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Scarring, a prevalent issue in clinical settings, is characterized by the excessive generation of extracellular matrix within the skin tissue. Among the numerous regulatory factors implicated in fibrosis across various organs, the apelin/APJ axis has emerged as a potential regulator of fibrosis. Given the shared attribute of heightened extracellular matrix production between organ fibrosis and scarring, we hypothesize that the apelin/APJ axis also plays a regulatory role in scar development. In this study, we examined the expression of apelin and APJ in scar tissue, normal skin, and fibroblasts derived from these tissues. We investigated the impact of the hypoxic microenvironment in scars on apelin/APJ expression to identify the transcription factors influencing apelin/APJ expression. Through overexpressing or knocking down apelin/APJ expression, we observed their effects on fibroblast secretion of extracellular matrix proteins. We further validated these effects in animal experiments while exploring the underlying mechanisms. Our findings demonstrated that the apelin/APJ axis is expressed in fibroblasts from keloid, hypertrophic scar, and normal skin. The regulation of apelin/APJ expression by the hypoxic environment in scars plays a significant role in hypertrophic scar and keloid development. This regulation promotes extracellular matrix secretion through upregulation of TGF-ß1 expression via the PI3K/Akt/CREB1 pathway.
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Cicatriz Hipertrófica , Queloide , Animales , Apelina/genética , Apelina/metabolismo , Receptores de Apelina/genética , Receptores de Apelina/metabolismo , Fibrosis , Queloide/metabolismo , Fosfatidilinositol 3-Quinasas , HumanosRESUMEN
Background: The relationship between inflammation-related genes (IRGs) and keloid disease (KD) is currently unclear. The aim of this study was to identify a new set of inflammation-related biomarkers in KD. Methods: GSE145725 and GSE7890 datasets were used in this study. A list of 3026 IRGs was obtained from the Molecular Signatures Database. Differentially expressed inflammation-related genes (DEGs) were obtained by taking the intersection of DEGs between KD and control samples and the list of IRGs. Candidate genes were selected using least absolute shrinkage and selection operator (LASSO) regression analysis. Candidate genes with consistent expression differences between KD and control in both GSE145725 and GSE7890 datasets were screened as biomarkers. An alignment diagram was constructed and validated, and in silico immune infiltration analysis and drug prediction were performed. Finally, RT-qPCR was performed on KD samples to analyze the expression of the identified biomarkers. Results: A total of 889 DEGs were identified from the GSE145725 dataset, 169 of which were IRGs. Three candidate genes (TRIM32, LPAR1 and FOXF1) were identified by the LASSO regression analysis, and expression validation analysis suggested that FOXF1 and LPAR1 were down-regulated in KD samples and TRIM32 was up-regulated. All three candidate genes had consistent changes in expression in both the GSE145725 and GSE7890 datasets. An alignment diagram was constructed to predict KD. Effector memory CD4 T cells, T follicular helper cell, Myeloid derived suppressor cell, activated dendritic cell, Immature dendritic cell and Monocyte were differentially expressed between the KD and control group. Sixty-seven compounds that may act on FOXF1, 108 compounds that may act on LPAR1 and 56 compounds that may act on TRIM32 were predicted. Finally, RT-qPCR showed that the expression of LPAR1 was significantly lower in KD samples compared to normal samples whereas TRIM32 was significantly higher, while there was no difference in the expression of FOXF1. Conclusion: This study provides a new perspective to study the relationship between IRGs and KD.
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Queloide , Humanos , Queloide/genética , Biomarcadores , Grupos Control , Inflamación/genética , Factores de Transcripción ForkheadRESUMEN
BACKGROUND: To identify the anti-fibrosis effect of PRAS40 in scar, and its potential mechanism. METHODS: We constructed a rat model of hypertrophic scarthat was locally injected the PRAS40 overexpression adenoviruses, mTORC1 inhibitor MHY1485 and activator rapamycin, and further observed the pathological changes of skin tissue and the severity of fibrosis by HE, Masson and sirius red staining, and analyzed the deposition of a-SMA and collagen I by western blot and immunofluorescence test. Meanwhile, the co-localization of KLF4 with a-SMA and type I collagen was analyzed, as well as the regulatory effect of PRAS40 on KLF4. In addition, we also verified whether the inhibition of scar fibrosis by PRAS40 is related to mTORC1, and whether the upregulation of KLF4 is related to mTORC1. RESULTS: The results showed that the expression of PRAS40 was low and p-PRAS40 was high in scar skin tissue. After local injection of PRAS40 overexpression adenovirus, the expression of PRAS40 in skin tissue was increased. The overexpression of PRAS40 can inhibit scar skin fibrosis and reduce the content of a-SMA and collagen I. Further mechanism analysis confirms that the inhibitory effect of PRAS40 on skin fibrosis is related to mTORC1, and PRAS40 inhibits the activation of mTORC1. The expression of KLF4 is relatively low in scar tissue. PRAS40 administration upregulated the expression of KLF4, which is related to mTORC1 CONCLUSIONS: PRAS40 significantly improves fibrosis of scar skin tissue and increases the expression of KLF4 in scars. The anti-fibrotic effect of PRAS40 depends on mTORC1.
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Cicatriz Hipertrófica , Fibrosis , Factor 4 Similar a Kruppel , Factores de Transcripción de Tipo Kruppel , Diana Mecanicista del Complejo 1 de la Rapamicina , Animales , Factores de Transcripción de Tipo Kruppel/metabolismo , Factores de Transcripción de Tipo Kruppel/genética , Fibrosis/metabolismo , Diana Mecanicista del Complejo 1 de la Rapamicina/metabolismo , Ratas , Cicatriz Hipertrófica/metabolismo , Cicatriz Hipertrófica/patología , Cicatriz Hipertrófica/prevención & control , Colágeno Tipo I/metabolismo , Piel/metabolismo , Piel/patología , Proteínas Adaptadoras Transductoras de Señales/metabolismo , Ratas Sprague-Dawley , Modelos Animales de Enfermedad , Actinas/metabolismo , Sirolimus/farmacología , Sirolimus/uso terapéutico , Masculino , Regulación hacia Arriba , Colágeno/metabolismoRESUMEN
Brain edema could be secondary to cerebral lesion caused by a variety of reasons, severe cases may result in brain herniation or even death. Accurate real-time monitoring of cerebral edema, rational application of dehydrating drugs, and timely treatment of cerebral edema were very important for patients. However, there were defects in the monitoring methods commonly used in clinical practice. Noninvasive brain-edema monitoring was a new method, which can quantify the degree of brain edema by electromagnetic disturbance and directly reflect the state of brain edema. This article reviews the application of noninvasive brain-edema monitoring in the treatment of in critically ill patients with traumatic brain injury.
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Edema Encefálico , Lesiones Traumáticas del Encéfalo , Humanos , Enfermedad Crítica , Encéfalo , Edema/complicacionesRESUMEN
The burn wound is a dynamic living environment that is affected by many factors. It may present a progressive expansion of necrosis into the initially viable zone of stasis within a short time postburn. Therefore, how to salvage of the zone of stasis is of crucial importance in prevention and treatment strategies of burn wound progressive deepening. This review focuses on the cellular basis of tissue injury and the current progress of prevention and treatment strategies of burn wound progressive deepening, in order to provide references for the treatment of burn wounds in the early phase.
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Objective: The bacterial cellulose membrane (BCM) has been widely studied and applied as a new biomaterial for wound healing, but causes pain with frequent dressing changes. Local application of bone marrow mesenchymal stem cells (BMSCs) requires a niche. Furthermore, the effect and mechanism of the BCM combined with BMSCs have not been reported. Methods: Morphological and chemical identifications of BCMs were investigated by porosity analyses, scanning electron microscopy, and Fourier-transform infrared spectroscopy. Biological wound dressings (BWDs) were prepared by the BCM in combination with BMSCs. The biological effects of BWDs on human dermal fibroblast (HDF) and VEGF-A in human vascular endothelial cells (HuVECs) were detected in vitro, and the effect of BWDs on acute wounds in mice was detected in vivo. Collagen and angiogenesis were evaluated through hematoxylin-eosin staining and Masson staining. The expressions of COL-1 and VEGF-A and the activation of the Notch signaling pathway in vivo and in vitro were detected by quantitative reverse-transcriptase polymerase chain reaction. Results: The BCM had a nanoscale structure and provided a partial niche for the survival and proliferation of BMSCs. BWDs were successfully prepared and regulated the biological behaviors of wound healing-related cells in vitro and upregulated the expressions of COL-1 in HDF and VEGF-A in HuVECs. BWDs promoted wound healing by increasing collagen type I synthesis and angiogenesis in acute wounds in mice. Conclusions: BWDs prepared by the combination of nanomaterial BCMs and BMSCs facilitated acute wound healing, which may be regulated by activating the Notch signaling pathway.
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Burns often cause loss of skin barrier protection, fluid exudation, and local tissue edema, which hinder functional recovery. Effectively improving the quality of deep burn wound healing, shortening the wound healing time, and reducing tissue fluid leakage are urgent problems in the medical field. Human mesenchymal stem cells (MSCs) can effectively stabilize vascular endothelial injury. Fetal dermal MSCs (FDMSCs) are a newly discovered source of MSCs derived from the skin of accidentally aborted fetuses. However, the effect of FDMSCs on vascular permeability remains poorly understood. In this study, conditioned media from FDMSCs (F-CM) extracted from fetal skin tissue was prepared. The effect of F-CM on vascular permeability was evaluated using the internal circulation method FITC-dextran in vivo, and several in vitro assays, including cell viability assay, transwell permeability test, immunofluorescence, and western blotting. Altogether, our results demonstrate that F-CM could inhibit burn-induced microvascular hyperpermeability by increasing the protein expression levels of occludin and VE-cadherin, while restoring the expression of endothelial F-actin, and providing the foundation of a novel therapy for the treatment of burns with F-CM.
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Quemaduras , Células Madre Mesenquimatosas , Quemaduras/metabolismo , Quemaduras/terapia , Permeabilidad Capilar , Medios de Cultivo Condicionados/metabolismo , Medios de Cultivo Condicionados/farmacología , Humanos , Cicatrización de HeridasRESUMEN
Burn is one of the common traumatic diseases in clinics. After deep burn, the complicated changes of the condition are caused by the burn wound, which ends with the repair of the wound. For patients with deep burns, whether the wound can be repaired as soon as possible is the key to the success of clinical treatment. For patients with deep burns, due to the lack of an autologous skin source, scar hyperplasia at donor site, skin graft repair at donor site, postoperative flap necrosis, and other problems in traditional surgical procedures, the method of improving function only by an autologous skin source has been unable to perform the later function reconstruction in patients with deep burns. In this study, collagen sponge combined with autologous skin graft was used to treat patients with deep burn, and the clinical efficacy of the patients was observed, and the related factors affecting the efficacy of the patients were analyzed. The results showed that collagen sponge combined with autologous skin graft was effective in the treatment of deep burn patients, and it was worth popularizing. Deep III-IV degree burns, wound infection, and hospital stay >3 months are all risk factors affecting the postoperative curative effect of patients. Therefore, in the clinical work, we should focus on patients with deep III-IV degree burns, perform surgery as soon as possible, and actively deal with wounds to prevent infection, which is beneficial to improve the curative effect.
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The main characteristic of skin aging is the change in the composition of the dermis, mainly resulting from fibroblast senescence. Mesenchymal stem cells derived from fetal dermis are defined as fetal dermal mesenchymal stem cells; they reportedly exert wound healing effects on the skin and regulate keloid fibroblast proliferation. D-Galactose is widely used in animal aging models. In this study, we confirmed that D-galactose inhibits adult dermal fibroblast proliferation, and the inhibitory effect gradually increased with increasing concentration. Finally, we chose a concentration of 40 g/L D-galactose to induce adult dermal fibroblast senescence. D-Galactose increased the intensity of senescence-associated ß-galactosidase staining and the levels of reactive oxygen species in adult dermal fibroblasts. Furthermore, D-galactose increased the mRNA expression of p16, p21, and p53. The fetal dermal mesenchymal stem cell-conditioned medium improved the above-mentioned effects. Overall, fetal dermal mesenchymal stem cells exerted anti-aging effects against adult dermal fibroblasts induced by D-galactose via paracrine functions.
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Envejecimiento , Dermis/embriología , Fibroblastos/fisiología , Células Madre Mesenquimatosas/fisiología , Adulto , Envejecimiento/efectos de los fármacos , Envejecimiento/fisiología , Animales , Apoptosis , Western Blotting , Senescencia Celular/efectos de los fármacos , Medios de Cultivo , Dermis/citología , Fibroblastos/efectos de los fármacos , Galactosa/farmacología , Humanos , Masculino , Especies Reactivas de Oxígeno/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa InversaRESUMEN
BACKGROUND: Foreign body(FB) ingestion in the upper digestive tract is a common emergency that lacks sufficient attention in adult population. Improper management may bring additional injuries and financial burdens to patients. This review was performed to determine the clinical characteristics of upper gastrointestinal FBs, including the demographic of adult patients, the type and location of FBs, underlying diseases of patients and other risk factors, and outcomes. METHODS: We searched PubMed, MEDLINE, EMBASE and Cochrane databases with the terms "foreign body AND upper gastrointestinal NOT child". Finally, we got 7 articles between 2001 and 2020 and extracted the information. RESULTS: A total of 1391 patients were included. 736 (52.9%) patients were males and 655 (47.1%) were females. Fish bone was the most common type of FBs. Esophagus accounts for the most location in the upper digestive tract. 18.2% (235/1291) patients had the underlying diseases, and 11.7% (58/494) had other risk factors. The overall complication rate was 4.5% (63/1391).
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Servicio de Urgencia en Hospital , Cuerpos Extraños/diagnóstico , Cuerpos Extraños/etiología , Tracto Gastrointestinal Superior , Adulto , Humanos , Factores de RiesgoRESUMEN
The fatality rate of traumatic cardiac arrest (TCA) is extremely high, and it is very different from that of non-traumatic cardiac arrest (NTCA) in resuscitation strategy. Only when the standard resuscitation process is combined with rapid treatment of various reversible causes can the mortality rate of patients be decreased. In this paper, the key factors leading to TCA are reviewed, such as hypovolemic shock, asphyxia, tension pneumothorax, pericardial tamponade, crush syndrome, craniocerebral injury, cerebral hernia, and the control measures are elaborated respectively, so as to provide references for clinical treatment of patients with severe trauma, and reduce TCA incidence and mortality.
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Paro Cardíaco , Neumotórax , Humanos , Incidencia , ResucitaciónRESUMEN
Fetal dermal mesenchymal stem cells (FDMSCs), isolated from fetal skin, are serving as a novel MSC candidate with great potential in regenerative medicine. More recently, the paracrine actions, especially MSC-derived exosomes, are being focused on the vital role in MSC-based cellular therapy. This study was to evaluate the therapeutic potential of exosomes secreted by FDMSCs in normal wound healing. First, the in vivo study indicated that FDMSC exosomes could accelerate wound closure in a mouse full-thickness skin wound model. Then, we investigated the role of FDMSC-derived exosomes on adult dermal fibroblast (ADFs). The results demonstrated that FDMSC exosomes could induce the proliferation, migration, and secretion of ADFs. We discovered that after treatment of exosomes, the Notch signaling pathway was activated. Then, we found that in FDMSC exosomes, the ligands of the Notch pathway were undetectable expect for Jagged 1, and the results of Jagged 1 mimic by peptide and knockdown by siRNA suggested that Jagged 1 may lead the activation of the Notch signal in ADFs. Collectively, our findings indicated that the FDMSC exosomes may promote wound healing by activating the ADF cell motility and secretion ability via the Notch signaling pathway, providing new aspects for the therapeutic strategy of FDMSC-derived exosomes for the treatment of skin wounds.
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Background: Malignant melanoma is the most lethal form of cutaneous tumor and has a high metastatic rate and motility capacity. Owing to the poor prognosis, it is urgent to seek an effective therapeutic regimen. Human mesenchymal stem cells (MSCs) can home to tumor cells and have been shown to play important roles in both promoting and inhibiting tumor development. Fetal dermal MSCs (FDMSCs), derived from fetal skin are a novel source of MSCs. Nevertheless, the antitumor capacity of FDMSCs on malignant melanoma is not clearly understood. Materials and methods: FDMSCs were extracted from the dorsal skin of fetal tissues. A375 melanoma cells lines were obtained from American Type Culture Collection. The effects of conditioned media from FDMSCs (CM-FDMSC) on A375 melanoma cells were tested in vivo using tumor formation assay and in vitro using cell viability, 5-ethynyl-2'-deoxyuridine incorporation, flow cytometry, TdT-mediated dUTP Nick-End Labeling (TUNEL), wound healing, transwell invasion, and Western blotting. Results: CM-FDMSC inhibited A375 tumor formation in vivo. In vitro, CM-FDMSC inhibited the tumor-related activities of A375 melanoma cells, as evidenced reductions in viability, migration, and invasion. CM-FDMSC-treated A375 cells showed decreased phosphatidylinositol 3-kinase (PI3K), protein kinase B (AKT), and extracellular signal-regulated kinase (ERK) phosphorylation, and up-regulation of Bcl-2-Associated X (BAX) and down-regulation of B-cell lymphoma-2 (BCL-2) expression. Conclusion: CM-FDMSC can inhibit the tumor-forming behaviors of A375 melanoma cells and inhibit PI3K/AKT and mitogen-activated protein kinase signaling to shift their BCL-2/BAX ratio toward a proapoptotic state. Identification of the bioactive components in CM-FDMSC will be important for translating these findings into novel therapies for malignant melanoma.
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It is the basic task of burn therapy to cover the wound with self-healthy skin timely and effectively. However, for patients with extensive burns, autologous skin is usually insufficient, and allogenic or heterogeneous skin leads to strong immune response. It is vital to choose an appropriate treatment for deep extensive burns. Nowadays, the dermal substitute combined with bone marrow mesenchymal stem cells (BM-MSCs) is a prospective strategy for burn wound healing. Denatured acellular dermal matrix (DADM), as one of dermal substitutes, which prepared by burn skin discarded in escharotomy, not only maintains a certain degree of 3D structure of collagen, but also has good biocompatibility. In this study, the preparation method of DADM was improved and DADM was seeded with BM-MSCs. Then BM-MSCs-seeded DADM (DADM/MSCs) was implanted into mice cutaneous wound, and the effect of DADM/MSCs dermal substitute was assessed on skin regeneration. As a result, BM-MSCs survived well and DADM/MSCs scaffolds significantly promoted wound healing in terms of angiogenesis, re-epithelialization and skin appendage regeneration. DADM/MSCs scaffold may represent an alternative promising therapy for wound healing in deep extensive burns.
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Dermis Acelular , Quemaduras/terapia , Trasplante de Células Madre Mesenquimatosas/métodos , Neovascularización Fisiológica , Repitelización , Trasplante de Piel/métodos , Animales , Células de la Médula Ósea , Proliferación Celular , Supervivencia Celular , Células Madre Mesenquimatosas , Ratones , Microscopía Electrónica de Rastreo , Cicatrización de HeridasRESUMEN
BACKGROUND: Skin flap-like wounds are common. These wound flaps are prone to avascular necrosis with simple debrided and sutured, and postoperative hyperplastic scarring and contracture of wound surfaces can adversely affect the patient's appearance. Here, we evaluate the data of cases with flap-like wounds to identify the causes of flap necrosis. METHODS: Six hundred patients with skin flap-like wounds between January 1, 2013 and December 31, 2016 were retrospectively reviewed. Their age, sex, injury reason, size of flap, length-width ratio of wound, thickness of pedicle, operation time, injury site, direction of blood perfusion in the flap and operating methods were recorded. The risks for flap necrosis were analyzed with one-factor analysis. RESULTS: A total success rate of 92.5% (555/600) for flap-like wound reconstruction was obtained. Among 67 flaps with vascular crisis, 22 were salvaged by subcutaneous injection of anisodamine, selective suture removal, and pressure dressing with elastic bandages. For the 45 patients with flap necrosis, there was no significant difference from patients without necrosis in terms of sex, age, and size of flap (Pâ¯>â¯0.05). The incidence of flap necrosis was significantly different in terms of injury reason, length-width ratio of wound, thickness of pedicle, operation time, injury site, direction of blood perfusion in the flap and operating methods (Pâ¯<â¯0.05). CONCLUSION: Injury reason, length-width ratio of wound, thickness of pedicle, operation time, injury site, direction of blood perfusion in the flap and operating methods, rather than age, sex and size of flap, were significant risk factors for necrosis of flap-like wounds.
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Necrosis/prevención & control , Procedimientos de Cirugía Plástica/métodos , Traumatismos de los Tejidos Blandos/cirugía , Técnicas de Sutura , Adulto , Desbridamiento/métodos , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Factores de Riesgo , Colgajos Quirúrgicos/irrigación sanguínea , Colgajos Quirúrgicos/cirugíaRESUMEN
BACKGROUND Mesenchymal stem cells (MSCs) have the potential of self-renewal and multi-differentiation and have a wide application prospect in organ transplantation for the effect of inducing immune tolerance. It has found that interleukin 17 (IL-17) could enhance the inhibition effect of MSCs on T cell proliferation and increase the immunosuppressive effect of MSCs. In this study, we aimed to investigate the effect of IL-17-induced MSCs on allograft survival time after transplantation. MATERIAL AND METHODS BMSCs were characterized by differential staining. The allogenic skin transplantations were performed and the BMSCs pre-treated by IL-17 were injected. To assess the immunosuppressive function of IL-17-induced BMSCs, the morphology of the grafts, the homing ability of the BMSCs, and the survival time of the grafts were analyzed. RESULTS BMSCs from BALB/c have multidirectional differentiation potential to differentiate into osteogenic, chondrogenic, and adipogenic lineage cells. IL-17-induced BMSCs prolonged the survival time of allogeneic skin grafts dramatically. We found that there were more labeled MSCs in the skin grafts, and the Treg subpopulations percentage, IL-10, and TGF-ß were significantly increased, while the IFN-γ level was decreased compared to the control group and MSCs group. In conclusion, IL-17 can enhance the homing ability of MSCs and regulate the immunosuppressive function of MSC. CONCLUSIONS Our data demonstrate that IL-17 plays the crucial role in MSC homing behaviors and promotes immunosuppression of MSCs during transplantation procedures, suggesting that IL-17-pre-treated MSCs have potential to prolong graft survival and reduce transplant rejection.
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Proliferación Celular/efectos de los fármacos , Supervivencia de Injerto/efectos de los fármacos , Interleucina-17/farmacología , Trasplante de Células Madre Mesenquimatosas/métodos , Células Madre Mesenquimatosas/efectos de los fármacos , Trasplante de Piel/métodos , Linfocitos T/efectos de los fármacos , Animales , Supervivencia de Injerto/inmunología , Células Madre Mesenquimatosas/inmunología , Ratones , Linfocitos T/inmunologíaRESUMEN
BACKGROUND: A large number of anthropometric studies of the auricle have been reported in different nations, but little data were available in the Chinese population. The aim of this study was to analyze growth changes in the ear by measuring the width and length of ears in a Chinese population. METHODS: A total of 480 participants were enrolled and classified into 1-, 3-, 5-, 7-, 9-, 12-, 14-, and 18-year groups (half were boys and half were girls in each group). Ear length, ear width, body weight, and body length were measured and recorded; ear index was calculated according to ear length and ear width. The growth of auricle and differences between genders were analyzed. Growth of ear in relation to body height and weight and the degree of emphasis on the length and width of the auricle were also analyzed. RESULTS: Ear length and width increased with age. Ear length achieved its mature size in both 14-year-old males and females. Ear width reached its mature size in males at 7 years and in females at 5 years. Different trends of ear index were shown between males and females. People in this population paid more attention to the length than the width of the auricle. CONCLUSIONS: The data indicated that ear development followed increase in age. There were gender and ethnic difference in the development of ear. These results may have potential implications for the diagnosis of congenital malformations, syndromes, and planning of ear reconstruction surgery.
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Antropometría/métodos , Pabellón Auricular/crecimiento & desarrollo , Adolescente , Niño , Preescolar , China , Femenino , Humanos , Lactante , MasculinoRESUMEN
The regenerative repair of deepdegree (second degree) burned skin remains a notable challenge in the treatment of burn injury, despite improvements being made with regards to treatment modality and the emergence of novel therapies. Fetal skin constitutes an attractive target for investigating scarless healing of burned skin. To investigate the inflammatory response during scarless healing of burned fetal skin, the present study developed a nude mouse model, which was implanted with normal human fetal skin and burned fetal skin. Subsequently, human peripheral blood mononuclear cells (PBMCs) were used to treat the nude mouse model carrying the burned fetal skin. The expression levels of matrix metalloproteinase (MMP)9 and tissue inhibitor of metalloproteinases (TIMP)1 were investigated during this process. In the present study, fetal skin was subcutaneously implanted into the nude mice to establish the murine model. Hematoxylin and eosin staining was used to detect alterations in the skin during the development of fetal skin and during the healing process of deepdegree burned fetal skin. The expression levels of MMP9 and TIMP1 were determined using immunochemical staining, and their staining intensity was evaluated by mean optical density. The results demonstrated that fetal skin subcutaneously implanted into the dorsal skin flap of nude mice developed similarly to the normal growth process in the womb. In addition, the scarless healing process was clearly observed in the mice carrying the burned fetal skin. A total of 2 weeks was required to complete scarless healing. Following treatment with PBMCs, the burned fetal skin generated inflammatory factors and enhanced the inflammatory response, which consequently resulted in a reduction in the speed of healing and in the formation of scars. Therefore, exogenous PBMCs may alter the lowered immune response environment, which is required for scarless healing, resulting in scar formation. In conclusion, the present study indicated that the involvement of inflammatory cells is important during the healing process of deepdegree burned skin, and MMP9 and TIMP1 may serve important roles in the process of scar formation.