Parasitism and contraceptives: a preliminary survey of the effect on haemoglobin levels.

PIP: The incidence of parasitic infection among 3 groups of women using different types of contraceptive devices in Ibadan has been compared with that among women who have never used any of these devices and a group of male subjects. The results are correlated with the mean hemoglobin (P.C.V.) levels for all groups. A low level was observed among the groups on IUDs and orals as well as the female control; while the group on injectables and the male control group showed normal P.C.V. levels. Although multiple infection predominated, this was generally of low intensity. Malaria was the only anemia-inducing infection which occurred with any significant variation between all the groups compared. Analysis of the incidence of infection against hemoglobin genotypes revealed no predisposition to any particular infection. The rse of infection was not deterred in the presence of contraceptives; rather, the resutls showed that it might be enhanced.^ieng

Early developmental changes of the schistosomula of Schistosoma mansoni in vitro and in mouse lung.

Fresh (3 h) schistosomula of Schistosoma mansoni were obtained by the skin penetration method and injected intravenously into groups of mice either immediately or after 48 h incubation in tissue culture. Schistosomula were then recovered from the lungs 1 to 2 days after injection. The recovery results showed that the ability of uncultured schistosomula to emerge from lung tissue increased with time, became maximal on the 3rd day and diminished thereafter. In contrast, cultured schistosomula were able to emerge from chopped lung at a much earlier time after injection. Fresh schistosomula, as well as those recovered from mouse lungs, were assayed by indirect immunofluorescence for the presence of parasite and host antigens. Similarly, fresh schistosomula which had been incubated in foetal calf serum, with or without mouse red blood cells, were assayed for parasite and host antigens after 3-24 h of culture. Fresh schistosomula expressed parasite antigen with greater intensity than those recovered from mouse lungs and showed no trace of host antigen. Lung schistosomula, on the other hand, expressed less parasite antigen but more red blood cell antigen with increasing time in the host. Schistosomula cultured in the absence of mouse red blood cells expressed only parasite antigen throughout the period in culture, while those cultured in the presence of mouse red blood cells also expressed parasite antigen during the entire period in culture but, in addition, by 24 h host antigen could also be detected. These developmental and adaptational changes may play a role in determining the survival of parasites in the normal or immune host.

Tissue eosinophil proliferation and maturation in schistosome-infected mice and hamsters.

Extramedullary eosinophilopoiesis is described as a regular pathological feature of murine and cricetine schistosome infections. Using the Dominici staining technique, colonies of developing eosinophils were commonly found in certain tissue sites of dense oviposition, particularly in the liver, and in associated lymphoreticular tissues. The relationship of these observations to the role of eosinophilic leukocytes in schistosomiasis is discussed.