FEATURES OF BEHAVIORAL STUDY OF LABORATORY ANIMALS DURING EXAMINATION OF SPECIFIC ACTIVITY

2020 ◽  
pp. 5-13
Author(s):  
Kiseleva N.M. ◽  
Borozdenko D.A. ◽  
Shmigol T.A. ◽  
Negrebetsky V.V.
Keyword(s):  
Cognitive Functions ◽  
Specific Activity ◽  
Accurate Determination ◽  
Data Interpretation ◽  
Neurotropic Activity ◽  
Neurological Deficits ◽  
Laboratory Animals ◽  
Psychotropic Action ◽  
The Individual ◽  
Rats And Mice

The study of behavior and cognitive functions is rather difficult to interpret, is time-consuming and has a number of peculiarities both in planning the study and in conducting the tests themselves. For this kind of experiments, Various biomodels are used for such experiments, but this paper we will focus on experiments on the animals most often used in laboratory practice - small laboratory rodents (rats and mice). Most often, there is a need to carry out psychopharmacological studies in order to examine the specific activity of drugs belonging to the group of psychotropic drugs, however, medicine from other pharmacological groups can also have neurotropic activity and expressly influence the behavior and cognitive functions of both animals and humans. The paper highlights the main stages of planning and conducting a study of behavior and cognitive functions, starting with the analysis of power and calculating the sample size, the formation of experimental groups and ending with the features of data interpretation. It also presents the most commonly used psychopharmacological tests, as well as methods for confirming neurological deficits. Thus, it is possible to highlight a number of points enabling the most accurate determination the spectrum of psychotropic action of the studied drugs: The number of animals in groups should be sufficient for statistical analysis and usually ranges from 12 to 14 per group. When forming groups, it is necessary to type the behavior of animals using the Open Field test or its analogue and create groups of animals identical in behavior. When studying the spectrum of psychotropic action, one should not be limited to one or two narrowly targeted tests, but use a whole range of behavioral tests for the most complete picture of the drug's action. When assessing the effect of the drug in some cases, one should not average the results in a group, but use an assessment of the individual change in behavior of each animal.

Sex Differences in Cognition

2019 ◽  
pp. 41-66
Author(s):  
Elizabeth Hampson
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Sex Differences ◽  
Spatial Cognition ◽  
Sex Steroids ◽  
Cognitive Functions ◽  
Laboratory Animals ◽  
Human Central Nervous System ◽  
The Brain

Organizational and activational effects of sex steroids were first discovered in laboratory animals, but these concepts extend to hormonal actions in the human central nervous system. This chapter begins with a brief overview of how sex steroids act in the brain and how the organizational-activational hypothesis originated in the field of endocrinology. It then reviews common methods used to study these effects in humans. Interestingly, certain cognitive functions appear to be subject to modification by sex steroids, and these endocrine influences may help explain the sex differences often seen in these functions. The chapter considers spatial cognition as a representative example because the spatial family of functions has received the most study by researchers interested in the biological roots of sex differences in cognition. The chapter reviews evidence that supports an influence of both androgens and estrogens on spatial functions, and concludes with a glimpse of where the field is headed.

scholarly journals Investigating Molecular Mechanisms of Immunotoxicity and the Utility of ToxCast for Immunotoxicity Screening of Chemicals Added to Food

2021 ◽  
Vol 18 (7) ◽  
pp. 3332
Author(s):  
Olga V. Naidenko ◽  
David Q. Andrews ◽  
Alexis M. Temkin ◽  
Tasha Stoiber ◽  
Uloma Igara Uche ◽  
...  
Keyword(s):  
Immune System ◽  
High Throughput ◽  
Environmental Protection Agency ◽  
High Throughput Screening ◽  
Molecular Mechanisms ◽  
Specific Activity ◽  
Laboratory Animals ◽  
In Vitro Assays ◽  
Toxicological Studies

The development of high-throughput screening methodologies may decrease the need for laboratory animals for toxicity testing. Here, we investigate the potential of assessing immunotoxicity with high-throughput screening data from the U.S. Environmental Protection Agency ToxCast program. As case studies, we analyzed the most common chemicals added to food as well as per- and polyfluoroalkyl substances (PFAS) shown to migrate to food from packaging materials or processing equipment. The antioxidant preservative tert-butylhydroquinone (TBHQ) showed activity both in ToxCast assays and in classical immunological assays, suggesting that it may affect the immune response in people. From the PFAS group, we identified eight substances that can migrate from food contact materials and have ToxCast data. In epidemiological and toxicological studies, PFAS suppress the immune system and decrease the response to vaccination. However, most PFAS show weak or no activity in immune-related ToxCast assays. This lack of concordance between toxicological and high-throughput data for common PFAS indicates the current limitations of in vitro screening for analyzing immunotoxicity. High-throughput in vitro assays show promise for providing mechanistic data relevant for immune risk assessment. In contrast, the lack of immune-specific activity in the existing high-throughput assays cannot validate the safety of a chemical for the immune system.

scholarly journals Visualizing the Bohr effect in hemoglobin: neutron structure of equine cyanomethemoglobin in the R state and comparison with human deoxyhemoglobin in the T state

2016 ◽  
Vol 72 (7) ◽  
pp. 892-903 ◽  
Author(s):  
Steven Dajnowicz ◽  
Sean Seaver ◽  
B. Leif Hanson ◽  
S. Zoë Fisher ◽  
Paul Langan ◽  
...  
Keyword(s):  
Structural Changes ◽  
Accurate Determination ◽  
Bohr Effect ◽  
Salt Bridges ◽  
Histidine Residues ◽  
Regions Of Stability ◽  
The Individual ◽  
T State

Neutron crystallography provides direct visual evidence of the atomic positions of deuterium-exchanged H atoms, enabling the accurate determination of the protonation/deuteration state of hydrated biomolecules. Comparison of two neutron structures of hemoglobins, human deoxyhemoglobin (T state) and equine cyanomethemoglobin (R state), offers a direct observation of histidine residues that are likely to contribute to the Bohr effect. Previous studies have shown that the T-state N-terminal and C-terminal salt bridges appear to have a partial instead of a primary overall contribution. Four conserved histidine residues [αHis72(EF1), αHis103(G10), αHis89(FG1), αHis112(G19) and βHis97(FG4)] can become protonated/deuterated from the R to the T state, while two histidine residues [αHis20(B1) and βHis117(G19)] can lose a proton/deuteron. αHis103(G10), located in the α1:β1dimer interface, appears to be a Bohr group that undergoes structural changes: in the R state it is singly protonated/deuterated and hydrogen-bonded through a water network to βAsn108(G10) and in the T state it is doubly protonated/deuterated with the network uncoupled. The very long-term H/D exchange of the amide protons identifies regions that are accessible to exchange as well as regions that are impermeable to exchange. The liganded relaxed state (R state) has comparable levels of exchange (17.1% non-exchanged) compared with the deoxy tense state (T state; 11.8% non-exchanged). Interestingly, the regions of non-exchanged protons shift from the tetramer interfaces in the T-state interface (α1:β2and α2:β1) to the cores of the individual monomers and to the dimer interfaces (α1:β1and α2:β2) in the R state. The comparison of regions of stability in the two states allows a visualization of the conservation of fold energy necessary for ligand binding and release.

scholarly journals SYNTHESIS AND MIGRATION OF PROTEINS IN THE CELLS OF THE EXOCRINE PANCREAS AS REVEALED BY SPECIFIC ACTIVITY DETERMINATION FROM RADIOAUTOGRAPHS

1963 ◽  
Vol 16 (1) ◽  
pp. 1-23 ◽  
Author(s):  
H. Warshawsky ◽  
C. P. Leblond ◽  
B. Droz
Keyword(s):  
Specific Activity ◽  
Acinar Cells ◽  
Pancreatic Acinar Cells ◽  
Zymogen Granule ◽  
Zymogen Granules ◽  
The Mean ◽  
And Migration ◽  
Rats And Mice ◽  
Silver Grains ◽  
Golgi Zone

Radioautographs of pancreatic acinar cells were prepared in rats and mice sacrificed at various times after injection of leucine-, glycine-, or methionine-H3. Measurements of radioactivity concentration (number of silver grains per unit area) and relative protein concentration (by microspectrophotometry of Millon-treated sections) yielded the mean specific activity of proteins in various regions of the acinar cells. The 2 to 5 minute radioautographs as well as the specific activity time curves demonstrate protein synthesis in ergastoplasm. From there, most newly synthesized proteins migrate to and accumulate in the Golgi zone. Then they spread to the whole zymogen region and, finally, enter the excretory ducts. An attempt at estimating turnover times indicated that two classes of proteins are synthesized in the ergastoplasm: "sedentary" with a slow turnover (62.5 hours) and "exportable" with rapid turnover (4.7 minutes). It is estimated that the exportable proteins spend approximately 11.7 minutes in the Golgi zone where they are built up into zymogen granules, and thereafter 36.0 minutes as fully formed zymogen granules, before they are released outside the acinar cell as pancreatic secretion. The mean life span of a zymogen granule in the cell is estimated to be 47.7 minutes.

Features of the sensitivity of the central nervous system of the organism of experimental animals to the effects of certain psychotropic drugs and their combinations against the background of chronic alcohol intoxication in a chronopharmacological experiment

2020 ◽  
pp. 56-62
Author(s):  
E.V. Filippova
Keyword(s):  
Alcohol Intoxication ◽  
Laboratory Animals ◽  
Histological Structure ◽  
Chronic Alcohol ◽  
Behavioral Reactions ◽  
Experimental Animals ◽  
Chronic Alcohol Intoxication ◽  
Psychotropic Action ◽  
Adaptive Effect ◽  
The Central Nervous System

In a chronopharmacological experiment, the effect of two drugs with psychotropic action in combinations on the behavior of laboratory animals subjected to chronic alcohol intoxication was examined. Against the background of a deprimating agent, a decrease in the threshold of sensitivity to electrical irritation and the duration of an aggressive reaction was revealed; an increase in these indicators was established with a combination of a deprimating drug with an antioxidant. It has been shown that the antioxidant has a desynchronizing effect on the behavioral reactions of laboratory animals for two days, which indicates a pronounced adaptive effect. In the case of using combinations of a deprimating agent with an antioxidant, a decrease in the destruction of the histological structure of the myocardium against the background of chronic alcoholization was established.

scholarly journals Correlative Analysis of the Dimensional Properties of Bipyramidal Titania Nanoparticles by Complementing Electron Microscopy with Other Methods

Nanomaterials ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 3359
Author(s):  
Loïc Crouzier ◽  
Nicolas Feltin ◽  
Alexandra Delvallée ◽  
Francesco Pellegrino ◽  
Valter Maurino ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Size Distribution ◽  
Imaging Techniques ◽  
Accurate Determination ◽  
Measurement Procedure ◽  
Titania Nanoparticles ◽  
Ensemble Technique ◽  
Correlative Analysis ◽  
Liquid Suspension ◽  
The Individual

In this paper, the accurate determination of the size and size distribution of bipyramidal anatase nanoparticles (NPs) after deposition as single particles on a silicon substrate by correlative Scanning Electron Microscopy (SEM) with Atomic Force Microscopy (AFM) analysis is described as a new measurement procedure for metrological purposes. The knowledge of the exact orientation of the NPs is a crucial step in extracting the real 3D dimensions of the particles. Two approaches are proposed to determine the geometrical orientation of individual nano-bipyramides: (i) AFM profiling along the long bipyramid axis and (ii) stage tilting followed by SEM imaging. Furthermore, a recently developed method, Transmission Kikuchi Diffraction (TKD), which needs preparation of the crystalline NPs on electron-transparent substrates such as TEM grids, has been tested with respect to its capability of identifying the geometrical orientation of the individual NPs. With the NPs prepared homogeneously on a TEM grid, the transmission mode in a SEM, i.e., STEM-in-SEM (or T-SEM), can be also applied to extract accurate projection dimensions of the nanoparticles from the same sample area as that analysed by SEM, TKD and possibly AFM. Finally, Small Angle X-ray Scattering (SAXS) can be used as an ensemble technique able to measure the NPs in liquid suspension and, with ab-initio knowledge of the NP shape from the descriptive imaging techniques, to provide traceable NP size distribution and particle concentration.

COMPARATIVE EVALUATION OF NEW OSTEOPLASTIC MATERIALS BASED ON THE RESULTS OF ACUTE TOXICITY STUDIES

2021 ◽  
Vol Special issue (2) ◽  
pp. 29-33
Author(s):  
А.N. Akbarov ◽  
◽  
N.S. Ziyadullaeva
Keyword(s):  
Bioactive Glass ◽  
Intraperitoneal Injection ◽  
Comparative Evaluation ◽  
Laboratory Animals ◽  
Toxic Substances ◽  
Series Of Experiments ◽  
Osteoplastic Material ◽  
Rats And Mice ◽  
Lethal Doses

Three series of experiments were carried out and lethal doses of the new osteoplastic material 47.5 V were determined by the intraperitoneal and intragastric injection of the material to laboratory animals. A comparative evaluation with Bioactive glass BG-1D was also carried out. It was found that the LD50of 47,5B was 4274.51:4770.58 mg/kg for intragastric injection and 2358.31:2895.65 mg/kg for intraperitoneal injection to rats. In animals getting Bioactive glass BG-1D, these indicators changed slightly, amounting to 3439.04:3810.53 mg/kg and 1732.77:2730.93 mg/kg, respectively. Thus, according to the classification of substances according to the degree of toxicity, these materials can be attributed to practically non-toxic substances (according to the results of intraperitoneal injection of the material suspension to rats and mice) and low-toxic substances (according to the results of intragastric injection of the material suspension to rats)

scholarly journals Characteristics of the endometrium in menstruating species: lessons learned from the animal kingdom†

2020 ◽  
Vol 102 (6) ◽  
pp. 1160-1169
Author(s):  
Laura Catalini ◽  
Jens Fedder
Keyword(s):  
Menstrual Cycle ◽  
Animal Species ◽  
Lessons Learned ◽  
Primate Species ◽  
Fruit Bat ◽  
Laboratory Facilities ◽  
Elephant Shrew ◽  
The One ◽  
The Individual ◽  
Rats And Mice

Abstract Here we have summarized what is currently known about menstruating animal species with special emphasis on non-primate species: length of their menstrual cycle, ovulation, implantation, placentation, decidualization, and endometrial characteristics. Having an overview of all the possible animal models that can be used to study menstruation and the menstrual cycle could be useful to select the one that better matches the needs of the individual research projects. The most promising species to study menstruation seems to be the spiny mouse Acomys cahirinus. It is a rodent that could be easily held in the existing laboratory facilities for rats and mice but with the great advantage of having spontaneous menstruation and several human-like menstrual cycle characteristics. Among the species of menstruating bats, the black mastiff bat Molossus ater and wild fulvous fruit bat Rousettus leschenaultii are the ones presenting the most human-like characteristics. The elephant shrew seems to be the less suitable species among the ones analyzed. The induced mouse model of menstruation is also presented as an adaptable alternative to study menstruation.

Validation of Reverse-Engineered and Additive-Manufactured Microsurgical Instrument Prototype

2016 ◽  
Vol 23 (6) ◽  
pp. 606-612 ◽  
Author(s):  
Ramandeep Singh ◽  
Ashish Suri ◽  
Sneh Anand ◽  
Britty Baby
Keyword(s):  
Additive Manufacturing ◽  
Imaging Techniques ◽  
Laboratory Animals ◽  
Neurosurgical Procedures ◽  
Prototype Development ◽  
Computer Aided ◽  
Subtractive Manufacturing ◽  
Nerve Anastomosis ◽  
Scan Data ◽  
The Individual

With advancements in imaging techniques, neurosurgical procedures are becoming highly precise and minimally invasive, thus demanding development of new ergonomically aesthetic instruments. Conventionally, neurosurgical instruments are manufactured using subtractive manufacturing methods. Such a process is complex, time-consuming, and impractical for prototype development and validation of new designs. Therefore, an alternative design process has been used utilizing blue light scanning, computer-aided designing, and additive manufacturing direct metal laser sintering (DMLS) for microsurgical instrument prototype development. Deviations of DMLS-fabricated instrument were studied by superimposing scan data of fabricated instrument with the computer-aided designing model. Content and concurrent validity of the fabricated prototypes was done by a group of 15 neurosurgeons by performing sciatic nerve anastomosis in small laboratory animals. Comparative scoring was obtained for the control and study instrument. T test was applied to the individual parameters and P values for force ( P < .0001) and surface roughness ( P < .01) were found to be statistically significant. These 2 parameters were further analyzed using objective measures. Results depicts that additive manufacturing by DMLS provides an effective method for prototype development. However, direct application of these additive-manufactured instruments in the operating room requires further validation.

Dismantling of a Nuclear Fuel Fabric - Release of Building Rubble and Site: An Overview

2001 ◽  
Author(s):  
Elisabeth T. Aberl ◽  
Karl-Heinz Lehmann
Keyword(s):  
Nuclear Fuel ◽  
Specific Activity ◽  
Total Activity ◽  
Mean Value ◽  
Salt Mine ◽  
Individual Dose ◽  
Dose Limit ◽  
Uranium Fuel ◽  
Industrial Use ◽  
The Individual

Abstract Uranium fuel rods were produced in the nuclear fuel site. The buildings should be dismantled after decontamination and the site should be released for industrial use. The individual dose to the critical group is limited to an annual value of about 10 μSv. The determined specific activity for remediation of the site was a mean value of 60 mBq/g total activity. For the building rubble and soil primarily two pathways, disposal at a landfill and refill of a disused salt mine, were considered. As a result of the investigations the total activity for the disposal at a landfill had to be limited to about 6,6 GBq. For the refill of the salt mine the estimated individual dose fell below the dose limit in the range of 10 μSv/y.

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