Temporal recording of mammalian development and precancer.

Temporal ordering of cellular events offers fundamental insights into biological phenomena. Although this is traditionally achieved through continuous direct observations, an alternative solution leverages irreversible genetic changes, such as naturally occurring mutations, to create indelible marks that enables retrospective temporal ordering. Using a multipurpose, single-cell CRISPR platform, we developed a molecular clock approach to record the timing of cellular events and clonality in vivo, with incorporation of cell state and lineage information.

Temporal recording of mammalian development and precancer.

Key to understanding many biological phenomena is knowing the temporal ordering of cellular events, which often require continuous direct observations [1, 2]. An alternative solution involves the utilization of irreversible genetic changes, such as naturally occurring mutations, to create indelible markers that enables retrospective temporal ordering [3-8]. Using NSC-seq, a newly designed and validated multi-purpose single-cell CRISPR platform, we developed a molecular clock approach to record the timing of cellular events and clonality , while incorporating assigned cell state and lineage information.

Return to play after anterior cruciate ligament reconstruction in National Football League athletes.

Background: Rupture of the anterior cruciate ligament (ACL) is a common and potentially career-threatening injury in the National Football League (NFL). The return to play (RTP) percentage and the factors affecting RTP after ACL reconstruction in NFL players are not well defined.

Purpose: To determine the actual rate of return to professional football play in the NFL after ACL reconstruction surgery and to determine what factors can predict ability to RTP.

Delayed presentation of cervical ligamentous instability without radiologic evidence.

Study Design: A case of delayed presentation of unstable cervical ligamentous injury without radiologic evidence is presented.

Objectives: To report a rare case of delayed presentation of cervical ligamentous injury without radiologic evidence, and to discuss diagnosis, initial management, and techniques of operative stabilization.

Summary Of Background Data: The literature is reviewed.