The development of immunity to Nematospiroides dubius was studied in three strains of inbred mice (BALB/c, C3H and NIH). Although a primary infection in NIH mice persisted for two months without evidence of a reduction in worm numbers, female mice of this strain readily developed resistance to reinfection. The degree of resistance was enhanced when an immunizing infection of 600 larvae was admi...

Lactating rats reinfected with Nippostrongylus brasiliensis fed low-crude protein (CP) foods show reduced lactational performance and less resistance to parasites compared with their high-CP counterparts. Here, we hypothesised that feeding high-CP foods deficient in specific essential amino acids (AA) would result in similar penalties. Second-parity lactating rats, immunised with 1600 N. brasil...

Expulsion of intestinal nematode parasites and the associated increased contraction by intestinal muscle are T cell dependent, since both are attenuated in athymic rodents. The CD4 T-cell subset has been strongly associated with worm expulsion; however, the relationship between these cells, antigen presentation, and worm expulsion is not definitive and the role of these factors in intestinal mu...

Recent epidemiological observations from field studies indicated that sheep selected for resistance to digestive nematodes were more infected than susceptible ones with the nasal bot fly, Oestrus ovis. The present study was undertaken to verify these informations and to explore the possible associated mechanisms. After a whole grazing season and an anthelmintic drench, two groups of 6 rams belo...

Forty-one wild sheep (Ovis ammon orintalis) from Kabodan Island of National Park of Urmia Lake (North-West of Iran), were examined during a period of six months from October 2002 to March 2003, for helminthes and coccidian infection. The numbers of oocyst and eggs per gram of faeces (OPG & EPG) were determined by the centrifuge flotation technique using saturated sugar solution. The rate of inf...

This study was carried out to evaluate the immune response in young Ile de France (IF) and Santa Ines (SI) sheep naturally infected by Oestrus ovis and gastrointestinal nematodes (GIN). Mast cells, eosinophils and globule leucocytes were enumerated in the upper respiratory tract (septum, middle meatus and ventral nasal conchae) and in the mucosa of abomasum and small intestine. Immunoglobulin G...

BACKGROUND The trehalose metabolic enzymes have been considered as potential targets for drug or vaccine in several organisms such as Mycobacterium, plant nematodes, insects and fungi due to crucial role of sugar trehalose in embryogenesis, glucose uptake and protection from stress. Trehalose-6-phosphate phosphatase (TPP) is one of the enzymes of trehalose biosynthesis that has not been reporte...

Once animals have experienced a helminthic infection, they often show stronger protective immunity against subsequent infections. Although helminthic infections are well known to elicit Th2-type immune responses, it remains ill-defined where and how acquired protection is executed. Here we show that skin-invading larvae of the intestinal helminth Nippostrongylus brasiliensis are surrounded by s...

Discussion It is obvious from these results that there was a significant exposure,t.o filariasis in the I mine workers, resulting in the productiov of anti-filarial antibodies. In the case of IgGl it is possiblq that the antibody response was due to exposure tdin-coming infective larvae rather than infection with the adult parasite, as there is a n active infective larvae (Km. As previously not...

Marine invertebrate larvae typically take hours to weeks after being released into the plankton before becoming "competent" to metamorphose. The mechanisms that govern this transition between the precompetent and metamorphically competent states are unknown. We studied gene expression patterns in precompetent and competent larvae of the salt-marsh-dwelling polychaete worm Capitella teleta (Blak...