scholarly journals Anatomical and biochemical studies of Spartium junceum infected by Xylella fastidiosa subsp. multiplex ST 87

PROTOPLASMA ◽  
2021 ◽  
Author(s):  
S. Falsini ◽  
C. Tani ◽  
G. Sambuco ◽  
A. Papini ◽  
P. Faraoni ◽  
...  
Keyword(s):  
Xylella Fastidiosa ◽  
Blue Staining ◽  
Bacterial Cells ◽  
High Concentration ◽  
Toluidine Blue Staining ◽  
Outbreak Area ◽  
Phenolic Components ◽  
The Matrix ◽  
First Time ◽  
Spartium Junceum

AbstractSpartium junceum L. is a typical species of Mediterranean shrubland areas, also grown in gardens and parks as an ornamental. In recent years in Europe, S. junceum has been recurrently found to be infected by different subspecies and genotypes of the quarantine regulated bacterium Xylella fastidiosa (Xf). This work presents for the first time the anatomy of S. junceum plants that we found, by means of genetic and immunochemistry analysis, to be naturally infected by Xf subsp. multiplex ST87 (XfmST87) in Monte Argentario (Grosseto, Tuscany, Italy), a new outbreak area within the EU. Our anatomical observations showed that bacteria colonized exclusively the xylem conductive elements and moved horizontally to adjacent vessels through pits. Interestingly, a pink/violet matrix was observed with Toluidine blue staining in infected conduits indicating a high content of acidic polysaccharides. In particular, when this pink-staining matrix was observed, bacterial cells were either absent or degenerated, suggesting that the matrix was produced by the host plant as a defense response against bacterial spread. In addition, a blue-staining phenolic material was found in the vessels and, at high concentration, in the pits and inter-vessels. SEM micrographs confirmed that polysaccharide and phenolic components showed different structures, which appear to be related to two different morphologies: fibrillary and granular, respectively. Moreover, our LM observations revealed bacterial infection in xylem conductive elements of green shoots and leaves only, and not in those of other plant organs such as roots and flowers.

THIN PREPARATIONS OF HEMOPOIETIC TISSUES

1961 ◽  
Vol 39 (3) ◽  
pp. 367-372 ◽  
Author(s):  
Vibeke E. Engelbert
Keyword(s):  
Toluidine Blue ◽  
Blue Staining ◽  
Cell Nuclei ◽  
Millipore Filter ◽  
Toluidine Blue Staining ◽  
Glass Slides ◽  
Cell Layers ◽  
First Time ◽  
Millipore Filters

Previous papers dealing with behaviors and activities of blood cell nuclei have been recording mainly results with the imprint method and observations of blood cells cultured in vitro. The present paper demonstrates that the Feulgen "gentle squash" method as well as digestion with N HCl followed by toluidine blue staining at pH 4 reveals the same nuclear behaviors as the imprint method. Imprinting on millipore filters with subsequent fixation in Zenker's acetic solution followed by the Feulgen or toluidine blue staining method (the latter with or without previous N HCl digestion) is reported for the first time. The millipore imprint preserves a thicker layer of cells than imprinting on glass slides. Also cell stages which may not easily stick to glass seem to adhere well to the millipore filter. The filter imprint may in places present as many cell layers as a thin slice cut on the microtome, but without the disadvantage of having large or elongated cell stages cut into pieces by the microtome knife.

scholarly journals Intralysosomal accumulation of polyanions. I. Fusion of pinocytic and phagocytic vacuoles with secondary lysosomes.

1982 ◽  
Vol 93 (3) ◽  
pp. 866-874 ◽  
Author(s):  
M C Kielian ◽  
R M Steinman ◽  
Z A Cohn
Keyword(s):  
Dextran Sulfate ◽  
Fluid Phase ◽  
Subcellular Fractionation ◽  
Blue Staining ◽  
High Concentration ◽  
Toluidine Blue Staining ◽  
Low Concentrations ◽  
Secondary Lysosomes ◽  
Pinocytic Vesicles

The long-term exposure of macrophages to low concentrations of a number of polyanions leads to their accumulation in high concentration within secondary lysosomes. This was associated with enlargement of the lysosomes, the presence of membranous whorls, and intense toluidine blue staining of the organelles at pH 1.0. After the ingestion of a particulate load by these cells, newly formed phagocytic vacuoles failed to fuse with polyanion-laden lysosomes. The lack of fusion was evident in both fluorescence and electron micrographic studies which followed the transfer of acridine orange or Thorotrast from 2 degrees lysosomes to phagosomes. Agents that inhibited phagosome-lysosome (P-L) fusion included molecules containing high densities of sulfate, sulfonate, or carboxylate residues. Dextran sulfate (DS) in microgram/ml quantities was an excellent inhibitor, whereas nonsulfated dextran (D) was without effect at 1,000-fold higher concentrations. In contrast to their effects on P-L fusion, polyanions failed to influence the fusion of pinocytic vesicles with 2 degrees lysosomes. The uptake, intravacuolar distribution, and intralysosomal digestion of fluid-phase pinocytic markers were unaltered in lysosomes containing either D or DS. Furthermore, subcellular fractionation studies showed that the fluid-phase pinocytic marker HRP was efficiently transferred from pinosomes to large, dense 2 degrees lysosomes containing DS.

Quantitative Analysis of Tryptase- and Chymase-containing Mast Cells in Eosinophilic Conditions of Cats

2003 ◽  
Vol 40 (2) ◽  
pp. 219-221 ◽  
Author(s):  
C. Noli ◽  
M. Welle ◽  
F. Scarampella ◽  
F. Abramo
Keyword(s):  
Mast Cells ◽  
Eosinophilic Granuloma ◽  
Staining Technique ◽  
Mean Value ◽  
Blue Staining ◽  
Double Labeling ◽  
Toluidine Blue Staining ◽  
Biopsy Specimens ◽  
Superficial Dermis ◽  
First Time

The presence and density of tryptase-positive/chymase-positive mast cells (MCs) (MCTC), chymase-positive/tryptase-negative MCs (MCC), and tryptase-positive/chymase-negative MCs (MCT) in lesional skin from cats with eosinophilic conditions were investigated. Skin biopsy specimens from eight cats with eosinophilic plaque (three cats), eosinophilic granuloma (two cats), and eosinophilic dermatitis (three cats) were studied. Toluidine blue staining and a double-enzyme-immunohistochemical staining technique were performed to determine MC density and MC subtypes, respectively. MC density varied from 170.3 to 503 cells/mm2 (mean value of 314.9 cells/mm2). In the superficial dermis, 5.9% of the MC belonged to the MCT, 12.8% to the MCC, and 81.2% to the MCTC subtype. In the deep dermis, 12.8% belonged to the MCT, 12.8% to the MCC, and 73.8% to the MCTC subtype. It is the first time that MCC have been identified. The double-labeling procedure proved to be a reliable tool for identifying simultaneously the presence of MC subtypes in feline skin.

scholarly journals Novel Mechanism for Surface Layer Shedding and Regenerating in Bacteria Exposed to Metal-Contaminated Conditions

2018 ◽  
Author(s):  
Archjana Chandramohan ◽  
Elodie Duprat ◽  
Laurent Remusat ◽  
Severine Zirah ◽  
Carine Lombard ◽  
...  
Keyword(s):  
Model Organism ◽  
Heavy Metal Stress ◽  
Nucleation Site ◽  
Wall Structure ◽  
Bacterial Cells ◽  
High Concentration ◽  
Surface Layers ◽  
Ordered Structures ◽  
Self Assembling ◽  
First Time

AbstractSurface layers (S-layers) are self-assembling, ordered structures composed of repeating protein subunits found as components of the cell walls throughout the Bacteria and the Archaea. S-layers act as an interface between prokaryotic cells and their surrounding environment, and provide protection for microorganisms against diverse environmental stresses including heavy metal stress. We have previously characterized the process by which S-layers serve as a nucleation site for metal mineralization in the presence of high concentration of metals. Here, we test the hypothesis originally proposed in cyanobacteria that a “shedding” mechanism exists in prokaryotes for replacing S-layers that have become mineral-encrusted. We used a metallotolerant gram-positive bacterium bearing an S-layer,Lysinibacillussp. TchIII 20n38, as a model organism. We characterize for the first time a mechanism for resistance to metals through S-layer shedding and regeneration. S-layers nucleate the formation of Fe-mineral on the cell surface, leading to the encrustation of the S-layer. Using a combination of scanning electron microscopy (SEM) and nanoSIMS, we show that mineral-encrusted S-layers are shed by the bacterial cells, and the emerging cells regenerate new S-layers as part of their cell wall structure. This novel mechanism for the survival of prokaryotes in metal-contaminated environments may also provide elements necessary for the development of renewable systems for metal bioremediation.

Tem analysis of multiple-energy arsenic implanted and Rta'd silicon

1987 ◽  
Vol 45 ◽  
pp. 246-247
Author(s):  
R.A. Herring
Keyword(s):  
Device Fabrication ◽  
High Concentration ◽  
Tem Analysis ◽  
Defect Clusters ◽  
High Fluences ◽  
Small Defect ◽  
Before And After ◽  
The Matrix ◽  
The Difference ◽  
Factor Type

Rapid thermal annealing (RTA) of ion-implanted Si is important for device fabrication. The defect structures of 2.5, 4.0, and 6.0 MeV As-implanted silicon irradiated to fluences of 2E14, 4E14, and 6E14, respectively, have been analyzed by electron diffraction both before and after RTA at 1100°C for 10 seconds. At such high fluences and energies the implanted As ions change the Si from crystalline to amorphous. Three distinct amorphous regions emerge due to the three implantation energies used (Fig. 1). The amorphous regions are separated from each other by crystalline Si (marked L1, L2, and L3 in Fig. 1) which contains a high concentration of small defect clusters. The small defect clusters were similar to what had been determined earlier as being amorphous zones since their contrast was principally of the structure-factor type that arises due to the difference in extinction distance between the matrix and damage regions.

Antibiotics Application Strategies to Control Biofilm Formation in Pathogenic Bacteria

2020 ◽  
Vol 21 (4) ◽  
pp. 270-286 ◽  
Author(s):  
Fazlurrahman Khan ◽  
Dung T.N. Pham ◽  
Sandra F. Oloketuyi ◽  
Young-Mog Kim
Keyword(s):  
Biofilm Formation ◽  
Pathogenic Bacteria ◽  
Extracellular Polymeric Substances ◽  
Quorum Quenching ◽  
Resistance Mechanisms ◽  
Bacterial Biofilm ◽  
Bacterial Cells ◽  
High Concentration ◽  
Biofilm Inhibition ◽  
Abiotic Surfaces

Background: The establishment of a biofilm by most pathogenic bacteria has been known as one of the resistance mechanisms against antibiotics. A biofilm is a structural component where the bacterial community adheres to the biotic or abiotic surfaces by the help of Extracellular Polymeric Substances (EPS) produced by bacterial cells. The biofilm matrix possesses the ability to resist several adverse environmental factors, including the effect of antibiotics. Therefore, the resistance of bacterial biofilm-forming cells could be increased up to 1000 times than the planktonic cells, hence requiring a significantly high concentration of antibiotics for treatment. Methods: Up to the present, several methodologies employing antibiotics as an anti-biofilm, antivirulence or quorum quenching agent have been developed for biofilm inhibition and eradication of a pre-formed mature biofilm. Results: Among the anti-biofilm strategies being tested, the sub-minimal inhibitory concentration of several antibiotics either alone or in combination has been shown to inhibit biofilm formation and down-regulate the production of virulence factors. The combinatorial strategies include (1) combination of multiple antibiotics, (2) combination of antibiotics with non-antibiotic agents and (3) loading of antibiotics onto a carrier. Conclusion: The present review paper describes the role of several antibiotics as biofilm inhibitors and also the alternative strategies adopted for applications in eradicating and inhibiting the formation of biofilm by pathogenic bacteria.

scholarly journals Metabolite Differences of Polyphenols in Different Litchi Cultivars (Litchi chinensis Sonn.) Based on Extensive Targeted Metabonomics

Molecules ◽  
2021 ◽  
Vol 26 (4) ◽  
pp. 1181
Author(s):  
Nonghui Jiang ◽  
Huili Zhu ◽  
Wei Liu ◽  
Chao Fan ◽  
Feng Jin ◽  
...  
Keyword(s):  
Main Part ◽  
Ultra Performance Liquid Chromatography ◽  
Total Phenol Content ◽  
Phenol Content ◽  
Polyphenol Content ◽  
Reference Information ◽  
Phenolic Components ◽  
Early Maturing ◽  
Litchi Fruit ◽  
First Time

Litchi is an important fruit cultivated in tropical and subtropical areas with high nutritious and delicious flavor and the pulp is the main part of the fruit consumed. Previous studies found that litchi had high total phenol content and antioxidant activity, but most of them focused on the identification of single or a few phenolic components with a low throughput test, and the metabolic differences of cultivars are still unknown to a some extent. In this study we used widely targeted metabolome based on ultra-performance liquid chromatography coupled with mass spectrometry (UPLC-MS/MS) to analyze the polyphenol metabolites of five different genotypes of mature litchi fruit. A total of 126 polyphenol metabolites in eight categories were identified to reveal the composition and differences of polyphenol; 15 common differential metabolites and 20 specific differential metabolites to each cultivar were found for the first time. The results infer that flavonoids, flavonols, hydroxycinnamoyls and catechins are the main polyphenol metabolites of litchi pulp. Cluster analysis showed that there were three groups of polyphenols from high to low; early maturing Feizhixiao is a kind of high polyphenol content cultivars, especially in catechins, anthocyanins, flavonols, quinic acids and hydroxycinnamoyls. The polyphenols in the flesh of mature litchi are rich, and there are significant differences among cultivars; there was a level of correlation between the contents of phenolics and the maturity of litchi cultivars; the content of phenolics in early maturing litchi cultivars appeared higher than those of mid- to late-maturing cultivars. This experiment will provide significant reference information for cultivation, breeding, processing and consumption.

Ultrafast Toluidine Blue Staining for Rapid On-Site Evaluation of Cytological Smears

2020 ◽  
Vol 64 (4) ◽  
pp. 375-377
Author(s):  
Ekkehard Hewer ◽  
Anja M. Schmitt
Keyword(s):  
Organic Solvents ◽  
Toluidine Blue ◽  
Critical Factor ◽  
Blue Staining ◽  
Nuclear Morphology ◽  
Hazardous Chemicals ◽  
Toluidine Blue Staining ◽  
Site Evaluation ◽  
The Rose

Rapid on-site evaluation (ROSE) is one of cytopathology’s “unique selling propositions.” The quality, speed, and ease of handling of the staining used is a critical factor for the efficacy of the ROSE procedure. Here, we describe a modification of rapid toluidine blue staining that can be performed within 25 s, provides excellent nuclear morphology, and is compatible with subsequent Papanicolaou staining of the slides. Furthermore, exposure to hazardous chemicals is minimized, as no organic solvents other than the alcohol-based fixative and glycerin for temporary mounting and coverslipping are required. We have used this protocol successfully in our ROSE practice and have not observed any discrepancies between toluidine blue- and permanent Papanicolaou-stained slides.

Optimization of thermal conductivity in composites loaded with the solid-solid phase-change materials

2018 ◽  
Vol 25 (6) ◽  
pp. 1157-1165
Author(s):  
Taoufik Mnasri ◽  
Adel Abbessi ◽  
Rached Ben Younes ◽  
Atef Mazioud
Keyword(s):  
Thermal Conductivity ◽  
Phase Change ◽  
Phase Change Materials ◽  
Solid Phase ◽  
Spherical Inclusions ◽  
First Case ◽  
The Matrix ◽  
Composite Conductivity ◽  
First Time

AbstractThis work focuses on identifying the thermal conductivity of composites loaded with phase-change materials (PCMs). Three configurations are studied: (1) the PCMs are divided into identical spherical inclusions arranged in one plane, (2) the PCMs are inserted into the matrix as a plate on the level of the same plane of arrangement, and (3) the PCMs are divided into identical spherical inclusions arranged periodically in the whole matrix. The percentage PCM/matrix is fixed for all cases. A comparison among the various situations is made for the first time, thus providing a new idea on how to insert PCMs into composite matrices. The results show that the composite conductivity is the most important consideration in the first case, precisely when the arrangement plane is parallel with the flux and diagonal to the entry face. In the present work, we are interested in exploring the solid-solid PCMs. The PCM polyurethane and a wood matrix are particularly studied.

Significance of External Carbon Sources on Simultaneous Removal of Nutrients from Wastewater

1992 ◽  
Vol 26 (5-6) ◽  
pp. 1047-1055 ◽  
Author(s):  
N. F. Y. Tam ◽  
Y. S. Wong ◽  
G. Leung
Keyword(s):  
Sodium Acetate ◽  
Batch Reactor ◽  
Inorganic Nitrogen ◽  
Carbon Sources ◽  
Simultaneous Removal ◽  
Bacterial Cells ◽  
High Concentration ◽  
P Content ◽  
Carbon Substrates ◽  
Effective Source

Laboratory-scale studies were undertaken to examine the effects of easily-biodegradable organic substances upon the nutrient removal by a simulated sequencing batch reactor (SBR). The fill and react period of the SBR was 14 hours, including an instant fill, 7 hours aeration, 4 hours anoxic and 3 hours aeration period. Three kinds of commonly used carbon sources, namely methanol, glucose and sodium acetate, at the concentrations equivalent to theoretical COD values of 50, 100 and 150 mg O2 l-1 were added to each reactor prior to the anoxic stage. The results showed that the concentration of NH4+-N dropped from its initial 50 to 18 mg l-1 (64 % removal) during the first aeration period, with the NO3−-N content increased from 2 to 33 mg l−1. A 60% depletion of COD was also recorded in this period. Denitrification occurred during the anoxic period, higher amount of NO3−1-N was removed in the reactors supplemented with carbon substrates at the concentrations of 100 and 150 mg l-1. The final inorganic nitrogen content was less than 5 mg l-1 in the reactor supplemented with 150 mg l-1 sodium acetate. Simultaneous removal of phosphorus was reported in reactors supplied with high concentration of sodium acetate. In these reactors, large amount of P was released during the anoxic/anaerobic period but the released P was taken up by bacterial cells in the subsequent aeration stage, and the final P content was less than 1.5 mg l-1 (84 % removal was achieved). Among the three carbon sources used, sodium acetate was the most efficient and effective source in removing wastewater nutrients, followed by methanol, and glucose was the least reliable substrate.

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