The Current View of Retroviruses as Seen from the Shoulders of a Giant

Retroviruses and retrotransposons both insert copies of their genetic elements into the genome of the host cell. Thus, the viral genes are passed on when the host genome is replicated or translated. A typical retroviral DNA sequence contains 3-4 genes that encode the different proteins required for its structural assembly and function as a molecular parasite. This DNA is transcribed into a single mRNA, which is very similar in structure to conventional mRNAs, i.e., it is capped at the 5’...

Reverse total shoulder arthroplasty is indicated for the treatment of conditions that cannot be treated with conventional arthroplasty or other procedures. These primarily include degenerative and incapacitating conditions with irreparable rotator cuff and loss of the normal biomechanical coupling of the shoulder.

Retroviruses have a single-stranded RNA genome that undergoes a special form of replication. Once the retrovirus has entered the host cell, an enzyme called reverse transcriptase synthesizes double-stranded DNA from the retroviral RNA genome. This DNA copy of the genome is then integrated into the host’s genome inside the nucleus via an enzyme called integrase. Consequently, the retroviral genome is transcribed into RNA whenever the host’s genome is transcribed, allowing the...

Source: Robert E. Sallis, MD. Kaiser Permanente, Fontana, California, USA
Examination of the shoulder can be complex, because it actually consists of four separate joints: are the glenohumeral (GH) joint, the acromioclavicular (AC) joint, the sternoclavicular joint, and the scapulothoracic joint. The GH joint is primarily responsible for shoulder motion and is the most mobile joint in the body. It has been likened to a golf ball sitting on a tee and is prone to instability. It is held in place...

Source: Rachel Liu, BAO, MBBCh, Emergency Medicine, Yale School of Medicine, New Haven, Connecticut, USA
The anterior shoulder dislocation is one of the most common joint dislocations seen in emergency settings. In anterior shoulder dislocation, the humeral head is displaced out of the glenohumeral joint in front of the scapular glenoid, resulting in a loss of the articulation between the arm and the rest of the shoulder. This can be caused by a fall onto an abducted, extended, and externally...

The muscles surrounding the shoulder girdle, including the clavicle and scapula, primarily stabilize the scapula. This stable base allows other muscles to move the humerus effectively. Scapular movements often mirror those of the humerus and extend its range of motion. For instance, raising the arm above the head would not be feasible without simultaneous upward rotation of the scapula.
Anterior Thoracic Muscles
The anterior thoracic muscles include the serratus anterior, subclavius, and...