Chronic rejection remains the major obstacle to long-term allograft survival.
A main obstacle in chronic hepatitis B, however, is the high load of viral antigens expressed and secreted, which has been proposed to cause antigen-specific immune tolerance.
Despite the potential of rapamycin both clinically and as an anti-aging therapeutic, the risk of new onset type 2 diabetes or other metabolic diseases is a significant obstacle for chronic use of rapamycin in humans.
65 Perhaps as a result of the reduced phagocytic capacity of immune cells at the chronic wound, one consistent obstacle in the healing of many chronic wounds is a build-up of necrotic debris at the wound edge; as a consequence it is often clinical practice to debride the wound mechanically, to establish a 'fresh new' wound, which can help to restart the re-epithelialization process.
The physiologist Hans Selye, called the father of stress research, identified "good" stress — the adrenaline rush that helps people overcome obstacles — and "chronic" stress, which may easily turn into distress.
At the same time, those and other chronic conditions face particular obstacles that are either intrinsic to their natural history or severity, or to the lack of a perception that access to care for them should be a right for which the State is to be held accountable.
But even if that presidential seal of approval were real, it would not overcome a chronic and serious public health obstacle: Most men do not like condoms.
However, the development of resistance to interferon therapy is a major obstacle in curing chronic HCV infection.
Patients emphasize the strategic importance of the patient physician relationship in their satisfaction with knee OA management, the necessary flexibility of this relationship, and the risk of the "routinization" of management in chronic clinical situations being an obstacle to the adaptation of this management to the specificities of the patient's profile.
Armed conflicts that kill and injure children are proliferating and chronic poverty remains the greatest obstacle to fulfilling the rights of children.
Chronic fatigue, sleep deprivation and the resulting stress are all major obstacles to productivity.
