ABSTRACT
BACKGROUND: Onychomycosis is mainly caused by dermatophytes, but yeasts and nondermatophyte molds have also been implicated, giving rise to diverse clinical presentations. The aetiological agents of the disease may show geographic variation. AIM: The aim of the present study was to isolate the causative pathogens and to correlate the various clinical patterns of onychomycosis with causative pathogens. MATERIALS AND METHODS: The study population comprised 170 patients with clinical suspicion of onychomycosis. Nail samples were collected for direct microscopic examination and culture. Clinical patterns were noted and correlated with causative pathogens. RESULTS: Out of total 170 cases included in the study, 140 (82.4%) were positive by microscopy and 77 (45.3%) showed positive mycological findings by both microscopy and culture. The male: female ratio was 1:2.5 and the mean age was 35.29 ± 16.47 years. Fingernails were involved in 51.9%, toenails in 28.6% and both fingernails and toenails in 19.5% of the 77 patients. The clinical types noted were distal lateral subungual onychomycosis (71.4%), proximal subungual onychomycosis (10.4%), total dystrophic onychomycosis (10.4%), superficial white onychomycosis (3.9%) and mixed pattern onychomycosis (3.9%). Yeasts were the most common pathogens isolated, being found in 36 patients (46.8%) followed by nondermatophyte molds which were isolated from 28 patients (36.4%) followed by dermatophytes which were isolated from 13 patients (16.9%). CONCLUSION: Distal lateral subungual onychomycosis was the most common clinical presentation. Candida albicans, Aspergillus species and Tricophyton rubrum were the major pathogens. A single pathogen can give rise to more than one clinical type.
ABSTRACT
Fate determination of neural crest cells is an essential step for the development of different crest cell derivatives. Peripheral glia development is marked by the choice of the neural crest cells to differentiate along glial lineages. The molecular mechanism underlying fate acquisition is poorly understood. However, recent advances have identified different transcription factors and genes required for the complex instructive signaling process that comprise both local environmental and cell intrinsic cues. Among others, at least the roles of Sox10, Notch, and neuregulin 1 have been documented in both in vivo and in vitro models. Cooperative interactions of such factors appear to be necessary for the switch from multipotent neural crest cells to glial lineage precursors in the peripheral nervous system. This review summarizes recent advances in the understanding of fate determination of neural crest cells into different glia subtypes, together with the potential implications in regenerative medicine.
