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The outer root sheath of hair follicles plays an important role in epidermal regeneration in vivo. Keratinocytes isolated by explantation of outer root sheath tissue have extensive proliferative capacity irrespective of donor age, which probably depends on pluripotent epithelial stem cells residing in the outer root sheath. These keratinocytes can be organotypically grown to epidermal equivalents in vitro. We report here that in a multicenter, randomized phase II study, EpiDex trade mark, a tissue-engineered, fully differentiated autologous epidermal equivalent derived from keratinocytes of the outer root sheath of plucked anagen hair follicles, is as effective as split-thickness skin autografting in the promotion of healing and complete closure of recalcitrant vascular leg ulcers. [ABSTRACT FROM AUTHOR]

Background: Maggot therapy (biosurgery) has received increasing interest for the debridement of chronic wounds and for the improvement of wound healing. The purpose of this study was to investigate the clinical effects, side-effects, and possible mechanisms of action of biosurgery., Methods: Biosurgery was used for debridement in 30 patients with chronic leg ulcers of mixed origin. The effect of a single application of maggots for 1-4 days was evaluated by a clinical wound score and contact-free spectroscopy. Side-effects were recorded., Results: Debridement was rapid and selective. The wound secretion was temporarily increased. We observed a significant improvement of the wound score with a decrease from 13.5 +/- 1.8 to 6.3 +/- 2.7 (P < 0.001). The treatment was well tolerated in most patients. Twelve out of 30 patients reported temporary pain, but only two needed analgesic treatment. Other side-effects included venous bleeding in one patient. The remittance spectra showed an improvement of tissue oxygenation as revealed by the characteristic oxygen doublet peak (548 and 575 nm)., Conclusions: Biosurgery is an effective and rapid treatment for the debridement of chronic wounds and the improvement of wound healing. A possible mode of action is the increase in tissue oxygenation. More studies are needed.

Objective wound monitoring is an essential tool for evidence-based medicine in leg ulcers and other chronic wounds. Non-invasive and contact-free optical remittance spectroscopy seems to be a useful approach as it can provide additional information with respect to more traditional techniques of wound scoring. Twenty-three patients with chronic venous, arterial, and mixed leg ulcers were enrolled in this study. The clinical state of the ulcers was documented by a clinical wound score (quantity, color, and consistency of granulation tissue). The spectroscopic readings were performed with a novel diode-array spectrometer system in the visible and near-infrared range of the spectrum (400-1600 nm) with a resolution of 5 nm. The wound spectra mainly depend on the absorption of hemoglobin and water. The maximum correlation coefficients of mean remittance spectra with the clinical wound scores did not exceed +/- 0.5. Discriminant and cluster analysis were applied for spectral classification of wound scores. By using cross-validation the percentage of correct predicted wound scores was about 69%. Our results indicate that the application of optical visible and near-infrared spectroscopy could be a valuable remedy for the clinician.

Background: Both interferon alpha and extracorporeal photochemotherapy have been shown to be effective in primary cutaneous T-cell lymphomas (CTCLs). However, no prospective trial has been published on the combination of both treatments, although retrospective investigations suggested a better efficacy than for either interferon or extracorporeal photochemotherapy., Objective: Our purpose was to evaluate the efficacy and toxicity of combined interferon alfa-2a with extracorporeal photochemotherapy in a prospective controlled trial., Methods: A prospective controlled study was performed. Fourteen patients (all male) aged 38 to 72 years with CTCL of the mycosis fungoides type, stage IIa/IIb, and a 72-year-old male patient with a Ki-1 lymphoma were treated twice a month for 6 months with extracorporeal photochemotherapy using oral 8-methoxypsoralen as photosensitizer in combination with interferon alfa-2a subcutaneously 3 times a week in the maximal tolerable dosage (ie, up to 18 x 10(6) U). The effects were investigated by a skin score, staging, histologic score (density of the T-cell infiltrate; from 0 = absent to 3 = heavy), immunohistology, and laboratory investigations including total peripheral T-cell count, CD4/CD8 ratio, and soluble interleukin 2 receptor (sIL-2R)., Results: After 6 months, best response was a complete response (CR) in 4 patients, a partial response (PR) in 3, and a stable disease (SD) in 7 of 14 patients (overall response rate [CR + PR] 50%). In responders the time to best response was 4.3 +/- 1.4 months. The skin score decreased from 22.5 +/- 8.1 to 15.1 +/- 11.0 (P <.001), the histologic score decreased from 2.57 +/- 0.51 to 1.21 +/- 0.80 (P <.001). In the lesional skin the percentage of CD4 cells decreased from 75% to 51% (P =.038) and Ki-67-positive cells decreased from 6.7% to 2.4% (P =.001). The total T-cell count/microL decreased from 1018.9 +/- 557.1 to 667.9 +/- 417.9 (P =.012), and the CD4/CD8 ratio also decreased from 1.88 +/- 0.92 to 1.51 +/- 0.67 (P =.038). The sIL-2R levels did not change significantly during the first 4 months of treatment. Among patients of stage IIa the response rate was 60% in contrast to only 25% of those in stage IIb. Side effects were seen temporarily, ranging from grade 0 to grade 3. There was no need for additional therapy, but interferon dose was decreased because of side effects. After 1 year of follow-up the total response rate was 46.2% (6 of 13 patients): 5 of 9 with stage IIa(55.6%) and 1 of 4 with stage IIb (25.0%)., Conclusion: These results indicate that patients with CTCL stage IIa can achieve a total response rate of 56% with combined interferon alfa-2a and extracorporeal photochemotherapy. Responders seem to experience their best response within the first 6 months of treatment. The treatment is well tolerated and does not cause severe side effects.

Guinea-pig distal colonic mRNA injection into Xenopus laevis oocytes resulted in expression of functional active epithelial Na+ channels in the oocyte plasma membrane. Poly(A)+ RNA was extracted from distal colonic mucosa of animals fed either a high-salt (HS) or a low-salt (LS) diet. The electrophysiological properties of the expressed amiloride-sensitive Na+ conductances were investigated by conventional two-electrode voltage-clamp and patch-clamp measurements. Injection of poly(A)+ RNA from HS-fed animals [from hereon referred to as HS-poly(A)+ RNA] into oocytes induced the expression of amiloride-sensitive Na+ conductances. On the other hand, oocytes injected with poly(A)+ RNA from LS-fed animals [LS-poly(A)+ RNA] expressed a markedly larger amount of amiloride-blockable Na+ conductances. LS-poly(A)+ RNA-induced conductances were completely inhibitable by amiloride with a Ki of 77 nM, and were also blocked by benzamil with a Ki of 1.8 nM. 5-(N-Ethyl-N-isopropyl)-amiloride (EIPA), even in high doses (25 "mu"M), had no detectable effect on the Na+ conductances. Expressed amiloride-sensitive Na+ channels could be further activated by cAMP leading to nearly doubled clamp currents. When Na+ was replaced by K+, amiloride (1 "mu"M) showed no effect on the clamp current. Single-channel analysis revealed slow gating behaviour, open probabilities (Po) between 0.4 and 0.9, and slope conductances of 3. 8 pS for Na+ and 5.6 pS for Li+. The expressed channels showed to be highly selective for Na+ over K+ with a permeability ratio PNa/PK > 20. Amiloride (500 nM) reduced channel Po to values < 0.05. All these features make the guinea-pig distal colon of LS-fed animals an interesting mRNA source for the expression of highly amiloride-sensitive Na+ channels in Xenopus oocytes, which could provide new insights in the regulatory mechanism of these channels.

Endogenous Na+ conductances in the plasma membrane of oocytes of the South African clawed toad Xenopus laevis were investigated by microelectrode techniques and influx measurements. Removal of Na+ from the bath solution under voltage clamp conditions led to a decrease in the clamp current indicating the existence of native Na+ conductances. The observed current was voltage dependent but showed no marked rectification. Amiloride (10 microM) blocked this Na+ current reversibly. However, amiloride analogues such as benzamil and phenamil had no effect on this Na+ conductance. The Na+/H(+)-exchanger blocker EIPA (5-(N-ethyl-N-isopropyl)amiloride), another amiloride analogue, also had no effect thereby excluding a possible involvement of the Na+/H+ exchanger. The Na+ mediated current had a reversal potential of about 50 mV suggesting high selectivity of these Na+ conductances for Na+ over other monovalent cations. When Na+ was replaced by K+ in the bath solution, amiloride had no effect on the clamp current over the whole potential range demonstrating that only Na+ but not K+ can enter the cell via the investigated conductances. In radio tracer experiments 22Na+ influx into oocytes was nearly halved in presence of amiloride (10 microM), whereas benzamil and phenamil again failed to influence 22Na+ influx. These results suggest that the endogenous amiloride-sensitive Na+ conductance belongs to a new class of channels which is quite different from amiloride-sensitive epithelial Na+ channels.