Convergent evolution of pain-inducing defensive venom components in spitting cobras.

Convergent evolution provides insights into the selective drivers underlying evolutionary change. Snake venoms, with a direct genetic basis and clearly defined functional phenotype, provide a model system for exploring the repeated evolution of adaptations. While snakes use venom primarily for predation, and venom composition often reflects diet specificity, three lineages of cobras have independently evolved the ability to spit venom at adversaries. Using gene, protein, and functional analyses, we show that the three spitting lineages possess venoms characterized by an up-regulation of phospholipase A2 (PLA2) toxins, which potentiate the action of preexisting venom cytotoxins to activate mammalian sensory neurons and cause enhanced pain. These repeated independent changes provide a fascinating example of convergent evolution across multiple phenotypic levels driven by selection for defense.

Teaching and assessing communication skills in Maastricht: the first twenty years.

In order to share the issues involved in setting up a communication skills training programme in a medical school, the development of such a programme at the Skillslab of Maastricht Medical School, the Netherlands, is described and the problems encountered are addressed. A multidisciplinary working group developed teaching goals for communication skills, focused on observable behaviour to be displayed by students. These teaching goals were incorporated in a generic model for doctor-patient communication. A longitudinal training programme was created, throughout the four years of the preclinical curriculum. Students meet in small groups of 10, once every 2 weeks. In between group sessions they practise consultation skills in simulated patient contacts. Communication skills are assessed in the annual multiple station examination. In the development of this programme the following consecutive actions were taken: teaching material was produced, and an assessment tool was developed, as were instruments for programme evaluation. The programme evaluation allowed student feedback to teachers, the teachers' departments, and the administration of the medical school. Finally, teacher training was professionalized.

Reliability and feasibility of measuring medical interviewing skills: the revised Maastricht History-Taking and Advice Checklist.

Medical interviewing skills are integral to good medical care. In order to measure these skills an instrument has been developed, called the Maastricht History-Taking and Advice Checklist (MAAS). It has been studied with regard to interrater reliability and validity. In this study a revised version of the MAAS (MAAS-R), a check-list of concrete interview behaviour, has been investigated concerning feasibility and reliability for examination purposes. Audio-recordings were obtained of 24 doctors, each interviewing eight different standardized patients. The recordings were independently scored by three general practitioners trained in using the MAAS-R. The results of generalizability analysis, considering the influences of doctors, cases and raters, are encouraging. In order to overcome case-specificity feasible and reliable measurement can be accomplished with 8-10 cases in 2-21/2 hours of testing time, each case being scored by a different rater. Reliability improves considerably if assessment is restricted to basic interviewing skills.