The writing group of

formulated the consensus through three face-to-face national multi-disciplinary expert meetings, combining theoretical and practical experience, and drawing lessons from application of nitrous oxide and oxygen mixed inhalation for sedation and analgesia technology in other disciplines at home and abroad. The consensus provided detailed descriptions on the indications, contraindications, possible side effects and corresponding first aid measures, application process, operation conditions, and training of the technology in burn surgery, and formulated the relevant plans.

With the increase in various trauma patients and the number of surgeries and the worsening of population aging, more and more surgical site infection (SSI) and the resulting wounds were seen, bringing great pressure and burden to medical staff and patients. This article focuses on the risk factors, prevention, and treatment strategies related to SSI and the resulting wounds, especially their common treatments, hoping to raise the significant attention of everyone.

The iatrogenic wound is defined as infection, necrosis, or defect of the skin and deep soft tissue resulting from a medical procedure. At present, the main factors causing iatrogenic wounds include surgery, radiotherapy, interventional therapy, and drugs etc. Iatrogenic wounds are attributed to iatrogenic injuries that are in accordance with ethics, laws, and relevant regulations, and the degree of these injuries is within an acceptable range. Medical staff can reduce the incidence of iatrogenic wounds and the degree of injury by improving medical technology and responsibility in medical procedures. Iatrogenic wounds can be repaired and the patient's physical and mental health can be restored with targeted medical treatment. How to effectively prevent and treat iatrogenic wounds so as to minimize the degree of iatrogenic injuries to patients needs further exploration. To sum up, the purpose to publish this special topic in this issue is to arouse the peer's attention to the prevention and treatment of iatrogenic wounds.

Objective To explore the clinical treatment of incisional wound infection after orthopedic internal fixation for lower extremity joint injuries. Methods A retrospective cohort study was conducted. From February 2014 to December 2019, 214 patients with lower limb closed injury were treated in Beijing Jishuitan Hospital, including 143 males and 71 females, aged from 16 to 65 years. All patients underwent orthopedic internal fixation, after which incisional wound infection developed in 42 cases of postoperative wounds of patellar fracture, 30 cases of postoperative wounds of tibial plateau fracture, 72 cases of postoperative wounds of Achilles tendon rupture, 45 cases of postoperative wounds of calcaneal fracture, and 25 cases of postoperative wounds of Pilon fracture with 31 cases of superficial infection and 183 cases of deep infection. According to the postoperative evaluation of the incisional wounds, dressing change and/or thorough debridement (with wound area from 4 cm×3 cm to 11 cm×5 cm after debridement), and internal fixation treatment were performed. After thorough debridement, wounds were treated with continuous vacuum sealing drainage (VSD), and then direct suture+VSD or flap transplantation were performed according to the incision and its surrounding skin tissue, infection, suture tension, exposure of internal fixation or bone or Achilles tendon tissue. According to the wound site and injury, the flap types of retrograde anterolateral thigh perforator flap, medial sural artery perforator flap, gastrocnemius myocutaneous flap, sural neurovascular flap, peroneal brevis muscle flap, posterior tibial artery perforator flap, and free anterolateral thigh perforator flap could be selected. The donor site wound was closed by direct suture or grafted with split-thickness skin graft. The removal of internal fixation, wound repair method, type and size of flaps, survival of flaps, and wound healing were recorded. The recurrence of infection, appearance of donor and recipient areas, and recovery of lower limb joint function were followed up. Results All the internal fixations were removed in patients with postoperative wounds of patellar fracture, among whom 36 cases were repaired with retrograde anterolateral thigh perforator flap, and 6 cases were repaired with medial sural artery perforator flap. Among the patients with postoperative wounds of tibial plateau fracture, the internal fixation was completely retained in 18 cases, partially removed in 6 cases, and completely removed in 6 cases, while the wound was closed by direct suture in 8 cases, transplanted with gastrocnemius myocutaneous flap in 21 cases, and transplanted with medial sural artery perforator flap in 1 case. Among the patients with postoperative wounds of Achilles tendon rupture, the internal fixation was completely retained in 10 cases and completely removed in 62 cases, and the wound was closed by direct suture in 10 cases and transplanted with sural neurovascular flap in 62 cases. Among the patients with postoperative wounds of calcaneal fracture, the internal fixation was completely removed in 32 cases and completely retained in 13 cases, and the wound was healed by dressing change in 5 cases, closed by direct suture in 5 cases, transplanted with sural neurovascular flap in 23 cases, and transplanted with sural neurovascular flap combined with peroneal brevis muscle flap in 12 cases. Among the patients with postoperative wounds of Pilon fracture, the internal fixation was partially removed in 5 cases, completely retained in 17 cases, and completely removed in 3 cases; the wound was closed by direct suture in 4 cases, transplanted with posterior tibial artery perforator flap in 18 cases, and transplanted with free anterolateral thigh flap in 3 cases. The area of flaps/myocutaneous flaps ranged from 5 cm×3 cm to 18 cm×8 cm, and the area of muscle flaps were from 13.0 cm×1.5 cm to 15.0 cm×2.5 cm. All the wounds closed by direct suture healed. Blood flow obstacle occurred in the distal margin of sural neurovascular flap transplanted in 5 patients and posterior tibial artery perforator flap transplanted in one patient, which healed successfully after dressing change. The other flaps survived well, and the wounds were healed. The patients were followed up for 5 months to 5 years, and no recurrence of infection occurred. The direct suture of the flap donor site left linear scar, and the appearance of the skin graft was good. Three patients with tibial plateau fracture and 2 patients with Pilon fracture had limited joint movement, while the joint activity of the other patients was normal. The patients with Achilles tendon rupture and calcaneal fracture had normal ground motion. The sural neurovascular flap grafted on the wound after calcaneal fracture was bloated resulting in inconvenience in wearing shoes, the gastrocnemius myocutaneous flap grafted on the postoperative wound after tibial plateau fracture was bloated, whereas the appearance of the other flaps was good. Conclusions For incisional wound infection after orthopedic internal fixation for lower extremity joint injuries, the treatment should be classified according to wound infection and wound site. Dressing change, thorough debridement, reasonable disposal of internal fixation, direct suture after application of VSD, and flap covering, etc. not only ensure the infection control and the wound closure, but also restore the function of the lower limbs to the greatest extent, so as to maximize the benefit of the patient.

Objective To investigate the clinical effect of staged repair strategy for chronic sacrococcygeal radiation ulcer. Methods The retrospective cohort study method was applied. Twelve patients with chronic sacrococcygeal radiation ulcer were admitted to Beijing Jishuitan Hospital from January 2010 to June 2020, including 7 males and 5 females, aged 38-74 years. The thorough debridement was performed in the first stage, with wounds area after debridement ranging from 8 cm×6 cm to 22 cm×14 cm, and continuous vacuum sealing drainage (VSD) was performed after the debridement operation. In the second stage, personalized surgery scheme was formulated according to the patient's age, systemic condition, vascular condition, and the position, size, and depth of wound. Six cases were reconstructed with superior/inferior gluteal artery perforator flaps, 4 cases were repaired with gluteus maximus myocutaneous flaps, 1 case was repaired with pedicled latissimus dorsi myocutaneous flap, and 1 case was reconstructed with free transplantation of latissimus dorsi myocutaneous flap. The area of flaps or myocutaneous flaps ranged from 10 cm×8 cm to 25 cm×18 cm. Donor sites of the flaps were sutured primarily in 9 patients and in the other 3 patients were repaired with intermediate split-thickness skin graft in back. The survival of flap or myocutaneous flap after operation, recurrence of tumor, and the appearance and texture of flap or myocutaneous flap, and wound healing were observed during follow-up. Results Flaps or myocutaneous flaps in 11 patients survived after operation, and superior gluteal artery perforator flap in 1 patient had partial distal necrosis, which was covered again with flap pushed to the distal after debridement and resection of the necrotic tissue. The wounds in 8 patients achieved primary healing, 1 patient repaired with superior gluteal artery perforator flap experienced subcutaneous infection, 1 patient repaired with superior gluteal artery perforator flap suffered distal venous congestion of the flap, and 1 patient repaired with gluteus maximus myocutaneous flap had hematoma under myocutaneous flap, and 1 patient repaired with retrograde latissimus dorsi myocutaneous flap had incision exudation and dehiscence, which were all healed after dressing change, etc. There was no recurrence of tumor after the operation. The wounds healed well during follow-up of 2-52 months after discharge, with no recurrence of infection, and the flaps were soft in texture, with satisfactory appearance and well healed donor sites. Conclusions On the basis of thorough debridement and VSD in the first stage, superior/inferior gluteal artery perforator flap, gluteus maximus myocutaneous flap, or pedicled/free latissimus dorsi myocutaneous flap with abundant blood supply is applied to repair chronic sacrococcygeal radiation ulcer in the second stage. The staged operation is reliable, with minimal injury to the donor site of flap and satisfactory therapeutic effect.

Objective To explore the clinical effects of autologous skin paste in repairing medium-thickness skin donor site wounds. Methods The prospective randomized controlled research method was applied. From October 2018 to December 2019, 18 patients with flame burn or hydrothermal scald, conforming to the inclusion criteria were admitted to Jinhua Hospital Affiliated to Zhejiang University School of Medicine, including 15 males and 3 females, aged (45±6) years. The wounds were repaired with medium-thickness skin grafts from thigh, and the wound area was (121±33) cm² after medium-thickness skin grafting. The medium-thickness skin donor site wound in each patient was divided into 2 wounds in equal area and allocated into autologous skin paste group and conventional treatment group by flipping a coin, with 18 wounds in each group. The wounds in autologous skin paste group were repaired with skin paste prepared with remaining skin fragments after autologous medium-thickness skin grafting, and the wounds in conventional treatment group were covered with petroleum jelly gauze and fixed with sterile gauze. On 3, 7, 14, and 21 d after operation, the wound healing in 2 groups was observed, and the wound healing rate was calculated. The wound healing time in 2 groups was recorded. Occurrences of wound subcutaneous effusion and infection on 3, 7, 14, and 21 d after operation and wound ulceration in 3 months after operation were observed. In 6 months after operation, the Vancouver Scar Scale (VSS) was used to evaluate the scar formation of wounds in 2 groups. Data were statistically analyzed with analysis of variance for repeated measurement, chi-square test, and group

test. Results The wounds in 2 groups did not heal on 3 and 7 d after operation. The wound healing rate in autologous skin paste group was (29.8±2.5)% and (95.6±4.7)% on 14 and 21 d after operation, which were significantly higher than (25.8±2.9)% and (82.6±8.9)% in conventional treatment group (

=4.3, 5.6,

<0.01). The wound healing time in autologous skin paste group was (21.8±1.6) d, which was significantly shorter than (25.6±2.0) d in conventional treatment group (

=6.24,

<0.01). On 3, 7, 14, and 21 d after operation, there were no complications such as subcutaneous effusion or infection in wounds of 2 groups. In 3 months after operation, ulceration occurred in wounds of 2 patients in autologous skin paste group, which was significantly less than 12 patients in conventional treatment group (

²=11.688,

<0.01). The ulcerated wounds healed after dressing changes. In 6 months after operation, the VSS score of wounds in autologous skin paste group was (9.1±1.1) points, which was significantly lower than (11.3±1.2) points in conventional treatment group (

=-5.75,

<0.01). Conclusions The remaining skin fragments after autologous medium-thickness skin grafting prepared into skin paste to repair medium-thickness skin donor site wounds can shorten wound healing time, improve wound healing quality, and reduce degree of scar hyperplasia, with a good clinical effect.

Objective To explore the effects of stepwise acute pain management on acute pain and post-traumatic stress disorder (PTSD) in children with burns. Methods From November 2018 to December 2019, 196 children with burns who were admitted to West China Hospital of Sichuan University and met the inclusion criteria were enrolled in the prospective randomized controlled study. The children were divided into traditional pain management group (97 children, 51 males and 46 females, aged 1 to 6 years) and stepwise pain management group (96 children, 55 males and 41 females, aged 1 to 6 years) according to the random number table. Children in traditional pain management group were treated with traditional acute pain care, while the children in stepwise pain management group were treated with stepped acute pain management (moderate pain was treated with oral administration of acetaminophen sustained-release dry suspension at the dose of 10 to 15 mg/kg once every 4 to 6 hours, and severe pain was treated with morphine intravenous injection at the dose of 0.1 to 0.2 mg/kg once every 4 hours) on the basis of traditional acute pain care after admission. The COMFORT behavior scale was applied to compare the resting pain levels of children in the two groups within post injury day (PID) 3 (1, 9, and 17 o'clock each day). The adverse reactions of children in the stepwise pain management group during the treatment period were recorded. The occurrence of PTSD within one month after injury was evaluated in both groups by the revised PTSD scale. Data were statistically analyzed with independent sample

test, Bonferroni correction, analysis of variance for repeated measurement, chi-square test, Wilcoxon rank sum test, and Fisher's exact probability test. Results The pain scores of children in stepwise pain management group were significantly lower than traditional pain management group at 1, 9, and 17 o'clock on PID 1, 1, 9, and 17 o'clock on PID 2, and 1, 9, and 17 o'clock on PID 3 (

=2.71, 3.44, 4.05, 4.18, 4.08, 4.19, 4.25, 3.69, 3.71,

<0.05 or

<0.01). The pain scores of children in both groups showed a decreasing trend over time. Of the 96 children in stepwise pain management group, 84 children were treated with oral administration of acetaminophen sustained-release dry suspension, and 12 children were treated with morphine intravenous injection. No adverse reaction occurred during the treatment period. The incidence of PTSD of children in stepwise pain management group within 1 month after injury was 3.12% (3/96), which was significantly lower than 14.43% (14/97) in traditional pain management group,

<0.05. Conclusions The stepped acute pain management can relieve the acute pain and reduce the incidence of PTSD in children with burns.

Objective To investigate the influencing factors and their predictive value of skin graft survival after Meek grafting in severe burn patients. Methods A retrospective case-control study was conducted in 115 severe burn patients (95 males, 20 females, aged 1-74 years) who met the inclusion criteria and received Meek grafting in the First Affiliated Hospital of Army Medical University (the Third Military Medical University) from January 2013 to December 2019. The patients were divided into good skin graft survival group with skin graft survival rate≥70% (68 cases) and poor skin graft survival group with skin graft survival rate<70% (47 cases). The statistics of patients in the two groups were recorded during their first Meek grafting after admission including the gender, age, body mass index, full-thickness burn area, burn index, complication of inhalation injury, time from injury to operation, preoperative cystatin C level, preoperative albumin level, preoperative neutrophil, preoperative hemoglobin level, preoperative platelet count, and platelet count on the first, third, and fifth day after operation. The above indicators were statistically analyzed between the two groups with independent sample

test, Mann-Whitney

test, and chi-square test. A 1∶1 propensity score matching (PSM) of the gender, age, body mass index, full-thickness burn area, burn index, complication of inhalation injury, time from injury to operation of patients in the two groups were performed to eliminate the differences in baseline data, and then the above indicators of the remaining patients in the two groups were recorded and analyzed again. The indicators with statistically significant differences between the two groups after 1∶1 PSM were selected for multivariate logistic regression analysis to screen the independent risk factors affecting the skin graft survival after Meek grafting in severe burn patients. The receiver operating characteristic (ROC) curve of independent risk factors for predicting poor skin graft survival after Meek grafting in severe burn patients after 1∶1 PSM was drawn, and the area under the curve, the cut-off value, and the sensitivity and specificity under the cut-off value were calculated. The patients after 1∶1 PSM were divided into independent risk factor>the cut-off value group and independent risk factor≤the cut-off value group with the incidence of poor skin graft survival after Meek grafting compared using the chi-square test, and the relative risk of poor skin graft survival after Meek grafting was calculated. Results Before 1∶1 PSM, there were no statistically significant differences in gender, age, body mass index, complication of inhalation injury, time from injury to operation, preoperative cystatin C level, preoperative albumin level, preoperative neutrophil, preoperative hemoglobin level of patients between the two groups (

>0.05); the full-thickness burn area and burn index of patients in poor skin graft survival group were significantly higher than those in good skin graft survival group (

=-2.672, -2.882,

<0.01); the preoperative platelet count and the platelet count on the first, third, and fifth day after operation of patients in poor skin graft survival group were significantly lower than those in good skin graft survival group (

-3.411, -3.050, -2.748, -2.686

<0.01). After 1∶1 PSM, 46 cases were remained in each group. There were no statistically significant differences in gender, age, body mass index, full-thickness burn area, burn index, complication of inhalation injury, time from injury to operation, preoperative cystatin C level, preoperative albumin level, preoperative neutrophil, preoperative hemoglobin level of remaining patients between the two groups (

>0.05); the preoperative platelet count and the platelet count on the first, third, and fifth day after operation of patients in poor skin graft survival group were significantly lower than those in good skin graft survival group (

=-3.428, -2.940,

=-2.427, -2.316,

<0.05 or

<0.01). Multivariate logistic regression analysis showed that the preoperative platelet count was the only independent risk factor affecting the skin graft survival after Meek grafting in severe burn patients (odds ratio=0.994, 95% confidence interval=0.989-0.998,

<0.01). The area under the ROC curve of preoperative platelet count predicting poor skin graft survival after Meek grafting in 92 patients was 0.707 (95% confidence interval=0.603-0.798,

<0.01), and the cut-off value of preoperative platelet count was 98×10⁹/L, with sensitivity of 54.3% and specificity of 78.3% under the cut-off value. The incidence of poor skin survival after Meek grafting of patients in preoperative platelet count≤98×10⁹/L group was 71.4% (25/35), which was obviously higher than 36.8% (21/57) in preoperative platelet count>98×10⁹/L group (

²=10.376,

<0.01). compared="" with="" that="" in="" preoperative="" platelet="" count="">98×10⁹/L group, patients in preoperative platelet count≤98×10⁹/L group had a relative risk of poor skin graft survival after Meek grafting of 2.211 (95% confidence interval=1.263-3.870). Conclusions Preoperative platelet count is an independent risk factor affecting the skin graft survival after Meek grafting in severe burn patients and has a good predictive value. Meek grafting should be performed with caution when the preoperative platelet count of patients is≤98×10⁹/L.

Objective To explore the clinical effects of bilateral overlength anterolateral femoral perforator flaps connected in series or parallel in repairing large area of wounds in limbs. Methods From January 2017 to July 2019, 9 patients with large area of skin and soft tissue defects in limbs were admitted to the Departments of Hand Surgery and Foot and Ankle Surgery of Ruihua Affiliated Hospital of Soochow University, including 8 males and 1 female, aged 36 to 63 years. The retrospective cohort study was conducted. The wound areas of patients after debridement were 20 cm×15 cm to 30 cm×25 cm, and the wounds were repaired with bilateral overlength anterolateral femoral perforator flaps. One main artery defect in the receiving area of 4 patients was repaired with bilateral flaps connected in series. Two main artery defects in the receiving area of 5 patients were repaired with bilateral flaps connected in parallel. A total of 18 flaps were excised, and the area of a single flap ranged from 20 cm×8 cm to 46 cm×9 cm. The donor sites of 17 flaps were sutured directly, and the donor site of 1 flap was repaired with free full-thickness skin graft from hypogastrium. Harvesting time of flaps, survival condition of flaps after surgery, and wound healing time, and flap observation, two-point discrimination distance of flaps, functional recovery of joint and appearance of recipient site, and recovery of donor site during follow-up were recorded. Results In this group of 9 patients, the flap harvesting time was 1.0 to 4.5 hours, and all the 18 flaps survived. The wound healing time of recipient site was 18 to 72 days after flap transplantation. They were followed up for 6 to 34 months. The shape of the recipient site was satisfactory, with no deep tissue infection such as osteomyelitis. Four flaps in 2 patients were bloated and were thinned in 6 months after operation; 4 flaps in 2 patients had skin pigmentation on the edge of the flap; the flap of one patient was scalded but healed by dressing change, with patchy scar being observed during follow-up. The rest of the flaps were soft, elastic, and painless with good blood supply. All the flaps restored with protective sensation, with only one point in two-point discrimination. Only linear scars remained in the donor sites of 17 flaps. All the limbs had good blood supply in the distal end of donor sites, and no restriction occurred in range of motion of knee joint and quadriceps muscle strength. Conclusions The bilateral overlength anterolateral femoral perforator flaps connected in series or parallel have constant anatomy, reliable blood supply, and flexible combination. It is an ideal surgical method for repairing large area of skin and soft tissue defects in limbs at one time.

Objective To investigate the correlation of

superantigens and human ear keloid formation. Methods The retrospective case-control study method was used. The discarded keloid tissue was collected from 10 patients (9 females and 1 male, aged 19-59 years) with ear keloid after core excision of ear keloid, and the discarded normal skin tissue was collected from 3 female patients (aged 20-24 years) with pigmented nevus after operation, who were admitted to affiliated Hospital of Nantong University from June 2017 to March 2018. The exudation from ear keloid surface was collected for bacteria culture and identification. The keloid and normal skin tissue were collected to detect the protein expression of

enterotoxin A+enterotoxin B+toxic shock syndrome toxin-1 (TSST-1) by Western blotting, and the keloid was divided into superantigen positive group and superantigen negative group according to the protein expression of

enterotoxin A+enterotoxin B+TSST-1. The protein expressions of T cell receptor (TCR) V β of keloid in 2 groups were detected by Western blotting. Collagen fibers formation and inflammatory cells infiltration in keloid dermis of 2 groups were observed by Masson and hematoxylin eosin staining, respectively. Enzyme-linked immunosorbent assay method was used to detect expression of

enterotoxin A, enterotoxin B, and TSST-1 in keloids with superantigen positive. Data were statistically analyzed with paired sample

test. Results Bacteria were cultured from the exudation on ear keloid surface, hemolysis was observed around the dominant bacteria after being cultured for 24 hours, and the colony was white or golden yellow, which was identified as

. The protein expression of

enterotoxin A+enterotoxin B+TSST-1 of normal skin was negative in 3 patients, and the protein expression was 0.267±0.016. The protein expression of

enterotoxin A+enterotoxin B+TSST-1 of keloid was positive in 4 patients, with the protein expression of 0.472±0.016, which was included into superantigen positive group, and the protein expression of

enterotoxin A+enterotoxin B+TSST-1 of keloid was negative in 6 patients, with the protein expression of 0.255±0.004, which was included into superantigen negative group. The protein expression of

enterotoxin A+enterotoxin B+TSST-1 of keloid in superantigen positive group was obviously higher than that of keloid in superantigen negative group and that in normal skin (

=15.22, 8.63,

＜0.01). The protein expression of TCR Vβ in keloid of superantigen positive group was 0.389±0.023, which was significantly higher than 0.169±0.014 in superantigen negative group (

=8.62,

＜0.01). Masson staining showed that a large number of collagen fibers existed in dermis of keloid in 2 groups. HE staining showed that there were a small number of inflammatory cells infiltration around the blood vessels of keloid dermis in superantigen negative group and a large number of inflammatory cells infiltration around the blood vessels of keloid in superantigen positive group. Among the 4 patients with superantigen positive keloid,

enterotoxin A was positive in 2 patients,

enterotoxin B was positive in 2 patients, and among that

enterotoxin A and enterotoxin B were both positive in 1 patient, with no TSST-1 detected in any patient. Conclusions The superantigen secreted by

is one of the many causes of ear keloid, which may be related to the activation of keloid signal pathway by superantigen of

.

Objective To conduct a bibliometric and visual analysis of the current status and trends of international research on keloids. Methods The articles on keloid research from 2000 to 2020 in the core collection of

database were retrieved. The bibliometrics method was applied to analyze the number of articles published per year, journals and the first authors, countries and institutions, research fields, the annual citation frequency of cumulative published articles, highly cited articles, keywords. CiteSpace5.6.R2 software was applied to visually cluster keywords of the included articles, while VOSviewer1.6.13 software was applied to visually cluster keywords in titles and abstracts of the included articles in order to analyze research directions and development trends. Results A total of 2 693 keloid-related articles were retrieved. From 2000 to 2020, the number of keloid-related articles published every year showed a significant upward trend. Totally 777 journals published keloid-related articles, of which

published the most. Rei Ogawa published the largest number of keloid-related articles as the first author of 52 related articles. Keloid-related researches were conducted in a total of 98 countries, of which the United States published the largest number of related articles (613 articles), followed by China (524 articles) and Japan (107 articles). A total of 2 656 institutions conducted keloid-related research, and the institution with the largest number of related articles published was Shanghai Jiao Tong University of China (67 articles). According to the subject classification of the

database, the included articles involved 110 research fields, and the top three were dermatology, surgery, and medicine, research and experimental. The included articles were cited 47 746 times in total, and the citation frequency of cumulative published articles increased by year. The most frequently cited article (152 times) was published in 2011. There were a total of 45 571 keywords in the included literature. The top 5 keywords ranked according to the number of articles involved from high to low were keloid (588 articles), hypertrophic scar (385 articles), expression (198 articles), fibroblast (155 articles), and scar (133 articles). The keyword map visualized by CiteSpace5.6.R2 software further displayed that the research focused on the cause, performance, and composition of keloids. VOSviewer1.6.13 software analysis showed that the research direction of keloids was divided into two categories of clinical keloid management and keloid mechanism research, the initial research hotspots were mainly to explore the diagnosis and treatment of keloids from individual cases, with a preference for apparent research, while in the later stage, the focus was on the overall management of keloids, in which the mechanism research went to the molecular level. Conclusions At present, international research interest on keloids is showing an upward trend. Both foreign (the United States, etc.) and domestic research institutions are conducting in-depth explorations of keloids. With dermatology as the leader, the research trend is gradually shifting from observational research to molecular research.

Objective To observe the functional changes of skeletal muscle in severely burned rats, and to investigate the effects and possible mechanisms of Janus kinase/signal transducer and activator of transcription 3 (JAK/STAT3) pathway inhibitor in skeletal muscle function. Methods The experiment research method was applied. One hundred and twenty male Wistar rats of 8-week-old were divided into sham injury group, simple burn group, and burn+JAK/STAT3 inhibitor group according to the random number table, with 40 rats in each group. Rats in simple burn group and burn+JAK/STAT3 inhibitor group were inflicted with 50% total body surface area full-thickness scald on the back and abdomen, and rats in sham injury group were sham injured. Rats in burn+JAK/STAT3 inhibitor group were intraperitoneally injected with JAK/STAT3 inhibitor ruxolitinib. On post injury day (PID) 0 (immediately), 1, 4, 7, and 14, 8 rats in each group were used to measure the specific force generated by extensor digitorum longus in optimal length stimulated with pulse frequency of 20, 40, 60, 80, 100, 120, 140, and 160 Hz using a multichannel electrophysiological instrument, and specific force in fatigue period of extensor digitorum longus in optimal length stimulated with pulse frequency of 50 Hz for 0, 10, 20, 30, 60, 120, 180, 240, and 300 s. On PID 0, 1, 4, 7, and 14, carbonyl compound content of extensor digitorum longus was determined by ultraviolet spectrophotometry, and ATP content of extensor digitorum longus was determined by micrometry. Data were statistically analyzed with analysis of variance for repeated measurement, analysis of variance for factorial design, Bonferroni method, and

test. Results Compared with those of sham injury group, specific forces of extensor digitorum longus of rats in simple burn group were significantly decreased after being stimulated with all the pulse frequency on PID 0, 1, 7, and all the pulse frequency except for 20 Hz on PID 4, and pulse frequency of 20 and 40 Hz on PID 14 (

<0.05 or

<0.01). Compared with those of simple burn group, specific forces of extensor digitorum longus of rats in burn+JAK/STAT3 inhibitor group were significantly increased after being stimulated with all the pulse frequency except for 20 Hz on PID 1 and all the pulse frequency on PID 4, 7, and 14 (

<0.05 or

<0.01). Compared with those of sham injury group, specific forces of extensor digitorum longus of rats in simple burn group were significantly decreased in fatigue period at all the time points post injury and stimulation time points except for 240 s on PID 7 (

<0.05 or

<0.01). Compared with those of simple burn group, specific forces of extensor digitorum longus of rats in burn+JAK/STAT3 inhibitor group were obviously increased in fatigue period at all the stimulation time points except for 60 and 300 s on PID 1 and 240 s on PID 4, and all the stimulation time points on PID 7 and 14 (

<0.05 or

<0.01). The carbonyl compound content of extensor digitorum longus of rats in simple burn group on PID 0, 1, 4, 7, and 14 was (0.651±0.155), (0.739±0.194), (0.618±0.086), (0.813±0.162), (0.615±0.115) nmol/mg, which were obviously higher than (0.196±0.019), (0.156±0.004), (0.169±0.023) (0.156±0.027), (0.175±0.008) nmol/mg in sham injury group (

=7.219, 6.491, 10.938, 9.182, 11.589,

<0.01) and (0.538±0.069), (0.369±0.059), (0.273±0.061), (0.334±0.109), (0.318±0.101) nmol/mg in burn+JAK/STAT3 inhibitor group (

=2.446, 4.689, 8.355, 5.754, 6.097,

<0.05 or

<0.01). The ATP content in extensor digitorum longus of rats in simple burn group on PID 1, 4, 7, and 14 was obviously lower than that in sham injury group (

=7.159, 7.591, 7.473, 4.026,

<0.01) and burn+JAK/STAT3 inhibitor group (

=2.295, 2.575, 2.453, 2.997,

<0.05). Conclusions After severe burn, the specific force of extensor digitorum longus in rats decreased significantly after being stimulated with different pulse frequencies, and the extensor digitorum longus in rats was prone to fatigue. Blocking the JAK/STAT3 signaling pathway can reduce the oxidative stress of muscle protein and increase ATP content, thereby reducing the muscle strength decline caused by burn injury and improving the muscle strength decline during fatigue period.

Objective To investigate the effects and mechanism of eleutheroside E on the growth of human hypertrophic scar fibroblasts (Fbs). Methods The experimental research method was used. The hypertrophic scar tissue was collected from 6 patients with hypertrophic scar (1 male and 5 females, aged 20 to 51 (37±8) years) admitted to General Hospital of Northern Theater Command, from October 2018 to March 2019. The third to seventh passages of human hypertrophic scar Fbs were cultured for later experiments. Cells were divided into normal saline group, 100 μmol/L eleutheroside E group, 200 μmol/L eleutheroside E group, and 400 μmol/L eleutheroside E group, and normal saline, eleutheroside E at the final molarity of 100, 200, and 400 μmol/L were added to cells in the corresponding groups. Cells were collected and divided into small interfering RNA (siRNA)-negative control alone group, siRNA-thrombospondin 1 (THBS1) alone group, siRNA-negative control+ 400 μmol/L eleutheroside E group, and siRNA-THBS1+ 400 μmol/L eleutheroside E group. Cells in siRNA-negative control alone group and siRNA-negative control+ 400 μmol/L eleutheroside E group were transfected with siRNA-negative control, cells in siRNA-THBS1 alone group and siRNA-THBS1+ 400 μmol/L eleutheroside E group were transfected with siRNA-THBS1. At 24 h after transfection, cells in siRNA-negative control alone group and siRNA-THBS1 alone group were added with normal saline, and cells in siRNA-negative control+ 400 μmol/L eleutheroside E group and siRNA-THBS1+ 400 μmol/L eleutheroside E group were added with eleutheroside E at the final molarity of 400 μmol/L. At 0 (immediately), 12, 24, 36, and 48 h after treatment, the cell proliferation activity (expressed as absorbance value) was detected by thiazolyl blue assay. Cells were divided into normal saline group, 200 μmol/L eleutheroside E group, 400 μmol/L eleutheroside E group, siRNA-negative control alone group, siRNA-THBS1 alone group, siRNA-negative control+ 400 μmol/L eleutheroside E group, and siRNA-THBS1+ 400 μmol/L eleutheroside E group. The corresponding treatments in each group were the same as before. At 24 h after treatment, the apoptosis was observed by Hoechst 33258 staining. Cells were collected and divided into normal saline group, 100 μmol/L eleutheroside E group, 200 μmol/L eleutheroside E group, 400 μmol/L eleutheroside E group, siRNA-negative control alone group, siRNA-THBS1 alone group, siRNA-negative control+ 400 μmol/L eleutheroside E group, and siRNA-THBS1+ 400 μmol/L eleutheroside E group. The corresponding treatments in each group were the same as before. At 24 h after treatment, the THBS1 protein level of cells was detected by Western blotting. The number of sample in each group was all 3 at each time point. Data were statistically analyzed with analysis of variance for factorial design, one-way analysis of variance, independent sample

test, and Bonferroni correction. Results At 0 h after treatment, the absorbance values of cells in normal saline group, 100 μmol/L eleutheroside E group, 200 μmol/L eleutheroside E group, and 400 μmol/L eleutheroside E group were similar (

> 0.05). At 12, 24, 36, and 48 h after treatment, the absorbance values of cells in 100 μmol/L eleutheroside E group, 200 μmol/L eleutheroside E group, and 400 μmol/L eleutheroside E group were significantly lower than those of normal saline group (

= 7.64, 28.94, 13.69, 5.87, 6.96, 22.83, 14.75, 11.52, 21.09, 20.15, 29.52, 23.12,

< 0.05 or

< 0.01). At 0 h after treatment, the absorbance values of cells in siRNA-negative control alone group, siRNA-THBS1 alone group, siRNA-negative control+ 400 μmol/L eleutheroside E group, and siRNA-THBS1+ 400 μmol/L eleutheroside E group were similar (

> 0.05). At 12, 24, 36, and 48 h after treatment, the absorbance values of cells in siRNA-THBS1 alone group and siRNA-negative control+ 400 μmol/L eleutheroside E group were significantly lower than those in siRNA-negative control alone group (

= 7.14, 44.87, 20.67, 40.98, 9.26, 11.08, 15.33, 20.56,

< 0.05 or

< 0.01); the absorbance values of cells in siRNA-THBS1 alone group, siRNA-negative control+ 400 μmol/L eleutheroside E group, and siRNA-THBS1+ 400 μmol/L eleutheroside E group were similar (

> 0.05). Compared with that in normal saline group, the numbers of apoptotic cells in 200 μmol/L eleutheroside E group and 400 μmol/L eleutheroside E group were increased at 24 h after treatment. At 24 h after treatment, compared with that in siRNA-negative control alone group, the numbers of apoptotic cells in siRNA-THBS1 alone group and siRNA-negative control+ 400 μmol/L eleutheroside E group were increased, while the numbers of apoptotic cells in siRNA-THBS1 alone group, siRNA-negative control+ 400 μmol/L eleutheroside E group, and siRNA-THBS1+ 400 μmol/L eleutheroside E group were similar. At 24 h after treatment, the protein levels of THBS1 of cells in 100 μmol/L eleutheroside E group, 200 μmol/L eleutheroside E group, and 400 μmol/L eleutheroside E group (0.87±0.12, 0.38±0.07, 0.20±0.09) were significantly lower than 1.83±0.17 in normal saline group (

= 16.61, 16.17, 17.29,

< 0.01). At 24 h after treatment, the protein levels of THBS1 of cells in siRNA-THBS1 alone group and siRNA-negative control+ 400 μmol/L eleutheroside E group (0.61±0.07, 0.58±0.07) were significantly lower than 1.86±0.07 in siRNA-negative control alone group (

= 71.06, 83.80,

< 0.01), and the protein levels of THBS1 of cells siRNA-THBS1 alone group, siRNA-negative control+ 400 μmol/L eleutheroside E group, and siRNA-THBS1+ 400 μmol/L eleutheroside E group (0.63±0.11) were similar (

> 0.05). Conclusions Eleutheroside E can inhibit the growth of human hypertrophic scar Fbs by down-regulating the expression of THBS1.

Objective To investigate the feasibility of negative-pressure wound therapy (NPWT) in the treatment of uncomplicated cardiac pacemaker pocket infection. Methods From January 2013 to March 2020, 35 patients with uncomplicated cardiac pacemaker pocket infection were admitted to the Department of Cardiology of Peking University First Hospital, including 21 males and 14 females, aged 27 to 84 years. The retrospective cohort study was conducted. After a complete debridement followed by continuous NPWT (with negative pressure of -16.67 kPa), the pulse-generator was inserted into the new pocket between the musculus pectoralis major and pectoralis minor. Pressure drainage tube was put into the old pocket space. NPWT with the same mode was used again for 5 to 7 days after the wound was closed. The removed pocket tissue of patients was observed with hematoxylin-eosin staining. The wound healing on 10 to 12 days after the operation of pacemaker replacement was observed, and the recurrence of infection was observed during 6 to 42 months follow-up after operation. Results The fibrous sac wall was observed in pocket tissue of the patients, and the tissue was partially covered with stratified epithelium, with many chronic inflammatory cells infiltration. Multinucleated giant cell reaction was observed in the tissue of some patients. Ten to twelve days after the operation of pacemaker replacement, 35 patients had good wound healing, and sutures were removed. After 6 to 42 months follow-up after operation, 31 patients were cured with no recurrence of infection and the wounds were well-healed; 4 patients who had recurrent infection received whole system of pacemaker removal after the operation. Conclusions On the premise of complete debridement, NPWT is an alternative treatment for patients with uncomplicated cardiac pacemaker pocket infection.

Mechanical power is the power that the ventilator transmits to the respirator for lung ventilation. In recent years, some researchers have suggested that mechanical power may be a good indicator for assessing ventilator-induced lung injury in general, which can be used for guiding the best mechanical ventilation strategy. While introducing the definition and calculation method of mechanical power, this paper focuses on the association and potential mechanism of mechanical power with ventilator-induced lung injury, which aims to provide a new perspective and research direction for clinical understanding of ventilator-induced lung injury.

Wound healing is a complex and critical process, which includes three stages: inflammation, proliferation, and remodeling. The epidermal cells are precisely regulated in this process. On one hand, keratinocytes around the wound edge migrate and proliferate to form a new basement membrane to cover the wound. On the other hand, the epidermal stem cells are activated with the proliferation and differentiation being enhanced, and the terminal differentiation and apoptosis being inhibited; and together with keratinocytes, epidermal stem cells promote the process of re-epithelialization under the regulation of various factors. In the epidermis, there is a group of resident T cell subsets, dendritic epidermal lymphocytes (DETCs) that play a key role in protecting the function of epidermal tissue. DETCs are activated after recognizing unknown antigens, the activated DETCs secret cytokines such as insulin-like growth factor Ⅰ, keratinocyte growth factor-1/2, granulocyte-macrophage colony stimulating factor, interferon-γ, and transforming growth factor-β, which promote epidermal homeostasis and re-epithelialization by regulating the dynamic balance among keratinocytes migration, proliferation, and apoptosis, and the differentiation of epidermal stem cells around the wound edge. This article discusses the biological characteristics of DETCs and their roles in the maintenance of epidermal homeostasis and wound healing.