Of the common causes for exudative pleural effusions, parapneumonic effusions have the highest diagnostic priority. Even in the face of antibiotic therapy, infected pleural effusions can rapidly coagulate and organize to form fibrous peels that might require surgical decortication.
Retrogradation is the landward change in position of the front of a river delta with time.etrogradation is the landward change in position of the front of a river delta with time.
Retrolisthesis is a misalignment of the spine in which one vertebra slips backward in relation to the vertebrae above and/or below it.Although it may occur anywhere along the spine, retrolisthesis is most commonly seen in the cervical and lumbar regions.tair-stepped retrolisthesis is a condition in which one vertebra is displaced behind the one above it but in front of the vertebra below it. In complete retrolisthesis, the affected vertebra is positioned backward in relation to those vertebrae above and below it.