Measurement of the Pion Form Factor with CMD-3 Detector and Its Implication to the Hadronic Contribution to Muon (g-2).

The cross section of the process e^{+}e^{-}→π^{+}π^{-} has been measured in the center-of-mass energy range from 0.32 to 1.2 GeV with the CMD-3 detector at the electron-positron collider VEPP-2000. The measurement is based on an integrated luminosity of about 88 pb^{-1}, of which 62 pb^{-1} represent a complete dataset collected by CMD-3 at center-of-mass energies below 1 GeV. In the dominant region near the ρ resonance a systematic uncertainty of 0.7% was achieved. The implications of the presented results for the evaluation of the hadronic contribution to the anomalous magnetic moment of the muon are discussed.

Erythrocytes membrane fluidity changes induced by adenylyl cyclase cascade activation: study using fluorescence recovery after photobleaching.

In this study, fluorescence recovery after photobleaching (FRAP) experiments were performed on RBC labeled by lipophilic fluorescent dye CM-DiI to evaluate the role of adenylyl cyclase cascade activation in changes of lateral diffusion of erythrocytes membrane lipids. Stimulation of adrenergic receptors with epinephrine (adrenaline) or metaproterenol led to the significant acceleration of the FRAP recovery, thus indicating an elevated membrane fluidity. The effect of the stimulation of protein kinase A with membrane-permeable analog of cAMP followed the same trend but was less significant. The observed effects are assumed to be driven by increased mobility of phospholipids resulting from the weakened interaction between the intermembrane proteins and RBC cytoskeleton due to activation of adenylyl cyclase signaling cascade.

Adsorption of semiflexible wormlike polymers to a bar and their double-chain complex formation.

We theoretically study pairing (double-strand complexation) of semiflexible wormlike chains (WLC) due to their side-to-side attraction. Considering binding of two WLCs of high stiffness we start with the case of infinite stiffness of one chain which is replaced with a straight bar. A combination of the quantitative transfer matrix approach with scaling arguments in terms of trains, loops of different sizes, tails and supertrains allowed us to characterize all the regimes of semiflexible chain adsorption on a bar. In particular, we predict a self-similar monomer concentration profile c(r) ∝ r-10/3 near the bar (at distances r below the chain Kuhn length l) at the critical point for adsorption. Such localized critical profile leads to a sharp adsorption transition. Furthermore, we found that supertrains serve as the basic structural elements in WLC complexes leading to bridging, network formation and condensation of semiflexible polymers in dilute solutions. Polymer collapse (precipitation) and redissolution on increasing attraction strength are predicted in qualitative agreement with experiments on aqueous solutions of DNA and F-actin.

Effects of a Hydrolyzed Lignin Derivative on Bleomycin-Induced Pulmonary Fibrosis in Mice.

Female C57BL/J mice with pulmonary fibrosis induced by injections of bleomycin (20 mg/kg intraperitoneally, 8 times for 4 weeks) were treated with a lignin derivative-based composition BP-C3 (80 mg/kg, daily intragastric administrations for 4 weeks). Bleomycin treatment increased the severity of pulmonary fibrosis (Ashcroft score increased from 1.43±0.20 to 4.17±0.48) and the percentage of α-SMA+ tissue (from 15.22±1.01 to 33.12±2.30%) and DNA-synthetizing nuclei (from 1.05±0.14 to 3.38±0.375). After treatment with BP-C3, we observed a tendency to a decrease in Ashcroft score (to 3.40±0.51) and a significant decrease in the percentage of α-SMA+ tissue to 24.30±1.70%; the percentage of DNA-synthetizing nuclei decreased to a lesser extent (to 3.03±0.22%). These results suggest that BP-C3 has a moderate antifibrotic activity.

Model of Accelerated Aging in CB6F2 Mice Induced by Ionizing Radiation.

A model for accelerated aging in mice was developed: CB6F2 mice aged 39-45 days were exposed to fractionated 4-fold relatively uniform γ-radiation (137Cs, 0.98 Gy/min) at a total dose of 6.8 Gy. Radiation exposure led to delayed active growth, leukopenia, and lymphopenia for over 1 year during the post-radiation period. The death of irradiated males and females occurred significantly earlier than in control group animals. Median lifespans in the experimental group were 35-38% lower than in the control group (p<0.001). Ionizing radiation exposure led to the early development of hair depigmentation, cachexia, and the development of aging-associated diseases. In irradiated mice, oncological pathology constituted 30-35% in the mortality structure, which is twice as often as in the control group. The developed model can be used to study the pathogenesis of accelerated aging under radiation exposure and the search for means of its prevention and treatment.

Effect of Polyphenolic Composition BP-C2 on Lung Carcinogenesis Induced by Urethane in Progeny of Irradiated Male BALB/c Mice.

We studied the effects of polyphenolic composition BP-C2, comprising molybdenum with lignin derivatives, on lung carcinogenesis induced by urethane in the progeny of F0 male BALB/c mice preconceptionally exposed to radiation in a dose of 1 Gy. The multiplicity of lung tumors in the progeny of irradiated mice was higher than in the progeny of non-irradiated male parents by 50% in females and 43% in males (p<0.05). In F1 mice (progeny of irradiated F0 male parents treated with BP-C2), the multiplicity of lung tumors was also higher, but this increase was less pronounced: 35% in females (p=0.3852) and 23% in males (p=0.0766). We have demonstrated that administration of BP-C2 to irradiated parents (F0) efficiently inhibits carcinogenesis in their F1 progeny. The use of BP-C2 in irradiated male parents and their progeny not only reduced the multiplicity of tumors, but also normalized body weights in the F1 progeny. Our study demonstrates potential of the polyphenolic composition BP-C2 for chemoprophylaxis of radiation-induced transgenerational carcinogenesis.

[Metastatic risk factors in pheochromocytoma/paraganglioma].

Currently, all pheochromocytoma/paraganglioma (PPGLs) are considered malignant due to metastatic potential. Consequently, PPGLs are divided into «metastatic¼ and «non-metastatic¼. Metastatic PPGLs can be with synchronous metastasis (metastases appear simultaneously with the identified primary tumor) or metachronous (metastases develop after removal of the primary tumor). The term metastatic PPGLs is not used in the presence of tumor invasion into surrounding organs and tissues, without the presence of distant metastases of lymphogenic or hematogenic origin. It is generally believed that about 10% of pheochromocytomas and about 40% of sympathetic paragangliomas have metastatic potential. On average, the prevalence of PPGLs with the presence of metastases is 15-20%. Risk factors for metastatic PPGLs are widely discussed in the literature, the most significant of which are groups of clinical, morphological and genetic characteristics. The review presents a discussion of such risk factors for metastatic PPGLs as age, localization and type of hormonal secretion of the tumor, the size and growth pattern of the adrenal lesion, the presence of necrosis and invasion into the vessels, the tumor capsule surrounding adipose tissue, high cellular and mitotic activity, Ki-67 index, expression of chromogranin B and S100 protein, the presence of genetic mutations of three main clusters (pseudohypoxia, kinase signaling and Wnt signaling).Over the past two decades, a number of authors have proposed various predictor factors and scales for assessing a probability of metastatic PPGLs. The review contains detailed description and comparison of sensitivity and specificity of such predictor scales as PASS, GAPP, M-GAPP, ASES and COPPS.

Biosynthesis of the prion proteins in scrapie-infected cells in culture

Prions are small proteinaceous particles that transmit scrapie and other fatal encephalopathies of humans and animals, and that appear to be devoided of nucleic acids. The only known-and perhaps the sole-component of the scrapie prion is an abnormal host-encoded protein, the scrapie prion protein PrPSc. The biosynthesis of this pathological protein in the host cell, which is thus of paramount importance to prion replication, is still poorly understood. We are studying the biosynthesis and degradation of the scrapie prion protein PrPSc and of its normal isoform PrPC in scrapie-infected rodent cells in culture. PrPC is anchored to the plasma membrane through a glycosylphosphatidylinositol (GPI) moiety. In scrapie-infected mouse neuroblastoma N2a cells, PrPSc is formed post-translationally, probably from plasma membrane PrPC, in an unknown subcellular compartment that is readily accessible from the plasma membrane. Transport along the secretory pathway is necessary for PrPSc synthesis. In contrast to PrPC, PrPSc accumulates intracellularly, primarily in secondary lysosomes. The subcellular compartment(s) in which PrPSc is formed remain to be determined