<Tr> <Td> PR </Td> <Td> prothrombin ratio </Td> </Tr> <Tr> <Td> p.r. </Td> <Td> per rectum (as noun: rectal examination) </Td> </Tr> <Tr> <Td> PRA </Td> <Td> plasma renin activity </Td> </Tr> <Tr> <Td> PRBC PRBCs </Td> <Td> packed red blood cells </Td> </Tr>

What does pra stand for in medical terms
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