Keratinocyte growth factor (KGF) is a member of the fibroblast growth factor (FGF) family (hence the alternative designation FGF-7). It is produced by stromal cells, but acts as a mitogen for epithelial cells. We examined the effects of topically applied KGF on healing of wounds in a porcine model. In partial-thickness wounds, KGF stimulated the rate of reepithelialization (p < 0.0002), associated with a thickening of the epidermis (p < 0.0001). Epidermis from KGF-treated full-thickness wound sites was significantly thicker (0.31 +/- 0.22 mm) compared with mirror image control sites (0.18 +/- 0.12 mm) (p < 0.0001). Moreover, the majority (77%) of KGF-treated wounds exhibited epidermis with a deep rete ridge pattern as compared with control sites. These effects were observed as early as 14 d and persisted for at least 4 wk. KGF treatment also increased the number of serrated basal cells associated with increased deposition of collagen fibers in the superficial dermis adjacent to the acanthotic epidermis. Electron microscopy revealed better developed hemidesmosomes associated with thicker bundles of tonofilaments in the serrated cells. The pattern of epidermal thickening observed in KGF-treated wounds resembled psoriasis. Psoriasis is a disease associated with epidermal thickening, parakeratosis as well as hyperproliferation that extends beyond the basal layer. In striking contrast to psoriasis, KGF-treated wounds exhibited normal orthokeratotic maturation, and proliferation was localized to the basal cells. Our present findings have significant implications concerning the role of KGF as a paracrine modulator of epidermal proliferation and differentiation.

To demonstrate by SEM the topography and cytoarchitecture of the different parenchymal components of human salivary glands, we have employed a number of techniques that allow either the exposure of internal and lateral cell surfaces or, following the removal of connective tissue, the visualization of endpieces, ducts, and myoepithelial cells. Serous glands consist of indented acini attached to the ducts in a grape-like fashion, whereas mucous and mixed glands are made up of smooth tubuli. Myoepithelial cells (mecs), which are abundant on the surfaces of acini, tubuli, and intercalated ducts, are sparse on striated ducts. They are star-shaped on acini, striated ducts, and most of the tubuli. Spindle-shaped mecs are seen, instead, on intercalated ducts and, occasionally, on mucous and mixed tubuli as well. Cells of striated ducts split into a number of large basal portions whose surface is covered by long laminated processes responsible for the striations seen with TEM. Excretory ducts are lined by small cup-shaped basal cells and by tall cylindrical cells, which are completely covered by short processes oriented at random. When observed from below, after removal of the basal lamina, the basal surfaces of cells of excretory ducts exhibit polygonal areas delimited by short reliefs. Those of striated ducts show, instead, long laminar processes arranged radially. Results presented here are discussed and put in relationship to the mechanism of saliva production.

Amiodarone may induce hyper- or hypothyroidism. Patients with beta-Thalassemia Major (beta-Thal) have an increased prevalence of primary hypothyroidism and often require amiodarone for hemosyderotic cardiomyopathy. Aim of this study was to retrospectively evaluate thyroid function in beta-Thal adult patients on long-term amiodarone. The study group consisted of twenty-two (21 males, 1 female; age: 23-36 yr) beta-Thal patients submitted to long-term (3-48 months) amiodarone therapy from January 1991 to July 1996. Controls included 73 beta-Thal patients (23 males and 50 females aged 25-35 yr) not treated with amiodarone. In all cases serum free thyroid hormones, thyrotropin and thyroid autoantibodies were evaluated. A higher prevalence of overt hypothyroidism (5/22 [22.7%]) as compared to controls (3/73 [4.1%], p=0.02) was found in beta-Thal patients < or = 3 months after starting amiodarone, while the prevalence of subclinical hypothyroidism was similar in amiodarone-treated (18.2%) and untreated (15%) beta-Thal patients. Overt hypothyroidism resolved spontaneously after amiodarone withdrawal in 1 case, while the remaining patients were maintained euthyroid on amiodarone by L-thyroxine administration. After 21-47 months of amiodarone therapy, 3 patients (13.6%) developed thyrotoxicosis (2 overt and 1 subclinical), which remitted shortly after amiodarone withdrawal. No case of hyperthyroidism was observed in beta-Thal controls (p=0.012 vs amiodarone-treated patients). In conclusion, amiodarone administration is often associated in adult beta-Thal patients to a rapid progression of the pre-existing subclinical hypothyroidism, but transient thyrotoxicosis may also be observed after a longer period of therapy. These findings should be carefully considered in the management of these patients.

The purpose of the study is to document the prevalence of articular surface osteochondrosis lesions in feral horses. Eighty yearling feral horses were used. Radiographic images of the left stifle, both tarsocrural, metatarsophalangeal, metacarpophalangeal joints were taken. Radiographs were examined for the presence of osteochondral fragmentation and abnormal outline of subchondral bone suggestive of osteochondrosis. The prevalence of each lesion was calculated for each joint as well as for overall prevalence within the group, the latter being 6.25%. Typical osteochondrosis lesions were found within the tarsocrural and metatarsophalangeal joints. Based on the difference in prevalence of osteochondrosis between feral and certain domestic horses, management practices and perhaps genetic base may have a greater influence on the development of the disease in horses than trauma alone.

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