Degeneration of leaf cells resulting from starvation after excision. I. Electron microscopic observations

1970 ◽  
Vol 48 (11) ◽  
pp. 1913-1922 ◽  
Author(s):  
H. W. J. Ragetli ◽  
M. Weintraub ◽  
Esther Lo
Keyword(s):  
Nuclear Membrane ◽  
Nuclear Material ◽  
Ultrastructural Changes ◽  
Cell Aging ◽  
Starvation Stress ◽  
Electron Microscopic ◽  
Nicotiana Glutinosa ◽  
Mesophyll Cells ◽  
Unequal Distribution ◽  
3 Dimensional

Mesophyll cells of Nicotiana glutinosa exposed to starvation in the light after leaf excision showed the following major changes: vacuolation of the cytoplast; rearrangement of chloroplast and nuclear material; accumulation of cytoplasmic crystals and of starch; evagination and increased perforation of the nuclear membrane; and lysis of the tonoplast. Rearrangement of chloroplast material resulted in extended, 3-dimensional arrays (pseudocrystalline bodies), composed of electron-dense globules 85–100 Å in diameter. The ultrastructural degeneration of cells within a leaf was unsynchronized, and the sequence of degenerative intracellular events was not fixed. These observations are compatible with an unequal distribution of "essential" metabolites among those cells. Cells suffering from starvation stress showed ultrastructural changes not observed in cells of aging attached leaves and vice versa. Thus, starvation stress does not merely accelerate the process of cell-aging, as it operates in attached leaves.

Fine structure of sunflower crown gall tissue

1970 ◽  
Vol 48 (8) ◽  
pp. 1455-1458 ◽  
Author(s):  
M. S. Manocha
Keyword(s):  
Crown Gall ◽  
Electron Microscopic Examination ◽  
Mesophyll Cell ◽  
Ultrastructural Changes ◽  
Bacterial Inoculation ◽  
Electron Microscopic ◽  
Mesophyll Cells ◽  
Thin Sections ◽  
Gall Tissue ◽  
Crown Gall Tissue

Electron microscopic examination of thin sections from sunflower crown gall tissue, induced by Agrobacterium tumefaciens, revealed certain details about its intracellular organization not previously reported. Tumor tissue showed a marked increase in the number of ribosomes, endoplasmic reticulum, and Golgi dictyosomes, over that of normal mesophyll cells. Mitochondria and chloroplasts did not show any detectable change. Crystalline bodies, consisting of a lattice surrounded by a unit membrane, were frequently observed in tumorous cells. The nucleoli of tumor cells contained vacuoles and were clearly differentiated into two zones, pars amorpha and nucleolonema. The possible significance of these ultrastructural changes has been discussed. Small vesicle-like bodies were observed in the nuclei of mesophyll cells 4 days after bacterial inoculation. Whether or not these vesicle-like bodies are responsible for the transformation of a normal mesophyll cell to a fully autonomous tumor cell is not known, but the possibility is an intriguing one.

Ultrastructure and Senescence in an Achloroplastic Mutant of Hordeum vulgare L. cv. Dyan

1992 ◽  
Vol 50 (1) ◽  
pp. 844-845
Author(s):  
R.H.M. Cross ◽  
C.E.J. Botha ◽  
A.K. Cowan ◽  
B.J. Hartley
Keyword(s):  
Cell Wall ◽  
Hordeum Vulgare ◽  
Leaf Tissue ◽  
Ultrastructural Changes ◽  
Hordeum Vulgare L ◽  
Mesophyll Cells ◽  
Lethal Mutant ◽  
Cytoplasmic Matrix ◽  
Close Proximity ◽  
Pinocytotic Vesicles

Senescence is an ordered degenerative process leading to death of individual cells, organs and organisms. The detection of a conditional lethal mutant (achloroplastic) of Hordeum vulgare has enabled us to investigate ultrastructural changes occurring in leaf tissue during foliar senescence.Examination of the tonoplast structure in six and 14 day-old mutant tissue revealed a progressive degeneration and disappearance of the membrane, apparently starting by day six in the vicinity of the mitochondria associated with the degenerating proplastid (Fig. 1.) where neither of the plastid membrane leaflets is evident (arrows, Fig. 1.). At this stage there was evidence that the mitochondrial membranes were undergoing retrogressive changes, coupled with disorganization of cristae (Fig. 2.). Proplastids (P) lack definitive prolamellar bodies. The cytoplasmic matrix is largely agranular, with few endoplasmic reticulum (ER) cisternae or polyribosomal aggregates. Interestingly, large numbers of actively-budding dictysomes, associated with pinocytotic vesicles, were observed in close proximity to the plasmalemma of mesophyll cells (Fig. 3.). By day 14 however, mesophyll cells showed almost complete breakdown of subcellular organelle structure (Fig. 4.), and further evidence for the breakdown of the tonoplast. The final stage of senescence is characterized by the solubilization of the cell wall due to expression and activity of polygalacturonase and/or cellulose. The presence of dictyosomes with associated pinocytotic vesicles formed from the mature face, in close proximity to both the plasmalemma and the cell wall, would appear to support the model proposed by Christopherson for the secretion of cellulase. This pathway of synthesis is typical for secretory glycoproteins.

Morphologic alteration in the muscles of patients with hypokalemic periodic paralysis or myopathy

1990 ◽  
Vol 48 (3) ◽  
pp. 222-223
Author(s):  
T. Shimizu ◽  
Y. Muranaka ◽  
I. Ohta ◽  
N. Honda
Keyword(s):  
Clinical Manifestations ◽  
Quadriceps Muscle ◽  
Honeycomb Structure ◽  
Periodic Paralysis ◽  
Ultrastructural Changes ◽  
Hypokalemic Periodic Paralysis ◽  
Electron Microscopic ◽  
Tubular Aggregates ◽  
Hypokalemic Myopathy ◽  
Transmission Electron

There have been many reports on ultrastructural alterations in muscles of hypokalemic periodic paralysis (hpp) and hypokalemic myopathy(hm). It is stressed in those reports that tubular structures such as tubular aggregates are usually to be found in hpp as a characteristic feature, but not in hm. We analyzed the histological differences between hpp and hm, comparing their clinical manifestations and morphologic changes in muscles. Materials analyzed were biopsied muscles from 18 patients which showed muscular symptoms due to hypokalemia. The muscle specimens were obtained by means of biopsy from quadriceps muscle and fixed with 2% glutaraldehyde (pH 7.4) and analyzed by ordinary method and modified Golgimethod. The ultrathin section were examined in JEOL 200CX transmission electron microscopy.Electron microscopic examinations disclosed dilated t-system and terminal cistern of sarcoplasmic reticulum (SR)(Fig 1), and an unique structure like “sixad” was occasionally observed in some specimens (Fig 2). Tubular aggregates (Fig 3) and honeycomb structure (Fig 4) were also common characteristic structures in all cases. These ultrastructural changes were common in both the hypokalemic periodic paralysis and the hypokalemic myopathy, regardless of the time of biopsy or the duration of hypokalemia suffered.

Correlative transmission and high-resolution scanning electron microscopic studies on pituitary cells

1990 ◽  
Vol 48 (3) ◽  
pp. 20-21
Author(s):  
S. Tai
Keyword(s):  
Cell Types ◽  
Depth Of Field ◽  
Secretory Cells ◽  
Specific Cell ◽  
Pituitary Cells ◽  
Electron Microscopic ◽  
3 Dimensional ◽  
Microscopic Studies ◽  
Structure And Activity ◽  
Intracellular Structure

Extensive cytological and histological research, correlated with physiological experimental analysis, have been done on the anterior pituitaries of many different vertebrates which have provided the knowledge to create the concept that specific cell types synthesize, store and release their specific hormones. These hormones are stored in or associated with granules. Nevertheless, there are still many doubts - that need further studies, specially on the ultrastructure and physiology of these endocrine cells during the process of synthesis, transport and secretion, whereas some new methods may provide the information about the intracellular structure and activity in detail.In the present work, ultrastructural study of the hormone-secretory cells of chicken pituitaries have been done by using TEM as well as HR-SEM, to correlate the informations obtained from 2-dimensional TEM micrography with the 3-dimensional SEM topographic images, which have a continous surface with larger depth of field that - offers the adventage to interpretate some intracellular structures which were not possible to see using TEM.

Serial thin sectioning for pre- and post-embedding immunohistochemistry: Achieving consistent and reliable results for a 3-D reconstruction

1993 ◽  
Vol 51 ◽  
pp. 328-329
Author(s):  
Antonia M. Milroy
Keyword(s):  
Nervous System ◽  
Computer Assisted ◽  
Serial Sectioning ◽  
Electron Microscopic ◽  
High Quality ◽  
New Techniques ◽  
3 Dimensional ◽  
Multiple User ◽  
Thin Sectioning ◽  
Subcellular Level

In recent years many new techniques and instruments for 3-Dimensional visualization of electron microscopic images have become available. Higher accelerating voltage through thicker sections, photographed at a tilt for stereo viewing, or the use of confocal microscopy, help to analyze biological material without the necessity of serial sectioning. However, when determining the presence of neurotransmitter receptors or biochemical substances present within the nervous system, the need for good serial sectioning (Fig. 1+2) remains. The advent of computer assisted reconstruction and the possibility of feeding information from the specimen viewing chamber directly into a computer via a camera mounted on the electron microscope column, facilitates serial analysis. Detailed information observed at the subcellular level is more precise and extensive and the complexities of interactions within the nervous system can be further elucidated.We emphasize that serial ultra thin sectioning can be performed routinely and consistently in multiple user electron microscopy laboratories. Initial tissue fixation and embedding must be of high quality.

HISTOMETRIC AND ULTRASTRUCTURAL ORGANIZATION OF THE NERVIMUSCULAR TERMINALS OF SKELETAL MUSCLES AT A HYPOKINESIA

2019 ◽  
pp. 55-63
Author(s):  
Z. M. Yaschyshyn ◽  
S. L. Popel
Keyword(s):  
Skeletal Muscles ◽  
Structural Adjustment ◽  
Muscle Fibers ◽  
Electron Microscopic Examination ◽  
Nerve Fibers ◽  
Ultrastructural Changes ◽  
Ultrastructural Organization ◽  
Electron Microscopic ◽  
Myelinated Nerve ◽  
Male Wistar Rats

The aim: to study the dynamics of histological and ultrastructural changes in muscle fibers and their neuromuscular endings under conditions of prolonged hypokinesia at different stages of ontogenesis. Methods. Studied skeletal muscles and their peripheral nervous apparatus of laboratory male Wistar rats aged 30 to 270 days. The restriction of motor activity was carried out in special canister cells for 30, 60, 90, and 240 days (5 animals for each term). To determine the type of muscle fiber, the Nahlas histochemical method was used, the Kulchitsky method was used to detect myelinated nerve fibers, the Bilshovsky-Gros method and the electron microscopic method to identify neuromuscular endings. Results. The data of histological and electron microscopic examination of skeletal muscle fibers and their neuromuscular endings under conditions of prolonged hypokinesia indicate their regular restructuring during the development of muscles, the formation of their synapses and structures that are associated with them at different stages of ontogenesis. Conclusion. The study provides an in-depth understanding of the relative frequency and nature of the disturbance of the neuromuscular endings during prolonged hypokinesia and its effect on the dynamics of structural adjustment of individual types of muscle fibers in ontogenesis.

HISTOMETRIC AND ULTRASTRUCTURAL ORGANIZATION OF THE NERVIMUSCULAR TERMINALS OF SKELETAL MUSCLES AT A HYPOKINESIA

2019 ◽  
pp. 55-63
Author(s):  
Z. M. Yaschyshyn ◽  
S. L. Popel
Keyword(s):  
Skeletal Muscles ◽  
Structural Adjustment ◽  
Muscle Fibers ◽  
Electron Microscopic Examination ◽  
Nerve Fibers ◽  
Ultrastructural Changes ◽  
Ultrastructural Organization ◽  
Electron Microscopic ◽  
Myelinated Nerve ◽  
Male Wistar Rats

The aim: to study the dynamics of histological and ultrastructural changes in muscle fibers and their neuromuscular endings under conditions of prolonged hypokinesia at different stages of ontogenesis. Methods. Studied skeletal muscles and their peripheral nervous apparatus of laboratory male Wistar rats aged 30 to 270 days. The restriction of motor activity was carried out in special canister cells for 30, 60, 90, and 240 days (5 animals for each term). To determine the type of muscle fiber, the Nahlas histochemical method was used, the Kulchitsky method was used to detect myelinated nerve fibers, the Bilshovsky-Gros method and the electron microscopic method to identify neuromuscular endings. Results. The data of histological and electron microscopic examination of skeletal muscle fibers and their neuromuscular endings under conditions of prolonged hypokinesia indicate their regular restructuring during the development of muscles, the formation of their synapses and structures that are associated with them at different stages of ontogenesis. Conclusion. The study provides an in-depth understanding of the relative frequency and nature of the disturbance of the neuromuscular endings during prolonged hypokinesia and its effect on the dynamics of structural adjustment of individual types of muscle fibers in ontogenesis.

Effects of Combination Chemical Peel on Facial Photodamaged Skin

1998 ◽  
Vol 15 (3) ◽  
pp. 263-271 ◽  
Author(s):  
May H. El Samahy ◽  
Mohamed M. Ghoz ◽  
Naglaa Ramzy
Keyword(s):  
Glycolic Acid ◽  
Electron Microscopic Examination ◽  
Ultrastructural Changes ◽  
Elastic Fibers ◽  
Electron Microscopic ◽  
Trichloracetic Acid ◽  
Age Related ◽  
Photodamaged Skin ◽  
Microscopic Studies ◽  
Activated Fibroblasts

Introduction: Chemical peeling involves the topical application of a wounding agent with the goal of effecting an organized regeneration of the skin. The histologic and ultrastructural features of actinic and age-related damage include structural abnormalities that disrupt normal epidermal and dermal architecture. The purpose of the present study is to evaluate the clinical and histologic effects of an enhanced medium-depth peel on photodamaged skin. We aimed to correlate the clinical and histologic findings with the ultrastructural changes occurring after the peel. These ultrastructural features are supposed to be more precise and informative than the clinical or histological response. They may also be employed as markers of peel response. Materials and Methods: In the present study, five patients with actinically damaged skin underwent enhanced medium-depth peels using 70% glycolic acid and 35% trichloracetic acid. Biopsy specimens were taken before the peel and 3 months after the peel for histologic and electron microscopic examination. Results: Clinical resolution of actinic damage corresponded with restoration of epidermal polarity. Characteristic histologic and ultrastructural features of the skin after peeling include markedly decreased epidermal intracytoplasmic vacuoles, decreased elastic fibers, increased activated fibroblasts, and organized parallel arrays of collagen fibrils. The diameters of individual fibrils are consistent with recent production of collagen by activated fibroblasts. Conclusion: Glycolic acid—tricholoro-acetic acid (GA-TCA) is an effective combination for a medium-depth peel in photodamaged skin both clinically and histologically. Electron microscopic studies following medium-depth peels reveal changes more profound than those seen histologically. The characteristic changes occurring in the keratinocytes, collagen, and elastic fibrils may be considered as guidelines or markers of the peel response.

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.

PAHs accumulation in soil-plant system in Atamanskoe lake bottom sediments in the long-term chemical contamination effect

2021 ◽  
Author(s):  
Andrey Barbashev ◽  
Abdulmalik Batukaev ◽  
Svetlana Sushkova ◽  
Tatiana Minkina ◽  
Sarieh Tarigholizadeh ◽  
...  
Keyword(s):  
Ultrastructural Changes ◽  
Monitoring Site ◽  
Chemical Contamination ◽  
Russian Science ◽  
Electron Microscopic ◽  
Lake Bottom ◽  
Polycyclic Aromatic ◽  
Lake Bottom Sediments ◽  
High Level ◽  
Cellular Organelles

<p>The concentrations of 16 priority polycyclic aromatic hydrocarbons (PAHs) in soils, under- and above-ground tissues of reed (Phragmites australis) on monitoring plots in the zone of industrial sewage tanks and sludge reservoirs in the city of Kamensk-Shakhtinskyi (southern Russia, Rostov Region), were determined. The total PAHs concentration in soil of monitoring site D3 (4229.4 ± 5.7<sup></sup>µg kg<sup>-1</sup>) was significantly higher than those in monitoring sites: D4 (3873.7 ± 17.1 µg kg<sup>-1</sup>), TR1 (2217.3 ± 9.1<sup></sup>µg kg<sup>-1</sup>), 43 (2001.1 ± 13.0<sup></sup>µg kg<sup>-1</sup>), and also D0 (140.4 ± 1.0<sup></sup>µg kg<sup>-1</sup>) plots. Accordingly, the maximum accumulation was found for phenanthrene among the 16 priority PAHs in the most of the soil and plants samples. It was determined the PAHs pollution effect in the studied monitoring sites on cellular and sub-cellular organelles changes of P. australis. The data received shows that increasing of PAHs contamination negatively affected on the cellular and sub-cellular organelles changes of the studied pants. Using of electron-microscopic method for plants sub-cellular structure showed ultrastructural changes in the cell membranes, and the main cytoplasmic organelles of plant cells. It was established the P. australis had a high level of adaptation to the effect of stressors by using of tissue and cell levels. In general, the detected sub-cellular alterations under the PAHs effect were possibly connected to changes in biochemical and histochemical parameters as a response for reactive oxygen species and also as a protective response against oxidative stress. The results received carry in innovative findings for cellular and sub-cellular changes in plants exposed to 16 priority PAHs as very persistent and toxic contaminants.</p><p>The research was financially supported by the Russian Science Foundation project no. 19-74-10046.</p>

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