scholarly journals Estimation, morphometry and ultrastructure of ovarian preantral follicle population in agouti (Dasyprocta leporina)

2018 ◽  
Vol 38 (1) ◽  
pp. 175-182 ◽  
Author(s):  
Erica A.A. Santos ◽  
Gabriela L. Lima ◽  
Erica C.G. Praxedes ◽  
Andréia M. Silva ◽  
Keilla M. Maia ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Ultrastructural Analysis ◽  
Preantral Follicle ◽  
Transmission Electron ◽  
The Mean ◽  
First Time ◽  
Further Development

ABSTRACT: The aim of this study was to characterize the preantral ovarian follicular population in agoutis (D. leporina) by estimating the number of follicles at each developmental category, and also describe the morphometry and the specific features of the follicle and the oocyte by using light and transmission electron microscopy. The length of each ovary was measured using a caliper rule, longitudinally sectioned into two halves and both were immediately fixed to perform the estimation of follicular population and ultrastructural analysis. The mean (±S.E.M.) population of follicular per pair of ovary was estimated at 4419.8±532.26 and 5397.52±574.91 for right and left ovaries, respectively, but no differences were observed between them. The diameters for follicles, oocyte and nuclei were: 18.62±3.40μm, 12.28±2.37μm and 6.10±0.93μm for primordial, 23.75±5.70μm, 14.22±3.00μm and 6.70±1.24μm for primary and 88.55±17.61μm, 52.85±17.56μm and 22.33±17.61μm for secondary follicles, respectively. The most of the follicles found belonged to the primordial category (86.63%), followed by primary (13.01%) and secondary (0.35%) one. Additionally, polyovular follicles were observed in all the animals and they represented 7.51% of the total follicles counted. The ultrastructural analysis showed that the oocyte presented a central and regular nuclei, displaying a homogenous mass. Among the organelles, the mitochondria were the most abundant and the oocyte Golgi apparatus was rarely observed. In conclusion, this work shows for the first time the characterization of the population of preantral follicles in the ovary of Dasyprocta leporina. Those information will be useful for further development and adaptation of biotechniques such as germplasm cryopreservation and in vitro gametes manipulation.

scholarly journals Preparation and characterization of baicalein loaded phytosomes: Assessment of in vitro parameters

2020 ◽  
Vol 12 (4) ◽  
pp. 22-29
Author(s):  
KanchanV Zade ◽  
Alok Pal Jain
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Differential Scanning Calorimetry ◽  
Herbal Extracts ◽  
Scanning Calorimetry ◽  
Reverse Phase ◽  
Tem Analysis ◽  
Transmission Electron

Phytosome is a complex between natural active ingredient and a phospholipid. Further, phytosomes been applied to many popular herbal extracts or active molecules for augmenting oral dissolution. Therefore, in present investigation, orally administered Baicalein, atype of flavanoids, is poorly absorbed, and shows suboptimal dissolution. The phytosomes encapsulating baicalein (1:1 Mm) were prepared by reverse phase evaporation method followed by lyophilization. Transmission electron microscopy (TEM) analysis revealed that phytosomes were almost spherical in shape with particle size below 100 nm. The Powder ex-ray diffraction (PXRD) and differential scanning calorimetry (DSC) demonstrated that Baicalein loaded phytosomes were amorphous in nature. Amorphization of therapeutic moiety leads to improvement in dissolution. In conclusion, epigallocatechin loaded phytosomes exhibited promising results and warrant further in vitro andin vivo investigations under a set of stringent parameters for transforming in to a clinically viable products.

scholarly journals Unraveling the complexity of amyloid polymorphism using gold nanoparticles and cryo-EM

2020 ◽  
Vol 117 (12) ◽  
pp. 6866-6874 ◽  
Author(s):  
Urszula Cendrowska ◽  
Paulo Jacob Silva ◽  
Nadine Ait-Bouziad ◽  
Marie Müller ◽  
Zekiye Pelin Guven ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Gold Nanoparticles ◽  
Amyloid Fibrils ◽  
Imaging Techniques ◽  
Postmortem Brain ◽  
Structural Basis ◽  
Transmission Electron

Increasing evidence suggests that amyloid polymorphism gives rise to different strains of amyloids with distinct toxicities and pathology-spreading properties. Validating this hypothesis is challenging due to a lack of tools and methods that allow for the direct characterization of amyloid polymorphism in hydrated and complex biological samples. Here, we report on the development of 11-mercapto-1-undecanesulfonate-coated gold nanoparticles (NPs) that efficiently label the edges of synthetic, recombinant, and native amyloid fibrils derived from different amyloidogenic proteins. We demonstrate that these NPs represent powerful tools for assessing amyloid morphological polymorphism, using cryogenic transmission electron microscopy (cryo-EM). The NPs allowed for the visualization of morphological features that are not directly observed using standard imaging techniques, including transmission electron microscopy with use of the negative stain or cryo-EM imaging. The use of these NPs to label native paired helical filaments (PHFs) from the postmortem brain of a patient with Alzheimer’s disease, as well as amyloid fibrils extracted from the heart tissue of a patient suffering from systemic amyloid light-chain amyloidosis, revealed a high degree of homogeneity across the fibrils derived from human tissue in comparison with fibrils aggregated in vitro. These findings are consistent with, and strongly support, the emerging view that the physiologic milieu is a key determinant of amyloid fibril strains. Together, these advances should not only facilitate the profiling and characterization of amyloids for structural studies by cryo-EM, but also pave the way to elucidate the structural basis of amyloid strains and toxicity, and possibly the correlation between the pathological and clinical heterogeneity of amyloid diseases.

Electron microscopy characterization of monoclinic SiAs precipitates in heavily As+-implanted silicon

1991 ◽  
Vol 6 (8) ◽  
pp. 1701-1710 ◽  
Author(s):  
A. Armigliato ◽  
A. Parisini
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Annealing Temperature ◽  
X Ray ◽  
Transmission Electron ◽  
Small Precipitate ◽  
Diffraction Patterns ◽  
Microscopy Characterization ◽  
First Time

Silicon wafers have been implanted with As+ ions at an energy of 100 keV and a dose of 1 × 1017 cm−2 and subsequently annealed at 1050°for 15 min. This results in a peak As concentration of 7 × 1021 cm−3, which is far beyond the solid solubility value of arsenic in silicon at this annealing temperature. Rod-like precipitates, dislocations, and small precipitate-like defects have been observed by transmission electron microscopy. From the analysis of several diffraction patterns taken on a number of rod-like particles at different tilt angles, it has been unambiguously found that they have the structure of the monoclinic SiAs compound previously reported in literature. The stoichiometry of the precipitates has been confirmed by x-ray microanalysis. To our knowledge, this is the first time that this SiAs phase is detected in As+-implanted silicon.

scholarly journals Preparation and Characterization of Folate Targeting Magnetic Nanomedicine Loaded with Cisplatin

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Minqiang Xie ◽  
Yiming Xu ◽  
Jie Liu ◽  
Tao Zhang ◽  
Hongzheng Zhang
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Water Solubility ◽  
Folate Receptor ◽  
Drug Loading ◽  
Hydroxyl Group ◽  
Transmission Electron ◽  
Scattering Phase

We used Aldehyde sodium alginate (ASA) as modifier to improve surfactivity and stability of magnetic nanoparticles, and folate acid (FA) as targeting molecule. Fe3O4nanoparticles were prepared by chemical coprecipitation method. FA was activated and coupled with diaminopolyethylene glycol (NH2-PEG-NH2). ASA was combined with Fe3O4nanoparticles, and FA-PEG was connected with ASA by Schiff’s base formation. Then Cl-in cisplatin was replaced by hydroxyl group in ASA, and FA- and ASA-modified cisplatin-loaded magnetic nanomedicine (CDDP-FA-ASA-MNPs) was prepared. This nanomedicine was characterized by transmission electron microscopy, dynamic lighterring scattering, phase analysis light scattering and vibrating sample magnetometer. The uptake of magnetic nanomedicine by nasopharyngeal and laryngeal carcinoma cells with folate receptor positive or negative expression were observed by Prussian blue iron stain and transmission electron microscopy. We found that CDDP-FA-ASA-MNPs have good water-solubility and stability. Mean diameter of Fe3O4core was 8.17 ± 0.24 nm, hydrodynamic diameters was110.90±1.70 nm, and zeta potential was-26.45±1.26 mV. Maximum saturation magnetization was 22.20 emu/g. CDDP encapsulation efficiency was49.05±1.58% (mg/mg), and drug loading property was14.31±0.49% (mg/mg). In vitro, CDDP-FA-ASA-MNPs were selectively taken up by HNE-1 cells and Hep-2 cells, which express folate receptor positively.

Characterisation and cryopreservation of the ovarian preantral follicle population from Spix’s yellow-toothed cavies (Galea spixii Wagler, 1831)

2017 ◽  
Vol 29 (3) ◽  
pp. 594 ◽  
Author(s):  
Érica C. G. Praxedes ◽  
Gabriela L. Lima ◽  
Andréia M. Silva ◽  
Carlos A. C. Apolinário ◽  
José A. B. Bezerra ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Light Microscopy ◽  
Population Analysis ◽  
Ovarian Tissue ◽  
Morphological Aspect ◽  
Preantral Follicle ◽  
Transmission Electron ◽  
The Mean ◽  
The Right

The aim of the present study was to characterise the ovarian preantral follicle (PF) population and to establish a solid surface vitrification (SSV) process using dimethyl sulfoxide (DMSO) as a cryoprotectant for preservation of ovarian tissue from yellow-toothed cavies (Galea spixii). Ovaries were fixed for PF population analysis or were subjected to the SSV process. The mean (± s.e.m.) PF population per ovarian pair was estimated to be 416.0 ± 342.8. There were 140.0 ± 56.0 (63.4%) and 125.0 ± 58.0 (64.0%) primary follicles on the right and left ovaries, respectively. The proportion of this follicle category was significantly greater than that of other follicle categories (P < 0.05). The diameter of follicles (123.7 ± 18.3 µm), oocytes (50.1 ± 5.0 µm) and nuclei (14.27 ± 2.01 µm) was larger for secondary ones when compared with other PFs categories. Most PFs were morphologically normal (94.6%), with light microscopy identifying only a few atretic follicles (5.4%). After SSV, there was a reduction in the proportion of morphologically normal PFs compared with the non-vitrified group (69.5% vs 91.2%, respectively). Transmission electron microscopy revealed preservation of oocytes and granulosa cell membranes and the morphological aspect of follicles; the primary change observed in some vitrified PFs was the presence of vacuoles in the oocytes and granulosa cells cytoplasm and turgid mitochondria. In conclusion, the present study provides an estimative and characterization for the PF population in ovaries of G. spixii. Moreover, we report its PFs cryopreservation using an SSV process.

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.

Characterization of submicrometer fluid Inclusions in minerals by Analytical/Transmission Electron Microscopy and electron diffraction

1990 ◽  
Vol 48 (4) ◽  
pp. 424-424
Author(s):  
George Guthrie ◽  
David Veblen
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Electron Microscope ◽  
Electron Diffraction ◽  
Light Microscopy ◽  
Fluid Inclusions ◽  
Energy Dispersive Spectrometer ◽  
Analytical Transmission Electron Microscopy ◽  
Transmission Electron

The nature of a geologic fluid can often be inferred from fluid-filled cavities (generally <100 μm in size) that are trapped during the growth of a mineral. A variety of techniques enables the fluids and daughter crystals (any solid precipitated from the trapped fluid) to be identified from cavities greater than a few micrometers. Many minerals, however, contain fluid inclusions smaller than a micrometer. Though inclusions this small are difficult or impossible to study by conventional techniques, they are ideally suited for study by analytical/ transmission electron microscopy (A/TEM) and electron diffraction. We have used this technique to study fluid inclusions and daughter crystals in diamond and feldspar.Inclusion-rich samples of diamond and feldspar were ion-thinned to electron transparency and examined with a Philips 420T electron microscope (120 keV) equipped with an EDAX beryllium-windowed energy dispersive spectrometer. Thin edges of the sample were perforated in areas that appeared in light microscopy to be populated densely with inclusions. In a few cases, the perforations were bound polygonal sides to which crystals (structurally and compositionally different from the host mineral) were attached (Figure 1).

scholarly journals Quartz Crystallite Size and Moganite Content as Indicators of the Mineralogical Maturity of the Carboniferous Chert: The Case of Cherts from Eastern Asturias (Spain)

Minerals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 611
Author(s):  
Celia Marcos ◽  
María de Uribe-Zorita ◽  
Pedro Álvarez-Lloret ◽  
Alaa Adawy ◽  
Patricia Fernández ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Crystallite Size ◽  
Archaeological Sites ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Infrared And Raman Spectroscopy ◽  
First Time ◽  
Geological Formations

Chert samples from different coastal and inland outcrops in the Eastern Asturias (Spain) were mineralogically investigated for the first time for archaeological purposes. X-ray diffraction, X-ray fluorescence, transmission electron microscopy, infrared and Raman spectroscopy and total organic carbon techniques were used. The low content of moganite, since its detection by X-ray diffraction is practically imperceptible, and the crystallite size (over 1000 Å) of the quartz in these cherts would be indicative of its maturity and could potentially be used for dating chert-tools recovered from archaeological sites. Also, this information can constitute essential data to differentiate the cherts and compare them with those used in archaeological tools. However, neither composition nor crystallite size would allow distinguishing between coastal and inland chert outcrops belonging to the same geological formations.

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