Human immature dental pulp stem cells share key characteristic features with limbal stem cells

Objectives: Limbal stem cells (LSC) are self-renewing, highly proliferative cells in vitro, which express a set of specific markers and in vivo have the capacity to reconstruct the entire corneal epithelium in cases of ocular surface injury. Currently, LSC transplantation is a commonly used procedure in patients with either uni- or bilateral total limbal stem cells deficiency (TLSCD). Although LSC transplantation holds great promise for patients, several problems need to be overcome. In order to find an alternative source of cells that can partially substitute LSC in cornea epithelium reconstruction, we aimed at investigating whether human immature dental pulp stem cells (hIDPSC) would present similar key characteristics as LSC and whether they could be used for corneal surface reconstruction in a rabbit TLSCD model. Materials: We used hIDPSC, which co-express mesenchymal and embryonic stem cell markers and present the capacity to differentiate into derivative cells of the three germinal layers. TLSCD was induced by chemical burn in one eye of rabbits. After 30 days, the opaque tissue formed was removed by superficial keratectomy. Experimental group received undifferentiated hIDPSC, while control group only received amniotic membrane (AM). Both groups were sacrificed after 3 months. Results and conclusions: We have demonstrated, using immunohistochemistry and reverse transcription-polymerase chain reaction, that hIDPSCs express markers in common with LSC, such as ABCG2, integrin beta 1, vimentin, p63, connexin 43 and cytokeratins 3/12. They were also capable of reconstructing the eye surface after induction of unilateral TLSCD in rabbits, as shown by morphological and immunohistochemical analysis using human-specific antibodies against limbal and corneal epithelium. Our data suggest that hIDPSCs share similar characteristics with LSC and might be used as a potential alternative source of cells for corneal reconstruction.

Performance of a transmutation advanced device for sustainable energy application

Preliminary studies have been performed to design a device for nuclear waste transmutation and hydrogen generation based on a gas-cooled pebble bed accelerator driven system, TADSEA (Transmutation Advanced Device for Sustainable Energy Application). In previous studies we have addressed the viability of an ADS Transmutation device that uses as fuel wastes from the existing LWR power plants, encapsulated in graphite in the form of pebble beds, cooled by helium which enables high temperatures (in the order of 1200 K), to generate hydrogen from water either by high temperature electrolysis or by thermochemical cycles. For designing this device several configurations were studied, including several reflectors thickness, to achieve the desired parameters, the transmutation of nuclear waste and the production of 100 MW of thermal power. In this paper new studies performed on deep burn in-core fuel management strategy for LWR waste are presented. The fuel cycle on TADSEA device has been analyzed based on both: driven and transmutation fuel that had been proposed by the General Atomic design of a gas turbine-modular helium reactor. The transmutation results of the three fuel management strategies, using driven, transmutation and standard LWR spent fuel were compared, and several parameters describing the neutron performance of TADSEA nuclear core as the fuel and moderator temperature reactivity coefficients and transmutation chain, are also presented

Implantação de planos de fogo controlado na gestão dos recursos alimentares para cavalos da raça Garrana em Valença

Dissertação apresentada à Escola Superior Agrária do Instituto Politécnico de Castelo Branco para cumprimento dos requisitos necessários à obtenção do grau de Mestre em Tecnologias e Sustentabilidade dos Sistema Florestais.

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This sheet, printed in Spanish, shows what is legal and not legal to burn in South Carolina. Burning trash is illegal in South Carolina. State law requires that you notify the S.C. Forestry Commission before you burn certain vegetative materials. There are some clean, easy ways to get rid of garbage such as mulching or recycling.

Heat effects of promoters and determination of burn criterion in promoted combustion testing

Promoted ignition testing (NASA) Test 17) [1] is used to determine the relative flammability of metal rods in oxygen-enriched atmospheres. A promotor is used to ignite a metal sample rod, initiating sample burning. If a predetermined length of the sample burns, beyond the promotor, the material is considered flammable at the condition tested. Historically, this burn length has been somewhat arbitrary. Experiments were performed to better understand this test by obtaining insight into the effect a burning promotor has on the preheating of a test sample. Test samples of several metallic materials were prepared and coupled to fast-responding thermocouples along their length. Thermocouple measurements and test video were synchronized to determine temperature increase with respect to time and length along each test sample. A recommended flammability burn length, based on a sample preheat of 500 degrees fahrenheit, was determined based on the preheated zone measured from these tests. This length was determined to be 30 mm (1.18 in.). Validation of this length and its rationale are presented.

Utilising hospital data to inform product safety prioritisation : the application of RAPEX severity rankings in ICD-coded burn data

Background The implementation of the Australian Consumer Law in 2011 highlighted the need for better use of injury data to improve the effectiveness and responsiveness of product safety (PS) initiatives. In the PS system, resources are allocated to different priority issues using risk assessment tools. The rapid exchange of information (RAPEX) tool to prioritise hazards, developed by the European Commission, is currently being adopted in Australia. Injury data is required as a basic input to the RAPEX tool in the risk assessment process. One of the challenges in utilising injury data in the PS system is the complexity of translating detailed clinical coded data into broad categories such as those used in the RAPEX tool. Aims This study aims to translate hospital burns data into a simplified format by mapping the International Statistical Classification of Disease and Related Health Problems (Tenth Revision) Australian Modification (ICD-10-AM) burn codes into RAPEX severity rankings, using these rankings to identify priority areas in childhood product-related burns data. Methods ICD-10-AM burn codes were mapped into four levels of severity using the RAPEX guide table by assigning rankings from 1-4, in order of increasing severity. RAPEX rankings were determined by the thickness and surface area of the burn (BSA) with information extracted from the fourth character of T20-T30 codes for burn thickness, and the fourth and fifth characters of T31 codes for the BSA. Following the mapping process, secondary data analysis of 2008-2010 Queensland Hospital Admitted Patient Data Collection (QHAPDC) paediatric data was conducted to identify priority areas in product-related burns. Results The application of RAPEX rankings in QHAPDC burn data showed approximately 70% of paediatric burns in Queensland hospitals were categorised under RAPEX levels 1 and 2, 25% under RAPEX 3 and 4, with the remaining 5% unclassifiable. In the PS system, prioritisations are made to issues categorised under RAPEX levels 3 and 4. Analysis of external cause codes within these levels showed that flammable materials (for children aged 10-15yo) and hot substances (for children aged <2yo) were the most frequently identified products. Discussion and conclusions The mapping of ICD-10-AM burn codes into RAPEX rankings showed a favourable degree of compatibility between both classification systems, suggesting that ICD-10-AM coded burn data can be simplified to more effectively support PS initiatives. Additionally, the secondary data analysis showed that only 25% of all admitted burn cases in Queensland were severe enough to trigger a PS response.

Utilising hospital data to inform product safety prioritisation : the application of RAPEX severity rankings in ICD-coded Burn Data

Background The implementation of the Australian Consumer Law in 2011 highlighted the need for better use of injury data to improve the effectiveness and responsiveness of product safety (PS) initiatives. In the PS system, resources are allocated to different priority issues using risk assessment tools. The rapid exchange of information (RAPEX) tool to prioritise hazards, developed by the European Commission, is currently being adopted in Australia. Injury data is required as a basic input to the RAPEX tool in the risk assessment process. One of the challenges in utilising injury data in the PS system is the complexity of translating detailed clinical coded data into broad categories such as those used in the RAPEX tool. Aims This study aims to translate hospital burns data into a simplified format by mapping the International Statistical Classification of Disease and Related Health Problems (Tenth Revision) Australian Modification (ICD-10-AM) burn codes into RAPEX severity rankings, using these rankings to identify priority areas in childhood product-related burns data. Methods ICD-10-AM burn codes were mapped into four levels of severity using the RAPEX guide table by assigning rankings from 1-4, in order of increasing severity. RAPEX rankings were determined by the thickness and surface area of the burn (BSA) with information extracted from the fourth character of T20-T30 codes for burn thickness, and the fourth and fifth characters of T31 codes for the BSA. Following the mapping process, secondary data analysis of 2008-2010 Queensland Hospital Admitted Patient Data Collection (QHAPDC) paediatric data was conducted to identify priority areas in product-related burns. Results The application of RAPEX rankings in QHAPDC burn data showed approximately 70% of paediatric burns in Queensland hospitals were categorised under RAPEX levels 1 and 2, 25% under RAPEX 3 and 4, with the remaining 5% unclassifiable. In the PS system, prioritisations are made to issues categorised under RAPEX levels 3 and 4. Analysis of external cause codes within these levels showed that flammable materials (for children aged 10-15yo) and hot substances (for children aged <2yo) were the most frequently identified products. Discussion and conclusions The mapping of ICD-10-AM burn codes into RAPEX rankings showed a favourable degree of compatibility between both classification systems, suggesting that ICD-10-AM coded burn data can be simplified to more effectively support PS initiatives. Additionally, the secondary data analysis showed that only 25% of all admitted burn cases in Queensland were severe enough to trigger a PS response.

Predictors of re-epithelialization in pediatric burn

INTRODUCTION An important treatment goal for burn wounds is to promote early wound closure. This study identifies factors associated with delayed re-epithelialization following pediatric burn. METHODS Data were collected from August 2011 to August 2012, at a pediatric tertiary burn center. A total of 106 burn wounds were analyzed from 77 participants aged 4-12 years. Percentage of wound re-epithelialization at each dressing change was calculated using Visitrak. Mixed effect regression analysis was performed to identify the demographic factors, wound and clinical characteristics associated with delayed re-epithelialization. RESULTS Burn depth determined by laser Doppler imaging, ethnicity, pain scores, total body surface area (TBSA), mechanism of injury and days taken to present to the burn center were significant predictors of delayed re-epithelialization, accounting for 69% of variance. Flame burns delayed re-epithelialization by 39% compared to all other mechanisms (p=0.003). When initial presentation to the burn center was on day 5, burns took an average of 42% longer to re-epithelialize, compared to those who presented on day 2 post burn (p<0.000). Re-epithelialization was delayed by 14% when pain scores were reported as 10 (on the FPS-R), compared to 4 on the first dressing change (p=0.015) for children who did not receive specialized preparation/distraction intervention. A larger TBSA was also a predictor of delayed re-epithelialization (p=0.030). Darker skin complexion re-epithelialized 25% faster than lighter skin complexion (p=0.001). CONCLUSIONS Burn depth, mechanism of injury and TBSA are always considered when developing the treatment and surgical management plan for patients with burns. This study identifies other factors influencing re-epithelialization, which can be controlled by the treating team, such as effective pain management and rapid referral to a specialized burn center, to achieve optimal outcomes.

Biological markers of stress in pediatric acute burn injury

BACKGROUND Burns and their associated wound care procedures evoke significant stress and anxiety, particularly for children. Little is known about the body's physiological stress reactions throughout the stages of re-epithelialization following an acute burn injury. Previously, serum and urinary cortisol have been used to measure stress in burn patients, however these measures are not suitable for a pediatric burn outpatient setting. AIM To assess the sensitivity of salivary cortisol and sAA in detecting stress during acute burn wound care procedures and to investigate the body's physiological stress reactions throughout burn re-epithelialization. METHODS Seventy-seven participants aged four to thirteen years who presented with an acute burn injury to the burn center at the Royal Children's Hospital, Brisbane, Australia, were recruited between August 2011 and August 2012. RESULTS Both biomarkers were responsive to the stress of burn wound care procedures. sAA levels were on average 50.2U/ml higher (p<0.001) at 10min post-dressing removal compared to baseline levels. Salivary cortisol levels showed a blunted effect with average levels at ten minutes post dressing removal decreasing by 0.54nmol/L (p<0.001) compared to baseline levels. sAA levels were associated with pain (p=0.021), no medication (p=0.047) and Child Trauma Screening Questionnaire scores at three months post re-epithelialization (p=0.008). Similarly, salivary cortisol was associated with no medication (p<0.001), pain scores (p=0.045) and total body surface area of the burn (p=0.010). CONCLUSION Factors which support the use of sAA over salivary cortisol to assess stress during morning acute burn wound care procedures include; sensitivity, morning clinic times relative to cortisol's diurnal peaks, and relative cost.

Efficacy of a children's procedural preparation and distraction device on healing in acute burn wound care procedures : study protocol for a randomized controlled trial

BACKGROUND: The intense pain and anxiety triggered by burns and their associated wound care procedures are well established in the literature. Non-pharmacological intervention is a critical component of total pain management protocols and is used as an adjunct to pharmacological analgesia. An example is virtual reality, which has been used effectively to dampen pain intensity and unpleasantness. Possible links or causal relationships between pain/anxiety/stress and burn wound healing have previously not been investigated. The purpose of this study is to investigate these relationships, specifically by determining if a newly developed multi-modal procedural preparation and distraction device (Ditto) used during acute burn wound care procedures will reduce the pain and anxiety of a child and increase the rate of re-epithelialization. METHODS/DESIGN: Children (4 to 12 years) with acute burn injuries presenting for their first dressing change will be randomly assigned to either the (1) Control group (standard distraction) or (2) Ditto intervention group (receiving Ditto, procedural preparation and Ditto distraction). It is intended that a minimum of 29 participants will be recruited for each treatment group. Repeated measures of pain intensity, anxiety, stress and healing will be taken at every dressing change until complete wound re-epithelialization. Further data collection will aid in determining patient satisfaction and cost effectiveness of the Ditto intervention, as well as its effect on speed of wound re-epithelialization. DISCUSSION: Results of this study will provide data on whether the disease process can be altered by reducing stress, pain and anxiety in the context of acute burn wounds. TRIAL REGISTRATION: ACTRN12611000913976.

Cytotoxicity of topical antimicrobial agents used in burn wounds in Australasia

BACKGROUND: Burn sepsis is a leading cause of mortality and morbidity in patients with major burns. The use of topical antimicrobial agents has helped improve the survival of these patients. Silvazine (Sigma Pharmaceuticals, Melbourne, Australia) (1% silver sulphadiazine and 0.2% chlorhexidine digluconate) is used exclusively in Australasia, and there is no published study on its cytotoxicity. This study compared the relative cytotoxicity of Silvazine with 1% silver sulphadiazine (Flamazine (Smith & Nephew Healthcare, Hull, UK)) and a silver-based dressing (Acticoat (Smith & Nephew Healthcare, Hull, UK)). METHODS: Dressings were applied to the centre of culture plates that were then seeded with keratinocytes at an estimated 25% confluence. The plates were incubated for 72 h and culture medium and dressings then removed. Toluidine blue was added to stain the remaining keratinocytes. Following removal of the dye, the plates were photographed under standard conditions and these digital images were analysed using image analysis software. Data was analysed using Student's t-test. RESULTS: In the present study, Silvazine is the most cytotoxic agent. Seventy-two hour exposure to Silvazine in the present study results in almost no keratinocyte survival at all and a highly statistically significant reduction in cell survival relative to control, Acticoat and Flamazine (P<0.001, P<0.01, P<0.01, respectively). Flamazine is associated with a statistically significant reduction in cell numbers relative to control (P<0.05), but is much less cytotoxic than Silvazine (P<0.005). CONCLUSION: In this in-vitro study comparing Acticoat, Silvazine and Flamazine, Silvazine shows an increased cytotoxic effect, relative to control, Flamazine and Acticoat. An in-vivo study is required to determine whether this effect is carried into the clinical setting.

Deep dermal burn injury results in scarless wound healing in the ovine fetus

Early to mid-term fetuses heal cutaneous incisional wounds without scars; however, fetal response to burn injury has not been ascertained. We present a fetal model of thermal injury and subsequent analysis of fetal and lamb response to burn injury. A reproducible deep dermal burn injury was created in the fetus by application of water at 66 degrees C for 7 seconds, and at 82 degrees C for 10 seconds to the lamb. Macroscopically, the area of fetal scald was undetectable from day 7 post injury, while all lamb scalds were readily identified and eventually healed with scarring. Using a five-point histopathology scoring system for alteration in tissue morphology, differences were detected between control and scalded skin at all stages in lamb postburn, but no difference was detected in the fetal model after day 7. There were also large differences in content of alpha-smooth muscle actin and transforming growth factor-beta1 between control and scalded lamb and these differences were statistically significant at day 14 (P < 0.01). This novel model of fetal and lamb response to deep dermal injury indicates that the fetus heals a deep burn injury in a scarless fashion. Further elucidation of this specific fetal process of burn injury repair may lead to improved outcome for patients with burn injury.