Laboratory testing of clinically approved drugs against Balamuthia mandrillaris

Balamuthia mandrillaris is a free-living protist pathogen that can cause life-threatening granulomatous amoebic encephalitis. Given the lack of effective available drugs against B. mandrillaris encephalitis with a mortality rate of more than 90 %, here we screened drugs, targeting vital cellular receptors and biochemical pathways, that are already in approved clinical use for their potential clinical usefulness. Amoebicidal assays were performed by incubating B. mandrillaris with drugs (3 × 10⁵ cells/0.5 mL/well) in phosphate buffered saline for 24 h and viability was determined using Trypan blue exclusion staining. For controls, amoebae were incubated with the solvent alone. To determine whether effects are reversible, B. mandrillaris were pre-exposed to drugs for 24 h, washed twice, and incubated with human brain microvascular endothelial cells, which constitute the blood–brain barrier as food source, for up to 48 h. Of the ten drugs tested, amlodipine, apomorphine, demethoxycurcumin, haloperidol, loperamide, prochlorperazine, procyclidine, and resveratrol showed potent amoebicidal effects, while amiodarone and digoxin exhibited minimal effectiveness. When pre-treated with these drugs, no viable trophozoites re-emerged, suggesting that drugs destroyed parasite irreversibly. Based on the in vitro assay, amlodipine, apomorphine, demethoxycurcumin, haloperidol, loperamide, prochlorperazine, procyclidine, and resveratrol are potential antimicrobials for further testing against B. mandrillaris encephalitis. These findings may provide novel strategies for therapy but further research is needed to determine clinical usefulness of aforementioned drugs against granulomatous amoebic encephalitis caused by B. mandrillaris, and other free-living amoebae, such as Acanthamoeba spp., and Naegleria fowleri.     

Fossilized human blood cells from a Hellenistic settlement

The su of human soft tissue over long periods of time after death by mummification is common knowledge. Egyptian and pre-Columbian mummies from America are the best-known examples of this process. The survival of human blood cells, the most fragile of all soft tissue, over a period of about 2200 years by a process of fossilization is a phenomenon which had not been observed previously. Fossilized blood cells were found during the paleopathological examination of skeletons of soldiers buried near a Hellenistic fortress. The fortress had been built on an island in the Arab-Persian Gulf subsequent to the oriental expeditions of Alexander the Great.     

Screening of inhibitors against SARS-CoV-2 spike protein and their capability to block the viral entry mechanism: A viroinformatics study

SARS-CoV-2, previously named 2019 novel coronavirus (2019-nCoV), has been associated with the global pandemic of acute respiratory distress syndrome. First reported in December 2019 in the Wuhan province of China, this new RNA virus has several folds higher transmission among humans than its other family member (SARS-CoV and MERS-CoV). The SARS-CoV-2 spike receptor-binding domain (RBD) is the region mediating the binding of the virus to host cells via Angiotensin-converting enzyme 2 (ACE2), a critical step of viral. Here in this study, we have utilized in silico approach for the virtual screening of antiviral library extracted from the Asinex database against the Receptor binding domain (RBD) of the S1 subunit of the SARS-CoV-2 spike glycoprotein. Further, the molecules were ranked based on their binding affinity against RBD, and the top 15 molecules were selected. The affinity of these selected molecules to interrupt the ACE2-Spike interaction was also studied. It was found that the chosen molecules were demonstrating excellent binding affinity against spike protein, and these molecules were also very effectively interrupting the ACE2-RBD interaction.Furthermore, molecular dynamics (MD) simulation studies were utilized to investigate the top 3 selected molecules' stability in the ACE2-RBD complexes. To the best of our knowledge, this is the first study where molecules' inhibitory potential against the Receptor binding domain (RBD) of the S1 subunit of the SARS-CoV-2 spike glycoprotein and their inhibitory potential against the ACE2-Spike has been studied. We believe that these compounds can be further tested as a potential therapeutic option against COVID-19.     

Microscopy electron scanning of fossilized sickle-cells

In a microscopica electronic scanning follow-up study on human skeletons from the Hellenistic Period in the Arab-Persian Gulf, fossilized sickle-cells were found in the bone marrow of one of the excavated skeletons. The ultrastructure of these cells was compared to that of fossilized normal red blood cells of other skeletons from the same site, and to similar pseudo-pathological structures. The finding of fossilized evidence of sickle-cell anemia of that date is withoutprecedent, and makes an evaluation of related gross-anatomical skeletal changes possible.