scholarly journals A Comparative Study on the Structural Features of Muscle Fibers in Intrinsic Lingual Muscles of 21 Day Old and 9 Month Old Mice Using Light and Electron Microscopy

2006 ◽  
Vol 30 (1) ◽  
pp. 47-51
Author(s):  
Aysel Temelli ◽  
Fatime Geyikoğlu
Keyword(s):  
Electron Microscopy ◽  
Comparative Study ◽  
Muscle Fibers ◽  
Light And Electron Microscopy ◽  
Structural Features ◽  
Old Mice

Correlated 3D Light and Electron Microscopy of Large, Complex Structures: Analysis of Transverse Tubules in Heart Failure

1998 ◽  
Vol 4 (S2) ◽  
pp. 440-441
Author(s):  
Maryann E. Martone ◽  
Andrea Thor ◽  
Stephen J. Young ◽  
Mark H. Ellisman.
Keyword(s):  
Electron Microscopy ◽  
Electron Tomography ◽  
Light And Electron Microscopy ◽  
Structural Features ◽  
Electron Microscopic Level ◽  
Specimen Preparation ◽  
Large Sample Size ◽  
Electron Microscopic ◽  
High Voltage Electron Microscopy ◽  
Voltage Electron

Light microscopic imaging has experienced a renaissance in the past decade or so, as new techniques for high resolution 3D light microscopy have become readily available. Light microscopic (LM) analysis of cellular details is desirable in many cases because of the flexibility of staining protocols, the ease of specimen preparation and the relatively large sample size that can be obtained compared to electron microscopic (EM) analysis. Despite these advantages, many light microscopic investigations require additional analysis at the electron microscopic level to resolve fine structural features.High voltage electron microscopy allows the use of relatively thick sections compared to conventional EM and provides the basis for excellent new methods to bridge the gap between microanatomical details revealed by LM and EM methods. When combined with electron tomography, investigators can derive accurate 3D data from these thicker specimens. Through the use of correlated light and electron microscopy, 3D reconstructions of large cellular or subcellular structures can be obtained with the confocal microscope,

scholarly journals Altered Hypoxia-Induced and Heat Shock Protein Immunostaining in Secondary Hair Follicles Associated with Changes in Altitude and Temperature in Tibetan Cashmere Goats

Animals ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 2798
Author(s):  
Yanyu He ◽  
Xiu Liu ◽  
Jie De ◽  
Saihong Kang ◽  
John S. Munday
Keyword(s):  
Electron Microscopy ◽  
Light And Electron Microscopy ◽  
Structural Features ◽  
Hair Shaft ◽  
Hair Follicles ◽  
Gansu Province ◽  
Outer Root Sheath ◽  
Average Temperature ◽  
Root Sheath ◽  
Cashmere Goats

This experiment compared secondary hair follicles (SFs) in Tibetan cashmere goats from two different steppes that were at different altitudes and had different temperatures. Twenty-four 2-year-old goats were studied. Twelve goats were from Rikaze in Tibet which is at an altitude of above 5000 m with an average temperature of 0 °C. The other 12 studied goats were from Huan County of Gansu Province which is around 2000 m above sea level with an average temperature of 9.2 °C. The structural features of SFs were assessed using light microscopy and transmission electron microscopy. The presence of HIF-1a, HIF-2a, HIF-3a, HSP27, and HOXC13 proteins was studied using immunohistochemistry and immunofluorescence. Light and electron microscopy revealed that the SFs of the Tibetan cashmere goats that lived in the Rikaze Steppe were in the proanagen stage in May. However, the SFs of the goats from the lower warmer Huan County were in the anagen stage at the same time. Immunohistochemistry revealed intense immunostaining for HIF-1a protein in the inner root sheath (IRS) and hair shaft (HS); immunostaining against HIF-2a in the outer root sheath (ORS) and IRS; HIF-3a protein immunostaining in the ORS; HSP27 immunostaining in the ORS, IRS, and HS; and HOXC13 immunostaining in the ORS and HS. HIF-1a protein expression in the IRS and HS was higher than the expression in the ORS (p < 0.05) while the expression of HIF-2a protein was higher in the ORS and IRS than the HS (p < 0.05). The expression of HIF-3a protein was higher in the ORS than in the IRS (p < 0.05). Expression of HOXC13 protein was higher in the ORS than in the IRS and HS (p < 0.05). Immunostaining of HIF-1a, HIF-2a, and HSP27 protein was significantly higher in SFs from cashmere goats from Rikaze than in goats from Huan (p < 0.05). In contrast, HOX13 protein immunostaining was significantly higher in cashmere goats from Huan than from Rikaze (p < 0.05). Significant differences were observed in the SFs of cashmere goats from two locations that differ in altitude and temperature. This suggests the differences in the secondary hair follicles could be due to the hypoxia and lower temperatures experienced by the goats in Rikaze. These results are useful in understanding how altitude and temperature influence SF development. Hair produced by the SFs are used for down fiber. Therefore, understanding of the factors that influence SF development will allow the production and harvest of these valuable fibers to be maximized.

Techniques Involved in the Acquisition of Serial Sections of the Atrioventricular Node for Light and Electron Microscopy

1968 ◽  
Vol 26 ◽  
pp. 226-227
Author(s):  
Sheila S. Emmett ◽  
J. C. Thaemert
Keyword(s):  
Electron Microscopy ◽  
Osmium Tetroxide ◽  
Light And Electron Microscopy ◽  
Atrioventricular Node ◽  
Electron Microscopic Level ◽  
Serial Sections ◽  
Electron Microscopic ◽  
Trapezoidal Shape ◽  
Old Mice

The acquisition of serial sections of the atrioventricular node for light and electron microscopy is a formidable task. Ordinary techniques are not adequate if the best possible results are to be achieved at the electron microscopic level. The techniques outlined below have proven to be valuable in locating and determining the position of the AV node.Whole hearts of 2-week old mice were fixed, in situ, by perfusion with 1% phosphate-buffered osmium tetroxide. The hearts were removed from the animals, sectioned transversely into 3 slices approximately equal in thickness, dehydrated in graded concentrations of ethanol and embedded in Epon 812. The block faces were trimmed to a trapezoidal shape ranging in size from 0.75 x 1 mm to 4 x 5 mm. Serial sections approximately 2 microns in thickness were cut with glass knives on a Porter-Blum MT-2 Ultramicrotome. While floating on a drop of water on the knife, each section was stretched with 1 drop of a 1:1, xylene in chloroform mixture applied directly to the section. The sections were picked up individually with a brush, transferred to a glass slide and oven dried for several hours prior to staining.

scholarly journals A STRAND OF CARDIAC MUSCLE

1967 ◽  
Vol 33 (1) ◽  
pp. 103-129 ◽  
Author(s):  
Edward A. Johnson ◽  
Joachim R. Sommer
Keyword(s):  
Electron Microscopy ◽  
Cardiac Muscle ◽  
Papillary Muscle ◽  
Muscle Fibers ◽  
Light And Electron Microscopy ◽  
Rabbit Heart ◽  
Transverse Tubular System ◽  
Fiber Contact ◽  
Tubular System ◽  
Comprehensive Study

The structure of a small strand of rabbit heart muscle fibers (trabecula carnea), 30–80 µ in diameter, has been examined with light and electron microscopy. By establishing a correlation between the appearance of regions of close fiber contact in light and electron microscopy, the extent and distribution of regions of close apposition of fibers has been evaluated in approximately 200 µ length of a strand. The distribution of possible regions of resistive coupling between fibers has been approximated by a model system of cables. The theoretical linear electrical properties of such a system have been analyzed and the implications of the results of this analysis are discussed. Since this preparation is to be used for correlated studies of the electrical, mechanical, and cytochemical properties of cardiac muscle, a comprehensive study of the morphology of this preparation has been made. The muscle fibers in it are distinguished from those of the rabbit papillary muscle, in that they have no triads and have a kind of mitochondrion not found in papillary muscle. No evidence of a transverse tubular system was found, but junctions of cisternae of the sarcoplasmic reticulum and the sarcolemma, peripheral couplings, were present. The electrophysiological implications of the absence of transverse tubules are discussed. The cisternae of the couplings showed periodic tubular extensions toward the sarcolemma. A regularly spaced array of Z line-like material was observed, suggesting a possible mechanism for sarcomere growth.

scholarly journals CHANGES OF MORPHOFUNCTIONAL STATE OF THYROID GLAND IN HYPOTHYROID RATS IN CONDITIONS OF INFLUENCE LONG-TERM STRESS

2019 ◽  
Vol 15 (1-2) ◽  
pp. 20-24
Author(s):  
N.G. Pobigun
Keyword(s):  
Electron Microscopy ◽  
Thyroid Gland ◽  
Blood Plasma ◽  
Light And Electron Microscopy ◽  
Structural Features ◽  
Thyroid Stimulating Hormone ◽  
Stress Factors ◽  
Male Rats ◽  
In Blood Plasma

Relevance. The chronic stress influences on increasing of frequency of thyroid pathology together with other factors (decreased iodine intake in food, harmful factors of external environment, high technogenic loading, depravation of general ecological state, violation of structure of nutrition). The changes of hypothalamus-hypophysis-thyroid gland axis at stress is not enough agreed because of influence stressful factors with different character and duration. Objective is study of influence of chronic emotional painful stress (CS) on the changes of morphofunctional state of thyroid gland (TG) on the background of experimental hypothyroidism (EH). Materials and methods. Experiments were performed on 48 white laboratory sex matured male rats. Animals were divided on four groups: the fist – intact animals; the second – animals with EH; the third – animals under influence of CS; the fourth – animals with EH under action of CS. The EH was modeled by everyday addition of mercazolilum (dose 10mg/kg) to drinking water during 15 days. The CS was modeled by 1 hour per day during 30 days. The functional activity of TG was estimated by the concentration of thyroid stimulating hormone (TSH), triiodothyronine (T3), thyroxin (T4) in blood plasma and calculation of thyroid index (TI). The morphological state of TG was studied by light and electron microscopy. The statistical analysis of results was processed using Student’s test with Bonferroni-Holm correction in program Statistica 6.0. The differences were statistical significant at р<0,05.             Results. The long-term influence of stress factors caused significant decreasing of level of thyroid hormones in blood plasma in comparison to intact animals. The data of light and electron microscopy of TG of rats under influence of CS confirm biochemical changes and detect signs of decreasing of secretory function. On the background of action of mercazolilum the long-term stress caused to more substantial changes of functional state of TG (significant increasing of level of TSH, decreasing of content of T4 and TI) in comparison to data of animals with EH. The structural features of TG of animals with EH under influence of CS indicate on suppression of function. Conclusions. Decreasing of synthesis of hormones by TG in rats at conditions of CS was detected. The long-term action of stress on background of hypothyroidism causes to more substantial depravation of thyroid profile.

Differentiation of Fiber Types in a Mammalian Extraocular Muscle

1981 ◽  
Vol 39 ◽  
pp. 506-507
Author(s):  
Asish C. Nag ◽  
Mei Cheng
Keyword(s):  
Electron Microscopy ◽  
Fiber Type ◽  
Muscle Fibers ◽  
Light And Electron Microscopy ◽  
Rectus Muscle ◽  
Fiber Types ◽  
Thin Sections ◽  
Superior Rectus ◽  
Adult Cat ◽  
Superior Rectus Muscle

The mammalian extraocular muscles possess greater variation in structural and physiological properties than any other muscle. Superior rectus muscle of the adult cat and rat contains five morphological fiber types. The differentiation of these fiber types in the embryonic and postnatal rats was studied by light and electron microscopy, mapping the distribution of each developing fiber type with its distinctive features.A mixture of 4% paraformaldehyde and 4% glutaraldehyde was perfused through the superior rectus muscle of rats ranging from 18-day embryos through 4-week postnatal anesthetized animals. Muscles were removed, kept overnight in 4% glutaraldehyde, and processed for electron microscopy using standard methods of OsO4 postfixation and araldite embedding. Thick and thin sections were cut. Thick transverse sections were photographed, and maps of muscle fibers were prepared. In order to identify the fibers and their exact locations, electron micrographs of fibers were taken in conjunction with the light micrographs.The muscle fibers in the 18-day embryos did not differentiate into the specific structural fiber types (Fig. 1) that were observed in the adult muscle.

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