Microfluidic technology in vascular research : the endothelial response to shear stress

Vascular endothelial cells form the inner lining of all blood vessels. These cells are highly responsive to the shear stress that is caused by blood flowing over their surface. In this thesis, several aspects of the endothelial response to shear stress are studied. The experiments focus on signal transduction, cytoskeletal remodeling, migration, micromechanical changes and uptake of low density lipoprotein. Most of these experiments were performed by using microfluidic set-ups. In these set-ups, cells are cultured and subjected to experimental conditions in micrometer-sized channels. Several advantages and challenges associated with applying this new technology in vascular research are discussed

Flow focusing through gels as a tool to generate 3D concentration profiles in hydrogel-filled microfluidic chips

Laminar flow patterning is an iconic microfluidic technology used to deliver chemicals to specific regions on a two-dimensional surface with high spatial fidelity. Here we present a novel extension of this technology using Darcy flow within a three-dimensional (3D) hydrogel. Our test device is a simple 3-inlet microfluidic channel, totally filled with collagen, a cured biological hydrogel, where the concentration profiles of solutes are manipulated via the inlet pressures. This method allows solutes to be delivered with 50 micron accuracy within the gel, as we evidence by controlling concentration profiles of 40 kDa and 1 kDa fluorescent polysaccharide dyes. Furthermore, we design and test a 3D-printed version of our device with an extra two inlets for control of the vertical position of the concentration profile, demonstrating that this method is easily extensible to control of the concentration profile in 3D

Randomized controlled trial on cardiovascular risk management by practice nurses supported by self-monitoring in primary care

BACKGROUND: Treatment goals for cardiovascular risk management are generally not achieved. Specialized practice nurses are increasingly facilitating the work of general practitioners and self-monitoring devices have been developed as counseling aid. The aim of this study was to compare standard treatment supported by self-monitoring with standard treatment without self-monitoring, both conducted by practice nurses, on cardiovascular risk and separate risk factors. METHODS: Men aged 50–75 years and women aged 55–75 years without a history of cardiovascular disease or diabetes, but with a SCORE 10-year risk of cardiovascular mortality ≥5% and at least one treatable risk factor (smoking, hypertension, lack of physical activity or overweight), were randomized into two groups. The control group received standard treatment according to guidelines, the intervention group additionally received pro-active counseling and self-monitoring (pedometer, weighing scale and/ or blood pressure device). After one year treatment effect on 179 participants was analyzed. RESULTS: SCORE risk assessment decreased 1.6% (95% CI 1.0–2.2) for the control group and 1.8% (1.2–2.4) for the intervention group, difference between groups was .2% (−.6–1.1). Most risk factors tended to improve in both groups. The number of visits was higher and visits took more time in the intervention group (4.9 (SD2.2) vs. 2.6 (SD1.5) visits p < .001 and 27 (P(25) –P(75):20–33) vs. 23 (P(25) –P(75):19–30) minutes/visit p = .048). CONCLUSIONS: In both groups cardiovascular risk decreased significantly after one year of treatment by practice nurses. No additional effect of basing the pro-active counseling on self-monitoring was found, despite the extra time investment. TRIAL REGISTRATION: trialregister.nl NTR218

Evaluation of ear, nose, and throat-screening in liver transplantation candidates:A retrospective cohort study

Background:Patients with end-stage liver disease can be treated with a liver transplantation (LT). Before listing, candidates are subjected to a screening procedure according to the EASL Clinical Practice Guidelines for LT. In our hospital, this includes an ear, nose, and throat (ENT) examination, directed towards the identification of (asymptomatic) infections and head and neck malignancies.Methods:We retrospectively reviewed all ENT screening examinations in LT candidates from 2007 to 2022. The screening consisted of a visit to the ENT outpatient clinic combined with sinus radiography.Results:ENT screening was performed in 1099 patients. Sixty-one cases were identified, either diagnosed with an infection (n = 58, almost exclusively sinusitis) or a neoplasm (n = 3, of which two malignancies). With binary logistic regression, we could not identify significant risk factors for diagnosing sinusitis. 711 patients underwent LT. After LT, two patients developed a novel malignancy of the head and neck area, while 14 patients were diagnosed with sinusitis, two of the latter already showed opacification on sinus radiography during screening. Despite immunosuppressive drugs, no complicated sinusitis was observed.Conclusion:Sinusitis or a neoplasm was diagnosed in almost 6% in a large cohort of LT candidates. Although almost a third of sinusitis patients were not treated accordingly, we did not observe any complicated sinusitis after LT. A more conservative approach to sinusitis may therefore be justified in LT candidates, especially in asymptomatic cases. At our institution, we aim to refer only those patients with specific ENT complaintsimage.This study aimed to evaluate the outcome of routine ear, nose, and throat screening in a large cohort of liver transplantation candidates. Note that, 6% were diagnosed with either sinusitis or a neoplasm. We did not observe any complicated sinusitis after transplantation. A more conservative approach may therefore be justified, especially in asymptomatic cases.imag

Evaluation of ear, nose, and throat-screening in liver transplantation candidates:A retrospective cohort study

Background:Patients with end-stage liver disease can be treated with a liver transplantation (LT). Before listing, candidates are subjected to a screening procedure according to the EASL Clinical Practice Guidelines for LT. In our hospital, this includes an ear, nose, and throat (ENT) examination, directed towards the identification of (asymptomatic) infections and head and neck malignancies.Methods:We retrospectively reviewed all ENT screening examinations in LT candidates from 2007 to 2022. The screening consisted of a visit to the ENT outpatient clinic combined with sinus radiography.Results:ENT screening was performed in 1099 patients. Sixty-one cases were identified, either diagnosed with an infection (n = 58, almost exclusively sinusitis) or a neoplasm (n = 3, of which two malignancies). With binary logistic regression, we could not identify significant risk factors for diagnosing sinusitis. 711 patients underwent LT. After LT, two patients developed a novel malignancy of the head and neck area, while 14 patients were diagnosed with sinusitis, two of the latter already showed opacification on sinus radiography during screening. Despite immunosuppressive drugs, no complicated sinusitis was observed.Conclusion:Sinusitis or a neoplasm was diagnosed in almost 6% in a large cohort of LT candidates. Although almost a third of sinusitis patients were not treated accordingly, we did not observe any complicated sinusitis after LT. A more conservative approach to sinusitis may therefore be justified in LT candidates, especially in asymptomatic cases. At our institution, we aim to refer only those patients with specific ENT complaintsimage.This study aimed to evaluate the outcome of routine ear, nose, and throat screening in a large cohort of liver transplantation candidates. Note that, 6% were diagnosed with either sinusitis or a neoplasm. We did not observe any complicated sinusitis after transplantation. A more conservative approach may therefore be justified, especially in asymptomatic cases.imag