RESUMEN
Understanding the evolutionary history of the species in a particular region provides insights into how that fauna was formed. Of particular interest to biogeographers is examining the impact a geographical barrier had in generating temporal genetic diversity among codistributed species. We examined the impact a major New World barrier, the Isthmus of Tehuantepec (IT) in southern Mexico, had on a regional bird fauna. Specifically, genetic data from 10 montane-forest bird taxa were analysed using approximate Bayesian computation (ABC) to test the hypothesis of simultaneous intraspecific diversification at the IT. Because effective population size (N(e)) has the greatest impact on coalescent times, thereby affecting tests of divergence among codistributed taxa, we chose priors for both current and ancestral N(e) using empirical estimates of theta. The ABC method detected two discrete diversification events. Subsequent analysis with the number of diversification events constrained to two suggests that four taxa diverged in an older event, with the remaining six diverging more recently. Application of a range of mutation rates from 2.0 to 5.0% Myr(-1) places both events within the Pleistocene or Late Pliocene, suggesting that fluctuations in montane habitat induced by climate cycles and a late Pliocene seaway may have fractured this montane bird fauna. The results presented here suggest this avian fauna responded in a relatively concerted fashion over the last several million years.
Asunto(s)
Aves/genética , Especiación Genética , Geografía , Aislamiento Social , Animales , Teorema de Bayes , Biodiversidad , Aves/fisiología , Flujo Génico , México , NADH Deshidrogenasa/química , NADH Deshidrogenasa/genética , Filogenia , Densidad de Población , Análisis de Secuencia de ADNRESUMEN
BACKGROUND: Systemic agents in cancer treatment were often associated with possible infusion reactions (IRs). This study estimated the incidence of IRs requiring medical intervention and assessed the clinical and economic impacts of IRs in patients with colorectal cancer (CRC) treated with cetuximab. PATIENTS AND METHODS: Details on patients with CRC receiving cetuximab in 2004-2006 were extracted from a large USA administrative claims database. IRs were identified based on the occurrence of outpatient treatment, emergency room (ER) visit, and/or hospitalization for hypersensitivity and allergic reactions. Multivariate regressions were used to examine potential risk factors and quantify the economic impact of IRs. RESULTS: A total of 1122 CRC patients receiving cetuximab were identified. The incidence of IRs requiring medical intervention was 8.4%. Sixty-eight percent of the patients had treatment disruptions and 34% discontinued cetuximab treatment. Mean adjusted costs were $13,863 for cetuximab administrations with an IR requiring ER visit or hospitalization and $6280 for those with an IR requiring outpatient treatment, compared with $4555 for those without an IR. CONCLUSIONS: The incidence rate of cetuximab-related IRs requiring medical intervention in clinical practice was found to be higher than rates reported in the product label and clinical trials. The clinical and economic impacts of these IRs are substantial.
Asunto(s)
Anticuerpos Monoclonales/uso terapéutico , Antineoplásicos/uso terapéutico , Neoplasias Colorrectales/tratamiento farmacológico , Neoplasias Colorrectales/economía , Análisis Costo-Beneficio , Hipersensibilidad a las Drogas/economía , Infusiones Intravenosas/efectos adversos , Anticuerpos Monoclonales Humanizados , Cetuximab , Hipersensibilidad a las Drogas/diagnóstico , Hipersensibilidad a las Drogas/tratamiento farmacológico , Femenino , Humanos , Incidencia , Masculino , Persona de Mediana Edad , Años de Vida Ajustados por Calidad de Vida , Estudios Retrospectivos , Factores de Riesgo , Tasa de Supervivencia , Resultado del TratamientoRESUMEN
BACKGROUND: Male-pattern hair loss (androgenetic alopecia) is a common clinical condition in adult men that is often associated with negative self-perception and has been the target of a number of therapeutic interventions. Despite the importance of self-perceptions of hair growth and appearance with such interventions, nostandardized valiated questionnaire exists for use in clinical trials. OBJECTIVE: DEvelop and evaluate a questionnaire to measure patients-perceived changes in hair growth and appearance in clinical trials of medical intervention for androgenetic alopecia in emen. METHODS: Literature review and focus groups with men having androgenetic alopecia initially identified 28 potential questions. These questions were assessed in an observational study (n=204) and placebo-controled seven global questions addressing change since the start of the study in satisfaction with hair appearance (three questions), hair growth and appearance, size of the bald spot, and slowing of hair loss. Significant differences favoring active treatment over placebo were evident for all seven questions by months in a clinical trial. CONCLUSIONS: This standardized questionnaire can be used to assess patient perceptions of hair growth in clinical trials of men with androgenetic alopecia