scholarly journals Choline Supplementation Sensitizes Legionella dumoffii to Galleria mellonella Apolipophorin III

2020 ◽  
Vol 21 (16) ◽  
pp. 5818
Author(s):  
Marta Palusińska-Szysz ◽  
Agnieszka Zdybicka-Barabas ◽  
Rafał Luchowski ◽  
Emilia Reszczyńska ◽  
Justyna Śmiałek ◽  
...  
Keyword(s):  
Laser Scanning ◽  
Galleria Mellonella ◽  
Cell Envelope ◽  
Laser Scanning Confocal Microscopy ◽  
Phospholipid Content ◽  
Fluorescence Lifetime Imaging ◽  
Bacterial Cells ◽  
Human Apolipoprotein ◽  
Apolipophorin Iii ◽  
Increased Susceptibility

The growth of Legionella dumoffii can be inhibited by Galleria mellonella apolipophorin III (apoLp-III) which is an insect homologue of human apolipoprotein E., and choline-cultured L. dumoffii cells are considerably more susceptible to apoLp-III than bacteria grown without choline supplementation. In the present study, the interactions of apoLp-III with intact L. dumoffii cells cultured without and with exogenous choline were analyzed to explain the basis of this difference. Fluorescently labeled apoLp-III (FITC-apoLp-III) bound more efficiently to choline-grown L. dumoffii, as revealed by laser scanning confocal microscopy. The cell envelope of these bacteria was penetrated more deeply by FITC-apoLp-III, as demonstrated by fluorescence lifetime imaging microscopy analyses. The increased susceptibility of the choline-cultured L. dumoffii to apoLp-III was also accompanied by alterations in the cell surface topography and nanomechanical properties. A detailed analysis of the interaction of apoLp-III with components of the L. dumoffii cells was carried out using both purified lipopolysaccharide (LPS) and liposomes composed of L. dumoffii phospholipids and LPS. A single micelle of L. dumoffii LPS was formed from 12 to 29 monomeric LPS molecules and one L. dumoffii LPS micelle bound two molecules of apoLp-III. ApoLp-III exhibited the strongest interactions with liposomes with incorporated LPS formed of phospholipids isolated from bacteria cultured on exogenous choline. These results indicated that the differences in the phospholipid content in the cell membrane, especially PC, and LPS affected the interactions of apoLp-III with bacterial cells and suggested that these differences contributed to the increased susceptibility of the choline-cultured L. dumoffii to G. mellonella apoLp-III.

Characterization of Deoxynivalenol Detoxification by Lactobacillus paracasei LHZ-1 Isolated from Yogurt

2019 ◽  
Vol 82 (8) ◽  
pp. 1292-1299 ◽  
Author(s):  
YAOYAO ZHAI ◽  
SHANSHAN HU ◽  
LEI ZHONG ◽  
ZHAOXIN LU ◽  
XIAOMEI BIE ◽  
...  
Keyword(s):  
Laser Scanning ◽  
Laser Scanning Confocal Microscopy ◽  
Lactobacillus Paracasei ◽  
Maximum Adsorption Capacity ◽  
Bacterial Cells ◽  
Scanning Confocal Microscopy ◽  
Binding Force ◽  
Viable Cells ◽  
And Storage

ABSTRACT Deoxynivalenol (DON) is a potent mycotoxin produced by many Fusarium spp. that invade grains during the growth and storage seasons. Lactic acid bacteria have been reported to be capable of removing several toxins, thereby providing an effective detoxification method for possible contaminated substrates. The present study mainly focused on investigating the detoxification characteristics of DON by a Lactobacillus paracasei LHZ-1 strain, which was recently isolated from yogurt with a strong promise of removing DON from liquid culture. The results obtained showed that the cell wall of L. paracasei LHZ-1 can remove up to 40.7% of 50 μg/mL DON, whereas only 10.5 and 8.9% are removed by the culture supernatant or cellular lysate, respectively. Laser scanning confocal microscopy helped to identify the mechanism of DON detoxification by L. paracasei LHZ-1 through cellular adsorption, where DON was found to bind to the surface of bacterial cells to form complexes. In stability tests, about 39 or 99% of bound DON, either to viable bacterial cells or heat-inactivated cells, respectively, was released by methanol extractions, which indicated that the binding force between viable cells and DON could be stronger than it is in heat-inactivated cells. Adsorption kinetics demonstrated that approximately 33% of DON was removed within 20 h, with a maximum adsorption capacity of approximately 50.5 μg/mL in phosphate-buffered solution.

Five-Dimensional Microscopy using Widefield-Deconvolution: Practical Considerations and Biological Applications

1996 ◽  
Vol 54 ◽  
pp. 268-269
Author(s):  
W.F. Marshall ◽  
K. Oegema ◽  
J. Nunnari ◽  
A.F. Straight ◽  
D.A. Agard ◽  
...  
Keyword(s):  
Confocal Microscopy ◽  
High Speed ◽  
Laser Scanning ◽  
Ccd Camera ◽  
Image Plane ◽  
Time Lapse ◽  
Laser Scanning Confocal Microscopy ◽  
Three Dimensions ◽  
Excitation Light ◽  
Cooled Ccd

The ability to image cells in three dimensions has brought about a revolution in biological microscopy, enabling many questions to be asked which would be inaccessible without this capability. There are currently two major methods of three dimensional microscopy: laser-scanning confocal microscopy and widefield-deconvolution microscopy. The method of widefield-deconvolution uses a cooled CCD to acquire images from a standard widefield microscope, and then computationally removes out of focus blur. Using such a scheme, it is easy to acquire time-lapse 3D images of living cells without killing them, and to do so for multiple wavelengths (using computer-controlled filter wheels). Thus, it is now not only feasible, but routine, to perform five dimensional microscopy (three spatial dimensions, plus time, plus wavelength).Widefield-deconvolution has several advantages over confocal microscopy. The two main advantages are high speed of acquisition (because there is no scanning, a single optical section is acquired at a time by using a cooled CCD camera) and the use of low excitation light levels Excitation intensity can be much lower than in a confocal microscope for three reasons: 1) longer exposures can be taken since the entire 512x512 image plane is acquired in parallel, so that dwell time is not an issue, 2) the higher quantum efficiently of a CCD detect over those typically used in confocal microscopy (although this is expected to change due to advances in confocal detector technology), and 3) because no pinhole is used to reject light, a much larger fraction of the emitted light is collected. Thus we can typically acquire images with thousands of photons per pixel using a mercury lamp, instead of a laser, for illumination. The use of low excitation light is critical for living samples, and also reduces bleaching. The high speed of widefield microscopy is also essential for time-lapse 3D microscopy, since one must acquire images quickly enough to resolve interesting events.

Laser Scanning Confocal Microscopy and Three-Dimesnsional Reconstruction of the Mitotic Spindles of Unequally Dividing Embryonic Cells

1990 ◽  
Vol 48 (3) ◽  
pp. 166-167
Author(s):  
J. Holy ◽  
G. Schatten
Keyword(s):  
Confocal Microscopy ◽  
Mitotic Spindle ◽  
Laser Scanning ◽  
Three Dimensional ◽  
Laser Scanning Confocal Microscopy ◽  
Two Dimensions ◽  
Embryonic Cells ◽  
Mitotic Spindles ◽  
Cleavage Division ◽  
Scanning Confocal Microscopy

One of the classic limitations of light microscopy has been the fact that three dimensional biological events could only be visualized in two dimensions. Recently, this shortcoming has been overcome by combining the technologies of laser scanning confocal microscopy (LSCM) and computer processing of microscopical data by volume rendering methods. We have employed these techniques to examine morphogenetic events characterizing early development of sea urchin embryos. Specifically, the fourth cleavage division was examined because it is at this point that the first morphological signs of cell differentiation appear, manifested in the production of macromeres and micromeres by unequally dividing vegetal blastomeres.The mitotic spindle within vegetal blastomeres undergoing unequal cleavage are highly polarized and develop specialized, flattened asters toward the micromere pole. In order to reconstruct the three-dimensional features of these spindles, both isolated spindles and intact, extracted embryos were fluorescently labeled with antibodies directed against either centrosomes or tubulin.

Automated 3-D cell population analysis in thick tissue sections using laser-scanning confocal-microscopy data

1993 ◽  
Vol 51 ◽  
pp. 562-563
Author(s):  
Hakan Ancin
Keyword(s):  
Laser Scanning ◽  
Population Analysis ◽  
Three Dimensional ◽  
Large Data ◽  
Laser Scanning Confocal Microscopy ◽  
Tissue Slices ◽  
Scanning Confocal Microscopy ◽  
Tissue Sections ◽  
Spatially Adaptive ◽  
Microscopy Data

This paper presents methods for performing detailed quantitative automated three dimensional (3-D) analysis of cell populations in thick tissue sections while preserving the relative 3-D locations of cells. Specifically, the method disambiguates overlapping clusters of cells, and accurately measures the volume, 3-D location, and shape parameters for each cell. Finally, the entire population of cells is analyzed to detect patterns and groupings with respect to various combinations of cell properties. All of the above is accomplished with zero subjective bias.In this method, a laser-scanning confocal light microscope (LSCM) is used to collect optical sections through the entire thickness (100 - 500μm) of fluorescently-labelled tissue slices. The acquired stack of optical slices is first subjected to axial deblurring using the expectation maximization (EM) algorithm. The resulting isotropic 3-D image is segmented using a spatially-adaptive Poisson based image segmentation algorithm with region-dependent smoothing parameters. Extracting the voxels that were labelled as "foreground" into an active voxel data structure results in a large data reduction.

scholarly journals Advanced Static and Dynamic Fluorescence Microscopy Techniques to Investigate Drug Delivery Systems

Pharmaceutics ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 861
Author(s):  
Jacopo Cardellini ◽  
Arianna Balestri ◽  
Costanza Montis ◽  
Debora Berti
Keyword(s):  
Drug Delivery ◽  
Fluorescence Microscopy ◽  
Drug Delivery Systems ◽  
Laser Scanning ◽  
Super Resolution ◽  
Laser Scanning Confocal Microscopy ◽  
Delivery Systems ◽  
Scanning Confocal Microscopy ◽  
Biological Phenomena

In the past decade(s), fluorescence microscopy and laser scanning confocal microscopy (LSCM) have been widely employed to investigate biological and biomimetic systems for pharmaceutical applications, to determine the localization of drugs in tissues or entire organisms or the extent of their cellular uptake (in vitro). However, the diffraction limit of light, which limits the resolution to hundreds of nanometers, has for long time restricted the extent and quality of information and insight achievable through these techniques. The advent of super-resolution microscopic techniques, recognized with the 2014 Nobel prize in Chemistry, revolutionized the field thanks to the possibility to achieve nanometric resolution, i.e., the typical scale length of chemical and biological phenomena. Since then, fluorescence microscopy-related techniques have acquired renewed interest for the scientific community, both from the perspective of instrument/techniques development and from the perspective of the advanced scientific applications. In this contribution we will review the application of these techniques to the field of drug delivery, discussing how the latest advancements of static and dynamic methodologies have tremendously expanded the experimental opportunities for the characterization of drug delivery systems and for the understanding of their behaviour in biologically relevant environments.

scholarly journals Optical Microscopy and the Extracellular Matrix Structure: A Review

Cells ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1760
Author(s):  
Joshua J. A. Poole ◽  
Leila B. Mostaço-Guidolin
Keyword(s):  
Extracellular Matrix ◽  
Confocal Microscopy ◽  
Laser Scanning ◽  
Biological Tissues ◽  
The Body ◽  
Stimulated Emission ◽  
Substantial Part ◽  
Fluorescence Lifetime Imaging ◽  
Structured Illumination ◽  
Structured Illumination Microscopy

Biological tissues are not uniquely composed of cells. A substantial part of their volume is extracellular space, which is primarily filled by an intricate network of macromolecules constituting the extracellular matrix (ECM). The ECM serves as the scaffolding for tissues and organs throughout the body, playing an essential role in their structural and functional integrity. Understanding the intimate interaction between the cells and their structural microenvironment is central to our understanding of the factors driving the formation of normal versus remodelled tissue, including the processes involved in chronic fibrotic diseases. The visualization of the ECM is a key factor to track such changes successfully. This review is focused on presenting several optical imaging microscopy modalities used to characterize different ECM components. In this review, we describe and provide examples of applications of a vast gamut of microscopy techniques, such as widefield fluorescence, total internal reflection fluorescence, laser scanning confocal microscopy, multipoint/slit confocal microscopy, two-photon excited fluorescence (TPEF), second and third harmonic generation (SHG, THG), coherent anti-Stokes Raman scattering (CARS), fluorescence lifetime imaging microscopy (FLIM), structured illumination microscopy (SIM), stimulated emission depletion microscopy (STED), ground-state depletion microscopy (GSD), and photoactivated localization microscopy (PALM/fPALM), as well as their main advantages, limitations.

Observation of Fine Structure in Bicontinuous Phase-Separated Domains of a Polymer Blend by Laser Scanning Confocal Microscopy

2001 ◽  
Vol 34 (15) ◽  
pp. 5186-5191 ◽  
Author(s):  
Hiroshi Jinnai ◽  
Hiroshi Yoshida ◽  
Kohtaro Kimishima ◽  
Yoshinori Funaki ◽  
Yoshitsugu Hirokawa ◽  
...  
Keyword(s):  
Fine Structure ◽  
Confocal Microscopy ◽  
Polymer Blend ◽  
Laser Scanning ◽  
Laser Scanning Confocal Microscopy ◽  
Scanning Confocal Microscopy

scholarly journals BrpA Is Involved in Regulation of Cell Envelope Stress Responses in Streptococcus mutans

2012 ◽  
Vol 78 (8) ◽  
pp. 2914-2922 ◽  
Author(s):  
J. P. Bitoun ◽  
S. Liao ◽  
X. Yao ◽  
S.-J. Ahn ◽  
R. Isoda ◽  
...  
Keyword(s):  
Streptococcus Mutans ◽  
Stress Responses ◽  
Antimicrobial Agents ◽  
Galleria Mellonella ◽  
Cell Envelope ◽  
Luciferase Reporter ◽  
Luciferase Reporter Gene ◽  
Content Type ◽  
Lipid Ii ◽  
The Impact

ABSTRACTPrevious studies have shown that BrpA plays a major role in acid and oxidative stress tolerance and biofilm formation byStreptococcus mutans. Mutant strains lacking BrpA also display increased autolysis and decreased viability, suggesting a role for BrpA in cell envelope integrity. In this study, we examined the impact of BrpA deficiency on cell envelope stresses induced by envelope-active antimicrobials. Compared to the wild-type strain UA159, the BrpA-deficient mutant (TW14D) was significantly more susceptible to antimicrobial agents, especially lipid II inhibitors. Several genes involved in peptidoglycan synthesis were identified by DNA microarray analysis as downregulated in TW14D. Luciferase reporter gene fusion assays also revealed that expression ofbrpAis regulated in response to environmental conditions and stresses induced by exposure to subinhibitory concentrations of cell envelope antimicrobials. In aGalleria mellonella(wax worm) model, BrpA deficiency was shown to diminish the virulence ofS. mutansOMZ175, which, unlikeS. mutansUA159, efficiently kills the worms. Collectively, these results suggest that BrpA plays a role in the regulation of cell envelope integrity and that deficiency of BrpA adversely affects the fitness and diminishes the virulence of OMZ175, a highly invasive strain ofS. mutans.

scholarly journals The DNA content of trophozoites and cysts of Giardia lamblia by microdensitometric quantitation of Feulgen staining and examination by laser scanning confocal microscopy.

1994 ◽  
Vol 42 (11) ◽  
pp. 1413-1416 ◽  
Author(s):  
S L Erlandsen ◽  
E M Rasch
Keyword(s):  
Confocal Microscopy ◽  
Genome Size ◽  
Dna Content ◽  
Giardia Lamblia ◽  
Laser Scanning ◽  
Laser Scanning Confocal Microscopy ◽  
Evolutionary Development ◽  
Scanning Confocal Microscopy ◽  
Dividing Cells ◽  
C Value

We investigated direct measurement of the DNA content of the parasitic intestinal flagellate Giardia lamblia through quantitation by Feulgen microspectrophotometry and also by visualization of Feulgen-stained DNA chromosomes within dividing cells by laser scanning confocal microscopy. Individual trophozoites of Giardia (binucleate) contained 0.144 +/- 0.018 pg of DNA/cell or 0.072 pg DNA/nucleus. Giardia lamblia cysts (quadranucleate) contained 0.313 +/- 0.003 pg DNA or 0.078 pg DNA/nucleus. The genome size (C) value per nucleus ranged between 6.5-7.1 x 10(7) BP for trophozoites and cysts, respectively. Confocal microscopic examination of Giardia trophozoites undergoing binary fission revealed five chromosome-like bodies within each nucleus. Further information about genome size and DNA content within different Giardia species may help to clarify the pivotal role of these primitive eukaryotic cells in evolutionary development.

The Effect of Chloroquine on the Apoptosis Induced by Cisplatin in Human Gastric Cancer BGC823 Cells

2014 ◽  
Vol 926-930 ◽  
pp. 1124-1127
Author(s):  
Zhen Xun Jin ◽  
Li Li Zhang ◽  
Yan Wang ◽  
Lin Chuan Zeng ◽  
Yang Yu ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
Confocal Microscopy ◽  
Laser Scanning ◽  
Laser Scanning Confocal Microscopy ◽  
Combination Group ◽  
Human Gastric Cancer ◽  
Apoptotic Cells ◽  
Toxic Dose ◽  
Scanning Confocal Microscopy ◽  
Mtt Tests

The aim of this study is to investigate the effects and mechanism of chloroquine (CQ) on the apoptosis induced by cisplatin in human gastric cancer BGC823 cells. MTT assay was used to detect the state of cell growth. The appearances of cellular apoptosis were detected by laser scanning confocal microscopy and light microscopy. The expressions of LC3 and p62 were detected by laser scanning confocal microscopy. MTT tests showed that the non-toxic dose of CQ could increase the inhibition rate of BGC823 cells induced by cisplatin. Under the light microscope, the ratio of apoptotic cells in the group treated with non-toxic dose of CQ combined with cisplatin was higher than that in the group treated with cisplatin alone. Hoechst33342 staining showed that the ratio of apoptotic cells in the combination group was higher than that in the cisplatin group. The expression and colocalization of LC3 and p62 proteins were significantly increased in the combination group. These results indicate that CQ can enhance the cell apoptosis induced by cisplatin in BGC823 cells, which is through the inhibition of autophagy.

Sign in / Sign up

Export Citation Format

Share Document