Search results for "host"

Double-balloon endoscopy for retrograde cholangiography in patients with choledochojejunostomy and Roux-en-Y reconstruction.

2009

BACKGROUND Choledochojejunal anastomoses with Roux-en-Y reconstruction excludes the biliary tract from conventional endoscopic retrograde cholangiography (ERC) with standard endoscopes due to the length of the interposed small bowel segment. Double-balloon enteroscopy (DBE) facilitates deep insertion into the small bowel and may be used to perform ERC in these patients. In the present case series we report our experience with diagnostic and therapeutic double-balloon ERC in patients with choledochojejunostomy to a long Roux-en-Y loop previously unavailable for standard length endoscopes. PATIENTS AND METHODS Between December 2004 and May 2008 15 patients (mean age: 60.2 years) with choledoc…

Molecular characterisation of Galba truncatula, Lymnaea neotropica and L. schirazensis from Cajamarca, Peru and their potential role in transmission …

2012

Abstract Background Human and animal fascioliasis is emerging in many world regions, among which Andean countries constitute the largest regional hot spot and Peru the country presenting more human endemic areas. A survey was undertaken on the lymnaeid snails inhabiting the hyperendemic area of Cajamarca, where human prevalences are the highest known among the areas presenting a "valley transmission pattern", to establish which species are present, genetically characterise their populations by comparison with other human endemic areas, and discuss which ones have transmission capacity and their potential implications with human and animal infection. Methods Therefore, ribosomal DNA ITS-2 an…

The Ecology of Hyperparasitoids.

2021

Hyperparasitoids are some of the most diverse members of insect food webs. True hyperparasitoids parasitize the larvae of other parasitoids, reaching these larvae with their ovipositor through the herbivore that hosts the parasitoid larva. During pupation, primary parasitoids also may be attacked by pseudohyperparasitoids that lay their eggs on the parasitoid (pre)pupae. By attacking primary parasitoids, hyperparasitoids may affect herbivore population dynamics, and they have been identified as a major challenge in biological control. Over the past decades, research, especially on aphid- and caterpillar-associated hyperparasitoids, has revealed that hyperparasitoids challenge rules on nutri…

Establishment and interspecific associations in two species of Ichthyocotylurus (Trematoda) parasites in perch (Perca fluviatilis)

2011

Abstract Background Co-infections of multiple parasite species in hosts may lead to interspecific associations and subsequently shape the structure of a parasite community. However, few studies have focused on these associations in highly abundant parasite species or, in particular, investigated how the associations develop with time in hosts exposed to co-infecting parasite species for the first time. We investigated metacercarial establishment and interspecific associations in the trematodes Ichthyocotylurus variegatus and I. pileatus co-infecting three age cohorts of young perch (Perca fluviatilis). Results We found that the timing of transmission of the two Ichthyocotylurus species was …

2014

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. 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. 15°C (control)] wi…

Considerations Regarding the Relevance of Direct Foreign Investments in the Global Economy

2019

Abstract It is well known that the current business world, and also the investments, today are based on the global markets expansion. Contemporary reality shows us the image of a world which is irreversibly evolving towards the businesses globalization and the companies’ internationalization. The internal markets often become overcrowded, and the companies access more profoundly the global marketplace, which not only provides a place for all competitors, but also represents a source of new advantages for all. In the context of globalization the investment activity has gained new dimensions, becoming a global one, with serious implications, which manifest itself over the national economies a…

Low-level environmental metal pollution is associated with altered gut microbiota of a wild rodent, the bank vole (Myodes glareolus)

2021

Mining and related industries are a major source of metal pollution. In contrast to the well-studied effects of exposure to metals on animal physiology and health, the impacts of environmental metal pollution on the gut microbiota of wild animals are virtually unknown. As the gut microbiota is a key component of host health, it is important to understand whether metal pollution can alter wild animal gut microbiota composition. Using a combination of 16S rRNA amplicon sequencing and quantification of metal levels in kidneys, we assessed whether multi-metal exposure (the sum of normalized levels of fifteen metals) was associated with changes in gut microbiota of wild bank voles (Myodes glareo…

Medium-term dynamics of element concentrations in a sparid fish and its isopod parasite after the Prestige oil-spill: Shifting baselines?

2019

Historically, the European Atlantic is probably the most important oil-spill hotspot worldwide. One of the most recent accidents occurred in 2002 when the oil-tanker Prestige sank over the Galician Bank causing two major oil-spills followed by several small leaks until March 2003. This resulted in contamination of virtually all types of marine habitat. Considering that parasites have proved to be good effect and accumulation bioindicators, the present study addresses the medium-term changes in trace element content after the Prestige oil-spill in a model host-parasite system, the bogue, Boops boops (Sparidae) and the isopod Ceratothoa oestroides. To our knowledge, this study is the first to…

Cyclodextrins as a Key Piece in Nanostructured Materials: Quantitation and Remediation of Pollutants

2021

Separation and pre-concentration of trace pollutants from their matrix by reversible formation of inclusion complexes has turned into a widely studied field, especially for the benefits provided to different areas. Cyclodextrins are non-toxic oligosaccharides that are well known for their host–guest chemistry, low prices, and negligible environmental impact. Therefore, they have been widely used as chiral selectors and delivery systems in the pharmaceutical and food industry over time. However, their use for extraction purposes is hampered by their high solubility in water. This difficulty is being overcome with a variety of investigations in materials science. The setting-up of novel solid…

Anti-HIV-1 activity of inorganic polyphosphates.

1997

Human blood plasma, serum, peripheral blood mononuclear cells, and erythrocytes contain significant amounts of inorganic polyphosphates (ranging from 53 to 116 microM, in terms of phosphate residues). Here we demonstrate that at higher concentrations linear polyphosphates display cytoprotective and antiviral activity. Sodium tetrapolyphosphate and the longer polymers, with average chain lengths of 15, 34, and 91 phosphate residues, significantly inhibited human immunodeficiency virus type 1 (HIV-1) infection of cells in vitro at concentrations > or = 33.3 microg/ml (> or = 283-324 microM phosphate residues), whereas sodium tripolyphosphate was ineffective. In the tested concentration range,…