Seasonal ultrastructural changes in the cambial zone of beech (Fagus sylvatica) grown at two different altitudes

IAWA Journal ◽  
2011 ◽  
Vol 32 (4) ◽  
pp. 443-459 ◽  
Author(s):  
Peter Prislan ◽  
Uwe Schmitt ◽  
Gerald Koch ◽  
Jožica Gričar ◽  
Katarina Čufar
Keyword(s):  
Fagus Sylvatica ◽  
Cell Walls ◽  
Structural Changes ◽  
Cambial Activity ◽  
Ultrastructural Changes ◽  
Seasonal Patterns ◽  
Cell Divisions ◽  
Cambial Zone ◽  
Cambial Cells ◽  
Different Altitudes

Seasonal structural changes of cambial cells in mature beech (Fagus sylvatica L.) trees growing at elevations of 400 m a.s.l. (lowland) and 1200 m a.s.l. (mountains) are presented on the basis of light (LM) and electron microscopy (TEM). For LM, samples from trees were collected at weekly intervals and for TEM at two-month intervals from March till September, 2008. LM enabled us to follow the production of new xylem and phloem cells that lasted for 16.5 ± 3.7 weeks at the lowland site and for 10.7 ± 1.3 weeks in the mountains. TEM revealed differences in ultrastructure of cambial cells in the phases of dormancy, reactivation, activity and transition to dormancy. The seasonal patterns of ultrastructural changes in cambial cells were similar at both sites but their timing was different. TEM revealed changes in the fine structure of cambial cells, indicating their activation in spring and the earliest stages of cell divisions and development of new cell walls. When using LM, the onset of cambial activity could be observed one month later, compared with TEM. LM therefore enabled us to follow cambial productivity but not the activity and related cytoplasmic modifications during reactivation.

Early changes in the radial walls of storied fusiform cambial cells during fiber differentiation

IAWA Journal ◽  
2011 ◽  
Vol 32 (3) ◽  
pp. 333-340 ◽  
Author(s):  
Karumanchi S. Rao ◽  
Jong Sik Kim ◽  
Yoon Soo Kim
Keyword(s):  
Cell Wall ◽  
Middle Lamella ◽  
Ultrastructural Changes ◽  
Pectic Polysaccharides ◽  
Axial Extension ◽  
Cambial Zone ◽  
Entire Cell ◽  
Cambial Cells ◽  
Wall Loosening ◽  
Hydrolysis Of

There is little information about the ultrastructural changes taking place in the radial walls of fusiform cambial cells during differentiation into xylem derivatives. The present study reports the early events occurring in the radial walls of fusiform cambial cells (FCCs) during fiber elongation in Holoptelea integrifolia, a deciduous tropical tree with storied cambium. Serial tangential sections of active cambial zone cells demonstrate the initiation of intrusive cell wall elongation from gabled ends of FCCs during fiber development. The elongation at the tip is followed by the axial extension of the entire cell. It was evident from ultrastructural observations made on the tangential sections that the thick beaded pattern on FCC radial walls disappear following cell elongation. PATAg staining, specific for wall polysaccharides showed that, initially, the beaded structures undergo wall loosening following hydrolysis of pectic polysaccharides in the middle lamella. Then the loosened primary walls come together with the axial extension of cells. Thus the beaded nature disappears in the differentiating cambial cells. This study highlights the cell wall changes associated with the differentiation of FCCs into fibers.

Fine Structural Changes in the Microvasculature of the Mouse Pinna: Aging and Radiation Injury

1974 ◽  
Vol 32 ◽  
pp. 54-55
Author(s):  
S. Phyllis Steamer ◽  
Rosemarie L. Devine
Keyword(s):  
Structural Changes ◽  
Radiation Treatment ◽  
Arterial Stenosis ◽  
Ultrastructural Changes ◽  
Vascular Effects ◽  
Microvascular Changes ◽  
Surrounding Connective Tissue ◽  
Fission Neutrons ◽  
Total Body

The importance of radiation damage to the skin and its vasculature was recognized by the early radiologists. In more recent studies, vascular effects were shown to involve the endothelium as well as the surrounding connective tissue. Microvascular changes in the mouse pinna were studied in vivo and recorded photographically over a period of 12-18 months. Radiation treatment at 110 days of age was total body exposure to either 240 rad fission neutrons or 855 rad 60Co gamma rays. After in vivo observations in control and irradiated mice, animals were sacrificed for examination of changes in vascular fine structure. Vessels were selected from regions of specific interest that had been identified on photomicrographs. Prominent ultrastructural changes can be attributed to aging as well as to radiation treatment. Of principal concern were determinations of ultrastructural changes associated with venous dilatations, segmental arterial stenosis and tortuosities of both veins and arteries, effects that had been identified on the basis of light microscopic observations. Tortuosities and irregularly dilated vein segments were related to both aging and radiation changes but arterial stenosis was observed only in irradiated animals.

scholarly journals Establishment of an in vitro model for analyzing mitochondrial ultrastructure in PRKN-mutated patient iPSC-derived dopaminergic neurons

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Mutsumi Yokota ◽  
Soichiro Kakuta ◽  
Takahiro Shiga ◽  
Kei-ichi Ishikawa ◽  
Hideyuki Okano ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Dopaminergic Neurons ◽  
Structural Changes ◽  
In Vitro Model ◽  
Induced Pluripotent Stem Cell ◽  
Substantia Nigra Pars Compacta ◽  
Ultrastructural Changes ◽  
Mitochondrial Morphology ◽  
Vitro Model

AbstractMitochondrial structural changes are associated with the regulation of mitochondrial function, apoptosis, and neurodegenerative diseases. PRKN is known to be involved with various mechanisms of mitochondrial quality control including mitochondrial structural changes. Parkinson’s disease (PD) with PRKN mutations is characterized by the preferential degeneration of dopaminergic neurons in the substantia nigra pars compacta, which has been suggested to result from the accumulation of damaged mitochondria. However, ultrastructural changes of mitochondria specifically in dopaminergic neurons derived from iPSC have rarely been analyzed. The main reason for this would be that the dopaminergic neurons cannot be distinguished directly among a mixture of iPSC-derived differentiated cells under electron microscopy. To selectively label dopaminergic neurons and analyze mitochondrial morphology at the ultrastructural level, we generated control and PRKN-mutated patient tyrosine hydroxylase reporter (TH-GFP) induced pluripotent stem cell (iPSC) lines. Correlative light-electron microscopy analysis and live cell imaging of GFP-expressing dopaminergic neurons indicated that iPSC-derived dopaminergic neurons had smaller and less functional mitochondria than those in non-dopaminergic neurons. Furthermore, the formation of spheroid-shaped mitochondria, which was induced in control dopaminergic neurons by a mitochondrial uncoupler, was inhibited in the PRKN-mutated dopaminergic neurons. These results indicate that our established TH-GFP iPSC lines are useful for characterizing mitochondrial morphology, such as spheroid-shaped mitochondria, in dopaminergic neurons among a mixture of various cell types. Our in vitro model would provide insights into the vulnerability of dopaminergic neurons and the processes leading to the preferential loss of dopaminergic neurons in patients with PRKN mutations.

scholarly journals Overview of Popular Techniques of Raman Spectroscopy and Their Potential in the Study of Plant Tissues

Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1537
Author(s):  
Aneta Saletnik ◽  
Bogdan Saletnik ◽  
Czesław Puchalski
Keyword(s):  
Raman Spectroscopy ◽  
Cell Walls ◽  
Structural Changes ◽  
Spatial Information ◽  
Technological Development ◽  
Analytical Techniques ◽  
High Sensitivity ◽  
Plant Tissues ◽  
Wide Range ◽  
Identification Technique

Raman spectroscopy is one of the main analytical techniques used in optical metrology. It is a vibration, marker-free technique that provides insight into the structure and composition of tissues and cells at the molecular level. Raman spectroscopy is an outstanding material identification technique. It provides spatial information of vibrations from complex biological samples which renders it a very accurate tool for the analysis of highly complex plant tissues. Raman spectra can be used as a fingerprint tool for a very wide range of compounds. Raman spectroscopy enables all the polymers that build the cell walls of plants to be tracked simultaneously; it facilitates the analysis of both the molecular composition and the molecular structure of cell walls. Due to its high sensitivity to even minute structural changes, this method is used for comparative tests. The introduction of new and improved Raman techniques by scientists as well as the constant technological development of the apparatus has resulted in an increased importance of Raman spectroscopy in the discovery and defining of tissues and the processes taking place in them.

Ultrastructural changes of Basolateral Amygdaloid nuclei in the Sprague Dawley rats brain following exposure to naphthalene balls

2021 ◽  
Vol 12 (2) ◽  
pp. 1272-1275
Author(s):  
Angu Bala Ganesh K S V ◽  
Sujeet Shekhar Sinha ◽  
Kesavi Durairaj ◽  
Abdul Sahabudeen K
Keyword(s):  
Structural Changes ◽  
Corn Oil ◽  
Chromatin Condensation ◽  
Ultrastructural Changes ◽  
High Dose ◽  
Model Group ◽  
Sprague Dawley ◽  
Sprague Dawley Rats ◽  
The Brain ◽  
Amygdaloid Nuclei

Naphthalene is a bicyclic aromatic constituent commonly used in different domestic and marketable applications comprising soil fumigants, lavatory scent disks and mothballs. Accidentally, workers, children and animals are exposed to naphthalene mothballs, so there is a need to study the pathology behind this chemical toxicity. The current study was carried out to assess the ultra structural changes of basolateral amygdaloid nuclei in the Sprague Dawley rats brain in association to naphthalene toxicity. The toxicity model group was administered with naphthalene (200 and 400mg) using corn oil as a vehicle for 28 days. The post delayed toxicity of naphthalene high dose ingestion was also assessed in rats. After the experimental period, the brain tissue was processed to observe the ultra structural changes using a transmission electron microscope. The alterations in cell organelles, nuclei damage, mitochondrial swelling, chromatin condensation suggested naphthalene induced damage in the neurons of the basolateral amygdala of the brain in the toxicity model group. These experimental trials provide information about the alert of mothball usage in the home and identify risks linked with accidental exposure and misuse.

scholarly journals Ultrastructural Adaptation of the Cardiomyocyte to Chronic Mitral Regurgitation

2021 ◽  
Vol 8 ◽  
Author(s):  
Daniella Corporan ◽  
Ana Segura ◽  
Muralidhar Padala
Keyword(s):  
Mitral Regurgitation ◽  
Structural Changes ◽  
Recovery Of Function ◽  
Wall Stress ◽  
Ultrastructural Changes ◽  
Sprague Dawley ◽  
Cross Sectional ◽  
Systolic Volume ◽  
The Impact ◽  
Time Point

Introduction: Mitral regurgitation (MR) imposes volume overload on the left ventricle (LV) and elevates wall stress, triggering its adverse remodeling. Pronounced LV dilation, minimal wall thinning, and a gradual decline in cardiac ejection fraction (EF) are observed. The structural changes in the myocardium that define these gross, organ level remodeling are not known. Cardiomyocyte elongation and slippage have both been hypothesized, but neither are confirmed, nor are the changes to the cardiomyocyte structure known. Using a rodent model of MR, we used immunohistochemistry and transmission electron microscopy (TEM) to describe the ultrastructural remodeling of the cardiomyocyte.Methods: Twenty-four male Sprague-Dawley rats (350–400 g) were assigned to two groups: group (1) rats induced with severe MR (n = 18) and group (2) control rats that were healthy and age and weight matched (n = 6). MR was induced in the beating heart using a 23-G ultrasound-guided, transapical needle to perforate the anterior mitral leaflet, and the rats were followed to 2, 10, and 20 weeks (n = 6/time-point). Echocardiography was performed to quantify MR severity and to measure LV volume and function at each time-point. Explanted myocardial tissue were examined with TEM and immunohistochemistry to investigate the ultrastructural changes.Results: MR induced rapid and significant increase in end-diastolic volume (EDV), with a 50% increase by 2 weeks, compared with control. Rise in end-systolic volume (ESV) was more gradual; however, by 20 weeks, both EDV and ESV in MR rats were increased by 126% compared with control. A significant decline in EF was measured at 10 weeks of MR. At the ultrastructural level, as early as 2 weeks after MR, cardiomyocyte elongation and increase in cross-sectional area were observed. TEM depicted sarcomere shortening, with loss of Z-line and I-band. Desmin, a cytoskeletal protein that is uniformly distributed along the length of the cardiomyocyte, was disorganized and localized to the intercalated disc, in the rats induced with MR and not in the controls. In the rats with MR, the linear registry of the mitochondrial arrangement along the sarcomeres was lost, with mitochondrial fragmentation, aggregation around the nucleus, and irregularities in the cristae.Discussion: In the setting of chronic mitral regurgitation, LV dilatation occured by cardiomyocyte elongation, which manifests at the subcellular level as distinct ultrastructural alterations of the sarcomere, cytoskeleton, and mitochondria. Since the cytoskeleton not only provides tensegrity but has functional consequences on myocyte function, further investigation into the impact of cytoskeletal remodeling on progressive heart failure or recovery of function upon correcting the valve lesion are needed.

Conversaziones 1974

1975 ◽  
Vol 29 (2) ◽  
pp. 163-171
Keyword(s):  
Electron Microscopy ◽  
Fine Structure ◽  
Cell Walls ◽  
Structural Changes ◽  
Vascular Tissue ◽  
Root Systems ◽  
Plant Roots ◽  
Tracer Studies ◽  
Water Move ◽  
Intact Root

CONVERSAZIONES were held this year on 9 May and 27 June. At the first conversazione twenty-seven exhibits and two films were shown. The fine structure of plant roots in relation to transport of nutrient ions and water was demonstrated by Dr D. T. Clarkson of the A.R.C. Letcombe Laboratory, Wantage and Dr A. W. Robards of the Department of Biology, University of York. Two major pathways by which nutrients and water move radially across the cortex towards the central vascular tissue have been distinguished by the use of tracer studies of adsorption by different zones of intact root systems, microautoradiography and electron microscopy. Movement can be apoplastic through cell walls, or symplastic between cells joined by plasmodesmata. As the root ages, structural changes in the endodermis reduce movement in the former pathway but the symplast is not interrupted by the elaboration of endodermal walls because plasmodesmatal connexions remain intact. These observations help explain the contrasting extent to which different ions and water reach the shoot from young and mature parts of root systems.

Effect of cambial dormancy state on the transport of [1-14C]indol-3-ylacetic acid in Abies balsamea shoots

1981 ◽  
Vol 59 (3) ◽  
pp. 342-348 ◽  
Author(s):  
C. H. A. Little
Keyword(s):  
Abies Balsamea ◽  
Cambial Activity ◽  
Controlled Environment ◽  
Long Distance ◽  
Dormant Period ◽  
Cambial Zone ◽  
Time Required ◽  
Ylacetic Acid ◽  
Exogenous Iaa

Dormant attached or detached shoots of balsam fir were naturally or artificially chilled to induce different states along the rest–quiescence continuum. At the end of the chilling pretreatment, the shoots either were left intact or were debudded and treated with indol-3-ylacetic acid (IAA). The shoots were placed under controlled-environment conditions favorable for growth, and at intervals thereafter, a pulse of [1-14C]IAA was applied to the shoot apex. Measured at the end of the chilling pretreatment, [14C]IAA velocity and flux decreased with increasing duration of chilling (i.e., as rest graded into quiescence). The time required to commence cambial growth and to attain maximum rates of cambial activity and [14C]IAA transport also decreased as rest changed to quiescence. Transport in actively growing shoots exceeded that in quiescent shoots, but was similar to that in resting shoots. The [14C]IAA pulse moved basipetally as unchanged IAA, was blocked by a bark + cambium girdle, and was inhibited by abscisic acid and long-term application of exogenous IAA. The results indicate that: (1) the long-distance, cambium-located, IAA transport system demonstrated in dicotyledonous species also operates in conifers, (2) during the dormant period changes occur in [14C]IAA transport and in the cambial response to exogenous IAA, (3) the change in [14C]IAA transport is the result of change in the transporting capability of cells in the cambial zone, and (4) the change in [14C]IAA transport is not the cause of the differential response of quiescent and resting cambia to exogenous IAA.

Ultrastructural Changes in Euglena After Ultraviolet Irradiation

1973 ◽  
Vol 13 (3) ◽  
pp. 799-809
Author(s):  
A. MICHAELS ◽  
A. GIBOR
Keyword(s):  
Ultraviolet Light ◽  
Ultraviolet Irradiation ◽  
Euglena Gracilis ◽  
Structural Changes ◽  
Ultrastructural Changes ◽  
Electron Microscopic ◽  
Bleaching Process ◽  
In Cells

The structural changes associated with the ultraviolet-induced bleaching of light-grown cells of Euglena gracilis were investigated. Our light- and electron-microscopic observations of the bleaching process indicate that there is a continuity of plastid structure in cells 5 generations after receiving a bleaching dose of ultraviolet light. There seems to be a continuous dilution of the plastid thylakoids and a decrease in plastid size in the bleaching cells. There also seems to be a change in the position of the plastids in relation to the mitochondria in the bleaching cells. The plastids and possibly the mitochondria are the only organelles which are affected by the ultraviolet irradiation. The continuity of plastids in bleaching cells of Euglena is discussed in relation to the proposed effect of the ultraviolet light.

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