Apoptotic death in deep partial thickness burns vs. normal skin of burned patients

BACKGROUND: Deep partial thickness burns have an ambiguous behavior evolving either into spontaneous healing or full thickness burns. The aim of this study was to investigate these lesions for the presence of apoptosis thereby giving a possible cellular explanation to their peculiar clinical progression. METHODS: We used colocalization of DNA fragments (terminal deoxynucleotidyl transferase mediated dUTP nick end labeling) and Fas ligand CD95 antibodies to calculate the apoptotic rate of deep partial thickness burns and normal skin in 21 patients after acute thermal injuries (significant difference considered: P < 0.05). RESULTS: Deep partial thickness burns were associated with a higher apoptotic rate than normal skin (48.15% +/- 17.22% versus 18.6% +/- 7.2%; P = 0.0002). There were no apparent significant correlations of apoptotic rate with age, days from injury, total burn surface area or deep burn area except for a slight correlation with sex (r = 0.484; P = 0.02). CONCLUSIONS: A higher apoptotic rate was present in dermal cells of deep partial thickness burns if compared to that of the unburned skin. These data would suggest that deep partial thickness progression derive from apoptosis. Specific studies are required to confirm this hypothesis and to investigate its clinical and therapeutic significance.     

深Ⅱ度烧伤创面治疗与愈合后的关系

深Ⅱ度烧伤为皮肤真皮深层的损伤,由于人体各部位真皮厚度不一,烧伤程度不一,故深Ⅱ度烧伤的临床变数较大。浅的接近浅Ⅱ度,深的则临界Ⅲ度。深Ⅱ度创面有真皮残留,网织层内存有毛囊、汗腺和皮脂腺,这些皮肤附件的上皮增殖可形成修复创面的上皮岛,虽然不需植皮创面也能自行愈合     

异种(猪)脱细胞真皮基质一次性包扎治疗深Ⅱ度烧伤

目的探讨应用异种(猪)脱细胞真皮基质一次性包扎治疗深Ⅱ度烧伤创面的临床应用效果。方法1997年1月—2004年1月,应用异种(猪)脱细胞真皮基质一次包扎治疗50%~95%总体表面积(TBSA)、深Ⅱ度烧伤的患者67例[异种(猪)脱细胞真皮基质治疗组];同期保痂治疗的50%~95%TBSA、深Ⅱ度的患者10例(保痂治疗组),观察创面愈合时间和愈合质量及其并发症发生情况。治愈患者经过3个月~2年的随诊,观察瘢痕增生情况。结果异种(猪)脱细胞真皮基质治疗组深Ⅱ度创面中途基本不需换药,创面愈合时间缩短,平均(12.2±2.6)d,而保痂治疗组愈合时间为(27.4±3.5)d,差异具有统计学意义(P<0.05);同时,异种(猪)脱细胞真皮基质治疗组瘢痕增生情况较保痂治疗组明显减轻或者无瘢痕增生。结论一次性覆盖异种(猪)脱细胞真皮基质可有效地治疗深Ⅱ度烧伤创面,能加快创面愈合,减轻瘢痕增生,从而降低烧伤感染和炎症反应综合征的发生。     

大鼠深Ⅱ度烫伤后创面愈合过程中纤溶变化的意义

为探讨烧伤深Ⅱ度创面早期加深及其愈合与纤溶功能变化的关系,观察了深Ⅱ度烫伤大鼠伤后10天内创面组织学和纤溶反应的变化。Masson 胶原染色显示创面在伤后72小时内逐步加深,伤后10天见新生结缔组织和创缘表皮增殖匍行。对血浆和创面活检组织24小时浸出液中纤溶指标的测试表明伤后2小时创面纤溶反应激活,但在伤后24小时已呈抑制状态,并持续至伤后10天。纤溶指标动态变化和相关性分析提示纤溶抑制因素可能来自伤后早期活性即已显著增强的创面纤溶酶原激活抑制物,伤后24小时起活性显著增强的α_2抗纤溶酶,以及伤后72小时活性显著增强的抗凝血酶Ⅲ。观察结果提示烫伤后纤溶功能抑制可使创面局部的纤维蛋白不致溶解,从而成为深Ⅱ度创面早期加深的一个重要因素,也可能是创面愈合调控中的一个重要环节。     

大鼠深Ⅱ度烫伤后创面愈合过程中纤溶变化的意义

为探讨烧伤深Ⅱ度创面早期加深及其愈合与纤溶功能变化的关系，观察了深Ⅱ度烫伤大鼠伤后１０天内创面组织学和纤溶反应的变化。Ｍａｓｓｏｎ胶原染色显示创面在伤后７２小时内逐步加深，伤后１０天见新生结缔组织和创缘表皮增殖匍行。对血浆和创面活检组织２４小时浸出液中纤溶指标的测试表明伤后２小时创面纤溶反应激活，但在伤后２４小时已呈抑制状态，并持续至伤后１０天。纤溶指标动态变化和相关性分析提示纤溶抑制因素可能来自伤后早期活性即已显著增强的创面纤溶酶原激活抑制物，伤后２４小时起活性显著增强的α２抗纤溶酶，以及伤后７２小时活性显著增强的抗凝血酶Ⅲ。观察结果提示烫伤后纤溶功能抑制可使创面局部的纤维蛋白不致溶解，从而成为深Ⅱ度创面早期加深的一个重要因素，也可能是创面愈合调控中的一个重要环节     

HydroColloid dressing (Duoderm) for the treatment of superficial and deep partial thickness burns

HydroColloid Dressing (Duoderm, HCD) is a new kind of dressing, based on the fact that occlusion can provide an optimum wound environment for quick re-epithelialization. Seventy patients with superficial and deep partial thickness burns of up to 7% TBSA were treated with HCD. In 16 patients a second burned area, similar in size and depth of the burn treated with HCD, was treated with human allografts or silversulfadiazine (SSD). Five patients with very small full thickness burns were also treated with HCD. In three patients (4.5%) the treatment with HCD had to be discontinued before total re-epithelialization had occurred, for various reasons. Statistically, HCD provided faster re-epithelialization than allografts or SSD. The cosmetic and functional results were excellent. After six months only one patient was found to have a small area of hypertrophy. In this study HCD was found to be a very good dressing for the treatment of smaller partial thickness burns.     

大鼠深Ⅱ度烫伤后创面愈合过程中纤溶变化的意义

为探讨烧伤深Ⅱ度创面早期加深及其愈合与纤溶功能变化的关系，观察了深Ⅱ度烫伤大鼠伤后１０天内创面组织学和纤溶反应的变化。Ｍａｓｓｏｎ胶原染色显示创面在伤后７２小时内逐步加深，伤后１０天见新生结缔组织和创缘表皮增殖匍行。对血浆和创面活检组织２４小时浸出液中纤溶指标的测试表明伤后２小时创面纤溶反应激活，但在伤后２４小时已呈抑制状态，并持续至伤后１０天，纤溶指标动态变化和相关性分析提示纤溶抑制因素可能来自     

Use of Suprathel for partial thickness burns in children

We evaluated the use of Suprathel^®, a synthetic skin substitute, for partial thickness burns in children. Thirty-three children (20 females, 13 males; mean age 29 months, range 5 months to 11 years) with burns were treated with Suprathel^®. The burns were superficial partial thickness (n = 24) or mid-dermal (n = 19); the median %TBSA was 4% (range 1–13%).     

透明质酸刺激因子对深Ⅱ度烧伤创面瘢痕形成的影响

从兔羊水及胎兔血清中提取透明质酸刺激因子（ＨＡＳＦ）液。将其用于深Ⅱ度烧伤创面，采用自身对照法，通过观测早期创面渗液中透明质酸（ＨＡ）含量变化、愈合后一个月局部组织的外观及镜下观和组织中胶原含量的分析，从中探讨了ＨＡＳＦ在深Ⅱ度烧伤创面愈合过程中对瘢痕形成的影响。此外还将ＨＡＳＦ用于体外培养的兔成纤维细胞，观测上清液中ＨＡ含量的改变。结果表明，ＨＡＳＦ可以明显提高创面渗液中ＨＡ的含量，体外实验也证实ＨＡＳＦ有促成纤维细胞产生ＨＡ的作用，而ＨＡ具有调节胶原合成的作用，可提高Ⅲ型胶原的比率，使胶原纤维变细，从而减轻瘢痕的产生。此外发现，在瘢痕组织中，Ⅰ、Ⅲ型胶原总量和正常皮肤间差异无显著意义（Ｐ＞０．０５）。     

Comparison of non-surgical methods for the treatment of deep partial thickness skin burns of the hand

This paper describes a randomized, controlled, parallel-group, single-center clinical trial designed to compare non surgical treatment methods of deep partial thickness skin burns of the hand.All patients were scanned with the Laser Doppler Imaging device to determine the depth of the burn wound. Viable keratinocytes sites were determined according to the established Perfusion Units (PU) measurement system. The trial enrolled 87 patients with hand burn wounds in the section of 260–600 PU.Hand burn patients were divided into the following four groups: treated with hydrocolloid dressings; treated with mechanical debridement of monofilament polyester fibers pad and then applying silver sulfadiazine; treated with gauze dressings containing enzymatic collagenase preparation. The fourth group of patients was treated with silver sulfadiazine and gauze dressings. This group was considered as the control group. The wound healing status was assessed after 3, 7, 14 and 21 days. Burn scars and injured extremity function were assessed after six months according to the Vancouver Scar Scale and Disabilities of the Arm, Shoulder and Hand Outcome Measure.The fastest epithelialization of hand burn wounds was observed in the patients group treated with hydrocolloid dressings (15, 7 days, p < 0,05). The patients of this group also had less scars and a better hand function.     

Skin substitutes in the treatment of deep partial skin thickness burns in children: clinical experience and long-term results

This report describes the use of skin substitutes in the treatment of deep partial skin thickness burns in childhood. These are lesions that, if treated inadequately, can result in severe scarring. However, if treated appropriately, they can heal without any sequelae, which is obviously crucial for aesthetic and psychological reasons. This review contains children admitted to the authors' Burn Unit over a 5-year period (1984-88) with deep partial skin thickness lesions which were treated with synthetic and/or biosynthetic skin substitutes and without surgical procedures. This group of children has been compared with another group hospitalized for burns of the same depth and treated with conventional closed wound management. First, short-term results are presented, highlighting healing time, followed by the long-term results from an aesthetic and functional viewpoint.     

Inverse relationship between the apoptotic rate and the time elapsed from thermal injuries in deep partial thickness burns

BACKGROUND: The purpose of this article was to further describe apoptotic behaviour in deep partial thickness burns, correlating the apoptotic rate of these lesions with the time elapsed from injury. METHODS: We used TUNEL and Fas immunohistochemistry in serial biopsies of deep partial thickness burns harvested from 1 to 23 days following injury. The apoptotic rate was defined as the number of apoptotic cells out of the total number of nucleated cells. RESULTS: We recruited 25 subjects. Apoptosis was present in all biopsies and showed an inverse relationship with the time elapsed from thermal injury, higher during the first days and lower in the third week (r=-0.518; p=0.008). No significant correlations were demonstrated with age, total burn surface area, deep partial thickness burns area, Baux UBS index. CONCLUSIONS: Our study demonstrates that apoptosis persists in deep partial thickness burns throughout the first 3 weeks and shows an inverse relationship with the time elapsed from injury. It provides, in our opinion, the basis for future investigations regarding correlation with local vascularity and perfusion status and with clinical outcomes of deep partial thickness burns.     

Apoptotic versus necrotic characteristics of retinal ganglion cell death after partial optic nerve injury

We have investigated time course and characteristics of retinal ganglion cell (RGC) death after partial optic nerve injury. In situ end labeling of DNA fragments with the terminal deoxynucleotidyl transferase (TdT)-mediated deoxyuridine (dUTP)-biotin nick end labeling (TUNEL) method revealed the presence of apoptotic cells on as early as 5 days postcrush with a very high number of TUNEL-positive cells 1 week postinjury. At the ultrastructural level, features of apoptosis were clearly present in the ganglion cell layer at this time point. Moreover, TUNEL-positive cells could be identified as retinal ganglion cells by retrograde labeling with fluorogold. In addition, DNA laddering characteristic for apoptosis was found 1 week postinjury. A considerable number of TUNEL-labeled cells was still found after 2 weeks postinjury. Retinal whole mounts prepared at postlesion days 2-5, however, revealed that many cell bodies with ruptured membranes as evidenced by nucleosomal Sytox staining were present. These cells were also identified as retinal ganglion cells by retrograde labeling with fluorogold. Moreover, at this early stages of RGC degeneration necrotic cellular profiles could be detected by electron microscopic analysis. Thus, evidence is provided that necrosis and apoptosis follow a distinctly different time course after partial optic nerve injury.     

Porcine dermal collagen as a wound dressing for skin donor sites and deep partial skin thickness burns

Collagen was extracted by pepsin digestion from porcine skin, and collagen membrane was prepared by salt precipitation. The porcine collagen membrane was evaluated as a burn wound dressing in deep partial skin thickness burn wounds in rats. Burn wounds, 4 × 4 cm, were inflicted by exposure of skin to 75°C for 15 s followed by de-epithelialization. Wound healing was assessed by planimetry of epithelialization on day 10 after injury. Open wounds exhibited 24 per cent of wound area re-epithelialized. Collagen membrane dressing significantly improved the healing to 69 per cent of wound area (P < 0.0001). In a completely separate experiment, the porcine collagen membrane was applied as a wound dressing to the donor sites of burn patients, and its effect on wound healing was compared with that of a petroleum jelly gauze dressing. The donor sites covered with petroleum jelly gauze had re-epithelialized by an average of 14.5 days (ranging from 13 to 16 days) after wounding. The wounds dressed with collagen membrane demonstrated a significant increase in the healing rate. Complete re-epithelialization was observed by 10.3 days (ranging from 10 to 12 days) after wounding (P < 0.0001).     

Apoptotic neuronal death following deep hypothermic circulatory arrest in piglets

BACKGROUND: Deep hypothermic circulatory arrest (DHCA), as used in infant heart surgery, carries a risk of brain injury. In a piglet DHCA model, neocortical neurons appear to undergo apoptotic death. Caspases, cytochrome c, tumor necrosis factor (TNF), and Fas play a role in apoptosis in many ischemic models. This study examined the expression of these factors in a DHCA piglet model. METHODS: Thirty-nine anesthetized piglets were studied. After cardiopulmonary bypass (CPB) cooling of the brain temperature to 19 degrees C, DHCA was induced for 90 min, followed by CPB rewarming. After separation from CPB, piglets were killed at 1, 4, 8, 24, and 72 h and 1 week. Caspase-8 and -3 activity, and concentrations of TNF-alpha, Fas, Fas-ligand, cytochrome c, and adenosine triphosphate (ATP) were measured in the neocortex by enzymatic assay and Western blot analysis. Caspase-8 and -3 activity and cell death were examined histologically. Significance was set at P < 0.05. RESULTS: In neocortex, damaged neurons were not observed in control (no CPB), rarely observed in CPB (no DHCA), and rarely observed in the DHCA 1-h, 4-h, and 1-week reperfusion groups. However, they were seen frequently in the DHCA 8-, 24-, and 72-h reperfusion groups. Although neuronal death was widespread 8-72 h after DHCA, cortical ATP concentrations remained unchanged from control. Both caspase-3 and -8 activities were significantly increased at 8 h after DHCA, and caspase-3 concentration remained elevated for as long as 72 h. Caspase-3 and -8 activity was also observed in damaged neocortical neurons. Cytosolic cytochrome c and Fas were significantly expressed at 1 h and 4 h after DHCA, respectively. Fas-ligand and TNF-alpha were not observed in any group. CONCLUSION: After DHCA, induction of apoptosis in the neocortex occurs within a few hours of reperfusion and continues for several days. Increased Fas, cytochrome c, and caspase concentrations, coupled with normal brain ATP concentrations and apoptotic histologic appearance, are consistent with the occurrence of apoptotic cell death.