943 resultados para Umbilical Arteries


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HOCl-modified low-density lipoprotein (LDL) has proinflammatory effects, including induction of inflammatory cytokine production, leukocyte adhesion, and ROS generation, but the components responsible for these effects are not completely understood. HOCl and the myeloperoxidase-H2O2-halide system can modify both protein and lipid moieties of LDL and react with unsaturated phospholipids to form chlorohydrins. We investigated the proinflammatory effects of 1-stearoyl-2-oleoyl-sn-3-glycerophosphocholine (SOPC) chlorohydrin on artery segments and spleen-derived leukocytes from ApoE-/- and C57 Bl/6 mice. Treatment of ApoE-/- artery segments with SOPC chlorohydrin, but not unmodified SOPC, caused increased leukocyte-arterial adhesion in a time- and concentration-dependent manner. This could be prevented by pretreatment of the artery with P-selectin or ICAM-1-blocking antibodies, but not anti-VCAM-1 antibody, and immunohistochemistry showed that P-selectin expression was upregulated. However, chlorohydrin treatment of leukocytes did not increase expression of adhesion molecules LFA-1 or PSGL-1, but caused increased release of ROS from PMA-stimulated leukocytes by a CD36-dependent mechanism. The SOPC chlorohydrin-induced adhesion and ROS generation could be abrogated by pretreatment of the ApoE-/- mice with pravastatin or a nitrated derivative, NCX 6550. These findings suggest that phospholipid chlorohydrins formed in HOCl-treated LDL could contribute to the proinflammatory effects observed for this modified lipoprotein in vitro.

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Background: Vascular endothelial growth factor (VEGF) mediates endothelial cell mitogenesis and enhances vascular permeability. The existence of single or multiple VEGF isoforms and receptors suggests that these proteins may have overlapping but distinct functions, which may be reflected in their cell expression and distribution. Methods: The localisation of VEGFs A–C and their receptors (VEGFRs 1–3, respectively) in 30 fresh human atherosclerotic arteries, 15 normal uterine arteries, and 15 saphenous veins using immunohistochemistry and western blotting. Results: Saphenous veins showed no staining for VEGF-B or VEGFR-2. Smooth muscle cells (SMCs) showed the strongest staining for VEGF-A, VEGF-B, VEGFR-1, and VEGFR-2 in all specimens. Conversely, VEGFR-3 and VEGF-C were predominately localised to the endothelial vasa vasorum in normal arteries, whereas medial SMCs showed the strongest staining in atherosclerotic arteries. Western blotting showed variations in VEGF protein localisation, with lower amounts of VEGF-B and VEGF-C in saphenous veins, compared with arterial tissue. Amounts of VEGF-C were lower than those of VEGF-A and VEGF-B in all specimens. Conclusion: This study provides direct evidence of the presence of VEGF proteins and receptors in human physiology and pathology, with variations in both the amounts of VEGF proteins expressed and their cellular distribution in normal arteries compared with atherosclerotic arteries. The presence of VEGFs A–C and their receptors in normal arterial tissue implies that VEGF functions may extend beyond endothelial cell proliferation. Reduced VEGFR-2 staining in atherosclerotic arteries may have implications for the atherosclerosis process and the development of vascular disease and its complications.

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1 Dilatation of the cerebral vasculature is recognised to be involved in the pathophysiology of migraine. Furthermore, elevated levels of prostaglandin E2 (PGE2) occur in the blood, plasma and saliva of migraineurs during an attack, suggestive of a contributory role. In the present study, we have characterised the prostanoid receptors involved in the relaxation and contraction of human middle cerebral arteries in vitro. 2 In the presence of indomethacin (3μM) and the TP receptor antagonist GR32191 (1 μM), PGE2 was found to relax phenylephrine precontracted cerebral arterial rings in a concentration-dependent manner (mean pEC50 8.0 ± 0.1, n = 5). 3 Establishment of a rank order of potency using the EP4 > EP2 agonist 11-deoxy PGE1, and the EP2 > EP4 agonist PGE1-OH (mean pEC 50 of 7.6 ± 0.1 (n = 6) and 6.4 ± 0.1 (n = 4), respectively), suggested the presence of functional EP4 receptors. Furthermore, the selective EP2 receptor agonist butaprost at concentrations < 1 μM failed to relax the tissues. 4 Blockade of EP 4 receptors with the EP4 receptor antagonists AH23848 and EP4A caused significant rightward displacements in PGE2 concentration-response curves, exhibiting pA2 and pKB values of 5.7 ± 0.1, n = 3, and 8.4, n = 3, respectively. 5 The IP receptor agonists iloprost and cicaprost relaxed phenylephrine precontracted cerebral arterial rings (mean pEC50 values 8.3 ± 0.1 (n = 4) and 8.1 ± 0.1 (n = 9), respectively). In contrast, the DP and FP receptor agonists PGD2 and PGFα2 failed to cause appreciable relaxation or contraction at concentrations of up to 30 μM. In the absence of phenylephrine contraction and GR32191, the TP receptor agonist U46619 caused concentration-dependent contraction of cerebral artery (mean pEC50 7.4 ± 0.3, n = 3). 6 These data demonstrate the presence of prostanoid EP4 receptors mediating PGE2 vasodilatation of human middle cerebral artery. IP receptors mediating relaxation and TP receptors mediating contraction were also functionally demonstrated.

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Николай Кутев, Величка Милушева - Намираме експлицитно всичките би-омбилични фолирани полусиметрични повърхнини в четиримерното евклидово пространство R^4

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2000 Mathematics Subject Classification: 53C40, 53B25.

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It is projected that by 2020, there will be 138 million Americans over 45, the age at which the increased incidence of heart diseases is documented. Many will require stents. This multi-billion dollar industry, with over 2 million patients worldwide, 15% of whom use Nitinol stents have experienced a decline in sales recently, due in part to thrombosis. It is a sudden blood clot that forms inside stents. As a result, the Food and Drug Administration and American Heart Association are calling for a new generation of stents, new designs and different alloys that are more adaptable to the arteries. The future of Nitinol therefore depends on a better understanding of the mechanisms by which Nitinol surfaces can be rendered stable and inert. In this investigation, binary and ternary Nitinol alloys were prepared and subjected to various surface treatments such as electropolishing (EP), magnetoelectropolishing (MEP) and water boiling & passivation (W&P). In vitro corrosion tests were conducted on Nitinol alloys in accordance with ASTM F 2129-08. The metal ions released into the electrolyte during corrosion tests were measured by Inductively Coupled Plasma Mass Spectroscopy (ICP-MS). Biocompatibility was assessed by observing the growth of human umbilical vein endothelial cells (HUVEC) on the surface of Nitinol alloys. Static and dynamic immersion tests were performed by immersing the Nitinol alloys in cell culture media and measuring the amount of metal ions released in solution. Sulforhodamine B (SRB) assays were performed to elucidate the effect of metal ions on the growth of HUVEC cells. The surfaces of the alloys were studied using Scanning Electron Microscopy (SEM) and X-ray Photoelectron Spectroscopy (XPS) respectively. Finally, wettability and surface energy were measured by Contact Angle Meter, whereas surface roughness was measured by Atomic Force Microscopy (AFM). All the surface treated alloys exhibited high resistance to corrosion when compared with untreated alloys. SRB assays revealed that Ni and Cu ions exhibited greater toxicity than Cr, Ta and Ti ions on HUVEC cells. EP and MEP alloys possessed relatively smooth surfaces and some were composed of nickel oxides instead of elemental nickel as determined by XPS. MEP exhibited lowest surface energy and lowest surface roughness.

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It is projected that by 2020, there will be 138 million Americans over 45, the age at which the increased incidence of heart diseases is documented. Many will require stents. This multi-billion dollar industry, with over 2 million patients worldwide, 15% of whom use Nitinol stents have experienced a decline in sales recently, due in part to thrombosis. It is a sudden blood clot that forms inside stents. As a result, the Food and Drug Administration and American Heart Association are calling for a new generation of stents, new designs and different alloys that are more adaptable to the arteries. The future of Nitinol therefore depends on a better understanding of the mechanisms by which Nitinol surfaces can be rendered stable and inert. In this investigation, binary and ternary Nitinol alloys were prepared and subjected to various surface treatments such as electropolishing (EP), magnetoelectropolishing (MEP) and water boiling & passivation (W&P). In vitro corrosion tests were conducted on Nitinol alloys in accordance with ASTM F 2129-08. The metal ions released into the electrolyte during corrosion tests were measured by Inductively Coupled Plasma Mass Spectroscopy (ICP-MS). Biocompatibility was assessed by observing the growth of human umbilical vein endothelial cells (HUVEC) on the surface of Nitinol alloys. Static and dynamic immersion tests were performed by immersing the Nitinol alloys in cell culture media and measuring the amount of metal ions released in solution. Sulforhodamine B (SRB) assays were performed to elucidate the effect of metal ions on the growth of HUVEC cells. The surfaces of the alloys were studied using Scanning Electron Microscopy (SEM) and X-ray Photoelectron Spectroscopy (XPS) respectively. Finally, wettability and surface energy were measured by Contact Angle Meter, whereas surface roughness was measured by Atomic Force Microscopy (AFM). All the surface treated alloys exhibited high resistance to corrosion when compared with untreated alloys. SRB assays revealed that Ni and Cu ions exhibited greater toxicity than Cr, Ta and Ti ions on HUVEC cells. EP and MEP alloys possessed relatively smooth surfaces and some were composed of nickel oxides instead of elemental nickel as determined by XPS. MEP exhibited lowest surface energy and lowest surface roughness.

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Hematopoietic stem cell transplantation (HSCT) is the only curative treatment for most children with osteopetrosis (OP). Timing of HSCT is critical; therefore, umbilical cord blood transplantation (UCBT) is an attractive option. We analyzed outcomes after UCBT in 51 OP children. Median age at UCBT was 6 months. Seventy-seven percent of the cord blood grafts had 0 or 1 HLA disparity with the recipient. Conditioning regimen was myeloablative (mostly busulfan-based in 84% and treosulfan-based in 10%). Antithymocyte globulin was given to 90% of patients. Median number of total nucleated and CD34(+) cells infused was 14 × 10(7)/kg and 3.4 × 10(5)/kg, respectively. Median follow-up for survivors was 74 months. Cumulative incidence (CI) of neutrophil recovery was 67% with a median time to recovery of 23 days; 33% of patients had graft failure, 81% of engrafted patients had full donor engraftment, and 19% had mixed donor chimerism. Day 100 CI of acute graft-versus-host disease (grades II to IV) was 31% and 6-year CI of chronic graft-versus-host disease was 21%. Mechanical ventilation was required in 28%, and veno-occlusive disease was diagnosed in 16% of cases. Six-year overall survival rate was 46%. Comparative studies with other alternative donors should be performed to evaluate whether UCBT remains a valid alternative for children with OP without an HLA-matched donor.

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Three closely related human sec14p-like proteins (hTAP1, 2, and 3, or SEC14L2, 3, and 4, respectively) have been described. These proteins may participate in intracellular lipid transport (phospholipids, squalene, tocopherol analogues and derivatives) or influence regulatory lipid-dependent events. Here, we show that the three recombinant hTAP proteins associate with the Golgi apparatus and mitochondria, and enhance the in vitro transport of radioactively labeled α-tocopherol to mitochondria in the same order of magnitude as the human α-tocopherol transfer protein (α-TTP). hTAP1 and hTAP2 are expressed in several cell lines, whereas the expression level of hTAP3 is low. Expression of hTAP1 is induced in human umbilical cord blood-derived mast cells upon differentiation by interleukin 4. In tissues, the three hTAPs are detectable ubiquitously at low level; pronounced and localized expression is found for hTAP2 and hTAP3 in the perinuclear region in cerebellum, lung, liver and adrenal gland. hTAP3 is well expressed in the epithelial duct cells of several glands, in ovary in endothelial cells of small arteries as well as in granulosa and thecal cells, and in testis in Leydig cells. Thus, the three hTAPs may mediate lipid uptake, secretion, presentation, and sub-cellular localization in a tissue-specific manner, possibly using organelle- and enzyme-specific docking sites.

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Con un diseño experimental se realizó un estudio clínico, controlado, aleatorizado La muestra incluyó 200 pacientes, el grupo experimental comprendió 100 pacientes en las que se drenó la sangre de cordón umbilical 50 anémicas y 50 no anémicas, y el grupo de control con pinzamiento del cordón lo integraron 100 pacientes, 50 anémicas y 50 no anémicas. Resultados: al comparar la duración del tercer período del parto del grupo con drenaje se obtuvo una media de 4,6 ñ 1,4 min y en el grupo con pinzamiento 9,07 ñ 2,5 min. La diferencia fue significativa (P = 0,0001).Cuando se comparó la duración del tercer período del parto de 1 a 5 min vs 6 a 10 min, la mayoría de las pacientes del grupo con drenaje, estuvo entre 1 a 5 min, con un RR 0.239 (IC 95: 0.188 - 0.358), RRA 70.1, RRR 76.1, NNT 1.426, en las anémicas, y un RR 0.250 (IC 95: 0.179 - 0.383), RRA 66.1, RRR 75, NNT 1.513 en las no anémicas. El volumen de drenaje en el grupo de estudio, tuvo una media de 60.3 ñ 19.5 ml en las anémicas y 56.9 ñ 18 ml en las no anémicas (P = 0.369). La hemorragia del tercer período del parto del grupo con drenaje tuvo una media de 197.6 ñ 36 ml vs el grupo con pinzamiento 277.4 ñ 49 ml con un valor (P = 0,0001) lo cual es estadísticamente significativo a favor del drenaje. Cuando se comparó la hemorragia del tercer período del parto de menor que 250 ml vs 250 a 500 ml la mayoría de las pacientes del grupo con drenaje, estuvo en menor que 250 ml, con un RR 0.070 (IC 95: 0.025 - 0.168), RRA 80, RRR 93, NNT 1.25, en las anémicas, y un RR 0.074 (IC 95: 0.020 - 0.246), RRA 50, RRR 92.6, NNT 2 en las no anémicas. Conclusiones. La maniobra del drenaje de sangre del cordón umbilical reduce el tiempo y la hemorragia del tercer período del parto en pacientes con anemia leve y no anémicas sin producir efectos deletéreos