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Experimental Parasitology Sep 2000
Topics: Animals; Bulinus; Child; DNA, Helminth; Female; Genetic Variation; Genetics, Population; Humans; Male; Phylogeny; Random Amplified Polymorphic DNA Technique; Schistosoma haematobium; Schistosomiasis haematobia; Zimbabwe
PubMed: 11038320
DOI: 10.1006/expr.2000.4548 -
Diagnostic Cytopathology May 2016
Topics: Animals; Female; Humans; Middle Aged; Schistosoma haematobium; Schistosomiasis haematobia; Urinary Bladder
PubMed: 26972707
DOI: 10.1002/dc.23464 -
Diagnostic Cytopathology Oct 2007
Topics: Adult; Animals; Female; Humans; Microtomy; Schistosoma haematobium; Schistosomiasis haematobia; Urine
PubMed: 17854081
DOI: 10.1002/dc.20694 -
Journal of Helminthology Sep 1975
Topics: Animals; Biomphalaria; Bulinus; Cricetinae; Dose-Response Relationship, Radiation; Larva; Liver; Lung; Mice; Radiation Effects; Schistosoma haematobium; Schistosoma mansoni; Skin; Ultraviolet Rays
PubMed: 1184943
DOI: 10.1017/s0022149x00023579 -
Parasitology Sep 2003Schistosoma haematobium and S. intercalatum readily hybridize with each other producing generations of viable hybrid offspring. Experiments were designed to investigate...
Schistosoma haematobium and S. intercalatum readily hybridize with each other producing generations of viable hybrid offspring. Experiments were designed to investigate the infectivity and viability of the S. haematobium x S. intercalatum F1 and F2 hybrid larvae in their two intermediate snail hosts compared with the parental species. Analysis of the data obtained suggested that the S. haematobium male x S. intercalatum female F1 hybrid miracidia were more infective to Bulinus truncatus than to B.forskalii, and also more infective to B. truncatus compared with the parental S. haematobium miracidia. This hybrid was also observed to have a greater cercarial productivity from both intermediate hosts and these cercariae were shown to be more infectious and to have a longer longevity compared with the cercariae of S. haematobium, S. intercalatum and the S. haematobium female x S. intercalatum male F1 hybrid cercariae. The S. haematobium female x S. intercalatum male F1 hybrid was shown not to be very successful in all stages of the investigations. The results indicate that the S. haematobium male x S. intercalatum female F1 hybrid may have many reproductive advantages over the reciprocal hybrid and the parental schistosome species. The significance of the results is discussed in relation to the epidemiological consequences occurring in Loum, Cameroon, and other areas where S. haematobium and S. intercalatum are sympatric and able to hybridize.
Topics: Animals; Bulinus; Cricetinae; Crosses, Genetic; Disease Vectors; Ecosystem; Female; Hybrid Vigor; Male; Schistosoma haematobium; Schistosomiasis
PubMed: 12964826
DOI: 10.1017/s0031182003003597 -
PLoS Neglected Tropical Diseases Apr 2010Chronic Schistosoma infection is often characterized by a state of T cell hyporesponsiveness of the host. Suppression of dendritic cell (DC) function could be one of the...
Chronic Schistosoma infection is often characterized by a state of T cell hyporesponsiveness of the host. Suppression of dendritic cell (DC) function could be one of the mechanisms underlying this phenomenon, since Schistosoma antigens are potent modulators of dendritic cell function in vitro. Yet, it remains to be established whether DC function is modulated during chronic human Schistosoma infection in vivo. To address this question, the effect of Schistosoma haematobium infection on the function of human blood DC was evaluated. We found that plasmacytoid (pDC) and myeloid DC (mDC) from infected subjects were present at lower frequencies in peripheral blood and that mDC displayed lower expression levels of HLA-DR compared to those from uninfected individuals. Furthermore, mDC from infected subjects, but not pDC, were found to have a reduced capacity to respond to TLR ligands, as determined by MAPK signaling, cytokine production and expression of maturation markers. Moreover, the T cell activating capacity of TLR-matured mDC from infected subjects was lower, likely as a result of reduced HLA-DR expression. Collectively these data show that S. haematobium infection is associated with functional impairment of human DC function in vivo and provide new insights into the underlying mechanisms of T cell hyporesponsiveness during chronic schistosomiasis.
Topics: Adolescent; Adult; Animals; Cytokines; Dendritic Cells; Female; Gene Expression; HLA-DR Antigens; Humans; Immune Tolerance; Leukocyte Count; Male; Schistosoma haematobium; Schistosomiasis haematobia; Signal Transduction; Young Adult
PubMed: 20422029
DOI: 10.1371/journal.pntd.0000667 -
The American Journal of Tropical... Sep 2014Simple, efficient, and cost-effective strategies are needed for urine sample preparation in the field diagnosis of infection with Schistosoma haematobium. In this...
Simple, efficient, and cost-effective strategies are needed for urine sample preparation in the field diagnosis of infection with Schistosoma haematobium. In this proof-of-concept study, we evaluated inexpensive and widely available paper products (paper towels, school workbook paper, and newspaper) to gravity-filter urine containing 60 eggs/mL of Schistosoma haematobium. Eggs were reliably visualized by light microscopy by using single-ply paper towels as urine filters. This filtration method has broad applicability in clinical and public health settings in resource-constrained environments.
Topics: Animals; Cost-Benefit Analysis; Filtration; Humans; Microscopy; Paper; Parasite Egg Count; Schistosoma haematobium; Schistosomiasis haematobia
PubMed: 24980496
DOI: 10.4269/ajtmh.14-0221 -
Parasitology Research Nov 2013Up to date, schistosomiasis is still prevalent worldwide. It is estimated that more than 200 million individuals are infected, and 120 million suffer from clinical... (Review)
Review
Up to date, schistosomiasis is still prevalent worldwide. It is estimated that more than 200 million individuals are infected, and 120 million suffer from clinical morbidity. Facing such huge cases of schistosomiasis, only heavy reliance on a single praziquantel for schistosomiasis control does not adapt and may promote the selection and spread of drug-resistant parasites. Therefore, it is an urgent need to develop the new antischistosomal drug. In 2008-2009, the antimalarial drug mefloquine, an arylaminoalcohol compound, has been found to be effective against schistosomes. According to the experimental studies, the deepest impression on the antischistosomal properties of mefloquine can be summarized as following points: (1) single dose of mefloquine possesses potential effect against three major species of schistosomes (Schistosoma mansoni, Schistosoma haematobium, and Schistosoma japonicum) infecting humans; (2) the drug displays similar effects against developing stages of juvenile and adult schistosomes, which are superior to that of artemisinins and praziquantel; (3) in vitro mefloquine exerts direct killing effect on juvenile and adult schistosomes, while in vivo, the efficacy of the drug is independent to host immune response, (4) mefloquine causes extensive and severe morphological, histopathological, and ultrastructural damage to adult and juvenile schistosomes, particularly, the worm tegument, musculature, gut, and vitelline glands of female worms are the key sites attacked by the drug; (5) combined treatment with mefloquine and praziquantel, or artemisinins shows synergistic effect against schistosome in experimental therapy,while in initially clinical trial, mefloquine in combination with artesunate also exhibits higher cure rates against schistosomiasis hematobia and schistosomiasis mansoni, and (6) several mefloquine-related arylmethanols exhibit potential effect against schistosomes in vivo, which is a useful clue helpful for development of new antischistosomal compound. In the present review, we have summarized the major results published in recent years, and the significance as well as the prospect for the future study of mefloquine have been discussed briefly.
Topics: Animals; Anthelmintics; Drug Synergism; Humans; Mefloquine; Schistosoma haematobium; Schistosoma japonicum; Schistosoma mansoni
PubMed: 23979493
DOI: 10.1007/s00436-013-3559-0 -
Parasitology Research Feb 2003Schistosoma haematobium and S. intercalatum belong to the S. haematobium group of schistosomes and can hybridize in nature where they are sympatric. They are therefore...
Schistosoma haematobium and S. intercalatum belong to the S. haematobium group of schistosomes and can hybridize in nature where they are sympatric. They are therefore able to co-infect the same human host. Hybridization and competitive mating interactions with S. haematobium have been implicated in restricting the distribution of S. intercalatum in Africa and in the remarkably rapid replacement of S. intercalatum by S. haematobium at Loum, Cameroon. Previous studies have demonstrated the greater pairing ability of S. haematobium over S. intercalatum in hamsters infected with both species simultaneously or infected first with S. intercalatum (Lower Guinea strain) and later with S. haematobium. The present study demonstrates the greater pairing ability of S. haematobiumover S. intercalatum in hamsters infected first with S. intercalatum (Lower Guinea) and later with S. haematobium, and indicates that S. intercalatumis unlikely to spread to areas where S. haematobium is already established.
Topics: Animals; Competitive Behavior; Cricetinae; Female; Guinea; Hybridization, Genetic; Male; Schistosoma; Schistosoma haematobium; Sex Ratio; Sexual Behavior, Animal; Time Factors
PubMed: 12541068
DOI: 10.1007/s00436-002-0747-8 -
Acta Tropica Nov 2013To shed light on the genetic diversity of Schistosoma haematobium on Zanzibar a DNA barcoding study was performed on parasite material isolated from different...
To shed light on the genetic diversity of Schistosoma haematobium on Zanzibar a DNA barcoding study was performed on parasite material isolated from different time-points 4 years apart. Substantive sequence variation was found within the mitochondrial cytochrome oxidase subunit I (cox1) and the NADH-dehydrogenase subunit 1 (nad1) with 27 and 22 unique haplotypes identified respectively and 38 when both gene regions were considered. Upon phylogenetic analysis and comparison with other S. haematobium isolates, haplotypes or barcode types partitioned into two discrete major groups, designated Group 1 and Group 2. Whilst Group 1 isolates were recovered from both Zanzibar and the African mainland, Group 2 isolates were exclusive to Zanzibar. A mixture of Group 1 and 2 parasites were recovered from individual children with no child shedding parasites of a single group haplotype alone. Whilst changes in general levels of genetic diversity between the two parasite isolation time-points were observed, no obvious change in genetic diversity was detected, despite large-scale drug distribution of praziquantel during the intervening period and there was no biased of Group 1 or 2 parasites persisting at the different time-points. To assist in future genetic screening of schistosome larval stages e.g. eggs, miracidia or cercariae, two new DNA-typing assays based on group-specific PCR primers and SNaPshotâ„¢ probes have been developed to distinguish Group 1 and 2 haplotypes.
Topics: Adolescent; Animals; Child; Cluster Analysis; DNA Barcoding, Taxonomic; Electron Transport Complex IV; Female; Genetic Variation; Genotype; Haplotypes; Humans; Male; Molecular Epidemiology; Molecular Sequence Data; Molecular Typing; NADH Dehydrogenase; Parasitology; Phylogeny; Schistosoma haematobium; Schistosomiasis haematobia; Sequence Analysis, DNA; Tanzania
PubMed: 22721826
DOI: 10.1016/j.actatropica.2012.06.002