https://www.selleckchem.com/products/SB-203580.html Platelet-rich plasma (PRP) provides a treatment option for female pattern hair loss (FPHL). However, the most suitable preparation method is not yet clear. The primary aim is to compare between the efficacy of single- versus double-spin PRP preparation injection in the treatment of FPHL, while the secondary aim is to assess the relationship between vascular endothelial growth factor (VEGF) concentrations in different prepared PRP preparations (pre- and post-activation) and the obtained treatment results. 15 female patients with FPHL were subjected to intradermal injection of double-spin prepared PRP into the right (Rt) half of the scalp and single-spin prepared PRP into the left (Lt) half of the scalp, three sessions, 3 weeks apart. Evaluation of treatment response was done through comparing patients' photographs, patients' satisfaction and trichoscopic assessment (measurement of terminal hair density) before and after treatment. In addition, VEGF concentration was measured in different PRP samples before and after activation with calcium gluconate. Results showed clinical improvement in both sides of scalp 6 weeks after last PRP session. Meanwhile, Rt median terminal hair density measured by trichoscan following treatment was significantly higher compared to Lt median terminal hair density. Furthermore, VEGF concentration did not differ significantly in single- versus double-spin prepared PRP, or upon calcium activation. PRP is effective in treatment of FPHL. Double-spin method could yield better results than single-spin method. Adding calcium gluconate prior to PRP injection is of no value.Paragangliomas are neuroendocrine tumors of the autonomic nervous system that are variably clinically functional and have a potential for metastasis. Up to 40% occur in the setting of a hereditary syndrome, most commonly due to germline mutations in succinate dehydrogenase (SDHx) genes. Immunohistochemically, paragangliomas are