摘要:

AbstractIntestinal helminths exhibit two types of circadian rhythms, either involving the migration of adults worms (HymenolepisandSyphacia) within the gut or periodic release of eggs by female worms (AspiculurisandHeligmosomoides) to the exterior of the host to maximize transmission efficiency. By modifying the feeding regimes of rodents, there is clear evidence that these rhythmic processes are directly linked with the digestive and defaecating activities of the host with neurohormonal control mechanisms likely to be involved at least in the migratory behaviour of adult worms. Furthermore, inHeligmosomoides polygyrusrhythmic egg output appears to be dependent upon parasite age and the population density of the host and parasite. A brief reference is also made to studies on long‐term rhythms of egg output by intestinal nematodes and their effect on patterns of host faecal productio

ISSN:0305-1838    

DOI:10.1111/j.1365-2907.1987.tb00058.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

AbstractImmune responses are considered to play an important role in the regulation of parasite populations, by virtue of their influences upon the establishment, development, survival and reproduction of parasites in individual hosts. The capacity of hosts to generate and express effective responses is genetically determined and, therefore, variable in a genetically heterogeneous population. Survival of parasites is enhanced when the host's capacity is reduced or absent. Low‐ or non‐responder hosts may play an important part in maintaining parasite population levels. Data derived from field or experimental studies of infections in small mammals are used to illustrate the relationships between genetics, immunity and parasite survi

ISSN:0305-1838    

DOI:10.1111/j.1365-2907.1987.tb00059.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

ISSN:0305-1838    

DOI:10.1111/j.1365-2907.1987.tb00060.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

AbstractIn the wild, small mammals are frequently infected with more than one parasite. Laboratory studies have revealed complex interactions between parasites and also between parasitic protozoa and viruses or bacteria. In general, infection with many parasites is accompanied by a period of immunodepression during which superimposed infections are favoured, giving rise to more intense and prolonged secondary infections while the original infection is unaffected. On the other hand, organisms that activate macrophages may protect die host against a subsequent infection. These kinds of interactions have been investigated in the laboratory usingTrypanosoma musculi, T. lewisi, Giardia muris, Spironucleus muris, Babesia microtiandHeligmosomoides polygyrus, all of which occur in British small mammals, suggesting that such interactions occur in the field, are worth investigating and should be considered in epidemiological studies.

ISSN:0305-1838    

DOI:10.1111/j.1365-2907.1987.tb00061.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

ISSN:0305-1838    

DOI:10.1111/j.1365-2907.1987.tb00062.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

ISSN:0305-1838    

DOI:10.1111/j.1365-2907.1987.tb00063.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY