The main thing that these two horrific incidents show is that African Americans have historically had good reason to distrust doctors and the medical community. The fact that something like the Tuskegee Syphilis Experiment could persist into the 1970s is something that could certainly make African Americans feel that the system is capable of abusing them even today. This may, for example, be one reason why the idea that the government created AIDS to kill African Americans seemed plausible to many from the African American community.
In both of these cases, the government unilaterally and surreptitiously used the medical system to perpetrate what could well be called atrocities on African Americans. The Tuskegee Syphilis Experiment allowed African American men with syphilis to go untreated even as they believed that they were receiving care for the disease. In the case of the “appendectomies,” men and women were forcibly sterilized for eugenic purposes (whites were victimized in this way as well).
What this shows is that African Americans have a good historical reason to be suspicious of government medical programs and of the medical community in general. If such things could be done to them as recently as 40 years ago, it is not unreasonable to be suspicious of the government and the medical community.