Antimicrobial activity of the newly recorded red alga Grateloupia doryphora collected from the Eastern Harbor, Alexandria, Egypt.

AIMS: To screen the newly recorded alga Grateloupia doryphora in the Egyptian Mediterranean Sea for antimicrobial activity. METHODS AND RESULTS: Algal samples were collected from the Eastern Harbor, Alexandria, Egypt during summer (2016 and 2017). The dry and fresh methanolic, ethanolic and ethyl acetate algal extracts were tested against Bacillus subtilis, Enterococcus faecalis and Staphylococcus aureus as Gram-positive bacteria, Escherichia coli, Pseudomonas aeruginosa as Gram-negative bacteria and one yeast strain Candida albicans. A three-way analysis of variance showed significant differences based on the algal form, type of solvents and microbial species. The fresh methanolic and ethyl acetate extracts had equal effects on the tested pathogens with means of 14·44 and 15·16 respectively. However, the fresh algal extract was more effective on all the tested organisms than the dried material, except for ethyl acetate and ethanol extract on Bacillus subtilis (31 and 23 mm) respectively. In fact, P. aeruginosa was the most susceptible organism to the fresh algal extract, with much higher inhibition zones (30, 27 and 28 mm) for mehanolic, ethyl acetate and ethanolic extracts, respectively, compared with the dried ones. Furthermore, C. albicans was sensitive to the fresh algal extracts only. Compared with the commercial antibiotics piperacillin, rifampicin, cephalexin, metronidazole and fusidic acid tested against the same microbes, the results showed in general lower or comparable inhibition zones than algal extracts. The GC-MS fresh methanolic and ethyl acetate algal extracts revealed the presence of many potent compounds, with palmitic acid and 2-tetradecyloxirane as the common constituents in both extracts. The commercial palmitic acid was tested against the same microbes with successful elimination of all pathogens. CONCLUSIONS: Grateloupia doryphora showed broad spectrum of antimicrobial activity against the tested microbial species in this study. SIGNIFICANCE AND IMPACT OF THE STUDY: The alga can be useful in industry of pharmaceutical products. On the other hand, its usage in this domain can be a suitable solution to its introduction in our coasts.

Subchronic toxicity of Nile tilapia with different exposure routes to Microcystis aeruginosa: Histopathology, liver functions, and oxidative stress biomarkers.

BACKGROUND: Toxic cyanobacterial blooms (Microcystis aeruginosa contains microcystins [MCs]) have been reported to induce clinicopathological alterations as well as different oxidative stress in aquatic biota. AIM: Three-week subchronic exposure experiment was carried out on Nile tilapia, to determine their effects on fish behavior, tissues, liver functions, antioxidant enzymes, and lipid peroxidation. MATERIALS AND METHODS: Fish were exposed to four main treatments; orally fed diet plus toxic cells of M. aeruginosa (containing 3500 µg/g MC-LR), immersion in 500 µg MC-LR/L, intraperitoneal injection of M. aeruginosa MC-LR with a dose of 0.1 ml of extracted toxin at a dose of 200 µg/kg bwt, and the fourth one served as a control group, then the fish were sacrificed at the end of 3rd week of exposure. RESULTS: The results revealed no recorded mortality with obvious behavioral changes and an enlarged liver with the congested gall bladder. Histopathology demonstrated fragmentation, hyalinization, and necrosis of the subcutaneous musculature marked fatty degeneration, and vacuolation of hepatopancreatic cells with adhesion of the secondary gill lamellae associated with severe leukocytic infiltration. Furthermore, liver functions enzymes (aspartate aminotransferase and alanine aminotransferase, and the activities of glutathione peroxidase, glutathione reductase, lipid peroxidase, and catalase enzymes) were significantly increased in all treatments starting from the 2nd week as compared to the control levels. CONCLUSION: In this context, the study addresses the possible toxicological impacts of toxic M. aeruginosa contain MC-LR to Nile tilapia, and the results investigated that MC-LR is toxic to Nile tilapia in different routes of exposure as well as different doses.

Phyto-dewatering of sewage sludge using Panicum repens L.

Experiments in the field environment have been conducted to study the growth of Panicum repens L., an aquatic plant, in the sewage sludge matrix. The experiments were also carried out to investigate the ability of this plant to dewater sewage sludge to increase the capacity of conventional drying beds. In addition, the ability of Panicum repens L. to reduce the sludge contents of certain elements (copper (Cu), Iron (Fe), Sodium (Na), lead (Pb), and Zinc (Zn)) was also investigated. All experiments were carried out in batch reactors. Different plant coverage densities were tested (0.00 to 27.3 kg/m2). The liquid sewage sludge was collected from a wastewater treatment plant in Helwan city, Cairo Governorate, Egypt. The collected sludge represents a mixture of the primary sludge and waste activated sludge before discharging into drying beds.

Functional mandibular deformation in edentulous subjects treated with dental implants.

PURPOSE: The purpose of this study was to measure medial convergence, dorsoventral shear, and corporal rotation in the human mandible. MATERIALS AND METHODS: Measurements were made using custom-fabricated strain gauge displacement transducers in 6 edentulous subjects who had been treated with mandibular endosseous dental implants. These were mounted on the most distal of the mandibular implants on each side, and measurements were made in real time using a multichannel analogue/digital converter and a personal computer for data storage and analysis. Measurements were made while the implants were loaded, and the subjects opened and closed their mouths and made lateral mandibular excursions. Medial convergence was measured as a linear change at the site of the most distal implant. Dorsoventral shear was expressed as a relative rotation of the right and left mandibular bodies projected onto the median sagittal plane, and corporal rotation was expressed as the relative rotation of the most distal implant. RESULTS: Jaw deformation was found to occur immediately on opening and was related to closing forces and jaw position. Medial convergence of up to 41 microns was observed, with values for corporal rotation of up to 6 degrees and dorsoventral shear of up to 19 degrees. CONCLUSION: The study demonstrated clinically for the first time 3 different and simultaneous patterns of functional mandibular deformation.

Viability, attachment efficiency, and xenobiotic metabolizing enzyme activities are well maintained in EDTA isolated rat liver parenchymal cells after hypothermic preservation for up to 3 days in University of Wisconsin solution.

Rat liver parenchymal cells were isolated by EDTA perfusion and were subsequently purified by Percoll centrifugation. The freshly isolated liver cells had a mean viability of 95% as judged by trypan blue exclusion. Isolated liver parenchymal cells were then stored at 0 degrees C for up to 1 wk in University of Wisconsin solution (UW). During this hypothermic preservation, the viability was only slightly reduced to 92% after 1 d and to 85% after 3 d at 0 degrees C. Thereafter, the viability decreased rapidly. After cold storage for up to 3 d, it was possible to use the parenchymal liver cells either in short-term suspension or in cell culture. The attachment efficiency in cell culture was the same for freshly isolated liver cells (84%) and after 2 d cold preservation (81%). The cytochrome P450 content and the enzyme activities of soluble epoxide hydrolase, UDP-glucuronosyl transferase, phenol sulfotransferase, and glutathione S-transferase were not significantly different between freshly isolated cells and cells after 3 d of hypothermic preservation. Furthermore, freshly isolated and intact liver cells stored for 3 d were used in the cell-mediated Salmonella mutagenicity test as a metabolizing system. Both fresh and stored liver parenchymal cells metabolized benzo(a)pyrene,2-aminoanthracene, and cyclophosphamide to their ultimate mutagens.(ABSTRACT TRUNCATED AT 250 WORDS)

Xenobiotic metabolizing enzyme activities and viability are well preserved in EDTA-isolated rat liver parenchymal cells after cryopreservation.

Rat liver parenchymal cells (PC) were isolated by EDTA perfusion and were purified by a subsequent Percoll centrifugation. The isolated PC had a viability of 95%, as judged by trypan blue exclusion. Freshly isolated PC were cryopreserved with an optimized protocol in a computer-controlled freezer. After thawing, the PC still retained a viability of 89%. The activities of representative xenobiotic metabolizing enzymes were compared between freshly isolated and cryopreserved PC after thawing. The cytochrome P450 content and the cytochrome P450 2C11 isoenzyme activity, determined by hydroxylation of testosterone in intact cells, were not affected by the cryopreservation. The following phase II enzyme activities were also well maintained after cryopreservation: Phenol sulfotransferase (92%), 1-naphthol UDP-glucuronosyl transferase (95%), soluble epoxide hydrolase (87%), and glutathione S-transferase (88%), determined with broad spectrum substrate 1-chloro-2,4-dinitrobenzene. However, there was a significant decrease in plating efficiency between freshly isolated (86%) and cryopreserved (57%) PC when they were cultured. The initial quality of the freshly isolated PC is decisive for the success of cryopreservation. These results support the use of cryopreserved PC in pharmacology and toxicology with the aim to reduce the number of experimental animals used.