Effect of Thyroid Hormones on the Development of Asymmetric Pigment Patterns in Teleost Fish: Experimental Data on the Example of Amatitlania nigrofasciata (Cichlidae) and Poecilia wingei (Poeciliidae)

2020 ◽  
Vol 47 (2) ◽  
pp. 198-204 ◽  
Author(s):  
D. V. Prazdnikov
Keyword(s):  
Experimental Data ◽  
Thyroid Hormones ◽  
Teleost Fish ◽  
Amatitlania Nigrofasciata ◽  
Pigment Patterns

scholarly journals Molecular cloning and characterization of thyroid hormone receptors in teleost fish

2001 ◽  
Vol 26 (1) ◽  
pp. 51-65 ◽  
Author(s):  
O Marchand ◽  
R Safi ◽  
H Escriva ◽  
E Van Rompaey ◽  
P Prunet ◽  
...  
Keyword(s):  
Thyroid Hormone ◽  
Thyroid Hormones ◽  
Teleost Fish ◽  
Hormone Receptor ◽  
Hormone Receptors ◽  
Thyroid Hormone Receptor ◽  
Nuclear Hormone Receptor ◽  
Hormone Response Elements ◽  
Reverse Transcription Pcr ◽  
Wide Range

Thyroid hormones are pleiotropic factors important for many developmental and physiological functions in vertebrates. Their effects are mediated by two specific receptors (TRalpha and TRbeta) which are members of the nuclear hormone receptor superfamily. To clarify the function of these receptors, our laboratory has started a comparative study of their role in teleost fish. This type of approach has been hampered by the isolation of specific clones for each fish species studied. In this report, we describe an efficient reverse transcription/PCR procedure that allows the isolation of large fragments corresponding to TRalpha and TRbeta of a wide range of teleost fish. Phylogenetic analysis of these receptors revealed a placement consistent with their origin, sequences from teleost fish being clearly monophyletic for both TRalpha and TRbeta. Interestingly, this approach allowed us to isolate (from tilapia and salmon) several new TRalpha or TRbeta isoforms resulting from alternative splicing. These isoforms correspond to expressed transcripts and thus may have an important physiological function. In addition, we isolated a cDNA encoding TRbeta in the Atlantic salmon (Salmo salar) encoding a functional thyroid hormone receptor which binds specific thyroid hormone response elements and regulates transcription in response to thyroid hormones.

scholarly journals Development of thyroid pathology in medical workers with chronic exposure to low doses of ionizing radiation

2021 ◽  
Vol 20 (5) ◽  
pp. 90-97
Author(s):  
L. D. Gordienko ◽  
T. P. Kiseleva ◽  
I. I. Gordienko ◽  
N. A. Tsap
Keyword(s):  
Experimental Data ◽  
Ionizing Radiation ◽  
Thyroid Hormones ◽  
Chronic Exposure ◽  
Low Dose ◽  
Thyroid Tissue ◽  
Medical Personnel ◽  
Low Doses ◽  
X Rays ◽  
Intercellular Contacts

Introduction. The literature review deals with the effects of ionizing radiation and radiation on the body of medical personnel.Materials and methods. 50 actual sources were analyzed. The relevance of the study of the constant, long-term influence of low doses of radiation is shown, in view of the increasing use of sources of ionizing radiation in various fields of scientific and practical human activity, including medicine.Results. Thanks to the analysis of numerous literature data, it was revealed that operating doctors, who are faced in their work with sources of ionizing radiation, often do not have a sufficient level of protection of the thyroid tissue from radiation. It was revealed that the overwhelming majority of studies highlighting thyroid pathology in medical personnel working with X-rays are aimed at identifying the risks of thyroid cancer and does not take into account the pathology of non-tumor genesis. Analyzed the data of scientific publications, allowing to draw a conclusion about the effects of chronic exposure to ionizing radiation, namely X-rays, in low doses on the thyroid tissue from a morphological and functional point of view.Discussion. It was established on the basis of the analysis of experimental data that under the influence of low-dose X-ray radiation, the intercellular contacts of thyrocytes are disconnected, which can lead to a decrease in the synthesis of thyroid hormones and, as a consequence, to the development of hypothyroidism.Conclusion. Based on the analysis of the experimental data, it has been established that under the influence of low-dose X-rays there is a disconnection of intercellular contacts of thyrocytes, which may lead to a decrease in the synthesis of thyroid hormones and, consequently, to the development of hypothyroidism.

scholarly journals Rapid method for the measurement of circulating thyroid hormones in low volumes of teleost fish plasma by LC-ESI/MS/MS

2013 ◽  
Vol 406 (3) ◽  
pp. 715-726 ◽  
Author(s):  
Pamela D. Noyes ◽  
Sean C. Lema ◽  
Simon C. Roberts ◽  
Ellen M. Cooper ◽  
Heather M. Stapleton
Keyword(s):  
Thyroid Hormones ◽  
Rapid Method ◽  
Teleost Fish ◽  
Esi Ms

Microdiffraction Patterns of Small Metallic Particles II; Theoretical Analysis

1982 ◽  
Vol 40 ◽  
pp. 668-669
Author(s):  
A. Gómez ◽  
P. Schabes-Retchkiman ◽  
M. José-Yacamán ◽  
T. Ocaña
Keyword(s):  
Experimental Data ◽  
Electron Diffraction ◽  
Theoretical Analysis ◽  
Size Range ◽  
Dynamical Theory ◽  
Metallic Particles ◽  
Splitting Effect

The splitting effect that is observed in microdiffraction pat-terns of small metallic particles in the size range 50-500 Å can be understood using the dynamical theory of electron diffraction for the case of a crystal containing a finite wedge. For the experimental data we refer to part I of this work in these proceedings.

Evidence for ordered Fe3Ni

1987 ◽  
Vol 45 ◽  
pp. 216-217
Author(s):  
K.B. Reuter ◽  
D.B. Williams ◽  
J.I. Goldstein
Keyword(s):  
Experimental Data ◽  
Martensitic Transformation ◽  
Electron Diffraction ◽  
Room Temperature ◽  
Direct Evidence ◽  
Transformation Product ◽  
Iron Meteorites ◽  
X Ray ◽  
Ni Content ◽  
Temperature Transformation

In the Fe-Ni system, although ordered FeNi and ordered Ni3Fe are experimentally well established, direct evidence for ordered Fe3Ni is unconvincing. Little experimental data for Fe3Ni exists because diffusion is sluggish at temperatures below 400°C and because alloys containing less than 29 wt% Ni undergo a martensitic transformation at room temperature. Fe-Ni phases in iron meteorites were examined in this study because iron meteorites have cooled at slow rates of about 10°C/106 years, allowing phase transformations below 400°C to occur. One low temperature transformation product, called clear taenite 2 (CT2), was of particular interest because it contains less than 30 wtZ Ni and is not martensitic. Because CT2 is only a few microns in size, the structure and Ni content were determined through electron diffraction and x-ray microanalysis. A Philips EM400T operated at 120 kV, equipped with a Tracor Northern 2000 multichannel analyzer, was used.

EELS white line intensities calculated for the 3d and 4d metals

1989 ◽  
Vol 47 ◽  
pp. 388-389
Author(s):  
C. C. Ahn ◽  
D. H. Pearson ◽  
P. Rez ◽  
B. Fultz
Keyword(s):  
Experimental Data ◽  
Line Intensity ◽  
Transition Probabilities ◽  
Initial Increase ◽  
White Line ◽  
Hartree Fock ◽  
Line Intensities ◽  
Integrated Intensity ◽  
X Ray Absorption ◽  
The Continuum

Previous experimental measurements of the total white line intensities from L2,3 energy loss spectra of 3d transition metals reported a linear dependence of the white line intensity on 3d occupancy. These results are inconsistent, however, with behavior inferred from relativistic one electron Dirac-Fock calculations, which show an initial increase followed by a decrease of total white line intensity across the 3d series. This inconsistency with experimental data is especially puzzling in light of work by Thole, et al., which successfully calculates x-ray absorption spectra of the lanthanide M4,5 white lines by employing a less rigorous Hartree-Fock calculation with relativistic corrections based on the work of Cowan. When restricted to transitions allowed by dipole selection rules, the calculated spectra of the lanthanide M4,5 white lines show a decreasing intensity as a function of Z that was consistent with the available experimental data.Here we report the results of Dirac-Fock calculations of the L2,3 white lines of the 3d and 4d elements, and compare the results to the experimental work of Pearson et al. In a previous study, similar calculations helped to account for the non-statistical behavior of L3/L2 ratios of the 3d metals. We assumed that all metals had a single 4s electron. Because these calculations provide absolute transition probabilities, to compare the calculated white line intensities to the experimental data, we normalized the calculated intensities to the intensity of the continuum above the L3 edges. The continuum intensity was obtained by Hartree-Slater calculations, and the normalization factor for the white line intensities was the integrated intensity in an energy window of fixed width and position above the L3 edge of each element.

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