Laser Punch-Out for Acne Scars

Patients with acne scars want smooth facial skin. However, achieving this is difficult with dermabrasion or chemical peeling. Nor can acne scars be covered with cosmetics, due to their ice-picked or cobblestone appearance. Laser resurfacing is more effective and safer than other conventional methods due to its precision with depth control and variable methods of surface cutting. Even depth resurfacing with a laser shows unsatisfactory results, therefore, for the deep-sited acne scar the cutting methods have to be changed according to the depth and pattern of the scar. For 2 years, starting in January 1996, we treated 71 patients with a high-powered CO₂ laser (Ultrapulse). Different resurfacing methods were applied according to the depth and pattern of the scars. For mild depressed scars, even depth resurfacing was done. For moderate-depth acne scars, the shoulder technique was also used. For the deepest and ice-picked scars, the laser punch-out was combined. Laser resurfacing was carried out at 300–500 mJ, with two to five passes. Laser punch-out was done at 500 mJ, with three to seven continuous passes on the ice-picked scar. From the pathologic findings of acne scars showing that there was thick intradermal scar, we knew that laser punch-out was necessary for improvement of acne scars. Depth-wide, the ice-picked scars improved by over 80% and the sharp demarcated margin of the acne scar faded out. Most of the patients with acne scars were satisfied with laser resurfacing. Only six patients had a second laser treatment, with an interval of 12 months. There were no hypertrophic scars after laser resurfacing, but erythema lasted for 3–12 months. Patients taking oral retinoic acid were not contraindicated for laser resurfacing but required special caution because they had atrophic skin and delayed wound healing. Laser resurfacing is the most versatile method for acne scars, with a high-powered CO₂ laser. The laser punch-out method is better than even depth resurfacing for improving deep acne scars and can be combined with the shoulder technique or even depth resurfacing according to the type of acne scar.     

Combination treatment utilizing fractional ablative and continuous wave CO2 lasers for hypertrophic burn scars

BackgroundHypertrophic scars are devastating outcomes of severe burn injuries, producing physical and mental burdens. Adequate treatment is of benefit to relieve these burdens. Laser therapy has shown scar reducing effects. In this study, we compared outcomes after combination of two different lasers or single laser treatment to treat severe hypertrophic burn scars.MethodsForty patients with hypertrophic burn scars were included in one of two therapeutic groups: continuous wave CO₂ laser and fractional ablative CO₂ laser group (group 1, n = 20) or fractional ablative CO₂ laser alone group (group 2, n = 20). Hypertrophic scars were evaluated by the observer-rated Vancouver Scar Scale (VSS) before and after treatment and by patient-completed questionnaires after treatment. Comparative analyses were performed before and after treatment, and time-dependent improvement was also analyzed.ResultsForty patients (54 hypertrophic scars) completed the laser treatment protocols. Group 1 exhibited significantly more improvement in VSS vascularity, pliability, and height indices than group 2 (p < 0.05). Time-dependent analysis of total VSS scores suggested that group 1 experienced more improvement during a shorter treatment period (p < 0.05). For patient-reported outcomes, group 1 noted better grades than group 2 in four indices, namely scar appearance, scar thickness, pain, and pruritus (p < 0.05).ConclusionEffective scar reduction was achieved using combination laser treatment, with significant improvement in multiple observer- and patient-reported outcomes. The shorter treatment period of the combination method can be a merit, as prolonged hypertrophic scars may increase morbidity. Nonetheless, cautious treatment protocols are necessary to avoid undesirable sequelae related to laser application.     

Fractional CO2 laser treatment for burn scar improvement: A systematic review and meta-analysis

Burn injury can cause abnormal healing and pathologic scar formation that significantly impairs patients’ ability to return to baseline levels of functioning. Quality of life can be significantly diminished due to pain, stiffness, contracture, and the psychological burden of disfigurement. Traditional scar therapies such as silicone sheeting and compression garments are highly reliant on patient compliance, and have not demonstrated satisfactory efficacy. Even more invasive therapies such as intralesional medication delivery or surgical contracture release have high recurrence rates. Recently, fractional CO₂ laser therapy has emerged as a promising treatment modality for burn scars, but there is a lack of recent studies that aggregates extant data to demonstrate outcomes after laser therapy.To address this, we conducted a systematic review and meta-analysis to determine the efficacy of fractional CO₂ lasers in treating burn scars, and found that laser therapy alone yielded statistically significant improvements in scar profiles. There were very few reports of adverse effects, most treatments were provided as outpatient, and both patient and burn practitioners reported high satisfaction. By sharing our findings, we hope that more burn practitioners will consider adopting laser therapy as a safe and cost-effective first-line therapy for burn scar management.     

Patient satisfaction after fractional ablation of burn scar with 2940 nm wavelength Erbium-Yag laser

Objective

Fractional laser therapy is a new treatment with potential benefit in the treatment of burn scars. We sought to determine patient satisfaction after burn scar treatment with the Erbium-Yag laser.

增生性瘢痕中基质金属蛋白酶及其抑制因子基因的表达

目的 了解基质金属蛋白酶2(MMP-2,又称明胶酶A)、MMP-9(又称明胶酶B)及其金属蛋白酶1组织抑制因子(TIMP-1)在增生性瘢痕不同形成时期的基因表达.方法 提取16例人体不同时期增生性瘢痕样本和8例正常皮肤样本总RNA,分离mRNA,用反转录-聚合酶链反应法检测MMP-2、MMP-9和TIMP-1基因在不同样本中的表达.结果 在正常皮肤中MMP-2、MMP-9和TIMP-1基因转录产物的灰度比值分别为(3.8±0.7)%、(5.8±4.4)%、(30.3±3.0)%,在增殖期瘢痕中分别为(13.5±4.5)%、(18.4±4.7)%、(37.7±4.3)%,明显高于正常皮肤(P＜0.05).成熟期瘢痕MMP-2和MMP-9基因表达量已恢复至正常水平,但TIMP-1基因较正常皮肤仍持续高表达(P＜0.05).结论 MMP-2、MMP-9和TIMP-1基因表达增强可能是增生性瘢痕形成的机制之一,MMP-2和MMP-9基因表达降低可能与增生性瘢痕达到相对稳定的成熟状态有关.     

Nd：YAG激光和CO_2点阵激光治疗面部痤疮凹陷性瘢痕疗效比较分析

目的：比较CooltouchⅢ1320nm Nd：YAG激光和KL型10600nm CO2点阵激光治疗面部痤疮萎缩、凹陷性瘢痕的疗效及安全性。方法：痤疮萎缩、凹陷性瘢痕患者85例,采用CooltouchⅢ1320nmNd：YAG激光治疗35例,KL型10600nm CO2点阵激光治疗50例。治疗前后使用ECCA权重评分表对治疗部位进行评分,比较两种治疗方案的疗效差异。定量测量患者疼痛度、停工期及并发症发生比例,对比两种激光治疗的安全性。结果：CO2点阵激光治疗组治疗后ECCA评分平均降低17.4,CooltouchⅢ治疗组降低为13.1,两者差异有统计学意义（P〈0.05）。CO2点阵激光平均疼痛度、停工期及并发症发生率均大于CooltouchⅢ治疗组。结论：两种方法均可用于治疗痤疮后萎缩、凹陷性瘢痕,KL型10600nm点阵激光比CooltouchⅢ1320nm激光疗效更为显著,尤其对于重度痤疮凹陷性瘢痕患者,但患者疼痛感明显,停工期长,有一定持续性红斑和色素沉着的风险。后者治疗时疼痛感较轻微,停工期较短,未见明显色素沉着发生,但需要疗程相对长,疗效相对稍差。故患者可以根据自身需求选择治疗。     

The importance of biomechanics and the kinetic chains of human movement in the development and treatment of burn scars – A narrative review with illustrative cases

BackgroundBurn scars are a major clinical sequelae of severe burn wound healing. To effectively establish a successful treatment plan and achieve durable results, understanding the pathophysiology of scar development is of utmost importance.MethodsA narrative review of the principles of the kinematic chain of movement and the hypothesised effect on burn scar development based on properties of burn scars was performed. An examination of the literature supporting these concepts is presented in conjunction with illustrative cases, with a particular focus on the effect of combination treatments that include ablative fractional resurfacing with surgical contracture releases.DiscussionAblative fractional resurfacing combined with the surgical release of contractures are an effective treatment modality for burn scar reconstruction. This treatment approach seems particularly effective because it is one of the only approaches where the principles of functional kinematics can be addressed when tailoring a reconstructive approach to an individual burn patient. The presented cases illustrate the importance of recognising and including the principles of functional kinematic chains in any reconstructive treatment approach for burn scars. Further, epifascial contracture bands are cord like structures which can be found underneath the subcutaneous fat of scar contractures which follow the principles of functional kinematics. Contractures can be more efficiently released if these structures are divided as well.ConclusionAblative fractional resurfacing combined with local tissue re-arrangements is a promising approach to address the underlying forces leading to hypertrophic burn scarring. To achieve an optimal outcome, it is essential to recognise and address the origin of the pathology when treating burn scars. Ablative fractional laser resurfacing allows a different scar approach as it is not limited to one surgical site and thus enables for effective treatment at the cause of the pathology.     

Immunohistochemical analysis of TIMP-2 and collagen types I and IV in experimental spinal cord ischemia–reperfusion injury in rats

Abstract

Background

Thoracic and thoracoabdominal aortic intervention carries a significant risk of spinal cord ischemia. The pathophysiologic mechanisms that cause hypoxic/ischemic injury to the spinal cord have not been totally explained. In normal spinal cord, neurons and glial cells do not express type IV collagen. Type IV collagen produced by reactive astrocytes is reported to participate in glial scar formation. Tissue inhibitors of metalloproteinases (TIMPs) are endogenous inhibitors that regulate the activity of the matrix metalloproteinases (MMPs). TIMP-2 binds strongly with MMP-2, facilitating activation by membrane-type MMP. Imbalance between TIMPs and MMPs can lead to excessive degradation of matrix components. Type IV collagen involved in the blood–brain barrier disruption and glial scar formation, TIMP-2 influences MMP-2 that controls degradation of collagen I and IV.

Objective

To examine the immunohistochemical analysis of TIMP-2 and collagen types I–IV in experimental spinal cord ischemia–reperfusion in rats.

Methods

Thirty-two male Wistar rats weighing 250–300 g were divided into four groups: group S: sham group (n = 8); group 0P: 30-minute occlusion without perfusion (n = 8); group 3P: 30-minute occlusion and 3-hour perfusion (n = 8); and group 24P: 30-minute occlusion and 24-hour perfusion (n = 8). Infrarenal aorta was cross-clamped at two sites by using two aneurysm clips for 30 minutes. Reperfusion was provided after removal of the clips. Lumbar spinal cord segments were removed for immunohistochemical analysis.

Results

TIMP-2 and collagen staining in 3-hour perfused (3P) group were nearly the same with sham group (S). TIMP-2 and collagen staining increased in the 24-hour perfused group.

Conclusion

Alterations in collagen levels may relate to the biphasic breakdown of the blood–brain barrier and collagen staining in new cell types with relation to glial scar formation. Our results demonstrate that 3-hour perfusion after occlusion in hypoxic/ischemic spinal cord injury seems to be the critical reversible period.     

Inflammatory and infectious complications of laser therapy in treatment of hypertrophic burn scars: Correlations in literature review & case reports

IntroductionHypertrophic burn scars contribute to morbidity through secondary symptoms of pain, pruritus, and scar contracture. Traditional treatment methods are now augmented by the use of monochromatic light therapies, which are generally accepted as safe and effective. However, little literature is available regarding the complications of laser treatments of hypertrophic burn scars and even less regarding inflammatory and infectious complications.MethodsA literature search using PubMed was performed to identify literature pertaining to infectious and inflammatory complications of cutaneous laser treatments. Additionally, we reviewed cases of inflammatory and infectious complications occurring at our institution after laser treatment of hypertrophic burn scars.ResultsWe identified 1 publication related to complications of laser therapy in the treatment of burn scars. In this series of 163 laser sessions, the reported incidence of adverse events was 25.1%, of which 6 cases 3.7% were related to inflammatory and infectious processes. In the 391 laser sessions performed at our institution (December, 2015 and July, 2016) 9 cases of inflammatory and infectious complications were noted yielding an incidence of 2.3%. Cases included 3 each of cellulitis, Systemic Inflammatory Response Syndrome (SIRS), and complicated SIRS.ConclusionWe found the most common inflammatory complication was SIRS with MSSA positive wound cultures. Three cases underwent hospitalization along with fluids and vasopressors, despite negative blood cultures. In light of the high prevalence of MSSA in the natural skin flora and negative blood cultures, the inability to establish a true source of infection lead to declaring these cases “complicated SIRS” and not sepsis. Correlative factors that may have led to complications reported in our cases were: preoperative evidence of infection, no preoperative antibiotics administered, no postoperative antibiotic dressings, combined procedures, and large treatment areas. The true mechanism of inflammatory and infectious complication is yet to be determined, but we postulate that these factors place a greater challenge on an already burdened immune system. Determining whether this is a true causal mechanism, leading to an aggravated inflammatory response, benefits from further investigation.Applicability of research to practiceWe urge institutions preforming such procedures to advise patients on preoperative wound preparation. We recommend that each individual with a preexisting history of infection and/or preoperative culture evidence of infection receive antibiotics, particularly when undergoing combined procedures or procedures involving higher surface areas. Although complications are rare, the benefits of these precautionary measures outweigh the risks when it comes to prevention and management.     

Effectiveness and safety of ablative fractional CO2 laser for the treatment of burn scars: A case-control study

BackgroundBurn scars are a major clinical challenge. The aim of this study was to determine the effectiveness and safety of one treatment with the ablative fractional CO₂ laser (AFL-CO₂) compared to standard burn scar treatment.MethodFrom December 2014 to October 2018 patients were prospectively recruited and treatment effects analyzed by assessing various outcome parameters from the date of first consultation and after treatment. A case control study was conducted looking at the impact of one AFL-CO₂ treatment compared to a cohort subjected to conventional conservative treatment. Adverse effects were noted at follow up.Results187 patients were included, with 167 in the AFL-CO₂, and 20 in the control cohort. Baseline demographics and scar characteristics showed no significant differences. Ultrasound measured scar thickness as well as the Vancouver Scar Scale (VSS) revealed a significant reduction in the treatment cohort, but no significant improvement in the control group. The POSAS-O was significantly improved in both cohorts. Subjective parameters (POSAS-P, DN4-Pain, and modified D4Pruritus scores) decreased significantly in the AFL-CO₂ cohort but remained unchanged in the control group. The BSHS-B quality of life score increased significantly in the AFL-CO₂ group, but worsened at the follow up of the untreated patients. Sub-domain analyses found the biggest differences in Affect, Body Image, Heat Sensitivity, Treatment and Work. Complications occurred in 5 patients (2.9%).ConclusionsThis study demonstrates that AFL-CO₂ is an effective and safe treatment modality for burn scars improving thickness, symptoms and quality of life of burn survivors when compared to conventional scar treatment.     

Pulsed dye laser in burn scars: Current concepts and future directions

Hypertrophic scarring after partial-thickness burns is common, resulting in raised, erythematous, pruritic, and contracted scars. Treatment of hypertrophic scars, especially on the face, is challenging and has high failure rates. Excisional treatment has morbidity and can create iatrogenic deformities. After an extensive experience over 10 years with laser therapy for the treatment of difficult scars, the pulsed dye laser (PDL) has emerged as a successful alternative to excision in patients with hypertrophic burn scars. Multiple studies have shown its ability to decrease scar erythema and thickness while significantly decreasing pruritis and improving the cosmetic appearance of the scar. The history of laser therapy and the mechanism of action and results of the PDL in burn scars will be reviewed. The PDL should become an integral part of the management of burn scarring and will significantly decrease the need for excisional surgery.     

Early intervention by Z-plasty combined with fractional CO2 laser therapy as a potential treatment for hypertrophic burn scars

The aim of this study is to determine whether Z-plasty combined with fractional CO₂ laser therapy can be a potential management option for hypertrophic burn scars in the proliferation stage. A total of 105 patients (46 male and 59 female patients) diagnosed with hypertrophic scars under tension but without any functional limitations were enrolled in this study. The Vancouver Scar Scale (VSS) score and scar height were analyzed and compared. The VSS scores for all scars were improved in all groups after treatment. The scar height was also significantly decreased in each group after treatment (P < 0.05). In the C group, the scar height decreased significantly to 2.62 ± 0.21 mm, which was the maximum extent at the ≦ 6 month time point compared to the decrease in the other groups. Compared to the > 12 month time point for the C group, there was a significant difference between the ≦ 6 month time point for the L group and the > 12 month time point for the Z group. The proportion of satisfied patients was highest at 89.47% at the ≦6 month time point in the C group and lowest at 65.52% at the > 12 month time point in the L group. Six representative cases are presented. Z-plasty can decrease the thickness of a hypertrophic burn scar, which not only reduces the scar tension but also makes it easy to treat the scar with a fractional CO₂ laser. Subsequent treatment with a fractional CO₂ laser can better improve the color and texture of the scar.     

Patient-reported scar quality of donor-sites following split-skin grafting in burn patients: Long-term results of a prospective cohort study

BackgroundSkin grafting is the current gold standard for treatment of deeper burns. How patients appraise the donor-site scar is poorly investigated. The aim of this study was to evaluate long-term patient-reported quality of donor-site scars after split skin grafting and identify possible predictors.MethodsA prospective cohort study was conducted. Patients were included in a Dutch burn centre during one year. Patient-reported quality of donor-site scars and their worst burn scar was assessed at 12 months using the Patient and Observer Scar Assessment Scale (POSAS). Mixed model analyses were used to identify predictors of scar quality.ResultsThis study included 115 donor-site scars of 72 patients with a mean TBSA burned of 11.2%. The vast majority of the donor-site scars (84.4%) were rated as having at least minor differences with normal skin (POSAS item score ≥2) on one or more scar characteristics and the overall opinion on 80.9% of the donor-site scars was that they deviated from normal skin 12 months after surgery. The overall opinion on the donor-site scar was 3.2 ± 2.1 vs. 5.1 ± 2.4 on the burn scar. A younger age, female gender, a darker skin type, and location on the lower leg were predictors of reduced donor-site scar quality. In addition, time to re-epithelization was associated with scar quality.ConclusionThis study provided new insights in long-term scar quality of donor-sites. Donor-site scars differed from normal skin in a large part of the population 12 months after surgery. Results of this study can be used to inform patients on the long-term outcomes of their scars and to tailor preventive or therapeutic treatment options.     

An imbalance between matrix metalloproteinase-2 and tissue inhibitor of matrix metalloproteinase-2 contributes to the development of early diabetic nephropathy.

BACKGROUND: High glucose and angiotensin-II (Ang-II) levels are the known important mediators of diabetic nephropathy. However, the effects of these mediators on matrix metalloproteinase-2 (MMP-2) and on tissue inhibitor of metalloproteinase-2 (TIMP-2) in proximal tubule cells have yet to be fully examined within the context of early stage diabetic nephropathy. METHODS: In this study, we attempted to characterize changes in MMP-2 and TIMP-2 in streptozotocin-induced diabetic rats. To further examine the molecular mechanisms involved, we evaluated the effects of high glucose (30 mM) or Ang-II on MMP-2, TIMP-2 and collagen synthesis in proximal tubule cells, and investigated whether MMP-2 and TIMP-2 are regulated via the TGF-beta1 pathway. RESULTS: In streptozotocin-induced diabetic rats, TIMP-2 mRNA and protein levels were significantly higher than in controls. Urinary protein excretion also showed a significant positive correlation with glomerular and tubular TIMP-2 protein expressions, and a negative correlation with MMP-2 expression. In cultured cells, both high glucose and Ang-II induced significant increases in TGF-beta1, TIMP-2, and in collagen synthesis, and significant decreases in MMP-2 gene expression and activity, and thus disrupted the balance between MMP-2 and TIMP-2. Moreover, treatment with a selective angiotensin type 1 (AT1) receptor antagonist significantly inhibited Ang-II mediated changes in TGF-beta1, MMP-2, TIMP-2, and in collagen production, suggesting the role of the AT1 receptor. The addition of exogenous TGF-beta1 produced an effect similar to those of high glucose and Ang-II. Furthermore, the inhibition of TGF-beta1 protein prevented Ang-II-induced MMP-2 and TIMP-2 alterations, suggesting the involvement of a TGF-beta1 pathway. CONCLUSIONS: High glucose or Ang-II treatment induce alterations in MMP-2 and TIMP-2 balance, which favour TIMP-2 over-activity. Moreover, Ang-II-mediated changes in the productions of MMP-2 and TIMP-2 occur via AT1 receptors and a TGF-beta1-dependent mechanism. These results suggest that an imbalance between the MMP-2 and TIMP-2, caused primarily by an increase in TIMP-2 activity, contributes to the pathogenesis of diabetic nephropathy.     

不同年龄烧伤患者增生性瘢痕的胶原构成及影响因素的研究

目的　观察不同年龄患者增生性瘢痕 (HS)胶原构成及相关因素的变化 ,并探讨其规律。　方法　HS患者 30例 ,按年龄分为 1～ 19岁组和 2 0～ 5 0岁组 ,取患者对侧部位的正常皮肤(NS)作对照组。采用原位杂交、链酶亲和素 过氧化物酶复合物免疫组织化学方法 (SABC)及图像分析法 ,观察胶原比例和转化生长因子β1(TGFβ1)、胶原酶 (MMP 1)、金属蛋白酶组织抑制剂 (TIMP 1)的变化。结果　 1～ 19岁HS组Ⅰ /Ⅲ型胶原比例平均为 6 .4 8,2 0～ 5 0岁HS组为 3.76 ,但两个年龄组各病程之间Ⅰ /Ⅲ型胶原比例均无明显差异。 1～ 19岁HS组TGFβ1呈高表达 ,与 2 0～ 5 0岁HS组比较 ,差异有非常显著性意义 (P <0 .0 1)。TIMP 1mRNA表达各年龄组之间无明显差别 ,HS组的表达显著高于NS组 ,MMP 1的表达明显低于TIMP 1,与NS组MMP 1的表达比较 ,差异无显著性意义 (P >0 .0 5 )。　结论　 (1)HS中TGFβ1的表达与年龄呈负相关 ,TGFβ1的高表达促使Ⅰ /Ⅲ型胶原比例增高甚至比例失调。 (2 )高表达的TIMP 1通过抑制MMP 1的表达促使HS形成 ,其表达与年龄无明显相关性。     

Immunohistochemical analysis of TIMP-2 and collagen types I and IV in experimental spinal cord ischemia-reperfusion injury in rats

Background

Thoracic and thoracoabdominal aortic intervention carries a significant risk of spinal cord ischemia. The pathophysiologic mechanisms that cause hypoxic/ischemic injury to the spinal cord have not been totally explained. In normal spinal cord, neurons and glial cells do not express type IV collagen. Type IV collagen produced by reactive astrocytes is reported to participate in glial scar formation. Tissue inhibitors of metalloproteinases (TIMPs) are endogenous inhibitors that regulate the activity of the matrix metalloproteinases (MMPs). TIMP-2 binds strongly with MMP-2, facilitating activation by membrane-type MMP. Imbalance between TIMPs and MMPs can lead to excessive degradation of matrix components. Type IV collagen involved in the blood–brain barrier disruption and glial scar formation, TIMP-2 influences MMP-2 that controls degradation of collagen I and IV.

Objective

To examine the immunohistochemical analysis of TIMP-2 and collagen types I–IV in experimental spinal cord ischemia–reperfusion in rats.

Methods

Thirty-two male Wistar rats weighing 250–300 g were divided into four groups: group S: sham group (n = 8); group 0P: 30-minute occlusion without perfusion (n = 8); group 3P: 30-minute occlusion and 3-hour perfusion (n = 8); and group 24P: 30-minute occlusion and 24-hour perfusion (n = 8). Infrarenal aorta was cross-clamped at two sites by using two aneurysm clips for 30 minutes. Reperfusion was provided after removal of the clips. Lumbar spinal cord segments were removed for immunohistochemical analysis.

Results

TIMP-2 and collagen staining in 3-hour perfused (3P) group were nearly the same with sham group (S). TIMP-2 and collagen staining increased in the 24-hour perfused group.

Conclusion

Alterations in collagen levels may relate to the biphasic breakdown of the blood–brain barrier and collagen staining in new cell types with relation to glial scar formation. Our results demonstrate that 3-hour perfusion after occlusion in hypoxic/ischemic spinal cord injury seems to be the critical reversible period.     

Significance of circulating matrix metalloproteinase-9 to tissue inhibitor of metalloproteinases-2 ratio as a predictor of disease progression in patients with metastatic renal cell carcinoma receiving sunitinib

ObjectivesTo assess the significance of circulating matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) as predictors of disease progression in patients with metastatic renal cell carcinoma (mRCC) receiving sunitinib.Materials and methodsCirculating levels of MMP-2, MMP-9, TIMP-1, and TIMP-2 in sera from 52 patients with mRCC treated with sunitinib were measured at the baseline and on the first day of each treatment cycle until progression using enzyme-linked immunosorbent assays.ResultsThe baseline level of MMP-9 in nonresponders to sunitinib was significantly higher than that in responders, whereas the baseline level of TIMP-2 in nonresponders was significantly lower than that in responders. However, there were no significant differences in the serum levels of MMP-2 and TIMP-1 between responders and nonresponders. The serum MMP-9/TIMP-2 ratio at the baseline in nonresponders was also significantly higher than that in responders. Univariate analysis showed that the MMP-9/TIMP-2 ratio, but not MMP-9 and TIMP-2 levels, was significantly correlated with progression-free survival, and the MMP-9/TIMP-2 ratio, in addition to the Memorial Sloan-Kettering Cancer Center classification and C-reactive protein level, appeared to be independently associated with progression-free survival on multivariate analysis. Furthermore, despite the lack of significant differences in the serum levels of MMP-9 and TIMP-2 between the baseline and the time of progression, the MMP-9/TIMP-2 ratio at the time of progression was significantly elevated compared with the baseline ratio.ConclusionsAn imbalance between the serum MMP-9 and TIMP-2 levels could be a novel biomarker to predict disease progression in patients with mRCC under treatment with sunitinib.     

Atrophic and a Mixed Pattern of Acne Scars Improved With a 1320-nm Nd:YAG Laser

BACKGROUND: Acne scar correction remains a challenge to the dermatologic surgeon. With nonablative laser resurfacing, this correction is imputed to dermal collagen remodeling and acne scar reorganization. Although atrophic acne scars tend to respond to laser treatment, the deeper ice pick and boxcar scars tend to be laser resistant. OBJECTIVE: To investigate the treatment of atrophic and a mixed pattern of facial acne scars, we evaluated a 1320-nm Nd:YAG laser. Twelve subjects with atrophic facial acne scars (N=6) or a combination of atrophic and pitted, sclerotic, or boxcar scars (N=6) received three laser treatments. Physician and patient acne scar ratings were performed at baseline and at 6 months after the last treatment. Acne scars were rated with a 10-point severity scale. RESULTS: Mean acne scar improvement was 1.5 points on physician assessments (P=0.002) and 2.2 points on patient assessments (P=0.01). Acne scars were rated more severely by patients than by the physician at all intervals. There were no noted complications at 6 months. CONCLUSION: The 1320-nm Nd:YAG laser is a safe and effective nonablative modality for the improvement of atrophic and a mixed pattern of facial acne scars.     

Platelet-derived growth factor stimulates matrix metalloproteinase-2 secretion in cultured human mesangial cells

Background. Platelet-derived growth factor (PDGF) is an important mediator of mesangial proliferative glomerulonephritis. Little is known about the role of PDGF in the regulation of intraglomerular extracellular matrix turnover. Method. Effects of PDGF on the secretion of matrix metalloproteinase-2 (MMP-2), tissue inhibitor of MMP-2 (TIMP-2), and type IV collagen by cultured human mesangial cells (HMCs) were examined in the present study. Secretion of MMP-2, TIMP-2, and type IV collagen by HMCs was quantified with an enzyme immunoassay. Collagenase activity of HMCs was evaluated by gelatin zymography. Results. Recombinant human PDGF (10–20 ng/ml) stimulated MMP-2 secretion by HMCs in a dose-dependent fashion. PDGF (20 ng/ml) increased TIMP-2 secretion by HMCs to a lesser extent. Enhanced activity of 72-kDa collagenase derived from HMCs incubated with PDGF was demonstrated by zymography. Although PDGF alone did not affect type IV collagen secretion by HMCs, PDGF increased type IV collagen secretion in the presence of TIMP. Conclusions. PDGF may contribute to intraglomerular matrix turnover by up-regulating secretion and activation of MMP-2 by HMCs. Received: January 24, 2001 / Accepted: September 13, 2002 Correspondence to:H. Osawa     

Pulsed dye laser therapy and z-plasty for facial burn scars: the alternative to excision

Hypertrophic scarring after partial thickness facial burns is common when epithelialization takes longer than 3 weeks. Well-healed areas continue to mature unfavorably, resulting in raised, erythematous, and contracted scars. Excisional treatment of such scars has morbidity and can create iatrogenic deformities. The flashlamp-pumped, pulsed dye laser (PDL) in combination with z-plasty can be used as a successful alternative to excision in patients with facial hypertrophic burn scars. Fifty-seven patients with hypertrophic facial burn scars (mean age 12 years; range, 2-21 years) were treated with the PDL over the past 8 years. Thirty-four patients (60%) were also treated with z-plasties to relieve scar tension. There was one complication of postoperative blistering. Patients were divided into 3 groups based on time from burn to initial laser treatment. Group I (<1 year) had 11 patients and the laser diminished scar proliferation in these patients. Group II (1-4 years) included 24 patients and treatment resulted in reversal of hypertrophic scarring and elimination of erythema. Group III (>5 years) consisted of 22 patients. The PDL was effective in treating their stable and persistent erythema as long as 17 years after burn injury. No scars required excision in this cohort of 57 patients. The PDL should become an integral part of the management of facial burn scarring and will significantly decrease the need for excisional surgery.