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A novel murine model of isolated skin radiation injury
Vol. 207, No. 3S, September 2008
pair, suggesting that Wnt signaling may play a role in fetal scaring. Our continuing studies will focus on disrupting the Wnt pathway post-wounding and delineating which Wnt proteins are up-regulated after injury.
Modulation of cutaneous scarring in a liquid environment in the Yorkshire pig Richard G Reish BS, Baraa Zuhaili MD, Emily C Waisbren BS, Juri Bergmann MD, Pejman Aflaki MD, Taro Koyama MD, PhD, Feng Yao PhD, Elof Eriksson MD, PhD, FACS Brigham and Women’s Hospital, Division of Plastic Surgery, Boston, MA INTRODUCTION: There have been limited animal models of scarring. It was hypothesized that decreased inflammatory response seen in wet wound healing is correlated with diminished scarring. This study seeks to test this hypothesis and to validate a model of scarring in the liquid environment in the Yorkshire pig. METHODS: Three Yorkshire pigs were used to create 36 dorsal wounds per pig (108 wounds total) in the following groups: full thickness excisional, partial thickness, meshed STSG, sheet STSG, minced skin, and incisional wounds. Wounds were randomized into wet and dry groups. Wet wounds were enclosed in polyurethane chambers with 2 ml of normal saline. Dry wounds were covered with regular gauze. All wounds were converted to dry healing after two weeks. On day 28, terminal biopsies were performed. RESULTS: The mean macroscopic scar surface area was significantly decreased in full thickness excisional wet wounds compared to dry wounds (61.2 mm2 vs 150.8 mm2, p⬍0.01). H&E and trichrome histology demonstrated significantly less inflammatory infiltrate, thicker neoepidermis, more pronounced rete ridge formation, and less scar tissue thickness in wet wounds. Hydroxyproline content was decreased in full thickness wet compared to dry groups (44.81mg/g vs 62.21mg/g, p⬍0.01). Tensile strength was 90% greater in all full thickness wet compared to dry groups (p⬍0.01). CONCLUSIONS: Healing in the liquid environment significantly reduced macroscopic scar surface area, histological evidence of scar, hydroxyproline content, and increased the wound tensile strength. This model will allow for future investigation of high- dose topical scar modulating agents in the liquid environment.
A novel relational database for clinical outcomes in patients with diabetic foot ulcers: The wound electronic medical record (WEMR) Michael Samuel Golinko MD, MA, Eashwar Chandrasekaran MS, Dalton Cox BA, Stephan Barrientos MD, Sasa Vukelic, Harold Brem MD, FACS Columbia University Medical Center, New York, NY INTRODUCTION: Diabetic foot ulcers (DFUs) occur in up to 25% of patients with diabetes, and of these, up to 24 % of ulcers will end in amputation. Our hypothesis is that clinical outcomes of a university based clinical practice can be measured by capturing clinically relevant data using a relational database.
Surgical Forum Abstracts
S61
METHODS: The three year experience of a single university based wound center 146 patients with 170 target diabetic foot ulcers were evaluated. At baseline and at each subsequent visit, all clinical information including laboratory values and wound area were entered into a custom-designed relational database known as the wound electronic medical record (WEMR); amputation was the primary outcomes measure. RESULTS: 19 (12.9%) patients underwent an amputation. A total of 32 amputations were performed in 23 limbs (9 major, 23 minor). Characteristics such as age, sex, HbA1c%, cholesterol, white blood cell count, initial wound area, follow-up time were not significantly different between the amputees and non-amputees (p⬎0.05). Baseline albumin was significantly lower in the amputee group, (3.5 ⫾0.6 vs. 3.9 ⫾1.1 mg/dl, p⫻0.02) Non-amputated patients had significantly more visits to the clinic (p⫻0.02). Wound Characteristics # WEMR records amputation free visits)
Amputees (nⴛ23) 4.6 ⫾ 3.6, 3.0
Non-amputees Significance (nⴛ147) (pⴛ) 6.7 ⫾ 6.3, 4
0.023
Initial area (cm )
15.2 ⫾ 22.3, 5.4
6.8 ⫾ 9.1, 3.1
0.084
Area at 4 weeks (cm2)
17.8 ⫾ 23.4, 5.9
6.7 ⫾ 9.6, 2.7
0.064
2
Area at last visit (cm2)
18.2 ⫾ 25.9, 5.6
4.8 ⫾ 8.3, 1.1
0.020
Mean treatment time or time to amputation (days)
93.4 ⫾ 110.6, 53
131.4 ⫾ 168, 66
0.167
CONCLUSIONS: At a single center, lower albumin, larger wound area, and fewer visits to the wound center may be associated with subsequent amputation. This study demonstrates that outcomes data can be reported using a wound electronic medical record and may be used track amputations. Future study is needed to determine how such a system can be used to alert the clinician to a non-healing wound in order to prevent amputations.
A novel murine model of isolated skin radiation injury Phuong D Nguyen MD, Richard A Zoumalan MD, Christopher C Chang BA, Robert J Allen, Jr. MD, Alexander M Sailon BA, Stephen M Warren MD, FACS, Jamie P Levine MD, FACS, Pierre B Saadeh MD New York University School of Medicine, New York, NY INTRODUCTION: Radiation (XRT), an indispensable modality in the treatment of head and neck cancer, is associated with unavoidable sequelae, including skin fibrosis, which pose a challenge for the ablative and reconstructive surgeon. We present a novel murine model of isolated skin radiation injury, a prerequisite to the development of ameliorative interventions. METHODS: The dorsal skin of adult wild-type FVB mice was isolated with a low-pressure, non-ischemic clamp (rest of mouse was lead-shielded) and exposed to one dose of 30, 45, or 55Gy. XRT monitors measured scatter. Skin changes were assessed postirradiation by Doppler ultrasonography, gross evaluation, hematoxylin & eosin (H&E), Sirius red staining, and immunohistochemistry for SMAD3 weekly for 12 weeks. Peripheral blood smears were also performed. Controls were not irradiated.
S62
Surgical Forum Abstracts
RESULTS: All mice tolerated irradiation, with negligible XRT scatter. At 45 and 55Gy, skin was visibly erythematous and thickened by one week, while ulceration variably occurred by two weeks. Doppler ultrasonography demonstrated decreased (approximately 50%) dorsal skin perfusion by two weeks. H&E revealed increased dermal thickness and fibroblastic proliferation. Sirius red staining confirmed increased collagen deposition. SMAD3 levels were increased by two weeks and remained elevated thereafter. The 30Gy group yielded results similar to non-irradiated controls. Peripheral blood smears did not suggest bone marrow abnormality. CONCLUSIONS: This novel murine model of XRT injury is the first to isolate injury to the skin allowing delivery of doses otherwise lethal to mice. We found 45Gy was the minimal dose resulting in unambiguous and consistent injury. Moreover, the injuries sustained were analogous to human XRT injuries grossly and histologically.
Application of the engineered CXCL12 plasmid to diabetic mouse wounds accelerates healing to near normal via stem cell trafficking Terry Restivo DO, MA, Kimberly Mace PhD, Alden H Harken MD, FACS, David M Young MD, FACS UCSF-Surgical Laboratory, San Rafael, CA INTRODUCTION: The chemokine CXCL12 influences survival, production and trafficking of stem cells. We hypothesize that by
J Am Coll Surg
increasing the level of CXCL12 in the diabetic wound, we would accelerate time to wound closure. This series of experiments aims to: 1) assess the post-wounding expression of the chemokine CXCL12 in both diabetic and wild type mice, 2) create a constitutively expressed CXCL12 plasmid, 3) determine the influence of CXCL12 on the rate of diabetic wound healing, 4) quantitate increased stem cell recruitment. METHODS: We performed RT PCR analysis of CXCL12 mRNA in skin from Lepr db⫺/⫺ diabetic and wild-type mice on days 0,2,4,7,and 45 after wounding. Transgene expression of CXCL12 was introduced into wounds by a CMV-driven expression plasmid. CXCL12 or sham plasmids were applied to the wounds of diabetic mice. Wound areas were measured every five days using planimetry imaging. FACS analysis was performed on peripheral blood of treated mice at Days 1,4,7,and 10 post wounding. RESULTS: CXCL12 mRNA was significantly reduced in diabetic mice 7 days after wounding (P⬍ 0.02). The CXCL12 expression plasmid restored the rate of wound closure to near that of control mice (closed by 23 days). An increase in circulating stem cells of more than 3% can be seen as early as Day 1 after wounding with addition of our plasmid. CONCLUSIONS: Increasing the level of CXCL12 in diabetic wounds accelerates healing to a near normal rate via stem cell recruitment. These results suggest a significant therapeutic potential in the treatment of chronic, diabetic wounds.
pair, suggesting that Wnt signaling may play a role in fetal scaring. Our continuing studies will focus on disrupting the Wnt pathway post-wounding and delineating which Wnt proteins are up-regulated after injury.
Modulation of cutaneous scarring in a liquid environment in the Yorkshire pig Richard G Reish BS, Baraa Zuhaili MD, Emily C Waisbren BS, Juri Bergmann MD, Pejman Aflaki MD, Taro Koyama MD, PhD, Feng Yao PhD, Elof Eriksson MD, PhD, FACS Brigham and Women’s Hospital, Division of Plastic Surgery, Boston, MA INTRODUCTION: There have been limited animal models of scarring. It was hypothesized that decreased inflammatory response seen in wet wound healing is correlated with diminished scarring. This study seeks to test this hypothesis and to validate a model of scarring in the liquid environment in the Yorkshire pig. METHODS: Three Yorkshire pigs were used to create 36 dorsal wounds per pig (108 wounds total) in the following groups: full thickness excisional, partial thickness, meshed STSG, sheet STSG, minced skin, and incisional wounds. Wounds were randomized into wet and dry groups. Wet wounds were enclosed in polyurethane chambers with 2 ml of normal saline. Dry wounds were covered with regular gauze. All wounds were converted to dry healing after two weeks. On day 28, terminal biopsies were performed. RESULTS: The mean macroscopic scar surface area was significantly decreased in full thickness excisional wet wounds compared to dry wounds (61.2 mm2 vs 150.8 mm2, p⬍0.01). H&E and trichrome histology demonstrated significantly less inflammatory infiltrate, thicker neoepidermis, more pronounced rete ridge formation, and less scar tissue thickness in wet wounds. Hydroxyproline content was decreased in full thickness wet compared to dry groups (44.81mg/g vs 62.21mg/g, p⬍0.01). Tensile strength was 90% greater in all full thickness wet compared to dry groups (p⬍0.01). CONCLUSIONS: Healing in the liquid environment significantly reduced macroscopic scar surface area, histological evidence of scar, hydroxyproline content, and increased the wound tensile strength. This model will allow for future investigation of high- dose topical scar modulating agents in the liquid environment.
A novel relational database for clinical outcomes in patients with diabetic foot ulcers: The wound electronic medical record (WEMR) Michael Samuel Golinko MD, MA, Eashwar Chandrasekaran MS, Dalton Cox BA, Stephan Barrientos MD, Sasa Vukelic, Harold Brem MD, FACS Columbia University Medical Center, New York, NY INTRODUCTION: Diabetic foot ulcers (DFUs) occur in up to 25% of patients with diabetes, and of these, up to 24 % of ulcers will end in amputation. Our hypothesis is that clinical outcomes of a university based clinical practice can be measured by capturing clinically relevant data using a relational database.
Surgical Forum Abstracts
S61
METHODS: The three year experience of a single university based wound center 146 patients with 170 target diabetic foot ulcers were evaluated. At baseline and at each subsequent visit, all clinical information including laboratory values and wound area were entered into a custom-designed relational database known as the wound electronic medical record (WEMR); amputation was the primary outcomes measure. RESULTS: 19 (12.9%) patients underwent an amputation. A total of 32 amputations were performed in 23 limbs (9 major, 23 minor). Characteristics such as age, sex, HbA1c%, cholesterol, white blood cell count, initial wound area, follow-up time were not significantly different between the amputees and non-amputees (p⬎0.05). Baseline albumin was significantly lower in the amputee group, (3.5 ⫾0.6 vs. 3.9 ⫾1.1 mg/dl, p⫻0.02) Non-amputated patients had significantly more visits to the clinic (p⫻0.02). Wound Characteristics # WEMR records amputation free visits)
Amputees (nⴛ23) 4.6 ⫾ 3.6, 3.0
Non-amputees Significance (nⴛ147) (pⴛ) 6.7 ⫾ 6.3, 4
0.023
Initial area (cm )
15.2 ⫾ 22.3, 5.4
6.8 ⫾ 9.1, 3.1
0.084
Area at 4 weeks (cm2)
17.8 ⫾ 23.4, 5.9
6.7 ⫾ 9.6, 2.7
0.064
2
Area at last visit (cm2)
18.2 ⫾ 25.9, 5.6
4.8 ⫾ 8.3, 1.1
0.020
Mean treatment time or time to amputation (days)
93.4 ⫾ 110.6, 53
131.4 ⫾ 168, 66
0.167
CONCLUSIONS: At a single center, lower albumin, larger wound area, and fewer visits to the wound center may be associated with subsequent amputation. This study demonstrates that outcomes data can be reported using a wound electronic medical record and may be used track amputations. Future study is needed to determine how such a system can be used to alert the clinician to a non-healing wound in order to prevent amputations.
A novel murine model of isolated skin radiation injury Phuong D Nguyen MD, Richard A Zoumalan MD, Christopher C Chang BA, Robert J Allen, Jr. MD, Alexander M Sailon BA, Stephen M Warren MD, FACS, Jamie P Levine MD, FACS, Pierre B Saadeh MD New York University School of Medicine, New York, NY INTRODUCTION: Radiation (XRT), an indispensable modality in the treatment of head and neck cancer, is associated with unavoidable sequelae, including skin fibrosis, which pose a challenge for the ablative and reconstructive surgeon. We present a novel murine model of isolated skin radiation injury, a prerequisite to the development of ameliorative interventions. METHODS: The dorsal skin of adult wild-type FVB mice was isolated with a low-pressure, non-ischemic clamp (rest of mouse was lead-shielded) and exposed to one dose of 30, 45, or 55Gy. XRT monitors measured scatter. Skin changes were assessed postirradiation by Doppler ultrasonography, gross evaluation, hematoxylin & eosin (H&E), Sirius red staining, and immunohistochemistry for SMAD3 weekly for 12 weeks. Peripheral blood smears were also performed. Controls were not irradiated.
S62
Surgical Forum Abstracts
RESULTS: All mice tolerated irradiation, with negligible XRT scatter. At 45 and 55Gy, skin was visibly erythematous and thickened by one week, while ulceration variably occurred by two weeks. Doppler ultrasonography demonstrated decreased (approximately 50%) dorsal skin perfusion by two weeks. H&E revealed increased dermal thickness and fibroblastic proliferation. Sirius red staining confirmed increased collagen deposition. SMAD3 levels were increased by two weeks and remained elevated thereafter. The 30Gy group yielded results similar to non-irradiated controls. Peripheral blood smears did not suggest bone marrow abnormality. CONCLUSIONS: This novel murine model of XRT injury is the first to isolate injury to the skin allowing delivery of doses otherwise lethal to mice. We found 45Gy was the minimal dose resulting in unambiguous and consistent injury. Moreover, the injuries sustained were analogous to human XRT injuries grossly and histologically.
Application of the engineered CXCL12 plasmid to diabetic mouse wounds accelerates healing to near normal via stem cell trafficking Terry Restivo DO, MA, Kimberly Mace PhD, Alden H Harken MD, FACS, David M Young MD, FACS UCSF-Surgical Laboratory, San Rafael, CA INTRODUCTION: The chemokine CXCL12 influences survival, production and trafficking of stem cells. We hypothesize that by
J Am Coll Surg
increasing the level of CXCL12 in the diabetic wound, we would accelerate time to wound closure. This series of experiments aims to: 1) assess the post-wounding expression of the chemokine CXCL12 in both diabetic and wild type mice, 2) create a constitutively expressed CXCL12 plasmid, 3) determine the influence of CXCL12 on the rate of diabetic wound healing, 4) quantitate increased stem cell recruitment. METHODS: We performed RT PCR analysis of CXCL12 mRNA in skin from Lepr db⫺/⫺ diabetic and wild-type mice on days 0,2,4,7,and 45 after wounding. Transgene expression of CXCL12 was introduced into wounds by a CMV-driven expression plasmid. CXCL12 or sham plasmids were applied to the wounds of diabetic mice. Wound areas were measured every five days using planimetry imaging. FACS analysis was performed on peripheral blood of treated mice at Days 1,4,7,and 10 post wounding. RESULTS: CXCL12 mRNA was significantly reduced in diabetic mice 7 days after wounding (P⬍ 0.02). The CXCL12 expression plasmid restored the rate of wound closure to near that of control mice (closed by 23 days). An increase in circulating stem cells of more than 3% can be seen as early as Day 1 after wounding with addition of our plasmid. CONCLUSIONS: Increasing the level of CXCL12 in diabetic wounds accelerates healing to a near normal rate via stem cell recruitment. These results suggest a significant therapeutic potential in the treatment of chronic, diabetic wounds.