The Effects of Injectable Platelet-Rich Fibrin and Advanced-Platelet Rich Fibrin on Gingival Fibroblast Cell Vitality, Proliferation, Differentiation

Ashour Sarraj H.,Mudalal Mahmoud,Al-Aroomi Omar A.,Al-Attab Reem,Li Wanxin,Yin Lihua 한국조직공학과 재생의학회 2023 조직공학과 재생의학 Vol.20 No.7

BACKGROUND: Injectable Platelet Rich Fibrin (I-PRF) and Advanced-Platelet Rich Fibrin (A-PRF) are autologous materials derived from patients’ blood and employed in periodontal regenerative surgery. Although I-PRF and A-PRF have different characteristics, their biological effects on gingival tissue fibroblasts remain unclear. This research aims to compare the in vitro capacity in inducing gene expression and proliferation of human gingival fibroblasts between A-PRF and I-PRF. METHODS: Human donors undergoing dental implant surgery were sampled for normal human gingival fibroblasts (NHGFCs), followed by preparing A-PRF and I-PRF membranes. Enzyme-linked immunosorbent assay (ELISA) kit was used to assess the release of platelet-derived growth factor-AA (PDGF-AA), transforming growth factor-beta1 (TGF- b1), and insulin growth factor-1 (IGF-1) at different periods. Cell viability and proliferation of A-PRF and I-PRF were compared using CCK-8 assay. The impacts of platelet concentration on human gingival fibroblast cells (HGFCs) were evaluated by quantifying the level or amount of phosphorylated extracellular signal-regulated protein kinase (p-ERK), and Matrix metalloproteinases (MMPs), MMP-1 and MMP-3. The effects of PRF on aged human gingival fibroblast cells were examined retrospectively. RESULTS: Overall, A-PRF demonstrated a higher release of TGF-B1 and PDGF-AA, while I-PRF reflected higher levels of IGF-1. A significantly higher level of cell proliferation was induced by higher cell proliferation by A-PRF and I-PRF. Additionally, in comparison to I-PRF, the expression of ERK phosphorylation and MMP-1 &MMP-3 in HGFCs was demonstrated by I-PRF and A-PRF. The increase in A-PRF was time-dependent (p\0.05). CONCLUSION: Both I-PRF and A-PRF induced a stimulatory biological impact on the proliferation of human gingiva fibroblasts, with the latter demonstrating better capacity in facilitating the release of different growth factors. A-PRF also induced higher gene expression of p-ERK, MMP-1 &MMP-3, and the proliferation of fibroblasts.

Identification and differential expression of two dehydrin cDNAs during maturation of Jatropha curcas seeds.

Omar, S A,Elsheery, N I,Kalaji, H M,Ebrahim, M K H,Pietkiewicz, S,Lee, C-H,Allakhverdiev, S I,Xu, Zeng-Fu Consultants Bureau [etc.] 2013 Biochemistry Vol.78 No.5

<P>Plant dehydrin proteins (DHNs) are known to be important for environmental stress tolerance and are involved in various developmental processes. Two full-length cDNAs JcDHN-1 and JcDHN-2 encoding two dehydrins from Jatropha curcas seeds were identified and characterized. JcDHN-1 is 764 bp long and contains an open reading frame of 528 bp. The deduced JcDHN-1 protein has 175 a.a. residues that form a 19.3-kDa polypeptide with a predicted isoelectric point (pI) of 6.41. JcDHN-2 is 855 bp long and contains an open reading frame of 441 bp. The deduced JcDHN-2 protein has 156 a.a. residues that form a 17.1-kDa polypeptide with a predicted pI of 7.09. JcDHN-1 is classified as type Y3SK2 and JcDHN-2 is classified as type Y2SK2 according to the YSK shorthand for structural classification of dehydrins. Homology analysis indicates that both JcDHN-1 and JcDHN-2 share identity with DHNs of other plants. Analysis of the conserved domain revealed that JcDHN-2 has glycoside hydrolase GH20 super-family activity. Quantitative real time PCR analysis for JcDHN-1 and JcDHN-2 expression during seed development showed increasing gene expression of both their transcript levels along with the natural dehydration process during seed development. A sharp increase in JcDHN-2 transcript level occurred in response to water content dropping from 42% in mature seeds to 12% in dry seeds. These results indicate that both JcDHNs have the potential to play a role in cell protection during dehydration occurring naturally during jatropha orthodox seed development.</P>

Strength of Thixoformed A319 Alloy at Elevated Temperature

A. M. Aziz,M. Z. Omar,Z. Sajuri 대한금속·재료학회 2021 METALS AND MATERIALS International Vol.27 No.7

When alloys are exposed to elevated temperatures they experience a decrement in their mechanical properties that leadsto material failure. However, the use of thixoforming, an alternative metal processing method, could enhance mechanicalproperties by minimising the defects that exist in as-received alloys. Therefore, this study aimed to determine the tensilestrength of thixoformed A319 under elevated temperatures by taking into account its intended use in vehicle cylinder headcomponents. Thixoformed A319 was compared with as-received alloy manufactured by permanent mould casting. Thecooling slope method was used to prepare the feedstock for thixoforming. The feedstock was reheated by induction heatinguntil it reached 574 °C and was then formed in a mould. Afterwards, the as-received and thixoformed samples underwentT6 heat treatment. The resulting samples were characterised by using optical microscopy, scanning electron microscopyequipped with energy dispersive X-ray, X-ray difraction analysis and a tensile test. Elevated temperature tensile tests wereperformed at 250 °C, in line with the temperature condition experienced by cylinder head components during operation. The ultimate tensile strength of the thixoformed samples was 30% higher than that of the as-received samples under elevatedtemperatures. Also, the analyses of the fracture surfaces showed that porosity, intermetallic compounds and impurities wereamongst the failure factors for both alloys.

Camel Milk as an Adjuvant Therapy for the Treatment of Type 1 Diabetes: Verification of a Traditional Ethnomedical Practice

Al-Tahtawy, Ragaa Hosny Mohamad,Zekry, Zekry Khalid,Al-Mehdar, Hussain A.,Salama, Omar,El-Shaieb, Siad Ebrahim,El-Basmy, Amany A.,Al-said, Mohamad Gamil Abdel Monem,Sharawy, Sabry Mohamed The Korean Society of Food Science and Nutrition 2009 Journal of medicinal food Vol.12 No.2

There is a traditional belief in the Middle East that regular consumption of camel milk may aid in prevention and control of diabetes. The aim of this work was to evaluate the efficacy of camel milk as an adjuvant therapy in young type 1 diabetics. This 16-week randomized study enrolled 54 type 1 diabetic patients (average age 20 years) selected from those attending the outpatient diabetes clinic of the Menofia University Hospital, affiliated with Egypt's National Cancer Institute. Subjects were randomly divided into two groups of 27 patients: one received usual management (diet, exercise, and insulin), whereas the other received 500 mL of camel milk daily in addition to standard management. A control group of 10 healthy subjects was also assessed. The following parameters were evaluated at baseline and at 4 and 16 weeks: hemoglobin A1c (HbA1c), human C-peptide, lipid profile, serum insulin, anti-insulin antibodies, creatinine clearance, albumin in 24-hour urine, body mass index, and Diabetes Quality of Life score. The following parameters were significantly different between the usual-management group versus the camel milk group after 16 weeks: fasting blood sugar ($227.2\;{\pm}\;17.7$ vs. $98.9\;{\pm}\;16.2\;mg/dL$), HbA1c ($9.59\;{\pm}\;2.05$[%] vs. $7.16\;{\pm}\;1.84$[%]), serum anti-insulin antibodies ($26.20\;{\pm}\;7.69$ vs. $20.92\;{\pm}\;5.45\;{\mu}U/mL$), urinary albumin excretion ($25.17\;{\pm}\;5.43$ vs. $14.54\;{\pm}\;5.62\;mg/dL$/24 hours), daily insulin dose ($48.1\;{\pm}\;6.95$ vs. $23\;{\pm}\;4.05$ units), and body mass index ($18.43\;{\pm}\;3.59$ vs. $24.3\;{\pm}\;2.95\;kg/m^2$). Most notably, C-peptide levels were markedly higher in the camel milk group ($0.28\;{\pm}\;0.6$ vs. $2.30\;{\pm}\;0.51\;pmol/mL$). These results suggest that, as an adjunct to standard management, daily ingestion of camel milk can aid metabolic control in young type 1 diabetics, at least in part by boosting endogenous insulin secretion.

Camel Milk as an Adjuvant Therapy for the Treatment of Type 1 Diabetes: Verification of a Traditional Ethnomedical Practice

Ragaa Hosny Mohamad,Zekry Khalid Zekry,Hussain A. Al-Mehdar,Omar Salama,Siad Ebrahim El-Shaieb,Amany A. El-Basmy,Mohamad Gamil Abdel Monem Al-said,Sabry Mohamed Sharawy 한국식품영양과학회 2009 Journal of medicinal food Vol.12 No.2

There is a traditional belief in the Middle East that regular consumption of camel milk may aid in prevention and control of diabetes. The aim of this work was to evaluate the efficacy of camel milk as an adjuvant therapy in young type 1 diabetics. This 16-week randomized study enrolled 54 type 1 diabetic patients (average age 20 years) selected from those attending the outpatient diabetes clinic of the Menofia University Hospital, affiliated with Egypt's National Cancer Institute. Subjects were randomly divided into two groups of 27 patients: one received usual management (diet, exercise, and insulin), whereas the other received 500 mL of camel milk daily in addition to standard management. A control group of 10 healthy subjects was also assessed. The following parameters were evaluated at baseline and at 4 and 16 weeks: hemoglobin A1c (HbA1c), human C-peptide, lipid profile, serum insulin, anti-insulin antibodies, creatinine clearance, albumin in 24-hour urine, body mass index, and Diabetes Quality of Life score. The following parameters were significantly different between the usual-management group versus the camel milk group after 16 weeks: fasting blood sugar (227.2 ± 17.7 vs. 98.9 ± 16.2 mg/dL), HbA1c (9.59 ± 2.05[%] vs. 7.16 ± 1.84[%]), serum anti-insulin antibodies (26.20 ± 7.69 vs. 20.92 ± 5.45 μU/mL), urinary albumin excretion (25.17 ± 5.43 vs. 14.54 ± 5.62 mg/dL/24 hours), daily insulin dose (48.1 ± 6.95 vs. 23 ± 4.05 units), and body mass index (18.43 ± 3.59 vs. 24.3 ± 2.95 kg/m2). Most notably, C-peptide levels were markedly higher in the camel milk group (0.28 ± 0.6 vs. 2.30 ± 0.51 pmol/mL). These results suggest that, as an adjunct to standard management, daily ingestion of camel milk can aid metabolic control in young type 1 diabetics, at least in part by boosting endogenous insulin secretion.

LEF1-mediated MMP13 gene expression is repressed by SIRT1 in human chondrocytes

Elayyan, Jinan,Lee, Eun-Jin,Gabay, Odile,Smith, Christopher A.,Qiq, Omar,Reich, Eli,Mobasheri, Ali,Henrotin, Yves,Kimber, Susan J.,Dvir-Ginzberg, Mona The Federation of American Societies for Experimen 2017 The FASEB Journal Vol.31 No.7

<P>Reduced SIRT1 activity and levels during osteoarthritis (OA) promote gradual loss of cartilage. Loss of cartilage matrix is accompanied by an increase in matrix metalloproteinase (MMP) 13, partially because of enhanced LEF1 transcriptional activity. In this study, we assessed the role of SIRT1 in LEF1-mediated MMP13 gene expression in human OA chondrocytes. Results showed that MMP13 protein levels and enzymatic activity decreased significantly during SIRT1 overexpression or activation by resveratrol. Conversely, MMP13 gene expression was reduced in chondrocytes transfected with SIRT1 siRNA or treated with nicotinamide (NAM), a sirtuin inhibitor. Chondrocytes challenged with IL-113, a cytokine involved in OA pathogenesis, enhanced LEF1 protein levels and gene expression, resulting in increased MMP13 gene expression; however, overexpression of SIRT1 during IL-113 challenge impeded LEF1 levels and MMP13 gene expression. Previous reports showed that LEF1 binds to the MMP13 promoter and transactivates its expression, but we observed that SIRT1 repressed LEF1 protein and mRNA expression, ultimately reducing LEF1 transcriptional activity, as judged by luciferase assay. Finally, mouse articular cartilage from Sirt1-/presented increased LEF1 and MMP13 protein levels, similar to human OA cartilage. Thus, demonstrating for the first time that SIRT1 represses MMP13 in human OA chondrocytes, which appears to be mediated, at least in part, through repression of the transcription factor LEF1, a known modulator of MMP13 gene expression. Elayyan, J., Lee, E.-J., Gabay, O., Smith, C. A., Qiq, O., Reich, E., Mobasheri, A., Henrotin, Y., Kimber, S. J., Dvir-Ginzberg, M. LEF1-mediated MMP13 gene expression is repressed by SIRT1 in human chondrocytes.</P>

Fabrication of highly hydrophilic tubular type perlite membrane support

Omar A. Al-Harbi,Cem ÖZGÜR,M. M Khan 한양대학교 세라믹연구소 2016 Journal of Ceramic Processing Research Vol.17 No.4

We fabricated and characterized a highly hydrophilic membrane support using only perlite as an ore without altering itschemical and physical properties. Tubular-type microfiltration supports were fabricated by an extrusion technique. Plasticperlite paste was obtained by adding organic additives and water. The extruded samples were carefully dried to prevent cracksduring the drying period of 6 days with a controlled drying temperature and humidity. Green bodies were sintered attemperatures of 1000 oC, 1025 oC, and 1050 oC for 1, 3, and 6 hours. Tubular membrane supports were characterized in termsof microstructure, porosity, pore size distribution and crystalline phases. Additionally, the hydrophilicity of the samples wasdetermined by a thin layer wicking (TLW) approach. The water contact angles of the samples sintered at 1025 oC for 3 hourswere determined to be 20 o, and the porosity and mean pore size of the sample were 23.54% and 13 µm, respectively. The cleanwater permeability of the sample was 10.677 L/h.m2bar. According to the results, the obtained sample functions well as a highlyhydrophilic membrane support, and it is also a good candidate for a filter used in macro- and microfiltration processes. Filtration tests indicated that the median particle size of the solids in waste water is 500 nm, with a turbidity of 100 NTU, andthe waste water can be cleaned by the newly fabricated perlite tubular ceramics up to a turbidity level of 0.35 NTU, whichis acceptable in various industries

Study of Dynamic Behaviors in a Spin Valve System Modeled by the Landau-Lifshitz-Slonczewski Equation

Javier A. Velez,Edward Mosso,Omar J. Suarez 한국자기학회 2019 Journal of Magnetics Vol.24 No.3

In this work, the dynamic behavior of a spin valve oscillator with a Nickel-free layer, modeled by the Landau-Lifshitz-Slonczewski equation is studied. It is considered a constant applied field and a spin current with two components, a constant term and a term with a time-dependent harmonic modulation. Techniques to characterize dynamic behaviors of systems, such as Lyapunov exponents, bifurcation diagram, phase portraits, time series, and Fourier spectra were used. It is demonstrated that the system presents multiple transitions between chaotic and regular states when the constant magnetic field, the magnitude, and frequency of the alternating current are varied. Furthermore, it is found that the effect of the magnetic field and the amplitude of the currents play a meaningful role in the chaotic behavior start.

Hybrid Electrically Conductive Adhesive (HECA) Properties as a Function of Hybrid Filler Ratio With Increasing Total Filler Loading

Z. Adnan,S. H. S. M. Fadzullah,G. Omar,Z. Mustafa,M. B. Ramli,N. Razali,A. A. Kamarolzaman 대한금속·재료학회 2021 ELECTRONIC MATERIALS LETTERS Vol.17 No.4

This paper presents a study on Hybrid Electrically Conductive Adhesive (HECA) properties as an in-depth analysis regardinghybrid fi ller ratio at low fi ller range. It is well established that the hybridization approach exhibits excellent functionalproperties of HECA. Still, the highest potential ability of the proposed HECA concerning relative amounts of involvingfi llers is the least being discovered. In this work, silver micro-fl ake (AgMF) and multiwalled carbon nanotube (MWCNT)conductive fi llers were incorporated from 3 to 15 wt.%, while AgMF: MWCNT fi ller ratio is varied between 0.006 up to 0.2to choose the best combination. Here, a planetary centrifugal mixer with diff erent mixing time and sequence were consideredto identify the most eff ective mixing method. The functional properties of HECA were characterized in terms of a four-pointprobe electrical test and a lap shear test via tensile mode. The morphological study suggests that a shorter centrifugal mixingperiod allows an adequate dispersion of the micro-nano fi llers in the HECA system and revealed superior interfacial bondingbetween the fi llers at the optimum ratio. Interestingly, electrical resistivity at critical concentration showed an optimumratio by incorporating only 2.5% AgMF in the hybrid fi llers to yield a 42.62% reduction. However, the signifi cant eff ects ofhybridization are observed until the percolation threshold of HECA at 9 wt% only, followed by a 38.5% reduction beyondthis limit. Moreover, the lap shear strength is most reliable at a total fi ller of 6 wt%, an indication of an excellent fi ller-binderload distribution.

Recommendations for Improved Welding Procedures for Thick Steel Plates Through Thermo-Mechanical Analysis

Omar A. Ibrahim,Dimitrios G. Lignos,Colin A. Rogers 한국강구조학회 2019 International Journal of Steel Structures Vol.19 No.1

Welding of steel plates is accompanied by residual stresses that increase as the constraint provided by the welded components becomes greater. Consequently, crack initiation has been reported after welding thick plates due to the high residual stresses developed by the welding procedure. This is further exacerbated by the higher likelihood of imperfections present in thick steel plates due to the rolling and cooling process. The research described herein aims to develop improved submerged arc welding (SAW) procedures to reduce the residual stresses for steel plates of thickness > 50 mm. Acceptance criteria are developed for discontinuities present in the steel plates prior to welding, to limit the probability of crack initiation. A parametric study of SAW procedure parameters was conducted utilizing a validated fi nite element model. Two welding procedures were recommended for thick steel plates. Discontinuity acceptance limits were also recommended for each welding procedure using a fracture toughness database and an expression developed to calculate the probability of a crack to initiate.