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Pressure ulcers (PUs) are a complex and serious clinical problem. Deep tissue injury (DTI) is either the outcome or the trigger of deep PUs. However, the cellular and molecular mechanisms that contribute to the pathogenesis of deep PUs remain unclear. In this study, the degeneration characteristics and increased autophagy and apoptosis were observed in deep PU muscle tissues. Muscular proteome of deep PU revealed that a total of 520 proteins were differentially expressed, particularly, JAK2 was down-regulated. Intriguingly, expression of JAK2 in C2C12 myoblasts exposed to oxygen-glucose deprivation and reoxygenation (OGD/R) insult was also distinctly reduced. Ex vivo, we transfected C2C12 myoblasts with lentivirus carrying the JAK2 plasmid and found that JAK2-overexpressed myoblasts exhibited a decrease in autophagy and apoptosis after OGD/R treatment, as well as less cell death. Finally, Western blot analysis determined that p-JAK2, p-AKT, p-mTOR and p-ERK1/2 levels were significantly elevated, accompanied by JAK2 overexpression but without p-STAT3, and inhibition of the AKT and ERK1/2 pathway resulted in elevated apoptosis and/or autophagy. These results demonstrated that JAK2 may play an important protective role in muscular ischemia and reperfusion injury during DTI development by inhibition of autophagy and apoptosis through the AKT and ERK1/2 pathways., Competing Interests: None.

Lymphangiogenesis has been regarded as a physiological response to pathologic stimuli. The abnormal proliferation of lymphatic endothelial cell (LECs) and lymphangiogenesis is involved in the development of lymphatic disorders. Reportedly, VEGFC/VEGFR3 plays a key role in lymphangiogenesis; moreover, VEGFC/VEGFR3 exerts their cellular effects through activation of Ca 2+ signaling in several cell types. Herein, we demonstrated that VEGFC significantly up-regulated LEC proliferation through VEGFR3; moreover, VEGFC/VEGFR3 induced Ca 2+ signaling activation. By using online tools, miR-128 and miR-3916 were predicted as candidate upstream miRNAs which might target VEGFC/VEGFR3. As verified using Immunoblotting assays, miR-128 significantly regulated the protein levels of VEGFC/VEGFR3, whereas miR-3916 only slightly modulated VEGFC and VEGFR3 proteins. Contrary to VEGFC, miR-128 overexpression remarkably suppressed LEC proliferation, Ca 2+ release and ERK1/2-Akt signaling; moreover, the effect of VEGFC could be partially attenuated by miR-128. In summary, miR-128 interacts with the 3'-UTR of VEGFC and VEGFR3 to inhibit their expression, thus suppressing LEC proliferation through Ca 2+ and ERK1/2-Akt signaling. Taken together, we provided novel experimental basis for miRNA-regulated LEC proliferation through Ca 2+ signaling., (Copyright © 2018. Published by Elsevier Ltd.)

Objective: To analyze the etiology and clinical characteristics of Marjolin's ulcer, and to explore its prevention and treatment., Methods: Medical records of 187 patients with Marjolin's ulcers admitted to the Department of Burns and Reconstructive Surgery of Xiangya Hospital of Central South University from January 1998 to May 2015 were retrospectively analyzed, including gender, age of onset of initial injury or primary disease, age of onset of Marjolin's ulcer, initial injury or primary disease, length of latency, lengths of pre- and post-ulceration periods, lesion site, lesion type, lesion area, local scar tension, histopathological type, degree of carcinoma cell differentiation, bone invasion and lymphadenopathy, treatment, and prognosis. The relationships between the age of onset of initial injury or primary disease and the length of latency, and the length of pre-ulceration period and the length of post-ulceration period were assessed by Spearman correlation analysis. The recurrence rates were processed with Fisher's exact test., Results: (1) Among the patients, the ratio of male to female was nearly 1.6:1.0. The age of onset of initial injury or primary disease was 0.17-78.00 (17±18) years, and the age of onset of Marjolin's ulcers was 18-84 (49±14) years. (2) The most common initial injury among the patients was flame burn. The length of latency was 0.25-74.00 (32±16) years, and the lengths of pre- and post-ulceration periods were 0-73.00 (26±19) years and 0.08-59.00 (6±11) years respectively. The common lesion sites were the lower limbs and head and face. The rodent ulcer was the most common lesion type, and the lesion area was 1-625 (69±110) cm(2). There were obviously negative correlations between the age of onset of initial injury or primary disease and the length of latency, as well as the length of pre-ulceration period and the length of post-ulceration period (with r values respectively -0.71 and -0.50, P values below 0.01). The pathological scars of strong tension around lesions were seen in 176 cases. (3) The major histopathological type was squamous cell carcinoma, with high cell differentiation in most cases. (4) Bone invasion of carcinoma cells was observed in 59 cases. Lymph node enlargement was observed in 100 cases, and lymph node metastasis was observed in 18 cases. (5) Twenty patients did not receive any surgery, while 167 patients were treated by surgery with lesion extended resection as the main method. According to the condition of wound after the lesion extended resection, the wounds were mainly repaired by skin grafting and transplantation of local skin flap. The majority of wounds in 139 patients who underwent lesion extended resection were repaired in one surgery. Twenty-eight patients out of 104 followed-up cases had recurrence after surgery, mainly seen on head and face, upper limb, lower limb, and buttock, and there was no significant difference among them (P>0.05). The recurrence time of most patients was longer than 6 months after cure., Conclusions: Patients with Marjolin's ulcers in younger age of onset of initial injury or primary disease tend to have longer latency, during which the shorter the pre-ulceration period is, the longer the post-ulceration period will be. Marjolin's ulcers are prone to occur in scar sites with large tension. Early treatment of high tension scar and scar ulcer is important in prevention, and surgery is the optimal treatment for Marjolin's ulcers. Regular follow-up should be carried out owning to recurrence rate in certain degree after surgery.

Objective: To study the expression levels of annexin A1 (ANXA1), GATA-3, and T-bet in T lymphocytes of peripheral blood in burned mice with sepsis at early stage, and to analyze their immune regulatory mechanisms., Methods: Seven-hundred and eighty male mice of clean grade were divided into sham injury group (n=60, sham injured on the back by immersing in 37 ℃ warm water for 10 s), burn group (n=240, inflicted with 20% TBSA deep partial- thickness burn on the back by immersing in 100 ℃ hot water for 10 s), sepsis group (n=240, intraperitoneally injected with 6 mg/kg lipopolysaccharide), and burn+ sepsis group (n=240) according to the random number table. Mice of burn+ sepsis group were treated as that in burn group at first, and then they were treated as that in sepsis group. (1) Immediately after injury, six mice in sham injury group were selected to collect lymphocyte suspension of peripheral blood (1 tube each mouse) according to the random number table. According to the random number table, 6 mice of each of the other three groups were respectively selected at post injury hour (PIH) 12, 24, 48, and 72 for the collection of lymphocyte suspension from peripheral blood (1 tube each mouse). Each tube of cell suspension was equally divided into two parts. Fluorescein isothiocyanate (FITC)-labeled human anti-mouse CD4 monoclonal antibody and phycoerythrin (PE)-labeled human anti-mouse interferon-γ monoclonal antibody were added to one part of cell suspension to mark helper T lymphocyte 1 (Th1). FITC-labeled human anti-mouse CD4 monoclonal antibody and PE-labeled human anti-mouse interleukin-4 (IL-4) monoclonal antibody were added to the other part of cell suspension to mark Th2. The percentages of Th1 and Th2 were determined with flow cytometer, and the ratio of Th1 to Th2 was calculated. (2) According to the random number table, 18 mice in sham injury group were selected immediately after injury for the collection of lymphocyte suspension of peripheral blood (1 tube each mouse), and 18 mice of each of the other 3 groups were respectively selected at PIH 12, 24, 48, and 72 to collect the lymphocyte suspension of peripheral blood (1 tube each mouse). The mRNA expression levels of ANXA1, GATA-3, and T-bet were determined by real-time fluorescent quantitative reverse transcription-PCR. (3) Immediately after injury, 36 mice in sham injury group were selected to collect lymphocyte suspension of peripheral blood (1 tube each mouse) according to the random number table, and then 36 tubes of cell suspension were divided into 6 batches (6 tubes each batch). Each one of 6 kinds of antibody combinations: antibodies for labeling Th1 and Th2 in combination with PE-anthocyanin 7 labeled human anti-mouse ANXA1 monoclonal antibody, PE-anthocyanin 7 labeled human anti-mouse GATA-3 monoclonal antibody, and PE-anthocyanin 7 labeled human anti-mouse T-bet monoclonal antibody was added to 1 tube of cell suspension at each batch. According to the random number table, 36 mice of each of the other 3 groups were respectively selected at PIH 12, 24, 48, and 72 for the collection of lymphocyte suspension of peripheral blood (1 tube each mouse), and then 36 tubes of cell suspension at each time point were divided into 6 batches for marking with 3 kinds of surface markers of Th1 and Th2 (6 tubes each batch). Each one of above-mentioned 6 kinds of antibodies was added to 1 tube of cell suspension at each time point for each batch. The percentages of ANXA1, GATA-3, and T-bet positive cells in Th1 and Th2 were determined with flow cytometer. Data were processed with one-way analysis of variance, analysis of variance of factorial design, and SNK test. The relationship between the percentages of ANXA1 positive cell and the percentages of GATA-3 positive cell in Th1 and Th2, and mRNA expression level of ANXA1 and mRNA expression level of GATA-3 in lymphocytes were assessed by linear correlation analysis., Results: (1) Compared with those in sham injury group immediately after injury, the percentages of Th1 and Th2 and the ratio of Th1 to Th2 of mice in burn group were significantly decreased from PIH 24 on, with P values below 0.05; the percentages of Th1 and Th2 and the ratios of Th1 to Th2 of mice in sepsis group and burn+ sepsis group were significantly decreased from PIH 12 on, with P values below 0.05. (2) Compared with those in sham injury group immediately after injury, the mRNA expression levels of ANXA1 and GATA-3 in lymphocyte of mice in burn group were significantly decreased from PIH 24 on, with P values below 0.05; the mRNA expression level of T-bet was significantly decreased at PIH 24 but significantly increased at PIH 48 and 72, with P values below 0.05. Compared with those in sham injury group immediately after injury, the mRNA expression levels of ANXA1 and GATA-3 in lymphocytes of mice in sepsis group were significantly decreased from PIH 12 on, and the mRNA expression level of T-bet was increased significantly from PIH 12 on, with P values below 0.05; the mRNA expression levels of ANXA1, GATA-3, and T-bet in lymphocytes of mice in burn+ sepsis group were significantly decreased from PIH 12 on, with P values below 0.05, reaching the nadir at PIH 72 (0.50±0.04, 0.45±0.03, 0.21±0.05, respectively). (3) A significant positive correlation was observed between ANXA1 mRNA expression level and GATA-3 mRNA expression level in lymphocytes of peripheral blood (r=0.862, P<0.05). (4) Compared with those in sham injury group immediately after injury, the percentages of ANXA1 and GATA-3 positive cellsin Th1 and Th2 of mice in burn group were significantly lowered from PIH 24 on, and the percentage of T-bet positive cells was significantly decreased at PIH 24, but it was increased from PIH 48 on, with P values below 0.05. The percentages of ANXA1 and GATA-3 positive cells in Th1 and Th2 of mice in sepsis group were continuously decreased from PIH 12 on, which were lower at most time points than those in sham injury group immediately after injury, with P values below 0.05. The percentages of T-bet positive cells in Th1 and Th2 of mice in sepsis group were significantly increased since PIH 12 as compared with those in sham injury group immediately after injury, with P values below 0.05. The percentages of ANXA1, GATA-3, and T-bet positive cells in Th1 and Th2 of mice in burn+ sepsis group were continuously lowered from PIH 12, with significantly statistical differences at most time points as compared with those in sham injury group immediately after injury, with P values below 0.05. (5) The percentages of GATA-3 positive cells in Th1 and Th2 were significantly positively correlated with those of ANXA1 (with r values respectively 0.747 and 0.787, P values below 0.05)., Conclusions: The expression levels of ANXA1, GATA-3, and T-bet were continuously lowered in burned mice with sepsis, and it may play an important role in Th1/Th2 balance switching to Th2 bias and immunosuppressive process.

Objective: To investigate the clinical efficacy of free latissimus dorsi musculocutaneous flaps in repairing large and deep skin and soft tissue defects around the knee joints., Methods: Twenty-five patients with large and deep skin and soft tissue defects around the knee joints were hospitalized from March 2005 to March 2014. The area of defects around the knee joints ranged from 10 cm × 8 cm to 43 cm × 23 cm. The free latissimus dorsi musculocutaneous flaps were used to repair the defects, with the area ranging from 12 cm × 10 cm to 45 cm × 25 cm. The thoracodorsal artery and its concomitant vein of the musculocutaneous flap were anastomosed to the descending branch of the lateral circumflex femoral artery and its concomitant vein respectively to reconstruct blood supply. Split-thickness skin grafts around the flap donor sites were harvested to cover the muscle surface of the musculocutaneous flaps. The flap donor sites were closed directly with suture, and the skin donor sites were healed by dressing change., Results: All the 25 flaps survived without vascular crisis. The flaps were in satisfactory appearance. The flap donor sites were healed with linear scar. All the patients were followed up for 3 to 6 months. At last, they were able to stand up and walk., Conclusions: The free latissimus dorsi musculocutaneous flap transplantation is an effective treatment for the repair of large and deep soft tissue defects around the knee joints, and the descending branch of lateral circumflex femoral artery and its concomitant vein are the appropriate recipient vessels.