Search results for "host"

Control of freshwater fish louse Argulus coregoni: a step towards an integrated management strategy

2008

Harmful infections by ectoparasites of the genus Argulus occur repeatedly in freshwa- ter fish farming operations where the management has largely been ineffective. Preventative meth- ods and regular monitoring are rarely applied, so that chemical interventions become necessary. According to the Integrated Pest Management (IPM) approach, a sustainable management or control program for a parasite should be based on knowledge of the ecology of the parasite along with adop- tion of several prevention and control methods, the application of which is dependent upon the pre- vailing infection level. The application of multiple management tactics is especially important because parasites can devel…

Transcriptional regulation of the proton translocating NADH dehydrogenase genes (nuoA-N) of Escherichia coli by electron acceptors, electron donors a…

1995

The promoter region and transcriptional regulation of the nuoA-N gene locus encoding the proton-translocating NADH:quinone oxidoreductase was analysed. A 560 bp intergenic region upstream of the nuo locus was followed by a gene (designated lrhA for LysR homologue A) coding for a gene regulator similar to those of the LysR family. Disruption of lrhA did not affect growth (respiratory or non-respiratory) or expression of nuo significantly. Transcriptional regulation of nuo by electron acceptors, electron donors and the transcriptional regulators ArcA, FNR, NarL and NarP, and by IHF (integration host factor) was studied with protein and operon fusions containing the promoter region up to base …

Redox-Responsive Host–Guest Chemistry of a Flexible Cage with Naphthalene Walls

2020

"Naphthocage", a naphthalene-based organic cage, reveals very strong binding (up to 1010 M-1) to aromatic (di)cationic guests, i.e., the tetrathiafulvalene mono- and dication and methyl viologen. Intercalation of the guests between two naphthalene walls is mediated by C-H···O, C-H···π, and cation···π interactions. The guests can be switched into and out of the cage by redox processes with high binding selectivity. Oxidation of the flexible cage itself in the absence of a guest leads to a stable radical cation with the oxidized naphthalene intercalated between and stabilized by the other two. Encapsulated guest cations are released from the cavity upon cage oxidation, paving the way to futur…

Human interleukin 2: molecular biology, physiology and clinical possibilities.

1986

The addition of interleukin-2 to cyclophosphamide therapy can facilitate tumor growth of B16 melanoma.

1995

The role of interleukin-2 (IL-2) on tumor growth of B16F10 melanoma cells was assessed in two sets of mice with different immune status: normal (immunocompetent) mice and immunodeficient mice. The two sets of animals were treated with cyclophosphamide (CY) or IL-2 alone or with a combined therapy of CY+IL-2. On days 6 and 10 after tumor cell injection, we evaluated the incidence of hepatic B16 melanoma metastases and the percentage of hepatic volume occupied by metastatic tissue. We observed that the CY alone (300 mg/kg, days 3 and 8 post-tumoral inoculation) significantly reduced tumor growth in all treated mice; however, CY proved more effective in normal recipients than in immunodeficien…

Intestinal Trematode Infections

2014

Intestinal trematodes are among the most common types of parasitic worms. About 76 species belonging to 14 families have been recorded infecting humans. Infection commonly occurs when humans eat raw or undercooked foods that contain the infective metacercariae. These parasites are diverse in regard to their morphology, geographical distribution and life cycle, which make it difficult to study the parasitic diseases that they cause. Many of these intestinal trematodes have been considered as endemic parasites in the past. However, the geographical limits and the population at risk are currently expanding and changing in relation to factors such as growing international markets, improved tran…

Velando armas

2002

Resumen cronoestratigráfico de las rocas ígneas de Costa Rica basado en dataciones radiométricas

1992

Resume El presente trabajo recopila los resultados de aproximadamente 160 dataciones radiometricas K-Ar y U-Th que se han realizado en Costa Rica en los ultimos 20 anos. Con base en estas dataciones y en relaciones estratigraficas se establecio un cuadro cronoestratigrafico sobre la evolucion del magmatismo desde el Mesozoico hasta el presente. Las rocas igneas del Jurasico hasta el Oligoceno se caracterizan por su tendencia toleitica. A partir del Mioceno tardio predominan rocas de la serie calcoalcalina y la actividad volcanica culmina en el Pleistoceno con la erupcion de grandes volumenes de ignimbritas en la parte norte y central de Costa Rica y la edificacion de los estratovolcanes de …

European expert opinion on the management of invasive candidiasis in adults

2011

Item does not contain fulltext This report discusses the present status of antifungal therapy and treatment options for candidaemia, considered by experts in the field in Europe. A conference of 26 experts from 13 European countries was held to discuss strategies for the treatment and prevention of invasive candidiasis, with the aim of providing a review on optimal management strategies. Published and unpublished comparative trials on antifungal therapy were analysed and discussed. Commonly asked questions about the management of candidaemia were selected, and possible responses to these questions were discussed. Panellists were then asked to respond to each question by using a touchpad ans…

Costs of parasite resistance for female survival and parental care in a freshwater isopod

2006

Parasite resistance is expected to be costly because activation and maintenance of immune system requires energy that will not be available for other fitness related functions. Here, we experimentally exposed gravid female isopods from two lake populations to trophically transmitted acanthocephalan parasite. Successful establishment of the parasite requires penetration to body cavity; therefore, it is likely to induce an immune response. Resistant females from a lake where the parasite occurs as well as from a lake without the parasite experienced higher mortality than susceptible or control females. Parasite exposure reduced the offspring size at birth in both susceptible, but especially, …