( ( The patient ) ( now ( ( has ( ( ( ( ( ( two ( thyroid glands ) ) , ) ( ( both ( of which ) ) ( appear ( to work ) ) ) ) , ) and ) ( eight ( parathyroid glands ) ) ) ) . ) ) )
(ROOT (S (NP (DT The) (NN patient)) (ADVP (RB now)) (VP (VBZ has) (NP (NP (NP (CD two) (NN thyroid) (NNS glands)) (, ,) (SBAR (WHNP (DT both) (WHPP (IN of) (WHNP (WDT which)))) (S (VP (VBP appear) (S (VP (TO to) (VP (VB work)))))))) (, ,) (CC and) (NP (CD eight) (JJ parathyroid) (NNS glands)))) (. .)))
The patient now has two thyroid glands, both of which appear to work, and  eight parathyroid glands.
(ROOT (S (NP (DT The) (CD two) (JJ parathyroid) (NNS glands)) (VP (VBP are) (VP (VBN located) (PP (IN behind) (NP (DT the) (NN thyroid) (NN gland))))) (. .)))