Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0024530 (malaria)
 44,886 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The ompA genes of Escherichia coli and Shigella dysenteriae have been used to construct a group of enterobacterial surface expression vectors for foreign genes. Linker oligonucleotides were inserted into the sequence corresponding to the third or fourth outer domain to allow in-frame sandwich fusion of foreign genes or epitopes into ompA. Influenza haemagglutinin was inserted without its leader peptide and anchor sequences and shown to be transferred as an ompA fusion protein to the bacterial surface in large amounts. The stability of this system depends on the stem structure (i.e. the bottom part) of the haemagglutinin unit which apparently initiates the folding process that extends into the ompA segment. This fusion construct can be used as a vector system and has been used to transfer to the bacterial surface several other proteins inserted into it, including beta-galactosidase, foot-and-mouth disease virus (FMDV) and malaria antigens. All are exported from the cytoplasm across both the inner and outer membranes to become exposed on the bacterial surface. Very hydrophobic segments or inserts with distinct secondary structures, such as the capsid protein, VP1 of FMDV, will, however, block this process.
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PMID:OmpA fusion proteins for presentation of foreign antigens on the bacterial outer membrane. 779 62

Human blood can be divided into groups, which is a method of blood classification based on the presence or absence of inherited erythrocyte surface antigens that can elicit immune response. According to the International Society of Blood Transfusion, there are 341 blood group antigens collected in 35 blood group systems. These antigens can be proteins, glycoproteins or glycosphingolipids, and function as transmembrane transporters, ion channels, adhesion molecules or receptors for other proteins. The majority of blood group antigens is present also on another types of cells. Due to their localization on the surface of cells, blood group antigens can act as receptors for various pathogens or their toxins, such as protozoa (malaria parasites), bacteria (Helicobacter pylori, Vibrio cholerae and Shigella dysenteriae) and viruses (Noroviruses, Parvoviruses, HIV). If the presence of group antigen (or its variant which arised due to mutation) is beneficial for the host (e.g. because pathogens are not able to bind to the cells), the blood group may become a selection trait, leading to its dissemination in the population exposed to that pathogen. There are thirteen blood group systems that can be related to pathogen resistance, and it seems that the particular influence was elicit by malaria parasites. It is generally thought that the high incidence of blood groups such as O in the Amazon region, Fy(a-b-) in Africa and Ge(-) in Papua-New Guinea is the result of selective pressure from malaria parasite. This review summarizes the data about relationship between blood groups and resistance to pathogens.
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PMID:[Blood groups - minuses and pluses. Do the blood group antigens protect us from infectious diseases?]. 2620 87

Leaves and roots of Acanthospermum australe (Asteraceae) have been used in Brazilian folk medicine for the treatment of various ailments including diarrhea, skin diseases, blennorrhagia, dyspepsia, parasitic worms and malaria. The aim of study was to characterize the chemical profiles of the aqueous and hydroalcoholic extracts of leaves and roots of A. australe, and to evaluate their antimicrobial activities against diarrhea-inducing bacteria (Enterococcus faecalis, Shigella dysenteriae and Yersinia enterocolitica), as well as their cytotoxic properties. Aqueous leaf extracts were obtained by infusion, while aqueous root extracts were obtained by decoction. The hydroalcoholic leaf and root extracts were prepared by maceration in 90% ethanol for 3 days. Antimicrobial activity was assessed using standard techniques and cytotoxicity was evaluated using Chinese hamster ovary cells CHO-K1. Chemical analysis revealed the presence of tannins, flavonoids, saponins and phenolic compounds in the extracts. Although root extracts were not effective against E. faecalis, leaf extracts at concentrations of 20 mg/mL exhibited bactericidal activities against this microorganism. The hydroalcoholic root extract was unique in presenting a bactericidal effect against S. dysenteriae. None of the extracts showed bacteriostatic or bactericidal activities against Y. enterocolitica. The results presented herein demonstrate that the Gram-positive E. faecalis and the Gram-negative S. dysenteriae were susceptible to A. australe extracts, although bacteriostatic/bactericidal activities were only observed at concentrations considered too high for clinical application. Our results support the ethnopharmacological use of A. australe in the treatment of gastrointestinal disorders, particularly diarrhea caused by infectious bacteria, although further studies are required to determine the anti-diarrhea effects and the toxicities of the extracts in vivo.
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PMID:Effectiveness of aqueous and hydroalcoholic extracts of Acanthospermum australe (Loefl.) Kuntze against diarrhea-inducing bacteria. 2931 52