Identification of a recurrent mosaic KRAS variant in brain tissue from an individual with nevus sebaceous syndrome.

Nevus sebaceous syndrome (NSS) is a rare, multisystem neurocutaneous disorder, characterized by a congenital nevus, and may include brain malformations such as hemimegalencephaly or focal cortical dysplasia, ocular, and skeletal features. It has been associated with several eponyms including Schimmelpenning and Jadassohn. The isolated skin lesion, nevus sebaceous, is associated with postzygotic variants in HRAS or KRAS in all individuals studied. The RAS proteins encode a family of GTPases that form part of the RAS/MAPK signaling pathway, which is critical for cell cycle regulation and differentiation during development. We studied an individual with nevus sebaceous syndrome with an extensive nevus sebaceous, epilepsy, intellectual disability, and hippocampal sclerosis without pathological evidence of a brain malformation. We used high-depth gene panel sequencing and droplet digital polymerase chain reaction (PCR) to detect and quantify RAS/MAPK gene variants in nevus sebaceous and temporal lobe tissue collected during plastic and epilepsy surgery, respectively. A mosaic KRAS c.34G > T; p.(Gly12Cys) variant, also known as G12C, was detected in nevus sebaceous tissue at 25% variant allele fraction (VAF), at the residue most commonly substituted in KRAS Targeted droplet digital PCR validated the variant and quantified the mosaicism in other tissues. The variant was detected at 33% in temporal lobe tissue but was absent from blood and healthy skin. We provide molecular confirmation of the clinical diagnosis of NSS. Our data extends the histopathological spectrum of KRAS G12C mosaicism beyond nevus sebaceous to involve brain tissue and, more specifically, hippocampal sclerosis.

Surgical Management of Intramuscular Venous Malformations.

BACKGROUND: Intramuscular venous malformations, often erroneously called "intramuscular hemangiomas," present to pediatric orthopaedic surgeons either as a differential diagnosis of tumor or as a cause of muscle pain. Treatment options include injection sclerotherapy or surgery. There is some literature to indicate that sclerotherapy can reduce pain, but little evidence on the effectiveness of surgery. The primary aim of this study was to evaluate the efficacy of surgical resection for intramuscular venous malformations, with a secondary aim to evaluate the natural history and presentation of intramuscular venous malformations to improve clinician understanding of this condition. METHODS: A retrospective chart analysis was performed of cases identified from a vascular anomalies database from January 2004 and December 2018. Primary outcome was change in preoperative and postoperative pain. Natural history of the lesion was assessed, including age when the lesion was first noticed, when it became painful, and when it required treatment. RESULTS: Fifty-four cases were identified in the study period of which 40 underwent surgery. Pain improved in 36 of 39 patients (92.3%) who had pain before surgery and 29 (74.4%) were pain free after surgery. All 13 patients who required whole muscle excision to resect the lesion experienced an improvement in pain and 10 (76.9%) were pain free. A history of previous intervention, with surgery or sclerotherapy showed a trend towards less successful surgical outcomes. Patients presented across a wide age range from infancy to adulthood, but the most common presentation was pain with exercise between 9 and 16 years of age, with presence of a mass in about half of cases. CONCLUSIONS: Surgery, when performed by a surgeon with appropriate experience, is an effective first-line treatment for painful intramuscular venous malformations, offering pain relief in the majority of cases. Magnetic resonance imaging and ultrasound are diagnostic in most cases. The majority of lesions are resectable, meaning they can be removed with a margin leaving a functional limb. Sometimes resection of a whole muscle is required. LEVEL OF EVIDENCE: Level IV-case series.

Pitfalls and Promise of 3-dimensional Image Comparison for Craniofacial Surgical Assessment.

Three-dimensional (3D) photography is becoming widely used in plastic surgery. It provides an accurate and reproducible record of the facial surface anatomy and could be a versatile tool for treatment planning and assessment. However, the existing software tools available for the assessment of 3D facial imaging often give highly misleading results. The goal of this special topic article is to give clinicians an insight into methods of 3D image assessment and explain the reasons why results may be misleading. We point toward the advantages of an alternative approach using "nonrigid surface registration" for the comparison of pre- and postsurgical images. This approach is compared with the regular rigid surface registration, and this is illustrated by the assessment of a child with Crouzon syndrome before and after LeFort III osteotomy and distraction. Findings of the standard method imply that changes have occurred that are anatomically not possible, whereas the alternative approach indicates realistic changes. Furthermore, we demonstrate an exciting capacity of 3D image analysis to construct reference populations of normal head size and shape. These can be used to assess the parts of the head that are normal and abnormal pre- and posttreatment of the same child. We conclude that, while 3D image analysis has great potential in surgical assessment, existing software does not always give an adequate assessment. Collaboration among surgeons and engineering and computer science specialists should be encouraged. This way, more comprehensive and accurate techniques in patient assessment and surgical planning can be developed and applied in clinical practice.

Prolonged antibiotic treatment for infected low flow vascular malformations.

BACKGROUND: Infection in low flow malformations is difficult to diagnose and treat. Initial presentation can be followed by cycles of recurrent infection lasting several years. The optimal duration of antibiotic therapy to prevent recurrence of infection has not been established. METHODS: All cases of infection in low flow malformations at the Royal Children's Hospital over a ten-year period were reviewed. Clinical markers of infection and duration of initial antibiotic treatment were correlated with the development of recurrent episodes of infection. RESULTS: Twenty-one patients met criteria for inclusion. Nineteen were diagnosed as lymphatic malformations and two as venous malformations. The majority of patients (13 or 62%) received a prolonged course of six weeks or more of antibiotics. Eleven (52%) patients went on to have recurrent infections, but these were significantly less likely to be in those treated with a long course of antibiotics (Fisher's exact test, p=0.026). In only 12 of 21 cases could a bacterium be grown. Elevated CRP was the most consistent abnormal laboratory finding in infection. CONCLUSIONS: Longer courses of antibiotics reduce the risk of recurrent infection in low-flow vascular malformations. We recommend an antibiotic course of three months or more at the initial presentation of infection in a low flow malformation. Elevated CRP is the most sensitive test for diagnosis of infection in low-flow malformations. TYPE OF STUDY: Treatment study. LEVEL OF EVIDENCE: III.

Wound management of ulcerated haemangioma of infancy - an audit.

Haemangioma of infancy, a benign tumour of blood vessels, is the most common tumour of infancy. Ulceration, the most common complication, presents a unique wound care challenge. A retrospective audit of medical records of children with haemangioma of infancy who presented to the Royal Children's Hospital, Melbourne, Australia, between January 2000 and December 2014 was undertaken with an aim to examine wound management of ulcerated haemangioma of infancy. In total, 535 hospital medical records were identified as suitable, of which 352 were randomly selected and audited, of which 84 patients had ulcerated haemangioma of infancy, and 62 were subject to wound management. Of these, 35 were successfully managed by wound dressings, 9 were not fully healed at the time of last review, and 18 were referred for surgical excision. Patients attended an average of five outpatient visits, and the average time from presentation to documented healing was 105 days. There were a total of 225 episodes of wound dressing, for which there was a documented follow-up appointment at which healing could be assessed. Although a wide range of dressings were used, there was no clear pattern of benefit of one dressing over another. Wounds were less likely to be healed after the use of a silver-impregnated dressing. Pain was poorly documented. Clinical assessment of whether wounds were infected was of no help in planning treatment. There is considerable variability in the management of this difficult wound group, and further prospective studies are required.

GAPTrap: A Simple Expression System for Pluripotent Stem Cells and Their Derivatives.

The ability to reliably express fluorescent reporters or other genes of interest is important for using human pluripotent stem cells (hPSCs) as a platform for investigating cell fates and gene function. We describe a simple expression system, designated GAPTrap (GT), in which reporter genes, including GFP, mCherry, mTagBFP2, luc2, Gluc, and lacZ are inserted into the GAPDH locus in hPSCs. Independent clones harboring variations of the GT vectors expressed remarkably consistent levels of the reporter gene. Differentiation experiments showed that reporter expression was reliably maintained in hematopoietic cells, cardiac mesoderm, definitive endoderm, and ventral midbrain dopaminergic neurons. Similarly, analysis of teratomas derived from GT-lacZ hPSCs showed that ß-galactosidase expression was maintained in a spectrum of cell types representing derivatives of the three germ layers. Thus, the GAPTrap vectors represent a robust and straightforward tagging system that enables indelible labeling of PSCs and their differentiated derivatives.

Isolation of human lymphatic endothelial cells by multi-parameter fluorescence-activated cell sorting.

Lymphatic system disorders such as primary lymphedema, lymphatic malformations and lymphatic tumors are rare conditions that cause significant morbidity but little is known about their biology. Isolating highly pure human lymphatic endothelial cells (LECs) from diseased and healthy tissue would facilitate studies of the lymphatic endothelium at genetic, molecular and cellular levels. It is anticipated that these investigations may reveal targets for new therapies that may change the clinical management of these conditions. A protocol describing the isolation of human foreskin LECs and lymphatic malformation lymphatic endothelial cells (LM LECs) is presented. To obtain a single cell suspension tissue was minced and enzymatically treated using dispase II and collagenase II. The resulting single cell suspension was then labelled with antibodies to cluster of differentiation (CD) markers CD34, CD31, Vascular Endothelial Growth Factor-3 (VEGFR-3) and PODOPLANIN. Stained viable cells were sorted on a fluorescently activated cell sorter (FACS) to separate the CD34(Low)CD31(Pos)VEGFR-3(Pos)PODOPLANIN(Pos) LM LEC population from other endothelial and non-endothelial cells. The sorted LM LECs were cultured and expanded on fibronectin-coated flasks for further experimental use.

Three patterns of fronto-orbital remodeling for metopic synostosis: comparison of cranial growth outcomes.

BACKGROUND: The authors compared cranial growth across three patterns of fronto-orbital remodeling for metopic synostosis. METHODS: The authors reviewed all patients who underwent fronto-orbital remodeling for isolated metopic synostosis between 2006 and 2009. Inclusion criteria consisted of patients with preoperative, short-term postoperative (4 to 12 months), and long-term postoperative (>36 months) three-dimensional photographs. Patients were categorized by fronto-orbital remodeling pattern: group 1, retrocoronal; group 2, partial coronal; and group 3, precoronal. Head circumference, minimum frontal breadth (ft-ft), and maximum cranial length were measured by three-dimensional photographs, converted to standard Z scores, and compared. RESULTS: Thirty-one patients met inclusion criteria (group 1, n=12; group 2, n=10; and group 3, n=9). Group 1 presented with the greatest phenotypic severity. From preoperative to short-term postoperative assessment, head circumference Z scores rose for group 1 but dropped for groups 2 and 3, and the three groups demonstrated equivalent increases in minimum frontal breadth Z scores. From short-term to long-term postoperatively, the three groups demonstrated similar stability in head circumference Z scores but decreased minimum frontal breadth Z scores. From preoperatively to long-term postoperatively, head circumference Z scores rose for group 1 but fell for groups 2 and 3 (change in Z score, 0.5, -0.5, and -0.7, respectively; p=0.06) and the three groups demonstrated equivalent drops in minimum frontal breadth Z scores. Across preoperative to short-term postoperative and preoperative to long-term postoperative assessment, group 1 displayed the least drop in maximum cranial length Z scores. CONCLUSIONS: Retrocoronal patterns of fronto-orbital remodeling provide long-term gains in head circumference percentile and the least growth impairment in cranial length. Irrespective of osteotomy design, expansion in frontal breadth relapses significantly over time. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, III.

The adipogenic potential of various extracellular matrices under the influence of an angiogenic growth factor combination in a mouse tissue engineering chamber.

The extracellular matrix (ECM) Matrigel™ has frequently and successfully been used to generate new adipose tissue experimentally, but is unsuitable for human application. This study sought to compare the adipogenic potential of a number of alternative, biologically derived or synthetic ECMs with potential for human application, with and without growth factors and a small fat autograft. Eight groups, with six severe combined immunodeficient (SCID) mice per group, were created with bilateral chambers (silicone tubes) implanted around the epigastric vascular pedicle, with one chamber/animal containing a 5mg fat autograft. Two animal groups were created for each of four ECMs (Matrigel™, Myogel, Cymetra® and PuraMatrix™) which filled the bilateral chambers. One group/ECM had no growth factors added to chambers whilst the other group had growth factors (GFs) (vascular endothelial growth factor-A (VEGF-A) plus fibroblast growth factor-2 (FGF-2) plus platelet-derived growth factor-BB (PDGF-BB)) added to both chambers. At 6weeks, chamber tissue was morphometrically assessed for percent and absolute adipose tissue volume. Overall, the triple GF regime significantly increased percent(∗) and absolute(#) adipose tissue volume (p<0.0005(∗#)) compared to chambers without triple GF treatment. The fat autograft also significantly increased percent (p<0.0005) and absolute (p<0.011) adipose tissue volume. Cymetra® (human collagen) constructs yielded the largest total tissue and absolute adipose tissue volume. We found that the pro-angiogenic FGF-2, VEGF-A and PDGF-BB combination in ECMs of synthetic and biological origin produced an overall significantly increased adipose tissue volume at 6weeks and may have clinical application, particularly with Cymetra.

Isolation of human lymphatic malformation endothelial cells, their in vitro characterization and in vivo survival in a mouse xenograft model.

Human lymphatic vascular malformations (LMs), also known as cystic hygromas or lymphangioma, consist of multiple lymphatic endothelial cell-lined lymph-containing cysts. No animal model of this disease exists. To develop a mouse xenograft model of human LM, CD34(Neg)CD31(Pos) LM lymphatic endothelial cells (LM-LEC) were isolated from surgical specimens and compared to foreskin CD34(Neg)CD31(Pos) lymphatic endothelial cells (LECs). Cells were implanted into a mouse tissue engineering model for 1, 2 and 4 weeks. In vitro LM-LECs showed increased proliferation and survival under starvation conditions (P < 0.0005 at 48 h, two-way ANOVA), increased migration (P < 0.001, two-way ANOVA) and formed fewer (P = 0.029, independent samples t test), shorter tubes (P = 0.029, independent samples t test) than foreskin LECs. In vivo LM-LECs implanted into a Matrigel™-containing mouse chamber model assembled to develop vessels with dilated cystic lumens lined with flat endothelium, morphology similar to that of clinical LMs. Human foreskin LECs failed to survive implantation. In LM-LEC implanted chambers the percent volume of podoplanin(Pos) vessels was 1.18 ± 2.24 % at 1 week, 6.34 ± 2.68 % at 2 weeks and increasing to 7.67 ± 3.60 % at 4 weeks. In conclusion, the significantly increased proliferation, migration, resistance to apoptosis and decreased tubulogenesis of LM-LECs observed in vitro is likely to account for their survival and assembly into stable LM-like structures when implanted into a mouse vascularised chamber model. This in vivo xenograft model will provide the basis of future studies of LM biology and testing of potential pharmacological interventions for patients with lymphatic malformations.

Total cranial vault remodeling for isolated sagittal synostosis: part I. Postoperative cranial suture patency.

BACKGROUND: Total vault reconstruction addresses all phenotypic aspects of scaphocephaly. The clinical implications of remodeling across open cranial sutures, however, remain unclear. The purpose of this study was to assess patency of unaffected sutures following total vault remodeling for isolated sagittal synostosis. METHODS: The authors reviewed routine postoperative computed tomographic scans of patients who underwent total vault remodeling for isolated sagittal synostosis between 2004 and 2008. Sutural patency was scored by a single reviewer as follows: 0 = closed, 1 = partial, and 2 = open. Individual suture scores were tallied for a total sutural patency score. Computed tomographic scans were stratified by postoperative time and craniofacial surgeon. RESULTS: Forty-two patients met the inclusion criteria. Individual sutural closure rates were 42.6, 38.3, 74.5, and 74.5 percent for right coronal, left coronal, right lambdoidal, and left lambdoidal sutures, respectively. Lambdoidal sutures had a significantly higher rate of closure than coronal sutures (OR(Closure), 4.3; 95 percent CI, 2.3 to 8.0; p < 0.001); lambdoidal patency significantly changed over time (χ2 = 9.9, p = 0.04). Across craniofacial surgeons, coronal and lambdoidal patency were equivalent. The total sutural patency score did not significantly correlate with postoperative time, surgical age, preoperative cephalic index, or craniofacial surgeon. CONCLUSIONS: Total vault remodeling for isolated sagittal synostosis results in a high degree of secondary craniosynostosis. Lambdoidal sutures are especially prone to closure, with their patency diminishing over time. At this time, radiographic fusion of adjacent sutures following surgery has not been related to any difference in head shape. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV.

Use of propranolol for treatment of infantile haemangiomas in an outpatient setting.

INTRODUCTION: Propranolol has recently emerged as an effective drug treatment for infantile haemangiomas. The side effect profile of the drug and the safety of administering propranolol in outpatient settings in this age group remain uncertain. We report our experience with 200 infants and children prescribed propranolol to treat infantile haemangiomas, including 37 patients considered to have a poor response to treatment. METHOD: Patients were prescribed propranolol (1 mg/kg/dose bd) as outpatients at the Vascular Anomalies Service at the Royal Children's Hospital, Melbourne. RESULTS: The median age at commencement was 4 months (range 5 days-7 years). Twenty patients were older than 12 months at commencement. The median duration of treatment was 8 months. About 80% of treated haemangiomas were on the face. Approximately 50% of patients were considered to have an excellent response, 30% to have a good response and 20% to have a poor response. All segmental facial haemangiomas responded well. In contrast, 25% of focal facial haemangiomas responded poorly. Sleep disturbance was the most common side effect. Gross motor abnormalities including delayed walking were observed in 13 patients. CONCLUSION: Propranolol appears to be an effective treatment for infantile haemangiomas, particularly large segmental facial lesions. A poor response was seen in 20% of patients. Treatment has been provided in an outpatient setting without major complications and with excellent parental compliance. The side effect profile appears to be favourable, but further follow-up is required to identify unexpected long-term side effects.

Perinatal airway management of neonatal cervical teratomas.

Cervical teratomas are rare but life-threatening neonatal tumors and management of the fetus with a cervical teratoma that threatens the airway remains a clinical challenge. This has been revolutionized by advances in fetal imaging and management of the airway at delivery including the use of Ex-utero Intrapartum Treatments (EXIT procedures). We present a retrospective case series of three neonates managed over a 12-month period. Following pre-natal fetal MRI and a multi-disciplinary management approach, two newborns were managed by prompt post-natal endotracheal intubation while an EXIT procedure was required in one. All three underwent surgical resection in the first few days of life. A decision regarding the best means by which to manage the airway in fetal cervical teratoma requires fetal MRI and a multi-disciplinary team approach to determine whether EXIT, or a safer approach from a maternal perspective can be employed. We also recommend routine endotracheal intubation at birth, due to the risk of spontaneous intra-tumoral hemorrhage. The need for surgery should be planned early, as rapid growth of the tumor can threaten the viability of the overlying skin and surrounding structures.

The in vitro preconditioning of myoblasts to enhance subsequent survival in an in vivo tissue engineering chamber model.

The effects of in vitro preconditioning protocols on the ultimate survival of myoblasts implanted in an in vivo tissue engineering chamber were examined. In vitro testing: L6 myoblasts were preconditioned by heat (42 °C; 1.5 h); hypoxia (<8% O(2); 1.5 h); or nitric oxide donors: S-nitroso-N-acetylpenicillamine (SNAP, 200 µM, 1.5 h) or 1-[N-(2-aminoethyl)-N-(2-aminoethyl)amino]-diazen-1-ium-1,2-diolate (DETA-NONOate, 500 µM, 7 h). Following a rest phase preconditioned cells were exposed to 24 h hypoxia, and demonstrated minimal overall cell loss, whilst controls (not preconditioned, but exposed to 24 h hypoxia) demonstrated a 44% cell loss. Phosphoimmunoblot analysis of pro-survival signaling pathways revealed significant activation of serine threonine kinase Akt with DETA-NONOate (p < 0.01) and heat preconditioning (p < 0.05). DETA-NONOate also activated ERK 1/2 signaling (p < 0.05). In vivo implantation: 100,000 preconditioned (heat, hypoxia, or DETA-NONOate) myoblasts were implanted in SCID mouse tissue engineering chambers. 100,000 (not preconditioned) myoblasts were implanted in control chambers. At 3 weeks, morphometric assessment of surviving myoblasts indicated myoblast percent volume (p = 0.012) and myoblasts/mm(2) (p = 0.0005) overall significantly increased in preconditioned myoblast chambers compared to control, with DETA-NONOate-preconditioned myoblasts demonstrating the greatest increase in survival (p = 0.007 and p = 0.001 respectively). DETA-NONOate therefore has potential therapeutic benefits to significantly improve survival of transplanted cells.

A prevascularized tissue engineering chamber supports growth and function of islets and progenitor cells in diabetic mice.

Recent studies have shown that type 1 diabetes can be reversed in a murine model by islet transplantation to a vascularized tissue engineering chamber. In preliminary experiments using a prevascularized chamber we observed that islet grafts not functioning initially can show a delayed onset of function several weeks after implantation. We sought to characterize this phenomenon. Islets were transplanted into prevascularized tissue engineering chambers based on the epigastric vessels in streptozotocin induced diabetic C57BL/6J mice. Animals were transplanted with 500 islets and observed at 1, 4, 8 and 16 weeks post transplantation. Weekly blood glucose (BG) measurements revealed an average onset of maintained graft function 6.8 weeks post transplantation. Graft function was proven by a return to a diabetic state following chamber removal. Mature grafts showed islet tissue clustered together within the tissue construct. The quantity of endocrine tissue staining positive for insulin correlated with graft function at 8 and 16 weeks. However, at 1 and 4 weeks, islet tissue was not evidently visible as observed by endocrine staining. All islet tissue showed dense vascularization and sporadic sympathetic innervation, irrespective of the graft's function. Immunopositive cells for Cytokeratin-7 and -19 were observed in the grafts at early time points and hormone producing cells appear to have been differentiated from these progenitors. Our data demonstrates that pancreatic duct-derived progenitors remain viable in vivo and eventually differentiate and mature to functional islets following transplantation. Our prevascularized tissue-engineering chamber in the groin supports maturation and function of the grafted tissue by two months after implantation.

An "off the shelf" vascular allograft supports angiogenic growth in three-dimensional tissue engineering.

OBJECTIVES: Dense angiogenic sprouting occurs from arteriovenous loops (AVLs) incorporating autologous vein grafts inserted into empty plastic chambers in vivo. The purpose of this study was to determine if angiogenesis from the AVL was limited by substituting an "off the shelf" cold-stored allograft vein instead of an autologous vein. METHODS: Four Sprague Dawley rat groups (two AVL configurations × two chamber types) were established for both 2-week and 6-week harvest. Control AVLs were autologous femoral vein grafts harvested from the left femoral vein that were surgically inserted between the cut femoral artery and vein on the right side. Experimental "allograft" AVLs were rat femoral veins cold-stored (4°C, sterile) for 4 to 7 weeks and then microsurgically interposed between the right femoral artery and vein of an unrelated rat. The two AVL types were inserted in one of two plastic chamber types--smooth or perforated. At harvest, the AVL constructs were checked for patency, weighed, their volume determined, and histology undertaken. Morphometric assessment of percent and absolute volume of major tissue components (including blood vessels) at 6 weeks was completed. RESULTS: There were no significant differences between autograft and allograft groups in construct weight, volume, or morphology at 2 or 6 weeks. No statistical differences occurred in the percent or absolute vascular volume of AVLs incorporating a cold-stored allograft vs autologous vein grafts at 6 weeks regardless of the chamber type. However, perforated chambers caused significant increases in construct weight (P = .015), volume (P = .006), and percent and absolute connective tissue volume at 6 weeks (P = .001) compared to smooth chamber constructs, regardless of the graft type. CONCLUSION: Cold-stored small-caliber allografts interposed in AVLs do not inhibit microcirculatory development and can be used in composite tissue engineering.

Epoxy-amine synthesised hydrogel scaffolds for soft-tissue engineering.

Highly porous and biodegradable hydrogels based on poly(ethylene glycol) (PEG) and cystamine (Cys) were fabricated using epoxy-amine chemistry and investigated as scaffolds for soft-tissue engineering. Whereas the application of fused-salt templates provided a comprehensive interconnecting pore morphology, the incorporation of a specially designed poly(epsilon-caprolactone) (PCL) cross-linker provided enhanced mechanical function without adversely effecting the scaffolds positive biological interactions. The addition of only 1.2 wt% of the PCL cross-linker was sufficient to provide improvements in the ultimate stress of 30-40%. In vitro studies not only confirmed the non-cytotoxic nature of the scaffolds, but also their degradation products, which were isolated and characterised by nuclear magnetic resonance (NMR) and matrix-assisted laser desorption/ionisation time-of-flight mass spectroscopy (MALDI ToF MS). In vivo trials were conducted over a period of 8 weeks through implantation of the scaffolds into the dorsal region of rats. At both 2 and 8 week time points the explants revealed complete infiltration by the surrounding tissue and the development of a vascular network to support the newly generated tissue, without an excessive foreign-body response.

Post-traumatic pseudolipomas--a review and postulated mechanisms of their development.

Post-traumatic pseudolipomas develop in areas of the body that have been subjected to acute, severe, blunt trauma and chronic trauma. This study aimed to review the literature for reports of post-traumatic pseudolipomas on Medline and identify the possible mechanisms of their development. In the literature, 124 such cases were identified relating to case reports and case series; of these, 98 occurred in females and 26 in males. The majority of the cases occurred secondary to severe, acute, blunt trauma. The initial postulated mechanisms for development of post-traumatic pseudolipomas were anatomically and mechanically based. Recently, it was shown that there is a close relationship between inflammation and adipogenesis. Blunt trauma results in an inflammatory process. We postulate that post-traumatic pseudolipoma development occurs as a result of inflammatory triggers and an optimal local milieu at the site of development by making an analogy to an in vivo murine tissue engineering model for neo-adipogenesis.