119 research outputs found
Diabetes and colorectal cancer risk: A new look at molecular mechanisms and potential role of novel antidiabetic agents
Epidemiological data have demonstrated a significant association between the presence of type 2 diabetes mellitus (T2DM) and the development of colorectal cancer (CRC). Chronic hyperglycemia, insulin resistance, oxidative stress, and inflammation, the processes inherent to T2DM, also play active roles in the onset and progression of CRC. Recently, small dense low-density lipoprotein (LDL) particles, a typical characteristic of diabetic dyslipidemia, emerged as another possible underlying link between T2DM and CRC. Growing evidence suggests that antidiabetic medications may have beneficial effects in CRC prevention. According to findings from a limited number of preclinical and clinical studies, glucagon-like peptide-1 receptor agonists (GLP-1RAs) could be a promising strategy in reducing the incidence of CRC in patients with diabetes. However, available findings are inconclusive, and further studies are required. In this review, novel evidence on molecular mechanisms linking T2DM with CRC development, progression, and survival will be discussed. In addition, the potential role of GLP-1RAs therapies in CRC prevention will also be evaluated
Atherosclerosis development and progression: the role of atherogenic small, dense LDL.
Atherosclerosis is responsible for large cardiovascular mortality in many countries globally. It has been shown over the last decades that the reduction of atherosclerotic progression is a critical factor for preventing future cardiovascular events. Low-density lipoproteins (LDL) have been successfully targeted, and their reduction is one of the key preventing measures in patients with atherosclerotic disease. LDL particles are pivotal for the formation and progression of atherosclerotic plaques; yet, they are quite heterogeneous, and smaller, denser LDL species are the most atherogenic. These particles have greater arterial entry and retention, higher susceptibility to oxidation, as well as reduced affinity for the LDL receptor. Increased proportion of small, dense LDL particles is an integral part of the atherogenic lipoprotein phenotype, the most common form of dyslipidemia associated with insulin resistance. Recent data suggest that both genetic and epigenetic factors might induce expression of this specific lipid pattern. In addition, a typical finding of increased small, dense LDL particles was confirmed in different categories of patients with elevated cardiovascular risk. Small, dense LDL is an independent risk factor for cardiovascular diseases, which emphasizes the clinical importance of both the quality and the quantity of LDL. An effective management of atherosclerotic disease should take into account the presence of small, dense LDL in order to prevent cardiovascular complications
A New Look at Novel Cardiovascular Risk Biomarkers: The Role of Atherogenic Lipoproteins and Innovative Antidiabetic Therapies
The presence of residual cardiovascular disease (CVD) risk is a current dilemma in clinical practice; indeed, despite optimal management and treatment, a considerable proportion of patients still undergo major CV events. Novel lipoprotein biomarkers are suggested as possible targets for improving the outcomes of patients at higher risk for CVD, and their impact on major CV events and mortality have previously been investigated. Innovative antidiabetic therapies have recently shown a significant reduction in atherogenic lipoproteins, beyond their effects on glucose parameters; it has also been suggested that such anti-atherogenic effect may represent a valuable mechanistic explanation for the cardiovascular benefit of, at least, some of the novel antidiabetic agents, such as glucagon-like peptide-1 receptor agonists. This emphasizes the need for further research in the field in order to clearly assess the effects of innovative treatments on different novel biomarkers, including atherogenic lipoproteins, such as small dense low-density lipoprotein (LDL), lipoprotein(a) (Lp(a)) and dysfunctional high-density lipoprotein (HDL). The current article discusses the clinical importance of novel lipid biomarkers for better management of patients in order to overcome residual cardiovascular risk
Universality of pseudogap and emergent order in lightly doped Mott insulators
It is widely believed that high-temperature superconductivity in the cuprates
emerges from doped Mott insulators. The physics of the parent state seems
deceivingly simple: The hopping of the electrons from site to site is
prohibited because their on-site Coulomb repulsion U is larger than the kinetic
energy gain t. When doping these materials by inserting a small percentage of
extra carriers, the electrons become mobile but the strong correlations from
the Mott state are thought to survive; inhomogeneous electronic order, a
mysterious pseudogap and, eventually, superconductivity appear. How the
insertion of dopant atoms drives this evolution is not known, nor whether these
phenomena are mere distractions specific to hole-doped cuprates or represent
the genuine physics of doped Mott insulators. Here, we visualize the evolution
of the electronic states of (Sr1-xLax)2IrO4, which is an effective spin-1/2
Mott insulator like the cuprates, but is chemically radically different. Using
spectroscopic-imaging STM, we find that for doping concentration of x=5%, an
inhomogeneous, phase separated state emerges, with the nucleation of pseudogap
puddles around clusters of dopant atoms. Within these puddles, we observe the
same glassy electronic order that is so iconic for the underdoped cuprates.
Further, we illuminate the genesis of this state using the unique possibility
to localize dopant atoms on topographs in these samples. At low doping, we find
evidence for much deeper trapping of carriers compared to the cuprates. This
leads to fully gapped spectra with the chemical potential at mid-gap, which
abruptly collapse at a threshold of around 4%. Our results clarify the melting
of the Mott state, and establish phase separation and electronic order as
generic features of doped Mott insulators.Comment: This version contains the supplementary information and small updates
on figures and tex
Mapping the unconventional orbital texture in topological crystalline insulators
The newly discovered topological crystalline insulators (TCIs) harbor a
complex band structure involving multiple Dirac cones. These materials are
potentially highly tunable by external electric field, temperature or strain
and could find future applications in field-effect transistors, photodetectors,
and nano-mechanical systems. Theoretically, it has been predicted that
different Dirac cones, offset in energy and momentum-space, might harbor vastly
different orbital character, a unique property which if experimentally
realized, would present an ideal platform for accomplishing new spintronic
devices. However, the orbital texture of the Dirac cones, which is of immense
importance in determining a variety of materials properties, still remains
elusive in TCIs. Here, we unveil the orbital texture in a prototypical TCI
PbSnSe. By using Fourier-transform (FT) scanning tunneling
spectroscopy (STS) we measure the interference patterns produced by the
scattering of surface state electrons. We discover that the intensity and
energy dependences of FTs show distinct characteristics, which can directly be
attributed to orbital effects. Our experiments reveal the complex band topology
involving two Lifshitz transitions and establish the orbital nature of the
Dirac bands in this new class of topological materials, which could provide a
different pathway towards future quantum applications
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Genetic testing for Inherited Arrhythmia Syndromes and Cardiomyopathies: results of the European Heart Rhythm Association Survey.
Indications and clinical impact of genetic testing for cardiac diseases have increased significantly over the past years. The aim of this physician-based EHRA survey was to assess current clinical practice and access to genetic testing for cardiac diseases across ESC countries and to evaluate adherence to the 2022 EHRA/HRS/APHRS/LAHRS Expert Consensus Statement on genetic testing. An online questionnaire composed of 28 questions was submitted to the EHRA Research Network and European Reference Network GUARD-Heart healthcare partners and promoted via dedicated social media channels. There were 357 respondents from 69 countries, 40% working in a hospital setting with a cardiac genetic service and/or a dedicated clinic focusing on inherited cardiac diseases and 27% with an onsite genetic laboratory. No genetic testing or low annual rate (<10/y) was declared by 39% of respondents. The majority of respondents (78%) declared issues or limitations to genetic testing access in their clinical practice. The main reasons for not providing or limited access to genetic testing were no availability of dedicated unit or genetic laboratory (35%) or reimbursement issues (25%). The most frequently reported indication for genetic testing was diagnostic purpose (55%). Most respondents (92%) declared offering genetic testing preceded by genetic counselling and 42% regular multidisciplinary evaluations for patients with cardiac genetic diseases. The perceived value of genetic testing in the diagnostic, prognostic, and therapeutic assessment was variable (67%, 39%, and 29%, respectively) and primarily based on the specific inherited disease. The majority of respondents recommended cascade genetic testing for the first-degree family members in case of pathogenic/likely pathogenic (P/LP) variant in the proband. This survey highlights a significant heterogeneity of genetic testing access and provision and issues attributable to the availability of dedicated unit/genetic laboratory and reimbursement. However, adequate adherence to indications in the current recommendations for genetic testing in patients with cardiac diseases was observed
Quasiparticle interference and strong electron-mode coupling in the quasi-one-dimensional bands of Sr2RuO4
The single-layered ruthenate SrRuO has attracted a great deal of
interest as a spin-triplet superconductor with an order parameter that may
potentially break time reversal invariance and host half-quantized vortices
with Majorana zero modes. While the actual nature of the superconducting state
is still a matter of controversy, it has long been believed that it condenses
from a metallic state that is well described by a conventional Fermi liquid. In
this work we use a combination of Fourier transform scanning tunneling
spectroscopy (FT-STS) and momentum resolved electron energy loss spectroscopy
(M-EELS) to probe interaction effects in the normal state of SrRuO. Our
high-resolution FT-STS data show signatures of the \beta-band with a distinctly
quasi-one-dimensional (1D) character. The band dispersion reveals surprisingly
strong interaction effects that dramatically renormalize the Fermi velocity,
suggesting that the normal state of SrRuO is that of a 'correlated
metal' where correlations are strengthened by the quasi 1D nature of the bands.
In addition, kinks at energies of approximately 10meV, 38meV and 70meV are
observed. By comparing STM and M-EELS data we show that the two higher energy
features arise from coupling with collective modes. The strong correlation
effects and the kinks in the quasi 1D bands may provide important information
for understanding the superconducting state. This work opens up a unique
approach to revealing the superconducting order parameter in this compound
STM imaging of symmetry-breaking structural distortion in the Bi-based cuprate superconductors
A complicating factor in unraveling the theory of high-temperature (high-Tc)
superconductivity is the presence of a "pseudogap" in the density of states,
whose origin has been debated since its discovery [1]. Some believe the
pseudogap is a broken symmetry state distinct from superconductivity [2-4],
while others believe it arises from short-range correlations without symmetry
breaking [5,6]. A number of broken symmetries have been imaged and identified
with the pseudogap state [7,8], but it remains crucial to disentangle any
electronic symmetry breaking from pre-existing structural symmetry of the
crystal. We use scanning tunneling microscopy (STM) to observe an orthorhombic
structural distortion across the cuprate superconducting Bi2Sr2Can-1CunO2n+4+x
(BSCCO) family tree, which breaks two-dimensional inversion symmetry in the
surface BiO layer. Although this inversion symmetry breaking structure can
impact electronic measurements, we show from its insensitivity to temperature,
magnetic field, and doping, that it cannot be the long-sought pseudogap state.
To detect this picometer-scale variation in lattice structure, we have
implemented a new algorithm which will serve as a powerful tool in the search
for broken symmetry electronic states in cuprates, as well as in other
materials.Comment: 4 figure
Global variation in diabetes diagnosis and prevalence based on fasting glucose and hemoglobin A1c
Fasting plasma glucose (FPG) and hemoglobin A1c (HbA1c) are both used to diagnose diabetes, but these measurements can identify different people as having diabetes. We used data from 117 population-based studies and quantified, in different world regions, the prevalence of diagnosed diabetes, and whether those who were previously undiagnosed and detected as having diabetes in survey screening, had elevated FPG, HbA1c or both. We developed prediction equations for estimating the probability that a person without previously diagnosed diabetes, and at a specific level of FPG, had elevated HbA1c, and vice versa. The age-standardized proportion of diabetes that was previously undiagnosed and detected in survey screening ranged from 30% in the high-income western region to 66% in south Asia. Among those with screen-detected diabetes with either test, the age-standardized proportion who had elevated levels of both FPG and HbA1c was 29-39% across regions; the remainder had discordant elevation of FPG or HbA1c. In most low- and middle-income regions, isolated elevated HbA1c was more common than isolated elevated FPG. In these regions, the use of FPG alone may delay diabetes diagnosis and underestimate diabetes prevalence. Our prediction equations help allocate finite resources for measuring HbA1c to reduce the global shortfall in diabetes diagnosis and surveillance
Repositioning of the global epicentre of non-optimal cholesterol
High blood cholesterol is typically considered a feature of wealthy western countries(1,2). However, dietary and behavioural determinants of blood cholesterol are changing rapidly throughout the world(3) and countries are using lipid-lowering medications at varying rates. These changes can have distinct effects on the levels of high-density lipoprotein (HDL) cholesterol and non-HDL cholesterol, which have different effects on human health(4,5). However, the trends of HDL and non-HDL cholesterol levels over time have not been previously reported in a global analysis. Here we pooled 1,127 population-based studies that measured blood lipids in 102.6 million individuals aged 18 years and older to estimate trends from 1980 to 2018 in mean total, non-HDL and HDL cholesterol levels for 200 countries. Globally, there was little change in total or non-HDL cholesterol from 1980 to 2018. This was a net effect of increases in low- and middle-income countries, especially in east and southeast Asia, and decreases in high-income western countries, especially those in northwestern Europe, and in central and eastern Europe. As a result, countries with the highest level of non-HDL cholesterol-which is a marker of cardiovascular riskchanged from those in western Europe such as Belgium, Finland, Greenland, Iceland, Norway, Sweden, Switzerland and Malta in 1980 to those in Asia and the Pacific, such as Tokelau, Malaysia, The Philippines and Thailand. In 2017, high non-HDL cholesterol was responsible for an estimated 3.9 million (95% credible interval 3.7 million-4.2 million) worldwide deaths, half of which occurred in east, southeast and south Asia. The global repositioning of lipid-related risk, with non-optimal cholesterol shifting from a distinct feature of high-income countries in northwestern Europe, north America and Australasia to one that affects countries in east and southeast Asia and Oceania should motivate the use of population-based policies and personal interventions to improve nutrition and enhance access to treatment throughout the world.Peer reviewe
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