Showing papers in "Molecular and Biochemical Parasitology in 1982"

TL;DR: Two enzymes involved in the de novo synthesis of pyrimidines, orotic acid PRTase, and orotidine 5'-phosphate decarboxylase, were present in parasite extracts as were the enzymes for pyrimidine nucleotide phosphorylation.

TL;DR: The data indicate that T. brucei is diploid, and no sub-population of haploid cells was observed in T. Brucei grown in rats or in culture.

TL;DR: The DNA of Plasmodium falciparum has been purified and fragmented with the restriction endonucleases EcoRI and HindIII and recovered from these libraries specific clones containing repetitive DNA sequences, rRNA gene(s) and sequences homologous to an actin gene probe.

TL;DR: The DNA isolated from adults and cercariae of Schistosoma mansoni were found to be indistinguishable in all analyses and Cot analysis demonstrated that the haploid genome of S. mansoni is 0.26 pg and that it contains both moderately and highly repeated components.

TL;DR: The results suggest the beta-oxidation of fatty acids is relatively more important to Leishmania amastigote than promastigotes, whereas the reverse is true for glycolysis.

TL;DR: Preincubation of the trypomastigotes with sera from Chagasic patients elicits a 60% inhibition of the parasite interiorization into mammalian cells in culture when compared with normal human serum or anti-epimastigote serum, which suggests that the antigens specific to theTrypanosoma cruiser form are involved in the interiorization process.

TL;DR: An acid peptidase that degrades hemoglobin optimally at pH 3.5, a neutral aminopeptidase and an alkaline endopeptide that acts on an alpha-N-blocked synthetic substrate have been demonstrated in Plasmodium falciparum in culture.

TL;DR: It was shown that the synthesis of many parasite polypeptides was restricted to defined morphological stages of parasite development, and RNA synthesis was shown to increase in rate steadily during parasite growth and to fall sharply during merozoite invasion.

TL;DR: It is proposed that there is a wheat-germ agglutinin-like lectin on the T. cruzi trypomastigote surface which recognizes and attaches to an N-acetylglucosamine-containing receptor on the vertebrate cell surface prior to infection.

TL;DR: It is not possible to conclude that N-acetyl-D-glucosamine inhibits merozoite attachment and reinvasion specifically by competition for the receptor, so it is concluded that this sugar has a deleterious effect on terminal stages of parasite maturation.

TL;DR: The results indicate that PEPCK and ME are present in different subcellular compartments, a fact significant for the prevention of a futile cycle between C4-dicarboxylic acids and C3-monocarboxYlic acids, which might take place if both enzymes functioned in the same compartment.

TL;DR: The subcellular distribution of adenylate cyclase, cyclic-AMP phosphodiesterase, protein kinases and phosphoprotein phosphatase in bloodstream forms of Trypanosoma brucei was determined by isopycnic sucrose-gradient centrifugation of post-large-granule extracts.

TL;DR: Eleven proteins synthesised by the human parasite, Plasmodium falciparum labeled with various radioactive substrates, were localised on the surface of the schizont-infected erythrocyte and appeared to represent three doublets.

TL;DR: The results obtained indicate the existence in T. cruzi trypomastigotes of an active system for infecting fibroblastic cells, which is only partially expressed inTrypanosoma cruzi recently released from host fibro Blasts but which can undergo a further extracellular maturation, thus allowing studies on the mechanism of infection in cell-free media.

TL;DR: The results suggest that a 250 000 dalton glycoprotein which is synthesised only by late trophozoites or schizonts is exposed either on the surface of the infected erythrocyte, thesurface of the merozoite, or both.

TL;DR: Cell fractionation showed that the particle-bound, more acidic phospholipase A1 was associated with alpha-mannosidase- and acid proteinase-containing lysosomes, which indicated that this enzyme was more sensitive towards the inhibitory action of higher concentrations of this detergent and diisopropyl fluorophosphate.

TL;DR: A limited number of cloned lines, derived from strain NK 65 at different times during syringe transmission, shared the infectivity properties of the parent strain at the moment of cloning, thus confirming that in the infective stage single asexual parasites from the schizogonic cycle are able to originate the whole cycle.

TL;DR: The evidence presented supports the conclusion that G. lamblia trophozoites appear incapable of synthesizing pyrimidines de novo but are capable of salvaging preformed pyridines and pyrimidine nucleosides from the growth medium and the enzymes of this p Skyrimidine salvage pathway are not organelle associated.

TL;DR: Accumulated evidence suggests that many, if not all of the new antigens identified for the first time in this report are on the SI-RBC outer membrane.

TL;DR: The results obtained suggest that a parasite glycoprotein is involved in the penetration step of T. cruzi trypomastigotes into fibroblastic cells, and that adhesion, penetration, and transformation to spheromastsigotes are three different processes, each one of them requiring de novo synthesis of distinct proteins.

TL;DR: It is suggested that the sustained release of endogenous Ca2+ may affect the sequence of excitation-contraction coupling and that such interference may cause the observed massive contraction of the tapeworm's musculature.

TL;DR: The majorospholipids present in the phospholipid extract of Schistosoma Mansoni were phosphatidylcholine (28%), phosph atidylethanolamine (925%), phosphAtidylserine (15%) and phosphatodylglycerol (8%).

TL;DR: A good correlation between the Ki and in vivo activity of these analogues was observed and a competitive inhibitor of both 3-phosphoglycerate and ATP protected the Fasciola enzyme from inhibition by N-ethylmaleimide.

TL;DR: A convenient method was employed for the efficient extraction of total RNA from Plasmodium falciparum and the presence of proteins well over 200 000 molecular weight, with the majority of polypeptides having high molecular weights was revealed.

TL;DR: The results are discussed in terms of the transepithelial transport function of the surface epithelial syncytium and a Ca2+-ATPase reported previously from the OFM of S. mansoni.

TL;DR: A 48 h pretreatment of healthy erythrocytes with 5 x 10(-5) M 25-OH-D-3 did not change their susceptibility to invasion by the parasite and their ability to support the growth of P. falciparum.

TL;DR: The results reveal the induction by a primary infection of changes in brush border membrane structure and the persistence of these changes in the immune host.

TL;DR: These studies confirmed that freshly excysted juveniles have an aerobic energy metabolism, but are already fully equipped for life in the absence of oxygen.

TL;DR: Multilaminate vesicles were purified, from homogenised whole Schistosoma mansoni adults, by differential density centrifugation on sucrose gradients, following methods previously employed for isolating multilamellar bodies from mammalian lung, suggesting a more active role for schistosome MLB than that of a mere reservoir of preformed membrane precursors.

TL;DR: It is suggested that, by incorporation into cellular membranes, 0-alklglycerols affect factors responsible for the interaction of membranes and the cytoskeleton as well as enzymes of lipid metabolism.