Hello dubaidave and welcome to the Dubai visa forums
There's a new DNRD
office in the Arabian Center
- the new mall that opened in Mizhar a couple of months back. The Arabian Center also has a medical center so is that perhaps the one you're thinking of?
There is a Dubai Health Authority in Al Khawaneej on Khawaneej Road. Tel +971-4-2892092 for more details. Or tel the Dubai Health Authority helpline 800-4991 toll-free in the UAE. The DHA website just says there's a new center "coming soon" for Muhaisnah.
The Dubai residence visa medical test
is a blood test for HIV, hepatitis B & C, leprosy, syphilis, and a chest x-ray for TB (pulmonary tubercolosis). Cost is AED 210-300 (have seen different prices), or more if you want an express service.