Abstract：
:Giardia lamblia undergo surface antigenic variation in vitro and in vivo. The presence of variant trophozoites can be detected in clones after exposure to cytotoxic monoclonal antibodies. Surviving Giardia (progeny) no longer possess the initial major surface antigen which is replaced by new antigens. Exposure of a clone from one progeny to another cytotoxic mAb specific to one newly appearing surface antigen resulted in the loss of this antigen and replacement by another set of antigens. The frequency of change was rapid (1:100-1:1000) and was dependent upon the isolate. The presence of variant populations in clones was confirmed by direct and indirect immunofluorescence using mAbs to major surface antigens of subsequent progeny. The putative amino acid sequence of a portion of one antigen revealed a cysteine-rich composition which was confirmed in this variant protein as well as others by preferential uptake of [35S]cysteine. The mechanism(s) responsible most likely involves genomic rearrangements since Southern blots revealed a family of related genes which changed frequently compared to other areas of the genome. However, expression-linked copies have not been detected. Loss and gain of surface antigens have also been found in gerbils and humans infected with defined clones, but there does not appear to be cyclical appearance of variant populations. The biological importance of antigenic variation is not known but it may contribute to chronic and/or repeated infections.
journal_name
Exp Parasitoljournal_title
Experimental parasitologyauthors
Nash TEdoi
10.1016/0014-4894(89)90104-5subject
Has Abstractpub_date
1989-02-01 00:00:00pages
238-41issue
2eissn
0014-4894issn
1090-2449pii
0014-4894(89)90104-5journal_volume
68pub_type
杂志文章,评审abstract：:Susceptible A/J and more resistant C57BL/6J mice were infected with Plasmodium chabaudi chabaudi 54X, P.c. chabaudi AS and Plasmodium chabaudi adami 408XZ. As expected, most C57BL/6J mice survived the infections with the different isolates. But in contrast to previous observations, not all A/J mice succumbed to infect...
journal_title：Experimental parasitology
pub_type： 杂志文章
doi：10.1016/j.exppara.2004.07.011
更新日期：2004-11-01 00:00:00
abstract：:Toxoplasmosis is a widely distributed disease caused by the protozoan Toxoplasma gondii that is mainly transmitted orally. Once ingested, the parasite crosses the intestinal barrier to reach the blood and lymph systems to migrate to other regions of the host. The objective of this study was to evaluate the changes in ...
journal_title：Experimental parasitology
pub_type： 杂志文章
doi：10.1016/j.exppara.2015.05.007
更新日期：2015-09-01 00:00:00
abstract：:High-throughput drug screening methods against the intracellular stage of Leishmania have been facilitated by the development of in vitro models of infection. The use of cell lines rather than primary cells facilitates these methods. Peripheral blood mononuclear cell (PBMC) derived macrophages and THP-1 cells were inf...
journal_title：Experimental parasitology
pub_type： 杂志文章
doi：10.1016/j.exppara.2010.06.007
更新日期：2010-12-01 00:00:00
abstract：:Indirect immunocytochemistry, in conjunction with confocal scanning laser microscopy and electron-microscopic immunogold labeling, has been used to localize neuropeptide and 5-hydroxytryptamine (5-HT) immunoreactivities (IRs) in the plerocercoid (scolex and surrounding blastocyst) of the trypanorhynch tapeworm, Grillo...
journal_title：Experimental parasitology
pub_type： 杂志文章
doi：10.1006/expr.1994.1103
更新日期：1994-11-01 00:00:00
abstract：:Trypanosomatid protozoa lack consensus promoters for RNA polymerase (RNAP) II. However, the artificial insertion of the T7 promoter (P(T7)) and the tetracycline repressor into Trypanosoma brucei cell lines expressing T7RNAP allows P(T7)-driven gene expression to be tetracycline-inducible. These cell lines provide a mo...
journal_title：Experimental parasitology
pub_type： 杂志文章
doi：10.1016/j.exppara.2007.01.001
更新日期：2007-07-01 00:00:00
abstract：:About 200 clinically used amphiphilic cationic drugs have been shown to be active in vitro against Trypanosoma cruzi at concentrations of less than or equal to 1 mM. Activity against epimastigote and trypomastigote forms was similar, and in both cases the most potent drugs were litracene, maprotiline, thioproperazine,...
journal_title：Experimental parasitology
pub_type： 杂志文章
doi：10.1016/s0014-4894(85)80020-5
更新日期：1985-08-01 00:00:00
abstract：:Cutaneous Leishmaniasis (CL) caused by Leishmania aethiopica is a public health and social problem with a sequel of severe and mutilating skin lesions. It is manifested in three forms: localized CL (LCL), mucosal CL (MCL) and diffuse CL (DCL). Unresponsiveness to sodium stibogluconate (Sb(V)) is common in Ethiopian CL...
journal_title：Experimental parasitology
pub_type： 杂志文章
doi：10.1016/j.exppara.2013.01.022
更新日期：2013-05-01 00:00:00
abstract：:A total of 597 faecal samples were collected from western grey kangaroos (Macropus fuliginosus), Euros (M. robustus), red kangaroos (M. rufus) in Western Australia and Eastern Grey Kangaroos (M. giganteus) from Victoria and screened for the presence of Eimeria by PCR at the 18S ribosomal RNA (rRNA) locus. The overall ...
journal_title：Experimental parasitology
pub_type： 杂志文章
doi：10.1016/j.exppara.2012.07.003
更新日期：2012-10-01 00:00:00
abstract：:Polymerase chain reaction amplification of several polymorphic genes has been used to study the population biology of Plasmodium falciparum. S antigen is particularly suitable for such studies, but difficulties in the amplification of this gene have precluded its use. Here we describe a simple method for the amplifica...
journal_title：Experimental parasitology
pub_type： 杂志文章
doi：10.1006/expr.1993.1108
更新日期：1993-12-01 00:00:00
abstract：:African trypanosomes exhibit dramatic developmental changes in carbohydrate and energy metabolism, with cytochrome-mediated respiration playing an important role only in the insect stages. The parasites possess three isozymes of malate dehydrogenase, each of which has a different subcellular localization and, likely, ...
journal_title：Experimental parasitology
pub_type： 杂志文章
doi：10.1006/expr.1998.4260
更新日期：1998-05-01 00:00:00
abstract：:The aim of this study was to observe the intestinal mucosal/systemic responses triggered by intranasal vaccination using recombinant Trichinella spiralis serine protease (rTsSP) and its capacity to elicit immune protection against larva challenge in a murine model. rTsSP coupled with cholera toxin B subunit (CTB) was ...
journal_title：Experimental parasitology
pub_type： 杂志文章
doi：10.1016/j.exppara.2019.04.006
更新日期：2019-06-01 00:00:00
abstract：:One- and two-dimensional gel electrophoresis of the solubilized mitochondrial proteins of bloodstream and procyclic trypomastigote Trypanosoma brucei rhodesiense and radiolabeling of proteins in the presence of cycloheximide were used to identify proteins synthesized in the trypanosome mitochondrion. The proteins whic...
journal_title：Experimental parasitology
pub_type： 杂志文章
doi：10.1016/0014-4894(86)90011-1
更新日期：1986-08-01 00:00:00
abstract：:Two strains of mice which share identical H-2 genes but differ in their genetic backgrounds were compared for their ability to resist infection with Trichinella spiralis. The two strains of mice, C3HeB/FeJ and AKR/J, share the H-2k haplotype which is associated with susceptibility to primary infection with T. spiralis...
journal_title：Experimental parasitology
pub_type： 杂志文章
doi：10.1016/0014-4894(83)90009-7
更新日期：1983-04-01 00:00:00
abstract：:Leishmaniasis are globally widespread parasitic diseases which often leads to death if left untreated. Currently available drugs present different drawbacks, so there is an urgent need to develop new, safe and cost-effective drugs against leishmaniasis. In this study we tested a small library of trans-stilbene and ter...
journal_title：Experimental parasitology
pub_type： 杂志文章
doi：10.1016/j.exppara.2016.03.007
更新日期：2016-07-01 00:00:00
abstract：:Three membrane thermotropic transitions at 8, 20, and 40 degrees C have been detected in human red blood cells (RBC) by using spin-labeled stearic acids. Red blood cells infected in vitro by Plasmodium falciparum showed the disappearance of the 8 degrees C transition and a lowering of the 40 degrees C transition to 32...
journal_title：Experimental parasitology
pub_type： 杂志文章
doi：10.1016/0014-4894(89)90073-8
更新日期：1989-10-01 00:00:00
abstract：:Plasma butyrylcholinesterase (BChE) hydrolyzes ester-containing compounds such as succinylcholine, as well as acting as a scavenger against neurotoxic organophosphates (OPs). We previously found that Nippostrongylus brasiliensis infection makes rats more susceptible to OP toxicity by decreasing serum paraoxonase-1 (PO...
journal_title：Experimental parasitology
pub_type： 杂志文章
doi：10.1016/j.exppara.2009.02.009
更新日期：2009-06-01 00:00:00
abstract：:With the aim of determining selectivity and the possible target(s) of nitroheteroaryl-1,3,4-thiadiazoles considered as possible leads for the development of anti-leishmanial agents, we studied 5-nitroimidazole, 5-nitrofuran and 5-nitrothiophene analogs of N-substituted-piperazinyl-1,3,4-thiadiazoles. We investigated 2...
journal_title：Experimental parasitology
pub_type： 杂志文章
doi：10.1016/j.exppara.2008.12.004
更新日期：2009-04-01 00:00:00
abstract：:In this work, an ecto-phosphatase activity of Entamoeba histolytica was characterized using intact cells. This activity presented the following biochemical characteristics: (i) it hydrolyzes p-NPP with V(max) of 8.00+/-0.22 nmol p-NP x h(-1) x 10(-5) cells and K(m) of 2.68+/-0.25 mM; (ii) it is inhibited by acid phosp...
journal_title：Experimental parasitology
pub_type： 杂志文章
doi：10.1016/j.exppara.2006.09.019
更新日期：2007-04-01 00:00:00
abstract：:Many methods have been proposed for removing contaminating host cells from mouse peritoneal exudates infected with Toxoplasma gondii tachyzoites. Of these, eight established methods were compared. They were density gradients, sonication and trypsin digestion, differential centrifugation, haemolysin digestion, filtrati...
journal_title：Experimental parasitology
pub_type： 杂志文章
doi：10.1016/0014-4894(84)90080-8
更新日期：1984-04-01 00:00:00
abstract：:The woylie or brush-tailed bettong (Bettongia penicillata) is a medium-sized native Australian marsupial that has undergone a dramatic decline in numbers in recent years. Trypanosome parasites have been identified in the woylie but little is known about the prevalence and clinical impact of other haemoprotozoan parasi...
journal_title：Experimental parasitology
pub_type： 杂志文章
doi：10.1016/j.exppara.2012.03.013
更新日期：2012-06-01 00:00:00
abstract：:A mode of action of the inducible treatment with trypsin for the development of Mesocestoides lineatus tetrathyridium to adult was analyzed by administering various agents effective on Ca2+-dependent metabolic pathways in the cells: protein kinase C activators such as a synthetic diacylglycerol, 1-oleoyl-2-acetylglyce...
journal_title：Experimental parasitology
pub_type： 杂志文章
doi：10.1016/0014-4894(86)90036-6
更新日期：1986-12-01 00:00:00
abstract：:In Trichostrongylus colubriformis-infected rabbits, epithelial cell migration rates and cell transit times along the villi were compared by radioautography on histological slides to normal values from noninfected small intestine. Regions of gut with high (upper jejunum) and low (ileum) burdens of worms were both exami...
journal_title：Experimental parasitology
pub_type： 杂志文章
doi：10.1016/0014-4894(89)90116-1
更新日期：1989-04-01 00:00:00
abstract：:A cDNA encoding elastase was isolated from Steinernema carpocapsae by suppression subtractive hybridization and rapid amplification of 5' cDNA ends. The predicted protein contained a 19-aa signal peptide, a 44-aa N-terminal propeptide, and a 264-aa mature protein with a predicted molecular mass of 28,949 Da and a theo...
journal_title：Experimental parasitology
pub_type： 杂志文章
doi：10.1016/j.exppara.2009.01.014
更新日期：2009-05-01 00:00:00
abstract：:By using a sensitive fluorometric method with Val-Leu-Gly-Arg-3-amino-9-ethylcarbazole (VLGR-AEC) as a substrate, two endopeptidase activities were identified in two fractions of Sephacryl S-200 gel filtration from soluble P. berghei and P. chabaudi extracts. Controls with normal mouse erythrocytes, with leukocytes, a...
journal_title：Experimental parasitology
pub_type： 杂志文章
doi：10.1016/0014-4894(87)90013-0
更新日期：1987-08-01 00:00:00
abstract：:Giardia duodenalis is one of the most important intestinal parasites globally, especially in children, and in Cuba is the leading cause of chronic paediatric diarrhoea in this population. G. duodenalis is composed of eight genetic groups (or assemblages), two of which (A and B) are apparently zoonotic, occurring in bo...
journal_title：Experimental parasitology
pub_type： 杂志文章
doi：10.1016/j.exppara.2019.107814
更新日期：2020-02-01 00:00:00
abstract：:Two species of glycoproteins from Leishmania braziliensis promastigotes of apparent molecular weights of 53,000 (glycoprotein 53) and 47,000 (glycoprotein 47) were localized. Four lectins with different sugar specificities bound to the blotting sheet to which the electrophoretically separated materials were transferre...
journal_title：Experimental parasitology
pub_type： 杂志文章
doi：10.1016/0014-4894(86)90188-8
更新日期：1986-06-01 00:00:00
abstract：:Toxoplasma gondii and the related Apicomplexan protozoan pathogens, Plasmodium, Cryptosporidium, and Eimeria, are obligate intracellular parasites which cause severe disease in their hosts. The recent development of transient transfection of Toxoplasma permits the development of strategies utilizing "reverse genetics"...
journal_title：Experimental parasitology
pub_type： 杂志文章
doi：10.1006/expr.1995.1006
更新日期：1995-02-01 00:00:00
abstract：:Toll-like receptors (TLRs) play a fundamental role in the rapid activation of innate immune responses to a variety of pathogen-associated molecular patterns (PAMPs). In a previous study we observed an increase in the level of expression of TLR2 and TLR4 mRNA in the jejunum and colon during experimental hymenolepidosis...
journal_title：Experimental parasitology
pub_type： 杂志文章
doi：10.1016/j.exppara.2014.07.009
更新日期：2014-10-01 00:00:00
abstract：:Cutaneous lesions elicited in guinea pigs by primary and secondary feeding populations of the argasid tick, Ornithodorus tartakovskyi, were analyzed by light and electron microscopy. Small clusters of basophils appeared at primary bite sites within 24 hr of tick attachment, and by 72 hr constituted approximately 11% o...
journal_title：Experimental parasitology
pub_type： 杂志文章
doi：10.1016/0014-4894(83)90058-9
更新日期：1983-10-01 00:00:00
abstract：:Previous studies showed that Echinococcus granulosus infection reduces allergic airway inflammation in experimentally infected hosts and the cystic fluid of E. granulosus is known to activate regulatory T (CD4+CD25+Foxp3+T, Treg) cells. To evaluate the effects of cystic fluid of E. granulosus on allergic airway inflam...
journal_title：Experimental parasitology
pub_type： 杂志文章
doi：10.1016/j.exppara.2019.02.003
更新日期：2019-03-01 00:00:00
