct and indirect immunofluorescence examinations were performed. In vitro neutrophil function was evaluated in 5 cases. We report our findings and compare our cases with those published in the literature. RESULTS: Clinically, at least one major fold and at least one minor fold as well as the anogenital area were always involved. We documented an impaired neutrophil chemotaxis in 2 subjects, neutrophil dysfunction, thus failing to be a verifying criterion. CONCLUSION: APF is a neutrophilic dermatosis affecting young females, which usually shows a benign clinical behavior. Although systemic corticosteroids are the most widely used therapeutic agents, we suggest that the combination of cimetidine and ascorbic acid represents a safe alternative, which may induce long-lasting clinical remissio
Congenital heart block not associated with anti-Ro/La antibodies: comparison with anti-Ro/La-positive cases.
No full textJ Rheumatol. 2009 Aug;36(8):1744-8. Epub 2009 Jun 30.
Congenital heart block not associated with anti-Ro/La antibodies: comparison with anti-Ro/La-positive cases.
Brucato A, Grava C, Bortolati M, Ikeda K, Milanesi O, Cimaz R, Ramoni V, Vignati G, Martinelli S, Sadou Y, Borghi A, Tincani A, Chan EK, Ruffatti A.
Source
Medicina Interna, Ospedali Riuniti, Bergamo, Italy. [email protected]
Abstract
OBJECTIVE:
To study anti-Ro/La-negative congenital heart block (CHB).
METHODS:
Forty-five fetuses with CHB were evaluated by analysis of anti-Ro/La antibodies using sensitive laboratory methods.
RESULTS:
There were 9 cases of anti-Ro/La-negative CHB; 3 died (33.3%). Only 3 (33.3%) were complete in utero and 5 (55.5%) were unstable. No specific etiology was diagnosed. Six infants (66.6%) were given pacemakers. There were 36 cases of anti-Ro/La-positive CHB. All except 2 infants (94.4%) had complete atrioventricular block in utero. Ten died (27.8%), one (2.7%) developed severe dilated cardiomyopathy, and 26 (72.2%) were given pacemakers.
CONCLUSION:
Nine of the 45 consecutive CHB cases (20%) were anti-Ro/La-negative with no known cause. They were less stable and complete than the anti-Ro/La positive cases.
PMID:
19567621
[PubMed - indexed for MEDLINE]
PMCID: PMC279858
Pregnancy outcomes in patients with autoimmune diseases and anti-Ro/SSA antibodies
No full textAnti-Ro/SSA antibodies are associated with neonatal lupus (congenital heart block (CHB), neonatal transient skin rash, hematological and hepatic abnormalities), but do not negatively affects other gestational outcomes, and the general outcome of these pregnancies is now good, when followed by experienced multidisciplinary teams. The prevalence of CHB, defined as an atrioventricular block diagnosed in utero, at birth, or within the neonatal period (0-27 days after birth), in the offspring of an anti-Ro/SSA-positive women is 1-2%, of neonatal lupus rash around 10-20%, while laboratory abnormalities in asymptomatic babies can be detected in up to 27% of cases. The risk of recurrence of CHB is ten times higher. Most of the mothers are asymptomatic at delivery and are identified only by the birth of an affected child. Half of these asymptomatic women develop symptoms of a rheumatic disease, most commonly arthralgias and xerophtalmia, but few develop lupus nephritis. A standard therapy for CHB is still matter of investigation, although fluorinated corticosteroids have been reported to be effective for associated cardiomyopathy. Serial echocardiograms and obstetric sonograms, performed at least every 1-2 weeks starting from the 16th week of gestational age, are recommended in anti-Ro/SSA-positive pregnant women to detect early fetal abnormalities that might be a target of preventive therapy
Appropriate Similarity Measures for Author Cocitation Analysis
No full textWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Influence of heat-treated Cu-Be electrode on machining accuracy in ECMM with Monel 400 alloy
No full textMonel 400 is a nickel-copper alloy utilized in marine and oil refining industries owing to its high corrosion resistance and fire withstanding property. The machining of such higher strength material with complex shapes is possible with electrochemical micromachining (ECMM) process, since it can machine with less wear, better precision, micro-level hole profiles, no heat-affected zone and no thermal stresses. The present study was performed with machining of Monel 400 alloy in ECMM process with copper-beryllium wire electrode under various heat treatments, such as annealing, quenching and normalizing. The lower overcut can be obtained using quenched tool electrode when compared to the other treated tools and untreated tool electrode owing to its fine grain structure which restricts the flow of electrons to side of the tool. The conicity with normalized tool electrode is lower, since it exhibits high electrical conductivity by decreasing the distraction of electrons. Circularity with quenched tool electrode is lower due to its fine grain structure and higher electrical conductivity, since its localization effect increases causing uniform stray current
Influence of additive manufactured stainless steel tool electrode on machinability of beta titanium alloy
No full textAdditive manufacturing technology provides a gateway to completely new horizons for producing a wide range of components, such as manufacturing, medicine, aerospace, automotive, and space explorations, especially in non-conventional manufacturing processes. The present study analyzes the influence of the additive manufactured tool in electrochemical micromachining (ECMM) on machining beta titanium alloy. The influence of different machining parameters, such as applied voltage, electrolytic concentration, and duty ratio on material removal rate (MRR), overcut, and circularity was also analyzed. It was inferred that the additive manufactured tool can produce better circularity and overcut than a bare tool due to its higher corrosion resistance and localization effect. The additive manufactured tool can remove more material owing to its strong atomic bond of metals and higher electrical conductivity
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