Search

Abstract Background Anti-virulence therapy is a promising strategy to treat multi-drug resistant (MDR) pathogens. Pseudomonas aeruginosa is a potent opportunistic pathogen because of an array of virulence factors that are regulated by quorum sensing systems. Methods The virulence features of four multi-drug resistant P. aeruginosa strains were investigated upon exposure to the sub-lethal dose of gamma rays (1 kGy), and sub-inhibitory concentrations of bioactive metabolites recovered from local halophilic strains in comparison to control. Then, the gene expression of AHL-mediated quorum sensing systems (las/rhl) was quantitatively determined in treated and untreated groups by real-time PCR. Results The bioactive metabolites recovered from halophilic strains previously isolated from saline ecosystems were identified as Halomonas cupida (Halo-Rt1), H. elongate (Halo-Rt2), Vigibacillus natechei (Halo-Rt3), Sediminibacillus terrae (Halo-Rt4) and H. almeriensis (Halo-Rt5). Results revealed that both gamma irradiation and bioactive metabolites significantly reduced the virulence factors of the tested MDR strains. The bioactive metabolites showed a maximum efficiency for inhibiting biofilm formation and rhamnolipids production whereas the gamma irradiation succeeded in decreasing other virulence factors to lower levels in comparison to control. Quantitative-PCR results showed that AHL-mediated quorum sensing systems (las/rhl) in P. aeruginosa strains were downregulated either by halo-bacterial metabolites or gamma irradiation in all treatments except the upregulation of both lasI internal gene and rhlR intact gene in P. aeruginosa NCR-RT3 and both rhlI internal gene and rhlR intact gene in P. aeruginosa U3 by nearly two folds or more upon exposure to gamma irradiation. The most potent result was observed in the expression of lasI internal gene that was downregulated by more than ninety folds in P. aeruginosa NCR-RT2 after treatment with metabolites of S. terrae (Halo-Rt4). Analyzing metabolites recovered from H. cupida (Halo-Rt1) and H. elongate (Halo-Rt2) using LC–ESI–MS/MS revealed many chemical compounds that have quorum quenching properties including glabrol, 5,8-dimethoxyquinoline-2-carbaldehyde, linoleoyl ethanolamide, agelasine, penigequinolones derivatives, berberine, tetracosanoic acid, and liquidambaric lactone in the former halophile and phloretin, lycoctonine, fucoxanthin, and crassicauline A in the latter one. Conclusion QS inhibitors can significantly reduce the pathogenicity of MDR P. aeruginosa strains; and thus can be an effective and successful strategy for treating antibiotic resistant traits.

Abstract Background Coronaviruses are large, encapsulated RNA viruses that can infect both humans and animals and cause minor respiratory illnesses. In December 2019, numerous cases of pneumonia of unknown origin were reported in Wuhan, China. Coronavirus Disease 2019 (COVID-19), the cause of these cases, was discovered on January 6, 2020. The new coronavirus was declared an epidemic by the WHO on March, 2020. Several studies on COVID-19 have found that auditory complaints and hearing impairment can be detected using various tests. Objectives Pure tone audiometry (PTA) and transient evoked otoacoustic emissions (TEOAEs) were used to assess hearing in recovered SARS-CoV-2 patients. Also, to compare the presence of patient's auditory complaints with the test findings. Methods A case- control study was conducted, with each case and control group consisting of 58 people who were age and sex matched and ranged in age from 18 to 50 years. PTA, Extended PTA and, TEOAEs were used to evaluate hearing in both groups. Results PTA revealed a statistically significant difference in right ear thresholds at 250 Hz, 500 Hz, 4 kHz, and 8 kHz and left ear thresholds at 250 Hz, 4 kHz, 8 kHz, and 12.5 kHz between patients and controls. Additionally, a statistically significant difference in TEOAEs' overall reproducibility and amplitude between patients and controls was discovered. Affection for PTA and TEOAEs were related to the patient's complaints of hearing loss and tinnitus, respectively. Conclusions Whether a patient is symptomatic or not, COVID-19 may have a negative impact on their hearing.

Ashraf Omar,1 Ahmed Kaseb,2 Tamer Elbaz,1 Mohamed El-Kassas,3 Amr El Fouly,3 Abdel Fatah Hanno,4 Ahmed El Dorry,5 Ahmed Hosni,6 Amr Helmy,7 Amr S Saad,8 Ashwaq Alolayan,9 Basem Elsayed Eysa,10 Emad Hamada,11 Hamdy Azim,11 Hany Khattab,12 Hesham Elghazaly,8 Hesham Tawfik,13 Hisham Ayoub,14 Hussein Khaled,11 Ibtessam Saadeldin,11 Imam Waked,15 Eman MF Barakat,16 Mahmoud El Meteini,17 Mohamed Hamed Shaaban,6 Mohamed EzzElarab,10 Mohamed Fathy,17 Mohamed Shaker,5 Mohamed Sobhi,5 Mohamed Kamal Shaker,16 Mohamed ElGharib,5 Mohammed Abdullah,11 Mohesn Mokhtar,11 Mostafa Elshazli,18 Omar Mohamed Khaleil Heikal,14 Osama Hetta,5 Reda Mahmoud ElWakil,16 Sameh Abdel Wahab,5 Samir Shehata Eid,19 Yousri Rostom20 On behalf of the Egyptian Liver Cancer Committee Study Group1Department of Gastroenterology, Faculty of Medicine, Cairo University, Cairo, Egypt; 2Department of Gastrointestinal Medical Oncology, the University of Texas MD Anderson Cancer Center, Houston, TX, USA; 3Department of Endemic Medicine, Faculty of Medicine, Helwan University, Cairo, Egypt; 4Department of Gastroenterology, Faculty of Medicine, Alexandria University, Alexandria, Egypt; 5Department of Interventional Radiology, Faculty of Medicine, Ain Shams University, Cairo, Egypt; 6Department of Interventional Radiology, Faculty of Medicine, Cairo University, Cairo, Egypt; 7Department of Surgery, National Liver Institute Menoufia University, Menoufia, Egypt; 8Department of Oncology, Faculty of Medicine, Ain Shams University, Cairo, Egypt; 9Department of Oncology, National Guard Hospital, Riyadh, Saudi Arabia; 10Department of Gastroenterology, National Hepatology and Tropical Medicine Research Institute, Cairo, Egypt; 11Department of Oncology, Faculty of Medicine, Cairo University, Cairo, Egypt; 12Department of Pathology, Faculty of Medicine, Cairo University, Cairo, Egypt; 13Department of Oncology, Faculty of Medicine, Tanta University, Tanta Egypt; 14Department of Gastroenterology, Military Medical Academy, Cairo, Egypt; 15Department of Gastroenterology, Menoufia Liver Institute, Menoufia, Egypt; 16Department of Gastroenterology, Faculty of Medicine, Ain Shams University, Cairo, Egypt; 17Department of Surgery, Faculty of Medicine, Ain Shams University, Cairo, Egypt; 18Department of Surgery, Faculty of Medicine, Cairo University, Cairo, Egypt; 19Department of Oncology, Faculty of Medicine, Assiut University, Assiut, Egypt; 20Department of Oncology, Faculty of Medicine, Alexandria University, Alexandria, EgyptCorrespondence: Ashraf Omar, Department of Gastroenterology, Faculty of Medicine, Cairo University, Cairo, Egypt, Email abdelazizashraf@hotmail.comAbstract: Globally, hepatocellular carcinoma (HCC) is the fourth most common cause of death from cancer. The prevalence of this pathology, which has been on the rise in the last 30 years, has been predicted to continue increasing. HCC is the most common cause of cancer-related morbidity and mortality in Egypt and is also the most common cancer in males. Chronic liver diseases, including chronic hepatitis C, which is a primary health concern in Egypt, are considered major risk factors for HCC. However, HCC surveillance is recommended for patients with chronic hepatitis B virus (HBV) and liver cirrhosis; those above 40 with HBV but without cirrhosis; individuals with hepatitis D co-infection or a family history of HCC; and Nonalcoholic fatty liver disease (NAFLD) patients exhibiting significant fibrosis or cirrhosis. Several international guidelines aid physicians in the management of HCC. However, the availability and cost of diagnostic modalities and treatment options vary from one country to another. Therefore, the current guidelines aim to standardize the management of HCC in Egypt. The recommendations presented in this report represent the current management strategy at HCC treatment centers in Egypt. Recommendations were developed by an expert panel consisting of hepatologists, oncologists, gastroenterologists, surgeons, pathologists, and radiologists working under the umbrella of the Egyptian Society of Liver Cancer. The recommendations, which are based on the currently available local diagnostic aids and treatments in the country, include recommendations for future prospects.Keywords: hepatocellular carcinoma, clinical recommendations, Egyptian society of liver cancer, hepatitis c virus, Egypt, guidelines

Abstract Background The majority of obstructive sleep apnea cases involve the oropharynx. The hypercollapsibility of the upper airway walls (UAWs) was the cause of obstructive sleep apnea syndrome (OSAS), which most often manifested itself at the retropalatal and/or retrolingual level. Modular and adaptable barbed snore surgery (BSS) is a novel treatment for retropalatal OSA (based on the anatomy and findings of drug-induced sleep endoscopy (DISE). Objectives To compare between the outcomes of uvulopalatopharyngoplasty and the barbed reposition palatopharyngoplasty technique, and to establish if there is indeed a significant variance in post-operative results among both types of surgeries. Patients and methods This was a prospective randomized clinical trial conducted on Department of Otorhinolaryngology, Faculty of Medicine, Cairo University, and it was carried out on 50 patients (28 males and 22 females) suffering from OSAS. They were randomly distributed into two groups: group A and group B. Results There was a substantial distinction among the two groups regarding to post-operative data, comparison between values of all domains of Sleep Apnea Quality of Life Index (SAQLI) and bleeding and nasal regurgitation after surgery. There was no substantial distinction among the two groups in terms of age, sex, body mass index (BMI), smoking, hypertension, and diabetes mellitus. Conclusion Barbed reposition pharyngoplasty is superior to traditional uvulopalatopharyngoplasty in terms of results of Apnea Hypopnea Index (AHI), Epworth Sleepiness Scale (ESS), and in Sleep Apnea Quality of Life Index (SAQLI) in addition to producing less post-operative complications as well as being easy to learn.

Abstract Background The production of biopolymers from waste resources is a growing trend, especially in high-population countries like Egypt. Beta-glucan (β-glucan) belongs to natural polysaccharides that are derived from plant and microbial origins. In this study, following increasing demands for β-glucan owing to its bioactive properties, a statistical model to enhance microbial β-glucan production was evaluated for its usefulness to the food and pharmaceutical industries. In addition, a trial to convert β-glucan polymer to nanostructure form was done to increase its bioactivity. Results Ingredients of low-cost media based on agro-industrial wastes were described using Plackett–Burman and central composite design of response surface methodology for optimizing yeast β-glucan. Minerals and vitamin concentrations significantly influenced β-glucan yield for Kluyveromyces lactis and nitrogen and phosphate sources for Meyerozyma guilliermondii. The maximum predicted yields of β-glucan recovered from K. lactis and M. guilliermondii after optimizing the medium ingredients were 407 and 1188 mg/100 ml; respectively. For the first time, yeast β-glucan nanoparticles (βGN) were synthesized from the β-glucan polymer using N-dimethylformamide as a stabilizer and characterized using UV–vis spectroscopy, transmission electron microscope (TEM), dynamic light scattering (DLS) and Fourier transform infrared spectroscopy (FT-IR). The average size of βGN was about 300 nm as determined by DLS. The quantitative variation of functional groups between β-glucan polymer and βGN was evaluated by FT-IR for explaining the difference in their biological activity against Normal Homo sapiens-Hela contaminant and Hepatic cancer cell lines. Conclusions Enriching the low-cost media based on agro-industrial wastes with nutritional ingredients improves the yield of yeast β-glucan. The present study succeeds to form β-glucan nanoparticles by a simple method.

An investigation was consummated under shade condition at the nursery of Orman Botanical Garden, Giza, Egypt during 2020 and 2021 seasons to study the effect of pre-sowing treatments; i.e. seeds without any treatment (as control), soaking in tap water for 24 h at ambient temperature and soaking in hot water (70-80 °C) for 24 h, seed orientation treatments; horizontal with the micropyle oriented laterally and vertical with the micropyle positioned either upwards or downwards and their interactions on germination characters and seedling growth traits of African mahogany timber tree (Khaya senegalensis (Desr.) A. Juss) seeds. The results indicated that seeds soaked in hot water for 24 h failed to germinate in both seasons, while those soaked in tap water at room temperature for 24 h gave the highest percent of germination, the least No. days to either maximum or 50% germination as well as the best means of germination rate index, vigour index, seed viability and plumule length compared to control in the two seasons. Horizontal sowing method recorded the maximal germination percent, quickest germination, strongest vigour index and seed viability as well as the longest plumule length and followed by vertical one, in which the micropyle oriented upwards. So, the best results at all were obtained from combining soaking the seeds in tap water treatment and positioned them horizontally. A similar trend to that of germination characteristics was also occurred regarding seedling growth parameters. Accordingly, it can be proposed to soak Khaya senegalensis seeds in ordinary water pre-sowing for 24 h at ambient temperature and embedding them horizontally at 2 cm depth with the micropyle positioned laterally to obtain better germination and the best growth traits of the seedlings

The integration of renewable distributed generation (RDG) into distribution networks is promising and increasing nowadays. However, high penetration levels of distributed generation (DG) are often limited as they may have an adverse effect on the operation of distribution networks. One of the operation challenges is the interaction between DG and voltage-control equipment, e. g., an under-load tap changer (ULTC), which is basically designed to compensate for voltage changes caused by slow load variations. The integration of variable DGs leads to rapid voltage fluctuations, which can negatively affect the tap operation of ULTC. This paper investigates the impact of high penetration levels of RDG on the tap operation of ULTC in distribution networks through simulations. Various mitigation techniques that can alleviate this impact are also examined. Among these techniques, constant power-factor mode is regarded as the best trade-off between the simplicity and effectiveness of minimizing the number of tap operations. Simulations are performed on a Canadian benchmark rural distribution feeder using OpenDSS software.

Abstract This paper presents a sparse quaternion‐valued minimization (SQVM) based control technique of a two‐stage grid supportive photovoltaic (PV) power system with power conditioning capabilities. The grid side converter (GSC) is controlled by utilizing an SQVM control technique. The proposed algorithm enables the GSC to mitigate the load harmonics current and provides reactive power compensation at the point of common coupling (PCC). The proposed control is tuned to mitigate the DC offset error, harmonics current and to improve the frequency response of the proposed system. A DC link pre‐predictive is incorporated to improve the dynamic response by reducing the burden on the outer Proportional‐Integral (PI) voltage controller loop. Further, it is used to extract the fundamental component of load currents for generating the reference currents. An adjustable DC link voltage loop is incorporated in the proposed control technique to adapt the PCC voltage variation, which helps in minimizing the losses of the PV system. For real‐time execution of the adjustable DC link voltage concept, the DC link voltage is adapted with a variation in the PCC voltage. The operation and control of the system topology are validated experimentally under various scenarios.

This article introduces a new time-domain fault location algorithm for two-terminal parallel transmission lines connected to large scale wind farms. The proposed algorithm employs only a half-cycle data window of synchronized current samples at both line terminals to avoid inaccurate estimation of current phasors due to the generated sub- and inter-harmonics currents by the wind farms. The proposed algorithm does not need any transformation method to decouple the double-circuit transmission line. Moreover, it takes into consideration the effect of the line asymmetry and the potential couplings between the six phases. The fault location equation is deduced by equalizing the differential components of the calculated instantaneous voltages at the fault point, and then the fault distance is estimated directly without any iterative algorithm. The two-terminal parallel transmission line is emulated by PSCAD/EMTDC platform utilizing the frequency-dependent phase model, and the required calculations for fault location are conducted by MATLAB software. The proposed algorithm is tested for several fault resistances and fault locations, and all fault types, including cross-circuit faults. In addition, the effect of measurement, synchronization, and line parameters errors on the fault location accuracy is investigated. The obtained results confirm acceptable accuracy of the proposed fault location algorithm.