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Nanoparticle (NP) pollution is a worldwide problem. Copper oxide nanoparticles (CuO NPs) are one of the most used NPs in a variety of applications, which results in their increased release into the marine environment. In the present work, the marine mussel Lithophaga lithophaga was used as a model organism to evaluate the toxic effects of CuO NPs following 28 days of exposure to sub-lethal concentrations (5 and 20 μg/L). The time points were 1 day of exposure to assess the cell viability, phagocytosis in mussel haemocytes and genotoxicity (DNA damage in gills), 1, 14 and 28 days of exposure to evaluate copper concentrations in water and gills, as well as metallothionein concentration in gills, while gill histology and SEM examination were done after 28 days of exposure. The results indicated that the accumulation of CuO NPs in gills increased with concentration and time. Mussel exposure to CuO NPs increased neutral red uptake. However, the phagocytic abilities decreased in haemocytes with increased concentration. CuO NPs caused DNA damage in the gills even at low concentrations (5 µg/L). CuO NPs caused histopathological alterations in gills, such as brown cell accumulation, necrosis, dwarfism of filaments and ciliary erosion. In conclusion, exposure of the mussel L. lithophaga to CuO NPs led to concentration- and time-dependent responses for all the examined biomarkers. Thus, L. lithophaga may be used as a bioindicator organism in the assessment of CuO NP toxicity.

After the global pandemic of the new coronavirus, its rapid spread and many victims, it is necessary to find an effective vaccine or drugs to overcome it. Most specialists consider that repositioning some medications is the best, fastest and most reliable option for treating patients with the new coronavirus without delay. One of these drugs was an old antimalarial drug, hydroxychloroquine. The current review aimed to explore its potential mechanism, as well as its pharmacokinetics and toxicity, in an attempt to suggest a treatment protocol for its use in treating the COVID-19 virus effectively and safely. This study reviewed the published references on the popular search engines as well as the reference books regarding the pharmacological effects of HCQ. The results of this study suggested the following practical guidelines to optimize HCQ efficacy and safety in the management of COVID-19. HQC should be used as early as possible, i.e., once the viral infection is confirmed or suspected. A loading dose is recommended to be given in 3-4 divided doses to minimize cardiac toxicity. Maintenance daily dose (divided into two doses), should be continued until complete remission. Precautions, drug-interaction, contraindications, variable metabolic pathways in the particular population should be considered. This study suggests more clinical trials regarding the use of HCQ in the management of early identified COVID-19 patients under close medical observation to minimize HCQ cardiac toxicity.

El-Ghwas DE, Al-Nasser AS, Al-Sheikhy AA. 2021. Short Communication: Bacillus endolithicus and Bacillus paramycoides: New Isolates from housefly Musca domestica in Saudi Arabia. Biodiversitas 22: 4209-4214. Housefly Musca domestica Linnaeus is a common insect widely distributed all over the world. It is one of the domestic insects found associated with humans and animals. The present study investigated the bacterial diversity associated with Musca domestica samples collected from different places such as food courts and trash cans near fast-food restaurants in Makkah Province from October 2019 to December 2019. Eighteen pure isolates of bacterial strains were isolated and identified by Gram staining. Most of the bacterial isolates were Gram-positive except for two species, which were Gram-negative. The VITEK system was used to identify randomly isolate no. 5, 7, 17, 18, and 29. The results revealed that they belonged to the genus Bacillus sp., Staphylococcus sp., Pseudomonas sp., and Micrococcus sp. respectively. Due to the most isolated strains were Bacillus sp., so 16S RNA was used to genetically identify novel isolated strains 5 and 7. Isolate no. 5 showed the highest similarity (99 %) with Bacillus endolithicus, and isolate no. 7 showed the highest similarity (99 %) with Bacillus paramycoides. This is the first record of Bacillus endolithicus and Bacillus paramycoides to be isolated from the house fly Musca domestica L.

Objectives: This study aimed to assess parental knowledge, attitudes and practices regarding antibiotic use for children with upper respiratory tract infections (URTIs). Methods: A multi-centre cross-sectional study was conducted from September 2018 to April 2019 at 15 randomly selected primary health centres in Muscat, Oman. A total of 384 parents with children under 12 years old were recruited. A validated questionnaire was utilised to determine knowledge, attitudes and practices regarding antibiotic use for children with URTIs. Results: All 384 parents participated in the study (response rate: 100%). Almost half of the participants (n = 173; 45.1%) agreed that antibiotics were the first and best treatment for URTIs in children, with 184 parents (47.9%) reporting that influenza symptoms in children improved more rapidly after the administration of antibiotics and 203 (52.9%) believing that antibiotics prevented complications. The majority (n = 219; 57.0%) of parents never gave their children antibiotics without a prescription, and 291 (75.8%) never used leftover antibiotics. Most participants (n = 233; 60.7%) stated that it was the doctor’s decision to prescribe antibiotics, 192 (50.0%) had never asked a physician to prescribe antibiotics for their child and 256 (66.7%) had never changed doctors because they did not prescribe antibiotics. Conclusion: This study found that parents had confidence in their healthcare providers; however, it also showed the extent of their lack of knowledge regarding the use of antibiotics for children with URTIs. There is a need for both public- and healthcare professional-oriented educational initiatives to promote rational antibiotic usage in Oman. Keywords: Practice, Attitudes and Health Knowledge; Antibiotics; Drug Utilization; Parents; Children; Upper Respiratory Tract Infections; Oman.

Chemical modifications of chitosan were of interest to scientific researchers for its wide applications. Chitosan has been widely used for synthesis of unique compounds with potential biological activity and also effective for wastewater treatment. In the current study fabrication of new chitosan-based Schiff base hydrogels were fabricated through modification of chitosan with isonicotinic aldehyde to give hydrogel I or with epichlorohydrin or sodium tripolyphosphate via ionotropic gelation processes under the same reaction conditions to give hydrogels Ie, and nanohydrogels II, IIe respectively. FTIR, XRD, TGA, DSC, SEM, and TEM tools were used for characterization of the fabricated hydrogels I, Ie, II, and IIe hydrogels. The swelling behavior of the fabricated hydrogels in different solvents were determined. Evaluation of the hydrogels for leaching metal ions and biological activity towards different Gram-positive and Gram-negative of microorganisms were studied. The results showed that the highest efficiency for adsorption of cobalt and mercuric ions was revealed for hydrogels Ie, IIe (91.3%, 95.9%) and (92.5%, 95.9%) respectively. However, hydrogel IIe showed remarkable MIC and MBC towards Gram-positive (B. subtilis) (19.5, 38) μg/ml compared to the standard antibiotic Ciprofloxacin (19, 38) μg/ml respectively.

Hematopoietic stem cells (HSCs) surface during embryogenesis leading to the genesis of the hematopoietic system, which is vital for immune function, homeostasis balance, and inflammatory responses in the human body. Hematopoiesis is the process of blood cell formation, which initiates from hematopoietic stem/progenitor cells (HSPCs) and is responsible for the generation of all adult blood cells. With their self-renewing and pluripotent properties, human pluripotent stem cells (hPSCs) provide an unprecedented opportunity to createin vitromodels of differentiation that will revolutionize our understanding of human development, especially of the human blood system. The utilization of hPSCs provides newfound approaches for studying the origins of human blood cell diseases and generating progenitor populations for cell-based treatments. Current shortages in our knowledge of adult HSCs and the molecular mechanisms that control hematopoietic development in physiological and pathological conditions can be resolved with better understanding of the regulatory networks involved in hematopoiesis, their impact on gene expression, and further enhance our ability to develop novel strategies of clinical importance. In this review, we delve into the recent advances in the understanding of the various cellular and molecular pathways that lead to blood development from hPSCs and examine the current knowledge of human hematopoietic development. We also review howin vitrodifferentiation of hPSCs can undergo hematopoietic transition and specification, including major subtypes, and consider techniques and protocols that facilitate the generation of hematopoietic stem cells.

Poly(vinyl chloride) (PVC) is modified by N-phenyl itaconimide derivatives (N-(RPh)IM) as modifying agents or graft comonomers. The resulting modified polymers or graft copolymers were characterized using FTIR and UV/Vis spectrophotometry. The thermal properties of the modified polymers were investigated using thermogravimetry (TGA), which revealed that the synthesized polymers exhibited high thermal stability, as shown from the value of their initial decomposition temperatures and the percentage of weight loss at high temperatures. The polymer modified by 4-bromo itaconimide exhibited the most thermal stability. A mechanism for the modification reaction and the graft copolymerization of PVC was suggested.

Human pluripotent stem cells (hPSCs) offer the potential to serve as a versatile and scalable source of T cells for immunotherapies, which could be coupled with genetic engineering technologies to meet specific clinical needs. To improve T cell production from hPSCs, it is essential to identify cell subsets that are highly enriched in T cell progenitors and those stages of development at which NOTCH activation induces the most potent T cells. In this study, we evaluated the efficacy of T cell production from cell populations isolated at different stages of hematopoietic differentiation, including mesoderm, hemogenic endothelium (HE), and multipotent hematopoietic progenitors. We demonstrate that KDRhiCD31− hematovascular mesodermal progenitors (HVMPs) with definitive hematopoietic potential produce the highest numbers of T cells when cultured on OP9-DLL4 as compared with downstream progenitors, including HE and multipotent hematopoietic progenitors. In addition, we found that T cells generated from HVMPs have the capacity to expand for 6–7 wk in vitro, in comparison with T cells generated from HE and hematopoietic progenitors, which could only be expanded for 4–5 wk. Demonstrating the critical need of NOTCH activation at the HVMP stage of hematopoietic development to establish robust T cell production from hPSCs may aid in establishing protocols for the efficient off-the-shelf production and expansion of T cells for treating hematologic malignancies.

Three types of N[4-(N-substituted amino carbonyl)phenyl] maleimide (RPhMI:N-substituent (R) = phenyl, cyclohexyl, p-chlorophenyl) were grafted onto poly(vinyl chloride) (PVC) films by using gamma irradiation. The effects of different parameters on the graft yield were investigated. These parameters included radiation dose and monomer concentration. Thermal properties of the grafted polymer were investigated by the determination of dehydrochlorination rate, thermal gravimetric behavior, and UV stability.

Objective: To determine the cellular immune response in Bell’s palsy (BP) and its prognostic value in relation to clinical and electrophysiological findings.Methods: Twenty patients with BP were subjected to: Facial nerve paralysis assessment according to House–Brackmann (H&B) grading system, bilateral facial nerve conduction study with electroneurography (ENoG) quotient calculation, blink reflex, and needle electromyography (EMG) for the affected side; one week from the onset. Before the start of medical treatment, peripheral blood mononuclear cell subsets were analyzed to reveal the percentage of total T cells (CD3+), T helper/inducer cells (CD4+), T cytotoxic (CD8+) and B cells (CD19+). Patients were followed up by H&B, ENoG and needle EMG up to 3 months from the onset (end point). Fifteen age and sex matched healthy control subjects for the electrophysiological study and laboratory tests were included.Results: The percentages of CD3+, CD4+ & CD8+ were significantly depressed in BP patients than in control. CD19+ percentage did not show significant difference between them. On follow up, H&B revealed significant improvement. Neither electrophysiological parameters nor ENoGshowed significant difference between initial and follow up assessments. Initial CD4+ percentage correlated negatively with disease duration. While Initial CD8+ percentage correlated positively with follow up compound muscle action potential (CMAP) amplitude of orbicularis oris muscleand ENoG of orbicularis oculi and nasalis muscles. Initial CD19+ percentage correlated negatively with follow up H&B and R1 & R2 responses of follow up blink reflex. Initial CD3+ percentage did not correlate with any of the follow up measures.Conclusion: Decreased percentage of peripheral blood CD3+, CD4+ & CD8+ in BP patients emphasizes the role of cell mediated autoimmune pathogenesis in the acute stage of the disease. These cells have a prognostic significance for prediction of the disease duration and outcome. Analysis of T lymphocytes subsets may provide an additional parameter to differentiate patients with favorable from those with poor prognosis.