The quinone pigment blepharismin isolated from Blepharisma killed other ciliates Paramecium caudatum when it was activated by light. We demonstrated by using electron spin resonance (ESR) spectrometry that light-activated blepharismin generated hydroxyl radicals (-OH). The result suggests that photodynamic action of the pigment may be attributed to hydroxyl radicals.

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As recently reported, a strong stimulation of noninfected CD4⁺-positive H9^- cells by Sarcocystis gigantea (Syn. S. ovifelis) extract (SGE) was observed using the lymphocyte proliferation assay. After SGE-prestimulation, HIV-infected H9⁺ cells showed an exacerbation of the virus replication. In the present study, we investigated the reactivity of HⅣ-infected human monocytes by SGE. The highly sensitive p24 core profile ELISA was used to examine directly the amount of HⅣ produced. Experiments were performed using the permanent monocytic cells U937. Permanent incubation as well as preincubation with SGE before virus infection were able to stimulate HIV expression in all the cells. In U937 cells, the virus release per cell was 64 times higher in permanent stimulation with 320μg SGE compared to controls and 9 times higher in case of prestimulation.

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Two sets of polymerase chain reaction primers that amplify DNA fragments of Cryptosporidium parvum or C. muris were constructed by adapting a simple method, namely cloning and sequencing of randomly amplified polymorphic DNA (RAPD) of corresponding species. The primers successfully amplified genomic DNA of C. parvum or C. muris as well as sample DNA obtained from feces of a human patient, naturally infected cattle or experimentally infected mice. And we also developed the method to obtain DNA of Cryptosporidium from the oocysts in feces.

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Intestinal ciliate compositions in fecal samples from zoo-kept Asian and African elephants were examined. As a result, eleven new species belonging to the genus Triplumaria were recognized. Four of the new species possess both honeycomb-like thick skeletal plates and broad linear skeletons, like T.hamertonii Hoare, 1937 and T. selenica Latteur et al., 1970 known up to this time, and resemble the latter species in anterior location of micronuclei. However, T. longinucleata n. sp. and T. nucleocaudata n. sp possess long macronuclei, with posterior ends curved ventrally or straight and extending into the tail lobe, respectively; T. asiatica n. sp. has two bulb-like and one cylindrical caudalia; and hill-like caudalia of T. heterofasciculata n. sp. are clearly characteristic in size. Six new species possess thin light skeletal plate and slender linear skeleton showing vertebra-like structure, respectively; T. antis n. sp. is small in body size and has a micronucleus in the center of macronucleus, whereas the other species have micronuclei located anteriorly; T. doliiformis n. sp. is characterized by anteriorly hooked macronucleus; T. acuticaudata n. sp. has a triangular tail lobe; T. dvoinosi n. sp. possesses antero-dorsal and ventral caudalia directed up and downward. Antero-dorsal caudalium of T. ovina n. sp. and ventral caudalium of T. irregularis n. sp. are shifted upward and to the left, respectively. The other new species, T. poljanskii n. sp. is characterized by a combination of heavy honeycomb-like skeletal plate and vertebra-like linear skeleton as well as posterior location of the micronucleus.

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A cross-reacting mab B1C4 was obtained by fusion of x63-Ag 8.653 plasmacyioma cells with splenocytes. In the immunoblot of sporozoite proteins separated by SDS-PAGE, by mab B1C4 recognized protein bands at 94, 66, 60, 45, and 20 kDa. Antigens recognized by mab B1C4 were localized in rhoptries and nuclei of sporozoites as shown by immunoelectron microscopy, but also in nuclei of uninfected PCK cells as shown by IFAT. Before cell invasion B1C4 Iabelled granular structures in the apical poles and in the medial cytoplasmic region of sporozoites, stage I merozoites and stage II merozoites. 24 hrs after infection B1C4 labeled a net-like connection between the intracellular sporozoite and the host cell nucleus which was obviously enlarged in infected cells.

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