scholarly journals Simple In Vitro Assay for Determining the Sensitivity of Plasmodium vivax Isolates from Fresh Human Blood to Antimalarials in Areas where P. vivax Is Endemic

2003 ◽  
Vol 47 (1) ◽  
pp. 170-173 ◽  
Author(s):  
Bruce M. Russell ◽  
Rachanee Udomsangpetch ◽  
Karl H. Rieckmann ◽  
Barbara M. Kotecka ◽  
Russell E. Coleman ◽  
...  

ABSTRACT The aim of this study was to develop a simple, field-practical, and effective in vitro method for determining the sensitivity of fresh erythrocytic Plasmodium vivax isolates to a range of antimalarials. The method used is a modification of the standard World Health Organization (WHO) microtest for determination of P. falciparum drug sensitivity. The WHO method was modified by removing leukocytes and using a growth medium supplemented with AB+ serum. We successfully carried out 34 in vitro drug assays on 39 P. vivax isolates collected from the Mae Sod malaria clinic, Tak Province, Thailand. The mean percentage of parasites maturing to schizonts (six or more merozoites) in control wells was 66.5% ± 5.9% (standard deviation). This level of growth in the control wells enabled rapid microscopic determination (5 min per isolate per drug) of the MICs of chloroquine, dihydroartemisinin, WR238605 (tafenoquine), and sulfadoxine. P. vivax was relatively sensitive to chloroquine (MIC = 160 ng/ml, 50% inhibitory concentration [IC50] = 49.8 ng/ml) and dihydroartemisinin (MIC = 0.5 ng/ml, IC50 = 0.47 ng/ml). The poor response of P. vivax to both tafenoquine (MIC = 14,000 ng/ml, IC50 = 9,739 ng/ml) and sulfadoxine (MIC = 500,000 ng/ml, IC50 = 249,000 ng/ml) was due to the slow action of these drugs and the innate resistance of P. vivax to sulfadoxine. The in vitro assay developed in our study should be useful both for assessing the antimalarial sensitivity of P. vivax populations and for screening new antimalarials in the absence of long-term P. vivax cultures.

PLoS ONE ◽  
2010 ◽  
Vol 5 (12) ◽  
pp. e14275 ◽  
Author(s):  
Rana Chattopadhyay ◽  
Soundarapandian Velmurugan ◽  
Chinnamma Chakiath ◽  
Lucy Andrews Donkor ◽  
Wilbur Milhous ◽  
...  

1968 ◽  
Vol 20 (03/04) ◽  
pp. 384-396 ◽  
Author(s):  
G Zbinden ◽  
S Tomlin

SummaryAn in vitro system is described in which adhesion of blood platelets to washed and tannic acid-treated red cells was assayed quantitatively by microscopic observation. ADP, epinephrine and TAME produced a reversible increase in platelet adhesiveness which was antagonized by AMP. With Evans blue, polyanetholsulfonate, phthalanilide NSC 38280, thrombin and heparin at concentrations above 1-4 u/ml the increase was irreversible. The ADP-induced increase in adhesiveness was inhibited by sodium citrate, EDTA, AMP, ATP and N-ethylmaleimide. EDTA, AMP and the SH-blocker N-ethylmaleimide also reduced spontaneous platelet adhesion to red cells. No significant effects were observed with adenosine, phenprocoumon, 5-HT, phthalanilide NSC 57155, various estrogens, progestogens and fatty acids, acetylsalicylic acid and similarly acting agents, hydroxylamine, glucose and KCN. The method may be useful for the screening of thrombogenic and antithrombotic properties of drugs.


2020 ◽  
Vol 11 (SPL1) ◽  
pp. 1278-1285
Author(s):  
Mohamed Yafout ◽  
Amine Ousaid ◽  
Ibrahim Sbai El Otmani ◽  
Youssef Khayati ◽  
Amal Ait Haj Said

The new SARS-CoV-2 belonging to the coronaviruses family has caused a pandemic affecting millions of people around the world. This pandemic has been declared by the World Health Organization as an international public health emergency. Although several clinical trials involving a large number of drugs are currently underway, no treatment protocol for COVID-19 has been officially approved so far. Here we demonstrate through a search in the scientific literature that the traditional Moroccan pharmacopoeia, which includes more than 500 medicinal plants, is a fascinating and promising source for the research of natural molecules active against SARS-CoV-2. Multiple in-silico and in-vitro studies showed that some of the medicinal plants used by Moroccans for centuries possess inhibitory activity against SARS-CoV or SARS-CoV-2. These inhibitory activities are achieved through the different molecular mechanisms of virus penetration and replication, or indirectly through stimulation of immunity. Thus, the potential of plants, plant extracts and molecules derived from plants that are traditionally used in Morocco and have activity against SARS-CoV-2, could be explored in the search for a preventive or curative treatment against COVID-19. Furthermore, safe plants or plant extracts that are proven to stimulate immunity could be officially recommended by governments as nutritional supplements.


Author(s):  
Lara Bittmann

On December 31, 2019, WHO was informed of cases of pneumonia of unknown cause in Wuhan City, China. A novel coronavirus was identified as the cause by Chinese authorities on January 7, 2020 and was provisionally named "2019-nCoV". This new Coronavirus causes a clinical picture which has received now the name COVID-19. The virus has spread subsequently worldwide and was explained on the 11th of March, 2020 by the World Health Organization to the pandemic.


2018 ◽  
Vol 24 (10) ◽  
pp. 1138-1147
Author(s):  
Bruno Rivas-Santiago ◽  
Flor Torres-Juarez

Tuberculosis is an ancient disease that has become a serious public health issue in recent years, although increasing incidence has been controlled, deaths caused by Mycobacterium tuberculosis have been accentuated due to the emerging of multi-drug resistant strains and the comorbidity with diabetes mellitus and HIV. This situation is threatening the goals of World Health Organization (WHO) to eradicate tuberculosis in 2035. WHO has called for the creation of new drugs as an alternative for the treatment of pulmonary tuberculosis, among the plausible molecules that can be used are the Antimicrobial Peptides (AMPs). These peptides have demonstrated remarkable efficacy to kill mycobacteria in vitro and in vivo in experimental models, nevertheless, these peptides not only have antimicrobial activity but also have a wide variety of functions such as angiogenesis, wound healing, immunomodulation and other well-described roles into the human physiology. Therapeutic strategies for tuberculosis using AMPs must be well thought prior to their clinical use; evaluating comorbidities, family history and risk factors to other diseases, since the wide function of AMPs, they could lead to collateral undesirable effects.


2019 ◽  
Vol 20 (14) ◽  
pp. 1203-1212
Author(s):  
Abdelmonaem Messaoudi ◽  
Manel Zoghlami ◽  
Zarrin Basharat ◽  
Najla Sadfi-Zouaoui

Background & Objective: Pseudomonas aeruginosa shows resistance to a large number of antibiotics, including carbapenems and third generation cephalosporin. According to the World Health Organization global report published in February 2017, Pseudomonas aeruginosa is on the priority list among resistant bacteria, for which new antibiotics are urgently needed. Peptidoglycan serves as a good target for the discovery of novel antimicrobial drugs. Methods: Biosynthesis of peptidoglycan is a multi-step process involving four mur enzymes. Among these enzymes, UDP-N-acetylmuramate-L-alanine ligase (MurC) is considered to be an excellent target for the design of new classes of antimicrobial inhibitors in gram-negative bacteria. Results: In this study, a homology model of Pseudomonas aeruginosa MurC ligase was generated and used for virtual screening of chemical compounds from the ZINC Database. The best screened inhibitor i.e. N, N-dimethyl-2-oxo-2,3-dihydro-1H-1,3-benzodiazole-5-sulfonamide was then validated experimentally through inhibition assay. Conclusion: The presented results based on combined computational and in vitro analysis open up new horizons for the development of novel antimicrobials against this pathogen.


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