Chemical Assessment and Antimicrobial Activity of Solvent Extracts from Kalanchoe densiflora

ABSTRACT Kalanchoe densiflora leaves were sequentially extracted using hexane, ethyl acetate, chloroform, acetone and methanol. The solvents were evaporated through rotor evaporation under vacuum to yield five extracts. The extracts were then subjected to chemical and photochemical analyses to identify the components present and their functional groups. In addition the extracts were tested for antimicrobial activities against eight micro-organisms; Bacillus subtilis, Candida albicans, Escherichia coli, Klebsiella pneumoniae, Salmonella typhi, Staphylococcus aureus, Proteus mirabilis and Pseudomonas aeruginosa. The extracts were found to posses' tannins, saponins, terpenoids, flavonoids and cardiac glycosides. It was also found that unsaturated bonds, carboxyl groups and aldehydes were present in the extracts. In addition, the extracts showed antimicrobial activity against Bacillus spp, E. coli and P. aeruginosa as indicated by presence of zones of inhibition. Acetonic and methanolic extracts were sensitive to P. aeruginosa, Bacillus spp. and S. aureus while hexane extract was highly sensitive to E.coli. K. densiflora extracts was found to have broad antimicrobial effect since it was active against gram positive and gram negative bacteria. Crude extracts from K. densiflora can be used in control of diseases such as; acute enteritis, pneumonias and opportunistic diseases amongst other diseases caused by these microorganisms

The ASOS Surgical Risk Calculator: development and validation of a tool for identifying African surgical patients at risk of severe postoperative complications

Background: The African Surgical Outcomes Study (ASOS) showed that surgical patients in Africa have a mortality twice the global average. Existing risk assessment tools are not valid for use in this population because the pattern of risk for poor outcomes differs from high-income countries. The objective of this study was to derive and validate a simple, preoperative risk stratification tool to identify African surgical patients at risk for in-hospital postoperative mortality and severe complications. Methods: ASOS was a 7-day prospective cohort study of adult patients undergoing surgery in Africa. The ASOS Surgical Risk Calculator was constructed with a multivariable logistic regression model for the outcome of in-hospital mortality and severe postoperative complications. The following preoperative risk factors were entered into the model; age, sex, smoking status, ASA physical status, preoperative chronic comorbid conditions, indication for surgery, urgency, severity, and type of surgery. Results: The model was derived from 8799 patients from 168 African hospitals. The composite outcome of severe postoperative complications and death occurred in 423/8799 (4.8%) patients. The ASOS Surgical Risk Calculator includes the following risk factors: age, ASA physical status, indication for surgery, urgency, severity, and type of surgery. The model showed good discrimination with an area under the receiver operating characteristic curve of 0.805 and good calibration with c-statistic corrected for optimism of 0.784. Conclusions: This simple preoperative risk calculator could be used to identify high-risk surgical patients in African hospitals and facilitate increased postoperative surveillance. © 2018 British Journal of Anaesthesia. Published by Elsevier Ltd. All rights reserved.Medical Research Council of South Africa gran