Sylvain Guichard

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The enemy release hypothesis posits that the initial success of invasive species depends on the scarcity and poor adaptation of native natural enemies such as predators and parasitoids. As for parasitoids, invading hosts are first attacked at low rates by a species-poor complex of mainly generalist species. Over the years, however, parasitoid richness may(More)
CPT-11 is a prodrug activated by carboxylesterases to the active metabolite SN-38 which is a potent inhibitor of topoisomerase I. CPT-11 is of clinical interest in the treatment of colorectal cancer. We evaluated the activities of CPT-11 converting carboxylesterase (CPT-CE) and topoisomerase I (topo I) in 53 colorectal tumours, in eight liver metastases and(More)
Although first-line chemotherapy induces complete clinical remission in many cases of epithelial ovarian cancer, relapse usually occurs 18-28 months from diagnosis owing to micrometastases. The present study aimed to evaluate the effect of trastuzumab on disease-free and overall survival in a specially designed murine model of ovarian cancer (OVCAR-3),(More)
We modelled the ecoclimatic niche of Culicoides imicola, a major arthropod vector of midge-borne viral pathogens affecting ruminants and equids, at fine scale and on a global extent, so as to provide insight into current and future risks of disease epizootics, and increase current knowledge of the species' ecology. Based on the known distribution and(More)
Dosages of anticancer drugs are usually calculated on the basis of a uniform standard, the body surface area (BSA). Although many physiological functions are proportionate to BSA, overall drug clearance is only partially related to this parameter. Consequently, following administration of equivalent drug dosages based on BSA, a wide variability in plasma(More)
Irinotecan, a DNA-topoisomerase-I inhibitor, is active against metastatic colon carcinoma. We investigated the effects of irinotecan and 5FU combinations in human colon-carcinoma cell line HT-29, both in vitro and in vivo. Cytotoxicity of 24-hr exposure was evaluated by SRB technique and the nature of interactions were determined by median-effect analysis.(More)
CPT-11 (irinotecan) is a DNA topoisomerase I inhibitor active against metastatic colorectal carcinoma. We investigated, in a human colon carcinoma cell line, HT-29, the effects of CPT-11 and 5-fluorouracil (5FU) combinations. A strong synergism between CPT-11 and 5FU was observed after sequential exposure and only additivity or antagonism after simultaneous(More)
The in vitro and in vivo combination of oxaliplatin and irinotecan was investigated in a panel of four human colon cancer cell lines and their counterpart xenografts. In vitro and in vivo experiments demonstrated a synergistic or additive interaction in three cell lines (HCT-116, HCT-8 and HT-29) and an antagonism in SW-620 cells. Since there were clearly(More)
Topotecan is a topoisomerase (Topo) I inhibitor used in ovarian carcinoma chemotherapy. Topo I inhibitors are thought to be more cytotoxic using protracted schedules of administration. We tested this hypothesis on a preclinical model: human ovarian carcinoma OVCAR-3 implanted i.p. Nude mice were treated i.p. with a total dose of topotecan of 12.5 mg/kg(More)
The horse chestnut leafminer, Cameraria ohridella Deschka & Dimic (Lepidoptera, Gracillariidae) spread over the last 10 years from central Europe to western Europe and was observed for the first time in 2000 in the east of France and near Paris. This study presents the results of surveys carried out in France in 2001 to investigate the distribution and(More)