Abstract:
:The fine structure of the envelopes surrounding hatched and unhatched oncospheres of Hymenolepis nana has been investigated by transmission and scanning electron microscopy (SEM), together with light microscope histochemical observations of JB-4 embedded material. The oncosphere is surrounded by 3 layers--the capsule, the outer envelope and the inner envelope, the latter giving rise to the embryophore and the 'oncospheral membrane'. An additional layer--the polar filament layer--lies between the 'oncospheral membrane' and the oncosphere. Shell material is deposited on the capsule as a thin layer. It is secreted by the outer envelope, which degenerates once shell formation is complete. The uterus may also contribute to shell formation. The embryophore forms a thin incomplete and peripheral layer within the inner envelope. In the basal region of this envelope, partial development of an 'oncospheral membrane' takes place, but it does not become detached as a separate layer. The polar filaments, which are characteristic of the oncosphere of H. nana, are derived from the epithelial covering of the oncosphere itself, which delaminates to form a separate polar filament layer. The filaments arise from knob-like projections at opposite poles of this layer. The design of the embryonic envelopes in H. nana show a number of modifications from the basic cyclophyllidean pattern, and these can be related to the demands of its 'direct' life-cycle.
journal_name
Parasitologyjournal_title
Parasitologyauthors
Fairweather I,Threadgold LTdoi
10.1017/s0031182000066968subject
Has Abstractpub_date
1981-06-01 00:00:00pages
429-43issue
Pt 3eissn
0031-1820issn
1469-8161journal_volume
82pub_type
杂志文章相关文献
PARASITOLOGY文献大全abstract::The sequence of appearance of specific lytic activity against more than 20 variable antigen types (VATs) of Trypanosoma vivax in the serum of 27 animals belonging to 5 species has been examined. For each host species there was a characteristic course of infection, with differences in height and duration of parasitaemi...
journal_title:Parasitology
pub_type: 杂志文章
doi:10.1017/s0031182000063447
更新日期:1986-02-01 00:00:00
abstract::Toxoplasma gondii has a unique enzyme, a NTPase, which has a wide specificity toward NTP. In the present study, we produced a monoclonal antibody (IgG1, 6C6) against the enzyme which could recognize NTPase isozymes among several strains of T. gondii. Three avirulent strains of T. gondii, ME49, Beverley and Nakayama, w...
journal_title:Parasitology
pub_type: 杂志文章
doi:10.1017/s0031182000007101
更新日期:2001-01-01 00:00:00
abstract::Theileria-free waterbuck (Kobus defassa) born in captivity were successfully infected with Theileria parva sporozoites derived from ticks infected by feeding on African buffalo (Syncerus caffer). All waterbuck underwent mild infections with the development of sporadic schizont and piroplasm parasitosis when inoculated...
journal_title:Parasitology
pub_type: 杂志文章
doi:10.1017/s0031182000077416
更新日期:1994-06-01 00:00:00
abstract::We cloned and expressed Echinostoma caproni HSP70 in Escherichia coli. This molecule presents an open reading frame (ORF) of 655 amino acids, and a theoretical molecular weight of 71 kDa. E. caproni HSP70 protein showed a high homology to other helminth molecules, major differences being located in the C-terminal regi...
journal_title:Parasitology
pub_type: 杂志文章
doi:10.1017/S0031182008004927
更新日期:2008-10-01 00:00:00
abstract::The surface proteins and glycoproteins of red cells from Plasmodium berghei-infected blood have been radio-isotope labelled and compared with those of normal mouse erythrocytes using the following protein labelling probes: lactoperoxidase-catalysed radio-iodination of tyrosyl residues, periodate oxidation and NaB3H4 r...
journal_title:Parasitology
pub_type: 杂志文章
doi:10.1017/s0031182000056031
更新日期:1980-10-01 00:00:00
abstract::Post-mesocyclic development of Trypanosoma brucei in the tsetse fly in its migration from midgut to salivary glands, was revisited by sequential microdissection, morphometry and DNA-cytofluorometry. This development started by day 6 after the infective feed, with passage of mesocyclic midgut trypomastigotes through pr...
journal_title:Parasitology
pub_type: 杂志文章
doi:10.1017/s0031182099004217
更新日期:1999-05-01 00:00:00
abstract::Oocysts of Cryptosporidium parvum showed relatively low levels of SOD activity. The SOD which had a pI of 4.8 and an approximate molecular weight of 35 kDa appeared to be iron dependent. Catalase, glutathione transferase, glutathione reductase and glutathione peroxidase activity could not be detected, nor could trypan...
journal_title:Parasitology
pub_type: 杂志文章
doi:10.1017/s0031182096008037
更新日期:1997-01-01 00:00:00
abstract::The presence of introduced hosts can increase or decrease infections of co-introduced parasites in native species of conservation concern. In this study, we compared parasite abundance, intensity, and prevalence between native Awaous stamineus and introduced poeciliid fishes by a co-introduced nematode parasite (Camal...
journal_title:Parasitology
pub_type: 杂志文章
doi:10.1017/S0031182016001001
更新日期:2016-10-01 00:00:00
abstract::There is increasing support for the presence of viruses and virus-like particles inside protozoan cells. This study describes viral-like RNA molecules that have been detected in two species of Eimeria that infect the chicken. The RNA molecule identified in E. maxima has been characterized: subcellular fractionation st...
journal_title:Parasitology
pub_type: 杂志文章
doi:10.1017/s0031182000063198
更新日期:1990-10-01 00:00:00
abstract::The blackcap (Sylvia atricapilla) is a common Palearctic migratory warbler, and haemosporidian parasites are common in this species. However, genetic and phenotypic diversity of haemosporidians in warblers has been insufficiently investigated and poorly linked. We addressed this issue by combining molecular and micros...
journal_title:Parasitology
pub_type: 杂志文章
doi:10.1017/S0031182009991235
更新日期:2010-02-01 00:00:00
abstract::Ascarid parasites infect a variety of hosts and regular anthelmintic treatment is recommended for all species. Parascaris spp. is the only ascarid species with widespread anthelmintic resistance, which allows for the study of resistance mechanisms. The purpose of this study was to establish an in vitro drug exposure p...
journal_title:Parasitology
pub_type: 杂志文章
doi:10.1017/S0031182020000189
更新日期:2020-05-01 00:00:00
abstract::Intestinal diarrheagenic polyparasitic infections are among the major public health concerns in developing countries. Here we examined stool specimens by microscopy, DNA dot blot and polymerase chain reaction (PCR) to evaluate the co-infection of four principal protozoans among amoebic dysentery cases from Northeast I...
journal_title:Parasitology
pub_type: 杂志文章
doi:10.1017/S0031182015000669
更新日期:2015-09-01 00:00:00
abstract::Resistance to diclazuril was induced by 10 passages of the Houghton strains of Eimeria acervulina and E. tenella in chickens given progressively greater concentrations of the drug. This resistance was, however, not complete since the drug retained some efficacy against the drug-passaged lines. Attempts to passage the ...
journal_title:Parasitology
pub_type: 杂志文章
doi:10.1017/s0031182000058625
更新日期:1989-10-01 00:00:00
abstract::Digenean parasites infecting four Cominella whelk species (C. glandiformis, C. adspersa, C. maculosa and C. virgata), which inhabit New Zealand's intertidal zone, were analysed using molecular techniques. Mitochondrial 16S and cytochrome oxidase 1 (COI) and nuclear rDNA ITS1 sequences were used to infer phylogenetic r...
journal_title:Parasitology
pub_type: 杂志文章
doi:10.1017/S0031182016000494
更新日期:2016-08-01 00:00:00
abstract::We studied the pattern of infection and the inter-annual variation and individual factors affecting the infection of 2 species of nasopharyngeal bot flies, Cephenemyia auribarbis and Pharyngomyia picta (Diptera: Oestridae), in a population of Iberian red deer (Cervus elaphus hispanicus) from south central Spain (10 an...
journal_title:Parasitology
pub_type: 杂志文章
doi:10.1017/s0031182004005578
更新日期:2004-09-01 00:00:00
abstract::Conventional mice and congenitally athymic, nude mice were infected with 20 metacercariae of the intestinal trematode Echinostoma revolutum. The sequential events in the pathological changes in the intestine were studied at different intervals post-infection. By day 11 onwards the conventional mice displayed dilatatio...
journal_title:Parasitology
pub_type: 杂志文章
doi:10.1017/s0031182000054706
更新日期:1984-06-01 00:00:00
abstract::Schistosoma mansoni egg counts by faecal examination vary considerably and are not very sensitive, so prevalences are underestimated. The distribution of egg counts can adequately be described by a stochastic model which distinguishes variation in counts between persons and variation in repeated counts within a person...
journal_title:Parasitology
pub_type: 杂志文章
doi:10.1017/s0031182096008207
更新日期:1997-02-01 00:00:00
abstract::Species composition of wild reservoir hosts can influence the transmission and maintenance of multi-host vector borne pathogens. The 'pace of life' hypothesis proposes that the life history strategy of reservoir hosts can influence pathogen transmission of vector borne generalist pathogens. We use empirical data to pa...
journal_title:Parasitology
pub_type: 杂志文章
doi:10.1017/S0031182017001287
更新日期:2017-12-01 00:00:00
abstract::Most, if not all, organisms face attack by natural enemies and will be selected to evolve some form of defence. Resistance may have costs as well as its obvious benefits. These costs may be associated with actual defence or with the maintenance of the defensive machinery irrespective of whether a challenge occurs. In ...
journal_title:Parasitology
pub_type: 杂志文章,评审
doi:10.1017/s0031182002001750
更新日期:2002-01-01 00:00:00
abstract::In parallel with massive research efforts in human schistosomiasis over the past 30 years, persistent efforts have been made to understand the basis for compatibility and incompatibility in molluscan schistosomiasis. Snail plasma contains molecules that are toxic to trematodes, but these seem to kill only species that...
journal_title:Parasitology
pub_type: 杂志文章,评审
doi:10.1017/s0031182001008137
更新日期:2001-01-01 00:00:00
abstract::Eimerian oocysts were found in 98% of 422 faeces samples from goats in SE England. It was found that 74% of the samples contained thousands or tens of thousands of oocysts/g. Kids less than 1 year old had higher oocyst counts than yearling or adult goats. Nine species of Eimeria were identified, and 65% of the samples...
journal_title:Parasitology
pub_type: 杂志文章
doi:10.1017/s0031182000064052
更新日期:1986-04-01 00:00:00
abstract::The complete sequence of the 18S small subunit (SSU) ribosomal DNA of Hammondia hammondi and Sarcocystis mucosa was obtained and compared to SSU rDNA sequences of Neospora caninum, Toxoplasma gondii, Besnoitia besnoiti, 2 species of Frenkelia, 3 species of Isospora, and 13 species of Sarcocystis. Analyses showed that ...
journal_title:Parasitology
pub_type: 杂志文章
doi:10.1017/s0031182099004618
更新日期:1999-08-01 00:00:00
abstract::A number of authors have demonstrated that the schistosomicidal compound, Praziquantel (Pzq), depends for its action upon the immune status of the host (Sabah et al. 1985; Brindley & Sher, 1987; Doenhoff et al. 1987). We have attempted to define the synergistic interaction between immuno- and chemotherapy further, usi...
journal_title:Parasitology
pub_type: 杂志文章
doi:10.1017/s0031182000059497
更新日期:1991-10-01 00:00:00
abstract::The development and growth of Haemonchus contortus was studied in the stomach of the laboratory rabbit. Less than 1% of the ensheathed infective larvae given to rabbits became established, whereas after exsheathment in vitro under physiological conditions, 20-30% of the larvae administered developed to the 4th stage. ...
journal_title:Parasitology
pub_type: 杂志文章
doi:10.1017/s0031182000047867
更新日期:1977-06-01 00:00:00
abstract::Changes in the cardiac beta-adrenergic system in early stages of Trypanosoma cruzi infection have been described. Here, we studied an early (135 days post-infection-p.i.) and a late stage (365 days p.i.) of the cardiac chronic form of the experimental infection (Tulahuen or SGO-Z12 strains), determining plasma epineph...
journal_title:Parasitology
pub_type: 杂志文章
doi:10.1017/S0031182009006337
更新日期:2009-07-01 00:00:00
abstract::Analysis of the electrical properties of neurons in the motornervous system of Ascaris sutom suggests that it is largely an analogue system. The motorneurons do not conduct action potentials and they release transmitter tonically at their normal resting potential; transmitter release is increased or decreased as a con...
journal_title:Parasitology
pub_type: 杂志文章,评审
doi:10.1017/s0031182000077921
更新日期:1996-01-01 00:00:00
abstract::Described in the present study is a major component of the cell wall of 2 of the most pathogenic parasites of molluscs, Perkinsus atlanticus and P. marinus. The component is a high molecular weight protein (233 kDa), which we have named PWP-1 (for Perkinsus wall protein-1). Western blots, using a polyclonal serum gene...
journal_title:Parasitology
pub_type: 杂志文章
doi:10.1017/s0031182002001415
更新日期:2002-05-01 00:00:00
abstract::The ribosomal RNA (rRNA) gene units of Schistosoma mansoni and S. rodhaini, of the lateral spined egg group, have been studied. The schistosome rRNA gene unit consists of a regular interspersion of the two genes encoding the large and small rRNA units with two spacers. The large spacer is not transcribed while the sma...
journal_title:Parasitology
pub_type: 杂志文章
doi:10.1017/s0031182000059709
更新日期:1989-02-01 00:00:00
abstract::We assessed the distribution of Trypanosoma cruzi Discrete Typing Units (DTUs) in domestic and peridomestic Triatoma infestans and Triatoma sordida specimens collected in a well-defined rural area in Pampa del Indio, northeastern Argentina. Microscopically-positive bugs were randomly selected with a multi-level sampli...
journal_title:Parasitology
pub_type: 杂志文章
doi:10.1017/S0031182012000856
更新日期:2012-10-01 00:00:00
abstract:OBJECTIVE:Unravelling the determinants of parasite life-history traits in natural settings is complex. Here, we deciphered the relationships between biotic, abiotic factors and the variation in 4 life-history traits (body size, egg presence, egg number and egg size) in the fish ectoparasite Tracheliastes polycolpus. We...
journal_title:Parasitology
pub_type: 杂志文章
doi:10.1017/S003118201100014X
更新日期:2011-06-01 00:00:00