scholarly journals MICROSCOPY TECHNIQUES ARE EFFECTIVE TOOLS FOR IMPLEMENTING STUDIES IN DAIRY SCIENCE AND TECHNOLOGY

2018 ◽  
Author(s):  
Paolo D'Incecco ◽  
Luisa Pellegrino
Keyword(s):  
Protein Interactions ◽  
Milk Fat ◽  
Laser Scanning ◽  
Biological Membrane ◽  
Immunogold Labelling ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Storage Lipids ◽  
Fat Globules ◽  
Microscopy Techniques

Milk is a complex system where lipids, proteins, sugars and salts are present in different phases, and thus shows a characteristic behaviour during either technological treatments or storage. Lipids are organized as globules, small drops of triglycerides surrounded by a biological membrane that ensures stability of their emulsion. Casein is the main milk protein and is organized as micelles containing salts and strongly hydrated. This last feature has an important effect on the micelle stability. Furthermore, micelle stability is ensured by glycosylated k-casein fragments. Interaction between fat globules and casein micelles are likely to occur since ~1010 globules e 1014 micelles are present in 1 mL of milk and their reactive surface is approximately 0.07 and 4 m2 respectively. Different milk processes, i.e. mechanic or thermal, are responsible for interactions which may vary in number and chemical nature. Microscopy techniques represent an indispensable tool to study milk microstructure during milk processing or even on finished products upon storage. Confocal laser scanning microscopy, through specific probes, is suitable to study phenomena of coalescence among fat globules and fat-protein interactions in fluid milk, gel (clotted milk) or cheese. Transmission electron microscopy and immunogold labelling are used to more deeply investigate either milk components ultrastructure or specific interactions established between the milk fat globule membrane and the casein fractions. Food products are matrices where a multidisciplinary approach is necessary for their study, and microscopy certainly plays a key role.

scholarly journals Comparative Structural and Compositional Analyses of Cow, Buffalo, Goat and Sheep Cream

Foods ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 2643
Author(s):  
Valeria D. Felice ◽  
Rebecca A. Owens ◽  
Deirdre Kennedy ◽  
Sean A. Hogan ◽  
Jonathan A. Lane
Keyword(s):  
Milk Fat ◽  
Antigen Processing ◽  
Laser Scanning ◽  
Saturated Fatty Acids ◽  
Buffalo Milk ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Milk Formula ◽  
Fat Globules ◽  
Milk Fat Globules

Factors affecting milk and milk fraction composition, such as cream, are poorly understood, with most research and human health application associated with cow cream. In this study, proteomic and lipidomic analyses were performed on cow, goat, sheep and Bubalus bubalis (from now on referred to as buffalo), bulk milk cream samples. Confocal laser scanning microscopy was used to determine the composition, including protein, lipid and their glycoconjugates, and the structure of the milk fat globules. BLAST2GO was used to annotate functional indicators of cream protein. Functional annotation of protein highlighted a broad level of similarity between species. However, investigation of specific biological process terms revealed distinct differences in antigen processing and presentation, activation, and production of molecular mediators of the immune response. Lipid analyses revealed that saturated fatty acids were lowest in sheep cream and similar in the cream of the other species. Palmitic acid was highest in cow and lowest in sheep cream. Cow and sheep milk fat globules were associated with thick patches of protein on the surface, while buffalo and goat milk fat globules were associated with larger areas of aggregated protein and significant surface adsorbed protein, respectively. This study highlights the differences between cow, goat, sheep, and buffalo milk cream, which can be used to support their potential application in functional foods such as infant milk formula.

scholarly journals Protein-Protein Interactions between Hepatitis C Virus Nonstructural Proteins

2003 ◽  
Vol 77 (9) ◽  
pp. 5401-5414 ◽  
Author(s):  
Maria Dimitrova ◽  
Isabelle Imbert ◽  
Marie Paule Kieny ◽  
Catherine Schuster
Keyword(s):  
Endoplasmic Reticulum ◽  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Protein Interactions ◽  
Laser Scanning ◽  
Ex Vivo ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Nonstructural Proteins

ABSTRACT Replication of the hepatitis C virus (HCV) genome has been proposed to take place close to the membrane of the endoplasmic reticulum in membrane-associated replicase complexes, as is the case with several other plus-strand RNA viruses, such as poliovirus and flaviviruses. The most obvious benefits of this property are the possibility of coupling functions residing in different polypeptidic chains and the sequestration of viral proteins and nucleic acids in a distinct cytoplasmic compartment with high local concentrations of viral components. Indeed, HCV nonstructural (NS) proteins were clearly colocalized in association with membranes derived from the endoplasmic reticulum. This observation, together with the demonstration of the existence of several physical interactions between HCV NS proteins, supports the idea of assembly of a highly ordered multisubunit protein complex(es) probably involved in the replication of the viral genome. The objective of this study, therefore, was to examine all potential interactions between HCV NS proteins which could result in the formation of a replication complex(es). We identified several interacting viral partners by using a glutathione S-transferase pull-down assay, by in vitro and ex vivo coimmunoprecipitation experiments in adenovirus-infected Huh-7 cells allowing the expression of HCV NS proteins, and, finally, by using the yeast two-hybrid system. In addition, by confocal laser scanning microscopy, NS proteins were clearly shown to colocalize when expressed together in Huh-7 cells. We have been able to demonstrate the existence of a complex network of interactions implicating all six NS proteins. Our observations confirm previously described associations and identify several novel homo- and heterodimerizations.

scholarly journals Morphology of Stephanella hina (Bryozoa, Phylactolaemata): common phylactolaemate and unexpected, unique characters

2020 ◽  
Vol 6 (1) ◽  
Author(s):  
Thomas F. Schwaha ◽  
Masato Hirose
Keyword(s):  
Laser Scanning ◽  
Mouth Opening ◽  
Morphological Characteristics ◽  
Sister Group ◽  
Neurosecretory Cells ◽  
Laser Scanning Microscopy ◽  
Immunocytochemical Staining ◽  
Confocal Laser ◽  
Muscle Fibres ◽  
Microscopy Techniques

Abstract Stephanella hina is a little studied freshwater bryozoan belonging to Phylactolaemata. It is currently the only representative of the family Stephanellidae, which in most reconstructions is early branching, sometimes even sister group to the remaining phylactolaemate families. The morphological and histological details of this species are entirely unknown. Consequently, the main aim of this study was to conduct a detailed morphological analysis of S. hina using histological serial sections, 3D reconstruction, immunocytochemical staining and confocal laser scanning microscopy techniques. The general morphology is reminiscent of other phylactolaemates; however, there are several, probably apomorphic, details characteristic of S. hina. The most evident difference lies in the lophophoral base, where the ganglionic horns/extensions do not follow the traverse of the lophophoral arms but bend medially inwards towards the mouth opening. Likewise, the paired forked canal does not fuse medially in the lophophoral concavity as found in all other phylactolaemates. Additional smaller differences are also found in the neuro-muscular system: the rooting of the tentacle muscle is less complex than in other phylactolaemates, the funiculus lacks longitudinal muscles, the caecum has smooth muscle fibres, latero-abfrontal tentacle nerves are not detected and the medio-frontal nerves mostly emerge directly from the circum-oral nerve ring. In the apertural area, several neurite bundles extend into the vestibular wall and probably innervate neurosecretory cells surrounding the orifice. These morphological characteristics support the distinct placement of this species in a separate family. Whether these characteristics are apomorphic or possibly shared with other phylactolaemates will require the study of the early branching Lophopodidae, which remains one of the least studied taxa to date.

The application of safranin-O for staining virus-vector trichodorid nematodes for electron and confocal laser scanning microscopy

Nematology ◽  
2000 ◽  
Vol 2 (2) ◽  
pp. 237-245 ◽  
Author(s):  
Eirini Karanastasi ◽  
Evangelos Vellios ◽  
Ian Roberts ◽  
Stuart MacFarlane ◽  
Derek J.F. Brown
Keyword(s):  
Laser Scanning ◽  
Tobacco Rattle Virus ◽  
Immunogold Labelling ◽  
Confocal Laser Scanning Microscope ◽  
Laser Scanning Microscopy ◽  
Confocal Laser Scanning ◽  
Confocal Laser ◽  
Microscopie Électronique ◽  
Safranin O ◽  
Safranine O

Abstract Post-fixation with osmium tetroxide (OsO4), prior to examination by electron microscopy, enables nematodes to be located in epoxy-resin blocks, and improves contrast of ultrastructural features. For specimen visibility, alternatives to OsO4 were examined as it can inhibit antigenicity, thus preventing application of serological techniques. Basic fuchsin stain does not affect antigenicity and when applied to trichodorids enabled specimens to be readily located in the block, but had several disadvantages such as causing substantial alteration of the nematode structure. Safranin-O stain enabled Paratrichodorus anemones and P. pachydermus specimens to be located in resin blocks, different parts of the nematode body to be distinguished, and did not affect specimen ultrastructure. Also, with viruliferous specimens it allowed immunogold labelling techniques to be applied for identifying tobacco rattle virus particles at the site of retention in the nematodes. Safranin-O is fluorescent and this feature was used to examine sections from the spicula region of a male P. pachydermus specimen under a confocal laser scanning microscope. La post-fixation au tétroxyde d’osmium (OsO4) avant l’observation en microscopie électronique empêche la localisation des nématodes dans les blocs de résine epoxy et augmente le contraste des caractéristiques ultrastructurales. Pour la localisation des spécimens, des solutions alternatives au OsO4, qui peut inhiber l’antigénicité et donc empêcher l’application de techniques sérologiques, ont été examinées. Le coloration à la fuschine basique n’affecte pas l’antigénicité et permet de situer les spécimens dans les blocs, mais elle présente de nombreux désavantages telle l’altération substantielle des structures du nématode. La safranine-O permet la localisation de Paratrichodorus anemones et de P. pachydermus, les différentes parties du corps du nématode étant alors identifiables, et n’affecte en rien l’ultrastructure du nématode. Chez les spécimens portant des virus, elle permet également l’utilisation de techniques de marquage immunologique à l’or pour identifier les particules du virus du tobacco rattle dans les sites de rétention chez le nématode. La safranine-O est fluorescente et cette particularité a été utilisée pour observer des sections de la région des spicules chez un mâle de P. pachydermus en microscopie confocale à balayage.

scholarly journals Application of Autofluorescence for Confocal Microscopy to Aid in Archaeoparasitological Analyses

2019 ◽  
Vol 57 (6) ◽  
pp. 581-585
Author(s):  
Johnica Jo Morrow ◽  
Christian Elowsky
Keyword(s):  
Electron Microscopy ◽  
Laser Scanning ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Taxonomic Identification ◽  
Molecular Analyses ◽  
Different Types ◽  
Excellent Method ◽  
Microscopy Techniques ◽  
Scanning Electron

Confocal laser scanning microscopy (CLSM) was used to examine archaeoparasitological specimens from coprolites associated with La Cueva de los Muertos Chiquitos (CMC) located near present-day Durango, Mexico. The eggs for 4 different types of parasites recovered from CMC coprolites were imaged using CLSM to assist with identification efforts. While some of the parasite eggs recovered from CMC coprolites were readily identified using standard light microscopy (LM), CLSM provided useful data for more challenging identifications by highlighting subtle morphological features and enhancing visualization of parasite egg anatomy. While other advanced microscopy techniques, such as scanning electron microscopy (SEM), may also detect cryptic identifying characters, CLSM is less destructive to the specimens. Utilizing CLSM allows for subsequent examinations, such as molecular analyses, that cannot be performed following SEM sample preparation and imaging. Furthermore, CLSM detects intrinsic autofluorescence molecules, making improved identification independent of resource and time-intensive protocols. These aspects of CLSM make it an excellent method for assisting in taxonomic identification and for acquiring more detailed images of archaeoparasitological specimens.

Hybrid Detectors Improved Time-Lapse Confocal Microscopy of PML and 53BP1 Nuclear Body Colocalization in DNA Lesions

2013 ◽  
Vol 19 (2) ◽  
pp. 360-369 ◽  
Author(s):  
Veronika Foltánková ◽  
Pavel Matula ◽  
Dmitry Sorokin ◽  
Stanislav Kozubek ◽  
Eva Bártová
Keyword(s):  
Confocal Microscopy ◽  
Protein Interactions ◽  
Laser Scanning ◽  
Nuclear Body ◽  
Dna Lesions ◽  
Nuclear Bodies ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Γ Irradiation ◽  
Pml Nuclear Bodies

AbstractWe used hybrid detectors (HyDs) to monitor the trajectories and interactions of promyelocytic leukemia (GFP-PML) nuclear bodies (NBs) and mCherry-53BP1-positive DNA lesions. 53BP1 protein accumulates in NBs that occur spontaneously in the genome or in γ-irradiation-induced foci. When we induced local DNA damage by ultraviolet irradiation, we also observed accumulation of 53BP1 proteins into discrete bodies, instead of the expected dispersed pattern. In comparison with photomultiplier tubes, which are used for standard analysis by confocal laser scanning microscopy, HyDs significantly eliminated photobleaching of GFP and mCherry fluorochromes during image acquisition. The low laser intensities used for HyD-based confocal analysis enabled us to observe NBs for the longer time periods, necessary for studies of the trajectories and interactions of PML and 53BP1 NBs. To further characterize protein interactions, we used resonance scanning and a novel bioinformatics approach to register and analyze the movements of individual PML and 53BP1 NBs. The combination of improved HyD-based confocal microscopy with a tailored bioinformatics approach enabled us to reveal damage-specific properties of PML and 53BP1 NBs.

scholarly journals Suitability of PLLA as Piezoelectric Substrates for Tissue Engineering Evidenced by Microscopy Techniques

2012 ◽  
Vol 18 (S5) ◽  
pp. 63-64 ◽  
Author(s):  
N. B. Barroca ◽  
A. L. Daniel-da-Silva ◽  
P. S. Gomes ◽  
M. H. R. Fernandes ◽  
S. Lanceros-Méndez ◽  
...  
Keyword(s):  
Laser Scanning ◽  
Bone Repair ◽  
Piezoelectric Materials ◽  
Mechanical Energy ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Biological Phenomena ◽  
Skeletal Deformation ◽  
Electrical Stimuli ◽  
Microscopy Techniques

Since the discovery of the piezoelectric character of bone, the suitability of some piezoelectric materials have been studied for bone repair; they are thought to act like transducers converting the mechanical energy of skeletal deformation in electrical stimuli capable of controlling osteogenic growth. The mechanisms underlying this process are far from being understood and systematic studies at a local scale are required. Atomic force microscopy (AFM) is a unique way to observe phenomena at the nanoscale and liquid imaging provides a unique tool to assess biological phenomena at the nanoscale. So in this study, aiming at a better understanding of the role of piezoelectricity in the osteogenic growth, the interaction between a poled piezoelectric material, in this case poly (L-lactic) acid and an adhesion promoting protein, the fibronectin, and bone-like cells is evaluated by scanning probe microscopy and confocal laser scanning microscopy (CLSM).

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