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.

scholarly journals Beneficial effect of genistein on lowering blood pressure and kidney toxicity in fructose-fed hypertensive rats

2012 ◽  
Vol 109 (10) ◽  
pp. 1806-1812 ◽  
Author(s):  
Nallasamy Palanisamy ◽  
Anuradha C. Venkataraman
Keyword(s):  
Blood Pressure ◽  
Structural Changes ◽  
Ultrastructural Changes ◽  
Hypertensive Rats ◽  
Enos Expression ◽  
Electron Microscopic ◽  
Plasma Angiotensin ◽  
Enhanced Expression ◽  
Male Wistar Rats ◽  
Microscopic Studies

The study evaluates the effects of genistein on blood pressure (BP) and ultrastructural changes in kidney of fructose-fed hypertensive rats. Male Wistar rats were fed a diet containing 60 % starch or 60 % fructose as the source of carbohydrate. After 15 d, rats in each dietary group were divided into two groups and were treated with either genistein (1 mg/kg per d) in dimethylsulfoxide (DMSO) or 30 % DMSO alone. BP, pressor mechanisms, protein kinase C-βII (PKC-βII) expression, endothelial NO synthase (eNOS) expression and renal ultrastructural changes were evaluated after 60 d. Fructose-fed rats displayed significant elevation in BP and heart rate. Significant increase in plasma angiotensin-converting enzyme (ACE) activity, alterations in renal lipid profile, nitrite and kallikrein activity, enhanced expression of membrane-associated PKC-βII and decreased expression of eNOS were observed in them. Histology and electron microscopic studies showed structural changes in the kidney. Genistein administration lowered BP, restored ACE, PKC-βII and eNOS expression and preserved renal ultrastructural integrity. These findings demonstrate that genistein has effects on eNOS activity in renal cells, leading to eNOS activation and NO synthesis. These effects could have been mediated by activation of PKC-βII. The observed benefits of genistein make it a promising candidate for therapy of diabetic kidney disease.

scholarly journals The Morphological Assessment of Rats` Liver after the Introduction of the Nucleoside Reverse Transcriptase Inhibitor of Azidothymidine

2019 ◽  
pp. 61-67
Author(s):  
M. N. Kurbat ◽  
R. I. Kravchuk ◽  
O. B. Ostrovskaya
Keyword(s):  
Nucleoside Reverse Transcriptase Inhibitor ◽  
Structural Changes ◽  
Electron Microscopic Examination ◽  
Transcriptase Inhibitor ◽  
Ultrastructural Changes ◽  
Electron Microscopic ◽  
Structural And Functional Properties ◽  
Hepatotoxic Effect ◽  
Reverse Transcriptase Inhibitor ◽  
Morphological Assessment

Objective: to study the microscopic and ultrastructural changes in the liver of rats exposed to AZT. Material and methods. The histological and electron microscopic examination of the liver samples with mitochondrial morphometry has been performed. Results . The 7-day administration of AZT does not cause any significant structural changes in the liver. The exposure to the drug for 21 days leads to the development of moderate inflammatory and degenerative processes in the liver, including changes in the structure of hepatocyte mitochondria. Conclusion. One of the pathogenetic mechanisms of the hepatotoxic effect of AZT is its impact on the structural and functional properties of hepatocyte mitochondria.

scholarly journals Ultrastructural Changes in Chloroplasts in Harvested Broccoli Flower Buds During Senescence

HortScience ◽  
1995 ◽  
Vol 30 (4) ◽  
pp. 824C-824
Author(s):  
Hirofumi Terai ◽  
Hironobu Tsuchida ◽  
Masashi Mizuno ◽  
Yumi Fukui
Keyword(s):  
Structural Changes ◽  
Optical Microscope ◽  
Ultrastructural Changes ◽  
Scanning Electron Micrographs ◽  
Small Particles ◽  
Flower Buds ◽  
Electron Microscopic ◽  
Green Color ◽  
Polyethylene Bags ◽  
Scanning Electron

Green broccoli (Brassica oleracea L. Italica Group) flower heads were stored in perforated polyethylene bags at 20C. Green color of sepals in broccoli flower buds changed to yellow and individual flower buds wilted gradually during storage. Chlorophyllase activity in flower buds tended to increase and chlorophyll content decreased during senescence. Optical and scanning electron microscopic observations were conducted to elucidate the structural changes of chloroplasts in sepals of broccoli flower buds through the senescence. The chloroplasts observed with optical microscope were fine and green when the stage of broccoli flower buds was all green. However, at half-yellow stage, the shapes of chloroplasts obscured and the green color faded. After this stage, colored small particles appeared in the cells and the number of particles tended to increase as yellowing of the flower buds progressed through the senescence. Scanning electron micrographs indicated that the small particles were formed in the chloroplasts and come out from them with senescence followed by aggregation with each other.

Fine Structural Changes of the Porcine Oviductal Epithelium During Late and Term Pregnancy

1976 ◽  
Vol 34 ◽  
pp. 150-151
Author(s):  
R. K. Nayak ◽  
E. N. Albert
Keyword(s):  
Estrous Cycle ◽  
Early Pregnancy ◽  
Structural Changes ◽  
Ultrastructural Changes ◽  
Secretory Cells ◽  
Corpora Lutea ◽  
Term Pregnancy ◽  
Electron Microscopic ◽  
Uterine Tube ◽  
Microscopic Studies

The characteristic ultrastructural changes in the ciliated and secretory cells of the tubal epithelium of adult gilts during the estrous cycle have been described (1). Earlier light microscopic studies revealed that pregnancy inhibited the cyclic alterations in the tubes of the sow and the epithelium appeared to remain in the state which was found in the second week after ovulation, when the corpora lutea were full grown (2). Nayak and Zimmerman have presented limited electron microscopic studies of the porcine tubal epithelium during early pregnancy (3) . To the best of our knowledge, no electron microscopic studies of the porcine uterine tube epithelium during late and term pregnancy have been reported.

Ultrastructural Changes in Pig Hepatocytes During the Transitional Period from Late Foetal to Early Neonatal Life

1969 ◽  
Vol 4 (2) ◽  
pp. 381-395
Author(s):  
M. B. BISCHOFF ◽  
W. R. RICHTER ◽  
R. J. STEIN
Keyword(s):  
Endoplasmic Reticulum ◽  
Microscopic Study ◽  
Golgi Complex ◽  
Structural Changes ◽  
Bile Canaliculus ◽  
Transitional Period ◽  
Ultrastructural Changes ◽  
Synthetic Activity ◽  
Electron Microscopic ◽  
Neonatal Life

A light-and electron-microscopic study of pig hepatocytes from late prenatal to early neonatal animals shows changes which reflect an increasing rate of synthetic activity. The granular endoplasmic reticulum (ER) in the prenatal pig hepatocyte is situated along the periphery of the cytoplasm and in the region immediately surrounding the nucleus. Mitochondria are most abundant in the area adjacent to the nucleus, while the Golgi complex is generally located in the region of the bile canaliculus. The remaining portion of the hepatocyte is occupied with glycogen. A few hours after birth the hepatocyte increases about twofold in size with the nucleus shifting from a peripheral to a more centrally located position. The glycogen decreases quickly coincident with a rapid increase in the amount of granular ER and the dispersion of the mitochondria throughout the cell. The Golgi complex becomes distended and numerous vesicles appear in its immediate vicinity containing a moderately dense material. Numerous peribiliary inclusions appear during the second postnatal day. These structural changes are an indication of the increased synthetic activity occurring within the hepatocytes of rapidly developing animals.

scholarly journals Induction of Aggregation of Human Blood Platelets by Ultraviolet Light: Action Spectrum and Structural Changes

Blood ◽  
1973 ◽  
Vol 42 (4) ◽  
pp. 551-555 ◽  
Author(s):  
J. C. G. Doery ◽  
R. C. Dickson ◽  
J. Hirsh
Keyword(s):  
Platelet Aggregation ◽  
Ultraviolet Light ◽  
Human Blood ◽  
Structural Changes ◽  
Blood Platelets ◽  
Action Spectrum ◽  
Human Platelets ◽  
Ultrastructural Changes ◽  
Maximal Response ◽  
Human Blood Platelets

Abstract Exposure of washed human platelets to ultraviolet light is followed by platelet aggregation. The effect occurs at wavelengths between 302 and 225 mµ with a maximal response at 248 mµ, and the effect is greatly enhanced by the addition of fibrinogen. Platelets exposed to ultraviolet light show ultrastructural changes which can be induced independently of aggregation if the addition of fibrinogen is omitted.

scholarly journals The effect of hyperhomocysteinemia on the patterns of electron microscopic changes in the liver of adult rats

2020 ◽  
pp. 16-21
Author(s):  
Yu. V. Halahan ◽  
O. Ye. Maievskyi ◽  
Yu. Yo. Guminskyi ◽  
A. P. Korol
Keyword(s):  
Structural Changes ◽  
Significant Proportion ◽  
Male Rats ◽  
Ultrastructural Changes ◽  
Control Group ◽  
Electron Microscopic ◽  
Adult Rats ◽  
Ito Cells ◽  
Young Rats ◽  
Experimental Group

One of the important tasks of modern science is to find biochemical markers that would be able to reflect the risks of development and the nature of the course of various diseases, as well as to predict their possible consequences. In recent years, a significant number of compounds that can affect the biochemical profile of the organism have been identified. Homocysteine – a product of methionine metabolism, belongs to one of these markers, and the effects of its influece on the structure and function of various organs are being actively studied by modern researchers. The aim of the study is to find the patterns of electron microscopic changes in the liver structure of adult rats with hyperhomocysteinemia. The experimental study was performed on 22 white nonlinear mature male rats, which were divided into a control group and an experimental group. A model of persistent hyperhomocysteinemia was created by administering to rats of experimental group thiolactone homocysteine at a dose of 200 mg/kg body weight intragastrically for 60 days. The study of ultrastructural changes in the liver of rats was performed using an electron microscope PEM-125K. In adult rats with experimental hyperhomocysteinemia at the ultrastructural level, dystrophic and destructive changes in hepatocytes, endotheliocytes in the walls of sinusoids and Kupffer cells were found. These changes were more pronounced than in young rats with experimental hyperhomocysteinemia. Revealed structural changes in decompensation (depletion) of mitochondria – fewer number of cristae and enlightened matrix. In contrast to young rats, adult rats with hyperhomocysteinemia in the perisinusoidal spaces showed elongated Ito cells, a significant proportion of the cytoplasm is occupied by the Golgi complex and granular endoplasmic reticulum tanks, indicating protein synthesis for export. In Ito cells, the content of fat droplets, which are located on opposite poles of cells, is reduced. This morphological picture manifests the transformation of Ito cells into fibroblasts.

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.

Ultrastructural Changes in Three Different Mammalian Cells Following Ultraviolet Laser Irradiation

1972 ◽  
Vol 30 ◽  
pp. 350-351
Author(s):  
K. Shankar Narayan ◽  
Kailash C. Gupta ◽  
Tohru Okigaki
Keyword(s):  
Ultraviolet Light ◽  
Mammalian Cells ◽  
Biological Effects ◽  
Survival Rates ◽  
Chinese Hamster ◽  
Cell Types ◽  
Differential Sensitivity ◽  
Ultrastructural Changes ◽  
Ultraviolet Laser

The biological effects of short-wave ultraviolet light has generally been described in terms of changes in cell growth or survival rates and production of chromosomal aberrations. Ultrastructural changes following exposure of cells to ultraviolet light, particularly at 265 nm, have not been reported.We have developed a means of irradiating populations of cells grown in vitro to a monochromatic ultraviolet laser beam at a wavelength of 265 nm based on the method of Johnson. The cell types studies were: i) WI-38, a human diploid fibroblast; ii) CMP, a human adenocarcinoma cell line; and iii) Don C-II, a Chinese hamster fibroblast cell strain. The cells were exposed either in situ or in suspension to the ultraviolet laser (UVL) beam. Irradiated cell populations were studied either "immediately" or following growth for 1-8 days after irradiation.Differential sensitivity, as measured by survival rates were observed in the three cell types studied. Pattern of ultrastructural changes were also different in the three cell types.

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.

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