Antidiabetic potential of methanol extracts from leaves of Piper umbellatum L.and Persea americana Mill

Objective:To determine inhibitory activity of methanolic leaf extract of Piper umbellatum and Persea americana (P.americana) (traditionally used in Cameroon against diabetes) on α-glucosidase,β-glucosidase,maltase-gluconmylase,aldose reductase and aldehyde reductase activities,enzymes involved in starch digestion or diabetic complications.Methods:The methanol extracts from Piper umbellatum and P.americana were prepared by maceration.To assess relative efficacy of these extracts,the determination of concentrations that were needed to inhibit 50％ of enzyme activity was done,whereas,gas chromatography-mass spectrum was used to identify components from extracts that may be responsible for the activities.Resullts The tested extracts strongly inhibited α-glucosidase,maltase-glucoamylase,aldose reductase and aldehyde reductase activities with IC50 ranging from (1.07 ± 0.03) to 01.77 + 1.17) μg/mL.Among the tested extracts,P.americana was the most active against sensitive enzymes (IC50 of 1.07 ± 0.03 to 15.63 ± 1.23).But,none of the extracts showed interesting inhibitory effect against β-glucosidase as their percentage inhibitions were less than 16％.From gas chromatographymass spectrum analysis,10 and 8 compounds were identified in Piper umbellatum and P.americana extracts respectively,using NIST library 2014.Conclusions:Results of this study provide the scientific credential for a prospective usage of these plants to treat diabetes.

Regulation of hypnosis in Propofol anesthesia administration based on non-linear control strategy / Controle da hipnose na administração de propofol com base na estratégia de controle não linear

Abstract Continuous adjustment of Propofol in manual delivery of anesthesia for conducting a surgical procedure overburdens the workload of an anesthetist who is working in a multi-tasking scenario. Going beyond manual administration and Target Controlled Infusion, closed-loop control of Propofol infusion has the potential to offer several benefits in terms of handling perturbations and reducing the effect of inter-patient variability. This paper proposes a closed-loop automated drug administration approach to control Depth Of Hypnosis in anesthesia. In contrast with most of the existing research on anesthesia control which makes use of linear control strategies or their improved variants, the novelty of the present research lies in applying robust control strategy i.e. Sliding Mode Control to accurately control drug infusion. Based on the derived patient's model, the designed controller uses measurements from EEG to regulate DOH on Bispectral Index by controlling infusion rate of Propofol. The performance of the controller is investigated and characterized with real dataset of 8 patients undergoing surgery. Results of this in silico study indicate that for all the patients, with 0% overshoot observed, the steady state error lies in between ±5. Clinically, this implies that in all the cases, without any overdose, the controller maintains the desired DOH level for smooth conduction of surgical procedures.

Resumo O ajuste contínuo de propofol na administração manual de anestesia para um procedimento cirúrgico onera a carga de trabalho de anestesistas que trabalham em ambiente multitarefa. Indo além da administração manual e da infusão alvo-controlada (IAC), o controle de circuito fechado da infusão de propofol tem o potencial de oferecer vários benefícios em termos de manejo das perturbações e reduzir o efeito da variabilidade interpaciente. Este artigo propõe uma abordagem para a administração automatizada de drogas em circuito fechado para controlar a profundidade da hipnose (PDH) em anestesia. Em contraste com a maioria das pesquisas existentes sobre o controle da anestesia que usam estratégias de controle linear ou de suas variantes melhoradas, a novidade da presente pesquisa reside na aplicação de uma estratégia de controle consistente; isto é, o Controle por Modos Deslizantes (CMD) para controlar com precisão a infusão da droga. Com base no modelo derivado do paciente, o controlador projetado usa as medições do EEG para regular a PDH no Bispectral Index (BIS), controla a taxa de infusão de propofol. O desempenho do controlador é investigado e caracterizado com um conjunto de dados reais de oito pacientes submetidos à cirurgia. Os resultados deste estudo in silico indicam que, para todos os pacientes, com 0% de excesso observado, o erro de estado estacionário fica entre ± 5. Clinicamente, isso implica que em todos os casos, sem qualquer sobredosagem, o controlador mantém o nível desejado de PDH para a condução tranquila dos procedimentos cirúrgicos.