Smac/DIABLO regulates the apoptosis of hypertrophic scar fibroblasts.

In abnormal skin wound healing, hypertrophic scars (HS) are characterized by excessive fibroblast hypercellularity and an overproduction of collagen, leading to atypical extracellular matrix (ECM) remodeling. Although the exact mechanisms of HS remain unclear, decreased HS fibroblast (HSFB) apoptosis and increased proliferation are evident in the development of HS. In this study, the contribution of the second mitochondria-derived activator of caspases/direct inhibitor of apoptosis protein (IAP)-binding protein with a low isoelectric point (pI) (Smac/DIABLO), an apoptosis-promoting protein released from the mitochondria, was investigated in human normal skin and HSFB cultures. The expression of Smac/DIABLO is usually decreased in many malignant tumors compared with normal tissues. Immunohistochemical analysis of skin tissues and the western blot analyses of fibroblasts revealed that the expression of Smac/DIABLO was lower in HS tissues compared with normal skin tissues. Of note, adenovirus-mediated Smac/DIABLO overexpression in the cultured HSFBs significantly reduced cell proliferation, as detected by the cell counting kit-8, and increased caspase-3 and -9 activity, as detected by spectrofluorimetry. In addition, it increased apoptosis, as detected by fluorescence-activated cell sorting (FACS). Furthermore, we found that the silencing of Smac with siRNA in the HSFBs induced a noticeable decrease in caspase-3 and -9 activity, leading to a significant reduction in apoptosis. In addition, the mRNA expression of type I and III pro-collagen detected in the HSFBs was significantly increased following the silencing of Smac with siRNA and was inhibited following Smac/DIABLO overexpression, as shown by real-time RT-PCR. In conclusion, Smac/DIABLO decreases the proliferation and increases the apoptosis of HSFBs. To our knowledge, the data from our study suggest for the first time that Smac/DIABLO is a novel therapeutic target for HS.

[A clinical study of fungal infection in burn patients].

OBJECTIVE: To address the features of the fungal infection after burn injury in clinic. METHODS: Three thousand nine hundred and nine burn patients admitted to our institute from Jan. 2003 to Dec. 2006 were involved in this study. Two thousand two hundred and seventy-one samples were harvested for fungal detection by culture from 467 patients suspected to be infected by fungi based on their clinic manifestations. The collected samples included wound tissue, blood, urine, stool, sputum, catheters and others. The antibiotic sensitivity of the identified fungi were determined by routine method. When same kind of fungus was found from different samples taken from one patient, it was recorded as one positive sample. The samples were ranked in an ascending order as wound secretion, stool, urine, sputum and bronchial alveolar lavage fluid, arteriovenous catheter or urinary catheter, blood. Only the positive sample of the highest rank source was recorded as the positive strain of fungus from this particular patient. RESULTS: It was found 61 fungal positive samples from the 2271 samples collected. Out of 467 patients, 38 strains of fungi were detected from 36 burn patients during the investigated period, the incidence was 0.92% (36/3909). The most three commonest types among the identified 38 strains of fungi were Candida tropicalis (42.1%), Candida albicans (31.6%) and Candida famata (T. Famata, 10.5%). The drug sensitivity tests demonstrated that most of the strains detected in this investigation, with the exception of candida glabrata, were sensitive to most of the routine antimycotics agents such as Amphotericin B, Fluconazole, and Itraconazole etc. Among the 36 fungus positive patients, in 18 patients the burn area exceeded 80% TBSA, 12 patients with 50%-79% TBSA, 4 patients with 30%-49% TBSA, and in 2 patients the burn area was smaller than 30% TBSA. It was found most of the fungal infections (77.78%) occurred 2 weeks after burn injury, and 8 of the 36 fungus-infected patients died (the mortality was 22.22%). Conclusions Further examinations are necessary to confirm the diagnosis in burn patients suspected to have fungal infection. Once fungal infections are confirmed, antimycotic therapy must be started immediately.

[Clinical practice and evaluation of relative fluid resuscitation formula at burn shock stage].

OBJECTIVE: To evaluate the application of the Third Military Medical University (TMMU) formula for fluid resuscitation on the major burn patients during shock stage. METHODS: Seventy-one thermal injury patients (burn area more than 30% TBSA, without especial illness, hospitalization within 8 hour after burn) admitted from 2005 to 2007 were divided into adult group (n = 46), child group (n = 25). Fluid resuscitation was initiated as per the TMMU formula. RESULTS: All patients survived the first 48 hours post burn injury and none developed recognized complications associated with fluid resuscitation. The average infused fluid was 16% approximately 38% more than the calculated in both adult and child groups. The average urine output during the first 24 hours post burn injury was 1.1 approximately 1.2 mL x kg(-1) x h(-1) in the two groups, but reached 1.2 mL and 1.7 mL x kg(-1) x h(-1) during the second 24 hours in adult and child groups respectively. CONCLUSION: TMMU formula for fluid resuscitation is a feasible option for major burn patients. Individual fluid resuscitation, guided by the physiological response, is also important and necessary.