Complex sentence: For example, they first noted the association of oxidative stress with the combination of psychosis, dyskinesia, pigmentation abnormalities, and deafness in varous human diseases, proposing an underlying etiology common to both the symptoms and the diseases.
Split into simpler sentences: For example, they noted the common association of oxidative stress with a particular constellation of symptoms in varous human diseases. They further postulated an underlying etiology common to both the symptoms and the diseases.