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Biomedical subjects

John Persing

Publications and source records attributed to John Persing.

7 recordsLinked to original sources
PubMed2006

Giant nevi: a review.

Congenital nevi are benign neoplasms that are present at birth and composed of nevomelanocytes. Approximately 1-3% of all newborns have congenital pigmented nevi, and the number of nevi increases with age, peaking by late adolescence to 20-40 nevi in an individual. Giant congenital nevi are often defined as nevi that are greater than 20 cm in diameter in an adult, or nevi that occupy 2% or more of the body surface area. Histologically, nevi are transformed melanocytes, which are normally highly dendritic cells interspersed among basal keratinocytes. The genetic basis of these lesions is not known. Findings of a culture of melanocytes from such a lesion from a showed chromosome rearrangements involving 1p,12q, and 19p. The giant nevi might be associated to several diseases: neurocutaneous melanosis, diffuse lipomatosis, structural brain malformations, hypertrophy of skull bones, limb atrophy, skeletal asymmetry involving both soft tissue hyper-and hypoplasia, von Recklinghausen's disease and vitiligo. The risk of malignant change in giant nevi is probably the most contentious issue in its management. The consensus is that lesions are pre-malignant, but the purported incidence of malignancy varies wildly from 0-42%. Surgical excision remains the mainstay of treatment for large congenital melanocytic nevi, and most giant nevi are managed by staged excision and resurfacing with skin grafts or tissue expanders and flaps.

Humans↗
PubMed2003

Asymmetric skull shapes: diagnostic and therapeutic consideration.

The asymmetric skull shape, or plagiocephaly has become of particular concern since the advent of the "Back to Sleep Campaign," as increasing numbers of children present with this deformity within the first year of life. In this article we review the diagnosis and treatment options for the management of various forms of plagiocephaly. Of particular concern are the various forms of craniosynostosis which may be mistaken for deformational plagiocephaly.

Craniosynostoses↗
PubMed2003

Prevention and management of positional skull deformities in infants. American Academy of Pediatrics Committee on Practice and Ambulatory Medicine, Section on Plastic Surgery and Section on Neurological Surgery.

Cranial asymmetry may be present at birth or may develop during the first few months of life. Over the past several years, pediatricians have seen an increase in the number of children with cranial asymmetry, particularly unilateral flattening of the occiput. This increase likely is attributable to parents following the American Academy of Pediatrics "Back to Sleep" positioning recommendations aimed at decreasing the risk of sudden infant death syndrome. Although associated with some risk of deformational plagiocephaly, healthy young infants should be placed down for sleep on their backs. This practice has been associated with a dramatic decrease in the incidence of sudden infant death syndrome. Pediatricians need to be able to properly diagnose skull deformities, educate parents on methods to proactively decrease the likelihood of the development of occipital flattening, initiate appropriate management, and make referrals when necessary. This report provides guidelines for the prevention, diagnosis, and management of positional skull deformity in an otherwise normal infant without evidence of associated anomalies, syndromes, or spinal disease.

Female↗
PubMed2002

The soft triangle revisited.

Five cadaveric adult human noses were examined to further elucidate the region of the soft triangle of the nose. Three distinct zones were found. Zone 1, just caudad to the lower lateral cartilages, consists of the fibers of the dilator nares anterior as it inserts into the dermis. Zone 2 is the dermal layer. Zone 3 is at the nostril rim and consists of muscle fibers interdigitating within the dermis; laterally, these fibers are continuations of the nasalis muscle, whereas medially they are extensions of the depressor septii muscle. Perpendicular incisions through any of these zones may cause notching and tip deformity. Incisions in zone 1 may, in addition, alter external nasal valve function by interrupting the fibers of the dilator naris anterior.

Adult↗
PubMed2002

Anatomy of the Caucasian alar groove.

Anatomic studies performed on the noses of 15 cadavers examined the alar groove, alar lobule, and lower lateral crus areas both microscopically and on gross appearance to determine what effect these structures have on overall nasal appearance. In contrast to the findings of previous studies, the authors found the alar lobule to be an area in which dermis is interdigitated with muscle throughout and up to the alar rim. The anteroposterior lengths of the lower lateral crura were again seen to vary in length, presence or absence of accessory cartilages, and shape. Neither corrugation of the posterior elongation nor overlap of the accessory cartilages of the lower lateral cartilage had an effect on phenotype; sharp angles formed by the cartilage were blunted by the layer of fibrofatty muscular tissue between the cartilage and the skin. The alar groove, which lies at the junction of the lower lateral crus (medially) and the alar lobule (laterally), is defined not as much by a muscular attachment between the perichondrium of the lower lateral cartilage and the vestibular mucosa as by a bulging in the fatty layer on one side of the groove (within the cheek, lateral nasal wall, and nasal tip) and a relative paucity of fatty tissue on its other side (within the alar lobule).

Cartilage↗