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Reversible Brain Edema Associated with Flow Diverter Stent Procedures: A Retrospective Single- Center Study to Evaluate Frequency, Clinical Evolution, and Possible Mechanism. World Neurosurg 2018; 122:e569-e576. [PMID: 30394357 DOI: 10.1016/j.wneu.2018.10.103] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2018] [Revised: 10/14/2018] [Accepted: 10/16/2018] [Indexed: 10/28/2022]
Abstract
BACKGROUND Hemorrhage and ischemia after flow diverter stent (FDS) procedures for intracranial aneurysms are the most common complications and have been extensively described. Temporary brain edema (TBE) is an unknown complication that could be associated with particular FDS procedures. OBJECTIVE To estimate the frequency, clinical presentation, imaging findings, and possible mechanisms associating TBE with FDS. METHODS Unruptured aneurysms treated with FDS implantation performed in our service from June 2015 to March 2018 were reviewed. Medical antecedents, endovascular procedure, clinical assessments before and after treatment, aneurysm characteristics, and image records were collected. Artery diameters of patients in whom TEB developed were also calculated to investigate any correlation between TBE and anatomic descriptors. RESULTS A total of 179 FDS procedures in 176 patients were reviewed. Six patients (3.4%) presented with symptomatic TBE, and all TBE patients had undergone FDS implantation from the middle cerebral artery (MCA) to the internal carotid artery (ICA). A Pearson product-moment correlation coefficient (PPCC) found smaller MCA diameters and MCA/ICA ratios in these 6 patients (respectively PPCC = -0.619, P < 0.04; PPCC = -0.647, P < 0.03). Hemorrhagic and ischemic complications were less frequent than TBE (2.3% and 1.1% vs. 3.4%). CONCLUSIONS TBE was more frequent than ischemic or hemorrhagic complications after FDS in this study. TBE seemed to be associated with a particular FDS positioning in small arteries, inducing flow changes and disruption of the blood-brain barrier.
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Abstract WP90: The Role of Haemodynamics in a Bifurcation Vessel Narrowing or Occlusion After Aneurysm Treatment with Flow Diverter Stents. Stroke 2017. [DOI: 10.1161/str.48.suppl_1.wp90] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background and Purpose:
Treatment of intracranial aneurysms at bifurcations with flow-diverter stents (FDS) can lead to occlusion/narrowing of the distal vessels. This study investigated the role played by haemodynamics within different bifurcation types treated with FDS.
Materials and Methods:
Radiological images, demographic and outcome data were acquired for 25 bifurcating aneurysm treated with FDS. Statistical analysis was used to correlate the event of occlusion/narrowing with anatomical data. Computational Fluid Dynamics (CFD) study was performed on idealized and patient-specific anatomies to identify possible cause-effect mechanisms mediated by haemodynamics.
Results:
Statistical analysis identified marked correlation between asymmetric bifurcation and occlusion/narrowing (diameters ratio=DR=1 symmetric, <1 asymmetric). CFD predictions in both idealized and patient-specific anatomies showed that wall shear stress (WSS) in the jailed vessel is mostly affected when FDS are deployed in non-symmetric bifurcations (DR<0.65), and least affected when deployed in symmetric anatomies (DR = 1.00).
Conclusion:
Analysis of the anatomical data showed statistically significant correlations between occlusion/narrowing and bifurcation asymmetry characterized by DR<0.7. Similarly, CFD results showed that FDS have the highest impact on haemodynamics when deployed in bifurcations with higher degrees of anatomical asymmetry (DR<0.65) with strong changes induced on the WSS fields. This suggests a higher risk associated to FDS-treatment of asymmetric bifurcation together with a possible FDS-induced pathway leading to occlusion/narrowing of arteries and mediated by haemodynamics and endothelial response.
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Endothelial repair in stented arteries is accelerated by inhibition of Rho-associated protein kinase. Cardiovasc Res 2016; 112:689-701. [PMID: 27671802 PMCID: PMC5157135 DOI: 10.1093/cvr/cvw210] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/31/2016] [Revised: 09/09/2016] [Accepted: 09/17/2016] [Indexed: 12/14/2022] Open
Abstract
Aims Stent deployment causes endothelial cells (EC) denudation, which promotes in-stent restenosis and thrombosis. Thus endothelial regrowth in stented arteries is an important therapeutic goal. Stent struts modify local hemodynamics, however the effects of flow perturbation on EC injury and repair are incompletely understood. By studying the effects of stent struts on flow and EC migration, we identified an intervention that promotes endothelial repair in stented arteries. Methods and Results In vitro and in vivo models were developed to monitor endothelialization under flow and the influence of stent struts. A 2D parallel-plate flow chamber with 100 μm ridges arranged perpendicular to the flow was used. Live cell imaging coupled to computational fluid dynamic simulations revealed that EC migrate in the direction of flow upstream from the ridges but subsequently accumulate downstream from ridges at sites of bidirectional flow. The mechanism of EC trapping by bidirectional flow involved reduced migratory polarity associated with altered actin dynamics. Inhibition of Rho-associated protein kinase (ROCK) enhanced endothelialization of ridged surfaces by promoting migratory polarity under bidirectional flow (P < 0.01). To more closely mimic the in vivo situation, we cultured EC on the inner surface of polydimethylsiloxane tubing containing Coroflex Blue stents (65 μm struts) and monitored migration. ROCK inhibition significantly enhanced EC accumulation downstream from struts under flow (P < 0.05). We investigated the effects of ROCK inhibition on re-endothelialization in vivo using a porcine model of EC denudation and stent placement. En face staining and confocal microscopy revealed that inhibition of ROCK using fasudil (30 mg/day via osmotic minipump) significantly increased re-endothelialization of stented carotid arteries (P < 0.05). Conclusions Stent struts delay endothelial repair by generating localized bidirectional flow which traps migrating EC. ROCK inhibitors accelerate endothelial repair of stented arteries by enhancing EC polarity and migration through regions of bidirectional flow.
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292Endothelial cell forward migration in a disturbed wall shear stress environment is promoted by ROCK inhibition. Cardiovasc Res 2014. [DOI: 10.1093/cvr/cvu087.6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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219 Rock Inhibits Endothelial Migration in Disturbed flow Condition: A Potential Therapeutic Target in PCI. BRITISH HEART JOURNAL 2014. [DOI: 10.1136/heartjnl-2014-306118.219] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Abstract 521: Endothelial Cell Forward Migration in a Disturbed Wall Shear Stress Environment is Promoted by Rho-Kinase Inhibition. Arterioscler Thromb Vasc Biol 2014. [DOI: 10.1161/atvb.34.suppl_1.521] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Stent deployment to treat coronary artery disease causes damage and loss of endothelial cells (EC). Repair of injured arteries by EC migration is co-ordinated by Rho family GTPases. It is also regulated by wall shear stress (WSS), a mechanical force exerted by flowing blood on the vessel wall, via mechanisms that are poorly understood. It was hypothesised that stent struts may impede repair of injured endothelium by inducing localised disturbances in WSS.
To simulate a stented artery in vitro, chamber slides were fabricated with ridges (100 μm high) positioned perpendicularly to the flow direction. Confluent EC monolayers seeded on one side of either ridged or non-ridged (control) chambers were exposed to flowing culture medium (Ibidi® system). Flow patterns were determined by computational fluid dynamic (CFD) modelling and particle velocimetry. Live cell imaging and analysis using ImageJ® software enabled quantification of EC migration velocity and directional persistence (DP).
EC on the non-ridged chamber slide were exposed to a uniform WSS of 13 dyn/cm2 and migrated relatively uniformly in parallel with the flow direction (average velocity 1.13 μm/min; DP 0.59). By contrast, CFD and particle velocimetry revealed spatial WSS differences over the ridged chamber, with significant spikes above physiological levels (>70 dyn/cm2) at the corners of the ridges and distinctive flow recirculation zone immediately downstream from ridges (-4 dyn/cm2). While EC were able to migrate over the ridges, cells that reached the recirculation zone displayed non-uniform directionality (DP 0.25) and reduced velocity (0.78 μm/min). Inhibition of the RhoA signalling pathway with ROCK inhibitors promoted EC forward migration within the recirculation zone by elevating DP (0.41) and velocity (1.16 μm/min).
It was concluded that disturbed WSS downstream from stent strut-like ridges prevented the forward migration of EC. Inhibition of the RhoA/ROCK signaling pathway promoted EC migration and re-population of these sites. Our data suggest that treatment using a ROCK inhibitor may promote re-endothelialisation of stented arteries.
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Transient upregulation of GRP and its receptor critically regulate colon cancer cell motility during remodeling. Am J Physiol Gastrointest Liver Physiol 2005; 288:G1274-82. [PMID: 15890713 DOI: 10.1152/ajpgi.00108.2004] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Gastrin-releasing peptide (GRP) is typically viewed as a growth factor in cancer. However, we have suggested that in colon cancer, GRP acts primarily as a morphogen when it and its receptor (GRP-R) are aberrantly upregulated. As such, GRP/GRP-R act(s) primarily to modulate processes contributing to the assumption or maintenance of tumor differentiation. One of the most important such processes is the ability of tumor cells to achieve directed motility in the context of tissue remodeling. Yet the cellular conditions affecting GRP/GRP-R expression, and the biochemical pathways involved in mediating its morphogenic properties, remain to be established. To study this, we evaluated the human colon cancer cell lines Caco-2 and HT-29 cells. We found that confluent cells do not express GRP/GRP-R. In contrast, disaggreation and plating at subconfluent densities results in rapid GRP/GRP-R upregulation followed by their progressive decrease as confluence is achieved. GRP/GRP-R coexpression correlated with that of focal adhesion kinase (FAK) phosphorylation of Tyr(397), Tyr(407), Tyr(861), and Tyr(925) but not Tyr(576) or Tyr(577). To more specifically evaluate the kinetics of GRP/GRP-R upregulation, we wounded confluent cell monolayers. At t = 0 h GRP/GRP-R were not expressed, yet cells immediately began migrating into the gap created by the wound. GRP/GRP-R were first detected at approximately 2 h, and maximal levels were observed at approximately 6 h postwounding. The GRP-specific antagonist [d-Phe(6)]-labeled bombesin methyl ester had no effect on cell motility before GRP-R expression. In contrast, this agent increasingly attenuated cell motility with increasing GRP-R expression such that from t = 6 h onward no further cell migration into the gap was observed. Overall, these findings indicate the existence of GRP-independent and -dependent phases of tumor cell remodeling with the latter mediating colon cancer cell motility during remodeling via FAK.
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Abstract
The Sertoli cell ectoplasmic specialization (ES) is a specialized domain of the calcium-dependent Sertoli cell-spermatid junctional complex. Not only is it associated with the mechanical adhesion of the cells, but it also plays a role in the morphogenesis and differentiation of the developing germ cells. Abnormal or absent Sertoli ESs have been associated with step-8 spermatid sloughing and subsequent oligospermia. With a micropipette pressure transducing system (MPTS) to measure the force needed to detach germ cells from Sertoli cells, this study examined, for the first time, the strength of the junction between Sertoli cells and spermatids and between Sertoli cells and spermatocytes. The mean force needed to detach spermatocytes from Sertoli cells was 5.25 x 10(-7) pN, prestep-8 spermatids from Sertoli cells was 4.73 x 10(-7) pN, step-8 spermatids from Sertoli cells was 8.82 x 10(-7) pN, and spermatids plus EDTA was 2.16 x 10(-7) pN. These data confirm the hypothesis that step-8 spermatids are more firmly attached to Sertoli cells than are spermatocytes and pre-step-8 spermatids and that calcium chelation reduces binding strength between Sertoli cells and spermatids. The MPTS is a useful tool in studying the various molecular models of the Sertoli-germ cell junctional strength and the role of reproductive hormones and enzymes in coupling and uncoupling of germ cells from Sertoli cells.
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A novel monoclonal antibody against the extracellular domain of GPIbbeta modulates vWF mediated platelet adhesion. Thromb Haemost 2001; 86:1238-48. [PMID: 11816713] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
Abstract
GPIbbeta is disulfide-linked to GPIbalpha to form GPIb, a platelet receptor for von Willebrand factor (vWF). GPIb is in turn non covalently linked to GPIX and GPV to form the GPIb/V/IX complex. Apart from its contribution to controlling surface expression of the complex, the exact function of GPIbbeta is not well established due to a lack of suitable ligands or antibodies. The present report describes a monoclonal antibody (RAM.1) that labeled the 26 kDa GPIbbeta subunit on western blots and coprecipitated the three subunits of the GPIb/IX complex from lysates of platelets and transfected CHO and K562 cells. RAM.1 bound to GPIbbeta deleted of its intracellular domain whereas Gi27, directed against intracellular GPIbbeta, did not. Using synthetic peptides, the RAM.1 epitope was mapped to a putative cysteine loop within the COOH-terminal leucine-rich flanking region. In functional assays, RAM.1 had no effect on platelet aggregation induced by ADP, collagen or thrombin, but inhibited ristocetin induced platelet agglutination and botrocetin induced vWF binding. RAM.1 inhibited adhesion of GPIb/V/IX transfected K562 cells to a vWF matrix under flow, increased their rolling velocity and decreased the resistance of cells to detachment at high shear. This study suggests a role of GPIbbeta in modulating the adhesive properties of GPIb/V/IX and describes a useful tool to analyze the exact functions of GPIbbeta.
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Proteolysis of the exodomain of recombinant protease-activated receptors: prediction of receptor activation or inactivation by MALDI mass spectrometry. Biochemistry 2000; 39:10812-22. [PMID: 10978167 DOI: 10.1021/bi0003341] [Citation(s) in RCA: 80] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Protease-activated receptors (PARs) mediate cell activation after proteolytic cleavage of their extracellular amino terminus. Thrombin selectively cleaves PAR1, PAR3, and PAR4 to induce activation of platelets and vascular cells, while PAR2 is preferentially cleaved by trypsin. In pathological situations, other proteolytic enzymes may be generated in the circulation and could modify the responses of PARs by cleaving their extracellular domains. To assess the ability of such proteases to activate or inactivate PARs, we designed a strategy for locating cleavage sites on the exofacial NH(2)-terminal fragments of the receptors. The first extracellular segments of PAR1 (PAR1E) and PAR2 (PAR2E) expressed as recombinant proteins in Escherichia coli were incubated with a series of proteases likely to be encountered in the circulation during thrombosis or inflammation. Kinetic and dose-response studies were performed, and the cleavage products were analyzed by MALDI-TOF mass spectrometry. Thrombin cleaved PAR1E at the Arg41-Ser42 activation site at concentrations known to induce cellular activation, supporting a native conformation of the recombinant polypeptide. Plasmin, calpain and leukocyte elastase, cathepsin G, and proteinase 3 cleaved at multiple sites and would be expected to disable PAR1 by cleaving COOH-terminal to the activation site. Cleavage specificities were further confirmed using activation site defective PAR1E S42P mutant polypeptides. Surface plasmon resonance studies on immobilized PAR1E or PAR1E S42P were consistent with cleavage results obtained in solution and allowed us to determine affinities of PAR1E-thrombin binding. FACS analyses of intact platelets confirmed the cleavage of PAR1 downstream of the Arg41-Ser42 site. Mass spectrometry studies of PAR2E predicted activation of PAR2 by trypsin through cleavage at the Arg36-Ser37 site, no effect of thrombin, and inactivation of the receptor by plasmin, calpain and leukocyte elastase, cathepsin G, and proteinase 3. The inhibitory effect of elastase was confirmed on native PAR1 and PAR2 on the basis of Ca(2+) signaling studies in endothelial cells. It was concluded that none of the main proteases generated during fibrinolysis or inflammation appears to be able to signal through PAR1 or PAR2. This strategy provides results which can be extended to the native receptor to predict its activation or inactivation, and it could likewise be used to study other PARs or protease-dependent processes.
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MESH Headings
- Amino Acid Sequence
- Blood Platelets/metabolism
- Calcium Signaling
- Cell Line
- Chromatography, High Pressure Liquid
- Chromatography, Liquid
- Endopeptidases/metabolism
- Escherichia coli/genetics
- Flow Cytometry
- Humans
- Hydrolysis
- Mass Spectrometry
- Molecular Sequence Data
- Pancreatic Elastase/physiology
- Peptide Fragments/biosynthesis
- Peptide Fragments/chemistry
- Peptide Fragments/genetics
- Peptide Fragments/metabolism
- Protein Structure, Tertiary/genetics
- Receptor, PAR-1
- Receptor, PAR-2
- Receptors, Thrombin/antagonists & inhibitors
- Receptors, Thrombin/chemistry
- Receptors, Thrombin/genetics
- Receptors, Thrombin/metabolism
- Recombinant Proteins/antagonists & inhibitors
- Recombinant Proteins/biosynthesis
- Recombinant Proteins/chemistry
- Recombinant Proteins/metabolism
- Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
- Surface Plasmon Resonance
- Thrombin/agonists
- Thrombin/metabolism
- Trypsin/metabolism
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Modulation by heparin of the interaction of the A1 domain of Von Willebrand factor with glycoprotein Ib. Blood 1999; 94:4186-94. [PMID: 10590063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/14/2023] Open
Abstract
The conformation of the A1 domain of von Willebrand factor (vWF) is a critical determinant of its interaction with the glycoprotein (GP) Ib/V/IX complex. To better define the regulatory mechanisms of vWF A1 domain binding to the GPIb/V/IX complex, we studied vWF-dependent aggregation properties of a cell line overexpressing the GPIbalpha, GPIbbeta, and GPIX subunits (CHO-GPIbalphabeta/IX cells). We found that CHO-GPIbalphabeta/IX cell aggregation required the presence of both soluble vWF and ristocetin. Ristocetin-induced CHO-GPIbalphabeta/IX cell aggregation was completely inhibited by the recombinant VCL fragment of vWF that contains the A1 domain. Surprisingly, the substitution of heparin for ristocetin resulted in the formation of CHO-GPIbalphabeta/IX cell aggregates. Using monoclonal antibodies blocking vWF interaction with GPIb/V/IX or mocarhagin, a venom metalloproteinase that removes the amino-terminal fragment of GPIbalpha extending from aa 1 to 282, we demonstrated that both ristocetin- and heparin-induced aggregations involved an interaction between the A1 domain of vWF and the GPIbalpha subunit of the GPIb/V/IX complex. The involvement of heparin in cell aggregation was also demonstrated after treatment of heparin with heparinase that abolished CHO-GPIbalphabeta/IX cell aggregation. These results indicated that heparin was able to induce vWF-dependent CHO-GPIbalphabeta/IX cell aggregation. In conclusion, we demonstrated that heparin is capable of positively modulating the vWF interaction with the GPIb/V/IX complex.
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Ser752 mutation to Pro or Ala in the beta3 integrin subunit differentially affects the kinetics of cell spreading to von Willebrand factor and fibrinogen. CELL ADHESION AND COMMUNICATION 1998; 6:335-48. [PMID: 9865467 DOI: 10.3109/15419069809010792] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
The beta3 cytoplasmic domain of the alpha v beta3 integrin is essential for intracellular signals required for cytoskeletal rearrangements. Expression of beta3Ser752Pro mutation in heterologous cells profoundly affects cell spreading and beta3 localization into focal contacts. However, the beta3Ser752Ala substitution mostly restores normal integrin functions, suggesting that the presence of Pro is responsible for the receptor's loss of function. To further assess the role of the Ser752 of the beta3 cytoplasmic domain in the cytoskeletal organization of adherent cells, we developed a computer-assisted method of image analysis allowing the automatic classification of spread cells according to the quantitative analysis of their cell morphology. We compared adhesion and spreading to von Willebrand factor (vWF) or fibrinogen (Fg) of cells expressing beta3 wild type, beta3Ser752Pro or beta3Ser752Ala mutated integrin subunit as a chimeric alpha v beta3 receptor. The beta3Ser752Ala substitution did not impair the general ability of cells to spread, but resulted in a delayed and reduced spreading on both vWF and Fg. Moreover, the beta3Ser752Ala mutation produced modifications of the morphology of spread cells, suggesting a disorganization of their cytoskeleton. Attachment studies showed that the beta3Ser752Ala mutation did not modify the capacity of cells to attach to the substrate, indicating no change in the ligand binding affinity of the alpha v beta3 integrin. Furthermore, we identified a slight defect of beta3Ser752Pro cell attachment to vWF and Fg, beside their impairment of spreading. Taken together, these results suggest a role of Ser752 of the beta3 cytoplasmic domain in the optimal cytoskeletal organization of adherent cells.
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Relative importance of the glycoprotein Ib-binding domain and the RGD sequence of von Willebrand factor for its interaction with endothelial cells. Blood 1997; 90:2335-44. [PMID: 9310484] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Endothelial cell adhesion to von Willebrand Factor is mainly mediated through an interaction between the alpha vbeta3 integrin and the RGD sequence of von Willebrand factor (vWF). To define the potential involvement of glycoprotein Ib alpha (GPIb alpha) as an endothelial vWF receptor, we compared cell adhesion to three recombinant vWF, the wild-type (WT-rvWF) and two mutants, RGGS-rvWF (D1746G), defective for binding to platelet alphaIIb beta3, and deltaA1-rvWF with a deletion between amino-acids 478 and 716, which does not bind to platelet GPIb alpha. Adhesion of human umbilical vein endothelial cells to purified vWF recombinants was measured by automatized cell counting using an image analyzer. Whereas cell adhesion to delta A1-rvWF was unchanged compared with WT-rvWF, reaching a plateau of 40% total cells at a concentration of 2.5 microg/mL rvWF, adhesion to RGGS-rvWF was only 10% of total cells. Cell stimulation by tumor necrosis factor-alpha (TNF alpha), reported to upregulate the expression of the putative endothelial GPIb alpha, did not modify adhesion to these rvWF. Monoclonal antibodies to vWF or GPIb alpha, blocking vWF interaction with platelet GPIb alpha, were unable to inhibit endothelial cell adhesion to rvWF. In contrast, antibody 9 to vWF, blocking the alpha vbeta3-dependent endothelial cell adhesion to plasma vWF, inhibited adhesion to WT-rvWF as efficiently as to deltaA1-rvWF (50% inhibition at a concentration of 11 and 15 microg/mL, respectively). In agreement with the fact that endothelial cell adhesion to vWF appeared independent of the GPIb alpha-binding domain, we were unable to detect endothelial surface expression of GPIb alpha by flow cytometry or in cell lysates by immunoprecipitation followed by immunoblotting. Moreover, expression of GPIb alpha mRNA was undetectable in endothelial cells, even after stimulation by TNF alpha. These studies indicate that GPIb alpha is not expressed in human cultured endothelial cells and is not involved in adhesion to vWF-containing surfaces. Thus, in static conditions, cultured endothelial cells adhere to vWF through an alpha vbeta3-dependent, GPIb alpha-independent mechanism.
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[The pediatric nurses]. SOINS; LA REVUE DE REFERENCE INFIRMIERE 1994:33-5. [PMID: 8009309] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
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Spinal catheter does not reduce post-dural puncture headache after caesarean section. Can J Anaesth 1992; 39:633-4. [PMID: 1643691 DOI: 10.1007/bf03008332] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
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[And if we speak about men?]. SANTE MENTALE AU QUEBEC 1990; 15:134-44. [PMID: 2096966] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
This article raises questions about some of the perverse effects of the reasoning behind correlations between sex and health in our socio-cultural context. Such a reasoning strongly denounces the psychosocial problems of women, but tends to forget the vulnerability of men which is nonetheless clearly evident in official statistics on suicide, dependence on alcohol and other drugs, violence and itinerancy.
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[The Santé-Québec survey and mental health of Québecers : conceptual framework and methodology.]. SANTE MENTALE AU QUEBEC 1989; 14:132-43. [PMID: 17093610] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
The Santé Québec study is the most important inquiry into health yet undertaken in Quebec on life habits and the physical and psychological state of health of almost 20,000 persons aged 15 years and over living in private homes. The mental-health section of the study is situated within the tradition of socio-epidemiological inquiries. The article describes the reasoning behind the choice of mental-health indicators (psychological well-being, psychological distress, suicide thoughts and attempts, several severe psychological problems) and the measuring instruments. The study's usefulness and limits are discussed.
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Abstract
Acute illness in early childhood generates chronic anxiety in parents, which may manifest itself in part by inappropriate use of health care. To minimize this and the development of other psychosocial sequelae associated with neonatal illness, a family support system (FSS) was developed and implemented in a neonatal intensive care unit. The effectiveness of the FSS was assessed by the evaluation of emergency room and inpatient hospital service utilization in 80 patients born before, and 90 patients born after the institution of the program. At the outset, the groups had similar medical and social characteristics. There was no difference between the two groups in the utilization of emergency services in the first year after discharge. However, during the second year the control group used the emergency room twice as often as the study group did (P less than 0.025). During the first 2 years, half of the control group was readmitted, compared with less than a third of the study group (P less than 0.005). Overall, after discharge from the neonatal intensive care unit the control group spent an average of 9 days per patient in hospital, compared with a mean of 3 days per patient in the study group (P less than 0.025). It appears, therefore, that the FSS may be an effective way to reduce some of the psychosocial sequelae of illness in newborn infants requiring intensive care.
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[Evaluation of information programs on sexual assault in six elementary schools in east Montréal.]. SANTE MENTALE AU QUEBEC 1985; 10:58-64. [PMID: 17093834] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Within the sex education program given to four hundred and sixty five (465) students approximately eleven years in age, a new information project on exhibitionism, sexual harassment, rape and incest was introduced in the eighteen (18) sixth grade classes of ten (10) elementary schools in the east end of Montréal. The evaluation of the project implementation gives us good indications of the concerted action that is necessary, the process needed to elaborate teaching material and also shows the immediate reaction of educators, parents and, of course, the students concerned. Very little resistance to this new teaching was noted within the school system. All parents had been informed of the project, no negative comments were received after-wards at schools. Incest was perceived by children as a problem "you do not speak of ' because it is susceptible to bring about worse things than the abuse itself, normaly the separation of the parents or the emprisonment of the abusive parent.
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Family support in the neonatal intensive care unit. DIMENSIONS IN HEALTH SERVICE 1979; 56:16-8. [PMID: 446939] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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22
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Upper gastrointestinal hemorrhage: aggressive management decreases mortality. Surgery 1978; 84:448-54. [PMID: 308704] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
In a retrospective study of 630 patients with upper gastrointestinal hemorrhage admitted to the Royal Victoria Hospital between 1963 and 1971, the overall mortality was 12.54%. Mortality increased in patients receiving more than 10 units of blood and in patients over 60 years of age. Mortality decreased in patients in whom the site of hemorrhage was known prior to operation. Early surgery for gastric ulcers and conservative therapy for acute gastric erosions reduced mortality. Therefore in 334 patients admitted to the Royal Victoria Hospital between 1973 and 1976 with upper gastrointestinal hemorrhage, an aggressive approach to diagnosis and management was emphasized. There was a significant decrease in patients with duodenal ulcers, acute gastric erosions, and gastric ulcers who received more than 10 units of blood. There was a significant increase in the use of endoscopy to establish the source of hemorrhage and a significant increase in the use of endoscopy to establish the source of hemorrhage and a significant decrease in the number of patients who did not have a diagnosis prior to operation. There was also a significant increase in early surgery for gastric ulcers. This regimen led to a significant decrease in mortality (6.69% vs. 12.54%). This report demonstrates that early diagnosis and management based on the lesion found reduces mortality from upper gastrointestinal hemorrhage.
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The challenge for administrators in 1980. DIMENSIONS IN HEALTH SERVICE 1976; 53:44-6. [PMID: 7489] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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L'INDEXAGE DES TUBERCULES DE POMMES DE TERRE EN VUE DE DÉCELER LA FLÉTRISSURE BACTÉRIENNE (CORYNEBACTERIUM SEPEDONICUM) (SPIECK 8 : KOTT.) SKAPTASON & BURKHOLDER. Can J Microbiol 1962. [DOI: 10.1139/m62-009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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