Ex-Vivo evaluation of Nano-MgO in the elimination of Endodontic pathogen- E. faecalis

Magnesium oxide (MgO) nanoparticles due to their antimicrobial properties and ability to survive under harsh conditions have become an area of interest in the field of biomedical sciences. The aim of the study was to evaluate antimicrobial efficacy of Nano-MgO in the elimination of endodontic pathogen . Minimum inhibitory concentration (MIC) of Nano-MgO and sodium hypochlorite against was calculated using broth dilution method. The antibacterial efficacy of Nano-MgO in elimination of the pathogens was seen using an ex-vivo model of decoronated teeth which were experimentally infected. The antibiofilm activity of the tested antimicrobial agents on biofilms was determined quantitatively by counting the colonies on Mueller-Hinton agar plates and by evaluation under scanning electron microscopy (SEM). The data analysis was done using one way ANOVA and the intergroup comparison by student –t test. MIC concentration of Nano-MgO was observed at 10mg/ml for . Mean values of colony forming unit (CFU) count was maximum for normal saline, followed by Nano-MgO and sodium hypochlorite with a significant difference between all the three groups. The results of the study reveal that Nano-MgO has the potential to be used as an alternative irrigating solution in endodontic therapy.

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Comparison of Extracapsular Stabilization Techniques Using an Ultrasonically Implanted Absorbable Bone Anchor (Weldix) after Cranial Cruciate Ligament Rupture in Cats—An In Vitro Study

Animals ◽

10.3390/ani11061695 ◽

2021 ◽

Vol 11 (6) ◽

pp. 1695

Author(s):

Lydia Koch ◽

Barbara Bockstahler ◽

Alexander Tichy ◽

Christian Peham ◽

Eva Schnabl-Feichter

Keyword(s):

Internal Rotation ◽

Ex Vivo ◽

Cruciate Ligament ◽

Joint Stability ◽

Bone Anchor ◽

Ex Vivo Model ◽

Cranial Cruciate Ligament ◽

Stifle Joint ◽

Significant Difference

Background: This study evaluated joint stability after surgical repair of cranial cruciate ligament (CrCL)-deficient stifle joints in cats using a novel absorbable polylactide bone anchor in an ex vivo model. Methods: Thirty-six hindlimbs from cats with intact (Gi group) and transected CrCLs were treated with fabellotibial suture alone (GFW group), suture combined with an absorbable polylactide bone anchor (GWD group), or suture combined with a nonabsorbable bone anchor (GFT group), positioned in a limb press with predefined joint angles (stifle joint: 120 ± 5°; hock joint: 120 ± 5°) and loaded with 10%, 20%, and 30% of body mass (BM). Predefined points were measured on lateral radiographs and with a coordinate measurement machine. Distances on radiographs (mm) were measured and angles (°) were calculated to represent the craniocaudal movement and the internal rotation of the tibia. Results: There were no differences for craniocaudal movement between Gi and GFW or GFT, but for GWD regarding angle measurement at 30% BM. For internal rotation, there was no significant difference between Gi and GFW or GWD, but for GFT. Conclusion: The used absorbable polylactide bone-anchor was able to stabilize the stifle joint regarding internal rotation and craniocaudal movement as calculated from distance measurements.

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Assessing acute and chronic Staphylococcus aureus growth and virulence in an ex vivo model of cystic fibrosis lung infection

Access Microbiology ◽

10.1099/acmi.ac2020.po0178 ◽

2020 ◽

Vol 2 (7A) ◽

Author(s):

Branagh Crealock-Ashurst ◽

Freya Harrison ◽

Esther Sweeney

Keyword(s):

Cystic Fibrosis ◽

Staphylococcus Aureus ◽

Ex Vivo ◽

Bacterial Load ◽

Clinical Results ◽

Lung Model ◽

Clinical State ◽

Ex Vivo Model ◽

Significant Difference ◽

Factor Assay

Staphylococcus aureus is routinely found in sputum samples obtained from people with Cystic Fibrosis (CF). However, its role in the progression of the disease is unclear. This is important, as antibiotic clearance of S. aureus in CF yields unclear clinical results and there is debate around the utility of anti-Staphylococcal antibiotic treatment. We used an ex vivo porcine lung model (EVPL) to compare the growth and virulence of S. aureus isolates from acute CF exacerbations, with isolates from the same donors when they were stable. There was no significant difference in mean bacterial load between donors, strains or clinical state. However, when we compared the variance in bacterial load of each pair of exacerbation/stable isolates across experimental replicates of the lung model, we found that stable samples grew more consistently in the EVPL compared to those taken from the same donor during an exacerbation. Virulence factor assay results were mixed, with results implying greater virulence in either stable or acute samples after passage through the EVPL. We could not detect the AIP quorum sensing signal, which control expression of numerous acute virulence factors, using a reporter assay. We hypothesise that S. aureus might down-regulate Agr expression in the model, consistent with a role as a silent persister, rather than as a pathogenic agent. Further work using the EVPL model will determine how well this reflects the clinical reality in CF.

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Resistance Index of Penicillin-Resistant Bacteria to Various Physicochemical Agents

ISRN Microbiology ◽

10.5402/2012/789474 ◽

2012 ◽

Vol 2012 ◽

pp. 1-6

Author(s):

M. Kazemi ◽

R. Kasra Kermanshahi ◽

E. Heshmat Dehkordi ◽

F. Payami ◽

M. Behjati

Keyword(s):

Bacterial Resistance ◽

Antimicrobial Agents ◽

Resistance Index ◽

Resistance Pattern ◽

Resistant Bacteria ◽

Dilution Method ◽

Published Data ◽

Bacterial Strains ◽

Significant Difference ◽

The Impact

Widespread use of various antimicrobial agents resulted in the emergence of bacterial resistance. Mechanisms like direct efflux, formation, and sequestration of metals and drugs in complexes and antiporter pumps are some examples. This investigation aims to investigate the resistance pattern of penicillin-resistant bacterial strains to some physicochemical agents. Sensitivity/resistance pattern of common bacterial strains to antimicrobial agents were evaluated by disk diffusion assay. Broth and agar dilution method were used for determination of minimum inhibitory concentration and minimal bactericidal concentration. The impact of UV ray on the bacterial growth under laminar flow hood was measured using photonmeter. Our data demonstrates that the most prevalent metal resistance was against arsenate (95.92%), followed by cadmium (52.04%) and mercury (36.73%). There was significant difference between cetrimide resistances among studied microbial strains especially for P. aeruginosa (). High rate of pathogen resistance to various antibacterial agents in our study supports previously published data. This great rate of bacterial resistance is attributed to the emergence of defense mechanisms developed in pathogens. The higher general bacterial resistance rate among Staphylococcus strains rather than E. coli and P. aeruginosa strains draws attention towards focusing on designing newer therapeutic compounds for Staphylococcus strains.

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Determining a Critical Threshold for G6PD Activity below which RBC Response to Oxidative Stress is Poor

10.21203/rs.2.19598/v2 ◽

2020 ◽

Author(s):

Maria Swastika ◽

Alida R Harahap ◽

Lydia V Panggalo ◽

Sri Widia A Jusman ◽

Ari W Satyagraha

Keyword(s):

Oxidative Stress ◽

G6pd Deficiency ◽

Ex Vivo ◽

Strong Association ◽

G6pd Activity ◽

Critical Threshold ◽

Main Function ◽

Ex Vivo Model ◽

Comparison Results ◽

Significant Difference

Abstract Background: Glucose-6-phosphate dehydrogenase (G6PD) deficiency is the most common enzyme disorder in the world. Its main function is to generate NADPH that is required for anti-oxidative pathway in the cells especially in RBC. G6PD deficiency is X-linked and thus subject to random X-chromosome inactivation in women giving them mosaic expression of G6PD activities in their individual cells. This phenomenon makes it difficult for diagnosis with the currently available G6PD qualitative diagnostic tests. With the rolling out of newly marketed anti-malarial drug tafenoquine which has a long half-life, screening for G6PD deficiency becomes a necessity where those with <70% G6PD activity cannot receive this drug. Thus, evidence for a quantitative cut-off for G6PD activity is needed to ensure safe drug administration. Methods: RBC models were developed to analyze the effect of oxidant on RBC oxidative markers namely total glutathione (GSH) and malondialdehyde (MDA). G6PD activity was measured using quantitative assay from Trinity Biotech and was correlated with cytofluorometric assay. RBC from two G6PD heterozygous women with different G6PD activities were also analyzed for comparison. Results: There was a negative correlation between G6PD activity and CuCl concentration and a strong association between G6PD activities and proportion of G6PD normal RBC in CuCl-treated models and in ex vivo RBC. However, in terms of oxidative stress markers analyses, unlike the hypothesis where the lower G6PD activity, the higher MDA and the lower GSH level, our CuCl RBC model showed that in low G6PD activities (10-30%) cells, the MDA level is lower compared to the rest of the models (p<0.05). Our ex vivo model however were in line with the hypothesis, although the result was not significant (p=0.5). There was a significant difference between RBC with <60% and those with >80% G6PD activities in CuCl RBC model but not in ex vivo RBC (p=0.5). Genotyping heterozygous subjects showed G6PD Viangchan variant with 2.97 U/gHb (33% activity) and 6.58 U/gHb (74% activity). Conclusions: The GSH analysis has pointed to the 60% G6PD activity cut-off and this data is supportive of the old WHO threshold for intermediate upper limit of 60% G6PD activity. However, there are significant limitations in using MDA assay with CuCl RBC model because the RBC was already stressed due to the copper treatment and thus present a different result when compared to the ex-vivo model.

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Ex Vivo Analysis of MTA FLOW® Biomineralization and Push-Out Strength: A Pilot Study

Odovtos - International Journal of Dental Sciences ◽

10.15517/ijds.2020.41780 ◽

2020 ◽

pp. 245-259

Author(s):

Marianella Benavides García ◽

Erick Hernández Meza ◽

Jessie Reyes-Carmona

Keyword(s):

Pilot Study ◽

Calcium Ions ◽

Bonding Strength ◽

Ex Vivo ◽

Carbonate Apatite ◽

Ex Vivo Model ◽

Biomineralization Process ◽

Significant Difference ◽

Phosphate Buffered Saline ◽

Push Out

This study evaluated the biomineralization processes and push-out strength of MTA Flow® with radicular dentine in three different consistencies. The push-out test was performed on an ex vivo model, using 2mm thick dentin discs from the middle third of the root with standardized cavities of 1.5 mm. Samples were filled with MTA-Angelus (Angelus Dental, Brazil), Biodentine (Septodont, France), MTA Flow® Putty (Ultradent, USA), MTA Flow® Thick or MTA Flow® Thin. The samples were divided into 3 groups: subgroup 1 (n=5), analysis of the biomineralization process; 2 (n=20), evaluation of the bonding strength and push-out resistance; and 3 (n=5), evaluation of the cement/dentin interface. The samples filled with Biodentine had a higher precipitation of carbonate apatite. However, there was no significant difference between MTA-Angelus, MTA Flow® Putty, or Thick (p=0.0536), but there was a significant difference in the Thin group (P<0.05). The samples with Biodentine displayed the greatest release of calcium ions. The formation of a partially carbonated intermediate apatite layer was observed in all groups. Zones of biomineralization were observed at the interface but were not continuous. After 72 hours, a significant difference was found between the Biodentine and MTA Flow® Thin groups (p=0.0090) in the push-out test. The samples submerged in phosphate-buffered saline (PBS) for 15 days showed a significant difference between all groups and MTA Flow® Thin (p=0.0147). Putty or Thick consistencies presented a similar bonding strength to MTA-Angelus and Biodentine. MTA Flow® Putty and Thick consistencies show a good adaptation to dentin, similar to MTA-Angelus. However, the thickness of the interface was lower compared to that of Biodentine. MTA Flow® Thin, despite their tubular infiltration, results in gaps and a defective peripheral seal. Therefore, MTA Flow®, in Putty or Thick consistencies, presents a biomineralization process and push-out strength similar to MTA Angelus and Biodentine, however, both characteristics decreases considerably in Thin consistency.

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Determining Quantitative Diagnostic Test Cut-off in G6PD Heterozygous Women for Tafenoquine Therapy

10.21203/rs.2.19598/v1 ◽

2019 ◽

Author(s):

Maria Swastika ◽

Alida R Harahap ◽

Lydia V Panggalo ◽

Sri Widia A Jusman ◽

Ari W Satyagraha

Keyword(s):

G6pd Deficiency ◽

Ex Vivo ◽

Strong Association ◽

G6pd Activity ◽

Main Function ◽

Ex Vivo Model ◽

Stress Markers ◽

Oxidative Markers ◽

Significant Difference ◽

Glucose 6 Phosphate Dehydrogenase

Abstract Background Glucose-6-phosphate dehydrogenase (G6PD) deficiency is the most common enzyme disorder in the world. Its main function is to generate NADPH that is required for anti-oxidative pathway in the cells especially in red blood cells (RBC). G6PD deficiency is X-linked and thus subject to random X-chromosome inactivation in women giving them mosaic expression of G6PD activities in their individual cells. This phenomenon makes it difficult for diagnosis with the currently available G6PD qualitative diagnostic tests. With the rolling out of newly marketed anti-malarial drug tafenoquine which has a long half-life, screening for G6PD deficiency becomes a necessity where those with <70% G6PD activity cannot receive this drug. Thus, evidence for a quantitative cut-off for G6PD activity is needed to ensure safe drug administration.Methods RBC models were developed to analyze the effect of oxidant on RBC oxidative markers namely total glutathione (GSH) and malondialdehyde (MDA). G6PD activity was measured using quantitative assay from Trinity Biotech and was correlated with cytofluorometric assay. RBC from G6PD heterozygous women with different G6PD activities were also analyzed for comparison.Results There was a negative correlation between G6PD activity and CuCl concentration and a strong association between G6PD activities and proportion of G6PD normal RBC in CuCl-treated models and in ex vivo RBC. However, in terms of oxidative stress markers analyses, unlike the hypothesis where the lower G6PD activity, the higher MDA and the lower GSH level, our CuCl RBC model showed that in low G6PD activities (10-30%) cells, the MDA level is lower compared to the rest of the models (p<0.05). Our ex vivo model however were in line with the hypothesis, although the result was not significant (p=0.5). There was a significant difference between RBC with <60% and those with >80% G6PD activities in CuCl RBC model but not in ex vivo RBC (p=0.5). Genotyping heterozygous subjects showed G6PD Viangchan variant with 2.97 U/g Hb (33% activity) and 6.58 U/g Hb (74% activity).Conclusions The MDA and GSH analyses have pointed to the 60% G6PD activity cut-off. This provides an evidence of possible cut-off for tafenoquine administration in G6PD heterozygous women.

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Indigenous Knowledge Affords Antimicrobial Plants for the Management of Infections

International Journal of TROPICAL DISEASE & Health ◽

10.9734/ijtdh/2021/v42i330441 ◽

2021 ◽

pp. 12-21

Author(s):

John Alake ◽

Samuel A. Akwetey ◽

Wisdom Ahlidja ◽

Francis A. Armah ◽

Isaac Kingsley Amponsah

Keyword(s):

Ethyl Acetate ◽

Antimicrobial Agents ◽

Antimicrobial Effect ◽

Antimicrobial Activities ◽

Diffusion Method ◽

Dilution Method ◽

Biomedical Sciences ◽

Cape Coast ◽

Disk Diffusion Method ◽

Plant Materials

Aim: The research was carried out to ascertain the antimicrobial effect of the plants Omphalocarpum ahia, Homalium letestui, and Coelocaryon oxycarpum, which are used locally to treat some infectious diseases. Place and Duration of Study: Department of Biomedical Sciences, School of Allied Health Sciences, University of Cape Coast, Cape Coast, Ghana and Department of Herbal Medicine, KNUST, Ghana from June to August 2014. Method: The stem barks of the plants were extracted with 70 % methanol and successively partitioned with petroleum ether, ethyl acetate, methanol to obtain three different fractions. The antimicrobial activities of the extracts and fraction against MRSA, S. typhi, E. coli, S. pneumoniae, P. aeruginosa, E. faecalis, and S. aureus were determined using the disk diffusion method and the minimum inhibition concentration by the serial microplate dilution method with 0.2 mg/ml p-iodonitrotetrazolium as growth indicator whereas gentamycin was used as the positive control. Phytochemical tests on the plant materials were done according to standard methods. Result: All the fractions of each plant had activity against some of the bacteria. Ethyl acetate (EA) and hydro-methanolic (CE) extracts of Coelocaryon oxycarpum exhibited activity against all selected bacteria with MIC ranging from 0.625-5 mg/ml for CE and 0.3125-5 mg/ml for EA. Hydro-methanolic (CE) extracts of Omphalocarpum ahia also exhibited antibacterial activity against all the selected bacteria. Conclusion: The current research showed that Omphalocarpum ahia and Coelocaryon oxycarpum have considerable antimicrobial activity against all the strains used in the study. Local knowledge may afford lead materials for the development of novel antimicrobial agents.

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