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Träfflista för sökning "WFRF:(Taher M) "

Sökning: WFRF:(Taher M)

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1.
  • 2021
  • swepub:Mat__t
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  • Thomas, HS, et al. (författare)
  • 2019
  • swepub:Mat__t
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  • Tabiri, S, et al. (författare)
  • 2021
  • swepub:Mat__t
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  • Bravo, L, et al. (författare)
  • 2021
  • swepub:Mat__t
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  • Kanai, M, et al. (författare)
  • 2023
  • swepub:Mat__t
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  • Drake, TM, et al. (författare)
  • Surgical site infection after gastrointestinal surgery in children: an international, multicentre, prospective cohort study
  • 2020
  • Ingår i: BMJ global health. - : BMJ. - 2059-7908. ; 5:12
  • Tidskriftsartikel (refereegranskat)abstract
    • Surgical site infection (SSI) is one of the most common healthcare-associated infections (HAIs). However, there is a lack of data available about SSI in children worldwide, especially from low-income and middle-income countries. This study aimed to estimate the incidence of SSI in children and associations between SSI and morbidity across human development settings.MethodsA multicentre, international, prospective, validated cohort study of children aged under 16 years undergoing clean-contaminated, contaminated or dirty gastrointestinal surgery. Any hospital in the world providing paediatric surgery was eligible to contribute data between January and July 2016. The primary outcome was the incidence of SSI by 30 days. Relationships between explanatory variables and SSI were examined using multilevel logistic regression. Countries were stratified into high development, middle development and low development groups using the United Nations Human Development Index (HDI).ResultsOf 1159 children across 181 hospitals in 51 countries, 523 (45·1%) children were from high HDI, 397 (34·2%) from middle HDI and 239 (20·6%) from low HDI countries. The 30-day SSI rate was 6.3% (33/523) in high HDI, 12·8% (51/397) in middle HDI and 24·7% (59/239) in low HDI countries. SSI was associated with higher incidence of 30-day mortality, intervention, organ-space infection and other HAIs, with the highest rates seen in low HDI countries. Median length of stay in patients who had an SSI was longer (7.0 days), compared with 3.0 days in patients who did not have an SSI. Use of laparoscopy was associated with significantly lower SSI rates, even after accounting for HDI.ConclusionThe odds of SSI in children is nearly four times greater in low HDI compared with high HDI countries. Policies to reduce SSI should be prioritised as part of the wider global agenda.
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11.
  • El-Seedi, Hesham R., et al. (författare)
  • Cardenolides : Insights from chemical structure and pharmacological utility
  • 2019
  • Ingår i: Pharmacological Research. - : Academic Press. - 1043-6618 .- 1096-1186. ; 141, s. 123-175
  • Tidskriftsartikel (refereegranskat)abstract
    • Cardiac glycosides (CGs) are a class of naturally occurring steroid-like compounds, and members of this class have been in clinical use for more than 1500 years. They have been used in folk medicine as arrow poisons, abortifacients, heart tonics, emetics, and diuretics as well as in other applications. The major use of CGs today is based on their ability to inhibit the membrane-bound Na + /K + -ATPase enzyme, and they are regarded as an effective treatment for congestive heart failure (CHF), cardiac arrhythmia and atrial fibrillation. Furthermore, increasing evidence has indicated the potential cytotoxic effects of CGs against various types of cancer. In this review, we highlight some of the structural features of this class of natural products that are crucial for their efficacy, some methods of isolating these compounds from natural resources, and the structural elucidation tools that have been used. We also describe their physicochemical properties and several modern biotechnological approaches for preparing CGs that do not require plant sources.
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12.
  • El-Seedi, H. R., et al. (författare)
  • Hydroxycinnamic Acids : Natural Sources, Biosynthesis, Possible Biological Activities, and Roles in Islamic Medicine
  • 2017
  • Ingår i: Studies in Natural Products Chemistry. - : Elsevier B.V.. ; , s. 1-29
  • Bokkapitel (refereegranskat)abstract
    • Hydroxycinnamic acids are the most widely distributed phenolic acids in plants. Broadly speaking, they can be defined as compounds derived from cinnamic acid. They are present at high concentrations in many food products, including fruits, vegetables, tea, cocoa, and wine. Cinnamic acid has received great attention in oriental research where it has been used as an antioxidant in food additives in Asia and especially in medical studies in China after being proven to be an effective component of medicinal herbs used by traditional medicine. Cinnamic acid is a phenolic acid widely distributed in the plant kingdom. It presents a wide range of potential therapeutic effects useful in the treatments of cancer, diabetes, lung, and cardiovascular diseases, as well as hepatic, neuro-, and photoprotective effects and antimicrobial and antiinflammatory activities. Overall, the pharmaceutical potential of cinnamic acid can be attributed to its ability to scavenge free radicals. However, recent studies have revealed that cinnamic acid presents pharmacological properties beyond those related to its antioxidant activity, such as the ability to competitively inhibit HMG-CoA reductase and activate glucokinase, contributing to reduce hypercholesterolemia and hyperglycemia, respectively. A diet rich in hydroxycinnamic acids is thought to be associated with beneficial health effects such as a reduced risk of cardiovascular disease. The impact of hydroxycinnamic acids on health depends on their intake and pharmacokinetic properties. It can be found free, dimerized or esterified with proteins and polysaccharides in the cell wall, such as arabinoxylans in grasses and xyloglucans in bamboo. Cinnamic acid is an important biological and structural component of the plant cell wall. Due to its ability to stop radical chain reactions by resonance followed by polymerization, cinnamic acid offers protection against UV radiation and is responsible for cross-linking polysaccharides and other cell wall polymers. Cinnamic acid can be absorbed by the small intestine and excreted in the urine, where therapeutic efficacy is dependent on its physiological concentrations and pharmacokinetic properties, which include absorption, distribution, metabolism, and excretion of metabolites. Mass spectrometry (MS) and nuclear magnetic resonance (NMR) spectroscopy, especially 2D NMR (COSY, NOESY, HMQC, and HMBC), are the most useful analytical techniques for the structural elucidation of hydroxycinnamic acids besides UV, IR, CD, X-ray analysis, and chemical degradation. In this chapter, we update the reader about the therapeutic properties of cinnamic acid, reviewing its dietary sources, the pharmacokinetic profile, antioxidant action mechanisms, and therapeutic effects in the treatment and prevention of various diseases, in order to provide a basis for understanding its pharmaceutical potential.
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13.
  • Sayed, Abdelwahed R., et al. (författare)
  • One-Pot Synthesis of Novel Thiazoles as Potential Anti-Cancer Agents
  • 2020
  • Ingår i: Drug Design, Development and Therapy. - 1177-8881. ; 14, s. 1363-1375
  • Tidskriftsartikel (refereegranskat)abstract
    • Background: Thiazole and thiosemicarbazone derivatives are known to have potential anticancer activity with a mechanism of action related to inhibition of matrix metallo-proteinases, kinases and anti-apoptotic BCL2 family proteins.Materials and Methods: A novel three series of 5-(1-(2-(thiazol-2-yl)hydrazono)ethyl) thiazole derivatives were prepared in a one-pot three-component reaction using 2-(2-benzylidene hydrazinyl)-4-methylthiazole as a starting precursor. MS, IR, H-1-NMR and C-13-NMR were used to elucidate the structures of the synthesized compounds. Most of the synthesized products were evaluated for their in vitro anticancer screening against HCT-116, HT-29 and HepG2 using the MTT colorimetric assay.Results: The results indicated that compounds 4c, 4d and 8c showed growth inhibition activity against HCT-116 with IC50 values of 3.80 +/- 0.80, 3.65 +/- 0.90 and 3.16 +/- 0.90 mu M, respectively, compared to harmine (IC50 = 2.40 +/- 0.12 mu M) and cisplatin (IC50 = 5.18 +/- 0.94 mu M) reference drugs. Also, compounds 8c, 4d and 4c showed promising IC(50 )values of 3.47 +/- 0.79, 4.13 +/- 0.51 and 7.24 +/- 0.62 mu M, respectively, against the more resistant human colorectal cancer (HT-29) cell line compared with harmine (IC50 = 4.59 +/- 0.67 mu M) and cisplatin (IC50 = 11.68 +/- 1.54 mu M). On the other hand, compounds 4d, 4c, 8c and llc were the most active (IC50 values of 2.31 +/- 0.43, 2.94 +/- 0.62, 4.57 +/- 0.85 and 9.86 +/- 0.78 mu M, respectively) against the hepatocellular carcinoma (HepG2) cell line compared with harmine (IC50 = 2.54 +/- 0.82 mu M) and cisplatin (IC50 = 41 +/- 0.63 pM). The study also suggested that the mechanism of the anticancer action exerted by the most active compounds (4c, 4d and 8c) inside HCT-116 cells was apoptosis through the Bcl-2 family.Conclusion: Thiazole scaffolds 4c, 4d and 8c showed anticancer activities in the micromolar range and are appropriate as a candidate for cancer treatment.
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14.
  • El Serafi, Ibrahim Taher, et al. (författare)
  • Effect of interleukin-6 and insulin resistance on early virological response of Egyptian chronic hepatitis C patients to combined pegylated interferon plus ribavirin therapy
  • 2013
  • Ingår i: Egyptian Liver Journal. - Heidelberg, Germany : Wolters Kluwer. - 2090-6218. ; 3:2, s. 21-27
  • Tidskriftsartikel (refereegranskat)abstract
    • Background and aim: Response to hepatitis C virus (HCV)-specific therapy is variable but might be influenced by host factors. We studied whether interleukin-6 (IL-6) level, IL-6–174G>C gene polymorphism, and insulin resistance affect the response to antiviral treatment in HCV-infected patients.Patients and methods: Fifty-five chronic hepatitis C patients and 13 healthy individuals as controls were included in this study. Liver function tests, HCV RNA titer, ultrasonography, and histopathological examination of liver tissues were performed for all patients. Pretreatment plasma IL-6 levels and homeostasis model assessment-insulin resistance were estimated. The IL-6–174G>C polymorphism was detected by the PCR/RFLP method. After 12 weeks of combined pegylated interferon-α and ribavirin therapy, patients were classified into responders or nonresponders according to whether they achieved an early virological response.Results: The responders had significantly high IL-6 levels (P=0.01), low mean stage of fibrosis (P=0.03), and low viral load (P=0.04) compared with nonresponders. Although not significant, patients with the IL-6–174 CC genotype reported a higher response rate (81%) compared with those with the CG genotype (50%) and GG genotype (62%). IL-6 level at a cutoff point of 2.15 pg/ml had 81.1% sensitivity and 72.7% specificity and showed significant relation with early virological response (P=0.04).Conclusion: Estimation of basal IL-6 level could be used as a predictor of response to pegylated interferon-α and ribavirin therapy in CHC patients.
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17.
  • Ramadan, Wafaa S, et al. (författare)
  • Interplay between Epigenetics, Expression of Estrogen Receptor- α, HER2/ERBB2 and Sensitivity of Triple Negative Breast Cancer Cells to Hormonal Therapy
  • 2018
  • Ingår i: Cancers. - : MDPI. - 2072-6694. ; 11:1, s. 13-13
  • Tidskriftsartikel (refereegranskat)abstract
    • Triple negative breast cancer (TNBC) cells are resistant to hormonal/targeted therapies. This study aims to investigate epigenetic differences between TNBC and other types of breast cancer and the effect of epigenetic modulation on the response of TNBC cells to hormonal therapy. Thus, we investigated (i) the expression of different epigenetic markers, (ii) the effect of epigenetic modifying agents on the expression of ERα and HER2/ERBB2 and (iii) the effect on the response to tamoxifen in four breast cancer cell lines with different hormonal receptor status. Our results revealed a differential expression patterns of epigenetic markers in the four breast cancer cells. In TNBC cells, histone deacetylases (HDAC) 1 and 2 were less expressed, whereas HDACs 4 and 6 were overexpressed. Interestingly, treatment with epigenetic modifiers resulted in (i) a pronounced increase in the expression of ERα and HER2/ERBB2 along with (ii) an increase in the sensitivity of TNBC cells to tamoxifen. Collectively, this study indicates a different epigenetic background for TNBC cells, which represses the expression of ERα and HER2/ERBB2. Furthermore, we provide here the rationale for the use of epigenetic modifiers to enhance the response of TNBC to hormonal therapy through upregulation of ERα.
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18.
  • Ahmed, Mohamed R., et al. (författare)
  • Correlation between dyslipidemia and severity of allergic rhinitis
  • 2018
  • Ingår i: The Egyptian Journal of Otolaryngology. - London, United Kingdom : Springer. - 1012-5574 .- 2090-8539. ; 34:2, s. 111-115
  • Tidskriftsartikel (refereegranskat)abstract
    • Background Allergic rhinitis is a common problem affecting between 20 and 25% of the population lowering the quality of life (QOL) more than any other disease. Dyslipidemia is known to impact potently the development of atopy as it promotes proatopic Th2 immunity and allergic inflammation.Objective The aim was to test the correlation between severity of allergic rhinitis and dyslipidemia.Materials and methods A comparative study carried out on 350 allergic rhinitis patients were subjected to full serum lipid assays, visual analog scale assessing their nasal symptoms, and QOL assessment using a seven-point scale.ResultsPatients were divided into two groups (according to their lipid profile): abnormal dyslipidemia group (33%) and normal lipid profile group (67%).The abnormal dyslipidemia group showed a more intense allergic rhinitis symptoms compared with the normal lipid profile with poor QOL score (1.97).ConclusionDyslipidemia might play an important role in increasing the severity of allergic rhinitis symptoms with impaired patients’ QOL; therefore, its control could achieve better treatment outcomes. 
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19.
  • Al Banna, Md. Hasan, et al. (författare)
  • Attention-based Bi-directional Long-Short Term Memory Network for Earthquake Prediction
  • 2021
  • Ingår i: IEEE Access. - : IEEE. - 2169-3536. ; 9, s. 56589-56603
  • Tidskriftsartikel (refereegranskat)abstract
    • An earthquake is a tremor felt on the surface of the earth created by the movement of the major pieces of its outer shell. Till now, many attempts have been made to forecast earthquakes, which saw some success, but these attempted models are specific to a region. In this paper, an earthquake occurrence and location prediction model is proposed. After reviewing the literature, long short-term memory (LSTM) is found to be a good option for building the model because of its memory-keeping ability. Using the Keras tuner, the best model was selected from candidate models, which are composed of combinations of various LSTM architectures and dense layers. This selected model used seismic indicators from the earthquake catalog of Bangladesh as features to predict earthquakes of the following month. Attention mechanism was added to the LSTM architecture to improve the model’s earthquake occurrence prediction accuracy, which was 74.67%. Additionally, a regression model was built using LSTM and dense layers to predict the earthquake epicenter as a distance from a predefined location, which provided a root mean square error of 1.25.
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20.
  • Banna, Md. Hasan Al, et al. (författare)
  • A Hybrid Deep Learning Model to Predict the Impact of COVID-19 on Mental Health from Social Media Big Data
  • 2023
  • Ingår i: IEEE Access. - : Institute of Electrical and Electronics Engineers (IEEE). - 2169-3536. ; 11, s. 77009-77022
  • Tidskriftsartikel (refereegranskat)abstract
    • The novel coronavirus disease (COVID-19) pandemic is provoking a prevalent consequence on mental health because of less interaction among people, economic collapse, negativity, fear of losing jobs, and death of the near and dear ones. To express their mental state, people often are using social media as one of the preferred means. Due to reduced outdoor activities, people are spending more time on social media than usual and expressing their emotion of anxiety, fear, and depression. On a daily basis, about 2.5 quintillion bytes of data are generated on social media. Analyzing this big data can become an excellent means to evaluate the effect of COVID-19 on mental health. In this work, we have analyzed data from Twitter microblog (tweets) to find out the effect of COVID-19 on people’s mental health with a special focus on depression. We propose a novel pipeline, based on recurrent neural network (in the form of long short-term memory or LSTM) and convolutional neural network, capable of identifying depressive tweets with an accuracy of 99.42%. Preprocessed using various natural language processing techniques, the aim was to find out depressive emotion from these tweets. Analyzing over 571 thousand tweets posted between October 2019 and May 2020 by 482 users, a significant rise in depressing tweets was observed between February and May of 2020, which indicates as an impact of the long ongoing COVID-19 pandemic situation.
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21.
  • Baryawno, Ninib, et al. (författare)
  • Detection of human cytomegalovirus in medulloblastomas reveals a potential therapeutic target
  • 2011
  • Ingår i: Journal of Clinical Investigation. - 0021-9738 .- 1558-8238. ; 121:10, s. 4043-4055
  • Tidskriftsartikel (refereegranskat)abstract
    • Medulloblastomas are the most common malignant brain tumors in children. They express high levels of COX-2 and produce PGE(2), which stimulates tumor cell proliferation. Human cytomegalovirus (HCMV) is prevalent in the human population and encodes proteins that provide immune evasion strategies and promote oncogenic transformation and oncomodulation. In particular, HCMV induces COX-2 expression; STAT3 phosphorylation; production of PGE2, vascular endothelial growth factor, and IL-6; and tumor formation in vivo. Here, we show that a large proportion of primary medulloblastomas and medulloblastoma cell lines are infected with HCMV and that COX-2 expression, along with PGE2 levels, in tumors is directly modulated by the virus. Our analysis indicated that both HCMV immediate-early proteins and late proteins are expressed in the majority of primary medulloblastomas. Remarkably, all of the human medulloblastoma cell lines that we analyzed contained HCMV DNA and RNA and expressed HCMV proteins at various levels in vitro. When engrafted into immunocompromised mice, human medulloblastoma cells induced expression of HCMV proteins. HCMV and COX-2 expression correlated in primary tumors, cell lines, and medulloblastoma xenografts. The antiviral drug valganciclovir and the specific COX-2 inhibitor celecoxib prevented HCMV replication in vitro and inhibited PGE2 production and reduced medulloblastoma tumor cell growth both in vitro and in vivo. Ganciclovir did riot affect the growth of HCMV-negative tumor cell lines. These findings imply an important role for HCMV in medulloblastoma and suggest HCMV as a novel therapeutic target for this tumor.
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22.
  • Braceras, Inigo, et al. (författare)
  • On the electro-tribological properties and degradation resistance of silver-aluminum coatings
  • 2018
  • Ingår i: Wear. - : ELSEVIER SCIENCE SA. - 0043-1648 .- 1873-2577. ; 414, s. 202-211
  • Tidskriftsartikel (refereegranskat)abstract
    • Contact materials in sliding electrical applications must possess low electrical contact resistance, low friction and wear coefficients, and high degradation resistance to the surrounding media. Silver coatings are commonly used in such applications despite their shortcomings. This work has focused on the study of alternative silver-aluminum coatings deposited by PVD. The main findings include the strong dependence of the tribological performance on the concentration of Al and hence the phases present in the coatings. Besides, the wear mechanism was found to be affected by the working media, either on air or insulating oil. Results have shown that for full HCP phase coatings (Ag67Al33), wear rates are lowest, with no adhesive wear and good surface sulphidation resistance, though with some proclivity to oxidation, coupled with a moderate increase in the electrical contact resistance.
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23.
  • El-Awady, Raafat A, et al. (författare)
  • Epigenetics and miRNA as predictive markers and targets for lung cancer chemotherapy
  • 2015
  • Ingår i: Cancer Biology & Therapy. - Philadelphia, PA, United States : Taylor & Francis. - 1538-4047 .- 1555-8576. ; 16:7, s. 1056-1070
  • Tidskriftsartikel (refereegranskat)abstract
    • Lung cancer cells show inherent and acquired resistance to chemotherapy. The lack of good predictive markers/novel targets and the incomplete understanding of the mechanisms of resistance limit the success of lung cancer response to chemotherapy. In the present study, we used an isogenic pair of lung adenocarcinoma cell lines; A549 (wild-type) and A549DOX11 (doxorubicin resistant) to study the role of epigenetics and miRNA in resistance/response of non-small cell lung cancer (NSCLC) cells to doxorubicin. Our results demonstrate differential expression of epigenetic markers whereby the level of HDACs 1, 2, 3 and4, DNA methyltransferase, acetylated H2B and acetylated H3 were lower in A549DOX11 compared to A549 cells. Fourteen miRNAs were dys-regulated in A549DOX11 cells compared to A549 cells, of these 14 miRNAs, 4 (has-mir-1973, 494, 4286 and 29b-3p) have shown 2.99 – 4.44 fold increase in their expression. This was associated with reduced apoptosis and higher resistance of A549DOX11cells to doxorubicin and etoposide. Sequential treatment with the epigenetic modifiers trichostatin A or 5-aza-2'-deoxycytidine followed by doxorubicin resulted in: (i) enhanced sensitivity of both cell lines to doxorubicin especially at low concentrations, (ii) enhanced doxorubicin-induced DNA damage in both cell lines, (iii) dysregulation of some miRNAs in A549 cells. In conclusion, A549DOX11 cells resistant to DNA damaging drugs have epigenetic profile and miRNA expression different from the sensitive cells. Moreover, epigenetic modifiers may reverse the resistance of certain NSCLC cells to DNA damaging agents by enhancing induction of DNA damage. This may open the door for using epigenetic profile/miRNA expression of some cancer cells as resistance markers/targets to improve response of resistant cells to doxorubicin and for the use of combination doxorubicin/epigenetic modifiers to reduce doxorubicin toxicity.
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24.
  • El-Huneidi, Waseem, et al. (författare)
  • Micromeria fruticosa Induces Cell Cycle Arrest and Apoptosis in Breast and Colorectal Cancer Cells
  • 2020
  • Ingår i: Pharmaceuticals. - : MDPI. - 1424-8247. ; 13:6
  • Tidskriftsartikel (refereegranskat)abstract
    • Micromeria fruticosa (L.) Druce subs p.serpyllifolia (Lamiaceae) has been used widely in folk medicine to alleviate various ailments such as abdominal pains, diarrhea, colds, eye infections, heart disorders and wounds. A few reports have confirmed different therapeutic potentialities of its extracts, including the anti-inflammatory, gastroprotective, analgesic, antiobesity and antidiabetic activities. This study aimed to investigate the mechanistic pathway of the antiproliferative activity of the ethanolic extract ofM. fruticosaon two different cancer cell lines, namely human breast (mammary carcinoma F7 (MCF-7)) and human colorectal (human colon tumor cells (HCT-116)) cell lines. The 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide tetrazolium (MTT) assay, Annexin V-FITC/PI, caspases 8/9 and cell cycle analyses, qRT-PCR and Western blot were used to assess the effect of M. fruticosaon cytotoxicity, apoptosis, cell cycle, cell cycle-related genes and protein expression profiles in MCF-7 and HCT-116. The extract inhibits cell proliferation in a time- and dose-dependent manner. The half-maximal inhibitory concentration (IC50) for both cell lines was found to be 100 mu g/mL. Apoptosis induction was confirmed by Annexin V-FITC/PI, that was related to caspases 8 and 9 activities induction. Furthermore, the cell cycle analysis revealed arrest at G2/M phase. The underlying mechanism involved in the G2/M arrest was found to be associated with the downregulation of CDK1, cyclin B1 and survivin that was confirmed by qRT-PCR and Western blotting.
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25.
  • El-Serafi, Ahmed Taher, 1977-, et al. (författare)
  • Dysregulation of male sex hormones in chronic hepatitis C patients
  • 2016
  • Ingår i: Andrologia. - Berlin, Germany : Wiley-Blackwell. - 0303-4569 .- 1439-0272. ; 48:1, s. 82-86
  • Tidskriftsartikel (refereegranskat)abstract
    • Chronic hepatitis C (HCV) infection is a serious problem all over the world and has a special importance in Egypt, where the prevalence of infection is 14.7% of population. In males, HCV is associated with sexual dysfunction and changes in the semen parameters. This study aimed at estimation of a panel of the most important related hormones in the serum of patients and illustration of their correlation to the routine laboratory investigations. The four studied hormones showed alteration in the patients in comparison with the controls. While androstenedione, prolactin and testosterone were significantly increased in patients, dehydroepiandrosterone sulphate was decreased. These changes in the hormones were not related to the liver functions, pathological grade or even viral load. We hypothesised a model of how HCV can induce these hormonal changes and recommended to add these hormones to the follow-up panel of male patients with HCV.
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26.
  • Endrias, Dawit H., et al. (författare)
  • A combinatorial optimization approach for evaluating minimum-zone spatial straightness errors
  • 2012
  • Ingår i: Measurement. - : Elsevier. - 0263-2241 .- 1873-412X. ; 45:5, s. 1170-1179
  • Tidskriftsartikel (refereegranskat)abstract
    • This paper presents a new and robust approach for the accurate evaluation of minimumzone spatial straightness error from a set of coordinate measurement data points. The algorithm iteratively searches for the specific data points that define the minimum bound of the spatial straightness zone using combinatorial optimization. It is based on the fact that the minimum circumscribed cylinder of a point set, which is equivalent to the minimum spatial straightness zone of the measurement data, will pass through three, four, or five of the data points that constitute the convex hull vertices of the entire data set. Computed results have shown that although the presented approach may lead to increased computational time, it is robust and able to construct the exact minimum circumscribed cylinder for a given point set. The minimum-zone spatial straightness error can thus be evaluated with the best possible accuracy. The advantage of the presented algorithm is demonstrated via comparison with published computed results of existing algorithms.
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27.
  • Filippov, A., et al. (författare)
  • NMR self-diffusion study of a phosphonium bis(mandelato)borate ionic liquid
  • 2013
  • Ingår i: Physical Chemistry, Chemical Physics - PCCP. - : Royal Society of Chemistry (RSC). - 1463-9076 .- 1463-9084. ; 15:23, s. 9281-9287
  • Tidskriftsartikel (refereegranskat)abstract
    • Newly synthesised halogen-free boron based ionic liquids (hf-BILs) composed of chelated orthoborate anions and phosphonium cations have hydrolytic stability, low melting point and outstanding wear and friction reducing properties. We report here the peculiarities of self-diffusion in one representative from this class, trihexyltetradecylphosphonium bis(mandelato)borate, [P6,6,6,14][BMB], in the temperature range of its practical interest, 20-100 °C. NMR techniques demonstrated complicated diffusional behaviour-the ionic liquid can exist in one or two liquid "phases". In the low-temperature range (20-50 °C), two phases coexist where the cations, [P6,6,6,14], are contained mainly in the phase with slower diffusion coefficients while the anions, [BMB], are in the phase with faster diffusion coefficients. Cations have lower diffusion coefficients with a factor of 20 as compared with the anions, an effect which is caused by aggregation of cations into domains due to so-called "hydrophobic interaction" of their hydrocarbon chains. As the temperature rises above 60 °C, the two phases merge into one where both ions have equal diffusion coefficients. This is caused by thermal motion making the cation domains smaller in size and more easily interacting with anions. As a result, anions and cations diffuse in this high-temperature range as a pair.
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28.
  • Hussein, Mohammad H., et al. (författare)
  • Beta 2 -adrenergic receptor gene haplotypes and bronchodilator response in Egyptian patients with chronic obstructive pulmonary disease
  • 2017
  • Ingår i: Advances in Medical Sciences. - Warsaw, Poland : Elsevier. - 1896-1126 .- 1898-4002. ; 62:1, s. 193-201
  • Tidskriftsartikel (refereegranskat)abstract
    • Purpose: Chronic obstructive pulmonary disease (COPD) is a multi-factorial disorder caused by environmental determinants and genetic risk factors. Understanding the genetic predisposition of COPD is essential to develop personalized treatment regimens. Beta2-adrenergic receptor (ADRB2) gene polymorphisms have been implicated in the pathogenesis of obstructive pulmonary diseases. This study was conducted to assess the genetic association between Arg16Gly and Gln27Glu polymorphisms and COPD in the Egyptian patients, and to analyze their impact on the clinical outcome and therapeutic response.Patients/methods: The study population included 115 participants (61 COPD patients and 54 healthy controls) were genotyped for the Arg16Gly (rs1042713) and Gln27Glu (rs1042714) polymorphisms. Pulmonary function test was done and repeated in patients after salbutamol inhalation.Results: The Gly16 and Gln27 alleles represented 57% and 70% of the whole study population, and only 3 haplotypes were detected; Arg16/Gln27, Gly16/Gln27, and Gly16/Glu27. Genotypes and haplotypes homozygous for Arg16 and Gln27 were more likely to develop COPD (p<0.05). However, individuals carrying Glu27 allele conferred protection against COPD development (p=0.002). Furthermore, Arg16 genotypes and haplotypes were significantly associated with higher grades of dyspnea, more COPD symptoms and frequent exacerbations. In contrast, patients carrying Glu27 allele had better bronchial airway responsiveness to β2-agonists.Conclusions: Our findings suggested that the ADRB2 gene polymorphisms may have vital role in COPD risk, severity, and bronchodilator response among Egyptian population. Larger epidemiological studies are needed for results validation.
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29.
  • Ibrahim, G.H., et al. (författare)
  • Impact of Interleukin-28B gene polymorphism [rs12979860] on Egyptian patients infected with hepatitis C virus genotype-4
  • 2013
  • Ingår i: Eastern Mediterranean Health Journal. - Alexandria, Egypt : World Health Organization Regional Office for the Eastern Mediterranean (WHO/EMRO). - 1020-3397 .- 1687-1634. ; 19:Supp. 3, s. 98-104
  • Tidskriftsartikel (refereegranskat)abstract
    • Single nucleotide polymorphisms (SNPs) in the Interleukin (IL)-28B gene, namely rs12979860, could predict response to pegylated interferon-α-ribavirin (PR) therapy in hepatitis C virus genotype 1 (HCV-1)-infected patients. A similar role was investigated in a case-control study conducted on 93 Egyptian patients chronically infected with HCV-4 in comparison to 22 individuals with spontaneous HCV clearance and 70 healthy volunteers. The homozygous C allele genotype (CC) was associated with sustained viral response (SVR) to therapy compared with the homozygous T allele genotype (TT) and the heterozygous genotype (CT). In the SVR group, the response rate was statistically significantly higher in CC genotypes (58.6%) compared with CT/TT (20.3%). There was no correlation between SVR patients' genotypes and early response to therapy or HCV baseline viral load. Our findings describe how IL-28B SNP genotyping may guide appropriate selection of HCV-4-infected patients for PR therapy.
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30.
  • Jiang, Zheshun, et al. (författare)
  • Hexavalent chromium still a concern in Sweden : Evidence from a cross-sectional study within the SafeChrom project
  • 2024
  • Ingår i: International journal of hygiene and environmental health. - : Elsevier. - 1438-4639 .- 1618-131X. ; 256
  • Tidskriftsartikel (refereegranskat)abstract
    • ObjectivesHexavalent chromium (Cr(VI)) is classified as a human carcinogen. Occupational Cr(VI) exposure can occur during different work processes, but the current exposure to Cr(VI) at Swedish workplaces is unknown.MethodsThis cross-sectional study (SafeChrom) recruited non-smoking men and women from 14 companies with potential Cr(VI) exposure (n = 113) and controls from 6 companies without Cr(VI) exposure (n = 72). Inhalable Cr(VI) was measured by personal air sampling (outside of respiratory protection) in exposed workers. Total Cr was measured in urine (pre- and post-shift, density-adjusted) and red blood cells (RBC) (reflecting Cr(VI)) in exposed workers and controls. The Bayesian tool Expostats was used to assess risk and evaluate occupational exposure limit (OEL) compliance.ResultsThe exposed workers performed processing of metal products, steel production, welding, plating, and various chemical processes. The geometric mean concentration of inhalable Cr(VI) in exposed workers was 0.15 μg/m3 (95% confidence interval: 0.11–0.21). Eight of the 113 exposed workers (7%) exceeded the Swedish OEL of 5 μg/m3, and the Bayesian analysis estimated the share of OEL exceedances up to 19.6% for stainless steel welders. Median post-shift urinary (0.60 μg/L, 5th-95th percentile 0.10–3.20) and RBC concentrations (0.73 μg/L, 0.51–2.33) of Cr were significantly higher in the exposed group compared with the controls (urinary 0.10 μg/L, 0.06–0.56 and RBC 0.53 μg/L, 0.42–0.72). Inhalable Cr(VI) correlated with urinary Cr (rS = 0.64) and RBC-Cr (rS = 0.53). Workers within steel production showed the highest concentrations of inhalable, urinary and RBC Cr. Workers with inferred non-acceptable local exhaustion ventilation showed significantly higher inhalable Cr(VI), urinary and RBC Cr concentrations compared with those with inferred acceptable ventilation. Furthermore, workers with inferred correct use of respiratory protection were exposed to significantly higher concentrations of Cr(VI) in air and had higher levels of Cr in urine and RBC than those assessed with incorrect or no use. Based on the Swedish job-exposure-matrix, approximately 17 900 workers were estimated to be occupationally exposed to Cr(VI) today.ConclusionsOur study demonstrates that some workers in Sweden are exposed to high levels of the non-threshold carcinogen Cr(VI). Employers and workers seem aware of Cr(VI) exposure, but more efficient exposure control strategies are required. National strategies aligned with the European strategies are needed in order to eliminate this cause of occupational cancer.
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31.
  • Jiang, Zheshun, et al. (författare)
  • P-205 THE SAFECHROM PROJECT - EVIDENCE FROM A CROSS-SECTIONAL STUDY SHOWS THAT HEXAVALENT CHROMIUM IS STILL A CONCERN IN SWEDEN
  • 2024
  • Ingår i: Occupational Medicine. - 0962-7480. ; 74:Suppl 1, s. 291-292
  • Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
    • Hexavalent chromium Cr(VI) is a human carcinogen, but the current exposure to Cr(VI) at Swedish workplaces is unknown.Recruitment of 113 workers with potential Cr(VI) exposure and 72 controls was combined with measurements of inhalable Cr(VI) (only exposed workers) and total Cr in urine and red blood cells (RBC), Bayesian analysis of occupational exposure limit (OEL) compliance was used, as well as the Swedish job-exposure-matrix.Exposed workers performed processing of metal products, steel production, welding, and plating. The geometric mean concentration of inhalable Cr(VI) in exposed workers was 0.15 μg/m3. Eight workers (7\ exceeded the Swedish OEL (5 μg/m3), and the share of OEL exceedances was estimated to be up to 19.6\ and RBC-Cr were significantly higher in exposed workers compared with controls. Workers with inferred non-acceptable local exhaustion ventilation showed significantly higher inhalable Cr(VI), urine- and RBC-Cr than those with acceptable ventilation. Workers with inferred correct use of respiratory protection had higher inhalable Cr(VI), and, paradoxically, higher urine- and RBC-Cr concentrations than workers with incorrect use. We estimate that ~17 900 Swedish workers are occupationally exposed to Cr(VI) today.Our study showed that although most air measurements were relatively low, 7\ and particularly stainless steel workers are at risk for exceeding the OEL. The existing protective measures implemented at workplaces are still inadequate and insufficient.Some workers in Sweden are exposed to high levels of the non-threshold carcinogen Cr(VI). National strategies aligned with European strategies are needed to eliminate occupational cancer.
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33.
  • Madkour, Mohamed I., et al. (författare)
  • Ramadan diurnal intermittent fasting modulates SOD2, TFAM, Nrf2, and sirtuins (SIRT1, SIRT3) gene expressions in subjects with overweight and obesity
  • 2019
  • Ingår i: Diabetes Research and Clinical Practice. - Shannon, Ireland : Elsevier Ireland Ltd.. - 0168-8227 .- 1872-8227. ; 155
  • Tidskriftsartikel (refereegranskat)abstract
    • Aim: A growing body of evidence supports the impact of intermittent fasting on normalizing body metabolism and lowering oxidative stress and inflammation. Mounting evidence confirms that oxidative stress and chronic inflammation trigger the way for the development of metabolic diseases, such as diabetes. This research was conducted to evaluate the impact of Ramadan intermittent fasting (RIF) on the expression of cellular metabolism (SIRT1 and SIRT3) and antioxidant genes (TFAM, SOD2, and Nrf2).Methods: Fifty-six (34 males and 22 females) overweight and obese subjects and six healthy body weight controls were recruited and monitored before and after Ramadan.Results: Results showed that the relative gene expressions in obese subjects in comparison to counterpart expressions of controls for the antioxidant genes (TFAM, SOD2, and Nrf2) were significantly increased at the end of Ramadan, with percent increments of 90.5%, 54.1% and 411.5% for the three genes, respectively. However, the metabolism-controlling gene (SIRT3) showed a highly significant (P < 0.001) downregulation accompanied with a trend for reduction in SIRT1 gene at the end of Ramadan month, with percent decrements of 61.8% and 10.4%, respectively. Binary regression analysis revealed significant positive correlation (P < 0.05) between high energy intake (>2000 Kcal/day vs. <2000 Kcal/day) and expressions of SOD2 and TFAM (r = 0.84 and r = 0.9, respectively).Conclusion: Results suggest that RIF ameliorates the genetic expression of antioxidant and anti-inflammatory, and metabolic regulatory genes. Thus, RIF presumably may entail a protective impact against oxidative stress and its adverse metabolic-related derangements in non-diabetic obese patients.
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34.
  • Mao, Fang, et al. (författare)
  • Combinatorial Study of Gradient Ag-Al Thin Films : Microstructure, Phase Formation, Mechanical and Electrical Properties
  • 2016
  • Ingår i: ACS Applied Materials and Interfaces. - : American Chemical Society (ACS). - 1944-8244 .- 1944-8252. ; 8:44, s. 30635-30643
  • Tidskriftsartikel (refereegranskat)abstract
    • A combinatorial approach is applied to rapidly deposit and screen Ag-Al thin films-to evaluate the mechanical, tribological, and electrical properties as a function of chemical composition. Ag-Al thin films with large continuous composition gradients (6-60 atom % Al) were deposited by a custom-designed combinatorial magnetron sputtering system. X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDX), scanning and transmission electron microscopy (SEM and TEM), X-ray photoelectron spectroscopy (XPS), nanoindentation, and four-point electrical resistance screening were employed to characterize the chemical composition, structure, and physical properties of the films in a time-efficient way. For low Al contents (<13 atom %), a highly (111)-textured fcc phase was formed. At higher Al contents, a (002)-textured hcp solid solution phase was formed followed by a fcc phase in the most At-rich regions. No indication of a mu phase was observed. The Ag-Al films with fcc-Ag matrix is prone to adhesive material transfer leading to a high friction coefficient (>1) and adhesive wear, similar to the behavior of pure Ag. In contrast, the hexagonal solid solution phase (from ca. 15 atom %Al) exhibited dramatically reduced friction coefficients (about 15% of that of the fcc phase) and dramatically reduced adhesive wear when tested against the pure Ag counter surface. The increase in contact resistance of the Ag Al films is limited to only 50% higher than a pure Ag reference sample at the low friction and low wear region (19-27 atom %). This suggests that a hcp Ag Al alloy can have a potential use in sliding electrical contact applications and in the future will replace pure Ag in specific electromechanical applications.
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35.
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39.
  • Sami, Manal M., et al. (författare)
  • Expression of epidermal growth factor receptor and human epidermal growth factor receptor 2 in urothelial bladder carcinoma in an Egyptian cohort: Clinical implication and prognostic significance
  • 2023
  • Ingår i: UROLOGIA JOURNAL. - : SAGE PUBLICATIONS LTD. - 0391-5603 .- 1724-6075. ; 90:2, s. 246-260
  • Tidskriftsartikel (refereegranskat)abstract
    • Background: Bladder cancer (BC) has a particular importance in Egyptian patients due to aggressive behavior and absence of prognostic markers. Objective: To evaluate the expression of gene and protein expression of HER2 and epidermal growth factor (EGFR) in Egyptian patients with BC and ultimately to investigate their clinical implication and prognostic significance. Material and methods: The study was carried out on 46 patients with urothelial bladder BC. Tissue were obtained from transurethral resection (N = 22) and radical cystectomy (N = 24) specimens. The original hematoxylin and eosin slides were re-evaluated and the formalin fixed, paraffin-embedded (FFPE) tissues which had sufficient tumor tissue (>75%) and minimal or absent tumor necrosis were selected for immunohistochemistry (IHC) and RNA extraction. Furthermore, five control biopsies were obtained from patients with cystitis. Follow-up data were retrieved from the medical records which included the treatment regimen, disease recurrence and/or progression, and survival. Results: EGFR and HER2 protein were overexpressed in 35% and 46% of patients respectively. EGFR was correlated with the tumor size, grade and pathological stage, with a similar trend for HER2. The recurrence rate was higher in patients with expression of any of the markers. Gene expression was significantly higher (10.6-folds) for EGFR and (21-folds) for HER2 in patients with BC in comparison to control patients. Survival analysis showed lower median disease-free survival in association with HER2 protein overexpression. Conclusions: Our data highlighted the prognostic significance of EGFR and HER in BC and proposed their possible use as predictive markers and potential therapeutic targets.
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41.
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42.
  • Taher, Mamoun, et al. (författare)
  • The Influence of Chemical and Phase Composition on Mechanical, Tribological and Electrical Properties of Silver-Aluminum alloys
  • 2018
  • Ingår i: Tribology International. - : Elsevier BV. - 0301-679X .- 1879-2464. ; 119, s. 680-687
  • Tidskriftsartikel (refereegranskat)abstract
    • Ag1-xAlx alloys were investigated as potential sliding electrical contact materials. Seven Ag1-xAlx alloys, covering the different phase regions on the Ag-Al phase diagram, were prepared by arc melting. X-ray diffraction (XRD), scanning electron microscopy coupled with X-ray spectroscopy (SEM/EDX), X-ray photoelectron spectroscopy (XPS), nano- and microindentation, and four-point electrical contact resistance measurements were employed to characterize the composition, structure, and physicochemical properties of the alloys. The hardness of Ag1-xAlx alloys increases with Al content. The Ag1-xAlx alloys with hexagonal close-packed (hcp) structure exhibit better tribological properties than pure Ag and other phase compositions. The wear mechanisms change from adhesive, for the alloys with low Al content (<= 20 at. %) to oxidative and abrasive wear for the alloys with high Al content (>= 25 at. %). The Ag1-xAlx alloys with hcp structure exhibit the highest wear resistance. Depth-profile XPS data reveal that the oxide layer grows during the triboprocess and that its thickness increases with number of sliding cycles. Ag/Ag1-xAlx contact pairs exhibit higher contact resistance than the Ag/Ag pair and the contact resistance increases with Al content.
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43.
  • Taher, Mamoun, et al. (författare)
  • Tuning tribological, mechanical and electrical properties of Ag-X (X=Al, In, Sn) alloys
  • 2018
  • Ingår i: Tribology International. - : Elsevier BV. - 0301-679X .- 1879-2464. ; 125, s. 121-127
  • Tidskriftsartikel (refereegranskat)abstract
    • A new design concept for silver based alloys with a hexagonal structure as electrical contact materials with enhanced tribological properties has been investigated. The correlations between the phase composition and the tribological properties have been investigated in the Ag-Al, Ag-In and Ag-Sn systems. In each system, alloys with different chemical compositions were prepared by melting in evacuated ampoules. Characterisation techniques such as: optical microscopy, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning and transmission electron microscopies (SEM and TEM) have been used to evaluate the microhardneas, tribological properties and contact resistance of the samples. The phase compositions of the synthesized Ag-Al and Ag-Sn alloys were in agreement with the phase diagrams and the metastable hcp phase was observed in the Ag-In system. The friction coefficients and wear rates of all the hcp-Ag-X (X = Al, In, Sn) alloys were considerably lower than pure Ag or fcc-Ag alloys. This is attributed mainly to easily shearing basal planes in the hcp structure. The Ag-Sn alloys showed high contact resistances, making them less suitable for a sliding electrical contacts. In contrast, the Ag-In alloys showed much lower contact resistance, making them better alternatives for practical applications.
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44.
  • Yaiw, KC, et al. (författare)
  • Human Cytomegalovirus Reduces Endothelin-1 Expression in Both Endothelial and Vascular Smooth Muscle Cells
  • 2021
  • Ingår i: Microorganisms. - : MDPI AG. - 2076-2607. ; 9:6
  • Tidskriftsartikel (refereegranskat)abstract
    • Human cytomegalovirus (HCMV) is an opportunistic pathogen that has been implicated in the pathogenesis of atherosclerosis. Endothelin-1 (ET-1), a potent vasoconstrictive peptide, is overexpressed and strongly associated with many vasculopathies. The main objective of this study was to investigate whether HCMV could affect ET-1 production. As such, both endothelial and smooth muscle cells, two primary cell types involved in the pathogenesis of atherosclerosis, were infected with HCMV in vitro and ET-1 mRNA and proteins were assessed by quantitative PCR assay, immunofluorescence staining and ELISA. HCMV infection significantly decreased ET-1 mRNA and secreted bioactive ET-1 levels from both cell types and promoted accumulation of the ET-1 precursor protein in infected endothelial cells. This was associated with inhibition of expression of the endothelin converting enzyme-1 (ECE-1), which cleaves the ET-1 precursor protein to mature ET-1. Ganciclovir treatment did not prevent the virus suppressive effects on ET-1 expression. Consistent with this observation we identified that the IE2-p86 protein predominantly modulated ET-1 expression. Whether the pronounced effects of HCMV in reducing ET-1 expression in vitro may lead to consequences for regulation of the vascular tone in vivo remains to be proven.
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