The Experts below are selected from a list of 2061 Experts worldwide ranked by ideXlab platform
Andras Muhlrad - One of the best experts on this subject based on the ideXlab platform.
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Histone mixture and H2A histone induced bundle formation of Mg-F-actin folLowed by Low Speed Centrifugation and by light scattering.
2017Co-Authors: Edna Blotnick, Asaf Sol, Andras MuhlradAbstract:5.25–84 μg/ml histone mixture (A), or 1–4 μM (14–56 μg/ml) H2A histone (B), were added to 4 μM MgF-actin in pH7.4 F-buffer and centrifuged at Low Speed. Samples were centrifuged at 20,800xg for 8 min, supernatants run on SDS-PAGE and evaluated as described in MATERIALS and METHODS. The presented data are mean and standard deviation of three independent experiments. Insets: actin lanes, representatives of three independent experiments, from SDS-PAGE of Low Speed Centrifugation supernatants. (C) 5.25–42 μg/ml histone mixture or (D) 1–4 μM (14–56 μg/ml) H2A histone were added to 4 μM MgF-actin in pH7.4 F-buffer and the light scattering change was folLowed as described in MATERIALS and METHODS. Presented data are representative of three independent experiments. All measurements were done at pH7.4 in F-buffer.
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Effect of 0–400 mM NaCl on the sedimentation of 63 μg/ml histone mixture or 4 μM (56 μg/ml) H2A histone bundled 4 μM MgF-actin as measured by Low Speed Centrifugation and light scattering.
2017Co-Authors: Edna Blotnick, Asaf Sol, Andras MuhlradAbstract:Sedimentation: (A), Bundling by histone mixture and H2A histone. Samples were centrifuged at 20800xg for 8 min, supernatants run on SDS-PAGE and evaluated as described in MATERIALS and METHODS. The presented data are mean and standard deviation of three independent experiments. Insets: actin lanes, representatives of three independent experiments, from the SDS-PAGE of supernatants after Low Speed Centrifugation. Light scattering: (B), 4x100 mM NaCl was added to histone mixture bundled 4 μM MgF-actin, (C), 3x100 mM NaCl was added to H2A histone bundled 4 μM MgF-actin and the light scattering was measured. Asterisks* represent 100 mM NaCl addition. Light scattering change was folLowed as described in MATERIALS and METHODS. Presented data are representative of three independent experiments.
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Effect of cofilin on the sedimentation of 4 μM MgF-actin bundled by histone mixture or H2A histone.
2017Co-Authors: Edna Blotnick, Asaf Sol, Andras MuhlradAbstract:(A), 2–8 μM cofilin added to 4 μM F-actin bundled by 10.5 and 63 μg/ml histone mixture or (B) by 1 μM (14 μg/ml) and 3 μM (42 μg/ml) H2A histone. (C), 42 μg/ml histone mixture or 4 μM (56 μg/ml) H2A histone and 2.5 or 5 μM cofilin were added simultaneously to 4 μM F-actin. Samples were centrifuged at 20800xg for 8 min, supernatants run on SDS-PAGE and evaluated as described in MATERIALS and METHODS. The presented data are mean and standard deviation of three independent experiments. Insets: lanes of SDS-PAGE gels, representatives of three independent experiments, obtained from SDS-PAGE of Low Speed Centrifugation supernatants.
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Effect of DNA on the bundling of F-actin by histone.
2017Co-Authors: Edna Blotnick, Asaf Sol, Andras MuhlradAbstract:(A), Effect of 25–400 μg/ml DNA on the sedimentation of 4 μM MgF-actin bundled by 42 μg/ml histone mixture or 3 μM (42 μg/ml) H2A histone. (B), Effect of 0–200 μg/ml DNA digested by Staphylococcus aureus micrococcal DNase on the sedimentation of 4 μM MgF-actin bundled by 42 μg/ml histone mixture or by 3 μM (42 μg/ml) H2A histone. 4 μg/ml DNA was digested by 20 μg/ml micrococcal DNase at 37°C for 30 min. Samples were centrifuged at 20800xg for 8 min, supernatants run on SDS-PAGE and evaluated as described in MATERIALS and METHODS. The presented data are mean and standard deviation of three independent experiments. Insets: actin lanes, representatives of three independent experiments, from the SDS-PAGE of Low Speed Centrifugation supernatants.
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Effect of DNase1 on the light scattering and sedimentation of 4 μM MgF-actin bundled by histone mixture or H2A histone.
2017Co-Authors: Edna Blotnick, Asaf Sol, Andras MuhlradAbstract:(A) Effect of 9 μM DNase1 on the light scattering of 4 μM MgF-actin bundled by 63 μg/ml histone mixture or 3 μM (42 μg/ml) H2A histone. Light scattering change was folLowed as described in MATERIALS and METHODS. Presented data are representative of three independent experiments. (B). Effect of 2–15 μM DNase1 on the sedimentation of 4 μM MgF-actin bundled by 63 μg/ml histone mixture or 3 μM (42 μg/ml) H2A histone. The difference between the amount of actin sedimented folLowing DNase1 treatment of histone mixture and H2A histone bundled actin is highly significant. Samples were centrifuged at 20800xg for 8 min, supernatants run on SDS-PAGE and evaluated as described in MATERIALS and METHODS. The presented data are mean and standard deviation of three independent experiments. Insets: actin lanes, representatives of three independent experiments, from SDS-PAGE of Low Speed Centrifugation supernatants.
Choukroun Joseph - One of the best experts on this subject based on the ideXlab platform.
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Injectable-platelet rich fibrin using the Low Speed Centrifugation concept improves cartilage regeneration when compared to platelet-rich plasma.
'Informa UK Limited', 2019Co-Authors: Abd El Raouf Mustafa, Wang Xuzhu, Si Miusi, Chai Jihua, Mohamed Abdel-aal, Abdel Basit, Nefissa Helmy, Mekkawy M, Ghanaati Shahram, Choukroun Joseph, Choukroun Elisa, Zhang YufengAbstract:The aim of the present study was to evaluate the effect of injectable platelet-rich fibrin (i-PRF) on cultivated chondrocytes and osteochondral regeneration in critical-sized osteochondral defect of the rabbit's knee in comparison to autologous platelet-rich plasma (PRP). Chondrocytes were first investigated for their ability to proliferate and differentiate in response to PRP and i-PRF. Thereafter, full-thickness critical-sized osteochondral defects 5 mm in diameter and 5 mm in depth were created in the knee joint of 12 adult female New Zealand White rabbits. Defects were regenerated with either PRP or i-PRF and compared to control. Animals were sacrificed at 4 and 12 weeks postoperatively and evaluated histologically by macroscopic and microscopic examination for cartilage regeneration. i-PRF significantly promoted chondrocyte proliferation and mRNA levels of Sox9, collagen type II, and aggrecan when compared to PRP and control. Histological analysis revealed that at 4 weeks, macroscopic ICRS scores from the i-PRF group were significantly enhanced when compared to the PRP and control groups. At 12 weeks post surgery, the microscopic ICRS scores demonstrated that the i-PRF group significantly improved cartilage regeneration when compared to PRP. In conclusion, the use of i-PRF using the Low Speed Centrifugation concept significantly promoted chondrocyte activity and further improved cartilage regeneration when compared to PRP. The histological results revealed early and better cartilage regeneration within 4 weeks postoperatively when i-PRF was utilized and the results were maintained at 12 weeks. Future clinical studies are now needed investigating the regenerative potential of i-PRF in comparison to PRP for knee regeneration
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Telomere length and genetic variations affecting telomere length as biomarkers for facial regeneration with platelet-rich fibrin based on the Low-Speed Centrifugation concept.
'Wiley', 2019Co-Authors: Nacopoulos Cleopatra, Choukroun Joseph, Gkouskou Kalliopi, Karypidis Dimitrios, Vlastos Ioannis, Vesala Anna-maria, Miron, Richard John, Prokopakis EmmanuelAbstract:BACKGROUND Platelet-Rich Fibrin (PRF), a fibrin matrix produced by single blood Centrifugation that contains leukocytes, platelets, and growth factors, is increasingly being utilized for facial regeneration purposes. However, our understanding of the involved pathophysiological mechanisms affecting regeneration is limited and current protocols require better optimization. Biomarkers that are related to skin aging such as telomere length (TL) have been proposed as a mean to analyze patients' stratification. OBJECTIVE Our aim is to study whether the outcomes of a facial regeneration protocol performed with PRF are related to TL and genetic variations affecting TL. This can aid in the standardization of a surgical aesthetic protocol. PATIENTS AND METHODS In all, 41 patients treated with PRF produced with the Low-Speed Centrifugation concept were included in this observational study. The correlation between TL and genetic variations were assessed versus treatment outcomes, namely the number of sessions and aesthetic results utilizing the FACE-Q skin satisfaction questionnaire. RESULTS In all, 39 of the 41 patients completed the treatment. TL correlated with the initial responses to FACE-Q (ρ = .33, P = .05). Genetic variations affecting TL was related to the change of FACE-Q (ρ = .35, P = .034) as well as to the number of treatment sessions (ρ = .38, P = .019). CONCLUSIONS Telomere length (TL) was related to patient perceived facial skin appearance. In addition, genetic variations affecting TL were related to the final outcomes (number of sessions and improvements of FACE-Q results) and may be a useful biomarker for future regenerative procedures performed with PRF for facial regeneration
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Reduction of relative Centrifugation force within injectable platelet-rich-fibrin (PRF) concentrates advances patients’ own inflammatory cells, platelets and growth factors : the first introduction to the Low Speed Centrifugation concept
2017Co-Authors: Choukroun Joseph, Ghanaati ShahramAbstract:Purpose: The aim of this study was to analyze systematically the influence of the relative Centrifugation force (RCF) on leukocytes, platelets and growth factor release within fluid platelet-rich fibrin matrices (PRF). Materials and methods: Systematically using peripheral blood from six healthy volunteers, the RCF was reduced four times for each of the three experimental protocols (I–III) within the spectrum (710–44 g), while maintaining a constant Centrifugation time. FLow cytometry was applied to determine the platelets and leukocyte number. The growth factor concentration was quantified 1 and 24 h after clotting using ELISA. Results: Reducing RCF in accordance with protocol-II (177 g) led to a significantly higher platelets and leukocytes numbers compared to protocol-I (710 g). Protocol-III (44 g) showed a highly significant increase of leukocytes and platelets number in comparison to -I and -II. The growth factors’ concentration of VEGF and TGF-β1 was significantly higher in protocol-II compared to -I, whereas protocol-III exhibited significantly higher growth factor concentration compared to protocols-I and -II. These findings were observed among 1 and 24 h after clotting, as well as the accumulated growth factor concentration over 24 h. Discussion: Based on the results, it has been demonstrated that it is possible to enrich PRF-based fluid matrices with leukocytes, platelets and growth factors by means of a single alteration of the Centrifugation settings within the clinical routine. Conclusions: We postulate that the so-called Low Speed Centrifugation concept (LSCC) selectively enriches leukocytes, platelets and growth factors within fluid PRF-based matrices. Further studies are needed to evaluate the effect of cell and growth factor enrichment on wound healing and tissue regeneration while comparing blood concentrates gained by high and Low RCF
Robert Webster - One of the best experts on this subject based on the ideXlab platform.
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application of Centrifugation to the large scale purification of electric arc produced single walled carbon nanotubes
Journal of the American Chemical Society, 2006Co-Authors: Aiping Yu, Danylo Fakhrutdinov, Elena Bekyarova, Mikhail E Itkis, Robert WebsterAbstract:We report a further advance in the bulk purification of nitric acid-treated single-walled carbon nanotubes (SWNTs) by use of high-Speed Centrifugation. We have already shown that Low-Speed Centrifugation is effective in removing amorphous carbon (AC). In these earlier experiments, the AC preferentially suspends in aqueous dispersions on Low-Speed Centrifugation (2000g), leaving the SWNTs in the sediment. In a surprising reversal, we now show that high-Speed Centrifugation (20000g) of well-dispersed preparations is effective in sedimenting carbon nanoparticles (CNP), while leaving the SWNTs suspended in aqueous media. Taken together, these two techniques alLow the bulk scale (10 g) purification of SWNTs by efficiently separating the two main contaminants, in an industrially viable process. We show that the mechanism of these separations is based on the differential charging (ζ-potential) of the AC, CNPs, and SWNTs that comes about during the chemical processing. Due to their more robust structure, nitric a...
Ghanaati Shahram - One of the best experts on this subject based on the ideXlab platform.
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Injectable-platelet rich fibrin using the Low Speed Centrifugation concept improves cartilage regeneration when compared to platelet-rich plasma.
'Informa UK Limited', 2019Co-Authors: Abd El Raouf Mustafa, Wang Xuzhu, Si Miusi, Chai Jihua, Mohamed Abdel-aal, Abdel Basit, Nefissa Helmy, Mekkawy M, Ghanaati Shahram, Choukroun Joseph, Choukroun Elisa, Zhang YufengAbstract:The aim of the present study was to evaluate the effect of injectable platelet-rich fibrin (i-PRF) on cultivated chondrocytes and osteochondral regeneration in critical-sized osteochondral defect of the rabbit's knee in comparison to autologous platelet-rich plasma (PRP). Chondrocytes were first investigated for their ability to proliferate and differentiate in response to PRP and i-PRF. Thereafter, full-thickness critical-sized osteochondral defects 5 mm in diameter and 5 mm in depth were created in the knee joint of 12 adult female New Zealand White rabbits. Defects were regenerated with either PRP or i-PRF and compared to control. Animals were sacrificed at 4 and 12 weeks postoperatively and evaluated histologically by macroscopic and microscopic examination for cartilage regeneration. i-PRF significantly promoted chondrocyte proliferation and mRNA levels of Sox9, collagen type II, and aggrecan when compared to PRP and control. Histological analysis revealed that at 4 weeks, macroscopic ICRS scores from the i-PRF group were significantly enhanced when compared to the PRP and control groups. At 12 weeks post surgery, the microscopic ICRS scores demonstrated that the i-PRF group significantly improved cartilage regeneration when compared to PRP. In conclusion, the use of i-PRF using the Low Speed Centrifugation concept significantly promoted chondrocyte activity and further improved cartilage regeneration when compared to PRP. The histological results revealed early and better cartilage regeneration within 4 weeks postoperatively when i-PRF was utilized and the results were maintained at 12 weeks. Future clinical studies are now needed investigating the regenerative potential of i-PRF in comparison to PRP for knee regeneration
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Reduction of relative Centrifugation force within injectable platelet-rich-fibrin (PRF) concentrates advances patients’ own inflammatory cells, platelets and growth factors : the first introduction to the Low Speed Centrifugation concept
2017Co-Authors: Choukroun Joseph, Ghanaati ShahramAbstract:Purpose: The aim of this study was to analyze systematically the influence of the relative Centrifugation force (RCF) on leukocytes, platelets and growth factor release within fluid platelet-rich fibrin matrices (PRF). Materials and methods: Systematically using peripheral blood from six healthy volunteers, the RCF was reduced four times for each of the three experimental protocols (I–III) within the spectrum (710–44 g), while maintaining a constant Centrifugation time. FLow cytometry was applied to determine the platelets and leukocyte number. The growth factor concentration was quantified 1 and 24 h after clotting using ELISA. Results: Reducing RCF in accordance with protocol-II (177 g) led to a significantly higher platelets and leukocytes numbers compared to protocol-I (710 g). Protocol-III (44 g) showed a highly significant increase of leukocytes and platelets number in comparison to -I and -II. The growth factors’ concentration of VEGF and TGF-β1 was significantly higher in protocol-II compared to -I, whereas protocol-III exhibited significantly higher growth factor concentration compared to protocols-I and -II. These findings were observed among 1 and 24 h after clotting, as well as the accumulated growth factor concentration over 24 h. Discussion: Based on the results, it has been demonstrated that it is possible to enrich PRF-based fluid matrices with leukocytes, platelets and growth factors by means of a single alteration of the Centrifugation settings within the clinical routine. Conclusions: We postulate that the so-called Low Speed Centrifugation concept (LSCC) selectively enriches leukocytes, platelets and growth factors within fluid PRF-based matrices. Further studies are needed to evaluate the effect of cell and growth factor enrichment on wound healing and tissue regeneration while comparing blood concentrates gained by high and Low RCF
Li Feng - One of the best experts on this subject based on the ideXlab platform.
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an improved method for extracting bacteria from soil for high molecular weight dna recovery and bac library construction
Journal of Microbiology, 2010Co-Authors: Jingquan Li, Li FengAbstract:Separation of bacterial cells from soil is a key step in the construction of metagenomic BAC libraries with large DNA inserts. Our results showed that when combined with sodium pyro-phosphate and homogenization for soil dispersion, sucrose density gradient Centrifugation (SDGC) was more effective at separating bacteria from soil than was Low Speed Centrifugation (LSC). More than 70% of the cells, along with some soil colloids, were recovered with one round of Centrifugation. A solution of 0.8% NaCl was used to resuspend these cell and soil pellets for purification with nycodenz density gradient Centrifugation (NDGC). After purification, more than 30% of the bacterial cells in the primary soil were extracted. This procedure effectively removed soil contamination and yielded sufficient cells for high molecular weight (HMW) DNA isolation. Ribosomal intergenic spacer analysis (RISA) showed that the microbial community structure of the extracted cells was similar to that of the primary soil, suggesting that this extraction procedure did not significantly change the the soil bacteria community structure. HMW DNA was isolated from bacterial cells extracted from red soil for metagenomic BAC library construction. This library contained DNA inserts of more than 200 Mb with an average size of 75 kb.
