Ultrastructure of ovarian germ cells in the ostrich (Struthio camelus) embryo

2019 ◽  
Vol 22 (3) ◽  
pp. 266-274
Author(s):  
M. Kheirabadi ◽  
A. Nabipour ◽  
H. Dehghani ◽  
M. Behnam-Rasuli
Keyword(s):  
Electron Microscopy ◽  
Germ Cells ◽  
Intercellular Space ◽  
Morphological Characteristics ◽  
Struthio Camelus ◽  
Large Size ◽  
Transmission Electron ◽  
Structural Differences ◽  
Nuclear Organisation ◽  
Ostrich Embryo

In this study, the ultrastructural development of germ cells in the ostrich embryo was analysed. The nuclear organisation and morphological characteristics of cytoplasm in the developing germ cells, on embryonic days 20, 26, and 36 and the day of hatching (5 samples from each stage) was analysed using transmission electron microscopy (TEM). Germ cells located in the cortex of left ovaries were identified by their large size and centrally located nucleus, with a conspicuous nucleolus. In these cells, the cytoplasm contained an abundance of mitochondria and free ribosomes. The structure of Balbiani body, a villous-like elevation in wide intercellular space and desmosome junction between two adjacent germ cells was also studied. The germ cells during embryonic development showed structural differences in both the nucleus and cytoplasm.

Comparative morpho-anatomical studies of the female gonoduct within the Pratylenchidae (Nematoda: Tylenchina)

Nematology ◽  
2003 ◽  
Vol 5 (2) ◽  
pp. 293-306 ◽  
Author(s):  
Gaëtan Borgonie ◽  
Wim Bert ◽  
Ruben Van Gansbeke ◽  
Etienne Geraert ◽  
Myriam Claeys
Keyword(s):  
Electron Microscopy ◽  
Germ Cells ◽  
The Other ◽  
Radopholus Similis ◽  
Cell Extension ◽  
Anatomical Studies ◽  
Transmission Electron ◽  
Wall Cell ◽  
Ovarian Wall ◽  
Nacobbus Aberrans

AbstractThe cellular morphology of the gonoduct of six Pratylenchus species, three Pratylenchoides species, Radopholus similis, Zygotylenchus guevarai, Hirschmanniella loofi and Nacobbus aberrans was revealed by dissection and light microscopy. Except for Nacobbus aberrans, all studied species show an overall similarity in gonoduct construction, i.e., an ovary often ending with a ring of cells, an oviduct formed from two rows of four cells and a 12-celled spermatheca followed by a tricolumella containing 16-24 cells. Pratylenchoides magnicauda and Z. guevarai did not diverge from the other Pratylenchidae in this respect, although their gonoduct differs from that of Amplimerlinius and Meloidogyne, both formerly postulated as related genera. The spermatheca structure observed in N. aberrans has not been reported elsewhere in the Nematoda, although the uterus is similar to that reported within the Heteroderinae and Meloidogyninae and the uterus comprises more than 300 cells, enlarging from a tricolumella to a polycolumella. Transmission electron microscopy of Z. guevarai revealed details of the cytoplasmatic contact between epithelial cells and the germ cells; a finger-like ovarian wall cell extension was found penetrating the oocyte. The oviduct lacks a preformed lumen and comprises eight cells with highly plicated cell membranes. The spermatheca is constructed from flattened wall cells and is followed by columnar uterus cells where evidence of eggshell formation was demonstrated.

CLINICAL AND MORPHOLOGICAL CHARACTERISTICS OF CHRONIC RECURRENT HEMATOGENOUS OSTEOMYELITIS

2020 ◽  
Vol 93 (1) ◽  
pp. 93-99
Author(s):  
Azamat Shamsiev ◽  
◽  
Sukhrob Zainiev ◽  
N. Alieva
Keyword(s):  
Electron Microscopy ◽  
Microbial Contamination ◽  
Morphological Characteristics ◽  
Medullary Canal ◽  
Pathological Changes ◽  
Morphological Studies ◽  
Hematogenous Osteomyelitis ◽  
Transmission Electron ◽  
Bone Fragments ◽  
Tubular Bones

The studied material of scanning and transmission electron microscopy were bone fragments of 40 patients obtained during surgery from various pathologically altered sections of the affected tubular bones. Morphological studies revealed microscopic foci of necrosis, leukocyte infiltrates and microabscesses both in the main focus and in other parts of the bone marrow canal. Microabscesses detected by microscopy represent the morphological basis of chronic hematogenous osteomyelitis, can be located at a considerable distance from the main necrotic purulent focus and, under appropriate conditions, cause a relapse of the disease. Morphological studies have shown that surgical debridement of the lesion with ultrasonic cavitation of the lesion and the medullary canal contributes to a significant reduction in the degree of microbial contamination, followed by a decrease in pathological changes in bone tissue.

Yolk platelet degradation in preemergence Artemia embryos: response to protons in vivo and in vitro

1987 ◽  
Vol 252 (4) ◽  
pp. R774-R781 ◽  
Author(s):  
P. J. Utterback ◽  
S. C. Hand
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Dry Weight ◽  
Platelet Protein ◽  
Transmission Electron ◽  
Structural Differences ◽  
Alkaline Conditions ◽  
Yolk Platelet

Alteration of intracellular pH (pHi) influences yolk platelet degradation during preemergence development in Artemia embryos. Cysts incubated for 10 h under conditions of aerobic development (aqueous medium equilibrated with 60% N2-40% O2, pHi greater than or equal to 7.9) exhibit a significant decrease in numbers of yolk platelets and platelet protein. In contrast, cysts incubated for 10 h under aerobic acidosis (60% CO2-40% O2, pHi = 6.8) show no significant decrease in numbers of yolk platelets or platelet protein. When subjected to alkaline conditions in vitro, yolk platelets release protein exponentially as a function of time. The process is essentially complete in 40 min. The extent of protein and lipid release from platelets increases markedly as pH of the medium is raised in increments from 6.3 to 8.0. Concomitant with these changes are reduction (50%) in platelet dry weight and reduction (21%) in platelet diameter. Transmission electron microscopy does not reveal major structural differences between isolated yolk platelets and those contained in hydrated embryos. The proton effects on platelet composition and size detected in vitro may explain in part the mechanism of platelet degradation observed during aerobic development and its suppression under conditions of acidic pHi.

scholarly journals Bisphosphonate’s Effect on Tongue Mucosa: An Experimental Electron Microscopy Study

Medicina ◽  
2020 ◽  
Vol 56 (2) ◽  
pp. 51
Author(s):  
Theodora Papamitsou ◽  
Antonios Morsi-Yeroyannis ◽  
Anastasios Papanastasiou ◽  
Nikolaos Bakalopoulos ◽  
Eva-Maria Dietrich ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Intercellular Space ◽  
Wistar Rats ◽  
Middle Layer ◽  
Microscopy Study ◽  
Electron Microscopy Study ◽  
Control Group ◽  
The Past ◽  
Transmission Electron ◽  
Experimental Group

Background and objectives: Bisphosphonates (BPs) are selective inhibitors of osteoclasts, used for the treatment of bone disorders. The objective of this study is to investigate the possible effects of BPs on the tongue’s mucosa. Materials and Methods: Specimens of the tongue of 20 female 12-month old Wistar rats were taken. Ten were used as control group, while in the remaining alendronate (Fosamax, Merck) was administered per os from 13 weeks. Observation of the harvested samples was made by Transmission Electron Microscopy (TEM). Results: In the experimental group, focal alterations were observed to various extent in all specimens. The basement membrane was intact. Furthermore, an increase at the intercellular space was observed, predominantly at the middle layer, and the desmosomes were disorganized. In the lamina propria focal edema was observed. Conclusions: Investigation on the effect of BPs on the tongue’s mucosa through TEM hasn’t been documented in the past. According to our results, BPs seem to cause mild mucosal lesions on the tongue.

Effect of Additive Constraint on the Morphological and Mechanical Properties of Triblock Copolymer Blends

1996 ◽  
Vol 461 ◽  
Author(s):  
L. Kane ◽  
D. A. Norman ◽  
S. A. White ◽  
R. J. Spontak
Keyword(s):  
Electron Microscopy ◽  
Diblock Copolymer ◽  
Triblock Copolymer ◽  
Morphological Characteristics ◽  
Mechanical Analysis ◽  
Molecular Weights ◽  
Copolymer Blends ◽  
Transmission Electron ◽  
Copolymer Blend

ABSTRACTWhile numerous studies have addressed the morphological characteristics of diblock copolymer blends either with a second copolymer or a parent homopolymer, relatively few have examined comparable blends containing a triblock copolymer. In this study, we investigate the role of mid-block bridging on the morphological and physical characteristics of blends composed of a poly(styrene-b-isoprene-b-styrene) (SIS) triblock copolymer with either an unconstrained homo-polyisoprene (hI) or an end-grafted SI diblock copolymer. Blend compositions and molecular weights of the hi, as well as the I-block of the copolymer, have all been systematically varied to elucidate the effect of additive constraint on the extent of nonideal intramicrodomain mixing. Blend morphologies are characterized using transmission electron microscopy, while blend properties have been measured by dynamic mechanical analysis.

Isolation and Ultrastructure of Aleurone Cell Walls From Wheat and Barley

1981 ◽  
Vol 8 (5) ◽  
pp. 453 ◽  
Author(s):  
A Bacic ◽  
BA Stone
Keyword(s):  
Electron Microscopy ◽  
Cell Walls ◽  
Morphological Characteristics ◽  
Triticum Aestivum L ◽  
Whole Grains ◽  
Starchy Endosperm ◽  
Hordeum Vulgare L ◽  
Air Classification ◽  
Transmission Electron ◽  
Bilayered Structure

Aleurone layers and cell walls from both wheat (Triticum aestivum L. cv. Insignia) and barley (Hordeum vulgare L. cv. Clipper) have been isoIated by differential centrifugation in benzene-carbon tetrachloride mixtures and by air classification. The isolated walls were obtained in sufficient quantities and purity for comprehensive chemical analysis. Morphological characteristics of the isolated aleurone layers and walls were examined by bright field, fluorescence and scanning electron microscopy and compared with their appearance in whole grains. Transmission electron microscopy of wall sections clearly showed their characteristic bilayered structure. Aniline blue-positive deposits were observed at the aleurone-starchy endosperm interfaces of both wheat and barley.

scholarly journals Manganese ferrite graphene nanocomposite synthesis and the investigation of its antibacterial properties for water treatment purposes

2020 ◽  
Vol 15 (4) ◽  
pp. 1
Author(s):  
Lara De Souza Soletti ◽  
Maria Eliana Camargo Ferreira ◽  
Alex Toshio Kassada ◽  
Benício Alves de Abreu Filho ◽  
Rosangela Bergamasco ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Antibacterial Activity ◽  
Water Treatment ◽  
Graphene Nanosheets ◽  
Antibacterial Properties ◽  
Morphological Characteristics ◽  
Manganese Ferrite ◽  
Transmission Electron ◽  
Cutting Effect ◽  
Mnfe2o4 Nanoparticles

The main objective of this study was to synthesize a nanocomposite using graphene and manganese ferrite nanoparticles (MnFe2O4-G) and to evaluate its antibacterial activity for water treatment purposes. Its morphological characteristics were evaluated by instrumental techniques, such as scanning electron microscopy and transmission electron microscopy. The characterization results indicated that the nanocomposite presented nanoparticles of approximately 25 nm well dispersed in transparent and large (14 μm) graphene nanosheets. The antibacterial activity was evaluated in a batch experiment using a concentration of 40 μg mL-1 of nanocomposite (MnFe2O4-G, bare MnFe2O4 nanoparticles or graphene oxide), 1x105 CFU mL-1 of Escherichia coli, and 8 h of contact time at room temperature. The highest antibacterial capacity was observed for the hybrid nanocomposite (91.91%), due to the synergic effect of graphene and MnFe2O4 nanoparticles. Various mechanisms were proposed to explain the effective antibacterial activity of MnFe2O4-G, such as wrapping, oxidative stress, sharp-edge cutting effect, among others. The results showed that MnFe2O4-G is a potential alternative in water treatment processes as an antibacterial agent.

scholarly journals Morphological aspects of cell reabsorption in laying queens and workers of Apis mellifera (Hymenoptera, Apidae)

2008 ◽  
Vol 98 (4) ◽  
pp. 421-424 ◽  
Author(s):  
Karina Patrício ◽  
Carminda da Cruz-Landim
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Apis Mellifera ◽  
Environmental Factors ◽  
Developmental Stage ◽  
Oocyte Maturation ◽  
Morphological Characteristics ◽  
Follicular Cells ◽  
Morphological Aspects ◽  
Transmission Electron

The occurrence of cell reabsorption in the ovaries of queens in several rates of laying eggs, artificially impeded of laying, and in nurse workers, of Apis mellifera (Linnaeus, 1758), was studied with light (LM) and transmission electron microscopy (TEM). Two types of structures were described and named by analogy with vertebrates ovarian structures, as corpus luteus, when resulting from the reabsorption of the follicular cells after ovulation, and corpus atresicus when resulting from total follicular reabsorption at any oocyte developmental stage. These structures have the same morphological characteristics and physiological signification in both castes. The corpus luteus occurrence indicates ovulation and its number is correspondent to the queen's rates of oviposition. The presence of this structure in nurse workers ovarioles shows that this caste may lay eggs. The incidence of corpus atresicus in queens decay with the increasing of the oviposition indicating that the inhibition of the normal sequence of oocyte maturation in the ovaries is deleterious. Both, corpus luteus and corpus atresicus incidence may be influenced by environmental factors.

A Correlated Scanning And Transmission Electron Microscopy Study of Pulmonary Airway Morphology in the Rhesus Monkey

1973 ◽  
Vol 31 ◽  
pp. 618-619
Author(s):  
W. L. Castleman ◽  
D. L. Dungworth
Keyword(s):  
Electron Microscopy ◽  
Rhesus Monkeys ◽  
Experimental Studies ◽  
Microscopy Study ◽  
Electron Microscopy Study ◽  
Transmission Electron ◽  
Critical Point Drying ◽  
Pulmonary Airways ◽  
Structural Differences ◽  
Airway Morphology

Previous research has indicated that there are important differences in the structure of pulmonary airways among various species of mammals and that these structural differences must be taken into consideration when animal models are being used in experimental studies of pulmonary disease. An investigation is being undertaken in this laboratory to characterize airway structure in several species of nonhuman primates and compare that structure with airway structure that has been described in man. The following is a report on studies of lungs from rhesus monkeys.Lungs from adult rhesus monkeys were, fixed via the airways with cacodylatebuffered glutaraldehyde-formaldehyde. Various levels of bronchi and bronchioles were bisected with razor blades. One half of the bisected airway was prepared for scanning electron microscopy by dehydration, critical point drying from CO2, and conductive coating with silver and gold.

scholarly journals Morphological characteristics and cell viability of coffee plants calli

2014 ◽  
Vol 44 (4) ◽  
pp. 660-665 ◽  
Author(s):  
Marlúcia Souza Pádua ◽  
Luciano Vilela Paiva ◽  
Luciano Coutinho da Silva ◽  
Kalynka Gabriella do Livramento ◽  
Eduardo Alves ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Cell Viability ◽  
Coffea Arabica ◽  
Morphological Characteristics ◽  
Leaf Explants ◽  
Transmission Electron ◽  
Different Types ◽  
Coffee Plants ◽  
Cytoplasm Vacuolization

The aim of this research was to characterize and compare two types of calli from leaf explants of Coffea arabica (cultivar Catiguá). Cells of different types of callus were successfully characterized regarding viability and internal and external morphological characteristics. It was obtained two morphologically distinct types of callus: (i) yellow friable and (ii) transparent watery. The yellow friable calli showed higher cell viability and embryogenic characteristics. Scanning and transmission electron microscopy showed embryogenic characteristics in cells of the yellow friable calli evidenced by the presence of small and isodiametric cells, while transparent watery calli showed elongated cells and large cytoplasm vacuolization.

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