1,721,196 research outputs found
Thirty years of fruitful collaborations between a physician and mass spectrometrists in diabetes field
No full textThe nonenzymatic protein glycation and the subsequent formation of advanced glycation end products is a process involved in the long-term complications of diabetes. In this context the collaboration, in the last 30 years, between my research group, operating in the DPT of Medicine of Padua University, and the mass spectrometric group, operating in CNR of Padua, are described and discussed. The development of new mass spectrometric techniques has allowed investigation more indepth, starting from the applications on small molecules responsible for the browning observed in the interactions between sugars and proteins, and growing up to intact proteins as albumin, immunoglobulin, hemoglobin, and so forth, with the determination of their glycation levels as well as their glycation sites. This study has helped to clarify the role of advanced glycation end products in the pathogenesis of the chronic complications of diabetes. In particular the results obtained in diabetic nephropathy, diabetic cardiovascular disease and in placenta samples of patients affected by gestational diabetes are described in this review
Faster uphill relaxation in thermodynamically equidistant temperature quenches
Full text linkWe uncover an unforeseen asymmetry in relaxation: for a pair of thermodynamically equidistant temperature quenches, one from a lower and the other from a higher temperature, the relaxation at the ambient temperature is faster in the case of the former. We demonstrate this finding on hand of two exactly solvable many-body systems relevant in the context of single-molecule and tracer-particle dynamics. We prove that near stable minima and for all quadratic energy landscapes it is a general phenomenon that also exists in a class of non-Markovian observables probed in single-molecule and particle-tracking experiments. The asymmetry is a general feature of reversible overdamped diffusive systems with smooth single-well potentials and occurs in multiwell landscapes when quenches disturb predominantly intrawell equilibria. Our findings may be relevant for the optimization of stochastic heat engines
Single-file diffusion in a bi-stable potential: Signatures of memory in the barrier-crossing of a tagged-particle
Full text linkWe investigate memory effects in barrier-crossing in the overdamped setting. We focus on the scenario where the hidden degrees of freedom relax on exactly the same time scale as the observable. As a prototypical model, we analyze tagged-particle diffusion in a single file confined to a bi-stable potential. We identify the signatures of memory and explain their origin. The emerging memory is a result of the projection of collective many-body eigenmodes onto the motion of a tagged-particle. We are interested in the “confining” (all background particles in front of the tagged-particle) and “pushing” (all background particles behind the tagged-particle) scenarios for which we find non-trivial and qualitatively different relaxation behaviors. Notably and somewhat unexpectedly, at a fixed particle number, we find that the higher the barrier, the stronger the memory effects are. The fact that the external potential alters the memory is important more generally and should be taken into account in applications of generalized Langevin equations. Our results can readily be tested experimentally and may be relevant for understanding transport in biological ion-channels
The role of lipoprotein abnormalities as risk factors for macroangiopathy in type 2 diabetes
No full textMacroangiopathy in diabetes mainly consists of an accelerated form of atherosclerosis. Despite the high prevalence of risk factors, no more than 25% of the additional cardiovascular risk in diabetes can be explained by known risk factors. Lipoprotein abnormalities play a fundamental part in this context. In particular, high VLDL concentrations, smaller LDL particles, and reduced levels of the HDL2 subclass are hallmarks of type 2 diabetic patients with extrahepatic insulin resistance, hypertension, obesity and microalbuminuria, and they may help to explain why type 2 diabetic patients are prone to cardiovascular disease. Low Apolipoprotein AII levels in diabetic patients also seem to be relevant, since these patients frequently have reduced concentrations of HDL cholesterol, and these apo anomalies may predict fatal vascular events in such patients. As for small, dense LDL particles, which are more susceptible to oxidation and glycation, with a fundamental role in atherosclerosis, several studies have confirmed that the concentration of plasma triglyceride is the most important determinant of variability in LDL size. Oxidized LDL play a major part in the formation and development of atherosclerotic plaques. Oxidative modifications make LDL immunogenic and autoantibodies against oxidized LDL reportedly predict the progression of coronary artery disease. Judging from our data, humoral immune response could play a different role in different stages of the development of atherosclerosis. Patients with coronary heart disease, be they diabetic or not, very often have low levels of HDL cholesterol, but little information are available on the possible qualitative changes in their HDL. In a recent investigation, we demonstrated that 2D gel electrophoresis, followed by enzymatic digestion and MALDI MS, is an effective tool for characterizing Apolipoprotein AI changes, and modified-Apo AI levels are considerably higher in individuals with type 2 diabetes. In conclusion, there is evidence of a close connection between lipoprotein abnormalities and macroangiopathy in type 2 diabetes and this could help to explain the additional cardiovascular risk associated with diabetes. © 2010 Nova Science Publishers, Inc
Vaccination against COVID-19 infection: the need of evidence for diabetic and obese pregnant women
Full text linkAim: The recent availability of vaccines against COVID-19 has sparked national and international debate on the feasibility of administering them to pregnant and lactating women, given that these vaccines have not been tested to assess their safety and efficacy in such women. As concerns the risks of COVID-induced disease, published data show that pregnant women who develop COVID-19 have fewer symptoms than patients who are not pregnant, but they are more likely to need hospitalization in intensive care, and neonatal morbidity. Aim of the present perspective paper is to analyze the current literature regarding the use of the vaccine against COVID-19 infection, in terms of safety and protection, in high risk pregnant women as those affected by diabetes and obesity. Methods: Analysis of literature about vaccination against COVID-19 infection in pregnancy. Results: The main health organizations and international scientific societies, emphasize that—although data regarding the use of COVID vaccines during pregnancy and lactation are still lacking—vaccination should not be contraindicated. It should be considered for pregnant women at high risk of exposure to COVID-19. For such women, the potential benefits and risks should be assessed by the healthcare professionals caring for them. A recent prospective study to test the immunogenicity and reactogenicity of vaccination with COVID-19 mRNA in pregnant and lactating women, has showed that SARS-CoV-2 mRNA vaccination triggers a robust humoral immunity in pregnant and lactating women; there was also evidence of an immune transfer to their newborn. Conclusions: We urgently need data on the effect of COVID-19 vaccination, in terms of maternal and fetal outcomes and vaccine related symptoms in high risk women during pregnancy and breastfeeding. It is important to run campaigns to promote vaccination, in particular in pregnant women at high risk to have severe COVID infection as those diabetics and/or obese
Comment: Characteristics and outcomes of pregnant women with type 1 or type 2 diabetes—a 5-year national population-based cohort study
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