COX isozymes and non-uniform neoangiogenesis: What is their role in endometriosis?

This literature review compared the efficacy in of NSAIDs with a placebo in pain relief and disease regression of endometriosis. Despite the poor evidence found, the results showed that NSAIDs were more effective in pain relief with regressive effects on the endometriotic lesions compared to placebo. We postulate herein that COX-2 is chiefly responsible for pain whilst COX-1 is responsible mainly for the establishment of endometriotic lesions. Hence, there must be a temporal difference in the activation of the two isozymes. We differentiated between two pathways in the conversion of arachidonic acid to prostaglandins by the COX isozymes referred to as 'direct' and indirect', supporting our initial theory. Finally, we postulate that there are two stages of neoangiogenesis in the formation of endometriotic lesions; 'founding' that first establishes blood supply and 'maintenance' that upkeeps it. This is fertile ground for further research in a niche that needs more literature. Its aspects may be diversely explored. The theories we propose offer information for a more targeted treatment of endometriosis.

From Platelet-Rich Plasma to Advanced Platelet-Rich Fibrin: Biological Achievements and Clinical Advances in Modern Surgery.

In the past 20 years, the platelet concentrates have evolved from first-generation products, i.e., platelet-rich plasma (PRP) and plasma rich in growth factors to the second-generation products such as leukocyte-platelet-rich fibrin (L-PRF) and advanced platelet-rich fibrin (A-PRF). These autologous products with a higher leukocyte inclusion and flexible fibrin mesh act as a scaffold to increase cellular migration in the angiogenic, osteogenic, and antimicrobial potential of these biomaterials in tissue regeneration. In the second-generation platelet concentrates, the protocols are easier, cheaper, and faster with an entire physiological fibrin matrix, resulting in a tridimensional mesh, not as rigid as one of the first generations. This allows the slow release of molecules over a longer period of time and triggers the healing and regenerative process at the site of injury. The potential of A-PRF to mimic the physiology and immunology of wound healing is also due to the high concentration of growth factors released as follows: vascular endothelial growth factor, platelet-derived growth factor, transforming growth factor-ß, and anti-inflammatory cytokines that stimulate tissue cicatrization, vessels formation, and bone cell proliferation and differentiation. Furthermore, the number of neutrophils and monocytes/macrophages is higher releasing important chemotactic molecules such as chemokine ligand-5 and eotaxin. Thus, L-PRF and A-PRF have been used, especially in implantology, periodontology, and maxillofacial surgery. Future clinical applications include tissue regeneration/grafts, ulcers/skin necrosis in the diabetic patient and others, plastic surgery, and even musculoskeletal lesions.