Evidence of altered epidermal nerve fiber morphology in adults with self-injurious behavior and neurodevelopmental disorders

The purpose of this preliminary study was to examine the morphology and neuropeptide density of epidermal nerve fibers quantified through skin biopsy samples from three adults with neurodevelopmental disorders and chronic self-injurious behavior (SIB) secondary to mental retardation compared with non-SIB normal IQ controls. A cross-sectional design was used with 3 mm punch skin biopsies collected from each participant from non-self-injurious body sites and compared with site-matched existing normal control skin samples. The study was conducted at an outpatient clinic. The primary dependent measure for the morphology analyses was the coefficient of variation (CV) to quantify the mean gap length between epidermal nerve fibers for each subject. Visual microscopic examination and quantitative analysis of the microscopy images suggested there were morphological abnormalities (increased CV) in the epidermal nerve fibers among the chronic SIB cases. Substance P (SP) fiber density was increased with 2 to 3 times as many fibers in SIB subjects as control subjects. Additional empirical work is needed to clarify the relation between sensory innervation of the skin and self-injury to improve assessment and treatment outcomes

A Device to Quantify Sweat in Single Sweat Glands to Diagnose Neuropathy

We devised an objective "Sensitive Sweat Test" (SST) that detects and quantifies early changes in the function of sudomotor nerves that activate sweat glands (SGs). The SST is designed to diagnose peripheral neuropathy early, when the probability for reversal is greatest. Chemotherapy induced and diabetic neuropathy are very common causes of neuropathy in the USA. Both result in peripheral numbness, pain, decreased sweating, abnormal circulation, and eventual weakness. Early recognition can provide a better opportunity to treat and halt neuropathy than discovery after the onset of nerve degeneration. We contend that early diagnosis can be achieved by sensitive monitoring of sweating. Unfortunately, the changes that first signal impending sweat deficiency escape detection by conventional clinical examination and current tests We contracted with several MN small business concerns (SBCs) to construct the SST miniature camera device Methods Skin sites on the medial calf and foot dorsum, each measuring 2 cm 2 were stimulated to sweat maximally by iontophoresis of 1% pilocarpine (2 ma, 5 min; Transparent tape thinly coated with starch was attached over the lens of the SST miniature camera. The skin test sites were prepped with a 1% iodine solution. The skin was wiped dry and immediately the camera was pressed against the skin, activating a switch to begin image collection and storage. As sweat water exited from each sweat pore it contacted iodine and starch and formed a tiny dark spot. The tape prevented formation of a drop. Instead, sweat was forced to flow centrifugally to form a flat expanding dark spot. The SST device imaged spots from >200 SGs at 1 frame/sec (area of 2 cm 2 ) for 60 to 90 seconds, until adjacent spots coalesced. The process was performed twice. Image analysis was done in the Mathworks Software, MATLAB version R2012a. Each individual sweat spot was identified and followed from frame to fram

Rebuild, restore, reinnervate: do human tissue engineered dermo-epidermal skin analogs attract host nerve fibers for innervation?

PURPOSE: Tissue engineered skin substitutes are a promising tool to cover large skin defects, but little is known about reinnervation of transplants. In this experimental study, we analyzed the ingrowth of host peripheral nerve fibers into human tissue engineered dermo-epidermal skin substitutes in a rat model. Using varying cell types in the epidermal compartment, we wanted to assess the influence of epidermal cell types on reinnervation of the substitute. METHODS: We isolated keratinocytes, melanocytes, fibroblasts, and eccrine sweat gland cells from human skin biopsies. After expansion, epidermal cells were seeded on human dermal fibroblast-containing collagen type I hydrogels as follows: (1) keratinocytes only, (2) keratinocytes with melanocytes, (3) sweat gland cells. These substitutes were transplanted into full-thickness skin wounds on the back of immuno-incompetent rats and were analyzed after 3 and 8 weeks. Histological sections were examined with regard to myelinated and unmyelinated nerve fiber ingrowth using markers such as PGP9.5, NF-200, and NF-145. RESULTS: After 3 weeks, the skin substitutes of all three epidermal cell variants showed no neuronal ingrowth from the host into the transplant. After 8 weeks, we could detect an innervation of all three types of skin substitutes. However, the nerve fibers were restricted to the dermal compartment and we could not find any unmyelinated fibers in the epidermis. Furthermore, there was no distinct difference between the constructs resulting from the different cell types used to generate an epidermis. CONCLUSION: Our human tissue engineered dermo-epidermal skin substitutes demonstrate a host-derived innervation of the dermal compartment as early as 8 weeks after transplantation. Thus, our substitutes apparently have the capacity to attract nerve fibers from adjacent host tissues, which also grow into grafts and thereby potentially restore skin sensitivity

Ascorbate-induced fibroblast cell matrix: reaction of antibodies to procollagen I and III and fibronectin in an axial periodic fashion.

Fibronectin and procollagen types I and III are constituents of the extracellular matrix of human fibroblasts. Ultrastructural immunocytochemistry using the peroxidase anti-peroxidase method showed fibronectin and procollagen antibodies reacting in continuous fashion on 10 nm diameter extracellular fibrils on human fibroblasts. Intracellular localization showed an intense accumulation of procollagen within cells cultured under routine conditions. This accumulation appeared almost as if there were a blockade in secretion of procollagen under routine culture conditions. Cells treated with ascorbic acid do not have the dense intracellular accumulation of procollagens seen with the apparent blockade of secretion in cells cultured under routine conditions. Ascorbate treated cells also have a more pronounced extracellular accumulation of matrix fibronectin and procollagen constituents. At the electromicroscopic level a new 40 nm diameter fibril is formed after ascorbic acid treatment of human fibroblasts. Antibody to fibronectin and procollagen I and III are seen binding to the 40 nm diameter fibrils in a periodic or stuttered appearance. The fibronectin and procollagen antibodies react with a 70 nm axial repeat along these 40 nm fibrils formed after ascorbate treatment. These studies suggest that under routine culture conditions "precursor" fibrils of fibronectin and procollagen are formed. Ascorbic acid treatment leads to enhanced matrix formation. Ultrastructural studies clearly show antibodies to fibronectin bind to fibronectin on native collagen fibrils formed by human fibroblasts cultured with ascrobic acid. Lastly there is an asymmetric or 70 nm axial periodic distribution of fibronectin along these definitive or mature collagen fibrils formed after ascorbic acid treatment

Reversal by glucocorticoid hormones of the loss of a fibronectin and probollagen matrix around transformed human cells.

Confluent cultured human skin fibroblasts had an extracellular fibrillar matrix of fibronectin and procollagen. Human skin fibroblasts transformed by SV40 did not have such a matrix. Treatment of transformed fibroblasts with 10(-5) to 10(-8) M dexamethasone and 10(-5) to 10(-7) M cortisol, but not testosterone or progesterone, caused partial restoration of the matrix. Glucocorticoid-treated transformed human fibroblasts can serve as a model for partial reversion toward normal or differentiation of transformed human fibroblasts