Design, synthesis and activity against Toxoplasma gondii, Plasmodium spp., and Mycobacterium tuberculosis of new 6-fluoroquinolones.

This paper reports on the rational design of a series of new 6-fluoroquinolones by QSAR analysis against Toxoplasma (T.) gondii, their synthesis, their biological evaluation against T. gondii and Plasmodium (P.

Detection of Cryptosporidium, Giardia and Enterocytozoon bieneusi in surface water, including recreational areas: a one-year prospective study.

Accidental ingestion of natural waters while bathing carries a risk of infection by waterborne protozoa such as Cryptosporidium, Giardia and, possibly, microsporidia. In order to evaluate this risk, we conducted a one-year prospective study of two recreational lakes and three river sites located near Paris, where bathing and boating are frequent. Twenty-litre water samples were collected monthly from each site.

Inhibitory activity of human immunodeficiency virus aspartyl protease inhibitors against Encephalitozoon intestinalis evaluated by cell culture-quantitative PCR assay.

Immune reconstitution might not be the only factor contributing to the low prevalence of microsporidiosis in human immunodeficiency virus (HIV)-infected patients treated with protease inhibitors, as these drugs may exert a direct inhibitory effect against fungi and protozoa. In this study, we developed a cell culture-quantitative PCR assay to quantify Encephalitozoon intestinalis growth in U-373-MG human glioblastoma cells and used this assay to evaluate the activities of six HIV aspartyl protease inhibitors against E. intestinalis.

Synthesis of new fluoroquinolones and evaluation of their in vitro activity on Toxoplasma gondii and Plasmodium spp.

The synthesis of four new computer-designed fluoroquinolones which have been predicted by QSAR analysis to be active against the protozoa Toxoplasma gondii is described. These compounds are inhibitory in vitro for T. gondii.

Detection of Microsporidia, cryptosporidia and Giardia in swimming pools: a one-year prospective study.

In order to estimate the rate of microsporidia, cryptosporidia and giardia contamination of swimming pools, sequential samples of water were collected during a one-year period in six different swimming pools in Paris, France. Fourty-eight samples were submitted to filtrations. Eluates were examined for microsporidia using polymerase chain reaction (PCR) and for cryptosporidia and giardia using immunofluorescence staining.

Effects of chemical and physical agents on viability and infectivity of Encephalitozoon intestinalis determined by cell culture and flow cytometry.

We combined tissue culture and flow cytometry to assess the activities of various temperatures, chemicals, and disinfectants on the viability and infectivity of spores of Encephalitozoon intestinalis. Surfanios and benzalkonium chloride, disinfectants currently used in the hospital, were remarkably efficient in destroying spore viability and infectivity.

Detection of microsporidia in surface water: a one-year follow-up study.

In order to estimate the rate and seasonal variation of Enterocytozoon bieneusi contamination of surface water, sequential samples of water from the River Seine in France were collected during a 1-year period. Each sample (300-600 l) was submitted to sequential filtrations, and the filters were then examined for microsporidia using light microscopy and nested polymerase chain reaction (PCR) for E. bieneusi.

Anti-toxoplasma activities of antiretroviral drugs and interactions with pyrimethamine and sulfadiazine in vitro.

The anti-Toxoplasma activities of nine antiretroviral drugs were examined in vitro. Nucleoside analogs had no effect on parasite growth, whereas ritonavir and nelfinavir were inhibitory for Toxoplasma, with 50% inhibitory concentrations of 5.4 and 4.

Anti-Toxoplasma activity of vegetal extracts used in West African traditional medicine.

Both Toxoplasma gondii and Plasmodium are Apicomplexan protozoa that share common metabolic pathways and potential drug targets. The objective of this study was to examine the anti-Toxoplasma activity of nine West African plants with known activity against P. falciparum.

Inhibition of the in vitro infectivity and cytopathic effect of human foamy virus by dideoxynucleosides.

Human foamy virus (HFV) is a human retrovirus that has not been clearly associated with human disease. In this study, we tested the capacity of nucleoside derivatives to inhibit the infectivity and cytopathic effect of HFV in T-lymphoblastoid cells in vitro. H9 cells showed a dramatic cytopathic effect 3 weeks after exposure to HFV.

Transient immunosuppressive effect induced in rabbits and mice by the human spumaretrovirus prototype HFV (human foamy virus).

Spumaviruses (foamy viruses) constitute one of the three retroviral genera isolated from man. Although spumaviruses have not been clearly linked to a given pathology in humans and other infected species, it is well established that they lead in vivo to chronic infections without detectable viral expression. We thought it of interest to investigate certain aspects of the pathology induced in laboratory animals by human foamy virus (HFV).

Further characterization of the gapped DNA intermediates of human spumavirus: evidence for a dual initiation of plus-strand DNA synthesis.

We recently reported the presence of linear duplex DNA intermediates with a gap in the middle of the molecules in the replicative cycle of human (HSRV) and simian (SFV1) spumaviruses. The polypurine tract (PPT), at the 5' boundary of the 3' long terminal repeat, was found to be duplicated in the gap region. By molecular analysis of HSRV proviral DNA with region- and strand-specific probes, we have now determined that the gap is located on plus-strand DNA and that it is 120 bases long with the 3' end mapping at the duplicated PPT site.

Molecular differences between two immunologically related spumaretroviruses: the human prototype HSRV and the chimpanzee isolate SFV6.

A comparative study at the genomic and protein level was performed between two immunologically related spumaretroviruses, the human HSRV and the simian SFV6. Cross immunoprecipitation analysis with specific polyclonal and monoclonal antisera indicates shared antigenic determinants. However, restriction analysis of the viral DNAs and thermal stability of the hybrids demonstrate that HSRV and SFV6 are two different isolates.

Evidence for a gapped linear duplex DNA intermediate in the replicative cycle of human and simian spumaviruses.

Two forms of linear DNAs have been found in simian (SFV1) and human (HSRV) spumaviruses: a linear duplex unsensitive to nuclease S1 and a sensitive structure with a single-stranded gap. Two nuclease S1 sensitive sites, mapping at the same position for both viruses, have been identified in the gapped structure. Using different molecular subgenomic clones of HSRV as probes in Southern blot analysis, one S1 site was localized in the 3'LTR and the other near the middle of the molecule at about 6.

Studies on in vitro interferon induction capacity and interferon sensitivity of simian foamy viruses.

We demonstrate that Simian Foamy viruses (SFV) types 1, 2, 4 and 10 do not induce Interferon (IFN) production in mouse and primate (simian and human) cell lines, but that their cytopathogenic effect is blocked by this viral inhibitor. The mechanisms of action of IFN seems to be different from that of other Retroviridae. No trapping of virions appears in treated cells examined by ectron microscopy.