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At least 19 recordsLinked to original sources
PubMed1984

Interactions between Moniliformis (Acanthocephala) and Nippostrongylus (Nematoda) in the small intestine of laboratory rats.

Rats harbouring a 35-day-old primary infection of Moniliformis dubius were inoculated with constant doses of Nippostrongylus brasiliensis and 10 days later, after post mortem examination, rats with concurrent infections harboured significantly fewer Nippostrongylus than rats with single infections. Similar infections of Moniliformis were carried out, but with post mortem taking place on days 8, 9, 12 and 14 of the Nippostrongylus infections. On days 8 and 9 of infection, rats with concurrent infections did not harbour significantly fewer Nippostrongylus compared with single infections. Both single and concurrent infections of 12- and 14-day-old Nippostrongylus were found to harbour lower numbers of worms. In the single infection this corresponds to the timing of the typical immune expulsion of a primary single infection which takes place on approximately day 12 of infection. The Moniliformis population was not significantly affected, in terms of numbers, dry weight and length, although each parasite population did show a slight shift in site in the presence of the other. A significant reduction in egg production by Nippostrongylus was detected throughout concurrent infection. The possible role of non-reciprocal cross-immunity is discussed as an explanation for the apparent early expulsion of the Nippostrongylus population in the presence of Moniliformis.

Animals↗
PubMed1994

Effects of Plasmodium berghei (Apicomplexa) on Nippostrongylus brasiliensis (Nematoda) infection in the mouse, Mus musculus.

Ova and free oxygen radical production and relative peripheral eosinophilia during single and concurrent infections in mice with P. berghei and N. brasiliensis were investigated. Prolonged helminth patent periods indicate that Nippostrongylus self-cure in concurrently infected mice was suppressed. Differential white blood cell determinations showed that the relative number of peripheral blood eosinophils steadily increased (P < or = 0.05) during a Nippostrongylus infection when compared to noninfected controls. Eosinophil levels in mice singly infected with P. berghei or concurrently infected with both parasites did not differ significantly from those of controls suggesting a suppression by Plasmodium of Nippostrongylus-induced eosinophilia. Generation of intestinal free oxygen radicals was indirectly assessed using the Thiobarbituric Acid Assay to measure malondialdehyde (MDA). Intestinal MDA levels were significantly elevated (P < or = 0.05) during single Plasmodium infections as well as concurrent infections while there was no change in MDA production during single Nippostrongylus infections. These results suggest suppression by Plasmodium of the immune response to Nippostrongylus, allowing prolonged patent periods. They also suggest that eosinophils play a role in self-cure while free oxygen radicals do not.

Animals↗
PubMed1977

Immune mechanism of rats on Nippostrongylus brasiliensis in vitro. II. The influence of lymphocytes and peritoneal cells.

Nippostrongylus were collected from the intestines of rats 6 days p.i. and kept under sterile conditions in cultures. Serum, lymphocytes and peritoneal cells of immune or non-infected animals were added in various combinations to the culture media. The culture media were changed 2-3 times in an experimental period of 10 days, resp. serum and cells were added. The lymphocytes were isolated from the peripheral blood or from the mesenterial lymph nodes whereas the mononuclear cells were obtained from the peritoneal cavity. Serum and lymphocytes from the peripheral blood both from immune and non-infected rats, had no increased lethal effect on Nippostrongylus. The highest lethality rate of adults (65-68%) was achieved in cultures with peritoneal cells and lymphocytes from the lymph nodes of sensitized rats. Serum of infected or non-infected animals had no influence on adult Nippostrongylus in cultures with these cell combinations. In the controls without any cell-supplements the survival rate of the parasites was up to 88%.

Ancylostomatoidea↗
PubMed2005

Th2 induction by Nippostrongylus secreted antigens in mice deficient in B cells, eosinophils or MHC Class I-related receptors.

The populations of immune system cells necessary for induction of the Th2 response have yet to be fully defined. Among the most consistent natural stimuli for Th2 responses are helminth parasites, such as the gastrointestinal nematode Nippostrongylus brasiliensis. Strong Th2 bias in immune responsiveness to live parasite infection can be reproduced by injection of a soluble Nippostrongylus excretory/secretory product (NES) collected from adult worm parasites in vitro. Injection of soluble NES induces a residual type-2 response (IL-13) even in IL-4-deficient mice, and drives a fully polar Th2 response in IL-5-deficient animals. A potent IL-10 response is observed irrespective of IL-4 or IL-5 gene status. While MHC Class II knockout animals fail to mount any IL-4 or IL-10 response, the Th2 bias is intact in Class I knockouts, indicating that CD8+ or NK-like T cells restricted to classical or non-classical Class I molecules do not play an essential role in Th2 induction. B cell-deficient microMT animals also show responses, which are strongly skewed to IL-4 production. Thus, Th2 induction by Nippostrongylus antigens is independent of B cells, or MHC class I presentation, and does not require a sufficiency of eosinophils in vivo.

Animals↗
PubMed1987

Interspecific effects between Moniliformis (Acanthocephala), Hymenolepis (Cestoda) and Nippostrongylus (Nematoda) in the laboratory rat.

Rats harbouring 35-day-old primary infections of Moniliformis moniliformis and Hymenolepis diminuta were inoculated with equal doses of Nippostrongylus brasiliensis and were autopsied 10 days later. Significant reductions were found in the dry weight of Moniliformis and Hymenolepis and in the numbers of Nippostrongylus recovered compared with single infections. Similarly, in infections with two parasites, the numbers of Nippostrongylus were reduced when concurrent with Moniliformis and the dry weights of Moniliformis and Hymenolepis decreased in the presence of each other. A comparison of the concurrent infections themselves revealed that Moniliformis weighed significantly less in the presence of Hymenolepis than in the three parasite infections. Parasite interactions and their possible mechanism are discussed and comparisons are made with the relevant single infection for each parasite.

Animals↗
PubMed1976

[Immune mechanism of rats on Nippostrongylus brasiliensis in vitro (author's transl)].

The influence of humoral and secretory antibodies as well as cell supplements on Nippostrongylus brasiliensis was tested in vitro. Adult Sprague-Dawley-rats approximately 12 weeks of age were used in these experiments. For the in vitro tests the following culture media were used: 25% chicken-embryo-extract, sodium casein, pig liver extract and rat serum for the larval stages. The medium for the cultures of adult N. brasiliensis consisted of 5% yeast extract, 15% casein, 30% Krebs-Ringer-solution and 50% rat serum. Secretory antibodies were isolated from the rinsing fluid of the rat intestines by high pressure filtration (10 to 15 micron), then cleaning of the fluid through a Sephadex G 15 column and finally narrowing down through collodene capsules. Mast cells were isolated from the peritoneal cavity by Ficoll-gradient-centrifugation. Various test series were conducted with the addition of serum or secretory antibodies of repeatedly infected and immune rats to the medium. In these tests there was never a difference in the influence on growth nor a higher mortality rate of larval or adult N. brasiliensis in contrast to cultures where serum and secretory antibodies of non-infected animals were used. A 100%, degranulation of mast cells from infected rats occurred already within 14 to 22 hours in the cultures of adult N. brasiliensis. Variations were not noticed in the influence on the viability of N. brasiliensis kept in media for 10 days without or with cell supplements as well as sera of infected or not infected rats. The results from our experiments demonstrated that there was no variation in the influence on the development and a higher mortality rate of the larval stages and adult Nippostrongylus in media containing either sera and secretory antibodies of infected or not infected rats.

Ancylostomatoidea↗
PubMed1985

Characterization of antigens of the nematode Nippostrongylus brasiliensis by monoclonal antibodies.

Hybridomas secreting monoclonal antibodies to Nippostrongylus brasiliensis antigens were generated by hybridization of IR983F myeloma cells with spleen cells from Lou/M/Wol rats infected with living third-stage larvae. Antibodies specific either for larval or worm antigens were identified by enzyme-linked immunosorbent assays with Nippostrongylus brasiliensis fragments, homogenates and secretions as antigens. The results demonstrate that all antibodies which recognized larval antigens (38 antibodies) also reacted with worm surfaces. Ten antibodies were specific only for worm antigens. Ten antibodies reacted with worm homogenate, three antibodies recognized components of worm secretion and 17 antibodies combined with acetylcholinesterase. The epitope specificity was investigated by the capacity of various glycosides, aminoacids, N-acetylneuraminic acid and phosphorylcholine to inhibit the binding to worm fragments. The analysis revealed that alpha-methylglucoside, alpha-methylmannoside, N-acetylglucosamine, N-acetylgalactosamine, fucose and the amino acids leucine, phenylalanine, tyrosine, serine, tryptophan did not combine with the antigen-binding sites of the antibodies. Proline, arginine and histidine, however, displayed inhibitory effects. With N-acetylneuraminic acid as inhibitor three groups of antibodies could be discriminated. At a concentration of 10-20 mM, phosphorylcholine was a potent inhibitor for all antibodies.

Acetylcholinesterase↗
PubMed1990

Intestinal mucosal mast cells in Nippostrongylus-infected mice: lack of sensitivity to corticosteroids.

Immune reactions to enteric nematodes, in which mast cells are thought to play an important role, are abrogated following corticosteroid treatment of host animals. This is probably due, at least in part, to inhibition of cytokine production by T cells. It has proved difficult to block worm expulsion in mice with corticosteroids. We have therefore examined the effects of corticosteroids on mast cell numbers and concentrations of the mast cell granule-specific serine protease Mouse Intestinal Mast Cell Protease (MIMCP) in the intestines of mice infected with Nippostrongylus brasiliensis. Mucosal mast cell (MMC) numbers and concentrations of MIMCP were unaltered by steroid treatment. This is in marked contrast to Nippostrongylus-infected rats which showed decreases in both mast cell numbers and concentrations of the rat mucosal mast cell protease RMCP II after steroid treatment. This suggests that differentiated murine MMC are less dependent on T cells than those of the rat.

Animals↗
PubMed1998

Immunocytochemical detection of vasoactive intestinal peptide-like and peptide histidine isoleucine-like peptides in the nervous system and the excretory system of adult Nippostrongylus brasiliensis.

Vasoactive intestinal peptide-like and peptide histidine isoleucine-like immunoreactivities were detected in the excretory duct of adult male and female Nippostrongylus brasiliensis, thus indicating the source of these two physiologically active peptides previously isolated from the excretory/secretory products of adult N. brasiliensis. In the nervous system immunoreactivity to both these peptides was confined to females and was found in the neurons of the ovijector associated ganglion. This is consistent with co-synthesis of vasoactive intestinal peptide-like and peptide histidine isoleucine-like peptides which has also been shown to occur in all mammalian vasoactive intestinal peptid-ergic neurons studied to date. However, in addition to this, and in common to some previous studies on helminth vasoactive intestinal peptide and peptide histidine isoleucine immunoreactivities, co-synthesis of the peptides was not indicated in a pair of branched neurons which projected posteriorly and peripherally from the ganglion associated with the ovijector of females and which terminated in two pairs of ganglia also exhibiting vasoactive intestinal peptide-like immunoreactivity only. The position of these ganglia indicated that they innervate muscles close to the body wall and may be responsible for the muscular contractions required for expulsion of eggs from female Nippostrongylus brasiliensis. This is also the first study to successfully detect these peptides in the excretory system of gastrointestinal nematodes.

Animals↗
PubMed1993

Histamine releasing activity and its inhibition by supernatants from cultured lymphoid cells of Nippostrongylus brasiliensis-infected rats.

The influence of Nippostrongylus brasiliensis infection on the capability of HRF (Histamine Releasing Factor) generation by rat lymphoid cells in vitro has been studied. Spleen cells and thymocytes of normal and Nippostrongylus brasiliensis-infected rats were cultured in the presence of nonspecific mitogen (PHA) or specific N. brasiliensis antigen (NbAg), and cell-free supernatants fractionated by Sephadex G-75 chromatography were tested on homologous mast cells for histamine releasing activity. The results show that PHA-stimulated lymphoid cells from both normal and infected rats produced a factor releasing histamine from mast cells. Histamine releasing activity was not detected when lymphoid cells of N. brasiliensis-infected rats were cultured in the presence of NbAg. Moreover, supernatants of these cultures diminished HRF-induced histamine release from mast cells, suggesting the production of factor(s) inhibiting this release. This histamine release inhibiting activity was detected in fractions in Sephadex G-75 chromatography of supernatants from the cultures of NbAg-stimulated thymocytes of infected rats.

Animals↗
PubMed1985

Dose-dependent relationships between Nippostrongylus brasiliensis populations and rat food intake.

The pattern of daily food intake of well-nourished rats infected with Nippostrongylus brasiliensis included 2 distinct phases when food intake was much less than that of uninfected controls (days 0-4 and days 6-10 p.i.). These phases were separated by a period (days 4-6) of still reduced but relatively constant food intake. From day 10 p.i. food intake increased so that between days 12 and 17 infected rats ate more than uninfected controls. In each of the phases of reduced food intake there was a threshold dose above which food intake was further decreased as dose increased. In contrast to the obvious relationship between food intake and dose, food intake could not easily be related to the size of the adult Nippostrongylus population, as judged by egg and worm counts. The relationship appears to be complicated by host variability in susceptibility to infection and to the pathological effects of infection. Effects of N. brasiliensis on the daily pattern of food intake can be explained with respect to stages in the development of the parasite and host responses directed against the adult worms.

Animals↗
PubMed1987

The effect of protein deficiency on systemic release of rat mucosal mast cell protease II during Nippostrongylus brasiliensis infection and following systemic anaphylaxis.

Serum rat mucosal mast cell protease II (RMCPII) was measured in protein-deficient rats to assess mucosal mast cell (MMC) activation during primary infection with the nematode, Nippostrongylus brasiliensis, and during systemic anaphylaxis produced by Nippostrongylus antigen in immune animals. In the first study, serum RMCPII increased 4-fold by day 15 after infection. By day 20, serum RMCPII continued to rise in protein-deficient animals, but decreased in nutritionally normal animals. This was associated with impaired worm rejection in protein-deficient rats. During systemic anaphylaxis, serum RMCPII was elevated in three groups of protein-deficient rats on 6%, 8% and 10% low protein diets and in nutritionally normal rats. All protein-deficient rats exhibited 3 to 7-fold less mucosal permeability of the small intestine to Evan's blue dye injected intravenously compared to nutritionally normal animals following anaphylactic stimulation. These results demonstrated that MMC are activated during infection in protein deficiency, and suggest that reduced MMC function does not explain delay in worm expulsion. Impaired mucosal anaphylaxis in protein deficiency could not be attributed to a failure of MMC response.

Anaphylaxis↗
PubMed1999

Partial cross-resistance between Strongyloides venezuelensis and Nippostrongylus brasiliensis in rats.

Rats were immunized through an initial infection with 1,000 filariform larvae (L3) of Nippostrongylus brasiliensis and after complete expulsion of worms they were challenged with 1,000 L3 of Strongyloides venezuelensis to investigate whether cross-resistance developed against a heterologous parasite. Nippostrongylus brasiliensis-immunized rats developed a partial cross-resistance against S. venezuelensis migrating larvae (MSL3) in the lungs and adult worms in the small intestine. The population of MSL3 in the lungs were significantly lower (P < 0.05) in immunized rats (22.0 +/- 7.4) compared with controls (105.0 +/- 27.6). The populations of adult worms, egg output and fecundity were initially decreased but from day 14 post-challenge they did not show any significant difference between immunized and control rats. However, the length of worm in immunized rat was revealed as retardation. Peripheral blood eosinophilia was significantly decreased (P < 0.05) on day 7 post-challenge and then gradually increased, which peaked on day 42 post-challenge when most of the worms were expelled. These results suggest that peripheral blood eosinophilia is strongly involved in the worm establishment and expulsion mechanisms.

Animals↗
PubMed2006

Anthelmintic efficacy of extracts of Spigelia anthelmia Linn on experimental Nippostrongylus braziliensis in rats.

Spigelia anthelmia Linn is used as a herb and is a common annual weed of cultivation in open re-growths, on unused land in towns as well as on road sides. The plant can grow to approximately 30 cm in height. The aim of this study was to screen extracts of Spigelia anthelmia for their anthelmintic activity against an experimental Nippostrongylus braziliensis infection in rats. Acute oral toxicity occurred at a dose of 1,140 mg/kg, while anthelmintic trials against Nippostrongylus braziliensis in rats using the aqueous fraction showed a progressive decrease in worm count with increasing dose (10, 13, 16, 20 and 25 mg per kg body weight) (p < 0.05). At 25 mg per kg body weight, the worm count was significantly lower than that at 10 mg per kg body weight (p < 0.05).

Animals↗
PubMed2000

[Effect of Nippostrongylus brasiliensis induced alterations in T helper cell subsets on Plasmodium berghei infection in mice].

OBJECTIVE: To observe the anti-P. berghei ability of C57BL/6 mice after infected with Nippostrongylus brasiliensis alterations in T helper cell subsets in the course of Plasmodium infection, and the effect of the alteration on host's prognoses. METHODS: C57BL/6 mice were infected with Nippostrongylus brasiliensis subcutaneously, 3 wk later, the mice were injected with Plasmodium berghei intraperitoneally. The parasitemia was monitored daily. On days 0, 3 and 9, RNA from the spleens of infected mice was prepared for PT-PCR to analyse the changes of IFN-gamma and IL-4 mRNA during the infection course. RESULTS: Compared with control group, the peak-reaching time of parasitemia in the experiment group was delayed, and the bearing capacity of mice to malaria infection and the surviving time increased obviously. The IL-4 level in the experiment group was higher than that in the control group on day 0 of P. berghei infection, but all raised abnormally in both groups at the early stage of the infection; while IFN-gamma level in the experiment group was higher than that in the control group on day 3 after infection, and then began to reduce to some extent on day 9 of the infection in the experiment group. CONCLUSION: T helper cell subsets play an important role in antimalarial immunoregulation in mice.

Animals↗
PubMed1979

Mast cells in severely T-cell depleted rats and the response to infestation with Nippostrongylus brasiliensis.

The effect of severe T-cell depletion on mucosal mast cells of the small intestine and on connective tissue mast cells has been studied in adult thymectomized, irradiated, bone marrow reconstituted (B) rats. Under normal conditions, intestinal mucosal mast cell numbers do not differ significantly between B rats, normal age matched rats and non-thymectomized irradiated controls. Connective tissue mast cells are significantly fewer in the tongues of B rats than in normal rats, but the difference is atributable to an effect of irradiation. Infestation with Nippostrongylus brasiliensis produced approximately equal increases in mucosal mast cells in non-thymectomized irradiation controls and in normal rats. In B rats there was no increase in mucosal mast cells following infestation. B rats failed to expel the parasites normally. Failure of mast cell proliferation was not due to the effects of the persisting worm burden. Antihelminthic treatment at the time of worm expulsion by normal rats did not reveal a hitherto masked mast cell response in B rats. Nippostrongylus infestation did not reveal evidence of thymus-dependency of connective tissue mast cells. As in athymic nude mice, mucosal mast cells in the rat have been shown to be T-cell dependent during the proliferation that follows infestation with an intestinal nematode parasite.

Animals↗
PubMed1979

Immunization against Nippostrongylus brasiliensis in the rat. A study on the use of antigen extracted from adult parasites and the parameters which influence the level of protection.

It was found that protective immunity in excess of 90% reduction in worm burden could be stimulated against Nippostrongylus brasiliensis in rats by using an extract of adult Nippostrongylus worms. The level of protection achieved was influenced by several factors. Thus, the use of Bordetella pertussis as adjuvant significantly increased the level of protection which, in addition, was shown to be influenced by the amount of worm antigen used. Furthermore, antigen administered in multiple doses was more effective than a single inoculum and, when using such a regime, the interval between doses was also found to be critical. The route of antigen administration was important and, while protection was achieved by subcutaneous and oral administration, the intraperitoneal route was the most effective. Using the optimal immunization regime of 3 doses of 5 mg worm protein and 4 x 10(10( B. pertussis organisms, as adjuvant, levels of protective immunity in excess of 90% reduction in worm burden were shown to exist for at least 60 days after the last dose. It was found that adult worm extracts did not stimulate any obvious immunity against larval forms of N. brasiliensis.

Adjuvants, Immunologic↗
PubMed1979

Changes in the structure of Nippostrongylus brasiliensis intestinal cells during development from the free-living to the parasitic stages.

The ultrastructure of Nippostrongylus brasiliensis intestinal cells was examined in free-living, feeding second-stage larvae, infective, nonfeeding third-stage larvae, and parasitic, feeding third-stage larvae. The intestinal cells of second-stage larvae were characterized by a well-developed microvillar border, large numbers of ribosomes, Golgi complexes, rough endoplasmic reticulum, and nuclei with prominent nucleoli. The intestinal cells of infective, third-stage larvae had very few microvilli and the cells were extremely narrow. Few ribosomes, Golgi complexes, and little rough endoplasmic reticulum were present. Nuclei did not contain nucleoli. When worms were introduced into an in vitro culture system, development of intestinal cells began. By 36 hr, microvilli were well differentiated and the cysoplasm contained numerous ribosomes and Golgi complexes, and rough endoplasmic reticulum, mitochondria, and nucleoli were prominent. These morphological changes were related to changes in the physiology of Nippostrongylus brasiliensis which occur during development from a free-living to parasitic form.

Animals↗