Enhancing the specific T cell immune response against micro- and nanoparticle immobilized antigen

The current study was a part of the project on generating viral particle traps occurring due to covalent immobilization on the interface of recombinant virus-specific polymer-based nano- and microparticles. It is assumed that protein-particle conjugates could be able to bind virions followed by engulfment by immune cells. The study was aimed to examine the effect of polylactic acid (PLA) and PLA block-copolymer with polyethylene glycol (PLA-PEG)-based micro- and nanoparticles on the cellular immune response against polymeric particle-bound antigen. Materials and methods. A recombinant chimeric protein beta-2-microglobulin — green fluorescent protein (β2M-sfGFP) was obtained by affine chromatography. The recombinant protein was immobilized onto the polymer particles, which were further used for mice immunization. Female F1 hybrid mice (CBA x C57BL) in experimental and control groups consisted of 4–6-month-old 15 animals (weighted 20–25 g). Intracellular cytokine staining was used to evaluate the cellular immune response. Results and discussion. It was shown that the nanoparticles of PLA block-copolymer with polyethylene glycol (PLA-PEG) were able to bind 10 microgram protein per 1 mg polymer. The polylactic acid nanoparticles were able to bind 2,3 microgram protein per 1 mg polymer. In experiment, mice in group 1 were immunized with 100 nm PLA-PEG particle-β2M-sfGFP conjugate, in group 2 — with same particles together with soluble β2M-sfGFP. In group 3, mice were immunized with 1400 nm PLA particles-β2M-sfGFP conjugate, and in group 4 — with same particles together with soluble protein. The spleens isolated 2 weeks after the four-time intraperitoneal immunization. Comparison of immune response between groups was assessed by nonparametric Kruskal–Wallis criterion with Tukey correction. It was shown that the number of antigen-specific CD4+ T cells produced to model protein was significantly higher after immunization with particle-β2M-sfGFP conjugate, as compared to control groups, wherein immunization was performed with a mixture of protein and unmodified particles (p < 0.001). It was found that the number of antigen-specific CD8+ T cells formed against β2m-sfGFP did not differ between all groups examined

Vascular age concept: role in assessing risk and choosing therapy

The article discusses the vascular age concept and modern approaches to assessing vascular age. It describes modern methods for measuring arterial stiffness (applanation tonometry or ultrasonic Doppler examination) as the most frequently used index of vascular age. The authors discuss the role of antihypertensive therapy and statins in preventing early vascular aging, and the relationship between the role of achieving lower blood pressure levels and the choice of certain antihypertensive agents to reduce arterial stiffness and ensure optimal vascular age. Increased arterial stiffness has been reported to be a marker of risk for developing severe complications of cardiovascular diseases, in particular, a meta-analysis showed that after taking into account the known risk factors for developing cardiovascular complications, higher carotid stiffness was associated with an increased risk of stroke. It is stated that in addition to biological age, vascular age may increase due to the cumulative effect of such risk factors as high blood pressure, impaired glucose homeostasis, obesity and hypercholesterolemia. Modern approaches to the preservation and maintenance of vascular age are discussed. The key role of achieving lower blood pressure levels is considered. It is emphasized that the role of combination drugs in preventing complications of cardiovascular diseases is strengthened, and approaches to choosing the optimal components of such combination drugs are also considered. The relationship between increased arterial stiffness and the development of cognitive disorders is discussed. The article describes the role of statins and effectiveness of the concomitant use of statins and combination antihypertensive therapy in reducing the pulse wave velocity

Queuing system with unreliable servers and inhomogeneous intensities for analyzing the impact of non-stationarity toperformance measures of wireless network under licensed shared access

Given the limited frequency band resources and increasing volume of data traffic in modern multiservice networks, finding new and more efficient radio resource management (RRM) mechanisms is becoming indispensable. One of the implemented technologies to solve this problem is the licensed shared access (LSA) technology. LSA allows the spectrum that has been licensed to an owner, who has absolute priority on its utilization, to be used by other participants (i.e., tenants). Owner priority impacts negatively on the quality of service (QoS) by reducing the data bit rate and interrupting user services. In this paper, we propose a wireless multiservice network scheme model described as a queuing system with unreliable servers and a finite buffer within the LSA framework. The aim of this work is to analyze main system performance measures: blocking probability, average number of requests in queue, and average queue length depending on LSA frequencies' availability. © 2020 by the authors

Upper bounds on the rate of convergence for constant retrial rate queueing model with two servers

The paper deals with a Markovian retrial queueing system with a constant retrial rate and two servers. We present the detailed description of the model as well as establish the sufficient conditions for null ergodicity and strong ergodicity of the corresponding process and obtain the upper bounds on the rate of convergence for both situations. © 2018 Springer-Verlag GmbH Germany, part of Springer Natur

On the bounds for a two-dimensional birth-death process with catastrophes

The model of a two-dimensional birth-death process with possible catastrophes is studied. The upper bounds on the rate of convergence in some weighted norms and the corresponding perturbation bounds are obtained. In addition, we consider the detailed description of two examples with 1-periodic intensities and various types of death (service) rates. The bounds on the rate of convergence and the behavior of the corresponding mathematical expectations are obtained for each example. © 2018 by the authors

Upper bounds on the rate of convergence for constant retrial rate queueing model with two servers

The paper deals with a Markovian retrial queueing system with a constant retrial rate and two servers. We present the detailed description of the model as well as establish the sufficient conditions for null ergodicity and strong ergodicity of the corresponding process and obtain the upper bounds on the rate of convergence for both situations. © 2018 Springer-Verlag GmbH Germany, part of Springer Natur

On the bounds for a two-dimensional birth-death process with catastrophes

The model of a two-dimensional birth-death process with possible catastrophes is studied. The upper bounds on the rate of convergence in some weighted norms and the corresponding perturbation bounds are obtained. In addition, we consider the detailed description of two examples with 1-periodic intensities and various types of death (service) rates. The bounds on the rate of convergence and the behavior of the corresponding mathematical expectations are obtained for each example. © 2018 by the authors