Search results for "element"
showing 10 items of 13601 documents
Electrospun bioactive mats enriched with Ca-polyphosphate/retinol nanospheres as potential wound dressing
2015
Background While electrospun materials have been frequently used in tissue engineering no wound dressings exist that significantly improved wound healing effectively. Methods We succeeded to fabricate three-dimensional (3D) electrospun poly(D,l-lactide) (PLA) fiber mats into which nanospheres, formed from amorphous calcium polyphosphate (polyP) nanoparticles (NP) and encapsulated retinol (“retinol/aCa-polyP-NS” nanospheres [NS]), had been incorporated. Results Experiments with MC3T3-E1 cells revealed that co-incubation of the cells with Ca-polyP together with retinol (or incubation with retinol/aCa-polyP-NS) resulted in a significant synergistic effect on cell growth compared with particle-…
Signal transduction in isolated fat body from the cockroach Blaptica dubia exposed to hypertrehalosaemic neuropeptide
1998
Hypertrehalosaemic hormones stimulate trehalogenesis while inhibiting glycolysis in cockroach fat body. Signal transduction of the hypertrehalosaemic peptide Bld HrTH was examined in isolated fat body of the Argentine cockroach Blaptica dubia with respect to its effects on the increase in trehalose production and decrease in the content of the glycolytic activator fructose 2,6-bisphosphate in the tissue. Cyclic AMP does not seem to be involved in these processes as the cAMP analogue cpt-cAMP and the phosphodiesterase inhibitor IBMX, which both permeate cell membranes, had no effect on either parameter. Octopamine at physiological concentrations (10−7 mol · l−1) was also ineffective, but at …
0329 Occupational exposure to metals and welding fumes, and risk of glioma in the interocc study
2017
Background Brain tumouraetiology is poorly understood. Based on their ability to pass through the blood-brain barrier, it has been hypothesised that exposure to metals may increase the risk of brain cancer. Results from the few epidemiological studies on this issue are inconsistent. Methods We investigated the relationship between glioma risk and occupational exposure to five metals - lead, cadmium, nickel, chromium and iron- as well as to welding fumes, using data from the seven-country INTEROCC study. A total of 1800 incident glioma cases and 5160 controls aged 30–69 years were included in the analysis. Lifetime occupational exposure to the agents was assessed using the INTEROCC JEM, a mo…
Zinc acexamate inhibits gastric acid and pepsinogen secretion in the rat.
1990
Abstract Pretreatment with zinc acexamate (25–100 mg kg−1 i.p.) inhibited acid and pepsinogen secretion in the pylorus-ligated rat. Zinc acexamate (5–50 mg kg−1 p.o.) also inhibited the increases in acid secretion induced by carbachol (10 μg kg−1) and 2-deoxy-D-glucose (200 mg kg−1) in the perfused stomach of the anaesthetized rat. A delayed antisecretory effect was observed with this drug on histamine induced responses. High concentrations of zinc acexamate (10−5-10−2 M) did not modify the in-vitro activity of pepsin. Administration of zinc acexamate resulted in an increase in the presence of pepsinogen at the mucosal level. A morphological examination of the gastric mucosa confirmed an ac…
Simulation of left ventricular outflow tract (LVOT) obstruction in transcatheter mitral valve-in-ring replacement.
2020
Left ventricular outflow tract (LVOT) obstruction is a feared complication of transcatheter mitral valve replacement (TMVR). This procedure leads to an elongation of LVOT in the left ventricle (namely, the neoLVOT), ultimately portending hemodynamic impairment and death. This study sought to understand the biomechanical implications of LVOT obstruction in two patients who underwent TMVR as an "off-label" application of the Edwards SAPIEN 3 (S3) Ultra transcatheter heart valve (THV). A computational framework of TMVR was developed to assess the neoLVOT area and quantify the sub-aortic flow structure. We observed that the annuloplasty ring serves as the key anchor zone of S3 Ultra THV. A good…
Pathophysiology of Cerebral Ischemia
1991
The weight of the brain amounts to only 2% of total body weight, but it receives 15% of the cardiac output and uses 20% of the oxygen consumed by the body. The energy supply is provided almost exclusively by glucose metabolism. The substrate for this is stored in the brain in the form of glucose or glycogen and is sufficient to cover the energy requirements for only about 1 min. Consequently, there is a delicate equilibrium between oxygen and nutrient supply from the blood and the energy requirements of the brain. Disturbances in neurologic function appear after a few seconds of ischemia, although they are not necessarily persistent at first.
Pathophysiological Aspects of Glucose Uptake by the Tumor Tissue under Various Conditions of Oxygen and Glucose Supply
1976
Earlier examinations of the glucose uptake in neoplastic tissue by isolated DS- Carcinosarcoma implanted into the rat kidney had the results as follows (VAUPEL, 1974): 1. An increase of the tumor mass from 3 to 13 g wet weight caused an exponential decrease of the glucose consumption by the tumor tissue from 44.4 to 6.7/umoles per 100 g/min; very young tumors of 3 – 4 g bad uptake rates from 27.8 to 44.4/umoles/100 g/min. 2. Simultaneous measurements of the mean actual glucose concentrations in the tumor tissue showed that in the very young tumors the concentration still ranged from 1.75 to 2.25/umoles/g wet weight, whereas those in old tumors drop as low as 0 to 0.17/umoles/g.
Chloride/sodium ratio and sodium.chloride difference inpatients with renal failure and metabolic acidosis in hemodialysis treatment
2018
Physicochemical stability of irinotecan injection concentrate and diluted infusion solutions in PVC bags
2000
Purpose. To determine the physicochemical stability of irinotecan injection concentrate and irinotecan infusion solutions after dilution in two commonly used infusion fluids (0.9% sodium chloride, 5% dextrose) in PVC bags, stored under refrigeration (2-8°C) or at room temperature either light protected or exposed to light. Methods. Stability of irinotecan injection concentrate was determined in the original amber glass vials. Diluted irinotecan infusion solutions were aseptically prepared by further dilution of irinotecan stock solution with either 0.9% sodium chloride or 5% dextrose in PVC bags, in amounts yielding irinotecan concentrations of 0.4, 1.0, or 2.8 mg/ml. Test solutions were s…