therefore, they present clinically with longitudinal melanonychia.7,16 However, up to 25% of subungual melanocytes originate in the nail bed and, in view of the limited melanin synthesis by these melanocytes, they are often amelanotic.2,7,11,14,21 Given their low density and quiescent state, it may be difficult to visualize nail melanocytes with hematoxylin-eosin staining, and an immunohistochemical technique is needed.7,18,20,22 Cytoplasmic staining with melan-A and HMB45 is less precise and may even stain keratinocytes in lesions with a very active pigment synthesis.7,20,23,24 Nuclear stains, such as MiTF and SOX10, are cleaner and can more exactly determine melanocyte density and site in the epithelial layers.7,20,23,24 Nail melanocytes do not stain well with S100 and so its use should be limited.7,9,11,13,16,20 Nail Biopsy Techniques One of the main reasons, if not the main reason, for performing a biopsy of the nail apparatus is to rule out subungual melanoma.7,16,19,25 There are many different techniques and to select the most appropriate we should bear in mind both the need to obtain a usable specimen for study and the technical difficulty and risk of permanent nail dystrophy.2,11,14,16,25 Taking into account that most melanocytic lesions lie in the nail matrix, this structure should be included in almost all cases
The top 5 proteins that were up-regulated most in expression after riboflavin deficiency were H31, RPS29, AK1C2, GSH0 and TRXR1, whereas AOFB, DLD, NQO1, NDUFS1 and DDX11 were the top 5 proteins that were down-regulated most (Table 1)
any such changes are more likely related to weight loss, hormonal shifts, or psychological factors
Or performing them out of order
