Due to the long time course required to achieve steady state with highly lipophilic contaminants such as PCBs (polychlorinated biphenyls), data derived from short-term toxicity tests may lead to an erroneous interpretation of hazard. In addition, PCBs bioaccumulated over time can cause sublethal impairments in organisms at concentrations much lower than required for mortality. Here, the body residues of 1,1-dichloro-2,2-bis-p-chlorophenyl ethane (DDE) and select PCB congeners associated with a spectrum of chronic effects in the midge, Chironomus riparius, were evaluated. The route of exposure was ingestion of the PCB-contaminated alga, Chlorella vulgarus, and trout chow loaded with the selected test compound. Two separate exposures of midges were performed. In the first experiment, midges were exposed from the second instar to the pupal stage. In the second exposure, midges were exposed from the second instar to the adult stage. A variety of sublethal endpoints was monitored, including developmental time within a stadium, body weight, and fecundity for the female adult. The dose was assessed as the whole body residue concentration of the contaminant. Overall, the midge concentration increased with increasing exposure concentration in algae and trout chow. Body weight at the end of each stadium was the assessment parameter that was least significantly affected among the test endpoints monitored. In contrast, a significant increase in development time was the endpoint that was most frequently observed in response to contaminant exposure. Reduction in fecundity was found only for DDE-exposed midges. These data, in which chronic endpoints are related to body residues, suggest that body residues will be useful in defining sublethal hazards of DDE and some PCB congeners.
Using the state-of-the-art digital imaging technology, extended block adjustment, orthorectification and mosaicking, individual Declassified Intelligence Satellite Argon photographic images are precisely assembled into a map quality mosaic of coastal Antarctica. The geometric accuracy of the mosaic is estimated to be approximately equivalent to the original resolution of the Argon photography, which is about 140 m. We compare the Argon mosaic with later satellite images to investigate changes in ice sheet geographic features and dynamical glaciological processes.
16037 Background: Recent evidence suggests gemcitabine combined with a platinum drug is active in recurrent ovarian cancer. In an effort to decrease dose-limiting myelosuppression associated with gemcitabine plus carboplatin, cisplatin can be substituted for carboplatin. Our objective is to describe a single institutional experience with day 1 and day 15 (D1/15) gemcitabine (1000 mg/m2) and cisplatin (30 mg/m2) for the treatment of recurrent ovarian cancer. Methods: A retrospective chart review was performed of all patients with recurrent epithelial ovarian, fallopian tube, and primary peritoneal cancer who were treated with gemcitabine and cisplatin from 8/2001 through 8/2006 at a single institution. Sixty-seven patients met inclusion criteria. Results: The median number of prior chemotherapy regimens was 2 (range 1–6). The median platinum-free treatment interval was 10 months (range 0–40). While 34 (51%) patients were platinum sensitive, 24 (36%) patients were platinum resistant, and 9 patients (13%) were platinum refractory. Patients were treated with a median of 6 cycles (range 1–31) of gemcitabine plus cisplatin. Fifteen (22%) patients had a complete clinical response with a median progression free survival (PFS) of 16 months (range 5–40); 15 (22%) patients had a partial clinical response (median PFS 6 months, range 2–15). Stable disease was noted in 19 patients, with a median PFS of 24 months (range 4–36). Three (38%) out of eight patients with refractory ovarian cancer had a complete clinical response, and 1 patient had a partial response. Non-hematologic toxicities were most common, occurring in 23% of the patient population (neuropathy, fatigue and pain). Grade 3 and 4 hematologic toxicities were rare, occurring in less than 10% of patients. Conclusions: Gemcitabine plus cisplatin (D1/15) is a well tolerated and active regimen in patients with recurrent ovarian cancer, regardless of previous response to platinum-based chemotherapy. No significant financial relationships to disclose.
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