Mapping the Complex Morphology of Cell Interactions with Nanowire Substrates Using FIB-SEM

Using high resolution focused ion beam scanning electron microscopy (FIB-SEM) we study the details of cell-nanostructure interactions using serial block face imaging. 3T3 Fibroblast cellular monolayers are cultured on flat glass as a control surface and on two types of nanostructured scaffold substrates made from silicon black (Nanograss) with low- and high nanowire density. After culturing for 72 hours the cells were fixed, heavy metal stained, embedded in resin, and processed with FIB-SEM block face imaging without removing the substrate. The sample preparation procedure, image acquisition and image post-processing were specifically optimised for cellular monolayers cultured on nanostructured substrates. Cells display a wide range of interactions with the nanostructures depending on the surface morphology, but also greatly varying from one cell to another on the same substrate, illustrating a wide phenotypic variability. Depending on the substrate and cell, we observe that cells could for instance: break the nanowires and engulf them, flatten the nanowires or simply reside on top of them. Given the complexity of interactions, we have categorised our observations and created an overview map. The results demonstrate that detailed nanoscale resolution images are required to begin understanding the wide variety of individual cells' interactions with a structured substrate. The map will provide a framework for light microscopy studies of such interactions indicating what modes of interactions must be considered

TiO2 Nanoparticles Are Phototoxic to Marine Phytoplankton

Nanoparticulate titanium dioxide (TiO2) is highly photoactive, and its function as a photocatalyst drives much of the application demand for TiO2. Because TiO2 generates reactive oxygen species (ROS) when exposed to ultraviolet radiation (UVR), nanoparticulate TiO2 has been used in antibacterial coatings and wastewater disinfection, and has been investigated as an anti-cancer agent. Oxidative stress mediated by photoactive TiO2 is the likely mechanism of its toxicity, and experiments demonstrating cytotoxicity of TiO2 have used exposure to strong artificial sources of ultraviolet radiation (UVR). In vivo tests of TiO2 toxicity with aquatic organisms have typically shown low toxicity, and results across studies have been variable. No work has demonstrated that photoactivity causes environmental toxicity of TiO2 under natural levels of UVR. Here we show that relatively low levels of ultraviolet light, consistent with those found in nature, can induce toxicity of TiO2 nanoparticles to marine phytoplankton, the most important primary producers on Earth. No effect of TiO2 on phytoplankton was found in treatments where UV light was blocked. Under low intensity UVR, ROS in seawater increased with increasing nano-TiO2 concentration. These increases may lead to increased overall oxidative stress in seawater contaminated by TiO2, and cause decreased resiliency of marine ecosystems. Phototoxicity must be considered when evaluating environmental impacts of nanomaterials, many of which are photoactive

Mapping alterations to the endogenous elemental distribution within the lateral ventricles and choroid plexus in brain disorders using X-ray fluorescence imaging

The choroid plexus and cerebral ventricles are critical structures for the production of cerebral spinal fluid (CSF) and play an important role in regulating ion and metal transport in the brain, however many aspects of its roles in normal physiology and disease states, such as psychiatric illness, remain unknown. The choroid plexus is difficult to examine in vivo, and in situ ex vivo, and as such has typically been examined indirectly with radiolabeled tracers or ex vivo stains, making measurements of the endogenous K+, Cl-, and Ca+ distributions unreliable. In the present study, we directly examined the distribution of endogenous ions and biologically relevant transition metals in the choroid plexus and regions surrounding the ventricles (ventricle wall, cortex, corpus callosum, striatum) using X-ray fluorescence imaging (XFI). We find that the choroid plexus was rich in Cl- and Fe while K+ levels increase further from the ventricle as Cl- levels decrease, consistent with the known role of ion transporters in the choroid plexus CSF production. A polyI:C offspring displayed enlarged ventricles, elevated Cl- surrounding the ventricles, and intraventricular calcifications. These observations fit with clinical findings in patients with schizophrenia and suggest maternal treatment with polyI:C may lead to dysfunctional ion regulation in offspring. This study demonstrates the power of XFI for examining the endogenous elemental distributions of the ventricular system in healthy brain tissue as well as disease models

THE IMPACT OF PROTECTION SYSTEMS ON PHYTOSANITARY CONDITION OF SOWINGS AND PRODUCTIVITY OF THE SPRING BARLEY VARIETY “YAROMIR” IN THE RYAZAN REGION

The current study gives the results of 2-year field trails which tested three protection systems for the spring barley variety “Yaromir” to improve the phytosanitary condition of sowings and to increase productivity. It has been established that the studied protection systems effectively protected spring barley from harmful organisms from sprouting to harvesting. With a total number of weeds of 80 pcs/m2 in 2017 the effectiveness of the herbicides was 91–94%; and with a total number of weeds of 72 pcs/m2 in 2018 the effectiveness of these preparations was 92–95%. There has been evaluated fungicides’ impact on the development of dark brown and net spots. The effectiveness of the preparations through study years ranged from 89 to 92% for dark brown spots and from 80 to 85% for net spots. As a result of the analysis of spring barley productivity, it has been revealed that under the effect of protection systems there has been obtained an additional grain yield of 1.42, 1.46, 1.44 t/ha in 2017 and 1.29, 1.33, 1.26 t/ha in 2018. The analysis of the economic efficiency of the studied protection systems has shown that in 2017 a conditionally net income ranged from 1,000 to 3,650 rubles/ha, in 2018 it ranged from 5,780 to 7,636 rubles/ha, when 1 ton of spring barley grain cost 5 thousand rubles in 2017, and 9 thousand rubles in 2018

Lipid-lowering effectiveness of a Russian generic of atorvastatin in patients with various hyperlipidaemia phenotypes

Aim. To assess lipid-lowering effectiveness of generic atorvastatin in patients with various hyperlipidaemia (HLP) phenotypes in an open, short-term (four weeks) study.Material and methods. All participants were divided into two groups — with isolated hypercholesterolemia (HCH) and normal fasting triglycerides, (n=25), and with combined HLP and TG levels >1,7 mmol/l (n=26). Atorvastain dose was 20 mg/d. Serum levels of total cholesterol (TCH), TG and high-density lipoprotein cholesterol (HDL- CH) were measured by standard enzyme methods. Medication effectiveness was assessed by the reduction in low- density lipoprotein CH (LDL-CH) and TG levels.Results. In both groups, the medication significantly decreased serum levels of LDL-CH by 34-36,4%, without any substantial inter-group difference. However, lipid-lowering effect in patients with lower baseline TG levels was stronger than in individuals with normal TG concentrations — 27,1% and 12,9%, respectively (p=0,027).Conclusion. Cholesterol-lowering effect of generic atorvastatin (20 mg/d) was similar in patients with IIa and IIb HL. The effect on TG levels depended on HLP phenotype and was greater in individuals with higher baseline TG levels

REDERIVATION BY EMBRYO TRANSFER IN STRAINS OF LABORATORY MICE AND RATS

Rederivation allows laboratory animal populations to be purged from specified pathogens and thus turns these animals to the SPF (specified pathogens free) status. Results of the rederivation of two unique rat strains selected at the Institute of Cytology and Genetics and one mouse strain are presented. The two rat strains are: tame Norway rats and rats with Inherited Stress Induced Arterial Hypertension (ISIAH strain). The ICR mouse strain has been named as abbreviation of the Institute of Cancer Research wherefrom these mice were distributed to laboratories all over the world. The SPF status of the rats after rederivation was confirmed by the method of indicator animals (sentinel animals). The optimized model of rederivation offered here involves a combination of such embryotechnological methods as freezing/cryopreservation of embryos, their washing through the number of fresh volumes of sterile media, growing in vitro for 48 hours, and subsequent transfer into either one or both uterine horns of recipient females. Application of this model to rederivation of ICR mice yielded 39 pups born in an SPF vivarium. It should be noticed that the effectiveness of the procedure met international standards, and characteristic features of phenotype were retained in all the three strains after rederivation