Fine structure of Egyptian buffalo oocytes (Bubalus bubalis) during different in vitro maturation periods using transmission electron microscopy (TEM)

2012 ◽  
Vol 11 (51) ◽  
Author(s):  
I. A. H. Barakat
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Fine Structure ◽  
In Vitro Maturation ◽  
Bubalus Bubalis ◽  
Transmission Electron ◽  
Egyptian Buffalo

Two- or three-way observations of the identical cell elements within the same sections by LM, TEM and/or SEM

1978 ◽  
Vol 36 (2) ◽  
pp. 82-83 ◽  
Author(s):  
Nakazo Watari ◽  
Yasuaki Hotta ◽  
Yoshio Mabuchi
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Fine Structure ◽  
Light Microscopy ◽  
Thin Sections ◽  
Transmission Electron ◽  
Identical Cell ◽  
Electron Microscopes ◽  
Scanning Electron

It is very useful if we can observe the identical cell elements within the same sections by light microscopy (LM), transmission electron microscopy (TEM) and/or scanning electron microscopy (SEM) sequentially, because, the cell fine structure can not be indicated by LM, while the color is; on the other hand, the cell fine structure can be very easily observed by EM, although its color properties may not. However, there is one problem in that LM requires thick sections of over 1 μm, while EM needs very thin sections of under 100 nm. Recently, we have developed a new method to observe the same cell elements within the same plastic sections using both light and transmission (conventional or high-voltage) electron microscopes.In this paper, we have developed two new observation methods for the identical cell elements within the same sections, both plastic-embedded and paraffin-embedded, using light microscopy, transmission electron microscopy and/or scanning electron microscopy (Fig. 1).

Maytansine-Induced Mitotic Arrest in Human Lymphoblasts

1977 ◽  
Vol 35 ◽  
pp. 460-461
Author(s):  
Tai-Te Chao ◽  
John Sullivan ◽  
Awtar Krishan
Keyword(s):  
Electron Microscopy ◽  
Cell Cycle ◽  
Transmission Electron Microscopy ◽  
Tubulin Polymerization ◽  
Vinca Alkaloids ◽  
Antimitotic Activity ◽  
Transmission Electron ◽  
Flow Microfluorometry ◽  
Brain Tubulin

Maytansine, a novel ansa macrolide (1), has potent anti-tumor and antimitotic activity (2, 3). It blocks cell cycle traverse in mitosis with resultant accumulation of metaphase cells (4). Inhibition of brain tubulin polymerization in vitro by maytansine has also been reported (3). The C-mitotic effect of this drug is similar to that of the well known Vinca- alkaloids, vinblastine and vincristine. This study was carried out to examine the effects of maytansine on the cell cycle traverse and the fine struc- I ture of human lymphoblasts.Log-phase cultures of CCRF-CEM human lymphoblasts were exposed to maytansine concentrations from 10-6 M to 10-10 M for 18 hrs. Aliquots of cells were removed for cell cycle analysis by flow microfluorometry (FMF) (5) and also processed for transmission electron microscopy (TEM). FMF analysis of cells treated with 10-8 M maytansine showed a reduction in the number of G1 cells and a corresponding build-up of cells with G2/M DNA content.

Fine structure and possible functions of the hermaphrodite duct of some pulmonate snails (Mollusca: Gastropoda)

1990 ◽  
Vol 48 (3) ◽  
pp. 68-69
Author(s):  
Alan N. Hodgson
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Fine Structure ◽  
Seminal Vesicle ◽  
Reproductive Biology ◽  
Light Microscope ◽  
Light Microscope Level ◽  
Transmission Electron ◽  
Standard Techniques

The hermaphrodite duct of pulmonate snails connects the ovotestis to the fertilization pouch. The duct is typically divided into three zones; aproximal duct which leaves the ovotestis, the middle duct (seminal vesicle) and the distal ovotestis duct. The seminal vesicle forms the major portion of the duct and is thought to store sperm prior to copulation. In addition the duct may also play a role in sperm maturation and degredation. Although the structure of the seminal vesicle has been described for a number of snails at the light microscope level there appear to be only two descriptions of the ultrastructure of this tissue. Clearly if the role of the hermaphrodite duct in the reproductive biology of pulmonatesis to be understood, knowledge of its fine structure is required.Hermaphrodite ducts, both containing and lacking sperm, of species of the terrestrial pulmonate genera Sphincterochila, Levantina, and Helix and the marine pulmonate genus Siphonaria were prepared for transmission electron microscopy by standard techniques.

scholarly journals Ethosomes and Transethosomes for Mangiferin Transdermal Delivery

Antioxidants ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 768
Author(s):  
Maddalena Sguizzato ◽  
Francesca Ferrara ◽  
Supandeep Singh Hallan ◽  
Anna Baldisserotto ◽  
Markus Drechsler ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Radical Scavenging ◽  
Human Keratinocytes ◽  
Antioxidant Response ◽  
Correlation Spectroscopy ◽  
Inflammatory Status ◽  
Transmission Electron ◽  
Anti Inflammatory

Mangiferin is a natural glucosyl xanthone with antioxidant and anti-inflammatory activity, making it suitable for protection against cutaneous diseases. In this study ethosomes and transethosomes were designed as topical delivery systems for mangiferin. A preformulation study was conducted using different surfactants in association with phosphatidylcholine. Vesicle dimensional distribution was monitored by photon correlation spectroscopy, while antioxidant capacity and cytotoxicity were respectively assessed by free radical scavenging analysis and MTT on HaCaT keratinocytes. Selected nanosystems were further investigated by cryogenic transmission electron microscopy, while mangiferin entrapment capacity was evaluated by ultracentrifugation and HPLC. The diffusion kinetics of mangiferin from ethosomes and transethosomes evaluated by Franz cell was faster in the case of transethosomes. The suitability of mangiferin-containing nanovesicles in the treatment of skin disorders related to pollutants was investigated, evaluating, in vitro, the antioxidant and anti-inflammatory effect of ethosomes and transethosomes on human keratinocytes exposed to cigarette smoke as an oxidative and inflammatory challenger. The ability to induce an antioxidant response (HO-1) and anti-inflammatory status (IL-6 and NF-kB) was determined by RT-PCR and immunofluorescence. The data demonstrated the effectiveness of mangiferin loaded in nanosystems to protect cells from damage. Finally, to gain insight into the keratinocytes’ uptake of ethosome and transethosome, transmission electron microscopy analyses were conducted, showing that both nanosystems were able to pass intact within the cells.

scholarly journals Human Islet Amyloid Polypeptide Fibril Binding to Catalase: A Transmission Electron Microscopy and Microplate Study

2010 ◽  
Vol 10 ◽  
pp. 879-893 ◽  
Author(s):  
Nathaniel G. N. Milton ◽  
J. Robin Harris
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Islet Amyloid Polypeptide ◽  
Amyloid Β ◽  
Human Islet ◽  
Islet Amyloid ◽  
Human Islet Amyloid Polypeptide ◽  
Transmission Electron

The diabetes-associated human islet amyloid polypeptide (IAPP) is a 37-amino-acid peptide that forms fibrilsin vitroandin vivo. Human IAPP fibrils are toxic in a similar manner to Alzheimer's amyloid-β (Aβ) and prion protein (PrP) fibrils. Previous studies have shown that catalase binds to Aβ fibrils and appears to recognize a region containing the Gly-Ala-Ile-Ile sequence that is similar to the Gly-Ala-Ile-Leu sequence found in human IAPP residues 24-27. This study presents a transmission electron microscopy (TEM)—based analysis of fibril formation and the binding of human erythrocyte catalase to IAPP fibrils. The results show that human IAPP 1-37, 8-37, and 20-29 peptides form fibrils with diverse and polymorphic structures. All three forms of IAPP bound catalase, and complexes of IAPP 1-37 or 8-37 with catalase were identified by immunoassay. The binding of biotinylated IAPP to catalase was high affinity with a KDof 0.77nM, and could be inhibited by either human or rat IAPP 1-37 and 8-37 forms. Fibrils formed by the PrP 118-135 peptide with a Gly-Ala-Val-Val sequence also bound catalase. These results suggest that catalase recognizes a Gly-Ala-Ile-Leu—like sequence in amyloid fibril-forming peptides. For IAPP 1-37 and 8-37, the catalase binding was primarily directed towards fibrillar rather than ribbon-like structures, suggesting differences in the accessibility of the human IAPP 24-27 Gly-Ala-Ile-Leu region. This suggests that catalase may be able to discriminate between different structural forms of IAPP fibrils. The ability of catalase to bind IAPP, Aβ, and PrP fibrils demonstrates the presence of similar accessible structural motifs that may be targets for antiamyloid therapeutic development.

Dipetalonema viteae: ultrastructural study on the in vitro interaction between rat macrophages and microfilariae in the presence of IgE antibody

Parasitology ◽  
1981 ◽  
Vol 82 (1) ◽  
pp. 55-62 ◽  
Author(s):  
M. A. Ouaissi ◽  
A. Haque ◽  
A. Capron
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Ultrastructural Study ◽  
Peritoneal Macrophages ◽  
Immune Serum ◽  
Sequence Of Events ◽  
Transmission Electron ◽  
Dipetalonema Viteae ◽  
In Vitro Interaction

SUMMARYThe in vitro interaction between rat peritoneal macrophages and Dipetalonema viteae microfilariae in the presence of amicrofilaraemic rat immune serum was studied by transmission electron microscopy. The probable sequence of events leading to the killing of D. viteae microfilaria by macrophages is as follows. (a) Rat peritoneal macrophages in the presence of amicrofilaraemic rat immune serum adhere to the parasite surface, (b) the macrophages extend their pseudopodia around the parasite, (c) the ‘lysosome-like’ granules discharge their contents on to the parasite surface, (d) the lytic activity of these products begins at the parasite surface and (e) subsequent breaking of the microfilarial cuticle occurs, exposing the parasite intracellular material.

Direct Observation of Fine Structure within Images of Atoms in Crystals by Transmission Electron Microscopy

1977 ◽  
Vol 42 (3) ◽  
pp. 1073-1074 ◽  
Author(s):  
Hatsujiro Hashimoto ◽  
Hisamitsu Endoh ◽  
Takayoshi Tanji ◽  
Akishige Ono ◽  
Eiichi Watanabe
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Fine Structure ◽  
Direct Observation ◽  
Transmission Electron

scholarly journals Optimization of Innovative Three-Dimensionally-Structured Hybrid Vesicles to Improve the Cutaneous Delivery of Clotrimazole for the Treatment of Topical Candidiasis

Pharmaceutics ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 263 ◽  
Author(s):  
Maria Letizia Manca ◽  
Iris Usach ◽  
José Esteban Peris ◽  
Antonella Ibba ◽  
Germano Orrù ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Chemical Properties ◽  
Chemical Characterization ◽  
Yeast Cells ◽  
Unilamellar Vesicles ◽  
Transmission Electron ◽  
Physico Chemical

New three-dimensionally-structured hybrid phospholipid vesicles, able to load clotrimazole in a high amount (10 mg/mL), were obtained for the first time in this work by significantly reducing the amount of water (≤10%), which was replaced with a mixture of glycerol and ethanol (≈90%). A pre-formulation study was carried out to evaluate the effect of both the composition of the hydrating medium and the concentration of the phospholipid on the physico-chemical properties of hybrid vesicles. Four different three-dimensionally-structured hybrid vesicles were selected as ideal systems for the topical application of clotrimazole. An extensive physico-chemical characterization performed using transmission electron microscopy (TEM), cryogenic transmission electron microscopy (cryo-TEM), 31P-NMR, and small-angle X-ray scattering (SAXS) displayed the formation of small, multi-, and unilamellar vesicles very close to each other, and was capable of forming a three-dimensional network, which stabilized the dispersion. Additionally, the dilution of the dispersion with water reduced the interactions between vesicles, leading to the formation of single unilamellar vesicles. The evaluation of the in vitro percutaneous delivery of clotrimazole showed an improved drug deposition in the skin strata provided by the three-dimensionally-structured vesicles with respect to the commercial cream (Canesten®) used as a reference. Hybrid vesicles were highly biocompatible and showed a significant antifungal activity in vitro, greater than the commercial cream Canesten®. The antimycotic efficacy of formulations was confirmed by the reduced proliferation of the yeast cells at the site of infection in vivo. In light of these results, clotrimazole-loaded, three-dimensionally-structured hybrid vesicles appear to be one of the most innovative and promising formulations for the treatment of candidiasis infections.

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