Hypoxia Impairs Initial Outgrowth of Endothelial Colony Forming Cells and Reduces Their Proliferative and Sprouting Potential

Vascular homeostasis and regeneration in ischemic tissue relies on intrinsic competence of the tissue to rapidly recruit endothelial cells for vascularization. The mononuclear cell (MNC) fraction of blood contains circulating progenitors committed to endothelial lineage. These progenitors give rise to endothelial colony-forming cells (ECFCs) that actively participate in neovascularization of ischemic tissue. To evaluate if the initial clonal outgrowth of ECFCs from cord (CB) and peripheral blood (PB) was stimulated by hypoxic conditions, MNCs obtained from CB and PB were subjected to 20 and 1% O2 cell culture conditions. Clonal outgrowth was followed during a 30 day incubation period. Hypoxia impaired the initial outgrowth of ECFC colonies from CB and also reduced their number that were developing from PB MNCs. Three days of oxygenation (20% O2) prior to hypoxia could overcome the initial CB-ECFC outgrowth. Once proliferating and subcultured the CB-ECFCs growth was only modestly affected by hypoxia; proliferation of PB-ECFCs was reduced to a similar extent (18–30% reduction). Early passages of subcultured CB- and PB-ECFCs contained only viable cells and few if any senescent cells. Tube formation by subcultured PB-ECFCs was also markedly inhibited by continuous exposure to 1% O2. Gene expression profiles point to regulation of the cell cycle and metabolism as major altered gene clusters. Finally we discuss our counterintuitive observations in the context of the important role that hypoxia has in promoting neovascularization

CFD simulation of wind forces on ships in ports: Case study for the Rotterdam Cruise Terminal

A nautical port is an aerodynamically complex built-up area. The wind forces on ships in ports can be very different from those at open sea. Knowledge of the wind conditions in ports and of the wind forces acting on ships in ports are essential for safe maneuvering and mooring. This paper presents a case study in which wind forces on a large cruise ship moored at the quay of the Rotterdam Cruise Terminal are determined by 3D steady RANS simulations. The simulated wind speeds and wind directions are validated by on-site measurements. A previous study in which simulated wind forces on a container ship were validated with wind-tunnel tests, is also mentioned here to justify the selection of computational parameters for the case study. Near to the Cruise Terminal quay various high-rise buildings exist that can influence the wind loads on the ship. It is shown that the presence of the high-rise buildings can yield locally amplified surface pressure, but that, due to the large size of the ship, the net horizontal force decreases. However, the net vertical upward force increases. For smaller ships, nearby high-rise buildings could yield an increase in both horizontal and vertical forces

Original Article Assessment of the clinical relevance of quantitative sensory testing with Von Frey monofilaments in patients with allodynia and neuropathic pain. A pilot study

Take-down policy If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim. Downloaded from the University of Groningen/UMCG research database (Pure): http://www.rug.nl/research/portal. For technical reasons the number of authors shown on this cover page is limited to 10 maximum. Summary Background: Allodynia is a common and disabling symptom in many patients with neuropathic pain. Whereas quantification of pain mostly depends on subjective pain reports, allodynia can also be measured objectively with quantitative sensory testing. In this pilot study, we investigated the clinical relevance of quantitative sensory testing with Von Frey monofilaments in patients with allodynia as a consequence of a neuropathic pain syndrome, by means of correlating subjective pain scores with pain thresholds obtained with quantitative sensory testing. Methods: During a 4-week trial, we administered a cannabis extract to 17 patients with allodynia. We quantified the severity of the allodynia with Von Frey monofilaments before, during and after the patients finished the trial. We also asked the patients to rate their pain on a numeric rating scale at these three moments. Results: We found that most of the effect of the cannabis occurred in the last 2 weeks of the trial. In this phase, we observed that the pain thresholds, as measured with Von Frey monofilaments, were inversely correlated with a decrease of the perceived pain intensity. Conclusion: These preliminary findings indicate clinical relevance of quantitative sensory testing with Von Frey monofilaments in the quantification of allodynia in patients with neuropathic pain, although confirmation of our data is still required in further studies to position this method of quantitative sensory testing as a valuable tool, for example, in the evaluation of therapeutic interventions for neuropathic pain. Download date: 30-06-2019 European Journal of Anaesthesiology 2007; 24: 658-663 r 2007 Copyright European Society of Anaesthesiology doi: 10.101

A randomized clinical trial of living donor nephrectomy: a plea for a differentiated appraisal of mini-open muscle splitting incision and hand-assisted laparoscopic donor nephrectomy.

A randomized controlled trial was designed to compare various outcome variables of the retroperitoneal mini-open muscle splitting incision (MSI) technique and the transperitoneal hand-assisted laparoscopic technique (HAL) in performing living donor nephrectomies. Fifty living kidney donors were randomized to MSI or HAL. Primary endpoint was pain experience scored on a visual analogue scale (VAS). After MSI living donors indicated lower median (range) VAS scores at rest than HAL living donors on postoperative day 2.5 [10 (0-44) vs. 15 (0-70), P = 0.043] and day 3 [7 (0-28) vs. 10 (0-91), P = 0.023] and lower VAS scores while coughing on postoperative day 3 [20 (0-73) vs. 42 (6-86), P = 0.001], day 7 [8 (0-66) vs. 33 (3-76), P < 0.001] and day 14 [2 (0-17) vs. 12 (0-51), P = 0.009]. The MSI technique also resulted in reduced morphine requirement, better scores on three domains of the RAND-36, reduced costs and reduced CRP and IL-6 levels. The HAL technique was superior in operating time and postoperative decrease of hemoglobin level. The MSI technique is superior to the HAL technique in performing living donor nephrectomies with regard to postoperative pain experience. This study reopens the discussion of the way to go in performing the living donor nephrectomy

CD34 expression modulates tube-forming capacity and barrier properties of peripheral blood-derived endothelial colony-forming cells (ECFCs)

Endothelial colony-forming cells (ECFC) are grown from circulating CD34(+) progenitors present in adult peripheral blood, but during in vitro expansion part of the cells lose CD34. To evaluate whether the regulation of CD34 characterizes the angiogenic phenotypical features of PB-ECFCs, we investigated the properties of CD34(+) and CD34(−) ECFCs with respect to their ability to form capillary-like tubes in 3D fibrin matrices, tip-cell gene expression, and barrier integrity. Selection of CD34(+) and CD34(−) ECFCs from subcultured ECFCs was accomplished by magnetic sorting (FACS: CD34(+): 95 % pos; CD34(−): 99 % neg). Both fractions proliferated at same rate, while CD34(+) ECFCs exhibited higher tube-forming capacity and tip-cell gene expression than CD3(4−) cells. However, during cell culture CD34(−) cells re-expressed CD34. Cell-seeding density, cell–cell contact formation, and serum supplements modulated CD34 expression. CD34 expression in ECFCs was strongly suppressed by newborn calf serum. Stimulation with FGF-2, VEGF, or HGF prepared in medium supplemented with 3 % albumin did not change CD34 mRNA or surface expression. Silencing of CD34 with siRNA resulted in strengthening of cell–cell contacts and increased barrier function of ECFC monolayers as measured by ECIS. Furthermore, CD34 siRNA reduced tube formation by ECFC, but did not affect tip-cell gene expression. These findings demonstrate that CD34(+) and CD34(−) cells are different phenotypes of similar cells and that CD34 (1) can be regulated in ECFC; (2) is positively involved in capillary-like sprout formation; (3) is associated but not causally related to tip-cell gene expression; and (4) can affect endothelial barrier function. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s10456-016-9506-9) contains supplementary material, which is available to authorized users