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.
Retrograde spondylolisthesis, or retrolisthesis, is the condition or problem that results when one vertebra (spinal bone) slips backward in relation to the vertebra that is below it. This is a rather rare and unusual problem compared to the more common antegrade spondylolisthsis.ypically and traditionally the term spondylolisthesis by definition means the forward slippage of one vertebra in relation to the one below it, but the additional term antergrade is added to clarify the direction of abnormal movement because of the occasional occurrence of backward movement.