Ultrastructural morphology of the uredium and collar formation during urediosporogenesis of Uromyces transversalis on gladiolus

1990 ◽  
Vol 68 (3) ◽  
pp. 605-612 ◽  
Author(s):  
Johan F. Ferreira ◽  
F. H. J. Rijkenberg
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Basal Cell ◽  
Basal Layer ◽  
Ultrastructural Morphology ◽  
Transmission Electron

The transverse uredia of Uromyces transversalis on gladiolus leaves were investigated by scanning and transmission electron microscopy. The basal cell forms one or more protuberances distally, each being delimited by a septum to become a urediospore initial. The initial elongates and lays down a septum to form a urediospore and pedicel. The first protuberance on the basal cell forms holoblastically, and evidence is found at the same locus for the subsequent enteroblastic formation of up to three successive urediospore initials. The pedicel wall of a spore thus formed remains on the basal cell and becomes a collar around the next protuberance. The basal layer of the two-layered septum that delimited the pedicel from the basal cell grows out to form the wall of the subsequent protuberance, and in the process ruptures and laterally displaces the terminal septal layer. A new basipetal septum forms to delimit the subsequent urediospore initial. In this manner, several collars form retrogressively and concentrically at one locus.

The influence of age on valve disease in patients with varicose veins analysed by transmission electron microscopy and stereology

VASA ◽  
2018 ◽  
Vol 47 (5) ◽  
pp. 409-416 ◽  
Author(s):  
Wolfgang G. Mouton ◽  
Michael O. Wagner ◽  
Beat Haenni ◽  
Kim T. Mouton ◽  
Matthias Ochs ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Varicose Veins ◽  
Rank Correlation ◽  
Venous Valve ◽  
Ultrastructural Morphology ◽  
Spearman’S Rank Correlation ◽  
Transmission Electron ◽  
The Mean ◽  
Venous Disorders

Abstract. Background: The aim of this study was to investigate the influence of age on the ultrastructure of venous valve morphology in patients with C2 classified chronic venous disorders according to the CEAP classification. Patients and methods: The study population consisted of 16 consecutive patients with varicose veins (C2). The mean age was 49.8 years (30–66). The (pre-) terminal valve including the vessel wall was harvested within the proximal 2 centimetres of the great saphenous vein. The mean thickness (volume-to-surface ratio = V/S ratio) of elastin, collagen, endothelium and of the entire valve was determined. A blinded morphologist performed the examination by transmission electron microscopy and stereology. Analyses by Pearson’s product moment correlation, Kendall’s tau and Spearman’s rank correlation were performed to investigate whether there is a correlation between age and the ultrastructural morphology. Results: Stereological analysis of the valves demonstrated a mean V/S ratio (signifying a thickness estimation) for elastin of 0.87 μm3/μm2, for collagen of 18.0 μm3/μm2, for endothelium of 0.65 μm3/μm2, and for the entire valve of 25.2 μm³/μm². Statistical analyses showed no statistically significant correlation between age and the ultrastructural morphology in this patient group. Conclusions: The ultrastructural morphology of the venous valves in chronic venous disorders may not depend on age in patients presenting with C2 disease. This conclusion may or may not apply to all C classes as we investigated a homogenous group of patients with C2 limbs.

scholarly journals Transmission Electron Microscopy as a Powerful Tool to Investigate the Interaction of Nanoparticles with Subcellular Structures

2021 ◽  
Vol 22 (23) ◽  
pp. 12789
Author(s):  
Manuela Malatesta
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Resolution ◽  
Nanoparticle Uptake ◽  
Ultrastructural Morphology ◽  
Functional Value ◽  
Transmission Electron ◽  
Biological Environment ◽  
Microscopy Techniques ◽  
The Impact

Nanomedical research necessarily involves the study of the interactions between nanoparticulates and the biological environment. Transmission electron microscopy has proven to be a powerful tool in providing information about nanoparticle uptake, biodistribution and relationships with cell and tissue components, thanks to its high resolution. This article aims to overview the transmission electron microscopy techniques used to explore the impact of nanoconstructs on biological systems, highlighting the functional value of ultrastructural morphology, histochemistry and microanalysis as well as their fundamental contribution to the advancement of nanomedicine.

Fine structure of teliospores of the cedar-apple rust Gymnosporangium juniperi-virginianae

1975 ◽  
Vol 53 (6) ◽  
pp. 544-552 ◽  
Author(s):  
Charles W. Mims ◽  
Frank Seabury ◽  
E. L. Thurston
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Fine Structure ◽  
Basal Cell ◽  
Spore Wall ◽  
Cellular Structures ◽  
Lipid Bodies ◽  
Germ Pore ◽  
Transmission Electron ◽  
Single Nucleus

Teliospores of the cedar-apple rust Gymnosporangium juniperi-virginianae were examined using transmission electron microscopy. Each ellipsoid spore is divided into two cells by a transverse septum. A second septum separates the basal cell of the teliospore from a long, hyaline, cylindrical pedicel. The fine structure of these septa is considered. The cytoplasm of the teliospore is very dense and contains a complement of cellular structures including ribosomes, vacuoles, mitochondria, and a large number of structures thought to be lipid bodies. Each cell of the teliospore contains a single nucleus, in which the chromatin is often considerably condensed. Two germ pore regions are present in each cell. The spore wall is thinnest in these regions and is different in structure than elsewhere around the spore.

scholarly journals Merkel-like cell distribution in the epithelium of the human vagina. An immunohistochemical and TEM study

2018 ◽  
Author(s):  
Simona Polakovičová ◽  
Mária Csӧbӧnyeiová ◽  
Barbora Filova ◽  
Miroslav Borovský ◽  
Ladislav Maršík ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Basal Layer ◽  
Anterior Wall ◽  
Vaginal Epithelium ◽  
Sexual Pleasure ◽  
Cytokeratin 20 ◽  
Merkel Cells ◽  
Transmission Electron ◽  
Human Vagina

Human Merkel cells (MCs) were first described by Friedrich S. Merkel in 1875 and named “Tastzellen” (touch cells). Merkel cells are primarily localized in the basal layer of the epidermis and concentrated in touch-sensitive areas. In our previous work, we reported on the distribution of MCs in the human esophagus, so therefore we chose other parts of the human body to study them. We selected the human vagina, because it has a similar epithelium as the esophagus and plays very important roles in reproduction and sexual pleasure. Due to the fact that there are very few research studies focusing on the innervation of this region, we decided to investigate the occurrence of MCs in the anterior wall of the vagina. The aim of our research was to identify MCs in the stratified squamous non-keratinized epithelium of the human vagina in 20 patients. For the identification of Merkel cells by light microscopy, we used antibodies against simple-epithelial cytokeratins (especially anti-cytokeratin 20). We also tried to identify them using transmission electron microscopy. Our investigation confirmed that 10 (50 %) of 20 patients had increased number of predominantly intraepithelial CK20 positive “Merkel-like” cells (MLCs) in the human vaginal epithelium. Subepithelial CK20 positive MLCs were observed in only one patient (5%). We tried to identify them also using transmission electron microscopy. Our investigation detected some unique cells that may be MCs. The purpose of vaginal innervation is still unclear. There are no data available concerning the distribution of MCs in the human vagina, so it would be interesting to study the role of MCs in the vaginal epithelium, in the context of innervation and epithelial biology.

Epidermal tags in clupeid fishes

1987 ◽  
Vol 67 (1) ◽  
pp. 135-143 ◽  
Author(s):  
A. C. G. Best ◽  
M. Whitear
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Basal Layer ◽  
Single Layer ◽  
Clupea Harengus ◽  
Merkel Cells ◽  
Nerve Fibres ◽  
Sprattus Sprattus ◽  
Transmission Electron ◽  
Small Nerve

The clupeid fishes Clupea harengus and Sprattus sprattus have small cellular tags projecting from the surface of the epidermis of the head and the margins of the scales. The tags are innervated and assumed to be tactile sensory organs. The fine structure has been investigated by scanning and transmission electron microscopy. The protruding part consists of a core of four columns of cells joined by numerous desmosomes, less firmly attached to a single layer of superficial cells. Fine, varicose, nerve fibres run under the superficial cells and end freely. Beneath the tag is a group of prominent basal layer cells and a dermal intrusion with a small nerve. No Merkel cells have been detected in the organs.

Ultrastructure of Conidia of the Plant Pathogenic Fungus Entomosporium Mespili

2000 ◽  
Vol 6 (S2) ◽  
pp. 688-689
Author(s):  
Elizabeth A. Richardson ◽  
Charles W. Mims
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Basal Cell ◽  
Fungal Pathogen ◽  
Pathogenic Fungus ◽  
Apical Cell ◽  
Freeze Substitution ◽  
Basal Cells ◽  
Mature Conidium ◽  
Transmission Electron

Entomosporium mespili has emerged as a significant pathogen of red tip (Photinia × fraseri), a popular and widely grown ornamental in the southeastern United States. This fungal pathogen produces its distinctive multi-celled, insect-like asexual spores or conidia (Fig. 1) in structures known as acervuli (Fig. 2) that rupture the surfaces of infected leaves. This study examines the fine structure of these conidia using a combination of scanning and transmission electron microscopy. In the case of transmission electron microscopy, conidia were prepared for study using either plunge freezing or high pressure freezing followed by freeze substitution.Each mature conidium of E. mespili consists of four to six cells (Fig. 1). These include one apical cell and one basal cell and two to four small lateral cells attached to the basal cell. The apical and lateral cells each possess a long, slender appendage. Excluding these appendages, the length of a mature conidium is usually 20-24μm while the diameters of the apical and basal cells are 8-11μm and 6-9μm respectively.

scholarly journals The crosslinking effect of photorefractive ablation with riboflavin evaluated with transmission electron microscopy

2019 ◽  
pp. 45-50
Author(s):  
С.А. Борзенок ◽  
И.М. Корниловский ◽  
А.А. Бурцев ◽  
А.В. Шацких
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Basal Layer ◽  
Corneal Stroma ◽  
Collagen Fibers ◽  
Control Group ◽  
Transmission Electron ◽  
Cross Links ◽  
Optical Level

Трансмиссионная электронная микроскопия является одним из ключевых маркёров при рассмотрении патогенеза коллагенового кросслинкинга. Цель работы: оценить эффект кросслинкинга при фоторефракционной кератоабляции с рибофлавином по данным трансмиссионной электронной микроскопии. Материал и методы. Экспериментальное исследование было выполнено in vivo на 16 глазах 16 кроликов породы Шиншилла, с массой тела от 2,5 до 3,5кг, в возрасте от 1 до 1,5 лет. Животные были разделены на контрольную и опытную группы по 8 животных на каждый из способов проведения трансэпителиальной фоторефракционной кератоэктомии (ТрансФРК), без и с предварительным насыщением стромы 0,25% изотоническим раствором рибофлавина. На светооптическом уровне исследовали эпителий, наружные и глубокие слои стромы в проекции оперативного вмешательства. По данным трансмиссионной электронной микроскопии оценивали волокна и пучки коллагена, и их концентрацию на единицу площади, а также клеточный компонент стромы роговицы в проекции оперативного вмешательства. Результаты. На светооптическом уровне роговица кролика по завершению эпителизации сохраняла нормальную морфологию плоского многослойного неороговевающего эпителия, с практически полным восстановлением стратификации слоев. В случае образцов после абляции с предварительным насыщением стромы раствором рибофлавина наблюдались единичные вакуоли в клетках базального слоя и появление псевдомногорядности. Комплексной морфологической оценкой установлено, что роговицы из экспериментальной группы (с предварительным насыщением стромы рибофлавином) были подвержены изменениям соответствующим крослинкингу стромы с формированием стабильных поперечных сшивок коллагеновых волокон. В роговицах контрольной группы без насыщения стромы рибофлавином морфологически выявлено полное восстановление структуры после лазерного воздействия без признаков кросслинкинга стромы. Заключение. После проведения эксимерлазерной абляции с рибофлавином обнаруженные при трансмиссионной электронной микроскопии стабильные сшивки в коллагеновых структурах стромы роговицы подтверждают наличие эффекта крослинкинга при таком способе фоторефракционной кератоэктомии. Transmission electron microscopy is one of the key methods in studying the pathogenesis of collagen crosslinking. Aim. To evaluate the effect of crosslinking induced by photorefractive ablation of the cornea with riboflavin using transmission electron microscopy. Material and methods. This experimental in vivo study was performed on 16 eyes of 16 Chinchilla rabbits weighing from 2.5 to 3.5 kg, aged from 1 to 1.5 years. Animals were divided into control and experimental groups, including 8 animals for each of the transepithelial photorefractive keratoectomy (TransFRK) methods, with and without prior saturation of the stroma with a 0.25% isotonic riboflavin solution., The epithelium and outer and deep layers of the stroma were studied in the projection of surgery at the light-optical level. Based on data of the transmission electron microscopy, collagen fibers and bundles, and their concentration per unit area, and the cellular component of corneal stroma were evaluated. Results. The rabbit cornea studied at the light-optical level upon completion of epithelialization maintained a normal morphology of the flat multi-layered non-squamous epithelium with almost complete recovery of the layer stratification. In post-ablation samples with the prior saturation of stroma with riboflavin solution, isolated vacuoles were observed in cells of the basal layer along with emergence of pseudostratified epithelium. According to results of the complex morphological evaluation, corneas of the experimental group (with riboflavin pre-saturation of the stroma) showed changes corresponding to the stroma crosslinking with formation of stable cross-links of collagen fibers. In the cornea of the control group (without riboflavin saturation of the stroma), the stromal structure completely recovered after the laser treatment without any signs of stromal crosslinking. Conclusion. As detected by transmission electron microscopy, the stable cross-links in collagen structures of the corneal stroma induced by excimer laser ablation with riboflavin confirm the presence of the crosslinking effect in using the given method of the photorefractive keratoectomy.

scholarly journals Monitoring morphology and signal during non-radioactive in situ hybridization procedures by reflection-contrast microscopy and transmission electron microscopy.

1995 ◽  
Vol 43 (7) ◽  
pp. 665-674 ◽  
Author(s):  
M V Macville ◽  
A G Van Dorp ◽  
K C Wiesmeijer ◽  
R W Dirks ◽  
J A Fransen ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
In Situ Hybridization ◽  
Messenger Rna ◽  
Detection Efficiency ◽  
Rna Detection ◽  
Ultrastructural Morphology ◽  
Transmission Electron ◽  
Contrast Microscopy

We analyzed the effects of steps in RNA in situ hybridization (ISH) procedures on morphology and hybridization signal with reflection-contrast microscopy (RCM) and transmission electron microscopy (TEM). In chessboard experiments, a range of fixatives containing formaldehyde, glutaraldehyde, or both, and various permeabilization protocols, including ethanol and pepsin treatment, were investigated. A transfected rat fibroblast cell line that harbors an inducible human cytomegalovirus immediate early (IE) transcription unit, and specific probes for 28S ribosomal RNA and IE messenger RNA were used for this purpose. Probes were labeled with digoxigenin and hybrids were detected with anti-digoxigenin F(ab)2 fragments conjugated to horseradish peroxidase, followed by diaminobenzidine/H2O2 reaction. Effects of fixation and pre-treatments on RNA detection efficiency and morphology were monitored by RCM on whole cells. After Epon embedding and ultra-thin cross-sectioning, the corresponding TEM images were obtained. With the pre-treatments analyzed, it appeared impossible to find an acceptable balance between ISH signals and preservation of ultrastructural morphology: when good signal-to-noise ratios are obtained, the ultrastructural morphology is already deteriorated. We discuss the parameters that influence the fragile balance between high RNA detection efficiency and good preservation of ultrastructure and the benefit of RCM monitoring in the development and procedures for pre-embedding electron microscopic ISH.

Techniques for Transmission Electron Microscopy of Fiber-Matrix Interfaces in Aluminum Alloy-Boron Composites by Ion Erosio

1971 ◽  
Vol 29 ◽  
pp. 204-205
Author(s):  
G. G. Shaw
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Aluminum Alloy ◽  
Electron Beam ◽  
Pure Aluminum ◽  
Ion Milling ◽  
Transmission Electron ◽  
Fiber Matrix ◽  
Ion Erosion ◽  
Row Of Fibers

The morphology and composition of the fiber-matrix interface can best be studied by transmission electron microscopy and electron diffraction. For some composites satisfactory samples can be prepared by electropolishing. For others such as aluminum alloy-boron composites ion erosion is necessary.When one wishes to examine a specimen with the electron beam perpendicular to the fiber, preparation is as follows: A 1/8 in. disk is cut from the sample with a cylindrical tool by spark machining. Thin slices, 5 mils thick, containing one row of fibers, are then, spark-machined from the disk. After spark machining, the slice is carefully polished with diamond paste until the row of fibers is exposed on each side, as shown in Figure 1.In the case where examination is desired with the electron beam parallel to the fiber, preparation is as follows: Experimental composites are usually 50 mils or less in thickness so an auxiliary holder is necessary during ion milling and for easy transfer to the electron microscope. This holder is pure aluminum sheet, 3 mils thick.

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