Exosomes Derived from Hypertrophic Scar Fibroblasts Suppress Melanogenesis in Normal Human Epidermal Melanocytes.

Post-burn hypertrophic scars often exhibit abnormal pigmentation. Exosomes play important roles in maintaining normal physiological homeostasis and in the pathological development of diseases. This study investigated the effects of the exosomes derived from hypertrophic scar fibroblasts (HTSFs) on melanocytes, which are pigment-producing cells. Normal fibroblasts (NFs) and HTSFs were isolated and cultured from normal skin and hypertrophic scar (HTS) tissue. Both the NF- and HTSF-exosomes were isolated from a cell culture medium and purified using a column-based technique. The normal human epidermal melanocytes were treated with both exosomes at a concentration of 100 µg/mL at different times. The cell proliferation, melanin content in the medium, apoptotic factors, transcription factors, melanin synthesis enzymes, signaling, signal transduction pathways, and activators of transcription factors (STAT) 1, 3, 5, and 6 were investigated. Compared with the Dulbecco's phosphate-buffered saline (DPBS)-treated controls and NF-exosomes, the HTSF-exosomes decreased the melanocyte proliferation and melanin secretion. The molecular patterns of apoptosis, proliferation, melanin synthesis, Smad and non-Smad signaling, and STATs were altered by the treatment with the HTSF-exosomes. No significant differences were observed between the DPBS-treated control and NF-exosome-treated cells. HTSF-derived exosomes may play a role in the pathological epidermal hypopigmentation observed in patients with HTS.

Pathogenesis and Treatment of Pruritus Associated with Chronic Kidney Disease and Cholestasis.

Itching is an unpleasant sensation that provokes the desire to scratch. In general, itching is caused by dermatologic diseases, but it can also be caused by systemic diseases. Since itching hampers patients' quality of life, it is important to understand the appropriate treatment and pathophysiology of pruritus caused by systemic diseases to improve the quality of life. Mechanisms are being studied through animal or human studies, and various treatments are being tested through clinical trials. We report current trends of two major systemic diseases: chronic kidney disease and cholestatic liver disease. This review summarizes the causes and pathophysiology of systemic diseases with pruritus and appropriate treatments. This article will contribute to patients' quality of life. Further research will help understand the mechanisms and develop new strategies in the future.

Prognostic Nutritional Index and Postoperative Pulmonary Complications in Patients With Major Burns.

INTRODUCTION: Burns can cause multiple organ systemic derangements, particularly in respiratory systems. The prognostic nutritional index (PNI) can predict postoperative outcomes. We evaluated the incidence and risk factors, including PNI, for postoperative pulmonary complications (PPCs) in patients with major burns. METHODS: PNI was calculated as 10 × (serum albumin level) + 0.005 × (total lymphocyte count). Major burn patients admitted to the ICU without burn-induced lung injuries were retrospectively included. The incidence of PPCs was measured within 1 wk of burn surgery. A multivariable logistic regression analysis was performed to evaluate the risk factors for PPCs. Receiver operating characteristic curve analysis and propensity-score matched analysis were conducted to estimate the influence of PNI on PPCs. Outcomes after burn surgery were also assessed. RESULTS: Of 444 major burn patients, 138 (31.1%) showed PPCs. Risk factors for PPCs were PNI, gender, total body surface area burned, interval between burn and surgery, and red blood cell transfusion rate. The area under the curve of PNI for predicting PPCs was 0.709 (cutoff value = 31.5). The incidence of PPCs was significantly higher in the PNI ≤ 31.5 group than in the PNI > 31.5 group (55.7% versus 22.8%, P < 0.001) after propensity-score matching. The intensive care unit stay duration was longer and 90-d mortality was higher in patients who developed PPCs (19 [9-27] d versus 8 [4-17] d, P < 0.001; 11.6% versus 0.3%, P < 0.001). CONCLUSIONS: The prevalence of PPCs in patients with major burns was 31.1% and preoperative PNI was a predictor of PPCs in these patients. PNI ≤ 31.5 was significantly related to a higher incidence of PPCs.

Activation of Transient Receptor Potential Vanilloid-3 Channels in Keratinocytes Induces Pruritus in Humans.

Carvacrol, a natural transient receptor potential vanilloid-3 activator, has been reported to cause pruritus in mice. This study aimed to evaluate the effects of carvacrol and various antipruritic agents in humans. A stimulation test with carvacrol, ß-alanine, and histamine was performed. After application of the pruritic solutions, the skin was stimulated with pinpricks. In inhibition test A, Forsythia suspensa extract, containing forsythoside B (a transient receptor potential vanilloid-3 inhibitor), was applied by pricking prior to stimulation with pruritogens. In inhibition test B, olopatadine solution, tacrolimus ointment, and Scutellaria baicalensis root extract were applied, and carvacrol was applied to the same region. Carvacrol induces moderate pruritus in humans. The pruritus was relieved by Forsythia suspensa extract and olopatadine solution after 20 min of application and by tacrolimus ointment and Scutellaria baicalenis extract after 24 h of application. These results suggest that carvacrol is a pruritogen in humans, and that carvacrol-induced pruritus is inhibited by various antipruritic agents.

Post-Burn Pruritus.

Post-burn pruritus is the pruritus that occurs after burn during the rehabilitation and healing process of burn wounds. The post-burn pruritus is a common and serious complication of burn injury, which severely lowers the quality of life of the patient. Many potential treatments are available for pruritus but there is no consensus of the best single treatment yet. The precise mechanism of post-burn pruritus has not been elucidated, but it appears to have pruritogenic and neuropathic aspects. Clinically, post-burn pruritus tends to be intractable to conventional treatment but rather responds to neuroleptic agents, such as gabapentin and pregabalin. During wound healing, various neuropeptides secreted from the nerves of the skin control epidermal and vascular proliferation and connective tissue cells. When keratinocytes are activated by an itch-inducing substance, they secrete a variety of inflammatory substances that increase the susceptibility of the itch receptor. There are two mechanisms underlying post-burn neuropathic pruritus. The first one is peripheral sensitization. The second one is the intact nociceptor hypothesis. An effective treatment for post-burn pruritus will also be effective in other neuropathic and intractable itching. In this review, we summarized the interaction and mechanism of keratinocytes, immune cells, and nerve fibers related to post-burn pruritus.

Oral Alitretinoin for Patients with Refractory Prurigo.

Background: prurigo is a chronic skin disorder associated with a history of chronic pruritus. The pathogenesis of prurigo is largely unknown and the treatment of prurigo is unsatisfactory and challenging. Conventional systemic treatments may be beneficial; however, their possible side effects and possible transient efficacy is still a problem. We aimed to present the clinical course and effect of treatment with alitretinoin on patients with prurigo nodularis initially treated with conventional treatments like oral antihistamine, cyclosporine, and phototherapy. Methods: all the patients had prurigo nodularis refractory to conventional treatment. Their medical records included demographic features, past medical history, duration of disease, and treatment modalities; and the clinical courses of the patients were reviewed for this retrospective study. We evaluated patient pruritus and skin lesions for the duration. Results: we present reports involving 10 patients with refractory prurigo. All the patients in our cases were treated with oral alitretinoin after previous treatments and reported the improvement of skin lesions and pruritus within 2 weeks to 3 months. Conclusions: we suggest that oral alitretinoin may be an effective and well tolerated treatment option for patients with intractable prurigo. Further clinical studies are warranted to confirm the long-lasting efficacy and safety of alitretinoin for treating patients with prurigo.

Increased activity of TRPV3 in keratinocytes in hypertrophic burn scars with postburn pruritus.

Postburn pruritus is a common distressing sequela of burn wounds. Empirical antipruritic treatment often fails to have a satisfactory outcome, as the mechanism of it has not been fully elucidated. The aim of this study was to evaluate the manifestation of transient receptor potential vanilloid 3 (TRPV3), transient receptor potential ankyrin 1 (TRPA1), and other related receptors in postburn pruritus. Sixty-five burn patients with (n = 40) or without (n = 25) pruritus were investigated, including skin biopsies. Keratinocytes and fibroblasts from skin biopsy samples were separated. Real time-PCR showed that mRNA of TRPV3 was significantly increased in keratinocytes from pruritic burn scars than in keratinocytes from nonpruritic burn scars. With TRPV3 activation, intracellular Ca2+ concentrations were more significantly increased in keratinocytes from pruritic burn scars than in those from nonpruritic ones. Additionally, mRNA and protein levels of protease-activated receptor 2 (PAR2) and neurokinin-1 receptor (NK1R) were also significantly increased in pruritic burn scars. In conclusion, it was confirmed that TRPV3, PAR2, and NK1R were highly expressed in pruritic burn scars. These results may help determine a novel mechanism for postburn pruritus.

Increased expression of three types of transient receptor potential channels (TRPA1, TRPV4 and TRPV3) in burn scars with post-burn pruritus.

Post-burn pruritus is a common distressing consequence of burn wounds. Empirical treatment often fails to have a satisfactory outcome on post-burn pruritus, as the mechanism of post-burn pruritus has not been fully elucidated. The aim of this study was to evaluate the manifestation of transient receptor potential (TRP) channels in post-burn pruritus. Fifty-one burn patients with (n=33) or without (n=18) pruritus were investigated, including skin biopsies. Not unexpectedly, the scarred body area was larger in the former group. In immunohistochemistry, TPRV3 was significantly elevated in the epidermis of burn scars with pruritus. Furthermore, real time- PCR showed that mRNA of TRPA1 and TRPV4 was increased in itching burn scars. Staining for substance P and CGRP did not differ between the 2 grouped, but the former neuropeptide was increased in burn scars. These results may help determine a specific therapeutic approach for post-burn pruritus.

Immunohistochemical Analysis of Postburn Scars following Treatment Using Dermal Substitutes.

BACKGROUND: Post-burn hypertrophic scars commonly occur after burns. Studies that compare dermal substitutes with other treatment methods are insufficient. The purpose was to analyze the histopathological differences in hypertrophic burn scars after Matriderm®+split-thickness skin graft (STSG) and compare with AlloDerm®+STSG, STSG, full-thickness skin graft (FTSG), and normal skin. METHODS: Samples of unburned, normal skin and deep 2nd or 3rd degree burns were obtained from patients who experienced a burn injury in the past to at least 6 months before biopsy, which was performed between 2011 and 2012. All subjects received >6 months of treatment before the biopsy. Intervention groups were normal (63), STSG (28), FTSG (6), Matriderm® (11), and AlloDerm® (18). Immunohistochemical analyses of elastin, collagen I, collagen III, cluster of differentiation 31 (CD31), smooth muscle actin (α-SMA), and laminin from scar and control tissues were performed and compared. RESULTS: α-SMA vascular quantity and vessel width, stromal CD31, and basement membrane laminin expression were not significantly different between normal and intervention groups. Matriderm® group showed no significant difference in elastin, collagen III, stromal CD31 and α-SMA, CD31 vessel width, stromal α-SMA, vessel quantity and width, and laminin length compared to the normal group, meaning they were not significantly different from the normal skin traits. CONCLUSION: Dermal substitutes may be an optimal alternative to address the cosmetic and functional limitations posed by other treatment methods.

Interleukin-31, Interleukin-31RA, and OSMR Expression Levels in Post-burn Hypertrophic Scars.

BACKGROUND: Although several studies have shown the role of interleukin-31 (IL-31) and its receptors in inducing pruritus in certain skin disorders, knowledge of its role in post-burn hypertrophic scars is insufficient. Therefore, the histopathological expression levels of IL-31, IL-31 receptor alpha (IL-31RA), and oncostatin M receptor (OSMR) in post-burn hypertrophic scar tissues were investigated and compared with normal tissue expression levels. METHODS: Samples of hypertrophic scar tissue were obtained from 20 burn patients through punch biopsy. Normal samples were obtained from areas adjacent to the burn injury site of the same patients. Samples were placed in 10% neutral buffered formalin, embedded in paraplast, and processed into serial 5-µm sections. Immunohistochemistry results were semi-quantitatively evaluated for IL-31, IL-31RA, and OSMR. By hematoxylin and eosin staining, epidermal and dermal thickness were assessed with a microscope and digital camera. Intensities were rated on a scale of 1 to 4. RESULTS: Percentages for IL-31, IL-31RA, and OSMR in the epidermal basal layer cell cytoplasm were significantly greater in the burn scar tissue compared to normal skin, as well as the dermal and epidermal thickness (p < .05). There was a significant difference in IL-31 epidermal basal layer intensity in burn scar tissue compared to normal skin (p < .05). Besides the OSMR basal layer intensity, IL-31 and IL-31RA intensities between the burn scar and normal tissues were not significant. However, correlations were significant, indicating that the greater the infiltration percentage, the higher the intensity (p < .05). CONCLUSIONS: IL-31, IL-31RA, and OSMR expression levels are increased in hypertrophic scars compared with normal tissue.

Serial Changes of Heat Shock Protein 70 and Interleukin-8 in Burn Blister Fluid.

BACKGROUND: It has been reported that heat shock protein 70 (HSP70) and interleukin-8 (IL-8) play an important role in cells during the wound healing process. However, there has been no report on the effect of HSP70 and IL-8 on the blisters of burn patients. OBJECTIVE: This study aimed to evaluate the serial quantitative changes of HSP70 and IL-8 in burn blisters. METHODS: Twenty-five burn patients were included, for a total of 36 cases: twenty cases on the first day, six cases on the second, five cases on the third, three cases on the fourth, and two cases on the fifth. A correlation analysis was performed to determine the relationship between the concentration of HSP70 and IL-8 and the length of the treatment period. RESULTS: The HSP70 concentration was the highest on the first day, after which it decreased down to near zero. Most HSP70 was generated during the first 12 hours after the burn accident. There was no correlation between the concentration of HSP70 on the first day and the length of the treatment period. No measurable concentration of IL-8 was detected before 5 hours, but the concentration started to increase after 11 hours. The peak value was measured on the fourth day. CONCLUSION: While HSP70 increased in the first few hours and decreased afterwards, IL-8 was produced after 11 hours and increased afterward in burn blister fluid. These findings provide new evidence on serial changes of inflammatory mediators in burn blister fluid.

Clinical and Histopathological Features of Post Burn Pruritus.

The aim of the study was to evaluate the clinical and histopathological characteristics of patients with post burn pruritus. The authors took skin samples from 62 burn patients with or without pruritus. The measured skin condition includes thickness and paresthesia. Various clinical features were rated on patient assessment scale (PSAS) and observer scar assessment scale. The samples were stained with hematoxylin & eosin, Masson's trichrome, Verhoeff's elastic, and toluidine blue stain. The stained samples were analyzed in terms of epidermal thickness, mononuclear cell infiltration, collagen bundles, elastic fibers, and mast cell distribution. A total of 62 patients were divided into group A (43 patients with pruritus) and group B (19 patients without). The mean (±SD) intensity of itch in group A patients was 4.58 (±3.24). Group A patients had thickened epidermises and higher scores on the PSAS and observer scar assessment scale, especially on the PSAS score. Sensations, including stinging and electric shock sensations, were more frequent in group A than in group B. Histological analysis revealed that group A patients had thinner collagen bundles and more increased mast cell counts, while others did not. Patients suffering from post burn pruritus had distinctive clinical and histopathological features, such as prominent mast cell deposition and thin collagen bundles, compared with group B patients. These results may help better understand post burn pruritus.

Clinical and Histopathological Features of Post Burn Pruritus.

The aim of the study was to evaluate the clinical and histopathological characteristics of patients with post burn pruritus. The authors took skin samples from 62 burn patients with or without pruritus. The measured skin condition includes thickness and paresthesia. Various clinical features were rated on patient assessment scale (PSAS) and observer scar assessment scale. The samples were stained with hematoxylin & eosin, Masson's trichrome, Verhoeff's elastic, and toluidine blue stain. The stained samples were analyzed in terms of epidermal thickness, mononuclear cell infiltration, collagen bundles, elastic fibers, and mast cell distribution. A total of 62 patients were divided into group A (43 patients with pruritus) and group B (19 patients without). The mean (±SD) intensity of itch in group A patients was 4.58 (±3.24). Group A patients had thickened epidermises and higher scores on the PSAS and observer scar assessment scale, especially on the PSAS score. Sensations, including stinging and electric shock sensations, were more frequent in group A than in group B. Histological analysis revealed that group A patients had thinner collagen bundles and more increased mast cell counts, while others did not. Patients suffering from post burn pruritus had distinctive clinical and histopathological features, such as prominent mast cell deposition and thin collagen bundles, compared with group B patients. These results may help better understand post burn pruritus.

Immunohistochemical analysis of neuropeptides (protein gene product 9.5, substance P and calcitonin gene-related peptide) in hypertrophic burn scar with pain and itching.

BACKGROUND: Neuropeptides have been recently reported as having an important role in wound repair, and relief from pain and itching sensation. The aim of this study was to evaluate the effect of neuropeptides on the wound healing process in hypertrophic scar formation that accompanies severe pain and itching sensation. METHODS: We collected forty-three hypertrophic scar specimens from hypertrophic scar release and skin graft under general anesthesia. Immunohistochemical stains for protein gene product (PGP) 9.5, substance P (SP), and calcitonin gene-related peptide (CGRP) were performed. Pain and itching over the scar were recorded using verbal numerical rating scale (VNRS). RESULTS: In the epidermis, PGP 9.5, SP, and CGRP were significantly increased in hypertrophic scars compared with matched unburned skin. In the reticular dermis, SP and CGRP were significantly increased in hypertrophic scars compared with control. The pain and itching verbal numerical rating scale in scar group were significantly higher compared to control. In the papillary dermis, the PGP represented significant correlation with Itching P (correlation coefficient 0.698) and the SP represented significant correlation with pain N (correlation coefficient -0.671). In the reticular dermis, the SP represented significant correlation with pain N (correlation coefficient -0.614) and CGRP represented significant correlation with pain P/Itching P (correlation coefficient 0.801/0.611). CONCLUSIONS: Neuropeptides such as PGP 9.5, SP, and CGRP seem to affect scarring via sensory neurotransmission, it have a regulatory role for pain and itching sensation in hypertrophic scars.

Clinical and histological correlation in post-burn hypertrophic scar for pain and itching sensation.

BACKGROUND: Hypertrophic scar following a burn is caused by the excessive deposit of collagen resulting in an exaggerated wound healing response. The burn patient complains of pain and itching over the scar, which can give rise to cosmetic and functional problems. OBJECTIVE: The aim of this study was to investigate the clinical and histological correlation of a hypertrophic burn scar for itching and pain sensations. METHODS: Thirty-eight patients underwent a scar release and skin graft. the modified Vancouver scar scale and the verbal numerical rating scale were recorded. All biopsies were taken from scar tissue (scar) and normal tissue (normal). Histologically, tissues were observed in the epidermis, the monocytes around the vessels, the collagen fiber, elastic fiber, and the mast cells. RESULTS: The mean total score of MVSS was 8.4±2.7 (pliability 2.0±0.9; thickness 1.8±0.9; vascularity 2.0± 0.9; and pigmentation 2.1±0.9). Pain and itching were 2.4±2.0 and 2.9±3.0. Epidermis were 7.9±2.8 layers (scar) and 4.0±0.8 layers (normal). The collagen fibers were thin and dense (scar) and thicker and loose (normal). The elastic fibers were thin and nonexistent (scar) and thin and loose (normal). Mast cells were 11.2±5.8/high power field (scar) and 7.4±4.1 (normal). CONCLUSION: As the scar tissue thickens, the itching becomes more severe. The stiffness of the scar with the pain appeared to be associated with the condition of the tissue. The correlation between clinical and histological post-burn hypertrophic scars will help further studies on the scar. This helped with the development of the base material for therapeutic strategies.

Pericardial tamponade caused by massive fluid resuscitation in a patient with pericardial effusion and end-stage renal disease -A case report-.

Pericardial tamponade can lead to significant hemodynamic derangement including cardiac arrest. We experienced a case of pericardial tamponade in a patient with end-stage renal disease. Hemodynamic changes occurred by unexpectedly aggravated pericardial effusion during surgery for iatrogenic hemothorax. We quickly administered a large amount of fluids and blood products for massive bleeding and fluid deficit due to hemothorax. Pericardial effusion was worsened by massive fluid resuscitation, and thereby resulted in pericardial tamponade. Hemodynamic parameters improved just after pericardiocentesis, and the patient was transferred to the intensive care unit.

The prevalence of human endogenous retroviruses in the plasma of major burn patients.

BACKGROUND: Approximately 8% of the human genome is composed of retroviral sequences, which are known as human endogenous retroviruses (HERVs) and, have been implicated in both health status and disease. Recently, indirect evidence for a possible role of retroviral elements in the systemic response to stress signals has been provided by several studies. In the present study, we sought to evaluate the relationship between HERVs and major burn in humans. METHOD: We investigated the prevalence of HERV families by reverse transcriptase PCR (RT-PCR) in cell-free plasma samples from patients with burns and from normal individuals. RESULTS: Different prevalences of HERV families were observed in the plasma samples from the burn patient group and normal group. Compared with the prevalences of HERV-W and HERV-K in the normal group, in the burn patient group, the prevalence of HERV-W was significantly lower (P<0.001), but the prevalence of HERV-K was higher (P=0.059). CONCLUSIONS: Our study of the prevalences of HERVs revealed that the activation of certain HERV families may be influenced not only by burns but also by the initial treatments that were used to address these injuries.

The effect of heated breathing circuit on body temperature and humidity of anesthetic gas in major burns.

BACKGROUND: Cold and dry gas mixtures during general anesthesia cause the impairment of cilliary function and hypothermia. Hypothermia and pulmonary complications are critical for the patients with major burn. We examined the effect of heated breathing circuit (HBC) about temperature and humidity with major burned patients. METHODS: Sixty patients with major burn over total body surface area 25% scheduled for escharectomy and skin graft were enrolled. We randomly assigned patients to receiving HBC (HBC group) or conventional breathing circuit (control group) during general anesthesia. The esophageal temperature of the patients and the temperature and the absolute humidity of the circuit were recorded every 15 min after endotracheal intubation up to 180 min. RESULTS: There was no significant difference of the core temperature between two groups during anesthesia. The relative humidity of HBC group was significantly greater compared to control group (98% vs. 48%, P < 0.01). In both groups, all measured temperatures were significantly lower than that after intubation. CONCLUSIONS: The use of HBC helped maintain airway humidity, however it did not have the effect to minimize a body temperature drop in major burns.

Improvement of burn pain management through routine pain monitoring and pain management protocol.

INTRODUCTION: Pain management is an important aspect of burn management. We developed a routine pain monitoring system and pain management protocol for burn patients. The purpose of this study is to evaluate the effectiveness of our new pain management system. METHODS: From May 2011 to November 2011, the prospective study was performed with 107 burn patients. We performed control group (n=58) data analysis and then developed the pain management protocol and monitoring system. Next, we applied our protocol to patients and performed protocol group (n=49) data analysis, and compared this to control group data. Data analysis was performed using the Numeric Rating Scale (NRS) of background pain and procedural pain, Clinician-Administered PTSD Scale (CAPS), Hamilton Depression Rating Scale (HDRS), State-Trait Anxiety Inventory Scale (STAIS), and Holmes and Rahe Stress Scale (HRSS). RESULTS: The NRS of background pain for the protocol group was significantly decreased compared to the control group (2.8±2.0 versus 3.9±1.9), and the NRS of procedural pain of the protocol group was significantly decreased compared to the control group (4.8±2.8 versus 3.7±2.5). CAPS and HDRS were decreased in the protocol group, but did not have statistical significance. STAIS and HRSS were decreased in the protocol group, but only the STAIS had statistical significance. CONCLUSION: Our new pain management system was effective in burn pain management. However, adequate pain management can only be accomplished by a continuous and thorough effort. Therefore, pain control protocol and pain monitoring systems need to be under constant revision and improvement using creative ideas and approaches.