1 Biomedical Research Unit, Zurita & Zurita Laboratories, Avenida de la Prensa N49-221, 170511 Quito, Ecuador. Electronic address: jzurita@zuritalaboratorios.com.
2 Hospital Luis Vernaza, Loja 700, 090313 Guayaquil, Ecuador.
3 Biomedical Research Unit, Zurita & Zurita Laboratories, Avenida de la Prensa N49-221, 170511 Quito, Ecuador.