300 research outputs found

    Characteristic values of the lumbar load of manual patient handling for the application in workers' compensation procedures

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    <p>Abstract</p> <p>Background</p> <p>The human spine is often exposed to mechanical load in vocational activities especially in combination with lifting, carrying and positioning of heavy objects. This also applies in particular to nursing activities with manual patient handling. In the present study a detailed investigation on the load of the lumbar spine during manual patient handling was performed.</p> <p>Methods</p> <p>For a total of 13 presumably endangering activities with transferring a patient, the body movements performed by healthcare workers were recorded and the exerted action forces were determined with regard to magnitude, direction and lateral distribution in the time course with a "measuring bed", a "measuring chair" and a "measuring floor". By the application of biomechanical model calculations the load on the lowest intervertebral disc of the lumbar spine (L5-S1) was determined considering the posture and action force data for every manual patient handling.</p> <p>Results</p> <p>The results of the investigations reveal the occurrence of high lumbar load during manual patient handling activities, especially in those cases, where awkward postures of the healthcare worker are combined with high action forces caused by the patient's mass. These findings were compared to suitable issues of corresponding investigations provided in the literature. Furthermore measurement-based characteristic values of lumbar load were derived for the use in statement procedures concerning the disease no. 2108 of the German list of occupational diseases.</p> <p>Conclusions</p> <p>To protect healthcare workers from mechanical overload and the risk of developing a disc-related disease, prevention measures should be compiled. Such measures could include the application of "back-fairer" nursing techniques and the use of "technical" and" small aids" to reduce the lumbar load during manual patient handling. Further studies, concerning these aspects, are necessary.</p

    Intravenous Sphingosylphosphorylcholine Protects Ischemic and Postischemic Myocardial Tissue in a Mouse Model of Myocardial Ischemia/Reperfusion Injury

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    HDL, through sphingosine-1-phosphate (S1P), exerts direct cardioprotective effects on ischemic myocardium. It remains unclear whether other HDL-associated sphingophospholipids have similar effects. We therefore examined if HDL-associated sphingosylphosphorylcholine (SPC) reduces infarct size in a mouse model of transient myocardial ischemia/reperfusion. Intravenously administered SPC dose-dependently reduced infarct size after 30 minutes of myocardial ischemia and 24 hours reperfusion compared to controls. Infarct size was also reduced by postischemic, therapeutical administration of SPC. Immunohistochemistry revealed reduced polymorphonuclear neutrophil recruitment to the infarcted area after SPC treatment, and apoptosis was attenuated as measured by TUNEL. In vitro, SPC inhibited leukocyte adhesion to TNFα-activated endothelial cells and protected rat neonatal cardiomyocytes from apoptosis. S1P3 was identified as the lysophospholipid receptor mediating the cardioprotection by SPC, since its effect was completely absent in S1P3-deficient mice. We conclude that HDL-associated SPC directly protects against myocardial reperfusion injury in vivo via the S1P3 receptor

    Pharmacological inhibition of protein tyrosine kinases axl and fyn reduces TNF-α-induced endothelial inflammatory activation in vitro

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    Major surgery induces systemic inflammation leading to pro-inflammatory activation of endothelial cells. Endothelial inflammation is one of the drivers of postoperative organ damage, including acute kidney injury Tumour Necrosis Factor alpha (TNF-α) is an important component of surgery-induced pro-inflammatory activation of endothelial cells. Kinases, the backbone of signalling cascades, can be targeted by pharmacological inhibition. This is a promising treatment option to interfere with excessive endothelial inflammation. In this study, we identified activated kinases as potential therapeutic targets. These targets were pharmacologically inhibited to reduce TNF-α-induced pro-inflammatory signalling in endothelial cells. Kinome profiling using PamChip arrays identified 64 protein tyrosine kinases and 88 serine-threonine kinases, the activity of which was determined at various timepoints (5–240 min) following stimulation with 10 ng/ml TNF-α in Human umbilical vein endothelial cells in vitro. The PTKs Axl and Fyn were selected based on high kinase activity profiles. Co-localisation experiments with the endothelial-specific protein CD31 showed Axl expression in endothelial cells of glomeruli and Fyn in arterioles and glomeruli of both control and TNF-α-exposed mice. Pharmacological inhibition with Axl inhibitor BMS-777607 and Fyn inhibitor PP2 significantly reduced TNF-α-induced pro-inflammatory activation of E-selectin, VCAM-1, ICAM-1, IL-6 and IL-8 at mRNA and VCAM-1, ICAM-1, and IL-6 at protein level in HUVEC in vitro. Upon pharmacological inhibition with each inhibitor, leukocyte adhesion to HUVEC was also significantly reduced, however to a minor extent. In conclusion, pre-treatment of endothelial cells with kinase inhibitors BMS-777607 and PP2 reduces TNF-α-induced endothelial inflammation in vitro

    Sequential Surgical Procedures in Vascular Surgery Patients Are Associated With Perioperative Adverse Cardiac Events

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    Patients at elevated cardiovascular risk are prone to perioperative cardiovascular complications, like myocardial injury after non-cardiac surgery (MINS). We have demonstrated in a mouse model of atherosclerosis that perioperative stress leads to an increase in plaque volume and higher plaque vulnerability. Regulatory T cells (Tregs) play a pivotal role in development and destabilization of atherosclerotic plaques. For this exploratory post-hoc analysis we identified 40 patients recruited into a prospective perioperative biomarker study, who within the inclusion period underwent sequential open vascular surgery. On the basis of protein markers measured in the biomarker study, we evaluated the perioperative inflammatory response in patients' plasma before and after index surgery as well as before and after a second surgical procedure. We also analyzed available immunohistochemistry samples to describe plaque vulnerability in patients who underwent bilateral carotid endarterectomy (CEA) in two subsequent surgical procedures. Finally, we assessed if MINS was associated with sequential surgery. The inflammatory response of both surgeries was characterized by postoperative increases of interleukin-6,−10, Pentraxin 3 and C-reactive protein with no clear-cut difference between the two time points of surgery. Plaques from CEA extracted during the second surgery contained less Tregs, as measured by Foxp3 staining, than plaques from the first intervention. The 2nd surgical procedure was associated with MINS. In conclusion, we provide descriptive evidence that sequential surgical procedures involve repeat inflammation, and we hypothesize that elevated rates of cardiovascular complications after the second procedure could be related to reduced levels of intraplaque Tregs, a finding that deserves confirmatory testing and mechanistic exploration in future populations

    Mouse Plasminogen Has Oxidized Phosphatidylcholine Adducts That Are Not Metabolized by Lipoprotein-Associated Phospholipase A2 under Basal Conditions

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    We previously showed that plasminogen (Plg) isolated from the plasma of normal human subjects contains 1–2 moles of oxidized phosphatidylcholine (oxPtdPC) adducts/mole of protein. Moreover, we suggested that these species are generated at the hepatic site and speculated that they may play a role in the reported cardiovascular pathogenicity of Plg. We aimed to determine whether mouse Plg also harbors linked oxPtdPCs and whether these molecules are metabolized by lipoprotein-associated phospholipase A2/PAF acetylhydrolase (Lp-PLA2/PAF-AH), an enzyme specific for hydrolysis of oxPtdPCs. We determined the total concentration of Plg in plasma samples from control (WT) and Lp-PLA2-deficient (KO) mice, we isolated Plg, and assessed its content of oxPtdPCs by immunoblot analyses. We also evaluated whether human recombinant Lp-PLA2 metabolized Plg-linked oxPtdPCs in vivo and in vitro. WT and KO mice expressed comparable levels (14.4–15.8 mg/dL) of plasma Plg, as determined by ELISA. We observed no differences in the content of oxPtdPC in Plg isolated from the two mouse strains and in parallel no changes in oxPtdPC content in mouse Plg following incubation with pure recombinant Lp-PLA2. Plg from mouse plasma contains oxPtdPC adducts that are not affected by the action of Lp-PLA2, suggesting that linkage to Plg protects oxPtdPCs from metabolism during their transport in the plasma. This modification may have important physio-pathological implications related to the function of Plg, oxPtdPCs, or both

    Acute perioperative-stress-induced increase of atherosclerotic plaque volume and vulnerability to rupture in apolipoprotein-E-deficient mice is amenable to statin treatment and IL-6 inhibition

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    Myocardial infarction and stroke are frequent after surgical procedures and consume a considerable amount of benefit of surgical therapy. Perioperative stress, induced by surgery, is composed of hemodynamic and inflammatory reactions. The effects of perioperative stress on atherosclerotic plaques are ill-defined. Murine models to investigate the influence of perioperative stress on plaque stability and rupture are not available. We developed a model to investigate the influence of perioperative stress on plaque growth and stability by exposing apolipoprotein-E-deficient mice, fed a high cholesterol diet for 7 weeks, to a double hit consisting of 30 min of laparotomy combined with a substantial blood loss (approximately 20% of total blood volume; 400 µl). The innominate artery was harvested 72 h after the intervention. Control groups were sham and baseline controls. Interleukin-6 (IL-6) and serum amyloid A (SAA) plasma levels were determined. Plaque load, vascular smooth muscle cell (VSMC) and macrophage content were quantified. Plaque stability was assessed using the Stary score and frequency of signs of plaque rupture were assessed. High-dose atorvastatin (80 mg/kg body weight/day) was administered for 6 days starting 3 days prior to the double hit. A single dose of an IL-6-neutralizing antibody or the fusion protein gp130-Fc selectively targeting IL-6 trans-signaling was subcutaneously injected. IL-6 plasma levels increased, peaking at 6 h after the intervention. SAA levels peaked at 24 h (n=4, P<0.01). Plaque volume increased significantly with the double hit compared to sham (n=8, P<0.01). More plaques were scored as complex or bearing signs of rupture after the double hit compared to sham (n=5-8, P<0.05). Relative VSMC and macrophage content remained unchanged. IL-6-inhibition or atorvastatin, but not blocking of IL-6 trans-signaling, significantly decreased plaque volume and complexity (n=8, P<0.01). Using this model, researchers will be able to further investigate the pathophysiology of perioperative plaque stability, which can result in myocardial infarction, and, additionally, to test potential protective strategies

    The Lectin-like Domain of Thrombomodulin Confers Protection from Neutrophil-mediated Tissue Damage by Suppressing Adhesion Molecule Expression via Nuclear Factor κB and Mitogen-activated Protein Kinase Pathways

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    Thrombomodulin (TM) is a vascular endothelial cell (EC) receptor that is a cofactor for thrombin-mediated activation of the anticoagulant protein C. The extracellular NH2-terminal domain of TM has homology to C-type lectins that are involved in immune regulation. Using transgenic mice that lack this structure (TMLeD/LeD), we show that the lectin-like domain of TM interferes with polymorphonuclear leukocyte (PMN) adhesion to ECs by intercellular adhesion molecule 1–dependent and –independent pathways through the suppression of extracellular signal–regulated kinase (ERK)1/2 activation. TMLeD/LeD mice have reduced survival after endotoxin exposure, accumulate more PMNs in their lungs, and develop larger infarcts after myocardial ischemia/reperfusion. The recombinant lectin-like domain of TM suppresses PMN adhesion to ECs, diminishes cytokine-induced increase in nuclear factor κB and activation of ERK1/2, and rescues ECs from serum starvation, findings that may explain why plasma levels of soluble TM are inversely correlated with cardiovascular disease. These data suggest that TM has antiinflammatory properties in addition to its role in coagulation and fibrinolysis

    Zinc deficiency decreased cell viability both in endothelial EA.hy926 cells and mouse aortic culture ex vivo and its implication for anti-atherosclerosis

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    Zinc plays a protective role in anti-atherosclerosis but the clear mechanism has not been proposed yet. In the present study, we evaluated whether zinc modulates atherosclerotic markers, VACM-1 and ICAM-1 and cell viability both in endothelial cells in vitro and mouse aortic cell viability ex vivo. In study 1, as in vitro model, endothelial EA.hy926 cells were treated with TNFα for 5 hours for inducing oxidative stress, and then treated with Zn-adequacy (15 µM Zn) or Zn-deficiency (0 µM Zn) for 6 hours. Pro-atherosclerosis factors, VCAM-1 and ICAM-1 mRNA expression and cell viability was measured. In study 2, as ex vivo model, mouse aorta ring was used. Mourse aorta was removed and cut in ring then, cultured in a 96-well plate. Aortic ring was treated with various TNFα (0-30 mg/ml) and intracellular zinc chelator, N, N, N', N', -tetrakis (2-pyridylmethyl) ethylenediamine (TPEN, 0-30 µM) for cellular zinc depletion for 2 days and then cell viability was measured. The results showed that in in vitro study, Zn-adequate group induced more VCAM-1 & ICAM-1 mRNA expression than Zn-deficient group during 6-hour zinc treatment post-5 hour TNF-α treatment, unexpectedly. These results might be cautiously interpreted that zinc would biologically induce the early expression of anti-oxidative stress through the increased adhesion molecule expression for reducing atherosclerotic action, particularly under the present 6-hour zinc treatment. In ex vivo, mouse aortic ring cell viability was decreased as TNF-α and TPEN levels increased, which suggests that mouse aortic blood vessel cell viability was decreased, when oxidative stress increases and cellular zinc level decreases. Taken together, it can be suggested that zinc may have a protective role in anti-atherosclerosis by cell viability in endothelial cells and aorta tissue. Further study is needed to clarify how pro-atherosclerosis molecule expression is modulated by zinc

    The Proteoglycan Syndecan 4 Regulates Transient Receptor Potential Canonical 6 Channels via RhoA/Rho-associated Protein Kinase Signaling

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    Syndecan 4 (Sdc4) modulates signal transduction and regulates activity of protein channels. Sdc4 is essential for the regulation of cellular permeability. We hypothesized that Sdc4 may regulate transient receptor potential canonical 6 (TRPC6) channels, a determinant of glomerular permeability, in a RhoA/Rho-associated protein kinase-dependent manner

    Microparticles from apoptotic platelets promote resident macrophage differentiation

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    Platelets shed microparticles not only upon activation, but also upon ageing by an apoptosis-like process (apoptosis-induced platelet microparticles, PMap). While the activation-induced microparticles have widely been studied, not much is known about the (patho)physiological consequences of PMap formation. Flow cytometry and scanning electron microscopy demonstrated that PMap display activated integrins and interact to form microparticle aggregates. PMap were chemotactic for monocytic cells, bound to these cells, an furthermore stimulated cell adhesion and spreading on a fibronectin surface. After prolonged incubation, PMap promoted cell differentiation, but inhibited proliferation. Monocyte membrane receptor analysis revealed increased expression levels of CD11b (integrin αMβ2), CD14 and CD31 (platelet endothelial cell adhesion molecule-1), and the chemokine receptors CCR5 and CXCR4, but not of CCR2. This indicated that PMap polarized the cells into resident M2 monocytes. Cells treated with PMap actively consumed oxidized low-density lipoprotein (oxLDL), and released matrix metalloproteinases and hydrogen peroxide. Further confirmation for the differentiation towards resident professional phagocytes came from the finding that PMap stimulated the expression of the (ox)LDL receptors, CD36 and CD68, and the production of proinflammatory and immunomodulating cytokines by monocytes. In conclusion, interaction of PMap with monocytic cells has an immunomodulating potential. The apoptotic microparticles polarize the cells into a resident M2 subset, and induce differentiation to resident professional phagocytes
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