Long-term priority effects among insects and fungi colonizing decaying wood.

1. Priority effects have been hypothesized to have long-lasting impact on community structure in natural ecosystems. Long-term studies of priority effects in natural ecosystems are however sparse, especially in terrestrial ecosystems. 2. Wood decay is a slow process involving a high diversity of insect and fungus species. Species interactions that drive change in communities of insects and fungi during wood decay are poorly understood because of a lack of sufficient long-term studies. 3. In this paper, we followed the colonization and succession of wood-living insects and fungi on cut trees during 15 years, from tree death and onwards, in a boreal forest landscape. We test the long-term priority effects hypothesis that the identity and abundance of species that colonize first affect the colonization success of later-arriving species. We also hypothesize that species interact in both facilitative and inhibitory ways, which ultimately affect habitat quality for a red-listed late-succession beetle species. 4. Possible causal associations between species were explored by path analysis. The results indicate that one bark beetle species, Hylurgops palliatus, and one wood-borer species, Monochamus sutor, which colonized the wood during the first year after cutting, influenced the occurrence of a rare, wood-living beetle, Peltis grossa, that started to emerge from the stumps about 10 years later. The positive effects of Hylurgops palliatus and negative effects of M. sutor were largely mediated through the wood-decaying fungus species Fomitopsis pinicola. 5. The study shows that variable priority effects may have long-lasting impact on community assembly in decaying wood. The study also exemplifies new possibilities for managing populations of threatened species by exploring links between early, well-understood species guilds and late, more poorly understood species guilds.

Safety and efficacy of outpatient treatment with CPT-11 plus bolus folinic acid/5-fluorouracil as first-line chemotherapy for metastatic colorectal cancer.

The combination of irinotecan (CPT-11), bolus 5-fluorouracil (5-FU) and folinic acid (FA) (Saltz regimen) has recently been questioned as first-line chemotherapy for metastatic colorectal cancer after high early death rates due to gastrointestinal and thromboembolic events were reported in two US trials. Therefore, we carefully evaluated the safety and efficacy of this regimen, with high value placed on the management of delayed diarrhea. Forty-six patients with metastatic colorectal cancer received this first-line treatment in nine German outpatient clinics. Dose reductions were mandatory from the first cycle in case of toxicity grade >2. Chemotherapy was administered only to diarrhea-free patients. During a total of 175 cycles administered treatments were delayed for 1 week in 11.6% and given at a reduced dose in 14.5%. All and 40 patients were evaluable for toxicity and response, respectively. Grade 3/4 toxicities included diarrhea (n=10), leukopenia (n=9), neutropenia (n=3) and anemia (n=4). One non-fatal pulmonary embolism occurred. Four complete responses (CR) and 10 partial responses were seen, for an overall response rate of 35%. In addition, 16 patients (40%) had stable disease. Resectability of liver metastases was achieved in three patients, including one pathologically confirmed CR. Median progression-free and overall survival were 5 and 13 months, respectively. We conclude that outpatient treatment with the Saltz regimen was well tolerated. Severe gastrointestinal toxicity and thromboembolic events were rarely observed and never fatal. As down-staging was possible, combinations of CPT-11 and FA/5-FU should be further investigated in neoadjuvant protocols.