Design Specifications for an Auxiliary Incision Retractor in Dacryocystorhinostomy Surgeries

It is presented the design specifications for a Retractor Robotic System (RRS) based on the surgical necessities in the incisions procedure for a dacryocystorhinostomy. The specifications are conformed by a mathematical model, the experimental data measured, a modular flexible architecture, energy supplier system, the mechanical group, and the safety system. The specifications suggest that the use of flexible polymeric materials for the RRS provide a mayor adaptability of the system with the biological tissue; so a pneumatic actuator could be a suitable option.This research was funded by CONACYT (Consejo Nacional de Ciencia y Tecnología) Grant No. 86356

In vitro antibiotic and modulatory activity of Mesosphaerum suaveolens (L.) kuntze against candida strains

The emergence of fungal resistance to commercial drugs has been a major problem for the WHO. In this context, research with natural products is promising in the discovery of new active substances. Thus, this work evaluated the antifungal effect of a medicinal plant (i.e., Mesosphaerum suaveolens) against strains of the genus Candida, tested the combined effect with the drug fluconazole, and, finally, determined the phenolic constituents present in the species. Initially, aqueous extracts of leaves (AELMs) and aerial parts (AEAPMs) of the species were prepared. For microbiological assays, the minimum fungicidal concentration was determined by broth microdilution, and the combined effect of fluconazole extracts were verified by sub\u2010inhibitory microdilution concentrations (CFM/8) followed by spectrophotometric readings which were used to determine the IC50. HPLC detected the presence of flavonoids and phenolic acids, detecting eight compounds present in the samples of which caffeic acid and quercetin were major components. The AELMs modulated fluconazole activity since it decreased fluconazole\u2019s IC50 from 7.8 \u3bcg/mL to an IC50 of 4.7 \u3bcg/mL (CA LM 77) and from 28.8 \u3bcg/mL to 18.26 \u3bcg/mL (CA INCQS 40006) for the C. albicans strains. The AEAPMs were able to potentiate the effect of fluconazole more effectively than the AELMs. Such an effect was significant for the 16 \u3bcg/mL concentration for CA LM 77 and 32 \u3bcg/mL for CA INCQS 40006. The AEAPMs as well as the AELMs presented clinically relevant activities for C. tropicalis strains. For the C. tropicalis LM 23 strain, the AEPMs obtained an IC50 of 25 \u3bcg/mL and the AELMs an IC50 of 359.9 \u3bcg/mL

Effect of α-bisabolol and its β-cyclodextrin complex as TetK and NorA efflux pump inhibitors in Staphylococcus aureus strains

Efflux pumps are proteins present in the plasma membrane of bacteria, which transport antibiotics and other compounds into the extracellular medium, conferring resistance. The discovery of natural efflux pump inhibitors is a promising alternative. \u3b1-Bisabolol is a sesquiterpene isolated from several plants such as Matricaria chamomilla L. and has important properties such as antibacterial and anti-inflammatory activity. Currently, the formation of inclusion complexes with \u3b2-Cyclodextrin has been used for improving the physicochemical characteristics of the host molecule. This study evaluated the effect of \u3b1-Bisabolol, in isolation and in complexation with \u3b2-Cyclodextrin, as TetK and NorA efflux pump inhibitors in Staphylococcus aureus strains. The minimum inhibitory concentration (MIC) was determined. Subsequently, inhibitory activity over the pumps was observed by an MIC reduction for the antibiotics, by using subinhibitory concentrations (MIC/8) in combination with tetracycline and norfloxacin. The MIC of the compounds was 651024 \u3bcg/mL. \u3b1-Bisabolol potentiated the action of tetracycline and reduced the MIC of norfloxacin to a clinically relevant concentration. The complexed substance showed synergism however, the effect of the isolated \u3b1-Bisabolol was superior to the complex. These results indicate \u3b1-Bisabolol is a potential substance to be used as an efflux pump inhibitor