Research advances on the application of stem cells in sweat gland regeneration / 中华烧伤杂志

Sweat gland is one of the important appendage organs of the skin, which plays an important role in thermoregulation and homeostasis maintenance. Sweat glands are damaged and unable to self-repair after burns, resulting in perspiration disorders eventually. However, current clinical strategies cannot restore the function of the damaged sweat glands effectively. Therefore, it is urgent to seek treatments that can promote the regeneration of sweat glands and restore their normal functions. Stem cells have extensive sources, low immunogenicity, high proliferation capacity, and multi-directional differentiation potential, which have become a focus in the field of regenerative medicine. In recent years, a variety of stem cells have been induced to differentiate into sweat gland-like tissue with certain secretory function, which provides treatment direction for sweat gland regeneration after burns in clinic. This article reviews the recent research advances on the application of stem cells in sweat gland regeneration from the perspectives of the manner by which stem cells transform into sweat gland cells in different environments and their influencing factors.

Rib Cartilage Assessment Relative to the Healthy Ear in Young Children with Microtia Guiding Operative Timing / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>The optimal age at which to initiate for auricular reconstruction is controversial. Rib cartilage growth is closely related to age and determines the feasibility and outcomes of auricular reconstruction. We developed a method to guide the timing of auricular reconstruction in children with microtia ranging in age from 5 to 10 years.</p><p><b>METHODS</b>Rib cartilage and the healthy ear were assessed using low-dose multi-slice computed tomography. The lengths of the eighth rib cartilage and the helix of the healthy ear (from the helical crus to the joint of the helix and the earlobe) were measured. Surgery was performed when the two lengths were approximately equal.</p><p><b>RESULTS</b>The preoperative eighth rib measurements significantly correlated with the intraoperative measurements (P < 0.05). From 5 to 10 years of age, eighth rib growth was not linear. In 76 (62.8%) of 121 patients, the eighth rib length was approximately equal to the helix length in the healthy ear; satisfactory outcomes were achieved in these patients. In 18 (14.9%) patients, the eighth rib was slightly shorter than the helix, helix fabrication was accomplished by adjusting the length of the helical crus of stent, and satisfactory outcomes were also achieved. Acceptable outcomes were achieved in 17 (14.0%) patients in whom helix fabrication was accomplished by cartilage splicing. In 9 (7.4%) patients with insufficient rib cartilage length, the operation was delayed. In one (0.8%) patient with insufficient rib cartilage length, which left no cartilage for helix splicing, the result was unsatisfactory.</p><p><b>CONCLUSIONS</b>Eighth rib cartilage growth is variable. Rib cartilage assessment relative to the healthy ear can guide auricular reconstruction and personalize treatment in young patients with microtia.</p>

Advances in the research of the biological activities of degradation products of extracellular matrix / 中华烧伤杂志

ECM is a supporting structure for stabilizing the location of cells and preserving the structure of tissues. Recently, it has been discovered that ECM and its degradation products may exert profound influences on tissues and cells, such as activities of inflammatory cells and immune cells. Angiogenesis may be stimulated or inhibited by degradation products of ECM. Matrikines, liberated by partial proteolysis of ECM macromolecules, are found to regulate cell functional activities and play a significant role in wound healing or tumor invasion. Post-burn denatured dermal matrix is being studied in burn healing now. The study of post-burn denatured or necrotic dermal matrix should be emphasized in future.

Experimental study on the recycling of denatured acellular dermal matrix after burn / 中华烧伤杂志

<p><b>OBJECTIVE</b>To explore the feasibility of burn denatured acellular dermal matrix (DADM) as dermal substitute in repairing wounds.</p><p><b>METHODS</b>(1) Nine Wistar rats received a deep partial-thickness scald on the back. Full-thickness wounded skin was collected on post scald day (PBD) 1, 2, and 3 (with 3 rats at each time point), and it was treated with 2.5 g/L trypsin/0.5% Triton X-100 to remove cells to prepare DADM, respectively called DADM-1 d, DADM-2 d, and DADM-3 d. Another 3 rats without scald injury were treated with the same method as above to prepare acellular dermal matrix (ADM) to serve as control. Gross and histological observations and microbiological and biomechanical tests, including ultimate tensile strength, maximum tension, stretched length at breaking, stress-strain relationship, were conducted for the resulting ADM and DADM. (2) Another 64 rats were divided into ADM group and DADM-1 d, DADM-2 d, and DADM-3 d groups according to the random number table, with 16 rats in each group. A skin flap in size of 2.0 cm×1.8 cm was raised on the back of each rat. The above-mentioned ADM, DADM-1 d, DADM-2 d, and DADM-3 d were cut into pieces in the size of 1.8 cm×1.5 cm, and they were respectively implanted under the skin flaps of rats in corresponding group. At post surgery week (PSW) 1, 3, 5, or 9, 4 rats in each group were used to observe wound healing condition and change in implants with naked eye, and histological observation of the implants was conducted. Data were processed with one-way analysis of variance and t test.</p><p><b>RESULTS</b>(1) The freshly prepared DADM was milky white, soft in texture with flexibility, but poor in elasticity as compared with ADM. No epithelial structure or cellular component was observed in ADM or DADM under light microscope. Collagen fibers of DADM were seen to be thickened unevenly and arranged in disorder and eosinophilic. All microbiological results of DADM were negative. There was no statistically significant difference among DADM-1 d, DADM-2 d, and DADM-3 d in levels of ultimate tensile strength, maximum tension, stretched length at breaking, and stress-strain relationship (with F values from 0.088 to 3.591, P values all above 0.05). Values of the above-mentioned four indexes were the highest in DADM-3 d, they were respectively (13.0 ± 2.4) MPa, (61 ± 4) N, (173 ± 7)%, (45.7 ± 2.0)%. Values of the four indexes of ADM were respectively (19.0 ± 2.6) MPa, (95 ± 4) N, (201 ± 5)%, (62.5 ± 2.2)%, which were higher than those of DADM-1 d, DADM-2 d, and DADM-3 d (with t values from 6.424 to 17.125, P values all below 0.01). (2) No exudate or swelling in the wounds of rats, and no contraction or curling of implants were observed in every group at PSW 1, but inflammatory cells infiltration and Fbs inward migration were observed in the wound. At PSW 3, the growth of hair was normal in the wound in DADM-1 d, DADM-2 d, and ADM groups, but few and scattered hair grew in DADM-3 d group. The inflammatory cells decreased, while Fbs increased, and new capillaries were found to grow inwardly in each group. The decrease in inflammatory cells was slightly delayed in DADM-3 d group. At PSW 5, hair growth became normal, and implants shrank and thinned with fiber membrane wrapped densely and bundles of ingrowing large caliber blood vessels in all groups. The dermal matrix in each group merged with the surrounding normal tissue. At PSW 9, ADM and DADM became white, thin, and soft tissue sheet which was closely connected with the inner side of the flap. There was no infiltration of inflammatory cells in implants in either group. The collagen fibers arranged regularly and densely, and they were integrated with normal collagen tissue.</p><p><b>CONCLUSIONS</b>The burned DADM does not have obvious immunogenicity, but with good biocompatibility. It is prospective to become as a dermal substitute in repairing wounds.</p>

Transforming growth factor-β1 phage model peptides isolated from a phage display 7-mer peptide library can inhibit / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Transforming growth factor-β1 (TGF-β1) is known to have a role in keloid formation through the activation of fibroblasts and the acceleration of collagen deposition. The objective of this current study was to isolate TGF-β1 phage model peptides from a phage display 7-mer peptide library to evaluate their therapeutic effect on inhibiting the activity of keloid fibroblasts.</p><p><b>METHODS</b>A phage display 7-mer peptide library was screened using monoclonal anti-human TGF-β1 as the target to obtain specific phages containing ectogenous model peptides similar to TGF-β1. Enzyme-linked immunosorbent assay (ELISA) was performed to select monoclonal phages with good binding activity, which underwent DNA sequencing. MTT assay and apoptosis assessment were used to evaluate the biological effects of the phage model peptides on keloid fibroblasts. Immunofluorescence assay was employed to show the binding affinity of the model peptides on phages causing keloid fibroblasts. Quantitative real-time PCR analysis was carried out to detect the expressions of nuclear factor κB (NF-κB) mRNA, connective tissue growth factor (CTGF) mRNA and TGF-β receptor II (TβRII) mRNA in keloid fibroblasts.</p><p><b>RESULTS</b>Specific phages with good results of ELISA were beneficiated. Four phage model peptides were obtained. The data of MTT showed that TGF-β1 and one phage model peptide (No. 4) could promote keloid fibroblasts proliferation, however, three phage model peptides (No. 1 - 3) could inhibit keloid fibroblasts proliferation. The results of apoptosis assessment showed that the three phage model peptides could slightly induce the apoptosis in keloid fibroblasts. The data of immunofluorescence assay revealed that the model peptides on phages rather than phages could bind to keloid fibroblasts. The findings of quantitative real-time PCR analysis suggested that the expressions of NF-κB mRNA and CTGF mRNA in the three phage model peptide groups decreased, while the expression of TβRII mRNA slightly increased.</p><p><b>CONCLUSIONS</b>Three phage model peptides isolated from a phage display 7-mer peptide library can inhibit keloid fibroblasts proliferation and induce the apoptosis in keloid fibroblasts. They can inhibit the activity of keloid fibroblasts by blocking TGF-β1 binding to its receptor and then regulating the expressions of NF-κB, CTGF and TβRII.</p>

Keratinocyte growth factor phage model peptides can promote epidermal cell proliferation without tumorigenic effect / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Keratinocyte growth factor (KGF) significantly influences epithelial wound healing. The aim of this study was to isolate KGF phage model peptides from a phage display 7-mer peptide library to evaluate their effect on promoting epidermal cell proliferation.</p><p><b>METHODS</b>A phage display 7-mer peptide library was screened using monoclonal anti-human KGF antibody as the target. Enzyme linked immunosorbent assay (ELISA) was performed to select monoclonal phages with good binding activity. DNA sequencing was done to find the similarities of model peptides. Three-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay, immunofluorescence assay and quantitative real-time PCR analysis were employed to evaluate the effect of the phage model peptides on epidermal cells.</p><p><b>RESULTS</b>Thirty-three out of fifty-eight (56.9%) of the isolated monoclonal phages exhibited high binding activity by ELISA. Ten of fifteen obtained phage model peptides were similar to KGF or epidermal growth factor (EGF). MTT assay data showed that four (No. 1 - 4) of the ten phage model peptides could promote epidermal cell proliferation. The expression of keratinocyte growth factor receptor (KGFR) mRNA in the KGF control group and the two phage model peptide groups (No. 1 and No. 2) increased. Expression of c-Fos mRNA and c-Jun mRNA in the KGF control group increased, but did not increase in the four phage model peptide groups (No.1 - 4).</p><p><b>CONCLUSION</b>Four phage model peptides isolated from the phage display 7-mer peptide library can safely promote epidermal cell proliferation without tumorigenic effect.</p>

The changing pattern of stem cell markers of sweat gland in deep partial-thickness burn wound / 中华烧伤杂志

<p><b>OBJECTIVE</b>To investigate the rules of proliferation of epithelial cells of sweat glands in deep partial-thickness burn wound and its transdifferentiation towards epidermal cells during healing process to explore its mechanisms.</p><p><b>METHODS</b>Twenty-eight patients with limbs and trunk burn hospitalized in the Fourth People's Hospital of Taizhou City of Jiangsu Province and the Second Hospital of Shandong University from January 2004 to December 2007 were enrolled in the study. Tissue samples of deep partial-thickness burn wound (DPBW, n = 37), superficial partial-thickness burn wound (SPBW, n = 21), and normal skin (NS, n = 10) were harvested. Expressions of cytokeratin 10 (CK10), bcl-2, P63, CK14 and CK19 of epithelial cells in glandular secretory portion (GSP) in DPBW, SPBW and NS were detected with immunohistochemical double staining method.</p><p><b>RESULTS</b>In NS, CK19, CK14 and CK10 expressed in medium intensity in GSP epithelial cells, P63 and CK14 weakly expressed in basal myoepithelial cells, while no expression of bcl-2 or P63 was observed in all CK10 positive terminally differentiated cells. In SPBW, no change of the construction of GSP and above-mentioned proteins during healing process was observed. In DPBW, as examined on 7(th) post burn day (PBD), expression of P63 and bcl-2 in GSP epithelial cells was enhanced. In DPBW on 8 - 10 PBD, bcl-2, P63, CK19 and CK14 strongly positive solid island-like epithelial structure was formed by proliferation, migration and squamous epithelization of basal cells. Such structure, along with granulation tissue, migrated towards the superficial layer of wounds. The hyperplasia of squamous epithelium resulted in complete reepithelialization. In DPBW, bcl-2, CK14, CK19 and P63 still strongly expressed in hyper-proliferative epidermal basal and suprabasal layers on 13 - 30 day after healing.</p><p><b>CONCLUSIONS</b>During the natural healing process of DPBW, monolayer epithelium (CK19 and CK10 positive) of GSP slowly develops into stratified squamous epithelium (bcl-2, P63, CK19, and CK14 positive), suggesting that the epithelial-epidermal transdifferentiation of GSP undergoes slow retrodifferentiation process of stem cells and transient amplifying cells, resulting in the imbalance between lagged growth of epithelium and the hyperplasia of granulation tissue, constituting one of the important mechanisms of disturbance in DPBW repair.</p>

The correlation of the fetal cytokeratin expressing in epidermal cells and the different outcomes of wound repairing / 中华外科杂志

<p><b>OBJECTIVE</b>To investigate the changing regular of specific cytokeratin (CK) markers expressing in human pseudoepitheliomatous hyperplasia (PEH), keloids (Ke) and hypertrophic scar (HS) lesion, and to explore the correlation between such changes and the different outcomes of wound repair.</p><p><b>METHODS</b>Histopathology and immunohistochemistry (IHC) double staining methods were used in samples of human PEH, Ke, HS and NS to determine the distribution characteristics and changing regularity of CKs in epidermal tissues.</p><p><b>RESULTS</b>No CK8&18 and CK17 expressed in epidermis of NS group, while CK8&18(+) cells and CK17(+) cells were detected in epidermis of active-stage Ke, HS and PEH. The quantities of CK8&18(+) cells and CK17(+) cells ranked as follows: PEH > Ke > HS and HS > Ke > PEH (P < 0.05). CK19(+) cells and CK5&6(+) cells expressed similar changing trend, while reverse trend of CK10(+) cells was detected in epidermal cells, with local epidermal hyperplasia, cells morphological changes and sub-epidermal inflammatory reaction.</p><p><b>CONCLUSION</b>Different degree of de-differentiation and terminal differentiation imbalance are found in epidermal cells of active-stage PEH, Ke and HS, which hint the correlation between the abnormal proliferation and differentiation of epidermal cells and the different outcomes of wound repair.</p>

Relationship between the proliferation and immunoinduction of epithelial cells and the destruction of hair follicles and sebaceous glands in keloids / 中华整形外科杂志

<p><b>OBJECTIVE</b>To investigate the influence of biological behavior of epithelial cells on the hair follicles and sebaceous glands (HFSG) structure in keloids (K).</p><p><b>METHODS</b>The expression of intercellular adhesion molecule (ICAM)-1, D-related human leucocyte antigen (HLA-DR), and cytokeratin (CK) 14 on epithelial cells and the amount of activity T-lymphocytes were detected in specimens of keloid edge and normal skin with immunohistochemical and histological methods.</p><p><b>RESULTS</b>In comparison with normal skin specimens, epithelial cells were proliferated in K-HFSG presented structural aberration and disintegrate or abnormally to form solid-epithelial island-like structure, and the density of HSFG with hyperplasia and the ageing scar in keloids was apparently decreased. They strongly expressed ICAM-1, HLA-DR, and CK14 in the epithelial cells, there were many immunologic cells which expressed CD4, CD45RO, and interferon (IFN)-gamma around the K-HFSG. The expressed level of epithelial cells was positively correlated with the density of immunologic cells nearby K-HFSG.</p><p><b>CONCLUSION</b>It could be concluded that the reactivity with hyperplasia and immunoinduction of epithelial cells might be associated with the destruction of the some HFSG structure in the keloids.</p>

Investigation of mesenchymal-epithelial transdifferentiation in the morphogenesis mechanism of embryonic epidermic cells / 中华外科杂志

<p><b>OBJECTIVE</b>To study the relationship between the morphologic mechanism of human embryonic epidermic cells and mesenchymal-epithelial transformation (MET) and its modulation factor.</p><p><b>METHODS</b>Morphological occurrence of epidermis was detected with histologic methods in earlier period [estimated gestational age (EGA) 6-14 weeks] human embryonic skin samples. At the same time, the characteristic expression and their distribution markers of mesenchymal cells [vimentin and alpha-smooth muscle actin (alpha-SMA)], embryonic specific epidermic protein CK8&18, specific protein of epidermic stem cell CK19, transforming growth factor-beta1) (TGF-beta1) and its receptor (TGFbetaRI) in embryonic epidermis were examined with immunohistochemistry and indirect-immunofluorescent doble-labelling method.</p><p><b>RESULTS</b>During EAG 6-8 weeks, ectodermal cells containing Vim+/alpha-SMA(-) were found to transform into epidermal stem cells with CK8&18+/CK19+. In ectodermal cells, protein expression density of TGFbetaRI was moderate (+ +), while positive signal of TGFbeta1 was weak (+/-). After EGA10 weeks, epidermal cells showed typical morphological characteristics.</p><p><b>CONCLUSIONS</b>At EGA 6-8 weeks, human embryonic skin epidermal cells began to form through MET, in which the signal pathway mediated by TGFbetaRI might play important roles, but the role of TGFbeta1 need to be further studied.</p>

Relationship of overexpression of angiogenesis factors and their receptors with invasive growth of keloid / 中华整形外科杂志

<p><b>OBJECTIVE</b>To study the relationship between invasive growth and the angiogenesis factors and their receptors in keloid.</p><p><b>METHODS</b>Biopsies from 17 keloid (Ke) were divided into atrophy group (Ke-A, n = 9), proliferating group (Ke-P, n = 13), infiltrating group (Ke-I, n = 9), normal skin around Ke (Ke-N, n = 10) and normal skin (NS, n = 10). The histology, immunohistochemistry and computerized imaging analysis were used for the study. The levels of basic fibroblast growth factor (bFGF) and its receptor-Flg, vascular endothelial growth factor (VEGF) and VEGF/KDR complex (11B5), and platelet derived growth factor (PDGF-A) and its receptor-PDGFR-alpha, and alpha-smooth muscle actin (alpha-SMA) were determined in specimens with immuneohistochemical staining.</p><p><b>RESULTS</b>In all 5 groups, bFGF, Flg, VEGF, 11B5, PDGF-A, and PDGFR-alpha were all expressed in fibroblasts (Fb), monocyte-phagocytes, vascular endothelial cells, adventitial cells, epidermal (cells and epithelial cells in appendage. The intensities of staining ranked as follows: Ke-I > Ke-N approximately equal to Ke-P > Ke-A approximately equal to NS, Flg > hFGF approximately equal to PDGFR-alpha > PDGF-A approximately equal to 11B5 > VEGF (P < 0.05 to approximately 0.01). 11B5 and VEGF were expressed (intensively in alpha-SMA positive myofibroblasts only in Ke-I group. The histological observation showed hyperplasia of endothelial cells and obliteration of microvessels.</p><p><b>CONCLUSION</b>The invasive growth of keloid may be related to the overexpression of angiogenesis factors and their receptors. The abnormal expression of 11B5 in myofibroblasts may be one of the important factors associated with tumor-like growth feature in the invasive parts sites of keloid. The results suggest that inhibition of these biological activities would be of significance in clinical therapy.</p>

Gene expression of extracellular-signal regulated protein kinase 5 and their MAPKK in fetal skin hypertrophic scars / 中华整形外科杂志

<p><b>OBJECTIVE</b>To explore the change of gene expression of extracellular-signal regulated protein kinase 5 (ERK5) and its upstream signaling molecule (MEK5) in fetal skin of differentially developmental stages and hypertrophic scars.</p><p><b>METHODS</b>After morphological characteristics of skin of different developmental stages and hypertrophic scars were detected with pathological methods, gene expression of ERK5 and MEK5 was examined with reverse transcription-polymerase chain reaction analysis (RT-PCR).</p><p><b>RESULTS</b>In early gestational fetal skin, genes of ERK5 and MEK5 were strongly expressed, while in late gestational skin and children skin, the expression of ERK5 and MEK5 was apparently decreased (P < 0.05). In normal skin, the level of gene expression of ERK5 was lower. In proliferative hypertrophic scars, mRNA content of this gene was apparently increased. In mature scars, the content of this gene transcript was 3.2 times the normal skin. In contrast, the levels of MEK5 transcript in normal skin and hypertrophic scars of various phases showed no substantial changes (P > 0.05).</p><p><b>CONCLUSION</b>ERKS medicating signaling pathway might be involved in regulating cutaneous development at the embryonic stage and determining cutaneous structure ad function. The increase of gene transcription of ERK5 and MEK5 in younger fetal skin might be a reason for rapid proliferation of the skin cells and scraless healing of skin. The activation of ERK5 gene expression in hypertrophic scars versus normal skin might be one of the mechanisms controlling the formation of hypertrophic scars, in which the role of MEK5 needed to be further studied.</p>

Relationship between epithelial-immunologic cells transdifferentiation and pseudoepitheliomatous granuloma lesion / 中华外科杂志

<p><b>OBJECTIVE</b>Inappropriate treatment at early stage of wound could result in the formation of pseudoepitheliomatous granuloma (PEG). The correlation of abnormal transdifferentiation of epithelial cells to immunologic cells and the occurrence of PEG lesion was investigated.</p><p><b>METHODS</b>Morphological change of epithelial tissue was observed with histopathology in 11 specimens of PEG lesions and 6 specimens of normal skins from PEG edge (PEG-N) from 11 patients with damaged skin. The expression characteristics and distribution of pan-cytokeratin (CKp), IV type collagen, laminin (LM), epithelial cadherin (E-Cad), beta-catenin (beta-Cat), focal adhesion kinase (FAK), stem cell factor (SCF) and its receptor-c-Kit, proliferating cell nuclear antigen(PCNA), and cluster of differentiation-14 (CD14), CD68 and mast cell tryptase (MCT) in PEG were detected with the immunohistochemical and the indirect immunofluorescent double-staining.</p><p><b>RESULTS</b>In comparison with PEG-N, epithelial tissue take on squamous metaplasia, and stroma was infiltrated with intensive microvessels and inflammatory cells in the PEG lesion. Poor epithelial basal layer constitution, basal polarization, and migration of basal cells to stroma could be observed. In the ultrastructure, the loose intercellular junction of basal cells and the increased nucleus/cytoplasm ratio and intercellular space could be observed, neonatal monocytoid cells and macrophages and mast cells as a exuviate-like manner brooded from cytoplasm of original epithelial cells and basement membrane. protein expression of CKp and E-Cad by basal cells was significantly decreased, and the IV type collagen and LM protein could not be found in basement membrane of identical locus. By contrast, the immunoreactivity of beta-Cat and FAK was apparently increased. In addition, CD14(+) monocytes, CD68(+) macrophages, MCT(+) mast cells and CD68(+)/MCT(+) cells with various size, and these cells of stronger immuno-staining of SCF, c-Kit and PCNA antigen could be found in epithelial tissue and stroma.</p><p><b>CONCLUSION</b>Epithelial cells in PEG related to wound are characteristized by transdifferentiation of epithelial cells to immunologic cells, wich may be associated with local infectious and inflammatory reaction, ultimately resulting in enhancement the ratio of beta-Cat/E-Cad signal and activation SCF-c-Kit signal pathway. The phenomena of transdifferentiation epithelial cells in the PEG lesion will help to recognize of the neoplatic immune and trauma repair mechanism.</p>

Experimental study and clinical application of composite skin grafting / 中华烧伤杂志

<p><b>OBJECTIVE</b>To explore an ideal skin substitute with its appearance and texture similar to normal skin, to repair wounds with full-thickness skin defect.</p><p><b>METHODS</b>Composite skin (CS) in question was composed of allo/xenogeneic acellular dermal matrix (ADM) and razor thin autoskin. One step skin grafting was employed in the experimental study and clinical trial. Razor thin autoskin alone was used as the control in the study. Changes in the antigenicity of ADM and the reformation of basement membrane (BM) structure at epidermis-dermis junction (EDJ) of ADMs were studied at designated time points after the grafting with biochemical and immunohistochemical methods. Fifty-three patients with full thickness skin defects due to various causes, including scar excision were grafted with CS, and survival rate and long-term result were observed.</p><p><b>RESULTS</b>The grafted CS survived satisfactory. The reformation of the basement membrane structure was clearly observed at the 28th post-graft week. The basement membrane cells grew with polarization in an undulating arrangement. There was reformation of dermal papillae and ridges. The antigenicity of allo-ADM was obviously lower than that of xeno-ADM. Sixty-five out of 70 pieces of CS grafting (92.9%) survived totally, two of them survived partially, and three failed due to infection. The longest follow-up period was 8 and a half years. The grafted CS appeared similar to the normal skin in regard to the texture and color, especially allo-ADM, and no evident rejection reaction was seen.</p><p><b>CONCLUSION</b>ADM possessed very low antigenicity, thus serving a lasting framework after grafting. In addition, it could serve as a "dermal template" for the induction of tissue regeneration.</p>

An experimental study on the difference of the antigenicity of xenogenic acellular dermal matrix / 中华烧伤杂志

<p><b>OBJECTIVE</b>To investigate the difference of the antigenicity of xenogenic acellular dermal matrix (ADM) implants prepared by different methods.</p><p><b>METHODS</b>The split-thickness skin sheet from swine was processed by trypsin and Triton X-100 to make xeno-ADM. Twenty-five Japanese white rabbits were divided into 5 groups, i.e. xeno-ADM(1) (conjugated with glutaraldehyde), xeno-ADM(2) (conjugated with network) and xeno-ADM(3) (no conjugation, as control), in which the ADMs were and xeno-ADM(4) (conjugated) and allo-ADM (no conjugated as control), in which the ADMs were embedded into the subcutaneous place of rabbit ear and back after that the rabbits were pre-sensitized by xeno-ADM soluble protein antigen injections. The titers of anti ADMs antibody in rabbit serum were monitored during 2 - 32 post-operative weeks and the histological changes of the embedded ADMs were observed grossly and microscopically.</p><p><b>RESULTS</b>The serum titers of anti-xeno-ADM in xeno-ADM(4) group was the highest. Whereas regardless of the sensitizing effects, the titers in all groups ranged as follows: xeno-ADM(3) > xeno-ADM(2) > xeno-ADM(1) (P < 0.05 - 0.01). About 40% serum samples in allo-ADM group exhibited positive anti-allo-ADM protein antibodies. Histologically, Evident and lasting inflammatory reaction could be found in the xeno-ADM grafting sites, which was much stronger than that in allo-ADM group. The degradation and absorption gradient of ADM was ranked as follow: xeno-ADM(3) > xeno-ADM(2) > xeno-ADM(4) > xeno-ADM(1) > Allo-ADM. Foreign body megalocytic reaction might evoke in the surrounding of conjugated ADM.</p><p><b>CONCLUSION</b>The immunogenicity in xeno-ADM was stronger than that in allo-ADM, which could induce the host to develop immune reaction restricted by IgG. Large sheets of degenerated ADM implants could lower down the antigen-antibody reaction and ameliorate the structural destroying and degeneration absorption of ADM induced by inflammatory immune reaction.</p>

Clinical study on the immunoregulation effects of cytokines on the acellular xenogenic dermal matrix / 中华烧伤杂志

<p><b>OBJECTIVE</b>To investigate the relationship between some cytokines and early outcome of grafts in burn patients receiving xeno-/allo-ADM grafting.</p><p><b>METHODS</b>Nineteen xeno-ADMs were grafted onto the wounds of 12 patients after escharectomy in extremities, and 18 allo-ADMs were grafted onto the escharectomy wounds of 15 patients in extremities. All the grafts were covered with thin split thickness skin autografts. Six patients grafted with split thickness skin autografts (auto-TTS) were employed as control. After the grafts survived for 4 to 8 weeks, immunohistochemistry and ELISA methods were employed to determine the contents of IL-1 beta, IL-4, IL-6, TNF-alpha and IFN-gamma in the exudation fluid from wounds after the rejection of xeno-ADM, local skin and peripheral blood.</p><p><b>RESULTS</b>It was exhibited by immunochemistry staining that the positive cellular density and staining intensity of the IL-1 beta, IL-4, IL-6, TNF-alpha and IFN-gamma in the grafts were ranked as following: Xeno-ADM > allo-ADM > auto-TTS (P < 0.05 - 0.01). The levels of IL-4, IL-6, TNF-alpha and IFN-gamma in the exudation fluid during the rejection of xeno-ADM were obviously higher than those in the blood of the patients as determined by ELISA, while the serum levels of IL-4 and IFN-gamma in xeno-ADM group were lower and higher than those in xeno-ADM when without rejection respectively. The serum levels of IL-4, TNF-alpha and IFN-gamma in xeno-ADM group were significantly higher than those in allo-ADM and auto-TTS groups (P < 0.05 - 0.01).</p><p><b>CONCLUSION</b>Local detection of high levels of IL-1 beta, IL-4, IL-6, TNF-alpha and IFN-gamma might be related to the immune augmentation mediated by cytotoxic lymphocytes and cytokines. The dynamic changes of these cytokines might be helpful to the explanation of the bad outcome of xeno-ADMs.</p>

Study on the typing of immunocytes after xenogeneic or allogeneic acellular dermal matrix grafting / 中华烧伤杂志

<p><b>OBJECTIVE</b>To investigate the immunologic reaction difference between xenogeneic and allogeneic acellular dermal matrix (ADM) grafting.</p><p><b>METHODS</b>Split thick skin samples harvested from healthy piglets and human volunteers who underwent losing-weight operation were processed to be xeno-ADM and allo-ADM. The ADMs overlapped with ultrathin auto-skin were employed to immediately cover the wound after escharectomy in deep burn patients. The patients were correspondingly set to be Xeno (26 cases) and Allo (10 cases) groups. Another 8 cases with deep burn wounds were grafted with only split thick autoskin (TTS) after escharectomy as control group. The tissue samples from grafted area were observed by immunohistochemistry after the grafting. The typing of immune cells in peripheral blood and grafted tissue was determined.</p><p><b>RESULTS</b>(1) The CD4(+), CD45RO(+) and CD4(+)/CD8(+) cell ratios in peripheral blood in Xeno group increased slightly after the skin grafting when comparing to those in control group (P > 0.05). (2) There existed lasting inflammatory and immunological reaction in the local site of grafts in Xeno group. In addition, more than 80% of the inflammatory cells could be found to be CD3(+)/CD4(+), CD45RO(+). But CD8(+), Vs8C(+) plasmocytes and CD57(+) NK cells were found less. Furthermore, eosinophil and CD68(+)/CD4(+) foreign body megalocyte reactions could also be identified, especially in Xeno-ADM before rejection (P < 0.05 - 0.001). There was only mild inflammatory and immunological reaction during early grafting stage (within 8 post-operational weeks) in Allo-group.</p><p><b>CONCLUSION</b>The specific immunologic reaction of human host to ADM might be participated by mononuclear cells and macrophages and presented mainly as cellular immune reaction induced by CD4(+) T lymphocytes. Furthermore, the foreign body megalocyte constructed by help T cell and macrophage might play important roles in the reaction.</p>