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.

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.