Interleukin-4, immunoglobulin E and immunoglobulin A and resistance to re-infection with Schistosoma haematobium before and after chemotherapy.

The role of serum IL-4, IgE and IgA in protective immunity had been determined in 88- S. haematobium infected-individuals before and 3, 6, 9 and 12 months after treatment with a single dose of praziquantel. Before treatment, IL-4 level was found to be highly significant in all stages of infection, there was a positive correlation between IL-4 levels and egg count. Whereas serum IgE and IgA levels were significantly high in late infected group showing a negative correlation with egg count. After praziquantel treatment, IL-4 levels decreased gradually while IgE and IgA levels were significantly increased in all patients. At 9 and 12 months, viable ova were detected in 11 cases (12.5%), they were re-infected after treatment showing an increase in IL-4 levels, and a decrease in both serum IgE and IgA. These results indicate that IL-4 plays an important role in suppression of severe inflammatory responses associate with persistence of the parasitic stages. Also, serum IgE and IgA participate in protective immunity against S. haematobium infection. It may be essential to administer a second dose of praziquantel to all persons living in endemic areas who are likely to be in contact with infested water.

A study on the potential role of Trichomonas vaginalis in transmission of Herpes simplex virus type II.

Some strains of Trichomonas vaginalis have been reported to contain virus-like particles (VLP). Whether they were natural inhabitants or acquired from the host, the emerging question will be about the potential role of this protozoan in viral transmission. The present model have been established for studying the ability of T. vaginalis to acquire Herpes simplex virus type II (HSV). Green monkey kidney cells (Vero cells) were infected with HCV and T. vaginalis was inoculated 3 days later. The progress of virus transmission was monitored by transmission electron microscopy (TEM). Fragments of virus containing Vero cells were engulfed by the trichomonads and internalised in vacuoles followed by resolution of the vacuole boundary and viral particles aggregates were retained. Viable HSV was recovered from the trichomonads for 5 days. A conducting study was done through cytopathological examination of 170 cervicovaginal smears revealed 25.8% having trichomoniasis, 2.9% HSV infection and 1.17% with combined infection, while HSV infections represent 4.5% in those having trichomoniasis. These results suggest the potential role of T. vaginalis in viral transmission to reduce this risk, further studies are recommended.

Evaluation of two cultural media (CPLM & TYM) for isolation and maintenance of Trichomonas vaginalis stocks in the laboratory.

Five hundreds vaginal discharge specimens were inoculated simultaneously in 2 axenic culture media (CPLM & TYM), in order to compare their ability to isolate and to maintain the growth of T. vaginalis in the laboratory. While both media were found to be equally good in detecting the organisms in vaginal discharges, yet, T. vaginalis stocks were maintained for a longer time in TYM medium (one year), than in the CPLM medium (2 weeks). The yields of the parasites with different inocula subcultured and after different incubation periods were counted in the TYM medium.

Protein chromatographic study on adult Ascaris lumbricoides, Ascaris vitulorum and Toxocara canis.

Chromatographic analysis using Sephacryl S-300 was done on protein extract of adult Ascaris lumbricoides, A. vitulorum and Toxocara canis worms. Six fractions were separated from both Ascaris species and nine from T. canis. Fractions revealed a variety of molecular weights in relation to the three species of worms that ranged from 6,000-70,000 daltons. Crude extract of T. canis showed cross reaction with both species of Ascaris sera using double gel diffusion, while no reaction was obtained using a partially purified antigen.

Helminthotoxic capacity of eosinophils in case of eosinophilia.

Helminthotoxic effect of eosinophils on schistosomula of S. mansoni was studied in thirty patients with peripheral eosinophilia of different causes. Ten cases presented with parasitic infections and twenty cases were parasite free. Twenty healthy persons with normal blood picture were tested as a control group. The adherence assay test of eosinophils and the assay of cell mediated damage of eosinophils to schistosomula were used. The percentages of the adherence and the toxic effect of eosinophils were the same for each group. They were 85.1% in the parasitic group, 85.45% in the non parasitic with other causes group and 13.9% in the control group. The difference was statistically highly significant (P less than 0.001).