Genetic environment of the blaKPC-2 gene in a Klebsiella pneumoniae isolate that may have been imported to Russia from Southeast Asia

The nucleotide sequence of a blaKPC-2-harboring plasmid (pKPCAPSS) from Klebsiella pneumoniae ST273 isolated in Saint Petersburg, Russia, from a patient with history of recent travel to Vietnam is presented. This 127,970-bp plasmid possessed both IncFII and IncR replicons. blaKPC-2 was localized on a hypothetical mobile element. This element was flanked by 38-bp inverted Tn3 repeats and included a Tn3-specific transposase gene, macrolide resistance operon (mphA-mrx-mphR), and a fragment of blaTEM with unique polymorphisms. © 2017 American Society for Microbiology. All Rights Reserved

Effect of recombinant Sox9 protein on the expression of cartilage-specific genes in human dermal fibroblasts cell culture

As a result of the experiments, it was shown that the recombinant Sox9 protein has practically no effect on chondrogenic differentiation and does not significantly change the expression of chondrogenesis gene

The Energy Density in the Casimir Effect

We compute the expectations of the squares of the electric and magnetic fields in the vacuum region outside a half-space filled with a uniform dispersive dielectric. We find a positive energy density of the electromagnetic field which diverges at the interface despite the inclusion of dispersion in the calculation. We also investigate the mean squared fields and the energy density in the vacuum region between two parallel half-spaces. Of particular interest is the sign of the energy density. We find that the energy density is described by two terms: a negative position independent (Casimir) term, and a positive position dependent term with a minimum value at the center of the vacuum region. We argue that in some cases, including physically realizable ones, the negative term can dominate in a given region between the two half-spaces, so the overall energy density can be negative in this region.Comment: 16 pages, 4 figures; 3 references and some new material in Sect. 4.4 adde

Amyloid beta is associated with carotid wall echolucency and atherosclerotic plaque composition

\ua9 The Author(s) 2024.Circulating amyloid-beta 1–40 (Αb40) has pro-atherogenic properties and could serve as a biomarker in atherosclerotic cardiovascular disease (ASCVD). However, the association of Ab40 levels with morphological characteristics reflecting atherosclerotic plaque echolucency and composition is not available. Carotid atherosclerosis was assessed in consecutively recruited individuals without ASCVD (n = 342) by ultrasonography. The primary endpoint was grey scale median (GSM) of intima-media complex (IMC) and plaques, analysed using dedicated software. Vascular markers were assessed at two time-points (median follow-up 35.5 months). In n = 56 patients undergoing carotid endarterectomy, histological plaque features were analysed. Plasma Αb40 levels were measured at baseline. Ab40 was associated with lower IMC GSM and plaque GSM and higher plaque area at baseline after multivariable adjustment. Increased Ab40 levels were also longitudinally associated with decreasing or persistently low IMC and plaque GSM after multivariable adjustment (p < 0.05). In the histological analysis, Ab40 levels were associated with lower incidence of calcified plaques and plaques without high-risk features. Ab40 levels are associated with ultrasonographic and histological markers of carotid wall composition both in the non-stenotic arterial wall and in severely stenotic plaques. These findings support experimental evidence linking Ab40 with plaque vulnerability, possibly mediating its established association with major adverse cardiovascular events

Local and Global Casimir Energies: Divergences, Renormalization, and the Coupling to Gravity

From the beginning of the subject, calculations of quantum vacuum energies or Casimir energies have been plagued with two types of divergences: The total energy, which may be thought of as some sort of regularization of the zero-point energy, $\sum\frac12\hbar\omega$, seems manifestly divergent. And local energy densities, obtained from the vacuum expectation value of the energy-momentum tensor, $\langle T_{00}\rangle$, typically diverge near boundaries. The energy of interaction between distinct rigid bodies of whatever type is finite, corresponding to observable forces and torques between the bodies, which can be unambiguously calculated. The self-energy of a body is less well-defined, and suffers divergences which may or may not be removable. Some examples where a unique total self-stress may be evaluated include the perfectly conducting spherical shell first considered by Boyer, a perfectly conducting cylindrical shell, and dilute dielectric balls and cylinders. In these cases the finite part is unique, yet there are divergent contributions which may be subsumed in some sort of renormalization of physical parameters. The divergences that occur in the local energy-momentum tensor near surfaces are distinct from the divergences in the total energy, which are often associated with energy located exactly on the surfaces. However, the local energy-momentum tensor couples to gravity, so what is the significance of infinite quantities here? For the classic situation of parallel plates there are indications that the divergences in the local energy density are consistent with divergences in Einstein's equations; correspondingly, it has been shown that divergences in the total Casimir energy serve to precisely renormalize the masses of the plates, in accordance with the equivalence principle.Comment: 53 pages, 1 figure, invited review paper to Lecture Notes in Physics volume in Casimir physics edited by Diego Dalvit, Peter Milonni, David Roberts, and Felipe da Ros

Expression of stromal cell-derived factor-1 on the surface of circulating platelets: from molecular interactions to clinical significance

The chemokine stromal cell-derived factor-1 (SDF-1) regulates leukocyte and progenitor cell trafficking from bone marrow to peripheral circulation and subsequently to tissue lesions. Platelets express substantial amounts of SDF-1 upon activation mediating the recruitment of progenitor cells on inflammatory endothelium and their differentiation into endothelial cells or macrophages. Absence of platelets results in decreased SDF-1 blood levels and into a defected tissue healing process, indicating that platelet-derived SDF-1 is crucially involved in progenitor cell-mediated tissue repair in vivo . Patients in need of vascular and/or myocardial repair, such as patients with reduced left ventricular function or patients with acute myocardial infarction, present with increased expression levels of platelet-derived SDF-1. Recently, a novel receptor for SDF-1 has been described, the so called CXCR7. Further studies are needed to elucidate the pathways of platelet-derived SDF-1 function in vascular homeostasis. The aim of the present review is to summarize the recently described role of platelet-derived SDF-1 in interaction with blood cells and especially progenitor cells and its potential clinical significance in patients with ischemic heart disease

Increased myeloperoxidase plasma levels in patients with alzheimer's disease

Background: Increasing evidence supports the role of cardiovascular risk factors in the development of Alzheimer's disease (AD). Objective: In the present pilot study, we investigated plasma concentrations of myeloperoxidase (MPO) and its possible association with plasma amyloid-β (Aβ) 1-42/1-40 ratio in AD patients and elderly healthy controls. Methods: The study sample included 28 AD patients and 27 elderly individuals with a normal cognitive status as a control group. The Mini-Mental Status Examination was used to determine the global cognition. MPO, Aβ1-40, and Aβ1-42 plasma concentrations were measured by enzyme linked immunoabsorbent assays. Results: AD patients showed significantly higher plasma concentrations of MPO in comparison to healthy elderly controls (AD versus healthy elderly controls (mean ± SD): 132.8 ± 114.8 ng/mL versus 55.0 ± 42.6 ng/mL; p = 0.002). MPO plasma concentrations showed a significant positive correlation in the whole sample with the presence of AD (ρ = 0.428, p < 0.001) and its stage (ρ = 0.331; p = 0.013) as well as with plasma concentrations of Aβ1-42 (ρ = 0.406; p = 0.004) and Aβ1-42/1-40 ratio (ρ = 0.354; p = 0.013). In a binary logistic regression model, plasma MPO concentrations were independently associated with the presence of AD (p = 0.014). Conclusion: AD patients showed significantly increased plasma levels of MPO, which could be an important molecular link between atherosclerosis and AD. Further studies should evaluate whether MPO may also be a useful biomarker and potential new treatment target in AD. © 2014-IOS Press and the authors. All rights reserved