A Review of Petrol Burns in Australia and New Zealand.

Petrol-related thermal burns cause significant morbidity and mortality worldwide and it has been established that they affect young males disproportionately. Beyond this, we sought to identify the difference in the characteristics and outcomes of burns between males and females in an international population. Such differences may highlight areas for future preventative strategies. The Burns Registry of Australia and New Zealand was used. Petrol burns that resulted in a hospital admission in those 16 years or older between January 2010 and December 2019 were included. A total of 2833 patients were included. The median age was 35 years with most patients being male (88%). Burns from a campfire or burnoffs were most common. Females were more likely to suffer burns due to assault or from deliberate self-harm. The total body surface area affected by burns was higher for females than males (10% vs 8%). Furthermore, females more frequently required ICU admission, escharotomies, and had a longer hospital length of stay. The unadjusted mortality rate for females was more than double the rate for males (5.8% vs 2.3%). This international study demonstrates that whilst men more frequently suffer petrol burns, women suffer more severe burns, require more intensive and longer hospitalizations and have a higher mortality rate. These findings may inform changes in preventative health policies globally to mitigate against these concerning findings.

A systematic review of systematic review methodology in plastic surgery journals.

INTRODUCTION: Systematic reviews (SR) and meta-analyses (MA) are described as the top level of evidence in clinical research and are commonplace in plastic surgery literature. Their quality is limited both by the reliability of primary studies and the method of aggregating data. This study analysed the overall quality of SR's in plastic surgery and identified influencing factors. MATERIALS AND METHODS: The paper critically appraised SR's published in three prominent plastic surgery journals between July 2019 and July 2020. Study selection and appraisal was performed in duplicate. Articles were assessed using A Measurement Tool to Assess Systematic Reviews (AMSTAR). RESULTS: Seventy-six studies were included. 52 (68%) were SR's only and 24 (32%) included meta-analysis (MA) as well. The most common subspecialty areas included breast, craniofacial and hand. 78% of studies followed the PRISMA guidelines. The median (min, max) AMSTAR score was 3.5 (0-7). SR's with MA had significantly higher AMSTAR scores (p<0.001) than SR's alone, with median scores of 5 and 3 respectively. Papers from China had significantly higher AMSTAR scores than the USA. Craniofacial SR's had significantly higher scores than all other subspecialty areas. Most SR's reviewed concluded that there is currently inadequate primary research to make a conclusion and recommended more research be carried out in that area. CONCLUSIONS: This systematicreview found overall that the quality of research methodology in Plastic Surgery SRs is low, and their conclusions of limited value. Surgeons should be familiar with SR and MA methodology, so they can exercise better judgement in applying findings to clinical practice.

Targeted Therapy Against the Cell of Origin in Cutaneous Squamous Cell Carcinoma.

Squamous cell carcinomas (SCC), including cutaneous SCCs, are by far the most frequent cancers in humans, accounting for 80% of all newly diagnosed malignancies worldwide. The old dogma that SCC develops exclusively from stem cells (SC) has now changed to include progenitors, transit-amplifying and differentiated short-lived cells. Accumulation of specific oncogenic mutations is required to induce SCC from each cell population. Whilst as fewer as one genetic hit is sufficient to induce SCC from a SC, multiple events are additionally required in more differentiated cells. Interestingly, the level of differentiation correlates with the number of transforming events required to induce a stem-like phenotype, a long-lived potential and a tumourigenic capacity in a progenitor, a transient amplifying or even in a terminally differentiated cell. Furthermore, it is well described that SCCs originating from different cells of origin differ not only in their squamous differentiation status but also in their malignant characteristics. This review summarises recent findings in cutaneous SCC and highlights transforming oncogenic events in specific cell populations. It underlines oncogenes that are restricted either to stem or differentiated cells, which could provide therapeutic target selectivity against heterogeneous SCC. This strategy may be applicable to SCC from different body locations, such as head and neck SCCs, which are currently still associated with poor survival outcomes.

Loss of GRHL3 leads to TARC/CCL17-mediated keratinocyte proliferation in the epidermis.

Identifying soluble factors that influence epidermal integrity is critical for the development of preventative and therapeutic strategies for disorders such as ichthyosis, psoriasis, dermatitis and epidermal cancers. The transcription factor Grainyhead-like 3 (GRHL3) is essential for maintaining barrier integrity and preventing development of cutaneous squamous cell carcinoma (SCC); however, how loss of this factor, which in the skin is expressed exclusively within suprabasal epidermal layers triggers proliferation of basal keratinocytes, had thus far remained elusive. Our present study identifies thymus and activation-regulated chemokine (TARC) as a novel soluble chemokine mediator of keratinocyte proliferation following loss of GRHL3. Knockdown of GRHL3 in human keratinocytes showed that of 42 cytokines examined, TARC was the only significantly upregulated chemokine. Mouse skin lacking Grhl3 presented an inflammatory response with hallmarks of TARC activation, including heightened induction of blood clotting, increased infiltration of mast cells and pro-inflammatory T cells, increased expression of the pro-proliferative/pro-inflammatory markers CD3 and pSTAT3, and significantly elevated basal keratinocyte proliferation. Treatment of skin cultures lacking Grhl3 with the broad spectrum anti-inflammatory 5-aminosalicylic acid (5ASA) partially restored epidermal differentiation, indicating that abnormal keratinocyte proliferation/differentiation balance is a key driver of barrier dysfunction following loss of Grhl3, and providing a promising therapeutic avenue in the treatment of GRHL3-mediated epidermal disorders.

A rare case of failed healing in previously burned skin after a secondary burns.

BACKGROUND: Patients presenting with large surface area burns are common in our practice; however, patients with a secondary large burn on pre-existing burn scars and grafts are rare and not reported. CASE PRESENTATION: We report on an unusual case of a patient sustaining a secondary large burn to areas previously injured by a burn from a different mechanism. We discuss the potential implications when managing a case like this and suggest potential biological reasons why the skin may behave differently. Our patient was a 33-year-old man who presented with a 5% TBSA burn on skin scarred by a previous 40% total body surface area (TBSA) burn and skin grafts. Initially assessed as superficial partial thickness in depth, the wounds were treated conservatively with dressings; however, they failed to heal and became infected requiring surgical management. CONCLUSIONS: Burns sustained in areas of previous burn scars and grafts may behave differently to normal patterns of healing, requiring more aggressive management and surgical intervention at an early stage.

Mice lacking the conserved transcription factor Grainyhead-like 3 (Grhl3) display increased apposition of the frontal and parietal bones during embryonic development.

BACKGROUND: Increased apposition of the frontal and parietal bones of the skull during embryogenesis may be a risk factor for the subsequent development of premature skull fusion, or craniosynostosis. Human craniosynostosis is a prevalent, and often serious embryological and neonatal pathology. Other than known mutations in a small number of contributing genes, the aetiology of craniosynostosis is largely unknown. Therefore, the identification of novel genes which contribute to normal skull patterning, morphology and premature suture apposition is imperative, in order to fully understand the genetic regulation of cranial development. RESULTS: Using advanced imaging techniques and quantitative measurement, we show that genetic deletion of the highly-conserved transcription factor Grainyhead-like 3 (Grhl3) in mice (Grhl3 -/- ) leads to decreased skull size, aberrant skull morphology and premature apposition of the coronal sutures during embryogenesis. Furthermore, Grhl3 -/- mice also present with premature collagen deposition and osteoblast alignment at the sutures, and the physical interaction between the developing skull, and outermost covering of the brain (the dura mater), as well as the overlying dermis and subcutaneous tissue, appears compromised in embryos lacking Grhl3. Although Grhl3 -/- mice die at birth, we investigated skull morphology and size in adult animals lacking one Grhl3 allele (heterozygous; Grhl3 +/- ), which are viable and fertile. We found that these adult mice also present with a smaller cranial cavity, suggestive of post-natal haploinsufficiency in the context of cranial development. CONCLUSIONS: Our findings show that our Grhl3 mice present with increased apposition of the frontal and parietal bones, suggesting that Grhl3 may be involved in the developmental pathogenesis of craniosynostosis.

Integrative genomic and functional analysis of human oral squamous cell carcinoma cell lines reveals synergistic effects of FAT1 and CASP8 inactivation.

Oral squamous cell carcinoma (OSCC) is genetically highly heterogeneous, which contributes to the challenges of treatment. To create an in vitro model that accurately reflects this heterogeneity, we generated a panel of HPV-negative OSCC cell lines. By whole exome sequencing of the lines and matched patient blood samples, we demonstrate that the mutational spectrum of the lines is representative of primary OSCC in The Cancer Genome Atlas. We show that loss of function mutations in FAT1 (an atypical cadherin) and CASP8 (Caspase 8) frequently occur in the same tumour. OSCC cells with inactivating FAT1 mutations exhibited reduced intercellular adhesion. Knockdown of FAT1 and CASP8 individually or in combination in OSCC cells led to increased cell migration and clonal growth, resistance to Staurosporine-induced apoptosis and, in some cases, increased terminal differentiation. The OSCC lines thus represent a valuable resource for elucidating the impact of different mutations on tumour behaviour.

Extending the use of the gracilis muscle flap in perineal reconstruction surgery.

Reconstruction of the perineum is required following oncological resections. Plastic surgical techniques can be used to restore the aesthetics and function of the perineum. The gracilis myocutaneous flap provides a substantial skin paddle, with minimal donor site morbidity. The flap is pedicled on a perforator from the medial circumflex femoral artery, giving it limited reach across the perineum. Tunnelling the flap under the adductor longus muscle may free up more of the arterial pedicle, increasing its reach. On three female cadavers, bilateral gracilis flaps were raised in the standard surgical manner, giving six flaps in total. With the flaps pedicled across the perineum, the distance from the tip of each flap was measured to the anterior superior iliac spine (ASIS). The flaps were then tunnelled under the adductor longus muscle. The distances to the ASIS were measured again. The average pedicle length was greater than 7 cm. Tunnelling the flap under the adductor longus muscle increased the reach by more than 4 cm on average. Cadaveric dissection has shown that tunnelling of the flap in a novel way increase its reach across the perineum. This additional flexibility improves its use clinically and is of benefit to plastic surgeons operating in perineal reconstruction.

A cellular model reflecting the phenotypic heterogeneity of mutant HRAS driven squamous cell carcinoma.

Squamous cell carcinomas have a range of histopathological manifestations. The parameters that determine this clinically observed heterogeneity are not fully understood. Here, we report the generation of a cell culture model that reflects part of this heterogeneity. We have used the catalytic subunit of human telomerase hTERT and large T to immortalize primary UV-unexposed keratinocytes. Then, mutant HRAS G12V has been introduced to transform these immortal keratinocytes. When injected into immunosuppressed mice, transformed cells grew as xenografts with distinct histopathological characteristics. We observed three major tissue architectures: solid, sarcomatoid and cystic growth types, which were primarily composed of pleomorphic and basaloid cells but in some cases displayed focal apocrine differentiation. We demonstrate that the cells generated represent different stages of skin cancerogenesis and as such can be used to identify novel tumor-promoting alterations such as the overexpression of the PADI2 oncogene in solid-type SCC. Importantly, the cultured cells maintain the characteristics from the xenograft they were derived from while being amenable to manipulation and analysis. The availability of cell lines representing different clinical manifestations opens a new tool to study the stochastic and deterministic factors that cause case-to-case heterogeneity despite departing from the same set of oncogenes and the same genetic background.

Use of 3D printed models in medical education: A randomized control trial comparing 3D prints versus cadaveric materials for learning external cardiac anatomy.

Three-dimensional (3D) printing is an emerging technology capable of readily producing accurate anatomical models, however, evidence for the use of 3D prints in medical education remains limited. A study was performed to assess their effectiveness against cadaveric materials for learning external cardiac anatomy. A double blind randomized controlled trial was undertaken on undergraduate medical students without prior formal cardiac anatomy teaching. Following a pre-test examining baseline external cardiac anatomy knowledge, participants were randomly assigned to three groups who underwent self-directed learning sessions using either cadaveric materials, 3D prints, or a combination of cadaveric materials/3D prints (combined materials). Participants were then subjected to a post-test written by a third party. Fifty-two participants completed the trial; 18 using cadaveric materials, 16 using 3D models, and 18 using combined materials. Age and time since completion of high school were equally distributed between groups. Pre-test scores were not significantly different (P = 0.231), however, post-test scores were significantly higher for 3D prints group compared to the cadaveric materials or combined materials groups (mean of 60.83% vs. 44.81% and 44.62%, P = 0.010, adjusted P = 0.012). A significant improvement in test scores was detected for the 3D prints group (P = 0.003) but not for the other two groups. The finding of this pilot study suggests that use of 3D prints do not disadvantage students relative to cadaveric materials; maximally, results suggest that 3D may confer certain benefits to anatomy learning and supports their use and ongoing evaluation as supplements to cadaver-based curriculums. Anat Sci Educ 9: 213-221. © 2015 American Association of Anatomists.

The Role of Sonic Hedgehog in Craniofacial Patterning, Morphogenesis and Cranial Neural Crest Survival.

Craniofacial defects (CFD) are a significant healthcare problem worldwide. Understanding both the morphogenetic movements which underpin normal facial development, as well as the molecular factors which regulate these processes, forms the cornerstone of future diagnostic, and ultimately, preventative therapies. The soluble morphogen Sonic hedgehog (Shh), a vertebrate orthologue of Drosophila hedgehog, is a key signalling factor in the regulation of craniofacial skeleton development in vertebrates, operating within numerous tissue types in the craniofacial primordia to spatiotemporally regulate the formation of the face and jaws. This review will provide an overview of normal craniofacial skeleton development, and focus specifically on the known roles of Shh in regulating the development and progression of the first pharyngeal arch, which in turn gives rise to both the upper jaw (maxilla) and lower jaw (mandible).

Rewiring of an epithelial differentiation factor, miR-203, to inhibit human squamous cell carcinoma metastasis.

Metastatic colonization of distant organs underpins the majority of human-cancer-related deaths, including deaths from head and neck squamous cell carcinoma (HNSCC). We report that miR-203, a miRNA that triggers differentiation in multilayered epithelia, inhibits multiple postextravasation events during HNSCC lung metastasis. Inducible reactivation of miR-203 in already established lung metastases reduces the overall metastatic burden. Using an integrated approach, we reveal that miR-203 inhibits metastasis independently of its effects on differentiation. In vivo genetic reconstitution experiments show that miR-203 inhibits lung metastasis by suppressing the prometastatic activities of three factors involved in cytoskeletal dynamics (LASP1), extracellular matrix remodeling (SPARC), and cell metabolism (NUAK1). Expression of miR-203 and its downstream effectors correlates with HNSCC overall survival outcomes, indicating the therapeutic potential of targeting this signaling axis.

Sox2 modulates the function of two distinct cell lineages in mouse skin.

In postnatal skin the transcription factor Sox2 is expressed in the dermal papilla (DP) of guard/awl/auchene hair follicles and by mechanosensory Merkel cells in the touch domes of guard hairs. To investigate the consequences of Sox2 ablation in skin we deleted Sox2 in DP cells via Blimp1Cre and in Merkel cells via K14Cre. Loss of Sox2 from the DP did not inhibit hair follicle morphogenesis or establishment of the dermis and hypodermis. However, Sox2 expression in the DP was necessary for postnatal maintenance of awl/auchene hair follicles. Deletion of Sox2 via K14Cre resulted in a decreased number of Merkel cells but had no effect on other epithelial compartments or on the dermis. The reduced number of Merkel cells did not affect the number or patterning of guard hairs, nerve density or the interaction of nerve cells with the touch domes. We conclude that Sox2 is a marker of two distinct lineages in the skin and regulates the number of differentiated cells in the case of the Merkel cell lineage and hair follicle type in the case of the DP.

FRMD4A upregulation in human squamous cell carcinoma promotes tumor growth and metastasis and is associated with poor prognosis.

New therapeutic strategies are needed to improve treatment of head and neck squamous cell carcinoma (HNSCC), an aggressive tumor with poor survival rates. FRMD4A is a human epidermal stem cell marker implicated previously in epithelial polarity that is upregulated in SCC cells. Here, we report that FRMD4A upregulation occurs in primary human HNSCCs where high expression levels correlate with increased risks of relapse. FRMD4A silencing decreased growth and metastasis of human SCC xenografts in skin and tongue, reduced SCC proliferation and intercellular adhesion, and stimulated caspase-3 activity and expression of terminal differentiation markers. Notably, FRMD4A attenuation caused nuclear accumulation of YAP, suggesting a potential role for FRMD4A in Hippo signaling. Treatment with the HSP90 inhibitor 17-DMAG or ligation of CD44 with hyaluronan caused nuclear depletion of FRMD4A, nuclear accumulation of YAP and reduced SCC growth and metastasis. Together, our findings suggest FRMD4A as a novel candidate therapeutic target in HNSCC based on the key role in metastatic growth we have identified.

Mimicking normal tissue architecture and perturbation in cancer with engineered micro-epidermis.

Correct tissue architecture is essential for normal physiology, yet there have been few attempts to recreate tissues using micro-patterning. We have used polymer brush micro-engineering to generate a stratified micro-epidermis with fewer than 10 human keratinocytes. Epidermal stem cells are captured on 100 µm diameter circular collagen-coated disks. Within 24 h they assemble a stratified micro-tissue, in which differentiated cells have a central suprabasal location. For rings with a non-adhesive centre of up to 40 µm diameter, cell-cell and cell-matrix adhesive interactions together result in correct micro-epidermis assembly. Assembly requires actin polymerization, adherens junctions and desmosomes, but not myosin II-mediated contractility nor coordinated cell movement. Squamous cell carcinoma cells on micro-patterned rings exhibit disturbed architecture that correlates with the characteristics of the original tumours. The micro-epidermis we have generated provides a new platform for screening drugs that modulate tissue assembly, quantifying tissue stratification and investigating the properties of tumour cells.