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Plasmodium vivax Duffy Binding Protein (PvDBP) is essential for interacting with Duffy antigen receptor for chemokines (DARC) on the surface of red blood cells to allow invasion. Earlier whole genome sequence analyses provided evidence for the duplications of PvDBP . It is unclear whether PvDBP duplications play a role in recent increase of P . vivax in Sudan and in Duffy-negative individuals. In this study, the prevalence and type of PvDBP duplications, and its relationship to demographic and clinical features were investigated. A total of 200 malaria-suspected blood samples were collected from health facilities in Khartoum, River Nile, and Al-Obied. Among them, 145 were confirmed to be P . vivax , and 43 (29.7%) had more than one PvDBP copies with up to four copies being detected. Both the Malagasy and Cambodian types of PvDBP duplication were detected. No significant difference was observed between the two types of duplications between Duffy groups. Parasitemia was significantly higher in samples with the Malagasy-type than those without duplications. No significant difference was observed in PvDBP duplication prevalence and copy number among study sites. The functional significance of PvDBP duplications, especially those Malagasy-type that associated with higher parasitemia, merit further investigations.

Duffy-negatives were previously thought to be immune to Plasmodium vivax infections due to Duffy binding protein’s (PvDBP1) inability to invade erythrocytes lacking Duffy antigen receptor for chemokines (DARC) expression. Nevertheless, reports of P. vivax cases are growing throughout Africa and among Duffy-negative people. Although there are alternative invasion mechanisms by P. vivax , the exact mechanisms in Duffy-negative individuals are unclear. Sudan, with a mixed Duffy-negative and Duffy-positive population, is ideal to study differences between these infections on epidemiological and genetic scales. The goal of this study was to compare Duffy-positive and Duffy-negative infections in Sudanese individuals on epidemiological and genomic scales. We collected epidemiological data and sequenced parasite genomes and found that Duffy-positive individuals had significantly higher parasitemia than Duffy-negatives. Furthermore, Duffy-positive infected P. vivax genomes were much more diverse than Duffy-negatives, across all 14 chromosomes and 44 specific erythrocyte binding gene candidates. Genes of the merozoite surface protein family account for much of the genetic diversity found. Many erythrocyte binding gene candidates are under selection pressure, both positive and negative. Finally, in DBP and RBP genes, as well as TRAg 38, changes in amino acids in the binding regions to a structurally different residue could affect erythrocyte binding affinity and antigenic conformation.

Since December 2019, the world has been facing the outbreak of the SARS-CoV-2 pandemic that has infected more than 149 million and killed 3.1 million people by 27 April 2021, according to WHO statistics. Safety measures and precautions taken by many countries seem insufficient, especially with no specific approved drugs against the virus. This has created an urgent need to fast track the development of new medication against the virus in order to alleviate the problem and meet public expectations. The SARS-CoV-2 3CL main protease (Mpro) is one of the most attractive targets in the virus life cycle, which is responsible for the processing of the viral polyprotein and is a key for the ribosomal translation of the SARS-CoV-2 genome. In this work, we targeted this enzyme through a structure-based drug design (SBDD) protocol, which aimed at the design of a new potential inhibitor for Mpro. The protocol involves three major steps: fragment-based drug design (FBDD), covalent docking and molecular dynamics (MD) simulation with the calculation of the designed molecule binding free energy at a high level of theory. The FBDD step identified five molecular fragments, which were linked via a suitable carbon linker, to construct our designed compound RMH148. The mode of binding and initial interactions between RMH148 and the enzyme active site was established in the second step of our protocol via covalent docking. The final step involved the use of MD simulations to test for the stability of the docked RMH148 into the Mpro active site and included precise calculations for potential interactions with active site residues and binding free energies. The results introduced RMH148 as a potential inhibitor for the SARS-CoV-2 Mpro enzyme, which was able to achieve various interactions with the enzyme and forms a highly stable complex at the active site even better than the co-crystalized reference.

Non-Hodgkin's lymphomas (NHLs) are heterogeneous group of malignant lymphoproliferative disorders. This was a retrospective study aimed to classify NHLs into B cell and T cell types; in addition to demonstrate the histological patterns and correlate it with gender, age and site of the biopsy. The study was conducted in Histopathology Department, National Heath Laboratory, during the period 2007-2010. Formalin fixed paraffin wax embedded tissue blocks which were diagnosed as NHLs by routine Haematoxylin and Eosin (H&E) stain during the period 2000-2008 were used. Haematoxylin and Eosin (H&E) stain were done. Immunohistochemistry stains performed according to Dako cytomation protocol 2007. Lymphoid markers which were used in this study are CD45 (LCA), CD20 (B cell marker), CD3 (T cell marker), CD15 and CD 30. Epithelial marker which was used is CK MNF116. The total number of samples collected was 66; two of them were excluded because of poor processing. Another two specimens were excluded because they are non-reactive with lymphoid markers. The remaining 62 specimens were confirmed to be NHLs and classified into B cell and T cell types. The study showed that B cell NHLs represented 87.1% while T cell NHLs were 12.9%. The Male: Female ratio was 1.6:1. The major affected age group was (47-67) years (38.1% of all specimens). The most frequent histological grade was intermediate grade NHLs (27% of all specimens). The most common site of NHLs in this study is the lymph node (40% of all specimens) followed by stomach (19.4%). Extranodal locations are the most common sites affected with T cell NHLs. In conclusion; this study confirmed the fundamental role of immunohistochemistry in diagnosis and classification of NHLs.