Ulcer Edge Research Articles

The Impact of Differential Expression of Extracellular Matrix Metalloproteinase Inducer, Matrix Metalloproteinase-2, Tissue Inhibitor of Matrix Metalloproteinase-2 and PDGF-AA on the Chronicity of Venous Leg Ulcers

Introduction Alteration in the expression of extracellular matrix metalloproteinase inducer (EMMPRIN), matrix metalloproteinase-2 (MMP-2), tissue inhibitors of matrix metalloproteinases (TIMP-2) and platelet derived growth factor (PDGF-AA) may contribute to poor healing in venous leg ulcers. Aim The aim of this study is to determine the expression of EMMPRIN, MMP-2, TIMP-2 and PDGF-AA in the ulcer exudates and perivascular tissue of healing and non-healing chronic venous ulcers. Patients, materials and methods Forty patients with chronic venous ulcers were included in this study, with a mean age of 60 years. Eleven patients were males and 29 were females. All patients had normal ankle brachial index and a venous ulcer of at least 8 weeks duration. Immuno-histochemistry using monoclonal antibodies to PDGF-AA, MMP-2, TIMP-2 and EMMPRIN was carried out on paraffin embedded punch biopsy skin specimens from the ulcer edge. Enzyme linked immunosorbent assay for PDGF, MMP-2 and TIMP-2 were carried out on wound fluids collected from patients. The ulcer size and character at the initial assessment and after 8 weeks were assessed to determine the status of ulcer healing. Results No significant difference was seen in the expression of TIMP-2, MMP-2 and EMMPRIN between the two groups. However, in the non-healing group high levels of MMP-2 and low levels of TIMP-2 in the wound fluid suggest a strong correlation of these two markers in the state of healing. Analysis of wound fluid by ELISA demonstrated high PDGF-AA in the healing group ( p=0.021). Significantly increased levels of PDGF-AA ( p<0001) was noted in the perivascular area on immuno-histochemistry of healing ulcers. These data suggest that PDGF-AA plays an important role in healing of venous ulcers. Conclusion Non-healing venous ulcers are associated with greater activity MMP-2 activity. The ratio of MMPs to their inhibitors TIMPs, dictate the rate of healing of the ulcers. PDGF-AA activity is associated with ulcer healing, though the mechanism is unclear. EMMPRIN expression in chronic venous ulcers probably parallels the chronicity of the condition rather than propagate it. However, further studies with larger samples are needed.

Molecular Pathogenesis of Chronic Wounds: The Role of β-Catenin and c- myc in the Inhibition of Epithelialization and Wound Healing

Lack of understanding of the molecular mechanisms and pathogenesis of impaired healing in chronic ulcers is a serious health issue that contributes to excessive limb amputations and mortality. Here we show that beta-catenin and its downstream targets in keratinocytes, c-myc, and keratins K6 and K16, play important roles in the development of chronic wounds. In contrast to normal epidermis, we observed a significant nuclear presence of beta-catenin and elevated c-myc expression at the nonhealing wound edge of chronic ulcers from 10 patients. In vitro studies indicated that stabilization of nuclear beta-catenin inhibited wound healing and keratinocyte migration by blocking epidermal growth factor response, inducing c-myc and repressing the K6/K16 keratins (cytoskeletal components important for migration). The molecular mechanism of K6/K16 repression involved beta-catenin and arginine methyltransferase (CARM-1) acting as co-repressors of glucocorticoid receptor monomers. We conclude that activation of the beta-catenin/c-myc pathway(s) contributes to impaired healing by inhibiting keratinocyte migration and altering their differentiation. The presence of activated beta-catenin and c-myc in the epidermis of chronic wounds may serve as a molecular marker of impaired healing and may provide future targets for therapeutic intervention.

Long-term Outcome of Helicobacter pylori–Negative Idiopathic Bleeding Ulcers: A Prospective Cohort Study

Helicobacter pylori-negative idiopathic ulcers are increasingly recognized. The secular trend and long-term outcome of this condition are unknown. We prospectively studied consecutive patients with bleeding gastroduodenal ulcers from January to December 2000. The incidence and etiology of ulcers during this period were compared with that between September 1997 and August 1998. H. pylori-negative idiopathic ulcers were defined as negative tests for H. pylori, no exposure to analgesics within 4 weeks, and absence of other risk factors for ulcers. After the ulcers had healed, patients with H. pylori-negative idiopathic ulcers and patients with H. pylori ulcers who received eradication therapy were followed up for 12 months without anti-ulcer drugs. Six hundred thirty-eight patients had bleeding ulcers: 213 (33.4%) were H. pylori ulcers, and 120 (18.8%) were H. pylori-negative idiopathic ulcers (vs 480 [50.3%] H. pylori ulcers and 40 [4.2%] H. pylori-negative idiopathic ulcers in 1997-1998; P < .001). H. pylori-negative idiopathic ulcers accounted for 16.1% of patients who were admitted for bleeding and 42.4% of patients who bled while in the hospital (P < .0001); 28.3% of patients with H. pylori-negative idiopathic ulcers had histologic evidence of past H. pylori infection. The probability of recurrent ulcer complications in 12 months was 13.4% (95% CI: 7.3%-19.5%) in patients with H. pylori-negative idiopathic ulcers and 2.5% (95% CI: 0.4%-4.6%) in patients with H. pylori ulcers who received eradication therapy (P = .0002). The incidence of H. pylori-negative idiopathic bleeding ulcers is rising. These ulcers are prone to recurrent complications.

Mast cell tryptase and chymase in chronic leg ulcers: chymase is potentially destructive to epithelium and is controlled by proteinase inhibitors

Numerous mast cells are present in chronic leg ulcers. Tryptase and chymase are the major mediators of mast cells, but their significance is mostly dependent on their activity. In addition, the proteinases may affect ulcer epithelialization. To study levels and activity of tryptase and chymase in wash samples and biopsies from chronic leg ulcers and the possible effect of these proteinases on keratinocyte growth and adherence. Wash samples were taken from 16 patients and a superficial shave biopsy was taken in eight of these patients; a second biopsy series was obtained from the edge of chronic venous leg ulcers (n = 6). Significant levels of soluble tryptase activity and histamine, but low levels of chymase activity, were measured in wash samples from chronic ulcers. No tryptase-inhibiting activity, but clear chymase-inhibiting activity, was detected in the wash samples. In superficial wound bed biopsies, relatively marked levels of chymase activity together with histamine and tryptase activity were detected. In the second biopsy series, about 80% of the mast cells belonged to the MC(TC) type (tryptase- and chymase-immunopositive). However, about 55-61% of the chymase-immunopositive cells displayed chymase activity and 64 +/- 17% of the tryptase-positive cells revealed immunoreactivity of alpha(1)-antichymotrypsin. As the activity of chymase and tryptase was detected in the ulcer base in a ratio of 1:8, a preparation containing both chymase and tryptase was partially purified from human skin yielding a similar activity ratio of 1:11-13. Treatment of fibronectin-coated plastic surfaces with this preparation decreased the adherence of cultured human keratinocytes, this effect being attributable mainly to chymase. In 2-day cultures using growth factor/serum-deficient low- or high-calcium medium, the tryptase-chymase preparation inhibited the slow growth and at higher concentrations it even induced detachment of keratinocytes. This effect was attributed to chymase, and it was partially regulated by heparin and histamine. Even though chymase is partially inactivated in chronic leg ulcers, accumulated mast cells in the close proximity of the epithelium edge and their chymase may impair keratinocyte adherence and migration.

Consumption of the Epidermis

The distinction between melanoma and its most important simulant, Spitz nevus, is usually made on microscopically. We point out "consumption of the epidermis" (COE) as an additional diagnostic criterion. We defined COE as thinning of the epidermis with attenuation of the basal and suprabasal layers and loss of rete ridges in areas of direct contact with neoplastic melanocytes. We analyzed 102 unequivocal melanomas and 125 unequivocal Spitz nevi for the presence of COE. COE had not been used in arriving at the diagnosis of these cases because we were unaware of the criterion at the time that the cases were first evaluated. COE was found in 88 of 102 (86%) of melanomas but only 12 of 125 (9.6%) of Spitz nevi (P < 0.001). We then looked for COE in an independent set of 61 ambiguous melanocytic lesions with overlapping histopathologic features that could not be classified unequivocally as Spitz nevus or melanoma. The cases were analyzed by comparative genomic hybridization (CGH) for aberration patterns suggesting a benign or a malignant process, based on previous studies. COE was found in only 6 of 42 (14%) of the ambiguous cases in which CGH suggested a benign process and 14 of 19 (74%) of the ambiguous cases in which CGH suggested melanoma (P < 0.001). Our data suggest that COE is a useful criterion in the evaluation of melanocytic neoplasms. Because COE was frequently found at the edges of ulcers in the majority of ulcerated melanomas, the thinning of the epidermis in COE may represent an early phase of ulceration. This may prove to be important in distinguishing ulceration due to an effect of the tumor from ulceration due to trauma, which would be expected not to have the same prognostic import. Future studies are required to analyze the prognostic value of COE itself.

Keratinocyte and dermal vascular endothelial cell capacities remain unimpaired in the margin of chronic venous ulcer

The role of endogenously produced cytokines and growth factors in the impaired healing of chronic leg ulcers remains uncertain. The aim of this study was to determine the functional capacity of skin cells in ulcer bed tissue compared to those in the edge of ulcers and skin distal to ulcers. Biopsies from leg ulcers of ten randomly selected patients were examined immunohistochemically for cytokines and growth factors produced by keratinocytes (KC) and vascular endothelial cells (EC). The phenotype of leukocytes infiltrating venous ulcers and the expression of vascular adhesion molecules responsible for extravasation were also studied. The expression of cytokines and growth factors by KC was similar in areas adjacent and remote from an ulcer. In the dermis adjacent to an ulcer, the expression of IL-1alpha, IL-1beta, IL-1Ra, EGF and PDGFa by EC was higher than the levels of expression in EC from the distant dermis. The expression of IL-6, TNFalpha and GM-CSF was comparable to that in cells from intact dermis. For all these factors staining was cytoplasmic, suggesting production in these areas. Ulcer bed tissue contained few fibroblasts and blood capillaries showing a high staining intensity for CD62E and CD106 EC adhesion molecules but no FGF2 expression (P<0.05). The intensity of staining for scavenging CD15+ elastase+ granulocytes and CD35+ (C3bR) activated macrophages in the ulcer bed was comparable to that in the margin but higher than that in the distant dermis (P<0.05), whereas staining for CD68+, HLA DR+, TGFbeta+ and CD54+ dermal macrophages was similar in all areas. There was reduced staining for CD4+ and CD8+ cells in the ulcer bed (P<0.05). There were no CD1a+ Langerhans cells in the epidermis encroaching upon the granulation tissue and there was reduced CD1a staining in the adjacent epidermis (P<0.05). In conclusion, there is chronic accumulation of scavenging cells with lack of remodeling of the granulation tissue and, at the same time, preserved cytokine and growth factor secretory potential of KC and dermal EC in non-healing venous leg ulcers.

Anisakis in a biopsy specimen from the edge of a gastric ulcer: report of a case

Anisakis in a biopsy specimen from the edge of a gastric ulcer: report of a case

Comparing the contractile properties of human fibroblasts in leg ulcers with normal fibroblasts

The tissue contraction phenomenon associated with wound healing is of prime importance for wound closure. Contractile properties of human fibroblasts from chronic venous leg ulcers were compared with those of normal fibroblasts using in vitro models. Biopsies were taken from the uninvolved skin of the thigh, the epithelialised ulcer edge and the non-epithelialised ulcer centre in four patients (average age: 78 years). Fibroblasts were obtained by an explant technique and expanded in vitro in Dulbecco's Modified Eagle's Medium supplemented with 10% foetal calf serum and used for the assays at their fourth passage. Intracellular alpha-smooth muscle actin expression (alphaSM-actin) was studied by immunofluorescence labelling of cells cultured in monolayer. Contractile properties were evaluated using three-dimensional collagen lattices. Fibroblasts from the ulcer centre were the richest cells in actin filaments. Both populations of venous ulcer fibroblasts contracted more rapidly and to a greater extent than normal fibroblasts. The peak contractile forces developed by fibroblasts from the ulcer centre and the ulcer edge were 30% and 18% greater than normal fibroblasts respectively. Some functions of fibroblasts, in particular the generation of contractile forces and the formation of cytoplasmic actin filaments, seem not to be affected in chronic venous ulcers. This study was supported by the Fondation Coloplast pour la Qualite de la Vie of France.

Pyoderma gangrenosum complicating bilateral breast reduction

Pyoderma gangrenosum complicating bilateral breast reduction

Approximation of Large Mucosal Defects after Endoscopic Mucosal Resection: A New Technique Using a Detachable Snare and Clips

Background/Aim: With the advance of endoscopic mucosal resection (EMR) technique, en-bloc resection of larger mucosal lesion is feasible nowadays. But prolonged hospital stay due to large mucosal defect and complications including bleeding and perforations after EMR are other problems. Routine mucosal closure after EMR may decrease hospital stay and complications. However, conventional clipping is impossible for large mucosal defects. So, we developed a new approximation technique using a detachable snare and clips for large mucosal defects after EMR. Methods: After the EMR with an insulation-tipped electrosurgical knife, a detachable snare was spread on the mucosal defect via a double-channel endoscopy. Then a rotating clip-fixing device with a clip was inserted through the other channel of the endoscopy. After placing the wire of the detachable snare between both legs of the clip, this was applied to the mucosal edge of the iatrogenic ulcer. Three to five more clips were placed symmetrically at the mucosal edge in this way, and then the snare was squeezed gently. After approximation of the mucosal defect, additional long clips were applied to dehiscence area for complete closure (Fig. 1). Results: Near complete closures for iatrogenic mucosal defects could be accomplished with this technique. Approximations were maintained at day 5 endoscopy. Conclusions: Approximation technique using a detachable snare and clips is very useful for large mucosal defects after endoscopic mucosal resection. Studies for impacts on hospital stay and complications are needed.

The metabolism of the diabetic foot: in vivo investigation with microdialysis.

Many amputations might be delayed or prevented by more effective clinical supervision of the diabetic foot ulcer. The aim of this study was to measure the local metabolism on the edge of a diabetic ulcer and compare it to healthy subcutaneous tissue. In 5 non-fasting diabetic patients, we inserted a microdialysis catheter into the edge of a diabetic ulcer and a reference catheter into healthy abdominal subcutaneous tissue, and recorded the local concentrations of glucose, lactate and glycerol during rest. The concentrations of glucose in the ulcers were 7.8 mM (SEM 1.9) and in the reference tissue 10.6 mM (SEM 1.8) (p = 0.4). The concentrations of lactate were 2.9 mM (SEM 0.7) and 2.1 mM (SEM 0.7) (p = 0.2), while those of glycerol were 290 microM (SEM 84) vs 98 microM (SEM 7.2) (p = 0.002). This study shows that microdialysis can detect differences in dialysate concentrations of metabolites in diabetic ulcers and a reference tissue, providing valuable information concerning metabolites in the diabetic foot ulcer. Future studies should combine the technique with measurements of local blood flow.

Surgical pearl: full-thickness punch grafting in chronic nonhealing ulcers

N onhealing ulcers of nonspecific origin pose a great therapeutic challenge to the clinician. Healing normally takes place by ingrowth of epithelium from the edge of ulcer at a rate of 1 mm/day.1 Various methods of grafting aim at providing epithelium through autologous migration.2,3 Reverdin’s4 basic technique of grafting, “greffe epidermique,” has undergone several modifications in time. Techniques that use large-sized full-thickness or split-thickness grafts need expertise and have a higher incidence of rejection, whereas small pinch grafts often lead to cobblestoning because of their irregular thickness.2 Full-thickness punch grafting ensures uniform thickness and a higher survival rate. We have been using full-thickness punch grafting for chronic nonhealing ulcers in a modified way to prevent cobblestoning by inserting the grafts into the punch holes created in the granulation tissue, similar to that used to induce pigmentation in vitiligo. Large ulcers that fail to epithelize with local dressings for 3 to 4 weeks despite healthy granulation tissue are usually taken up for grafting. The fullthickness punch grafts (using 3-mm punch) are harvested from the buttocks or thigh. Punch holes (2 or 2.5 mm) are made in the floor of the granulating ulcer 5 mm from each other, and grafts are pushed into these recipient holes (Fig 1). The grafts usually get well taken up by the end of first week, and epithelization from the edges of graft starts by the second week (Fig 2). Complete healing is usually achieved in 4 to 6 weeks (Fig 3). We believe that full-thickness punch grafting for the nonhealing ulcer is a useful and easy-to-perform technique that hastens epithelization, because the presence of a full thickness of dermis possibly contributes dermal factors controlling epidermal proliferation. Although Mol et al,3 have used full-thickness punch grafts in venous leg ulcers compared with cultured skin equivalents, a literature search through MEDLINE did not reveal further use of this method. Moreover, our improvisation of this technique prevents cobblestoning and gives cosmetically acceptable results.

Evaluation of the efficiency of venous leg ulcer treatment with a membrane dressing

A quantitative method for the evaluation of ulcer healing has been developed. The method consists of calculating an ulcer healing efficiency ratio (ζz) interpreted as the second derivative of the regenerated ulcer area over time. The ζz value is in direct proportion to the acceleration of healing, and in inverse proportion to the initial ulcer area. In order to test this method, we measured the surface area that was delimited by the ulcer edge and the initial depth of the ulcer in three patient groups. The first and third groups were treated with a cellulose membrane and the second group—with Unna boot. The initial ulcer area was the same in groups 1 and 2, but in group 3, it was six times smaller. The greatest ζz value was obtained in group 3, the smallest—in group two.

Conjunctival ulceration following triamcinolone injection

Purpose To report conjunctival ulceration as a complication of periocular triamcinolone acetonide injection. Design Interventional case series. Methods Conjunctival ulceration was found in three patients who had anterior subtenon’s or subconjunctival deposition of triamcinolone. Cultures from the ulcer edges were negative. Results Most of the triamcinolone extruded, and the conjunctival ulcers healed with minimal scarring. Conclusions Conjunctival ulceration was a potential complication of periocular triamcinolone injection in three patients who had anterior subtenon’s or subconjunctival deposition of the corticosteroid.

Primary amyloidosis presenting with hematochezia and colon ulcers

Amyloidosis is characterized by the deposition of monoclonal immunoglobulin light chains in vital organs. Although involvement of the GI tract is relatively common in all systemic types of amyloidosis, it rarely presents with GI symptoms. We describe a case of primary amyloidosis presenting with hematochezia and diagnosed by biopsies obtained from discrete colon ulcers. A 43 year-old Central American male was admitted with progressive dyspnea on exertion. He had an 18 month history of intermittent hemoptysis associated with a dry cough, night sweats and 15 pound weight loss. For two years he had increasing intermittent painless hematochezia. His physical examination was remarkable for decreased breath sounds at the right lung base with dullness to percussion and his stool was heme positive. A chest x-ray showed a large right pleural effusion and cardiomegaly. Transthoracic echocardiogram revealed biventricular hypertrophy with hyperechogenicity/speckling of the myocardium and elevated pulmonary artery pressure. Bronchoscopy showed an enlarged epiglottis, thickened vocal cords, and multiple nodular lesions throughout the bronchial tree. Brushings from the bronchial tree were non-diagnostic. A flexible sigmoidoscopy was requested for rectal biopsies. Two easily friable ulcers with erythematous edges were seen in the sigmoid and the descending colon. Biopsies of the ulcer edges revealed deposition of proteinaceous material in the submucosa and muscularis mucosa consistent with amyloidosis. This was confirmed by Congo red staining of the material which also showed apple green birefringence under polarized light.

Cytokines and growth factors in keratinocytes and sweat glands in chronic venous leg ulcers. An immunohistochemical study.

The role of growth factors and cytokines in the impaired healing of chronic leg ulcers remains uncertain. The aim of this study was to determine whether changes in the amount and location of cytokines and growth factors may be associated with impaired healing in chronic leg ulcers. Biopsies from leg ulcers of 21 patients and from normal skin of nine healthy volunteers were examined immunohistochemically for selected growth factors and cytokines. Greater staining intensity was found in keratinocytes at the edges of ulcers compared to normal skin, or skin adjacent to the ulcers. Staining at the ulcer edge was more intense in nonhealing ulcers for only vascular endothelial growth factor and platelet-derived growth factor, whereas staining in the adjacent skin was more intense for all factors in the nonhealing phase. For all factors staining was cytoplasmic, suggesting production in these areas. This study shows up-regulation of the production of cytokines and growth factors in keratinocytes of chronic leg ulcers that is greater when the ulcers are nonhealing.

Expression of apoptosis- and cell cycle-related proteins in epidermis of venous leg and diabetic foot ulcers

Background. Epithelialization of cutaneous ulcers is a long-lasting process. To study the pathomechanism of impaired epithelialization, we evaluated the role of cell cycle- and apoptosis-related proteins in the regenerating epidermis. We characterized immunohistochemically the expression of cell cycle regulators p63, CD29, PCNA, p53, pro- and antiapoptotic proteins bcl2, bax, caspase 3 and DNA breaks, as well as keratin 10, 16 and 17. Methods. Studies were carried out in 12 patients with diabetic foot, and 10 patients with varicose ulcers of the calf. Skin biopsy specimens were obtained from the border area of ulcers and the topographically corresponding sites of normal skin of patients undergoing orthopedic surgery. Biopsy specimens were stained by use of specific primary antibodies, a kit based on biotin-avidin-peroxidase complex technique, and DAB substrate. Results were expressed as a mean staining intensity. Results. At the edge of both types of ulcers, keratinocytes were p63+, CD29+, PCNA+ and p53−. The mean intensity of p63 and CD29 staining was slightly higher than in controls. The intensity of bcl2 staining was higher at the edge of diabetic ulcers compared with venous ulcers, whereas the intensity of bax staining was similar. The expression of caspase 3 was lower at the edge of venous ulcers and higher in diabetic ulcers and the intensity of TUNEL staining was lower at the edge of both types of ulcers compared with controls. Keratinocytes at the edge and distally to both types of ulcers expressed cytokeratin 16 and 17. There was no expression of cytokeratin 10 at the edge of ulcers. Together, there was a slight tendency for higher expression of cell cycle-related proteins in venous and of apoptosis-related proteins in diabetic ulcers epidermis; however, the differences were minor. Conclusions. The impaired epithelialization of chronic leg ulcers is not caused by an inadequate epidermal stem cell proliferation, differentiation, or apoptosis. It may rather reflect the distorted organization of wound bed, caused by infection and impaired nutrition supply, altering keratinocyte migration. To accelerate healing of an ulcer, modeling of the granulation tissue by regulatory cytokines but not stimulation of keratinocyte growth seems to be indicated. (Surgery 2003;134:213-20.)

The expression of matrix metalloproteinase matrilysin indicates the degree of inflammation in ulcerative colitis.

Any alteration in the synthesis and breakdown of the extracellular matrix is important in tissue remodeling during inflammation and wound healing. The degradation of the extracellular matrix components is regulated by a cascade of matrix metalloproteinases (MMPs). The present study attempted to assess the relationship between MMPs and the degree of inflammation in ulcerative colitis. The expression of MMPs, including MMP-1, -2, -3, -7 (matrilysin), and -9, and that of their inhibitors (tissue inhibitor of metalloproteinases [TIMP]-1 and -2) were analyzed immunohistochemically by using 52 formalin-fixed and paraffin-embedded specimens from patients with ulcerative colitis who had undergone a biopsy or surgery. It was observed that MMP-1, -2, and -9, and the TIMPs were expressed in stromal cells, MMP-3 was expressed in both the epithelial cells and stromal components, and matrilysin was expressed only in the epithelial cells on the edge of ulcers. The expression of the MMPs was increased compared with that of the TIMPs. The frequency of matrilysin expression was increased corresponding to the severity of the inflammation. Matrilysin was also expressed in epithelial cells with dysplasia and cancer. Matrilysin expression could be an important marker of activity and could be used for the prediction of subsequent transformation in patients with ulcerative colitis.

The Cathelicidin Anti-Microbial Peptide LL-37 is Involved in Re-Epithelialization of Human Skin Wounds and is Lacking in Chronic Ulcer Epithelium

The human cathelicidin anti-microbial protein, hCAP18 is a component of the innate immune system and has broad anti-microbial activity conferred by its C-terminal fragment LL-37. hCAP18 is constitutively produced in leukocytes and is induced in barrier organs upon inflammation and infection. We demonstrate here a novel role for this peptide in re-epithelialization of skin wounds. We show that high levels of hCAP18 are produced in skin in vivo upon wounding. The highest hCAP18 levels are attained at 48 h post-injury, declining to pre-injury levels upon wound closure. hCAP18 is detected in the inflammatory infiltrate and in the epithelium migrating over the wound bed. In chronic ulcers, however, hCAP18 levels are low and immunoreactivity for hCAP18/LL-37 is absent in ulcer edge epithelium. Using a noninflammatory ex vivo wound healing model, composed of organ-cultured human skin, we show that hCAP18 is strongly expressed in healing skin epithelium, and that treatment with antibodies raised and affinity purified against LL-37, inhibits re-epithelialization in a concentration-dependent manner. Immunoreactivity for the proliferation marker Ki67 is absent in the epithelium of such inhibited wounds, suggesting that LL-37 may play a part in epithelial cell proliferation. Thus, we suggest that, in addition to being an anti-microbial peptide, LL-37 also plays a part in wound closure and that its reduction in chronic wounds impairs re-epithelialization and may contribute to their failure to heal.

Clinical and morphological features of reparative processes in patients with the diabetic foot syndrome

The purpose of the study was to examine structural abnormalities in the skin and granulation tissue, which explain long-term heal­ing and recurrent trophic ulcers in patients with the neuropathic diabetic foot syndrome who received adequate treatment. Biopsy specimens were taken from the granulation tissue and skin of the edge of a trophic ulcer in 12 patients (mean age 48.4+6.6 years) with types 1 and 2 diabetes mellitus (its duration was 14.0+4. 7 years). All the patients were treated for the neuropathic diabetic foot syndrome according to the generally accepted recommenda­tions. According to the duration of trophic ulcer, the patients were divided into 2 groups: 1) 4 patients with a history of under 3 months and 2) 8 patients with a history of above 3 months. Ac­cording to the presence or absence of trophic ulcers in the history, all the patients were again divided into Groups A (recurrent ul­cers, n = 5) and В (primary ulcers, n = 7). Patients with slowly healing ulcers were found to have an abnormal foot pressure more frequently, as evidenced by computerized pedography (the peak load in the ulcer area being in 63% of them versus 25% in Group 1) and some specific features of granulation tissue (excess of active fibroblasts, immaturity of the extracellular matrix, at­rophy and sclerosis of nerve fibers). Patients with recurrent ulcers were older, demonstrated lower vibration perception scores, mor­phological features, such as abundant active polymorphonuclear leukocytes, mast cells with signs of degranulation and T-helper cells, immature extracellular matrix, fibrinoid necrosis and young capillary vessels with microthrombi. Thus, the detection of the above granulation tissue and wound edge changes (especially with an abnormal foot pressure pattern, significantly low vibra­tion perception scale, and old age) makes it possible to suggest slow healing or recurrence of ulcer.