Histological Studies on the Genus Fucus

1968 ◽  
Vol 3 (1) ◽  
pp. 1-16
Author(s):  
MARGARET E. MCCULLY
Keyword(s):  
Inorganic Carbon ◽  
Alginic Acid ◽  
Light And Electron Microscopy ◽  
Epidermal Cells ◽  
Membrane Interface ◽  
Histological Studies ◽  
Basal Nuclei ◽  
Golgi System ◽  
Intracellular Volume

The fine structure of the epidermal cells of the vegetative Fucus thallus has been examined in material fixed with acrolein. These cells are highly polarized, with basal nuclei and chloroplasts, a hypertrophied perinuclear Golgi system, and a much convoluted wall/plasma membrane interface. Much of the intracellular volume is occupied by single membrane-bounded vesicles containing alginic acid, fucoidin and polyphenols. The chloroplasts were examined by light and electron microscopy and shown to contain structured inclusions not previously described in Fucus plastids. It is suggested on the basis of their morphology that the epidermal cells may be specialized for the absorption of inorganic carbon and sulphate from the outside of the plant and for the secretion of alginic acid, fucoidin and polyphenols. The possible role of these cells in the prevention of desiccation and in osmoregulation is discussed.

The Role of Mitochondria in the Genesis of Neuroaxonal Dystrophy in the Brains of Aging Mice

1975 ◽  
Vol 33 ◽  
pp. 372-373
Author(s):  
J.E. Johnson
Keyword(s):  
Electron Microscopy ◽  
Present Report ◽  
Light And Electron Microscopy ◽  
Dorsal Column ◽  
Neuroaxonal Dystrophy ◽  
Nucleus Gracilis ◽  
Dystrophic Axons ◽  
The Brain ◽  
Nucleus Cuneatus

Although neuroaxonal dystrophy (NAD) has been examined by light and electron microscopy for years, the nature of the components in the dystrophic axons is not well understood. The present report examines nucleus gracilis and cuneatus (the dorsal column nuclei) in the brain stem of aging mice.Mice (C57BL/6J) were sacrificed by aldehyde perfusion at ages ranging from 3 months to 23 months. Several brain areas and parts of other organs were processed for electron microscopy.At 3 months of age, very little evidence of NAD can be discerned by light microscopy. At the EM level, a few axons are found to contain dystrophic material. By 23 months of age, the entire nucleus gracilis is filled with dystrophic axons. Much less NAD is seen in nucleus cuneatus by comparison. The most recurrent pattern of NAD is an enlarged profile, in the center of which is a mass of reticulated material (reticulated portion; or RP).

scholarly journals Morphological Alterations and Increased S100B Expression in Epidermal Langerhans Cells Detected in Skin from Patients with Progressive Vitiligo

Life ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 579
Author(s):  
Fei Yang ◽  
Lingli Yang ◽  
Lanting Teng ◽  
Huimin Zhang ◽  
Ichiro Katayama
Keyword(s):  
Electron Microscopy ◽  
Langerhans Cells ◽  
Critical Role ◽  
Light And Electron Microscopy ◽  
Morphological Alterations ◽  
Birbeck Granules ◽  
Immuno Electron Microscopy ◽  
Skin Biopsies ◽  
Epidermal Langerhans Cells

The role of Langerhans cells (LCs) in vitiligo pathogenesis remains unclear, with published studies reporting contradictory results regarding the quantity of LCs and no data on the features of LCs in vitiligo. Here, we aimed to analyze the presence, density, and morphological features of LCs in the epidermis of patients with vitiligo. Skin biopsies were stained for LCs using anti-CD1a/anti-langerin antibodies and analyzed by immunocytochemistry with light and electron microscopy. Compared with healthy controls, we detected significantly increased numbers of epidermal LCs in lesional skin from vitiligo in the progressive state. These LCs exhibited striking morphological alterations, including an elevated number of dendrites, with increased length and more branches than dendrites from controls. Ultrastructure examination via immuno-electron microscopy revealed markedly reduced Birbeck granules (BGs) and shorter BG rods in LCs from progressive vitiligo, with higher expression of langerin. Additionally, expression of S100B, the activity biomarker of vitiligo, was increased in these LCs. This work provides new insight on the cellular composition of LCs in vitiliginous skin, revealing altered morphology and increased LC numbers, with elevated S100B expression. Our data suggest LCs might play a critical role in vitiligo pathogenesis and thus may represent a novel therapeutic target for this disease.

scholarly journals The Role of Catalase-Peroxidase Secreted by Magnaporthe oryzae During Early Infection of Rice Cells

2011 ◽  
Vol 24 (2) ◽  
pp. 163-171 ◽  
Author(s):  
Shigeru Tanabe ◽  
Naoko Ishii-Minami ◽  
Ken-Ichiro Saitoh ◽  
Yuko Otake ◽  
Hanae Kaku ◽  
...  
Keyword(s):  
Culture Filtrate ◽  
Magnaporthe Oryzae ◽  
Early Stage ◽  
Major Gene ◽  
Leaf Sheath ◽  
Epidermal Cells ◽  
Amino Acid Sequences ◽  
Conidial Suspension ◽  
Catalase Peroxidase

The biological role of a secretory catalase of the rice blast fungus Magnaporthe oryzae was studied. The internal amino acid sequences of the partially purified catalase in the culture filtrate enabled us to identify its encoding gene as a catalase-peroxidase gene, CPXB, among four putative genes for catalase or catalase-peroxidase in M. oryzae. Knockout of the gene drastically reduced the level of catalase activity in the culture filtrate and supernatant of conidial suspension (SCS), and increased the sensitivity to exogenously added H2O2 compared with control strains, suggesting that CPXB is the major gene encoding the secretory catalase and confers resistance to H2O2 in hyphae. In the mutant, the rate of appressoria that induced accumulation of H2O2 in epidermal cells of the leaf sheath increased and infection at early stages was delayed; however, the formation of lesions in the leaf blade was not affected compared with the control strain. These phenotypes were complimented by reintroducing the putative coding regions of CPXB driven by a constitutive promoter. These results suggest that CPXB plays a role in fungal defense against H2O2 accumulated in epidermal cells of rice at the early stage of infection but not in pathogenicity of M. oryzae.

Intestinal Lesions Containing Coronavirus-like Particles in Neonatal Necrotizing Enterocolitis: An Ultrastructural Analysis

PEDIATRICS ◽  
1984 ◽  
Vol 73 (2) ◽  
pp. 218-224
Author(s):  
S. Rousset ◽  
O. Moscovici ◽  
P. Lebon ◽  
J. P. Barbet ◽  
P. Helardot ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Small Intestine ◽  
Necrotizing Enterocolitis ◽  
Intestinal Mucosa ◽  
Light And Electron Microscopy ◽  
Anaerobic Bacteria ◽  
Intestinal Lesions ◽  
Maternity Hospitals ◽  
Neonatal Necrotizing Enterocolitis

Since the outbreaks of neonatal necrotizing enterocolitis occurring in maternity hospitals of Paris and suburbs in 1979-1980, it has been possible to examine by light and electron microscopy gut specimens from ten newborns with this illness. Coronavirus-like particles, enclosed in intracytoplasmic vesicles of damaged epithelial cells of the intestinal mucosa, were observed in the small intestine, appendix, and colon. The ultrastructural study, supported by bacteriologic findings, suggests the role of coronavirus-like particles in the appearance of the lesions. Secondary proliferation of mainly anaerobic bacteria, probably responsible for pneumatosis, may aggravate the disease.

scholarly journals Efficacy of Miltefosine and Artemether on infected Biomphalaria alexandrina snails with Schistosoma mansoni: immunological and histological studies

2020 ◽  
Vol 57 (4) ◽  
pp. 335-343
Author(s):  
H. H. Abdel-Azeem ◽  
G. Y. Osman ◽  
M. F. El Garhy ◽  
K. S. Al Benasy
Keyword(s):  
Electron Microscopy ◽  
Schistosoma Mansoni ◽  
Light And Electron Microscopy ◽  
Post Treatment ◽  
Sublethal Dose ◽  
Biomphalaria Alexandrina ◽  
Histological Studies ◽  
Morphological Abnormalities ◽  
Medical Importance

SummaryBiomphalaria alexandrina snails have received much attention due to their great medical importance as vectors for transmitting Schistosoma mansoni infection to humans. The main objective of the present work was to assess the efficacy of miltefosin a synthetic molluscicidal drug and artemether a natural molluscicidal drug. The correlation between immunological and histological observations from light and electron microscopy of the hemocytes of B. alexandrina post treatment with both drugs was also evaluated. LC50 and LC90 values were represented by 13.80 ppm and 24.40 ppm for miltefosine and 16.88 ppm and 27.97 ppm for artemether, respectively. The results showed that the treatment of S. mansoni-infected snails and normal snails with sublethal dose of miltefosine (LC25=8.20 ppm) and artemether (LC25=11.04 ppm) induced morphological abnormalities and a significant reduction in hemocytes count.

scholarly journals Glycogen Phosphorylase in Acanthamoeba spp.: Determining the Role of the Enzyme during the Encystment Process Using RNA Interference

2008 ◽  
Vol 7 (3) ◽  
pp. 509-517 ◽  
Author(s):  
Jacob Lorenzo-Morales ◽  
Jarmila Kliescikova ◽  
Enrique Martinez-Carretero ◽  
Luis Miguel De Pablos ◽  
Bronislava Profotova ◽  
...  
Keyword(s):  
Rna Interference ◽  
Cyst Wall ◽  
Glycogen Phosphorylase ◽  
Catalytic Domain ◽  
Present Report ◽  
Light And Electron Microscopy ◽  
Main Tool ◽  
Lower Eukaryotes ◽  
Free Glucose

ABSTRACT Acanthamoeba infections are difficult to treat due to often late diagnosis and the lack of effective and specific therapeutic agents. The most important reason for unsuccessful therapy seems to be the existence of a double-wall cyst stage that is highly resistant to the available treatments, causing reinfections. The major components of the Acanthamoeba cyst wall are acid-resistant proteins and cellulose. The latter has been reported to be the major component of the inner cyst wall. It has been demonstrated previously that glycogen is the main source of free glucose for the synthesis of cellulose in Acanthamoeba, partly as glycogen levels fall during the encystment process. In other lower eukaryotes (e.g., Dictyostelium discoideum), glycogen phosphorylase has been reported to be the main tool used for glycogen breakdown in order to maintain the free glucose levels during the encystment process. Therefore, it was hypothesized that the regulation of the key processes involved in the Acanthamoeba encystment may be similar to the previously reported regulation mechanisms in other lower eukaryotes. The catalytic domain of the glycogen phosphorylase was silenced using RNA interference methods, and the effect of this phenomenon was assessed by light and electron microscopy analyses, calcofluor staining, expression zymogram assays, and Northern and Western blot analyses of both small interfering RNA-treated and control cells. The present report establishes the role of glycogen phosphorylase during the encystment process of Acanthamoeba. Moreover, the obtained results demonstrate that the enzyme is required for cyst wall assembly, mainly for the formation of the cell wall inner layer.

The Distribution of Glycogen in the Tissues of Siboglinum Atlanticum [Pogonophora]

1973 ◽  
Vol 53 (3) ◽  
pp. 665-671 ◽  
Author(s):  
Eve C. Southward
Keyword(s):  
Electron Microscopy ◽  
Light And Electron Microscopy ◽  
Epidermal Cells ◽  
Peritoneal Cells ◽  
Body Regions ◽  
Three Body

Light and electron microscopy showed the same distribution of glycogen. The peritoneal cells contain large amounts in all three body regions investigated: the forepart, metameric region and postannular region. Glycogen is present in most epidermal cells and is very abundant in some, particularly in the postannular region, but the cells which secrete the chitinous and proteinaceous components of the tube are almost devoid of glycogen.

Colleters in the vegetative axis of Aechmea blanchetiana (Bromeliaceae): anatomical, ultrastructural and functional aspects

2018 ◽  
Vol 66 (5) ◽  
pp. 379 ◽  
Author(s):  
Igor Ballego-Campos ◽  
Elder Antônio Sousa Paiva
Keyword(s):  
Developmental Stages ◽  
Light And Electron Microscopy ◽  
Secretory Activity ◽  
Functional Roles ◽  
Reproductive Axis ◽  
Functional Aspects ◽  
The Family ◽  
Marginal Cells ◽  
First Time

Colleters are common among eudicotyledons, but few records exist for monocotyledons and other groups of plants. For Bromeliaceae, mucilage secretions that protect the young portions of the plant have been observed only in the reproductive axis, and little is known about the secretory systems behind this or even other kind of secretions in the family. We aimed to describe, for the first time, the occurrence of colleters associated with the vegetative shoot of Aechmea blanchetiana (Baker) L.B.Sm., and elucidate aspects of their structure, ultrastructure and secretory activity. Samples of various portions of the stem axis were prepared according to standard methods for light and electron microscopy. Colleters were found compressed in the axillary portion of leaves and in all leaf developmental stages. Secretory activity, however, was found to be restricted to young and unexpanded leaves. The colleters displayed a flattened hand-like shape formed by a multiseriate stalk and an expanded secretory portion bearing elongated marginal cells. Ultrastructural data confirmed that the secretory role of the colleters is consistent with mucilaginous secretion. The functional roles of the colleters are discussed with regard to environmental context and intrinsic features of the plant, such as the presence of a water-impounding tank.

The role of Golgi bodies in polysaccharide sulphation in Fucuszygotes

1978 ◽  
Vol 32 (1) ◽  
pp. 337-356
Author(s):  
M.E. Callow ◽  
S.J. Coughlan ◽  
L.V. Evans
Keyword(s):  
Cell Wall ◽  
Alginic Acid ◽  
Soluble Fraction ◽  
Amorphous Layer ◽  
Acceptor Molecule ◽  
Golgi Bodies ◽  
Isolation And Characterization ◽  
Fucus Serratus

The cell wall of 24-h zygotes of Fucus serratus is composed of 3 layers—an inner fibrillar layer (sulphated fucan), an outer fibrillar layer (alginic aicd/cellulose) and an exterior amorphous layer (sulphated fucan, alginic acid). The 2 layers containing sulphated fucan are preferentially thickened at the rhizoid pole. Light- and electron-microscope autoradiographic pulse-chase experiments on 22-h zygotes using 35SO2-(4) show the Golgi bodies to be the sites of fucan sulphation. The isolation and characterization of isolated Golgi-rich fractions from 22-h zygotes shows that the first detectable labelled macromolecule is associated with these fractions 2 min after addition of 35SO2-(4). The sulphate acceptor molecule has been partially characterized. 35S-APS and 35S-paps are detectable in the soluble fraction 0.5 min after addition of 35SO2-(4). The results are discussed in relation to other published work on the differentiation of Fucus embryos and on polysaccharide sulphation.

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