The Effect of Metformin on the Myocardial Tolerance to Ischemia-Reperfusion Injury in the Rat Model of Diabetes Mellitus Type II

In recent years, evidence has been accumulated that metformin, an antidiabetic drug in the biguanide class, in addition to its well-recognized glucose-lowering effect, can also reduce cardiovascular mortality in the patients with type 2 diabetes mellitus (T2DM). Besides, there are a few experimental studies on the possibility of the direct anti-ischemic effect of the drug in both type 1 diabetes mellitus and T2DM. In our study, myocardial tolerance to ischemia in rats with neonatal streptozotocin T2DM was investigated using the model of global ischemia-reperfusion of the isolated perfused heart. Metformin was administered i.p. at a dose of 200 mg/kg/day for 3 days prior to isolated heart perfusion. The results showed that both the infarct size and postischemic recovery of left ventricular function were not different between controls and metformin-treated animals. At the same time, the infarct size in the T2DM animals was significantly lower than that in the controls (24.4 ± 7.6% versus 45.0 ± 10.4%, resp., P < .01), indicative of the metabolic preconditioning in T2DM. It follows that the protocol of metformin administration used in this study had not elicited cardioprotective effect in animals with T2DM so that the different mechanism(s) may underlie the beneficial effect of metformin on cardiovascular complications in patients with T2DM which, however, would need further investigation

Multidifferential study of identified charged hadron distributions in ZZ-tagged jets in proton-proton collisions at s=\sqrt{s}=13 TeV

Jet fragmentation functions are measured for the first time in proton-proton collisions for charged pions, kaons, and protons within jets recoiling against a $Z$ boson. The charged-hadron distributions are studied longitudinally and transversely to the jet direction for jets with transverse momentum 20 $< p_{\textrm{T}} < 100$ GeV and in the pseudorapidity range $2.5 < \eta < 4$. The data sample was collected with the LHCb experiment at a center-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 1.64 fb$^{-1}$. Triple differential distributions as a function of the hadron longitudinal momentum fraction, hadron transverse momentum, and jet transverse momentum are also measured for the first time. This helps constrain transverse-momentum-dependent fragmentation functions. Differences in the shapes and magnitudes of the measured distributions for the different hadron species provide insights into the hadronization process for jets predominantly initiated by light quarks.Comment: All figures and tables, along with machine-readable versions and any supplementary material and additional information, are available at https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2022-013.html (LHCb public pages

Measurement of the B0s→μ+μ− Branching Fraction and Effective Lifetime and Search for B0→μ+μ− Decays

A search for the rare decays Bs0→μ+μ- and B0→μ+μ- is performed at the LHCb experiment using data collected in pp collisions corresponding to a total integrated luminosity of 4.4  fb-1. An excess of Bs0→μ+μ- decays is observed with a significance of 7.8 standard deviations, representing the first observation of this decay in a single experiment. The branching fraction is measured to be B(Bs0→μ+μ-)=(3.0±0.6-0.2+0.3)×10-9, where the first uncertainty is statistical and the second systematic. The first measurement of the Bs0→μ+μ- effective lifetime, τ(Bs0→μ+μ-)=2.04±0.44±0.05  ps, is reported. No significant excess of B0→μ+μ- decays is found, and a 95% confidence level upper limit, B(B0→μ+μ-)<3.4×10-10, is determined. All results are in agreement with the standard model expectations.A search for the rare decays $B^0_s\to\mu^+\mu^-$ and $B^0\to\mu^+\mu^-$ is performed at the LHCb experiment using data collected in $pp$ collisions corresponding to a total integrated luminosity of 4.4 fb$^{-1}$. An excess of $B^0_s\to\mu^+\mu^-$ decays is observed with a significance of 7.8 standard deviations, representing the first observation of this decay in a single experiment. The branching fraction is measured to be ${\cal B}(B^0_s\to\mu^+\mu^-)=\left(3.0\pm 0.6^{+0.3}_{-0.2}\right)\times 10^{-9}$, where the first uncertainty is statistical and the second systematic. The first measurement of the $B^0_s\to\mu^+\mu^-$ effective lifetime, $\tau(B^0_s\to\mu^+\mu^-)=2.04\pm 0.44\pm 0.05$ ps, is reported. No significant excess of $B^0\to\mu^+\mu^-$ decays is found and a 95 % confidence level upper limit, ${\cal B}(B^0\to\mu^+\mu^-)<3.4\times 10^{-10}$, is determined. All results are in agreement with the Standard Model expectations

ENVIRONMENTAL VOLUNTEERING IN RUSSIA

Young people are becoming more and more interested in environmental volunteering. The article is about the advantages of this activity and the opportunity to change the world for the better

Metformin in patients with ischemic heart disease and type 2 diabetes mellitus: mechanism of action and clinical efficiency

Diabetes mellitus is one of the leading causes of death in modern society, primarily due to its cardiovascular complications. This factor drives search for novel pharmacologic agents to affect not only glycemic levels, but also the cardiovascular prognosis in diabetic patients with ischemic heart disease. Recent studies demonstrate that aside from basic blood glucose lowering action, metformin shows beneficial influence on blood rheology and vascular tone, hemostasis, oxidative stress, lipid spectrum and delivers and an ant-ischemic effect. Here we review clinical and experimental evidence on cardio- and vasoprotective effects of metformin, highlighting their molecular mechanisms

The role of gut microbiota in metabolic regulation

Obesity and metabolic syndrome are among the major problems of modern society. The increase in obesity is associated with a corresponding increase in type 2 diabetes, cardiovascular disease and cancer. A huge amount of scientific research has been devoted to the development of methods to reduce obesity and its complications. In recent years, attention has shifted towards studying the intestinal microbiota not only as a possible component of the pathological process but also as a target of therapeutic intervention. Recent evidence, primarily from investigations in animal models, suggests that the intestinal microbiota affects nutrient acquisition and energy regulation. This review will discuss the role of the intestinal microbiota in metabolic processes as well as the latest developments on the improvement of disturbances specific to obesity and metabolic syndrome

Pairing between gypsy Insulators Facilitates the Enhancer Action in trans throughout the Drosophila Genome

The Suppressor of the Hairy wing [Su(Hw)] binding region within the gypsy retrotransposon is the best known chromatin insulator in Drosophila melanogaster. According to previous data, two copies of the gypsy insulator inserted between an enhancer and a promoter neutralize each other's actions, which is indicative of an interaction between the protein complexes bound to the insulators. We have investigated the role of pairing between the gypsy insulators located on homologous chromosomes in trans interaction between yellow enhancers and a promoter. It has been shown that trans activation of the yellow promoter strongly depends on the site of the transposon insertion, which is evidence for a role of surrounding chromatin in homologous pairing. The presence of the gypsy insulators in both homologous chromosomes even at a distance of 9 kb downstream from the promoter dramatically improves the trans activation of yellow. Moreover, the gypsy insulators have proved to stabilize trans activation between distantly located enhancers and a promoter. These data suggest that gypsy insulator pairing is involved in communication between loci in the Drosophila genome

Measurement of the Λb0→J/ψΛ\Lambda^0_b\rightarrow J/\psi\Lambda angular distribution and the Λb0\Lambda^0_b polarisation in pppp collisions

International audienceThis paper presents an analysis of the ${\Lambda}_b^0$→ J/ψΛ angular distribution and the transverse production polarisation of ${\Lambda}_b^0$ baryons in proton-proton collisions at centre-of-mass energies of 7, 8 and 13 TeV. The measurements are performed using data corresponding to an integrated luminosity of 4.9 fb$^{−1}$, collected with the LHCb experiment. The polarisation is determined in a fiducial region of ${\Lambda}_b^0$ transverse momentum and pseudorapidity of 1 < p$_{T}$< 20 GeV/c and 2 < η < 5, respectively. The data are consistent with ${\Lambda}_b^0$ baryons being produced unpolarised in this region. The parity-violating asymmetry parameter of the Λ → pπ$^{−}$ decay is also determined from the data and its value is found to be consistent with a recent measurement by the BES III collaboration.[graphic not available: see fulltext