Bioactivity of Metabolites from Actinomycetes Isolates from Red Sea, Egypt

Osman, Mohamed E.,El-nasr, Amany A. Abo,Hussein, Hagar M,Hamed, Moaz M The Korean Society for Microbiology and Biotechnol 2022 한국미생물·생명공학회지 Vol.50 No.2

Actinomycetes isolated from marine habitats represent a promising source of bioactive substances. Here, we report on the isolation, identification, productivity enhancement and application of the bioactive compounds of Streptomyces qinglanensis H4. Eighteen marine actinomycetes were isolated and tested for resistance to seven bacterial diseases. Using 16S rRNA sequencing analysis (GenBank accession number MW563772), the most powerful isolate was identified as S. qinglanensis. Although the strain produced active compound(s) against a number of Gram-negative and Gram-positive bacteria, it failed to inhibit pathogenic fungi. The obtained inhibition zones were 22.0 ± 1.5, 20.0 ± 1, 16.0 ± 1, 12.0 ± 1, 22.0 ± 1 and 24.0 ± 1 mm against Bacillus subtilis ATCC 6633, Escherichia coli ATCC 19404, Enterococcus faecalis ATCC 29212, Pseudomonas aeruginosa ATCC 9027, Candida albicans ATCC 10231 and Staphylococcus aureus ATCC6538, respectively. To maximize bioactive compound synthesis, the Plackett-Burman design was used. The productivity increased up to 0.93-fold, when S. qinglanensis was grown in optimized medium composed of: (g/l) starch 30; KNO₃ 0.5; K₂HPO₄ 0.25; MgSO₄ 0.25; FeSO₄·7H₂O, 0.01; sea water concentration (%) 100; pH 8.0, and an incubation period of 9 days. Moreover, the anticancer activity of S. qinglanensis was tested against two different cell lines: HepG2 and CACO. The inhibition activities were 42.96 and 57.14%, respectively. Our findings suggest that the marine S. qinglanensis strain, which grows well on tailored medium, might be a source of bioactive substances for healthcare companies.

Biology of the mason bee Osmia latreillei (Hymenoptera: Megachilidae) under artificial nesting conditions in Egypt

Mohamed A. Shebl,Hanan A. Hassan,Soliman M. Kamel,Mohamed A.M. Osman,Michael S. Engel 한국응용곤충학회 2018 Journal of Asia-Pacific Entomology Vol.21 No.3

The mason bee Osmia (Helicosmia) latreillei Spinola is one of the dominant species of bees throughout Egypt, and can be found commonly in the Suez Canal Region. The species visits numerous plant species of the family Asteraceae and is considered the most important pollinator of certain crops such as sunflower. This species and some other solitary cavity nesting bees are threatened by fragmentation of their nesting habitats. Several attempts were made to establish and propagate O. latreillei, and success was achieved for re-nesting it in various artificial materials such as wood and polystyrene with rolled paper straws. These artificial nests were established at the conservation area of the Bee Research Centre, Suez Canal University, in order to study the nesting behavior and biology of O. latreillei under artificial conditions and to document their natural enemies. Biologically, there was no significance difference between the life cycle of O. latreillei under natural and artificial nesting conditions. This solitary bee was univoltine, individuals active only during Spring, and attacked by diverse enemies, with Stelis (Stelis) murina Pérez and chrysidid wasps considered the two most major pests of this wild bee species.

Photoreactivity and Thermogravimetry of Copper(II) Complexes of N-Salicylideneaniline and Its Derivatives

Osman, Ahmed H.,Aly, Aref A.M.,El-Mottaleb, Mohamed Abd,Gouda, Gamal A.H. Korean Chemical Society 2004 Bulletin of the Korean Chemical Society Vol.25 No.1

$Cu^{II}$-complexes of N-salicylideneaniline and its derivatives were not light sensitive in most solvents such as acetonitrile. A photo-decomposition occurred upon irradiation in halocarbon solvents such as $CHCl_3$. It has been suggested that such photoreactivity is attributed to the reactivity of charge-transfer to solvent (CTTS) excited state attained upon irradiation. A mechanism has been proposed to account for the results obtained. The complexes have been thermally analysed in nitrogen and static air using thermogravimetry (TG) and derivative thermogravimetry (DTG). The thermal degradation of the complexes proceeds in two or three stages. The kinetic parameters obtained from the Coats-Redfern and Horowitz-Metzger equations show the kinetic compensation effect.

Novel nano-Fe3O4-encapsulated-dioctylphthalate and linked-triethylenetetramine sorbents for magnetic solid phase removal of heavy metals

Mohamed E. Mahmoud,Amr A. Yakout,Kholoud H. Hamza,Maher M. Osman 한국공업화학회 2015 Journal of Industrial and Engineering Chemistry Vol.25 No.-

A simple and solvent-free method is proposed for synthesis of novel magnetic nano-sorbents. Dioctyl phthalate (DOP) was used to encapsulate nano-Fe3O4 and produce a nano-Fe3O4-DOP sorbent. This was treated with triethylenetetramine (TETA) in another solvent-free procedure for the formation of a novel nano-Fe3O4-DOP-TETA. The synthesized nano-sorbents were characterized by FT-IR, TGA, SEM and HRTEM (3.0–12.0 nm). The magnetic solid phase sorption characteristics were studied and optimized. The potential applications of these magnetic solid phase extractors for removal of Ni(II), Cd(II) and Pb(II) from drinking tap water, industrial wastewater and sea water samples were accomplished using a multi-stage micro-column technique

Photoreactivity and Thermogravimetry of Copper(II) Complexes of N-Salicylideneaniline and Its Derivatives

Ahmed H. Osman*,Aref A. M. Aly,Mohamed Abd El-Mottaleb,Gamal A. H. Gouda 대한화학회 2004 Bulletin of the Korean Chemical Society Vol.25 No.1

Synthesis of highly efficient asphalt-based carbon for adsorption of polycyclic aromatic hydrocarbons and diesel from emulsified aqueous phase

Alissa Faisal M.,Mohammed Dauda,Osman Abdalghaffar M.,Basheer Chanbasha,Siddiqui Mohammad Nahid,Al-Arfaj Abdurrahman A.,Suliman Munzir H. 한국탄소학회 2020 Carbon Letters Vol.30 No.5

This work reports the syntheses of an inexpensive and efcient asphalt-derived mesoporous carbon (AdMC) as an adsorbent. The adsorbent was activated with potassium hydroxide to increase its surface area and then characterized by SEM–EDS, FT-IR, and BET. The adsorption properties of AdMC were evaluated for the adsorptive removal of eleven Poly Aromatic Hydrocarbons (PAHs) and diesel from water samples. The prepared AdMC showed very high surface areas and high micropore volumes equal to 2316 m2 /g and 1.2 cm3 /g, respectively. Various experimental conditions infuencing the adsorp�tion capacity of eleven PAHs and diesel were investigated. At high concentrations, PAHs and diesel solubility in water is very low. Hence, samples were emulsifed with a surfactant, and then maximum adsorption capacity was investigated. Adsorption profle of individual PAHs was examined using gas chromatography/mass spectrometry analysis followed by liquid–liquid extraction. Total hydrocarbon removal was studied using a total organic analyzer. Asphalt-derived mesoporous sorbent showed an extreme ability to remove PAHs and diesel (average adsorption capacity of 166 mg/g for individual PAHs and diesel (maximum capacity of 1600 mg/g). The experimental results ftted the Langmuir model with a correlation efciency of 0.9853. The results obtained for both adsorbents also matched to pseudo-second-order kinetics, suggesting that the adsorp�tion of PAHs and diesel is chemical, monolayer, and homogeneous process.

Response of Triple Negative Breast Cancer to Neoadjuvant Chemotherapy: Correlation between Ki-67 Expression and Pathological Response

Elnemr, Gamal M,El-Rashidy, Ahmed H,Osman, Ahmed H,Issa, Lotfi F,Abbas, Osama A,Al-Zahrani, Abdullah S,El-Seman, Sheriff M,Mohammed, Amrallah A,Hassan, Abdelghani A Asian Pacific Journal of Cancer Prevention 2016 Asian Pacific journal of cancer prevention Vol.17 No.2

Triple-negative breast cancers constitute about 15% of all cases, but despite their higher response to neoadjuvant chemotherapy, the tumors are very aggressive and associated with a poor prognosis as well as a higher risk of early recurrence. This study was retrospectively performed on 101 patients with stage II and III invasive breast cancer who received 6-8 cycles of neo-adjuvant chemotherapy. Out of the total, 23 were in the triple negative breast cancer subgroup. Nuclear Ki-67 expression in both the large cohort group (n=101) and triple negative breast cancer subgroup (n=23) and its relation to the pathological response were evaluated. The purpose of the study was to identify the predictive value of nuclear protein Ki-67 expression among patients with invasive breast cancers, involving the triple negative breast cancer subgroup, treated with neoadjuvant chemotherapy in correlation to the rate of pathological complete response. The proliferation marker Ki-67 expression was highest in the triple negative breast cancer subgroup. No appreciable difference in the rate of Ki-67 expression in triple negative breast cancer subgroup using either a cutoff of 14% or 35%. Triple negative breast cancer subgroup showed lower rates of pathological complete response. Achievement of pathological complete response was significantly correlated with smaller tumor size and higher Ki-67 expression. The majority of triple negative breast cancer cases achieved pathological partial response. The study concluded that Ki-67 is a useful tool to predict chemosensitivity in the setting of neoadjuvant chemotherapy for invasive breast cancer but not for the triple negative breast cancer subgroup.

Low Contrast and Low kV CTA Before Transcatheter Aortic Valve Replacement: A Systematic Review

Spencer C. Lacy,Mina M. Benjamin,Mohammed Osman,Mushabbar A. Syed,Menhel Kinno 한국심초음파학회 2023 Journal of Cardiovascular Imaging (J Cardiovasc Im Vol.31 No.2

BACKGROUND: Minimizing contrast dose and radiation exposure while maintaining image quality during computed tomography angiography (CTA) for transcatheter aortic valve replacement (TAVR) is desirable, but not well established. This systematic review compares image quality for low contrast and low kV CTA versus conventional CTA in patients with aortic stenosis undergoing TAVR planning. METHODS: We performed a systematic literature review to identify clinical studies comparing imaging strategies for patients with aortic stenosis undergoing TAVR planning. The primary outcomes of image quality as assessed by the signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were reported as random effects mean difference with 95% confidence interval (CI). RESULTS: We included 6 studies reporting on 353 patients. There was no difference in cardiac SNR (mean difference, −1.42; 95% CI, −5.71 to 2.88; p = 0.52), cardiac CNR (mean difference, −3.83; 95% CI, −9.98 to 2.32; p = 0.22), aortic SNR (mean difference, −0.23; 95% CI, −7.83 to 7.37; p = 0.95), aortic CNR (mean difference, −3.95; 95% CI, −12.03 to 4.13; p = 0.34), and ileofemoral SNR (mean difference, −6.09; 95% CI, −13.80 to 1.62; p = 0.12) between the low dose and conventional protocols. There was a difference in ileofemoral CNR between the low dose and conventional protocols with a mean difference of −9.26 (95% CI, −15.06 to −3.46; p = 0.002). Overall, subjective image quality was similar between the 2 protocols. CONCLUSIONS: This systematic review suggests that low contrast and low kV CTA for TAVR planning provides similar image quality to conventional CTA.