Peri-Implant Strain in an In Vitro Model

2015 ◽  
Vol 41 (5) ◽  
pp. 532-537 ◽  
Author(s):  
Souheil Hussaini ◽  
Tritala K. Vaidyanathan ◽  
Abhinav P. Wadkar ◽  
Firas A. Al Quran ◽  
David Ehrenberg ◽  
...  
Keyword(s):  
In Vitro Model ◽  
Mechanical Test ◽  
Statistical Treatment ◽  
Test System ◽  
Strain Gages ◽  
Different Types ◽  
Bone Atrophy ◽  
The Mean ◽  
Vitro Model

An in vitro experimental model was designed and tested to determine the influence that peri-implant strain may have on the overall crestal bone. Strain gages were attached to polymethylmethacrylate (PMMA) models containing a screw-type root form implant at sites 1 mm from the resin-implant interface. Three different types of crown superstructures (cemented, 1-screw [UCLA] and 2-screw abutment types) were tested. Loading (1 Hz, 200 N load) was performed using a MTS Mechanical Test System. The strain gage data were stored and organized in a computer for statistical treatment. Strains for all abutment types did not exceed the physiological range for modeling and remodeling of cancellous bone, 200–2500 μɛ (microstrain). For approximately one-quarter of the trials, the strain values were less than 200 μɛ the zone for bone atrophy. The mean microstrain obtained was 517.7 μɛ. In conclusion, the peri-implant strain in this in vitro model did not exceed the physiologic range of bone remodeling under axial occlusal loading.

scholarly journals Linezolid Compared with Eperezolid, Vancomycin, and Gentamicin in an In Vitro Model of Antimicrobial Lock Therapy for Staphylococcus epidermidis Central Venous Catheter-Related Biofilm Infections

2003 ◽  
Vol 47 (10) ◽  
pp. 3145-3148 ◽  
Author(s):  
John Curtin ◽  
Martin Cormican ◽  
Gerard Fleming ◽  
John Keelehan ◽  
Emer Colleran
Keyword(s):  
Central Venous Catheter ◽  
Staphylococcus Epidermidis ◽  
In Vitro Model ◽  
Physiological Saline ◽  
Venous Catheter ◽  
Saline Control ◽  
Central Venous ◽  
The Mean ◽  
Vitro Model

ABSTRACT Central venous catheter (CVC)-related infection (CVC-RI) is a common complication of CVC use. The most common etiological agents of CVC-RI are gram-positive organisms, in particular, staphylococci. An in vitro model for the formation of biofilms by Staphylococcus epidermidis ATCC 35984 on polyurethane coupons in a modified Robbins device was established. Biofilm formation was confirmed by electron microscopy and was quantified by determination of viable counts. Mueller-Hinton broth was replaced with sterile physiological saline (control) or a solution of vancomycin (10 mg/ml), gentamicin (10 mg/ml), linezolid (2 mg/ml), or eperezolid (4 mg/ml). Viable counts were performed with the coupons after exposure to antimicrobials for periods of 24, 72, 168, and 240 h. The mean viable count per coupon following establishment of the biofilm was 4.6 × 108 CFU/coupon, and that after 14 days of exposure to physiological saline was 2.5 × 107 CFU/coupon. On exposure to vancomycin (10 mg/ml), the mean counts were 2.5 × 107 CFU/coupon at 24 h, 4.3 × 106 CFU/coupon at 72 h, 1.4 × 105 CFU/coupon at 168 h, and undetectable at 240 h. With gentamicin (10 mg/ml) the mean counts were 2.7 × 107 CFU/coupon at 24 h, 3.7 × 106 CFU/coupon at 72 h, 8.4 × 106 CFU/coupon at 168 h, and 6.5 × 106 CFU/coupon at 240 h. With linezolid at 2 mg/ml the mean counts were 7.1 × 105 CFU/coupon at 24 h and not detectable at 72, 168, and 240 h. With eperezolid (4 mg/ml) no viable cells were recovered after 168 h. These data suggest that linezolid (2 mg/ml) and eperezolid (4 mg/ml) achieve eradication of S. epidermidis biofilms more rapidly than vancomycin (10 mg/ml) and gentamicin (10 mg/ml).

In vitro model for the response to irradiation of different types of human intracranial tumours

1987 ◽  
Vol 85 (1-2) ◽  
pp. 46-49 ◽  
Author(s):  
H. Fischer ◽  
G. H. Hartmann ◽  
V. Sturm ◽  
K. Schwechheimer ◽  
O. Krauss ◽  
...  
Keyword(s):  
In Vitro Model ◽  
Intracranial Tumours ◽  
Different Types ◽  
Vitro Model

scholarly journals Reticulocyte rigidity and passage through endothelial-like pores

Blood ◽  
1991 ◽  
Vol 78 (11) ◽  
pp. 3037-3042 ◽  
Author(s):  
RE Waugh
Keyword(s):  
Mechanical Properties ◽  
Bone Marrow ◽  
In Vitro Model ◽  
Gradient Centrifugation ◽  
The Mean ◽  
The Difference ◽  
Vitro Model ◽  
Mean Time ◽  
Endothelial Pores

The importance of cell rigidity in regulating the release of reticulocytes from the bone marrow has been investigated in a model system. Reticulocytes were obtained from phlebotomized rabbits and separated from whole blood by discontinuous density gradient centrifugation. The mechanical properties of the cells were tested. Using single-cell micromechanical techniques, the membrane elastic rigidity and the viscoelastic response of reticulocyte and mature cell populations were measured. The reticulocyte membranes were more rigid than the mature membranes, but the reticulocyte properties were heterogeneous, and some cells exhibited behavior indistinguishable from the mature cells. The mean time constant for viscoelastic recovery was the same for reticulocytes as for mature cells, but the variability within the reticulocyte population was greater. The possible influence of this increased rigidity on cell egress from the bone marrow was tested using an in vitro model of the thin endothelial pores found within the marrow. A silicon wafer approximately 0.1 microns in thickness and containing a small (1.2-microns diameter) pore in its center was cemented over the tip of a large (15.0-microns ID) micropipette. The passage of cells through the pore was observed as a function of the pressure across the pore. Consistent with the difference in mechanical properties, the reticulocytes required greater pressures (as great as 4.0 mm Hg compared with less than 1.0 mm Hg) and took longer to traverse the pore. These measurements support the postulate that deformability is important in the regulation of the release of cells from bone marrow.

scholarly journals Reticulocyte rigidity and passage through endothelial-like pores

Blood ◽  
1991 ◽  
Vol 78 (11) ◽  
pp. 3037-3042 ◽  
Author(s):  
RE Waugh
Keyword(s):  
Mechanical Properties ◽  
Bone Marrow ◽  
In Vitro Model ◽  
Gradient Centrifugation ◽  
The Mean ◽  
The Difference ◽  
Vitro Model ◽  
Mean Time ◽  
Endothelial Pores

Abstract The importance of cell rigidity in regulating the release of reticulocytes from the bone marrow has been investigated in a model system. Reticulocytes were obtained from phlebotomized rabbits and separated from whole blood by discontinuous density gradient centrifugation. The mechanical properties of the cells were tested. Using single-cell micromechanical techniques, the membrane elastic rigidity and the viscoelastic response of reticulocyte and mature cell populations were measured. The reticulocyte membranes were more rigid than the mature membranes, but the reticulocyte properties were heterogeneous, and some cells exhibited behavior indistinguishable from the mature cells. The mean time constant for viscoelastic recovery was the same for reticulocytes as for mature cells, but the variability within the reticulocyte population was greater. The possible influence of this increased rigidity on cell egress from the bone marrow was tested using an in vitro model of the thin endothelial pores found within the marrow. A silicon wafer approximately 0.1 microns in thickness and containing a small (1.2-microns diameter) pore in its center was cemented over the tip of a large (15.0-microns ID) micropipette. The passage of cells through the pore was observed as a function of the pressure across the pore. Consistent with the difference in mechanical properties, the reticulocytes required greater pressures (as great as 4.0 mm Hg compared with less than 1.0 mm Hg) and took longer to traverse the pore. These measurements support the postulate that deformability is important in the regulation of the release of cells from bone marrow.

scholarly journals Effects of homeopathic medicines on macrophage - E. cuniculi interaction in vitro

2021 ◽  
Vol 17 (1) ◽  
pp. 01-01
Author(s):  
Leoni Villano Bonamin ◽  
Mirian Yaeko DO Nagai ◽  
Luciane Costa Dalboni ◽  
Thayná Neves Cardoso ◽  
Michelle S Correia ◽  
...  
Keyword(s):  
In Vitro Model ◽  
Cytokine Production ◽  
Alcohol Concentration ◽  
Encephalitozoon Cuniculi ◽  
Acridine Orange Staining ◽  
Neural Tissues ◽  
Different Types ◽  
Staining Methods ◽  
Vitro Model

Encephalitozoon cuniculi (E. cuniculi) is a fungus that behaves as an intracellular parasite infecting different types of cells. In rabbits and immunosuppressed animals of other species, including humans, it parasites neural tissues causing a highly characteristic neurological syndrome, for which repertory analysis indicates Phosphorus. Successful treatment of 7 naturally infected rabbits with Phosphorus confirmed that this medicine probably is the remedy of the ‘epidemic genius’ of microsporidiosis. In the present study, an in vitro model was used to evidence the intracellular relationship between macrophages and E. cuniculi after treatment of co-cultures with different potencies of Phosphorus. RAW 254.7 macrophages were co-cultivated with E. cuniculi and treated with Phosphorus 6cH, 30cH and 200cH. Controls were untreated co-cultures and cultures treated with vehicle (0.06% final alcohol concentration). Phagocytosis and lysosome activity were after after 1 and 24 hours of incubation by means of the calcofluor and acridine orange staining methods, followed by automatic image analysis (Metamorph®). Cytokine production was assessed with the MAGPIX®-Luminex system. The vehicle increased IL-6, MCP-1 and MIP1 production (p

scholarly journals Levetiracetam and Rufinamide are effective at supressing spike and wave seizure activity in an in vitro model of absence epilepsy

2018 ◽  
Author(s):  
Virdziniha Todorova ◽  
Georgina Ford ◽  
Roger D. Traub ◽  
Miles. A. Whittington ◽  
Stephen. P. Hall
Keyword(s):  
In Vitro Model ◽  
Seizure Activity ◽  
Absence Epilepsy ◽  
Absence Seizures ◽  
Clinical Burden ◽  
Different Types ◽  
Vitro Model ◽  
Atypical Absence ◽  
Component Amplitude

AbstractSpike-and-wave discharges (SpW) are seen in absence-type epilepsies. They are heterogeneous in terms of their clinical burden and their electrographic signature, which is used to classify different types of absence seizures; typical absence, in which SpW frequency is 3-4Hz and atypical absence, which shows a slower 1-2Hz frequency. Treatment of SpW varies dependent upon the syndrome, but both Valproic Acid (VPA) and Ethosuximide (ESM) are shown to be effective in controlling typical absence seizures. Other anti-epileptic’s (AED’s), Levetiracetam (LEV) and Rufinamide (RUF), have shown promise in treating absence epilepsies and their associated syndromes. Here we examine the efficacy of these AED’s on an in vitro model of SpW.Both LEV and RUF show an effective reduction in both the number of SpW events and the spike component amplitude; VPA shows no effect, whilst ESM enhances the spike amplitude. Phenytoin exacerbates the SpW activity, increasing both the number of SpW, amplitude of the SpW and the number of spikes within each event. These data suggest that both LEV and RUF could be effective in the treatment of absence-type epilepsies. They also suggest this model could be an effective tool to test other AED’s aimed at treating atypical absence syndromes.

In Vitro Model on Glass Surfaces for Complex Interactions between Different Types of Cells

Langmuir ◽  
2010 ◽  
Vol 26 (23) ◽  
pp. 17790-17794 ◽  
Author(s):  
Zhenling Chen ◽  
Wei Chen ◽  
Bo Yuan ◽  
Le Xiao ◽  
Dingbin Liu ◽  
...  
Keyword(s):  
In Vitro Model ◽  
Complex Interactions ◽  
Different Types ◽  
Vitro Model ◽  
Glass Surfaces

Iohexol Transmembrane Clearance during Modeled Continuous Renal Replacement Therapy

2015 ◽  
Vol 39 (1-3) ◽  
pp. 188-192
Author(s):  
J. Michael Yardman-Frank ◽  
Renee-Claude Mercier ◽  
Craig S. Wong ◽  
A. Mary Vilay
Keyword(s):  
Molecular Weight ◽  
Renal Replacement Therapy ◽  
Continuous Renal Replacement Therapy ◽  
Replacement Therapy ◽  
In Vitro Model ◽  
Ultrafiltration Rate ◽  
Continuous Hemofiltration ◽  
The Mean ◽  
Vitro Model

Background/Aims: Urea clearance during continuous renal replacement therapy (CRRT) is not representative of middle molecular weight solute clearances. We aimed to characterize iohexol, molecular weight 821 Da, clearance during continuous hemofiltration (CH) and continuous hemodialysis (CHD). Methods: Using an in vitro model, iohexol sieving coefficients (SC) and saturation coefficients (SA) were determined with the M100 membrane at ultrafiltration/dialysate rates of 1, 2, 3, 4, and 6 l/h. Iohexol transmembrane clearance was calculated using the measured SC and SA. Results: During CH, the value of iohexol SC remained approximately 1 at all ultrafiltration rates studied. In contrast, during CHD iohexol the mean SA was 1.02 ± 0.05 at a dialysate rate 1 l/h and decreased significantly with higher dialysate rates to a mean SA of 0.57 ± 0.12 at a dialysate rate of 6 l/h. Conclusions: At higher effluent flow rates, CH was more effective in removing iohexol than CHD. CH transmembrane clearance of iohexol appears to approximate the ultrafiltration rate.

Comment on the paper, “Growth of yeast cultures as in vitro model for investigating homœopathic remedies”

1985 ◽  
Vol 74 (02) ◽  
pp. 93-96 ◽  
Author(s):  
Rose D. Baker ◽  
C.W. Smith
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Growth Rate ◽  
In Vitro Model ◽  
Mean Value ◽  
Statistical Test ◽  
Yeast Cultures ◽  
The Mean ◽  
Vitro Model

SummaryA recent paper by Steffen1 repeating earlier work by Jones et al.2 failed to confirm any effect of potencies of Pulsatilla on the growth rate of cultures of Saccharomyces cerevisiae which had previously been reported.We find that using a more specific statistical test on the results given by Steffen1 it can be shown that these results contain almost the same periodicity with potency that Jones et al.2 reported, although only corresponding to a variation of ±1.5% about the mean value.

An in vitro model for investigation of vitamin A effects on wound healing

2021 ◽  
pp. 1-6
Author(s):  
Hoda Keshmiri Neghab ◽  
Mohammad Hasan Soheilifar ◽  
Gholamreza Esmaeeli Djavid
Keyword(s):  
Wound Healing ◽  
Endothelial Cell ◽  
Vitamin A ◽  
In Vitro Model ◽  
Cellular Proliferation ◽  
Endothelial Cell Migration ◽  
Normal Fibroblast ◽  
Anti Inflammatory ◽  
Vitro Model

Abstract. Wound healing consists of a series of highly orderly overlapping processes characterized by hemostasis, inflammation, proliferation, and remodeling. Prolongation or interruption in each phase can lead to delayed wound healing or a non-healing chronic wound. Vitamin A is a crucial nutrient that is most beneficial for the health of the skin. The present study was undertaken to determine the effect of vitamin A on regeneration, angiogenesis, and inflammation characteristics in an in vitro model system during wound healing. For this purpose, mouse skin normal fibroblast (L929), human umbilical vein endothelial cell (HUVEC), and monocyte/macrophage-like cell line (RAW 264.7) were considered to evaluate proliferation, angiogenesis, and anti-inflammatory responses, respectively. Vitamin A (0.1–5 μM) increased cellular proliferation of L929 and HUVEC (p < 0.05). Similarly, it stimulated angiogenesis by promoting endothelial cell migration up to approximately 4 fold and interestingly tube formation up to 8.5 fold (p < 0.01). Furthermore, vitamin A treatment was shown to decrease the level of nitric oxide production in a dose-dependent effect (p < 0.05), exhibiting the anti-inflammatory property of vitamin A in accelerating wound healing. These results may reveal the therapeutic potential of vitamin A in diabetic wound healing by stimulating regeneration, angiogenesis, and anti-inflammation responses.

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