Liquid and vapour-phase antifungal activities of selected essential oils against candida albicans: microscopic observations and chemical characterization of cymbopogon citratus

<p>Abstract</p> <p>Background</p> <p>Use of essential oils for controlling <it>Candida albicans </it>growth has gained significance due to the resistance acquired by pathogens towards a number of widely-used drugs. The aim of this study was to test the antifungal activity of selected essential oils against <it>Candida albicans </it>in liquid and vapour phase and to determine the chemical composition and mechanism of action of most potent essential oil.</p> <p>Methods</p> <p>Minimum Inhibitory concentration (MIC) of different essential oils in liquid phase, assayed through agar plate dilution, broth dilution & 96-well micro plate dilution method and vapour phase activity evaluated through disc volatilization method. Reduction of <it>C. albicans </it>cells with vapour exposure was estimated by kill time assay. Morphological alteration in treated/untreated <it>C. albicans </it>cells was observed by the Scanning electron microscopy (SEM)/Atomic force microscopy (AFM) and chemical analysis of the strongest antifungal agent/essential oil has been done by GC, GC-MS.</p> <p>Results</p> <p>Lemon grass (<it>Cymbopogon citratus</it>) essential oil exhibited the strongest antifungal effect followed by mentha (<it>Mentha piperita</it>) and eucalyptus (<it>Eucalyptus globulus</it>) essential oil. The MIC of lemon grass essential oil in liquid phase (288 mg/l) was significantly higher than that in the vapour phase (32.7 mg/l) and a 4 h exposure was sufficient to cause 100% loss in viability of <it>C. albicans </it>cells. SEM/AFM of <it>C. albicans </it>cells treated with lemon grass essential oil at MIC level in liquid and vapour phase showed prominent shrinkage and partial degradation, respectively, confirming higher efficacy of vapour phase. GC-MS analysis revealed that lemon grass essential oil was dominated by oxygenated monoterpenes (78.2%); α-citral or geranial (36.2%) and β-citral or neral (26.5%), monoterpene hydrocarbons (7.9%) and sesquiterpene hydrocarbons (3.8%).</p> <p>Conclusion</p> <p>Lemon grass essential oil is highly effective in vapour phase against <it>C. albicans</it>, leading to deleterious morphological changes in cellular structures and cell surface alterations.</p

The correction of ETV6/RUNX1 translocation in acute lymphocytic leukemia cells: a new gene targeting system by homologous recombination mechanism

Regarding the uncertainty of the exact cause of the acute lymphocytic leukemia (ALL) caused by ETV6-RUNX1t(12;21) translocation, correcting genes of the ETV6 and RUNX1 in ETV6/RUNX1 fusion gene simultaneously on chromosome 12 may be effective in reducing leukemia malignancy. Thus, we designed an homologous recombination (HR) plasmid to target of the ETV6/RUNX1 fusion gene in the REH cell line containing the ETV6-RUNX1t(12;21) translocation. Cells were cultured and transfected by HR plasmid. The presence of the replacement cassette at specific location in the ETV6/RUNX1 fusion gene was verified by PCR and sequencing method. A quantitative gene expression assay was performed to evaluate changes in expression of ETV6, RUNX1, and ETV6/RUNX1 genes following editing. The cell viability was measured by trypan blue staining. The expression of the ETV6 gene was significantly increased in modified cells than unmodified cells by 10.9-fold. In contrast, the expression of the ETV6-RUNX1 fusion gene was significantly decreased in the modified cells compared with unmodified cells by 0.26-fold. The expression of the RUNX1 gene had no significant difference between modified and unmodified cells. The survival rate of edited cells was significantly decreased than unedited cells (p = 013). We designed a gene targeting system based on HR method to correct genes of ETV6 and RUNX1 simultaneously in ETV6/RUNX1 fusion gene on chromosome 12 containing ETV6-RUNX1t(12;21) translocation. The modification of this translocation may lead to reducing effects of the fusion gene�s damaging and the dosage compensation related to ETV6 and RUNX1 genes and subsequently reduce the effects of leukemia. This targeting system may open a window for treating leukemia as ex vivo. © 2019, Institute of Plant Genetics, Polish Academy of Sciences, Poznan

Studying the power of the integrative weaning index in predicting the success rate of the spontaneous breathing trial in patients under mechanical ventilation

Background and Aims: The use of weaning predictive indicators can avoid early extubation and wrongful prolonged mechanical ventilation. This study aimed to determine the power of the integrative weaning index (IWI) in predicting the success rate of the spontaneous breathing trial (SBT) in patients under mechanical ventilation. Materials and Methods: In this prospective study, 105 patients undergoing mechanical ventilation for over 48 h were enrolled. Before weaning initiation, the IWI was calculated and based on the defined cutoff point (≥25), the success rate of the SBT was predicted. In case of weaning from the device, 2-h SBT was performed and the physiologic and respiratory indices were continuously studied while being intubated. If they were in the normal range besides the patient's tolerance, the test was considered as a success. The result was then compared with the IWI and further analyzed. Results: The SBT was successful in 90 (85.7%) and unsuccessful in 15 (14.3%) cases. The difference between the true patient outcome after SBT, and the IWI prediction was 0.143 according to the Kappa agreement coefficient (P < 0.001). Moreover, regarding the predictive power, IWI had high sensitivity (95.6%), specificity (40%), positive and negative predictive values (90.5% and 60), positive and negative likelihood ratios (1.59 and 0.11), and accuracy (86.7%). Conclusion: The IWI as a more objective indicator has acceptable accuracy and power for predicting the 2-h SBT result. Therefore, in addition to the reliable prediction of the final weaning outcome, it has favorable power to predict if the patient is ready to breathe spontaneously as the first step to weaning