Abstract：
:Procyclic Trypanosoma brucei brucei strain 366D is susceptible to DL-alpha-difluoromethylornithine (DFMO) with an in vitro ED50 value of 225 microM. A mutant of the procyclic strain resistant to 20 mM of DFMO was isolated by serial in vitro passages of the organisms in increasing concentrations of the drug. Drug resistance remains unchanged after at least ten serial passages in the absence of DFMO. The mutant contains the same level of ornithine decarboxylase activity as the wild-type procyclic, and the mutant enzyme exhibits a similar susceptibility toward DFMO as the wild type. Neither the rate of decarboxylation of ornithine, nor the membrane potential in the mutant cell is changed. The only observed change in the mutant is its significantly decreased uptake of DFMO which reaches a saturating level of 18 microM inside the cells; a concentration seven times below the Ki value of DFMO on T. brucei ornithine decarboxylase (130 microM). Apparently, the failure of DFMO uptake in the mutant strain has provided the basis of drug resistance. The results also raise the question on whether the uptake of DFMO by T. brucei is by passive diffusion or by transporter(s) mediation. DFMO does not compete with the uptake of ornithine, arginine or putrescine, and the reverse holds also true. However, the mutant strain cultivated under DFMO for several generations has a greatly enhanced uptake of ornithine and a moderately heightened uptake of putrescine. Both are reduced to the normal level upon further propagations of the mutant strain in the absence of DFMO.
journal_name
Mol Biochem Parasitoljournal_title
Molecular and biochemical parasitologyauthors
Phillips MA,Wang CCdoi
10.1016/0166-6851(87)90064-8subject
Has Abstractpub_date
1987-01-02 00:00:00pages
9-17issue
1eissn
0166-6851issn
1872-9428pii
0166-6851(87)90064-8journal_volume
22pub_type
杂志文章abstract：:Peptidomimetic inhibitors of mammalian zinc metalloproteases have been tested as potential agents for intervention in disease caused by kinetoplastid protozoa. Certain metalloprotease inhibitors were able to inhibit the release of variant surface glycoprotein from cultured transgenic procyclic Trypanosoma brucei, conf...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/s0166-6851(01)00244-4
更新日期：2001-04-25 00:00:00
abstract：:Plasmodium falciparum trophozoites were isolated by mechanical rupture of infected human erythrocytes followed by a series of differential centrifugation steps. After lysis with sonication, the 100 000 x g supernatant of parasites and uninfected host cells was used to determine the specific activities of a number of e...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/0166-6851(82)90035-4
更新日期：1982-05-01 00:00:00
abstract：:Protozoan parasites of the genus Leishmania have a digenetic lifecycle, alternating between the promastigote and amastigote stages. The extracellular promastigote resides within a sandfly vector, while the obligate intracellular amastigote stage replicates in the phagolysosome of mammalian host macrophages. Adaptation...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/j.molbiopara.2007.02.010
更新日期：2007-06-01 00:00:00
abstract：:Blood-stage malaria vaccine candidates include surface proteins of the merozoite. Antibodies to these proteins may either block essential steps during invasion or render the merozoite susceptible to phagocytosis or complement-mediated degradation. Structural information on merozoite surface proteins complexed to antib...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/j.molbiopara.2004.05.008
更新日期：2004-09-01 00:00:00
abstract：:The membrane potential and pH gradient over the plasma membrane of the protozoan parasite Trypanosoma brucei were measured with radioactive indicators in combination with the silicone oil centrifugation technique over a range of temperatures. At 37 degrees C a small membrane potential and pH gradient of similar magnit...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/0166-6851(92)90123-2
更新日期：1992-10-01 00:00:00
abstract：:Schistosomiasis remains a largely neglected, global health problem. The morbid pathology of the disease stems from the host's inflammatory response to parasite eggs trapped in host tissues. Long term host/parasite survival is dependent upon the successful modulation of the acute pathological response, which is induced...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/j.molbiopara.2007.06.002
更新日期：2007-10-01 00:00:00
abstract：:The intra-species polymorphism of E. histolytica and E. dispar species in endemic area is an important tool for geographic distribution and spread mechanism studies. Since E. dispar and E. histolytica shears ecological niche, cell cycle, and transmission mechanism for human host, we studied the intra-specie variation ...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/j.molbiopara.2005.02.010
更新日期：2005-06-01 00:00:00
abstract：:Some restriction fragments of kinetoplast minicircles from several trypanosomatid species (Leishmania tarentolae, Trypanosoma brucei, T. equiperdum, Herpetomonas muscarum, Crithidia fasciculata, but not T. cruzi) migrate anomalously on polyacrylamide gels. This behavior is probably due to a natural curvature of the he...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/0166-6851(84)90084-7
更新日期：1984-07-01 00:00:00
abstract：:Pathogens of the Leishmania and Trypanosoma genera compartmentalize glycolytic and other nutritional pathways in glycosomes, unique subcellular organelles related to the peroxisomes of mammals and yeasts. Most glycosomal proteins are targeted to the glycosomes by a COOH-terminal tripeptide signal similar to the peroxi...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/s0166-6851(02)00164-0
更新日期：2002-09-01 00:00:00
abstract：:Transcriptional control of the hgl5 gene of Entamoeba histolytica is mediated through an unusual core promoter composed of TATA, GAAC and Initiator elements. In the hgl5 promoter the GAAC element (AATGAACT) determines the site and rate of transcription initiation. Here we tested the role of the GAAC element in transcr...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/s0166-6851(01)00441-8
更新日期：2002-03-01 00:00:00
abstract：:ATP-binding cassette transporters (ABC transporters) are essential components of normal cellular physiological machinery in all eukaryotic and prokaryotic species, including parasites. Some ABC transporters, e.g., P-glycoproteins, are involved in the efflux of toxins and xenobiotics from the cell. At present, nothing ...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/j.molbiopara.2017.07.001
更新日期：2017-09-01 00:00:00
abstract：:After a single intravenous injection of suramin the rate of removal of the drug from the plasma into other tissue compartments of the rat is independent of initial concentration. The data can be fitted to the sum of two exponential functions, consistent with a two-compartment, open model system. Trypanosomes take up o...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/0166-6851(80)90050-x
更新日期：1980-10-01 00:00:00
abstract：:Many of the currently available nematicides used in nematode control are hazardous to the user, environment and beneficial non-target organisms. Therefore the need to develop alternative methods for nematode control such as the development of nematode-resistant crops through RNA-mediated interference (RNAi) holds grea...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/j.molbiopara.2012.09.009
更新日期：2012-11-01 00:00:00
abstract：:Adult males and females of the dog heartworm, Dirofilaria immitis, were extracted separately and, following separation of the free and conjugated ecdysteroid fractions, the conjugates were hydrolysed enzymically. Both the ecdysteroids released by hydrolysis of the conjugates and the free hormones were further purified...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/0166-6851(83)90098-1
更新日期：1983-11-01 00:00:00
abstract：:The steady-state level of the hsp70 mRNAs of Trypanosoma cruzi cultured at different temperatures and growth conditions has been analyzed by Northern blotting. We show that only one size class of hsp70 mRNA, of about 2.2 kb, is transcribed from the hsp70 cluster and that its transcription is constitutive at 28 degrees...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/0166-6851(92)90022-c
更新日期：1992-07-01 00:00:00
abstract：:The glycosylphosphatidylinositol (GPI)-anchored variant surface glycoprotein (VSG) of Trypanosoma brucei is the most abundant GPI-anchored protein expressed on any cell, and is an essential virulence factor. To determine what structural features affect efficient expression of VSG, we made a series of mutations in two ...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/s0166-6851(03)00055-0
更新日期：2003-05-01 00:00:00
abstract：:Root-knot nematodes (Meloidogyne spp.) are among the most important plant pathogens. In this study, the mitochondrial (mt) genomes of the root-knot nematodes, M. chitwoodi and M. incognita were sequenced. PCR analyses suggest that both mt genomes are circular, with an estimated size of 19.7 and 18.6-19.1kb, respective...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/j.molbiopara.2014.04.003
更新日期：2014-03-01 00:00:00
abstract：:The surface of the erythrocyte undergoes a number of modifications during infection by Plasmodium falciparum. These modifications are critical for pathogenesis of severe disease and the acquisition of host immunity through their role in interactions between the host and the parasite and in antigenic variation. Our kno...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章,评审
doi：10.1016/s0166-6851(01)00275-4
更新日期：2001-07-01 00:00:00
abstract：:We have isolated and characterized a gene encoding a novel GTP-binding protein of the GTPase superfamily in the filarial parasites Brugia malayi and Onchocerca volvulus. The deduced amino acid sequence of the cloned molecule has approximately 30% overall homology to ras proteins and approximately 90% homology to the '...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/0166-6851(92)90175-j
更新日期：1992-12-01 00:00:00
abstract：:Hookworm disease is a debilitating worm infection that affects hundreds of millions of people. Despite the existence of anthelmintic drugs, reports have testified of a decrease in efficacy of these drugs. Therefore, it is imperative to find new drugs and drug targets for hookworm disease treatment. In this study we id...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/j.molbiopara.2013.07.003
更新日期：2013-09-01 00:00:00
abstract：:The function of the ecdysone receptor (EcR) during development and molting has been thoroughly investigated in some arthropods such as insects but rarely in crustacean copepods such as the salmon louse Lepeophtheirus salmonis (L. salmonis) (Copepoda, Caligidae). The salmon louse is an ectoparasite on Atlantic salmon t...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/j.molbiopara.2016.06.007
更新日期：2016-08-01 00:00:00
abstract：:Both the alpha- and beta-tubulin genes of Leishmania enriettii are encoded by mRNA of 2.0-2.2 kb in length. We have shown previously that the alpha- and beta-tubulin genes are arranged in separate, tandem repeats of 2 and 4 kb, respectively, and now report the mapping of mature mRNA onto these cloned genes. Here we sh...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/0166-6851(85)90029-5
更新日期：1985-04-01 00:00:00
abstract：:Plasmodium falciparum is the causative organism for the most severe form of malaria among humans. The clinical symptoms are accredited to the asexual stage of parasite life cycle, involving merozoite invasion of erythrocyte, development and re-invasion into the new erythrocyte. Interaction of parasite proteins present...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/j.molbiopara.2015.09.004
更新日期：2015-08-01 00:00:00
abstract：:Given the growing appreciation of serious health sequelae from widespread Trichomonas vaginalis infection, new tools are needed to study the parasite's genetic diversity. To this end we have identified and characterized a panel of 21 microsatellites and six single-copy genes from the T. vaginalis genome, using seven l...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/j.molbiopara.2010.08.006
更新日期：2011-01-01 00:00:00
abstract：:In Leishmania mexicana two genes were detected coding for different isoforms of the glycolytic enzyme phosphoglycerate kinase. This situation contrasts with that observed in other Trypanosomatidae (Trypanosoma brucei, Trypanosoma congolense, Crithidia fasciculata) analyzed previously, which all contain three different...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/s0166-6851(97)00152-7
更新日期：1997-12-01 00:00:00
abstract：:Phosphatidylcholine (PC) and phosphatidylethanolamine (PE) are the main membrane phospholipids (PLs) of Plasmodium parasites and can be generated by the de novo (Kennedy) CDP-choline and CDP-ethanolamine pathways and by the CDP-diacylglycerol dependent pathway. The Kennedy pathways initiate from exogenous choline and ...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/j.molbiopara.2010.05.006
更新日期：2010-10-01 00:00:00
abstract：:Human infections from Plasmodium knowlesi present challenges to malaria control in Southeast Asia. P. knowlesi also offers a model for other human malaria species including Plasmodium vivax. P. knowlesi parasites can be cultivated in the laboratory, and their transformation is standardly performed by direct electropor...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/j.molbiopara.2017.10.001
更新日期：2017-12-01 00:00:00
abstract：:Asexual intraerythrocytic Plasmodium falciparum were shown to have a single isoenzyme of malate dehydrogenase. This malate dehydrogenase was purified to apparent homogeneity using a three-step purification protocol. The parasite malate dehydrogenase had an apparent subunit molecular weight of 32 kDa, a pH optimum of 7...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/0166-6851(92)90240-k
更新日期：1992-01-01 00:00:00
abstract：:Electron paramagnetic resonance spectrometry (EPR) techniques revealed a complex set of redox components in intact respiring cells of Tritrichomonas foetus, an aerotolerant anaerobic protozoon which lacks mitochondria. One of the two main systems of terminal respiration of this organism is the hydrogenosomal system, w...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/0166-6851(80)90047-x
更新日期：1980-10-01 00:00:00
abstract：:The separation by chromatofocusing of two distinct purine nucleoside cleaving activities from crude extracts of Trypanosoma brucei brucei is described. One catalyzes the reversible phosphorolysis of 5'-deoxy-5'-methylthioadenosine (MeSAdo) and adenosine (Ado) and was designated an MeSAdo/Ado phosphorylase, while the o...
journal_title：Molecular and biochemical parasitology
pub_type： 杂志文章
doi：10.1016/0166-6851(88)90030-8
更新日期：1988-01-15 00:00:00
