Determination and correlation of in vitro viability for hairless mouse and human neonatal whole skin and stratum corneum/epidermis.

BACKGROUND AND DESIGN: Viable tissue is essential to assess the rate and extent of biotransformation during percutaneous absorption in vitro. We assessed the viability of hairless mouse whole skin (WS) and stratum corneum/epidermis (SCE) and human neonatal SCE following separation from the dermis by EDTA phosphate-buffered saline (EDTA-PBS) incubation or by heat treatment by measuring the conversion of dextrose to lactate. Lactate concentrations in receptor fluid samples were determined using a Sigma diagnostic lactate determination kit. A standard curve was prepared and samples assayed spectrophotometrically at 340 nm using a lambda 2 beta spectrophotometer. Standard curves were prepared for each experiment and correlation coefficient values (r) were calculated. RESULTS: Our results showed that hairless mouse SCE was associated with glucose conversion to lactic acid at an increased rate if incubated in EDTA-PBS for 4 h and used immediately. Lactate production was greater with the dermis present (EDTA-PBS WS). The rate of glucose to lactate conversion in hairless mouse SCE was 20-25% of that found in WS. Compared with Dulbecco's modified PBS (DMPBS)-treated WS controls, the rate of lactate production in EDTA-PBS-treated WS was nearly a 50% less. Heat treatment in water at 60 degrees C to separate SCE from hairless mouse WS appeared to eliminate viability. Viability of hairless mouse SCE, as measured by glucose conversion to lactate, was comparable to human neonatal SCE. CONCLUSIONS: These results suggest that the dermis is a significant contributor to glucose metabolism and that incubation in EDTA-PBS is a contributing factor to the overall decrease in metabolic capacity of the tissue. As a result of these findings, hairless mouse SCE appears to be useful as a model for human neonatal SCE in percutaneous absorption studies.

Cephalic pyoderma gangrenosum (PG)-like lesions as a presenting sign of Wegener's granulomatosis.

BACKGROUND: Pyoderma gangrenosum (PG)-like lesions can be associated with Wegener's granulomatosis (WG); in rare instances, they could be the presenting sign of WG. The purpose of this study was to elucidate the relationship between these two disorders. METHODS: The clinical and histologic data from a case of WG with primary ulcerative lesions of the face were compared with five other cases previously reported in the literature. RESULTS: A predominance among young men was noted. In three patients the histology of the skin ulcerations was suggestive of WG, in the remaining three, including the case described, it was nonspecific. Two cases developed pulmonary WG after the skin lesions cleared, showing that the extent and severity of skin lesions do not necessarily correlate with the systemic disease. CONCLUSIONS: When the histology of the skin is nonspecific, the diagnosis of PG or PG-like lesions of the head and neck should not be considered definitive and the patients should be carefully monitored to rule out the possible presence of WG.

Evaluation of transdermal theophylline pharmacokinetics in neonates.

Theophylline may be administered by several routes, but problems are associated with neonatal dosing. The transdermal route may provide a safer and noninvasive method of administration, yet produce therapeutic concentrations in a consistent and reliable manner. To study the feasibility of this in the apnea of prematurity, stable neonates were administered a subtherapeutic transdermal dose for 24 hours in order to assess pharmacokinetics and bioavailability. This was followed with routine intravenous theophylline therapy according to institutional policy. Six of nine neonates had detectable serum theophylline concentrations that increased slowly after patch application. Mean (+/- SD) maximum serum concentration was 2.4 +/- 1.3 micrograms/ml, mean time to maximum serum concentration was 22 +/- 8.2 hours, and mean latency period was 8.0 +/- 4.9 hours. Mean total amount of theophylline delivered to the skin was 18.6 +/- 4.1 mg. Mean fractional absorption at 30 hours was 0.25 +/- 0.12. These data demonstrate that it is possible to produce systemic theophylline concentrations with a transdermal patch in preterm infants sufficient to study pharmacokinetics and bioavailability, and that transdermal delivery of therapeutic doses is technologically feasible.

Lipoid proteinosis: case report.

A 20-month-old Kuwaiti girl had manifestations of lipoid proteinosis, a rare autosomal recessive disorder seen more commonly in Caucasians. This condition is diagnosed based on clinical, histopathologic, and ultrastructural criteria. Its biochemical and genetic aspects are still poorly understood.

Superficial granulomatous pyoderma.

Superficial granulomatous pyoderma, recently described as a variant of pyoderma gangrenosum, would be better termed pathergic granulomatous cutaneous ulceration as the seven previously described cases, as well as our own two cases, have significant dermal involvement histologically and heal with scarring. In contrast to pyoderma gangrenosum, lesions of superficial granulomatous pyoderma respond to less toxic anti-inflammatory agents.

Structural hair abnormalities in ectodermal dysplasia.

The hair of patients with three ectodermal dysplasias--ectrodactyly ectodermal dysplasia clefting syndrome (EEC); orofacial-digital syndrome (OFD) type I; and anhidrotic ectodermal dysplasia syndrome (AED)--were studied by scanning electron microscopy. While no pathognomonic abnormalities were noted for each condition, hair shaft structural defects were evident in all patients studied. The EEC clefting syndrome and OFD I shared the most deforming defects, while AED had fewer.

Pigmentary regression in a giant nevocellular nevus: a case report and a review of the subject.

A giant congenital nevocytic nevus (CNN) on the trunk was followed in a patient from age three months to 23-years-old. During that time the nevus underwent pigmentary regression leaving 2-3 mm lentigines without any evidence of vitiligo or halo formation around the giant CNN. Histopathologically, nevus cells remained in the dermis.

Percutaneous absorption in preterm infants.

The skin of preterm infants varies considerably in its level of maturity. To understand skin absorption in premature infants better, we report a technique for the assessment of percutaneous absorption at various gestational and postnatal ages using stable, isotope-labeled (13C6) benzoic acid. Our results indicate that in the preterm infant, this method detects enhanced skin absorption in the first postnatal days, which declines over three weeks to that expected of a full-term infant. This approach also indicates an inverse relationship between gestational age and skin absorption, as well as postnatal age and skin absorption. The reported technique is a safe and noninvasive method using a model skin penetrant for the study of percutaneous absorption in preterm infants from which basic data may be derived to add to our understanding of skin barrier function.

The ectodermal dysplasias.

In order to be considered an ectodermal dysplasia, a disorder should meet the following criteria: it must be congenital; it must be diffuse (not localized) and must involve the epidermis as well as at least one of its appendages; and it must not be progressive. Included is a discussion of some well-documented, as well as some newer, conditions about which there appears to exist enough information to make some decisions concerning their categorization.

Cutaneous T-lymphocyte lymphoma in association with multiple myeloma.

We report a case of cutaneous T-lymphocyte lymphoma in which multiple myeloma, a B-lymphocyte neoplasm, developed. We also review the emerging evidence on the immunoregulatory capacity of neoplastic T lymphocytes. Our case clinically supports the notion that neoplastic T lymphocytes may sometimes express helper activity for a specific B-lymphocyte clone (idiotype-specific helper function).

Benign neonatal eruptive hemangiomatosis in identical twins.

Two cases of neonatal hemangiomatosis occurred in identical twins. Work-up for internal hemangiomas were performed on both infants and were negative. Twin no. 1, with extensive lesions, is currently taking oral prednisone, 2 mg/kg/day, with gradual resolution of the lesions. So far, no new hemangiomas have developed in twin no. 2.

Effect of acupuncture on experimentally induced itch.

We evaluated the effect of acupuncture on histamine-induced itch and flare in healthy volunteers (n = 25) and compared it with the effect of a pseudo-acupuncture procedure and of no-intervention in a single-blind randomized cross-over study. A cumulative itch index is defined and was found to be smaller with acupuncture than with either pseudo-acupuncture (p less than 0.02) or with no-intervention (p less than 0.005). The duration of itching was shorter with acupuncture than with either pseudo-acupuncture (p = 0.006) or with no-intervention (p less than 0.001). In addition, maximal flare area was decreased with acupuncture compared with pseudo-acupuncture (p less than 0.04) and with no intervention (p = 0.003). Acupuncture had little or no effect on the itch onset time or on the maximal itch intensity after intradermal injection of histamine. Measurements of itching correlated poorly with measurements of flare size in all three experimental groups. Acupuncture appears to be an effective inhibitor of histamine-induced itch and flare. Moreover, acupuncture points displayed specificity in that needling near-by, non-acupuncture sites resulted in greater itching and larger flares.

Eosinophilic pustular folliculitis in infancy.

Five infants under 1 year of age were reported with a syndrome of recurrent crops of pruritic papulopustules of the scalp. In three children there were also intermittent outbreaks on the trunk and extremities. Cultures showed the pustules to be sterile. Biopsies of scalp and skin tissues showed eosinophilic folliculitis. Some patients had eosinophilia during outbreaks of pustules. These cases are similar to the eosinophilic pustular folliculitis reported in a few adult patients with the exception that there was predominant scalp involvement in the children. We propose that eosinophilic pustular folliculitis of infancy is a distinct pustular dermatosis.