scholarly journals Morphological and Ultrastructural Characterization of Hemocytes in an Insect Model, the Hematophagous Dipetalogaster maxima (Hemiptera: Reduviidae)

Insects ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 640
Author(s):  
Natalia R. Moyetta ◽  
Fabián O. Ramos ◽  
Jimena Leyria ◽  
Lilián E. Canavoso ◽  
Leonardo L. Fruttero
Keyword(s):  
Cell Biology ◽  
Cell Types ◽  
Transmission Electron ◽  
Ultrastructural Characterization ◽  
Current Classification ◽  
Contrast Microscopy ◽  
First Time ◽  
Controversial Aspect

Hemocytes, the cells present in the hemolymph of insects and other invertebrates, perform several physiological functions, including innate immunity. The current classification of hemocyte types is based mostly on morphological features; however, divergences have emerged among specialists in triatomines, the insect vectors of Chagas’ disease (Hemiptera: Reduviidae). Here, we have combined technical approaches in order to characterize the hemocytes from fifth instar nymphs of the triatomine Dipetalogaster maxima. Moreover, in this work we describe, for the first time, the ultrastructural features of D. maxima hemocytes. Using phase contrast microscopy of fresh preparations, five hemocyte populations were identified and further characterized by immunofluorescence, flow cytometry and transmission electron microscopy. The plasmatocytes and the granulocytes were the most abundant cell types, although prohemocytes, adipohemocytes and oenocytes were also found. This work sheds light on a controversial aspect of triatomine cell biology and physiology setting the basis for future in-depth studies directed to address hemocyte classification using non-microscopy-based markers.

scholarly journals Morphological characterization of hemocytes in Ectemnaspis rorotaense (Floch & Abonnenc) and Ectemnaspis trombetense (Hamada, Py-Daniel & Adler) (Diptera: Simuliidae)

2015 ◽  
Vol 8 (3) ◽  
pp. 209-213
Author(s):  
Juciane Conceição da Silva ◽  
Felipe Arley Costa Pessoa ◽  
Cláudia Maria Ríos-Velásquez ◽  
Helena Rocha Côrrea de Araújo ◽  
Ana Paula Sampaio Feitosa ◽  
...  
Keyword(s):  
Cell Types ◽  
Microscopy Study ◽  
Morphological Characterization ◽  
Electron Microscopy Study ◽  
Black Flies ◽  
Morphological Variations ◽  
Transmission Electron ◽  
Amazonas State ◽  
First Time

Abstract. Hemocytes are insect immune cells which are responsible for processes of phagocytosis, encapsulation, and coagulation. This study aim to characterize the hemocyte cells in two species amazon blackflies: Ectemnaspis rorotaense (Floch & Abonnenc) and Ectemnaspis trombetense (Hamada, Py-Daniel & Adler). Black fly larvae and pupae were collected from streams in Presidente Figueiredo Municipality, Amazonas State, Brazil. Hemolymph of 36 individuals of E. rorotaense (12 larvae, 12 pupae and 12 adults) and 38 of E. trombetense (12 larvae, 12 pupae and 14 adults) were collected and the cells were characterized by light microscopy; 200 adults of each species were used to transmission electron microscopy study. In this work were showed, by the first time, the hemocyte cells of black flies amazon. Four cell types were identified: prohemocytes, granulocytes, oenocytoids, and plasmatocytes. Prohemocytes were the smallest cells and they exhibited a high nuclear-cytoplasmic ratio. Granulocytes possessed large, eccentric nuclei, and they were characterized by the presence of granules that differed in size and shape. Oenocytoids presented poorly developed nucleus with localization in central region. Plasmatocytes showed more morphological variations and large projections in the cytoplasmic membrane. The prohemocytes were the most frequent in E. rorotaense, with nearby 45% of total cells, whereas plasmatocytes and granulocytes, each one with 38%, were the most abundant in E. trombetense. This study showed that prohemocytes, granulocytes, oenocytoids, and plasmatocytes were present in the hemolymph of E. rorotaense and E. trombetense during all stages.Caracterização Morfológica de Hemócitos em Ectemnaspis rorotaense (Floch & Abonnenc) e Ectemnaspis trombetense (Hamada, Py-Daniel & Adler) (Diptera: Simuliidae)Resumo. Os hemócitos são células do sistema imune dos insetos responsáveis pelos processos de fagocitose, encapsulação e coagulação. O objetivo desse trabalho foi caracterizar os hemócitos nos simulídeos amazônicos, Ectemnaspis rorotaense (Floch & Abonnenc)e Ectemnaspis trombetense (Hamada, Py-Daniel & Adler). Larvas e pupas de simulídeos foram coletadas em igarapés no município de Presidente Figueiredo, Amazonas, Brasil. Para caracterização celular através da microscopia óptica, foi coletada a hemolinfa de 36 espécimes (12 larvas, 12 pupas e 12 adultos) de E. rorotaense e 38 espécimes (12 larvas, 12 pupas e 14 adultos) de E. trombetense. Para o estudo com microscopia eletrônica de transmissão, 200 adultos de cada espécie foram utilizados. Neste trabalho foram descritos, pela primeira vez, os hemócitos de simulídeos amazônicos. Foram identificados quatro tipos celulares em larvas, pupas e adultos: prohemócitos, plasmatócitos, granulócitos e oenocitóides. Os prohemócitos, com um núcleo volumoso em relação ao citoplasma, se mostraram as menores células. Os granulócitos foram caracterizados pela presença de grânulos de diferentes tamanhos e formas e um núcleo grande e excêntrico. Os oenocitóides revelaram núcleo pouco desenvolvido, geralmente localizado na região central. Os plasmatócitos apresentaram grandes projeções da membrana citoplasmática e maior variação morfológica. Os prohemócitos foram as células mais frequentes em E. rorotaense com 45% do total das células, enquanto os plasmatócitos e granulócitos, ambas com 38% cada, foram as mais abundantes em E. trombetense. Esse estudo mostrou que prohemócitos, granulócitos, oenocitóides e plasmatócitos são presentes na hemolinfa de E. rorotaense and E. trombetense durante todos os estágios.

scholarly journals Cytoplasmic nanojunctions between lysosomes and sarcoplasmic reticulum are required for specific calcium signaling

2014 ◽  
Author(s):  
Nicola Fameli ◽  
Oluseye A. Ogunbayo ◽  
Cornelis van Breemen ◽  
A. Mark Evans
Keyword(s):  
Sarcoplasmic Reticulum ◽  
Ryanodine Receptor ◽  
Membrane Separation ◽  
Quantitative Model ◽  
Transmission Electron ◽  
Ultrastructural Characterization ◽  
Health And Disease ◽  
Pulmonary Artery Smooth Muscle ◽  
Subtype 3

We demonstrate how nanojunctions between lysosomes and sarcoplasmic reticulum (L-SR junctions) serve to couple lysosomal activation to regenerative, ryanodine receptor-mediated cellular calcium (Ca2+) waves. In pulmonary artery smooth muscle cells (PASMCs) nicotinic acid adenine dinucleotide phosphate (NAADP) may trigger increases in cytoplasmic Ca2+ via L-SR junctions, in a manner that requires initial Ca2+ release from lysosomes and subsequent Ca2+-induced Ca2+ release (CICR) via ryanodine receptor (RyR) subtype 3 on the SR membrane proximal to lysosomes. L-SR junction membrane separation has been estimated to be <400 nm and thus beyond the resolution of light microscopy. This study utilizes transmission electron microscopy to provide a thorough ultrastructural characterization of the L-SR junctions in PASMCs. These junctions are prominent features in these cells and we estimate that the membrane separation and extension are about 15 nm and 300 nm, respectively. We also develop a quantitative model of the L-SR junction using these measurements, prior kinetic and specific Ca2+ signal information as input data. Simulations of NAADP-dependent junctional Ca2+ transients show that the magnitude of these signals can breach the threshold for CICR via RyR3. By correlation analysis of live cell Ca2+ signals and simulated L-SR junctional Ca2+ transients, we estimate that "trigger zones" with a 60-100 junctions are required to confer a signal of similar magnitude. This is compatible with the 130 lysosomes/cell estimated from our ultrastructural observations. Most importantly, our model shows that increasing the L-SR junctional width above 50 nm lowers the magnitude of junctional [Ca2+] such that there is a failure to breach the threshold for CICR via RyR3. L-SR junctions are therefore a pre-requisite for efficient Ca2+ signal coupling and may contribute to cellular function in health and disease.

scholarly journals A Novel Genotype and First Record of Trypanosoma lainsoni in Argentina

Pathogens ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 731
Author(s):  
Anahí G. Díaz ◽  
Paula G. Ragone ◽  
Fanny Rusman ◽  
Noelia Floridia-Yapur ◽  
Rubén M. Barquez ◽  
...  
Keyword(s):  
Host Range ◽  
First Record ◽  
Morphological Characterization ◽  
Pairwise Identity ◽  
Wild Mammals ◽  
Transmission Electron ◽  
Chaco Region ◽  
Veterinary Importance ◽  
First Time

Trypanosomes are a group of parasitic flagellates with medical and veterinary importance. Despite many species having been described in this genus, little is known about many of them. Here, we report a genetic and morphological characterization of trypanosomatids isolated from wild mammals from the Argentine Chaco region. Parasites were morphologically and ultrastructurally characterized by light microscopy and transmission electron microscopy. Additionally, 18s rRNA and gGAPDH genes were sequenced and analyzed using maximum likelihood and Bayesian inference. Morphological characterization showed clear characteristics associated with the Trypanosoma genus. The genetic characterization demonstrates that the studied isolates have identical sequences and a pairwise identity of 99% with Trypanosoma lainsoni, which belongs to the clade of lizards and snakes/rodents and marsupials. To date, this species had only been found in the Amazon region. Our finding represents the second report of T. lainsoni and the first record for the Chaco region. Furthermore, we ultrastructurally described for the first time the species. Finally, the host range of T. lainsoni was expanded (Leopardus geoffroyi, Carenivora, Felidae; and Calomys sp., Rodentia, Cricetidae), showing a wide host range for this species.

scholarly journals NuSTAR reveals that the heavily obscured nucleus of NGC 2785 was the contaminant of IRAS 09104+4109 in the BeppoSAX/PDS hard X-rays

2018 ◽  
Vol 619 ◽  
pp. A16
Author(s):  
C. Vignali ◽  
P. Severgnini ◽  
E. Piconcelli ◽  
G. Lanzuisi ◽  
R. Gilli ◽  
...  
Keyword(s):  
X Rays ◽  
X Ray ◽  
Star Forming ◽  
Physical Description ◽  
Enhanced Sensitivity ◽  
X Ray Imaging ◽  
First Time ◽  
In Virtue Of

Context. The search for heavily obscured active galactic nuclei has been revitalized in the last five years by NuSTAR, which has provided a good census and spectral characterization of a population of such objects, mostly at low redshift, thanks to its enhanced sensitivity above 10 keV compared to previous X-ray facilities, and its hard X-ray imaging capabilities. Aims. We aim at demonstrating how NGC 2785, a local (z = 0.009) star-forming galaxy, is responsible, in virtue of its heavily obscured active nucleus, for significant contamination in the non-imaging BeppoSAX/PDS data of the relatively nearby (≈17′) quasar IRAS 09104+4109 (z = 0.44), which was originally mis-classified as Compton thick. Methods. We analyzed ≈71 ks NuSTAR data of NGC 2785 using the MYTorus model and provided a physical description of the X-ray properties of the source for the first time. Results. We found that NGC 2785 hosts a heavily obscured (NH ≈ 3 × 1024 cm−2) nucleus. The intrinsic X-ray luminosity of the source, once corrected for the measured obscuration (L2−10keV ≈ 1042 erg s−1), is consistent within a factor of a few with predictions based on the source mid-infrared flux using widely adopted correlations from the literature. Conclusions. Based on NuSTAR data and previous indications from the Neil Gehrels Swift Observatory (BAT instrument), we confirm that NGC 2785, because of its hard X-ray emission and spectral shape, was responsible for at least one third of the 20–100 keV emission observed using the PDS instrument onboard BeppoSAX, originally completely associated with IRAS 09104+4109. Such emission led to the erroneous classification of this source as a Compton-thick quasar, while it is now recognized as Compton thin.

scholarly journals Ontogenic, phenotypic, and functional characterization of XCR1+ dendritic cells leads to a consistent classification of intestinal dendritic cells based on the expression of XCR1 and SIRPα

2014 ◽  
Author(s):  
Martina Becker ◽  
Steffen Güttler ◽  
Annabell Bachem ◽  
Evelyn Hartung ◽  
Ahmed Mora ◽  
...  
Keyword(s):  
Dendritic Cells ◽  
T Cell ◽  
Functional Characterization ◽  
Cross Presentation ◽  
Intestinal Immune System ◽  
Lineage Marker ◽  
And Function ◽  
First Time

In the past, lack of lineage markers confounded the classification of dendritic cells (DC) in the intestine and impeded a full understanding of their location and function. We have recently shown that the chemokine receptor XCR1 is a lineage marker for cross-presenting DC in the spleen. Now we provide evidence that intestinal XCR1+ DC largely, but not fully, overlap with CD103+ CD11b- DC, the hypothesized correlate of “cross-presenting DC” in the intestine, and are selectively dependent in their development on the transcription factor Batf3. XCR1+ DC are located in the villi and epithelial crypts of the lamina propria of the small intestine, the T cell zones of Peyer’s Patches, and in the T cell zones and sinuses of the draining mesenteric lymph node. Functionally, we could demonstrate for the first time that XCR1+ / CD103+ CD11b- DC excel in the cross-presentation of orally applied antigen. Together, our data show that XCR1 is a lineage marker for cross-presenting DC also in the intestinal immune system. Further, extensive phenotypic analyses reveal that expression of the integrin SIRPα consistently demarcates the XCR1- DC population. We propose a simplified and consistent classification system for intestinal DC based on the expression of XCR1 and SIRPα.

Electron Microscopy Findings inN-Methyl-N-Nitrosourea-Induced Mammary Tumors

2016 ◽  
Vol 22 (5) ◽  
pp. 1056-1061
Author(s):  
Ana I. Faustino-Rocha ◽  
Ana M. Calado ◽  
Adelina Gama ◽  
Rita Ferreira ◽  
Mário Ginja ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Rat Model ◽  
Mammary Tumors ◽  
Female Rats ◽  
Ultrastructural Studies ◽  
Transmission Electron ◽  
Chemically Induced ◽  
Ultrastructural Characterization ◽  
Human Mammary Tumors

AbstractAlthough the rat model of mammary tumors chemically induced byN-methyl-N-nitrosourea (MNU) has been frequently used by several research teams, there is a lack of ultrastructural studies in this field. The main aim of this work was to perform an ultrastructural characterization of MNU-induced mammary tumors in female rats. Some alterations previously reported in human mammary tumors, such as nucleus size and shape, accumulation of heterochromatin in the perinuclear region, and interdigitating cytoplasmic processes between cancer cells were also observed in MNU-induced mammary tumors. Although a low number of samples were analyzed by transmission electron microscopy in the present study, we consider that it may contribute to a better understanding of MNU-induced mammary carcinogenesis in a rat model. The ultrastructural characteristics of the two most frequently diagnosed mammary carcinomas described in the present work can be useful to differentiate them from other histological patterns. In addition, the loss of cytoplasm in neoplastic cells and formation of vacuoles were described.

A morphological classification of the fat particles found in the urinary sediment of patients with Fabry disease

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Giovanni B. Fogazzi ◽  
Giuseppe Garigali ◽  
Federico Pieruzzi ◽  
Alessandro Corbelli ◽  
Fabio Fiordaliso ◽  
...  
Keyword(s):  
Fabry Disease ◽  
Polarized Light ◽  
Control Group ◽  
Morphological Classification ◽  
Urinary Sediment ◽  
Transmission Electron ◽  
Three Samples ◽  
Contrast Microscopy ◽  
Fat Particles

Abstract Objectives The search in the urinary sediment (U-sed) of fat particles with peculiar morphology is a simple and inexpensive tool for the diagnosis of Fabry disease (FD) nephropathy. In this study we investigated the morphology of a high number of such fat particles with the aim to obtain a morphological classification to be used for their identification. Methods Study of the morphology of fat particles in the U-sed of a cohort of FD patients using: bright field plus phase contrast microscopy (BF + PC), polarized light microscopy (POL), and transmission electron microscopy (TEM). Comparison of these results with those obtained for the fat particles seen in the U-sed of a control group (CG) of patients with non-FD glomerulopathies. Results FD: 18 U-sed from six patients (three samples/patient) were prospectively investigated and 506 fat particles identified. With BF + PC, these were classified in eight morphological categories (seven of which were confirmed by TEM), and with POL in 10 others. CG: eight U-sed from eight patients were investigated and 281 fat particles identified. These fell into four BF + PC morphological categories and into eight POL categories. While some categories were significantly more frequent in FD others were more frequent in the CG. Conclusions Our study demonstrates that 1. The morphology of fat particles found in the U-sed of FD patients is much wider and complex than that described so far 2. Several significant differences exist in the morphology of such fat particles between FD and CG patients.

Ultrastructural Characterization of Liposomes Using Transmission Electron Microscope

2008 ◽  
Vol 55-57 ◽  
pp. 709-711 ◽  
Author(s):  
Prukswan Chetanachan ◽  
P. Akarachalanon ◽  
D. Worawirunwong ◽  
Pisutti Dararutana ◽  
A. Bangtrakulnonth ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Transmission Electron Microscope ◽  
Polymeric Nanoparticles ◽  
Staining Technique ◽  
Bilayer Membrane ◽  
Multilamellar Vesicles ◽  
Transmission Electron ◽  
Ultrastructural Characterization ◽  
Film Method

A liposome is a spherical vesicle composed of phospholipids and cholesterol bilayer membrane and contains a core of aqueous solution. Liposomes are polymeric nanoparticles used for drug delivery due to their unique properties. It can carry both hydrophobic and hydrophilic molecules. In this study, we showed the benefit of using transmission electron microscope (TEM) with negative staining technique to investigate the morphology of liposomes produced by thin film method. At the same magnification of micrograph results, we could see the multilamellar vesicles of liposomes in various figures and different sizes.

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