Carotid artery stiffness in metabolic syndrome: Sex differences

Introduction: The effect of metabolic syndrome (MS) on carotid stiffness (CS) in the context of gender is under research. Objective: We examined the relationship between the MS and CS in men (M) and women (W) and investigated if the impact of cardiovascular risk factors on CS is modulated by gender. Patients and Methods: The study included 419 subjects (mean age 54.3 years): 215 (51%) with MS (109 W and 106 M) and 204 (49%) without MS (98 W and 106 M). Carotid intima-media thickness (IMT) and CS parameters (beta stiffness index (beta), Peterson’s elastic modulus (Ep), arterial compliance (AC) and one-point pulse wave velocity (PWV-beta)) were measured with the echo-tracking (eT) system. Results: ANCOVA demonstrated that MS was associated with elevated CS indices (p = 0.003 for beta and 0.025 for PWV-beta), although further sex-specific analysis revealed that this relationship was significant only in W (p = 0.021 for beta). Age was associated with CS in both M and W, pulse pressure (PP) and body mass index turned out to be determinants of CS solely in W, while the effect of mean arterial pressure (MAP) and heart rate was more pronounced in M. MANOVA performed in subjects with MS revealed that age and diabetes mellitus type 2 were determinants of CS in both sexes, diastolic blood pressure and MAP – solely in M and systolic blood pressure, PP and waist circumference – solely in W (the relationship between the waist circumference and AC was paradoxical). Conclusion: The relationship between MS and CS is stronger in W than in M. In subjects with MS, various components of arterial pressure exert different sex-specific effects on CS – with the impact of the pulsative component of arterial pressure (PP) observed in W and the impact of the steady component (MAP) observed in M

Beech Leaves Briquettes’ and Standard Briquettes’ Combustion: Comparison of Flue Gas Composition

Biomass stoves are not only popular, widespread and important sources of heat but are also not negligible sources of pollutants. The present study had two objectives in this field of research. The first one was to determine the difference between standard wooden and beech leaves briquettes flue gas composition during similar, standard home combustion conditions. The second objective was to determine the possibility of decreasing the mass concentration of pollutants contained in the flue gas produced by standard and alternative fuel combustion, i.e. wooden briquettes and beech leaves briquettes, by an oxidation catalyst. Significantly higher mass concentration of nitrogen oxides (NOx), almost 2.5 times higher, in the flue gas was observed during the beech leaves combustion. Both fuels reached the edge of actual legislation limit (European Standard Commission regulation [EU] 2015/1185) in case of mass concentration of carbon monoxide (CO). This issue was solved by a palladium-based catalyst with average degree of conversion around 82%. The catalyst also influences flue gas composition from mass concentration of propane point of view with average degree of conversion around 15%. The mass fraction of sulphur, occurring in the beech leaves briquettes, did not cause any issue to the catalyst in terms of its degree of CO conversion. Due to the test results from the beech leaves briquettes, i.e. high mass fraction of ash and high mass concentration of NOx in the flue gas, it is appropriate to use this kind of fuel as secondary fuel during the co-combustion process.This work was supported by the Doctoral grant competition VŠB TU-Ostrava, reg. no. CZ.0 2.2.69/0.0./0.0/19_073/0016945 within the Operational Programme Research, Development and Education, under project DGS/TEAM/2020-035 "Determination of oxidation catalysts characteristics during the flue gas purification"

Mouse and human islets survive and function after coating by biosilicification

Inorganic materials have properties that can be advantageous in bioencapsulation for cell transplantation. Our aim was to engineer a hybrid inorganic/soft tissue construct by inducing pancreatic islets to grow an inorganic shell. We created pancreatic islets surrounded by porous silica, which has potential application in the immunoprotection of islets in transplantation therapies for type 1 diabetes. The new method takes advantage of the islet capsule surface as a template for silica formation. Mouse and human islets were exposed to medium containing saturating silicic acid levels for 9-15 min. The resulting tissue constructs were then cultured for up to 4 wk under normal conditions. Scanning electron microscopy and energy dispersive X-ray spectroscopy was used to monitor the morphology and elemental composition of the material at the islet surface. A cytokine assay was used to assess biocompatibility with macrophages. Islet survival and function were assessed by confocal microscopy, glucose-stimulated insulin release assays, oxygen flux at the islet surface, expression of key genes by RT-PCR, and syngeneic transplant into diabetic mice

Regulation of lymphatic capillary regeneration by interstitial flow in skin

Decreased interstitial flow (IF) in secondary lymphedema is coincident with poor physiological lymphatic regeneration. However, both the existence and direction of causality between IF and lymphangiogenesis remain unclear. This is primarily because the role of IF and its importance relative to the action of the prolymphangiogenic growth factor vascular endothelial growth factor (VEGF)-C (which signals primarily through its receptor VEGFR-3) are poorly understood. To clarify this, we explored the cooperative roles of VEGFR-3 and IF in a mouse model of lymphangiogenesis in regenerating skin. Specifically, a region of lymphangiogenesis was created by substituting a portion of mouse tail skin with a collagen gel within which lymphatic capillaries completely regenerate over a period of 60 days. The relative importance of IF and VEGF-C signaling were evaluated by either inhibiting VEGFR-3 signaling with antagonistic antibodies or by reducing IF. In some cases, VEGF-C signaling was then increased with exogenous protein. To clarify the role of IF, the distribution of endogenous matrix metalloproteinases (MMPs) and VEGF-C within the regenerating region was determined. It was found that inhibition of either VEGFR-3 or IF suppressed endogenous lymphangiogenesis. Reduction of IF was found to decrease lymphatic migration and transport of endogenous MMP and VEGF-C through the regenerating region. Therapeutic VEGF-C administration restored lymphangiogenesis following inhibition of VEGFR-3 but did not increase lymphangiogenesis following inhibition of IF. These results identify IF as an important regulator of the pro-lymphangiogenic action of VEGF-C

Splenic size after division of the short gastric vessels in Nissen fundoplication in children

Item does not contain fulltextPURPOSE: Nissen fundoplication is an effective treatment for gastro-esophageal reflux disease (GERD). Mobilization of the gastric fundus during fundoplication requires division of short gastric vessels of the spleen, which may cause splenic ischemia. The aim of this study was to determine if Nissen fundoplication results in hypotrophy of the spleen. METHODS: We performed pre-operative and post-operative ultrasound measurements of the spleen in children undergoing Nissen fundoplication. During operation, the surgeon estimated the compromised blood flow by assessment of the percentage of discoloration of the spleen. RESULTS: Twenty-four consecutive children were analyzed. Discoloration of the upper pole of the spleen was observed in 11 patients (48%) of a median estimated splenic surface of 20% (range 5-50%). The median ratio for pre-operative and post-operative length, width, and area of the spleen was 0.97, 1.03, and 0.96, respectively. The percentage of the estimated perfusion defect during surgery was not correlated with the ratios. In three patients, the area ratio was smaller than 0.8 (0.67-0.75), meaning that the area decreased with at least 20% after surgery. In none of these patients a discoloration was observed. CONCLUSION: Discoloration of the spleen after Nissen fundoplication is not associated with post-operative splenic atrophy.1 maart 201

INFLUENCE OF INPUT PARAMETERS ON PREDICTION OF NOISE IN FACTORY WITH BARRIERS AND FITTINGS BY COMPUTER MODELLING

The validity of the computer-aided predictive model for the assessment of sound field in industrial halls with barriers, was examined. The range of possible error resulting from input parameters ucertainty was analyzed