Incremental Lines in Root Cementum of Human Teeth: An Approach to their Ultrastructural Nature by Microscopy

1997 ◽  
Vol 11 (4) ◽  
pp. 472-477 ◽  
Author(s):  
H. Renz ◽  
V. Schaefer ◽  
H. Duschner ◽  
R.J. Radlanski
Keyword(s):  
Laser Scanning ◽  
Laser Scanning Microscopy ◽  
Depth Of Field ◽  
Confocal Laser ◽  
Objective Lens ◽  
Human Teeth ◽  
Thin Sections ◽  
Surrounding Matrix ◽  
The Individual ◽  
Incremental Lines

In ground sections of human teeth, root cementum shows under the light microscope as alternating, almost concentric, dark and light rings. In paleontology and forensic medicine, the number of these incremental lines or annulations is used to derive the age-at-death of the individual. To find the ultrastructural features underlying these cemental annulations, we used bright-field light microscopy (LM), confocal laser scanning microscopy (CLSM), transmission electron microscopy (TEM), and electron-dispersive x-radiation (EDX) in a scanning electron microscope (SEM). Annulations visible in ground sections of about 100-μm thickness were no longer visible in semi-thin sections (thickness, 1-2 μm) of the same specimen in the same area. The assumption that annulations could be caused by superimposing structures in the depth of field of the light microscope's objective lens was not verified by CLSM. Fiber bundles of higher density than the surrounding matrix in TEM micrographs could not be connected unambiguously with annulations in LM micrographs. After all, the ultrastructural nature of cemental annulations remains an open question.

scholarly journals Calpurnia aurea (Aiton) Benth Extracts Reduce Quorum Sensing Controlled Virulence Factors in Pseudomonas aeruginosa

Molecules ◽  
2020 ◽  
Vol 25 (10) ◽  
pp. 2283
Author(s):  
Sekelwa Cosa ◽  
Jostina R. Rakoma ◽  
Abdullahi A. Yusuf ◽  
Thilivhali E. Tshikalange
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Molecular Docking ◽  
Quorum Sensing ◽  
Virulence Factors ◽  
Laser Scanning ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Promising Alternative ◽  
The Individual

Pseudomonas aeruginosa is the causative agent of several life-threatening human infections. Like many other pathogens, P. aeruginosa exhibits quorum sensing (QS) controlled virulence factors such as biofilm during disease progression, complicating treatment with conventional antibiotics. Thus, impeding the pathogen’s QS circuit appears as a promising alternative strategy to overcome pseudomonas infections. In the present study, Calpurnia aurea were evaluated for their antibacterial (minimum inhibitory concentrations (MIC)), anti-quorum sensing/antivirulence (AQS), and antibiofilm potential against P. aeruginosa. AQS and antivirulence (biofilm formation, swimming, and swarming motility) activities of plant extracts were evaluated against Chromobacterium violaceum and P. aeruginosa, respectively. The in vitro AQS potential of the individual compounds were validated using in silico molecular docking. Acetone and ethanolic extracts of C. aurea showed MIC at 1.56 mg/mL. The quantitative violacein inhibition (AQS) assay showed ethyl acetate extracts as the most potent at a concentration of 1 mg/mL. GCMS analysis of C. aurea revealed 17 compounds; four (pentadecanol, dimethyl terephthalate, terephthalic acid, and methyl mannose) showed potential AQS through molecular docking against the CviR protein of C. violaceum. Biofilm of P. aeruginosa was significantly inhibited by ≥60% using 1-mg/mL extract of C. aurea. Confocal laser scanning microscopy correlated the findings of crystal violet assay with the extracts significantly altering the swimming motility. C. aurea extracts reduced the virulence of pseudomonas, albeit in a strain- and extract-specific manner, showing their suitability for the identification of lead compounds with QS inhibitory potential for the control of P. aeruginosa infections.

scholarly journals The Invasion of Bacterial Biofilms into the Dentinal Tubules of Extracted Teeth Retrofilled with Fluorescently Labeled Retrograde Filling Materials

2020 ◽  
Vol 10 (19) ◽  
pp. 6996
Author(s):  
Eyal Rosen ◽  
Shlomo Elbahary ◽  
Sohad Haj-Yahya ◽  
Lotof Jammal ◽  
Hagay Shemesh ◽  
...  
Keyword(s):  
Laser Scanning ◽  
Mineral Trioxide Aggregate ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Bacterial Invasion ◽  
Human Teeth ◽  
Dentinal Tubules ◽  
Filling Materials ◽  
Retrograde Filling ◽  
Root Apices

In this study, we evaluated the invasion of bacteria into the dentinal tubules of retrofilled extracted human teeth, and the influence of different fluorescently labeled retrograde filling materials on the bacterial invasion and viability, by means of confocal laser scanning microscopy (CLSM). The root apices of extracted teeth were cut, prepared, and filled retrogradely using either intermediate restorative material (IRM), mineral trioxide aggregate (MTA), or Biodentine. The roots were filled with Enterococcus faecalis bacteria from their coronal part for 21 days. Then, 3-mm-long apical segments were cut to get root axial slices, and the bacteria were fluorescently stained and evaluated by CLSM. Bacterial penetration into the dentinal tubules favored the bucco-lingual directions. The filling materials penetrated up to 957 µm into the tubuli, and the bacteria, up to 1480 µm (means: 130 and 167 μm, respectively). Biodentine fillings penetrated less and the associated bacteria penetrated deeper into the tubuli compared to MTA or IRM (p = 0.004). Deeper filling penetration was associated with shallower penetration of both dead and live, or live alone, bacteria (p = 0.015). In conclusion, the current study enables better understanding of the microbiological–pathological course after endodontic surgical procedures. It was found that even with retrograde fillings, bacteria invade deep into the dental tubules, where deeper filling penetration prevents deeper penetration of the bacteria and adversely affects the viability of the bacteria.

scholarly journals Effectiveness of chitosan-propolis nanoparticle against Enterococcus faecalis biofilms in the root canal

2020 ◽  
Author(s):  
Abhishek Parolia ◽  
Haresh Kumar Kumar ◽  
Srinivasan Ramamurthy ◽  
Allan Pau
Keyword(s):  
Enterococcus Faecalis ◽  
Root Canal ◽  
Laser Scanning ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Internal Diameter ◽  
Group Vi ◽  
Human Teeth ◽  
Group V ◽  
Group I

Abstract Background To determine the antibacterial effect of chitosan-propolis nanoparticle (CPN) as an intracanal medicament against Enterococcus faecalis biofilm in root canal. Methods 240 extracted human teeth were sectioned to obtain 6mm of the middle third of the root. The root canal was enlarged to an internal diameter of 0.9mm. The specimens were inoculated with E. faecalis for 21 days. Following this, specimens were randomly divided into eight groups ( n=30 ) according to the intracanal medicament placed: group I: saline, groupII: chitosan, group III: propolis100 µg/ml (P100), group IV: propolis 250 µg/ml (P250), group V: chitosan-propolis nanoparticle 100µg/ml (CPN100), group VI: chitosan-propolis nanoparticle 250 µg/ml (CPN250), group VII: calcium hydroxide(CH) and group VIII: 2% chlorhexidine (CHX) gel. Dentine shavings were collected at 200 and 400 μm depths, and total numbers of CFUs were determined at the end of day one, three and seven. The non-parametric Kruskal Wallis and Mann-Whitney tests were used to compare the differences in reduction of CFUs between all groups and probability values of P < 0.05 were set as the reference for statistically significant results. The scanning electron microscope (SEM) and confocal laser scanning microscopy (CLSM) were also performed after exposure to CPNs. The effectiveness of CPNs were also evaluated against E. faecalis isolated obtained from patients having failed root canal treatment. Results Reduction in the number of colony‐forming units was statistically significant in all groups compared to saline (p <.05). On day one and three, at 200 and 400-μm, CPN250 showed significant reduction of CFUs compared to all other groups (p <.05), while CPN100 was significantly better than other groups (p <.05) except CPN250 and CHX. On day seven, at 200-μm CPN250 showed significant reduction of CFUs compared to all other groups (p <.05) except CPN100 and CHX, while at 400 μm CPN250 showed similar effectiveness as CPN100, CH and CHX. SEM and CLSM images also showed the maximum reduction of E. faecalis with CPN250. Conclusion CPN250 was the most effective in reducing E. faecalis colonies on day one, three at both depths and at day seven CPN250 was equally effective as CPN100 and CHX.

scholarly journals Fractographic classification in metallic materials by using 3D processing and computer vision techniques

2016 ◽  
Vol 25 (43) ◽  
pp. 83-96
Author(s):  
Maria Ximena Bastidas-Rodríguez ◽  
Flavio A. Prieto-Ortíz ◽  
Édgar Espejo-Mora
Keyword(s):  
Failure Analysis ◽  
Laser Scanning ◽  
Failure Modes ◽  
Confusion Matrix ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Future Research ◽  
Support Vector ◽  
3D Vision ◽  
The Individual

Failure analysis aims at collecting information about how and why a failure is produced. The first step in this process is a visual inspection on the flaw surface that will reveal the features, marks, and texture, which characterize each type of fracture. This is generally carried out by personnel with no experience that usually lack the knowledge to do it. This paper proposes a classification method for three kinds of fractures in crystalline materials: brittle, fatigue, and ductile. The method uses 3D vision, and it is expected to support failure analysis. The features used in this work were: i) Haralick’s features and ii) the fractal dimension. These features were applied to 3D images obtained from a confocal laser scanning microscopy Zeiss LSM 700. For the classification, we evaluated two classifiers: Artificial Neural Networks and Support Vector Machine. The performance evaluation was made by extracting four marginal relations from the confusion matrix: accuracy, sensitivity, specificity, and precision, plus three evaluation methods: Receiver Operating Characteristic space, the Individual Classification Success Index, and the Jaccard’s coefficient. Despite the classification percentage obtained by an expert is better than the one obtained with the algorithm, the algorithm achieves a classification percentage near or exceeding the 60 % accuracy for the analyzed failure modes. The results presented here provide a good approach to address future research on texture analysis using 3D data.

Organization of the cytoskeleton during cellularization in Drosophila melanogaster embryos: Confocal laser scanning and electron microscopy

1990 ◽  
Vol 48 (3) ◽  
pp. 462-463
Author(s):  
Kazuo Katoh ◽  
Harunori Ishikawa
Keyword(s):  
Electron Microscopy ◽  
Drosophila Melanogaster ◽  
Phosphate Buffer ◽  
Laser Scanning ◽  
Picric Acid ◽  
Egg Laying ◽  
Laser Scanning Microscopy ◽  
Confocal Laser Scanning ◽  
Confocal Laser ◽  
Thin Sections

The three-dimensional organization of cytoskeletal components in the early Drosophila melanogaster embryos during cellularization was examined by confocal laser scanning microscopy of the whole embryos and thin section electron microscopy.For confocal microscopy, Drosophila embryos at 2-3 hr after egg-laying were dechorionated and fixed with 8% paraformaldehyde-1% picric acid in 0.1M phosphate buffer (pH 7.2). Embryos were first blocked with normal goat serum, incubated with monoclonal antibody raised against Drosophila embryo α-tubulin for 4 hr, and then were incubated with FITC-conjugated anti-mouse IgG for 2 hr. Some embryos were stained with rhodamine-labeled phailoidin for F-actin visualization. After staining, the whole embryos were mounted on slide glass with an appropriate spacer and examined under the confocal microscope (Bio-Rad, Lasersharp MRC-500). For electron microscopy, dechorionated embryos were fixed with 1/2 Karnovsky's fixative followed by OsO4 fixation. To better preserve actin filaments, embryos were fixed with the same 1/2 Karnovsky's fixative containing 10 μM phailoidin and 0.1% saponin in 0.1M phosphate buffer, pH 7.2. Such fixed embryos were dehydrated and then embedded in Epoxy resin. Thin sections were cut and examined under a Hitachi H-800 type electron microscope.

scholarly journals The in vitro Efficacy of Betadine Antiseptic Solution and Colloidal Silver Gel Combination in Inhibiting the Growth of Bacterial Biofilms

2020 ◽  
Author(s):  
Phat Tran ◽  
Keaton Luth ◽  
Huy Dong ◽  
Ameesh Dev ◽  
Dilip Mehta ◽  
...  
Keyword(s):  
Laser Scanning ◽  
Wound Care ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Antiseptic Solution ◽  
Gram Positive Bacteria ◽  
Colloidal Gel ◽  
The Individual ◽  
Topical Antimicrobial

Betadine (Providone-Iodine) solution is a topically applied antiseptic, which has been used for wound care and surgery for decades for the prevention and treatment of skin and wound infections. However, several studies have documented the ineffectiveness of Betadine solution. Other topical antimicrobial dressings, including those that contain silver, have been used in the management of infected wounds. The present study was undertaken to determine if the combination of 5% Betadine solutions and silver colloidal gel (Ag-gel), is more effective than the individual materials in inhibiting the growth of both Gram negative and Gram positive bacteria. These determinations were carried out by both the colony forming unit (CFU) assay, and confocal laser scanning microscopy (CLSM). Ag-gel showed complete inhibition on all the bacteria, except Klebsiella pneumoniae CI strain while 5% Betadine concentrations did not completely kill any of the tested bacteria. However, K. pneumoniae was completely eliminated in the presence of the combination of 5% Betadine solution plus Ag-gel. Confocal laser microscopy confirmed the CFU results. Thus this study demonstrated that while the individual treatments are not effective in killing all the bacteria tested, the combination of 5% Betadine solution and Ag-gel completely kill all bacteria tested, including K. penumoniae CI.

A new route towards colloidal molecules with externally tunable interaction sites

2015 ◽  
Vol 181 ◽  
pp. 49-69 ◽  
Author(s):  
Linda K. Månsson ◽  
Jasper N. Immink ◽  
Adriana M. Mihut ◽  
Peter Schurtenberger ◽  
Jérôme J. Crassous
Keyword(s):  
Laser Scanning ◽  
Fluorescent Labeling ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Oil Droplets ◽  
Interaction Sites ◽  
Patchy Particles ◽  
The Individual ◽  
Synthesis Approach

We describe a route towards self-assembled colloidal molecules, where thermoresponsive microgels serve as discrete, externally tunable interaction sites. The ability of poly(N-isopropylacrylamide) (PNIPAM) and poly(N-isopropylmethacrylamide) (PNIPMAM) microgels to adsorb to the oil/water (O/W) interface and create Pickering-stabilized mini-emulsions was first tested using the controlled addition of sub-micron-sized polydimethylsiloxane (PDMS) oil droplets to a microgel suspension. The use of a mixture of PNIPAM and PNIPMAM microgels differing in size and fluorescent labeling then resulted in the formation of thermosensitive patchy particles, where the patches can be visualised using fluorescence confocal laser scanning microscopy. The size of the assembled decorated droplets and the number of adsorbed microgels was further reduced using an in situ synthesis approach, where the oil droplets are directly synthesised in the presence of microgels. This results in the formation of highly monodisperse microgel-decorated PDMS oil droplets with a small number of microgels adsorbed to the droplet interface. We demonstrate that we can use temperature to change the interaction potential between these interaction sites and thus trigger a reversible association of the individual decorated droplets at temperatures above the volume phase transition temperature TVPT of the microgels. Finally, we investigated the temporal evolution of the decorated droplets and found that small and well-defined clusters of microgels form in the early stages of the process primarily through the action of capillary forces. These clusters mimic colloidal molecules with a small number of discrete and thermosensitive binding sites.

In vivo Histology of the Cornea – from the “Rostock Cornea Module” to the “Rostock Electronic Slit Lamp” – a Clinical “Proof of Concept” Study

2020 ◽  
Vol 237 (12) ◽  
pp. 1442-1454
Author(s):  
Sebastian Bohn ◽  
Thomas Stahnke ◽  
Karsten Sperlich ◽  
Stephan J. Linke ◽  
Sanaz Farrokhi ◽  
...  
Keyword(s):  
Laser Scanning ◽  
Cellular Level ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Additional Information ◽  
Morphological Studies ◽  
Routine Work ◽  
Ocular Surface Diseases ◽  
The Individual

Abstract Introduction Confocal in vivo microscopy is an established method in ophthalmology research. As it requires contact coupling and calibration of the instruments is suboptimal, this method has been only rarely used in clinical routine work. As a result of close collaboration between physicists, information scientists and ophthalmologists, confocal laser scanning microscopy (CLSM) of the eye has been developed in recent years and a prototype can now be used in patients. The present study evaluates possible clinical uses of this method. Material and Methods The essential innovations in CLSM are (1) a newly designed coupling element with superficial adaptation to corneal curvature and (2) the use of a dual computerised piezo drive for rapid and precise focusing. In post-processing and after elastic imaging registration of the individual images parallel to the surface, it is also possible to produce sagittal sections resembling a split lamp and with resolution in the micrometer range. The concept was tested on enucleated pig bulbi and tested on normal volunteers and selected patients with diseases of the cornea. Results Simultaneous imaging in planes parallel to the surface and in sagittal planes provided additional information that can help us to understand the processes of wound healing in all substructures of the cornea and the role of immune competent cells. Possible clinical uses were demonstrated in a volunteer with healthy eyes and several groups of patients (keratoconus after CXL, recurrent keratitis, status after PRK). These show that this new approach can be used in morphological studies at cellular level in any desired and appropriate test plane. Conclusions It could be shown that this new concept of CLSM can be used clinically. It can provide valuable and novel information to both preclinical researchers and to ophthalmologists interested in corneal disease, e.g. density of Langerhans cells and epithelial stratification in ocular surface diseases.

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