Ultrastructure of feline calicivirus-infected crandell's feline kidney (CRFK) cells in culture

1988 ◽  
Vol 46 ◽  
pp. 310-311
Author(s):  
C. P. Dick ◽  
R.P. Johnson ◽  
T. Bast ◽  
S. Yamashiro
Keyword(s):  
Cytopathic Effect ◽  
In Vitro Models ◽  
Respiratory Pathogen ◽  
Feline Calicivirus ◽  
Cytopathic Effects ◽  
Transmission Electron ◽  
Upper Respiratory ◽  
Viral Inclusions ◽  
Median Cell

Viruses frequently are difficult to visualize using routine transmission electron microscopy (TEM) of tissues collected from infected animals. Using cell cultures infected with viruses as in vitro models, viral replication and their resultant cytopathic effects can be more easily examined.Feline calicivirus (FCV), a common upper respiratory pathogen in cats has been successfully propagated in Crandell's Feline Kidney (CRFK) cells and a number of ultrastructural viral inclusions noted (1-4). This study represents further investigation of FCV infected CRFK cells using strain 255. The similarities and differences in our findings as compared to those of previous investigations have been explored.Confluent monolayers of CRFK cells in 80 cm2 plastic flasks were inoculated with 105 median cell culture infectious doses of FCV strain 255. When approximately 60 percent of cells exhibit FCV cytopathic effect the medium was decanted and the cells scraped from the surface using a rubber policeman. The cell suspension was centrifuged at 5000 rpm for 20 minutes at 4°C. Details of the procedure have been reported previously (5).

scholarly journals Morphological Features andIn VitroCytopathic Effect ofAcanthamoeba griffiniTrophozoites Isolated from a Clinical Case

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Arturo González-Robles ◽  
Lizbeth Salazar-Villatoro ◽  
Maritza Omaña-Molina ◽  
Maria Reyes-Batlle ◽  
Carmen M. Martín-Navarro ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Clinical Case ◽  
Cell Injury ◽  
Cytopathic Effect ◽  
Mdck Cells ◽  
Target Cells ◽  
Small Areas ◽  
Transmission Electron

Light and transmission electron microscopy observations are reported on the structure andin vitrocytopathic effect ofAcanthamoeba griffinitrophozoites isolated from a clinical case. Live trophozoites were moderately active with a remarkable pleomorphism which changed from ovoid to quite elongated shapes. When moving, amoebae formed cytoplasmic projections such as wide lamellae and acanthopodia of diverse size and thickness which contain a significant amount of actin. Ultrastructurally, the cytoplasm showed the main organelles found in other free-living amoebae. Coincubation of trophozoites with MDCK cell monolayers resulted in a local damage to target cells after 24 h of interaction, suggesting that the cytopathic effect is contact-dependent. By transmission electron microscopy, amoebae appeared to engulf small portions of the MDCK cells; however, the cells that were not in contact with trophozoites had an unaltered morphology. When epithelial monolayers were incubated with conditioned medium for 24 h, small areas of cell injury were also observed. The phylogenetical analysis as well as the sequencing of the acquired amplified product for the DF3 region of the amoebae isolate confirmed that it belongs to genotype T3, which includes other pathogenic amoebae; besides the activity of two drugs currently used againstAcanthamoebawas tested onA. griffini.

scholarly journals Active Phagocytosis and Diachronic Processing of Calcium Oxalate Monohydrate Crystals in an in vitro Macrophage Model

2019 ◽  
Vol 44 (5) ◽  
pp. 1014-1025
Author(s):  
Atsushi Okada ◽  
Hiromasa Aoki ◽  
Daichi Onozato ◽  
Taiki Kato ◽  
Tadahiro Hashita ◽  
...  
Keyword(s):  
Light Microscopy ◽  
Calcium Oxalate ◽  
Polarized Light ◽  
Calcium Oxalate Monohydrate ◽  
In Vitro Models ◽  
Polarized Light Microscopy ◽  
Transmission Electron ◽  
Imaging Cytometry ◽  
Acidic Organelles

Background: We previously discovered that renal macrophages (Mφs) phagocytose renal calcium oxalate monohydrate (COM) crystals. This study investigated the processing of engulfed crystals using in vitro models. Methods: J774.1 mouse Mφs were exposed to COM crystals and observed for 24 h using polarized light microscopy with/without cytochalasin B (CB), an inhibitor of phagocytosis, to confirm active crystal phagocytosis. LysoTracker and immunohistochemical staining using transmission electron microscopy for lysosomal-associated membrane protein 1 were used to confirm engulfed COM crystal uptake into lysosomes. Diachronic tracking of specific Mφs was performed to capture the entire course of engulfed COM crystal processing using polarized light microscopy. Follow-up studies of fluorescent COM (f-COM) crystals using imaging cytometry were performed in the presence and absence of nigericin to dissipate the pH gradient in acidic organelles. Results: Phagocytosis rates increased with COM density and were significantly lower in cells treated with CB (p < 0.01). We observed that engulfed crystals colocalized within lysosomes of the Mφs; moreover, diachronic observation indicated that the engulfed COM crystals were subdivided during Mφ division and eliminated by the 7th day of culture. Additionally, imaging cytometry showed that the fluorescence level of f-COM crystals in the nigericin (–) group after 48 h was significantly lower than that in the nigericin (+) group. Conclusions: This study confirmed active phagocytosis and lysosomal processing of engulfed COM crystals by Mφs. This discovery is expected to contribute to the development of future drugs that enhance the COM crystal phagocytic ability of Mφs.

Opinion on the Optimal Histologic Evaluation of the Bone Marrow in Nonclinical Toxicity Studies

2021 ◽  
pp. 019262332110617
Author(s):  
Kathleen E. Biddle
Keyword(s):  
Bone Marrow ◽  
Complete Blood Count ◽  
Critical Role ◽  
In Vitro Models ◽  
Standard Approach ◽  
Histological Evaluation ◽  
Bone Marrow Toxicity ◽  
Transmission Electron ◽  
Histologic Evaluation

Identification of bone marrow toxicity is an important issue in drug development and toxicologic pathologists play a critical role in that identification. Knowledge of the general components of bone marrow, relevant anatomical and species differences, and the standard approach (routine systematic histological evaluation of the bone marrow in conjunction with analysis of the peripheral complete blood count data) will be reviewed. Specific morphologic features that anatomic pathologists should look for in the various components of bone marrow as well as suggested terminology for bone marrow findings will be discussed. Finally, an opinion on the limitations of the standard approach to bone marrow evaluation will be provided including general recommendations on when additional methods (image analysis of hematoxylin and eosin stained slides, flow cytometry or Sysmex XT 2000iV analysis, cytological evaluation of bone marrow smears, in vitro models, and transmission electron microscopy) might be useful in the detection or further characterization of bone marrow toxicity. [Box: see text]

scholarly journals Role of the Corneal Epithelial Basement Membrane in Ocular Defense against Pseudomonas aeruginosa

2009 ◽  
Vol 77 (8) ◽  
pp. 3264-3271 ◽  
Author(s):  
Irania Alarcon ◽  
Lesley Kwan ◽  
Chong Yu ◽  
David J. Evans ◽  
Suzanne M. J. Fleiszig
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Basement Membrane ◽  
In Vitro Models ◽  
Corneal Epithelial ◽  
Barrier Effects ◽  
Epithelial Basement Membrane ◽  
Transmission Electron ◽  
Superficial Epithelium

ABSTRACT Pseudomonas aeruginosa can invade corneal epithelial cells and translocates multilayered corneal epithelia in vitro, but it does not penetrate the intact corneal epithelium in vivo. In healthy corneas, the epithelium is separated from the underlying stroma by a basement membrane containing extracellular matrix proteins and pores smaller than bacteria. Here we used in vivo and in vitro models to investigate the potential of the basement membrane to defend against P. aeruginosa. Transmission electron microscopy of infected mouse corneas in vivo showed penetration of the stroma by P. aeruginosa only where the basement membrane was visibly disrupted by scratch injury, suggesting that the intact basement membrane prevented penetration. This hypothesis was explored using an in vitro Matrigel Transwell model to mimic the corneal basement membrane. P. aeruginosa translocation of multilayered corneal epithelia grown on Matrigel was ∼100-fold lower than that of cells grown without Matrigel (P < 0.005, t test). Matrigel did not increase transepithelial resistance. Matrigel-grown cells blocked translocation by a P. aeruginosa protease mutant. Without cells, Matrigel also reduced traversal of P. aeruginosa and the protease mutant. Fluorescence microscopy revealed a relative accumulation of bacteria at the superficial epithelium of cells grown on Matrigel at 3 h compared to cells grown on uncoated filters. By 5 h, bacteria accumulated beneath the cells, suggesting direct trapping by the Matrigel. These findings suggest that the basement membrane helps defend the cornea against infection via physical barrier effects and influences on the epithelium and that these roles could be compromised by P. aeruginosa proteases.

scholarly journals SARS-CoV-2 Short-Time Infection Produces Relevant Cytopathic Effects in Vero E6 Cell Line

2021 ◽  
Vol 18 (17) ◽  
pp. 9020
Author(s):  
Luisa Zupin ◽  
Francesco Fontana ◽  
Rossella Gratton ◽  
Margherita Milani ◽  
Libera Clemente ◽  
...  
Keyword(s):  
Cytopathic Effect ◽  
Infected Individual ◽  
Cellular Model ◽  
Cytopathic Effects ◽  
Minimal Quantity ◽  
Virus Exposure ◽  
Short Time ◽  
Respiratory Droplets

Severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) is mainly transmitted through respiratory droplets from positive subjects to susceptible hosts or by direct contact with an infected individual. Our study focuses on the in vitro minimal time of viral absorption as well as the minimal quantity of virus able to establish a persistent infection in Vero E6 cells. We observed that 1 min of in vitro virus exposure is sufficient to generate a cytopathic effect in cells after 7 days of infection, even at a multiplicity of infection (MOI) value of 0.01. Being aware that our findings have been obtained using an in vitro cellular model, we demonstrated that short-time exposures and low viral concentrations are able to cause infection, thus opening questions about the risk of SARS-CoV-2 transmissibility even following short contact times.

scholarly journals Nanoparticle composite TPNT1 is effective against SARS-CoV-2 and influenza viruses

2020 ◽  
Author(s):  
Sui-Yuan Chang ◽  
Kuo-Yen Huang ◽  
Tai-Ling Chao ◽  
Han-Chieh Kao ◽  
Yu-Hao Pang ◽  
...  
Keyword(s):  
Viral Entry ◽  
Opportunistic Infections ◽  
Food Additives ◽  
Syncytium Formation ◽  
Influenza Viruses ◽  
Metal Nanoparticle ◽  
Cytopathic Effects ◽  
H5n1 Influenza ◽  
Transmission Electron

Abstract A metal nanoparticle composite TPNT1, which contains Au-NP (1 ppm), Ag-NP (5 ppm), ZnO-NP (60 ppm) and ClO2 (42.5 ppm) in aqueous solution was prepared and characterized by spectroscopy, transmission electron microscopy, dynamic light scattering analysis and potentiometric titration. Based on the in vitro cell-based assay, TPNT1 can inhibit six major clades of SARS-CoV-2 with effective concentration within the range to be used as food additives. TPNT1 was shown to block viral entry by inhibiting the binding of SARS-CoV-2 spike proteins to ACE2 receptor and to interfere with the syncytium formation. In addition, TPNT1 also effectively reduced the cytopathic effects induced by human (H1N1) and avian (H5N1) influenza viruses, including the wild-type and Tamiflu-resistant virus isolates. Together with previously demonstrated efficacy as antimicrobials, TPNT1 can block viral entry and inhibit or prevent viral infection to provide prophylactic effects against both SARS-CoV-2 and opportunistic infections.

scholarly journals Nanoparticle composite TPNT1 is effective against SARS-CoV-2 and influenza viruses

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sui-Yuan Chang ◽  
Kuo-Yen Huang ◽  
Tai-Ling Chao ◽  
Han-Chieh Kao ◽  
Yu-Hao Pang ◽  
...  
Keyword(s):  
Viral Entry ◽  
Opportunistic Infections ◽  
Food Additives ◽  
Syncytium Formation ◽  
Influenza Viruses ◽  
Metal Nanoparticle ◽  
Cytopathic Effects ◽  
H5n1 Influenza ◽  
Transmission Electron

AbstractA metal nanoparticle composite, namely TPNT1, which contains Au-NP (1 ppm), Ag-NP (5 ppm), ZnO-NP (60 ppm) and ClO2 (42.5 ppm) in aqueous solution was prepared and characterized by spectroscopy, transmission electron microscopy, dynamic light scattering analysis and potentiometric titration. Based on the in vitro cell-based assay, TPNT1 inhibited six major clades of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) with effective concentration within the range to be used as food additives. TPNT1 was shown to block viral entry by inhibiting the binding of SARS-CoV-2 spike proteins to the angiotensin-converting enzyme 2 (ACE2) receptor and to interfere with the syncytium formation. In addition, TPNT1 also effectively reduced the cytopathic effects induced by human (H1N1) and avian (H5N1) influenza viruses, including the wild-type and oseltamivir-resistant virus isolates. Together with previously demonstrated efficacy as antimicrobials, TPNT1 can block viral entry and inhibit or prevent viral infection to provide prophylactic effects against both SARS-CoV-2 and opportunistic infections.

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.

Correlation Between Cellular Functions and Morphological Changes of Human Trophoblast in Vitro

1975 ◽  
Vol 33 ◽  
pp. 600-601
Author(s):  
John C. Garancis ◽  
Robert O. Hussa ◽  
Michael T. Story ◽  
Donald Yorde ◽  
Roland A. Pattillo
Keyword(s):  
Electron Microscopy ◽  
Cellular Proliferation ◽  
Morphological Changes ◽  
Culture Fluid ◽  
Cellular Functions ◽  
Human Trophoblast ◽  
Transmission Electron ◽  
Marked Activity ◽  
Malignant Trophoblast

Human malignant trophoblast cells in continuous culture were incubated for 3 days in medium containing 1 mM N6-O2'-dibutyryl cyclic adenosine 3':5'-monophosphate (dibutyryl cyclic AMP) and 1 mM theophylline. The culture fluid was replenished daily. Stimulated cultures secreted many times more chorionic gonadotropin and estrogens than did control cultures in the absence of increased cellular proliferation. Scanning electron microscopy revealed remarkable surface changes of stimulated cells. Control cells (not stimulated) were smooth or provided with varying numbers of microvilli (Fig. 1). The latter, usually, were short and thin. The surface features of stimulated cells were considerably different. There was marked increase of microvilli which appeared elongated and thick. Many cells were covered with confluent polypoid projections (Fig. 2). Transmission electron microscopy demonstrated marked activity of cytoplasmic organelles. Mitochondria were increased in number and size; some giant forms with numerous cristae were observed.

Hemolysis of erythrocytes by the hemolytic system from the blood-feeding stable fly, Stomoxys calcitrans

1992 ◽  
Vol 50 (1) ◽  
pp. 690-691
Author(s):  
H. J. Kirch ◽  
G. Spates ◽  
R. Droleskey ◽  
W.J. Kloft ◽  
J.R. DeLoach
Keyword(s):  
Blood Feeding ◽  
Stomoxys Calcitrans ◽  
Stable Fly ◽  
Digestive Physiology ◽  
Transmission Electron ◽  
Erythrocyte Lysis ◽  
Mammalian Blood ◽  
Bovine Erythrocytes ◽  
Potential Tool

Blood feeding insects have to rely on the protein content of mammalian blood to insure reproduction. A substantial quantity of protein is provided by hemoglobin present in erythrocytes. Access to hemoglobin is accomplished only via erythrocyte lysis. It has been shown that midgut homogenates from the blood feeding stable fly, Stomoxys calcitrans, contain free fatty acids and it was proposed that these detergent-like compounds play a major role as hemolysins in the digestive physiology of this species. More recently sphingomyelinase activity was detected in midgut preparations of this fly, which would provide a potential tool for the enzymatic cleavage of the erythrocyte's membrane sphingomyelin. The action of specific hemolytic factors should affect the erythrocyte's morphology. The shape of bovine erythrocytes undergoing in vitro hemolysis by crude midgut homogenates from the stable fly was examined by scanning and transmission electron microscopy.

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