{"title":"Is Plasmodium falciparum aldolase useful for rational drug design?","authors":"H Döbeli, C Itin, B Meier, U Certa","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>P. falciparum lacks a functional citric acid cycle. Unlike most tissues of the mammalian host, it is totally dependent on glycolysis for energy generation. A compound which selectively inhibits the parasite's ATP-generating machinery is therefore a potential antimalarial agent. Such a drug may interact in two ways: a) by inhibiting the activity of an enzyme or b) by disturbing the micro-organization of consecutive enzymes in a metabolic pathway. In mammalian tissues the glycolytic pathway involves the cytoskeleton as a matrix to keep phosphofructokinase, aldolase and glyceraldehyde-3-phosphate dehydrogenase in an optimal sterical position for rapid substrate conversion. For instance, these three enzymes bind to the band 3 protein in erythrocytes or to actin in muscle cells. P. falciparum aldolase binds with very high affinity to the band 3 protein of human erythrocyte ghosts. However, the true in vivo site of association is believed to be actin II of P. falciparum. This actin has a sequence element which is almost identical to that of the band 3 aldolase binding site. We therefore suppose that plasmodia exploit a similar matrix organization. If true, the association of these enzymes with the cytoskeleton is a target for novel antimalarials. In contrast to all vertebrate aldolases, P. falciparum and P. berghei aldolases have two neighbouring lysine residues near the carboxy-terminus. We show here that mutagenesis of these basic residues has an effect on the catalytic constants Vmax and KM and moreover, the ability to bind to band 3 is reduced.(ABSTRACT TRUNCATED AT 250 WORDS)</p>","PeriodicalId":7108,"journal":{"name":"Acta Leidensia","volume":"60 1","pages":"135-40"},"PeriodicalIF":0.0,"publicationDate":"1991-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"12983771","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Don't kill the parasite: control the disease.","authors":"J H Playfair, J Taverne, C A Bate","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>It is clear from both laboratory and clinical studies that the blood-stage malaria parasite does not itself directly cause most of the serious complications of the disease, with the possible exception of anaemia. For example, T cell- deprived mice with lethal infections survive longer and mice can be protected against early death by vaccines that appear not to affect parasitaemia. In certain cases antibodies to TNF have the same effect. Clinically it has been known for over 50 years that children in endemic areas develop immunity to the serious toxic aspects of malaria several years before their parasitaemias start to fall. Recent work on the induction of cytokines such as tumour necrosis factor (TNF) by exoantigens of the blood-stage parasite and on the role of cytokines in this and other toxic diseases suggests that an appropriate vaccine might induce antibody that blocks the effect of the exoantigens, thus conferring on young children the anti-disease immunity that normally takes years to appear. Such vaccines might be less hampered by the antigenic variation that makes anti-parasite immunity slow to develop. Characterisation of the molecules involved is a high priority.</p>","PeriodicalId":7108,"journal":{"name":"Acta Leidensia","volume":"60 1","pages":"157-65"},"PeriodicalIF":0.0,"publicationDate":"1991-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"12983774","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Mitosis and meiosis in malarial parasites.","authors":"R E Sinden","doi":"","DOIUrl":"","url":null,"abstract":"","PeriodicalId":7108,"journal":{"name":"Acta Leidensia","volume":"60 1","pages":"19-27"},"PeriodicalIF":0.0,"publicationDate":"1991-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"12983778","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"The science and technology for development programme of the European Community and malaria research.","authors":"S Jepsen","doi":"","DOIUrl":"","url":null,"abstract":"","PeriodicalId":7108,"journal":{"name":"Acta Leidensia","volume":"60 1","pages":"5-7"},"PeriodicalIF":0.0,"publicationDate":"1991-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"12983783","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Veterinary use of ivermectin.","authors":"I H Sutherland","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>Following the development of a unique claim structure encompassing both nematode and arthropod species, ivermectin was first introduced as a veterinary parasiticide in 1981. For cattle(c), sheep(s), horses(h) and pigs(p) injectable(c,s,p), oral(c,s,h) and topical(c) products are available delivering ivermectin at 200 to 500 micrograms/kg. Efficacy extends to nematodes of the gastrointestinal and respiratory tracts, conjunctival sac and soft tissues. Among the arthropod parasites claims have been established for the biting fly Haematobia irritans(c), the screw-worm Chrysomyia bezziana(c), larvae of the oestrid flies Hypoderma spp.(c), Dermatobia hominis(c), Oestrus ovis(s) and Gastrophilus spp.(h), lice(c,p), mange mites(c,s,p) and the ticks Boophilus spp.(c) and Ornithodorus savignyi(c). In the dog two oral formulations are available for the prevention of heartworm disease caused by Dirofilaria immitis by administration of 6 micrograms/kg once monthly during the mosquito season.</p>","PeriodicalId":7108,"journal":{"name":"Acta Leidensia","volume":"59 1-2","pages":"211-6"},"PeriodicalIF":0.0,"publicationDate":"1990-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"13351262","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Computer simulation of the long term effects of vector control and drug treatment regimes on onchocerciasis in a village community in Sierra Leone.","authors":"J B Davies","doi":"","DOIUrl":"","url":null,"abstract":"","PeriodicalId":7108,"journal":{"name":"Acta Leidensia","volume":"59 1-2","pages":"231-3"},"PeriodicalIF":0.0,"publicationDate":"1990-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"13526060","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Cost-benefits of onchocerciasis control.","authors":"B Benton, E D Skinner","doi":"","DOIUrl":"","url":null,"abstract":"","PeriodicalId":7108,"journal":{"name":"Acta Leidensia","volume":"59 1-2","pages":"405-11"},"PeriodicalIF":0.0,"publicationDate":"1990-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"13270557","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"The effect of ivermectin on the uptake and development of O. volvulus microfilariae in S. damnosum s.l.","authors":"D C Chavasse, J B Davies","doi":"","DOIUrl":"","url":null,"abstract":"","PeriodicalId":7108,"journal":{"name":"Acta Leidensia","volume":"59 1-2","pages":"227-30"},"PeriodicalIF":0.0,"publicationDate":"1990-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"13351264","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Ivermectin--clinical trials and treatment schedules in onchocerciasis.","authors":"K R Brown, D C Neu","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>Initial clinical trials with ivermectin were performed in patients with both roundworm infestation and onchocerciasis. Obvious clinical safety allowed for rapid progression through 5-30-50-100-150-200 mcg/kg in infected patients. Initial studies showed some effect at 50 mcg/kg; subsequent double-blind controlled studies, either with placebo or diethylcarbamazine (DEC), confirmed the efficacy of ivermectin as well as further defining its safety profile. Absence of adverse eye findings or serious systemic reactions justified the further open trials. Studies of patients treated at 6, 12, or 18 month intervals showed a long lasting effect of ivermectin in reducing skin microfilaria counts. Phase III studies confirmed safety and efficacy and further refined the dose to 150 mcg/kg every 12 months. Large trials in Liberia and other countries in West Africa, and subsequently under Onchocerciasis Control Program (OCP), included approximately 120,000 persons carefully followed during which few patients with serious adverse experiences were reported. These extensive field trials confirmed the relative safety allowing for broad distribution of ivermectin in programs not able to provide physician monitoring.</p>","PeriodicalId":7108,"journal":{"name":"Acta Leidensia","volume":"59 1-2","pages":"169-75"},"PeriodicalIF":0.0,"publicationDate":"1990-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"13351363","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}