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Markus Borner

Publications and source records attributed to Markus Borner.

9 recordsLinked to original sources
PubMed2006

Effective enforcement in a conservation area.

Wildlife within protected areas is under increasing threat from bushmeat and illegal trophy trades, and many argue that enforcement within protected areas is not sufficient to protect wildlife. We examined 50 years of records from Serengeti National Park in Tanzania and calculated the history of illegal harvest and enforcement by park authorities. We show that a precipitous decline in enforcement in 1977 resulted in a large increase in poaching and decline of many species. Conversely, expanded budgets and antipoaching patrols since the mid-1980s have greatly reduced poaching and allowed populations of buffalo, elephants, and rhinoceros to rebuild.

Animals↗
PubMed2005

Phase II study of temsirolimus (CCI-779), a novel inhibitor of mTOR, in heavily pretreated patients with locally advanced or metastatic breast cancer.

PURPOSE: In this study, two doses of temsirolimus (CCI-779), a novel inhibitor of the mammalian target of rapamycin, were evaluated for efficacy, safety, and pharmacokinetics in patients with locally advanced or metastatic breast cancer who had been heavily pretreated. PATIENTS AND METHODS: Patients (n = 109) were randomly assigned to receive 75 or 250 mg of temsirolimus weekly as a 30-minute intravenous infusion. Patients were evaluated for tumor response, time to tumor progression, adverse events, and pharmacokinetics of temsirolimus. RESULTS: Temsirolimus produced an objective response rate of 9.2% (10 partial responses) in the intent-to-treat population. Median time to tumor progression was 12.0 weeks. Efficacy was similar for both dose levels but toxicity was more common with the higher dose level, especially grade 3 or 4 depression (10% of patients at the 250-mg dose level, 0% at the 75-mg dose level). The most common temsirolimus-related adverse events of all grades were mucositis (70%), maculopapular rash (51%), and nausea (43%). The most common, clinically important grade 3 or 4 adverse events were mucositis (9%), leukopenia (7%), hyperglycemia (7%), somnolence (6%), thrombocytopenia (5%), and depression (5%). CONCLUSION: In heavily pretreated patients with locally advanced or metastatic breast cancer, 75 and 250 mg temsirolimus showed antitumor activity and 75 mg temsirolimus showed a generally tolerable safety profile.

Adult↗
PubMed2005

Ecological change, group territoriality, and population dynamics in Serengeti lions.

Territorial behavior is expected to buffer populations against short-term environmental perturbations, but we have found that group living in African lions causes a complex response to long-term ecological change. Despite numerous gradual changes in prey availability and vegetative cover, regional populations of Serengeti lions remained stable for 10- to 20-year periods and only shifted to new equilibria in sudden leaps. Although gradually improving environmental conditions provided sufficient resources to permit the subdivision of preexisting territories, regional lion populations did not expand until short-term conditions supplied enough prey to generate large cohorts of surviving young. The results of a simulation model show that the observed pattern of "saltatory equilibria" results from the lions' grouping behavior.

Algorithms↗
PubMed2005

Irinotecan combined or alternated with bolus 5-fluorouracil and folinic acid versus the Mayo Clinic regimen in the first-line therapy of advanced colorectal cancer.

The objective of this study was to assess the efficacy and safety of two regimens of irinotecan, combined or alternated with bolus 5-fluorouracil (5-FU) and folinic acid (FA), and the Mayo Clinic regimen as first-line therapy for colorectal cancer (CRC). A total of 152 patients with advanced CRC were randomised, and 149 patients were treated intravenously by irinotecan 125 mg/m2, FA 20 mg/m2 followed by 5-FU 500 mg/m2 bolus, weekly for 4 weeks (arm A, Saltz regimen; n=46), or irinotecan 350 mg/m2 alternating with FA 20 mg/m2/day followed by 5-FU bolus 425 mg/m2/day for 5 days (arm B; n=53), or FA 20 mg/m2/ day followed by 5-FU bolus 425 mg/m2/day over 5 days every 4 weeks (arm C, Mayo Clinic regimen; n=50). Patients were analyzed for tumor response, time to progression, overall survival, safety and quality of life. The overall response rate for evaluable patients in arm A was 33% [95% confidence interval (CI), 17-49%], in arm B was 32% (95% CI, 16-49%) and in arm C was 26% (95% CI, 12-40%). Median times to progression were 7.9, 7.0 and 6.9 months and median survival times were 22.2, 17.0 and 18.2 months for arms A, B and C, respectively, in the intention-to-treat population. The main grade 3-4 adverse events were neutropenia (7%, 39% and 12%) and diarrhea (6%, 21% and 18%). In conclusion, both regimens containing irinotecan were active and well tolerated in patients with advanced CRC.

Adult↗
PubMed2003

Combining capecitabine and gemcitabine in patients with advanced pancreatic carcinoma: a phase I/II trial.

PURPOSE: Preclinical studies indicate positive interactions between capecitabine, an oral fluorouracil precursor, and gemcitabine, the current standard treatment for advanced pancreatic carcinoma (APC). In this study, we investigated the addition of capecitabine to gemcitabine treatment for patients with APC. PATIENTS AND METHODS: This multicenter study included patients naïve to chemotherapy who had histologically or cytologically confirmed, nonresectable or metastatic pancreatic carcinoma. Gemcitabine was given at a fixed dose of 1,000 mg/m(2) on days 1 and 8 of a 21-day cycle. Capecitabine was given in increasing doses orally bid for 14 days followed by a 1-week rest. The maximum-tolerated dose (MTD) was defined as one dose level below the dose causing dose-limiting toxicity (DLT) in >or= one third of a cohort of six patients. We included an additional 15 patients at the MTD. RESULTS: Thirty-six patients were included. DLT occurred at a dose of 800 mg/m(2) bid of capecitabine and consisted of myelotoxicity and mucositis. Hand-foot syndrome was not observed, and other toxic effects were mild. Thus, in this regimen, the recommended dose of capecitabine is 650 mg/m(2) bid. In 27 patients with measurable disease, we observed one complete and four partial remissions. In addition, significant drops (> 50% from baseline value) of the tumor marker CA 19-9 occurred in 14 of 24 assessable patients. CONCLUSION: The combination of capecitabine and gemcitabine is well tolerated, with apparent efficacy in patients with APC. Therefore, it is currently being compared with gemcitabine monotherapy in a phase III study.

Aged↗
PubMed2002

Randomized comparative study of tegafur/uracil and oral leucovorin versus parenteral fluorouracil and leucovorin in patients with previously untreated metastatic colorectal cancer.

PURPOSE: This phase III study compared the time to progression (TTP) of an oral regimen of dihydropyrimidine dehydrogenase inhibitory fluoropyrimidine composed of a fixed combination of tegafur and uracil in a 1:4 molar ratio (UFT) and leucovorin (LV) to intravenous (IV) fluorouracil (5-FU) and LV in previously untreated metastatic colorectal carcinoma (CRC) patients. Secondary end points were survival, tumor response, safety, and quality of life. PATIENTS AND METHODS: Between May 1996 and July 1997, 380 patients were randomized to receive either UFT (300 mg/m(2)/d) and LV (90 mg/d), administered for 28 days every 35 days, or 5-FU (425 mg/m(2)/d) and LV (20 mg/m(2)/d), given IV for 5 days every 35 days. RESULTS: No statistically significant difference in TTP was observed between treatments. With 320 events assessed, the median TTP was 3.4 months (95% Confidence interval [CI], 2.6 to 3.8) on UFT/LV and 3.3 months (95% CI, 2.5 to 3.7) on 5-FU/LV (P =.591, stratified log-rank test). There were no statistically significant differences in survival, tumor response, duration of response, and time to response. Substantial safety benefits were observed in patients treated with UFT/LV. They experienced significantly less stomatitis/mucositis (P <.001) and myelosuppression, resulting in fewer episodes of febrile neutropenia (P <.001) and less documented infection (P =.04). Concomitant medication usage was significantly greater on 5-FU/LV (P =.010). With respect to quality of life, after correcting for baseline imbalances, there were no significant differences between treatments for any scale, except diarrhea. CONCLUSION: The oral UFT/LV regimen failed to achieve improved TTP; however, the study confirms significant safety improvements compared with bolus IV 5-FU/LV for the first-line treatment of metastatic CRC.

Administration, Oral↗