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Sökning: WFRF:(El Sayed Ashraf S.A.)

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1.
  • Sheena, B. S., et al. (författare)
  • Global, regional, and national burden of hepatitis B, 1990-2019: a systematic analysis for the Global Burden of Disease Study 2019
  • 2022
  • Ingår i: Lancet Gastroenterology & Hepatology. - : Elsevier BV. - 2468-1253. ; 7:9, s. 796-829
  • Tidskriftsartikel (refereegranskat)abstract
    • Background Combating viral hepatitis is part of the UN Sustainable Development Goals (SDGs), and WHO has put forth hepatitis B elimination targets in its Global Health Sector Strategy on Viral Hepatitis (WHO-GHSS) and Interim Guidance for Country Validation of Viral Hepatitis Elimination (WHO Interim Guidance). We estimated the global, regional, and national prevalence of hepatitis B virus (HBV), as well as mortality and disability-adjusted life-years (DALYs) due to HBV, as part of the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019. This included estimates for 194 WHO member states, for which we compared our estimates to WHO elimination targets. Methods The primary data sources were population-based serosurveys, claims and hospital discharges, cancer registries, vital registration systems, and published case series. We estimated chronic HBV infection and the burden of HBV-related diseases, defined as an aggregate of cirrhosis due to hepatitis B, liver cancer due to hepatitis B, and acute hepatitis B. We used DisMod-MR 2.1, a Bayesian mixed-effects meta-regression tool, to estimate the prevalence of chronic HBV infection, cirrhosis, and aetiological proportions of cirrhosis. We used mortality-to-incidence ratios modelled with spatiotemporal Gaussian process regression to estimate the incidence of liver cancer. We used the Cause of Death Ensemble modelling (CODEm) model, a tool that selects models and covariates on the basis of out-ofsample performance, to estimate mortality due to cirrhosis, liver cancer, and acute hepatitis B. Findings In 2019, the estimated global, all-age prevalence of chronic HBV infection was 4 center dot 1% (95% uncertainty interval [UI] 3 center dot 7 to 4 center dot 5), corresponding to 316 million (284 to 351) infected people. There was a 31 center dot 3% (29 center dot 0 to 33 center dot 9) decline in all-age prevalence between 1990 and 2019, with a more marked decline of 76 center dot 8% (76 center dot 2 to 77 center dot 5) in prevalence in children younger than 5 years. HBV-related diseases resulted in 555 000 global deaths (487 000 to 630 000) in 2019. The number of HBV-related deaths increased between 1990 and 2019 (by 5 center dot 9% [-5 center dot 6 to 19 center dot 2]) and between 2015 and 2019 (by 2 center dot 9% [-5 center dot 9 to 11 center dot 3]). By contrast, all-age and age-standardised death rates due to HBV-related diseases decreased during these periods. We compared estimates for 2019 in 194 WHO locations to WHO-GHSS 2020 targets, and found that four countries achieved a 10% reduction in deaths, 15 countries achieved a 30% reduction in new cases, and 147 countries achieved a 1% prevalence in children younger than 5 years. As of 2019, 68 of 194 countries had already achieved the 2030 target proposed in WHO Interim Guidance of an all-age HBV-related death rate of four per 100 000. Interpretation The prevalence of chronic HBV infection declined over time, particularly in children younger than 5 years, since the introduction of hepatitis B vaccination. HBV-related death rates also decreased, but HBV-related death counts increased as a result of population growth, ageing, and cohort effects. By 2019, many countries had met the interim seroprevalence target for children younger than 5 years, but few countries had met the WHO-GHSS interim targets for deaths and new cases. Progress according to all indicators must be accelerated to meet 2030 targets, and there are marked disparities in burden and progress across the world. HBV interventions, such as vaccination, testing, and treatment, must be strategically supported and scaled up to achieve elimination.
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2.
  • El-Sayed, Ashraf S. A., et al. (författare)
  • Exploiting the Biosynthetic Potency of Taxol from Fungal Endophytes of Conifers Plants : Genome Mining and Metabolic Manipulation
  • 2020
  • Ingår i: Molecules. - : MDPI. - 1431-5157 .- 1420-3049. ; 25:13
  • Forskningsöversikt (refereegranskat)abstract
    • Endophytic fungi have been considered as a repertoire for bioactive secondary metabolites with potential application in medicine, agriculture and food industry. The biosynthetic pathways by fungal endophytes raise the argument of acquisition of these machineries of such complex metabolites from the plant host. Diterpenoids "Taxol" is the most effective anticancer drug with highest annual sale, since its discovery in 1970 from the Pacific yew tree,Taxus brevifolia. However, the lower yield of Taxol from this natural source (bark ofT. brevifolia), availability and vulnerability of this plant to unpredicted fluctuation with the ecological and environmental conditions are the challenges. Endophytic fungi fromTaxusspp. opened a new avenue for industrial Taxol production due to their fast growth, cost effectiveness, independence on climatic changes, feasibility of genetic manipulation. However, the anticipation of endophytic fungi for industrial Taxol production has been challenged by the loss of its productivity, due to the metabolic reprograming of cells, downregulating the expression of its encoding genes with subculturing and storage. Thus, the objectives of this review were to (1) Nominate the endophytic fungal isolates with the Taxol producing potency from Taxaceaeand Podocarpaceae; (2) Emphasize the different approaches such as molecular manipulation, cultural optimization, co-cultivation for enhancing the Taxol productivities; (3) Accentuate the genome mining of the rate-limiting enzymes for rapid screening the Taxol biosynthetic machinery; (4) Triggering the silenced rate-limiting genes and transcriptional factors to activates the biosynthetic gene cluster of Taxol.
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3.
  • El-Sayed, Ashraf S.A., et al. (författare)
  • Production, bioprocess optimization and anticancer activity of Camptothecin from Aspergillus terreus and Aspergillus flavus, endophytes of Ficus elastica
  • 2021
  • Ingår i: Process Biochemistry. - : Elsevier. - 1359-5113 .- 1873-3298. ; 107, s. 59-73
  • Tidskriftsartikel (refereegranskat)abstract
    • Attenuating the biosynthetic potency of camptothecin producing fungi with the multiple subculturing and storage is the major challenge that limits the scaling-up of this approach. Thus, screening for novel fungal isolates with reliable metabolic stability and sustainability for camptothecin production is the objective of this work. Among the recovered isolates, Aspergillus terreus (320 μg/l) and A. flavus (290 μg/l) "endophytes of Ficus elastica" were the most potent camptothecin producing isolates. The chemical identity of extracted camptothecin was resolved from the HPLC, NMR, FTIR and LC–MS analyses, with a strong antiproliferative activity against MCF7 (0.18 μM), LS174 T, HCT29 (0.29−0.43 μM), HEPG-2 (0.73 μM) cell lines. The yield of camptothecin was decreased by about > 60 % by the 7th subculturing for both fungal isolates. Upon using Blackett-Burman design to optimize their nutritional requirements by the fungal isolates, their yield of camptothecin were increased by approximately 2 folds, revealing the essentiality of some carbon, nitrogen and growth elicitors for biosynthesis of camptothecin. Interestingly, the biosynthetic machinery of camptothecin by the 7th generation fungal isolates were completely restored upon addition of 1% surface sterilized leaves of F. elastica, while all the other experimented plant extracts did not display any effect on camptothecin production. So, chemicals signals derived from the plant /or its entire microbiome "microbial communication" triggering the expression of camptothecin biosynthetic gene cluster of these fungi, could be the most conceivable hypothesis explaining the attenuation and restoration processes of camptothecin biosynthesis by target the fungal isolates. This is the first report describing the feasibility of A. terreus and A. flavus "endophytes of F. elastica" for camptothecin production with reliable metabolic and sustainable biosynthetic potency upon addition of the plant host's entire microbiome, that could be a preliminary platform for scaling-up of camptothecin production.
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4.
  • El-Sayed, Ashraf S. A., et al. (författare)
  • Purification and biochemical characterization of taxadiene synthase from bacillus koreensis and stenotrophomonas maltophilia
  • 2021
  • Ingår i: Scientia pharmaceutica. - : MDPI. - 0036-8709 .- 2218-0532. ; 89:4
  • Tidskriftsartikel (refereegranskat)abstract
    • Taxadiene synthase (TDS) is the rate-limiting enzyme of Taxol biosynthesis that cyclizes the geranylgeranyl pyrophosphate into taxadiene. Attenuating Taxol productivity by fungi is the main challenge impeding its industrial application; it is possible that silencing the expression of TDS is the most noticeable genomic feature associated with Taxol-biosynthetic abolishing in fungi. As such, the characterization of TDS with unique biochemical properties and autonomous expression that is independent of transcriptional factors from the host is the main challenge. Thus, the objective of this study was to kinetically characterize TDS from endophytic bacteria isolated from different plants harboring Taxol-producing endophytic fungi. Among the recovered 23 isolates, Bacillus koreensis and Stenotrophomonas maltophilia achieved the highest TDS activity. Upon using the Plackett–Burman design, the TDS productivity achieved by B. koreensis (18.1 µmol/mg/min) and S. maltophilia (14.6 µmol/mg/min) increased by ~2.2-fold over the control. The enzyme was purified by gel-filtration and ion-exchange chromatography with ~15 overall folds and with molecular subunit structure 65 and 80 kDa from B. koreensis and S. maltophilia, respectively. The chemical identity of taxadiene was authenticated from the GC-MS analyses, which provided the same mass fragmentation pattern of authentic taxadiene. The tds gene was screened by PCR with nested primers of the conservative active site domains, and the amplicons were sequenced, displaying a higher similarity with tds from T. baccata and T. brevifolia. The highest TDS activity by both bacterial isolates was recorded at 37–40 °C. The Apo-TDSs retained ~50% of its initial holoenzyme activities, ensuring their metalloproteinic identity. The activity of purified TDS was completely restored upon the addition of Mg2+, confirming the identity of Mg2+ as a cofactor. The TDS activity was dramatically reduced upon the addition of DTNB and MBTH, ensuring the implementation of cysteine-reactive thiols and ammonia groups on their active site domains. This is the first report exploring the autonomous robust expression TDS from B. koreensis and S. maltophilia with a higher affinity to cyclize GGPP into taxadiene, which could be a novel platform for taxadiene production as intermediary metabolites of Taxol biosynthesis.
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5.
  • Cousin, E., et al. (författare)
  • Diabetes mortality and trends before 25 years of age: an analysis of the Global Burden of Disease Study 2019
  • 2022
  • Ingår i: Lancet Diabetes & Endocrinology. - : Elsevier BV. - 2213-8587. ; 10:3, s. 177-192
  • Tidskriftsartikel (refereegranskat)abstract
    • Background Diabetes, particularly type 1 diabetes, at younger ages can be a largely preventable cause of death with the correct health care and services. We aimed to evaluate diabetes mortality and trends at ages younger than 25 years globally using data from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019. Methods We used estimates of GBD 2019 to calculate international diabetes mortality at ages younger than 25 years in 1990 and 2019. Data sources for causes of death were obtained from vital registration systems, verbal autopsies, and other surveillance systems for 1990-2019. We estimated death rates for each location using the GBD Cause of Death Ensemble model. We analysed the association of age-standardised death rates per 100 000 population with the Socio-demographic Index (SDI) and a measure of universal health coverage (UHC) and described the variability within SDI quintiles. We present estimates with their 95% uncertainty intervals. Findings In 2019, 16 300 (95% uncertainty interval 14 200 to 18 900) global deaths due to diabetes (type 1 and 2 combined) occurred in people younger than 25 years and 73.7% (68.3 to 77.4) were classified as due to type 1 diabetes. The age-standardised death rate was 0.50 (0.44 to 0.58) per 100 000 population, and 15 900 (97.5%) of these deaths occurred in low to high-middle SDI countries. The rate was 0.13 (0.12 to 0.14) per 100 000 population in the high SDI quintile, 0.60 (0.51 to 0.70) per 100 000 population in the low-middle SDI quintile, and 0.71 (0.60 to 0.86) per 100 000 population in the low SDI quintile. Within SDI quintiles, we observed large variability in rates across countries, in part explained by the extent of UHC (r(2)=0.62). From 1990 to 2019, age-standardised death rates decreased globally by 17.0% (-28.4 to -2.9) for all diabetes, and by 21.0% (-33.0 to -5.9) when considering only type 1 diabetes. However, the low SDI quintile had the lowest decline for both all diabetes (-13.6% [-28.4 to 3.4]) and for type 1 diabetes (-13.6% [-29.3 to 8.9]). Interpretation Decreasing diabetes mortality at ages younger than 25 years remains an important challenge, especially in low and low-middle SDI countries. Inadequate diagnosis and treatment of diabetes is likely to be major contributor to these early deaths, highlighting the urgent need to provide better access to insulin and basic diabetes education and care. This mortality metric, derived from readily available and frequently updated GBD data, can help to monitor preventable diabetes-related deaths over time globally, aligned with the UN's Sustainable Development Targets, and serve as an indicator of the adequacy of basic diabetes care for type 1 and type 2 diabetes across nations. Copyright (C) 2022 The Author(s). Published by Elsevier Ltd.
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6.
  • El-Sayed, Ashraf S. A., et al. (författare)
  • Aspergillus nidulans thermostable arginine deiminase-Dextran conjugates with enhanced molecular stability, proteolytic resistance, pharmacokinetic properties and anticancer activity
  • 2019
  • Ingår i: Enzyme and microbial technology. - : Elsevier. - 0141-0229 .- 1879-0909. ; 131
  • Tidskriftsartikel (refereegranskat)abstract
    • The potential anticancer activity of arginine deiminase (ADI) via deimination of L-arginine into citrulline has been extensively verified against various arginine-auxotrophic tumors, however, the higher antigenicity, structural instability and in vivo proteolysis are the major challenges that limit this enzyme from further clinical implementation. Since, this clinically applied enzyme was derived from Mycobacterium spp, thus, searching for ADI from eukaryotic microbes "especially thermophilic fungi" could have a novel biochemical conformational and catalytic properties. Aspergillus nidulans ADI was purified with 5.3 folds, with molecular subunit structure 48 kDa and entire molecular mass 120 kDa, ensuring its homotrimeric identity. The peptide fingerprinting analysis revealing the domain Glu(95)-Gly(96)-Gly(97) as the conserved active site of A. nidulans ADI, with higher proximity to Mycobacterium ADI Glade IV. In an endeavor to fortify the structural stability and anticancer activity of A. nidulans ADI, the enzyme was chemically modified with dextran. The optimal activity of Dextran-ADI conjugates was determined at 0.08:20 M ratio of ADI: Dextran, with an overall increase to ADI molecular subunit mass to (similar to)100 kDa. ADI was conjugated with dextran via the a-amino groups interaction of surface lysine residues of ADI. The resistance of Dextran-ADI conjugate to proteolysis had been increased by 2.5 folds to proteinase K and trypsin, suggesting the shielding of > 50% of ADI surface proteolytic recognition sites. The native and Dextran-ADI conjugates have the same optimum reaction temperature (37 degrees C), reaction pH and pH stability (7.0-8.0) with dependency on K+ ions as a cofactor. Dextran-ADI conjugates exhibited a higher thermal stability by (similar to) 2 folds for all the tested temperatures, ensuring the acquired structural and catalytic stability upon dextran conjugation. Dextran conjugation slightly protect the reactive amino and thiols groups of surface amino acids of ADI from amino acids suicide inhibitors. The affinity of ADI was increased by 5.3 folds to free L-arginine with a dramatic reduction in citrullination of peptidylarginine residues upon dextran conjugation. The anticancer activity of ADI to breast (MCF-7), liver (HepG-2) and colon (HCTB, HT29, DLD1 and LS174 T) cancer cell lines was increased by 1.7 folds with dextran conjugation in vitro. Pharmacokinetically, the half-life time of ADI was increased by 1.7 folds upon dextran conjugation, in vivo. From the biochemical and hematological parameters, ADIs had no signs of toxicity to the experimental animals. In addition to the dramatic reduction of L-arginine in serum, citrulline level was increased by 2.5 folds upon dextran conjugation of ADI. This is first report exploring thermostable ADI from thermophilic A. nidulans with robust structural stability, catalytic efficiency and proteolytic resistance.
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7.
  • El-Sayed, Ashraf S. A., et al. (författare)
  • Conjugation of Aspergillus flavipes Taxol with Porphyrin Increases the Anticancer Activity of Taxol and Ameliorates Its Cytotoxic Effects
  • 2020
  • Ingår i: Molecules. - : MDPI. - 1431-5157 .- 1420-3049. ; 25:2
  • Tidskriftsartikel (refereegranskat)abstract
    • Taxol is one of the potential anticancer drugs; however, the yield of Taxol and its cytotoxicity are common challenges. Thus, manipulating the Taxol biosynthetic pathway from endophytic fungi, in addition to chemical modification with biocompatible polymers, is the challenge. Four fungal isolates, namely, Aspergillus flavipes, A. terreus, A. flavus, and A. parasiticus, were selected from our previous study as potential Taxol producers, and their potency for Taxol production was evaluated in response to fluconazole and silver nitrate. A higher Taxol yield was reported in the cultures of A. flavipes (185 mu g/L) and A. terreus (66 mu g/L). With addition of fluconazole, the yield of Taxol was increased 1.8 and 1.2-fold for A. flavipes and A. terreus, respectively, confirming the inhibition of sterol biosynthesis and redirecting the geranyl phosphate pool to terpenoids synthesis. A significant inhibition of ergosterol biosynthesis by A. flavipes with addition of fluconazole was observed, correlating with the increase on Taxol yield. To increase the Taxol solubility and to reduce its cytotoxicity, Taxol was modified via chemical conjugation with porphyrin, and the degree of conjugation was checked from the Thin layer chromatography and UV spectral analysis. The antiproliferative activity of native and modified Taxol conjugates was evaluated; upon porphyrin conjugation, the activity of Taxol towards HepG2 was increased 1.5-fold, while its cytotoxicity to VERO cells was reduced 3-fold.
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