I read with great interest the recent article published in this Journal by Skaria regarding the utility of island-pedicle flaps (IPF) for the aesthetic single stage reconstruction of surgical defects of the medial canthus(1) . The author very eruditely discusses the design, execution and excellent cosmetic results that may be ...

OBJECTIVES/HYPOTHESIS: To describe our experience with surgical reconstruction of whole subunit nasal alar skin losses following Mohs ablative surgery, using a subcutaneous melolabial island flap with emphasis on a simplified technique to minimize facial scarring and optimize facial contour. STUDY DESIGN: Retrospective review of case series. METHODS: A single surgeon's ...

There is limited data regarding the epidemiology, pathology, and management of distal radius fractures from centers in Asia. The advanced economies in Asia include Hong Kong, Japan, Korea, Singapore, and Taiwan, whereas the prominent emerging economies are China, India, Malaysia, Philippines, and Thailand. This article examines the available epidemiological data ...

: There is an ongoing debate about the reliability of various lower abdominal flaps for breast reconstruction. The authors evaluate in vivo perfusion of these flaps to objectively determine which techniques and which skin island zones had better perfusion. : A prospective study was performed on 77 single-pedicle breast reconstructions ...

Summary Background  Medium- to large-sized surgical defects of the forehead and frontal scalp provide a challenge for the reconstructive surgeon. Objectives  To highlight the utility of a frontalis-based island pedicle flap (FIPF) for the single-stage, aesthetic reconstruction of such defects. Methods  The design and detailed surgical technique required for a ...

Background:  The medial canthus is a frequent site for skin cancer and reconstruction after Mohs surgery can prove to be challenging. In literature a variety of reconstruction methods are recommended for these cases. Flap reconstructions are mostly transposition flaps from the glabella, a skin with different properties than the canthal ...

: Perforator flaps are increasingly used in reconstructive surgery. However, the microvascular perfusion pattern within these flaps remains essentially unknown. In perforator flaps, the importance of preserving the skin bridge at the base is still an object of debate. The authors hypothesized that dividing the skin bridge will increase peripheral ...

BACKGROUND: The medial sural perforator island flap may be suitable for the reconstruction of postburn knee flexion contractures. However, postburn knee flexion contractures are usually associated with burns of the calf, which is the donor site of the medial sural perforator flap. Thus, there are concerns regarding the safety of ...

SUMMARY:: Oropharyngeal reconstruction following head and neck oncologic resection has utilized local, regional, and free tissue transfer flap options. The modality utilized is often guided by the type of defect created as well as the surgeon's preference. In this article, the authors introduce the application of the supraclavicular artery island ...

Traditional techniques used for harvesting the pectoralis major myocutaneous (PMMC) flap have accompanying disadvantages, such as the necessity for an upper chest skin incision, the bulkiness of myocutaneous tissue at the pedicle of the flap, and the risk of total or partial necrosis of flap tissue. The aim of this ...

INTRODUCTION: Free flaps with vascular anastomosis have been widely used in clinical practice for more than 30 years. They are standard in reconstructive surgery following extensive resections caused by neoplasms of the head and neck. The anterolateral thigh flap (ALT) constitutes very good reconstructive material due to the long vascular ...

Flying animals exhibit remarkable degrees of both stability and manoeuvrability. Our understanding of these capabilities has recently been improved by the identification of a source of passive damping specific to flapping flight. Examining how this damping effect scales among different species and how it affects active manoeuvres as well as ...

We perform atomistic simulations on the fracture behavior of two typical metallic glasses, one brittle (FeP) and the other ductile (CuZr), and show that brittle fracture in the FeP glass is governed by an intrinsic cavitation mechanism near crack tips in contrast to extensive shear banding in the ductile CuZr ...

We study the average velocity of crack fronts during stable interfacial fracture experiments in a heterogeneous quasibrittle material under constant loading rates and during long relaxation tests. The transparency of the material (polymethylmethacrylate) allows continuous tracking of the front position and relation of its evolution to the energy release rate. ...

Bone comprises a complex structure of primarily collagen, hydroxyapatite and water, where each hierarchical structural level contributes to its strength, ductility and toughness. These properties, however, are degraded by irradiation, arising from medical therapy or bone-allograft sterilization. We provide here a mechanistic framework for how irradiation affects the nature and ...

The structure of human cortical bone evolves over multiple length scales from its basic constituents of collagen and hydroxyapatite at the nanoscale to osteonal structures at near-millimeter dimensions, which all provide the basis for its mechanical properties. To resist fracture, bone's toughness is derived intrinsically through plasticity (e.g., fibrillar sliding) ...

The in situ molecular scale response of end-grafted polystyrene to shear against a deuterated polystyrene melt was investigated with neutron reflectometry. The derived grafted polystyrene density profiles showed that the grafted polystyrene was retained on the quartz wafer during the measurements. The profiles suggested that the end-grafted polystyrene response to ...

We present results of a hybrid experimental and theoretical investigation of the fracture scaling in scratch tests and show that scratching is a fracture dominated process. Validated for paraffin wax, cement paste, Jurassic limestone and steel, we derive a model that provides a quantitative means to relate quantities measured in ...

OBJECTIVE.: The aim of this study was to retrospectively review the orbital fractures treated at our institution, especially epidemiologic aspects, treatment options, and postoperative sequelae. STUDY DESIGN.: Three hundred fourteen patients with orbital fractures treated at the Department of Oral and Maxillofacial Surgery of the Central University Hospital in Asturias ...

Since the hematopoetic system is located within the bone marrow, it is not surprising that recent evidence has demonstrated the existence of molecular interactions between bone and immune cells. While interleukin 1 (IL-1) and IL-18, two cytokines of the IL-1 family, have been shown to regulate differentiation and activity of ...

Glucocorticoids (GCs) inhibit the resorptive capacity of the osteoclast by disrupting its cytoskeleton. We find that calpain-6 (Capn6), a unique, nonproteolytic member of its family, is suppressed 12-fold by dexamethasone (DEX) in the bone-degrading cell. While Capn6 abundance parallels commitment of naive bone marrow macrophages (BMMs) to the osteoclast phenotype, ...

Mutations in Bruton's tyrosine kinase (Btk) cause the B-cell disorder X-linked agammaglobulinaemia (XLA) in humans, but the effect of Btk deficiency in human bone health has not been investigated previously. In this study, we show that human Btk-deficient osteoclasts are defective at resorption activity in vitro owing to a dysregulation ...

Objective: To investigate the epidemiology of player-player contact injuries in a nationally representative sample of US high school student-athletes. Methods: Data from the National High School Sports-Related Injury Surveillance Study were analyzed to calculate rates, describe patterns, and evaluate potential risk factors for player-player contact injuries. Results: Player-player contact injuries ...

Bone sialoprotein (BSP) and osteopontin (OPN) belong to the small integrin-binding ligand N-linked glycoprotein (SIBLING) family, whose members interact with bone cells and bone mineral. Previously, we showed that BSP knockout (BSP(-/-) ) mice have a higher bone mass than wild type (BSP(+/+) ) littermates, with very low bone-formation activity ...

Being a connective tissue, bone can increase or decrease its mass through the process of remodeling. Using a discovery in the mid-1980s-that tumor necrosis factor (TNF) could dramatically increase formation of osteoclasts (the cells that break down bone)-researchers at Amgen (Thousand Oaks, CA) discovered a TNF-like molecule that regulated bone ...

The role of the small Rho GTPase Rac2 in mature osteoclasts has not been extensively studied. Rac2(-/-) mice are of normal size and have normal tooth eruption. However, femoral cortical thickness was significantly greater in Rac2(-/-) compared to wild-type mice, while percent cortical porosity was lower. As assessed by histomorphometry, ...

The mechanisms by which Pi-homeostasis controls bone biology are poorly understood. Here we used Dmp1-null mice, a hypophosphatemic rickets/osteomalacia model, combined with a metatarsal organ culture, and an application of neutralizing FGF23 antibodies to gain insight into the roles of Pi in bone biology. We showed that 1) abnormal bone ...

Osteolytic lesions with activated osteoclast (OC) and suppressed osteoblast (OB) activity are characteristics of myeloma bone lesion. Recently, it has been shown that bortezomib treatment enhances OB function. To evaluate the effect of bortezomib on myeloma bone lesions, we performed bone scans, where increased uptake of the radiopharmaceutical by OBs ...

There is emerging interest for osteoclasts as key players in the erosive and inflammatory events leading to joint destruction in chronic arthritis. In fact, chronic inflammatory joint diseases such as psoriatic arthritis and rheumatoid arthritis are often characterized by destruction of juxta-articular bone and erosions due to the elevated activity ...

Hypercalcemia is a significant complication of certain human malignancies that is primarily caused by the release of calcium from bone due to marked bone resorption by osteoclast activation. Osteoclast differentiation and activation is mediated by receptor activator of NF-κB ligand (RANKL). Transgenic mice overexpressing murine soluble RANKL (sRANKL) that we ...

The anabolic effects of parathyroid hormone (PTH) on bone formation are impaired by concurrent use of antiresorptive drugs. We found that the release of active transforming growth factor (TGF)-β1 during osteoclastic bone resorption is inhibited by alendronate. We showed that mouse Sca-1-positive (Sca-1(+)) bone marrow stromal cells are a skeletal ...

Osteoporosis, which results from excessive bone resorption by osteoclasts, is the major cause of morbidity for elder people. Identification of clinically relevant regulators is needed to develop novel therapeutic strategies. Rho GTPases have essential functions in osteoclasts by regulating actin dynamics. This is of particular importance since actin cytoskeleton is ...

This review summarizes recently published data on the epidemiology, pathophysiology and treatment of cystic fibrosis (CF)-related low bone mineral density (BMD). A systematic literature review reports that the pooled prevalence of osteoporosis in adults with CF is 23.5% [95% confidence interval (CI) 16.6-31.0] and the pooled prevalences of radiologically confirmed ...

Bone regeneration is required for fracture healing. Various procedures have been used to promote osteogenesis with bone morphogenetic proteins (BMPs). We assessed the effects of BMP-2, BMP-5, and BMP-6 in isolated and combined use on the generation of osteoblasts and osteoclasts by comparing the osteoclastic potency of each on osteoclasts ...

Bone homeostasis is controlled by the balance between osteoblastic bone formation and osteoclastic bone resorption. Excessive bone resorption is involved in the pathogenesis of bone-related disorders such as osteoporosis, arthritis and periodontitis. To obtain new antiresorptive agents, we searched for natural compounds that can inhibit osteoclast differentiation and function. We ...

Modern medical practices allow patients to survive acute insults and be sustained by machinery and medicines for extended periods of time. We define chronic critical illness as a later stage of prolonged critical illness that requires tracheotomy. These patients have persistent elevations of inflammatory cytokines, diminished hypothalamic-pituitary function, hypercatabolism, immobilization, ...

Carboxymethylcellulose (CMC) and hydroxypropylmethylcellulose (HPMC) serve as carriers for growth factors and bone substitutes. Although both carriers are placed into the defect sites, their impacts on bone regeneration are unclear. Herein, we examined whether CMC and HPMC affect the differentiation of bone marrow progenitors into osteoclasts and osteoblasts. We therefore ...

Sustained parathyroid hormone (PTH) elevation stimulates bone remodeling (ie, both resorption and formation). The former results from increased RANKL synthesis, but the cause of the latter has not been established. Current hypotheses include release of osteoblastogenic factors from osteoclasts or from the bone matrix during resorption, modulation of the production ...

Dysosteosclerosis (DSS), an extremely rare dense bone disease, features short stature and fractures and sometimes optic atrophy, cranial nerve palsy, developmental delay, and failure of tooth eruption in infancy or early childhood consistent with osteopetrosis (OPT). Bone histology during childhood shows unresorbed primary spongiosa from deficient osteoclast action. Additionally, there ...

Bone homeostasis is maintained through the balanced action of bone-forming osteoblasts and bone-resorbing osteoclasts. Under pathological conditions or with age, excessive bone loss is often observed due to increased bone resorption. Since osteoclasts are the primary cells in the body that can resorb bone, molecular understanding of osteoclast fate has ...

Metabolic bone diseases, such as rheumatoid arthritis (RA) and osteoporosis, affect hundreds and millions of people worldwide leading causes of long-term pain and disability. Effective clinical treatment for bone destruction in bone diseases is lacking because the knowledge about molecular mechanisms leading to bone destruction are incompletely understood. Recently, it ...

Otosclerosis is a complex bone dystrophy of the human otic capsule leading to conductive and sensorineural hearing loss. Since otosclerosis may, at least in part, be considered as an autoimmune-inflammatory disease, disturbed balance of TNF-alpha and osteoprotegerin (OPG) expression has been implicated in the pathological bone remodeling. It has been ...

Interleukin-17A (IL-17A) is a pro-inflammatory cytokine secreted by a subset of memory T cells and other innate immune cells. It is associated with rheumatoid arthritis (RA) due to IL-17A expression in RA synovial fluid. The severe bone erosive rat adjuvant-induced arthritis (rAIA) and mouse collagen-induced arthritis (mCIA) models were used ...

Resorbable calcium phosphate (CaP) biomaterials have demonstrated considerable efficacy in bone reconstructive surgery. Furthermore, bisphosphonates (BPs) are well known anti-resorptive agents largely used in clinical treatments for osteoporosis. An injectable BP-combined CaP matrix has been developed in order to biologically reinforce osteoporotic bone by increasing the bone fraction and improving ...

Cyclooxygenase-2 (COX-2) inhibitors suppress bone repair and bone formation by suppressing angiogenesis as well as potentially interfering with osteoblast and osteoclast functions. In spite of these reports, there is a controversy over the exact effects of COX-2 inhibitors on bone formation processes itself. This work was designed to investigate the ...

Osteoclasts are known to exert their resorptive activity through a so-called resorption cycle consisting of alternating resorption and migration episodes and resulting typically in the formation of increasing numbers of discrete round excavations on bone slices. This study shows that glucocorticoids deeply modify this resorptive behavior. First, glucocorticoids gradually induce ...

Bone mass is determined by a continuous remodeling process, whereby the mineralized matrix is being removed by osteoclasts and subsequently replaced with newly formed bone tissue produced by osteoblasts. Here we report the presence of endogenous amides of long-chain fatty acids with amino acids or with ethanolamine (N-acyl amides) in ...

Osteoclasts, the multinucleated bone-resorbing cells, arise through fusion of precursors from the myeloid lineage. However, not all osteoclasts are alike; osteoclasts at different bone sites appear to differ in numerous respects. We investigated whether bone marrow cells obtained from jaw and long bone differed in their osteoclastogenic potential. Bone marrow ...

Aneurysmal bone cyst (ABC) is a pediatric osseous tumor characterized by extensive destruction of the surrounding bone. The molecular mechanisms underlying its pathogenesis are completely unknown. Recent work showed that translocation of the TRE17/USP6 locus occurs in over 60% of ABC cases resulting in TRE17 overexpression. Immature osteoblasts are presumed ...

The nuclear receptor peroxisome proliferator-activated receptor (PPAR)γ is a crucial cellular and metabolic switch that regulates many physiologic and disease processes. Emerging evidence reveals that PPARγ is also a key modulator of skeletal remodeling. Long-term use of rosiglitazone, a synthetic PPARγ agonist and a drug to treat insulin resistance, increases ...