Search results for "Nails"
showing 10 items of 109 documents
Infection success of Echinoparyphium aconiatum (Trematoda) in its snail host under high temperature: role of host resistance
2014
Background Extreme weather events such as summer heat waves become more frequent owing to global climate change and are predicted to alter disease dynamics. This is because high temperatures can reduce host immune function. Predicting the impact of climate change on host-parasite interactions is, however, difficult as temperature may also affect parasite infective stages and other host characteristics determining the outcome of interaction. Methods Two experiments were conducted to investigate these phenomena in a Lymnaea stagnalis–Echinoparyphium aconiatum (Trematoda) interaction. In the first experiment, the effects of exposure of snails to experimental heat waves [maintenance at 25°C vs.…
A new baseline for fascioliasis in Venezuela: lymnaeid vectors ascertained by DNA sequencing and analysis of their relationships with human and anima…
2011
Abstract Background Human and animal fascioliasis poses serious public health problems in South America. In Venezuela, livestock infection represents an important veterinary problem whereas there appear to be few human cases reported, most of which are passively detected in health centres. However, results of recent surveys suggest that the situation may be underestimated in particular areas. To obtain a baseline for future fascioliasis assessment, studies were undertaken by means of rDNA ITS-2 and ITS-1 and mtDNA cox 1 sequencing to clarify the specific status of Venezuelan lymnaeids, their geographical distribution and fascioliasis transmission capacity, by comparison with other American …
Cytogenetics of the land snails Cantareus aspersus and C. mazzullii (Mollusca: Gastropoda: Pulmonata).
2004
A cytogenetic study was carried out on the chromosomes and nuclear DNA contents of the land snails Cantareus aspersus and C. mazzullii (Gastropoda: Pulmonata). Chromosomes were studied using Giemsa staining, banding methods and fluorescent in situ hybridization (FISH) with three repetitive DNA probes [18S rDNA, (GATA)n and (TTAGGG)n]. Results were very similar in the two species both showing (1) 54 bi-armed chromosomes [submetacentrics (SM) C metacentrics (M) C subtelocentrics (ST)]; (2) 10 terminal NORs after sequential application of rDNA FISH and silver staining; (3) uniform DNA fluorescence with CMA3 and DAPI staining and (4) genomic composition considerably enriched both in highly- and…
Schistosomiasis reaches Europe
2015
International audience; An outbreak of urogenital schistosomiasis has been detected in Europe, with patients affected in France,1,2 Germany,1,2 and Italy. The infection originated in Corsica, in a river north of Porto-Vecchio, a popular tourist destination (figure). The introduction of schistosomiasis is believed to be associated with infected people arriving from a region endemic for the exclusively African parasite, Schistosoma haematobium and disseminating parasite eggs through their urine into snail breeding sites along the river.
Land Snails as a Diet Diversification Proxy during the Early Upper Palaeolithic in Europe
2014
Despite the ubiquity of terrestrial gastropods in the Late Pleistocene and Holocene archaeological record, it is still unknown when and how this type of invertebrate resource was incorporated into human diets. In this paper, we report the oldest evidence of land snail exploitation as a food resource in Europe dated to 31.3-26.9 ka yr cal BP from the recently discovered site of Cova de la Barriada (eastern Iberian Peninsula). Mono-specific accumulations of large Iberus alonensis land snails (Ferussac 1821) were found in three different archaeological levels in association with combustion structures, along with lithic and faunal assemblages. Using a new analytical protocol based on taphonomic…
Spermatocyte chromosome analysis of Helicella virgata (Pulmonata: Helicidae): silver-stained and C-banded chromosomes.
1991
Chromosome numbers of the snail Helicella virgata from the fields of Castellammare del Golfo (Sicily) are n = 26 and 2n = 52. Silver-staining analyses of testicular cells suggest that both mitotic and meiotic chromosomes are involved in nucleolus organization. A within-individual variability in NOR-banding pattern is present in each of the 20 specimens analyzed.
Ecological divergence of closely related Diplostomum (Trematoda) parasites.
2006
Parasite life-cycles present intriguing model systems to study divergence in resource use and ecology between parasite taxa. In ecologically similar taxa, consistent selective forces may lead to convergence of life-history traits, but resource overlap and similarity of life-cycles may also promote divergence between the taxa in (1) use of host species or (2) specific niche within a host. We studied the life-history characteristics of 2 sympatric species of Diplostomum parasites, D. spathaceum and D. gasterostei, concentrating particularly on differences in intermediate host use and characteristics of the infective stages between the species. This group of trematodes is a notoriously difficu…
Low toenail chromium concentration and increased risk of nonfatal myocardial infarction
2005
Chromium intake may increase insulin sensitivity, glucose tolerance, and the ratio of high density lipoprotein cholesterol to low density lipoprotein cholesterol. However, the epidemiologic evidence on the association between chromium and cardiovascular disease is very limited. To determine whether low toenail chromium concentrations were associated with risk of nonfatal myocardial infarction, the authors conducted an incident, population-based, case-control study in eight European countries and Israel in 1991-1992. Cases (n = 684) were men with a first diagnosis of myocardial infarction recruited from the coronary units of participating hospitals. Controls (n = 724) were men selected rando…
Survival and infectivity of Hypoderaeum conoideum and Euparyphium albuferensis cercariae under laboratory conditions.
1999
The survival characteristics of the cercariae of Hypoderaeumconoideum and Euparyphiumalbuferensis (Trematoda: Echinostomatidae) at 20°C and 30°C are described, and the age dependency of their infectivity at 20°C is studied to determine their respective transmission efficiencies. Cercarial survival was found to be age-dependent and was higher at 20°C. For both cercariae, the maximum life-span was 26 h at 20°C and 16 h at 30°C, and their respective times to 50% mortality were similar at each temperature. Both cercariae seem to be well adapted to transmission in their natural habitat, though cercarial infectivity of H. conoideum was higher than that of E. albuferensis, this being correlated wi…
Fasciola hepatica infection in children actively detected in a survey in rural areas of Mardan district, Khyber Pakhtunkhawa province, northern Pakis…
2018
Abstract Human fascioliasis is a freshwater snail borne, zoonotic disease caused by Fasciola liver flukes which are widely spread throughout Pakistan and has recently proved to be endemic in humans of the Punjab province. To verify whether fasciolids are also affecting humans outside this province, studies were conducted in four communities comprising rural and urban areas of Mardan district, Khyber Pakhtunkha province, northern Pakistan. Activities comprised two surveys, a coprological one to look for Fasciola infection and another to get information on potential human infection sources and risk factors by means of a questionnaire. Out of 540 subjects of all ages surveyed, only 4 children …