Altered actin dynamics is possibly implicated in the inhibition of mechanical stimulation-induced dermal fibroblast differentiation into myofibroblasts.

The formation of hypertrophic scars and keloids is strongly associated with mechanical stimulation, and myofibroblasts are known to play a major role in abnormal scar formation. Wounds in patients with neurofibromatosis type 1 (NF1) become inconspicuous and lack the tendency to form abnormal scars. We hypothesized that there would be a unique response to mechanical stimulation and subsequent scar formation in NF1. To test this hypothesis, we investigated the molecular mechanisms of differentiation into myofibroblasts in NF1-derived fibroblasts and neurofibromin-depleted fibroblasts and examined actin dynamics, which is involved in fibroblast differentiation, with a focus on the pathway linking LIMK2/cofilin to actin dynamics. In normal fibroblasts, expression of α-smooth muscle actin (α-SMA), a marker of myofibroblasts, significantly increased after mechanical stimulation, whereas in NF1-derived and neurofibromin-depleted fibroblasts, α-SMA expression did not change. Phosphorylation of cofilin and subsequent actin polymerization did not increase in NF1-derived and neurofibromin-depleted fibroblasts after mechanical stimulation. Finally, in normal fibroblasts treated with Jasplakinolide, an actin stabilizer, α-SMA expression did not change after mechanical stimulation. Therefore, when neurofibromin was dysfunctional or depleted, subsequent actin polymerization did not occur in response to mechanical stimulation, which may have led to the unchanged expression of α-SMA. We believe this molecular pathway can be a potential therapeutic target for the treatment of abnormal scars.

Head and Neck Reconstruction With 2-Stage External Pectoralis Major Myocutaneous Flap Transfer.

BACKGROUND: In head and neck surgery cases where skin is severely scarred or adhered to surrounding tissue, reconstruction can be difficult to perform using microsurgical tissue or conventional pedicled pectoralis major myocutaneous flap (PMMF) transfer given the risks, which include damage to major vessels when manipulating scarred skin. For such cases, we perform a 2-stage external PMMF transfer, whereby the PMMF is directly sutured to the defect over the neck skin (without manipulation the hardened skin), and the flap division is then performed secondarily. METHODS: A total of 30 patients who had histories of radiotherapy (60-70 Gy) and prior neck dissection received the 2-stage external PMMF transfer procedure. Indications for the flaps included pharyngeal fistula closure in 12 patients, reconstruction for mandibular necrosis after radiotherapy in 8 patients, salvage surgery for partial or total necrosis of the free flap in 4 patients, and simultaneous reconstruction after tumor excision in 6 patients. Two patients underwent a second external PMMF transfer from the contralateral side because of postoperative complications, yielding a total of 32 flap transfers. RESULTS: Twenty-nine flaps showed complete flap survival, whereas 3 had partial necrosis. Other complications, despite complete flap survival, included large fistulas requiring additional surgery for fistula closure (1 patient) and small fistulas that were closed without requiring reoperation (7 patients). CONCLUSIONS: External PMMF transfer offers a safe, simple, and effective option in cases where free flap surgery is considered difficult or the risks associated with neck manipulation are high.

Personal Computer-Based Cephalometric Landmark Detection With Deep Learning, Using Cephalograms on the Internet.

BACKGROUND: Cephalometric analysis has long been, and still is one of the most important tools in evaluating craniomaxillofacial skeletal profile. To perform this, manual tracing of x-ray film and plotting landmarks have been required. This procedure is time-consuming and demands expertise. In these days, computerized cephalometric systems have been introduced; however, tracing and plotting still have to be done on the monitor display. Artificial intelligence is developing rapidly. Deep learning is one of the most evolving areas in artificial intelligence. The authors made an automated landmark predicting system, based on a deep learning neural network. METHODS: On a personal desktop computer, a convolutional network was built for regression analysis of cephalometric landmarks' coordinate values. Lateral cephalogram images were gathered through the internet and 219 images were obtained. Ten skeletal cephalometric landmarks were manually plotted and coordinate values of them were listed. The images were randomly divided into 153 training images and 66 testing images. Training images were expanded 51 folds. The network was trained with the expanded training images. With the testing images, landmarks were predicted by the network. Prediction errors from manually plotted points were evaluated. RESULTS: Average and median prediction errors were 17.02 and 16.22 pixels. Angles and lengths in cephalometric analysis, predicted by the neural network, were not statistically different from those calculated from manually plotted points. CONCLUSION: Despite the variety of image quality, using cephalogram images on the internet is a feasible approach for landmark prediction.

Endothelial cell-derived endothelin-1 is involved in abnormal scar formation by dermal fibroblasts through RhoA/Rho-kinase pathway.

Hypertrophic scars and keloids are characterized by excessive dermal deposition of extracellular matrix due to fibroblast-to-myofibroblast differentiation. Endothelin-1 (ET-1) is primarily produced by vascular endothelial cells and plays multiple roles in the wound-healing response and organ fibrogenesis. In this study, we investigated the pathophysiological significance of ET-1 and involvement of RhoA, a member of the Rho GTPases, in hypertrophic scar/keloid formation. We found that ET-1 expression on dermal microvascular endothelial cells (ECs) in hypertrophic scars and keloids was higher than that in normal skin and mature scars. We also confirmed that ET-1 induced myofibroblast differentiation and collagen synthesis in cultured human dermal fibroblasts through the RhoA/Rho-kinase pathway. Finally, since hypertrophic scar/keloid formation was most prominent in areas exposed to mechanical stretch, we examined how mechanical stretch affected ET-1 secretion in human dermal microvascular ECs, and found that mechanical stretch increased ET-1 gene expression and secretion from ECs. Taken together, these results suggest that dermal microvascular ECs release ET-1 in response to mechanical stretch, and thereby contribute to the formation of hypertrophic scars and keloids through the RhoA/Rho-kinase pathway.

The dawn of computer-assisted robotic osteotomy with ytterbium-doped fiber laser.

Currently, laser radiation is used routinely in medical applications. For infrared lasers, bone ablation and the healing process have been reported, but no laser systems are established and applied in clinical bone surgery. Furthermore, industrial laser applications utilize computer and robot assistance; medical laser radiations are still mostly conducted manually nowadays. The purpose of this study was to compare the histological appearance of bone ablation and healing response in rabbit radial bone osteotomy created by surgical saw and ytterbium-doped fiber laser controlled by a computer with use of nitrogen surface cooling spray. An Ytterbium (Yb)-doped fiber laser at a wavelength of 1,070 nm was guided by a computer-aided robotic system, with a spot size of 100 µm at a distance of approximately 80 mm from the surface. The output power of the laser was 60 W at the scanning speed of 20 mm/s scan using continuous wave system with nitrogen spray level 0.5 MPa (energy density, 3.8 × 10(4) W/cm(2)). Rabbits radial bone osteotomy was performed by an Yb-doped fiber laser and a surgical saw. Additionally, histological analyses of the osteotomy site were performed on day 0 and day 21. Yb-doped fiber laser osteotomy revealed a remarkable cutting efficiency. There were little signs of tissue damage to the muscle. Lased specimens have shown no delayed healing compared with the saw osteotomies. Computer-assisted robotic osteotomy with Yb-doped fiber laser was able to perform. In rabbit model, laser-induced osteotomy defects, compared to those by surgical saw, exhibited no delayed healing response.

Infrared venography of the hand in Apert syndrome.

As well as craniofacial synostosis, complex syndactyly of hands is a distinctive feature of Apert syndrome. Consideration of blood flow to the digits is very important in separation surgery. Several reports offer information about arterial distribution in Apert's hands. Though, venous pattern has not been well discussed. Infrared venography offers a real-time image with minimal invasion. An Apert syndrome patient underwent a series of finger splitting surgeries. Infrared venography was carried out to assess veins. There was a palmar venous arch, placing distally to the metacarpophalangeal joint. The arch had to be cut to divide fused fingers sufficiently. As well as arterial abnormality, venous uniqueness should be noted in Apert syndactyly surgeries. Infrared venography, which can be carried out easily, offers good information that surgeon require.

Extraskeletal Myxoid Chondrosarcoma of the Vulva: A Case Report.

Extraskeletal myxoid chondrosarcoma (EMC) of the vulva is extremely rare. We report our experience with a case of disease control by radiation therapy to a localized lesion of EMC. A 41-year-old woman presented to our clinic with a vulvar mass. Magnetic resonance imaging showed a 15 cm mass between the perineum and the medial thigh muscle. It was the "adductor magnus muscle." After the needle biopsy, a histopathological diagnosis of EMC was made. Tissue genomic analysis detected the EWSR1-NR4A3 fusion gene. A joint operation by the Department of Orthopedics, Gynecology, and Plastic Surgery was performed, which included a wide excision of the perineum, partial excision of the medial thigh muscle, and rectus abdominis valvuloplasty. Intraoperatively, pubic infiltration was detected. Postoperative pelvic radiotherapy was administered as adjuvant therapy. Recurrent common iliac lymph node metastases outside the irradiation field and multiple lung metastases were observed. Pazopanib was administered as adjuvant therapy. Pulmonary metastases were controlled, but the pelvic tumor had spread, so the patient underwent radiation therapy. After second-line chemotherapy with doxorubicin, left pleural effusion and mediastinal lymph node metastasis appeared, and third-line chemotherapy with eribulin mesylate was administered. The pleural effusion improved, but the patient developed cough again, and trabectedin was administered as the fourth chemotherapy. In this case, there was no local recurrence for three years after radiotherapy, suggesting the effectiveness of radiotherapy in local control.

Three-Dimensional Craniofacial Landmark Detection in Series of CT Slices Using Multi-Phased Regression Networks.

Geometrical assessments of human skulls have been conducted based on anatomical landmarks. If developed, the automatic detection of these landmarks will yield both medical and anthropological benefits. In this study, an automated system with multi-phased deep learning networks was developed to predict the three-dimensional coordinate values of craniofacial landmarks. Computed tomography images of the craniofacial area were obtained from a publicly available database. They were digitally reconstructed into three-dimensional objects. Sixteen anatomical landmarks were plotted on each of the objects, and their coordinate values were recorded. Three-phased regression deep learning networks were trained using ninety training datasets. For the evaluation, 30 testing datasets were employed. The 3D error for the first phase, which tested 30 data, was 11.60 px on average (1 px = 500/512 mm). For the second phase, it was significantly improved to 4.66 px. For the third phase, it was further significantly reduced to 2.88. This was comparable to the gaps between the landmarks, as plotted by two experienced practitioners. Our proposed method of multi-phased prediction, which conducts coarse detection first and narrows down the detection area, may be a possible solution to prediction problems, taking into account the physical limitations of memory and computation.

Stretching Promotes Wound Contraction Through Enhanced Expression of Endothelin Receptor B and TRPC3 in Fibroblasts.

One factor that can contribute to the development of hypertrophic scar contracture is mechanical stress. Mechanical cyclic stretch stimuli enhance the secretion of endothelin-1 (ET-1) from keratinocyte. Cyclical stretching of fibroblasts also increases the expression level of the transient receptor potential ion channel (TRPC3), which is known to couple with the endothelin receptor and induce intracellular Ca2+ signaling via the calcineurin/nuclear factor of activated T cells (NFAT) pathway. The aim of this study was to investigate the relationship between keratinocytes and fibroblasts when they are stretched. Methods: The conditioned medium from stretched keratinocyte was added to the fibroblast populated collagen lattice. Then, we analyzed the levels of endothelin receptor in the human hypertrophic scar tissue and stretched fibroblasts. To address the function of TRPC3, we have used an overexpression system with the collagen lattice. Finally, the TRPC3 overexpressing fibroblasts were transplanted to mouse dorsal skin, and the rate of skin wound contraction was assessed. Results: Conditioned medium from stretched keratinocytes increased the rate of contraction of fibroblast populated collagen lattice. In human hypertrophic scar and stretched fibroblasts, endothelin receptor type B was increased. Cyclic stretching of TRPC3 overexpressing fibroblasts activated NFATc4, and stretched human fibroblasts showed more activation of NFATc4 in response to ET-1. The wound treated with TRPC3 overexpressing fibroblasts showed more contraction than control wound. Conclusion: These findings suggest that cyclical stretching of wounds have an effect on both keratinocytes and fibroblasts, where keratinocytes secret more ET-1, and fibroblasts develop more sensitivity to ET-1 by expressing more endothelin receptors and TRPC3.

Surgical Correction of Nipple Hypertrophy after Nipple-sparing Mastectomy with Breast Reconstruction.

Nipple hypertrophy is a relatively common phenomenon, particularly in the Asian patient population. The incidence and prevalence or cause of nipple hypertrophy are not well defined in the literature. As survival rates for breast cancer patients continue to improve, there is an increasing emphasis on enhancing their quality of life. Treatment options, such as lumpectomy and radiation therapy or mastectomy, now prioritize preservation of the nipple-areolar complex (NAC) through techniques like nipple-sparing mastectomy (NSM). This approach has been shown to improve patient satisfaction and quality of life. However, it is important to note that NSM is associated with certain complications, including NAC necrosis, malposition, and local recurrence of the tumor. Among those complications, nipple hypertrophy is quite rare. In this report, we present a case of nipple hypertrophy that developed after breast reconstruction, using autologous tissue. The patient, a 48-year-old woman, underwent NSM for breast cancer, and had a tissue expander placed simultaneously. Following tissue expansion, breast reconstruction with a deep inferior epigastric perforator (DIEP) flap was performed. However, during the tissue expansion phase, the patient's nipple gradually enlarged, and the protrusion became more pronounced after the DIEP flap transfer. Nipple reduction surgery was subsequently performed for both diagnostic and cosmetic purposes. We present this case along with a review of relevant literature.

Fetal mouse skin heals scarlessly in a chick chorioallantoic membrane model system.

In mammals, the early-gestation fetus has the regenerative ability to heal skin wounds without scar formation. This observation was first reported more than 3 decades ago, and has been confirmed in a number of in vivo animal models. Although an intensive research effort has focused on unraveling the mechanisms underlying scarless fetal wound repair, no suitable model of in vitro fetal skin healing has been developed. In this article, we report a novel model for the study of fetal wound healing. Fetal skin from gestational day 16.5 Balb/c mice (total gestation, 20 days) was grafted onto the chorioallantoic membrane of 12-day-old chicken embryos and cultured for up to 7 days. At 48 hours postengraftment, circular wounds (diameter = 1 mm) were made in the fetal skin using a rotating titanium sapphire laser (N = 45). The tissue was examined daily by visual inspection to look for signs of infection and ischemia. The grafts and the surrounding host tissue were examined histologically. In all fetal skin grafts, the wounds completely reepithelialized by postinjury day 7, with regeneration of the dermis. Fetal mouse skin xenografts transplanted onto the chorioallantoic membrane of fertilized chicken eggs provides a useful model for the study of fetal wound healing. This model can be used as an adjunct to traditional in vivo mammalian models of fetal repair.

"Bibloc advancement" with a combination of internal and external distracters.

Frontofacial monobloc advancement is one of the most rewarding techniques for correcting aesthetic and functional problems of patients with severe craniofacial synostosis, which can advance the upper and middle third of the face simultaneously. Application of gradual distraction technique has been reported to reduce notorious risks after a frontofacial monobloc advancement. The so-called "bibloc advancement" is a derivative of the frontofacial monobloc advancement. "Facial bloc" is horizontally divided into 2 different components: fronto-orbital component and maxillozygomatic component. From a different angle, it can be described as a combination of fronto-orbital advancement and Le Fort III advancement. Two pairs of distracters (1 internal for the supraorbital area and 1 external for the maxillozygomatic area with a pair of cross-facial pinning) were applied after the so-called bibloc osteotomy. Advancement of the upper and middle third of the face was done individually. This technique can be a good option for treating infants with severe syndromic craniofacial synostosis.

Cutaneous fistula on the cheek associated with oculo-auriculo-vertebral spectrum.

A Japanese boy, presented with epibulbar dermoid and ipsilateral preauricular appendages, had a pit on his cheek of the same side. An atrial septal defect and vertebral fusions were also identified. He was diagnosed with a mild type of oculo-auriculo-vertebral spectrum (OAVS). At the age of 18 months, his cheek was swollen with a slight fever. An infected cyst and cutaneous fistula enveloped by the risorius muscle were extracted. It was assumed to be a remnant of the fissure between the maxillary and mandibular prominences. This was the first case of cutaneous fistula confirmed histologically with OAVS, although there seem to be more cases. The possibility of the mechanism of smiling cheek dimple is also discussed.

A traumatic ulnar artery aneurysm in an infant.

Ulnar artery aneurysm is very rare in infancy. Only a few reports have been done. We report an 8-month-old baby with true ulnar artery aneurysm on her hypothenar eminence. She had no specific past medical history, but an episode of falling. We resected the pulsating mass compressing the ulnar nerve, utilizing a surgical microscope. Reconstruction of the vascular deficit was not performed. She presented no functional deficit of the hand and no evidence of growth disturbance so far. As hypothenar eminence is a susceptible part for repetitive strikes, and as vein is fragile to the pressure, bypassing arterial route with vein graft is not recommended unless there is no other option.

An occult case of the first branchial cleft anomaly.

We report a case of the first branchial cleft anomaly, clinically typical but occult in images and pathology. An 8-year-old female who had an induration below her right mandibular angle was referred to our department with a diagnosis of an infectious epidermal cyst. CT and MRI had shown no evidence of fistula or cyst. At the initial operation, a string structure was observed, but pathologically no epithelial structure was observed. However, the infection at the same site repeated and the symptoms became more severe than before. Considering a high probability of the first branchial anomaly, partial parotidectomy was performed as radical surgery. A cord structure attached to subcutaneous tissue at the intertragal notch was found. Although no epithelial component in the pathology was detected, this string structure was clinically considered as the rudimentary form of the first branchial anomaly.

Periostin is induced by IL-4/IL-13 in dermal fibroblasts and promotes RhoA/ROCK pathway-mediated TGF-ß1 secretion in abnormal scar formation.

Excess scar formation can occur after skin injurふy and lead to abnormal scar formation, such as keloids and hypertrophic scars, which are characterised by substantial deposition of extracellular matrix in the dermis. Periostin, an extracellular matrix protein that plays a crucial role in skin development and maintaining homeostasis, is also involved in skin disorders such as systemic/limited scleroderma, wound closure, and abnormal scar formation. However, the mechanism of periostin involvement in abnormal scar formation is not yet fully understood. In this study, we investigated the mechanism by which periostin is involved in abnormal scar formation. Treatment of human dermal fibroblasts (HDFs) with IL-4 and IL-13, which are cytokines of Th2 type immune responses that are up-regulated in abnormal scars, dramatically elevated the levels of periostin mRNA and protein, and also promoted the secretion of periostin by HDFs. Transforming growth factor-ß1 (TGF-ß1) had the same effect on HDFs as IL-4 and IL-13. Stimulation of HDFs with periostin promoted RhoA/ROCK pathway-mediated TGF-ß1 secretion from HDFs. Our results suggest that IL-4 and IL-13 induce periostin expression and secretion, and in turn, secreted periostin induces RhoA/ROCK pathway-mediated TGF-ß1 secretion. Secreted TGF-ß1 then induces further periostin production and secretion, thereby promoting abnormal scar formation.

Effects of adiponectin on growth and differentiation of human keratinocytes--implication of impaired wound healing in diabetes.

Impaired wound healing is one of the most common complications associated with diabetes. Adiponectin is an abundant circulating adipocyte-derived cytokine that has beneficial effects on disorders accompanying diabetes. Herein we report that adiponectin has a regulatory effect on the growth and differentiation of HaCaT human keratinocyte cells. Furthermore, adiponectin regulated the expression of TGFbeta isoforms in keratinocytes in a dose-dependent manner, which implies that adiponectin modulates other types of cells related to wound repair via secretion of growth factors from keratinocytes. Moreover, TUNEL assay results revealed that adiponectin enhances apoptosis of keratinocytes. Taken together, the present results indicate that adiponectin has suppressive effects on the formation of hyperkeratosis commonly seen in patients with diabetic foot and its application may be beneficial for developing treatment for that disorder.

Lateral orbital expansion and gradual fronto-orbital advancement: an option to treat severe syndromic craniosynostosis.

In some patients with severe syndromic craniosynostosis, bony orbits are so small and shallow that the eyeballs dislocate. Dry cornitis and conjunctivitis can be seen often. When conventional fronto-orbital advancement is attempted in these cases, side walls of the orbit cannot go forward, because the width of bony orbit is smaller than the eyeball. To expand bony orbits and cranial volume, supralateral rim of the orbit was expanded laterally at the time of operation and gradually advanced foward postoperatively. With a coronal skin incision approach, frontal bone was taken off. Supralateral orbital rim bone was detached and cut at the centers of the orbits. Lateral expansion, 5 to 10 mm, was made and fixed with polylactate plates. A pair of distraction devices was fixed between the orbital rim and the temporal bone. Frontal bone was let floating on the dura mater and tied loosely with the orbital rim. Advancement of 1 to 1.5 mm/d was carried out, and the devices were taken off after 1-month consolidation period. Five patients with Pfeiffer syndrome, 1 with Crouzon, and 1 with Beare-Stevenson cutis gyrata syndrome were treated with this method. Procedure, outcomes, and complications are discussed.

ß-Catenin-Dependent Wnt Signaling: A Pathway in Acute Cutaneous Wounding.

BACKGROUND: Acute wound healing is a dynamic process that results in the formation of scar tissue. The mechanisms of this process are not well understood; numerous signaling pathways are thought to play a major role. Here, the authors have identified ß-catenin-dependent Wnt signaling as an early acute-phase reactant in acute wound healing and scar formation. METHODS: The authors created 6-mm full-thickness excisional cutaneous wounds on adult ß-catenin-dependent Wnt signal (BAT-gal) reporter mice. The expression of canonical Wnt after wounding was analyzed using X-gal staining and quantitative real-time polymerase chain reaction. Next, recombinant mouse Wnt3a (rmWnt3a) was injected subcutaneously to the wound edge, daily. The mice were killed at stratified time points, up to 15 days after injury. Histologic analysis, quantitative real-time polymerase chain reaction, and Western blot were performed. RESULTS: Numerous individual Wnt ligands increased in expression after wounding, including Wnt3a, Wnt4, Wnt10a, and Wnt11. A specific pattern of Wnt activity was observed, localized to the hair follicle and epidermis. Mice injected with rmWnt3a exhibited faster wound closure, increased scar size, and greater expression of fibroblast growth factor receptor-2 and type I collagen. CONCLUSIONS: The authors' data suggest that ß-catenin-dependent Wnt signaling expression increases shortly after cutaneous wounding, and exogenous rmWnt3a accelerates reepithelialization, wound matrix maturation, and scar formation. Future experiments will focus on the intersection of Wnt signaling and other known profibrotic cytokines.

Foxo1 represses expression of musclin, a skeletal muscle-derived secretory factor.

Musclin is a novel skeletal muscle-derived secretory factor, whose mRNA level is markedly regulated by nutritional status. In the present study, we investigated the mechanism of musclin mRNA regulation by insulin. In C2C12 myocytes, insulin-induced upregulation of musclin mRNA was significantly decreased by treatment of phosphatidylinositol 3-kinase (PI3K) inhibitor, LY294002, and was abolished in C2C12 myocytes stably expressing a constitutively active Foxo1 (Foxo1-3A), suggesting the involvement of Foxo1 in the regulation of musclin mRNA. Promoter deletion analysis of musclin promoter revealed that the region of -303/-123 is important for the repression of promoter activity by Foxo1. Chromatin immunoprecipitation assay showed that Foxo1 bound to musclin promoter. Musclin mRNA level was markedly downregulated in gastrocnemius muscle of Foxo1 transgenic mice. Our results demonstrated that Foxo1 downregulates musclin mRNA expression both in vitro and in vivo, which should explain insulin-mediated upregulation of this gene in muscle cells.