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Biomedical subjects

Roy M Kimble

Publications and source records attributed to Roy M Kimble.

13 recordsLinked to original sources
PubMed2006

A porcine deep dermal partial thickness burn model with hypertrophic scarring.

We developed a reproducible model of deep dermal partial thickness burn injury in juvenile Large White pigs. The contact burn is created using water at 92 degrees C for 15s in a bottle with the bottom replaced with plastic wrap. The depth of injury was determined by a histopathologist who examined tissue sections 2 and 6 days after injury in a blinded manner. Upon creation, the circular wound area developed white eschar and a hyperaemic zone around the wound border. Animals were kept for 6 weeks or 99 days to examine the wound healing process. The wounds took between 3 and 5 weeks for complete re-epithelialisation. Most wounds developed contracted, purple, hypertrophic scars. On measurement, the thickness of the burned skin was approximately 1.8 times that of the control skin at week 6 and approximately 2.2 times thicker than control skin at 99 days after injury. We have developed various methods to assess healing wounds, including digital photographic analysis, depth of organising granulation tissue, immunohistochemistry, electron microscopy and tensiometry. Immunohistochemistry and electron microscopy showed that our porcine hypertrophic scar appears similar to human hypertrophic scarring. The development of this model allows us to test and compare different treatments on burn wounds.

Animals↗
PubMed2005

Gastroschisis: ward reduction compared with traditional reduction under general anesthesia.

BACKGROUND/PURPOSE: In gastroschisis it is proposed that gut reduction may be achieved without intubation or general anesthesia (GA) through ward reduction. The authors aimed to determine if ward reduction decreased morbidity and duration of treatment. METHODS: Infants born from January 1, 1995, to December 31, 2001, with gastroschisis were managed with either reduction under GA in the operating theatre (OT group)--up to September 1999, or ward reduction (when eligible) in the neonatal unit without GA/ventilation (ward reduction [WR] group)--from September 1999. RESULTS: Of the 37 infants, 31 were eligible for ward reduction-15 from the OT group, 16 from the WR group. All infants in the OT group had at least 1 episode of ventilation and 1 GA: 62% of infants in the WR group avoided ventilation (P = .0002) and 81% avoided GA (P < .0001). Infants who had ward reduction had significantly shorter durations of ventilation and oxygen therapy. Septicemia occurred in 31% of the WR group and 7% of the OT group (P = .17). Infants who had ward reduction left intensive care 16 days earlier (P = .02) and tended to reach full enteral feeds 8 days sooner (P = .06) and be discharged from hospital 15 days earlier (P = .05). CONCLUSIONS: Infants who had ward reduction do better in terms of avoiding GA/ventilation, establishing feeds, and going home earlier. A randomized, controlled trial comparing the 2 approaches is feasible, safe, and worthwhile.

Abdominal Wall↗
PubMed2004

An in vitro study of the anti-microbial efficacy of a 1% silver sulphadiazine and 0.2% chlorhexidine digluconate cream, 1% silver sulphadiazine cream and a silver coated dressing.

UNLABELLED: Burn sepsis is a leading cause of mortality and morbidity in patients with major burns. The use of topical anti-microbial agents has helped improve the survival in these patients. There are a number of anti-microbials available, one of which, Silvazine (1% silver sulphadiazine (SSD) and 0.2% chlorhexidine digluconate), is used only in Australasia. No study, in vitro or clinical, had compared Silvazine with the new dressing Acticoat. This study compared the anti-microbial activity of Silvazine, Acticoat and 1% silver sulphadiazine (Flamazine) against eight common burn wound pathogens. METHODS: Each organism was prepared as a suspension. A 10 microl inoculum of the chosen bacterial isolate (representing approximately between 10(4) and 10(5) total bacteria) was added to each of four vials, followed by samples of each dressing and a control. The broths were then incubated and 10 microl loops removed at specified intervals and transferred onto Horse Blood Agar. These plates were then incubated for 18 hours and a colony count was performed. RESULTS: The data demonstrates that the combination of 1% SSD and 0.2% chlorhexidine digluconate (Silvazine) results in the most effective killing of all bacteria. SSD and Acticoat had similar efficacies against a number of isolates, but Acticoat seemed only bacteriostatic against E. faecalis and methicillin-resistant Staphylococcus aureus. Viable quantities of Enterobacter cloacae and Proteus mirabilis remained at 24h. CONCLUSION: The combination of 1% SSD and 0.2% chlorhexidine digluconate (Silvazine) is a more effective anti-microbial against a number of burn wound pathogens in this in vitro study. A clinical study of its in vivo anti-microbial efficacy is required.

Anti-Infective Agents, Local↗
PubMed2004

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.

Anti-Infective Agents, Local↗
PubMed2004

Treatment of partial-thickness burns: a prospective, randomized trial using Transcyte.

BACKGROUND: The purpose of the present study was to compare the effectiveness of three burns dressings (TransCyte, a bio-engineered skin substitute; Biobrane; and Silvazine cream (silver sulphadiazine and 0.2% chlorhexidine)), in treating children with partial-thickness burns. The primary objective was to determine the days until > or =90% re-epithelialization. The secondary objectives were to evaluate the number of wounds requiring autografting and the number of dressing changes/local wound care required. METHODS: Study wounds were identified on each patient and the patients were randomized to receive TransCyte or Biobrane or Silvazine. Assessment of study wound closure began at 2 days after treatment and continued at least every other day thereafter until the wounds re-epithelialized or were autografted. A laser Doppler imaging system was used as an adjunct to assessing the depth of the burn. RESULTS: Thirty-three patients with 58 wound sites enrolled in the study (TransCyte, n = 20, Biobrane, n = 17; Silvazine, n = 21). Mean time to re-epithelialization was 7.5 days for TransCyte, 9.5 days for Biobrane, and 11.2 days for Silvazine. The number of wounds requiring autografting were 5/21 (24%) for Silvazine, 3/17 (17%) for Biobrane, and 1/20 (5%) for TransCyte. CONCLUSIONS: When used in partial-thickness burns in children, TransCyte promotes fastest re-epithelialization and required less overall dressings then Biobrane or Silvazine. Patients who received Silvazine or Biobrane require more autografting than those treated with TransCyte.

Anti-Infective Agents, Local↗
PubMed2003

The morning after the night before: campfires revisited.

Even eight hours after a campfire has been extinguished with sand, it retains sufficient heat to cause a full-thickness burn with contact of one second. Because extinguishing with sand disguises the danger, this is a particular hazard for children. The only safe way to extinguish a campfire is with water.

Burns↗
PubMed2003

Flammable liquid burns in children.

OBJECTIVES: To document and describe the effects of flammable liquid burns in children. To identify the "at risk" population in order to tailor a burns prevention programme. DESIGN, PATIENTS AND SETTING: Retrospective study with information obtained from the departmental database of children treated at the burns centre at The Royal Children's Hospital, Brisbane between August 1997 and October 2002. MAIN OUTCOME MEASURES: Number and ages of children burned, risk factors contributing to the accident, injuries sustained, treatment required and long-term sequelae. RESULTS: Fifty-nine children sustained flammable liquid burns (median age 10.5 years), with a clear preponderance of males (95%). The median total body surface area burned was 8% (range 0.5-70%). Twenty-seven (46%) of the patients required debridement and grafting. Hypertrophic scars occurred in 56% of the children and contractures in 14%, of which all of the latter required surgical release. Petrol was the causative liquid in the majority (83%) of cases. CONCLUSIONS: The study identified the population most at risk of sustaining flammable liquid burns were young adolescent males. In the majority of cases these injuries were deemed preventable.

Accident Prevention↗
PubMed2002

Campfire burns in children: an Australian experience.

OBJECTIVES: To document and describe the effects of campfire burns on children. To identify the sources of danger contributing to such injuries, so that a prevention strategy can be devised. DESIGN, PATIENTS AND SETTING: Departmental database and case note review of all children with campfire burns seen at the Burns Unit of a tertiary referral children's hospital between January 1999 and June 2001. MAIN OUTCOME MEASURES: Number and ages of children burned; risk factors contributing to the accidents; injuries sustained; treatment required and long-term sequelae. RESULTS: Thirty-three children, median age 2.5 years, sustained burns, usually to the hands and feet, with eight requiring surgery and the majority requiring some form of scar therapy. Seventy-four percent of the children were burned by hot ashes and coals, usually from the previous night's fire, rather than by open flames. CONCLUSIONS: Campfires cause serious injuries to children. In particular, hot ashes and coals from inadequately extinguished campfires pose the greatest danger. Increasing the awareness of this easily preventable problem amongst campers is intended through a public education campaign.

Accidents↗
PubMed2002

Woodstoves uncovered: a paediatric problem.

OBJECTIVES: To document and describe the effects of woodstove burns in children. To identify how these accidents occur so that a prevention strategy can be devised. DESIGN, PATIENTS AND SETTING: Retrospective departmental database and case note review of all children with woodstove burns seen at the Burns Unit of a Tertiary Referral Children's Hospital between January 1997 and September 2001. MAIN OUTCOME MEASURES: Number and ages of children burned; circumstances of the accidents; injuries sustained; treatment required and long-term sequelae. RESULTS: Eleven children, median age 1.0 year, sustained burns, usually to the hands, of varying thickness. Two children required skin grafting and five required scar therapy. Seven children intentionally placed their hands onto the outside of the stove. In all children, burns occurred despite adult supervision. CONCLUSIONS: Woodstoves are a cause of burns in children. These injuries are associated with significant morbidity and financial costs. Through public education, woodstove burns can easily be prevented utilising simple safety measures.

Accident Prevention↗
PubMedDate not supplied

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.

Actins↗
PubMedDate not supplied

Collagen in the scarless fetal skin wound: detection with picrosirius-polarization.

Our group has developed an ovine model of deep dermal, partial-thickness burn where the fetus heals scarlessly and the lamb heals with scar. The comparison of collagen structure between these two different mechanisms of healing may elucidate the process of scarless wound healing. Picrosirius staining followed by polarized light microscopy was used to visualize collagen fibers, with digital capture and analysis. Collagen deposition increased with fetal age and the fibers became thicker, changing from green (type III collagen) to yellow/red (type I collagen). The ratio of type III collagen to type I was high in the fetus (166), whereas the lamb had a much lower ratio (0.2). After burn, the ratios of type III to type I collagen did not differ from those in control skin for either fetus or lamb. The fetal tissue maintained normal tissue architecture after burn while the lamb tissue showed irregular collagen organization. In conclusion, the type or amount of collagen does not alter significantly after injury. Tissue architecture differed between fetal and lamb tissue, suggesting that scar development is related to collagen cross-linking or arrangement. This study indicates that healing in the scarless fetal wound is representative of the normal fetal growth pattern, rather than a "response" to burn injury.

Animals↗