scholarly journals Post-operative fracture risk assessment following tumor curettage in the distal femur: a hybrid in vitro and in silico biomechanical approach

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Azadeh Ghouchani ◽  
Gholamreza Rouhi ◽  
Mohammad Hosein Ebrahimzadeh
Keyword(s):  
Fracture Risk ◽  
Bone Cement ◽  
Bone Strength ◽  
In Silico ◽  
Distal Femur ◽  
In Vitro Tests ◽  
Cement Interface ◽  
Medial Side ◽  
Significant Difference

AbstractThe distal femur is the predominant site for benign bone tumours and a common site for fracture following tumour removal or cementation. However, the lack of conclusive assessment criterion for post-operative fracture risk and appropriate devices for cement augmentation are serious concerns. Hence, a validated biomechanical tool was developed to assess bone strength, depending on the size and location of artificially created tumorous defects in the distal femora. The mechanics of the bone–cement interface was investigated to determine the main causes of reconstruction failure. Based on quantitative-CT images, non-linear and heterogeneous finite element (FE) models of human cadaveric distal femora with simulated tumourous defects were created and validated using in vitro mechanical tests from 14 cadaveric samples. Statistical analyses demonstrated a strong linear relationship (R2 = 0.95, slope = 1.12) with no significant difference between bone strengths predicted by in silico analyses and in vitro tests (P = 0.174). FE analyses showed little reduction in bone strength until the defect was 35% or more of epiphyseal volume, and reduction in bone strength was less pronounced for laterally located defects than medial side defects. Moreover, the proximal end of the cortical window and the most interior wall of the bone–cement interface were the most vulnerable sites for reconstruction failure.

Prediction of fracture risk of a distal femur reconstructed with bone cement: QCSRA, FEA, and in-vitro cadaver tests

2020 ◽  
Vol 43 (1) ◽  
pp. 269-277 ◽  
Author(s):  
Hoda Mosleh ◽  
Gholamreza Rouhi ◽  
Azadeh Ghouchani ◽  
Nima Bagheri
Keyword(s):  
Fracture Risk ◽  
Bone Cement ◽  
Distal Femur

Computational and In-Vitro Validation of Natural Molecules as Potential Acetylcholinesterase Inhibitors and Neuroprotective Agents

2019 ◽  
Vol 16 (2) ◽  
pp. 116-127 ◽  
Author(s):  
Ashwani Kumar ◽  
Vineet Mehta ◽  
Utkarsh Raj ◽  
Pritish Kumar Varadwaj ◽  
Malairaman Udayabanu ◽  
...  
Keyword(s):  
In Silico ◽  
Hippocampal Neurons ◽  
Symptomatic Relief ◽  
In Vitro Assays ◽  
Disease Modifying Drugs ◽  
In Silico Docking ◽  
Ache Inhibitors ◽  
Significant Difference ◽  
Disease Modifying

Background: Cholinesterase inhibitors are the first line of therapy for the management of Alzheimer’s disease (AD), however, it is now established that they provide only temporary and symptomatic relief, besides, having several inherited side-effects. Therefore, an alternative drug discovery method is used to identify new and safer ‘disease-modifying drugs’. Methods: Herein, we screened 646 small molecules of natural origin having reported pharmacological and functional values through in-silico docking studies to predict safer neuromodulatory molecules with potential to modulate acetylcholine metabolism. Further, the potential of the predicted molecules to inhibit acetylcholinesterase (AChE) activity and their ability to protect neurons from degeneration was determined through in-vitro assays. Results: Based on in-silico AChE interaction studies, we predicted quercetin, caffeine, ascorbic acid and gallic acid to be potential AChE inhibitors. We confirmed the AChE inhibitory potential of these molecules through in-vitro AChE inhibition assay and compared results with donepezil and begacestat. Herbal molecules significantly inhibited enzyme activity and inhibition for quercetin and caffeine did not show any significant difference from donepezil. Further, the tested molecules did not show any neurotoxicity against primary (E18) hippocampal neurons. We observed that quercetin and caffeine significantly improved neuronal survival and efficiently protected hippocampal neurons from HgCl2 induced neurodegeneration, which other molecules, including donepezil and begacestat, failed to do. Conclusion: Quercetin and caffeine have the potential as “disease-modifying drugs” and may find application in the management of neurological disorders such as AD.

scholarly journals Predicting the bactericidal efficacy of solar disinfection (SODIS): from kinetic modeling of in vitro tests towards the in silico forecast of E. coli inactivation

2021 ◽  
pp. 130866
Author(s):  
Sofia Samoili ◽  
Giulio Farinelli ◽  
José Ángel Moreno-SanSegundo ◽  
Kevin G. McGuigan ◽  
Javier Marugán ◽  
...  
Keyword(s):  
Kinetic Modeling ◽  
In Silico ◽  
In Vitro Tests ◽  
Solar Disinfection ◽  
E Coli ◽  
Bactericidal Efficacy

scholarly journals An Integrated Decision-tree Testing Strategy for Repeat Dose Toxicity with Respect to the Requirements of the EU REACH Legislation

2008 ◽  
Vol 36 (1) ◽  
pp. 93-101 ◽  
Author(s):  
Christina Grindon ◽  
Robert Combes ◽  
Mark T.D. Cronin ◽  
David W. Roberts ◽  
John F. Garrod
Keyword(s):  
In Silico ◽  
New Technologies ◽  
In Vivo Studies ◽  
In Vitro Tests ◽  
Repeat Dose ◽  
The European Union ◽  
Testing Strategy ◽  
Repeat Dose Toxicity ◽  
Joint Research Project

This paper presents some results of a joint research project conducted by FRAME and Liverpool John Moores University, and sponsored by Defra, on the status of alternatives to animal testing with regard to the European Union REACH (Registration, Evaluation and Authorisation of Chemicals) system for the safety testing and risk assessment of chemicals. The project covered all the main toxicity end-points associated with REACH. This paper focuses on the use of alternative (non-animal) methods (both in vitro and in silico) for repeat dose (sub-acute, sub-chronic and chronic) toxicity testing. It reviews the limited number of in silico and in vitro tests available for this endpoint, and outlines new technologies which could be used in the future, e.g. the use of biomarkers and the ‘omics’ technologies. An integrated testing strategy is proposed, which makes use of as much non-animal data as possible, before any essential in vivo studies are performed. Although none of the non-animal tests are currently undergoing validation, their results could help to reduce the number of animals required for testing for repeat dose toxicity.

scholarly journals Acute Effects of Three Cooked Non-Cereal Starchy Foods on Postprandial Glycemic Responses and in Vitro Carbohydrate Digestion in Comparison with Whole Grains: A Randomized Trial

Nutrients ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 634 ◽  
Author(s):  
Ruixin Zhu ◽  
Zhihong Fan ◽  
Yue Han ◽  
Shuang Li ◽  
Guojing Li ◽  
...  
Keyword(s):  
Northeast Asia ◽  
Whole Grains ◽  
In Vitro Tests ◽  
Acute Effects ◽  
Significant Difference ◽  
Starchy Foods ◽  
Carbohydrate Digestion ◽  
Glycemic Management ◽  
Low Glycemic Index

Plant origin, processing, and domestic preparation may affect the postprandial glycemic response (PGR) of starchy foods. The objective of this study was to examine the possibility of integrating domestically cooked non-cereal starchy foods commonly consumed in Northeast Asia into glycemic management diet, and compare their glycemic characteristics with those of waxy and non-waxy whole grains and starchy beans. In a randomized crossover trial, ten healthy subjects consumed dried lily bulb (LB), lotus seed (LS), adlay (AD), waxy black rice (BR), millet (MI), and adzuki bean (AB), pre-soaked and each cooked for two time durations. Acute PGR tests and in vitro carbohydrate digestion were carried out for each test food. Both the LS and AB meals achieved low glycemic index (GI 21–51), while the other starchy foods failed to show significant difference with rice (GI 83–109). The hydrolysis indexes of LS and AB were 37.7%–61.1%, significantly lower than other test foods. The in vitro tests indicated that pre-soaking resulted in high rapidly digestible starch (RDS) and low resistant starch (RS). Careful choice of whole grain materials, minimized pre-soaking, and moderate cooking may be critical factors for successful postprandial glycemic management for diabetic and pre-diabetic.

scholarly journals Osseointegration of Antimicrobial Acrylic Bone Cements Modified with Graphene Oxide and Chitosan

2020 ◽  
Vol 10 (18) ◽  
pp. 6528 ◽  
Author(s):  
Mayra Eliana Valencia Zapata ◽  
José Herminsul Mina Hernandez ◽  
Carlos David Grande Tovar ◽  
Carlos Humberto Valencia Llano ◽  
Blanca Vázquez-Lasa ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Bone Cement ◽  
Orthopedic Surgery ◽  
Bending Strength ◽  
Orthopedic Implants ◽  
Parietal Bone ◽  
Maximum Temperature ◽  
Cement Interface

Acrylic bone cement (ABC) is one of the most used materials in orthopedic surgery, mainly for the fixation of orthopedic implants to the bone. However, ABCs usually present lack of biological activity and osseointegration capacity that leads to loosening of the prosthesis. This work reports the effect of introducing graphene oxide (GO) and chitosan (CS), separately or together, in the ABC formulation on setting performance, mechanical behavior, and biological properties. Introduction of both CS and GO to the ABC decreased the maximum temperature by 21% and increased the antibacterial activity against Escherichia coli by 87%, while introduction of only CS decreased bending strength by 32%. The results of cell viability and cell adhesion tests showed in vitro biocompatibility. The in vivo response was investigated using both subdermal and bone parietal implantations in Wistar rats. Modified ABCs showed absence of immune response, as confirmed by a normal inflammatory response in Wistar rat subdermal implantation. The results of the parietal bone implantation showed that the addition of CS and GO together allowed a near total healing bone–cement interface, as observed in the micrographic analysis. The overall results support the great potential of the modified ABCs for application in orthopedic surgery mainly in those cases where osseointegration is required.

scholarly journals Bond Strength Evaluation of Inlay-Retained Resin-Bonded Fixed Partial Dentures with Two Different Cavity Designs and Two Different Adhesive Systems: In Vitro Study

2020 ◽  
Vol 24 (1) ◽  
pp. 21-28
Author(s):  
Ediz Kale ◽  
Ayça Deniz İzgi ◽  
Remzi Niğiz
Keyword(s):  
Bond Strength ◽  
In Vitro Study ◽  
Adhesive System ◽  
Vitro Study ◽  
Aqueous Environment ◽  
Cement Interface ◽  
Significant Difference ◽  
Mode Of Failure ◽  
Slot Cavity

SummaryBackground/Aim: The purpose of this in-vitro study was to compare the resin-bonded fixed partial dentures (RBFPD) fabricated using two different structural designs and two different antibacterial adhesive lutting protocols in regard to their resistance to debonding.Material and Methods: Forty samples for a model with single missing molar were divided into 4 groups (M1, M2, C1, C2) (n=10). M1 and M2 were prepared in accordance with modified inlay slot-cavity retained RBFPD design; C1 and C2 were prepared according to conventional inlay slot-cavity retained RBFPD design. M1 and C1 cavities were treated with 2% chlorhexidine-based (CHX) cavity disinfectant and 10-methacryloyloxydecyl dihydrogen phosphate (MDP) containing adhesive system; M2 and C2 cavities were treated with MDP and 12-methacryloyloxydodecylpyridinium bromide (MDPB) containing adhesive system featuring antibacterial cavity cleansing effect. The RBFPDs were made of base-metal alloy and their fit surfaces sandblasted with aluminium oxide (Al2O3). Adhesive resin cement was used for cementation, and the RBFPD retainers were interlocked into their corresponding inlay cavities using composite resin. After 1 week being immersed in aqueous environment, the RBFPDs were subjected to tensile loading at a crosshead speed of 1 mm/min until failure. One way ANOVA and Tukey HSD tests were used for statistical evaluation (α=0.05). Mode of failure and tooth damage was also noted.Results: Mean tensile bond strength values were 356 N for M1, 305 N for M2, 467 N for C1, and 455 N for C2. Tensile strength values of C1 and C2 were significantly higher than those of M1 and M2 (p<0.05). The mode of failure was mostly adhesive in character at the metal-cement interface in all groups. Tooth fracture was observed nearly in all specimens. No significant difference was detected between the antibacterial adhesive lutting protocols (p>0.05).Conclusions: The RBFPDs with the conventional design were found to be more retentive than those with the modified design. Using an adhesive system featuring antibacterial properties with no need of separate antibacterial agent application during bonding may be favourable.

The in vitro Measurement of Bone-Cement Interface Pressures and Shear Strengths in the Femur: A Comparison of two Cementation Methods

1995 ◽  
Vol 5 (3-4) ◽  
pp. 124-130 ◽  
Author(s):  
A. J. Ward ◽  
E. J. Smith ◽  
J. W. Barlow ◽  
A. Powell ◽  
M. Halawa ◽  
...  
Keyword(s):  
Bone Cement ◽  
Hip Arthroplasty ◽  
High Viscosity ◽  
Femoral Bone ◽  
Cement Interface ◽  
Cement Injection ◽  
Paired Samples ◽  
In Vitro Simulation ◽  
Interface Pressures

Two differing cementation methods were investigated in an in vitro simulation of hip arthroplasty. The bone-cement interface pressures were recorded during cement injection and stem insertion in matched pairs of fresh cadaveric femora. Reduced viscosity cement injected with a cement gun and proximal seal was compared with injection of high viscosity cement and finger-packing in each pair. The resultant shear strength of the bone-cement interface was measured by push-out tests. Results were analysed using the Wilcoxon ranked sum test for paired samples. The Exeter method of cementation produced significantly higher mean and maximum pressures above the bleeding pressure of femoral bone at all interface levels during cement injection. This was associated with significantly greater mean shear strengths. The authors conclude that the Exeter pressurization system for cementation overcomes the effect of femoral bone bleeding and improves the quality of the bone-cement interface. This may contribute to reduction in the incidence of loosening in cement hip arthroplasty.

scholarly journals Therapeutic effectiveness of frozen platelet concentrates for transfusion

Blood ◽  
1981 ◽  
Vol 57 (2) ◽  
pp. 243-249 ◽  
Author(s):  
HM Lazarus ◽  
EA Kaniecki-Green ◽  
SE Warm ◽  
M Aikawa ◽  
RH Herzig
Keyword(s):  
Vapor Phase ◽  
Platelet Concentrate ◽  
In Vitro Tests ◽  
Platelet Concentrates ◽  
Emergency Situations ◽  
Ultrastructural Studies ◽  
Significant Difference ◽  
Before And After ◽  
The Difference

Abstract Six patients received platelet concentrate transfusions from their HLA- identical siblings. Platelet concentrates were administered either fresh, or after being frozen in 10% dimethylsulfoxide, at a slow controlled rate (1 degree C/min) or rapidly (approximately 8 degrees C/min) in the vapor-phase of a liquid nitrogen refrigerator. The median freeze-thaw loss was 13.5%. The mean 1-hr and 20-hr corrected increments in platelet count were calculated for fresh platelet concentrates transfused before and after transfusion with controlled- rate frozen and vapor-phase frozen platelet concentrates. There was no significant difference among the first and second transfusion of fresh platelet concentrates, nor was the difference observed between fresh and controlled-rate frozen platelet concentrates significant. The difference between fresh and vapor-phase frozen platelet concentrates, and between controlled-rate frozen and vapor-phase frozen platelet concentrates were highly significant (p < 0.01). In vitro tests of aggregation using ristocetin and platelet ultrastructural studies paralleled the transfusion experience. Our results indicate that HLA- identical platelet concentrates can be successfully frozen and thawed for transfusion if a slow, controlled rate of freezing is employed. The use of HLA-identical frozen platelet concentrates may be important in emergency situations for the refractory patient and potentially for the establishment of a platelet concentrate bank.

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