Contribution of Microscopy to a Better Knowledge of the Biology ofGiardia lamblia

2004 ◽  
Vol 10 (5) ◽  
pp. 513-527 ◽  
Author(s):  
Wanderley de Souza ◽  
Adriana Lanfredi-Rangel ◽  
Loraine Campanati
Keyword(s):  
Golgi Complex ◽  
Laser Scanning ◽  
Diarrheal Disease ◽  
Freeze Fracture ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Enzyme Cytochemistry ◽  
Morphological Studies ◽  
Transmission Electron ◽  
Microscopic Techniques

Giardia lambliais a flagellated protozoan of great medical and biological importance. It is the causative agent of giardiasis, one of the most prevalent diarrheal disease both in developed and third-world countries. Morphological studies have shown thatG. lambliadoes not present structures such as peroxisomes, mitochondria, and a well-elaborated Golgi complex. In this review, special emphasis is given to the contribution made by various microscopic techniques to a better knowledge of the biology of the protozoan. The application of video microscopy, immunofluorescence confocal laser scanning microscopy, and several techniques associated with transmission electron microscopy (thin section, enzyme cytochemistry, freeze-fracture, deep-etching, fracture-flip) to the study of the cell surface, peripheral vesicles, endoplasmic reticulum–Golgi complex system, and of the encystation vesicles found in trophozoites and during the process of trophozoite-cyst transformation are discussed.

Microtubule targeted therapeutics loaded polymeric assembled nanospheres for potentiation of antineoplastic activity

2016 ◽  
Vol 186 ◽  
pp. 45-59 ◽  
Author(s):  
Radhika Poojari ◽  
Rohit Srivastava ◽  
Dulal Panda
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Laser Scanning ◽  
Present Approach ◽  
Laser Scanning Microscopy ◽  
Microtubule Assembly ◽  
Confocal Laser ◽  
Cancer Cell Proliferation ◽  
Transmission Electron ◽  
Hepatocarcinoma Cells

Polymeric nanoassemblies represent an attractive strategy for efficient cellular internalization of microtubule targeted anticancer drugs. Using dynamic light scattering, zeta potential, transmission electron microscopy and scanning electron microscopy, the physical properties and surface morphology of microtubule-binding PEGylated PLGA assembled nanospheres (100–200 nm) were analyzed. The present approach leads to strong internalization as observed by confocal laser scanning microscopy and transmission electron microscopy in hepatocarcinoma cells. The effect of these nanoassemblies on microtubules and mitosis were explored using immunofluorescence microscopy. The effects of these nanoassemblies on cancer cell proliferation and cell death revealed their antitumor enhancing effects. Perturbation of the microtubule assembly, mitosis and nuclear modulations potentiated the antineoplastic effects delivered via nanospheres in hepatocarcinoma cells. The extensive biomolecular and physical characterizations of the synthesized nanoassemblies will help to design potent therapeutic materials and the present approach can be applied to deliver microtubule-targeted drugs for liver cancer therapy.

Confocal microscopy analysis of native, full length and B-domain deleted coagulation factor VIII trafficking in mammalian cells

2004 ◽  
Vol 92 (07) ◽  
pp. 23-35 ◽  
Author(s):  
Sven Becker ◽  
Jeremy Simpson ◽  
Rainer Pepperkok ◽  
Stefan Heinz ◽  
Christian Herder ◽  
...  
Keyword(s):  
Factor Viii ◽  
Golgi Complex ◽  
Mammalian Cells ◽  
Laser Scanning ◽  
Coagulation Factor ◽  
Full Length ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Microscopy Analysis ◽  
Recombinant Fviii

SummaryIn mammalian cells, factor VIII (FVIII) secretion depends upon its interaction with chaperones of the endoplasmic reticulum (ER) and requires a unique ATP-dependent step to dissociate aggregates formed within the ER. To further elucidate mechanisms which might account for the inefficient secretion of recombinant FVIII (rFVIII), we have analyzed the pathways of recombinant full length (rFVIII-FL) and B-domain deleted (rFVIIIΔB) FVIII and compared these to the secretion route of native FVIII in primary hepatocytes. Using confocal laser scanning microscopy in combination with a pulse chase of a known secretion marker, we describe the trafficking route of FVIII, which upon release from the ER – where it colocalizes with calnexin – is transported to the Golgi complex in vesiculartubular transport complexes (VTCs) which could be further identified as being COP I coated. However, a large portion of rFVIII is retained in the ER and additionally in structures which could not be assigned to the ER, Golgi complex or intermediate compartment. Moderate BiP transcription levels indicate that this observed retention of FVIII does not reflect cellular stress due to an overexpression of FVIII-protein in transduced cells. Moreover, a pulse of newly synthesized rFVIII protein is released within 4 hrs, indicating that once rFVIII is released from the ER there is no further limitation to its secretion. Our data provide new details about the secretory route of FVIII, which may ultimately help to identify factors currently limiting the efficient and physiological expression of FVIII in gene therapy and manufacture.

scholarly journals Macropinocytosis as a Mechanism of Entry into Primary Human Urethral Epithelial Cells by Neisseria gonorrhoeae

2000 ◽  
Vol 68 (3) ◽  
pp. 1696-1699 ◽  
Author(s):  
Michael K. Zenni ◽  
Peter C. Giardina ◽  
Hillery A. Harvey ◽  
Jianqiang Shao ◽  
Margaret R. Ketterer ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Laser Scanning ◽  
Actin Polymerization ◽  
Kinase Inhibitors ◽  
Fluorescein Isothiocyanate ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Transmission Electron ◽  
Microscopy Analysis ◽  
Phosphoinositide 3 Kinase

ABSTRACT Gonococcal entry into primary human urethral epithelial cells (HUEC) can occur by macropinocytosis. Scanning and transmission electron microscopy revealed lamellipodia surrounding gonococci, and confocal laser scanning microscopy analysis showed organisms colocalized with M r 70,000 fluorescein isothiocyanate-labeled dextran within the cells. Phosphoinositide 3-kinase inhibitors and an actin polymerization inhibitor prevented macropinocytic entry of gonococci into HUEC.

Soft Tissue and Epithelial Models

1999 ◽  
Vol 13 (1) ◽  
pp. 57-66 ◽  
Author(s):  
J.A. Jansen ◽  
E.T. Den Braber ◽  
X.F. Walboomers ◽  
J.E. De Ruijter
Keyword(s):  
Laser Scanning ◽  
Analytical Techniques ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Good Tool ◽  
Oral Implants ◽  
Body Tissues ◽  
Transmission Electron ◽  
Gingival Cells

The applicability of a biomaterial for the manufacturing of oral implants is determined by its physicochemical and geometric surface properties. Research, therefore, is concerned with the cellular reactions that occur when an implant material comes into contact with body tissues. For permucosal oral implants, this involves both the reaction of bone and gingival cells. In vitro cell culturing-including the use of various analytical techniques like light microscopy, scanning and transmission electron microscopy, confocal laser scanning microscopy, and digital image analysis-is a good tool whereby investigators can obtain more insight into the relevant components of implant-tissue adhesion. In the current overview, the role of cell models in oral implant research is discussed, specifically with reference to responses of epithelial cells and fibroblasts.

scholarly journals Cyanobacterial calcification in modern microbialites at the submicrometer-scale

2013 ◽  
Vol 10 (2) ◽  
pp. 3311-3339 ◽  
Author(s):  
E. Couradeau ◽  
K. Benzerara ◽  
E. Gérard ◽  
I. Estève ◽  
D. Moreira ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Cell Morphology ◽  
Laser Scanning ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Advanced Stages

Abstract. The search for microfossils in the geological record has been a long-term challenge. Part of the problem comes from the difficulty of identifying such microfossils unambiguously, since they can be morphologically confused with abiotic biomorphs. One route to improve our ability to correctly identify microfossils consists in studying fossilization processes affecting bacteria in modern settings. We studied the initial stages of fossilization of cyanobacterial cells in modern microbialites from Lake Alchichica (Mexico), a Mg-rich hyperalkaline crater lake (pH 8.9) hosting currently growing stromatolites composed of aragonite [CaCO3] and hydromagnesite [Mg5(CO3)4(OH)2 × 4(H2O)]. Most of the biomass associated with the microbialites is composed of cyanobacteria. Scanning electron microscopy analyses coupled with confocal laser scanning microscopy observations were conducted to co-localize cyanobacterial cells and associated minerals. These observations showed that cyanobacterial cells affiliating to the order Pleurocapsales become specifically encrusted within aragonite with an apparent preservation of cell morphology. Encrustation gradients from non-encrusted to totally encrusted cells spanning distances of a few hundred micrometers were observed. Cells exhibiting increased levels of encrustation along this gradient were studied down to the nm-scale using a combination of focused ion beam (FIB) milling, transmission electron microscopy (TEM) and scanning transmission X-ray microscopy (STXM) at the C, O and N K-edges. Two different types of aragonite crystals were observed: one type was composed of needle-shaped nano-crystals growing outward from the cell body with a crystallographic orientation perpendicular to the cell wall, and another type was composed of larger crystals that progressively filled the cell interior. Organic matter (OM), initially co-localized with the cell, decreased in concentration and dispersed away from the cell while crystal growth occurred. As encrustation developed, OM progressively disappeared, but remaining OM showed the same spectroscopic signature. In the most advanced stages of fossilization, only the textural organization of the two types of aragonite recorded the initial cell morphology and spatial distribution.

Light Microscopy, Confocal Laser Scanning Microscopy And Scanning And Transmission Electron Microscopy Of Cerebellar Golgi Cells.

1999 ◽  
Vol 5 (S2) ◽  
pp. 1302-1303
Author(s):  
O. Castejόn ◽  
P Sims
Keyword(s):  
Electron Microscopy ◽  
Light Microscopy ◽  
Laser Scanning ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Synaptic Connections ◽  
Teleost Fishes ◽  
Golgi Cells ◽  
Transmission Electron ◽  
Molecular Layers

The cerebellar cortex of albino mice, hamsters, teleost fishes, primates and human have been examined by correlative microscopy to study the Golgi cell soma, dendritic processes, axonal plexus and synaptic connections in the granular and molecular layers. For light microscopy (LM) toluidinc blue stained-plastic embedded scmithin sections and Golgi light microscopy preparations were used. For confocal laser scanning microscopy (CLSM) of hamster cerebellum the FM4-64 fluorescent stain was used as intracellular tracer (1). Conventional and high resolution scanning electron microscopy (SEM) of teleost fishes, primates and human were coated with gold-palladium and chromium (2). I Transmission electron microscopy (TEM). either by ullrathin sections or frccze-clching replicas, were examined to characterize synaptic connections in the granular and molecular layers. The Golgi cells appeared in the granular layer as polygonal, stellate, round or fusiform microncurons. 10-25 μm in maximal dimension, surrounded by the granule cell groups. Golgi light microscopy.

scholarly journals Cyanobacterial calcification in modern microbialites at the submicrometer scale

2013 ◽  
Vol 10 (8) ◽  
pp. 5255-5266 ◽  
Author(s):  
E. Couradeau ◽  
K. Benzerara ◽  
E. Gérard ◽  
I. Estève ◽  
D. Moreira ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Cell Morphology ◽  
Laser Scanning ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Advanced Stages

Abstract. The search for microfossils in the geological record has been a long-term challenge. Part of the problem comes from the difficulty of identifying such microfossils unambiguously, since they can be morphologically confused with abiotic biomorphs. One route to improve our ability to correctly identify microfossils involves studying fossilization processes affecting bacteria in modern settings. We studied the initial stages of fossilization of cyanobacterial cells in modern microbialites from Lake Alchichica (Mexico), a Mg-rich hyperalkaline crater lake (pH 8.9) hosting currently growing stromatolites composed of aragonite [CaCO3] and hydromagnesite [Mg5(CO3)4(OH)2 · 4(H2O)]. Most of the biomass associated with the microbialites is composed of cyanobacteria. Scanning electron microscopy analyses coupled with confocal laser scanning microscopy observations were conducted to co-localize cyanobacterial cells and associated minerals. These observations showed that cyanobacterial cells affiliated with the order Pleurocapsales become specifically encrusted within aragonite with an apparent preservation of cell morphology. Encrustation gradients from non-encrusted to totally encrusted cells spanning distances of a few hundred micrometers were observed. Cells exhibiting increased levels of encrustation along this gradient were studied down to the nm scale using a combination of focused ion beam (FIB) milling, transmission electron microscopy (TEM) and scanning transmission x-ray microscopy (STXM) at the C, O and N K-edges. Two different types of aragonite crystals were observed: one type was composed of needle-shaped nano-crystals growing outward from the cell body with a crystallographic orientation perpendicular to the cell wall, and another type was composed of larger crystals that progressively filled the cell interior. Exopolymeric substances (EPS), initially co-localized with the cells, decreased in concentration and dispersed away from the cells while crystal growth occurred. As encrustation developed, EPS progressively disappeared, but remaining EPS showed the same spectroscopic signature. In the most advanced stages of fossilization, only the textural organization of the two types of aragonite recorded the initial cell morphology and spatial distribution.

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