Complex sentence: He legally fought against the quarantine and following his release, D'Souza resigned his position at the World Wildlife Fund, and with his friend Isabel de Santa Maria Vas founded the HIV/AIDS non-governmental organization, "Positive People" in April 1992.
Split into simpler sentences: He legally fought against the quarantine and, following his release, resigned his position at the World Wildlife Fund. Together with his friend Isabel de Santa Maria Vas, he founded the HIV/AIDS non-governmental organization "Positive People" in April 1992.