bromochloroacetic-acid and Foot-Ulcer

Diabetic foot is one of the most common long term complications of diabetes. The risk of developing a foot ulcer is significantly increased when a patient presents with a callus. Callus develops due to various reasons, of which, the most important in people with diabetes is peripheral neuropathy. Motor neuropathy leads to deformity and sensory neuropathy causes lack of sensation, which results in persistent abnormal pressure on the foot. The cells of skin react to it by increasing keratinization and turns into a callus, which predisposes to foot ulceration. However, there is a lack of research in the field of callus. The link between hyperkeratosis, insulin and hyperglycaemia is not fully explored. There is also a lack of research on the relationship between genetic defects of hyperkeratosis, and the risk of developing a diabetic foot ulcer. There is scope for further research in this area, such as exploring whether development of callus is an individual risk factor, and whether glycaemic control or its treatment has any relationship with callus formation. The research around the genetic defects of hyperkeratosis may lead to identification of those, with diabetes, who may have increased risk of developing a foot ulcer.

Topics: Bony Callus; Diabetic Foot; Diabetic Neuropathies; Foot Ulcer; Humans; Keratins; Skin; Skin Diseases

Damage to, or deterioration of, the keratinized horn tissue of the bovine hoof claw culminates ultimately in the development of solear ulceration. We have observed abnormal keratin distribution at the site of solear ulceration in the bovine claw that may be due to alteration of the positional cues of the keratinocytes. In this study we have characterized key cell biological changes associated with ulceration in the claw that may precipitate abnormal keratinization. Loss of basement membrane at sites of ulceration was found by immunofluorescent detection of laminin and integrins. In other tissues, basement membrane breakdown results from degradation by matrix metalloproteinases (MMPs). Similarly, elevated levels of MMPs 2 and 9 were observed in ulcerated bovine claw tissue both by zymography and, quantitatively, by assay of enzyme activity. In the sole of claws that contained an ulcer, tissue distal to the ulcer site also had elevated MMP 2 when compared with healthy sole tissue from the same animals, as did sole tissue of claws recovering from ulceration. Tissue inhibitor of metalloproteinase 2 (TIMP 2) was detected by ELISA in healthy tissue. TIMP 2 tended to be lower in diseased tissue distal to ulcer sites, and was significantly lower in ulcerated tissue. MMP 2 was located by immunofluorescence in the dermal and basal epidermal region of sole tissue, in the region of the basement membrane. Increased punctate staining of material in the dermis was associated with ulcerated material. ELISA of TIMP 2 in tissue extracts enriched for dermis or epidermis confirmed that the inhibitor was located predominantly in the dermis. To investigate a possible causal relationship between basement membrane anchorage and epidermal keratinization, the effect of function-blocking antibodies to laminins and integrins was tested in tissue explant cultures prepared from healthy sole tissue. Anti-integrin antibody treatment had no effect on either protein or DNA synthesis. In contrast, in the presence of anti-laminin antibody, protein synthesis was decreased in a concentration-dependent manner, a significant effect being observed at the highest concentration after treatment for 24 h. At this concentration, DNA synthesis was also decreased after 48 h of culture, an effect that may be relevant to a hibernal reduction in claw cell turnover, and the associated seasonal vulnerability of cows to claw damage. The results provide evidence for basement membrane disruption at ulcer sites

Topics: Animals; Basement Membrane; Cattle; Cattle Diseases; Enzyme-Linked Immunosorbent Assay; Fluorescent Antibody Technique; Foot Ulcer; Hoof and Claw; Keratins; Matrix Metalloproteinase 2; Matrix Metalloproteinase 9; Microscopy, Fluorescence; Signal Transduction; Tissue Distribution; Tissue Inhibitor of Metalloproteinase-2

Keratinization of the epidermal cells of the bovine claw generates the horn that gives the tissue its mechanical strength. Disruption of keratinization is likely to have a detrimental effect on the strength and integrity of the horn, and could lead to solar lesions and lameness. As part of a wider investigation of the cell biological causes of lameness in dairy animals, we have compared keratin synthesis and distribution in healthy bovine claw tissue with those in hooves with solar ulcers. Protein synthesis was measured by [35S]-labelled amino acid incorporation in claw tissue explant cultures. [35S]-labelled protein synthesis was higher in tissue from diseased claws than in healthy claws, and highest at the ulcer site. The identity of proteins synthesised in vitro did not differ between healthy and diseased tissue. DNA synthesis indicative of cell proliferation was also elevated in diseased tissue. Immunoblotting after one- or two-dimensional electrophoresis showed cytokeratins (CK) 4, 5/6, 10 and 14 to be amongst those expressed in healthy claw tissue. The relative abundance of these keratins was not altered in healthy regions of ulcerated hooves, nor at the ulcer site, but CK16, not usually found in healthy tissue, was detected in the sole of diseased claws. CK5/6 and CK14 were shown by immunohistochemistry to be present in the basal epidermis of healthy tissue, whereas CK10 was found in supra-basal layers. In healthy tissue from ulcerated claws, this distribution was unaltered, but at the site of solar ulcers, CK5/6 and CK14 were each found in both basal and supra-basal epidermis. The study suggests that solar ulceration of the bovine claw is not associated with gross alteration in the keratin composition of the tissue, but causes abnormal distribution of cytokeratins, perhaps as a result of loss of positional cues from the basement membrane. Ulceration did, however, stimulate cell repair involving epidermal protein synthesis (including keratins), and keratinocyte proliferation.

Topics: Animals; Cattle; Cattle Diseases; Epidermis; Female; Foot Ulcer; Hoof and Claw; Immunohistochemistry; Keratins; Lameness, Animal; Ulcer