The influence of the nematode Syphacia oblevata on adjuvant arthritis in the rat. (1/21)

The effect of infestation with the nematode Syphacia oblevata on adjuvant arthritis was studied in the rat. Animals with an established infestation with Syphacia were found to have a reduced incidence of arthritis after injection of Freund's complete adjuvant. Infested animals developing adjuvant arthritis were found to suffer from a less severe form of the disease than animals in which infestation had been eliminated with piperazine before immunization.  (+info)

Experimental eradication of pinworms (Syphacia obvelata and Aspiculuris tetraptera) from mice colonies using ivermectin. (2/21)

A spray administration of ivermectin was evaluated for the treatment of pinworm infection in mice. In this study, a spray of 0.1% ivermectin injectable solution over the entire cage once a week, for three consecutive weeks (one cycle treatment), was effective in eradicating both Syphacia obvelata and Aspiculuris tetraptera from mice under experimental conditions. In addition, no acute toxicity was observed in 105 mothers or 687 neonates treated with ivermectin, indicating that ivermectin does not affect murine reproduction. Finally, we attempted to eradicate pinworms from infected mice in our institute using this method. Two cycles of treatment were administered, with a two-week pause between cycles, resulting in complete eradication for at least one year. Treating mouse colonies with spray ivermectin is inexpensive, safe, requires very little labor and is very effective at eradicating pinworms from mice.  (+info)

Patterns of infection with the nematodes Syphacia obvelata and Aspiculuris tetraptera in conventionally maintained laboratory mice. (3/21)

Data on the frequency, distribution and mean intensity of the helminth fauna recovered from outbred and inbred mice conventionally maintained in Brazilian animal houses, are reported. The oxyurid nematodes Syphacia obvelata and Aspiculuris tetraptera presented overall frequencies of 91.5% and 8.5%, respectively. The frequency of S. obvelata in animals of three groups out of the four investigated ranged from 9% to 74% and A. tetraptera from 17% to 83%, since animals of one of the groups were negative for helminths. Infections due to a single species were observed in 62% of the animals, compared to 16% related to associations. The frequency of single infections in each group varied from 58.6% to 100% whereas associations varied from 24.1% to 41.4%. The analysis of specific mean intensities showed that S. obvelata was represented by 13.35 to 66.58 specimens/host and A. tetraptera by 5.85 to 16.75 specimens/host.  (+info)

Correlated evolution between host immunity and parasite life histories in primates and oxyurid parasites. (4/21)

Maturation time is a pivotal life-history trait of parasitic nematodes, determining adult body size, as well as daily and total fecundity. Recent theoretical work has emphasized the influence of prematurational mortality on the optimal values of age and size at maturity in nematodes. Eosinophils are a family of white blood cells often associated with infections by parasitic nematodes. Although the role of eosinophils in nematode resistance is controversial, recent work has suggested that the action of these immune effectors might be limited to the larval stages of the parasite. If eosinophils act on larval survival, one might predict, in line with theoretical models, that nematode species living in hosts with large eosinophil numbers should show reduced age and size at maturity. We tested this prediction using the association between the pinworms (Oxyuridae, Nematoda) and their primate hosts. Pinworms are highly host specific and are expected to be involved in a coevolutionary process with their hosts. We found that the body size of female parasites was negatively correlated with eosinophil concentration, whereas the concentration of two other leucocyte families-neutrophils and lymphocytes-was unrelated to female body size. Egg size of parasites also decreased with host eosinophil concentration, independently of female size. Male body size was unrelated to host immune parameters. Primates with the highest immune defence, therefore, harbour small female pinworms laying small eggs. These results are in agreement with theoretical expectations and suggest that life histories of oxyurid parasites covary with the immune defence of their hosts. Our findings illustrate the potential for host immune defence as a factor driving parasite life-history evolution.  (+info)

Vulvovaginitis: causes and management. (5/21)

Over a period of 33 months in a paediatric accident and emergency department, the clinical pattern and possible causes of vulvovaginitis were studied prospectively in 200 girls presenting with genital discharge, irritation, pain, or redness. The major causes were poor hygiene and threadworms. The suspicion of sexual abuse arose in a few girls but no organisms of sexually transmitted disease were found. Urinary symptoms were common but only 20 patients had a significant bacteriuria and 40 had sterile pyuria. Specific skin problems occurred in 28 cases. Simple measures to improve hygiene and treatment of threadworms gave effective relief. Genital irritation caused urinary symptoms with no clinical evidence of infection, and it is advised that antibiotic treatment should await urine culture. Specific skin problems require help from a dermatologist. The possibility of sexual abuse must be considered especially if the vulvovaginitis is persistent or recurrent after adequate treatment.  (+info)

Comparison of the effects of local and uncontrolled levamisole preparations on mice naturally infected with Aspiculuris tetraptera. (6/21)

This study was performed to compare effectiveness of two levamisole preparations prepared in two different countries (Iran and Turkey) in mice naturally infected with Aspiculuris tetraptera. For this purpose, natural infection was diagnosed using the cellophane tape method on the perianal region and centrifugal flotation technique on the feces of mice obtained from the experimental Animal Unit of the Faculty of Medicine, University of Yuzuncu Yil, Van. Mice naturally infected with A. tetraptera were then divided in three groups. Animals in Group 1 (8 animals) received levamisole prepared in Iran, animals in Group 2 (8 animals) received levamisole prepared in Turkey and animals in Group 3 (6 animals) were used as untreated controls. Both levamisole preparations were used in a 10 mg/kg dose. After drug administrations, stool samples of the animals in all groups were examined for seven days. On the eighth day, the animals were humanely destroyed using inhalation anesthesia. After euthanasia, parasites in the intestine were also counted. As a result; levamisole coming through uncontrolled border trade from Iran was 69.3% effective against A. tetraptera and the levamisole prepared in Turkey was 91.7% effective in naturally infected mice. Results obtained from this study compared statistically and the differences were found to be significant (p < 0.001).  (+info)

The use of cross-foster rederivation to eliminate murine norovirus, Helicobacter spp., and murine hepatitis virus from a mouse colony. (7/21)

Over 10 mo, 287 mouse litters were cross-fostered by using 1 of 2 paradigms to eliminate murine norovirus (MNV), Helicobacter spp., murine hepatitis virus (MHV), and Syphacia obvelata. Paradigm 1 involved cross-fostering litters at younger than 48 h with no attention to the changing of bedding material. Paradigm 2 involved cross-fostering litters at younger than 24 h from cages in which the bedding material was changed within 24 h before cross-fostering. After cross-foster rederivation, mice were tested for the presence of Helicobacter spp. by means of fecal PCR at 4, 8, and 12 wk. Surrogates also were tested for MNV by use of multiplex fluorometric assay serology at 4 wk and fecal PCR at 12 wk. Surrogate mice were tested for MHV by means of MFIA at 4 wk and for pinworms by perianal tape test and fecal flotation at 4 and 12 wk. Compared with those from paradigm 1, litters from paradigm 2 were less likely to be positive for MHV and Helicobacter spp. The use of cross-foster rederivation alone was unsuccessful for the elimination of Syphacia obvelata. For cross-foster rederivation, we recommend that litters be younger than 24 h and from cages in which the bedding material was changed within 24 h before cross-fostering. The presence of MNV, Helicobacter spp., and MHV can be predicted reliably at 12, 8, and 4 wk, respectively.  (+info)

Syphacia sp. (Nematoda: Oxyuridae) in coprolites of Kerodon rupestris Wied, 1820 (Rodentia: Caviidae) from 5,300 years BP in northeastern Brazil. (8/21)

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