持续低热致深度烧伤的实验观察

目的：研制持续低热烧伤模型，观察基本规律并探讨其机制。方法：（1）将大鼠按不同温度及时相点随机分组，背部持续接触热源，观察创面形成过程，全层皮肤密度及病理变化，（2）将温度计置于大鼠背部皮肤筋膜下，观察不同时间和温度下，大鼠皮下温度的变化。结果：（1）随温度上升，创面形成时间明显缩短，损伤程度逐渐加重，大鼠皮肤密度的变化，在不同时间表现为不规则双曲线或三曲线。（2）稳定实验条件后，各组大鼠皮下温度的变化呈抛物线状。结论：（1）持续接触低热，皮下温度的快速增高及曲此造成的变性，坏死是导致深度烧伤的原发因素，（2）皮肤组织损伤的变化规律是热源损伤，毛细血管通透性增加，组织重量变化等多重作用的结果。     

真皮下血管网薄皮瓣血管构筑变化与成纤维细胞生长因…

为了探讨真皮下血管网薄皮瓣的成活机理，以兔为实验动物，在其背侧形成１５ｃｍ×３ｃｍ的真皮下血管网薄皮瓣，利用微循环显微镜，病理切片，组织化学染色等手段进行观察。结果表明真皮下血管网薄皮瓣术后远，中，近段血管构筑具有明显差别：近段同正常皮肤，中段为极度活跃的血管增生，远段为中度血管增长。     

耳郭软骨皮下筋膜组织复合物在鼻尖整形中的应用

目的：介绍自体耳郭软骨皮下筋膜组织复合物在鼻尖整形中的应用方法。方法：应用耳郭软骨皮下筋膜组织复合物对57例就医者实施手术。结果：术后鼻尖塑形满意，无畸形，无并发症发生。结论：应用耳郭软骨皮下筋膜组织复合物可保护鼻尖皮肤，鼻尖塑形满意，值得推广应用。     

"风筝"皮下蒂皮瓣在头颈部修复术中的应用

目的：探讨“风筝”皮下蒂皮瓣（简称皮下蒂皮瓣）在头颈部修复术中的应用。方法：对头颈部皮肤缺损者设计三角形皮下蒂皮瓣,三角形的底靠近缺损侧。于三角形两腰切开皮肤,向下外潜行分离皮下组织,然后将皮下组织蒂的中央部分用剪刀分离,形成双蒂,将皮瓣向缺损侧推进,修复组织缺损。结果：应用皮下蒂皮瓣30例,切口Ⅰ期愈合,形态较满意,切口瘢痕不明显。结论：采用皮下蒂皮瓣修复头颈部皮肤缺损,效果确定,方法简便易行。     

皮片翻转器和医用削刮修整器用于腋臭根治的临床研究

目的：探讨在腋臭根治术中如何快速清除皮下组织、顶泌汗腺和大小汗腺。方法：用皮片翻转器[1]翻转皮肤,用医用削刮修整器[2]（图1）削刮清除皮下组织、顶泌汗腺和大小汗腺。结果：用皮片翻转器翻转皮肤,用医用削刮修整器在直视下削刮清除皮下组织、顶泌汗腺和大小汗腺,皮下组织、顶泌汗腺和大小汗腺清除彻底,手术进度快。结论：皮片翻转器和医用削刮修整器是在直视下快速清除皮下组织、顶泌汗腺和大小汗腺的一套很好用的组合器械。     

化脓性汗腺炎1例

患者男，62岁。肛旁及臀部皮肤色黑质硬，破溃口反复流脓水20余年，伴排便困难1年。病理活组织检查：瘘口急慢性炎症伴上皮瘤样增生，皮下纤维组织瘤样增生。应用抗生素治疗1周。电子肠镜检查：结肠慢性炎症。彩超检查：肛门部多发脓肿并脓栓形成。专科检查：截石位见以肛门口为中心，肛周皮肤呈双手五指分开状，半径超过20cm，皮肤黑色，发黑处皮肤质硬，触之有麻木感。黑色皮肤处散在溃口20余个，且有分布不均沟壑状突起。按压左侧肛旁组织，远端溃口处有脓液流出，呈稀薄状，无异味。远端溃口及黑硬皮肤前至阴囊根部，左右两侧均距肛门13～15cm。后位距肛门约2cm。     

真皮下血管网薄皮瓣血管构筑变化与成纤维细胞生长因子的关系

为了探讨真皮下血管网薄皮瓣的成活机理，以兔为实验动物，在其背侧形成１５ｃｍ×３ｃｍ的真皮下血管网薄皮瓣，利用微循环显微镜、病理切片、组织化学染色等手段进行观察。结果表明真皮下血管网薄皮瓣术后远、中、近段血管构筑具有明显差别：近段同正常皮肤，中段为极度活跃的血管增生，远段为中度血管增生。皮瓣中段血管构筑的变化起一个“中介蒂”的作用，是皮瓣能够早期断蒂及超过传统长宽比例可以成活的基础。成纤维细胞生长因子是促使皮瓣血管构筑变化的重要因素之一。     

下腹部多个真皮下血管网皮瓣在手外伤修复中的应用

目的：应用下腹部多个真皮下血管网皮瓣修复手外伤，方法：在下腹形成以旋髂浅血管为蒂的髂腰部皮瓣及以腹壁浅血管为蒂的下腹部皮瓣，二皮瓣共蒂形成双叶皮瓣，同时将其修薄，形成有轴心血管的真皮下血管网皮瓣，修复两指完全脱套伤。在下腹部形成多个真皮下血管网的任意皮瓣，修复多个指背皮肤缺损伴有肌腱及骨外露的创面。供区如不能直接拉拢缝合，可取断层皮片修复供区创面.结果：本组10例中，8例采用下腹部双叶真皮下血管网轴型皮瓣修复，2例采用下腹部真皮下血管网任意皮瓣修复，术后效果。结论：采用多个真皮下血管网皮瓣修复手外伤的创面，伤指不需并指，去脂，分指，术后外形佳，是目前较理想的修复手外伤的手术方法。     

真皮下血管网皮瓣修复感染创面的研究

目的：探讨真皮下血管网皮瓣的抗菌能力和临床修复感染创面的应用。方法：以家猪为实验动物，在臀部两侧分别形成传统的岛状皮瓣和真皮下血管网岛状皮瓣，用细菌计数、吖啶橙荧光染色测定白细胞吞噬指数和白细胞内杀菌率等方法，进行对比。结果：真皮下血管网岛状皮瓣的抗菌力明显降低。 １９８９年起临床应用 ５例，创面彻底清创后用吻合血管的真皮下血管网游离皮瓣修复，全部成活。结论：该皮瓣抗菌力虽低于传统皮瓣，但仍可用于修复感染创面。     

小切口摘除大汗腺治疗腋臭

目的：皮肤切除、真皮下组织修剪等治疗腋臭的手术，常造成腋部瘢痕、皮肤坏死等情况，本文应用小切口大汗腺单纯摘除方法，希望探讨一种损伤小且效果好的腋臭治疗手术。方法：对21位18～24岁女性腋臭患者，采用摘除大汗腺的手术方法治疗。行平行腋窝皱襞小切口入路，分离全腋区皮下浅层，直视下逐个挑剪去除大汗腺腺体，保留真皮下血管网。术后七天拆线。结果：术后经6～18个月随访，所有患者腋区皮肤无坏死，切口隐蔽，瘢痕不明显，腋臭味明显减轻。病理切片示所摘取组织为典型的大汗腺组织。结论：大汗腺可以被准确识别，单纯摘除的手术方法是一种损伤小的腋臭治疗方法。     

大鼠穿支蒂皮瓣的实验研究

目的建立穿支血管蒂皮瓣的动物实验模型，探讨蒂部穿支血管对皮瓣血供的影响。方法选择30只雄雌不限SD大鼠，分成1个实验组和2个对照组，每组10只，实验组为穿支血管蒂皮瓣组，对照1组为皮下蒂皮瓣组，对照2组为随意皮肤蒂皮瓣组，实验组进行血管造影及组织学检查。结果大鼠腹部皮肤穿支血管起源于腹壁上动脉深支，于腹直肌鞘两侧穿出，共8～10支，穿支垂直间距0．4-1．0cm，以左上第2穿支外径粗大，一条肌皮穿支血管可供养大鼠腹部皮肤81．5％。结论穿支血管蒂皮瓣血供来源于穿支血管，切取穿支血管蒂皮瓣面积比随意皮肤蒂皮瓣面积大，并可提供多种皮瓣设计的选择。     

Hand rejuvenation

Both skin and subcutaneous tissues are targeted in this multistage hand rejuvenation protocol. Topical therapies and intense pulsed light are used for skin thickening, rejuvenation, and improvement of age spots and leathery texture. Autologous fat is injected into multiple tissue layers to fill out underlying tissue. Excess skin is excised with a small, well-hidden incision on the ulnar surface.     

Influence of external forces (pressure and shear force) on superficial layer and subcutis of porcine skin and effects of dressing materials: Are dressing materials beneficial for reducing pressure and shear force in tissues?

The purpose of this study was to measure the impact of external shear force and pressure on a superficial layer of skin and subcutaneous layer with an underlying bony prominence, and also to verify how the influence of these external forces can be reduced after dressings are applied. For this purpose, an experimental model was prepared, consisting of porcine skin and a Predia sensor capable of measuring pressure and shear force simultaneously. External force was applied to the skin model using a 1 kg weight consisting of metal beads. As a result, the control of the shear force value in the subcutaneous layer became approximately 35% smaller than the control in the superficial layer. The shear forces present in the subcutaneous layer were significantly reduced to within 31–45% when compared with the control values, depending on the dressing applied. Regarding the maximum pressures in the subcutaneous layer, the pressure measured following movement was 2.4 times higher in the control than the static pressure and they were also 1.3–1.8 times higher than the static pressure in all instances with the dressing tested. All the dressing materials tested proved to be effective in reducing pressure in the subcutaneous layer compared with the control. Film dressings and hydrocolloid dressings were more effective than hydropolymer and hydrocellular dressings. From the above results, we conclude that efforts made to reduce shear force and pressure may be clinically important.     

Merkel Cell Carcinoma Arising from the Subcutaneous Fat of the Arm with Intact Skin

BACKGROUND: Merkel cell carcinoma is a rare malignant neuroendocrine neoplasm characteristically arising from the dermis of sunlight-exposed skin. It rarely arises outside the skin. OBJECTIVE: We present a patient with primary Merkel cell carcinoma arising from subcutaneous fat, with no involvement of the overlying skin. We describe the clinical manifestations and magnetic resonance imaging (MRI) findings. METHODS: We report a 63-year-old woman with a primary lesion of Merkel cell carcinoma that arose from the subcutaneous fat layer of the left arm. The lesion presented as a subcutaneous nodule with intact overlying skin. MRI showed that the nodular lesion was located entirely in the subcutaneous fat layer, with no involvement of the dermis. Peritumoral infiltration around the lesion and enlarged lymph nodes deep to the lesion were noted. The patient received wide excision of the lesion with dissection of the regional lymph nodes and adjuvant radiotherapy and chemotherapy. RESULTS: Histopathologic examination confirmed the diagnosis of Merkel cell carcinoma with local lymphatic metastasis, and the lesion was completely located in the subcutaneous fat, with no involvement of the dermis. These findings were well correlated with MRI findings. CONCLUSION: Primary Merkel cell carcinoma may arise from the subcutaneous fat and present as an entirely subcutaneous lesion with intact skin. MRI is helpful to evaluate the local extension of the lesion and regional lymphatic metastasis.     

Ulnar versus radial forearm flap in head and neck reconstruction: an experimental and clinical study.

BACKGROUND: To consider the pros and cons of the microvascular ulnar forearm flap compared with its radial counterpart, this study compares the use of these two flaps for head and neck reconstruction. METHODS: In 75 patients, 51 ulnar and 24 radial forearm flaps were used. Both groups were compared regarding flap dissection, suitability of the flap for the recipient region, complication rate, and secondary morbidity in the donor region. Furthermore, in 40 healthy volunteers, the thickness of the subcutaneous tissue layer was measured by use of ultrasonography. RESULTS: Flap survival rate, respectively wound healing, in the recipient region showed no differences. Clinical and experimental results demonstrated a thinner subcutaneous layer in the ulnar aspect of the forearm. Compared with its radial equivalent, closure of the ulnar donor side by skin grafting resulted in a significantly lower complication rate. CONCLUSIONS: The ulnar forearm flap is favored because of the less hairy skin of the ulnar forearm region, the thinner layer of subcutaneous tissues, and the more conveniently located donor area. The ulnar forearm pedicle is long compared with alternative transplants but shorter than the radial equivalent.     

Vascular endothelial growth factor gene therapy in improvement of skin paddle survival in a rat TRAM flap model

The use of growth factors in inducing angiogenesis and enhancing flap viability has provided promising results. Targeted gene therapy has evolved in hopes of increasing the longevity and effectiveness of these growth factor treatments. The purpose of this study was to examine the effect of preoperative treatment by vascular endothelial growth factor (VEGF) plasmid DNA on the survival of the skin paddle in a rat pedicled TRAM flap model. In part one of the study, VEGF plasmid DNA incorporated with lipofectamine was injected into the subcutaneous fascial layer of the upper abdominal walls of the rats. At 4 days postoperatively, biopsies were taken from the injected area for histology and VEGF protein quantification. In part two of the study, the rats were divided into three groups. In one experimental group, the VEGF plasmid DNA was injected into the subcutaneous fascial layer in the area where the TRAM flap would be elevated. In two control groups, the plasmid without VEGF DNA and saline were injected. The flaps were raised and replaced 4 days after injection. Flap survival was examined. Results showed that tissue receiving VEGF plasmid DNA injection revealed new vessel sprouting. The VEGF levels in these tissues were significantly higher than in the tissue not receiving VEGF plasmid DNA. In flap survival, the mean viable area of the skin paddles receiving preoperative VEGF plasmid DNA injection was significantly larger than that of flaps receiving no VEGF plasmid DNA and saline injection. This study demonstrated that preoperative subcutaneous injection of VEGF plasmid DNA could induce angiogenesis and improve TRAM skin paddle survival.     

Use of organotypic coculture to study keloid biology

BACKGROUND: Keloids are pathologic scars afflicting a large segment of our population and for which there is no definitive therapy. The lack of an animal model for keloid formation has hampered study. We developed an in vitro organotypic skin model to simulate normal keloid biology, which may allow us to study keloid formation without an animal model. METHODS: Normal (NFs) and keloid (KFs) human fibroblasts were cultured in a collagen matrix to create a 3-dimensional dermal structure. Normal human keratinocytes (NKs) were cultured as a second layer on top and exposed to an air-fluid interface to allow differentiation into a mature keratinocyte layer. The organotypic skin was maintained for 28 days in Dulbecco's modified eagle medium with 10% fetal calf serum. Samples were collected, processed, sectioned, stained with hematoxylin and eosin, and then measured for qualitative analysis. alpha-smooth-muscle actin was also evaluated by immunoblotting. RESULTS: KF/NK organotypic skin showed increased collagen deposition, based on significantly denser collagen staining, with increased dermal thickness compared with NF/NK organotypic skin. We saw increased contracture in the KF/NK construct, and this correlated with increased organization of alpha-smooth-muscle actin fibers in the dermal layer of KF/NK organotypic skin compared with NF/NK skin. CONCLUSIONS: We have shown that coculture of KFs with keloid keratinocytes leads to an increased collagen production and dermal contracture compared with NFs and NKs, consistent with known keloid behavior. Given the lack of an animal model, we believe that organotypic skin culture can serve as a surrogate to study keloid formation.     

血管内皮生长因子促进跨区供血反流轴型皮瓣成活的实验研究

目的研究血管内皮生长因子（vascular endothelial growth factor，VEGF）的局部皮下注射对大鼠背部跨区供血反流轴型皮瓣成活的影响及效果。方法取20只SD大鼠，制备8cm×2cm大鼠背部跨区供血反流轴型皮瓣模型，随机分成两组，每组10只。实验组：于皮瓣远端7．5cm及6．5cm处共选择4个对称位点，分别予100ng／100μlVEGF溶液50μl；对照组：每一位点予生理盐水50μl。术后1～7d行皮瓣大体观察，并于7d处死大鼠，切取皮瓣，行皮瓣成活率测定、组织学观察及血管密度检测。结果大体观察，实验组皮瓣成活面积明显大于对照组，实验组皮瓣成活面积15．55±0．27cm^2，对照组13．42±0．57cm^2，差异有统计学意义（P〈0.01）。组织学观察，实验组皮瓣血管密度34．40±3．75个／10倍光镜下视野，对照组21．00±3．16个／10倍光镜下视野，差异有统计学意义（P〈0.01）。镜下见实验组有大量新生肉芽组织形成，胶原纤维排列规则，成纤维细胞较多，炎性细胞浸润程度轻；对照组新生肉芽组织少，胶原纤维凝集成块，成纤维细胞少，炎性细胞浸润程度重。结论VEGF在皮瓣成活早期，通过促进缺血皮瓣新生血管形成，增加血管数量，改善缺血组织的血液供应，促进皮瓣成活；在皮瓣形成时局部、单次、足量应用VEGF是促进跨区供血反流轴型皮瓣远端成活的有效方法。     

MC148基因局部转染延长大鼠异体皮肤移植成活时间的研究

目的探讨MC148基因局部转染对皮肤移植排斥反应的免疫抑制作用。方法从传染性软疣病毒(MCV)中克隆MC148基因,构建Ad-MC148腺病毒重组体后,用其转染8只Lewis大鼠(供体)尾皮局部。另选16只Wistar大鼠(受体),于尾部制作皮肤缺损创面后,分为对照组8只, 移植未转染的供体尾皮;转染组8只,移植转染了MC148基因的供体尾皮。于术后6 h及2、3、7、10 d,检测MC148 mRNA在转染组大鼠皮肤组织内的表达情况,以它与内参照β肌动蛋白之间的吸光度 (A)之比表示;比较两组大鼠移植皮肤的成活时间;术后7 d起对两组部分大鼠行大体观察,其余大鼠于术后7 d行组织病理学观察。结果术后6 h转染组大鼠皮肤组织内有MC148 mRNA表达, 第3天达到高峰(A MC148 mRNA/Aβ肌动蛋白=0．86),随后下降,但可持续表达约10 d。对照组大鼠移植皮肤成活时间为(8．5±3．4)d,明显低于转染组(15．0±2．0)d(P<0．01)。大体及组织病理学观察到, 术后7 d转染组大鼠尾皮色泽红润,皮下组织内有少量炎性细胞浸润,12-20 d后移植皮肤才逐渐变黑、脱落;术后7 d对照组大鼠尾皮色泽变黑、逐渐脱落,真皮及皮下组织有大量炎性细胞浸润。结论 MC148基因局部转染可能通过抑制器官移植后白细胞浸润而发挥免疫抑制作用。     

术中即时扩张皮肤面积增加与压力和时间的量效关系

目的探讨术中即时扩张皮肤面积增加与压力、时间的量效关系。方法用6头小型猪，压力参数分别为15、20、25kPa，时间参数为60、90min，配对组成6个实验组，1个对照组，36个实验部位。在每只猪背部皮下均匀埋置100ml圆形扩张器6个，术中即时扩张皮肤，观察扩张皮肤各径线移位特点，计算面积变化。结果扩张区周边皮肤向中心蠕动和扩张器表面皮肤伸展同时存在。扩张皮肤面积扩大在一定范围内与压力、时间增加成正比，20kPa、60min组合增幅最大，此后增幅明显减少，并逐渐引发皮肤病理性改变。结论皮肤可在一定范围内通过术中即时扩张获得面积有效增加。