Multiple geographic origins of commensalism and complex dispersal history of Black Rats.

The Black Rat (Rattus rattus) spread out of Asia to become one of the world's worst agricultural and urban pests, and a reservoir or vector of numerous zoonotic diseases, including the devastating plague. Despite the global scale and inestimable cost of their impacts on both human livelihoods and natural ecosystems, little is known of the global genetic diversity of Black Rats, the timing and directions of their historical dispersals, and the risks associated with contemporary movements. We surveyed mitochondrial DNA of Black Rats collected across their global range as a first step towards obtaining an historical genetic perspective on this socioeconomically important group of rodents. We found a strong phylogeographic pattern with well-differentiated lineages of Black Rats native to South Asia, the Himalayan region, southern Indochina, and northern Indochina to East Asia, and a diversification that probably commenced in the early Middle Pleistocene. We also identified two other currently recognised species of Rattus as potential derivatives of a paraphyletic R. rattus. Three of the four phylogenetic lineage units within R. rattus show clear genetic signatures of major population expansion in prehistoric times, and the distribution of particular haplogroups mirrors archaeologically and historically documented patterns of human dispersal and trade. Commensalism clearly arose multiple times in R. rattus and in widely separated geographic regions, and this may account for apparent regionalism in their associated pathogens. Our findings represent an important step towards deeper understanding the complex and influential relationship that has developed between Black Rats and humans, and invite a thorough re-examination of host-pathogen associations among Black Rats.

A randomized phase III trial of biochemotherapy versus interferon-alpha-2b for adjuvant therapy in patients at high risk for melanoma recurrence.

The objective of this study was to compare the clinical benefit of biochemotherapy and interferon-alpha-2b (IFN) as adjuvant therapy. Biochemotherapy has higher response rates than other regimens in patients with metastatic melanoma. We conducted a randomized phase III study comparing the clinical benefit of biochemotherapy and IFN as adjuvant therapy. Patients who had undergone lymphadenectomy for melanoma metastatic to regional lymph nodes were randomly assigned to either biochemotherapy or IFN, and IFN patients were further randomized to either high-dose IFN (HDI) or intermediate-dose IFN (IDI). The primary end point was relapse-free survival (RFS); the secondary end point was overall survival (OS). The planned enrollment was 200 patients, the number required to have 80% power to detect, at a significance level of 5%, an improvement in median RFS from 18 to 36 months and an improvement in median OS from 40 to 80 months between the IFN and biochemotherapy groups. A futility analysis was performed because of slow accrual. One hundred and thirty-eight patients were enrolled - 71 in the biochemotherapy group, 34 in the HDI subgroup, and 33 in the IDI subgroup. No significant differences in median RFS or OS between the HDI and IDI subgroups were observed. With a median follow-up of 49.3 months, neither the biochemotherapy nor IFN group had reached median RFS or OS, and there were no significant differences in estimated median RFS or OS (P=0.86 and 0.45, respectively) between the two groups. Biochemotherapy is not more effective than IFN as adjuvant therapy for melanoma. These findings support early termination of this trial.

Phase I study of the combination of docetaxel, temozolomide and cisplatin in patients with metastatic melanoma.

PURPOSE: In a search for more effective combination chemotherapy for the treatment of metastatic melanoma, we conducted a phase I trial of a novel combination of docetaxel, temozolomide, and cisplatin. METHODS: Patients with inoperable or recurrent metastatic melanoma with a Zubrod performance status of 2 or less and adequate organ function were eligible. The dose of docetaxel was escalated between cohorts of patients, and the doses of temozolomide and cisplatin were fixed. A standard 3 + 3 dose escalation design was used to determine the maximum tolerated dose (MTD). RESULTS: Among 23 patients who were enrolled, 21 were evaluable for toxicity. Eighteen patients (78%) had stage IV-M1c disease. The dose-limiting toxicities were myelosuppression and pulmonary embolism. The MTD was 30 mg/m(2) docetaxel on days 1, 8, and 15 when given with 150 mg/m(2) temozolomide on days 1-5, and 20 mg/m(2) cisplatin on days 1-4, repeating every 4 weeks. Among 19 patients evaluated for response, 6 (32%) had partial responses and 5 (26%) had stable disease. Among 14 chemo-naive patients, 6 (43%) had a partial response and 4 (29%) had stable disease. Nine patients developed brain metastases by the time of the last follow-up evaluation, and the median time to brain metastases for all 19 evaluable patients has not been reached. CONCLUSIONS: This combination was well tolerated and appears to be a promising treatment for patient with metastatic melanoma.