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How to Set up a Minimally Invasive Program
Published in Theo Kofidis, Minimally Invasive Cardiac Surgery, 2021
In spite of all Darwinistic professional pressure, evolution of technology and encouragement or competition, there will be hopeless naysayers, whenever a new approach arises. Some 30 years ago, the same controversy was in full bloom in the field of abdominal surgery. Next on the line was thoracic surgery, which faced rigid sceptics and skepticism before galloping into the VATS arena. Can you imagine any abdominal or thoracic surgeon nowadays having any sense of reputation or putting bread on the table if he is oblivious to laparoscopy, or VATS, not to speak of uniport VATS? MICS will eventually go through a similar phase, with growing rates of adoption around the world, and similar scrutiny from conservative circles. With evolving technology, improving techniques on both ends of the cardiology-cardiac surgery spectrum and novel, hybrid procedures entering the market, it is only a matter of time for MICS to be established as the staple of heart treatments.
The Cell Membrane in the Steady State
Published in Nassir H. Sabah, Neuromuscular Fundamentals, 2020
A uniporter is a transmembrane protein that facilitates diffusion of a substance down a concentration gradient, without ATP hydrolysis, but at a rate that can be far higher than that of passive diffusion for that substance, the energy being derived from the concentration gradient of the transported substance. Glucose and amino acids are transported across the plasma membrane in this manner, the concentration gradient being established in these cases because these substances are used up in cell metabolism. The inner mitochondrial membrane has an efficient Ca2+ uniporter that allows a fast uptake of Ca2+ by mitochondria. This type of movement is referred to sometimes as facilitated transport, or facilitated diffusion. In a uniporter, a specific protein transports a particular substance by undergoing a conformational change, much like that illustrated in Figure 2.5 for the Na+-K+ pump but without ATP hydrolysis.
Di-Calciphor-Dependent Protection Against Cell Death Due to Mitochondrial Failure
Published in John J. Lemasters, Constance Oliver, Cell Biology of Trauma, 2020
Several years ago we obtained evidence for a control mechanism that functions to prevent irreversible damage to mitochondria during short-term anoxia7,8 (see Figure 1). This mechanism involves a co-ordinated inhibition of ion transport systems in the mitochondrial inner membrane;9 activation of this mechanism delays collapse of the electrochemical ion gradients across the inner membrane.8 The specific ion transport systems affected are those whose continued function would rapidly collapse the membrane potential. These include the ATP synthase, adenine nucleotide translocator, phosphate transporter, Ca2+ uniporter, and glu/asp transport system.10,11 Rapid and efficient inhibition of these systems slows the electrophoretic and pH-dependent movement of ions across the membrane, prevents osmotic swelling and preserves the ability of mitochondria to recover upon re-oxygenation.
Characterization of urinary protein profile in regular kratom (Mitragyna speciosa korth.) users in Malaysia
Published in Journal of Addictive Diseases, 2022
Rana Khudhair Jasim, Zurina Hassan, Darshan Singh, Edward Boyer, Lay-Harn Gam
Prior to LC/MS/MS analysis, the dried sample was reconstituted with 30 µl of 0.1% formic acid in HPLC grade water. LC/MS/MS analysis was performed according to the method described by Choi et al.28 with some modification using Finnigan LTQ LC/MS/MS Easy-nLC II (Thermo Scientific, USA) system. Easy column C18 (10 cm, 0.75 mm i.d., 3 µm; Thermo Scientific, San Jose, CA, USA) was conditioned at a flow rate of 0.3 µl/min for 4 µl, whereas Easy column C18 (2 cm 0.1 mm i.d., 5 µm; Thermo Scientific, San Jose, CA, USA) was used as the pre-column, it was conditioned at a flow rate of 3 µl/min for 15 µl. The running buffers A and B were 0.1% FA in deionized water and 0.1% FA in acetonitrile, respectively. 15 µl of samples were injected to the columns and separated at a flow rate of 0.3 µl/min with a gradient of 5% to 100% of solvent B in 30 minutes. The eluent was interphase into the mass spectrometer with a capillary temperature of 220 °C and 2.1 kV of source voltage. Peptides were detected by full scan mass analysis from m/z 300–2000 at a resolving power of 60000 with data-dependent LC/MS/MS analyses (ITMS). Single and unassigned charge states were rejected. The fragmentation technique used was collision-induced dissociation where the collision energy was set at 35. PEAKS studio Version 7 (Bioinformatics Solution, Waterloo, Canada) was used to perform database matching. Database downloaded from uniport was used for peptide matching. Carbamidomethylation and oxidation were set as fixed modifications. Maximum missed miscleavage was set as 2, while the maximum variable post translation medication was set at 3.
Anti-diabetogenic and in vivo antioxidant activity of ethanol extract of Dryopteris dilatata in alloxan-induced male Wistar rats
Published in Biomarkers, 2021
Akpotu E. Ajirioghene, Samuel I. Ghasi, Lawrence O. Ewhre, Olusegun G. Adebayo, Jerome N. Asiwe
Glucose uptake occurs in the cell through the glycoproteins family mainly known as glucose transporters (GLUTs) (Simmons 2017). The liver’s glucose transporter is regulated by GLUT-2 which fuels glucose metabolism and also provide metabolites that stimulate the transcription of glucose sensitive genes (Leturque et al. 2005, Chunudom et al.2020). Moreover, insulin is responsible for the regulation of glucose metabolism and inhibiting the insulin secretion resulted in elevated hepatic glucose release and decrease uptake of glucose in the muscle cells (Al-Goblan et al. 2014, Chunudom et al. 2020). Studies on type 1 diabetes have been done in laboratory animals models with the used of chemically active diabetogenic agents like alloxan. This agent selectively impairs pancreatic beta-cells and are transported through the plasma membrane of the beta-cells by the GLUT-2 glucose uniporter (Gorus et al. 1982, Elsner et al. 2002, Haddad et al. 2020). Alteration of the glucose uptake led to various diabetic disorders like hyperglycaemia, hyperlipidaemia, hypertension, nephropathy, neuropathy, polyuria, polyphagia, stroke, ketosis and many more (Malfa et al. 2020).
Blood-brain barrier receptors and transporters: an insight on their function and how to exploit them through nanotechnology
Published in Expert Opinion on Drug Delivery, 2019
Rui Pedro Moura, Cláudia Martins, Soraia Pinto, Flávia Sousa, Bruno Sarmento
GLUTs are expressed at both the luminal and abluminal membrane of BBB endothelial cells, in order to regulate brain glucose levels. However, there is a slight discrepancy in GLUT distribution ratio, with higher expression at the BBB luminal side, as a mechanism to generate a glucose transport gradient [76]. Furthermore, it has been described that this class of transporters present some differences in their conformation [77,78]. GLUTs can exist in two forms, including 1) bi-directional transporters that do not require the presence of sodium ions, thus acting as a passive, uniport pathway (GLUTs 1 to 14), and 2) unidirectional transporters that require the presence of sodium ions to achieve their function [79]. Since GLUTs are transporters and not receptors, the internalization process is a straightforward process involving 1) binding of the ligand to the transporter; 2) conformation changes in the transporter; and 3) release of the ligand towards the interior of the cell. Afterward, the transporter reverts to its original conformation. This, however, may not be the case for nanoparticles as due to their nanometric size, it seems likely that the particle will just attach to the transporter pore and be internalized after the transporter is recycled towards the inside of the cell [80].