@article{plotnikoff_miller_nimeh_wybran_1987,  title={Methionine enkephalin: immunomodulator in normal volunteers, cancer and AIDS patients},  volume={82},  ISSN={0074-0276},  url={https://doi.org/10.1590/S0074-02761987000600011},  DOI={10.1590/S0074-02761987000600011},  journal={Memórias do Instituto Oswaldo Cruz},  publisher={Instituto Oswaldo Cruz, Ministério da Saúde},  author={Plotnikoff, Nicholas P. and Miller, Gerald C. and Nimeh, Nadim F. and Wybran, Joseph},  year={1987},  pages={67–73} }