The distribution of CY2PC19*2 allele in a Trinidadian population. Is Clopidogrel the right choice?

OBJECTIVE: To determine the distribution of the CYP2C19*2 allele among Trinidadians. DESIGN AND METHODS: This is a cross sectional study among 100 patients attending primary health centers within the North Central Region of Trinidad. A stratified sampling technique was used in which there were three mutually exclusive subgroups: those of South Asian descent (Indo-Trinidadians), African descent (Afro-Trinidadians) and mixed ethnicity. Subsequently, systematic sampling was applied to each stratum to improve the representativeness of the sample. Hence, the 100 subjects recruited for the study were 40 Indo-Trinidadians, 40 Afro-Trinidadians and 20 of mixed descent. Apart from baseline data which included age, gender and ethnicity, DNA was assessed for the CYP2C19*2 allelic variant using a PCR method. RESULTS: There was a high allelic frequency (37%) for CYP2C19*2 which was found to be more common among Indo-Trinidadians (47.5%, 95% CI 32.0-63.0) compared to Afro-Trinidadians (22.5%, 95% CI 9.6-35.4) or people of mixed origin (45%, 95% CI 23.2-66.8). There was a significant difference (p=0.019) between CYP2C19*2 frequencies for Indo-Trinidadians and Afro-Trinidadians. CONCLUSION: We provided evidence that the prevalence of CYP2C19*2 mutation was high in our setting.

Maximising somersault rotation in tumbling.

Performing complex somersaulting skills during the flight phase of tumbling requires the generation of linear and angular momenta during the approach and takeoff phases. This paper investigates how approach characteristics and takeoff technique affect performance with a view to maximising somersault rotation in tumbling. A five-segment planar simulation model, customised to an elite gymnast, was used to produce a simulation which closely matched a recorded performance of a double layout somersault by the elite gymnast. Three optimisations were carried out to maximise somersault rotation with different sets of initial conditions. Using the same initial linear and angular momentum as the double layout somersault and varying the joint torque activation timings allowed a double straight somersault to be performed with 19% more rotation potential than the actual performance. Increasing the approach velocity to a realistic maximum of 7 ms(-1) resulted in a 42% reduction in rotation potential when the activation timings were unchanged but allowed a triple layout somersault to be performed with an increase of 31% in rotation potential when activation timings were re-optimised. Increasing also the initial angular momentum to a realistic maximum resulted in a 4% reduction in rotation potential when the activation timings were unchanged but allowed a triple straight somersault to be performed with a further increase of 9% in rotation potential when activation timings were re-optimised. It is concluded that the limiting factor to maximising somersault rotation is the ability to generate high linear and angular velocities during the approach phase coupled with the ability to adopt consonant activation timings during the takeoff phase.