Rico P J, Johnson T E, Mitchell M A, Saladino B H, Roach W P
Department of Preventive Medicine and Biometrics, Uniformed Services University of the Health Sciences, Bethesda, MD, USA.
Comp Med. 2000 Dec;50(6):633-8.
Light amplification by stimulated emission of radiation (laser) systems operating in the so-called "eye safe" region are gaining widespread use in industry, medicine, and military applications. This research effort was geared to study the effects of laser tissue interaction on human skin by using in vivo porcine skin as an animal model. The goals of the study were to determine the median effective dose (ED50) for 1540-nm laser exposures, to evaluate the Yorkshire pig and the Yucatan mini-pig as animal models for laser exposure, and to characterize laser-induced skin lesions histologically.
A 1540-nm wavelength laser was used to expose multiple sites on the flanks of 10 pigs, using 0.8-ms pulses, ranging from 7 to 96 joules (J)/cm2. Single pulses were delivered to the flank of Yorkshire and Yucatan pigs in a grid pattern. Exposure sites were evaluated immediately after exposure and at 1 hour and 24 hours for presence of gross lesions. Representative biopsy specimens were collected from lesion sites for histologic evaluation at the 24-hour endpoint.
The ED50 for the two breeds differed in the amount of energy required to induce dermal lesions. Grossly, lesions in each breed were well demarcated and pale gray to brightly erythematous. Microscopically, lesions had epidermal layer damage as cellular swelling and nuclear pyknosis, loss of cellular detail, and coagulation necrosis at the dermal layer.
Findings suggest the presence of a different mechanism of laser-tissue damage in these two breeds. Photo-thermal mechanism appears to induce the skin lesions in the Yorkshire pig, whereas photo-thermal and photochemical mechanisms appear to be involved in lesion formation in the Yucatan mini-pig. All data obtained in this study will become part of database used by the American National Standards Institute (ANSI) to recommend laser safety standards for the occupational health and safety programs (OHSP), which will be used by industry and the military to base and update their current OHSP.
工作在所谓“人眼安全”区域的受激辐射光放大（激光）系统在工业、医学和军事应用中得到了广泛应用。本研究旨在以活体猪皮肤作为动物模型，研究激光与组织相互作用对人体皮肤的影响。该研究的目标是确定1540纳米激光照射的半数有效剂量（ED50），评估约克夏猪和尤卡坦小型猪作为激光照射动物模型的适用性，并从组织学角度对激光诱导的皮肤损伤进行特征描述。
使用波长为1540纳米的激光，以0.8毫秒的脉冲，能量范围为7至96焦耳（J）/平方厘米，照射10头猪两侧的多个部位。单脉冲以网格模式照射约克夏猪和尤卡坦猪的侧腹。照射后立即以及在1小时和24小时时评估照射部位是否存在明显损伤。在24小时的时间点，从损伤部位采集代表性活检标本进行组织学评估。
两个品种诱导皮肤损伤所需的能量不同，即ED50不同。从外观上看，每个品种的损伤界限清晰，呈浅灰色至鲜红色。在显微镜下，损伤表现为表皮层损伤，如细胞肿胀、核固缩、细胞细节丧失，以及真皮层的凝固性坏死。
研究结果表明这两个品种存在不同的激光 - 组织损伤机制。光热机制似乎在约克夏猪中诱导皮肤损伤，而光热和光化学机制似乎参与了尤卡坦小型猪的损伤形成。本研究获得的所有数据将成为美国国家标准学会（ANSI）用于推荐职业健康与安全计划（OHSP）激光安全标准的数据库的一部分，行业和军方将据此制定和更新其当前的OHSP。
