scholarly journals Zones of cellular damage around pulsed-laser wounds

PLoS ONE ◽  
2021 ◽  
Vol 16 (9) ◽  
pp. e0253032
Author(s):  
James O’Connor ◽  
Fabiha Bushra Akbar ◽  
M. Shane Hutson ◽  
Andrea Page-McCaw
Keyword(s):  
Fluorescent Proteins ◽  
Pulsed Laser ◽  
Cellular Damage ◽  
Epithelial Tissue ◽  
Physical Damage ◽  
Different Types ◽  
Spatial Dependencies ◽  
Wound Signaling ◽  
Cellular Components ◽  
Wound Tissue

After a tissue is wounded, cells surrounding the wound adopt distinct wound-healing behaviors to repair the tissue. Considerable effort has been spent on understanding the signaling pathways that regulate immune and tissue-resident cells as they respond to wounds, but these signals must ultimately originate from the physical damage inflicted by the wound. Tissue wounds comprise several types of cellular damage, and recent work indicates that different types of cellular damage initiate different types of signaling. Hence to understand wound signaling, it is important to identify and localize the types of wound-induced cellular damage. Laser ablation is widely used by researchers to create reproducible, aseptic wounds in a tissue that can be live-imaged. Because laser wounding involves a combination of photochemical, photothermal and photomechanical mechanisms, each with distinct spatial dependencies, cells around a pulsed-laser wound will experience a gradient of damage. Here we exploit this gradient to create a map of wound-induced cellular damage. Using genetically-encoded fluorescent proteins, we monitor damaged cellular and sub-cellular components of epithelial cells in living Drosophila pupae in the seconds to minutes following wounding. We hypothesized that the regions of damage would be predictably arrayed around wounds of varying sizes, and subsequent analysis found that all damage radii are linearly related over a 3-fold range of wound size. Thus, around laser wounds, the distinct regions of damage can be estimated after measuring any one. This report identifies several different types of cellular damage within a wounded epithelial tissue in a living animal. By quantitatively mapping the size and placement of these different types of damage, we set the foundation for tracing wound-induced signaling back to the damage that initiates it.

scholarly journals Zones of Cellular Damage Around Pulsed-Laser Wounds

2021 ◽  
Author(s):  
James O'Connor ◽  
Fabiha Bushra Akbar ◽  
M. Shane Hutson ◽  
Andrea Page-McCaw
Keyword(s):  
Fluorescent Proteins ◽  
Pulsed Laser ◽  
Cellular Damage ◽  
Epithelial Tissue ◽  
Physical Damage ◽  
Different Types ◽  
Spatial Dependencies ◽  
Wound Signaling ◽  
Cellular Components ◽  
Wound Tissue

After a tissue is wounded, cells surrounding the wound adopt distinct wound-healing behaviors to repair the tissue. Considerable effort has been spent on understanding the signaling pathways that regulate immune and tissue-resident cells as they respond to wounds, but these signals must ultimately originate from the physical damage inflicted by the wound.  Tissue wounds comprise several types of cellular damage, and recent work indicates that different types of cellular damage initiate different types of signaling. Hence to understand wound signaling, it is important to identify and localize the types of wound-induced cellular damage. Laser ablation is widely used by researchers to create reproducible, aseptic wounds in a tissue that can be live-imaged.  Because laser wounding involves a combination of photochemical, photothermal and photomechanical mechanisms, each with distinct spatial dependencies, cells around a pulsed-laser wound will experience a gradient of damage.   Here we exploit this gradient to create a map of wound-induced cellular damage. Using genetically-encoded fluorescent proteins, we monitor damaged cellular and sub-cellular components of epithelial cells in living  Drosophila  pupae in the seconds to minutes following wounding. We hypothesized that the regions of damage would be predictably arrayed around wounds of varying sizes, and subsequent analysis found that all damage radii are linearly related o ver a 3-fold range of wound size . Thus, around laser wounds, the distinct regions of damage can be estimated after measuring any one. This report identifies several different types of cellular damage within a wounded epithelial tissue in a living animal.  By quantitatively mapping the size and placement of these different types of damage, we set the foundation for tracing wound-induced signaling back to the damage that initiates it.

Comparative Cellular Localization of Sugar Residues in Bull (Bos taurus) and Donkey (Equus asinus) Testes Using Lectin Histochemistry

2021 ◽  
pp. 1-10
Author(s):  
Mahmoud S. Gewaily ◽  
Mohamed Kassab ◽  
Asmaa Aboelnour ◽  
Essam A. Almadaly ◽  
Ahmed E. Noreldin
Keyword(s):  
Statistical Analysis ◽  
Odds Ratio ◽  
Cellular Localization ◽  
Bos Taurus ◽  
Lectin Histochemistry ◽  
Cell Type ◽  
Equus Asinus ◽  
Different Types ◽  
Cellular Components

Lectins are glycoproteins of a non-immune origin often used as histochemical reagents to study the distribution of glycoconjugates in different types of tissues. In this study, we performed a comparative cellular localization of sugar residues in bull and donkey testes using immunofluorescent lectin histochemistry. We inspected the cellular localization of the glycoconjugates within the testes using 11 biotin-labeled lectins (LCA, ConA, PNA, WGA, DBA, SBA, ECA, BPL, PTL-II, UEA-1, and PHA-E4) classified under six groups. Although the basic testicular structure in both species was similar, the cellular components showed different lectin localization patterns. The statistical analysis revealed no significant association between the intensity of labeling and different variables, including group and type of lectin and type of cell examined, at p < 0.05. However, a stronger response tended to occur in the donkey than in the bull testes (odds ratio: 1.3). These findings may be associated with the different cellular compositions of the glycoproteins and modification changes during spermatogenesis. Moreover, glycoconjugate profiling through lectin histochemistry can characterize some cell-type selective markers that will be helpful in studying bull and donkey spermatogenesis.

The influence of Pt and SrTiO3 interlayers on the microstructure of PbTiO3 thin films deposited by laser ablation on (001) MgO

1995 ◽  
Vol 10 (4) ◽  
pp. 791-794 ◽  
Author(s):  
S. Stemmer ◽  
S.K. Streiffer ◽  
W-Y. Hsu ◽  
F. Ernst ◽  
R. Raj ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Laser Ablation ◽  
Volume Fraction ◽  
Pulsed Laser ◽  
Pulsed Laser Ablation ◽  
Transmission Electron ◽  
Electrical Conductivities ◽  
Different Types ◽  
Oriented Material

We have used conventional and high-resolution transmission electron microscopy to investigate the microstruture of epitaxial, ferroelectric PbTiO3 films grown by pulsed laser ablation on (001) MgO single crystals, and on MgO covered with epitaxial Pt or SrTiO3. Pronounced variations are found in the widths and lengths of a-axis-oriented domains in these films, although the volume fraction of a-axis-oriented material varies only weakly for the different types of samples. In addition, the films deposited onto Pt-coated MgO have a larger grain size than those deposited onto bare MgO or SrTiO3/MgO. Possible reasons for the variations in the distribution of a-axis-oriented material in these samples include differences in the elastic properties and electrical conductivities of the different substrate combinations.

scholarly journals Highly Sensitive NH3 Sensors Using CVD and Epitaxial Graphene Functionalised with Vanadium(V) Oxide: A Comparative Study

Proceedings ◽  
2018 ◽  
Vol 2 (13) ◽  
pp. 854 ◽  
Author(s):  
Margus Kodu ◽  
Artjom Berholts ◽  
Tauno Kahro ◽  
Jens Eriksson ◽  
Rositsa Yakimova ◽  
...  
Keyword(s):  
Gas Sensors ◽  
Pulsed Laser ◽  
Epitaxial Graphene ◽  
Laser Deposition ◽  
Relative Response ◽  
Highly Sensitive ◽  
Different Types ◽  
Response And Recovery ◽  
Chemiresistive Gas Sensors ◽  
Speed Response

Exceptionally sensitive and selective graphene-based chemiresistive gas sensors were produced as a result of graphene functionalisation with a sub-nanometer V2O5 layer by using the method of pulsed laser deposition. Two different types of graphene were used—epitaxial graphene on SiC and CVD graphene on Si/SiO2—and both showed remarkable enhancement of sensing properties in terms of response and recovery speed, response magnitude and selectiveness towards NH3 gas. The epitaxial graphene-based sensor was demonstrating the highest relative response towards ammonia amounting to 80% for 0.1 ppm NH3.

Freezing of Cells: Role of Ice and Solutes in Cell Damage

2007 ◽  
Author(s):  
Hiroshi Takamatsu
Keyword(s):  
Mechanical Stress ◽  
Cell Damage ◽  
Cellular Damage ◽  
Elevated Concentration ◽  
Cellular Injury ◽  
Extracellular Solution ◽  
Different Types ◽  
A Cell ◽  
The Difference

The mechanism of cellular damage associated with freezing of biological cells is discussed by summarizing the author’s recent studies that consists of four different types of experiments. The “solution effects” that designate the influence of elevated concentration of electrolytes during freezing is examined first by a nonfreezing experiment that exposes cells to hypertonic solutions using a perfusion microscope. The cell damage due to the solution effect is evaluated directly from a pseudo-freezing experiment, where cells were subjected to the milieu that simulated a freeze-thaw process in the absence of ice. Contribution of ice formed in the extracellular solution is then estimated from the difference in cell survival between the pseudo-freezing experiment and a corresponding freezing experiment. The cellular injury by the mechanical stress is also examined independently by a cell deformation experiment, which mimicked the situation that cells are compressed and deformed between ice crystals. This experiment was designed to examine a complex effect of mechanical stress from ice and elevated concentration of electrolytes. Based on all these experiments, the role of concentrated solutes and ice is revealed as a function of freezing conditions.

Comparative morphometry of precompacted bovine embryos produced in vivo or in vitro after parthenogenetic activation and intracytoplasmic sperm injection (ICSI): ultrastructural analysis

Zygote ◽  
2003 ◽  
Vol 11 (3) ◽  
pp. 207-217
Author(s):  
J. Pivko ◽  
V. Landa ◽  
E. Kubovičová ◽  
A. šupová ◽  
P. Grafenau ◽  
...  
Keyword(s):  
Intracytoplasmic Sperm Injection ◽  
Volume Density ◽  
Relative Volume ◽  
Cellular Damage ◽  
Bovine Embryos ◽  
Parthenogenetic Activation ◽  
Cellular Volume ◽  
Cellular Components

Early bovine precompacted embryos (1 to 8 blastomeres) were analysed by electron microscopy. The volume density of cellular components was determined by morphometric analysis to quantify the ultrastructure of early bovine embryos produced either in vivo or in vitro both after fertilisation by intracytoplasmic sperm injection (ICSI) or from electrically stimulated oocytes (AC/DC). In normal embryos obtained in vivo (control), most of the cellular volume was occupied by cytoplasm (82.93%). The relative volume of lipids, vacuoles, mitochondria, Golgi apparatus and inclusion bodies was minimal. In the group of embryos after parthenogenetic activation (AC/DC) a relatively high proportion of the volume was occupied by vacuoles and lipids (18.68% vs 14.33%). Early ICSI-derived embryos contained the lowest relative volume of cytoplasm (58.33%) compared with the control embryos (in vivo) and parthenogenetically AC/DC-activated embryos and a higher volume was occupied by lipids (13.25%) and vacuoles (12.92%). It is concluded that in vitro produced embryos have a significantly altered ultrastructure, indicating extensive cellular damage.

scholarly journals Pulsed Laser Deposition of BaTiO3Thin Films on Different Substrates

2010 ◽  
Vol 2010 ◽  
pp. 1-5 ◽  
Author(s):  
Yaodong Yang ◽  
Zhiguang Wang ◽  
Jie-Fang Li ◽  
D. Viehland
Keyword(s):  
Thin Films ◽  
Pulsed Laser Deposition ◽  
Single Crystals ◽  
Ferroelectric Properties ◽  
Pulsed Laser ◽  
Laser Deposition ◽  
Material Systems ◽  
Different Types

We have studied the deposition of BaTiO3(BTO) thin films on various substrates. Three representative substrates were selected from different types of material systems: (i) SrTiO3single crystals as a typical oxide, (ii) Si wafers as a semiconductor, and (iii) Ni foils as a magnetostrictive metal. We have compared the ferroelectric properties of BTO thin films obtained by pulsed laser deposition on these diverse substrates.

scholarly journals Bacterial growth, communication and guided chemotaxis in 3D bioprinted hydrogel environments

2021 ◽  
Author(s):  
Julia Muller ◽  
Anna C Jakel ◽  
Jonathan Richter ◽  
Markus Eder ◽  
Elisabeth Falgenhauer ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Chemical Interaction ◽  
Fluorescent Proteins ◽  
Three Dimensional ◽  
Spatial Patterning ◽  
Generation System ◽  
Oxygen Generation ◽  
Different Types ◽  
Escherichia Coli Bacteria ◽  
Engineered Bacteria

Bioprinting of engineered bacteria is of great interest for applications of synthetic biology in the context of living biomaterials, but so far only few viable approaches are available for the printing of gels hosting live Escherichia coli bacteria. Here we develop a gentle bioprinting method based on an alginate/agarose bioink that enables precise printing of E.coli into three-dimensional hydrogel structures up to 10 mm in height. Addition of a calcium peroxide-based oxygen generation system enables maturation of fluorescent proteins deep within the printed structures. We utilize spatial patterning with the bioprinter to control different types of chemical interaction between bacteria. We first show quorum sensing-based chemical communication between engineered sender and receiver bacteria placed at different positions inside the bioprint, and then demonstrate the fabrication of barrier structures defined by non-motile bacteria that can guide the movement of chemotactic bacteria inside a gel.

scholarly journals Monitoring of Low-Intensity Exposures via Luminescent Bioassays of Different Complexity: Cells, Enzyme Reactions, and Fluorescent Proteins

2019 ◽  
Vol 20 (18) ◽  
pp. 4451 ◽  
Author(s):  
Nadezhda S. Kudryasheva ◽  
Ekaterina S. Kovel
Keyword(s):  
Bioactive Compounds ◽  
Cellular Response ◽  
Fluorescent Proteins ◽  
Statistical Processing ◽  
High Dose ◽  
Short Term ◽  
Radiation Dose Rate ◽  
Low Intensity ◽  
Proper Number ◽  
Different Types

The current paper reviews the applications of luminescence bioassays for monitoring the results of low-intensity exposures which produce a stimulative effect. The impacts of radioactivity of different types (alpha, beta, and gamma) and bioactive compounds (humic substances and fullerenols) are under consideration. Bioassays based on luminous marine bacteria, their enzymes, and fluorescent coelenteramide-containing proteins were used to compare the results of the low-intensity exposures at the cellular, biochemical, and physicochemical levels, respectively. High rates of luminescence response can provide (1) a proper number of experimental results under comparable conditions and, therefore, proper statistical processing, with this being highly important for “noisy” low-intensity exposures; and (2) non-genetic, i.e., biochemical and physicochemical mechanisms of cellular response for short-term exposures. The results of cellular exposures were discussed in terms of the hormesis concept, which implies low-dose stimulation and high-dose inhibition of physiological functions. Dependencies of the luminescence response on the exposure time or intensity (radionuclide concentration/gamma radiation dose rate, concentration of the bioactive compounds) were analyzed and compared for bioassays of different organization levels.

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