Gout-associated uric acid crystals induce tophi ulcerations and impair wound healing in a novel gouty ulcer model.

This study aimed to establish a novel gouty ulcer rat model induced by monosodium urate (MSU) deposition and preliminarily explored how MSU crystals affected wound healing. MSU crystals were subcutaneously injected into the back of rats to simulate tophi formation and ulceration. Ultrasound was used to detect the formation of gouty tophi. MSU crystal deposition and histopathological changes were analysed by haematoxylin-eosin staining. After the skin over the tophi became broken in the model group, a full-thickness tissue defect of the same area was made on the backs of the phosphate buffered saline (PBS) controls. On Days 3, 7, and 14 after wounding, the infiltration of neutrophils and macrophages and the expression of inflammatory markers, including interleukin-1ß (IL-1ß), tumour necrosis factor-α (TNF-α), and Nod-like receptor protein 3 (NLRP3), were examined by immunohistochemical staining and Western blotting, respectively. After the first subcutaneous injection in rats, local tissues showed redness and swelling, indicating inflammation on approximately Day 14. Tophi-like manifestations appeared on approximately Day 18. Tophi appeared heterogeneously hyperechoic by ultrasound. Swelling and redness in injured tissue areas increased on approximately Day 22, skin tissue necrosis was seen in a small area on approximately Day 26, and skin necrosis was enlarged and the tophi were ulcerated on approximately Day 32, accompanied by yellowish-white, chalky secretions. Haematoxylin and eosin staining showed dermal deposition of needle-like crystals with surrounding granulomatous inflammation. On Days 3, 7, and 14 after wounding, immunohistochemical staining showed the infiltration of neutrophils and macrophages, and the expression of inflammation-related proteins (IL-1ß, TNF-α, and NLRP3) were upregulated in gouty ulcers compared with those of PBS controls. The gouty ulcers were not completely healed by Day 14 compared with those in the PBS controls. In this study, a novel gouty ulcer rat model was constructed, which also revealed the existence of persistent chronic inflammation.

Foamy macrophages potentially inhibit tuberculous wound healing by inhibiting the TLRs/NF-κB signalling pathway.

To characterise the distribution, classification, and quantity of foamy macrophages (FMs) in tuberculous wound tissue and the relationship between FM and delayed healing of tuberculous wounds. Morphological studies were performed to explore the distribution of FM and Mycobacterium tuberculosis (Mtb) in tuberculous wounds, with acute and chronic wounds included for comparison. Phorbol-12-myristate-13-acetate stimulation-differentiated THP-1 cells were treated with Mtb to induce their differentiation into FM with oxidised low-density lipoprotein treatment serving as a control. Relative cytokine levels were determined by quantitative PCR and Western blotting. Varied co-culture combinations of Mtb, THP-1, FM, and fibroblasts were performed, and proliferation, migration, ability to contract collagen gel, and protein levels of the chemokines in the supernatants of the fibroblasts were assessed. The differentially expressed genes in human skin fibroblasts (HSFs) after co-culture with or without FM were identified using microarray. Many FM were found in the tissues of tuberculous wounds. The FM that did not engulf Mtb (NM-FM) were mainly distributed in tissues surrounding tuberculous wounds, whereas the FM that engulfed Mtb (M-FM) were dominantly located within granulomatous tissues. Co-culture experiments showed that, with the Mtb co-culture, the portions of NM-FM in the total FM grew over time. The migration, proliferation, chemokine secretion, and the ability of fibroblasts to contract collagen gel were inhibited when co-cultured with Mtb, FM, or a combination of the two. Further investigation showed that the TLRs/NF-κB signalling pathway is involved in fibroblast function under the stimulation of FM. TLRs and NF-κB agonists could reverse the phenotypic changes in HSFs after co-culture with FM. The tuberculous wound microenvironment composed of Mtb and FM may affect wound healing by inhibiting the functions of fibroblasts. FM potentially inhibit fibroblasts' function by inhibiting the TLRs/NF-κB signalling pathway in tuberculous wounds.

Application of Various Methods to Evaluate the Postoperative Characteristics of Expanded Pedicled Deltopectoral Flap for Large Facial Scars.

ABSTRACT: The expanded pedicled deltopectoral flap (EPDF) has been widely used to repair large facial scars. Although doctors and patients are usually satisfied with the outcomes, the actual functional recovery and cosmetic effects of EPDF are still unknown. It is, therefore, necessary to objectively investigate the effect of transferred EPDF by using a variety of methods. From January 2008 to December 2018, 52 patients who underwent EPDF surgery at Xijing Hospital were enrolled. Sense of touch, static 2-point discrimination, elasticity, and color were measured. Thermesthesia and algesthesia were also tested. Postoperative scars were evaluated using the patient and observer scar assessment scale. Satisfaction of patients, doctors, and laypersons was investigated. The algaesthesis, thalposis, and rhigosis scores were 4.7 ±â€Š0.7, 3.7 ±â€Š0.9, and 4.5 ±â€Š0.8, respectively. The tactile score was 0.3 ±â€Š0.2 mN, and 2-point discrimination was 10.1 ±â€Š4.8 mm. L ∗ , a ∗ hemoglobin, and melanin content of the flaps were significantly different when compared with normal skin ( P   <  0.05). The satisfaction of doctors, patients, and laypersons was 88.5%, 71.2%, and 67.3%, respectively. The higher satisfaction of patients was mainly associated with the smaller color difference between the flap and the surrounding skin, and lower patient and observer scar assessment scale score. These results confirm that excellent functional recovery and reliable cosmetic effects are observed when facial scars are repaired with EPDF. The methods used in this study can be applied to the evaluation of functional recovery and cosmetic outcomes of transferred flaps, which may provide a more comprehensive understanding of flap assessment.

Comparison of 1565-nm Nonablative Fractional Laser and 10600-nm Ablative Fractional Laser in the Treatment of Mild to Moderate Atrophic Acne Scars.

BACKGROUND: The 10,600-nm ablative fractional laser (AFL) is widely used for treating facial atrophic acne scars but with evident side effects. By contrast, the common Er:Glass non-AFL (NAFL) is safer but lacks of comparable outcomes. A novel 1,565 nm Er:Glass NAFL improves thermal energy delivery and could yield better outcomes. OBJECTIVE: We aimed to compare the effectiveness and safety between the 1,565-nm NAFL and 10,600-nm AFL in treating mild-to-moderate facial atrophic acne scars. METHODS: Nineteen patients with mild-to-moderate bilateral facial atrophic acne scars were enrolled in a randomized split-face trial, which involved 3-session procedures for each laser. The effectiveness and safety were evaluated by doctors and patients who were blinded to the treatment assignment. RESULTS: Both lasers improved the acne scar profiles comparably. A marked reduction in erythema, crusting durations, and degree of pain were noted on the sides treated with the 1,565-nm NAFL, relative to those treated with the 10,600-nm AFL. CONCLUSION: Both 1,565 nm-NAFL and 10,600-nm AFL can improve mild-to-moderate acne scars. Patients should never expect complete resolution. The 1,565-nm NAFL has less side effects.

Inhibition of Notch Intracellular Domain Suppresses Cell Activation and Fibrotic Factors Production in Hypertrophic Scar Fibroblasts Versus Normal Skin Fibroblasts.

BACKGROUND: Hypertrophic scar (HS) is the most common complication after skin injury with unknown etiopathogenesis. There is increasing evidence to suggest that aberrant Notch signaling contributes directly to skin pathogenesis and altered expression of the Notch intracellular domain (NICD) identified in HS. Therefore, the aim of this study was to investigate the effects of Notch signaling pathway in HS pathogenesis. METHODS: Hypertrophic scar and normal skin samples were collected. Notch intracellular domain expression was detected by immunohistochemistry staining and fibroblasts were separated from the samples. We compared fibrotic factors production, cell viability, migration and apoptosis of HS fibroblasts (HFB) versus normal skin fibroblasts (NFB) by real time quantitative polymerase chain reaction, MTS, cell scratch assay and flow cytometry respectively under the impact of inhibition of Notch signaling by NICD-small-interfering RNA (SiRNA). RESULTS: The results showed that NICD was overexpressed in the dermis of HS tissues. Inhibition of Notch signaling by NICD-SiRNA suppressed the production of the fibrotic factors including collagen 1, collagen 3, α-SMA, and TGF-ß1 by HFB and NFB. Cell viability and migration were reduced in NICD-SiRNA-treated NFB and HFB, whereas cell apoptosis was enhanced by NICD-SiRNA. CONCLUSIONS: Conclusively, the study demonstrates a potential role for Notch signaling in HS progression, and targeting this pathway may provide a novel strategy for treatment of HS.

Ureteral anastomosis with a polyimide stent in rat kidney transplantation.

Background: Complications associated with ureteral anastomosis in kidney transplantation are highly prevalent, despite the development of various types of stents. The current stent materials and placement methods have several limitations. This study attempts to provide an alternative by investigating ureteral anastomosis with a polyimide stent and a modified placement method in a rat model of kidney transplantation.Methods: Sprague-Dawley rats were randomly divided into Group I: sham operation, Group II: autologous ureteral anastomosis, and Group III: isogenic kidney transplantation with ureteral anastomosis. For the anastomosis, a polyimide stent with a previously placed 11-0 silk was inserted into the ureter. The stent and ureter were fixed with 11-0 silk sutures. The kidney weight and serum creatinine were recorded. The ureteral and renal sections were taken for histological analysis.Results: None of the stents had migrated. Urethral patency was achieved. Further, there were no evident histological changes in the anastomosed ureters. The serum creatinine level in group III was significantly higher than the other two groups, but there was no significant difference in kidney weight among the groups at postoperative week 12. Finally, the histological structure of kidneys in groups II and III only showed minor changes.Conclusions: The current anastomosis method with polyimide stent causes minimal damage to the ureteral walls and minimizes the possibility of stent migration. Therefore, this method of ureteral anastomosis with the polyimide stent should be explored for its potential benefits in more animal kidney transplantation models, thus providing an alternative for the clinical setting.

A Randomized, Controlled Study Comparing Subbrow Blepharoplasty and Subbrow Blepharoplasty Combined with Periorbital Muscle Manipulation for Periorbital Aging Rejuvenation in Asians.

BACKGROUND: Improving periorbital aging is, currently, of great concern. The previous literature has reported some surgical methods for periorbital aging. The purpose of this study was to compare subbrow blepharoplasty (SBB) with subbrow blepharoplasty combined with periorbital muscle manipulation (SBB-pm) with regard to improving periorbital aging. METHODS: A prospective, randomized, controlled study was designed to evaluate and compare the effects of two different surgical techniques on upper lid relaxation, brow shape and periorbital wrinkles. Patients were divided into two groups. Group 1 underwent resection of excess skin; group 2 underwent a modified technique that involved resection of an elliptical island of skin, separation of the corrugator supercilii muscle and dissection of the orbicularis oculi muscle, followed by suturing it to the orbital periosteum and cross-fixation with itself. The upper eyelid and eyebrow height, periorbital wrinkle score and patient satisfaction were measured preoperatively and postoperatively. RESULTS: This study included 70 patients (140 eyes). At 1 month, 3 months, 6 months and 12 months after surgery, group 2 was superior to group 1 with regard to the improvement in upper eyelid relaxation at the medial limbus, middle pupil and lateral canthus. The eyebrow assumed a low and flat appearance in group 1. The eyebrow showed a low and flat appearance and then returned to the preoperative level in group 2. When comparing the two surgical techniques, the authors found statistically significant differences in regard to changes in crow's feet and glabellar frown lines. Two patients in group 2 experienced forehead numbness after surgery, which resolved by the 6-month follow-up. Patients in group 2 were significantly more satisfied with their surgery than patients in group 1. CONCLUSION: SBB-pm is more effective than SBB for improving upper eyelid relaxation and preventing secondary brow ptosis after surgery as well as for alleviating periorbital wrinkles, although it is accompanied by transient forehead numbness. LEVEL OF EVIDENCE II: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266.

Fatal Cerebral Infarction and Ophthalmic Artery Occlusion After Nasal Augmentation with Hyaluronic Acid-A Case Report and Review of Literature.

BACKGROUND: Cerebral infarction is a rare complication of hyaluronic acid (HA) filler injection, usually presenting with sudden increase in intracranial pressure and loss of vision. METHODS: A 40-year-old Asian woman in a coma was transferred to the emergency intensive care unit of Xijing Hospital, China, 48 h after nasal augmentation with HA. Magnetic resonance imaging indicated cerebral infarction and left optic nerve edema and ischemia. Magnetic resonance angiography did not reveal vessel embolism. RESULTS: The patient developed gastric ulceration, pulmonary infection, respiratory failure, and cerebral herniation, and died 6 days after the HA filler injection. CONCLUSION: Facial cosmetic HA filler injection can cause devastating and even fatal complications. LEVEL OF EVIDENCE V: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266.

Circ_0075932 in adipocyte-derived exosomes induces inflammation and apoptosis in human dermal keratinocytes by directly binding with PUM2 and promoting PUM2-mediated activation of AuroraA/NF-κB pathway.

It remains unclear why obese persons displayed a slower wound healing rate than the normal. In this study, we found that has_circ_0075932, a single-exon circular RNA, was outstandingly expressed in human normal adipose tissue and overexpressed in burned skin of obese persons compared with that of non-obese persons. Circ_0075932 overexpression or silencing in dermal keratinocytes had no obvious effect on cell behaviors, unless dozens of times overexpression, since its basal expression level in keratinocytes is too low. However, the exosome released from circ_0075932-overexpressing adipocytes displayed a significantly promoting effect on inflammation and apoptosis in dermal keratinocytes. Then, in our mechanism exploration, we found that circ_0075932 directly bound with the RNA-binding protein PUM2, which was reported to positively regulated AuroraA kinase, thus activating the NF-κB pathway. Moreover, either silencing PUM2, silencing AuroraA, or blockade of NF-κB activation, could abrogate the promoting effect of adipocyte-derived exosomal circ_0075932 on cell inflammation and apoptosis.

Macrophages are necessary for skin regeneration during tissue expansion.

BACKGROUND: Tissue expansion is a procedure that promotes skin regeneration by mechanical stretch. During the stress and relaxation cycle, the skin undergoes a repeated microtrauma which triggers an immune response leading to the recruitment of macrophages to repair the damaged tissue. Macrophages have been found to be necessary for tissue repair and wound healing, but their effects on skin regeneration during mechanical stretch remain unclear. METHODS: The dynamic changes of macrophages in the rat skin tissues undergoing expansion were quantitatively determined by immunohistochemistry staining. The area of the expanded skin, skin thickness, dermal collagen density, cell proliferation and tissue vascularization were examined to determine the effects of macrophages on the expanding skin. The phenotypes of macrophages and the growth factors related to skin regeneration were also examined to evaluate the underlying mechanisms for the involvement of macrophages in skin regeneration. As a comparison, the tissue samples of expanding skin in which the macrophages were depleted by topically utilizing clodronate liposomes were also evaluated. RESULTS: The number of skin macrophages in skin maintained in the high level during the skin expansion compared to non-expanded skin. We found that a switch from an M1- to M2-dominant response during tissue expansion. After the macrophages were depleted, the skin regeneration was inhibited, as evidenced by a smaller expansion area, thinner skin layers and decreased cell proliferation rate, collagen synthesis and, skin vascularization. The secretion of epidermal growth factor (EGF), fibroblast growth factor (FGF), and vascular endothelial growth factor (VEGF) were decreased when macrophages were depleted. CONCLUSIONS: Our findings suggest that macrophages are necessary for skin regeneration during tissue expansion. Modulating inflammation may provide a key therapeutic strategy to promote skin growth under mechanical strain.

Conventional Nanofat and SVF/ADSC-Concentrated Nanofat: A Comparative Study on Improving Photoaging of Nude Mice Skin.

BACKGROUND: Nanofats could improve photoaging. Stromal vascular fraction (SVF) and adipose-derived stem cells (ADSCs) may play pivotal roles. However, SVFs and ADSCs in nanofats processed by conventional methods cannot be enriched. Some researchers have found that after centrifugation, the SVF/ADSC density increases from top to bottom. OBJECTIVES: The authors hypothesized that centrifugation can be used to obtain SVF/ADSC-concentrated nanofats that are superior to conventional nanofats in improving the photoaging of skin. METHODS: After a photoaging model was successfully established in nude mice, the back of each mouse was divided into 4 areas and randomly injected with conventional nanofat, centrifuged nanofat (either the middle or lower layer of centrifuged nanofat), or normal saline. Wrinkles, dermis thickness, dermal collagen content, and elastic fiber morphology were measured and compared at weeks 4 and 8. RESULTS: Compared with the wrinkles in the physiological saline injection areas, the wrinkles in the areas injected with the 3 nanofats (lower and middle layers of centrifuged nanofat and conventional nanofat) were significantly reduced. All 3 nanofat groups showed increased dermal thickness, increased collagen content, and a more regular distribution of elastic fibers compared with the saline injection areas. CONCLUSIONS: The study established the efficacy of nanofats in improving photoaging by reducing wrinkles and increasing the thickness of dermal collagen, making nanofats a promising novel treatment for photoaging. The SVF/ADSC-concentrated nanofats exhibited the most improvement.

Improving the Retention Rate of Fat Grafts in Recipient Areas via Botulinum Toxin A Treatment.

BACKGROUND: Improving the retention rate of transplanted fat is, currently, of great concern. Partial immobilization, angiogenesis, and adipose tissue-derived stem cells, all proven to be influenced by botulinum toxin A (BTX-A), are significant in fat graft retention. OBJECTIVES: The authors sought to determine the impact of BTX-A on fat grafts. METHODS: Our study included 12 Sprague Dawley rats and each rat's hind limbs were randomly designated as the BTX-A side and control side. We injected 0.2 mL of BTX-A-treated fat into the quadriceps femoris and subcutaneous space of the BTX-A sides. This was also done for the control sides but with untreated fat. We performed electroneuromyography of recipient muscles at 1 week post-operation. The rats were euthanized at 12 weeks post-operation and we observed the fat retention rate, the fat's histologic characteristics, and the density of vessels and mature adipocytes. RESULTS: The amplitudes of electroneuromyography were smaller for the BTX-A sides than the control sides. For intramuscularly injected fat, the BTX-A sides had better retention rates and histologic characteristics and a higher density of vessels and mature adipocytes than the control sides. For subcutaneously injected fat, the BTX-A sides had better histologic characteristics and a higher density of vessels and mature adipocytes than the control sides, but the retention rates were not significantly different between the 2 sides. CONCLUSIONS: Injecting BTX-A-treated fat grafts can immobilize the surrounding muscles. BTX-A can improve the density of vessels and mature adipocytes, histologic characteristics of fat grafts, and retention rate of fat grafts transplanted into muscles.

Current surgical practices of robotic-assisted tissue repair and reconstruction.

This paper systematically reviewed and analyzed the recent publications of robotic-assisted surgeries in the field of tissue repair and reconstruction. Surgical robots can elevate skin flap more accurately and shorten the time of tissue harvest. In addition, robotic-assisted surgery has the advantage of minimal tissue trauma and thus forms minimal scar. The utilization of surgical robots reduces the occurrence of complications after oral radical tumor resection while achieving cosmetic sutures. Robotic-assisted radical mastectomy could radically remove invasive breast cancer lesions and achieve breast reconstruction in the first stage through the small incisions in the operation areas. Surgical robots enable precise microvascular anastomosis and reduce tissue edema in the surgical field. Robotic-assisted technology can help appropriately locate the target tissues at different angles during sinus and skull base surgeries and accurately place tissues during urethroplasty. The robotic-assisted technology provides a new platform for surgical innovation in the field of tissue repair and reconstruction. However, the uncertainty in the survival rate after tumor radical surgery, the increase of operating time, and the high costs are barriers for its clinical application in tissue repair and reconstructive surgery. Nevertheless, robotic-assisted technology has already demonstrated an impact on the field of tissue repair and reconstruction in a meaningful way.

The clinical dynamic changes of macrophage phenotype and function in different stages of human wound healing and hypertrophic scar formation.

The pathogenesis of hypertrophic scar (HS) is still poorly understood. Macrophages, especially the polarisation of that to M1 or M2, play a pivotal role in control of the degree of scar formation. Profiling of macrophage phenotypes in human specimens during long-term period of wound healing and HS formation may provide valuable clinical evidence for understanding the pathology of human scars. Human wound and HS specimens were collected, the macrophage phenotype was identified by immunofluorescence, and biomarkers and cytokines associated with M1 and M2 macrophages were detected by RT-PCR. The correlation between the macrophage phenotype and HS characteristics was analysed by linear regression analyses. We found excessive and persistent infiltration by M1 macrophages around the blood vessels in the superficial layer of the dermis at early wound tissues, whereas M2 macrophages predominated in later wound tissues and the proliferative phase of HS and were scattered throughout the dermis. The density of M1 macrophages was positively correlated with mRNA expression levels of tumour necrosis factor-alpha (TNF-α) and IL-6. The density of M2 macrophages was positively correlated with ARG1 and negatively correlated with the duration of HS. The sequential infiltration by M1 macrophage and M2 macrophages in human wound and HS tissues was confirmed.

Blocking CD226 Promotes Allogeneic Transplant Immune Tolerance and Improves Skin Graft Survival by Increasing the Frequency of Regulatory T Cells in a Murine Model.

BACKGROUND/AIMS: Regulatory T cells (Tregs) play key roles in maintaining peripheral tolerance and preventing autoimmune disease. Treg modulation could be helpful in treating malignancies, autoimmune disease, and allergies, as well as to facilitate organ transplantation. Signals transduced by co-stimulatory molecules are essential for Treg differentiation, homeostasis, and function. One well-known active receptor, CD226, also known as DNAM-1 or PTA1, is an adhesion molecule that interacts primarily with CD155 and is involved in Treg differentiation and immune tolerance to transplanted tissue. METHODS: Anti-CD226 monoclonal antibody (mAb) and truncated recombinant CD226 proteins were employed to manipulate the CD226 signal. Various T cell markers on freshly isolated splenocytes and T lymphocytes were characterized by flow cytometry Cell proliferation was measured by carboxyfluorescein succinimidyl ester dye, mRNA transcripts by q-RT PCR, and protein expression by western blotting. A BALB/c-to-C57BL/6 skin allograft model was used to determine the effects of CD226 blocking treatment. RESULTS: We observed that both intact extracellular domains of CD226 were necessary for functional interaction of the receptor with its ligand CD155, even though one domain was shown to bind CD155 with lower affinity in a solid binding assay. Importantly, CD226 mAb promoted Treg expansion in a mixed lymphocyte culture and inhibited the cytotoxicity of effector cells. In allogeneic skin transplant mice, administering CD226 mAb reduced inflammation and prolonged allogeneic graft survival, with an increase in the frequency of Tregs. CONCLUSIONS: Our results reveal the mechanism underlying CD226-CD155 interactions and indicate that CD226 signals can be manipulated to promote Treg expansion. Moreover, we provide new evidence that suggests the therapeutic potential of anti-CD226 with allogeneic transplantation.

TIGIT-Fc alleviates acute graft-versus-host disease by suppressing CTL activation via promoting the generation of immunoregulatory dendritic cells.

Graft-versus-host disease (GVHD) is the most common complication and major limitation of allogeneic hematopoietic stem cell transplantation. The CD226/TIGIT-CD155 signal is critical for the cross-talk between T cells and dendritic cells (DCs). Studies have shown that blockade of the CD226-CD155 interaction, using an anti-CD226 antibody, can significantly ameliorate GVHD. It has also been reported that a TIGIT-Fc fusion protein exerts immunosuppressive effects by binding to CD155 on DCs. Here, we used a mouse allogeneic acute GVHD model to explore the therapeutic potential and mechanism of action of TIGIT-Fc. C57/BL6 and Balb/c mice were used as hematopoietic cell graft donors and recipients, respectively. In the TIGIT-Fc-treated mice, GVHD symptom occurrence and mortality were delayed compared to that in isotype control group mice. Histopathological analyses revealed that following TIGIT-Fc treatment, liver and small intestine tissue damage was reduced with minimal lymphocytic infiltration. The percentage of CD8+IFN-γ+ and CD8+ granzyme B+ cells significantly decreased in the TIGIT-Fc group. Moreover, treatment with TIGIT-Fc, even after the onset of GVHD, ameliorated symptoms and prolonged survival. TIGIT-Fc also inhibited CD8+ T cell activation in vitro; this was dependent on the presence of CD155 on bone marrow-derived dendritic cells (BMDCs) and on IL-10 production. In addition, TIGIT-CD155 ligation triggered both Erk phosphorylation and STAT3 nuclear translocation. These data indicate that TIGIT plays an important role in the development of GVHD and is an ideal molecular target to treat acute GVHD.

Effect of the vascularized bone components on the survival of vascularized composite allografts.

BACKGROUND: Vascularized composite allograft (VCA), such as hand and face allograft, contains a vascularized bone component that may provide an immunologic benefit and induce tolerance for the simultaneous inclusion of marrow cells and a marrow microenvironment. We developed a chimeric groin cutaneous/femur flap to investigate the effect of vascularized bone marrow on VCA survival and its ability to induce chimerism. METHODS: Brown Norway and Lewis rats were used as donors and recipients, respectively. The experimental groups were as follows: groin flap transplantation alone, flap plus intravenous donor bone marrow cells and flap plus simultaneous femur transplantation. Animals received a nonmyeloablative conditioning regimen that consisted of 7-Gy thymic irradiation, 0.75-mL antilymphocyte serum, and 8-mg-1kg-1d cyclosporine A. The flap survival time, peripheral blood chimerism, and the bone marrow of transplanted femurs were analyzed and compared between groups. RESULTS: Our data showed that the conditioning regimen was effective in T cell ablation. Simultaneous femur transplantation significantly prolonged the median flap survival time (78.8 ± 13.0 d, n = 8) compared with the intravenous bone marrow infusion group (60.9 ± 2.2 d, n = 7) and the control group (58.6 ± 1.3 d, n = 5). Peripheral blood chimerism of 5.81% ± 1.98% was persistently detected for 60 d in recipients of femur transplants but not in the other two groups. Viable bone marrow was confirmed within the transplanted femur on postoperative d 60, but it was gradually replaced by recipient origin cells and eventually developed rejection and fibrosis. CONCLUSIONS: Vascularized bone component plays some protective roles on VCA survival but fails to provide a continuous source of donor cells.

Transfusion of ethylene carbodiimide-fixed donor splenocytes prolongs survival of vascularized skin allografts.

BACKGROUND: Allograft rejection is a major obstacle to the widespread clinical application of vascularized composite allotransplantation. Recent studies revealed a noncytoreductive strategy to protect allografts by the transfusion of ethylene carbodiimide-fixed donor splenocytes (ECDI-SPs). To determine whether this approach offers advantages in protecting skin allografts, we examined the immunological protection of infusing ECDI-SPs with a 30-d administration of rapamycin on the skin allografts of mice. MATERIALS AND METHODS: C57BL/6 recipient mice received BALB/c donor full-thickness skin or vascularized skin transplants at day 0, along with the infusion of donor ECDI-SPs 7 d before and 1 d after allotransplantation and a 30-d course of rapamycin. Recipients received ECDI-untreated splenocytes or C3H allografts as controls. In vitro allostimulatory activity of ECDI-SPs and donor-specific ex vivo hyporesponsiveness were tested. Production of related cytokines (TGF-ß, IL-10, IL-1ß, and TNF-α) and expression of CD4+Foxp3+ regulatory T cells (Tregs) were also examined. RESULTS: Transfusion of ECDI-SPs combined with rapamycin significantly prolonged survival of full-thickness skin (median survival time [MST]: 28 d) and full-thickness skin allografts (MST: 71 d) compared with untreated splenocytes (MSTs: 11 d and 30 d) or C3H allografts (MSTs: 11 d and 38 d). This effect was accompanied by increased production of IL-10 and TGF-ß, decreased production of IL-1ß and TNF-α, and expansion of Tregs in vitro and in vivo. CONCLUSIONS: ECDI-SP infusion combined with short-term rapamycin administration provides a promising approach to prolong the skin allograft survival.

Inhibition of Lymphatic Drainage With a Self-Designed Surgical Approach Prolongs the Vascularized Skin Allograft Survival in Rats.

Vascularized composite allotransplantation (VCA) is an emerging treatment for significant tissue defects. However, VCAs usually consist of multiple highly antigenic skin tissues. Previous studies have shown that the lymphatic system in skin plays important roles in the initiation of immune responses during acute rejection, by transporting T cells and antigen-presenting dendritic cells to regional lymph nodes. Therefore, we designed a new surgical treatment to inhibit lymphatic drainage of skin allografts and investigated whether this approach could promote the survival of allografts and suppress immunological events after transplantation. This procedure was achieved by connecting the vascularized allografts to recipient tissues with only an annular plastic holder, allowing the minimum of allograft contact with recipients. Our results showed that the self-designed treatment for inhibiting lymphatic drainage promoted the survival of allografts, reduced the serum concentration of IL-2, and decreased the percentage of CD4CD25 and CD8CD25 from the lymphatic nodes draining the transplantation region. In conclusion, these data suggest that self-designed surgical approach is effective in inhibiting lymphatic drainage of skin allografts, and the lymphatic system may be new therapeutic targets for developing techniques or drugs against acute rejection after VCAs.

The Combination of Expanded Scalp Flap and 800 nm Diode Laser in the Reconstruction of Forehead Defect.

Skin grafting is often the first choice for closing forehead defects. However, the aesthetics of skin grafting-reconstructed forehead defects are still not accepted by a large number of patients. With the technological advancement of laser hair removal, scalp flaps have been considered as donors for reconstruction of forehead defects. We evaluated 10 cases of forehead defect reconstructions with expanded scalp flaps followed by hair removal by an 800 nm diode laser. All flaps survived uneventfully and underwent 4-6 laser treatments for hair removal. The appearances of the reconstructed foreheads were similar to that of the adjacent skin, and all patients were satisfied with the treatment outcomes during the 6-24 months of follow-up. It is concluded that the combined treatments of expanded scalp flaps and diode laser hair removal are effective for repairing forehead defects.Level of Evidence IV This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .