[Epidemiological characteristics and risk factors of sepsis development and death in patients with extremely severe burns]

Objective: To explore the epidemiological characteristics and risk factors of sepsis development and death in patients with extremely severe burns. Methods: A retrospective case series study was conducted. From January 2017 to December 2021, 135 patients with extremely severe burns who met the inclusion criteria were admitted to the Department of Burn and Wound Repair of the Second Affiliated Hospital of Zhejiang University School of Medicine, including 100 males and 35 females, aged 18-84 years. The incidence and diagnosis time of sepsis, the rate of positive microbial culture of blood samples (hereinafter referred to as positive blood culture), and the mortality rate of all patients, as well as the incidence of sepsis and the pathogen of infection in patients with positive blood culture were recorded (statistically analyzed with chi-square test or Fisher's exact probability test). According to the occurrence of sepsis, all patients were divided into sepsis group (58 cases) and non-sepsis group (77 cases), and the gender, age, body mass index, history of hypertension, history of diabetes, combination of inhalation injury, burn site, burn type, total burn area, and combined injury of patients were compared between the two groups. According to the outcome, all patients were divided into death group (37 cases) and survival group (98 cases), and the aforementioned data grouped according to sepsis as well as the stability of shock period and the combination of sepsis of patients were compared between the two groups. The aforementioned data between two groups were statistically analyzed with univariate analysis of independent sample t test, Wilcoxon rank-sum test, Mann-Whitney U test, chi-square test, or Fisher's exact probability test. Factors with P<0.1 were selected for multivariate logistic regression analysis to screen independent risk factors of sepsis and death in patients with extremely severe burns. Results: Among all patients, the incidence of sepsis was 42.96% (58/135), the diagnosis time of sepsis was 14 (7, 24) d after injury, the positive blood culture rate was 62.22% (84/135), and the mortality rate was 27.41% (37/135). The incidence of sepsis of patients with positive blood culture was 69.05% (58/84). The top 5 pathogenic bacteria in the detection rate of septic patients with positive blood culture were Acinetobacter baumannii, Klebsiella pneumoniae, Pseudomonas aeruginosa, Staphylococcus aureus, and Enterobacter cloacae, ranking from high to low, and the proportion of Acinetobacter baumannii infected was significantly higher than that of non-septic patients with positive blood culture (χ2=7.49, P<0.05). Compared with those in non-sepsis group, the proportion of combination of inhalation injury, the proportion of perineal burns, and the total burn area of patients in sepsis group increased significantly (with χ2 values of 11.08 and 17.47, respectively, Z=5.68, P<0.05), while the other indicators did not change significantly (P>0.05). Multivariate logistic regression analysis showed that combination of inhalation injury, total burn area ≥80% total body surface area (TBSA), and perineal burns were independent risk factors for patients with extremely severe burns developing sepsis (with odds ratios of 3.15, 7.24, and 3.24, respectively, with 95% confidence intervals of 1.07 to 9.29, 1.79 to 29.34, and 1.21 to 8.68, respectively, P<0.05). Compared with those in survival group, the proportion of combination of inhalation injury, the proportion of perineal burns, and the proportion of combination of sepsis (with χ2 values of 6.55, 11.64, and 22.26, respectively, P values all <0.05), total burn area (Z=4.25, P<0.05), and proportion of instability of shock period (P<0.05) of patients in death group all increased significantly, while the other indicators did not change significantly (P>0.05). Multivariate logistic regression analysis showed that the instability of shock period and combination of sepsis were independent risk factors for death of patients with extremely severe burns (with odds ratios of 4.87 and 3.45, respectively, with 95% confidence intervals of 1.21 to 19.57 and 1.28 to 9.33, respectively, P<0.05). Conclusions: Patients with extremely severe burns have a high incidence of sepsis and a high mortality rate. The peak period of sepsis onset is 2 weeks after injury, with Acinetobacter baumannii as the most prominent infectious pathogen. Combination of inhalation injury, total burn area ≥80% TBSA, and perineal burns are independent risk factors for extremely severe burn patients complicated with sepsis, and combination of sepsis and instability of shock period are independent risk factors for death of patients with extremely severe burns.

[Advances on the application of physical airway clearance techniques in the treatment of inhalation injury]

Although the treatment of patients with burns combined with inhalation injury has achieved great success, from the perspective of epidemiology, inhalation injury is still the most common cause of death in mass burns. Such patients often suffered burns of large total body surface area, which is difficult to treat, with airway management as one of the core links. Physical airway clearance technique (ACT) acts on a patient's respiratory system by physical means, to discharge secretions and foreign bodies in the airway, achieve airway clearance, and improve gas exchange. In addition, the technique can prevent or alleviate many complications, thereby improving the clinical outcome of patients with inhalation injury. This article reviews the application of physical ACT in the field of inhalation injury, and to provide decision-making basis for clinical medical staff to choose physical ACT corresponding to the patient's condition.

[Effects of three-dimensional bioprinting antibacterial hydrogel on full-thickness skin defect wounds in rats]

Objective: To explore the effects of three-dimensional (3D) bioprinting gelatin methacrylamide (GelMA) hydrogel loaded with nano silver on full-thickness skin defect wounds in rats. Methods: The experimental research method was adopted. The morphology, particle diameter, and distribution of silver nanoparticles in nano silver solution with different mass concentrations and the pore structure of silver-containing GelMA hydrogel with different final mass fractions of GelMA were observed by scanning electron microscope and the pore size was calculated. On treatment day 1, 3, 7, and 14, the concentration of nano silver released from the hydrogel containing GelMA with final mass fraction of 15% and nano silver with final mass concentration of 10 mg/L was detected by mass spectrometer. At 24 h of culture, the diameters of inhibition zone of GelMA hydrogel containing final mass concentration of 0 (no nano silver), 25, 50, and 100 mg/L nano silver against Staphylococcus aureus and Escherichia coli were detected. Fibroblasts (Fbs) and adipose stem cells (ASCs) were isolated respectively by enzymatic digestion using the discarded prepuce after circumcision from a 5-year-old healthy boy who was treated in the Department of Urology of the Second Affiliated Hospital of Zhejiang University School of Medicine in July 2020, and the discarded fat tissue after liposuction from a 23-year-old healthy woman who was treated in the Department of Plastic Surgery of the Hospital in July 2020. The Fbs were divided into blank control group (culture medium only), 2 mg/L nano sliver group, 5 mg/L nano sliver group, 10 mg/L nano sliver group, 25 mg/L nano sliver group, and 50 mg/L nano sliver group, which were added with the corresponding final mass concentrations of nano sliver solution, respectively. At 48 h of culture, the Fb proliferation viability was detected by cell counting kit 8 method. The Fbs were divided into 0 mg/L silver-containing GelMA hydrogel group, 10 mg/L silver-containing GelMA hydrogel group, 50 mg/L silver-containing GelMA hydrogel group, and 100 mg/L silver-containing GelMA hydrogel group and then were correspondingly treated. On culture day 1, 3, and 7, the Fb proliferation viability was detected as before. The ASCs were mixed into GelMA hydrogel and divided into 3D bioprinting group and non-printing group. On culture day 1, 3, and 7, the ASC proliferation viability was detected as before and cell growth was observed by live/dead cell fluorescence staining. The sample numbers in the above experiments were all 3. Four full-thickness skin defect wounds were produced on the back of 18 male Sprague-Dawley rats aged 4 to 6 weeks. The wounds were divided into hydrogel alone group, hydrogel/nano sliver group, hydrogel scaffold/nano sliver group, and hydrogel scaffold/nano sliver/ASC group, and transplanted with the corresponding scaffolds, respectively. On post injury day (PID) 4, 7, 14, and 21, the wound healing was observed and the wound healing rate was calculated (n=6). On PID 7 and 14, histopathological changes of wounds were observed by hematoxylin eosin staining (n=6). On PID 21, collagen deposition of wounds was observed by Masson staining (n=3). Data were statistically analyzed with one-way analysis of variance, analysis of variance for repeated measurement, Bonferroni correction, and independent sample t test. Results: The sliver nano particles in nano silver solution with different mass concentrations were all round, in scattered distribution and uniform in size. The silver-containing GelMA hydrogels with different final mass fractions of GelMA all showed pore structures of different sizes and interconnections. The pore size of silver-containing GelMA hydrogel with 10% final mass fraction was significantly larger than that of silver-containing GelMA hydrogels with 15% and 20% final mass fractions (with P values both below 0.05). On treatment day 1, 3, and 7, the concentration of nano silver released from silver-containing GelMA hydrogel in vitro showed a relatively flat trend. On treatment day 14, the concentration of released nano silver in vitro increased rapidly. At 24 h of culture, the diameters of inhibition zone of GelMA hydrogel containing 0, 25, 50, and 100 mg/L nano silver against Staphylococcus aureus and Escherichia coli were 0, 0, 0.7, and 2.1 mm and 0, 1.4, 3.2, and 3.3 mm, respectively. At 48 h of culture, the proliferation activity of Fbs in 2 mg/L nano silver group and 5 mg/L nano silver group was both significantly higher than that in blank control group (P<0.05), and the proliferation activity of Fbs in 10 mg/L nano silver group, 25 mg/L nano silver group, and 50 mg/L nano silver group was all significantly lower than that in blank control group (P<0.05). Compared with the that of Fbs in 0 mg/L silver-containing GelMA hydrogel group, the proliferation activity of Fbs in 50 mg/L silver-containing GelMA hydrogel group and 100 mg/L silver-containing GelMA hydrogel group was all significantly decreased on culture day 1 (P<0.05); the proliferation activity of Fbs in 50 mg/L silver-containing GelMA hydrogel group was significantly increased (P<0.05), while the proliferation activity of Fbs in 100 mg/L silver-containing GelMA hydrogel group was significantly decreased on culture day 3 (P<0.05); the proliferation activity of Fbs in 100 mg/L silver-containing GelMA hydrogel group was significantly decreased on culture day 7 (P<0.05). The proliferation activity of ASCs in 3D bioprinting group show no statistically significant differences to that in non-printing group on culture day 1 (P>0.05). The proliferation activity of ASCs in 3D bioprinting group was significantly higher than that in non-printing group on culture day 3 and 7 (with t values of 21.50 and 12.95, respectively, P<0.05). On culture day 1, the number of dead ASCs in 3D bioprinting group was slightly more than that in non-printing group. On culture day 3 and 5, the majority of ASCs in 3D bioprinting group and non-printing group were living cells. On PID 4, the wounds of rats in hydrogel alone group and hydrogel/nano sliver group had more exudation, and the wounds of rats in hydrogel scaffold/nano sliver group and hydrogel scaffold/nano sliver/ASC group were dry without obvious signs of infection. On PID 7, there was still a small amount of exudation on the wounds of rats in hydrogel alone group and hydrogel/nano sliver group, while the wounds of rats in hydrogel scaffold/nano sliver group and hydrogel scaffold/nano sliver/ASC group were dry and scabbed. On PID 14, the hydrogels on the wound surface of rats in the four groups all fell off. On PID 21, a small area of wounds remained unhealed in hydrogel alone group. On PID 4 and 7, the wound healing rates of rats in hydrogel scaffold/nano sliver/ASC group were significantly higher than those of the other three groups (P<0.05). On PID 14, the wound healing rate of rats in hydrogel scaffold/nano sliver/ASC group was significantly higher than the wound healing rates in hydrogel alone group and hydrogel/nano sliver group (all P<0.05). On PID 21, the wound healing rate of rats in hydrogel alone group was significantly lower than that in hydrogel scaffold/nano sliver/ASC group (P<0.05). On PID 7, the hydrogels on the wound surface of rats in the four groups remained in place; on PID 14, the hydrogel in hydrogel alone group was separated from the wounds of rats, while some hydrogels still existed in the new tissue of the wounds of rats in the other three groups. On PID 21, the collagen arrangement in the wounds of rats in hydrogel alone group was out of order, while the collagen arrangement in the wounds of rats in hydrogel/nano sliver group, and hydrogel scaffold/nano sliver/ASC group was relatively orderly. Conclusions: Silver-containing GelMA hydrogel has good biocompatibility and antibacterial properties. Its three-dimensional bioprinted double-layer structure can better integrate with new formed tissue in the full-thickness skin defect wounds in rats and promote wound healing.

[A brief discussion on precision nutrition support for severe burn patients from theory to practice]

Severe burns can lead to sustained hypermetabolism in the body, resulting in delayed wound healing, and malnutrition, dysfunction, and even death of patients. It is critical to carry out adequate nutritional risk assessment and provide individualized nutritional support to improve the prognosis of patients with severe burns. This paper describes and summarizes precision nutrition support for severe burn patients from theory to clinical practice.

[Effect of sedation on resting energy expenditure in patients with extremely severe burns and the choice of energy estimation formula]

Objective: To investigate the effect of sedation on resting energy expenditure (REE) in patients with extremely severe burns and the choice of REE estimation formula during the treatment. Methods: A retrospective non-randomized controlled clinical study was conducted. From April 2020 to April 2022, 21 patients with extremely severe burns who met the inclusion criteria and underwent mechanical ventilation treatment were admitted to the Department of Burn and Wound Repair of Second Affiliated Hospital of Zhejiang University School of Medicine, including 16 males and 5 females, aged 60 (50, 69) years. Early anti-shock therapy, debridement, skin transplantation, nutritional support, and other conventional treatments were applied to all patients. Patients were sedated when they had obvious agitation or a tendency to extubate, which might lead to aggravation of the disease. REE measurement was performed on patients using indirect calorimetry on post-injury day 3, 5, 7, 9, 11, 14 and every 7 days thereafter until the patient died or being successfully weaned from ventilator. Totally 99 times of measurements were carried out, of which 58 times were measured in the sedated state of patients, and 41 times were measured in the non-sedated state of patients. The age, weight, body surface area, residual wound area, post-injury days of patients were recorded on the day when REE was measured (hereinafter briefly referred to as the measurement day). The REE on the measurement day was calculated with intensive care unit conventional REE estimation formula Thumb formula and special REE estimation formulas for burns including the Third Military Medical University formula, the Peng Xi team's linear formula, Hangang formula. The differences between the sedated state and the non-sedated state in the clinical materials, measured and formula calculated values of REE of patients on the measurement day were compared by Mann-Whitney U test and independent sample t test. The differences between the REE formula calculated values and the REE measured value (reflecting the overall consistency) in the sedated state were compared by Wilcoxon signed rank-sum test. The Bland-Altman method was used to assess the individual consistency between the REE formula calculated value and the REE measured value in the sedated state, and to calculate the proportion of the REE formula calculated value within the range of ±10% of the REE measured value (hereinafter referred to as the accuracy rate). Root mean square error (RMSE) was used to evaluate the accuracy of the REE formula calculated value relative to the REE measured value. Results: Compared with those in the non-sedated state, there was no statistically significant change in patient's age or post-injury days on the measurement day in the sedated state (P>0.05), but the weight was heavier (Z=-3.58, P<0.01), and both the body surface area and the residual wound area were larger (with Z values of -2.99 and -4.52, respectively, P<0.01). Between the sedated state and the non-sedated state, the REE measured values of patients were similar (P>0.05). Compared with those in the non-sedated state, the REE values of patients calculated by Thumb formula, the Third Military Medical University formula, the Peng Xi team's linear formula, and Hangang formula on the measurement day in the sedated state were significantly increased (with Z values of -3.58 and -5.70, t values of -3.58 and -2.74, respectively, P<0.01). In the sedated state, compared with the REE measured value, there were statistically significant changes in REE values of patients calculated by Thumb formula, the Third Military Medical University formula, and Hangang formula on the measurement day (with Z values of -2.13, -5.67, and -3.09, respectively, P<0.05 or P<0.01), while the REE value of patients calculated by the Peng Xi team's linear formula on the measurement day did not change significantly(P>0.05). The analysis of the Bland-Altman method showed that in the sedated state, compared with the REE measured value, the individual consistency of the calculated value of each formula was good; Thumb formula and Hangang formula significantly underestimated the patients' REE value (with the average value of the difference between the formula calculated value and the measured value of -1 463 and -1 717 kJ/d, the 95% confidence interval of -2 491 to -434 and -2 744 to -687 kJ/d, respectively), but the individual differences were small; the Third Military Medical University formula significantly overestimated the patients' REE value (with the average value of the difference between the formula calculated value and the measured value of 3 530 kJ/d, the 95% confidence interval of 2 521 to 4 539 kJ/d), but the individual difference was small; the Peng Xi team's linear formula did not significantly overestimate the patients' REE value (with the average value of the difference between the formula calculated value and the measured value of 294 kJ/d, the 95% confidence interval of -907 to 1 496 kJ/d), while the difference standard deviation was 4 568 kJ/d, which showed a large individual difference. In the sedated state, relative to the REE measured value, the accuracy rates of REE values calculated by Thumb formula, the Third Military Medical University formula, the Peng Xi team's linear formula, and Hangang formula were 25.9% (15/58), 15.5% (9/58), 10.3% (6/58), and 15.5% (9/58), respectively, and RMSE values were 4 143.6, 5 189.1, 4 538.6, and 4 239.8 kJ/d, respectively. Conclusions: Sedative therapy leads to a significant decrease in REE in patients with extremely severe burns undergoing mechanical ventilation treatment. When REE cannot be regularly monitored by indirect calorimetry to determine nutritional support regimens, patients with extremely severe burns undergoing sedation may be prioritized to estimate REE using Thumb formula.

[Research advances on biomaterials for the delivery of growth factors to regulate wound repair]

Wound repair is a highly coordinated and mutually regulated complex process involving various kinds of cells, extracellular matrices and cytokines. A variety of growth factors play an important regulatory role in wound healing, and it is critical to achieve effective delivery and sustained function of growth factors. In recent years, the application of biomaterials in tissue engineering has shown great potential, and the effective delivery of growth factors by biomaterials has attracted increasing attention. Based on this, this paper introduces the mechanism of related growth factors in the process of wound healing, focusing on the recent progress of biomaterial delivery of growth factors to accelerate wound healing, in order to provide new enlightenment for clinical wound treatment.

[A case of chronic refractory wound in the abdomen caused by residual foreign body]

A 59-year-old male patient with local sinus tract formation due to residual foreign body was admitted to the Second Affiliated Hospital of Zhejiang University College of Medicine on December 17, 2018. The examination showed that the residual foreign body was the component of a sticky cloth implanted when the patient underwent appendectomy 27 years ago. Hypertrophic scar developed at the right-lower abdominal incision for appendectomy 23 years ago and the secondary infection after cicatrectomy resulted in non-healing of the wound. The chronic refractory wound healed completely after surgical treatment in our hospital after this admission. The postoperative pathological examination revealed local inflammatory granuloma. This case suggests that chronic refractory wound is likely to form when secondary infection occurs following the surgical procedure near the implant, and aggressive surgery is an effective way to solve this problem.

[Application effects of feedforward control theory in the rollover bed treatment of mass patients with burn-explosion combined injury]

Objective: To explore the application effects of feedforward control theory in the rollover bed treatment of mass patients with burn-explosion combined injury. Methods: A retrospective observational research was conducted. From June 13 to 14, 2020, 15 patients with severe burn-explosion combined injury caused by liquefied natural gas tank car explosion and conforming to the inclusion criteria were admitted to the Second Affiliated Hospital of Zhejiang University School of Medicine. There were 13 males and 2 females, aged 33-92 (66±17) years. All the patients were treated with rollover bed from 48 h post admission, and the feedforward control theory was introduced, including establishing a special feedforward control management team for rollover bed, clarifying the duties of the medical staff in the rollover bed treatment of patients, implementing the cooperation strategy of multidisciplinary physician, training and examining for 80 nurses in the temporarily organized nurse team in the form of "rollover bed workshop", and formulating the checklist and valuation list of rollover bed treatment for continuous quality control. The frequency and the total number of turning over, and successful rate of one-time posture change with the rollover bed of patients within 30 days of admission were recorded, the occurrences of adverse events caused by improper operation for the rollover bed during the treatment were observed, including respiratory and cardiac arrests, treatment interruption, unplanned extubation, bed falling, and skin graft displacement. The lowest levels of arterial partial pressure of oxygen (PaO2) and arterial partial pressure of carbon dioxide (PaCO2), the number of patients with oxygenation index>300 mmHg (1 mmHg=0.133 kPa), and the occurrence of acute respiratory distress syndrome (ARDS) of patients within 2 days of admission and on the 30th day of admission were recorded. Results: Within 30 days of admission, the patients were turned over with the rollover bed for 2 to 6 times each day, with a total of 1 320 turning over operations, the successful rate of one-time posture change reached 99.9% (1 319/1 320), and no adverse event occurred. Within 2 days of admission, the lowest levels of PaO2 and PaCO2 of the patients were (100±19) and (42±4) mmHg, respectively, and the number of patients with mild, moderate, and severe ARDS were 10, 2, and 3, respectively, and none of the patients had oxygenation index>300 mmHg. On the 30th day of admission, the lowest levels of PaO2 and PaCO2 of the patients were (135±28) and (37±8) mmHg, respectively, 3 patients developed moderate ARDS, 1 patient developed severe ARDS, and 11 patients had oxygenation index>300 mmHg. Conclusions: The introduction of feedforward control theory in the treatment of rollover bed of mass patients with burn-explosion combined injury can ensure safe and successful completion of turning over with the rollover bed, promote the repair of burn wound, and improve respiratory function, and therefore improve the treatment quality of patients.

[The role of first-aid network construction in the early treatment of patients with critically severe hydrofluoric acid burns]

Objective: To explore the role of first-aid network construction in the early treatment of patients with critically severe hydrofluoric acid burns. Methods: Twenty-seven fluorine chemical enterprises distributed in Zhejiang province, Jiangxi Province, Fujian Province, and Inner Mongolia Autonomous Region and 22 hospitals with burn/plastic department or professional burn treatment group in Zhejiang province, including Zhejiang Quhua Hospital, and 5 hospitals outside Zhejiang province were involved in the first-aid network construction as member units. As the main unit, Zhejiang Quhua Hospital was responsible for the daily maintenance and technical guidance of the first-aid network. Zhejiang Quhua Hospital was assigned as the designated emergency hospital for 20 fluorine chemical enterprises, a near emergency hospital to the other 7 fluorine chemical enterprises was assigned as the designated hospital for them. Medical records of 56 patients (all males) with critically severe hydrofluoric acid burns who admitted to 5 first-aid network hospitals from January 2006 to June 2021, meeting the inclusion criteria, were involved in the retrospective cohort study. Based on whether the enterprise belonging to the first-aid network construction or not, the patients were divided into first-aid network group (27 cases, aged (41±9) years) and non first-aid network group (29 cases, aged (42±10) years). After the patients in the first-aid network group were injured, the enterprises and hospitals linked up immediately. The hospital where the patient was treated mobilize the treatment force, equipment, materials, and drugs in advance by the first-aid network, thereby realizing seamless joint between pre-hospital first-aid and in-hospital treatment. The hospital started the first-aid process and temporarily mobilized the rescue forces, equipment, materials, and drug after patients in non first-aid network group arrived at the department of emergency of the hospital. The time from injury to medical service, the first detection time of serum calcium, the time staying in department of emergency, the duration of hypocalcemia and hypomagnesemia, and the treatment outcome of patients in the two groups were recorded. Data were statistically analyzed with chi-square test, Fisher's exact probability test, independent-sample t test, and Wilcoxon rank-sum test. Results: The time from injury to medical service, the first detection time of serum calcium, and the time staying in department of emergency of patients in first-aid network group were 40.0 (30.0, 55.0), 23.0 (17.5, 37.5), and 42.0 (37.0, 53.0) min, which were significantly shorter than 180.0 (120.0, 240.0), 31.0 (22.5, 47.5), 61.0 (52.0, 65.5) min in non first-aid network group (Z=-6.17, -1.98, -4.15, P<0.05 or P<0.01). The duration of hypocalcemia and hypo- magnesemia of patients in first-aid network group were 1.2 (1.1, 1.6) and 1.9 (1.7, 2.1) h, which were significantly shorter than 4.6 (3.1, 6.2) and 3.2 (2.5, 4.6) h in non first-aid network group (Z=-5.80, -4.81, P<0.01). Three patients (11.1%) in first-aid network group died, among whom 2 patients died at 40 min after injury and 1 patient died 9.0 h after injury. Four patients (13.8%) died in non first-aid network group at 3.0, 3.0, 4.5, and 7.0 h after injury, respectively. The mortality rates of patients in the two groups were similar (P>0.05). Conclusions: Critically severe hydrofluoric acid burn is an extremely urgent situation encountered in clinical practice. The construction of a first-aid network creates condition for on-site treatment of patients and improves the first-aid efficiency, thereby gaining time to save lives.

[Effect and mechanism of astaxanthin on acute kidney injury in rats with full-thickness burns]

Objective: To explore the effect and mechanism of astaxanthin on acute kidney injury in rats with full-thickness burns. Methods: Forty-eight male Sprague Dawley rats of 8 to 10 weeks were divided into sham injury group, simple burn group, burn+ vehicle group, burn+ low-dose astaxanthin group, burn+ medium-dose astaxanthin group, and burn+ high-dose astaxanthin group according to the random number table, with 8 rats in each group. The back skin of rats in sham injury group were immersed in warm water of 20 ℃ for 15 s to simulate burn injury, and the back skin of rats in the other 5 groups were immersed in boiled water of 100 ℃ for 15 s to inflict full-thickness burn of 30% total body surface area. Fluid resuscitation was performed in rats in the 5 groups except of sham injury group immediately and 6 h after injury. At 30 min after injury, the rats in sham injury group and simple burn group were injected with 1 mL/kg normal saline via tail vein, rats in burn+ vehicle group were injected with 1 mL/kg astaxanthin solvent via tail vein, and rats in burn+ low-dose astaxanthin group, burn+ medium-dose astaxanthin group, and burn+ high-dose astaxanthin group were respectively injected with 5, 10, 20 mg/kg astaxanthin solution of 5, 10, 20 mg/mL via tail vein. The renal tissue was collected at post injury hour (PIH) 48, and hematoxylin eosin staining was used for histopathological observation and renal tubular injury score. At PIH 48, the venous blood was collected for detecting serum creatinine level through blood biochemical analyzer, and blood urea nitrogen (BUN) level was detected by enzyme-linked immunosorbent assay. The renal tissue was collected to detect the mRNA expressions of myeloperoxidase (MPO), interleukin-1β (IL-1β), and IL-6 by real-time fluorescent quantitative reverse transcription polymerase chain reaction method, and the protein expressions of Toll like receptor 4 (TLR4), phosphorylated nuclear factor kappa B (p-NF-кB) p65, and heme oxygenase 1 (HO-1) were detected by Western blotting. Besides, the expression of HO-1 in renal tissue was detected by immunofluorescence method. Data were statistically analyzed with Kruskal-Wallis H test, Dunn-Sidák correction, one-way analysis of variance, and Bonferroni method. Results: (1) At PIH 48, there were no inflammatory cell infiltrating and degeneration or necrosis of cells in renal tissue of rats in sham injury group, and the structure of renal tubules was intact. The renal tubules of burn rats in each group showed injury manifestation of separation between epithelial cell and basement membrane, and vacuole cells and lysate protein aggregation. The injury degree of renal tissue of rats in burn+ high-dose astaxanthin group was obviously decreased compared with that in simple burn group. (2) At PIH 48, compared with that of sham injury group, the renal tubular damage scores of rats in simple burn group, burn+ vehicle group, burn+ low-dose astaxanthin group, and burn+ medium-dose astaxanthin group were significantly increased (P<0.05 or P<0.01). Compared with those of simple burn group and burn+ vehicle group, the renal tubular damage scores of rats in burn+ medium-dose astaxanthin group and burn+ high-dose astaxanthin group were significantly decreased (P<0.05 or P<0.01). Compared with that of burn+ low-dose astaxanthin group, the renal tubular damage score of rats in burn+ high-dose astaxanthin group was significantly decreased (P<0.01). (3) At PIH 48, the level of serum creatinine of rats in sham injury group was (2.42±0.06) mg/L, which was significantly lower than (6.11±0.11), (6.48±0.08), (5.79±0.09), (4.03±0.12) mg/L of simple burn group, burn+ vehicle group, burn+ low-dose astaxanthin group, and burn+ medium-dose astaxanthin group (P<0.05 or P<0.01). The level of BUN of rats was (21.9±1.3) mmol/L in sham injury group, significantly lower than (32.1±7.4) mmol/L of simple burn group and (30.2±4.8) mmol/L of burn+ vehicle group (P<0.05 or P<0.01). At PIH 48, compared with those of simple burn group and burn+ vehicle group, the levels of serum creatinine and BUN of (16.0±2.9) mmol/L in burn+ medium-dose astaxanthin group, serum creatinine of (3.02±0.08) mg/L and BUN of (14.5±2.9) mmol/L in burn+ high-dose astaxanthin group, and serum creatinine of (22.8±5.5) mmol/L of rats in burn+ low-dose astaxanthin group were significantly decreased (P<0.05 or P<0.01). At PIH 48, compared with those of burn+ low-dose astaxanthin group, the levels of serum creatinine and BUN of burn+ high-dose astaxanthin group and serum creatinine of burn+ medium-dose group were obviously decreased (P<0.05 or P< 0.01). (4) At PIH 48, compared with those of sham injury group, the mRNA expressions of MPO, IL-1β, and IL-6 in renal tissue of rats in simple burn group, burn+ vehicle group, burn+ low-dose astaxanthin group, and burn+ medium dose astaxanthin group, and the mRNA expressions of IL-1β and IL-6 in renal tissue of rats in burn+ high-dose astaxanthin group were obviously increased (P<0.01). Compared with those of simple burn group and burn+ vehicle group, the mRNA expressions of MPO, IL-1β, and IL-6 in renal tissue of rats were significantly decreased in burn+ low-dose astaxanthin group, burn+ medium-dose astaxanthin group, and burn+ high-dose astaxanthin group (P<0.01). Compared with those of burn+ low-dose astaxanthin group, the mRNA expressions of MPO, IL-1β, and IL-6 in renal tissue of rats were significantly decreased in burn+ medium-dose astaxanthin group and burn+ high-dose astaxanthin group (P<0.01). The mRNA expressions of MPO, IL-1β, and IL-6 in renal tissue of rats in burn+ high-dose astaxanthin group were significantly decreased compared with those of burn+ medium-dose astaxanthin group (P<0.01). (5) At PIH 48 h, compared with those of sham injury group, the protein expressions of TLR4 and p-NF-кB p65 in renal tissue of rats in simple burn group, burn+ vehicle group, burn+ low-dose astaxanthin group, and burn+ high-dose astaxanthin group were obviously increased (P<0.01). Compared with those of simple burn group, the protein expressions of TLR4 and p-NF-кB p65 in renal tissue of rats in burn+ low-dose astaxanthin group, burn+ medium dose astaxanthin group, and burn+ high-dose astaxanthin group were significantly decreased (P<0.01). (6) The results of Western blotting combined with immunofluorescence method showed that compared with that of sham injury group, the protein expression of HO-1 in renal tissue of rats in burn+ vehicle group, burn+ low-dose astaxanthin group, burn+ medium-dose astaxanthin group, and burn+ high-dose astaxanthin group were significantly increased at PIH 48 (P<0.01), and the protein expression of HO-1 in renal tissue of rats in burn+ medium-dose astaxanthin group and burn+ high-dose astaxanthin group was significantly increased compared with that of simple burn group (P<0.01). Conclusions: Astaxanthin can attenuate the structural damage and functional decline of renal tissue and regulate the release of injury-related inflammatory factors, thus to protect the rats from acute kidney injury after burn. The HO-1/TLR4/NF-кB signaling pathway is the main regulatory mechanism of astaxanthin to achieve anti-inflammation-based renoprotection.

[One patient with severe phenol burn complicated with acute poisoning]

On April 26, 2018, a 55-year-old male patient with severe phenol burn complicated with acute poisoning was admitted to the Second Affiliated Hospital of Zhejiang University School of Medicine. The patient quickly developed the symptoms of central nervous system including blurred consciousness and restlessness, anuria, and respiratory failure. After self-rescue before admission and a series of measures in hospital including wound decontamination to reduce phenol absorption, rapid massive infusion and hemodialysis+ hemoperfusion, continuous renal replacement therapy for speeding up phenol excretion and organ function maintenance, the poisoning symptoms were effectively alleviated, and the patient was finally rescued successfully and discharged on post injury day 29. This case suggests that early hemodialysis combined with hemoperfusion and continuous renal replacement therapy are effective methods for treating severe phenol burn complicated with acute poisoning.

[Teicoplanin-induced hypersensitivity syndrome in a diabetic foot patient with malignant ulcer]

A 58-year-old male patient with diabetic foot ulcer was admitted to the Second Affiliated Hospital of Zhejiang University School of Medicine on December 11, 2018. The patient was treated with local debridement, vacuum sealing drainage treatment, and dressing change and discharged after basic wound healing. On January 15, 2019, the patient was hospitalized again due to local infection and rupture of wound surface. He underwent a surgical debridement on the third day after second admission and was given intravenous infusion of 0.4 g teicoplanin twice daily. Histopathological examination after surgery showed keratinizing squamous-cell carcinoma. An extended squamous-cell carcinoma resection plus autologous split-thickness skin grafting and vacuum sealing drainage treatment was carried out on the 10th day after second admission. The patient's whole body turned red after surgery with rash, recurrent fever over 39 ℃, leucopenia, and thrombocytopenia. A multi-disciplinary consultation of physicians attributed these symptoms to teicoplanin-induced hypersensitivity syndrome. After withdrawal of teicoplanin and administration of hormone, the patient's temperature returned to normal, and the leucocyte count and platelet count recovered gradually. The patient was cured and discharged on the 49th day after second admission. The case presented reminds us of need to strictly follow the indications of teicoplanin prior to medication, be resolute to the administration and withdrawal, and be alert to adverse drug reactions when above-mentioned abnormalities occur, meanwhile, infection and rheumatic diseases are excluded.

[Nursing care of one patient with neuromyelitis optica spectrum disorders complicated with pressure ulcers]

On February 11, 2019, a 37-year-old female patient with neuromyelitis optica spectrum disorders was admitted to the Second Affiliated Hospital of Zhejiang University School of Medicine, and her acute osteomyelitis was caused by infection of multiple pressure ulcer wounds with Staphylococcus aureus. The patient was diagnosed and treated with multidisciplinary cooperation. The nurses focused on the strict observation of the syndrome of neuromyelitis optica spectrum disorders during hormone reduction therapy, guarded against the rebound of condition, implemented wound care in stages according to the diagnosis and treatment plan, maintained effective drainage, ensured appropriate negative pressure, and strengthened nutrition to promote wound healing. After active treatment and careful nursing care, the patient recovered and was discharged on the 39th day after admission.

[Evidence summary for postoperative hypothermia rewarming in adults with severe burns]

Objective: To retrieve, evaluate, and summarize the best evidence for postoperative hypothermia rewarming in adults with severe burns. Methods: Foreign language databases including Cochrane Library, Joanna Briggs Institute Evidence-Based Health Care Center Database, PubMed, Ovid-Medline, BMJ Best Practice, and Web of Science were retrieved with the search terms of " severe burn/major burn/severe degree burn" , " hypothermia/warming intervention/hypothermia/temperature/body temperature change" , and " postoperative /perioperative/peri-operative/post-operative" and Chinese databases including Chinese Journal Full-Text Database, Wanfang Database, and VIP Database were retrieved with the search terms of "//" , "/" , and "" to obtain all the publicly published evidence for postoperative hypothermia rewarming in adults with severe burns from the establishment of each database to April 2018, including systematic evaluations, guidelines, expert consensus, evidence summary, and original research closely related to the evidence. The literatures were screened and evaluated for their quality, the evidences were extracted from them, evaluated, classified in order to summarize the best evidences. Results: A total of 8 literatures were included, including one systematic evaluation, three guidelines, one expert consensus, and three evidence summaries. Finally, the best evidences in 8 aspects including the body temperature monitoring site, body temperature monitoring frequency, surface heating, in vivo heating, rewarming start, multi-strategy rewarming, equipment, and personnel training were summarized. Conclusions: Based in the evidence-based nursing method, this study retrieves and evaluates the literature, summarizes the evidence analysis and evaluation, and obtains the best evidences of postoperative hypothermia rewarming in adult patients with severe burns, which provides a strong reference for the clinical implementation of rewarming.

Three new isoquinoline alkaloids from the whole plants of Thalictrum tenue with cytotoxic activities

Three new isoquinoline alkaloids, including two aporphines (1 and 2) and one oxoaporphine (3), were isolated from the 90% EtOH extract of the whole plants of Thalictrum tenue Franch. The structures of the isolated compounds were established based on 1D and 2D (¹H-¹H COSY, HMQC, and HMBC) NMR spectroscopy, in addition to high resolution mass spectrometry, respectively. The isolated alkaloids were tested in vitro for cytotoxic activity against six esophageal carcinoma cell lines. Consequently, alkaloids 1-3 exhibited some cytotoxic activities against all the tested tumor cell lines with IC₅₀ values less than 20 μM. [Formula: see text].

[Practice of nosocomial infection management in burn department based on the American hospital evaluation standard of the Joint Commission International]

Objective: To explore the role of continuous quality improvement measures based on the American hospital evaluation standard of the Joint Commission International (JCI) in prevention and control of nosocomial infection in Burn Department of the Second Affiliated Hospital of Zhejiang University School of Medicine (hereinafter referred to as the author' s department). Methods: From 2013 to 2018, based on 11 JCI standards related to infection prevention and control and the current situation of the author' s department, more than 50 doctors, nurses, and nursing assistants from the author' s department participated in continuous improvement of the three-level management system of nosocomial infection in the author' s department, focusing on implementing of management of patient with multidrug resistant bacteria infection, optimizing the infection control management of instrument and cloth, and implementing target management on 5 indicators such as hand hygiene implementation rate, and carrying out inspection, quality management, and improvement on 11 items of prevention and control of nosocomial infection. The implementation rate of hand hygiene from 2013 to 2018 and the accuracy rate of hand hygiene from 2016 to 2018 of medical staff in the author' s department, and incidences of catheter-related bloodstream infection (CRBSI) of central venous, catheter-associated urinary tract infection (CAUTI), and ventilator associated pneumonia (VAP) of burn intensive care unit in the author's department from 2013 to 2018 were monitored.The following 7 indicators were monitored from 2013 to 2018, including false negative rate of nosocomial infection, incidence of hyperglycemia during intensive insulin treatment for severely burned patients, the implementation rate of CRBSI preventive measures, the specification rate of surface fixation of indwelling catheter, the implementation rate of VAP preventive measures, the accuracy rate of bed temperature during the use of suspended bed, and the implementation rate of hand hygiene of standardized training medical staff in the author' s department before and after improvement. Data were statistically analyzed with chi-square test. Results: The implementation rate of hand hygiene of medical staff in the author' s department was 88.0%-89.5% from 2013 to 2018, the correct rate of hand hygiene of medical staff in the author' s department was 95.10%-97.35%, and both reached the target values. The incidences of CRBSI in 2015, VAP in 2017, and CAUTI in 2013, 2014, and 2017 of burn intensive care unit failed to reach the respective target value and reached the respective target value after quality improvement, and the above-mentioned 3 indicators reached the respective target value in other years. From 2013 to 2018, the false negative rate of nosocomial infection and the incidence of hyperglycemia during intensive insulin treatment of severely burned patients in the author' s department after improvement were significantly lower than those before improvement (χ(2)=24.50, 4.74, P<0.05 or P<0.01), the implementation rate of CRBSI preventive measures, the specification rate of surface fixation of indwelling catheter, the implementation rate of VAP preventive measures, and the accuracy rate of bed temperature during the use of suspended bed after improvement in the author' s department were significantly higher than those before improvement (χ(2)=13.78, 6.50, 20.37, 13.92, P<0.05 or P<0.01), and the implementation rate of hand hygiene of standardized training medical staff in the author' s department after improvement was similar to that before improvement (χ(2)=1.71, P>0.05). Conclusions: The introduction of JCI standard can improve the implementation rate and accuracy rate of hand hygiene of medical staff in burn department, reduce the incidences of CRBSI, CAUTI, and VAP, and improve the effect of prevention and control of nosocomial infection in burn department.

[One case of severe subcutaneous soft tissue infection caused by nonstandard insulin injection]

On January 1st 2018, a male 44 years old diabetic patient with subcutaneous soft tissue infection in right thigh was admitted to our hospital. The patient repeatedly used the same needle to inject insulin subcutaneously in the unsterilized right thigh, and his blood glucose was badly controlled in the long term. Severe subcutaneous soft tissue infection of the right thigh occurred after his fatigue, accompanied with ketoacidosis. Then he received conservative treatment in the local hospital for one month, but the infection persisted. After being transferred to our hospital, we highly suspected the diagnosis of necrotizing fasciitis according to previous test indicators and local B-ultrasound results, but suggestion of aggressive surgery was refused. So we treated him with conservative therapies using sensitive antibiotics and supportive remedies. The patient was basically healed after treatment of 1 month and he was recovered well during the follow-up 2 months after discharged from our hospital. This case emphasizes the importance of standard injection of insulin and early diagnosis of severe subcutaneous soft tissue infection.

[Epidemiological investigation of burn patients with Klebsiella pneumoniae infection and the analysis of risk factors for sepsis in them]

Objective: To analyze the prevalence trend of Klebsiella pneumoniae (KP) infection in the Department of Burns of the Second Affiliated Hospital of Zhejiang University School of Medicine (hereinafter referred to as the author's department) from 2015 to 2017, and to screen out the independent risk factors for sepsis in burn patients with KP infection. Methods: The clinical and bacteriological data of burn patients with KP infection from January 1, 2015 to December 31, 2017 were collected from the author's department. The variation trend in infection rates of KP and carbapenems-resistant KP (CRKP) during the three years were statistically analyzed, and the data were processed with chi-square test. Clinical data were processed with binary logistic regression analysis to screen out the independent risk factors for sepsis in burn patients with KP infection. Results: (1) From 2015 to 2017, 91 patients (50 males and 41 females, aged 15-90 years) with KP infection were diagnosed in the author's department, of which 65 cases were CRKP positive, and 26 cases were carbapenems-sensitive KP positive. The KP infection rates of patients in 2015, 2016, and 2017 were 5.79% (35/605), 4.08% (23/564), and 5.54% (33/596), respectively. The CRKP infection rates of patients in 2015, 2016, and 2017 were 3.31% (20/605), 3.37% (19/564), and 4.36% (26/596), respectively. There were no statistically significant differences in KP infection rate and CRKP infection rate of patients among the three years (χ(2)=2.007, 1.175, P>0.05). (2) Total burn area and CRKP infection were independent risk factors for sepsis in burn patients with KP infection (odds ratios=1.03, 5.88, 95% confidence intervals=1.01-1.05, 1.08-31.94, P<0.05). Conclusions: From 2015 to 2017, the infection rates of KP and CRKP in the author's department did not increase obviously, but the proportion of CRKP infection was high. CRKP infection is one of the independent risk factors for sepsis in burn patients with KP infection. Strengthening the prevention and treatment of CRKP infection may have certain value in decreasing the incidence of burn sepsis.

[Summary of advances in the research of wound therapy]

Wound healing is a complex and sequential biological process involving various cells and factors under body's regulation. Appropriate interventions play positive roles in promoting effective wound healing and improving healing quality. In the clinical practice, there are many new instruments, dressings, and drugs developed for wound care, including antibacterial dressings, wet dressings, precise debridement, negative pressure wound therapy, cytokines/growth factors, and dermal substitutes, which provide revolutionary means for wound treatment. This article summarizes the effective or mature methods in wound care, providing theoretical and practical basis for choosing appropriate treatment methods in different stages of wound.

[Multicenter epidemiological investigation of hospitalized elderly, young and middle-aged patients with severe burn]

Objective: To compare and analyze the epidemiological characteristics of hospitalized elderly, young and middle-aged patients with severe burn in recent years, so as to provide reference for the prevention and treatment of elderly patients with severe burn. Methods: Relying on the entry system of epidemiological case data and biological sample of severe burn from multicenter in clinic, medical records of patients with severe burn, aged above 18, hospitalized in 8 burn wards from January 2012 to December 2015 were collected. Six hundred and fifteen patients who were more than 18 years old and less than or equal to 65 years old were included in young and middle-aged group (YM). Eighty-two patients aged more than 65 years old were included in elderly group (E). Data of age, gender, residence, education level, cause of injury, location of injury, season of injury, total burn area, occurrence and area of full-thickness burn injury, wound site, inhalation injury incidence and severity, post burn admission time, proportion of delayed resuscitation, proportion of escharectomy or tangential excision and skin grafting, preinjury systemic disease, system complication during hospitalization, length of hospital stay, outcome of treatment, and reason of abandoning treatment of patients were analyzed. Data were processed with chi-square test and Mann-Whitney U test. The odds ratios of preinjury systemic disease, system complication during hospitalization, and adverse outcome of patients in group YM were compared with those in group E. Results: (1) The majority of patients in the two groups were male, but the proportion of male patients in group YM was higher. There was statistically significant difference in gender distribution of patients between the two groups (χ(2)=18.727, P<0.001). The majority of patients in the two groups were from rural areas, but the proportion of rural patients in group E was higher. There was statistically significant difference in residence distribution of patients between the two groups (χ(2)=9.306, P=0.002). Patients in group YM mainly had secondary education, while patients in group E mainly had primary education. There was statistically significant difference in distribution of education level of patients between the two groups (χ(2)=146.797, P<0.001). (2) The most common causes of injury of patients in the two groups were both flame, but the proportion of patients with flame burn injury in group E was higher. There was statistically significant difference in distribution of cause of injury of patients between the two groups (χ(2)=25.063, P<0.001). The main locations of injury of patients in groups YM and E were respectively public place and private residence. There was statistically significant difference in location distribution of injury of patients between the two groups (χ(2)=46.313, P<0.001). The main seasons of injury of patients in groups YM and E were respectively summer and winter. There was statistically significant difference in season distribution of patients between the two groups (χ(2)=23.143, P<0.001). There was statistically significant difference in distribution of total burn area of patients between the two groups (χ(2)=25.799, P=0.002). The occurrences of full-thickness burn injury of patients in the two groups were similar (χ(2)=2.685, P=0.101), while there was statistically significant difference in area of full-thickness burn injury of patients between the two groups (χ(2)=26.702, P=0.002). There was no statistically significant difference in distribution of wound site of patients between the two groups (χ(2)=3.954, P=0.785). There were no statistically significant differences in incidence and severity distribution of inhalation injury of patients between the two groups (with χ(2) values respectively 0.425 and 0.672, P values above 0.05). (3) There was statistically significant difference in distribution of admission time of patients between the two groups (χ(2)=6.632, P=0.036), but there was no statistically significant difference in proportion of delayed resuscitation of patients between the two groups (χ(2)=1.261, P=0.261). The proportion of escharectomy or tangential excision and skin grafting of patients in group YM was 72.0% (443/615), which was significantly higher than 35.4% (29/82) of group E (χ(2)=44.498, P<0.001). The incidence of preinjury systemic disease of patients in group YM was 13.2% (81/615), which was significantly lower than 61.0% (50/82) of group E (χ(2)=108.337, P<0.001). The risk of preinjury systemic disease of patients in group E was 10.30 times of that of patients in group YM [with 95% confidence interval (CI) of 6.24-17.01, P<0.001]. During hospitalization, 59.8% (49/82) of patients in group E suffered from system complications, which was significantly higher than 36.6% (225/615) of group YM (χ(2)=16.282, P<0.001). The risk of system complication of patients in group E was 2.57 times of patients in group YM (with 95% CI of 1.61-4.12, P<0.001). The length of hospital stay of patients in group E was significantly shorter than that of group YM (U=36 735, P<0.001). There was statistically significant difference in treatment outcome of patients between the two groups (χ(2)=106.251, P<0.001). The risk of adverse outcome of patients in group E was 7.52 times of group YM (with 95% CI of 4.40-12.88, χ(2)=67.709, P<0.001). The proportion of abandoning treatment of patients in group E was significantly higher than that of group YM (χ(2)=150.670, P<0.001). The risk of abandoning treatment of patients in group E was 15.86 times of that of group YM (with 95% CI of 9.36-26.88, P<0.001). There was no statistically significant difference in distribution of reason of abandoning treatment of patients between the two groups (χ(2)=4.178, P=0.243). Conclusions: There were significant differences in the epidemiological characteristics of patients in groups E and YM. In elderly burn patients, the proportion of rural population was higher and the education level was lower. Flame burn was common and burns mostly occurred in private residences and in winter. The total burn area was slightly lower but the area of full-thickness burn injury was larger. The length of hospital stay was shorter and the proportion of surgical treatment was lower. The incidences of preinjury systemic disease and system complication during hospitalization were higher, and therefore the risks of adverse outcome and abandoning treatment were higher.

[Influences of hydrogen-rich saline on acute kidney injury in severely burned rats and mechanism]

Objective: To explore the influences of hydrogen-rich saline on acute kidney injury in severely burned rats and to analyze the related mechanism. Methods: Fifty-six Sprague Dawley rats were divided into sham injury group (n=8), burn group (n=24), and hydrogen-rich saline group (n=24) according to the random number table. Rats in sham injury group were treated by 20 ℃ water bath on the back for 15 s to simulate injury, and rats in burn group and hydrogen-rich saline group were inflicted with 30% total body surface area (TBSA) full-thickness scald (hereinafter referred to as burns) by 100 ℃ water bath on the back for 15 s. Immediately after injury, hydrogen-rich saline at the dose of 10 mL/kg were intraperitoneally injected to the rats in hydrogen-rich saline group at one time, while normal saline with the same dose were intraperitoneally injected to the rats in sham injury group and burn group. At post injury hour (PIH) 6, rats in the 3 groups were intraperitoneally injected with 4 mL·kg(-1)·%TBSA(-1) lactated Ringer's solution for resuscitation. Eight rats from sham injury group at PIH 72 and eight rats from burn group and hydrogen-rich saline group at PIH 6, 24, and 72 were sacrificed respectively after their blood samples from abdominal aorta were collected. Then their kidney tissue was harvested for histopathological observation and renal tubular injury scoring by hematoxylin and eosin staining, serum creatinine and blood urea nitrogen were detected by the clinical blood biochemical analyzer, expression distribution and mRNA expressions of tumor necrosis factor α (TNF-α), interleukin-1β (IL-1β), and IL-6 in renal tissue were evaluated by immunohistochemical staining and real time fluorescent quantitive reverse transcription polymerase chain reaction respectively, and protein expression of high mobility group protein 1 (HMGB1) was detected by Western blotting. Data were processed with Kruskal-Wallis H test, Dunn test, one-way analysis of variance, Bonferroni test. Results: (1) The renal tubular structure of rats in sham injury group at PIH 72 was complete with no inflammatory cell infiltration and no cellular degeneration or necrosis. Since PIH 6, the changes such as vacuolation and shape change of cells and aggregation of broken protein in renal tubules were observed in rats of burn group, and all these changes deteriorated with time. The renal injury of rats in hydrogen-rich saline group at different post injury time points were relieved compared with those of rats in burn group at the corresponding time points. The renal tubular injury scores of rats in burn group and hydrogen-rich saline group at PIH 6, 24, and 72 were significantly higher than the score in sham injury group at PIH 72 (P<0.05). The renal tubular injury scores of rats in hydrogen-rich saline group were significantly lower than those in burn group at PIH 6, 24, and 72 (P<0.05). (2) Except for those in hydrogen-rich saline group at PIH 6 and 72 (P>0.05), the levels of serum creatinine of rats in burn group at all the time points and hydrogen-rich saline group at the other time points were significantly higher than the level of serum creatinine of rats in sham injury group at PIH 72 (P<0.01). The levels of blood urea nitrogen of rats in burn group and hydrogen-rich saline group at PIH 6, 24, and 72 were significantly higher than the level of blood urea nitrogen of rats in sham injury group at PIH 72 (P<0.01). The levels of serum creatinine and blood urea nitrogen of rats in hydrogen-rich saline group at PIH 6, 24, and 72 were significantly lower than those in burn group at the corresponding time points (P<0.05). (3) There were certain degree of positive expressions of TNF-α, IL-1β, and IL-6 in renal tissue of rats in sham injury group at PIH 72, which were mainly observed in the cytoplasm of renal tubular epithelium cell. The expressions of above-mentioned inflammatory cytokines in renal tissue of rats in burn group at PIH 6, 24, and 72 were higher than those in sham injury group. The expressions of above-mentioned inflammatory cytokines in renal tissue of rats in hydrogen-rich saline group at all the time points were less than those in burn group at the corresponding time points. (4) Compared with those in sham injury group at PIH 72, the mRNA expression levels of TNF-α, IL-1β, and IL-6 of rats in burn group at PIH 6, 24, and 72 were significantly increased (P<0.01). The mRNA expression levels of TNF-α were significantly increased in hydrogen-rich saline group at PIH 6 and 24 (P<0.05 or P<0.01), and the mRNA expression level of IL-6 was significantly increased in hydrogen-rich saline group at PIH 6 (P<0.01). Compared with those at the corresponding time points in burn group, except for the mRNA expression level of TNF-α in hydrogen-rich saline group at PIH 6 showed no significant differences (P>0.05), and the mRNA expression levels of TNF-α, IL-1β, and IL-6 at the other time points in hydrogen-rich saline group were significantly decreased (P<0.05). (5) Compared with 0.39±0.03 in sham injury group at PIH 72, the protein expression of HMGB1 of rats in burn group at PIH 6, 24, and 72 (1.19±0.07, 1.00±0.06, 0.80±0.05) were significantly increased (P<0.05), while the protein expression of HMGB1 of rats in hydrogen-rich saline group at PIH 6, 24, and 72 (0.35±0.08, 0.47±0.06, 0.42±0.06) showed no significant differences (P>0.05). Compared with those in burn group, the protein expressions of HMGB1 of rats in hydrogen-rich saline group at PIH 6, 24, and 72 were significantly decreased (P<0.05). Conclusions: Hydrogen-rich saline can alleviate the acute kidney injury in severely burned rats through regulating the release of inflammatory cytokines in renal tissue.

[Development and progress of sixty years and stepping firmly to the future]

Since its establishment for 60 years, Department of Burns of the Second Affiliated Hospital of Zhejiang University School of Medicine has grown into a famous regional burn center in China under the leading of the pioneers and through the efforts of several generations. The department has distinctive disciplinary features in burn care, nutritional support, scar prevention and treatments, standard management of chronic wound, and skin tissue engineering research, making positive contribution to the development of burn medicine in China.

[Analysis on clinical characteristics of 316 patients with hydrofluoric acid burns]

Objective: To investigate the clinical characteristics of patients with hydrofluoric acid (HF) burns. Methods: Clinical data of 316 patients with HF burns admitted to Zhejiang Quhua Hospital from January 2004 to December 2016 were retrospectively analyzed. Patients were divided into non and mild poisoning group (NMP, n=157), moderate poisoning group (MP, n=120), and severe and fatal poisoning group (SFP, n=39) based on the severity of poisoning. Occurrences of hypocalcemia, hypomagnesemia, hypokalemia, and hyperkalemia of patients within 24 hours after admission were recorded. Values of emergency urinary fluoride of patients on admission were recorded. Values of urinary fluoride of patients admitted to hospital in 4 hours post injury in groups MP and SFP at post injury hour 4, 12, and 24 and on post injury day 2, 3, 4, 5, 6, and 7 were also recorded. Electrocardiographic abnormalities of patients within 24 hours after admission were recorded. Data were processed with chi-square test, Kruskal-Wallis H test, and Mann-Whitney U test. Results: (1) Hypocalcemia, hypomagnesemia, and hypokalemia occurred in some patients in each of the three groups, but no patient had hyperkalemia. Taking serum calcium namely total serum calcium as reference, the incidence rate of hypocalcemia of patients in group NMP was close to that in group MP (χ(2)=0.05, P>0.05). The incidence rate of hypocalcemia of patients in group SFP was significantly higher than that in group NMP or group MP (χ(2)=10.53, 7.92, P<0.01). The incidence rates of hypokalemia in the three groups were close (χ(2)=0.63, P>0.05). Taking serum ionized calcium as reference, the incidence ratio of hypocalcemia of patients in group NMP was close to that in group MP (χ(2)=0.01, P>0.05), while there were statistically significant differences in incidence ratio of hypocalcemia of patients between group SFP and each of group NMP and group MP (χ(2)=4.66, 4.47, P<0.05). Taking serum calcium as reference, the incidence rate of hypocalcemia of patients was 7.3% (23/316). Taking serum ionized calcium as reference, the incidence rate of hypocalcemia of patients was 60.0% (42/70), which was significantly higher than that of taking serum calcium as reference (χ(2)=113.74, P<0.01). The incidence rates of hypomagnesemia of patients in groups MP and NMP were close (χ(2)=0.02, P>0.05). The incidence rate of hypomagnesemia of patients in group SFP was significantly higher than that in group NMP or group MP (χ(2)=14.69, 9.94, P<0.01). (2) The urinary fluoride levels were tested in 288 patients, with the value of emergency urinary fluoride of patients on admission 0.2-590.0 mg/L. The values of urinary fluoride of 202 patients were above the normal value. The values of emergency urinary fluoride of patients in groups NMP, MP, and SFP were 2.15 (1.11, 4.30), 5.89 (1.72, 14.25), and 36.0 (13.2, 103.2) mg/L, respectively. The values of emergency urinary fluoride of patients in groups MP and SFP were significantly higher than the value in group NMP (χ(2)=23.28, 66.03, P<0.01). The value of emergency urinary fluoride of patients in group SFP was significantly higher than that in group MP (χ(2)=39.23, P<0.01). The value of urinary fluoride of 33 patients admitted to hospital within 4 hours post injury in groups MP and SFP reached the top at 4 hours post injury and then gradually declined, which returned to normal on about 5 days post injury. The values of urinary fluoride of patients in group SFP at 4, 12, and 24 hours post injury and on 2, 3, 4, 5, 6, and 7 days post injury were significantly higher than those in group MP (Z=-4.28, -4.15, -3.81, -4.21, -2.48, -2.06, -2.31, -2.68, -3.03, P<0.05 or P<0.01). (3) Twenty-seven patients had electrocardiographic abnormality. There were 12 patients with T wave changes (the most common), 8 patients with ST-T changes, 6 patients with ventricular arrhythmias, 6 patients with conduction block, and 1 patient with broadened QRS waveform. There was no patient with prolonged Q-T interval. The ratios of patients with the above electrocardiographic abnormalities in group SFP were higher than those in group NMP and group MP. Conclusions: Clinical manifestations of patients with HF burn are hypocalcemia, hypomagnesemia, hypokalemia, and electrocardiographic abnormality. In addition to routine serum electrolyte and electrocardiogram monitoring, the levels of serum ionized calcium and urinary fluoride can be helpful to evaluate the severity of illness of the patients.

[Analysis on effects of modified dosage of calcium gluconate on patients with hydrofluoric acid burns not in hands or feet]

Objective: To retrospectively explore the effects of modified dosage of calcium gluconate (CG) on the patients with hydrofluoric acid burns not in hands or feet. Methods: One hundred and sixty patients with hydrofluoric acid burns not in hands or feet were hospitalized in our burn ward from January 2004 to December 2017. Based on the dosage of CG at different admission time, 76 patients hospitalized from January 2004 to December 2012 were included in traditional group, and 84 patients hospitalized from January 2013 to December 2017 were included in modified group. For patients in the two groups, subcutaneous injection of CG solution at one time was immediately conducted on admission in topical treatment. In traditional group, the injection was CG solution with mass concentration of 100 g/L. For wounds of superficial partial-thickness and above degree, CG solution was prescribed at the dosage of 50 mg/cm(2). Wounds of superficial-thickness or mass fraction of hydrofluoric acid less than 20.0% did not receive injection. In modified group, the mass concentration of CG solution for injection was diluted with normal saline to 25 g/L. For wounds of deep partial-thickness and above degree, CG solution was prescribed at the dosage of (50×mass fraction of hydrofluoric acid) mg/cm(2). For wounds of superficial partial-thickness, CG solution was prescribed at the dosage of (25×mass fraction of hydrofluoric acid) mg/cm(2). For wounds of superficial-thickness, CG solution was prescribed at the dosage of 2.5 mg/cm(2). For systemic treatment, the injection velocity of CG solution via venous access was adjusted according to the level of serum calcium namely total serum calcium of patients in traditional group. In modified group, serum ionized calcium was additionally detected through automatic blood gas analyzer by the bed to regulate the injection velocity of CG via venous access. The incidence rate of hypercalcemia and mortality of patients after treatment in the two groups, and the situation about treatment of survivors in the two groups were analyzed. Data were processed with chi-square test, Fisher's exact probability test, t test, and Mann-Whitney U test. Results: (1) After treatment, 9 patients (11.8%) had hypercalcemia, while the other 67 patients (88.2%) did not have hypercalcemia in traditional group. Two patients (2.4%) had hypercalcemia, while the other 82 patients (97.6%) did not have hypercalcemia in modified group. The incidence rate of hypercalcemia of patients in traditional group was significantly higher than that in modified group (χ(2)=5.579, P=0.02). (2) There were two deaths (2.6%) and 74 survivors (97.4%) in traditional group, while there were two deaths (2.4%) and 82 survivors (97.6%) in modified group. The mortalities of patients in the two groups were close (P>0.05). (3) The ratios of eschar excision and skin grafting and hyperplastic scar formation, wound healing time, and ratio of esophageal scar stenosis of survivors in the two groups were close (χ(2)=0.002, 0.054, Z=0.66, P>0.05). Conclusions: Hydrofluoric acid is highly dangerous. The early management of patients with hydrofluoric acid burns emphasizing specialized dosage of CG for treatment can be helpful to reduce incidence of complications and improve the safety of treatment.

[Advances in the research of application of three-dimensional bioprinting in skin tissue engineering]

Deep skin wounds require skin grafts for coverage. Current treatments such as tissue engineered skin or skin substitutes can not meet the needs of clinical application due to the technical problems involving preservation, transportation, and a lengthy preparation process. In comparison with traditional methods such as freeze-drying, three-dimensional bioprinting can precisely dispense living cells, nucleic acid, growth factor, and phase-changing hydrogels according to the wound form, while maintaining high cell viability. Besides, it has excellent performance in high resolution, flexibility, reproducibility, and high throughput, showing great potential in the fabrication of tissue engineered skin. This review mainly introduces the common techniques of three-dimensional bioprinting, and their application in skin tissue engineering, focusing on the latest research progress, and summarizes the current challenges and future development of three-dimensional skin printing.

[Effects of endostatin pretreatment on fibrosis of human skin fibroblasts and the mechanisms]

Objective: To explore the effects of endostatin pretreatment on fibrosis of human skin fibroblasts and the mechanisms. Methods: Human skin fibroblasts were routinely cultured in vitro, and then the cells of passage 3 to 5 were used in the following experiments. The cells were divided into blank control, endostatin, platelet-derived growth factor-BB (PDGF-BB), endostatin+ PDGF-BB, transforming growth factor-β(1) (TGF-β(1)), and endostatin+ TGF-β(1) groups according to the random number table, with 3 wells in each group. Cells in blank control group were cultured with DMEM medium for 24 h. Cells in endostatin group were cultured with DMEM medium containing 5 μg/mL endostatin for 24 h. Cells in PDGF-BB group and TGF-β(1) group were cultured with DMEM medium containing 200 ng/mL PDGF-BB and 10 ng/mL TGF-β(1) for 24 h, respectively. Cells in endostatin+ PDGF-BB group were pretreated with DMEM medium containing 5 μg/mL endostatin for 48 h and then cultured with DMEM medium containing 200 ng/mL PDGF-BB for 24 h. Cells in endostatin+ TGF-β(1) group were pretreated with DMEM medium containing 5 μg/mL endostatin for 48 h and then cultured with DMEM medium containing 10 ng/mL TGF-β(1) for 24 h. The content of type Ⅰ collagen in the cell culture supernatant of three wells in each group was determined by enzyme-linked immunosorbent assay. The protein expression levels of α-smooth muscle actin (α-SMA), PDGF receptor β (PDGFRβ), phosphorylated PDGFRβ (p-PDGFRβ), and phosphorylated extracellular signal-regulated protein kinases 1/2 (p-ERK1/2) of three wells in each group were detected by Western blotting. Data were processed with one-way analysis of variance and SNK test. Results: (1) Compared with (5.05±0.29) pg/mL in blank control group, content of type Ⅰ collagen in the cell culture supernatant of endostatin group [(4.72±0.37) pg/mL] was close to it (P>0.05), content of type Ⅰ collagen in the cell culture supernatant of PDGF-BB group and TGF-β(1) group [(8.60±0.57) and (9.20±0.64) pg/mL, respectively] was higher (with P values below 0.05). Content of type Ⅰ collagen in the cell culture supernatant of endostatin+ PDGF-BB group [(5.32±0.17) pg/mL] was lower than that of PDGF-BB group (P<0.05), and content of type Ⅰ collagen in the cell culture supernatant of endostatin+ TGF-β(1) group [(5.41±0.20) pg/mL] was lower than that of TGF-β(1) group (P<0.05). (2) Compared with those in blank control group, protein expression levels of α-SMA, PDGFRβ, p-PDGFRβ, and p-ERK1/2 of cells in endostatin group showed no obvious differences (with P values above 0.05), while those in PDGF-BB and TGF-β(1) group were significantly higher (with P values below 0.01). Protein expression levels of α-SMA, PDGFRβ, p-PDGFRβ, and p-ERK1/2 of cells in endostatin+ PDGF-BB group and endostatin+ TGF-β(1) group were significantly lower than those in PDGF-BB group and TGF-β(1) group, respectively (with P values below 0.05). Conclusions: Pretreatment of endostatin can inhibit the fibrosis of human skin fibroblast and its transformation into myofibroblast, which may be related to the down-regulation of protein expression of p-PDGFRβ, PDGFRβ, and p-ERK.

[Analysis on on-site rescue and traumatic features of victims involved in gas explosion accident in Hangzhou]

Objective: To investigate the situations of on-site rescue and traumatic features of victims involved in gas explosion accident in Hangzhou, so as to provide more data support for emergency medical rescues of the similar incidents of massive casualty. Methods: Two medical workers with a certain clinical experience were sent to Hangzhou 120 emergency medical centers to collect data of the on-site rescue on 21st July, 2017, including ambulance call-outs, on-site command and traffic conditions, and on-site triage and evacuation of the victims. They were then sent to the hospitals receiving the victims to investigate the situations of these victims including the general information (such as gender, age, admitted hospitals, and number of admission, discharge, and transferring in the first two weeks after the accident) and injury assessment [such as injury position and type, injury severity evaluation by New Injury Severity Scoring (NISS), and burn severity evaluation for victims with burns]. Results: (1) A total of 15 ambulances reached the accident site for rescue. The traffic and transportation were jammed and interrupted after this accident. On-site triage and distribution were disorderly conducted. (2) Clinical data of 53 victims were collected, including 24 males and 29 females, with the age of 8 to 70 (34±14) years old. They were sent into 6 hospitals in Hangzhou. Two victims died on the day of accident. Up to two weeks after this accident, 28 (52.8%) victims were discharged from the hospitals and received follow-up in outpatient department. Five victims with severe injuries were transferred to the other hospitals. (3) Based on the results of NISS, the injury severities were mild in 29 (54.7%) cases, moderate in 9 (17.0%) cases, serious in 3 (5.7%) cases, and severe in 12 (22.6%) cases. Those 2 dead victims were classified into the severe category due to the highest NISS score of 75. For all of the victims, skin and soft tissue defects were most common. Six (11.3%) victims were combined with burns. According to the classification of burn severity, there were one case of mild, one case of serious, and 4 cases of severe. Conclusions: The gas explosion accident in Hangzhou caused massive casualties with complex injuries. The local emergency medical rescue responded quickly, but during the rescue process, lots of aspects should be further improved.

[Wound healing is still a game of " blind men and an elephant"]

The wound healing includes non-healing and overhealing of the wounds. The results of wound healing are well known by people such as non-healing of the diabetic ulcer or hypertrophic scar after deep burn. In this issue, three papers involve in wound healing, one about autologous adipose-derived mesenchymal stem cells injected into wound or scar of rabbit ear, one about severe hypoxia and hypoalbuminemia inducing human hypertrophic scar derived fibroblast apoptosis in vitro, and another about the dysfunction of protein kinase B/mammalian target of rapamycin signaling pathway contributing to the pathophysiological characteristics of diabetic skin and non-healing wound. The basic problem of hypertrophic scar study is lacking an ideal animal model. Although rabbit ear model or red Duroc pig model has been used widely for study on hypertrophic scar, they can not fully represent human dermal fibrosis after deep trauma on the skin. I recommend A novel nude mouse model of hypertrophic scarring using scratched full thickness human skin grafts recently published in Advances in Wound Care to the readers. The author emphasizes that the wound healing study is still in the situation like the game of " blind men and an elephant" .

[Advances in the research of negative-pressure wound therapy inducing the vascularization of dermal substitute]

In clinical practice, skin defects resulted from various acute and chronic diseases occur frequently. Dermal substitute (DS), known as dermal regenerative template, is used more and more widely, but the slow process of vascularization limits its clinical application. At present, there are many strategies developed to enhance the process of vascularization, such as modifying the structure of dermal scaffolds, prevascularization by seeding stem cells and/or endothelial cells. Recently, negative-pressure wound therapy (NPWT) emerged and rapidly became popular in promoting wound healing due to its intrinsic advantages. Furthermore, some researchers introduced this technique to accelerate the vascularization process of DS. This paper represents a comprehensive overview on the efficiency of NPWT in different combination models, and the related mechanism.

[Brief disserting on the balance of internal environment in burn disease]

The essential internal environment in human being involves water, electrolyte, and acid-base balance, which is the basis of balance and stability of internal environment in other systems. For burn patients, the balance of internal environment, referring to metabolism, nutrition, inflammatory response, and immunoreaction, is one of the most important aspects in burn disease. This paper aims to briefly elaborate the balance of internal environment after burn, with the purpose to promote the basic and clinical research in this field.

[Effect of inhibiting perivascular adhesion on intimal hyperplasia of the vein grafts in rabbits]

Objective: To investigate the effect of preventing perivascular adhesion with topical application of sodium hyaluronate on intimal hyperplasia of the vein grafts in rabbits. Methods: Twenty-four male New Zealand white rabbits, aged 5 months, were randomly divided into 2 groups: Group A and B (n=12 rabbits per group). Artery defect model was established by cutting about 1 cm artery from the middle part of the dissociated left common carotid artery. A section about 3 cm was cut from the right external jugular vein, and the harvested vein was inverted and end-to-end anastomosed to the artery defect. After anastomosis, the adventitia and two anastomosis of the grafted veins in group A was applied 0.2 ml sodium hyaluronate locally to, and corresponding site in Group B was served as a control, but with the sterile normal saline. The grafted veins were obtained 1, 2 and 4 weeks after operation, HE staining and Masson staining were preformed for histological changes of grafted vein wall, proliferating cell nuclear antigen (PCNA) and platelet-derived growth factor (PDGF) immunohistochemistry staining were conducted for proliferation and expression and distribution of PDGF of the grafted vein. Results: The macroscopic and histological observation showed that the perivascular adhesions in Group A were looser when compared with those in Group B. The thickness of the intima, the degree of intima hyperplasia of 2 groups at different time points were as follows: at 1 week after operation, group A[(25.5±3.9) μm, (1.2±0.1) ]and group B[(26.2±4.2)μm, (1.2±0.1)]; at 2 weeks after operation, group A[(44.3±2.5)μm, (1.2±0.1)]and group B[(51.0±3.8)μm, (1.4±0.0)]; at 4 weeks after operation, group A[(69.9±6.8)μm, (1.5±0.1)] and group B[(84.4±6.4)μm, (1.7±0.1)]. Group A was inferior to group B in terms of the above three parameters 2 and 4weeks after operation (P<0.05). Cell proliferation index of intima and that of media were as follows: at 1 week after operation, group A (7.4±2.2), (21.5±3.2) and group B (11.5±2.0), (28.6±4.5); at 2 weeks, group A (20.0±3.2), (35.8±3.4) and group B (26.8±4.1), ( 42.6±4.2); at 4 weeks, group A (11.4±2.0), (22.1±2.7) and group B (15.5±2.4, 28.6±3.9). Group A was inferior to group B in terms of cell proliferation index of intima and media 1, 2 and 4 weeks after operation (P<0.05). The percentage of PDGF-positive cells of intima, media and adventitia was as follows: at 1 week after operation, group A (7.7±1.6), (19.6±3.7), (2.5±1.5) and group B (7.6±2.4), (20.6±4.4), (10.3±2.3); at 2 weeks after operation, group A (11.4±2.6), (19.8±3.1), (12.9±3.3) and group B (19.5±3.5), ( 30.6±5.2), (30.5±5.8); at 4 weeks after operation, group A (6.2±1.9), ( 11.1±2.8), (10.2±2.4) and group B (10.5±2.0), (18.6±3.2), (26.5±3.8). Group A was inferior to group B in terms of the percentage of PDGF-positive cells of intima, media and adventitia 2 and 4 weeks after operation (P<0.05) and Group A was inferior to group B that of adventitia 1 week after operation (P<0.05). Conclusion: Preventing perivascular adhesion with topical application of sodium hyaluronate can inhibit intimal hyperplasia.

[Influence of collagen/fibroin scaffolds containing silver nanoparticles on dermal regeneration of full-thickness skin defect wound in rat]

Objective: To explore the influence of collagen/fibroin scaffolds containing silver nanoparticles on dermal regeneration of full-thickness skin defect wound in rat. Methods: Eighty-one collagen/fibroin scaffolds containing silver nanoparticles (with the mass concentration of silver nanoparticles as 10 mg/L) and 81 collagen/fibroin scaffolds without silver nanoparticles were produced respectively with freeze-drying method and enrolled as silver nanoparticles scaffold group (SNS) and control scaffold group (CS). Nine scaffolds in each group were cultured with human fibroblasts. At post culture hour (PCH) 2, 12, and 24, the human fibroblasts adherent to the scaffolds (n=3) in two groups were counted. Four full-thickness skin defect wounds were reproduced on the back of each one of the 36 SD rats. The rats were divided into groups SNS (wounds were transplanted with collagen/fibroin scaffolds containing silver nanoparticles) and CS (wounds were transplanted with collagen/fibroin scaffolds without silver nanoparticles) according to the random number table, with 18 rats in each group. In post surgery week (PSW) 1, 2, and 4, 6 rats in each group were sacrificed respectively for general observation, observation of histological structure, inflammatory cell infiltration, and collagen deposition with HE staining, count of CD68 positive cells with immunohistochemical staining, and mRNA expressions of interleukin-6 (IL-6) and IL-10 with real-time fluorescent quantitative reverse transcription polymerase chain reaction. Data were processed with analysis of variance of factorial design, t test, and Bonferroni correction. Results: (1) At PCH 2, 12, and 24, the numbers of human fibroblasts adherent to the scaffolds in the two groups were close (with t values from 1.77 to 2.60, P values above 0.05). (2) In PSW 1, no obvious symptom of infection was observed in wound or wound edge of rats in group SNS with obvious vascularization of scaffolds, while obvious symptoms of infection were observed in wounds of rats in group CS with some scaffolds exfoliated. In PSW 2, the scaffolds were firmly attached to the wounds of rats in group SNS, while obvious contracture was observed in the wounds of rats in group CS with a lot of scaffolds exfoliated. In PSW 4, the scaffolds covered the wounds of rats in group SNS with obvious epithelization on the surface of the scaffolds, while all the scaffolds exfoliated, leaving obvious contracture of residual wounds of rats in group CS. (3) In PSW 1 and 2, compared with those in group CS, more collagen secretion and tissue regeneration and less inflammatory cell infiltration in the scaffolds were observed in the wounds of rats in group SNS. In PSW 4, obvious epithelization was observed in the wounds of rats in group SNS, while inflammatory cell infiltration was observed without obvious epithelization in the wounds of rats in group CS. (4) In PSW 1, the number of CD68 positive cells in the wounds of rats in group SNS [(54±10) /mm(2)] was similar to that in group CS [(78±7) /mm(2,) t=1.52, P>0.05]. In PSW 2 and 4, the numbers of CD68 positive cells in the wounds of rats in group SNS [(154±10) and (77±7) /mm(2)] were significantly less than those in group CS [(268±16) and (136±13) /mm(2,) with t values respectively 7.31 and 3.83, P values below 0.01] respectively. (5) Except for the expression in PSW 4 (t=1.23, P>0.05), the mRNA expressions of IL-6 in the wounds of rats in group SNS in PSW 1 and 2 were significantly lower than those in group CS (with t values respectively 13.12 and 4.65, P values below 0.01). Except for the expression in PSW 1 (t=3.08, P<0.05), the mRNA expressions of IL-10 in PSW 2 and 4 in the wounds of rats in the two groups were similar (with t values respectively 2.14 and 0.49, P values above 0.05). Conclusions: Besides good biocompatibility, collagen/fibroin scaffolds containing silver nanoparticles have obvious effect in modulating inflammation, thus they can accelerate dermal regeneration induced by collagen/fibroin scaffolds for wound repair.

[Investigation on events of bus on fire in 6 years in the mainland of China]

Objective: To retrospectively analyze the characteristics of events of bus on fire in 6 years in the mainland of China. Methods: Events of bus on fire happened between January 2009 and December 2014 were retrieved through Baidu search engine, Chinese Journals Full-text Database, and PubMed database in the search strategy with " bus" and " fire" or " arson" as keywords combined with the name of provinces, autonomous regions, and municipalities of the mainland of China. The occurrence time, region, cause of fire, casualties of each event were recorded, and the correlative analysis was conducted. Data were processed with Microsoft Excel software. Results: Totally 287 events of bus on fire were retrieved, among which 49 events happened in 2009, 36 events happened in 2010, 35 events happened in 2011, 37 events happened in 2012, and respectively 65 events happened in 2013 and 2014. The events of bus on fire most frequently happened in June and July, respectively 49 and 39 events. Among the distribution of occurrence regions of events of bus on fire, there were 78 events (27.18%) in east China, 52 events (18.12%) in northeast China, 41 events (14.29%) both in north China and south China. Among the causes of events of bus on fire, spontaneous combustion of bus ranked in the first (267 events, accounting for 93.03%), followed by arson (13 events, accounting for 4.53%). Among the 13 events of bus on fire caused by arson, 7 events happened between 16: 00 and 20: 00, and 3 events happened between 8: 00 and 10: 00. Totally 27 events of bus on fire (9.41%) were with casualties, among which 13 events (48.15%) were caused by spontaneous combustion of bus, 10 events (37.04%) were caused by arson, and 4 events (14.81%) were caused by traffic accidents. Arson caused the most severe casualties (at least 88 deaths and 287 injuries), followed by spontaneous combustion of bus (at least 35 deaths and 140 injuries) and traffic accidents (at least 9 deaths and 20 injuries). Conclusions: Events of bus on fire happened more frequently in recent years in the mainland of China, and the frequencies were much higher especially in June and July. Most events were caused by spontaneous combustion of bus, followed by arson. Most of the events of bus on fire caused by arson happened in the morning and evening rush hours of urban traffic, and althouth the occurrence rate was not high, the casualties were most severe.

[Advances in the research of acute kidney injury post burn]

Acute kidney injury (AKI), one of the common and important complications post burn, shows a high incidence and mortality in severely burned patients. The common etiologic factors involved in the development of AKI post burn include hypovolaemia, denatured proteins, nephrotoxic agents, etc., while the molecular mechanisms include oxidative stress injury, systematic or local inflammation, apoptosis, and so on. Furthermore, quite a few signaling pathways participate in the regulation of the occurrence and development of AKI post burn. Existed researches on the treatment of AKI post burn focus on the fluid replacement, renal replacement therapy, anti-infection, and specific agents interfering pathophysiologic or molecular mechanisms of AKI. In this review, we summarize the new advances in the research of the occurrence, development, and diagnosis and treatment of AKI post burn.

Evaluation of the semen swim-up method for bovine sperm RNA extraction

Isolation of high-quality RNA is important for assessing sperm gene expression, and semen purification methods may affect the integrity of the isolated RNA. This study evaluated the effectiveness of the sperm swim-up method for seminal RNA isolation. Frozen semen samples in straws from three bulls of proven fertility were purified by the swim-up method. RNA extraction was carried out using the E.Z.N.A.(TM) Total RNA kit II, with non-swim-up sperm as a control. Total sperm RNA was analyzed by UV spectrophotometry, reverse transcription polymerase chain reaction (RT-PCR), and agarose gel electrophoresis, and expression of the sex-determining region on the Y chromosome (SRY), leptin (LEP), and ribosomal protein subunit 23 (RPS23) genes, were determined. 18S RNA was used as a positive control. Fewer somatic cells were found in sperm swim-up samples than in the non-swim-up counterparts (0 x 10(3) vs 17.33 ± 2.52 x 10(3) sperm, P < 0.05). In addition, high-quality RNA was obtained in about 2 h, with no significant difference between groups. Interestingly, the yields of RNA fragments containing ≥200 nucleotides were significantly reduced in sperm swim-up samples (0.92 ± 0.41 x 10(7) sperm) compared with the non-swim-up samples (1.36 ± 0.33 x 10(7) sperm, P < 0.05). After RT-PCR, clear bands representing SRY, LEP, and RPS23 in sperm cDNA were observed on agarose gel electrophoresis. Finally, no bands corresponding to 18S RNA were found in RNA samples from the sperm swim-up group. Our findings suggest that small amounts of sperm RNA can be efficiently extracted from frozen straw semen samples using the swim-up technique.

Expression patterns and association analysis of the porcine DHX58 gene

RIG-1 signalling is responsible for the detection of cytoplasmic viral RNA molecules. DEXH(Asp-Glu-X-His) box polypeptide 58 (encoded by DHX58) is a negative regulator of the RIG-1 signalling pathway. In human, the DHX58 gene can be upregulated and can inhibit the RIG-1 signalling pathway during viral infection. In this study, porcine DHX58 gene expression patterns were studied. According to our results, the porcine DHX58 gene was upregulated not only by the stimulation of Poly I:C but also by the stimulation of lipopolysaccharides (LPS). One polymorphism (g.4919G>C), detected in the ninth intron,was significantly associated with some blood parameters including the red cell distribution width of 1-day-old pigs and white blood cell counts, lymphocyte absolute counts, and platelet distribution width of 17-day-old pigs (P < 0.05). Moreover, the individuals with the genotype GG have a significantly higher mean white blood cell count than individuals with genotype CC or GC (P < 0.05). Our study indicates that DHX58 is an important gene that is associated with the immune response in swine.

Results of renal ultrasonography performed before and during administration of saline (0.9% NaCl) solution to induce diuresis in dogs without evidence of renal disease

OBJECTIVE

To evaluate the effect of saline (0.9% NaCl) solution administered IV to induce diuresis on 15 dimensional variables of the kidneys, size of renal pelvis, and diameter of the cranial part of the ureters.

ANIMALS

25 dogs without evidence of renal disease that were undergoing chemotherapy for various neoplasms.

PROCEDURE

The kidneys, cranial aspect of the ureters, and trigone area of the urinary bladder of each dog were examined ultrasonographically before and during IV administration of saline solution (2.7 to 18.8 ml/kg of body weight/h).

RESULTS

Ultrasonography revealed unilateral and bilateral pyelectasis during diuresis in 16 of 23 (70%) dogs but unilateral pyelectasis in only 1 dog before diuresis. Unilateral pyelectasis during diuresis was observed in 11 of 16 (69%) dogs. Pyelectasis during diuresis was categorized as slight in 15 of 21 (71%) kidneys. Degree of pyelectasis during diuresis was not identical in both kidneys of 13 of 16 (81 %) dogs. Diuresis did not induce ureterectasis, and it did not cause changes in 15 dimensional variables of the kidneys.

CONCLUSIONS

In nonsedated, nonazotemic dogs, IV administration of saline solution to induce diuresis may cause slight pyelectasis without evidence of ureterectasis.

CLINICAL RELEVANCE

When dilatation of the cranial part of the ureter is > 2 mm at the same time that ipsilateral pyelectasis is detected during ultrasonographic examination of the urinary tract system of a nonsedated, nonazotemic dog receiving IV administration of saline solution to induce diuresis, additional examinations are recommended to determine the possibility of early obstructive nephropathy or pyelonephritis.

A prospective clinical trial comparing metrizamide and iohexol for equine myelography

A prospective clinical trial comparing adverse postmyelographic effects and myelographic quality of metrizamide and iohexol was conducted. Using a predetermined, randomized assignment, 24 horses exhibiting neurologic signs were administered either metrizamide (180 mgl/ml) or iohexol (180 mgl/ml) via cerebellomedullary puncture. Each horse was evaluated postmyelographically for adverse effects. Myelographic quality was assessed by a numerical scoring method. Adverse effects were observed more frequently with metrizamide (21) compared with iohexol (6) myelography (p < 0.05). Seizures, intensification of preexisting neurologic signs and prolonged anesthetic recovery were the most common complications after myelography. There was no difference in myelographic quality (p > 0.05). We conclude that iohexol is safer than metrizamide for equine myelography and that quality myelograms can be obtained with either contrast medium.

Phase II clinical trial of carboplatin in canine transitional cell carcinoma of the urinary bladder

Fourteen dogs with histologically-confirmed transitional cell carcinoma (TCC) of the urinary bladder were treated with 300 mg/m2 carboplatin every 3 weeks. Response to therapy was assessed with abdominal radiography, double contrast cystography, urinary bladder ultrasonography and thoracic radiography before therapy and at 6-week intervals during therapy. Dogs were monitored for hematologic toxicity with a CBC and platelet count performed immediately before and 10 to 14 days after carboplatin treatment. Tumor responses included progressive disease in 11 dogs and stable disease in 1 dog. Two dogs were euthanized due to carboplatin toxicity before assessment of tumor response. Toxicity included thrombocytopenia with or without neutropenia in 7 dogs and gastrointestinal toxicity in 6 dogs. Carboplatin therapy was not beneficial in the treatment of TCC in the 14 dogs in this study.

Early detection of anti-HCc antibody in acute hepatitis C virus (HCV) by western blot (immunoblot) using a recombinant HCV core protein fragment

Crude extract from Escherichia coli which expressed a recombinant protein containing amino acids 2 to 127 of the hepatitis C virus (HCV) core protein was used to detect the antibody against HCV core protein (anti-HCc). After electrophoretic separation of proteins from the extract, Western blot (immunoblot) analysis was performed with the serum samples. This method was compared with a commercially available second-generation enzyme immunoassay (EIA) which employed synthetic peptides corresponding to highly antigenic segments of both structural and nonstructural portions of HCV. Also, reverse transcription PCR for HCV RNA was used for comparison. Seventy-two serum samples from three groups of patients were tested. Groups I and II represented healthy subjects and subjects with acute hepatitis A or B, respectively. Group III included patients with newly acquired acute hepatitis C. By Western blot analysis, 31 of 31 (100%) samples from group I were negative for anti-HCc antibody, whereas 4 of 22 (18%) samples from group II were positive for anti-HCc. One of these four samples was also positive for anti-HCV antibody by the second-generation EIA (1 of 22 [4.5%]). Among 19 patients diagnosed with newly acquired acute hepatitis C, 4 (21%) were positive for anti-HCV by the second-generation EIA, whereas 12 of 19 (63%) were positive for anti-HCc by Western blot analysis. Of EIA-positive subjects, 4 of 4 (100%) were also positive for anti-HCc by Western blot analysis, whereas among EIA-negative subjects, 8 of 15 (53%) were positive. For HCV RNA detected by reverse transcription PCR, 15 of 19 (80%) of this group of samples were positive. Strikingly, the peak bilirubin level for patients with EIA-negative and Western blot-positive results is significantly higher than that for patients with consistent EIA and Western blot results (22.7 versus 7.2 mg/dl). A series of serum samples from a patient with concurrent hepatitis B and C viral infection was also studied by both tests. Although anti-HCc persisted throughout the course of infection, anti-HCV by EIA converted from negative to positive 20 days after admission and then converted back to negative 30 days later.

[Changes in body zinc and copper levels in severely burned patients and the effects of oral administration of ZnSO4 by a double-blind method]

The trace elements and the effect of zinc sulphate on wound healing of 46 severely burned patients in recent 2 years were studied. By double blind method 22 patients accepted capsular ZnSO4 (660 mg) per day as treated group and 24 patients medical starch as control. ZnSO4 and placebo were taken from 3rd or 5th day post burn until healing. Serum and 24h urine Zn and Cu were measured on days 3, 5, 9, 13 post burn and later weekly until healing. The changes of Zn and Cu in serum and urine in all patients were similar to the results reported by others. But the serum Zn on day 9 and urine Zn on days 5, 9, 13 post burn in treated group were significantly higher than that in control group. The basic wound healing time was same in both groups, but the patients in treated group whose coefficient UBS* (Unit of Burned Surface) was more than 180 were cured 8 days earlier than the patients of same severity in control group. At the healing the serum Zn in treated group was significantly higher than that in normal control group, while the serum Zn in control group was as same as in normal control group. The rising to normal of value of Zn/Cu in treated group was significantly earlier than that in control group. But the linear regression equations of serum Zn and Cu, urine Zn and Cu in both groups have no significant difference in the whole course of disease. No side effects of ZnSO4 have been found during the course.(ABSTRACT TRUNCATED AT 250 WORDS)

Extensive scalds following accidental immersion in hot water pools

The scalds produced by immersion in hot water pools were extensive, usually of superficial depth on the upper parts of the body and deep dermal or full thickness skin loss on the lower parts. Blisters appeared rather slowly, within 2 days post-burn and often dispersed spontaneously. The estimated burned area on admission may thus be smaller than found subsequently. This study showed that the volume of fluid required for adequate resuscitation during the first post-burn day may be only 1.5 ml/kg/% BSA burned. Deep dermal burns were treated preferably by early tangential excision and grafting. The full thickness skin loss was treated by escharectomy and skin grafts.

Chloroquine resistance trials in Papua New Guinea. 1. Maprik and Popondetta areas

The response of Plasmodium falciparum infections to a standard weight related dose of chloroquine using the W.H.O. Extended Field Test was investigated in the Maprik and Popondetta areas of Papus New Guinea. Fourteen cases of P. falciparum in Maprik and 12 cases at Popondetta were followed daily for seven days and weekly for a further three weeks after receiving 25 mg/kg of chloroquine over three days. All subjects responded well, the parasitaemias cleared in all cases by the fourth day after initiation of treatment and no recrudescences occurred in any subject in the month following therapy. No indication of chloroquine resistance was found in these two areas.