Skin benefits from continuous topical administration of a zinc oxide/petrolatum formulation by a novel disposable diaper.

BACKGROUND: Diaper dermatitis is a common childhood affliction. Aiming to help reduce the prevalence of this problem, we have advanced in our development of a novel diaper that delivers dermatological formulations to help protect the skin from over-hydration and irritation. OBJECTIVE: To determine the clinical benefits of a novel disposable diaper designed to deliver a zinc oxide and petrolatum-based formulation continuously to the skin during use. METHODS: All studies were independent, blinded, randomized clinical trials. Study A was conducted to confirm transfer of the zinc oxide/petrolatum (ZnO/Pet) formulation from the diaper to the child's skin during use. Children wore a single diaper for 3 h or multiple diapers for 24 h. After the use period, stratum corneum samples were taken from each child and analysed for ZnO/Pet. Study B evaluated the prevention of skin irritation and barrier damage from a standard skin irritant (SLS) in an adult arm model. Study C evaluated skin erythema and diaper rash in 268 infants over a 4-week usage period. One half of the infants used the ZnO/Pet diaper, while the other half used a control diaper that was identical except for the absence of the ZnO/Pet formulation. RESULTS: The ointment formulation and ZnO transferred effectively from the diaper to the child's skin during product use. Transfer of ZnO increased from 4.2 microg/cm2 at 3 h to > 8 microg/cm2 at 24 h. Exposure to the formulations directly on adult skin prior to an irritant challenge was associated with up to a 3.5 reduction in skin barrier damage and skin erythema. Greatest reductions were seen for the ZnO containing formulations. Wearing of the formulation treated diaper was also associated with a significant reduction in skin erythema and diaper rash compared to the control product. CONCLUSIONS: The results demonstrated the clinical benefits associated with continuous topical administration of a zinc oxide/petrolatum-based formulation by this novel diaper.

Chemoreceptors expressed in taste, olfactory and male reproductive tissues.

We have identified three genes encoding previously uncharacterized chemoreceptors expressed in rat sensory and reproductive tissues using a reverse transcriptase polymerase chain reaction strategy. Degenerate oligonucleotides designed from conserved sequences in the rat olfactory receptor gene family were used to amplify candidate receptor gene products expressed in taste tissue. Sequence analysis of three distinct clonal isolates revealed that the gene products from taste bud were 30-75% identical to previously identified olfactory receptor genes. The genomic coding sequences predicted protein structures with seven membrane spanning regions that have strong conservation relative to other members of the G-protein-coupled olfactory receptor gene family. Transcripts for each of the three gene products were detected exclusively in taste, olfactory and male reproductive tissue. Sequence analysis of the polymerase chain reaction products confirmed that identical transcripts were expressed in all three tissues. These findings are the first demonstration that identical olfactory receptor-like gene are expressed in three distinct tissues.

Rat olfactory cells and a central nervous system neuronal subpopulation share a cell surface antigen.

Using the monoclonal antibody (Mab) 6B7, a cell surface component found in adult rat central nervous system membrane preparations and on the surfaces of a subpopulation of neurons in cultures of embryonic rat forebrain has been identified. This Mab was derived from mice immunized with a rat forebrain synaptic plasma membrane preparation. High levels of Mab 6B7 binding are observed with membrane preparations from rat forebrain and olfactory bulb but no detectable binding is observed with membranes from the non-neural adult rat tissues heart, kidney, liver, lung and testes. Binding to dorsal root ganglia preparations was 5-fold lower than to forebrain. In immunofluorescence analyses, Mab 6B7 binds to the surface of a significant proportion of neurons in cultures of embryonic day 14 rat forebrain. However, it is absent from GFAP-positive astrocytes, oligodendrocytes, Schwann cells and fibroblastic cells in rat neural cultures. Due to the high levels of binding in olfactory tissue, the distribution of the 6B7 antigen in the olfactory epithelium was characterized in greater detail. In cryostat sections, 6B7 appears to react with a cell population of the basal layer of the adult rat epithelium, but is absent from the cell bodies of the more mature neuronal population which lies higher in the epithelium. This result suggests that within the olfactory epithelium Mab 6B7 may be useful as a marker for the proliferative basal cells which are the neuronal precursors in the epithelium. In summary, the 6B7 antigen may be useful in identifying and analyzing cell subpopulations in both the central nervous system and olfactory epithelium.

Polypeptide variation in an N-CAM extracellular immunoglobulin-like fold is developmentally regulated through alternative splicing.

The alternative splicing of a previously undiscovered 30 base exon confers a new level of polypeptide diversity on the N-CAM family of cell-surface glycoproteins. It results in the insertion of 10 amino acids into the fourth of five extracellular immunoglobulin-like folds. Each major size class of rat brain N-CAM mRNAs consists of members that contain or lack the exon. Furthermore, this splicing event is developmentally controlled: RNAs containing the inserted exon are expressed at extremely low levels (less than 3%) in embryonic brain but increase postnatally to 40%-45% of all N-CAM mRNAs in adult brain. Antibodies that recognize the alternative 10 amino acid segment react with a subset of N-CAM-expressing neurons in cultures of embryonic rat cells.